Commit | Line | Data |
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1d1ccf4f MW |
1 | /* -*-c-*- |
2 | * | |
3 | * Make programs use Unix-domain sockets instead of IP | |
4 | * | |
5 | * (c) 2008 Straylight/Edgeware | |
6 | */ | |
7 | ||
8 | /*----- Licensing notice --------------------------------------------------* | |
9 | * | |
10 | * This file is part of the preload-hacks package. | |
11 | * | |
12 | * Preload-hacks are free software; you can redistribute it and/or modify | |
13 | * them under the terms of the GNU General Public License as published by | |
14 | * the Free Software Foundation; either version 2 of the License, or (at | |
15 | * your option) any later version. | |
16 | * | |
de6df72d MW |
17 | * Preload-hacks are distributed in the hope that it will be useful, but |
18 | * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
19 | * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
20 | * for more details. | |
1d1ccf4f MW |
21 | * |
22 | * You should have received a copy of the GNU General Public License along | |
de6df72d MW |
23 | * with preload-hacks; if not, write to the Free Software Foundation, Inc., |
24 | * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
1d1ccf4f MW |
25 | */ |
26 | ||
e4976bb0 | 27 | #define _GNU_SOURCE |
28 | #undef sun | |
29 | #undef SUN | |
30 | #define DEBUG | |
31 | ||
1d1ccf4f MW |
32 | /*----- Header files ------------------------------------------------------*/ |
33 | ||
9314b85a | 34 | #include <assert.h> |
e4976bb0 | 35 | #include <ctype.h> |
36 | #include <errno.h> | |
658c1774 | 37 | #include <stdarg.h> |
9314b85a | 38 | #include <stddef.h> |
e4976bb0 | 39 | #include <stdio.h> |
40 | #include <stdlib.h> | |
41 | ||
42 | #include <unistd.h> | |
43 | #include <dirent.h> | |
44 | #include <dlfcn.h> | |
45 | #include <fcntl.h> | |
46 | #include <pwd.h> | |
47 | ||
48 | #include <sys/ioctl.h> | |
49 | #include <sys/socket.h> | |
50 | #include <sys/stat.h> | |
51 | #include <sys/un.h> | |
52 | ||
53 | #include <netinet/in.h> | |
54 | #include <arpa/inet.h> | |
55 | #include <netinet/tcp.h> | |
56 | #include <netinet/udp.h> | |
9f1396d9 | 57 | #include <ifaddrs.h> |
9314b85a | 58 | #include <netdb.h> |
e4976bb0 | 59 | |
1d1ccf4f MW |
60 | /*----- Data structures ---------------------------------------------------*/ |
61 | ||
62 | enum { UNUSED, STALE, USED }; /* Unix socket status values */ | |
63 | enum { WANT_FRESH, WANT_EXISTING }; /* Socket address dispositions */ | |
64 | enum { DENY, ALLOW }; /* ACL verdicts */ | |
65 | ||
2a06ea0b | 66 | static int address_families[] = { AF_INET, AF_INET6, -1 }; |
9314b85a MW |
67 | |
68 | #define ADDRBUFSZ 64 | |
69 | ||
70 | /* Address representations. */ | |
71 | typedef union ipaddr { | |
72 | struct in_addr v4; | |
2a06ea0b | 73 | struct in6_addr v6; |
9314b85a MW |
74 | } ipaddr; |
75 | ||
76 | /* Convenient socket address hacking. */ | |
77 | typedef union address { | |
78 | struct sockaddr sa; | |
79 | struct sockaddr_in sin; | |
2a06ea0b | 80 | struct sockaddr_in6 sin6; |
9314b85a MW |
81 | } address; |
82 | ||
1d1ccf4f | 83 | /* Access control list nodes */ |
e4976bb0 | 84 | typedef struct aclnode { |
85 | struct aclnode *next; | |
86 | int act; | |
9314b85a MW |
87 | int af; |
88 | ipaddr minaddr, maxaddr; | |
e4976bb0 | 89 | unsigned short minport, maxport; |
90 | } aclnode; | |
91 | ||
006dd63f MW |
92 | /* A type for an address range */ |
93 | typedef struct addrrange { | |
94 | int type; | |
95 | union { | |
96 | struct { int af; ipaddr min, max; } range; | |
97 | } u; | |
98 | } addrrange; | |
99 | enum { EMPTY, ANY, LOCAL, RANGE }; | |
100 | ||
1d1ccf4f | 101 | /* Local address records */ |
9314b85a MW |
102 | typedef struct full_ipaddr { |
103 | int af; | |
104 | ipaddr addr; | |
105 | } full_ipaddr; | |
2a06ea0b | 106 | #define MAX_LOCAL_IPADDRS 64 |
9314b85a | 107 | static full_ipaddr local_ipaddrs[MAX_LOCAL_IPADDRS]; |
e4976bb0 | 108 | static int n_local_ipaddrs; |
109 | ||
1d1ccf4f | 110 | /* General configuration */ |
e4976bb0 | 111 | static uid_t uid; |
112 | static char *sockdir = 0; | |
113 | static int debug = 0; | |
f6049fdd | 114 | static unsigned minautoport = 16384, maxautoport = 65536; |
e4976bb0 | 115 | |
1d1ccf4f | 116 | /* Access control lists */ |
e4976bb0 | 117 | static aclnode *bind_real, **bind_tail = &bind_real; |
118 | static aclnode *connect_real, **connect_tail = &connect_real; | |
119 | ||
1d1ccf4f | 120 | /*----- Import the real versions of functions -----------------------------*/ |
e4976bb0 | 121 | |
1d1ccf4f | 122 | /* The list of functions to immport. */ |
e4976bb0 | 123 | #define IMPORTS(_) \ |
124 | _(socket, int, (int, int, int)) \ | |
125 | _(socketpair, int, (int, int, int, int *)) \ | |
126 | _(connect, int, (int, const struct sockaddr *, socklen_t)) \ | |
127 | _(bind, int, (int, const struct sockaddr *, socklen_t)) \ | |
128 | _(accept, int, (int, struct sockaddr *, socklen_t *)) \ | |
129 | _(getsockname, int, (int, struct sockaddr *, socklen_t *)) \ | |
130 | _(getpeername, int, (int, struct sockaddr *, socklen_t *)) \ | |
131 | _(getsockopt, int, (int, int, int, void *, socklen_t *)) \ | |
132 | _(setsockopt, int, (int, int, int, const void *, socklen_t)) \ | |
133 | _(sendto, ssize_t, (int, const void *buf, size_t, int, \ | |
134 | const struct sockaddr *to, socklen_t tolen)) \ | |
135 | _(recvfrom, ssize_t, (int, void *buf, size_t, int, \ | |
7d769c69 | 136 | struct sockaddr *from, socklen_t *fromlen)) \ |
e4976bb0 | 137 | _(sendmsg, ssize_t, (int, const struct msghdr *, int)) \ |
658c1774 MW |
138 | _(recvmsg, ssize_t, (int, struct msghdr *, int)) \ |
139 | _(ioctl, int, (int, unsigned long, ...)) | |
e4976bb0 | 140 | |
1d1ccf4f | 141 | /* Function pointers to set up. */ |
e4976bb0 | 142 | #define DECL(imp, ret, args) static ret (*real_##imp) args; |
143 | IMPORTS(DECL) | |
144 | #undef DECL | |
145 | ||
1d1ccf4f | 146 | /* Import the system calls. */ |
e4976bb0 | 147 | static void import(void) |
148 | { | |
149 | #define IMPORT(imp, ret, args) \ | |
150 | real_##imp = (ret (*)args)dlsym(RTLD_NEXT, #imp); | |
151 | IMPORTS(IMPORT) | |
152 | #undef IMPORT | |
153 | } | |
154 | ||
1d1ccf4f | 155 | /*----- Utilities ---------------------------------------------------------*/ |
e4976bb0 | 156 | |
1d1ccf4f | 157 | /* Socket address casts */ |
e4976bb0 | 158 | #define SA(sa) ((struct sockaddr *)(sa)) |
159 | #define SIN(sa) ((struct sockaddr_in *)(sa)) | |
2a06ea0b | 160 | #define SIN6(sa) ((struct sockaddr_in6 *)(sa)) |
e4976bb0 | 161 | #define SUN(sa) ((struct sockaddr_un *)(sa)) |
162 | ||
1d1ccf4f | 163 | /* Raw bytes */ |
e4976bb0 | 164 | #define UC(ch) ((unsigned char)(ch)) |
165 | ||
1d1ccf4f | 166 | /* Memory allocation */ |
e4976bb0 | 167 | #define NEW(x) ((x) = xmalloc(sizeof(*x))) |
168 | #define NEWV(x, n) ((x) = xmalloc(sizeof(*x) * (n))) | |
169 | ||
1d1ccf4f | 170 | /* Debugging */ |
e4976bb0 | 171 | #ifdef DEBUG |
172 | # define D(body) { if (debug) { body } } | |
e397f0bd | 173 | # define Dpid pid_t pid = debug ? getpid() : -1 |
e4976bb0 | 174 | #else |
175 | # define D(body) ; | |
e397f0bd | 176 | # define Dpid |
e4976bb0 | 177 | #endif |
178 | ||
1d1ccf4f | 179 | /* Preservation of error status */ |
e4976bb0 | 180 | #define PRESERVING_ERRNO(body) do { \ |
181 | int _err = errno; { body } errno = _err; \ | |
182 | } while (0) | |
183 | ||
1d1ccf4f | 184 | /* Allocate N bytes of memory; abort on failure. */ |
e4976bb0 | 185 | static void *xmalloc(size_t n) |
186 | { | |
187 | void *p; | |
188 | if (!n) return (0); | |
3ef1fec9 | 189 | if ((p = malloc(n)) == 0) { perror("malloc"); exit(127); } |
e4976bb0 | 190 | return (p); |
191 | } | |
192 | ||
1d1ccf4f | 193 | /* Allocate a copy of the null-terminated string P; abort on failure. */ |
e4976bb0 | 194 | static char *xstrdup(const char *p) |
195 | { | |
196 | size_t n = strlen(p) + 1; | |
197 | char *q = xmalloc(n); | |
198 | memcpy(q, p, n); | |
199 | return (q); | |
200 | } | |
9314b85a MW |
201 | |
202 | /*----- Address-type hacking ----------------------------------------------*/ | |
203 | ||
204 | /* If M is a simple mask, i.e., consists of a sequence of zero bits followed | |
205 | * by a sequence of one bits, then return the length of the latter sequence | |
206 | * (which may be zero); otherwise return -1. | |
