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>
61 # define SUN_LEN (sun) \
62 (strlen((sun)->sun_path) + offsetof(struct sockaddr_un, sun_path))
65 /*----- Data structures ---------------------------------------------------*/
67 /* Unix socket status values. */
68 #define UNUSED 0u /* No sign of anyone using it */
69 #define STALE 1u /* Socket exists, but is abandoned */
70 #define USED 16u /* Socket is in active use */
71 #define LISTEN 2u /* Socket has an active listener */
73 enum { DENY
, ALLOW
}; /* ACL verdicts */
75 static int address_families
[] = { AF_INET
, AF_INET6
, -1 };
79 /* Address representations. */
80 typedef union ipaddr
{
85 /* Convenient socket address hacking. */
86 typedef union address
{
88 struct sockaddr_in sin
;
89 struct sockaddr_in6 sin6
;
92 /* Access control list nodes */
93 typedef struct aclnode
{
97 ipaddr minaddr
, maxaddr
;
98 unsigned short minport
, maxport
;
101 /* Implicit bind records */
102 typedef struct impbind
{
103 struct impbind
*next
;
105 ipaddr minaddr
, maxaddr
, bindaddr
;
107 enum { EXPLICIT
, SAME
};
109 /* A type for an address range */
110 typedef struct addrrange
{
113 struct { int af
; ipaddr min
, max
; } range
;
116 enum { EMPTY
, ANY
, LOCAL
, RANGE
};
118 /* Local address records */
119 typedef struct full_ipaddr
{
123 #define MAX_LOCAL_IPADDRS 64
124 static full_ipaddr local_ipaddrs
[MAX_LOCAL_IPADDRS
];
125 static int n_local_ipaddrs
;
127 /* General configuration */
129 static char *sockdir
= 0;
130 static int debug
= 0;
131 static unsigned minautoport
= 16384, maxautoport
= 65536;
133 /* Access control lists */
134 static aclnode
*bind_real
, **bind_tail
= &bind_real
;
135 static aclnode
*connect_real
, **connect_tail
= &connect_real
;
136 static impbind
*impbinds
, **impbind_tail
= &impbinds
;
138 /*----- Import the real versions of functions -----------------------------*/
140 /* The list of functions to immport. */
142 _(socket, int, (int, int, int)) \
143 _(socketpair, int, (int, int, int, int *)) \
144 _(connect, int, (int, const struct sockaddr *, socklen_t)) \
145 _(bind, int, (int, const struct sockaddr *, socklen_t)) \
146 _(accept, int, (int, struct sockaddr *, socklen_t *)) \
147 _(getsockname, int, (int, struct sockaddr *, socklen_t *)) \
148 _(getpeername, int, (int, struct sockaddr *, socklen_t *)) \
149 _(getsockopt, int, (int, int, int, void *, socklen_t *)) \
150 _(setsockopt, int, (int, int, int, const void *, socklen_t)) \
151 _(sendto, ssize_t, (int, const void *buf, size_t, int, \
152 const struct sockaddr *to, socklen_t tolen)) \
153 _(recvfrom, ssize_t, (int, void *buf, size_t, int, \
154 struct sockaddr *from, socklen_t *fromlen)) \
155 _(sendmsg, ssize_t, (int, const struct msghdr *, int)) \
156 _(recvmsg, ssize_t, (int, struct msghdr *, int)) \
157 _(ioctl, int, (int, unsigned long, ...))
159 /* Function pointers to set up. */
160 #define DECL(imp, ret, args) static ret (*real_##imp) args;
164 /* Import the system calls. */
165 static void import(void)
167 #define IMPORT(imp, ret, args) \
168 real_##imp = (ret (*)args)dlsym(RTLD_NEXT, #imp);
173 /*----- Utilities ---------------------------------------------------------*/
175 /* Socket address casts */
176 #define SA(sa) ((struct sockaddr *)(sa))
177 #define SIN(sa) ((struct sockaddr_in *)(sa))
178 #define SIN6(sa) ((struct sockaddr_in6 *)(sa))
179 #define SUN(sa) ((struct sockaddr_un *)(sa))
182 #define UC(ch) ((unsigned char)(ch))
184 /* Memory allocation */
185 #define NEW(x) ((x) = xmalloc(sizeof(*x)))
186 #define NEWV(x, n) ((x) = xmalloc(sizeof(*x) * (n)))
190 # define D(body) { if (debug) { body } }
191 # define Dpid pid_t pid = debug ? getpid() : -1
197 /* Preservation of error status */
198 #define PRESERVING_ERRNO(body) do { \
199 int _err = errno; { body } errno = _err; \
202 /* Allocate N bytes of memory; abort on failure. */
203 static void *xmalloc(size_t n
)
207 if ((p
= malloc(n
)) == 0) { perror("malloc"); exit(127); }
211 /* Allocate a copy of the null-terminated string P; abort on failure. */
212 static char *xstrdup(const char *p
)
214 size_t n
= strlen(p
) + 1;
215 char *q
= xmalloc(n
);
220 /*----- Address-type hacking ----------------------------------------------*/
222 /* If M is a simple mask, i.e., consists of a sequence of zero bits followed
223 * by a sequence of one bits, then return the length of the latter sequence
224 * (which may be zero); otherwise return -1.
226 static int simple_mask_length(unsigned long m
)
230 while (m
& 1) { n
++; m
>>= 1; }
234 /* Answer whether AF is an interesting address family. */
235 static int family_known_p(int af
)
246 /* Return the socket address length for address family AF. */
247 static socklen_t
family_socklen(int af
)
250 case AF_INET
: return (sizeof(struct sockaddr_in
));
251 case AF_INET6
: return (sizeof(struct sockaddr_in6
));
256 /* Return the width of addresses of kind AF. */
257 static int address_width(int af
)
260 case AF_INET
: return 32;
261 case AF_INET6
: return 128;
266 /* If addresses A and B share a common prefix then return its length;
267 * otherwise return -1.
269 static int common_prefix_length(int af
, const ipaddr
*a
, const ipaddr
*b
)
273 unsigned long aa
= ntohl(a
->v4
.s_addr
), bb
= ntohl(b
->v4
.s_addr
);
274 unsigned long m
= aa
^bb
;
275 if ((aa
&m
) == 0 && (bb
&m
) == m
) return (32 - simple_mask_length(m
));
279 const uint8_t *aa
= a
->v6
.s6_addr
, *bb
= b
->v6
.s6_addr
;
284 for (i
= 0; i
< 16 && aa
[i
] == bb
[i
]; i
++);
288 if ((aa
[i
]&m
) != 0 || (bb
[i
]&m
) != m
) return (-1);
289 n
+= 8 - simple_mask_length(m
);
290 for (i
++; i
< 16; i
++)
291 if (aa
[i
] || bb
[i
] != 0xff) return (-1);
300 /* Extract the port number (in host byte-order) from SA. */
301 static int port_from_sockaddr(const struct sockaddr
*sa
)
303 switch (sa
->sa_family
) {
304 case AF_INET
: return (ntohs(SIN(sa
)->sin_port
));
305 case AF_INET6
: return (ntohs(SIN6(sa
)->sin6_port
));
310 /* Store the port number PORT (in host byte-order) in SA. */
311 static void port_to_sockaddr(struct sockaddr
*sa
, int port
)
313 switch (sa
->sa_family
) {
314 case AF_INET
: SIN(sa
)->sin_port
= htons(port
); break;
315 case AF_INET6
: SIN6(sa
)->sin6_port
= htons(port
); break;
320 /* Extract the address part from SA and store it in A. */
321 static void ipaddr_from_sockaddr(ipaddr
*a
, const struct sockaddr
*sa
)
323 switch (sa
->sa_family
) {
324 case AF_INET
: a
->v4
= SIN(sa
)->sin_addr
; break;
325 case AF_INET6
: a
->v6
= SIN6(sa
)->sin6_addr
; break;
330 /* Store the address A in SA. */
331 static void ipaddr_to_sockaddr(struct sockaddr
*sa
, const ipaddr
*a
)
333 switch (sa
->sa_family
) {
335 SIN(sa
)->sin_addr
= a
->v4
;
338 SIN6(sa
)->sin6_addr
= a
->v6
;
339 SIN6(sa
)->sin6_scope_id
= 0;
340 SIN6(sa
)->sin6_flowinfo
= 0;
347 /* Copy a whole socket address about. */
348 static void copy_sockaddr(struct sockaddr
*sa_dst
,
349 const struct sockaddr
*sa_src
)
350 { memcpy(sa_dst
, sa_src
, family_socklen(sa_src
->sa_family
)); }
352 /* Convert an AF_INET socket address into the equivalent IPv4-mapped AF_INET6
355 static void map_ipv4_sockaddr(struct sockaddr_in6
*a6
,
356 const struct sockaddr_in
*a4
)
359 in_addr_t a
= ntohl(a4
->sin_addr
.s_addr
);
361 a6
->sin6_family
= AF_INET6
;
362 a6
->sin6_port
= a4
->sin_port
;
363 a6
->sin6_scope_id
= 0;
364 a6
->sin6_flowinfo
= 0;
365 for (i
= 0; i
< 10; i
++) a6
->sin6_addr
.s6_addr
[i
] = 0;
366 for (i
= 10; i
< 12; i
++) a6
->sin6_addr
.s6_addr
[i
] = 0xff;
367 for (i
= 0; i
< 4; i
++) a6
->sin6_addr
.s6_addr
[15 - i
] = (a
>> 8*i
)&0xff;
370 /* Convert an AF_INET6 socket address containing an IPv4-mapped IPv6 address
371 * into the equivalent AF_INET4 address. Return zero on success, or -1 if
372 * the address has the wrong form.
