e4976bb0 |
1 | #define _GNU_SOURCE |
2 | #undef sun |
3 | #undef SUN |
4 | #define DEBUG |
5 | |
6 | #include <ctype.h> |
7 | #include <errno.h> |
8 | #include <stdio.h> |
9 | #include <stdlib.h> |
10 | |
11 | #include <unistd.h> |
12 | #include <dirent.h> |
13 | #include <dlfcn.h> |
14 | #include <fcntl.h> |
15 | #include <pwd.h> |
16 | |
17 | #include <sys/ioctl.h> |
18 | #include <sys/socket.h> |
19 | #include <sys/stat.h> |
20 | #include <sys/un.h> |
21 | |
22 | #include <netinet/in.h> |
23 | #include <arpa/inet.h> |
24 | #include <netinet/tcp.h> |
25 | #include <netinet/udp.h> |
26 | #include <net/if.h> |
27 | |
28 | enum { UNUSED, STALE, USED }; |
29 | enum { WANT_FRESH, WANT_EXISTING }; |
30 | enum { DENY, ALLOW }; |
31 | typedef struct aclnode { |
32 | struct aclnode *next; |
33 | int act; |
34 | unsigned long minaddr, maxaddr; |
35 | unsigned short minport, maxport; |
36 | } aclnode; |
37 | |
38 | #define MAX_LOCAL_IPADDRS 16 |
39 | static struct in_addr local_ipaddrs[MAX_LOCAL_IPADDRS]; |
40 | static int n_local_ipaddrs; |
41 | |
42 | static uid_t uid; |
43 | static char *sockdir = 0; |
44 | static int debug = 0; |
45 | |
46 | static aclnode *bind_real, **bind_tail = &bind_real; |
47 | static aclnode *connect_real, **connect_tail = &connect_real; |
48 | |
49 | /* --- Import magic --- */ |
50 | |
51 | #define IMPORTS(_) \ |
52 | _(socket, int, (int, int, int)) \ |
53 | _(socketpair, int, (int, int, int, int *)) \ |
54 | _(connect, int, (int, const struct sockaddr *, socklen_t)) \ |
55 | _(bind, int, (int, const struct sockaddr *, socklen_t)) \ |
56 | _(accept, int, (int, struct sockaddr *, socklen_t *)) \ |
57 | _(getsockname, int, (int, struct sockaddr *, socklen_t *)) \ |
58 | _(getpeername, int, (int, struct sockaddr *, socklen_t *)) \ |
59 | _(getsockopt, int, (int, int, int, void *, socklen_t *)) \ |
60 | _(setsockopt, int, (int, int, int, const void *, socklen_t)) \ |
61 | _(sendto, ssize_t, (int, const void *buf, size_t, int, \ |
62 | const struct sockaddr *to, socklen_t tolen)) \ |
63 | _(recvfrom, ssize_t, (int, void *buf, size_t, int, \ |
64 | struct sockaddr *from, socklen_t *fromlen)) \ |
65 | _(sendmsg, ssize_t, (int, const struct msghdr *, int)) \ |
66 | _(recvmsg, ssize_t, (int, struct msghdr *, int)) \ |
67 | _(close, int, (int)) |
68 | |
69 | #define DECL(imp, ret, args) static ret (*real_##imp) args; |
70 | IMPORTS(DECL) |
71 | #undef DECL |
72 | |
73 | static void setup(void) __attribute__((constructor)); |
74 | static void import(void) |
75 | { |
76 | #define IMPORT(imp, ret, args) \ |
77 | real_##imp = (ret (*)args)dlsym(RTLD_NEXT, #imp); |
78 | IMPORTS(IMPORT) |
79 | #undef IMPORT |
80 | } |
81 | |
82 | /* --- Support --- */ |
83 | |
84 | #define SA(sa) ((struct sockaddr *)(sa)) |
85 | #define SIN(sa) ((struct sockaddr_in *)(sa)) |
86 | #define SUN(sa) ((struct sockaddr_un *)(sa)) |
87 | |
88 | #define UC(ch) ((unsigned char)(ch)) |
89 | |
90 | #define NEW(x) ((x) = xmalloc(sizeof(*x))) |
91 | #define NEWV(x, n) ((x) = xmalloc(sizeof(*x) * (n))) |
92 | |
93 | #ifdef DEBUG |
94 | # define D(body) { if (debug) { body } } |
95 | #else |
96 | # define D(body) ; |
97 | #endif |
98 | |
99 | #define PRESERVING_ERRNO(body) do { \ |
100 | int _err = errno; { body } errno = _err; \ |
101 | } while (0) |
102 | |
103 | static void *xmalloc(size_t n) |
104 | { |
