diff --git a/src/mastersrv/master.c b/src/mastersrv/master.c
index 2ea5016bbf538ba65ee5da1e0f7679c5610894bf..e27cde1f9e57815cd012a47b20d5390213a47f4f 100644 (file)
--- a/src/mastersrv/master.c
+++ b/src/mastersrv/master.c
#include <ctype.h>
#include <string.h>
#include <time.h>
-#include <errno.h>
+#include <signal.h>
+#define ENET_DEBUG 1
#include <enet/enet.h>
#include <enet/types.h>
#define DEFAULT_SPAM_CAP 10
#define DEFAULT_MAX_SERVERS MS_MAX_SERVERS
#define DEFAULT_MAX_PER_HOST 4
-#define DEFAULT_TIMEOUT 100
-#define DEFAULT_BAN_TIME (3 * 86400)
+#define DEFAULT_SERVER_TIMEOUT 100
+#define DEFAULT_CLIENT_TIMEOUT 3
+#define DEFAULT_SPAM_TIMEOUT 1
#define DEFAULT_PORT 25665
#define NET_BUFSIZE 65536
// settings
static int ms_port = DEFAULT_PORT;
-static int ms_timeout = DEFAULT_TIMEOUT;
+static int ms_sv_timeout = DEFAULT_SERVER_TIMEOUT;
+static int ms_cl_timeout = DEFAULT_CLIENT_TIMEOUT;
+static int ms_spam_timeout = DEFAULT_SPAM_TIMEOUT;
static int ms_spam_cap = DEFAULT_SPAM_CAP;
static char ms_motd[MAX_STRLEN + 1] = "";
static char ms_urgent[MAX_STRLEN + 1] = "";
static inline const char *u_logprefix(const enum log_severity_e s) {
switch (s) {
- case LOG_WARN: return "WARNING:";
- case LOG_ERROR: return "ERROR:";
+ case LOG_WARN: return "WARNING: ";
+ case LOG_ERROR: return "ERROR: ";
default: return "";
}
}
static void u_log(const enum log_severity_e severity, const char *fmt, ...) {
- printf("[%s] %s ", u_strtime(time(NULL)), u_logprefix(severity));
+ printf("[%s] %s", u_strtime(time(NULL)), u_logprefix(severity));
va_list args;
va_start(args, fmt);
vprintf(fmt, args);
return true;
}
+static bool u_strisver(const char *str) {
+ if (!str || !*str)
+ return false;
+ for (const char *p = str; *p; ++p) {
+ // version strings consist of 0-9 . and space
+ if (!isdigit(*p) && *p != '.' && *p != ' ')
+ return false;
+ }
+ return true;
+}
+
static const char *u_iptostr(const enet_uint32 host) {
ENetAddress addr = { .host = host, .port = 0 };
char *buf = u_vabuf();
@@ -469,6 +484,16 @@ static ban_record_t *ban_record_add_ip(const char *ip, const int cnt, const time
return ban_record_add_addr(addr.host, mask, cnt, cur);
}
+static void ban_free_list(void) {
+ ban_record_t *rec = banlist;
+ while (rec) {
+ ban_record_t *next = rec->next;
+ free(rec);
+ rec = next;
+ }
+ banlist = NULL;
+}
+
static void ban_load_list(const char *fname) {
FILE *f = fopen(fname, "r");
if (!f) {
static inline void ban_peer(ENetPeer *peer, const char *reason) {
if (peer) {
ban_add(peer->address.host, reason);
+ peer->data = NULL;
enet_peer_reset(peer);
}
}
static void deinit(void) {
// ban_save_list(MS_BAN_FILE);
+ ban_free_list();
if (ms_host) {
enet_host_destroy(ms_host);
ms_host = NULL;
enet_deinitialize();
}
+#ifdef SIGUSR1
+static void sigusr_handler(int signum) {
+ if (signum == SIGUSR1) {
+ u_log(LOG_WARN, "received SIGUSR1, reloading banlist");
+ ban_free_list();
+ ban_load_list(MS_BAN_FILE);
+ }
+}
+#endif
+
static bool handle_msg(const enet_uint8 msgid, ENetPeer *peer) {
server_t *sv = NULL;
server_t tmpsv = { 0 };
return true;
}
// only then update the times
- sv->death_time = now + ms_timeout;
+ sv->death_time = now + ms_sv_timeout;
sv->timestamp = now;
u_log(LOG_NOTE, "updated server #%d:", sv - servers);
u_printsv(sv);
// then add that shit
*sv = tmpsv;
sv->host = peer->address.host;
- sv->death_time = now + ms_timeout;
+ sv->death_time = now + ms_sv_timeout;
sv->timestamp = now;
if (!ban_sanity_check(sv)) {
sv->host = 0;
case NET_MSG_LIST:
buf_send.pos = 0;
+ buf_send.overflow = 0;
b_write_uint8(&buf_send, NET_MSG_LIST);
clientver[0] = 0;
return true;
}
+ if (clientver[0] && !u_strisver(clientver)) {
