3 * Make programs use Unix-domain sockets instead of IP
5 * (c) 2008 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of the preload-hacks package.
12 * Preload-hacks are free software; you can redistribute it and/or modify
13 * them under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or (at
15 * your option) any later version.
17 * Preload-hacks are distributed in the hope that it will be useful, but
18 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
19 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
22 * You should have received a copy of the GNU General Public License along
23 * with preload-hacks; if not, write to the Free Software Foundation, Inc.,
24 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
32 /*----- Header files ------------------------------------------------------*/
48 #include <sys/ioctl.h>
49 #include <sys/socket.h>
53 #include <netinet/in.h>
54 #include <arpa/inet.h>
55 #include <netinet/tcp.h>
56 #include <netinet/udp.h>
60 /*----- Data structures ---------------------------------------------------*/
62 enum { UNUSED
, STALE
, USED
}; /* Unix socket status values */
63 enum { WANT_FRESH
, WANT_EXISTING
}; /* Socket address dispositions */
64 enum { DENY
, ALLOW
}; /* ACL verdicts */
66 static int address_families
[] = { AF_INET
, AF_INET6
, -1 };
70 /* Address representations. */
71 typedef union ipaddr
{
76 /* Convenient socket address hacking. */
77 typedef union address
{
79 struct sockaddr_in sin
;
80 struct sockaddr_in6 sin6
;
83 /* Access control list nodes */
84 typedef struct aclnode
{
88 ipaddr minaddr
, maxaddr
;
89 unsigned short minport
, maxport
;
92 /* Implicit bind records */
93 typedef struct impbind
{
96 ipaddr minaddr
, maxaddr
, bindaddr
;
98 enum { EXPLICIT
, SAME
};
100 /* A type for an address range */
101 typedef struct addrrange
{
104 struct { int af
; ipaddr min
, max
; } range
;
107 enum { EMPTY
, ANY
, LOCAL
, RANGE
};
109 /* Local address records */
110 typedef struct full_ipaddr
{
114 #define MAX_LOCAL_IPADDRS 64
115 static full_ipaddr local_ipaddrs
[MAX_LOCAL_IPADDRS
];
116 static int n_local_ipaddrs
;
118 /* General configuration */
120 static char *sockdir
= 0;
121 static int debug
= 0;
122 static unsigned minautoport
= 16384, maxautoport
= 65536;
124 /* Access control lists */
125 static aclnode
*bind_real
, **bind_tail
= &bind_real
;
126 static aclnode
*connect_real
, **connect_tail
= &connect_real
;
127 static impbind
*impbinds
, **impbind_tail
= &impbinds
;
129 /*----- Import the real versions of functions -----------------------------*/
131 /* The list of functions to immport. */
133 _(socket, int, (int, int, int)) \
134 _(socketpair, int, (int, int, int, int *)) \
135 _(connect, int, (int, const struct sockaddr *, socklen_t)) \
136 _(bind, int, (int, const struct sockaddr *, socklen_t)) \
137 _(accept, int, (int, struct sockaddr *, socklen_t *)) \
138 _(getsockname, int, (int, struct sockaddr *, socklen_t *)) \
139 _(getpeername, int, (int, struct sockaddr *, socklen_t *)) \
140 _(getsockopt, int, (int, int, int, void *, socklen_t *)) \
141 _(setsockopt, int, (int, int, int, const void *, socklen_t)) \
142 _(sendto, ssize_t, (int, const void *buf, size_t, int, \
143 const struct sockaddr *to, socklen_t tolen)) \
144 _(recvfrom, ssize_t, (int, void *buf, size_t, int, \
145 struct sockaddr *from, socklen_t *fromlen)) \
146 _(sendmsg, ssize_t, (int, const struct msghdr *, int)) \
147 _(recvmsg, ssize_t, (int, struct msghdr *, int)) \
148 _(ioctl, int, (int, unsigned long, ...))
150 /* Function pointers to set up. */
151 #define DECL(imp, ret, args) static ret (*real_##imp) args;
155 /* Import the system calls. */
156 static void import(void)
158 #define IMPORT(imp, ret, args) \
159 real_##imp = (ret (*)args)dlsym(RTLD_NEXT, #imp);
164 /*----- Utilities ---------------------------------------------------------*/
166 /* Socket address casts */
167 #define SA(sa) ((struct sockaddr *)(sa))
168 #define SIN(sa) ((struct sockaddr_in *)(sa))
169 #define SIN6(sa) ((struct sockaddr_in6 *)(sa))
170 #define SUN(sa) ((struct sockaddr_un *)(sa))
173 #define UC(ch) ((unsigned char)(ch))
175 /* Memory allocation */
176 #define NEW(x) ((x) = xmalloc(sizeof(*x)))
177 #define NEWV(x, n) ((x) = xmalloc(sizeof(*x) * (n)))
181 # define D(body) { if (debug) { body } }
182 # define Dpid pid_t pid = debug ? getpid() : -1
188 /* Preservation of error status */
189 #define PRESERVING_ERRNO(body) do { \
190 int _err = errno; { body } errno = _err; \
193 /* Allocate N bytes of memory; abort on failure. */
194 static void *xmalloc(size_t n
)
198 if ((p
= malloc(n
)) == 0) { perror("malloc"); exit(127); }
202 /* Allocate a copy of the null-terminated string P; abort on failure. */
203 static char *xstrdup(const char *p
)
205 size_t n
= strlen(p
) + 1;
206 char *q
= xmalloc(n
);
211 /*----- Address-type hacking ----------------------------------------------*/
213 /* If M is a simple mask, i.e., consists of a sequence of zero bits followed
214 * by a sequence of one bits, then return the length of the latter sequence
215 * (which may be zero); otherwise return -1.
217 static int simple_mask_length(unsigned long m
)
221 while (m
& 1) { n
++; m
>>= 1; }
225 /* Answer whether AF is an interesting address family. */
226 static int family_known_p(int af
)
237 /* Return the socket address length for address family AF. */
238 static socklen_t
family_socklen(int af
)
241 case AF_INET
: return (sizeof(struct sockaddr_in
));
242 case AF_INET6
: return (sizeof(struct sockaddr_in6
));
247 /* Return the width of addresses of kind AF. */
248 static int address_width(int af
)
251 case AF_INET
: return 32;
252 case AF_INET6
: return 128;
257 /* If addresses A and B share a common prefix then return its length;
258 * otherwise return -1.
