/* * Windows networking abstraction. * * Due to this clean abstraction it was possible * to easily implement IPv6 support :) * * IPv6 patch 1 (27 October 2000) Jeroen Massar * - Preliminary hacked IPv6 support. * - Connecting to IPv6 address (eg fec0:4242:4242:100:2d0:b7ff:fe8f:5d42) works. * - Connecting to IPv6 hostname (eg heaven.ipv6.unfix.org) works. * - Compiles as either IPv4 or IPv6. * * IPv6 patch 2 (29 October 2000) Jeroen Massar * - When compiled as IPv6 it also allows connecting to IPv4 hosts. * - Added some more documentation. * * IPv6 patch 3 (18 November 2000) Jeroen Massar * - It now supports dynamically loading the IPv6 resolver dll's. * This way we should be able to distribute one (1) binary * which supports both IPv4 and IPv6. * - getaddrinfo() and getnameinfo() are loaded dynamicaly if possible. * - in6addr_any is defined in this file so we don't need to link to wship6.lib * - The patch is now more unified so that we can still * remove all IPv6 support by undef'ing IPV6. * But where it fallsback to IPv4 it uses the IPv4 code which is already in place... * - Canonical name resolving works. * * IPv6 patch 4 (07 January 2001) Jeroen Massar * - patch against CVS of today, will be submitted to the bugs list * as a 'cvs diff -u' on Simon's request... * */ /* * Define IPV6 to have IPv6 on-the-fly-loading support. * This means that one doesn't have to have an IPv6 stack to use it. * But if an IPv6 stack is found it is used with a fallback to IPv4. */ /* #define IPV6 1 */ #ifdef IPV6 #include #include #include #else #include #endif #include #include #include #include #define DEFINE_PLUG_METHOD_MACROS #include "putty.h" #include "network.h" #include "tree234.h" struct Socket_tag { struct socket_function_table *fn; /* the above variable absolutely *must* be the first in this structure */ char *error; SOCKET s; Plug plug; void *private_ptr; bufchain output_data; int connected; int writable; int frozen; /* this causes readability notifications to be ignored */ int frozen_readable; /* this means we missed at least one readability * notification while we were frozen */ int localhost_only; /* for listening sockets */ char oobdata[1]; int sending_oob; int oobinline; int pending_error; /* in case send() returns error */ }; /* * We used to typedef struct Socket_tag *Socket. * * Since we have made the networking abstraction slightly more * abstract, Socket no longer means a tcp socket (it could mean * an ssl socket). So now we must use Actual_Socket when we know * we are talking about a tcp socket. */ typedef struct Socket_tag *Actual_Socket; struct SockAddr_tag { char *error; /* address family this belongs to, AF_INET for IPv4, AF_INET6 for IPv6. */ int family; unsigned long address; /* Address IPv4 style. */ #ifdef IPV6 struct addrinfo *ai; /* Address IPv6 style. */ #endif }; static tree234 *sktree; static int cmpfortree(void *av, void *bv) { Actual_Socket a = (Actual_Socket) av, b = (Actual_Socket) bv; unsigned long as = (unsigned long) a->s, bs = (unsigned long) b->s; if (as < bs) return -1; if (as > bs) return +1; return 0; } static int cmpforsearch(void *av, void *bv) { Actual_Socket b = (Actual_Socket) bv; unsigned long as = (unsigned long) av, bs = (unsigned long) b->s; if (as < bs) return -1; if (as > bs) return +1; return 0; } void sk_init(void) { sktree = newtree234(cmpfortree); } void sk_cleanup(void) { Actual_Socket s; int i; if (sktree) { for (i = 0; (s = index234(sktree, i)) != NULL; i++) { closesocket(s->s); } } } char *winsock_error_string(int error) { switch (error) { case WSAEACCES: return "Network error: Permission denied"; case WSAEADDRINUSE: return "Network error: Address already in use"; case WSAEADDRNOTAVAIL: return "Network error: