c5e438ec |
1 | /* |
2 | * Unix networking abstraction. |
3 | */ |
4 | |
5 | #include <stdio.h> |
6 | #include <stdlib.h> |
7 | #include <assert.h> |
8 | #include <errno.h> |
9 | #include <fcntl.h> |
10 | #include <unistd.h> |
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> |
17 | #include <netdb.h> |
18 | |
19 | #define DEFINE_PLUG_METHOD_MACROS |
20 | #include "putty.h" |
21 | #include "network.h" |
22 | #include "tree234.h" |
23 | |
6ee9b735 |
24 | #define ipv4_is_loopback(addr) (inet_netof(addr) == IN_LOOPBACKNET) |
25 | |
c5e438ec |
26 | struct Socket_tag { |
27 | struct socket_function_table *fn; |
28 | /* the above variable absolutely *must* be the first in this structure */ |
29 | char *error; |
30 | int s; |
31 | Plug plug; |
32 | void *private_ptr; |
33 | bufchain output_data; |
34 | int connected; |
35 | int writable; |
36 | int frozen; /* this causes readability notifications to be ignored */ |
37 | int frozen_readable; /* this means we missed at least one readability |
38 | * notification while we were frozen */ |
39 | int localhost_only; /* for listening sockets */ |
40 | char oobdata[1]; |
41 | int sending_oob; |
42 | int oobpending; /* is there OOB data available to read? */ |
43 | int oobinline; |
44 | int pending_error; /* in case send() returns error */ |
45 | int listener; |
46 | }; |
47 | |
48 | /* |
49 | * We used to typedef struct Socket_tag *Socket. |
50 | * |
51 | * Since we have made the networking abstraction slightly more |
52 | * abstract, Socket no longer means a tcp socket (it could mean |
53 | * an ssl socket). So now we must use Actual_Socket when we know |
54 | * we are talking about a tcp socket. |
55 | */ |
56 | typedef struct Socket_tag *Actual_Socket; |
57 | |
58 | struct SockAddr_tag { |
59 | char *error; |
b7a189f3 |
60 | /* |
61 | * Which address family this address belongs to. AF_INET for |
62 | * IPv4; AF_INET6 for IPv6; AF_UNSPEC indicates that name |
63 | * resolution has not been done and a simple host name is held |
64 | * in this SockAddr structure. |
65 | */ |
c5e438ec |
66 | int family; |
67 | unsigned long address; /* Address IPv4 style. */ |
68 | #ifdef IPV6 |
69 | struct addrinfo *ai; /* Address IPv6 style. */ |
70 | #endif |
b7a189f3 |
71 | char hostname[512]; /* Store an unresolved host name. */ |
c5e438ec |
72 | }; |
73 | |
74 | static tree234 *sktree; |
75 | |
76 | static int cmpfortree(void *av, void *bv) |
77 | { |
78 | Actual_Socket a = (Actual_Socket) av, b = (Actual_Socket) bv; |
79 | int as = a->s, bs = b->s; |
80 | if (as < bs) |
81 | return -1; |
82 | if (as > bs) |
83 | return +1; |
84 | return 0; |
85 | } |
86 | |
87 | static int cmpforsearch(void *av, void *bv) |
88 | { |
89 | Actual_Socket b = (Actual_Socket) bv; |
90 | int as = (int) av, bs = b->s; |
91 | if (as < bs) |
92 | return -1; |
93 | if (as > bs) |
94 | return +1; |
95 | return 0; |
96 | } |
97 | |
98 | void sk_init(void) |
99 | { |
100 | sktree = newtree234(cmpfortree); |
101 | } |
102 | |
103 | void sk_cleanup(void) |
104 | { |
105 | Actual_Socket s; |
106 | int i; |
107 | |
108 | if (sktree) { |
109 | for (i = 0; (s = index234(sktree, i)) != NULL; i++) { |
110 | close(s->s); |
111 | } |
112 | } |
113 | } |
114 | |
115 | char *error_string(int error) |
116 | { |
e266735f |
117 | return strerror(error); |
c5e438ec |
118 | } |
119 | |
120 | SockAddr sk_namelookup(char *host, char **canonicalname) |
121 | { |
122 | SockAddr ret = smalloc(sizeof(struct SockAddr_tag)); |
123 | unsigned long a; |
124 | struct hostent *h = NULL; |
125 | char realhost[8192]; |
126 | |
127 | /* Clear the structure and default to IPv4. */ |
128 | memset(ret, 0, sizeof(struct SockAddr_tag)); |
129 | ret->family = 0; /* We set this one when we have resolved the host. */ |
130 | *realhost = '\0'; |
131 | ret->error = NULL; |
132 | |