260 static int common_prefix_length(int af
, const ipaddr
*a
, const ipaddr
*b
)
264 unsigned long aa
= ntohl(a
->v4
.s_addr
), bb
= ntohl(b
->v4
.s_addr
);
265 unsigned long m
= aa
^bb
;
266 if ((aa
&m
) == 0 && (bb
&m
) == m
) return (32 - simple_mask_length(m
));
270 const uint8_t *aa
= a
->v6
.s6_addr
, *bb
= b
->v6
.s6_addr
;
275 for (i
= 0; i
< 16 && aa
[i
] == bb
[i
]; i
++);
279 if ((aa
[i
]&m
) != 0 || (bb
[i
]&m
) != m
) return (-1);
280 n
+= 8 - simple_mask_length(m
);
281 for (i
++; i
< 16; i
++)
282 if (aa
[i
] || bb
[i
] != 0xff) return (-1);
291 /* Extract the port number (in host byte-order) from SA. */
292 static int port_from_sockaddr(const struct sockaddr
*sa
)
294 switch (sa
->sa_family
) {
295 case AF_INET
: return (ntohs(SIN(sa
)->sin_port
));
296 case AF_INET6
: return (ntohs(SIN6(sa
)->sin6_port
));
301 /* Store the port number PORT (in host byte-order) in SA. */
302 static void port_to_sockaddr(struct sockaddr
*sa
, int port
)
304 switch (sa
->sa_family
) {
305 case AF_INET
: SIN(sa
)->sin_port
= htons(port
); break;
306 case AF_INET6
: SIN6(sa
)->sin6_port
= htons(port
); break;
311 /* Extract the address part from SA and store it in A. */
312 static void ipaddr_from_sockaddr(ipaddr
*a
, const struct sockaddr
*sa
)
314 switch (sa
->sa_family
) {
315 case AF_INET
: a
->v4
= SIN(sa
)->sin_addr
; break;
316 case AF_INET6
: a
->v6
= SIN6(sa
)->sin6_addr
; break;
321 /* Store the address A in SA. */
322 static void ipaddr_to_sockaddr(struct sockaddr
*sa
, const ipaddr
*a
)
324 switch (sa
->sa_family
) {
326 SIN(sa
)->sin_addr
= a
->v4
;
329 SIN6(sa
)->sin6_addr
= a
->v6
;
330 SIN6(sa
)->sin6_scope_id
= 0;
331 SIN6(sa
)->sin6_flowinfo
= 0;
338 /* Copy a whole socket address about. */
339 static void copy_sockaddr(struct sockaddr
*sa_dst
,
340 const struct sockaddr
*sa_src
)
341 { memcpy(sa_dst
, sa_src
, family_socklen(sa_src
->sa_family
)); }
343 /* Answer whether two addresses are equal. */
344 static int ipaddr_equal_p(int af
, const ipaddr
*a
, const ipaddr
*b
)
347 case AF_INET
: return (a
->v4
.s_addr
== b
->v4
.s_addr
);
348 case AF_INET6
: return (memcmp(a
->v6
.s6_addr
, b
->v6
.s6_addr
, 16) == 0);
353 /* Answer whether the address part of SA is between A and B (inclusive). We
354 * assume that SA has the correct address family.
356 static int sockaddr_in_range_p(const struct sockaddr
*sa
,
357 const ipaddr
*a
, const ipaddr
*b
)
359 switch (sa
->sa_family
) {
361 unsigned long addr
= ntohl(SIN(sa
)->sin_addr
.s_addr
);
362 return (ntohl(a
->v4
.s_addr
) <= addr
&&
363 addr
<= ntohl(b
->v4
.s_addr
));
366 const uint8_t *ss
= SIN6(sa
)->sin6_addr
.s6_addr
;
367 const uint8_t *aa
= a
->v6
.s6_addr
, *bb
= b
->v6
.s6_addr
;
371 for (i
= 0; h
&& l
&& i
< 16; i
++, ss
++, aa
++, bb
++) {
372 if (*ss
< *aa
|| *bb
< *ss
) return (0);
373 if (*aa
< *ss
) l
= 0;
374 if (*ss
< *bb
) h
= 0;
383 /* Fill in SA with the appropriate wildcard address. */
384 static void wildcard_address(int af
, struct sockaddr
*sa
)
388 struct sockaddr_in
*sin
= SIN(sa
);
389 memset(sin
, 0, sizeof(*sin
));
390 sin
->sin_family
= AF_INET
;
392 sin
->sin_addr
.s_addr
= INADDR_ANY
;
395 struct sockaddr_in6
*sin6
= SIN6(sa
);
396 memset(sin6
, 0, sizeof(*sin6
));
397 sin6
->sin6_family
= AF_INET6
;
399 sin6
->sin6_addr
= in6addr_any
;
400 sin6
->sin6_scope_id
= 0;
401 sin6
->sin6_flowinfo
= 0;
408 /* Mask the address A, forcing all but the top PLEN bits to zero or one
409 * according to HIGHP.
411 static void mask_address(int af
, ipaddr
*a
, int plen
, int highp
)
415 unsigned long addr
= ntohl(a
->v4
.s_addr
);
416 unsigned long mask
= plen ?
~0ul << (32 - plen
) : 0;
418 if (highp
) addr
|= ~mask
;
419 a
->v4
.s_addr
= htonl(addr
& 0xffffffff);
423 unsigned m
= (0xff << (8 - plen
%8)) & 0xff;
424 unsigned s
= highp ?
0xff : 0;
426 a
->v6
.s6_addr
[i
] = (a
->v6
.s6_addr
[i
] & m
) | (s
& ~m
);
429 for (; i
< 16; i
++) a
->v6
.s6_addr
[i
] = s
;
436 /* Write a presentation form of SA to BUF, a buffer of length SZ. LEN is the
437 * address length; if it's zero, look it up based on the address family.
438 * Return a pointer to the string (which might, in an emergency, be a static
439 * string rather than your buffer).
441 static char *present_sockaddr(const struct sockaddr
*sa
, socklen_t len
,
442 char *buf
, size_t sz
)
444 #define WANT(n_) do { if (sz < (n_)) goto nospace; } while (0)
445 #define PUTC(c_) do { *buf++ = (c_); sz--; } while (0)
447 if (!sa
) return "<null-address>";
448 if (!sz
) return "<no-space-in-buffer>";
449 if (!len
) len
= family_socklen(sa
->sa_family
);
451 switch (sa
->sa_family
) {
453 struct sockaddr_un
*sun
= SUN(sa
);
454 char *p
= sun
->sun_path
;
455 size_t n
= len
- offsetof(struct sockaddr_un
, sun_path
);
463 case 0: WANT(2); PUTC('\\'); PUTC('0'); break;
464 case '\a': WANT(2); PUTC('\\'); PUTC('a'); break;
465 case '\n': WANT(2); PUTC('\\'); PUTC('n'); break;
466 case '\r': WANT(2); PUTC('\\'); PUTC('r'); break;
467 case '\t': WANT(2); PUTC('\\'); PUTC('t'); break;
468 case '\v': WANT(2); PUTC('\\'); PUTC('v'); break;
469 case '\\': WANT(2); PUTC('\\'); PUTC('\\'); break;
471 if (*p
> ' ' && *p
<= '~')
472 { WANT(1); PUTC(*p
); }
474 WANT(4); PUTC('\\'); PUTC('x');
475 PUTC((*p
>> 4)&0xf); PUTC((*p
>> 0)&0xf);
482 if (*p
!= '/') { WANT(2); PUTC('.'); PUTC('/'); }
483 while (n
&& *p
) { WANT(1); PUTC(*p
); p
++; n
--; }
487 case AF_INET
: case AF_INET6
: {
488 char addrbuf
[NI_MAXHOST
], portbuf
[NI_MAXSERV
];
489 int err
= getnameinfo(sa
, len
,
490 addrbuf
, sizeof(addrbuf
),
491 portbuf
, sizeof(portbuf
),
492 NI_NUMERICHOST
| NI_NUMERICSERV
);
494 snprintf(buf
, sz
, strchr(addrbuf
, ':') ?
