[adns] / src / parse.c

/*
 * parse.c
 * - parsing assistance functions (mainly for domains inside datagrams)
 */
/*
 *  This file is part of adns, which is Copyright (C) 1997, 1998 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"

int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len) {
  char qbuf[10];
  int i, ch;
  
  while (len) {
    qbuf[0]= 0;
    for (i=0; i<len; i++) {
      ch= buf[i];
      if (ch == '.' || ch == '"' || ch == '(' || ch == ')' ||
	  ch == '@' || ch == ';' || ch == '$') {
	sprintf(qbuf,"\\%c",ch);
	break;
      } else if (ch <= ' ' || ch >= 127) {
	sprintf(qbuf,"\\%03o",ch);
	break;
      }
    }
    if (!adns__vbuf_append(vb,buf,i) || !adns__vbuf_append(vb,qbuf,strlen(qbuf)))
      return 0;
    buf+= i; len-= i;
  }
  return 1;
}

void adns__findlabel_start(findlabel_state *fls, adns_state ads,
			   int serv, adns_query qu,
			   const byte *dgram, int dglen, int max,
			   int dmbegin, int *dmend_rlater) {
  fls->ads= 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;
}

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 (fls->cbyte >= fls->dglen) goto x_truncated;
    if (fls->cbyte >= fls->max) goto x_serverfaulty;
    GET_B(fls->cbyte,lablen);
    if (!(lablen & 0x0c0)) break;
    if ((lablen & 0x0c0) != 0x0c0) return adns_s_unknownreply;
    if (jumped++) {
      adns__diag(fls->ads,fls->serv,fls->qu,"compressed datagram contains loop");
      return adns_s_serverfaulty;
    }
    if (fls->cbyte >= fls->dglen) goto x_truncated;
    if (fls->cbyte >= fls->max) goto x_serverfaulty;
    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= fls->cbyte;
  if (lablen) {
    if (fls->namelen) fls->namelen++;
    fls->namelen+= lablen;
    if (fls->namelen > DNS_MAXDOMAIN) return adns_s_domaintoolong;
    fls->cbyte+= lablen;
    if (fls->cbyte > fls->dglen) goto x_truncated;
    if (fls->cbyte > fls->max) goto x_serverfaulty;
  } else {
    if (fls->dmend_r) *(fls->dmend_r)= fls->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_serverfaulty: 
  adns__diag(fls->ads,fls->serv,fls->qu,"label in domain runs beyond end of domain");
  return adns_s_serverfaulty;
}

adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
			       vbuf *vb, int flags,
			       const byte *dgram, int dglen, int *cbyte_io, int max) {
  findlabel_state fls;
  
  int lablen, labstart, i, ch;
  adns_status st;

  adns__findlabel_start(&fls,ads, serv,qu, dgram,dglen,max, *cbyte_io,cbyte_io);
  vb->used= 0;
  for (;;) {
    st= adns__findlabel_next(&fls,&lablen,&labstart);
    if (st) return st;
    if (lablen<0) { vb->used=0; return adns_s_ok; }
    if (!lablen) break;
    if (vb->used)
      if (!adns__vbuf_append(vb,".",1)) return adns_s_nolocalmem;
    if (flags & adns_qf_anyquote) {
      if (!vbuf__append_quoted1035(vb,dgram+labstart,lablen))
	return adns_s_nolocalmem;
    } else {
      if (!ctype_alpha(dgram[labstart])) return adns_s_invaliddomain;
      for (i= labstart+1; i<labstart+lablen; i++) {
	ch= dgram[i];
	if (ch != '-' && !ctype_alpha(ch) && !ctype_digit(ch))
	  return adns_s_invaliddomain;
      }
      if (!adns__vbuf_append(vb,dgram+labstart,lablen))
	return adns_s_nolocalmem;
    }
  }
  if (!adns__vbuf_append(vb,"",1)) return adns_s_nolocalmem;
  return adns_s_ok;
}
	
static adns_status findrr_intern(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) {
  /* Like adns__findrr_checked, except that the datagram to compare
   * with can be specified explicitly.
   *
   * If the caller thinks they know what the owner of the RR ought to
   * be they can pass in details in eo_*: this is another (or perhaps
   * the same datagram), and a pointer to where the putative owner
   * starts in that datagram.  In this case *eo_matched_r will be set
   * to 1 if the datagram matched or 0 if it did not.  Either
   * both eo_dgram and eo_matched_r must both be non-null, or they
   * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
   * The eo datagram and contained owner domain MUST be valid and
   * untruncated.
   */
  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;

