diff options
Diffstat (limited to 'src/core/dnsmasq/nm-dnsmasq-manager.c')
| -rw-r--r-- | src/core/dnsmasq/nm-dnsmasq-manager.c | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/src/core/dnsmasq/nm-dnsmasq-manager.c b/src/core/dnsmasq/nm-dnsmasq-manager.c new file mode 100644 index 0000000000..00b02a05aa --- /dev/null +++ b/src/core/dnsmasq/nm-dnsmasq-manager.c @@ -0,0 +1,355 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2008 - 2012 Red Hat, Inc. + */ + +#include "nm-default.h" + +#include "nm-dnsmasq-manager.h" + +#include <sys/types.h> +#include <sys/wait.h> +#include <signal.h> +#include <unistd.h> +#include <arpa/inet.h> +#include <stdlib.h> + +#include "nm-dnsmasq-utils.h" +#include "nm-utils.h" +#include "NetworkManagerUtils.h" +#include "nm-core-internal.h" + +#define CONFDIR NMCONFDIR "/dnsmasq-shared.d" + +/*****************************************************************************/ + +enum { + STATE_CHANGED, + LAST_SIGNAL, +}; + +static guint signals[LAST_SIGNAL] = {0}; + +typedef struct { + char *iface; + char *pidfile; + GPid pid; + guint dm_watch_id; +} NMDnsMasqManagerPrivate; + +struct _NMDnsMasqManager { + GObject parent; + NMDnsMasqManagerPrivate _priv; +}; + +struct _NMDnsMasqManagerClass { + GObjectClass parent; +}; + +G_DEFINE_TYPE(NMDnsMasqManager, nm_dnsmasq_manager, G_TYPE_OBJECT) + +#define NM_DNSMASQ_MANAGER_GET_PRIVATE(self) \ + _NM_GET_PRIVATE(self, NMDnsMasqManager, NM_IS_DNSMASQ_MANAGER) + +/*****************************************************************************/ + +#define _NMLOG_DOMAIN LOGD_SHARING +#define _NMLOG(level, ...) __NMLOG_DEFAULT(level, _NMLOG_DOMAIN, "dnsmasq-manager", __VA_ARGS__) + +/*****************************************************************************/ + +static void +dm_watch_cb(GPid pid, int status, gpointer user_data) +{ + NMDnsMasqManager * manager = NM_DNSMASQ_MANAGER(user_data); + NMDnsMasqManagerPrivate *priv = NM_DNSMASQ_MANAGER_GET_PRIVATE(manager); + guint err; + + if (WIFEXITED(status)) { + err = WEXITSTATUS(status); + if (err != 0) { + _LOGW("dnsmasq exited with error: %s", nm_utils_dnsmasq_status_to_string(err, NULL, 0)); + } + } else if (WIFSTOPPED(status)) { + _LOGW("dnsmasq stopped unexpectedly with signal %d", WSTOPSIG(status)); + } else if (WIFSIGNALED(status)) { + _LOGW("dnsmasq died with signal %d", WTERMSIG(status)); + } else { + _LOGW("dnsmasq died from an unknown cause"); + } + + priv->pid = 0; + priv->dm_watch_id = 0; + + g_signal_emit(manager, signals[STATE_CHANGED], 0, NM_DNSMASQ_STATUS_DEAD); +} + +static GPtrArray * +create_dm_cmd_line(const char * iface, + const NMIP4Config *ip4_config, + const char * pidfile, + gboolean announce_android_metered, + GError ** error) +{ + gs_unref_ptrarray GPtrArray *cmd = NULL; + nm_auto_free_gstring GString *s = NULL; + char first[INET_ADDRSTRLEN]; + char last[INET_ADDRSTRLEN]; + char listen_address_s[INET_ADDRSTRLEN]; + char tmpaddr[INET_ADDRSTRLEN]; + gs_free char * error_desc = NULL; + const char * dm_binary; + const NMPlatformIP4Address * listen_address; + guint i, n; + + listen_address = nm_ip4_config_get_first_address(ip4_config); + + g_return_val_if_fail(listen_address, NULL); + + dm_binary = nm_utils_find_helper("dnsmasq", DNSMASQ_PATH, error); + if (!dm_binary) + return NULL; + + cmd = g_ptr_array_new_with_free_func(g_free); + + nm_strv_ptrarray_add_string_dup(cmd, dm_binary); + + if (nm_logging_enabled(LOGL_TRACE, LOGD_SHARING) || getenv("NM_DNSMASQ_DEBUG")) { + nm_strv_ptrarray_add_string_dup(cmd, "--log-dhcp"); + nm_strv_ptrarray_add_string_dup(cmd, "--log-queries"); + } + + /* dnsmasq may read from its default config file location, which if that + * location is a valid config file, it will combine with the options here + * and cause undesirable side-effects. Like sending bogus IP addresses + * as the gateway or whatever. So tell dnsmasq not to use any config file + * at all. + */ + nm_strv_ptrarray_add_string_dup(cmd, "--conf-file=/dev/null"); + + nm_strv_ptrarray_add_string_dup(cmd, "--no-hosts"); + nm_strv_ptrarray_add_string_dup(cmd, "--keep-in-foreground"); + nm_strv_ptrarray_add_string_dup(cmd, "--bind-interfaces"); + nm_strv_ptrarray_add_string_dup(cmd, "--except-interface=lo"); + nm_strv_ptrarray_add_string_dup(cmd, "--clear-on-reload"); + + /* Use strict order since in the case of VPN connections, the VPN's + * nameservers will be first in resolv.conf, and those need to be tried + * first by dnsmasq to successfully resolve names from the VPN. + */ + nm_strv_ptrarray_add_string_dup(cmd, "--strict-order"); + + _nm_utils_inet4_ntop(listen_address->address, listen_address_s); + + nm_strv_ptrarray_add_string_concat(cmd, "--listen-address=", listen_address_s); + + if (!nm_dnsmasq_utils_get_range(listen_address, first, last, &error_desc)) { + g_set_error_literal(error, NM_MANAGER_ERROR, NM_MANAGER_ERROR_FAILED, error_desc); + _LOGW("failed to find DHCP address ranges: %s", error_desc); + return NULL; + } + + nm_strv_ptrarray_add_string_printf(cmd, "--dhcp-range=%s,%s,60m", first, last); + + if (nm_ip4_config_best_default_route_get(ip4_config)) { + nm_strv_ptrarray_add_string_concat(cmd, "--dhcp-option=option:router,", listen_address_s); + } + + if ((n = nm_ip4_config_get_num_nameservers(ip4_config))) { + nm_gstring_prepare(&s); + g_string_append(s, "--dhcp-option=option:dns-server"); + for (i = 0; i < n; i++) { + g_string_append_c(s, ','); + g_string_append( + s, + _nm_utils_inet4_ntop(nm_ip4_config_get_nameserver(ip4_config, i), tmpaddr)); + } + nm_strv_ptrarray_take_gstring(cmd, &s); + } + + if ((n = nm_ip4_config_get_num_searches(ip4_config))) { + nm_gstring_prepare(&s); + g_string_append(s, "--dhcp-option=option:domain-search"); + for (i = 0; i < n; i++) { + g_string_append_c(s, ','); + g_string_append(s, nm_ip4_config_get_search(ip4_config, i)); + } + nm_strv_ptrarray_take_gstring(cmd, &s); + } + + if (announce_android_metered) { + /* force option 43 to announce ANDROID_METERED. Do this, even if the client + * did not ask for this option. See https://www.lorier.net/docs/android-metered.html */ + nm_strv_ptrarray_add_string_dup(cmd, "--dhcp-option-force=43,ANDROID_METERED"); + } + + nm_strv_ptrarray_add_string_dup(cmd, "--dhcp-lease-max=50"); + + nm_strv_ptrarray_add_string_printf(cmd, + "--dhcp-leasefile=%s/dnsmasq-%s.leases", + NMSTATEDIR, + iface); + + nm_strv_ptrarray_add_string_concat(cmd, "--pid-file=", pidfile); + + /* dnsmasq exits if the conf dir is not present */ + if (g_file_test(CONFDIR, G_FILE_TEST_IS_DIR)) + nm_strv_ptrarray_add_string_dup(cmd, "--conf-dir=" CONFDIR); + + g_ptr_array_add(cmd, NULL); + return g_steal_pointer(&cmd); +} + +static void +kill_existing_by_pidfile(const char *pidfile) +{ + char * contents = NULL; + pid_t pid; + char proc_path[250]; + char * cmdline_contents = NULL; + guint64 start_time; + const char *exe; + + if (!pidfile || !g_file_get_contents(pidfile, &contents, NULL, NULL)) + return; + + pid = _nm_utils_ascii_str_to_int64(contents, 