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); |
3ef1fec9 |
108 | if ((p = malloc(n)) == 0) { perror("malloc"); exit(127); } |
e4976bb0 |
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 | |
3ef1fec9 |
120 | static int unix_socket_status(struct sockaddr_un *sun, int quickp) |
e4976bb0 |
121 | { |
122 | struct stat st; |
123 | FILE *fp = 0; |
124 | size_t len, n; |
125 | int rc; |
126 | char buf[256]; |
127 | |
3ef1fec9 |
128 | if (stat(sun->sun_path, &st)) |
129 | return (errno == ENOENT ? UNUSED : USED); |
4ab301de |
130 | if (!S_ISSOCK(st.st_mode) || quickp) |
3ef1fec9 |
131 | return (USED); |
e4976bb0 |
132 | rc = USED; |
e4976bb0 |
133 | if ((fp = fopen("/proc/net/unix", "r")) == 0) |
134 | goto done; |
135 | fgets(buf, sizeof(buf), fp); /* skip header */ |
136 | len = strlen(sun->sun_path); |
137 | while (fgets(buf, sizeof(buf), fp)) { |
138 | n = strlen(buf); |
139 | if (n >= len + 2 && buf[n - len - 2] == ' ' && buf[n - 1] == '\n' && |
140 | memcmp(buf + n - len - 1, sun->sun_path, len) == 0) |
141 | goto done; |
142 | } |
143 | if (ferror(fp)) |
144 | goto done; |
145 | rc = STALE; |
146 | done: |
147 | if (fp) fclose(fp); |
148 | return (rc); |
149 | } |
150 | |
151 | #ifdef DEBUG |
152 | |
153 | static void dump_aclnode(aclnode *a) |
154 | { |
155 | char minbuf[16], maxbuf[16]; |
156 | struct in_addr amin, amax; |
157 | |
158 | amin.s_addr = htonl(a->minaddr); |
159 | amax.s_addr = htonl(a->maxaddr); |
160 | fprintf(stderr, "noip: %c ", a->act ? '+' : '-'); |
161 | if (a->minaddr == 0 && a->maxaddr == 0xffffffff) |
162 | fprintf(stderr, "any"); |
163 | else { |
164 | fprintf(stderr, "%s", |
165 | inet_ntop(AF_INET, &amin, minbuf, sizeof(minbuf))); |
166 | if (a->maxaddr != a->minaddr) { |
167 | fprintf(stderr, "-%s", |
168 | inet_ntop(AF_INET, &amax, maxbuf, sizeof(maxbuf))); |
169 | } |
170 | } |
171 | if (a->minport != 0 || a->maxport != 0xffff) { |
172 | fprintf(stderr, ":%u", (unsigned)a->minport); |
173 | if (a->minport != a->maxport) |
174 | fprintf(stderr, "-%u", (unsigned)a->maxport); |
175 | } |
176 | fputc('\n', stderr); |
177 | } |
178 | |
179 | #endif |
180 | |
181 | static int acl_allows_p(aclnode *a, const struct sockaddr_in *sin) |
182 | { |
183 | unsigned long addr = ntohl(sin->sin_addr.s_addr); |
184 | unsigned short port = ntohs(sin->sin_port); |
185 | int act = ALLOW; |
186 | |
187 | D( char buf[16]; |
188 | fprintf(stderr, "noip: check %s:%u\n", |
189 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
190 | ntohs((unsigned)sin->sin_port)); ) |
191 | for (; a; a = a->next) { |
192 | D( dump_aclnode(a); ) |
193 | if (a->minaddr <= addr && addr <= a->maxaddr && |
194 | a->minport <= port && port <= a->maxport) { |
195 | D( fprintf(stderr, "noip: aha! %s\n", a->act ? "ALLOW" : "DENY"); ) |
196 | return (a->act); |
197 | } |
198 | act = a->act; |
199 | } |
200 | D( fprintf(stderr, "noip: nothing found: %s\n", act ? "DENY" : "ALLOW"); ) |
201 | return (!act); |
202 | } |
203 | |
204 | #ifdef DEBUG |
205 | |
206 | static void dump_acl(aclnode *a) |
207 | { |
208 | int act = ALLOW; |
209 | |
210 | for (; a; a = a->next) { |
211 | dump_aclnode(a); |
212 | act = a->act; |
213 | } |
214 | fprintf(stderr, "noip: [default policy: %s]\n", |
215 | act == ALLOW ? "DENY" : "ALLOW"); |
216 | } |
217 | |
218 | #endif |
219 | |
f6049fdd |
220 | static unsigned randrange(unsigned min, unsigned max) |
221 | { |
222 | unsigned mask, i; |
223 | |
224 | /* It's so nice not to have to care about the quality of the generator |
