Debug: provide for SIGALRM tracking
[exim.git] / src / src / ip.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
8 /* Functions for doing things with sockets. With the advent of IPv6 this has
9 got messier, so that it's worth pulling out the code into separate functions
10 that other parts of Exim can call, especially as there are now several
11 different places in the code where sockets are used. */
12
13
14 #include "exim.h"
15
16
17 /*************************************************
18 * Create a socket *
19 *************************************************/
20
21 /* Socket creation happens in a number of places so it's packaged here for
22 convenience.
23
24 Arguments:
25 type SOCK_DGRAM or SOCK_STREAM
26 af AF_INET or AF_INET6
27
28 Returns: socket number or -1 on failure
29 */
30
31 int
32 ip_socket(int type, int af)
33 {
34 int sock = socket(af, type, 0);
35 if (sock < 0)
36 log_write(0, LOG_MAIN, "IPv%c socket creation failed: %s",
37 (af == AF_INET6)? '6':'4', strerror(errno));
38 return sock;
39 }
40
41
42
43
44 #if HAVE_IPV6
45 /*************************************************
46 * Convert printing address to numeric *
47 *************************************************/
48
49 /* This function converts the textual form of an IP address into a numeric form
50 in an appropriate structure in an IPv6 environment. The getaddrinfo() function
51 can (apparently) handle more complicated addresses (e.g. those containing
52 scopes) than inet_pton() in some environments. We use hints to tell it that the
53 input must be a numeric address.
54
55 However, apparently some operating systems (or libraries) don't support
56 getaddrinfo(), so there is a build-time option to revert to inet_pton() (which
57 does not support scopes).
58
59 Arguments:
60 address textual form of the address
61 addr where to copy back the answer
62
63 Returns: nothing - failure provokes a panic-die
64 */
65
66 static void
67 ip_addrinfo(const uschar *address, struct sockaddr_in6 *saddr)
68 {
69 #ifdef IPV6_USE_INET_PTON
70
71 if (inet_pton(AF_INET6, CCS address, &saddr->sin6_addr) != 1)
72 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "unable to parse \"%s\" as an "
73 "IP address", address);
74 saddr->sin6_family = AF_INET6;
75
76 #else
77
78 int rc;
79 struct addrinfo hints, *res;
80 memset(&hints, 0, sizeof(hints));
81 hints.ai_family = AF_INET6;
82 hints.ai_socktype = SOCK_STREAM;
83 hints.ai_flags = AI_NUMERICHOST;
84 if ((rc = getaddrinfo(CCS address, NULL, &hints, &res)) != 0 || res == NULL)
85 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "unable to parse \"%s\" as an "
86 "IP address: %s", address,
87 (rc == 0)? "NULL result returned" : gai_strerror(rc));
88 memcpy(saddr, res->ai_addr, res->ai_addrlen);
89 freeaddrinfo(res);
90
91 #endif
92 }
93 #endif /* HAVE_IPV6 */
94
95
96 /*************************************************
97 * Bind socket to interface and port *
98 *************************************************/
99
100 int
101 ip_addr(void * sin_, int af, const uschar * address, int port)
102 {
103 union sockaddr_46 * sin = sin_;
104 memset(sin, 0, sizeof(*sin));
105
106 /* Setup code when using an IPv6 socket. The wildcard address is ":", to
107 ensure an IPv6 socket is used. */
108
109 #if HAVE_IPV6
110 if (af == AF_INET6)
111 {
112 if (address[0] == ':' && address[1] == 0)
113 {
114 sin->v6.sin6_family = AF_INET6;
115 sin->v6.sin6_addr = in6addr_any;
116 }
117 else
118 ip_addrinfo(address, &sin->v6); /* Panic-dies on error */
119 sin->v6.sin6_port = htons(port);
120 return sizeof(sin->v6);
121 }
122 else
123 #else /* HAVE_IPv6 */
124 af = af; /* Avoid compiler warning */
125 #endif /* HAVE_IPV6 */
126
127 /* Setup code when using IPv4 socket. The wildcard address is "". */
128
129 {
130 sin->v4.sin_family = AF_INET;
131 sin->v4.sin_port = htons(port);
132 sin->v4.sin_addr.s_addr = address[0] == 0
133 ? (S_ADDR_TYPE)INADDR_ANY
134 : (S_ADDR_TYPE)inet_addr(CS address);
135 return sizeof(sin->v4);
136 }
137 }
138
139
140
141 /* This function binds a socket to a local interface address and port. For a
142 wildcard IPv6 bind, the address is ":".
