Commit | Line | Data |
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1d1ccf4f MW |
1 | /* -*-c-*- |
2 | * | |
3 | * Make programs use Unix-domain sockets instead of IP | |
4 | * | |
5 | * (c) 2008 Straylight/Edgeware | |
6 | */ | |
7 | ||
8 | /*----- Licensing notice --------------------------------------------------* | |
9 | * | |
10 | * This file is part of the preload-hacks package. | |
11 | * | |
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. | |
16 | * | |
de6df72d MW |
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 | |
20 | * for more details. | |
1d1ccf4f MW |
21 | * |
22 | * You should have received a copy of the GNU General Public License along | |
de6df72d MW |
23 | * with preload-hacks; if not, write to the Free Software Foundation, Inc., |
24 | * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
1d1ccf4f MW |
25 | */ |
26 | ||
e4976bb0 | 27 | #define _GNU_SOURCE |
28 | #undef sun | |
29 | #undef SUN | |
30 | #define DEBUG | |
31 | ||
1d1ccf4f MW |
32 | /*----- Header files ------------------------------------------------------*/ |
33 | ||
9314b85a | 34 | #include <assert.h> |
e4976bb0 | 35 | #include <ctype.h> |
36 | #include <errno.h> | |
658c1774 | 37 | #include <stdarg.h> |
9314b85a | 38 | #include <stddef.h> |
e4976bb0 | 39 | #include <stdio.h> |
40 | #include <stdlib.h> | |
41 | ||
42 | #include <unistd.h> | |
43 | #include <dirent.h> | |
44 | #include <dlfcn.h> | |
45 | #include <fcntl.h> | |
46 | #include <pwd.h> | |
47 | ||
48 | #include <sys/ioctl.h> | |
49 | #include <sys/socket.h> | |
50 | #include <sys/stat.h> | |
51 | #include <sys/un.h> | |
52 | ||
53 | #include <netinet/in.h> | |
54 | #include <arpa/inet.h> | |
55 | #include <netinet/tcp.h> | |
56 | #include <netinet/udp.h> | |
9f1396d9 | 57 | #include <ifaddrs.h> |
9314b85a | 58 | #include <netdb.h> |
e4976bb0 | 59 | |
1d1ccf4f MW |
60 | /*----- Data structures ---------------------------------------------------*/ |
61 | ||
74eb4869 MW |
62 | /* Unix socket status values. */ |
63 | #define UNUSED 0u /* No sign of anyone using it */ | |
64 | #define STALE 1u /* Socket exists, but is abandoned */ | |
65 | #define USED 16u /* Socket is in active use */ | |
97162e5b | 66 | #define LISTEN 2u /* Socket has an active listener */ |
74eb4869 | 67 | |
1d1ccf4f MW |
68 | enum { DENY, ALLOW }; /* ACL verdicts */ |
69 | ||
2a06ea0b | 70 | static int address_families[] = { AF_INET, AF_INET6, -1 }; |
9314b85a MW |
71 | |
72 | #define ADDRBUFSZ 64 | |
73 | ||
74 | /* Address representations. */ | |
75 | typedef union ipaddr { | |
76 | struct in_addr v4; | |
2a06ea0b | 77 | struct in6_addr v6; |
9314b85a MW |
78 | } ipaddr; |
79 | ||
80 | /* Convenient socket address hacking. */ | |
81 | typedef union address { | |
82 | struct sockaddr sa; | |
83 | struct sockaddr_in sin; | |
2a06ea0b | 84 | struct sockaddr_in6 sin6; |
9314b85a MW |
85 | } address; |
86 | ||
1d1ccf4f | 87 | /* Access control list nodes */ |
e4976bb0 | 88 | typedef struct aclnode { |
89 | struct aclnode *next; | |
90 | int act; | |
9314b85a MW |
91 | int af; |
92 | ipaddr minaddr, maxaddr; | |
e4976bb0 | 93 | unsigned short minport, maxport; |
94 | } aclnode; | |
95 | ||
7be80f86 MW |
96 | /* Implicit bind records */ |
97 | typedef struct impbind { | |
98 | struct impbind *next; | |
99 | int af, how; | |
100 | ipaddr minaddr, maxaddr, bindaddr; | |
101 | } impbind; | |
102 | enum { EXPLICIT, SAME }; | |
103 | ||
006dd63f MW |
104 | /* A type for an address range */ |
105 | typedef struct addrrange { | |
106 | int type; | |
107 | union { | |
108 | struct { int af; ipaddr min, max; } range; | |
109 | } u; | |
110 | } addrrange; | |
111 | enum { EMPTY, ANY, LOCAL, RANGE }; | |
112 | ||
1d1ccf4f | 113 | /* Local address records */ |
9314b85a MW |
114 | typedef struct full_ipaddr { |
115 | int af; | |
116 | ipaddr addr; | |
117 | } full_ipaddr; | |
2a06ea0b | 118 | #define MAX_LOCAL_IPADDRS 64 |
9314b85a | 119 | static full_ipaddr local_ipaddrs[MAX_LOCAL_IPADDRS]; |
e4976bb0 | 120 | static int n_local_ipaddrs; |
121 | ||
1d1ccf4f | 122 | /* General configuration */ |
e4976bb0 | 123 | static uid_t uid; |
124 | static char *sockdir = 0; | |
125 | static int debug = 0; | |
f6049fdd | 126 | static unsigned minautoport = 16384, maxautoport = 65536; |
e4976bb0 | 127 | |
1d1ccf4f | 128 | /* Access control lists */ |
e4976bb0 | 129 | static aclnode *bind_real, **bind_tail = &bind_real; |
130 | static aclnode *connect_real, **connect_tail = &connect_real; | |
7be80f86 | 131 | static impbind *impbinds, **impbind_tail = &impbinds; |
e4976bb0 | 132 | |
1d1ccf4f | 133 | /*----- Import the real versions of functions -----------------------------*/ |
e4976bb0 | 134 | |
1d1ccf4f | 135 | /* The list of functions to immport. */ |
e4976bb0 | 136 | #define IMPORTS(_) \ |
137 | _(socket, int, (int, int, int)) \ | |
138 | _(socketpair, int, (int, int, int, int *)) \ | |
139 | _(connect, int, (int, const struct sockaddr *, socklen_t)) \ | |
140 | _(bind, int, (int, const struct sockaddr *, socklen_t)) \ | |
141 | _(accept, int, (int, struct sockaddr *, socklen_t *)) \ | |
142 | _(getsockname, int, (int, struct sockaddr *, socklen_t *)) \ | |
143 | _(getpeername, int, (int, struct sockaddr *, socklen_t *)) \ | |
144 | _(getsockopt, int, (int, int, int, void *, socklen_t *)) \ | |
145 | _(setsockopt, int, (int, int, int, const void *, socklen_t)) \ | |
146 | _(sendto, ssize_t, (int, const void *buf, size_t, int, \ | |
147 | const struct sockaddr *to, socklen_t tolen)) \ | |
148 | _(recvfrom, ssize_t, (int, void *buf, size_t, int, \ | |
7d769c69 | 149 | struct sockaddr *from, socklen_t *fromlen)) \ |
e4976bb0 | 150 | _(sendmsg, ssize_t, (int, const struct msghdr *, int)) \ |
658c1774 MW |
151 | _(recvmsg, ssize_t, (int, struct msghdr *, int)) \ |
152 | _(ioctl, int, (int, unsigned long, ...)) | |
e4976bb0 | 153 | |
1d1ccf4f | 154 | /* Function pointers to set up. */ |
e4976bb0 | 155 | #define DECL(imp, ret, args) static ret (*real_##imp) args; |
156 | IMPORTS(DECL) | |
157 | #undef DECL | |
158 | ||
1d1ccf4f | 159 | /* Import the system calls. */ |
e4976bb0 | 160 | static void import(void) |
161 | { | |
162 | #define IMPORT(imp, ret, args) \ | |
163 | real_##imp = (ret (*)args)dlsym(RTLD_NEXT, #imp); | |
164 | IMPORTS(IMPORT) | |
165 | #undef IMPORT | |
166 | } | |
167 | ||
1d1ccf4f | 168 | /*----- Utilities ---------------------------------------------------------*/ |
e4976bb0 | 169 | |
1d1ccf4f | 170 | /* Socket address casts */ |
e4976bb0 | 171 | #define SA(sa) ((struct sockaddr *)(sa)) |
172 | #define SIN(sa) ((struct sockaddr_in *)(sa)) | |
2a06ea0b | 173 | #define SIN6(sa) ((struct sockaddr_in6 *)(sa)) |
e4976bb0 | 174 | #define SUN(sa) ((struct sockaddr_un *)(sa)) |
175 | ||
1d1ccf4f | 176 | /* Raw bytes */ |
e4976bb0 | 177 | #define UC(ch) ((unsigned char)(ch)) |
178 | ||
1d1ccf4f | 179 | /* Memory allocation */ |
e4976bb0 | 180 | #define NEW(x) ((x) = xmalloc(sizeof(*x))) |
181 | #define NEWV(x, n) ((x) = xmalloc(sizeof(*x) * (n))) | |
182 | ||
1d1ccf4f | 183 | /* Debugging */ |
e4976bb0 | 184 | #ifdef DEBUG |
185 | # define D(body) { if (debug) { body } } | |
e397f0bd | 186 | # define Dpid pid_t pid = debug ? getpid() : -1 |
e4976bb0 | 187 | #else |
188 | # define D(body) ; | |
e397f0bd | 189 | # define Dpid |
e4976bb0 | 190 | #endif |
191 | ||
1d1ccf4f | 192 | /* Preservation of error status */ |
e4976bb0 | 193 | #define PRESERVING_ERRNO(body) do { \ |
194 | int _err = errno; { body } errno = _err; \ | |
195 | } while (0) | |
196 | ||
1d1ccf4f | 197 | /* Allocate N bytes of memory; abort on failure. */ |
e4976bb0 | 198 | static void *xmalloc(size_t n) |
199 | { | |
200 | void *p; | |
201 | if (!n) return (0); | |
3ef1fec9 | 202 | if ((p = malloc(n)) == 0) { perror("malloc"); exit(127); } |
e4976bb0 | 203 | return (p); |
204 | } | |
205 | ||
1d1ccf4f | 206 | /* Allocate a copy of the null-terminated string P; abort on failure. */ |
e4976bb0 | 207 | static char *xstrdup(const char *p) |
208 | { | |
209 | size_t n = strlen(p) + 1; | |
210 | char *q = xmalloc(n); | |
211 | memcpy(q, p, n); | |
212 | return (q); | |
213 | } | |
9314b85a MW |
214 | |
215 | /*----- Address-type hacking ----------------------------------------------*/ | |
216 | ||
217 | /* If M is a simple mask, i.e., consists of a sequence of zero bits followed | |
218 | * by a sequence of one bits, then return the length of the latter sequence | |
219 | * (which may be zero); otherwise return -1. | |
220 | */ | |
221 | static int simple_mask_length(unsigned long m) | |
222 | { | |
223 | int n = 0; | |
224 | ||
225 | while (m & 1) { n++; m >>= 1; } | |
226 | return (m ? -1 : n); | |
227 | } | |
228 | ||
229 | /* Answer whether AF is an interesting address family. */ | |
230 | static int family_known_p(int af) | |
231 | { | |
232 | switch (af) { | |
233 | case AF_INET: | |
2a06ea0b | 234 | case AF_INET6: |
9314b85a MW |
235 | return (1); |
236 | default: | |
237 | return (0); | |
238 | } | |
239 | } | |
240 | ||
241 | /* Return the socket address length for address family AF. */ | |
242 | static socklen_t family_socklen(int af) | |
243 | { | |
244 | switch (af) { | |
245 | case AF_INET: return (sizeof(struct sockaddr_in)); | |
2a06ea0b | 246 | case AF_INET6: return (sizeof(struct sockaddr_in6)); |
9314b85a MW |
247 | default: abort(); |
248 | } | |
249 | } | |
250 | ||
251 | /* Return the width of addresses of kind AF. */ | |
252 | static int address_width(int af) | |
253 | { | |
254 | switch (af) { | |
255 | case AF_INET: return 32; | |
2a06ea0b | 256 | case AF_INET6: return 128; |
9314b85a MW |
257 | default: abort(); |
258 | } | |
259 | } | |
260 | ||
261 | /* If addresses A and B share a common prefix then return its length; | |
262 | * otherwise return -1. | |
263 | */ | |
264 | static int common_prefix_length(int af, const ipaddr *a, const ipaddr *b) | |
265 | { | |
266 | switch (af) { | |
267 | case AF_INET: { | |
268 | unsigned long aa = ntohl(a->v4.s_addr), bb = ntohl(b->v4.s_addr); | |
269 | unsigned long m = aa^bb; | |
270 | if ((aa&m) == 0 && (bb&m) == m) return (32 - simple_mask_length(m)); | |
271 | else return (-1); | |
272 | } break; | |
2a06ea0b MW |
273 | case AF_INET6: { |
274 | const uint8_t *aa = a->v6.s6_addr, *bb = b->v6.s6_addr; | |
275 | unsigned m; | |
276 | unsigned n; | |
277 | int i; | |
278 | ||
279 | for (i = 0; i < 16 && aa[i] == bb[i]; i++); | |