374 static int unmap_ipv4_sockaddr(struct sockaddr_in
*a4
,
375 const struct sockaddr_in6
*a6
)
380 for (i
= 0; i
< 10; i
++) if (a6
->sin6_addr
.s6_addr
[i
] != 0) return (-1);
381 for (i
= 10; i
< 12; i
++) if (a6
->sin6_addr
.s6_addr
[i
] != 0xff) return (-1);
382 for (i
= 0, a
= 0; i
< 4; i
++) a
|= a6
->sin6_addr
.s6_addr
[15 - i
] << 8*i
;
383 a4
->sin_family
= AF_INET
;
384 a4
->sin_port
= a6
->sin6_port
;
385 a4
->sin_addr
.s_addr
= htonl(a
);
389 /* Answer whether two addresses are equal. */
390 static int ipaddr_equal_p(int af
, const ipaddr
*a
, const ipaddr
*b
)
393 case AF_INET
: return (a
->v4
.s_addr
== b
->v4
.s_addr
);
394 case AF_INET6
: return (memcmp(a
->v6
.s6_addr
, b
->v6
.s6_addr
, 16) == 0);
399 /* Answer whether the address part of SA is between A and B (inclusive). We
400 * assume that SA has the correct address family.
402 static int sockaddr_in_range_p(const struct sockaddr
*sa
,
403 const ipaddr
*a
, const ipaddr
*b
)
405 switch (sa
->sa_family
) {
407 unsigned long addr
= ntohl(SIN(sa
)->sin_addr
.s_addr
);
408 return (ntohl(a
->v4
.s_addr
) <= addr
&&
409 addr
<= ntohl(b
->v4
.s_addr
));
412 const uint8_t *ss
= SIN6(sa
)->sin6_addr
.s6_addr
;
413 const uint8_t *aa
= a
->v6
.s6_addr
, *bb
= b
->v6
.s6_addr
;
417 for (i
= 0; h
&& l
&& i
< 16; i
++, ss
++, aa
++, bb
++) {
418 if (*ss
< *aa
|| *bb
< *ss
) return (0);
419 if (*aa
< *ss
) l
= 0;
420 if (*ss
< *bb
) h
= 0;
429 /* Fill in SA with the appropriate wildcard address. */
430 static void wildcard_address(int af
, struct sockaddr
*sa
)
434 struct sockaddr_in
*sin
= SIN(sa
);
435 memset(sin
, 0, sizeof(*sin
));
436 sin
->sin_family
= AF_INET
;
438 sin
->sin_addr
.s_addr
= INADDR_ANY
;
441 struct sockaddr_in6
*sin6
= SIN6(sa
);
442 memset(sin6
, 0, sizeof(*sin6
));
443 sin6
->sin6_family
= AF_INET6
;
445 sin6
->sin6_addr
= in6addr_any
;
446 sin6
->sin6_scope_id
= 0;
447 sin6
->sin6_flowinfo
= 0;
454 /* Mask the address A, forcing all but the top PLEN bits to zero or one
455 * according to HIGHP.
457 static void mask_address(int af
, ipaddr
*a
, int plen
, int highp
)
461 unsigned long addr
= ntohl(a
->v4
.s_addr
);
462 unsigned long mask
= plen ?
~0ul << (32 - plen
) : 0;
464 if (highp
) addr
|= ~mask
;
465 a
->v4
.s_addr
= htonl(addr
& 0xffffffff);
469 unsigned m
= (0xff << (8 - plen
%8)) & 0xff;
470 unsigned s
= highp ?
0xff : 0;
472 a
->v6
.s6_addr
[i
] = (a
->v6
.s6_addr
[i
] & m
) | (s
& ~m
);
475 for (; i
< 16; i
++) a
->v6
.s6_addr
[i
] = s
;
482 /* Write a presentation form of SA to BUF, a buffer of length SZ. LEN is the
483 * address length; if it's zero, look it up based on the address family.
484 * Return a pointer to the string (which might, in an emergency, be a static
485 * string rather than your buffer).
487 static char *present_sockaddr(const struct sockaddr
*sa
, socklen_t len
,
488 char *buf
, size_t sz
)
490 #define WANT(n_) do { if (sz < (n_)) goto nospace; } while (0)
491 #define PUTC(c_) do { *buf++ = (c_); sz--; } while (0)
493 if (!sa
) return "<null-address>";
494 if (!sz
) return "<no-space-in-buffer>";
495 if (!len
) len
= family_socklen(sa
->sa_family
);
497 switch (sa
->sa_family
) {
499 struct sockaddr_un
*sun
= SUN(sa
);
500 char *p
= sun
->sun_path
;
501 size_t n
= len
- offsetof(struct sockaddr_un
, sun_path
);
509 case 0: WANT(2); PUTC('\\'); PUTC('0'); break;
510 case '\a': WANT(2); PUTC('\\'); PUTC('a'); break;
511 case '\n': WANT(2); PUTC('\\'); PUTC('n'); break;
512 case '\r': WANT(2); PUTC('\\'); PUTC('r'); break;
513 case '\t': WANT(2); PUTC('\\'); PUTC('t'); break;
514 case '\v': WANT(2); PUTC('\\'); PUTC('v'); break;
515 case '\\': WANT(2); PUTC('\\'); PUTC('\\'); break;
517 if (*p
> ' ' && *p
<= '~')
518 { WANT(1); PUTC(*p
); }
520 WANT(4); PUTC('\\'); PUTC('x');
521 PUTC((*p
>> 4)&0xf); PUTC((*p
>> 0)&0xf);
528 if (*p
!= '/') { WANT(2); PUTC('.'); PUTC('/'); }
529 while (n
&& *p
) { WANT(1); PUTC(*p
); p
++; n
--; }
533 case AF_INET
: case AF_INET6
: {
534 char addrbuf
[NI_MAXHOST
], portbuf
[NI_MAXSERV
];
535 int err
= getnameinfo(sa
, len
,
536 addrbuf
, sizeof(addrbuf
),
537 portbuf
, sizeof(portbuf
),
538 NI_NUMERICHOST
| NI_NUMERICSERV
);
540 snprintf(buf
, sz
, strchr(addrbuf
, ':') ?
"[%s]:%s" : "%s:%s",
544 snprintf(buf
, sz
, "<unknown-address-family %d>", sa
->sa_family
);
554 /* Guess the family of a textual socket address. */
555 static int guess_address_family(const char *p
)
556 { return (strchr(p
, ':') ? AF_INET6
: AF_INET
); }
558 /* Parse a socket address P and write the result to SA. */
559 static int parse_sockaddr(struct sockaddr
*sa
, const char *p
)
563 struct addrinfo
*ai
, ai_hint
= { 0 };
565 if (strlen(p
) >= sizeof(buf
) - 1) return (-1);
566 strcpy(buf
, p
); p
= buf
;
568 if ((q
= strchr(p
, ':')) == 0) return (-1);
572 if ((q
= strchr(p
, ']')) == 0) return (-1);
574 if (*q
!= ':') return (-1);
578 ai_hint
.ai_family
= AF_UNSPEC
;
579 ai_hint
.ai_socktype
= SOCK_DGRAM
;
580 ai_hint
.ai_flags
= AI_NUMERICHOST
| AI_NUMERICSERV
;
581 if (getaddrinfo(p
, q
, &ai_hint
, &ai
)) return (-1);
582 memcpy(sa
, ai
->ai_addr
, ai
->ai_addrlen
);
587 /*----- Access control lists ----------------------------------------------*/
591 static void dump_addrrange(int af
, const ipaddr
*min
, const ipaddr
*max
)
597 plen
= common_prefix_length(af
, min
, max
);
598 p
= inet_ntop(af
, min
, buf
, sizeof(buf
));
599 fprintf(stderr
, strchr(p
, ':') ?