143
144 Arguments:
145 sock the socket
146 af AF_INET or AF_INET6 - the socket type
147 address the IP address, in text form
148 port the IP port (host order)
149
150 Returns: the result of bind()
151 */
152
153 int
154 ip_bind(int sock, int af, uschar *address, int port)
155 {
156 union sockaddr_46 sin;
157 int s_len = ip_addr(&sin, af, address, port);
158 return bind(sock, (struct sockaddr *)&sin, s_len);
159 }
160
161
162
163 /*************************************************
164 *************************************************/
165
166 #ifdef EXIM_TFO_PROBE
167 void
168 tfo_probe(void)
169 {
170 # ifdef TCP_FASTOPEN
171 int sock, backlog = 5;
172
173 if ( (sock = socket(SOCK_STREAM, AF_INET, 0)) < 0
174 && setsockopt(sock, IPPROTO_TCP, TCP_FASTOPEN, &backlog, sizeof(backlog))
175 )
176 f.tcp_fastopen_ok = TRUE;
177 close(sock);
178 # endif
179 }
180 #endif
181
182
183 /*************************************************
184 * Connect socket to remote host *
185 *************************************************/
186
187 /* This function connects a socket to a remote address and port. The socket may
188 or may not have previously been bound to a local interface. The socket is not
189 closed, even in cases of error. It is expected that the calling function, which
190 created the socket, will be the one that closes it.
191
192 Arguments:
193 sock the socket
194 af AF_INET6 or AF_INET for the socket type
195 address the remote address, in text form
196 port the remote port
197 timeout a timeout (zero for indefinite timeout)
198 fastopen_blob non-null iff TCP_FASTOPEN can be used; may indicate early-data to
199 be sent in SYN segment
200
201 Returns: 0 on success; -1 on failure, with errno set
202 */
203
204 int
205 ip_connect(int sock, int af, const uschar *address, int port, int timeout,
206 const blob * fastopen_blob)
207 {
208 struct sockaddr_in s_in4;
209 struct sockaddr *s_ptr;
210 int s_len, rc, save_errno;
211
212 /* For an IPv6 address, use an IPv6 sockaddr structure. */
213
214 #if HAVE_IPV6
215 struct sockaddr_in6 s_in6;
216 if (af == AF_INET6)
217 {
218 memset(&s_in6, 0, sizeof(s_in6));
219 ip_addrinfo(address, &s_in6); /* Panic-dies on error */
220 s_in6.sin6_port = htons(port);
221 s_ptr = (struct sockaddr *)&s_in6;
222 s_len = sizeof(s_in6);
223 }
224 else
225 #else /* HAVE_IPV6 */
226 af = af; /* Avoid compiler warning */
227 #endif /* HAVE_IPV6 */
228
229 /* For an IPv4 address, use an IPv4 sockaddr structure, even on a system with
230 IPv6 support. */
231
232 {
233 memset(&s_in4, 0, sizeof(s_in4));
234 s_in4.sin_family = AF_INET;
235 s_in4.sin_port = htons(port);
236 s_in4.sin_addr.s_addr = (S_ADDR_TYPE)inet_addr(CCS address);
237 s_ptr = (struct sockaddr *)&s_in4;
238 s_len = sizeof(s_in4);
239 }
240
241 /* If no connection timeout is set, just call connect() without setting a
242 timer, thereby allowing the inbuilt OS timeout to operate. */
243
244 callout_address = string_sprintf("[%s]:%d", address, port);
245 sigalrm_seen = FALSE;
246 if (timeout > 0) ALARM(timeout);
247
248 #if defined(TCP_FASTOPEN) && defined(MSG_FASTOPEN)
249 /* TCP Fast Open, if the system has a cookie from a previous call to
250 this peer, can send data in the SYN packet. The peer can send data
251 before it gets our ACK of its SYN,ACK - the latter is useful for
252 the SMTP banner. Other (than SMTP) cases of TCP connections can
253 possibly use the data-on-syn, so support that too.