"[%s]:%s" : "%s:%s",
498 snprintf(buf
, sz
, "<unknown-address-family %d>", sa
->sa_family
);
508 /* Guess the family of a textual socket address. */
509 static int guess_address_family(const char *p
)
510 { return (strchr(p
, ':') ? AF_INET6
: AF_INET
); }
512 /* Parse a socket address P and write the result to SA. */
513 static int parse_sockaddr(struct sockaddr
*sa
, const char *p
)
517 struct addrinfo
*ai
, ai_hint
= { 0 };
519 if (strlen(p
) >= sizeof(buf
) - 1) return (-1);
520 strcpy(buf
, p
); p
= buf
;
522 if ((q
= strchr(p
, ':')) == 0) return (-1);
526 if ((q
= strchr(p
, ']')) == 0) return (-1);
528 if (*q
!= ':') return (-1);
532 ai_hint
.ai_family
= AF_UNSPEC
;
533 ai_hint
.ai_socktype
= SOCK_DGRAM
;
534 ai_hint
.ai_flags
= AI_NUMERICHOST
| AI_NUMERICSERV
;
535 if (getaddrinfo(p
, q
, &ai_hint
, &ai
)) return (-1);
536 memcpy(sa
, ai
->ai_addr
, ai
->ai_addrlen
);
541 /*----- Access control lists ----------------------------------------------*/
545 static void dump_addrrange(int af
, const ipaddr
*min
, const ipaddr
*max
)
551 plen
= common_prefix_length(af
, min
, max
);
552 p
= inet_ntop(af
, min
, buf
, sizeof(buf
));
553 fprintf(stderr
, strchr(p
, ':') ?
"[%s]" : "%s", p
);
555 p
= inet_ntop(af
, &max
, buf
, sizeof(buf
));
556 fprintf(stderr
, strchr(p
, ':') ?
"-[%s]" : "-%s", p
);
557 } else if (plen
< address_width(af
))
558 fprintf(stderr
, "/%d", plen
);
561 /* Write to standard error a description of the ACL node A. */
562 static void dump_aclnode(const aclnode
*a
)
564 fprintf(stderr
, "noip(%d): %c ", getpid(), a
->act ?
'+' : '-');
565 dump_addrrange(a
->af
, &a
->minaddr
, &a
->maxaddr
);
566 if (a
->minport
!= 0 || a
->maxport
!= 0xffff) {
567 fprintf(stderr
, ":%u", (unsigned)a
->minport
);
568 if (a
->minport
!= a
->maxport
)
569 fprintf(stderr
, "-%u", (unsigned)a
->maxport
);
574 static void dump_acl(const aclnode
*a
)
578 for (; a
; a
= a
->next
) {
582 fprintf(stderr
, "noip(%d): [default policy: %s]\n", getpid(),
583 act
== ALLOW ?
"DENY" : "ALLOW");
588 /* Returns nonzero if the ACL A allows the socket address SA. */
589 static int acl_allows_p(const aclnode
*a
, const struct sockaddr
*sa
)
591 unsigned short port
= port_from_sockaddr(sa
);
595 D({ char buf
[ADDRBUFSZ
];
596 fprintf(stderr
, "noip(%d): check %s\n", pid
,
597 present_sockaddr(sa
, 0, buf
, sizeof(buf
))); })
598 for (; a
; a
= a
->next
) {
599 D( dump_aclnode(a
); )
600 if (sockaddr_in_range_p(sa
, &a
->minaddr
, &a
->maxaddr
) &&
601 a
->minport
<= port
&& port
<= a
->maxport
) {
602 D( fprintf(stderr
, "noip(%d): aha! %s\n", pid
,
603 a
->act ?
"ALLOW" : "DENY"); )
608 D( fprintf(stderr
, "noip(%d): nothing found: %s\n", pid
,
609 act ?
"DENY" : "ALLOW"); )
613 /*----- Socket address conversion -----------------------------------------*/
615 /* Return a uniformly distributed integer between MIN and MAX inclusive. */
616 static unsigned randrange(unsigned min
, unsigned max
)
620 /* It's so nice not to have to care about the quality of the generator
624 for (mask
= 1; mask
< max
; mask
= (mask
<< 1) | 1)
626 do i
= rand() & mask
; while (i
> max
);
630 /* Return the status of Unix-domain socket address SUN. Returns: UNUSED if
631 * the socket doesn't exist; USED if the path refers to an active socket, or
632 * isn't really a socket at all, or we can't tell without a careful search
633 * and QUICKP is set; or STALE if the file refers to a socket which isn't
634 * being used any more.
636 static int unix_socket_status(struct sockaddr_un
*sun
, int quickp
)
644 if (stat(sun
->sun_path
, &st
))
645 return (errno
== ENOENT ? UNUSED
: USED
);
646 if (!S_ISSOCK(st
.st_mode
) || quickp
)
649 if ((fp
= fopen("/proc/net/unix", "r")) == 0)
651 if (!fgets(buf
, sizeof(buf
), fp
)) goto done
; /* skip header */
652 len
= strlen(sun
->sun_path
);
653 while (fgets(buf
, sizeof(buf
), fp
)) {
655 if (n
>= len
+ 2 && buf
[n
- len
- 2] == ' ' && buf
[n
- 1] == '\n' &&
656 memcmp(buf
+ n
- len
- 1, sun
->sun_path
, len
) == 0)
667 /* Convert the IP address SA to a Unix-domain address SUN. Fail if the
668 * address seems already taken. If DESPARATEP then try cleaning up stale old
671 static int encode_unused_inet_addr(struct sockaddr
*sa
,
672 struct sockaddr_un
*sun
,
676 struct sockaddr_un wsun
;
680 snprintf(sun
->sun_path
, sizeof(sun
->sun_path
), "%s/%s", sockdir
,
681 present_sockaddr(sa
, 0, buf
, sizeof(buf
)));
682 if ((rc
= unix_socket_status(sun
, !desperatep
)) == USED
) return (-1);
683 else if (rc
== STALE
) unlink(sun
->sun_path
);
685 wildcard_address(sa
->sa_family
, &waddr
.sa
);
686 port_to_sockaddr(&waddr
.sa
, port_from_sockaddr(sa
));
687 snprintf(wsun
.sun_path
, sizeof(wsun
.sun_path
), "%s/%s", sockdir
,
688 present_sockaddr(&waddr
.sa
, 0, buf
, sizeof(buf
)));
689 if ((rc
= unix_socket_status(&wsun
, !desperatep
)) == USED
) return (-1);
690 else if (rc
== STALE
) unlink(wsun
.sun_path
);
695 /* Encode the Internet address SA as a Unix-domain address SUN. If WANT is
696 * WANT_FRESH, and SA's port number is zero, then we pick an arbitrary local
697 * port. Otherwise we pick the port given. There's an unpleasant hack to
698 * find servers bound to local wildcard addresses. Returns zero on success;
701 static int encode_inet_addr(struct sockaddr_un
*sun
,
702 const struct sockaddr
*sa
,
711 D( fprintf(stderr
, "noip(%d): encode %s (%s)", getpid(),
712 present_sockaddr(sa
, 0, buf
, sizeof(buf
)),
713 want
== WANT_EXISTING ?
