1 /* Copyright (C) Doom 2D: Forever Developers
3 * This program is free software: you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation, version 3 of the License ONLY.
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
12 * You should have received a copy of the GNU General Public License
13 * along with this program. If not, see <http://www.gnu.org/licenses/>.
27 #include <enet/enet.h>
28 #include <enet/types.h>
30 #define MS_VERSION "0.3"
31 #define MS_MAX_SERVERS 128
32 #define MS_MAX_CLIENTS (MS_MAX_SERVERS + 1)
33 #define MS_URGENT_FILE "urgent.txt"
34 #define MS_MOTD_FILE "motd.txt"
35 #define MS_BAN_FILE "master_bans.txt"
37 #define DEFAULT_SPAM_CAP 10
38 #define DEFAULT_MAX_SERVERS MS_MAX_SERVERS
39 #define DEFAULT_MAX_PER_HOST 4
40 #define DEFAULT_SERVER_TIMEOUT 100
41 #define DEFAULT_CLIENT_TIMEOUT 3
42 #define DEFAULT_SPAM_TIMEOUT 1
43 #define DEFAULT_PORT 25665
45 #define NET_BUFSIZE 65536
46 #define NET_FULLMASK 0xFFFFFFFF
48 #define SV_PROTO_MIN 140
49 #define SV_PROTO_MAX 210
50 #define SV_NAME_MAX 64
52 #define SV_MAX_PLAYERS 24
53 #define SV_MAX_GAMEMODE 5
54 #define SV_NEW_SERVER_INTERVAL 3
56 #define MAX_STRLEN 0xFF
77 SV_FL_PASSWORD
= 1 << 0,
78 SV_FL_VERIFIED
= 1 << 1,
79 SV_FL_MAX
= SV_FL_PASSWORD
| SV_FL_VERIFIED
,
82 typedef struct enet_buf_s
{
89 typedef struct ban_record_s
{
94 struct ban_record_s
*next
;
95 struct ban_record_s
*prev
;
98 typedef struct server_s
{
99 enet_uint32 host
; // BE; 0 means this slot is unused
100 enet_uint16 port
; // LE, which is what the game and enet both expect
105 enet_uint8 maxplayers
;
106 char name
[MAX_STRLEN
+ 2];
107 char map
[MAX_STRLEN
+ 2];
110 ENetPeer
*peer
; // who sent this server in
114 static server_t servers
[MS_MAX_SERVERS
];
115 static int max_servers
= DEFAULT_MAX_SERVERS
;
116 static int max_servers_per_host
= DEFAULT_MAX_PER_HOST
;
117 static int num_servers
= 0;
119 // fake servers to show on old versions of the game
120 static const server_t fake_servers
[] = {
122 .name
= "! \xc2\xc0\xd8\xc0 \xca\xce\xcf\xc8\xdf \xc8\xc3\xd0\xdb "
123 "\xd3\xd1\xd2\xc0\xd0\xc5\xcb\xc0! "
124 "\xd1\xca\xc0\xd7\xc0\xc9\xd2\xc5 \xcd\xce\xc2\xd3\xde C "
126 .map
= "! Your game is outdated. "
127 "Get latest version at doom2d.org !",
131 .name
= "! \xcf\xd0\xce\xc1\xd0\xce\xd1\xdcTE \xcf\xce\xd0\xd2\xdb "
132 "25666 \xc8 57133 HA CEPBEPE \xcf\xc5\xd0\xc5\xc4 \xc8\xc3\xd0\xce\xc9 !",
133 .map
= "! Forward ports 25666 and 57133 before hosting !",
137 static const int num_fake_servers
= sizeof(fake_servers
) / sizeof(*fake_servers
);
140 static ban_record_t
*banlist
;
143 static int ms_port
= DEFAULT_PORT
;
144 static int ms_sv_timeout
= DEFAULT_SERVER_TIMEOUT
;
145 static int ms_cl_timeout
= DEFAULT_CLIENT_TIMEOUT
;
146 static int ms_spam_timeout
= DEFAULT_SPAM_TIMEOUT
;
147 static int ms_spam_cap
= DEFAULT_SPAM_CAP
;
148 static char ms_motd
[MAX_STRLEN
+ 1] = "";
149 static char ms_urgent
[MAX_STRLEN
+ 1] = "";
150 static ENetHost
*ms_host
