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 { DENY
, ALLOW
}; /* ACL verdicts */
65 static int address_families
[] = { AF_INET
, AF_INET6
, -1 };
69 /* Address representations. */
70 typedef union ipaddr
{
75 /* Convenient socket address hacking. */
76 typedef union address
{
78 struct sockaddr_in sin
;
79 struct sockaddr_in6 sin6
;
82 /* Access control list nodes */
83 typedef struct aclnode
{
87 ipaddr minaddr
, maxaddr
;
88 unsigned short minport
, maxport
;
91 /* Implicit bind records */
92 typedef struct impbind
{
95 ipaddr minaddr
, maxaddr
, bindaddr
;
97 enum { EXPLICIT
, SAME
};
99 /* A type for an address range */
100 typedef struct addrrange
{
103 struct { int af
; ipaddr min
, max
; } range
;
106 enum { EMPTY
, ANY
, LOCAL
, RANGE
};
108 /* Local address records */
109 typedef struct full_ipaddr
{
113 #define MAX_LOCAL_IPADDRS 64
114 static full_ipaddr local_ipaddrs
[MAX_LOCAL_IPADDRS
];
115 static int n_local_ipaddrs
;
117 /* General configuration */
119 static char *sockdir
= 0;
120 static int debug
= 0;
121 static unsigned minautoport
= 16384, maxautoport
= 65536;
123 /* Access control lists */
124 static aclnode
*bind_real
, **bind_tail
= &bind_real
;
125 static aclnode
*connect_real
, **connect_tail
= &connect_real
;
126 static impbind
*impbinds
, **impbind_tail
= &impbinds
;
128 /*----- Import the real versions of functions -----------------------------*/
130 /* The list of functions to immport. */
132 _(socket, int, (int, int, int)) \
133 _(socketpair, int, (int, int, int, int *)) \
134 _(connect, int, (int, const struct sockaddr *, socklen_t)) \
135 _(bind, int, (int, const struct sockaddr *, socklen_t)) \
136 _(accept, int, (int, struct sockaddr *, socklen_t *)) \
137 _(getsockname, int, (int, struct sockaddr *, socklen_t *)) \
138 _(getpeername, int, (int, struct sockaddr *, socklen_t *)) \
139 _(getsockopt, int, (int, int, int, void *, socklen_t *)) \
140 _(setsockopt, int, (int, int, int, const void *, socklen_t)) \
141 _(sendto, ssize_t, (int, const void *buf, size_t, int, \
142 const struct sockaddr *to, socklen_t tolen)) \
143 _(recvfrom, ssize_t, (int, void *buf, size_t, int, \
144 struct sockaddr *from, socklen_t *fromlen)) \
145 _(sendmsg, ssize_t, (int, const struct msghdr *, int)) \
146 _(recvmsg, ssize_t, (int, struct msghdr *, int)) \
147 _(ioctl, int, (int, unsigned long, ...))
149 /* Function pointers to set up. */
150 #define DECL(imp, ret, args) static ret (*real_##imp) args;
154 /* Import the system calls. */
155 static void import(void)
157 #define IMPORT(imp, ret, args) \
158 real_##imp = (ret (*)args)dlsym(RTLD_NEXT, #imp);
163 /*----- Utilities ---------------------------------------------------------*/
165 /* Socket address casts */
166 #define SA(sa) ((struct sockaddr *)(sa))
167 #define SIN(sa) ((struct sockaddr_in *)(sa))
168 #define SIN6(sa) ((struct sockaddr_in6 *)(sa))
169 #define SUN(sa) ((struct sockaddr_un *)(sa))
172 #define UC(ch) ((unsigned char)(ch))
174 /* Memory allocation */
175 #define NEW(x) ((x) = xmalloc(sizeof(*x)))
176 #define NEWV(x, n) ((x) = xmalloc(sizeof(*x) * (n)))
180 # define D(body) { if (debug) { body } }
181 # define Dpid pid_t pid = debug ? getpid() : -1
187 /* Preservation of error status */
188 #define PRESERVING_ERRNO(body) do { \
189 int _err = errno; { body } errno = _err; \
192 /* Allocate N bytes of memory; abort on failure. */
193 static void *xmalloc(size_t n
)
197 if ((p
= malloc(n
)) == 0) { perror("malloc"); exit(127); }
201 /* Allocate a copy of the null-terminated string P; abort on failure. */
202 static char *xstrdup(const char *p
)
204 size_t n
= strlen(p
) + 1;
205 char *q
= xmalloc(n
);
210 /*----- Address-type hacking ----------------------------------------------*/
212 /* If M is a simple mask, i.e., consists of a sequence of zero bits followed
213 * by a sequence of one bits, then return the length of the latter sequence
214 * (which may be zero); otherwise return -1.
216 static int simple_mask_length(unsigned long m
)
220 while (m
& 1) { n
++; m
>>= 1; }
224 /* Answer whether AF is an interesting address family. */
225 static int family_known_p(int af
)
236 /* Return the socket address length for address family AF. */
237 static socklen_t
family_socklen(int af
)
240 case AF_INET
: return (sizeof(struct sockaddr_in
));
241 case AF_INET6
: return (sizeof(struct sockaddr_in6
));
246 /* Return the width of addresses of kind AF. */
247 static int address_width(int af
)
250 case AF_INET
: return 32;
251 case AF_INET6
: return 128;
256 /* If addresses A and B share a common prefix then return its length;
257 * otherwise return -1.
259 static int common_prefix_length(int af
, const ipaddr
*a
, const ipaddr
*b
)
263 unsigned long aa
= ntohl(a
->v4
.s_addr
), bb
= ntohl(b
->v4
.s_addr
);
264 unsigned long m
= aa
^bb
;
265 if ((aa
&m
) == 0 && (bb
&m
) == m
) return (32 - simple_mask_length(m
));
269 const uint8_t *aa
= a
->v6
.s6_addr
, *bb
= b
->v6
.s6_addr
;
274 for (i
= 0; i
< 16 && aa
[i
] == bb
[i
]; i
++);
278 if ((aa
[i
]&m
) != 0 || (bb
[i
]&m
) != m
) return (-1);
279 n
+= 8 - simple_mask_length(m
);
280 for (i
++; i
< 16; i
++)
281 if (aa
[i
] || bb
[i
] != 0xff) return (-1);
290 /* Extract the port number (in host byte-order) from SA. */
291 static int port_from_sockaddr(const struct sockaddr
*sa
)
293 switch (sa
->sa_family
) {
294 case AF_INET
: return (ntohs(SIN(sa
)->sin_port
));
295 case AF_INET6
: return (ntohs(SIN6(sa
)->sin6_port
));
300 /* Store the port number PORT (in host byte-order) in SA. */
301 static void port_to_sockaddr(struct sockaddr
*sa
, int port
)
303 switch (sa
->sa_family
) {
304 case AF_INET
: SIN(sa
)->sin_port
= htons(port
); break;
305 case AF_INET6
: SIN6(sa
)->sin6_port
= htons(port
); break;
310 /* Extract the address part from SA and store it in A. */
311 static void ipaddr_from_sockaddr(ipaddr
*a
, const struct sockaddr
*sa
)
313 switch (sa
->sa_family
) {
314 case AF_INET
: a
->v4
= SIN(sa
)->sin_addr
; break;
315 case AF_INET6
: a
->v6
= SIN6(sa
)->sin6_addr
; break;
320 /* Store the address A in SA. */
321 static void ipaddr_to_sockaddr(struct sockaddr
*sa
, const ipaddr
*a
)
323 switch (sa
->sa_family
) {
325 SIN(sa
)->sin_addr
= a
->v4
;
328 SIN6(sa
)->sin6_addr
= a
->v6
;
329 SIN6(sa
)->sin6_scope_id
= 0;
330 SIN6(sa
)->sin6_flowinfo
= 0;
337 /* Copy a whole socket address about. */
338 static void copy_sockaddr(struct sockaddr
*sa_dst
,
339 const struct sockaddr
*sa_src
)
340 { memcpy(sa_dst
, sa_src
, family_socklen(sa_src
->sa_family
)); }
342 /* Answer whether two addresses are equal. */
343 static int ipaddr_equal_p(int af
, const ipaddr
*a
, const ipaddr
*b
)
346 case AF_INET
: return (a
->v4
.s_addr
== b
->v4
.s_addr
);
347 case AF_INET6
: return (memcmp(a
->v6
.s6_addr
, b
->v6
.s6_addr
, 16) == 0);
352 /* Answer whether the address part of SA is between A and B (inclusive). We
353 * assume that SA has the correct address family.
