654 lines
19 KiB
C
654 lines
19 KiB
C
/* SPDX-License-Identifier: LGPL-2.1+ */
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#include <errno.h>
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#include <netdb.h>
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#include <nss.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include "sd-bus.h"
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#include "bus-common-errors.h"
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#include "errno-util.h"
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#include "in-addr-util.h"
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#include "macro.h"
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#include "nss-util.h"
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#include "resolved-def.h"
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#include "signal-util.h"
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#include "string-util.h"
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NSS_GETHOSTBYNAME_PROTOTYPES(resolve);
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NSS_GETHOSTBYADDR_PROTOTYPES(resolve);
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static bool bus_error_shall_fallback(sd_bus_error *e) {
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return sd_bus_error_has_name(e, SD_BUS_ERROR_SERVICE_UNKNOWN) ||
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sd_bus_error_has_name(e, SD_BUS_ERROR_NAME_HAS_NO_OWNER) ||
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sd_bus_error_has_name(e, SD_BUS_ERROR_NO_REPLY) ||
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sd_bus_error_has_name(e, SD_BUS_ERROR_ACCESS_DENIED) ||
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sd_bus_error_has_name(e, SD_BUS_ERROR_DISCONNECTED) ||
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sd_bus_error_has_name(e, SD_BUS_ERROR_TIMEOUT);
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}
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static int count_addresses(sd_bus_message *m, int af, const char **canonical) {
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int c = 0, r;
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assert(m);
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assert(canonical);
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r = sd_bus_message_enter_container(m, 'a', "(iiay)");
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if (r < 0)
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return r;
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while ((r = sd_bus_message_enter_container(m, 'r', "iiay")) > 0) {
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int family, ifindex;
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assert_cc(sizeof(int32_t) == sizeof(int));
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r = sd_bus_message_read(m, "ii", &ifindex, &family);
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if (r < 0)
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return r;
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r = sd_bus_message_skip(m, "ay");
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if (r < 0)
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return r;
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r = sd_bus_message_exit_container(m);
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if (r < 0)
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return r;
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if (af != AF_UNSPEC && family != af)
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continue;
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c++;
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}
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if (r < 0)
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return r;
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r = sd_bus_message_exit_container(m);
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if (r < 0)
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return r;
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r = sd_bus_message_read(m, "s", canonical);
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if (r < 0)
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return r;
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r = sd_bus_message_rewind(m, true);
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if (r < 0)
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return r;
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return c;
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}
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static uint32_t ifindex_to_scopeid(int family, const void *a, int ifindex) {
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struct in6_addr in6;
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if (family != AF_INET6)
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return 0;
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/* Some apps can't deal with the scope ID attached to non-link-local addresses. Hence, let's suppress that. */
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assert(sizeof(in6) == FAMILY_ADDRESS_SIZE(AF_INET6));
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memcpy(&in6, a, sizeof(struct in6_addr));
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return IN6_IS_ADDR_LINKLOCAL(&in6) ? ifindex : 0;
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}
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static bool avoid_deadlock(void) {
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/* Check whether this lookup might have a chance of deadlocking because we are called from the service manager
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* code activating systemd-resolved.service. After all, we shouldn't synchronously do lookups to
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* systemd-resolved if we are required to finish before it can be started. This of course won't detect all
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* possible dead locks of this kind, but it should work for the most obvious cases. */
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if (geteuid() != 0) /* Ignore the env vars unless we are privileged. */
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return false;
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return streq_ptr(getenv("SYSTEMD_ACTIVATION_UNIT"), "systemd-resolved.service") &&
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streq_ptr(getenv("SYSTEMD_ACTIVATION_SCOPE"), "system");
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}
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enum nss_status _nss_resolve_gethostbyname4_r(
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const char *name,
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struct gaih_addrtuple **pat,
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char *buffer, size_t buflen,
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int *errnop, int *h_errnop,
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int32_t *ttlp) {
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_cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL;
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_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
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struct gaih_addrtuple *r_tuple, *r_tuple_first = NULL;
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_cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
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const char *canonical = NULL;
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size_t l, ms, idx;
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char *r_name;
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int c, r, i = 0;
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PROTECT_ERRNO;
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BLOCK_SIGNALS(NSS_SIGNALS_BLOCK);
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assert(name);
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assert(pat);
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assert(buffer);
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assert(errnop);
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assert(h_errnop);
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if (avoid_deadlock()) {
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r = -EDEADLK;
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goto fail;