133 | if ((a = inet_addr(host)) == (unsigned long) INADDR_NONE) { |
134 | #ifdef IPV6 |
135 | if (getaddrinfo(host, NULL, NULL, &ret->ai) == 0) { |
136 | ret->family = ret->ai->ai_family; |
137 | } else |
138 | #endif |
139 | { |
140 | /* |
141 | * Otherwise use the IPv4-only gethostbyname... (NOTE: |
142 | * we don't use gethostbyname as a fallback!) |
143 | */ |
144 | if (ret->family == 0) { |
145 | /*debug(("Resolving \"%s\" with gethostbyname() (IPv4 only)...\n", host)); */ |
146 | if ( (h = gethostbyname(host)) ) |
147 | ret->family = AF_INET; |
148 | } |
8c43874c |
149 | if (ret->family == 0) { |
c5e438ec |
150 | ret->error = (h_errno == HOST_NOT_FOUND || |
151 | h_errno == NO_DATA || |
152 | h_errno == NO_ADDRESS ? "Host does not exist" : |
153 | h_errno == TRY_AGAIN ? |
154 | "Temporary name service failure" : |
155 | "gethostbyname: unknown error"); |
8c43874c |
156 | return ret; |
157 | } |
c5e438ec |
158 | } |
159 | |
160 | #ifdef IPV6 |
161 | /* If we got an address info use that... */ |
162 | if (ret->ai) { |
163 | |
164 | /* Are we in IPv4 fallback mode? */ |
165 | /* We put the IPv4 address into the a variable so we can further-on use the IPv4 code... */ |
166 | if (ret->family == AF_INET) |
167 | memcpy(&a, |
168 | (char *) &((struct sockaddr_in *) ret->ai-> |
169 | ai_addr)->sin_addr, sizeof(a)); |
170 | |
171 | /* Now let's find that canonicalname... */ |
172 | if (getnameinfo((struct sockaddr *) ret->ai->ai_addr, |
173 | ret->family == |
174 | AF_INET ? sizeof(struct sockaddr_in) : |
175 | sizeof(struct sockaddr_in6), realhost, |
176 | sizeof(realhost), NULL, 0, 0) != 0) { |
177 | strncpy(realhost, host, sizeof(realhost)); |
178 | } |
179 | } |
180 | /* We used the IPv4-only gethostbyname()... */ |
181 | else |
182 | #endif |
183 | { |
184 | memcpy(&a, h->h_addr, sizeof(a)); |
185 | /* This way we are always sure the h->h_name is valid :) */ |
186 | strncpy(realhost, h->h_name, sizeof(realhost)); |
187 | } |
188 | } else { |
189 | /* |
190 | * This must be a numeric IPv4 address because it caused a |
191 | * success return from inet_addr. |
192 | */ |
193 | ret->family = AF_INET; |
194 | strncpy(realhost, host, sizeof(realhost)); |
195 | } |
196 | ret->address = ntohl(a); |
197 | realhost[lenof(realhost)-1] = '\0'; |
198 | *canonicalname = smalloc(1+strlen(realhost)); |
199 | strcpy(*canonicalname, realhost); |
200 | return ret; |
201 | } |
202 | |
b7a189f3 |
203 | SockAddr sk_nonamelookup(char *host) |
204 | { |
205 | SockAddr ret = smalloc(sizeof(struct SockAddr_tag)); |
206 | ret->family = AF_UNSPEC; |
207 | strncpy(ret->hostname, host, lenof(ret->hostname)); |
208 | ret->hostname[lenof(ret->hostname)-1] = '\0'; |
209 | return ret; |
210 | } |
211 | |
c5e438ec |
212 | void sk_getaddr(SockAddr addr, char *buf, int buflen) |
213 | { |
214 | #ifdef IPV6 |
b7a189f3 |
215 | if (addr->family == AF_INET6) { |
216 | FIXME; /* I don't know how to get a text form of an IPv6 address. */ |
217 | } else |
c5e438ec |
218 | #endif |
b7a189f3 |
219 | if (addr->family == AF_INET) { |
c5e438ec |
220 | struct in_addr a; |
221 | a.s_addr = htonl(addr->address); |
222 | strncpy(buf, inet_ntoa(a), buflen); |
b7a189f3 |
223 | buf[buflen-1] = '\0'; |
c5e438ec |
224 | } else { |
b7a189f3 |
225 | assert(addr->family == AF_UNSPEC); |
226 | strncpy(buf, addr->hostname, buflen); |
227 | buf[buflen-1] = '\0'; |
c5e438ec |
228 | } |
c5e438ec |
229 | } |
230 | |
b804e1e5 |
231 | int sk_hostname_is_local(char *name) |
232 | { |
233 | return !strcmp(name, "localhost"); |
234 | } |
235 | |
236 | int sk_address_is_local(SockAddr addr) |
237 | { |
238 | #ifdef IPV6 |
b7a189f3 |
239 | if (addr->family == AF_INET6) { |
240 | FIXME; /* someone who can compile for IPV6 had better do this bit */ |
241 | } else |
b804e1e5 |
242 | #endif |
b7a189f3 |
243 | if (addr->family == AF_INET) { |
