diff options
Diffstat (limited to 'adns-0.6/src/query.c')
-rw-r--r-- | adns-0.6/src/query.c | 540 |
1 files changed, 540 insertions, 0 deletions
diff --git a/adns-0.6/src/query.c b/adns-0.6/src/query.c new file mode 100644 index 0000000..37306d1 --- /dev/null +++ b/adns-0.6/src/query.c @@ -0,0 +1,540 @@ +/* + * query.c + * - overall query management (allocation, completion) + * - per-query memory management + * - query submission and cancellation (user-visible and internal) + */ +/* + * This file is + * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk> + * + * It is part of adns, which is + * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk> + * Copyright (C) 1999 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 "internal.h" + +#include <stdlib.h> +#include <unistd.h> +#include <errno.h> + +#include <sys/time.h> + +#include "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; + LIST_INIT(qu->children); + LINK_INIT(qu->siblings); + 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= 0; + 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; + int id; + adns_status stat; + + vb= qu->vb; + + stat= adns__mkquery(ads,&vb,&id, owner,ol, typei,flags); + if (stat) { adns__query_fail(qu,stat); return; } + + query_submit(ads,qu, typei,&vb,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,".",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, 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,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(adns_state ads, + const struct sockaddr *addr, + adns_rrtype type, + adns_queryflags flags, + void *context, + adns_query *query_r) { + const unsigned char *iaddr; + char buf[30]; + + if (type != adns_r_ptr && type != adns_r_ptr_raw) return EINVAL; + flags &= ~adns_qf_search; + + if (addr->sa_family != AF_INET) return ENOSYS; + iaddr= (const unsigned char*) &(((const struct sockaddr_in*)addr) -> sin_addr); + + sprintf(buf, "%d.%d.%d.%d.in-addr.arpa", + iaddr[3], iaddr[2], iaddr[1], iaddr[0]); + + return adns_submit(ads,buf,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; + 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); + + LIST_UNLINK(from->allocations,an); + LIST_LINK_TAIL(to->allocations,an); + + 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); } + LIST_INIT(qu->allocations); + adns__vbuf_free(&qu->vb); + adns__vbuf_free(&qu->search_vb); + free(qu->query_dgram); +} + +void adns_cancel(adns_query qu) { + adns_state ads; + + ads= qu->ads; + adns__consistency(ads,qu,cc_entex); + if (qu->parent) LIST_UNLINK_PART(qu->parent->children,qu,siblings.); + switch (qu->state) { + case query_tosend: + LIST_UNLINK(ads->udpw,qu); + break; + case query_tcpw: + LIST_UNLINK(ads->tcpw,qu); + break; + case query_childw: + LIST_UNLINK(ads->childw,qu); + break; + case query_done: + 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, 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) { + LIST_UNLINK_PART(parent->children,qu,siblings.); + LIST_UNLINK(qu->ads->childw,parent); + qu->ctx.callback(parent,qu); + free_query_allocs(qu); + free(qu->answer); + free(qu); + } else { + makefinal_query(qu); + 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; +} |