summaryrefslogtreecommitdiff
path: root/src/mmo/socket.cpp
blob: 2fec6c1f8e51a9b0b064a5fb915c045c8a9bdf95 (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
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
#include "socket.hpp"
//    socket.cpp - Network event system.
//
//    Copyright © ????-2004 Athena Dev Teams
//    Copyright © 2004-2011 The Mana World Development Team
//    Copyright © 2011-2014 Ben Longbons <b.r.longbons@gmail.com>
//    Copyright © 2013 MadCamel
//
//    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 <arpa/inet.h>
#include <netinet/tcp.h>
#include <sys/socket.h>
//#include <sys/types.h>

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

#include <cstdlib>
#include <cstring>
#include <ctime>

#include "../io/cxxstdio.hpp"
#include "core.hpp"
#include "timer.hpp"
#include "utils.hpp"

#include "../poison.hpp"

static
io::FD_Set readfds;
static
int fd_max;

static
const uint32_t RFIFO_SIZE = 65536;
static
const uint32_t WFIFO_SIZE = 65536;

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wold-style-cast"
static
std::array<std::unique_ptr<Session>, FD_SETSIZE> session;
#pragma GCC diagnostic pop

Session::Session(SessionIO io, SessionParsers p)
: created()
, connected()
, eof()
, timed_close()
, rdata(), wdata()
, max_rdata(), max_wdata()
, rdata_size(), wdata_size()
, rdata_pos()
, client_ip()
, func_recv()
, func_send()
, func_parse()
, func_delete()
, for_inferior()
, session_data()
, fd()
{
    set_io(io);
    set_parsers(p);
}
void Session::set_io(SessionIO io)
{
    func_send = io.func_send;
    func_recv = io.func_recv;
}
void Session::set_parsers(SessionParsers p)
{
    func_parse = p.func_parse;
    func_delete = p.func_delete;
}


void set_session(io::FD fd, std::unique_ptr<Session> sess)
{
    int f = fd.uncast_dammit();
    assert (0 <= f && f < FD_SETSIZE);
    session[f] = std::move(sess);
}
Session *get_session(io::FD fd)
{
    int f = fd.uncast_dammit();
    if (0 <= f && f < FD_SETSIZE)
        return session[f].get();
    return nullptr;
}
void reset_session(io::FD fd)
{
    int f = fd.uncast_dammit();
    assert (0 <= f && f < FD_SETSIZE);
    session[f] = nullptr;
}
int get_fd_max() { return fd_max; }
IteratorPair<ValueIterator<io::FD, IncrFD>> iter_fds()
{
    return {io::FD::cast_dammit(0), io::FD::cast_dammit(fd_max)};
}

/// clean up by discarding handled bytes
inline
void RFIFOFLUSH(Session *s)
{
    really_memmove(&s->rdata[0], &s->rdata[s->rdata_pos], RFIFOREST(s));
    s->rdata_size = RFIFOREST(s);
    s->rdata_pos = 0;
}

/// how much room there is to read more data
inline
size_t RFIFOSPACE(Session *s)
{
    return s->max_rdata - s->rdata_size;
}


/// Read from socket to the queue
static
void recv_to_fifo(Session *s)
{
    ssize_t len = s->fd.read(&s->rdata[s->rdata_size],
                        RFIFOSPACE(s));

    if (len > 0)
    {
        s->rdata_size += len;
        s->connected = 1;
    }
    else
    {
        s->set_eof();
    }
}

static
void send_from_fifo(Session *s)
{
    ssize_t len = s->fd.write(&s->wdata[0], s->wdata_size);

    if (len > 0)
    {
        s->wdata_size -= len;
        if (s->wdata_size)
        {
            really_memmove(&s->wdata[0], &s->wdata[len],
                     s->wdata_size);
        }
        s->connected = 1;
    }
    else
    {
        s->set_eof();
    }
}

static
void nothing_delete(Session *s)
{
    (void)s;
}

static
void connect_client(Session *ls)
{
    struct sockaddr_in client_address;
    socklen_t len = sizeof(client_address);

    io::FD fd = ls->fd.accept(reinterpret_cast<struct sockaddr *>(&client_address), &len);
    if (fd == io::FD())
    {
        perror("accept");
        return;
    }
    if (fd.uncast_dammit() >= SOFT_LIMIT)
    {
        FPRINTF(stderr, "softlimit reached, disconnecting : %d\n"_fmt, fd.uncast_dammit());
        fd.shutdown(SHUT_RDWR);
        fd.close();
        return;
    }
    if (fd_max <= fd.uncast_dammit())
    {
        fd_max = fd.uncast_dammit() + 1;
    }

    const int yes = 1;
    /// Allow to bind() again after the server restarts.
    // Since the socket is still in the TIME_WAIT, there's a possibility
    // that formerly lost packets might be delivered and confuse the server.
    fd.setsockopt(SOL_SOCKET, SO_REUSEADDR, &yes, sizeof yes);
    /// Send packets as soon as possible
    /// even if the kernel thinks there is too little for it to be worth it!
    /// Testing shows this is indeed a good idea.
    fd.setsockopt(IPPROTO_TCP, TCP_NODELAY, &yes, sizeof yes);