225 | much! */ |
226 | max -= min; |
227 | for (mask = 1; mask < max; mask = (mask << 1) | 1) |
228 | ; |
229 | do i = rand() & mask; while (i > max); |
230 | return (i + min); |
231 | } |
232 | |
e4976bb0 |
233 | static int encode_inet_addr(struct sockaddr_un *sun, |
234 | const struct sockaddr_in *sin, |
235 | int want) |
236 | { |
237 | int i; |
3ef1fec9 |
238 | int desperatep = 0; |
e4976bb0 |
239 | char buf[INET_ADDRSTRLEN]; |
240 | int rc; |
241 | |
242 | D( fprintf(stderr, "noip: encode %s:%u (%s)", |
243 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
244 | (unsigned)ntohs(sin->sin_port), |
245 | want == WANT_EXISTING ? "EXISTING" : "FRESH"); ) |
246 | sun->sun_family = AF_UNIX; |
247 | if (sin->sin_port || want == WANT_EXISTING) { |
248 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s:%u", sockdir, |
249 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
250 | (unsigned)ntohs(sin->sin_port)); |
251 | rc = unix_socket_status(sun, 0); |
252 | if (rc == STALE) unlink(sun->sun_path); |
253 | if (rc != USED && want == WANT_EXISTING) { |
254 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/0.0.0.0:%u", |
255 | sockdir, (unsigned)ntohs(sin->sin_port)); |
256 | if (unix_socket_status(sun, 0) == STALE) unlink(sun->sun_path); |
257 | } |
258 | } else { |
f6049fdd |
259 | for (i = 0; i < 10; i++) { |
260 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s:%u", sockdir, |
261 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
262 | randrange(minautoport, maxautoport)); |
263 | if (unix_socket_status(sun, 1) == UNUSED) goto found; |
264 | } |
3ef1fec9 |
265 | for (desperatep = 0; desperatep < 2; desperatep++) { |
f6049fdd |
266 | for (i = minautoport; i <= maxautoport; i++) { |
e4976bb0 |
267 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s:%u", sockdir, |
268 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
269 | (unsigned)i); |
3ef1fec9 |
270 | rc = unix_socket_status(sun, !desperatep); |
e4976bb0 |
271 | switch (rc) { |
272 | case STALE: unlink(sun->sun_path); |
273 | case UNUSED: goto found; |
274 | } |
275 | } |
276 | } |
277 | errno = EADDRINUSE; |
278 | D( fprintf(stderr, " -- can't resolve\n"); ) |
279 | return (-1); |
280 | found:; |
281 | } |
282 | D( fprintf(stderr, " -> `%s'\n", sun->sun_path); ) |
283 | return (0); |
284 | } |
285 | |
286 | static int decode_inet_addr(struct sockaddr_in *sin, |
287 | const struct sockaddr_un *sun, |
288 | socklen_t len) |
289 | { |
290 | char buf[INET_ADDRSTRLEN + 16]; |
291 | char *p; |
292 | size_t n = strlen(sockdir), nn = strlen(sun->sun_path); |
293 | struct sockaddr_in sin_mine; |
294 | unsigned long port; |
295 | |
296 | if (!sin) |
297 | sin = &sin_mine; |
298 | if (sun->sun_family != AF_UNIX) |
299 | return (-1); |
300 | if (len < sizeof(sun)) ((char *)sun)[len] = 0; |
301 | D( fprintf(stderr, "noip: decode (%d) `%s'", |
302 | *sun->sun_path, sun->sun_path); ) |
303 | if (!sun->sun_path[0]) { |
304 | sin->sin_family = AF_INET; |
305 | sin->sin_addr.s_addr = INADDR_ANY; |
306 | sin->sin_port = 0; |
307 | D( fprintf(stderr, " -- unbound socket\n"); ) |
308 | return (0); |
309 | } |
310 | if (nn < n + 1 || nn - n >= sizeof(buf) || sun->sun_path[n] != '/' || |
311 | memcmp(sun->sun_path, sockdir, n) != 0) { |
312 | D( fprintf(stderr, " -- not one of ours\n"); ) |
313 | return (-1); |
314 | } |
315 | memcpy(buf, sun->sun_path + n + 1, nn - n); |
316 | if ((p = strchr(buf, ':')) == 0) { |
