5 * (c) 2012 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of Yet Another Ident Daemon (YAID).
12 * YAID is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * YAID is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with YAID; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 /*----- Header files ------------------------------------------------------*/
31 /*----- Data structures ---------------------------------------------------*/
33 /* A write buffer is the gadget which keeps track of our output and writes
34 * portions of it out as and when connections are ready for it.
38 size_t o; /* Offset of remaining data */
39 size_t n; /* Length of remaining data */
40 sel_file wr; /* Write selector */
41 void (*func)(int /*err*/, void *); /* Function to call on completion */
42 void *p; /* Context for `func' */
43 unsigned char buf[WRBUFSZ]; /* Output buffer */
46 /* Structure for a listening socket. There's one of these for each address
47 * family we're looking after.
50 const struct addrops *ao; /* Address family operations */
51 sel_file f; /* Watch for incoming connections */
54 /* The main structure for a client. */
56 int fd; /* The connection to the client */
57 selbuf b; /* Accumulate lines of input */
58 union addr raddr; /* Remote address */
59 struct query q; /* The clients query and our reply */
60 struct sel_timer t; /* Timeout for idle or doomed conn */
61 struct listen *l; /* Back to the listener (and ops) */
62 struct writebuf wb; /* Write buffer for our reply */
63 struct proxy *px; /* Proxy if conn goes via NAT */
64 struct client *next; /* Next in a chain of clients */
67 /* A proxy connection. */
69 int fd; /* Connection; -1 if in progress */
70 struct client *c; /* Back to the client */
71 conn cn; /* Nonblocking connection */
72 selbuf b; /* Accumulate the response line */
73 struct writebuf wb; /* Write buffer for query */
74 char nat[ADDRLEN]; /* Server address, as text */
75 struct proxy *next; /* Next in a chain of proxies */
78 /*----- Static variables --------------------------------------------------*/
80 static sel_state sel; /* I/O multiplexer state */
82 static const char *pidfile = 0; /* Where to write daemon's pid */
84 static const char *policyfile = POLICYFILE; /* Filename for global policy */
85 static const struct policy default_policy = POLICY_INIT(A_NAME);
86 static policy_v policy = DA_INIT; /* Vector of global policy rules */
87 static fwatch polfw; /* Watch policy file for changes */
89 static unsigned char tokenbuf[4096]; /* Random-ish data for tokens */
90 static size_t tokenptr = sizeof(tokenbuf); /* Current read position */
91 static int randfd; /* File descriptor for random data */
93 static struct client *dead_clients = 0; /* List of defunct clients */
94 static struct proxy *dead_proxies = 0; /* List of defunct proxies */
96 static unsigned flags = 0; /* Various interesting flags */
97 #define F_SYSLOG 1u /* Use syslog for logging */
98 #define F_RUNNING 2u /* Running properly now */
100 /*----- Ident protocol parsing --------------------------------------------*/
102 /* Advance *PP over whitespace characters. */
103 static void skipws(const char **pp)
104 { while (isspace((unsigned char )**pp)) (*pp)++; }
106 /* Copy a token of no more than N bytes starting at *PP into Q, advancing *PP
109 static int idtoken(const char **pp, char *q, size_t n)
116 if (*p == ':' || *p <= 32 || *p >= 127) break;
126 /* Read an unsigned decimal number from *PP, and store it in *II. Check that
127 * it's between MIN and MAX, and advance *PP over it. Return zero for
128 * success, or nonzero if something goes wrong.
