232a7796997cc6f48746fc3b9ed0165c7bf34310
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 */
66 /* A proxy connection. */
68 int fd
; /* Connection; -1 if in progress */
69 struct client
*c
; /* Back to the client */
70 conn cn
; /* Nonblocking connection */
71 selbuf b
; /* Accumulate the response line */
72 struct writebuf wb
; /* Write buffer for query */
73 char nat
[ADDRLEN
]; /* Server address, as text */
76 /*----- Static variables --------------------------------------------------*/
78 static sel_state sel
; /* I/O multiplexer state */
80 static const char *pidfile
= 0; /* Where to write daemon's pid */
82 static const char *policyfile
= POLICYFILE
; /* Filename for global policy */
83 static const struct policy default_policy
= POLICY_INIT(A_NAME
);
84 static policy_v policy
= DA_INIT
; /* Vector of global policy rules */
85 static fwatch polfw
; /* Watch policy file for changes */
87 static unsigned char tokenbuf
[4096]; /* Random-ish data for tokens */
88 static size_t tokenptr
= sizeof(tokenbuf
); /* Current read position */
89 static int randfd
; /* File descriptor for random data */
91 static unsigned flags
= 0; /* Various interesting flags */
92 #define F_SYSLOG 1u /* Use syslog for logging */
93 #define F_RUNNING 2u /* Running properly now */
95 /*----- Ident protocol parsing --------------------------------------------*/
97 /* Advance *PP over whitespace characters. */
98 static void skipws(const char **pp
)
99 { while (isspace((unsigned char )**pp
)) (*pp
)++; }
101 /* Copy a token of no more than N bytes starting at *PP into Q, advancing *PP
104 static int idtoken(const char **pp
, char *q
, size_t n
)
111 if (*p
== ':' || *p
<= 32 || *p
>= 127) break;
121 /* Read an unsigned decimal number from *PP, and store it in *II. Check that
122 * it's between MIN and MAX, and advance *PP over it. Return zero for
123 * success, or nonzero if something goes wrong.
125 static int unum(const char **pp
, unsigned *ii
, unsigned min
, unsigned max
)
132 if (!isdigit((unsigned char)**pp
)) return (-1);
133 e
= errno
; errno
= 0;
134 i
= strtoul(*pp
, &q
, 10);
135 if (errno
) return (-1);
138 if (i
< min
|| i
> max
) return (-1);
143 /*----- Asynchronous writing ----------------------------------------------*/
145 /* Callback for actually writing stuff from a `writebuf'. */
146 static void write_out(int fd
, unsigned mode
, void *p
)
149 struct writebuf
*wb
= p
;
151 /* Try to write something. */
152 if ((n
= write(fd
, wb
->buf
+ wb
->o
, wb
->n
)) < 0) {
153 if (errno
== EAGAIN
|| errno
== EWOULDBLOCK
) return;
156 wb
->func(errno
, wb
->p
);
161 /* If there's nothing left then restore the buffer to its empty state. */
169 /* Queue N bytes starting at P to be written. */
170 static int queue_write(struct writebuf
*wb
, const void *p
, size_t n
)
172 /* Maybe there's nothing to actually do. */
175 /* Make sure it'll fit. */
176 if (wb
->n
- wb
->o
+ n
> WRBUFSZ
) return (-1);
178 /* If there's anything there already, then make sure it's at the start of
179 * the available space.
182 memmove(wb
->buf
, wb
->buf
+ wb
->o
, wb
->n
);
186 /* If there's nothing currently there, then we're not requesting write
187 * notifications, so set that up, and force an initial wake-up.
190 sel_addfile(&wb
->wr
);
194 /* Copy the new material over. */
195 memcpy(wb
->buf
+ wb
->n
, p
, n
);
202 /* Release resources allocated to WB. */
203 static void free_writebuf(struct writebuf
*wb
)
204 { if (wb
->n
) sel_rmfile(&wb
->wr
); }
206 /* Initialize a writebuf in *WB, writing to file descriptor FD. On
207 * completion, call FUNC, passing it P and an error indicator: either 0 for
208 * success or an `errno' value on failure.