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}
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r = sd_bus_open_system(&bus);
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if (r < 0)
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goto fail;
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r = sd_bus_message_new_method_call(
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bus,
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&req,
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"org.freedesktop.resolve1",
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"/org/freedesktop/resolve1",
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"org.freedesktop.resolve1.Manager",
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"ResolveHostname");
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if (r < 0)
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goto fail;
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r = sd_bus_message_set_auto_start(req, false);
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if (r < 0)
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goto fail;
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r = sd_bus_message_append(req, "isit", 0, name, AF_UNSPEC, (uint64_t) 0);
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if (r < 0)
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goto fail;
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r = sd_bus_call(bus, req, SD_RESOLVED_QUERY_TIMEOUT_USEC, &error, &reply);
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if (r < 0) {
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if (!bus_error_shall_fallback(&error))
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goto not_found;
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/* Return NSS_STATUS_UNAVAIL when communication with systemd-resolved fails,
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allowing falling back to other nss modules. Treat all other error conditions as
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NOTFOUND. This includes DNSSEC errors and suchlike. (We don't use UNAVAIL in this
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case so that the nsswitch.conf configuration can distinguish such executed but
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negative replies from complete failure to talk to resolved). */
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goto fail;
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}
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c = count_addresses(reply, AF_UNSPEC, &canonical);
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if (c < 0) {
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r = c;
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goto fail;
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}
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if (c == 0)
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goto not_found;
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if (isempty(canonical))
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canonical = name;
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l = strlen(canonical);
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ms = ALIGN(l+1) + ALIGN(sizeof(struct gaih_addrtuple)) * c;
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if (buflen < ms) {
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UNPROTECT_ERRNO;
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*errnop = ERANGE;
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*h_errnop = NETDB_INTERNAL;
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return NSS_STATUS_TRYAGAIN;
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}
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/* First, append name */
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r_name = buffer;
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memcpy(r_name, canonical, l+1);
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idx = ALIGN(l+1);
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/* Second, append addresses */
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r_tuple_first = (struct gaih_addrtuple*) (buffer + idx);
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r = sd_bus_message_enter_container(reply, 'a', "(iiay)");
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if (r < 0)
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goto fail;
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while ((r = sd_bus_message_enter_container(reply, 'r', "iiay")) > 0) {
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int family, ifindex;
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const void *a;
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size_t sz;
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assert_cc(sizeof(int32_t) == sizeof(int));
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r = sd_bus_message_read(reply, "ii", &ifindex, &family);
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if (r < 0)
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goto fail;
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if (ifindex < 0) {
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r = -EINVAL;
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goto fail;
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}
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r = sd_bus_message_read_array(reply, 'y', &a, &sz);
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if (r < 0)
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goto fail;
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r = sd_bus_message_exit_container(reply);
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if (r < 0)
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goto fail;
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if (!IN_SET(family, AF_INET, AF_INET6))
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continue;
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if (sz != FAMILY_ADDRESS_SIZE(family)) {
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r = -EINVAL;
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goto fail;
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}
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r_tuple = (struct gaih_addrtuple*) (buffer + idx);
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r_tuple->next = i == c-1 ? NULL : (struct gaih_addrtuple*) ((char*) r_tuple + ALIGN(sizeof(struct gaih_addrtuple)));
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r_tuple->name = r_name;
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r_tuple->family = family;
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r_tuple->scopeid = ifindex_to_scopeid(family, a, ifindex);
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memcpy(r_tuple->addr, a, sz);
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idx += ALIGN(sizeof(struct gaih_addrtuple));
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i++;
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}
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if (r < 0)
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goto fail;
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assert(i == c);
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assert(idx == ms);
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if (*pat)
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**pat = *r_tuple_first;
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else
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*pat = r_tuple_first;
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if (ttlp)
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*ttlp = 0;
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/* Explicitly reset both *h_errnop and h_errno to work around
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* https://bugzilla.redhat.com/show_bug.cgi?id=1125975 */
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*h_errnop = NETDB_SUCCESS;
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h_errno = 0;
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return NSS_STATUS_SUCCESS;
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fail:
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UNPROTECT_ERRNO;
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*errnop = -r;
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*h_errnop = NO_RECOVERY;
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return NSS_STATUS_UNAVAIL;
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not_found:
