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 /* Convert an AF_INET socket address into the equivalent IPv4-mapped AF_INET6
345 static void map_ipv4_sockaddr(struct sockaddr_in6
*a6
,
346 const struct sockaddr_in
*a4
)
349 in_addr_t a
= ntohl(a4
->sin_addr
.s_addr
);
351 a6
->sin6_family
= AF_INET6
;
352 a6
->sin6_port
= a4
->sin_port
;
353 a6
->sin6_scope_id
= 0;
354 a6
->sin6_flowinfo
= 0;
355 for (i
= 0; i
< 10; i
++) a6
->sin6_addr
.s6_addr
[i
] = 0;
356 for (i
= 10; i
< 12; i
++) a6
->sin6_addr
.s6_addr
[i
] = 0xff;
357 for (i
= 0; i
< 4; i
++) a6
->sin6_addr
.s6_addr
[15 - i
] = (a
>> 8*i
)&0xff;
360 /* Convert an AF_INET6 socket address containing an IPv4-mapped IPv6 address
361 * into the equivalent AF_INET4 address. Return zero on success, or -1 if
362 * the address has the wrong form.
364 static int unmap_ipv4_sockaddr(struct sockaddr_in
*a4
,
365 const struct sockaddr_in6
*a6
)
370 for (i
= 0; i
< 10; i
++) if (a6
->sin6_addr
.s6_addr
[i
] != 0) return (-1);
371 for (i
= 10; i
< 12; i
++) if (a6
->sin6_addr
.s6_addr
[i
] != 0xff) return (-1);
372 for (i
= 0, a
= 0; i
< 4; i
++) a
|= a6
->sin6_addr
.s6_addr
[15 - i
] << 8*i
;
373 a4
->sin_family
= AF_INET
;
374 a4
->sin_port
= a6
->sin6_port
;
375 a4
->sin_addr
.s_addr
= htonl(a
);
379 /* Answer whether two addresses are equal. */
380 static int ipaddr_equal_p(int af
, const ipaddr
*a
, const ipaddr
*b
)
383 case AF_INET
: return (a
->v4
.s_addr
== b
->v4
.s_addr
);
384 case AF_INET6
: return (memcmp(a
->v6
.s6_addr
, b
->v6
.s6_addr
, 16) == 0);
389 /* Answer whether the address part of SA is between A and B (inclusive). We
390 * assume that SA has the correct address family.
392 static int sockaddr_in_range_p(const struct sockaddr
*sa
,
393 const ipaddr
*a
, const ipaddr
*b
)
395 switch (sa
->sa_family
) {
397 unsigned long addr
= ntohl(SIN(sa
)->sin_addr
.s_addr
);
398 return (ntohl(a
->v4
.s_addr
) <= addr
&&
399 addr
<= ntohl(b
->v4
.s_addr
));
402 const uint8_t *ss
= SIN6(sa
)->sin6_addr
.s6_addr
;
403 const uint8_t *aa
= a
->v6
.s6_addr
, *bb
= b
->v6
.s6_addr
;
407 for (i
= 0; h
&& l
&& i
< 16; i
++, ss
++, aa
++, bb
++) {
408 if (*ss
< *aa
|| *bb
< *ss
) return (0);
409 if (*aa
< *ss
) l
= 0;
410 if (*ss
< *bb
) h
= 0;
419 /* Fill in SA with the appropriate wildcard address. */
420 static void wildcard_address(int af
, struct sockaddr
*sa
)
424 struct sockaddr_in
*sin
= SIN(sa
);
425 memset(sin
, 0, sizeof(*sin
));
426 sin
->sin_family
= AF_INET
;
428 sin
->sin_addr
.s_addr
= INADDR_ANY
;
431 struct sockaddr_in6
*sin6
= SIN6(sa
);
432 memset(sin6
, 0, sizeof(*sin6
));
433 sin6
->sin6_family
= AF_INET6
;
435 sin6
->sin6_addr
= in6addr_any
;
436 sin6
->sin6_scope_id
= 0;
437 sin6
->sin6_flowinfo
= 0;
444 /* Mask the address A, forcing all but the top PLEN bits to zero or one
445 * according to HIGHP.
447 static void mask_address(int af
, ipaddr
*a
, int plen
, int highp
)
451 unsigned long addr
= ntohl(a
->v4
.s_addr
);
452 unsigned long mask
= plen ?
~0ul << (32 - plen
) : 0;
454 if (highp
) addr
|= ~mask
;
455 a
->v4
.s_addr
= htonl(addr
& 0xffffffff);
459 unsigned m
= (0xff << (8 - plen
%8)) & 0xff;
460 unsigned s
= highp ?
0xff : 0;
462 a
->v6
.s6_addr
[i
] = (a
->v6
.s6_addr
[i
] & m
) | (s
& ~m
);
465 for (; i
< 16; i
++) a
->v6
.s6_addr
[i
] = s
;
472 /* Write a presentation form of SA to BUF, a buffer of length SZ. LEN is the
473 * address length; if it's zero, look it up based on the address family.
474 * Return a pointer to the string (which might, in an emergency, be a static
475 * string rather than your buffer).
477 static char *present_sockaddr(const struct sockaddr
*sa
, socklen_t len
,
478 char *buf
, size_t sz
)
480 #define WANT(n_) do { if (sz < (n_)) goto nospace; } while (0)
481 #define PUTC(c_) do { *buf++ = (c_); sz--; } while (0)
483 if (!sa
) return "<null-address>";
484 if (!sz
) return "<no-space-in-buffer>";
485 if (!len
) len
= family_socklen(sa
->sa_family
);
487 switch (sa
->sa_family
) {
489 struct sockaddr_un
*sun
= SUN(sa
);
490 char *p
= sun
->sun_path
;
491 size_t n
= len
- offsetof(struct sockaddr_un
, sun_path
);
499 case 0: WANT(2); PUTC('\\'); PUTC('0'); break;
500 case '\a': WANT(2); PUTC('\\'); PUTC('a'); break;
501 case '\n': WANT(2); PUTC('\\'); PUTC('n'); break;
502 case '\r': WANT(2); PUTC('\\'); PUTC('r'); break;
503 case '\t': WANT(2); PUTC('\\'); PUTC('t'); break;
504 case '\v': WANT(2); PUTC('\\'); PUTC('v'); break;
505 case '\\': WANT(2); PUTC('\\'); PUTC('\\'); break;
507 if (*p
> ' ' && *p
<= '~')
508 { WANT(1); PUTC(*p
); }
510 WANT(4); PUTC('\\'); PUTC('x');
511 PUTC((*p
>> 4)&0xf); PUTC((*p
>> 0)&0xf);
518 if (*p
!= '/') { WANT(2); PUTC('.'); PUTC('/'); }
519 while (n
&& *p
) { WANT(1); PUTC(*p
); p
++; n
--; }
523 case AF_INET
: case AF_INET6
: {
524 char addrbuf
[NI_MAXHOST
], portbuf
[NI_MAXSERV
];
525 int err
= getnameinfo(sa
, len
,
526 addrbuf
, sizeof(addrbuf
),
527 portbuf
, sizeof(portbuf
),
528 NI_NUMERICHOST
| NI_NUMERICSERV
);
530 snprintf(buf
, sz
, strchr(addrbuf
, ':') ?
