/* IPXWrapper - Router code * Copyright (C) 2011 Daniel Collins * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published by * the Free Software Foundation. * * 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, write to the Free Software Foundation, Inc., 51 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include #include #include "router.h" #include "common.h" #include "ipxwrapper.h" #include "interface.h" static struct router_addr *router_get(struct router_vars *router, SOCKET control, SOCKET sock); static BOOL router_handle_call(struct router_vars *router, int sock, struct router_call *call); static void router_drop_client(struct router_vars *router, int coff); static BOOL rclient_do(struct rclient *rclient, struct router_call *call, struct router_ret *ret); /* Allocate router_vars structure and initialise all members * Returns NULL on failure */ struct router_vars *router_init(BOOL global) { struct router_vars *router = malloc(sizeof(struct router_vars)); if(!router) { log_printf("Not enough memory to create router_vars!"); return NULL; } router->running = TRUE; router->interfaces = NULL; router->udp_sock = -1; router->listener = -1; router->client_count = 0; router->wsa_event = WSA_INVALID_EVENT; router->crit_sec_init = FALSE; router->addrs = NULL; router->recvbuf = NULL; if(InitializeCriticalSectionAndSpinCount(&(router->crit_sec), 0x80000000)) { router->crit_sec_init = TRUE; }else{ log_printf("Error creating critical section: %s", w32_error(GetLastError())); router_destroy(router); return NULL; } if((router->wsa_event = WSACreateEvent()) == WSA_INVALID_EVENT) { log_printf("Error creating WSA event object: %s", w32_error(WSAGetLastError())); router_destroy(router); return NULL; } router->interfaces = get_interfaces(-1); if((router->udp_sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { log_printf("Error creating UDP socket: %s", w32_error(WSAGetLastError())); router_destroy(router); return NULL; } struct sockaddr_in addr; addr.sin_family = AF_INET; addr.sin_addr.s_addr = INADDR_ANY; addr.sin_port = htons(global_conf.udp_port); if(bind(router->udp_sock, (struct sockaddr*)&addr, sizeof(addr)) == -1) { log_printf("Error binding UDP socket: %s", w32_error(WSAGetLastError())); router_destroy(router); return NULL; } BOOL broadcast = TRUE; int bufsize = 524288; /* 512KiB */ setsockopt(router->udp_sock, SOL_SOCKET, SO_BROADCAST, (char*)&broadcast, sizeof(BOOL)); setsockopt(router->udp_sock, SOL_SOCKET, SO_RCVBUF, (char*)&bufsize, sizeof(int)); setsockopt(router->udp_sock, SOL_SOCKET, SO_SNDBUF, (char*)&bufsize, sizeof(int)); if(WSAEventSelect(router->udp_sock, router->wsa_event, FD_READ) == -1) { log_printf("WSAEventSelect error: %s", w32_error(WSAGetLastError())); router_destroy(router); return NULL; } if(!(router->recvbuf = malloc(PACKET_BUF_SIZE))) { log_printf("Out of memory! Cannot allocate recv buffer"); router_destroy(router); return NULL; } if(global) { if((router->listener = socket(AF_INET, SOCK_STREAM, 0)) == -1) { log_printf("Failed to create TCP socket: %s", w32_error(WSAGetLastError())); router_destroy(router); return NULL; } /* TODO: Use different port number for control socket? */ addr.sin_addr.s_addr = inet_addr("127.0.0.1"); if(bind(router->listener, (struct sockaddr*)&addr, sizeof(addr)) == -1) { log_printf("Failed to bind TCP socket: %s", w32_error(WSAGetLastError())); router_destroy(router); return NULL; } if(listen(router->listener, 8) == -1) { log_printf("Failed to listen for connections: %s", w32_error(WSAGetLastError())); router_destroy(router); return NULL; } if(WSAEventSelect(router->listener, router->wsa_event, FD_ACCEPT) == -1) { log_printf("WSAEventSelect error: %s", w32_error(WSAGetLastError())); router_destroy(router); return NULL; } } return router; } /* Release all resources allocated by a router and free it */ void router_destroy(struct router_vars *router) { struct router_addr *addr = router->addrs; int i; while(addr) { struct router_addr *del = addr; addr = addr->next; free(del); } for(i = 0; i < router->client_count; i++) { closesocket(router->clients[i].sock); } if(router->listener != -1) { closesocket(router->listener); } free(router->recvbuf); if(router->udp_sock != -1) { closesocket(router->udp_sock); } free_interfaces(router->interfaces); if(router->wsa_event != WSA_INVALID_EVENT) { WSACloseEvent(router->wsa_event); } if(router->crit_sec_init) { DeleteCriticalSection(&(router->crit_sec)); } free(router); } DWORD router_main(void *arg) { struct router_vars *router = arg; const unsigned char f6[] = {0xFF,0xFF,0xFF,0xFF,0xFF,0xFF}; while(1) { WaitForSingleObject(router->wsa_event, INFINITE); EnterCriticalSection(&(router->crit_sec)); WSAResetEvent(router->wsa_event); if(!router->running) { LeaveCriticalSection(&(router->crit_sec)); return 0; } LeaveCriticalSection(&(router->crit_sec)); if(router->listener != -1) { int newfd = accept(router->listener, NULL, NULL); if(newfd != -1) { if(router->client_count == MAX_ROUTER_CLIENTS) { log_printf("Too many clients, dropping new connection!"); goto DROP_NEWFD; } if(WSAEventSelect(newfd, router->wsa_event, FD_READ | FD_CLOSE) == -1) { log_printf("WSAEventSelect error: %s", w32_error(WSAGetLastError())); goto DROP_NEWFD; } router->clients[router->client_count].sock = newfd; router->clients[router->client_count++].recvbuf_len = 0; if(0) { DROP_NEWFD: closesocket(newfd); } }else if(WSAGetLastError() != WSAEWOULDBLOCK) { log_printf("Failed to accept client connection: %s", w32_error(WSAGetLastError())); } } int i; for(i = 0; i < router->client_count; i++) { char *bstart = ((char*)&(router->clients[i].recvbuf)) + router->clients[i].recvbuf_len; int len = sizeof(struct router_call) - router->clients[i].recvbuf_len; if((len = recv(router->clients[i].sock, bstart, len, 0)) == -1) { if(WSAGetLastError() == WSAEWOULDBLOCK) { continue; }else if(WSAGetLastError() == WSAECONNRESET) { /* Treat connection reset as regular close */ len = 0; }else{ log_printf("Error reading from client socket: %s", w32_error(WSAGetLastError())); } } if(len == -1 || len == 0) { router_drop_client(router, i--); continue; } if((router->clients[i].recvbuf_len += len) == sizeof(struct router_call)) { if(router_handle_call(router, router->clients[i].sock, &(router->clients[i].recvbuf))) { router->clients[i].recvbuf_len = 0; }else{ router_drop_client(router, i--); } } } struct sockaddr_in addr; int addrlen = sizeof(addr); int len = recvfrom(router->udp_sock, router->recvbuf, PACKET_BUF_SIZE, 0, (struct sockaddr*)&addr, &addrlen); if(len == -1) { if(WSAGetLastError() == WSAEWOULDBLOCK || WSAGetLastError() == WSAECONNRESET) { continue; } log_printf("Error reading from UDP socket: %s", w32_error(WSAGetLastError())); return 1; } EnterCriticalSection(&(router->crit_sec)); ipx_packet *packet = (ipx_packet*)router->recvbuf; /* Check that the packet arrived from the subnet of an enabled network * interface and drop it if not. */ if(global_conf.filter) { struct ipx_interface *iface = router->interfaces; while(iface) { if((iface->ipaddr & iface->netmask) == (addr.sin_addr.s_addr & iface->netmask)) { break; } iface = iface->next; } if(!iface) { LeaveCriticalSection(&(router->crit_sec)); continue; } } packet->size = ntohs(packet->size); if(packet->size > MAX_PACKET_SIZE || packet->size + sizeof(ipx_packet) - 1 != len) { LeaveCriticalSection(&(router->crit_sec)); continue; } /* Replace destination network field of packet with source IP address * so that the client can cache it. */ char dest_net[4]; memcpy(dest_net, packet->dest_net, 4); memcpy(packet->dest_net, &(addr.sin_addr.s_addr), 4); struct router_addr *ra = router->addrs; while(ra) { if( ra->local_port && (ra->filter_ptype < 0 || ra->filter_ptype == packet->ptype) && (memcmp(dest_net, ra->addr.sa_netnum, 4) == 0 || memcmp(dest_net, f6, 4) == 0) && (memcmp(packet->dest_node, ra->addr.sa_nodenum, 6) == 0 || memcmp(packet->dest_node, f6, 6) == 0) && packet->dest_socket == ra->addr.sa_socket ) { addr.sin_addr.s_addr = inet_addr("127.0.0.1"); addr.sin_port = ra->local_port; if(sendto(router->udp_sock, (char*)packet, len, 0, (struct sockaddr*)&addr, sizeof(addr)) == -1) { log_printf("Error relaying packet: %s", w32_error(WSAGetLastError())); } } ra = ra->next; } LeaveCriticalSection(&(router->crit_sec)); } return 0; } static int router_bind(struct router_vars *router, SOCKET control, SOCKET sock, struct sockaddr_ipx *addr, uint32_t *nic_bcast, BOOL reuse) { /* Network number 00:00:00:00 is specified as the "current" network, this code * treats it as a wildcard when used for the network OR node numbers. * * According to MSDN 6, IPX socket numbers are unique to systems rather than * interfaces and as such, the same socket number cannot be bound to more than * one interface, my code lacks any "catch all" address like INADDR_ANY as I have * not found any mentions of an equivalent address for IPX. This means that a * given socket number may only be used on one interface. * * If you know the above information about IPX socket numbers to be incorrect, * PLEASE email me with corrections! */ struct ipx_interface *ifaces = get_interfaces(-1), *iface; unsigned char z6[] = {0,0,0,0,0,0}; for(iface = ifaces; iface; iface = iface->next) { if( (memcmp(addr->sa_netnum, iface->ipx_net, 4) == 0 || memcmp(addr->sa_netnum, z6, 4) == 0) && (memcmp(addr->sa_nodenum, iface->ipx_node, 6) == 0 || memcmp(addr->sa_nodenum, z6, 6) == 0) ) { break; } } if(!iface) { log_printf("bind failed: no such address"); free_interfaces(ifaces); WSASetLastError(WSAEADDRNOTAVAIL); return -1; } memcpy(addr->sa_netnum, iface->ipx_net, 4); memcpy(addr->sa_nodenum, iface->ipx_node, 6); *nic_bcast = iface->bcast; free_interfaces(ifaces); EnterCriticalSection(&(router->crit_sec)); if(router_get(router, control, sock)) { log_printf("bind failed: socket already bound"); LeaveCriticalSection(&(router->crit_sec)); WSASetLastError(WSAEINVAL); return -1; } if(addr->sa_socket == 0) { /* Automatic socket allocations start at 1024, I have no idea if * this is normal IPX behaviour, but IP does it and it doesn't seem * to interfere with any IPX software I've tested. */ uint16_t s = 1024; struct router_addr *a = router->addrs; while(a) { if(ntohs(a->addr.sa_socket) == s) { if(s == 65535) { log_printf("bind failed: out of sockets?!"); LeaveCriticalSection(&(router->crit_sec)); WSASetLastError(WSAEADDRNOTAVAIL); return -1; } s++; a = router->addrs; continue; } a = a->next; } addr->sa_socket = htons(s); }else{ /* Test if any bound socket is using the requested