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; |
f6049fdd |
45 | static unsigned minautoport = 16384, maxautoport = 65536; |
e4976bb0 |
46 | |
47 | static aclnode *bind_real, **bind_tail = &bind_real; |
48 | static aclnode *connect_real, **connect_tail = &connect_real; |
49 | |
50 | /* --- Import magic --- */ |
51 | |
52 | #define IMPORTS(_) \ |
53 | _(socket, int, (int, int, int)) \ |
54 | _(socketpair, int, (int, int, int, int *)) \ |
55 | _(connect, int, (int, const struct sockaddr *, socklen_t)) \ |
56 | _(bind, int, (int, const struct sockaddr *, socklen_t)) \ |
57 | _(accept, int, (int, struct sockaddr *, socklen_t *)) \ |
58 | _(getsockname, int, (int, struct sockaddr *, socklen_t *)) \ |
59 | _(getpeername, int, (int, struct sockaddr *, socklen_t *)) \ |
60 | _(getsockopt, int, (int, int, int, void *, socklen_t *)) \ |
61 | _(setsockopt, int, (int, int, int, const void *, socklen_t)) \ |
62 | _(sendto, ssize_t, (int, const void *buf, size_t, int, \ |
63 | const struct sockaddr *to, socklen_t tolen)) \ |
64 | _(recvfrom, ssize_t, (int, void *buf, size_t, int, \ |
65 | struct sockaddr *from, socklen_t *fromlen)) \ |
66 | _(sendmsg, ssize_t, (int, const struct msghdr *, int)) \ |
67 | _(recvmsg, ssize_t, (int, struct msghdr *, int)) \ |
68 | _(close, int, (int)) |
69 | |
70 | #define DECL(imp, ret, args) static ret (*real_##imp) args; |
71 | IMPORTS(DECL) |
72 | #undef DECL |
73 | |
74 | static void setup(void) __attribute__((constructor)); |
75 | static void import(void) |
76 | { |
77 | #define IMPORT(imp, ret, args) \ |
78 | real_##imp = (ret (*)args)dlsym(RTLD_NEXT, #imp); |
79 | IMPORTS(IMPORT) |
80 | #undef IMPORT |
81 | } |
82 | |
83 | /* --- Support --- */ |
84 | |
85 | #define SA(sa) ((struct sockaddr *)(sa)) |
86 | #define SIN(sa) ((struct sockaddr_in *)(sa)) |
87 | #define SUN(sa) ((struct sockaddr_un *)(sa)) |
88 | |
89 | #define UC(ch) ((unsigned char)(ch)) |
90 | |
91 | #define NEW(x) ((x) = xmalloc(sizeof(*x))) |
92 | #define NEWV(x, n) ((x) = xmalloc(sizeof(*x) * (n))) |
93 | |
94 | #ifdef DEBUG |
95 | # define D(body) { if (debug) { body } } |
96 | #else |
97 | # define D(body) ; |
98 | #endif |
99 | |
100 | #define PRESERVING_ERRNO(body) do { \ |
101 | int _err = errno; { body } errno = _err; \ |
102 | } while (0) |
103 | |
104 | static void *xmalloc(size_t n) |
105 | { |
106 | void *p; |
107 | if (!n) return (0); |
108 | if ((p = malloc(n)) == 0) { perror("malloc"); exit(1); } |
109 | return (p); |
110 | } |
111 | |
112 | static char *xstrdup(const char *p) |
113 | { |
114 | size_t n = strlen(p) + 1; |
115 | char *q = xmalloc(n); |
116 | memcpy(q, p, n); |
117 | return (q); |
118 | } |
119 | |
120 | static int unix_socket_status(struct sockaddr_un *sun, int quick_p) |
121 | { |
122 | struct stat st; |
123 | FILE *fp = 0; |
124 | size_t len, n; |
125 | int rc; |
126 | char buf[256]; |
127 | |
128 | rc = UNUSED; |
129 | if (stat(sun->sun_path, &st) && errno == ENOENT) |
130 | goto done; |
131 | rc = USED; |
132 | if (quick_p) |
133 | goto done; |
134 | |
135 | if ((fp = fopen("/proc/net/unix", "r")) == 0) |
136 | goto done; |
137 | fgets(buf, sizeof(buf), fp); /* skip header */ |
138 | len = strlen(sun->sun_path); |
139 | while (fgets(buf, sizeof(buf), fp)) { |
140 | n = strlen(buf); |
141 | if (n >= len + 2 && buf[n - len - 2] == ' ' && buf[n - 1] == '\n' && |
142 | memcmp(buf + n - len - 1, sun->sun_path, len) == 0) |
143 | goto done; |
144 | } |
145 | if (ferror(fp)) |
146 | goto done; |
147 | rc = STALE; |
148 | done: |
149 | if (fp) fclose(fp); |
150 | return (rc); |
