diff options
Diffstat (limited to '')
| -rw-r--r-- | src/nss-resolve/nss-resolve.c | 747 |
1 files changed, 747 insertions, 0 deletions
diff --git a/src/nss-resolve/nss-resolve.c b/src/nss-resolve/nss-resolve.c new file mode 100644 index 0000000..0226752 --- /dev/null +++ b/src/nss-resolve/nss-resolve.c @@ -0,0 +1,747 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <netdb.h> +#include <nss.h> +#include <pthread.h> +#include <stdlib.h> +#include <sys/types.h> +#include <unistd.h> + +#include "env-util.h" +#include "errno-util.h" +#include "glyph-util.h" +#include "in-addr-util.h" +#include "macro.h" +#include "nss-util.h" +#include "resolved-def.h" +#include "signal-util.h" +#include "string-util.h" +#include "strv.h" +#include "varlink.h" + +static JsonDispatchFlags json_dispatch_flags = 0; + +static void setup_logging(void) { + log_parse_environment_variables(); + + if (DEBUG_LOGGING) + json_dispatch_flags = JSON_LOG; +} + +static void setup_logging_once(void) { + static pthread_once_t once = PTHREAD_ONCE_INIT; + assert_se(pthread_once(&once, setup_logging) == 0); +} + +#define NSS_ENTRYPOINT_BEGIN \ + BLOCK_SIGNALS(NSS_SIGNALS_BLOCK); \ + setup_logging_once() + +NSS_GETHOSTBYNAME_PROTOTYPES(resolve); +NSS_GETHOSTBYADDR_PROTOTYPES(resolve); + +static bool error_shall_fallback(const char *error_id) { + /* The Varlink errors where we shall signal "please fallback" back to the NSS stack, so that some + * fallback module can be loaded. (These are mostly all Varlink-internal errors, as apparently we + * then were unable to even do IPC with systemd-resolved.) */ + return STR_IN_SET(error_id, + VARLINK_ERROR_DISCONNECTED, + VARLINK_ERROR_TIMEOUT, + VARLINK_ERROR_PROTOCOL, + VARLINK_ERROR_INTERFACE_NOT_FOUND, + VARLINK_ERROR_METHOD_NOT_FOUND, + VARLINK_ERROR_METHOD_NOT_IMPLEMENTED); +} + +static bool error_shall_try_again(const char *error_id) { + /* The Varlink errors where we shall signal "can't answer now but might be able to later" back to the + * NSS stack. These are all errors that indicate lack of configuration or network problems. */ + return STR_IN_SET(error_id, + "io.systemd.Resolve.NoNameServers", + "io.systemd.Resolve.QueryTimedOut", + "io.systemd.Resolve.MaxAttemptsReached", + "io.systemd.Resolve.NetworkDown"); +} + +static int connect_to_resolved(Varlink **ret) { + _cleanup_(varlink_unrefp) Varlink *link = NULL; + int r; + + r = varlink_connect_address(&link, "/run/systemd/resolve/io.systemd.Resolve"); + if (r < 0) + return r; + + r = varlink_set_relative_timeout(link, SD_RESOLVED_QUERY_TIMEOUT_USEC); + if (r < 0) + return r; + + *ret = TAKE_PTR(link); + return 0; +} + +static uint32_t ifindex_to_scopeid(int family, const void *a, int ifindex) { + struct in6_addr in6; + + if (family != AF_INET6 || ifindex == 0) + return 0; + + /* Some apps can't deal with the scope ID attached to non-link-local addresses. Hence, let's suppress that. */ + + assert(sizeof(in6) == FAMILY_ADDRESS_SIZE(AF_INET6)); + memcpy(&in6, a, sizeof(struct in6_addr)); + + return in6_addr_is_link_local(&in6) ? ifindex : 0; +} + +static int json_dispatch_ifindex(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) { + int *ifi = ASSERT_PTR(userdata); + int64_t t; + + assert(variant); + + if (!json_variant_is_integer(variant)) + return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is not an integer.", strna(name)); + + t = json_variant_integer(variant); + if (t > INT_MAX) + return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is out of bounds for an interface index.", strna(name)); + + *ifi = (int) t; + return 0; +} + +static int json_dispatch_family(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) { + int *family = ASSERT_PTR(userdata); + int64_t t; + + assert(variant); + + if (!json_variant_is_integer(variant)) + return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is not an integer.", strna(name)); + + t = json_variant_integer(variant); + if (t < 0 || t > INT_MAX) + return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is not a valid family.", strna(name)); + + *family = (int) t; + return 0; +} + +typedef struct ResolveHostnameReply { + JsonVariant *addresses; + char *name; + uint64_t flags; +} ResolveHostnameReply; + +static void resolve_hostname_reply_destroy(ResolveHostnameReply *p) { + assert(p); + + json_variant_unref(p->addresses); + free(p->name); +} + +static const JsonDispatch resolve_hostname_reply_dispatch_table[] = { + { "addresses", JSON_VARIANT_ARRAY, json_dispatch_variant, offsetof(ResolveHostnameReply, addresses), JSON_MANDATORY }, + { "name", JSON_VARIANT_STRING, json_dispatch_string, offsetof(ResolveHostnameReply, name), 0 }, + { "flags", JSON_VARIANT_UNSIGNED, json_dispatch_uint64, offsetof(ResolveHostnameReply, flags), 0 }, + {} +}; + +typedef struct AddressParameters { + int ifindex; + int family; + union in_addr_union address; + size_t address_size; +} AddressParameters; + +static int json_dispatch_address(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) { + AddressParameters *p = ASSERT_PTR(userdata); + union in_addr_union buf = {}; + JsonVariant *i; + size_t n, k = 0; + + assert(variant); + + if (!json_variant_is_array(variant)) + return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is not an array.", strna(name)); + + n = json_variant_elements(variant); + if (!IN_SET(n, 4, 16)) + return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "JSON field '%s' is array of unexpected size.", strna(name)); + + JSON_VARIANT_ARRAY_FOREACH(i, variant) { + int64_t b; + + if (!json_variant_is_integer(i)) + return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), "Element %zu of JSON field '%s' is not an integer.", k, strna(name)); + + b = json_variant_integer(i); + if (b < 0 || b > 0xff) + return json_log(variant, flags, SYNTHETIC_ERRNO(EINVAL), + "Element %zu of JSON field '%s' is out of range 0%s255.", + k, strna(name), special_glyph(SPECIAL_GLYPH_ELLIPSIS)); + + buf.bytes[k++] = (uint8_t) b; + } + + p->address = buf; + p->address_size = k; + + return 0; +} + +static const JsonDispatch address_parameters_dispatch_table[] = { + { "ifindex", JSON_VARIANT_INTEGER, json_dispatch_ifindex, offsetof(AddressParameters, ifindex), 0 }, + { "family", JSON_VARIANT_INTEGER, json_dispatch_family, offsetof(AddressParameters, family), JSON_MANDATORY }, + { "address", JSON_VARIANT_ARRAY, json_dispatch_address, 0, JSON_MANDATORY }, + {} +}; + +static uint64_t query_flag( + const char *name, + const int value, + uint64_t flag) { + int r; + + r = getenv_bool_secure(name); + if (r >= 0) + return r == value ? flag : 0; + if (r != -ENXIO) + log_debug_errno(r, "Failed to parse $%s, ignoring.", name); + return 0; +} + +static uint64_t query_flags(void) { + /* Allow callers to turn off