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 */
92 static struct client
*dead_clients
= 0; /* List of defunct clients */
93 static struct proxy
*dead_proxies
= 0; /* List of defunct proxies */
95 static unsigned flags
= 0; /* Various interesting flags */
96 #define F_SYSLOG 1u /* Use syslog for logging */
97 #define F_RUNNING 2u /* Running properly now */
99 /*----- Ident protocol parsing --------------------------------------------*/
101 /* Advance *PP over whitespace characters. */
102 static void skipws(const char **pp
)
103 { while (isspace((unsigned char )**pp
)) (*pp
)++; }
105 /* Copy a token of no more than N bytes starting at *PP into Q, advancing *PP
108 static int idtoken(const char **pp
, char *q
, size_t n
)
115 if (*p
== ':' || *p
<= 32 || *p
>= 127) break;
125 /* Read an unsigned decimal number from *PP, and store it in *II. Check that
126 * it's between MIN and MAX, and advance *PP over it. Return zero for
127 * success, or nonzero if something goes wrong.
129 static int unum(const char **pp
, unsigned *ii
, unsigned min
, unsigned max
)
136 if (!isdigit((unsigned char)**pp
)) return (-1);
137 e
= errno
; errno
= 0;
138 i
= strtoul(*pp
, &q
, 10);
139 if (errno
) return (-1);
142 if (i
< min
|| i
> max
) return (-1);
147 /*----- Asynchronous writing ----------------------------------------------*/
149 /* Callback for actually writing stuff from a `writebuf'. */
150 static void write_out(int fd
, unsigned mode
, void *p
)
153 struct writebuf
*wb
= p
;
155 /* Try to write something. */
156 if ((n
= write(fd
, wb
->buf
+ wb
->o
, wb
->n
)) < 0) {
157 if (errno
== EAGAIN
|| errno
== EWOULDBLOCK
) return;
160 wb
->func(errno
, wb
->p
);
165 /* If there's nothing left then restore the buffer to its empty state. */
173 /* Queue N bytes starting at P to be written. */
174 static int queue_write(struct writebuf
*wb
, const void *p
, size_t n
)
176 /* Maybe there's nothing to actually do. */
179 /* Make sure it'll fit. */
180 if (wb
->n
- wb
->o
+ n
> WRBUFSZ
) return (-1);
182 /* If there's anything there already, then make sure it's at the start of
183 * the available space.
186 memmove(wb
->buf
, wb
->buf
+ wb
->o
, wb
->n
);
190 /* If there's nothing currently there, then we're not requesting write
191 * notifications, so set that up, and force an initial wake-up.
194 sel_addfile(&wb
->wr
);
198 /* Copy the new material over. */
199 memcpy(wb
->buf
+ wb
->n
, p
, n
);
206 /* Release resources allocated to WB. */
207 static void free_writebuf(struct writebuf
*wb
)
208 { if (wb
->n
) sel_rmfile(&wb
->wr
); }
210 /* Initialize a writebuf in *WB, writing to file descriptor FD. On
211 * completion, call FUNC, passing it P and an error indicator: either 0 for
212 * success or an `errno' value on failure.
214 static void init_writebuf(struct writebuf
*wb
,
215 int fd
, void (*func
)(int, void *), void *p
)
217 sel_initfile(&sel
, &wb
->wr
, fd
, SEL_WRITE
, write_out
, wb
);
223 /*----- General utilities -------------------------------------------------*/
225 static void vlogmsg(const struct query
*q
, int prio
,
226 const char *msg
, va_list *ap
)
234 dputsock(&d
, q
->ao
, &q
->s
[L
]);
235 dstr_puts(&d
, " <-> ");
236 dputsock(&d
, q
->ao
, &q
->s
[R
]);
239 dstr_vputf(&d
, msg
, ap
);
241 if (!(flags
& F_RUNNING
))
243 else if (flags
& F_SYSLOG
)
244 syslog(prio
, "%s", d
.buf
);
248 strftime(buf
, sizeof(buf
), "%Y-%m-%d %H:%M:%S %z", tm
);
249 fprintf(stderr
, "%s %s: %s\n", buf
, QUIS
, d
.buf
);
255 /* Format and log MSG somewhere sensible, at the syslog(3) priority PRIO.