"[%s]:%s" : "%s:%s",
534 snprintf(buf
, sz
, "<unknown-address-family %d>", sa
->sa_family
);
544 /* Guess the family of a textual socket address. */
545 static int guess_address_family(const char *p
)
546 { return (strchr(p
, ':') ? AF_INET6
: AF_INET
); }
548 /* Parse a socket address P and write the result to SA. */
549 static int parse_sockaddr(struct sockaddr
*sa
, const char *p
)
553 struct addrinfo
*ai
, ai_hint
= { 0 };
555 if (strlen(p
) >= sizeof(buf
) - 1) return (-1);
556 strcpy(buf
, p
); p
= buf
;
558 if ((q
= strchr(p
, ':')) == 0) return (-1);
562 if ((q
= strchr(p
, ']')) == 0) return (-1);
564 if (*q
!= ':') return (-1);
568 ai_hint
.ai_family
= AF_UNSPEC
;
569 ai_hint
.ai_socktype
= SOCK_DGRAM
;
570 ai_hint
.ai_flags
= AI_NUMERICHOST
| AI_NUMERICSERV
;
571 if (getaddrinfo(p
, q
, &ai_hint
, &ai
)) return (-1);
572 memcpy(sa
, ai
->ai_addr
, ai
->ai_addrlen
);
577 /*----- Access control lists ----------------------------------------------*/
581 static void dump_addrrange(int af
, const ipaddr
*min
, const ipaddr
*max
)
587 plen
= common_prefix_length(af
, min
, max
);
588 p
= inet_ntop(af
, min
, buf
, sizeof(buf
));
589 fprintf(stderr
, strchr(p
, ':') ?
"[%s]" : "%s", p
);
591 p
= inet_ntop(af
, &max
, buf
, sizeof(buf
));
592 fprintf(stderr
, strchr(p
, ':') ?
"-[%s]" : "-%s", p
);
593 } else if (plen
< address_width(af
))
594 fprintf(stderr
, "/%d", plen
);
597 /* Write to standard error a description of the ACL node A. */
598 static void dump_aclnode(const aclnode
*a
)
600 fprintf(stderr
, "noip(%d): %c ", getpid(), a
->act ?
'+' : '-');
601 dump_addrrange(a
->af
, &a
->minaddr
, &a
->maxaddr
);
602 if (a
->minport
!= 0 || a
->maxport
!= 0xffff) {
603 fprintf(stderr
, ":%u", (unsigned)a
->minport
);
604 if (a
->minport
!= a
->maxport
)
605 fprintf(stderr
, "-%u", (unsigned)a
->maxport
);
610 static void dump_acl(const aclnode
*a
)
614 for (; a
; a
= a
->next
) {
618 fprintf(stderr
, "noip(%d): [default policy: %s]\n", getpid(),
619 act
== ALLOW ?
"DENY" : "ALLOW");
624 /* Returns nonzero if the ACL A allows the socket address SA. */
625 static int acl_allows_p(const aclnode
*a
, const struct sockaddr
*sa
)
627 unsigned short port
= port_from_sockaddr(sa
);
631 D({ char buf
[ADDRBUFSZ
];
632 fprintf(stderr
, "noip(%d): check %s\n", pid
,
633 present_sockaddr(sa
, 0, buf
, sizeof(buf
))); })
634 for (; a
; a
= a
->next
) {
635 D( dump_aclnode(a
); )
636 if (a
->af
== sa
->sa_family
&&
637 sockaddr_in_range_p(sa
, &a
->minaddr
, &a
->maxaddr
) &&
638 a
->minport
<= port
&& port
<= a
->maxport
) {
639 D( fprintf(stderr
, "noip(%d): aha! %s\n", pid
,
640 a
->act ?
"ALLOW" : "DENY"); )
645 D( fprintf(stderr
, "noip(%d): nothing found: %s\n", pid
,
646 act ?
"DENY" : "ALLOW"); )
650 /*----- Socket address conversion -----------------------------------------*/
652 /* Return a uniformly distributed integer between MIN and MAX inclusive. */
653 static unsigned randrange(unsigned min
, unsigned max
)
657 /* It's so nice not to have to care about the quality of the generator
661 for (mask
= 1; mask
< max
; mask
= (mask
<< 1) | 1)
663 do i
= rand() & mask
; while (i
> max
);
667 /* Return the status of Unix-domain socket address SUN. Returns: UNUSED if
668 * the socket doesn't exist; USED if the path refers to an active socket, or
669 * isn't really a socket at all, or we can't tell without a careful search
670 * and QUICKP is set; or STALE if the file refers to a socket which isn't
671 * being used any more.
673 static int unix_socket_status(struct sockaddr_un
*sun
, int quickp
)
681 /* If we can't find the socket node, then it's definitely not in use. If
682 * we get some other error, then this socket is weird.
684 if (stat(sun
->sun_path
, &st
))
685 return (errno
== ENOENT ? UNUSED
: USED
);
687 /* If it's not a socket, then something weird is going on. If we're just
688 * probing quickly to find a spare port, then existence is sufficient to
691 if (!S_ISSOCK(st
.st_mode
) || quickp
)
694 /* The socket's definitely there, but is anyone actually still holding it
695 * open? The only way I know to discover this is to trundle through
696 * `/proc/net/unix'. If there's no entry, then the socket must be stale.
699 if ((fp
= fopen("/proc/net/unix", "r")) == 0)
701 if (!fgets(buf
, sizeof(buf
), fp
)) goto done
; /* skip header */
702 len
= strlen(sun
->sun_path
);
703 while (fgets(buf
, sizeof(buf
), fp
)) {
705 if (n
>= len
+ 2 && buf
[n
- len
- 2] == ' ' && buf
[n
- 1] == '\n' &&
706 memcmp(buf
+ n
- len
- 1, sun
->sun_path
, len
) == 0)
719 /* Encode SA as a Unix-domain address SUN, and return whether it's currently
722 static int encode_single_inet_addr(const struct sockaddr
*sa
,
723 struct sockaddr_un
*sun
,
729 snprintf(sun
->sun_path
, sizeof(sun
->sun_path
), "%s/%s", sockdir
,
730 present_sockaddr(sa
, 0, buf
, sizeof(buf
)));
731 if ((rc
= unix_socket_status(sun
, quickp
)) == USED
) return (USED
);
732 else if (rc
== STALE
) unlink(sun
->sun_path
);
736 /* Convert the IP address SA to a Unix-domain address SUN. Fail if the
737 * address seems already taken. If DESPARATEP then try cleaning up stale old
740 static int encode_unused_inet_addr(struct sockaddr
*sa
,
741 struct sockaddr_un
*sun
,
744 address waddr
, maddr
;
745 struct sockaddr_un wsun
;
746 int port
= port_from_sockaddr(sa
);
748 /* First, look for an exact match. Only look quickly unless we're
749 * desperate. If the socket is in use, we fail here. (This could get
750 * racy. Let's not worry about that for now.)
752 if (encode_single_inet_addr(sa
, sun
, !desperatep
) == USED
)
755 /* Next, check the corresponding wildcard address, so as to avoid
756 * inadvertant collisions with listeners. Do this in the same way.