317 | D( fprintf(stderr, " -- malformed (no port)\n"); ) |
318 | return (-1); |
319 | } |
320 | *p++ = 0; |
321 | sin->sin_family = AF_INET; |
322 | if (inet_pton(AF_INET, buf, &sin->sin_addr) <= 0) { |
323 | D( fprintf(stderr, " -- malformed (bad address `%s')\n", buf); ) |
324 | return (-1); |
325 | } |
326 | port = strtoul(p, &p, 10); |
327 | if (*p || port >= 65536) { |
328 | D( fprintf(stderr, " -- malformed (port out of range)"); ) |
329 | return (-1); |
330 | } |
331 | sin->sin_port = htons(port); |
332 | D( fprintf(stderr, " -> %s:%u\n", |
333 | inet_ntop(AF_INET, &sin->sin_addr, buf, sizeof(buf)), |
334 | (unsigned)port); ) |
335 | return (0); |
336 | } |
337 | |
338 | static int fixup_real_ip_socket(int sk) |
339 | { |
340 | int nsk; |
341 | int type; |
342 | int f, fd; |
343 | struct sockaddr_un sun; |
344 | struct sockaddr_in sin; |
345 | socklen_t len; |
346 | |
347 | #define OPTS(_) \ |
348 | _(DEBUG, int) \ |
349 | _(REUSEADDR, int) \ |
350 | _(DONTROUTE, int) \ |
351 | _(BROADCAST, int) \ |
352 | _(SNDBUF, int) \ |
353 | _(RCVBUF, int) \ |
354 | _(OOBINLINE, int) \ |
355 | _(NO_CHECK, int) \ |
356 | _(LINGER, struct linger) \ |
357 | _(BSDCOMPAT, int) \ |
358 | _(RCVLOWAT, int) \ |
359 | _(RCVTIMEO, struct timeval) \ |
360 | _(SNDTIMEO, struct timeval) |
361 | |
362 | len = sizeof(sun); |
363 | if (real_getsockname(sk, SA(&sun), &len)) |
364 | return (-1); |
365 | if (decode_inet_addr(&sin, &sun, len)) |
366 | return (0); /* Not one of ours */ |
367 | len = sizeof(type); |
368 | if (real_getsockopt(sk, SOL_SOCKET, SO_TYPE, &type, &len) < 0 || |
369 | (nsk = real_socket(PF_INET, type, 0)) < 0) |
370 | return (-1); |
371 | #define FIX(opt, ty) do { \ |
372 | ty ov_; \ |
373 | len = sizeof(ov_); \ |
374 | if (real_getsockopt(sk, SOL_SOCKET, SO_##opt, &ov_, &len) < 0 || \ |
375 | real_setsockopt(nsk, SOL_SOCKET, SO_##opt, &ov_, len)) { \ |
376 | real_close(nsk); \ |
377 | return (-1); \ |
378 | } \ |
379 | } while (0); |
380 | OPTS(FIX) |
381 | #undef FIX |
382 | if ((f = fcntl(sk, F_GETFL)) < 0 || |
383 | (fd = fcntl(sk, F_GETFD)) < 0 || |
384 | fcntl(nsk, F_SETFL, f) < 0 || |
385 | dup2(nsk, sk) < 0) { |
386 | real_close(nsk); |
387 | return (-1); |
388 | } |
389 | unlink(sun.sun_path); |
390 | real_close(nsk); |
391 | if (fcntl(sk, F_SETFD, fd) < 0) { |
392 | perror("noip: fixup_real_ip_socket F_SETFD"); |
393 | abort(); |
394 | } |
395 | return (0); |
396 | } |
397 | |
398 | static int do_implicit_bind(int sk, const struct sockaddr **sa, |
399 | socklen_t *len, struct sockaddr_un *sun) |
400 | { |
401 | struct sockaddr_in sin; |
402 | socklen_t mylen = sizeof(*sun); |
403 | |
404 | if (acl_allows_p(connect_real, SIN(*sa))) { |
405 | if (fixup_real_ip_socket(sk)) |
406 | return (-1); |
407 | } else { |
408 | if (real_getsockname(sk, SA(sun), &mylen) < 0) |
409 | return (-1); |
410 | if (sun->sun_family == AF_UNIX) { |
411 | if (mylen < sizeof(*sun)) ((char *)sun)[mylen] = 0; |
412 | if (!sun->sun_path[0]) { |
413 | sin.sin_family = AF_INET; |
4ab301de |
414 | sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK); |
e4976bb0 |
415 | sin.sin_port = 0; |
416 | encode_inet_addr(sun, &sin, WANT_FRESH); |
417 | if (real_bind(sk, SA(sun), SUN_LEN(sun))) |
418 | return (-1); |
419 | } |
420 | encode_inet_addr(sun, SIN(*sa), WANT_EXISTING); |
421 | *sa = SA(sun); |
422 | *len = SUN_LEN(sun); |
423 | } |
424 | } |
425 | return (0); |
426 | } |
427 | |
428 | static void return_fake_name(struct sockaddr *sa, socklen_t len, |