256 * Prefix it with a description of the query Q, if non-null.
258 void logmsg(const struct query
*q
, int prio
, const char *msg
, ...)
263 vlogmsg(q
, prio
, msg
, &ap
);
267 /* Format and report MSG as a fatal error, and exit. */
268 void fatal(const char *msg
, ...)
273 vlogmsg(0, LOG_CRIT
, msg
, &ap
);
278 /* Fix up a socket FD so that it won't bite us. Returns zero on success, or
281 static int fix_up_socket(int fd
, const char *what
)
285 if (fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, 0, 0)) {
286 logmsg(0, LOG_ERR
, "failed to set %s connection nonblocking: %s",
287 what
, strerror(errno
));
291 if (setsockopt(fd
, SOL_SOCKET
, SO_OOBINLINE
, &yes
, sizeof(yes
))) {
293 "failed to disable `out-of-band' data on %s connection: %s",
294 what
, strerror(errno
));
301 /*----- Client output functions -------------------------------------------*/
303 static void disconnect_client(struct client
*c
);
305 /* Notification that output has been written. If successful, re-enable the
306 * input buffer and prepare for another query.
308 static void done_client_write(int err
, void *p
)
310 struct client
*c
= p
;
313 selbuf_enable(&c
->b
);
315 logmsg(&c
->q
, LOG_ERR
, "failed to send reply: %s", strerror(err
));
316 disconnect_client(c
);
320 /* Format the message FMT and queue it to be sent to the client. Client
321 * input will be disabled until the write completes.
323 static void PRINTF_LIKE(2, 3)
324 write_to_client(struct client
*c
, const char *fmt
, ...)
331 n
= vsnprintf(buf
, sizeof(buf
), fmt
, ap
);
333 logmsg(&c
->q
, LOG_ERR
, "failed to format output: %s", strerror(errno
));
334 disconnect_client(c
);
336 } else if (n
> sizeof(buf
)) {
337 logmsg(&c
->q
, LOG_ERR
, "output too long for client send buffer");
338 disconnect_client(c
);
342 selbuf_disable(&c
->b
);
343 if (queue_write(&c
->wb
, buf
, n
)) {
344 logmsg(&c
->q
, LOG_ERR
, "write buffer overflow");
345 disconnect_client(c
);
349 /* Format a reply to the client, with the form LPORT:RPORT:TY:TOK0[:TOK1].
350 * Typically, TY will be `ERROR' or `USERID'. In the former case, TOK0 will
351 * be the error token and TOK1 will be null; in the latter case, TOK0 will be
352 * the operating system and TOK1 the user name.
354 static void reply(struct client
*c
, const char *ty
,
355 const char *tok0
, const char *tok1
)
357 write_to_client(c
, "%u,%u:%s:%s%s%s\r\n",
358 c
->q
.s
[L
].port
, c
->q
.s
[R
].port
, ty
,
359 tok0
, tok1 ?
":" : "", tok1 ? tok1
: "");
362 /* Mapping from error codes to their protocol tokens. */
363 const char *const errtok
[] = {
364 #define DEFTOK(err, tok) tok,
369 /* Report an error with code ERR to the client. */
370 static void reply_error(struct client
*c
, unsigned err
)
372 assert(err
< E_LIMIT
);
373 reply(c
, "ERROR", errtok
[err
], 0);
376 /*----- NAT proxy functions -----------------------------------------------*/
378 /* Cancel the proxy operation PX, closing the connection and releasing
379 * resources. This is used for both normal and unexpected closures.
