ossp-pkg/adns/adns_query.c
1.7
/*
* query.c
* - overall query management (allocation, completion)
* - per-query memory management
* - query submission and cancellation (user-visible and internal)
*/
/*
* This file is
* Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
*
* It is part of adns, which is
* Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
* Copyright (C) 1999-2000 Tony Finch <dot@dotat.at>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include "adns_internal.h"
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/time.h>
#include "adns_internal.h"
static adns_query query_alloc(adns_state ads, const typeinfo *typei,
adns_queryflags flags, struct timeval now) {
/* Allocate a virgin query and return it. */
adns_query qu;
qu= malloc(sizeof(*qu)); if (!qu) return 0;
qu->answer= malloc(sizeof(*qu->answer)); if (!qu->answer) { free(qu); return 0; }
qu->ads= ads;
qu->state= query_tosend;
qu->back= qu->next= qu->parent= 0;
ADNS_LIST_INIT(qu->children);
ADNS_LINK_INIT(qu->siblings);
ADNS_LIST_INIT(qu->allocations);
qu->interim_allocd= 0;
qu->preserved_allocd= 0;
qu->final_allocspace= 0;
qu->typei= typei;
qu->query_dgram= 0;
qu->query_dglen= 0;
adns__vbuf_init(&qu->vb);
qu->cname_dgram= 0;
qu->cname_dglen= qu->cname_begin= 0;
adns__vbuf_init(&qu->search_vb);
qu->search_origlen= qu->search_pos= qu->search_doneabs= 0;
qu->id= -2; /* will be overwritten with real id before we leave adns */
qu->flags= flags;
qu->retries= 0;
qu->udpnextserver= 0;
qu->udpsent= 0;
timerclear(&qu->timeout);
qu->expires= now.tv_sec + MAXTTLBELIEVE;
memset(&qu->ctx,0,sizeof(qu->ctx));
qu->answer->status= adns_s_ok;
qu->answer->cname= qu->answer->owner= 0;
qu->answer->type= typei->type;
qu->answer->expires= -1;
qu->answer->nrrs= 0;
qu->answer->rrs.untyped= 0;
qu->answer->rrsz= typei->rrsz;
return qu;
}
static void query_submit(adns_state ads, adns_query qu,
const typeinfo *typei, vbuf *qumsg_vb, int id,
adns_queryflags flags, struct timeval now) {
/* Fills in the query message in for a previously-allocated query,
* and submits it. Cannot fail. Takes over the memory for qumsg_vb.
*/
qu->vb= *qumsg_vb;
adns__vbuf_init(qumsg_vb);
qu->query_dgram= malloc(qu->vb.used);
if (!qu->query_dgram) { adns__query_fail(qu,adns_s_nomemory); return; }
qu->id= id;
qu->query_dglen= qu->vb.used;
memcpy(qu->query_dgram,qu->vb.buf,qu->vb.used);
adns__query_send(qu,now);
}
adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
const typeinfo *typei, vbuf *qumsg_vb, int id,
adns_queryflags flags, struct timeval now,
const qcontext *ctx) {
adns_query qu;
qu= query_alloc(ads,typei,flags,now);
if (!qu) { adns__vbuf_free(qumsg_vb); return adns_s_nomemory; }
*query_r= qu;
memcpy(&qu->ctx,ctx,sizeof(qu->ctx));
query_submit(ads,qu, typei,qumsg_vb,id,flags,now);
return adns_s_ok;
}
static void query_simple(adns_state ads, adns_query qu,
const char *owner, int ol,