130 static int unum(const char **pp, unsigned *ii, unsigned min, unsigned max)
137 if (!isdigit((unsigned char)**pp)) return (-1);
138 e = errno; errno = 0;
139 i = strtoul(*pp, &q, 10);
140 if (errno) return (-1);
143 if (i < min || i > max) return (-1);
148 /*----- Asynchronous writing ----------------------------------------------*/
150 /* Callback for actually writing stuff from a `writebuf'. */
151 static void write_out(int fd, unsigned mode, void *p)
154 struct writebuf *wb = p;
156 /* Try to write something. */
157 if ((n = write(fd, wb->buf + wb->o, wb->n)) < 0) {
158 if (errno == EAGAIN || errno == EWOULDBLOCK) return;
161 wb->func(errno, wb->p);
166 /* If there's nothing left then restore the buffer to its empty state. */
174 /* Queue N bytes starting at P to be written. */
175 static int queue_write(struct writebuf *wb, const void *p, size_t n)
177 /* Maybe there's nothing to actually do. */
180 /* Make sure it'll fit. */
181 if (wb->n - wb->o + n > WRBUFSZ) return (-1);
183 /* If there's anything there already, then make sure it's at the start of
184 * the available space.
187 memmove(wb->buf, wb->buf + wb->o, wb->n);
191 /* If there's nothing currently there, then we're not requesting write
192 * notifications, so set that up, and force an initial wake-up.
195 sel_addfile(&wb->wr);
199 /* Copy the new material over. */
200 memcpy(wb->buf + wb->n, p, n);
207 /* Release resources allocated to WB. */
208 static void free_writebuf(struct writebuf *wb)
209 { if (wb->n) sel_rmfile(&wb->wr); }
211 /* Initialize a writebuf in *WB, writing to file descriptor FD. On
212 * completion, call FUNC, passing it P and an error indicator: either 0 for
213 * success or an `errno' value on failure.
215 static void init_writebuf(struct writebuf *wb,
216 int fd, void (*func)(int, void *), void *p)
218 sel_initfile(&sel, &wb->wr, fd, SEL_WRITE, write_out, wb);
224 /*----- General utilities -------------------------------------------------*/
226 /* Format and log MSG somewhere sensible, at the syslog(3) priority PRIO.
227 * Prefix it with a description of the query Q, if non-null.
229 void logmsg(const struct query *q, int prio, const char *msg, ...)
239 dputsock(&d, q->ao, &q->s[L]);
240 dstr_puts(&d, " <-> ");
241 dputsock(&d, q->ao, &q->s[R]);
244 dstr_vputf(&d, msg, &ap);
247 if (!(flags & F_RUNNING))
249 else if (flags & F_SYSLOG)
250 syslog(prio, "%s", d.buf);
254 strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S %z", tm);
255 fprintf(stderr, "%s %s: %s\n", buf, QUIS, d.buf);
261 /* Fix up a socket FD so that it won't bite us. Returns zero on success, or
264 static int fix_up_socket(int fd, const char *what)
268 if (fdflags(fd, O_NONBLOCK, O_NONBLOCK, 0, 0)) {
269 logmsg(0, LOG_ERR, "failed to set %s connection nonblocking: %s",
270 what, strerror(errno));
274 if (setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &yes, sizeof(yes))) {
276 "failed to disable `out-of-band' data on %s connection: %s",
277 what, strerror(errno));
284 /*----- Client output functions -------------------------------------------*/
286 static void disconnect_client(struct client *c);
288 /* Notification that output has been written. If successful, re-enable the
289 * input buffer and prepare for another query.
291 static void done_client_write(int err, void *p)
293 struct client *c = p;
296 selbuf_enable(&c->b);
298 logmsg(&c->q, LOG_ERR, "failed to send reply: %s", strerror(err));
299 disconnect_client(c);
303 /* Format the message FMT and queue it to be sent to the client. Client
304 * input will be disabled until the write completes.
306 static void PRINTF_LIKE(2, 3)
307 write_to_client(struct client *c, const char *fmt, ...)
314 n = vsnprintf(buf, sizeof(buf), fmt, ap);
316 logmsg(&c->q, LOG_ERR, "failed to format output: %s", strerror(errno));
317 disconnect_client(c);
319 } else if (n > sizeof(buf)) {
320 logmsg(&c->q, LOG_ERR, "output too long for client send buffer");
321 disconnect_client(c);
325 selbuf_disable(&c->b);
326 if (queue_write(&c->wb, buf, n)) {
327 logmsg(&c->q, LOG_ERR, "write buffer overflow");
328 disconnect_client(c);
332 /* Format a reply to the client, with the form LPORT:RPORT:TY:TOK0[:TOK1].