Cannot assign requested address"; case WSAEAFNOSUPPORT: return "Network error: Address family not supported by protocol family"; case WSAEALREADY: return "Network error: Operation already in progress"; case WSAECONNABORTED: return "Network error: Software caused connection abort"; case WSAECONNREFUSED: return "Network error: Connection refused"; case WSAECONNRESET: return "Network error: Connection reset by peer"; case WSAEDESTADDRREQ: return "Network error: Destination address required"; case WSAEFAULT: return "Network error: Bad address"; case WSAEHOSTDOWN: return "Network error: Host is down"; case WSAEHOSTUNREACH: return "Network error: No route to host"; case WSAEINPROGRESS: return "Network error: Operation now in progress"; case WSAEINTR: return "Network error: Interrupted function call"; case WSAEINVAL: return "Network error: Invalid argument"; case WSAEISCONN: return "Network error: Socket is already connected"; case WSAEMFILE: return "Network error: Too many open files"; case WSAEMSGSIZE: return "Network error: Message too long"; case WSAENETDOWN: return "Network error: Network is down"; case WSAENETRESET: return "Network error: Network dropped connection on reset"; case WSAENETUNREACH: return "Network error: Network is unreachable"; case WSAENOBUFS: return "Network error: No buffer space available"; case WSAENOPROTOOPT: return "Network error: Bad protocol option"; case WSAENOTCONN: return "Network error: Socket is not connected"; case WSAENOTSOCK: return "Network error: Socket operation on non-socket"; case WSAEOPNOTSUPP: return "Network error: Operation not supported"; case WSAEPFNOSUPPORT: return "Network error: Protocol family not supported"; case WSAEPROCLIM: return "Network error: Too many processes"; case WSAEPROTONOSUPPORT: return "Network error: Protocol not supported"; case WSAEPROTOTYPE: return "Network error: Protocol wrong type for socket"; case WSAESHUTDOWN: return "Network error: Cannot send after socket shutdown"; case WSAESOCKTNOSUPPORT: return "Network error: Socket type not supported"; case WSAETIMEDOUT: return "Network error: Connection timed out"; case WSAEWOULDBLOCK: return "Network error: Resource temporarily unavailable"; case WSAEDISCON: return "Network error: Graceful shutdown in progress"; default: return "Unknown network error"; } } SockAddr sk_namelookup(char *host, char **canonicalname) { SockAddr ret = smalloc(sizeof(struct SockAddr_tag)); unsigned long a; struct hostent *h = NULL; char realhost[8192]; /* Clear the structure and default to IPv4. */ memset(ret, 0, sizeof(struct SockAddr_tag)); ret->family = 0; /* We set this one when we have resolved the host. */ *realhost = '\0'; if ((a = inet_addr(host)) == (unsigned long) INADDR_NONE) { #ifdef IPV6 /* Try to get the getaddrinfo() function from wship6.dll */ /* This way one doesn't need to have IPv6 dll's to use PuTTY and * it will fallback to IPv4. */ typedef int (CALLBACK * FGETADDRINFO) (const char *nodename, const char *servname, const struct addrinfo * hints, struct addrinfo ** res); FGETADDRINFO fGetAddrInfo = NULL; HINSTANCE dllWSHIP6 = LoadLibrary("wship6.dll"); if (dllWSHIP6) fGetAddrInfo = (FGETADDRINFO) GetProcAddress(dllWSHIP6, "getaddrinfo"); /* * Use fGetAddrInfo when it's available (which usually also * means IPv6 is installed...) */ if (fGetAddrInfo) { /*debug(("Resolving \"%s\" with getaddrinfo() (IPv4+IPv6 capable)...\n", host)); */ if (fGetAddrInfo(host, NULL, NULL, &ret->ai) == 0) ret->family = ret->ai->ai_family; } else #endif { /* * Otherwise use the IPv4-only gethostbyname... * (NOTE: we don't use gethostbyname as a * fallback!) */ if (ret->family == 0) { /*debug(("Resolving \"%s\" with gethostbyname() (IPv4 only)...