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 | ||
62 | enum { UNUSED, STALE, USED }; /* Unix socket status values */ | |
63 | enum { WANT_FRESH, WANT_EXISTING }; /* Socket address dispositions */ | |
64 | enum { DENY, ALLOW }; /* ACL verdicts */ | |
65 | ||
2a06ea0b | 66 | static int address_families[] = { AF_INET, AF_INET6, -1 }; |
9314b85a MW |
67 | |
68 | #define ADDRBUFSZ 64 | |
69 | ||
70 | /* Address representations. */ | |
71 | typedef union ipaddr { | |
72 | struct in_addr v4; | |
2a06ea0b | 73 | struct in6_addr v6; |
9314b85a MW |
74 | } ipaddr; |
75 | ||
76 | /* Convenient socket address hacking. */ | |
77 | typedef union address { | |
78 | struct sockaddr sa; | |
79 | struct sockaddr_in sin; | |
2a06ea0b | 80 | struct sockaddr_in6 sin6; |
9314b85a MW |
81 | } address; |
82 | ||
1d1ccf4f | 83 | /* Access control list nodes */ |
e4976bb0 | 84 | typedef struct aclnode { |
85 | struct aclnode *next; | |
86 | int act; | |
9314b85a MW |
87 | int af; |
88 | ipaddr minaddr, maxaddr; | |
e4976bb0 | 89 | unsigned short minport, maxport; |
90 | } aclnode; | |
91 | ||
1d1ccf4f | 92 | /* Local address records */ |
9314b85a MW |
93 | typedef struct full_ipaddr { |
94 | int af; | |
95 | ipaddr addr; | |
96 | } full_ipaddr; | |
2a06ea0b | 97 | #define MAX_LOCAL_IPADDRS 64 |
9314b85a | 98 | static full_ipaddr local_ipaddrs[MAX_LOCAL_IPADDRS]; |
e4976bb0 | 99 | static int n_local_ipaddrs; |
100 | ||
1d1ccf4f | 101 | /* General configuration */ |
e4976bb0 | 102 | static uid_t uid; |
103 | static char *sockdir = 0; | |
104 | static int debug = 0; | |
f6049fdd | 105 | static unsigned minautoport = 16384, maxautoport = 65536; |
e4976bb0 | 106 | |
1d1ccf4f | 107 | /* Access control lists */ |
e4976bb0 | 108 | static aclnode *bind_real, **bind_tail = &bind_real; |
109 | static aclnode *connect_real, **connect_tail = &connect_real; | |
110 | ||
1d1ccf4f | 111 | /*----- Import the real versions of functions -----------------------------*/ |
e4976bb0 | 112 | |
1d1ccf4f | 113 | /* The list of functions to immport. */ |
e4976bb0 | 114 | #define IMPORTS(_) \ |
115 | _(socket, int, (int, int, int)) \ | |
116 | _(socketpair, int, (int, int, int, int *)) \ | |
117 | _(connect, int, (int, const struct sockaddr *, socklen_t)) \ | |
118 | _(bind, int, (int, const struct sockaddr *, socklen_t)) \ | |
119 | _(accept, int, (int, struct sockaddr *, socklen_t *)) \ | |
120 | _(getsockname, int, (int, struct sockaddr *, socklen_t *)) \ | |
121 | _(getpeername, int, (int, struct sockaddr *, socklen_t *)) \ | |
122 | _(getsockopt, int, (int, int, int, void *, socklen_t *)) \ | |
123 | _(setsockopt, int, (int, int, int, const void *, socklen_t)) \ | |
124 | _(sendto, ssize_t, (int, const void *buf, size_t, int, \ | |
125 | const struct sockaddr *to, socklen_t tolen)) \ | |
126 | _(recvfrom, ssize_t, (int, void *buf, size_t, int, \ | |
7d769c69 | 127 | struct sockaddr *from, socklen_t *fromlen)) \ |
e4976bb0 | 128 | _(sendmsg, ssize_t, (int, const struct msghdr *, int)) \ |
658c1774 MW |
129 | _(recvmsg, ssize_t, (int, struct msghdr *, int)) \ |
130 | _(ioctl, int, (int, unsigned long, ...)) | |
e4976bb0 | 131 | |
1d1ccf4f | 132 | /* Function pointers to set up. */ |
e4976bb0 | 133 | #define DECL(imp, ret, args) static ret (*real_##imp) args; |
134 | IMPORTS(DECL) | |
135 | #undef DECL | |
136 | ||
1d1ccf4f | 137 | /* Import the system calls. */ |
e4976bb0 | 138 | static void import(void) |
139 | { | |
140 | #define IMPORT(imp, ret, args) \ | |
141 | real_##imp = (ret (*)args)dlsym(RTLD_NEXT, #imp); | |
142 | IMPORTS(IMPORT) | |
143 | #undef IMPORT | |
144 | } | |
145 | ||
1d1ccf4f | 146 | /*----- Utilities ---------------------------------------------------------*/ |
e4976bb0 | 147 | |
1d1ccf4f | 148 | /* Socket address casts */ |
e4976bb0 | 149 | #define SA(sa) ((struct sockaddr *)(sa)) |
150 | #define SIN(sa) ((struct sockaddr_in *)(sa)) | |
2a06ea0b | 151 | #define SIN6(sa) ((struct sockaddr_in6 *)(sa)) |
e4976bb0 | 152 | #define SUN(sa) ((struct sockaddr_un *)(sa)) |
153 | ||
1d1ccf4f | 154 | /* Raw bytes */ |
e4976bb0 | 155 | #define UC(ch) ((unsigned char)(ch)) |
156 | ||
1d1ccf4f | 157 | /* Memory allocation */ |
e4976bb0 | 158 | #define NEW(x) ((x) = xmalloc(sizeof(*x))) |
159 | #define NEWV(x, n) ((x) = xmalloc(sizeof(*x) * (n))) | |
160 | ||
1d1ccf4f | 161 | /* Debugging */ |
e4976bb0 | 162 | #ifdef DEBUG |
163 | # define D(body) { if (debug) { body } } | |
164 | #else | |
165 | # define D(body) ; | |
166 | #endif | |
167 | ||
1d1ccf4f | 168 | /* Preservation of error status */ |
e4976bb0 | 169 | #define PRESERVING_ERRNO(body) do { \ |
170 | int _err = errno; { body } errno = _err; \ | |
171 | } while (0) | |
172 | ||
1d1ccf4f | 173 | /* Allocate N bytes of memory; abort on failure. */ |
e4976bb0 | 174 | static void *xmalloc(size_t n) |
175 | { | |
176 | void *p; | |
177 | if (!n) return (0); | |
3ef1fec9 | 178 | if ((p = malloc(n)) == 0) { perror("malloc"); exit(127); } |
e4976bb0 | 179 | return (p); |
180 | } | |
181 | ||
1d1ccf4f | 182 | /* Allocate a copy of the null-terminated string P; abort on failure. */ |
e4976bb0 | 183 | static char *xstrdup(const char *p) |
184 | { | |
185 | size_t n = strlen(p) + 1; | |
186 | char *q = xmalloc(n); | |
187 | memcpy(q, p, n); | |
188 | return (q); | |
189 | } | |
9314b85a MW |
190 | |
191 | /*----- Address-type hacking ----------------------------------------------*/ | |
192 | ||
193 | /* If M is a simple mask, i.e., consists of a sequence of zero bits followed | |
194 | * by a sequence of one bits, then return the length of the latter sequence | |
195 | * (which may be zero); otherwise return -1. | |
196 | */ | |
197 | static int simple_mask_length(unsigned long m) | |
198 | { | |
199 | int n = 0; | |
200 | ||
201 | while (m & 1) { n++; m >>= 1; } | |
202 | return (m ? -1 : n); | |
203 | } | |
204 | ||
205 | /* Answer whether AF is an interesting address family. */ | |
206 | static int family_known_p(int af) | |
207 | { | |
208 | switch (af) { | |
209 | case AF_INET: | |
2a06ea0b | 210 | case AF_INET6: |
9314b85a MW |
211 | return (1); |
212 | default: | |
213 | return (0); | |
214 | } | |
215 | } | |
216 | ||
217 | /* Return the socket address length for address family AF. */ | |
218 | static socklen_t family_socklen(int af) | |
219 | { | |
220 | switch (af) { | |
221 | case AF_INET: return (sizeof(struct sockaddr_in)); | |
2a06ea0b | 222 | case AF_INET6: return (sizeof(struct sockaddr_in6)); |
9314b85a MW |
223 | default: abort(); |
224 | } | |
225 | } | |
226 | ||
227 | /* Return the width of addresses of kind AF. */ | |
228 | static int address_width(int af) | |
229 | { | |
230 | switch (af) { | |
231 | case AF_INET: return 32; | |
2a06ea0b | 232 | case AF_INET6: return 128; |
9314b85a MW |
233 | default: abort(); |
234 | } | |
235 | } | |
236 | ||
237 | /* If addresses A and B share a common prefix then return its length; | |