280 | n = 8*i; | |
281 | if (i < 16) { | |
282 | m = aa[i]^bb[i]; | |
283 | if ((aa[i]&m) != 0 || (bb[i]&m) != m) return (-1); | |
284 | n += 8 - simple_mask_length(m); | |
285 | for (i++; i < 16; i++) | |
286 | if (aa[i] || bb[i] != 0xff) return (-1); | |
287 | } | |
288 | return (n); | |
289 | } break; | |
9314b85a MW |
290 | default: |
291 | abort(); | |
292 | } | |
293 | } | |
294 | ||
295 | /* Extract the port number (in host byte-order) from SA. */ | |
296 | static int port_from_sockaddr(const struct sockaddr *sa) | |
297 | { | |
298 | switch (sa->sa_family) { | |
299 | case AF_INET: return (ntohs(SIN(sa)->sin_port)); | |
2a06ea0b | 300 | case AF_INET6: return (ntohs(SIN6(sa)->sin6_port)); |
9314b85a MW |
301 | default: abort(); |
302 | } | |
303 | } | |
304 | ||
305 | /* Store the port number PORT (in host byte-order) in SA. */ | |
306 | static void port_to_sockaddr(struct sockaddr *sa, int port) | |
307 | { | |
308 | switch (sa->sa_family) { | |
309 | case AF_INET: SIN(sa)->sin_port = htons(port); break; | |
2a06ea0b | 310 | case AF_INET6: SIN6(sa)->sin6_port = htons(port); break; |
9314b85a MW |
311 | default: abort(); |
312 | } | |
313 | } | |
10cee633 | 314 | |
9314b85a MW |
315 | /* Extract the address part from SA and store it in A. */ |
316 | static void ipaddr_from_sockaddr(ipaddr *a, const struct sockaddr *sa) | |
317 | { | |
318 | switch (sa->sa_family) { | |
319 | case AF_INET: a->v4 = SIN(sa)->sin_addr; break; | |
2a06ea0b | 320 | case AF_INET6: a->v6 = SIN6(sa)->sin6_addr; break; |
9314b85a MW |
321 | default: abort(); |
322 | } | |
323 | } | |
324 | ||
7be80f86 MW |
325 | /* Store the address A in SA. */ |
326 | static void ipaddr_to_sockaddr(struct sockaddr *sa, const ipaddr *a) | |
327 | { | |
328 | switch (sa->sa_family) { | |
329 | case AF_INET: | |
330 | SIN(sa)->sin_addr = a->v4; | |
331 | break; | |
332 | case AF_INET6: | |
333 | SIN6(sa)->sin6_addr = a->v6; | |
334 | SIN6(sa)->sin6_scope_id = 0; | |
335 | SIN6(sa)->sin6_flowinfo = 0; | |
336 | break; | |
337 | default: | |
338 | abort(); | |
339 | } | |
340 | } | |
341 | ||
9314b85a MW |
342 | /* Copy a whole socket address about. */ |
343 | static void copy_sockaddr(struct sockaddr *sa_dst, | |
344 | const struct sockaddr *sa_src) | |
345 | { memcpy(sa_dst, sa_src, family_socklen(sa_src->sa_family)); } | |
346 | ||
a62e4ece MW |
347 | /* Convert an AF_INET socket address into the equivalent IPv4-mapped AF_INET6 |
348 | * address. | |
349 | */ | |
350 | static void map_ipv4_sockaddr(struct sockaddr_in6 *a6, | |
351 | const struct sockaddr_in *a4) | |
352 | { | |
353 | size_t i; | |
354 | in_addr_t a = ntohl(a4->sin_addr.s_addr); | |
355 | ||
356 | a6->sin6_family = AF_INET6; | |
357 | a6->sin6_port = a4->sin_port; | |
358 | a6->sin6_scope_id = 0; | |
359 | a6->sin6_flowinfo = 0; | |
360 | for (i = 0; i < 10; i++) a6->sin6_addr.s6_addr[i] = 0; | |
361 | for (i = 10; i < 12; i++) a6->sin6_addr.s6_addr[i] = 0xff; | |
362 | for (i = 0; i < 4; i++) a6->sin6_addr.s6_addr[15 - i] = (a >> 8*i)&0xff; | |
363 | } | |
364 | ||
365 | /* Convert an AF_INET6 socket address containing an IPv4-mapped IPv6 address | |
366 | * into the equivalent AF_INET4 address. Return zero on success, or -1 if | |
367 | * the address has the wrong form. | |
368 | */ | |
369 | static int unmap_ipv4_sockaddr(struct sockaddr_in *a4, | |
370 | const struct sockaddr_in6 *a6) | |
371 | { | |
372 | size_t i; | |
373 | in_addr_t a; | |
374 | ||
375 | for (i = 0; i < 10; i++) if (a6->sin6_addr.s6_addr[i] != 0) return (-1); | |
376 | for (i = 10; i < 12; i++) if (a6->sin6_addr.s6_addr[i] != 0xff) return (-1); | |
377 | for (i = 0, a = 0; i < 4; i++) a |= a6->sin6_addr.s6_addr[15 - i] << 8*i; | |
378 | a4->sin_family = AF_INET; | |
379 | a4->sin_port = a6->sin6_port; | |
380 | a4->sin_addr.s_addr = htonl(a); | |
381 | return (0); | |
382 | } | |
383 | ||
9314b85a MW |
384 | /* Answer whether two addresses are equal. */ |
385 | static int ipaddr_equal_p(int af, const ipaddr *a, const ipaddr *b) | |
386 | { | |
387 | switch (af) { | |
388 | case AF_INET: return (a->v4.s_addr == b->v4.s_addr); | |
2a06ea0b | 389 | case AF_INET6: return (memcmp(a->v6.s6_addr, b->v6.s6_addr, 16) == 0); |
9314b85a MW |
390 | default: abort(); |
391 | } | |
392 | } | |
393 | ||
394 | /* Answer whether the address part of SA is between A and B (inclusive). We | |
395 | * assume that SA has the correct address family. | |
396 | */ | |
397 | static int sockaddr_in_range_p(const struct sockaddr *sa, | |
398 | const ipaddr *a, const ipaddr *b) | |
399 | { | |
400 | switch (sa->sa_family) { | |
401 | case AF_INET: { | |
402 | unsigned long addr = ntohl(SIN(sa)->sin_addr.s_addr); | |
403 | return (ntohl(a->v4.s_addr) <= addr && | |
404 | addr <= ntohl(b->v4.s_addr)); | |
405 | } break; | |
2a06ea0b MW |
406 | case AF_INET6: { |
407 | const uint8_t *ss = SIN6(sa)->sin6_addr.s6_addr; | |
408 | const uint8_t *aa = a->v6.s6_addr, *bb = b->v6.s6_addr; | |
409 | int h = 1, l = 1; | |
410 | int i; | |
411 | ||
412 | for (i = 0; h && l && i < 16; i++, ss++, aa++, bb++) { | |
413 | if (*ss < *aa || *bb < *ss) return (0); | |
414 | if (*aa < *ss) l = 0; | |
415 | if (*ss < *bb) h = 0; | |
416 | } | |
417 | return (1); | |
418 | } break; | |
9314b85a MW |
419 | default: |
420 | abort(); | |
421 | } | |
422 | } | |
423 | ||
424 | /* Fill in SA with the appropriate wildcard address. */ | |
425 | static void wildcard_address(int af, struct sockaddr *sa) | |
426 | { | |
427 | switch (af) { | |
428 | case AF_INET: { | |
429 | struct sockaddr_in *sin = SIN(sa); | |
430 | memset(sin, 0, sizeof(*sin)); | |
431 | sin->sin_family = AF_INET; | |
432 | sin->sin_port = 0; | |
433 | sin->sin_addr.s_addr = INADDR_ANY; | |
434 | } break; | |
2a06ea0b MW |
435 | case AF_INET6: { |
436 | struct sockaddr_in6 *sin6 = SIN6(sa); | |
dc2b0a44 | 437 | memset(sin6, 0, sizeof(*sin6)); |
2a06ea0b MW |
438 | sin6->sin6_family = AF_INET6; |
439 | sin6->sin6_port = 0; | |
440 | sin6->sin6_addr = in6addr_any; | |
441 | sin6->sin6_scope_id = 0; | |
442 | sin6->sin6_flowinfo = 0; | |
443 | } break; | |
9314b85a MW |
444 | default: |
445 | abort(); | |
446 | } | |
447 | } | |
448 | ||
449 | /* Mask the address A, forcing all but the top PLEN bits to zero or one | |
450 | * according to HIGHP. | |
451 | */ | |
452 | static void mask_address(int af, ipaddr *a, int plen, int highp) | |
453 | { | |
454 | switch (af) { | |
455 | case AF_INET: { | |
456 | unsigned long addr = ntohl(a->v4.s_addr); | |
457 | unsigned long mask = plen ? ~0ul << (32 - plen) : 0; | |
458 | addr &= mask; | |
459 | if (highp) addr |= ~mask; | |
460 | a->v4.s_addr = htonl(addr & 0xffffffff); | |
461 | } break; | |
2a06ea0b MW |
462 | case AF_INET6: { |
463 | int i = plen/8; | |
464 | unsigned m = (0xff << (8 - plen%8)) & 0xff; | |
465 | unsigned s = highp ? 0xff : 0; | |
466 | if (m) { | |
467 | a->v6.s6_addr[i] = (a->v6.s6_addr[i] & m) | (s & ~m); | |
468 | i++; | |
469 | } | |
470 | for (; i < 16; i++) a->v6.s6_addr[i] = s; | |
471 | } break; | |
9314b85a MW |
472 | default: |
473 | abort(); | |
474 | } | |
475 | } | |
476 | ||
477 | /* Write a presentation form of SA to BUF, a buffer of length SZ. LEN is the | |
478 | * address length; if it's zero, look it up based on the address family. | |
479 | * Return a pointer to the string (which might, in an emergency, be a static | |
480 | * string rather than your buffer). | |
481 | */ | |
482 | static char *present_sockaddr(const struct sockaddr *sa, socklen_t len, | |
483 | char *buf, size_t sz) | |
484 | { | |
485 | #define WANT(n_) do { if (sz < (n_)) goto nospace; } while (0) | |
486 | #define PUTC(c_) do { *buf++ = (c_); sz--; } while (0) | |
487 | ||
ad0f7002 | 488 | if (!sa) return "<null-address>"; |
9314b85a MW |
489 | if (!sz) return "<no-space-in-buffer>"; |
490 | if (!len) len = family_socklen(sa->sa_family); | |
491 | ||
492 | switch (sa->sa_family) { | |
493 | case AF_UNIX: { | |
494 | struct sockaddr_un *sun = SUN(sa); | |
495 | char *p = sun->sun_path; | |
496 | size_t n = len - offsetof(struct sockaddr_un, sun_path); | |
497 | ||
498 | assert(n); | |
499 | if (*p == 0) { | |
500 | WANT(1); PUTC('@'); | |
501 | p++; n--; | |
502 | while (n) { | |
503 | switch (*p) { | |
504 | case 0: WANT(2); PUTC('\\'); PUTC('0'); break; | |
505 | case '\a': WANT(2); PUTC('\\'); PUTC('a'); break; | |
506 | case '\n': WANT(2); PUTC('\\'); PUTC('n'); break; | |
507 | case '\r': WANT(2); PUTC('\\'); PUTC('r'); break; | |
508 | case '\t': WANT(2); PUTC('\\'); PUTC('t'); break; | |
509 | case '\v': WANT(2); PUTC('\\'); PUTC('v'); break; | |
510 | case '\\': WANT(2); PUTC('\\'); PUTC('\\'); break; | |
511 | default: | |
512 | if (*p > ' ' && *p <= '~') | |
513 | { WANT(1); PUTC(*p); } | |
514 | else { | |
515 | WANT(4); PUTC('\\'); PUTC('x'); | |
516 | PUTC((*p >> 4)&0xf); PUTC((*p >> 0)&0xf); | |
517 | } | |
518 | break; | |
519 | } | |
520 | p++; n--; | |
521 | } | |
522 | } else { | |
523 | if (*p != '/') { WANT(2); PUTC('.'); PUTC('/'); } | |
524 | while (n && *p) { WANT(1); PUTC(*p); p++; n--; } | |
525 | } | |
526 | WANT(1); PUTC(0); | |
527 | } break; | |
2a06ea0b | 528 | case AF_INET: case AF_INET6: { |
9314b85a MW |
529 | char addrbuf[NI_MAXHOST], portbuf[NI_MAXSERV]; |
530 | int err = getnameinfo(sa, len, | |
531 | addrbuf, sizeof(addrbuf), | |
532 | portbuf, sizeof(portbuf), | |
533 | NI_NUMERICHOST | NI_NUMERICSERV); | |
534 | assert(!err); | |
535 | snprintf(buf, sz, strchr(addrbuf, ':') ? "[%s]:%s" : "%s:%s", | |
536 | addrbuf, portbuf); | |
537 | } break; | |
538 | default: | |
539 | snprintf(buf, sz, "<unknown-address-family %d>", sa->sa_family); | |
540 | break; | |
541 | } | |
542 | return (buf); | |
543 | ||
544 | nospace: | |
545 | buf[sz - 1] = 0; | |
546 | return (buf); | |
547 | } | |
548 | ||
549 | /* Guess the family of a textual socket address. */ | |
550 | static int guess_address_family(const char *p) | |
2a06ea0b | 551 | { return (strchr(p, ':') ? AF_INET6 : AF_INET); } |
9314b85a MW |
552 | |
553 | /* Parse a socket address P and write the result to SA. */ | |
554 | static int parse_sockaddr(struct sockaddr *sa, const char *p) | |
555 | { | |
556 | char buf[ADDRBUFSZ]; | |
557 | char *q; | |
558 | struct addrinfo *ai, ai_hint = { 0 }; | |
559 | ||
560 | if (strlen(p) >= sizeof(buf) - 1) return (-1); | |
561 | strcpy(buf, p); p = buf; | |