"EXISTING" : "FRESH"); )
714 sun
->sun_family
= AF_UNIX
;
715 if (port_from_sockaddr(sa
) || want
== WANT_EXISTING
) {
716 snprintf(sun
->sun_path
, sizeof(sun
->sun_path
), "%s/%s", sockdir
,
717 present_sockaddr(sa
, 0, buf
, sizeof(buf
)));
718 rc
= unix_socket_status(sun
, 0);
719 if (rc
== STALE
) unlink(sun
->sun_path
);
720 if (rc
!= USED
&& want
== WANT_EXISTING
) {
721 wildcard_address(sa
->sa_family
, &addr
.sa
);
722 port_to_sockaddr(&addr
.sa
, port_from_sockaddr(sa
));
723 snprintf(sun
->sun_path
, sizeof(sun
->sun_path
), "%s/%s", sockdir
,
724 present_sockaddr(&addr
.sa
, 0, buf
, sizeof(buf
)));
725 if (unix_socket_status(sun
, 0) == STALE
) unlink(sun
->sun_path
);
728 copy_sockaddr(&addr
.sa
, sa
);
729 for (i
= 0; i
< 10; i
++) {
730 port_to_sockaddr(&addr
.sa
, randrange(minautoport
, maxautoport
));
731 if (!encode_unused_inet_addr(&addr
.sa
, sun
, 0)) goto found
;
733 for (desperatep
= 0; desperatep
< 2; desperatep
++) {
734 for (i
= minautoport
; i
<= maxautoport
; i
++) {
735 port_to_sockaddr(&addr
.sa
, i
);
736 if (!encode_unused_inet_addr(&addr
.sa
, sun
, 0)) goto found
;
740 D( fprintf(stderr
, " -- can't resolve\n"); )
744 D( fprintf(stderr
, " -> `%s'\n", sun
->sun_path
); )
748 /* Decode the Unix address SUN to an Internet address SIN. If AF_HINT is
749 * nonzero, an empty address (indicative of an unbound Unix-domain socket) is
750 * translated to a wildcard Internet address of the appropriate family.
751 * Returns zero on success; -1 on failure (e.g., it wasn't one of our
754 static int decode_inet_addr(struct sockaddr
*sa
, int af_hint
,
755 const struct sockaddr_un
*sun
,
759 size_t n
= strlen(sockdir
), nn
;
762 if (!sa
) sa
= &addr
.sa
;
763 if (sun
->sun_family
!= AF_UNIX
) return (-1);
764 if (len
> sizeof(*sun
)) return (-1);
765 ((char *)sun
)[len
] = 0;
766 nn
= strlen(sun
->sun_path
);
767 D( fprintf(stderr
, "noip(%d): decode `%s'", getpid(), sun
->sun_path
); )
768 if (af_hint
&& !sun
->sun_path
[0]) {
769 wildcard_address(af_hint
, sa
);
770 D( fprintf(stderr
, " -- unbound socket\n"); )
773 if (nn
< n
+ 1 || nn
- n
>= sizeof(buf
) || sun
->sun_path
[n
] != '/' ||
774 memcmp(sun
->sun_path
, sockdir
, n
) != 0) {
775 D( fprintf(stderr
, " -- not one of ours\n"); )
778 if (parse_sockaddr(sa
, sun
->sun_path
+ n
+ 1)) return (-1);
779 D( fprintf(stderr
, " -> %s\n",
780 present_sockaddr(sa
, 0, buf
, sizeof(buf
))); )
784 /* SK is (or at least might be) a Unix-domain socket we created when an
785 * Internet socket was asked for. We've decided it should be an Internet
786 * socket after all, with family AF_HINT, so convert it. If TMP is not null,
787 * then don't replace the existing descriptor: store the new socket in *TMP
790 static int fixup_real_ip_socket(int sk
, int af_hint
, int *tmp
)
795 struct sockaddr_un sun
;
808 _(LINGER, struct linger) \
811 _(RCVTIMEO, struct timeval) \
812 _(SNDTIMEO, struct timeval)
815 if (real_getsockname(sk
, SA(&sun
), &len
))
817 if (decode_inet_addr(&addr
.sa
, af_hint
, &sun
, len
))
818 return (0); /* Not one of ours */
820 if (real_getsockopt(sk
, SOL_SOCKET
, SO_TYPE
, &type
, &len
) < 0 ||
821 (nsk
= real_socket(addr
.sa
.sa_family
, type
, 0)) < 0)
823 #define FIX(opt, ty) do { \
826 if (real_getsockopt(sk, SOL_SOCKET, SO_##opt, &ov_, &len) < 0 || \
827 real_setsockopt(nsk, SOL_SOCKET, SO_##opt, &ov_, len)) { \
837 if ((f
= fcntl(sk
, F_GETFL
)) < 0 ||
838 (fd
= fcntl(sk
, F_GETFD
)) < 0 ||
839 fcntl(nsk
, F_SETFL
, f
) < 0 ||
844 unlink(sun
.sun_path
);
846 if (fcntl(sk
, F_SETFD
, fd
) < 0) {
847 perror("noip: fixup_real_ip_socket F_SETFD");
854 /* We found the real address SA, with length LEN; if it's a Unix-domain
855 * address corresponding to a fake socket, convert it to cover up the
856 * deception. Whatever happens, put the result at FAKE and store its length
859 static void return_fake_name(struct sockaddr
*sa
, socklen_t len
,
860 struct sockaddr
*fake
, socklen_t
*fakelen
)
865 if (sa
->sa_family
== AF_UNIX
&&
866 !decode_inet_addr(&addr
.sa
, 0, SUN(sa
), len
)) {
868 len
= family_socklen(addr
.sa
.sa_family
);
871 if (len
> *fakelen
) len
= *fakelen
;
872 if (len
> 0) memcpy(fake
, sa
, len
);
876 /*----- Implicit binding --------------------------------------------------*/
880 static void dump_impbind(const impbind
*i
)
884 fprintf(stderr
, "noip(%d): ", getpid());
885 dump_addrrange(i
->af
, &i
->minaddr
, &i
->maxaddr
);
887 case SAME
: fprintf(stderr
, " <self>"); break;
889 fprintf(stderr
, " %s", inet_ntop(i
->af
, &i
->bindaddr
,
897 static void dump_impbind_list(void)
901 for (i
= impbinds
; i
; i
= i
->next
) dump_impbind(i
);
906 /* The socket SK is about to be used to communicate with the remote address
907 * SA. Assign it a local address so that getpeername(2) does something
910 static int do_implicit_bind(int sk
, const struct sockaddr
**sa
,
911 socklen_t
*len
, struct sockaddr_un
*sun
)
914 socklen_t mylen
= sizeof(*sun
);
918 if (acl_allows_p(connect_real
, *sa
)) {
919 if (fixup_real_ip_socket(sk
, (*sa
)->sa_family
, 0)) return (-1);
921 if (real_getsockname(sk
, SA(sun
), &mylen
) < 0) return (-1);
922 if (sun
->sun_family
== AF_UNIX
) {
923 if (mylen
< sizeof(*sun
)) ((char *)sun
)[mylen
] = 0;
924 if (!sun
->sun_path
[0]) {
925 D( fprintf(stderr
, "noip(%d): checking impbind list...\n", pid
); )
926 for (i
= impbinds
; i
; i
= i
->next
) {
927 D( dump_impbind(i
); )
928 if ((*sa
)->sa_family
== i
