Commit | Line | Data |
---|---|---|
14d7100d | 1 | /* -*-c-*- |
2 | * | |
1dc93196 | 3 | * $Id$ |
14d7100d | 4 | * |
5 | * Background reverse name resolution (ADNS version) | |
6 | * | |
7 | * (c) 2003 Straylight/Edgeware | |
8 | */ | |
9 | ||
d4efbcd9 | 10 | /*----- Licensing notice --------------------------------------------------* |
14d7100d | 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. | |
d4efbcd9 | 18 | * |
14d7100d | 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. | |
d4efbcd9 | 23 | * |
14d7100d | 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 | * HOWEVER, since GNU adns is covered by the full GNU General Public | |
31 | * License, this file (only) is also covered by the full GNU GPL, and | |
32 | * you may NOT take advantage of the more liberal conditions of the | |
33 | * LGPL when modifying or redistributing this file. This doesn't mean | |
34 | * that a program which uses the interface provided by this file is | |
35 | * covered by the GPL, since @bres.c@ provides the same interface and | |
36 | * is LGPL. However, it does mean that if your program depends, for | |
37 | * some reason (e.g., to meet particular performance criteria), on | |
38 | * this adns-based implementation of mLib's background resolver then it | |
39 | * must be licensed under the full GPL. | |
40 | */ | |
41 | ||
a0150d8d MW |
42 | #include "config.h" |
43 | ||
14d7100d | 44 | #ifndef HAVE_ADNS |
45 | # error "You need the ADNS library to compile this file." | |
46 | #endif | |
47 | ||
48 | /*----- Header files ------------------------------------------------------*/ | |
49 | ||
50 | #include <assert.h> | |
51 | #include <errno.h> | |
52 | #include <signal.h> | |
53 | #include <stdio.h> | |
54 | #include <stdlib.h> | |
55 | #include <string.h> | |
56 | ||
57 | #include <sys/types.h> | |
58 | #include <sys/time.h> | |
59 | #include <unistd.h> | |
60 | #include <sys/wait.h> | |
61 | ||
62 | #include <sys/socket.h> | |
63 | #include <netinet/in.h> | |
64 | #include <arpa/inet.h> | |
65 | #include <netdb.h> | |
66 | ||
67 | #include <adns.h> | |
68 | ||
69 | #include "alloc.h" | |
70 | #include "bres.h" | |
71 | #include "macros.h" | |
72 | #include "report.h" | |
73 | #include "sel.h" | |
74 | ||
75 | /*----- Static variables --------------------------------------------------*/ | |
76 | ||
77 | static adns_state ads; | |
78 | static sel_state *sel; | |
79 | static sel_hook selhook; | |
80 | ||
81 | /*----- Main code ---------------------------------------------------------*/ | |
82 | ||
83 | /* --- @bres_abort@ --- * | |
84 | * | |
85 | * Arguments: @bres_client *rc@ = pointer to client block | |
86 | * | |
87 | * Returns: --- | |
88 | * | |
89 | * Use: Removes a queued job. | |
90 | */ | |
91 | ||
92 | void bres_abort(bres_client *rc) | |
93 | { | |
94 | if (rc->q == adns_r_addr) xfree(rc->u.name); | |
95 | if (rc->a) free(rc->a); | |
96 | adns_cancel(rc->aq); | |
97 | } | |
98 | ||
99 | /* --- @bres_byaddr@ --- * | |
100 | * | |
101 | * Arguments: @bres_client *rc@ = pointer to client block | |
102 | * @struct in_addr addr@ = address to resolve | |
103 | * @void (*func)(struct hostent *h, void *p)@ = handler function | |
104 | * @void *p@ = argument for handler function | |
105 | * | |
106 | * Returns: --- | |
107 | * | |
108 | * Use: Adds an address lookup job to the queue. The job will be | |
109 | * processed when there's a spare resolver process to deal with | |
110 | * it. | |
111 | */ | |
112 | ||
113 | void bres_byaddr(bres_client *rc, struct in_addr addr, | |