238 | * otherwise return -1. | |
239 | */ | |
240 | static int common_prefix_length(int af, const ipaddr *a, const ipaddr *b) | |
241 | { | |
242 | switch (af) { | |
243 | case AF_INET: { | |
244 | unsigned long aa = ntohl(a->v4.s_addr), bb = ntohl(b->v4.s_addr); | |
245 | unsigned long m = aa^bb; | |
246 | if ((aa&m) == 0 && (bb&m) == m) return (32 - simple_mask_length(m)); | |
247 | else return (-1); | |
248 | } break; | |
2a06ea0b MW |
249 | case AF_INET6: { |
250 | const uint8_t *aa = a->v6.s6_addr, *bb = b->v6.s6_addr; | |
251 | unsigned m; | |
252 | unsigned n; | |
253 | int i; | |
254 | ||
255 | for (i = 0; i < 16 && aa[i] == bb[i]; i++); | |
256 | n = 8*i; | |
257 | if (i < 16) { | |
258 | m = aa[i]^bb[i]; | |
259 | if ((aa[i]&m) != 0 || (bb[i]&m) != m) return (-1); | |
260 | n += 8 - simple_mask_length(m); | |
261 | for (i++; i < 16; i++) | |
262 | if (aa[i] || bb[i] != 0xff) return (-1); | |
263 | } | |
264 | return (n); | |
265 | } break; | |
9314b85a MW |
266 | default: |
267 | abort(); | |
268 | } | |
269 | } | |
270 | ||
271 | /* Extract the port number (in host byte-order) from SA. */ | |
272 | static int port_from_sockaddr(const struct sockaddr *sa) | |
273 | { | |
274 | switch (sa->sa_family) { | |
275 | case AF_INET: return (ntohs(SIN(sa)->sin_port)); | |
2a06ea0b | 276 | case AF_INET6: return (ntohs(SIN6(sa)->sin6_port)); |
9314b85a MW |
277 | default: abort(); |
278 | } | |
279 | } | |
280 | ||
281 | /* Store the port number PORT (in host byte-order) in SA. */ | |
282 | static void port_to_sockaddr(struct sockaddr *sa, int port) | |
283 | { | |
284 | switch (sa->sa_family) { | |
285 | case AF_INET: SIN(sa)->sin_port = htons(port); break; | |
2a06ea0b | 286 | case AF_INET6: SIN6(sa)->sin6_port = htons(port); break; |
9314b85a MW |
287 | default: abort(); |
288 | } | |
289 | } | |
10cee633 | 290 | |
9314b85a MW |
291 | /* Extract the address part from SA and store it in A. */ |
292 | static void ipaddr_from_sockaddr(ipaddr *a, const struct sockaddr *sa) | |
293 | { | |
294 | switch (sa->sa_family) { | |
295 | case AF_INET: a->v4 = SIN(sa)->sin_addr; break; | |
2a06ea0b | 296 | case AF_INET6: a->v6 = SIN6(sa)->sin6_addr; break; |
9314b85a MW |
297 | default: abort(); |
298 | } | |
299 | } | |
300 | ||
301 | /* Copy a whole socket address about. */ | |
302 | static void copy_sockaddr(struct sockaddr *sa_dst, | |
303 | const struct sockaddr *sa_src) | |
304 | { memcpy(sa_dst, sa_src, family_socklen(sa_src->sa_family)); } | |
305 | ||
306 | /* Answer whether two addresses are equal. */ | |
307 | static int ipaddr_equal_p(int af, const ipaddr *a, const ipaddr *b) | |
308 | { | |
309 | switch (af) { | |
310 | case AF_INET: return (a->v4.s_addr == b->v4.s_addr); | |
2a06ea0b | 311 | case AF_INET6: return (memcmp(a->v6.s6_addr, b->v6.s6_addr, 16) == 0); |
9314b85a MW |
312 | default: abort(); |
313 | } | |
314 | } | |
315 | ||
316 | /* Answer whether the address part of SA is between A and B (inclusive). We | |
317 | * assume that SA has the correct address family. | |
318 | */ | |
319 | static int sockaddr_in_range_p(const struct sockaddr *sa, | |
320 | const ipaddr *a, const ipaddr *b) | |
321 | { | |
322 | switch (sa->sa_family) { | |
323 | case AF_INET: { | |
324 | unsigned long addr = ntohl(SIN(sa)->sin_addr.s_addr); | |
325 | return (ntohl(a->v4.s_addr) <= addr && | |
326 | addr <= ntohl(b->v4.s_addr)); | |
327 | } break; | |
2a06ea0b MW |
328 | case AF_INET6: { |
329 | const uint8_t *ss = SIN6(sa)->sin6_addr.s6_addr; | |
330 | const uint8_t *aa = a->v6.s6_addr, *bb = b->v6.s6_addr; | |
331 | int h = 1, l = 1; | |
332 | int i; | |
333 | ||
334 | for (i = 0; h && l && i < 16; i++, ss++, aa++, bb++) { | |
335 | if (*ss < *aa || *bb < *ss) return (0); | |
336 | if (*aa < *ss) l = 0; | |
337 | if (*ss < *bb) h = 0; | |
338 | } | |
339 | return (1); | |
340 | } break; | |
9314b85a MW |
341 | default: |
342 | abort(); | |
343 | } | |
344 | } | |
345 | ||
346 | /* Fill in SA with the appropriate wildcard address. */ | |
347 | static void wildcard_address(int af, struct sockaddr *sa) | |
348 | { | |
349 | switch (af) { | |
350 | case AF_INET: { | |
351 | struct sockaddr_in *sin = SIN(sa); | |
352 | memset(sin, 0, sizeof(*sin)); | |
353 | sin->sin_family = AF_INET; | |
354 | sin->sin_port = 0; | |
355 | sin->sin_addr.s_addr = INADDR_ANY; | |
356 | } break; | |
2a06ea0b MW |
357 | case AF_INET6: { |
358 | struct sockaddr_in6 *sin6 = SIN6(sa); | |
dc2b0a44 | 359 | memset(sin6, 0, sizeof(*sin6)); |
2a06ea0b MW |
360 | sin6->sin6_family = AF_INET6; |
361 | sin6->sin6_port = 0; | |
362 | sin6->sin6_addr = in6addr_any; | |
363 | sin6->sin6_scope_id = 0; | |
364 | sin6->sin6_flowinfo = 0; | |
365 | } break; | |
9314b85a MW |
366 | default: |
367 | abort(); | |
368 | } | |
369 | } | |
370 | ||
371 | /* Mask the address A, forcing all but the top PLEN bits to zero or one | |
372 | * according to HIGHP. | |
373 | */ | |
374 | static void mask_address(int af, ipaddr *a, int plen, int highp) | |
375 | { | |
376 | switch (af) { | |
377 | case AF_INET: { | |
378 | unsigned long addr = ntohl(a->v4.s_addr); | |
379 | unsigned long mask = plen ? ~0ul << (32 - plen) : 0; | |
380 | addr &= mask; | |
381 | if (highp) addr |= ~mask; | |
382 | a->v4.s_addr = htonl(addr & 0xffffffff); | |
383 | } break; | |
2a06ea0b MW |
384 | case AF_INET6: { |
385 | int i = plen/8; | |
386 | unsigned m = (0xff << (8 - plen%8)) & 0xff; | |
387 | unsigned s = highp ? 0xff : 0; | |
388 | if (m) { | |
389 | a->v6.s6_addr[i] = (a->v6.s6_addr[i] & m) | (s & ~m); | |
390 | i++; | |
391 | } | |
392 | for (; i < 16; i++) a->v6.s6_addr[i] = s; | |
393 | } break; | |
9314b85a MW |
394 | default: |
395 | abort(); | |
396 | } | |
397 | } | |
398 | ||
399 | /* Write a presentation form of SA to BUF, a buffer of length SZ. LEN is the | |
400 | * address length; if it's zero, look it up based on the address family. | |
401 | * Return a pointer to the string (which might, in an emergency, be a static | |
402 | * string rather than your buffer). | |
403 | */ | |
404 | static char *present_sockaddr(const struct sockaddr *sa, socklen_t len, | |
405 | char *buf, size_t sz) | |
406 | { | |
407 | #define WANT(n_) do { if (sz < (n_)) goto nospace; } while (0) | |
408 | #define PUTC(c_) do { *buf++ = (c_); sz--; } while (0) | |
409 | ||
410 | if (!sz) return "<no-space-in-buffer>"; | |
411 | if (!len) len = family_socklen(sa->sa_family); | |
412 | ||
413 | switch (sa->sa_family) { | |
414 | case AF_UNIX: { | |
415 | struct sockaddr_un *sun = SUN(sa); | |
416 | char *p = sun->sun_path; | |
417 | size_t n = len - offsetof(struct sockaddr_un, sun_path); | |
418 | ||
419 | assert(n); | |
420 | if (*p == 0) { | |
421 | WANT(1); PUTC('@'); | |
422 | p++; n--; | |
423 | while (n) { | |
424 | switch (*p) { | |
425 | case 0: WANT(2); PUTC('\\'); PUTC('0'); break; | |
