chiark / gitweb /
Test universal hashing and fix bugs.
[mLib] / ident.c
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7bd2091e 1/* -*-c-*-
2 *
b342b114 3 * $Id: ident.c,v 1.5 2002/01/13 13:33:15 mdw Exp $
7bd2091e 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 $
b342b114 33 * Revision 1.5 2002/01/13 13:33:15 mdw
34 * Track interface change for @lbuf@.
35 *
e569f554 36 * Revision 1.4 2001/06/22 19:35:39 mdw
37 * New @conn_init@ interface.
38 *
a0751c36 39 * Revision 1.3 2000/10/08 11:17:45 mdw
40 * (ident_socket): change sizes to be @size_t@.
41 *
e2a18bd0 42 * Revision 1.2 2000/06/17 10:38:35 mdw
43 * Track changes to selbuf interface.
44 *
7bd2091e 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
87static 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
145static 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
b342b114 171 * @size_t len@ = length of the line
7bd2091e 172 * @void *p@ = pointer to my request block
173 *
174 * Returns: ---
175 *
176 * Use: Handles a string from an ident server.
177 */
178
b342b114 179static void line(char *s, size_t len, void *p)
7bd2091e 180{
181 ident_request *rq = p;
182
183 rq->state = IDENT_DONE;
7bd2091e 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 }
e2a18bd0 192 selbuf_destroy(&rq->b);
7bd2091e 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
205static 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
239fail_1:
240 dstr_destroy(&d);
241 close(fd);
242fail_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
256void 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:
7bd2091e 263 close(rq->b.reader.fd);
e2a18bd0 264 selbuf_destroy(&rq->b);
7bd2091e 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
278static 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;
e569f554 305 if (conn_init(&rq->c, rq->s, fd, (struct sockaddr *)&sin, sizeof(sin),
306 connected, rq))
307 goto fail_1;
7bd2091e 308
309 /* --- Finish off initializing the block --- */
310
311 rq->state = IDENT_CONN;
312 return;
313
314 /* --- Tidy up after lossage --- */
315
316fail_1:
317 close(fd);
318fail_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
336void 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
367void ident_socket(ident_request *rq, sel_state *s, int sk,
368 void (*func)(ident_reply */*i*/, void */*p*/),
369 void *p)
370{
a0751c36 371 size_t sinsz;
7bd2091e 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 -------------------------------------------------*/