\n", host)); */ if ( (h = gethostbyname(host)) ) ret->family = AF_INET; } } /*debug(("Done resolving...(family is %d) AF_INET = %d, AF_INET6 = %d\n", ret->family, AF_INET, AF_INET6)); */ if (ret->family == 0) { DWORD err = WSAGetLastError(); ret->error = (err == WSAENETDOWN ? "Network is down" : err == WSAHOST_NOT_FOUND ? "Host does not exist" : err == WSATRY_AGAIN ? "Host not found" : #ifdef IPV6 fGetAddrInfo ? "getaddrinfo: unknown error" : #endif "gethostbyname: unknown error"); #ifdef DEBUG { LPVOID lpMsgBuf; FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) & lpMsgBuf, 0, NULL); /*debug(("Error %ld: %s (h=%lx)\n", err, lpMsgBuf, h)); */ /* Free the buffer. */ LocalFree(lpMsgBuf); } #endif } else { ret->error = NULL; #ifdef IPV6 /* If we got an address info use that... */ if (ret->ai) { typedef int (CALLBACK * FGETNAMEINFO) (const struct sockaddr FAR * sa, socklen_t salen, char FAR * host, size_t hostlen, char FAR * serv, size_t servlen, int flags); FGETNAMEINFO fGetNameInfo = NULL; /* Are we in IPv4 fallback mode? */ /* We put the IPv4 address into the a variable so we can further-on use the IPv4 code... */ if (ret->family == AF_INET) memcpy(&a, (char *) &((SOCKADDR_IN *) ret->ai-> ai_addr)->sin_addr, sizeof(a)); /* Now let's find that canonicalname... */ if ((dllWSHIP6) && (fGetNameInfo = (FGETNAMEINFO) GetProcAddress(dllWSHIP6, "getnameinfo"))) { if (fGetNameInfo ((struct sockaddr *) ret->ai->ai_addr, ret->family == AF_INET ? sizeof(SOCKADDR_IN) : sizeof(SOCKADDR_IN6), realhost, sizeof(realhost), NULL, 0, 0) != 0) { strncpy(realhost, host, sizeof(realhost)); } } } /* We used the IPv4-only gethostbyname()... */ else #endif { memcpy(&a, h->h_addr, sizeof(a)); /* This way we are always sure the h->h_name is valid :) */ strncpy(realhost, h->h_name, sizeof(realhost)); } } #ifdef IPV6 FreeLibrary(dllWSHIP6); #endif } else { /* * This must be a numeric IPv4 address because it caused a * success return from inet_addr. */ ret->family = AF_INET; strncpy(realhost, host, sizeof(realhost)); } ret->address = ntohl(a); realhost[lenof(realhost)-1] = '\0'; *canonicalname = smalloc(1+strlen(realhost)); strcpy(*canonicalname, realhost); return ret; } void sk_getaddr(SockAddr addr, char *buf, int buflen) { #ifdef IPV6 if (addr->family == AF_INET) { #endif struct in_addr a; a.s_addr = htonl(addr->address); strncpy(buf, inet_ntoa(a), buflen); #ifdef IPV6 } else { FIXME; /* I don't know how to get a text form of an IPv6 address. */ } #endif } int sk_addrtype(SockAddr addr) { return addr->family; } void sk_addrcopy(SockAddr addr, char *buf) { #ifdef IPV6 if (addr->family == AF_INET) { #endif struct in_addr a; a.s_addr = htonl(addr->address); memcpy(buf, (char*) &a.s_addr, 4); #ifdef IPV6 } else { memcpy(buf, (char*) addr->ai, 16); } #endif } void sk_addr_free(SockAddr addr) { sfree(addr); } static Plug sk_tcp_plug(Socket sock, Plug p) { Actual_Socket s = (Actual_Socket) sock; Plug ret = s->plug; if (p) s->plug = p; return ret; } static void sk_tcp_flush(Socket s) { /* * We send data to the socket as soon as we can anyway, * so we don't need to do anything here. :-) */ } static void sk_tcp_close(Socket s); static int sk_tcp_write(Socket s, char *data, int len); static int sk_tcp_write_oob(Socket s, char *data, int len); static void sk_tcp_set_private_ptr(Socket s, void *ptr); static void *sk_tcp_get_private_ptr(Socket s); static void sk_tcp_set_frozen(Socket s, int is_frozen); static char *sk_tcp_socket_error(Socket s); extern char *do_select(SOCKET skt, int startup); Socket sk_register(void *sock, Plug plug) { static struct socket_function_table fn_table = { sk_tcp_plug, sk_tcp_close, sk_tcp_write, sk_tcp_write_oob, sk_tcp_flush, sk_tcp_set_private_ptr, sk_tcp_get_private_ptr, sk_tcp_set_frozen, sk_tcp_socket_error }; DWORD err; char *errstr; Actual_Socket ret; /* * Create Socket structure. */ ret = smalloc(sizeof(struct Socket_tag)); ret->fn = &fn_table; ret->error = NULL; ret->plug = plug; bufchain_init(&ret->output_data); ret->writable = 1; /* to start with */ ret->sending_oob = 0; ret->frozen = 1; ret->frozen_readable = 0; ret->localhost_only = 0; /* unused, but best init anyway */ ret->pending_error = 0; ret->s = (SOCKET)sock; if (ret->s == INVALID_SOCKET) { err = WSAGetLastError(); ret->error = winsock_error_string(err); return (Socket) ret; } ret->oobinline = 0; /* Set up a select mechanism. This could be an AsyncSelect on a * window, or an EventSelect on an event object. */ errstr = do_select(ret->s, 1); if (errstr) { ret->error = errstr; return (Socket) ret; } add234(sktree, ret); return (Socket) ret; } Socket sk_new(SockAddr addr, int port, int privport, int oobinline, int nodelay, Plug plug) { static struct socket_function_table fn_table = { sk_tcp_plug, sk_tcp_close, sk_tcp_write, sk_tcp_write_oob, sk_tcp_flush, sk_tcp_set_private_ptr, sk_tcp_get_private_ptr, sk_tcp_set_frozen, sk_tcp_socket_error }; SOCKET s; #ifdef IPV6 SOCKADDR_IN6 a6; #endif SOCKADDR_IN a; DWORD err; char *errstr; Actual_Socket ret; short localport; /* * Create Socket structure. */ ret = smalloc(sizeof(struct Socket_tag)); ret->fn = &fn_table; ret->error = NULL; ret->plug = plug; bufchain_init(&ret->output_data); ret->connected = 0; /* to start with */ ret->writable = 0; /* to start with */ ret->sending_oob = 0; ret->frozen = 0; ret->frozen_readable = 0; ret->localhost_only = 0; /* unused, but best init anyway */ ret->pending_error = 0; /* * Open socket. */ s = socket(addr->family, SOCK_STREAM, 0); ret->s = s; if (s == INVALID_SOCKET) { err = WSAGetLastError(); ret->error = winsock_error_string(err); return (Socket) ret; } ret->oobinline = oobinline; if (oobinline) { BOOL b = TRUE; setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (void *) &b, sizeof(b)); } if (nodelay) { BOOL b = TRUE; setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (void *) &b, sizeof(b)); } /* * Bind to local address. */ if (privport) localport = 1023; /* count from 1023 downwards */ else localport = 0; /* just use port 0 (ie winsock picks) */ /* Loop round trying to bind */ while (1) { int retcode; #ifdef IPV6 if (addr->family == AF_INET6) { memset(&a6, 0, sizeof(a6)); a6.sin6_family = AF_INET6; /*a6.sin6_addr = in6addr_any; *//* == 0 */ a6.sin6_port = htons(localport); } else #endif { a.sin_family = AF_INET; a.sin_addr.s_addr = htonl(INADDR_ANY); a.sin_port = htons(localport); } #ifdef IPV6 retcode = bind(s, (addr->family == AF_INET6 ? (struct sockaddr *) &a6 : (struct sockaddr *) &a), (addr->family == AF_INET6 ? sizeof(a6) : sizeof(a))); #else retcode = bind(s, (struct sockaddr *) &a, sizeof(a)); #endif if (retcode != SOCKET_ERROR) { err = 0; break; /* done */ } else { err = WSAGetLastError(); if (err != WSAEADDRINUSE) /* failed, for a bad reason */ break; } if (localport == 0) break; /* we're only looping once */ localport--; if (localport == 0) break; /* we might have got to the end */ } if (err) { ret->error = winsock_error_string(err); return (Socket) ret; } /* * Connect to remote address. */ #ifdef IPV6 if (addr->family == AF_INET6) { memset(&a, 0, sizeof(a)); a6.sin6_family = AF_INET6; a6.sin6_port = htons((short) port); a6.sin6_addr = ((struct sockaddr_in6 *) addr->ai->ai_addr)->sin6_addr; } else #endif { a.sin_family = AF_INET; a.sin_addr.s_addr = htonl(addr->address); a.sin_port = htons((short) port); } /* Set up a select mechanism. This could be an AsyncSelect on a * window, or an EventSelect on an event object. */ errstr = do_select(s, 1); if (errstr) { ret->error = errstr; return (Socket) ret; } if (( #ifdef IPV6 connect(s, ((addr->family == AF_INET6) ? (struct sockaddr *) &a6 : (struct sockaddr *) &a), (addr->family == AF_INET6) ? sizeof(a6) : sizeof(a)) #else connect(s, (struct sockaddr *) &a, sizeof(a)) #endif ) == SOCKET_ERROR) { err = WSAGetLastError(); /* * We expect a potential EWOULDBLOCK here, because the * chances are the front end has done a select for * FD_CONNECT, so that connect() will complete * asynchronously. */ if ( err != WSAEWOULDBLOCK ) { ret->error = winsock_error_string(err); return (Socket) ret; } } else { /* * If we _don't_ get EWOULDBLOCK, the connect has completed * and we should set the socket as writable. */ ret->writable = 1; } add234(sktree, ret); return (Socket) ret; } Socket sk_newlistener(int port, Plug plug, int local_host_only) { static struct socket_function_table fn_table = { sk_tcp_plug, sk_tcp_close, sk_tcp_write, sk_tcp_write_oob, sk_tcp_flush, sk_tcp_set_private_ptr, sk_tcp_get_private_ptr, sk_tcp_set_frozen, sk_tcp_socket_error }; SOCKET s; #ifdef IPV6 SOCKADDR_IN6 a6; #endif SOCKADDR_IN a; DWORD err; char *errstr; Actual_Socket ret; int retcode; int on = 1; /* * Create Socket structure. */ ret = smalloc(sizeof(struct Socket_tag)); ret->fn = &fn_table; ret->error = NULL; ret->plug = plug; bufchain_init(&ret->output_data); ret->writable = 0; /* to start with */ ret->sending_oob = 0; ret->frozen = 0; ret->frozen_readable = 0; ret->localhost_only = local_host_only; ret->pending_error = 0; /* * Open socket. */ s = socket(AF_INET, SOCK_STREAM, 0); ret->s = s; if (s == INVALID_SOCKET) { err = WSAGetLastError(); ret->error = winsock_error_string(err); return (Socket) ret; } ret->oobinline = 0; setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on)); #ifdef IPV6 if (addr->family == AF_INET6) { memset(&a6, 0, sizeof(a6)); a6.sin6_family = AF_INET6; if (local_host_only) a6.sin6_addr = in6addr_loopback; else a6.sin6_addr = in6addr_any; a6.sin6_port = htons(port); } else #endif { a.sin_family = AF_INET; if (local_host_only) a.sin_addr.s_addr = htonl(INADDR_LOOPBACK); else a.sin_addr.s_addr = htonl(INADDR_ANY); a.sin_port = htons((short)port); } #ifdef IPV6 retcode = bind(s, (addr->family == AF_INET6 ? (struct sockaddr *) &a6 : (struct sockaddr *) &a), (addr->family == AF_INET6 ? sizeof(a6) : sizeof(a))); #else retcode = bind(s, (struct sockaddr *) &a, sizeof(a)); #endif if (retcode != SOCKET_ERROR) { err = 0; } else { err = WSAGetLastError(); } if (err) { ret->error = winsock_error_string(err); return (Socket) ret; } if (listen(s, SOMAXCONN) == SOCKET_ERROR) { closesocket(s); ret->error = winsock_error_string(err); return (Socket) ret; } /* Set up a select mechanism. This could be an AsyncSelect on a * window, or an EventSelect on an event object. */ errstr = do_select(s, 1); if (errstr) { ret->error = errstr; return (Socket) ret; } add234(sktree, ret); return (Socket) ret; } static void sk_tcp_close(Socket sock) { extern char *do_select(SOCKET skt, int startup); Actual_Socket s = (Actual_Socket) sock; del234(sktree, s); do_select(s->s, 0); closesocket(s->s); sfree(s); } /* * The function which tries to send on a socket once it's deemed * writable. */ void try_send(Actual_Socket s) { while (s->sending_oob || bufchain_size(&s->output_data) > 0) { int nsent; DWORD err; void *data; int len, urgentflag; if (s->sending_oob) { urgentflag = MSG_OOB; len = s->sending_oob; data = &s->oobdata; } else { urgentflag = 0; bufchain_prefix(&s->output_data, &data, &len); } nsent = send(s->s, data, len, urgentflag); noise_ultralight(nsent); if (nsent <= 0) { err = (nsent < 0 ? WSAGetLastError() : 0); if ((err < WSABASEERR && nsent < 0) || err == WSAEWOULDBLOCK) { /* * Perfectly normal: we've