1 /* 2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 3 * Copyright (c) 1996,1999 by Internet Software Consortium. 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 15 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #include "port_before.h" 19 20 #include <sys/types.h> 21 22 #include <netinet/in.h> 23 #include <arpa/nameser.h> 24 25 #include <errno.h> 26 #include <resolv.h> 27 #include <string.h> 28 29 #include "port_after.h" 30 31 /* Forward. */ 32 33 static void setsection(ns_msg *msg, ns_sect sect); 34 35 /* Macros. */ 36 37 #if !defined(SOLARIS2) || defined(__COVERITY__) 38 #define RETERR(err) do { errno = (err); return (-1); } while (0) 39 #else 40 #define RETERR(err) \ 41 do { errno = (err); if (errno == errno) return (-1); } while (0) 42 #endif 43 44 #define PARSE_FMT_PRESO 0 /* Parse using presentation-format names */ 45 #define PARSE_FMT_WIRE 1 /* Parse using network-format names */ 46 47 /* Public. */ 48 49 /* These need to be in the same order as the nres.h:ns_flag enum. */ 50 struct _ns_flagdata _ns_flagdata[16] = { 51 { 0x8000, 15 }, /*%< qr. */ 52 { 0x7800, 11 }, /*%< opcode. */ 53 { 0x0400, 10 }, /*%< aa. */ 54 { 0x0200, 9 }, /*%< tc. */ 55 { 0x0100, 8 }, /*%< rd. */ 56 { 0x0080, 7 }, /*%< ra. */ 57 { 0x0040, 6 }, /*%< z. */ 58 { 0x0020, 5 }, /*%< ad. */ 59 { 0x0010, 4 }, /*%< cd. */ 60 { 0x000f, 0 }, /*%< rcode. */ 61 { 0x0000, 0 }, /*%< expansion (1/6). */ 62 { 0x0000, 0 }, /*%< expansion (2/6). */ 63 { 0x0000, 0 }, /*%< expansion (3/6). */ 64 { 0x0000, 0 }, /*%< expansion (4/6). */ 65 { 0x0000, 0 }, /*%< expansion (5/6). */ 66 { 0x0000, 0 }, /*%< expansion (6/6). */ 67 }; 68 69 int ns_msg_getflag(ns_msg handle, int flag) { 70 return(((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift); 71 } 72 73 int 74 ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) { 75 const u_char *optr = ptr; 76 77 for ((void)NULL; count > 0; count--) { 78 int b, rdlength; 79 80 b = dn_skipname(ptr, eom); 81 if (b < 0) 82 RETERR(EMSGSIZE); 83 ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/; 84 if (section != ns_s_qd) { 85 if (ptr + NS_INT32SZ + NS_INT16SZ > eom) 86 RETERR(EMSGSIZE); 87 ptr += NS_INT32SZ/*TTL*/; 88 NS_GET16(rdlength, ptr); 89 ptr += rdlength/*RData*/; 90 } 91 } 92 if (ptr > eom) 93 RETERR(EMSGSIZE); 94 return (ptr - optr); 95 } 96 97 int 98 ns_initparse(const u_char *msg, int msglen, ns_msg *handle) { 99 const u_char *eom = msg + msglen; 100 int i; 101 102 handle->_msg = msg; 103 handle->_eom = eom; 104 if (msg + NS_INT16SZ > eom) 105 RETERR(EMSGSIZE); 106 NS_GET16(handle->_id, msg); 107 if (msg + NS_INT16SZ > eom) 108 RETERR(EMSGSIZE); 109 NS_GET16(handle->_flags, msg); 110 for (i = 0; i < ns_s_max; i++) { 111 if (msg + NS_INT16SZ > eom) 112 RETERR(EMSGSIZE); 113 NS_GET16(handle->_counts[i], msg); 114 } 115 for (i = 0; i < ns_s_max; i++) 116 if (handle->_counts[i] == 0) 117 handle->_sections[i] = NULL; 118 else { 119 int b = ns_skiprr(msg, eom, (ns_sect)i, 120 handle->_counts[i]); 121 122 if (b < 0) 123 return (-1); 124 handle->_sections[i] = msg; 125 msg += b; 126 } 127 if (msg != eom) 128 RETERR(EMSGSIZE); 129 setsection(handle, ns_s_max); 130 return (0); 131 } 132 133 int 134 ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) { 135 int b; 136 int tmp; 137 138 /* Make section right. */ 139 tmp = section; 140 if (tmp < 0 || section >= ns_s_max) 141 RETERR(ENODEV); 142 if (section != handle->_sect) 143 setsection(handle, section); 144 145 /* Make