105 | void *p; |
106 | if (!n) return (0); |
107 | if ((p = malloc(n)) == 0) { perror("malloc"); exit(1); } |
108 | return (p); |
109 | } |
110 | |
111 | static char *xstrdup(const char *p) |
112 | { |
113 | size_t n = strlen(p) + 1; |
114 | char *q = xmalloc(n); |
115 | memcpy(q, p, n); |
116 | return (q); |
117 | } |
118 | |
119 | static int unix_socket_status(struct sockaddr_un *sun, int quick_p) |
120 | { |
121 | struct stat st; |
122 | FILE *fp = 0; |
123 | size_t len, n; |
124 | int rc; |
125 | char buf[256]; |
126 | |
127 | rc = UNUSED; |
128 | if (stat(sun->sun_path, &st) && errno == ENOENT) |
129 | goto done; |
130 | rc = USED; |
131 | if (quick_p) |
132 | goto done; |
133 | |
134 | if ((fp = fopen("/proc/net/unix", "r")) == 0) |
135 | goto done; |
136 | fgets(buf, sizeof(buf), fp); /* skip header */ |
137 | len = strlen(sun->sun_path); |
138 | while (fgets(buf, sizeof(buf), fp)) { |
139 | n = strlen(buf); |
140 | if (n >= len + 2 && buf[n - len - 2] == ' ' && buf[n - 1] == '\n' && |
141 | memcmp(buf + n - len - 1, sun->sun_path, len) == 0) |
142 | goto done; |
143 | } |
144 | if (ferror(fp)) |
145 | goto done; |
146 | rc = STALE; |
147 | done: |
148 | if (fp) fclose(fp); |
149 | return (rc); |
150 | } |
151 | |
152 | #ifdef DEBUG |
153 | |
154 | static void dump_aclnode(aclnode *a) |
155 | { |
156 | char minbuf[16], maxbuf[16]; |
157 | struct in_addr amin, amax; |
158 | |
159 | amin.s_addr = htonl(a->minaddr); |
160 | amax.s_addr = htonl(a->maxaddr); |
161 | fprintf(stderr, "noip: %c ", a->act ? '+' : '-'); |
162 | if (a->minaddr == 0 && a->maxaddr == 0xffffffff) |
163 | fprintf(stderr, "any"); |
164 | else { |
165 | fprintf(stderr, "%s", |
166 | inet_ntop(AF_INET, &amin, minbuf, sizeof(minbuf))); |
167 | if (a->maxaddr != a->minaddr) { |
168 | fprintf(stderr, "-%s", |
169 | inet_ntop(AF_INET, &amax, maxbuf, sizeof(maxbuf))); |
170 | } |
171 | } |
172 | if (a->minport != 0 || a->maxport != 0xffff) { |
173 | fprintf(stderr, ":%u", (unsigned)a->minport); |
174 | if (a->minport != a->maxport) |
175 | fprintf(stderr, "-%u", (unsigned)a->maxport); |
176 | } |
177 | fputc('\n', stderr); |
178 | } |
179 | |
180 | #endif |
181 | |
182 | static int acl_allows_p(aclnode *a, const struct sockaddr_in *sin) |
183 | { |
184 | unsigned long addr = ntohl(sin->sin_addr.s_addr); |
185 | unsigned short port = ntohs(sin->sin_port); |
186 | int act = ALLOW; |
187 | |
188 | D( char buf[16]; |
189 | fprintf(stderr, "noip: check %s:%u\n", |
190 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
191 | ntohs((unsigned)sin->sin_port)); ) |
192 | for (; a; a = a->next) { |
193 | D( dump_aclnode(a); ) |
194 | if (a->minaddr <= addr && addr <= a->maxaddr && |
195 | a->minport <= port && port <= a->maxport) { |
196 | D( fprintf(stderr, "noip: aha! %s\n", a->act ? "ALLOW" : "DENY"); ) |
197 | return (a->act); |
198 | } |
199 | act = a->act; |
200 | } |
201 | D( fprintf(stderr, "noip: nothing found: %s\n", act ? "DENY" : "ALLOW"); ) |
202 | return (!act); |
203 | } |
204 | |
205 | #ifdef DEBUG |
206 | |
207 | static void dump_acl(aclnode *a) |
208 | { |
209 | int act = ALLOW; |
210 | |
211 | for (; a; a = a->next) { |
212 | dump_aclnode(a); |
213 | act = a->act; |
214 | } |
215 | fprintf(stderr, "noip: [default policy: %s]\n", |
216 | act == ALLOW ? "DENY" : "ALLOW"); |
217 | } |
218 | |
219 | #endif |
