ns_parse.c revision 1.6.8.1
1 /* $NetBSD: ns_parse.c,v 1.6.8.1 2009/05/13 19:18:25 jym Exp $ */ 2 3 /* 4 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 5 * Copyright (c) 1996,1999 by Internet Software Consortium. 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 17 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 #include <sys/cdefs.h> 21 #ifndef lint 22 #ifdef notdef 23 static const char rcsid[] = "Id: ns_parse.c,v 1.10 2009/01/23 19:59:16 each Exp"; 24 #else 25 __RCSID("$NetBSD: ns_parse.c,v 1.6.8.1 2009/05/13 19:18:25 jym Exp $"); 26 #endif 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 #if !defined(SOLARIS2) || defined(__COVERITY__) 51 #define RETERR(err) do { errno = (err); return (-1); } while (/*NOTREACHED*//*CONSTCOND*/0) 52 #else 53 #define RETERR(err) \ 54 do { errno = (err); if (errno == errno) return (-1); } while (0) 55 #endif 56 57 #define PARSE_FMT_PRESO 0 /* Parse using presentation-format names */ 58 #define PARSE_FMT_WIRE 1 /* Parse using network-format names */ 59 60 /* Public. */ 61 62 /* These need to be in the same order as the nres.h:ns_flag enum. */ 63 struct _ns_flagdata _ns_flagdata[16] = { 64 { 0x8000, 15 }, /*%< qr. */ 65 { 0x7800, 11 }, /*%< opcode. */ 66 { 0x0400, 10 }, /*%< aa. */ 67 { 0x0200, 9 }, /*%< tc. */ 68 { 0x0100, 8 }, /*%< rd. */ 69 { 0x0080, 7 }, /*%< ra. */ 70 { 0x0040, 6 }, /*%< z. */ 71 { 0x0020, 5 }, /*%< ad. */ 72 { 0x0010, 4 }, /*%< cd. */ 73 { 0x000f, 0 }, /*%< rcode. */ 74 { 0x0000, 0 }, /*%< expansion (1/6). */ 75 { 0x0000, 0 }, /*%< expansion (2/6). */ 76 { 0x0000, 0 }, /*%< expansion (3/6). */ 77 { 0x0000, 0 }, /*%< expansion (4/6). */ 78 { 0x0000, 0 }, /*%< expansion (5/6). */ 79 { 0x0000, 0 }, /*%< expansion (6/6). */ 80 }; 81 82 int ns_msg_getflag(ns_msg handle, int flag) { 83 return((u_int32_t)((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift); 84 } 85 86 int 87 ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) { 88 const u_char *optr = ptr; 89 90 for (; count > 0; count--) { 91 int b, rdlength; 92 93 b = dn_skipname(ptr, eom); 94 if (b < 0) 95 RETERR(EMSGSIZE); 96 ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/; 97 if (section != ns_s_qd) { 98 if (ptr + NS_INT32SZ + NS_INT16SZ > eom) 99 RETERR(EMSGSIZE); 100 ptr += NS_INT32SZ/*TTL*/; 101 NS_GET16(rdlength, ptr); 102 ptr += rdlength/*RData*/; 103 } 104 } 105 if (ptr > eom) 106 RETERR(EMSGSIZE); 107 return (ptr - optr); 108 } 109 110 int 111 ns_initparse(const u_char *msg, int msglen, ns_msg *handle) { 112 const u_char *eom = msg + msglen; 113 int i; 114 115 handle->_msg = msg; 116 handle->_eom = eom; 117 if (msg + NS_INT16SZ > eom) 118 RETERR(EMSGSIZE); 119 NS_GET16(handle->_id, msg); 120 if (msg + NS_INT16SZ > eom) 121 RETERR(EMSGSIZE); 122 NS_GET16(handle->_flags, msg); 123 for (i = 0; i < ns_s_max; i++) { 124 if (msg + NS_INT16SZ > eom) 125 RETERR(EMSGSIZE); 126 NS_GET16(handle->_counts[i], msg); 127 } 128 for (i = 0; i < ns_s_max; i++) 129 if (handle->_counts[i] == 0) 130 handle->_sections[i] = NULL; 131 else { 132 int b = ns_skiprr(msg, eom, (ns_sect)i, 133 handle->_counts[i]); 134 135 if (b < 0) 136 return (-1); 137 handle->_sections[i] = msg; 138 msg += b; 139 } 140 if (msg != eom) 141 RETERR(EMSGSIZE); 142 setsection(handle, ns_s_max); 143 return (0); 144 } 145 146 int 147 ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) { 148 int b; 149 int tmp; 150 151 /* Make section right. */ 152 tmp = section; 153 if (tmp < 0 || section >= ns_s_max) 154 RETERR(ENODEV); 155 if (section != handle->_sect) 156 setsection(handle, section); 