207 | */ | |
208 | static int simple_mask_length(unsigned long m) | |
209 | { | |
210 | int n = 0; | |
211 | ||
212 | while (m & 1) { n++; m >>= 1; } | |
213 | return (m ? -1 : n); | |
214 | } | |
215 | ||
216 | /* Answer whether AF is an interesting address family. */ | |
217 | static int family_known_p(int af) | |
218 | { | |
219 | switch (af) { | |
220 | case AF_INET: | |
2a06ea0b | 221 | case AF_INET6: |
9314b85a MW |
222 | return (1); |
223 | default: | |
224 | return (0); | |
225 | } | |
226 | } | |
227 | ||
228 | /* Return the socket address length for address family AF. */ | |
229 | static socklen_t family_socklen(int af) | |
230 | { | |
231 | switch (af) { | |
232 | case AF_INET: return (sizeof(struct sockaddr_in)); | |
2a06ea0b | 233 | case AF_INET6: return (sizeof(struct sockaddr_in6)); |
9314b85a MW |
234 | default: abort(); |
235 | } | |
236 | } | |
237 | ||
238 | /* Return the width of addresses of kind AF. */ | |
239 | static int address_width(int af) | |
240 | { | |
241 | switch (af) { | |
242 | case AF_INET: return 32; | |
2a06ea0b | 243 | case AF_INET6: return 128; |
9314b85a MW |
244 | default: abort(); |
245 | } | |
246 | } | |
247 | ||
248 | /* If addresses A and B share a common prefix then return its length; | |
249 | * otherwise return -1. | |
250 | */ | |
251 | static int common_prefix_length(int af, const ipaddr *a, const ipaddr *b) | |
252 | { | |
253 | switch (af) { | |
254 | case AF_INET: { | |
255 | unsigned long aa = ntohl(a->v4.s_addr), bb = ntohl(b->v4.s_addr); | |
256 | unsigned long m = aa^bb; | |
257 | if ((aa&m) == 0 && (bb&m) == m) return (32 - simple_mask_length(m)); | |
258 | else return (-1); | |
259 | } break; | |
2a06ea0b MW |
260 | case AF_INET6: { |
261 | const uint8_t *aa = a->v6.s6_addr, *bb = b->v6.s6_addr; | |
262 | unsigned m; | |
263 | unsigned n; | |
264 | int i; | |
265 | ||
266 | for (i = 0; i < 16 && aa[i] == bb[i]; i++); | |
267 | n = 8*i; | |
268 | if (i < 16) { | |
269 | m = aa[i]^bb[i]; | |
270 | if ((aa[i]&m) != 0 || (bb[i]&m) != m) return (-1); | |
271 | n += 8 - simple_mask_length(m); | |
272 | for (i++; i < 16; i++) | |
273 | if (aa[i] || bb[i] != 0xff) return (-1); | |
274 | } | |
275 | return (n); | |
276 | } break; | |
9314b85a MW |
277 | default: |
278 | abort(); | |
279 | } | |
280 | } | |
281 | ||
282 | /* Extract the port number (in host byte-order) from SA. */ | |
283 | static int port_from_sockaddr(const struct sockaddr *sa) | |
284 | { | |
285 | switch (sa->sa_family) { | |
286 | case AF_INET: return (ntohs(SIN(sa)->sin_port)); | |
2a06ea0b | 287 | case AF_INET6: return (ntohs(SIN6(sa)->sin6_port)); |
9314b85a MW |
288 | default: abort(); |
289 | } | |
290 | } | |
291 | ||
292 | /* Store the port number PORT (in host byte-order) in SA. */ | |
293 | static void port_to_sockaddr(struct sockaddr *sa, int port) | |
294 | { | |
295 | switch (sa->sa_family) { | |
296 | case AF_INET: SIN(sa)->sin_port = htons(port); break; | |
2a06ea0b | 297 | case AF_INET6: SIN6(sa)->sin6_port = htons(port); break; |
9314b85a MW |
298 | default: abort(); |
299 | } | |
300 | } | |
10cee633 | 301 | |
9314b85a MW |
302 | /* Extract the address part from SA and store it in A. */ |
303 | static void ipaddr_from_sockaddr(ipaddr *a, const struct sockaddr *sa) | |
304 | { | |
305 | switch (sa->sa_family) { | |
306 | case AF_INET: a->v4 = SIN(sa)->sin_addr; break; | |
2a06ea0b | 307 | case AF_INET6: a->v6 = SIN6(sa)->sin6_addr; break; |
9314b85a MW |
308 | default: abort(); |
309 | } | |
310 | } | |
311 | ||
312 | /* Copy a whole socket address about. */ | |
313 | static void copy_sockaddr(struct sockaddr *sa_dst, | |
314 | const struct sockaddr *sa_src) | |
315 | { memcpy(sa_dst, sa_src, family_socklen(sa_src->sa_family)); } | |
316 | ||
317 | /* Answer whether two addresses are equal. */ | |
318 | static int ipaddr_equal_p(int af, const ipaddr *a, const ipaddr *b) | |
319 | { | |
320 | switch (af) { | |
321 | case AF_INET: return (a->v4.s_addr == b->v4.s_addr); | |
2a06ea0b | 322 | case AF_INET6: return (memcmp(a->v6.s6_addr, b->v6.s6_addr, 16) == 0); |
9314b85a MW |
323 | default: abort(); |
324 | } | |
325 | } | |
326 | ||
327 | /* Answer whether the address part of SA is between A and B (inclusive). We | |
328 | * assume that SA has the correct address family. | |
329 | */ | |
330 | static int sockaddr_in_range_p(const struct sockaddr *sa, | |
331 | const ipaddr *a, const ipaddr *b) | |
332 | { | |
333 | switch (sa->sa_family) { | |
334 | case AF_INET: { | |
335 | unsigned long addr = ntohl(SIN(sa)->sin_addr.s_addr); | |
336 | return (ntohl(a->v4.s_addr) <= addr && | |
337 | addr <= ntohl(b->v4.s_addr)); | |
338 | } break; | |
2a06ea0b MW |
339 | case AF_INET6: { |
340 | const uint8_t *ss = SIN6(sa)->sin6_addr.s6_addr; | |
341 | const uint8_t *aa = a->v6.s6_addr, *bb = b->v6.s6_addr; | |
342 | int h = 1, l = 1; | |
343 | int i; | |
344 | ||
345 | for (i = 0; h && l && i < 16; i++, ss++, aa++, bb++) { | |
346 | if (*ss < *aa || *bb < *ss) return (0); | |
347 | if (*aa < *ss) l = 0; | |
348 | if (*ss < *bb) h = 0; | |
349 | } | |
350 | return (1); | |
351 | } break; | |
9314b85a MW |
352 | default: |
353 | abort(); | |
354 | } | |
355 | } | |
356 | ||
357 | /* Fill in SA with the appropriate wildcard address. */ | |
358 | static void wildcard_address(int af, struct sockaddr *sa) | |
359 | { | |
360 | switch (af) { | |
361 | case AF_INET: { | |
362 | struct sockaddr_in *sin = SIN(sa); | |
363 | memset(sin, 0, sizeof(*sin)); | |
364 | sin->sin_family = AF_INET; | |
365 | sin->sin_port = 0; | |
366 | sin->sin_addr.s_addr = INADDR_ANY; | |
367 | } break; | |
2a06ea0b MW |
368 | case AF_INET6: { |
369 | struct sockaddr_in6 *sin6 = SIN6(sa); | |
dc2b0a44 | 370 | memset(sin6, 0, sizeof(*sin6)); |
2a06ea0b MW |
371 | sin6->sin6_family = AF_INET6; |
372 | sin6->sin6_port = 0; | |
373 | sin6->sin6_addr = in6addr_any; | |
374 | sin6->sin6_scope_id = 0; | |
375 | sin6->sin6_flowinfo = 0; | |
376 | } break; | |
9314b85a MW |
377 | default: |
378 | abort(); | |
379 | } | |
380 | } | |
381 | ||
382 | /* Mask the address A, forcing all but the top PLEN bits to zero or one | |
383 | * according to HIGHP. | |
384 | */ | |
385 | static void mask_address(int af, ipaddr *a, int plen, int highp) | |
386 | { | |
387 | switch (af) { | |
388 | case AF_INET: { | |
389 | unsigned long addr = ntohl(a->v4.s_addr); | |
390 | unsigned long mask = plen ? ~0ul << (32 - plen) : 0; | |
391 | addr &= mask; | |
392 | if (highp) addr |= ~mask; | |
393 | a->v4.s_addr = htonl(addr & 0xffffffff); | |
394 | } break; | |
2a06ea0b MW |
395 | case AF_INET6: { |
396 | int i = plen/8; | |
397 | unsigned m = (0xff << (8 - plen%8)) & 0xff; | |
398 | unsigned s = highp ? 0xff : 0; | |
399 | if (m) { | |
400 | a->v6.s6_addr[i] = (a->v6.s6_addr[i] & m) | (s & ~m); | |
401 | i++; | |
402 | } | |
403 | for (; i < 16; i++) a->v6.s6_addr[i] = s; | |
404 | } break; | |
9314b85a MW |
405 | default: |
406 | abort(); | |
407 | } | |
408 | } | |
409 | ||
410 | /* Write a presentation form of SA to BUF, a buffer of length SZ. LEN is the | |
411 | * address length; if it's zero, look it up based on the address family. | |
412 | * Return a pointer to the string (which might, in an emergency, be a static | |
413 | * string rather than your buffer). | |
414 | */ | |
415 | static char *present_sockaddr(const struct sockaddr *sa, socklen_t len, | |
416 | char *buf, size_t sz) | |
417 | { | |
418 | #define WANT(n_) do { if (sz < (n_)) goto nospace; } while (0) | |
419 | #define PUTC(c_) do { *buf++ = (c_); sz--; } while (0) | |
420 | ||
ad0f7002 | 421 | if (!sa) return "<null-address>"; |
9314b85a MW |
422 | if (!sz) return "<no-space-in-buffer>"; |
423 | if (!len) len = family_socklen(sa->sa_family); | |
424 | ||
425 | switch (sa->sa_family) { | |
426 | case AF_UNIX: { | |
427 | struct sockaddr_un *sun = SUN(sa); | |
428 | char *p = sun->sun_path; | |
429 | size_t n = len - offsetof(struct sockaddr_un, sun_path); | |
430 | ||
431 | assert(n); | |
432 | if (*p == 0) { | |
433 | WANT(1); PUTC('@'); | |
434 | p++; n--; | |
435 | while (n) { | |
436 | switch (*p) { | |
437 | case 0: WANT(2); PUTC('\\'); PUTC('0'); break; | |
438 | case '\a': WANT(2); PUTC('\\'); PUTC('a'); break; | |
439 | case '\n': WANT(2); PUTC('\\'); PUTC('n'); break; | |
