X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=adns.git;a=blobdiff_plain;f=src%2Fparse.c;h=22d9d96cea3fb4269b5420955c8a3925abc321c3;hp=2a9dd94b327462959be98d87ffbcbd6d0c3f2ac5;hb=a719a4bedec2bc512b7f95f7446e02f6662ebbc7;hpb=98a3f706175de88b2c9f0729b405330457ae680b diff --git a/src/parse.c b/src/parse.c index 2a9dd94..22d9d96 100644 --- a/src/parse.c +++ b/src/parse.c @@ -1,4 +1,24 @@ -/**/ +/* + * parse.c + * - parsing assistance functions (mainly for domains inside datagrams) + */ +/* + * This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson + * + * 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" @@ -11,7 +31,7 @@ int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len) { for (i=0; i= 127) { @@ -21,144 +41,152 @@ int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len) { } if (!adns__vbuf_append(vb,buf,i) || !adns__vbuf_append(vb,qbuf,strlen(qbuf))) return 0; - buf+= i; len-= i; + if (iads= ads; + fls->qu= qu; + fls->serv= serv; + fls->dgram= dgram; + fls->dglen= dglen; + fls->max= max; + fls->cbyte= dmbegin; + fls->namelen= 0; + fls->dmend_r= dmend_rlater; +} - max= *max_io; - cbyte= *cbyte_io; - +adns_status adns__findlabel_next(findlabel_state *fls, + int *lablen_r, int *labstart_r) { + int lablen, jumped, jumpto; + const char *dgram; + + jumped= 0; + dgram= fls->dgram; for (;;) { - if (cbyte+2 > max) goto x_truncated; - GET_W(cbyte,lablen); - if (!(lablen & 0x0c000)) break; - if ((lablen & 0x0c000) != 0x0c000) return adns_s_unknownreply; - if (cbyte_io) { *cbyte_io= cbyte; cbyte_io= 0; } - cbyte= DNS_HDRSIZE+(lablen&0x3fff); - *max_io= max= dglen; + if (fls->cbyte >= fls->dglen) goto x_truncated; + if (fls->cbyte >= fls->max) goto x_badresponse; + GET_B(fls->cbyte,lablen); + if (!(lablen & 0x0c0)) break; + if ((lablen & 0x0c0) != 0x0c0) return adns_s_unknownformat; + if (jumped++) { + adns__diag(fls->ads,fls->serv,fls->qu,"compressed datagram contains loop"); + return adns_s_invalidresponse; + } + if (fls->cbyte >= fls->dglen) goto x_truncated; + if (fls->cbyte >= fls->max) goto x_badresponse; + GET_B(fls->cbyte,jumpto); + jumpto |= (lablen&0x3f)<<8; + if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte; + fls->cbyte= jumpto; + fls->dmend_r= 0; fls->max= fls->dglen+1; } - if (labstart_r) *labstart_r= cbyte; + if (labstart_r) *labstart_r= fls->cbyte; if (lablen) { - namelen= *namelen_io; - if (namelen) namelen++; - namelen+= lablen; - if (namelen > DNS_MAXDOMAIN) return adns_s_domaintoolong; - *namelen_io= namelen; - cbyte+= lablen; - if (cbyte > max) goto x_truncated; + if (fls->namelen) fls->namelen++; + fls->namelen+= lablen; + if (fls->namelen > DNS_MAXDOMAIN) return adns_s_answerdomaintoolong; + fls->cbyte+= lablen; + if (fls->cbyte > fls->dglen) goto x_truncated; + if (fls->cbyte > fls->max) goto x_badresponse; + } else { + if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte; } - if (cbyte_io) *cbyte_io= cbyte; *lablen_r= lablen; +/*if (labstart_r) fprintf(stderr,"label %d >%.