210 static void init_writebuf(struct writebuf
*wb
,
211 int fd
, void (*func
)(int, void *), void *p
)
213 sel_initfile(&sel
, &wb
->wr
, fd
, SEL_WRITE
, write_out
, wb
);
219 /*----- General utilities -------------------------------------------------*/
221 /* Format and log MSG somewhere sensible, at the syslog(3) priority PRIO.
222 * Prefix it with a description of the query Q, if non-null.
224 void logmsg(const struct query
*q
, int prio
, const char *msg
, ...)
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
);
242 if (!(flags
& F_RUNNING
))
244 else if (flags
& F_SYSLOG
)
245 syslog(prio
, "%s", d
.buf
);
249 strftime(buf
, sizeof(buf
), "%Y-%m-%d %H:%M:%S %z", tm
);
250 fprintf(stderr
, "%s %s: %s\n", buf
, QUIS
, d
.buf
);
256 /* Fix up a socket FD so that it won't bite us. Returns zero on success, or
259 static int fix_up_socket(int fd
, const char *what
)
263 if (fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, 0, 0)) {
264 logmsg(0, LOG_ERR
, "failed to set %s connection nonblocking: %s",
265 what
, strerror(errno
));
269 if (setsockopt(fd
, SOL_SOCKET
, SO_OOBINLINE
, &yes
, sizeof(yes
))) {
271 "failed to disable `out-of-band' data on %s connection: %s",
272 what
, strerror(errno
));
279 /*----- Client output functions -------------------------------------------*/
281 static void disconnect_client(struct client
*c
);
283 /* Notification that output has been written. If successful, re-enable the
284 * input buffer and prepare for another query.
286 static void done_client_write(int err
, void *p
)
288 struct client
*c
= p
;
291 selbuf_enable(&c
->b
);
293 logmsg(&c
->q
, LOG_ERR
, "failed to send reply: %s", strerror(err
));
294 disconnect_client(c
);
298 /* Format the message FMT and queue it to be sent to the client. Client
299 * input will be disabled until the write completes.
301 static void write_to_client(struct client
*c
, const char *fmt
, ...)
308 n
= vsnprintf(buf
, sizeof(buf
), fmt
, ap
);
310 logmsg(&c
->q
, LOG_ERR
, "failed to format output: %s", strerror(errno
));
311 disconnect_client(c
);
313 } else if (n
> sizeof(buf
)) {
314 logmsg(&c
->q
, LOG_ERR
, "output too long for client send buffer");
315 disconnect_client(c
);
319 selbuf_disable(&c
->b
);
320 if (queue_write(&c
->wb
, buf
, n
)) {
321 logmsg(&c
->q
, LOG_ERR
, "write buffer overflow");
322 disconnect_client(c
);
326 /* Format a reply to the client, with the form LPORT:RPORT:TY:TOK0[:TOK1].
327 * Typically, TY will be `ERROR' or `USERID'. In the former case, TOK0 will
328 * be the error token and TOK1 will be null; in the latter case, TOK0 will be
329 * the operating system and TOK1 the user name.
331 static void reply(struct client
*c
, const char *ty
,
332 const char *tok0
, const char *tok1
)
334 write_to_client(c
, "%u,%u:%s:%s%s%s\r\n",
335 c
->q
.s
[L
].port
, c
->q
.s
[R
].port
, ty
,
336 tok0
, tok1 ?
":" : "", tok1 ? tok1
: "");
339 /* Mapping from error codes to their protocol tokens. */
340 const char *const errtok
[] = {
341 #define DEFTOK(err, tok) tok,
346 /* Report an error with code ERR to the client. */
347 static void reply_error(struct client
*c
, unsigned err
)
349 assert(err
< E_LIMIT
);
350 reply(c
, "ERROR", errtok
[err
], 0);
353 /*----- NAT proxy functions -----------------------------------------------*/
355 /* Cancel the proxy operation PX, closing the connection and releasing
356 * resources. This is used for both normal and unexpected closures.
