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<h1>dns.c</h1><a href="dns_8c.html">Go to the documentation of this file.</a><pre class="fragment"><div>00001 <span class="comment">/* libspf - Sender Policy Framework library</span> |
| 10 |
00002 <span class="comment">*</span> |
| 11 |
00003 <span class="comment">* ANSI C implementation of spf-draft-200405.txt</span> |
| 12 |
00004 <span class="comment">*</span> |
| 13 |
00005 <span class="comment">* Author: James Couzens <jcouzens@codeshare.ca></span> |
| 14 |
00006 <span class="comment">* Author: Sean Comeau <scomeau@obscurity.org></span> |
| 15 |
00007 <span class="comment">*</span> |
| 16 |
00008 <span class="comment">* File: dns.c</span> |
| 17 |
00009 <span class="comment">* Desc: DNS related functions</span> |
| 18 |
00010 <span class="comment">*</span> |
| 19 |
00011 <span class="comment">* License:</span> |
| 20 |
00012 <span class="comment">*</span> |
| 21 |
00013 <span class="comment">* The libspf Software License, Version 1.0</span> |
| 22 |
00014 <span class="comment">*</span> |
| 23 |
00015 <span class="comment">* Copyright (c) 2004 James Couzens & Sean Comeau All rights</span> |
| 24 |
00016 <span class="comment">* reserved.</span> |
| 25 |
00017 <span class="comment">*</span> |
| 26 |
00018 <span class="comment">* Redistribution and use in source and binary forms, with or without</span> |
| 27 |
00019 <span class="comment">* modification, are permitted provided that the following conditions</span> |
| 28 |
00020 <span class="comment">* are met:</span> |
| 29 |
00021 <span class="comment">*</span> |
| 30 |
00022 <span class="comment">* 1. Redistributions of source code must retain the above copyright</span> |
| 31 |
00023 <span class="comment">* notice, this list of conditions and the following disclaimer.</span> |
| 32 |
00024 <span class="comment">*</span> |
| 33 |
00025 <span class="comment">* 2. Redistributions in binary form must reproduce the above copyright</span> |
| 34 |
00026 <span class="comment">* notice, this list of conditions and the following disclaimer in</span> |
| 35 |
00027 <span class="comment">* the documentation and/or other materials provided with the</span> |
| 36 |
00028 <span class="comment">* distribution.</span> |
| 37 |
00029 <span class="comment">*</span> |
| 38 |
00030 <span class="comment">* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED</span> |
| 39 |
00031 <span class="comment">* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES</span> |
| 40 |
00032 <span class="comment">* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE</span> |
| 41 |
00033 <span class="comment">* DISCLAIMED. IN NO EVENT SHALL THE AUTHORS MAKING USE OF THIS LICESEN</span> |
| 42 |
00034 <span class="comment">* OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,</span> |
| 43 |
00035 <span class="comment">* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT</span> |
| 44 |
00036 <span class="comment">* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF</span> |
| 45 |
00037 <span class="comment">* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND</span> |
| 46 |
00038 <span class="comment">* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,</span> |
| 47 |
00039 <span class="comment">* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT</span> |
| 48 |
00040 <span class="comment">* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF</span> |
| 49 |
00041 <span class="comment">* SUCH DAMAGE.</span> |
| 50 |
00042 <span class="comment">*</span> |
| 51 |
00043 <span class="comment">*/</span> |
| 52 |
00044 |
| 53 |
00045 |
| 54 |
00046 <span class="preprocessor">#ifdef _WITH_PTHREADS</span> |
| 55 |
00047 <span class="preprocessor"></span><span class="preprocessor">#include <pthread.h></span> <span class="comment">/* pthread_mutex_t */</span> |
| 56 |
00048 <span class="preprocessor"> #ifdef HAVE_GETHOSTBYNAME_R</span> |
| 57 |
00049 <span class="preprocessor"></span><span class="preprocessor">#include <errno.h></span> <span class="comment">/* errno */</span> |
| 58 |
00050 <span class="preprocessor"> #endif </span><span class="comment">/* HAVE_GETHOSTBYNAME_R */</span> |
| 59 |
00051 <span class="preprocessor">#endif </span><span class="comment">/* _WITH_PTHREADS */</span> |
| 60 |
00052 |
| 61 |
00053 <span class="preprocessor">#include "<a class="code" href="spf_8h.html">spf.h</a>"</span> <span class="comment">/* SPF */</span> |
| 62 |
00054 <span class="preprocessor">#include "<a class="code" href="util_8h.html">util.h</a>"</span> <span class="comment">/* Utility functions */</span> |
| 63 |
00055 <span class="preprocessor">#include "<a class="code" href="dns_8h.html">dns.h</a>"</span> <span class="comment">/* our header */</span> |
| 64 |
00056 <span class="preprocessor">#include "../../config.h"</span> <span class="comment">/* autoconf */</span> |
| 65 |
00057 |
| 66 |
00058 <span class="preprocessor">#ifdef _WITH_PTHREADS</span> |
| 67 |
00059 <span class="preprocessor"></span> |
| 68 |
00060 <span class="comment">/* mutex for gethostbyname wrapper */</span> |
| 69 |
00061 pthread_mutex_t <a class="code" href="dns_8c.html#a0">dns_mutex</a> = PTHREAD_MUTEX_INITIALIZER; |
| 70 |
00062 |
| 71 |
00063 <span class="preprocessor"> #ifdef HAVE_GETHOSTBYNAME_R</span> |
| 72 |
00064 <span class="preprocessor"></span> |
| 73 |
00065 <span class="comment">/* used by gethostbyname_r */</span> |
| 74 |
00066 <span class="keyword">extern</span> <span class="keywordtype">int</span> <a class="code" href="util_8c.html#a1">errno</a>; |
| 75 |
00067 |
| 76 |
00068 <span class="preprocessor"> #endif </span><span class="comment">/* HAVE_GETHOSTBYNAME_R */</span> |
| 77 |
00069 <span class="preprocessor">#else</span> |
| 78 |
00070 <span class="preprocessor"></span> |
| 79 |
00071 <span class="comment">/* mutex for gethostbyname dummy wrapper */</span> |
| 80 |
<a name="l00072"></a><a class="code" href="dns_8c.html#a0">00072</a> <span class="keywordtype">void</span> *<a class="code" href="dns_8c.html#a0">dns_mutex</a>; |
| 81 |
00073 |
| 82 |
00074 <span class="preprocessor">#endif </span><span class="comment">/* _WITH_PTHREADS */</span> |
| 83 |
00075 |
| 84 |
00076 |
| 85 |
00202 <span class="comment">/* DNS_query</span> |
| 86 |
00203 <span class="comment">*</span> |
| 87 |
00204 <span class="comment">* Author: James Couzens <jcouzens@codeshare.ca>\n</span> |
| 88 |
00205 <span class="comment">* Author: Travis Anderson <tanderson@codeshare.ca>\n</span> |
| 89 |
00206 <span class="comment">*</span> |
| 90 |
00207 <span class="comment">* Date: 12/10/03</span> |
| 91 |
00208 <span class="comment">* Date: 02/20/04 - Added cache by Travis Anderson <tanderson@codeshare.ca></span> |
| 92 |
00209 <span class="comment">*</span> |
| 93 |
00210 <span class="comment">* Desc:</span> |
| 94 |
00211 <span class="comment">* Executes a DNS query of type T_TYPE and then calls the</span> |
| 95 |
00212 <span class="comment">* appropriate answer parsing function based on that type. Returns</span> |
| 96 |
00213 <span class="comment">* a pointer to allocated memory (a string of space delimited</span> |
| 97 |
00214 <span class="comment">* records). Upon failure returns NULL.</span> |
| 98 |
00215 <span class="comment">*</span> |
| 99 |
00216 <span class="comment">*/</span> |
| 100 |
<a name="l00217"></a><a class="code" href="dns_8h.html#a8">00217</a> <span class="keywordtype">char</span> *<a class="code" href="dns_8h.html#a8">DNS_query</a>(<a class="code" href="structpeer__info__s.html">peer_info_t</a> *p, <span class="keyword">const</span> <span class="keywordtype">char</span> *s, <span class="keyword">const</span> <span class="keywordtype">int</span> T_TYPE, |
| 101 |
00218 <span class="keyword">const</span> <span class="keywordtype">char</span> *mta) |
| 102 |
00219 { |
| 103 |
00220 HEADER *hdr; <span class="comment">/* pointer to the header of the packet */</span> |
| 104 |
00221 |
| 105 |
00222 int8_t ancount; <span class="comment">/* number of answers */</span> |
| 106 |
00223 |
| 107 |
00224 int16_t r_len; <span class="comment">/* res_search return code & packet len */</span> |
| 108 |
00225 int16_t rc; <span class="comment">/* generic return code / length of */</span> |
| 109 |
00226 |
| 110 |
00227 <span class="keywordtype">int</span> ttl; <span class="comment">/* answer TTL */</span> |
| 111 |
00228 |
| 112 |
00229 <span class="keywordtype">char</span> buf[<a class="code" href="dns_8h.html#a2">SPF_MAXDNAME</a>]; <span class="comment">/* record extraction buffer */</span> |
| 113 |
00230 <span class="keywordtype">char</span> answer[<a class="code" href="dns_8h.html#a1">SPF_PACKETSZ</a>]; <span class="comment">/* answer buffer */</span> |
| 114 |
00231 |
| 115 |
00232 <span class="keywordtype">char</span> *rr_data = NULL; <span class="comment">/* record */</span> |
| 116 |
00233 |
| 117 |
00234 u_char *msg_ptr; <span class="comment">/* pointer to beginning of the message */</span> |
| 118 |
00235 u_char *eom_ptr; <span class="comment">/* pointer to the end of the message */</span> |
| 119 |
00236 u_char *rd_ptr; <span class="comment">/* pointer to uncompressed message */</span> |
| 120 |
