diff options
Diffstat (limited to 'src/lib/ares_getaddrinfo.c')
| -rw-r--r-- | src/lib/ares_getaddrinfo.c | 175 |
1 files changed, 98 insertions, 77 deletions
diff --git a/src/lib/ares_getaddrinfo.c b/src/lib/ares_getaddrinfo.c index ecd5dd5..0a0225a 100644 --- a/src/lib/ares_getaddrinfo.c +++ b/src/lib/ares_getaddrinfo.c @@ -34,14 +34,8 @@ #ifdef HAVE_ARPA_INET_H # include <arpa/inet.h> #endif -#ifdef HAVE_ARPA_NAMESER_H -# include <arpa/nameser.h> -#else -# include "nameser.h" -#endif -#ifdef HAVE_ARPA_NAMESER_COMPAT_H -# include <arpa/nameser_compat.h> -#endif + +#include "ares_nameser.h" #ifdef HAVE_STRINGS_H #include <strings.h> @@ -78,6 +72,7 @@ struct host_query struct ares_addrinfo *ai; /* store results between lookups */ int remaining; /* number of DNS answers waiting for */ int next_domain; /* next search domain to try */ + int nodata_cnt; /* Track nodata responses to possibly override final result */ }; static const struct ares_addrinfo_hints default_hints = { @@ -107,13 +102,15 @@ static const struct ares_addrinfo_node empty_addrinfo_node = { static const struct ares_addrinfo empty_addrinfo = { NULL, /* cnames */ - NULL /* nodes */ + NULL, /* nodes */ + NULL /* name */ }; /* forward declarations */ static void host_callback(void *arg, int status, int timeouts, unsigned char *abuf, int alen); static int as_is_first(const struct host_query *hquery); +static int as_is_only(const struct host_query* hquery); static int next_dns_lookup(struct host_query *hquery); struct ares_addrinfo_cname *ares__malloc_addrinfo_cname() @@ -287,9 +284,7 @@ static int fake_addrinfo(const char *name, void *arg) { struct ares_addrinfo_cname *cname; - struct ares_addrinfo_node *node; - ares_sockaddr addr; - size_t addrlen; + int status = ARES_SUCCESS; int result = 0; int family = hints->ai_family; if (family == AF_INET || family == AF_INET6 || family == AF_UNSPEC) @@ -310,62 +305,45 @@ static int fake_addrinfo(const char *name, } } - memset(&addr, 0, sizeof(addr)); - /* if we don't have 3 dots, it is illegal * (although inet_pton doesn't think so). */ if (numdots != 3 || !valid) result = 0; else - result = - (ares_inet_pton(AF_INET, name, &addr.sa4.sin_addr) < 1 ? 0 : 1); - - if (result) { - family = addr.sa.sa_family = AF_INET; - addr.sa4.sin_port = htons(port); - addrlen = sizeof(addr.sa4); + struct in_addr addr4; + result = ares_inet_pton(AF_INET, name, &addr4) < 1 ? 0 : 1; + if (result) + { + status = ares_append_ai_node(AF_INET, port, 0, &addr4, &ai->nodes); + if (status != ARES_SUCCESS) + { + callback(arg, status, 0, NULL); + return 1; + } + } } } if (family == AF_INET6 || family == AF_UNSPEC) { - result = - (ares_inet_pton(AF_INET6, name, &addr.sa6.sin6_addr) < 1 ? 0 : 1); - addr.sa6.sin6_family = AF_INET6; - addr.sa6.sin6_port = htons(port); - addrlen = sizeof(addr.sa6); + struct ares_in6_addr addr6; + result = ares_inet_pton(AF_INET6, name, &addr6) < 1 ? 