381 static void cancel_proxy(struct proxy
*px
)
387 selbuf_disable(&px
->b
);
390 selbuf_enable(&px
->c
->b
);
391 px
->next
= dead_proxies
;
395 /* Delayed destruction of unsafe parts of proxies. */
396 static void reap_dead_proxies(void)
398 struct proxy
*px
, *pp
;
400 for (px
= dead_proxies
; px
; px
= pp
) {
403 selbuf_destroy(&px
->b
);
404 free_writebuf(&px
->wb
);
411 /* Notification that a line (presumably a reply) has been received from the
412 * server. We should check it, log it, and propagate the answer back.
413 * Whatever happens, this proxy operation is now complete.
415 static void proxy_line(char *line
, size_t sz
, void *p
)
417 struct proxy
*px
= p
;
419 const char *q
= line
;
422 /* Trim trailing space. */
423 while (sz
&& isspace((unsigned char)line
[sz
- 1])) sz
--;
425 /* Parse the port numbers. These should match the request. */
426 if (unum(&q
, &lp
, 1, 65535)) goto syntax
;
427 skipws(&q
); if (*q
!= ',') goto syntax
; q
++;
428 if (unum(&q
, &rp
, 1, 65535)) goto syntax
;
429 skipws(&q
); if (*q
!= ':') goto syntax
; q
++;
430 if (lp
!= px
->c
->q
.u
.nat
.port
|| rp
!= px
->c
->q
.s
[R
].port
) goto syntax
;
432 /* Find out what kind of reply this is. */
433 if (idtoken(&q
, buf
, sizeof(buf
))) goto syntax
;
434 skipws(&q
); if (*q
!= ':') goto syntax
; q
++;
436 if (strcmp(buf
, "ERROR") == 0) {
438 /* Report the error without interpreting it. It might be meaningful to
442 logmsg(&px
->c
->q
, LOG_ERR
, "proxy error from %s: %s", px
->nat
, q
);
443 reply(px
->c
, "ERROR", q
, 0);
445 } else if (strcmp(buf
, "USERID") == 0) {
447 /* Parse out the operating system and user name, and pass them on. */
448 if (idtoken(&q
, buf
, sizeof(buf
))) goto syntax
;
449 skipws(&q
); if (*q
!= ':') goto syntax
; q
++;
451 logmsg(&px
->c
->q
, LOG_ERR
, "user `%s'; proxy = %s, os = %s",
453 reply(px
->c
, "USERID", buf
, q
);
460 /* We didn't understand the message from the client. */
461 logmsg(&px
->c
->q
, LOG_ERR
, "failed to parse response from %s", px
->nat
);
462 reply_error(px
->c
, E_UNKNOWN
);
464 /* All finished, no matter what. */
468 /* Notification that we have written the query to the server. Await a
469 * response if successful.
471 static void done_proxy_write(int err
, void *p
)
473 struct proxy
*px
= p
;
476 logmsg(&px
->c
->q
, LOG_ERR
, "failed to proxy query to %s: %s",
477 px
->nat
, strerror(errno
));
478 reply_error(px
->c
, E_UNKNOWN
);
482 selbuf_enable(&px
->b
);
485 /* Notification that the connection to the server is either established or
486 * failed. In the former case, queue the right query.
488 static void proxy_connected(int fd
, void *p
)
490 struct proxy
*px
= p
;
494 /* If the connection failed then report the problem and give up. */
496 logmsg(&px
->c
->q
, LOG_ERR
,
497 "failed to make %s proxy connection to %s: %s",
498 px
->c
->l
->ao
->name
, px
->nat
, strerror(errno
));
499 reply_error(px
->c
, E_UNKNOWN
);
504 /* We're now ready to go, so set things up. */
506 selbuf_init(&px
->b
, &sel
, fd
, proxy_line
, px
);
507 selbuf_setsize(&px
->b
, 1024);
508 selbuf_disable(&px
->b
);
509 init_writebuf(&px
->wb
, fd
, done_proxy_write
, px
);
511 /* Write the query. This buffer is large enough because we've already
512 * range-checked the remote the port number and the local one came from the
513 * kernel, which we trust not to do anything stupid.