355 static int sockaddr_in_range_p(const struct sockaddr
*sa
,
356 const ipaddr
*a
, const ipaddr
*b
)
358 switch (sa
->sa_family
) {
360 unsigned long addr
= ntohl(SIN(sa
)->sin_addr
.s_addr
);
361 return (ntohl(a
->v4
.s_addr
) <= addr
&&
362 addr
<= ntohl(b
->v4
.s_addr
));
365 const uint8_t *ss
= SIN6(sa
)->sin6_addr
.s6_addr
;
366 const uint8_t *aa
= a
->v6
.s6_addr
, *bb
= b
->v6
.s6_addr
;
370 for (i
= 0; h
&& l
&& i
< 16; i
++, ss
++, aa
++, bb
++) {
371 if (*ss
< *aa
|| *bb
< *ss
) return (0);
372 if (*aa
< *ss
) l
= 0;
373 if (*ss
< *bb
) h
= 0;
382 /* Fill in SA with the appropriate wildcard address. */
383 static void wildcard_address(int af
, struct sockaddr
*sa
)
387 struct sockaddr_in
*sin
= SIN(sa
);
388 memset(sin
, 0, sizeof(*sin
));
389 sin
->sin_family
= AF_INET
;
391 sin
->sin_addr
.s_addr
= INADDR_ANY
;
394 struct sockaddr_in6
*sin6
= SIN6(sa
);
395 memset(sin6
, 0, sizeof(*sin6
));
396 sin6
->sin6_family
= AF_INET6
;
398 sin6
->sin6_addr
= in6addr_any
;
399 sin6
->sin6_scope_id
= 0;
400 sin6
->sin6_flowinfo
= 0;
407 /* Mask the address A, forcing all but the top PLEN bits to zero or one
408 * according to HIGHP.
410 static void mask_address(int af
, ipaddr
*a
, int plen
, int highp
)
414 unsigned long addr
= ntohl(a
->v4
.s_addr
);
415 unsigned long mask
= plen ?
~0ul << (32 - plen
) : 0;
417 if (highp
) addr
|= ~mask
;
418 a
->v4
.s_addr
= htonl(addr
& 0xffffffff);
422 unsigned m
= (0xff << (8 - plen
%8)) & 0xff;
423 unsigned s
= highp ?
0xff : 0;
425 a
->v6
.s6_addr
[i
] = (a
->v6
.s6_addr
[i
] & m
) | (s
& ~m
);
428 for (; i
< 16; i
++) a
->v6
.s6_addr
[i
] = s
;
435 /* Write a presentation form of SA to BUF, a buffer of length SZ. LEN is the
436 * address length; if it's zero, look it up based on the address family.
437 * Return a pointer to the string (which might, in an emergency, be a static
438 * string rather than your buffer).
440 static char *present_sockaddr(const struct sockaddr
*sa
, socklen_t len
,
441 char *buf
, size_t sz
)
443 #define WANT(n_) do { if (sz < (n_)) goto nospace; } while (0)
444 #define PUTC(c_) do { *buf++ = (c_); sz--; } while (0)
446 if (!sa
) return "<null-address>";
447 if (!sz
) return "<no-space-in-buffer>";
448 if (!len
) len
= family_socklen(sa
->sa_family
);
450 switch (sa
->sa_family
) {
452 struct sockaddr_un
*sun
= SUN(sa
);
453 char *p
= sun
->sun_path
;
454 size_t n
= len
- offsetof(struct sockaddr_un
, sun_path
);
462 case 0: WANT(2); PUTC('\\'); PUTC('0'); break;
463 case '\a': WANT(2); PUTC('\\'); PUTC('a'); break;
464 case '\n': WANT(2); PUTC('\\'); PUTC('n'); break;
465 case '\r': WANT(2); PUTC('\\'); PUTC('r'); break;
466 case '\t': WANT(2); PUTC('\\'); PUTC('t'); break;
467 case '\v': WANT(2); PUTC('\\'); PUTC('v'); break;
468 case '\\': WANT(2); PUTC('\\'); PUTC('\\'); break;
470 if (*p
> ' ' && *p
<= '~')
471 { WANT(1); PUTC(*p
); }
473 WANT(4); PUTC('\\'); PUTC('x');
474 PUTC((*p
>> 4)&0xf); PUTC((*p
>> 0)&0xf);
481 if (*p
!= '/') { WANT(2); PUTC('.'); PUTC('/'); }
482 while (n
&& *p
) { WANT(1); PUTC(*p
); p
++; n
--; }
486 case AF_INET
: case AF_INET6
: {
487 char addrbuf
[NI_MAXHOST
], portbuf
[NI_MAXSERV
];
488 int err
= getnameinfo(sa
, len
,
489 addrbuf
, sizeof(addrbuf
),
490 portbuf
, sizeof(portbuf
),
491 NI_NUMERICHOST
| NI_NUMERICSERV
);
493 snprintf(buf
, sz
, strchr(addrbuf
, ':') ?
"[%s]:%s" : "%s:%s",
497 snprintf(buf
, sz
, "<unknown-address-family %d>", sa
->sa_family
);
507 /* Guess the family of a textual socket address. */
508 static int guess_address_family(const char *p
)
509 { return (strchr(p
, ':') ? AF_INET6
: AF_INET
); }
511 /* Parse a socket address P and write the result to SA. */
512 static int parse_sockaddr(struct sockaddr
*sa
, const char *p
)
516 struct addrinfo
*ai
, ai_hint
= { 0 };
518 if (strlen(p
) >= sizeof(buf
) - 1) return (-1);
519 strcpy(buf
, p
); p
= buf
;
521 if ((q
= strchr(p
, ':')) == 0) return (-1);
525 if ((q
= strchr(p
, ']')) == 0) return (-1);
527 if (*q
!= ':') return (-1);
531 ai_hint
.ai_family
= AF_UNSPEC
;
532 ai_hint
.ai_socktype
= SOCK_DGRAM
;
533 ai_hint
.ai_flags
= AI_NUMERICHOST
| AI_NUMERICSERV
;
534 if (getaddrinfo(p
, q
, &ai_hint
, &ai
)) return (-1);
535 memcpy(sa
, ai
->ai_addr
, ai
->ai_addrlen
);
540 /*----- Access control lists ----------------------------------------------*/
544 static void dump_addrrange(int af
, const ipaddr
*min
, const ipaddr
*max
)
550 plen
= common_prefix_length(af
, min
, max
);
551 p
= inet_ntop(af
, min
, buf
, sizeof(buf
));
552 fprintf(stderr
, strchr(p
, ':') ?