  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__findlabel_next(&fls,&lablen,&labstart);
    if (st) return st;
    if (lablen<0) goto x_truncated;

    if (!mismatch) {
      st= adns__findlabel_next(&eo_fls,&eo_lablen,&eo_labstart);
      assert(!st); assert(eo_lablen>=0);
      if (lablen != eo_lablen) mismatch= 1;
      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;
   
  if (cbyte+10>dglen) goto x_truncated;
  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= rdlen;
  if (rdstart_r) *rdstart_r= cbyte;
  cbyte+= rdlen;
  if (cbyte>dglen) goto x_truncated;
  *cbyte_io= cbyte;
  return adns_s_ok;

 x_truncated:
  *type_r= -1;
  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 findrr_intern(qu,serv,
			 dgram,dglen,cbyte_io,
			 type_r,class_r,rdlen_r,rdstart_r,
			 0,0,0, 0);
  } else if (!qu->cname_dgram) {
    return findrr_intern(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 findrr_intern(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);
  }
}
Commit	Line	Data
e576be50	1	/*
	2	* parse.c
	3	* - parsing assistance functions (mainly for domains inside datagrams)
	4	*/
	5	/*
	6	* This file is part of adns, which is Copyright (C) 1997, 1998 Ian Jackson
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2, or (at your option)
	11	* any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software Foundation,
	20	* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	21	*/
98a3f706	22
	23	#include "internal.h"
	24
	25	int vbuf__append_quoted1035(vbuf vb, const byte buf, int len) {
	26	char qbuf[10];
	27	int i, ch;
	28
	29	while (len) {
	30	qbuf[0]= 0;
	31	for (i=0; i<len; i++) {
	32	ch= buf[i];
	33	if (ch == '.' \|\| ch == '"' \|\| ch == '(' \|\| ch == ')' \|\|
	34	ch == '@' \|\| ch == ';' \|\| ch == '$') {
	35	sprintf(qbuf,"\\%c",ch);
	36	break;
	37	} else if (ch <= ' ' \|\| ch >= 127) {
	38	sprintf(qbuf,"\\%03o",ch);
	39	break;
	40	}
	41	}
	42	if (!adns__vbuf_append(vb,buf,i) \|\| !adns__vbuf_append(vb,qbuf,strlen(qbuf)))
	43	return 0;
	44	buf+= i; len-= i;
	45	}
	46	return 1;
	47	}
	48
3955725c	49	void adns__findlabel_start(findlabel_state *fls, adns_state ads,
3955725c	50	int serv, adns_query qu,
f1e474dd	51	const byte *dgram, int dglen, int max,
	52	int dmbegin, int *dmend_rlater) {
	53	fls->ads= ads;
3955725c	54	fls->qu= qu;
f1e474dd	55	fls->serv= serv;
	56	fls->dgram= dgram;
	57	fls->dglen= dglen;
	58	fls->max= max;
	59	fls->cbyte= dmbegin;
	60	fls->namelen= 0;
	61	fls->dmend_r= dmend_rlater;
f1e474dd	62	}
98a3f706	63
3955725c	64	adns_status adns__findlabel_next(findlabel_state *fls,
f1e474dd	65	int lablen_r, int labstart_r) {
86e7b8d9	66	int lablen, jumped, jumpto;
3955725c	67	const char *dgram;
f1e474dd	68
f1e474dd	69	jumped= 0;
3955725c	70	dgram= fls->dgram;
98a3f706	71	for (;;) {
86e7b8d9	72	if (fls->cbyte >= fls->dglen) goto x_truncated;
	73	if (fls->cbyte >= fls->max) goto x_serverfaulty;
	74	GET_B(fls->cbyte,lablen);
	75	if (!(lablen & 0x0c0)) break;
	76	if ((lablen & 0x0c0) != 0x0c0) return adns_s_unknownreply;
f1e474dd	77	if (jumped++) {