358 static void cancel_proxy(struct proxy
*px
)
364 selbuf_destroy(&px
->b
);
365 free_writebuf(&px
->wb
);
367 selbuf_enable(&px
->c
->b
);
372 /* Notification that a line (presumably a reply) has been received from the
373 * server. We should check it, log it, and propagate the answer back.
374 * Whatever happens, this proxy operation is now complete.
376 static void proxy_line(char *line
, size_t sz
, void *p
)
378 struct proxy
*px
= p
;
380 const char *q
= line
;
383 /* Trim trailing space. */
384 while (sz
&& isspace((unsigned char)line
[sz
- 1])) sz
--;
386 /* Parse the port numbers. These should match the request. */
387 if (unum(&q
, &lp
, 1, 65535)) goto syntax
;
388 skipws(&q
); if (*q
!= ',') goto syntax
; q
++;
389 if (unum(&q
, &rp
, 1, 65535)) goto syntax
;
390 skipws(&q
); if (*q
!= ':') goto syntax
; q
++;
391 if (lp
!= px
->c
->q
.u
.nat
.port
|| rp
!= px
->c
->q
.s
[R
].port
) goto syntax
;
393 /* Find out what kind of reply this is. */
394 if (idtoken(&q
, buf
, sizeof(buf
))) goto syntax
;
395 skipws(&q
); if (*q
!= ':') goto syntax
; q
++;
397 if (strcmp(buf
, "ERROR") == 0) {
399 /* Report the error without interpreting it. It might be meaningful to
403 logmsg(&px
->c
->q
, LOG_ERR
, "proxy error from %s: %s", px
->nat
, q
);
404 reply(px
->c
, "ERROR", q
, 0);
406 } else if (strcmp(buf
, "USERID") == 0) {
408 /* Parse out the operating system and user name, and pass them on. */
409 if (idtoken(&q
, buf
, sizeof(buf
))) goto syntax
;
410 skipws(&q
); if (*q
!= ':') goto syntax
; q
++;
412 logmsg(&px
->c
->q
, LOG_ERR
, "user `%s'; proxy = %s, os = %s",
414 reply(px
->c
, "USERID", buf
, q
);
421 /* We didn't understand the message from the client. */
422 logmsg(&px
->c
->q
, LOG_ERR
, "failed to parse response from %s", px
->nat
);
423 reply_error(px
->c
, E_UNKNOWN
);
425 /* All finished, no matter what. */
429 /* Notification that we have written the query to the server. Await a
430 * response if successful.
432 static void done_proxy_write(int err
, void *p
)
434 struct proxy
*px
= p
;
437 logmsg(&px
->c
->q
, LOG_ERR
, "failed to proxy query to %s: %s",
438 px
->nat
, strerror(errno
));
439 reply_error(px
->c
, E_UNKNOWN
);
443 selbuf_enable(&px
->b
);
446 /* Notification that the connection to the server is either established or
447 * failed. In the former case, queue the right query.
449 static void proxy_connected(int fd
, void *p
)
451 struct proxy
*px
= p
;
455 /* If the connection failed then report the problem and give up. */
457 logmsg(&px
->c
->q
, LOG_ERR
,
458 "failed to make %s proxy connection to %s: %s",
459 px
->c
->l
->ao
->name
, px
->nat
, strerror(errno
));
460 reply_error(px
->c
, E_UNKNOWN
);
465 /* We're now ready to go, so set things up. */
467 selbuf_init(&px
->b
, &sel
, fd
, proxy_line
, px
);
468 selbuf_setsize(&px
->b
, 1024);
469 selbuf_disable(&px
->b
);
470 init_writebuf(&px
->wb
, fd
, done_proxy_write
, px
);
472 /* Write the query. This buffer is large enough because we've already
473 * range-checked the remote the port number and the local one came from the
474 * kernel, which we trust not to do anything stupid.
