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 | { |
ea05787d |
109 | char *ret = smalloc(strlen(strerror(error)) + |
110 | strlen("Network error: ")); |
111 | sprintf(ret, "Network error: %s",strerror(error)); |
112 | return ret; |
c5e438ec |
113 | } |
114 | |
115 | SockAddr sk_namelookup(char *host, char **canonicalname) |
116 | { |
117 | SockAddr ret = smalloc(sizeof(struct SockAddr_tag)); |
118 | unsigned long a; |
119 | struct hostent *h = NULL; |
120 | char realhost[8192]; |
121 | |
122 | /* Clear the structure and default to IPv4. */ |
123 | memset(ret, 0, sizeof(struct SockAddr_tag)); |
124 | ret->family = 0; /* We set this one when we have resolved the host. */ |
125 | *realhost = '\0'; |
126 | ret->error = NULL; |
127 | |
128 | if ((a = inet_addr(host)) == (unsigned long) INADDR_NONE) { |
129 | #ifdef IPV6 |
130 | if (getaddrinfo(host, NULL, NULL, &ret->ai) == 0) { |
131 | ret->family = ret->ai->ai_family; |
132 | } else |
133 | #endif |
134 | { |
135 | /* |
136 | * Otherwise use the IPv4-only gethostbyname... (NOTE: |
137 | * we don't use gethostbyname as a fallback!) |
138 | */ |
139 | if (ret->family == 0) { |
140 | /*debug(("Resolving \"%s\" with gethostbyname() (IPv4 only)...\n", host)); */ |
141 | if ( (h = gethostbyname(host)) ) |
142 | ret->family = AF_INET; |
143 | } |
8c43874c |
144 | if (ret->family == 0) { |
c5e438ec |
145 | ret->error = (h_errno == HOST_NOT_FOUND || |
146 | h_errno == NO_DATA || |
147 | h_errno == NO_ADDRESS ? "Host does not exist" : |
148 | h_errno == TRY_AGAIN ? |
149 | "Temporary name service failure" : |
150 | "gethostbyname: unknown error"); |
8c43874c |
151 | return ret; |
152 | } |
c5e438ec |
153 | } |
154 | |
155 | #ifdef IPV6 |
156 | /* If we got an address info use that... */ |
157 | if (ret->ai) { |
158 | |
159 | /* Are we in IPv4 fallback mode? */ |
160 | /* We put the IPv4 address into the a variable so we can further-on use the IPv4 code... */ |
161 | if (ret->family == AF_INET) |
162 | memcpy(&a, |
163 | (char *) &((struct sockaddr_in *) ret->ai-> |
164 | ai_addr)->sin_addr, sizeof(a)); |
165 | |
166 | /* Now let's find that canonicalname... */ |
167 | if (getnameinfo((struct sockaddr *) ret->ai->ai_addr, |
168 | ret->family == |
169 | AF_INET ? sizeof(struct sockaddr_in) : |
170 | sizeof(struct sockaddr_in6), realhost, |
171 | sizeof(realhost), NULL, 0, 0) != 0) { |
172 | strncpy(realhost, host, sizeof(realhost)); |
173 | } |
174 | } |
175 | /* We used the IPv4-only gethostbyname()... */ |
176 | else |
177 | #endif |
178 | { |
179 | memcpy(&a, h->h_addr, sizeof(a)); |
180 | /* This way we are always sure the h->h_name is valid :) */ |
181 | strncpy(realhost, h->h_name, sizeof(realhost)); |
182 | } |
183 | } else { |
184 | /* |
185 | * This must be a numeric IPv4 address because it caused a |
186 | * success return from inet_addr. |
187 | */ |
188 | ret->family = AF_INET; |
189 | strncpy(realhost, host, sizeof(realhost)); |
190 | } |
191 | ret->address = ntohl(a); |
192 | realhost[lenof(realhost)-1] = '\0'; |
193 | *canonicalname = smalloc(1+strlen(realhost)); |
194 | strcpy(*canonicalname, realhost); |
