/* * Unix networking abstraction. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DEFINE_PLUG_METHOD_MACROS #include "putty.h" #include "network.h" #include "tree234.h" #ifndef X11_UNIX_PATH # define X11_UNIX_PATH "/tmp/.X11-unix/X" #endif #define ipv4_is_loopback(addr) (inet_netof(addr) == IN_LOOPBACKNET) struct Socket_tag { struct socket_function_table *fn; /* the above variable absolutely *must* be the first in this structure */ const char *error; int 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 oobpending; /* is there OOB data available to read? */ int oobinline; int pending_error; /* in case send() returns error */ int listener; int nodelay, keepalive; /* for connect()-type sockets */ int privport, port; /* and again */ SockAddr addr; }; /* * 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 { const char *error; /* * Which address family this address belongs to. AF_INET for * IPv4; AF_INET6 for IPv6; AF_UNSPEC indicates that name * resolution has not been done and a simple host name is held * in this SockAddr structure. */ int family; #ifndef NO_IPV6 struct addrinfo *ais; /* Addresses IPv6 style. */ struct addrinfo *ai; /* steps along the linked list */ #else unsigned long *addresses; /* Addresses IPv4 style. */ int naddresses, curraddr; #endif char hostname[512]; /* Store an unresolved host name. */ }; static tree234 *sktree; static void uxsel_tell(Actual_Socket s); static int cmpfortree(void *av, void *bv) { Actual_Socket a = (Actual_Socket) av, b = (Actual_Socket) bv; int as = a->s, bs = 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; int as = *(int *)av, bs = 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++) { close(s->s); } } } SockAddr sk_namelookup(const char *host, char **canonicalname, int address_family) { SockAddr ret = snew(struct SockAddr_tag); #ifndef NO_IPV6 struct addrinfo hints; int err; #else unsigned long a; struct hostent *h = NULL; int n; #endif 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'; ret->error = NULL; #ifndef NO_IPV6 hints.ai_flags = AI_CANONNAME; hints.ai_family = (address_family == ADDRTYPE_IPV4 ? AF_INET : address_family == ADDRTYPE_IPV6 ? AF_INET6 : AF_UNSPEC); hints.ai_socktype = SOCK_STREAM; hints.ai_protocol = 0; hints.ai_addrlen = 0; hints.ai_addr = NULL; hints.ai_canonname = NULL; hints.ai_next = NULL; err = getaddrinfo(host, NULL, &hints, &ret->ais); ret->ai = ret->ais; if (err != 0) { ret->error = gai_strerror(err); return ret; } ret->family = ret->ai->ai_family; *realhost = '\0'; if (ret->ai->ai_canonname != NULL) strncat(realhost, ret->ai->ai_canonname, sizeof(realhost) - 1); else strncat(realhost, host, sizeof(realhost) - 1); #else if ((a = inet_addr(host)) == (unsigned long)(in_addr_t)(-1)) { /* * 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; } if (ret->family == 0) { ret->error = (h_errno == HOST_NOT_FOUND || h_errno == NO_DATA || h_errno == NO_ADDRESS ? "Host does not exist" : h_errno == TRY_AGAIN ? "Temporary name service failure" : "gethostbyname: unknown error"); return ret; } /* This way we are always sure the h->h_name is valid :) */ strncpy(realhost, h->h_name, sizeof(realhost)); for (n = 0; h->h_addr_list[n]; n++); ret->addresses = snewn(n, unsigned long); ret->naddresses = n; for (n = 0; n < ret->naddresses; n++) { memcpy(&a, h->h_addr_list[n], sizeof(a)); ret->addresses[n] = ntohl(a); } } 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->addresses = snew(unsigned long); ret->naddresses = 1; ret->addresses[0] = ntohl(a); ret->curraddr = 0; } #endif realhost[lenof(realhost)-1] = '\0'; *canonicalname = snewn(1+strlen(realhost), char); strcpy(*canonicalname, realhost); return ret; } SockAddr sk_nonamelookup(const char *host) { SockAddr ret = snew(struct SockAddr_tag); ret->error = NULL; ret->family = AF_UNSPEC; strncpy(ret->hostname, host, lenof(ret->hostname)); ret->hostname[lenof(ret->hostname)-1] = '\0'; #ifndef NO_IPV6 ret->ais = NULL; #else ret->addresses = NULL; #endif return ret; } static int sk_nextaddr(SockAddr addr) { #ifndef NO_IPV6 if (addr->ai->ai_next) { addr->ai = addr->ai->ai_next; addr->family = addr->ai->ai_family; return TRUE; } else return FALSE; #else if (addr->curraddr+1 < addr->naddresses) { addr->curraddr++; return TRUE; } else { return FALSE; } #endif } void sk_getaddr(SockAddr addr, char *buf, int buflen) { if (addr->family == AF_UNSPEC) { strncpy(buf, addr->hostname, buflen); buf[buflen-1] = '\0'; } else { #ifndef NO_IPV6 if (getnameinfo(addr->ai->ai_addr, addr->ai->ai_addrlen, buf, buflen, NULL, 0, NI_NUMERICHOST) != 0) { buf[0] = '\0'; strncat(buf, "", buflen - 1); } #else struct in_addr a; assert(addr->family == AF_INET); a.s_addr = htonl(addr->addresses[addr->curraddr]); strncpy(buf, inet_ntoa(a), buflen); buf[buflen-1] = '\0'; #endif } } int sk_hostname_is_local(char *name) { return !strcmp(name, "localhost"); } int sk_address_is_local(SockAddr addr) { if (addr->family == AF_UNSPEC) return 0; /* we don't know; assume not */ else { #ifndef NO_IPV6 if (addr->family == AF_INET) return ipv4_is_loopback( ((struct sockaddr_in *)addr->ai->ai_addr)->sin_addr); else if (addr->family == AF_INET6) return IN6_IS_ADDR_LOOPBACK( &((struct sockaddr_in6 *)addr->ai->ai_addr)->sin6_addr); else return 0; #else struct in_addr a; assert(addr->family == AF_INET); a.s_addr = htonl(addr->addresses[addr->curraddr]); return ipv4_is_loopback(a); #endif } } int sk_addrtype(SockAddr addr) { return (addr->family == AF_INET ? ADDRTYPE_IPV4 : #ifndef NO_IPV6 addr->family == AF_INET6 ? ADDRTYPE_IPV6 : #endif ADDRTYPE_NAME); } void sk_addrcopy(SockAddr addr, char *buf) { #ifndef NO_IPV6 if (addr->family == AF_INET) memcpy(buf, &((struct sockaddr_in *)addr->ai->ai_addr)->sin_addr, sizeof(struct in_addr)); else if (addr->family == AF_INET6) memcpy(buf, &((struct sockaddr_in6 *)addr->ai->ai_addr)->sin6_addr, sizeof(struct in6_addr)); else assert(FALSE); #else struct in_addr a; assert(addr->family == AF_INET); a.s_addr = htonl(addr->addresses[addr->curraddr]); memcpy(buf, (char*) &a.s_addr, 4); #endif } void sk_addr_free(SockAddr addr) { #ifndef NO_IPV6 if (addr->ais != NULL) freeaddrinfo(addr->ais); #else sfree(addr->addresses); #endif 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, const char *data, int len); static int sk_tcp_write_oob(Socket s, const 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 const char *sk_tcp_socket_error(Socket s); static struct socket_function_table tcp_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 sk_register(OSSocket sockfd, Plug plug) { Actual_Socket ret; /* * Create Socket structure. */ ret = snew(struct Socket_tag); ret->fn = &tcp_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->oobpending = FALSE; ret->listener = 0; ret->addr = NULL; ret->s = sockfd; if (ret->s < 0) { ret->error = strerror(errno); return (Socket) ret; } ret->oobinline = 0; uxsel_tell(ret); add234(sktree, ret); return (Socket) ret; } static int try_connect(Actual_Socket sock) { int s; #ifndef NO_IPV6 struct sockaddr_in6 a6; #endif struct sockaddr_in a; struct sockaddr_un au; const struct sockaddr *sa; int err = 0; short localport; int fl, salen; if (sock->s >= 0) close(sock->s); plug_log(sock->plug, 0, sock->addr, sock->port, NULL, 0); /* * Open socket. */ assert(sock->addr->family != AF_UNSPEC); s = socket(sock->addr->family, SOCK_STREAM, 0); sock->s = s; if (s < 0) { err = errno; goto ret; } if (sock->oobinline) { int b = TRUE; setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (void *) &b, sizeof(b)); } if (sock->nodelay) { int b = TRUE; setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (void *) &b, sizeof(b)); } if (sock->keepalive) { int b = TRUE; setsockopt(s, SOL_SOCKET, SO_KEEPALIVE, (void *) &b, sizeof(b)); } /* * Bind to local address. */ if (sock->privport) localport = 1023; /* count from 1023 downwards */ else localport = 0; /* just use port 0 (ie kernel picks) */ /* BSD IP stacks need sockaddr_in zeroed before filling in */ memset(&a,'\0',sizeof(struct sockaddr_in)); #ifndef NO_IPV6 memset(&a6,'\0',sizeof(struct sockaddr_in6)); #endif /* We don't try to bind to a local address for UNIX domain sockets. (Why * do we bother doing the bind when localport == 0 anyway?) */ if(sock->addr->family != AF_UNIX) { /* Loop round trying to bind */ while (1) { int retcode; #ifndef NO_IPV6 if (sock->addr->family == AF_INET6) { /* XXX use getaddrinfo to get a local address? */ a6.sin6_family = AF_INET6; a6.sin6_addr = in6addr_any; a6.sin6_port = htons(localport); retcode = bind(s, (struct sockaddr *) &a6, sizeof(a6)); } else #endif { assert(sock->addr->family == AF_INET); a.sin_family = AF_INET; a.sin_addr.s_addr = htonl(INADDR_ANY); a.sin_port = htons(localport); retcode = bind(s, (struct sockaddr *) &a, sizeof(a)); } if (retcode >= 0) { err = 0; break; /* done */ } else { err = errno; if (err != EADDRINUSE) /* 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) goto ret; } /* * Connect to remote address. */ switch(sock->addr->family) { #ifndef NO_IPV6 case AF_INET: /* XXX would be better to have got getaddrinfo() to fill in the port. */ ((struct sockaddr_in *)sock->addr->ai->ai_addr)->sin_port = htons(sock->port); sa = (const struct sockaddr *)sock->addr->ai->ai_addr; salen = sock->addr->ai->ai_addrlen; break; case AF_INET6: ((struct sockaddr_in *)sock->addr->ai->ai_addr)->sin_port = htons(sock->port); sa = (const struct sockaddr *)sock->addr->ai->ai_addr; salen = sock->addr->ai->ai_addrlen; break; #else case AF_INET: a.sin_family = AF_INET; a.sin_addr.s_addr = htonl(sock->addr->addresses[sock->addr->curraddr]); a.sin_port = htons((short) sock->port); sa = (const struct sockaddr *)&a; salen = sizeof a; break; #endif case AF_UNIX: assert(sock->port == 0); /* to catch confused people */ assert(strlen(sock->addr->hostname) < sizeof au.sun_path); memset(&au, 0, sizeof au); au.sun_family = AF_UNIX; strcpy(au.sun_path, sock->addr->hostname); sa = (const struct sockaddr *)&au; salen = sizeof au; break; default: assert(0 && "unknown address family"); } fl = fcntl(s, F_GETFL); if (fl != -1) fcntl(s, F_SETFL, fl | O_NONBLOCK); if ((connect(s, sa, salen)) < 0) { if ( errno != EINPROGRESS ) { err = errno; goto ret; } } else { /* * If we _don't_ get EWOULDBLOCK, the connect has completed * and we should set the socket as connected and writable. */ sock->connected = 