/* * Unix networking abstraction. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "putty.h" #include "network.h" #include "tree234.h" /* Solaris needs for SIOCATMARK. */ #ifndef SIOCATMARK #include #endif #ifndef X11_UNIX_PATH # define X11_UNIX_PATH "/tmp/.X11-unix/X" #endif /* * Access to sockaddr types without breaking C strict aliasing rules. */ union sockaddr_union { struct sockaddr_storage storage; struct sockaddr sa; struct sockaddr_in sin; #ifndef NO_IPV6 struct sockaddr_in6 sin6; #endif struct sockaddr_un su; }; /* * Mutable state that goes with a SockAddr: stores information * about where in the list of candidate IP(v*) addresses we've * currently got to. */ typedef struct SockAddrStep_tag SockAddrStep; struct SockAddrStep_tag { #ifndef NO_IPV6 struct addrinfo *ai; /* steps along addr->ais */ #endif int curraddr; }; typedef struct NetSocket NetSocket; struct NetSocket { const char *error; int s; Plug *plug; bufchain output_data; int connected; /* irrelevant for listening sockets */ int writable; int frozen; /* this causes readability notifications to be ignored */ int localhost_only; /* for listening sockets */ char oobdata[1]; int sending_oob; int oobpending; /* is there OOB data available to read? */ int oobinline; enum { EOF_NO, EOF_PENDING, EOF_SENT } outgoingeof; int incomingeof; int pending_error; /* in case send() returns error */ int listener; int nodelay, keepalive; /* for connect()-type sockets */ int privport, port; /* and again */ SockAddr *addr; SockAddrStep step; /* * We sometimes need pairs of Socket structures to be linked: * if we are listening on the same IPv6 and v4 port, for * example. So here we define `parent' and `child' pointers to * track this link. */ NetSocket *parent, *child; Socket sock; }; struct SockAddr { int refcount; const char *error; enum { UNRESOLVED, UNIX, IP } superfamily; #ifndef NO_IPV6 struct addrinfo *ais; /* Addresses IPv6 style. */ #else unsigned long *addresses; /* Addresses IPv4 style. */ int naddresses; #endif char hostname[512]; /* Store an unresolved host name. */ }; /* * 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. */ #ifndef NO_IPV6 #define SOCKADDR_FAMILY(addr, step) \ ((addr)->superfamily == UNRESOLVED ? AF_UNSPEC : \ (addr)->superfamily == UNIX ? AF_UNIX : \ (step).ai ? (step).ai->ai_family : AF_INET) #else /* Here we gratuitously reference 'step' to avoid gcc warnings about * 'set but not used' when compiling -DNO_IPV6 */ #define SOCKADDR_FAMILY(addr, step) \ ((addr)->superfamily == UNRESOLVED ? AF_UNSPEC : \ (addr)->superfamily == UNIX ? AF_UNIX : \ (step).curraddr ? AF_INET : AF_INET) #endif /* * Start a SockAddrStep structure to step through multiple * addresses. */ #ifndef NO_IPV6 #define START_STEP(addr, step) \ ((step).ai = (addr)->ais, (step).curraddr = 0) #else #define START_STEP(addr, step) \ ((step).curraddr = 0) #endif static tree234 *sktree; static void uxsel_tell(NetSocket *s); static int cmpfortree(void *av, void *bv) { NetSocket *a = (NetSocket *) av, *b = (NetSocket *) bv; int as = a->s, bs = b->s; if (as < bs) return -1; if (as > bs) return +1; if (a < b) return -1; if (a > b) return +1; return 0; } static int cmpforsearch(void *av, void *bv) { NetSocket *b = (NetSocket *) 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) { NetSocket *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(SockAddr); #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(SockAddr)); ret->superfamily = UNRESOLVED; *realhost = '\0'; ret->error = NULL; ret->refcount = 1; #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; { char *trimmed_host = host_strduptrim(host); /* strip [] on literals */ err = getaddrinfo(trimmed_host, NULL, &hints, &ret->ais); sfree(trimmed_host); } if (err != 0) { ret->error = gai_strerror(err); return ret; } ret->superfamily = IP; *realhost = '\0'; if (ret->ais->ai_canonname != NULL) strncat(realhost, ret->ais->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->superfamily == UNRESOLVED) { /*debug(("Resolving \"%s\" with gethostbyname() (IPv4 only)...