562 | if (*p != '[') { | |
563 | if ((q = strchr(p, ':')) == 0) return (-1); | |
564 | *q++ = 0; | |
565 | } else { | |
566 | p++; | |
567 | if ((q = strchr(p, ']')) == 0) return (-1); | |
568 | *q++ = 0; | |
569 | if (*q != ':') return (-1); | |
570 | q++; | |
571 | } | |
572 | ||
573 | ai_hint.ai_family = AF_UNSPEC; | |
574 | ai_hint.ai_socktype = SOCK_DGRAM; | |
575 | ai_hint.ai_flags = AI_NUMERICHOST | AI_NUMERICSERV; | |
576 | if (getaddrinfo(p, q, &ai_hint, &ai)) return (-1); | |
577 | memcpy(sa, ai->ai_addr, ai->ai_addrlen); | |
578 | freeaddrinfo(ai); | |
579 | return (0); | |
580 | } | |
581 | ||
1d1ccf4f | 582 | /*----- Access control lists ----------------------------------------------*/ |
e4976bb0 | 583 | |
584 | #ifdef DEBUG | |
585 | ||
006dd63f | 586 | static void dump_addrrange(int af, const ipaddr *min, const ipaddr *max) |
e4976bb0 | 587 | { |
9314b85a MW |
588 | char buf[ADDRBUFSZ]; |
589 | const char *p; | |
590 | int plen; | |
e4976bb0 | 591 | |
006dd63f MW |
592 | plen = common_prefix_length(af, min, max); |
593 | p = inet_ntop(af, min, buf, sizeof(buf)); | |
9314b85a MW |
594 | fprintf(stderr, strchr(p, ':') ? "[%s]" : "%s", p); |
595 | if (plen < 0) { | |
006dd63f | 596 | p = inet_ntop(af, &max, buf, sizeof(buf)); |
9314b85a | 597 | fprintf(stderr, strchr(p, ':') ? "-[%s]" : "-%s", p); |
006dd63f | 598 | } else if (plen < address_width(af)) |
9314b85a | 599 | fprintf(stderr, "/%d", plen); |
006dd63f MW |
600 | } |
601 | ||
602 | /* Write to standard error a description of the ACL node A. */ | |
603 | static void dump_aclnode(const aclnode *a) | |
604 | { | |
605 | fprintf(stderr, "noip(%d): %c ", getpid(), a->act ? '+' : '-'); | |
606 | dump_addrrange(a->af, &a->minaddr, &a->maxaddr); | |
e4976bb0 | 607 | if (a->minport != 0 || a->maxport != 0xffff) { |
608 | fprintf(stderr, ":%u", (unsigned)a->minport); | |
609 | if (a->minport != a->maxport) | |
610 | fprintf(stderr, "-%u", (unsigned)a->maxport); | |
611 | } | |
612 | fputc('\n', stderr); | |
613 | } | |
614 | ||
bb182ccf | 615 | static void dump_acl(const aclnode *a) |
1d1ccf4f MW |
616 | { |
617 | int act = ALLOW; | |
618 | ||
619 | for (; a; a = a->next) { | |
620 | dump_aclnode(a); | |
621 | act = a->act; | |
622 | } | |
e397f0bd | 623 | fprintf(stderr, "noip(%d): [default policy: %s]\n", getpid(), |
1d1ccf4f MW |
624 | act == ALLOW ? "DENY" : "ALLOW"); |
625 | } | |
626 | ||
e4976bb0 | 627 | #endif |
628 | ||
9314b85a | 629 | /* Returns nonzero if the ACL A allows the socket address SA. */ |
bb182ccf | 630 | static int acl_allows_p(const aclnode *a, const struct sockaddr *sa) |
e4976bb0 | 631 | { |
9314b85a | 632 | unsigned short port = port_from_sockaddr(sa); |
e4976bb0 | 633 | int act = ALLOW; |
e397f0bd | 634 | Dpid; |
e4976bb0 | 635 | |
9314b85a | 636 | D({ char buf[ADDRBUFSZ]; |
e397f0bd | 637 | fprintf(stderr, "noip(%d): check %s\n", pid, |
9314b85a | 638 | present_sockaddr(sa, 0, buf, sizeof(buf))); }) |
e4976bb0 | 639 | for (; a; a = a->next) { |
640 | D( dump_aclnode(a); ) | |
deedf22d MW |
641 | if (a->af == sa->sa_family && |
642 | sockaddr_in_range_p(sa, &a->minaddr, &a->maxaddr) && | |
e4976bb0 | 643 | a->minport <= port && port <= a->maxport) { |
e397f0bd MW |
644 | D( fprintf(stderr, "noip(%d): aha! %s\n", pid, |
645 | a->act ? "ALLOW" : "DENY"); ) | |
e4976bb0 | 646 | return (a->act); |
647 | } | |
648 | act = a->act; | |
649 | } | |
e397f0bd MW |
650 | D( fprintf(stderr, "noip(%d): nothing found: %s\n", pid, |
651 | act ? "DENY" : "ALLOW"); ) | |
e4976bb0 | 652 | return (!act); |
653 | } | |
654 | ||
1d1ccf4f | 655 | /*----- Socket address conversion -----------------------------------------*/ |
e4976bb0 | 656 | |
1d1ccf4f | 657 | /* Return a uniformly distributed integer between MIN and MAX inclusive. */ |
f6049fdd | 658 | static unsigned randrange(unsigned min, unsigned max) |
659 | { | |
660 | unsigned mask, i; | |
661 | ||
662 | /* It's so nice not to have to care about the quality of the generator | |
9314b85a MW |
663 | * much! |
664 | */ | |
f6049fdd | 665 | max -= min; |
666 | for (mask = 1; mask < max; mask = (mask << 1) | 1) | |
667 | ; | |
668 | do i = rand() & mask; while (i > max); | |
669 | return (i + min); | |
670 | } | |
671 | ||
1d1ccf4f MW |
672 | /* Return the status of Unix-domain socket address SUN. Returns: UNUSED if |
673 | * the socket doesn't exist; USED if the path refers to an active socket, or | |
674 | * isn't really a socket at all, or we can't tell without a careful search | |
675 | * and QUICKP is set; or STALE if the file refers to a socket which isn't | |
676 | * being used any more. | |
677 | */ | |
678 | static int unix_socket_status(struct sockaddr_un *sun, int quickp) | |
679 | { | |
680 | struct stat st; | |
681 | FILE *fp = 0; | |
682 | size_t len, n; | |
683 | int rc; | |
97162e5b | 684 | unsigned long f; |
1d1ccf4f MW |
685 | char buf[256]; |
686 | ||
4b1a6174 MW |
687 | /* If we can't find the socket node, then it's definitely not in use. If |
688 | * we get some other error, then this socket is weird. | |
689 | */ | |
1d1ccf4f MW |
690 | if (stat(sun->sun_path, &st)) |
691 | return (errno == ENOENT ? UNUSED : USED); | |
4b1a6174 MW |
692 | |
693 | /* If it's not a socket, then something weird is going on. If we're just | |
694 | * probing quickly to find a spare port, then existence is sufficient to | |
695 | * discourage us now. | |
696 | */ | |
1d1ccf4f MW |
697 | if (!S_ISSOCK(st.st_mode) || quickp) |
698 | return (USED); | |
4b1a6174 MW |
699 | |
700 | /* The socket's definitely there, but is anyone actually still holding it | |
701 | * open? The only way I know to discover this is to trundle through | |
702 | * `/proc/net/unix'. If there's no entry, then the socket must be stale. | |
703 | */ | |
1d1ccf4f MW |
704 | rc = USED; |
705 | if ((fp = fopen("/proc/net/unix", "r")) == 0) | |
706 | goto done; | |
72d85cdb | 707 | if (!fgets(buf, sizeof(buf), fp)) goto done; /* skip header */ |
1d1ccf4f | 708 | len = strlen(sun->sun_path); |
61fbb4a5 | 709 | rc = 0; |
1d1ccf4f MW |
710 | while (fgets(buf, sizeof(buf), fp)) { |
711 | n = strlen(buf); | |
712 | if (n >= len + 2 && buf[n - len - 2] == ' ' && buf[n - 1] == '\n' && | |
61fbb4a5 MW |
713 | memcmp(buf + n - len - 1, sun->sun_path, len) == 0) { |
714 | rc |= USED; | |
97162e5b MW |
715 | if (sscanf(buf, "%*s %*x %*x %lx", &f) < 0 || (f&0x00010000)) |
716 | rc |= LISTEN; | |
61fbb4a5 | 717 | } |
1d1ccf4f MW |
718 | } |
719 | if (ferror(fp)) | |
720 | goto done; | |
61fbb4a5 | 721 | if (!rc) rc = STALE; |
1d1ccf4f MW |
722 | done: |
723 | if (fp) fclose(fp); | |
4b1a6174 MW |
724 | |
725 | /* All done. */ | |
1d1ccf4f MW |
726 | return (rc); |
727 | } | |
728 | ||
81e3737d MW |
729 | /* Encode SA as a Unix-domain address SUN, and return whether it's currently |
730 | * in use. | |
731 | */ | |
732 | static int encode_single_inet_addr(const struct sockaddr *sa, | |
733 | struct sockaddr_un *sun, | |
734 | int quickp) | |
735 | { | |
736 | char buf[ADDRBUFSZ]; | |
737 | int rc; | |
738 | ||
739 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir, | |
740 | present_sockaddr(sa, 0, buf, sizeof(buf))); | |
c0ae47b3 MW |
741 | rc = unix_socket_status(sun, quickp); |
742 | if (rc == STALE) unlink(sun->sun_path); | |
743 | return (rc); | |
81e3737d MW |
744 | } |
745 | ||
f6e0ea86 MW |
746 | /* Convert the IP address SA to a Unix-domain address SUN. Fail if the |
747 | * address seems already taken. If DESPARATEP then try cleaning up stale old | |
748 | * sockets. | |
749 | */ | |
750 | static int encode_unused_inet_addr(struct sockaddr *sa, | |
751 | struct sockaddr_un *sun, | |
752 | int desperatep) | |
753 | { | |
a62e4ece | 754 | address waddr, maddr; |
f6e0ea86 | 755 | struct sockaddr_un wsun; |
d0e289af | 756 | int port = port_from_sockaddr(sa); |
f6e0ea86 | 757 | |
4b1a6174 MW |
758 | /* First, look for an exact match. Only look quickly unless we're |
759 | * desperate. If the socket is in use, we fail here. (This could get | |
760 | * racy. Let's not worry about that for now.) | |
761 | */ | |
74eb4869 | 762 | if (encode_single_inet_addr(sa, sun, !desperatep)&USED) |
81e3737d | 763 | return (-1); |
f6e0ea86 | 764 | |
4b1a6174 MW |
765 | /* Next, check the corresponding wildcard address, so as to avoid |
766 | * inadvertant collisions with listeners. Do this in the same way. | |
767 | */ | |
f6e0ea86 | 768 | wildcard_address(sa->sa_family, &waddr.sa); |
d0e289af | 769 | port_to_sockaddr(&waddr.sa, port); |
74eb4869 | 770 | if (encode_single_inet_addr(&waddr.sa, &wsun, !desperatep)&USED) |
81e3737d | 771 | return (-1); |
f6e0ea86 | 772 | |
a62e4ece MW |
773 | /* We're not done yet. If this is an IPv4 address, then /also/ check (a) |
774 | * the v6-mapped version, (b) the v6-mapped v4 wildcard, /and/ (c) the v6 | |
775 | * wildcard. Ugh! | |
776 | */ | |
777 | if (sa->sa_family == AF_INET) { | |
778 | map_ipv4_sockaddr(&maddr.sin6, SIN(&sa)); | |
74eb4869 | 779 | if (encode_single_inet_addr(&maddr.sa, &wsun, !desperatep)&USED) |
a62e4ece MW |
780 | return (-1); |
781 | ||
782 | map_ipv4_sockaddr(&maddr.sin6, &waddr.sin); | |
74eb4869 | 783 | if (encode_single_inet_addr(&maddr.sa, &wsun, !desperatep)&USED) |
a62e4ece MW |
784 | return (-1); |
785 | ||
786 | wildcard_address(AF_INET6, &waddr.sa); | |
787 | port_to_sockaddr(&waddr.sa, port); | |
74eb4869 | 788 | if (encode_single_inet_addr(&waddr.sa, &wsun, !desperatep)&USED) |
a62e4ece MW |
789 | return (-1); |
790 | } | |
791 | ||
4b1a6174 | 792 | /* All is well. */ |
f6e0ea86 MW |
793 | return (0); |
794 | } | |
795 | ||
4b9d1fad MW |
796 | /* Encode the Internet address SA as a Unix-domain address SUN. If the flag |
797 | * `ENCF_FRESH' is set, and SA's port number is zero, then we pick an | |
798 | * arbitrary local port. Otherwise we pick the port given. There's an | |
799 | * unpleasant hack to find servers bound to local wildcard addresses. | |
800 | * Returns zero on success; -1 on failure. | |
1d1ccf4f | 801 | */ |
4b9d1fad | 802 | #define ENCF_FRESH 1u |
a59a964f | 803 | #define ENCF_REUSEADDR 2u |
e4976bb0 | 804 | static int encode_inet_addr(struct sockaddr_un *sun, |
9314b85a | 805 | const struct sockaddr *sa, |
4b9d1fad | 806 | unsigned f) |
e4976bb0 | 807 | { |
808 | int i; | |
3ef1fec9 | 809 | int desperatep = 0; |
9314b85a | 810 | address addr; |
a62e4ece | 811 | struct sockaddr_in6 sin6; |