"[%s]" : "%s", p
);
554 p
= inet_ntop(af
, &max
, buf
, sizeof(buf
));
555 fprintf(stderr
, strchr(p
, ':') ?
"-[%s]" : "-%s", p
);
556 } else if (plen
< address_width(af
))
557 fprintf(stderr
, "/%d", plen
);
560 /* Write to standard error a description of the ACL node A. */
561 static void dump_aclnode(const aclnode
*a
)
563 fprintf(stderr
, "noip(%d): %c ", getpid(), a
->act ?
'+' : '-');
564 dump_addrrange(a
->af
, &a
->minaddr
, &a
->maxaddr
);
565 if (a
->minport
!= 0 || a
->maxport
!= 0xffff) {
566 fprintf(stderr
, ":%u", (unsigned)a
->minport
);
567 if (a
->minport
!= a
->maxport
)
568 fprintf(stderr
, "-%u", (unsigned)a
->maxport
);
573 static void dump_acl(const aclnode
*a
)
577 for (; a
; a
= a
->next
) {
581 fprintf(stderr
, "noip(%d): [default policy: %s]\n", getpid(),
582 act
== ALLOW ?
"DENY" : "ALLOW");
587 /* Returns nonzero if the ACL A allows the socket address SA. */
588 static int acl_allows_p(const aclnode
*a
, const struct sockaddr
*sa
)
590 unsigned short port
= port_from_sockaddr(sa
);
594 D({ char buf
[ADDRBUFSZ
];
595 fprintf(stderr
, "noip(%d): check %s\n", pid
,
596 present_sockaddr(sa
, 0, buf
, sizeof(buf
))); })
597 for (; a
; a
= a
->next
) {
598 D( dump_aclnode(a
); )
599 if (a
->af
== sa
->sa_family
&&
600 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 we can't find the socket node, then it's definitely not in use. If
645 * we get some other error, then this socket is weird.
647 if (stat(sun
->sun_path
, &st
))
648 return (errno
== ENOENT ? UNUSED
: USED
);
650 /* If it's not a socket, then something weird is going on. If we're just
651 * probing quickly to find a spare port, then existence is sufficient to
654 if (!S_ISSOCK(st
.st_mode
) || quickp
)
657 /* The socket's definitely there, but is anyone actually still holding it
658 * open? The only way I know to discover this is to trundle through
659 * `/proc/net/unix'. If there's no entry, then the socket must be stale.
662 if ((fp
= fopen("/proc/net/unix", "r")) == 0)
664 if (!fgets(buf
, sizeof(buf
), fp
)) goto done
; /* skip header */
665 len
= strlen(sun
->sun_path
);
666 while (fgets(buf
, sizeof(buf
), fp
)) {
668 if (n
>= len
+ 2 && buf
[n
- len
- 2] == ' ' && buf
[n
- 1] == '\n' &&
669 memcmp(buf
+ n
- len
- 1, sun
->sun_path
, len
) == 0)
682 /* Encode SA as a Unix-domain address SUN, and return whether it's currently
685 static int encode_single_inet_addr(const struct sockaddr
*sa
,
686 struct sockaddr_un
*sun
,
692 snprintf(sun
->sun_path
, sizeof(sun
->sun_path
), "%s/%s", sockdir
,
693 present_sockaddr(sa
, 0, buf
, sizeof(buf
)));
694 if ((rc
= unix_socket_status(sun
, quickp
)) == USED
) return (USED
);
695 else if (rc
== STALE
) unlink(sun
->sun_path
);
699 /* Convert the IP address SA to a Unix-domain address SUN. Fail if the
700 * address seems already taken. If DESPARATEP then try cleaning up stale old
703 static int encode_unused_inet_addr(struct sockaddr
*sa
,
704 struct sockaddr_un
*sun
,
708 struct sockaddr_un wsun
;
709 int port
= port_from_sockaddr(sa
);
711 /* First, look for an exact match. Only look quickly unless we're
712 * desperate. If the socket is in use, we fail here. (This could get
713 * racy. Let's not worry about that for now.)
715 if (encode_single_inet_addr(sa
, sun
, !desperatep
) == USED
)
718 /* Next, check the corresponding wildcard address, so as to avoid
719 * inadvertant collisions with listeners. Do this in the same way.
721 wildcard_address(sa
->sa_family
, &waddr
.sa
);
722 port_to_sockaddr(&waddr
.sa
, port
);
723 if (encode_single_inet_addr(&waddr
.sa
, &wsun
, !desperatep
) == USED
)
730 /* Encode the Internet address SA as a Unix-domain address SUN. If the flag
731 * `ENCF_FRESH' is set, and SA's port number is zero, then we pick an
732 * arbitrary local port. Otherwise we pick the port given. There's an
733 * unpleasant hack to find servers bound to local wildcard addresses.
734 * Returns zero on success; -1 on failure.
736 #define ENCF_FRESH 1u
737 static int encode_inet_addr(struct sockaddr_un
*sun
,
738 const struct sockaddr
*sa
,
744 int port
= port_from_sockaddr(sa
);
747 D( fprintf(stderr
, "noip(%d): encode %s (%s)", getpid(),
748 present_sockaddr(sa
, 0, buf
, sizeof(buf
)),
749 (f
&ENCF_FRESH
) ?
"FRESH" : "EXISTING"); )
751 /* Start making the Unix-domain address. */
752 sun
->sun_family
= AF_UNIX
;
754 if (port
|| !(f
&ENCF_FRESH
)) {
756 /* Try the address as given. If it's in use, or we don't necessarily
757 * want an existing socket, then we're done.
759 if (encode_single_inet_addr(sa
, sun
, 0) == USED
|| (f
&ENCF_FRESH
))
762 /* We're looking for a socket which already exists. Try the
763 * corresponding wildcard address.
765 wildcard_address(sa
->sa_family
, &addr
.sa
);
766 port_to_sockaddr(&addr
.sa
, port
);
767 encode_single_inet_addr(&addr
.sa
, sun
, 0);
770 /* We want a fresh new socket. */
772 /* Make a copy of the given address, because we're going to mangle it. */
773 copy_sockaddr(&addr
.sa
, sa
);
775 /* Try a few random-ish port numbers to see if any of them is spare. */
776 for (i
= 0; i
< 10; i
++) {
777 port_to_sockaddr(&addr
.sa
, randrange(minautoport
, maxautoport
));
778 if (!encode_unused_inet_addr(&addr
.sa
, sun
, 0)) goto found
;
781 /* Things must be getting tight. Work through all of the autoport range
782 * to see if we can find a spare one. The first time, just do it the
783 * quick way; if that doesn't work, then check harder for stale sockets.