333 * Typically, TY will be `ERROR' or `USERID'. In the former case, TOK0 will
334 * be the error token and TOK1 will be null; in the latter case, TOK0 will be
335 * the operating system and TOK1 the user name.
337 static void reply(struct client *c, const char *ty,
338 const char *tok0, const char *tok1)
340 write_to_client(c, "%u,%u:%s:%s%s%s\r\n",
341 c->q.s[L].port, c->q.s[R].port, ty,
342 tok0, tok1 ? ":" : "", tok1 ? tok1 : "");
345 /* Mapping from error codes to their protocol tokens. */
346 const char *const errtok[] = {
347 #define DEFTOK(err, tok) tok,
352 /* Report an error with code ERR to the client. */
353 static void reply_error(struct client *c, unsigned err)
355 assert(err < E_LIMIT);
356 reply(c, "ERROR", errtok[err], 0);
359 /*----- NAT proxy functions -----------------------------------------------*/
361 /* Cancel the proxy operation PX, closing the connection and releasing
362 * resources. This is used for both normal and unexpected closures.
364 static void cancel_proxy(struct proxy *px)
370 selbuf_disable(&px->b);
373 selbuf_enable(&px->c->b);
374 px->next = dead_proxies;
378 /* Delayed destruction of unsafe parts of proxies. */
379 static void reap_dead_proxies(void)
381 struct proxy *px, *pp;
383 for (px = dead_proxies; px; px = pp) {
386 selbuf_destroy(&px->b);
387 free_writebuf(&px->wb);
394 /* Notification that a line (presumably a reply) has been received from the
395 * server. We should check it, log it, and propagate the answer back.
396 * Whatever happens, this proxy operation is now complete.
398 static void proxy_line(char *line, size_t sz, void *p)
400 struct proxy *px = p;
402 const char *q = line;
405 /* Trim trailing space. */
406 while (sz && isspace((unsigned char)line[sz - 1])) sz--;
408 /* Parse the port numbers. These should match the request. */
409 if (unum(&q, &lp, 1, 65535)) goto syntax;
410 skipws(&q); if (*q != ',') goto syntax; q++;
411 if (unum(&q, &rp, 1, 65535)) goto syntax;
412 skipws(&q); if (*q != ':') goto syntax; q++;
413 if (lp != px->c->q.u.nat.port || rp != px->c->q.s[R].port) goto syntax;
415 /* Find out what kind of reply this is. */
416 if (idtoken(&q, buf, sizeof(buf))) goto syntax;
417 skipws(&q); if (*q != ':') goto syntax; q++;
419 if (strcmp(buf, "ERROR") == 0) {
421 /* Report the error without interpreting it. It might be meaningful to
425 logmsg(&px->c->q, LOG_ERR, "proxy error from %s: %s", px->nat, q);
426 reply(px->c, "ERROR", q, 0);
428 } else if (strcmp(buf, "USERID") == 0) {
430 /* Parse out the operating system and user name, and pass them on. */
431 if (idtoken(&q, buf, sizeof(buf))) goto syntax;
432 skipws(&q); if (*q != ':') goto syntax; q++;
434 logmsg(&px->c->q, LOG_ERR, "user `%s'; proxy = %s, os = %s",
436 reply(px->c, "USERID", buf, q);
443 /* We didn't understand the message from the client. */
444 logmsg(&px->c->q, LOG_ERR, "failed to parse response from %s", px->nat);
445 reply_error(px->c, E_UNKNOWN);
447 /* All finished, no matter what. */
451 /* Notification that we have written the query to the server. Await a
452 * response if successful.
