2 * Unix networking abstraction.
11 #include <sys/types.h>
12 #include <sys/socket.h>
13 #include <sys/ioctl.h>
14 #include <arpa/inet.h>
15 #include <netinet/in.h>
16 #include <netinet/tcp.h>
20 #define DEFINE_PLUG_METHOD_MACROS
25 /* Solaris needs <sys/sockio.h> for SIOCATMARK. */
27 #include <sys/sockio.h>
31 # define X11_UNIX_PATH "/tmp/.X11-unix/X"
35 * Access to sockaddr types without breaking C strict aliasing rules.
37 union sockaddr_union {
39 struct sockaddr_in storage;
41 struct sockaddr_storage storage;
42 struct sockaddr_in6 sin6;
45 struct sockaddr_in sin;
46 struct sockaddr_un su;
50 * We used to typedef struct Socket_tag *Socket.
52 * Since we have made the networking abstraction slightly more
53 * abstract, Socket no longer means a tcp socket (it could mean
54 * an ssl socket). So now we must use Actual_Socket when we know
55 * we are talking about a tcp socket.
57 typedef struct Socket_tag *Actual_Socket;
60 * Mutable state that goes with a SockAddr: stores information
61 * about where in the list of candidate IP(v*) addresses we've
64 typedef struct SockAddrStep_tag SockAddrStep;
65 struct SockAddrStep_tag {
67 struct addrinfo *ai; /* steps along addr->ais */
73 struct socket_function_table *fn;
74 /* the above variable absolutely *must* be the first in this structure */
80 int connected; /* irrelevant for listening sockets */
82 int frozen; /* this causes readability notifications to be ignored */
83 int frozen_readable; /* this means we missed at least one readability
84 * notification while we were frozen */
85 int localhost_only; /* for listening sockets */
88 int oobpending; /* is there OOB data available to read? */
90 enum { EOF_NO, EOF_PENDING, EOF_SENT } outgoingeof;
92 int pending_error; /* in case send() returns error */
94 int nodelay, keepalive; /* for connect()-type sockets */
95 int privport, port; /* and again */
99 * We sometimes need pairs of Socket structures to be linked:
100 * if we are listening on the same IPv6 and v4 port, for
101 * example. So here we define `parent' and `child' pointers to
104 Actual_Socket parent, child;
107 struct SockAddr_tag {
110 enum { UNRESOLVED, UNIX, IP } superfamily;
112 struct addrinfo *ais; /* Addresses IPv6 style. */
114 unsigned long *addresses; /* Addresses IPv4 style. */
117 char hostname[512]; /* Store an unresolved host name. */
121 * Which address family this address belongs to. AF_INET for IPv4;
122 * AF_INET6 for IPv6; AF_UNSPEC indicates that name resolution has
123 * not been done and a simple host name is held in this SockAddr
127 #define SOCKADDR_FAMILY(addr, step) \
128 ((addr)->superfamily == UNRESOLVED ? AF_UNSPEC : \
129 (addr)->superfamily == UNIX ? AF_UNIX : \
130 (step).ai ? (step).ai->ai_family : AF_INET)
132 #define SOCKADDR_FAMILY(addr, step) \
133 ((addr)->superfamily == UNRESOLVED ? AF_UNSPEC : \
134 (addr)->superfamily == UNIX ? AF_UNIX : AF_INET)
138 * Start a SockAddrStep structure to step through multiple
142 #define START_STEP(addr, step) \
143 ((step).ai = (addr)->ais, (step).curraddr = 0)
145 #define START_STEP(addr, step) \
146 ((step).curraddr = 0)
149 static tree234 *sktree;
151 static void uxsel_tell(Actual_Socket s);
153 static int cmpfortree(void *av, void *bv)
155 Actual_Socket a = (Actual_Socket) av, b = (Actual_Socket) bv;
156 int as = a->s, bs = b->s;
168 static int cmpforsearch(void *av, void *bv)
170 Actual_Socket b = (Actual_Socket) bv;
171 int as = *(int *)av, bs = b->s;
181 sktree = newtree234(cmpfortree);
184 void sk_cleanup(void)
190 for (i = 0; (s = index234(sktree, i)) != NULL; i++) {
196 SockAddr sk_namelookup(const char *host, char **canonicalname, int address_family)
198 SockAddr ret = snew(struct SockAddr_tag);
200 struct addrinfo hints;
204 struct hostent *h = NULL;
209 /* Clear the structure and default to IPv4. */
210 memset(ret, 0, sizeof(struct SockAddr_tag));
211 ret->superfamily = UNRESOLVED;
217 hints.ai_flags = AI_CANONNAME;
218 hints.ai_family = (address_family == ADDRTYPE_IPV4 ? AF_INET :
219 address_family == ADDRTYPE_IPV6 ? AF_INET6 :
221 hints.ai_socktype = SOCK_STREAM;
222 hints.ai_protocol = 0;
223 hints.ai_addrlen = 0;
224 hints.ai_addr = NULL;
225 hints.ai_canonname = NULL;
226 hints.ai_next = NULL;
227 err = getaddrinfo(host, NULL, &hints, &ret->ais);
229 ret->error = gai_strerror(err);
232 ret->superfamily = IP;
234 if (ret->ais->ai_canonname != NULL)
235 strncat(realhost, ret->ais->ai_canonname, sizeof(realhost) - 1);
237 strncat(realhost, host, sizeof(realhost) - 1);
239 if ((a = inet_addr(host)) == (unsigned long)(in_addr_t)(-1)) {
241 * Otherwise use the IPv4-only gethostbyname... (NOTE:
242 * we don't use gethostbyname as a fallback!)