;
153 static enet_uint8 buf_send_data
[NET_BUFSIZE
];
154 static enet_buf_t buf_send
= { .data
= buf_send_data
, .size
= sizeof(buf_send_data
) };
155 static enet_buf_t buf_recv
; // rx data supplied by enet packets
157 // stupid client spam filter
158 static enet_uint32 cl_last_addr
;
159 static time_t cl_last_time
;
160 static int cl_spam_cnt
;
162 /* common utility functions */
164 static char *u_vabuf(void) {
165 static char vabuf
[4][MAX_STRLEN
];
167 char *ret
= vabuf
[idx
++];
168 if (idx
>= 4) idx
= 0;
172 static const char *u_strtime(const time_t t
) {
173 char *buf
= u_vabuf();
174 struct tm
*ptm
= localtime(&t
);
175 strftime(buf
, MAX_STRLEN
- 1, "%d/%m/%y %H:%M:%S", ptm
);
179 static inline const char *u_logprefix(const enum log_severity_e s
) {
181 case LOG_WARN
: return "WARNING: ";
182 case LOG_ERROR
: return "ERROR: ";
187 static void u_log(const enum log_severity_e severity
, const char *fmt
, ...) {
188 printf("[%s] %s", u_strtime(time(NULL
)), u_logprefix(severity
));
196 static void __attribute__((noreturn
)) u_fatal(const char *fmt
, ...) {
197 fprintf(stderr
, "[%s] FATAL ERROR:\n", u_strtime(time(NULL
)));
200 vfprintf(stderr
, fmt
, args
);
202 fprintf(stderr
, "\n");
207 static bool u_strisprint(const char *str
) {
210 for (const char *p
= str
; *p
; ++p
) {
211 // only stuff before space, DEL, NBSP and SHY are considered garbage since we're on 1251
212 if (*p
< 0x20 || *p
== 0x7F || *p
== 0xA0 || *p
== 0xAD)
218 static bool u_strisver(const char *str
) {
221 for (const char *p
= str
; *p
; ++p
) {
222 // version strings consist of 0-9 . and space
223 if (!isdigit(*p
) && *p
!= '.' && *p
!= ' ')
229 static const char *u_iptostr(const enet_uint32 host
) {
230 ENetAddress addr
= { .host
= host
, .port
= 0 };
231 char *buf
= u_vabuf();
232 enet_address_get_host_ip(&addr
, buf
, MAX_STRLEN
- 1);
236 static bool u_readtextfile(const char *fname
, char *buf
, size_t max
) {
237 FILE *f
= fopen(fname
, "r");
238 char *const end
= buf
+ max
- 1;
242 char *const lend
= ln
+ max
- 1;
243 while (p
< end
&& fgets(ln
, max
, f
)) {
244 for (char *n
= ln
; n
< lend
&& *n
&& *n
!= '\r' && *n
!= '\n'; ++n
) {
256 static inline enet_uint32
u_prefixtomask(const enet_uint32 prefix
) {
257 return ENET_HOST_TO_NET_32((0xFFFFFFFF << (32 - prefix
)) & 0xFFFFFFFF);
260 static inline enet_uint32
u_masktoprefix(const enet_uint32 mask
) {
261 return (32 - __builtin_ctz(mask
));
264 static inline void u_printsv(const server_t
*sv
) {
265 printf("* addr: %s:%d\n", u_iptostr(sv
->host
), sv
->port
);
266 printf("* name: %s\n", sv
->name
);
267 printf("* map: %s (mode %d)\n", sv
->map
, sv
->gamemode
);
268 printf("* plrs: %d/%d\n", sv
->players
, sv
->maxplayers
);
269 printf("* flag: %04x\n", sv
->flags
);
272 /* buffer utility functions */
274 static inline int b_enough_left(enet_buf_t
*buf
, size_t size
) {
275 if (buf
->pos
+ size
> buf
->size
) {
282 static enet_uint8
b_read_uint8(enet_buf_t
*buf
) {