1; sock->writable = 1; } uxsel_tell(sock); add234(sktree, sock); ret: if (err) plug_log(sock->plug, 1, sock->addr, sock->port, strerror(err), err); return err; } Socket sk_new(SockAddr addr, int port, int privport, int oobinline, int nodelay, int keepalive, Plug plug) { Actual_Socket ret; int err; /* * Create Socket structure. */ ret = snew(struct Socket_tag); ret->fn = &tcp_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; ret->oobpending = FALSE; ret->listener = 0; ret->addr = addr; ret->s = -1; ret->oobinline = oobinline; ret->nodelay = nodelay; ret->keepalive = keepalive; ret->privport = privport; ret->port = port; err = 0; do { err = try_connect(ret); } while (err && sk_nextaddr(ret->addr)); if (err) ret->error = strerror(err); return (Socket) ret; } Socket sk_newlistener(char *srcaddr, int port, Plug plug, int local_host_only, int address_family) { int s; #ifndef NO_IPV6 struct addrinfo hints, *ai; char portstr[6]; struct sockaddr_in6 a6; #endif struct sockaddr *addr; int addrlen; struct sockaddr_in a; Actual_Socket ret; int retcode; int on = 1; /* * Create Socket structure. */ ret = snew(struct Socket_tag); ret->fn = &tcp_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; ret->oobpending = FALSE; ret->listener = 1; ret->addr = NULL; /* * Translate address_family from platform-independent constants * into local reality. */ address_family = (address_family == ADDRTYPE_IPV4 ? AF_INET : address_family == ADDRTYPE_IPV6 ? AF_INET6 : AF_UNSPEC); #ifndef NO_IPV6 /* Let's default to IPv6. * If the stack doesn't support IPv6, we will fall back to IPv4. */ if (address_family == AF_UNSPEC) address_family = AF_INET6; #else /* No other choice, default to IPv4 */ if (address_family == AF_UNSPEC) address_family = AF_INET; #endif /* * Open socket. */ s = socket(address_family, SOCK_STREAM, 0); /* If the host doesn't support IPv6 try fallback to IPv4. */ if (s < 0 && address_family == AF_INET6) { address_family = AF_INET; s = socket(address_family, SOCK_STREAM, 0); } if (s < 0) { ret->error = strerror(errno); return (Socket) ret; } ret->oobinline = 0; setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on)); retcode = -1; addr = NULL; addrlen = -1; /* placate optimiser */ if (srcaddr != NULL) { #ifndef NO_IPV6 hints.ai_flags = AI_NUMERICHOST; hints.ai_family = address_family; hints.ai_socktype = 0; hints.ai_protocol = 0; hints.ai_addrlen = 0; hints.ai_addr = NULL; hints.ai_canonname = NULL; hints.ai_next = NULL; sprintf(portstr, "%d", port); retcode = getaddrinfo(srcaddr, portstr, &hints, &ai); if (retcode == 0) { addr = ai->ai_addr; addrlen = ai->ai_addrlen; } #else memset(&a,'\0',sizeof(struct sockaddr_in)); a.sin_family = AF_INET; a.sin_port = htons(port); a.sin_addr.s_addr = inet_addr(srcaddr); if (a.sin_addr.s_addr != (in_addr_t)(-1)) { /* Override localhost_only with specified listen addr. */ ret->localhost_only = ipv4_is_loopback(a.sin_addr); got_addr = 1; } addr = (struct sockaddr *)a; addrlen = sizeof(a); retcode = 0; #endif } if (retcode != 0) { #ifndef NO_IPV6 if (address_family == AF_INET6) { memset(&a6,'\0',sizeof(struct sockaddr_in6)); a6.sin6_family = AF_INET6; a6.sin6_port = htons(port); if (local_host_only) a6.sin6_addr = in6addr_loopback; else a6.sin6_addr = in6addr_any; addr = (struct sockaddr *)&a6; addrlen = sizeof(a6); } else #endif { memset(&a,'\0',sizeof(struct sockaddr_in)); a.sin_family = AF_INET; a.sin_port = htons(port); if (local_host_only) a.sin_addr.s_addr = htonl(INADDR_LOOPBACK); else a.sin_addr.s_addr = htonl(INADDR_ANY); addr = (struct sockaddr *)&a; addrlen = sizeof(a); } } retcode = bind(s, addr, addrlen); if (retcode < 0) { close(s); ret->error = strerror(errno); return (Socket) ret; } if (listen(s, SOMAXCONN) < 0) { close(s); ret->error = strerror(errno); return (Socket) ret; } ret->s = s; uxsel_tell(ret); add234(sktree, ret); return (Socket) ret; } static void sk_tcp_close(Socket sock) { Actual_Socket s = (Actual_Socket) sock; uxsel_del(s->s); del234(sktree, s); close(s->s); if (s->addr) sk_addr_free(s->addr); sfree(s); } int sk_getxdmdata(void *sock, unsigned long *ip, int *port) { Actual_Socket s = (Actual_Socket) sock; struct sockaddr_in addr; socklen_t addrlen; /* * We must check that this socket really _is_ an Actual_Socket. */ if (s->fn != &tcp_fn_table) return 0; /* failure */ addrlen = sizeof(addr); if (getsockname(s->s, (struct sockaddr *)&addr, &addrlen) < 0) return 0; switch(addr.sin_family) { case AF_INET: *ip = ntohl(addr.sin_addr.s_addr); *port = ntohs(addr.sin_port); break; case AF_UNIX: /* * For a Unix socket, we return 0xFFFFFFFF for the IP address and * our current pid for the port. Bizarre, but such is life. */ *ip = ntohl(0xFFFFFFFF); *port = getpid(); break; /* XXX IPV6 */ default: return 0; } return 1; } /* * 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; int 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 ? errno : 0); if (err == EWOULDBLOCK) { /* * Perfectly normal: we've sent all we can for the moment. */ s->writable = FALSE; return; } else if (nsent == 0 || err == ECONNABORTED || err == ECONNRESET) { /* * 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 { /* We're inside the Unix frontend here, so we know * that the frontend handle is unnecessary. */ logevent(NULL, strerror(err)); fatalbox("%s", strerror(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); } } } uxsel_tell(s); } static int sk_tcp_write(Socket sock, const 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); /* * Update the select() status to correctly reflect whether or * not we should be selecting for write. */ uxsel_tell(s); return bufchain_size(&s->output_data); } static int sk_tcp_write_oob(Socket sock, const 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); /* * Update the select() status to correctly reflect whether or * not we should be selecting for write. */ uxsel_tell(s); return s->sending_oob; } static int net_select_result(int fd, int event) { int ret; char buf[20480]; /* nice big buffer for plenty of speed */ Actual_Socket s; u_long atmark; /* Find the Socket structure */ s = find234(sktree, &fd, cmpforsearch); if (!s) return 1; /* boggle */ noise_ultralight(event); switch (event) { case 4: /* exceptional */ if (!s->oobinline) { /* * On a non-oobinline socket, this 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) { const char *str = (ret == 0 ? "Internal networking trouble" : strerror(errno)); /* We're inside the Unix frontend here, so we know * that the frontend handle is unnecessary. */ logevent(NULL, str); fatalbox("%s", str); } else { /* * Receiving actual data on a socket means we can * stop falling back through the candidate * addresses to connect to. */ if (s->addr) { sk_addr_free(s->addr); s->addr = NULL; } return plug_receive(s->plug, 2, buf, ret); } break; } /* * If we reach here, this is an oobinline socket, which * means we should set