b804e1e5 |
244 | struct in_addr a; |
245 | a.s_addr = htonl(addr->address); |
246 | return ipv4_is_loopback(a); |
b804e1e5 |
247 | } else { |
b7a189f3 |
248 | assert(addr->family == AF_UNSPEC); |
249 | return 0; /* we don't know; assume not */ |
b804e1e5 |
250 | } |
b804e1e5 |
251 | } |
252 | |
c5e438ec |
253 | int sk_addrtype(SockAddr addr) |
254 | { |
b7a189f3 |
255 | return (addr->family == AF_INET ? ADDRTYPE_IPV4 : |
256 | #ifdef IPV6 |
257 | addr->family == AF_INET6 ? ADDRTYPE_IPV6 : |
258 | #endif |
259 | ADDRTYPE_NAME); |
c5e438ec |
260 | } |
261 | |
262 | void sk_addrcopy(SockAddr addr, char *buf) |
263 | { |
b7a189f3 |
264 | assert(addr->family != AF_UNSPEC); |
c5e438ec |
265 | #ifdef IPV6 |
b7a189f3 |
266 | if (addr->family == AF_INET6) { |
267 | memcpy(buf, (char*) addr->ai, 16); |
268 | } else |
c5e438ec |
269 | #endif |
b7a189f3 |
270 | if (addr->family == AF_INET) { |
c5e438ec |
271 | struct in_addr a; |
272 | a.s_addr = htonl(addr->address); |
273 | memcpy(buf, (char*) &a.s_addr, 4); |
c5e438ec |
274 | } |
c5e438ec |
275 | } |
276 | |
277 | void sk_addr_free(SockAddr addr) |
278 | { |
279 | sfree(addr); |
280 | } |
281 | |
282 | static Plug sk_tcp_plug(Socket sock, Plug p) |
283 | { |
284 | Actual_Socket s = (Actual_Socket) sock; |
285 | Plug ret = s->plug; |
286 | if (p) |
287 | s->plug = p; |
288 | return ret; |
289 | } |
290 | |
291 | static void sk_tcp_flush(Socket s) |
292 | { |
293 | /* |
294 | * We send data to the socket as soon as we can anyway, |
295 | * so we don't need to do anything here. :-) |
296 | */ |
297 | } |
298 | |
299 | static void sk_tcp_close(Socket s); |
300 | static int sk_tcp_write(Socket s, char *data, int len); |
301 | static int sk_tcp_write_oob(Socket s, char *data, int len); |
302 | static void sk_tcp_set_private_ptr(Socket s, void *ptr); |
303 | static void *sk_tcp_get_private_ptr(Socket s); |
304 | static void sk_tcp_set_frozen(Socket s, int is_frozen); |
305 | static char *sk_tcp_socket_error(Socket s); |
306 | |
307 | Socket sk_register(void *sock, Plug plug) |
308 | { |
309 | static struct socket_function_table fn_table = { |
310 | sk_tcp_plug, |
311 | sk_tcp_close, |
312 | sk_tcp_write, |
313 | sk_tcp_write_oob, |
314 | sk_tcp_flush, |
315 | sk_tcp_set_private_ptr, |
316 | sk_tcp_get_private_ptr, |
317 | sk_tcp_set_frozen, |
318 | sk_tcp_socket_error |
319 | }; |
320 | |
321 | Actual_Socket ret; |
322 | |
323 | /* |
324 | * Create Socket structure. |
325 | */ |
326 | ret = smalloc(sizeof(struct Socket_tag)); |
327 | ret->fn = &fn_table; |
328 | ret->error = NULL; |
329 | ret->plug = plug; |
330 | bufchain_init(&ret->output_data); |
331 | ret->writable = 1; /* to start with */ |
332 | ret->sending_oob = 0; |
333 | ret->frozen = 1; |
334 | ret->frozen_readable = 0; |
335 | ret->localhost_only = 0; /* unused, but best init anyway */ |
336 | ret->pending_error = 0; |
337 | ret->oobpending = FALSE; |
338 | ret->listener = 0; |
339 | |
340 | ret->s = (int)sock; |
341 | |
342 | if (ret->s < 0) { |
343 | ret->error = error_string(errno); |
344 | return (Socket) ret; |
345 | } |
346 | |
347 | ret->oobinline = 0; |
348 | |
349 | add234(sktree, ret); |
350 | |
351 | return (Socket) ret; |
352 | } |
353 | |
354 | Socket sk_new(SockAddr addr, int port, int privport, int oobinline, |
355 | int nodelay, Plug plug) |
356 | { |
357 | static struct socket_function_table fn_table = { |
358 | sk_tcp_plug, |
359 | sk_tcp_close, |
360 | sk_tcp_write, |
361 | sk_tcp_write_oob, |
362 | sk_tcp_flush, |
363 | sk_tcp_set_private_ptr, |
364 | sk_tcp_get_private_ptr, |
365 | sk_tcp_set_frozen, |
366 | sk_tcp_socket_error |
367 | }; |
368 | |
369 | int s; |
370 | #ifdef IPV6 |
371 | struct sockaddr_in6 a6; |
372 | #endif |
373 | struct sockaddr_in a; |
374 | int err; |
375 | Actual_Socket ret; |
376 | short localport; |