283 if (b_enough_left(buf
, 1))
284 return buf
->data
[buf
->pos
++];
288 static enet_uint16
b_read_uint16(enet_buf_t
*buf
) {
291 if (b_enough_left(buf
, sizeof(ret
))) {
292 ret
= *(enet_uint16
*)(buf
->data
+ buf
->pos
);
293 buf
->pos
+= sizeof(ret
);
299 static char *b_read_dstring(enet_buf_t
*buf
) {
302 if (b_enough_left(buf
, 1)) {
303 const size_t len
= b_read_uint8(buf
);
304 if (b_enough_left(buf
, len
)) {
305 ret
= malloc(len
+ 1);
306 memmove(ret
, (char*)(buf
->data
+ buf
->pos
), len
);
315 static char *b_read_dstring_to(enet_buf_t
*buf
, char *out
, size_t out_size
) {
316 if (b_enough_left(buf
, 1)) {
317 const size_t len
= b_read_uint8(buf
);
318 if (b_enough_left(buf
, len
)) {
319 if (len
< out_size
) {
320 memmove(out
, (char*)(buf
->data
+ buf
->pos
), len
);
322 } else if (out_size
) {
332 static void b_write_uint8(enet_buf_t
*buf
, enet_uint8 val
) {
333 buf
->data
[buf
->pos
++] = val
;
336 static void b_write_uint16(enet_buf_t
*buf
, enet_uint16 val
) {
337 *(enet_uint16
*)(buf
->data
+ buf
->pos
) = val
;
338 buf
->pos
+= sizeof(val
);
341 static void b_write_dstring(enet_buf_t
*buf
, const char* val
) {
342 enet_uint8 len
= strlen(val
);
343 b_write_uint8(buf
, len
);
344 memmove((char*)(buf
->data
+ buf
->pos
), val
, len
);
348 void b_write_server(enet_buf_t
*buf
, const server_t
*s
) {
349 b_write_dstring(buf
, u_iptostr(s
->host
));
350 b_write_uint16 (buf
, s
->port
);
351 b_write_dstring(buf
, s
->name
);
352 b_write_dstring(buf
, s
->map
);
353 b_write_uint8 (buf
, s
->gamemode
);
354 b_write_uint8 (buf
, s
->players
);
355 b_write_uint8 (buf
, s
->maxplayers
);
356 b_write_uint8 (buf
, s
->proto
);
357 b_write_uint8 (buf
, (s
->flags
& SV_FL_PASSWORD
));
360 /* server functions */
362 static inline void sv_remove(server_t
*sv
) {
364 // drop the associated peer, if any
365 if (sv
->peer
&& sv
->peer
->state
== ENET_PEER_STATE_CONNECTED
&& sv
->peer
->data
== sv
) {
366 sv
->peer
->data
= NULL
;
367 enet_peer_reset(sv
->peer
);
376 static void sv_remove_by_addr(const enet_uint32 host
, const enet_uint16 port
) {
377 for (int i
= 0; i
< max_servers
; ++i
) {
378 if (servers
[i
].host
== host
&& servers
[i
].port
== port
)
379 sv_remove(servers
+ i
);
383 static void sv_remove_by_host(enet_uint32 host
, enet_uint32 mask
) {
385 for (int i
= 0; i
< max_servers
; ++i
) {
386 if (servers
[i
].host
&& (servers
[i
].host
& mask
) == host
)
387 sv_remove(servers
+ i
);
391 static int sv_count_by_host(enet_uint32 host
, enet_uint32 mask
) {
394 for (int i
= 0; i
< max_servers
; ++i
) {
395 if (servers
[i
].host
&& (servers
[i
].host
& mask
) == host
)
401 static time_t sv_last_timestamp_for_host(enet_uint32 host
, enet_uint32 mask
) {
404 for (int i
= 0; i
< max_servers
; ++i
) {
405 if (servers
[i
].host
&& (servers
[i
].host
& mask
) == host
) {
406 if (servers
[i
].timestamp
> last
)
407 last
= servers
[i
].timestamp
;
413 static inline server_t
*sv_find_or_add(const enet_uint32 host
