Use IP4 classes and rename conf variables

27 files changed, 466 insertions, 890 deletions

diff --git a/src/char/char.cpp b/src/char/char.cpp
index ab68322..5f63c2a 100644
--- a/src/char/char.cpp
+++ b/src/char/char.cpp
@@ -41,7 +41,7 @@ int server_freezeflag[MAX_MAP_SERVERS];    // Map-server anti-freeze system. Cou
 static
 int anti_freeze_enable = 0;
 static
-std::chrono::seconds ANTI_FREEZE_INTERVAL = std::chrono::seconds(6);
+std::chrono::seconds anti_freeze_interval = std::chrono::seconds(6);
 
 constexpr
 std::chrono::milliseconds DEFAULT_AUTOSAVE_INTERVAL =
@@ -59,22 +59,14 @@ ServerName server_name;
 static
 CharName wisp_server_name = stringish<CharName>("Server");
 static
-IP_String login_ip_str;
-static
-int login_ip;
+IP4Address login_ip;
 static
 int login_port = 6900;
 static
-IP_String char_ip_str;
-static
-int char_ip;
+IP4Address char_ip;
 static
 int char_port = 6121;
 static
-int char_maintenance;
-static
-int char_new;
-static
 FString char_txt;
 static
 CharName unknown_char_name = stringish<CharName>("Unknown");
@@ -82,11 +74,9 @@ static
 FString char_log_filename = "log/char.log";
 //Added for lan support
 static
-IP_String lan_map_ip;
+IP4Address lan_map_ip;
 static
-uint8_t subneti[4];
-static
-uint8_t subnetmaski[4];
+IP4Mask lan_subnet;
 static
 int char_name_option = 0;      // Option to know which letters/symbols are authorised in the name of a character (0: all, 1: only those in char_name_letters, 2: all EXCEPT those in char_name_letters) by [Yor]
 static
@@ -110,7 +100,7 @@ struct AuthFifoEntry
     int account_id;
     int char_id;
     int login_id1, login_id2;
-    int ip;
+    IP4Address ip;
     int delflag;
     int sex;
     unsigned short packet_tmw_version;
@@ -131,13 +121,7 @@ std::vector<mmo_charstatus> char_data;
 static
 int max_connect_user = 0;
 static
-std::chrono::milliseconds autosave_interval = DEFAULT_AUTOSAVE_INTERVAL;
-static
-int start_zeny = 500;
-static
-int start_weapon = 1201;
-static
-int start_armor = 1202;
+std::chrono::milliseconds autosave_time = DEFAULT_AUTOSAVE_INTERVAL;
 
 // Initial position (it's possible to set it in conf file)
 static
@@ -666,10 +650,7 @@ mmo_charstatus *make_new_char(int fd, CharName name, const uint8_t (&stats)[6],
         return nullptr;
     }
 
-    char ip[16];
-    uint8_t *sin_addr = reinterpret_cast<uint8_t *>(&session[fd]->client_addr.sin_addr);
-    sprintf(ip, "%d.%d.%d.%d", sin_addr[0], sin_addr[1], sin_addr[2],
-             sin_addr[3]);
+    IP4Address ip = session[fd]->client_ip;
 
     CHAR_LOG("Creation of New Character: (connection #%d, account: %d) slot %d, character Name: %s, stats: %d+%d+%d+%d+%d+%d=%d, hair: %d, hair color: %d. [%s]\n",
          fd, sd->account_id, slot, name,
@@ -688,7 +669,7 @@ mmo_charstatus *make_new_char(int fd, CharName name, const uint8_t (&stats)[6],
     cd.job_level = 1;
     cd.base_exp = 0;
     cd.job_exp = 0;
-    cd.zeny = start_zeny;
+    cd.zeny = 0;
     cd.attrs[ATTR::STR] = stats[0];
     cd.attrs[ATTR::AGI] = stats[1];
     cd.attrs[ATTR::VIT] = stats[2];
@@ -1562,12 +1543,11 @@ void parse_frommap(int fd)
                     j++;
                 }
                 {
-                    uint8_t *p = reinterpret_cast<uint8_t *>(&server[id].ip);
-                    PRINTF("Map-Server %d connected: %d maps, from IP %d.%d.%d.%d port %d.\n",
-                         id, j, p[0], p[1], p[2], p[3], server[id].port);
+                    PRINTF("Map-Server %d connected: %d maps, from IP %s port %d.\n",
+                         id, j, server[id].ip, server[id].port);
                     PRINTF("Map-server %d loading complete.\n", id);
-                    CHAR_LOG("Map-Server %d connected: %d maps, from IP %d.%d.%d.%d port %d. Map-server %d loading complete.\n",
-                         id, j, p[0], p[1], p[2], p[3],
+                    CHAR_LOG("Map-Server %d connected: %d maps, from IP %s port %d. Map-server %d loading complete.\n",
+                         id, j, server[id].ip,
                          server[id].port, id);
                 }
                 WFIFOW(fd, 0) = 0x2afb;
@@ -1587,7 +1567,7 @@ void parse_frommap(int fd)
                     {
                         WBUFW(buf, 0) = 0x2b04;
                         WBUFW(buf, 2) = j * 16 + 10;
-                        WBUFL(buf, 4) = server[id].ip;
+                        WBUFIP(buf, 4) = server[id].ip;
                         WBUFW(buf, 8) = server[id].port;
                         // server[id].maps[i] = RFIFO_STRING(fd, 4 + i * 16)
                         for (int i = 0; i < j; ++i)
@@ -1600,7 +1580,7 @@ void parse_frommap(int fd)
                         if (server_fd[x] >= 0 && x != id)
                         {
                             WFIFOW(fd, 0) = 0x2b04;
-                            WFIFOL(fd, 4) = server[x].ip;
+                            WFIFOIP(fd, 4) = server[x].ip;
                             WFIFOW(fd, 8) = server[x].port;
                             j = 0;
                             for (int i = 0; i < MAX_MAP_PER_SERVER; i++)
@@ -1630,7 +1610,7 @@ void parse_frommap(int fd)
                         afi.login_id1 == RFIFOL(fd, 10) &&
                         // here, it's the only area where it's possible that we doesn't know login_id2 (map-server asks just after 0x72 packet, that doesn't given the value)
                         (afi.login_id2 == RFIFOL(fd, 14) || RFIFOL(fd, 14) == 0) &&  // relate to the versions higher than 18
-                        (!check_ip_flag || afi.ip == RFIFOL(fd, 18))
+                        (!check_ip_flag || afi.ip == RFIFOIP(fd, 18))
                         && !afi.delflag)
                     {
                         mmo_charstatus *cd = nullptr;
@@ -1732,7 +1712,7 @@ void parse_frommap(int fd)
                 auth_fifo_iter->login_id2 = RFIFOL(fd, 10);
                 auth_fifo_iter->delflag = 2;
                 auth_fifo_iter->connect_until_time = TimeT();    // unlimited/unknown time by default (not display in map-server)
-                auth_fifo_iter->ip = RFIFOL(fd, 14);
+                auth_fifo_iter->ip = RFIFOIP(fd, 14);
                 auth_fifo_iter++;
                 WFIFOW(fd, 0) = 0x2b03;
                 WFIFOL(fd, 2) = RFIFOL(fd, 2);
@@ -1758,7 +1738,7 @@ void parse_frommap(int fd)
                 auth_fifo_iter->delflag = 0;
                 auth_fifo_iter->sex = RFIFOB(fd, 44);
                 auth_fifo_iter->connect_until_time = TimeT();    // unlimited/unknown time by default (not display in map-server)
-                auth_fifo_iter->ip = RFIFOL(fd, 45);
+                auth_fifo_iter->ip = RFIFOIP(fd, 45);
 
                 // default, if not found in the loop
                 WFIFOW(fd, 6) = 1;
@@ -1774,28 +1754,6 @@ void parse_frommap(int fd)
                 RFIFOSKIP(fd, 49);
                 break;
 
-                // キャラ名検索
-            case 0x2b08:
-                if (RFIFOREST(fd) < 6)
-                    return;
-            {
-                CharName name = unknown_char_name;
-                for (const mmo_charstatus& cd : char_data)
-                {
-                    if (cd.char_id == RFIFOL(fd, 2))
-                    {
-                        name = cd.name;
-                        break;
-                    }
-                }
-                WFIFOW(fd, 0) = 0x2b09;
-                WFIFOL(fd, 2) = RFIFOL(fd, 2);
-                WFIFO_STRING(fd, 6, name.to__actual(), 24);
-                WFIFOSET(fd, 30);
-            }
-                RFIFOSKIP(fd, 6);
-                break;
-
                 // it is a request to become GM
             case 0x2b0a:
                 if (RFIFOREST(fd) < 4 || RFIFOREST(fd) < RFIFOW(fd, 2))
@@ -2038,33 +1996,18 @@ int search_mapserver(XString map)
 // Test to know if an IP come from LAN or WAN. by [Yor]
 //-----------------------------------------------------
 static
-int lan_ip_check(unsigned char *p)
+int lan_ip_check(IP4Address addr)
 {
-    int i;
-    int lancheck = 1;
+    bool lancheck = lan_subnet.covers(addr);
 
-//  PRINTF("lan_ip_check: to compare: %d.%d.%d.%d, network: %d.%d.%d.%d/%d.%d.%d.%d\n",
-//         p[0], p[1], p[2], p[3],
-//         subneti[0], subneti[1], subneti[2], subneti[3],
-//         subnetmaski[0], subnetmaski[1], subnetmaski[2], subnetmaski[3]);
-    for (i = 0; i < 4; i++)
-    {
-        if ((subneti[i] & subnetmaski[i]) != (p[i] & subnetmaski[i]))
-        {
-            lancheck = 0;
-            break;
-        }
-    }
     PRINTF("LAN test (result): %s source\033[0m.\n",
             (lancheck) ? "\033[1;36mLAN" : "\033[1;32mWAN");
     return lancheck;
 }
 
 static
-void handle_x0066(int fd, struct char_session_data *sd, uint8_t rfifob_2, uint8_t *p)
+void handle_x0066(int fd, struct char_session_data *sd, uint8_t rfifob_2, IP4Address ip)
 {
-    IP_String ip = ip2str(session[fd]->client_addr.sin_addr);
-
     {
         mmo_charstatus *cd = nullptr;
         for (mmo_charstatus& cdi : char_data)
@@ -2115,10 +2058,10 @@ void handle_x0066(int fd, struct char_session_data *sd, uint8_t rfifob_2, uint8_
                  cd->name,
                  sd->account_id, cd->char_num, ip);
             PRINTF("--Send IP of map-server. ");
-            if (lan_ip_check(p))
-                WFIFOL(fd, 22) = inet_addr(lan_map_ip.c_str());
+            if (lan_ip_check(ip))
+                WFIFOIP(fd, 22) = lan_map_ip;
             else
-                WFIFOL(fd, 22) = server[i].ip;
+                WFIFOIP(fd, 22) = server[i].ip;
             WFIFOW(fd, 26) = server[i].port;
             WFIFOSET(fd, 28);
             if (auth_fifo_iter == auth_fifo.end())
@@ -2130,7 +2073,7 @@ void handle_x0066(int fd, struct char_session_data *sd, uint8_t rfifob_2, uint8_
             auth_fifo_iter->delflag = 0;
             auth_fifo_iter->sex = sd->sex;
             auth_fifo_iter->connect_until_time = sd->connect_until_time;
-            auth_fifo_iter->ip = session[fd]->client_addr.sin_addr.s_addr;
+            auth_fifo_iter->ip = session[fd]->client_ip;
             auth_fifo_iter->packet_tmw_version = sd->packet_tmw_version;
             auth_fifo_iter++;
         }
@@ -2140,7 +2083,7 @@ void handle_x0066(int fd, struct char_session_data *sd, uint8_t rfifob_2, uint8_
 static
 void parse_char(int fd)
 {
-    uint8_t *p = reinterpret_cast<uint8_t *>(&session[fd]->client_addr.sin_addr);
+    IP4Address ip = session[fd]->client_ip;
 
     if (login_fd < 0 || session[fd]->eof)
     {                           // disconnect any player (already connected to char-server or coming back from map-server) if login-server is diconnected.
@@ -2213,7 +2156,7 @@ void parse_char(int fd)
                             && afi.login_id1 == sd->login_id1
                             && afi.login_id2 == sd->login_id2
                             && (!check_ip_flag
-                                || afi.ip == session[fd]->client_addr.sin_addr.s_addr)
+                                || afi.ip == session[fd]->client_ip)
                             && afi.delflag == 2)
                         {
                             afi.delflag = 1;
@@ -2253,8 +2196,7 @@ void parse_char(int fd)
                             WFIFOL(login_fd, 6) = sd->login_id1;
                             WFIFOL(login_fd, 10) = sd->login_id2;  // relate to the versions higher than 18
                             WFIFOB(login_fd, 14) = sd->sex;
-                            WFIFOL(login_fd, 15) =
-                                session[fd]->client_addr.sin_addr.s_addr;
+                            WFIFOIP(login_fd, 15) = session[fd]->client_ip;
                             WFIFOSET(login_fd, 19);
                         }
                         else
@@ -2272,7 +2214,7 @@ void parse_char(int fd)
             case 0x66:         // キャラ選択
                 if (!sd || RFIFOREST(fd) < 3)
                     return;
-                handle_x0066(fd, sd, RFIFOB(fd, 2), p);
+                handle_x0066(fd, sd, RFIFOB(fd, 2), ip);
                 RFIFOSKIP(fd, 3);
                 break;
 
@@ -2417,7 +2359,7 @@ void parse_char(int fd)
                     if (anti_freeze_enable)
                         server_freezeflag[i] = 5;   // Map anti-freeze system. Counter. 5 ok, 4...0 freezed
                     // ignore RFIFOL(fd, 50)
-                    server[i].ip = RFIFOL(fd, 54);
+                    server[i].ip = RFIFOIP(fd, 54);
                     server[i].port = RFIFOW(fd, 58);
                     server[i].users = 0;
                     for (MapName& mapi : server[i].maps)
@@ -2558,12 +2500,12 @@ void check_connect_login_server(TimerData *, tick_t)
         WFIFO_STRING(login_fd, 2, userid, 24);
         WFIFO_STRING(login_fd, 26, passwd, 24);
         WFIFOL(login_fd, 50) = 0;
-        WFIFOL(login_fd, 54) = char_ip;
+        WFIFOIP(login_fd, 54) = char_ip;
         WFIFOL(login_fd, 58) = char_port;
         WFIFO_STRING(login_fd, 60, server_name, 20);
         WFIFOW(login_fd, 80) = 0;
-        WFIFOW(login_fd, 82) = char_maintenance;
-        WFIFOW(login_fd, 84) = char_new;
+        WFIFOW(login_fd, 82) = 0; //char_maintenance;
+        WFIFOW(login_fd, 84) = 0; //char_new;
         WFIFOSET(login_fd, 86);
     }
 }
@@ -2577,13 +2519,8 @@ int lan_config_read(ZString lancfgName)
     struct hostent *h = NULL;
 
     // set default configuration
-    lan_map_ip = stringish<IP_String>("127.0.0.1");
-    subneti[0] = 127;
-    subneti[1] = 0;
-    subneti[2] = 0;
-    subneti[3] = 1;
-    for (int j = 0; j < 4; j++)
-        subnetmaski[j] = 255;
+    lan_map_ip = IP4_LOCALHOST;
+    lan_subnet = IP4Mask(IP4_LOCALHOST, IP4_BROADCAST);
 
     std::ifstream in(lancfgName.c_str());
 
@@ -2609,56 +2546,30 @@ int lan_config_read(ZString lancfgName)
             h = gethostbyname(w2.c_str());
             if (h != NULL)
             {
-                SNPRINTF(lan_map_ip, 16, "%d.%d.%d.%d",
-                         static_cast<uint8_t>(h->h_addr[0]),
-                         static_cast<uint8_t>(h->h_addr[1]),
-                         static_cast<uint8_t>(h->h_addr[2]),
-                         static_cast<uint8_t>(h->h_addr[3]));
+                lan_map_ip = IP4Address({
+                        static_cast<uint8_t>(h->h_addr[0]),
+                        static_cast<uint8_t>(h->h_addr[1]),
+                        static_cast<uint8_t>(h->h_addr[2]),
+                        static_cast<uint8_t>(h->h_addr[3]),
+                });
             }
             else
             {
-                lan_map_ip = stringish<IP_String>(w2);
+                PRINTF("Bad IP value: %s\n", line);
+                abort();
             }
             PRINTF("LAN IP of map-server: %s.\n", lan_map_ip);
         }
-        else if (w1 == "subnet")
-        {
-            // Read Subnetwork
-            for (int j = 0; j < 4; j++)
-                subneti[j] = 0;
-            h = gethostbyname(w2.c_str());
-            if (h != NULL)
-            {
-                for (int j = 0; j < 4; j++)
-                    subneti[j] = h->h_addr[j];
-            }
-            else
-            {
-                SSCANF(w2, "%hhu.%hhu.%hhu.%hhu", &subneti[0], &subneti[1],
-                        &subneti[2], &subneti[3]);
-            }
-            PRINTF("Sub-network of the map-server: %d.%d.%d.%d.\n",
-                    subneti[0], subneti[1], subneti[2], subneti[3]);
-        }
-        else if (w1 == "subnetmask")
+        else if (w1 == "subnet" /*backward compatibility*/
+                || w1 == "lan_subnet")
         {
-            // Read Subnetwork Mask
-            for (int j = 0; j < 4; j++)
-                subnetmaski[j] = 255;
-            h = gethostbyname(w2.c_str());
-            if (h != NULL)
+            if (!extract(w2, &lan_subnet))
             {
-                for (int j = 0; j < 4; j++)
-                    subnetmaski[j] = h->h_addr[j];
+                PRINTF("Bad IP mask: %s\n", line);
+                abort();
             }
-            else
-            {
-                SSCANF(w2, "%hhu.%hhu.%hhu.%hhu", &subnetmaski[0], &subnetmaski[1],
-                        &subnetmaski[2], &subnetmaski[3]);
-            }
-            PRINTF("Sub-network mask of the map-server: %d.%d.%d.%d.\n",
-                    subnetmaski[0], subnetmaski[1], subnetmaski[2],
-                    subnetmaski[3]);
+            PRINTF("Sub-network of the map-server: %s.\n",
+                    lan_subnet);
         }
         else
         {
@@ -2669,10 +2580,8 @@ int lan_config_read(ZString lancfgName)
 