377 | |
378 | /* |
379 | * Create Socket structure. |
380 | */ |
381 | ret = smalloc(sizeof(struct Socket_tag)); |
382 | ret->fn = &fn_table; |
383 | ret->error = NULL; |
384 | ret->plug = plug; |
385 | bufchain_init(&ret->output_data); |
386 | ret->connected = 0; /* to start with */ |
387 | ret->writable = 0; /* to start with */ |
388 | ret->sending_oob = 0; |
389 | ret->frozen = 0; |
390 | ret->frozen_readable = 0; |
391 | ret->localhost_only = 0; /* unused, but best init anyway */ |
392 | ret->pending_error = 0; |
393 | ret->oobpending = FALSE; |
394 | ret->listener = 0; |
395 | |
396 | /* |
397 | * Open socket. |
398 | */ |
b7a189f3 |
399 | assert(addr->family != AF_UNSPEC); |
c5e438ec |
400 | s = socket(addr->family, SOCK_STREAM, 0); |
401 | ret->s = s; |
402 | |
403 | if (s < 0) { |
404 | ret->error = error_string(errno); |
405 | return (Socket) ret; |
406 | } |
407 | |
408 | ret->oobinline = oobinline; |
409 | if (oobinline) { |
410 | int b = TRUE; |
411 | setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (void *) &b, sizeof(b)); |
412 | } |
413 | |
414 | if (nodelay) { |
415 | int b = TRUE; |
416 | setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (void *) &b, sizeof(b)); |
417 | } |
418 | |
419 | /* |
420 | * Bind to local address. |
421 | */ |
422 | if (privport) |
423 | localport = 1023; /* count from 1023 downwards */ |
424 | else |
425 | localport = 0; /* just use port 0 (ie kernel picks) */ |
426 | |
427 | /* Loop round trying to bind */ |
428 | while (1) { |
429 | int retcode; |
430 | |
431 | #ifdef IPV6 |
432 | if (addr->family == AF_INET6) { |
433 | memset(&a6, 0, sizeof(a6)); |
434 | a6.sin6_family = AF_INET6; |
435 | /*a6.sin6_addr = in6addr_any; *//* == 0 */ |
436 | a6.sin6_port = htons(localport); |
437 | } else |
438 | #endif |
439 | { |
440 | a.sin_family = AF_INET; |
441 | a.sin_addr.s_addr = htonl(INADDR_ANY); |
442 | a.sin_port = htons(localport); |
443 | } |
444 | #ifdef IPV6 |
445 | retcode = bind(s, (addr->family == AF_INET6 ? |
446 | (struct sockaddr *) &a6 : |
447 | (struct sockaddr *) &a), |
448 | (addr->family == |
449 | AF_INET6 ? sizeof(a6) : sizeof(a))); |
450 | #else |
451 | retcode = bind(s, (struct sockaddr *) &a, sizeof(a)); |
452 | #endif |
453 | if (retcode >= 0) { |
454 | err = 0; |
455 | break; /* done */ |
456 | } else { |
457 | err = errno; |
458 | if (err != EADDRINUSE) /* failed, for a bad reason */ |
459 | break; |
460 | } |
461 | |
462 | if (localport == 0) |
463 | break; /* we're only looping once */ |
464 | localport--; |
465 | if (localport == 0) |
466 | break; /* we might have got to the end */ |
467 | } |
468 | |
469 | if (err) { |
470 | ret->error = error_string(err); |
471 | return (Socket) ret; |
472 | } |
473 | |
474 | /* |
475 | * Connect to remote address. |
476 | */ |
477 | #ifdef IPV6 |
478 | if (addr->family == AF_INET6) { |
479 | memset(&a, 0, sizeof(a)); |
480 | a6.sin6_family = AF_INET6; |
481 | a6.sin6_port = htons((short) port); |
482 | a6.sin6_addr = |
483 | ((struct sockaddr_in6 *) addr->ai->ai_addr)->sin6_addr; |
484 | } else |
485 | #endif |
486 | { |
487 | a.sin_family = AF_INET; |
488 | a.sin_addr.s_addr = htonl(addr->address); |
489 | a.sin_port = htons((short) port); |
490 | } |
491 | |
492 | if (( |
493 | #ifdef IPV6 |
494 | connect(s, ((addr->family == AF_INET6) ? |
495 | (struct sockaddr *) &a6 : (struct sockaddr *) &a), |
496 | (addr->family == AF_INET6) ? sizeof(a6) : sizeof(a)) |
497 | #else |
498 | connect(s, (struct sockaddr *) &a, sizeof(a)) |
499 | #endif |
500 | ) < 0) { |
501 | /* |
502 | * FIXME: We are prepared to receive EWOULDBLOCK here, |
503 | * because we might want the connection to be made |
504 | * asynchronously; but how do we actually arrange this in |
505 | * Unix? I forget. |
506 | */ |
507 | if ( errno != EWOULDBLOCK ) { |