, const enet_uint32 port
) {
414 server_t
*empty
= NULL
;
415 for (int i
= 0; i
< max_servers
; ++i
) {
416 server_t
*s
= servers
+ i
;
417 if (s
->host
== host
&& s
->port
== port
)
418 return s
; // this server already exists
419 if (!s
->host
&& !empty
)
420 empty
= s
; // remember the first empty slot in case it's needed later
425 static inline void sv_clear_peer(ENetPeer
*peer
) {
426 server_t
*sv
= peer
->data
;
433 /* ban list functions */
435 static inline time_t ban_get_time(const int cnt
) {
436 static const time_t times
[] = {
446 static const size_t numtimes
= sizeof(times
) / sizeof(*times
);
448 if (cnt
>= numtimes
|| cnt
< 0)
449 return times
[numtimes
- 1];
454 static ban_record_t
*ban_check(const enet_uint32 host
) {
455 const time_t now
= time(NULL
);
457 for (ban_record_t
*b
= banlist
; b
; b
= b
->next
) {
458 if ((b
->host
& b
->mask
) == (host
& b
->mask
)) {
459 if (b
->cur_ban
> now
)
467 static inline ban_record_t
*ban_record_check(const enet_uint32 host
) {
468 for (ban_record_t
*b
= banlist
; b
; b
= b
->next
) {
469 if ((b
->host
& b
->mask
) == (host
& b
->mask
))
475 static ban_record_t
*ban_record_add_addr(const enet_uint32 host
, const enet_uint32 mask
, const int cnt
, const time_t cur
) {
476 ban_record_t
*rec
= ban_record_check(host
);
479 rec
= calloc(1, sizeof(*rec
));
480 if (!rec
) return NULL
;
482 rec
->host
= host
& mask
;
484 if (rec
->mask
== 0) rec
->mask
= NET_FULLMASK
;
485 rec
->ban_count
= cnt
;
488 if (banlist
) banlist
->prev
= rec
;
495 static ban_record_t
*ban_record_add_ip(const char *ip
, const int cnt
, const time_t cur
) {
496 enet_uint32 prefix
= 32;
498 // find and get the prefix length, if any
499 char ip_copy
[24] = { 0 };
500 strncpy(ip_copy
, ip
, sizeof(ip_copy
) - 1);
501 char *slash
= strrchr(ip_copy
, '/');
503 *slash
++ = '\0'; // strip the prefix length off
504 if (*slash
) prefix
= atoi(slash
);
507 ENetAddress addr
= { 0 };
508 if (enet_address_set_host_ip(&addr
, ip_copy
) != 0) {
509 u_log(LOG_ERROR
, "banlist: `%s` is not a valid IP address", ip_copy
);
513 // transform prefix length into mask
514 const enet_uint32 mask
= u_prefixtomask(prefix
);
516 return ban_record_add_addr(addr
.host
, mask
, cnt
, cur
);
519 static void ban_free_list(void) {
520 ban_record_t
*rec
= banlist
;
522 ban_record_t
*next
= rec
->next
;
529 static void ban_load_list(const char *fname
) {
530 FILE *f
= fopen(fname
, "r");
532 u_log(LOG_WARN
, "banlist: could not open %s for reading", fname
);
536 char ln
[MAX_STRLEN
] = { 0 };
538 while (fgets(ln
, sizeof(ln
), f
)) {
539 for (int i
= sizeof(ln
) - 1; i
>= 0; --i
)
540 if (ln
[i
] == '\n' || ln
[i
] == '\r')
546 char ip
[21] = { 0 }; // optionally includes the "/nn" prefix length at the end
549 if (sscanf(ln
, "%20s %ld %d", ip
, &exp
, &count
) < 3) {
550 u_log(LOG_ERROR
, "banlist: malformed line: `%s`", ln
);
554 if (ban_record_add_ip(ip
, count
, exp
))
555 u_log(LOG_NOTE
, "banlist: banned %s until %s (ban level %d)", ip