244 if (ret->superfamily == UNRESOLVED) {
245 /*debug(("Resolving \"%s\" with gethostbyname() (IPv4 only)...\n", host)); */
246 if ( (h = gethostbyname(host)) )
247 ret->superfamily = IP;
249 if (ret->superfamily == UNRESOLVED) {
250 ret->error = (h_errno == HOST_NOT_FOUND ||
251 h_errno == NO_DATA ||
252 h_errno == NO_ADDRESS ? "Host does not exist" :
253 h_errno == TRY_AGAIN ?
254 "Temporary name service failure" :
255 "gethostbyname: unknown error");
258 /* This way we are always sure the h->h_name is valid :) */
259 strncpy(realhost, h->h_name, sizeof(realhost));
260 for (n = 0; h->h_addr_list[n]; n++);
261 ret->addresses = snewn(n, unsigned long);
263 for (n = 0; n < ret->naddresses; n++) {
264 memcpy(&a, h->h_addr_list[n], sizeof(a));
265 ret->addresses[n] = ntohl(a);
269 * This must be a numeric IPv4 address because it caused a
270 * success return from inet_addr.
272 ret->superfamily = IP;
273 strncpy(realhost, host, sizeof(realhost));
274 ret->addresses = snew(unsigned long);
276 ret->addresses[0] = ntohl(a);
279 realhost[lenof(realhost)-1] = '\0';
280 *canonicalname = snewn(1+strlen(realhost), char);
281 strcpy(*canonicalname, realhost);
285 SockAddr sk_nonamelookup(const char *host)
287 SockAddr ret = snew(struct SockAddr_tag);
289 ret->superfamily = UNRESOLVED;
290 strncpy(ret->hostname, host, lenof(ret->hostname));
291 ret->hostname[lenof(ret->hostname)-1] = '\0';
295 ret->addresses = NULL;
301 static int sk_nextaddr(SockAddr addr, SockAddrStep *step)
304 if (step->ai && step->ai->ai_next) {
305 step->ai = step->ai->ai_next;
310 if (step->curraddr+1 < addr->naddresses) {
319 void sk_getaddr(SockAddr addr, char *buf, int buflen)
321 /* XXX not clear what we should return for Unix-domain sockets; let's
322 * hope the question never arises */
323 assert(addr->superfamily != UNIX);
324 if (addr->superfamily == UNRESOLVED) {
325 strncpy(buf, addr->hostname, buflen);
326 buf[buflen-1] = '\0';
329 if (getnameinfo(addr->ais->ai_addr, addr->ais->ai_addrlen, buf, buflen,
330 NULL, 0, NI_NUMERICHOST) != 0) {
332 strncat(buf, "<unknown>", buflen - 1);
337 START_STEP(addr, step);
338 assert(SOCKADDR_FAMILY(addr, step) == AF_INET);
339 a.s_addr = htonl(addr->addresses[0]);
340 strncpy(buf, inet_ntoa(a), buflen);
341 buf[buflen-1] = '\0';
346 int sk_hostname_is_local(char *name)
348 return !strcmp(name, "localhost") ||
349 !strcmp(name, "::1") ||
350 !strncmp(name, "127.", 4);
353 #define ipv4_is_loopback(addr) \
354 (((addr).s_addr & htonl(0xff000000)) == htonl(0x7f000000))
356 static int sockaddr_is_loopback(struct sockaddr *sa)
358 union sockaddr_union *u = (union sockaddr_union *)sa;
359 switch (u->sa.sa_family) {
361 return ipv4_is_loopback(u->sin.sin_addr);
364 return IN6_IS_ADDR_LOOPBACK(&u->sin6.sin6_addr);
373 int sk_address_is_local(SockAddr addr)
375 if (addr->superfamily == UNRESOLVED)
376 return 0; /* we don't know; assume not */
377 else if (addr->superfamily == UNIX)