"[%s]" : "%s", p
);
601 p
= inet_ntop(af
, &max
, buf
, sizeof(buf
));
602 fprintf(stderr
, strchr(p
, ':') ?
"-[%s]" : "-%s", p
);
603 } else if (plen
< address_width(af
))
604 fprintf(stderr
, "/%d", plen
);
607 /* Write to standard error a description of the ACL node A. */
608 static void dump_aclnode(const aclnode
*a
)
610 fprintf(stderr
, "noip(%d): %c ", getpid(), a
->act ?
'+' : '-');
611 dump_addrrange(a
->af
, &a
->minaddr
, &a
->maxaddr
);
612 if (a
->minport
!= 0 || a
->maxport
!= 0xffff) {
613 fprintf(stderr
, ":%u", (unsigned)a
->minport
);
614 if (a
->minport
!= a
->maxport
)
615 fprintf(stderr
, "-%u", (unsigned)a
->maxport
);
620 static void dump_acl(const aclnode
*a
)
624 for (; a
; a
= a
->next
) {
628 fprintf(stderr
, "noip(%d): [default policy: %s]\n", getpid(),
629 act
== ALLOW ?
"DENY" : "ALLOW");
634 /* Returns nonzero if the ACL A allows the socket address SA. */
635 static int acl_allows_p(const aclnode
*a
, const struct sockaddr
*sa
)
637 unsigned short port
= port_from_sockaddr(sa
);
641 D({ char buf
[ADDRBUFSZ
];
642 fprintf(stderr
, "noip(%d): check %s\n", pid
,
643 present_sockaddr(sa
, 0, buf
, sizeof(buf
))); })
644 for (; a
; a
= a
->next
) {
645 D( dump_aclnode(a
); )
646 if (a
->af
== sa
->sa_family
&&
647 sockaddr_in_range_p(sa
, &a
->minaddr
, &a
->maxaddr
) &&
648 a
->minport
<= port
&& port
<= a
->maxport
) {
649 D( fprintf(stderr
, "noip(%d): aha! %s\n", pid
,
650 a
->act ?
"ALLOW" : "DENY"); )
655 D( fprintf(stderr
, "noip(%d): nothing found: %s\n", pid
,
656 act ?
"DENY" : "ALLOW"); )
660 /*----- Socket address conversion -----------------------------------------*/
662 /* Return a uniformly distributed integer between MIN and MAX inclusive. */
663 static unsigned randrange(unsigned min
, unsigned max
)
667 /* It's so nice not to have to care about the quality of the generator
671 for (mask
= 1; mask
< max
; mask
= (mask
<< 1) | 1)
673 do i
= rand() & mask
; while (i
> max
);
677 /* Return the status of Unix-domain socket address SUN. Returns: UNUSED if
678 * the socket doesn't exist; USED if the path refers to an active socket, or
679 * isn't really a socket at all, or we can't tell without a careful search
680 * and QUICKP is set; or STALE if the file refers to a socket which isn't
681 * being used any more.
683 static int unix_socket_status(struct sockaddr_un
*sun
, int quickp
)
692 /* If we can't find the socket node, then it's definitely not in use. If
693 * we get some other error, then this socket is weird.
695 if (stat(sun
->sun_path
, &st
))
696 return (errno
== ENOENT ? UNUSED
: USED
);
698 /* If it's not a socket, then something weird is going on. If we're just
699 * probing quickly to find a spare port, then existence is sufficient to
702 if (!S_ISSOCK(st
.st_mode
) || quickp
)
705 /* The socket's definitely there, but is anyone actually still holding it
706 * open? The only way I know to discover this is to trundle through
707 * `/proc/net/unix'. If there's no entry, then the socket must be stale.
710 if ((fp
= fopen("/proc/net/unix", "r")) == 0)
712 if (!fgets(buf
, sizeof(buf
), fp
)) goto done
; /* skip header */
713 len
= strlen(sun
->sun_path
);
715 while (fgets(buf
, sizeof(buf
), fp
)) {
717 if (n
>= len
+ 2 && buf
[n
- len
- 2] == ' ' && buf
[n
- 1] == '\n' &&
718 memcmp(buf
+ n
- len
- 1, sun
->sun_path
, len
) == 0) {
720 if (sscanf(buf
, "%*s %*x %*x %lx", &f
) < 0 || (f
&0x00010000))
734 /* Encode SA as a Unix-domain address SUN, and return whether it's currently
737 static int encode_single_inet_addr(const struct sockaddr
*sa
,
738 struct sockaddr_un
*sun
,
744 snprintf(sun
->sun_path
, sizeof(sun
->sun_path
), "%s/%s", sockdir
,
745 present_sockaddr(sa
, 0, buf
, sizeof(buf
)));
746 rc
= unix_socket_status(sun
, quickp
);
747 if (rc
== STALE
) unlink(sun
->sun_path
);
751 /* Convert the IP address SA to a Unix-domain address SUN. Fail if the
752 * address seems already taken. If DESPARATEP then try cleaning up stale old
755 static int encode_unused_inet_addr(struct sockaddr
*sa
,
756 struct sockaddr_un
*sun
,
759 address waddr
, maddr
;
760 struct sockaddr_un wsun
;
761 int port
= port_from_sockaddr(sa
);
763 /* First, look for an exact match. Only look quickly unless we're
764 * desperate. If the socket is in use, we fail here. (This could get
765 * racy. Let's not worry about that for now.)
767 if (encode_single_inet_addr(sa
, sun
, !desperatep
)&USED
)
770 /* Next, check the corresponding wildcard address, so as to avoid
771 * inadvertant collisions with listeners. Do this in the same way.
773 wildcard_address(sa
->sa_family
, &waddr
.sa
);
774 port_to_sockaddr(&waddr
.sa
, port
);
775 if (encode_single_inet_addr(&waddr
.sa
, &wsun
, !desperatep
)&USED
)
778 /* We're not done yet. If this is an IPv4 address, then /also/ check (a)
779 * the v6-mapped version, (b) the v6-mapped v4 wildcard, /and/ (c) the v6
782 if (sa
->sa_family
== AF_INET
) {
783 map_ipv4_sockaddr(&maddr
.sin6
, SIN(&sa
));
784 if (encode_single_inet_addr(&maddr
.sa
, &wsun
, !desperatep
)&USED
)
787 map_ipv4_sockaddr(&maddr
.sin6
, &waddr
.sin
);
788 if (encode_single_inet_addr(&maddr
.sa
, &wsun
, !desperatep
)&USED
)
791 wildcard_address(AF_INET6
, &waddr
.sa
);
792 port_to_sockaddr(&waddr
.sa
, port
);
793 if (encode_single_inet_addr(&waddr
.sa
, &wsun
, !desperatep
)&USED
)
801 /* Encode the Internet address SA as a Unix-domain address SUN. If the flag
802 * `ENCF_FRESH' is set, and SA's port number is zero, then we pick an
803 * arbitrary local port. Otherwise we pick the port given. There's an
804 * unpleasant hack to find servers bound to local wildcard addresses.
805 * Returns zero on success; -1 on failure.
807 #define ENCF_FRESH 1u
808 #define ENCF_REUSEADDR 2u
809 static int encode_inet_addr(struct sockaddr_un
*sun
,
810 const struct sockaddr
*sa
,
816 struct sockaddr_in6 sin6
;
817 int port
= port_from_sockaddr(sa
);
821 D( fprintf(stderr
, "noip(%d): encode %s (%s)", getpid(),
822 present_sockaddr(sa
, 0, buf
, sizeof(buf
)),
823 (f
&ENCF_FRESH
) ?
"FRESH" : "EXISTING"); )
825 /* Start making the Unix-domain address. */
826 sun
->sun_family
= AF_UNIX
;
828 if (port
|| !(f
&ENCF_FRESH
)) {
830 /* Try the address as given. If it's in use, or we don't necessarily
831 * want an existing socket, then we're done.
