1 /* A little hacked up program that listens on a given port and allows a script
2 to play the part of a remote MTA for testing purposes. This scripted version is
3 hacked from my original interactive version. A further hack allows it to listen
4 on a Unix domain socket as an alternative to a TCP/IP port.
6 In an IPv6 world, listening happens on both an IPv6 and an IPv4 socket, always
7 on all interfaces, unless the option -noipv6 is given. */
9 /* ANSI C standard includes */
24 #include <sys/types.h>
26 #include <netinet/in_systm.h>
27 #include <netinet/in.h>
28 #include <netinet/ip.h>
29 #include <netinet/tcp.h>
31 #ifdef HAVE_NETINET_IP_VAR_H
32 # include <netinet/ip_var.h>
36 #include <arpa/inet.h>
38 #include <sys/resource.h>
39 #include <sys/socket.h>
51 # define S_ADDR_TYPE u_long
56 # define CCS (const char *)
66 typedef unsigned BOOL;
71 /*************************************************
72 * SIGALRM handler - crash out *
73 *************************************************/
77 sigalrm_handler(int sig)
79 sig = sig; /* Keep picky compilers happy */
80 printf("\nServer timed out\n");
81 exit(tmo_noerror ? 0 : 99);
85 /*************************************************
86 * Get textual IP address *
87 *************************************************/
89 /* This function is copied from Exim */
92 host_ntoa(const void *arg, char *buffer)
96 /* The new world. It is annoying that we have to fish out the address from
97 different places in the block, depending on what kind of address it is. It
98 is also a pain that inet_ntop() returns a const char *, whereas the IPv4
99 function inet_ntoa() returns just char *, and some picky compilers insist
100 on warning if one assigns a const char * to a char *. Hence the casts. */
103 char addr_buffer[46];
104 int family = ((struct sockaddr *)arg)->sa_family;
105 if (family == AF_INET6)
107 struct sockaddr_in6 *sk = (struct sockaddr_in6 *)arg;
108 yield = (char *)inet_ntop(family, &(sk->sin6_addr), addr_buffer,
109 sizeof(addr_buffer));
113 struct sockaddr_in *sk = (struct sockaddr_in *)arg;
114 yield = (char *)inet_ntop(family, &(sk->sin_addr), addr_buffer,
115 sizeof(addr_buffer));
118 /* If the result is a mapped IPv4 address, show it in V4 format. */
120 if (strncmp(yield, "::ffff:", 7) == 0) yield += 7;
122 #else /* HAVE_IPV6 */
126 yield = inet_ntoa(((struct sockaddr_in *)arg)->sin_addr);
129 strcpy(buffer, yield);
136 printit(char * s, int n)
140 unsigned char c = *s++;
143 else if (c >= ' ' && c <= '~') /* assumes ascii */
146 printf("\\x%02x", c);
153 /*************************************************
155 *************************************************/
157 #define v6n 0 /* IPv6 socket number */
158 #define v4n 1 /* IPv4 socket number */
159 #define udn 2 /* Unix domain socket number */
160 #define skn 2 /* Potential number of sockets */
162 int main(int argc, char **argv)
166 int listen_socket[3] = { -1, -1, -1 };
168 int dup_accept_socket;
169 int connection_count = 1;
173 int initial_pause = 0, tfo = 0;
183 char *pidfile = NULL;
185 char *sockname = NULL;
186 unsigned char buffer[10240];
188 struct sockaddr_un sockun; /* don't use "sun" */
189 struct sockaddr_un sockun_accepted;
190 int sockun_len = sizeof(sockun_accepted);
193 struct sockaddr_in6 sin6;
194 struct sockaddr_in6 accepted;