151 | } |
152 | |
153 | #ifdef DEBUG |
154 | |
155 | static void dump_aclnode(aclnode *a) |
156 | { |
157 | char minbuf[16], maxbuf[16]; |
158 | struct in_addr amin, amax; |
159 | |
160 | amin.s_addr = htonl(a->minaddr); |
161 | amax.s_addr = htonl(a->maxaddr); |
162 | fprintf(stderr, "noip: %c ", a->act ? '+' : '-'); |
163 | if (a->minaddr == 0 && a->maxaddr == 0xffffffff) |
164 | fprintf(stderr, "any"); |
165 | else { |
166 | fprintf(stderr, "%s", |
167 | inet_ntop(AF_INET, &amin, minbuf, sizeof(minbuf))); |
168 | if (a->maxaddr != a->minaddr) { |
169 | fprintf(stderr, "-%s", |
170 | inet_ntop(AF_INET, &amax, maxbuf, sizeof(maxbuf))); |
171 | } |
172 | } |
173 | if (a->minport != 0 || a->maxport != 0xffff) { |
174 | fprintf(stderr, ":%u", (unsigned)a->minport); |
175 | if (a->minport != a->maxport) |
176 | fprintf(stderr, "-%u", (unsigned)a->maxport); |
177 | } |
178 | fputc('\n', stderr); |
179 | } |
180 | |
181 | #endif |
182 | |
183 | static int acl_allows_p(aclnode *a, const struct sockaddr_in *sin) |
184 | { |
185 | unsigned long addr = ntohl(sin->sin_addr.s_addr); |
186 | unsigned short port = ntohs(sin->sin_port); |
187 | int act = ALLOW; |
188 | |
189 | D( char buf[16]; |
190 | fprintf(stderr, "noip: check %s:%u\n", |
191 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
192 | ntohs((unsigned)sin->sin_port)); ) |
193 | for (; a; a = a->next) { |
194 | D( dump_aclnode(a); ) |
195 | if (a->minaddr <= addr && addr <= a->maxaddr && |
196 | a->minport <= port && port <= a->maxport) { |
197 | D( fprintf(stderr, "noip: aha! %s\n", a->act ? "ALLOW" : "DENY"); ) |
198 | return (a->act); |
199 | } |
200 | act = a->act; |
201 | } |
202 | D( fprintf(stderr, "noip: nothing found: %s\n", act ? "DENY" : "ALLOW"); ) |
203 | return (!act); |
204 | } |
205 | |
206 | #ifdef DEBUG |
207 | |
208 | static void dump_acl(aclnode *a) |
209 | { |
210 | int act = ALLOW; |
211 | |
212 | for (; a; a = a->next) { |
213 | dump_aclnode(a); |
214 | act = a->act; |
215 | } |
216 | fprintf(stderr, "noip: [default policy: %s]\n", |
217 | act == ALLOW ? "DENY" : "ALLOW"); |
218 | } |
219 | |
220 | #endif |
221 | |
f6049fdd |
222 | static unsigned randrange(unsigned min, unsigned max) |
223 | { |
224 | unsigned mask, i; |
225 | |
226 | /* It's so nice not to have to care about the quality of the generator |
227 | much! */ |
228 | max -= min; |
229 | for (mask = 1; mask < max; mask = (mask << 1) | 1) |
230 | ; |
231 | do i = rand() & mask; while (i > max); |
232 | return (i + min); |
233 | } |
234 | |
e4976bb0 |
235 | static int encode_inet_addr(struct sockaddr_un *sun, |
236 | const struct sockaddr_in *sin, |
237 | int want) |
238 | { |
239 | int i; |
240 | int desperate_p = 0; |
241 | char buf[INET_ADDRSTRLEN]; |
242 | int rc; |
243 | |
244 | D( fprintf(stderr, "noip: encode %s:%u (%s)", |
245 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
246 | (unsigned)ntohs(sin->sin_port), |
247 | want == WANT_EXISTING ? "EXISTING" : "FRESH"); ) |
248 | sun->sun_family = AF_UNIX; |
249 | if (sin->sin_port || want == WANT_EXISTING) { |
250 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s:%u", sockdir, |
251 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
252 | (unsigned)ntohs(sin->sin_port)); |
253 | rc = unix_socket_status(sun, 0); |
254 | if (rc == STALE) unlink(sun->sun_path); |
255 | if (rc != USED && want == WANT_EXISTING) { |
256 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/0.0.0.0:%u", |
257 | sockdir, (unsigned)ntohs(sin->sin_port)); |
258 | if (unix_socket_status(sun, 0) == STALE) unlink(sun->sun_path); |