     // sub-network check of the map-server
     {
-        unsigned char p[4];
-        SSCANF(lan_map_ip, "%hhu.%hhu.%hhu.%hhu", &p[0], &p[1], &p[2], &p[3]);
         PRINTF("LAN test of LAN IP of the map-server: ");
-        if (lan_ip_check(p) == 0)
+        if (!lan_ip_check(lan_map_ip))
         {
             PRINTF("\033[1;31m***ERROR: LAN IP of the map-server doesn't belong to the specified Sub-network.\033[0m\n");
         }
@@ -2723,16 +2632,20 @@ int char_config_read(ZString cfgName)
             h = gethostbyname(w2.c_str());
             if (h != NULL)
             {
-                SNPRINTF(login_ip_str, 16, "%d.%d.%d.%d",
+                login_ip = IP4Address({
                         static_cast<uint8_t>(h->h_addr[0]),
                         static_cast<uint8_t>(h->h_addr[1]),
                         static_cast<uint8_t>(h->h_addr[2]),
-                        static_cast<uint8_t>(h->h_addr[3]));
+                        static_cast<uint8_t>(h->h_addr[3]),
+                });
                 PRINTF("Login server IP address : %s -> %s\n",
-                        w2, login_ip_str);
+                        w2, login_ip);
             }
             else
-                login_ip_str = stringish<IP_String>(w2);
+            {
+                PRINTF("Bad IP value: %s\n", line);
+                abort();
+            }
         }
         else if (w1 == "login_port")
         {
@@ -2743,29 +2656,25 @@ int char_config_read(ZString cfgName)
             h = gethostbyname(w2.c_str());
             if (h != NULL)
             {
-                SNPRINTF(char_ip_str, 16, "%d.%d.%d.%d",
+                char_ip = IP4Address({
                         static_cast<uint8_t>(h->h_addr[0]),
                         static_cast<uint8_t>(h->h_addr[1]),
                         static_cast<uint8_t>(h->h_addr[2]),
-                        static_cast<uint8_t>(h->h_addr[3]));
+                        static_cast<uint8_t>(h->h_addr[3]),
+                });
                 PRINTF("Character server IP address : %s -> %s\n",
-                        w2, char_ip_str);
+                        w2, char_ip);
             }
             else
-                char_ip_str = stringish<IP_String>(w2);
+            {
+                PRINTF("Bad IP value: %s\n", line);
+                abort();
+            }
         }
         else if (w1 == "char_port")
         {
             char_port = atoi(w2.c_str());
         }
-        else if (w1 == "char_maintenance")
-        {
-            char_maintenance = atoi(w2.c_str());
-        }
-        else if (w1 == "char_new")
-        {
-            char_new = atoi(w2.c_str());
-        }
         else if (w1 == "char_txt")
         {
             char_txt = w2;
@@ -2782,32 +2691,14 @@ int char_config_read(ZString cfgName)
         }
         else if (w1 == "autosave_time")
         {
-            autosave_interval = std::chrono::seconds(atoi(w2.c_str()));
-            if (autosave_interval <= std::chrono::seconds::zero())
-                autosave_interval = DEFAULT_AUTOSAVE_INTERVAL;
+            autosave_time = std::chrono::seconds(atoi(w2.c_str()));
+            if (autosave_time <= std::chrono::seconds::zero())
+                autosave_time = DEFAULT_AUTOSAVE_INTERVAL;
         }
         else if (w1 == "start_point")
         {
             extract(w2, &start_point);
         }
-        else if (w1 == "start_zeny")
-        {
-            start_zeny = atoi(w2.c_str());
-            if (start_zeny < 0)
-                start_zeny = 0;
-        }
-        else if (w1 == "start_weapon")
-        {
-            start_weapon = atoi(w2.c_str());
-            if (start_weapon < 0)
-                start_weapon = 0;
-        }
-        else if (w1 == "start_armor")
-        {
-            start_armor = atoi(w2.c_str());
-            if (start_armor < 0)
-                start_armor = 0;
-        }
         else if (w1 == "unknown_char_name")
         {
             unknown_char_name = stringish<CharName>(w2);
@@ -2822,8 +2713,11 @@ int char_config_read(ZString cfgName)
         }
         else if (w1 == "char_name_letters")
         {
-            for (uint8_t c : w2)
-                char_name_letters[c] = true;
+            if (!w2)
+                char_name_letters.reset();
+            else
+                for (uint8_t c : w2)
+                    char_name_letters[c] = true;
         }
         else if (w1 == "online_txt_filename")
         {
@@ -2855,7 +2749,7 @@ int char_config_read(ZString cfgName)
         }
         else if (w1 == "anti_freeze_interval")
         {
-            ANTI_FREEZE_INTERVAL = std::max(
+            anti_freeze_interval = std::max(
                     std::chrono::seconds(atoi(w2.c_str())),
                     std::chrono::seconds(5));
         }
@@ -2909,9 +2803,6 @@ int do_init(int argc, ZString *argv)
     else
         lan_config_read(LOGIN_LAN_CONF_NAME);
 
-    login_ip = inet_addr(login_ip_str.c_str());
-    char_ip = inet_addr(char_ip_str.c_str());
-
     for (i = 0; i < MAX_MAP_SERVERS; i++)
     {
         server[i] = mmo_map_server{};
@@ -2941,16 +2832,16 @@ int do_init(int argc, ZString *argv)
             send_users_tologin,
             std::chrono::seconds(5)
     ).detach();
-    Timer(gettick() + autosave_interval,
+    Timer(gettick() + autosave_time,
             mmo_char_sync_timer,
-            autosave_interval
+            autosave_time
     ).detach();
 
     if (anti_freeze_enable > 0)
     {
         Timer(gettick() + std::chrono::seconds(1),
                 map_anti_freeze_system,
-                ANTI_FREEZE_INTERVAL
+                anti_freeze_interval
         ).detach();
     }
 
diff --git a/src/char/char.hpp b/src/char/char.hpp
index 8e37c64..abd5381 100644
--- a/src/char/char.hpp
+++ b/src/char/char.hpp
@@ -2,6 +2,7 @@
 #define CHAR_HPP
 
 #include "../common/const_array.hpp"
+#include "../common/ip.hpp"
 #include "../common/mmo.hpp"
 
 constexpr int MAX_MAP_SERVERS = 30;
@@ -12,7 +13,7 @@ constexpr int MAX_MAP_SERVERS = 30;
 
 struct mmo_map_server
 {
-    long ip;
+    IP4Address ip;
     short port;
     int users;
     MapName maps[MAX_MAP_PER_SERVER];
diff --git a/src/char/inter.cpp b/src/char/inter.cpp
index 3cb51e7..81c4a9d 100644
--- a/src/char/inter.cpp
+++ b/src/char/inter.cpp
@@ -26,8 +26,6 @@
 // that is the waiting time of answers of all map-servers
 constexpr std::chrono::minutes WISDATA_TTL = std::chrono::minutes(1);
 
-FString inter_log_filename = "log/inter.log";
-
 static
 FString accreg_txt = "save/accreg.txt";
 
@@ -203,10 +201,6 @@ int inter_config_read(ZString cfgName)
             if (party_share_level < 0)
                 party_share_level = 0;
         }
-        else if (w1 == "inter_log_filename")
-        {
-            inter_log_filename = w2;
-        }
         else if (w1 == "import")
         {
             inter_config_read(w2);
diff --git a/src/char/inter.hpp b/src/char/inter.hpp
index ce8447d..447ab53 100644
--- a/src/char/inter.hpp
+++ b/src/char/inter.hpp
@@ -12,6 +12,5 @@ int inter_check_length(int fd, int length);
 #define inter_cfgName "conf/inter_athena.conf"
 
 extern int party_share_level;
-extern FString inter_log_filename;
 
 #endif // INTER_HPP
diff --git a/src/common/ip.hpp b/src/common/ip.hpp
index e67056c..aceb765 100644
--- a/src/common/ip.hpp
+++ b/src/common/ip.hpp
@@ -21,6 +21,8 @@
 
 #include "sanity.hpp"
 
+#include <netinet/in.h>
+
 #include "extract.hpp"
 #include "strings.hpp"
 
@@ -53,6 +55,17 @@ public:
     IP4Address(const uint8_t (&a)[4])
     : _addr{a[0], a[1], a[2], a[3]}
     {}
+    explicit
+    IP4Address(struct in_addr addr)
+    {
+        static_assert(sizeof(addr) == sizeof(_addr), "4 bytes");
+        *this = IP4Address(reinterpret_cast<const uint8_t (&)[4]>(addr));
+    }
+    explicit
+    operator struct in_addr() const
+    {
+        return reinterpret_cast<const struct in_addr&>(_addr);
+    }
 
     constexpr friend
     IP4Address operator & (IP4Address l, IP4Address r)
diff --git a/src/common/md5calc.cpp b/src/common/md5calc.cpp
index ae134b7..1c48a24 100644
--- a/src/common/md5calc.cpp
+++ b/src/common/md5calc.cpp
@@ -327,26 +327,21 @@ bool pass_ok(AccountPass password, AccountCrypt crypted)
 
 // [M|h]ashes up an IP address and a secret key
 // to return a hopefully unique masked IP.
-struct in_addr MD5_ip(struct in_addr ip)
+IP4Address MD5_ip(IP4Address ip)
 {
     static SaltString secret = make_salt();
-    union
-    {
-        uint8_t bytes[4];
-        struct in_addr ip;
-    } conv;
 
     // MD5sum a secret + the IP address
     VString<31> ipbuf;
-    SNPRINTF(ipbuf, 32, "%u%s", ip.s_addr, secret);
+    SNPRINTF(ipbuf, 32, "%s %s", ip, secret);
     md5_binary obuf;
     MD5_to_bin(MD5_from_string(ipbuf), obuf);
 
     // Fold the md5sum to 32 bits, pack the bytes to an in_addr
-    conv.bytes[0] = obuf[0] ^ obuf[1] ^ obuf[8] ^ obuf[9];
-    conv.bytes[1] = obuf[2] ^ obuf[3] ^ obuf[10] ^ obuf[11];
-    conv.bytes[2] = obuf[4] ^ obuf[5] ^ obuf[12] ^ obuf[13];
-    conv.bytes[3] = obuf[6] ^ obuf[7] ^ obuf[14] ^ obuf[15];
-
-    return conv.ip;
+    return IP4Address({
+            static_cast<uint8_t>(obuf[0] ^ obuf[1] ^ obuf[8] ^ obuf[9]),
+            static_cast<uint8_t>(obuf[2] ^ obuf[3] ^ obuf[10] ^ obuf[11]),
+            static_cast<uint8_t>(obuf[4] ^ obuf[5] ^ obuf[12] ^ obuf[13]),
+            static_cast<uint8_t>(obuf[6] ^ obuf[7] ^ obuf[14] ^ obuf[15]),
+    });
 }
diff --git a/src/common/md5calc.hpp b/src/common/md5calc.hpp
index 98f44d6..70a996e 100644
--- a/src/common/md5calc.hpp
+++ b/src/common/md5calc.hpp
@@ -11,6 +11,7 @@
 
 #include <array>
 
+#include "ip.hpp"
 #include "mmo.hpp"
 #include "strings.hpp"
 
@@ -53,7 +54,7 @@ SaltString make_salt(void);
 /// check plaintext password against saved saltcrypt
 bool pass_ok(AccountPass password, AccountCrypt crypted);
 
-/// This returns an in_addr because it is configurable whether it gets called at all
-struct in_addr MD5_ip(struct in_addr ip);
+/// This returns an IP4Address because it is configurable whether it gets called at all
+IP4Address MD5_ip(IP4Address ip);
 
 #endif // MD5CALC_HPP
diff --git a/src/common/socket.cpp b/src/common/socket.cpp
index 4655d1d..c7e6ed2 100644
--- a/src/common/socket.cpp
+++ b/src/common/socket.cpp
@@ -174,7 +174,7 @@ void connect_client(int listen_fd)
     session[fd]->func_recv = recv_to_fifo;
     session[fd]->func_send = send_from_fifo;
     session[fd]->func_parse = default_func_parse;
-    session[fd]->client_addr = client_address;
+    session[fd]->client_ip = IP4Address(client_address.sin_addr);
     session[fd]->created = TimeT::now();
     session[fd]->connected = 0;
 }
@@ -240,7 +240,7 @@ int make_listen_port(uint16_t port)
     return fd;
 }
 
-int make_connection(uint32_t ip, uint16_t port)
+int make_connection(IP4Address ip, uint16_t port)
 {
     struct sockaddr_in server_address;
     int fd = socket(AF_INET, SOCK_STREAM, 0);
@@ -264,7 +264,7 @@ int make_connection(uint32_t ip, uint16_t port)
     setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &yes, sizeof yes);
 
     server_address.sin_family = AF_INET;
-    server_address.sin_addr.s_addr = ip;
+    server_address.sin_addr = in_addr(ip);
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wold-style-cast"
 #if __GNUC__ > 4 || __GNUC_MINOR__ >= 8
diff --git a/src/common/socket.hpp b/src/common/socket.hpp
index dd1c872..91a8c49 100644
--- a/src/common/socket.hpp
+++ b/src/common/socket.hpp
@@ -10,6 +10,7 @@
 # include <array>
 
 # include "dumb_ptr.hpp"
+# include "ip.hpp"
 # include "utils.hpp"
 # include "timer.t.hpp"
 
@@ -43,7 +44,7 @@ struct socket_data
     /// Note that there is no need for a wdata_pos
     size_t rdata_pos;
 
-    struct sockaddr_in client_addr;
+    IP4Address client_ip;
 
     /// Send or recieve
     /// Only called when select() indicates the socket is ready
@@ -78,7 +79,7 @@ extern int fd_max;
 int make_listen_port(uint16_t port);
 /// Connect to an address, return a connected socket or -1
 // FIXME - this is IPv4 only!
-int make_connection(uint32_t ip, uint16_t port);
+int make_connection(IP4Address ip, uint16_t port);
 /// free() the structure and close() the fd
 void delete_session(int);
 /// Make a the internal queues bigger
@@ -143,6 +144,13 @@ void RFIFO_STRUCT(int fd, size_t pos, T& structure)
 {
     really_memcpy(pod_addressof_m(structure), static_cast<const uint8_t *>(RFIFOP(fd, pos)), sizeof(T));
 }
+inline
+IP4Address RFIFOIP(int fd, size_t pos)
+{
+    IP4Address o;
+    RFIFO_STRUCT(fd, pos, o);
+    return o;
+}
 template<uint8_t len>
 inline
 VString<len-1> RFIFO_STRING(int fd, size_t pos)
@@ -195,6 +203,13 @@ void RBUF_STRUCT(const uint8_t *p, size_t pos, T& structure)
 {
     really_memcpy(pod_addressof_m(structure), p + pos, sizeof(T));
 }
+inline
+IP4Address RBUFIP(const uint8_t *p, size_t pos)
+{
+    IP4Address o;
+    RBUF_STRUCT(p, pos, o);
+    return o;
+}
 template<uint8_t len>
 inline
 VString<len-1> RBUF_STRING(const uint8_t *p, size_t pos)
@@ -248,6 +263,12 @@ void WFIFO_STRUCT(int fd, size_t pos, T& structure)
     really_memcpy(static_cast<uint8_t *>(WFIFOP(fd, pos)), pod_addressof_c(structure), sizeof(T));
 }
 inline
+IP4Address& WFIFOIP(int fd, size_t pos)
+{
+    static_assert(is_trivially_copyable<IP4Address>::value, "That was the whole point");
+    return *static_cast<IP4Address *>(WFIFOP(fd, pos));
+}
+inline
 void WFIFO_STRING(int fd, size_t pos, XString s, size_t len)
 {
     char *const begin = static_cast<char *>(WFIFOP(fd, pos));
@@ -298,6 +319,11 @@ void WBUF_STRUCT(uint8_t *p, size_t pos, T& structure)
     really_memcpy(p + pos, pod_addressof_c(structure), sizeof(T));
 }
 inline
+IP4Address& WBUFIP(uint8_t *p, size_t pos)
+{
+    return *static_cast<IP4Address *>(WBUFP(p, pos));
+}
+inline
 void WBUF_STRING(uint8_t *p, size_t pos, XString s, size_t len)
 {
     char *const begin = static_cast<char *>(WBUFP(p, pos));
diff --git a/src/common/utils.cpp b/src/common/utils.cpp
index c9c22b9..9ab470b 100644
--- a/src/common/utils.cpp
+++ b/src/common/utils.cpp
@@ -44,11 +44,11 @@ bool e_mail_check(XString email)
 //-------------------------------------------------
 int config_switch (ZString str)
 {
-    if (str == "on" || str == "yes"
+    if (str == "true" || str == "on" || str == "yes"
         || str == "oui" || str == "ja"
         || str == "si")
         return 1;
-    if (str == "off" || str == "no"
+    if (str == "false" || str == "off" || str == "no"
         || str == "non" || str == "nein")
         return 0;
 
@@ -59,22 +59,6 @@ int config_switch (ZString str)
     abort();
 }
 
-IP_String ip2str(struct in_addr ip)
-{
-    const uint8_t *p = reinterpret_cast<const uint8_t *>(&ip);
-
-    IP_String out;
-    SNPRINTF(out, 16, "%d.%d.%d.%d", p[0], p[1], p[2], p[3]);
-    return out;
-}
-VString<16> ip2str_extradot(struct in_addr ip)
-{
-    const uint8_t *p = reinterpret_cast<const uint8_t *>(&ip);
-    VString<16> out;
-    SNPRINTF(out, 17, "%d.%d.%d.%d.", p[0], p[1], p[2], p[3]);
-    return out;
-}
-
 bool split_key_value(const FString& line, SString *w1, TString *w2)
 {
     FString::iterator begin = line.begin(), end = line.end();
diff --git a/src/common/utils.hpp b/src/common/utils.hpp
index 196bb3e..4f6190a 100644
--- a/src/common/utils.hpp
+++ b/src/common/utils.hpp
@@ -13,8 +13,6 @@
 #include "strings.hpp"
 #include "utils2.hpp"
 