->af
&&
929 sockaddr_in_range_p(*sa
, &i
->minaddr
, &i
->maxaddr
)) {
930 D( fprintf(stderr
, "noip(%d): match!\n", pid
); )
931 addr
.sa
.sa_family
= (*sa
)->sa_family
;
932 ipaddr_to_sockaddr(&addr
.sa
, &i
->bindaddr
);
936 D( fprintf(stderr
, "noip(%d): no match; using wildcard\n", pid
); )
937 wildcard_address((*sa
)->sa_family
, &addr
.sa
);
939 encode_inet_addr(sun
, &addr
.sa
, WANT_FRESH
);
940 if (real_bind(sk
, SA(sun
), SUN_LEN(sun
))) return (-1);
942 encode_inet_addr(sun
, *sa
, WANT_EXISTING
);
950 /*----- Configuration -----------------------------------------------------*/
952 /* Return the process owner's home directory. */
953 static char *home(void)
958 if (getuid() == uid
&&
959 (p
= getenv("HOME")) != 0)
961 else if ((pw
= getpwuid(uid
)) != 0)
967 /* Return a good temporary directory to use. */
968 static char *tmpdir(void)
972 if ((p
= getenv("TMPDIR")) != 0) return (p
);
973 else if ((p
= getenv("TMP")) != 0) return (p
);
974 else return ("/tmp");
977 /* Return the user's name, or at least something distinctive. */
978 static char *user(void)
984 if ((p
= getenv("USER")) != 0) return (p
);
985 else if ((p
= getenv("LOGNAME")) != 0) return (p
);
986 else if ((pw
= getpwuid(uid
)) != 0) return (pw
->pw_name
);
988 snprintf(buf
, sizeof(buf
), "uid-%lu", (unsigned long)uid
);
993 /* Skip P over space characters. */
994 #define SKIPSPC do { while (*p && isspace(UC(*p))) p++; } while (0)
996 /* Set Q to point to the next word following P, null-terminate it, and step P
998 #define NEXTWORD(q) do { \
1001 while (*p && !isspace(UC(*p))) p++; \
1005 /* Set Q to point to the next dotted-quad address, store the ending delimiter
1006 * in DEL, null-terminate it, and step P past it. */
1007 static void parse_nextaddr(char **pp
, char **qq
, int *del
)
1015 p
+= strcspn(p
, "]");
1020 while (*p
&& (*p
== '.' || isdigit(UC(*p
)))) p
++;
1027 /* Set Q to point to the next decimal number, store the ending delimiter in
1028 * DEL, null-terminate it, and step P past it. */
1029 #define NEXTNUMBER(q, del) do { \
1032 while (*p && isdigit(UC(*p))) p++; \
1037 /* Push the character DEL back so we scan it again, unless it's zero
1039 #define RESCAN(del) do { if (del) *--p = del; } while (0)
1041 /* Evaluate true if P is pointing to the word KW (and not some longer string
1042 * of which KW is a prefix). */
1044 #define KWMATCHP(kw) (strncmp(p, kw, sizeof(kw) - 1) == 0 && \
1045 !isalnum(UC(p[sizeof(kw) - 1])) && \
1046 (p += sizeof(kw) - 1))
1048 /* Parse a port list, starting at *PP. Port lists have the form
1049 * [:LOW[-HIGH]]: if omitted, all ports are included; if HIGH is omitted,
1050 * it's as if HIGH = LOW. Store LOW in *MIN, HIGH in *MAX and set *PP to the
1051 * rest of the string.
1053 static void parse_ports(char **pp
, unsigned short *min
, unsigned short *max
)
1060 { *min
= 0; *max
= 0xffff; }
1063 NEXTNUMBER(q
, del
); *min
= strtoul(q
, 0, 0); RESCAN(del
);
1066 { p
++; NEXTNUMBER(q
, del
); *max
= strtoul(q
, 0, 0); RESCAN(del
); }
1073 /* Parse an address range designator starting at PP and store a
1074 * representation of it in R. An address range designator has the form:
1076 * any | local | ADDR | ADDR - ADDR | ADDR/ADDR | ADDR/INT
1078 static int parse_addrrange(char **pp
, addrrange
*r
)
1086 if (KWMATCHP("any")) r
->type
= ANY
;
1087 else if (KWMATCHP("local")) r
->type
= LOCAL
;
1089 parse_nextaddr(&p
, &q
, &del
);
1090 af
= guess_address_family(q
);
1091 if (inet_pton(af
, q
, &r
->u
.range
.min
) <= 0) goto bad
;
1096 parse_nextaddr(&p
, &q
, &del
);
1097 if (inet_pton(af
, q
, &r
->u
.range
.max
) <= 0) goto bad
;
1099 } else if (*p
== '/') {
1102 n
= strtoul(q
, 0, 0);
1103 r
->u
.range
.max
= r
->u
.range
.min
;
1104 mask_address(af
, &r
->u
.range
.min
, n
, 0);
1105 mask_address(af
, &r
->u
.range
.max
, n
, 1);
1108 r
->u
.range
.max
= r
->u
.range
.min
;
1119 /* Call FUNC on each individual address range in R. */
1120 static void foreach_addrrange(const addrrange
*r
,
1121 void (*func
)(int af
,
1127 ipaddr minaddr
, maxaddr
;
1134 for (i
= 0; address_families
[i
] >= 0; i
++) {
1135 af
= address_families
[i
];
1136 memset(&minaddr
, 0, sizeof(minaddr
));
1137 maxaddr
= minaddr
; mask_address(af
, &maxaddr
, 0, 1);
1138 func(af
, &minaddr
, &maxaddr
, p
);
1142 for (i
= 0; address_families
[i
] >= 0; i
++) {
1143 af
= address_families
[i
];
1144 memset(&minaddr
, 0, sizeof(minaddr
));
1145 maxaddr
= minaddr
; mask_address(af
, &maxaddr
, 0, 1);
1146 func(af
, &minaddr
, &minaddr
, p
);
1147 func(af
, &maxaddr
, &maxaddr
, p
);
1149 for (i
= 0; i
< n_local_ipaddrs
; i
++) {
1150 func(local_ipaddrs
[i
].af
,
1151 &local_ipaddrs
[i
].addr
, &local_ipaddrs
[i
].addr
,
1156 func(r
->u
.range
.af
, &r
->u
.range
.min
, &r
->u
.range
.max
, p
);
1163 struct add_aclnode_ctx
{
1165 unsigned short minport
, maxport
;
1169 static void add_aclnode(int af
, const ipaddr
*min
, const ipaddr
*max
,
1172 struct add_aclnode_ctx
*ctx
= p
;
1178 a
->minaddr
= *min
; a
->maxaddr
= *max
;
1179 a
->minport
= ctx
->minport
; a
->maxport
= ctx
->maxport
;
1180 **ctx
->tail
= a
; *ctx
->tail
= &a
->next
;
1183 /* Parse an ACL line. *PP points to the end of the line; *TAIL points to
1184 * the list tail (i.e., the final link in the list). An ACL entry has the
1185 * form +|- ADDR-RANGE PORTS
1186 * where PORTS is parsed by parse_ports above; an ACL line consists of a
1187 * comma-separated sequence of entries..