validation, synthetization, caching, etc., when we resolve via + * nss-resolve. */ + return query_flag("SYSTEMD_NSS_RESOLVE_VALIDATE", 0, SD_RESOLVED_NO_VALIDATE) | + query_flag("SYSTEMD_NSS_RESOLVE_SYNTHESIZE", 0, SD_RESOLVED_NO_SYNTHESIZE) | + query_flag("SYSTEMD_NSS_RESOLVE_CACHE", 0, SD_RESOLVED_NO_CACHE) | + query_flag("SYSTEMD_NSS_RESOLVE_ZONE", 0, SD_RESOLVED_NO_ZONE) | + query_flag("SYSTEMD_NSS_RESOLVE_TRUST_ANCHOR", 0, SD_RESOLVED_NO_TRUST_ANCHOR) | + query_flag("SYSTEMD_NSS_RESOLVE_NETWORK", 0, SD_RESOLVED_NO_NETWORK); +} + +enum nss_status _nss_resolve_gethostbyname4_r( + const char *name, + struct gaih_addrtuple **pat, + char *buffer, size_t buflen, + int *errnop, int *h_errnop, + int32_t *ttlp) { + + _cleanup_(varlink_unrefp) Varlink *link = NULL; + _cleanup_(json_variant_unrefp) JsonVariant *cparams = NULL; + _cleanup_(resolve_hostname_reply_destroy) ResolveHostnameReply p = {}; + JsonVariant *rparams, *entry; + int r; + + PROTECT_ERRNO; + NSS_ENTRYPOINT_BEGIN; + + assert(name); + assert(pat); + assert(buffer); + assert(errnop); + assert(h_errnop); + + r = connect_to_resolved(&link); + if (r < 0) + goto fail; + + r = json_build(&cparams, JSON_BUILD_OBJECT( + JSON_BUILD_PAIR("name", JSON_BUILD_STRING(name)), + JSON_BUILD_PAIR("flags", JSON_BUILD_UNSIGNED(query_flags())))); + if (r < 0) + goto fail; + + /* Return NSS_STATUS_UNAVAIL when communication with systemd-resolved fails, allowing falling + * back to other nss modules. Treat all other error conditions as NOTFOUND. This includes + * DNSSEC errors and suchlike. (We don't use UNAVAIL in this case so that the nsswitch.conf + * configuration can distinguish such executed but negative replies from complete failure to + * talk to resolved). */ + const char *error_id; + r = varlink_call(link, "io.systemd.Resolve.ResolveHostname", cparams, &rparams, &error_id, NULL); + if (r < 0) + goto fail; + if (!isempty(error_id)) { + if (error_shall_try_again(error_id)) + goto try_again; + if (error_shall_fallback(error_id)) + goto fail; + goto not_found; + } + + r = json_dispatch(rparams, resolve_hostname_reply_dispatch_table, NULL, json_dispatch_flags, &p); + if (r < 0) + goto fail; + if (json_variant_is_blank_object(p.addresses)) + goto not_found; + + size_t n_addresses = 0; + JSON_VARIANT_ARRAY_FOREACH(entry, p.addresses) { + AddressParameters q = {}; + + r = json_dispatch(entry, address_parameters_dispatch_table, NULL, json_dispatch_flags, &q); + if (r < 0) + goto fail; + + if (!IN_SET(q.family, AF_INET, AF_INET6)) + continue; + + if (q.address_size != FAMILY_ADDRESS_SIZE(q.family)) { + r = -EINVAL; + goto fail; + } + + n_addresses++; + } + + const char *canonical = p.name ?: name; + size_t l = strlen(canonical); + size_t idx, ms = ALIGN(l+1) + ALIGN(sizeof(struct gaih_addrtuple)) * n_addresses; + + if (buflen < ms) { + UNPROTECT_ERRNO; + *errnop = ERANGE; + *h_errnop = NETDB_INTERNAL; + return NSS_STATUS_TRYAGAIN; + } + + /* First, append name */ + char *r_name = buffer; + memcpy(r_name, canonical, l + 1); + idx = ALIGN(l + 1); + + /* Second, append addresses */ + struct gaih_addrtuple *r_tuple = NULL, + *r_tuple_first = (struct gaih_addrtuple*) (buffer + idx); + + JSON_VARIANT_ARRAY_FOREACH(entry, p.addresses) { + AddressParameters q = {}; + + r = json_dispatch(entry, address_parameters_dispatch_table, NULL, json_dispatch_flags, &q); + if (r < 0) + goto fail; + + if (!IN_SET(q.family, AF_INET, AF_INET6)) + continue; + + r_tuple = (struct gaih_addrtuple*) (buffer + idx); + r_tuple->next = (struct gaih_addrtuple*) ((char*) r_tuple + ALIGN(sizeof(struct gaih_addrtuple))); + r_tuple->name = r_name; + r_tuple->family = q.family; + r_tuple->scopeid = ifindex_to_scopeid(q.family, &q.address, q.ifindex); + memcpy(r_tuple->addr, &q.address, q.address_size); + + idx += ALIGN(sizeof(struct gaih_addrtuple)); + } + + assert(r_tuple); /* We had at least one address, so r_tuple must be set */ + r_tuple->next = NULL; /* Override last next pointer */ + + assert(idx == ms); + + if (*pat) + **pat = *r_tuple_first; + else + *pat = r_tuple_first; + + if (ttlp) + *ttlp = 0; + + /* Explicitly reset both *h_errnop and h_errno to work around + * https://bugzilla.redhat.com/show_bug.cgi?id=1125975 */ + *h_errnop = NETDB_SUCCESS; + h_errno = 0; + + return NSS_STATUS_SUCCESS; + +fail: + UNPROTECT_ERRNO; + *errnop = -r; + *h_errnop = NO_RECOVERY; + return NSS_STATUS_UNAVAIL; + +not_found: + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + +try_again: + UNPROTECT_ERRNO; + *errnop = -r; + *h_errnop = TRY_AGAIN; + return NSS_STATUS_TRYAGAIN; +} + +enum nss_status _nss_resolve_gethostbyname3_r( + const char *name, + int af, + struct hostent *result, + char *buffer, size_t buflen, + int *errnop, int *h_errnop, + int32_t *ttlp, + char **canonp) { + + _cleanup_(varlink_unrefp) Varlink *link = NULL; + _cleanup_(json_variant_unrefp) JsonVariant *cparams = NULL; + _cleanup_(resolve_hostname_reply_destroy) ResolveHostnameReply p = {}; + JsonVariant *rparams, *entry; + int r; + + PROTECT_ERRNO; + NSS_ENTRYPOINT_BEGIN; + + assert(name); + assert(result); + assert(buffer); + assert(errnop); + assert(h_errnop); + + if (af == AF_UNSPEC) + af = AF_INET; + + if (!IN_SET(af, AF_INET, AF_INET6)) { + r = -EAFNOSUPPORT; + goto fail; + } + + r = connect_to_resolved(&link); + if (r < 0) + goto fail; + + r = json_build(&cparams, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("name", JSON_BUILD_STRING(name)), + JSON_BUILD_PAIR("family", JSON_BUILD_INTEGER(af)), + JSON_BUILD_PAIR("flags", JSON_BUILD_UNSIGNED(query_flags())))); + if (r < 0) + goto fail; + + const char *error_id; + r = varlink_call(link, "io.systemd.Resolve.ResolveHostname", cparams, &rparams, &error_id, NULL); + if (r < 0) + goto fail; + if (!isempty(error_id)) { + if (error_shall_try_again(error_id)) + goto try_again; + if (error_shall_fallback(error_id)) + goto fail; + goto not_found; + } + + r = json_dispatch(rparams, resolve_hostname_reply_dispatch_table, NULL, json_dispatch_flags, &p); + if (r < 0) + goto fail; + if (json_variant_is_blank_object(p.addresses)) + goto not_found; + + size_t n_addresses = 0; + JSON_VARIANT_ARRAY_FOREACH(entry, p.addresses) { + AddressParameters q = {}; + + r = json_dispatch(entry, address_parameters_dispatch_table, NULL, json_dispatch_flags, &q); + if (r < 0) + goto fail; + + if (!IN_SET(q.family, AF_INET, AF_INET6)) + continue; + + if (q.address_size != FAMILY_ADDRESS_SIZE(q.family)) { + r = -EINVAL; + goto fail; + } + + n_addresses++; + } + + const char *canonical = p.name ?: name; + + size_t alen = FAMILY_ADDRESS_SIZE(af); + size_t l = strlen(canonical); + + size_t idx, ms = ALIGN(l + 1) + n_addresses * ALIGN(alen) + (n_addresses + 2) * sizeof(char*); + + if (buflen < ms) { + UNPROTECT_ERRNO; + *errnop = ERANGE; + *h_errnop = NETDB_INTERNAL; + return NSS_STATUS_TRYAGAIN; + } + + /* First, append name */ + char *r_name = buffer; + memcpy(r_name, canonical, l+1); + idx = ALIGN(l+1); + + /* Second, create empty aliases array */ + char *r_aliases = buffer + idx; + ((char**) r_aliases)[0] = NULL; + idx += sizeof(char*); + + /* Third, append addresses */ + char *r_addr = buffer + idx; + + size_t i = 0; + JSON_VARIANT_ARRAY_FOREACH(entry, p.addresses) { + AddressParameters q = {}; + + r = json_dispatch(entry, address_parameters_dispatch_table, NULL, json_dispatch_flags, &q); + if (r < 0) + goto fail; + + if (q.family != af) + continue; + + if (q.address_size != alen) { + r = -EINVAL; + goto fail; + } + + memcpy(r_addr + i*ALIGN(alen), &q.address, alen); + i++; + } + + assert(i == n_addresses); + idx += n_addresses * ALIGN(alen); + + /* Fourth, append address pointer array */ + char *r_addr_list = buffer + idx; + for (i = 0; i < n_addresses; i++) + ((char**) r_addr_list)[i] = r_addr + i*ALIGN(alen); + + ((char**) r_addr_list)[i] = NULL; + idx += (n_addresses + 1) * sizeof(char*); + + assert(idx == ms); + + result->h_name = r_name; + result->h_aliases = (char**) r_aliases; + result->h_addrtype = af; + result->h_length = alen; + result->h_addr_list = (char**) r_addr_list; + + if (ttlp) + *ttlp = 0; + + if (canonp) + *canonp = r_name; + + /* Explicitly reset both *h_errnop and h_errno to work around + * https://bugzilla.redhat.com/show_bug.cgi?id=1125975 */ + *h_errnop = NETDB_SUCCESS; + h_errno = 0; + + return NSS_STATUS_SUCCESS; + +fail: + UNPROTECT_ERRNO; + *errnop = -r; + *h_errnop = NO_RECOVERY; + return NSS_STATUS_UNAVAIL; + +not_found: + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + +try_again: + UNPROTECT_ERRNO; + *errnop = -r; + *h_errnop = TRY_AGAIN; + return NSS_STATUS_TRYAGAIN; +} + +typedef struct ResolveAddressReply { + JsonVariant *names; + uint64_t flags; +} ResolveAddressReply; + +static void resolve_address_reply_destroy(ResolveAddressReply *p) { + assert(p); + + json_variant_unref(p->names); +} + +static const JsonDispatch resolve_address_reply_dispatch_table[] = { + { "names", JSON_VARIANT_ARRAY, json_dispatch_variant, offsetof(ResolveAddressReply, names), JSON_MANDATORY }, + { "flags", JSON_VARIANT_UNSIGNED, json_dispatch_uint64, offsetof(ResolveAddressReply, flags), 0 }, + {} +}; + +typedef struct NameParameters { + int ifindex; + char *name; +} NameParameters; + +static void name_parameters_destroy(NameParameters *p) { + assert(p); + + free(p->name); +} + +static const JsonDispatch name_parameters_dispatch_table[] = { + { "ifindex", JSON_VARIANT_INTEGER, json_dispatch_ifindex, offsetof(NameParameters, ifindex), 0 }, + { "name", JSON_VARIANT_STRING, json_dispatch_string, offsetof(NameParameters, name), JSON_MANDATORY }, + {} +}; + +enum nss_status _nss_resolve_gethostbyaddr2_r( + const void* addr, socklen_t len, + int af, + struct hostent *result, + char *buffer, size_t buflen, + int *errnop, int *h_errnop, + int32_t *ttlp) { + + _cleanup_(varlink_unrefp) Varlink *link = NULL; + _cleanup_(json_variant_unrefp) JsonVariant *cparams = NULL; + _cleanup_(resolve_address_reply_destroy) ResolveAddressReply p = {}; + JsonVariant *rparams, *entry; + int r; + + PROTECT_ERRNO; + NSS_ENTRYPOINT_BEGIN; + + assert(addr); + assert(result); + assert(buffer); + assert(errnop); + assert(h_errnop); + + if (!IN_SET(af, AF_INET, AF_INET6)) { + UNPROTECT_ERRNO; + *errnop = EAFNOSUPPORT; + *h_errnop = NO_DATA; + return NSS_STATUS_UNAVAIL; + } + + if (len != FAMILY_ADDRESS_SIZE(af)) { + r = -EINVAL; + goto fail; + } + + r = connect_to_resolved(&link); + if (r < 0) + goto fail; + + r = json_build(&cparams, JSON_BUILD_OBJECT(JSON_BUILD_PAIR("address", JSON_BUILD_BYTE_ARRAY(addr, len)), + JSON_BUILD_PAIR("family", JSON_BUILD_INTEGER(af)), + JSON_BUILD_PAIR("flags", JSON_BUILD_UNSIGNED(query_flags())))); + if (r < 0) + goto fail; + + const char* error_id; + r = varlink_call(link, "io.systemd.Resolve.ResolveAddress", cparams, &rparams, &error_id, NULL); + if (r < 0) + goto fail; + if (!isempty(error_id)) { + if (error_shall_try_again(error_id)) + goto try_again; + if (error_shall_fallback(error_id)) + goto fail; + goto not_found; + } + + r = json_dispatch(rparams, resolve_address_reply_dispatch_table, NULL, json_dispatch_flags, &p); + if (r < 0) + goto fail; + if (json_variant_is_blank_object(p.names)) + goto not_found; + + size_t ms = 0, idx; + + JSON_VARIANT_ARRAY_FOREACH(entry, p.names) { + _cleanup_(name_parameters_destroy) NameParameters q = {}; + + r = json_dispatch(entry, name_parameters_dispatch_table, NULL, json_dispatch_flags, &q); + if (r < 0) + goto fail; + + ms += ALIGN(strlen(q.name) + 1); + } + + size_t n_names = json_variant_elements(p.names); + ms += ALIGN(len) + /* the address */ + 2 * sizeof(char*) + /* pointer to the address, plus trailing NULL */ + n_names * sizeof(char*); /* pointers to aliases, plus trailing NULL */ + + if (buflen < ms) { + UNPROTECT_ERRNO; + *errnop = ERANGE; + *h_errnop = NETDB_INTERNAL; + return NSS_STATUS_TRYAGAIN; + } + + /* First, place address */ + char *r_addr = buffer; + memcpy(r_addr, addr, len); + idx = ALIGN(len); + + /* Second, place address list */ + char *r_addr_list = buffer + idx; + ((char**) r_addr_list)[0] = r_addr; + ((char**) r_addr_list)[1] = NULL; + idx += sizeof(char*) * 2; + + /* Third, reserve space for the aliases array, plus trailing NULL */ + char *r_aliases = buffer + idx; + idx += sizeof(char*) * n_names; + + /* Fourth, place aliases */ + char *r_name = buffer + idx; + + size_t i = 0; + JSON_VARIANT_ARRAY_FOREACH(entry, p.names) { + _cleanup_(name_parameters_destroy) NameParameters q = {}; + + r = json_dispatch(entry, name_parameters_dispatch_table, NULL, json_dispatch_flags, &q); + if (r < 0) + goto fail; + + size_t l = strlen(q.name); + char *z = buffer + idx; + memcpy(z, q.name, l + 1); + + if (i > 0) + ((char**) r_aliases)[i - 1] = z; + i++; + + idx += ALIGN(l + 1); + } + ((char**) r_aliases)[n_names - 1] = NULL; + + assert(idx == ms); + + result->h_name = r_name; + result->h_aliases = (char**) r_aliases; + result->h_addrtype = af; + result->h_length = len; + result->h_addr_list = (char**) r_addr_list; + + if (ttlp) + *ttlp = 0; + + /* Explicitly reset both *h_errnop and h_errno to work around + * https://bugzilla.redhat.com/show_bug.cgi?id=1125975 */ + *h_errnop = NETDB_SUCCESS; + h_errno = 0; + + return NSS_STATUS_SUCCESS; + +fail: + UNPROTECT_ERRNO; + *errnop = -r; + *h_errnop = NO_RECOVERY; + return NSS_STATUS_UNAVAIL; + +not_found: + *h_errnop = HOST_NOT_FOUND; + return NSS_STATUS_NOTFOUND; + +try_again: + UNPROTECT_ERRNO; + *errnop = -r; + *h_errnop = TRY_AGAIN; + return NSS_STATUS_TRYAGAIN; +} + +NSS_GETHOSTBYNAME_FALLBACKS(resolve); +NSS_GETHOSTBYADDR_FALLBACKS(resolve); |