0 : 1; + if (result) + { + status = ares_append_ai_node(AF_INET6, port, 0, &addr6, &ai->nodes); + if (status != ARES_SUCCESS) + { + callback(arg, status, 0, NULL); + return 1; + } + } } if (!result) return 0; - node = ares__malloc_addrinfo_node(); - if (!node) - { - ares_freeaddrinfo(ai); - callback(arg, ARES_ENOMEM, 0, NULL); - return 1; - } - - ai->nodes = node; - - node->ai_addr = ares_malloc(addrlen); - if (!node->ai_addr) - { - ares_freeaddrinfo(ai); - callback(arg, ARES_ENOMEM, 0, NULL); - return 1; - } - - node->ai_addrlen = (unsigned int)addrlen; - node->ai_family = addr.sa.sa_family; - if (addr.sa.sa_family == AF_INET) - memcpy(node->ai_addr, &addr.sa4, sizeof(addr.sa4)); - else - memcpy(node->ai_addr, &addr.sa6, sizeof(addr.sa6)); - if (hints->ai_flags & ARES_AI_CANONNAME) { cname = ares__append_addrinfo_cname(&ai->cnames); @@ -386,8 +364,8 @@ static int fake_addrinfo(const char *name, } } - node->ai_socktype = hints->ai_socktype; - node->ai_protocol = hints->ai_protocol; + ai->nodes->ai_socktype = hints->ai_socktype; + ai->nodes->ai_protocol = hints->ai_protocol; callback(arg, ARES_SUCCESS, 0, ai); return 1; @@ -399,26 +377,18 @@ static void end_hquery(struct host_query *hquery, int status) struct ares_addrinfo_node *next; if (status == ARES_SUCCESS) { - if (!(hquery->hints.ai_flags & ARES_AI_NOSORT)) + if (!(hquery->hints.ai_flags & ARES_AI_NOSORT) && hquery->ai->nodes) { sentinel.ai_next = hquery->ai->nodes; ares__sortaddrinfo(hquery->channel, &sentinel); hquery->ai->nodes = sentinel.ai_next; } next = hquery->ai->nodes; - /* Set port into each address (resolved separately). */ + while (next) { next->ai_socktype = hquery->hints.ai_socktype; next->ai_protocol = hquery->hints.ai_protocol; - if (next->ai_family == AF_INET) - { - (CARES_INADDR_CAST(struct sockaddr_in *, next->ai_addr))->sin_port = htons(hquery->port); - } - else - { - (CARES_INADDR_CAST(struct sockaddr_in6 *, next->ai_addr))->sin6_port = htons(hquery->port); - } next = next->ai_next; } } @@ -506,6 +476,16 @@ static int file_lookup(struct host_query *hquery) } status = ares__readaddrinfo(fp, hquery->name, hquery->port, &hquery->hints, hquery->ai); fclose(fp); + + /* RFC6761 section 6.3 #3 states that "Name resolution APIs and libraries + * SHOULD recognize localhost names as special and SHOULD always return the + * IP loopback address for address queries" */ + if (status == ARES_ENOTFOUND && strcmp(hquery->name, "localhost") == 0) + { + return ares__addrinfo_localhost(hquery->name, hquery->port, + &hquery->hints, hquery->ai); + } + return status; } @@ -514,9 +494,16 @@ static void next_lookup(struct host_query *hquery, int status) switch (*hquery->remaining_lookups) { case 'b': - /* DNS lookup */ - if (next_dns_lookup(hquery)) - break; + /* RFC6761 section 6.3 #3 says "Name resolution APIs SHOULD NOT send + * queries for localhost names to their configured caching DNS + * server(s)." */ + if (strcmp(hquery->name, "localhost") != 0) + { + /* DNS lookup */ + if (next_dns_lookup(hquery)) + break; + } + hquery->remaining_lookups++; next_lookup(hquery, status); break; @@ -548,17 +535,12 @@ static void host_callback(void *arg, int status, int timeouts, if (status == ARES_SUCCESS) { - addinfostatus = ares__parse_into_addrinfo(abuf, alen, hquery->ai); - } - else if (status == ARES_EDESTRUCTION) - { - end_hquery(hquery, status); - return; + addinfostatus = ares__parse_into_addrinfo(abuf, alen, 1, hquery->port, hquery->ai); } if (!hquery->remaining) { - if (addinfostatus != ARES_SUCCESS) + if (addinfostatus != ARES_SUCCESS && addinfostatus != ARES_ENODATA) { /* error in parsing result e.g. no memory */ end_hquery(hquery, addinfostatus); @@ -568,9 +550,19 @@ static void host_callback(void *arg, int status, int timeouts, /* at least one query ended with