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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: ident.c,v 1.5 2002/01/13 13:33:15 mdw Exp $ |
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4 | * |
5 | * Nonblocking RFC931 client |
6 | * |
7 | * (c) 1999 Mark Wooding |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of the mLib utilities library. |
13 | * |
14 | * mLib is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
19 | * mLib 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 Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with mLib; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
30 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: ident.c,v $ |
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33 | * Revision 1.5 2002/01/13 13:33:15 mdw |
34 | * Track interface change for @lbuf@. |
35 | * |
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36 | * Revision 1.4 2001/06/22 19:35:39 mdw |
37 | * New @conn_init@ interface. |
38 | * |
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39 | * Revision 1.3 2000/10/08 11:17:45 mdw |
40 | * (ident_socket): change sizes to be @size_t@. |
41 | * |
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42 | * Revision 1.2 2000/06/17 10:38:35 mdw |
43 | * Track changes to selbuf interface. |
44 | * |
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45 | * Revision 1.1 1999/10/04 21:41:58 mdw |
46 | * Added ident client from `fw'. |
47 | * |
48 | */ |
49 | |
50 | /*----- Header files ------------------------------------------------------*/ |
51 | |
52 | #include <ctype.h> |
53 | #include <stdio.h> |
54 | #include <stdlib.h> |
55 | #include <string.h> |
56 | |
57 | #include <sys/types.h> |
58 | #include <unistd.h> |
59 | |
60 | #include <sys/socket.h> |
61 | #include <netinet/in.h> |
62 | #include <arpa/inet.h> |
63 | #include <netdb.h> |
64 | |
65 | #include "conn.h" |
66 | #include "dstr.h" |
67 | #include "exc.h" |
68 | #include "ident.h" |
69 | #include "selbuf.h" |
70 | |
71 | /*----- Main code ---------------------------------------------------------*/ |
72 | |
73 | /* --- @next@ --- * |
74 | * |
75 | * Arguments: @char **pp@ = address of string pointer |
76 | * |
77 | * Returns: Address of next token. |
78 | * |
79 | * Use: Reads the next token from the result string. Tokens are |
80 | * terminated by whitespace, or `:' or `,' characters. The |
81 | * result string has had `\' escapes removed; it's stored in |
82 | * the same memory as the input string. The actual content |
83 | * of the delimiter doesn't seem to be interesting, so it |
84 | * gets thrown away. |
85 | */ |
86 | |
87 | static char *next(char **pp) |
88 | { |
89 | char *p, *q, *r; |
90 | |
91 | /* --- Deal with reads past the end of the string --- */ |
92 | |
93 | if (!*pp) |
94 | return (""); |
95 | |
96 | /* --- Initialize various pointers into the string --- */ |
97 | |
98 | p = q = r = *pp; |
99 | |
100 | /* --- Skip past any leading whitespace --- */ |
101 | |
102 | while (isspace((unsigned char)*p)) |
103 | p++; |
104 | |
105 | /* --- Now start work on the string itself --- */ |
106 | |
107 | for (;;) { |
108 | if (*p == 0 || *p == ':' || *p == ',' || isspace((unsigned char)*p)) |
109 | break; |
110 | else if (*p == '\\') { |
111 | p++; |
112 | if (!*p) { |
113 | *q++ = '\\'; |
114 | break; |
115 | } |
116 | } |
117 | *q++ = *p++; |
118 | } |
119 | |
120 | /* --- Tidy up afterwards --- */ |
121 | |
122 | while (isspace((unsigned char)*p)) |
123 | p++; |
124 | if (*p == 0) |
125 | *pp = 0; |
126 | else if (*p == ':' || *p == ',') |
127 | *pp = p + 1; |
128 | else |
129 | *pp = p; |
130 | *q = 0; |
131 | |
132 | return (r); |
133 | } |
134 | |
135 | /* --- @parse@ --- * |
136 | * |
137 | * Arguments: @char *p@ = pointer to input string from identd |
138 | * @ident_reply *i@ = pointer to output block |
139 | * |
140 | * Returns: --- |