833 rc
= encode_single_inet_addr(sa
, sun
, 0);
834 if ((f
&ENCF_REUSEADDR
) && !(rc
&LISTEN
)) unlink(sun
->sun_path
);
835 if ((rc
&USED
) || (f
&ENCF_FRESH
)) goto found
;
837 /* We're looking for a socket which already exists. This is
838 * unfortunately difficult, because we must deal both with wildcards and
839 * v6-mapped IPv4 addresses.
841 * * We've just tried searching for a socket whose name is an exact
842 * match for our remote address. If the remote address is IPv4, then
843 * we should try again with the v6-mapped equivalent.
845 * * Failing that, we try again with the wildcard address for the
846 * appropriate address family.
848 * * Failing /that/, if the remote address is IPv4, then we try
849 * /again/, increasingly desperately, first with the v6-mapped IPv4
850 * wildcard address, and then with the IPv6 wildcard address. This
851 * will cause magic v6-mapping to occur when the connection is
852 * accepted, which we hope won't cause too much trouble.
855 if (sa
->sa_family
== AF_INET
) {
856 map_ipv4_sockaddr(&addr
.sin6
, SIN(sa
));
857 if (encode_single_inet_addr(&addr
.sa
, sun
, 0)&USED
) goto found
;
860 wildcard_address(sa
->sa_family
, &addr
.sa
);
861 port_to_sockaddr(&addr
.sa
, port
);
862 if (encode_single_inet_addr(&addr
.sa
, sun
, 0)&USED
) goto found
;
864 if (sa
->sa_family
== AF_INET
) {
865 map_ipv4_sockaddr(&sin6
, &addr
.sin
);
866 if (encode_single_inet_addr(SA(&sin6
), sun
, 0)&USED
) goto found
;
867 wildcard_address(AF_INET6
, &addr
.sa
);
868 port_to_sockaddr(&addr
.sa
, port
);
869 if (encode_single_inet_addr(&addr
.sa
, sun
, 0)&USED
) goto found
;
872 /* Well, this isn't going to work (unless a miraculous race is lost), but
873 * we might as well try.
875 encode_single_inet_addr(sa
, sun
, 1);
878 /* We want a fresh new socket. */
880 /* Make a copy of the given address, because we're going to mangle it. */
881 copy_sockaddr(&addr
.sa
, sa
);
883 /* Try a few random-ish port numbers to see if any of them is spare. */
884 for (i
= 0; i
< 10; i
++) {
885 port_to_sockaddr(&addr
.sa
, randrange(minautoport
, maxautoport
));
886 if (!encode_unused_inet_addr(&addr
.sa
, sun
, 0)) goto found
;
889 /* Things must be getting tight. Work through all of the autoport range
890 * to see if we can find a spare one. The first time, just do it the
891 * quick way; if that doesn't work, then check harder for stale sockets.
893 for (desperatep
= 0; desperatep
< 2; desperatep
++) {
894 for (i
= minautoport
; i
<= maxautoport
; i
++) {
895 port_to_sockaddr(&addr
.sa
, i
);
896 if (!encode_unused_inet_addr(&addr
.sa
, sun
, 0)) goto found
;
900 /* We failed to find any free ports. */
902 D( fprintf(stderr
, " -- can't resolve\n"); )
908 D( fprintf(stderr
, " -> `%s'\n", sun
->sun_path
); )
912 /* Decode the Unix address SUN to an Internet address SIN. If AF_HINT is
913 * nonzero, an empty address (indicative of an unbound Unix-domain socket) is
914 * translated to a wildcard Internet address of the appropriate family.
915 * Returns zero on success; -1 on failure (e.g., it wasn't one of our
918 static int decode_inet_addr(struct sockaddr
*sa
, int af_hint
,
919 const struct sockaddr_un
*sun
,
923 size_t n
= strlen(sockdir
), nn
;
926 if (!sa
) sa
= &addr
.sa
;
927 if (sun
->sun_family
!= AF_UNIX
) return (-1);
928 if (len
> sizeof(*sun
)) return (-1);
929 ((char *)sun
)[len
] = 0;
930 nn
= strlen(sun
->sun_path
);
931 D( fprintf(stderr
, "noip(%d): decode `%s'", getpid(), sun
->sun_path
); )
932 if (af_hint
&& !sun
->sun_path
[0]) {
933 wildcard_address(af_hint
, sa
);
934 D( fprintf(stderr
, " -- unbound socket\n"); )
937 if (nn
< n
+ 1 || nn
- n
>= sizeof(buf
) || sun
->sun_path
[n
] != '/' ||
938 memcmp(sun
->sun_path
, sockdir
, n
) != 0) {
939 D( fprintf(stderr
, " -- not one of ours\n"); )
942 if (parse_sockaddr(sa
, sun
->sun_path
+ n
+ 1)) return (-1);
943 D( fprintf(stderr
, " -> %s\n",
944 present_sockaddr(sa
, 0, buf
, sizeof(buf
))); )
948 /* SK is (or at least might be) a Unix-domain socket we created when an
949 * Internet socket was asked for. We've decided it should be an Internet
950 * socket after all, with family AF_HINT, so convert it. If TMP is not null,
951 * then don't replace the existing descriptor: store the new socket in *TMP
954 static int fixup_real_ip_socket(int sk
, int af_hint
, int *tmp
)
959 struct sockaddr_un sun
;
972 _(LINGER, struct linger) \
975 _(RCVTIMEO, struct timeval) \
976 _(SNDTIMEO, struct timeval)
979 if (real_getsockname(sk
, SA(&sun
), &len
))
981 if (decode_inet_addr(&addr
.sa
, af_hint
, &sun
, len
))
982 return (0); /* Not one of ours */
984 if (real_getsockopt(sk
, SOL_SOCKET
, SO_TYPE
, &type
, &len
) < 0 ||
985 (nsk
= real_socket(addr
.sa
.sa_family
, type
, 0)) < 0)
987 #define FIX(opt, ty) do { \
990 if (real_getsockopt(sk, SOL_SOCKET, SO_##opt, &ov_, &len) < 0 || \
991 real_setsockopt(nsk, SOL_SOCKET, SO_##opt, &ov_, len)) { \
1001 if ((f
= fcntl(sk
, F_GETFL
)) < 0 ||
1002 (fd
= fcntl(sk
, F_GETFD
)) < 0 ||
1003 fcntl(nsk
, F_SETFL
, f
) < 0 ||
1004 dup2(nsk
, sk
) < 0) {
1008 unlink(sun
.sun_path
);
1010 if (fcntl(sk
, F_SETFD
, fd
) < 0) {
1011 perror("noip: fixup_real_ip_socket F_SETFD");
1018 /* We found the real address SA, with length LEN; if it's a Unix-domain
1019 * address corresponding to a fake socket, convert it to cover up the
1020 * deception. Whatever happens, put the result at FAKE and store its length
1023 #define FNF_V6MAPPED 1u
1024 static void return_fake_name(struct sockaddr
*sa
, socklen_t len
,
1025 struct sockaddr
*fake
, socklen_t
*fakelen
,
1029 struct sockaddr_in6 sin6
;
1032 if (sa
->sa_family
== AF_UNIX
&&
1033 !decode_inet_addr(&addr
.sa
, 0, SUN(sa
), len
)) {
1034 if (addr
.sa
.sa_family
!= AF_INET
|| !(f
&FNF_V6MAPPED
)) {
1036 len
= family_socklen(addr
.sa
.sa_family
);
1038 map_ipv4_sockaddr(&sin6
, &addr
.sin
);
1040 len
= family_socklen(AF_INET6
);
1044 if (len
> *fakelen
) len
= *fakelen
;
1045 if (len
> 0) memcpy(fake
, sa
, len
);
1049 /* Variant of `return_fake_name' above, specifically handling the weirdness
1050 * of remote v6-mapped IPv4 addresses. If SK's fake local address is IPv6,
1051 * and the remote address is IPv4, then return a v6-mapped version of the
1054 static void return_fake_peer(int sk
, struct sockaddr
*sa
, socklen_t len
,
1055 struct sockaddr
*fake
, socklen_t
*fakelen
)
1058 socklen_t mylen
= sizeof(sabuf
);
1064 rc
= real_getsockname(sk
, SA(sabuf
), &mylen
);
1065 if (!rc
&& sa
->sa_family
== AF_UNIX
&&
1066 !decode_inet_addr(&addr
.sa
, 0, SUN(sabuf
), mylen
) &&
1067 addr
.sa
.sa_family
== AF_INET6
)
1068 fnf
|= FNF_V6MAPPED
;
1070 return_fake_name(sa
, len
, fake
, fakelen
, fnf
);
1073 /*----- Implicit binding --------------------------------------------------*/
1077 static void dump_impbind(const impbind
*i
)
1079 char buf
[ADDRBUFSZ
];
1081 fprintf(stderr
, "noip(%d): ", getpid());
1082 dump_addrrange(i
->af
, &i
->minaddr
, &i
->maxaddr
);
1084 case SAME
: fprintf(stderr
, " <self>"); break;
1086 fprintf(stderr
, " %s", inet_ntop(i
->af
, &i
->bindaddr
,
1091 fputc('\n', stderr
);
1094 static void dump_impbind_list(void)
1098 for (i
= impbinds
; i
; i
= i
->next
) dump_impbind(i
);
1103 /* The socket SK is about to be used to communicate with the remote address
1104 * SA. Assign it a local address so that getpeername(2) does something
1107 * If the flag `IBF_V6MAPPED' is set then, then SA must be an `AF_INET'
1108 * address; after deciding on the appropriate local address, convert it to be
1109 * an IPv4-mapped IPv6 address before final conversion to a Unix-domain
1110 * socket address and actually binding. Note that this could well mean that
1111 * the socket ends up bound to the v6-mapped v4 wildcard address
1112 * ::ffff:0.0.0.0, which looks very strange but is meaningful.