\n", host)); */ if ( (h = gethostbyname(host)) ) ret->superfamily = IP; } if (ret->superfamily == UNRESOLVED) { 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->superfamily = IP; strncpy(realhost, host, sizeof(realhost)); ret->addresses = snew(unsigned long); ret->naddresses = 1; ret->addresses[0] = ntohl(a); } #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(SockAddr); ret->error = NULL; ret->superfamily = UNRESOLVED; 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 ret->refcount = 1; return ret; } static int sk_nextaddr(SockAddr *addr, SockAddrStep *step) { #ifndef NO_IPV6 if (step->ai && step->ai->ai_next) { step->ai = step->ai->ai_next; return TRUE; } else return FALSE; #else if (step->curraddr+1 < addr->naddresses) { step->curraddr++; return TRUE; } else { return FALSE; } #endif } void sk_getaddr(SockAddr *addr, char *buf, int buflen) { if (addr->superfamily == UNRESOLVED || addr->superfamily == UNIX) { strncpy(buf, addr->hostname, buflen); buf[buflen-1] = '\0'; } else { #ifndef NO_IPV6 if (getnameinfo(addr->ais->ai_addr, addr->ais->ai_addrlen, buf, buflen, NULL, 0, NI_NUMERICHOST) != 0) { buf[0] = '\0'; strncat(buf, "", buflen - 1); } #else struct in_addr a; SockAddrStep step; START_STEP(addr, step); assert(SOCKADDR_FAMILY(addr, step) == AF_INET); a.s_addr = htonl(addr->addresses[0]); strncpy(buf, inet_ntoa(a), buflen); buf[buflen-1] = '\0'; #endif } } /* * This constructs a SockAddr that points at one specific sub-address * of a parent SockAddr. The returned SockAddr does not own all its * own memory: it points into the old one's data structures, so it * MUST NOT be used after the old one is freed, and it MUST NOT be * passed to sk_addr_free. (The latter is why it's returned by value * rather than dynamically allocated - that should clue in anyone * writing a call to it that something is weird about it.) */ static SockAddr sk_extractaddr_tmp( SockAddr *addr, const SockAddrStep *step) { SockAddr toret; toret = *addr; /* structure copy */ toret.refcount = 1; if (addr->superfamily == IP) { #ifndef NO_IPV6 toret.ais = step->ai; #else assert(SOCKADDR_FAMILY(addr, *step) == AF_INET); toret.addresses += step->curraddr; #endif } return toret; } int sk_addr_needs_port(SockAddr *addr) { if (addr->superfamily == UNRESOLVED || addr->superfamily == UNIX) { return FALSE; } else { return TRUE; } } int sk_hostname_is_local(const char *name) { return !strcmp(name, "localhost") || !strcmp(name, "::1") || !strncmp(name, "127.", 4); } #define ipv4_is_loopback(addr) \ (((addr).s_addr & htonl(0xff000000)) == htonl(0x7f000000)) static int sockaddr_is_loopback(struct sockaddr *sa) { union sockaddr_union *u = (union sockaddr_union *)sa; switch (u->sa.sa_family) { case AF_INET: return ipv4_is_loopback(u->sin.sin_addr); #ifndef NO_IPV6 case AF_INET6: return IN6_IS_ADDR_LOOPBACK(&u->sin6.sin6_addr); #endif case AF_UNIX: return TRUE; default: return FALSE; } } int sk_address_is_local(SockAddr *addr) { if (addr->superfamily == UNRESOLVED) return 0; /* we don't know; assume not */ else if (addr->superfamily == UNIX) return 1; else { #ifndef NO_IPV6 return sockaddr_is_loopback(addr->ais->ai_addr); #else