195 | return ret; |
196 | } |
197 | |
198 | void sk_getaddr(SockAddr addr, char *buf, int buflen) |
199 | { |
200 | #ifdef IPV6 |
201 | if (addr->family == AF_INET) { |
202 | #endif |
203 | struct in_addr a; |
204 | a.s_addr = htonl(addr->address); |
205 | strncpy(buf, inet_ntoa(a), buflen); |
206 | #ifdef IPV6 |
207 | } else { |
208 | FIXME; /* I don't know how to get a text form of an IPv6 address. */ |
209 | } |
210 | #endif |
211 | } |
212 | |
213 | int sk_addrtype(SockAddr addr) |
214 | { |
215 | return (addr->family == AF_INET ? ADDRTYPE_IPV4 : ADDRTYPE_IPV6); |
216 | } |
217 | |
218 | void sk_addrcopy(SockAddr addr, char *buf) |
219 | { |
220 | #ifdef IPV6 |
221 | if (addr->family == AF_INET) { |
222 | #endif |
223 | struct in_addr a; |
224 | a.s_addr = htonl(addr->address); |
225 | memcpy(buf, (char*) &a.s_addr, 4); |
226 | #ifdef IPV6 |
227 | } else { |
228 | memcpy(buf, (char*) addr->ai, 16); |
229 | } |
230 | #endif |
231 | } |
232 | |
233 | void sk_addr_free(SockAddr addr) |
234 | { |
235 | sfree(addr); |
236 | } |
237 | |
238 | static Plug sk_tcp_plug(Socket sock, Plug p) |
239 | { |
240 | Actual_Socket s = (Actual_Socket) sock; |
241 | Plug ret = s->plug; |
242 | if (p) |
243 | s->plug = p; |
244 | return ret; |
245 | } |
246 | |
247 | static void sk_tcp_flush(Socket s) |
248 | { |
249 | /* |
250 | * We send data to the socket as soon as we can anyway, |
251 | * so we don't need to do anything here. :-) |
252 | */ |
253 | } |
254 | |
255 | static void sk_tcp_close(Socket s); |
256 | static int sk_tcp_write(Socket s, char *data, int len); |
257 | static int sk_tcp_write_oob(Socket s, char *data, int len); |
258 | static void sk_tcp_set_private_ptr(Socket s, void *ptr); |
259 | static void *sk_tcp_get_private_ptr(Socket s); |
260 | static void sk_tcp_set_frozen(Socket s, int is_frozen); |
261 | static char *sk_tcp_socket_error(Socket s); |
262 | |
263 | Socket sk_register(void *sock, Plug plug) |
264 | { |
265 | static struct socket_function_table fn_table = { |
266 | sk_tcp_plug, |
267 | sk_tcp_close, |
268 | sk_tcp_write, |
269 | sk_tcp_write_oob, |
270 | sk_tcp_flush, |
271 | sk_tcp_set_private_ptr, |
272 | sk_tcp_get_private_ptr, |
273 | sk_tcp_set_frozen, |
274 | sk_tcp_socket_error |
275 | }; |
276 | |
277 | Actual_Socket ret; |
278 | |
279 | /* |
280 | * Create Socket structure. |
281 | */ |
282 | ret = smalloc(sizeof(struct Socket_tag)); |
283 | ret->fn = &fn_table; |
284 | ret->error = NULL; |
285 | ret->plug = plug; |
286 | bufchain_init(&ret->output_data); |
287 | ret->writable = 1; /* to start with */ |
288 | ret->sending_oob = 0; |
289 | ret->frozen = 1; |
290 | ret->frozen_readable = 0; |
291 | ret->localhost_only = 0; /* unused, but best init anyway */ |
292 | ret->pending_error = 0; |
293 | ret->oobpending = FALSE; |
294 | ret->listener = 0; |
295 | |
296 | ret->s = (int)sock; |
297 | |
298 | if (ret->s < 0) { |
299 | ret->error = error_string(errno); |
300 | return (Socket) ret; |
301 | } |
302 | |
303 | ret->oobinline = 0; |
304 | |
305 | add234(sktree, ret); |
306 | |
307 | return (Socket) ret; |
308 | } |
309 | |