3955725c	78	adns__diag(fls->ads,fls->serv,fls->qu,"compressed datagram contains loop");
f1e474dd	79	return adns_s_serverfaulty;
f1e474dd	80	}
86e7b8d9	81	if (fls->cbyte >= fls->dglen) goto x_truncated;
	82	if (fls->cbyte >= fls->max) goto x_serverfaulty;
	83	GET_B(fls->cbyte,jumpto);
	84	jumpto \|= (lablen&0x3f)<<8;
f1e474dd	85	if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte;
86e7b8d9	86	fls->cbyte= jumpto;
f1e474dd	87	fls->dmend_r= 0; fls->max= fls->dglen+1;
98a3f706	88	}
86e7b8d9	89	if (labstart_r) *labstart_r= fls->cbyte;
98a3f706	90	if (lablen) {
f1e474dd	91	if (fls->namelen) fls->namelen++;
	92	fls->namelen+= lablen;
	93	if (fls->namelen > DNS_MAXDOMAIN) return adns_s_domaintoolong;
	94	fls->cbyte+= lablen;
	95	if (fls->cbyte > fls->dglen) goto x_truncated;
	96	if (fls->cbyte > fls->max) goto x_serverfaulty;
	97	} else {
	98	if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte;
98a3f706	99	}
98a3f706	100	*lablen_r= lablen;
86e7b8d9	101	/if (labstart_r) fprintf(stderr,"label %d >%.s<\n",lablen,lablen,fls->dgram+labstart_r);/
98a3f706	102	return adns_s_ok;
	103
	104	x_truncated:
	105	*lablen_r= -1;
	106	return adns_s_ok;
f1e474dd	107
f1e474dd	108	x_serverfaulty:
3955725c	109	adns__diag(fls->ads,fls->serv,fls->qu,"label in domain runs beyond end of domain");
f1e474dd	110	return adns_s_serverfaulty;
98a3f706	111	}
98a3f706	112
3955725c	113	adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
	114	vbuf *vb, int flags,
	115	const byte dgram, int dglen, int cbyte_io, int max) {
f1e474dd	116	findlabel_state fls;
f1e474dd	117
3955725c	118	int lablen, labstart, i, ch;
98a3f706	119	adns_status st;
98a3f706	120
3955725c	121	adns__findlabel_start(&fls,ads, serv,qu, dgram,dglen,max, *cbyte_io,cbyte_io);
f1e474dd	122	vb->used= 0;
98a3f706	123	for (;;) {
f1e474dd	124	st= adns__findlabel_next(&fls,&lablen,&labstart);
98a3f706	125	if (st) return st;
f1e474dd	126	if (lablen<0) { vb->used=0; return adns_s_ok; }
98a3f706	127	if (!lablen) break;
f1e474dd	128	if (vb->used)
3955725c	129	if (!adns__vbuf_append(vb,".",1)) return adns_s_nolocalmem;
31144a72	130	if (flags & adns_qf_anyquote) {
3955725c	131	if (!vbuf__append_quoted1035(vb,dgram+labstart,lablen))
98a3f706	132	return adns_s_nolocalmem;
	133	} else {
	134	if (!ctype_alpha(dgram[labstart])) return adns_s_invaliddomain;
f1e474dd	135	for (i= labstart+1; i<labstart+lablen; i++) {
f1e474dd	136	ch= dgram[i];
98a3f706	137	if (ch != '-' && !ctype_alpha(ch) && !ctype_digit(ch))
	138	return adns_s_invaliddomain;
	139	}
3955725c	140	if (!adns__vbuf_append(vb,dgram+labstart,lablen))
98a3f706	141	return adns_s_nolocalmem;
	142	}
	143	}
3955725c	144	if (!adns__vbuf_append(vb,"",1)) return adns_s_nolocalmem;
98a3f706	145	return adns_s_ok;
98a3f706	146	}
31144a72	147
3955725c	148	static adns_status findrr_intern(adns_query qu, int serv,
	149	const byte dgram, int dglen, int cbyte_io,
	150	int type_r, int class_r, int rdlen_r, int rdstart_r,
	151	const byte *eo_dgram, int eo_dglen, int eo_cbyte,
	152	int *eo_matched_r) {
	153	/* Like adns__findrr_checked, except that the datagram to compare
	154	* with can be specified explicitly.
