aa1f699e |
1 | /* -*-c-*- |
aa1f699e |
2 | * |
3 | * Protocol specific definitions for IPv4 sockets |
4 | * |
5 | * (c) 1999 Straylight/Edgeware |
6 | */ |
7 | |
8 | /*----- Licensing notice --------------------------------------------------* |
9 | * |
10 | * This file is part of the `fw' port forwarder. |
11 | * |
12 | * `fw' is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU General Public License as published by |
14 | * the Free Software Foundation; either version 2 of the License, or |
15 | * (at your option) any later version. |
16 | * |
17 | * `fw' is distributed in the hope that it will be useful, |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
20 | * GNU General Public License for more details. |
21 | * |
22 | * You should have received a copy of the GNU General Public License |
23 | * along with `fw'; if not, write to the Free Software Foundation, |
24 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
25 | */ |
26 | |
aa1f699e |
27 | /*----- Header files ------------------------------------------------------*/ |
28 | |
29 | #include "config.h" |
30 | |
31 | #include <ctype.h> |
32 | #include <errno.h> |
33 | #include <stdio.h> |
34 | #include <stdlib.h> |
35 | #include <string.h> |
36 | |
37 | #include <sys/types.h> |
38 | #include <unistd.h> |
39 | |
40 | #include <sys/socket.h> |
41 | #include <netinet/in.h> |
42 | #include <arpa/inet.h> |
43 | #include <netdb.h> |
44 | |
45 | #include <mLib/alloc.h> |
46 | #include <mLib/dstr.h> |
0ac54f22 |
47 | #include <mLib/fdflags.h> |
aa1f699e |
48 | #include <mLib/report.h> |
49 | #include <mLib/sub.h> |
50 | |
51 | #include "acl.h" |
52 | #include "addr.h" |
53 | #include "conf.h" |
0ac54f22 |
54 | #include "fw.h" |
aa1f699e |
55 | #include "identify.h" |
56 | #include "inet.h" |
ee599f55 |
57 | #include "privconn.h" |
aa1f699e |
58 | #include "reffd.h" |
59 | #include "scan.h" |
0ac54f22 |
60 | #include "socket.h" |
aa1f699e |
61 | |
62 | /*----- Data structures ---------------------------------------------------*/ |
63 | |
64 | typedef struct inet_addrx { |
65 | addr a; |
66 | struct sockaddr_in sin; |
67 | } inet_addrx; |
68 | |
69 | typedef struct inet_opts { |
70 | addr_opts ao; |
0ac54f22 |
71 | struct in_addr bind; |
72 | } inet_opts; |
73 | |
74 | typedef struct inet_srcopts { |
75 | inet_opts io; |
aa1f699e |
76 | acl_entry *acl; |
77 | acl_entry **acltail; |
0ac54f22 |
78 | } inet_srcopts; |
79 | |
80 | typedef struct inet_targopts { |
81 | inet_opts io; |
ee599f55 |
82 | int ipriv; |
0ac54f22 |
83 | } inet_targopts; |
84 | |
ee599f55 |
85 | #define ADDRF_PRIVCONN 16u |
86 | |
0ac54f22 |
87 | static inet_srcopts inet_globalsrc = |
88 | { { { 0 }, { INADDR_ANY } }, 0, &inet_globalsrc.acl }; |
89 | static inet_targopts inet_globaltarg = |
90 | { { { 0 }, { INADDR_ANY } } }; |
aa1f699e |
91 | |
92 | /*----- Protocol operations -----------------------------------------------*/ |
93 | |
94 | /* --- @read@ --- */ |
95 | |
96 | static addr *inet_read(scanner *sc, unsigned type) |
97 | { |