429 | struct sockaddr *fake, socklen_t *fakelen) |
430 | { |
431 | struct sockaddr_in sin; |
432 | socklen_t alen; |
433 | |
434 | if (sa->sa_family == AF_UNIX && !decode_inet_addr(&sin, SUN(sa), len)) { |
435 | sa = SA(&sin); |
436 | len = sizeof(sin); |
437 | } |
438 | alen = len; |
439 | if (len > *fakelen) |
440 | len = *fakelen; |
441 | if (len > 0) |
442 | memcpy(fake, sa, len); |
443 | *fakelen = alen; |
444 | } |
445 | |
446 | /* --- Configuration --- */ |
447 | |
448 | static char *home(void) |
449 | { |
450 | char *p; |
451 | struct passwd *pw; |
452 | |
3ef1fec9 |
453 | if (getuid() == uid && |
454 | (p = getenv("HOME")) != 0) |
455 | return (p); |
456 | else if ((pw = getpwuid(uid)) != 0) |
457 | return (pw->pw_dir); |
458 | else |
459 | return "/notexist"; |
e4976bb0 |
460 | } |
461 | |
462 | static char *tmpdir(void) |
463 | { |
464 | char *p; |
465 | |
466 | if ((p = getenv("TMPDIR")) != 0) return (p); |
467 | else if ((p = getenv("TMP")) != 0) return (p); |
468 | else return ("/tmp"); |
469 | } |
470 | |
471 | static char *user(void) |
472 | { |
473 | static char buf[16]; |
474 | char *p; |
475 | struct passwd *pw; |
476 | |
477 | if ((p = getenv("USER")) != 0) return (p); |
478 | else if ((p = getenv("LOGNAME")) != 0) return (p); |
479 | else if ((pw = getpwuid(uid)) != 0) return (pw->pw_name); |
480 | else { |
481 | snprintf(buf, sizeof(buf), "uid-%lu", (unsigned long)uid); |
482 | return (buf); |
483 | } |
484 | } |
485 | |
486 | #define SKIPSPC do { while (*p && isspace(UC(*p))) p++; } while (0) |
487 | #define NEXTWORD(q) do { \ |
488 | SKIPSPC; \ |
489 | q = p; \ |
490 | while (*p && !isspace(UC(*p))) p++; \ |
491 | if (*p) *p++ = 0; \ |
492 | } while (0) |
493 | #define NEXTADDR(q, del) do { \ |
494 | SKIPSPC; \ |
495 | q = p; \ |
496 | while (*p && (*p == '.' || isdigit(UC(*p)))) p++; \ |
497 | del = *p; \ |
498 | if (*p) *p++ = 0; \ |
499 | } while (0) |
500 | #define NEXTNUMBER(q, del) do { \ |
501 | SKIPSPC; \ |
502 | q = p; \ |
503 | while (*p && isdigit(UC(*p))) p++; \ |
504 | del = *p; \ |
505 | if (*p) *p++ = 0; \ |
506 | } while (0) |
507 | #define RESCAN(del) do { if (del) *--p = del; } while (0) |
508 | #define KWMATCHP(kw) (strncmp(p, kw, sizeof(kw) - 1) == 0 && \ |
509 | !isalnum(UC(p[sizeof(kw) - 1])) && \ |
510 | (p += sizeof(kw) - 1)) |
511 | |
512 | static void parse_ports(char **pp, unsigned short *min, unsigned short *max) |
513 | { |
514 | char *p = *pp, *q; |
515 | int del; |
516 | |
517 | SKIPSPC; |
f6049fdd |
518 | if (*p != ':') |
519 | { *min = 0; *max = 0xffff; } |
520 | else { |
e4976bb0 |
521 | p++; |
f6049fdd |
522 | NEXTNUMBER(q, del); *min = strtoul(q, 0, 0); RESCAN(del); |
e4976bb0 |
523 | SKIPSPC; |
f6049fdd |
524 | if (*p == '-') |
d83beb5c |
525 | { p++; NEXTNUMBER(q, del); *max = strtoul(q, 0, 0); RESCAN(del); } |
f6049fdd |
526 | else |
e4976bb0 |
527 | *max = *min; |
528 | } |
529 | *pp = p; |
530 | } |
531 | |
532 | #define ACLNODE(tail_, act_, \ |
533 | minaddr_, maxaddr_, minport_, maxport_) do { \ |
534 | aclnode *a_; \ |
535 | NEW(a_); \ |
536 | a_->act = act_; \ |
537 | a_->minaddr = minaddr_; a_->maxaddr = maxaddr_; \ |
538 | a_->minport = minport_; a_->maxport = maxport_; \ |
539 | *tail_ = a_; tail_ = &a_->next; \ |
540 | } while (0) |
541 | |
542 | static void parse_acl_line(char **pp, aclnode ***tail) |
543 | { |
544 | struct in_addr addr; |
545 | unsigned long minaddr, maxaddr, mask; |
546 | unsigned short minport, maxport; |
547 | int i, n; |
548 | int act; |