259 | } |
260 | } else { |
f6049fdd |
261 | for (i = 0; i < 10; i++) { |
262 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s:%u", sockdir, |
263 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
264 | randrange(minautoport, maxautoport)); |
265 | if (unix_socket_status(sun, 1) == UNUSED) goto found; |
266 | } |
e4976bb0 |
267 | for (desperate_p = 0; desperate_p < 2; desperate_p++) { |
f6049fdd |
268 | for (i = minautoport; i <= maxautoport; i++) { |
e4976bb0 |
269 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s:%u", sockdir, |
270 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
271 | (unsigned)i); |
272 | rc = unix_socket_status(sun, !desperate_p); |
273 | switch (rc) { |
274 | case STALE: unlink(sun->sun_path); |
275 | case UNUSED: goto found; |
276 | } |
277 | } |
278 | } |
279 | errno = EADDRINUSE; |
280 | D( fprintf(stderr, " -- can't resolve\n"); ) |
281 | return (-1); |
282 | found:; |
283 | } |
284 | D( fprintf(stderr, " -> `%s'\n", sun->sun_path); ) |
285 | return (0); |
286 | } |
287 | |
288 | static int decode_inet_addr(struct sockaddr_in *sin, |
289 | const struct sockaddr_un *sun, |
290 | socklen_t len) |
291 | { |
292 | char buf[INET_ADDRSTRLEN + 16]; |
293 | char *p; |
294 | size_t n = strlen(sockdir), nn = strlen(sun->sun_path); |
295 | struct sockaddr_in sin_mine; |
296 | unsigned long port; |
297 | |
298 | if (!sin) |
299 | sin = &sin_mine; |
300 | if (sun->sun_family != AF_UNIX) |
301 | return (-1); |
302 | if (len < sizeof(sun)) ((char *)sun)[len] = 0; |
303 | D( fprintf(stderr, "noip: decode (%d) `%s'", |
304 | *sun->sun_path, sun->sun_path); ) |
305 | if (!sun->sun_path[0]) { |
306 | sin->sin_family = AF_INET; |
307 | sin->sin_addr.s_addr = INADDR_ANY; |
308 | sin->sin_port = 0; |
309 | D( fprintf(stderr, " -- unbound socket\n"); ) |
310 | return (0); |
311 | } |
312 | if (nn < n + 1 || nn - n >= sizeof(buf) || sun->sun_path[n] != '/' || |
313 | memcmp(sun->sun_path, sockdir, n) != 0) { |
314 | D( fprintf(stderr, " -- not one of ours\n"); ) |
315 | return (-1); |
316 | } |
317 | memcpy(buf, sun->sun_path + n + 1, nn - n); |
318 | if ((p = strchr(buf, ':')) == 0) { |
319 | D( fprintf(stderr, " -- malformed (no port)\n"); ) |
320 | return (-1); |
321 | } |
322 | *p++ = 0; |
323 | sin->sin_family = AF_INET; |
324 | if (inet_pton(AF_INET, buf, &sin->sin_addr) <= 0) { |
325 | D( fprintf(stderr, " -- malformed (bad address `%s')\n", buf); ) |
326 | return (-1); |
327 | } |
328 | port = strtoul(p, &p, 10); |
329 | if (*p || port >= 65536) { |
330 | D( fprintf(stderr, " -- malformed (port out of range)"); ) |
331 | return (-1); |
332 | } |
333 | sin->sin_port = htons(port); |
334 | D( fprintf(stderr, " -> %s:%u\n", |
335 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
336 | (unsigned)port); ) |
337 | return (0); |
338 | } |
339 | |
340 | static int fixup_real_ip_socket(int sk) |
341 | { |
342 | int nsk; |
343 | int type; |
344 | int f, fd; |
345 | struct sockaddr_un sun; |
346 | struct sockaddr_in sin; |
347 | socklen_t len; |
348 | |
349 | #define OPTS(_) \ |
350 | _(DEBUG, int) \ |
351 | _(REUSEADDR, int) \ |
352 | _(DONTROUTE, int) \ |
353 | _(BROADCAST, int) \ |
354 | _(SNDBUF, int) \ |
355 | _(RCVBUF, int) \ |
356 | _(OOBINLINE, int) \ |
357 | _(NO_CHECK, int) \ |
358 | _(LINGER, struct linger) \ |
359 | _(BSDCOMPAT, int) \ |
360 | _(RCVLOWAT, int) \ |
361 | _(RCVTIMEO, struct timeval) \ |
362 | _(SNDTIMEO, struct timeval) |
363 | |
364 | len = sizeof(sun); |
365 | if (real_getsockname(sk, SA(&sun), &len)) |
366 | return (-1); |