310 | Socket sk_new(SockAddr addr, int port, int privport, int oobinline, |
311 | int nodelay, Plug plug) |
312 | { |
313 | static struct socket_function_table fn_table = { |
314 | sk_tcp_plug, |
315 | sk_tcp_close, |
316 | sk_tcp_write, |
317 | sk_tcp_write_oob, |
318 | sk_tcp_flush, |
319 | sk_tcp_set_private_ptr, |
320 | sk_tcp_get_private_ptr, |
321 | sk_tcp_set_frozen, |
322 | sk_tcp_socket_error |
323 | }; |
324 | |
325 | int s; |
326 | #ifdef IPV6 |
327 | struct sockaddr_in6 a6; |
328 | #endif |
329 | struct sockaddr_in a; |
330 | int err; |
331 | Actual_Socket ret; |
332 | short localport; |
333 | |
334 | /* |
335 | * Create Socket structure. |
336 | */ |
337 | ret = smalloc(sizeof(struct Socket_tag)); |
338 | ret->fn = &fn_table; |
339 | ret->error = NULL; |
340 | ret->plug = plug; |
341 | bufchain_init(&ret->output_data); |
342 | ret->connected = 0; /* to start with */ |
343 | ret->writable = 0; /* to start with */ |
344 | ret->sending_oob = 0; |
345 | ret->frozen = 0; |
346 | ret->frozen_readable = 0; |
347 | ret->localhost_only = 0; /* unused, but best init anyway */ |
348 | ret->pending_error = 0; |
349 | ret->oobpending = FALSE; |
350 | ret->listener = 0; |
351 | |
352 | /* |
353 | * Open socket. |
354 | */ |
355 | s = socket(addr->family, SOCK_STREAM, 0); |
356 | ret->s = s; |
357 | |
358 | if (s < 0) { |
359 | ret->error = error_string(errno); |
360 | return (Socket) ret; |
361 | } |
362 | |
363 | ret->oobinline = oobinline; |
364 | if (oobinline) { |
365 | int b = TRUE; |
366 | setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (void *) &b, sizeof(b)); |
367 | } |
368 | |
369 | if (nodelay) { |
370 | int b = TRUE; |
371 | setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (void *) &b, sizeof(b)); |
372 | } |
373 | |
374 | /* |
375 | * Bind to local address. |
376 | */ |
377 | if (privport) |
378 | localport = 1023; /* count from 1023 downwards */ |
379 | else |
380 | localport = 0; /* just use port 0 (ie kernel picks) */ |
381 | |
382 | /* Loop round trying to bind */ |
383 | while (1) { |
384 | int retcode; |
385 | |
386 | #ifdef IPV6 |
387 | if (addr->family == AF_INET6) { |
388 | memset(&a6, 0, sizeof(a6)); |
389 | a6.sin6_family = AF_INET6; |
390 | /*a6.sin6_addr = in6addr_any; *//* == 0 */ |
391 | a6.sin6_port = htons(localport); |
392 | } else |
393 | #endif |
394 | { |
395 | a.sin_family = AF_INET; |
396 | a.sin_addr.s_addr = htonl(INADDR_ANY); |
397 | a.sin_port = htons(localport); |
398 | } |
399 | #ifdef IPV6 |
400 | retcode = bind(s, (addr->family == AF_INET6 ? |
401 | (struct sockaddr *) &a6 : |
402 | (struct sockaddr *) &a), |
403 | (addr->family == |
404 | AF_INET6 ? sizeof(a6) : sizeof(a))); |
405 | #else |
406 | retcode = bind(s, (struct sockaddr *) &a, sizeof(a)); |
407 | #endif |
408 | if (retcode >= 0) { |
409 | err = 0; |
410 | break; /* done */ |
411 | } else { |
412 | err = errno; |
413 | if (err != EADDRINUSE) /* failed, for a bad reason */ |
414 | break; |
415 | } |
416 | |
417 | if (localport == 0) |
418 | break; /* we're only looping once */ |
419 | localport--; |
420 | if (localport == 0) |
421 | break; /* we might have got to the end */ |
422 | } |
423 | |
