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Member "libspf2-1.2.10/src/libreplace/__ns_initparse.c" (28 Jan 2012, 5260 Bytes) of package /linux/privat/libspf2-1.2.10.tar.gz:


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    1 /*
    2  * Copyright (c) 1996,1999 by Internet Software Consortium.
    3  *
    4  * Permission to use, copy, modify, and distribute this software for any
    5  * purpose with or without fee is hereby granted, provided that the above
    6  * copyright notice and this permission notice appear in all copies.
    7  *
    8  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
    9  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
   10  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
   11  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
   12  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
   13  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
   14  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
   15  * SOFTWARE.
   16  */
   17 
   18 #ifndef lint
   19 static const char rcsid[] = "$Id: ns_parse.c,v 1.3.2.1 2003/06/27 03:51:42 marka Exp $";
   20 #endif
   21 
   22 /* Import. */
   23 
   24 /* #include "port_before.h" */
   25 #include "config.h"
   26 
   27 #include <sys/types.h>
   28 
   29 #include <netinet/in.h>
   30 #include "arpa_nameser.h"
   31 
   32 #include <errno.h>
   33 /* #include <resolv.h> */
   34 #ifdef HAVE_STRING_H
   35 # include <string.h>       /* strstr / strdup */
   36 #else
   37 # ifdef HAVE_STRINGS_H
   38 #  include <strings.h>       /* strstr / strdup */
   39 # endif
   40 #endif
   41 
   42 
   43 /* #include "port_after.h" */
   44 
   45 /* Forward. */
   46 
   47 static void setsection(ns_msg *msg, ns_sect sect);
   48 
   49 /* Macros. */
   50 
   51 #define RETERR(err) do { errno = (err); return (-1); } while (0)
   52 
   53 /* Public. */
   54 
   55 /* These need to be in the same order as the nres.h:ns_flag enum. */
   56 struct _ns_flagdata _ns_flagdata[16] = {
   57     { 0x8000, 15 },     /* qr. */
   58     { 0x7800, 11 },     /* opcode. */
   59     { 0x0400, 10 },     /* aa. */
   60     { 0x0200, 9 },      /* tc. */
   61     { 0x0100, 8 },      /* rd. */
   62     { 0x0080, 7 },      /* ra. */
   63     { 0x0040, 6 },      /* z. */
   64     { 0x0020, 5 },      /* ad. */
   65     { 0x0010, 4 },      /* cd. */
   66     { 0x000f, 0 },      /* rcode. */
   67     { 0x0000, 0 },      /* expansion (1/6). */
   68     { 0x0000, 0 },      /* expansion (2/6). */
   69     { 0x0000, 0 },      /* expansion (3/6). */
   70     { 0x0000, 0 },      /* expansion (4/6). */
   71     { 0x0000, 0 },      /* expansion (5/6). */
   72     { 0x0000, 0 },      /* expansion (6/6). */
   73 };
   74 
   75 int
   76 ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) {
   77     const u_char *optr = ptr;
   78 
   79     for ((void)NULL; count > 0; count--) {
   80         int b, rdlength;
   81 
   82         b = dn_skipname(ptr, eom);
   83         if (b < 0)
   84             RETERR(EMSGSIZE);
   85         ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/;
   86         if (section != ns_s_qd) {
   87             if (ptr + NS_INT32SZ + NS_INT16SZ > eom)
   88                 RETERR(EMSGSIZE);
   89             ptr += NS_INT32SZ/*TTL*/;
   90             NS_GET16(rdlength, ptr);
   91             ptr += rdlength/*RData*/;
   92         }
   93     }
   94     if (ptr > eom)
   95         RETERR(EMSGSIZE);
   96     return (ptr - optr);
   97 }
   98 
   99 int
  100 ns_initparse(const u_char *msg, int msglen, ns_msg *handle) {