785 for (desperatep
= 0; desperatep
< 2; desperatep
++) {
786 for (i
= minautoport
; i
<= maxautoport
; i
++) {
787 port_to_sockaddr(&addr
.sa
, i
);
788 if (!encode_unused_inet_addr(&addr
.sa
, sun
, 0)) goto found
;
792 /* We failed to find any free ports. */
794 D( fprintf(stderr
, " -- can't resolve\n"); )
800 D( fprintf(stderr
, " -> `%s'\n", sun
->sun_path
); )
804 /* Decode the Unix address SUN to an Internet address SIN. If AF_HINT is
805 * nonzero, an empty address (indicative of an unbound Unix-domain socket) is
806 * translated to a wildcard Internet address of the appropriate family.
807 * Returns zero on success; -1 on failure (e.g., it wasn't one of our
810 static int decode_inet_addr(struct sockaddr
*sa
, int af_hint
,
811 const struct sockaddr_un
*sun
,
815 size_t n
= strlen(sockdir
), nn
;
818 if (!sa
) sa
= &addr
.sa
;
819 if (sun
->sun_family
!= AF_UNIX
) return (-1);
820 if (len
> sizeof(*sun
)) return (-1);
821 ((char *)sun
)[len
] = 0;
822 nn
= strlen(sun
->sun_path
);
823 D( fprintf(stderr
, "noip(%d): decode `%s'", getpid(), sun
->sun_path
); )
824 if (af_hint
&& !sun
->sun_path
[0]) {
825 wildcard_address(af_hint
, sa
);
826 D( fprintf(stderr
, " -- unbound socket\n"); )
829 if (nn
< n
+ 1 || nn
- n
>= sizeof(buf
) || sun
->sun_path
[n
] != '/' ||
830 memcmp(sun
->sun_path
, sockdir
, n
) != 0) {
831 D( fprintf(stderr
, " -- not one of ours\n"); )
834 if (parse_sockaddr(sa
, sun
->sun_path
+ n
+ 1)) return (-1);
835 D( fprintf(stderr
, " -> %s\n",
836 present_sockaddr(sa
, 0, buf
, sizeof(buf
))); )
840 /* SK is (or at least might be) a Unix-domain socket we created when an
841 * Internet socket was asked for. We've decided it should be an Internet
842 * socket after all, with family AF_HINT, so convert it. If TMP is not null,
843 * then don't replace the existing descriptor: store the new socket in *TMP
846 static int fixup_real_ip_socket(int sk
, int af_hint
, int *tmp
)
851 struct sockaddr_un sun
;
864 _(LINGER, struct linger) \
867 _(RCVTIMEO, struct timeval) \
868 _(SNDTIMEO, struct timeval)
871 if (real_getsockname(sk
, SA(&sun
), &len
))
873 if (decode_inet_addr(&addr
.sa
, af_hint
, &sun
, len
))
874 return (0); /* Not one of ours */
876 if (real_getsockopt(sk
, SOL_SOCKET
, SO_TYPE
, &type
, &len
) < 0 ||
877 (nsk
= real_socket(addr
.sa
.sa_family
, type
, 0)) < 0)
879 #define FIX(opt, ty) do { \
882 if (real_getsockopt(sk, SOL_SOCKET, SO_##opt, &ov_, &len) < 0 || \
883 real_setsockopt(nsk, SOL_SOCKET, SO_##opt, &ov_, len)) { \
893 if ((f
= fcntl(sk
, F_GETFL
)) < 0 ||
894 (fd
= fcntl(sk
, F_GETFD
)) < 0 ||
895 fcntl(nsk
, F_SETFL
, f
) < 0 ||
900 unlink(sun
.sun_path
);
902 if (fcntl(sk
, F_SETFD
, fd
) < 0) {
903 perror("noip: fixup_real_ip_socket F_SETFD");
910 /* We found the real address SA, with length LEN; if it's a Unix-domain
911 * address corresponding to a fake socket, convert it to cover up the
912 * deception. Whatever happens, put the result at FAKE and store its length
915 static void return_fake_name(struct sockaddr
*sa
, socklen_t len
,
916 struct sockaddr
*fake
, socklen_t
*fakelen
)
921 if (sa
->sa_family
== AF_UNIX
&&
922 !decode_inet_addr(&addr
.sa
, 0, SUN(sa
), len
)) {
924 len
= family_socklen(addr
.sa
.sa_family
);
927 if (len
> *fakelen
) len
= *fakelen
;
928 if (len
> 0) memcpy(fake
, sa
, len
);
932 /*----- Implicit binding --------------------------------------------------*/
936 static void dump_impbind(const impbind
*i
)
940 fprintf(stderr
, "noip(%d): ", getpid());
941 dump_addrrange(i
->af
, &i
->minaddr
, &i
->maxaddr
);
943 case SAME
: fprintf(stderr
, " <self>"); break;
945 fprintf(stderr
, " %s", inet_ntop(i
->af
, &i
->bindaddr
,
953 static void dump_impbind_list(void)
957 for (i
= impbinds
; i
; i
= i
->next
) dump_impbind(i
);
962 /* The socket SK is about to be used to communicate with the remote address
963 * SA. Assign it a local address so that getpeername(2) does something
966 static int do_implicit_bind(int sk
, const struct sockaddr
*sa
)
969 struct sockaddr_un sun
;
973 D( fprintf(stderr
, "noip(%d): checking impbind list...\n", pid
); )
974 for (i
= impbinds
; i
; i
= i
->next
) {
975 D( dump_impbind(i
); )
976 if (sa
->sa_family
== i
->af
&&
977 sockaddr_in_range_p(sa
, &i
->minaddr
, &i
->maxaddr
)) {
978 D( fprintf(stderr
, "noip(%d): match!\n", pid
); )
979 addr
.sa
.sa_family
= sa
->sa_family
;
980 ipaddr_to_sockaddr(&addr
.sa
, &i
->bindaddr
);
984 D( fprintf(stderr
, "noip(%d): no match; using wildcard\n", pid
); )
985 wildcard_address(sa
->sa_family
, &addr
.sa
);
987 encode_inet_addr(&sun
, &addr
.sa
, ENCF_FRESH
);
988 if (real_bind(sk
, SA(&sun
), SUN_LEN(&sun
))) return (-1);
992 /* The socket SK is about to communicate with the remote address *SA. Ensure
993 * that the socket has a local address, and adjust *SA to refer to the real
996 * If we need to translate the remote address, then the Unix-domain endpoint
997 * address will end in *SUN, and *SA will be adjusted to point to it.
999 static int fixup_client_socket(int sk
, const struct sockaddr
**sa_r
,
1000 socklen_t
*len_r
, struct sockaddr_un
*sun
)
1002 socklen_t mylen
= sizeof(*sun
);
1003 const struct sockaddr
*sa
= *sa_r
;
1005 /* If we're allowed to talk to a real remote endpoint, then fix things up
1006 * as necessary and proceed.