1114 #define IBF_V6MAPPED 1u
1115 static int do_implicit_bind(int sk
, const struct sockaddr
*sa
, unsigned f
)
1118 struct sockaddr_in6 sin6
;
1119 struct sockaddr_un sun
;
1123 D( fprintf(stderr
, "noip(%d): checking impbind list...\n", pid
); )
1124 for (i
= impbinds
; i
; i
= i
->next
) {
1125 D( dump_impbind(i
); )
1126 if (sa
->sa_family
== i
->af
&&
1127 sockaddr_in_range_p(sa
, &i
->minaddr
, &i
->maxaddr
)) {
1128 D( fprintf(stderr
, "noip(%d): match!\n", pid
); )
1129 addr
.sa
.sa_family
= sa
->sa_family
;
1131 case EXPLICIT
: ipaddr_to_sockaddr(&addr
.sa
, &i
->bindaddr
); break;
1132 case SAME
: copy_sockaddr(&addr
.sa
, sa
); break;
1134 port_to_sockaddr(&addr
.sa
, 0);
1138 D( fprintf(stderr
, "noip(%d): no match; using wildcard\n", pid
); )
1139 wildcard_address(sa
->sa_family
, &addr
.sa
);
1141 if (addr
.sa
.sa_family
!= AF_INET
|| !(f
&IBF_V6MAPPED
)) sa
= &addr
.sa
;
1142 else { map_ipv4_sockaddr(&sin6
, &addr
.sin
); sa
= SA(&sin6
); }
1143 encode_inet_addr(&sun
, sa
, ENCF_FRESH
);
1144 D( fprintf(stderr
, "noip(%d): implicitly binding to %s\n",
1145 pid
, sun
.sun_path
); )
1146 if (real_bind(sk
, SA(&sun
), SUN_LEN(&sun
))) return (-1);
1150 /* The socket SK is about to communicate with the remote address *SA. Ensure
1151 * that the socket has a local address, and adjust *SA to refer to the real
1154 * If we need to translate the remote address, then the Unix-domain endpoint
1155 * address will end in *SUN, and *SA will be adjusted to point to it.
1157 static int fixup_client_socket(int sk
, const struct sockaddr
**sa_r
,
1158 socklen_t
*len_r
, struct sockaddr_un
*sun
)
1160 struct sockaddr_in sin
;
1161 socklen_t mylen
= sizeof(*sun
);
1162 const struct sockaddr
*sa
= *sa_r
;
1165 /* If this isn't a Unix-domain socket then there's nothing to do. */
1166 if (real_getsockname(sk
, SA(sun
), &mylen
) < 0) return (-1);
1167 if (sun
->sun_family
!= AF_UNIX
) return (0);
1168 if (mylen
< sizeof(*sun
)) ((char *)sun
)[mylen
] = 0;
1170 /* If the remote address is v6-mapped IPv4, then unmap it so as to search
1171 * for IPv4 servers. Also remember to v6-map the local address when we
1174 if (sa
->sa_family
== AF_INET6
&& !(unmap_ipv4_sockaddr(&sin
, SIN6(sa
)))) {
1176 ibf
|= IBF_V6MAPPED
;
1179 /* If we're allowed to talk to a real remote endpoint, then fix things up
1180 * as necessary and proceed.
1182 if (acl_allows_p(connect_real
, sa
)) {
1183 if (fixup_real_ip_socket(sk
, (*sa_r
)->sa_family
, 0)) return (-1);
1187 /* Speaking of which, if we don't have a local address, then we should
1190 if (!sun
->sun_path
[0] && do_implicit_bind(sk
, sa
, ibf
)) return (-1);
1192 /* And then come up with a remote address. */
1193 encode_inet_addr(sun
, sa
, 0);
1195 *len_r
= SUN_LEN(sun
);
1199 /*----- Configuration -----------------------------------------------------*/
1201 /* Return the process owner's home directory. */
1202 static char *home(void)
1207 if (getuid() == uid
&&
1208 (p
= getenv("HOME")) != 0)
1210 else if ((pw
= getpwuid(uid
)) != 0)
1211 return (pw
->pw_dir
);
1216 /* Return a good temporary directory to use. */
1217 static char *tmpdir(void)
1221 if ((p
= getenv("TMPDIR")) != 0) return (p
);
1222 else if ((p
= getenv("TMP")) != 0) return (p
);
1223 else return ("/tmp");
1226 /* Return the user's name, or at least something distinctive. */
1227 static char *user(void)
1229 static char buf
[16];
1233 if ((p
= getenv("USER")) != 0) return (p
);
1234 else if ((p
= getenv("LOGNAME")) != 0) return (p
);
1235 else if ((pw
= getpwuid(uid
)) != 0) return (pw
->pw_name
);
1237 snprintf(buf
, sizeof(buf
), "uid-%lu", (unsigned long)uid
);
1242 /* Skip P over space characters. */
1243 #define SKIPSPC do { while (*p && isspace(UC(*p))) p++; } while (0)
1245 /* Set Q to point to the next word following P, null-terminate it, and step P
1247 #define NEXTWORD(q) do { \
1250 while (*p && !isspace(UC(*p))) p++; \
1254 /* Set Q to point to the next dotted-quad address, store the ending delimiter
1255 * in DEL, null-terminate it, and step P past it. */
1256 static void parse_nextaddr(char **pp
, char **qq
, int *del
)
1264 p
+= strcspn(p
, "]");
1269 while (*p
&& (*p
== '.' || isdigit(UC(*p
)))) p
++;
1276 /* Set Q to point to the next decimal number, store the ending delimiter in
1277 * DEL, null-terminate it, and step P past it. */
1278 #define NEXTNUMBER(q, del) do { \
1281 while (*p && isdigit(UC(*p))) p++; \
1286 /* Push the character DEL back so we scan it again, unless it's zero
1288 #define RESCAN(del) do { if (del) *--p = del; } while (0)
1290 /* Evaluate true if P is pointing to the word KW (and not some longer string
1291 * of which KW is a prefix). */
1293 #define KWMATCHP(kw) (strncmp(p, kw, sizeof(kw) - 1) == 0 && \
1294 !isalnum(UC(p[sizeof(kw) - 1])) && \
1295 (p += sizeof(kw) - 1))
1297 /* Parse a port list, starting at *PP. Port lists have the form
1298 * [:LOW[-HIGH]]: if omitted, all ports are included; if HIGH is omitted,
1299 * it's as if HIGH = LOW. Store LOW in *MIN, HIGH in *MAX and set *PP to the
1300 * rest of the string.