426 | case '\a': WANT(2); PUTC('\\'); PUTC('a'); break; | |
427 | case '\n': WANT(2); PUTC('\\'); PUTC('n'); break; | |
428 | case '\r': WANT(2); PUTC('\\'); PUTC('r'); break; | |
429 | case '\t': WANT(2); PUTC('\\'); PUTC('t'); break; | |
430 | case '\v': WANT(2); PUTC('\\'); PUTC('v'); break; | |
431 | case '\\': WANT(2); PUTC('\\'); PUTC('\\'); break; | |
432 | default: | |
433 | if (*p > ' ' && *p <= '~') | |
434 | { WANT(1); PUTC(*p); } | |
435 | else { | |
436 | WANT(4); PUTC('\\'); PUTC('x'); | |
437 | PUTC((*p >> 4)&0xf); PUTC((*p >> 0)&0xf); | |
438 | } | |
439 | break; | |
440 | } | |
441 | p++; n--; | |
442 | } | |
443 | } else { | |
444 | if (*p != '/') { WANT(2); PUTC('.'); PUTC('/'); } | |
445 | while (n && *p) { WANT(1); PUTC(*p); p++; n--; } | |
446 | } | |
447 | WANT(1); PUTC(0); | |
448 | } break; | |
2a06ea0b | 449 | case AF_INET: case AF_INET6: { |
9314b85a MW |
450 | char addrbuf[NI_MAXHOST], portbuf[NI_MAXSERV]; |
451 | int err = getnameinfo(sa, len, | |
452 | addrbuf, sizeof(addrbuf), | |
453 | portbuf, sizeof(portbuf), | |
454 | NI_NUMERICHOST | NI_NUMERICSERV); | |
455 | assert(!err); | |
456 | snprintf(buf, sz, strchr(addrbuf, ':') ? "[%s]:%s" : "%s:%s", | |
457 | addrbuf, portbuf); | |
458 | } break; | |
459 | default: | |
460 | snprintf(buf, sz, "<unknown-address-family %d>", sa->sa_family); | |
461 | break; | |
462 | } | |
463 | return (buf); | |
464 | ||
465 | nospace: | |
466 | buf[sz - 1] = 0; | |
467 | return (buf); | |
468 | } | |
469 | ||
470 | /* Guess the family of a textual socket address. */ | |
471 | static int guess_address_family(const char *p) | |
2a06ea0b | 472 | { return (strchr(p, ':') ? AF_INET6 : AF_INET); } |
9314b85a MW |
473 | |
474 | /* Parse a socket address P and write the result to SA. */ | |
475 | static int parse_sockaddr(struct sockaddr *sa, const char *p) | |
476 | { | |
477 | char buf[ADDRBUFSZ]; | |
478 | char *q; | |
479 | struct addrinfo *ai, ai_hint = { 0 }; | |
480 | ||
481 | if (strlen(p) >= sizeof(buf) - 1) return (-1); | |
482 | strcpy(buf, p); p = buf; | |
483 | if (*p != '[') { | |
484 | if ((q = strchr(p, ':')) == 0) return (-1); | |
485 | *q++ = 0; | |
486 | } else { | |
487 | p++; | |
488 | if ((q = strchr(p, ']')) == 0) return (-1); | |
489 | *q++ = 0; | |
490 | if (*q != ':') return (-1); | |
491 | q++; | |
492 | } | |
493 | ||
494 | ai_hint.ai_family = AF_UNSPEC; | |
495 | ai_hint.ai_socktype = SOCK_DGRAM; | |
496 | ai_hint.ai_flags = AI_NUMERICHOST | AI_NUMERICSERV; | |
497 | if (getaddrinfo(p, q, &ai_hint, &ai)) return (-1); | |
498 | memcpy(sa, ai->ai_addr, ai->ai_addrlen); | |
499 | freeaddrinfo(ai); | |
500 | return (0); | |
501 | } | |
502 | ||
1d1ccf4f | 503 | /*----- Access control lists ----------------------------------------------*/ |
e4976bb0 | 504 | |
505 | #ifdef DEBUG | |
506 | ||
1d1ccf4f | 507 | /* Write to standard error a description of the ACL node A. */ |
bb182ccf | 508 | static void dump_aclnode(const aclnode *a) |
e4976bb0 | 509 | { |
9314b85a MW |
510 | char buf[ADDRBUFSZ]; |
511 | const char *p; | |
512 | int plen; | |
e4976bb0 | 513 | |
e4976bb0 | 514 | fprintf(stderr, "noip: %c ", a->act ? '+' : '-'); |
9314b85a MW |
515 | plen = common_prefix_length(a->af, &a->minaddr, &a->maxaddr); |
516 | p = inet_ntop(a->af, &a->minaddr, buf, sizeof(buf)); | |
517 | fprintf(stderr, strchr(p, ':') ? "[%s]" : "%s", p); | |
518 | if (plen < 0) { | |
519 | p = inet_ntop(a->af, &a->maxaddr, buf, sizeof(buf)); | |
520 | fprintf(stderr, strchr(p, ':') ? "-[%s]" : "-%s", p); | |
521 | } else if (plen < address_width(a->af)) | |
522 | fprintf(stderr, "/%d", plen); | |
e4976bb0 | 523 | if (a->minport != 0 || a->maxport != 0xffff) { |
524 | fprintf(stderr, ":%u", (unsigned)a->minport); | |
525 | if (a->minport != a->maxport) | |
526 | fprintf(stderr, "-%u", (unsigned)a->maxport); | |
527 | } | |
528 | fputc('\n', stderr); | |
529 | } | |
530 | ||
bb182ccf | 531 | static void dump_acl(const aclnode *a) |
1d1ccf4f MW |
532 | { |
533 | int act = ALLOW; | |
534 | ||
535 | for (; a; a = a->next) { | |
536 | dump_aclnode(a); | |
537 | act = a->act; | |
538 | } | |
539 | fprintf(stderr, "noip: [default policy: %s]\n", | |
540 | act == ALLOW ? "DENY" : "ALLOW"); | |
541 | } | |
542 | ||
e4976bb0 | 543 | #endif |
544 | ||
9314b85a | 545 | /* Returns nonzero if the ACL A allows the socket address SA. */ |
bb182ccf | 546 | static int acl_allows_p(const aclnode *a, const struct sockaddr *sa) |
e4976bb0 | 547 | { |
9314b85a | 548 | unsigned short port = port_from_sockaddr(sa); |
e4976bb0 | 549 | int act = ALLOW; |
550 | ||
9314b85a MW |
551 | D({ char buf[ADDRBUFSZ]; |
552 | fprintf(stderr, "noip: check %s\n", | |
553 | present_sockaddr(sa, 0, buf, sizeof(buf))); }) | |
e4976bb0 | 554 | for (; a; a = a->next) { |
555 | D( dump_aclnode(a); ) | |
9314b85a | 556 | if (sockaddr_in_range_p(sa, &a->minaddr, &a->maxaddr) && |
e4976bb0 | 557 | a->minport <= port && port <= a->maxport) { |
558 | D( fprintf(stderr, "noip: aha! %s\n", a->act ? "ALLOW" : "DENY"); ) | |
559 | return (a->act); | |
560 | } | |
561 | act = a->act; | |
562 | } | |
563 | D( fprintf(stderr, "noip: nothing found: %s\n", act ? "DENY" : "ALLOW"); ) | |
564 | return (!act); | |
565 | } | |
566 | ||
1d1ccf4f | 567 | /*----- Socket address conversion -----------------------------------------*/ |
e4976bb0 | 568 | |
1d1ccf4f | 569 | /* Return a uniformly distributed integer between MIN and MAX inclusive. */ |
f6049fdd | 570 | static unsigned randrange(unsigned min, unsigned max) |
571 | { | |
572 | unsigned mask, i; | |
573 | ||
574 | /* It's so nice not to have to care about the quality of the generator | |
9314b85a MW |
575 | * much! |
576 | */ | |
f6049fdd | 577 | max -= min; |
578 | for (mask = 1; mask < max; mask = (mask << 1) | 1) | |
579 | ; | |
580 | do i = rand() & mask; while (i > max); | |
581 | return (i + min); | |
582 | } | |
583 | ||
1d1ccf4f MW |
584 | /* Return the status of Unix-domain socket address SUN. Returns: UNUSED if |
585 | * the socket doesn't exist; USED if the path refers to an active socket, or | |
586 | * isn't really a socket at all, or we can't tell without a careful search | |
587 | * and QUICKP is set; or STALE if the file refers to a socket which isn't | |
588 | * being used any more. | |
589 | */ | |
590 | static int unix_socket_status(struct sockaddr_un *sun, int quickp) | |
591 | { | |
592 | struct stat st; | |
593 | FILE *fp = 0; | |
594 | size_t len, n; | |
595 | int rc; | |
596 | char buf[256]; | |
597 | ||
598 | if (stat(sun->sun_path, &st)) | |
599 | return (errno == ENOENT ? UNUSED : USED); | |
600 | if (!S_ISSOCK(st.st_mode) || quickp) | |
601 | return (USED); | |
602 | rc = USED; | |
603 | if ((fp = fopen("/proc/net/unix", "r")) == 0) | |
604 | goto done; | |
72d85cdb | 605 | if (!fgets(buf, sizeof(buf), fp)) goto done; /* skip header */ |