114 | void (*func)(struct hostent */*h*/, void */*p*/), | |
115 | void *p) | |
116 | { | |
117 | int e; | |
118 | struct sockaddr_in sin; | |
119 | ||
120 | if (!ads) goto fail; | |
121 | sin.sin_family = AF_INET; | |
122 | sin.sin_addr = addr; | |
123 | sin.sin_port = 0; | |
124 | if ((e = adns_submit_reverse(ads, (struct sockaddr *)&sin, adns_r_ptr, | |
125 | 0, rc, &rc->aq)) != 0) | |
126 | goto fail; | |
127 | rc->a = 0; | |
128 | rc->q = adns_r_ptr; | |
129 | rc->u.addr = addr; | |
130 | rc->func = func; | |
131 | rc->p = p; | |
132 | return; | |
133 | ||
134 | fail: | |
135 | func(0, p); | |
136 | } | |
137 | ||
138 | /* --- @bres_byname@ --- * | |
139 | * | |
140 | * Arguments: @bres_client *rc@ = pointer to client block | |
141 | * @const char *name@ = name to resolve | |
142 | * @void (*func)(struct hostent *h, void *p)@ = handler function | |
143 | * @void *p@ = argument for handler function | |
144 | * | |
145 | * Returns: --- | |
146 | * | |
147 | * Use: Adds a name lookup job to the queue. The job will be | |
148 | * processed when there's a spare resolver process to deal with | |
149 | * it. | |
150 | */ | |
151 | ||
152 | void bres_byname(bres_client *rc, const char *name, | |
153 | void (*func)(struct hostent */*h*/, void */*p*/), | |
154 | void *p) | |
155 | { | |
156 | int e; | |
157 | ||
158 | if (!ads) goto fail; | |
159 | if ((e = adns_submit(ads, name, adns_r_addr, | |
4f6d400b | 160 | adns_qf_search | adns_qf_owner, rc, &rc->aq)) != 0) |
14d7100d | 161 | goto fail; |
162 | rc->a = 0; | |
163 | rc->q = adns_r_addr; | |
164 | rc->u.name = xstrdup(name); | |
165 | rc->func = func; | |
166 | rc->p = p; | |
167 | return; | |
168 | ||
169 | fail: | |
170 | func(0, p); | |
171 | } | |
172 | ||
173 | /* --- @bres_exec@ --- * | |
174 | * | |
175 | * Arguments: @const char *file@ = file containing server code or null | |
176 | * | |
177 | * Returns: --- | |
178 | * | |
179 | * Use: Makes `bres' use a standalone server rather than copies of | |
180 | * the current process. This can reduce memory consumption for | |
181 | * large processes, at the expense of startup time (which | |
182 | * shouldn't be too bad anyway, because of the resolver design). | |
183 | * If the filename is null, a default set up at install time is | |
184 | * used. It's probably a good idea to leave it alone. | |
185 | */ | |
186 | ||
187 | void bres_exec(const char *file) | |
188 | { | |
189 | /* Nothin' doin' */ | |
190 | } | |
191 | ||
192 | /* --- @report@ --- * | |
193 | * | |
194 | * Arguments: @bres_client *c@ = client descriptor block | |
195 | * @adns_answer *a@ = A-record answer from resolver library | |
196 | * @adns_rr_addr *av@ = vector of address records | |
197 | * @int an@ = number of address records (must be positive) | |
198 | * @char **nv@ = vector of name strings | |
199 | * @int nn@ = number of name strings (must be positive) | |
200 | * | |
201 | * Returns: --- | |
202 | * | |
203 | * Use: Formats the given answer into a @struct hostent@ and reports | |
204 | * it to the waiting client application. | |
205 | */ | |
206 | ||
207 | static void report(bres_client *rc, adns_answer *a, | |
208 | adns_rr_addr *av, int an, | |
209 | char **nv, int nn) | |
210 | { | |
211 | struct hostent h; | |
212 | char *n[16]; | |
213 | char *aa[16]; | |
214 | int i, j; | |
215 | ||
216 | j = 0; | |
217 | if (a->cname) n[j++] = a->cname; | |
218 | else { n[j++] = *nv; nv++; nn--; } | |
219 | for (i = 0; i < nn && j < N(n) - 1; i++) | |
220 | if (strcmp(n[0], nv[i]) != 0) n[j++] = nv[i]; | |
221 | n[j++] = 0; | |