454 static void done_proxy_write(int err, void *p)
456 struct proxy *px = p;
459 logmsg(&px->c->q, LOG_ERR, "failed to proxy query to %s: %s",
460 px->nat, strerror(errno));
461 reply_error(px->c, E_UNKNOWN);
465 selbuf_enable(&px->b);
468 /* Notification that the connection to the server is either established or
469 * failed. In the former case, queue the right query.
471 static void proxy_connected(int fd, void *p)
473 struct proxy *px = p;
477 /* If the connection failed then report the problem and give up. */
479 logmsg(&px->c->q, LOG_ERR,
480 "failed to make %s proxy connection to %s: %s",
481 px->c->l->ao->name, px->nat, strerror(errno));
482 reply_error(px->c, E_UNKNOWN);
487 /* We're now ready to go, so set things up. */
489 selbuf_init(&px->b, &sel, fd, proxy_line, px);
490 selbuf_setsize(&px->b, 1024);
491 selbuf_disable(&px->b);
492 init_writebuf(&px->wb, fd, done_proxy_write, px);
494 /* Write the query. This buffer is large enough because we've already
495 * range-checked the remote the port number and the local one came from the
496 * kernel, which we trust not to do anything stupid.
498 n = sprintf(buf, "%u,%u\r\n", px->c->q.u.nat.port, px->c->q.s[R].port);
499 queue_write(&px->wb, buf, n);
502 /* Proxy the query through to a client machine for which we're providing NAT
505 static void proxy_query(struct client *c)
508 struct sockaddr_storage ss;
513 /* Allocate the context structure for the NAT. */
514 px = xmalloc(sizeof(*px));
516 /* We'll use the client host's address in lots of log messages, so we may
517 * as well format it once and use it over and over.
519 inet_ntop(c->q.ao->af, &c->q.u.nat.addr, px->nat, sizeof(px->nat));
521 /* Create the socket for the connection. */
522 if ((fd = socket(c->q.ao->af, SOCK_STREAM, 0)) < 0) {
523 logmsg(&c->q, LOG_ERR, "failed to make %s socket for proxy: %s",
524 c->l->ao->name, strerror(errno));
527 if (fix_up_socket(fd, "proxy")) goto err_1;
529 /* Set up the connection to the client host. The connection interface is a
530 * bit broken: if the connection completes immediately, then the callback
531 * function is called synchronously, and that might decide to shut
532 * everything down. So we must have fully initialized our context before
533 * calling `conn_init', and mustn't touch it again afterwards -- since the
534 * block may have been freed.
538 c->l->ao->socket_to_sockaddr(&s, &ss, &ssz);
539 selbuf_disable(&c->b);
540 c->px = px; px->c = c;
542 if (conn_init(&px->cn, &sel, fd, (struct sockaddr *)&ss, ssz,
543 proxy_connected, px)) {
544 logmsg(&c->q, LOG_ERR, "failed to make %s proxy connection to %s: %s",
545 c->l->ao->name, px->nat, strerror(errno));
549 /* All ready to go. */
552 /* Tidy up after various kinds of failures. */
554 selbuf_enable(&c->b);
559 reply_error(c, E_UNKNOWN);
562 /*----- Client connection functions ---------------------------------------*/
564 /* Disconnect a client, freeing up any associated resources. */
565 static void disconnect_client(struct client *c)
567 selbuf_disable(&c->b);
570 free_writebuf(&c->wb);
571 if (c->px) cancel_proxy(c->px);
572 c->next = dead_clients;
576 /* Throw away dead clients now that we've reached a safe point in the
579 static void reap_dead_clients(void)
581 struct client *c, *cc;
582 for (c = dead_clients; c; c = cc) {
584 selbuf_destroy(&c->b);
590 /* Time out a client because it's been idle for too long. */
591 static void timeout_client(struct timeval *tv, void *p)
593 struct client *c = p;
594 logmsg(&c->q, LOG_NOTICE, "timing out idle or stuck client");
595 sel_addtimer(&sel, &c->t, tv, timeout_client, 0);
596 disconnect_client(c);
599 /* Reset the client idle timer, as a result of activity. Set EXISTP if
600 * there is an existing timer which needs to be removed.