1d1ccf4f MW |
606 | len = strlen(sun->sun_path); |
607 | while (fgets(buf, sizeof(buf), fp)) { | |
608 | n = strlen(buf); | |
609 | if (n >= len + 2 && buf[n - len - 2] == ' ' && buf[n - 1] == '\n' && | |
610 | memcmp(buf + n - len - 1, sun->sun_path, len) == 0) | |
611 | goto done; | |
612 | } | |
613 | if (ferror(fp)) | |
614 | goto done; | |
615 | rc = STALE; | |
616 | done: | |
617 | if (fp) fclose(fp); | |
618 | return (rc); | |
619 | } | |
620 | ||
9314b85a MW |
621 | /* Encode the Internet address SA as a Unix-domain address SUN. If WANT is |
622 | * WANT_FRESH, and SA's port number is zero, then we pick an arbitrary local | |
1d1ccf4f | 623 | * port. Otherwise we pick the port given. There's an unpleasant hack to |
9314b85a MW |
624 | * find servers bound to local wildcard addresses. Returns zero on success; |
625 | * -1 on failure. | |
1d1ccf4f | 626 | */ |
e4976bb0 | 627 | static int encode_inet_addr(struct sockaddr_un *sun, |
9314b85a | 628 | const struct sockaddr *sa, |
e4976bb0 | 629 | int want) |
630 | { | |
631 | int i; | |
3ef1fec9 | 632 | int desperatep = 0; |
9314b85a MW |
633 | address addr; |
634 | char buf[ADDRBUFSZ]; | |
e4976bb0 | 635 | int rc; |
636 | ||
9314b85a MW |
637 | D( fprintf(stderr, "noip: encode %s (%s)", |
638 | present_sockaddr(sa, 0, buf, sizeof(buf)), | |
e4976bb0 | 639 | want == WANT_EXISTING ? "EXISTING" : "FRESH"); ) |
640 | sun->sun_family = AF_UNIX; | |
9314b85a MW |
641 | if (port_from_sockaddr(sa) || want == WANT_EXISTING) { |
642 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir, | |
643 | present_sockaddr(sa, 0, buf, sizeof(buf))); | |
e4976bb0 | 644 | rc = unix_socket_status(sun, 0); |
645 | if (rc == STALE) unlink(sun->sun_path); | |
646 | if (rc != USED && want == WANT_EXISTING) { | |
9314b85a MW |
647 | wildcard_address(sa->sa_family, &addr.sa); |
648 | port_to_sockaddr(&addr.sa, port_from_sockaddr(sa)); | |
649 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir, | |
650 | present_sockaddr(&addr.sa, 0, buf, sizeof(buf))); | |
e4976bb0 | 651 | if (unix_socket_status(sun, 0) == STALE) unlink(sun->sun_path); |
652 | } | |
653 | } else { | |
9314b85a | 654 | copy_sockaddr(&addr.sa, sa); |
f6049fdd | 655 | for (i = 0; i < 10; i++) { |
9314b85a MW |
656 | port_to_sockaddr(&addr.sa, randrange(minautoport, maxautoport)); |
657 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir, | |
658 | present_sockaddr(&addr.sa, 0, buf, sizeof(buf))); | |
f6049fdd | 659 | if (unix_socket_status(sun, 1) == UNUSED) goto found; |
660 | } | |
3ef1fec9 | 661 | for (desperatep = 0; desperatep < 2; desperatep++) { |
f6049fdd | 662 | for (i = minautoport; i <= maxautoport; i++) { |
9314b85a MW |
663 | port_to_sockaddr(&addr.sa, i); |
664 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir, | |
665 | present_sockaddr(&addr.sa, 0, buf, sizeof(buf))); | |
3ef1fec9 | 666 | rc = unix_socket_status(sun, !desperatep); |
e4976bb0 | 667 | switch (rc) { |
668 | case STALE: unlink(sun->sun_path); | |
669 | case UNUSED: goto found; | |
670 | } | |
671 | } | |
672 | } | |
673 | errno = EADDRINUSE; | |
674 | D( fprintf(stderr, " -- can't resolve\n"); ) | |
675 | return (-1); | |
676 | found:; | |
677 | } | |
678 | D( fprintf(stderr, " -> `%s'\n", sun->sun_path); ) | |
679 | return (0); | |
680 | } | |
681 | ||
9314b85a | 682 | /* Decode the Unix address SUN to an Internet address SIN. If AF_HINT is |
c0876c8c MW |
683 | * nonzero, an empty address (indicative of an unbound Unix-domain socket) is |
684 | * translated to a wildcard Internet address of the appropriate family. | |
685 | * Returns zero on success; -1 on failure (e.g., it wasn't one of our | |
686 | * addresses). | |
00a98a8a | 687 | */ |
9314b85a | 688 | static int decode_inet_addr(struct sockaddr *sa, int af_hint, |
e4976bb0 | 689 | const struct sockaddr_un *sun, |
9314b85a | 690 | socklen_t len) |
e4976bb0 | 691 | { |
9314b85a | 692 | char buf[ADDRBUFSZ]; |
a2114371 | 693 | size_t n = strlen(sockdir), nn; |
9314b85a | 694 | address addr; |
e4976bb0 | 695 | |
9314b85a MW |
696 | if (!sa) sa = &addr.sa; |
697 | if (sun->sun_family != AF_UNIX) return (-1); | |
698 | if (len > sizeof(*sun)) return (-1); | |
699 | ((char *)sun)[len] = 0; | |
a2114371 | 700 | nn = strlen(sun->sun_path); |
9314b85a MW |
701 | D( fprintf(stderr, "noip: decode `%s'", sun->sun_path); ) |
702 | if (af_hint && !sun->sun_path[0]) { | |
703 | wildcard_address(af_hint, sa); | |
e4976bb0 | 704 | D( fprintf(stderr, " -- unbound socket\n"); ) |
705 | return (0); | |
706 | } | |
707 | if (nn < n + 1 || nn - n >= sizeof(buf) || sun->sun_path[n] != '/' || | |
708 | memcmp(sun->sun_path, sockdir, n) != 0) { | |
709 | D( fprintf(stderr, " -- not one of ours\n"); ) | |
710 | return (-1); | |
711 | } | |
9314b85a MW |
712 | if (parse_sockaddr(sa, sun->sun_path + n + 1)) return (-1); |
713 | D( fprintf(stderr, " -> %s\n", | |
714 | present_sockaddr(sa, 0, buf, sizeof(buf))); ) | |
e4976bb0 | 715 | return (0); |
716 | } | |
717 | ||
1d1ccf4f MW |
718 | /* SK is (or at least might be) a Unix-domain socket we created when an |
719 | * Internet socket was asked for. We've decided it should be an Internet | |
86134bfe MW |
720 | * socket after all, with family AF_HINT, so convert it. If TMP is not null, |
721 | * then don't replace the existing descriptor: store the new socket in *TMP | |
722 | * and return zero. | |
1d1ccf4f | 723 | */ |
86134bfe | 724 | static int fixup_real_ip_socket(int sk, int af_hint, int *tmp) |
e4976bb0 | 725 | { |
726 | int nsk; | |
727 | int type; | |
728 | int f, fd; | |
729 | struct sockaddr_un sun; | |
9314b85a | 730 | address addr; |
e4976bb0 | 731 | socklen_t len; |
732 | ||
733 | #define OPTS(_) \ | |
734 | _(DEBUG, int) \ | |
735 | _(REUSEADDR, int) \ | |
736 | _(DONTROUTE, int) \ | |
737 | _(BROADCAST, int) \ | |
738 | _(SNDBUF, int) \ | |
739 | _(RCVBUF, int) \ | |
740 | _(OOBINLINE, int) \ | |
741 | _(NO_CHECK, int) \ | |
742 | _(LINGER, struct linger) \ | |
743 | _(BSDCOMPAT, int) \ | |
744 | _(RCVLOWAT, int) \ | |
745 | _(RCVTIMEO, struct timeval) \ | |
746 | _(SNDTIMEO, struct timeval) | |
747 | ||
748 | len = sizeof(sun); | |
749 | if (real_getsockname(sk, SA(&sun), &len)) | |
750 | return (-1); | |
9314b85a | 751 | if (decode_inet_addr(&addr.sa, af_hint, &sun, len)) |
e4976bb0 | 752 | return (0); /* Not one of ours */ |
753 | len = sizeof(type); | |
754 | if (real_getsockopt(sk, SOL_SOCKET, SO_TYPE, &type, &len) < 0 || | |
9314b85a | 755 | (nsk = real_socket(addr.sa.sa_family, type, 0)) < 0) |
e4976bb0 | 756 | return (-1); |
757 | #define FIX(opt, ty) do { \ | |
758 | ty ov_; \ | |
759 | len = sizeof(ov_); \ | |
760 | if (real_getsockopt(sk, SOL_SOCKET, SO_##opt, &ov_, &len) < 0 || \ | |
761 | real_setsockopt(nsk, SOL_SOCKET, SO_##opt, &ov_, len)) { \ | |
9fb8e5c9 | 762 | close(nsk); \ |
e4976bb0 | 763 | return (-1); \ |
764 | } \ | |
765 | } while (0); | |