00237 |
| 121 |
00238 |
| 122 |
00239 <span class="keywordflow">if</span> (s == NULL) |
| 123 |
00240 { |
| 124 |
00241 <a class="code" href="util_8h.html#a13">xepprintf</a>(<span class="stringliteral">"Passed a NULL char. Aborting.\n"</span>); |
| 125 |
00242 <span class="keywordflow">return</span>(NULL); |
| 126 |
00243 } |
| 127 |
00244 |
| 128 |
00245 <a class="code" href="util_8h.html#a9">xprintf</a>(<span class="stringliteral">"Called with (%s) and type: %i\n"</span>, s, T_TYPE); |
| 129 |
00246 |
| 130 |
00247 r_len = res_search(s, C_IN, T_TYPE, (u_char *)answer, <a class="code" href="dns_8h.html#a1">SPF_PACKETSZ</a>); |
| 131 |
00248 |
| 132 |
00249 <span class="keywordflow">if</span> (r_len <= 0) |
| 133 |
00250 { |
| 134 |
00251 <span class="keywordflow">switch</span> (<a class="code" href="dns_8h.html#a6">h_errno</a>) |
| 135 |
00252 { |
| 136 |
00253 <span class="keywordflow">case</span> HOST_NOT_FOUND: |
| 137 |
00254 snprintf(p-><a class="code" href="structpeer__info__s.html#o24">error</a>, <a class="code" href="spf_8h.html#a16">SPF_MAX_ERROR</a>, <span class="stringliteral">"%s\n"</span>, hstrerror(<a class="code" href="dns_8h.html#a6">h_errno</a>)); |
| 138 |
00255 <a class="code" href="util_8h.html#a47">UTIL_assoc_prefix</a>(p, <a class="code" href="spf_8h.html#a88a52">SPF_NONE</a>, NULL); |
| 139 |
00256 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"%s\n"</span>, p-><a class="code" href="structpeer__info__s.html#o24">error</a>); |
| 140 |
00257 |
| 141 |
00258 <span class="keywordflow">return</span>(NULL); |
| 142 |
00259 |
| 143 |
00260 <span class="keywordflow">case</span> TRY_AGAIN: |
| 144 |
00261 snprintf(p-><a class="code" href="structpeer__info__s.html#o24">error</a>, <a class="code" href="spf_8h.html#a16">SPF_MAX_ERROR</a>, <span class="stringliteral">"%s\n"</span>, hstrerror(<a class="code" href="dns_8h.html#a6">h_errno</a>)); |
| 145 |
00262 <a class="code" href="util_8h.html#a47">UTIL_assoc_prefix</a>(p, <a class="code" href="spf_8h.html#a88a52">SPF_NONE</a>, NULL); |
| 146 |
00263 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"%s\n"</span>, p-><a class="code" href="structpeer__info__s.html#o24">error</a>); |
| 147 |
00264 |
| 148 |
00265 <span class="keywordflow">return</span>(NULL); |
| 149 |
00266 |
| 150 |
00267 <span class="keywordflow">case</span> NO_RECOVERY: |
| 151 |
00268 snprintf(p-><a class="code" href="structpeer__info__s.html#o24">error</a>, <a class="code" href="spf_8h.html#a16">SPF_MAX_ERROR</a>, <span class="stringliteral">"%s\n"</span>, hstrerror(<a class="code" href="dns_8h.html#a6">h_errno</a>)); |
| 152 |
00269 <a class="code" href="util_8h.html#a47">UTIL_assoc_prefix</a>(p, <a class="code" href="spf_8h.html#a88a55">SPF_ERROR</a>, NULL); |
| 153 |
00270 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"%s\n"</span>, p-><a class="code" href="structpeer__info__s.html#o24">error</a>); |
| 154 |
00271 |
| 155 |
00272 <span class="keywordflow">return</span>(NULL); |
| 156 |
00273 |
| 157 |
00274 <span class="keywordflow">case</span> NO_DATA: |
| 158 |
00275 snprintf(p-><a class="code" href="structpeer__info__s.html#o24">error</a>, <a class="code" href="spf_8h.html#a16">SPF_MAX_ERROR</a>, <span class="stringliteral">"%s\n"</span>, hstrerror(<a class="code" href="dns_8h.html#a6">h_errno</a>)); |
| 159 |
00276 <a class="code" href="util_8h.html#a47">UTIL_assoc_prefix</a>(p, <a class="code" href="spf_8h.html#a88a52">SPF_NONE</a>, NULL); |
| 160 |
00277 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"%s\n"</span>, p-><a class="code" href="structpeer__info__s.html#o24">error</a>); |
| 161 |
00278 |
| 162 |
00279 <span class="keywordflow">return</span>(NULL); |
| 163 |
00280 |
| 164 |
00281 <span class="keywordflow">default</span>: |
| 165 |
00282 snprintf(p-><a class="code" href="structpeer__info__s.html#o24">error</a>, <a class="code" href="spf_8h.html#a16">SPF_MAX_ERROR</a>, <span class="stringliteral">"%s\n"</span>, hstrerror(<a class="code" href="dns_8h.html#a6">h_errno</a>)); |
| 166 |
00283 <a class="code" href="util_8h.html#a47">UTIL_assoc_prefix</a>(p, <a class="code" href="spf_8h.html#a88a55">SPF_ERROR</a>, NULL); |
| 167 |
00284 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"%s\n"</span>, p-><a class="code" href="structpeer__info__s.html#o24">error</a>); |
| 168 |
00285 |
| 169 |
00286 <span class="keywordflow">return</span>(NULL); |
| 170 |
00287 } <span class="comment">/* switch */</span> |
| 171 |
00288 } |
| 172 |
00289 |
| 173 |
00290 hdr = (HEADER *)&answer; |
| 174 |
00291 ancount = ntohs(hdr->ancount); |
| 175 |
00292 |
| 176 |
00293 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Received packet size of %i bytes which contains %i answers.\n"</span>, |
| 177 |
00294 r_len, ancount); |
| 178 |
00295 |
| 179 |
00296 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"ANSWERS: %i\n"</span>, ancount); |
| 180 |
00297 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"QUESTIONS: %i\n"</span>, ntohs(hdr->qdcount)); |
| 181 |
00298 |
| 182 |
00299 <span class="keywordflow">if</span> (ancount > 0) |
| 183 |
00300 { |
| 184 |
00301 msg_ptr = (u_char *)&answer; <span class="comment">/* point to start of message */</span> |
| 185 |
00302 eom_ptr = (u_char *)&answer + r_len; <span class="comment">/* point to end of message */</span> |
| 186 |
00303 rd_ptr = (u_char *)&answer + HFIXEDSZ; <span class="comment">/* point to start of RDATA */</span> |
| 187 |
00304 |
| 188 |
00305 <span class="keywordflow">if</span> ((rc = dn_skipname(rd_ptr, eom_ptr)) < 0) |
| 189 |
00306 { |
| 190 |
00307 <a class="code" href="util_8h.html#a13">xepprintf</a>(<span class="stringliteral">"Error obtaining QUESTION!\n"</span>); |
| 191 |
00308 |
| 192 |
00309 <span class="keywordflow">return</span>(NULL); |
| 193 |
00310 } |
| 194 |
00311 |
| 195 |
00312 rd_ptr += rc + QFIXEDSZ; <span class="comment">/* jump to start of ANSWER */</span> |
| 196 |
00313 |
| 197 |
00314 <span class="keywordflow">switch</span> (T_TYPE) |
| 198 |
00315 { |
| 199 |
00316 <span class="comment">/*</span> |
| 200 |
00317 <span class="comment"> * T_A: A 'a' or address record used to associate an IP address with any</span> |
| 201 |
00318 <span class="comment"> * given hostname.</span> |
| 202 |
00319 <span class="comment"> */</span> |
| 203 |
00320 <span class="keywordflow">case</span> T_A: |
| 204 |
00321 <span class="keywordflow">return</span>((<span class="keywordtype">char</span> *)<a class="code" href="spf_8h.html#a87a50">SPF_TRUE</a>); |
| 205 |
00322 |
| 206 |
00323 <span class="comment">/*</span> |
| 207 |
00324 <span class="comment"> * T_TXT: A 'txt' or TEXT record which is what is currently used to store</span> |
| 208 |
00325 <span class="comment"> * the SPF records within DNS. Its unfortunate that this had to be done</span> |
| 209 |
00326 <span class="comment"> * because you'll discover that I had to make concessions to deal with</span> |
| 210 |
00327 <span class="comment"> * the fact that many people publish more than just SPF records using</span> |
| 211 |
00328 <span class="comment"> * the T_TXT record type, especially considering it was seeing use long</span> |
| 212 |
00329 <span class="comment"> * before SPF ever came on the scene. Hopefully this will change in the</span> |
| 213 |
00330 <span class="comment"> * near future.</span> |
| 214 |
00331 <span class="comment"> */</span> |
| 215 |
00332 <span class="keywordflow">case</span> T_TXT: |
| 216 |
00333 <span class="keywordflow">if</span> ((rr_data = <a class="code" href="dns_8h.html#a9">DNS_txt_answer</a>(ancount, (u_char *)msg_ptr, (u_char *)eom_ptr, |
| 217 |
00334 (u_char *)rd_ptr, buf, &ttl)) == NULL) |
| 218 |
00335 { |
| 219 |
00336 <span class="keywordflow">return</span>(NULL); |
| 220 |
00337 } |
| 221 |
00338 <span class="keywordflow">break</span>; |
| 222 |
00339 |
| 223 |
00340 <span class="comment">/*</span> |
| 224 |
00341 <span class="comment"> * T_MX: A 'mx' or Mail Exchanger (Server) record identifies an authorative</span> |
| 225 |
00342 <span class="comment"> * mail server (or in multiples server(s)) which may be used to deliver</span> |
| 226 |
00343 <span class="comment"> * e-mail to a given domain.</span> |
| 227 |
00344 <span class="comment"> */</span> |
| 228 |
00345 <span class="keywordflow">case</span> T_MX: |
| 229 |
00346 <span class="keywordflow">if</span> ((rr_data = <a class="code" href="dns_8h.html#a10">DNS_mx_answer</a>(ancount, (u_char *)msg_ptr, (u_char *)eom_ptr, |
| 230 |
00347 (u_char *)rd_ptr, buf, &ttl)) == NULL) |
| 231 |
00348 { |
| 232 |
00349 <span class="keywordflow">return</span>(NULL); |
| 233 |
00350 } |
| 234 |
00351 <span class="keywordflow">break</span>; |
| 235 |
00352 |
| 236 |
00353 <span class="comment">/*</span> |
| 237 |
00354 <span class="comment"> * T_PTR: A 'ptr' DNS record contains the reverse address for a</span> |
| 238 |
00355 <span class="comment"> * given hostname in the format x.x.x.x-in-addr.arpa in the</span> |
| 239 |
00356 <span class="comment"> * case of IPv4.</span> |
| 240 |
00357 <span class="comment"> */</span> |
| 241 |
00358 <span class="keywordflow">case</span> T_PTR: |
| 242 |