-struct IP_String : VString<15> {};
-
 template<class T>
 struct is_trivially_copyable
 : std::integral_constant<bool,
@@ -26,8 +24,6 @@ struct is_trivially_copyable
 
 bool e_mail_check(XString email);
 int config_switch (ZString str);
-IP_String ip2str(struct in_addr ip);
-VString<15 + 1> ip2str_extradot(struct in_addr ip);
 
 bool split_key_value(const FString& line, SString *w1, TString *w2);
 
diff --git a/src/ladmin/ladmin.cpp b/src/ladmin/ladmin.cpp
index 12d9390..e0860b2 100644
--- a/src/ladmin/ladmin.cpp
+++ b/src/ladmin/ladmin.cpp
@@ -36,11 +36,11 @@ int eathena_interactive_session;
 //   (see login_athena.conf, 'admin_state' parameter)
 //-------------------------------------------------------------------------
 static
-IP_String loginserverip = stringish<IP_String>("127.0.0.1");   // IP of login-server
+IP4Address login_ip = IP4_LOCALHOST;   // IP of login-server
 static
-int loginserverport = 6900;    // Port of login-server
+int login_port = 6900;    // Port of login-server
 static
-AccountPass loginserveradminpassword = stringish<AccountPass>("admin");    // Administration password
+AccountPass admin_pass = stringish<AccountPass>("admin");    // Administration password
 static
 FString ladmin_log_filename = "log/ladmin.log";
 //-------------------------------------------------------------------------
@@ -226,8 +226,6 @@ FString ladmin_log_filename = "log/ladmin.log";
 static
 int login_fd;
 static
-int login_ip;
-static
 int bytes_to_read = 0;         // flag to know if we waiting bytes from login-server
 static
 TString parameters; // needs to be global since it's passed to the parse function
@@ -1903,9 +1901,9 @@ void parse_fromlogin(int fd)
     if (session[fd]->eof)
     {
         PRINTF("Impossible to have a connection with the login-server [%s:%d] !\n",
-             loginserverip, loginserverport);
+                login_ip, login_port);
         LADMIN_LOG("Impossible to have a connection with the login-server [%s:%d] !\n",
-              loginserverip, loginserverport);
+                login_ip, login_port);
         delete_session(fd);
         exit(0);
     }
@@ -1945,8 +1943,8 @@ void parse_fromlogin(int fd)
                 if (RFIFOREST(fd) < 10)
                     return;
             {
-                Iprintf("  Login-Server [%s:%d]\n", loginserverip,
-                         loginserverport);
+                Iprintf("  Login-Server [%s:%d]\n",
+                        login_ip, login_port);
                 Version version;
                 RFIFO_STRUCT(login_fd, 2, version);
                 Iprintf("  tmwA version %hhu.%hhu.%hhu (dev? %hhu) (flags %hhx) (which %hhx) (vend %hu)\n",
@@ -2608,7 +2606,7 @@ void parse_fromlogin(int fd)
                     int state = RFIFOL(fd, 36);
                     timestamp_seconds_buffer error_message = stringish<timestamp_seconds_buffer>(RFIFO_STRING<20>(fd, 40));
                     timestamp_milliseconds_buffer lastlogin = stringish<timestamp_milliseconds_buffer>(RFIFO_STRING<24>(fd, 60));
-                    IP_String last_ip = stringish<IP_String>(RFIFO_STRING<16>(fd, 84));
+                    VString<15> last_ip_ = RFIFO_STRING<16>(fd, 84);
                     AccountEmail email = stringish<AccountEmail>(RFIFO_STRING<40>(fd, 100));
                     TimeT connect_until_time = static_cast<time_t>(RFIFOL(fd, 140));
                     TimeT ban_until_time = static_cast<time_t>(RFIFOL(fd, 144));
@@ -2703,7 +2701,7 @@ void parse_fromlogin(int fd)
                             PRINTF(" Count:  %d connection.\n",
                                     connections);
                         PRINTF(" Last connection at: %s (ip: %s)\n",
-                                lastlogin, last_ip);
+                                lastlogin, last_ip_);
                         if (!connect_until_time)
                         {
                             PRINTF(" Validity limit: unlimited.\n");
@@ -2743,13 +2741,13 @@ int Connect_login_server(void)
     Iprintf("Attempt to connect to login-server...\n");
     LADMIN_LOG("Attempt to connect to login-server...\n");
 
-    if ((login_fd = make_connection(login_ip, loginserverport)) < 0)
+    if ((login_fd = make_connection(login_ip, login_port)) < 0)
         return 0;
 
     {
         WFIFOW(login_fd, 0) = 0x7918;  // Request for administation login
         WFIFOW(login_fd, 2) = 0;   // no encrypted
-        WFIFO_STRING(login_fd, 4, loginserveradminpassword, 24);
+        WFIFO_STRING(login_fd, 4, admin_pass, 24);
         WFIFOSET(login_fd, 28);
         bytes_to_read = 1;
 
@@ -2788,28 +2786,23 @@ int ladmin_config_read(ZString cfgName)
             struct hostent *h = gethostbyname(w2.c_str());
             if (h != NULL)
             {
-                Iprintf("Login server IP address: %s -> %d.%d.%d.%d\n",
-                        w2,
+                Iprintf("Login server IP address: %s -> %s\n",
+                        w2, login_ip);
+                login_ip = IP4Address({
                         static_cast<uint8_t>(h->h_addr[0]),
                         static_cast<uint8_t>(h->h_addr[1]),
                         static_cast<uint8_t>(h->h_addr[2]),
-                        static_cast<uint8_t>(h->h_addr[3]));
-                SNPRINTF(loginserverip, 16, "%d.%d.%d.%d",
-                        static_cast<uint8_t>(h->h_addr[0]),
-                        static_cast<uint8_t>(h->h_addr[1]),
-                        static_cast<uint8_t>(h->h_addr[2]),
-                        static_cast<uint8_t>(h->h_addr[3]));
+                        static_cast<uint8_t>(h->h_addr[3]),
+                });
             }
-            else
-                loginserverip = stringish<IP_String>(w2);
         }
         else if (w1 == "login_port")
         {
-            loginserverport = atoi(w2.c_str());
+            login_port = atoi(w2.c_str());
         }
         else if (w1 == "admin_pass")
         {
-            loginserveradminpassword = stringish<AccountPass>(w2);
+            admin_pass = stringish<AccountPass>(w2);
         }
         else if (w1 == "ladmin_log_filename")
         {
@@ -2825,8 +2818,6 @@ int ladmin_config_read(ZString cfgName)
         }
     }
 
-    login_ip = inet_addr(loginserverip.c_str());
-
     Iprintf("---End reading of Ladmin configuration file.\n");
 
     return 0;
diff --git a/src/login/login.cpp b/src/login/login.cpp
index b0b3137..8d79158 100644
--- a/src/login/login.cpp
+++ b/src/login/login.cpp
@@ -56,11 +56,9 @@ struct mmo_account
 struct mmo_char_server
 {
     ServerName name;
-    long ip;
-    short port;
-    int users;
-    int maintenance;
-    int is_new;
+    IP4Address ip;
+    uint16_t port;
+    uint16_t users;
 };
 
 static
@@ -68,15 +66,13 @@ int account_id_count = START_ACCOUNT_NUM;
 static
 int server_num;
 static
-int new_account_flag = 0;
+int new_account = 0;
 static
 int login_port = 6900;
 static
-IP_String lan_char_ip;
+IP4Address lan_char_ip;
 static
-uint8_t subneti[4];
-static
-uint8_t subnetmaski[4];
+IP4Mask lan_subnet;
 static
 FString update_host;
 static
@@ -85,7 +81,7 @@ ServerName main_server;
 static
 FString account_filename = "save/account.txt";
 static
-FString GM_account_filename = "conf/GM_account.txt";
+FString gm_account_filename = "conf/GM_account.txt";
 static
 FString login_log_filename = "log/login.log";
 static
@@ -113,7 +109,7 @@ int server_freezeflag[MAX_SERVERS];    // Char-server anti-freeze system. Counte
 static
 int anti_freeze_enable = 0;
 static
-std::chrono::seconds ANTI_FREEZE_INTERVAL = std::chrono::seconds(15);
+std::chrono::seconds anti_freeze_interval = std::chrono::seconds(15);
 
 static
 int login_fd;
@@ -122,16 +118,13 @@ enum class ACO
 {
     DENY_ALLOW,
     ALLOW_DENY,
-    MUTUAL_FAILTURE,
+    MUTUAL_FAILURE,
 };
 
-// TODO: port the new code for this
-struct AccessEntry : VString<127> {};
-
 static
 ACO access_order = ACO::DENY_ALLOW;
 static
-std::vector<AccessEntry>
+std::vector<IP4Mask>
 access_allow, access_deny, access_ladmin;
 
 static
@@ -155,7 +148,8 @@ constexpr int AUTH_FIFO_SIZE = 256;
 struct
 {
     int account_id, login_id1, login_id2;
-    int ip, sex, delflag;
+    IP4Address ip;
+    int sex, delflag;
 } auth_fifo[AUTH_FIFO_SIZE];
 static
 int auth_fifo_pos = 0;
@@ -172,7 +166,7 @@ struct AuthData
     timestamp_seconds_buffer error_message;     // Message of error code #6 = Your are Prohibited to log in until %s (packet 0x006a)
     TimeT ban_until_time;      // # of seconds 1/1/1970 (timestamp): ban time limit of the account (0 = no ban)
     TimeT connect_until_time;  // # of seconds 1/1/1970 (timestamp): Validity limit of the account (0 = unlimited)
-    IP_String last_ip;           // save of last IP of connection
+    IP4Address last_ip;           // save of last IP of connection
     VString<254> memo;             // a memo field
     int account_reg2_num;
     struct global_reg account_reg2[ACCOUNT_REG2_NUM];
@@ -250,15 +244,15 @@ int read_gm_account(void)
 
     gm_account_db.clear();
 
-    creation_time_GM_account_file = file_modified(GM_account_filename);
+    creation_time_GM_account_file = file_modified(gm_account_filename);
 
-    if ((fp = fopen(GM_account_filename.c_str(), "r")) == NULL)
+    if ((fp = fopen(gm_account_filename.c_str(), "r")) == NULL)
     {
         PRINTF("read_gm_account: GM accounts file [%s] not found.\n",
-                GM_account_filename);
+                gm_account_filename);
         PRINTF("                 Actually, there is no GM accounts on the server.\n");
         LOGIN_LOG("read_gm_account: GM accounts file [%s] not found.\n",
-                   GM_account_filename);
+                   gm_account_filename);
         LOGIN_LOG("                 Actually, there is no GM accounts on the server.\n");
         return 1;
     }
@@ -272,16 +266,16 @@ int read_gm_account(void)
         if (sscanf(line, "%d %hhu", &p.account_id, &p.level) != 2
             && sscanf(line, "%d: %hhu", &p.account_id, &p.level) != 2)
             PRINTF("read_gm_account: file [%s], invalid 'id_acount level' format.\n",
-                 GM_account_filename);
+                 gm_account_filename);
         else if (p.level <= 0)
             PRINTF("read_gm_account: file [%s] %dth account (invalid level [0 or negative]: %d).\n",
-                 GM_account_filename, c + 1, p.level);
+                 gm_account_filename, c + 1, p.level);
         else
         {
             if (p.level > 99)
             {
                 PRINTF("read_gm_account: file [%s] %dth account (invalid level, but corrected: %d->99).\n",
-                     GM_account_filename, c + 1, p.level);
+                     gm_account_filename, c + 1, p.level);
                 p.level = 99;
             }
             if ((GM_level = isGM(p.account_id)) > 0)
@@ -312,57 +306,18 @@ int read_gm_account(void)
     fclose(fp);
 
     PRINTF("read_gm_account: file '%s' readed (%d GM accounts found).\n",
-            GM_account_filename, c);
+            gm_account_filename, c);
     LOGIN_LOG("read_gm_account: file '%s' readed (%d GM accounts found).\n",
-               GM_account_filename, c);
+               gm_account_filename, c);
 
     return 0;
 }
 
-//--------------------------------------------------------------
-// Test of the IP mask
-// (ip: IP to be tested, str: mask x.x.x.x/# or x.x.x.x/y.y.y.y)
-//--------------------------------------------------------------
-static
-int check_ipmask(struct in_addr ip, ZString str)
-{
-    unsigned int mask = 0, ip2;
-    uint8_t *p = reinterpret_cast<uint8_t *>(&ip2),
-                  *p2 = reinterpret_cast<uint8_t *>(&mask);
-    int i = 0;
-    unsigned int m;
-
-    if (SSCANF(str, "%hhu.%hhu.%hhu.%hhu/%n",
-                &p[0], &p[1], &p[2], &p[3], &i) != 4
-            || i == 0)
-        return 0;
-
-    if (SSCANF(str.oslice_t(i), "%hhu.%hhu.%hhu.%hhu",
-                &p2[0], &p2[1], &p2[2], &p2[3]) == 4)
-    {
-        mask = ntohl(mask);
-    }
-    else if (SSCANF(str.oslice_t(i), "%u", &m) == 1 && m <= 32)
-    {
-        for (i = 0; i < m && i < 32; i++)
-            mask = (mask >> 1) | 0x80000000;
-    }
-    else
-    {
-        PRINTF("check_ipmask: invalid mask [%s].\n", str);
-        return 0;
-    }
-
-//  PRINTF("Tested IP: %08x, network: %08x, network mask: %08x\n",
-//         (unsigned int)ntohl(ip), (unsigned int)ntohl(ip2), (unsigned int)mask);
-    return ((ntohl(ip.s_addr) & mask) == (ntohl(ip2) & mask));
-}
-
 //---------------------
 // Access control by IP
 //---------------------
 static
-bool check_ip(struct in_addr ip)
+bool check_ip(IP4Address ip)
 {
     enum class ACF
     {
@@ -376,33 +331,26 @@ bool check_ip(struct in_addr ip)
         return 1;
     // When there is no restriction, all IP are authorised.
 
-//  +   012.345.: front match form, or
-//      all: all IP are matched, or
-//      012.345.678.901/24: network form (mask with # of bits), or
-//      012.345.678.901/255.255.255.0: network form (mask with ip mask)
-//  +   Note about the DNS resolution (like www.ne.jp, etc.):
-//      There is no guarantee to have an answer.
-//      If we have an answer, there is no guarantee to have a 100% correct value.
-//      And, the waiting time (to check) can be long (over 1 minute to a timeout). That can block the software.
-//      So, DNS notation isn't authorised for ip checking.
-    VString<16> buf = ip2str_extradot(ip);
-
-    for (const AccessEntry& ae : access_allow)
+    if (std::find_if(access_allow.begin(), access_allow.end(),
+                [&ip](IP4Mask m)
+                {
+                    return m.covers(ip);
+                }) != access_allow.end())
     {
-#warning "TODO use an IPAddress4 and IPMask4 class"
-        if (buf.startswith(ae) || check_ipmask(ip, ae))
         {
             flag = ACF::ALLOW;
             if (access_order == ACO::ALLOW_DENY)
                 // With 'allow, deny' (deny if not allow), allow has priority
                 return 1;
-            break;
         }
     }
 
-    for (const AccessEntry& ae : access_deny)
+    if (std::find_if(access_deny.begin(), access_deny.end(),
+                [&ip](IP4Mask m)
+                {
+                    return m.covers(ip);
+                }) != access_deny.end())
     {
-        if (buf.startswith(ae) || check_ipmask(ip, ae))
         {
             flag = ACF::DENY;
             return 0;
@@ -421,30 +369,17 @@ bool check_ip(struct in_addr ip)
 // Access control by IP for ladmin
 //--------------------------------
 static
-bool check_ladminip(struct in_addr ip)
+bool check_ladminip(IP4Address ip)
 {
     if (access_ladmin.empty())
         // When there is no restriction, all IP are authorised.
         return true;
 
-//  +   012.345.: front match form, or
-//      all: all IP are matched, or
-//      012.345.678.901/24: network form (mask with # of bits), or
-//      012.345.678.901/255.255.255.0: network form (mask with ip mask)
-//  +   Note about the DNS resolution (like www.ne.jp, etc.):
-//      There is no guarantee to have an answer.
-//      If we have an answer, there is no guarantee to have a 100% correct value.
-//      And, the waiting time (to check) can be long (over 1 minute to a timeout). That can block the software.
-//      So, DNS notation isn't authorised for ip checking.
-    VString<16> buf = ip2str_extradot(ip);
-
-    for (const AccessEntry& ae : access_ladmin)
-    {
-        if (buf.startswith(ae) || check_ipmask(ip, ae))
-            return true;
-    }
-
-    return false;
+    return std::find_if(access_ladmin.begin(), access_ladmin.end(),
+            [&ip](IP4Mask m)
+            {
+                return m.covers(ip);
+            }) != access_ladmin.end();
 }
 
 //-----------------------------------------------
@@ -513,6 +448,7 @@ bool extract(XString line, AuthData *ad)
 {
     std::vector<struct global_reg> vars;
     VString<1> sex;
+    VString<15> ip;
     if (!extract(line,
                 record<'\t'>(
                     &ad->account_id,
@@ -525,11 +461,14 @@ bool extract(XString line, AuthData *ad)
                     &ad->email,
                     &ad->error_message,
                     &ad->connect_until_time,
-                    &ad->last_ip,
+                    &ip,
                     &ad->memo,
                     &ad->ban_until_time,
                     vrec<' '>(&vars))))
         return false;
+    ad->last_ip = IP4Address();
+    if (ip != "-" && !extract(ip, &ad->last_ip))
+        return false;
     if (ad->account_id > END_ACCOUNT_NUM)
         return false;
     for (const AuthData& adi : auth_data)
@@ -767,7 +706,7 @@ void check_GM_file(TimerData *, tick_t)
         return;
 
