3 * $Id: bres-adns.c,v 1.2 2003/12/14 14:46:38 mdw Exp $
5 * Background reverse name resolution (ADNS version)
7 * (c) 2003 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of the mLib utilities library.
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.
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.
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,
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.
42 /*----- Revision history --------------------------------------------------*
44 * $Log: bres-adns.c,v $
45 * Revision 1.2 2003/12/14 14:46:38 mdw
46 * Qualify name given to @bres_byname@.
48 * Revision 1.1 2003/12/13 20:37:59 mdw
49 * Add adns support in background resolver.
54 # error "You need the ADNS library to compile this file."
57 /*----- Header files ------------------------------------------------------*/
66 #include <sys/types.h>
71 #include <sys/socket.h>
72 #include <netinet/in.h>
73 #include <arpa/inet.h>
84 /*----- Static variables --------------------------------------------------*/
86 static adns_state ads;
87 static sel_state *sel;
88 static sel_hook selhook;
90 /*----- Main code ---------------------------------------------------------*/
92 /* --- @bres_abort@ --- *
94 * Arguments: @bres_client *rc@ = pointer to client block
98 * Use: Removes a queued job.
101 void bres_abort(bres_client *rc)
103 if (rc->q == adns_r_addr) xfree(rc->u.name);
104 if (rc->a) free(rc->a);
108 /* --- @bres_byaddr@ --- *
110 * Arguments: @bres_client *rc@ = pointer to client block
111 * @struct in_addr addr@ = address to resolve
112 * @void (*func)(struct hostent *h, void *p)@ = handler function
113 * @void *p@ = argument for handler function
117 * Use: Adds an address lookup job to the queue. The job will be
118 * processed when there's a spare resolver process to deal with
122 void bres_byaddr(bres_client *rc, struct in_addr addr,
123 void (*func)(struct hostent */*h*/, void */*p*/),
127 struct sockaddr_in sin;
130 sin.sin_family = AF_INET;
133 if ((e = adns_submit_reverse(ads, (struct sockaddr *)&sin, adns_r_ptr,
134 0, rc, &rc->aq)) != 0)
147 /* --- @bres_byname@ --- *
149 * Arguments: @bres_client *rc@ = pointer to client block
150 * @const char *name@ = name to resolve
151 * @void (*func)(struct hostent *h, void *p)@ = handler function
152 * @void *p@ = argument for handler function
156 * Use: Adds a name lookup job to the queue. The job will be
157 * processed when there's a spare resolver process to deal with
161 void bres_byname(bres_client *rc, const char *name,
162 void (*func)(struct hostent */*h*/, void */*p*/),
168 if ((e = adns_submit(ads, name, adns_r_addr,
169 adns_qf_search | adns_qf_owner, rc, &rc->aq)) != 0)
173 rc->u.name = xstrdup(name);
182 /* --- @bres_exec@ --- *
184 * Arguments: @const char *file@ = file containing server code or null
188 * Use: Makes `bres' use a standalone server rather than copies of
189 * the current process. This can reduce memory consumption for
190 * large processes, at the expense of startup time (which
191 * shouldn't be too bad anyway, because of the resolver design).
192 * If the filename is null, a default set up at install time is
193 * used. It's probably a good idea to leave it alone.
196 void bres_exec(const char *file)
201 /* --- @report@ --- *
203 * Arguments: @bres_client *c@ = client descriptor block
204 * @adns_answer *a@ = A-record answer from resolver library
205 * @adns_rr_addr *av@ = vector of address records
206 * @int an@ = number of address records (must be positive)
207 * @char **nv@ = vector of name strings
208 * @int nn@ = number of name strings (must be positive)
212 * Use: Formats the given answer into a @struct hostent@ and reports
213 * it to the waiting client application.
216 static void report(bres_client *rc, adns_answer *a,
217 adns_rr_addr *av, int an,
226 if (a->cname) n[j++] = a->cname;
227 else { n[j++] = *nv; nv++; nn--; }
228 for (i = 0; i < nn && j < N(n) - 1; i++)
229 if (strcmp(n[0], nv[i]) != 0) n[j++] = nv[i];
231 for (i = j = 0; i < an && j < N(av) - 1; i++) {
232 if (av[i].addr.sa.sa_family == AF_INET)
233 aa[j++] = (char *)&av[i].addr.inet.sin_addr;
238 h.h_addrtype = AF_INET;
239 h.h_length = sizeof(struct in_addr);
244 /* --- @beforehook@, @afterhook@ --- *
246 * Arguments: @sel_state *s@ = select state
247 * @sel_args *sa@ = argument block
248 * @void *p@ = uninteresting pointer
252 * Use: Processes the selector's arguments before @select@ is
253 * called, to allow ADNS to do its thing.
256 static void beforehook(sel_state *s, sel_args *sa, void *p)
258 adns_beforeselect(ads, &sa->maxfd,
259 &sa->fd[SEL_READ], &sa->fd[SEL_WRITE], &sa->fd[SEL_EXC],
260 &sa->tvp, &sa->tv, &sa->now);
263 static void afterhook(sel_state *s, sel_args *sa, void *p)
272 adns_afterselect(ads, sa->maxfd,
273 &sa->fd[SEL_READ], &sa->fd[SEL_WRITE], &sa->fd[SEL_EXC],
275 while (q = 0, (e = adns_check(ads, &q, &a, &c)) == 0) {
279 else switch (rc->q) {
281 assert(a->type == adns_r_addr);
282 report(rc, a, a->rrs.addr, a->nrrs, &a->owner, 1);
287 if (a->type == adns_r_ptr) {
289 if ((e = adns_submit(ads, a->rrs.str[0], adns_r_addr,
294 assert(a->type == adns_r_addr);
295 for (i = 0; i < a->nrrs; i++) {
296 if (a->rrs.addr[i].addr.sa.sa_family == AF_INET &&
297 a->rrs.addr[i].addr.inet.sin_addr.s_addr ==
303 report(rc, a, &a->rrs.addr[i], 1, rc->a->rrs.str, rc->a->nrrs);
315 if (rc->q == adns_r_addr) xfree(rc->u.name);
316 if (rc->a) free(rc->a);
321 /* --- @bres_init@ --- *
323 * Arguments: @sel_state *s@ = pointer to select multiplexor
327 * Use: Initializes the background resolver for use.
330 void bres_init(sel_state *s)
334 if ((e = adns_init(&ads, 0, 0)) != 0) {
335 moan("adns_init failed: resolver won't work");
338 sel_addhook(s, &selhook, beforehook, afterhook, 0);
342 /*----- That's all, folks -------------------------------------------------*/