254
255 This is a Linux implementation. It might be useable on FreeBSD; I have
256 not checked. I think MacOS has a "connectx" call for this purpose,
257 rather than using "sendto" ? */
258
259 if (fastopen_blob && f.tcp_fastopen_ok)
260 {
261 if ((rc = sendto(sock, fastopen_blob->data, fastopen_blob->len,
262 MSG_FASTOPEN | MSG_DONTWAIT, s_ptr, s_len)) >= 0)
263 /* seen for with-data, experimental TFO option, with-cookie case */
264 /* seen for with-data, proper TFO opt, with-cookie case */
265 {
266 DEBUG(D_transport|D_v)
267 debug_printf("non-TFO mode connection attempt to %s, %lu data\n",
268 address, (unsigned long)fastopen_blob->len);
269 /*XXX also seen on successful TFO, sigh */
270 tcp_out_fastopen = fastopen_blob->len > 0 ? TFO_USED : TFO_ATTEMPTED;
271 }
272 else if (errno == EINPROGRESS) /* expected if we had no cookie for peer */
273 /* seen for no-data, proper TFO option, both cookie-request and with-cookie cases */
274 /* apparently no visibility of the diffference at this point */
275 /* seen for with-data, proper TFO opt, cookie-req */
276 /* with netwk delay, post-conn tcp_info sees unacked 1 for R, 2 for C; code in smtp_out.c */
277 /* ? older Experimental TFO option behaviour ? */
278 { /* queue unsent data */
279 DEBUG(D_transport|D_v) debug_printf("TFO mode sendto, %s data: EINPROGRESS\n",
280 fastopen_blob->len > 0 ? "with" : "no");
281 if (!fastopen_blob->data)
282 {
283 tcp_out_fastopen = TFO_ATTEMPTED; /* we tried; unknown if useful yet */
284 rc = 0;
285 }
286 else
287 rc = send(sock, fastopen_blob->data, fastopen_blob->len, 0);
288 }
289 else if(errno == EOPNOTSUPP)
290 {
291 DEBUG(D_transport)
292 debug_printf("Tried TCP Fast Open but apparently not enabled by sysctl\n");
293 goto legacy_connect;
294 }
295 }
296 else
297 #endif
298 {
299 legacy_connect:
300 DEBUG(D_transport|D_v) if (fastopen_blob)
301 debug_printf("non-TFO mode connection attempt to %s, %lu data\n",
302 address, (unsigned long)fastopen_blob->len);
303 if ((rc = connect(sock, s_ptr, s_len)) >= 0)
304 if ( fastopen_blob && fastopen_blob->data && fastopen_blob->len
305 && send(sock, fastopen_blob->data, fastopen_blob->len, 0) < 0)
306 rc = -1;
307 }
308
309 save_errno = errno;
310 ALARM_CLR(0);
311
312 /* There is a testing facility for simulating a connection timeout, as I
313 can't think of any other way of doing this. It converts a connection refused
314 into a timeout if the timeout is set to 999999. */
315
316 if (f.running_in_test_harness && save_errno == ECONNREFUSED && timeout == 999999)
317 {
318 rc = -1;
319 save_errno = EINTR;
320 sigalrm_seen = TRUE;
321 }
322
323 /* Success */
324
325 if (rc >= 0)
326 return 0;
327
328 /* A failure whose error code is "Interrupted system call" is in fact
329 an externally applied timeout if the signal handler has been run. */
330
331 errno = save_errno == EINTR && sigalrm_seen ? ETIMEDOUT : save_errno;
332 return -1;
333 }
334
335
336
337 /*************************************************
338 * Create connected socket to remote host *
339 *************************************************/
340
341 /* Create a socket and connect to host (name or number, ipv6 ok)
342 at one of port-range.