424 | if (err) { |
425 | ret->error = error_string(err); |
426 | return (Socket) ret; |
427 | } |
428 | |
429 | /* |
430 | * Connect to remote address. |
431 | */ |
432 | #ifdef IPV6 |
433 | if (addr->family == AF_INET6) { |
434 | memset(&a, 0, sizeof(a)); |
435 | a6.sin6_family = AF_INET6; |
436 | a6.sin6_port = htons((short) port); |
437 | a6.sin6_addr = |
438 | ((struct sockaddr_in6 *) addr->ai->ai_addr)->sin6_addr; |
439 | } else |
440 | #endif |
441 | { |
442 | a.sin_family = AF_INET; |
443 | a.sin_addr.s_addr = htonl(addr->address); |
444 | a.sin_port = htons((short) port); |
445 | } |
446 | |
447 | if (( |
448 | #ifdef IPV6 |
449 | connect(s, ((addr->family == AF_INET6) ? |
450 | (struct sockaddr *) &a6 : (struct sockaddr *) &a), |
451 | (addr->family == AF_INET6) ? sizeof(a6) : sizeof(a)) |
452 | #else |
453 | connect(s, (struct sockaddr *) &a, sizeof(a)) |
454 | #endif |
455 | ) < 0) { |
456 | /* |
457 | * FIXME: We are prepared to receive EWOULDBLOCK here, |
458 | * because we might want the connection to be made |
459 | * asynchronously; but how do we actually arrange this in |
460 | * Unix? I forget. |
461 | */ |
462 | if ( errno != EWOULDBLOCK ) { |
463 | ret->error = error_string(errno); |
464 | return (Socket) ret; |
465 | } |
466 | } else { |
467 | /* |
468 | * If we _don't_ get EWOULDBLOCK, the connect has completed |
469 | * and we should set the socket as connected and writable. |
470 | */ |
471 | ret->connected = 1; |
472 | ret->writable = 1; |
473 | } |
474 | |
475 | add234(sktree, ret); |
476 | |
477 | return (Socket) ret; |
478 | } |
479 | |
480 | Socket sk_newlistener(int port, Plug plug, int local_host_only) |
481 | { |
482 | static struct socket_function_table fn_table = { |
483 | sk_tcp_plug, |
484 | sk_tcp_close, |
485 | sk_tcp_write, |
486 | sk_tcp_write_oob, |
487 | sk_tcp_flush, |
488 | sk_tcp_set_private_ptr, |
489 | sk_tcp_get_private_ptr, |
490 | sk_tcp_set_frozen, |
491 | sk_tcp_socket_error |
492 | }; |
493 | |
494 | int s; |
495 | #ifdef IPV6 |
496 | struct sockaddr_in6 a6; |
497 | #endif |
498 | struct sockaddr_in a; |
499 | int err; |
500 | Actual_Socket ret; |
501 | int retcode; |
502 | int on = 1; |
503 | |
504 | /* |
505 | * Create Socket structure. |
506 | */ |
507 | ret = smalloc(sizeof(struct Socket_tag)); |
508 | ret->fn = &fn_table; |
509 | ret->error = NULL; |
510 | ret->plug = plug; |
511 | bufchain_init(&ret->output_data); |
512 | ret->writable = 0; /* to start with */ |
513 | ret->sending_oob = 0; |
514 | ret->frozen = 0; |
515 | ret->frozen_readable = 0; |
516 | ret->localhost_only = local_host_only; |
517 | ret->pending_error = 0; |
518 | ret->oobpending = FALSE; |
519 | ret->listener = 1; |
520 | |
521 | /* |
522 | * Open socket. |
523 | */ |
524 | s = socket(AF_INET, SOCK_STREAM, 0); |
525 | ret->s = s; |
526 | |
527 | if (s < 0) { |
528 | ret->error = error_string(errno); |
529 | return (Socket) ret; |
530 | } |
531 | |
532 | ret->oobinline = 0; |
533 | |
534 | setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on)); |
535 | |
536 | #ifdef IPV6 |
537 | if (addr->family == AF_INET6) { |
538 | memset(&a6, 0, sizeof(a6)); |