d0e289af | 812 | int port = port_from_sockaddr(sa); |
74eb4869 | 813 | int rc; |
9314b85a | 814 | char buf[ADDRBUFSZ]; |
e4976bb0 | 815 | |
e397f0bd | 816 | D( fprintf(stderr, "noip(%d): encode %s (%s)", getpid(), |
9314b85a | 817 | present_sockaddr(sa, 0, buf, sizeof(buf)), |
4b9d1fad | 818 | (f&ENCF_FRESH) ? "FRESH" : "EXISTING"); ) |
4b1a6174 MW |
819 | |
820 | /* Start making the Unix-domain address. */ | |
e4976bb0 | 821 | sun->sun_family = AF_UNIX; |
4b1a6174 | 822 | |
4b9d1fad | 823 | if (port || !(f&ENCF_FRESH)) { |
4b1a6174 MW |
824 | |
825 | /* Try the address as given. If it's in use, or we don't necessarily | |
826 | * want an existing socket, then we're done. | |
827 | */ | |
74eb4869 | 828 | rc = encode_single_inet_addr(sa, sun, 0); |
a59a964f | 829 | if ((f&ENCF_REUSEADDR) && !(rc&LISTEN)) unlink(sun->sun_path); |
74eb4869 | 830 | if ((rc&USED) || (f&ENCF_FRESH)) goto found; |
4b1a6174 | 831 | |
a62e4ece MW |
832 | /* We're looking for a socket which already exists. This is |
833 | * unfortunately difficult, because we must deal both with wildcards and | |
834 | * v6-mapped IPv4 addresses. | |
835 | * | |
836 | * * We've just tried searching for a socket whose name is an exact | |
837 | * match for our remote address. If the remote address is IPv4, then | |
838 | * we should try again with the v6-mapped equivalent. | |
839 | * | |
840 | * * Failing that, we try again with the wildcard address for the | |
841 | * appropriate address family. | |
842 | * | |
843 | * * Failing /that/, if the remote address is IPv4, then we try | |
844 | * /again/, increasingly desperately, first with the v6-mapped IPv4 | |
845 | * wildcard address, and then with the IPv6 wildcard address. This | |
846 | * will cause magic v6-mapping to occur when the connection is | |
847 | * accepted, which we hope won't cause too much trouble. | |
4b1a6174 | 848 | */ |
a62e4ece MW |
849 | |
850 | if (sa->sa_family == AF_INET) { | |
851 | map_ipv4_sockaddr(&addr.sin6, SIN(sa)); | |
74eb4869 | 852 | if (encode_single_inet_addr(&addr.sa, sun, 0)&USED) goto found; |
a62e4ece MW |
853 | } |
854 | ||
aed729d0 MW |
855 | wildcard_address(sa->sa_family, &addr.sa); |
856 | port_to_sockaddr(&addr.sa, port); | |
74eb4869 | 857 | if (encode_single_inet_addr(&addr.sa, sun, 0)&USED) goto found; |
a62e4ece MW |
858 | |
859 | if (sa->sa_family == AF_INET) { | |
860 | map_ipv4_sockaddr(&sin6, &addr.sin); | |
74eb4869 | 861 | if (encode_single_inet_addr(SA(&sin6), sun, 0)&USED) goto found; |
a62e4ece MW |
862 | wildcard_address(AF_INET6, &addr.sa); |
863 | port_to_sockaddr(&addr.sa, port); | |
74eb4869 | 864 | if (encode_single_inet_addr(&addr.sa, sun, 0)&USED) goto found; |
a62e4ece MW |
865 | } |
866 | ||
867 | /* Well, this isn't going to work (unless a miraculous race is lost), but | |
868 | * we might as well try. | |
869 | */ | |
870 | encode_single_inet_addr(sa, sun, 1); | |
4b1a6174 | 871 | |
e4976bb0 | 872 | } else { |
4b1a6174 MW |
873 | /* We want a fresh new socket. */ |
874 | ||
875 | /* Make a copy of the given address, because we're going to mangle it. */ | |
9314b85a | 876 | copy_sockaddr(&addr.sa, sa); |
4b1a6174 MW |
877 | |
878 | /* Try a few random-ish port numbers to see if any of them is spare. */ | |
f6049fdd | 879 | for (i = 0; i < 10; i++) { |
9314b85a | 880 | port_to_sockaddr(&addr.sa, randrange(minautoport, maxautoport)); |
f6e0ea86 | 881 | if (!encode_unused_inet_addr(&addr.sa, sun, 0)) goto found; |
f6049fdd | 882 | } |
4b1a6174 MW |
883 | |
884 | /* Things must be getting tight. Work through all of the autoport range | |
885 | * to see if we can find a spare one. The first time, just do it the | |
886 | * quick way; if that doesn't work, then check harder for stale sockets. | |
887 | */ | |
3ef1fec9 | 888 | for (desperatep = 0; desperatep < 2; desperatep++) { |
f6049fdd | 889 | for (i = minautoport; i <= maxautoport; i++) { |
9314b85a | 890 | port_to_sockaddr(&addr.sa, i); |
f6e0ea86 | 891 | if (!encode_unused_inet_addr(&addr.sa, sun, 0)) goto found; |
e4976bb0 | 892 | } |
893 | } | |
4b1a6174 MW |
894 | |
895 | /* We failed to find any free ports. */ | |
e4976bb0 | 896 | errno = EADDRINUSE; |
897 | D( fprintf(stderr, " -- can't resolve\n"); ) | |
898 | return (-1); | |
e4976bb0 | 899 | } |
4b1a6174 MW |
900 | |
901 | /* Success. */ | |
5d8b1560 | 902 | found: |
e4976bb0 | 903 | D( fprintf(stderr, " -> `%s'\n", sun->sun_path); ) |
904 | return (0); | |
905 | } | |
906 | ||
9314b85a | 907 | /* Decode the Unix address SUN to an Internet address SIN. If AF_HINT is |
c0876c8c MW |
908 | * nonzero, an empty address (indicative of an unbound Unix-domain socket) is |
909 | * translated to a wildcard Internet address of the appropriate family. | |
910 | * Returns zero on success; -1 on failure (e.g., it wasn't one of our | |
911 | * addresses). | |
00a98a8a | 912 | */ |
9314b85a | 913 | static int decode_inet_addr(struct sockaddr *sa, int af_hint, |
e4976bb0 | 914 | const struct sockaddr_un *sun, |
9314b85a | 915 | socklen_t len) |
e4976bb0 | 916 | { |
9314b85a | 917 | char buf[ADDRBUFSZ]; |
a2114371 | 918 | size_t n = strlen(sockdir), nn; |
9314b85a | 919 | address addr; |
e4976bb0 | 920 | |
9314b85a MW |
921 | if (!sa) sa = &addr.sa; |
922 | if (sun->sun_family != AF_UNIX) return (-1); | |
923 | if (len > sizeof(*sun)) return (-1); | |
924 | ((char *)sun)[len] = 0; | |
a2114371 | 925 | nn = strlen(sun->sun_path); |
e397f0bd | 926 | D( fprintf(stderr, "noip(%d): decode `%s'", getpid(), sun->sun_path); ) |
9314b85a MW |
927 | if (af_hint && !sun->sun_path[0]) { |
928 | wildcard_address(af_hint, sa); | |
e4976bb0 | 929 | D( fprintf(stderr, " -- unbound socket\n"); ) |
930 | return (0); | |
931 | } | |
932 | if (nn < n + 1 || nn - n >= sizeof(buf) || sun->sun_path[n] != '/' || | |
933 | memcmp(sun->sun_path, sockdir, n) != 0) { | |
934 | D( fprintf(stderr, " -- not one of ours\n"); ) | |
935 | return (-1); | |
936 | } | |
9314b85a MW |
937 | if (parse_sockaddr(sa, sun->sun_path + n + 1)) return (-1); |
938 | D( fprintf(stderr, " -> %s\n", | |
939 | present_sockaddr(sa, 0, buf, sizeof(buf))); ) | |
e4976bb0 | 940 | return (0); |
941 | } | |
942 | ||
1d1ccf4f MW |
943 | /* SK is (or at least might be) a Unix-domain socket we created when an |
944 | * Internet socket was asked for. We've decided it should be an Internet | |
86134bfe MW |
945 | * socket after all, with family AF_HINT, so convert it. If TMP is not null, |
946 | * then don't replace the existing descriptor: store the new socket in *TMP | |
947 | * and return zero. | |
1d1ccf4f | 948 | */ |
86134bfe | 949 | static int fixup_real_ip_socket(int sk, int af_hint, int *tmp) |
e4976bb0 | 950 | { |
951 | int nsk; | |
952 | int type; | |
953 | int f, fd; | |
954 | struct sockaddr_un sun; | |
9314b85a | 955 | address addr; |
e4976bb0 | 956 | socklen_t len; |
957 | ||
958 | #define OPTS(_) \ | |
959 | _(DEBUG, int) \ | |
960 | _(REUSEADDR, int) \ | |
961 | _(DONTROUTE, int) \ | |
962 | _(BROADCAST, int) \ | |
963 | _(SNDBUF, int) \ | |
964 | _(RCVBUF, int) \ | |
965 | _(OOBINLINE, int) \ | |
966 | _(NO_CHECK, int) \ | |
967 | _(LINGER, struct linger) \ | |
968 | _(BSDCOMPAT, int) \ | |
969 | _(RCVLOWAT, int) \ | |
970 | _(RCVTIMEO, struct timeval) \ | |
971 | _(SNDTIMEO, struct timeval) | |
972 | ||
973 | len = sizeof(sun); | |
974 | if (real_getsockname(sk, SA(&sun), &len)) | |
975 | return (-1); | |
9314b85a | 976 | if (decode_inet_addr(&addr.sa, af_hint, &sun, len)) |
e4976bb0 | 977 | return (0); /* Not one of ours */ |
978 | len = sizeof(type); | |
979 | if (real_getsockopt(sk, SOL_SOCKET, SO_TYPE, &type, &len) < 0 || | |
9314b85a | 980 | (nsk = real_socket(addr.sa.sa_family, type, 0)) < 0) |
e4976bb0 | 981 | return (-1); |
982 | #define FIX(opt, ty) do { \ | |
983 | ty ov_; \ | |
984 | len = sizeof(ov_); \ | |
985 | if (real_getsockopt(sk, SOL_SOCKET, SO_##opt, &ov_, &len) < 0 || \ | |
986 | real_setsockopt(nsk, SOL_SOCKET, SO_##opt, &ov_, len)) { \ | |
9fb8e5c9 | 987 | close(nsk); \ |
e4976bb0 | 988 | return (-1); \ |
989 | } \ | |
990 | } while (0); | |
991 | OPTS(FIX) | |
992 | #undef FIX | |
86134bfe MW |
993 | if (tmp) |
994 | *tmp = nsk; | |
995 | else { | |
996 | if ((f = fcntl(sk, F_GETFL)) < 0 || | |
997 | (fd = fcntl(sk, F_GETFD)) < 0 || | |
998 | fcntl(nsk, F_SETFL, f) < 0 || | |
999 | dup2(nsk, sk) < 0) { | |
1000 | close(nsk); | |
1001 | return (-1); | |
1002 | } | |
1003 | unlink(sun.sun_path); | |
9fb8e5c9 | 1004 | close(nsk); |
86134bfe MW |
1005 | if (fcntl(sk, F_SETFD, fd) < 0) { |
1006 | perror("noip: fixup_real_ip_socket F_SETFD"); | |
1007 | abort(); | |
1008 | } | |
e4976bb0 | 1009 | } |
1010 | return (0); | |
1011 | } | |
1012 | ||
7be80f86 MW |
1013 | /* We found the real address SA, with length LEN; if it's a Unix-domain |
1014 | * address corresponding to a fake socket, convert it to cover up the | |
1015 | * deception. Whatever happens, put the result at FAKE and store its length | |
1016 | * at FAKELEN. | |
1017 | */ | |
a62e4ece | 1018 | #define FNF_V6MAPPED 1u |
7be80f86 | 1019 | static void return_fake_name(struct sockaddr *sa, socklen_t len, |
a62e4ece MW |
1020 | struct sockaddr *fake, socklen_t *fakelen, |
1021 | unsigned f) | |
7be80f86 MW |
1022 | { |
1023 | address addr; | |
a62e4ece | 1024 | struct sockaddr_in6 sin6; |
7be80f86 MW |
1025 | socklen_t alen; |
1026 | ||
1027 | if (sa->sa_family == AF_UNIX && | |
1028 | !decode_inet_addr(&addr.sa, 0, SUN(sa), len)) { | |
a62e4ece MW |
1029 | if (addr.sa.sa_family != AF_INET || !(f&FNF_V6MAPPED)) { |
1030 | sa = &addr.sa; | |
1031 | len = family_socklen(addr.sa.sa_family); | |
1032 | } else { | |
1033 | map_ipv4_sockaddr(&sin6, &addr.sin); | |
1034 | sa = SA(&sin6); | |
1035 | len = family_socklen(AF_INET6); | |
1036 | } | |
7be80f86 MW |
1037 | } |
1038 | alen = len; | |
1039 | if (len > *fakelen) len = *fakelen; | |
1040 | if (len > 0) memcpy(fake, sa, len); | |
1041 | *fakelen = alen; | |
1042 | } | |
1043 | ||
a62e4ece MW |
1044 | /* Variant of `return_fake_name' above, specifically handling the weirdness |
1045 | * of remote v6-mapped IPv4 addresses. If SK's fake local address is IPv6, | |
1046 | * and the remote address is IPv4, then return a v6-mapped version of the | |
1047 | * remote address. | |
1048 | */ | |
1049 | static void return_fake_peer(int sk, struct sockaddr *sa, socklen_t len, | |
1050 | struct sockaddr *fake, socklen_t *fakelen) | |
