Commit | Line | Data |
---|---|---|
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; | |
9f82ba1f | 209 | |
e4976bb0 | 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)) | |
9f82ba1f | 511 | |
e4976bb0 | 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 | ||
9f82ba1f | 744 | if (sa->sa_family == AF_INET) { |
e4976bb0 | 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; | |
53390eff MW |
762 | int fixup_p = 0; |
763 | int rc; | |
e4976bb0 | 764 | |
765 | if (sa->sa_family == AF_INET) { | |
766 | PRESERVING_ERRNO({ | |
767 | do_implicit_bind(sk, &sa, &len, &sun); | |
53390eff | 768 | fixup_p = 1; |
e4976bb0 | 769 | }); |
770 | } | |
53390eff MW |
771 | rc = real_connect(sk, sa, len); |
772 | if (rc < 0) { | |
773 | switch (errno) { | |
774 | case ENOENT: errno = ECONNREFUSED; break; | |
775 | } | |
776 | } | |
777 | return rc; | |
e4976bb0 | 778 | } |
779 | ||
780 | ssize_t sendto(int sk, const void *buf, size_t len, int flags, | |
781 | const struct sockaddr *to, socklen_t tolen) | |
782 | { | |
783 | struct sockaddr_un sun; | |
784 | ||
785 | if (to && to->sa_family == AF_INET) { | |
786 | PRESERVING_ERRNO({ | |
787 | do_implicit_bind(sk, &to, &tolen, &sun); | |
788 | }); | |
789 | } | |
790 | return real_sendto(sk, buf, len, flags, to, tolen); | |
791 | } | |
792 | ||
793 | ssize_t recvfrom(int sk, void *buf, size_t len, int flags, | |
794 | struct sockaddr *from, socklen_t *fromlen) | |
795 | { | |
796 | char sabuf[1024]; | |
797 | socklen_t mylen = sizeof(sabuf); | |
798 | ssize_t n; | |
799 | ||
800 | if (!from) | |
801 | return real_recvfrom(sk, buf, len, flags, 0, 0); | |
802 | PRESERVING_ERRNO({ | |
803 | n = real_recvfrom(sk, buf, len, flags, SA(sabuf), &mylen); | |
804 | if (n < 0) | |
805 | return (-1); | |
806 | return_fake_name(SA(sabuf), mylen, from, fromlen); | |
807 | }); | |
808 | return (n); | |
809 | } | |
810 | ||
811 | ssize_t sendmsg(int sk, const struct msghdr *msg, int flags) | |
812 | { | |
813 | struct sockaddr_un sun; | |
814 | const struct sockaddr *sa; | |
815 | struct msghdr mymsg; | |
816 | ||
817 | if (msg->msg_name && SA(msg->msg_name)->sa_family == AF_INET) { | |
818 | PRESERVING_ERRNO({ | |
819 | sa = SA(msg->msg_name); | |
820 | mymsg = *msg; | |
821 | do_implicit_bind(sk, &sa, &mymsg.msg_namelen, &sun); | |
822 | mymsg.msg_name = SA(sa); | |
823 | msg = &mymsg; | |
824 | }); | |
825 | } | |
826 | return real_sendmsg(sk, msg, flags); | |
827 | } | |
828 | ||
829 | ssize_t recvmsg(int sk, struct msghdr *msg, int flags) | |
830 | { | |
831 | char sabuf[1024]; | |
832 | struct sockaddr *sa; | |
833 | socklen_t len; | |
834 | ssize_t n; | |
835 | ||
836 | if (!msg->msg_name) | |
837 | return real_recvmsg(sk, msg, flags); | |
838 | PRESERVING_ERRNO({ | |
839 | sa = SA(msg->msg_name); | |
840 | len = msg->msg_namelen; | |