1189 static void parse_acl_line(char **pp
, aclnode
***tail
)
1191 struct add_aclnode_ctx ctx
;
1198 if (*p
== '+') ctx
.act
= ALLOW
;
1199 else if (*p
== '-') ctx
.act
= DENY
;
1203 if (parse_addrrange(&p
, &r
)) goto bad
;
1204 parse_ports(&p
, &ctx
.minport
, &ctx
.maxport
);
1205 foreach_addrrange(&r
, add_aclnode
, &ctx
);
1207 if (*p
!= ',') break;
1215 D( fprintf(stderr
, "noip(%d): bad acl spec (ignored)\n", getpid()); )
1219 /* Parse an ACL from an environment variable VAR, attaching it to the list
1222 static void parse_acl_env(const char *var
, aclnode
***tail
)
1226 if ((p
= getenv(var
)) != 0) {
1228 parse_acl_line(&q
, tail
);
1233 struct add_impbind_ctx
{
1238 static void add_impbind(int af
, const ipaddr
*min
, const ipaddr
*max
,
1241 struct add_impbind_ctx
*ctx
= p
;
1244 if (ctx
->af
&& af
!= ctx
->af
) return;
1248 i
->minaddr
= *min
; i
->maxaddr
= *max
;
1250 case EXPLICIT
: i
->bindaddr
= ctx
->addr
;
1254 *impbind_tail
= i
; impbind_tail
= &i
->next
;
1257 /* Parse an implicit-bind line. An implicit-bind entry has the form
1258 * ADDR-RANGE {ADDR | same}
1260 static void parse_impbind_line(char **pp
)
1262 struct add_impbind_ctx ctx
;
1268 if (parse_addrrange(&p
, &r
)) goto bad
;
1270 if (KWMATCHP("same")) {
1275 parse_nextaddr(&p
, &q
, &del
);
1276 ctx
.af
= guess_address_family(q
);
1277 if (inet_pton(ctx
.af
, q
, &ctx
.addr
) < 0) goto bad
;
1280 foreach_addrrange(&r
, add_impbind
, &ctx
);
1282 if (*p
!= ',') break;
1290 D( fprintf(stderr
, "noip(%d): bad implicit-bind spec (ignored)\n",
1295 /* Parse implicit-bind instructions from an environment variable VAR,
1296 * attaching it to the list.
1298 static void parse_impbind_env(const char *var
)
1302 if ((p
= getenv(var
)) != 0) {
1304 parse_impbind_line(&q
);
1309 /* Parse the autoports configuration directive. Syntax is MIN - MAX. */
1310 static void parse_autoports(char **pp
)
1317 NEXTNUMBER(q
, del
); x
= strtoul(q
, 0, 0); RESCAN(del
);
1319 if (*p
!= '-') goto bad
;
1321 NEXTNUMBER(q
, del
); y
= strtoul(q
, 0, 0); RESCAN(del
);
1322 minautoport
= x
; maxautoport
= y
;
1323 SKIPSPC
; if (*p
) goto bad
;
1328 D( fprintf(stderr
, "noip(%d): bad port range (ignored)\n", getpid()); )
1332 /* Read the configuration from the config file and environment. */
1333 static void readconfig(void)
1341 parse_acl_env("NOIP_REALBIND_BEFORE", &bind_tail
);
1342 parse_acl_env("NOIP_REALCONNECT_BEFORE", &connect_tail
);
1343 parse_impbind_env("NOIP_IMPBIND_BEFORE");
1344 if ((p
= getenv("NOIP_AUTOPORTS")) != 0) {
1346 parse_autoports(&q
);
1349 if ((p
= getenv("NOIP_CONFIG")) == 0)
1350 snprintf(p
= buf
, sizeof(buf
), "%s/.noip", home());
1351 D( fprintf(stderr
, "noip(%d): config file: %s\n", pid
, p
); )
1353 if ((fp
= fopen(p
, "r")) == 0) {
1354 D( fprintf(stderr
, "noip(%d): couldn't read config: %s\n",
1355 pid
, strerror(errno
)); )
1358 while (fgets(buf
, sizeof(buf
), fp
)) {
1363 if (!*p
|| *p
== '#') continue;
1364 while (n
&& isspace(UC(buf
[n
- 1]))) n
--;
1369 if (strcmp(cmd
, "socketdir") == 0)
1370 sockdir
= xstrdup(p
);
1371 else if (strcmp(cmd
, "realbind") == 0)
1372 parse_acl_line(&p
, &bind_tail
);
1373 else if (strcmp(cmd
, "realconnect") == 0)
1374 parse_acl_line(&p
, &connect_tail
);
1375 else if (strcmp(cmd
, "impbind") == 0)
1376 parse_impbind_line(&p
);
1377 else if (strcmp(cmd
, "autoports") == 0)
1378 parse_autoports(&p
);
1379 else if (strcmp(cmd
, "debug") == 0)
1380 debug
= *p ?
atoi(p
) : 1;
1382 D( fprintf(stderr
, "noip(%d): bad config command %s\n", pid
, cmd
); )
1387 parse_acl_env("NOIP_REALBIND", &bind_tail
);
1388 parse_acl_env("NOIP_REALCONNECT", &connect_tail
);
1389 parse_impbind_env("NOIP_IMPBIND");
1390 parse_acl_env("NOIP_REALBIND_AFTER", &bind_tail
);
1391 parse_acl_env("NOIP_REALCONNECT_AFTER", &connect_tail
);
1392 parse_impbind_env("NOIP_IMPBIND_AFTER");
1396 if (!sockdir
) sockdir
= getenv("NOIP_SOCKETDIR");
1398 snprintf(buf
, sizeof(buf
), "%s/noip-%s", tmpdir(), user());
1399 sockdir
= xstrdup(buf
);
1401 D( fprintf(stderr
, "noip(%d): socketdir: %s\n", pid
, sockdir
);
1402 fprintf(stderr
, "noip(%d): autoports: %u-%u\n",
1403 pid
, minautoport
, maxautoport
);
1404 fprintf(stderr
, "noip(%d): realbind acl:\n", pid
);
1405 dump_acl(bind_real
);
1406 fprintf(stderr
, "noip(%d): realconnect acl:\n", pid
);
1407 dump_acl(connect_real
);
1408 fprintf(stderr
, "noip(%d): impbind list:\n", pid
);
1409 dump_impbind_list(); )
1412 /*----- Overridden system calls -------------------------------------------*/
1414 static void dump_syserr(long rc
)
1415 { fprintf(stderr
, " => %ld (E%d)\n", rc
, errno
); }
1417 static void dump_sysresult(long rc
)
1419 if (rc
< 0) dump_syserr(rc
);
1420 else fprintf(stderr
, " => %ld\n", rc
);
1423 static void dump_addrresult(long rc
, const struct sockaddr
*sa
,
1426 char addrbuf
[ADDRBUFSZ
];
1428 if (rc
< 0) dump_syserr(rc
);
1430 fprintf(stderr
, " => %ld [%s]\n", rc
,
1431 present_sockaddr(sa
, len
, addrbuf
, sizeof(addrbuf
)));
1435 int socket(int pf
, int ty
, int proto
)
1439 D( fprintf(stderr
, "noip(%d): SOCKET pf=%d, type=%d, proto=%d",
1440 getpid(), pf
, ty
, proto
); )
1444 if (!family_known_p(pf
)) {
1445 D( fprintf(stderr
, " -> unknown; refuse\n"); )
1446 errno
= EAFNOSUPPORT
;
1449 D( fprintf(stderr
, " -> inet; substitute"); )
1457 D( fprintf(stderr
, " -> safe; permit"); )
1460 sk
= real_socket(pf
, ty
, proto
);
1461 D( dump_sysresult(sk
); )
1465 int socketpair(int pf
, int ty
, int proto
, int *sk