00359 |
| 243 |
00360 <span class="comment">/*</span> |
| 244 |
00361 <span class="comment"> * Comment by: James Couzens <jcouzens@codeshare.ca></span> |
| 245 |
00362 <span class="comment"> * Date: 01/04/04</span> |
| 246 |
00363 <span class="comment"> *</span> |
| 247 |
00364 <span class="comment"> * DNS_ptr_answer doesn't allocate any memory and returns SPF_TRUE or</span> |
| 248 |
00365 <span class="comment"> * SPF_FALSE, however this function returns a char so a the boolean </span> |
| 249 |
00366 <span class="comment"> * value of SPF_TRUE/FALSE is cast to avoid writing a handler for </span> |
| 250 |
00367 <span class="comment"> * this one specific instance. I might change this in the future by</span> |
| 251 |
00368 <span class="comment"> * either altering its return type or something else but for now this</span> |
| 252 |
00369 <span class="comment"> * seems to do nicely.</span> |
| 253 |
00370 <span class="comment"> */</span> |
| 254 |
00371 <span class="keywordflow">if</span> (<a class="code" href="dns_8h.html#a11">DNS_ptr_answer</a>(p, ancount, (u_char *)msg_ptr, (u_char *)eom_ptr, |
| 255 |
00372 (u_char *)rd_ptr, buf, mta, &ttl) == <a class="code" href="spf_8h.html#a87a49">SPF_FALSE</a>) |
| 256 |
00373 { |
| 257 |
00374 <span class="keywordflow">return</span>((<span class="keywordtype">char</span> *)<a class="code" href="spf_8h.html#a87a49">SPF_FALSE</a>); |
| 258 |
00375 } |
| 259 |
00376 <span class="keywordflow">else</span> |
| 260 |
00377 { |
| 261 |
00378 <span class="keywordflow">return</span>((<span class="keywordtype">char</span> *)<a class="code" href="spf_8h.html#a87a50">SPF_TRUE</a>); |
| 262 |
00379 } |
| 263 |
00380 <span class="keywordflow">break</span>; |
| 264 |
00381 |
| 265 |
00382 <span class="comment">/*</span> |
| 266 |
00383 <span class="comment"> * T_CNAME: A 'cname' or an alias record for a DNS forward or reverse</span> |
| 267 |
00384 <span class="comment"> * record which has been assigned more than one value.</span> |
| 268 |
00385 <span class="comment"> */</span> |
| 269 |
00386 <span class="keywordflow">case</span> T_CNAME: |
| 270 |
00387 <span class="keywordflow">if</span> ((rr_data = <a class="code" href="dns_8h.html#a12">DNS_cname_answer</a>(ancount, (u_char *)msg_ptr, (u_char *)eom_ptr, |
| 271 |
00388 (u_char *)rd_ptr, buf, &ttl)) == NULL) |
| 272 |
00389 { |
| 273 |
00390 <span class="keywordflow">return</span>(NULL); |
| 274 |
00391 } |
| 275 |
00392 <span class="keywordflow">break</span>; |
| 276 |
00393 <span class="keywordflow">default</span>: |
| 277 |
00394 <span class="keywordflow">break</span>; |
| 278 |
00395 } |
| 279 |
00396 <span class="keywordflow">return</span>(rr_data); |
| 280 |
00397 } |
| 281 |
00398 |
| 282 |
00399 <span class="keywordflow">return</span>(NULL); |
| 283 |
00400 } |
| 284 |
00401 |
| 285 |
00402 |
| 286 |
00403 <span class="comment">/* DNS_txt_answer</span> |
| 287 |
00404 <span class="comment">*</span> |
| 288 |
00405 <span class="comment">* Author: James Couzens <jcouzens@codeshare.ca></span> |
| 289 |
00406 <span class="comment">*</span> |
| 290 |
00407 <span class="comment">* Date: 01/02/04</span> |
| 291 |
00408 <span class="comment">* Date: 02/23/04 - Bugfix from Albert Weichselbraun <albert@atnet.at></span> |
| 292 |
00409 <span class="comment">* Date: 02/20/04 - Added cache by Travis Anderson <tanderson@codeshare.ca></span> |
| 293 |
00410 <span class="comment">*</span> |
| 294 |
00411 <span class="comment">* Desc:</span> |
| 295 |
00412 <span class="comment">* SPF_PACKETSZ bytes are allocated and then filled with \0 chars.</span> |
| 296 |
00413 <span class="comment">* This buffer is then used in a TXT DNS query using data from the passed</span> |
| 297 |
00414 <span class="comment">* peer_info_t structure. Upon success this buffer is re-cast as a char *</span> |
| 298 |
00415 <span class="comment">* and then a pointer to this memory is returned. Upon failure a NULL</span> |
| 299 |
00416 <span class="comment">* pointer is returned.</span> |
| 300 |
00417 <span class="comment">*</span> |
| 301 |
00418 <span class="comment">*/</span> |
| 302 |
<a name="l00419"></a><a class="code" href="dns_8h.html#a9">00419</a> <span class="keywordtype">char</span> *<a class="code" href="dns_8h.html#a9">DNS_txt_answer</a>(int16_t ancount, <span class="keyword">const</span> u_char *msg_ptr, |
| 303 |
00420 <span class="keyword">const</span> u_char *eom_ptr, u_char *rd_ptr, <span class="keywordtype">char</span> *buf, <span class="keywordtype">int</span> *ttl) |
| 304 |
00421 { |
| 305 |
00422 int16_t i; <span class="comment">/* utility */</span> |
| 306 |
00423 int16_t j; <span class="comment">/* utility */</span> |
| 307 |
00424 int16_t rc; <span class="comment">/* generic return code / length of */</span> |
| 308 |
00425 int16_t rd_type; <span class="comment">/* answer type */</span> |
| 309 |
00426 int16_t rd_len; <span class="comment">/* res_search return code & packet len */</span> |
| 310 |
00427 |
| 311 |
00428 int32_t rd_ttl; <span class="comment">/* TTL */</span> |
| 312 |
00429 |
| 313 |
00430 <span class="keywordtype">char</span> *rr_data = NULL; <span class="comment">/* data pointer */</span> |
| 314 |
00431 <span class="keywordtype">char</span> *r_buf = NULL; <span class="comment">/* return buffer */</span> |
| 315 |
00432 <span class="keywordtype">char</span> *pos = NULL; <span class="comment">/* utility pointer */</span> |
| 316 |
00433 |
| 317 |
00434 |
| 318 |
00435 <span class="keywordflow">if</span> ((msg_ptr == NULL) || (eom_ptr == NULL) || |
| 319 |
00436 (rd_ptr == NULL) || (buf == NULL)) |
| 320 |
00437 { |
| 321 |
00438 <a class="code" href="util_8h.html#a13">xepprintf</a>(<span class="stringliteral">"Called with NULL pointers\n"</span>); |
| 322 |
00439 <span class="keywordflow">return</span>(NULL); |
| 323 |
00440 } |
| 324 |
00441 |
| 325 |
00442 <a class="code" href="util_8h.html#a11">xpprintf</a>(<span class="stringliteral">"entering function\n"</span>); |
| 326 |
00443 |
| 327 |
00444 i = 0; |
| 328 |
00445 j = ancount; |
| 329 |
00446 <span class="keywordflow">while</span> ((ancount > 0) && (rd_ptr < eom_ptr)) |
| 330 |
00447 { |
| 331 |
00448 <span class="keywordflow">if</span> ((rc = dn_expand(msg_ptr, eom_ptr, rd_ptr, buf, <a class="code" href="dns_8h.html#a3">SPF_MAXCDNAME</a>)) < 0) |
| 332 |
00449 { |
| 333 |
00450 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Unable to expand T_TXT response packet!; Reason: %s\n"</span>, |
| 334 |
00451 hstrerror(<a class="code" href="dns_8h.html#a6">h_errno</a>)); |
| 335 |
00452 |
| 336 |
00453 <span class="keywordflow">if</span> (rr_data != NULL) |
| 337 |
00454 { |
| 338 |
00455 <a class="code" href="util_8h.html#a6">xfree</a>(rr_data); |
| 339 |
00456 } |
| 340 |
00457 |
| 341 |
00458 <span class="keywordflow">return</span>(NULL); |
| 342 |
00459 } |
| 343 |
00460 |
| 344 |
00461 <span class="comment">/* dname, type, class, TTL, rdata len, rdata */</span> |
| 345 |
00462 rd_ptr += rc; <span class="comment">/* jump to start of ANSWER data */</span> |
| 346 |
00463 GETSHORT(rd_type, rd_ptr); <span class="comment">/* get response type */</span> |
| 347 |
00464 rd_ptr += INT16SZ; <span class="comment">/* skip class */</span> |
| 348 |
00465 GETLONG(rd_ttl, rd_ptr); <span class="comment">/* get TTL */</span> |
| 349 |
00466 GETSHORT(rd_len, rd_ptr); <span class="comment">/* get data length */</span> |
| 350 |
00467 |
| 351 |
00468 *ttl = rd_ttl; <span class="comment">/* TTL working pointer */</span> |
| 352 |
00469 |
| 353 |
00470 <span class="keywordflow">if</span> (rd_type != T_TXT) |
| 354 |
00471 { |
| 355 |
00472 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Ignoring record not of T_TXT type. (%i)\n"</span>, rd_type); |
| 356 |
00473 rd_ptr += rd_len; |
| 357 |
00474 <span class="keywordflow">continue</span>; |
| 358 |
00475 } |
| 359 |
00476 |
| 360 |
00477 rd_ptr++; <span class="comment">/* skip byte */</span> |
| 361 |
00478 |
| 362 |
00479 rd_ptr[rd_len] = <span class="charliteral">'\0'</span>; |
| 363 |
00480 rd_ptr[rd_len - 1] = <span class="charliteral">' '</span>; |
| 364 |
00481 |
| 365 |
00482 i += rd_len; |
| 366 |
00483 |
| 367 |
00484 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Answer %i has length %i. (%i)\n"</span>, ancount, rd_len, i); |
| 368 |
00485 |
| 369 |
00486 <span class="comment">/*</span> |
| 370 |
00487 <span class="comment"> * Only received one answer, so this MUST start with v=spf1 or its</span> |
| 371 |
00488 <span class="comment"> * not a valid SPFv1 record</span> |
| 372 |
00489 <span class="comment"> */</span> |
| 373 |
00490 <span class="keywordflow">if</span> ((j == 1) && ((*rd_ptr != <span class="charliteral">'v'</span>) && (*(rd_ptr + 1) != <span class="charliteral">'='</span>))) |
| 374 |
00491 { |
| 375 |
00492 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"INVALID Answer Data: (%s) len: %i\n"</span>, rd_ptr, rd_len); |
| 376 |
00493 |
| 377 |
00494 <span class="keywordflow">if</span> (rr_data != NULL) |
| 378 |
00495 { |
| 379 |
00496 <a class="code" href="util_8h.html#a6">xfree</a>(rr_data); |
| 380 |
00497 } |
| 381 |
00498 |
| 382 |