508 | ret->error = error_string(errno); |
509 | return (Socket) ret; |
510 | } |
511 | } else { |
512 | /* |
513 | * If we _don't_ get EWOULDBLOCK, the connect has completed |
514 | * and we should set the socket as connected and writable. |
515 | */ |
516 | ret->connected = 1; |
517 | ret->writable = 1; |
518 | } |
519 | |
520 | add234(sktree, ret); |
521 | |
522 | return (Socket) ret; |
523 | } |
524 | |
6ee9b735 |
525 | Socket sk_newlistener(char *srcaddr, int port, Plug plug, int local_host_only) |
c5e438ec |
526 | { |
527 | static struct socket_function_table fn_table = { |
528 | sk_tcp_plug, |
529 | sk_tcp_close, |
530 | sk_tcp_write, |
531 | sk_tcp_write_oob, |
532 | sk_tcp_flush, |
533 | sk_tcp_set_private_ptr, |
534 | sk_tcp_get_private_ptr, |
535 | sk_tcp_set_frozen, |
536 | sk_tcp_socket_error |
537 | }; |
538 | |
539 | int s; |
540 | #ifdef IPV6 |
541 | struct sockaddr_in6 a6; |
542 | #endif |
543 | struct sockaddr_in a; |
544 | int err; |
545 | Actual_Socket ret; |
546 | int retcode; |
547 | int on = 1; |
548 | |
549 | /* |
550 | * Create Socket structure. |
551 | */ |
552 | ret = smalloc(sizeof(struct Socket_tag)); |
553 | ret->fn = &fn_table; |
554 | ret->error = NULL; |
555 | ret->plug = plug; |
556 | bufchain_init(&ret->output_data); |
557 | ret->writable = 0; /* to start with */ |
558 | ret->sending_oob = 0; |
559 | ret->frozen = 0; |
560 | ret->frozen_readable = 0; |
561 | ret->localhost_only = local_host_only; |
562 | ret->pending_error = 0; |
563 | ret->oobpending = FALSE; |
564 | ret->listener = 1; |
565 | |
566 | /* |
567 | * Open socket. |
568 | */ |
569 | s = socket(AF_INET, SOCK_STREAM, 0); |
570 | ret->s = s; |
571 | |
572 | if (s < 0) { |
573 | ret->error = error_string(errno); |
574 | return (Socket) ret; |
575 | } |
576 | |
577 | ret->oobinline = 0; |
578 | |
579 | setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on)); |
580 | |
581 | #ifdef IPV6 |
582 | if (addr->family == AF_INET6) { |
583 | memset(&a6, 0, sizeof(a6)); |
584 | a6.sin6_family = AF_INET6; |
6ee9b735 |
585 | /* FIXME: srcaddr is ignored for IPv6, because I (SGT) don't |
586 | * know how to do it. :-) */ |
c5e438ec |
587 | if (local_host_only) |
588 | a6.sin6_addr = in6addr_loopback; |
589 | else |
590 | a6.sin6_addr = in6addr_any; |
591 | a6.sin6_port = htons(port); |
592 | } else |
593 | #endif |
594 | { |
6ee9b735 |
595 | int got_addr = 0; |
c5e438ec |
596 | a.sin_family = AF_INET; |
6ee9b735 |
597 | |
598 | /* |
599 | * Bind to source address. First try an explicitly |
600 | * specified one... |
601 | */ |
602 | if (srcaddr) { |
603 | a.sin_addr.s_addr = inet_addr(srcaddr); |
604 | if (a.sin_addr.s_addr != INADDR_NONE) { |
605 | /* Override localhost_only with specified listen addr. */ |
606 | ret->localhost_only = ipv4_is_loopback(a.sin_addr); |
607 | got_addr = 1; |
608 | } |
609 | } |
610 | |
611 | /* |
612 | * ... and failing that, go with one of the standard ones. |
613 | */ |
614 | if (!got_addr) { |
615 | if (local_host_only) |
616 | a.sin_addr.s_addr = htonl(INADDR_LOOPBACK); |
617 | else |
618 | a.sin_addr.s_addr = htonl(INADDR_ANY); |
619 | } |
620 | |
c5e438ec |
621 | a.sin_port = htons((short)port); |
622 | } |
623 | #ifdef IPV6 |
624 | retcode = bind(s, (addr->family == AF_INET6 ? |
625 | (struct sockaddr *) &a6 : |
626 | (struct sockaddr *) &a), |
627 | (addr->family == |
628 | AF_INET6 ? sizeof(a6) : sizeof(a))); |
629 | #else |
630 | retcode = bind(s, (struct sockaddr *) &a, sizeof(a)); |
631 | #endif |
632 | if (retcode >= 0) { |
633 | err = 0; |
634 | } else { |
635 | err = errno; |
636 | } |
637 | |
638 | if (err) { |
639 | ret->error = error_string(err); |
640 | return (Socket) ret; |
641 | } |
642 | |
643 | |
644 | if (listen(s, SOMAXCONN) < 0) { |
645 | close(s); |
646 | ret->error = error_string(errno); |