367 | if (decode_inet_addr(&sin, &sun, len)) |
368 | return (0); /* Not one of ours */ |
369 | len = sizeof(type); |
370 | if (real_getsockopt(sk, SOL_SOCKET, SO_TYPE, &type, &len) < 0 || |
371 | (nsk = real_socket(PF_INET, type, 0)) < 0) |
372 | return (-1); |
373 | #define FIX(opt, ty) do { \ |
374 | ty ov_; \ |
375 | len = sizeof(ov_); \ |
376 | if (real_getsockopt(sk, SOL_SOCKET, SO_##opt, &ov_, &len) < 0 || \ |
377 | real_setsockopt(nsk, SOL_SOCKET, SO_##opt, &ov_, len)) { \ |
378 | real_close(nsk); \ |
379 | return (-1); \ |
380 | } \ |
381 | } while (0); |
382 | OPTS(FIX) |
383 | #undef FIX |
384 | if ((f = fcntl(sk, F_GETFL)) < 0 || |
385 | (fd = fcntl(sk, F_GETFD)) < 0 || |
386 | fcntl(nsk, F_SETFL, f) < 0 || |
387 | dup2(nsk, sk) < 0) { |
388 | real_close(nsk); |
389 | return (-1); |
390 | } |
391 | unlink(sun.sun_path); |
392 | real_close(nsk); |
393 | if (fcntl(sk, F_SETFD, fd) < 0) { |
394 | perror("noip: fixup_real_ip_socket F_SETFD"); |
395 | abort(); |
396 | } |
397 | return (0); |
398 | } |
399 | |
400 | static int do_implicit_bind(int sk, const struct sockaddr **sa, |
401 | socklen_t *len, struct sockaddr_un *sun) |
402 | { |
403 | struct sockaddr_in sin; |
404 | socklen_t mylen = sizeof(*sun); |
405 | |
406 | if (acl_allows_p(connect_real, SIN(*sa))) { |
407 | if (fixup_real_ip_socket(sk)) |
408 | return (-1); |
409 | } else { |
410 | if (real_getsockname(sk, SA(sun), &mylen) < 0) |
411 | return (-1); |
412 | if (sun->sun_family == AF_UNIX) { |
413 | if (mylen < sizeof(*sun)) ((char *)sun)[mylen] = 0; |
414 | if (!sun->sun_path[0]) { |
415 | sin.sin_family = AF_INET; |
416 | sin.sin_addr.s_addr = INADDR_LOOPBACK; |
417 | sin.sin_port = 0; |
418 | encode_inet_addr(sun, &sin, WANT_FRESH); |
419 | if (real_bind(sk, SA(sun), SUN_LEN(sun))) |
420 | return (-1); |
421 | } |
422 | encode_inet_addr(sun, SIN(*sa), WANT_EXISTING); |
423 | *sa = SA(sun); |
424 | *len = SUN_LEN(sun); |
425 | } |
426 | } |
427 | return (0); |
428 | } |
429 | |
430 | static void return_fake_name(struct sockaddr *sa, socklen_t len, |
431 | struct sockaddr *fake, socklen_t *fakelen) |
432 | { |
433 | struct sockaddr_in sin; |
434 | socklen_t alen; |
435 | |
436 | if (sa->sa_family == AF_UNIX && !decode_inet_addr(&sin, SUN(sa), len)) { |
437 | sa = SA(&sin); |
438 | len = sizeof(sin); |
439 | } |
440 | alen = len; |
441 | if (len > *fakelen) |
442 | len = *fakelen; |
443 | if (len > 0) |
444 | memcpy(fake, sa, len); |
445 | *fakelen = alen; |
446 | } |
447 | |
448 | /* --- Configuration --- */ |
449 | |
450 | static char *home(void) |
451 | { |
452 | char *p; |
453 | struct passwd *pw; |
454 | |
455 | if ((p = getenv("HOME")) != 0) return (p); |
456 | else if ((pw = getpwuid(uid)) != 0) return (pw->pw_dir); |
457 | else return "/notexist"; |
458 | } |
459 | |
460 | static char *tmpdir(void) |
461 | { |
462 | char *p; |
463 | |
464 | if ((p = getenv("TMPDIR")) != 0) return (p); |
465 | else if ((p = getenv("TMP")) != 0) return (p); |
466 | else return ("/tmp"); |
467 | } |
468 | |
469 | static char *user(void) |
470 | { |
471 | static char buf[16]; |
472 | char *p; |
473 | struct passwd *pw; |
474 | |
475 | if ((p = getenv("USER")) != 0) return (p); |
476 | else if ((p = getenv("LOGNAME")) != 0) return (p); |
477 | else if ((pw = getpwuid(uid)) != 0) return (pw->pw_name); |
478 | else { |
479 | snprintf(buf, sizeof(buf), "uid-%lu", (unsigned long)uid); |
480 | return (buf); |
481 | } |
482 | } |
483 | |
484 | #define SKIPSPC do { while (*p && isspace(UC(*p))) p++; } while (0) |
485 | #define NEXTWORD(q) do { \ |
486 | SKIPSPC; \ |