00499 <span class="keywordflow">return</span>(NULL); |
| 383 |
00500 } |
| 384 |
00501 |
| 385 |
00502 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Answer Data: (%s) len: %i\n"</span>, rd_ptr, rd_len); |
| 386 |
00503 |
| 387 |
00504 <span class="keywordflow">if</span> ((rd_len <= SPF_MAXDNAME) && (rd_len > 0)) |
| 388 |
00505 { |
| 389 |
00506 <span class="keywordflow">if</span> (rr_data == NULL) |
| 390 |
00507 { |
| 391 |
00508 rr_data = <a class="code" href="util_8h.html#a4">xmalloc</a>(i + 1); |
| 392 |
00509 } |
| 393 |
00510 <span class="keywordflow">else</span> |
| 394 |
00511 { |
| 395 |
00512 rr_data = <a class="code" href="util_8h.html#a5">xrealloc</a>(rr_data, (i + 1)); |
| 396 |
00513 } |
| 397 |
00514 |
| 398 |
00515 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"REALLOCATE memory: %i bytes\n"</span>, i); |
| 399 |
00516 |
| 400 |
00517 strncat(rr_data, (<span class="keywordtype">char</span> *)rd_ptr, rd_len); |
| 401 |
00518 rr_data[i - 1] = <span class="charliteral">' '</span>; |
| 402 |
00519 rr_data[i] = <span class="charliteral">'\0'</span>; |
| 403 |
00520 } |
| 404 |
00521 |
| 405 |
00522 rd_ptr += rd_len; |
| 406 |
00523 ancount--; |
| 407 |
00524 } |
| 408 |
00525 |
| 409 |
00526 <span class="keywordflow">if</span> (rr_data == NULL) |
| 410 |
00527 { |
| 411 |
00528 <a class="code" href="util_8h.html#a11">xpprintf</a>(<span class="stringliteral">"rr_data is NULL (no ANSWERS in packet(s)), returning\n"</span>); |
| 412 |
00529 |
| 413 |
00530 <span class="keywordflow">return</span>(NULL); |
| 414 |
00531 } |
| 415 |
00532 |
| 416 |
00533 rr_data[i] = <span class="charliteral">'\0'</span>; |
| 417 |
00534 |
| 418 |
00535 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"RR_DATA: (%s)\n"</span>, rr_data); |
| 419 |
00536 |
| 420 |
00537 <span class="comment">/*</span> |
| 421 |
00538 <span class="comment"> * Comment: James Couzens <jcouzens@codeshare.ca></span> |
| 422 |
00539 <span class="comment"> *</span> |
| 423 |
00540 <span class="comment"> * Date: 09/08/04</span> |
| 424 |
00541 <span class="comment"> *</span> |
| 425 |
00542 <span class="comment"> * if: see if the string STARTS with v=spf1 </span> |
| 426 |
00543 <span class="comment"> * else: see if the string CONTAINS v=spf1 </span> |
| 427 |
00544 <span class="comment"> *</span> |
| 428 |
00545 <span class="comment"> * Whats all this?! This is because of the way DNS packets return -- that is</span> |
| 429 |
00546 <span class="comment"> * in random order. This is of consequence because of the wording in the RFC.</span> |
| 430 |
00547 <span class="comment"> * That wording is that the version identifier may only appear once withing any</span> |
| 431 |
00548 <span class="comment"> * given SPF record (this makes sense) and that should it appear twice, this</span> |
| 432 |
00549 <span class="comment"> * is considered a violation (also makes sense). The point here is that as a</span> |
| 433 |
00550 <span class="comment"> * result of records returning out of order (then how they were declared in</span> |
| 434 |
00551 <span class="comment"> * the server's configuration that they were requested from) and how this </span> |
| 435 |
00552 <span class="comment"> * particular implementation deals with the DNS packets (they are concatenated</span> |
| 436 |
00553 <span class="comment"> * in the order in which they were received) the following code facilitates an</span> |
| 437 |
00554 <span class="comment"> * early pre-parse check to see if its even a valid SPF record.</span> |
| 438 |
00555 <span class="comment"> *</span> |
| 439 |
00556 <span class="comment"> */</span> |
| 440 |
00557 <span class="keywordflow">if</span> ((*rr_data == <span class="charliteral">'v'</span>) && |
| 441 |
00558 (*(rr_data + 1) == <span class="charliteral">'='</span>) && |
| 442 |
00559 (*(rr_data + 2) == <span class="charliteral">'s'</span>) && |
| 443 |
00560 (*(rr_data + 3) == <span class="charliteral">'p'</span>) && |
| 444 |
00561 (*(rr_data + 4) == <span class="charliteral">'f'</span>) && |
| 445 |
00562 (*(rr_data + 5) == <span class="charliteral">'1'</span>)) |
| 446 |
00563 { |
| 447 |
00564 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Returning with valid SPFv1 record: (%s)\n"</span>, rr_data); |
| 448 |
00565 |
| 449 |
00566 <span class="keywordflow">return</span>(rr_data); |
| 450 |
00567 } |
| 451 |
00568 <span class="keywordflow">else</span> |
| 452 |
00569 { |
| 453 |
00570 <span class="comment">/* search the buffer for a valid SPFv1 version mechanism */</span> |
| 454 |
00571 <span class="keywordflow">if</span> ((pos = strstr(rr_data, <span class="stringliteral">"v=spf1"</span>)) != NULL) |
| 455 |
00572 { |
| 456 |
00573 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Found SPFv1 version mechanism: (%s)\n"</span>, pos); |
| 457 |
00574 |
| 458 |
00575 r_buf = <a class="code" href="util_8h.html#a8">xstrndup</a>(pos, <a class="code" href="spf_8h.html#a5">SPF_MAX_STR</a>); |
| 459 |
00576 r_buf[strlen(pos)] = <span class="charliteral">'\0'</span>; |
| 460 |
00577 |
| 461 |
00578 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Old buffer: (%s)\n"</span>, rr_data); |
| 462 |
00579 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"New buffer: (%s)\n"</span>, r_buf); |
| 463 |
00580 |
| 464 |
00581 pos = NULL; |
| 465 |
00582 } |
| 466 |
00583 |
| 467 |
00584 <span class="comment">/* no valid SPFv1 record here */</span> |
| 468 |
00585 <a class="code" href="util_8h.html#a6">xfree</a>(rr_data); |
| 469 |
00586 |
| 470 |
00587 <span class="keywordflow">return</span>(r_buf); |
| 471 |
00588 } |
| 472 |
00589 |
| 473 |
00590 <a class="code" href="util_8h.html#a11">xpprintf</a>(<span class="stringliteral">"Returning NULL (not a valid SPF TXT record)\n"</span>); |
| 474 |
00591 |
| 475 |
00592 <span class="keywordflow">return</span>(NULL); |
| 476 |
00593 } |
| 477 |
00594 |
| 478 |
00595 |
| 479 |
00596 <span class="comment">/* DNS_mx_answer</span> |
| 480 |
00597 <span class="comment">*</span> |
| 481 |
00598 <span class="comment">* Author: James Couzens <jcouzens@codeshare.ca></span> |
| 482 |
00599 <span class="comment">*</span> |
| 483 |
00600 <span class="comment">* Date: 01/02/04</span> |
| 484 |
00601 <span class="comment">* Date: 02/20/04 - Added cache by Travis Anderson <tanderson@codeshare.ca></span> |
| 485 |
00602 <span class="comment">*</span> |
| 486 |
00603 <span class="comment">* Desc:</span> |
| 487 |
00604 <span class="comment">* SPF_PACKETSZ bytes are allocated and then filled with \0 chars.</span> |
| 488 |
00605 <span class="comment">* This buffer is then used in an MX DNS query using data from the passed</span> |
| 489 |
00606 <span class="comment">* peer_info_t structure. Upon success this buffer is re-cast as a char *</span> |
| 490 |
00607 <span class="comment">* and then a pointer to this memory is returned. Upon failure a NULL</span> |
| 491 |
00608 <span class="comment">* pointer is returned.</span> |
| 492 |
00609 <span class="comment">*</span> |
| 493 |
00610 <span class="comment">*/</span> |
| 494 |
<a name="l00611"></a><a class="code" href="dns_8h.html#a10">00611</a> <span class="keywordtype">char</span> *<a class="code" href="dns_8h.html#a10">DNS_mx_answer</a>(int16_t ancount, <span class="keyword">const</span> u_char *msg_ptr, |
| 495 |
00612 <span class="keyword">const</span> u_char *eom_ptr, u_char *rd_ptr, <span class="keywordtype">char</span> *buf, <span class="keywordtype">int</span> *ttl) |
| 496 |
00613 { |
| 497 |
00614 size_t buf_len; <span class="comment">/* buffer length */</span> |
| 498 |
00615 |
| 499 |
00616 int16_t i; <span class="comment">/* utility */</span> |
| 500 |
00617 int16_t rc; <span class="comment">/* generic return code / length of */</span> |
| 501 |
00618 int16_t rd_pref; <span class="comment">/* MX preference */</span> |
| 502 |
00619 int16_t rd_type; <span class="comment">/* answer type */</span> |
| 503 |
00620 int16_t rd_len = 0; <span class="comment">/* res_search return code & packet len */</span> |
| 504 |
00621 |
| 505 |
00622 int32_t rd_ttl; <span class="comment">/* TTL */</span> |
| 506 |
00623 |
| 507 |
00624 <span class="keywordtype">char</span> *rr_data = NULL; <span class="comment">/* data pointer */</span> |
| 508 |
00625 |
| 509 |
00626 |
| 510 |
00627 i = 0; |
| 511 |
00628 <span class="keywordflow">while</span> ((ancount > 0) && (rd_ptr < eom_ptr)) |
| 512 |
00629 { |
| 513 |
00630 <span class="keywordflow">if</span> ((rc = dn_expand(msg_ptr, eom_ptr, rd_ptr, buf, <a class="code" href="dns_8h.html#a3">SPF_MAXCDNAME</a>)) < 0) |
| 514 |
00631 { |
| 515 |
00632 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Error expanding ANSWER packet at count %i; Reason: %s \n"</span>, |
| 516 |
00633 ancount, hstrerror(<a class="code" href="dns_8h.html#a6">h_errno</a>)); |
| 517 |
00634 |
| 518 |
00635 <span class="keywordflow">return</span>(NULL); |
| 519 |
00636 } |
| 520 |
00637 |
| 521 |
00638 <span class="comment">/* dname, type, class, TTL, rdata len, rdata */</span> |
| 522 |
00639 rd_ptr += rc; <span class="comment">/* jump to start of ANSWER data */</span> |
| 523 |
00640 GETSHORT(rd_type, rd_ptr); <span class="comment">/* get response type */</span> |