647 | return (Socket) ret; |
648 | } |
649 | |
650 | add234(sktree, ret); |
651 | |
652 | return (Socket) ret; |
653 | } |
654 | |
655 | static void sk_tcp_close(Socket sock) |
656 | { |
657 | Actual_Socket s = (Actual_Socket) sock; |
658 | |
659 | del234(sktree, s); |
660 | close(s->s); |
661 | sfree(s); |
662 | } |
663 | |
664 | /* |
665 | * The function which tries to send on a socket once it's deemed |
666 | * writable. |
667 | */ |
668 | void try_send(Actual_Socket s) |
669 | { |
670 | while (s->sending_oob || bufchain_size(&s->output_data) > 0) { |
671 | int nsent; |
672 | int err; |
673 | void *data; |
674 | int len, urgentflag; |
675 | |
676 | if (s->sending_oob) { |
677 | urgentflag = MSG_OOB; |
678 | len = s->sending_oob; |
679 | data = &s->oobdata; |
680 | } else { |
681 | urgentflag = 0; |
682 | bufchain_prefix(&s->output_data, &data, &len); |
683 | } |
684 | nsent = send(s->s, data, len, urgentflag); |
685 | noise_ultralight(nsent); |
686 | if (nsent <= 0) { |
687 | err = (nsent < 0 ? errno : 0); |
688 | if (err == EWOULDBLOCK) { |
689 | /* |
690 | * Perfectly normal: we've sent all we can for the moment. |
691 | */ |
692 | s->writable = FALSE; |
693 | return; |
694 | } else if (nsent == 0 || |
695 | err == ECONNABORTED || err == ECONNRESET) { |
696 | /* |
697 | * If send() returns CONNABORTED or CONNRESET, we |
698 | * unfortunately can't just call plug_closing(), |
699 | * because it's quite likely that we're currently |
700 | * _in_ a call from the code we'd be calling back |
701 | * to, so we'd have to make half the SSH code |
702 | * reentrant. Instead we flag a pending error on |
703 | * the socket, to be dealt with (by calling |
704 | * plug_closing()) at some suitable future moment. |
705 | */ |
706 | s->pending_error = err; |
707 | return; |
708 | } else { |
709 | /* We're inside the Unix frontend here, so we know |
710 | * that the frontend handle is unnecessary. */ |
711 | logevent(NULL, error_string(err)); |
712 | fatalbox("%s", error_string(err)); |
713 | } |
714 | } else { |
715 | if (s->sending_oob) { |
716 | if (nsent < len) { |
717 | memmove(s->oobdata, s->oobdata+nsent, len-nsent); |
718 | s->sending_oob = len - nsent; |
719 | } else { |
720 | s->sending_oob = 0; |
721 | } |
722 | } else { |
723 | bufchain_consume(&s->output_data, nsent); |
724 | } |
725 | } |
726 | } |
727 | } |
728 | |
729 | static int sk_tcp_write(Socket sock, char *buf, int len) |
730 | { |
731 | Actual_Socket s = (Actual_Socket) sock; |
732 | |
733 | /* |
734 | * Add the data to the buffer list on the socket. |
735 | */ |
736 | bufchain_add(&s->output_data, buf, len); |
737 | |
738 | /* |
739 | * Now try sending from the start of the buffer list. |
740 | */ |
741 | if (s->writable) |
742 | try_send(s); |
743 | |
744 | return bufchain_size(&s->output_data); |
745 | } |
746 | |
747 | static int sk_tcp_write_oob(Socket sock, char *buf, int len) |
748 | { |
749 | Actual_Socket s = (Actual_Socket) sock; |
750 | |
751 | /* |
752 | * Replace the buffer list on the socket with the data. |
753 | */ |
754 | bufchain_clear(&s->output_data); |
755 | assert(len <= sizeof(s->oobdata)); |
756 | memcpy(s->oobdata, buf, len); |
757 | s->sending_oob = len; |
758 | |
759 | /* |
760 | * Now try sending from the start of the buffer list. |
761 | */ |
762 | if (s->writable) |
763 | try_send(s); |
764 | |
765 | return s->sending_oob; |
766 | } |
767 | |
768 | int select_result(int fd, int event) |
769 | { |
770 | int ret; |
771 | int err; |
772 | char buf[20480]; /* nice big buffer for plenty of speed */ |
773 | Actual_Socket s; |
774 | u_long atmark; |
775 | |
776 | /* Find the Socket structure */ |
777 | s = find234(sktree, (void *) fd, cmpforsearch); |
778 | if (!s) |
779 | return 1; /* boggle */ |
780 | |
781 | noise_ultralight(event); |
782 | |
783 | switch (event) { |