struct in_addr a; SockAddrStep step; START_STEP(addr, step); assert(SOCKADDR_FAMILY(addr, step) == AF_INET); a.s_addr = htonl(addr->addresses[0]); return ipv4_is_loopback(a); #endif } } int sk_address_is_special_local(SockAddr *addr) { return addr->superfamily == UNIX; } int sk_addrtype(SockAddr *addr) { SockAddrStep step; int family; START_STEP(addr, step); family = SOCKADDR_FAMILY(addr, step); return (family == AF_INET ? ADDRTYPE_IPV4 : #ifndef NO_IPV6 family == AF_INET6 ? ADDRTYPE_IPV6 : #endif ADDRTYPE_NAME); } void sk_addrcopy(SockAddr *addr, char *buf) { SockAddrStep step; int family; START_STEP(addr, step); family = SOCKADDR_FAMILY(addr, step); #ifndef NO_IPV6 if (family == AF_INET) memcpy(buf, &((struct sockaddr_in *)step.ai->ai_addr)->sin_addr, sizeof(struct in_addr)); else if (family == AF_INET6) memcpy(buf, &((struct sockaddr_in6 *)step.ai->ai_addr)->sin6_addr, sizeof(struct in6_addr)); else assert(FALSE); #else struct in_addr a; assert(family == AF_INET); a.s_addr = htonl(addr->addresses[step.curraddr]); memcpy(buf, (char*) &a.s_addr, 4); #endif } void sk_addr_free(SockAddr *addr) { if (--addr->refcount > 0) return; #ifndef NO_IPV6 if (addr->ais != NULL) freeaddrinfo(addr->ais); #else sfree(addr->addresses); #endif sfree(addr); } SockAddr *sk_addr_dup(SockAddr *addr) { addr->refcount++; return addr; } static Plug *sk_net_plug(Socket *sock, Plug *p) { NetSocket *s = container_of(sock, NetSocket, sock); Plug *ret = s->plug; if (p) s->plug = p; return ret; } static void sk_net_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_net_close(Socket *s); static int sk_net_write(Socket *s, const void *data, int len); static int sk_net_write_oob(Socket *s, const void *data, int len); static void sk_net_write_eof(Socket *s); static void sk_net_set_frozen(Socket *s, int is_frozen); static SocketPeerInfo *sk_net_peer_info(Socket *s); static const char *sk_net_socket_error(Socket *s); static struct SocketVtable NetSocket_sockvt = { sk_net_plug, sk_net_close, sk_net_write, sk_net_write_oob, sk_net_write_eof, sk_net_flush, sk_net_set_frozen, sk_net_socket_error, sk_net_peer_info, }; static Socket *sk_net_accept(accept_ctx_t ctx, Plug *plug) { int sockfd = ctx.i; NetSocket *ret; /* * Create NetSocket structure. */ ret = snew(NetSocket); ret->sock.vt = &NetSocket_sockvt; 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->localhost_only = 0; /* unused, but best init anyway */ ret->pending_error = 0; ret->oobpending = FALSE; ret->outgoingeof = EOF_NO; ret->incomingeof = FALSE; ret->listener = 0; ret->parent = ret->child = NULL; ret->addr = NULL; ret->connected = 1; ret->s = sockfd; if (ret->s < 0) { ret->error = strerror(errno); return &ret->sock; } ret->oobinline = 0; uxsel_tell(ret); add234(sktree, ret); return &ret->sock; } static int try_connect(NetSocket *sock) { int s; union sockaddr_union u; const union sockaddr_union *sa; int err = 0; short localport; int salen, family; /* * Remove the socket from the tree before we overwrite its * internal socket id, because that forms part of the tree's * sorting criterion. We'll add it back before exiting this * function, whether we changed anything or not. */ del234(sktree, sock); if (sock->s >= 0) close(sock->s); { SockAddr thisaddr = sk_extractaddr_tmp( sock->addr, &sock->step); plug_log(sock->plug, 0, &thisaddr, sock->port, NULL, 0); } /* * Open socket. */ family = SOCKADDR_FAMILY(sock->addr, sock->step); assert(family != AF_UNSPEC); s = socket(family, SOCK_STREAM, 0); sock->s = s; if (s < 0) { err = errno; goto ret; } cloexec(s); if (sock->oobinline) { int b = TRUE; if (setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (void *) &b, sizeof(b)) < 0) { err = errno; close(s); goto ret; } } if (sock->nodelay) { int b = TRUE; if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (void *) &b, sizeof(b)) < 0) { err = errno; close(s); goto ret; } } if (sock->keepalive) { int b = TRUE; if (setsockopt(s, SOL_SOCKET, SO_KEEPALIVE, (void *) &b, sizeof(b)) < 0) { err = errno; close(s); goto ret; } } /* * 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(&u,'\0',sizeof(u)); /* 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 (family != AF_UNIX) { /* Loop round trying to bind */ while (1) { int retcode; #ifndef NO_IPV6 if (family == AF_INET6) { /* XXX use getaddrinfo to get a local address? */ u.sin6.sin6_family = AF_INET6; u.sin6.sin6_addr = in6addr_any; u.sin6.sin6_port = htons(localport); retcode = bind(s, &u.sa, sizeof(u.sin6)); } else #endif { assert(family == AF_INET); u.sin.sin_family = AF_INET; u.sin.sin_addr.s_addr = htonl(INADDR_ANY); u.sin.sin_port = htons(localport); retcode = bind(s, &u.sa, sizeof(u.sin)); } 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(family) { #ifndef NO_IPV6 case AF_INET: /* XXX would be better to have got getaddrinfo() to fill in the port. */ ((struct sockaddr_in *)sock->step.ai->ai_addr)->sin_port = htons(sock->port); sa = (const union sockaddr_union *)sock->step.ai->ai_addr; salen = sock->step.ai->ai_addrlen; break; case AF_INET6: ((struct sockaddr_in *)sock->step.ai->ai_addr)->sin_port = htons(sock->port); sa = (const union sockaddr_union *)sock->step.ai->ai_addr; salen = sock->step.ai->ai_addrlen; break; #else case AF_INET: u.sin.sin_family = AF_INET; u.sin.sin_addr.s_addr = htonl(sock->addr->addresses[sock->step.curraddr]); u.sin.sin_port = htons((short) sock->port); sa = &u; salen = sizeof u.sin; break; #endif case AF_UNIX: assert(sock->port == 0); /* to catch confused people */ assert(strlen(sock->addr->hostname) < sizeof u.su.sun_path); u.su.sun_family = AF_UNIX; strcpy(u.su.sun_path, sock->addr->hostname); sa = &u; salen = sizeof u.su; break; default: assert(0 && "unknown address family"); exit(1); /* XXX: GCC doesn't understand assert() on some systems. */ } nonblock(s); if ((connect(s, &(sa->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); ret: /* * No matter what happened, put the socket back in the tree. */ add234(sktree, sock); if (err) { SockAddr thisaddr = sk_extractaddr_tmp( sock->addr, &sock->step); plug_log(sock->plug, 1, &thisaddr, sock->port, strerror(err), err); } return err; } Socket *sk_new(SockAddr *addr, int port, int privport, int oobinline, int nodelay, int keepalive, Plug *plug) { NetSocket *ret; int err; /* * Create NetSocket structure. */ ret = snew(NetSocket); ret->sock.vt = &NetSocket_sockvt; 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->localhost_only = 0; /* unused, but best init anyway */ ret->pending_error = 0; ret->parent = ret->child = NULL; ret->oobpending = FALSE; ret->outgoingeof = EOF_NO; ret->incomingeof = FALSE; ret->listener = 0; ret->addr = addr; START_STEP(ret->addr, ret->step); 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, &ret->step)); if (err) ret->error = strerror(err); return &ret->sock; } Socket *sk_newlistener(const char *srcaddr, int port, Plug *plug, int local_host_only, int orig_address_family) { int s; #ifndef NO_IPV6 struct addrinfo hints, *ai = NULL; char portstr[6]; #endif union sockaddr_union u; union sockaddr_union *addr; int addrlen; NetSocket *ret; int retcode; int address_family; int on = 1; /* * Create NetSocket structure. */ ret = snew(NetSocket); ret->sock.vt = &NetSocket_sockvt; 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->localhost_only = local_host_only; ret->pending_error = 0; ret->parent = ret->child = NULL; ret->oobpending = FALSE; ret->outgoingeof = EOF_NO; ret->incomingeof = FALSE; ret->listener = 1; ret->addr = NULL; ret->s = -1; /* * Translate address_family from platform-independent constants * into local reality. */ address_family = (orig_address_family == ADDRTYPE_IPV4 ? AF_INET : #ifndef NO_IPV6 orig_address_family == ADDRTYPE_IPV6 ? AF_INET6 : #endif 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); #ifndef NO_IPV6 /* 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); } #endif if (s < 0) { ret->error = strerror(errno); return &ret->sock; } cloexec(s); ret->oobinline = 0; if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on)) < 0) { ret->error = strerror(errno); close(s); return &ret->sock; } 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 = SOCK_STREAM; hints.ai_protocol = 0; hints.ai_addrlen = 0; hints.ai_addr = NULL; hints.ai_canonname = NULL; hints.ai_next = NULL; assert(port >= 0 && port <= 99999); sprintf(portstr, "%d", port); { char *trimmed_addr = host_strduptrim(srcaddr); retcode = getaddrinfo(trimmed_addr, portstr, &hints, &ai); sfree(trimmed_addr); } if (retcode == 0) { addr = (union sockaddr_union *)ai->ai_addr; addrlen = ai->ai_addrlen; } #else memset(&u,'\0',sizeof u); u.sin.sin_family = AF_INET; u.sin.sin_port = htons(port); u.sin.sin_addr.s_addr = inet_addr(srcaddr); if (u.sin.sin_addr.s_addr != (in_addr_t)(-1)) { /* Override localhost_only with specified listen addr. */ ret->localhost_only = ipv4_is_loopback(u.sin.sin_addr); } addr = &u; addrlen = sizeof(u.sin); retcode = 0; #endif } if (retcode != 0) { memset(&u,'\0',sizeof u); #ifndef NO_IPV6 if (address_family == AF_INET6) { u.sin6.sin6_family = AF_INET6; u.sin6.sin6_port = htons(port); if (local_host_only) u.sin6.sin6_addr = in6addr_loopback; else u.sin6.sin6_addr = in6addr_any; addr = &u; addrlen = sizeof(u.sin6); } else #endif { u.sin.sin_family = AF_INET; u.sin.sin_port = htons(port); if (local_host_only) u.sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK); else u.sin.sin_addr.s_addr = htonl(INADDR_ANY); addr = &u; addrlen = sizeof(u.sin); } } retcode = bind(s, &addr->sa, addrlen); #ifndef NO_IPV6 if (ai) freeaddrinfo(ai); #endif if (retcode < 0) { close(s); ret->error = strerror(errno); return &ret->sock; } if (listen(s, SOMAXCONN) < 0) { close(s); ret->error = strerror(errno); return &ret->sock; } #ifndef NO_IPV6 /* * If we were given ADDRTYPE_UNSPEC, we must also create an * IPv4 listening socket and link it to this one. */ if (address_family == AF_INET6 && orig_address_family == ADDRTYPE_UNSPEC) { NetSocket *other; other = container_of( sk_newlistener(srcaddr, port, plug, local_host_only, ADDRTYPE_IPV4), NetSocket, sock); if (other) { if (!other->error) { other->parent = ret; ret->child = other; } else { /* If we couldn't create a listening socket on IPv4 as well * as IPv6, we must return an error overall. */ close(s); sfree(ret); return &other->sock; } } } #endif ret->s = s; uxsel_tell(ret); add234(sktree, ret); return &ret->sock; } static void sk_net_close(Socket *sock) { NetSocket *s = container_of(sock, NetSocket, sock); if (s->child) sk_net_close(&s->child->sock); del234(sktree, s); if (s->s >= 0) { uxsel_del(s->s); close(s->s); } if (s->addr) sk_addr_free(s->addr); sfree(s); } void *sk_getxdmdata(Socket *sock, int *lenp) { NetSocket *s; union sockaddr_union u; socklen_t addrlen; char *buf; static unsigned int unix_addr = 0xFFFFFFFF; /* * We must check that