| 524 |
00641 rd_ptr += INT16SZ; <span class="comment">/* skip class */</span> |
| 525 |
00642 GETLONG(rd_ttl, rd_ptr); <span class="comment">/* get TTL */</span> |
| 526 |
00643 GETSHORT(rd_len, rd_ptr); <span class="comment">/* get data length */</span> |
| 527 |
00644 |
| 528 |
00645 *ttl = rd_ttl; |
| 529 |
00646 |
| 530 |
00647 <span class="keywordflow">if</span> (rd_type != T_MX) |
| 531 |
00648 { |
| 532 |
00649 <a class="code" href="util_8h.html#a9">xprintf</a>(<span class="stringliteral">"Forged packet?! We requested T_MX (15) but got %i\n"</span>, rd_type); |
| 533 |
00650 rd_ptr += rd_len; |
| 534 |
00651 <span class="keywordflow">continue</span>; |
| 535 |
00652 } |
| 536 |
00653 |
| 537 |
00654 GETSHORT(rd_pref, rd_ptr); <span class="comment">/* get MX preference */</span> |
| 538 |
00655 |
| 539 |
00656 <span class="keywordflow">if</span> ((rc = dn_expand(msg_ptr, eom_ptr, rd_ptr, buf, <a class="code" href="dns_8h.html#a3">SPF_MAXCDNAME</a>)) < 0) |
| 540 |
00657 { |
| 541 |
00658 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Error expanding ANSWER packet at count %i; Reason: %s \n"</span>, |
| 542 |
00659 ancount, hstrerror(<a class="code" href="dns_8h.html#a6">h_errno</a>)); |
| 543 |
00660 |
| 544 |
00661 <span class="keywordflow">return</span>(NULL); |
| 545 |
00662 } |
| 546 |
00663 |
| 547 |
00664 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"MX: %s Preference: %i\n"</span>, buf, rd_pref); |
| 548 |
00665 |
| 549 |
00666 buf_len = strlen(buf); |
| 550 |
00667 i += (buf_len + 1); |
| 551 |
00668 |
| 552 |
00669 <span class="keywordflow">if</span> ((rd_len <= SPF_MAXDNAME) && (rd_len > 0)) |
| 553 |
00670 { |
| 554 |
00671 <span class="keywordflow">if</span> (rr_data == NULL) |
| 555 |
00672 { |
| 556 |
00673 rr_data = <a class="code" href="util_8h.html#a4">xmalloc</a>(i + 1); |
| 557 |
00674 <span class="comment">/*memset(rr_data, '\0', (i + 1));*/</span> |
| 558 |
00675 } |
| 559 |
00676 <span class="keywordflow">else</span> |
| 560 |
00677 { |
| 561 |
00678 rr_data = <a class="code" href="util_8h.html#a5">xrealloc</a>(rr_data, (i + 1)); |
| 562 |
00679 } |
| 563 |
00680 |
| 564 |
00681 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"REALLOCATE memory: %i bytes\n"</span>, (i + 1)); |
| 565 |
00682 |
| 566 |
00683 strncat(rr_data, buf, buf_len); |
| 567 |
00684 rr_data[i - 1] = <span class="charliteral">' '</span>; |
| 568 |
00685 rr_data[i] = <span class="charliteral">'\0'</span>; |
| 569 |
00686 } |
| 570 |
00687 |
| 571 |
00688 rd_ptr += rc; |
| 572 |
00689 ancount--; |
| 573 |
00690 } |
| 574 |
00691 |
| 575 |
00692 <span class="keywordflow">if</span> (rr_data != NULL) |
| 576 |
00693 { |
| 577 |
00694 rr_data[i - 1] = <span class="charliteral">'\0'</span>; |
| 578 |
00695 } |
| 579 |
00696 |
| 580 |
00697 <span class="keywordflow">return</span>(rr_data); |
| 581 |
00698 } |
| 582 |
00699 |
| 583 |
00700 |
| 584 |
00701 <span class="comment">/* DNS_ptr_answer</span> |
| 585 |
00702 <span class="comment">*</span> |
| 586 |
00703 <span class="comment">* Author: James Couzens <jcouzens@codeshare.ca></span> |
| 587 |
00704 <span class="comment">*</span> |
| 588 |
00705 <span class="comment">* Date: 01/02/04</span> |
| 589 |
00706 <span class="comment">* Date: 02/20/04 - Added cache by Travis Anderson <tanderson@codeshare.ca></span> |
| 590 |
00707 <span class="comment">*</span> |
| 591 |
00708 <span class="comment">* Desc:</span> |
| 592 |
00709 <span class="comment">* A reverse lookup on an IP address leads to a lookup per returned</span> |
| 593 |
00710 <span class="comment">* PTR answer to see if the returned answer matches. The forward lookups are</span> |
| 594 |
00711 <span class="comment">* handled by a separate function which calls gethostbyname. Upon a single</span> |
| 595 |
00712 <span class="comment">* successful match of a forward lookup with a reverse lookup, returns SPF_TRUE.</span> |
| 596 |
00713 <span class="comment">* Returns SPF_FALSE upon failure.</span> |
| 597 |
00714 <span class="comment">*</span> |
| 598 |
00715 <span class="comment">*/</span> |
| 599 |
<a name="l00716"></a><a class="code" href="dns_8h.html#a11">00716</a> <a class="code" href="spf_8h.html#a35">SPF_BOOL</a> <a class="code" href="dns_8h.html#a11">DNS_ptr_answer</a>(<a class="code" href="structpeer__info__s.html">peer_info_t</a> *p, int16_t ancount, |
| 600 |
00717 <span class="keyword">const</span> u_char *msg_ptr, <span class="keyword">const</span> u_char *eom_ptr, u_char *rd_ptr, <span class="keywordtype">char</span> *buf, |
| 601 |
00718 <span class="keyword">const</span> <span class="keywordtype">char</span> *mta, <span class="keywordtype">int</span> *ttl) |
| 602 |
00719 { |
| 603 |
00720 int16_t rc; <span class="comment">/* generic return code / length of */</span> |
| 604 |
00721 int16_t rd_type; <span class="comment">/* answer type */</span> |
| 605 |
00722 int16_t rd_len = 0; <span class="comment">/* res_search return code & packet len */</span> |
| 606 |
00723 |
| 607 |
00724 int32_t rd_ttl; <span class="comment">/* TTL */</span> |
| 608 |
00725 |
| 609 |
00726 <span class="keywordtype">char</span> *buf_cmp = NULL; <span class="comment">/* stores domain from buf's (ptr res) hostname */</span> |
| 610 |
00727 <span class="keywordtype">char</span> *mta_cmp = NULL; <span class="comment">/* stores domain from rpeer's hostname */</span> |
| 611 |
00728 |
| 612 |
00729 |
| 613 |
00730 <span class="keywordflow">while</span> ((ancount > 0) && (rd_ptr < eom_ptr)) |
| 614 |
00731 { |
| 615 |
00732 <span class="keywordflow">if</span> ((rc = dn_expand(msg_ptr, eom_ptr, rd_ptr, buf, <a class="code" href="dns_8h.html#a3">SPF_MAXCDNAME</a>)) < 0) |
| 616 |
00733 { |
| 617 |
00734 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Error expanding ANSWER packet at count %i; Reason: %s \n"</span>, |
| 618 |
00735 ancount, hstrerror(<a class="code" href="dns_8h.html#a6">h_errno</a>)); |
| 619 |
00736 |
| 620 |
00737 <span class="keywordflow">return</span>(<a class="code" href="spf_8h.html#a87a49">SPF_FALSE</a>); |
| 621 |
00738 } |
| 622 |
00739 |
| 623 |
00740 <span class="comment">/* dname, type, class, TTL, rdata len, rdata */</span> |
| 624 |
00741 rd_ptr += rc; <span class="comment">/* jump to start of ANSWER data */</span> |
| 625 |
00742 GETSHORT(rd_type, rd_ptr); <span class="comment">/* get response type */</span> |
| 626 |
00743 rd_ptr += INT16SZ; <span class="comment">/* skip class */</span> |
| 627 |
00744 GETLONG(rd_ttl, rd_ptr); <span class="comment">/* get TTL */</span> |
| 628 |
00745 GETSHORT(rd_len, rd_ptr); <span class="comment">/* get data length */</span> |
| 629 |
00746 |
| 630 |
00747 *ttl = rd_ttl; |
| 631 |
00748 |
| 632 |
00749 <span class="keywordflow">if</span> (rd_type != T_PTR) |
| 633 |
00750 { |
| 634 |
00751 rc = dn_expand(msg_ptr, eom_ptr, rd_ptr, buf, <a class="code" href="dns_8h.html#a3">SPF_MAXCDNAME</a>); |
| 635 |
00752 |
| 636 |
00753 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Error expanding ANSWER packet at count %i; Reason: %s \n"</span>, |
| 637 |
00754 ancount, hstrerror(<a class="code" href="dns_8h.html#a6">h_errno</a>)); |
| 638 |
00755 |
| 639 |
00756 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Got answer to type %i (%s) when we asked for T_PTR (%i)\n"</span>, |
| 640 |
00757 rd_type, buf, T_PTR); |
| 641 |
00758 |
| 642 |
00759 rd_ptr += rd_len; |
| 643 |
00760 <span class="keywordflow">continue</span>; |
| 644 |
00761 } |
| 645 |
00762 |
| 646 |
00763 <span class="keywordflow">if</span> ((rc = dn_expand(msg_ptr, eom_ptr, rd_ptr, buf, <a class="code" href="dns_8h.html#a3">SPF_MAXCDNAME</a>)) < 0) |
| 647 |
00764 { |
| 648 |
00765 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Error expanding ANSWER packet at count %i; Reason: %s \n"</span>, |
| 649 |
00766 ancount, hstrerror(<a class="code" href="dns_8h.html#a6">h_errno</a>)); |
| 650 |
00767 |
| 651 |
00768 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Error expanding ANSWER packet at count %i. (%s)\n"</span>, |
| 652 |
00769 ancount, buf); |
| 653 |
00770 |
| 654 |
00771 <span class="keywordflow">return</span>(<a class="code" href="spf_8h.html#a87a49">SPF_FALSE</a>); |
| 655 |
00772 } |
| 656 |
00773 |
| 657 |
00774 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Answer %i has length %i.\n"</span>, ancount, rd_len); |
| 658 |
00775 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Answer data (buffer): (%s); buffer length: %i\n"</span>, |
| 659 |
00776 buf, strlen(buf)); |
| 660 |
00777 |
| 661 |
00778 <span class="keywordflow">if</span> ((rd_len <= SPF_MAXDNAME) && (rd_len > 0)) |
| 662 |
00779 { |
| 663 |
00780 <span class="keywordflow">if</span> (<a class="code" href="util_8h.html#a54">UTIL_validate_hostname</a>(p, buf, 32) == <a class="code" href="spf_8h.html#a87a49">SPF_FALSE</a>) |
| 664 |
00781 { |
| 665 |
00782 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Unable to validate hostname (%s) with (%s)\n"</span>, |
| 666 |
00783 buf, mta); |
| 667 |
00784 |
| 668 |
00785 rd_ptr += rc; |
| 669 |
00786 ancount--; |
| 670 |
00787 <span class="keywordflow">continue</span>; |