784 | #ifdef FIXME_NONBLOCKING_CONNECTIONS |
785 | case FIXME: /* connected */ |
786 | s->connected = s->writable = 1; |
787 | break; |
788 | #endif |
789 | case 4: /* exceptional */ |
790 | if (!s->oobinline) { |
791 | /* |
792 | * On a non-oobinline socket, this indicates that we |
793 | * can immediately perform an OOB read and get back OOB |
794 | * data, which we will send to the back end with |
795 | * type==2 (urgent data). |
796 | */ |
797 | ret = recv(s->s, buf, sizeof(buf), MSG_OOB); |
798 | noise_ultralight(ret); |
799 | if (ret <= 0) { |
800 | char *str = (ret == 0 ? "Internal networking trouble" : |
801 | error_string(errno)); |
802 | /* We're inside the Unix frontend here, so we know |
803 | * that the frontend handle is unnecessary. */ |
804 | logevent(NULL, str); |
805 | fatalbox("%s", str); |
806 | } else { |
807 | return plug_receive(s->plug, 2, buf, ret); |
808 | } |
809 | break; |
810 | } |
811 | |
812 | /* |
813 | * If we reach here, this is an oobinline socket, which |
56e5b2db |
814 | * means we should set s->oobpending and then deal with it |
815 | * when we get called for the readability event (which |
816 | * should also occur). |
c5e438ec |
817 | */ |
818 | s->oobpending = TRUE; |
56e5b2db |
819 | break; |
c5e438ec |
820 | case 1: /* readable; also acceptance */ |
821 | if (s->listener) { |
822 | /* |
823 | * On a listening socket, the readability event means a |
824 | * connection is ready to be accepted. |
825 | */ |
826 | struct sockaddr_in isa; |
827 | int addrlen = sizeof(struct sockaddr_in); |
828 | int t; /* socket of connection */ |
829 | |
830 | memset(&isa, 0, sizeof(struct sockaddr_in)); |
831 | err = 0; |
832 | t = accept(s->s,(struct sockaddr *)&isa,&addrlen); |
833 | if (t < 0) { |
834 | break; |
835 | } |
836 | |
6ee9b735 |
837 | if (s->localhost_only && !ipv4_is_loopback(isa.sin_addr)) { |
c5e438ec |
838 | close(t); /* someone let nonlocal through?! */ |
839 | } else if (plug_accepting(s->plug, (void*)t)) { |
840 | close(t); /* denied or error */ |
841 | } |
842 | break; |
843 | } |
844 | |
845 | /* |
846 | * If we reach here, this is not a listening socket, so |
847 | * readability really means readability. |
848 | */ |
849 | |
850 | /* In the case the socket is still frozen, we don't even bother */ |
851 | if (s->frozen) { |
852 | s->frozen_readable = 1; |
853 | break; |
854 | } |
855 | |
856 | /* |
857 | * We have received data on the socket. For an oobinline |
858 | * socket, this might be data _before_ an urgent pointer, |
859 | * in which case we send it to the back end with type==1 |
860 | * (data prior to urgent). |
861 | */ |
862 | if (s->oobinline && s->oobpending) { |
863 | atmark = 1; |
864 | if (ioctl(s->s, SIOCATMARK, &atmark) == 0 && atmark) |
865 | s->oobpending = FALSE; /* clear this indicator */ |
866 | } else |
867 | atmark = 1; |
868 | |
56e5b2db |
869 | ret = recv(s->s, buf, s->oobpending ? 1 : sizeof(buf), 0); |
c5e438ec |
870 | noise_ultralight(ret); |
871 | if (ret < 0) { |
872 | if (errno == EWOULDBLOCK) { |
873 | break; |
874 | } |
875 | } |
876 | if (ret < 0) { |
877 | return plug_closing(s->plug, error_string(errno), errno, 0); |
878 | } else if (0 == ret) { |
879 | return plug_closing(s->plug, NULL, 0, 0); |
880 | } else { |
881 | return plug_receive(s->plug, atmark ? 0 : 1, buf, ret); |
882 | } |
883 | break; |
884 | case 2: /* writable */ |
885 | { |
886 | int bufsize_before, bufsize_after; |
887 | s->writable = 1; |
888 | bufsize_before = s->sending_oob + bufchain_size(&s->output_data); |
889 | try_send(s); |
890 | bufsize_after = s->sending_oob + bufchain_size(&s->output_data); |
891 | if (bufsize_after < bufsize_before) |
892 | plug_sent(s->plug, bufsize_after); |
893 | } |
894 | break; |
895 | } |
896 | |
897 | return 1; |
898 | } |
899 | |
900 | /* |