539 | a6.sin6_family = AF_INET6; |
540 | if (local_host_only) |
541 | a6.sin6_addr = in6addr_loopback; |
542 | else |
543 | a6.sin6_addr = in6addr_any; |
544 | a6.sin6_port = htons(port); |
545 | } else |
546 | #endif |
547 | { |
548 | a.sin_family = AF_INET; |
549 | if (local_host_only) |
550 | a.sin_addr.s_addr = htonl(INADDR_LOOPBACK); |
551 | else |
552 | a.sin_addr.s_addr = htonl(INADDR_ANY); |
553 | a.sin_port = htons((short)port); |
554 | } |
555 | #ifdef IPV6 |
556 | retcode = bind(s, (addr->family == AF_INET6 ? |
557 | (struct sockaddr *) &a6 : |
558 | (struct sockaddr *) &a), |
559 | (addr->family == |
560 | AF_INET6 ? sizeof(a6) : sizeof(a))); |
561 | #else |
562 | retcode = bind(s, (struct sockaddr *) &a, sizeof(a)); |
563 | #endif |
564 | if (retcode >= 0) { |
565 | err = 0; |
566 | } else { |
567 | err = errno; |
568 | } |
569 | |
570 | if (err) { |
571 | ret->error = error_string(err); |
572 | return (Socket) ret; |
573 | } |
574 | |
575 | |
576 | if (listen(s, SOMAXCONN) < 0) { |
577 | close(s); |
578 | ret->error = error_string(errno); |
579 | return (Socket) ret; |
580 | } |
581 | |
582 | add234(sktree, ret); |
583 | |
584 | return (Socket) ret; |
585 | } |
586 | |
587 | static void sk_tcp_close(Socket sock) |
588 | { |
589 | Actual_Socket s = (Actual_Socket) sock; |
590 | |
591 | del234(sktree, s); |
592 | close(s->s); |
593 | sfree(s); |
594 | } |
595 | |
596 | /* |
597 | * The function which tries to send on a socket once it's deemed |
598 | * writable. |
599 | */ |
600 | void try_send(Actual_Socket s) |
601 | { |
602 | while (s->sending_oob || bufchain_size(&s->output_data) > 0) { |
603 | int nsent; |
604 | int err; |
605 | void *data; |
606 | int len, urgentflag; |
607 | |
608 | if (s->sending_oob) { |
609 | urgentflag = MSG_OOB; |
610 | len = s->sending_oob; |
611 | data = &s->oobdata; |
612 | } else { |
613 | urgentflag = 0; |
614 | bufchain_prefix(&s->output_data, &data, &len); |
615 | } |
616 | nsent = send(s->s, data, len, urgentflag); |
617 | noise_ultralight(nsent); |
618 | if (nsent <= 0) { |
619 | err = (nsent < 0 ? errno : 0); |
620 | if (err == EWOULDBLOCK) { |
621 | /* |
622 | * Perfectly normal: we've sent all we can for the moment. |
623 | */ |
624 | s->writable = FALSE; |
625 | return; |
626 | } else if (nsent == 0 || |
627 | err == ECONNABORTED || err == ECONNRESET) { |
628 | /* |
629 | * If send() returns CONNABORTED or CONNRESET, we |
630 | * unfortunately can't just call plug_closing(), |
631 | * because it's quite likely that we're currently |
632 | * _in_ a call from the code we'd be calling back |
633 | * to, so we'd have to make half the SSH code |
634 | * reentrant. Instead we flag a pending error on |
635 | * the socket, to be dealt with (by calling |
636 | * plug_closing()) at some suitable future moment. |
637 | */ |
638 | s->pending_error = err; |
639 | return; |
640 | } else { |
641 | /* We're inside the Unix frontend here, so we know |
642 | * that the frontend handle is unnecessary. */ |
643 | logevent(NULL, error_string(err)); |
644 | fatalbox("%s", error_string(err)); |
645 | } |
646 | } else { |