602 static void reset_client_timer(struct client *c, int existp)
606 gettimeofday(&tv, 0);
608 if (existp) sel_rmtimer(&c->t);
609 sel_addtimer(&sel, &c->t, &tv, timeout_client, c);
612 /* Write a pseudorandom token into the buffer at P, which must have space for
613 * at least TOKENSZ bytes.
615 #define TOKENRANDSZ 8
616 #define TOKENSZ ((4*TOKENRANDSZ + 5)/3)
617 static void user_token(char *p)
622 static const char tokmap[64] =
623 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789.-";
625 /* If there's not enough pseudorandom stuff lying around, then read more
628 if (tokenptr + TOKENRANDSZ >= sizeof(tokenbuf)) {
629 if (read(randfd, tokenbuf, sizeof(tokenbuf)) < sizeof(tokenbuf))
630 die(1, "unexpected short read or error from `/dev/urandom'");
634 /* Now encode the bytes using a slightly tweaked base-64 encoding. Read
635 * bytes into the accumulator and write out characters while there's
638 for (i = 0; i < TOKENRANDSZ; i++) {
639 a = (a << 8) | tokenbuf[tokenptr++]; b += 8;
642 *p++ = tokmap[(a >> b) & 0x3f];
646 /* If there's anything left in the accumulator then flush it out. */
648 *p++ = tokmap[(a << (6 - b)) & 0x3f];
650 /* Null-terminate the token. */
654 /* Notification that a line has been received from the client. Parse it,
655 * find out about the connection it's referring to, apply the relevant
656 * policy rules, and produce a response. This is where almost everything
657 * interesting happens.
659 static void client_line(char *line, size_t len, void *p)
661 struct client *c = p;
663 struct passwd *pw = 0;
664 const struct policy *pol;
666 struct policy upol = POLICY_INIT(A_LIMIT);
667 struct policy_file pf;
671 /* If the connection has closed, then tidy stuff away. */
672 c->q.s[R].addr = c->raddr;
673 c->q.s[L].port = c->q.s[R].port = 0;
675 disconnect_client(c);
679 /* Client activity, so update the timer. */
680 reset_client_timer(c, 1);
682 /* See if the policy file has changed since we last looked. If so, try to
683 * read the new version.
685 if (fwatch_update(&polfw, policyfile)) {
686 logmsg(0, LOG_INFO, "reload master policy file `%s'", policyfile);
687 load_policy_file(policyfile, &policy);
690 /* Read the local and remote port numbers into the query structure. */
692 if (unum(&q, &c->q.s[L].port, 1, 65535)) goto bad;
693 skipws(&q); if (*q != ',') goto bad; q++;
694 if (unum(&q, &c->q.s[R].port, 1, 65535)) goto bad;
695 skipws(&q); if (*q) goto bad;
697 /* Identify the connection. Act on the result. */
702 /* We found a user. Track down the user's password entry, because
703 * we'll want that later. Most of the processing for this case is
706 if ((pw = getpwuid(c->q.u.uid)) == 0) {
707 logmsg(&c->q, LOG_ERR, "no passwd entry for user %d", c->q.u.uid);
708 reply_error(c, E_NOUSER);
714 /* We've acted as a NAT for this connection. Proxy the query through
715 * to the actal client host.
721 /* We failed to identify the connection for some reason. We should
722 * already have logged an error, so there's not much to do here.
724 reply_error(c, c->q.u.error);
728 /* Something happened that we don't understand. */
732 /* Search the table of policy rules to find a match. */
733 for (i = 0; i < DA_LEN(&policy); i++) {
734 pol = &DA(&policy)[i];
735 if (!match_policy(pol, &c->q)) continue;
737 /* If this is something simple, then apply the resulting policy rule. */
738 if (pol->act.act != A_USER) goto match;
740 /* The global policy has decided to let the user have a say, so we must
741 * parse the user file.