220 | |
221 | static int encode_inet_addr(struct sockaddr_un *sun, |
222 | const struct sockaddr_in *sin, |
223 | int want) |
224 | { |
225 | int i; |
226 | int desperate_p = 0; |
227 | char buf[INET_ADDRSTRLEN]; |
228 | int rc; |
229 | |
230 | D( fprintf(stderr, "noip: encode %s:%u (%s)", |
231 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
232 | (unsigned)ntohs(sin->sin_port), |
233 | want == WANT_EXISTING ? "EXISTING" : "FRESH"); ) |
234 | sun->sun_family = AF_UNIX; |
235 | if (sin->sin_port || want == WANT_EXISTING) { |
236 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s:%u", sockdir, |
237 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
238 | (unsigned)ntohs(sin->sin_port)); |
239 | rc = unix_socket_status(sun, 0); |
240 | if (rc == STALE) unlink(sun->sun_path); |
241 | if (rc != USED && want == WANT_EXISTING) { |
242 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/0.0.0.0:%u", |
243 | sockdir, (unsigned)ntohs(sin->sin_port)); |
244 | if (unix_socket_status(sun, 0) == STALE) unlink(sun->sun_path); |
245 | } |
246 | } else { |
247 | for (desperate_p = 0; desperate_p < 2; desperate_p++) { |
248 | for (i = 16384; i < 65536; i++) { |
249 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s:%u", sockdir, |
250 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
251 | (unsigned)i); |
252 | rc = unix_socket_status(sun, !desperate_p); |
253 | switch (rc) { |
254 | case STALE: unlink(sun->sun_path); |
255 | case UNUSED: goto found; |
256 | } |
257 | } |
258 | } |
259 | errno = EADDRINUSE; |
260 | D( fprintf(stderr, " -- can't resolve\n"); ) |
261 | return (-1); |
262 | found:; |
263 | } |
264 | D( fprintf(stderr, " -> `%s'\n", sun->sun_path); ) |
265 | return (0); |
266 | } |
267 | |
268 | static int decode_inet_addr(struct sockaddr_in *sin, |
269 | const struct sockaddr_un *sun, |
270 | socklen_t len) |
271 | { |
272 | char buf[INET_ADDRSTRLEN + 16]; |
273 | char *p; |
274 | size_t n = strlen(sockdir), nn = strlen(sun->sun_path); |
275 | struct sockaddr_in sin_mine; |
276 | unsigned long port; |
277 | |
278 | if (!sin) |
279 | sin = &sin_mine; |
280 | if (sun->sun_family != AF_UNIX) |
281 | return (-1); |
282 | if (len < sizeof(sun)) ((char *)sun)[len] = 0; |
283 | D( fprintf(stderr, "noip: decode (%d) `%s'", |
284 | *sun->sun_path, sun->sun_path); ) |
285 | if (!sun->sun_path[0]) { |
286 | sin->sin_family = AF_INET; |
287 | sin->sin_addr.s_addr = INADDR_ANY; |
288 | sin->sin_port = 0; |
289 | D( fprintf(stderr, " -- unbound socket\n"); ) |
290 | return (0); |
291 | } |
292 | if (nn < n + 1 || nn - n >= sizeof(buf) || sun->sun_path[n] != '/' || |
293 | memcmp(sun->sun_path, sockdir, n) != 0) { |
294 | D( fprintf(stderr, " -- not one of ours\n"); ) |
295 | return (-1); |
296 | } |
297 | memcpy(buf, sun->sun_path + n + 1, nn - n); |
298 | if ((p = strchr(buf, ':')) == 0) { |
299 | D( fprintf(stderr, " -- malformed (no port)\n"); ) |
300 | return (-1); |
301 | } |
302 | *p++ = 0; |
303 | sin->sin_family = AF_INET; |
304 | if (inet_pton(AF_INET, buf, &sin->sin_addr) <= 0) { |
305 | D( fprintf(stderr, " -- malformed (bad address `%s')\n", buf); ) |
306 | return (-1); |
307 | } |
308 | port = strtoul(p, &p, 10); |
309 | if (*p || port >= 65536) { |
310 | D( fprintf(stderr, " -- malformed (port out of range)"); ) |
311 | return (-1); |
312 | } |