const typeinfo *typei, adns_queryflags flags,
struct timeval now) {
vbuf vb_new;
int id;
adns_status stat;
stat= adns__mkquery(ads,&qu->vb,&id, owner,ol, typei,flags);
if (stat) {
if (stat == adns_s_querydomaintoolong && (flags & adns_qf_search)) {
adns__search_next(ads,qu,now);
return;
} else {
adns__query_fail(qu,stat);
return;
}
}
vb_new= qu->vb;
adns__vbuf_init(&qu->vb);
query_submit(ads,qu, typei,&vb_new,id, flags,now);
}
void adns__search_next(adns_state ads, adns_query qu, struct timeval now) {
const char *nextentry;
adns_status stat;
if (qu->search_doneabs<0) {
nextentry= 0;
qu->search_doneabs= 1;
} else {
if (qu->search_pos >= ads->nsearchlist) {
if (qu->search_doneabs) {
stat= adns_s_nxdomain; goto x_fail;
return;
} else {
nextentry= 0;
qu->search_doneabs= 1;
}
} else {
nextentry= ads->searchlist[qu->search_pos++];
}
}
qu->search_vb.used= qu->search_origlen;
if (nextentry) {
if (!adns__vbuf_append(&qu->search_vb,(const byte *)".",1) ||
!adns__vbuf_appendstr(&qu->search_vb,nextentry)) {
stat= adns_s_nomemory; goto x_fail;
}
}
free(qu->query_dgram);
qu->query_dgram= 0; qu->query_dglen= 0;
query_simple(ads,qu, (const char *)qu->search_vb.buf, qu->search_vb.used, qu->typei, qu->flags, now);
return;
x_fail:
adns__query_fail(qu,stat);
}
static int save_owner(adns_query qu, const char *owner, int ol) {
/* Returns 1 if OK, otherwise there was no memory. */
adns_answer *ans;
ans= qu->answer;
assert(!ans->owner);
ans->owner= adns__alloc_preserved(qu,ol+1); if (!ans->owner) return 0;
memcpy(ans->owner,owner,ol);
ans->owner[ol]= 0;
return 1;
}
int adns_submit(adns_state ads,
const char *owner,
adns_rrtype type,
adns_queryflags flags,
void *context,
adns_query *query_r) {
int r, ol, ndots;
adns_status stat;
const typeinfo *typei;
struct timeval now;
adns_query qu;
const char *p;
adns__consistency(ads,0,cc_entex);
typei= adns__findtype(type);
if (!typei) return ENOSYS;
r= gettimeofday(&now,0); if (r) goto x_errno;
qu= query_alloc(ads,typei,flags,now); if (!qu) goto x_errno;
qu->ctx.ext= context;
qu->ctx.callback= 0;
memset(&qu->ctx.info,0,sizeof(qu->ctx.info));
*query_r= qu;
ol= strlen(owner);
if (!ol) { stat= adns_s_querydomaininvalid; goto x_adnsfail; }
if (ol>DNS_MAXDOMAIN+1) { stat= adns_s_querydomaintoolong; goto x_adnsfail; }
if (ol>=1 && owner[ol-1]=='.' && (ol<2 || owner[ol-2]!='\\')) {
flags &= ~adns_qf_search;
qu->flags= flags;
ol--;
}
if (flags & adns_qf_search) {
r= adns__vbuf_append(&qu->search_vb,(const byte *)owner,ol);
if (!r) { stat= adns_s_nomemory; goto x_adnsfail; }
for (ndots=0, p=owner; (p= strchr(p,'.')); p++, ndots++);
qu->search_doneabs= (ndots >= ads->searchndots) ? -1 : 0;
qu->search_origlen= ol;
adns__search_next(ads,qu,now);
} else {
if (flags & adns_qf_owner) {
if (!save_owner(qu,owner,ol)) { stat= adns_s_nomemory; goto x_adnsfail; }
}
query_simple(ads,qu, owner,ol, typei,flags, now);
}
adns__autosys(ads,now);
