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-rw-r--r--src/nss-mymachines/nss-mymachines.c440
-rw-r--r--src/nss-mymachines/nss-mymachines.sym21
2 files changed, 461 insertions, 0 deletions
diff --git a/src/nss-mymachines/nss-mymachines.c b/src/nss-mymachines/nss-mymachines.c
new file mode 100644
index 0000000..c64e79b
--- /dev/null
+++ b/src/nss-mymachines/nss-mymachines.c
@@ -0,0 +1,440 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <netdb.h>
+#include <nss.h>
+#include <pthread.h>
+
+#include "sd-bus.h"
+#include "sd-login.h"
+
+#include "alloc-util.h"
+#include "bus-common-errors.h"
+#include "bus-locator.h"
+#include "env-util.h"
+#include "errno-util.h"
+#include "format-util.h"
+#include "hostname-util.h"
+#include "in-addr-util.h"
+#include "log.h"
+#include "macro.h"
+#include "memory-util.h"
+#include "nss-util.h"
+#include "signal-util.h"
+#include "string-util.h"
+
+static void setup_logging_once(void) {
+ static pthread_once_t once = PTHREAD_ONCE_INIT;
+ assert_se(pthread_once(&once, log_parse_environment_variables) == 0);
+}
+
+#define NSS_ENTRYPOINT_BEGIN \
+ BLOCK_SIGNALS(NSS_SIGNALS_BLOCK); \
+ setup_logging_once()
+
+NSS_GETHOSTBYNAME_PROTOTYPES(mymachines);
+NSS_GETPW_PROTOTYPES(mymachines);
+NSS_GETGR_PROTOTYPES(mymachines);
+
+static int count_addresses(sd_bus_message *m, int af, unsigned *ret) {
+ unsigned c = 0;
+ int r;
+
+ assert(m);
+ assert(ret);
+
+ while ((r = sd_bus_message_enter_container(m, 'r', "iay")) > 0) {
+ int family;
+
+ r = sd_bus_message_read(m, "i", &family);
+ if (r < 0)
+ return r;
+
+ r = sd_bus_message_skip(m, "ay");
+ if (r < 0)
+ return r;
+
+ r = sd_bus_message_exit_container(m);
+ if (r < 0)
+ return r;
+
+ if (af != AF_UNSPEC && family != af)
+ continue;
+
+ c++;
+ }
+ if (r < 0)
+ return r;
+
+ r = sd_bus_message_rewind(m, false);
+ if (r < 0)
+ return r;
+
+ *ret = c;
+ return 0;
+}
+
+static bool avoid_deadlock(void) {
+
+ /* Check whether this lookup might have a chance of deadlocking because we are called from the service manager
+ * code activating systemd-machined.service. After all, we shouldn't synchronously do lookups to
+ * systemd-machined if we are required to finish before it can be started. This of course won't detect all
+ * possible dead locks of this kind, but it should work for the most obvious cases. */
+
+ if (geteuid() != 0) /* Ignore the env vars unless we are privileged. */
+ return false;
+
+ return streq_ptr(getenv("SYSTEMD_ACTIVATION_UNIT"), "systemd-machined.service") &&
+ streq_ptr(getenv("SYSTEMD_ACTIVATION_SCOPE"), "system");
+}
+
+enum nss_status _nss_mymachines_gethostbyname4_r(
+ const char *name,
+ struct gaih_addrtuple **pat,
+ char *buffer, size_t buflen,
+ int *errnop, int *h_errnop,
+ int32_t *ttlp) {
+
+ struct gaih_addrtuple *r_tuple, *r_tuple_first = NULL;
+ _cleanup_(sd_bus_message_unrefp) sd_bus_message* reply = NULL;
+ _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+ _cleanup_free_ int *ifindices = NULL;
+ _cleanup_free_ char *class = NULL;
+ size_t l, ms, idx;
+ unsigned i = 0, c = 0;
+ char *r_name;
+ int n_ifindices, r;