515 n
= sprintf(buf
, "%u,%u\r\n", px
->c
->q
.u
.nat
.port
, px
->c
->q
.s
[R
].port
);
516 queue_write(&px
->wb
, buf
, n
);
519 /* Proxy the query through to a client machine for which we're providing NAT
522 static void proxy_query(struct client
*c
)
525 struct sockaddr_storage ss
;
530 /* Allocate the context structure for the NAT. */
531 px
= xmalloc(sizeof(*px
));
533 /* We'll use the client host's address in lots of log messages, so we may
534 * as well format it once and use it over and over.
536 inet_ntop(c
->q
.ao
->af
, &c
->q
.u
.nat
.addr
, px
->nat
, sizeof(px
->nat
));
538 /* Create the socket for the connection. */
539 if ((fd
= socket(c
->q
.ao
->af
, SOCK_STREAM
, 0)) < 0) {
540 logmsg(&c
->q
, LOG_ERR
, "failed to make %s socket for proxy: %s",
541 c
->l
->ao
->name
, strerror(errno
));
544 if (fix_up_socket(fd
, "proxy")) goto err_1
;
546 /* Set up the connection to the client host. The connection interface is a
547 * bit broken: if the connection completes immediately, then the callback
548 * function is called synchronously, and that might decide to shut
549 * everything down. So we must have fully initialized our context before
550 * calling `conn_init', and mustn't touch it again afterwards -- since the
551 * block may have been freed.
555 c
->l
->ao
->socket_to_sockaddr(&s
, &ss
, &ssz
);
556 selbuf_disable(&c
->b
);
557 c
->px
= px
; px
->c
= c
;
559 if (conn_init(&px
->cn
, &sel
, fd
, (struct sockaddr
*)&ss
, ssz
,
560 proxy_connected
, px
)) {
561 logmsg(&c
->q
, LOG_ERR
, "failed to make %s proxy connection to %s: %s",
562 c
->l
->ao
->name
, px
->nat
, strerror(errno
));
566 /* All ready to go. */
569 /* Tidy up after various kinds of failures. */
571 selbuf_enable(&c
->b
);
576 reply_error(c
, E_UNKNOWN
);
579 /*----- Client connection functions ---------------------------------------*/
581 /* Disconnect a client, freeing up any associated resources. */
582 static void disconnect_client(struct client
*c
)
584 selbuf_disable(&c
->b
);
587 free_writebuf(&c
->wb
);
588 if (c
->px
) cancel_proxy(c
->px
);
589 c
->next
= dead_clients
;
593 /* Throw away dead clients now that we've reached a safe point in the
596 static void reap_dead_clients(void)
598 struct client
*c
, *cc
;
599 for (c
= dead_clients
; c
; c
= cc
) {
601 selbuf_destroy(&c
->b
);
607 /* Time out a client because it's been idle for too long. */
608 static void timeout_client(struct timeval
*tv
, void *p
)
610 struct client
*c
= p
;
611 logmsg(&c
->q
, LOG_NOTICE
, "timing out idle or stuck client");
612 sel_addtimer(&sel
, &c
->t
, tv
, timeout_client
, 0);
613 disconnect_client(c
);
616 /* Reset the client idle timer, as a result of activity. Set EXISTP if
617 * there is an existing timer which needs to be removed.
619 static void reset_client_timer(struct client
*c
, int existp
)
623 gettimeofday(&tv
, 0);
625 if (existp
) sel_rmtimer(&c
->t
);
626 sel_addtimer(&sel
, &c
->t
, &tv
, timeout_client
, c
);
629 /* Write a pseudorandom token into the buffer at P, which must have space for
630 * at least TOKENSZ bytes.