this socket really _is_ a NetSocket before * downcasting it. */ if (sock->vt != &NetSocket_sockvt) return NULL; /* failure */ s = container_of(sock, NetSocket, sock); addrlen = sizeof(u); if (getsockname(s->s, &u.sa, &addrlen) < 0) return NULL; switch(u.sa.sa_family) { case AF_INET: *lenp = 6; buf = snewn(*lenp, char); PUT_32BIT_MSB_FIRST(buf, ntohl(u.sin.sin_addr.s_addr)); PUT_16BIT_MSB_FIRST(buf+4, ntohs(u.sin.sin_port)); break; #ifndef NO_IPV6 case AF_INET6: *lenp = 6; buf = snewn(*lenp, char); if (IN6_IS_ADDR_V4MAPPED(&u.sin6.sin6_addr)) { memcpy(buf, u.sin6.sin6_addr.s6_addr + 12, 4); PUT_16BIT_MSB_FIRST(buf+4, ntohs(u.sin6.sin6_port)); } else /* This is stupid, but it's what XLib does. */ memset(buf, 0, 6); break; #endif case AF_UNIX: *lenp = 6; buf = snewn(*lenp, char); PUT_32BIT_MSB_FIRST(buf, unix_addr--); PUT_16BIT_MSB_FIRST(buf+4, getpid()); break; /* XXX IPV6 */ default: return NULL; } return buf; } /* * Deal with socket errors detected in try_send(). */ static void socket_error_callback(void *vs) { NetSocket *s = (NetSocket *)vs; /* * Just in case other socket work has caused this socket to vanish * or become somehow non-erroneous before this callback arrived... */ if (!find234(sktree, s, NULL) || !s->pending_error) return; /* * An error has occurred on this socket. Pass it to the plug. */ plug_closing(s->plug, strerror(s->pending_error), s->pending_error, 0); } /* * The function which tries to send on a socket once it's deemed * writable. */ void try_send(NetSocket *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 { /* * 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; /* * Immediately cease selecting on this socket, so that * we don't tight-loop repeatedly trying to do * whatever it was that went wrong. */ uxsel_tell(s); /* * Arrange to be called back from the top level to * deal with the error condition on this socket. */ queue_toplevel_callback(socket_error_callback, s); return; } } 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); } } } /* * If we reach here, we've finished sending everything we might * have needed to send. Send EOF, if we need to. */ if (s->outgoingeof == EOF_PENDING) { shutdown(s->s, SHUT_WR); s->outgoingeof = EOF_SENT; } /* * Also update the select status, because we don't need to select * for writing any more. */ uxsel_tell(s); } static int sk_net_write(Socket *sock, const void *buf, int len) { NetSocket *s = container_of(sock, NetSocket, sock); assert(s->outgoingeof == EOF_NO); /* * 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_net_write_oob(Socket *sock, const void *buf, int len) { NetSocket *s = container_of(sock, NetSocket, sock); assert(s->outgoingeof == EOF_NO); /* * 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 void sk_net_write_eof(Socket *sock) { NetSocket *s = container_of(sock, NetSocket, sock); assert(s->outgoingeof == EOF_NO); /* * Mark the socket as pending outgoing EOF. */ s->outgoingeof = EOF_PENDING; /* * 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); } static void net_select_result(int fd, int event) { int ret; char buf[20480]; /* nice big buffer for plenty of speed */ NetSocket *s; u_long atmark; /* Find the Socket structure */ s = find234(sktree, &fd, cmpforsearch); if (!s) return; /* 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) { plug_closing(s->plug, ret == 0 ? "Internal networking trouble" : strerror(errno), errno, 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; } 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. */ union sockaddr_union su; socklen_t addrlen = sizeof(su); accept_ctx_t actx; int t; /* socket