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1 | /* -*-c-*- |
2 | * |
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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" |
36188114 |
47 | #include "macros.h" |
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48 | #include "selbuf.h" |
49 | |
50 | /*----- Main code ---------------------------------------------------------*/ |
51 | |
52 | /* --- @next@ --- * |
53 | * |
54 | * Arguments: @char **pp@ = address of string pointer |
55 | * |
56 | * Returns: Address of next token. |
57 | * |
58 | * Use: Reads the next token from the result string. Tokens are |
59 | * terminated by whitespace, or `:' or `,' characters. The |
60 | * result string has had `\' escapes removed; it's stored in |
61 | * the same memory as the input string. The actual content |
62 | * of the delimiter doesn't seem to be interesting, so it |
63 | * gets thrown away. |
64 | */ |
65 | |
66 | static char *next(char **pp) |
67 | { |
68 | char *p, *q, *r; |
69 | |
70 | /* --- Deal with reads past the end of the string --- */ |
71 | |
72 | if (!*pp) |
73 | return (""); |
74 | |
75 | /* --- Initialize various pointers into the string --- */ |
76 | |
77 | p = q = r = *pp; |
78 | |
79 | /* --- Skip past any leading whitespace --- */ |
80 | |
36188114 |
81 | while (ISSPACE(*p)) |
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82 | p++; |
83 | |
84 | /* --- Now start work on the string itself --- */ |
85 | |
86 | for (;;) { |
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87 | if (*p == 0 || *p == ':' || *p == ',' || ISSPACE(*p)) |
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88 | break; |
89 | else if (*p == '\\') { |
90 | p++; |
91 | if (!*p) { |
92 | *q++ = '\\'; |
93 | break; |
94 | } |
95 | } |
96 | *q++ = *p++; |
97 | } |
98 | |
99 | /* --- Tidy up afterwards --- */ |
100 | |
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101 | while (ISSPACE(*p)) |
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102 | p++; |
103 | if (*p == 0) |
104 | *pp = 0; |
105 | else if (*p == ':' || *p == ',') |
106 | *pp = p + 1; |
107 | else |
108 | *pp = p; |
109 | *q = 0; |
110 | |
111 | return (r); |
112 | } |
113 | |
114 | /* --- @parse@ --- * |
115 | * |
116 | * Arguments: @char *p@ = pointer to input string from identd |
117 | * @ident_reply *i@ = pointer to output block |
118 | * |
119 | * Returns: --- |
120 | * |
121 | * Use: Parses a result string from an RFC931 (identd) server. |
122 | */ |
123 | |
124 | static void parse(char *p, ident_reply *i) |
125 | { |
126 | char *q; |
127 | |
128 | /* --- Read the source and destination port numbers --- */ |
129 | |
130 | i->sport = atoi(next(&p)); |
131 | i->dport = atoi(next(&p)); |
132 | |
133 | /* --- Find out what sort of a reply this is --- */ |
134 | |
135 | q = next(&p); |
36188114 |
136 | if (STRCMP(q, ==, "USERID")) { |
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137 | i->type = IDENT_USERID; |
138 | i->u.userid.os = next(&p); |
139 | i->u.userid.user = next(&p); |
36188114 |
140 | } else if (STRCMP(q, ==, "ERROR")) { |
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141 | i->type = IDENT_ERROR; |
142 | i->u.error = next(&p); |
143 | } else |
144 | i->type = IDENT_BAD; |
145 | } |
146 | |
147 | /* --- @line@ --- * |
148 | * |
149 | * Arguments: @char *s@ = pointer to string from ident server |
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150 | * @size_t len@ = length of the line |
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151 | * @void *p@ = pointer to my request block |
152 | * |
153 | * Returns: --- |
154 | * |
155 | * Use: Handles a string from an ident server. |
156 | */ |
157 | |
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158 | static void line(char *s, size_t len, void *p) |
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159 | { |
160 | ident_request *rq = p; |
161 | |
162 | rq->state = IDENT_DONE; |
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163 | close(rq->b.reader.fd); |
164 | if (!s) |
165 | rq->func(0, rq->p); |
166 | else { |
167 | ident_reply i; |
168 | parse(s, &i); |
169 | rq->func(&i, rq->p); |
170 | } |
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171 | selbuf_destroy(&rq->b); |
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172 | } |
173 | |
174 | /* --- @connected@ --- * |
175 | * |
176 | * Arguments: @int fd@ = file descriptor |
177 | * @void *p@ = pointer to request block |
178 | * |
179 | * Returns: --- |
180 | * |
181 | * Use: Handles a connection to a remote ident server. |
182 | */ |
183 | |
184 | static void connected(int fd, void *p) |
185 | { |
186 | ident_request *rq = p; |
187 | dstr d = DSTR_INIT; |
188 | |
189 | /* --- Handle an error during the connect --- */ |
190 | |
191 | if (fd < 0) |
192 | goto fail_0; |
193 | |
194 | /* --- Initialize the string to send to the remote host --- */ |
195 | |
196 | TRY { |
197 | dstr_putf(&d, "%u, %u\r\n", |
198 | ntohs(rq->remote.sin_port), ntohs(rq->local.sin_port)); |
199 | } CATCH switch (exc_type) { |
200 | case EXC_NOMEM: |
201 | EXIT_TRY; |
202 | goto fail_1; |
203 | default: |
204 | RETHROW; |
205 | } END_TRY; |
206 | |
207 | /* --- Do the rest of the work --- */ |
208 | |
