X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=adns.git;a=blobdiff_plain;f=src%2Fquery.c;h=2bb52361720842c151ca43e73b2a2ae1c4e5ddb1;hp=890757ec692fa3d20eedcce75f2088935cc9d4ed;hb=0f15dd7b03058cb07e55d36ab36029081d556ffc;hpb=684420195d60f5421ea0b6350530fbd430ed8146 diff --git a/src/query.c b/src/query.c index 890757e..2bb5236 100644 --- a/src/query.c +++ b/src/query.c @@ -1,219 +1,574 @@ -/**/ +/* + * 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 + * + * It is part of adns, which is + * Copyright (C) 1997-2000 Ian Jackson + * Copyright (C) 1999-2000 Tony Finch + * + * 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 -#include #include +#include +#include -#include +#include #include "internal.h" -adns_status adns__mkquery(adns_state ads, vbuf *vb, - const char *owner, int ol, int *id_r, - const typeinfo *typei, adns_queryflags flags) { - int ll, c, nlabs, id; - byte label[255], *rqp; - const char *p, *pe; - -#define MKQUERY_ADDB(b) *rqp++= (b) -#define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff)) - - vb->used= 0; - if (!adns__vbuf_ensure(vb,DNS_HDRSIZE+strlen(owner)+1+5)) - return adns_s_nolocalmem; - rqp= vb->buf; - - *id_r= id= (ads->nextid++) & 0x0ffff; - - MKQUERY_ADDW(id); - MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */ - MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */ - MKQUERY_ADDW(1); /* QDCOUNT=1 */ - MKQUERY_ADDW(0); /* ANCOUNT=0 */ - MKQUERY_ADDW(0); /* NSCOUNT=0 */ - MKQUERY_ADDW(0); /* ARCOUNT=0 */ - p= owner; pe= owner+ol; - nlabs= 0; - if (!*p) return adns_s_invaliddomain; - do { - ll= 0; - while (p!=pe && (c= *p++)!='.') { - if (c=='\\') { - if (!(flags & adns_qf_anyquote)) return adns_s_invaliddomain; - if (ctype_digit(p[0])) { - if (ctype_digit(p[1]) && ctype_digit(p[2])) { - c= (*p++ - '0')*100 + (*p++ - '0')*10 + (*p++ - '0'); - if (c >= 256) return adns_s_invaliddomain; - } else { - return adns_s_invaliddomain; - } - } else if (!(c= *p++)) { - return adns_s_invaliddomain; - } - } - if (!(flags & adns_qf_anyquote)) { - if (ctype_digit(c) || c == '-') { - if (!ll) return adns_s_invaliddomain; - } else if (!ctype_alpha(c)) { - return adns_s_invaliddomain; - } - } - if (ll == sizeof(label)) return adns_s_invaliddomain; - label[ll++]= c; - } - if (!ll) return adns_s_invaliddomain; - if (nlabs++ > 63) return adns_s_invaliddomain; - MKQUERY_ADDB(ll); - memcpy(rqp,label,ll); rqp+= ll; - } while (p!=pe); - - MKQUERY_ADDB(0); - MKQUERY_ADDW(typei->type & adns__rrt_typemask); /* QTYPE */ - MKQUERY_ADDW(DNS_CLASS_IN); /* QCLASS=IN */ - - vb->used= rqp - vb->buf; - assert(vb->used <= vb->avail); +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; - return adns_s_ok; + 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= -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; } -void adns__query_tcp(adns_state ads, adns_query qu, struct timeval now) { - /* Query must be in state tcpwait/timew; it will be moved to a new state - * if possible and no further processing can be done on it for now. - * (Resulting state is one of tcpwait/timew (if server not connected), - * tcpsent/timew, child/childw or done/output.) - * - * adns__tcp_tryconnect should already have been called - _tcp - * will only use an existing connection (if there is one), which it - * may break. If the conn list lost then the caller is responsible for any - * reestablishment and retry. +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. */ - byte length[2]; - struct iovec iov[2]; - int wr, r; - if (ads->tcpstate != server_ok) return; + qu->vb= *qumsg_vb; + adns__vbuf_init(qumsg_vb); - length[0]= (qu->query_dglen&0x0ff00U) >>8; - length[1]= (qu->query_dglen&0x0ff); + qu->query_dgram= malloc(qu->vb.used); + if (!qu->query_dgram) { adns__query_fail(qu,adns_s_nomemory); return; } - if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2)) 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; +} - timevaladd(&now,TCPMS); - qu->timeout= now; - qu->state= query_tcpsent; - LIST_LINK_TAIL(ads->timew,qu); +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; - if (ads->tcpsend.used) { - wr= 0; + 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 { - iov[0].iov_base= length; - iov[0].iov_len= 2; - iov[1].iov_base= qu->query_dgram; - iov[1].iov_len= qu->query_dglen; - wr= writev(ads->tcpsocket,iov,2); - if (wr < 0) { - if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC || - errno == ENOBUFS || errno == ENOMEM)) { - adns__tcp_broken(ads,"write",strerror(errno)); - return; + if (qu->search_pos >= ads->nsearchlist) { + if (qu->search_doneabs) { + qu->search_vb.used= qu->search_origlen; + stat= adns_s_nxdomain; goto x_fail; + } else { + nextentry= 0; + qu->search_doneabs= 1; } - wr= 0; + } else { + nextentry= ads->searchlist[qu->search_pos++]; } } - if (wr<2) { - r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r); - wr= 0; + qu->search_vb.used= qu->search_origlen; + if (nextentry) { + if (!adns__vbuf_append(&qu->search_vb,".",1) || + !adns__vbuf_appendstr(&qu->search_vb,nextentry)) + goto x_nomemory; + } + + 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_nomemory: + stat= adns_s_nomemory; +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; + + if (!(qu->flags & adns_qf_owner)) return 1; + + 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 { - wr-= 2; + 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); } - if (wrquery_dglen) { - r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr); assert(r); + 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 query_usetcp(adns_state ads, adns_query qu, struct timeval now) { - timevaladd(&now,TCPMS); - qu->timeout= now; - qu->state= query_tcpwait; - LIST_LINK_TAIL(ads->timew,qu); - adns__query_tcp(ads,qu,now); - adns__tcp_tryconnect(ads,now); +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__query_udp(adns_state ads, adns_query qu, struct timeval now) { - /* Query must be in state udp/NONE; it will be moved to a new state, - * and no further processing can be done on it for now. - * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected), - * tcpsent/timew, child/childw or done/output.) +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); + + 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. */ - struct sockaddr_in servaddr; - int serv, r; + 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; - assert(qu->state == query_udp); - if ((qu->flags & adns_qf_usevc) || (qu->query_dglen > DNS_MAXUDP)) { - query_usetcp(ads,qu,now); - return; + 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); + qu->query_dgram= 0; +} + +void adns_cancel(adns_query qu) { + adns_state ads; - if (qu->udpretries >= UDPMAXRETRIES) { - adns__query_fail(ads,qu,adns_s_timeout); - return; + 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); +} - serv= qu->udpnextserver; - memset(&servaddr,0,sizeof(servaddr)); - servaddr.sin_family= AF_INET; - servaddr.sin_addr= ads->servers[serv].addr; - servaddr.sin_port= htons(DNS_PORT); - - r= sendto(ads->udpsocket,qu->query_dgram,qu->query_dglen,0,&servaddr,sizeof(servaddr)); - if (r<0 && errno == EMSGSIZE) { query_usetcp(ads,qu,now); return; } - if (r<0) adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno)); - - timevaladd(&now,UDPRETRYMS); - qu->timeout= now; - qu->udpsent |= (1<udpnextserver= (serv+1)%ads->nservers; - qu->udpretries++; - LIST_LINK_TAIL(ads->timew,qu); +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 adns__query_done(adns_state ads, adns_query qu) { +static void makefinal_query(adns_query qu) { adns_answer *ans; - allocnode *an, *ann; - int i; + int rrn; - qu->answer= ans= realloc(qu->answer, - MEM_ROUND(MEM_ROUND(sizeof(*ans)) + - qu->interim_allocd)); - qu->final_allocspace= (byte*)qu->answer + MEM_ROUND(sizeof(*ans)); + 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->rrsz*ans->nrrs); - for (i=0; inrrs; i++) - qu->typei->makefinal(ads,qu,ans->rrs.bytes+ans->rrsz*i); + adns__makefinal_block(qu, &ans->rrs.untyped, ans->nrrs*ans->rrsz); + + for (rrn=0; rrnnrrs; 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) */ - for (an= qu->allocations; an; an= ann) { ann= an->next; free(an); } + 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); - adns__vbuf_free(&qu->vb); - qu->id= -1; - LIST_LINK_TAIL(ads->output,qu); -} + ans= qu->answer; -void adns__reset_cnameonly(adns_state ads, adns_query qu) { - assert(qu->final_allocspace); - qu->answer->nrrs= 0; - qu->answer->rrs= 0; - qu->interim_allocd= qu->answer->cname ? MEM_ROUND(strlen(qu->answer->cname)+1) : 0; + if (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_state ads, adns_query qu, adns_status stat) { - adns__reset_cnameonly(ads,qu); +void adns__query_fail(adns_query qu, adns_status stat) { + adns__reset_preserved(qu); qu->answer->status= stat; - adns__query_done(ads,qu); + 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; }