758 wildcard_address(sa
->sa_family
, &waddr
.sa
);
759 port_to_sockaddr(&waddr
.sa
, port
);
760 if (encode_single_inet_addr(&waddr
.sa
, &wsun
, !desperatep
) == USED
)
763 /* We're not done yet. If this is an IPv4 address, then /also/ check (a)
764 * the v6-mapped version, (b) the v6-mapped v4 wildcard, /and/ (c) the v6
767 if (sa
->sa_family
== AF_INET
) {
768 map_ipv4_sockaddr(&maddr
.sin6
, SIN(&sa
));
769 if (encode_single_inet_addr(&maddr
.sa
, &wsun
, !desperatep
) == USED
)
772 map_ipv4_sockaddr(&maddr
.sin6
, &waddr
.sin
);
773 if (encode_single_inet_addr(&maddr
.sa
, &wsun
, !desperatep
) == USED
)
776 wildcard_address(AF_INET6
, &waddr
.sa
);
777 port_to_sockaddr(&waddr
.sa
, port
);
778 if (encode_single_inet_addr(&waddr
.sa
, &wsun
, !desperatep
) == USED
)
786 /* Encode the Internet address SA as a Unix-domain address SUN. If the flag
787 * `ENCF_FRESH' is set, and SA's port number is zero, then we pick an
788 * arbitrary local port. Otherwise we pick the port given. There's an
789 * unpleasant hack to find servers bound to local wildcard addresses.
790 * Returns zero on success; -1 on failure.
792 #define ENCF_FRESH 1u
793 static int encode_inet_addr(struct sockaddr_un
*sun
,
794 const struct sockaddr
*sa
,
800 struct sockaddr_in6 sin6
;
801 int port
= port_from_sockaddr(sa
);
804 D( fprintf(stderr
, "noip(%d): encode %s (%s)", getpid(),
805 present_sockaddr(sa
, 0, buf
, sizeof(buf
)),
806 (f
&ENCF_FRESH
) ?
"FRESH" : "EXISTING"); )
808 /* Start making the Unix-domain address. */
809 sun
->sun_family
= AF_UNIX
;
811 if (port
|| !(f
&ENCF_FRESH
)) {
813 /* Try the address as given. If it's in use, or we don't necessarily
814 * want an existing socket, then we're done.
816 if (encode_single_inet_addr(sa
, sun
, 0) == USED
|| (f
&ENCF_FRESH
))
819 /* We're looking for a socket which already exists. This is
820 * unfortunately difficult, because we must deal both with wildcards and
821 * v6-mapped IPv4 addresses.
823 * * We've just tried searching for a socket whose name is an exact
824 * match for our remote address. If the remote address is IPv4, then
825 * we should try again with the v6-mapped equivalent.
827 * * Failing that, we try again with the wildcard address for the
828 * appropriate address family.
830 * * Failing /that/, if the remote address is IPv4, then we try
831 * /again/, increasingly desperately, first with the v6-mapped IPv4
832 * wildcard address, and then with the IPv6 wildcard address. This
833 * will cause magic v6-mapping to occur when the connection is
834 * accepted, which we hope won't cause too much trouble.
837 if (sa
->sa_family
== AF_INET
) {
838 map_ipv4_sockaddr(&addr
.sin6
, SIN(sa
));
839 if (encode_single_inet_addr(&addr
.sa
, sun
, 0) == USED
) goto found
;
842 wildcard_address(sa
->sa_family
, &addr
.sa
);
843 port_to_sockaddr(&addr
.sa
, port
);
844 if (encode_single_inet_addr(&addr
.sa
, sun
, 0) == USED
) goto found
;
846 if (sa
->sa_family
== AF_INET
) {
847 map_ipv4_sockaddr(&sin6
, &addr
.sin
);
848 if (encode_single_inet_addr(SA(&sin6
), sun
, 0) == USED
) goto found
;
849 wildcard_address(AF_INET6
, &addr
.sa
);
850 port_to_sockaddr(&addr
.sa
, port
);
851 if (encode_single_inet_addr(&addr
.sa
, sun
, 0) == USED
) goto found
;
854 /* Well, this isn't going to work (unless a miraculous race is lost), but
855 * we might as well try.
857 encode_single_inet_addr(sa
, sun
, 1);
860 /* We want a fresh new socket. */
862 /* Make a copy of the given address, because we're going to mangle it. */
863 copy_sockaddr(&addr
.sa
, sa
);
865 /* Try a few random-ish port numbers to see if any of them is spare. */
866 for (i
= 0; i
< 10; i
++) {
867 port_to_sockaddr(&addr
.sa
, randrange(minautoport
, maxautoport
));
868 if (!encode_unused_inet_addr(&addr
.sa
, sun
, 0)) goto found
;
871 /* Things must be getting tight. Work through all of the autoport range
872 * to see if we can find a spare one. The first time, just do it the
873 * quick way; if that doesn't work, then check harder for stale sockets.
875 for (desperatep
= 0; desperatep
< 2; desperatep
++) {
876 for (i
= minautoport
; i
<= maxautoport
; i
++) {
877 port_to_sockaddr(&addr
.sa
, i
);
878 if (!encode_unused_inet_addr(&addr
.sa
, sun
, 0)) goto found
;
882 /* We failed to find any free ports. */
884 D( fprintf(stderr
, " -- can't resolve\n"); )
890 D( fprintf(stderr
, " -> `%s'\n", sun
->sun_path
); )
894 /* Decode the Unix address SUN to an Internet address SIN. If AF_HINT is
895 * nonzero, an empty address (indicative of an unbound Unix-domain socket) is
896 * translated to a wildcard Internet address of the appropriate family.