*s<\n",lablen,lablen,fls->dgram+*labstart_r);*/ return adns_s_ok; x_truncated: *lablen_r= -1; return adns_s_ok; + + x_badresponse: + adns__diag(fls->ads,fls->serv,fls->qu,"label in domain runs beyond end of domain"); + return adns_s_invalidresponse; } -adns_status adns__get_domain_perm(adns_state ads, adns_query qu, int serv, - const byte *dgram, int dglen, - int *cbyte_io, int max, int *domainstart_r) { - /* Returns 0 for OK (*domainstart_r >=0) or truncated (*domainstart_r == -1) - * or any other adns_s_* value. - */ - int cbyte, sused, lablen, labstart, namelen, i, ch; +adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu, + vbuf *vb, adns_queryflags flags, + const byte *dgram, int dglen, int *cbyte_io, int max) { + findlabel_state fls; + + int lablen, labstart, i, ch; adns_status st; - /* If we follow a pointer we set cbyte_io to 0 to indicate that - * we've lost our original starting and ending points; we don't - * put the end of the pointed-to thing into the original *cbyte_io. - */ - cbyte= *cbyte_io; - sused= qu->ans.used; - namelen= 0; + adns__findlabel_start(&fls,ads, serv,qu, dgram,dglen,max, *cbyte_io,cbyte_io); + vb->used= 0; for (;;) { - st= adns__get_label(dgram,dglen,&max, &cbyte,&lablen,&labstart,&namelen); + st= adns__findlabel_next(&fls,&lablen,&labstart); if (st) return st; - if (lablen<0) goto x_truncated; + if (lablen<0) { vb->used=0; return adns_s_ok; } if (!lablen) break; - if (qu->ans.used != sused) - if (!adns__vbuf_append(&qu->ans,".",1)) return adns_s_nolocalmem; - if (qu->flags & adns_qf_anyquote) { - if (!vbuf__append_quoted1035(&qu->ans,dgram+labstart,lablen)) - return adns_s_nolocalmem; + if (vb->used) + if (!adns__vbuf_append(vb,".",1)) return adns_s_nomemory; + if (flags & pdf_quoteok) { + if (!vbuf__append_quoted1035(vb,dgram+labstart,lablen)) + return adns_s_nomemory; } else { - if (!ctype_alpha(dgram[labstart])) return adns_s_invaliddomain; - for (i= cbyte+1; ians,dgram+labstart,lablen)) - return adns_s_nolocalmem; + if (!adns__vbuf_append(vb,dgram+labstart,lablen)) + return adns_s_nomemory; } } - if (cbyte_io) *cbyte_io= cbyte; - if (!adns__vbuf_append(&qu->ans,"",1)) return adns_s_nolocalmem; - *domainstart_r= sused; + if (!adns__vbuf_append(vb,"",1)) return adns_s_nomemory; return adns_s_ok; - - x_truncated: - *domainstart_r= -1; - return cbyte_io ? -1 : adns_s_serverfaulty; } - -adns_status adns__get_domain_temp(adns_state ads, adns_query qu, int serv, - const byte *dgram, int dglen, - int *cbyte_io, int max, int *domainstart_r) { - int sused; - adns_status st; - - sused= qu->ans.used; - st= adns__get_domain_perm(ads,qu,serv,dgram,dglen,cbyte_io,max,domainstart_r); - qu->ans.used= sused; - return st; -} - -adns_status adns__get_rr_temp(adns_state ads, adns_query qu, int serv, - const byte *dgram, int dglen, int *cbyte_io, - int *type_r, int *class_r, int *rdlen_r, int *rdstart_r, - const byte *eo_dgram, int eo_dglen, int eo_cbyte, - int *eo_matched_r) { - /* _s_ok can have *type_r == -1 and other output invalid, for truncation - * type_r and class_r