195 struct in6_addr anyaddr6 = IN6ADDR_ANY_INIT ;
197 struct sockaddr_in accepted;
200 /* Always need an IPv4 structure */
202 struct sockaddr_in sin4;
204 int len = sizeof(accepted);
207 /* Sort out the arguments */
208 if (argc > 1 && (!strcmp(argv[1], "--help") || !strcmp(argv[1], "-h")))
210 printf("Usage: %s [options] port|socket [connection count]\n", argv[0]);
213 "\n\t-i n n seconds initial delay"
214 "\n\t-noipv4 disable ipv4"
215 "\n\t-noipv6 disable ipv6"
216 "\n\t-oP file write PID to file"
217 "\n\t-t n n seconds timeout"
218 "\n\t-tfo enable TCP Fast Open"
223 while (na < argc && argv[na][0] == '-')
225 if (strcmp(argv[na], "-d") == 0) debug = 1;
226 else if (strcmp(argv[na], "-tfo") == 0) tfo = 1;
227 else if (strcmp(argv[na], "-t") == 0)
229 if (tmo_noerror = ((timeout = atoi(argv[++na])) < 0)) timeout = -timeout;
231 else if (strcmp(argv[na], "-i") == 0) initial_pause = atoi(argv[++na]);
232 else if (strcmp(argv[na], "-noipv4") == 0) use_ipv4 = 0;
233 else if (strcmp(argv[na], "-noipv6") == 0) use_ipv6 = 0;
234 else if (strcmp(argv[na], "-oP") == 0) pidfile = argv[++na];
237 printf("server: unknown option %s, try -h or --help\n", argv[na]);
243 if (!use_ipv4 && !use_ipv6)
245 printf("server: -noipv4 and -noipv6 cannot both be given\n");
251 printf("server: no port number or socket name given\n");
255 if (argv[na][0] == '/')
258 unlink(sockname); /* in case left lying around */
260 else port = atoi(argv[na]);
263 if (na < argc) connection_count = atoi(argv[na]);
266 /* Initial pause (before creating listen sockets */
267 if (initial_pause > 0)
270 printf("%ld: Inital pause of %d seconds\n", (long)time(NULL), initial_pause);
272 printf("Inital pause of %d seconds\n", initial_pause);
273 while (initial_pause > 0)
274 initial_pause = sleep(initial_pause);
279 if (port == 0) /* Unix domain */
281 if (debug) printf("%d: Creating Unix domain socket\n", time(NULL));
282 listen_socket[udn] = socket(PF_UNIX, SOCK_STREAM, 0);
283 if (listen_socket[udn] < 0)
285 printf("Unix domain socket creation failed: %s\n", strerror(errno));
294 if (debug) printf("Creating IPv6 socket\n");
295 listen_socket[v6n] = socket(AF_INET6, SOCK_STREAM, 0);
296 if (listen_socket[v6n] < 0)
298 printf("IPv6 socket creation failed: %s\n", strerror(errno));
301 #if defined(TCP_FASTOPEN) && !defined(__APPLE__)
305 if (setsockopt(listen_socket[v6n], IPPROTO_TCP, TCP_FASTOPEN,
306 &backlog, sizeof(backlog)))
307 if (debug) printf("setsockopt TCP_FASTOPEN: %s\n", strerror(errno));
310 /* If this is an IPv6 wildcard socket, set IPV6_V6ONLY if that option is
314 if (setsockopt(listen_socket[v6n], IPPROTO_IPV6, IPV6_V6ONLY, (char *)(&on),
316 printf("Setting IPV6_V6ONLY on IPv6 wildcard "
317 "socket failed (%s): carrying on without it\n", strerror(errno));
318 #endif /* IPV6_V6ONLY */
320 #endif /* HAVE_IPV6 */
322 /* Create an IPv4 socket if required */
326 if (debug) printf("Creating IPv4 socket\n");
327 listen_socket[v4n] = socket(AF_INET, SOCK_STREAM, 0);
328 if (listen_socket[v4n] < 0)
330 printf("IPv4 socket creation failed: %s\n", strerror(errno));
333 #if defined(TCP_FASTOPEN) && !defined(__APPLE__)
337 if (setsockopt(listen_socket[v4n], IPPROTO_TCP, TCP_FASTOPEN,
338 &backlog, sizeof(backlog)))
339 if (debug) printf("setsockopt TCP_FASTOPEN: %s\n", strerror(errno));