sent all we can for the moment. * * (Some WinSock send() implementations can return * <0 but leave no sensible error indication - * WSAGetLastError() is called but returns zero or * a small number - so we check that case and treat * it just like WSAEWOULDBLOCK.) */ s->writable = FALSE; return; } else if (nsent == 0 || err == WSAECONNABORTED || err == WSAECONNRESET) { /* * If send() returns CONNABORTED or CONNRESET, we * unfortunately can't just call plug_closing(), * because it's quite likely that we're currently * _in_ a call from the code we'd be calling back * to, so we'd have to make half the SSH code * reentrant. Instead we flag a pending error on * the socket, to be dealt with (by calling * plug_closing()) at some suitable future moment. */ s->pending_error = err; return; } else { logevent(winsock_error_string(err)); fatalbox("%s", winsock_error_string(err)); } } else { if (s->sending_oob) { if (nsent < len) { memmove(s->oobdata, s->oobdata+nsent, len-nsent); s->sending_oob = len - nsent; } else { s->sending_oob = 0; } } else { bufchain_consume(&s->output_data, nsent); } } } } static int sk_tcp_write(Socket sock, char *buf, int len) { Actual_Socket s = (Actual_Socket) sock; /* * Add the data to the buffer list on the socket. */ bufchain_add(&s->output_data, buf, len); /* * Now try sending from the start of the buffer list. */ if (s->writable) try_send(s); return bufchain_size(&s->output_data); } static int sk_tcp_write_oob(Socket sock, char *buf, int len) { Actual_Socket s = (Actual_Socket) sock; /* * Replace the buffer list on the socket with the data. */ bufchain_clear(&s->output_data); assert(len <= sizeof(s->oobdata)); memcpy(s->oobdata, buf, len); s->sending_oob = len; /* * Now try sending from the start of the buffer list. */ if (s->writable) try_send(s); return s->sending_oob; } int select_result(WPARAM wParam, LPARAM lParam) { int ret, open; DWORD err; char buf[20480]; /* nice big buffer for plenty of speed */ Actual_Socket s; u_long atmark; /* wParam is the socket itself */ s = find234(sktree, (void *) wParam, cmpforsearch); if (!s) return 1; /* boggle */ if ((err = WSAGETSELECTERROR(lParam)) != 0) { /* * An error has occurred on this socket. Pass it to the * plug. */ return plug_closing(s->plug, winsock_error_string(err), err, 0); } noise_ultralight(lParam); switch (WSAGETSELECTEVENT(lParam)) { case FD_CONNECT: s->connected = s->writable = 1; break; case FD_READ: /* In the case the socket is still frozen, we don't even bother */ if (s->frozen) { s->frozen_readable = 1; break; } /* * We have received data on the socket. For an oobinline * socket, this might be data _before_ an urgent pointer, * in which case we send it to the back end with type==1 * (data prior to urgent). */ if (s->oobinline) { atmark = 1; ioctlsocket(s->s, SIOCATMARK, &atmark); /* * Avoid checking the return value from ioctlsocket(), * on the grounds that some WinSock wrappers don't * support it. If it does nothing, we get atmark==1, * which is equivalent to `no OOB pending', so the * effect will be to non-OOB-ify any OOB data. */ } else atmark = 1; ret = recv(s->s, buf, sizeof(buf), 0); noise_ultralight(ret); if (ret < 0) { err = WSAGetLastError(); if (err == WSAEWOULDBLOCK) { break; } } if (ret < 0) { return plug_closing(s->plug, winsock_error_string(err), err, 0); } else if (0 == ret) { return plug_closing(s->plug, NULL, 0, 0); } else { return plug_receive(s->plug, atmark ? 