98 | inet_addrx *ia = xmalloc(sizeof(*ia)); |
99 | |
100 | ia->a.ops = &inet_ops; |
101 | ia->a.sz = sizeof(struct sockaddr_in); |
e0ce9d38 |
102 | memset(&ia->sin, 0, sizeof(ia->sin)); |
aa1f699e |
103 | ia->sin.sin_family = AF_INET; |
104 | |
105 | /* --- Read the host address part --- */ |
106 | |
107 | switch (type) { |
108 | case ADDR_SRC: |
109 | if (sc->t == CTOK_WORD && strcmp(sc->d.buf, "port") == 0) |
110 | token(sc); |
111 | ia->sin.sin_addr.s_addr = htonl(INADDR_ANY); |
112 | break; |
113 | case ADDR_DEST: { |
114 | struct hostent *h; |
115 | dstr d = DSTR_INIT; |
116 | conf_name(sc, '.', &d); |
117 | if ((h = gethostbyname(d.buf)) == 0) |
118 | error(sc, "couldn't resolve Internet address `%s'", d.buf); |
119 | memcpy(&ia->sin.sin_addr, h->h_addr, sizeof(struct in_addr)); |
120 | dstr_destroy(&d); |
121 | if (sc->t == ':') |
122 | token(sc); |
123 | } break; |
124 | } |
125 | |
126 | /* --- Read the port number --- */ |
127 | |
128 | { |
129 | struct servent *s; |
130 | |
131 | if (sc->t != CTOK_WORD) |
132 | error(sc, "parse error, TCP port expected"); |
133 | if (isdigit((unsigned char)sc->d.buf[0])) |
134 | ia->sin.sin_port = htons(atoi(sc->d.buf)); |
135 | else if ((s = getservbyname(sc->d.buf, "tcp")) == 0) |
136 | error(sc, "unknown tcp service `%s'", sc->d.buf); |
137 | else |
138 | ia->sin.sin_port = s->s_port; |
139 | token(sc); |
140 | } |
141 | |
142 | return (&ia->a); |
143 | } |
144 | |
145 | /* --- @destroy@ --- */ |
146 | |
147 | static void inet_destroy(addr *a) |
148 | { |
149 | inet_addrx *ia = (inet_addrx *)a; |
150 | DESTROY(ia); |
151 | } |
152 | |
153 | /* --- @print@ --- */ |
154 | |
155 | static void inet_print(addr *a, unsigned type, dstr *d) |
156 | { |
157 | inet_addrx *ia = (inet_addrx *)a; |
158 | switch (type) { |
159 | case ADDR_SRC: |
160 | dstr_putf(d, "inet:%u", (unsigned)ntohs(ia->sin.sin_port)); |
161 | break; |
162 | case ADDR_DEST: |
163 | dstr_putf(d, "inet:%s:%u", |
164 | inet_ntoa(ia->sin.sin_addr), |
165 | (unsigned)ntohs(ia->sin.sin_port)); |
166 | break; |
167 | } |
168 | } |
169 | |
170 | /* --- @initopts@ --- */ |
171 | |
0ac54f22 |
172 | static addr_opts *inet_initsrcopts(void) |
aa1f699e |
173 | { |
0ac54f22 |
174 | inet_srcopts *io = CREATE(inet_srcopts); |
175 | *io = inet_globalsrc; |
aa1f699e |
176 | io->acl = 0; |
177 | io->acltail = &io->acl; |
0ac54f22 |
178 | return (&io->io.ao); |
179 | } |
180 | |
181 | static addr_opts *inet_inittargopts(void) |
182 | { |
183 | inet_targopts *io = CREATE(inet_targopts); |
184 | *io = inet_globaltarg; |
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185 | io->ipriv = -1; |
0ac54f22 |
186 | return (&io->io.ao); |
aa1f699e |
187 | } |
188 | |
189 | /* --- @option@ --- */ |
190 | |
0ac54f22 |
191 | static void addropt(scanner *sc, inet_opts *io) |
aa1f699e |
192 | { |
0ac54f22 |
193 | dstr d = DSTR_INIT; |
194 | struct hostent *h; |
aa1f699e |
195 | |
0ac54f22 |
196 | token(sc); |
197 | if (sc->t == '=') |
198 | token(sc); |
199 | if (sc->t == CTOK_WORD && strcmp(sc->d.buf, "any") == 0) |