766 | OPTS(FIX) | |
767 | #undef FIX | |
86134bfe MW |
768 | if (tmp) |
769 | *tmp = nsk; | |
770 | else { | |
771 | if ((f = fcntl(sk, F_GETFL)) < 0 || | |
772 | (fd = fcntl(sk, F_GETFD)) < 0 || | |
773 | fcntl(nsk, F_SETFL, f) < 0 || | |
774 | dup2(nsk, sk) < 0) { | |
775 | close(nsk); | |
776 | return (-1); | |
777 | } | |
778 | unlink(sun.sun_path); | |
9fb8e5c9 | 779 | close(nsk); |
86134bfe MW |
780 | if (fcntl(sk, F_SETFD, fd) < 0) { |
781 | perror("noip: fixup_real_ip_socket F_SETFD"); | |
782 | abort(); | |
783 | } | |
e4976bb0 | 784 | } |
785 | return (0); | |
786 | } | |
787 | ||
1d1ccf4f | 788 | /* The socket SK is about to be used to communicate with the remote address |
9314b85a MW |
789 | * SA. Assign it a local address so that getpeername(2) does something |
790 | * useful. | |
1d1ccf4f | 791 | */ |
e4976bb0 | 792 | static int do_implicit_bind(int sk, const struct sockaddr **sa, |
793 | socklen_t *len, struct sockaddr_un *sun) | |
794 | { | |
9314b85a | 795 | address addr; |
e4976bb0 | 796 | socklen_t mylen = sizeof(*sun); |
797 | ||
9314b85a | 798 | if (acl_allows_p(connect_real, *sa)) { |
86134bfe | 799 | if (fixup_real_ip_socket(sk, (*sa)->sa_family, 0)) return (-1); |
e4976bb0 | 800 | } else { |
9314b85a | 801 | if (real_getsockname(sk, SA(sun), &mylen) < 0) return (-1); |
e4976bb0 | 802 | if (sun->sun_family == AF_UNIX) { |
803 | if (mylen < sizeof(*sun)) ((char *)sun)[mylen] = 0; | |
804 | if (!sun->sun_path[0]) { | |
9314b85a MW |
805 | wildcard_address((*sa)->sa_family, &addr.sa); |
806 | encode_inet_addr(sun, &addr.sa, WANT_FRESH); | |
807 | if (real_bind(sk, SA(sun), SUN_LEN(sun))) return (-1); | |
e4976bb0 | 808 | } |
9314b85a | 809 | encode_inet_addr(sun, *sa, WANT_EXISTING); |
e4976bb0 | 810 | *sa = SA(sun); |
811 | *len = SUN_LEN(sun); | |
812 | } | |
813 | } | |
814 | return (0); | |
815 | } | |
816 | ||
1d1ccf4f MW |
817 | /* We found the real address SA, with length LEN; if it's a Unix-domain |
818 | * address corresponding to a fake socket, convert it to cover up the | |
819 | * deception. Whatever happens, put the result at FAKE and store its length | |
820 | * at FAKELEN. | |
821 | */ | |
e4976bb0 | 822 | static void return_fake_name(struct sockaddr *sa, socklen_t len, |
823 | struct sockaddr *fake, socklen_t *fakelen) | |
824 | { | |
9314b85a | 825 | address addr; |
e4976bb0 | 826 | socklen_t alen; |
827 | ||
00a98a8a | 828 | if (sa->sa_family == AF_UNIX && |
9314b85a MW |
829 | !decode_inet_addr(&addr.sa, 0, SUN(sa), len)) { |
830 | sa = &addr.sa; | |
831 | len = family_socklen(addr.sa.sa_family); | |
e4976bb0 | 832 | } |
833 | alen = len; | |
9314b85a MW |
834 | if (len > *fakelen) len = *fakelen; |
835 | if (len > 0) memcpy(fake, sa, len); | |
e4976bb0 | 836 | *fakelen = alen; |
837 | } | |
838 | ||
1d1ccf4f | 839 | /*----- Configuration -----------------------------------------------------*/ |
e4976bb0 | 840 | |
1d1ccf4f | 841 | /* Return the process owner's home directory. */ |
e4976bb0 | 842 | static char *home(void) |
843 | { | |
844 | char *p; | |
845 | struct passwd *pw; | |
846 | ||
3ef1fec9 | 847 | if (getuid() == uid && |
848 | (p = getenv("HOME")) != 0) | |
849 | return (p); | |
850 | else if ((pw = getpwuid(uid)) != 0) | |
851 | return (pw->pw_dir); | |
852 | else | |
853 | return "/notexist"; | |
e4976bb0 | 854 | } |
855 | ||
1d1ccf4f | 856 | /* Return a good temporary directory to use. */ |
e4976bb0 | 857 | static char *tmpdir(void) |
858 | { | |
859 | char *p; | |
860 | ||
861 | if ((p = getenv("TMPDIR")) != 0) return (p); | |
862 | else if ((p = getenv("TMP")) != 0) return (p); | |
863 | else return ("/tmp"); | |
864 | } | |
865 | ||
1d1ccf4f | 866 | /* Return the user's name, or at least something distinctive. */ |
e4976bb0 | 867 | static char *user(void) |
868 | { | |
869 | static char buf[16]; | |
870 | char *p; | |
871 | struct passwd *pw; | |
872 | ||
873 | if ((p = getenv("USER")) != 0) return (p); | |
874 | else if ((p = getenv("LOGNAME")) != 0) return (p); | |
875 | else if ((pw = getpwuid(uid)) != 0) return (pw->pw_name); | |
876 | else { | |
877 | snprintf(buf, sizeof(buf), "uid-%lu", (unsigned long)uid); | |
878 | return (buf); | |
879 | } | |
880 | } | |
881 | ||
1d1ccf4f | 882 | /* Skip P over space characters. */ |
e4976bb0 | 883 | #define SKIPSPC do { while (*p && isspace(UC(*p))) p++; } while (0) |
1d1ccf4f MW |
884 | |
885 | /* Set Q to point to the next word following P, null-terminate it, and step P | |
886 | * past it. */ | |
e4976bb0 | 887 | #define NEXTWORD(q) do { \ |
888 | SKIPSPC; \ | |
889 | q = p; \ | |
890 | while (*p && !isspace(UC(*p))) p++; \ | |
891 | if (*p) *p++ = 0; \ | |
892 | } while (0) | |
1d1ccf4f MW |
893 | |
894 | /* Set Q to point to the next dotted-quad address, store the ending delimiter | |
895 | * in DEL, null-terminate it, and step P past it. */ | |
9314b85a MW |
896 | static void parse_nextaddr(char **pp, char **qq, int *del) |
897 | { | |
898 | char *p = *pp; | |
899 | ||
900 | SKIPSPC; | |
901 | if (*p == '[') { | |
902 | p++; SKIPSPC; | |
903 | *qq = p; | |
904 | p += strcspn(p, "]"); | |
905 | if (*p) *p++ = 0; | |
906 | *del = 0; | |
907 | } else { | |
908 | *qq = p; | |
909 | while (*p && (*p == '.' || isdigit(UC(*p)))) p++; | |
910 | *del = *p; | |
911 | if (*p) *p++ = 0; | |
912 | } | |
913 | *pp = p; | |
914 | } | |
1d1ccf4f MW |
915 | |
916 | /* Set Q to point to the next decimal number, store the ending delimiter in | |
917 | * DEL, null-terminate it, and step P past it. */ | |
e4976bb0 | 918 | #define NEXTNUMBER(q, del) do { \ |
919 | SKIPSPC; \ | |
920 | q = p; \ | |
921 | while (*p && isdigit(UC(*p))) p++; \ | |
922 | del = *p; \ | |
923 | if (*p) *p++ = 0; \ | |
924 | } while (0) | |
1d1ccf4f MW |
925 | |
926 | /* Push the character DEL back so we scan it again, unless it's zero | |
927 | * (end-of-file). */ | |
e4976bb0 | 928 | #define RESCAN(del) do { if (del) *--p = del; } while (0) |
1d1ccf4f MW |
929 | |
930 | /* Evaluate true if P is pointing to the word KW (and not some longer string | |
931 | * of which KW is a prefix). */ | |
932 | ||
e4976bb0 | 933 | #define KWMATCHP(kw) (strncmp(p, kw, sizeof(kw) - 1) == 0 && \ |
934 | !isalnum(UC(p[sizeof(kw) - 1])) && \ | |
935 | (p += sizeof(kw) - 1)) | |
9f82ba1f | 936 | |
1d1ccf4f MW |
937 | /* Parse a port list, starting at *PP. Port lists have the form |
938 | * [:LOW[-HIGH]]: if omitted, all ports are included; if HIGH is omitted, | |
939 | * it's as if HIGH = LOW. Store LOW in *MIN, HIGH in *MAX and set *PP to the | |
940 | * rest of the string. | |
941 | */ | |
e4976bb0 | 942 | static void parse_ports(char **pp, unsigned short *min, unsigned short *max) |
943 | { | |
944 | char *p = *pp, *q; | |
945 | int del; | |
946 | ||
947 | SKIPSPC; | |
f6049fdd | 948 | if (*p != ':') |
949 | { *min = 0; *max = 0xffff; } | |
950 | else { | |
e4976bb0 | 951 | p++; |