313 | sin->sin_port = htons(port); |
314 | D( fprintf(stderr, " -> %s:%u\n", |
315 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
316 | (unsigned)port); ) |
317 | return (0); |
318 | } |
319 | |
320 | static int fixup_real_ip_socket(int sk) |
321 | { |
322 | int nsk; |
323 | int type; |
324 | int f, fd; |
325 | struct sockaddr_un sun; |
326 | struct sockaddr_in sin; |
327 | socklen_t len; |
328 | |
329 | #define OPTS(_) \ |
330 | _(DEBUG, int) \ |
331 | _(REUSEADDR, int) \ |
332 | _(DONTROUTE, int) \ |
333 | _(BROADCAST, int) \ |
334 | _(SNDBUF, int) \ |
335 | _(RCVBUF, int) \ |
336 | _(OOBINLINE, int) \ |
337 | _(NO_CHECK, int) \ |
338 | _(LINGER, struct linger) \ |
339 | _(BSDCOMPAT, int) \ |
340 | _(RCVLOWAT, int) \ |
341 | _(RCVTIMEO, struct timeval) \ |
342 | _(SNDTIMEO, struct timeval) |
343 | |
344 | len = sizeof(sun); |
345 | if (real_getsockname(sk, SA(&sun), &len)) |
346 | return (-1); |
347 | if (decode_inet_addr(&sin, &sun, len)) |
348 | return (0); /* Not one of ours */ |
349 | len = sizeof(type); |
350 | if (real_getsockopt(sk, SOL_SOCKET, SO_TYPE, &type, &len) < 0 || |
351 | (nsk = real_socket(PF_INET, type, 0)) < 0) |
352 | return (-1); |
353 | #define FIX(opt, ty) do { \ |
354 | ty ov_; \ |
355 | len = sizeof(ov_); \ |
356 | if (real_getsockopt(sk, SOL_SOCKET, SO_##opt, &ov_, &len) < 0 || \ |
357 | real_setsockopt(nsk, SOL_SOCKET, SO_##opt, &ov_, len)) { \ |
358 | real_close(nsk); \ |
359 | return (-1); \ |
360 | } \ |
361 | } while (0); |
362 | OPTS(FIX) |
363 | #undef FIX |
364 | if ((f = fcntl(sk, F_GETFL)) < 0 || |
365 | (fd = fcntl(sk, F_GETFD)) < 0 || |
366 | fcntl(nsk, F_SETFL, f) < 0 || |
367 | dup2(nsk, sk) < 0) { |
368 | real_close(nsk); |
369 | return (-1); |
370 | } |
371 | unlink(sun.sun_path); |
372 | real_close(nsk); |
373 | if (fcntl(sk, F_SETFD, fd) < 0) { |
374 | perror("noip: fixup_real_ip_socket F_SETFD"); |
375 | abort(); |
376 | } |
377 | return (0); |
378 | } |
379 | |
380 | static int do_implicit_bind(int sk, const struct sockaddr **sa, |
381 | socklen_t *len, struct sockaddr_un *sun) |
382 | { |
383 | struct sockaddr_in sin; |
384 | socklen_t mylen = sizeof(*sun); |
385 | |
386 | if (acl_allows_p(connect_real, SIN(*sa))) { |
387 | if (fixup_real_ip_socket(sk)) |
388 | return (-1); |
389 | } else { |
390 | if (real_getsockname(sk, SA(sun), &mylen) < 0) |
391 | return (-1); |
392 | if (sun->sun_family == AF_UNIX) { |
393 | if (mylen < sizeof(*sun)) ((char *)sun)[mylen] = 0; |
394 | if (!sun->sun_path[0]) { |
395 | sin.sin_family = AF_INET; |
396 | sin.sin_addr.s_addr = INADDR_LOOPBACK; |
397 | sin.sin_port = 0; |
398 | encode_inet_addr(sun, &sin, WANT_FRESH); |
399 | if (real_bind(sk, SA(sun), SUN_LEN(sun))) |
400 | return (-1); |
401 | } |
402 | encode_inet_addr(sun, SIN(*sa), WANT_EXISTING); |
403 | *sa = SA(sun); |
404 | *len = SUN_LEN(sun); |
405 | } |
406 | } |
407 | return (0); |
408 | } |
409 | |
410 | static void return_fake_name(struct sockaddr *sa, socklen_t len, |
411 | struct sockaddr *fake, socklen_t *fakelen) |
412 | { |
413 | struct sockaddr_in sin; |
414 | socklen_t alen; |
415 | |
416 | if (sa->sa_family == AF_UNIX && !decode_inet_addr(&sin, SUN(sa), len)) { |
417 | sa = SA(&sin); |
418 | len = sizeof(sin); |
419 | } |
420 | alen = len; |
421 | if (len > *fakelen) |
422 | len = *fakelen; |
423 | if (len > 0) |
424 | memcpy(fake, sa, len); |