socket number. */ struct router_addr *a = router->addrs; while(a) { if(a->addr.sa_socket == addr->sa_socket && (!a->reuse || !reuse)) { log_printf("bind failed: requested socket in use"); LeaveCriticalSection(&(router->crit_sec)); WSASetLastError(WSAEADDRINUSE); return -1; } a = a->next; } } struct router_addr *new_addr = malloc(sizeof(struct router_addr)); if(!new_addr) { LeaveCriticalSection(&(router->crit_sec)); WSASetLastError(ERROR_OUTOFMEMORY); return -1; } memcpy(&(new_addr->addr), addr, sizeof(struct sockaddr_ipx)); new_addr->local_port = 0; new_addr->ws_socket = sock; new_addr->control_socket = control; new_addr->filter_ptype = -1; new_addr->reuse = reuse; new_addr->next = NULL; router->addrs = new_addr; LeaveCriticalSection(&(router->crit_sec)); return 0; } /* Set loopback UDP port of emulation socket in NETWORK BYTE ORDER * Disable recv by setting to zero */ static void router_set_port(struct router_vars *router, SOCKET control, SOCKET sock, uint16_t port) { EnterCriticalSection(&(router->crit_sec)); struct router_addr *addr = router_get(router, control, sock); if(addr) { addr->local_port = port; } LeaveCriticalSection(&(router->crit_sec)); } static void router_unbind(struct router_vars *router, SOCKET control, SOCKET sock) { EnterCriticalSection(&(router->crit_sec)); struct router_addr *addr = router->addrs, *prev = NULL; while(addr) { if(addr->control_socket == control && addr->ws_socket == sock) { if(prev) { prev->next = addr->next; }else{ router->addrs = addr->next; } free(addr); break; } prev = addr; addr = addr->next; } LeaveCriticalSection(&(router->crit_sec)); } /* Return the address a given socket is bound to, NULL if unbound */ static struct router_addr *router_get(struct router_vars *router, SOCKET control, SOCKET sock) { EnterCriticalSection(&(router->crit_sec)); struct router_addr *addr = router->addrs; while(addr && (addr->control_socket != control || addr->ws_socket != sock)) { addr = addr->next; } LeaveCriticalSection(&(router->crit_sec)); return addr; } /* Set packet type filter for a socket * Disable filter by setting to negative value */ static void router_set_filter(struct router_vars *router, SOCKET control, SOCKET sock, int ptype) { EnterCriticalSection(&(router->crit_sec)); struct router_addr *addr = router_get(router, control, sock); if(addr) { addr->filter_ptype = ptype; } LeaveCriticalSection(&(router->crit_sec)); } static int router_set_reuse(struct router_vars *router, SOCKET control, SOCKET sock, BOOL reuse) { EnterCriticalSection(&(router->crit_sec)); struct router_addr *addr = router_get(router, control, sock); if(addr) { struct router_addr *test = router->addrs; while(test) { if(addr != test && memcmp(&(addr->addr), &(test->addr), sizeof(struct sockaddr_ipx)) == 0 && !reuse) { /* Refuse to disable SO_REUSEADDR when another binding for the same address exists */ LeaveCriticalSection(&(router->crit_sec)); return 0; } test = test->next; } addr->reuse = reuse; } LeaveCriticalSection(&(router->crit_sec)); return 1; } static BOOL router_handle_call(struct router_vars *router, int sock, struct router_call *call) { struct router_ret ret; ret.err_code = ERROR_SUCCESS; switch(call->call) { case rc_bind: { ret.ret_addr = call->arg_addr; if(router_bind(router, sock, call->sock, &(ret.ret_addr), &(ret.ret_u32), call->arg_int) == -1) { ret.err_code = WSAGetLastError(); } break; } case rc_unbind: { router_unbind(router, sock, call->sock); break; } case rc_port: { router_set_port(router, sock, call->sock, call->arg_int); break; } case