    // Linux-ism: Set socket options to optimize for thin streams
    // See http://lwn.net/Articles/308919/ and
    // Documentation/networking/tcp-thin.txt .. Kernel 3.2+
#ifdef TCP_THIN_LINEAR_TIMEOUTS
    fd.setsockopt(IPPROTO_TCP, TCP_THIN_LINEAR_TIMEOUTS, &yes, sizeof yes);
#endif
#ifdef TCP_THIN_DUPACK
    fd.setsockopt(IPPROTO_TCP, TCP_THIN_DUPACK, &yes, sizeof yes);
#endif

    readfds.set(fd);

    fd.fcntl(F_SETFL, O_NONBLOCK);

    set_session(fd, make_unique<Session>(
                SessionIO{func_recv: recv_to_fifo, func_send: send_from_fifo},
                ls->for_inferior));
    Session *s = get_session(fd);
    s->fd = fd;
    s->rdata.new_(RFIFO_SIZE);
    s->wdata.new_(WFIFO_SIZE);
    s->max_rdata = RFIFO_SIZE;
    s->max_wdata = WFIFO_SIZE;
    s->client_ip = IP4Address(client_address.sin_addr);
    s->created = TimeT::now();
    s->connected = 0;
}

Session *make_listen_port(uint16_t port, SessionParsers inferior)
{
    struct sockaddr_in server_address;
    io::FD fd = io::FD::socket(AF_INET, SOCK_STREAM, 0);
    if (fd == io::FD())
    {
        perror("socket");
        return nullptr;
    }
    if (fd_max <= fd.uncast_dammit())
        fd_max = fd.uncast_dammit() + 1;

    fd.fcntl(F_SETFL, O_NONBLOCK);

    const int yes = 1;
    /// Allow to bind() again after the server restarts.
    // Since the socket is still in the TIME_WAIT, there's a possibility
    // that formerly lost packets might be delivered and confuse the server.
    fd.setsockopt(SOL_SOCKET, SO_REUSEADDR, &yes, sizeof yes);
    /// Send packets as soon as possible
    /// even if the kernel thinks there is too little for it to be worth it!
    // I'm not convinced this is a good idea; although in minimizes the
    // latency for an individual write, it increases traffic in general.
    fd.setsockopt(IPPROTO_TCP, TCP_NODELAY, &yes, sizeof yes);

    server_address.sin_family = AF_INET;
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wold-style-cast"
#if __GNUC__ > 4 || __GNUC_MINOR__ >= 8
# pragma GCC diagnostic ignored "-Wuseless-cast"
#endif
    server_address.sin_addr.s_addr = htonl(INADDR_ANY);
    server_address.sin_port = htons(port);
#pragma GCC diagnostic pop

    if (fd.bind(reinterpret_cast<struct sockaddr *>(&server_address),
              sizeof(server_address)) == -1)
    {
        perror("bind");
        exit(1);
    }
    if (fd.listen(5) == -1)
    {                           /* error */
        perror("listen");
        exit(1);
    }

    readfds.set(fd);

    set_session(fd, make_unique<Session>(
                SessionIO{func_recv: connect_client, func_send: nullptr},
                SessionParsers{func_parse: nullptr, func_delete: nothing_delete}));
    Session *s = get_session(fd);
    s->for_inferior = inferior;
    s->fd = fd;

    s->created = TimeT::now();
    s->connected = 1;

    return s;
}

Session *make_connection(IP4Address ip, uint16_t port, SessionParsers parsers)
{
    struct sockaddr_in server_address;
    io::FD fd = io::FD::socket(AF_INET, SOCK_STREAM, 0);
    if (fd == io::FD())
    {
        perror("socket");
        return nullptr;
    }
    if (fd_max <= fd.uncast_dammit())
        fd_max = fd.uncast_dammit() + 1;

    const int yes = 1;
    /// Allow to bind() again after the server restarts.
    // Since the socket is still in the TIME_WAIT, there's a possibility
    // that formerly lost packets might be delivered and confuse the server.
    fd.setsockopt(SOL_SOCKET, SO_REUSEADDR, &yes, sizeof yes);
    /// Send packets as soon as possible
    /// even if the kernel thinks there is too little for it to be worth it!
    // I'm not convinced this is a good idea; although in minimizes the
    // latency for an individual write, it increases traffic in general.
    fd.setsockopt(IPPROTO_TCP, TCP_NODELAY, &yes, sizeof yes);

    server_address.sin_family = AF_INET;
    server_address.sin_addr = in_addr(ip);
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wold-style-cast"
#if __GNUC__ > 4 || __GNUC_MINOR__ >= 8
# pragma GCC diagnostic ignored "-Wuseless-cast"
#endif
    server_address.sin_port = htons(port);
#pragma GCC diagnostic pop

    fd.fcntl(F_SETFL, O_NONBLOCK);

