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1 | /* -*-c-*- |
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2 | * |
3 | * Nonblocking RFC931 client |
4 | * |
5 | * (c) 1999 Mark Wooding |
6 | */ |
7 | |
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8 | /*----- Licensing notice --------------------------------------------------* |
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9 | * |
10 | * This file is part of the mLib utilities library. |
11 | * |
12 | * mLib is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU Library General Public License as |
14 | * published by the Free Software Foundation; either version 2 of the |
15 | * License, or (at your option) any later version. |
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16 | * |
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17 | * mLib is distributed in the hope that it will be useful, |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
20 | * GNU Library General Public License for more details. |
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21 | * |
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22 | * You should have received a copy of the GNU Library General Public |
23 | * License along with mLib; if not, write to the Free |
24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
25 | * MA 02111-1307, USA. |
26 | */ |
27 | |
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28 | /*----- Header files ------------------------------------------------------*/ |
29 | |
30 | #include <ctype.h> |
31 | #include <stdio.h> |
32 | #include <stdlib.h> |
33 | #include <string.h> |
34 | |
35 | #include <sys/types.h> |
36 | #include <unistd.h> |
37 | |
38 | #include <sys/socket.h> |
39 | #include <netinet/in.h> |
40 | #include <arpa/inet.h> |
41 | #include <netdb.h> |
42 | |
43 | #include "conn.h" |
44 | #include "dstr.h" |
45 | #include "exc.h" |
46 | #include "ident.h" |
47 | #include "selbuf.h" |
48 | |
49 | /*----- Main code ---------------------------------------------------------*/ |
50 | |
51 | /* --- @next@ --- * |
52 | * |
53 | * Arguments: @char **pp@ = address of string pointer |
54 | * |
55 | * Returns: Address of next token. |
56 | * |
57 | * Use: Reads the next token from the result string. Tokens are |
58 | * terminated by whitespace, or `:' or `,' characters. The |
59 | * result string has had `\' escapes removed; it's stored in |
60 | * the same memory as the input string. The actual content |
61 | * of the delimiter doesn't seem to be interesting, so it |
62 | * gets thrown away. |
63 | */ |
64 | |
65 | static char *next(char **pp) |
66 | { |
67 | char *p, *q, *r; |
68 | |
69 | /* --- Deal with reads past the end of the string --- */ |
70 | |
71 | if (!*pp) |
72 | return (""); |
73 | |
74 | /* --- Initialize various pointers into the string --- */ |
75 | |
76 | p = q = r = *pp; |
77 | |
78 | /* --- Skip past any leading whitespace --- */ |
79 | |
80 | while (isspace((unsigned char)*p)) |
81 | p++; |
82 | |
83 | /* --- Now start work on the string itself --- */ |
84 | |
85 | for (;;) { |
86 | if (*p == 0 || *p == ':' || *p == ',' || isspace((unsigned char)*p)) |
87 | break; |
88 | else if (*p == '\\') { |
89 | p++; |
90 | if (!*p) { |
91 | *q++ = '\\'; |
92 | break; |
93 | } |
94 | } |
95 | *q++ = *p++; |
96 | } |
97 | |
98 | /* --- Tidy up afterwards --- */ |
99 | |
100 | while (isspace((unsigned char)*p)) |
101 | p++; |
102 | if (*p == 0) |
103 | *pp = 0; |
104 | else if (*p == ':' || *p == ',') |
105 | *pp = p + 1; |
106 | else |
107 | *pp = p; |
108 | *q = 0; |
109 | |
110 | return (r); |
111 | } |
112 | |
113 | /* --- @parse@ --- * |
114 | * |
115 | * Arguments: @char *p@ = pointer to input string from identd |
116 | * @ident_reply *i@ = pointer to output block |
117 | * |
118 | * Returns: --- |
119 | * |
120 | * Use: Parses a result string from an RFC931 (identd) server. |
121 | */ |
122 | |
