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