Commit | Line | Data |
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14d7100d | 1 | /* -*-c-*- |
14d7100d | 2 | * |
3 | * Background reverse name resolution (ADNS version) | |
4 | * | |
5 | * (c) 2003 Straylight/Edgeware | |
6 | */ | |
7 | ||
d4efbcd9 | 8 | /*----- Licensing notice --------------------------------------------------* |
14d7100d | 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. | |
d4efbcd9 | 16 | * |
14d7100d | 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. | |
d4efbcd9 | 21 | * |
14d7100d | 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 | * | |
28 | * HOWEVER, since GNU adns is covered by the full GNU General Public | |
29 | * License, this file (only) is also covered by the full GNU GPL, and | |
30 | * you may NOT take advantage of the more liberal conditions of the | |
31 | * LGPL when modifying or redistributing this file. This doesn't mean | |
32 | * that a program which uses the interface provided by this file is | |
33 | * covered by the GPL, since @bres.c@ provides the same interface and | |
34 | * is LGPL. However, it does mean that if your program depends, for | |
35 | * some reason (e.g., to meet particular performance criteria), on | |
36 | * this adns-based implementation of mLib's background resolver then it | |
37 | * must be licensed under the full GPL. | |
38 | */ | |
39 | ||
a0150d8d MW |
40 | #include "config.h" |
41 | ||
14d7100d | 42 | #ifndef HAVE_ADNS |
43 | # error "You need the ADNS library to compile this file." | |
44 | #endif | |
45 | ||
46 | /*----- Header files ------------------------------------------------------*/ | |
47 | ||
48 | #include <assert.h> | |
49 | #include <errno.h> | |
50 | #include <signal.h> | |
51 | #include <stdio.h> | |
52 | #include <stdlib.h> | |
53 | #include <string.h> | |
54 | ||
55 | #include <sys/types.h> | |
56 | #include <sys/time.h> | |
57 | #include <unistd.h> | |
58 | #include <sys/wait.h> | |
59 | ||
60 | #include <sys/socket.h> | |
61 | #include <netinet/in.h> | |
62 | #include <arpa/inet.h> | |
63 | #include <netdb.h> | |
64 | ||
65 | #include <adns.h> | |
66 | ||
67 | #include "alloc.h" | |
68 | #include "bres.h" | |
69 | #include "macros.h" | |
70 | #include "report.h" | |
71 | #include "sel.h" | |
72 | ||
73 | /*----- Static variables --------------------------------------------------*/ | |
74 | ||
75 | static adns_state ads; | |
76 | static sel_state *sel; | |
77 | static sel_hook selhook; | |
78 | ||
79 | /*----- Main code ---------------------------------------------------------*/ | |
80 | ||
81 | /* --- @bres_abort@ --- * | |
82 | * | |
83 | * Arguments: @bres_client *rc@ = pointer to client block | |
84 | * | |
85 | * Returns: --- | |
86 | * | |
87 | * Use: Removes a queued job. | |
88 | */ | |
89 | ||
90 | void bres_abort(bres_client *rc) | |
91 | { | |
92 | if (rc->q == adns_r_addr) xfree(rc->u.name); | |
93 | if (rc->a) free(rc->a); | |
94 | adns_cancel(rc->aq); | |
95 | } | |
96 | ||
97 | /* --- @bres_byaddr@ --- * | |
98 | * | |
99 | * Arguments: @bres_client *rc@ = pointer to client block | |
100 | * @struct in_addr addr@ = address to resolve | |
101 | * @void (*func)(struct hostent *h, void *p)@ = handler function | |
102 | * @void *p@ = argument for handler function | |
103 | * | |
104 | * Returns: --- | |
105 | * | |
106 | * Use: Adds an address lookup job to the queue. The job will be | |
107 | * processed when there's a spare resolver process to deal with | |
108 | * it. | |
109 | */ | |
110 | ||
111 | void bres_byaddr(bres_client *rc, struct in_addr addr, | |