rrnum right. */ 146 if (rrnum == -1) 147 rrnum = handle->_rrnum; 148 if (rrnum < 0 || rrnum >= handle->_counts[(int)section]) 149 RETERR(ENODEV); 150 if (rrnum < handle->_rrnum) 151 setsection(handle, section); 152 if (rrnum > handle->_rrnum) { 153 b = ns_skiprr(handle->_msg_ptr, handle->_eom, section, 154 rrnum - handle->_rrnum); 155 156 if (b < 0) 157 return (-1); 158 handle->_msg_ptr += b; 159 handle->_rrnum = rrnum; 160 } 161 162 /* Do the parse. */ 163 b = dn_expand(handle->_msg, handle->_eom, 164 handle->_msg_ptr, rr->name, NS_MAXDNAME); 165 if (b < 0) 166 return (-1); 167 handle->_msg_ptr += b; 168 if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom) 169 RETERR(EMSGSIZE); 170 NS_GET16(rr->type, handle->_msg_ptr); 171 NS_GET16(rr->rr_class, handle->_msg_ptr); 172 if (section == ns_s_qd) { 173 rr->ttl = 0; 174 rr->rdlength = 0; 175 rr->rdata = NULL; 176 } else { 177 if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom) 178 RETERR(EMSGSIZE); 179 NS_GET32(rr->ttl, handle->_msg_ptr); 180 NS_GET16(rr->rdlength, handle->_msg_ptr); 181 if (handle->_msg_ptr + rr->rdlength > handle->_eom) 182 RETERR(EMSGSIZE); 183 rr->rdata = handle->_msg_ptr; 184 handle->_msg_ptr += rr->rdlength; 185 } 186 if (++handle->_rrnum > handle->_counts[(int)section]) 187 setsection(handle, (ns_sect)((int)section + 1)); 188 189 /* All done. */ 190 return (0); 191 } 192 193 /* 194 * This is identical to the above but uses network-format (uncompressed) names. 195 */ 196 int 197 ns_parserr2(ns_msg *handle, ns_sect section, int rrnum, ns_rr2 *rr) { 198 int b; 199 int tmp; 200 201 /* Make section right. */ 202 if ((tmp = section) < 0 || section >= ns_s_max) 203 RETERR(ENODEV); 204 if (section != handle->_sect) 205 setsection(handle, section); 206 207 /* Make rrnum right. */ 208 if (rrnum == -1) 209 rrnum = handle->_rrnum; 210 if (rrnum < 0 || rrnum >= handle->_counts[(int)section]) 211 RETERR(ENODEV); 212 if (rrnum < handle->_rrnum) 213 setsection(handle, section); 214 if (rrnum > handle->_rrnum) { 215 b = ns_skiprr(handle->_msg_ptr, handle->_eom, section, 216 rrnum - handle->_rrnum); 217 218 if (b < 0) 219 return (-1); 220 handle->_msg_ptr += b; 221 handle->_rrnum = rrnum; 222 } 223 224 /* Do the parse. */ 225 b = ns_name_unpack2(handle->_msg, handle->_eom, handle->_msg_ptr, 226 rr->nname, NS_MAXNNAME, &rr->nnamel); 227 if (b < 0) 228 return (-1); 229 handle->_msg_ptr += b; 230 if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom) 231 RETERR(EMSGSIZE); 232 NS_GET16(rr->type, handle->_msg_ptr); 233 NS_GET16(rr->rr_class, handle->_msg_ptr); 234 if (section == ns_s_qd) { 235 rr->ttl = 0; 236 rr->rdlength = 0; 237 rr->rdata = NULL; 238 } else { 239 if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom) 240 RETERR(EMSGSIZE); 241 NS_GET32(rr->ttl, handle->_msg_ptr); 242 NS_GET16(rr->rdlength, handle->_msg_ptr); 243 if (handle->_msg_ptr + rr->rdlength > handle->_eom) 244 RETERR(EMSGSIZE); 245 rr->rdata = handle->_msg_ptr; 246 handle->_msg_ptr += rr->rdlength; 247 } 248 if (++handle->_rrnum > handle->_counts[(int)section]) 249 setsection(handle, (ns_sect)((int)section + 1)); 250 251 /* All done. */ 252 return (0); 253 } 254 255 /* Private. */ 256 257 static void 258 setsection(ns_msg *msg, ns_sect sect) { 259 msg->_sect = sect; 260 if (sect == ns_s_max) { 261 msg->_rrnum = -1; 262 msg->_msg_ptr = NULL; 263 } else { 264 msg->_rrnum = 0; 265 msg->_msg_ptr = msg->_sections[(int)sect]; 266 } 267 } 268 269 /*! \file */ 270