476 n
= sprintf(buf
, "%u,%u\r\n", px
->c
->q
.u
.nat
.port
, px
->c
->q
.s
[R
].port
);
477 queue_write(&px
->wb
, buf
, n
);
480 /* Proxy the query through to a client machine for which we're providing NAT
483 static void proxy_query(struct client
*c
)
486 struct sockaddr_storage ss
;
491 /* Allocate the context structure for the NAT. */
492 px
= xmalloc(sizeof(*px
));
494 /* We'll use the client host's address in lots of log messages, so we may
495 * as well format it once and use it over and over.
497 inet_ntop(c
->q
.ao
->af
, &c
->q
.u
.nat
.addr
, px
->nat
, sizeof(px
->nat
));
499 /* Create the socket for the connection. */
500 if ((fd
= socket(c
->q
.ao
->af
, SOCK_STREAM
, 0)) < 0) {
501 logmsg(&c
->q
, LOG_ERR
, "failed to make %s socket for proxy: %s",
502 c
->l
->ao
->name
, strerror(errno
));
505 if (fix_up_socket(fd
, "proxy")) goto err_1
;
507 /* Set up the connection to the client host. The connection interface is a
508 * bit broken: if the connection completes immediately, then the callback
509 * function is called synchronously, and that might decide to shut
510 * everything down. So we must have fully initialized our context before
511 * calling `conn_init', and mustn't touch it again afterwards -- since the
512 * block may have been freed.
516 c
->l
->ao
->socket_to_sockaddr(&s
, &ss
, &ssz
);
517 selbuf_disable(&c
->b
);
518 c
->px
= px
; px
->c
= c
;
520 if (conn_init(&px
->cn
, &sel
, fd
, (struct sockaddr
*)&ss
, ssz
,
521 proxy_connected
, px
)) {
522 logmsg(&c
->q
, LOG_ERR
, "failed to make %s proxy connection to %s: %s",
523 c
->l
->ao
->name
, px
->nat
, strerror(errno
));
527 /* All ready to go. */
530 /* Tidy up after various kinds of failures. */
532 selbuf_enable(&c
->b
);
537 reply_error(c
, E_UNKNOWN
);
540 /*----- Client connection functions ---------------------------------------*/
542 /* Disconnect a client, freeing up any associated resources. */
543 static void disconnect_client(struct client
*c
)
546 selbuf_destroy(&c
->b
);
548 free_writebuf(&c
->wb
);
549 if (c
->px
) cancel_proxy(c
->px
);
553 /* Time out a client because it's been idle for too long. */
554 static void timeout_client(struct timeval
*tv
, void *p
)
556 struct client
*c
= p
;
557 logmsg(&c
->q
, LOG_NOTICE
, "timing out idle or stuck client");
558 sel_addtimer(&sel
, &c
->t
, tv
, timeout_client
, 0);
559 disconnect_client(c
);
562 /* Reset the client idle timer, as a result of activity. Set EXISTP if
563 * there is an existing timer which needs to be removed.
565 static void reset_client_timer(struct client
*c
, int existp
)
569 gettimeofday(&tv
, 0);
571 if (existp
) sel_rmtimer(&c
->t
);
572 sel_addtimer(&sel
, &c
->t
, &tv
, timeout_client
, c
);
575 /* Write a pseudorandom token into the buffer at P, which must have space for
576 * at least TOKENSZ bytes.