)
1469 D( fprintf(stderr
, "noip(%d): SOCKETPAIR pf=%d, type=%d, proto=%d",
1470 getpid(), pf
, ty
, proto
); )
1471 if (!family_known_p(pf
))
1472 D( fprintf(stderr
, " -> unknown; permit"); )
1474 D( fprintf(stderr
, " -> inet; substitute"); )
1478 rc
= real_socketpair(pf
, ty
, proto
, sk
);
1479 D( if (rc
< 0) dump_syserr(rc
);
1480 else fprintf(stderr
, " => %d (%d, %d)\n", rc
, sk
[0], sk
[1]); )
1484 int bind(int sk
, const struct sockaddr
*sa
, socklen_t len
)
1486 struct sockaddr_un sun
;
1490 D({ char buf
[ADDRBUFSZ
];
1491 fprintf(stderr
, "noip(%d): BIND sk=%d, sa[%d]=%s", pid
,
1492 sk
, len
, present_sockaddr(sa
, len
, buf
, sizeof(buf
))); })
1494 if (!family_known_p(sa
->sa_family
))
1495 D( fprintf(stderr
, " -> unknown af; pass through"); )
1497 D( fprintf(stderr
, " -> checking...\n"); )
1499 if (acl_allows_p(bind_real
, sa
)) {
1500 if (fixup_real_ip_socket(sk
, sa
->sa_family
, 0))
1503 encode_inet_addr(&sun
, sa
, WANT_FRESH
);
1505 len
= SUN_LEN(&sun
);
1508 D( fprintf(stderr
, "noip(%d): BIND ...", pid
); )
1510 rc
= real_bind(sk
, sa
, len
);
1511 D( dump_sysresult(rc
); )
1515 int connect(int sk
, const struct sockaddr
*sa
, socklen_t len
)
1517 struct sockaddr_un sun
;
1521 D({ char buf
[ADDRBUFSZ
];
1522 fprintf(stderr
, "noip(%d): CONNECT sk=%d, sa[%d]=%s", pid
,
1523 sk
, len
, present_sockaddr(sa
, len
, buf
, sizeof(buf
))); })
1525 if (!family_known_p(sa
->sa_family
)) {
1526 D( fprintf(stderr
, " -> unknown af; pass through"); )
1527 rc
= real_connect(sk
, sa
, len
);
1529 D( fprintf(stderr
, " -> checking...\n"); )
1531 do_implicit_bind(sk
, &sa
, &len
, &sun
);
1533 D( fprintf(stderr
, "noip(%d): CONNECT ...", pid
); )
1534 rc
= real_connect(sk
, sa
, len
);
1537 case ENOENT
: errno
= ECONNREFUSED
; break;
1541 D( dump_sysresult(rc
); )
1545 ssize_t
sendto(int sk
, const void *buf
, size_t len
, int flags
,
1546 const struct sockaddr
*to
, socklen_t tolen
)
1548 struct sockaddr_un sun
;
1552 D({ char addrbuf
[ADDRBUFSZ
];
1553 fprintf(stderr
, "noip(%d): SENDTO sk=%d, len=%lu, flags=%d, to[%d]=%s",
1554 pid
, sk
, (unsigned long)len
, flags
, tolen
,
1555 present_sockaddr(to
, tolen
, addrbuf
, sizeof(addrbuf
))); })
1558 D( fprintf(stderr
, " -> null address; leaving"); )
1559 else if (!family_known_p(to
->sa_family
))
1560 D( fprintf(stderr
, " -> unknown af; pass through"); )
1562 D( fprintf(stderr
, " -> checking...\n"); )
1564 do_implicit_bind(sk
, &to
, &tolen
, &sun
);
1566 D( fprintf(stderr
, "noip(%d): SENDTO ...", pid
); )
1568 n
= real_sendto(sk
, buf
, len
, flags
, to
, tolen
);
1569 D( dump_sysresult(n
); )
1573 ssize_t
recvfrom(int sk
, void *buf
, size_t len
, int flags
,
1574 struct sockaddr
*from
, socklen_t
*fromlen
)
1577 socklen_t mylen
= sizeof(sabuf
);
1581 D( fprintf(stderr
, "noip(%d): RECVFROM sk=%d, len=%lu, flags=%d",
1582 pid
, sk
, (unsigned long)len
, flags
); )
1585 D( fprintf(stderr
, " -> null addr; pass through"); )
1586 n
= real_recvfrom(sk
, buf
, len
, flags
, 0, 0);
1589 n
= real_recvfrom(sk
, buf
, len
, flags
, SA(sabuf
), &mylen
);
1591 D( fprintf(stderr
, " -> converting...\n"); )
1592 return_fake_name(SA(sabuf
), mylen
, from
, fromlen
);
1593 D( fprintf(stderr
, "noip(%d): ... RECVFROM", pid
); )
1597 D( dump_addrresult(n
, from
, fromlen ?
*fromlen
: 0); )
1601 ssize_t
sendmsg(int sk
, const struct msghdr
*msg
, int flags
)
1603 struct sockaddr_un sun
;
1604 const struct sockaddr
*sa
= SA(msg
->msg_name
);
1605 struct msghdr mymsg
;
1609 D({ char addrbuf
[ADDRBUFSZ
];
1610 fprintf(stderr
, "noip(%d): SENDMSG sk=%d, "
1611 "msg_flags=%d, msg_name[%d]=%s, ...",
1612 pid
, sk
, msg
->msg_flags
, msg
->msg_namelen
,
1613 present_sockaddr(sa
, msg
->msg_namelen
,
1614 addrbuf
, sizeof(addrbuf
))); })
1617 D( fprintf(stderr
, " -> null address; leaving"); )
1618 else if (!family_known_p(sa
->sa_family
))
1619 D( fprintf(stderr
, " -> unknown af; pass through"); )
1621 D( fprintf(stderr
, " -> checking...\n"); )
1624 do_implicit_bind(sk
, &sa
, &mymsg
.msg_namelen
, &sun
);
1625 mymsg
.msg_name
= SA(sa
);
1628 D( fprintf(stderr
, "noip(%d): SENDMSG ...", pid
); )
1630 n
= real_sendmsg(sk
, msg
, flags
);
1631 D( dump_sysresult(n
); )
1635 ssize_t
recvmsg(int sk
, struct msghdr
*msg
, int flags
)
1638 struct sockaddr
*sa
= SA(msg
->msg_name
);
1639 socklen_t len
= msg
->msg_namelen
;
1643 D( fprintf(stderr
, "noip(%d): RECVMSG sk=%d msg_flags=%d, ...",
1644 pid
, sk
, msg
->msg_flags
); )
1646 if (!msg
->msg_name
) {
1647 D( fprintf(stderr
, " -> null addr; pass through"); )
1648 return (real_recvmsg(sk
, msg
, flags
));
1651 msg
->msg_name
= sabuf
;
1652 msg
->msg_namelen
= sizeof(sabuf
);
1653 n
= real_recvmsg(sk
, msg
, flags
);
1655 D( fprintf(stderr
, " -> converting...\n"); )
1656 return_fake_name(SA(sabuf
), msg
->msg_namelen
, sa
, &len
);
1657 D( fprintf(stderr
, "noip(%d): ... RECVMSG", pid
); )
1660 msg
->msg_namelen
= len
;
1663 D( dump_addrresult(n
, sa
, len
); )
1667 int accept(int sk
, struct sockaddr
*sa
, socklen_t
*len
)
1670 socklen_t mylen
= sizeof(sabuf
);
1674 D( fprintf(stderr
, "noip(%d): ACCEPT sk=%d", pid
, sk
); )
1676 nsk
= real_accept(sk
, SA(sabuf
), &mylen
);
1677 if (nsk
< 0) /* failed */;
1678 else if (!sa
) D( fprintf(stderr
, " -> address not wanted"); )
1680 D( fprintf(stderr
, " -> converting...\n"); )
1681 return_fake_name(SA(sabuf
), mylen
, sa
, len
);
1682 D( fprintf(stderr
, "noip(%d): ... ACCEPT", pid
); )
1684 D( dump_addrresult(nsk
, sa
, len ?