f6049fdd | 952 | NEXTNUMBER(q, del); *min = strtoul(q, 0, 0); RESCAN(del); |
e4976bb0 | 953 | SKIPSPC; |
f6049fdd | 954 | if (*p == '-') |
d83beb5c | 955 | { p++; NEXTNUMBER(q, del); *max = strtoul(q, 0, 0); RESCAN(del); } |
f6049fdd | 956 | else |
e4976bb0 | 957 | *max = *min; |
958 | } | |
959 | *pp = p; | |
960 | } | |
961 | ||
9314b85a MW |
962 | /* Make a new ACL node. ACT is the verdict; AF is the address family; |
963 | * MINADDR and MAXADDR are the ranges on IP addresses; MINPORT and MAXPORT | |
964 | * are the ranges on port numbers; TAIL is the list tail to attach the new | |
965 | * node to. | |
1d1ccf4f | 966 | */ |
e4976bb0 | 967 | #define ACLNODE(tail_, act_, \ |
9314b85a | 968 | af_, minaddr_, maxaddr_, minport_, maxport_) do { \ |
e4976bb0 | 969 | aclnode *a_; \ |
970 | NEW(a_); \ | |
9314b85a MW |
971 | a_->act = (act_); \ |
972 | a_->af = (af_); \ | |
973 | a_->minaddr = (minaddr_); a_->maxaddr = (maxaddr_); \ | |
974 | a_->minport = (minport_); a_->maxport = (maxport_); \ | |
e4976bb0 | 975 | *tail_ = a_; tail_ = &a_->next; \ |
976 | } while (0) | |
977 | ||
1d1ccf4f MW |
978 | /* Parse an ACL line. *PP points to the end of the line; *TAIL points to |
979 | * the list tail (i.e., the final link in the list). An ACL entry has the | |
980 | * form +|- [any | local | ADDR | ADDR - ADDR | ADDR/ADDR | ADDR/INT] PORTS | |
981 | * where PORTS is parsed by parse_ports above; an ACL line consists of a | |
982 | * comma-separated sequence of entries.. | |
983 | */ | |
e4976bb0 | 984 | static void parse_acl_line(char **pp, aclnode ***tail) |
985 | { | |
9314b85a | 986 | ipaddr minaddr, maxaddr; |
e4976bb0 | 987 | unsigned short minport, maxport; |
9314b85a | 988 | int i, af, n; |
e4976bb0 | 989 | int act; |
990 | int del; | |
991 | char *p = *pp; | |
992 | char *q; | |
993 | ||
a6d9626b | 994 | for (;;) { |
995 | SKIPSPC; | |
996 | if (*p == '+') act = ALLOW; | |
997 | else if (*p == '-') act = DENY; | |
998 | else goto bad; | |
e4976bb0 | 999 | |
a6d9626b | 1000 | p++; |
1001 | SKIPSPC; | |
1002 | if (KWMATCHP("any")) { | |
9314b85a MW |
1003 | parse_ports(&p, &minport, &maxport); |
1004 | for (i = 0; address_families[i] >= 0; i++) { | |
1005 | af = address_families[i]; | |
1006 | memset(&minaddr, 0, sizeof(minaddr)); | |
1007 | maxaddr = minaddr; mask_address(af, &maxaddr, 0, 1); | |
1008 | ACLNODE(*tail, act, af, minaddr, maxaddr, minport, maxport); | |
1009 | } | |
a6d9626b | 1010 | } else if (KWMATCHP("local")) { |
1011 | parse_ports(&p, &minport, &maxport); | |
9314b85a MW |
1012 | for (i = 0; address_families[i] >= 0; i++) { |
1013 | af = address_families[i]; | |
1014 | memset(&minaddr, 0, sizeof(minaddr)); | |
1015 | maxaddr = minaddr; mask_address(af, &maxaddr, 0, 1); | |
1016 | ACLNODE(*tail, act, af, minaddr, minaddr, minport, maxport); | |
1017 | ACLNODE(*tail, act, af, maxaddr, maxaddr, minport, maxport); | |
1018 | } | |
a6d9626b | 1019 | for (i = 0; i < n_local_ipaddrs; i++) { |
9314b85a MW |
1020 | ACLNODE(*tail, act, local_ipaddrs[i].af, |
1021 | local_ipaddrs[i].addr, local_ipaddrs[i].addr, | |
1022 | minport, maxport); | |
a6d9626b | 1023 | } |
e4976bb0 | 1024 | } else { |
9314b85a MW |
1025 | parse_nextaddr(&p, &q, &del); |
1026 | af = guess_address_family(q); | |
1027 | if (inet_pton(af, q, &minaddr) <= 0) goto bad; | |
1028 | RESCAN(del); | |
1029 | SKIPSPC; | |
1030 | if (*p == '-') { | |
1031 | p++; | |
1032 | parse_nextaddr(&p, &q, &del); | |
1033 | if (inet_pton(af, q, &maxaddr) <= 0) goto bad; | |
e4976bb0 | 1034 | RESCAN(del); |
9314b85a MW |
1035 | } else if (*p == '/') { |
1036 | p++; | |
1037 | NEXTNUMBER(q, del); | |
1038 | n = strtoul(q, 0, 0); | |
1039 | maxaddr = minaddr; | |
1040 | mask_address(af, &minaddr, n, 0); | |
1041 | mask_address(af, &maxaddr, n, 1); | |
1042 | } else | |
1043 | maxaddr = minaddr; | |
a6d9626b | 1044 | parse_ports(&p, &minport, &maxport); |
9314b85a | 1045 | ACLNODE(*tail, act, af, minaddr, maxaddr, minport, maxport); |
e4976bb0 | 1046 | } |
a6d9626b | 1047 | SKIPSPC; |
1048 | if (*p != ',') break; | |
1cce4a41 | 1049 | if (*p) p++; |
e4976bb0 | 1050 | } |
f797ea6d | 1051 | *pp = p; |
e4976bb0 | 1052 | return; |
1053 | ||
1054 | bad: | |
1055 | D( fprintf(stderr, "noip: bad acl spec (ignored)\n"); ) | |
1056 | return; | |
1057 | } | |
1058 | ||
1d1ccf4f | 1059 | /* Parse the autoports configuration directive. Syntax is MIN - MAX. */ |
f6049fdd | 1060 | static void parse_autoports(char **pp) |
1061 | { | |
1062 | char *p = *pp, *q; | |
1063 | unsigned x, y; | |
1064 | int del; | |
1065 | ||
1066 | SKIPSPC; | |
1067 | NEXTNUMBER(q, del); x = strtoul(q, 0, 0); RESCAN(del); | |
1068 | SKIPSPC; | |
1069 | if (*p != '-') goto bad; p++; | |
1070 | NEXTNUMBER(q, del); y = strtoul(q, 0, 0); RESCAN(del); | |
1071 | minautoport = x; maxautoport = y; | |
f797ea6d | 1072 | *pp = p; |
f6049fdd | 1073 | return; |
1074 | ||
1075 | bad: | |
1076 | D( fprintf(stderr, "bad port range (ignored)\n"); ) | |
1077 | return; | |
1078 | } | |
1079 | ||
1d1ccf4f MW |
1080 | /* Parse an ACL from an environment variable VAR, attaching it to the list |
1081 | * TAIL. */ | |
a6d9626b | 1082 | static void parse_acl_env(const char *var, aclnode ***tail) |
1083 | { | |
f6049fdd | 1084 | char *p, *q; |
a6d9626b | 1085 | |
1086 | if ((p = getenv(var)) != 0) { | |
f6049fdd | 1087 | p = q = xstrdup(p); |
1088 | parse_acl_line(&q, tail); | |
a6d9626b | 1089 | free(p); |
1090 | } | |
1091 | } | |
1092 | ||
1d1ccf4f | 1093 | /* Read the configuration from the config file and environment. */ |
e4976bb0 | 1094 | static void readconfig(void) |
1095 | { | |
1096 | FILE *fp; | |
1097 | char buf[1024]; | |
1098 | size_t n; | |
f6049fdd | 1099 | char *p, *q, *cmd; |
e4976bb0 | 1100 | |
a6d9626b | 1101 | parse_acl_env("NOIP_REALBIND_BEFORE", &bind_tail); |
1102 | parse_acl_env("NOIP_REALCONNECT_BEFORE", &connect_tail); | |
f6049fdd | 1103 | if ((p = getenv("NOIP_AUTOPORTS")) != 0) { |
1104 | p = q = xstrdup(p); | |
1105 | parse_autoports(&q); | |
1106 | free(p); | |
1107 | } | |
4ab301de | 1108 | if ((p = getenv("NOIP_CONFIG")) == 0) |
1109 | snprintf(p = buf, sizeof(buf), "%s/.noip", home()); | |
1110 | D( fprintf(stderr, "noip: config file: %s\n", p); ) | |
1111 | ||
1112 | if ((fp = fopen(p, "r")) == 0) { | |
1113 | D( fprintf(stderr, "noip: couldn't read config: %s\n", | |
1114 | strerror(errno)); ) | |
f6049fdd | 1115 | goto done; |
4ab301de | 1116 | } |
e4976bb0 | 1117 | while (fgets(buf, sizeof(buf), fp)) { |
1118 | n = strlen(buf); | |
1119 | p = buf; | |
1120 | ||
1121 | SKIPSPC; | |
1122 | if (!*p || *p == '#') continue; | |
1123 | while (n && isspace(UC(buf[n - 1]))) n--; | |
1124 | buf[n] = 0; | |
1125 | NEXTWORD(cmd); | |
1126 | SKIPSPC; | |
1127 | ||
1128 | if (strcmp(cmd, "socketdir") == 0) | |
1129 | sockdir = xstrdup(p); | |
1130 | else if (strcmp(cmd, "realbind") == 0) | |