549 | int del; |
550 | char *p = *pp; |
551 | char *q; |
552 | |
a6d9626b |
553 | for (;;) { |
554 | SKIPSPC; |
555 | if (*p == '+') act = ALLOW; |
556 | else if (*p == '-') act = DENY; |
557 | else goto bad; |
e4976bb0 |
558 | |
a6d9626b |
559 | p++; |
560 | SKIPSPC; |
561 | if (KWMATCHP("any")) { |
e4976bb0 |
562 | minaddr = 0; |
563 | maxaddr = 0xffffffff; |
a6d9626b |
564 | goto justone; |
565 | } else if (KWMATCHP("local")) { |
566 | parse_ports(&p, &minport, &maxport); |
567 | ACLNODE(*tail, act, 0, 0, minport, maxport); |
568 | ACLNODE(*tail, act, 0xffffffff, 0xffffffff, minport, maxport); |
569 | for (i = 0; i < n_local_ipaddrs; i++) { |
570 | minaddr = ntohl(local_ipaddrs[i].s_addr); |
571 | ACLNODE(*tail, act, minaddr, minaddr, minport, maxport); |
572 | } |
e4976bb0 |
573 | } else { |
a6d9626b |
574 | if (*p == ':') { |
575 | minaddr = 0; |
576 | maxaddr = 0xffffffff; |
577 | } else { |
e4976bb0 |
578 | NEXTADDR(q, del); |
579 | if (inet_pton(AF_INET, q, &addr) <= 0) goto bad; |
a6d9626b |
580 | minaddr = ntohl(addr.s_addr); |
e4976bb0 |
581 | RESCAN(del); |
a6d9626b |
582 | SKIPSPC; |
583 | if (*p == '-') { |
584 | p++; |
585 | NEXTADDR(q, del); |
e4976bb0 |
586 | if (inet_pton(AF_INET, q, &addr) <= 0) goto bad; |
a6d9626b |
587 | RESCAN(del); |
588 | maxaddr = ntohl(addr.s_addr); |
589 | } else if (*p == '/') { |
590 | p++; |
591 | NEXTADDR(q, del); |
592 | if (strchr(q, '.')) { |
593 | if (inet_pton(AF_INET, q, &addr) <= 0) goto bad; |
594 | mask = ntohl(addr.s_addr); |
595 | } else { |
f6049fdd |
596 | n = strtoul(q, 0, 0); |
a6d9626b |
597 | mask = (~0ul << (32 - n)) & 0xffffffff; |
598 | } |
599 | RESCAN(del); |
600 | minaddr &= mask; |
601 | maxaddr = minaddr | (mask ^ 0xffffffff); |
602 | } else |
603 | maxaddr = minaddr; |
604 | } |
605 | justone: |
606 | parse_ports(&p, &minport, &maxport); |
607 | ACLNODE(*tail, act, minaddr, maxaddr, minport, maxport); |
e4976bb0 |
608 | } |
a6d9626b |
609 | SKIPSPC; |
610 | if (*p != ',') break; |
611 | p++; |
e4976bb0 |
612 | } |
613 | return; |
614 | |
615 | bad: |
616 | D( fprintf(stderr, "noip: bad acl spec (ignored)\n"); ) |
617 | return; |
618 | } |
619 | |
f6049fdd |
620 | static void parse_autoports(char **pp) |
621 | { |
622 | char *p = *pp, *q; |
623 | unsigned x, y; |
624 | int del; |
625 | |
626 | SKIPSPC; |
627 | NEXTNUMBER(q, del); x = strtoul(q, 0, 0); RESCAN(del); |
628 | SKIPSPC; |
629 | if (*p != '-') goto bad; p++; |
630 | NEXTNUMBER(q, del); y = strtoul(q, 0, 0); RESCAN(del); |
631 | minautoport = x; maxautoport = y; |
632 | return; |
633 | |
634 | bad: |
635 | D( fprintf(stderr, "bad port range (ignored)\n"); ) |
636 | return; |
637 | } |
638 | |
a6d9626b |
639 | static void parse_acl_env(const char *var, aclnode ***tail) |
640 | { |
f6049fdd |
641 | char *p, *q; |
a6d9626b |
642 | |
643 | if ((p = getenv(var)) != 0) { |
f6049fdd |
644 | p = q = xstrdup(p); |
645 | parse_acl_line(&q, tail); |
a6d9626b |
646 | free(p); |
647 | } |
648 | } |
649 | |
e4976bb0 |
650 | static void readconfig(void) |
651 | { |
652 | FILE *fp; |
653 | char buf[1024]; |
654 | size_t n; |
f6049fdd |
655 | char *p, *q, *cmd; |
e4976bb0 |
656 | |
a6d9626b |
657 | parse_acl_env("NOIP_REALBIND_BEFORE", &bind_tail); |
658 | parse_acl_env("NOIP_REALCONNECT_BEFORE", &connect_tail); |
f6049fdd |
659 | if ((p = getenv("NOIP_AUTOPORTS")) != 0) { |
660 | p = q = xstrdup(p); |
661 | parse_autoports(&q); |
662 | free(p); |
663 | } |
4ab301de |
664 | if ((p = getenv("NOIP_CONFIG")) == 0) |