346 /* Set SO_REUSEADDR on the IP sockets so that the program can be restarted
347 while a connection is being handled - this can happen as old connections lie
348 around for a bit while crashed processes are tidied away. Without this, a
349 connection will prevent reuse of the smtp port for listening. */
351 for (i = v6n; i <= v4n; i++)
353 if (listen_socket[i] >= 0 &&
354 setsockopt(listen_socket[i], SOL_SOCKET, SO_REUSEADDR, (char *)(&on),
357 printf("setting SO_REUSEADDR on socket failed: %s\n", strerror(errno));
363 /* Now bind the sockets to the required port or path. If a path, ensure
364 anyone can write to it. */
369 sockun.sun_family = AF_UNIX;
370 if (debug) printf("Binding Unix domain socket\n");
371 sprintf(sockun.sun_path, "%.*s", (int)(sizeof(sockun.sun_path)-1), sockname);
372 if (bind(listen_socket[udn], (struct sockaddr *)&sockun, sizeof(sockun)) < 0)
374 printf("Unix domain socket bind() failed: %s\n", strerror(errno));
377 (void)stat(sockname, &statbuf);
378 if (debug) printf("Setting Unix domain socket mode: %0x\n",
379 statbuf.st_mode | 0777);
380 if (chmod(sockname, statbuf.st_mode | 0777) < 0)
382 printf("Unix domain socket chmod() failed: %s\n", strerror(errno));
389 for (i = 0; i < skn; i++)
391 if (listen_socket[i] < 0) continue;
393 /* For an IPv6 listen, use an IPv6 socket */
398 memset(&sin6, 0, sizeof(sin6));
399 sin6.sin6_family = AF_INET6;
400 sin6.sin6_port = htons(port);
401 sin6.sin6_addr = anyaddr6;
402 if (bind(listen_socket[i], (struct sockaddr *)&sin6, sizeof(sin6)) < 0)
404 printf("IPv6 socket bind(port %d) failed: %s\n", port, strerror(errno));
411 /* For an IPv4 bind, use an IPv4 socket, even in an IPv6 world. If an IPv4
412 bind fails EADDRINUSE after IPv6 success, carry on, because it means the
413 IPv6 socket will handle IPv4 connections. */
416 memset(&sin4, 0, sizeof(sin4));
417 sin4.sin_family = AF_INET;
418 sin4.sin_addr.s_addr = (S_ADDR_TYPE)INADDR_ANY;
419 sin4.sin_port = htons(port);
420 if (bind(listen_socket[i], (struct sockaddr *)&sin4, sizeof(sin4)) < 0)
421 if (listen_socket[v6n] < 0 || errno != EADDRINUSE)
423 printf("IPv4 socket bind(port %d) failed: %s\n", port, strerror(errno));
428 close(listen_socket[i]);
429 listen_socket[i] = -1;
436 /* Start listening. If IPv4 fails EADDRINUSE after IPv6 succeeds, ignore the
437 error because it means that the IPv6 socket will handle IPv4 connections. Don't
438 output anything, because it will mess up the test output, which will be
439 different for systems that do this and those that don't. */
441 for (i = 0; i <= skn; i++) if (listen_socket[i] >= 0)
443 if (listen(listen_socket[i], 5) < 0)
444 if (i != v4n || listen_socket[v6n] < 0 || errno != EADDRINUSE)
446 printf("listen() failed: %s\n", strerror(errno));
450 #if defined(TCP_FASTOPEN) && defined(__APPLE__)
452 && setsockopt(listen_socket[v4n], IPPROTO_TCP, TCP_FASTOPEN, &on, sizeof(on))
454 printf("setsockopt TCP_FASTOPEN: %s\n", strerror(errno));
462 if (!(p = fopen(pidfile, "w")))
464 fprintf(stderr, "pidfile create failed: %s\n", strerror(errno));
467 fprintf(p, "%ld\n", (long)getpid());
471 /* This program handles only a fixed number of connections, in sequence. Before
472 waiting for the first connection, read the standard input, which contains the
473 script of things to do. A line containing "++++" is treated as end of file.