487 | q = p; \ |
488 | while (*p && !isspace(UC(*p))) p++; \ |
489 | if (*p) *p++ = 0; \ |
490 | } while (0) |
491 | #define NEXTADDR(q, del) do { \ |
492 | SKIPSPC; \ |
493 | q = p; \ |
494 | while (*p && (*p == '.' || isdigit(UC(*p)))) p++; \ |
495 | del = *p; \ |
496 | if (*p) *p++ = 0; \ |
497 | } while (0) |
498 | #define NEXTNUMBER(q, del) do { \ |
499 | SKIPSPC; \ |
500 | q = p; \ |
501 | while (*p && isdigit(UC(*p))) p++; \ |
502 | del = *p; \ |
503 | if (*p) *p++ = 0; \ |
504 | } while (0) |
505 | #define RESCAN(del) do { if (del) *--p = del; } while (0) |
506 | #define KWMATCHP(kw) (strncmp(p, kw, sizeof(kw) - 1) == 0 && \ |
507 | !isalnum(UC(p[sizeof(kw) - 1])) && \ |
508 | (p += sizeof(kw) - 1)) |
509 | |
510 | static void parse_ports(char **pp, unsigned short *min, unsigned short *max) |
511 | { |
512 | char *p = *pp, *q; |
513 | int del; |
514 | |
515 | SKIPSPC; |
f6049fdd |
516 | if (*p != ':') |
517 | { *min = 0; *max = 0xffff; } |
518 | else { |
e4976bb0 |
519 | p++; |
f6049fdd |
520 | NEXTNUMBER(q, del); *min = strtoul(q, 0, 0); RESCAN(del); |
e4976bb0 |
521 | SKIPSPC; |
f6049fdd |
522 | if (*p == '-') |
523 | { NEXTNUMBER(q, del); *max = strtoul(q, 0, 0); RESCAN(del); } |
524 | else |
e4976bb0 |
525 | *max = *min; |
526 | } |
527 | *pp = p; |
528 | } |
529 | |
530 | #define ACLNODE(tail_, act_, \ |
531 | minaddr_, maxaddr_, minport_, maxport_) do { \ |
532 | aclnode *a_; \ |
533 | NEW(a_); \ |
534 | a_->act = act_; \ |
535 | a_->minaddr = minaddr_; a_->maxaddr = maxaddr_; \ |
536 | a_->minport = minport_; a_->maxport = maxport_; \ |
537 | *tail_ = a_; tail_ = &a_->next; \ |
538 | } while (0) |
539 | |
540 | static void parse_acl_line(char **pp, aclnode ***tail) |
541 | { |
542 | struct in_addr addr; |
543 | unsigned long minaddr, maxaddr, mask; |
544 | unsigned short minport, maxport; |
545 | int i, n; |
546 | int act; |
547 | int del; |
548 | char *p = *pp; |
549 | char *q; |
550 | |
a6d9626b |
551 | for (;;) { |
552 | SKIPSPC; |
553 | if (*p == '+') act = ALLOW; |
554 | else if (*p == '-') act = DENY; |
555 | else goto bad; |
e4976bb0 |
556 | |
a6d9626b |
557 | p++; |
558 | SKIPSPC; |
559 | if (KWMATCHP("any")) { |
e4976bb0 |
560 | minaddr = 0; |
561 | maxaddr = 0xffffffff; |
a6d9626b |
562 | goto justone; |
563 | } else if (KWMATCHP("local")) { |
564 | parse_ports(&p, &minport, &maxport); |
565 | ACLNODE(*tail, act, 0, 0, minport, maxport); |
566 | ACLNODE(*tail, act, 0xffffffff, 0xffffffff, minport, maxport); |
567 | for (i = 0; i < n_local_ipaddrs; i++) { |
568 | minaddr = ntohl(local_ipaddrs[i].s_addr); |
569 | ACLNODE(*tail, act, minaddr, minaddr, minport, maxport); |
570 | } |
e4976bb0 |
571 | } else { |
a6d9626b |
572 | if (*p == ':') { |
573 | minaddr = 0; |
574 | maxaddr = 0xffffffff; |
575 | } else { |
e4976bb0 |
576 | NEXTADDR(q, del); |
577 | if (inet_pton(AF_INET, q, &addr) <= 0) goto bad; |
a6d9626b |
578 | minaddr = ntohl(addr.s_addr); |
e4976bb0 |
579 | RESCAN(del); |
a6d9626b |
580 | SKIPSPC; |
581 | if (*p == '-') { |
582 | p++; |
583 | NEXTADDR(q, del); |
e4976bb0 |
584 | if (inet_pton(AF_INET, q, &addr) <= 0) goto bad; |
a6d9626b |
585 | RESCAN(del); |
586 | maxaddr = ntohl(addr.s_addr); |
587 | } else if (*p == '/') { |
588 | p++; |
589 | NEXTADDR(q, del); |
590 | if (strchr(q, '.')) { |
591 | if (inet_pton(AF_INET, q, &addr) <= 0) goto bad; |
592 | mask = ntohl(addr.s_addr); |
593 | } else { |
f6049fdd |
594 | n = strtoul(q, 0, 0); |
a6d9626b |
595 | mask = (~0ul << (32 - n)) & 0xffffffff; |
596 | } |
597 | RESCAN(del); |
598 | minaddr &= mask; |