578 #define TOKENRANDSZ 8
579 #define TOKENSZ ((4*TOKENRANDSZ + 5)/3)
580 static void user_token(char *p
)
585 static const char tokmap
[64] =
586 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789.-";
588 /* If there's not enough pseudorandom stuff lying around, then read more
591 if (tokenptr
+ TOKENRANDSZ
>= sizeof(tokenbuf
)) {
592 if (read(randfd
, tokenbuf
, sizeof(tokenbuf
)) < sizeof(tokenbuf
))
593 die(1, "unexpected short read or error from `/dev/urandom'");
597 /* Now encode the bytes using a slightly tweaked base-64 encoding. Read
598 * bytes into the accumulator and write out characters while there's
601 for (i
= 0; i
< TOKENRANDSZ
; i
++) {
602 a
= (a
<< 8) | tokenbuf
[tokenptr
++]; b
+= 8;
605 *p
++ = tokmap
[(a
>> b
) & 0x3f];
609 /* If there's anything left in the accumulator then flush it out. */
611 *p
++ = tokmap
[(a
<< (6 - b
)) & 0x3f];
613 /* Null-terminate the token. */
617 /* Notification that a line has been received from the client. Parse it,
618 * find out about the connection it's referring to, apply the relevant
619 * policy rules, and produce a response. This is where almost everything
620 * interesting happens.
622 static void client_line(char *line
, size_t len
, void *p
)
624 struct client
*c
= p
;
626 struct passwd
*pw
= 0;
627 const struct policy
*pol
;
629 struct policy upol
= POLICY_INIT(A_LIMIT
);
630 struct policy_file pf
;
634 /* If the connection has closed, then tidy stuff away. */
635 c
->q
.s
[L
].port
= c
->q
.s
[R
].port
= 0;
637 disconnect_client(c
);
641 /* Client activity, so update the timer. */
642 reset_client_timer(c
, 1);
644 /* See if the policy file has changed since we last looked. If so, try to
645 * read the new version.
647 if (fwatch_update(&polfw
, policyfile
)) {
648 logmsg(0, LOG_INFO
, "reload master policy file `%s'", policyfile
);
649 load_policy_file(policyfile
, &policy
);
652 /* Read the local and remote port numbers into the query structure. */
654 if (unum(&q
, &c
->q
.s
[L
].port
, 1, 65535)) goto bad
;
655 skipws(&q
); if (*q
!= ',') goto bad
; q
++;
656 if (unum(&q
, &c
->q
.s
[R
].port
, 1, 65535)) goto bad
;
657 skipws(&q
); if (*q
) goto bad
;
659 /* Identify the connection. Act on the result. */
660 c
->q
.s
[R
].addr
= c
->raddr
;
665 /* We found a user. Track down the user's password entry, because
666 * we'll want that later. Most of the processing for this case is
669 if ((pw
= getpwuid(c
->q
.u
.uid
)) == 0) {
670 logmsg(&c
->q
, LOG_ERR
, "no passwd entry for user %d", c
->q
.u
.uid
);
671 reply_error(c
, E_NOUSER
);
677 /* We've acted as a NAT for this connection. Proxy the query through
678 * to the actal client host.
684 /* We failed to identify the connection for some reason. We should
685 * already have logged an error, so there's not much to do here.
687 reply_error(c
, c
->q
.u
.error
);
691 /* Something happened that we don't understand. */
695 /* Search the table of policy rules to find a match. */
696 for (i
= 0; i
< DA_LEN(&policy
); i
++) {
697 pol
= &DA(&policy
)[i
];
698 if (!match_policy(pol
, &c
->q
)) continue;
700 /* If this is something simple, then apply the resulting policy rule. */
701 if (pol
->act
.act
!= A_USER
) goto match
;
703 /* The global policy has decided to let the user have a say, so we must
704 * parse the user file.
707 dstr_putf(&d
, "%s/.yaid.policy", pw
->pw_dir
);
708 if (open_policy_file(&pf
, d
.buf
, "user policy file", &c
->q
, OPF_NOENTOK
))
710 while ((t
= read_policy_file(&pf
)) < T_ERROR
) {
712 /* Give up after 100 lines or if there's an error. If the user's
713 * policy is that complicated, something's gone very wrong. Or there's
714 * too much commentary or something.
717 logmsg(&c
->q
, LOG_ERR
, "%s:%d: user policy file too long",
722 /* If this was a blank line, just go around again. */
723 if (t
!= T_OK
) continue;
725 /* If this isn't a match, go around for the next rule. */
726 if (!match_policy(&pf
.p
, &c
->q
)) continue;
728 /* Check that the user is allowed to request this action. If not, see
729 * if there's a more acceptable action later on.