343
344 Arguments:
345 type SOCK_DGRAM or SOCK_STREAM
346 af AF_INET6 or AF_INET for the socket type
347 hostname host name, or ip address (as text)
348 portlo,porthi the remote port range
349 timeout a timeout
350 connhost if not NULL, host_item to be filled in with connection details
351 errstr pointer for allocated string on error
352 fastopen_blob with SOCK_STREAM, if non-null, request TCP Fast Open.
353 Additionally, optional early-data to send
354
355 Return:
356 socket fd, or -1 on failure (having allocated an error string)
357 */
358 int
359 ip_connectedsocket(int type, const uschar * hostname, int portlo, int porthi,
360 int timeout, host_item * connhost, uschar ** errstr, const blob * fastopen_blob)
361 {
362 int namelen, port;
363 host_item shost;
364 host_item *h;
365 int af = 0, fd, fd4 = -1, fd6 = -1;
366
367 shost.next = NULL;
368 shost.address = NULL;
369 shost.port = portlo;
370 shost.mx = -1;
371
372 namelen = Ustrlen(hostname);
373
374 /* Anything enclosed in [] must be an IP address. */
375
376 if (hostname[0] == '[' &&
377 hostname[namelen - 1] == ']')
378 {
379 uschar * host = string_copyn(hostname+1, namelen-2);
380 if (string_is_ip_address(host, NULL) == 0)
381 {
382 *errstr = string_sprintf("malformed IP address \"%s\"", hostname);
383 return -1;
384 }
385 shost.name = shost.address = host;
386 }
387
388 /* Otherwise check for an unadorned IP address */
389
390 else if (string_is_ip_address(hostname, NULL) != 0)
391 shost.name = shost.address = string_copyn(hostname, namelen);
392
393 /* Otherwise lookup IP address(es) from the name */
394
395 else
396 {
397 shost.name = string_copyn(hostname, namelen);
398 if (host_find_byname(&shost, NULL, HOST_FIND_QUALIFY_SINGLE,
399 NULL, FALSE) != HOST_FOUND)
400 {
401 *errstr = string_sprintf("no IP address found for host %s", shost.name);
402 return -1;
403 }
404 }
405
406 /* Try to connect to the server - test each IP till one works */
407
408 for (h = &shost; h; h = h->next)
409 {
410 fd = Ustrchr(h->address, ':') != 0
411 ? fd6 < 0 ? (fd6 = ip_socket(type, af = AF_INET6)) : fd6
412 : fd4 < 0 ? (fd4 = ip_socket(type, af = AF_INET )) : fd4;
413
414 if (fd < 0)
415 {
416 *errstr = string_sprintf("failed to create socket: %s", strerror(errno));
417 goto bad;
418 }
419
420 for(port = portlo; port <= porthi; port++)
421 if (ip_connect(fd, af, h->address, port, timeout, fastopen_blob) == 0)
422 {
423 if (fd != fd6) close(fd6);
424 if (fd != fd4) close(fd4);
425 if (connhost)
426 {
427 h->port = port;
428 *connhost = *h;
429 connhost->next = NULL;
430 }
431 return fd;
432 }
433 }
434
435 *errstr = string_sprintf("failed to connect to any address for %s: %s",
436 hostname, strerror(errno));
437
438 bad:
439 close(fd4); close(fd6); return -1;
440 }
441
442
443 /*XXX TFO? */
444 int
445 ip_tcpsocket(const uschar * hostport, uschar ** errstr, int tmo)
446 {
447 int scan;
448 uschar hostname[256];
449 unsigned int portlow, porthigh;
450
451 /* extract host and port part */
452 scan = sscanf(CS hostport, "%255s %u-%u", hostname, &portlow, &porthigh);
