3 * - overall query management (allocation, completion)
4 * - per-query memory management
5 * - query submission and cancellation (user-visible and internal)
8 * This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2, or (at your option)
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software Foundation,
22 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
35 static adns_query query_alloc(adns_state ads, const typeinfo *typei,
36 adns_queryflags flags, struct timeval now) {
37 /* Allocate a virgin query and return it. */
40 qu= malloc(sizeof(*qu)); if (!qu) return 0;
41 qu->answer= malloc(sizeof(*qu->answer)); if (!qu->answer) { free(qu); return 0; }
44 qu->state= query_tosend;
45 qu->back= qu->next= qu->parent= 0;
46 LIST_INIT(qu->children);
47 LINK_INIT(qu->siblings);
48 LIST_INIT(qu->allocations);
49 qu->interim_allocd= 0;
50 qu->preserved_allocd= 0;
51 qu->final_allocspace= 0;
56 adns__vbuf_init(&qu->vb);
59 qu->cname_dglen= qu->cname_begin= 0;
61 adns__vbuf_init(&qu->search_vb);
62 qu->search_origlen= qu->search_pos= qu->search_doneabs= 0;
68 qu->udpsent= qu->tcpfailed= 0;
69 timerclear(&qu->timeout);
70 qu->expires= now.tv_sec + MAXTTLBELIEVE;
72 memset(&qu->ctx,0,sizeof(qu->ctx));
74 qu->answer->status= adns_s_ok;
75 qu->answer->cname= qu->answer->owner= 0;
76 qu->answer->type= typei->type;
77 qu->answer->expires= -1;
79 qu->answer->rrs.untyped= 0;
80 qu->answer->rrsz= typei->rrsz;
85 static void query_submit(adns_state ads, adns_query qu,
86 const typeinfo *typei, vbuf *qumsg_vb, int id,
87 adns_queryflags flags, struct timeval now) {
88 /* Fills in the query message in for a previously-allocated query,
89 * and submits it. Cannot fail.
93 adns__vbuf_init(qumsg_vb);
95 qu->query_dgram= malloc(qu->vb.used);
96 if (!qu->query_dgram) { adns__query_fail(qu,adns_s_nomemory); return; }
99 qu->query_dglen= qu->vb.used;
100 memcpy(qu->query_dgram,qu->vb.buf,qu->vb.used);
102 adns__query_send(qu,now);
103 adns__autosys(ads,now);
106 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
107 const typeinfo *typei, vbuf *qumsg_vb, int id,
108 adns_queryflags flags, struct timeval now,
109 const qcontext *ctx) {
112 qu= query_alloc(ads,typei,flags,now);
113 if (!qu) { adns__vbuf_free(qumsg_vb); return adns_s_nomemory; }
116 memcpy(&qu->ctx,ctx,sizeof(qu->ctx));
117 query_submit(ads,qu, typei,qumsg_vb,id,flags,now);
122 static void query_simple(adns_state ads, adns_query qu,
123 const char *owner, int ol,
124 const typeinfo *typei, adns_queryflags flags,
125 struct timeval now) {
130 adns__vbuf_init(&vb);
132 stat= adns__mkquery(ads,&vb,&id, owner,ol, typei,flags);
133 if (stat) { adns__query_fail(qu,stat); return; }
135 query_submit(ads,qu, typei,&vb,id, flags,now);
138 void adns__search_next(adns_state ads, adns_query qu, struct timeval now) {
139 const char *nextentry;
142 if (qu->search_doneabs<0) {
144 qu->search_doneabs= 1;
146 if (qu->search_pos >= ads->nsearchlist) {
147 if (qu->search_doneabs) {
148 stat= adns_s_nxdomain; goto x_fail;
152 qu->search_doneabs= 1;
155 nextentry= ads->searchlist[qu->search_pos++];
159 qu->search_vb.used= qu->search_origlen;
161 if (!adns__vbuf_append(&qu->search_vb,".",1) ||