381 return sockaddr_is_loopback(addr->ais->ai_addr);
385 START_STEP(addr, step);
386 assert(SOCKADDR_FAMILY(addr, step) == AF_INET);
387 a.s_addr = htonl(addr->addresses[0]);
388 return ipv4_is_loopback(a);
393 int sk_address_is_special_local(SockAddr addr)
395 return addr->superfamily == UNIX;
398 int sk_addrtype(SockAddr addr)
402 START_STEP(addr, step);
403 family = SOCKADDR_FAMILY(addr, step);
405 return (family == AF_INET ? ADDRTYPE_IPV4 :
407 family == AF_INET6 ? ADDRTYPE_IPV6 :
412 void sk_addrcopy(SockAddr addr, char *buf)
416 START_STEP(addr, step);
417 family = SOCKADDR_FAMILY(addr, step);
420 if (family == AF_INET)
421 memcpy(buf, &((struct sockaddr_in *)step.ai->ai_addr)->sin_addr,
422 sizeof(struct in_addr));
423 else if (family == AF_INET6)
424 memcpy(buf, &((struct sockaddr_in6 *)step.ai->ai_addr)->sin6_addr,
425 sizeof(struct in6_addr));
431 assert(family == AF_INET);
432 a.s_addr = htonl(addr->addresses[step.curraddr]);
433 memcpy(buf, (char*) &a.s_addr, 4);
437 void sk_addr_free(SockAddr addr)
439 if (--addr->refcount > 0)
442 if (addr->ais != NULL)
443 freeaddrinfo(addr->ais);
445 sfree(addr->addresses);
450 SockAddr sk_addr_dup(SockAddr addr)
456 static Plug sk_tcp_plug(Socket sock, Plug p)
458 Actual_Socket s = (Actual_Socket) sock;
465 static void sk_tcp_flush(Socket s)
468 * We send data to the socket as soon as we can anyway,
469 * so we don't need to do anything here. :-)
473 static void sk_tcp_close(Socket s);
474 static int sk_tcp_write(Socket s, const char *data, int len);
475 static int sk_tcp_write_oob(Socket s, const char *data, int len);
476 static void sk_tcp_write_eof(Socket s);
477 static void sk_tcp_set_private_ptr(Socket s, void *ptr);
478 static void *sk_tcp_get_private_ptr(Socket s);
479 static void sk_tcp_set_frozen(Socket s, int is_frozen);
480 static const char *sk_tcp_socket_error(Socket s);
482 static struct socket_function_table tcp_fn_table = {
489 sk_tcp_set_private_ptr,
490 sk_tcp_get_private_ptr,
495 Socket sk_register(OSSocket sockfd, Plug plug)
500 * Create Socket structure.
502 ret = snew(struct Socket_tag);
503 ret->fn = &tcp_fn_table;
506 bufchain_init(&ret->output_data);
507 ret->writable = 1; /* to start with */
508 ret->sending_oob = 0;
510 ret->frozen_readable = 0;
511 ret->localhost_only = 0; /* unused, but best init anyway */
512 ret->pending_error = 0;
513 ret->oobpending = FALSE;
514 ret->outgoingeof = EOF_NO;
515 ret->incomingeof = FALSE;
517 ret->parent = ret->child = NULL;
524 ret->error = strerror(errno);
536 static int try_connect(Actual_Socket sock)
539 union sockaddr_union u;
540 const union sockaddr_union *sa;
543 int fl, salen, family;
546 * Remove the socket from the tree before we overwrite its
547 * internal socket id, because that forms part of the tree's
548 * sorting criterion. We'll add it back before exiting this
549 * function, whether we changed anything or not.