440 | case '\r': WANT(2); PUTC('\\'); PUTC('r'); break; | |
441 | case '\t': WANT(2); PUTC('\\'); PUTC('t'); break; | |
442 | case '\v': WANT(2); PUTC('\\'); PUTC('v'); break; | |
443 | case '\\': WANT(2); PUTC('\\'); PUTC('\\'); break; | |
444 | default: | |
445 | if (*p > ' ' && *p <= '~') | |
446 | { WANT(1); PUTC(*p); } | |
447 | else { | |
448 | WANT(4); PUTC('\\'); PUTC('x'); | |
449 | PUTC((*p >> 4)&0xf); PUTC((*p >> 0)&0xf); | |
450 | } | |
451 | break; | |
452 | } | |
453 | p++; n--; | |
454 | } | |
455 | } else { | |
456 | if (*p != '/') { WANT(2); PUTC('.'); PUTC('/'); } | |
457 | while (n && *p) { WANT(1); PUTC(*p); p++; n--; } | |
458 | } | |
459 | WANT(1); PUTC(0); | |
460 | } break; | |
2a06ea0b | 461 | case AF_INET: case AF_INET6: { |
9314b85a MW |
462 | char addrbuf[NI_MAXHOST], portbuf[NI_MAXSERV]; |
463 | int err = getnameinfo(sa, len, | |
464 | addrbuf, sizeof(addrbuf), | |
465 | portbuf, sizeof(portbuf), | |
466 | NI_NUMERICHOST | NI_NUMERICSERV); | |
467 | assert(!err); | |
468 | snprintf(buf, sz, strchr(addrbuf, ':') ? "[%s]:%s" : "%s:%s", | |
469 | addrbuf, portbuf); | |
470 | } break; | |
471 | default: | |
472 | snprintf(buf, sz, "<unknown-address-family %d>", sa->sa_family); | |
473 | break; | |
474 | } | |
475 | return (buf); | |
476 | ||
477 | nospace: | |
478 | buf[sz - 1] = 0; | |
479 | return (buf); | |
480 | } | |
481 | ||
482 | /* Guess the family of a textual socket address. */ | |
483 | static int guess_address_family(const char *p) | |
2a06ea0b | 484 | { return (strchr(p, ':') ? AF_INET6 : AF_INET); } |
9314b85a MW |
485 | |
486 | /* Parse a socket address P and write the result to SA. */ | |
487 | static int parse_sockaddr(struct sockaddr *sa, const char *p) | |
488 | { | |
489 | char buf[ADDRBUFSZ]; | |
490 | char *q; | |
491 | struct addrinfo *ai, ai_hint = { 0 }; | |
492 | ||
493 | if (strlen(p) >= sizeof(buf) - 1) return (-1); | |
494 | strcpy(buf, p); p = buf; | |
495 | if (*p != '[') { | |
496 | if ((q = strchr(p, ':')) == 0) return (-1); | |
497 | *q++ = 0; | |
498 | } else { | |
499 | p++; | |
500 | if ((q = strchr(p, ']')) == 0) return (-1); | |
501 | *q++ = 0; | |
502 | if (*q != ':') return (-1); | |
503 | q++; | |
504 | } | |
505 | ||
506 | ai_hint.ai_family = AF_UNSPEC; | |
507 | ai_hint.ai_socktype = SOCK_DGRAM; | |
508 | ai_hint.ai_flags = AI_NUMERICHOST | AI_NUMERICSERV; | |
509 | if (getaddrinfo(p, q, &ai_hint, &ai)) return (-1); | |
510 | memcpy(sa, ai->ai_addr, ai->ai_addrlen); | |
511 | freeaddrinfo(ai); | |
512 | return (0); | |
513 | } | |
514 | ||
1d1ccf4f | 515 | /*----- Access control lists ----------------------------------------------*/ |
e4976bb0 | 516 | |
517 | #ifdef DEBUG | |
518 | ||
006dd63f | 519 | static void dump_addrrange(int af, const ipaddr *min, const ipaddr *max) |
e4976bb0 | 520 | { |
9314b85a MW |
521 | char buf[ADDRBUFSZ]; |
522 | const char *p; | |
523 | int plen; | |
e4976bb0 | 524 | |
006dd63f MW |
525 | plen = common_prefix_length(af, min, max); |
526 | p = inet_ntop(af, min, buf, sizeof(buf)); | |
9314b85a MW |
527 | fprintf(stderr, strchr(p, ':') ? "[%s]" : "%s", p); |
528 | if (plen < 0) { | |
006dd63f | 529 | p = inet_ntop(af, &max, buf, sizeof(buf)); |
9314b85a | 530 | fprintf(stderr, strchr(p, ':') ? "-[%s]" : "-%s", p); |
006dd63f | 531 | } else if (plen < address_width(af)) |
9314b85a | 532 | fprintf(stderr, "/%d", plen); |
006dd63f MW |
533 | } |
534 | ||
535 | /* Write to standard error a description of the ACL node A. */ | |
536 | static void dump_aclnode(const aclnode *a) | |
537 | { | |
538 | fprintf(stderr, "noip(%d): %c ", getpid(), a->act ? '+' : '-'); | |
539 | dump_addrrange(a->af, &a->minaddr, &a->maxaddr); | |
e4976bb0 | 540 | if (a->minport != 0 || a->maxport != 0xffff) { |
541 | fprintf(stderr, ":%u", (unsigned)a->minport); | |
542 | if (a->minport != a->maxport) | |
543 | fprintf(stderr, "-%u", (unsigned)a->maxport); | |
544 | } | |
545 | fputc('\n', stderr); | |
546 | } | |
547 | ||
bb182ccf | 548 | static void dump_acl(const aclnode *a) |
1d1ccf4f MW |
549 | { |
550 | int act = ALLOW; | |
551 | ||
552 | for (; a; a = a->next) { | |
553 | dump_aclnode(a); | |
554 | act = a->act; | |
555 | } | |
e397f0bd | 556 | fprintf(stderr, "noip(%d): [default policy: %s]\n", getpid(), |
1d1ccf4f MW |
557 | act == ALLOW ? "DENY" : "ALLOW"); |
558 | } | |
559 | ||
e4976bb0 | 560 | #endif |
561 | ||
9314b85a | 562 | /* Returns nonzero if the ACL A allows the socket address SA. */ |
bb182ccf | 563 | static int acl_allows_p(const aclnode *a, const struct sockaddr *sa) |
e4976bb0 | 564 | { |
9314b85a | 565 | unsigned short port = port_from_sockaddr(sa); |
e4976bb0 | 566 | int act = ALLOW; |
e397f0bd | 567 | Dpid; |
e4976bb0 | 568 | |
9314b85a | 569 | D({ char buf[ADDRBUFSZ]; |
e397f0bd | 570 | fprintf(stderr, "noip(%d): check %s\n", pid, |
9314b85a | 571 | present_sockaddr(sa, 0, buf, sizeof(buf))); }) |
e4976bb0 | 572 | for (; a; a = a->next) { |
573 | D( dump_aclnode(a); ) | |
9314b85a | 574 | if (sockaddr_in_range_p(sa, &a->minaddr, &a->maxaddr) && |
e4976bb0 | 575 | a->minport <= port && port <= a->maxport) { |
e397f0bd MW |
576 | D( fprintf(stderr, "noip(%d): aha! %s\n", pid, |
577 | a->act ? "ALLOW" : "DENY"); ) | |
e4976bb0 | 578 | return (a->act); |
579 | } | |
580 | act = a->act; | |
581 | } | |
e397f0bd MW |
582 | D( fprintf(stderr, "noip(%d): nothing found: %s\n", pid, |
583 | act ? "DENY" : "ALLOW"); ) | |
e4976bb0 | 584 | return (!act); |
585 | } | |
586 | ||
1d1ccf4f | 587 | /*----- Socket address conversion -----------------------------------------*/ |
e4976bb0 | 588 | |
1d1ccf4f | 589 | /* Return a uniformly distributed integer between MIN and MAX inclusive. */ |
f6049fdd | 590 | static unsigned randrange(unsigned min, unsigned max) |
591 | { | |
592 | unsigned mask, i; | |
593 | ||
594 | /* It's so nice not to have to care about the quality of the generator | |
9314b85a MW |
595 | * much! |
596 | */ | |
f6049fdd | 597 | max -= min; |
598 | for (mask = 1; mask < max; mask = (mask << 1) | 1) | |
599 | ; | |
600 | do i = rand() & mask; while (i > max); | |
601 | return (i + min); | |
602 | } | |
603 | ||
1d1ccf4f MW |
604 | /* Return the status of Unix-domain socket address SUN. Returns: UNUSED if |
605 | * the socket doesn't exist; USED if the path refers to an active socket, or | |
606 | * isn't really a socket at all, or we can't tell without a careful search | |
607 | * and QUICKP is set; or STALE if the file refers to a socket which isn't | |
608 | * being used any more. | |
609 | */ | |
610 | static int unix_socket_status(struct sockaddr_un *sun, int quickp) | |
611 | { | |
612 | struct stat st; | |
613 | FILE *fp = 0; | |
614 | size_t len, n; | |
615 | int rc; | |
616 | char buf[256]; | |
617 | ||
618 | if (stat(sun->sun_path, &st)) | |
619 | return (errno == ENOENT ? UNUSED : USED); | |
620 | if (!S_ISSOCK(st.st_mode) || quickp) | |
621 | return (USED); | |
622 | rc = USED; | |
623 | if ((fp = fopen("/proc/net/unix", "r")) == 0) | |
624 | goto done; | |
72d85cdb | 625 | if (!fgets(buf, sizeof(buf), fp)) goto done; /* skip header */ |
1d1ccf4f MW |
626 | len = strlen(sun->sun_path); |
627 | while (fgets(buf, sizeof(buf), fp)) { | |
628 | n = strlen(buf); | |
629 | if (n >= len + 2 && buf[n - len - 2] == ' ' && buf[n - 1] == '\n' && | |
630 | memcmp(buf + n - len - 1, sun->sun_path, len) == 0) | |
631 | goto done; | |
632 | } | |
633 | if (ferror(fp)) | |
634 | goto done; | |
635 | rc = STALE; | |
636 | done: | |
637 | if (fp) fclose(fp); | |
638 | return (rc); | |
639 | } | |
640 | ||
f6e0ea86 MW |
641 | /* Convert the IP address SA to a Unix-domain address SUN. Fail if the |
642 | * address seems already taken. If DESPARATEP then try cleaning up stale old | |
643 | * sockets. | |
644 | */ | |
645 | static int encode_unused_inet_addr(struct sockaddr *sa, | |
646 | struct sockaddr_un *sun, | |
647 | int desperatep) | |
648 | { | |
649 | address waddr; | |
650 | struct sockaddr_un wsun; | |
651 | int rc; | |
652 | char buf[ADDRBUFSZ]; | |
653 | ||
654 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir, | |
655 | present_sockaddr(sa, 0, buf, sizeof(buf))); | |
656 | if ((rc = unix_socket_status(sun, !desperatep)) == USED) return (-1); | |
657 | else if (rc == STALE) unlink(sun->sun_path); | |
658 | ||
659 | wildcard_address(sa->sa_family, &waddr.sa); | |