599 | maxaddr = minaddr | (mask ^ 0xffffffff); |
600 | } else |
601 | maxaddr = minaddr; |
602 | } |
603 | justone: |
604 | parse_ports(&p, &minport, &maxport); |
605 | ACLNODE(*tail, act, minaddr, maxaddr, minport, maxport); |
e4976bb0 |
606 | } |
a6d9626b |
607 | SKIPSPC; |
608 | if (*p != ',') break; |
609 | p++; |
e4976bb0 |
610 | } |
611 | return; |
612 | |
613 | bad: |
614 | D( fprintf(stderr, "noip: bad acl spec (ignored)\n"); ) |
615 | return; |
616 | } |
617 | |
f6049fdd |
618 | static void parse_autoports(char **pp) |
619 | { |
620 | char *p = *pp, *q; |
621 | unsigned x, y; |
622 | int del; |
623 | |
624 | SKIPSPC; |
625 | NEXTNUMBER(q, del); x = strtoul(q, 0, 0); RESCAN(del); |
626 | SKIPSPC; |
627 | if (*p != '-') goto bad; p++; |
628 | NEXTNUMBER(q, del); y = strtoul(q, 0, 0); RESCAN(del); |
629 | minautoport = x; maxautoport = y; |
630 | return; |
631 | |
632 | bad: |
633 | D( fprintf(stderr, "bad port range (ignored)\n"); ) |
634 | return; |
635 | } |
636 | |
a6d9626b |
637 | static void parse_acl_env(const char *var, aclnode ***tail) |
638 | { |
f6049fdd |
639 | char *p, *q; |
a6d9626b |
640 | |
641 | if ((p = getenv(var)) != 0) { |
f6049fdd |
642 | p = q = xstrdup(p); |
643 | parse_acl_line(&q, tail); |
a6d9626b |
644 | free(p); |
645 | } |
646 | } |
647 | |
e4976bb0 |
648 | static void readconfig(void) |
649 | { |
650 | FILE *fp; |
651 | char buf[1024]; |
652 | size_t n; |
f6049fdd |
653 | char *p, *q, *cmd; |
e4976bb0 |
654 | |
655 | if ((p = getenv("NOIP_CONFIG")) == 0) |
656 | snprintf(p = buf, sizeof(buf), "%s/.noip", home()); |
657 | D( fprintf(stderr, "noip: config file: %s\n", p); ) |
e4976bb0 |
658 | |
a6d9626b |
659 | parse_acl_env("NOIP_REALBIND_BEFORE", &bind_tail); |
660 | parse_acl_env("NOIP_REALCONNECT_BEFORE", &connect_tail); |
f6049fdd |
661 | if ((p = getenv("NOIP_AUTOPORTS")) != 0) { |
662 | p = q = xstrdup(p); |
663 | parse_autoports(&q); |
664 | free(p); |
665 | } |
666 | if ((fp = fopen(p, "r")) == 0) |
667 | goto done; |
e4976bb0 |
668 | while (fgets(buf, sizeof(buf), fp)) { |
669 | n = strlen(buf); |
670 | p = buf; |
671 | |
672 | SKIPSPC; |
673 | if (!*p || *p == '#') continue; |
674 | while (n && isspace(UC(buf[n - 1]))) n--; |
675 | buf[n] = 0; |
676 | NEXTWORD(cmd); |
677 | SKIPSPC; |
678 | |
679 | if (strcmp(cmd, "socketdir") == 0) |
680 | sockdir = xstrdup(p); |
681 | else if (strcmp(cmd, "realbind") == 0) |
682 | parse_acl_line(&p, &bind_tail); |
683 | else if (strcmp(cmd, "realconnect") == 0) |
684 | parse_acl_line(&p, &connect_tail); |
f6049fdd |
685 | else if (strcmp(cmd, "autoports") == 0) |
686 | parse_autoports(&p); |
e4976bb0 |
687 | else if (strcmp(cmd, "debug") == 0) |
688 | debug = *p ? atoi(p) : 1; |
689 | else |
690 | D( fprintf(stderr, "noip: bad config command %s\n", cmd); ) |
691 | } |
692 | fclose(fp); |
693 | |
694 | done: |
a6d9626b |
695 | parse_acl_env("NOIP_REALBIND", &bind_tail); |
696 | parse_acl_env("NOIP_REALCONNECT", &connect_tail); |
697 | parse_acl_env("NOIP_REALBIND_AFTER", &bind_tail); |
698 | parse_acl_env("NOIP_REALCONNECT_AFTER", &connect_tail); |
e4976bb0 |
699 | *bind_tail = 0; |
700 | *connect_tail = 0; |
a6d9626b |
701 | if (!sockdir) sockdir = getenv("NOIP_SOCKETDIR"); |
e4976bb0 |
702 | if (!sockdir) { |
703 | snprintf(buf, sizeof(buf), "%s/noip-%s", tmpdir(), user()); |
704 | sockdir = xstrdup(buf); |
705 | } |
706 | D( fprintf(stderr, "noip: sockdir: %s\n", sockdir); |
f6049fdd |
707 | fprintf(stderr, "noip: autoports: %u-%u\n", |
708 | minautoport, maxautoport); |
e4976bb0 |
709 | fprintf(stderr, "noip: realbind acl:\n"); |