141 | * |
142 | * Use: Parses a result string from an RFC931 (identd) server. |
143 | */ |
144 | |
145 | static void parse(char *p, ident_reply *i) |
146 | { |
147 | char *q; |
148 | |
149 | /* --- Read the source and destination port numbers --- */ |
150 | |
151 | i->sport = atoi(next(&p)); |
152 | i->dport = atoi(next(&p)); |
153 | |
154 | /* --- Find out what sort of a reply this is --- */ |
155 | |
156 | q = next(&p); |
157 | if (strcmp(q, "USERID") == 0) { |
158 | i->type = IDENT_USERID; |
159 | i->u.userid.os = next(&p); |
160 | i->u.userid.user = next(&p); |
161 | } else if (strcmp(q, "ERROR") == 0) { |
162 | i->type = IDENT_ERROR; |
163 | i->u.error = next(&p); |
164 | } else |
165 | i->type = IDENT_BAD; |
166 | } |
167 | |
168 | /* --- @line@ --- * |
169 | * |
170 | * Arguments: @char *s@ = pointer to string from ident server |
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171 | * @size_t len@ = length of the line |
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172 | * @void *p@ = pointer to my request block |
173 | * |
174 | * Returns: --- |
175 | * |
176 | * Use: Handles a string from an ident server. |
177 | */ |
178 | |
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179 | static void line(char *s, size_t len, void *p) |
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180 | { |
181 | ident_request *rq = p; |
182 | |
183 | rq->state = IDENT_DONE; |
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184 | close(rq->b.reader.fd); |
185 | if (!s) |
186 | rq->func(0, rq->p); |
187 | else { |
188 | ident_reply i; |
189 | parse(s, &i); |
190 | rq->func(&i, rq->p); |
191 | } |
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192 | selbuf_destroy(&rq->b); |
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193 | } |
194 | |
195 | /* --- @connected@ --- * |
196 | * |
197 | * Arguments: @int fd@ = file descriptor |
198 | * @void *p@ = pointer to request block |
199 | * |
200 | * Returns: --- |
201 | * |
202 | * Use: Handles a connection to a remote ident server. |
203 | */ |
204 | |
205 | static void connected(int fd, void *p) |
206 | { |
207 | ident_request *rq = p; |
208 | dstr d = DSTR_INIT; |
209 | |
210 | /* --- Handle an error during the connect --- */ |
211 | |
212 | if (fd < 0) |
213 | goto fail_0; |
214 | |
215 | /* --- Initialize the string to send to the remote host --- */ |
216 | |
217 | TRY { |
218 | dstr_putf(&d, "%u, %u\r\n", |
219 | ntohs(rq->remote.sin_port), ntohs(rq->local.sin_port)); |
220 | } CATCH switch (exc_type) { |
221 | case EXC_NOMEM: |
222 | EXIT_TRY; |
223 | goto fail_1; |
224 | default: |
225 | RETHROW; |
226 | } END_TRY; |
227 | |
228 | /* --- Do the rest of the work --- */ |
229 | |
230 | if (write(fd, d.buf, d.len) < d.len) |
231 | goto fail_1; |
232 | dstr_destroy(&d); |
233 | rq->state = IDENT_READ; |
234 | selbuf_init(&rq->b, rq->s, fd, line, rq); |
235 | return; |
236 | |
237 | /* --- Tidy up after misfortunes --- */ |
238 | |
239 | fail_1: |
240 | dstr_destroy(&d); |
241 | close(fd); |
242 | fail_0: |
243 | rq->state = IDENT_DONE; |
244 | rq->func(0, rq->p); |
245 | } |
246 | |
247 | /* --- @ident_abort@ --- * |
248 | * |
249 | * Arguments: @ident_request *rq@ = pointer to request block |
250 | * |
251 | * Returns: --- |
252 | * |
253 | * Use: Cancels an ident request in progress. |
254 | */ |
255 | |
256 | void ident_abort(ident_request *rq) |
257 | { |
258 | switch (rq->state) { |
259 | case IDENT_CONN: |
260 | conn_kill(&rq->c); |
261 | break; |
262 | case IDENT_READ: |
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263 | close(rq->b.reader.fd); |
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264 | selbuf_destroy(&rq->b); |
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265 | break; |
266 | } |
267 | } |
268 | |
269 | /* --- @go@ --- * |
270 | * |
271 | * Arguments: @ident_request *rq@ = pointer to request block |
