diff options
Diffstat (limited to 'src/common/socket.c')
| -rw-r--r-- | src/common/socket.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/src/common/socket.c b/src/common/socket.c index deba0e97b..89c605c9d 100644 --- a/src/common/socket.c +++ b/src/common/socket.c @@ -199,6 +199,10 @@ time_t stall_time = 60; uint32 addr_[16]; // ip addresses of local host (host byte order) int naddr_ = 0; // # of ip addresses +// Maximum packet size in bytes, which the client is able to handle. +// Larger packets cause a buffer overflow and stack corruption. +static size_t socket_max_client_packet = 20480; + // initial recv buffer size (this will also be the max. size) // biggest known packet: S 0153 <len>.w <emblem data>.?B -> 24x24 256 color .bmp (0153 + len.w + 1618/1654/1756 bytes) #define RFIFO_SIZE (2*1024) @@ -643,8 +647,15 @@ int WFIFOSET(int fd, size_t len) exit(EXIT_FAILURE); } + if( !s->flag.server && len > socket_max_client_packet ) + {// see declaration of socket_max_client_packet for details + ShowError("WFIFOSET: Dropped too large client packet 0x%04x (length=%u, max=%u).\n", WFIFOW(fd,0), len, socket_max_client_packet); + return 0; + } + if( !s->flag.server && s->wdata_size+len > WFIFO_MAX ) {// reached maximum write fifo size + ShowError("WFIFOSET: Maximum write buffer size for client connection %d exceeded, most likely caused by packet 0x%04x (len=%u, ip=%lu.%lu.%lu.%lu).\n", fd, WFIFOW(fd,0), len, CONVIP(s->client_addr)); set_eof(fd); return 0; } @@ -1064,6 +1075,8 @@ int socket_config_read(const char* cfgName) ddos_autoreset = atoi(w2); else if (!strcmpi(w1,"debug")) access_debug = config_switch(w2); + else if (!strcmpi(w1,"socket_max_client_packet")) + socket_max_client_packet = strtoul(w2, NULL, 0); #endif else if (!strcmpi(w1, "import")) socket_config_read(w2); |