*len
: 0); )
1688 int getsockname(int sk
, struct sockaddr
*sa
, socklen_t
*len
)
1693 D( fprintf(stderr
, "noip(%d): GETSOCKNAME sk=%d", pid
, sk
); )
1696 socklen_t mylen
= sizeof(sabuf
);
1697 rc
= real_getsockname(sk
, SA(sabuf
), &mylen
);
1699 D( fprintf(stderr
, " -> converting...\n"); )
1700 return_fake_name(SA(sabuf
), mylen
, sa
, len
);
1701 D( fprintf(stderr
, "noip(%d): ... GETSOCKNAME", pid
); )
1704 D( dump_addrresult(rc
, sa
, *len
); )
1708 int getpeername(int sk
, struct sockaddr
*sa
, socklen_t
*len
)
1713 D( fprintf(stderr
, "noip(%d): GETPEERNAME sk=%d", pid
, sk
); )
1716 socklen_t mylen
= sizeof(sabuf
);
1717 rc
= real_getpeername(sk
, SA(sabuf
), &mylen
);
1719 D( fprintf(stderr
, " -> converting...\n"); )
1720 return_fake_name(SA(sabuf
), mylen
, sa
, len
);
1721 D( fprintf(stderr
, "noip(%d): ... GETPEERNAME", pid
); )
1724 D( dump_addrresult(rc
, sa
, *len
); )
1728 int getsockopt(int sk
, int lev
, int opt
, void *p
, socklen_t
*len
)
1738 return (real_getsockopt(sk
, lev
, opt
, p
, len
));
1741 int setsockopt(int sk
, int lev
, int opt
, const void *p
, socklen_t len
)
1750 case SO_BINDTODEVICE
:
1751 case SO_ATTACH_FILTER
:
1752 case SO_DETACH_FILTER
:
1755 return (real_setsockopt(sk
, lev
, opt
, p
, len
));
1758 int ioctl(int fd
, unsigned long op
, ...)
1766 arg
= va_arg(ap
, void *);
1770 case SIOCGIFBRDADDR
:
1771 case SIOCGIFDSTADDR
:
1772 case SIOCGIFNETMASK
:
1774 if (fixup_real_ip_socket(fd
, AF_INET
, &sk
)) goto real
;
1776 rc
= real_ioctl(sk
, op
, arg
);
1777 PRESERVING_ERRNO({ close(sk
); });
1781 rc
= real_ioctl(fd
, op
, arg
);
1788 /*----- Initialization ----------------------------------------------------*/
1790 /* Clean up the socket directory, deleting stale sockets. */
1791 static void cleanup_sockdir(void)
1796 struct sockaddr_un sun
;
1800 if ((dir
= opendir(sockdir
)) == 0) return;
1801 sun
.sun_family
= AF_UNIX
;
1802 while ((d
= readdir(dir
)) != 0) {
1803 if (d
->d_name
[0] == '.') continue;
1804 snprintf(sun
.sun_path
, sizeof(sun
.sun_path
),
1805 "%s/%s", sockdir
, d
->d_name
);
1806 if (decode_inet_addr(&addr
.sa
, 0, &sun
, SUN_LEN(&sun
)) ||
1807 stat(sun
.sun_path
, &st
) ||
1808 !S_ISSOCK(st
.st_mode
)) {
1809 D( fprintf(stderr
, "noip(%d): ignoring unknown socketdir entry `%s'\n",
1810 pid
, sun
.sun_path
); )
1813 if (unix_socket_status(&sun
, 0) == STALE
) {
1814 D( fprintf(stderr
, "noip(%d): clearing away stale socket %s\n",
1816 unlink(sun
.sun_path
);
1822 /* Find the addresses attached to local network interfaces, and remember them
1825 static void get_local_ipaddrs(void)
1827 struct ifaddrs
*ifa_head
, *ifa
;
1832 D( fprintf(stderr
, "noip(%d): fetching local addresses...\n", pid
); )
1833 if (getifaddrs(&ifa_head
)) { perror("getifaddrs"); return; }
1834 for (n_local_ipaddrs
= 0, ifa
= ifa_head
;
1835 n_local_ipaddrs
< MAX_LOCAL_IPADDRS
&& ifa
;
1836 ifa
= ifa
->ifa_next
) {
1837 if (!ifa
->ifa_addr
|| !family_known_p(ifa
->ifa_addr
->sa_family
))
1839 ipaddr_from_sockaddr(&a
, ifa
->ifa_addr
);
1840 D({ char buf
[ADDRBUFSZ
];
1841 fprintf(stderr
, "noip(%d): local addr %s = %s", pid
,
1843 inet_ntop(ifa
->ifa_addr
->sa_family
, &a
,
1844 buf
, sizeof(buf
))); })
1845 for (i
= 0; i
< n_local_ipaddrs
; i
++) {
1846 if (ifa
->ifa_addr
->sa_family
== local_ipaddrs
[i
].af
&&
1847 ipaddr_equal_p(local_ipaddrs
[i
].af
, &a
, &local_ipaddrs
[i
].addr
)) {
1848 D( fprintf(stderr
, " (duplicate)\n"); )
1852 D( fprintf(stderr
, "\n"); )
1853 local_ipaddrs
[n_local_ipaddrs
].af
= ifa
->ifa_addr
->sa_family
;
1854 local_ipaddrs
[n_local_ipaddrs
].addr
= a
;
1858 freeifaddrs(ifa_head
);
1861 /* Print the given message to standard error. Avoids stdio. */
1862 static void printerr(const char *p
)
1863 { if (write(STDERR_FILENO
, p
, strlen(p
))) ; }
1865 /* Create the socket directory, being careful about permissions. */
1866 static void create_sockdir(void)
1870 if (lstat(sockdir
, &st
)) {
1871 if (errno
== ENOENT
) {
1872 if (mkdir(sockdir
, 0700)) {
1873 perror("noip: creating socketdir");
1876 if (!lstat(sockdir
, &st
))
1879 perror("noip: checking socketdir");
1883 if (!S_ISDIR(st
.st_mode
)) {
1884 printerr("noip: bad socketdir: not a directory\n");
1887 if (st
.st_uid
!= uid
) {
1888 printerr("noip: bad socketdir: not owner\n");
1891 if (st
.st_mode
& 077) {
1892 printerr("noip: bad socketdir: not private\n");
1897 /* Initialization function. */
1898 static void setup(void) __attribute__((constructor
));
1899 static void setup(void)
1906 if ((p
= getenv("NOIP_DEBUG")) && atoi(p
))
1908 get_local_ipaddrs();
1915 /*----- That's all, folks -------------------------------------------------*/