, u_strtime(exp
), count
);
561 static void ban_save_list(const char *fname
) {
562 FILE *f
= fopen(fname
, "w");
564 u_log(LOG_ERROR
, "banlist: could not open %s for writing", fname
);
568 for (ban_record_t
*rec
= banlist
; rec
; rec
= rec
->next
) {
570 fprintf(f
, "%s/%u %ld %d\n", u_iptostr(rec
->host
), u_masktoprefix(rec
->mask
), rec
->cur_ban
, rec
->ban_count
);
576 static bool ban_sanity_check(const server_t
*srv
) {
577 // can't have more than 24 maxplayers; can't have more than max
578 if (srv
->players
> srv
->maxplayers
|| srv
->maxplayers
> SV_MAX_PLAYERS
|| srv
->maxplayers
== 0)
580 // name and map have to be non-garbage
581 if (!u_strisprint(srv
->map
) || !u_strisprint(srv
->name
))
583 // these protocols don't exist
584 if (srv
->proto
< SV_PROTO_MIN
|| srv
->proto
> SV_PROTO_MAX
)
586 // the game doesn't allow server names longer than 64 chars
587 if (strlen(srv
->name
) > SV_NAME_MAX
)
589 // game mode has to actually exist
590 if (srv
->gamemode
> SV_MAX_GAMEMODE
)
592 // flags field can't be higher than the sum of all the flags
593 if (srv
->flags
> SV_FL_MAX
)
598 static void ban_add(const enet_uint32 host
, const char *reason
) {
599 const time_t now
= time(NULL
);
601 ban_record_t
*rec
= ban_record_add_addr(host
, NET_FULLMASK
, 0, 0);
602 if (!rec
) u_fatal("OOM trying to ban %s", u_iptostr(host
));
604 rec
->cur_ban
= now
+ ban_get_time(rec
->ban_count
);
607 u_log(LOG_NOTE
, "banned %s until %s, reason: %s, ban level: %d", u_iptostr(rec
->host
), u_strtime(rec
->cur_ban
), reason
, rec
->ban_count
);
609 ban_save_list(MS_BAN_FILE
);
611 sv_remove_by_host(host
, NET_FULLMASK
);
613 if (host
== cl_last_addr
)
617 static inline void ban_peer(ENetPeer
*peer
, const char *reason
) {
619 ban_add(peer
->address
.host
, reason
);
621 enet_peer_reset(peer
);
627 static void deinit(void) {
628 // ban_save_list(MS_BAN_FILE);
631 enet_host_destroy(ms_host
);
638 static void sigusr_handler(int signum
) {
639 if (signum
== SIGUSR1
) {
640 u_log(LOG_WARN
, "received SIGUSR1, reloading banlist");
642 ban_load_list(MS_BAN_FILE
);
647 static bool handle_msg(const enet_uint8 msgid
, ENetPeer
*peer
) {
649 server_t tmpsv
= { 0 };
650 char clientver
[MAX_STRLEN
] = { 0 };
651 const time_t now
= time(NULL
);
655 tmpsv
.port
= b_read_uint16(&buf_recv
);
656 b_read_dstring_to(&buf_recv
, tmpsv
.name
, sizeof(tmpsv
.name
));
657 b_read_dstring_to(&buf_recv
, tmpsv
.map
, sizeof(tmpsv
.map
));
658 tmpsv
.gamemode
= b_read_uint8(&buf_recv
);
659 tmpsv
.players
= b_read_uint8(&buf_recv
);
660 tmpsv
.maxplayers
= b_read_uint8(&buf_recv
);
661 tmpsv
.proto
= b_read_uint8(&buf_recv
);
662 tmpsv
.flags
= b_read_uint8(&buf_recv
);
664 if (buf_recv
.overflow
) {
665 ban_peer(peer
, "malformed MSG_ADD");
669 sv
= sv_find_or_add(peer
->address
.host
, tmpsv
.port
);
671 u_log(LOG_ERROR
, "ran out of server slots trying to add %s:%d", u_iptostr(peer
->address
.host
), tmpsv
.port
);
675 if (sv
->host