1131 | parse_acl_line(&p, &bind_tail); | |
1132 | else if (strcmp(cmd, "realconnect") == 0) | |
1133 | parse_acl_line(&p, &connect_tail); | |
f6049fdd | 1134 | else if (strcmp(cmd, "autoports") == 0) |
1135 | parse_autoports(&p); | |
e4976bb0 | 1136 | else if (strcmp(cmd, "debug") == 0) |
1137 | debug = *p ? atoi(p) : 1; | |
1138 | else | |
1139 | D( fprintf(stderr, "noip: bad config command %s\n", cmd); ) | |
1140 | } | |
1141 | fclose(fp); | |
1142 | ||
1143 | done: | |
a6d9626b | 1144 | parse_acl_env("NOIP_REALBIND", &bind_tail); |
1145 | parse_acl_env("NOIP_REALCONNECT", &connect_tail); | |
1146 | parse_acl_env("NOIP_REALBIND_AFTER", &bind_tail); | |
1147 | parse_acl_env("NOIP_REALCONNECT_AFTER", &connect_tail); | |
e4976bb0 | 1148 | *bind_tail = 0; |
1149 | *connect_tail = 0; | |
a6d9626b | 1150 | if (!sockdir) sockdir = getenv("NOIP_SOCKETDIR"); |
e4976bb0 | 1151 | if (!sockdir) { |
1152 | snprintf(buf, sizeof(buf), "%s/noip-%s", tmpdir(), user()); | |
1153 | sockdir = xstrdup(buf); | |
1154 | } | |
3ef1fec9 | 1155 | D( fprintf(stderr, "noip: socketdir: %s\n", sockdir); |
f6049fdd | 1156 | fprintf(stderr, "noip: autoports: %u-%u\n", |
1157 | minautoport, maxautoport); | |
e4976bb0 | 1158 | fprintf(stderr, "noip: realbind acl:\n"); |
1159 | dump_acl(bind_real); | |
1160 | fprintf(stderr, "noip: realconnect acl:\n"); | |
1161 | dump_acl(connect_real); ) | |
1162 | } | |
1163 | ||
1d1ccf4f | 1164 | /*----- Overridden system calls -------------------------------------------*/ |
e4976bb0 | 1165 | |
1166 | int socket(int pf, int ty, int proto) | |
1167 | { | |
8ce11853 | 1168 | switch (pf) { |
9314b85a MW |
1169 | default: |
1170 | if (!family_known_p(pf)) { | |
1171 | errno = EAFNOSUPPORT; | |
1172 | return (-1); | |
1173 | } | |
8ce11853 MW |
1174 | pf = PF_UNIX; |
1175 | proto = 0; | |
1176 | case PF_UNIX: | |
41c50995 MW |
1177 | #ifdef PF_NETLINK |
1178 | case PF_NETLINK: | |
1179 | #endif | |
9314b85a | 1180 | return (real_socket(pf, ty, proto)); |
e4976bb0 | 1181 | } |
e4976bb0 | 1182 | } |
1183 | ||
1184 | int socketpair(int pf, int ty, int proto, int *sk) | |
1185 | { | |
17085e3f | 1186 | if (family_known_p(pf)) { |
e4976bb0 | 1187 | pf = PF_UNIX; |
1188 | proto = 0; | |
1189 | } | |
1190 | return (real_socketpair(pf, ty, proto, sk)); | |
1191 | } | |
1192 | ||
1193 | int bind(int sk, const struct sockaddr *sa, socklen_t len) | |
1194 | { | |
1195 | struct sockaddr_un sun; | |
1196 | ||
9314b85a | 1197 | if (family_known_p(sa->sa_family)) { |
e4976bb0 | 1198 | PRESERVING_ERRNO({ |
9314b85a | 1199 | if (acl_allows_p(bind_real, sa)) { |
86134bfe | 1200 | if (fixup_real_ip_socket(sk, sa->sa_family, 0)) |
e4976bb0 | 1201 | return (-1); |
1202 | } else { | |
9314b85a | 1203 | encode_inet_addr(&sun, sa, WANT_FRESH); |
e4976bb0 | 1204 | sa = SA(&sun); |
1205 | len = SUN_LEN(&sun); | |
1206 | } | |
1207 | }); | |
1208 | } | |
9314b85a | 1209 | return (real_bind(sk, sa, len)); |
e4976bb0 | 1210 | } |
1211 | ||
1212 | int connect(int sk, const struct sockaddr *sa, socklen_t len) | |
1213 | { | |
1214 | struct sockaddr_un sun; | |
53390eff | 1215 | int rc; |
e4976bb0 | 1216 | |
9314b85a MW |
1217 | if (!family_known_p(sa->sa_family)) |
1218 | rc = real_connect(sk, sa, len); | |
1219 | else { | |
1220 | PRESERVING_ERRNO({ | |
1221 | do_implicit_bind(sk, &sa, &len, &sun); | |
1222 | }); | |
1223 | rc = real_connect(sk, sa, len); | |
1224 | if (rc < 0) { | |
1225 | switch (errno) { | |
1226 | case ENOENT: errno = ECONNREFUSED; break; | |
6df6f816 | 1227 | } |
9314b85a | 1228 | } |
53390eff | 1229 | } |
9314b85a | 1230 | return (rc); |
e4976bb0 | 1231 | } |
1232 | ||
1233 | ssize_t sendto(int sk, const void *buf, size_t len, int flags, | |
1234 | const struct sockaddr *to, socklen_t tolen) | |
1235 | { | |
1236 | struct sockaddr_un sun; | |
1237 | ||
17085e3f | 1238 | if (to && family_known_p(to->sa_family)) { |
e4976bb0 | 1239 | PRESERVING_ERRNO({ |
1240 | do_implicit_bind(sk, &to, &tolen, &sun); | |
1241 | }); | |
1242 | } | |
9314b85a | 1243 | return (real_sendto(sk, buf, len, flags, to, tolen)); |
e4976bb0 | 1244 | } |
1245 | ||
1246 | ssize_t recvfrom(int sk, void *buf, size_t len, int flags, | |
1247 | struct sockaddr *from, socklen_t *fromlen) | |
1248 | { | |
1249 | char sabuf[1024]; | |
1250 | socklen_t mylen = sizeof(sabuf); | |
1251 | ssize_t n; | |
1252 | ||
1253 | if (!from) | |
1254 | return real_recvfrom(sk, buf, len, flags, 0, 0); | |
1255 | PRESERVING_ERRNO({ | |
1256 | n = real_recvfrom(sk, buf, len, flags, SA(sabuf), &mylen); | |
1257 | if (n < 0) | |
1258 | return (-1); | |
1259 | return_fake_name(SA(sabuf), mylen, from, fromlen); | |
1260 | }); | |
1261 | return (n); | |
1262 | } | |
1263 | ||
1264 | ssize_t sendmsg(int sk, const struct msghdr *msg, int flags) | |
1265 | { | |
1266 | struct sockaddr_un sun; | |
1267 | const struct sockaddr *sa; | |
1268 | struct msghdr mymsg; | |
1269 | ||
17085e3f | 1270 | if (msg->msg_name && family_known_p(SA(msg->msg_name)->sa_family)) { |
e4976bb0 | 1271 | PRESERVING_ERRNO({ |
1272 | sa = SA(msg->msg_name); | |
1273 | mymsg = *msg; | |
1274 | do_implicit_bind(sk, &sa, &mymsg.msg_namelen, &sun); | |
1275 | mymsg.msg_name = SA(sa); | |
1276 | msg = &mymsg; | |
1277 | }); | |
1278 | } | |
9314b85a | 1279 | return (real_sendmsg(sk, msg, flags)); |
e4976bb0 | 1280 | } |
1281 | ||
1282 | ssize_t recvmsg(int sk, struct msghdr *msg, int flags) | |
1283 | { | |
1284 | char sabuf[1024]; | |
1285 | struct sockaddr *sa; | |
1286 | socklen_t len; | |
1287 | ssize_t n; | |
1288 | ||
1289 | if (!msg->msg_name) | |
9314b85a | 1290 | return (real_recvmsg(sk, msg, flags)); |
e4976bb0 | 1291 | PRESERVING_ERRNO({ |
1292 | sa = SA(msg->msg_name); | |
1293 | len = msg->msg_namelen; | |
1294 | msg->msg_name = sabuf; | |
1295 | msg->msg_namelen = sizeof(sabuf); | |
1296 | n = real_recvmsg(sk, msg, flags); | |
1297 | if (n < 0) | |
1298 | return (-1); | |
1299 | return_fake_name(SA(sabuf), msg->msg_namelen, sa, &len); | |
1300 | msg->msg_name = sa; | |
1301 | msg->msg_namelen = len; | |
1302 | }); | |
1303 | return (n); | |
1304 | } | |
1305 | ||
1306 | int accept(int sk, struct sockaddr *sa, socklen_t *len) | |
1307 | { | |
1308 | char sabuf[1024]; | |
1309 | socklen_t mylen = sizeof(sabuf); | |
1310 | int nsk = real_accept(sk, SA(sabuf), &mylen); | |
1311 | ||
1312 | if (nsk < 0) | |
1313 | return (-1); | |
1314 | return_fake_name(SA(sabuf), mylen, sa, len); | |
1315 | return (nsk); | |
1316 | } | |
1317 | ||
1318 | int getsockname(int sk, struct sockaddr *sa, socklen_t *len) | |
1319 | { | |
1320 | PRESERVING_ERRNO({ | |
1321 | char sabuf[1024]; | |
1322 | socklen_t mylen = sizeof(sabuf); | |
1323 | if (real_getsockname(sk, SA(sabuf), &mylen)) | |
1324 | return (-1); | |
1325 | return_fake_name(SA(sabuf), mylen, sa, len); | |
1326 | }); | |
1327 | return (0); | |
1328 | } | |
1329 | ||