425 | *fakelen = alen; |
426 | } |
427 | |
428 | /* --- Configuration --- */ |
429 | |
430 | static char *home(void) |
431 | { |
432 | char *p; |
433 | struct passwd *pw; |
434 | |
435 | if ((p = getenv("HOME")) != 0) return (p); |
436 | else if ((pw = getpwuid(uid)) != 0) return (pw->pw_dir); |
437 | else return "/notexist"; |
438 | } |
439 | |
440 | static char *tmpdir(void) |
441 | { |
442 | char *p; |
443 | |
444 | if ((p = getenv("TMPDIR")) != 0) return (p); |
445 | else if ((p = getenv("TMP")) != 0) return (p); |
446 | else return ("/tmp"); |
447 | } |
448 | |
449 | static char *user(void) |
450 | { |
451 | static char buf[16]; |
452 | char *p; |
453 | struct passwd *pw; |
454 | |
455 | if ((p = getenv("USER")) != 0) return (p); |
456 | else if ((p = getenv("LOGNAME")) != 0) return (p); |
457 | else if ((pw = getpwuid(uid)) != 0) return (pw->pw_name); |
458 | else { |
459 | snprintf(buf, sizeof(buf), "uid-%lu", (unsigned long)uid); |
460 | return (buf); |
461 | } |
462 | } |
463 | |
464 | #define SKIPSPC do { while (*p && isspace(UC(*p))) p++; } while (0) |
465 | #define NEXTWORD(q) do { \ |
466 | SKIPSPC; \ |
467 | q = p; \ |
468 | while (*p && !isspace(UC(*p))) p++; \ |
469 | if (*p) *p++ = 0; \ |
470 | } while (0) |
471 | #define NEXTADDR(q, del) do { \ |
472 | SKIPSPC; \ |
473 | q = p; \ |
474 | while (*p && (*p == '.' || isdigit(UC(*p)))) p++; \ |
475 | del = *p; \ |
476 | if (*p) *p++ = 0; \ |
477 | } while (0) |
478 | #define NEXTNUMBER(q, del) do { \ |
479 | SKIPSPC; \ |
480 | q = p; \ |
481 | while (*p && isdigit(UC(*p))) p++; \ |
482 | del = *p; \ |
483 | if (*p) *p++ = 0; \ |
484 | } while (0) |
485 | #define RESCAN(del) do { if (del) *--p = del; } while (0) |
486 | #define KWMATCHP(kw) (strncmp(p, kw, sizeof(kw) - 1) == 0 && \ |
487 | !isalnum(UC(p[sizeof(kw) - 1])) && \ |
488 | (p += sizeof(kw) - 1)) |
489 | |
490 | static void parse_ports(char **pp, unsigned short *min, unsigned short *max) |
491 | { |
492 | char *p = *pp, *q; |
493 | int del; |
494 | |
495 | SKIPSPC; |
496 | if (*p != ':') { |
497 | *min = 0; |
498 | *max = 0xffff; |
499 | } else { |
500 | p++; |
501 | NEXTNUMBER(q, del); |
502 | *min = atoi(q); |
503 | RESCAN(del); |
504 | SKIPSPC; |
505 | if (*p == '-') { |
506 | NEXTNUMBER(q, del); |
507 | *max = atoi(q); |
508 | RESCAN(del); |
509 | } else |
510 | *max = *min; |
511 | } |
512 | *pp = p; |
513 | } |
514 | |
515 | #define ACLNODE(tail_, act_, \ |
516 | minaddr_, maxaddr_, minport_, maxport_) do { \ |
517 | aclnode *a_; \ |
518 | NEW(a_); \ |
519 | a_->act = act_; \ |
520 | a_->minaddr = minaddr_; a_->maxaddr = maxaddr_; \ |
521 | a_->minport = minport_; a_->maxport = maxport_; \ |
522 | *tail_ = a_; tail_ = &a_->next; \ |
523 | } while (0) |
524 | |
525 | static void parse_acl_line(char **pp, aclnode ***tail) |
526 | { |
527 | struct in_addr addr; |
528 | unsigned long minaddr, maxaddr, mask; |
529 | unsigned short minport, maxport; |
530 | int i, n; |
531 | int act; |
532 | int del; |
533 | char *p = *pp; |
534 | char *q; |
535 | |
536 | SKIPSPC; |
537 | if (*p == '+') act = ALLOW; |
538 | else if (*p == '-') act = DENY; |
539 | else goto bad; |
540 | |
541 | p++; |
542 | SKIPSPC; |
543 | if (KWMATCHP("any")) { |
544 | minaddr = 0; |
545 | maxaddr = 0xffffffff; |
546 | goto justone; |
547 | } else if (KWMATCHP("local")) { |