647 | if (s->sending_oob) { |
648 | if (nsent < len) { |
649 | memmove(s->oobdata, s->oobdata+nsent, len-nsent); |
650 | s->sending_oob = len - nsent; |
651 | } else { |
652 | s->sending_oob = 0; |
653 | } |
654 | } else { |
655 | bufchain_consume(&s->output_data, nsent); |
656 | } |
657 | } |
658 | } |
659 | } |
660 | |
661 | static int sk_tcp_write(Socket sock, char *buf, int len) |
662 | { |
663 | Actual_Socket s = (Actual_Socket) sock; |
664 | |
665 | /* |
666 | * Add the data to the buffer list on the socket. |
667 | */ |
668 | bufchain_add(&s->output_data, buf, len); |
669 | |
670 | /* |
671 | * Now try sending from the start of the buffer list. |
672 | */ |
673 | if (s->writable) |
674 | try_send(s); |
675 | |
676 | return bufchain_size(&s->output_data); |
677 | } |
678 | |
679 | static int sk_tcp_write_oob(Socket sock, char *buf, int len) |
680 | { |
681 | Actual_Socket s = (Actual_Socket) sock; |
682 | |
683 | /* |
684 | * Replace the buffer list on the socket with the data. |
685 | */ |
686 | bufchain_clear(&s->output_data); |
687 | assert(len <= sizeof(s->oobdata)); |
688 | memcpy(s->oobdata, buf, len); |
689 | s->sending_oob = len; |
690 | |
691 | /* |
692 | * Now try sending from the start of the buffer list. |
693 | */ |
694 | if (s->writable) |
695 | try_send(s); |
696 | |
697 | return s->sending_oob; |
698 | } |
699 | |
700 | int select_result(int fd, int event) |
701 | { |
702 | int ret; |
703 | int err; |
704 | char buf[20480]; /* nice big buffer for plenty of speed */ |
705 | Actual_Socket s; |
706 | u_long atmark; |
707 | |
708 | /* Find the Socket structure */ |
709 | s = find234(sktree, (void *) fd, cmpforsearch); |
710 | if (!s) |
711 | return 1; /* boggle */ |
712 | |
713 | noise_ultralight(event); |
714 | |
715 | switch (event) { |
716 | #ifdef FIXME_NONBLOCKING_CONNECTIONS |
717 | case FIXME: /* connected */ |
718 | s->connected = s->writable = 1; |
719 | break; |
720 | #endif |
721 | case 4: /* exceptional */ |
722 | if (!s->oobinline) { |
723 | /* |
724 | * On a non-oobinline socket, this indicates that we |
725 | * can immediately perform an OOB read and get back OOB |
726 | * data, which we will send to the back end with |
727 | * type==2 (urgent data). |
728 | */ |
729 | ret = recv(s->s, buf, sizeof(buf), MSG_OOB); |
730 | noise_ultralight(ret); |
731 | if (ret <= 0) { |
732 | char *str = (ret == 0 ? "Internal networking trouble" : |
733 | error_string(errno)); |
734 | /* We're inside the Unix frontend here, so we know |
735 | * that the frontend handle is unnecessary. */ |
736 | logevent(NULL, str); |
737 | fatalbox("%s", str); |
738 | } else { |
739 | return plug_receive(s->plug, 2, buf, ret); |
740 | } |
741 | break; |
742 | } |
743 | |
744 | /* |
745 | * If we reach here, this is an oobinline socket, which |
56e5b2db |
746 | * means we should set s->oobpending and then deal with it |
747 | * when we get called for the readability event (which |
748 | * should also occur). |
c5e438ec |
749 | */ |
750 | s->oobpending = TRUE; |
56e5b2db |
751 | break; |
c5e438ec |
752 | case 1: /* readable; also acceptance */ |
753 | if (s->listener) { |
754 | /* |