     // get last modify time/date
-    tick_t new_time = file_modified(GM_account_filename);
+    tick_t new_time = file_modified(gm_account_filename);
 
     if (new_time != creation_time_GM_account_file)
     {
@@ -814,7 +753,7 @@ int mmo_auth_new(struct mmo_account *account, char sex, AccountEmail email)
         ad.connect_until_time = timestamp;
     }
 
-    ad.last_ip = stringish<IP_String>("-");
+    ad.last_ip = IP4Address();
     ad.memo = "!";
     ad.account_reg2_num = 0;
     auth_data.push_back(ad);
@@ -830,12 +769,12 @@ int mmo_auth(struct mmo_account *account, int fd)
 {
     char new_account_sex = '\0';
 
-    IP_String ip = ip2str(session[fd]->client_addr.sin_addr);
+    IP4Address ip = session[fd]->client_ip;
 
     // Account creation with _M/_F
     if (account->passwdenc == 0
         && (account->userid.endswith("_F") || account->userid.endswith("_M"))
-        && new_account_flag == 1 && account_id_count <= END_ACCOUNT_NUM
+        && new_account == 1 && account_id_count <= END_ACCOUNT_NUM
         && (account->userid.size() - 2) >= 4 && account->passwd.size() >= 4)
     {
         new_account_sex = account->userid.back();
@@ -983,7 +922,7 @@ void char_anti_freeze_system(TimerData *, tick_t)
 static
 void parse_fromchar(int fd)
 {
-    IP_String ip = ip2str(session[fd]->client_addr.sin_addr);
+    IP4Address ip = session[fd]->client_ip;
 
     int id;
     for (id = 0; id < MAX_SERVERS; id++)
@@ -1034,7 +973,7 @@ void parse_fromchar(int fd)
                             auth_fifo[i].login_id2 == RFIFOL(fd, 10) &&    // relate to the versions higher than 18
                             auth_fifo[i].sex == RFIFOB(fd, 14) &&
                             (!check_ip_flag
-                             || auth_fifo[i].ip == RFIFOL(fd, 15))
+                             || auth_fifo[i].ip == RFIFOIP(fd, 15))
                             && !auth_fifo[i].delflag)
                         {
                             int p;
@@ -1179,7 +1118,7 @@ void parse_fromchar(int fd)
                             if (level_new_gm > 0)
                             {
                                 // if we can open the file to add the new GM
-                                if ((fp = fopen(GM_account_filename.c_str(), "a")) != NULL)
+                                if ((fp = fopen(gm_account_filename.c_str(), "a")) != NULL)
                                 {
                                     timestamp_seconds_buffer tmpstr;
                                     stamp_time(tmpstr);
@@ -1632,7 +1571,7 @@ void parse_fromchar(int fd)
 static
 void parse_admin(int fd)
 {
-    IP_String ip = ip2str(session[fd]->client_addr.sin_addr);
+    IP4Address ip = session[fd]->client_ip;
 
     if (session[fd]->eof)
     {
@@ -1911,12 +1850,12 @@ void parse_admin(int fd)
                 {
                     if (server_fd[i] >= 0)
                     {
-                        WFIFOL(fd, 4 + server_num * 32) = server[i].ip;
+                        WFIFOIP(fd, 4 + server_num * 32) = server[i].ip;
                         WFIFOW(fd, 4 + server_num * 32 + 4) = server[i].port;
                         WFIFO_STRING(fd, 4 + server_num * 32 + 6, server[i].name, 20);
                         WFIFOW(fd, 4 + server_num * 32 + 26) = server[i].users;
-                        WFIFOW(fd, 4 + server_num * 32 + 28) = server[i].maintenance;
-                        WFIFOW(fd, 4 + server_num * 32 + 30) = server[i].is_new;
+                        WFIFOW(fd, 4 + server_num * 32 + 28) = 0; //maintenance;
+                        WFIFOW(fd, 4 + server_num * 32 + 30) = 0; //is_new;
                         server_num++;
                     }
                 }
@@ -2057,9 +1996,9 @@ void parse_admin(int fd)
                                 char line[512];
                                 int GM_account, GM_level;
                                 int modify_flag;
-                                if ((fp2 = lock_fopen(GM_account_filename, &lock)) != NULL)
+                                if ((fp2 = lock_fopen(gm_account_filename, &lock)) != NULL)
                                 {
-                                    if ((fp = fopen(GM_account_filename.c_str(), "r")) != NULL)
+                                    if ((fp = fopen(gm_account_filename.c_str(), "r")) != NULL)
                                     {
                                         timestamp_seconds_buffer tmpstr;
                                         stamp_time(tmpstr);
@@ -2129,7 +2068,7 @@ void parse_admin(int fd)
                                              ad->userid, acc,
                                              new_gm_level, ip);
                                     }
-                                    lock_fclose(fp2, GM_account_filename, &lock);
+                                    lock_fclose(fp2, gm_account_filename, &lock);
                                     WFIFOL(fd, 2) = acc;
                                     LOGIN_LOG("'ladmin': Modification of a GM level (account: %s (%d), new GM level: %d, ip: %s)\n",
                                          ad->userid, acc,
@@ -2540,7 +2479,7 @@ void parse_admin(int fd)
                         else
                         {
                             TimeT now = TimeT::now();
-                            TimeT timestamp;
+                            TimeT timestamp = ad->connect_until_time;
                             if (!timestamp || timestamp < now)
                                 timestamp = now;
                             struct tm tmtime = timestamp;
@@ -2627,7 +2566,7 @@ void parse_admin(int fd)
                     WFIFOL(fd, 36) = ad->state;
                     WFIFO_STRING(fd, 40, ad->error_message, 20);
                     WFIFO_STRING(fd, 60, ad->lastlogin, 24);
-                    WFIFO_STRING(fd, 84, ad->last_ip, 16);
+                    WFIFO_STRING(fd, 84, convert_for_printf(ad->last_ip), 16);
                     WFIFO_STRING(fd, 100, ad->email, 40);
                     WFIFOL(fd, 140) = static_cast<time_t>(ad->connect_until_time);
                     WFIFOL(fd, 144) = static_cast<time_t>(ad->ban_until_time);
@@ -2670,7 +2609,7 @@ void parse_admin(int fd)
                         WFIFOL(fd, 36) = ad.state;
                         WFIFO_STRING(fd, 40, ad.error_message, 20);
                         WFIFO_STRING(fd, 60, ad.lastlogin, 24);
-                        WFIFO_STRING(fd, 84, ad.last_ip, 16);
+                        WFIFO_STRING(fd, 84, convert_for_printf(ad.last_ip), 16);
                         WFIFO_STRING(fd, 100, ad.email, 40);
                         WFIFOL(fd, 140) = static_cast<time_t>(ad.connect_until_time);
                         WFIFOL(fd, 144) = static_cast<time_t>(ad.ban_until_time);
@@ -2765,25 +2704,11 @@ void parse_admin(int fd)
 //--------------------------------------------
 // Test to know if an IP come from LAN or WAN.
 //--------------------------------------------
-// TODO fix to not take a ptr-to-uint8_t
 static
-int lan_ip_check(unsigned char *p)
+bool lan_ip_check(IP4Address p)
 {
-    int i;
-    int lancheck = 1;
+    bool lancheck = lan_subnet.covers(p);
 
-//  PRINTF("lan_ip_check: to compare: %d.%d.%d.%d, network: %d.%d.%d.%d/%d.%d.%d.%d\n",
-//         p[0], p[1], p[2], p[3],
-//         subneti[0], subneti[1], subneti[2], subneti[3],
-//         subnetmaski[0], subnetmaski[1], subnetmaski[2], subnetmaski[3]);
-    for (i = 0; i < 4; i++)
-    {
-        if ((subneti[i] & subnetmaski[i]) != (p[i] & subnetmaski[i]))
-        {
-            lancheck = 0;
-            break;
-        }
-    }
     PRINTF("LAN test (result): %s source\033[0m.\n",
             (lancheck) ? "\033[1;36mLAN" : "\033[1;32mWAN");
     return lancheck;
@@ -2797,9 +2722,8 @@ void parse_login(int fd)
 {
     struct mmo_account account;
     int result, j;
-    uint8_t *p = reinterpret_cast<uint8_t *>(&session[fd]->client_addr.sin_addr);
 
-    IP_String ip = ip2str(session[fd]->client_addr.sin_addr);
+    IP4Address ip = session[fd]->client_ip;
 
     if (session[fd]->eof)
     {
@@ -2861,7 +2785,7 @@ void parse_login(int fd)
                 LOGIN_LOG("Request for connection (non encryption mode) of %s (ip: %s).\n",
                     account.userid, ip);
 
-                if (!check_ip(session[fd]->client_addr.sin_addr))
+                if (!check_ip(ip))
                 {
                     LOGIN_LOG("Connection refused: IP isn't authorised (deny/allow, ip: %s).\n",
                          ip);
@@ -2934,15 +2858,15 @@ void parse_login(int fd)
                         {
                             if (server_fd[i] >= 0)
                             {
-                                if (lan_ip_check(p))
-                                    WFIFOL(fd, 47 + server_num * 32) = inet_addr(lan_char_ip.c_str());
+                                if (lan_ip_check(ip))
+                                    WFIFOIP(fd, 47 + server_num * 32) = lan_char_ip;
                                 else
-                                    WFIFOL(fd, 47 + server_num * 32) = server[i].ip;
+                                    WFIFOIP(fd, 47 + server_num * 32) = server[i].ip;
                                 WFIFOW(fd, 47 + server_num * 32 + 4) = server[i].port;
                                 WFIFO_STRING(fd, 47 + server_num * 32 + 6, server[i].name, 20);
                                 WFIFOW(fd, 47 + server_num * 32 + 26) = server[i].users;
-                                WFIFOW(fd, 47 + server_num * 32 + 28) = server[i].maintenance;
-                                WFIFOW(fd, 47 + server_num * 32 + 30) = server[i].is_new;
+                                WFIFOW(fd, 47 + server_num * 32 + 28) = 0; //maintenance;
+                                WFIFOW(fd, 47 + server_num * 32 + 30) = 0; //is_new;
                                 server_num++;
                             }
                         }
@@ -2969,7 +2893,7 @@ void parse_login(int fd)
                             auth_fifo[auth_fifo_pos].sex = account.sex;
                             auth_fifo[auth_fifo_pos].delflag = 0;
                             auth_fifo[auth_fifo_pos].ip =
-                                session[fd]->client_addr.sin_addr.s_addr;
+                                session[fd]->client_ip;
                             auth_fifo_pos++;
                             // if no char-server, don't send void list of servers, just disconnect the player with proper message
                         }
@@ -3021,10 +2945,8 @@ void parse_login(int fd)
                     account.passwd = stringish<AccountPass>(RFIFO_STRING<24>(fd, 26).to_print());
                     account.passwdenc = 0;
                     ServerName server_name = stringish<ServerName>(RFIFO_STRING<20>(fd, 60).to_print());
-                    LOGIN_LOG("Connection request of the char-server '%s' @ %d.%d.%d.%d:%d (ip: %s)\n",
-                         server_name, RFIFOB(fd, 54), RFIFOB(fd, 55),
-                         RFIFOB(fd, 56), RFIFOB(fd, 57), RFIFOW(fd, 58),
-                         ip);
+                    LOGIN_LOG("Connection request of the char-server '%s' @ %s:%d (ip: %s)\n",
+                            server_name, RFIFOIP(fd, 54), RFIFOW(fd, 58), ip);
                     result = mmo_auth(&account, fd);
 
                     if (result == -1 && account.sex == 2)
@@ -3059,12 +2981,12 @@ void parse_login(int fd)
                         PRINTF("Connection of the char-server '%s' accepted.\n",
                              server_name);
                         server[account.account_id] = mmo_char_server{};
-                        server[account.account_id].ip = RFIFOL(fd, 54);
+                        server[account.account_id].ip = RFIFOIP(fd, 54);
                         server[account.account_id].port = RFIFOW(fd, 58);
                         server[account.account_id].name = server_name;
                         server[account.account_id].users = 0;
-                        server[account.account_id].maintenance = RFIFOW(fd, 82);
-                        server[account.account_id].is_new = RFIFOW(fd, 84);
+                        //maintenance = RFIFOW(fd, 82);
+                        //is_new = RFIFOW(fd, 84);
                         server_fd[account.account_id] = fd;
                         if (anti_freeze_enable)
                             server_freezeflag[account.account_id] = 5;  // Char-server anti-freeze system. Counter. 5 ok, 4...0 freezed
@@ -3106,7 +3028,7 @@ void parse_login(int fd)
                 WFIFOW(fd, 0) = 0x7531;
             {
                 Version version = CURRENT_LOGIN_SERVER_VERSION;
-                version.flags = new_account_flag ? 1 : 0;
+                version.flags = new_account ? 1 : 0;
                 WFIFO_STRUCT(fd, 2, version);
                 WFIFOSET(fd, 10);
             }
@@ -3124,7 +3046,7 @@ void parse_login(int fd)
                     return;
                 WFIFOW(fd, 0) = 0x7919;
                 WFIFOB(fd, 2) = 1;
-                if (!check_ladminip(session[fd]->client_addr.sin_addr))
+                if (!check_ladminip(session[fd]->client_ip))
                 {
                     LOGIN_LOG("'ladmin'-login: Connection in administration mode refused: IP isn't authorised (ladmin_allow, ip: %s).\n",
                          ip);
@@ -3235,13 +3157,8 @@ int login_lan_config_read(ZString lancfgName)
     struct hostent *h = NULL;
 
     // set default configuration
-    lan_char_ip = stringish<IP_String>("127.0.0.1");
-    subneti[0] = 127;
-    subneti[1] = 0;
-    subneti[2] = 0;
-    subneti[3] = 1;
-    for (int j = 0; j < 4; j++)
-        subnetmaski[j] = 255;
+    lan_char_ip = IP4_LOCALHOST;
+    lan_subnet = IP4Mask(IP4_LOCALHOST, IP4_BROADCAST);
 
     std::ifstream in(lancfgName.c_str());
 
@@ -3268,55 +3185,30 @@ int login_lan_config_read(ZString lancfgName)
             h = gethostbyname(w2.c_str());
             if (h != NULL)
             {
-                SNPRINTF(lan_char_ip, 16, "%d.%d.%d.%d",
-                         static_cast<uint8_t>(h->h_addr[0]),
-                         static_cast<uint8_t>(h->h_addr[1]),
-                         static_cast<uint8_t>(h->h_addr[2]),
-                         static_cast<uint8_t>(h->h_addr[3]));
+                lan_char_ip = IP4Address({
+                        static_cast<uint8_t>(h->h_addr[0]),
+                        static_cast<uint8_t>(h->h_addr[1]),
+                        static_cast<uint8_t>(h->h_addr[2]),
+                        static_cast<uint8_t>(h->h_addr[3]),
+                });
             }
             else
             {
-                lan_char_ip = stringish<IP_String>(w2);
+                PRINTF("Bad IP value: %s\n", line);
+                abort();
             }
             PRINTF("LAN IP of char-server: %s.\n", lan_char_ip);
         }
-        else if (w1 == "subnet")
+        else if (w1 == "subnet" /*backward compatibility*/
+                || w1 == "lan_subnet")
         {
-            // Read Subnetwork
-            for (int j = 0; j < 4; j++)
-                subneti[j] = 0;
-            h = gethostbyname(w2.c_str());
-            if (h != NULL)
-            {
-                for (int j = 0; j < 4; j++)
-                    subneti[j] = h->h_addr[j];
-            }
-            else
+            if (!extract(w2, &lan_subnet))
             {
-                SSCANF(w2, "%hhu.%hhu.%hhu.%hhu", &subneti[0], &subneti[1],
-                        &subneti[2], &subneti[3]);
+                PRINTF("Bad IP mask: %s\n", line);
+                abort();
             }
-            PRINTF("Sub-network of the char-server: %d.%d.%d.%d.\n",
-                    subneti[0], subneti[1], subneti[2], subneti[3]);
-        }
-        else if (w1 == "subnetmask")
-        {                       // Read Subnetwork Mask
-            for (int j = 0; j < 4; j++)
-                subnetmaski[j] = 255;
-            h = gethostbyname(w2.c_str());
-            if (h != NULL)
-            {
-                for (int j = 0; j < 4; j++)
-                    subnetmaski[j] = h->h_addr[j];
-            }
-            else
-            {
-                SSCANF(w2, "%hhu.%hhu.%hhu.%hhu", &subnetmaski[0], &subnetmaski[1],
-                        &subnetmaski[2], &subnetmaski[3]);
-            }
-            PRINTF("Sub-network mask of the char-server: %d.%d.%d.%d.\n",
-                    subnetmaski[0], subnetmaski[1], subnetmaski[2],
-                    subnetmaski[3]);
+            PRINTF("Sub-network of the char-server: %s.\n",
+                    lan_subnet);
         }
         else
         {
@@ -3328,17 +3220,13 @@ int login_lan_config_read(ZString lancfgName)
     // log the LAN configuration
     LOGIN_LOG("The LAN configuration of the server is set:\n");
     LOGIN_LOG("- with LAN IP of char-server: %s.\n", lan_char_ip);
-    LOGIN_LOG("- with the sub-network of the char-server: %d.%d.%d.%d/%d.%d.%d.%d.\n",
-         subneti[0], subneti[1], subneti[2], subneti[3],
-         subnetmaski[0], subnetmaski[1], subnetmaski[2], subnetmaski[3]);
+    LOGIN_LOG("- with the sub-network of the char-server: %s.\n",
+            lan_subnet);
 