157 158 /* Make rrnum right. */ 159 if (rrnum == -1) 160 rrnum = handle->_rrnum; 161 if (rrnum < 0 || rrnum >= handle->_counts[(int)section]) 162 RETERR(ENODEV); 163 if (rrnum < handle->_rrnum) 164 setsection(handle, section); 165 if (rrnum > handle->_rrnum) { 166 b = ns_skiprr(handle->_msg_ptr, handle->_eom, section, 167 rrnum - handle->_rrnum); 168 169 if (b < 0) 170 return (-1); 171 handle->_msg_ptr += b; 172 handle->_rrnum = rrnum; 173 } 174 175 /* Do the parse. */ 176 b = dn_expand(handle->_msg, handle->_eom, 177 handle->_msg_ptr, rr->name, NS_MAXDNAME); 178 if (b < 0) 179 return (-1); 180 handle->_msg_ptr += b; 181 if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom) 182 RETERR(EMSGSIZE); 183 NS_GET16(rr->type, handle->_msg_ptr); 184 NS_GET16(rr->rr_class, handle->_msg_ptr); 185 if (section == ns_s_qd) { 186 rr->ttl = 0; 187 rr->rdlength = 0; 188 rr->rdata = NULL; 189 } else { 190 if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom) 191 RETERR(EMSGSIZE); 192 NS_GET32(rr->ttl, handle->_msg_ptr); 193 NS_GET16(rr->rdlength, handle->_msg_ptr); 194 if (handle->_msg_ptr + rr->rdlength > handle->_eom) 195 RETERR(EMSGSIZE); 196 rr->rdata = handle->_msg_ptr; 197 handle->_msg_ptr += rr->rdlength; 198 } 199 if (++handle->_rrnum > handle->_counts[(int)section]) 200 setsection(handle, (ns_sect)((int)section + 1)); 201 202 /* All done. */ 203 return (0); 204 } 205 206 /* 207 * This is identical to the above but uses network-format (uncompressed) names. 208 */ 209 int 210 ns_parserr2(ns_msg *handle, ns_sect section, int rrnum, ns_rr2 *rr) { 211 int b; 212 int tmp; 213 214 /* Make section right. */ 215 tmp = section; 216 if (tmp < 0 || section >= ns_s_max) 217 RETERR(ENODEV); 218 if (section != handle->_sect) 219 setsection(handle, section); 220 221 /* Make rrnum right. */ 222 if (rrnum == -1) 223 rrnum = handle->_rrnum; 224 if (rrnum < 0 || rrnum >= handle->_counts[(int)section]) 225 RETERR(ENODEV); 226 if (rrnum < handle->_rrnum) 227 setsection(handle, section); 228 if (rrnum > handle->_rrnum) { 229 b = ns_skiprr(handle->_msg_ptr, handle->_eom, section, 230 rrnum - handle->_rrnum); 231 232 if (b < 0) 233 return (-1); 234 handle->_msg_ptr += b; 235 handle->_rrnum = rrnum; 236 } 237 238 /* Do the parse. */ 239 b = ns_name_unpack2(handle->_msg, handle->_eom, handle->_msg_ptr, 240 rr->nname, NS_MAXNNAME, &rr->nnamel); 241 if (b < 0) 242 return (-1); 243 handle->_msg_ptr += b; 244 if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom) 245 RETERR(EMSGSIZE); 246 NS_GET16(rr->type, handle->_msg_ptr); 247 NS_GET16(rr->rr_class, handle->_msg_ptr); 248 if (section == ns_s_qd) { 249 rr->ttl = 0; 250 rr->rdlength = 0; 251 rr->rdata = NULL; 252 } else { 253 if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom) 254 RETERR(EMSGSIZE); 255 NS_GET32(rr->ttl, handle->_msg_ptr); 256 NS_GET16(rr->rdlength, handle->_msg_ptr); 257 if (handle->_msg_ptr + rr->rdlength > handle->_eom) 258 RETERR(EMSGSIZE); 259 rr->rdata = handle->_msg_ptr; 260 handle->_msg_ptr += rr->rdlength; 261 } 262 if (++handle->_rrnum > handle->_counts[(int)section]) 263 setsection(handle, (ns_sect)((int)section + 1)); 264 265 /* All done. */ 266 return (0); 267 } 268 269 /* Private. */ 270 271 static void 272 setsection(ns_msg *msg, ns_sect sect) { 273 msg->_sect = sect; 274 if (sect == ns_s_max) { 275 msg->_rrnum = -1; 276 msg->_msg_ptr = NULL; 277 } else { 278 msg->_rrnum = 0; 279 msg->_msg_ptr = msg->_sections[(int)sect]; 280 } 281 } 282 283 /*! \file */ 284
Indexes created Tue Sep 30 20:09:53 GMT 2025