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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: inet.c,v 1.2 1999/07/27 18:30:53 mdw Exp $ |
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4 | * |
5 | * Protocol specific definitions for IPv4 sockets |
6 | * |
7 | * (c) 1999 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of the `fw' port forwarder. |
13 | * |
14 | * `fw' is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2 of the License, or |
17 | * (at your option) any later version. |
18 | * |
19 | * `fw' is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU General Public License |
25 | * along with `fw'; if not, write to the Free Software Foundation, |
26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
27 | */ |
28 | |
29 | /*----- Revision history --------------------------------------------------* |
30 | * |
31 | * $Log: inet.c,v $ |
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32 | * Revision 1.2 1999/07/27 18:30:53 mdw |
33 | * Various minor portability fixes. |
34 | * |
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35 | * Revision 1.1 1999/07/26 23:34:11 mdw |
36 | * New socket address types. |
37 | * |
38 | */ |
39 | |
40 | /*----- Header files ------------------------------------------------------*/ |
41 | |
42 | #include "config.h" |
43 | |
44 | #include <ctype.h> |
45 | #include <errno.h> |
46 | #include <stdio.h> |
47 | #include <stdlib.h> |
48 | #include <string.h> |
49 | |
50 | #include <sys/types.h> |
51 | #include <unistd.h> |
52 | |
53 | #include <sys/socket.h> |
54 | #include <netinet/in.h> |
55 | #include <arpa/inet.h> |
56 | #include <netdb.h> |
57 | |
58 | #include <mLib/alloc.h> |
59 | #include <mLib/dstr.h> |
60 | #include <mLib/report.h> |
61 | #include <mLib/sub.h> |
62 | |
63 | #include "acl.h" |
64 | #include "addr.h" |
65 | #include "conf.h" |
66 | #include "identify.h" |
67 | #include "inet.h" |
68 | #include "reffd.h" |
69 | #include "scan.h" |
70 | |
71 | /*----- Data structures ---------------------------------------------------*/ |
72 | |
73 | typedef struct inet_addrx { |
74 | addr a; |
75 | struct sockaddr_in sin; |
76 | } inet_addrx; |
77 | |
78 | typedef struct inet_opts { |
79 | addr_opts ao; |
80 | acl_entry *acl; |
81 | acl_entry **acltail; |
82 | } inet_opts; |
83 | |
84 | /*----- Protocol operations -----------------------------------------------*/ |
85 | |
86 | /* --- @read@ --- */ |
87 | |
88 | static addr *inet_read(scanner *sc, unsigned type) |
89 | { |
90 | inet_addrx *ia = xmalloc(sizeof(*ia)); |
91 | |
92 | ia->a.ops = &inet_ops; |
93 | ia->a.sz = sizeof(struct sockaddr_in); |
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94 | memset(&ia->sin, 0, sizeof(ia->sin)); |
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95 | ia->sin.sin_family = AF_INET; |
96 | |
97 | /* --- Read the host address part --- */ |
98 | |
99 | switch (type) { |
100 | case ADDR_SRC: |
101 | if (sc->t == CTOK_WORD && strcmp(sc->d.buf, "port") == 0) |
102 | token(sc); |
103 | ia->sin.sin_addr.s_addr = htonl(INADDR_ANY); |
104 | break; |
105 | case ADDR_DEST: { |
106 | struct hostent *h; |
107 | dstr d = DSTR_INIT; |
108 | conf_name(sc, '.', &d); |
109 | if ((h = gethostbyname(d.buf)) == 0) |
110 | error(sc, "couldn't resolve Internet address `%s'", d.buf); |
111 | memcpy(&ia->sin.sin_addr, h->h_addr, sizeof(struct in_addr)); |
112 | dstr_destroy(&d); |
113 | if (sc->t == ':') |
114 | token(sc); |
115 | } break; |
116 | } |
117 | |
118 | /* --- Read the port number --- */ |
119 | |
120 | { |
121 | struct servent *s; |
122 | |
123 | if (sc->t != CTOK_WORD) |
124 | error(sc, "parse error, TCP port expected"); |
125 | if (isdigit((unsigned char)sc->d.buf[0])) |
126 | ia->sin.sin_port = htons(atoi(sc->d.buf)); |
127 | else if ((s = getservbyname(sc->d.buf, "tcp")) == 0) |
128 | error(sc, "unknown tcp service `%s'", sc->d.buf); |
129 | else |
130 | ia->sin.sin_port = s->s_port; |
131 | token(sc); |
132 | } |
133 | |
134 | return (&ia->a); |
135 | } |
136 | |
137 | /* --- @destroy@ --- */ |
138 | |
139 | static void inet_destroy(addr *a) |
140 | { |
141 | inet_addrx *ia = (inet_addrx *)a; |
142 | DESTROY(ia); |
143 | } |