  101     const u_char *eom = msg + msglen;
  102     int i;
  103 
  104     memset(handle, 0x5e, sizeof *handle);
  105     handle->_msg = msg;
  106     handle->_eom = eom;
  107     if (msg + NS_INT16SZ > eom)
  108         RETERR(EMSGSIZE);
  109     NS_GET16(handle->_id, msg);
  110     if (msg + NS_INT16SZ > eom)
  111         RETERR(EMSGSIZE);
  112     NS_GET16(handle->_flags, msg);
  113     for (i = 0; i < ns_s_max; i++) {
  114         if (msg + NS_INT16SZ > eom)
  115             RETERR(EMSGSIZE);
  116         NS_GET16(handle->_counts[i], msg);
  117     }
  118     for (i = 0; i < ns_s_max; i++)
  119         if (handle->_counts[i] == 0)
  120             handle->_sections[i] = NULL;
  121         else {
  122             int b = ns_skiprr(msg, eom, (ns_sect)i,
  123                       handle->_counts[i]);
  124 
  125             if (b < 0)
  126                 return (-1);
  127             handle->_sections[i] = msg;
  128             msg += b;
  129         }
  130     if (msg != eom)
  131         RETERR(EMSGSIZE);
  132     setsection(handle, ns_s_max);
  133     return (0);
  134 }
  135 
  136 int
  137 ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) {
  138     int b;
  139     int tmp;
  140 
  141     /* Make section right. */
  142     if ((tmp = section) < 0 || section >= ns_s_max)
  143         RETERR(ENODEV);
  144     if (section != handle->_sect)
  145         setsection(handle, section);
  146 
  147     /* Make rrnum right. */
  148     if (rrnum == -1)
  149         rrnum = handle->_rrnum;
  150     if (rrnum < 0 || rrnum >= handle->_counts[(int)section])
  151         RETERR(ENODEV);
  152     if (rrnum < handle->_rrnum)
  153         setsection(handle, section);
  154     if (rrnum > handle->_rrnum) {
  155         b = ns_skiprr(handle->_msg_ptr, handle->_eom, section,
  156                   rrnum - handle->_rrnum);
  157 
  158         if (b < 0)
  159             return (-1);
  160         handle->_msg_ptr += b;
  161         handle->_rrnum = rrnum;
  162     }
  163 
  164     /* Do the parse. */
  165     b = dn_expand(handle->_msg, handle->_eom,
  166               handle->_msg_ptr, rr->name, NS_MAXDNAME);
  167     if (b < 0)
  168         return (-1);
  169     handle->_msg_ptr += b;
  170     if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom)
  171         RETERR(EMSGSIZE);
  172     NS_GET16(rr->type, handle->_msg_ptr);
  173     NS_GET16(rr->rr_class, handle->_msg_ptr);
  174     if (section == ns_s_qd) {
  175         rr->ttl = 0;
  176         rr->rdlength = 0;
  177         rr->rdata = NULL;
  178     } else {
  179         if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom)
  180             RETERR(EMSGSIZE);
  181         NS_GET32(rr->ttl, handle->_msg_ptr);
  182         NS_GET16(rr->rdlength, handle->_msg_ptr);
  183         if (handle->_msg_ptr + rr->rdlength > handle->_eom)
  184             RETERR(EMSGSIZE);
  185         rr->rdata = handle->_msg_ptr;
  186         handle->_msg_ptr += rr->rdlength;
  187     }
  188     if (++handle->_rrnum > handle->_counts[(int)section])
  189         setsection(handle, (ns_sect)((int)section + 1));
  190 
  191     /* All done. */
  192     return (0);
  193 }
  194 
  195 /* Private. */
  196 
  197 static void
  198 setsection(ns_msg *msg, ns_sect sect) {
  199     msg->_sect = sect;
  200     if (sect == ns_s_max) {
  201         msg->_rrnum = -1;
  202         msg->_msg_ptr = NULL;
  203     } else {
  204         msg->_rrnum = 0;
  205         msg->_msg_ptr = msg->_sections[(int)sect];
  206     }
  207 }