222 | for (i = j = 0; i < an && j < N(av) - 1; i++) { | |
223 | if (av[i].addr.sa.sa_family == AF_INET) | |
224 | aa[j++] = (char *)&av[i].addr.inet.sin_addr; | |
225 | } | |
226 | aa[j++] = 0; | |
227 | h.h_name = n[0]; | |
228 | h.h_aliases = n + 1; | |
229 | h.h_addrtype = AF_INET; | |
230 | h.h_length = sizeof(struct in_addr); | |
231 | h.h_addr_list = aa; | |
d4efbcd9 | 232 | rc->func(&h, rc->p); |
14d7100d | 233 | } |
234 | ||
235 | /* --- @beforehook@, @afterhook@ --- * | |
236 | * | |
237 | * Arguments: @sel_state *s@ = select state | |
238 | * @sel_args *sa@ = argument block | |
239 | * @void *p@ = uninteresting pointer | |
240 | * | |
241 | * Returns: --- | |
242 | * | |
243 | * Use: Processes the selector's arguments before @select@ is | |
244 | * called, to allow ADNS to do its thing. | |
245 | */ | |
246 | ||
247 | static void beforehook(sel_state *s, sel_args *sa, void *p) | |
248 | { | |
249 | adns_beforeselect(ads, &sa->maxfd, | |
250 | &sa->fd[SEL_READ], &sa->fd[SEL_WRITE], &sa->fd[SEL_EXC], | |
251 | &sa->tvp, &sa->tv, &sa->now); | |
252 | } | |
253 | ||
254 | static void afterhook(sel_state *s, sel_args *sa, void *p) | |
255 | { | |
256 | void *c; | |
257 | bres_client *rc; | |
258 | adns_query q; | |
24a657cc | 259 | adns_answer *a, *aa; |
14d7100d | 260 | int e; |
261 | int i; | |
262 | ||
263 | adns_afterselect(ads, sa->maxfd, | |
264 | &sa->fd[SEL_READ], &sa->fd[SEL_WRITE], &sa->fd[SEL_EXC], | |
265 | &sa->now); | |
266 | while (q = 0, (e = adns_check(ads, &q, &a, &c)) == 0) { | |
267 | rc = c; | |
268 | if (a->status != 0) | |
269 | goto fail; | |
270 | else switch (rc->q) { | |
271 | case adns_r_addr: | |
272 | assert(a->type == adns_r_addr); | |
1dc93196 | 273 | xfree(rc->u.name); |
24a657cc | 274 | report(rc, a, a->rrs.addr, a->nrrs, &a->owner, 1); |
14d7100d | 275 | free(a); |
276 | break; | |
277 | case adns_r_ptr: | |
278 | if (a->type == adns_r_ptr) { | |
279 | rc->a = a; | |
280 | if ((e = adns_submit(ads, a->rrs.str[0], adns_r_addr, | |
281 | 0, rc, &q)) != 0) | |
282 | goto fail; | |
283 | rc->aq = q; | |
284 | } else { | |
285 | assert(a->type == adns_r_addr); | |
286 | for (i = 0; i < a->nrrs; i++) { | |
287 | if (a->rrs.addr[i].addr.sa.sa_family == AF_INET && | |
288 | a->rrs.addr[i].addr.inet.sin_addr.s_addr == | |
289 | rc->u.addr.s_addr) | |
290 | goto match; | |
291 | } | |
292 | goto fail; | |
293 | match: | |
24a657cc | 294 | aa = rc->a; |
295 | report(rc, a, &a->rrs.addr[i], 1, aa->rrs.str, aa->nrrs); | |
296 | free(aa); | |
14d7100d | 297 | free(a); |
298 | } | |
299 | break; | |
300 | default: | |
301 | abort(); | |
302 | } | |
303 | continue; | |
304 | ||
305 | fail: | |
14d7100d | 306 | if (rc->q == adns_r_addr) xfree(rc->u.name); |
307 | if (rc->a) free(rc->a); | |
24a657cc | 308 | rc->func(0, rc->p); |
14d7100d | 309 | free(a); |
310 | } | |
311 | } | |
312 | ||
313 | /* --- @bres_init@ --- * | |
314 | * | |
315 | * Arguments: @sel_state *s@ = pointer to select multiplexor | |
316 | * | |
317 | * Returns: --- | |
318 | * | |
319 | * Use: Initializes the background resolver for use. | |
320 | */ | |
321 | ||
322 | void bres_init(sel_state *s) | |
323 | { | |
324 | int e; | |
325 | ||
d46d1a2f | 326 | if ((e = adns_init(&ads, adns_if_noautosys, 0)) != 0) { |
14d7100d | 327 | moan("adns_init failed: resolver won't work"); |
328 | return; | |
329 | } | |
330 | sel_addhook(s, &selhook, beforehook, afterhook, 0); | |
331 | sel = s; | |
332 | } | |
333 | ||
334 | /*----- That's all, folks -------------------------------------------------*/ |