1330 | int getpeername(int sk, struct sockaddr *sa, socklen_t *len) | |
1331 | { | |
1332 | PRESERVING_ERRNO({ | |
1333 | char sabuf[1024]; | |
1334 | socklen_t mylen = sizeof(sabuf); | |
1335 | if (real_getpeername(sk, SA(sabuf), &mylen)) | |
1336 | return (-1); | |
1337 | return_fake_name(SA(sabuf), mylen, sa, len); | |
1338 | }); | |
1339 | return (0); | |
1340 | } | |
1341 | ||
1342 | int getsockopt(int sk, int lev, int opt, void *p, socklen_t *len) | |
1343 | { | |
1344 | switch (lev) { | |
1345 | case SOL_IP: | |
1346 | case SOL_TCP: | |
1347 | case SOL_UDP: | |
1348 | if (*len > 0) | |
1349 | memset(p, 0, *len); | |
1350 | return (0); | |
1351 | } | |
9314b85a | 1352 | return (real_getsockopt(sk, lev, opt, p, len)); |
e4976bb0 | 1353 | } |
1354 | ||
1355 | int setsockopt(int sk, int lev, int opt, const void *p, socklen_t len) | |
1356 | { | |
1357 | switch (lev) { | |
1358 | case SOL_IP: | |
1359 | case SOL_TCP: | |
1360 | case SOL_UDP: | |
1361 | return (0); | |
1362 | } | |
1363 | switch (opt) { | |
1364 | case SO_BINDTODEVICE: | |
1365 | case SO_ATTACH_FILTER: | |
1366 | case SO_DETACH_FILTER: | |
1367 | return (0); | |
1368 | } | |
9314b85a | 1369 | return (real_setsockopt(sk, lev, opt, p, len)); |
e4976bb0 | 1370 | } |
1371 | ||
658c1774 MW |
1372 | int ioctl(int fd, unsigned long op, ...) |
1373 | { | |
1374 | va_list ap; | |
1375 | void *arg; | |
1376 | int sk; | |
1377 | int rc; | |
1378 | ||
1379 | va_start(ap, op); | |
1380 | arg = va_arg(ap, void *); | |
1381 | ||
1382 | switch (op) { | |
1383 | case SIOCGIFADDR: | |
1384 | case SIOCGIFBRDADDR: | |
1385 | case SIOCGIFDSTADDR: | |
1386 | case SIOCGIFNETMASK: | |
1387 | PRESERVING_ERRNO({ | |
1388 | if (fixup_real_ip_socket(fd, AF_INET, &sk)) goto real; | |
1389 | }); | |
1390 | rc = real_ioctl(sk, op, arg); | |
1391 | PRESERVING_ERRNO({ close(sk); }); | |
1392 | break; | |
1393 | default: | |
1394 | real: | |
1395 | rc = real_ioctl(fd, op, arg); | |
1396 | break; | |
1397 | } | |
1398 | va_end(ap); | |
1399 | return (rc); | |
1400 | } | |
1401 | ||
1d1ccf4f | 1402 | /*----- Initialization ----------------------------------------------------*/ |
e4976bb0 | 1403 | |
1d1ccf4f | 1404 | /* Clean up the socket directory, deleting stale sockets. */ |
e4976bb0 | 1405 | static void cleanup_sockdir(void) |
1406 | { | |
1407 | DIR *dir; | |
1408 | struct dirent *d; | |
9314b85a | 1409 | address addr; |
e4976bb0 | 1410 | struct sockaddr_un sun; |
3ef1fec9 | 1411 | struct stat st; |
e4976bb0 | 1412 | |
9314b85a | 1413 | if ((dir = opendir(sockdir)) == 0) return; |
4ab301de | 1414 | sun.sun_family = AF_UNIX; |
e4976bb0 | 1415 | while ((d = readdir(dir)) != 0) { |
1416 | if (d->d_name[0] == '.') continue; | |
1417 | snprintf(sun.sun_path, sizeof(sun.sun_path), | |
1418 | "%s/%s", sockdir, d->d_name); | |
9314b85a | 1419 | if (decode_inet_addr(&addr.sa, 0, &sun, SUN_LEN(&sun)) || |
3ef1fec9 | 1420 | stat(sun.sun_path, &st) || |
4ab301de | 1421 | !S_ISSOCK(st.st_mode)) { |
1422 | D( fprintf(stderr, "noip: ignoring unknown socketdir entry `%s'\n", | |
1423 | sun.sun_path); ) | |
3ef1fec9 | 1424 | continue; |
4ab301de | 1425 | } |
e4976bb0 | 1426 | if (unix_socket_status(&sun, 0) == STALE) { |
1427 | D( fprintf(stderr, "noip: clearing away stale socket %s\n", | |
1428 | d->d_name); ) | |
1429 | unlink(sun.sun_path); | |
1430 | } | |
1431 | } | |
1432 | closedir(dir); | |
1433 | } | |
1434 | ||
1d1ccf4f MW |
1435 | /* Find the addresses attached to local network interfaces, and remember them |
1436 | * in a table. | |
1437 | */ | |
e4976bb0 | 1438 | static void get_local_ipaddrs(void) |
1439 | { | |
9f1396d9 | 1440 | struct ifaddrs *ifa_head, *ifa; |
9314b85a | 1441 | ipaddr a; |
e4976bb0 | 1442 | int i; |
1443 | ||
9f1396d9 MW |
1444 | if (getifaddrs(&ifa_head)) { perror("getifaddrs"); return; } |
1445 | for (n_local_ipaddrs = 0, ifa = ifa_head; | |
1446 | n_local_ipaddrs < MAX_LOCAL_IPADDRS && ifa; | |
1447 | ifa = ifa->ifa_next) { | |
9314b85a | 1448 | if (!ifa->ifa_addr || !family_known_p(ifa->ifa_addr->sa_family)) |
e4976bb0 | 1449 | continue; |
9314b85a MW |
1450 | ipaddr_from_sockaddr(&a, ifa->ifa_addr); |
1451 | D({ char buf[ADDRBUFSZ]; | |
1452 | fprintf(stderr, "noip: local addr %s = %s", ifa->ifa_name, | |
1453 | inet_ntop(ifa->ifa_addr->sa_family, &a, | |
1454 | buf, sizeof(buf))); }) | |
9f1396d9 | 1455 | for (i = 0; i < n_local_ipaddrs; i++) { |
9314b85a MW |
1456 | if (ifa->ifa_addr->sa_family == local_ipaddrs[i].af && |
1457 | ipaddr_equal_p(local_ipaddrs[i].af, &a, &local_ipaddrs[i].addr)) { | |
9f1396d9 MW |
1458 | D( fprintf(stderr, " (duplicate)\n"); ) |
1459 | goto skip; | |
1460 | } | |
1461 | } | |
1462 | D( fprintf(stderr, "\n"); ) | |
9314b85a MW |
1463 | local_ipaddrs[n_local_ipaddrs].af = ifa->ifa_addr->sa_family; |
1464 | local_ipaddrs[n_local_ipaddrs].addr = a; | |
9f1396d9 MW |
1465 | n_local_ipaddrs++; |
1466 | skip:; | |
e4976bb0 | 1467 | } |
9f1396d9 | 1468 | freeifaddrs(ifa_head); |
e4976bb0 | 1469 | } |
1470 | ||
1d1ccf4f | 1471 | /* Print the given message to standard error. Avoids stdio. */ |
72d85cdb | 1472 | static void printerr(const char *p) |
65f3786c | 1473 | { if (write(STDERR_FILENO, p, strlen(p))) ; } |
3ef1fec9 | 1474 | |
1d1ccf4f | 1475 | /* Create the socket directory, being careful about permissions. */ |
3ef1fec9 | 1476 | static void create_sockdir(void) |
1477 | { | |
1478 | struct stat st; | |
1479 | ||
b514afdd | 1480 | if (lstat(sockdir, &st)) { |
3ef1fec9 | 1481 | if (errno == ENOENT) { |
1482 | if (mkdir(sockdir, 0700)) { | |
1483 | perror("noip: creating socketdir"); | |
1484 | exit(127); | |
1485 | } | |
b514afdd | 1486 | if (!lstat(sockdir, &st)) |
3ef1fec9 | 1487 | goto check; |
1488 | } | |
1489 | perror("noip: checking socketdir"); | |
1490 | exit(127); | |
1491 | } | |
1492 | check: | |
1493 | if (!S_ISDIR(st.st_mode)) { | |
1494 | printerr("noip: bad socketdir: not a directory\n"); | |
1495 | exit(127); | |
1496 | } | |
1497 | if (st.st_uid != uid) { | |
1498 | printerr("noip: bad socketdir: not owner\n"); | |
1499 | exit(127); | |
1500 | } | |
1501 | if (st.st_mode & 077) { | |
1502 | printerr("noip: bad socketdir: not private\n"); | |
1503 | exit(127); | |
1504 | } | |
1505 | } | |
1506 | ||
1d1ccf4f MW |
1507 | /* Initialization function. */ |
1508 | static void setup(void) __attribute__((constructor)); | |
e4976bb0 | 1509 | static void setup(void) |
1510 | { | |
1511 | PRESERVING_ERRNO({ | |
1512 | char *p; | |
1513 | ||
1514 | import(); | |
3ef1fec9 | 1515 | uid = geteuid(); |
e4976bb0 | 1516 | if ((p = getenv("NOIP_DEBUG")) && atoi(p)) |
1517 | debug = 1; | |
1518 | get_local_ipaddrs(); | |
1519 | readconfig(); | |
3ef1fec9 | 1520 | create_sockdir(); |
e4976bb0 | 1521 | cleanup_sockdir(); |
1522 | }); | |
1523 | } | |
1d1ccf4f MW |
1524 | |
1525 | /*----- That's all, folks -------------------------------------------------*/ |