1 /* 2 * Copyright 2003 Sun Microsystems, Inc. All rights reserved. 3 * Use is subject to license terms. 4 */ 5 6 /* 7 * Copyright (c) 1996,1999 by Internet Software Consortium. 8 * 9 * Permission to use, copy, modify, and distribute this software for any 10 * purpose with or without fee is hereby granted, provided that the above 11 * copyright notice and this permission notice appear in all copies. 12 * 13 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS 14 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES 15 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE 16 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 17 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 18 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 19 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 20 * SOFTWARE. 21 */ 22 23 #pragma ident "%Z%%M% %I% %E% SMI" 24 25 #ifndef lint 26 static const char rcsid[] = "$Id: ns_parse.c,v 8.18 2003/04/03 06:10:10 marka Exp $"; 27 #endif 28 29 /* Import. */ 30 31 #include "port_before.h" 32 33 #include <sys/types.h> 34 35 #include <netinet/in.h> 36 #include <arpa/nameser.h> 37 38 #include <errno.h> 39 #include <resolv.h> 40 #include <string.h> 41 42 #include "port_after.h" 43 44 /* Forward. */ 45 46 static void setsection(ns_msg *msg, ns_sect sect); 47 48 /* Macros. */ 49 50 #ifdef ORIGINAL_ISC_CODE 51 #define RETERR(err) do { errno = (err); return (-1); } while (0) 52 #else 53 #define RETERR(err) { errno = (err); return (-1); } 54 #endif 55 56 /* Public. */ 57 58 /* These need to be in the same order as the nres.h:ns_flag enum. */ 59 struct _ns_flagdata _ns_flagdata[16] = { 60 { 0x8000, 15 }, /* qr. */ 61 { 0x7800, 11 }, /* opcode. */ 62 { 0x0400, 10 }, /* aa. */ 63 { 0x0200, 9 }, /* tc. */ 64 { 0x0100, 8 }, /* rd. */ 65 { 0x0080, 7 }, /* ra. */ 66 { 0x0040, 6 }, /* z. */ 67 { 0x0020, 5 }, /* ad. */ 68 { 0x0010, 4 }, /* cd. */ 69 { 0x000f, 0 }, /* rcode. */ 70 { 0x0000, 0 }, /* expansion (1/6). */ 71 { 0x0000, 0 }, /* expansion (2/6). */ 72 { 0x0000, 0 }, /* expansion (3/6). */ 73 { 0x0000, 0 }, /* expansion (4/6). */ 74 { 0x0000, 0 }, /* expansion (5/6). */ 75 { 0x0000, 0 }, /* expansion (6/6). */ 76 }; 77 78 int ns_msg_getflag(ns_msg handle, int flag) { 79 return(((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift); 80 } 81 82 int 83 ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) { 84 const u_char *optr = ptr; 85 86 for ((void)NULL; count > 0; count--) { 87 int b, rdlength; 88 89 b = dn_skipname(ptr, eom); 90 if (b < 0) 91 RETERR(EMSGSIZE); 92 ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/; 93 if (section != ns_s_qd) { 94 if (ptr + NS_INT32SZ + NS_INT16SZ > eom) 95 RETERR(EMSGSIZE); 96 ptr += NS_INT32SZ/*TTL*/; 97 NS_GET16(rdlength, ptr); 98 ptr += rdlength/*RData*/; 99 } 100 } 101 if (ptr > eom) 102 RETERR(EMSGSIZE); 103 return (ptr - optr); 104 } 105 106 int 107 ns_initparse(const u_char *msg, int msglen, ns_msg *handle) { 108 const u_char *eom = msg + msglen; 109 int i; 110 111 memset(handle, 0x5e, sizeof *handle); 112 handle->_msg = msg; 113 handle->_eom = eom; 114 if (msg + NS_INT16SZ > eom) 115 RETERR(EMSGSIZE); 116 NS_GET16(handle->_id, msg); 117 if (msg + NS_INT16SZ > eom) 118 RETERR(EMSGSIZE); 119 NS_GET16(handle->_flags, msg); 120 for (i = 0; i < ns_s_max; i++) { 121 if (msg + NS_INT16SZ > eom) 122 RETERR(EMSGSIZE); 123 NS_GET16(handle->_counts[i], msg); 124 } 125 for (i = 0; i < ns_s_max; i++) 126 if (handle->_counts[i] == 0) 127 handle->_sections[i] = NULL; 128 else { 129 int b = ns_skiprr(msg, eom, (ns_sect)i, 130 handle->_counts[i]); 131 132 if (b < 0) 133 return (-1); 134 handle->_sections[i] = msg; 135 msg += b; 136 } 137 if (msg != eom) 138 RETERR(EMSGSIZE); 139 setsection(handle, ns_s_max); 140 return (0); 141 } 142 143 int 144 ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) { 145 int b; 146 int tmp; 147 148 /* Make section right. */ 149 if ((tmp = section) < 0 || section >= ns_s_max) 150 RETERR(ENODEV); 151 if (section != handle->_sect) 152 setsection(handle, section); 153 154 /* Make rrnum right. */ 155 if (rrnum == -1) 156 rrnum = handle->_rrnum; 157 if (rrnum < 0 || rrnum >= handle->_counts[(int)section]) 158 RETERR(ENODEV); 159 if (rrnum < handle->_rrnum) 160 setsection(handle, section); 161 if (rrnum > handle->_rrnum) { 162 b = ns_skiprr(handle->_msg_ptr, handle->_eom, section, 163 rrnum - handle->_rrnum); 164 165 if (b < 0) 166 return (-1); 167 handle->_msg_ptr += b; 168 handle->_rrnum = rrnum; 169 } 170 171 /* Do the parse. */ 172 b = dn_expand(handle->_msg, handle->_eom, 173 handle->_msg_ptr, rr->name, NS_MAXDNAME); 174 if (b < 0) 175 return (-1); 176 handle->_msg_ptr += b; 177 if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom) 178 RETERR(EMSGSIZE); 179 NS_GET16(rr->type, handle->_msg_ptr); 180 NS_GET16(rr->rr_class, handle->_msg_ptr); 181 if (section == ns_s_qd) { 182 rr->ttl = 0; 183 rr->rdlength = 0; 184 rr->rdata = NULL; 185 } else { 186 if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom) 187 RETERR(EMSGSIZE); 188 NS_GET32(rr->ttl, handle->_msg_ptr); 189 NS_GET16(rr->rdlength, handle->_msg_ptr); 190 if (handle->_msg_ptr + rr->rdlength > handle->_eom) 191 RETERR(EMSGSIZE); 192 rr->rdata = handle->_msg_ptr; 193 handle->_msg_ptr += rr->rdlength; 194 } 195 if (++handle->_rrnum > handle->_counts[(int)section]) 196 setsection(handle, (ns_sect)((int)section + 1)); 197 198 /* All done. */ 199 return (0); 200 } 201 202 /* Private. */ 203 204 static void 205 setsection(ns_msg *msg, ns_sect sect) { 206 msg->_sect = sect; 207 if (sect == ns_s_max) { 208 msg->_rrnum = -1; 209 msg->_msg_ptr = NULL; 210 } else { 211 msg->_rrnum = 0; 212 msg->_msg_ptr = msg->_sections[(int)sect]; 213 } 214 } 215