| 671 |
00788 } |
| 672 |
00789 |
| 673 |
00790 <span class="comment">/* buf MUST be a subdomain of mta */</span> |
| 674 |
00791 <span class="keywordflow">if</span> (strlen(buf) < strlen(mta)) |
| 675 |
00792 { |
| 676 |
00793 <span class="comment">/* not a chance */</span> |
| 677 |
00794 rd_ptr += rc; |
| 678 |
00795 ancount--; |
| 679 |
00796 <span class="keywordflow">continue</span>; |
| 680 |
00797 } |
| 681 |
00798 <span class="keywordflow">else</span> <span class="keywordflow">if</span> (strlen(buf) == strlen(mta)) |
| 682 |
00799 { |
| 683 |
00800 <span class="keywordflow">if</span> (strcasecmp(buf, mta) == 0) |
| 684 |
00801 { |
| 685 |
00802 <span class="keywordflow">return</span> (<a class="code" href="spf_8h.html#a87a50">SPF_TRUE</a>); |
| 686 |
00803 } |
| 687 |
00804 <span class="keywordflow">else</span> |
| 688 |
00805 { |
| 689 |
00806 rd_ptr += rc; |
| 690 |
00807 ancount--; |
| 691 |
00808 <span class="keywordflow">continue</span>; |
| 692 |
00809 } |
| 693 |
00810 } |
| 694 |
00811 <span class="keywordflow">else</span> |
| 695 |
00812 { |
| 696 |
00813 buf_cmp = &(buf[strlen(buf) - 1]); |
| 697 |
00814 mta_cmp = (<span class="keywordtype">char</span> *)&(mta[strlen(mta) - 1]); |
| 698 |
00815 |
| 699 |
00816 <span class="keywordflow">while</span> (mta_cmp != mta - 1) |
| 700 |
00817 { |
| 701 |
00818 <span class="keywordflow">if</span> (*mta_cmp-- != *buf_cmp--) |
| 702 |
00819 { |
| 703 |
00820 rd_ptr += rc; |
| 704 |
00821 ancount--; |
| 705 |
00822 <span class="keywordflow">continue</span>; |
| 706 |
00823 } |
| 707 |
00824 } |
| 708 |
00825 |
| 709 |
00826 <span class="keywordflow">if</span> (*buf_cmp == <span class="charliteral">'.'</span>) |
| 710 |
00827 { |
| 711 |
00828 <span class="keywordflow">return</span> (<a class="code" href="spf_8h.html#a87a50">SPF_TRUE</a>); |
| 712 |
00829 } |
| 713 |
00830 <span class="keywordflow">else</span> |
| 714 |
00831 { |
| 715 |
00832 rd_ptr += rc; |
| 716 |
00833 ancount--; |
| 717 |
00834 <span class="keywordflow">continue</span>; |
| 718 |
00835 } |
| 719 |
00836 } |
| 720 |
00837 } |
| 721 |
00838 <span class="keywordflow">else</span> |
| 722 |
00839 { |
| 723 |
00840 <a class="code" href="util_8h.html#a13">xepprintf</a>(<span class="stringliteral">"Answer length is too long!\n"</span>); |
| 724 |
00841 } |
| 725 |
00842 |
| 726 |
00843 rd_ptr += rc; |
| 727 |
00844 ancount--; |
| 728 |
00845 } |
| 729 |
00846 |
| 730 |
00847 <span class="keywordflow">return</span>(<a class="code" href="spf_8h.html#a87a49">SPF_FALSE</a>); |
| 731 |
00848 } |
| 732 |
00849 |
| 733 |
00850 |
| 734 |
00851 <span class="comment">/* DNS_cname_answer</span> |
| 735 |
00852 <span class="comment">*</span> |
| 736 |
00853 <span class="comment">* Author: Teddy <teddy@teddy.ch></span> |
| 737 |
00854 <span class="comment">*</span> |
| 738 |
00855 <span class="comment">* Date: 29/04/04</span> |
| 739 |
00856 <span class="comment">* Date: 02/20/04 - Added cache by Travis Anderson <tanderson@codeshare.ca></span> |
| 740 |
00857 <span class="comment">*</span> |
| 741 |
00858 <span class="comment">* Desc:</span> |
| 742 |
00859 <span class="comment">* SPF_PACKETSZ bytes are allocated and then filled with \0 chars.</span> |
| 743 |
00860 <span class="comment">* This buffer is then used in a TXT DNS query using data from the passed</span> |
| 744 |
00861 <span class="comment">* peer_info_t structure. Upon success this buffer is re-cast as a char *</span> |
| 745 |
00862 <span class="comment">* and then a pointer to this memory is returned. Upon failure a NULL</span> |
| 746 |
00863 <span class="comment">* pointer is returned.</span> |
| 747 |
00864 <span class="comment">*</span> |
| 748 |
00865 <span class="comment">*/</span> |
| 749 |
<a name="l00866"></a><a class="code" href="dns_8h.html#a12">00866</a> <span class="keywordtype">char</span> *<a class="code" href="dns_8h.html#a12">DNS_cname_answer</a>(int16_t ancount, <span class="keyword">const</span> u_char *msg_ptr, |
| 750 |
00867 <span class="keyword">const</span> u_char *eom_ptr, u_char *rd_ptr, <span class="keywordtype">char</span> *buf, <span class="keywordtype">int</span> *ttl) |
| 751 |
00868 { |
| 752 |
00869 int16_t i; <span class="comment">/* utility */</span> |
| 753 |
00870 int16_t rc; <span class="comment">/* generic return code / length of */</span> |
| 754 |
00871 int16_t rd_type; <span class="comment">/* answer type */</span> |
| 755 |
00872 int16_t rd_len; <span class="comment">/* res_search return code & packet len */</span> |
| 756 |
00873 |
| 757 |
00874 int32_t rd_ttl; <span class="comment">/* TTL */</span> |
| 758 |
00875 |
| 759 |
00876 size_t buf_len; <span class="comment">/* buffer length */</span> |
| 760 |
00877 |
| 761 |
00878 <span class="keywordtype">char</span> *rr_data = NULL; <span class="comment">/* data pointer */</span> |
| 762 |
00879 |
| 763 |
00880 |
| 764 |
00881 <span class="keywordflow">if</span> ((msg_ptr == NULL) || (eom_ptr == NULL) || |
| 765 |
00882 (rd_ptr == NULL) || (buf == NULL)) |
| 766 |
00883 { |
| 767 |
00884 <a class="code" href="util_8h.html#a13">xepprintf</a>(<span class="stringliteral">"Called with NULL pointers\n"</span>); |
| 768 |
00885 |
| 769 |
00886 <span class="keywordflow">return</span>(NULL); |
| 770 |
00887 } |
| 771 |
00888 |
| 772 |
00889 <a class="code" href="util_8h.html#a11">xpprintf</a>(<span class="stringliteral">"entering function\n"</span>); |
| 773 |
00890 |
| 774 |
00891 i = 0; |
| 775 |
00892 <span class="keywordflow">while</span> ((ancount > 0) && (rd_ptr < eom_ptr)) |
| 776 |
00893 { |
| 777 |
00894 <span class="keywordflow">if</span> ((rc = dn_expand(msg_ptr, eom_ptr, rd_ptr, buf, <a class="code" href="dns_8h.html#a3">SPF_MAXCDNAME</a>)) < 0) |
| 778 |
00895 { |
| 779 |
00896 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Error expanding ANSWER packet at count %i; Reason: %s \n"</span>, |
| 780 |
00897 ancount, hstrerror(<a class="code" href="dns_8h.html#a6">h_errno</a>)); |
| 781 |
00898 |
| 782 |
00899 <span class="keywordflow">return</span>(NULL); |
| 783 |
00900 } |
| 784 |
00901 |
| 785 |
00902 <span class="comment">/* dname, type, class, TTL, rdata len, rdata */</span> |
| 786 |
00903 rd_ptr += rc; <span class="comment">/* jump to start of ANSWER data */</span> |
| 787 |
00904 GETSHORT(rd_type, rd_ptr); <span class="comment">/* get response type */</span> |
| 788 |
00905 rd_ptr += INT16SZ; <span class="comment">/* skip class */</span> |
| 789 |
00906 GETLONG(rd_ttl, rd_ptr); <span class="comment">/* get TTL */</span> |
| 790 |
00907 GETSHORT(rd_len, rd_ptr); <span class="comment">/* get data length */</span> |
| 791 |
00908 |
| 792 |
00909 *ttl = rd_ttl; |
| 793 |
00910 |
| 794 |
00911 <span class="keywordflow">if</span> (rd_type != T_CNAME) |
| 795 |
00912 { |
| 796 |
00913 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Ignoring record not of T_CNAME type. (%i)\n"</span>, rd_type); |
| 797 |
00914 rd_ptr += rd_len; |
| 798 |
00915 <span class="keywordflow">continue</span>; |
| 799 |
00916 } |
| 800 |
00917 |
| 801 |
00918 <span class="keywordflow">if</span> (dn_expand(msg_ptr, eom_ptr, rd_ptr, buf, <a class="code" href="dns_8h.html#a3">SPF_MAXCDNAME</a>) < 0) |
| 802 |
00919 { |
| 803 |
00920 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Error expanding ANSWER packet at count %i; Reason: %s \n"</span>, |
| 804 |
00921 ancount, hstrerror(<a class="code" href="dns_8h.html#a6">h_errno</a>)); |
| 805 |
00922 |
| 806 |
00923 <span class="keywordflow">return</span>(NULL); |
| 807 |
00924 } |
| 808 |
00925 |
| 809 |
00926 buf_len = strlen(buf); |
| 810 |
00927 i += (buf_len + 1); |
| 811 |
00928 |
| 812 |
00929 <span class="keywordflow">if</span> ((rd_len <= SPF_MAXDNAME) && (rd_len > 0)) |
| 813 |
00930 { |
| 814 |
00931 <span class="keywordflow">if</span> (rr_data == NULL) |
| 815 |
00932 { |
| 816 |
00933 rr_data = <a class="code" href="util_8h.html#a4">xmalloc</a>(i + 1); |
| 817 |
00934 <span class="comment">/*memset(rr_data, '\0', (i + 1));*/</span> |
| 818 |
00935 } |
| 819 |
00936 <span class="keywordflow">else</span> |
| 820 |
00937 { |
| 821 |
00938 rr_data = <a class="code" href="util_8h.html#a5">xrealloc</a>(rr_data, (i + 1)); |
| 822 |
00939 } |
| 823 |
00940 |
| 824 |
00941 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"REALLOCATE memory: %i bytes\n"</span>, (i + 1)); |
| 825 |
00942 |
| 826 |
00943 strncat(rr_data, buf, buf_len); |
| 827 |
00944 rr_data[i - 1] = <span class="charliteral">' '</span>; |
| 828 |
00945 rr_data[i] = <span class="charliteral">'\0'</span>; |
| 829 |
00946 } |
| 830 |
00947 |
| 831 |
00948 rd_ptr += rc; |
| 832 |
00949 ancount--; |
| 833 |
00950 } |
| 834 |
00951 |
| 835 |
00952 <span class="keywordflow">if</span> (rr_data != NULL) |
| 836 |
00953 { |
| 837 |
00954 rr_data[i - 1] = <span class="charliteral">'\0'</span>; |
| 838 |
00955 } |
| 839 |
00956 |
| 840 |
00957 <a class="code" href="util_8h.html#a11">xpprintf</a>(<span class="stringliteral">"leaving function\n"</span>); |
| 841 |
00958 <span class="keywordflow">return</span>(rr_data); |
| 842 |
00959 } |
| 843 |
00960 |
| 844 |
00961 |
| 845 |