897 * Returns zero on success; -1 on failure (e.g., it wasn't one of our
900 static int decode_inet_addr(struct sockaddr
*sa
, int af_hint
,
901 const struct sockaddr_un
*sun
,
905 size_t n
= strlen(sockdir
), nn
;
908 if (!sa
) sa
= &addr
.sa
;
909 if (sun
->sun_family
!= AF_UNIX
) return (-1);
910 if (len
> sizeof(*sun
)) return (-1);
911 ((char *)sun
)[len
] = 0;
912 nn
= strlen(sun
->sun_path
);
913 D( fprintf(stderr
, "noip(%d): decode `%s'", getpid(), sun
->sun_path
); )
914 if (af_hint
&& !sun
->sun_path
[0]) {
915 wildcard_address(af_hint
, sa
);
916 D( fprintf(stderr
, " -- unbound socket\n"); )
919 if (nn
< n
+ 1 || nn
- n
>= sizeof(buf
) || sun
->sun_path
[n
] != '/' ||
920 memcmp(sun
->sun_path
, sockdir
, n
) != 0) {
921 D( fprintf(stderr
, " -- not one of ours\n"); )
924 if (parse_sockaddr(sa
, sun
->sun_path
+ n
+ 1)) return (-1);
925 D( fprintf(stderr
, " -> %s\n",
926 present_sockaddr(sa
, 0, buf
, sizeof(buf
))); )
930 /* SK is (or at least might be) a Unix-domain socket we created when an
931 * Internet socket was asked for. We've decided it should be an Internet
932 * socket after all, with family AF_HINT, so convert it. If TMP is not null,
933 * then don't replace the existing descriptor: store the new socket in *TMP
936 static int fixup_real_ip_socket(int sk
, int af_hint
, int *tmp
)
941 struct sockaddr_un sun
;
954 _(LINGER, struct linger) \
957 _(RCVTIMEO, struct timeval) \
958 _(SNDTIMEO, struct timeval)
961 if (real_getsockname(sk
, SA(&sun
), &len
))
963 if (decode_inet_addr(&addr
.sa
, af_hint
, &sun
, len
))
964 return (0); /* Not one of ours */
966 if (real_getsockopt(sk
, SOL_SOCKET
, SO_TYPE
, &type
, &len
) < 0 ||
967 (nsk
= real_socket(addr
.sa
.sa_family
, type
, 0)) < 0)
969 #define FIX(opt, ty) do { \
972 if (real_getsockopt(sk, SOL_SOCKET, SO_##opt, &ov_, &len) < 0 || \
973 real_setsockopt(nsk, SOL_SOCKET, SO_##opt, &ov_, len)) { \
983 if ((f
= fcntl(sk
, F_GETFL
)) < 0 ||
984 (fd
= fcntl(sk
, F_GETFD
)) < 0 ||
985 fcntl(nsk
, F_SETFL
, f
) < 0 ||
990 unlink(sun
.sun_path
);
992 if (fcntl(sk
, F_SETFD
, fd
) < 0) {
993 perror("noip: fixup_real_ip_socket F_SETFD");
1000 /* We found the real address SA, with length LEN; if it's a Unix-domain
1001 * address corresponding to a fake socket, convert it to cover up the
1002 * deception. Whatever happens, put the result at FAKE and store its length
1005 #define FNF_V6MAPPED 1u
1006 static void return_fake_name(struct sockaddr
*sa
, socklen_t len
,
1007 struct sockaddr
*fake
, socklen_t
*fakelen
,
1011 struct sockaddr_in6 sin6
;
1014 if (sa
->sa_family
== AF_UNIX
&&
1015 !decode_inet_addr(&addr
.sa
, 0, SUN(sa
), len
)) {
1016 if (addr
.sa
.sa_family
!= AF_INET
|| !(f
&FNF_V6MAPPED
)) {
1018 len
= family_socklen(addr
.sa
.sa_family
);
1020 map_ipv4_sockaddr(&sin6
, &addr
.sin
);
1022 len
= family_socklen(AF_INET6
);
1026 if (len
> *fakelen
) len
= *fakelen
;
1027 if (len
> 0) memcpy(fake
, sa
, len
);
1031 /* Variant of `return_fake_name' above, specifically handling the weirdness
1032 * of remote v6-mapped IPv4 addresses. If SK's fake local address is IPv6,
1033 * and the remote address is IPv4, then return a v6-mapped version of the
1036 static void return_fake_peer(int sk
, struct sockaddr
*sa
, socklen_t len
,
1037 struct sockaddr
*fake
, socklen_t
*fakelen
)
1040 socklen_t mylen
= sizeof(sabuf
);
1046 rc
= real_getsockname(sk
, SA(sabuf
), &mylen
);
1047 if (!rc
&& sa
->sa_family
== AF_UNIX
&&
1048 !decode_inet_addr(&addr
.sa
, 0, SUN(sabuf
), mylen
) &&
1049 addr
.sa
.sa_family
== AF_INET6
)
1050 fnf
|= FNF_V6MAPPED
;
1052 return_fake_name(sa
, len
, fake
, fakelen
, fnf
);
1055 /*----- Implicit binding --------------------------------------------------*/
1059 static void dump_impbind(const impbind
*i
)
1061 char buf
[ADDRBUFSZ
];
1063 fprintf(stderr
, "noip(%d): ", getpid());
1064 dump_addrrange(i
->af
, &i
->minaddr
, &i
->maxaddr
);
1066 case SAME
: fprintf(stderr
, " <self>"); break;
1068 fprintf(stderr
, " %s", inet_ntop(i
->af
, &i
->bindaddr
,
1073 fputc('\n', stderr
);
1076 static void dump_impbind_list(void)
1080 for (i
= impbinds
; i
; i
= i
->next
) dump_impbind(i
);
1085 /* The socket SK is about to be used to communicate with the remote address
1086 * SA. Assign it a local address so that getpeername(2) does something
1089 * If the flag `IBF_V6MAPPED' is set then, then SA must be an `AF_INET'
1090 * address; after deciding on the appropriate local address, convert it to be
1091 * an IPv4-mapped IPv6 address before final conversion to a Unix-domain
1092 * socket address and actually binding. Note that this could well mean that
1093 * the socket ends up bound to the v6-mapped v4 wildcard address
1094 * ::ffff:0.0.0.0, which looks very strange but is meaningful.
1096 #define IBF_V6MAPPED 1u
1097 static int do_implicit_bind(int sk
, const struct sockaddr
*sa
, unsigned f
)
1100 struct sockaddr_in6 sin6
;
1101 struct sockaddr_un sun
;
1105 D( fprintf(stderr
, "noip(%d): checking impbind list...\n", pid
); )
1106 for (i
= impbinds
; i
; i
= i
->next
) {
1107 D( dump_impbind(i
); )
1108 if (sa
->sa_family
== i
->af
&&
1109 sockaddr_in_range_p(sa
, &i
->minaddr
, &i
->maxaddr
)) {
1110 D( fprintf(stderr
, "noip(%d): match!\n", pid
); )
1111 addr
.sa
.sa_family
= sa
->sa_family
;
1112 ipaddr_to_sockaddr(&addr
.sa
, &i
->bindaddr
);
1116 D( fprintf(stderr
, "noip(%d): no match; using wildcard\n", pid
); )
1117 wildcard_address(sa
->sa_family
, &addr
.sa
);
1119 if (addr
.sa
.sa_family
!= AF_INET
|| !(f
&IBF_V6MAPPED
)) sa
= &addr
.sa
;
1120 else { map_ipv4_sockaddr(&sin6
, &addr
.sin
); sa
= SA(&sin6
); }
1121 encode_inet_addr(&sun
, sa
, ENCF_FRESH
);
1122 D( fprintf(stderr
, "noip(%d): implicitly binding to %s\n",
1123 pid
, sun
.sun_path
); )
1124 if (real_bind(sk
, SA(&sun
), SUN_LEN(&sun
))) return (-1);
1128 /* The socket SK is about to communicate with the remote address *SA. Ensure
1129 * that the socket has a local address, and adjust *SA to refer to the real
1132 * If we need to translate the remote address, then the Unix-domain endpoint
1133 * address will end in *SUN, and *SA will be adjusted to point to it.
1135 static int fixup_client_socket(int sk
, const struct sockaddr
**sa_r
,
1136 socklen_t
*len_r
, struct sockaddr_un
*sun
)
1138 struct sockaddr_in sin
;
1139 socklen_t mylen
= sizeof(*sun
);
1140 const struct sockaddr
*sa
= *sa_r
;
1143 /* If this isn't a Unix-domain socket then there's nothing to do. */
1144 if (real_getsockname(sk
, SA(sun
), &mylen
) < 0) return (-1);
1145 if (sun
->sun_family
!= AF_UNIX
) return (0);
1146 if (mylen
< sizeof(*sun
)) ((char *)sun
)[mylen
] = 0;
1148 /* If the remote address is v6-mapped IPv4, then unmap it so as to search
1149 * for IPv4 servers. Also remember to v6-map the local address when we
1152 if (sa
->sa_family
== AF_INET6
&& !(unmap_ipv4_sockaddr(&sin
, SIN6(sa
)))) {
1154 ibf
|= IBF_V6MAPPED
;
1157 /* If we're allowed to talk to a real remote endpoint, then fix things up
1158 * as necessary and proceed.