adns__consistency(ads,qu,cc_entex);
return 0;
x_adnsfail:
adns__query_fail(qu,stat);
adns__consistency(ads,qu,cc_entex);
return 0;
x_errno:
r= errno;
assert(r);
adns__consistency(ads,0,cc_entex);
return r;
}
int adns_submit_reverse_any(adns_state ads,
const struct sockaddr *addr,
const char *zone,
adns_rrtype type,
adns_queryflags flags,
void *context,
adns_query *query_r) {
const unsigned char *iaddr;
char *buf, *buf_free;
char shortbuf[100];
int r, lreq;
flags &= ~adns_qf_search;
if (addr->sa_family != AF_INET) return ENOSYS;
iaddr= (const unsigned char*) &(((const struct sockaddr_in*)addr) -> sin_addr);
lreq= strlen(zone) + 4*4 + 1;
if (lreq > sizeof(shortbuf)) {
buf= malloc(strlen(zone) + 4*4 + 1);
if (!buf) return errno;
buf_free= buf;
} else {
buf= shortbuf;
buf_free= 0;
}
sprintf(buf, "%d.%d.%d.%d.%s", iaddr[3], iaddr[2], iaddr[1], iaddr[0], zone);
r= adns_submit(ads,buf,type,flags,context,query_r);
free(buf_free);
return r;
}
int adns_submit_reverse(adns_state ads,
const struct sockaddr *addr,
adns_rrtype type,
adns_queryflags flags,
void *context,
adns_query *query_r) {
if (type != adns_r_ptr && type != adns_r_ptr_raw) return EINVAL;
return adns_submit_reverse_any(ads,addr,"in-addr.arpa",type,flags,context,query_r);
}
int adns_synchronous(adns_state ads,
const char *owner,
adns_rrtype type,
adns_queryflags flags,
adns_answer **answer_r) {
adns_query qu;
int r;
r= adns_submit(ads,owner,type,flags,0,&qu);
if (r) return r;
r= adns_wait(ads,&qu,answer_r,0);
if (r) adns_cancel(qu);
return r;
}
static void *alloc_common(adns_query qu, size_t sz) {
allocnode *an;
if (!sz) return qu; /* Any old pointer will do */
assert(!qu->final_allocspace);
an= malloc(MEM_ROUND(MEM_ROUND(sizeof(*an)) + sz));
if (!an) return 0;
ADNS_LIST_LINK_TAIL(qu->allocations,an);
return (byte*)an + MEM_ROUND(sizeof(*an));
}
void *adns__alloc_interim(adns_query qu, size_t sz) {
void *rv;
sz= MEM_ROUND(sz);
rv= alloc_common(qu,sz);
if (!rv) return 0;
qu->interim_allocd += sz;
return rv;
}
void *adns__alloc_preserved(adns_query qu, size_t sz) {
void *rv;
sz= MEM_ROUND(sz);
rv= adns__alloc_interim(qu,sz);
if (!rv) return 0;
qu->preserved_allocd += sz;
return rv;
}
void *adns__alloc_mine(adns_query qu, size_t sz) {
return alloc_common(qu,MEM_ROUND(sz));
}
void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz) {
allocnode *an;
if (!block) return;
an= (void*)((byte*)block - MEM_ROUND(sizeof(*an)));
assert(!to->final_allocspace);
assert(!from->final_allocspace);
ADNS_LIST_UNLINK(from->allocations,an);
ADNS_LIST_LINK_TAIL(to->allocations,an);
sz= MEM_ROUND(sz);
from->interim_allocd -= sz;
to->interim_allocd += sz;
if (to->expires > from->expires) to->expires= from->expires;
}
void *adns__alloc_final(adns_query qu, size_t sz) {
/* When we're in the _final stage, we _subtract_ from interim_alloc'd
* each allocation, and use final_allocspace to point to the next free
* bit.