710 | dump_acl(bind_real); |
711 | fprintf(stderr, "noip: realconnect acl:\n"); |
712 | dump_acl(connect_real); ) |
713 | } |
714 | |
715 | /* --- Hooks --- */ |
716 | |
717 | int socket(int pf, int ty, int proto) |
718 | { |
719 | if (pf == PF_INET) { |
720 | pf = PF_UNIX; |
721 | proto = 0; |
722 | } |
723 | return real_socket(pf, ty, proto); |
724 | } |
725 | |
726 | int socketpair(int pf, int ty, int proto, int *sk) |
727 | { |
728 | if (pf == PF_INET) { |
729 | pf = PF_UNIX; |
730 | proto = 0; |
731 | } |
732 | return (real_socketpair(pf, ty, proto, sk)); |
733 | } |
734 | |
735 | int bind(int sk, const struct sockaddr *sa, socklen_t len) |
736 | { |
737 | struct sockaddr_un sun; |
738 | |
739 | if (sa->sa_family == AF_INET) { |
740 | PRESERVING_ERRNO({ |
741 | if (acl_allows_p(bind_real, SIN(sa))) { |
742 | if (fixup_real_ip_socket(sk)) |
743 | return (-1); |
744 | } else { |
745 | encode_inet_addr(&sun, SIN(sa), WANT_FRESH); |
746 | sa = SA(&sun); |
747 | len = SUN_LEN(&sun); |
748 | } |
749 | }); |
750 | } |
751 | return real_bind(sk, sa, len); |
752 | } |
753 | |
754 | int connect(int sk, const struct sockaddr *sa, socklen_t len) |
755 | { |
756 | struct sockaddr_un sun; |
757 | |
758 | if (sa->sa_family == AF_INET) { |
759 | PRESERVING_ERRNO({ |
760 | do_implicit_bind(sk, &sa, &len, &sun); |
761 | }); |
762 | } |
763 | return real_connect(sk, sa, len); |
764 | } |
765 | |
766 | ssize_t sendto(int sk, const void *buf, size_t len, int flags, |
767 | const struct sockaddr *to, socklen_t tolen) |
768 | { |
769 | struct sockaddr_un sun; |
770 | |
771 | if (to && to->sa_family == AF_INET) { |
772 | PRESERVING_ERRNO({ |
773 | do_implicit_bind(sk, &to, &tolen, &sun); |
774 | }); |
775 | } |
776 | return real_sendto(sk, buf, len, flags, to, tolen); |
777 | } |
778 | |
779 | ssize_t recvfrom(int sk, void *buf, size_t len, int flags, |
780 | struct sockaddr *from, socklen_t *fromlen) |
781 | { |
782 | char sabuf[1024]; |
783 | socklen_t mylen = sizeof(sabuf); |
784 | ssize_t n; |
785 | |
786 | if (!from) |
787 | return real_recvfrom(sk, buf, len, flags, 0, 0); |
788 | PRESERVING_ERRNO({ |
789 | n = real_recvfrom(sk, buf, len, flags, SA(sabuf), &mylen); |
790 | if (n < 0) |
791 | return (-1); |
792 | return_fake_name(SA(sabuf), mylen, from, fromlen); |
793 | }); |
794 | return (n); |
795 | } |
796 | |
797 | ssize_t sendmsg(int sk, const struct msghdr *msg, int flags) |
798 | { |
799 | struct sockaddr_un sun; |
800 | const struct sockaddr *sa; |
801 | struct msghdr mymsg; |
802 | |
803 | if (msg->msg_name && SA(msg->msg_name)->sa_family == AF_INET) { |
804 | PRESERVING_ERRNO({ |
805 | sa = SA(msg->msg_name); |
806 | mymsg = *msg; |
807 | do_implicit_bind(sk, &sa, &mymsg.msg_namelen, &sun); |
808 | mymsg.msg_name = SA(sa); |
809 | msg = &mymsg; |
810 | }); |
811 | } |
812 | return real_sendmsg(sk, msg, flags); |
813 | } |
814 | |
815 | ssize_t recvmsg(int sk, struct msghdr *msg, int flags) |
816 | { |
817 | char sabuf[1024]; |
818 | struct sockaddr *sa; |
819 | socklen_t len; |
820 | ssize_t n; |
821 | |
822 | if (!msg->msg_name) |
823 | return real_recvmsg(sk, msg, flags); |
824 | PRESERVING_ERRNO({ |
825 | sa = SA(msg->msg_name); |
826 | len = msg->msg_namelen; |
827 | msg->msg_name = sabuf; |
828 | msg->msg_namelen = sizeof(sabuf); |
829 | n = real_recvmsg(sk, msg, flags); |
830 | if (n < 0) |
831 | return (-1); |
832 | return_fake_name(SA(sabuf), msg->msg_namelen, sa, &len); |
833 | msg->msg_name = sa; |
834 | msg->msg_namelen = len; |
835 | }); |
836 | return (n); |
837 | } |
838 | |
