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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: identify.c,v 1.4 1999/07/27 18:30:53 mdw Exp $ |
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4 | * |
5 | * Identifies and logs the client of a connection |
6 | * |
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7 | * (c) 1999 Straylight/Edgeware |
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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: identify.c,v $ |
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32 | * Revision 1.4 1999/07/27 18:30:53 mdw |
33 | * Various minor portability fixes. |
34 | * |
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35 | * Revision 1.3 1999/07/26 23:26:21 mdw |
36 | * Minor modifications for new design. |
37 | * |
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38 | * Revision 1.2 1999/07/03 13:56:59 mdw |
39 | * Log connections to syslog or stderr as appropriate. |
40 | * |
41 | * Revision 1.1.1.1 1999/07/01 08:56:23 mdw |
42 | * Initial revision. |
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43 | * |
44 | */ |
45 | |
46 | /*----- Header files ------------------------------------------------------*/ |
47 | |
48 | #include "config.h" |
49 | |
50 | #include <errno.h> |
51 | #include <stdio.h> |
52 | #include <stdlib.h> |
53 | #include <string.h> |
54 | #include <time.h> |
55 | |
56 | #include <sys/types.h> |
57 | #include <sys/time.h> |
58 | #include <unistd.h> |
59 | #include <syslog.h> |
60 | |
61 | #include <sys/socket.h> |
62 | #include <netinet/in.h> |
63 | #include <arpa/inet.h> |
64 | #include <netdb.h> |
65 | |
66 | #include <mLib/alloc.h> |
67 | #include <mLib/conn.h> |
68 | #include <mLib/dstr.h> |
69 | #include <mLib/report.h> |
70 | #include <mLib/sel.h> |
71 | #include <mLib/selbuf.h> |
72 | #include <mLib/str.h> |
73 | |
74 | #include "bres.h" |
75 | #include "fw.h" |
76 | #include "ident.h" |
77 | #include "identify.h" |
78 | |
79 | /*----- Magic numbers -----------------------------------------------------*/ |
80 | |
81 | #define TIMEOUT 15 /* Seconds to wait for answers */ |
82 | |
83 | /*----- Data structures ---------------------------------------------------*/ |
84 | |
85 | /* --- Structure to track the progress of an identification --- */ |
86 | |
87 | typedef struct id { |
88 | id_req q; /* Copy of client's request block */ |
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89 | time_t when; /* When the connection occurred */ |
90 | conn c; /* Connection selector */ |
91 | unsigned state; /* Current state of the world */ |
92 | bres_client r; /* Backgd resolver client block */ |
93 | char host[64]; /* Resolved hostname */ |
94 | char user[32]; /* Authenticated client user */ |
95 | sel_timer t; /* Timeout selector */ |
96 | selbuf id; /* Reader for the RFC931 client */ |
97 | } id; |
98 | |
99 | #define S_HOST 1u /* Read the hostname from resolver */ |
100 | #define S_USER 2u /* Read the username from RFC931 */ |
101 | #define S_UCONN 4u /* Connected to remote RFC931 */ |
102 | #define S_TIMER 8u /* Timeout has completed */ |
103 | |
104 | /*----- Main code ---------------------------------------------------------*/ |
105 | |
106 | /* --- @id_done@ --- * |
107 | * |
108 | * Arguments: @id *i@ = pointer to identification block |
109 | * |
110 | * Returns: --- |
111 | * |
112 | * Use: Finishes with an identification block. |
113 | */ |
114 | |
115 | static void id_done(id *i) |
116 | { |
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117 | /* --- Close down the various dependent bits --- */ |
118 | |
119 | if (!(i->state & S_HOST)) |
120 | bres_abort(&i->r); |
121 | if (!(i->state & S_UCONN)) |
122 | conn_kill(&i->c); |
123 | else if (!(i->state & S_USER)) |
124 | selbuf_disable(&i->id); |
125 | if (!(i->state & S_TIMER)) |
126 | sel_rmtimer(&i->t); |
127 | |
128 | /* --- Report the final result --- */ |
129 | |
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130 | fw_log(i->when, "[%s] %s from %s@%s [%s]", |
131 | i->q.desc, i->q.act, |
132 | i->user, i->host, inet_ntoa(i->q.rsin.sin_addr)); |
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133 | |
134 | /* --- Dispose of the block --- */ |
135 | |
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136 | REFFD_DEC(i->q.r); |
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137 | free(i); |
138 | } |
139 | |
140 | /* --- @id_res@ --- * |
141 | * |
142 | * Arguments: @const char *host@ = name of the resolved host |
143 | * @void *vp@ = pointer to identification block |
144 | * |
145 | * Returns: --- |
146 | * |
147 | * Use: Responds to a completed reverse name resolution. |
148 | */ |
149 | |
150 | static void id_res(const char *host, void *vp) |
151 | { |
152 | id *i = vp; |
153 | str_sanitize(i->host, host, sizeof(i->host)); |
154 | i->state |= S_HOST; |