474 This is so that the Perl driving script doesn't have to close the pipe -
475 because that would cause it to wait for this process, which it doesn't yet want
476 to do. The driving script adds the "++++" automatically - it doesn't actually
477 appear in the test script. Within lines we interpret \xNN and \\ groups */
479 while (fgets(CS buffer, sizeof(buffer), stdin) != NULL)
483 int n = (int)strlen(CS buffer);
485 if (n > 1 && buffer[0] == '>' && buffer[1] == '>')
487 while (n > 0 && isspace(buffer[n-1])) n--;
489 if (strcmp(CS buffer, "++++") == 0) break;
490 next = malloc(sizeof(line) + n);
494 char * s = CS buffer;
499 if (cl == '\\' && (cl = *++s) == 'x')
501 if ((ch = *++s - '0') > 9 && (ch -= 'A'-'9'-1) > 15) ch -= 'a'-'A';
502 if ((cl = *++s - '0') > 9 && (cl -= 'A'-'9'-1) > 15) cl -= 'a'-'A';
509 next->len = d - next->line - 1;
510 if (last == NULL) script = last = next;
511 else last->next = next;
517 /* SIGALRM handler crashes out */
519 signal(SIGALRM, sigalrm_handler);
521 /* s points to the current place in the script */
525 for (count = 0; count < connection_count; count++)
530 } content_length = { 0, FALSE };
535 printf("Listening on %s ... ", sockname);
537 accept_socket = accept(listen_socket[udn],
538 (struct sockaddr *)&sockun_accepted, &sockun_len);
545 fd_set select_listen;
547 printf("Listening on port %d ... ", port);
550 FD_ZERO(&select_listen);
551 for (i = 0; i < skn; i++)
553 if (listen_socket[i] >= 0) FD_SET(listen_socket[i], &select_listen);
554 if (listen_socket[i] > max_socket) max_socket = listen_socket[i];
557 if ((lcount = select(max_socket + 1, &select_listen, NULL, NULL, NULL)) < 0)
559 printf("Select failed\n");
565 for (i = 0; i < skn; i++)
566 if (listen_socket[i] > 0 && FD_ISSET(listen_socket[i], &select_listen))
568 accept_socket = accept(listen_socket[i],
569 (struct sockaddr *)&accepted, &len);
570 FD_CLR(listen_socket[i], &select_listen);
576 if (accept_socket < 0)
578 printf("accept() failed: %s\n", strerror(errno));
582 out = fdopen(accept_socket, "w");
584 dup_accept_socket = dup(accept_socket);
587 printf("\nConnection request from [%s]\n", host_ntoa(&accepted, CS buffer));
590 printf("\nConnection request\n");
592 /* Linux supports a feature for acquiring the peer's credentials, but it
593 appears to be Linux-specific. This code is untested and unused, just
594 saved here for reference. */
596 /**********--------------------
600 if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &cl)==0) {
601 printf("Peer's pid=%d, uid=%d, gid=%d\n",
602 cr.pid, cr.uid, cr.gid);
603 --------------*****************/
607 if (dup_accept_socket < 0)
609 printf("Couldn't dup socket descriptor\n");
610 printf("421 Connection refused: %s\n", strerror(errno));
611 fprintf(out, "421 Connection refused: %s\r\n", strerror(errno));
616 in = fdopen(dup_accept_socket, "r");
618 /* Loop for handling the conversation(s). For use in SMTP sessions, there are
619 default rules for determining input and output lines: the latter start with
620 digits. This means that the input looks like SMTP dialog. However, this
621 doesn't work for other tests (e.g. ident tests) so we have explicit '<' and
622 '>' flags for input and output as well as the defaults. */
624 for (; s; s = s->next)
628 /* Output lines either start with '>' or a digit. In the '>' case we can