1302 static void parse_ports(char **pp
, unsigned short *min
, unsigned short *max
)
1309 { *min
= 0; *max
= 0xffff; }
1312 NEXTNUMBER(q
, del
); *min
= strtoul(q
, 0, 0); RESCAN(del
);
1315 { p
++; NEXTNUMBER(q
, del
); *max
= strtoul(q
, 0, 0); RESCAN(del
); }
1322 /* Parse an address range designator starting at PP and store a
1323 * representation of it in R. An address range designator has the form:
1325 * any | local | ADDR | ADDR - ADDR | ADDR/ADDR | ADDR/INT
1327 static int parse_addrrange(char **pp
, addrrange
*r
)
1335 if (KWMATCHP("any")) r
->type
= ANY
;
1336 else if (KWMATCHP("local")) r
->type
= LOCAL
;
1338 parse_nextaddr(&p
, &q
, &del
);
1339 af
= guess_address_family(q
);
1340 if (inet_pton(af
, q
, &r
->u
.range
.min
) <= 0) goto bad
;
1345 parse_nextaddr(&p
, &q
, &del
);
1346 if (inet_pton(af
, q
, &r
->u
.range
.max
) <= 0) goto bad
;
1348 } else if (*p
== '/') {
1351 n
= strtoul(q
, 0, 0);
1352 r
->u
.range
.max
= r
->u
.range
.min
;
1353 mask_address(af
, &r
->u
.range
.min
, n
, 0);
1354 mask_address(af
, &r
->u
.range
.max
, n
, 1);
1357 r
->u
.range
.max
= r
->u
.range
.min
;
1368 /* Call FUNC on each individual address range in R. */
1369 static void foreach_addrrange(const addrrange
*r
,
1370 void (*func
)(int af
,
1376 ipaddr minaddr
, maxaddr
;
1383 for (i
= 0; address_families
[i
] >= 0; i
++) {
1384 af
= address_families
[i
];
1385 memset(&minaddr
, 0, sizeof(minaddr
));
1386 maxaddr
= minaddr
; mask_address(af
, &maxaddr
, 0, 1);
1387 func(af
, &minaddr
, &maxaddr
, p
);
1391 for (i
= 0; address_families
[i
] >= 0; i
++) {
1392 af
= address_families
[i
];
1393 memset(&minaddr
, 0, sizeof(minaddr
));
1394 maxaddr
= minaddr
; mask_address(af
, &maxaddr
, 0, 1);
1395 func(af
, &minaddr
, &minaddr
, p
);
1396 func(af
, &maxaddr
, &maxaddr
, p
);
1398 for (i
= 0; i
< n_local_ipaddrs
; i
++) {
1399 func(local_ipaddrs
[i
].af
,
1400 &local_ipaddrs
[i
].addr
, &local_ipaddrs
[i
].addr
,
1405 func(r
->u
.range
.af
, &r
->u
.range
.min
, &r
->u
.range
.max
, p
);
1412 struct add_aclnode_ctx
{
1414 unsigned short minport
, maxport
;
1418 static void add_aclnode(int af
, const ipaddr
*min
, const ipaddr
*max
,
1421 struct add_aclnode_ctx
*ctx
= p
;
1427 a
->minaddr
= *min
; a
->maxaddr
= *max
;
1428 a
->minport
= ctx
->minport
; a
->maxport
= ctx
->maxport
;
1429 **ctx
->tail
= a
; *ctx
->tail
= &a
->next
;
1432 /* Parse an ACL line. *PP points to the end of the line; *TAIL points to
1433 * the list tail (i.e., the final link in the list). An ACL entry has the
1434 * form +|- ADDR-RANGE PORTS
1435 * where PORTS is parsed by parse_ports above; an ACL line consists of a
1436 * comma-separated sequence of entries..
1438 static void parse_acl_line(char **pp
, aclnode
***tail
)
1440 struct add_aclnode_ctx ctx
;
1447 if (*p
== '+') ctx
.act
= ALLOW
;
1448 else if (*p
== '-') ctx
.act
= DENY
;
1452 if (parse_addrrange(&p
, &r
)) goto bad
;
1453 parse_ports(&p
, &ctx
.minport
, &ctx
.maxport
);
1454 foreach_addrrange(&r
, add_aclnode
, &ctx
);
1456 if (*p
!= ',') break;
1464 D( fprintf(stderr
, "noip(%d): bad acl spec (ignored)\n", getpid()); )
1468 /* Parse an ACL from an environment variable VAR, attaching it to the list
1471 static void parse_acl_env(const char *var
, aclnode
***tail
)
1475 if ((p
= getenv(var
)) != 0) {
1477 parse_acl_line(&q
, tail
);
1482 struct add_impbind_ctx
{
1487 static void add_impbind(int af
, const ipaddr
*min
, const ipaddr
*max
,
1490 struct add_impbind_ctx
*ctx
= p
;
1493 if (ctx
->af
&& af
!= ctx
->af
) return;
1497 i
->minaddr
= *min
; i
->maxaddr
= *max
;
1499 case EXPLICIT
: i
->bindaddr
= ctx
->addr
;
1503 *impbind_tail
= i
; impbind_tail
= &i
->next
;
1506 /* Parse an implicit-bind line. An implicit-bind entry has the form
1507 * ADDR-RANGE {ADDR | same}
1509 static void parse_impbind_line(char **pp
)
1511 struct add_impbind_ctx ctx
;
1517 if (parse_addrrange(&p
, &r
)) goto bad
;
1519 if (KWMATCHP("same")) {
1524 parse_nextaddr(&p
, &q
, &del
);
1525 ctx
.af
= guess_address_family(q
);
1526 if (inet_pton(ctx
.af
, q
, &ctx
.addr
) < 0) goto bad
;
1529 foreach_addrrange(&r
, add_impbind
, &ctx
);
1531 if (*p
!= ',') break;
1539 D( fprintf(stderr
, "noip(%d): bad implicit-bind spec (ignored)\n",
1544 /* Parse implicit-bind instructions from an environment variable VAR,
1545 * attaching it to the list.
1547 static void parse_impbind_env(const char *var
)
1551 if ((p
= getenv(var
)) != 0) {
1553 parse_impbind_line(&q
);
1558 /* Parse the autoports configuration directive. Syntax is MIN - MAX. */
1559 static void parse_autoports(char **pp
)
1566 NEXTNUMBER(q
, del
); x
= strtoul(q
, 0, 0); RESCAN(del
);
1568 if (*p
!= '-') goto bad
;
1570 NEXTNUMBER(q
, del
); y
= strtoul(q
, 0, 0); RESCAN(del
);
1571 minautoport
= x
; maxautoport
= y
;
1572 SKIPSPC
; if (*p
) goto bad
;
1577 D( fprintf(stderr
, "noip(%d): bad port range (ignored)\n", getpid()); )
1581 /* Read the configuration from the config file and environment. */
1582 static void readconfig(void)
1590 parse_acl_env("NOIP_REALBIND_BEFORE", &bind_tail
);
1591 parse_acl_env("NOIP_REALCONNECT_BEFORE", &connect_tail
);
1592 parse_impbind_env("NOIP_IMPBIND_BEFORE");
1593 if ((p
= getenv("NOIP_AUTOPORTS")) != 0) {
1595 parse_autoports(&q
);
1598 if ((p
= getenv("NOIP_CONFIG")) == 0)
1599 snprintf(p
= buf
, sizeof(buf
), "%s/.noip", home());
1600 D( fprintf(stderr
, "noip(%d): config file: %s\n", pid
, p
); )
1602 if ((fp
= fopen(p
, "r")) == 0) {
1603 D( fprintf(stderr
, "noip(%d): couldn't read config: %s\n",
1604 pid
, strerror(errno
)); )
1607 while (fgets(buf
, sizeof(buf
), fp
)) {
1612 if (!*p
|| *p
== '#') continue;
1613 while (n
&& isspace(UC(buf
[n
- 1]))) n
--;
1618 if (strcmp(cmd
, "socketdir") == 0)
1619 sockdir
= xstrdup(p
);
1620 else if (strcmp(cmd
, "realbind") == 0)
1621 parse_acl_line(&p
, &bind_tail
);
1622 else if (strcmp(cmd
, "realconnect") == 0)
1623 parse_acl_line(&p
, &connect_tail
);
1624 else if (strcmp(cmd
, "impbind") == 0)
1625 parse_impbind_line(&p
);
1626 else if (strcmp(cmd
, "autoports") == 0)
1627 parse_autoports(&p
);
1628 else if (strcmp(cmd
, "debug") == 0)
1629 debug
= *p ?