551 del234(sktree, sock);
556 plug_log(sock->plug, 0, sock->addr, sock->port, NULL, 0);
561 family = SOCKADDR_FAMILY(sock->addr, sock->step);
562 assert(family != AF_UNSPEC);
563 s = socket(family, SOCK_STREAM, 0);
573 if (sock->oobinline) {
575 setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (void *) &b, sizeof(b));
580 setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (void *) &b, sizeof(b));
583 if (sock->keepalive) {
585 setsockopt(s, SOL_SOCKET, SO_KEEPALIVE, (void *) &b, sizeof(b));
589 * Bind to local address.
592 localport = 1023; /* count from 1023 downwards */
594 localport = 0; /* just use port 0 (ie kernel picks) */
596 /* BSD IP stacks need sockaddr_in zeroed before filling in */
597 memset(&u,'\0',sizeof(u));
599 /* We don't try to bind to a local address for UNIX domain sockets. (Why
600 * do we bother doing the bind when localport == 0 anyway?) */
601 if (family != AF_UNIX) {
602 /* Loop round trying to bind */
607 if (family == AF_INET6) {
608 /* XXX use getaddrinfo to get a local address? */
609 u.sin6.sin6_family = AF_INET6;
610 u.sin6.sin6_addr = in6addr_any;
611 u.sin6.sin6_port = htons(localport);
612 retcode = bind(s, &u.sa, sizeof(u.sin6));
616 assert(family == AF_INET);
617 u.sin.sin_family = AF_INET;
618 u.sin.sin_addr.s_addr = htonl(INADDR_ANY);
619 u.sin.sin_port = htons(localport);
620 retcode = bind(s, &u.sa, sizeof(u.sin));
627 if (err != EADDRINUSE) /* failed, for a bad reason */
632 break; /* we're only looping once */
635 break; /* we might have got to the end */
643 * Connect to remote address.
648 /* XXX would be better to have got getaddrinfo() to fill in the port. */
649 ((struct sockaddr_in *)sock->step.ai->ai_addr)->sin_port =
651 sa = (const union sockaddr_union *)sock->step.ai->ai_addr;
652 salen = sock->step.ai->ai_addrlen;
655 ((struct sockaddr_in *)sock->step.ai->ai_addr)->sin_port =
657 sa = (const union sockaddr_union *)sock->step.ai->ai_addr;
658 salen = sock->step.ai->ai_addrlen;
662 u.sin.sin_family = AF_INET;
663 u.sin.sin_addr.s_addr = htonl(sock->addr->addresses[sock->step.curraddr]);
664 u.sin.sin_port = htons((short) sock->port);
666 salen = sizeof u.sin;
670 assert(sock->port == 0); /* to catch confused people */
671 assert(strlen(sock->addr->hostname) < sizeof u.su.sun_path);
672 u.su.sun_family = AF_UNIX;
673 strcpy(u.su.sun_path, sock->addr->hostname);
679 assert(0 && "unknown address family");
680 exit(1); /* XXX: GCC doesn't understand assert() on some systems. */
683 fl = fcntl(s, F_GETFL);
685 fcntl(s, F_SETFL, fl | O_NONBLOCK);
687 if ((connect(s, &(sa->sa), salen)) < 0) {
688 if ( errno != EINPROGRESS ) {
694 * If we _don't_ get EWOULDBLOCK, the connect has completed
695 * and we should set the socket as connected and writable.
706 * No matter what happened, put the socket back in the tree.
708 add234(sktree, sock);
711 plug_log(sock->plug, 1, sock->addr, sock->port, strerror(err), err);
715 Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
716 int nodelay, int keepalive, Plug plug)
722 * Create Socket structure.
724 ret = snew(struct Socket_tag);
725 ret->fn = &tcp_fn_table;
728 bufchain_init(&ret->output_data);
729 ret->connected = 0; /* to start with */
730 ret->writable = 0; /* to start with */
731 ret->sending_oob = 0;
733 ret->frozen_readable = 0;
734 ret->localhost_only = 0; /* unused, but best init anyway */
735 ret->pending_error = 0;
736 ret->parent = ret->child = NULL;
737 ret->oobpending = FALSE;
738 ret->outgoingeof = EOF_NO;
739 ret->incomingeof = FALSE;
742 START_STEP(ret->addr, ret->step);
744 ret->oobinline = oobinline;
745 ret->nodelay = nodelay;
746 ret->keepalive = keepalive;
747 ret->privport = privport;
752 err = try_connect(ret);
753 } while (err && sk_nextaddr(ret->addr, &ret->step));
756 ret->error = strerror(err);
761 Socket sk_newlistener(char *srcaddr, int port, Plug plug, int local_host_only, int orig_address_family)
765 struct addrinfo hints, *ai;
768 union sockaddr_union u;
769 union sockaddr_union *addr;
777 * Create Socket structure.