1008 if (acl_allows_p(connect_real
, sa
)) {
1009 if (fixup_real_ip_socket(sk
, (*sa_r
)->sa_family
, 0)) return (-1);
1013 /* If this isn't a Unix-domain socket then there's nothing to do. */
1014 if (real_getsockname(sk
, SA(sun
), &mylen
) < 0) return (-1);
1015 if (sun
->sun_family
!= AF_UNIX
) return (0);
1016 if (mylen
< sizeof(*sun
)) ((char *)sun
)[mylen
] = 0;
1018 /* Speaking of which, if we don't have a local address, then we should
1021 if (!sun
->sun_path
[0] && do_implicit_bind(sk
, sa
)) return (-1);
1023 /* And then come up with a remote address. */
1024 encode_inet_addr(sun
, sa
, 0);
1026 *len_r
= SUN_LEN(sun
);
1030 /*----- Configuration -----------------------------------------------------*/
1032 /* Return the process owner's home directory. */
1033 static char *home(void)
1038 if (getuid() == uid
&&
1039 (p
= getenv("HOME")) != 0)
1041 else if ((pw
= getpwuid(uid
)) != 0)
1042 return (pw
->pw_dir
);
1047 /* Return a good temporary directory to use. */
1048 static char *tmpdir(void)
1052 if ((p
= getenv("TMPDIR")) != 0) return (p
);
1053 else if ((p
= getenv("TMP")) != 0) return (p
);
1054 else return ("/tmp");
1057 /* Return the user's name, or at least something distinctive. */
1058 static char *user(void)
1060 static char buf
[16];
1064 if ((p
= getenv("USER")) != 0) return (p
);
1065 else if ((p
= getenv("LOGNAME")) != 0) return (p
);
1066 else if ((pw
= getpwuid(uid
)) != 0) return (pw
->pw_name
);
1068 snprintf(buf
, sizeof(buf
), "uid-%lu", (unsigned long)uid
);
1073 /* Skip P over space characters. */
1074 #define SKIPSPC do { while (*p && isspace(UC(*p))) p++; } while (0)
1076 /* Set Q to point to the next word following P, null-terminate it, and step P
1078 #define NEXTWORD(q) do { \
1081 while (*p && !isspace(UC(*p))) p++; \
1085 /* Set Q to point to the next dotted-quad address, store the ending delimiter
1086 * in DEL, null-terminate it, and step P past it. */
1087 static void parse_nextaddr(char **pp
, char **qq
, int *del
)
1095 p
+= strcspn(p
, "]");
1100 while (*p
&& (*p
== '.' || isdigit(UC(*p
)))) p
++;
1107 /* Set Q to point to the next decimal number, store the ending delimiter in
1108 * DEL, null-terminate it, and step P past it. */
1109 #define NEXTNUMBER(q, del) do { \
1112 while (*p && isdigit(UC(*p))) p++; \
1117 /* Push the character DEL back so we scan it again, unless it's zero
1119 #define RESCAN(del) do { if (del) *--p = del; } while (0)
1121 /* Evaluate true if P is pointing to the word KW (and not some longer string
1122 * of which KW is a prefix). */
1124 #define KWMATCHP(kw) (strncmp(p, kw, sizeof(kw) - 1) == 0 && \
1125 !isalnum(UC(p[sizeof(kw) - 1])) && \
1126 (p += sizeof(kw) - 1))
1128 /* Parse a port list, starting at *PP. Port lists have the form
1129 * [:LOW[-HIGH]]: if omitted, all ports are included; if HIGH is omitted,
1130 * it's as if HIGH = LOW. Store LOW in *MIN, HIGH in *MAX and set *PP to the
1131 * rest of the string.
1133 static void parse_ports(char **pp
, unsigned short *min
, unsigned short *max
)
1140 { *min
= 0; *max
= 0xffff; }
1143 NEXTNUMBER(q
, del
); *min
= strtoul(q
, 0, 0); RESCAN(del
);
1146 { p
++; NEXTNUMBER(q
, del
); *max
= strtoul(q
, 0, 0); RESCAN(del
); }
1153 /* Parse an address range designator starting at PP and store a
1154 * representation of it in R. An address range designator has the form:
1156 * any | local | ADDR | ADDR - ADDR | ADDR/ADDR | ADDR/INT
1158 static int parse_addrrange(char **pp
, addrrange
*r
)
1166 if (KWMATCHP("any")) r
->type
= ANY
;
1167 else if (KWMATCHP("local")) r
->type
= LOCAL
;
1169 parse_nextaddr(&p
, &q
, &del
);
1170 af
= guess_address_family(q
);
1171 if (inet_pton(af
, q
, &r
->u
.range
.min
) <= 0) goto bad
;
1176 parse_nextaddr(&p
, &q
, &del
);
1177 if (inet_pton(af
, q
, &r
->u
.range
.max
) <= 0) goto bad
;
1179 } else if (*p
== '/') {
1182 n
= strtoul(q
, 0, 0);
1183 r
->u
.range
.max
= r
->u
.range
.min
;
1184 mask_address(af
, &r
->u
.range
.min
, n
, 0);
1185 mask_address(af
, &r
->u
.range
.max
, n
, 1);
1188 r
->u
.range
.max
= r
->u
.range
.min
;
1199 /* Call FUNC on each individual address range in R. */
1200 static void foreach_addrrange(const addrrange
*r
,
1201 void (*func
)(int af
,
1207 ipaddr minaddr
, maxaddr
;
1214 for (i
= 0; address_families
[i
] >= 0; i
++) {
1215 af
= address_families
[i
];
1216 memset(&minaddr
, 0, sizeof(minaddr
));
1217 maxaddr
= minaddr
; mask_address(af
, &maxaddr
, 0, 1);
1218 func(af
, &minaddr
, &maxaddr
, p
);
1222 for (i
= 0; address_families
[i
] >= 0; i
++) {
1223 af
= address_families
[i
];
1224 memset(&minaddr
, 0, sizeof(minaddr
));
1225 maxaddr
= minaddr
; mask_address(af
, &maxaddr
, 0, 1);
1226 func(af
, &minaddr
, &minaddr
, p
);
1227 func(af
, &maxaddr
, &maxaddr
, p
);
1229 for (i
= 0; i
< n_local_ipaddrs
; i
++) {
1230 func(local_ipaddrs
[i
].af
,
1231 &local_ipaddrs
[i
].addr
, &local_ipaddrs
[i
].addr
,
1236 func(r
->u
.range
.af
, &r
->u
.range
.min
, &r
->u
.range
.max
, p
);
1243 struct add_aclnode_ctx
{
1245 unsigned short minport
, maxport
;
1249 static void add_aclnode(int af
, const ipaddr
*min
, const ipaddr
*max
,
1252 struct add_aclnode_ctx
*ctx
= p
;
1258 a
->minaddr
= *min
; a
->maxaddr
= *max
;
1259 a
->minport
= ctx
->minport
; a
->maxport
= ctx
->maxport
;
1260 **ctx
->tail
= a
; *ctx
->tail
= &a
->next
;
1263 /* Parse an ACL line. *PP points to the end of the line; *TAIL points to
1264 * the list tail (i.e., the final link in the list). An ACL entry has the
1265 * form +|- ADDR-RANGE PORTS
1266 * where PORTS is parsed by parse_ports above; an ACL line consists of a
1267 * comma-separated sequence of entries..
