summaryrefslogtreecommitdiff
path: root/src/monitor/main.cpp
blob: c27cf77b8206dac550a97247a17c4f6518cf2f3e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
//    monitor/main.cpp - Old daemon to restart servers when they crashed.
//
//    Copyright © ???? Bartosz Waszak <waszi@evil.org.pl>
//    Copyright © 2011-2014 Ben Longbons <b.r.longbons@gmail.com>
//
//    This file is part of The Mana World (Athena server)
//
//    This program is free software: you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation, either version 3 of the License, or
//    (at your option) any later version.
//
//    This program is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU General Public License for more details.
//
//    You should have received a copy of the GNU General Public License
//    along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include <sys/wait.h>

#include <fcntl.h>
#include <unistd.h>

#include <csignal>
#include <cstdlib>

#include "../strings/mstring.hpp"
#include "../strings/astring.hpp"
#include "../strings/zstring.hpp"
#include "../strings/xstring.hpp"
#include "../strings/literal.hpp"

#include "../io/cxxstdio.hpp"
#include "../io/fd.hpp"
#include "../io/read.hpp"

#include "../mmo/config_parse.hpp"

#include "../net/timestamp-utils.hpp"

#include "../poison.hpp"

#define LOGIN_SERVER "./login-server"_s
#define MAP_SERVER "./map-server"_s
#define CHAR_SERVER "./char-server"_s
#define CONFIG "conf/eathena-monitor.conf"_s


namespace tmwa
{
// initialiized to $HOME/tmwserver
static
AString workdir;
//the rest are relative to workdir
static
AString login_server = LOGIN_SERVER;
static
AString map_server = MAP_SERVER;
static
AString char_server = CHAR_SERVER;

static
pid_t pid_login, pid_map, pid_char;

static
AString make_path(XString base, XString path)
{
    MString m;
    m += base;
    m += '/';
    m += path;
    return AString(m);
}

static
bool parse_option(XString name, ZString value)
{
    if (name == "login_server"_s)
        login_server = value;
    else if (name == "map_server"_s)
        map_server = value;
    else if (name == "char_server"_s)
        char_server = value;
    else if (name == "workdir"_s)
        workdir = value;
    else
    {
        FPRINTF(stderr, "WARNING: ingnoring invalid option '%s' : '%s'\n"_fmt,
                AString(name), value);
        return false;
    }
    return true;
}

static
bool read_config(ZString filename)
{
    bool rv = true;
    io::ReadFile in(filename);
    if (!in.is_open())
    {
        FPRINTF(stderr, "Monitor config file not found: %s\n"_fmt, filename);
        exit(1);
    }

    AString line;
    while (in.getline(line))
    {
        if (is_comment(line))
            continue;
        XString name;
        ZString value;
        if (!config_split(line, &name, &value))
        {
            PRINTF("Bad line: %s\n"_fmt, line);
            rv = false;
            continue;
        }

        if (!parse_option(name, value))
        {
            PRINTF("Bad key/value: %s\n"_fmt, line);
            rv = false;
            continue;
        }
    }
    return rv;
}

static
pid_t start_process(ZString exec)
{
    const char *args[2] = {exec.c_str(), nullptr};
    pid_t pid = fork();
    if (pid == -1)
    {
        FPRINTF(stderr, "Failed to fork"_fmt);
        return 0;
    }
    if (pid == 0)
    {
        DIAG_PUSH();
        DIAG_I(cast_qual);
        execv(exec.c_str(), const_cast<char **>(args));
        DIAG_POP();
        perror("Failed to exec");
        kill(getppid(), SIGABRT);
        exit(1);
    }
    return pid;
}

// Kill all children with the same signal we got, then ourself.
static
void stop_process(int sig)
{
    if (pid_map)
        kill(pid_map, sig);
    if (pid_login)
        kill(pid_login, sig);
    if (pid_char)
        kill(pid_char, sig);
    DIAG_PUSH();
    DIAG_I(old_style_cast);
    DIAG_I(zero_as_null_pointer_constant);
    signal(sig, SIG_DFL);
    DIAG_POP();
    raise(sig);
}
} // namespace tmwa

int main(int argc, char *argv[])
{
    using namespace tmwa;
    // These are all the signals we are likely to get
    // The shell handles stop/cont
    signal(SIGTERM, stop_process);
    signal(SIGINT, stop_process);
    signal(SIGQUIT, stop_process);
    signal(SIGABRT, stop_process);

    workdir = make_path(ZString(strings::really_construct_from_a_pointer, getenv("HOME"), nullptr), "tmwserver"_s);

    ZString config = CONFIG;
    if (argc > 1)
        config = ZString(strings::really_construct_from_a_pointer, argv[1], nullptr);
    read_config(config);

    if (chdir(workdir.c_str()) < 0)
    {
        perror("Failed to change directory");
        exit(1);
    }

    PRINTF("Starting:\n"_fmt);
    PRINTF("* workdir: %s\n"_fmt,  workdir);
    PRINTF("* login_server: %s\n"_fmt, login_server);
    PRINTF("* char_server: %s\n"_fmt, char_server);
    PRINTF("* map_server: %s\n"_fmt, map_server);
    {
        //make sure all possible file descriptors are free for use by the servers
        //if there are file descriptors higher than the max open from before the limit dropped, that's not our problem
        io::FD fd = io::FD::sysconf_SC_OPEN_MAX();
        while ((fd = fd.prev()) > io::FD::stderr())
        {
            if (fd.close() == 0)
                FPRINTF(stderr, "close fd %d\n"_fmt, fd.uncast_dammit());
        }
        fd = io::FD::open("/dev/null"_s, O_RDWR);
        if (fd == io::FD())
        {
            perror("open /dev/null");
            exit(1);
        }
        fd.dup2(io::FD::stdin());
        fd.dup2(io::FD::stdout());
        fd.close();
    }
    while (1)
    {
        // write stuff to stderr
        timestamp_seconds_buffer timestamp;
        stamp_time(timestamp);

        if (!pid_login)
        {
            pid_login = start_process(login_server);
            FPRINTF(stderr, "[%s] forked login server: %lu\n"_fmt,
                    timestamp, static_cast<unsigned long>(pid_login));
        }
        if (!pid_char)
        {
            pid_char = start_process(char_server);
            FPRINTF(stderr, "[%s] forked char server: %lu\n"_fmt,
                    timestamp, static_cast<unsigned long>(pid_char));
        }
        if (!pid_map)
        {
            pid_map = start_process(map_server);
            FPRINTF(stderr, "[%s] forked map server: %lu\n"_fmt,
                    timestamp, static_cast<unsigned long>(pid_map));
        }
        pid_t dead = wait(nullptr);
        if (dead == -1)
        {
            perror("Failed to wait for child");
            exit(1);
        }
        if (pid_login == dead)
            pid_login = 0;
        if (pid_char == dead)
            pid_char = 0;
        if (pid_map == dead)
            pid_map = 0;
    }
}