diff options
Diffstat (limited to 'src/dnsmasq-manager/nm-dnsmasq-manager.c')
| -rw-r--r-- | src/dnsmasq-manager/nm-dnsmasq-manager.c | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/src/dnsmasq-manager/nm-dnsmasq-manager.c b/src/dnsmasq-manager/nm-dnsmasq-manager.c new file mode 100644 index 00000000..e6c67a1e --- /dev/null +++ b/src/dnsmasq-manager/nm-dnsmasq-manager.c @@ -0,0 +1,495 @@ +/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */ +/* NetworkManager -- Network link manager + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Copyright (C) 2008 - 2010 Red Hat, Inc. + */ + +#include <sys/types.h> +#include <sys/wait.h> +#include <signal.h> +#include <string.h> +#include <unistd.h> +#include <arpa/inet.h> +#include <stdlib.h> + +#include "nm-dnsmasq-manager.h" +#include "nm-logging.h" +#include "nm-glib-compat.h" + +typedef struct { + char *iface; + char *pidfile; + GPid pid; + guint32 dm_watch_id; +} NMDnsMasqManagerPrivate; + +#define NM_DNSMASQ_MANAGER_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), NM_TYPE_DNSMASQ_MANAGER, NMDnsMasqManagerPrivate)) + +G_DEFINE_TYPE (NMDnsMasqManager, nm_dnsmasq_manager, G_TYPE_OBJECT) + +enum { + STATE_CHANGED, + + LAST_SIGNAL +}; + +static guint signals[LAST_SIGNAL] = { 0 }; + +typedef enum { + NM_DNSMASQ_MANAGER_ERROR_NOT_FOUND, +} NMDnsMasqManagerError; + +GQuark +nm_dnsmasq_manager_error_quark (void) +{ + static GQuark quark; + + if (!quark) + quark = g_quark_from_static_string ("nm_dnsmasq_manager_error"); + + return quark; +} + +static void +nm_dnsmasq_manager_init (NMDnsMasqManager *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); + + g_type_class_add_private (manager_class, sizeof (NMDnsMasqManagerPrivate)); + + object_class->finalize = finalize; + + /* signals */ + signals[STATE_CHANGED] = + g_signal_new ("state-changed", + G_OBJECT_CLASS_TYPE (object_class), + G_SIGNAL_RUN_FIRST, + G_STRUCT_OFFSET (NMDnsMasqManagerClass, state_changed), + NULL, NULL, + g_cclosure_marshal_VOID__UINT, + G_TYPE_NONE, 1, + G_TYPE_UINT); +} + +NMDnsMasqManager * +nm_dnsmasq_manager_new (const char *iface) +{ + NMDnsMasqManager *manager; + NMDnsMasqManagerPrivate *priv; + + manager = (NMDnsMasqManager *) g_object_new (NM_TYPE_DNSMASQ_MANAGER, NULL); + if (!manager) + return NULL; + + priv = NM_DNSMASQ_MANAGER_GET_PRIVATE (manager); + priv->iface = g_strdup (iface); + priv->pidfile = g_strdup_printf (LOCALSTATEDIR "/run/nm-dnsmasq-%s.pid", iface); + + return manager; +} + +typedef struct { + GPtrArray *array; + GStringChunk *chunk; +} NMCmdLine; + +static NMCmdLine * +nm_cmd_line_new (void) +{ + NMCmdLine *cmd; + + cmd = g_slice_new (NMCmdLine); + cmd->array = g_ptr_array_new (); + cmd->chunk = g_string_chunk_new (1024); + + return cmd; +} + +static void +nm_cmd_line_destroy (NMCmdLine *cmd) +{ + g_ptr_array_free (cmd->array, TRUE); + g_string_chunk_free (cmd->chunk); + g_slice_free (NMCmdLine, cmd); +} + +static char * +nm_cmd_line_to_str (NMCmdLine *cmd) +{ + char *str; + + g_ptr_array_add (cmd->array, NULL); + str = g_strjoinv (" ", (gchar **) cmd->array->pdata); + g_ptr_array_remove_index (cmd->array, cmd->array->len - 1); + + return str; +} + +static void +nm_cmd_line_add_string (NMCmdLine *cmd, const char *str) +{ + g_ptr_array_add (cmd->array, g_string_chunk_insert (cmd->chunk, str)); +} + +/*******************************************/ + +static inline const char * +nm_find_dnsmasq (void) +{ + static const char *dnsmasq_binary_paths[] = { + "/usr/local/sbin/dnsmasq", + "/usr/sbin/dnsmasq", + "/sbin/dnsmasq", + NULL + }; + + const char **dnsmasq_binary = dnsmasq_binary_paths; + + while (*dnsmasq_binary != NULL) { + if (g_file_test (*dnsmasq_binary, G_FILE_TEST_EXISTS)) + break; + dnsmasq_binary++; + } + + return *dnsmasq_binary; +} + +static void +dm_exit_code (guint dm_exit_status) +{ + char *msg = "Unknown error"; + + switch (dm_exit_status) { + case 1: + msg = "Configuration problem"; + break; + case 2: + msg = "Network access problem (address in use; permissions; etc)"; + break; + case 3: + msg = "Filesystem problem (missing file/directory; permissions; etc)"; + break; + case 4: + msg = "Memory allocation failure"; + break; + case 5: + msg = "Other problem"; + break; + default: + if (dm_exit_status >= 11) + msg = "Lease-script 'init' process failure"; + break; + } + + nm_log_warn (LOGD_SHARING, "dnsmasq exited with error: %s (%d)", msg, dm_exit_status); +} + +static void +dm_watch_cb (GPid pid, gint 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) + dm_exit_code (err); + } else if (WIFSTOPPED (status)) { + nm_log_warn (LOGD_SHARING, "dnsmasq stopped unexpectedly with signal %d", WSTOPSIG (status)); + } else if (WIFSIGNALED (status)) { + nm_log_warn (LOGD_SHARING, "dnsmasq died with signal %d", WTERMSIG (status)); + } else { + nm_log_warn (LOGD_SHARING, "dnsmasq died from an unknown cause"); + } + + priv->pid = 0; + + g_signal_emit (manager, signals[STATE_CHANGED], 0, NM_DNSMASQ_STATUS_DEAD); +} + +static NMCmdLine * +create_dm_cmd_line (const char *iface, + NMIP4Config *ip4_config, + const char *pidfile, + GError **error) +{ + const char *dm_binary; + NMCmdLine *cmd; + GString *s; + NMIP4Address *tmp; + struct in_addr addr; + char buf[INET_ADDRSTRLEN + 15]; + char localaddr[INET_ADDRSTRLEN + 1]; + int i; + + dm_binary = nm_find_dnsmasq (); + if (!dm_binary) { + g_set_error (error, NM_DNSMASQ_MANAGER_ERROR, NM_DNSMASQ_MANAGER_ERROR_NOT_FOUND, + "Could not find dnsmasq binary."); + return NULL; + } + + /* Find the IP4 address to use */ + tmp = nm_ip4_config_get_address (ip4_config, 0); + + /* Create dnsmasq command line */ + cmd = nm_cmd_line_new (); + nm_cmd_line_add_string (cmd, dm_binary); + + if (getenv ("NM_DNSMASQ_DEBUG")) { + nm_cmd_line_add_string (cmd, "--log-dhcp"); + nm_cmd_line_add_string (cmd, "--log-queries"); + } + + /* dnsmasq may read from it's 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 give dnsmasq a bogus config file + * location to avoid screwing up the configuration we're passing to it. + */ + memset (buf, 0, sizeof (buf)); + strcpy (buf, "/tmp/"); + for (i = 5; i < 15; i++) + buf[i] = (char) (g_random_int_range ((guint32) 'a', (guint32) 'z') & 0xFF); + strcat (buf, ".conf"); + + nm_cmd_line_add_string (cmd, "--conf-file"); + nm_cmd_line_add_string (cmd, buf); + + nm_cmd_line_add_string (cmd, "--no-hosts"); + nm_cmd_line_add_string (cmd, "--keep-in-foreground"); + nm_cmd_line_add_string (cmd, "--bind-interfaces"); + nm_cmd_line_add_string (cmd, "--except-interface=lo"); + nm_cmd_line_add_string (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_cmd_line_add_string (cmd, "--strict-order"); + + s = g_string_new ("--listen-address="); + addr.s_addr = nm_ip4_address_get_address (tmp); + if (!inet_ntop (AF_INET, &addr, &localaddr[0], INET_ADDRSTRLEN)) { + nm_log_warn (LOGD_SHARING, "error converting IP4 address 0x%X", + ntohl (addr.s_addr)); + goto error; + } + g_string_append (s, localaddr); + nm_cmd_line_add_string (cmd, s->str); + g_string_free (s, TRUE); + + s = g_string_new ("--dhcp-range="); + + /* Add start of address range */ + addr.s_addr = nm_ip4_address_get_address (tmp) + htonl (9); + if (!inet_ntop (AF_INET, &addr, &buf[0], INET_ADDRSTRLEN)) { + nm_log_warn (LOGD_SHARING, "error converting IP4 address 0x%X", + ntohl (addr.s_addr)); + goto error; + } + g_string_append (s, buf); + + g_string_append_c (s, ','); + + /* Add end of address range */ + addr.s_addr = nm_ip4_address_get_address (tmp) + htonl (99); + if (!inet_ntop (AF_INET, &addr, &buf[0], INET_ADDRSTRLEN)) { + nm_log_warn (LOGD_SHARING, "error converting IP4 address 0x%X", + ntohl (addr.s_addr)); + goto error; + } + g_string_append (s, buf); + + g_string_append (s, ",60m"); + nm_cmd_line_add_string (cmd, s->str); + g_string_free (s, TRUE); + + s = g_string_new ("--dhcp-option=option:router,"); + g_string_append (s, localaddr); + nm_cmd_line_add_string (cmd, s->str); + g_string_free (s, TRUE); + + nm_cmd_line_add_string (cmd, "--dhcp-lease-max=50"); + + s = g_string_new ("--pid-file="); + g_string_append (s, pidfile); + nm_cmd_line_add_string (cmd, s->str); + g_string_free (s, TRUE); + + return cmd; + +error: + nm_cmd_line_destroy (cmd); + return NULL; +} + +static void +dm_child_setup (gpointer user_data G_GNUC_UNUSED) +{ + /* We are in the child process at this point */ + pid_t pid = getpid (); + setpgid (pid, pid); +} + +static void +kill_existing_for_iface (const char *iface, const char *pidfile) +{ + char *contents = NULL; + glong pid; + char *proc_path = NULL; + char *cmdline_contents = NULL; + + if (!g_file_get_contents (pidfile, &contents, NULL, NULL)) + goto out; + + pid = strtol (contents, NULL, 10); + if (pid < 1 || pid > INT_MAX) + goto out; + + proc_path = g_strdup_printf ("/proc/%ld/cmdline", pid); + if (!g_file_get_contents (proc_path, &cmdline_contents, NULL, NULL)) + goto out; + + if (strstr (cmdline_contents, "bin/dnsmasq")) { + if (kill (pid, 0)) { + nm_log_dbg (LOGD_SHARING, "Killing stale dnsmasq process %ld", pid); + kill (pid, SIGKILL); + } + unlink (pidfile); + } + +out: + g_free (cmdline_contents); + g_free (proc_path); + g_free (contents); +} + +gboolean +nm_dnsmasq_manager_start (NMDnsMasqManager *manager, + NMIP4Config *ip4_config, + GError **error) +{ + NMDnsMasqManagerPrivate *priv; + NMCmdLine *dm_cmd; + char *cmd_str; + + g_return_val_if_fail (NM_IS_DNSMASQ_MANAGER (manager), FALSE); + if (error) + g_return_val_if_fail (*error == NULL, FALSE); + + priv = NM_DNSMASQ_MANAGER_GET_PRIVATE (manager); + + kill_existing_for_iface (priv->iface, priv->pidfile); + + dm_cmd = create_dm_cmd_line (priv->iface, ip4_config, priv->pidfile, error); + if (!dm_cmd) + return FALSE; + + g_ptr_array_add (dm_cmd->array, NULL); + + nm_log_info (LOGD_SHARING, "Starting dnsmasq..."); + + cmd_str = nm_cmd_line_to_str (dm_cmd); + nm_log_dbg (LOGD_SHARING, "Command line: %s", cmd_str); + g_free (cmd_str); + + priv->pid = 0; + if (!g_spawn_async (NULL, (char **) dm_cmd->array->pdata, NULL, + G_SPAWN_DO_NOT_REAP_CHILD, + dm_child_setup, + NULL, &priv->pid, error)) { + goto out; + } + + nm_log_dbg (LOGD_SHARING, "dnsmasq started with pid %d", priv->pid); + + priv->dm_watch_id = g_child_watch_add (priv->pid, (GChildWatchFunc) dm_watch_cb, manager); + + out: + if (dm_cmd) + nm_cmd_line_destroy (dm_cmd); + + return priv->pid > 0; +} + +static gboolean +ensure_killed (gpointer data) +{ + int pid = GPOINTER_TO_INT (data); + + if (kill (pid, 0) == 0) + kill (pid, SIGKILL); + + /* ensure the child is reaped */ + nm_log_dbg (LOGD_SHARING, "waiting for dnsmasq pid %d to exit", pid); + waitpid (pid, NULL, 0); + nm_log_dbg (LOGD_SHARING, "dnsmasq pid %d cleaned up", pid); + + return FALSE; +} + +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); + + if (priv->dm_watch_id) { + g_source_remove (priv->dm_watch_id); + priv->dm_watch_id = 0; + } + + if (priv->pid) { + if (kill (priv->pid, SIGTERM) == 0) + g_timeout_add_seconds (2, ensure_killed, GINT_TO_POINTER (priv->pid)); + else { + kill (priv->pid, SIGKILL); + + /* ensure the child is reaped */ + nm_log_dbg (LOGD_SHARING, "waiting for dnsmasq pid %d to exit", priv->pid); + waitpid (priv->pid, NULL, 0); + nm_log_dbg (LOGD_SHARING, "dnsmasq pid %d cleaned up", priv->pid); + } + + priv->pid = 0; + } + + unlink (priv->pidfile); +} |