660 | port_to_sockaddr(&waddr.sa, port_from_sockaddr(sa)); | |
661 | snprintf(wsun.sun_path, sizeof(wsun.sun_path), "%s/%s", sockdir, | |
662 | present_sockaddr(&waddr.sa, 0, buf, sizeof(buf))); | |
663 | if ((rc = unix_socket_status(&wsun, !desperatep)) == USED) return (-1); | |
664 | else if (rc == STALE) unlink(wsun.sun_path); | |
665 | ||
666 | return (0); | |
667 | } | |
668 | ||
9314b85a MW |
669 | /* Encode the Internet address SA as a Unix-domain address SUN. If WANT is |
670 | * WANT_FRESH, and SA's port number is zero, then we pick an arbitrary local | |
1d1ccf4f | 671 | * port. Otherwise we pick the port given. There's an unpleasant hack to |
9314b85a MW |
672 | * find servers bound to local wildcard addresses. Returns zero on success; |
673 | * -1 on failure. | |
1d1ccf4f | 674 | */ |
e4976bb0 | 675 | static int encode_inet_addr(struct sockaddr_un *sun, |
9314b85a | 676 | const struct sockaddr *sa, |
e4976bb0 | 677 | int want) |
678 | { | |
679 | int i; | |
3ef1fec9 | 680 | int desperatep = 0; |
9314b85a MW |
681 | address addr; |
682 | char buf[ADDRBUFSZ]; | |
e4976bb0 | 683 | int rc; |
684 | ||
e397f0bd | 685 | D( fprintf(stderr, "noip(%d): encode %s (%s)", getpid(), |
9314b85a | 686 | present_sockaddr(sa, 0, buf, sizeof(buf)), |
e4976bb0 | 687 | want == WANT_EXISTING ? "EXISTING" : "FRESH"); ) |
688 | sun->sun_family = AF_UNIX; | |
9314b85a MW |
689 | if (port_from_sockaddr(sa) || want == WANT_EXISTING) { |
690 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir, | |
691 | present_sockaddr(sa, 0, buf, sizeof(buf))); | |
e4976bb0 | 692 | rc = unix_socket_status(sun, 0); |
693 | if (rc == STALE) unlink(sun->sun_path); | |
694 | if (rc != USED && want == WANT_EXISTING) { | |
9314b85a MW |
695 | wildcard_address(sa->sa_family, &addr.sa); |
696 | port_to_sockaddr(&addr.sa, port_from_sockaddr(sa)); | |
697 | snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir, | |
698 | present_sockaddr(&addr.sa, 0, buf, sizeof(buf))); | |
e4976bb0 | 699 | if (unix_socket_status(sun, 0) == STALE) unlink(sun->sun_path); |
700 | } | |
701 | } else { | |
9314b85a | 702 | copy_sockaddr(&addr.sa, sa); |
f6049fdd | 703 | for (i = 0; i < 10; i++) { |
9314b85a | 704 | port_to_sockaddr(&addr.sa, randrange(minautoport, maxautoport)); |
f6e0ea86 | 705 | if (!encode_unused_inet_addr(&addr.sa, sun, 0)) goto found; |
f6049fdd | 706 | } |
3ef1fec9 | 707 | for (desperatep = 0; desperatep < 2; desperatep++) { |
f6049fdd | 708 | for (i = minautoport; i <= maxautoport; i++) { |
9314b85a | 709 | port_to_sockaddr(&addr.sa, i); |
f6e0ea86 | 710 | if (!encode_unused_inet_addr(&addr.sa, sun, 0)) goto found; |
e4976bb0 | 711 | } |
712 | } | |
713 | errno = EADDRINUSE; | |
714 | D( fprintf(stderr, " -- can't resolve\n"); ) | |
715 | return (-1); | |
716 | found:; | |
717 | } | |
718 | D( fprintf(stderr, " -> `%s'\n", sun->sun_path); ) | |
719 | return (0); | |
720 | } | |
721 | ||
9314b85a | 722 | /* Decode the Unix address SUN to an Internet address SIN. If AF_HINT is |
c0876c8c MW |
723 | * nonzero, an empty address (indicative of an unbound Unix-domain socket) is |
724 | * translated to a wildcard Internet address of the appropriate family. | |
725 | * Returns zero on success; -1 on failure (e.g., it wasn't one of our | |
726 | * addresses). | |
00a98a8a | 727 | */ |
9314b85a | 728 | static int decode_inet_addr(struct sockaddr *sa, int af_hint, |
e4976bb0 | 729 | const struct sockaddr_un *sun, |
9314b85a | 730 | socklen_t len) |
e4976bb0 | 731 | { |
9314b85a | 732 | char buf[ADDRBUFSZ]; |
a2114371 | 733 | size_t n = strlen(sockdir), nn; |
9314b85a | 734 | address addr; |
e4976bb0 | 735 | |
9314b85a MW |
736 | if (!sa) sa = &addr.sa; |
737 | if (sun->sun_family != AF_UNIX) return (-1); | |
738 | if (len > sizeof(*sun)) return (-1); | |
739 | ((char *)sun)[len] = 0; | |
a2114371 | 740 | nn = strlen(sun->sun_path); |
e397f0bd | 741 | D( fprintf(stderr, "noip(%d): decode `%s'", getpid(), sun->sun_path); ) |
9314b85a MW |
742 | if (af_hint && !sun->sun_path[0]) { |
743 | wildcard_address(af_hint, sa); | |
e4976bb0 | 744 | D( fprintf(stderr, " -- unbound socket\n"); ) |
745 | return (0); | |
746 | } | |
747 | if (nn < n + 1 || nn - n >= sizeof(buf) || sun->sun_path[n] != '/' || | |
748 | memcmp(sun->sun_path, sockdir, n) != 0) { | |
749 | D( fprintf(stderr, " -- not one of ours\n"); ) | |
750 | return (-1); | |
751 | } | |
9314b85a MW |
752 | if (parse_sockaddr(sa, sun->sun_path + n + 1)) return (-1); |
753 | D( fprintf(stderr, " -> %s\n", | |
754 | present_sockaddr(sa, 0, buf, sizeof(buf))); ) | |
e4976bb0 | 755 | return (0); |
756 | } | |
757 | ||
1d1ccf4f MW |
758 | /* SK is (or at least might be) a Unix-domain socket we created when an |
759 | * Internet socket was asked for. We've decided it should be an Internet | |
86134bfe MW |
760 | * socket after all, with family AF_HINT, so convert it. If TMP is not null, |
761 | * then don't replace the existing descriptor: store the new socket in *TMP | |
762 | * and return zero. | |
1d1ccf4f | 763 | */ |
86134bfe | 764 | static int fixup_real_ip_socket(int sk, int af_hint, int *tmp) |
e4976bb0 | 765 | { |
766 | int nsk; | |
767 | int type; | |
768 | int f, fd; | |
769 | struct sockaddr_un sun; | |
9314b85a | 770 | address addr; |
e4976bb0 | 771 | socklen_t len; |
772 | ||
773 | #define OPTS(_) \ | |
774 | _(DEBUG, int) \ | |
775 | _(REUSEADDR, int) \ | |
776 | _(DONTROUTE, int) \ | |
777 | _(BROADCAST, int) \ | |
778 | _(SNDBUF, int) \ | |
779 | _(RCVBUF, int) \ | |
780 | _(OOBINLINE, int) \ | |
781 | _(NO_CHECK, int) \ | |
782 | _(LINGER, struct linger) \ | |
783 | _(BSDCOMPAT, int) \ | |
784 | _(RCVLOWAT, int) \ | |
785 | _(RCVTIMEO, struct timeval) \ | |
786 | _(SNDTIMEO, struct timeval) | |
787 | ||
788 | len = sizeof(sun); | |
789 | if (real_getsockname(sk, SA(&sun), &len)) | |
790 | return (-1); | |
9314b85a | 791 | if (decode_inet_addr(&addr.sa, af_hint, &sun, len)) |
e4976bb0 | 792 | return (0); /* Not one of ours */ |
793 | len = sizeof(type); | |
794 | if (real_getsockopt(sk, SOL_SOCKET, SO_TYPE, &type, &len) < 0 || | |
9314b85a | 795 | (nsk = real_socket(addr.sa.sa_family, type, 0)) < 0) |
e4976bb0 | 796 | return (-1); |
797 | #define FIX(opt, ty) do { \ | |
798 | ty ov_; \ | |
799 | len = sizeof(ov_); \ | |
800 | if (real_getsockopt(sk, SOL_SOCKET, SO_##opt, &ov_, &len) < 0 || \ | |
801 | real_setsockopt(nsk, SOL_SOCKET, SO_##opt, &ov_, len)) { \ | |
9fb8e5c9 | 802 | close(nsk); \ |
e4976bb0 | 803 | return (-1); \ |
804 | } \ | |
805 | } while (0); | |
806 | OPTS(FIX) | |
807 | #undef FIX | |
86134bfe MW |
808 | if (tmp) |
809 | *tmp = nsk; | |
810 | else { | |
811 | if ((f = fcntl(sk, F_GETFL)) < 0 || | |
812 | (fd = fcntl(sk, F_GETFD)) < 0 || | |
813 | fcntl(nsk, F_SETFL, f) < 0 || | |
814 | dup2(nsk, sk) < 0) { | |
815 | close(nsk); | |
816 | return (-1); | |
817 | } | |
818 | unlink(sun.sun_path); | |
9fb8e5c9 | 819 | close(nsk); |
86134bfe MW |
820 | if (fcntl(sk, F_SETFD, fd) < 0) { |
821 | perror("noip: fixup_real_ip_socket F_SETFD"); | |
822 | abort(); | |
823 | } | |
e4976bb0 | 824 | } |
825 | return (0); | |
826 | } | |
827 | ||
1d1ccf4f | 828 | /* The socket SK is about to be used to communicate with the remote address |
9314b85a MW |
829 | * SA. Assign it a local address so that getpeername(2) does something |
830 | * useful. | |
1d1ccf4f | 831 | */ |
e4976bb0 | 832 | static int do_implicit_bind(int sk, const struct sockaddr **sa, |
833 | socklen_t *len, struct sockaddr_un *sun) | |
834 | { | |
9314b85a | 835 | address addr; |
e4976bb0 | 836 | socklen_t mylen = sizeof(*sun); |
837 | ||
9314b85a | 838 | if (acl_allows_p(connect_real, *sa)) { |
86134bfe | 839 | if (fixup_real_ip_socket(sk, (*sa)->sa_family, 0)) return (-1); |
e4976bb0 | 840 | } else { |
9314b85a | 841 | if (real_getsockname(sk, SA(sun), &mylen) < 0) return (-1); |
e4976bb0 | 842 | if (sun->sun_family == AF_UNIX) { |
843 | if (mylen < sizeof(*sun)) ((char *)sun)[mylen] = 0; | |
844 | if (!sun->sun_path[0]) { | |
9314b85a MW |
845 | wildcard_address((*sa)->sa_family, &addr.sa); |
846 | encode_inet_addr(sun, &addr.sa, WANT_FRESH); | |
847 | if (real_bind(sk, SA(sun), SUN_LEN(sun))) return (-1); | |
e4976bb0 | 848 | } |
9314b85a | 849 | encode_inet_addr(sun, *sa, WANT_EXISTING); |
e4976bb0 | 850 | *sa = SA(sun); |