629 fudge the sending of \r\n as required. Default is \r\n, ">>" send nothing,
630 ">CR>" sends \r only, and ">LF>" sends \n only. We can also force a
631 connection closedown by ">*eof". */
636 unsigned len = s->len;
637 printit(ss++, len--);
639 if (strncmp(ss, "*eof", 4) == 0)
646 { end = ""; ss++; len--; }
647 else if (strncmp(ss, "CR>", 3) == 0)
648 { end = "\r"; ss += 3; len -= 3; }
649 else if (strncmp(ss, "LF>", 3) == 0)
650 { end = "\n"; ss += 3; len -= 3; }
652 fwrite(ss, 1, len, out);
653 if (*end) fprintf(out, end);
656 else if (isdigit((unsigned char)ss[0]))
659 fprintf(out, "%s\r\n", ss);
662 /* If the script line starts with "*sleep" we just sleep for a while
663 before continuing. */
665 else if (strncmp(ss, "*sleep ", 7) == 0)
667 int sleepfor = atoi(ss+7);
673 /* If the script line starts with "*data " we expect a numeric argument,
674 and we expect to read (and discard) that many data bytes from the input. */
676 else if (strncmp(ss, "*data ", 6) == 0)
678 int dlen = atoi(ss+6);
686 n = dlen < sizeof(buffer) ? dlen : sizeof(buffer);
687 if ((n = read(dup_accept_socket, CS buffer, n)) == 0)
689 printf("Unexpected EOF read from client\n");
697 if (fgetc(in) == EOF)
699 printf("Unexpected EOF read from client\n");
705 /* Otherwise the script line is the start of an input line we are expecting
706 from the client, or "*eof" indicating we expect the client to close the
707 connection. Read command line or data lines; the latter are indicated
708 by the expected line being just ".". If the line starts with '<', that
709 doesn't form part of the expected input. (This allows for incoming data
710 starting with a digit.) If the line starts with '<<' we operate in
711 unbuffered rather than line mode and assume that a single read gets the
717 int data = strcmp(ss, ".") == 0;
741 n = read(dup_accept_socket, CS buffer+offset, s->len - offset);
742 if (content_length.in_use) content_length.left -= n;
745 printf("%sxpected EOF read from client\n",
746 (strncmp(ss, "*eof", 4) == 0)? "E" : "Une");
751 while (read(dup_accept_socket, &c, 1) == 1 && c != '\n') ;
755 printit(CS buffer, n);
759 n = (read(dup_accept_socket, &c, 1) == 1 && c == '.');
760 if (content_length.in_use) content_length.left--;
761 while (c != '\n' && read(dup_accept_socket, &c, 1) == 1)
762 if (content_length.in_use) content_length.left--;
764 else if (memcmp(ss, buffer, n) != 0)
766 printf("Comparison failed - bailing out\nExpected: ");
777 if (fgets(CS buffer+offset, sizeof(buffer)-offset, in) == NULL)
779 printf("%sxpected EOF read from client\n",
780 (strncmp(ss, "*eof", 4) == 0)? "E" : "Une");
785 n = strlen(CS buffer);
786 if (content_length.in_use) content_length.left -= (n - offset);
787 while (n > 0 && isspace(buffer[n-1])) n--;
789 printf("%s\n", buffer);
790 if (!data || strcmp(CS buffer, ".") == 0) break;
793 if (strncmp(ss, CS buffer, (int)strlen(ss)) != 0)
795 printf("Comparison failed - bailing out\n");
796 printf("Expected: %s\n", ss);
801 if (sscanf(CCS buffer, "<Content-length: %d", &content_length.left))
802 content_length.in_use = TRUE;
803 if (content_length.in_use && content_length.left <= 0)
804 shutdown(dup_accept_socket, SHUT_RD);
813 if (s == NULL) printf("End of script\n");
815 if (sockname) unlink(sockname);
819 /* End of server.c */