779 ret = snew(struct Socket_tag);
780 ret->fn = &tcp_fn_table;
783 bufchain_init(&ret->output_data);
784 ret->writable = 0; /* to start with */
785 ret->sending_oob = 0;
787 ret->frozen_readable = 0;
788 ret->localhost_only = local_host_only;
789 ret->pending_error = 0;
790 ret->parent = ret->child = NULL;
791 ret->oobpending = FALSE;
792 ret->outgoingeof = EOF_NO;
793 ret->incomingeof = FALSE;
798 * Translate address_family from platform-independent constants
799 * into local reality.
801 address_family = (orig_address_family == ADDRTYPE_IPV4 ? AF_INET :
803 orig_address_family == ADDRTYPE_IPV6 ? AF_INET6 :
808 /* Let's default to IPv6.
809 * If the stack doesn't support IPv6, we will fall back to IPv4. */
810 if (address_family == AF_UNSPEC) address_family = AF_INET6;
812 /* No other choice, default to IPv4 */
813 if (address_family == AF_UNSPEC) address_family = AF_INET;
819 s = socket(address_family, SOCK_STREAM, 0);
822 /* If the host doesn't support IPv6 try fallback to IPv4. */
823 if (s < 0 && address_family == AF_INET6) {
824 address_family = AF_INET;
825 s = socket(address_family, SOCK_STREAM, 0);
830 ret->error = strerror(errno);
838 setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on));
841 addr = NULL; addrlen = -1; /* placate optimiser */
843 if (srcaddr != NULL) {
845 hints.ai_flags = AI_NUMERICHOST;
846 hints.ai_family = address_family;
847 hints.ai_socktype = SOCK_STREAM;
848 hints.ai_protocol = 0;
849 hints.ai_addrlen = 0;
850 hints.ai_addr = NULL;
851 hints.ai_canonname = NULL;
852 hints.ai_next = NULL;
853 assert(port >= 0 && port <= 99999);
854 sprintf(portstr, "%d", port);
855 retcode = getaddrinfo(srcaddr, portstr, &hints, &ai);
857 addr = (union sockaddr_union *)ai->ai_addr;
858 addrlen = ai->ai_addrlen;
861 memset(&u,'\0',sizeof u);
862 u.sin.sin_family = AF_INET;
863 u.sin.sin_port = htons(port);
864 u.sin.sin_addr.s_addr = inet_addr(srcaddr);
865 if (u.sin.sin_addr.s_addr != (in_addr_t)(-1)) {
866 /* Override localhost_only with specified listen addr. */
867 ret->localhost_only = ipv4_is_loopback(u.sin.sin_addr);
870 addrlen = sizeof(u.sin);
876 memset(&u,'\0',sizeof u);
878 if (address_family == AF_INET6) {
879 u.sin6.sin6_family = AF_INET6;
880 u.sin6.sin6_port = htons(port);
882 u.sin6.sin6_addr = in6addr_loopback;
884 u.sin6.sin6_addr = in6addr_any;
886 addrlen = sizeof(u.sin6);
890 u.sin.sin_family = AF_INET;
891 u.sin.sin_port = htons(port);
893 u.sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
895 u.sin.sin_addr.s_addr = htonl(INADDR_ANY);
897 addrlen = sizeof(u.sin);
901 retcode = bind(s, &addr->sa, addrlen);
904 ret->error = strerror(errno);
908 if (listen(s, SOMAXCONN) < 0) {
910 ret->error = strerror(errno);
916 * If we were given ADDRTYPE_UNSPEC, we must also create an
917 * IPv4 listening socket and link it to this one.