1160 if (acl_allows_p(connect_real
, sa
)) {
1161 if (fixup_real_ip_socket(sk
, (*sa_r
)->sa_family
, 0)) return (-1);
1165 /* Speaking of which, if we don't have a local address, then we should
1168 if (!sun
->sun_path
[0] && do_implicit_bind(sk
, sa
, ibf
)) return (-1);
1170 /* And then come up with a remote address. */
1171 encode_inet_addr(sun
, sa
, 0);
1173 *len_r
= SUN_LEN(sun
);
1177 /*----- Configuration -----------------------------------------------------*/
1179 /* Return the process owner's home directory. */
1180 static char *home(void)
1185 if (getuid() == uid
&&
1186 (p
= getenv("HOME")) != 0)
1188 else if ((pw
= getpwuid(uid
)) != 0)
1189 return (pw
->pw_dir
);
1194 /* Return a good temporary directory to use. */
1195 static char *tmpdir(void)
1199 if ((p
= getenv("TMPDIR")) != 0) return (p
);
1200 else if ((p
= getenv("TMP")) != 0) return (p
);
1201 else return ("/tmp");
1204 /* Return the user's name, or at least something distinctive. */
1205 static char *user(void)
1207 static char buf
[16];
1211 if ((p
= getenv("USER")) != 0) return (p
);
1212 else if ((p
= getenv("LOGNAME")) != 0) return (p
);
1213 else if ((pw
= getpwuid(uid
)) != 0) return (pw
->pw_name
);
1215 snprintf(buf
, sizeof(buf
), "uid-%lu", (unsigned long)uid
);
1220 /* Skip P over space characters. */
1221 #define SKIPSPC do { while (*p && isspace(UC(*p))) p++; } while (0)
1223 /* Set Q to point to the next word following P, null-terminate it, and step P
1225 #define NEXTWORD(q) do { \
1228 while (*p && !isspace(UC(*p))) p++; \
1232 /* Set Q to point to the next dotted-quad address, store the ending delimiter
1233 * in DEL, null-terminate it, and step P past it. */
1234 static void parse_nextaddr(char **pp
, char **qq
, int *del
)
1242 p
+= strcspn(p
, "]");
1247 while (*p
&& (*p
== '.' || isdigit(UC(*p
)))) p
++;
1254 /* Set Q to point to the next decimal number, store the ending delimiter in
1255 * DEL, null-terminate it, and step P past it. */
1256 #define NEXTNUMBER(q, del) do { \
1259 while (*p && isdigit(UC(*p))) p++; \
1264 /* Push the character DEL back so we scan it again, unless it's zero
1266 #define RESCAN(del) do { if (del) *--p = del; } while (0)
1268 /* Evaluate true if P is pointing to the word KW (and not some longer string
1269 * of which KW is a prefix). */
1271 #define KWMATCHP(kw) (strncmp(p, kw, sizeof(kw) - 1) == 0 && \
1272 !isalnum(UC(p[sizeof(kw) - 1])) && \
1273 (p += sizeof(kw) - 1))
1275 /* Parse a port list, starting at *PP. Port lists have the form
1276 * [:LOW[-HIGH]]: if omitted, all ports are included; if HIGH is omitted,
1277 * it's as if HIGH = LOW. Store LOW in *MIN, HIGH in *MAX and set *PP to the
1278 * rest of the string.
1280 static void parse_ports(char **pp
, unsigned short *min
, unsigned short *max
)
1287 { *min
= 0; *max
= 0xffff; }
1290 NEXTNUMBER(q
, del
); *min
= strtoul(q
, 0, 0); RESCAN(del
);
1293 { p
++; NEXTNUMBER(q
, del
); *max
= strtoul(q
, 0, 0); RESCAN(del
); }
1300 /* Parse an address range designator starting at PP and store a
1301 * representation of it in R. An address range designator has the form:
1303 * any | local | ADDR | ADDR - ADDR | ADDR/ADDR | ADDR/INT
1305 static int parse_addrrange(char **pp
, addrrange
*r
)
1313 if (KWMATCHP("any")) r
->type
= ANY
;
1314 else if (KWMATCHP("local")) r
->type
= LOCAL
;
1316 parse_nextaddr(&p
, &q
, &del
);
1317 af
= guess_address_family(q
);
1318 if (inet_pton(af
, q
, &r
->u
.range
.min
) <= 0) goto bad
;
1323 parse_nextaddr(&p
, &q
, &del
);
1324 if (inet_pton(af
, q
, &r
->u
.range
.max
) <= 0) goto bad
;
1326 } else if (*p
== '/') {
1329 n
= strtoul(q
, 0, 0);
1330 r
->u
.range
.max
= r
->u
.range
.min
;
1331 mask_address(af
, &r
->u
.range
.min
, n
, 0);
1332 mask_address(af
, &r
->u
.range
.max
, n
, 1);
1335 r
->u
.range
.max
= r
->u
.range
.min
;
1346 /* Call FUNC on each individual address range in R. */
1347 static void foreach_addrrange(const addrrange
*r
,
1348 void (*func
)(int af
,
1354 ipaddr minaddr
, maxaddr
;
1361 for (i
= 0; address_families
[i
] >= 0; i
++) {
1362 af
= address_families
[i
];
1363 memset(&minaddr
, 0, sizeof(minaddr
));
1364 maxaddr
= minaddr
; mask_address(af
, &maxaddr
, 0, 1);
1365 func(af
, &minaddr
, &maxaddr
, p
);
1369 for (i
= 0; address_families
[i
] >= 0; i
++) {
1370 af
= address_families
[i
];
1371 memset(&minaddr
, 0, sizeof(minaddr
));
1372 maxaddr
= minaddr
; mask_address(af
, &maxaddr
, 0, 1);
1373 func(af
, &minaddr
, &minaddr
, p
);
1374 func(af
, &maxaddr
, &maxaddr
, p
);
1376 for (i
= 0; i
< n_local_ipaddrs
; i
++) {
1377 func(local_ipaddrs
[i
].af
,
1378 &local_ipaddrs
[i
].addr
, &local_ipaddrs
[i
].addr
,
1383 func(r
->u
.range
.af
, &r
->u
.range
.min
, &r
->u
.range
.max
, p
);
1390 struct add_aclnode_ctx
{
1392 unsigned short minport
, maxport
;
1396 static void add_aclnode(int af
, const ipaddr
*min
, const ipaddr
*max
,
1399 struct add_aclnode_ctx
*ctx
= p
;
1405 a
->minaddr
= *min
; a
->maxaddr
= *max
;
1406 a
->minport
= ctx
->minport
; a
->maxport
= ctx
->maxport
;
1407 **ctx
->tail
= a
; *ctx
->tail
= &a
->next
;
1410 /* Parse an ACL line. *PP points to the end of the line; *TAIL points to
1411 * the list tail (i.e., the final link in the list). An ACL entry has the
1412 * form +|- ADDR-RANGE PORTS
1413 * where PORTS is parsed by parse_ports above; an ACL line consists of a
1414 * comma-separated sequence of entries..