851 | *len = SUN_LEN(sun); | |
852 | } | |
853 | } | |
854 | return (0); | |
855 | } | |
856 | ||
1d1ccf4f MW |
857 | /* We found the real address SA, with length LEN; if it's a Unix-domain |
858 | * address corresponding to a fake socket, convert it to cover up the | |
859 | * deception. Whatever happens, put the result at FAKE and store its length | |
860 | * at FAKELEN. | |
861 | */ | |
e4976bb0 | 862 | static void return_fake_name(struct sockaddr *sa, socklen_t len, |
863 | struct sockaddr *fake, socklen_t *fakelen) | |
864 | { | |
9314b85a | 865 | address addr; |
e4976bb0 | 866 | socklen_t alen; |
867 | ||
00a98a8a | 868 | if (sa->sa_family == AF_UNIX && |
9314b85a MW |
869 | !decode_inet_addr(&addr.sa, 0, SUN(sa), len)) { |
870 | sa = &addr.sa; | |
871 | len = family_socklen(addr.sa.sa_family); | |
e4976bb0 | 872 | } |
873 | alen = len; | |
9314b85a MW |
874 | if (len > *fakelen) len = *fakelen; |
875 | if (len > 0) memcpy(fake, sa, len); | |
e4976bb0 | 876 | *fakelen = alen; |
877 | } | |
878 | ||
1d1ccf4f | 879 | /*----- Configuration -----------------------------------------------------*/ |
e4976bb0 | 880 | |
1d1ccf4f | 881 | /* Return the process owner's home directory. */ |
e4976bb0 | 882 | static char *home(void) |
883 | { | |
884 | char *p; | |
885 | struct passwd *pw; | |
886 | ||
3ef1fec9 | 887 | if (getuid() == uid && |
888 | (p = getenv("HOME")) != 0) | |
889 | return (p); | |
890 | else if ((pw = getpwuid(uid)) != 0) | |
891 | return (pw->pw_dir); | |
892 | else | |
893 | return "/notexist"; | |
e4976bb0 | 894 | } |
895 | ||
1d1ccf4f | 896 | /* Return a good temporary directory to use. */ |
e4976bb0 | 897 | static char *tmpdir(void) |
898 | { | |
899 | char *p; | |
900 | ||
901 | if ((p = getenv("TMPDIR")) != 0) return (p); | |
902 | else if ((p = getenv("TMP")) != 0) return (p); | |
903 | else return ("/tmp"); | |
904 | } | |
905 | ||
1d1ccf4f | 906 | /* Return the user's name, or at least something distinctive. */ |
e4976bb0 | 907 | static char *user(void) |
908 | { | |
909 | static char buf[16]; | |
910 | char *p; | |
911 | struct passwd *pw; | |
912 | ||
913 | if ((p = getenv("USER")) != 0) return (p); | |
914 | else if ((p = getenv("LOGNAME")) != 0) return (p); | |
915 | else if ((pw = getpwuid(uid)) != 0) return (pw->pw_name); | |
916 | else { | |
917 | snprintf(buf, sizeof(buf), "uid-%lu", (unsigned long)uid); | |
918 | return (buf); | |
919 | } | |
920 | } | |
921 | ||
1d1ccf4f | 922 | /* Skip P over space characters. */ |
e4976bb0 | 923 | #define SKIPSPC do { while (*p && isspace(UC(*p))) p++; } while (0) |
1d1ccf4f MW |
924 | |
925 | /* Set Q to point to the next word following P, null-terminate it, and step P | |
926 | * past it. */ | |
e4976bb0 | 927 | #define NEXTWORD(q) do { \ |
928 | SKIPSPC; \ | |
929 | q = p; \ | |
930 | while (*p && !isspace(UC(*p))) p++; \ | |
931 | if (*p) *p++ = 0; \ | |
932 | } while (0) | |
1d1ccf4f MW |
933 | |
934 | /* Set Q to point to the next dotted-quad address, store the ending delimiter | |
935 | * in DEL, null-terminate it, and step P past it. */ | |
9314b85a MW |
936 | static void parse_nextaddr(char **pp, char **qq, int *del) |
937 | { | |
938 | char *p = *pp; | |
939 | ||
940 | SKIPSPC; | |
941 | if (*p == '[') { | |
942 | p++; SKIPSPC; | |
943 | *qq = p; | |
944 | p += strcspn(p, "]"); | |
945 | if (*p) *p++ = 0; | |
946 | *del = 0; | |
947 | } else { | |
948 | *qq = p; | |
949 | while (*p && (*p == '.' || isdigit(UC(*p)))) p++; | |
950 | *del = *p; | |
951 | if (*p) *p++ = 0; | |
952 | } | |
953 | *pp = p; | |
954 | } | |
1d1ccf4f MW |
955 | |
956 | /* Set Q to point to the next decimal number, store the ending delimiter in | |
957 | * DEL, null-terminate it, and step P past it. */ | |
e4976bb0 | 958 | #define NEXTNUMBER(q, del) do { \ |
959 | SKIPSPC; \ | |
960 | q = p; \ | |
961 | while (*p && isdigit(UC(*p))) p++; \ | |
962 | del = *p; \ | |
963 | if (*p) *p++ = 0; \ | |
964 | } while (0) | |
1d1ccf4f MW |
965 | |
966 | /* Push the character DEL back so we scan it again, unless it's zero | |
967 | * (end-of-file). */ | |
e4976bb0 | 968 | #define RESCAN(del) do { if (del) *--p = del; } while (0) |
1d1ccf4f MW |
969 | |
970 | /* Evaluate true if P is pointing to the word KW (and not some longer string | |
971 | * of which KW is a prefix). */ | |
972 | ||
e4976bb0 | 973 | #define KWMATCHP(kw) (strncmp(p, kw, sizeof(kw) - 1) == 0 && \ |
974 | !isalnum(UC(p[sizeof(kw) - 1])) && \ | |
975 | (p += sizeof(kw) - 1)) | |
9f82ba1f | 976 | |
1d1ccf4f MW |
977 | /* Parse a port list, starting at *PP. Port lists have the form |
978 | * [:LOW[-HIGH]]: if omitted, all ports are included; if HIGH is omitted, | |
979 | * it's as if HIGH = LOW. Store LOW in *MIN, HIGH in *MAX and set *PP to the | |
980 | * rest of the string. | |
981 | */ | |
e4976bb0 | 982 | static void parse_ports(char **pp, unsigned short *min, unsigned short *max) |
983 | { | |
984 | char *p = *pp, *q; | |
985 | int del; | |
986 | ||
987 | SKIPSPC; | |
f6049fdd | 988 | if (*p != ':') |
989 | { *min = 0; *max = 0xffff; } | |
990 | else { | |
e4976bb0 | 991 | p++; |
f6049fdd | 992 | NEXTNUMBER(q, del); *min = strtoul(q, 0, 0); RESCAN(del); |
e4976bb0 | 993 | SKIPSPC; |
f6049fdd | 994 | if (*p == '-') |
d83beb5c | 995 | { p++; NEXTNUMBER(q, del); *max = strtoul(q, 0, 0); RESCAN(del); } |
f6049fdd | 996 | else |
e4976bb0 | 997 | *max = *min; |
998 | } | |
999 | *pp = p; | |
1000 | } | |
1001 | ||
006dd63f MW |
1002 | /* Parse an address range designator starting at PP and store a |
1003 | * representation of it in R. An address range designator has the form: | |
1004 | * | |
1005 | * any | local | ADDR | ADDR - ADDR | ADDR/ADDR | ADDR/INT | |
1d1ccf4f | 1006 | */ |
006dd63f | 1007 | static int parse_addrrange(char **pp, addrrange *r) |
e4976bb0 | 1008 | { |
006dd63f MW |
1009 | char *p = *pp, *q; |
1010 | int n; | |
e4976bb0 | 1011 | int del; |
006dd63f | 1012 | int af; |
e4976bb0 | 1013 | |
006dd63f MW |
1014 | SKIPSPC; |
1015 | if (KWMATCHP("any")) r->type = ANY; | |
1016 | else if (KWMATCHP("local")) r->type = LOCAL; | |
1017 | else { | |
1018 | parse_nextaddr(&p, &q, &del); | |
1019 | af = guess_address_family(q); | |
1020 | if (inet_pton(af, q, &r->u.range.min) <= 0) goto bad; | |
1021 | RESCAN(del); | |
a6d9626b | 1022 | SKIPSPC; |
006dd63f MW |
1023 | if (*p == '-') { |
1024 | p++; | |
1025 | parse_nextaddr(&p, &q, &del); | |
1026 | if (inet_pton(af, q, &r->u.range.max) <= 0) goto bad; | |
1027 | RESCAN(del); | |
1028 | } else if (*p == '/') { | |
1029 | p++; | |
1030 | NEXTNUMBER(q, del); | |
1031 | n = strtoul(q, 0, 0); | |
1032 | r->u.range.max = r->u.range.min; | |
1033 | mask_address(af, &r->u.range.min, n, 0); | |
1034 | mask_address(af, &r->u.range.max, n, 1); | |
1035 | RESCAN(del); | |
1036 | } else | |
1037 | r->u.range.max = r->u.range.min; | |
1038 | r->type = RANGE; | |
1039 | r->u.range.af = af; | |
1040 | } | |
1041 | *pp = p; | |
1042 | return (0); | |
e4976bb0 | 1043 | |
006dd63f MW |
1044 | bad: |
1045 | return (-1); | |
1046 | } | |
1047 | ||
1048 | /* Call FUNC on each individual address range in R. */ | |
1049 | static void foreach_addrrange(const addrrange *r, | |
1050 | void (*func)(int af, | |
1051 | const ipaddr *min, | |
1052 | const ipaddr *max, | |
1053 | void *p), | |
1054 | void *p) | |
1055 | { | |
1056 | ipaddr minaddr, maxaddr; | |
1057 | int i, af; | |
1058 | ||
1059 | switch (r->type) { | |
1060 | case EMPTY: | |
1061 | break; | |
1062 | case ANY: | |
9314b85a MW |
1063 | for (i = 0; address_families[i] >= 0; i++) { |
1064 | af = address_families[i]; | |
1065 | memset(&minaddr, 0, sizeof(minaddr)); | |
1066 | maxaddr = minaddr; mask_address(af, &maxaddr, 0, 1); | |
006dd63f | 1067 | func(af, &minaddr, &maxaddr, p); |
9314b85a | 1068 | } |
006dd63f MW |
1069 | break; |
1070 | case LOCAL: | |
9314b85a MW |
1071 | for (i = 0; address_families[i] >= 0; i++) { |
1072 | af = address_families[i]; | |
1073 | memset(&minaddr, 0, sizeof(minaddr)); | |
1074 | maxaddr = minaddr; mask_address(af, &maxaddr, 0, 1); | |
006dd63f MW |
1075 | func(af, &minaddr, &minaddr, p); |
1076 | func(af, &maxaddr, &maxaddr, p); | |
9314b85a | 1077 | } |
a6d9626b | 1078 | for (i = 0; i < n_local_ipaddrs; i++) { |
006dd63f MW |
1079 | func(local_ipaddrs[i].af, |
1080 | &local_ipaddrs[i].addr, &local_ipaddrs[i].addr, | |