1269 static void parse_acl_line(char **pp
, aclnode
***tail
)
1271 struct add_aclnode_ctx ctx
;
1278 if (*p
== '+') ctx
.act
= ALLOW
;
1279 else if (*p
== '-') ctx
.act
= DENY
;
1283 if (parse_addrrange(&p
, &r
)) goto bad
;
1284 parse_ports(&p
, &ctx
.minport
, &ctx
.maxport
);
1285 foreach_addrrange(&r
, add_aclnode
, &ctx
);
1287 if (*p
!= ',') break;
1295 D( fprintf(stderr
, "noip(%d): bad acl spec (ignored)\n", getpid()); )
1299 /* Parse an ACL from an environment variable VAR, attaching it to the list
1302 static void parse_acl_env(const char *var
, aclnode
***tail
)
1306 if ((p
= getenv(var
)) != 0) {
1308 parse_acl_line(&q
, tail
);
1313 struct add_impbind_ctx
{
1318 static void add_impbind(int af
, const ipaddr
*min
, const ipaddr
*max
,
1321 struct add_impbind_ctx
*ctx
= p
;
1324 if (ctx
->af
&& af
!= ctx
->af
) return;
1328 i
->minaddr
= *min
; i
->maxaddr
= *max
;
1330 case EXPLICIT
: i
->bindaddr
= ctx
->addr
;
1334 *impbind_tail
= i
; impbind_tail
= &i
->next
;
1337 /* Parse an implicit-bind line. An implicit-bind entry has the form
1338 * ADDR-RANGE {ADDR | same}
1340 static void parse_impbind_line(char **pp
)
1342 struct add_impbind_ctx ctx
;
1348 if (parse_addrrange(&p
, &r
)) goto bad
;
1350 if (KWMATCHP("same")) {
1355 parse_nextaddr(&p
, &q
, &del
);
1356 ctx
.af
= guess_address_family(q
);
1357 if (inet_pton(ctx
.af
, q
, &ctx
.addr
) < 0) goto bad
;
1360 foreach_addrrange(&r
, add_impbind
, &ctx
);
1362 if (*p
!= ',') break;
1370 D( fprintf(stderr
, "noip(%d): bad implicit-bind spec (ignored)\n",
1375 /* Parse implicit-bind instructions from an environment variable VAR,
1376 * attaching it to the list.
1378 static void parse_impbind_env(const char *var
)
1382 if ((p
= getenv(var
)) != 0) {
1384 parse_impbind_line(&q
);
1389 /* Parse the autoports configuration directive. Syntax is MIN - MAX. */
1390 static void parse_autoports(char **pp
)
1397 NEXTNUMBER(q
, del
); x
= strtoul(q
, 0, 0); RESCAN(del
);
1399 if (*p
!= '-') goto bad
;
1401 NEXTNUMBER(q
, del
); y
= strtoul(q
, 0, 0); RESCAN(del
);
1402 minautoport
= x
; maxautoport
= y
;
1403 SKIPSPC
; if (*p
) goto bad
;
1408 D( fprintf(stderr
, "noip(%d): bad port range (ignored)\n", getpid()); )
1412 /* Read the configuration from the config file and environment. */
1413 static void readconfig(void)
1421 parse_acl_env("NOIP_REALBIND_BEFORE", &bind_tail
);
1422 parse_acl_env("NOIP_REALCONNECT_BEFORE", &connect_tail
);
1423 parse_impbind_env("NOIP_IMPBIND_BEFORE");
1424 if ((p
= getenv("NOIP_AUTOPORTS")) != 0) {
1426 parse_autoports(&q
);
1429 if ((p
= getenv("NOIP_CONFIG")) == 0)
1430 snprintf(p
= buf
, sizeof(buf
), "%s/.noip", home());
1431 D( fprintf(stderr
, "noip(%d): config file: %s\n", pid
, p
); )
1433 if ((fp
= fopen(p
, "r")) == 0) {
1434 D( fprintf(stderr
, "noip(%d): couldn't read config: %s\n",
1435 pid
, strerror(errno
)); )
1438 while (fgets(buf
, sizeof(buf
), fp
)) {
1443 if (!*p
|| *p
== '#') continue;
1444 while (n
&& isspace(UC(buf
[n
- 1]))) n
--;
1449 if (strcmp(cmd
, "socketdir") == 0)
1450 sockdir
= xstrdup(p
);
1451 else if (strcmp(cmd
, "realbind") == 0)
1452 parse_acl_line(&p
, &bind_tail
);
1453 else if (strcmp(cmd
, "realconnect") == 0)
1454 parse_acl_line(&p
, &connect_tail
);
1455 else if (strcmp(cmd
, "impbind") == 0)
1456 parse_impbind_line(&p
);
1457 else if (strcmp(cmd
, "autoports") == 0)
1458 parse_autoports(&p
);
1459 else if (strcmp(cmd
, "debug") == 0)
1460 debug
= *p ?
atoi(p
) : 1;
1462 D( fprintf(stderr
, "noip(%d): bad config command %s\n", pid
, cmd
); )
1467 parse_acl_env("NOIP_REALBIND", &bind_tail
);
1468 parse_acl_env("NOIP_REALCONNECT", &connect_tail
);
1469 parse_impbind_env("NOIP_IMPBIND");
1470 parse_acl_env("NOIP_REALBIND_AFTER", &bind_tail
);
1471 parse_acl_env("NOIP_REALCONNECT_AFTER", &connect_tail
);
1472 parse_impbind_env("NOIP_IMPBIND_AFTER");
1476 if (!sockdir
) sockdir
= getenv("NOIP_SOCKETDIR");
1478 snprintf(buf
, sizeof(buf
), "%s/noip-%s", tmpdir(), user());
1479 sockdir
= xstrdup(buf
);
1481 D( fprintf(stderr
, "noip(%d): socketdir: %s\n", pid
, sockdir
);
1482 fprintf(stderr
, "noip(%d): autoports: %u-%u\n",
1483 pid
, minautoport
, maxautoport
);
1484 fprintf(stderr
, "noip(%d): realbind acl:\n", pid
);
1485 dump_acl(bind_real
);
1486 fprintf(stderr
, "noip(%d): realconnect acl:\n", pid
);
1487 dump_acl(connect_real
);
1488 fprintf(stderr
, "noip(%d): impbind list:\n", pid
);
1489 dump_impbind_list(); )
1492 /*----- Overridden system calls -------------------------------------------*/
1494 static void dump_syserr(long rc
)
1495 { fprintf(stderr
, " => %ld (E%d)\n", rc
, errno
); }
1497 static void dump_sysresult(long rc
)
1499 if (rc
< 0) dump_syserr(rc
);
1500 else fprintf(stderr
, " => %ld\n", rc
);
1503 static void dump_addrresult(long rc
, const struct sockaddr
*sa
,
1506 char addrbuf
[ADDRBUFSZ
];
1508 if (rc
< 0) dump_syserr(rc
);
1510 fprintf(stderr
, " => %ld [%s]\n", rc
,
1511 present_sockaddr(sa
, len
, addrbuf
, sizeof(addrbuf
)));
1515 int socket(int pf
, int ty
, int proto
)
1519 D( fprintf(stderr
, "noip(%d): SOCKET pf=%d, type=%d, proto=%d",
1520 getpid(), pf
, ty
, proto
); )
1524 if (!family_known_p(pf
)) {
1525 D( fprintf(stderr
, " -> unknown; refuse\n"); )
1526 errno
= EAFNOSUPPORT
;
1529 D( fprintf(stderr
, " -> inet; substitute"); )
1537 D( fprintf(stderr
, " -> safe; permit"); )
1540 sk
= real_socket(pf
, ty
, proto
);
1541 D( dump_sysresult(sk
); )
1545 int socketpair(int pf
, int ty
, int proto
, int *sk
)