1416 static void parse_acl_line(char **pp
, aclnode
***tail
)
1418 struct add_aclnode_ctx ctx
;
1425 if (*p
== '+') ctx
.act
= ALLOW
;
1426 else if (*p
== '-') ctx
.act
= DENY
;
1430 if (parse_addrrange(&p
, &r
)) goto bad
;
1431 parse_ports(&p
, &ctx
.minport
, &ctx
.maxport
);
1432 foreach_addrrange(&r
, add_aclnode
, &ctx
);
1434 if (*p
!= ',') break;
1442 D( fprintf(stderr
, "noip(%d): bad acl spec (ignored)\n", getpid()); )
1446 /* Parse an ACL from an environment variable VAR, attaching it to the list
1449 static void parse_acl_env(const char *var
, aclnode
***tail
)
1453 if ((p
= getenv(var
)) != 0) {
1455 parse_acl_line(&q
, tail
);
1460 struct add_impbind_ctx
{
1465 static void add_impbind(int af
, const ipaddr
*min
, const ipaddr
*max
,
1468 struct add_impbind_ctx
*ctx
= p
;
1471 if (ctx
->af
&& af
!= ctx
->af
) return;
1475 i
->minaddr
= *min
; i
->maxaddr
= *max
;
1477 case EXPLICIT
: i
->bindaddr
= ctx
->addr
;
1481 *impbind_tail
= i
; impbind_tail
= &i
->next
;
1484 /* Parse an implicit-bind line. An implicit-bind entry has the form
1485 * ADDR-RANGE {ADDR | same}
1487 static void parse_impbind_line(char **pp
)
1489 struct add_impbind_ctx ctx
;
1495 if (parse_addrrange(&p
, &r
)) goto bad
;
1497 if (KWMATCHP("same")) {
1502 parse_nextaddr(&p
, &q
, &del
);
1503 ctx
.af
= guess_address_family(q
);
1504 if (inet_pton(ctx
.af
, q
, &ctx
.addr
) < 0) goto bad
;
1507 foreach_addrrange(&r
, add_impbind
, &ctx
);
1509 if (*p
!= ',') break;
1517 D( fprintf(stderr
, "noip(%d): bad implicit-bind spec (ignored)\n",
1522 /* Parse implicit-bind instructions from an environment variable VAR,
1523 * attaching it to the list.
1525 static void parse_impbind_env(const char *var
)
1529 if ((p
= getenv(var
)) != 0) {
1531 parse_impbind_line(&q
);
1536 /* Parse the autoports configuration directive. Syntax is MIN - MAX. */
1537 static void parse_autoports(char **pp
)
1544 NEXTNUMBER(q
, del
); x
= strtoul(q
, 0, 0); RESCAN(del
);
1546 if (*p
!= '-') goto bad
;
1548 NEXTNUMBER(q
, del
); y
= strtoul(q
, 0, 0); RESCAN(del
);
1549 minautoport
= x
; maxautoport
= y
;
1550 SKIPSPC
; if (*p
) goto bad
;
1555 D( fprintf(stderr
, "noip(%d): bad port range (ignored)\n", getpid()); )
1559 /* Read the configuration from the config file and environment. */
1560 static void readconfig(void)
1568 parse_acl_env("NOIP_REALBIND_BEFORE", &bind_tail
);
1569 parse_acl_env("NOIP_REALCONNECT_BEFORE", &connect_tail
);
1570 parse_impbind_env("NOIP_IMPBIND_BEFORE");
1571 if ((p
= getenv("NOIP_AUTOPORTS")) != 0) {
1573 parse_autoports(&q
);
1576 if ((p
= getenv("NOIP_CONFIG")) == 0)
1577 snprintf(p
= buf
, sizeof(buf
), "%s/.noip", home());
1578 D( fprintf(stderr
, "noip(%d): config file: %s\n", pid
, p
); )
1580 if ((fp
= fopen(p
, "r")) == 0) {
1581 D( fprintf(stderr
, "noip(%d): couldn't read config: %s\n",
1582 pid
, strerror(errno
)); )
1585 while (fgets(buf
, sizeof(buf
), fp
)) {
1590 if (!*p
|| *p
== '#') continue;
1591 while (n
&& isspace(UC(buf
[n
- 1]))) n
--;
1596 if (strcmp(cmd
, "socketdir") == 0)
1597 sockdir
= xstrdup(p
);
1598 else if (strcmp(cmd
, "realbind") == 0)
1599 parse_acl_line(&p
, &bind_tail
);
1600 else if (strcmp(cmd
, "realconnect") == 0)
1601 parse_acl_line(&p
, &connect_tail
);
1602 else if (strcmp(cmd
, "impbind") == 0)
1603 parse_impbind_line(&p
);
1604 else if (strcmp(cmd
, "autoports") == 0)
1605 parse_autoports(&p
);
1606 else if (strcmp(cmd
, "debug") == 0)
1607 debug
= *p ?
atoi(p
) : 1;
1609 D( fprintf(stderr
, "noip(%d): bad config command %s\n", pid
, cmd
); )
1614 parse_acl_env("NOIP_REALBIND", &bind_tail
);
1615 parse_acl_env("NOIP_REALCONNECT", &connect_tail
);
1616 parse_impbind_env("NOIP_IMPBIND");
1617 parse_acl_env("NOIP_REALBIND_AFTER", &bind_tail
);
1618 parse_acl_env("NOIP_REALCONNECT_AFTER", &connect_tail
);
1619 parse_impbind_env("NOIP_IMPBIND_AFTER");
1623 if (!sockdir
) sockdir
= getenv("NOIP_SOCKETDIR");
1625 snprintf(buf
, sizeof(buf
), "%s/noip-%s", tmpdir(), user());
1626 sockdir
= xstrdup(buf
);
1628 D( fprintf(stderr
, "noip(%d): socketdir: %s\n", pid
, sockdir
);
1629 fprintf(stderr
, "noip(%d): autoports: %u-%u\n",
1630 pid
, minautoport
, maxautoport
);
1631 fprintf(stderr
, "noip(%d): realbind acl:\n", pid
);
1632 dump_acl(bind_real
);
1633 fprintf(stderr
, "noip(%d): realconnect acl:\n", pid
);
1634 dump_acl(connect_real
);
1635 fprintf(stderr
, "noip(%d): impbind list:\n", pid
);
1636 dump_impbind_list(); )
1639 /*----- Overridden system calls -------------------------------------------*/
1641 static void dump_syserr(long rc
)
1642 { fprintf(stderr
, " => %ld (E%d)\n", rc
, errno
); }
1644 static void dump_sysresult(long rc
)
1646 if (rc
< 0) dump_syserr(rc
);
1647 else fprintf(stderr
, " => %ld\n", rc
);
1650 static void dump_addrresult(long rc
, const struct sockaddr
*sa
,
1653 char addrbuf
[ADDRBUFSZ
];
1655 if (rc
< 0) dump_syserr(rc
);
1657 fprintf(stderr
, " => %ld [%s]\n", rc
,
1658 present_sockaddr(sa
, len
, addrbuf
, sizeof(addrbuf
)));
1662 int socket(int pf
, int ty
, int proto
)
1666 D( fprintf(stderr
, "noip(%d): SOCKET pf=%d, type=%d, proto=%d",
1667 getpid(), pf
, ty
, proto
); )
1671 if (!family_known_p(pf
)) {
1672 D( fprintf(stderr
, " -> unknown; refuse\n"); )
1673 errno
= EAFNOSUPPORT
;
1676 D( fprintf(stderr
, " -> inet; substitute"); )
1684 D( fprintf(stderr
, " -> safe; permit"); )
1687 sk
= real_socket(pf
, ty
, proto
);
1688 D( dump_sysresult(sk
); )
1692 int socketpair(int pf
, int ty
, int proto
, int *sk
)