841 | msg->msg_name = sabuf; | |
842 | msg->msg_namelen = sizeof(sabuf); | |
843 | n = real_recvmsg(sk, msg, flags); | |
844 | if (n < 0) | |
845 | return (-1); | |
846 | return_fake_name(SA(sabuf), msg->msg_namelen, sa, &len); | |
847 | msg->msg_name = sa; | |
848 | msg->msg_namelen = len; | |
849 | }); | |
850 | return (n); | |
851 | } | |
852 | ||
853 | int accept(int sk, struct sockaddr *sa, socklen_t *len) | |
854 | { | |
855 | char sabuf[1024]; | |
856 | socklen_t mylen = sizeof(sabuf); | |
857 | int nsk = real_accept(sk, SA(sabuf), &mylen); | |
858 | ||
859 | if (nsk < 0) | |
860 | return (-1); | |
861 | return_fake_name(SA(sabuf), mylen, sa, len); | |
862 | return (nsk); | |
863 | } | |
864 | ||
865 | int getsockname(int sk, struct sockaddr *sa, socklen_t *len) | |
866 | { | |
867 | PRESERVING_ERRNO({ | |
868 | char sabuf[1024]; | |
869 | socklen_t mylen = sizeof(sabuf); | |
870 | if (real_getsockname(sk, SA(sabuf), &mylen)) | |
871 | return (-1); | |
872 | return_fake_name(SA(sabuf), mylen, sa, len); | |
873 | }); | |
874 | return (0); | |
875 | } | |
876 | ||
877 | int getpeername(int sk, struct sockaddr *sa, socklen_t *len) | |
878 | { | |
879 | PRESERVING_ERRNO({ | |
880 | char sabuf[1024]; | |
881 | socklen_t mylen = sizeof(sabuf); | |
882 | if (real_getpeername(sk, SA(sabuf), &mylen)) | |
883 | return (-1); | |
884 | return_fake_name(SA(sabuf), mylen, sa, len); | |
885 | }); | |
886 | return (0); | |
887 | } | |
888 | ||
889 | int getsockopt(int sk, int lev, int opt, void *p, socklen_t *len) | |
890 | { | |
891 | switch (lev) { | |
892 | case SOL_IP: | |
893 | case SOL_TCP: | |
894 | case SOL_UDP: | |
895 | if (*len > 0) | |
896 | memset(p, 0, *len); | |
897 | return (0); | |
898 | } | |
899 | return real_getsockopt(sk, lev, opt, p, len); | |
900 | } | |
901 | ||
902 | int setsockopt(int sk, int lev, int opt, const void *p, socklen_t len) | |
903 | { | |
904 | switch (lev) { | |
905 | case SOL_IP: | |
906 | case SOL_TCP: | |
907 | case SOL_UDP: | |
908 | return (0); | |
909 | } | |
910 | switch (opt) { | |
911 | case SO_BINDTODEVICE: | |
912 | case SO_ATTACH_FILTER: | |
913 | case SO_DETACH_FILTER: | |
914 | return (0); | |
915 | } | |
916 | return real_setsockopt(sk, lev, opt, p, len); | |
917 | } | |
918 | ||
919 | /* --- Initialization --- */ | |
920 | ||
921 | static void cleanup_sockdir(void) | |
922 | { | |
923 | DIR *dir; | |
924 | struct dirent *d; | |
3ef1fec9 | 925 | struct sockaddr_in sin; |
e4976bb0 | 926 | struct sockaddr_un sun; |
3ef1fec9 | 927 | struct stat st; |
e4976bb0 | 928 | |
929 | if ((dir = opendir(sockdir)) == 0) | |
930 | return; | |
4ab301de | 931 | sun.sun_family = AF_UNIX; |
e4976bb0 | 932 | while ((d = readdir(dir)) != 0) { |
933 | if (d->d_name[0] == '.') continue; | |
934 | snprintf(sun.sun_path, sizeof(sun.sun_path), | |