+ ban_peer(peer, "malformed MSG_LIST clientver");
+ return true;
+ }
+
for (int i = 0; i < max_servers; ++i) {
if (servers[i].host)
b_write_server(&buf_send, servers + i);
ENetPacket *p = enet_packet_create(buf_send.data, buf_send.pos, ENET_PACKET_FLAG_RELIABLE);
enet_peer_send(peer, NET_CH_MAIN, p);
- enet_host_flush(ms_host);
+ // enet_host_flush(ms_host);
u_log(LOG_NOTE, "sent server list to %s:%d (ver %s)", u_iptostr(peer->address.host), peer->address.port, clientver[0] ? clientver : "<old>");
return true;
printf("Available options:\n");
printf("-h show this message and exit\n");
printf("-p N listen on port N (default: %d)\n", DEFAULT_PORT);
- printf("-t N seconds before server is removed from list (default: %d)\n", DEFAULT_TIMEOUT);
+ printf("-t N seconds before server is removed from list (default: %d)\n", DEFAULT_SERVER_TIMEOUT);
+ printf("-c N how long a client is allowed to hold the connection active (default: %d)\n", DEFAULT_CLIENT_TIMEOUT);
printf("-s N max number of servers in server list, 1-%d (default: %d)\n", MS_MAX_SERVERS, DEFAULT_MAX_SERVERS);
printf("-d N if N > 0, disallow more than N servers on the same IP (default: %d)\n", DEFAULT_MAX_PER_HOST);
- printf("-f N crappy spam filter: ban people after they send N requests in a row too fast (default: %d)\n", DEFAULT_SPAM_CAP);
+ printf("-f N crappy spam filter: ban clients after they send N requests in a row too fast (default: %d)\n", DEFAULT_SPAM_CAP);
+ 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);
fflush(stdout);
}
if (argc < 2)
return true;
- if (!strcmp(argv[0], "-h")) {
+ if (!strcmp(argv[1], "-h")) {
print_usage();
return false;
}
for (int i = 1; i < argc; ++i) {
const bool success =
parse_int_arg(argc, argv, i, "-p", 1, 0xFFFF, &ms_port)
- || parse_int_arg(argc, argv, i, "-t", 1, 0x7FFFFFFF, &ms_timeout)
+ || parse_int_arg(argc, argv, i, "-t", 1, 0x7FFFFFFF, &ms_sv_timeout)
+ || parse_int_arg(argc, argv, i, "-c", 1, 0x7FFFFFFF, &ms_cl_timeout)
|| parse_int_arg(argc, argv, i, "-s", 1, MS_MAX_SERVERS, &max_servers)
|| parse_int_arg(argc, argv, i, "-d", 0, MS_MAX_SERVERS, &max_servers_per_host)
- || parse_int_arg(argc, argv, i, "-f", 0, 0xFFFF, &ms_spam_cap);
+ || parse_int_arg(argc, argv, i, "-f", 0, 0xFFFF, &ms_spam_cap)
+ || parse_int_arg(argc, argv, i, "-w", 1, 0x7FFFFFFF, &ms_spam_timeout);
if (success) {
++i;
} else {
}
// a stupid thing to filter sustained spam from a single IP
-static bool spam_filter(ENetPeer *peer) {
- const time_t now = time(NULL);
+static bool spam_filter(ENetPeer *peer, const time_t now) {
if (peer->address.host == cl_last_addr) {
// spam === sending shit faster than once a second
- if (now - cl_last_time < 1) {
+ if (now - cl_last_time < ms_spam_timeout) {
if (cl_spam_cnt > 1)
u_log(LOG_WARN, "address %s is sending packets too fast", u_iptostr(peer->address.host));
if (++cl_spam_cnt >= ms_spam_cap) {
ban_peer(peer, "spam");
+ cl_last_addr = 0;
return true;
}
} else {
return false;
}
+// filter incoming UDP packets before the protocol kicks in
+static int packet_filter(ENetHost *host, ENetEvent *event) {
+ return !!ban_check(host->receivedAddress.host);
+}
+
int main(int argc, char **argv) {
if (enet_initialize() != 0)
u_fatal("could not init enet");
atexit(deinit);
+#ifdef SIGUSR1
+ signal(SIGUSR1, sigusr_handler);
+#endif
+
ENetAddress addr;
addr.host = 0;
addr.port = ms_port;
if (!ms_host)
u_fatal("could not create enet host on port %d", ms_port);
+ ms_host->intercept = packet_filter;
+
bool running = true;
enet_uint8 msgid = 0;
ENetEvent event;
while (running) {
- while (enet_host_service(ms_host, &event, 5000) > 0) {
- if (!event.peer) {
- continue; // can this even happen?