665 | snprintf(p = buf, sizeof(buf), "%s/.noip", home()); |
666 | D( fprintf(stderr, "noip: config file: %s\n", p); ) |
667 | |
668 | if ((fp = fopen(p, "r")) == 0) { |
669 | D( fprintf(stderr, "noip: couldn't read config: %s\n", |
670 | strerror(errno)); ) |
f6049fdd |
671 | goto done; |
4ab301de |
672 | } |
e4976bb0 |
673 | while (fgets(buf, sizeof(buf), fp)) { |
674 | n = strlen(buf); |
675 | p = buf; |
676 | |
677 | SKIPSPC; |
678 | if (!*p || *p == '#') continue; |
679 | while (n && isspace(UC(buf[n - 1]))) n--; |
680 | buf[n] = 0; |
681 | NEXTWORD(cmd); |
682 | SKIPSPC; |
683 | |
684 | if (strcmp(cmd, "socketdir") == 0) |
685 | sockdir = xstrdup(p); |
686 | else if (strcmp(cmd, "realbind") == 0) |
687 | parse_acl_line(&p, &bind_tail); |
688 | else if (strcmp(cmd, "realconnect") == 0) |
689 | parse_acl_line(&p, &connect_tail); |
f6049fdd |
690 | else if (strcmp(cmd, "autoports") == 0) |
691 | parse_autoports(&p); |
e4976bb0 |
692 | else if (strcmp(cmd, "debug") == 0) |
693 | debug = *p ? atoi(p) : 1; |
694 | else |
695 | D( fprintf(stderr, "noip: bad config command %s\n", cmd); ) |
696 | } |
697 | fclose(fp); |
698 | |
699 | done: |
a6d9626b |
700 | parse_acl_env("NOIP_REALBIND", &bind_tail); |
701 | parse_acl_env("NOIP_REALCONNECT", &connect_tail); |
702 | parse_acl_env("NOIP_REALBIND_AFTER", &bind_tail); |
703 | parse_acl_env("NOIP_REALCONNECT_AFTER", &connect_tail); |
e4976bb0 |
704 | *bind_tail = 0; |
705 | *connect_tail = 0; |
a6d9626b |
706 | if (!sockdir) sockdir = getenv("NOIP_SOCKETDIR"); |
e4976bb0 |
707 | if (!sockdir) { |
708 | snprintf(buf, sizeof(buf), "%s/noip-%s", tmpdir(), user()); |
709 | sockdir = xstrdup(buf); |
710 | } |
3ef1fec9 |
711 | D( fprintf(stderr, "noip: socketdir: %s\n", sockdir); |
f6049fdd |
712 | fprintf(stderr, "noip: autoports: %u-%u\n", |
713 | minautoport, maxautoport); |
e4976bb0 |
714 | fprintf(stderr, "noip: realbind acl:\n"); |
715 | dump_acl(bind_real); |
716 | fprintf(stderr, "noip: realconnect acl:\n"); |
717 | dump_acl(connect_real); ) |
718 | } |
719 | |
720 | /* --- Hooks --- */ |
721 | |
722 | int socket(int pf, int ty, int proto) |
723 | { |
724 | if (pf == PF_INET) { |
725 | pf = PF_UNIX; |
726 | proto = 0; |
727 | } |
728 | return real_socket(pf, ty, proto); |
729 | } |
730 | |
731 | int socketpair(int pf, int ty, int proto, int *sk) |
732 | { |
733 | if (pf == PF_INET) { |
734 | pf = PF_UNIX; |
735 | proto = 0; |
736 | } |
737 | return (real_socketpair(pf, ty, proto, sk)); |
738 | } |
739 | |
740 | int bind(int sk, const struct sockaddr *sa, socklen_t len) |
741 | { |
742 | struct sockaddr_un sun; |
743 | |
744 | if (sa->sa_family == AF_INET) { |
745 | PRESERVING_ERRNO({ |
746 | if (acl_allows_p(bind_real, SIN(sa))) { |
747 | if (fixup_real_ip_socket(sk)) |
748 | return (-1); |
749 | } else { |
750 | encode_inet_addr(&sun, SIN(sa), WANT_FRESH); |
751 | sa = SA(&sun); |
752 | len = SUN_LEN(&sun); |
753 | } |
754 | }); |
755 | } |
756 | return real_bind(sk, sa, len); |
757 | } |
758 | |
759 | int connect(int sk, const struct sockaddr *sa, socklen_t len) |
760 | { |
761 | struct sockaddr_un sun; |
762 | |
763 | if (sa->sa_family == AF_INET) { |
764 | PRESERVING_ERRNO({ |
765 | do_implicit_bind(sk, &sa, &len, &sun); |
766 | }); |
767 | } |
768 | return real_connect(sk, sa, len); |
769 | } |
770 | |
771 | ssize_t sendto(int sk, const void *buf, size_t len, int flags, |
772 | const struct sockaddr *to, socklen_t tolen) |
773 | { |
774 | struct sockaddr_un sun; |
775 | |