162 !adns__vbuf_appendstr(&qu->search_vb,nextentry)) {
163 stat= adns_s_nomemory; goto x_fail;
167 free(qu->query_dgram);
168 qu->query_dgram= 0; qu->query_dglen= 0;
170 query_simple(ads,qu, qu->search_vb.buf, qu->search_vb.used, qu->typei, qu->flags, now);
174 adns__query_fail(qu,stat);
177 static int save_owner(adns_query qu, const char *owner, int ol) {
178 /* Returns 1 if OK, otherwise there was no memory. */
184 ans->owner= adns__alloc_preserved(qu,ol+1); if (!ans->owner) return 0;
186 memcpy(ans->owner,owner,ol);
191 int adns_submit(adns_state ads,
194 adns_queryflags flags,
196 adns_query *query_r) {
199 const typeinfo *typei;
204 adns__consistency(ads,cc_entex);
206 typei= adns__findtype(type);
207 if (!typei) return ENOSYS;
209 r= gettimeofday(&now,0); if (r) goto x_errno;
210 qu= query_alloc(ads,typei,flags,now); if (!qu) goto x_errno;
212 qu->ctx.ext= context;
214 memset(&qu->ctx.info,0,sizeof(qu->ctx.info));
219 if (!ol) { stat= adns_s_querydomaininvalid; goto x_adnsfail; }
220 if (ol>DNS_MAXDOMAIN+1) { stat= adns_s_querydomaintoolong; goto x_adnsfail; }
222 if (ol>=1 && owner[ol-1]=='.' && (ol<2 || owner[ol-2]!='\\')) {
223 flags &= ~adns_qf_search;
227 if (flags & adns_qf_search) {
228 r= adns__vbuf_append(&qu->search_vb,owner,ol);
229 if (!r) { stat= adns_s_nomemory; goto x_adnsfail; }
231 for (ndots=0, p=owner; (p= strchr(p,'.')); p++, ndots++);
232 qu->search_doneabs= (ndots >= ads->searchndots) ? -1 : 0;
233 qu->search_origlen= ol;
234 adns__search_next(ads,qu,now);
236 if (flags & adns_qf_owner) {
237 if (!save_owner(qu,owner,ol)) { stat= adns_s_nomemory; goto x_adnsfail; }
239 query_simple(ads,qu, owner,ol, typei,flags, now);
241 adns__consistency(ads,cc_entex);
245 adns__query_fail(qu,stat);
246 adns__consistency(ads,cc_entex);
252 adns__consistency(ads,cc_entex);
256 int adns_synchronous(adns_state ads,
259 adns_queryflags flags,
260 adns_answer **answer_r) {
264 r= adns_submit(ads,owner,type,flags,0,&qu);
267 r= adns_wait(ads,&qu,answer_r,0);
268 if (r) adns_cancel(qu);
273 static void *alloc_common(adns_query qu, size_t sz) {
276 if (!sz) return qu; /* Any old pointer will do */
277 assert(!qu->final_allocspace);
278 an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz));
280 LIST_LINK_TAIL(qu->allocations,an);
281 return (byte*)an + MEM_ROUND(sizeof(*an));
284 void *adns__alloc_interim(adns_query qu, size_t sz) {
288 rv= alloc_common(qu,sz);
290 qu->interim_allocd += sz;
294 void *adns__alloc_preserved(adns_query qu, size_t sz) {
298 rv= adns__alloc_interim(qu,sz);
300 qu->preserved_allocd += sz;
304 void *adns__alloc_mine(adns_query qu, size_t sz) {
305 return alloc_common(qu,MEM_ROUND(sz));
308 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz) {
312 an= (void*)((byte*)block - MEM_ROUND(sizeof(*an)));
314 assert(!to->final_allocspace);
315 assert(!from->final_allocspace);
317 LIST_UNLINK(from->allocations,an);
318 LIST_LINK_TAIL(to->allocations,an);
320 from->interim_allocd -= sz;
321 to->interim_allocd += sz;
323 if (to->expires > from->expires) to->expires= from->expires;
326 void *adns__alloc_final(adns_query qu, size_t sz) {
327 /* When we're in the _final stage, we _subtract_ from interim_alloc'd