1549 D( fprintf(stderr
, "noip(%d): SOCKETPAIR pf=%d, type=%d, proto=%d",
1550 getpid(), pf
, ty
, proto
); )
1551 if (!family_known_p(pf
))
1552 D( fprintf(stderr
, " -> unknown; permit"); )
1554 D( fprintf(stderr
, " -> inet; substitute"); )
1558 rc
= real_socketpair(pf
, ty
, proto
, sk
);
1559 D( if (rc
< 0) dump_syserr(rc
);
1560 else fprintf(stderr
, " => %d (%d, %d)\n", rc
, sk
[0], sk
[1]); )
1564 int bind(int sk
, const struct sockaddr
*sa
, socklen_t len
)
1566 struct sockaddr_un sun
;
1570 D({ char buf
[ADDRBUFSZ
];
1571 fprintf(stderr
, "noip(%d): BIND sk=%d, sa[%d]=%s", pid
,
1572 sk
, len
, present_sockaddr(sa
, len
, buf
, sizeof(buf
))); })
1574 if (!family_known_p(sa
->sa_family
))
1575 D( fprintf(stderr
, " -> unknown af; pass through"); )
1577 D( fprintf(stderr
, " -> checking...\n"); )
1579 if (acl_allows_p(bind_real
, sa
)) {
1580 if (fixup_real_ip_socket(sk
, sa
->sa_family
, 0))
1583 encode_inet_addr(&sun
, sa
, ENCF_FRESH
);
1585 len
= SUN_LEN(&sun
);
1588 D( fprintf(stderr
, "noip(%d): BIND ...", pid
); )
1590 rc
= real_bind(sk
, sa
, len
);
1591 D( dump_sysresult(rc
); )
1595 int connect(int sk
, const struct sockaddr
*sa
, socklen_t len
)
1597 struct sockaddr_un sun
;
1601 D({ char buf
[ADDRBUFSZ
];
1602 fprintf(stderr
, "noip(%d): CONNECT sk=%d, sa[%d]=%s", pid
,
1603 sk
, len
, present_sockaddr(sa
, len
, buf
, sizeof(buf
))); })
1605 if (!family_known_p(sa
->sa_family
)) {
1606 D( fprintf(stderr
, " -> unknown af; pass through"); )
1607 rc
= real_connect(sk
, sa
, len
);
1609 D( fprintf(stderr
, " -> checking...\n"); )
1611 fixup_client_socket(sk
, &sa
, &len
, &sun
);
1613 D( fprintf(stderr
, "noip(%d): CONNECT ...", pid
); )
1614 rc
= real_connect(sk
, sa
, len
);
1617 case ENOENT
: errno
= ECONNREFUSED
; break;
1621 D( dump_sysresult(rc
); )
1625 ssize_t
sendto(int sk
, const void *buf
, size_t len
, int flags
,
1626 const struct sockaddr
*to
, socklen_t tolen
)
1628 struct sockaddr_un sun
;
1632 D({ char addrbuf
[ADDRBUFSZ
];
1633 fprintf(stderr
, "noip(%d): SENDTO sk=%d, len=%lu, flags=%d, to[%d]=%s",
1634 pid
, sk
, (unsigned long)len
, flags
, tolen
,
1635 present_sockaddr(to
, tolen
, addrbuf
, sizeof(addrbuf
))); })
1638 D( fprintf(stderr
, " -> null address; leaving"); )
1639 else if (!family_known_p(to
->sa_family
))
1640 D( fprintf(stderr
, " -> unknown af; pass through"); )
1642 D( fprintf(stderr
, " -> checking...\n"); )
1644 fixup_client_socket(sk
, &to
, &tolen
, &sun
);
1646 D( fprintf(stderr
, "noip(%d): SENDTO ...", pid
); )
1648 n
= real_sendto(sk
, buf
, len
, flags
, to
, tolen
);
1649 D( dump_sysresult(n
); )
1653 ssize_t
recvfrom(int sk
, void *buf
, size_t len
, int flags
,
1654 struct sockaddr
*from
, socklen_t
*fromlen
)
1657 socklen_t mylen
= sizeof(sabuf
);
1661 D( fprintf(stderr
, "noip(%d): RECVFROM sk=%d, len=%lu, flags=%d",
1662 pid
, sk
, (unsigned long)len
, flags
); )
1665 D( fprintf(stderr
, " -> null addr; pass through"); )
1666 n
= real_recvfrom(sk
, buf
, len
, flags
, 0, 0);
1669 n
= real_recvfrom(sk
, buf
, len
, flags
, SA(sabuf
), &mylen
);
1671 D( fprintf(stderr
, " -> converting...\n"); )
1672 return_fake_name(SA(sabuf
), mylen
, from
, fromlen
);
1673 D( fprintf(stderr
, "noip(%d): ... RECVFROM", pid
); )
1677 D( dump_addrresult(n
, from
, fromlen ?
*fromlen
: 0); )
1681 ssize_t
sendmsg(int sk
, const struct msghdr
*msg
, int flags
)
1683 struct sockaddr_un sun
;
1684 const struct sockaddr
*sa
= SA(msg
->msg_name
);
1685 struct msghdr mymsg
;
1689 D({ char addrbuf
[ADDRBUFSZ
];
1690 fprintf(stderr
, "noip(%d): SENDMSG sk=%d, "
1691 "msg_flags=%d, msg_name[%d]=%s, ...",
1692 pid
, sk
, msg
->msg_flags
, msg
->msg_namelen
,
1693 present_sockaddr(sa
, msg
->msg_namelen
,
1694 addrbuf
, sizeof(addrbuf
))); })
1697 D( fprintf(stderr
, " -> null address; leaving"); )
1698 else if (!family_known_p(sa
->sa_family
))
1699 D( fprintf(stderr
, " -> unknown af; pass through"); )
1701 D( fprintf(stderr
, " -> checking...\n"); )
1704 fixup_client_socket(sk
, &sa
, &mymsg
.msg_namelen
, &sun
);
1705 mymsg
.msg_name
= SA(sa
);
1708 D( fprintf(stderr
, "noip(%d): SENDMSG ...", pid
); )
1710 n
= real_sendmsg(sk
, msg
, flags
);
1711 D( dump_sysresult(n
); )
1715 ssize_t
recvmsg(int sk
, struct msghdr
*msg
, int flags
)
1718 struct sockaddr
*sa
= SA(msg
->msg_name
);
1719 socklen_t len
= msg
->msg_namelen
;
1723 D( fprintf(stderr
, "noip(%d): RECVMSG sk=%d msg_flags=%d, ...",
1724 pid
, sk
, msg
->msg_flags
); )
1726 if (!msg
->msg_name
) {
1727 D( fprintf(stderr
, " -> null addr; pass through"); )
1728 return (real_recvmsg(sk
, msg
, flags
));
1731 msg
->msg_name
= sabuf
;
1732 msg
->msg_namelen
= sizeof(sabuf
);
1733 n
= real_recvmsg(sk
, msg
, flags
);
1735 D( fprintf(stderr
, " -> converting...\n"); )
1736 return_fake_name(SA(sabuf
), msg
->msg_namelen
, sa
, &len
);
1737 D( fprintf(stderr
, "noip(%d): ... RECVMSG", pid
); )
1740 msg
->msg_namelen
= len
;
1743 D( dump_addrresult(n
, sa
, len
); )
1747 int accept(int sk
, struct sockaddr
*sa
, socklen_t
*len
)
1750 socklen_t mylen
= sizeof(sabuf
);
1754 D( fprintf(stderr
, "noip(%d): ACCEPT sk=%d", pid
, sk
); )
1756 nsk
= real_accept(sk
, SA(sabuf
), &mylen
);
1757 if (nsk
< 0) /* failed */;
1758 else if (!sa
) D( fprintf(stderr
, " -> address not wanted"); )
1760 D( fprintf(stderr
, " -> converting...\n"); )
1761 return_fake_name(SA(sabuf
), mylen
, sa
, len
);
1762 D( fprintf(stderr
, "noip(%d): ... ACCEPT", pid
); )
1764 D( dump_addrresult(nsk
, sa
, len ?