744 dstr_putf(&d, "%s/.yaid.policy", pw->pw_dir);
745 if (open_policy_file(&pf, d.buf, "user policy file", &c->q, OPF_NOENTOK))
747 while ((t = read_policy_file(&pf)) < T_ERROR) {
749 /* Give up after 100 lines or if there's an error. If the user's
750 * policy is that complicated, something's gone very wrong. Or there's
751 * too much commentary or something.
754 logmsg(&c->q, LOG_ERR, "%s:%d: user policy file too long",
759 /* If this was a blank line, just go around again. */
760 if (t != T_OK) continue;
762 /* If this isn't a match, go around for the next rule. */
763 if (!match_policy(&pf.p, &c->q)) continue;
765 /* Check that the user is allowed to request this action. If not, see
766 * if there's a more acceptable action later on.
768 if (!(pol->act.u.user & (1 << pf.p.act.act))) {
769 logmsg(&c->q, LOG_ERR,
770 "%s:%d: user action forbidden by global policy",
775 /* We've found a match, so grab it, close the file, and say we're
778 upol = pf.p; pol = &upol;
780 close_policy_file(&pf);
784 close_policy_file(&pf);
788 /* No match: apply the built-in default policy. */
789 pol = &default_policy;
792 switch (pol->act.act) {
795 /* Report the actual user's name. */
796 logmsg(&c->q, LOG_INFO, "user `%s' (%d)", pw->pw_name, c->q.u.uid);
797 reply(c, "USERID", "UNIX", pw->pw_name);
801 /* Report an arbitrary token which we can look up in our log file. */
803 logmsg(&c->q, LOG_INFO, "user `%s' (%d); token = %s",
804 pw->pw_name, c->q.u.uid, buf);
805 reply(c, "USERID", "OTHER", buf);
809 /* Deny that there's anyone there at all. */
810 logmsg(&c->q, LOG_INFO, "user `%s' (%d); denying",
811 pw->pw_name, c->q.u.uid);
815 /* Report the user as being hidden. */
816 logmsg(&c->q, LOG_INFO, "user `%s' (%d); hiding",
817 pw->pw_name, c->q.u.uid);
818 reply_error(c, E_HIDDEN);
822 /* Tell an egregious lie about who the user is. */
823 logmsg(&c->q, LOG_INFO, "user `%s' (%d); lie = `%s'",
824 pw->pw_name, c->q.u.uid, pol->act.u.lie);
825 reply(c, "USERID", "UNIX", pol->act.u.lie);
829 /* Something has gone very wrong. */
838 logmsg(&c->q, LOG_ERR, "failed to parse query from client");
839 disconnect_client(c);
842 /* Notification that a new client has connected. Prepare to read a query. */
843 static void accept_client(int fd, unsigned mode, void *p)
845 struct listen *l = p;
847 struct sockaddr_storage ssr, ssl;
848 size_t ssz = sizeof(ssr);
851 /* Accept the new connection. */
852 if ((sk = accept(fd, (struct sockaddr *)&ssr, &ssz)) < 0) {
853 if (errno != EAGAIN && errno == EWOULDBLOCK) {
854 logmsg(0, LOG_ERR, "failed to accept incoming %s connection: %s",
855 l->ao->name, strerror(errno));
859 if (fix_up_socket(sk, "incoming client")) { close(sk); return; }
861 /* Build a client block and fill it in. */
862 c = xmalloc(sizeof(*c));
866 /* Collect the local and remote addresses. */
867 l->ao->sockaddr_to_addr(&ssr, &c->raddr);
869 if (getsockname(sk, (struct sockaddr *)&ssl, &ssz)) {
871 "failed to read local address for incoming %s connection: %s",
872 l->ao->name, strerror(errno));
877 l->ao->sockaddr_to_addr(&ssl, &c->q.s[L].addr);
878 c->q.s[L].port = c->q.s[R].port = 0;
880 /* Set stuff up for reading the query and sending responses. */
881 selbuf_init(&c->b, &sel, sk, client_line, c);
882 selbuf_setsize(&c->b, 1024);