632 #define TOKENRANDSZ 8
633 #define TOKENSZ ((4*TOKENRANDSZ + 5)/3)
634 static void user_token(char *p
)
639 static const char tokmap
[64] =
640 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789.-";
642 /* If there's not enough pseudorandom stuff lying around, then read more
645 if (tokenptr
+ TOKENRANDSZ
>= sizeof(tokenbuf
)) {
646 fill_random(tokenbuf
, sizeof(tokenbuf
));
650 /* Now encode the bytes using a slightly tweaked base-64 encoding. Read
651 * bytes into the accumulator and write out characters while there's
654 for (i
= 0; i
< TOKENRANDSZ
; i
++) {
655 a
= (a
<< 8) | tokenbuf
[tokenptr
++]; b
+= 8;
658 *p
++ = tokmap
[(a
>> b
) & 0x3f];
662 /* If there's anything left in the accumulator then flush it out. */
664 *p
++ = tokmap
[(a
<< (6 - b
)) & 0x3f];
666 /* Null-terminate the token. */
670 /* Notification that a line has been received from the client. Parse it,
671 * find out about the connection it's referring to, apply the relevant
672 * policy rules, and produce a response. This is where almost everything
673 * interesting happens.
675 static void client_line(char *line
, size_t len
, void *p
)
677 struct client
*c
= p
;
679 struct passwd
*pw
= 0;
680 const struct policy
*pol
;
682 struct policy upol
= POLICY_INIT(A_LIMIT
);
683 struct policy_file pf
;
687 /* If the connection has closed, then tidy stuff away. */
688 c
->q
.s
[R
].addr
= c
->raddr
;
689 c
->q
.s
[L
].port
= c
->q
.s
[R
].port
= 0;
691 disconnect_client(c
);
695 /* Client activity, so update the timer. */
696 reset_client_timer(c
, 1);
698 /* See if the policy file has changed since we last looked. If so, try to
699 * read the new version.
701 if (fwatch_update(&polfw
, policyfile
)) {
702 logmsg(0, LOG_INFO
, "reload master policy file `%s'", policyfile
);
703 load_policy_file(policyfile
, &policy
);
706 /* Read the local and remote port numbers into the query structure. */
708 if (unum(&q
, &c
->q
.s
[L
].port
, 1, 65535)) goto bad
;
709 skipws(&q
); if (*q
!= ',') goto bad
; q
++;
710 if (unum(&q
, &c
->q
.s
[R
].port
, 1, 65535)) goto bad
;
711 skipws(&q
); if (*q
) goto bad
;
713 /* Identify the connection. Act on the result. */
718 /* We found a user. Track down the user's password entry, because
719 * we'll want that later. Most of the processing for this case is
722 if ((pw
= getpwuid(c
->q
.u
.uid
)) == 0) {
723 logmsg(&c
->q
, LOG_ERR
, "no passwd entry for user %d", c
->q
.u
.uid
);
724 reply_error(c
, E_NOUSER
);
730 /* We've acted as a NAT for this connection. Proxy the query through
731 * to the actal client host.
737 /* We failed to identify the connection for some reason. We should
738 * already have logged an error, so there's not much to do here.
740 reply_error(c
, c
->q
.u
.error
);
744 /* Something happened that we don't understand. */
748 /* Search the table of policy rules to find a match. */
749 for (i
= 0; i
< DA_LEN(&policy
); i
++) {
750 pol
= &DA(&policy
)[i
];
751 if (!match_policy(pol
, &c
->q
)) continue;
753 /* If this is something simple, then apply the resulting policy rule. */
754 if (pol
->act
.act
!= A_USER
) goto match
;
756 /* The global policy has decided to let the user have a say, so we must
757 * parse the user file.
760 dstr_putf(&d
, "%s/.yaid.policy", pw
->pw_dir
);
761 if (open_policy_file(&pf
, d
.buf
, "user policy file", &c
->q
, OPF_NOENTOK
))
763 while ((t
= read_policy_file(&pf
)) < T_ERROR
) {
765 /* Give up after 100 lines or if there's an error. If the user's
766 * policy is that complicated, something's gone very wrong. Or there's
767 * too much commentary or something.
770 logmsg(&c
->q
, LOG_ERR
, "%s:%d: user policy file too long",
775 /* If this was a blank line, just go around again. */
776 if (t
!= T_OK
) continue;
778 /* If this isn't a match, go around for the next rule. */
779 if (!match_policy(&pf
.p
, &c
->q
)) continue;
781 /* Check that the user is allowed to request this action. If not, see
782 * if there's a more acceptable action later on.