112 | void (*func)(struct hostent */*h*/, void */*p*/), | |
113 | void *p) | |
114 | { | |
115 | int e; | |
116 | struct sockaddr_in sin; | |
117 | ||
118 | if (!ads) goto fail; | |
119 | sin.sin_family = AF_INET; | |
120 | sin.sin_addr = addr; | |
121 | sin.sin_port = 0; | |
122 | if ((e = adns_submit_reverse(ads, (struct sockaddr *)&sin, adns_r_ptr, | |
123 | 0, rc, &rc->aq)) != 0) | |
124 | goto fail; | |
125 | rc->a = 0; | |
126 | rc->q = adns_r_ptr; | |
127 | rc->u.addr = addr; | |
128 | rc->func = func; | |
129 | rc->p = p; | |
130 | return; | |
131 | ||
132 | fail: | |
133 | func(0, p); | |
134 | } | |
135 | ||
136 | /* --- @bres_byname@ --- * | |
137 | * | |
138 | * Arguments: @bres_client *rc@ = pointer to client block | |
139 | * @const char *name@ = name to resolve | |
140 | * @void (*func)(struct hostent *h, void *p)@ = handler function | |
141 | * @void *p@ = argument for handler function | |
142 | * | |
143 | * Returns: --- | |
144 | * | |
145 | * Use: Adds a name lookup job to the queue. The job will be | |
146 | * processed when there's a spare resolver process to deal with | |
147 | * it. | |
148 | */ | |
149 | ||
150 | void bres_byname(bres_client *rc, const char *name, | |
151 | void (*func)(struct hostent */*h*/, void */*p*/), | |
152 | void *p) | |
153 | { | |
154 | int e; | |
155 | ||
156 | if (!ads) goto fail; | |
157 | if ((e = adns_submit(ads, name, adns_r_addr, | |
4f6d400b | 158 | adns_qf_search | adns_qf_owner, rc, &rc->aq)) != 0) |
14d7100d | 159 | goto fail; |
160 | rc->a = 0; | |
161 | rc->q = adns_r_addr; | |
162 | rc->u.name = xstrdup(name); | |
163 | rc->func = func; | |
164 | rc->p = p; | |
165 | return; | |
166 | ||
167 | fail: | |
168 | func(0, p); | |
169 | } | |
170 | ||
171 | /* --- @bres_exec@ --- * | |
172 | * | |
173 | * Arguments: @const char *file@ = file containing server code or null | |
174 | * | |
175 | * Returns: --- | |
176 | * | |
177 | * Use: Makes `bres' use a standalone server rather than copies of | |
178 | * the current process. This can reduce memory consumption for | |
179 | * large processes, at the expense of startup time (which | |
180 | * shouldn't be too bad anyway, because of the resolver design). | |
181 | * If the filename is null, a default set up at install time is | |
182 | * used. It's probably a good idea to leave it alone. | |
183 | */ | |
184 | ||
185 | void bres_exec(const char *file) | |
186 | { | |
187 | /* Nothin' doin' */ | |
188 | } | |
189 | ||
190 | /* --- @report@ --- * | |
191 | * | |
192 | * Arguments: @bres_client *c@ = client descriptor block | |
193 | * @adns_answer *a@ = A-record answer from resolver library | |
194 | * @adns_rr_addr *av@ = vector of address records | |
195 | * @int an@ = number of address records (must be positive) | |
196 | * @char **nv@ = vector of name strings | |
197 | * @int nn@ = number of name strings (must be positive) | |
198 | * | |
199 | * Returns: --- | |
200 | * | |
201 | * Use: Formats the given answer into a @struct hostent@ and reports | |
202 | * it to the waiting client application. | |
203 | */ | |
204 | ||
205 | static void report(bres_client *rc, adns_answer *a, | |
206 | adns_rr_addr *av, int an, | |
207 | char **nv, int nn) | |
208 | { | |
209 | struct hostent h; | |
210 | char *n[16]; | |
211 | char *aa[16]; | |
212 | int i, j; | |
213 | ||
214 | j = 0; | |
215 | if (a->cname) n[j++] = a->cname; | |
216 | else { n[j++] = *nv; nv++; nn--; } | |
217 | for (i = 0; i < nn && j < N(n) - 1; i++) | |
36188114 | 218 | if (STRCMP(n[0], !=, nv[i])) n[j++] = nv[i]; |
14d7100d | 219 | n[j++] = 0; |