453 if (scan != 3)
454 {
455 if (scan != 2)
456 {
457 *errstr = string_sprintf("invalid socket '%s'", hostport);
458 return -1;
459 }
460 porthigh = portlow;
461 }
462
463 return ip_connectedsocket(SOCK_STREAM, hostname, portlow, porthigh,
464 tmo, NULL, errstr, NULL);
465 }
466
467 int
468 ip_unixsocket(const uschar * path, uschar ** errstr)
469 {
470 int sock;
471 struct sockaddr_un server;
472
473 if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
474 {
475 *errstr = US"can't open UNIX socket.";
476 return -1;
477 }
478
479 callout_address = string_copy(path);
480 server.sun_family = AF_UNIX;
481 Ustrncpy(server.sun_path, path, sizeof(server.sun_path)-1);
482 server.sun_path[sizeof(server.sun_path)-1] = '\0';
483 if (connect(sock, (struct sockaddr *) &server, sizeof(server)) < 0)
484 {
485 int err = errno;
486 (void)close(sock);
487 *errstr = string_sprintf("unable to connect to UNIX socket (%s): %s",
488 path, strerror(err));
489 return -1;
490 }
491 return sock;
492 }
493
494 int
495 ip_streamsocket(const uschar * spec, uschar ** errstr, int tmo)
496 {
497 return *spec == '/'
498 ? ip_unixsocket(spec, errstr) : ip_tcpsocket(spec, errstr, tmo);
499 }
500
501 /*************************************************
502 * Set keepalive on a socket *
503 *************************************************/
504
505 /* Can be called for both incoming and outgoing sockets.
506
507 Arguments:
508 sock the socket
509 address the remote host address, for failure logging
510 torf true for outgoing connection, false for incoming
511
512 Returns: nothing
513 */
514
515 void
516 ip_keepalive(int sock, const uschar *address, BOOL torf)
517 {
518 int fodder = 1;
519 if (setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
520 US (&fodder), sizeof(fodder)) != 0)
521 log_write(0, LOG_MAIN, "setsockopt(SO_KEEPALIVE) on connection %s %s "
522 "failed: %s", torf? "to":"from", address, strerror(errno));
523 }
524
525
526
527 /*************************************************
528 * Receive from a socket with timeout *
529 *************************************************/
530
531 /*
532 Arguments:
533 fd the file descriptor
534 timeout the timeout, seconds
535 Returns: TRUE => ready for i/o
536 FALSE => timed out, or other error
537 */
538 BOOL
539 fd_ready(int fd, int timeout)
540 {
541 fd_set select_inset;
542 time_t start_recv = time(NULL);
543 int time_left = timeout;
544 int rc;
545
546 if (time_left <= 0)
547 {
548 errno = ETIMEDOUT;
549 return FALSE;
550 }
551 /* Wait until the socket is ready */
552
553 do
554 {
555 struct timeval tv = { .tv_sec = time_left, .tv_usec = 0 };
556 FD_ZERO (&select_inset);
557 FD_SET (fd, &select_inset);
558
559 /*DEBUG(D_transport) debug_printf("waiting for data on fd\n");*/
560 rc = select(fd + 1, (SELECT_ARG2_TYPE *)&select_inset, NULL, NULL, &tv);
561
562 /* If some interrupt arrived, just retry. We presume this to be rare,
563 but it can happen (e.g. the SIGUSR1 signal sent by exiwhat causes
564 select() to exit).