+
+ PROTECT_ERRNO;
+ NSS_ENTRYPOINT_BEGIN;
+
+ assert(name);
+ assert(pat);
+ assert(buffer);
+ assert(errnop);
+ assert(h_errnop);
+
+ r = sd_machine_get_class(name, &class);
+ if (r < 0)
+ goto fail;
+ if (!streq(class, "container")) {
+ r = -ENOTTY;
+ goto fail;
+ }
+
+ n_ifindices = sd_machine_get_ifindices(name, &ifindices);
+ if (n_ifindices < 0) {
+ r = n_ifindices;
+ goto fail;
+ }
+
+ if (avoid_deadlock()) {
+ r = -EDEADLK;
+ goto fail;
+ }
+
+ r = sd_bus_open_system(&bus);
+ if (r < 0)
+ goto fail;
+
+ r = bus_call_method(bus, bus_machine_mgr, "GetMachineAddresses", NULL, &reply, "s", name);
+ if (r < 0)
+ goto fail;
+
+ r = sd_bus_message_enter_container(reply, 'a', "(iay)");
+ if (r < 0)
+ goto fail;
+
+ r = count_addresses(reply, AF_UNSPEC, &c);
+ if (r < 0)
+ goto fail;
+
+ if (c <= 0) {
+ *h_errnop = HOST_NOT_FOUND;
+ return NSS_STATUS_NOTFOUND;
+ }
+
+ l = strlen(name);
+ ms = ALIGN(l+1) + ALIGN(sizeof(struct gaih_addrtuple)) * c;
+ if (buflen < ms) {
+ UNPROTECT_ERRNO;
+ *errnop = ERANGE;
+ *h_errnop = NETDB_INTERNAL;
+ return NSS_STATUS_TRYAGAIN;
+ }
+
+ /* First, append name */
+ r_name = buffer;
+ memcpy(r_name, name, l+1);
+ idx = ALIGN(l+1);
+
+ /* Second, append addresses */
+ r_tuple_first = (struct gaih_addrtuple*) (buffer + idx);
+ while ((r = sd_bus_message_enter_container(reply, 'r', "iay")) > 0) {
+ int family;
+ const void *a;
+ size_t sz;
+
+ r = sd_bus_message_read(reply, "i", &family);
+ if (r < 0)
+ goto fail;
+
+ r = sd_bus_message_read_array(reply, 'y', &a, &sz);
+ if (r < 0)
+ goto fail;
+
+ r = sd_bus_message_exit_container(reply);
+ if (r < 0)
+ goto fail;
+
+ if (!IN_SET(family, AF_INET, AF_INET6)) {
+ r = -EAFNOSUPPORT;
+ goto fail;
+ }
+
+ if (sz != FAMILY_ADDRESS_SIZE(family)) {
+ r = -EINVAL;
+ goto fail;
+ }
+
+ r_tuple = (struct gaih_addrtuple*) (buffer + idx);
+ r_tuple->next = i == c-1 ? NULL : (struct gaih_addrtuple*) ((char*) r_tuple + ALIGN(sizeof(struct gaih_addrtuple)));
+ r_tuple->name = r_name;
+ r_tuple->family = family;
+ r_tuple->scopeid = n_ifindices == 1 ? ifindices[0] : 0;
+ memcpy(r_tuple->addr, a, sz);
+
+ idx += ALIGN(sizeof(struct gaih_addrtuple));
+ i++;
+ }
+
+ assert(i == c);
+
+ r = sd_bus_message_exit_container(reply);
+ if (r < 0)
+ goto fail;
+
+ 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;
+}
+
+enum nss_status _nss_mymachines_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_(sd_bus_message_unrefp) sd_bus_message* reply = NULL;
+ _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+ _cleanup_free_ char *class = NULL;
+ unsigned c = 0, i = 0;
+ char *r_name, *r_aliases, *r_addr, *r_addr_list;
+ size_t l, idx, ms, alen;
+ 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 (af != AF_INET && af != AF_INET6) {
+ r = -EAFNOSUPPORT;
+ goto fail;
+ }
+
+ r = sd_machine_get_class(name, &class);
+ if (r < 0)
+ goto fail;
+ if (!streq(class, "container")) {
+ r = -ENOTTY;
+ goto fail;
+ }
+
+ if (avoid_deadlock()) {
+ r = -EDEADLK;
+ goto fail;
+ }
+
+ r = sd_bus_open_system(&bus);
+ if (r < 0)
+ goto fail;
+