883 reset_client_timer(c, 0);
886 init_writebuf(&c->wb, sk, done_client_write, c);
889 /*----- Main code ---------------------------------------------------------*/
891 /* Set up a listening socket for the address family described by AO,
894 static int make_listening_socket(const struct addrops *ao, int port)
899 struct sockaddr_storage ss;
903 /* Make the socket. */
904 if ((fd = socket(ao->af, SOCK_STREAM, 0)) < 0) {
905 if (errno == EAFNOSUPPORT) return (-1);
906 die(1, "failed to create %s listening socket: %s",
907 ao->name, strerror(errno));
910 /* Build the appropriate local address. */
913 ao->socket_to_sockaddr(&s, &ss, &ssz);
915 /* Perform any initialization specific to the address type. */
916 if (ao->init_listen_socket(fd)) {
917 die(1, "failed to initialize %s listening socket: %s",
918 ao->name, strerror(errno));
921 /* Bind to the address. */
922 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
923 if (bind(fd, (struct sockaddr *)&ss, ssz)) {
924 die(1, "failed to bind %s listening socket: %s",
925 ao->name, strerror(errno));
928 /* Avoid unpleasant race conditions. */
929 if (fdflags(fd, O_NONBLOCK, O_NONBLOCK, 0, 0)) {
930 die(1, "failed to set %s listening socket nonblocking: %s",
931 ao->name, strerror(errno));
934 /* Prepare to listen. */
936 die(1, "failed to listen for %s: %s", ao->name, strerror(errno));
938 /* Make a record of all of this. */
939 l = xmalloc(sizeof(*l));
941 sel_initfile(&sel, &l->f, fd, SEL_READ, accept_client, l);
948 /* Quit because of a fatal signal. */
949 static void NORETURN quit(int sig, void *p)
951 const char *signame = p;
953 logmsg(0, LOG_NOTICE, "shutting down on %s", signame);
954 if (pidfile) unlink(pidfile);
958 /* Answer whether the string pointed to by P consists entirely of digits. */
959 static int numericp(const char *p)
962 if (!isdigit((unsigned char)*p++)) return (0);
966 static void usage(FILE *fp)
968 pquis(fp, "Usage: $ [-Dl] [-G GROUP] [-U USER] [-P FILE] "
969 "[-c FILE] [-p PORT]\n");
972 static void version(FILE *fp)
973 { pquis(fp, "$, version " VERSION "\n"); }
975 static void help(FILE *fp)
977 version(fp); fputc('\n', fp);
980 Yet Another Ident Daemon. Really, the world doesn't need such a thing.\n\
981 It's just a shame none of the others do the right things.\n\
985 -h, --help Show this help message.\n\
986 -v, --version Show the version number.\n\
987 -u, --usage Show a very short usage summary.\n\
989 -D, --daemon Become a daemon, running in the background.\n\
990 -G, --group=GROUP Set group after initialization.\n\
991 -P, --pidfile=FILE Write process id to FILE.\n\
992 -U, --user=USER Set user after initialization.\n\
993 -c, --config=FILE Read global policy from FILE.\n\
994 -l, --syslog Write log messages using syslog(3).\n\
995 -p, --port=PORT Listen for connections on this port.\n",
999 int main(int argc, char *argv[])
1004 struct passwd *pw = 0;
1007 sig sigint, sigterm;
1013 const struct addrops *ao;
1018 /* Parse command-line options. */
1020 const struct option opts[] = {
1021 { "help", 0, 0, 'h' },
1022 { "version", 0, 0, 'v' },
1023 { "usage", 0, 0, 'u' },
1024 { "daemon", 0, 0, 'D' },
1025 { "group", OPTF_ARGREQ, 0, 'G' },
1026 { "pidfile", OPTF_ARGREQ, 0, 'P' },
1027 { "user", OPTF_ARGREQ, 0, 'U' },