of connection */ memset(&su, 0, addrlen); t = accept(s->s, &su.sa, &addrlen); if (t < 0) { break; } nonblock(t); actx.i = t; if ((!s->addr || s->addr->superfamily != UNIX) && s->localhost_only && !sockaddr_is_loopback(&su.sa)) { close(t); /* someone let nonlocal through?! */ } else if (plug_accepting(s->plug, sk_net_accept, actx)) { 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) 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) { plug_closing(s->plug, strerror(errno), errno, 0); } else if (0 == ret) { s->incomingeof = TRUE; /* stop trying to read now */ uxsel_tell(s); 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; } 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 connect() attempt either completes or * fails. So first we must find out which. */ { int err; socklen_t errlen = sizeof(err); char *errmsg = NULL; if (getsockopt(s->s, SOL_SOCKET, SO_ERROR, &err, &errlen)<0) { errmsg = dupprintf("getsockopt(SO_ERROR): %s", strerror(errno)); err = errno; /* got to put something in here */ } else if (err != 0) { errmsg = dupstr(strerror(err)); } if (errmsg) { /* * The asynchronous connection attempt failed. * Report the problem via plug_log, and try again * with the next candidate address, if we have * more than one. */ SockAddr thisaddr; assert(s->addr); thisaddr = sk_extractaddr_tmp(s->addr, &s->step); plug_log(s->plug, 1, &thisaddr, s->port, errmsg, err); while (err && s->addr && sk_nextaddr(s->addr, &s->step)) { err = try_connect(s); } if (err) { plug_closing(s->plug, strerror(err), err, 0); return; /* socket is now presumably defunct */ } if (!s->connected) return; /* another async attempt in progress */ } } /* * If we get here, we've managed to make a connection. */ if (s->addr) { sk_addr_free(s->addr); s->addr = NULL; } s->connected = s->writable = 1; uxsel_tell(s); } 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; } } /* * 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_net_socket_error(Socket *sock) { NetSocket *s = container_of(sock, NetSocket, sock); return s->error; } static void sk_net_set_frozen(Socket *sock, int is_frozen) { NetSocket *s = container_of(sock, NetSocket, sock); if (s->frozen == is_frozen) return; s->frozen = is_frozen; uxsel_tell(s); } static SocketPeerInfo *sk_net_peer_info(Socket *sock) { NetSocket *s = container_of(sock, NetSocket, sock); union sockaddr_union addr; socklen_t addrlen = sizeof(addr); #ifndef NO_IPV6 char buf[INET6_ADDRSTRLEN]; #endif SocketPeerInfo *pi; if (getpeername(s->s, &addr.sa, &addrlen) < 0) return NULL; pi = snew(SocketPeerInfo); pi->addressfamily = ADDRTYPE_UNSPEC; pi->addr_text = NULL; pi->port = -1; pi->log_text = NULL; if (addr.storage.ss_family == AF_INET) { pi->addressfamily = ADDRTYPE_IPV4; memcpy(pi->addr_bin.ipv4, &addr.sin.sin_addr, 4); pi->port = ntohs(addr.sin.sin_port); pi->addr_text = dupstr(inet_ntoa(addr.sin.sin_addr)); pi->log_text = dupprintf("%s:%d", pi->addr_text, pi->port); #ifndef NO_IPV6 } else if (addr.storage.ss_family == AF_INET6) { pi->addressfamily = ADDRTYPE_IPV6; memcpy(pi->addr_bin.ipv6, &addr.sin6.sin6_addr, 16); pi->port = ntohs(addr.sin6.sin6_port); pi->addr_text = dupstr( inet_ntop(AF_INET6, &addr.sin6.sin6_addr, buf, sizeof(buf))); pi->log_text = dupprintf("[%s]:%d", pi->addr_text, pi->port); #endif } else if (addr.storage.ss_family == AF_UNIX) { pi->addressfamily = ADDRTYPE_LOCAL; /* * For Unix sockets, the source address is unlikely to be * helpful, so we leave addr_txt NULL (and we certainly can't * fill in port, obviously). Instead, we try SO_PEERCRED and * try to get the source pid, and put that in