0 : 1, buf, ret); } break; case FD_OOB: /* * This will only happen on a non-oobinline socket. It * indicates that we can immediately perform an OOB read * and get back OOB data, which we will send to the back * end with type==2 (urgent data). */ ret = recv(s->s, buf, sizeof(buf), MSG_OOB); noise_ultralight(ret); if (ret <= 0) { char *str = (ret == 0 ? "Internal networking trouble" : winsock_error_string(WSAGetLastError())); logevent(str); fatalbox("%s", str); } else { return plug_receive(s->plug, 2, buf, ret); } break; case FD_WRITE: { int bufsize_before, bufsize_after; s->writable = 1; bufsize_before = s->sending_oob + bufchain_size(&s->output_data); try_send(s); bufsize_after = s->sending_oob + bufchain_size(&s->output_data); if (bufsize_after < bufsize_before) plug_sent(s->plug, bufsize_after); } break; case FD_CLOSE: /* Signal a close on the socket. First read any outstanding data. */ open = 1; do { ret = recv(s->s, buf, sizeof(buf), 0); if (ret < 0) { err = WSAGetLastError(); if (err == WSAEWOULDBLOCK) break; return plug_closing(s->plug, winsock_error_string(err), err, 0); } else { if (ret) open &= plug_receive(s->plug, 0, buf, ret); else open &= plug_closing(s->plug, NULL, 0, 0); } } while (ret > 0); return open; case FD_ACCEPT: { struct sockaddr_in isa; int addrlen = sizeof(struct sockaddr_in); SOCKET t; /* socket of connection */ memset(&isa, 0, sizeof(struct sockaddr_in)); err = 0; t = accept(s->s,(struct sockaddr *)&isa,&addrlen); if (t == INVALID_SOCKET) { err = WSAGetLastError(); if (err == WSATRY_AGAIN) break; } if (s->localhost_only && ntohl(isa.sin_addr.s_addr) != INADDR_LOOPBACK) { closesocket(t); /* dodgy WinSock let nonlocal through */ } else if (plug_accepting(s->plug, (void*)t)) { closesocket(t); /* denied or error */ } } } return 1; } /* * Deal with socket errors detected in try_send(). */ void net_pending_errors(void) { int i; Actual_Socket s; /* * This might be a fiddly business, because it's just possible * that handling a pending error on one socket might cause * others to be closed. (I can't think of any reason this might * happen in current SSH implementation, but to maintain * generality of this network layer I'll assume the worst.) * * So what we'll do is search the socket list for _one_ socket * with a pending error, and then handle it, and then search * the list again _from the beginning_. Repeat until we make a * pass with no socket errors present. That way we are * protected against the socket list changing under our feet. */ do { for (i = 0; (s = index234(sktree, i)) != NULL; i++) { if (s->pending_error) { /* * An error has occurred on this socket. Pass it to the * plug. */ plug_closing(s->plug, winsock_error_string(s->pending_error), s->pending_error, 0); break; } } } while (s); } /* * Each socket abstraction contains a `void *' private field in * which the client can keep state. */ static void sk_tcp_set_private_ptr(Socket sock, void *ptr) { Actual_Socket s = (Actual_Socket) sock; s->private_ptr = ptr; } static void *sk_tcp_get_private_ptr(Socket sock) { Actual_Socket s = (Actual_Socket) sock; return s->private_ptr; } /* * Special error values are returned from sk_namelookup and sk_new * if there's a problem. These functions extract an error message, * or return NULL if there's no problem. */ char *sk_addr_error(SockAddr addr) { return addr->error; } static char *sk_tcp_socket_error(Socket sock) { Actual_Socket s = (Actual_Socket) sock; return s->error; } static void sk_tcp_set_frozen(Socket sock, int is_frozen) { Actual_Socket s = (Actual_Socket) sock; if (s->frozen == is_frozen) return; s->frozen = is_frozen; if (!is_frozen && s->frozen_readable) { char c; recv(s->s, &c, 1, MSG_PEEK); } s->frozen_readable = 0; } /* * For Plink: enumerate all sockets currently active. */ SOCKET first_socket(int *state) { Actual_Socket s; *state = 0; s = index234(sktree, (*state)++); return s ? s->s : INVALID_SOCKET; } SOCKET next_socket(int *state) { Actual_Socket s = index234(sktree, (*state)++); return s ? s->s : INVALID_SOCKET; }