548 | parse_ports(&p, &minport, &maxport); |
549 | ACLNODE(*tail, act, 0, 0, minport, maxport); |
550 | ACLNODE(*tail, act, 0xffffffff, 0xffffffff, minport, maxport); |
551 | for (i = 0; i < n_local_ipaddrs; i++) { |
552 | minaddr = ntohl(local_ipaddrs[i].s_addr); |
553 | ACLNODE(*tail, act, minaddr, minaddr, minport, maxport); |
554 | } |
555 | } else { |
556 | if (*p == ':') { |
557 | minaddr = 0; |
558 | maxaddr = 0xffffffff; |
559 | } else { |
560 | NEXTADDR(q, del); |
561 | if (inet_pton(AF_INET, q, &addr) <= 0) goto bad; |
562 | minaddr = ntohl(addr.s_addr); |
563 | RESCAN(del); |
564 | SKIPSPC; |
565 | if (*p == '-') { |
566 | p++; |
567 | NEXTADDR(q, del); |
568 | if (inet_pton(AF_INET, q, &addr) <= 0) goto bad; |
569 | RESCAN(del); |
570 | maxaddr = ntohl(addr.s_addr); |
571 | } else if (*p == '/') { |
572 | p++; |
573 | NEXTADDR(q, del); |
574 | if (strchr(q, '.')) { |
575 | if (inet_pton(AF_INET, q, &addr) <= 0) goto bad; |
576 | mask = ntohl(addr.s_addr); |
577 | } else { |
578 | n = atoi(q); |
579 | mask = (~0ul << (32 - n)) & 0xffffffff; |
580 | } |
581 | RESCAN(del); |
582 | minaddr &= mask; |
583 | maxaddr = minaddr | (mask ^ 0xffffffff); |
584 | } else |
585 | maxaddr = minaddr; |
586 | } |
587 | justone: |
588 | parse_ports(&p, &minport, &maxport); |
589 | ACLNODE(*tail, act, minaddr, maxaddr, minport, maxport); |
590 | } |
591 | return; |
592 | |
593 | bad: |
594 | D( fprintf(stderr, "noip: bad acl spec (ignored)\n"); ) |
595 | return; |
596 | } |
597 | |
598 | static void readconfig(void) |
599 | { |
600 | FILE *fp; |
601 | char buf[1024]; |
602 | size_t n; |
603 | char *p, *cmd; |
604 | |
605 | if ((p = getenv("NOIP_CONFIG")) == 0) |
606 | snprintf(p = buf, sizeof(buf), "%s/.noip", home()); |
607 | D( fprintf(stderr, "noip: config file: %s\n", p); ) |
608 | if ((fp = fopen(p, "r")) == 0) |
609 | goto done; |
610 | |
611 | while (fgets(buf, sizeof(buf), fp)) { |
612 | n = strlen(buf); |
613 | p = buf; |
614 | |
615 | SKIPSPC; |
616 | if (!*p || *p == '#') continue; |
617 | while (n && isspace(UC(buf[n - 1]))) n--; |
618 | buf[n] = 0; |
619 | NEXTWORD(cmd); |
620 | SKIPSPC; |
621 | |
622 | if (strcmp(cmd, "socketdir") == 0) |
623 | sockdir = xstrdup(p); |
624 | else if (strcmp(cmd, "realbind") == 0) |
625 | parse_acl_line(&p, &bind_tail); |
626 | else if (strcmp(cmd, "realconnect") == 0) |
627 | parse_acl_line(&p, &connect_tail); |
628 | else if (strcmp(cmd, "debug") == 0) |
629 | debug = *p ? atoi(p) : 1; |
630 | else |
631 | D( fprintf(stderr, "noip: bad config command %s\n", cmd); ) |
632 | } |
633 | fclose(fp); |
634 | |
635 | done: |
636 | *bind_tail = 0; |
637 | *connect_tail = 0; |
638 | if (!sockdir) { |
639 | snprintf(buf, sizeof(buf), "%s/noip-%s", tmpdir(), user()); |
640 | sockdir = xstrdup(buf); |
641 | } |
642 | D( fprintf(stderr, "noip: sockdir: %s\n", sockdir); |
643 | fprintf(stderr, "noip: realbind acl:\n"); |
644 | dump_acl(bind_real); |
645 | fprintf(stderr, "noip: realconnect acl:\n"); |
646 | dump_acl(connect_real); ) |
647 | } |
648 | |
649 | /* --- Hooks --- */ |
650 | |
651 | int socket(int pf, int ty, int proto) |
652 | { |
653 | if (pf == PF_INET) { |
654 | pf = PF_UNIX; |
655 | proto = 0; |
656 | } |
657 | return real_socket(pf, ty, proto); |
658 | } |
659 | |
660 | int socketpair(int pf, int ty, int proto, int *sk) |
661 | { |