s->oobpending and then deal with it * when we get called for the readability event (which * should also occur). */ s->oobpending = TRUE; break; case 1: /* readable; also acceptance */ if (s->listener) { /* * On a listening socket, the readability event means a * connection is ready to be accepted. */ struct sockaddr_in isa; int addrlen = sizeof(struct sockaddr_in); int t; /* socket of connection */ memset(&isa, 0, sizeof(struct sockaddr_in)); t = accept(s->s,(struct sockaddr *)&isa,(socklen_t *) &addrlen); if (t < 0) { break; } if (s->localhost_only && !ipv4_is_loopback(isa.sin_addr)) { close(t); /* someone let nonlocal through?! */ } else if (plug_accepting(s->plug, t)) { close(t); /* denied or error */ } break; } /* * If we reach here, this is not a listening socket, so * readability really means readability. */ /* 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 && s->oobpending) { atmark = 1; if (ioctl(s->s, SIOCATMARK, &atmark) == 0 && atmark) s->oobpending = FALSE; /* clear this indicator */ } else atmark = 1; ret = recv(s->s, buf, s->oobpending ? 1 : sizeof(buf), 0); noise_ultralight(ret); if (ret < 0) { if (errno == EWOULDBLOCK) { break; } } if (ret < 0) { /* * An error at this point _might_ be an error reported * by a non-blocking connect(). So before we return a * panic status to the user, let's just see whether * that's the case. */ int err = errno; if (s->addr) { plug_log(s->plug, 1, s->addr, s->port, strerror(err), err); while (s->addr && sk_nextaddr(s->addr)) { err = try_connect(s); } } if (err != 0) return plug_closing(s->plug, strerror(err), err, 0); } else if (0 == ret) { return plug_closing(s->plug, NULL, 0, 0); } else { /* * Receiving actual data on a socket means we can * stop falling back through the candidate * addresses to connect to. */ if (s->addr) { sk_addr_free(s->addr); s->addr = NULL; } return plug_receive(s->plug, atmark ? 0 : 1, buf, ret); } break; case 2: /* writable */ if (!s->connected) { /* * select() reports a socket as _writable_ when an * asynchronous connection is completed. */ s->connected = s->writable = 1; uxsel_tell(s); break; } else { 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; } 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, strerror(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. */ const char *sk_addr_error(SockAddr addr) { return addr->error; } static const 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; uxsel_tell(s); } static void uxsel_tell(Actual_Socket s) { int rwx = 0; if (!s->connected) rwx |= 2; /* write == connect */ if (s->connected && !s->frozen) rwx |= 1 | 4; /* read, except */ if (bufchain_size(&s->output_data)) rwx |= 2; /* write */ if (s->listener) rwx |= 1; /* read == accept */ uxsel_set(s->s, rwx, net_select_result); } int net_service_lookup(char *service) { struct servent *se; se = getservbyname(service, NULL); if (se != NULL) return ntohs(se->s_port); else return 0; } SockAddr platform_get_x11_unix_address(int displaynum, char **canonicalname) { SockAddr ret = snew(struct SockAddr_tag); int n; memset(ret, 0, sizeof *ret); ret->family = AF_UNIX; n = snprintf(ret->hostname, sizeof ret->hostname, "%s%d", X11_UNIX_PATH, displaynum); if(n < 0) ret->error = "snprintf failed"; else if(n >= sizeof ret->hostname) ret->error = "X11 UNIX name too long"; else *canonicalname = dupstr(ret->hostname); #ifndef NO_IPV6 ret->ais = NULL; #else ret->addresses = NULL; #endif return ret; }