123 | static void parse(char *p, ident_reply *i) |
124 | { |
125 | char *q; |
126 | |
127 | /* --- Read the source and destination port numbers --- */ |
128 | |
129 | i->sport = atoi(next(&p)); |
130 | i->dport = atoi(next(&p)); |
131 | |
132 | /* --- Find out what sort of a reply this is --- */ |
133 | |
134 | q = next(&p); |
135 | if (strcmp(q, "USERID") == 0) { |
136 | i->type = IDENT_USERID; |
137 | i->u.userid.os = next(&p); |
138 | i->u.userid.user = next(&p); |
139 | } else if (strcmp(q, "ERROR") == 0) { |
140 | i->type = IDENT_ERROR; |
141 | i->u.error = next(&p); |
142 | } else |
143 | i->type = IDENT_BAD; |
144 | } |
145 | |
146 | /* --- @line@ --- * |
147 | * |
148 | * Arguments: @char *s@ = pointer to string from ident server |
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149 | * @size_t len@ = length of the line |
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150 | * @void *p@ = pointer to my request block |
151 | * |
152 | * Returns: --- |
153 | * |
154 | * Use: Handles a string from an ident server. |
155 | */ |
156 | |
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157 | static void line(char *s, size_t len, void *p) |
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158 | { |
159 | ident_request *rq = p; |
160 | |
161 | rq->state = IDENT_DONE; |
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162 | close(rq->b.reader.fd); |
163 | if (!s) |
164 | rq->func(0, rq->p); |
165 | else { |
166 | ident_reply i; |
167 | parse(s, &i); |
168 | rq->func(&i, rq->p); |
169 | } |
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170 | selbuf_destroy(&rq->b); |
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171 | } |
172 | |
173 | /* --- @connected@ --- * |
174 | * |
175 | * Arguments: @int fd@ = file descriptor |
176 | * @void *p@ = pointer to request block |
177 | * |
178 | * Returns: --- |
179 | * |
180 | * Use: Handles a connection to a remote ident server. |
181 | */ |
182 | |
183 | static void connected(int fd, void *p) |
184 | { |
185 | ident_request *rq = p; |
186 | dstr d = DSTR_INIT; |
187 | |
188 | /* --- Handle an error during the connect --- */ |
189 | |
190 | if (fd < 0) |
191 | goto fail_0; |
192 | |
193 | /* --- Initialize the string to send to the remote host --- */ |
194 | |
195 | TRY { |
196 | dstr_putf(&d, "%u, %u\r\n", |
197 | ntohs(rq->remote.sin_port), ntohs(rq->local.sin_port)); |
198 | } CATCH switch (exc_type) { |
199 | case EXC_NOMEM: |
200 | EXIT_TRY; |
201 | goto fail_1; |
202 | default: |
203 | RETHROW; |
204 | } END_TRY; |
205 | |
206 | /* --- Do the rest of the work --- */ |
207 | |
208 | if (write(fd, d.buf, d.len) < d.len) |
209 | goto fail_1; |
210 | dstr_destroy(&d); |
211 | rq->state = IDENT_READ; |
212 | selbuf_init(&rq->b, rq->s, fd, line, rq); |
213 | return; |
214 | |
215 | /* --- Tidy up after misfortunes --- */ |
216 | |
217 | fail_1: |
218 | dstr_destroy(&d); |
219 | close(fd); |
220 | fail_0: |
221 | rq->state = IDENT_DONE; |
222 | rq->func(0, rq->p); |
223 | } |
224 | |
225 | /* --- @ident_abort@ --- * |
226 | * |
227 | * Arguments: @ident_request *rq@ = pointer to request block |
228 | * |
229 | * Returns: --- |
230 | * |
231 | * Use: Cancels an ident request in progress. |
232 | */ |
233 | |
234 | void ident_abort(ident_request *rq) |
235 | { |
236 | switch (rq->state) { |
237 | case IDENT_CONN: |
238 | conn_kill(&rq->c); |
239 | break; |
240 | case IDENT_READ: |
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241 | close(rq->b.reader.fd); |
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242 | selbuf_destroy(&rq->b); |
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243 | break; |
244 | } |
245 | } |
246 | |
247 | /* --- @go@ --- * |
248 | * |
249 | * Arguments: @ident_request *rq@ = pointer to request block |
250 | * |
251 | * Returns: --- |
252 | * |
253 | * Use: Starts a connection to the remote ident server. |
254 | */ |
255 | |
256 | static void go(ident_request *rq) |