784 if (!(pol
->act
.u
.user
& (1 << pf
.p
.act
.act
))) {
785 logmsg(&c
->q
, LOG_ERR
,
786 "%s:%d: user action forbidden by global policy",
791 /* We've found a match, so grab it, close the file, and say we're
794 upol
= pf
.p
; pol
= &upol
;
796 close_policy_file(&pf
);
800 close_policy_file(&pf
);
804 /* No match: apply the built-in default policy. */
805 pol
= &default_policy
;
808 switch (pol
->act
.act
) {
811 /* Report the actual user's name. */
812 logmsg(&c
->q
, LOG_INFO
, "user `%s' (%d)", pw
->pw_name
, c
->q
.u
.uid
);
813 reply(c
, "USERID", "UNIX", pw
->pw_name
);
817 /* Report an arbitrary token which we can look up in our log file. */
819 logmsg(&c
->q
, LOG_INFO
, "user `%s' (%d); token = %s",
820 pw
->pw_name
, c
->q
.u
.uid
, buf
);
821 reply(c
, "USERID", "OTHER", buf
);
825 /* Deny that there's anyone there at all. */
826 logmsg(&c
->q
, LOG_INFO
, "user `%s' (%d); denying",
827 pw
->pw_name
, c
->q
.u
.uid
);
831 /* Report the user as being hidden. */
832 logmsg(&c
->q
, LOG_INFO
, "user `%s' (%d); hiding",
833 pw
->pw_name
, c
->q
.u
.uid
);
834 reply_error(c
, E_HIDDEN
);
838 /* Tell an egregious lie about who the user is. */
839 logmsg(&c
->q
, LOG_INFO
, "user `%s' (%d); lie = `%s'",
840 pw
->pw_name
, c
->q
.u
.uid
, pol
->act
.u
.lie
);
841 reply(c
, "USERID", "UNIX", pol
->act
.u
.lie
);
845 /* Something has gone very wrong. */
854 logmsg(&c
->q
, LOG_ERR
, "failed to parse query from client");
855 disconnect_client(c
);
858 /* Notification that a new client has connected. Prepare to read a query. */
859 static void accept_client(int fd
, unsigned mode
, void *p
)
861 struct listen
*l
= p
;
863 struct sockaddr_storage ssr
, ssl
;
864 socklen_t ssz
= sizeof(ssr
);
867 /* Accept the new connection. */
868 if ((sk
= accept(fd
, (struct sockaddr
*)&ssr
, &ssz
)) < 0) {
869 if (errno
!= EAGAIN
&& errno
== EWOULDBLOCK
) {
870 logmsg(0, LOG_ERR
, "failed to accept incoming %s connection: %s",
871 l
->ao
->name
, strerror(errno
));
875 if (fix_up_socket(sk
, "incoming client")) { close(sk
); return; }
877 /* Build a client block and fill it in. */
878 c
= xmalloc(sizeof(*c
));
882 /* Collect the local and remote addresses. */
883 l
->ao
->sockaddr_to_addr(&ssr
, &c
->raddr
);
885 if (getsockname(sk
, (struct sockaddr
*)&ssl
, &ssz
)) {
887 "failed to read local address for incoming %s connection: %s",
888 l
->ao
->name
, strerror(errno
));
893 l
->ao
->sockaddr_to_addr(&ssl
, &c
->q
.s
[L
].addr
);
894 c
->q
.s
[L
].port
= c
->q
.s
[R
].port
= 0;
896 /* Set stuff up for reading the query and sending responses. */
897 selbuf_init(&c
->b
, &sel
, sk
, client_line
, c
);
898 selbuf_setsize(&c
->b
, 1024);
899 reset_client_timer(c
, 0);
902 init_writebuf(&c
->wb
, sk
, done_client_write
, c
);
905 /*----- Main code ---------------------------------------------------------*/
907 /* Set up a listening socket for the address family described by AO,
910 static int make_listening_socket(const struct addrops
*ao
, int port
)
915 struct sockaddr_storage ss
;
919 /* Make the socket. */
920 if ((fd
= socket(ao
->af