1051 | { | |
1052 | char sabuf[1024]; | |
1053 | socklen_t mylen = sizeof(sabuf); | |
1054 | unsigned fnf = 0; | |
1055 | address addr; | |
1056 | int rc; | |
1057 | ||
1058 | PRESERVING_ERRNO({ | |
1059 | rc = real_getsockname(sk, SA(sabuf), &mylen); | |
1060 | if (!rc && sa->sa_family == AF_UNIX && | |
1061 | !decode_inet_addr(&addr.sa, 0, SUN(sabuf), mylen) && | |
1062 | addr.sa.sa_family == AF_INET6) | |
1063 | fnf |= FNF_V6MAPPED; | |
1064 | }); | |
1065 | return_fake_name(sa, len, fake, fakelen, fnf); | |
1066 | } | |
1067 | ||
7be80f86 MW |
1068 | /*----- Implicit binding --------------------------------------------------*/ |
1069 | ||
1070 | #ifdef DEBUG | |
1071 | ||
1072 | static void dump_impbind(const impbind *i) | |
1073 | { | |
1074 | char buf[ADDRBUFSZ]; | |
1075 | ||
1076 | fprintf(stderr, "noip(%d): ", getpid()); | |
1077 | dump_addrrange(i->af, &i->minaddr, &i->maxaddr); | |
1078 | switch (i->how) { | |
1079 | case SAME: fprintf(stderr, " <self>"); break; | |
1080 | case EXPLICIT: | |
1081 | fprintf(stderr, " %s", inet_ntop(i->af, &i->bindaddr, | |
1082 | buf, sizeof(buf))); | |
1083 | break; | |
1084 | default: abort(); | |
1085 | } | |
1086 | fputc('\n', stderr); | |
1087 | } | |
1088 | ||
1089 | static void dump_impbind_list(void) | |
1090 | { | |
1091 | const impbind *i; | |
1092 | ||
1093 | for (i = impbinds; i; i = i->next) dump_impbind(i); | |
1094 | } | |
1095 | ||
1096 | #endif | |
1097 | ||
1d1ccf4f | 1098 | /* The socket SK is about to be used to communicate with the remote address |
9314b85a MW |
1099 | * SA. Assign it a local address so that getpeername(2) does something |
1100 | * useful. | |
a62e4ece MW |
1101 | * |
1102 | * If the flag `IBF_V6MAPPED' is set then, then SA must be an `AF_INET' | |
1103 | * address; after deciding on the appropriate local address, convert it to be | |
1104 | * an IPv4-mapped IPv6 address before final conversion to a Unix-domain | |
1105 | * socket address and actually binding. Note that this could well mean that | |
1106 | * the socket ends up bound to the v6-mapped v4 wildcard address | |
1107 | * ::ffff:0.0.0.0, which looks very strange but is meaningful. | |
1d1ccf4f | 1108 | */ |
a62e4ece MW |
1109 | #define IBF_V6MAPPED 1u |
1110 | static int do_implicit_bind(int sk, const struct sockaddr *sa, unsigned f) | |
e4976bb0 | 1111 | { |
9314b85a | 1112 | address addr; |
a62e4ece | 1113 | struct sockaddr_in6 sin6; |
6e1fe695 | 1114 | struct sockaddr_un sun; |
7be80f86 MW |
1115 | const impbind *i; |
1116 | Dpid; | |
e4976bb0 | 1117 | |
6e1fe695 MW |
1118 | D( fprintf(stderr, "noip(%d): checking impbind list...\n", pid); ) |
1119 | for (i = impbinds; i; i = i->next) { | |
1120 | D( dump_impbind(i); ) | |
1121 | if (sa->sa_family == i->af && | |
1122 | sockaddr_in_range_p(sa, &i->minaddr, &i->maxaddr)) { | |
1123 | D( fprintf(stderr, "noip(%d): match!\n", pid); ) | |
1124 | addr.sa.sa_family = sa->sa_family; | |
1125 | ipaddr_to_sockaddr(&addr.sa, &i->bindaddr); | |
1126 | goto found; | |
e4976bb0 | 1127 | } |
1128 | } | |
6e1fe695 MW |
1129 | D( fprintf(stderr, "noip(%d): no match; using wildcard\n", pid); ) |
1130 | wildcard_address(sa->sa_family, &addr.sa); | |
1131 | found: | |
a62e4ece MW |
1132 | if (addr.sa.sa_family != AF_INET || !(f&IBF_V6MAPPED)) sa = &addr.sa; |
1133 | else { map_ipv4_sockaddr(&sin6, &addr.sin); sa = SA(&sin6); } | |
1134 | encode_inet_addr(&sun, sa, ENCF_FRESH); | |
43598265 MW |
1135 | D( fprintf(stderr, "noip(%d): implicitly binding to %s\n", |
1136 | pid, sun.sun_path); ) | |
6e1fe695 MW |
1137 | if (real_bind(sk, SA(&sun), SUN_LEN(&sun))) return (-1); |
1138 | return (0); | |
1139 | } | |
1140 | ||
1141 | /* The socket SK is about to communicate with the remote address *SA. Ensure | |
1142 | * that the socket has a local address, and adjust *SA to refer to the real | |
1143 | * remote endpoint. | |
1144 | * | |
1145 | * If we need to translate the remote address, then the Unix-domain endpoint | |
1146 | * address will end in *SUN, and *SA will be adjusted to point to it. | |
1147 | */ | |
1148 | static int fixup_client_socket(int sk, const struct sockaddr **sa_r, | |
1149 | socklen_t *len_r, struct sockaddr_un *sun) | |
1150 | { | |
a62e4ece | 1151 | struct sockaddr_in sin; |
6e1fe695 MW |
1152 | socklen_t mylen = sizeof(*sun); |
1153 | const struct sockaddr *sa = *sa_r; | |
a62e4ece | 1154 | unsigned ibf = 0; |
6e1fe695 | 1155 | |
7d7cba35 MW |
1156 | /* If this isn't a Unix-domain socket then there's nothing to do. */ |
1157 | if (real_getsockname(sk, SA(sun), &mylen) < 0) return (-1); | |
1158 | if (sun->sun_family != AF_UNIX) return (0); | |
1159 | if (mylen < sizeof(*sun)) ((char *)sun)[mylen] = 0; | |
1160 | ||
a62e4ece MW |
1161 | /* If the remote address is v6-mapped IPv4, then unmap it so as to search |
1162 | * for IPv4 servers. Also remember to v6-map the local address when we | |
1163 | * autobind. | |
1164 | */ | |
1165 | if (sa->sa_family == AF_INET6 && !(unmap_ipv4_sockaddr(&sin, SIN6(sa)))) { | |
1166 | sa = SA(&sin); | |
1167 | ibf |= IBF_V6MAPPED; | |
1168 | } | |
1169 | ||
6e1fe695 MW |
1170 | /* If we're allowed to talk to a real remote endpoint, then fix things up |
1171 | * as necessary and proceed. | |
1172 | */ | |
1173 | if (acl_allows_p(connect_real, sa)) { | |
1174 | if (fixup_real_ip_socket(sk, (*sa_r)->sa_family, 0)) return (-1); | |
1175 | return (0); | |
1176 | } | |
1177 | ||
6e1fe695 MW |
1178 | /* Speaking of which, if we don't have a local address, then we should |
1179 | * arrange one now. | |
1180 | */ | |
a62e4ece | 1181 | if (!sun->sun_path[0] && do_implicit_bind(sk, sa, ibf)) return (-1); |
6e1fe695 MW |
1182 | |
1183 | /* And then come up with a remote address. */ | |
1184 | encode_inet_addr(sun, sa, 0); | |
1185 | *sa_r = SA(sun); | |
1186 | *len_r = SUN_LEN(sun); | |
e4976bb0 | 1187 | return (0); |
1188 | } | |
1189 | ||
1d1ccf4f | 1190 | /*----- Configuration -----------------------------------------------------*/ |
e4976bb0 | 1191 | |
1d1ccf4f | 1192 | /* Return the process owner's home directory. */ |
e4976bb0 | 1193 | static char *home(void) |
1194 | { | |
1195 | char *p; | |
1196 | struct passwd *pw; | |
1197 | ||
3ef1fec9 | 1198 | if (getuid() == uid && |
1199 | (p = getenv("HOME")) != 0) | |
1200 | return (p); | |
1201 | else if ((pw = getpwuid(uid)) != 0) | |
1202 | return (pw->pw_dir); | |
1203 | else | |
1204 | return "/notexist"; | |
e4976bb0 | 1205 | } |
1206 | ||
1d1ccf4f | 1207 | /* Return a good temporary directory to use. */ |
e4976bb0 | 1208 | static char *tmpdir(void) |
1209 | { | |
1210 | char *p; | |
1211 | ||
1212 | if ((p = getenv("TMPDIR")) != 0) return (p); | |
1213 | else if ((p = getenv("TMP")) != 0) return (p); | |
1214 | else return ("/tmp"); | |
1215 | } | |
1216 | ||
1d1ccf4f | 1217 | /* Return the user's name, or at least something distinctive. */ |
e4976bb0 | 1218 | static char *user(void) |
1219 | { | |
1220 | static char buf[16]; | |
1221 | char *p; | |
1222 | struct passwd *pw; | |
1223 | ||
1224 | if ((p = getenv("USER")) != 0) return (p); | |
1225 | else if ((p = getenv("LOGNAME")) != 0) return (p); | |
1226 | else if ((pw = getpwuid(uid)) != 0) return (pw->pw_name); | |
1227 | else { | |
1228 | snprintf(buf, sizeof(buf), "uid-%lu", (unsigned long)uid); | |
1229 | return (buf); | |
1230 | } | |
1231 | } | |
1232 | ||
1d1ccf4f | 1233 | /* Skip P over space characters. */ |
e4976bb0 | 1234 | #define SKIPSPC do { while (*p && isspace(UC(*p))) p++; } while (0) |
1d1ccf4f MW |
1235 | |
1236 | /* Set Q to point to the next word following P, null-terminate it, and step P | |
1237 | * past it. */ | |
e4976bb0 | 1238 | #define NEXTWORD(q) do { \ |
1239 | SKIPSPC; \ | |
1240 | q = p; \ | |
1241 | while (*p && !isspace(UC(*p))) p++; \ | |
1242 | if (*p) *p++ = 0; \ | |
1243 | } while (0) | |
1d1ccf4f MW |
1244 | |
1245 | /* Set Q to point to the next dotted-quad address, store the ending delimiter | |
1246 | * in DEL, null-terminate it, and step P past it. */ | |
9314b85a MW |
1247 | static void parse_nextaddr(char **pp, char **qq, int *del) |
1248 | { | |
1249 | char *p = *pp; | |
1250 | ||
1251 | SKIPSPC; | |
1252 | if (*p == '[') { | |
1253 | p++; SKIPSPC; | |
1254 | *qq = p; | |
1255 | p += strcspn(p, "]"); | |
1256 | if (*p) *p++ = 0; | |
1257 | *del = 0; | |
1258 | } else { | |
1259 | *qq = p; | |
1260 | while (*p && (*p == '.' || isdigit(UC(*p)))) p++; | |
1261 | *del = *p; | |
1262 | if (*p) *p++ = 0; | |
1263 | } | |
1264 | *pp = p; | |
1265 | } | |
1d1ccf4f MW |
1266 | |
1267 | /* Set Q to point to the next decimal number, store the ending delimiter in | |
1268 | * DEL, null-terminate it, and step P past it. */ | |
e4976bb0 | 1269 | #define NEXTNUMBER(q, del) do { \ |
1270 | SKIPSPC; \ | |
1271 | q = p; \ | |
1272 | while (*p && isdigit(UC(*p))) p++; \ | |
1273 | del = *p; \ | |
1274 | if (*p) *p++ = 0; \ | |
1275 | } while (0) | |
1d1ccf4f MW |
1276 | |
1277 | /* Push the character DEL back so we scan it again, unless it's zero | |
1278 | * (end-of-file). */ | |
e4976bb0 | 1279 | #define RESCAN(del) do { if (del) *--p = del; } while (0) |
1d1ccf4f MW |
1280 | |
1281 | /* Evaluate true if P is pointing to the word KW (and not some longer string | |
1282 | * of which KW is a prefix). */ | |
1283 | ||
e4976bb0 | 1284 | #define KWMATCHP(kw) (strncmp(p, kw, sizeof(kw) - 1) == 0 && \ |
1285 | !isalnum(UC(p[sizeof(kw) - 1])) && \ | |
1286 | (p += sizeof(kw) - 1)) | |
9f82ba1f | 1287 | |
1d1ccf4f MW |
1288 | /* Parse a port list, starting at *PP. Port lists have the form |
1289 | * [:LOW[-HIGH]]: if omitted, all ports are included; if HIGH is omitted, | |
1290 | * it's as if HIGH = LOW. Store LOW in *MIN, HIGH in *MAX and set *PP to the | |
1291 | * rest of the string. | |
1292 | */ | |
e4976bb0 | 1293 | static void parse_ports(char **pp, unsigned short *min, unsigned short *max) |
1294 | { | |
1295 | char *p = *pp, *q; | |
1296 | int del; | |
1297 | ||
1298 | SKIPSPC; | |
f6049fdd | 1299 | if (*p != ':') |
1300 | { *min = 0; *max = 0xffff; } | |
1301 | else { | |
e4976bb0 | 1302 | p++; |
f6049fdd | 1303 | NEXTNUMBER(q, del); *min = strtoul(q, 0, 0); RESCAN(del); |
e4976bb0 | 1304 | SKIPSPC; |
f6049fdd | 1305 | if (*p == '-') |
d83beb5c | 1306 | { p++; NEXTNUMBER(q, del); *max = strtoul(q, 0, 0); RESCAN(del); } |
f6049fdd | 1307 | else |
e4976bb0 | 1308 | *max = *min; |
1309 | } | |
1310 | *pp = p; | |