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*h_errnop = HOST_NOT_FOUND;
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return NSS_STATUS_NOTFOUND;
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}
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enum nss_status _nss_resolve_gethostbyname3_r(
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const char *name,
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int af,
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struct hostent *result,
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char *buffer, size_t buflen,
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int *errnop, int *h_errnop,
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int32_t *ttlp,
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char **canonp) {
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_cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL;
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_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
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char *r_name, *r_aliases, *r_addr, *r_addr_list;
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_cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
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size_t l, idx, ms, alen;
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const char *canonical;
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int c, r, i = 0;
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PROTECT_ERRNO;
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BLOCK_SIGNALS(NSS_SIGNALS_BLOCK);
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assert(name);
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assert(result);
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assert(buffer);
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assert(errnop);
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assert(h_errnop);
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if (af == AF_UNSPEC)
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af = AF_INET;
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if (!IN_SET(af, AF_INET, AF_INET6)) {
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r = -EAFNOSUPPORT;
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goto fail;
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}
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if (avoid_deadlock()) {
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r = -EDEADLK;
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goto fail;
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}
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r = sd_bus_open_system(&bus);
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if (r < 0)
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goto fail;
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r = sd_bus_message_new_method_call(
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bus,
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&req,
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"org.freedesktop.resolve1",
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"/org/freedesktop/resolve1",
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"org.freedesktop.resolve1.Manager",
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"ResolveHostname");
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if (r < 0)
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goto fail;
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r = sd_bus_message_set_auto_start(req, false);
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if (r < 0)
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goto fail;
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r = sd_bus_message_append(req, "isit", 0, name, af, (uint64_t) 0);
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if (r < 0)
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goto fail;
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r = sd_bus_call(bus, req, SD_RESOLVED_QUERY_TIMEOUT_USEC, &error, &reply);
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if (r < 0) {
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if (!bus_error_shall_fallback(&error))
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goto not_found;
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goto fail;
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}
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c = count_addresses(reply, af, &canonical);
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if (c < 0) {
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r = c;
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goto fail;
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}
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if (c == 0)
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goto not_found;
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if (isempty(canonical))
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canonical = name;
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alen = FAMILY_ADDRESS_SIZE(af);
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l = strlen(canonical);
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ms = ALIGN(l+1) + c * ALIGN(alen) + (c+2) * sizeof(char*);
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if (buflen < ms) {
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UNPROTECT_ERRNO;
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*errnop = ERANGE;
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*h_errnop = NETDB_INTERNAL;
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return NSS_STATUS_TRYAGAIN;
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}
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/* First, append name */
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r_name = buffer;
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memcpy(r_name, canonical, l+1);
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idx = ALIGN(l+1);
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/* Second, create empty aliases array */
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r_aliases = buffer + idx;
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((char**) r_aliases)[0] = NULL;
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idx += sizeof(char*);
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/* Third, append addresses */
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r_addr = buffer + idx;
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r = sd_bus_message_enter_container(reply, 'a', "(iiay)");
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if (r < 0)
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goto fail;
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while ((r = sd_bus_message_enter_container(reply, 'r', "iiay")) > 0) {
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int ifindex, family;
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const void *a;
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size_t sz;
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r = sd_bus_message_read(reply, "ii", &ifindex, &family);
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if (r < 0)
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goto fail;
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if (ifindex < 0) {
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r = -EINVAL;
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goto fail;
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}
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r = sd_bus_message_read_array(reply, 'y', &a, &sz);
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if (r < 0)
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goto fail;
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r = sd_bus_message_exit_container(reply);
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if (r < 0)
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goto fail;
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if (family != af)
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continue;
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if (sz != alen) {
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r = -EINVAL;
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goto fail;
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}
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memcpy(r_addr + i*ALIGN(alen), a, alen);
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i++;