rc_filter: { router_set_filter(router, sock, call->sock, call->arg_int); break; } case rc_reuse: { if(!router_set_reuse(router, sock, call->sock, call->arg_int)) { ret.err_code = WSAEINVAL; } break; } default: { log_printf("Recieved unknown call, dropping client"); return FALSE; } } int sent = 0, sr; while(sent < sizeof(ret)) { char *sbuf = ((char*)&ret) + sent; if((sr = send(sock, sbuf, sizeof(ret) - sent, 0)) == -1) { log_printf("Send error: %s, dropping client", w32_error(WSAGetLastError())); return FALSE; } sent += sr; } return TRUE; } static void router_drop_client(struct router_vars *router, int coff) { EnterCriticalSection(&(router->crit_sec)); struct router_addr *addr = router->addrs, *dp = NULL; while(addr) { dp = addr->control_socket == router->clients[coff].sock ? addr : NULL; addr = addr->next; if(dp) { router_unbind(router, dp->control_socket, dp->ws_socket); } } LeaveCriticalSection(&(router->crit_sec)); closesocket(router->clients[coff].sock); router->clients[coff] = router->clients[--router->client_count]; } BOOL rclient_init(struct rclient *rclient) { rclient->cs_init = FALSE; rclient->sock = -1; rclient->router = NULL; rclient->thread = NULL; if(InitializeCriticalSectionAndSpinCount(&(rclient->cs), 0x80000000)) { rclient->cs_init = TRUE; }else{ log_printf("Failed to initialise critical section: %s", w32_error(GetLastError())); return FALSE; } return TRUE; } /* Connect to the remote router process, spawns local (private) router thread if * it the remote one isn't running. * * Calling when a router is already running is a no-op. */ BOOL rclient_start(struct rclient *rclient) { if(rclient->sock != -1 || rclient->router) { return TRUE; } if((rclient->sock = socket(AF_INET, SOCK_STREAM, 0)) == -1) { log_printf("Cannot create TCP socket: %s", w32_error(WSAGetLastError())); return FALSE; } struct sockaddr_in addr; addr.sin_family = AF_INET; addr.sin_addr.s_addr = inet_addr("127.0.0.1"); addr.sin_port = htons(global_conf.udp_port); if(connect(rclient->sock, (struct sockaddr*)&addr, sizeof(addr)) == 0) { return TRUE; } log_printf("Cannot connect to router process: %s", w32_error(WSAGetLastError())); closesocket(rclient->sock); rclient->sock = -1; log_printf("Creating private router thread..."); if(!(rclient->router = router_init(FALSE))) { return FALSE; } rclient->thread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)&router_main, rclient->router, 0, NULL); if(!rclient->thread) { log_printf("Failed to create router thread: %s", w32_error(GetLastError())); router_destroy(rclient->router); rclient->router = NULL; return FALSE; } return TRUE; } /* Disconnect from the router process or stop the private router thread. * * Do not attempt to call rclient_start() again without calling rclient_init() * as the critical section object is deleted. */ void rclient_stop(struct rclient *rclient) { if(rclient->sock != -1) { closesocket(rclient->sock); rclient->sock = -1; } if(rclient->router) { EnterCriticalSection(&(rclient->router->crit_sec)); rclient->router->running = FALSE; WSASetEvent(rclient->router->wsa_event); LeaveCriticalSection(&(rclient->router->crit_sec)); if(WaitForSingleObject(rclient->thread, 3000) == WAIT_TIMEOUT) { log_printf("Router thread didn't exit in 3 seconds, terminating"); TerminateThread(rclient->thread, 0); } CloseHandle(rclient->thread); rclient->thread = NULL; router_destroy(rclient->router); rclient->router = NULL; } if(rclient->cs_init) { DeleteCriticalSection(&(rclient->cs)); rclient->cs_init = FALSE; } } static BOOL rclient_do(struct rclient *rclient, struct router_call *call, struct router_ret *ret) { EnterCriticalSection(&(rclient->cs)); int done, r; for(done = 0; done < sizeof(*call);) { if((r = send(rclient->sock, ((char*)call) + done, sizeof(*call) - done, 0)) == -1) { log_printf("rclient_do: send error: %s", w32_error(WSAGetLastError())); LeaveCriticalSection(&(rclient->cs)); return FALSE; } done += r; } for(done = 0; done < sizeof(*ret);) { if((r = recv(rclient->sock, ((char*)ret) + done, sizeof(*ret) - done, 0)) == -1) { log_printf("rclient_do: recv error: %s", w32_error(WSAGetLastError())); LeaveCriticalSection(&(rclient->cs)); return FALSE; }else if(r == 0) { log_printf("rclient_do: Lost connection"); WSASetLastError(WSAECONNRESET); LeaveCriticalSection(&(rclient->cs)); return FALSE; } done += r; } LeaveCriticalSection(&(rclient->cs)); return TRUE; } BOOL rclient_bind(struct rclient *rclient, SOCKET sock, struct sockaddr_ipx *addr, uint32_t *nic_bcast, BOOL reuse) { if(rclient->sock != -1) { struct router_call call; struct router_ret ret; call.call = rc_bind; call.sock = sock; call.arg_addr = *addr; call.arg_int = reuse; if(!rclient_do(rclient, &call, &ret)) { return FALSE; } if(ret.err_code == ERROR_SUCCESS) { *addr = ret.ret_addr; *nic_bcast = ret.ret_u32; return TRUE; }else{ WSASetLastError(ret.err_code); return FALSE; } }else if(rclient->router) { return router_bind(rclient->router, 0, sock, addr, nic_bcast, reuse) == 0 ? TRUE: FALSE; } log_printf("rclient_bind: No router?!"); WSASetLastError(WSAENETDOWN); return FALSE; } BOOL rclient_unbind(struct rclient *rclient, SOCKET sock) { if(rclient->sock != -1) { struct router_call call; struct router_ret ret; call.call = rc_unbind; call.sock = sock; if(!rclient_do(rclient, &call, &ret)) { return FALSE; } return TRUE; }else if(rclient->router) { router_unbind(rclient->router, 0, sock); return TRUE; } log_printf("rclient_unbind: No router?!"); WSASetLastError(WSAENETDOWN); return FALSE; } BOOL rclient_set_port(struct rclient *rclient, SOCKET sock, uint16_t port) { if(rclient->sock != -1) { struct router_call call; struct router_ret ret; call.call = rc_port; call.sock = sock; call.arg_int = port; if(!rclient_do(rclient, &call, &ret)) { return FALSE; } return TRUE; }else if(rclient->router) { router_set_port(rclient->router, 0, sock, port); return TRUE; } log_printf("rclient_set_port: No router?!"); WSASetLastError(WSAENETDOWN); return FALSE; } BOOL rclient_set_filter(struct rclient *rclient, SOCKET sock, int ptype) { if(rclient->sock != -1) { struct router_call call; struct router_ret ret; call.call = rc_filter; call.sock = sock; call.arg_int = ptype; if(!rclient_do(rclient, &call, &ret)) { return FALSE; } return TRUE; }else if(rclient->router) { router_set_filter(rclient->router, 0, sock, ptype); return TRUE; } log_printf("rclient_set_filter: No router?!"); WSASetLastError(WSAENETDOWN); return FALSE; } BOOL rclient_set_reuse(struct rclient *rclient, SOCKET sock, BOOL reuse) { if(rclient->sock != -1) { struct router_call call; struct router_ret ret; call.call = rc_reuse; call.sock = sock; call.arg_int = reuse; if(!rclient_do(rclient, &call, &ret)) { return FALSE; } if(ret.err_code == ERROR_SUCCESS) { return TRUE; }else{ WSASetLastError(WSAEINVAL); return FALSE; } }else if(rclient->router) { router_set_reuse(rclient->router, 0, sock, reuse); return TRUE; } log_printf("rclient_set_reuse: No router?!"); WSASetLastError(WSAENETDOWN); return FALSE; }