901 | * Deal with socket errors detected in try_send(). |
902 | */ |
903 | void net_pending_errors(void) |
904 | { |
905 | int i; |
906 | Actual_Socket s; |
907 | |
908 | /* |
909 | * This might be a fiddly business, because it's just possible |
910 | * that handling a pending error on one socket might cause |
911 | * others to be closed. (I can't think of any reason this might |
912 | * happen in current SSH implementation, but to maintain |
913 | * generality of this network layer I'll assume the worst.) |
914 | * |
915 | * So what we'll do is search the socket list for _one_ socket |
916 | * with a pending error, and then handle it, and then search |
917 | * the list again _from the beginning_. Repeat until we make a |
918 | * pass with no socket errors present. That way we are |
919 | * protected against the socket list changing under our feet. |
920 | */ |
921 | |
922 | do { |
923 | for (i = 0; (s = index234(sktree, i)) != NULL; i++) { |
924 | if (s->pending_error) { |
925 | /* |
926 | * An error has occurred on this socket. Pass it to the |
927 | * plug. |
928 | */ |
929 | plug_closing(s->plug, error_string(s->pending_error), |
930 | s->pending_error, 0); |
931 | break; |
932 | } |
933 | } |
934 | } while (s); |
935 | } |
936 | |
937 | /* |
938 | * Each socket abstraction contains a `void *' private field in |
939 | * which the client can keep state. |
940 | */ |
941 | static void sk_tcp_set_private_ptr(Socket sock, void *ptr) |
942 | { |
943 | Actual_Socket s = (Actual_Socket) sock; |
944 | s->private_ptr = ptr; |
945 | } |
946 | |
947 | static void *sk_tcp_get_private_ptr(Socket sock) |
948 | { |
949 | Actual_Socket s = (Actual_Socket) sock; |
950 | return s->private_ptr; |
951 | } |
952 | |
953 | /* |
954 | * Special error values are returned from sk_namelookup and sk_new |
955 | * if there's a problem. These functions extract an error message, |
956 | * or return NULL if there's no problem. |
957 | */ |
958 | char *sk_addr_error(SockAddr addr) |
959 | { |
960 | return addr->error; |
961 | } |
962 | static char *sk_tcp_socket_error(Socket sock) |
963 | { |
964 | Actual_Socket s = (Actual_Socket) sock; |
965 | return s->error; |
966 | } |
967 | |
968 | static void sk_tcp_set_frozen(Socket sock, int is_frozen) |
969 | { |
970 | Actual_Socket s = (Actual_Socket) sock; |
971 | if (s->frozen == is_frozen) |
972 | return; |
973 | s->frozen = is_frozen; |
974 | if (!is_frozen && s->frozen_readable) { |
975 | char c; |
976 | recv(s->s, &c, 1, MSG_PEEK); |
977 | } |
978 | s->frozen_readable = 0; |
979 | } |
980 | |
981 | /* |
982 | * For Unix select()-based frontends: enumerate all sockets |
983 | * currently active, and state whether we currently wish to receive |
984 | * select events on them for reading, writing and exceptional |
985 | * status. |
986 | */ |
987 | static void set_rwx(Actual_Socket s, int *rwx) |
988 | { |
989 | int val = 0; |
990 | if (s->connected && !s->frozen) |
991 | val |= 1 | 4; /* read, except */ |
992 | if (bufchain_size(&s->output_data)) |
993 | val |= 2; /* write */ |
994 | if (s->listener) |
995 | val |= 1; /* read == accept */ |
996 | *rwx = val; |
997 | } |
998 | |
999 | int first_socket(int *state, int *rwx) |
1000 | { |
1001 | Actual_Socket s; |
1002 | *state = 0; |
1003 | s = index234(sktree, (*state)++); |
1004 | if (s) |
1005 | set_rwx(s, rwx); |
1006 | return s ? s->s : -1; |
1007 | } |
1008 | |
1009 | int next_socket(int *state, int *rwx) |
1010 | { |
1011 | Actual_Socket s = index234(sktree, (*state)++); |
1012 | if (s) |
1013 | set_rwx(s, rwx); |
1014 | return s ? s->s : -1; |
1015 | } |
1016 | |
1017 | int net_service_lookup(char *service) |
1018 | { |
1019 | struct servent *se; |
1020 | se = getservbyname(service, NULL); |
1021 | if (se != NULL) |
1022 | return ntohs(se->s_port); |
1023 | else |
1024 | return 0; |
1025 | } |