755 | * On a listening socket, the readability event means a |
756 | * connection is ready to be accepted. |
757 | */ |
758 | struct sockaddr_in isa; |
759 | int addrlen = sizeof(struct sockaddr_in); |
760 | int t; /* socket of connection */ |
761 | |
762 | memset(&isa, 0, sizeof(struct sockaddr_in)); |
763 | err = 0; |
764 | t = accept(s->s,(struct sockaddr *)&isa,&addrlen); |
765 | if (t < 0) { |
766 | break; |
767 | } |
768 | |
769 | if (s->localhost_only && |
770 | ntohl(isa.sin_addr.s_addr) != INADDR_LOOPBACK) { |
771 | close(t); /* someone let nonlocal through?! */ |
772 | } else if (plug_accepting(s->plug, (void*)t)) { |
773 | close(t); /* denied or error */ |
774 | } |
775 | break; |
776 | } |
777 | |
778 | /* |
779 | * If we reach here, this is not a listening socket, so |
780 | * readability really means readability. |
781 | */ |
782 | |
783 | /* In the case the socket is still frozen, we don't even bother */ |
784 | if (s->frozen) { |
785 | s->frozen_readable = 1; |
786 | break; |
787 | } |
788 | |
789 | /* |
790 | * We have received data on the socket. For an oobinline |
791 | * socket, this might be data _before_ an urgent pointer, |
792 | * in which case we send it to the back end with type==1 |
793 | * (data prior to urgent). |
794 | */ |
795 | if (s->oobinline && s->oobpending) { |
796 | atmark = 1; |
797 | if (ioctl(s->s, SIOCATMARK, &atmark) == 0 && atmark) |
798 | s->oobpending = FALSE; /* clear this indicator */ |
799 | } else |
800 | atmark = 1; |
801 | |
56e5b2db |
802 | ret = recv(s->s, buf, s->oobpending ? 1 : sizeof(buf), 0); |
c5e438ec |
803 | noise_ultralight(ret); |
804 | if (ret < 0) { |
805 | if (errno == EWOULDBLOCK) { |
806 | break; |
807 | } |
808 | } |
809 | if (ret < 0) { |
810 | return plug_closing(s->plug, error_string(errno), errno, 0); |
811 | } else if (0 == ret) { |
812 | return plug_closing(s->plug, NULL, 0, 0); |
813 | } else { |
814 | return plug_receive(s->plug, atmark ? 0 : 1, buf, ret); |
815 | } |
816 | break; |
817 | case 2: /* writable */ |
818 | { |
819 | int bufsize_before, bufsize_after; |
820 | s->writable = 1; |
821 | bufsize_before = s->sending_oob + bufchain_size(&s->output_data); |
822 | try_send(s); |
823 | bufsize_after = s->sending_oob + bufchain_size(&s->output_data); |
824 | if (bufsize_after < bufsize_before) |
825 | plug_sent(s->plug, bufsize_after); |
826 | } |
827 | break; |
828 | } |
829 | |
830 | return 1; |
831 | } |
832 | |
833 | /* |
834 | * Deal with socket errors detected in try_send(). |
835 | */ |
836 | void net_pending_errors(void) |
837 | { |
838 | int i; |
839 | Actual_Socket s; |
840 | |
841 | /* |
842 | * This might be a fiddly business, because it's just possible |
843 | * that handling a pending error on one socket might cause |
844 | * others to be closed. (I can't think of any reason this might |
845 | * happen in current SSH implementation, but to maintain |
846 | * generality of this network layer I'll assume the worst.) |
847 | * |
848 | * So what we'll do is search the socket list for _one_ socket |
849 | * with a pending error, and then handle it, and then search |