*len
: 0); )
1768 int getsockname(int sk
, struct sockaddr
*sa
, socklen_t
*len
)
1771 socklen_t mylen
= sizeof(sabuf
);
1775 D( fprintf(stderr
, "noip(%d): GETSOCKNAME sk=%d", pid
, sk
); )
1776 rc
= real_getsockname(sk
, SA(sabuf
), &mylen
);
1778 D( fprintf(stderr
, " -> converting...\n"); )
1779 return_fake_name(SA(sabuf
), mylen
, sa
, len
);
1780 D( fprintf(stderr
, "noip(%d): ... GETSOCKNAME", pid
); )
1782 D( dump_addrresult(rc
, sa
, *len
); )
1786 int getpeername(int sk
, struct sockaddr
*sa
, socklen_t
*len
)
1789 socklen_t mylen
= sizeof(sabuf
);
1793 D( fprintf(stderr
, "noip(%d): GETPEERNAME sk=%d", pid
, sk
); )
1794 rc
= real_getpeername(sk
, SA(sabuf
), &mylen
);
1796 D( fprintf(stderr
, " -> converting...\n"); )
1797 return_fake_name(SA(sabuf
), mylen
, sa
, len
);
1798 D( fprintf(stderr
, "noip(%d): ... GETPEERNAME", pid
); )
1800 D( dump_addrresult(rc
, sa
, *len
); )
1804 int getsockopt(int sk
, int lev
, int opt
, void *p
, socklen_t
*len
)
1815 return (real_getsockopt(sk
, lev
, opt
, p
, len
));
1818 int setsockopt(int sk
, int lev
, int opt
, const void *p
, socklen_t len
)
1828 case SO_BINDTODEVICE
:
1829 case SO_ATTACH_FILTER
:
1830 case SO_DETACH_FILTER
:
1833 return (real_setsockopt(sk
, lev
, opt
, p
, len
));
1836 int ioctl(int fd
, unsigned long op
, ...)
1844 arg
= va_arg(ap
, void *);
1848 case SIOCGIFBRDADDR
:
1849 case SIOCGIFDSTADDR
:
1850 case SIOCGIFNETMASK
:
1852 if (fixup_real_ip_socket(fd
, AF_INET
, &sk
)) goto real
;
1854 rc
= real_ioctl(sk
, op
, arg
);
1855 PRESERVING_ERRNO({ close(sk
); });
1859 rc
= real_ioctl(fd
, op
, arg
);
1866 /*----- Initialization ----------------------------------------------------*/
1868 /* Clean up the socket directory, deleting stale sockets. */
1869 static void cleanup_sockdir(void)
1874 struct sockaddr_un sun
;
1878 if ((dir
= opendir(sockdir
)) == 0) return;
1879 sun
.sun_family
= AF_UNIX
;
1880 while ((d
= readdir(dir
)) != 0) {
1881 if (d
->d_name
[0] == '.') continue;
1882 snprintf(sun
.sun_path
, sizeof(sun
.sun_path
),
1883 "%s/%s", sockdir
, d
->d_name
);
1884 if (decode_inet_addr(&addr
.sa
, 0, &sun
, SUN_LEN(&sun
)) ||
1885 stat(sun
.sun_path
, &st
) ||
1886 !S_ISSOCK(st
.st_mode
)) {
1887 D( fprintf(stderr
, "noip(%d): ignoring unknown socketdir entry `%s'\n",
1888 pid
, sun
.sun_path
); )
1891 if (unix_socket_status(&sun
, 0) == STALE
) {
1892 D( fprintf(stderr
, "noip(%d): clearing away stale socket %s\n",
1894 unlink(sun
.sun_path
);
1900 /* Find the addresses attached to local network interfaces, and remember them
1903 static void get_local_ipaddrs(void)
1905 struct ifaddrs
*ifa_head
, *ifa
;
1910 D( fprintf(stderr
, "noip(%d): fetching local addresses...\n", pid
); )
1911 if (getifaddrs(&ifa_head
)) { perror("getifaddrs"); return; }
1912 for (n_local_ipaddrs
= 0, ifa
= ifa_head
;
1913 n_local_ipaddrs
< MAX_LOCAL_IPADDRS
&& ifa
;
1914 ifa
= ifa
->ifa_next
) {
1915 if (!ifa
->ifa_addr
|| !family_known_p(ifa
->ifa_addr
->sa_family
))
1917 ipaddr_from_sockaddr(&a
, ifa
->ifa_addr
);
1918 D({ char buf
[ADDRBUFSZ
];
1919 fprintf(stderr
, "noip(%d): local addr %s = %s", pid
,
1921 inet_ntop(ifa
->ifa_addr
->sa_family
, &a
,
1922 buf
, sizeof(buf
))); })
1923 for (i
= 0; i
< n_local_ipaddrs
; i
++) {
1924 if (ifa
->ifa_addr
->sa_family
== local_ipaddrs
[i
].af
&&
1925 ipaddr_equal_p(local_ipaddrs
[i
].af
, &a
, &local_ipaddrs
[i
].addr
)) {
1926 D( fprintf(stderr
, " (duplicate)\n"); )
1930 D( fprintf(stderr
, "\n"); )
1931 local_ipaddrs
[n_local_ipaddrs
].af
= ifa
->ifa_addr
->sa_family
;
1932 local_ipaddrs
[n_local_ipaddrs
].addr
= a
;
1936 freeifaddrs(ifa_head
);
1939 /* Print the given message to standard error. Avoids stdio. */
1940 static void printerr(const char *p
)
1941 { if (write(STDERR_FILENO
, p
, strlen(p
))) ; }
1943 /* Create the socket directory, being careful about permissions. */
1944 static void create_sockdir(void)
1948 if (lstat(sockdir
, &st
)) {
1949 if (errno
== ENOENT
) {
1950 if (mkdir(sockdir
, 0700)) {
1951 perror("noip: creating socketdir");
1954 if (!lstat(sockdir
, &st
))
1957 perror("noip: checking socketdir");
1961 if (!S_ISDIR(st
.st_mode
)) {
1962 printerr("noip: bad socketdir: not a directory\n");
1965 if (st
.st_uid
!= uid
) {
1966 printerr("noip: bad socketdir: not owner\n");
1969 if (st
.st_mode
& 077) {
1970 printerr("noip: bad socketdir: not private\n");
1975 /* Initialization function. */
1976 static void setup(void) __attribute__((constructor
));
1977 static void setup(void)
1984 if ((p
= getenv("NOIP_DEBUG")) && atoi(p
))
1986 get_local_ipaddrs();
1993 /*----- That's all, folks -------------------------------------------------*/