     // sub-network check of the char-server
     {
-        unsigned char p[4];
-        SSCANF(lan_char_ip, "%hhu.%hhu.%hhu.%hhu",
-                &p[0], &p[1], &p[2], &p[3]);
         PRINTF("LAN test of LAN IP of the char-server: ");
-        if (lan_ip_check(p) == 0)
+        if (!lan_ip_check(lan_char_ip))
         {
             PRINTF("\033[1;31m***ERROR: LAN IP of the char-server doesn't belong to the specified Sub-network\033[0m\n");
             LOGIN_LOG("***ERROR: LAN IP of the char-server doesn't belong to the specified Sub-network.\n");
@@ -3389,19 +3277,25 @@ int login_config_read(ZString cfgName)
             }
             else
             {
+                // a.b.c.d/0.0.0.0 (canonically, 0.0.0.0/0) covers all
                 if (w2 == "all")
                 {
                     // reset all previous values
                     access_ladmin.clear();
                     // set to all
-                    access_ladmin.push_back(AccessEntry());
+                    access_ladmin.push_back(IP4Mask());
                 }
                 else if (w2
-                         && !(access_ladmin.size() == 1
-                              && access_ladmin.front() == AccessEntry()))
+                        && !(access_ladmin.size() == 1
+                            && access_ladmin.front().mask() == IP4Address()))
                 {
                     // don't add IP if already 'all'
-                    AccessEntry n = stringish<AccessEntry>(w2);
+                    IP4Mask n;
+                    if (!extract(w2, &n))
+                    {
+                        PRINTF("Bad IP mask: %s\n", line);
+                        abort();
+                    }
                     access_ladmin.push_back(n);
                 }
             }
@@ -3416,7 +3310,7 @@ int login_config_read(ZString cfgName)
         }
         else if (w1 == "new_account")
         {
-            new_account_flag = config_switch(w2);
+            new_account = config_switch(w2);
         }
         else if (w1 == "login_port")
         {
@@ -3428,7 +3322,7 @@ int login_config_read(ZString cfgName)
         }
         else if (w1 == "gm_account_filename")
         {
-            GM_account_filename = w2;
+            gm_account_filename = w2;
         }
         else if (w1 == "gm_account_filename_check_timer")
         {
@@ -3481,7 +3375,7 @@ int login_config_read(ZString cfgName)
             else if (w2 == "allow,deny" || w2 == "allow, deny")
                 access_order = ACO::ALLOW_DENY;
             else if (w2 == "mutual-failture" || w2 == "mutual-failure")
-                access_order = ACO::MUTUAL_FAILTURE;
+                access_order = ACO::MUTUAL_FAILURE;
             else
                 PRINTF("Bad order: %s\n", w2);
         }
@@ -3498,14 +3392,19 @@ int login_config_read(ZString cfgName)
                     // reset all previous values
                     access_allow.clear();
                     // set to all
-                    access_allow.push_back(AccessEntry());
+                    access_allow.push_back(IP4Mask());
                 }
                 else if (w2
-                         && !(access_allow.size() == 1
-                              && access_allow.front() == AccessEntry()))
+                        && !(access_allow.size() == 1
+                            && access_allow.front().mask() == IP4Address()))
                 {
                     // don't add IP if already 'all'
-                    AccessEntry n = stringish<AccessEntry>(w2);
+                    IP4Mask n;
+                    if (!extract(w2, &n))
+                    {
+                        PRINTF("Bad IP mask: %s\n", line);
+                        abort();
+                    }
                     access_allow.push_back(n);
                 }
             }
@@ -3523,14 +3422,19 @@ int login_config_read(ZString cfgName)
                     // reset all previous values
                     access_deny.clear();
                     // set to all
-                    access_deny.push_back(AccessEntry());
+                    access_deny.push_back(IP4Mask());
                 }
                 else if (w2
-                         && !(access_deny.size() == 1
-                              && access_deny.front() == AccessEntry()))
+                        && !(access_deny.size() == 1
+                            && access_deny.front().mask() == IP4Address()))
                 {
                     // don't add IP if already 'all'
-                    AccessEntry n = stringish<AccessEntry>(w2);
+                    IP4Mask n;
+                    if (!extract(w2, &n))
+                    {
+                        PRINTF("Bad IP mask: %s\n", line);
+                        abort();
+                    }
                     access_deny.push_back(n);
                 }
             }
@@ -3541,7 +3445,7 @@ int login_config_read(ZString cfgName)
         }
         else if (w1 == "anti_freeze_interval")
         {
-            ANTI_FREEZE_INTERVAL = std::max(
+            anti_freeze_interval = std::max(
                     std::chrono::seconds(atoi(w2.c_str())),
                     std::chrono::seconds(5));
         }
@@ -3611,10 +3515,10 @@ void display_conf_warnings(void)
         level_new_gm = 60;
     }
 
-    if (new_account_flag != 0 && new_account_flag != 1)
+    if (new_account != 0 && new_account != 1)
     {
         PRINTF("***WARNING: Invalid value for new_account parameter -> set to 0 (no new account).\n");
-        new_account_flag = 0;
+        new_account = 0;
     }
 
     if (login_port < 1024 || login_port > 65535)
@@ -3701,7 +3605,7 @@ void display_conf_warnings(void)
 
     if (access_order == ACO::DENY_ALLOW)
     {
-        if (access_deny.size() == 1 && access_deny.front() == AccessEntry())
+        if (access_deny.size() == 1 && access_deny.front().mask() == IP4Address())
         {
             PRINTF("***WARNING: The IP security order is 'deny,allow' (allow if not deny).\n");
             PRINTF("            And you refuse ALL IP.\n");
@@ -3716,14 +3620,15 @@ void display_conf_warnings(void)
         }
     }
     else
-    {                           // ACO_MUTUAL_FAILTURE
+    {
+        // ACO::MUTUAL_FAILURE
         if (access_allow.empty())
         {
             PRINTF("***WARNING: The IP security order is 'mutual-failture'\n");
             PRINTF("            (allow if in the allow list and not in the deny list).\n");
             PRINTF("            But, NO IP IS AUTHORISED!\n");
         }
-        else if (access_deny.size() == 1 && access_deny.front() == AccessEntry())
+        else if (access_deny.size() == 1 && access_deny.front().mask() == IP4Address())
         {
             PRINTF("***WARNING: The IP security order is mutual-failture\n");
             PRINTF("            (allow if in the allow list and not in the deny list).\n");
@@ -3755,14 +3660,14 @@ void save_config_in_log(void)
         LOGIN_LOG("- with a remote administration with the password of %zu character(s).\n",
                 admin_pass.size());
     if (access_ladmin.empty()
-        || (access_ladmin.size() == 1 && access_ladmin.front() == AccessEntry()))
+        || (access_ladmin.size() == 1 && access_ladmin.front().mask() == IP4Address()))
     {
         LOGIN_LOG("- to accept any IP for remote administration\n");
     }
     else
     {
         LOGIN_LOG("- to accept following IP for remote administration:\n");
-        for (const AccessEntry& ae : access_ladmin)
+        for (const IP4Mask& ae : access_ladmin)
             LOGIN_LOG("  %s\n", ae);
     }
 
@@ -3779,7 +3684,7 @@ void save_config_in_log(void)
         LOGIN_LOG("- to create GM with level '%d' when @gm is used.\n",
                    level_new_gm);
 
-    if (new_account_flag == 1)
+    if (new_account == 1)
         LOGIN_LOG("- to ALLOW new users (with _F/_M).\n");
     else
         LOGIN_LOG("- to NOT ALLOW new users (with _F/_M).\n");
@@ -3787,7 +3692,7 @@ void save_config_in_log(void)
     LOGIN_LOG("- with the accounts file name: '%s'.\n",
                account_filename);
     LOGIN_LOG("- with the GM accounts file name: '%s'.\n",
-               GM_account_filename);
+               gm_account_filename);
     if (gm_account_filename_check_timer == interval_t::zero())
         LOGIN_LOG("- to NOT check GM accounts file modifications.\n");
     else
@@ -3847,14 +3752,14 @@ void save_config_in_log(void)
         {
             LOGIN_LOG("- with the IP security order: 'deny,allow' (allow if not deny). You refuse no IP.\n");
         }
-        else if (access_deny.size() == 1 && access_deny.front() == AccessEntry())
+        else if (access_deny.size() == 1 && access_deny.front().mask() == IP4Address())
         {
             LOGIN_LOG("- with the IP security order: 'deny,allow' (allow if not deny). You refuse ALL IP.\n");
         }
         else
         {
             LOGIN_LOG("- with the IP security order: 'deny,allow' (allow if not deny). Refused IP are:\n");
-            for (const AccessEntry& ae : access_deny)
+            for (IP4Mask ae : access_deny)
                 LOGIN_LOG("  %s\n", ae);
         }
     }
@@ -3864,14 +3769,14 @@ void save_config_in_log(void)
         {
             LOGIN_LOG("- with the IP security order: 'allow,deny' (deny if not allow). But, NO IP IS AUTHORISED!\n");
         }
-        else if (access_allow.size() == 1 && access_allow.front() == AccessEntry())
+        else if (access_allow.size() == 1 && access_allow.front().mask() == IP4Address())
         {
             LOGIN_LOG("- with the IP security order: 'allow,deny' (deny if not allow). You authorise ALL IP.\n");
         }
         else
         {
             LOGIN_LOG("- with the IP security order: 'allow,deny' (deny if not allow). Authorised IP are:\n");
-            for (const AccessEntry& ae : access_allow)
+            for (IP4Mask ae : access_allow)
                 LOGIN_LOG("  %s\n", ae);
         }
     }
@@ -3882,24 +3787,24 @@ void save_config_in_log(void)
         {
             LOGIN_LOG("  But, NO IP IS AUTHORISED!\n");
         }
-        else if (access_deny.size() == 1 && access_deny.front() == AccessEntry())
+        else if (access_deny.size() == 1 && access_deny.front().mask() == IP4Address())
         {
             LOGIN_LOG("  But, you refuse ALL IP!\n");
         }
         else
         {
-            if (access_allow.size() == 1 && access_allow.front() == AccessEntry())
+            if (access_allow.size() == 1 && access_allow.front().mask() == IP4Address())
             {
                 LOGIN_LOG("  You authorise ALL IP.\n");
             }
             else
             {
                 LOGIN_LOG("  Authorised IP are:\n");
-                for (const AccessEntry& ae : access_allow)
+                for (IP4Mask ae : access_allow)
                     LOGIN_LOG("    %s\n", ae);
             }
             LOGIN_LOG("  Refused IP are:\n");
-            for (const AccessEntry& ae : access_deny)
+            for (IP4Mask ae : access_deny)
                 LOGIN_LOG("    %s\n", ae);
         }
     }
@@ -3964,7 +3869,7 @@ int do_init(int argc, ZString *argv)
     {
         Timer(gettick() + std::chrono::seconds(1),
                 char_anti_freeze_system,
-                ANTI_FREEZE_INTERVAL
+                anti_freeze_interval
         ).detach();
     }
 
diff --git a/src/map/atcommand.cpp b/src/map/atcommand.cpp
index 4b52d93..4b41c7b 100644
--- a/src/map/atcommand.cpp
+++ b/src/map/atcommand.cpp
@@ -418,14 +418,14 @@ void log_atcommand(dumb_ptr<map_session_data> sd, ZString cmd)
             cmd);
 }
 
-FString gm_logfile_name;
+FString gm_log;
 /*==========================================
  * Log a timestamped line to GM log file
  *------------------------------------------
  */
 FILE *get_gm_log()
 {
-    if (!gm_logfile_name)
+    if (!gm_log)
         return NULL;
 
     struct tm ctime = TimeT::now();
@@ -441,7 +441,7 @@ FILE *get_gm_log()
     last_logfile_nr = logfile_nr;
 
     FString fullname = STRPRINTF("%s.%04d-%02d",
-            gm_logfile_name, year, month);
+            gm_log, year, month);
 
     if (gm_logfile)
         fclose(gm_logfile);
@@ -451,7 +451,7 @@ FILE *get_gm_log()
     if (!gm_logfile)
     {
         perror("GM log file");
-        gm_logfile_name = FString();
+        gm_log = FString();
     }
     return gm_logfile;
 }
@@ -511,7 +511,7 @@ AtCommandInfo *atcommand(const int level, ZString message)
 {
     ZString p = message;
 
-    if (battle_config.atc_gmonly != 0 && !level)    // level = pc_isGM(sd)
+    if (battle_config.atcommand_gm_only != 0 && !level)    // level = pc_isGM(sd)
         return nullptr;
     if (!p)
     {
@@ -1466,8 +1466,8 @@ int atcommand_alive(const int fd, dumb_ptr<map_session_data> sd,
     sd->status.hp = sd->status.max_hp;
     sd->status.sp = sd->status.max_sp;
     pc_setstand(sd);
-    if (static_cast<interval_t>(battle_config.pc_invincible_time) > interval_t::zero())
-        pc_setinvincibletimer(sd, static_cast<interval_t>(battle_config.pc_invincible_time));
+    if (static_cast<interval_t>(battle_config.player_invincible_time) > interval_t::zero())
+        pc_setinvincibletimer(sd, static_cast<interval_t>(battle_config.player_invincible_time));
     clif_updatestatus(sd, SP::HP);
     clif_updatestatus(sd, SP::SP);
     clif_resurrection(sd, 1);
@@ -2081,9 +2081,9 @@ int atcommand_spawn(const int fd, dumb_ptr<map_session_data> sd,
         number = 1;
 
     // If value of atcommand_spawn_quantity_limit directive is greater than or equal to 1 and quantity of monsters is greater than value of the directive
-    if (battle_config.atc_spawn_quantity_limit >= 1
-        && number > battle_config.atc_spawn_quantity_limit)
-        number = battle_config.atc_spawn_quantity_limit;
+    if (battle_config.atcommand_spawn_quantity_limit >= 1
+        && number > battle_config.atcommand_spawn_quantity_limit)
+        number = battle_config.atcommand_spawn_quantity_limit;
 
     if (battle_config.etc_log)
         PRINTF("@spawn monster='%s' id=%d count=%d (%d,%d)\n",
@@ -2546,8 +2546,8 @@ int atcommand_revive(const int fd, dumb_ptr<map_session_data> sd,
     {
         pl_sd->status.hp = pl_sd->status.max_hp;
         pc_setstand(pl_sd);
-        if (static_cast<interval_t>(battle_config.pc_invincible_time) > interval_t::zero())
-            pc_setinvincibletimer(sd, static_cast<interval_t>(battle_config.pc_invincible_time));
+        if (static_cast<interval_t>(battle_config.player_invincible_time) > interval_t::zero())
+            pc_setinvincibletimer(sd, static_cast<interval_t>(battle_config.player_invincible_time));
         clif_updatestatus(pl_sd, SP::HP);
         clif_updatestatus(pl_sd, SP::SP);
         clif_resurrection(pl_sd, 1);
@@ -5917,10 +5917,7 @@ int atcommand_skill_learn(const int fd, dumb_ptr<map_session_data>,
 int atcommand_ipcheck(const int fd, dumb_ptr<map_session_data>,
         ZString message)
 {
-    struct sockaddr_in sai;
     CharName character;
-    socklen_t sa_len = sizeof(struct sockaddr);
-    unsigned long ip;
 
     if (!asplit(message, &character))
     {
@@ -5935,14 +5932,7 @@ int atcommand_ipcheck(const int fd, dumb_ptr<map_session_data>,
         return -1;
     }
 
-    if (getpeername(pl_sd->fd, reinterpret_cast<struct sockaddr *>(&sai), &sa_len))
-    {
-        clif_displaymessage(fd,
-                "Guru Meditation Error: getpeername() failed");
-        return -1;
-    }
-
-    ip = sai.sin_addr.s_addr;
+    IP4Address ip = pl_sd->get_ip();
 
     // We now have the IP address of a character.
     // Loop over all logged in sessions looking for matches.
@@ -5954,11 +5944,8 @@ int atcommand_ipcheck(const int fd, dumb_ptr<map_session_data>,
         pl_sd = dumb_ptr<map_session_data>(static_cast<map_session_data *>(session[i]->session_data.get()));
         if (pl_sd && pl_sd->state.auth)
         {
-            if (getpeername(pl_sd->fd, reinterpret_cast<struct sockaddr *>(&sai), &sa_len))
-                continue;
-
             // Is checking GM levels really needed here?
-            if (ip == sai.sin_addr.s_addr)
+            if (ip == pl_sd->get_ip())
             {
                 FString output = STRPRINTF(
                         "Name: %s | Location: %s %d %d",
diff --git a/src/map/atcommand.hpp b/src/map/atcommand.hpp
index e07a264..280372e 100644
--- a/src/map/atcommand.hpp
+++ b/src/map/atcommand.hpp
@@ -13,6 +13,6 @@ int atcommand_config_read(ZString cfgName);
 void log_atcommand(dumb_ptr<map_session_data> sd, ZString cmd);
 
 // only used by map.cpp
-extern FString gm_logfile_name;
+extern FString gm_log;
 