155 | if (i->state & S_USER) |
156 | id_done(i); |
157 | } |
158 | |
159 | /* --- @id_ident@ --- * |
160 | * |
161 | * Arguments: @char *p@ = pointer to string read from server |
162 | * @void *vp@ = pointer to identification block |
163 | * |
164 | * Returns: --- |
165 | * |
166 | * Use: Responds to a line read from the remote RFC931 server. |
167 | */ |
168 | |
169 | static void id_ident(char *p, void *vp) |
170 | { |
171 | id *i = vp; |
172 | |
173 | /* --- Get rid of the connection --- */ |
174 | |
175 | i->state |= S_USER; |
176 | selbuf_disable(&i->id); |
177 | close(i->id.reader.fd); |
178 | |
179 | /* --- Read the information from the returned line --- */ |
180 | |
181 | if (p) { |
182 | ident idbuf; |
183 | ident_parse(p, &idbuf); |
184 | if (idbuf.type == ident_userid) |
185 | str_sanitize(i->user, idbuf.u.userid.user, sizeof(i->user)); |
186 | } |
187 | |
188 | /* --- Maybe finish off this identification --- */ |
189 | |
190 | if (i->state & S_HOST) |
191 | id_done(i); |
192 | } |
193 | |
194 | /* --- @id_conn@ --- * |
195 | * |
196 | * Arguments: @int fd@ = file descriptor connected |
197 | * @void *vp@ = pointer to identification block |
198 | * |
199 | * Returns: --- |
200 | * |
201 | * Use: Responds to a completed connection to the remote RFC931 |
202 | * server. |
203 | */ |
204 | |
205 | static void id_conn(int fd, void *vp) |
206 | { |
207 | id *i = vp; |
208 | |
209 | if (fd == -1) { |
210 | i->state |= S_USER | S_UCONN; |
211 | if (i->state & S_HOST) |
212 | id_done(i); |
213 | } else { |
214 | dstr d = DSTR_INIT; |
215 | dstr_putf(&d, "%u, %u\n", |
216 | ntohs(i->q.rsin.sin_port), ntohs(i->q.lsin.sin_port)); |
217 | write(fd, d.buf, d.len); |
218 | dstr_destroy(&d); |
219 | i->state |= S_UCONN; |
220 | selbuf_init(&i->id, sel, fd, id_ident, i); |
221 | } |
222 | } |
223 | |
224 | /* --- @id_timer@ --- * |
225 | * |
226 | * Arguments: @struct timeval *tv@ = pointer to the current time |
227 | * @void *vp@ = pointer to identification block |
228 | * |
229 | * Returns: --- |
230 | * |
231 | * Use: Times an identification job out. |
232 | */ |
233 | |
234 | static void id_timer(struct timeval *tv, void *vp) |
235 | { |
236 | id *i = vp; |
237 | id_done(i); |
238 | } |
239 | |
240 | /* --- @identify@ --- * |
241 | * |
242 | * Arguments: @const id_req *q@ = pointer to request block |
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243 | * |
244 | * Returns: --- |
245 | * |
246 | * Use: Starts a background ident lookup and reverse-resolve job |
247 | * which will, eventually, report a message to the system log. |
248 | */ |
249 | |
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250 | void identify(const id_req *q) |
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251 | { |
252 | id *i; |
253 | |
254 | /* --- Initialize the block with stuff --- */ |
255 | |
256 | i = xmalloc(sizeof(*i)); |
257 | i->q = *q; |
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258 | REFFD_INC(i->q.r); |
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259 | |
260 | str_sanitize(i->host, inet_ntoa(q->rsin.sin_addr), sizeof(i->host)); |
261 | strcpy(i->user, "<ANONYMOUS>"); |
262 | i->state = 0; |
263 | i->when = time(0); |
264 | |
265 | /* --- Set up the connection to the identity server --- */ |
266 | |
267 | { |
268 | int fd; |
269 | struct sockaddr_in sin; |
270 | |
271 | if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0) |
272 | id_conn(-1, i); |
273 | else { |
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274 | memset(&sin, 0, sizeof(sin)); |
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275 | sin.sin_family = AF_INET; |
276 | sin.sin_addr = q->lsin.sin_addr; |
277 | sin.sin_port = 0; |
278 | if (bind(fd, (struct sockaddr *)&sin, sizeof(sin))) { |
279 | close(fd); |
280 | id_conn(-1, i); |
281 | } else { |
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282 | int opt = 1; |
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283 | sin.sin_family = AF_INET; |
284 | sin.sin_addr = q->rsin.sin_addr; |
285 | sin.sin_port = htons(113); |
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286 | setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt)); |
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287 | conn_init(&i->c, sel, fd, |
288 | (struct sockaddr *)&sin, sizeof(sin), |
289 | id_conn, i); |
290 | } |
291 | } |
292 | } |
293 | |
294 | /* --- Set up the name resolver --- */ |
295 | |
296 | bres_resolve(&i->r, q->rsin.sin_addr, id_res, i); |
297 | |
298 | /* --- Set up the time limiter --- */ |
299 | |
300 | { |
301 | struct timeval tv; |
302 | gettimeofday(&tv, 0); |
303 | tv.tv_sec += TIMEOUT; |
304 | sel_addtimer(sel, &i->t, &tv, id_timer, i); |
305 | } |
306 | } |
307 | |
308 | /*----- That's all, folks -------------------------------------------------*/ |