1028 { "config", OPTF_ARGREQ, 0, 'c' },
1029 { "syslog", 0, 0, 'l' },
1030 { "port", OPTF_ARGREQ, 0, 'p' },
1034 if ((i = mdwopt(argc, argv, "hvuDG:P:U:c:lp:", opts, 0, 0, 0)) < 0)
1037 case 'h': help(stdout); exit(0);
1038 case 'v': version(stdout); exit(0);
1039 case 'u': usage(stdout); exit(0);
1040 case 'D': f |= f_daemon; break;
1041 case 'P': pidfile = optarg; break;
1042 case 'c': policyfile = optarg; break;
1043 case 'l': flags |= F_SYSLOG; break;
1045 if (numericp(optarg))
1047 else if ((gr = getgrnam(optarg)) == 0)
1048 die(1, "unknown group `%s'", optarg);
1053 if (numericp(optarg))
1055 else if ((pw = getpwnam(optarg)) == 0)
1056 die(1, "unknown user `%s'", optarg);
1061 if (numericp(optarg))
1062 port = atoi(optarg);
1063 else if ((s = getservbyname(optarg, "tcp")) == 0)
1064 die(1, "unknown service name `%s'", optarg);
1066 port = ntohs(s->s_port);
1068 default: f |= f_bogus; break;
1071 if (optind < argc) f |= f_bogus;
1072 if (f & f_bogus) { usage(stderr); exit(1); }
1074 /* If a user has been requested, but no group, then find the user's primary
1075 * group. If the user was given by name, then we already have a password
1076 * entry and should use that, in case two differently-named users have the
1077 * same uid but distinct gids.
1079 if (u != -1 && g == -1) {
1080 if (!pw && (pw = getpwuid(u)) == 0) {
1081 die(1, "failed to find password entry for user %d: "
1082 "request group explicitly", u);
1087 /* Initialize system-specific machinery. */
1090 /* Load the global policy rules. */
1091 fwatch_init(&polfw, policyfile);
1092 if (load_policy_file(policyfile, &policy))
1095 /* Open the random data source. */
1096 if ((randfd = open("/dev/urandom", O_RDONLY)) < 0) {
1097 die(1, "failed to open `/dev/urandom' for reading: %s",
1101 /* Set up the I/O event system. */
1104 /* Watch for some interesting signals. */
1106 sig_add(&sigint, SIGINT, quit, "SIGINT");
1107 sig_add(&sigterm, SIGTERM, quit, "SIGTERM");
1109 /* Listen for incoming connections. */
1110 for (ao = addroptab; ao->name; ao++)
1111 if (!make_listening_socket(ao, port)) any = 1;
1112 if (!any) die(1, "no IP protocols supported");
1114 /* Open the pidfile now, in case it's somewhere we can't write. */
1115 if (pidfile && (fp = fopen(pidfile, "w")) == 0) {
1116 die(1, "failed to open pidfile `%s' for writing: %s",
1117 pidfile, strerror(errno));
1120 /* If we're meant to use syslog, then open the log. */
1121 if (flags & F_SYSLOG)
1122 openlog(QUIS, 0, LOG_DAEMON);
1124 /* Drop privileges. */
1125 if ((g != -1 && (setegid(g) || setgid(g) ||
1126 (getuid() == 0 && setgroups(1, &g)))) ||
1127 (u != -1 && setuid(u)))
1128 die(1, "failed to drop privileges: %s", strerror(errno));
1130 /* Become a background process, if requested. */
1131 if ((f & f_daemon) && daemonize())
1132 die(1, "failed to become daemon: %s", strerror(errno));
1134 /* Write the process id to the pidfile. */
1136 fprintf(fp, "%d\n", getpid());
1140 /* And now we're going. */
1143 /* Read events and process them. */
1145 if (sel_select(&sel) && errno != EINTR)
1146 die(1, "select failed: %s", strerror(errno));
1147 reap_dead_proxies();
1148 reap_dead_clients();
1151 /* This just keeps the compiler happy. */
1155 /*----- That's all, folks -------------------------------------------------*/