 #endif // ATCOMMAND_HPP
diff --git a/src/map/battle.cpp b/src/map/battle.cpp
index 4045348..02ea370 100644
--- a/src/map/battle.cpp
+++ b/src/map/battle.cpp
@@ -2302,18 +2302,12 @@ int battle_config_read(ZString cfgName)
         battle_config.enemy_critical_rate = 100;
         battle_config.enemy_str = 1;
         battle_config.enemy_perfect_flee = 0;
-        battle_config.cast_rate = 100;
+        battle_config.casting_rate = 100;
         battle_config.delay_rate = 100;
         battle_config.delay_dependon_dex = 0;
-        battle_config.sdelay_attack_enable = 0;
-        battle_config.left_cardfix_to_right = 0;
-        battle_config.pc_skill_add_range = 0;
-        battle_config.skill_out_range_consume = 1;
-        battle_config.mob_skill_add_range = 0;
-        battle_config.pc_damage_delay = 1;
-        battle_config.defnotenemy = 1;
-        battle_config.random_monster_checklv = 1;
-        battle_config.attr_recover = 1;
+        battle_config.skill_delay_attack_enable = 0;
+        battle_config.monster_skill_add_range = 0;
+        battle_config.player_damage_delay = 1;
         battle_config.flooritem_lifetime = std::chrono::duration_cast<std::chrono::milliseconds>(LIFETIME_FLOORITEM).count();
         battle_config.item_auto_get = 0;
         battle_config.drop_pickup_safety_zone = 20;
@@ -2323,43 +2317,26 @@ int battle_config_read(ZString cfgName)
 
         battle_config.base_exp_rate = 100;
         battle_config.job_exp_rate = 100;
-        battle_config.gtb_pvp_only = 0;
         battle_config.death_penalty_type = 0;
         battle_config.death_penalty_base = 0;
         battle_config.death_penalty_job = 0;
-        battle_config.zeny_penalty = 0;
         battle_config.restart_hp_rate = 0;
         battle_config.restart_sp_rate = 0;
         battle_config.monster_hp_rate = 100;
         battle_config.monster_max_aspd = 199;
-        battle_config.atc_gmonly = 0;
-        battle_config.gm_allskill = 0;
-        battle_config.gm_allequip = 0;
-        battle_config.gm_skilluncond = 0;
-        battle_config.skillfree = 0;
-        battle_config.skillup_limit = 0;
-        battle_config.wp_rate = 100;
-        battle_config.pp_rate = 100;
+        battle_config.atcommand_gm_only = 0;
+        battle_config.gm_all_equipment = 0;
         battle_config.monster_active_enable = 1;
         battle_config.mob_skill_use = 1;
         battle_config.mob_count_rate = 100;
-        battle_config.quest_skill_learn = 0;
-        battle_config.quest_skill_reset = 1;
         battle_config.basic_skill_check = 1;
-        battle_config.pc_invincible_time = 5000;
+        battle_config.player_invincible_time = 5000;
         battle_config.skill_min_damage = 0;
-        battle_config.finger_offensive_type = 0;
-        battle_config.heal_exp = 0;
-        battle_config.resurrection_exp = 0;
-        battle_config.shop_exp = 0;
-        battle_config.combo_delay_rate = 100;
-        battle_config.wedding_modifydisplay = 0;
         battle_config.natural_healhp_interval = 6000;
         battle_config.natural_healsp_interval = 8000;
         battle_config.natural_heal_skill_interval = 10000;
         battle_config.natural_heal_weight_rate = 50;
         battle_config.itemheal_regeneration_factor = 1;
-        battle_config.item_name_override_grffile = 1;
         battle_config.arrow_decrement = 1;
         battle_config.max_aspd = 199;
         battle_config.max_hp = 32500;
@@ -2367,16 +2344,13 @@ int battle_config_read(ZString cfgName)
         battle_config.max_lv = 99;  // [MouseJstr]
         battle_config.max_parameter = 99;
         battle_config.max_cart_weight = 8000;
-        battle_config.pc_skill_log = 0;
-        battle_config.mob_skill_log = 0;
+        battle_config.monster_skill_log = 0;
         battle_config.battle_log = 0;
         battle_config.save_log = 0;
         battle_config.error_log = 1;
         battle_config.etc_log = 1;
         battle_config.save_clothcolor = 0;
         battle_config.undead_detect_type = 0;
-        battle_config.pc_auto_counter_type = 1;
-        battle_config.monster_auto_counter_type = 1;
         battle_config.agi_penaly_type = 0;
         battle_config.agi_penaly_count = 3;
         battle_config.agi_penaly_num = 0;
@@ -2385,53 +2359,22 @@ int battle_config_read(ZString cfgName)
         battle_config.vit_penaly_count = 3;
         battle_config.vit_penaly_num = 0;
         battle_config.vit_penaly_count_lv = static_cast<int>(ATK::DEF); // FIXME
-        battle_config.pc_skill_reiteration = 0;
-        battle_config.monster_skill_reiteration = 0;
-        battle_config.pc_skill_nofootset = 0;
-        battle_config.monster_skill_nofootset = 0;
-        battle_config.pc_cloak_check_type = 0;
-        battle_config.monster_cloak_check_type = 0;
         battle_config.mob_changetarget_byskill = 0;
-        battle_config.pc_attack_direction_change = 1;
+        battle_config.player_attack_direction_change = 1;
         battle_config.monster_attack_direction_change = 1;
-        battle_config.pc_undead_nofreeze = 0;
-        battle_config.pc_land_skill_limit = 1;
-        battle_config.monster_land_skill_limit = 1;
-        battle_config.party_skill_penaly = 1;
-        battle_config.monster_class_change_full_recover = 0;
-        battle_config.produce_item_name_input = 1;
-        battle_config.produce_potion_name_input = 1;
-        battle_config.making_arrow_name_input = 1;
-        battle_config.holywater_name_input = 1;
         battle_config.display_delay_skill_fail = 1;
-        battle_config.chat_warpportal = 0;
-        battle_config.mob_warpportal = 0;
         battle_config.dead_branch_active = 0;
         battle_config.show_steal_in_same_party = 0;
-        battle_config.enable_upper_class = 0;
-        battle_config.pc_attack_attr_none = 0;
-        battle_config.mob_attack_attr_none = 1;
-        battle_config.mob_ghostring_fix = 0;
-        battle_config.gx_allhit = 0;
-        battle_config.gx_cardfix = 0;
-        battle_config.gx_dupele = 1;
-        battle_config.gx_disptype = 1;
-        battle_config.player_skill_partner_check = 1;
         battle_config.hide_GM_session = 0;
-        battle_config.unit_movement_type = 0;
         battle_config.invite_request_check = 1;
-        battle_config.skill_removetrap_type = 0;
         battle_config.disp_experience = 0;
         battle_config.prevent_logout = 1;   // Added by RoVeRT
         battle_config.maximum_level = 255;  // Added by Valaris
         battle_config.drops_by_luk = 0; // [Valaris]
         battle_config.pk_mode = 0;  // [Valaris]
         battle_config.multi_level_up = 0;   // [Valaris]
-        battle_config.backstab_bow_penalty = 0; // Akaru
-        battle_config.show_mob_hp = 0;  // [Valaris]
         battle_config.hack_info_GM_level = 60;  // added by [Yor] (default: 60, GM level)
         battle_config.any_warp_GM_min_level = 20;   // added by [Yor]
-        battle_config.packet_ver_flag = 63; // added by [Yor]
         battle_config.min_hair_style = 0;
         battle_config.max_hair_style = 20;
         battle_config.min_hair_color = 0;
@@ -2469,9 +2412,7 @@ int battle_config_read(ZString cfgName)
     FString line;
     while (io::getline(in, line))
     {
-#define BATTLE_CONFIG_VAR2(name, varname) {{name}, &battle_config.varname}
-#define BATTLE_CONFIG_VAR(name) BATTLE_CONFIG_VAR2(#name, name)
-        // s/{"\([a-zA-Z_0-9]*\)", &battle_config.\1}/BATTLE_CONFIG_VAR(\1)/
+#define BATTLE_CONFIG_VAR(name) {{#name}, &battle_config.name}
         const struct
         {
             ZString str;
@@ -2483,18 +2424,12 @@ int battle_config_read(ZString cfgName)
             BATTLE_CONFIG_VAR(enemy_critical_rate),
             BATTLE_CONFIG_VAR(enemy_str),
             BATTLE_CONFIG_VAR(enemy_perfect_flee),
-            BATTLE_CONFIG_VAR2("casting_rate", cast_rate),
+            BATTLE_CONFIG_VAR(casting_rate),
             BATTLE_CONFIG_VAR(delay_rate),
             BATTLE_CONFIG_VAR(delay_dependon_dex),
-            BATTLE_CONFIG_VAR2("skill_delay_attack_enable", sdelay_attack_enable),
-            BATTLE_CONFIG_VAR(left_cardfix_to_right),
-            BATTLE_CONFIG_VAR2("player_skill_add_range", pc_skill_add_range),
-            BATTLE_CONFIG_VAR(skill_out_range_consume),
-            BATTLE_CONFIG_VAR2("monster_skill_add_range", mob_skill_add_range),
-            BATTLE_CONFIG_VAR2("player_damage_delay", pc_damage_delay),
-            BATTLE_CONFIG_VAR2("defunit_not_enemy", defnotenemy),
-            BATTLE_CONFIG_VAR(random_monster_checklv),
-            BATTLE_CONFIG_VAR2("attribute_recover", attr_recover),
+            BATTLE_CONFIG_VAR(skill_delay_attack_enable),
+            BATTLE_CONFIG_VAR(monster_skill_add_range),
+            BATTLE_CONFIG_VAR(player_damage_delay),
             BATTLE_CONFIG_VAR(flooritem_lifetime),
             BATTLE_CONFIG_VAR(item_auto_get),
             BATTLE_CONFIG_VAR(drop_pickup_safety_zone),
@@ -2503,45 +2438,27 @@ int battle_config_read(ZString cfgName)
             BATTLE_CONFIG_VAR(item_third_get_time),
             BATTLE_CONFIG_VAR(base_exp_rate),
             BATTLE_CONFIG_VAR(job_exp_rate),
-            BATTLE_CONFIG_VAR(gtb_pvp_only),
             BATTLE_CONFIG_VAR(death_penalty_type),
             BATTLE_CONFIG_VAR(death_penalty_base),
             BATTLE_CONFIG_VAR(death_penalty_job),
-            BATTLE_CONFIG_VAR(zeny_penalty),
             BATTLE_CONFIG_VAR(restart_hp_rate),
             BATTLE_CONFIG_VAR(restart_sp_rate),
             BATTLE_CONFIG_VAR(monster_hp_rate),
             BATTLE_CONFIG_VAR(monster_max_aspd),
-            BATTLE_CONFIG_VAR2("atcommand_gm_only", atc_gmonly),
-            BATTLE_CONFIG_VAR2("atcommand_spawn_quantity_limit", atc_spawn_quantity_limit),
-            BATTLE_CONFIG_VAR2("gm_all_skill", gm_allskill),
-            BATTLE_CONFIG_VAR2("gm_all_skill_add_abra", gm_allskill_addabra),
-            BATTLE_CONFIG_VAR2("gm_all_equipment", gm_allequip),
-            BATTLE_CONFIG_VAR2("gm_skill_unconditional", gm_skilluncond),
-            BATTLE_CONFIG_VAR2("player_skillfree", skillfree),
-            BATTLE_CONFIG_VAR2("player_skillup_limit", skillup_limit),
-            BATTLE_CONFIG_VAR2("weapon_produce_rate", wp_rate),
-            BATTLE_CONFIG_VAR2("potion_produce_rate", pp_rate),
+            BATTLE_CONFIG_VAR(atcommand_gm_only),
+            BATTLE_CONFIG_VAR(atcommand_spawn_quantity_limit),
+            BATTLE_CONFIG_VAR(gm_all_equipment),
             BATTLE_CONFIG_VAR(monster_active_enable),
             BATTLE_CONFIG_VAR(mob_skill_use),
             BATTLE_CONFIG_VAR(mob_count_rate),
-            BATTLE_CONFIG_VAR(quest_skill_learn),
-            BATTLE_CONFIG_VAR(quest_skill_reset),
             BATTLE_CONFIG_VAR(basic_skill_check),
-            BATTLE_CONFIG_VAR2("player_invincible_time", pc_invincible_time),
+            BATTLE_CONFIG_VAR(player_invincible_time),
             BATTLE_CONFIG_VAR(skill_min_damage),
-            BATTLE_CONFIG_VAR(finger_offensive_type),
-            BATTLE_CONFIG_VAR(heal_exp),
-            BATTLE_CONFIG_VAR(resurrection_exp),
-            BATTLE_CONFIG_VAR(shop_exp),
-            BATTLE_CONFIG_VAR(combo_delay_rate),
-            BATTLE_CONFIG_VAR(wedding_modifydisplay),
             BATTLE_CONFIG_VAR(natural_healhp_interval),
             BATTLE_CONFIG_VAR(natural_healsp_interval),
             BATTLE_CONFIG_VAR(natural_heal_skill_interval),
             BATTLE_CONFIG_VAR(natural_heal_weight_rate),
             BATTLE_CONFIG_VAR(itemheal_regeneration_factor),
-            BATTLE_CONFIG_VAR(item_name_override_grffile),
             BATTLE_CONFIG_VAR(arrow_decrement),
             BATTLE_CONFIG_VAR(max_aspd),
             BATTLE_CONFIG_VAR(max_hp),
@@ -2549,16 +2466,13 @@ int battle_config_read(ZString cfgName)
             BATTLE_CONFIG_VAR(max_lv),
             BATTLE_CONFIG_VAR(max_parameter),
             BATTLE_CONFIG_VAR(max_cart_weight),
-            BATTLE_CONFIG_VAR2("player_skill_log", pc_skill_log),
-            BATTLE_CONFIG_VAR2("monster_skill_log", mob_skill_log),
+            BATTLE_CONFIG_VAR(monster_skill_log),
             BATTLE_CONFIG_VAR(battle_log),
             BATTLE_CONFIG_VAR(save_log),
             BATTLE_CONFIG_VAR(error_log),
             BATTLE_CONFIG_VAR(etc_log),
             BATTLE_CONFIG_VAR(save_clothcolor),
             BATTLE_CONFIG_VAR(undead_detect_type),
-            BATTLE_CONFIG_VAR2("player_auto_counter_type", pc_auto_counter_type),
-            BATTLE_CONFIG_VAR(monster_auto_counter_type),
             BATTLE_CONFIG_VAR(agi_penaly_type),
             BATTLE_CONFIG_VAR(agi_penaly_count),
             BATTLE_CONFIG_VAR(agi_penaly_num),
@@ -2567,43 +2481,15 @@ int battle_config_read(ZString cfgName)
             BATTLE_CONFIG_VAR(vit_penaly_count),
             BATTLE_CONFIG_VAR(vit_penaly_num),
             BATTLE_CONFIG_VAR(vit_penaly_count_lv),
-            BATTLE_CONFIG_VAR2("player_skill_reiteration", pc_skill_reiteration),
-            BATTLE_CONFIG_VAR(monster_skill_reiteration),
-            BATTLE_CONFIG_VAR2("player_skill_nofootset", pc_skill_nofootset),
-            BATTLE_CONFIG_VAR(monster_skill_nofootset),
-            BATTLE_CONFIG_VAR2("player_cloak_check_type", pc_cloak_check_type),
-            BATTLE_CONFIG_VAR(monster_cloak_check_type),
             BATTLE_CONFIG_VAR(mob_changetarget_byskill),
-            BATTLE_CONFIG_VAR2("player_attack_direction_change", pc_attack_direction_change),
+            BATTLE_CONFIG_VAR(player_attack_direction_change),
             BATTLE_CONFIG_VAR(monster_attack_direction_change),
-            BATTLE_CONFIG_VAR2("player_land_skill_limit", pc_land_skill_limit),
-            BATTLE_CONFIG_VAR(monster_land_skill_limit),
-            BATTLE_CONFIG_VAR(party_skill_penaly),
-            BATTLE_CONFIG_VAR(monster_class_change_full_recover),
-            BATTLE_CONFIG_VAR(produce_item_name_input),
-            BATTLE_CONFIG_VAR(produce_potion_name_input),
-            BATTLE_CONFIG_VAR(making_arrow_name_input),
-            BATTLE_CONFIG_VAR(holywater_name_input),
             BATTLE_CONFIG_VAR(display_delay_skill_fail),
-            BATTLE_CONFIG_VAR(chat_warpportal),
-            BATTLE_CONFIG_VAR(mob_warpportal),
             BATTLE_CONFIG_VAR(dead_branch_active),
             BATTLE_CONFIG_VAR(show_steal_in_same_party),
-            BATTLE_CONFIG_VAR(enable_upper_class),
-            BATTLE_CONFIG_VAR(mob_attack_attr_none),
-            BATTLE_CONFIG_VAR(mob_ghostring_fix),
-            BATTLE_CONFIG_VAR(pc_attack_attr_none),
-            BATTLE_CONFIG_VAR(gx_allhit),
-            BATTLE_CONFIG_VAR(gx_cardfix),
-            BATTLE_CONFIG_VAR(gx_dupele),
-            BATTLE_CONFIG_VAR(gx_disptype),
-            BATTLE_CONFIG_VAR(player_skill_partner_check),
             BATTLE_CONFIG_VAR(hide_GM_session),
-            BATTLE_CONFIG_VAR(unit_movement_type),
             BATTLE_CONFIG_VAR(invite_request_check),
-            BATTLE_CONFIG_VAR(skill_removetrap_type),
             BATTLE_CONFIG_VAR(disp_experience),
-            BATTLE_CONFIG_VAR(riding_weight),
             BATTLE_CONFIG_VAR(prevent_logout),   // Added by RoVeRT
             BATTLE_CONFIG_VAR(alchemist_summon_reward), // [Valaris]
             BATTLE_CONFIG_VAR(maximum_level), // [Valaris]
@@ -2611,11 +2497,8 @@ int battle_config_read(ZString cfgName)
             BATTLE_CONFIG_VAR(monsters_ignore_gm),   // [Valaris]
             BATTLE_CONFIG_VAR(pk_mode), // [Valaris]
             BATTLE_CONFIG_VAR(multi_level_up),   // [Valaris]
-            BATTLE_CONFIG_VAR(backstab_bow_penalty),
-            BATTLE_CONFIG_VAR(show_mob_hp), // [Valaris]
             BATTLE_CONFIG_VAR(hack_info_GM_level),   // added by [Yor]
             BATTLE_CONFIG_VAR(any_warp_GM_min_level), // added by [Yor]
-            BATTLE_CONFIG_VAR(packet_ver_flag), // added by [Yor]
             BATTLE_CONFIG_VAR(min_hair_style),   // added by [MouseJstr]
             BATTLE_CONFIG_VAR(max_hair_style),   // added by [MouseJstr]
             BATTLE_CONFIG_VAR(min_hair_color),   // added by [MouseJstr]
@@ -2771,11 +2654,6 @@ int battle_config_read(ZString cfgName)
             battle_config.mask_ip_gms = 0;
         else if (battle_config.mask_ip_gms > 1)
             battle_config.mask_ip_gms = 1;
-
-        // at least 1 client must be accepted
-        if ((battle_config.packet_ver_flag & 63) == 0)  // added by [Yor]
-            battle_config.packet_ver_flag = 63; // accept all clients
-
     }
 