== peer
->address
.host
) {
676 // old server; update it
677 memcpy(sv
->map
, tmpsv
.map
, sizeof(sv
->map
));
678 memcpy(sv
->name
, tmpsv
.name
, sizeof(sv
->name
));
679 sv
->players
= tmpsv
.players
;
680 sv
->maxplayers
= tmpsv
.maxplayers
;
681 sv
->flags
= tmpsv
.flags
;
682 sv
->gamemode
= tmpsv
.gamemode
;
683 // first check if the new values are garbage
684 if (!ban_sanity_check(sv
)) {
685 ban_peer(peer
, "tripped sanity check");
688 // only then update the times
689 sv
->death_time
= now
+ ms_sv_timeout
;
691 // check if we're updating from a new peer
692 if (sv
->peer
!= peer
) {
693 // if there was an old one, kill it
695 sv
->peer
->data
= NULL
;
696 enet_peer_reset(sv
->peer
);
701 u_log(LOG_NOTE
, "updated server #%d:", sv
- servers
);
704 // new server; first check if this host is creating too many servers in the list
705 if (max_servers_per_host
) {
706 const int count
= sv_count_by_host(peer
->address
.host
, NET_FULLMASK
);
707 if (count
>= max_servers_per_host
) {
708 ban_peer(peer
, "too many servers in list");
712 // FIXME: commented out as this might trip when the master restarts
714 // check if this is too soon to create a new server
715 const time_t delta = now - sv_last_timestamp_for_host(peer->address.host, NET_FULLMASK);
716 if (delta < count * SV_NEW_SERVER_INTERVAL) {
717 ban_peer(peer, "creating servers too fast");
723 // then add that shit
725 sv
->host
= peer
->address
.host
;
726 sv
->death_time
= now
+ ms_sv_timeout
;
728 if (!ban_sanity_check(sv
)) {
731 ban_peer(peer
, "tripped sanity check");
737 u_log(LOG_NOTE
, "added new server #%d:", sv
- servers
);
743 tmpsv
.port
= b_read_uint16(&buf_recv
);
744 if (buf_recv
.overflow
) {
745 ban_peer(peer
, "malformed MSG_RM");
748 sv_remove_by_addr(peer
->address
.host
, tmpsv
.port
);
749 // this peer can be disconnected pretty much immediately since he has no servers left, tell him to fuck off
751 enet_peer_disconnect_later(peer
, 0);
756 buf_send
.overflow
= 0;
757 b_write_uint8(&buf_send
, NET_MSG_LIST
);
760 if (buf_recv
.size
> 2) {
761 // holy shit a fresh client
762 b_read_dstring_to(&buf_recv
, clientver
, sizeof(clientver
));
763 b_write_uint8(&buf_send
, num_servers
);
765 // old client; feed him fake servers first
766 b_write_uint8(&buf_send
, num_servers
+ num_fake_servers
);
767 for (int i
= 0; i
< num_fake_servers
; ++i
)
768 b_write_server(&buf_send
, &fake_servers
[i
]);
771 if (buf_recv
.overflow
) {
772 ban_peer(peer
, "malformed MSG_LIST");
776 if (clientver
[0] && !u_strisver(clientver
)) {
777 ban_peer(peer
, "malformed MSG_LIST clientver");
781 for (int i
= 0; i
< max_servers
; ++i
) {
783 b_write_server(&buf_send
, servers
+ i
);
787 // TODO: check if this client is outdated (?) and send back new verstring
788 // for now just write the same shit back
789 b_write_dstring(&buf_send
, clientver
);
790 // write the motd and urgent message
791 b_write_dstring(&buf_send
, ms_motd
);
792 b_write_dstring(&buf_send
