diff options
Diffstat (limited to 'src/third_party/cares/dist/src/lib/ares__parse_into_addrinfo.c')
| -rw-r--r-- | src/third_party/cares/dist/src/lib/ares__parse_into_addrinfo.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/src/third_party/cares/dist/src/lib/ares__parse_into_addrinfo.c b/src/third_party/cares/dist/src/lib/ares__parse_into_addrinfo.c new file mode 100644 index 00000000000..7550abab4a4 --- /dev/null +++ b/src/third_party/cares/dist/src/lib/ares__parse_into_addrinfo.c @@ -0,0 +1,260 @@ +/* Copyright (C) 2019 by Andrew Selivanov + * + * Permission to use, copy, modify, and distribute this + * software and its documentation for any purpose and without + * fee is hereby granted, provided that the above copyright + * notice appear in all copies and that both that copyright + * notice and this permission notice appear in supporting + * documentation, and that the name of M.I.T. not be used in + * advertising or publicity pertaining to distribution of the + * software without specific, written prior permission. + * M.I.T. makes no representations about the suitability of + * this software for any purpose. It is provided "as is" + * without express or implied warranty. + */ + +#include "ares_setup.h" + +#ifdef HAVE_NETINET_IN_H +# include <netinet/in.h> +#endif +#ifdef HAVE_NETDB_H +# include <netdb.h> +#endif +#ifdef HAVE_ARPA_INET_H +# include <arpa/inet.h> +#endif + +#include "ares_nameser.h" + +#ifdef HAVE_STRINGS_H +# include <strings.h> +#endif + +#ifdef HAVE_LIMITS_H +# include <limits.h> +#endif + +#include "ares.h" +#include "ares_dns.h" +#include "ares_private.h" + +int ares__parse_into_addrinfo2(const unsigned char *abuf, + int alen, + char **question_hostname, + struct ares_addrinfo *ai) +{ + unsigned int qdcount, ancount; + int status, i, rr_type, rr_class, rr_len, rr_ttl; + int got_a = 0, got_aaaa = 0, got_cname = 0; + long len; + const unsigned char *aptr; + char *hostname, *rr_name = NULL, *rr_data; + struct ares_addrinfo_cname *cname, *cnames = NULL; + struct ares_addrinfo_node *node, *nodes = NULL; + struct sockaddr_in *sin; + struct sockaddr_in6 *sin6; + + *question_hostname = NULL; + + /* Give up if abuf doesn't have room for a header. */ + if (alen < HFIXEDSZ) + return ARES_EBADRESP; + + /* Fetch the question and answer count from the header. */ + qdcount = DNS_HEADER_QDCOUNT(abuf); + ancount = DNS_HEADER_ANCOUNT(abuf); + if (qdcount != 1) + return ARES_EBADRESP; + + + /* Expand the name from the question, and skip past the question. */ + aptr = abuf + HFIXEDSZ; + status = ares__expand_name_for_response(aptr, abuf, alen, question_hostname, &len, 0); + if (status != ARES_SUCCESS) + return status; + if (aptr + len + QFIXEDSZ > abuf + alen) + { + return ARES_EBADRESP; + } + + hostname = *question_hostname; + + aptr += len + QFIXEDSZ; + + /* Examine each answer resource record (RR) in turn. */ + for (i = 0; i < (int)ancount; i++) + { + /* Decode the RR up to the data field. */ + status = ares__expand_name_for_response(aptr, abuf, alen, &rr_name, &len, 0); + if (status != ARES_SUCCESS) + { + rr_name = NULL; + goto failed_stat; + } + + aptr += len; + if (aptr + RRFIXEDSZ > abuf + alen) + { + status = ARES_EBADRESP; + goto failed_stat; + } + rr_type = DNS_RR_TYPE(aptr); + rr_class = DNS_RR_CLASS(aptr); + rr_len = DNS_RR_LEN(aptr); + rr_ttl = DNS_RR_TTL(aptr); + aptr += RRFIXEDSZ; + if (aptr + rr_len > abuf + alen) + { + status = ARES_EBADRESP; + goto failed_stat; + } + + if (rr_class == C_IN && rr_type == T_A + && rr_len == sizeof(struct in_addr) + && strcasecmp(rr_name, hostname) == 0) + { + got_a = 1; + if (aptr + sizeof(struct in_addr) > abuf + alen) + { /* LCOV_EXCL_START: already checked above */ + status = ARES_EBADRESP; + goto failed_stat; + } /* LCOV_EXCL_STOP */ + + node = ares__append_addrinfo_node(&nodes); + if (!node) + { + status = ARES_ENOMEM; + goto failed_stat; + } + + sin = ares_malloc(sizeof(struct sockaddr_in)); + if (!sin) + { + status = ARES_ENOMEM; + goto failed_stat; + } + memset(sin, 0, sizeof(struct sockaddr_in)); + memcpy(&sin->sin_addr.s_addr, aptr, sizeof(struct in_addr)); + sin->sin_family = AF_INET; + + node->ai_addr = (struct sockaddr *)sin; + node->ai_family = AF_INET; + node->ai_addrlen = sizeof(struct sockaddr_in); + + node->ai_ttl = rr_ttl; + + status = ARES_SUCCESS; + } + else if (rr_class == C_IN && rr_type == T_AAAA + && rr_len == sizeof(struct ares_in6_addr) + && strcasecmp(rr_name, hostname) == 0) + { + got_aaaa = 1; + if (aptr + sizeof(struct ares_in6_addr) > abuf + alen) + { /* LCOV_EXCL_START: already checked above */ + status = ARES_EBADRESP; + goto failed_stat; + } /* LCOV_EXCL_STOP */ + + node = ares__append_addrinfo_node(&nodes); + if (!node) + { + status = ARES_ENOMEM; + goto failed_stat; + } + + sin6 = ares_malloc(sizeof(struct sockaddr_in6)); + if (!sin6) + { + status = ARES_ENOMEM; + goto failed_stat; + } + + memset(sin6, 0, sizeof(struct sockaddr_in6)); + memcpy(&sin6->sin6_addr.s6_addr, aptr, sizeof(struct ares_in6_addr)); + sin6->sin6_family = AF_INET6; + + node->ai_addr = (struct sockaddr *)sin6; + node->ai_family = AF_INET6; + node->ai_addrlen = sizeof(struct sockaddr_in6); + + node->ai_ttl = rr_ttl; + + status = ARES_SUCCESS; + } + + if (rr_class == C_IN && rr_type == T_CNAME) + { + got_cname = 1; + status = ares__expand_name_for_response(aptr, abuf, alen, &rr_data, + &len, 1); + if (status != ARES_SUCCESS) + { + goto failed_stat; + } + + /* Decode the RR data and replace the hostname with it. */ + /* SA: Seems wrong as it introduses order dependency. */ + hostname = rr_data; + + cname = ares__append_addrinfo_cname(&cnames); + if (!cname) + { + status = ARES_ENOMEM; + ares_free(rr_data); + goto failed_stat; + } + cname->ttl = rr_ttl; + cname->alias = rr_name; + cname->name = rr_data; + } + else + { + ares_free(rr_name); + } + + + aptr += rr_len; + if (aptr > abuf + alen) + { /* LCOV_EXCL_START: already checked above */ + status = ARES_EBADRESP; + goto failed_stat; + } /* LCOV_EXCL_STOP */ + } + + if (status == ARES_SUCCESS) + { + ares__addrinfo_cat_nodes(&ai->nodes, nodes); + if (got_cname) + { + ares__addrinfo_cat_cnames(&ai->cnames, cnames); + return status; + } + else if (got_a == 0 && got_aaaa == 0) + { + /* the check for naliases to be zero is to make sure CNAME responses + don't get caught here */ + status = ARES_ENODATA; + } + } + + return status; + +failed_stat: + ares_free(rr_name); + ares__freeaddrinfo_cnames(cnames); + ares__freeaddrinfo_nodes(nodes); + return status; +} + +int ares__parse_into_addrinfo(const unsigned char *abuf, + int alen, + struct ares_addrinfo *ai) +{ + int status; + char *question_hostname; + status = ares__parse_into_addrinfo2(abuf, alen, &question_hostname, ai); + ares_free(question_hostname); + return status; +} |