ARES_SUCCESS */ end_hquery(hquery, ARES_SUCCESS); } - else if (status == ARES_ENOTFOUND) + else if (status == ARES_ENOTFOUND || status == ARES_ENODATA || + addinfostatus == ARES_ENODATA) { - next_lookup(hquery, status); + if (status == ARES_ENODATA || addinfostatus == ARES_ENODATA) + hquery->nodata_cnt++; + next_lookup(hquery, hquery->nodata_cnt?ARES_ENODATA:status); + } + else if (status == ARES_EDESTRUCTION) + { + /* NOTE: Could also be ARES_EDESTRUCTION. We need to only call this + * once all queries (there can be multiple for getaddrinfo) are + * terminated. */ + end_hquery(hquery, status); } else { @@ -590,6 +582,8 @@ void ares_getaddrinfo(ares_channel channel, unsigned short port = 0; int family; struct ares_addrinfo *ai; + char *alias_name = NULL; + int status; if (!hints) { @@ -614,6 +608,17 @@ void ares_getaddrinfo(ares_channel channel, return; } + /* perform HOSTALIAS resolution (technically this function does some other + * things we are going to ignore) */ + status = ares__single_domain(channel, name, &alias_name); + if (status != ARES_SUCCESS) { + callback(arg, status, 0, NULL); + return; + } + + if (alias_name) + name = alias_name; + if (service) { if (hints->ai_flags & ARES_AI_NUMERICSERV) @@ -621,6 +626,7 @@ void ares_getaddrinfo(ares_channel channel, port = (unsigned short)strtoul(service, NULL, 0); if (!port) { + ares_free(alias_name); callback(arg, ARES_ESERVICE, 0, NULL); return; } @@ -633,6 +639,7 @@ void ares_getaddrinfo(ares_channel channel, port = (unsigned short)strtoul(service, NULL, 0); if (!port) { + ares_free(alias_name); callback(arg, ARES_ESERVICE, 0, NULL); return; } @@ -643,12 +650,14 @@ void ares_getaddrinfo(ares_channel channel, ai = ares__malloc_addrinfo(); if (!ai) { + ares_free(alias_name); callback(arg, ARES_ENOMEM, 0, NULL); return; } if (fake_addrinfo(name, port, hints, ai, callback, arg)) { + ares_free(alias_name); return; } @@ -656,12 +665,14 @@ void ares_getaddrinfo(ares_channel channel, hquery = ares_malloc(sizeof(struct host_query)); if (!hquery) { + ares_free(alias_name); ares_freeaddrinfo(ai); callback(arg, ARES_ENOMEM, 0, NULL); return; } hquery->name = ares_strdup(name); + ares_free(alias_name); if (!hquery->name) { ares_free(hquery); @@ -681,6 +692,7 @@ void ares_getaddrinfo(ares_channel channel, hquery->ai = ai; hquery->next_domain = -1; hquery->remaining = 0; + hquery->nodata_cnt = 0; /* Start performing lookups according to channel->lookups. */ next_lookup(hquery, ARES_ECONNREFUSED /* initial error code */); @@ -711,7 +723,7 @@ static int next_dns_lookup(struct host_query *hquery) hquery->next_domain++; } - if (!s && hquery->next_domain < hquery->channel->ndomains) + if (!s && hquery->next_domain < hquery->channel->ndomains && !as_is_only(hquery)) { status = ares__cat_domain( hquery->name, @@ -759,7 +771,7 @@ static int as_is_first(const struct host_query* hquery) { char* p; int ndots = 0; - size_t nname = strlen(hquery->name); + size_t nname = hquery->name?strlen(hquery->name):0; for (p = hquery->name; *p; p++) { if (*p == '.') @@ -774,3 +786,12 @@ static int as_is_first(const struct host_query* hquery) } return ndots >= hquery->channel->ndots; } + +static int as_is_only(const struct host_query* hquery) +{ + size_t nname = hquery->name?strlen(hquery->name):0; + if (nname && hquery->name[nname-1] == '.') + return 1; + return 0; +} + |