200 | io->bind.s_addr = INADDR_ANY; |
201 | else { |
202 | conf_name(sc, '.', &d); |
203 | if ((h = gethostbyname(d.buf)) == 0) |
204 | error(sc, "couldn't resolve address `%s'", d.buf); |
205 | memcpy(&io->bind, h->h_addr, sizeof(struct in_addr)); |
206 | } |
207 | } |
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208 | |
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209 | static int srcopt(scanner *sc, addr_opts *ao) |
210 | { |
211 | inet_srcopts *io = (inet_srcopts *)ao; |
aa1f699e |
212 | unsigned act; |
213 | |
0ac54f22 |
214 | CONF_BEGIN(sc, "source", "Internet socket source") |
215 | |
216 | /* --- Initialization --- */ |
217 | |
218 | if (!io) { |
219 | if (!inet_globalsrc.acltail) |
220 | inet_globalsrc.acltail = &inet_globalsrc.acl; |
221 | io = &inet_globalsrc; |
222 | } |
223 | |
224 | /* --- Source address configuration --- */ |
225 | |
226 | if (strcmp(sc->d.buf, "addr") == 0) { |
227 | addropt(sc, &io->io); |
228 | CONF_ACCEPT; |
229 | } |
230 | |
aa1f699e |
231 | /* --- Access control limitations --- */ |
232 | |
233 | if ((strcmp(sc->d.buf, "allow") == 0 && (act = ACL_ALLOW, 1)) || |
234 | (strcmp(sc->d.buf, "deny") == 0 && (act = ACL_DENY, 1))) { |
235 | struct hostent *h; |
236 | struct netent *n; |
237 | struct in_addr a, m; |
238 | dstr d = DSTR_INIT; |
239 | |
0ac54f22 |
240 | /* --- Find out what's going on --- */ |
aa1f699e |
241 | |
242 | token(sc); |
243 | if (sc->t == CTOK_WORD && strcmp(sc->d.buf, "from") == 0) |
244 | token(sc); |
aa1f699e |
245 | |
ee599f55 |
246 | if (sc->t == CTOK_WORD && (strcmp(sc->d.buf, "priv") == 0 || |
247 | strcmp(sc->d.buf, "priv-port") == 0)) { |
0ac54f22 |
248 | acl_addpriv(&io->acltail, act); |
aa1f699e |
249 | token(sc); |
0ac54f22 |
250 | } else { |
251 | if (sc->t == CTOK_WORD && strcmp(sc->d.buf, "host") == 0) |
252 | token(sc); |
253 | |
254 | /* --- Find the host or network address --- */ |
255 | |
aa1f699e |
256 | conf_name(sc, '.', &d); |
0ac54f22 |
257 | #ifdef HAVE_GETNETBYNAME |
258 | if ((n = getnetbyname(d.buf)) != 0) |
259 | a.s_addr = htonl(n->n_net); |
260 | else |
261 | #endif |
262 | if ((h = gethostbyname(d.buf)) == 0) |
263 | error(sc, "couldn't resolve address `%s'", d.buf); |
aa1f699e |
264 | else |
0ac54f22 |
265 | memcpy(&a, h->h_addr, sizeof(struct in_addr)); |
266 | |
267 | /* --- Find the netmask, if any --- */ |
268 | |
269 | if (sc->t != '/') |
270 | m.s_addr = ~0ul; |
271 | else { |
272 | token(sc); |
273 | DRESET(&d); |
274 | conf_name(sc, '.', &d); |
275 | if (strchr(d.buf, '.') == 0) { |
276 | int n = atoi(d.buf); |
277 | if (n == 0) |
278 | m.s_addr = 0; |
279 | else |
280 | m.s_addr = htonl((~0ul << (32 - n)) & 0xffffffff); |
281 | } else { |
aa1f699e |
282 | #ifdef HAVE_INET_ATON |
0ac54f22 |
283 | if (!inet_aton(d.buf, &m)) |
284 | error(sc, "bad netmask `%s'", d.buf); |
aa1f699e |
285 | #else |
0ac54f22 |
286 | m.s_addr = inet_addr(d.buf); |
aa1f699e |
287 | #endif |
0ac54f22 |
288 | } |
aa1f699e |
289 | } |
0ac54f22 |