1081 | p); | |
a6d9626b | 1082 | } |
006dd63f MW |
1083 | break; |
1084 | case RANGE: | |
1085 | func(r->u.range.af, &r->u.range.min, &r->u.range.max, p); | |
1086 | break; | |
1087 | default: | |
1088 | abort(); | |
1089 | } | |
1090 | } | |
1091 | ||
1092 | struct add_aclnode_ctx { | |
1093 | int act; | |
1094 | unsigned short minport, maxport; | |
1095 | aclnode ***tail; | |
1096 | }; | |
1097 | ||
1098 | static void add_aclnode(int af, const ipaddr *min, const ipaddr *max, | |
1099 | void *p) | |
1100 | { | |
1101 | struct add_aclnode_ctx *ctx = p; | |
1102 | aclnode *a; | |
1103 | ||
1104 | NEW(a); | |
1105 | a->act = ctx->act; | |
1106 | a->af = af; | |
1107 | a->minaddr = *min; a->maxaddr = *max; | |
1108 | a->minport = ctx->minport; a->maxport = ctx->maxport; | |
1109 | **ctx->tail = a; *ctx->tail = &a->next; | |
1110 | } | |
1111 | ||
1112 | /* Parse an ACL line. *PP points to the end of the line; *TAIL points to | |
1113 | * the list tail (i.e., the final link in the list). An ACL entry has the | |
1114 | * form +|- ADDR-RANGE PORTS | |
1115 | * where PORTS is parsed by parse_ports above; an ACL line consists of a | |
1116 | * comma-separated sequence of entries.. | |
1117 | */ | |
1118 | static void parse_acl_line(char **pp, aclnode ***tail) | |
1119 | { | |
1120 | struct add_aclnode_ctx ctx; | |
1121 | addrrange r; | |
1122 | char *p = *pp; | |
1123 | ||
1124 | ctx.tail = tail; | |
1125 | for (;;) { | |
1126 | SKIPSPC; | |
1127 | if (*p == '+') ctx.act = ALLOW; | |
1128 | else if (*p == '-') ctx.act = DENY; | |
1129 | else goto bad; | |
1130 | ||
1131 | p++; | |
1132 | if (parse_addrrange(&p, &r)) goto bad; | |
1133 | parse_ports(&p, &ctx.minport, &ctx.maxport); | |
1134 | foreach_addrrange(&r, add_aclnode, &ctx); | |
a6d9626b | 1135 | SKIPSPC; |
1136 | if (*p != ',') break; | |
1cce4a41 | 1137 | if (*p) p++; |
e4976bb0 | 1138 | } |
67fd355a | 1139 | if (*p) goto bad; |
f797ea6d | 1140 | *pp = p; |
e4976bb0 | 1141 | return; |
1142 | ||
1143 | bad: | |
e397f0bd | 1144 | D( fprintf(stderr, "noip(%d): bad acl spec (ignored)\n", getpid()); ) |
e4976bb0 | 1145 | return; |
1146 | } | |
1147 | ||
051fa2d8 MW |
1148 | /* Parse an ACL from an environment variable VAR, attaching it to the list |
1149 | * TAIL. | |
1150 | */ | |
1151 | static void parse_acl_env(const char *var, aclnode ***tail) | |
1152 | { | |
1153 | char *p, *q; | |
1154 | ||
1155 | if ((p = getenv(var)) != 0) { | |
1156 | p = q = xstrdup(p); | |
1157 | parse_acl_line(&q, tail); | |
1158 | free(p); | |
1159 | } | |
1160 | } | |
1161 | ||
1d1ccf4f | 1162 | /* Parse the autoports configuration directive. Syntax is MIN - MAX. */ |
f6049fdd | 1163 | static void parse_autoports(char **pp) |
1164 | { | |
1165 | char *p = *pp, *q; | |
1166 | unsigned x, y; | |
1167 | int del; | |
1168 | ||
1169 | SKIPSPC; | |
1170 | NEXTNUMBER(q, del); x = strtoul(q, 0, 0); RESCAN(del); | |
1171 | SKIPSPC; | |
1172 | if (*p != '-') goto bad; p++; | |
1173 | NEXTNUMBER(q, del); y = strtoul(q, 0, 0); RESCAN(del); | |
1174 | minautoport = x; maxautoport = y; | |
67fd355a | 1175 | SKIPSPC; if (*p) goto bad; |
f797ea6d | 1176 | *pp = p; |
f6049fdd | 1177 | return; |
1178 | ||
1179 | bad: | |
e397f0bd | 1180 | D( fprintf(stderr, "noip(%d): bad port range (ignored)\n", getpid()); ) |
f6049fdd | 1181 | return; |
1182 | } | |
1183 | ||
1d1ccf4f | 1184 | /* Read the configuration from the config file and environment. */ |
e4976bb0 | 1185 | static void readconfig(void) |
1186 | { | |
1187 | FILE *fp; | |
1188 | char buf[1024]; | |
1189 | size_t n; | |
f6049fdd | 1190 | char *p, *q, *cmd; |
e397f0bd | 1191 | Dpid; |
e4976bb0 | 1192 | |
a6d9626b | 1193 | parse_acl_env("NOIP_REALBIND_BEFORE", &bind_tail); |
1194 | parse_acl_env("NOIP_REALCONNECT_BEFORE", &connect_tail); | |
f6049fdd | 1195 | if ((p = getenv("NOIP_AUTOPORTS")) != 0) { |
1196 | p = q = xstrdup(p); | |
1197 | parse_autoports(&q); | |
1198 | free(p); | |
1199 | } | |
4ab301de | 1200 | if ((p = getenv("NOIP_CONFIG")) == 0) |
1201 | snprintf(p = buf, sizeof(buf), "%s/.noip", home()); | |
e397f0bd | 1202 | D( fprintf(stderr, "noip(%d): config file: %s\n", pid, p); ) |
4ab301de | 1203 | |
1204 | if ((fp = fopen(p, "r")) == 0) { | |
e397f0bd MW |
1205 | D( fprintf(stderr, "noip(%d): couldn't read config: %s\n", |
1206 | pid, strerror(errno)); ) | |
f6049fdd | 1207 | goto done; |
4ab301de | 1208 | } |
e4976bb0 | 1209 | while (fgets(buf, sizeof(buf), fp)) { |
1210 | n = strlen(buf); | |
1211 | p = buf; | |
1212 | ||
1213 | SKIPSPC; | |
1214 | if (!*p || *p == '#') continue; | |
1215 | while (n && isspace(UC(buf[n - 1]))) n--; | |
1216 | buf[n] = 0; | |
1217 | NEXTWORD(cmd); | |
1218 | SKIPSPC; | |
1219 | ||
1220 | if (strcmp(cmd, "socketdir") == 0) | |
1221 | sockdir = xstrdup(p); | |
1222 | else if (strcmp(cmd, "realbind") == 0) | |
1223 | parse_acl_line(&p, &bind_tail); | |
1224 | else if (strcmp(cmd, "realconnect") == 0) | |
1225 | parse_acl_line(&p, &connect_tail); | |
f6049fdd | 1226 | else if (strcmp(cmd, "autoports") == 0) |
1227 | parse_autoports(&p); | |
e4976bb0 | 1228 | else if (strcmp(cmd, "debug") == 0) |
1229 | debug = *p ? atoi(p) : 1; | |
1230 | else | |
1231 | D( fprintf(stderr, "noip: bad config command %s\n", cmd); ) | |
1232 | } | |
1233 | fclose(fp); | |
1234 | ||
1235 | done: | |
a6d9626b | 1236 | parse_acl_env("NOIP_REALBIND", &bind_tail); |
1237 | parse_acl_env("NOIP_REALCONNECT", &connect_tail); | |
1238 | parse_acl_env("NOIP_REALBIND_AFTER", &bind_tail); | |
1239 | parse_acl_env("NOIP_REALCONNECT_AFTER", &connect_tail); | |
e4976bb0 | 1240 | *bind_tail = 0; |
1241 | *connect_tail = 0; | |
a6d9626b | 1242 | if (!sockdir) sockdir = getenv("NOIP_SOCKETDIR"); |
e4976bb0 | 1243 | if (!sockdir) { |
1244 | snprintf(buf, sizeof(buf), "%s/noip-%s", tmpdir(), user()); | |
1245 | sockdir = xstrdup(buf); | |
1246 | } | |
e397f0bd MW |
1247 | D( fprintf(stderr, "noip(%d): socketdir: %s\n", pid, sockdir); |
1248 | fprintf(stderr, "noip(%d): autoports: %u-%u\n", | |
1249 | pid, minautoport, maxautoport); | |
1250 | fprintf(stderr, "noip(%d): realbind acl:\n", pid); | |
e4976bb0 | 1251 | dump_acl(bind_real); |
e397f0bd | 1252 | fprintf(stderr, "noip(%d): realconnect acl:\n", pid); |
e4976bb0 | 1253 | dump_acl(connect_real); ) |
1254 | } | |
1255 | ||
1d1ccf4f | 1256 | /*----- Overridden system calls -------------------------------------------*/ |
e4976bb0 | 1257 | |
dc3956b3 MW |
1258 | static void dump_syserr(long rc) |
1259 | { fprintf(stderr, " => %ld (E%d)\n", rc, errno); } | |
1260 | ||
1261 | static void dump_sysresult(long rc) | |
1262 | { | |
1263 | if (rc < 0) dump_syserr(rc); | |
1264 | else fprintf(stderr, " => %ld\n", rc); | |
1265 | } | |
1266 | ||
1267 | static void dump_addrresult(long rc, const struct sockaddr *sa, | |
1268 | socklen_t len) | |
1269 | { | |
1270 | char addrbuf[ADDRBUFSZ]; | |
1271 | ||
1272 | if (rc < 0) dump_syserr(rc); | |
1273 | else { | |
1274 | fprintf(stderr, " => %ld [%s]\n", rc, | |
1275 | present_sockaddr(sa, len, addrbuf, sizeof(addrbuf))); | |
1276 | } | |
1277 | } | |
1278 | ||
e4976bb0 | 1279 | int socket(int pf, int ty, int proto) |
1280 | { | |
dc3956b3 MW |
1281 | int sk; |
1282 | ||
1283 | D( fprintf(stderr, "noip(%d): SOCKET pf=%d, type=%d, proto=%d", | |
1284 | getpid(), pf, ty, proto); ) | |
1285 | ||
8ce11853 | 1286 | switch (pf) { |
9314b85a MW |
1287 | default: |
1288 | if (!family_known_p(pf)) { | |
dc3956b3 | 1289 | D( fprintf(stderr, " -> unknown; refuse\n"); ) |
9314b85a | 1290 | errno = EAFNOSUPPORT; |
dc3956b3 | 1291 | sk = -1; |
9314b85a | 1292 | } |
dc3956b3 | 1293 | D( fprintf(stderr, " -> inet; substitute"); ) |
8ce11853 MW |
1294 | pf = PF_UNIX; |
1295 | proto = 0; | |
dc3956b3 | 1296 | break; |
8ce11853 | 1297 | case PF_UNIX: |
41c50995 MW |
1298 | #ifdef PF_NETLINK |
1299 | case PF_NETLINK: | |
1300 | #endif | |
dc3956b3 MW |
1301 | D( fprintf(stderr, " -> safe; permit"); ) |
1302 | break; | |
e4976bb0 | 1303 | } |
dc3956b3 MW |
1304 | sk = real_socket(pf, ty, proto); |
1305 | D( dump_sysresult(sk); ) | |
1306 | return (sk); | |
e4976bb0 | 1307 | } |
1308 | ||
1309 | int socketpair(int pf, int ty, int proto, int *sk) | |
1310 | { | |
dc3956b3 MW |
1311 | int rc; |
1312 | ||
1313 | D( fprintf(stderr, "noip(%d): SOCKETPAIR pf=%d, type=%d, proto=%d", | |