731 if (!(pol
->act
.u
.user
& (1 << pf
.p
.act
.act
))) {
732 logmsg(&c
->q
, LOG_ERR
,
733 "%s:%d: user action forbidden by global policy",
738 /* We've found a match, so grab it, close the file, and say we're
741 upol
= pf
.p
; pol
= &upol
;
743 close_policy_file(&pf
);
747 close_policy_file(&pf
);
751 /* No match: apply the built-in default policy. */
752 pol
= &default_policy
;
755 switch (pol
->act
.act
) {
758 /* Report the actual user's name. */
759 logmsg(&c
->q
, LOG_INFO
, "user `%s' (%d)", pw
->pw_name
, c
->q
.u
.uid
);
760 reply(c
, "USERID", "UNIX", pw
->pw_name
);
764 /* Report an arbitrary token which we can look up in our log file. */
766 logmsg(&c
->q
, LOG_INFO
, "user `%s' (%d); token = %s",
767 pw
->pw_name
, c
->q
.u
.uid
, buf
);
768 reply(c
, "USERID", "OTHER", buf
);
772 /* Deny that there's anyone there at all. */
773 logmsg(&c
->q
, LOG_INFO
, "user `%s' (%d); denying",
774 pw
->pw_name
, c
->q
.u
.uid
);
778 /* Report the user as being hidden. */
779 logmsg(&c
->q
, LOG_INFO
, "user `%s' (%d); hiding",
780 pw
->pw_name
, c
->q
.u
.uid
);
781 reply_error(c
, E_HIDDEN
);
785 /* Tell an egregious lie about who the user is. */
786 logmsg(&c
->q
, LOG_INFO
, "user `%s' (%d); lie = `%s'",
787 pw
->pw_name
, c
->q
.u
.uid
, pol
->act
.u
.lie
);
788 reply(c
, "USERID", "UNIX", pol
->act
.u
.lie
);
792 /* Something has gone very wrong. */
801 logmsg(&c
->q
, LOG_ERR
, "failed to parse query from client");
802 disconnect_client(c
);
805 /* Notification that a new client has connected. Prepare to read a query. */
806 static void accept_client(int fd
, unsigned mode
, void *p
)
808 struct listen
*l
= p
;
810 struct sockaddr_storage ssr
, ssl
;
811 size_t ssz
= sizeof(ssr
);
814 /* Accept the new connection. */
815 if ((sk
= accept(fd
, (struct sockaddr
*)&ssr
, &ssz
)) < 0) {
816 if (errno
!= EAGAIN
&& errno
== EWOULDBLOCK
) {
817 logmsg(0, LOG_ERR
, "failed to accept incoming %s connection: %s",
818 l
->ao
->name
, strerror(errno
));
822 if (fix_up_socket(sk
, "incoming client")) { close(sk
); return; }
824 /* Build a client block and fill it in. */
825 c
= xmalloc(sizeof(*c
));
829 /* Collect the local and remote addresses. */
830 l
->ao
->sockaddr_to_addr(&ssr
, &c
->raddr
);
832 if (getsockname(sk
, (struct sockaddr
*)&ssl
, &ssz
)) {
834 "failed to read local address for incoming %s connection: %s",
835 l
->ao
->name
, strerror(errno
));
840 l
->ao
->sockaddr_to_addr(&ssl
, &c
->q
.s
[L
].addr
);
841 c
->q
.s
[L
].port
= c
->q
.s
[R
].port
= 0;
843 /* Set stuff up for reading the query and sending responses. */
844 selbuf_init(&c
->b
, &sel
, sk
, client_line
, c
);
845 selbuf_setsize(&c
->b
, 1024);
846 reset_client_timer(c
, 0);
849 init_writebuf(&c
->wb
, sk
, done_client_write
, c
);
852 /*----- Main code ---------------------------------------------------------*/
854 /* Set up a listening socket for the address family described by AO,
857 static int make_listening_socket(const struct addrops
*ao
, int port
)
862 struct sockaddr_storage ss
;
866 /* Make the socket. */
867 if ((fd
= socket(ao
->af
, SOCK_STREAM