290 | dstr_destroy(&d); |
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291 | |
0ac54f22 |
292 | /* --- Add the access control entry --- */ |
aa1f699e |
293 | |
0ac54f22 |
294 | acl_addhost(&io->acltail, act, a, m); |
295 | } |
aa1f699e |
296 | CONF_ACCEPT; |
297 | } |
298 | |
299 | /* --- Anything unrecognized --- */ |
300 | |
301 | CONF_END; |
302 | } |
303 | |
0ac54f22 |
304 | static int targopt(scanner *sc, addr_opts *ao) |
305 | { |
306 | inet_targopts *io = (inet_targopts *)ao; |
307 | |
308 | CONF_BEGIN(sc, "dest", "Internet socket target"); |
309 | if (strcmp(sc->d.buf, "addr") == 0) { |
310 | addropt(sc, &io->io); |
311 | CONF_ACCEPT; |
312 | } |
ee599f55 |
313 | if (strcmp(sc->d.buf, "priv") == 0 || |
314 | strcmp(sc->d.buf, "priv-port") == 0) { |
315 | token(sc); |
316 | if (sc->t == '=') token(sc); |
317 | if (conf_enum(sc, "no,yes", ENUM_ABBREV, "privileged connection status")) |
318 | io->io.ao.f |= ADDRF_PRIVCONN; |
319 | else |
320 | io->io.ao.f &= ~ADDRF_PRIVCONN; |
321 | CONF_ACCEPT; |
322 | } |
0ac54f22 |
323 | CONF_END; |
324 | } |
325 | |
326 | static int inet_option(scanner *sc, addr_opts *ao, unsigned type) |
327 | { |
328 | CONF_BEGIN(sc, "inet", "Internet socket"); |
329 | if (type != ADDR_DEST && srcopt(sc, ao)) |
330 | CONF_ACCEPT; |
331 | if (type != ADDR_SRC && targopt(sc, ao)) |
332 | CONF_ACCEPT; |
333 | CONF_END; |
334 | } |
335 | |
ee599f55 |
336 | /* --- @confirm@ --- */ |
337 | |
338 | static void inet_confirm(addr *a, unsigned type, addr_opts *ao) |
339 | { |
340 | inet_addrx *ia = (inet_addrx *)a; |
341 | |
342 | switch (type) { |
343 | case ADDR_DEST: { |
344 | inet_targopts *io = (inet_targopts *)ao; |
345 | if ((io->io.ao.f & ADDRF_PRIVCONN) && |
346 | (io->ipriv = privconn_adddest(ia->sin.sin_addr, |
347 | ia->sin.sin_port)) < 0) |
348 | die(1, "couldn't add privileged connection target (too late)"); |
349 | } break; |
350 | } |
351 | } |
352 | |
0ac54f22 |
353 | /* --- @freeopts@ --- */ |
354 | |
355 | static void inet_freesrcopts(addr_opts *ao) |
356 | { |
357 | inet_srcopts *io = (inet_srcopts *)ao; |
358 | acl_free(io->acl); |
359 | DESTROY(io); |
360 | } |
361 | |
362 | static void inet_freetargopts(addr_opts *ao) |
363 | { |
364 | inet_targopts *io = (inet_targopts *)ao; |
365 | DESTROY(io); |
366 | } |
367 | |
368 | /* --- @bind@ --- */ |
369 | |
370 | static int inet_bind(addr *a, addr_opts *ao) |
371 | { |
372 | inet_addrx *ia = (inet_addrx *)a; |
373 | inet_srcopts *io = (inet_srcopts *)ao; |
374 | struct sockaddr_in sin; |
375 | int opt = 1; |
376 | int fd; |
377 | |
378 | if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0) |
379 | goto fail_0; |
380 | setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)); |
381 | fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC); |
382 | sin = ia->sin; |
383 | sin.sin_addr = io->io.bind; |
384 | if (bind(fd, (struct sockaddr *)&sin, sizeof(ia->sin))) |
385 | goto fail_1; |
386 | return (fd); |
387 | |
388 | fail_1: |
389 | close(fd); |
390 | fail_0: |