     return 0;
diff --git a/src/map/battle.hpp b/src/map/battle.hpp
index 6ed32fd..c933e28 100644
--- a/src/map/battle.hpp
+++ b/src/map/battle.hpp
@@ -96,16 +96,10 @@ extern struct Battle_Config
     int enemy_critical_rate;
     int enemy_str;
     int enemy_perfect_flee;
-    int cast_rate, delay_rate, delay_dependon_dex;
-    int sdelay_attack_enable;
-    int left_cardfix_to_right;
-    int pc_skill_add_range;
-    int skill_out_range_consume;
-    int mob_skill_add_range;
-    int pc_damage_delay;
-    int defnotenemy;
-    int random_monster_checklv;
-    int attr_recover;
+    int casting_rate, delay_rate, delay_dependon_dex;
+    int skill_delay_attack_enable;
+    int monster_skill_add_range;
+    int player_damage_delay;
     int flooritem_lifetime;
     int item_auto_get;
     int item_first_get_time;
@@ -114,41 +108,23 @@ extern struct Battle_Config
     int base_exp_rate, job_exp_rate;
     int death_penalty_type;
     int death_penalty_base, death_penalty_job;
-    int gtb_pvp_only;          // [MouseJstr]
-    int zeny_penalty;
     int restart_hp_rate;
     int restart_sp_rate;
     int monster_hp_rate;
     int monster_max_aspd;
-    int atc_gmonly;
-    int atc_spawn_quantity_limit;
-    int gm_allskill;
-    int gm_allskill_addabra;
-    int gm_allequip;
-    int gm_skilluncond;
-    int skillfree;
-    int skillup_limit;
-    int wp_rate;
-    int pp_rate;
+    int atcommand_gm_only;
+    int atcommand_spawn_quantity_limit;
+    int gm_all_equipment;
     int monster_active_enable;
     int mob_skill_use;
     int mob_count_rate;
-    int quest_skill_learn;
-    int quest_skill_reset;
     int basic_skill_check;
-    int pc_invincible_time;
+    int player_invincible_time;
     int skill_min_damage;
-    int finger_offensive_type;
-    int heal_exp;
-    int resurrection_exp;
-    int shop_exp;
-    int combo_delay_rate;
-    int wedding_modifydisplay;
     int natural_healhp_interval;
     int natural_healsp_interval;
     int natural_heal_skill_interval;
     int natural_heal_weight_rate;
-    int item_name_override_grffile;
     int arrow_decrement;
     int max_aspd;
     int max_hp;
@@ -156,89 +132,54 @@ extern struct Battle_Config
     int max_lv;
     int max_parameter;
     int max_cart_weight;
-    int pc_skill_log;
-    int mob_skill_log;
+    int monster_skill_log;
     int battle_log;
     int save_log;
     int error_log;
     int etc_log;
     int save_clothcolor;
     int undead_detect_type;
-    int pc_auto_counter_type;
-    int monster_auto_counter_type;
     int agi_penaly_type;
     int agi_penaly_count;
     int agi_penaly_num;
     int vit_penaly_type;
     int vit_penaly_count;
     int vit_penaly_num;
-    int pc_skill_reiteration;
-    int monster_skill_reiteration;
-    int pc_skill_nofootset;
-    int monster_skill_nofootset;
-    int pc_cloak_check_type;
-    int monster_cloak_check_type;
     int mob_changetarget_byskill;
-    int pc_attack_direction_change;
+    int player_attack_direction_change;
     int monster_attack_direction_change;
-    int pc_undead_nofreeze;
-    int pc_land_skill_limit;
-    int monster_land_skill_limit;
-    int party_skill_penaly;
-    int monster_class_change_full_recover;
-    int produce_item_name_input;
-    int produce_potion_name_input;
-    int making_arrow_name_input;
-    int holywater_name_input;
     int display_delay_skill_fail;
-    int chat_warpportal;
-    int mob_warpportal;
     int dead_branch_active;
     int show_steal_in_same_party;
-    int enable_upper_class;
-    int mob_attack_attr_none;
-    int mob_ghostring_fix;
-    int pc_attack_attr_none;
 
-    int prevent_logout;        // Added by RoVeRT
+    int prevent_logout;
 
-    int alchemist_summon_reward;   // [Valaris]
+    int alchemist_summon_reward;
     int maximum_level;
     int drops_by_luk;
     int monsters_ignore_gm;
     int multi_level_up;
     int pk_mode;
-    int show_mob_hp;           // end additions [Valaris]
 
     int agi_penaly_count_lv;
     int vit_penaly_count_lv;
 
-    int gx_allhit;
-    int gx_cardfix;
-    int gx_dupele;
-    int gx_disptype;
-    int player_skill_partner_check;
     int hide_GM_session;
-    int unit_movement_type;
     int invite_request_check;
-    int skill_removetrap_type;
     int disp_experience;
-    int riding_weight;
-    int backstab_bow_penalty;
 
-    int hack_info_GM_level;    // added by [Yor]
-    int any_warp_GM_min_level; // added by [Yor]
-    int packet_ver_flag;       // added by [Yor]
+    int hack_info_GM_level;
+    int any_warp_GM_min_level;
 
-    int min_hair_style;        // added by [MouseJstr]
-    int max_hair_style;        // added by [MouseJstr]
-    int min_hair_color;        // added by [MouseJstr]
-    int max_hair_color;        // added by [MouseJstr]
-    int min_cloth_color;       // added by [MouseJstr]
-    int max_cloth_color;       // added by [MouseJstr]
+    int min_hair_style;
+    int max_hair_style;
+    int min_hair_color;
+    int max_hair_color;
+    int min_cloth_color;
+    int max_cloth_color;
 
-    int castrate_dex_scale;    // added by [MouseJstr]
-    int area_size;             // added by [MouseJstr]
+    int castrate_dex_scale;
+    int area_size;
 
     int chat_lame_penalty;
     int chat_spam_threshold;
@@ -253,8 +194,8 @@ extern struct Battle_Config
 
     int mask_ip_gms;
 
-    int drop_pickup_safety_zone;   // [Fate] Max. distance to an object dropped by a kill by self in which dropsteal protection works
-    int itemheal_regeneration_factor;  // [Fate] itemheal speed factor
+    int drop_pickup_safety_zone;
+    int itemheal_regeneration_factor;
 
     int mob_splash_radius;
 } battle_config;
diff --git a/src/map/chrif.cpp b/src/map/chrif.cpp
index 33a9879..c9020a3 100644
--- a/src/map/chrif.cpp
+++ b/src/map/chrif.cpp
@@ -32,9 +32,7 @@ const int packet_len_table[0x20] =
 
 int char_fd;
 static
-IP_String char_ip_str;
-static
-int char_ip;
+IP4Address char_ip;
 static
 int char_port = 6121;
 static
@@ -72,10 +70,9 @@ AccountPass chrif_getpasswd(void)
  *
  *------------------------------------------
  */
-void chrif_setip(IP_String ip)
+void chrif_setip(IP4Address ip)
 {
-    char_ip_str = ip;
-    char_ip = inet_addr(char_ip_str.c_str());
+    char_ip = ip;
 }
 
 /*==========================================
@@ -134,7 +131,7 @@ int chrif_connect(int fd)
     WFIFO_STRING(fd, 2, userid, 24);
     WFIFO_STRING(fd, 26, passwd, 24);
     WFIFOL(fd, 50) = 0;
-    WFIFOL(fd, 54) = clif_getip().s_addr;
+    WFIFOIP(fd, 54) = clif_getip();
     WFIFOW(fd, 58) = clif_getport();  // [Valaris] thanks to fov
     WFIFOSET(fd, 60);
 
@@ -172,21 +169,21 @@ int chrif_sendmap(int fd)
 static
 int chrif_recvmap(int fd)
 {
-    int i, j, port;
+    int i, j;
 
     if (chrif_state < 2)        // まだ準備中
         return -1;
 
-    struct in_addr ip;
-    ip.s_addr = RFIFOL(fd, 4);
-    port = RFIFOW(fd, 8);
+    IP4Address ip = RFIFOIP(fd, 4);
+    uint16_t port = RFIFOW(fd, 8);
     for (i = 10, j = 0; i < RFIFOW(fd, 2); i += 16, j++)
     {
         MapName map = RFIFO_STRING<16>(fd, i);
         map_setipport(map, ip, port);
     }
     if (battle_config.etc_log)
-        PRINTF("recv map on %s:%d (%d maps)\n", ip2str(ip), port, j);
+        PRINTF("recv map on %s:%d (%d maps)\n",
+                ip, port, j);
 
     return 0;
 }
@@ -196,17 +193,16 @@ int chrif_recvmap(int fd)
  *------------------------------------------
  */
 int chrif_changemapserver(dumb_ptr<map_session_data> sd,
-        MapName name, int x, int y, struct in_addr ip, short port)
+        MapName name, int x, int y, IP4Address ip, short port)
 {
-    int i, s_ip;
-
     nullpo_retr(-1, sd);
 
-    s_ip = 0;
-    for (i = 0; i < fd_max; i++)
+    IP4Address s_ip;
+    for (int i = 0; i < fd_max; i++)
         if (session[i] && dumb_ptr<map_session_data>(static_cast<map_session_data *>(session[i]->session_data.get())) == sd)
         {
-            s_ip = session[i]->client_addr.sin_addr.s_addr;
+            assert (i == sd->fd);
+            s_ip = session[i]->client_ip;
             break;
         }
 
@@ -218,10 +214,10 @@ int chrif_changemapserver(dumb_ptr<map_session_data> sd,
     WFIFO_STRING(char_fd, 18, name, 16);
     WFIFOW(char_fd, 34) = x;
     WFIFOW(char_fd, 36) = y;
-    WFIFOL(char_fd, 38) = ip.s_addr;
+    WFIFOIP(char_fd, 38) = ip;
     WFIFOL(char_fd, 42) = port;
     WFIFOB(char_fd, 44) = sd->status.sex;
-    WFIFOL(char_fd, 45) = s_ip;
+    WFIFOIP(char_fd, 45) = s_ip;
     WFIFOSET(char_fd, 49);
 
     return 0;
@@ -249,7 +245,7 @@ int chrif_changemapserverack(int fd)
     MapName mapname = RFIFO_STRING<16>(fd, 18);
     uint16_t x = RFIFOW(fd, 34);
     uint16_t y = RFIFOW(fd, 36);
-    auto ip = in_addr{RFIFOL(fd, 38)};
+    IP4Address ip = RFIFOIP(fd, 38);
     uint16_t port = RFIFOW(fd, 42);
     clif_changemapserver(sd, mapname, x, y, ip, port);
 
@@ -311,22 +307,21 @@ int chrif_sendmapack(int fd)
  */
 int chrif_authreq(dumb_ptr<map_session_data> sd)
 {
-    int i;
-
     nullpo_retr(-1, sd);
 
     if (!sd || !char_fd || !sd->bl_id || !sd->login_id1)
         return -1;
 
-    for (i = 0; i < fd_max; i++)
+    for (int i = 0; i < fd_max; i++)
         if (session[i] && dumb_ptr<map_session_data>(static_cast<map_session_data *>(session[i]->session_data.get())) == sd)
         {
+            assert (i == sd->fd);
             WFIFOW(char_fd, 0) = 0x2afc;
             WFIFOL(char_fd, 2) = sd->bl_id;
             WFIFOL(char_fd, 6) = sd->char_id;
             WFIFOL(char_fd, 10) = sd->login_id1;
             WFIFOL(char_fd, 14) = sd->login_id2;
-            WFIFOL(char_fd, 18) = session[i]->client_addr.sin_addr.s_addr;
+            WFIFOIP(char_fd, 18) = session[i]->client_ip;
             WFIFOSET(char_fd, 22);
             break;
         }
@@ -340,18 +335,17 @@ int chrif_authreq(dumb_ptr<map_session_data> sd)
  */
 int chrif_charselectreq(dumb_ptr<map_session_data> sd)
 {
-    int i, s_ip;
-
     nullpo_retr(-1, sd);
 
     if (!sd || !char_fd || !sd->bl_id || !sd->login_id1)
         return -1;
 
-    s_ip = 0;
-    for (i = 0; i < fd_max; i++)
+    IP4Address s_ip;
+    for (int i = 0; i < fd_max; i++)
         if (session[i] && dumb_ptr<map_session_data>(static_cast<map_session_data *>(session[i]->session_data.get())) == sd)
         {
-            s_ip = session[i]->client_addr.sin_addr.s_addr;
+            assert (i == sd->fd);
+            s_ip = session[i]->client_ip;
             break;
         }
 
@@ -359,29 +353,13 @@ int chrif_charselectreq(dumb_ptr<map_session_data> sd)
     WFIFOL(char_fd, 2) = sd->bl_id;
     WFIFOL(char_fd, 6) = sd->login_id1;
     WFIFOL(char_fd, 10) = sd->login_id2;
-    WFIFOL(char_fd, 14) = s_ip;
+    WFIFOIP(char_fd, 14) = s_ip;
     WFIFOSET(char_fd, 18);
 
     return 0;
 }
 
 /*==========================================
- * キャラ名問い合わせ
- *------------------------------------------
- */
-int chrif_searchcharid(int char_id)
-{
-    if (!char_id)
-        return -1;
-
-    WFIFOW(char_fd, 0) = 0x2b08;
-    WFIFOL(char_fd, 2) = char_id;
-    WFIFOSET(char_fd, 6);
-
-    return 0;
-}
-
-/*==========================================
  * GMに変化要求
  *------------------------------------------
  */
@@ -1108,13 +1086,6 @@ void chrif_parse(int fd)
             case 0x2b06:
                 chrif_changemapserverack(fd);
                 break;
-            case 0x2b09:
-            {
-                int charid = RFIFOL(fd, 2);
-                CharName name = stringish<CharName>(RFIFO_STRING<24>(fd, 6));
-                map_addchariddb(charid, name);
-            }
-                break;
             case 0x2b0b:
                 chrif_changedgm(fd);
                 break;
diff --git a/src/map/chrif.hpp b/src/map/chrif.hpp
index 97760c3..dfcc12b 100644
--- a/src/map/chrif.hpp
+++ b/src/map/chrif.hpp
@@ -3,6 +3,7 @@
 
 #include "../common/dumb_ptr.hpp"
 #include "../common/human_time_diff.hpp"
+#include "../common/ip.hpp"
 
 #include "map.hpp"
 
@@ -10,7 +11,7 @@ void chrif_setuserid(AccountName);
 void chrif_setpasswd(AccountPass);
 AccountPass chrif_getpasswd(void);
 
-void chrif_setip(IP_String);
+void chrif_setip(IP4Address);
 void chrif_setport(int);
 
 int chrif_isconnect(void);
@@ -21,9 +22,8 @@ int chrif_charselectreq(dumb_ptr<map_session_data>);
 
 int chrif_changemapserver(dumb_ptr<map_session_data> sd,
         MapName name, int x, int y,
-        struct in_addr ip, short port);
+        IP4Address ip, short port);
 
-int chrif_searchcharid(int char_id);
 void chrif_changegm(int id, ZString pass);
 void chrif_changeemail(int id, AccountEmail actual_email, AccountEmail new_email);
 void chrif_char_ask_name(int id, CharName character_name, short operation_type,
diff --git a/src/map/clif.cpp b/src/map/clif.cpp
index fa208be..e068249 100644
--- a/src/map/clif.cpp
+++ b/src/map/clif.cpp
@@ -107,9 +107,7 @@ void WFIFOPOS2(int fd, size_t pos, uint16_t x0, uint16_t y0, uint16_t x1, uint16
 }
 
 static
-IP_String map_ip_str;
-static
-struct in_addr map_ip;
+IP4Address map_ip;
 static
 int map_port = 5121;
 
@@ -121,10 +119,9 @@ int clif_changelook_towards(dumb_ptr<block_list> bl, LOOK type, int val,
  * map鯖のip設定
  *------------------------------------------
  */
-void clif_setip(IP_String ip)
+void clif_setip(IP4Address ip)
 {
-    map_ip_str = ip;
-    map_ip.s_addr = inet_addr(map_ip_str.c_str());
+    map_ip = ip;
 }
 
 /*==========================================
@@ -140,7 +137,7 @@ void clif_setport(int port)
  * map鯖のip読み出し
  *------------------------------------------
  */
-struct in_addr clif_getip(void)
+IP4Address clif_getip(void)
 {
     return map_ip;
 }
@@ -1114,7 +1111,7 @@ void clif_changemap(dumb_ptr<map_session_data> sd, MapName mapname, int x, int y
  *------------------------------------------
  */
 void clif_changemapserver(dumb_ptr<map_session_data> sd,
-        MapName mapname, int x, int y, struct in_addr ip, int port)
+        MapName mapname, int x, int y, IP4Address ip, int port)
 {
     nullpo_retv(sd);
 
@@ -1123,7 +1120,7 @@ void clif_changemapserver(dumb_ptr<map_session_data> sd,
     WFIFO_STRING(fd, 2, mapname, 16);
     WFIFOW(fd, 18) = x;
     WFIFOW(fd, 20) = y;
-    WFIFOL(fd, 22) = ip.s_addr;
+    WFIFOIP(fd, 22) = ip;
     WFIFOW(fd, 26) = port;
     WFIFOSET(fd, clif_parse_func_table[0x92].len);
 }
@@ -3526,9 +3523,9 @@ void clif_parse_LoadEndAck(int, dumb_ptr<map_session_data> sd)
     // 119
     // 78
 
-    if (battle_config.pc_invincible_time > 0)
+    if (battle_config.player_invincible_time > 0)
     {
-        pc_setinvincibletimer(sd, static_cast<interval_t>(battle_config.pc_invincible_time));
+        pc_setinvincibletimer(sd, static_cast<interval_t>(battle_config.player_invincible_time));
     }
 
     map_addblock(sd);     // ブロック登録
@@ -3735,15 +3732,15 @@ void clif_parse_GetCharNameRequest(int fd, dumb_ptr<map_session_data> sd)
 
             if (pc_isGM(sd) >= battle_config.hack_info_GM_level)
             {
-                struct in_addr ip = ssd->ip;
+                IP4Address ip = ssd->get_ip();
                 WFIFOW(fd, 0) = 0x20C;
 