850 | * the list again _from the beginning_. Repeat until we make a |
851 | * pass with no socket errors present. That way we are |
852 | * protected against the socket list changing under our feet. |
853 | */ |
854 | |
855 | do { |
856 | for (i = 0; (s = index234(sktree, i)) != NULL; i++) { |
857 | if (s->pending_error) { |
858 | /* |
859 | * An error has occurred on this socket. Pass it to the |
860 | * plug. |
861 | */ |
862 | plug_closing(s->plug, error_string(s->pending_error), |
863 | s->pending_error, 0); |
864 | break; |
865 | } |
866 | } |
867 | } while (s); |
868 | } |
869 | |
870 | /* |
871 | * Each socket abstraction contains a `void *' private field in |
872 | * which the client can keep state. |
873 | */ |
874 | static void sk_tcp_set_private_ptr(Socket sock, void *ptr) |
875 | { |
876 | Actual_Socket s = (Actual_Socket) sock; |
877 | s->private_ptr = ptr; |
878 | } |
879 | |
880 | static void *sk_tcp_get_private_ptr(Socket sock) |
881 | { |
882 | Actual_Socket s = (Actual_Socket) sock; |
883 | return s->private_ptr; |
884 | } |
885 | |
886 | /* |
887 | * Special error values are returned from sk_namelookup and sk_new |
888 | * if there's a problem. These functions extract an error message, |
889 | * or return NULL if there's no problem. |
890 | */ |
891 | char *sk_addr_error(SockAddr addr) |
892 | { |
893 | return addr->error; |
894 | } |
895 | static char *sk_tcp_socket_error(Socket sock) |
896 | { |
897 | Actual_Socket s = (Actual_Socket) sock; |
898 | return s->error; |
899 | } |
900 | |
901 | static void sk_tcp_set_frozen(Socket sock, int is_frozen) |
902 | { |
903 | Actual_Socket s = (Actual_Socket) sock; |
904 | if (s->frozen == is_frozen) |
905 | return; |
906 | s->frozen = is_frozen; |
907 | if (!is_frozen && s->frozen_readable) { |
908 | char c; |
909 | recv(s->s, &c, 1, MSG_PEEK); |
910 | } |
911 | s->frozen_readable = 0; |
912 | } |
913 | |
914 | /* |
915 | * For Unix select()-based frontends: enumerate all sockets |
916 | * currently active, and state whether we currently wish to receive |
917 | * select events on them for reading, writing and exceptional |
918 | * status. |
919 | */ |
920 | static void set_rwx(Actual_Socket s, int *rwx) |
921 | { |
922 | int val = 0; |
923 | if (s->connected && !s->frozen) |
924 | val |= 1 | 4; /* read, except */ |
925 | if (bufchain_size(&s->output_data)) |
926 | val |= 2; /* write */ |
927 | if (s->listener) |
928 | val |= 1; /* read == accept */ |
929 | *rwx = val; |
930 | } |
931 | |
932 | int first_socket(int *state, int *rwx) |
933 | { |
934 | Actual_Socket s; |
935 | *state = 0; |
936 | s = index234(sktree, (*state)++); |
937 | if (s) |
938 | set_rwx(s, rwx); |
939 | return s ? s->s : -1; |
940 | } |
941 | |
942 | int next_socket(int *state, int *rwx) |
943 | { |
944 | Actual_Socket s = index234(sktree, (*state)++); |
945 | if (s) |
946 | set_rwx(s, rwx); |
947 | return s ? s->s : -1; |
948 | } |
949 | |
950 | int net_service_lookup(char *service) |
951 | { |
952 | struct servent *se; |
953 | se = getservbyname(service, NULL); |
954 | if (se != NULL) |
955 | return ntohs(se->s_port); |
956 | else |
957 | return 0; |
958 | } |