- } else if (ban_check(event.peer->address.host)) {
- enet_peer_reset(event.peer);
- continue;
+ while (enet_host_service(ms_host, &event, 10) > 0) {
+ const time_t now = time(NULL);
+ bool filtered = !event.peer || (ms_spam_cap && spam_filter(event.peer, now));
+ if (!filtered && event.peer->data) {
+ // kick people that have overstayed their welcome
+ const time_t timeout = (time_t)(intptr_t)event.peer->data;
+ if (timeout < now) filtered = true;
}
- if (event.type != ENET_EVENT_TYPE_DISCONNECT)
- if (spam_filter(event.peer))
- continue;
+ if (!filtered) {
+ switch (event.type) {
+ case ENET_EVENT_TYPE_CONNECT:
+ u_log(LOG_NOTE, "%s:%d connected", u_iptostr(event.peer->address.host), event.peer->address.port);
+ if (event.peer->channelCount != NET_CH_COUNT)
+ ban_peer(event.peer, "what is this");
+ else // store timeout in the data field
+ event.peer->data = (void *)(intptr_t)(now + ms_cl_timeout);
+ break;
- switch (event.type) {
- case ENET_EVENT_TYPE_CONNECT:
- u_log(LOG_NOTE, "%s:%d connected", u_iptostr(event.peer->address.host), event.peer->address.port);
- break;
+ case ENET_EVENT_TYPE_RECEIVE:
+ if (!event.packet || event.packet->dataLength == 0) {
+ ban_peer(event.peer, "empty packet");
+ break;
+ }
+ // set up receive buffer
+ buf_recv.pos = 0;
+ buf_recv.overflow = 0;
+ buf_recv.data = event.packet->data;
+ buf_recv.size = event.packet->dataLength;
+ // read message id and handle the message
+ msgid = b_read_uint8(&buf_recv);
+ if (!handle_msg(msgid, event.peer)) {
+ // cheeky cunt sending invalid messages
+ ban_peer(event.peer, "unknown message");
+ }
+ break;
- case ENET_EVENT_TYPE_RECEIVE:
- if (!event.packet || event.packet->dataLength == 0) {
- ban_peer(event.peer, "empty packet");
+ case ENET_EVENT_TYPE_DISCONNECT:
+ event.peer->data = NULL;
break;
- }
- // set up receive buffer
- buf_recv.pos = 0;
- buf_recv.overflow = 0;
- buf_recv.data = event.packet->data;
- buf_recv.size = event.packet->dataLength;
- // read message id and handle the message
- msgid = b_read_uint8(&buf_recv);
- if (!handle_msg(msgid, event.peer)) {
- // cheeky cunt sending invalid messages
- ban_peer(event.peer, "unknown message");
- }
- break;
- default:
- break;
+ default:
+ break;
+ }
+ } else if (event.peer) {
+ // u_log(LOG_WARN, "filtered event %d from %s", event.type, u_iptostr(event.peer->address.host));
+ event.peer->data = NULL;
+ enet_peer_reset(event.peer);
+ }
+
+ if (event.packet) {
+ buf_recv.data = NULL;
+ enet_packet_destroy(event.packet);
}
}