/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Copyright (C) 2007 - 2013 Red Hat, Inc. */ #include "libnm-glib-aux/nm-default-glib.h" #include #include #include #include "libnm-glib-aux/nm-logging-syslog.h" #include "nm-dhcp-helper-api.h" /*****************************************************************************/ #if NM_MORE_LOGGING #define _NMLOG_ENABLED(level) TRUE #else #define _NMLOG_ENABLED(level) ((level) <= LOG_ERR) #endif #define _NMLOG(always_enabled, level, ...) \ G_STMT_START \ { \ if ((always_enabled) || _NMLOG_ENABLED(level)) { \ gint64 _tv; \ \ _tv = g_get_real_time(); \ g_print("nm-dhcp-helper[%ld] %-7s [%" G_GINT64_FORMAT \ ".%04d] " _NM_UTILS_MACRO_FIRST(__VA_ARGS__) "\n", \ (long) getpid(), \ nm_utils_syslog_to_str(level), \ (_tv / NM_UTILS_USEC_PER_SEC), \ ((int) ((_tv % NM_UTILS_USEC_PER_SEC) / (((gint64) 100)))) \ _NM_UTILS_MACRO_REST(__VA_ARGS__)); \ } \ } \ G_STMT_END #define _LOGD(...) _NMLOG(TRUE, LOG_INFO, __VA_ARGS__) #define _LOGI(...) _NMLOG(TRUE, LOG_NOTICE, __VA_ARGS__) #define _LOGW(...) _NMLOG(TRUE, LOG_WARNING, __VA_ARGS__) #define _LOGE(...) _NMLOG(TRUE, LOG_ERR, __VA_ARGS__) #define _LOGd(...) _NMLOG(FALSE, LOG_INFO, __VA_ARGS__) #define _LOGi(...) _NMLOG(FALSE, LOG_NOTICE, __VA_ARGS__) #define _LOGw(...) _NMLOG(FALSE, LOG_WARNING, __VA_ARGS__) /*****************************************************************************/ static GVariant * build_signal_parameters(void) { const char *const *environ_iter; GVariantBuilder builder; g_variant_builder_init(&builder, G_VARIANT_TYPE_VARDICT); /* List environment and format for dbus dict */ for (environ_iter = (const char *const *) environ; *environ_iter; environ_iter++) { static const char *const ignore_with_prefix_list[] = {"PATH", "SHLVL", "_", "PWD", "dhc_dbus", NULL}; const char *item = *environ_iter; gs_free char *name = NULL; const char *val; const char *const *p; val = strchr(item, '='); if (!val || item == val) continue; name = g_strndup(item, val - item); val += 1; /* Ignore non-DHCP-related environment variables */ for (p = ignore_with_prefix_list; *p; p++) { if (strncmp(name, *p, strlen(*p)) == 0) goto next; } if (!g_utf8_validate(name, -1, NULL)) continue; /* Value passed as a byte array rather than a string, because there are * no character encoding guarantees with DHCP, and D-Bus requires * strings to be UTF-8. * * Note that we can't use g_variant_new_bytestring() here, because that * includes the trailing '\0'. (??!?) */ g_variant_builder_add(&builder, "{sv}", name, nm_g_variant_new_ay((const guint8 *) val, strlen(val))); next:; } return g_variant_ref_sink(g_variant_new("(a{sv})", &builder)); } int main(int argc, char *argv[]) { gs_unref_object GDBusConnection *connection = NULL; gs_free_error GError *error = NULL; gs_free_error GError *error_flush = NULL; gs_unref_variant GVariant *parameters = NULL; gs_unref_variant GVariant *result = NULL; gs_free char *s_err = NULL; gboolean success; guint try_count; gint64 time_start; gint64 time_end; gint64 remaining_time; gboolean IS_IPv4; const char *reason; /* Connecting to the unix socket can fail with EAGAIN if there are too * many pending connections and the server can't accept them in time * before reaching backlog capacity. Ideally the server should increase * the backlog length, but GLib doesn't provide a way to change it for a * GDBus server. Retry for up to 5 seconds in case of failure. */ time_start = g_get_monotonic_time(); time_end = time_start + (5000 * 1000L); try_count = 0; reason = getenv("reason"); _LOGi("nm-dhcp-helper: event called: %s", reason); IS_IPv4 = !NM_IN_STRSET(reason, "PREINIT6", "BOUND6", "RENEW6", "REBIND6", "DEPREF6", "EXPIRE6", "RELEASE6", "STOP6"); do_connect: try_count++; connection = g_dbus_connection_new_for_address_sync("unix:path=" NMRUNDIR "/private-dhcp", G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT, NULL, NULL, &error); if (!connection) { if (g_error_matches(error, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK)) { remaining_time = time_end - g_get_monotonic_time(); if (remaining_time > 0) { gint64 interval; _LOGi("failure to connect: %s (retry %u, waited %lld ms)", error->message, try_count, (long long) (time_end - remaining_time - time_start) / 1000); interval = NM_CLAMP((gint64) (100L * (1L << NM_MIN(try_count, 31u))), 5000, 100000); g_usleep(NM_MIN(interval, remaining_time)); g_clear_error(&error); goto do_connect; } } g_dbus_error_strip_remote_error(error); _LOGE("could not connect to NetworkManager D-Bus socket: %s", error->message); success = FALSE; goto out; } parameters = build_signal_parameters(); time_end = g_get_monotonic_time() + (200 * 1000L); /* retry for at most 200 milliseconds */ try_count = 0; do_notify: try_count++; result = g_dbus_connection_call_sync(connection, NULL, NM_DHCP_HELPER_SERVER_OBJECT_PATH, NM_DHCP_HELPER_SERVER_INTERFACE_NAME, NM_DHCP_HELPER_SERVER_METHOD_NOTIFY, parameters, NULL, G_DBUS_CALL_FLAGS_NONE, 60000, NULL, &error); if (result) { success = TRUE; goto out; } s_err = g_dbus_error_get_remote_error(error); if (NM_IN_STRSET(s_err, "org.freedesktop.NetworkManager.Device.Failed")) { _LOGi("notify failed with reason: %s", error->message); success = FALSE; goto out; } if (!NM_IN_STRSET(s_err, "org.freedesktop.DBus.Error.UnknownMethod")) { /* Some unexpected error. We treat that as a failure. In particular, * the daemon will fail the request if ACD fails. */ _LOGW("failure to call notify: %s (try signal via Event)", error->message); success = FALSE; goto out; } /* I am not sure that a race can actually happen, as we register the object * on the server side during GDBusServer:new-connection signal. * * However, there was also a race for subscribing to an event, so let's just * do some retry. */ remaining_time = time_end - g_get_monotonic_time(); if (remaining_time > 0) { gint64 interval; _LOGi("failure to call notify: %s (retry %u)", error->message, try_count); interval = NM_CLAMP((gint64) (100L * (1L << NM_MIN(try_count, 31u))), 5000, 25000); g_usleep(NM_MIN(interval, remaining_time)); g_clear_error(&error); goto do_notify; } /* for backward compatibility, try to emit the signal. There is no stable * API between the dhcp-helper and NetworkManager. However, while upgrading * the NetworkManager package, a newer helper might want to notify an * older server, which still uses the "Event". */ _LOGW("failure to call notify: %s (try signal via Event)", error->message); g_clear_error(&error); if (g_dbus_connection_emit_signal(connection, NULL, "/", NM_DHCP_CLIENT_DBUS_IFACE, "Event", parameters, &error)) { /* We were able to send the asynchronous Event. Consider that a success. */ success = TRUE; goto out; } g_dbus_error_strip_remote_error(error); _LOGE("could not send DHCP Event signal: %s", error->message); success = FALSE; out: if (connection && !g_dbus_connection_flush_sync(connection, NULL, &error_flush)) { _LOGE("could not flush D-Bus connection: %s", error_flush->message); /* if we considered this a success so far, don't fail because of this. */ } _LOGi("success: %s", success ? "YES" : "NO"); /* The error code to send a decline depends on the address family */ return success ? EXIT_SUCCESS : (IS_IPv4 ? 1 : 3); }