662 | if (pf == PF_INET) { |
663 | pf = PF_UNIX; |
664 | proto = 0; |
665 | } |
666 | return (real_socketpair(pf, ty, proto, sk)); |
667 | } |
668 | |
669 | int bind(int sk, const struct sockaddr *sa, socklen_t len) |
670 | { |
671 | struct sockaddr_un sun; |
672 | |
673 | if (sa->sa_family == AF_INET) { |
674 | PRESERVING_ERRNO({ |
675 | if (acl_allows_p(bind_real, SIN(sa))) { |
676 | if (fixup_real_ip_socket(sk)) |
677 | return (-1); |
678 | } else { |
679 | encode_inet_addr(&sun, SIN(sa), WANT_FRESH); |
680 | sa = SA(&sun); |
681 | len = SUN_LEN(&sun); |
682 | } |
683 | }); |
684 | } |
685 | return real_bind(sk, sa, len); |
686 | } |
687 | |
688 | int connect(int sk, const struct sockaddr *sa, socklen_t len) |
689 | { |
690 | struct sockaddr_un sun; |
691 | |
692 | if (sa->sa_family == AF_INET) { |
693 | PRESERVING_ERRNO({ |
694 | do_implicit_bind(sk, &sa, &len, &sun); |
695 | }); |
696 | } |
697 | return real_connect(sk, sa, len); |
698 | } |
699 | |
700 | ssize_t sendto(int sk, const void *buf, size_t len, int flags, |
701 | const struct sockaddr *to, socklen_t tolen) |
702 | { |
703 | struct sockaddr_un sun; |
704 | |
705 | if (to && to->sa_family == AF_INET) { |
706 | PRESERVING_ERRNO({ |
707 | do_implicit_bind(sk, &to, &tolen, &sun); |
708 | }); |
709 | } |
710 | return real_sendto(sk, buf, len, flags, to, tolen); |
711 | } |
712 | |
713 | ssize_t recvfrom(int sk, void *buf, size_t len, int flags, |
714 | struct sockaddr *from, socklen_t *fromlen) |
715 | { |
716 | char sabuf[1024]; |
717 | socklen_t mylen = sizeof(sabuf); |
718 | ssize_t n; |
719 | |
720 | if (!from) |
721 | return real_recvfrom(sk, buf, len, flags, 0, 0); |
722 | PRESERVING_ERRNO({ |
723 | n = real_recvfrom(sk, buf, len, flags, SA(sabuf), &mylen); |
724 | if (n < 0) |
725 | return (-1); |
726 | return_fake_name(SA(sabuf), mylen, from, fromlen); |
727 | }); |
728 | return (n); |
729 | } |
730 | |
731 | ssize_t sendmsg(int sk, const struct msghdr *msg, int flags) |
732 | { |
733 | struct sockaddr_un sun; |
734 | const struct sockaddr *sa; |
735 | struct msghdr mymsg; |
736 | |
737 | if (msg->msg_name && SA(msg->msg_name)->sa_family == AF_INET) { |
738 | PRESERVING_ERRNO({ |
739 | sa = SA(msg->msg_name); |
740 | mymsg = *msg; |
741 | do_implicit_bind(sk, &sa, &mymsg.msg_namelen, &sun); |
742 | mymsg.msg_name = SA(sa); |
743 | msg = &mymsg; |
744 | }); |
745 | } |
746 | return real_sendmsg(sk, msg, flags); |
747 | } |
748 | |
749 | ssize_t recvmsg(int sk, struct msghdr *msg, int flags) |
750 | { |
751 | char sabuf[1024]; |
752 | struct sockaddr *sa; |
753 | socklen_t len; |
754 | ssize_t n; |
755 | |
756 | if (!msg->msg_name) |
757 | return real_recvmsg(sk, msg, flags); |
758 | PRESERVING_ERRNO({ |
759 | sa = SA(msg->msg_name); |
760 | len = msg->msg_namelen; |
761 | msg->msg_name = sabuf; |
762 | msg->msg_namelen = sizeof(sabuf); |
763 | n = real_recvmsg(sk, msg, flags); |
764 | if (n < 0) |
765 | return (-1); |
766 | return_fake_name(SA(sabuf), msg->msg_namelen, sa, &len); |
767 | msg->msg_name = sa; |
768 | msg->msg_namelen = len; |
769 | }); |
770 | return (n); |
771 | } |
772 | |
773 | int accept(int sk, struct sockaddr *sa, socklen_t *len) |
774 | { |
775 | char sabuf[1024]; |
776 | socklen_t mylen = sizeof(sabuf); |
777 | int nsk = real_accept(sk, SA(sabuf), &mylen); |
778 | |
779 | if (nsk < 0) |
780 | return (-1); |