1696 D( fprintf(stderr
, "noip(%d): SOCKETPAIR pf=%d, type=%d, proto=%d",
1697 getpid(), pf
, ty
, proto
); )
1698 if (!family_known_p(pf
))
1699 D( fprintf(stderr
, " -> unknown; permit"); )
1701 D( fprintf(stderr
, " -> inet; substitute"); )
1705 rc
= real_socketpair(pf
, ty
, proto
, sk
);
1706 D( if (rc
< 0) dump_syserr(rc
);
1707 else fprintf(stderr
, " => %d (%d, %d)\n", rc
, sk
[0], sk
[1]); )
1711 int bind(int sk
, const struct sockaddr
*sa
, socklen_t len
)
1713 struct sockaddr_un sun
;
1717 D({ char buf
[ADDRBUFSZ
];
1718 fprintf(stderr
, "noip(%d): BIND sk=%d, sa[%d]=%s", pid
,
1719 sk
, len
, present_sockaddr(sa
, len
, buf
, sizeof(buf
))); })
1721 if (!family_known_p(sa
->sa_family
))
1722 D( fprintf(stderr
, " -> unknown af; pass through"); )
1724 D( fprintf(stderr
, " -> checking...\n"); )
1726 if (acl_allows_p(bind_real
, sa
)) {
1727 if (fixup_real_ip_socket(sk
, sa
->sa_family
, 0))
1730 encode_inet_addr(&sun
, sa
, ENCF_FRESH
);
1732 len
= SUN_LEN(&sun
);
1735 D( fprintf(stderr
, "noip(%d): BIND ...", pid
); )
1737 rc
= real_bind(sk
, sa
, len
);
1738 D( dump_sysresult(rc
); )
1742 int connect(int sk
, const struct sockaddr
*sa
, socklen_t len
)
1744 struct sockaddr_un sun
;
1748 D({ char buf
[ADDRBUFSZ
];
1749 fprintf(stderr
, "noip(%d): CONNECT sk=%d, sa[%d]=%s", pid
,
1750 sk
, len
, present_sockaddr(sa
, len
, buf
, sizeof(buf
))); })
1752 if (!family_known_p(sa
->sa_family
)) {
1753 D( fprintf(stderr
, " -> unknown af; pass through"); )
1754 rc
= real_connect(sk
, sa
, len
);
1756 D( fprintf(stderr
, " -> checking...\n"); )
1758 fixup_client_socket(sk
, &sa
, &len
, &sun
);
1760 D( fprintf(stderr
, "noip(%d): CONNECT ...", pid
); )
1761 rc
= real_connect(sk
, sa
, len
);
1764 case ENOENT
: errno
= ECONNREFUSED
; break;
1768 D( dump_sysresult(rc
); )
1772 ssize_t
sendto(int sk
, const void *buf
, size_t len
, int flags
,
1773 const struct sockaddr
*to
, socklen_t tolen
)
1775 struct sockaddr_un sun
;
1779 D({ char addrbuf
[ADDRBUFSZ
];
1780 fprintf(stderr
, "noip(%d): SENDTO sk=%d, len=%lu, flags=%d, to[%d]=%s",
1781 pid
, sk
, (unsigned long)len
, flags
, tolen
,
1782 present_sockaddr(to
, tolen
, addrbuf
, sizeof(addrbuf
))); })
1785 D( fprintf(stderr
, " -> null address; leaving"); )
1786 else if (!family_known_p(to
->sa_family
))
1787 D( fprintf(stderr
, " -> unknown af; pass through"); )
1789 D( fprintf(stderr
, " -> checking...\n"); )
1791 fixup_client_socket(sk
, &to
, &tolen
, &sun
);
1793 D( fprintf(stderr
, "noip(%d): SENDTO ...", pid
); )
1795 n
= real_sendto(sk
, buf
, len
, flags
, to
, tolen
);
1796 D( dump_sysresult(n
); )
1800 ssize_t
recvfrom(int sk
, void *buf
, size_t len
, int flags
,
1801 struct sockaddr
*from
, socklen_t
*fromlen
)
1804 socklen_t mylen
= sizeof(sabuf
);
1808 D( fprintf(stderr
, "noip(%d): RECVFROM sk=%d, len=%lu, flags=%d",
1809 pid
, sk
, (unsigned long)len
, flags
); )
1812 D( fprintf(stderr
, " -> null addr; pass through"); )
1813 n
= real_recvfrom(sk
, buf
, len
, flags
, 0, 0);
1815 n
= real_recvfrom(sk
, buf
, len
, flags
, SA(sabuf
), &mylen
);
1817 D( fprintf(stderr
, " -> converting...\n"); )
1819 return_fake_peer(sk
, SA(sabuf
), mylen
, from
, fromlen
);
1821 D( fprintf(stderr
, "noip(%d): ... RECVFROM", pid
); )
1824 D( dump_addrresult(n
, from
, fromlen ?
*fromlen
: 0); )
1828 ssize_t
sendmsg(int sk
, const struct msghdr
*msg
, int flags
)
1830 struct sockaddr_un sun
;
1831 const struct sockaddr
*sa
= SA(msg
->msg_name
);
1832 struct msghdr mymsg
;
1836 D({ char addrbuf
[ADDRBUFSZ
];
1837 fprintf(stderr
, "noip(%d): SENDMSG sk=%d, "
1838 "msg_flags=%d, msg_name[%d]=%s, ...",
1839 pid
, sk
, msg
->msg_flags
, msg
->msg_namelen
,
1840 present_sockaddr(sa
, msg
->msg_namelen
,
1841 addrbuf
, sizeof(addrbuf
))); })
1844 D( fprintf(stderr
, " -> null address; leaving"); )
1845 else if (!family_known_p(sa
->sa_family
))
1846 D( fprintf(stderr
, " -> unknown af; pass through"); )
1848 D( fprintf(stderr
, " -> checking...\n"); )
1851 fixup_client_socket(sk
, &sa
, &mymsg
.msg_namelen
, &sun
);
1852 mymsg
.msg_name
= SA(sa
);
1855 D( fprintf(stderr
, "noip(%d): SENDMSG ...", pid
); )
1857 n
= real_sendmsg(sk
, msg
, flags
);
1858 D( dump_sysresult(n
); )
1862 ssize_t
recvmsg(int sk
, struct msghdr
*msg
, int flags
)
1865 struct sockaddr
*sa
= SA(msg
->msg_name
);
1866 socklen_t len
= msg
->msg_namelen
;
1870 D( fprintf(stderr
, "noip(%d): RECVMSG sk=%d msg_flags=%d, ...",
1871 pid
, sk
, msg
->msg_flags
); )
1873 if (!msg
->msg_name
) {
1874 D( fprintf(stderr
, " -> null addr; pass through"); )
1875 return (real_recvmsg(sk
, msg
, flags
));
1877 msg
->msg_name
= sabuf
;
1878 msg
->msg_namelen
= sizeof(sabuf
);
1879 n
= real_recvmsg(sk
, msg
, flags
);
1881 D( fprintf(stderr
, " -> converting...\n"); )
1883 return_fake_peer(sk
, SA(sabuf
), msg
->msg_namelen
, sa
, &len
);
1886 D( fprintf(stderr
, "noip(%d): ... RECVMSG", pid
); )
1888 msg
->msg_namelen
= len
;
1890 D( dump_addrresult(n
, sa
, len
); )
1894 int accept(int sk
, struct sockaddr
*sa
, socklen_t
*len
)
1897 socklen_t mylen
= sizeof(sabuf
);
1901 D( fprintf(stderr
, "noip(%d): ACCEPT sk=%d", pid
, sk
); )
1903 nsk
= real_accept(sk
, SA(sabuf
), &mylen
);
1904 if (nsk
< 0) /* failed */;
1905 else if (!sa
) D( fprintf(stderr
, " -> address not wanted"); )
1907 D( fprintf(stderr
, " -> converting...\n"); )
1908 return_fake_peer(sk
, SA(sabuf
), mylen
, sa
, len
);
1909 D( fprintf(stderr
, "noip(%d): ... ACCEPT", pid
); )
1911 D( dump_addrresult(nsk
, sa
, len ?