919 if (address_family == AF_INET6 && orig_address_family == ADDRTYPE_UNSPEC) {
922 other = (Actual_Socket) sk_newlistener(srcaddr, port, plug,
923 local_host_only, ADDRTYPE_IPV4);
930 /* If we couldn't create a listening socket on IPv4 as well
931 * as IPv6, we must return an error overall. */
934 return (Socket) other;
948 static void sk_tcp_close(Socket sock)
950 Actual_Socket s = (Actual_Socket) sock;
953 sk_tcp_close((Socket)s->child);
959 sk_addr_free(s->addr);
963 void *sk_getxdmdata(void *sock, int *lenp)
965 Actual_Socket s = (Actual_Socket) sock;
966 union sockaddr_union u;
969 static unsigned int unix_addr = 0xFFFFFFFF;
972 * We must check that this socket really _is_ an Actual_Socket.
974 if (s->fn != &tcp_fn_table)
975 return NULL; /* failure */
978 if (getsockname(s->s, &u.sa, &addrlen) < 0)
980 switch(u.sa.sa_family) {
983 buf = snewn(*lenp, char);
984 PUT_32BIT_MSB_FIRST(buf, ntohl(u.sin.sin_addr.s_addr));
985 PUT_16BIT_MSB_FIRST(buf+4, ntohs(u.sin.sin_port));
990 buf = snewn(*lenp, char);
991 if (IN6_IS_ADDR_V4MAPPED(&u.sin6.sin6_addr)) {
992 memcpy(buf, u.sin6.sin6_addr.s6_addr + 12, 4);
993 PUT_16BIT_MSB_FIRST(buf+4, ntohs(u.sin6.sin6_port));
995 /* This is stupid, but it's what XLib does. */
1001 buf = snewn(*lenp, char);
1002 PUT_32BIT_MSB_FIRST(buf, unix_addr--);
1003 PUT_16BIT_MSB_FIRST(buf+4, getpid());
1016 * The function which tries to send on a socket once it's deemed
1019 void try_send(Actual_Socket s)
1021 while (s->sending_oob || bufchain_size(&s->output_data) > 0) {
1025 int len, urgentflag;
1027 if (s->sending_oob) {
1028 urgentflag = MSG_OOB;
1029 len = s->sending_oob;
1033 bufchain_prefix(&s->output_data, &data, &len);
1035 nsent = send(s->s, data, len, urgentflag);
1036 noise_ultralight(nsent);
1038 err = (nsent < 0 ? errno : 0);
1039 if (err == EWOULDBLOCK) {
1041 * Perfectly normal: we've sent all we can for the moment.
1043 s->writable = FALSE;
1047 * We unfortunately can't just call plug_closing(),
1048 * because it's quite likely that we're currently
1049 * _in_ a call from the code we'd be calling back
1050 * to, so we'd have to make half the SSH code
1051 * reentrant. Instead we flag a pending error on
1052 * the socket, to be dealt with (by calling
1053 * plug_closing()) at some suitable future moment.
1055 s->pending_error = err;
1057 * Immediately cease selecting on this socket, so that
1058 * we don't tight-loop repeatedly trying to do
1059 * whatever it was that went wrong.
1063 * Notify the front end that it might want to call us.
1065 frontend_net_error_pending();
1069 if (s->sending_oob) {
1071 memmove(s->oobdata, s->oobdata+nsent, len-nsent);
1072 s->sending_oob = len - nsent;
1077 bufchain_consume(&s->output_data, nsent);
1083 * If we reach here, we've finished sending everything we might
1084 * have needed to send. Send EOF, if we need to.
1086 if (s->outgoingeof == EOF_PENDING) {
1087 shutdown(s->s, SHUT_WR);
1088 s->outgoingeof = EOF_SENT;
1092 * Also update the select status, because we don't need to select
1093 * for writing any more.
1098 static int sk_tcp_write(Socket sock, const char *buf, int len)
1100 Actual_Socket s = (Actual_Socket) sock;
1102 assert(s->outgoingeof == EOF_NO);
1105 * Add the data to the buffer list on the socket.
1107 bufchain_add(&s->output_data, buf, len);
1110 * Now try sending from the start of the buffer list.
1116 * Update the select() status to correctly reflect whether or
1117 * not we should be selecting for write.
1121 return bufchain_size(&s->output_data);
1124 static int sk_tcp_write_oob(Socket sock, const char *buf, int len)
1126 Actual_Socket s = (Actual_Socket) sock;
1128 assert(s->outgoingeof == EOF_NO);
1131 * Replace the buffer list on the socket with the data.