1314 | getpid(), pf, ty, proto); ) | |
1315 | if (!family_known_p(pf)) | |
1316 | D( fprintf(stderr, " -> unknown; permit"); ) | |
1317 | else { | |
1318 | D( fprintf(stderr, " -> inet; substitute"); ) | |
e4976bb0 | 1319 | pf = PF_UNIX; |
1320 | proto = 0; | |
1321 | } | |
dc3956b3 MW |
1322 | rc = real_socketpair(pf, ty, proto, sk); |
1323 | D( if (rc < 0) dump_syserr(rc); | |
1324 | else fprintf(stderr, " => %d (%d, %d)\n", rc, sk[0], sk[1]); ) | |
1325 | return (rc); | |
e4976bb0 | 1326 | } |
1327 | ||
1328 | int bind(int sk, const struct sockaddr *sa, socklen_t len) | |
1329 | { | |
1330 | struct sockaddr_un sun; | |
dc3956b3 MW |
1331 | int rc; |
1332 | Dpid; | |
e4976bb0 | 1333 | |
dc3956b3 MW |
1334 | D({ char buf[ADDRBUFSZ]; |
1335 | fprintf(stderr, "noip(%d): BIND sk=%d, sa[%d]=%s", pid, | |
1336 | sk, len, present_sockaddr(sa, len, buf, sizeof(buf))); }) | |
1337 | ||
1338 | if (!family_known_p(sa->sa_family)) | |
1339 | D( fprintf(stderr, " -> unknown af; pass through"); ) | |
1340 | else { | |
1341 | D( fprintf(stderr, " -> checking...\n"); ) | |
e4976bb0 | 1342 | PRESERVING_ERRNO({ |
9314b85a | 1343 | if (acl_allows_p(bind_real, sa)) { |
86134bfe | 1344 | if (fixup_real_ip_socket(sk, sa->sa_family, 0)) |
e4976bb0 | 1345 | return (-1); |
1346 | } else { | |
9314b85a | 1347 | encode_inet_addr(&sun, sa, WANT_FRESH); |
e4976bb0 | 1348 | sa = SA(&sun); |
1349 | len = SUN_LEN(&sun); | |
1350 | } | |
1351 | }); | |
dc3956b3 | 1352 | D( fprintf(stderr, "noip(%d): BIND ...", pid); ) |
e4976bb0 | 1353 | } |
dc3956b3 MW |
1354 | rc = real_bind(sk, sa, len); |
1355 | D( dump_sysresult(rc); ) | |
1356 | return (rc); | |
e4976bb0 | 1357 | } |
1358 | ||
1359 | int connect(int sk, const struct sockaddr *sa, socklen_t len) | |
1360 | { | |
1361 | struct sockaddr_un sun; | |
53390eff | 1362 | int rc; |
dc3956b3 | 1363 | Dpid; |
e4976bb0 | 1364 | |
dc3956b3 MW |
1365 | D({ char buf[ADDRBUFSZ]; |
1366 | fprintf(stderr, "noip(%d): CONNECT sk=%d, sa[%d]=%s", pid, | |
1367 | sk, len, present_sockaddr(sa, len, buf, sizeof(buf))); }) | |
1368 | ||
1369 | if (!family_known_p(sa->sa_family)) { | |
1370 | D( fprintf(stderr, " -> unknown af; pass through"); ) | |
9314b85a | 1371 | rc = real_connect(sk, sa, len); |
dc3956b3 MW |
1372 | } else { |
1373 | D( fprintf(stderr, " -> checking...\n"); ) | |
9314b85a MW |
1374 | PRESERVING_ERRNO({ |
1375 | do_implicit_bind(sk, &sa, &len, &sun); | |
1376 | }); | |
dc3956b3 | 1377 | D( fprintf(stderr, "noip(%d): CONNECT ...", pid); ) |
9314b85a MW |
1378 | rc = real_connect(sk, sa, len); |
1379 | if (rc < 0) { | |
1380 | switch (errno) { | |
1381 | case ENOENT: errno = ECONNREFUSED; break; | |
6df6f816 | 1382 | } |
9314b85a | 1383 | } |
53390eff | 1384 | } |
dc3956b3 | 1385 | D( dump_sysresult(rc); ) |
9314b85a | 1386 | return (rc); |
e4976bb0 | 1387 | } |
1388 | ||
1389 | ssize_t sendto(int sk, const void *buf, size_t len, int flags, | |
1390 | const struct sockaddr *to, socklen_t tolen) | |
1391 | { | |
1392 | struct sockaddr_un sun; | |
dc3956b3 MW |
1393 | ssize_t n; |
1394 | Dpid; | |
1395 | ||
1396 | D({ char addrbuf[ADDRBUFSZ]; | |
1397 | fprintf(stderr, "noip(%d): SENDTO sk=%d, len=%lu, flags=%d, to[%d]=%s", | |
1398 | pid, sk, (unsigned long)len, flags, tolen, | |
1399 | present_sockaddr(to, tolen, addrbuf, sizeof(addrbuf))); }) | |
e4976bb0 | 1400 | |
dc3956b3 MW |
1401 | if (!to) |
1402 | D( fprintf(stderr, " -> null address; leaving"); ) | |
1403 | else if (!family_known_p(to->sa_family)) | |
1404 | D( fprintf(stderr, " -> unknown af; pass through"); ) | |
1405 | else { | |
1406 | D( fprintf(stderr, " -> checking...\n"); ) | |
e4976bb0 | 1407 | PRESERVING_ERRNO({ |
1408 | do_implicit_bind(sk, &to, &tolen, &sun); | |
1409 | }); | |
dc3956b3 | 1410 | D( fprintf(stderr, "noip(%d): SENDTO ...", pid); ) |
e4976bb0 | 1411 | } |
dc3956b3 MW |
1412 | n = real_sendto(sk, buf, len, flags, to, tolen); |
1413 | D( dump_sysresult(n); ) | |
1414 | return (n); | |
e4976bb0 | 1415 | } |
1416 | ||
1417 | ssize_t recvfrom(int sk, void *buf, size_t len, int flags, | |
1418 | struct sockaddr *from, socklen_t *fromlen) | |
1419 | { | |
1420 | char sabuf[1024]; | |
1421 | socklen_t mylen = sizeof(sabuf); | |
1422 | ssize_t n; | |
dc3956b3 | 1423 | Dpid; |
e4976bb0 | 1424 | |
dc3956b3 MW |
1425 | D( fprintf(stderr, "noip(%d): RECVFROM sk=%d, len=%lu, flags=%d", |
1426 | pid, sk, (unsigned long)len, flags); ) | |
1427 | ||
1428 | if (!from) { | |
1429 | D( fprintf(stderr, " -> null addr; pass through"); ) | |
1430 | n = real_recvfrom(sk, buf, len, flags, 0, 0); | |
1431 | } else { | |
1432 | PRESERVING_ERRNO({ | |
1433 | n = real_recvfrom(sk, buf, len, flags, SA(sabuf), &mylen); | |
1434 | if (n >= 0) { | |
1435 | D( fprintf(stderr, " -> converting...\n"); ) | |
1436 | return_fake_name(SA(sabuf), mylen, from, fromlen); | |
1437 | D( fprintf(stderr, "noip(%d): ... RECVFROM", pid); ) | |
1438 | } | |
1439 | }); | |
1440 | } | |
1441 | D( dump_addrresult(n, from, fromlen ? *fromlen : 0); ) | |
e4976bb0 | 1442 | return (n); |
1443 | } | |
1444 | ||
1445 | ssize_t sendmsg(int sk, const struct msghdr *msg, int flags) | |
1446 | { | |
1447 | struct sockaddr_un sun; | |
dc3956b3 | 1448 | const struct sockaddr *sa = SA(msg->msg_name); |
e4976bb0 | 1449 | struct msghdr mymsg; |
dc3956b3 MW |
1450 | ssize_t n; |
1451 | Dpid; | |
e4976bb0 | 1452 | |
dc3956b3 MW |
1453 | D({ char addrbuf[ADDRBUFSZ]; |
1454 | fprintf(stderr, "noip(%d): SENDMSG sk=%d, " | |
1455 | "msg_flags=%d, msg_name[%d]=%s, ...", | |
1456 | pid, sk, msg->msg_flags, msg->msg_namelen, | |
1457 | present_sockaddr(sa, msg->msg_namelen, | |
1458 | addrbuf, sizeof(addrbuf))); }) | |
1459 | ||
1460 | if (!sa) | |
1461 | D( fprintf(stderr, " -> null address; leaving"); ) | |
1462 | else if (!family_known_p(sa->sa_family)) | |
1463 | D( fprintf(stderr, " -> unknown af; pass through"); ) | |
1464 | else { | |
1465 | D( fprintf(stderr, " -> checking...\n"); ) | |
e4976bb0 | 1466 | PRESERVING_ERRNO({ |
e4976bb0 | 1467 | mymsg = *msg; |
1468 | do_implicit_bind(sk, &sa, &mymsg.msg_namelen, &sun); | |
1469 | mymsg.msg_name = SA(sa); | |
1470 | msg = &mymsg; | |
1471 | }); | |
dc3956b3 | 1472 | D( fprintf(stderr, "noip(%d): SENDMSG ...", pid); ) |
e4976bb0 | 1473 | } |
dc3956b3 MW |
1474 | n = real_sendmsg(sk, msg, flags); |
1475 | D( dump_sysresult(n); ) | |
1476 | return (n); | |
e4976bb0 | 1477 | } |
1478 | ||
1479 | ssize_t recvmsg(int sk, struct msghdr *msg, int flags) | |
1480 | { | |
1481 | char sabuf[1024]; | |
dc3956b3 MW |
1482 | struct sockaddr *sa = SA(msg->msg_name); |
1483 | socklen_t len = msg->msg_namelen; | |
e4976bb0 | 1484 | ssize_t n; |
dc3956b3 | 1485 | Dpid; |
e4976bb0 | 1486 | |
dc3956b3 MW |
1487 | D( fprintf(stderr, "noip(%d): RECVMSG sk=%d msg_flags=%d, ...", |
1488 | pid, sk, msg->msg_flags); ) | |
1489 | ||
1490 | if (!msg->msg_name) { | |
1491 | D( fprintf(stderr, " -> null addr; pass through"); ) | |
9314b85a | 1492 | return (real_recvmsg(sk, msg, flags)); |
dc3956b3 MW |
1493 | } else { |
1494 | PRESERVING_ERRNO({ | |
1495 | msg->msg_name = sabuf; | |
1496 | msg->msg_namelen = sizeof(sabuf); | |
1497 | n = real_recvmsg(sk, msg, flags); | |
1498 | if (n >= 0) { | |
1499 | D( fprintf(stderr, " -> converting...\n"); ) | |
1500 | return_fake_name(SA(sabuf), msg->msg_namelen, sa, &len); | |
1501 | D( fprintf(stderr, "noip(%d): ... RECVMSG", pid); ) | |
1502 | } | |
1503 | msg->msg_name = sa; | |
1504 | msg->msg_namelen = len; | |
1505 | }); | |
1506 | } | |
1507 | D( dump_addrresult(n, sa, len); ) | |
e4976bb0 | 1508 | return (n); |
1509 | } | |
1510 | ||
1511 | int accept(int sk, struct sockaddr *sa, socklen_t *len) | |
1512 | { | |
1513 | char sabuf[1024]; | |
1514 | socklen_t mylen = sizeof(sabuf); | |
dc3956b3 MW |
1515 | int nsk; |
1516 | Dpid; | |
e4976bb0 | 1517 | |
dc3956b3 MW |
1518 | D( fprintf(stderr, "noip(%d): ACCEPT sk=%d", pid, sk); ) |
1519 | ||
1520 | nsk = real_accept(sk, SA(sabuf), &mylen); | |
1521 | if (nsk < 0) /* failed */; | |
1522 | else if (!sa) D( fprintf(stderr, " -> address not wanted"); ) | |
1523 | else { | |
1524 | D( fprintf(stderr, " -> converting...\n"); ) | |
1525 | return_fake_name(SA(sabuf), mylen, sa, len); | |
1526 | D( fprintf(stderr, "noip(%d): ... ACCEPT", pid); ) | |
1527 | } | |
1528 | D( dump_addrresult(nsk, sa, len ? *len : 0); ) | |