*len
: 0); )
1915 int getsockname(int sk
, struct sockaddr
*sa
, socklen_t
*len
)
1918 socklen_t mylen
= sizeof(sabuf
);
1922 D( fprintf(stderr
, "noip(%d): GETSOCKNAME sk=%d", pid
, sk
); )
1923 rc
= real_getsockname(sk
, SA(sabuf
), &mylen
);
1925 D( fprintf(stderr
, " -> converting...\n"); )
1926 return_fake_name(SA(sabuf
), mylen
, sa
, len
, 0);
1927 D( fprintf(stderr
, "noip(%d): ... GETSOCKNAME", pid
); )
1929 D( dump_addrresult(rc
, sa
, *len
); )
1933 int getpeername(int sk
, struct sockaddr
*sa
, socklen_t
*len
)
1936 socklen_t mylen
= sizeof(sabuf
);
1940 D( fprintf(stderr
, "noip(%d): GETPEERNAME sk=%d", pid
, sk
); )
1941 rc
= real_getpeername(sk
, SA(sabuf
), &mylen
);
1943 D( fprintf(stderr
, " -> converting...\n"); )
1944 return_fake_peer(sk
, SA(sabuf
), mylen
, sa
, len
);
1945 D( fprintf(stderr
, "noip(%d): ... GETPEERNAME", pid
); )
1947 D( dump_addrresult(rc
, sa
, *len
); )
1951 int getsockopt(int sk
, int lev
, int opt
, void *p
, socklen_t
*len
)
1962 return (real_getsockopt(sk
, lev
, opt
, p
, len
));
1965 int setsockopt(int sk
, int lev
, int opt
, const void *p
, socklen_t len
)
1975 case SO_BINDTODEVICE
:
1976 case SO_ATTACH_FILTER
:
1977 case SO_DETACH_FILTER
:
1980 return (real_setsockopt(sk
, lev
, opt
, p
, len
));
1983 int ioctl(int fd
, unsigned long op
, ...)
1991 arg
= va_arg(ap
, void *);
1995 case SIOCGIFBRDADDR
:
1996 case SIOCGIFDSTADDR
:
1997 case SIOCGIFNETMASK
:
1999 if (fixup_real_ip_socket(fd
, AF_INET
, &sk
)) goto real
;
2001 rc
= real_ioctl(sk
, op
, arg
);
2002 PRESERVING_ERRNO({ close(sk
); });
2006 rc
= real_ioctl(fd
, op
, arg
);
2013 /*----- Initialization ----------------------------------------------------*/
2015 /* Clean up the socket directory, deleting stale sockets. */
2016 static void cleanup_sockdir(void)
2021 struct sockaddr_un sun
;
2025 if ((dir
= opendir(sockdir
)) == 0) return;
2026 sun
.sun_family
= AF_UNIX
;
2027 while ((d
= readdir(dir
)) != 0) {
2028 if (d
->d_name
[0] == '.') continue;
2029 snprintf(sun
.sun_path
, sizeof(sun
.sun_path
),
2030 "%s/%s", sockdir
, d
->d_name
);
2031 if (decode_inet_addr(&addr
.sa
, 0, &sun
, SUN_LEN(&sun
)) ||
2032 stat(sun
.sun_path
, &st
) ||
2033 !S_ISSOCK(st
.st_mode
)) {
2034 D( fprintf(stderr
, "noip(%d): ignoring unknown socketdir entry `%s'\n",
2035 pid
, sun
.sun_path
); )
2038 if (unix_socket_status(&sun
, 0) == STALE
) {
2039 D( fprintf(stderr
, "noip(%d): clearing away stale socket %s\n",
2041 unlink(sun
.sun_path
);
2047 /* Find the addresses attached to local network interfaces, and remember them
2050 static void get_local_ipaddrs(void)
2052 struct ifaddrs
*ifa_head
, *ifa
;
2057 D( fprintf(stderr
, "noip(%d): fetching local addresses...\n", pid
); )
2058 if (getifaddrs(&ifa_head
)) { perror("getifaddrs"); return; }
2059 for (n_local_ipaddrs
= 0, ifa
= ifa_head
;
2060 n_local_ipaddrs
< MAX_LOCAL_IPADDRS
&& ifa
;
2061 ifa
= ifa
->ifa_next
) {
2062 if (!ifa
->ifa_addr
|| !family_known_p(ifa
->ifa_addr
->sa_family
))
2064 ipaddr_from_sockaddr(&a
, ifa
->ifa_addr
);
2065 D({ char buf
[ADDRBUFSZ
];
2066 fprintf(stderr
, "noip(%d): local addr %s = %s", pid
,
2068 inet_ntop(ifa
->ifa_addr
->sa_family
, &a
,
2069 buf
, sizeof(buf
))); })
2070 for (i
= 0; i
< n_local_ipaddrs
; i
++) {
2071 if (ifa
->ifa_addr
->sa_family
== local_ipaddrs
[i
].af
&&
2072 ipaddr_equal_p(local_ipaddrs
[i
].af
, &a
, &local_ipaddrs
[i
].addr
)) {
2073 D( fprintf(stderr
, " (duplicate)\n"); )
2077 D( fprintf(stderr
, "\n"); )
2078 local_ipaddrs
[n_local_ipaddrs
].af
= ifa
->ifa_addr
->sa_family
;
2079 local_ipaddrs
[n_local_ipaddrs
].addr
= a
;
2083 freeifaddrs(ifa_head
);
2086 /* Print the given message to standard error. Avoids stdio. */
2087 static void printerr(const char *p
)
2088 { if (write(STDERR_FILENO
, p
, strlen(p
))) ; }
2090 /* Create the socket directory, being careful about permissions. */
2091 static void create_sockdir(void)
2095 if (lstat(sockdir
, &st
)) {
2096 if (errno
== ENOENT
) {
2097 if (mkdir(sockdir
, 0700)) {
2098 perror("noip: creating socketdir");
2101 if (!lstat(sockdir
, &st
))
2104 perror("noip: checking socketdir");
2108 if (!S_ISDIR(st
.st_mode
)) {
2109 printerr("noip: bad socketdir: not a directory\n");
2112 if (st
.st_uid
!= uid
) {
2113 printerr("noip: bad socketdir: not owner\n");
2116 if (st
.st_mode
& 077) {
2117 printerr("noip: bad socketdir: not private\n");
2122 /* Initialization function. */
2123 static void setup(void) __attribute__((constructor
));
2124 static void setup(void)
2131 if ((p
= getenv("NOIP_DEBUG")) && atoi(p
))
2133 get_local_ipaddrs();
2140 /*----- That's all, folks -------------------------------------------------*/