atoi(p
) : 1;
1631 D( fprintf(stderr
, "noip(%d): bad config command %s\n", pid
, cmd
); )
1636 parse_acl_env("NOIP_REALBIND", &bind_tail
);
1637 parse_acl_env("NOIP_REALCONNECT", &connect_tail
);
1638 parse_impbind_env("NOIP_IMPBIND");
1639 parse_acl_env("NOIP_REALBIND_AFTER", &bind_tail
);
1640 parse_acl_env("NOIP_REALCONNECT_AFTER", &connect_tail
);
1641 parse_impbind_env("NOIP_IMPBIND_AFTER");
1645 if (!sockdir
) sockdir
= getenv("NOIP_SOCKETDIR");
1647 snprintf(buf
, sizeof(buf
), "%s/noip-%s", tmpdir(), user());
1648 sockdir
= xstrdup(buf
);
1650 D( fprintf(stderr
, "noip(%d): socketdir: %s\n", pid
, sockdir
);
1651 fprintf(stderr
, "noip(%d): autoports: %u-%u\n",
1652 pid
, minautoport
, maxautoport
);
1653 fprintf(stderr
, "noip(%d): realbind acl:\n", pid
);
1654 dump_acl(bind_real
);
1655 fprintf(stderr
, "noip(%d): realconnect acl:\n", pid
);
1656 dump_acl(connect_real
);
1657 fprintf(stderr
, "noip(%d): impbind list:\n", pid
);
1658 dump_impbind_list(); )
1661 /*----- Overridden system calls -------------------------------------------*/
1663 static void dump_syserr(long rc
)
1664 { fprintf(stderr
, " => %ld (E%d)\n", rc
, errno
); }
1666 static void dump_sysresult(long rc
)
1668 if (rc
< 0) dump_syserr(rc
);
1669 else fprintf(stderr
, " => %ld\n", rc
);
1672 static void dump_addrresult(long rc
, const struct sockaddr
*sa
,
1675 char addrbuf
[ADDRBUFSZ
];
1677 if (rc
< 0) dump_syserr(rc
);
1679 fprintf(stderr
, " => %ld [%s]\n", rc
,
1680 present_sockaddr(sa
, len
, addrbuf
, sizeof(addrbuf
)));
1684 int socket(int pf
, int ty
, int proto
)
1688 D( fprintf(stderr
, "noip(%d): SOCKET pf=%d, type=%d, proto=%d",
1689 getpid(), pf
, ty
, proto
); )
1693 if (!family_known_p(pf
)) {
1694 D( fprintf(stderr
, " -> unknown; refuse\n"); )
1695 errno
= EAFNOSUPPORT
;
1698 D( fprintf(stderr
, " -> inet; substitute"); )
1706 D( fprintf(stderr
, " -> safe; permit"); )
1709 sk
= real_socket(pf
, ty
, proto
);
1710 D( dump_sysresult(sk
); )
1714 int socketpair(int pf
, int ty
, int proto
, int *sk
)
1718 D( fprintf(stderr
, "noip(%d): SOCKETPAIR pf=%d, type=%d, proto=%d",
1719 getpid(), pf
, ty
, proto
); )
1720 if (!family_known_p(pf
))
1721 D( fprintf(stderr
, " -> unknown; permit"); )
1723 D( fprintf(stderr
, " -> inet; substitute"); )
1727 rc
= real_socketpair(pf
, ty
, proto
, sk
);
1728 D( if (rc
< 0) dump_syserr(rc
);
1729 else fprintf(stderr
, " => %d (%d, %d)\n", rc
, sk
[0], sk
[1]); )
1733 int bind(int sk
, const struct sockaddr
*sa
, socklen_t len
)
1735 struct sockaddr_un sun
;
1742 D({ char buf
[ADDRBUFSZ
];
1743 fprintf(stderr
, "noip(%d): BIND sk=%d, sa[%d]=%s", pid
,
1744 sk
, len
, present_sockaddr(sa
, len
, buf
, sizeof(buf
))); })
1746 if (!family_known_p(sa
->sa_family
))
1747 D( fprintf(stderr
, " -> unknown af; pass through"); )
1749 D( fprintf(stderr
, " -> checking...\n"); )
1751 if (acl_allows_p(bind_real
, sa
)) {
1752 if (fixup_real_ip_socket(sk
, sa
->sa_family
, 0))
1757 if (!getsockopt(sk
, SOL_SOCKET
, SO_REUSEADDR
, &reusep
, &n
) && reusep
)
1758 f
|= ENCF_REUSEADDR
;
1759 encode_inet_addr(&sun
, sa
, f
);
1761 len
= SUN_LEN(&sun
);
1764 D( fprintf(stderr
, "noip(%d): BIND ...", pid
); )
1766 rc
= real_bind(sk
, sa
, len
);
1767 D( dump_sysresult(rc
); )
1771 int connect(int sk
, const struct sockaddr
*sa
, socklen_t len
)
1773 struct sockaddr_un sun
;
1777 D({ char buf
[ADDRBUFSZ
];
1778 fprintf(stderr
, "noip(%d): CONNECT sk=%d, sa[%d]=%s", pid
,
1779 sk
, len
, present_sockaddr(sa
, len
, buf
, sizeof(buf
))); })
1781 if (!family_known_p(sa
->sa_family
)) {
1782 D( fprintf(stderr
, " -> unknown af; pass through"); )
1783 rc
= real_connect(sk
, sa
, len
);
1785 D( fprintf(stderr
, " -> checking...\n"); )
1787 fixup_client_socket(sk
, &sa
, &len
, &sun
);
1789 D( fprintf(stderr
, "noip(%d): CONNECT ...", pid
); )
1790 rc
= real_connect(sk
, sa
, len
);
1793 case ENOENT
: errno
= ECONNREFUSED
; break;
1797 D( dump_sysresult(rc
); )
1801 ssize_t
sendto(int sk
, const void *buf
, size_t len
, int flags
,
1802 const struct sockaddr
*to
, socklen_t tolen
)
1804 struct sockaddr_un sun
;
1808 D({ char addrbuf
[ADDRBUFSZ
];
1809 fprintf(stderr
, "noip(%d): SENDTO sk=%d, len=%lu, flags=%d, to[%d]=%s",
1810 pid
, sk
, (unsigned long)len
, flags
, tolen
,
1811 present_sockaddr(to
, tolen
, addrbuf
, sizeof(addrbuf
))); })
1814 D( fprintf(stderr
, " -> null address; leaving"); )
1815 else if (!family_known_p(to
->sa_family
))
1816 D( fprintf(stderr
, " -> unknown af; pass through"); )
1818 D( fprintf(stderr
, " -> checking...\n"); )
1820 fixup_client_socket(sk
, &to
, &tolen
, &sun
);
1822 D( fprintf(stderr
, "noip(%d): SENDTO ...", pid
); )
1824 n
= real_sendto(sk
, buf
, len
, flags
, to
, tolen
);
1825 D( dump_sysresult(n
); )
1829 ssize_t
recvfrom(int sk
, void *buf
, size_t len
, int flags
,
1830 struct sockaddr
*from
, socklen_t
*fromlen
)
1833 socklen_t mylen
= sizeof(sabuf
);
1837 D( fprintf(stderr
, "noip(%d): RECVFROM sk=%d, len=%lu, flags=%d",
1838 pid
, sk
, (unsigned long)len
, flags
); )
1841 D( fprintf(stderr
, " -> null addr; pass through"); )
1842 n
= real_recvfrom(sk
, buf
, len
, flags
, 0, 0);
1844 n
= real_recvfrom(sk
, buf
, len
, flags
, SA(sabuf
), &mylen
);
1846 D( fprintf(stderr
, " -> converting...\n"); )
1848 return_fake_peer(sk
, SA(sabuf
), mylen
, from
, fromlen
);
1850 D( fprintf(stderr
, "noip(%d): ... RECVFROM", pid
); )
1853 D( dump_addrresult(n
, from
, fromlen ?