, 0)) < 0) {
868 if (errno
== EAFNOSUPPORT
) return (-1);
869 die(1, "failed to create %s listening socket: %s",
870 ao
->name
, strerror(errno
));
873 /* Build the appropriate local address. */
876 ao
->socket_to_sockaddr(&s
, &ss
, &ssz
);
878 /* Perform any initialization specific to the address type. */
879 if (ao
->init_listen_socket(fd
)) {
880 die(1, "failed to initialize %s listening socket: %s",
881 ao
->name
, strerror(errno
));
884 /* Bind to the address. */
885 setsockopt(fd
, SOL_SOCKET
, SO_REUSEADDR
, &yes
, sizeof(yes
));
886 if (bind(fd
, (struct sockaddr
*)&ss
, ssz
)) {
887 die(1, "failed to bind %s listening socket: %s",
888 ao
->name
, strerror(errno
));
891 /* Avoid unpleasant race conditions. */
892 if (fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, 0, 0)) {
893 die(1, "failed to set %s listening socket nonblocking: %s",
894 ao
->name
, strerror(errno
));
897 /* Prepare to listen. */
899 die(1, "failed to listen for %s: %s", ao
->name
, strerror(errno
));
901 /* Make a record of all of this. */
902 l
= xmalloc(sizeof(*l
));
904 sel_initfile(&sel
, &l
->f
, fd
, SEL_READ
, accept_client
, l
);
911 /* Quit because of a fatal signal. */
912 static void quit(int sig
, void *p
)
914 const char *signame
= p
;
916 logmsg(0, LOG_NOTICE
, "shutting down on %s", signame
);
917 if (pidfile
) unlink(pidfile
);
921 /* Answer whether the string pointed to by P consists entirely of digits. */
922 static int numericp(const char *p
)
925 if (!isdigit((unsigned char)*p
++)) return (0);
929 static void usage(FILE *fp
)
931 pquis(fp
, "Usage: $ [-Dl] [-G GROUP] [-U USER] [-P FILE] "
932 "[-c FILE] [-p PORT]\n");
935 static void version(FILE *fp
)
936 { pquis(fp
, "$, version " VERSION
"\n"); }
938 static void help(FILE *fp
)
940 version(fp
); fputc('\n', fp
);
943 Yet Another Ident Daemon. Really, the world doesn't need such a thing.\n\
944 It's just a shame none of the others do the right things.\n\
948 -h, --help Show this help message.\n\
949 -v, --version Show the version number.\n\
950 -u, --usage Show a very short usage summary.\n\
952 -D, --daemon Become a daemon, running in the background.\n\
953 -G, --group=GROUP Set group after initialization.\n\
954 -P, --pidfile=FILE Write process id to FILE.\n\
955 -U, --user=USER Set user after initialization.\n\
956 -c, --config=FILE Read global policy from FILE.\n\
957 -l, --syslog Write log messages using syslog(3).\n\
958 -p, --port=PORT Listen for connections on this port.\n",
962 int main(int argc
, char *argv
[])
967 struct passwd
*pw
= 0;
976 const struct addrops
*ao
;
981 /* Parse command-line options. */
983 const struct option opts
[] = {
984 { "help", 0, 0, 'h' },
985 { "version", 0, 0, 'v' },
986 { "usage", 0, 0, 'u' },
987 { "daemon", 0, 0, 'D' },
988 { "group", OPTF_ARGREQ
, 0, 'G' },
989 { "pidfile", OPTF_ARGREQ
, 0, 'P' },
990 { "user", OPTF_ARGREQ
, 0, 'U' },
991 { "config", OPTF_ARGREQ
, 0, 'c' },
992 { "syslog", 0, 0, 'l' },
993 { "port", OPTF_ARGREQ
, 0, 'p' },
997 if ((i
= mdwopt(argc
, argv
, "hvuDG:P:U:c:lp:", opts
, 0, 0, 0)) < 0)
1000 case 'h': help(stdout