1133 bufchain_clear(&s->output_data);
1134 assert(len <= sizeof(s->oobdata));
1135 memcpy(s->oobdata, buf, len);
1136 s->sending_oob = len;
1139 * Now try sending from the start of the buffer list.
1145 * Update the select() status to correctly reflect whether or
1146 * not we should be selecting for write.
1150 return s->sending_oob;
1153 static void sk_tcp_write_eof(Socket sock)
1155 Actual_Socket s = (Actual_Socket) sock;
1157 assert(s->outgoingeof == EOF_NO);
1160 * Mark the socket as pending outgoing EOF.
1162 s->outgoingeof = EOF_PENDING;
1165 * Now try sending from the start of the buffer list.
1171 * Update the select() status to correctly reflect whether or
1172 * not we should be selecting for write.
1177 static int net_select_result(int fd, int event)
1180 char buf[20480]; /* nice big buffer for plenty of speed */
1184 /* Find the Socket structure */
1185 s = find234(sktree, &fd, cmpforsearch);
1187 return 1; /* boggle */
1189 noise_ultralight(event);
1192 case 4: /* exceptional */
1193 if (!s->oobinline) {
1195 * On a non-oobinline socket, this indicates that we
1196 * can immediately perform an OOB read and get back OOB
1197 * data, which we will send to the back end with
1198 * type==2 (urgent data).
1200 ret = recv(s->s, buf, sizeof(buf), MSG_OOB);
1201 noise_ultralight(ret);
1203 return plug_closing(s->plug,
1204 ret == 0 ? "Internal networking trouble" :
1205 strerror(errno), errno, 0);
1208 * Receiving actual data on a socket means we can
1209 * stop falling back through the candidate
1210 * addresses to connect to.
1213 sk_addr_free(s->addr);
1216 return plug_receive(s->plug, 2, buf, ret);
1222 * If we reach here, this is an oobinline socket, which
1223 * means we should set s->oobpending and then deal with it
1224 * when we get called for the readability event (which
1225 * should also occur).
1227 s->oobpending = TRUE;
1229 case 1: /* readable; also acceptance */
1232 * On a listening socket, the readability event means a
1233 * connection is ready to be accepted.
1235 union sockaddr_union su;
1236 socklen_t addrlen = sizeof(su);
1237 int t; /* socket of connection */
1240 memset(&su, 0, addrlen);
1241 t = accept(s->s, &su.sa, &addrlen);
1246 fl = fcntl(t, F_GETFL);
1248 fcntl(t, F_SETFL, fl | O_NONBLOCK);
1250 if (s->localhost_only &&
1251 !sockaddr_is_loopback(&su.sa)) {
1252 close(t); /* someone let nonlocal through?! */
1253 } else if (plug_accepting(s->plug, t)) {
1254 close(t); /* denied or error */
1260 * If we reach here, this is not a listening socket, so
1261 * readability really means readability.
1264 /* In the case the socket is still frozen, we don't even bother */
1266 s->frozen_readable = 1;
1271 * We have received data on the socket. For an oobinline
1272 * socket, this might be data _before_ an urgent pointer,
1273 * in which case we send it to the back end with type==1
1274 * (data prior to urgent).
1276 if (s->oobinline && s->oobpending) {
1278 if (ioctl(s->s, SIOCATMARK, &atmark) == 0 && atmark)
1279 s->oobpending = FALSE; /* clear this indicator */
1283 ret = recv(s->s, buf, s->oobpending ? 1 : sizeof(buf), 0);
1284 noise_ultralight(ret);
1286 if (errno == EWOULDBLOCK) {
1292 * An error at this point _might_ be an error reported
1293 * by a non-blocking connect(). So before we return a
1294 * panic status to the user, let's just see whether
1299 plug_log(s->plug, 1, s->addr, s->port, strerror(err), err);
1300 while (s->addr && sk_nextaddr(s->addr, &s->step)) {
1301 err = try_connect(s);
1305 return plug_closing(s->plug, strerror(err), err, 0);
1306 } else if (0 == ret) {
1307 s->incomingeof = TRUE; /* stop trying to read now */
1309 return plug_closing(s->plug, NULL, 0, 0);
1312 * Receiving actual data on a socket means we can
1313 * stop falling back through the candidate
1314 * addresses to connect to.