209 | if (write(fd, d.buf, d.len) < d.len) |
210 | goto fail_1; |
211 | dstr_destroy(&d); |
212 | rq->state = IDENT_READ; |
213 | selbuf_init(&rq->b, rq->s, fd, line, rq); |
214 | return; |
215 | |
216 | /* --- Tidy up after misfortunes --- */ |
217 | |
218 | fail_1: |
219 | dstr_destroy(&d); |
220 | close(fd); |
221 | fail_0: |
222 | rq->state = IDENT_DONE; |
223 | rq->func(0, rq->p); |
224 | } |
225 | |
226 | /* --- @ident_abort@ --- * |
227 | * |
228 | * Arguments: @ident_request *rq@ = pointer to request block |
229 | * |
230 | * Returns: --- |
231 | * |
232 | * Use: Cancels an ident request in progress. |
233 | */ |
234 | |
235 | void ident_abort(ident_request *rq) |
236 | { |
237 | switch (rq->state) { |
238 | case IDENT_CONN: |
239 | conn_kill(&rq->c); |
240 | break; |
241 | case IDENT_READ: |
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242 | close(rq->b.reader.fd); |
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243 | selbuf_destroy(&rq->b); |
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244 | break; |
245 | } |
246 | } |
247 | |
248 | /* --- @go@ --- * |
249 | * |
250 | * Arguments: @ident_request *rq@ = pointer to request block |
251 | * |
252 | * Returns: --- |
253 | * |
254 | * Use: Starts a connection to the remote ident server. |
255 | */ |
256 | |
257 | static void go(ident_request *rq) |
258 | { |
259 | int fd; |
260 | struct sockaddr_in sin; |
261 | int opt; |
262 | |
263 | /* --- Create the socket I'll use --- */ |
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264 | |
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265 | if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0) |
266 | goto fail_0; |
267 | memset(&sin, 0, sizeof(sin)); |
268 | sin.sin_family = AF_INET; |
269 | sin.sin_port = 0; |
270 | sin.sin_addr = rq->local.sin_addr; |
271 | if (bind(fd, (struct sockaddr *)&sin, sizeof(sin))) |
272 | goto fail_1; |
273 | |
274 | /* --- Out-of-band data would confuse us --- */ |
275 | |
276 | opt = 1; |
277 | setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt)); |
278 | |
279 | /* --- Start a connection to the remote server --- */ |
280 | |
281 | sin.sin_family = AF_INET; |
282 | sin.sin_port = htons(113); |
283 | sin.sin_addr = rq->remote.sin_addr; |
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284 | if (conn_init(&rq->c, rq->s, fd, (struct sockaddr *)&sin, sizeof(sin), |
285 | connected, rq)) |
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286 | goto fail_0; |
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287 | |
288 | /* --- Finish off initializing the block --- */ |
289 | |
290 | rq->state = IDENT_CONN; |
291 | return; |
292 | |
293 | /* --- Tidy up after lossage --- */ |
294 | |
295 | fail_1: |
296 | close(fd); |
297 | fail_0: |
298 | rq->state = IDENT_DONE; |
299 | rq->func(0, rq->p); |
300 | } |
301 | |
302 | /* --- @ident@ --- * |
303 | * |
304 | * Arguments: @ident_request *rq@ = pointer to request block |
305 | * @sel_state *s@ = I/O multiplexor |
306 | * @const struct sockaddr_in *local, *remote@ = addresses |
307 | * @void (*func)(ident_reply *i, void *p)@ = handler function |
308 | * @void *p@ = argument for handler |
309 | * |
310 | * Returns: --- |
311 | * |
312 | * Use: Initializes an ident request. |
313 | */ |
314 | |
315 | void ident(ident_request *rq, sel_state *s, |
316 | const struct sockaddr_in *local, |
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317 | const struct sockaddr_in *remote, |
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318 | void (*func)(ident_reply */*i*/, void */*p*/), |
319 | void *p) |
320 | { |
321 | memcpy(&rq->local, local, sizeof(rq->local)); |
322 | memcpy(&rq->remote, remote, sizeof(rq->remote)); |
323 | rq->func = func; |
324 | rq->p = p; |
325 | rq->s = s; |
326 | go(rq); |
327 | } |
328 | |
329 | /* --- @ident_socket@ --- * |
330 | * |
331 | * Arguments: @ident_request *rq@ = pointer to request block |
332 | * @sel_state *s@ = I/O multiplexor |
333 | * @int sk@ = connected socket file descriptor |
334 | * @void (*func)(ident_reply *i, void *p)@ = handler function |
335 | * @void *p@ = argument for handler |
336 | * |
337 | * Returns: --- |
338 | * |
339 | * Use: An alternative interface to @ident@. Initializes an ident |
340 | * request from a connected socket, rather than from an explicit |
341 | * address. This will call @getsockname@ and @getpeername@ to |
342 | * find out what the socket is actually connected to, which adds |
343 | * convenience but wastes time. |
344 | */ |
345 | |
346 | void ident_socket(ident_request *rq, sel_state *s, int sk, |
347 | void (*func)(ident_reply */*i*/, void */*p*/), |
348 | void *p) |
349 | { |
0ce34834 |
350 | socklen_t sinsz; |
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351 | if ((sinsz = sizeof(struct sockaddr_in), |
352 | getsockname(sk, (struct sockaddr *)&rq->local, &sinsz)) || |
353 | (sinsz = sizeof(struct sockaddr_in), |
354 | getpeername(sk, (struct sockaddr *)&rq->remote, &sinsz))) { |
355 | rq->state = IDENT_DONE; |
356 | func(0, p); |
357 | return; |
358 | } |
359 | |
360 | rq->func = func; |
361 | rq->p = p; |
362 | rq->s = s; |
363 | go(rq); |
364 | } |
365 | |
366 | /*----- That's all, folks -------------------------------------------------*/ |