must be !0, other _r may be 0. - * eo_dgram==0 for no comparison, otherwise all eo_ must be valid. - */ - int cbyte, tmp, rdlen, mismatch; - int max, lablen, labstart, namelen, ch; - int eo_max, eo_lablen, eo_labstart, eo_namelen, eo_ch; + +adns_status adns__findrr_anychk(adns_query qu, int serv, + const byte *dgram, int dglen, int *cbyte_io, + int *type_r, int *class_r, int *rdlen_r, int *rdstart_r, + const byte *eo_dgram, int eo_dglen, int eo_cbyte, + int *eo_matched_r) { + findlabel_state fls, eo_fls; + int cbyte; + + int tmp, rdlen, mismatch; + int lablen, labstart, ch; + int eo_lablen, eo_labstart, eo_ch; adns_status st; cbyte= *cbyte_io; - mismatch= eo_dgram ? 1 : 0; - namelen= 0; eo_namelen= 0; - max= dglen; eo_max= eo_dglen; + adns__findlabel_start(&fls,qu->ads, serv,qu, dgram,dglen,dglen,cbyte,&cbyte); + if (eo_dgram) { + adns__findlabel_start(&eo_fls,qu->ads, -1,0, eo_dgram,eo_dglen,eo_dglen,eo_cbyte,0); + mismatch= 0; + } else { + mismatch= 1; + } + for (;;) { - st= adns__get_label(dgram,dglen,&max, - &cbyte,&lablen,&labstart,&namelen); + st= adns__findlabel_next(&fls,&lablen,&labstart); if (st) return st; if (lablen<0) goto x_truncated; if (!mismatch) { - st= adns__get_label(eo_dgram,eo_dglen,&eo_max, - &eo_cbyte,&eo_lablen,&eo_labstart,&eo_namelen); - if (st) return st; - assert(eo_lablen>=0); + st= adns__findlabel_next(&eo_fls,&eo_lablen,&eo_labstart); + assert(!st); assert(eo_lablen>=0); if (lablen != eo_lablen) mismatch= 1; - while (!mismatch && lablen-- > 0) { + while (!mismatch && eo_lablen-- > 0) { ch= dgram[labstart++]; if (ctype_alpha(ch)) ch &= ~32; eo_ch= eo_dgram[eo_labstart++]; if (ctype_alpha(eo_ch)) eo_ch &= ~32; if (ch != eo_ch) mismatch= 1; } } + if (!lablen) break; } if (eo_matched_r) *eo_matched_r= !mismatch; @@ -166,7 +194,7 @@ adns_status adns__get_rr_temp(adns_state ads, adns_query qu, int serv, GET_W(cbyte,tmp); *type_r= tmp; GET_W(cbyte,tmp); *class_r= tmp; cbyte+= 4; /* we skip the TTL */ - GET_W(cbyte,rdlen); if (rdlen_r) *rdlen_r= tmp; + GET_W(cbyte,rdlen); if (rdlen_r) *rdlen_r= rdlen; if (rdstart_r) *rdstart_r= cbyte; cbyte+= rdlen; if (cbyte>dglen) goto x_truncated; @@ -175,5 +203,29 @@ adns_status adns__get_rr_temp(adns_state ads, adns_query qu, int serv, x_truncated: *type_r= -1; - return 0;; + return 0; +} + +adns_status adns__findrr(adns_query qu, int serv, + const byte *dgram, int dglen, int *cbyte_io, + int *type_r, int *class_r, int *rdlen_r, int *rdstart_r, + int *ownermatchedquery_r) { + if (!ownermatchedquery_r) { + return adns__findrr_anychk(qu,serv, + dgram,dglen,cbyte_io, + type_r,class_r,rdlen_r,rdstart_r, + 0,0,0, 0); + } else if (!qu->cname_dgram) { + return adns__findrr_anychk(qu,serv, + dgram,dglen,cbyte_io, + type_r,class_r,rdlen_r,rdstart_r, + qu->query_dgram,qu->query_dglen,DNS_HDRSIZE, + ownermatchedquery_r); + } else { + return adns__findrr_anychk(qu,serv, + dgram,dglen,cbyte_io, + type_r,class_r,rdlen_r,rdstart_r, + qu->cname_dgram,qu->cname_dglen,qu->cname_begin, + ownermatchedquery_r); + } }