272 | * |
273 | * Returns: --- |
274 | * |
275 | * Use: Starts a connection to the remote ident server. |
276 | */ |
277 | |
278 | static void go(ident_request *rq) |
279 | { |
280 | int fd; |
281 | struct sockaddr_in sin; |
282 | int opt; |
283 | |
284 | /* --- Create the socket I'll use --- */ |
285 | |
286 | if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0) |
287 | goto fail_0; |
288 | memset(&sin, 0, sizeof(sin)); |
289 | sin.sin_family = AF_INET; |
290 | sin.sin_port = 0; |
291 | sin.sin_addr = rq->local.sin_addr; |
292 | if (bind(fd, (struct sockaddr *)&sin, sizeof(sin))) |
293 | goto fail_1; |
294 | |
295 | /* --- Out-of-band data would confuse us --- */ |
296 | |
297 | opt = 1; |
298 | setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt)); |
299 | |
300 | /* --- Start a connection to the remote server --- */ |
301 | |
302 | sin.sin_family = AF_INET; |
303 | sin.sin_port = htons(113); |
304 | sin.sin_addr = rq->remote.sin_addr; |
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305 | if (conn_init(&rq->c, rq->s, fd, (struct sockaddr *)&sin, sizeof(sin), |
306 | connected, rq)) |
307 | goto fail_1; |
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308 | |
309 | /* --- Finish off initializing the block --- */ |
310 | |
311 | rq->state = IDENT_CONN; |
312 | return; |
313 | |
314 | /* --- Tidy up after lossage --- */ |
315 | |
316 | fail_1: |
317 | close(fd); |
318 | fail_0: |
319 | rq->state = IDENT_DONE; |
320 | rq->func(0, rq->p); |
321 | } |
322 | |
323 | /* --- @ident@ --- * |
324 | * |
325 | * Arguments: @ident_request *rq@ = pointer to request block |
326 | * @sel_state *s@ = I/O multiplexor |
327 | * @const struct sockaddr_in *local, *remote@ = addresses |
328 | * @void (*func)(ident_reply *i, void *p)@ = handler function |
329 | * @void *p@ = argument for handler |
330 | * |
331 | * Returns: --- |
332 | * |
333 | * Use: Initializes an ident request. |
334 | */ |
335 | |
336 | void ident(ident_request *rq, sel_state *s, |
337 | const struct sockaddr_in *local, |
338 | const struct sockaddr_in *remote, |
339 | void (*func)(ident_reply */*i*/, void */*p*/), |
340 | void *p) |
341 | { |
342 | memcpy(&rq->local, local, sizeof(rq->local)); |
343 | memcpy(&rq->remote, remote, sizeof(rq->remote)); |
344 | rq->func = func; |
345 | rq->p = p; |
346 | rq->s = s; |
347 | go(rq); |
348 | } |
349 | |
350 | /* --- @ident_socket@ --- * |
351 | * |
352 | * Arguments: @ident_request *rq@ = pointer to request block |
353 | * @sel_state *s@ = I/O multiplexor |
354 | * @int sk@ = connected socket file descriptor |
355 | * @void (*func)(ident_reply *i, void *p)@ = handler function |
356 | * @void *p@ = argument for handler |
357 | * |
358 | * Returns: --- |
359 | * |
360 | * Use: An alternative interface to @ident@. Initializes an ident |
361 | * request from a connected socket, rather than from an explicit |
362 | * address. This will call @getsockname@ and @getpeername@ to |
363 | * find out what the socket is actually connected to, which adds |
364 | * convenience but wastes time. |
365 | */ |
366 | |
367 | void ident_socket(ident_request *rq, sel_state *s, int sk, |
368 | void (*func)(ident_reply */*i*/, void */*p*/), |
369 | void *p) |
370 | { |
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371 | size_t sinsz; |
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372 | if ((sinsz = sizeof(struct sockaddr_in), |
373 | getsockname(sk, (struct sockaddr *)&rq->local, &sinsz)) || |
374 | (sinsz = sizeof(struct sockaddr_in), |
375 | getpeername(sk, (struct sockaddr *)&rq->remote, &sinsz))) { |
376 | rq->state = IDENT_DONE; |
377 | func(0, p); |
378 | return; |
379 | } |
380 | |
381 | rq->func = func; |
382 | rq->p = p; |
383 | rq->s = s; |
384 | go(rq); |
385 | } |
386 | |
387 | /*----- That's all, folks -------------------------------------------------*/ |