328 * each allocation, and use final_allocspace to point to the next free
334 rp= qu->final_allocspace;
336 qu->interim_allocd -= sz;
337 assert(qu->interim_allocd>=0);
338 qu->final_allocspace= (byte*)rp + sz;
342 static void cancel_children(adns_query qu) {
343 adns_query cqu, ncqu;
345 for (cqu= qu->children.head; cqu; cqu= ncqu) {
346 ncqu= cqu->siblings.next;
349 LIST_INIT(qu->children);
352 void adns__reset_preserved(adns_query qu) {
353 assert(!qu->final_allocspace);
356 qu->answer->rrs.untyped= 0;
357 qu->interim_allocd= qu->preserved_allocd;
360 static void free_query_allocs(adns_query qu) {
364 for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); }
365 adns__vbuf_free(&qu->vb);
368 void adns_cancel(adns_query qu) {
372 adns__consistency(ads,cc_entex);
374 case query_tosend: case query_tcpwait: case query_tcpsent:
375 LIST_UNLINK(ads->timew,qu);
378 LIST_UNLINK(ads->childw,qu);
381 LIST_UNLINK(ads->output,qu);
386 free_query_allocs(qu);
389 adns__consistency(ads,cc_entex);
392 void adns__update_expires(adns_query qu, unsigned long ttl, struct timeval now) {
395 assert(ttl <= MAXTTLBELIEVE);
396 max= now.tv_sec + ttl;
397 if (qu->expires < max) return;
401 static void makefinal_query(adns_query qu) {
407 if (qu->interim_allocd) {
408 ans= realloc(qu->answer, MEM_ROUND(MEM_ROUND(sizeof(*ans)) + qu->interim_allocd));
409 if (!ans) goto x_nomem;
413 qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans));
414 adns__makefinal_str(qu,&ans->cname);
415 adns__makefinal_str(qu,&ans->owner);
418 adns__makefinal_block(qu, &ans->rrs.untyped, ans->nrrs*ans->rrsz);
420 for (rrn=0; rrn<ans->nrrs; rrn++)
421 qu->typei->makefinal(qu, ans->rrs.bytes + rrn*ans->rrsz);
424 free_query_allocs(qu);
428 qu->preserved_allocd= 0;
429 qu->answer->cname= 0;
430 qu->answer->owner= 0;
431 adns__reset_preserved(qu); /* (but we just threw away the preserved stuff) */
433 qu->answer->status= adns_s_nomemory;
434 free_query_allocs(qu);
437 void adns__query_done(adns_query qu) {
446 if (qu->flags & adns_qf_owner && qu->flags & adns_qf_search &&
447 ans->status != adns_s_nomemory) {
448 if (!save_owner(qu, qu->search_vb.buf, qu->search_vb.used)) {
449 adns__query_fail(qu,adns_s_nomemory);
454 if (ans->nrrs && qu->typei->diff_needswap) {
455 if (!adns__vbuf_ensure(&qu->vb,qu->typei->rrsz)) {
456 adns__query_fail(qu,adns_s_nomemory);
459 adns__isort(ans->rrs.bytes, ans->nrrs, ans->rrsz,
461 (int(*)(void*, const void*, const void*))qu->typei->diff_needswap,
465 ans->expires= qu->expires;
468 LIST_UNLINK_PART(parent->children,qu,siblings.);
469 LIST_UNLINK(qu->ads->childw,parent);
470 qu->ctx.callback(parent,qu);
471 free_query_allocs(qu);
475 LIST_LINK_TAIL(qu->ads->output,qu);
477 qu->state= query_done;
480 void adns__query_fail(adns_query qu, adns_status stat) {
481 adns__reset_preserved(qu);
482 qu->answer->status= stat;
483 adns__query_done(qu);
486 void adns__makefinal_str(adns_query qu, char **strp) {
488 char *before, *after;
493 after= adns__alloc_final(qu,l);
494 memcpy(after,before,l);
498 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) {
499 void *before, *after;
503 after= adns__alloc_final(qu,sz);
504 memcpy(after,before,sz);