mirror of https://github.com/c-ares/c-ares.git
first little steps towards IPv6 support!pull/1/head
Daniel Stenberg
20 years ago
parent
9898493661
commit
9586905220
7 changed files with 283 additions and 6 deletions
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/* Copyright 2005 Dominick Meglio
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* |
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* Permission to use, copy, modify, and distribute this |
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* software and its documentation for any purpose and without |
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* fee is hereby granted, provided that the above copyright |
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* notice appear in all copies and that both that copyright |
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* notice and this permission notice appear in supporting |
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* documentation, and that the name of M.I.T. not be used in |
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* advertising or publicity pertaining to distribution of the |
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* software without specific, written prior permission. |
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* M.I.T. makes no representations about the suitability of |
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* this software for any purpose. It is provided "as is" |
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* without express or implied warranty. |
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*/ |
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#include "setup.h" |
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#include <sys/types.h> |
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#if defined(WIN32) && !defined(WATT32) |
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#include "nameser.h" |
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#else |
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#include <sys/socket.h> |
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#include <netinet/in.h> |
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#include <arpa/inet.h> |
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#include <netdb.h> |
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#include <arpa/nameser.h> |
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#endif |
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#include <stdlib.h> |
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#include <string.h> |
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#include "ares.h" |
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#include "ares_dns.h" |
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#include "ares_private.h" |
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int ares_parse_aaaa_reply(const unsigned char *abuf, int alen, |
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struct hostent **host) |
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{ |
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unsigned int qdcount, ancount; |
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int status, i, rr_type, rr_class, rr_len, naddrs; |
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int naliases; |
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long len; |
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const unsigned char *aptr; |
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char *hostname, *rr_name, *rr_data, **aliases; |
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struct in6_addr *addrs; |
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struct hostent *hostent; |
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/* Set *host to NULL for all failure cases. */ |
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*host = NULL; |
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/* Give up if abuf doesn't have room for a header. */ |
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if (alen < HFIXEDSZ) |
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return ARES_EBADRESP; |
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/* Fetch the question and answer count from the header. */ |
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qdcount = DNS_HEADER_QDCOUNT(abuf); |
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ancount = DNS_HEADER_ANCOUNT(abuf); |
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if (qdcount != 1) |
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return ARES_EBADRESP; |
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/* Expand the name from the question, and skip past the question. */ |
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aptr = abuf + HFIXEDSZ; |
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status = ares_expand_name(aptr, abuf, alen, &hostname, &len); |
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if (status != ARES_SUCCESS) |
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return status; |
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if (aptr + len + QFIXEDSZ > abuf + alen) |
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{ |
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free(hostname); |
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return ARES_EBADRESP; |
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} |
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aptr += len + QFIXEDSZ; |
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/* Allocate addresses and aliases; ancount gives an upper bound for both. */ |
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addrs = malloc(ancount * sizeof(struct in6_addr)); |
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if (!addrs) |
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{ |
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free(hostname); |
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return ARES_ENOMEM; |
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} |
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aliases = malloc((ancount + 1) * sizeof(char *)); |
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if (!aliases) |
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{ |
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free(hostname); |
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free(addrs); |
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return ARES_ENOMEM; |
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} |
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naddrs = 0; |
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naliases = 0; |
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/* Examine each answer resource record (RR) in turn. */ |
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for (i = 0; i < (int)ancount; i++) |
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{ |
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/* Decode the RR up to the data field. */ |
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status = ares_expand_name(aptr, abuf, alen, &rr_name, &len); |
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if (status != ARES_SUCCESS) |
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break; |
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aptr += len; |
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if (aptr + RRFIXEDSZ > abuf + alen) |
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{ |
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status = ARES_EBADRESP; |
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break; |
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} |
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rr_type = DNS_RR_TYPE(aptr); |
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rr_class = DNS_RR_CLASS(aptr); |
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rr_len = DNS_RR_LEN(aptr); |
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aptr += RRFIXEDSZ; |
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if (rr_class == C_IN && rr_type == T_AAAA |
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&& rr_len == sizeof(struct in6_addr) |
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&& strcasecmp(rr_name, hostname) == 0) |
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{ |
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memcpy(&addrs[naddrs], aptr, sizeof(struct in6_addr)); |
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naddrs++; |
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status = ARES_SUCCESS; |
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} |
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if (rr_class == C_IN && rr_type == T_CNAME) |
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{ |
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/* Record the RR name as an alias. */ |
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aliases[naliases] = rr_name; |
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naliases++; |
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/* Decode the RR data and replace the hostname with it. */ |
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status = ares_expand_name(aptr, abuf, alen, &rr_data, &len); |
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if (status != ARES_SUCCESS) |
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break; |
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free(hostname); |
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hostname = rr_data; |
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} |
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else |
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free(rr_name); |
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aptr += rr_len; |
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if (aptr > abuf + alen) |
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{ |
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status = ARES_EBADRESP; |
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break; |
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} |
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} |
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if (status == ARES_SUCCESS && naddrs == 0) |
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status = ARES_ENODATA; |
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if (status == ARES_SUCCESS) |
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{ |
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/* We got our answer. Allocate memory to build the host entry. */ |
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aliases[naliases] = NULL; |
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hostent = malloc(sizeof(struct hostent)); |
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if (hostent) |
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{ |
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hostent->h_addr_list = malloc((naddrs + 1) * sizeof(char *)); |
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if (hostent->h_addr_list) |
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{ |
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/* Fill in the hostent and return successfully. */ |
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hostent->h_name = hostname; |
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hostent->h_aliases = aliases; |
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hostent->h_addrtype = AF_INET6; |
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hostent->h_length = sizeof(struct in6_addr); |
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for (i = 0; i < naddrs; i++) |
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hostent->h_addr_list[i] = (char *) &addrs[i]; |
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hostent->h_addr_list[naddrs] = NULL; |
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*host = hostent; |
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return ARES_SUCCESS; |
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} |
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free(hostent); |
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} |
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status = ARES_ENOMEM; |
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} |
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for (i = 0; i < naliases; i++) |
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free(aliases[i]); |
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free(aliases); |
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free(addrs); |
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free(hostname); |
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return status; |
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} |
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