, ms_urgent
);
795 ENetPacket
*p
= enet_packet_create(buf_send
.data
, buf_send
.pos
, ENET_PACKET_FLAG_RELIABLE
);
796 enet_peer_send(peer
, NET_CH_MAIN
, p
);
797 // enet_host_flush(ms_host);
799 // this peer can be disconnected pretty much immediately after receiving the server list, tell him to fuck off
801 enet_peer_disconnect_later(peer
, 0);
803 u_log(LOG_NOTE
, "sent server list to %s:%d (ver %s)", u_iptostr(peer
->address
.host
), peer
->address
.port
, clientver
[0] ? clientver
: "<old>");
813 static void print_usage(void) {
814 printf("Usage: d2df_master [OPTIONS...]\n");
815 printf("Available options:\n");
816 printf("-h show this message and exit\n");
817 printf("-p N listen on port N (default: %d)\n", DEFAULT_PORT
);
818 printf("-t N seconds before server is removed from list (default: %d)\n", DEFAULT_SERVER_TIMEOUT
);
819 printf("-c N how long a client is allowed to hold the connection active (default: %d)\n", DEFAULT_CLIENT_TIMEOUT
);
820 printf("-s N max number of servers in server list, 1-%d (default: %d)\n", MS_MAX_SERVERS
, DEFAULT_MAX_SERVERS
);
821 printf("-d N if N > 0, disallow more than N servers on the same IP (default: %d)\n", DEFAULT_MAX_PER_HOST
);
822 printf("-f N crappy spam filter: ban clients after they send N requests in a row too fast (default: %d)\n", DEFAULT_SPAM_CAP
);
823 printf("-w N how often does a client have to send packets for the filter to kick in, i.e. once every N sec (default: %d)\n", DEFAULT_SPAM_TIMEOUT
);
827 static inline bool parse_int_arg(int argc
, char **argv
, const int i
, const char *name
, int vmin
, int vmax
, int *outval
) {
828 if (strcmp(name
, argv
[i
]))
832 fprintf(stderr
, "expected integer value after %s\n", name
);
836 const int v
= atoi(argv
[i
+ 1]);
837 if (v
< vmin
|| v
> vmax
) {
838 fprintf(stderr
, "expected integer value in range %d - %d\n", vmin
, vmax
);
846 static bool parse_args(int argc
, char **argv
) {
850 if (!strcmp(argv
[1], "-h")) {
855 for (int i
= 1; i
< argc
; ++i
) {
857 parse_int_arg(argc
, argv
, i
, "-p", 1, 0xFFFF, &ms_port
)
858 || parse_int_arg(argc
, argv
, i
, "-t", 1, 0x7FFFFFFF, &ms_sv_timeout
)
859 || parse_int_arg(argc
, argv
, i
, "-c", 1, 0x7FFFFFFF, &ms_cl_timeout
)
860 || parse_int_arg(argc
, argv
, i
, "-s", 1, MS_MAX_SERVERS
, &max_servers
)
861 || parse_int_arg(argc
, argv
, i
, "-d", 0, MS_MAX_SERVERS
, &max_servers_per_host
)
862 || parse_int_arg(argc
, argv
, i
, "-f", 0, 0xFFFF, &ms_spam_cap
)
863 || parse_int_arg(argc
, argv
, i
, "-w", 1, 0x7FFFFFFF, &ms_spam_timeout
);
867 fprintf(stderr
, "unknown or invalid argument: %s\n", argv
[i
]);
875 // a stupid thing to filter sustained spam from a single IP
876 static bool spam_filter(ENetPeer
*peer
, const time_t now
) {
877 if (peer
->address
.host
== cl_last_addr
) {
878 // spam === sending shit faster than once a second
879 if (now
- cl_last_time
< ms_spam_timeout
) {
881 u_log(LOG_WARN
, "address %s is sending packets too fast", u_iptostr(peer