839 | int accept(int sk, struct sockaddr *sa, socklen_t *len) |
840 | { |
841 | char sabuf[1024]; |
842 | socklen_t mylen = sizeof(sabuf); |
843 | int nsk = real_accept(sk, SA(sabuf), &mylen); |
844 | |
845 | if (nsk < 0) |
846 | return (-1); |
847 | return_fake_name(SA(sabuf), mylen, sa, len); |
848 | return (nsk); |
849 | } |
850 | |
851 | int getsockname(int sk, struct sockaddr *sa, socklen_t *len) |
852 | { |
853 | PRESERVING_ERRNO({ |
854 | char sabuf[1024]; |
855 | socklen_t mylen = sizeof(sabuf); |
856 | if (real_getsockname(sk, SA(sabuf), &mylen)) |
857 | return (-1); |
858 | return_fake_name(SA(sabuf), mylen, sa, len); |
859 | }); |
860 | return (0); |
861 | } |
862 | |
863 | int getpeername(int sk, struct sockaddr *sa, socklen_t *len) |
864 | { |
865 | PRESERVING_ERRNO({ |
866 | char sabuf[1024]; |
867 | socklen_t mylen = sizeof(sabuf); |
868 | if (real_getpeername(sk, SA(sabuf), &mylen)) |
869 | return (-1); |
870 | return_fake_name(SA(sabuf), mylen, sa, len); |
871 | }); |
872 | return (0); |
873 | } |
874 | |
875 | int getsockopt(int sk, int lev, int opt, void *p, socklen_t *len) |
876 | { |
877 | switch (lev) { |
878 | case SOL_IP: |
879 | case SOL_TCP: |
880 | case SOL_UDP: |
881 | if (*len > 0) |
882 | memset(p, 0, *len); |
883 | return (0); |
884 | } |
885 | return real_getsockopt(sk, lev, opt, p, len); |
886 | } |
887 | |
888 | int setsockopt(int sk, int lev, int opt, const void *p, socklen_t len) |
889 | { |
890 | switch (lev) { |
891 | case SOL_IP: |
892 | case SOL_TCP: |
893 | case SOL_UDP: |
894 | return (0); |
895 | } |
896 | switch (opt) { |
897 | case SO_BINDTODEVICE: |
898 | case SO_ATTACH_FILTER: |
899 | case SO_DETACH_FILTER: |
900 | return (0); |
901 | } |
902 | return real_setsockopt(sk, lev, opt, p, len); |
903 | } |
904 | |
905 | /* --- Initialization --- */ |
906 | |
907 | static void cleanup_sockdir(void) |
908 | { |
909 | DIR *dir; |
910 | struct dirent *d; |
911 | struct sockaddr_un sun; |
912 | |
913 | if ((dir = opendir(sockdir)) == 0) |
914 | return; |
915 | while ((d = readdir(dir)) != 0) { |
916 | if (d->d_name[0] == '.') continue; |
917 | snprintf(sun.sun_path, sizeof(sun.sun_path), |
918 | "%s/%s", sockdir, d->d_name); |
919 | if (unix_socket_status(&sun, 0) == STALE) { |
920 | D( fprintf(stderr, "noip: clearing away stale socket %s\n", |
921 | d->d_name); ) |
922 | unlink(sun.sun_path); |
923 | } |
924 | } |
925 | closedir(dir); |
926 | } |
927 | |
928 | static void get_local_ipaddrs(void) |
929 | { |
930 | struct if_nameindex *ifn; |
931 | struct ifreq ifr; |
932 | int sk; |
933 | int i; |
934 | |
935 | ifn = if_nameindex(); |
936 | if ((sk = real_socket(PF_INET, SOCK_STREAM, 00)) < 0) |
937 | return; |
938 | for (i = n_local_ipaddrs = 0; |
939 | n_local_ipaddrs < MAX_LOCAL_IPADDRS && |
940 | ifn[i].if_name && *ifn[i].if_name; |
941 | i++) { |
942 | strcpy(ifr.ifr_name, ifn[i].if_name); |
943 | if (ioctl(sk, SIOCGIFADDR, &ifr) || ifr.ifr_addr.sa_family != AF_INET) |
944 | continue; |
945 | local_ipaddrs[n_local_ipaddrs++] = |
946 | SIN(&ifr.ifr_addr)->sin_addr; |
947 | D( fprintf(stderr, "noip: local addr %s = %s\n", ifn[i].if_name, |
948 | inet_ntoa(local_ipaddrs[n_local_ipaddrs - 1])); ) |
949 | } |
950 | close(sk); |
951 | } |
952 | |
953 | static void setup(void) |
954 | { |
955 | PRESERVING_ERRNO({ |
956 | char *p; |
957 | |
958 | import(); |
959 | uid = getuid(); |
960 | if ((p = getenv("NOIP_DEBUG")) && atoi(p)) |
961 | debug = 1; |
962 | get_local_ipaddrs(); |
963 | readconfig(); |
964 | mkdir(sockdir, 0700); |
965 | cleanup_sockdir(); |
966 | }); |
967 | } |