565
566 Aug 2004: Somebody set up a cron job that ran exiwhat every 2 minutes, making
567 the interrupt not at all rare. Since the timeout is typically more than 2
568 minutes, the effect was to block the timeout completely. To prevent this
569 happening again, we do an explicit time test and adjust the timeout
570 accordingly */
571
572 if (rc < 0 && errno == EINTR)
573 {
574 DEBUG(D_transport) debug_printf("EINTR while waiting for socket data\n");
575
576 /* Watch out, 'continue' jumps to the condition, not to the loops top */
577 time_left = timeout - (time(NULL) - start_recv);
578 if (time_left > 0) continue;
579 }
580
581 if (rc <= 0)
582 {
583 errno = ETIMEDOUT;
584 return FALSE;
585 }
586
587 /* Checking the FD_ISSET is not enough, if we're interrupted, the
588 select_inset may still contain the 'input'. */
589 }
590 while (rc < 0 || !FD_ISSET(fd, &select_inset));
591 return TRUE;
592 }
593
594 /* The timeout is implemented using select(), and we loop to cover select()
595 getting interrupted, and the possibility of select() returning with a positive
596 result but no ready descriptor. Is this in fact possible?
597
598 Arguments:
599 cctx the connection context (socket fd, possibly TLS context)
600 buffer to read into
601 bufsize the buffer size
602 timeout the timeout
603
604 Returns: > 0 => that much data read
605 <= 0 on error or EOF; errno set - zero for EOF
606 */
607
608 int
609 ip_recv(client_conn_ctx * cctx, uschar * buffer, int buffsize, int timeout)
610 {
611 int rc;
612
613 if (!fd_ready(cctx->sock, timeout))
614 return -1;
615
616 /* The socket is ready, read from it (via TLS if it's active). On EOF (i.e.
617 close down of the connection), set errno to zero; otherwise leave it alone. */
618
619 #ifdef SUPPORT_TLS
620 if (cctx->tls_ctx) /* client TLS */
621 rc = tls_read(cctx->tls_ctx, buffer, buffsize);
622 else if (tls_in.active.sock == cctx->sock) /* server TLS */
623 rc = tls_read(NULL, buffer, buffsize);
624 else
625 #endif
626 rc = recv(cctx->sock, buffer, buffsize, 0);
627
628 if (rc > 0) return rc;
629 if (rc == 0) errno = 0;
630 return -1;
631 }
632
633
634
635
636 /*************************************************
637 * Lookup address family of potential socket *
638 *************************************************/
639
640 /* Given a file-descriptor, check to see if it's a socket and, if so,
641 return the address family; detects IPv4 vs IPv6. If not a socket then
642 return -1.
643
644 The value 0 is typically AF_UNSPEC, which should not be seen on a connected
645 fd. If the return is -1, the errno will be from getsockname(); probably
646 ENOTSOCK or ECONNRESET.
647
648 Arguments: socket-or-not fd
649 Returns: address family or -1
650 */
651
652 int
653 ip_get_address_family(int fd)
654 {
655 struct sockaddr_storage ss;
656 socklen_t sslen = sizeof(ss);
657
658 if (getsockname(fd, (struct sockaddr *) &ss, &sslen) < 0)
659 return -1;
660
661 return (int) ss.ss_family;
662 }
663
664
665
666
667 /*************************************************
668 * Lookup DSCP settings for a socket *
669 *************************************************/
670
671 struct dscp_name_tableentry {
672 const uschar *name;
673 int value;
674 };
675 /* Keep both of these tables sorted! */
676 static struct dscp_name_tableentry dscp_table[] = {
677 #ifdef IPTOS_DSCP_AF11
678 { CUS"af11", IPTOS_DSCP_AF11 },
679 { CUS"af12", IPTOS_DSCP_AF12 },
680 { CUS"af13", IPTOS_DSCP_AF13 },
681 { CUS"af21", IPTOS_DSCP_AF21 },
682 { CUS"af22", IPTOS_DSCP_AF22 },
683 { CUS"af23", IPTOS_DSCP_AF23 },
684 { CUS"af31", IPTOS_DSCP_AF31 },
685 { CUS"af32", IPTOS_DSCP_AF32 },
686 { CUS"af33", IPTOS_DSCP_AF33 },
687 { CUS"af41", IPTOS_DSCP_AF41 },
688 { CUS"af42", IPTOS_DSCP_AF42 },
689 { CUS"af43", IPTOS_DSCP_AF43 },
690 { CUS"ef", IPTOS_DSCP_EF },
691 #endif
692 #ifdef IPTOS_LOWCOST
693 { CUS"lowcost", IPTOS_LOWCOST },
694 #endif
695 { CUS"lowdelay", IPTOS_LOWDELAY },
696 #ifdef IPTOS_MINCOST
697 { CUS"mincost", IPTOS_MINCOST },
698 #endif
699 { CUS"reliability", IPTOS_RELIABILITY },
700 { CUS"throughput", IPTOS_THROUGHPUT }
701 };
702 static int dscp_table_size =
703 sizeof(dscp_table) / sizeof(struct dscp_name_tableentry);
704
705 /* DSCP values change by protocol family, and so do the options used for
706 setsockopt(); this utility does all the lookups. It takes an unexpanded
707 option string, expands it, strips off affix whitespace, then checks if it's
708 a number. If all of what's left is a number, then that's how the option will
709 be parsed and success/failure is a range check. If it's not all a number,
710 then it must be a supported keyword.