the log text. */ int pid, uid, gid; if (so_peercred(s->s, &pid, &uid, &gid)) { char uidbuf[64], gidbuf[64]; sprintf(uidbuf, "%d", uid); sprintf(gidbuf, "%d", gid); struct passwd *pw = getpwuid(uid); struct group *gr = getgrgid(gid); pi->log_text = dupprintf("pid %d (%s:%s)", pid, pw ? pw->pw_name : uidbuf, gr ? gr->gr_name : gidbuf); } } else { sfree(pi); return NULL; } return pi; } static void uxsel_tell(NetSocket *s) { int rwx = 0; if (!s->pending_error) { if (s->listener) { rwx |= 1; /* read == accept */ } else { if (!s->connected) rwx |= 2; /* write == connect */ if (s->connected && !s->frozen && !s->incomingeof) rwx |= 1 | 4; /* read, except */ if (bufchain_size(&s->output_data)) rwx |= 2; /* write */ } } 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; } char *get_hostname(void) { int len = 128; char *hostname = NULL; do { len *= 2; hostname = sresize(hostname, len, char); if ((gethostname(hostname, len) < 0) && (errno != ENAMETOOLONG)) { sfree(hostname); hostname = NULL; break; } } while (strlen(hostname) >= len-1); return hostname; } SockAddr *platform_get_x11_unix_address(const char *sockpath, int displaynum) { SockAddr *ret = snew(SockAddr); int n; memset(ret, 0, sizeof *ret); ret->superfamily = UNIX; /* * In special circumstances (notably Mac OS X Leopard), we'll * have been passed an explicit Unix socket path. */ if (sockpath) { n = snprintf(ret->hostname, sizeof ret->hostname, "%s", sockpath); } else { 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"; #ifndef NO_IPV6 ret->ais = NULL; #else ret->addresses = NULL; ret->naddresses = 0; #endif ret->refcount = 1; return ret; } SockAddr *unix_sock_addr(const char *path) { SockAddr *ret = snew(SockAddr); int n; memset(ret, 0, sizeof *ret); ret->superfamily = UNIX; n = snprintf(ret->hostname, sizeof ret->hostname, "%s", path); if (n < 0) ret->error = "snprintf failed"; else if (n >= sizeof ret->hostname || n >= sizeof(((struct sockaddr_un *)0)->sun_path)) ret->error = "socket pathname too long"; #ifndef NO_IPV6 ret->ais = NULL; #else ret->addresses = NULL; ret->naddresses = 0; #endif ret->refcount = 1; return ret; } Socket *new_unix_listener(SockAddr *listenaddr, Plug *plug) { int s; union sockaddr_union u; union sockaddr_union *addr; int addrlen; NetSocket *ret; int retcode; /* * Create NetSocket structure. */ ret = snew(NetSocket); ret->sock.vt = &NetSocket_sockvt; 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->localhost_only = TRUE; ret->pending_error = 0; ret->parent = ret->child = NULL; ret->oobpending = FALSE; ret->outgoingeof = EOF_NO; ret->incomingeof = FALSE; ret->listener = 1; ret->addr = listenaddr; ret->s = -1; assert(listenaddr->superfamily == UNIX); /* * Open socket. */ s = socket(AF_UNIX, SOCK_STREAM, 0); if (s < 0) { ret->error = strerror(errno); return &ret->sock; } cloexec(s); ret->oobinline = 0; memset(&u, '\0', sizeof(u)); u.su.sun_family = AF_UNIX; #if __GNUC__ >= 8 # pragma GCC diagnostic push # pragma GCC diagnostic ignored "-Wstringop-truncation" #endif // __GNUC__ >= 8 strncpy(u.su.sun_path, listenaddr->hostname, sizeof(u.su.sun_path)-1); #if __GNUC__ >= 8 # pragma GCC diagnostic pop #endif // __GNUC__ >= 8 addr = &u; addrlen = sizeof(u.su); if (unlink(u.su.sun_path) < 0 && errno != ENOENT) { close(s); ret->error = strerror(errno); return &ret->sock; } retcode = bind(s, &addr->sa, addrlen); if (retcode < 0) { close(s); ret->error = strerror(errno); return &ret->sock; } if (listen(s, SOMAXCONN) < 0) { close(s); ret->error = strerror(errno); return &ret->sock; } ret->s = s; uxsel_tell(ret); add234(sktree, ret); return &ret->sock; }