e4976bb0 | 1529 | return (nsk); |
1530 | } | |
1531 | ||
1532 | int getsockname(int sk, struct sockaddr *sa, socklen_t *len) | |
1533 | { | |
dc3956b3 MW |
1534 | int rc; |
1535 | Dpid; | |
1536 | ||
1537 | D( fprintf(stderr, "noip(%d): GETSOCKNAME sk=%d", pid, sk); ) | |
e4976bb0 | 1538 | PRESERVING_ERRNO({ |
1539 | char sabuf[1024]; | |
1540 | socklen_t mylen = sizeof(sabuf); | |
dc3956b3 MW |
1541 | rc = real_getsockname(sk, SA(sabuf), &mylen); |
1542 | if (rc >= 0) { | |
1543 | D( fprintf(stderr, " -> converting...\n"); ) | |
1544 | return_fake_name(SA(sabuf), mylen, sa, len); | |
1545 | D( fprintf(stderr, "noip(%d): ... GETSOCKNAME", pid); ) | |
1546 | } | |
e4976bb0 | 1547 | }); |
dc3956b3 MW |
1548 | D( dump_addrresult(rc, sa, *len); ) |
1549 | return (rc); | |
e4976bb0 | 1550 | } |
1551 | ||
1552 | int getpeername(int sk, struct sockaddr *sa, socklen_t *len) | |
1553 | { | |
dc3956b3 MW |
1554 | int rc; |
1555 | Dpid; | |
1556 | ||
1557 | D( fprintf(stderr, "noip(%d): GETPEERNAME sk=%d", pid, sk); ) | |
e4976bb0 | 1558 | PRESERVING_ERRNO({ |
1559 | char sabuf[1024]; | |
1560 | socklen_t mylen = sizeof(sabuf); | |
dc3956b3 MW |
1561 | rc = real_getpeername(sk, SA(sabuf), &mylen); |
1562 | if (rc >= 0) { | |
1563 | D( fprintf(stderr, " -> converting...\n"); ) | |
1564 | return_fake_name(SA(sabuf), mylen, sa, len); | |
1565 | D( fprintf(stderr, "noip(%d): ... GETPEERNAME", pid); ) | |
1566 | } | |
e4976bb0 | 1567 | }); |
dc3956b3 | 1568 | D( dump_addrresult(rc, sa, *len); ) |
e4976bb0 | 1569 | return (0); |
1570 | } | |
1571 | ||
1572 | int getsockopt(int sk, int lev, int opt, void *p, socklen_t *len) | |
1573 | { | |
1574 | switch (lev) { | |
1575 | case SOL_IP: | |
1576 | case SOL_TCP: | |
1577 | case SOL_UDP: | |
1578 | if (*len > 0) | |
1579 | memset(p, 0, *len); | |
1580 | return (0); | |
1581 | } | |
9314b85a | 1582 | return (real_getsockopt(sk, lev, opt, p, len)); |
e4976bb0 | 1583 | } |
1584 | ||
1585 | int setsockopt(int sk, int lev, int opt, const void *p, socklen_t len) | |
1586 | { | |
1587 | switch (lev) { | |
1588 | case SOL_IP: | |
1589 | case SOL_TCP: | |
1590 | case SOL_UDP: | |
1591 | return (0); | |
1592 | } | |
1593 | switch (opt) { | |
1594 | case SO_BINDTODEVICE: | |
1595 | case SO_ATTACH_FILTER: | |
1596 | case SO_DETACH_FILTER: | |
1597 | return (0); | |
1598 | } | |
9314b85a | 1599 | return (real_setsockopt(sk, lev, opt, p, len)); |
e4976bb0 | 1600 | } |
1601 | ||
658c1774 MW |
1602 | int ioctl(int fd, unsigned long op, ...) |
1603 | { | |
1604 | va_list ap; | |
1605 | void *arg; | |
1606 | int sk; | |
1607 | int rc; | |
1608 | ||
1609 | va_start(ap, op); | |
1610 | arg = va_arg(ap, void *); | |
1611 | ||
1612 | switch (op) { | |
1613 | case SIOCGIFADDR: | |
1614 | case SIOCGIFBRDADDR: | |
1615 | case SIOCGIFDSTADDR: | |
1616 | case SIOCGIFNETMASK: | |
1617 | PRESERVING_ERRNO({ | |
1618 | if (fixup_real_ip_socket(fd, AF_INET, &sk)) goto real; | |
1619 | }); | |
1620 | rc = real_ioctl(sk, op, arg); | |
1621 | PRESERVING_ERRNO({ close(sk); }); | |
1622 | break; | |
1623 | default: | |
1624 | real: | |
1625 | rc = real_ioctl(fd, op, arg); | |
1626 | break; | |
1627 | } | |
1628 | va_end(ap); | |
1629 | return (rc); | |
1630 | } | |
1631 | ||
1d1ccf4f | 1632 | /*----- Initialization ----------------------------------------------------*/ |
e4976bb0 | 1633 | |
1d1ccf4f | 1634 | /* Clean up the socket directory, deleting stale sockets. */ |
e4976bb0 | 1635 | static void cleanup_sockdir(void) |
1636 | { | |
1637 | DIR *dir; | |
1638 | struct dirent *d; | |
9314b85a | 1639 | address addr; |
e4976bb0 | 1640 | struct sockaddr_un sun; |
3ef1fec9 | 1641 | struct stat st; |
e397f0bd | 1642 | Dpid; |
e4976bb0 | 1643 | |
9314b85a | 1644 | if ((dir = opendir(sockdir)) == 0) return; |
4ab301de | 1645 | sun.sun_family = AF_UNIX; |
e4976bb0 | 1646 | while ((d = readdir(dir)) != 0) { |
1647 | if (d->d_name[0] == '.') continue; | |
1648 | snprintf(sun.sun_path, sizeof(sun.sun_path), | |
1649 | "%s/%s", sockdir, d->d_name); | |
9314b85a | 1650 | if (decode_inet_addr(&addr.sa, 0, &sun, SUN_LEN(&sun)) || |
3ef1fec9 | 1651 | stat(sun.sun_path, &st) || |
4ab301de | 1652 | !S_ISSOCK(st.st_mode)) { |
e397f0bd MW |
1653 | D( fprintf(stderr, "noip(%d): ignoring unknown socketdir entry `%s'\n", |
1654 | pid, sun.sun_path); ) | |
3ef1fec9 | 1655 | continue; |
4ab301de | 1656 | } |
e4976bb0 | 1657 | if (unix_socket_status(&sun, 0) == STALE) { |
e397f0bd MW |
1658 | D( fprintf(stderr, "noip(%d): clearing away stale socket %s\n", |
1659 | pid, d->d_name); ) | |
e4976bb0 | 1660 | unlink(sun.sun_path); |
1661 | } | |
1662 | } | |
1663 | closedir(dir); | |
1664 | } | |
1665 | ||
1d1ccf4f MW |
1666 | /* Find the addresses attached to local network interfaces, and remember them |
1667 | * in a table. | |
1668 | */ | |
e4976bb0 | 1669 | static void get_local_ipaddrs(void) |
1670 | { | |
9f1396d9 | 1671 | struct ifaddrs *ifa_head, *ifa; |
9314b85a | 1672 | ipaddr a; |
e4976bb0 | 1673 | int i; |
e397f0bd | 1674 | Dpid; |
e4976bb0 | 1675 | |
e397f0bd | 1676 | D( fprintf(stderr, "noip(%d): fetching local addresses...\n", pid); ) |
9f1396d9 MW |
1677 | if (getifaddrs(&ifa_head)) { perror("getifaddrs"); return; } |
1678 | for (n_local_ipaddrs = 0, ifa = ifa_head; | |
1679 | n_local_ipaddrs < MAX_LOCAL_IPADDRS && ifa; | |
1680 | ifa = ifa->ifa_next) { | |
9314b85a | 1681 | if (!ifa->ifa_addr || !family_known_p(ifa->ifa_addr->sa_family)) |
e4976bb0 | 1682 | continue; |
9314b85a MW |
1683 | ipaddr_from_sockaddr(&a, ifa->ifa_addr); |
1684 | D({ char buf[ADDRBUFSZ]; | |
e397f0bd MW |
1685 | fprintf(stderr, "noip(%d): local addr %s = %s", pid, |
1686 | ifa->ifa_name, | |
9314b85a MW |
1687 | inet_ntop(ifa->ifa_addr->sa_family, &a, |
1688 | buf, sizeof(buf))); }) | |
9f1396d9 | 1689 | for (i = 0; i < n_local_ipaddrs; i++) { |
9314b85a MW |
1690 | if (ifa->ifa_addr->sa_family == local_ipaddrs[i].af && |
1691 | ipaddr_equal_p(local_ipaddrs[i].af, &a, &local_ipaddrs[i].addr)) { | |
9f1396d9 MW |
1692 | D( fprintf(stderr, " (duplicate)\n"); ) |
1693 | goto skip; | |
1694 | } | |
1695 | } | |
1696 | D( fprintf(stderr, "\n"); ) | |
9314b85a MW |
1697 | local_ipaddrs[n_local_ipaddrs].af = ifa->ifa_addr->sa_family; |
1698 | local_ipaddrs[n_local_ipaddrs].addr = a; | |
9f1396d9 MW |
1699 | n_local_ipaddrs++; |
1700 | skip:; | |
e4976bb0 | 1701 | } |
9f1396d9 | 1702 | freeifaddrs(ifa_head); |
e4976bb0 | 1703 | } |
1704 | ||
1d1ccf4f | 1705 | /* Print the given message to standard error. Avoids stdio. */ |
72d85cdb | 1706 | static void printerr(const char *p) |
65f3786c | 1707 | { if (write(STDERR_FILENO, p, strlen(p))) ; } |
3ef1fec9 | 1708 | |
1d1ccf4f | 1709 | /* Create the socket directory, being careful about permissions. */ |
3ef1fec9 | 1710 | static void create_sockdir(void) |
1711 | { | |
1712 | struct stat st; | |
1713 | ||
b514afdd | 1714 | if (lstat(sockdir, &st)) { |
3ef1fec9 | 1715 | if (errno == ENOENT) { |
1716 | if (mkdir(sockdir, 0700)) { | |
1717 | perror("noip: creating socketdir"); | |
1718 | exit(127); | |
1719 | } | |
b514afdd | 1720 | if (!lstat(sockdir, &st)) |
3ef1fec9 | 1721 | goto check; |
1722 | } | |
1723 | perror("noip: checking socketdir"); | |
1724 | exit(127); | |
1725 | } | |
1726 | check: | |
1727 | if (!S_ISDIR(st.st_mode)) { | |
1728 | printerr("noip: bad socketdir: not a directory\n"); | |
1729 | exit(127); | |
1730 | } | |
1731 | if (st.st_uid != uid) { | |
1732 | printerr("noip: bad socketdir: not owner\n"); | |
1733 | exit(127); | |
1734 | } | |
1735 | if (st.st_mode & 077) { | |
1736 | printerr("noip: bad socketdir: not private\n"); | |
1737 | exit(127); | |
1738 | } | |
1739 | } | |
1740 | ||
1d1ccf4f MW |
1741 | /* Initialization function. */ |
1742 | static void setup(void) __attribute__((constructor)); | |
e4976bb0 | 1743 | static void setup(void) |
1744 | { | |
1745 | PRESERVING_ERRNO({ | |
1746 | char *p; | |
1747 | ||
1748 | import(); | |
3ef1fec9 | 1749 | uid = geteuid(); |
e4976bb0 | 1750 | if ((p = getenv("NOIP_DEBUG")) && atoi(p)) |
1751 | debug = 1; | |
1752 | get_local_ipaddrs(); | |
1753 | readconfig(); | |
3ef1fec9 | 1754 | create_sockdir(); |
e4976bb0 | 1755 | cleanup_sockdir(); |
1756 | }); | |
1757 | } | |
1d1ccf4f MW |
1758 | |
1759 | /*----- That's all, folks -------------------------------------------------*/ |