, SOCK_STREAM
, 0)) < 0) {
921 if (errno
== EAFNOSUPPORT
) return (-1);
922 die(1, "failed to create %s listening socket: %s",
923 ao
->name
, strerror(errno
));
926 /* Build the appropriate local address. */
929 ao
->socket_to_sockaddr(&s
, &ss
, &ssz
);
931 /* Perform any initialization specific to the address type. */
932 if (ao
->init_listen_socket(fd
)) {
933 die(1, "failed to initialize %s listening socket: %s",
934 ao
->name
, strerror(errno
));
937 /* Bind to the address. */
938 setsockopt(fd
, SOL_SOCKET
, SO_REUSEADDR
, &yes
, sizeof(yes
));
939 if (bind(fd
, (struct sockaddr
*)&ss
, ssz
)) {
940 die(1, "failed to bind %s listening socket: %s",
941 ao
->name
, strerror(errno
));
944 /* Avoid unpleasant race conditions. */
945 if (fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, 0, 0)) {
946 die(1, "failed to set %s listening socket nonblocking: %s",
947 ao
->name
, strerror(errno
));
950 /* Prepare to listen. */
952 die(1, "failed to listen for %s: %s", ao
->name
, strerror(errno
));
954 /* Make a record of all of this. */
955 l
= xmalloc(sizeof(*l
));
957 sel_initfile(&sel
, &l
->f
, fd
, SEL_READ
, accept_client
, l
);
964 /* Quit because of a fatal signal. */
965 static void NORETURN
quit(int sig
, void *p
)
967 const char *signame
= p
;
969 logmsg(0, LOG_NOTICE
, "shutting down on %s", signame
);
970 if (pidfile
) unlink(pidfile
);
974 /* Answer whether the string pointed to by P consists entirely of digits. */
975 static int numericp(const char *p
)
978 if (!isdigit((unsigned char)*p
++)) return (0);
982 static void usage(FILE *fp
)
984 pquis(fp
, "Usage: $ [-Dl] [-G GROUP] [-U USER] [-P FILE] "
985 "[-c FILE] [-p PORT]\n");
988 static void version(FILE *fp
)
989 { pquis(fp
, "$, version " VERSION
"\n"); }
991 static void help(FILE *fp
)
993 version(fp
); fputc('\n', fp
);
996 Yet Another Ident Daemon. Really, the world doesn't need such a thing.\n\
997 It's just a shame none of the others do the right things.\n\
1001 -h, --help Show this help message.\n\
1002 -v, --version Show the version number.\n\
1003 -u, --usage Show a very short usage summary.\n\
1005 -D, --daemon Become a daemon, running in the background.\n\
1006 -G, --group=GROUP Set group after initialization.\n\
1007 -P, --pidfile=FILE Write process id to FILE.\n\
1008 -U, --user=USER Set user after initialization.\n\
1009 -c, --config=FILE Read global policy from FILE.\n\
1010 -l, --syslog Write log messages using syslog(3).\n\
1011 -p, --port=PORT Listen for connections on this port.\n",
1015 int main(int argc
, char *argv
[])
1020 struct passwd
*pw
= 0;
1023 sig sigint
, sigterm
;
1029 const struct addrops
*ao
;
1034 /* Parse command-line options. */
1036 const struct option opts
[] = {
1037 { "help", 0, 0, 'h' },
1038 { "version", 0, 0, 'v' },
1039 { "usage", 0, 0, 'u' },
1040 { "daemon", 0, 0, 'D' },
1041 { "group", OPTF_ARGREQ
, 0, 'G' },
1042 { "pidfile", OPTF_ARGREQ
, 0, 'P' },
1043 { "user", OPTF_ARGREQ
, 0, 'U' },
1044 { "config", OPTF_ARGREQ
, 0, 'c' },
1045 { "syslog", 0, 0, 'l' },
1046 { "port", OPTF_ARGREQ
, 0, 'p' },
1050 if ((i