711
712 Arguments:
713 dscp_name a string, so far unvalidated
714 af address_family in use
715 level setsockopt level to use
716 optname setsockopt name to use
717 dscp_value value for dscp_name
718
719 Returns: TRUE if okay to setsockopt(), else FALSE
720
721 *level and *optname may be set even if FALSE is returned
722 */
723
724 BOOL
725 dscp_lookup(const uschar *dscp_name, int af,
726 int *level, int *optname, int *dscp_value)
727 {
728 uschar *dscp_lookup, *p;
729 int first, last;
730 long rawlong;
731
732 if (af == AF_INET)
733 {
734 *level = IPPROTO_IP;
735 *optname = IP_TOS;
736 }
737 #if HAVE_IPV6 && defined(IPV6_TCLASS)
738 else if (af == AF_INET6)
739 {
740 *level = IPPROTO_IPV6;
741 *optname = IPV6_TCLASS;
742 }
743 #endif
744 else
745 {
746 DEBUG(D_transport)
747 debug_printf("Unhandled address family %d in dscp_lookup()\n", af);
748 return FALSE;
749 }
750 if (!dscp_name)
751 {
752 DEBUG(D_transport)
753 debug_printf("[empty DSCP]\n");
754 return FALSE;
755 }
756 dscp_lookup = expand_string(US dscp_name);
757 if (dscp_lookup == NULL || *dscp_lookup == '\0')
758 return FALSE;
759
760 p = dscp_lookup + Ustrlen(dscp_lookup) - 1;
761 while (isspace(*p)) *p-- = '\0';
762 while (isspace(*dscp_lookup) && dscp_lookup < p) dscp_lookup++;
763 if (*dscp_lookup == '\0')
764 return FALSE;
765
766 rawlong = Ustrtol(dscp_lookup, &p, 0);
767 if (p != dscp_lookup && *p == '\0')
768 {
769 /* We have six bits available, which will end up shifted to fit in 0xFC mask.
770 RFC 2597 defines the values unshifted. */
771 if (rawlong < 0 || rawlong > 0x3F)
772 {
773 DEBUG(D_transport)
774 debug_printf("DSCP value %ld out of range, ignored.\n", rawlong);
775 return FALSE;
776 }
777 *dscp_value = rawlong << 2;
778 return TRUE;
779 }
780
781 first = 0;
782 last = dscp_table_size;
783 while (last > first)
784 {
785 int middle = (first + last)/2;
786 int c = Ustrcmp(dscp_lookup, dscp_table[middle].name);
787 if (c == 0)
788 {
789 *dscp_value = dscp_table[middle].value;
790 return TRUE;
791 }
792 else if (c > 0)
793 first = middle + 1;
794 else
795 last = middle;
796 }
797 return FALSE;
798 }
799
800 void
801 dscp_list_to_stream(FILE *stream)
802 {
803 int i;
804 for (i=0; i < dscp_table_size; ++i)
805 fprintf(stream, "%s\n", dscp_table[i].name);
806 }
807
808
809 /* End of ip.c */
810 /* vi: aw ai sw=2
811 */