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