00962 <span class="comment">/* DNS_check_client_reverse</span> |
| 846 |
00963 <span class="comment">*</span> |
| 847 |
00964 <span class="comment">* Author: Travis Anderson <tanderson@codeshare.ca></span> |
| 848 |
00965 <span class="comment">* Adapted from DNS_query</span> |
| 849 |
00966 <span class="comment">*</span> |
| 850 |
00967 <span class="comment">* Date: 08/??/04 </span> |
| 851 |
00968 <span class="comment">*</span> |
| 852 |
00969 <span class="comment">* Desc:</span> |
| 853 |
00970 <span class="comment">* First get addr's reverse then for each hostname returned, </span> |
| 854 |
00971 <span class="comment">* resolve it and then see if it matches addr. If a match is found return </span> |
| 855 |
00972 <span class="comment">* SPF_TRUE if not return SPF_FALSE.</span> |
| 856 |
00973 <span class="comment">*</span> |
| 857 |
00974 <span class="comment">*/</span> |
| 858 |
<a name="l00975"></a><a class="code" href="dns_8h.html#a13">00975</a> <a class="code" href="spf_8h.html#a35">SPF_BOOL</a> <a class="code" href="dns_8h.html#a13">DNS_check_client_reverse</a>(<a class="code" href="structpeer__info__s.html">peer_info_t</a> *p) |
| 859 |
00976 { |
| 860 |
00977 |
| 861 |
00978 HEADER *hdr; <span class="comment">/* pointer to the header of the packet */</span> |
| 862 |
00979 |
| 863 |
00980 int8_t ancount; <span class="comment">/* number of answers */</span> |
| 864 |
00981 |
| 865 |
00982 int16_t rd_type; <span class="comment">/* answer type */</span> |
| 866 |
00983 int16_t rd_len = 0; <span class="comment">/* res_search return code & packet len */</span> |
| 867 |
00984 int16_t r_len; <span class="comment">/* res_search return code & packet len */</span> |
| 868 |
00985 int16_t rc; <span class="comment">/* generic return code / length of */</span> |
| 869 |
00986 |
| 870 |
00987 <span class="keywordtype">char</span> buf[<a class="code" href="dns_8h.html#a2">SPF_MAXDNAME</a>]; <span class="comment">/* record extraction buffer */</span> |
| 871 |
00988 <span class="keywordtype">char</span> answer[<a class="code" href="dns_8h.html#a1">SPF_PACKETSZ</a>]; <span class="comment">/* answer buffer */</span> |
| 872 |
00989 |
| 873 |
00990 <span class="keywordtype">char</span> *addr_arpa = NULL; <span class="comment">/* reverse address in dot-quad notation */</span> |
| 874 |
00991 |
| 875 |
00992 u_char *msg_ptr; <span class="comment">/* pointer to beginning of the message */</span> |
| 876 |
00993 u_char *eom_ptr; <span class="comment">/* pointer to the end of the message */</span> |
| 877 |
00994 u_char *rd_ptr; <span class="comment">/* pointer to uncompressed message */</span> |
| 878 |
00995 |
| 879 |
00996 |
| 880 |
00997 <span class="keywordflow">if</span> (p == NULL) |
| 881 |
00998 { |
| 882 |
00999 <a class="code" href="util_8h.html#a13">xepprintf</a>(<span class="stringliteral">"Unable to continue, peer info struct is NULL!\n"</span>); |
| 883 |
01000 |
| 884 |
01001 <span class="keywordflow">return</span>(<a class="code" href="spf_8h.html#a87a49">SPF_FALSE</a>); |
| 885 |
01002 } |
| 886 |
01003 |
| 887 |
01004 <a class="code" href="util_8h.html#a11">xpprintf</a>(<span class="stringliteral">"entering function\n"</span>); |
| 888 |
01005 |
| 889 |
01006 addr_arpa = <a class="code" href="util_8h.html#a50">UTIL_rev_addr</a>(p-><a class="code" href="structpeer__info__s.html#o17">r_ip</a>); |
| 890 |
01007 |
| 891 |
01008 r_len = res_search(addr_arpa, C_IN, T_PTR, (u_char *)answer, |
| 892 |
01009 <a class="code" href="dns_8h.html#a1">SPF_PACKETSZ</a>); |
| 893 |
01010 |
| 894 |
01011 <a class="code" href="util_8h.html#a6">xfree</a>(addr_arpa); |
| 895 |
01012 |
| 896 |
01013 hdr = (HEADER *)&answer; |
| 897 |
01014 ancount = ntohs(hdr->ancount); |
| 898 |
01015 |
| 899 |
01016 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Received packet size of %i bytes which contains %i answers.\n"</span>, |
| 900 |
01017 r_len, ancount); |
| 901 |
01018 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"ANSWERS: %i\n"</span>, ancount); |
| 902 |
01019 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"QUESTIONS: %i\n"</span>, ntohs(hdr->qdcount)); |
| 903 |
01020 |
| 904 |
01021 <span class="keywordflow">if</span> (ancount > 0) |
| 905 |
01022 { |
| 906 |
01023 msg_ptr = (u_char *)&answer; <span class="comment">/* point to start of message */</span> |
| 907 |
01024 eom_ptr = ((u_char *)&answer + r_len); <span class="comment">/* point to end of message */</span> |
| 908 |
01025 rd_ptr = ((u_char *)&answer + HFIXEDSZ); <span class="comment">/* point to start of RDATA */</span> |
| 909 |
01026 |
| 910 |
01027 <span class="keywordflow">if</span> ((rc = dn_skipname(rd_ptr, eom_ptr)) < 0) |
| 911 |
01028 { |
| 912 |
01029 <a class="code" href="util_8h.html#a13">xepprintf</a>(<span class="stringliteral">"Error obtaining QUESTION!\n"</span>); |
| 913 |
01030 |
| 914 |
01031 <span class="keywordflow">return</span>(<a class="code" href="spf_8h.html#a87a49">SPF_FALSE</a>); |
| 915 |
01032 } |
| 916 |
01033 |
| 917 |
01034 rd_ptr += rc + QFIXEDSZ; <span class="comment">/* jump to start of ANSWER */</span> |
| 918 |
01035 |
| 919 |
01036 <span class="keywordflow">while</span> ((ancount > 0) && (rd_ptr < eom_ptr)) |
| 920 |
01037 { |
| 921 |
01038 <span class="keywordflow">if</span> ((rc = dn_expand(msg_ptr, eom_ptr, rd_ptr, buf, <a class="code" href="dns_8h.html#a3">SPF_MAXCDNAME</a>)) < 0) |
| 922 |
01039 { |
| 923 |
01040 <a class="code" href="util_8h.html#a12">xeprintf</a>(<span class="stringliteral">"Error expanding ANSWER packet at count %i. (%s)\n"</span>, |
| 924 |
01041 ancount, buf); |
| 925 |
01042 |
| 926 |
01043 <span class="keywordflow">return</span>(<a class="code" href="spf_8h.html#a87a49">SPF_FALSE</a>); |
| 927 |
01044 } |
| 928 |
01045 |
| 929 |
01046 <span class="comment">/* dname, type, class, TTL, rdata len, rdata */</span> |
| 930 |
01047 rd_ptr += rc; <span class="comment">/* jump to start of ANSWER data */</span> |
| 931 |
01048 GETSHORT(rd_type, rd_ptr); <span class="comment">/* get response type */</span> |
| 932 |
01049 rd_ptr += INT16SZ; <span class="comment">/* skip class */</span> |
| 933 |
01050 rd_ptr += INT32SZ; <span class="comment">/* skip TTL */</span> |
| 934 |
01051 GETSHORT(rd_len, rd_ptr); <span class="comment">/* get data length */</span> |
| 935 |
01052 |
| 936 |
01053 <span class="keywordflow">if</span> (rd_type != T_PTR) |
| 937 |
01054 { |
| 938 |
01055 rc = dn_expand(msg_ptr, eom_ptr, rd_ptr, buf, <a class="code" href="dns_8h.html#a3">SPF_MAXCDNAME</a>); |
| 939 |
01056 |
| 940 |
01057 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Got answer to type %i (%s) when we asked for T_PTR (%i)\n"</span>, |
| 941 |
01058 rd_type, buf, T_PTR); |
| 942 |
01059 |
| 943 |
01060 rd_ptr += rd_len; |
| 944 |
01061 <span class="keywordflow">continue</span>; |
| 945 |
01062 } |
| 946 |
01063 |
| 947 |
01064 <span class="keywordflow">if</span> ((rc = dn_expand(msg_ptr, eom_ptr, rd_ptr, buf, <a class="code" href="dns_8h.html#a3">SPF_MAXCDNAME</a>)) < 0) |
| 948 |
01065 { |
| 949 |
01066 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Error expanding ANSWER packet at count %i. (%s)\n"</span>, |
| 950 |
01067 ancount, buf); |
| 951 |
01068 |
| 952 |
01069 <span class="keywordflow">return</span>(<a class="code" href="spf_8h.html#a87a49">SPF_FALSE</a>); |
| 953 |
01070 } |
| 954 |
01071 |
| 955 |
01072 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Answer %i has length %i.\n"</span>, ancount, rd_len); |
| 956 |
01073 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Answer data (buffer): (%s); data length: %i\n"</span>, |
| 957 |
01074 buf, strlen(buf)); |
| 958 |
01075 |
| 959 |
01076 <span class="keywordflow">if</span> ((rd_len <= SPF_MAXDNAME) && (rd_len > 0)) |
| 960 |
01077 { |
| 961 |
01078 <span class="keywordflow">if</span> (<a class="code" href="util_8h.html#a54">UTIL_validate_hostname</a>(p, buf, 32) == <a class="code" href="spf_8h.html#a87a49">SPF_FALSE</a>) |
| 962 |
01079 { |
| 963 |
01080 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"Unable to validate hostname (%s) with (%s)\n"</span>, |
| 964 |
01081 buf, p-><a class="code" href="structpeer__info__s.html#o17">r_ip</a>); |
| 965 |
01082 |
| 966 |
01083 rd_ptr += rc; |
| 967 |
01084 ancount--; |
| 968 |
01085 <span class="keywordflow">continue</span>; |
| 969 |
01086 } |
| 970 |
01087 <span class="keywordflow">else</span> |
| 971 |
01088 { |
| 972 |
01089 <span class="keywordflow">if</span> (p-><a class="code" href="structpeer__info__s.html#o18">r_vhname</a> != NULL) |
| 973 |
01090 { |
| 974 |
01091 <a class="code" href="util_8h.html#a6">xfree</a>(p-><a class="code" href="structpeer__info__s.html#o18">r_vhname</a>); |
| 975 |
01092 } |
| 976 |
01093 |
| 977 |
01094 p-><a class="code" href="structpeer__info__s.html#o18">r_vhname</a> = <a class="code" href="util_8h.html#a8">xstrndup</a>(buf, strlen(buf) + 1); |
| 978 |
01095 |
| 979 |
01096 <span class="keywordflow">return</span>(<a class="code" href="spf_8h.html#a87a50">SPF_TRUE</a>); |
| 980 |
01097 } <span class="comment">/* if (UTIL_validate.. */</span> |
| 981 |
01098 } |
| 982 |
01099 <span class="keywordflow">else</span> |
| 983 |