5086ffd7 | 220 | for (i = j = 0; i < an && j < N(aa) - 1; i++) { |
14d7100d | 221 | if (av[i].addr.sa.sa_family == AF_INET) |
222 | aa[j++] = (char *)&av[i].addr.inet.sin_addr; | |
223 | } | |
224 | aa[j++] = 0; | |
225 | h.h_name = n[0]; | |
226 | h.h_aliases = n + 1; | |
227 | h.h_addrtype = AF_INET; | |
228 | h.h_length = sizeof(struct in_addr); | |
229 | h.h_addr_list = aa; | |
d4efbcd9 | 230 | rc->func(&h, rc->p); |
14d7100d | 231 | } |
232 | ||
233 | /* --- @beforehook@, @afterhook@ --- * | |
234 | * | |
235 | * Arguments: @sel_state *s@ = select state | |
236 | * @sel_args *sa@ = argument block | |
237 | * @void *p@ = uninteresting pointer | |
238 | * | |
239 | * Returns: --- | |
240 | * | |
241 | * Use: Processes the selector's arguments before @select@ is | |
242 | * called, to allow ADNS to do its thing. | |
243 | */ | |
244 | ||
245 | static void beforehook(sel_state *s, sel_args *sa, void *p) | |
246 | { | |
247 | adns_beforeselect(ads, &sa->maxfd, | |
248 | &sa->fd[SEL_READ], &sa->fd[SEL_WRITE], &sa->fd[SEL_EXC], | |
249 | &sa->tvp, &sa->tv, &sa->now); | |
250 | } | |
251 | ||
252 | static void afterhook(sel_state *s, sel_args *sa, void *p) | |
253 | { | |
254 | void *c; | |
255 | bres_client *rc; | |
256 | adns_query q; | |
24a657cc | 257 | adns_answer *a, *aa; |
14d7100d | 258 | int e; |
259 | int i; | |
260 | ||
261 | adns_afterselect(ads, sa->maxfd, | |
262 | &sa->fd[SEL_READ], &sa->fd[SEL_WRITE], &sa->fd[SEL_EXC], | |
263 | &sa->now); | |
264 | while (q = 0, (e = adns_check(ads, &q, &a, &c)) == 0) { | |
265 | rc = c; | |
266 | if (a->status != 0) | |
267 | goto fail; | |
268 | else switch (rc->q) { | |
269 | case adns_r_addr: | |
270 | assert(a->type == adns_r_addr); | |
1dc93196 | 271 | xfree(rc->u.name); |
24a657cc | 272 | report(rc, a, a->rrs.addr, a->nrrs, &a->owner, 1); |
14d7100d | 273 | free(a); |
274 | break; | |
275 | case adns_r_ptr: | |
276 | if (a->type == adns_r_ptr) { | |
277 | rc->a = a; | |
278 | if ((e = adns_submit(ads, a->rrs.str[0], adns_r_addr, | |
279 | 0, rc, &q)) != 0) | |
280 | goto fail; | |
281 | rc->aq = q; | |
282 | } else { | |
283 | assert(a->type == adns_r_addr); | |
284 | for (i = 0; i < a->nrrs; i++) { | |
285 | if (a->rrs.addr[i].addr.sa.sa_family == AF_INET && | |
286 | a->rrs.addr[i].addr.inet.sin_addr.s_addr == | |
287 | rc->u.addr.s_addr) | |
288 | goto match; | |
289 | } | |
290 | goto fail; | |
291 | match: | |
24a657cc | 292 | aa = rc->a; |
293 | report(rc, a, &a->rrs.addr[i], 1, aa->rrs.str, aa->nrrs); | |
294 | free(aa); | |
14d7100d | 295 | free(a); |
296 | } | |
297 | break; | |
298 | default: | |
299 | abort(); | |
300 | } | |
301 | continue; | |
302 | ||
303 | fail: | |
14d7100d | 304 | if (rc->q == adns_r_addr) xfree(rc->u.name); |
305 | if (rc->a) free(rc->a); | |
24a657cc | 306 | rc->func(0, rc->p); |
14d7100d | 307 | free(a); |
308 | } | |
309 | } | |
310 | ||
311 | /* --- @bres_init@ --- * | |
312 | * | |
313 | * Arguments: @sel_state *s@ = pointer to select multiplexor | |
314 | * | |
315 | * Returns: --- | |
316 | * | |
317 | * Use: Initializes the background resolver for use. | |
318 | */ | |
319 | ||
320 | void bres_init(sel_state *s) | |
321 | { | |
322 | int e; | |
323 | ||
d46d1a2f | 324 | if ((e = adns_init(&ads, adns_if_noautosys, 0)) != 0) { |
14d7100d | 325 | moan("adns_init failed: resolver won't work"); |
326 | return; | |
327 | } | |
328 | sel_addhook(s, &selhook, beforehook, afterhook, 0); | |
329 | sel = s; | |
330 | } | |
331 | ||
332 | /*----- That's all, folks -------------------------------------------------*/ |