1311 | } | |
1312 | ||
006dd63f MW |
1313 | /* Parse an address range designator starting at PP and store a |
1314 | * representation of it in R. An address range designator has the form: | |
1315 | * | |
1316 | * any | local | ADDR | ADDR - ADDR | ADDR/ADDR | ADDR/INT | |
1d1ccf4f | 1317 | */ |
006dd63f | 1318 | static int parse_addrrange(char **pp, addrrange *r) |
e4976bb0 | 1319 | { |
006dd63f MW |
1320 | char *p = *pp, *q; |
1321 | int n; | |
e4976bb0 | 1322 | int del; |
006dd63f | 1323 | int af; |
e4976bb0 | 1324 | |
006dd63f MW |
1325 | SKIPSPC; |
1326 | if (KWMATCHP("any")) r->type = ANY; | |
1327 | else if (KWMATCHP("local")) r->type = LOCAL; | |
1328 | else { | |
1329 | parse_nextaddr(&p, &q, &del); | |
1330 | af = guess_address_family(q); | |
1331 | if (inet_pton(af, q, &r->u.range.min) <= 0) goto bad; | |
1332 | RESCAN(del); | |
a6d9626b | 1333 | SKIPSPC; |
006dd63f MW |
1334 | if (*p == '-') { |
1335 | p++; | |
1336 | parse_nextaddr(&p, &q, &del); | |
1337 | if (inet_pton(af, q, &r->u.range.max) <= 0) goto bad; | |
1338 | RESCAN(del); | |
1339 | } else if (*p == '/') { | |
1340 | p++; | |
1341 | NEXTNUMBER(q, del); | |
1342 | n = strtoul(q, 0, 0); | |
1343 | r->u.range.max = r->u.range.min; | |
1344 | mask_address(af, &r->u.range.min, n, 0); | |
1345 | mask_address(af, &r->u.range.max, n, 1); | |
1346 | RESCAN(del); | |
1347 | } else | |
1348 | r->u.range.max = r->u.range.min; | |
1349 | r->type = RANGE; | |
1350 | r->u.range.af = af; | |
1351 | } | |
1352 | *pp = p; | |
1353 | return (0); | |
e4976bb0 | 1354 | |
006dd63f MW |
1355 | bad: |
1356 | return (-1); | |
1357 | } | |
1358 | ||
1359 | /* Call FUNC on each individual address range in R. */ | |
1360 | static void foreach_addrrange(const addrrange *r, | |
1361 | void (*func)(int af, | |
1362 | const ipaddr *min, | |
1363 | const ipaddr *max, | |
1364 | void *p), | |
1365 | void *p) | |
1366 | { | |
1367 | ipaddr minaddr, maxaddr; | |
1368 | int i, af; | |
1369 | ||
1370 | switch (r->type) { | |
1371 | case EMPTY: | |
1372 | break; | |
1373 | case ANY: | |
9314b85a MW |
1374 | for (i = 0; address_families[i] >= 0; i++) { |
1375 | af = address_families[i]; | |
1376 | memset(&minaddr, 0, sizeof(minaddr)); | |
1377 | maxaddr = minaddr; mask_address(af, &maxaddr, 0, 1); | |
006dd63f | 1378 | func(af, &minaddr, &maxaddr, p); |
9314b85a | 1379 | } |
006dd63f MW |
1380 | break; |
1381 | case LOCAL: | |
9314b85a MW |
1382 | for (i = 0; address_families[i] >= 0; i++) { |
1383 | af = address_families[i]; | |
1384 | memset(&minaddr, 0, sizeof(minaddr)); | |
1385 | maxaddr = minaddr; mask_address(af, &maxaddr, 0, 1); | |
006dd63f MW |
1386 | func(af, &minaddr, &minaddr, p); |
1387 | func(af, &maxaddr, &maxaddr, p); | |
9314b85a | 1388 | } |
a6d9626b | 1389 | for (i = 0; i < n_local_ipaddrs; i++) { |
006dd63f MW |
1390 | func(local_ipaddrs[i].af, |
1391 | &local_ipaddrs[i].addr, &local_ipaddrs[i].addr, | |
1392 | p); | |
a6d9626b | 1393 | } |
006dd63f MW |
1394 | break; |
1395 | case RANGE: | |
1396 | func(r->u.range.af, &r->u.range.min, &r->u.range.max, p); | |
1397 | break; | |
1398 | default: | |
1399 | abort(); | |
1400 | } | |
1401 | } | |
1402 | ||
1403 | struct add_aclnode_ctx { | |
1404 | int act; | |
1405 | unsigned short minport, maxport; | |
1406 | aclnode ***tail; | |
1407 | }; | |
1408 | ||
1409 | static void add_aclnode(int af, const ipaddr *min, const ipaddr *max, | |
1410 | void *p) | |
1411 | { | |
1412 | struct add_aclnode_ctx *ctx = p; | |
1413 | aclnode *a; | |
1414 | ||
1415 | NEW(a); | |
1416 | a->act = ctx->act; | |
1417 | a->af = af; | |
1418 | a->minaddr = *min; a->maxaddr = *max; | |
1419 | a->minport = ctx->minport; a->maxport = ctx->maxport; | |
1420 | **ctx->tail = a; *ctx->tail = &a->next; | |
1421 | } | |
1422 | ||
1423 | /* Parse an ACL line. *PP points to the end of the line; *TAIL points to | |
1424 | * the list tail (i.e., the final link in the list). An ACL entry has the | |
1425 | * form +|- ADDR-RANGE PORTS | |
1426 | * where PORTS is parsed by parse_ports above; an ACL line consists of a | |
1427 | * comma-separated sequence of entries.. | |
1428 | */ | |
1429 | static void parse_acl_line(char **pp, aclnode ***tail) | |
1430 | { | |
1431 | struct add_aclnode_ctx ctx; | |
1432 | addrrange r; | |
1433 | char *p = *pp; | |
1434 | ||
1435 | ctx.tail = tail; | |
1436 | for (;;) { | |
1437 | SKIPSPC; | |
1438 | if (*p == '+') ctx.act = ALLOW; | |
1439 | else if (*p == '-') ctx.act = DENY; | |
1440 | else goto bad; | |
1441 | ||
1442 | p++; | |
1443 | if (parse_addrrange(&p, &r)) goto bad; | |
1444 | parse_ports(&p, &ctx.minport, &ctx.maxport); | |
1445 | foreach_addrrange(&r, add_aclnode, &ctx); | |
a6d9626b | 1446 | SKIPSPC; |
1447 | if (*p != ',') break; | |
1cce4a41 | 1448 | if (*p) p++; |
e4976bb0 | 1449 | } |
67fd355a | 1450 | if (*p) goto bad; |
f797ea6d | 1451 | *pp = p; |
e4976bb0 | 1452 | return; |
1453 | ||
1454 | bad: | |
e397f0bd | 1455 | D( fprintf(stderr, "noip(%d): bad acl spec (ignored)\n", getpid()); ) |
e4976bb0 | 1456 | return; |
1457 | } | |
1458 | ||
051fa2d8 MW |
1459 | /* Parse an ACL from an environment variable VAR, attaching it to the list |
1460 | * TAIL. | |
1461 | */ | |
1462 | static void parse_acl_env(const char *var, aclnode ***tail) | |
1463 | { | |
1464 | char *p, *q; | |
1465 | ||
1466 | if ((p = getenv(var)) != 0) { | |
1467 | p = q = xstrdup(p); | |
1468 | parse_acl_line(&q, tail); | |
1469 | free(p); | |
1470 | } | |
1471 | } | |
1472 | ||
7be80f86 MW |
1473 | struct add_impbind_ctx { |
1474 | int af, how; | |
1475 | ipaddr addr; | |
1476 | }; | |
1477 | ||
1478 | static void add_impbind(int af, const ipaddr *min, const ipaddr *max, | |
1479 | void *p) | |
1480 | { | |
1481 | struct add_impbind_ctx *ctx = p; | |
1482 | impbind *i; | |
1483 | ||
1484 | if (ctx->af && af != ctx->af) return; | |
1485 | NEW(i); | |
1486 | i->af = af; | |
1487 | i->how = ctx->how; | |
1488 | i->minaddr = *min; i->maxaddr = *max; | |
1489 | switch (ctx->how) { | |
1490 | case EXPLICIT: i->bindaddr = ctx->addr; | |
1491 | case SAME: break; | |
1492 | default: abort(); | |
1493 | } | |
1494 | *impbind_tail = i; impbind_tail = &i->next; | |
1495 | } | |
1496 | ||
1497 | /* Parse an implicit-bind line. An implicit-bind entry has the form | |
1498 | * ADDR-RANGE {ADDR | same} | |
1499 | */ | |
1500 | static void parse_impbind_line(char **pp) | |
1501 | { | |
1502 | struct add_impbind_ctx ctx; | |
1503 | char *p = *pp, *q; | |
1504 | addrrange r; | |
1505 | int del; | |
1506 | ||
1507 | for (;;) { | |
1508 | if (parse_addrrange(&p, &r)) goto bad; | |
1509 | SKIPSPC; | |
1510 | if (KWMATCHP("same")) { | |
1511 | ctx.how = SAME; | |
1512 | ctx.af = 0; | |
1513 | } else { | |
1514 | ctx.how = EXPLICIT; | |
1515 | parse_nextaddr(&p, &q, &del); | |
1516 | ctx.af = guess_address_family(q); | |
1517 | if (inet_pton(ctx.af, q, &ctx.addr) < 0) goto bad; | |
1518 | RESCAN(del); | |
1519 | } | |
1520 | foreach_addrrange(&r, add_impbind, &ctx); | |
1521 | SKIPSPC; | |
1522 | if (*p != ',') break; | |
1523 | if (*p) p++; | |
1524 | } | |
1525 | if (*p) goto bad; | |
1526 | *pp = p; | |
1527 | return; | |
1528 | ||
1529 | bad: | |
1530 | D( fprintf(stderr, "noip(%d): bad implicit-bind spec (ignored)\n", | |
1531 | getpid()); ) | |
1532 | return; | |
1533 | } | |
1534 | ||
1535 | /* Parse implicit-bind instructions from an environment variable VAR, | |
1536 | * attaching it to the list. | |
1537 | */ | |
1538 | static void parse_impbind_env(const char *var) | |
1539 | { | |
1540 | char *p, *q; | |
1541 | ||
1542 | if ((p = getenv(var)) != 0) { | |
1543 | p = q = xstrdup(p); | |
1544 | parse_impbind_line(&q); | |
1545 | free(p); | |
1546 | } | |
1547 | } | |
1548 | ||
1d1ccf4f | 1549 | /* Parse the autoports configuration directive. Syntax is MIN - MAX. */ |
f6049fdd | 1550 | static void parse_autoports(char **pp) |
1551 | { | |
1552 | char *p = *pp, *q; | |
1553 | unsigned x, y; | |
1554 | int del; | |
1555 | ||
1556 | SKIPSPC; | |
1557 | NEXTNUMBER(q, del); x = strtoul(q, 0, 0); RESCAN(del); | |
1558 | SKIPSPC; | |
c6569cc9 MW |
1559 | if (*p != '-') goto bad; |
1560 | p++; | |
f6049fdd | 1561 | NEXTNUMBER(q, del); y = strtoul(q, 0, 0); RESCAN(del); |
1562 | minautoport = x; maxautoport = y; | |
67fd355a | 1563 | SKIPSPC; if (*p) goto bad; |
f797ea6d | 1564 | *pp = p; |
f6049fdd | 1565 | return; |
1566 | ||
1567 | bad: | |
e397f0bd | 1568 | D( fprintf(stderr, "noip(%d): bad port range (ignored)\n", getpid()); ) |
f6049fdd | 1569 | return; |
1570 | } | |
1571 | ||
1d1ccf4f | 1572 | /* Read the configuration from the config file and environment. */ |
e4976bb0 | 1573 | static void readconfig(void) |
1574 | { | |
1575 | FILE *fp; | |
1576 | char buf[1024]; | |
1577 | size_t n; | |
f6049fdd | 1578 | char *p, *q, *cmd; |
e397f0bd | 1579 | Dpid; |
e4976bb0 | 1580 | |
a6d9626b | 1581 | parse_acl_env("NOIP_REALBIND_BEFORE", &bind_tail); |
1582 | parse_acl_env("NOIP_REALCONNECT_BEFORE", &connect_tail); | |
7be80f86 | 1583 | parse_impbind_env("NOIP_IMPBIND_BEFORE"); |
f6049fdd | 1584 | if ((p = getenv("NOIP_AUTOPORTS")) != 0) { |
1585 | p = q = xstrdup(p); | |
1586 | parse_autoports(&q); | |
1587 | free(p); | |
1588 | } | |
4ab301de | 1589 | if ((p = getenv("NOIP_CONFIG")) == 0) |
1590 | snprintf(p = buf, sizeof(buf), "%s/.noip", home()); | |
e397f0bd | 1591 | D( fprintf(stderr, "noip(%d): config file: %s\n", pid, p); ) |
4ab301de | 1592 | |
1593 | if ((fp = fopen(p, "r")) == 0) { | |
e397f0bd MW |
1594 | D( fprintf(stderr, "noip(%d): couldn't read config: %s\n", |
1595 | pid, strerror(errno)); ) | |
f6049fdd | 1596 | goto done; |
4ab301de | 1597 | } |
e4976bb0 | 1598 | while (fgets(buf, sizeof(buf), fp)) { |
1599 | n = strlen(buf); | |
1600 | p = buf; | |
1601 | ||
1602 | SKIPSPC; | |
1603 | if (!*p || *p == '#') continue; | |
1604 | while (n && isspace(UC(buf[n - 1]))) n--; | |
1605 | buf[n] = 0; | |
1606 | NEXTWORD(cmd); | |
1607 | SKIPSPC; | |
1608 | ||
1609 | if (strcmp(cmd, "socketdir") == 0) | |
1610 | sockdir = xstrdup(p); | |
1611 | else if (strcmp(cmd, "realbind") == 0) | |
1612 | parse_acl_line(&p, &bind_tail); | |
1613 | else if (strcmp(cmd, "realconnect") == 0) | |
1614 | parse_acl_line(&p, &connect_tail); | |
7be80f86 MW |
1615 | else if (strcmp(cmd, "impbind") == 0) |
1616 | parse_impbind_line(&p); | |
f6049fdd | 1617 | else if (strcmp(cmd, "autoports") == 0) |