781 | return_fake_name(SA(sabuf), mylen, sa, len); |
782 | return (nsk); |
783 | } |
784 | |
785 | int getsockname(int sk, struct sockaddr *sa, socklen_t *len) |
786 | { |
787 | PRESERVING_ERRNO({ |
788 | char sabuf[1024]; |
789 | socklen_t mylen = sizeof(sabuf); |
790 | if (real_getsockname(sk, SA(sabuf), &mylen)) |
791 | return (-1); |
792 | return_fake_name(SA(sabuf), mylen, sa, len); |
793 | }); |
794 | return (0); |
795 | } |
796 | |
797 | int getpeername(int sk, struct sockaddr *sa, socklen_t *len) |
798 | { |
799 | PRESERVING_ERRNO({ |
800 | char sabuf[1024]; |
801 | socklen_t mylen = sizeof(sabuf); |
802 | if (real_getpeername(sk, SA(sabuf), &mylen)) |
803 | return (-1); |
804 | return_fake_name(SA(sabuf), mylen, sa, len); |
805 | }); |
806 | return (0); |
807 | } |
808 | |
809 | int getsockopt(int sk, int lev, int opt, void *p, socklen_t *len) |
810 | { |
811 | switch (lev) { |
812 | case SOL_IP: |
813 | case SOL_TCP: |
814 | case SOL_UDP: |
815 | if (*len > 0) |
816 | memset(p, 0, *len); |
817 | return (0); |
818 | } |
819 | return real_getsockopt(sk, lev, opt, p, len); |
820 | } |
821 | |
822 | int setsockopt(int sk, int lev, int opt, const void *p, socklen_t len) |
823 | { |
824 | switch (lev) { |
825 | case SOL_IP: |
826 | case SOL_TCP: |
827 | case SOL_UDP: |
828 | return (0); |
829 | } |
830 | switch (opt) { |
831 | case SO_BINDTODEVICE: |
832 | case SO_ATTACH_FILTER: |
833 | case SO_DETACH_FILTER: |
834 | return (0); |
835 | } |
836 | return real_setsockopt(sk, lev, opt, p, len); |
837 | } |
838 | |
839 | /* --- Initialization --- */ |
840 | |
841 | static void cleanup_sockdir(void) |
842 | { |
843 | DIR *dir; |
844 | struct dirent *d; |
845 | struct sockaddr_un sun; |
846 | |
847 | if ((dir = opendir(sockdir)) == 0) |
848 | return; |
849 | while ((d = readdir(dir)) != 0) { |
850 | if (d->d_name[0] == '.') continue; |
851 | snprintf(sun.sun_path, sizeof(sun.sun_path), |
852 | "%s/%s", sockdir, d->d_name); |
853 | if (unix_socket_status(&sun, 0) == STALE) { |
854 | D( fprintf(stderr, "noip: clearing away stale socket %s\n", |
855 | d->d_name); ) |
856 | unlink(sun.sun_path); |
857 | } |
858 | } |
859 | closedir(dir); |
860 | } |
861 | |
862 | static void get_local_ipaddrs(void) |
863 | { |
864 | struct if_nameindex *ifn; |
865 | struct ifreq ifr; |
866 | int sk; |
867 | int i; |
868 | |
869 | ifn = if_nameindex(); |
870 | if ((sk = real_socket(PF_INET, SOCK_STREAM, 00)) < 0) |
871 | return; |
872 | for (i = n_local_ipaddrs = 0; |
873 | n_local_ipaddrs < MAX_LOCAL_IPADDRS && |
874 | ifn[i].if_name && *ifn[i].if_name; |
875 | i++) { |
876 | strcpy(ifr.ifr_name, ifn[i].if_name); |
877 | if (ioctl(sk, SIOCGIFADDR, &ifr) || ifr.ifr_addr.sa_family != AF_INET) |
878 | continue; |
879 | local_ipaddrs[n_local_ipaddrs++] = |
880 | SIN(&ifr.ifr_addr)->sin_addr; |
881 | D( fprintf(stderr, "noip: local addr %s = %s\n", ifn[i].if_name, |
882 | inet_ntoa(local_ipaddrs[n_local_ipaddrs - 1])); ) |
883 | } |
884 | close(sk); |
885 | } |
886 | |
887 | static void setup(void) |
888 | { |
889 | PRESERVING_ERRNO({ |
890 | char *p; |
891 | |
892 | import(); |
893 | uid = getuid(); |
894 | if ((p = getenv("NOIP_DEBUG")) && atoi(p)) |
895 | debug = 1; |
896 | get_local_ipaddrs(); |
897 | readconfig(); |
898 | mkdir(sockdir, 0700); |
899 | cleanup_sockdir(); |
900 | }); |
901 | } |