776 | if (to && to->sa_family == AF_INET) { |
777 | PRESERVING_ERRNO({ |
778 | do_implicit_bind(sk, &to, &tolen, &sun); |
779 | }); |
780 | } |
781 | return real_sendto(sk, buf, len, flags, to, tolen); |
782 | } |
783 | |
784 | ssize_t recvfrom(int sk, void *buf, size_t len, int flags, |
785 | struct sockaddr *from, socklen_t *fromlen) |
786 | { |
787 | char sabuf[1024]; |
788 | socklen_t mylen = sizeof(sabuf); |
789 | ssize_t n; |
790 | |
791 | if (!from) |
792 | return real_recvfrom(sk, buf, len, flags, 0, 0); |
793 | PRESERVING_ERRNO({ |
794 | n = real_recvfrom(sk, buf, len, flags, SA(sabuf), &mylen); |
795 | if (n < 0) |
796 | return (-1); |
797 | return_fake_name(SA(sabuf), mylen, from, fromlen); |
798 | }); |
799 | return (n); |
800 | } |
801 | |
802 | ssize_t sendmsg(int sk, const struct msghdr *msg, int flags) |
803 | { |
804 | struct sockaddr_un sun; |
805 | const struct sockaddr *sa; |
806 | struct msghdr mymsg; |
807 | |
808 | if (msg->msg_name && SA(msg->msg_name)->sa_family == AF_INET) { |
809 | PRESERVING_ERRNO({ |
810 | sa = SA(msg->msg_name); |
811 | mymsg = *msg; |
812 | do_implicit_bind(sk, &sa, &mymsg.msg_namelen, &sun); |
813 | mymsg.msg_name = SA(sa); |
814 | msg = &mymsg; |
815 | }); |
816 | } |
817 | return real_sendmsg(sk, msg, flags); |
818 | } |
819 | |
820 | ssize_t recvmsg(int sk, struct msghdr *msg, int flags) |
821 | { |
822 | char sabuf[1024]; |
823 | struct sockaddr *sa; |
824 | socklen_t len; |
825 | ssize_t n; |
826 | |
827 | if (!msg->msg_name) |
828 | return real_recvmsg(sk, msg, flags); |
829 | PRESERVING_ERRNO({ |
830 | sa = SA(msg->msg_name); |
831 | len = msg->msg_namelen; |
832 | msg->msg_name = sabuf; |
833 | msg->msg_namelen = sizeof(sabuf); |
834 | n = real_recvmsg(sk, msg, flags); |
835 | if (n < 0) |
836 | return (-1); |
837 | return_fake_name(SA(sabuf), msg->msg_namelen, sa, &len); |
838 | msg->msg_name = sa; |
839 | msg->msg_namelen = len; |
840 | }); |
841 | return (n); |
842 | } |
843 | |
844 | int accept(int sk, struct sockaddr *sa, socklen_t *len) |
845 | { |
846 | char sabuf[1024]; |
847 | socklen_t mylen = sizeof(sabuf); |
848 | int nsk = real_accept(sk, SA(sabuf), &mylen); |
849 | |
850 | if (nsk < 0) |
851 | return (-1); |
852 | return_fake_name(SA(sabuf), mylen, sa, len); |
853 | return (nsk); |
854 | } |
855 | |
856 | int getsockname(int sk, struct sockaddr *sa, socklen_t *len) |
857 | { |
858 | PRESERVING_ERRNO({ |
859 | char sabuf[1024]; |
860 | socklen_t mylen = sizeof(sabuf); |
861 | if (real_getsockname(sk, SA(sabuf), &mylen)) |
862 | return (-1); |
863 | return_fake_name(SA(sabuf), mylen, sa, len); |
864 | }); |
865 | return (0); |
866 | } |
867 | |
868 | int getpeername(int sk, struct sockaddr *sa, socklen_t *len) |
869 | { |
870 | PRESERVING_ERRNO({ |
871 | char sabuf[1024]; |
872 | socklen_t mylen = sizeof(sabuf); |
873 | if (real_getpeername(sk, SA(sabuf), &mylen)) |
874 | return (-1); |
875 | return_fake_name(SA(sabuf), mylen, sa, len); |
876 | }); |
877 | return (0); |
878 | } |
879 | |
880 | int getsockopt(int sk, int lev, int opt, void *p, socklen_t *len) |
881 | { |
882 | switch (lev) { |
883 | case SOL_IP: |
884 | case SOL_TCP: |
885 | case SOL_UDP: |
886 | if (*len > 0) |
887 | memset(p, 0, *len); |
888 | return (0); |
889 | } |
890 | return real_getsockopt(sk, lev, opt, p, len); |
891 | } |
892 | |
893 | int setsockopt(int sk, int lev, int opt, const void *p, socklen_t len) |
894 | { |
895 | switch (lev) { |
896 | case SOL_IP: |
897 | case SOL_TCP: |