1618 | parse_autoports(&p); | |
e4976bb0 | 1619 | else if (strcmp(cmd, "debug") == 0) |
1620 | debug = *p ? atoi(p) : 1; | |
1621 | else | |
7be80f86 | 1622 | D( fprintf(stderr, "noip(%d): bad config command %s\n", pid, cmd); ) |
e4976bb0 | 1623 | } |
1624 | fclose(fp); | |
1625 | ||
1626 | done: | |
a6d9626b | 1627 | parse_acl_env("NOIP_REALBIND", &bind_tail); |
1628 | parse_acl_env("NOIP_REALCONNECT", &connect_tail); | |
7be80f86 | 1629 | parse_impbind_env("NOIP_IMPBIND"); |
a6d9626b | 1630 | parse_acl_env("NOIP_REALBIND_AFTER", &bind_tail); |
1631 | parse_acl_env("NOIP_REALCONNECT_AFTER", &connect_tail); | |
7be80f86 | 1632 | parse_impbind_env("NOIP_IMPBIND_AFTER"); |
e4976bb0 | 1633 | *bind_tail = 0; |
1634 | *connect_tail = 0; | |
7be80f86 | 1635 | *impbind_tail = 0; |
a6d9626b | 1636 | if (!sockdir) sockdir = getenv("NOIP_SOCKETDIR"); |
e4976bb0 | 1637 | if (!sockdir) { |
1638 | snprintf(buf, sizeof(buf), "%s/noip-%s", tmpdir(), user()); | |
1639 | sockdir = xstrdup(buf); | |
1640 | } | |
e397f0bd MW |
1641 | D( fprintf(stderr, "noip(%d): socketdir: %s\n", pid, sockdir); |
1642 | fprintf(stderr, "noip(%d): autoports: %u-%u\n", | |
1643 | pid, minautoport, maxautoport); | |
1644 | fprintf(stderr, "noip(%d): realbind acl:\n", pid); | |
e4976bb0 | 1645 | dump_acl(bind_real); |
e397f0bd | 1646 | fprintf(stderr, "noip(%d): realconnect acl:\n", pid); |
7be80f86 MW |
1647 | dump_acl(connect_real); |
1648 | fprintf(stderr, "noip(%d): impbind list:\n", pid); | |
1649 | dump_impbind_list(); ) | |
e4976bb0 | 1650 | } |
1651 | ||
1d1ccf4f | 1652 | /*----- Overridden system calls -------------------------------------------*/ |
e4976bb0 | 1653 | |
dc3956b3 MW |
1654 | static void dump_syserr(long rc) |
1655 | { fprintf(stderr, " => %ld (E%d)\n", rc, errno); } | |
1656 | ||
1657 | static void dump_sysresult(long rc) | |
1658 | { | |
1659 | if (rc < 0) dump_syserr(rc); | |
1660 | else fprintf(stderr, " => %ld\n", rc); | |
1661 | } | |
1662 | ||
1663 | static void dump_addrresult(long rc, const struct sockaddr *sa, | |
1664 | socklen_t len) | |
1665 | { | |
1666 | char addrbuf[ADDRBUFSZ]; | |
1667 | ||
1668 | if (rc < 0) dump_syserr(rc); | |
1669 | else { | |
1670 | fprintf(stderr, " => %ld [%s]\n", rc, | |
1671 | present_sockaddr(sa, len, addrbuf, sizeof(addrbuf))); | |
1672 | } | |
1673 | } | |
1674 | ||
e4976bb0 | 1675 | int socket(int pf, int ty, int proto) |
1676 | { | |
dc3956b3 MW |
1677 | int sk; |
1678 | ||
1679 | D( fprintf(stderr, "noip(%d): SOCKET pf=%d, type=%d, proto=%d", | |
1680 | getpid(), pf, ty, proto); ) | |
1681 | ||
8ce11853 | 1682 | switch (pf) { |
9314b85a MW |
1683 | default: |
1684 | if (!family_known_p(pf)) { | |
dc3956b3 | 1685 | D( fprintf(stderr, " -> unknown; refuse\n"); ) |
9314b85a | 1686 | errno = EAFNOSUPPORT; |
dc3956b3 | 1687 | sk = -1; |
9314b85a | 1688 | } |
dc3956b3 | 1689 | D( fprintf(stderr, " -> inet; substitute"); ) |
8ce11853 MW |
1690 | pf = PF_UNIX; |
1691 | proto = 0; | |
dc3956b3 | 1692 | break; |
8ce11853 | 1693 | case PF_UNIX: |
41c50995 MW |
1694 | #ifdef PF_NETLINK |
1695 | case PF_NETLINK: | |
1696 | #endif | |
dc3956b3 MW |
1697 | D( fprintf(stderr, " -> safe; permit"); ) |
1698 | break; | |
e4976bb0 | 1699 | } |
dc3956b3 MW |
1700 | sk = real_socket(pf, ty, proto); |
1701 | D( dump_sysresult(sk); ) | |
1702 | return (sk); | |
e4976bb0 | 1703 | } |
1704 | ||
1705 | int socketpair(int pf, int ty, int proto, int *sk) | |
1706 | { | |
dc3956b3 MW |
1707 | int rc; |
1708 | ||
1709 | D( fprintf(stderr, "noip(%d): SOCKETPAIR pf=%d, type=%d, proto=%d", | |
1710 | getpid(), pf, ty, proto); ) | |
1711 | if (!family_known_p(pf)) | |
1712 | D( fprintf(stderr, " -> unknown; permit"); ) | |
1713 | else { | |
1714 | D( fprintf(stderr, " -> inet; substitute"); ) | |
e4976bb0 | 1715 | pf = PF_UNIX; |
1716 | proto = 0; | |
1717 | } | |
dc3956b3 MW |
1718 | rc = real_socketpair(pf, ty, proto, sk); |
1719 | D( if (rc < 0) dump_syserr(rc); | |
1720 | else fprintf(stderr, " => %d (%d, %d)\n", rc, sk[0], sk[1]); ) | |
1721 | return (rc); | |
e4976bb0 | 1722 | } |
1723 | ||
1724 | int bind(int sk, const struct sockaddr *sa, socklen_t len) | |
1725 | { | |
1726 | struct sockaddr_un sun; | |
dc3956b3 | 1727 | int rc; |
a59a964f MW |
1728 | unsigned f; |
1729 | int reusep; | |
1730 | socklen_t n; | |
dc3956b3 | 1731 | Dpid; |
e4976bb0 | 1732 | |
dc3956b3 MW |
1733 | D({ char buf[ADDRBUFSZ]; |
1734 | fprintf(stderr, "noip(%d): BIND sk=%d, sa[%d]=%s", pid, | |
1735 | sk, len, present_sockaddr(sa, len, buf, sizeof(buf))); }) | |
1736 | ||
1737 | if (!family_known_p(sa->sa_family)) | |
1738 | D( fprintf(stderr, " -> unknown af; pass through"); ) | |
1739 | else { | |
1740 | D( fprintf(stderr, " -> checking...\n"); ) | |
e4976bb0 | 1741 | PRESERVING_ERRNO({ |
9314b85a | 1742 | if (acl_allows_p(bind_real, sa)) { |
86134bfe | 1743 | if (fixup_real_ip_socket(sk, sa->sa_family, 0)) |
e4976bb0 | 1744 | return (-1); |
1745 | } else { | |
a59a964f MW |
1746 | f = ENCF_FRESH; |
1747 | n = sizeof(reusep); | |
1748 | if (!getsockopt(sk, SOL_SOCKET, SO_REUSEADDR, &reusep, &n) && reusep) | |
1749 | f |= ENCF_REUSEADDR; | |
1750 | encode_inet_addr(&sun, sa, f); | |
e4976bb0 | 1751 | sa = SA(&sun); |
1752 | len = SUN_LEN(&sun); | |
1753 | } | |
1754 | }); | |
dc3956b3 | 1755 | D( fprintf(stderr, "noip(%d): BIND ...", pid); ) |
e4976bb0 | 1756 | } |
dc3956b3 MW |
1757 | rc = real_bind(sk, sa, len); |
1758 | D( dump_sysresult(rc); ) | |
1759 | return (rc); | |
e4976bb0 | 1760 | } |
1761 | ||
1762 | int connect(int sk, const struct sockaddr *sa, socklen_t len) | |
1763 | { | |
1764 | struct sockaddr_un sun; | |
53390eff | 1765 | int rc; |
dc3956b3 | 1766 | Dpid; |
e4976bb0 | 1767 | |
dc3956b3 MW |
1768 | D({ char buf[ADDRBUFSZ]; |
1769 | fprintf(stderr, "noip(%d): CONNECT sk=%d, sa[%d]=%s", pid, | |
1770 | sk, len, present_sockaddr(sa, len, buf, sizeof(buf))); }) | |
1771 | ||
1772 | if (!family_known_p(sa->sa_family)) { | |
1773 | D( fprintf(stderr, " -> unknown af; pass through"); ) | |
9314b85a | 1774 | rc = real_connect(sk, sa, len); |
dc3956b3 MW |
1775 | } else { |
1776 | D( fprintf(stderr, " -> checking...\n"); ) | |
9314b85a | 1777 | PRESERVING_ERRNO({ |
6e1fe695 | 1778 | fixup_client_socket(sk, &sa, &len, &sun); |
9314b85a | 1779 | }); |
dc3956b3 | 1780 | D( fprintf(stderr, "noip(%d): CONNECT ...", pid); ) |
9314b85a MW |
1781 | rc = real_connect(sk, sa, len); |
1782 | if (rc < 0) { | |
1783 | switch (errno) { | |
1784 | case ENOENT: errno = ECONNREFUSED; break; | |
6df6f816 | 1785 | } |
9314b85a | 1786 | } |
53390eff | 1787 | } |
dc3956b3 | 1788 | D( dump_sysresult(rc); ) |
9314b85a | 1789 | return (rc); |
e4976bb0 | 1790 | } |
1791 | ||
1792 | ssize_t sendto(int sk, const void *buf, size_t len, int flags, | |
1793 | const struct sockaddr *to, socklen_t tolen) | |
1794 | { | |
1795 | struct sockaddr_un sun; | |
dc3956b3 MW |
1796 | ssize_t n; |
1797 | Dpid; | |
1798 | ||
1799 | D({ char addrbuf[ADDRBUFSZ]; | |
1800 | fprintf(stderr, "noip(%d): SENDTO sk=%d, len=%lu, flags=%d, to[%d]=%s", | |
1801 | pid, sk, (unsigned long)len, flags, tolen, | |
1802 | present_sockaddr(to, tolen, addrbuf, sizeof(addrbuf))); }) | |
e4976bb0 | 1803 | |
dc3956b3 MW |
1804 | if (!to) |
1805 | D( fprintf(stderr, " -> null address; leaving"); ) | |
1806 | else if (!family_known_p(to->sa_family)) | |
1807 | D( fprintf(stderr, " -> unknown af; pass through"); ) | |
1808 | else { | |
1809 | D( fprintf(stderr, " -> checking...\n"); ) | |
e4976bb0 | 1810 | PRESERVING_ERRNO({ |
6e1fe695 | 1811 | fixup_client_socket(sk, &to, &tolen, &sun); |
e4976bb0 | 1812 | }); |
dc3956b3 | 1813 | D( fprintf(stderr, "noip(%d): SENDTO ...", pid); ) |
e4976bb0 | 1814 | } |
dc3956b3 MW |
1815 | n = real_sendto(sk, buf, len, flags, to, tolen); |
1816 | D( dump_sysresult(n); ) | |
1817 | return (n); | |
e4976bb0 | 1818 | } |
1819 | ||
1820 | ssize_t recvfrom(int sk, void *buf, size_t len, int flags, | |
1821 | struct sockaddr *from, socklen_t *fromlen) | |
1822 | { | |
1823 | char sabuf[1024]; | |
1824 | socklen_t mylen = sizeof(sabuf); | |
1825 | ssize_t n; | |
dc3956b3 | 1826 | Dpid; |
e4976bb0 | 1827 | |
dc3956b3 MW |
1828 | D( fprintf(stderr, "noip(%d): RECVFROM sk=%d, len=%lu, flags=%d", |
1829 | pid, sk, (unsigned long)len, flags); ) | |
1830 | ||
1831 | if (!from) { | |
1832 | D( fprintf(stderr, " -> null addr; pass through"); ) | |
1833 | n = real_recvfrom(sk, buf, len, flags, 0, 0); | |
1834 | } else { | |
6ec34720 MW |
1835 | n = real_recvfrom(sk, buf, len, flags, SA(sabuf), &mylen); |
1836 | if (n >= 0) { | |
1837 | D( fprintf(stderr, " -> converting...\n"); ) | |
1838 | PRESERVING_ERRNO({ | |
a62e4ece | 1839 | return_fake_peer(sk, SA(sabuf), mylen, from, fromlen); |
6ec34720 MW |
1840 | }); |
1841 | D( fprintf(stderr, "noip(%d): ... RECVFROM", pid); ) | |
1842 | } | |
dc3956b3 MW |
1843 | } |
1844 | D( dump_addrresult(n, from, fromlen ? *fromlen : 0); ) | |
e4976bb0 | 1845 | return (n); |
1846 | } | |
1847 | ||
1848 | ssize_t sendmsg(int sk, const struct msghdr *msg, int flags) | |
1849 | { | |
1850 | struct sockaddr_un sun; | |
dc3956b3 | 1851 | const struct sockaddr *sa = SA(msg->msg_name); |
e4976bb0 | 1852 | struct msghdr mymsg; |
dc3956b3 MW |
1853 | ssize_t n; |
1854 | Dpid; | |
e4976bb0 | 1855 | |
dc3956b3 MW |
1856 | D({ char addrbuf[ADDRBUFSZ]; |
1857 | fprintf(stderr, "noip(%d): SENDMSG sk=%d, " | |
1858 | "msg_flags=%d, msg_name[%d]=%s, ...", | |
1859 | pid, sk, msg->msg_flags, msg->msg_namelen, | |
1860 | present_sockaddr(sa, msg->msg_namelen, | |
1861 | addrbuf, sizeof(addrbuf))); }) | |
1862 | ||
1863 | if (!sa) | |
1864 | D( fprintf(stderr, " -> null address; leaving"); ) | |
1865 | else if (!family_known_p(sa->sa_family)) | |
1866 | D( fprintf(stderr, " -> unknown af; pass through"); ) | |
1867 | else { | |
1868 | D( fprintf(stderr, " -> checking...\n"); ) | |
e4976bb0 | 1869 | PRESERVING_ERRNO({ |
e4976bb0 | 1870 | mymsg = *msg; |
6e1fe695 | 1871 | fixup_client_socket(sk, &sa, &mymsg.msg_namelen, &sun); |
e4976bb0 | 1872 | mymsg.msg_name = SA(sa); |
1873 | msg = &mymsg; | |
1874 | }); | |
dc3956b3 | 1875 | D( fprintf(stderr, "noip(%d): SENDMSG ...", pid); ) |
e4976bb0 | 1876 | } |
dc3956b3 MW |
1877 | n = real_sendmsg(sk, msg, flags); |
1878 | D( dump_sysresult(n); ) | |
1879 | return (n); | |
e4976bb0 | 1880 | } |
1881 | ||
1882 | ssize_t recvmsg(int sk, struct msghdr *msg, int flags) | |