10, 1, G_MAXUINT64, 0); + if (pid == 0) + goto out; + + start_time = nm_utils_get_start_time_for_pid(pid, NULL, NULL); + if (start_time == 0) + goto out; + + nm_sprintf_buf(proc_path, "/proc/%lld/cmdline", (long long) pid); + if (!g_file_get_contents(proc_path, &cmdline_contents, NULL, NULL)) + goto out; + + exe = strrchr(cmdline_contents, '/'); + if ((exe && strcmp(&exe[1], "dnsmasq") == 0) || (strcmp(cmdline_contents, DNSMASQ_PATH) == 0)) { + nm_utils_kill_process_sync(pid, start_time, SIGKILL, LOGD_SHARING, "dnsmasq", 0, 0, 500); + } + +out: + unlink(pidfile); + g_free(cmdline_contents); + g_free(contents); +} + +gboolean +nm_dnsmasq_manager_start(NMDnsMasqManager *manager, + NMIP4Config * ip4_config, + gboolean announce_android_metered, + GError ** error) +{ + NMDnsMasqManagerPrivate *priv; + gs_unref_ptrarray GPtrArray *dm_cmd = NULL; + gs_free char * cmd_str = NULL; + + g_return_val_if_fail(NM_IS_DNSMASQ_MANAGER(manager), FALSE); + g_return_val_if_fail(!error || !*error, FALSE); + g_return_val_if_fail(nm_ip4_config_get_num_addresses(ip4_config) > 0, FALSE); + + priv = NM_DNSMASQ_MANAGER_GET_PRIVATE(manager); + + kill_existing_by_pidfile(priv->pidfile); + + dm_cmd = + create_dm_cmd_line(priv->iface, ip4_config, priv->pidfile, announce_android_metered, error); + if (!dm_cmd) + return FALSE; + + _LOGI("starting dnsmasq..."); + _LOGD("command line: %s", (cmd_str = g_strjoinv(" ", (char **) dm_cmd->pdata))); + + priv->pid = 0; + if (!g_spawn_async(NULL, + (char **) dm_cmd->pdata, + NULL, + G_SPAWN_DO_NOT_REAP_CHILD, + nm_utils_setpgid, + NULL, + &priv->pid, + error)) + return FALSE; + + nm_assert(priv->pid > 0); + + _LOGD("dnsmasq started with pid %d", priv->pid); + + priv->dm_watch_id = g_child_watch_add(priv->pid, (GChildWatchFunc) dm_watch_cb, manager); + + return TRUE; +} + +void +nm_dnsmasq_manager_stop(NMDnsMasqManager *manager) +{ + NMDnsMasqManagerPrivate *priv; + + g_return_if_fail(NM_IS_DNSMASQ_MANAGER(manager)); + + priv = NM_DNSMASQ_MANAGER_GET_PRIVATE(manager); + + nm_clear_g_source(&priv->dm_watch_id); + + if (priv->pid) { + nm_utils_kill_child_async(priv->pid, SIGTERM, LOGD_SHARING, "dnsmasq", 2000, NULL, NULL); + priv->pid = 0; + } + + unlink(priv->pidfile); +} + +/*****************************************************************************/ + +static void +nm_dnsmasq_manager_init(NMDnsMasqManager *manager) +{} + +NMDnsMasqManager * +nm_dnsmasq_manager_new(const char *iface) +{ + NMDnsMasqManager * manager; + NMDnsMasqManagerPrivate *priv; + + manager = g_object_new(NM_TYPE_DNSMASQ_MANAGER, NULL); + + priv = NM_DNSMASQ_MANAGER_GET_PRIVATE(manager); + priv->iface = g_strdup(iface); + priv->pidfile = g_strdup_printf(RUNSTATEDIR "/nm-dnsmasq-%s.pid", iface); + + return manager; +} + +static void +finalize(GObject *object) +{ + NMDnsMasqManagerPrivate *priv = NM_DNSMASQ_MANAGER_GET_PRIVATE(object); + + nm_dnsmasq_manager_stop(NM_DNSMASQ_MANAGER(object)); + + g_free(priv->iface); + g_free(priv->pidfile); + + G_OBJECT_CLASS(nm_dnsmasq_manager_parent_class)->finalize(object); +} + +static void +nm_dnsmasq_manager_class_init(NMDnsMasqManagerClass *manager_class) +{ + GObjectClass *object_class = G_OBJECT_CLASS(manager_class); + + object_class->finalize = finalize; + + signals[STATE_CHANGED] = g_signal_new(NM_DNS_MASQ_MANAGER_STATE_CHANGED, + G_OBJECT_CLASS_TYPE(object_class), + G_SIGNAL_RUN_FIRST, + 0, + NULL, + NULL, + g_cclosure_marshal_VOID__UINT, + G_TYPE_NONE, + 1, + G_TYPE_UINT); +} |