f1e474dd	155	*
	156	* If the caller thinks they know what the owner of the RR ought to
	157	* be they can pass in details in eo_*: this is another (or perhaps
	158	* the same datagram), and a pointer to where the putative owner
	159	* starts in that datagram. In this case *eo_matched_r will be set
	160	* to 1 if the datagram matched or 0 if it did not. Either
	161	* both eo_dgram and eo_matched_r must both be non-null, or they
	162	* must both be null (in which case eo_dglen and eo_cbyte will be ignored).
	163	* The eo datagram and contained owner domain MUST be valid and
	164	* untruncated.
98a3f706	165	*/
f1e474dd	166	findlabel_state fls, eo_fls;
	167	int cbyte;
	168
	169	int tmp, rdlen, mismatch;
3955725c	170	int lablen, labstart, ch;
3955725c	171	int eo_lablen, eo_labstart, eo_ch;
98a3f706	172	adns_status st;
	173
	174	cbyte= *cbyte_io;
98a3f706	175
3955725c	176	adns__findlabel_start(&fls,qu->ads, serv,qu, dgram,dglen,dglen,cbyte,&cbyte);
f1e474dd	177	if (eo_dgram) {
3955725c	178	adns__findlabel_start(&eo_fls,qu->ads, -1,0, eo_dgram,eo_dglen,eo_dglen,eo_cbyte,0);
f1e474dd	179	mismatch= 0;
	180	} else {
	181	mismatch= 1;
	182	}
	183
98a3f706	184	for (;;) {
f1e474dd	185	st= adns__findlabel_next(&fls,&lablen,&labstart);
98a3f706	186	if (st) return st;
	187	if (lablen<0) goto x_truncated;
	188
	189	if (!mismatch) {
f1e474dd	190	st= adns__findlabel_next(&eo_fls,&eo_lablen,&eo_labstart);
f1e474dd	191	assert(!st); assert(eo_lablen>=0);
98a3f706	192	if (lablen != eo_lablen) mismatch= 1;
86e7b8d9	193	while (!mismatch && eo_lablen-- > 0) {
98a3f706	194	ch= dgram[labstart++]; if (ctype_alpha(ch)) ch &= ~32;
	195	eo_ch= eo_dgram[eo_labstart++]; if (ctype_alpha(eo_ch)) eo_ch &= ~32;
	196	if (ch != eo_ch) mismatch= 1;
	197	}
	198	}
86e7b8d9	199	if (!lablen) break;
98a3f706	200	}
	201	if (eo_matched_r) *eo_matched_r= !mismatch;
	202
	203	if (cbyte+10>dglen) goto x_truncated;
	204	GET_W(cbyte,tmp); *type_r= tmp;
	205	GET_W(cbyte,tmp); *class_r= tmp;
	206	cbyte+= 4; /* we skip the TTL */
86e7b8d9	207	GET_W(cbyte,rdlen); if (rdlen_r) *rdlen_r= rdlen;
98a3f706	208	if (rdstart_r) *rdstart_r= cbyte;
	209	cbyte+= rdlen;
	210	if (cbyte>dglen) goto x_truncated;
	211	*cbyte_io= cbyte;
	212	return adns_s_ok;
	213
	214	x_truncated:
	215	*type_r= -1;
86e7b8d9	216	return 0;
98a3f706	217	}
3955725c	218
	219	adns_status adns__findrr(adns_query qu, int serv,
	220	const byte dgram, int dglen, int cbyte_io,
	221	int type_r, int class_r, int rdlen_r, int rdstart_r,
	222	int *ownermatchedquery_r) {
	223	if (!ownermatchedquery_r) {
	224	return findrr_intern(qu,serv,
	225	dgram,dglen,cbyte_io,
	226	type_r,class_r,rdlen_r,rdstart_r,
	227	0,0,0, 0);
	228	} else if (!qu->cname_dgram) {
	229	return findrr_intern(qu,serv,
	230	dgram,dglen,cbyte_io,
	231	type_r,class_r,rdlen_r,rdstart_r,
	232	qu->query_dgram,qu->query_dglen,DNS_HDRSIZE,
	233	ownermatchedquery_r);
	234	} else {
	235	return findrr_intern(qu,serv,
	236	dgram,dglen,cbyte_io,
	237	type_r,class_r,rdlen_r,rdstart_r,
	238	qu->cname_dgram,qu->cname_dglen,qu->cname_begin,
	239	ownermatchedquery_r);
	240	}
	241	}