144 | |
145 | /* --- @print@ --- */ |
146 | |
147 | static void inet_print(addr *a, unsigned type, dstr *d) |
148 | { |
149 | inet_addrx *ia = (inet_addrx *)a; |
150 | switch (type) { |
151 | case ADDR_SRC: |
152 | dstr_putf(d, "inet:%u", (unsigned)ntohs(ia->sin.sin_port)); |
153 | break; |
154 | case ADDR_DEST: |
155 | dstr_putf(d, "inet:%s:%u", |
156 | inet_ntoa(ia->sin.sin_addr), |
157 | (unsigned)ntohs(ia->sin.sin_port)); |
158 | break; |
159 | } |
160 | } |
161 | |
162 | /* --- @initopts@ --- */ |
163 | |
164 | static addr_opts *inet_initopts(void) |
165 | { |
166 | inet_opts *io = CREATE(inet_opts); |
167 | io->acl = 0; |
168 | io->acltail = &io->acl; |
169 | return (&io->ao); |
170 | } |
171 | |
172 | /* --- @option@ --- */ |
173 | |
174 | static int inet_option(scanner *sc, addr_opts *ao) |
175 | { |
176 | inet_opts *io = (inet_opts *)ao; |
177 | |
178 | CONF_BEGIN(sc, "inet", "Internet socket") |
179 | |
180 | unsigned act; |
181 | |
182 | /* --- Access control limitations --- */ |
183 | |
184 | if ((strcmp(sc->d.buf, "allow") == 0 && (act = ACL_ALLOW, 1)) || |
185 | (strcmp(sc->d.buf, "deny") == 0 && (act = ACL_DENY, 1))) { |
186 | struct hostent *h; |
187 | struct netent *n; |
188 | struct in_addr a, m; |
189 | dstr d = DSTR_INIT; |
190 | |
191 | /* --- Find the host or network address --- */ |
192 | |
193 | token(sc); |
194 | if (sc->t == CTOK_WORD && strcmp(sc->d.buf, "from") == 0) |
195 | token(sc); |
196 | conf_name(sc, '.', &d); |
197 | if ((n = getnetbyname(d.buf)) != 0) |
198 | a.s_addr = htonl(n->n_net); |
199 | else if ((h = gethostbyname(d.buf)) == 0) |
200 | error(sc, "couldn't resolve address `%s'", d.buf); |
201 | else |
202 | memcpy(&a, h->h_addr, sizeof(struct in_addr)); |
203 | |
204 | /* --- Find the netmask, if any --- */ |
205 | |
206 | if (sc->t != '/') |
207 | m.s_addr = ~0ul; |
208 | else { |
209 | token(sc); |
210 | DRESET(&d); |
211 | conf_name(sc, '.', &d); |
212 | if (strchr(d.buf, '.') == 0) { |
213 | int n = atoi(d.buf); |
214 | if (n == 0) |
215 | m.s_addr = 0; |
216 | else |
217 | m.s_addr = htonl((~0ul << (32 - n)) & 0xffffffff); |
218 | } else { |
219 | #ifdef HAVE_INET_ATON |
220 | if (!inet_aton(d.buf, &m)) |
221 | error(sc, "bad netmask `%s'", d.buf); |
222 | #else |
223 | m.s_addr = inet_addr(d.buf); |
224 | #endif |
225 | } |
226 | } |
227 | dstr_destroy(&d); |
228 | |
229 | /* --- Add the access control entry --- */ |
230 | |
231 | acl_add(io ? &io->acltail : 0, act, a, m); |
232 | CONF_ACCEPT; |
233 | } |
234 | |
235 | /* --- Anything unrecognized --- */ |
236 | |
237 | CONF_END; |
238 | } |
239 | |
240 | /* --- @accept@ --- */ |
241 | |
242 | static reffd *inet_accept(int fd, addr_opts *ao, const char *desc) |
243 | { |
244 | inet_opts *io = (inet_opts *)ao; |
245 | int nfd; |
246 | id_req q; |
247 | int lsinsz = sizeof(q.lsin), rsinsz = sizeof(q.rsin); |
248 | |
249 | /* --- Accept the new connection --- */ |
250 | |
251 | if ((nfd = accept(fd, (struct sockaddr *)&q.rsin, &rsinsz)) < 0) |
252 | return (0); |
253 | if (getsockname(nfd, (struct sockaddr *)&q.lsin, &lsinsz)) { |
254 | close(nfd); |
255 | return (0); |
256 | } |
257 | q.desc = desc; |
258 | q.r = reffd_init(nfd); |
259 | |
260 | /* --- Find out whether this connection is allowed --- */ |
261 | |
262 | if (!acl_check(io->acl, q.rsin.sin_addr)) { |
263 | q.act = "refused"; |
264 | if (!(io->ao.f & ADDRF_NOLOG)) |
265 | identify(&q); |
266 | REFFD_DEC(q.r); |
267 | return (0); |
268 | } |
269 | |
270 | /* --- Everything seems to be OK --- */ |
271 | |
272 | q.act = "accepted"; |
273 | if (!(io->ao.f & ADDRF_NOLOG)) |
274 | identify(&q); |
275 | return (q.r); |
276 | } |
277 | |
278 | /* --- @freeopts@ --- */ |
279 | |
280 | static void inet_freeopts(addr_opts *ao) |
281 | { |
282 | inet_opts *io = (inet_opts *)ao; |
283 | acl_free(io->acl); |
284 | DESTROY(ao); |
285 | } |
286 | |
287 | /* --- Ops table --- */ |
288 | |
289 | addr_ops inet_ops = { |
290 | "inet", PF_INET, |
291 | inet_read, inet_destroy, inet_print, |
292 | inet_initopts, inet_option, inet_accept, inet_freeopts, 0, 0 |
293 | }; |
294 | |
295 | /*----- That's all, folks -------------------------------------------------*/ |