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