1883 | { | |
1884 | char sabuf[1024]; | |
dc3956b3 MW |
1885 | struct sockaddr *sa = SA(msg->msg_name); |
1886 | socklen_t len = msg->msg_namelen; | |
e4976bb0 | 1887 | ssize_t n; |
dc3956b3 | 1888 | Dpid; |
e4976bb0 | 1889 | |
dc3956b3 MW |
1890 | D( fprintf(stderr, "noip(%d): RECVMSG sk=%d msg_flags=%d, ...", |
1891 | pid, sk, msg->msg_flags); ) | |
1892 | ||
1893 | if (!msg->msg_name) { | |
1894 | D( fprintf(stderr, " -> null addr; pass through"); ) | |
9314b85a | 1895 | return (real_recvmsg(sk, msg, flags)); |
dc3956b3 | 1896 | } else { |
6ec34720 MW |
1897 | msg->msg_name = sabuf; |
1898 | msg->msg_namelen = sizeof(sabuf); | |
1899 | n = real_recvmsg(sk, msg, flags); | |
1900 | if (n >= 0) { | |
1901 | D( fprintf(stderr, " -> converting...\n"); ) | |
1902 | PRESERVING_ERRNO({ | |
a62e4ece | 1903 | return_fake_peer(sk, SA(sabuf), msg->msg_namelen, sa, &len); |
6ec34720 MW |
1904 | }); |
1905 | } | |
1906 | D( fprintf(stderr, "noip(%d): ... RECVMSG", pid); ) | |
1907 | msg->msg_name = sa; | |
1908 | msg->msg_namelen = len; | |
dc3956b3 MW |
1909 | } |
1910 | D( dump_addrresult(n, sa, len); ) | |
e4976bb0 | 1911 | return (n); |
1912 | } | |
1913 | ||
1914 | int accept(int sk, struct sockaddr *sa, socklen_t *len) | |
1915 | { | |
1916 | char sabuf[1024]; | |
1917 | socklen_t mylen = sizeof(sabuf); | |
dc3956b3 MW |
1918 | int nsk; |
1919 | Dpid; | |
e4976bb0 | 1920 | |
dc3956b3 MW |
1921 | D( fprintf(stderr, "noip(%d): ACCEPT sk=%d", pid, sk); ) |
1922 | ||
1923 | nsk = real_accept(sk, SA(sabuf), &mylen); | |
1924 | if (nsk < 0) /* failed */; | |
1925 | else if (!sa) D( fprintf(stderr, " -> address not wanted"); ) | |
1926 | else { | |
1927 | D( fprintf(stderr, " -> converting...\n"); ) | |
a62e4ece | 1928 | return_fake_peer(sk, SA(sabuf), mylen, sa, len); |
dc3956b3 MW |
1929 | D( fprintf(stderr, "noip(%d): ... ACCEPT", pid); ) |
1930 | } | |
1931 | D( dump_addrresult(nsk, sa, len ? *len : 0); ) | |
e4976bb0 | 1932 | return (nsk); |
1933 | } | |
1934 | ||
1935 | int getsockname(int sk, struct sockaddr *sa, socklen_t *len) | |
1936 | { | |
0415c10e MW |
1937 | char sabuf[1024]; |
1938 | socklen_t mylen = sizeof(sabuf); | |
dc3956b3 MW |
1939 | int rc; |
1940 | Dpid; | |
1941 | ||
1942 | D( fprintf(stderr, "noip(%d): GETSOCKNAME sk=%d", pid, sk); ) | |
0415c10e MW |
1943 | rc = real_getsockname(sk, SA(sabuf), &mylen); |
1944 | if (rc >= 0) { | |
1945 | D( fprintf(stderr, " -> converting...\n"); ) | |
a62e4ece | 1946 | return_fake_name(SA(sabuf), mylen, sa, len, 0); |
0415c10e MW |
1947 | D( fprintf(stderr, "noip(%d): ... GETSOCKNAME", pid); ) |
1948 | } | |
dc3956b3 MW |
1949 | D( dump_addrresult(rc, sa, *len); ) |
1950 | return (rc); | |
e4976bb0 | 1951 | } |
1952 | ||
1953 | int getpeername(int sk, struct sockaddr *sa, socklen_t *len) | |
1954 | { | |
0415c10e MW |
1955 | char sabuf[1024]; |
1956 | socklen_t mylen = sizeof(sabuf); | |
dc3956b3 MW |
1957 | int rc; |
1958 | Dpid; | |
1959 | ||
1960 | D( fprintf(stderr, "noip(%d): GETPEERNAME sk=%d", pid, sk); ) | |
0415c10e MW |
1961 | rc = real_getpeername(sk, SA(sabuf), &mylen); |
1962 | if (rc >= 0) { | |
1963 | D( fprintf(stderr, " -> converting...\n"); ) | |
a62e4ece | 1964 | return_fake_peer(sk, SA(sabuf), mylen, sa, len); |
0415c10e MW |
1965 | D( fprintf(stderr, "noip(%d): ... GETPEERNAME", pid); ) |
1966 | } | |
dc3956b3 | 1967 | D( dump_addrresult(rc, sa, *len); ) |
6b6af30b | 1968 | return (rc); |
e4976bb0 | 1969 | } |
1970 | ||
1971 | int getsockopt(int sk, int lev, int opt, void *p, socklen_t *len) | |
1972 | { | |
1973 | switch (lev) { | |
e32758ea | 1974 | case IPPROTO_IP: |
f47a2b17 | 1975 | case IPPROTO_IPV6: |
e32758ea MW |
1976 | case IPPROTO_TCP: |
1977 | case IPPROTO_UDP: | |
e4976bb0 | 1978 | if (*len > 0) |
1979 | memset(p, 0, *len); | |
1980 | return (0); | |
1981 | } | |
9314b85a | 1982 | return (real_getsockopt(sk, lev, opt, p, len)); |
e4976bb0 | 1983 | } |
1984 | ||
1985 | int setsockopt(int sk, int lev, int opt, const void *p, socklen_t len) | |
1986 | { | |
1987 | switch (lev) { | |
e32758ea | 1988 | case IPPROTO_IP: |
f47a2b17 | 1989 | case IPPROTO_IPV6: |
e32758ea MW |
1990 | case IPPROTO_TCP: |
1991 | case IPPROTO_UDP: | |
e4976bb0 | 1992 | return (0); |
1993 | } | |
1994 | switch (opt) { | |
1995 | case SO_BINDTODEVICE: | |
1996 | case SO_ATTACH_FILTER: | |
1997 | case SO_DETACH_FILTER: | |
1998 | return (0); | |
1999 | } | |
9314b85a | 2000 | return (real_setsockopt(sk, lev, opt, p, len)); |
e4976bb0 | 2001 | } |
2002 | ||
658c1774 MW |
2003 | int ioctl(int fd, unsigned long op, ...) |
2004 | { | |
2005 | va_list ap; | |
2006 | void *arg; | |
2007 | int sk; | |
2008 | int rc; | |
2009 | ||
2010 | va_start(ap, op); | |
2011 | arg = va_arg(ap, void *); | |
2012 | ||
2013 | switch (op) { | |
2014 | case SIOCGIFADDR: | |
2015 | case SIOCGIFBRDADDR: | |
2016 | case SIOCGIFDSTADDR: | |
2017 | case SIOCGIFNETMASK: | |
2018 | PRESERVING_ERRNO({ | |
2019 | if (fixup_real_ip_socket(fd, AF_INET, &sk)) goto real; | |
2020 | }); | |
2021 | rc = real_ioctl(sk, op, arg); | |
2022 | PRESERVING_ERRNO({ close(sk); }); | |
2023 | break; | |
2024 | default: | |
2025 | real: | |
2026 | rc = real_ioctl(fd, op, arg); | |
2027 | break; | |
2028 | } | |
2029 | va_end(ap); | |
2030 | return (rc); | |
2031 | } | |
2032 | ||
1d1ccf4f | 2033 | /*----- Initialization ----------------------------------------------------*/ |
e4976bb0 | 2034 | |
1d1ccf4f | 2035 | /* Clean up the socket directory, deleting stale sockets. */ |
e4976bb0 | 2036 | static void cleanup_sockdir(void) |
2037 | { | |
2038 | DIR *dir; | |
2039 | struct dirent *d; | |
9314b85a | 2040 | address addr; |
e4976bb0 | 2041 | struct sockaddr_un sun; |
3ef1fec9 | 2042 | struct stat st; |
e397f0bd | 2043 | Dpid; |
e4976bb0 | 2044 | |
9314b85a | 2045 | if ((dir = opendir(sockdir)) == 0) return; |
4ab301de | 2046 | sun.sun_family = AF_UNIX; |
e4976bb0 | 2047 | while ((d = readdir(dir)) != 0) { |
2048 | if (d->d_name[0] == '.') continue; | |
2049 | snprintf(sun.sun_path, sizeof(sun.sun_path), | |
2050 | "%s/%s", sockdir, d->d_name); | |
9314b85a | 2051 | if (decode_inet_addr(&addr.sa, 0, &sun, SUN_LEN(&sun)) || |
3ef1fec9 | 2052 | stat(sun.sun_path, &st) || |
4ab301de | 2053 | !S_ISSOCK(st.st_mode)) { |
e397f0bd MW |
2054 | D( fprintf(stderr, "noip(%d): ignoring unknown socketdir entry `%s'\n", |
2055 | pid, sun.sun_path); ) | |
3ef1fec9 | 2056 | continue; |
4ab301de | 2057 | } |
e4976bb0 | 2058 | if (unix_socket_status(&sun, 0) == STALE) { |
e397f0bd MW |
2059 | D( fprintf(stderr, "noip(%d): clearing away stale socket %s\n", |
2060 | pid, d->d_name); ) | |
e4976bb0 | 2061 | unlink(sun.sun_path); |
2062 | } | |
2063 | } | |
2064 | closedir(dir); | |
2065 | } | |
2066 | ||
1d1ccf4f MW |
2067 | /* Find the addresses attached to local network interfaces, and remember them |
2068 | * in a table. | |
2069 | */ | |
e4976bb0 | 2070 | static void get_local_ipaddrs(void) |
2071 | { | |
9f1396d9 | 2072 | struct ifaddrs *ifa_head, *ifa; |
9314b85a | 2073 | ipaddr a; |
e4976bb0 | 2074 | int i; |
e397f0bd | 2075 | Dpid; |
e4976bb0 | 2076 | |
e397f0bd | 2077 | D( fprintf(stderr, "noip(%d): fetching local addresses...\n", pid); ) |
9f1396d9 MW |
2078 | if (getifaddrs(&ifa_head)) { perror("getifaddrs"); return; } |
2079 | for (n_local_ipaddrs = 0, ifa = ifa_head; | |
2080 | n_local_ipaddrs < MAX_LOCAL_IPADDRS && ifa; | |
2081 | ifa = ifa->ifa_next) { | |
9314b85a | 2082 | if (!ifa->ifa_addr || !family_known_p(ifa->ifa_addr->sa_family)) |
e4976bb0 | 2083 | continue; |
9314b85a MW |
2084 | ipaddr_from_sockaddr(&a, ifa->ifa_addr); |
2085 | D({ char buf[ADDRBUFSZ]; | |
e397f0bd MW |
2086 | fprintf(stderr, "noip(%d): local addr %s = %s", pid, |
2087 | ifa->ifa_name, | |
9314b85a MW |
2088 | inet_ntop(ifa->ifa_addr->sa_family, &a, |
2089 | buf, sizeof(buf))); }) | |
9f1396d9 | 2090 | for (i = 0; i < n_local_ipaddrs; i++) { |
9314b85a MW |
2091 | if (ifa->ifa_addr->sa_family == local_ipaddrs[i].af && |
2092 | ipaddr_equal_p(local_ipaddrs[i].af, &a, &local_ipaddrs[i].addr)) { | |
9f1396d9 MW |
2093 | D( fprintf(stderr, " (duplicate)\n"); ) |
2094 | goto skip; | |
2095 | } | |
2096 | } | |
2097 | D( fprintf(stderr, "\n"); ) | |
9314b85a MW |
2098 | local_ipaddrs[n_local_ipaddrs].af = ifa->ifa_addr->sa_family; |
2099 | local_ipaddrs[n_local_ipaddrs].addr = a; | |
9f1396d9 MW |
2100 | n_local_ipaddrs++; |
2101 | skip:; | |
e4976bb0 | 2102 | } |
9f1396d9 | 2103 | freeifaddrs(ifa_head); |
e4976bb0 | 2104 | } |
2105 | ||
1d1ccf4f | 2106 | /* Print the given message to standard error. Avoids stdio. */ |
72d85cdb | 2107 | static void printerr(const char *p) |
65f3786c | 2108 | { if (write(STDERR_FILENO, p, strlen(p))) ; } |
3ef1fec9 | 2109 | |
1d1ccf4f | 2110 | /* Create the socket directory, being careful about permissions. */ |
3ef1fec9 | 2111 | static void create_sockdir(void) |
2112 | { | |
2113 | struct stat st; | |
2114 | ||
b514afdd | 2115 | if (lstat(sockdir, &st)) { |
3ef1fec9 | 2116 | if (errno == ENOENT) { |
2117 | if (mkdir(sockdir, 0700)) { | |
2118 | perror("noip: creating socketdir"); | |
2119 | exit(127); | |
2120 | } | |
b514afdd | 2121 | if (!lstat(sockdir, &st)) |
3ef1fec9 | 2122 | goto check; |
2123 | } | |
2124 | perror("noip: checking socketdir"); | |
2125 | exit(127); | |
2126 | } | |
2127 | check: | |
2128 | if (!S_ISDIR(st.st_mode)) { | |
2129 | printerr("noip: bad socketdir: not a directory\n"); | |
2130 | exit(127); | |
2131 | } | |
2132 | if (st.st_uid != uid) { | |
2133 | printerr("noip: bad socketdir: not owner\n"); | |
2134 | exit(127); | |
2135 | } | |
2136 | if (st.st_mode & 077) { | |
2137 | printerr("noip: bad socketdir: not private\n"); | |
2138 | exit(127); | |
2139 | } | |
2140 | } | |
2141 | ||
1d1ccf4f MW |
2142 | /* Initialization function. */ |
2143 | static void setup(void) __attribute__((constructor)); | |
e4976bb0 | 2144 | static void setup(void) |
2145 | { | |
2146 | PRESERVING_ERRNO({ | |
2147 | char *p; | |
2148 | ||
2149 | import(); | |
3ef1fec9 | 2150 | uid = geteuid(); |
e4976bb0 | 2151 | if ((p = getenv("NOIP_DEBUG")) && atoi(p)) |
2152 | debug = 1; | |
2153 | get_local_ipaddrs(); | |
2154 | readconfig(); | |
3ef1fec9 | 2155 | create_sockdir(); |
e4976bb0 | 2156 | cleanup_sockdir(); |
2157 | }); | |
2158 | } | |
1d1ccf4f MW |
2159 | |
2160 | /*----- That's all, folks -------------------------------------------------*/ |