898 | case SOL_UDP: |
899 | return (0); |
900 | } |
901 | switch (opt) { |
902 | case SO_BINDTODEVICE: |
903 | case SO_ATTACH_FILTER: |
904 | case SO_DETACH_FILTER: |
905 | return (0); |
906 | } |
907 | return real_setsockopt(sk, lev, opt, p, len); |
908 | } |
909 | |
910 | /* --- Initialization --- */ |
911 | |
912 | static void cleanup_sockdir(void) |
913 | { |
914 | DIR *dir; |
915 | struct dirent *d; |
3ef1fec9 |
916 | struct sockaddr_in sin; |
e4976bb0 |
917 | struct sockaddr_un sun; |
3ef1fec9 |
918 | struct stat st; |
e4976bb0 |
919 | |
920 | if ((dir = opendir(sockdir)) == 0) |
921 | return; |
4ab301de |
922 | sun.sun_family = AF_UNIX; |
e4976bb0 |
923 | while ((d = readdir(dir)) != 0) { |
924 | if (d->d_name[0] == '.') continue; |
925 | snprintf(sun.sun_path, sizeof(sun.sun_path), |
926 | "%s/%s", sockdir, d->d_name); |
3ef1fec9 |
927 | if (decode_inet_addr(&sin, &sun, SUN_LEN(&sun)) || |
928 | stat(sun.sun_path, &st) || |
4ab301de |
929 | !S_ISSOCK(st.st_mode)) { |
930 | D( fprintf(stderr, "noip: ignoring unknown socketdir entry `%s'\n", |
931 | sun.sun_path); ) |
3ef1fec9 |
932 | continue; |
4ab301de |
933 | } |
e4976bb0 |
934 | if (unix_socket_status(&sun, 0) == STALE) { |
935 | D( fprintf(stderr, "noip: clearing away stale socket %s\n", |
936 | d->d_name); ) |
937 | unlink(sun.sun_path); |
938 | } |
939 | } |
940 | closedir(dir); |
941 | } |
942 | |
943 | static void get_local_ipaddrs(void) |
944 | { |
945 | struct if_nameindex *ifn; |
946 | struct ifreq ifr; |
947 | int sk; |
948 | int i; |
949 | |
950 | ifn = if_nameindex(); |
951 | if ((sk = real_socket(PF_INET, SOCK_STREAM, 00)) < 0) |
952 | return; |
953 | for (i = n_local_ipaddrs = 0; |
954 | n_local_ipaddrs < MAX_LOCAL_IPADDRS && |
955 | ifn[i].if_name && *ifn[i].if_name; |
956 | i++) { |
957 | strcpy(ifr.ifr_name, ifn[i].if_name); |
958 | if (ioctl(sk, SIOCGIFADDR, &ifr) || ifr.ifr_addr.sa_family != AF_INET) |
959 | continue; |
960 | local_ipaddrs[n_local_ipaddrs++] = |
961 | SIN(&ifr.ifr_addr)->sin_addr; |
962 | D( fprintf(stderr, "noip: local addr %s = %s\n", ifn[i].if_name, |
963 | inet_ntoa(local_ipaddrs[n_local_ipaddrs - 1])); ) |
964 | } |
965 | close(sk); |
966 | } |
967 | |
3ef1fec9 |
968 | static void printerr(const char *p) { write(STDERR_FILENO, p, strlen(p)); } |
969 | |
970 | static void create_sockdir(void) |
971 | { |
972 | struct stat st; |
973 | |
974 | if (stat(sockdir, &st)) { |
975 | if (errno == ENOENT) { |
976 | if (mkdir(sockdir, 0700)) { |
977 | perror("noip: creating socketdir"); |
978 | exit(127); |
979 | } |
980 | if (!stat(sockdir, &st)) |
981 | goto check; |
982 | } |
983 | perror("noip: checking socketdir"); |
984 | exit(127); |
985 | } |
986 | check: |
987 | if (!S_ISDIR(st.st_mode)) { |
988 | printerr("noip: bad socketdir: not a directory\n"); |
989 | exit(127); |
990 | } |
991 | if (st.st_uid != uid) { |
992 | printerr("noip: bad socketdir: not owner\n"); |
993 | exit(127); |
994 | } |
995 | if (st.st_mode & 077) { |
996 | printerr("noip: bad socketdir: not private\n"); |
997 | exit(127); |
998 | } |
999 | } |
1000 | |
e4976bb0 |
1001 | static void setup(void) |
1002 | { |
1003 | PRESERVING_ERRNO({ |
1004 | char *p; |
1005 | |
1006 | import(); |
3ef1fec9 |
1007 | uid = geteuid(); |
e4976bb0 |
1008 | if ((p = getenv("NOIP_DEBUG")) && atoi(p)) |
1009 | debug = 1; |
1010 | get_local_ipaddrs(); |
1011 | readconfig(); |
3ef1fec9 |
1012 | create_sockdir(); |
e4976bb0 |
1013 | cleanup_sockdir(); |
1014 | }); |
1015 | } |