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