1317 sk_addr_free(s->addr);
1320 return plug_receive(s->plug, atmark ? 0 : 1, buf, ret);
1323 case 2: /* writable */
1324 if (!s->connected) {
1326 * select() reports a socket as _writable_ when an
1327 * asynchronous connection is completed.
1329 s->connected = s->writable = 1;
1333 int bufsize_before, bufsize_after;
1335 bufsize_before = s->sending_oob + bufchain_size(&s->output_data);
1337 bufsize_after = s->sending_oob + bufchain_size(&s->output_data);
1338 if (bufsize_after < bufsize_before)
1339 plug_sent(s->plug, bufsize_after);
1348 * Deal with socket errors detected in try_send().
1350 void net_pending_errors(void)
1356 * This might be a fiddly business, because it's just possible
1357 * that handling a pending error on one socket might cause
1358 * others to be closed. (I can't think of any reason this might
1359 * happen in current SSH implementation, but to maintain
1360 * generality of this network layer I'll assume the worst.)
1362 * So what we'll do is search the socket list for _one_ socket
1363 * with a pending error, and then handle it, and then search
1364 * the list again _from the beginning_. Repeat until we make a
1365 * pass with no socket errors present. That way we are
1366 * protected against the socket list changing under our feet.
1370 for (i = 0; (s = index234(sktree, i)) != NULL; i++) {
1371 if (s->pending_error) {
1373 * An error has occurred on this socket. Pass it to the
1376 plug_closing(s->plug, strerror(s->pending_error),
1377 s->pending_error, 0);
1385 * Each socket abstraction contains a `void *' private field in
1386 * which the client can keep state.
1388 static void sk_tcp_set_private_ptr(Socket sock, void *ptr)
1390 Actual_Socket s = (Actual_Socket) sock;
1391 s->private_ptr = ptr;
1394 static void *sk_tcp_get_private_ptr(Socket sock)
1396 Actual_Socket s = (Actual_Socket) sock;
1397 return s->private_ptr;
1401 * Special error values are returned from sk_namelookup and sk_new
1402 * if there's a problem. These functions extract an error message,
1403 * or return NULL if there's no problem.
1405 const char *sk_addr_error(SockAddr addr)
1409 static const char *sk_tcp_socket_error(Socket sock)
1411 Actual_Socket s = (Actual_Socket) sock;
1415 static void sk_tcp_set_frozen(Socket sock, int is_frozen)
1417 Actual_Socket s = (Actual_Socket) sock;
1418 if (s->frozen == is_frozen)
1420 s->frozen = is_frozen;
1421 if (!is_frozen && s->frozen_readable) {
1423 recv(s->s, &c, 1, MSG_PEEK);
1425 s->frozen_readable = 0;
1429 static void uxsel_tell(Actual_Socket s)
1432 if (!s->pending_error) {
1434 rwx |= 1; /* read == accept */
1437 rwx |= 2; /* write == connect */
1438 if (s->connected && !s->frozen && !s->incomingeof)
1439 rwx |= 1 | 4; /* read, except */
1440 if (bufchain_size(&s->output_data))
1441 rwx |= 2; /* write */
1444 uxsel_set(s->s, rwx, net_select_result);
1447 int net_service_lookup(char *service)
1450 se = getservbyname(service, NULL);
1452 return ntohs(se->s_port);
1457 char *get_hostname(void)
1460 char *hostname = NULL;
1463 hostname = sresize(hostname, len, char);
1464 if ((gethostname(hostname, len) < 0) &&
1465 (errno != ENAMETOOLONG)) {
1470 } while (strlen(hostname) >= len-1);
1474 SockAddr platform_get_x11_unix_address(const char *sockpath, int displaynum)
1476 SockAddr ret = snew(struct SockAddr_tag);
1479 memset(ret, 0, sizeof *ret);
1480 ret->superfamily = UNIX;
1482 * In special circumstances (notably Mac OS X Leopard), we'll
1483 * have been passed an explicit Unix socket path.
1486 n = snprintf(ret->hostname, sizeof ret->hostname,
1489 n = snprintf(ret->hostname, sizeof ret->hostname,
1490 "%s%d", X11_UNIX_PATH, displaynum);
1494 ret->error = "snprintf failed";
1495 else if (n >= sizeof ret->hostname)
1496 ret->error = "X11 UNIX name too long";
1501 ret->addresses = NULL;
1502 ret->naddresses = 0;