= mdwopt(argc
, argv
, "hvuDG:P:U:c:lp:", opts
, 0, 0, 0)) < 0)
1053 case 'h': help(stdout
); exit(0);
1054 case 'v': version(stdout
); exit(0);
1055 case 'u': usage(stdout
); exit(0);
1056 case 'D': f
|= f_daemon
; break;
1057 case 'P': pidfile
= optarg
; break;
1058 case 'c': policyfile
= optarg
; break;
1059 case 'l': flags
|= F_SYSLOG
; break;
1061 if (numericp(optarg
))
1063 else if ((gr
= getgrnam(optarg
)) == 0)
1064 die(1, "unknown group `%s'", optarg
);
1069 if (numericp(optarg
))
1071 else if ((pw
= getpwnam(optarg
)) == 0)
1072 die(1, "unknown user `%s'", optarg
);
1077 if (numericp(optarg
))
1078 port
= atoi(optarg
);
1079 else if ((s
= getservbyname(optarg
, "tcp")) == 0)
1080 die(1, "unknown service name `%s'", optarg
);
1082 port
= ntohs(s
->s_port
);
1084 default: f
|= f_bogus
; break;
1087 if (optind
< argc
) f
|= f_bogus
;
1088 if (f
& f_bogus
) { usage(stderr
); exit(1); }
1090 /* If a user has been requested, but no group, then find the user's primary
1091 * group. If the user was given by name, then we already have a password
1092 * entry and should use that, in case two differently-named users have the
1093 * same uid but distinct gids.
1095 if (u
!= -1 && g
== -1) {
1096 if (!pw
&& (pw
= getpwuid(u
)) == 0) {
1097 die(1, "failed to find password entry for user %d: "
1098 "request group explicitly", u
);
1103 /* Initialize system-specific machinery. */
1106 /* Load the global policy rules. */
1107 fwatch_init(&polfw
, policyfile
);
1108 if (load_policy_file(policyfile
, &policy
))
1111 /* Set up the I/O event system. */
1114 /* Watch for some interesting signals. */
1116 sig_add(&sigint
, SIGINT
, quit
, "SIGINT");
1117 sig_add(&sigterm
, SIGTERM
, quit
, "SIGTERM");
1119 /* Listen for incoming connections. */
1120 for (ao
= addroptab
; ao
->name
; ao
++)
1121 if (!make_listening_socket(ao
, port
)) any
= 1;
1122 if (!any
) die(1, "no IP protocols supported");
1124 /* Open the pidfile now, in case it's somewhere we can't write. */
1125 if (pidfile
&& (fp
= fopen(pidfile
, "w")) == 0) {
1126 die(1, "failed to open pidfile `%s' for writing: %s",
1127 pidfile
, strerror(errno
));
1130 /* If we're meant to use syslog, then open the log. */
1131 if (flags
& F_SYSLOG
)
1132 openlog(QUIS
, 0, LOG_DAEMON
);
1134 /* Drop privileges. */
1135 if ((g
!= -1 && (setegid(g
) || setgid(g
) ||
1136 (getuid() == 0 && setgroups(1, &g
)))) ||
1137 (u
!= -1 && setuid(u
)))
1138 die(1, "failed to drop privileges: %s", strerror(errno
));
1140 /* Become a background process, if requested. */
1141 if ((f
& f_daemon
) && daemonize())
1142 die(1, "failed to become daemon: %s", strerror(errno
));
1144 /* Write the process id to the pidfile. */
1146 fprintf(fp
, "%d\n", getpid());
1150 /* And now we're going. */
1153 /* Read events and process them. */
1155 if (sel_select(&sel
) && errno
!= EINTR
)
1156 die(1, "select failed: %s", strerror(errno
));
1157 reap_dead_proxies();
1158 reap_dead_clients();
1161 /* This just keeps the compiler happy. */
1165 /*----- That's all, folks -------------------------------------------------*/