->address
.host
));
882 if (++cl_spam_cnt
>= ms_spam_cap
) {
883 ban_peer(peer
, "spam");
891 cl_last_addr
= peer
->address
.host
;
898 // filter incoming UDP packets before the protocol kicks in
899 static int packet_filter(ENetHost
*host
, ENetEvent
*event
) {
900 return !!ban_check(host
->receivedAddress
.host
);
903 int main(int argc
, char **argv
) {
904 if (enet_initialize() != 0)
905 u_fatal("could not init enet");
907 if (!parse_args(argc
, argv
))
908 return 1; // early exit
910 u_log(LOG_NOTE
, "d2df master server starting on port %d", ms_port
);
912 if (!u_readtextfile(MS_MOTD_FILE
, ms_motd
, sizeof(ms_motd
)))
913 u_log(LOG_NOTE
, "couldn't read motd from %s", MS_MOTD_FILE
);
915 u_log(LOG_NOTE
, "motd: %s", ms_motd
);
917 if (!u_readtextfile(MS_URGENT_FILE
, ms_urgent
, sizeof(ms_urgent
)))
918 u_log(LOG_NOTE
, "couldn't read urgentmsg from %s", MS_URGENT_FILE
);
920 u_log(LOG_NOTE
, "urgentmsg: %s", ms_urgent
);
922 ban_load_list(MS_BAN_FILE
);
927 signal(SIGUSR1
, sigusr_handler
);
933 ms_host
= enet_host_create(&addr
, MS_MAX_CLIENTS
, NET_CH_COUNT
+ 1, 0, 0);
935 u_fatal("could not create enet host on port %d", ms_port
);
937 ms_host
->intercept
= packet_filter
;
940 enet_uint8 msgid
= 0;
943 while (enet_host_service(ms_host
, &event
, 10) > 0) {
944 const time_t now
= time(NULL
);
945 const bool filtered
= !event
.peer
|| (ms_spam_cap
&& spam_filter(event
.peer
, now
));
948 switch (event
.type
) {
949 case ENET_EVENT_TYPE_CONNECT
:
950 u_log(LOG_NOTE
, "%s:%d connected", u_iptostr(event
.peer
->address
.host
), event
.peer
->address
.port
);
951 if (event
.peer
->channelCount
!= NET_CH_COUNT
)
952 ban_peer(event
.peer
, "what is this");
954 enet_peer_timeout(event
.peer
, 0, 0, ms_cl_timeout
* 1000);
957 case ENET_EVENT_TYPE_RECEIVE
:
958 if (!event
.packet
|| event
.packet
->dataLength
== 0) {
959 ban_peer(event
.peer
, "empty packet");
962 // set up receive buffer
964 buf_recv
.overflow
= 0;
965 buf_recv
.data
= event
.packet
->data
;
966 buf_recv
.size
= event
.packet
->dataLength
;
967 // read message id and handle the message
968 msgid
= b_read_uint8(&buf_recv
);
969 if (!handle_msg(msgid
, event
.peer
)) {
970 // cheeky cunt sending invalid messages
971 ban_peer(event
.peer
, "unknown message");
975 case ENET_EVENT_TYPE_DISCONNECT
:
977 // u_log(LOG_NOTE, "%s:%d disconnected", u_iptostr(event.peer->address.host), event.peer->address.port);
983 } else if (event
.peer
) {
984 // u_log(LOG_WARN, "filtered event %d from %s", event.type, u_iptostr(event.peer->address.host));
985 sv_clear_peer(event
.peer
);
986 enet_peer_reset(event
.peer
);
990 buf_recv
.data
= NULL
;
991 enet_packet_destroy(event
.packet
);
995 const time_t now
= time(NULL
);
998 for (int i
= 0; i
< max_servers
; ++i
) {
999 if (servers
[i
].host
&& servers
[i
].death_time
<= now
) {
1000 u_log(LOG_NOTE
, "server #%d %s:%d timed out", i
, u_iptostr(servers
[i
].host
), servers
[i
].port
);
1001 sv_remove(servers
+ i
);