    /// Errors not caught - we must not block
    /// Let the main select() loop detect when we know the state
    fd.connect(reinterpret_cast<struct sockaddr *>(&server_address),
             sizeof(struct sockaddr_in));

    readfds.set(fd);

    set_session(fd, make_unique<Session>(
                SessionIO{func_recv: recv_to_fifo, func_send: send_from_fifo},
                parsers));
    Session *s = get_session(fd);
    s->fd = fd;
    s->rdata.new_(RFIFO_SIZE);
    s->wdata.new_(WFIFO_SIZE);

    s->max_rdata = RFIFO_SIZE;
    s->max_wdata = WFIFO_SIZE;
    s->created = TimeT::now();
    s->connected = 1;

    return s;
}

void delete_session(Session *s)
{
    if (!s)
        return;
    // this needs to be before the fd_max--
    s->func_delete(s);

    io::FD fd = s->fd;
    // If this was the highest fd, decrease it
    // We could add a loop to decrement fd_max further for every null session,
    // but this is cheap and good enough for the typical case
    if (fd.uncast_dammit() == fd_max - 1)
        fd_max--;
    readfds.clr(fd);
    {
        s->rdata.delete_();
        s->wdata.delete_();
        s->session_data.reset();
        reset_session(fd);
    }

    // just close() would try to keep sending buffers
    fd.shutdown(SHUT_RDWR);
    fd.close();
}

void realloc_fifo(Session *s, size_t rfifo_size, size_t wfifo_size)
{
    if (s->max_rdata != rfifo_size && s->rdata_size < rfifo_size)
    {
        s->rdata.resize(rfifo_size);
        s->max_rdata = rfifo_size;
    }
    if (s->max_wdata != wfifo_size && s->wdata_size < wfifo_size)
    {
        s->wdata.resize(wfifo_size);
        s->max_wdata = wfifo_size;
    }
}

void WFIFOSET(Session *s, size_t len)
{
    if (s->wdata_size + len + 16384 > s->max_wdata)
    {
        realloc_fifo(s, s->max_rdata, s->max_wdata << 1);
        PRINTF("socket: %d wdata expanded to %zu bytes.\n"_fmt, s, s->max_wdata);
    }
    if (s->wdata_size + len + 2048 < s->max_wdata)
        s->wdata_size += len;
    else
        FPRINTF(stderr, "socket: %d wdata lost !!\n"_fmt, s), abort();
}

void do_sendrecv(interval_t next_ms)
{
    bool any = false;
    io::FD_Set rfd = readfds, wfd;
    for (io::FD i : iter_fds())
    {
        Session *s = get_session(i);
        if (s)
        {
            any = true;
            if (s->wdata_size)
                wfd.set(i);
        }
    }
    if (!any)
    {
        if (!has_timers())
        {
            PRINTF("Shutting down - nothing to do\n"_fmt);
            runflag = false;
        }
        return;
    }
    struct timeval timeout;
    {
        std::chrono::seconds next_s = std::chrono::duration_cast<std::chrono::seconds>(next_ms);
        std::chrono::microseconds next_us = next_ms - next_s;
        timeout.tv_sec = next_s.count();
        timeout.tv_usec = next_us.count();
    }
    if (io::FD_Set::select(fd_max, &rfd, &wfd, NULL, &timeout) <= 0)
        return;
    for (io::FD i : iter_fds())
    {
        Session *s = get_session(i);
        if (!s)
            continue;
        if (wfd.isset(i) && !s->eof)
        {
            if (s->func_send)
                //send_from_fifo(i);
                s->func_send(s);
        }
        if (rfd.isset(i) && !s->eof)
        {
            if (s->func_recv)
                //recv_to_fifo(i);
                //or connect_client(i);
                s->func_recv(s);
        }
    }
}

void do_parsepacket(void)
{
    for (io::FD i : iter_fds())
    {
        Session *s = get_session(i);
        if (!s)
            continue;
        if (!s->connected
            && static_cast<time_t>(TimeT::now()) - static_cast<time_t>(s->created) > CONNECT_TIMEOUT)
        {
            PRINTF("Session #%d timed out\n"_fmt, s);
            s->set_eof();
        }
        if (s->rdata_size && !s->eof && s->func_parse)
        {
            s->func_parse(s);
            /// some func_parse may call delete_session
            // (that's kind of evil)
            s = get_session(i);
            if (!s)
                continue;
        }
        if (s->eof)
        {
            delete_session(s);
            continue;
        }
        /// Reclaim buffer space for what was read
        RFIFOFLUSH(s);
    }
}

void RFIFOSKIP(Session *s, size_t len)
{
    s->rdata_pos += len;

    if (s->rdata_size < s->rdata_pos)
    {
        FPRINTF(stderr, "too many skip\n"_fmt);
        abort();
    }
}