257 | { |
258 | int fd; |
259 | struct sockaddr_in sin; |
260 | int opt; |
261 | |
262 | /* --- Create the socket I'll use --- */ |
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263 | |
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264 | if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0) |
265 | goto fail_0; |
266 | memset(&sin, 0, sizeof(sin)); |
267 | sin.sin_family = AF_INET; |
268 | sin.sin_port = 0; |
269 | sin.sin_addr = rq->local.sin_addr; |
270 | if (bind(fd, (struct sockaddr *)&sin, sizeof(sin))) |
271 | goto fail_1; |
272 | |
273 | /* --- Out-of-band data would confuse us --- */ |
274 | |
275 | opt = 1; |
276 | setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt)); |
277 | |
278 | /* --- Start a connection to the remote server --- */ |
279 | |
280 | sin.sin_family = AF_INET; |
281 | sin.sin_port = htons(113); |
282 | sin.sin_addr = rq->remote.sin_addr; |
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283 | if (conn_init(&rq->c, rq->s, fd, (struct sockaddr *)&sin, sizeof(sin), |
284 | connected, rq)) |
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285 | goto fail_0; |
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286 | |
287 | /* --- Finish off initializing the block --- */ |
288 | |
289 | rq->state = IDENT_CONN; |
290 | return; |
291 | |
292 | /* --- Tidy up after lossage --- */ |
293 | |
294 | fail_1: |
295 | close(fd); |
296 | fail_0: |
297 | rq->state = IDENT_DONE; |
298 | rq->func(0, rq->p); |
299 | } |
300 | |
301 | /* --- @ident@ --- * |
302 | * |
303 | * Arguments: @ident_request *rq@ = pointer to request block |
304 | * @sel_state *s@ = I/O multiplexor |
305 | * @const struct sockaddr_in *local, *remote@ = addresses |
306 | * @void (*func)(ident_reply *i, void *p)@ = handler function |
307 | * @void *p@ = argument for handler |
308 | * |
309 | * Returns: --- |
310 | * |
311 | * Use: Initializes an ident request. |
312 | */ |
313 | |
314 | void ident(ident_request *rq, sel_state *s, |
315 | const struct sockaddr_in *local, |
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316 | const struct sockaddr_in *remote, |
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317 | void (*func)(ident_reply */*i*/, void */*p*/), |
318 | void *p) |
319 | { |
320 | memcpy(&rq->local, local, sizeof(rq->local)); |
321 | memcpy(&rq->remote, remote, sizeof(rq->remote)); |
322 | rq->func = func; |
323 | rq->p = p; |
324 | rq->s = s; |
325 | go(rq); |
326 | } |
327 | |
328 | /* --- @ident_socket@ --- * |
329 | * |
330 | * Arguments: @ident_request *rq@ = pointer to request block |
331 | * @sel_state *s@ = I/O multiplexor |
332 | * @int sk@ = connected socket file descriptor |
333 | * @void (*func)(ident_reply *i, void *p)@ = handler function |
334 | * @void *p@ = argument for handler |
335 | * |
336 | * Returns: --- |
337 | * |
338 | * Use: An alternative interface to @ident@. Initializes an ident |
339 | * request from a connected socket, rather than from an explicit |
340 | * address. This will call @getsockname@ and @getpeername@ to |
341 | * find out what the socket is actually connected to, which adds |
342 | * convenience but wastes time. |
343 | */ |
344 | |
345 | void ident_socket(ident_request *rq, sel_state *s, int sk, |
346 | void (*func)(ident_reply */*i*/, void */*p*/), |
347 | void *p) |
348 | { |
0ce34834 |
349 | socklen_t sinsz; |
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350 | if ((sinsz = sizeof(struct sockaddr_in), |
351 | getsockname(sk, (struct sockaddr *)&rq->local, &sinsz)) || |
352 | (sinsz = sizeof(struct sockaddr_in), |
353 | getpeername(sk, (struct sockaddr *)&rq->remote, &sinsz))) { |
354 | rq->state = IDENT_DONE; |
355 | func(0, p); |
356 | return; |
357 | } |
358 | |
359 | rq->func = func; |
360 | rq->p = p; |
361 | rq->s = s; |
362 | go(rq); |
363 | } |
364 | |
365 | /*----- That's all, folks -------------------------------------------------*/ |