391 | return (-1); |
392 | } |
393 | |
aa1f699e |
394 | /* --- @accept@ --- */ |
395 | |
396 | static reffd *inet_accept(int fd, addr_opts *ao, const char *desc) |
397 | { |
0ac54f22 |
398 | inet_srcopts *io = (inet_srcopts *)ao; |
aa1f699e |
399 | int nfd; |
400 | id_req q; |
bc241e98 |
401 | size_t lsinsz = sizeof(q.lsin), rsinsz = sizeof(q.rsin); |
0ac54f22 |
402 | int act = ACL_ALLOW; |
aa1f699e |
403 | |
404 | /* --- Accept the new connection --- */ |
405 | |
406 | if ((nfd = accept(fd, (struct sockaddr *)&q.rsin, &rsinsz)) < 0) |
407 | return (0); |
408 | if (getsockname(nfd, (struct sockaddr *)&q.lsin, &lsinsz)) { |
409 | close(nfd); |
410 | return (0); |
411 | } |
412 | q.desc = desc; |
413 | q.r = reffd_init(nfd); |
414 | |
415 | /* --- Find out whether this connection is allowed --- */ |
416 | |
0ac54f22 |
417 | if (!acl_check(io->acl, q.rsin.sin_addr, ntohs(q.rsin.sin_port), &act)) |
418 | acl_check(inet_globalsrc.acl, q.rsin.sin_addr, |
419 | ntohs(q.rsin.sin_port), &act); |
420 | if (act != ACL_ALLOW) { |
aa1f699e |
421 | q.act = "refused"; |
0ac54f22 |
422 | if (!(io->io.ao.f & ADDRF_NOLOG)) |
aa1f699e |
423 | identify(&q); |
424 | REFFD_DEC(q.r); |
425 | return (0); |
426 | } |
427 | |
428 | /* --- Everything seems to be OK --- */ |
429 | |
430 | q.act = "accepted"; |
0ac54f22 |
431 | if (!(io->io.ao.f & ADDRF_NOLOG)) |
aa1f699e |
432 | identify(&q); |
433 | return (q.r); |
434 | } |
435 | |
0ac54f22 |
436 | /* --- @connect@ --- */ |
aa1f699e |
437 | |
0ac54f22 |
438 | static int inet_connect(addr *a, addr_opts *ao, conn *c, endpt *e) |
aa1f699e |
439 | { |
0ac54f22 |
440 | inet_addrx *ia = (inet_addrx *)a; |
441 | inet_targopts *io = (inet_targopts *)ao; |
442 | int fd; |
443 | |
ee599f55 |
444 | if (io->ipriv >= 0) { |
445 | return (privconn_connect(c, sel, io->ipriv, io->io.bind, |
446 | starget_connected, e)); |
447 | } |
0ac54f22 |
448 | if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0) |
449 | goto fail_0; |
450 | if (io->io.bind.s_addr != INADDR_ANY) { |
451 | struct sockaddr_in sin; |
452 | memset(&sin, 0, sizeof(sin)); |
453 | sin.sin_family = AF_INET; |
454 | sin.sin_addr = io->io.bind; |
455 | sin.sin_port = 0; |
456 | if (bind(fd, (struct sockaddr *)&sin, sizeof(sin))) |
457 | goto fail_1; |
458 | } |
459 | fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC); |
460 | return (conn_init(c, sel, fd, (struct sockaddr *)&ia->sin, sizeof(ia->sin), |
461 | starget_connected, e)); |
462 | fail_1: |
463 | close(fd); |
464 | fail_0: |
465 | return (-1); |
aa1f699e |
466 | } |
467 | |
468 | /* --- Ops table --- */ |
469 | |
470 | addr_ops inet_ops = { |
0ac54f22 |
471 | "inet", |
aa1f699e |
472 | inet_read, inet_destroy, inet_print, |
ee599f55 |
473 | inet_initsrcopts, inet_option, inet_confirm, inet_freesrcopts, |
0ac54f22 |
474 | inet_bind, 0, inet_accept, |
475 | inet_inittargopts, inet_freetargopts, |
476 | inet_connect |
aa1f699e |
477 | }; |
478 | |
479 | /*----- That's all, folks -------------------------------------------------*/ |