*fromlen
: 0); )
1857 ssize_t
sendmsg(int sk
, const struct msghdr
*msg
, int flags
)
1859 struct sockaddr_un sun
;
1860 const struct sockaddr
*sa
= SA(msg
->msg_name
);
1861 struct msghdr mymsg
;
1865 D({ char addrbuf
[ADDRBUFSZ
];
1866 fprintf(stderr
, "noip(%d): SENDMSG sk=%d, "
1867 "msg_flags=%d, msg_name[%d]=%s, ...",
1868 pid
, sk
, msg
->msg_flags
, msg
->msg_namelen
,
1869 present_sockaddr(sa
, msg
->msg_namelen
,
1870 addrbuf
, sizeof(addrbuf
))); })
1873 D( fprintf(stderr
, " -> null address; leaving"); )
1874 else if (!family_known_p(sa
->sa_family
))
1875 D( fprintf(stderr
, " -> unknown af; pass through"); )
1877 D( fprintf(stderr
, " -> checking...\n"); )
1880 fixup_client_socket(sk
, &sa
, &mymsg
.msg_namelen
, &sun
);
1881 mymsg
.msg_name
= SA(sa
);
1884 D( fprintf(stderr
, "noip(%d): SENDMSG ...", pid
); )
1886 n
= real_sendmsg(sk
, msg
, flags
);
1887 D( dump_sysresult(n
); )
1891 ssize_t
recvmsg(int sk
, struct msghdr
*msg
, int flags
)
1894 struct sockaddr
*sa
= SA(msg
->msg_name
);
1895 socklen_t len
= msg
->msg_namelen
;
1899 D( fprintf(stderr
, "noip(%d): RECVMSG sk=%d msg_flags=%d, ...",
1900 pid
, sk
, msg
->msg_flags
); )
1902 if (!msg
->msg_name
) {
1903 D( fprintf(stderr
, " -> null addr; pass through"); )
1904 return (real_recvmsg(sk
, msg
, flags
));
1906 msg
->msg_name
= sabuf
;
1907 msg
->msg_namelen
= sizeof(sabuf
);
1908 n
= real_recvmsg(sk
, msg
, flags
);
1910 D( fprintf(stderr
, " -> converting...\n"); )
1912 return_fake_peer(sk
, SA(sabuf
), msg
->msg_namelen
, sa
, &len
);
1915 D( fprintf(stderr
, "noip(%d): ... RECVMSG", pid
); )
1917 msg
->msg_namelen
= len
;
1919 D( dump_addrresult(n
, sa
, len
); )
1923 int accept(int sk
, struct sockaddr
*sa
, socklen_t
*len
)
1926 socklen_t mylen
= sizeof(sabuf
);
1930 D( fprintf(stderr
, "noip(%d): ACCEPT sk=%d", pid
, sk
); )
1932 nsk
= real_accept(sk
, SA(sabuf
), &mylen
);
1933 if (nsk
< 0) /* failed */;
1934 else if (!sa
) D( fprintf(stderr
, " -> address not wanted"); )
1936 D( fprintf(stderr
, " -> converting...\n"); )
1937 return_fake_peer(sk
, SA(sabuf
), mylen
, sa
, len
);
1938 D( fprintf(stderr
, "noip(%d): ... ACCEPT", pid
); )
1940 D( dump_addrresult(nsk
, sa
, len ?
*len
: 0); )
1944 int getsockname(int sk
, struct sockaddr
*sa
, socklen_t
*len
)
1947 socklen_t mylen
= sizeof(sabuf
);
1951 D( fprintf(stderr
, "noip(%d): GETSOCKNAME sk=%d", pid
, sk
); )
1952 rc
= real_getsockname(sk
, SA(sabuf
), &mylen
);
1954 D( fprintf(stderr
, " -> converting...\n"); )
1955 return_fake_name(SA(sabuf
), mylen
, sa
, len
, 0);
1956 D( fprintf(stderr
, "noip(%d): ... GETSOCKNAME", pid
); )
1958 D( dump_addrresult(rc
, sa
, *len
); )
1962 int getpeername(int sk
, struct sockaddr
*sa
, socklen_t
*len
)
1965 socklen_t mylen
= sizeof(sabuf
);
1969 D( fprintf(stderr
, "noip(%d): GETPEERNAME sk=%d", pid
, sk
); )
1970 rc
= real_getpeername(sk
, SA(sabuf
), &mylen
);
1972 D( fprintf(stderr
, " -> converting...\n"); )
1973 return_fake_peer(sk
, SA(sabuf
), mylen
, sa
, len
);
1974 D( fprintf(stderr
, "noip(%d): ... GETPEERNAME", pid
); )
1976 D( dump_addrresult(rc
, sa
, *len
); )
1980 int getsockopt(int sk
, int lev
, int opt
, void *p
, socklen_t
*len
)
1991 return (real_getsockopt(sk
, lev
, opt
, p
, len
));
1994 int setsockopt(int sk
, int lev
, int opt
, const void *p
, socklen_t len
)
2004 case SO_BINDTODEVICE
:
2005 case SO_ATTACH_FILTER
:
2006 case SO_DETACH_FILTER
:
2009 return (real_setsockopt(sk
, lev
, opt
, p
, len
));
2012 int ioctl(int fd
, unsigned long op
, ...)
2020 arg
= va_arg(ap
, void *);
2024 case SIOCGIFBRDADDR
:
2025 case SIOCGIFDSTADDR
:
2026 case SIOCGIFNETMASK
:
2028 if (fixup_real_ip_socket(fd
, AF_INET
, &sk
)) goto real
;
2030 rc
= real_ioctl(sk
, op
, arg
);
2031 PRESERVING_ERRNO({ close(sk
); });
2035 rc
= real_ioctl(fd
, op
, arg
);
2042 /*----- Initialization ----------------------------------------------------*/
2044 /* Clean up the socket directory, deleting stale sockets. */
2045 static void cleanup_sockdir(void)
2050 struct sockaddr_un sun
;
2054 if ((dir
= opendir(sockdir
)) == 0) return;
2055 sun
.sun_family
= AF_UNIX
;
2056 while ((d
= readdir(dir
)) != 0) {
2057 if (d
->d_name
[0] == '.') continue;
2058 snprintf(sun
.sun_path
, sizeof(sun
.sun_path
),
2059 "%s/%s", sockdir
, d
->d_name
);
2060 if (decode_inet_addr(&addr
.sa
, 0, &sun
, SUN_LEN(&sun
)) ||
2061 stat(sun
.sun_path
, &st
) ||
2062 !S_ISSOCK(st
.st_mode
)) {
2063 D( fprintf(stderr
, "noip(%d): ignoring unknown socketdir entry `%s'\n",
2064 pid
, sun
.sun_path
); )
2067 if (unix_socket_status(&sun
, 0) == STALE
) {
2068 D( fprintf(stderr
, "noip(%d): clearing away stale socket %s\n",
2070 unlink(sun
.sun_path
);
2076 /* Find the addresses attached to local network interfaces, and remember them
2079 static void get_local_ipaddrs(void)
2081 struct ifaddrs
*ifa_head
, *ifa
;
2086 D( fprintf(stderr
, "noip(%d): fetching local addresses...\n", pid
); )
2087 if (getifaddrs(&ifa_head
)) { perror("getifaddrs"); return; }
2088 for (n_local_ipaddrs
= 0, ifa
= ifa_head
;
2089 n_local_ipaddrs
< MAX_LOCAL_IPADDRS
&& ifa
;
2090 ifa
= ifa
->ifa_next
) {
2091 if (!ifa
->ifa_addr
|| !family_known_p(ifa
->ifa_addr
->sa_family
))
2093 ipaddr_from_sockaddr(&a
, ifa
->ifa_addr
);
2094 D({ char buf
[ADDRBUFSZ
];
2095 fprintf(stderr
, "noip(%d): local addr %s = %s", pid
,
2097 inet_ntop(ifa
->ifa_addr
->sa_family
, &a
,
2098 buf
, sizeof(buf
))); })
2099 for (i
= 0; i
< n_local_ipaddrs
; i
++) {
2100 if (ifa
->ifa_addr
->sa_family
== local_ipaddrs
[i
].af
&&
2101 ipaddr_equal_p(local_ipaddrs
[i
].af
, &a
, &local_ipaddrs
[i
].addr
)) {
2102 D( fprintf(stderr
, " (duplicate)\n"); )
2106 D( fprintf(stderr
, "\n"); )
2107 local_ipaddrs
[n_local_ipaddrs
].af
= ifa
->ifa_addr
->sa_family
;
2108 local_ipaddrs
[n_local_ipaddrs
].addr
= a
;
2112 freeifaddrs(ifa_head
);
2115 /* Print the given message to standard error. Avoids stdio. */
2116 static void printerr(const char *p
)
2117 { if (write(STDERR_FILENO
, p
, strlen(p
))) ; }
2119 /* Create the socket directory, being careful about permissions. */
2120 static void create_sockdir(void)
2124 if (lstat(sockdir
, &st
)) {
2125 if (errno
== ENOENT
) {
2126 if (mkdir(sockdir
, 0700)) {
2127 perror("noip: creating socketdir");
2130 if (!lstat(sockdir
, &st
))
2133 perror("noip: checking socketdir");
2137 if (!S_ISDIR(st
.st_mode
)) {
2138 printerr("noip: bad socketdir: not a directory\n");
2141 if (st
.st_uid
!= uid
) {
2142 printerr("noip: bad socketdir: not owner\n");
2145 if (st
.st_mode
& 077) {
2146 printerr("noip: bad socketdir: not private\n");
2151 /* Initialization function. */
2152 static void setup(void) __attribute__((constructor
));
2153 static void setup(void)
2160 if ((p
= getenv("NOIP_DEBUG")) && atoi(p
))
2162 get_local_ipaddrs();
2169 /*----- That's all, folks -------------------------------------------------*/