+ r = bus_call_method(bus, bus_machine_mgr, "GetMachineAddresses", NULL, &reply, "s", name);
+ if (r < 0)
+ goto fail;
+
+ r = sd_bus_message_enter_container(reply, 'a', "(iay)");
+ if (r < 0)
+ goto fail;
+
+ r = count_addresses(reply, af, &c);
+ if (r < 0)
+ goto fail;
+
+ if (c <= 0) {
+ *h_errnop = HOST_NOT_FOUND;
+ return NSS_STATUS_NOTFOUND;
+ }
+
+ alen = FAMILY_ADDRESS_SIZE(af);
+ l = strlen(name);
+
+ ms = ALIGN(l+1) + c * ALIGN(alen) + (c+2) * sizeof(char*);
+
+ if (buflen < ms) {
+ UNPROTECT_ERRNO;
+ *errnop = ERANGE;
+ *h_errnop = NETDB_INTERNAL;
+ return NSS_STATUS_TRYAGAIN;
+ }
+
+ /* First, append name */
+ r_name = buffer;
+ memcpy(r_name, name, l+1);
+ idx = ALIGN(l+1);
+
+ /* Second, create aliases array */
+ r_aliases = buffer + idx;
+ ((char**) r_aliases)[0] = NULL;
+ idx += sizeof(char*);
+
+ /* Third, append addresses */
+ r_addr = buffer + idx;
+ while ((r = sd_bus_message_enter_container(reply, 'r', "iay")) > 0) {
+ int family;
+ const void *a;
+ size_t sz;
+
+ r = sd_bus_message_read(reply, "i", &family);
+ if (r < 0)
+ goto fail;
+
+ r = sd_bus_message_read_array(reply, 'y', &a, &sz);
+ if (r < 0)
+ goto fail;
+
+ r = sd_bus_message_exit_container(reply);
+ if (r < 0)
+ goto fail;
+
+ if (family != af)
+ continue;
+
+ if (sz != alen) {
+ r = -EINVAL;
+ goto fail;
+ }
+
+ memcpy(r_addr + i*ALIGN(alen), a, alen);
+ i++;
+ }
+
+ assert(i == c);
+ idx += c * ALIGN(alen);
+
+ r = sd_bus_message_exit_container(reply);
+ if (r < 0)
+ goto fail;
+
+ /* Third, append address pointer array */
+ r_addr_list = buffer + idx;
+ for (i = 0; i < c; i++)
+ ((char**) r_addr_list)[i] = r_addr + i*ALIGN(alen);
+
+ ((char**) r_addr_list)[i] = NULL;
+ idx += (c+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;
+}
+
+NSS_GETHOSTBYNAME_FALLBACKS(mymachines);
+
+enum nss_status _nss_mymachines_getpwnam_r(
+ const char *name,
+ struct passwd *pwd,
+ char *buffer, size_t buflen,
+ int *errnop) {
+
+ return NSS_STATUS_NOTFOUND;
+}
+
+enum nss_status _nss_mymachines_getpwuid_r(
+ uid_t uid,
+ struct passwd *pwd,
+ char *buffer, size_t buflen,
+ int *errnop) {
+
+ return NSS_STATUS_NOTFOUND;
+}
+
+enum nss_status _nss_mymachines_getgrnam_r(
+ const char *name,
+ struct group *gr,
+ char *buffer, size_t buflen,
+ int *errnop) {
+
+ return NSS_STATUS_NOTFOUND;
+}
+
+enum nss_status _nss_mymachines_getgrgid_r(
+ gid_t gid,
+ struct group *gr,
+ char *buffer, size_t buflen,
+ int *errnop) {
+
+ return NSS_STATUS_NOTFOUND;
+}
diff --git a/src/nss-mymachines/nss-mymachines.sym b/src/nss-mymachines/nss-mymachines.sym
new file mode 100644
index 0000000..258244e
--- /dev/null
+++ b/src/nss-mymachines/nss-mymachines.sym
@@ -0,0 +1,21 @@
+/***
+ SPDX-License-Identifier: LGPL-2.1-or-later
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+***/
+
+{
+global:
+ _nss_mymachines_gethostbyname_r;
+ _nss_mymachines_gethostbyname2_r;
+ _nss_mymachines_gethostbyname3_r;
+ _nss_mymachines_gethostbyname4_r;
+ _nss_mymachines_getpwnam_r;
+ _nss_mymachines_getpwuid_r;
+ _nss_mymachines_getgrnam_r;
+ _nss_mymachines_getgrgid_r;
+local: *;
+};
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