                 // Mask the IP using the char-server password
                 if (battle_config.mask_ip_gms)
-                    ip = MD5_ip(ssd->ip);
+                    ip = MD5_ip(ip);
 
                 WFIFOL(fd, 2) = account_id;
-                WFIFOL(fd, 6) = ip.s_addr;
+                WFIFOIP(fd, 6) = ip;
                 WFIFOSET(fd, clif_parse_func_table[0x20C].len);
              }
 
@@ -3944,7 +3941,7 @@ void clif_parse_ActionRequest(int fd, dumb_ptr<map_session_data> sd)
         case 0x07:             // continuous attack
             if (bool(sd->status.option & Option::HIDE))
                 return;
-            if (!battle_config.sdelay_attack_enable)
+            if (!battle_config.skill_delay_attack_enable)
             {
                 if (tick < sd->canact_tick)
                 {
diff --git a/src/map/clif.hpp b/src/map/clif.hpp
index 20f9912..fa68e23 100644
--- a/src/map/clif.hpp
+++ b/src/map/clif.hpp
@@ -6,6 +6,7 @@
 #include <functional>
 
 #include "../common/const_array.hpp"
+#include "../common/ip.hpp"
 #include "../common/strings.hpp"
 #include "../common/timer.t.hpp"
 
@@ -14,10 +15,10 @@
 #include "pc.t.hpp"
 #include "skill.t.hpp"
 
-void clif_setip(IP_String);
+void clif_setip(IP4Address);
 void clif_setport(int);
 
-struct in_addr clif_getip(void);
+IP4Address clif_getip(void);
 int clif_getport(void);
 int clif_countusers(void);
 void clif_setwaitclose(int);
@@ -39,7 +40,7 @@ int clif_walkok(dumb_ptr<map_session_data>);   // self
 int clif_movechar(dumb_ptr<map_session_data>); // area
 int clif_movemob(dumb_ptr<mob_data>);  //area
 void clif_changemap(dumb_ptr<map_session_data>, MapName, int, int);  //self
-void clif_changemapserver(dumb_ptr<map_session_data>, MapName, int, int, struct in_addr, int);  //self
+void clif_changemapserver(dumb_ptr<map_session_data>, MapName, int, int, IP4Address, int);  //self
 void clif_fixpos(dumb_ptr<block_list>); // area
 int clif_fixmobpos(dumb_ptr<mob_data> md);
 int clif_fixpcpos(dumb_ptr<map_session_data> sd);
diff --git a/src/map/map.cpp b/src/map/map.cpp
index f2eefe5..25b70dc 100644
--- a/src/map/map.cpp
+++ b/src/map/map.cpp
@@ -64,7 +64,7 @@ dumb_ptr<block_list> object[MAX_FLOORITEM];
 static
 int first_free_object_id = 0, last_object_id = 0;
 
-interval_t autosave_interval = DEFAULT_AUTOSAVE_INTERVAL;
+interval_t autosave_time = DEFAULT_AUTOSAVE_INTERVAL;
 int save_settings = 0xFFFF;
 
 FString motd_txt = "conf/motd.txt";
@@ -1078,7 +1078,7 @@ map_local *map_mapname2mapid(MapName name)
  * 他鯖map名からip,port変換
  *------------------------------------------
  */
-int map_mapname2ipport(MapName name, struct in_addr *ip, int *port)
+int map_mapname2ipport(MapName name, IP4Address *ip, int *port)
 {
     map_abstract *md = maps_db.get(name);
     if (md == NULL || md->gat)
@@ -1187,7 +1187,7 @@ void map_setcell(map_local *m, int x, int y, MapCell t)
  * 他鯖管理のマップをdbに追加
  *------------------------------------------
  */
-int map_setipport(MapName name, struct in_addr ip, int port)
+int map_setipport(MapName name, IP4Address ip, int port)
 {
     map_abstract *md = maps_db.get(name);
     if (md == NULL)
@@ -1205,10 +1205,10 @@ int map_setipport(MapName name, struct in_addr ip, int port)
         if (md->gat)
         {
             // local -> check data
-            if (ip.s_addr != clif_getip().s_addr || port != clif_getport())
+            if (ip != clif_getip() || port != clif_getport())
             {
-                PRINTF("from char server : %s -> %s:%d\n", name, ip2str(ip),
-                        port);
+                PRINTF("from char server : %s -> %s:%d\n",
+                        name, ip, port);
                 return 1;
             }
         }
@@ -1450,19 +1450,23 @@ int map_config_read(ZString cfgName)
         else if (w1 == "char_ip")
         {
             h = gethostbyname(w2.c_str());
-            IP_String w2ip;
+            IP4Address w2ip;
             if (h != NULL)
             {
-                SNPRINTF(w2ip, 16, "%d.%d.%d.%d",
+                w2ip = IP4Address({
                         static_cast<uint8_t>(h->h_addr[0]),
                         static_cast<uint8_t>(h->h_addr[1]),
                         static_cast<uint8_t>(h->h_addr[2]),
-                        static_cast<uint8_t>(h->h_addr[3]));
+                        static_cast<uint8_t>(h->h_addr[3]),
+                });
                 PRINTF("Character server IP address : %s -> %s\n",
                         w2, w2ip);
             }
             else
-                w2ip = stringish<IP_String>(w2);
+            {
+                PRINTF("Bad IP value: %s\n", line);
+                abort();
+            }
             chrif_setip(w2ip);
         }
         else if (w1 == "char_port")
@@ -1472,19 +1476,23 @@ int map_config_read(ZString cfgName)
         else if (w1 == "map_ip")
         {
             h = gethostbyname(w2.c_str());
-            IP_String w2ip;
+            IP4Address w2ip;
             if (h != NULL)
             {
-                SNPRINTF(w2ip, 16, "%d.%d.%d.%d",
-                         static_cast<uint8_t>(h->h_addr[0]),
-                         static_cast<uint8_t>(h->h_addr[1]),
-                         static_cast<uint8_t>(h->h_addr[2]),
-                         static_cast<uint8_t>(h->h_addr[3]));
+                w2ip = IP4Address({
+                        static_cast<uint8_t>(h->h_addr[0]),
+                        static_cast<uint8_t>(h->h_addr[1]),
+                        static_cast<uint8_t>(h->h_addr[2]),
+                        static_cast<uint8_t>(h->h_addr[3]),
+                });
                 PRINTF("Map server IP address : %s -> %s\n",
                         w2, w2ip);
             }
             else
-                w2ip = stringish<IP_String>(w2);
+            {
+                PRINTF("Bad IP value: %s\n", line);
+                abort();
+            }
             clif_setip(w2ip);
         }
         else if (w1 == "map_port")
@@ -1511,9 +1519,9 @@ int map_config_read(ZString cfgName)
         }
         else if (w1 == "autosave_time")
         {
-            autosave_interval = std::chrono::seconds(atoi(w2.c_str()));
-            if (autosave_interval <= interval_t::zero())
-                autosave_interval = DEFAULT_AUTOSAVE_INTERVAL;
+            autosave_time = std::chrono::seconds(atoi(w2.c_str()));
+            if (autosave_time <= interval_t::zero())
+                autosave_time = DEFAULT_AUTOSAVE_INTERVAL;
         }
         else if (w1 == "motd_txt")
         {
@@ -1529,7 +1537,7 @@ int map_config_read(ZString cfgName)
         }
         else if (w1 == "gm_log")
         {
-            gm_logfile_name = std::move(w2);
+            gm_log = std::move(w2);
         }
         else if (w1 == "log_file")
         {
diff --git a/src/map/map.hpp b/src/map/map.hpp
index d98900d..4d5ac9d 100644
--- a/src/map/map.hpp
+++ b/src/map/map.hpp
@@ -165,7 +165,7 @@ struct map_session_data : block_list, SessionData
     int weight, max_weight;
     int cart_weight, cart_max_weight, cart_num, cart_max_num;
     MapName mapname_;
-    int fd, new_fd;
+    int fd; // use this, you idiots!
     short to_x, to_y;
     interval_t speed;
     Opt1 opt1;
@@ -299,7 +299,10 @@ struct map_session_data : block_list, SessionData
     TimeT packet_flood_reset_due;
     int packet_flood_in;
 
-    struct in_addr ip;
+    IP4Address get_ip()
+    {
+        return session[fd]->client_ip;
+    }
 };
 
 struct npc_timerevent_list
@@ -539,8 +542,8 @@ struct map_local : map_abstract
 
 struct map_remote : map_abstract
 {
-    struct in_addr ip;
-    unsigned int port;
+    IP4Address ip;
+    uint16_t port;
 };
 
 inline
@@ -558,7 +561,7 @@ struct flooritem_data : block_list
     struct item item_data;
 };
 
-extern interval_t autosave_interval;
+extern interval_t autosave_time;
 extern int save_settings;
 
 extern FString motd_txt;
@@ -708,8 +711,8 @@ dumb_ptr<invocation> map_id_is_spell(int id)
 
 
 map_local *map_mapname2mapid(MapName);
-int map_mapname2ipport(MapName, struct in_addr *, int *);
-int map_setipport(MapName name, struct in_addr ip, int port);
+int map_mapname2ipport(MapName, IP4Address *, int *);
+int map_setipport(MapName name, IP4Address ip, int port);
 void map_addiddb(dumb_ptr<block_list>);
 void map_deliddb(dumb_ptr<block_list> bl);
 void map_addnickdb(dumb_ptr<map_session_data>);
diff --git a/src/map/mob.cpp b/src/map/mob.cpp
index cd548a4..b8158af 100644
--- a/src/map/mob.cpp
+++ b/src/map/mob.cpp
@@ -3001,12 +3001,12 @@ void mobskill_castend_id(TimerData *, tick_t tick, int id)
     range = skill_get_range(md->skillid, md->skilllv);
     if (range < 0)
         range = battle_get_range(md) - (range + 1);
-    if (range + battle_config.mob_skill_add_range < distance(md->bl_x, md->bl_y, bl->bl_x, bl->bl_y))
+    if (range + battle_config.monster_skill_add_range < distance(md->bl_x, md->bl_y, bl->bl_x, bl->bl_y))
         return;
 
     md->skilldelayup[md->skillidx - &mob_db[md->mob_class].skills.front()] = tick;
 
-    if (battle_config.mob_skill_log == 1)
+    if (battle_config.monster_skill_log == 1)
         PRINTF("MOB skill castend skill=%d, mob_class = %d\n",
                 md->skillid, md->mob_class);
     mob_stop_walking(md, 0);
@@ -3053,11 +3053,11 @@ void mobskill_castend_pos(TimerData *, tick_t tick, int id)
     range = skill_get_range(md->skillid, md->skilllv);
     if (range < 0)
         range = battle_get_range(md) - (range + 1);
-    if (range + battle_config.mob_skill_add_range < distance(md->bl_x, md->bl_y, md->skillx, md->skilly))
+    if (range + battle_config.monster_skill_add_range < distance(md->bl_x, md->bl_y, md->skillx, md->skilly))
         return;
     md->skilldelayup[md->skillidx - &mob_db[md->mob_class].skills.front()] = tick;
 
-    if (battle_config.mob_skill_log == 1)
+    if (battle_config.monster_skill_log == 1)
         PRINTF("MOB skill castend skill=%d, mob_class = %d\n",
                 md->skillid, md->mob_class);
     mob_stop_walking(md, 0);
@@ -3107,7 +3107,7 @@ int mobskill_use_id(dumb_ptr<mob_data> md, dumb_ptr<block_list> target,
     md->state.skillcastcancel = ms->cancel;
     md->skilldelayup[ms - &mob_db[md->mob_class].skills.front()] = gettick();
 
-    if (battle_config.mob_skill_log == 1)
+    if (battle_config.monster_skill_log == 1)
         PRINTF("MOB skill use target_id=%d skill=%d lv=%d cast=%d, mob_class = %d\n",
                 target->bl_id, skill_id, skill_lv,
                 static_cast<uint32_t>(casttime.count()), md->mob_class);
@@ -3178,7 +3178,7 @@ int mobskill_use_pos(dumb_ptr<mob_data> md,
     md->skilldelayup[ms - &mob_db[md->mob_class].skills.front()] = gettick();
     md->state.skillcastcancel = ms->cancel;
 
-    if (battle_config.mob_skill_log == 1)
+    if (battle_config.monster_skill_log == 1)
         PRINTF("MOB skill use target_pos= (%d,%d) skill=%d lv=%d cast=%d, mob_class = %d\n",
              skill_x, skill_y, skill_id, skill_lv,
              static_cast<uint32_t>(casttime.count()), md->mob_class);
diff --git a/src/map/pc.cpp b/src/map/pc.cpp
index 7b0af59..5fdb390 100644
--- a/src/map/pc.cpp
+++ b/src/map/pc.cpp
@@ -583,8 +583,8 @@ int pc_isequip(dumb_ptr<map_session_data> sd, int n)
     item = sd->inventory_data[n];
     sc_data = battle_get_sc_data(sd);
 
-    if (battle_config.gm_allequip > 0
-        && pc_isGM(sd) >= battle_config.gm_allequip)
+    if (battle_config.gm_all_equipment > 0
+        && pc_isGM(sd) >= battle_config.gm_all_equipment)
         return 1;
 
     if (item == NULL)
@@ -609,8 +609,6 @@ int pc_authok(int id, int login_id2, TimeT connect_until_time,
 
     struct party *p;
     tick_t tick = gettick();
-    struct sockaddr_in sai;
-    socklen_t sa_len = sizeof(struct sockaddr);
 
     sd = map_id2sd(id);
     if (sd == NULL)
@@ -759,10 +757,6 @@ int pc_authok(int id, int login_id2, TimeT connect_until_time,
     sd->packet_flood_reset_due = TimeT();
     sd->packet_flood_in = 0;
 
-    // Obtain IP address (if they are still connected)
-    if (!getpeername(sd->fd, reinterpret_cast<struct sockaddr *>(&sai), &sa_len))
-        sd->ip = sai.sin_addr;
-
     // message of the limited time of the account
     if (connect_until_time)
     {
@@ -2308,7 +2302,7 @@ int pc_setpos(dumb_ptr<map_session_data> sd,
     {
         if (sd->mapname_)
         {
-            struct in_addr ip;
+            IP4Address ip;
             int port;
             if (map_mapname2ipport(mapname_, &ip, &port) == 0)
             {
@@ -2638,7 +2632,7 @@ int pc_stop_walking(dumb_ptr<map_session_data> sd, int type)
     sd->to_y = sd->bl_y;
     if (type & 0x01)
         clif_fixpos(sd);
-    if (type & 0x02 && battle_config.pc_damage_delay)
+    if (type & 0x02 && battle_config.player_damage_delay)
     {
         tick_t tick = gettick();
         interval_t delay = battle_get_dmotion(sd);
@@ -2794,7 +2788,7 @@ void pc_attack_timer(TimerData *, tick_t tick, int id)
     if (opt != NULL && bool(*opt & Option::REAL_ANY_HIDE))
         return;
 
-    if (!battle_config.sdelay_attack_enable)
+    if (!battle_config.skill_delay_attack_enable)
     {
         if (tick < sd->canact_tick)
         {
@@ -2837,7 +2831,7 @@ void pc_attack_timer(TimerData *, tick_t tick, int id)
         }
         else
         {
-            if (battle_config.pc_attack_direction_change)
+            if (battle_config.player_attack_direction_change)
                 sd->dir = sd->head_dir = map_calc_dir(sd, bl->bl_x, bl->bl_y);  // 向き設定
 
             if (sd->walktimer)
@@ -5207,7 +5201,7 @@ void pc_autosave(TimerData *, tick_t)
     if (save_flag == 0)
         last_save_fd = 0;
 
-    interval_t interval = autosave_interval / (clif_countusers() + 1);
+    interval_t interval = autosave_time / (clif_countusers() + 1);
     if (interval <= interval_t::zero())
         interval = std::chrono::milliseconds(1);
     Timer(gettick() + interval,
@@ -5265,7 +5259,7 @@ int do_init_pc(void)
             pc_natural_heal,
             NATURAL_HEAL_INTERVAL
     ).detach();
-    Timer(gettick() + autosave_interval,
+    Timer(gettick() + autosave_time,
             pc_autosave
     ).detach();
 
diff --git a/src/map/script.cpp b/src/map/script.cpp
index 5e96a9f..f7eecca 100644
--- a/src/map/script.cpp
+++ b/src/map/script.cpp
@@ -66,7 +66,7 @@ Map<ScriptLabel, int> scriptlabel_db;
 UPMap<FString, const ScriptBuffer> userfunc_db;
 
 static
-const char *pos[11] =
+const char *pos_str[11] =
 {
     "Head",
     "Body",
@@ -2227,13 +2227,13 @@ void builtin_getequipname(ScriptState *st)
     {
         item = sd->inventory_data[i];
         if (item)
-            buf = STRPRINTF("%s-[%s]", pos[num - 1], item->jname);
+            buf = STRPRINTF("%s-[%s]", pos_str[num - 1], item->jname);
         else
-            buf = STRPRINTF("%s-[%s]", pos[num - 1], pos[10]);
+            buf = STRPRINTF("%s-[%s]", pos_str[num - 1], pos_str[10]);
     }
     else
     {
-        buf = STRPRINTF("%s-[%s]", pos[num - 1], pos[10]);
+        buf = STRPRINTF("%s-[%s]", pos_str[num - 1], pos_str[10]);
     }
     push_str(st->stack, ByteCode::STR, dumb_string::copys(buf));
 
diff --git a/src/map/skill.cpp b/src/map/skill.cpp
index 7489731..f868b41 100644
--- a/src/map/skill.cpp
+++ b/src/map/skill.cpp
@@ -582,7 +582,7 @@ interval_t skill_castfix(dumb_ptr<block_list> bl, interval_t interval)
             interval * castrate * (battle_config.castrate_dex_scale -
                                dex) / (battle_config.castrate_dex_scale *
                                        100);
-        interval = interval * battle_config.cast_rate / 100;
+        interval = interval * battle_config.casting_rate / 100;
     }
 
     return std::max(interval, interval_t::zero());