*/
void *rp;
sz= MEM_ROUND(sz);
rp= qu->final_allocspace;
assert(rp);
qu->interim_allocd -= sz;
assert(qu->interim_allocd>=0);
qu->final_allocspace= (byte*)rp + sz;
return rp;
}
static void cancel_children(adns_query qu) {
adns_query cqu, ncqu;
for (cqu= qu->children.head; cqu; cqu= ncqu) {
ncqu= cqu->siblings.next;
adns_cancel(cqu);
}
}
void adns__reset_preserved(adns_query qu) {
assert(!qu->final_allocspace);
cancel_children(qu);
qu->answer->nrrs= 0;
qu->answer->rrs.untyped= 0;
qu->interim_allocd= qu->preserved_allocd;
}
static void free_query_allocs(adns_query qu) {
allocnode *an, *ann;
cancel_children(qu);
for (an= qu->allocations.head; an; an= ann) { ann= an->next; free(an); }
ADNS_LIST_INIT(qu->allocations);
adns__vbuf_free(&qu->vb);
adns__vbuf_free(&qu->search_vb);
free(qu->query_dgram);
qu->query_dgram= 0;
}
void adns_cancel(adns_query qu) {
adns_state ads;
ads= qu->ads;
adns__consistency(ads,qu,cc_entex);
if (qu->parent) ADNS_LIST_UNLINK_PART(qu->parent->children,qu,siblings.);
switch (qu->state) {
case query_tosend:
ADNS_LIST_UNLINK(ads->udpw,qu);
break;
case query_tcpw:
ADNS_LIST_UNLINK(ads->tcpw,qu);
break;
case query_childw:
ADNS_LIST_UNLINK(ads->childw,qu);
break;
case query_done:
ADNS_LIST_UNLINK(ads->output,qu);
break;
default:
abort();
}
free_query_allocs(qu);
free(qu->answer);
free(qu);
adns__consistency(ads,0,cc_entex);
}
void adns__update_expires(adns_query qu, unsigned long ttl, struct timeval now) {
time_t max;
assert(ttl <= MAXTTLBELIEVE);
max= now.tv_sec + ttl;
if (qu->expires < max) return;
qu->expires= max;
}
static void makefinal_query(adns_query qu) {
adns_answer *ans;
int rrn;
ans= qu->answer;
if (qu->interim_allocd) {
ans= realloc(qu->answer, MEM_ROUND(MEM_ROUND(sizeof(*ans)) + qu->interim_allocd));
if (!ans) goto x_nomem;
qu->answer= ans;
}
qu->final_allocspace= (byte*)ans + MEM_ROUND(sizeof(*ans));
adns__makefinal_str(qu,&ans->cname);
adns__makefinal_str(qu,&ans->owner);
if (ans->nrrs) {
adns__makefinal_block(qu, &ans->rrs.untyped, ans->nrrs*ans->rrsz);
for (rrn=0; rrn<ans->nrrs; rrn++)
qu->typei->makefinal(qu, ans->rrs.bytes + rrn*ans->rrsz);
}
free_query_allocs(qu);
return;
x_nomem:
qu->preserved_allocd= 0;
qu->answer->cname= 0;
qu->answer->owner= 0;
adns__reset_preserved(qu); /* (but we just threw away the preserved stuff) */
qu->answer->status= adns_s_nomemory;
free_query_allocs(qu);
}
void adns__query_done(adns_query qu) {
adns_answer *ans;
adns_query parent;
cancel_children(qu);
qu->id= -1;
ans= qu->answer;
if (qu->flags & adns_qf_owner && qu->flags & adns_qf_search &&
ans->status != adns_s_nomemory) {
if (!save_owner(qu, (const char *)qu->search_vb.buf, qu->search_vb.used)) {
adns__query_fail(qu,adns_s_nomemory);
return;
}
}
if (ans->nrrs && qu->typei->diff_needswap) {
if (!adns__vbuf_ensure(&qu->vb,qu->typei->rrsz)) {
adns__query_fail(qu,adns_s_nomemory);
return;
}
adns__isort(ans->rrs.bytes, ans->nrrs, ans->rrsz,
qu->vb.buf,
(int(*)(void*, const void*, const void*))qu->typei->diff_needswap,
qu->ads);
}
ans->expires= qu->expires;
parent= qu->parent;
if (parent) {
ADNS_LIST_UNLINK_PART(parent->children,qu,siblings.);
ADNS_LIST_UNLINK(qu->ads->childw,parent);
qu->ctx.callback(parent,qu);
free_query_allocs(qu);
free(qu->answer);
free(qu);
} else {
makefinal_query(qu);
ADNS_LIST_LINK_TAIL(qu->ads->output,qu);
qu->state= query_done;
}
}
void adns__query_fail(adns_query qu, adns_status stat) {
adns__reset_preserved(qu);
qu->answer->status= stat;
adns__query_done(qu);
}
void adns__makefinal_str(adns_query qu, char **strp) {
int l;
char *before, *after;
before= *strp;
if (!before) return;
l= strlen(before)+1;
after= adns__alloc_final(qu,l);
memcpy(after,before,l);
*strp= after;
}
void adns__makefinal_block(adns_query qu, void **blpp, size_t sz) {
void *before, *after;
before= *blpp;
if (!before) return;
after= adns__alloc_final(qu,sz);
memcpy(after,before,sz);
*blpp= after;
}