935 | "%s/%s", sockdir, d->d_name); | |
3ef1fec9 | 936 | if (decode_inet_addr(&sin, &sun, SUN_LEN(&sun)) || |
937 | stat(sun.sun_path, &st) || | |
4ab301de | 938 | !S_ISSOCK(st.st_mode)) { |
939 | D( fprintf(stderr, "noip: ignoring unknown socketdir entry `%s'\n", | |
940 | sun.sun_path); ) | |
3ef1fec9 | 941 | continue; |
4ab301de | 942 | } |
e4976bb0 | 943 | if (unix_socket_status(&sun, 0) == STALE) { |
944 | D( fprintf(stderr, "noip: clearing away stale socket %s\n", | |
945 | d->d_name); ) | |
946 | unlink(sun.sun_path); | |
947 | } | |
948 | } | |
949 | closedir(dir); | |
950 | } | |
951 | ||
952 | static void get_local_ipaddrs(void) | |
953 | { | |
954 | struct if_nameindex *ifn; | |
955 | struct ifreq ifr; | |
956 | int sk; | |
957 | int i; | |
958 | ||
959 | ifn = if_nameindex(); | |
960 | if ((sk = real_socket(PF_INET, SOCK_STREAM, 00)) < 0) | |
961 | return; | |
962 | for (i = n_local_ipaddrs = 0; | |
963 | n_local_ipaddrs < MAX_LOCAL_IPADDRS && | |
964 | ifn[i].if_name && *ifn[i].if_name; | |
965 | i++) { | |
966 | strcpy(ifr.ifr_name, ifn[i].if_name); | |
967 | if (ioctl(sk, SIOCGIFADDR, &ifr) || ifr.ifr_addr.sa_family != AF_INET) | |
968 | continue; | |
969 | local_ipaddrs[n_local_ipaddrs++] = | |
970 | SIN(&ifr.ifr_addr)->sin_addr; | |
971 | D( fprintf(stderr, "noip: local addr %s = %s\n", ifn[i].if_name, | |
972 | inet_ntoa(local_ipaddrs[n_local_ipaddrs - 1])); ) | |
973 | } | |
974 | close(sk); | |
975 | } | |
976 | ||
3ef1fec9 | 977 | static void printerr(const char *p) { write(STDERR_FILENO, p, strlen(p)); } |
978 | ||
979 | static void create_sockdir(void) | |
980 | { | |
981 | struct stat st; | |
982 | ||
983 | if (stat(sockdir, &st)) { | |
984 | if (errno == ENOENT) { | |
985 | if (mkdir(sockdir, 0700)) { | |
986 | perror("noip: creating socketdir"); | |
987 | exit(127); | |
988 | } | |
989 | if (!stat(sockdir, &st)) | |
990 | goto check; | |
991 | } | |
992 | perror("noip: checking socketdir"); | |
993 | exit(127); | |
994 | } | |
995 | check: | |
996 | if (!S_ISDIR(st.st_mode)) { | |
997 | printerr("noip: bad socketdir: not a directory\n"); | |
998 | exit(127); | |
999 | } | |
1000 | if (st.st_uid != uid) { | |
1001 | printerr("noip: bad socketdir: not owner\n"); | |
1002 | exit(127); | |
1003 | } | |
1004 | if (st.st_mode & 077) { | |
1005 | printerr("noip: bad socketdir: not private\n"); | |
1006 | exit(127); | |
1007 | } | |
1008 | } | |
1009 | ||
e4976bb0 | 1010 | static void setup(void) |
1011 | { | |
1012 | PRESERVING_ERRNO({ | |
1013 | char *p; | |
1014 | ||
1015 | import(); | |
3ef1fec9 | 1016 | uid = geteuid(); |
e4976bb0 | 1017 | if ((p = getenv("NOIP_DEBUG")) && atoi(p)) |
1018 | debug = 1; | |
1019 | get_local_ipaddrs(); | |
1020 | readconfig(); | |
3ef1fec9 | 1021 | create_sockdir(); |
e4976bb0 | 1022 | cleanup_sockdir(); |
1023 | }); | |
1024 | } |