01100 { |
| 984 |
01101 <a class="code" href="util_8h.html#a13">xepprintf</a>(<span class="stringliteral">"Answer length is too long!\n"</span>); |
| 985 |
01102 <span class="keywordflow">continue</span>; |
| 986 |
01103 } |
| 987 |
01104 |
| 988 |
01105 rd_ptr += rc; |
| 989 |
01106 ancount--; |
| 990 |
01107 |
| 991 |
01108 } <span class="comment">/* if (rd_len */</span> |
| 992 |
01109 } <span class="comment">/* while (ancount */</span> |
| 993 |
01110 |
| 994 |
01111 <span class="keywordflow">return</span>(<a class="code" href="spf_8h.html#a87a49">SPF_FALSE</a>); |
| 995 |
01112 } |
| 996 |
01113 |
| 997 |
01114 <span class="preprocessor">#ifdef _WITH_PTHREADS</span> |
| 998 |
01115 <span class="preprocessor"></span><span class="preprocessor"> #ifdef HAVE_GETHOSTBYNAME_R</span> |
| 999 |
01116 <span class="preprocessor"></span> |
| 1000 |
01117 <span class="comment">/* _DNS_gethostbyname_r</span> |
| 1001 |
01118 <span class="comment">*</span> |
| 1002 |
01119 <span class="comment">* Author: James Couzens <jcouzens@codeshare.ca></span> |
| 1003 |
01120 <span class="comment">* Date: 08/28/04</span> |
| 1004 |
01121 <span class="comment">*</span> |
| 1005 |
01122 <span class="comment">* Desc:</span> |
| 1006 |
01123 <span class="comment">* A wrapper around the GNU gethostbyname_r extension function which</span> |
| 1007 |
01124 <span class="comment">* introduces reentrant (some) resolver functionality allbeit way too bloody</span> |
| 1008 |
01125 <span class="comment">* late. Someone smack me with a tire iron and rewrite all of this using DJB.</span> |
| 1009 |
01126 <span class="comment">*</span> |
| 1010 |
01127 <span class="comment">* This function is intented to be wrapped by a MACRO going by something along</span> |
| 1011 |
01128 <span class="comment">* the lines of 'xgethostbyname' or 'xgethostbyname_r'.</span> |
| 1012 |
01129 <span class="comment">*</span> |
| 1013 |
01130 <span class="comment">*/</span> |
| 1014 |
01131 <span class="keyword">struct </span>hostent *_DNS_GNU_gethostbyname_r(<span class="keyword">const</span> <span class="keywordtype">char</span> *name, |
| 1015 |
01132 <span class="keyword">struct</span> hostent *result, <span class="keywordtype">char</span> *buf, <span class="keywordtype">int</span> buf_len, <span class="keywordtype">int</span> *h_errnop) |
| 1016 |
01133 { |
| 1017 |
01134 <span class="keyword">struct </span>hostent *hp = NULL; <span class="comment">/* hostent structure */</span> |
| 1018 |
01135 |
| 1019 |
01136 |
| 1020 |
01137 <span class="keywordflow">if</span> (!name) |
| 1021 |
01138 { |
| 1022 |
01139 <a class="code" href="util_8h.html#a13">xepprintf</a>(<span class="stringliteral">"ERROR: No hostname to resolve.\n"</span>); |
| 1023 |
01140 |
| 1024 |
01141 <span class="keywordflow">return</span>(NULL); |
| 1025 |
01142 } |
| 1026 |
01143 |
| 1027 |
01144 <a class="code" href="util_8h.html#a11">xpprintf</a>(<span class="stringliteral">"entering function\n"</span>); |
| 1028 |
01145 |
| 1029 |
01146 <span class="keywordflow">if</span> (buf_len >= <a class="code" href="spf_8h.html#a5">SPF_MAX_STR</a>) |
| 1030 |
01147 { |
| 1031 |
01148 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"buf_len (%i) is > max size (%i); Disregarded.\n"</span>, |
| 1032 |
01149 buf_len, SPF_MAX_STR); |
| 1033 |
01150 |
| 1034 |
01151 <span class="keywordflow">return</span>(NULL); |
| 1035 |
01152 } |
| 1036 |
01153 |
| 1037 |
01154 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"called with hostname (%s)\n"</span>, name); |
| 1038 |
01155 memset(buf, <span class="charliteral">'\0'</span>, SPF_MAX_GHBNR_DBUF); |
| 1039 |
01156 hp = <a class="code" href="util_8h.html#a4">xmalloc</a>(<a class="code" href="util_8h.html#a3">SIZEOF</a>(<span class="keyword">struct</span> hostent)); |
| 1040 |
01157 |
| 1041 |
01158 gethostbyname_r(name, result, buf, (size_t)buf_len, &hp, h_errnop); |
| 1042 |
01159 |
| 1043 |
01160 <a class="code" href="util_8h.html#a11">xpprintf</a>(<span class="stringliteral">"leaving function\n"</span>); |
| 1044 |
01161 |
| 1045 |
01162 <span class="keywordflow">return</span>(hp); |
| 1046 |
01163 } |
| 1047 |
01164 |
| 1048 |
01165 <span class="preprocessor"> #else </span><span class="comment">/* HAVE_GETHOSTBYNAME_R */</span> |
| 1049 |
01166 |
| 1050 |
01167 <span class="comment">/* _DNS_gethostbyname_r</span> |
| 1051 |
01168 <span class="comment">*</span> |
| 1052 |
01169 <span class="comment">* Author: James Couzens <jcouzens@codeshare.ca></span> |
| 1053 |
01170 <span class="comment">* Date: 08/28/04</span> |
| 1054 |
01171 <span class="comment">*</span> |
| 1055 |
01172 <span class="comment">* Desc:</span> |
| 1056 |
01173 <span class="comment">* Reentrant version of gethostbyname_r which is available as a</span> |
| 1057 |
01174 <span class="comment">* GNU extension but unavailable to everyone else, so I've opted to</span> |
| 1058 |
01175 <span class="comment">* implement it here. This function is intented to be wrapped by a</span> |
| 1059 |
01176 <span class="comment">* MACRO going by something along the lines of 'xgethostbyname' or</span> |
| 1060 |
01177 <span class="comment">* 'xgethostbyname_r'</span> |
| 1061 |
01178 <span class="comment">*</span> |
| 1062 |
01179 <span class="comment">* Calling function is responsible to call _DNS_gethostbyname_r_free</span> |
| 1063 |
01180 <span class="comment">* to unlock the mutex.</span> |
| 1064 |
01181 <span class="comment">*</span> |
| 1065 |
01182 <span class="comment">*/</span> |
| 1066 |
01183 <span class="keyword">struct </span>hostent *_DNS_gethostbyname_r(<span class="keyword">const</span> <span class="keywordtype">char</span> *name, |
| 1067 |
01184 <span class="keyword">struct</span> hostent *result, <span class="keywordtype">char</span> *buf, <span class="keywordtype">int</span> buf_len, <span class="keywordtype">int</span> *h_errnop) |
| 1068 |
01185 { |
| 1069 |
01186 <span class="keyword">struct </span>hostent *hp; <span class="comment">/* hostent structure */</span> |
| 1070 |
01187 |
| 1071 |
01188 <span class="keywordflow">if</span> (!name) |
| 1072 |
01189 { |
| 1073 |
01190 <a class="code" href="util_8h.html#a13">xepprintf</a>(<span class="stringliteral">"ERROR: No hostname to resolve!\n"</span>); |
| 1074 |
01191 |
| 1075 |
01192 <span class="keywordflow">return</span>(NULL); |
| 1076 |
01193 } |
| 1077 |
01194 |
| 1078 |
01195 <a class="code" href="util_8h.html#a10">xvprintf</a>(<span class="stringliteral">"called with hostname (%s)\n"</span>, name); |
| 1079 |
01196 |
| 1080 |
01197 <a class="code" href="util_8h.html#a14">xpthread_mutex_lock</a>(&dns_mutex); |
| 1081 |
01198 |
| 1082 |
01199 hp = gethostbyname(name); |
| 1083 |
01200 *h_errnop = <a class="code" href="dns_8h.html#a6">h_errno</a>; |
| 1084 |
01201 |
| 1085 |
01202 <a class="code" href="util_8h.html#a11">xpprintf</a>(<span class="stringliteral">"leaving function\n"</span>); |
| 1086 |
01203 |
| 1087 |
01204 <span class="keywordflow">return</span>(hp); |
| 1088 |
01205 } |
| 1089 |
01206 |
| 1090 |
01207 |
| 1091 |
01208 <span class="comment">/* _DNS_gethostbyname_r_free</span> |
| 1092 |
01209 <span class="comment">*</span> |
| 1093 |
01210 <span class="comment">* Author: James Couzens <jcouzens@codeshare.ca></span> |
| 1094 |
01211 <span class="comment">* Date: 08/28/04</span> |
| 1095 |
01212 <span class="comment">*</span> |
| 1096 |
01213 <span class="comment">* Desc:</span> |
| 1097 |
01214 <span class="comment">* This function unlocks the mutex which was locked when</span> |
| 1098 |
01215 <span class="comment">* _DNS_gethostbyname_r was called as a reentrant wrapper around the</span> |
| 1099 |
01216 <span class="comment">* non-threadsafe 'gethostbyname' function call. This function is</span> |
| 1100 |
01217 <span class="comment">* intended to be wrapped by a MACRO going by something along the lines</span> |
| 1101 |
01218 <span class="comment">* of 'xgethostbyname_free' or 'xgethostbyname_r_free'</span> |
| 1102 |
01219 <span class="comment">*</span> |
| 1103 |
01220 <span class="comment">*</span> |
| 1104 |
01221 <span class="comment">*/</span> |
| 1105 |
01222 <span class="keywordtype">void</span> <a class="code" href="dns_8h.html#a7">_DNS_gethostbyname_r_free</a>(<span class="keywordtype">void</span>) |
| 1106 |
01223 { |
| 1107 |
01224 <a class="code" href="util_8h.html#a15">xpthread_mutex_unlock</a>(&dns_mutex); |
| 1108 |
01225 |
| 1109 |
01226 <span class="keywordflow">return</span>; |
| 1110 |
01227 } |
| 1111 |
01228 |
| 1112 |
01229 <span class="preprocessor"> #endif </span><span class="comment">/* HAVE_GETHOSTBYNAME_R */</span> |
| 1113 |
01230 <span class="preprocessor">#endif </span><span class="comment">/* _WITH_PTHREADS */</span> |
| 1114 |
01231 |
| 1115 |
01232 |
| 1116 |
01233 <span class="comment">/* end dns.c */</span> |
| 1117 |
</div></pre><hr size="1"><address style="align: right;"><small>Generated on Thu Sep 16 18:10:46 2004 for libSPF v1.0 by |
| 1118 |
<a href="http://www.doxygen.org/index.html"> |
| 1119 |
<img src="doxygen.png" alt="doxygen" align="middle" border=0 ></a> 1.3.8 </small></address> |
| 1120 |
</body> |
| 1121 |
</html> |