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}
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if (r < 0)
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goto fail;
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assert(i == c);
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idx += c * ALIGN(alen);
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/* Fourth, append address pointer array */
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r_addr_list = buffer + idx;
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for (i = 0; i < c; i++)
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((char**) r_addr_list)[i] = r_addr + i*ALIGN(alen);
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((char**) r_addr_list)[i] = NULL;
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idx += (c+1) * sizeof(char*);
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assert(idx == ms);
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result->h_name = r_name;
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result->h_aliases = (char**) r_aliases;
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result->h_addrtype = af;
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result->h_length = alen;
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result->h_addr_list = (char**) r_addr_list;
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if (ttlp)
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*ttlp = 0;
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if (canonp)
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*canonp = r_name;
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/* Explicitly reset both *h_errnop and h_errno to work around
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* https://bugzilla.redhat.com/show_bug.cgi?id=1125975 */
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*h_errnop = NETDB_SUCCESS;
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h_errno = 0;
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return NSS_STATUS_SUCCESS;
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fail:
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UNPROTECT_ERRNO;
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*errnop = -r;
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*h_errnop = NO_RECOVERY;
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return NSS_STATUS_UNAVAIL;
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not_found:
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*h_errnop = HOST_NOT_FOUND;
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return NSS_STATUS_NOTFOUND;
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}
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enum nss_status _nss_resolve_gethostbyaddr2_r(
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const void* addr, socklen_t len,
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int af,
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struct hostent *result,
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char *buffer, size_t buflen,
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int *errnop, int *h_errnop,
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int32_t *ttlp) {
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_cleanup_(sd_bus_message_unrefp) sd_bus_message *req = NULL, *reply = NULL;
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_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
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char *r_name, *r_aliases, *r_addr, *r_addr_list;
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_cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
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unsigned c = 0, i = 0;
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size_t ms = 0, idx;
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const char *n;
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int r, ifindex;
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PROTECT_ERRNO;
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BLOCK_SIGNALS(NSS_SIGNALS_BLOCK);
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assert(addr);
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assert(result);
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assert(buffer);
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assert(errnop);
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assert(h_errnop);
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if (!IN_SET(af, AF_INET, AF_INET6)) {
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UNPROTECT_ERRNO;
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*errnop = EAFNOSUPPORT;
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*h_errnop = NO_DATA;
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return NSS_STATUS_UNAVAIL;
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}
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if (len != FAMILY_ADDRESS_SIZE(af)) {
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r = -EINVAL;
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goto fail;
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}
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if (avoid_deadlock()) {
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r = -EDEADLK;
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goto fail;
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}
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r = sd_bus_open_system(&bus);
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if (r < 0)
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goto fail;
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r = sd_bus_message_new_method_call(
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bus,
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&req,
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"org.freedesktop.resolve1",
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"/org/freedesktop/resolve1",
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"org.freedesktop.resolve1.Manager",
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"ResolveAddress");
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if (r < 0)
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goto fail;
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r = sd_bus_message_set_auto_start(req, false);
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if (r < 0)
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goto fail;
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r = sd_bus_message_append(req, "ii", 0, af);
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if (r < 0)
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goto fail;
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r = sd_bus_message_append_array(req, 'y', addr, len);
|
|
if (r < 0)
|
|
goto fail;
|
|
|
|
r = sd_bus_message_append(req, "t", (uint64_t) 0);
|
|
if (r < 0)
|
|
goto fail;
|
|
|
|
r = sd_bus_call(bus, req, SD_RESOLVED_QUERY_TIMEOUT_USEC, &error, &reply);
|
|
if (r < 0) {
|
|
if (!bus_error_shall_fallback(&error))
|
|
goto not_found;
|
|
|
|
goto fail;
|
|
}
|
|
|
|
r = sd_bus_message_enter_container(reply, 'a', "(is)");
|
|
if (r < 0)
|
|
goto fail;
|
|
|
|
while ((r = sd_bus_message_read(reply, "(is)", &ifindex, &n)) > 0) {
|
|
|
|
if (ifindex < 0) {
|
|
r = -EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
c++;
|
|
ms += ALIGN(strlen(n) + 1);
|
|
}
|
|
if (r < 0)
|
|
goto fail;
|
|
|
|
r = sd_bus_message_rewind(reply, false);
|
|
if (r < 0)
|
|
goto fail;
|
|
|
|
if (c <= 0)
|
|
goto not_found;
|
|
|
|
ms += ALIGN(len) + /* the address */
|
|
2 * sizeof(char*) + /* pointers to the address, plus trailing NULL */
|
|
c * 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 */
|
|
r_addr = buffer;
|
|
memcpy(r_addr, addr, len);
|
|
idx = ALIGN(len);
|
|
|
|
/* Second, place address list */
|
|
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 */
|
|
r_aliases = buffer + idx;
|
|
idx += sizeof(char*) * c;
|
|
|
|
/* Fourth, place aliases */
|
|
i = 0;
|
|
r_name = buffer + idx;
|
|
while ((r = sd_bus_message_read(reply, "(is)", &ifindex, &n)) > 0) {
|
|
char *p;
|
|
size_t l;
|
|
|
|
l = strlen(n);
|
|
p = buffer + idx;
|
|
memcpy(p, n, l+1);
|
|
|
|
if (i > 0)
|
|
((char**) r_aliases)[i-1] = p;
|
|
i++;
|
|
|
|
idx += ALIGN(l+1);
|
|
}
|
|
if (r < 0)
|
|
goto fail;
|
|
|
|
((char**) r_aliases)[c-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;
|
|
}
|
|
|
|
NSS_GETHOSTBYNAME_FALLBACKS(resolve);
|
|
NSS_GETHOSTBYADDR_FALLBACKS(resolve);
|