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93 lines
2.4 KiB
93 lines
2.4 KiB
/* libanode: the Anode C reference implementation |
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* Copyright (C) 2009-2010 Adam Ierymenko <adam.ierymenko@gmail.com> |
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* |
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* This program is free software: you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation, either version 3 of the License, or |
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* (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
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#include <stdlib.h> |
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#include <string.h> |
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#include <stdio.h> |
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#include <sys/types.h> |
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#include <sys/socket.h> |
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#include <netinet/in.h> |
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#include <arpa/nameser.h> |
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#include <resolv.h> |
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#include <netdb.h> |
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#include "dns_txt.h" |
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#ifndef C_IN |
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#define C_IN ns_c_in |
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#endif |
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#ifndef T_TXT |
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#define T_TXT ns_t_txt |
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#endif |
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static volatile int Anode_resolver_initialized = 0; |
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int Anode_sync_resolve_txt(const char *host,char *txt,unsigned int txt_len) |
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{ |
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unsigned char answer[16384],*pptr,*end; |
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char name[16384]; |
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int len,explen,i; |
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if (!Anode_resolver_initialized) { |
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Anode_resolver_initialized = 1; |
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res_init(); |
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} |
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/* Do not taunt happy fun ball. */ |
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len = res_search(host,C_IN,T_TXT,answer,sizeof(answer)); |
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if (len > 12) { |
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pptr = answer + 12; |
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end = answer + len; |
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explen = dn_expand(answer,end,pptr,name,sizeof(name)); |
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if (explen > 0) { |
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pptr += explen; |
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if ((pptr + 2) >= end) return 2; |
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if (ntohs(*((uint16_t *)pptr)) == T_TXT) { |
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pptr += 4; |
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if (pptr >= end) return 2; |
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explen = dn_expand(answer,end,pptr,name,sizeof(name)); |
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if (explen > 0) { |
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pptr += explen; |
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if ((pptr + 2) >= end) return 2; |
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if (ntohs(*((uint16_t *)pptr)) == T_TXT) { |
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pptr += 10; |
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if (pptr >= end) return 2; |
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len = *(pptr++); |
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if (len <= 0) return 2; |
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if ((pptr + len) > end) return 2; |
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if (txt_len < (len + 1)) |
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return 4; |
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else { |
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for(i=0;i<len;++i) |
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txt[i] = pptr[i]; |
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txt[len] = (char)0; |
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return 0; |
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} |
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} |
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} |
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} |
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} |
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} |
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return 1; |
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} |
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