); exit(0);
1001 case 'v': version(stdout
); exit(0);
1002 case 'u': usage(stdout
); exit(0);
1003 case 'D': f
|= f_daemon
; break;
1004 case 'P': pidfile
= optarg
; break;
1005 case 'c': policyfile
= optarg
; break;
1006 case 'l': flags
|= F_SYSLOG
; break;
1008 if (numericp(optarg
))
1010 else if ((gr
= getgrnam(optarg
)) == 0)
1011 die(1, "unknown group `%s'", optarg
);
1016 if (numericp(optarg
))
1018 else if ((pw
= getpwnam(optarg
)) == 0)
1019 die(1, "unknown user `%s'", optarg
);
1024 if (numericp(optarg
))
1025 port
= atoi(optarg
);
1026 else if ((s
= getservbyname(optarg
, "tcp")) == 0)
1027 die(1, "unknown service name `%s'", optarg
);
1029 port
= ntohs(s
->s_port
);
1031 default: f
|= f_bogus
; break;
1034 if (optind
< argc
) f
|= f_bogus
;
1035 if (f
& f_bogus
) { usage(stderr
); exit(1); }
1037 /* If a user has been requested, but no group, then find the user's primary
1038 * group. If the user was given by name, then we already have a password
1039 * entry and should use that, in case two differently-named users have the
1040 * same uid but distinct gids.
1042 if (u
!= -1 && g
== -1) {
1043 if (!pw
&& (pw
= getpwuid(u
)) == 0) {
1044 die(1, "failed to find password entry for user %d: "
1045 "request group explicitly", u
);
1050 /* Initialize system-specific machinery. */
1053 /* Load the global policy rules. */
1054 fwatch_init(&polfw
, policyfile
);
1055 if (load_policy_file(policyfile
, &policy
))
1058 /* Open the random data source. */
1059 if ((randfd
= open("/dev/urandom", O_RDONLY
)) < 0) {
1060 die(1, "failed to open `/dev/urandom' for reading: %s",
1064 /* Set up the I/O event system. */
1067 /* Watch for some interesting signals. */
1069 sig_add(&sigint
, SIGINT
, quit
, "SIGINT");
1070 sig_add(&sigterm
, SIGTERM
, quit
, "SIGTERM");
1072 /* Listen for incoming connections. */
1073 for (ao
= addroptab
; ao
->name
; ao
++)
1074 if (!make_listening_socket(ao
, port
)) any
= 1;
1075 if (!any
) die(1, "no IP protocols supported");
1077 /* Open the pidfile now, in case it's somewhere we can't write. */
1078 if (pidfile
&& (fp
= fopen(pidfile
, "w")) == 0) {
1079 die(1, "failed to open pidfile `%s' for writing: %s",
1080 pidfile
, strerror(errno
));
1083 /* If we're meant to use syslog, then open the log. */
1084 if (flags
& F_SYSLOG
)
1085 openlog(QUIS
, 0, LOG_DAEMON
);
1087 /* Drop privileges. */
1088 if ((g
!= -1 && (setegid(g
) || setgid(g
) ||
1089 (getuid() == 0 && setgroups(1, &g
)))) ||
1090 (u
!= -1 && setuid(u
)))
1091 die(1, "failed to drop privileges: %s", strerror(errno
));
1093 /* Become a background process, if requested. */
1094 if ((f
& f_daemon
) && daemonize())
1095 die(1, "failed to become daemon: %s", strerror(errno
));
1097 /* Write the process id to the pidfile. */
1099 fprintf(fp
, "%d\n", getpid());
1103 /* And now we're going. */
1106 /* Read events and process them. */
1108 if (sel_select(&sel
) && errno
!= EINTR
)
1109 die(1, "select failed: %s", strerror(errno
));
1112 /* This just keeps the compiler happy. */
1116 /*----- That's all, folks -------------------------------------------------*/