diff options
Diffstat (limited to 'src/dns-manager/nm-dns-plugin.c')
| -rw-r--r-- | src/dns-manager/nm-dns-plugin.c | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/src/dns-manager/nm-dns-plugin.c b/src/dns-manager/nm-dns-plugin.c new file mode 100644 index 00000000..f7d65a52 --- /dev/null +++ b/src/dns-manager/nm-dns-plugin.c @@ -0,0 +1,319 @@ +/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */ +/* 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, 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) 2010 Red Hat, Inc. + * + */ + +#include <config.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <glib.h> + +#include "nm-dns-plugin.h" +#include "nm-logging.h" + +typedef struct { + gboolean disposed; + + GPid pid; + guint32 watch_id; + char *progname; + char *pidfile; +} NMDnsPluginPrivate; + +#define NM_DNS_PLUGIN_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), NM_TYPE_DNS_PLUGIN, NMDnsPluginPrivate)) + +G_DEFINE_TYPE_EXTENDED (NMDnsPlugin, nm_dns_plugin, G_TYPE_OBJECT, G_TYPE_FLAG_ABSTRACT, {}) + +enum { + FAILED, + CHILD_QUIT, + LAST_SIGNAL +}; +static guint signals[LAST_SIGNAL] = { 0 }; + +/********************************************/ + +gboolean +nm_dns_plugin_update (NMDnsPlugin *self, + const GSList *vpn_configs, + const GSList *dev_configs, + const GSList *other_configs, + const char *hostname) +{ + g_return_val_if_fail (NM_DNS_PLUGIN_GET_CLASS (self)->update != NULL, FALSE); + + return NM_DNS_PLUGIN_GET_CLASS (self)->update (self, + vpn_configs, + dev_configs, + other_configs, + hostname); +} + +static gboolean +is_caching (NMDnsPlugin *self) +{ + return FALSE; +} + +gboolean +nm_dns_plugin_is_caching (NMDnsPlugin *self) +{ + return NM_DNS_PLUGIN_GET_CLASS (self)->is_caching (self); +} + +const char * +nm_dns_plugin_get_name (NMDnsPlugin *self) +{ + g_assert (NM_DNS_PLUGIN_GET_CLASS (self)->get_name); + return NM_DNS_PLUGIN_GET_CLASS (self)->get_name (self); +} + +/********************************************/ + +static void +kill_existing (const char *progname, const char *pidfile, const char *kill_match) +{ + char *contents = NULL; + glong pid; + char *proc_path = NULL; + char *cmdline_contents = NULL; + + if (!g_file_get_contents (pidfile, &contents, NULL, NULL)) + return; + + 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, kill_match)) { + if (kill (pid, 0) == 0) { + nm_log_dbg (LOGD_DNS, "Killing stale %s child process %ld", progname, pid); + kill (pid, SIGKILL); + } + unlink (pidfile); + } + +out: + g_free (cmdline_contents); + g_free (proc_path); + g_free (contents); +} + +static void +watch_cb (GPid pid, gint status, gpointer user_data) +{ + NMDnsPlugin *self = NM_DNS_PLUGIN (user_data); + NMDnsPluginPrivate *priv = NM_DNS_PLUGIN_GET_PRIVATE (self); + + priv->pid = 0; + g_free (priv->progname); + priv->progname = NULL; + + g_signal_emit (self, signals[CHILD_QUIT], 0, status); +} + +static void +child_setup (gpointer user_data G_GNUC_UNUSED) +{ + /* We are in the child process at this point */ + pid_t pid = getpid (); + setpgid (pid, pid); +} + +GPid +nm_dns_plugin_child_spawn (NMDnsPlugin *self, + const char **argv, + const char *pidfile, + const char *kill_match) +{ + NMDnsPluginPrivate *priv = NM_DNS_PLUGIN_GET_PRIVATE (self); + GError *error = NULL; + char *cmdline; + + g_return_val_if_fail (argv != NULL, 0); + g_return_val_if_fail (argv[0] != NULL, 0); + + g_warn_if_fail (priv->progname == NULL); + g_free (priv->progname); + priv->progname = g_path_get_basename (argv[0]); + + if (pidfile) { + g_return_val_if_fail (kill_match != NULL, 0); + kill_existing (priv->progname, pidfile, kill_match); + + g_free (priv->pidfile); + priv->pidfile = g_strdup (pidfile); + } + + nm_log_info (LOGD_DNS, "DNS: starting %s...", priv->progname); + cmdline = g_strjoinv (" ", (char **) argv); + nm_log_dbg (LOGD_DNS, "DNS: command line: %s", cmdline); + g_free (cmdline); + + priv->pid = 0; + if (g_spawn_async (NULL, (char **) argv, NULL, + G_SPAWN_DO_NOT_REAP_CHILD, + child_setup, + NULL, &priv->pid, + &error)) { + nm_log_dbg (LOGD_DNS, "%s started with pid %d", priv->progname, priv->pid); + priv->watch_id = g_child_watch_add (priv->pid, (GChildWatchFunc) watch_cb, self); + } else { + nm_log_warn (LOGD_DNS, "Failed to spawn %s: (%d) %s", + priv->progname, error ? error->code : -1, + error && error->message ? error->message : "(unknown)"); + g_clear_error (&error); + } + + return priv->pid; +} + +typedef struct { + int pid; + char *progname; +} KillInfo; + +static gboolean +ensure_killed (gpointer data) +{ + KillInfo *info = data; + + if (kill (info->pid, 0) == 0) + kill (info->pid, SIGKILL); + + /* ensure the child is reaped */ + nm_log_dbg (LOGD_DNS, "waiting for %s pid %d to exit", info->progname, info->pid); + waitpid (info->pid, NULL, 0); + nm_log_dbg (LOGD_DNS, "dnsmasq pid %d cleaned up", info->progname, info->pid); + + g_free (info->progname); + g_free (info); + return FALSE; +} + +gboolean nm_dns_plugin_child_kill (NMDnsPlugin *self) +{ + NMDnsPluginPrivate *priv = NM_DNS_PLUGIN_GET_PRIVATE (self); + + if (priv->watch_id) { + g_source_remove (priv->watch_id); + priv->watch_id = 0; + } + + if (priv->pid) { + KillInfo *info; + + if (kill (priv->pid, SIGTERM) == 0) { + info = g_malloc0 (sizeof (KillInfo)); + info->pid = priv->pid; + info->progname = g_strdup (priv->progname); + g_timeout_add_seconds (2, ensure_killed, info); + } else { + kill (priv->pid, SIGKILL); + + /* ensure the child is reaped */ + nm_log_dbg (LOGD_DNS, "waiting for %s pid %d to exit", priv->progname, priv->pid); + waitpid (priv->pid, NULL, 0); + nm_log_dbg (LOGD_DNS, "%s pid %d cleaned up", priv->progname, priv->pid); + } + priv->pid = 0; + g_free (priv->progname); + priv->progname = NULL; + } + + if (priv->pidfile) { + unlink (priv->pidfile); + g_free (priv->pidfile); + priv->pidfile = NULL; + } + + return TRUE; +} + +/********************************************/ + +static void +nm_dns_plugin_init (NMDnsPlugin *self) +{ +} + +static void +dispose (GObject *object) +{ + NMDnsPlugin *self = NM_DNS_PLUGIN (object); + NMDnsPluginPrivate *priv = NM_DNS_PLUGIN_GET_PRIVATE (self); + + if (!priv->disposed) { + priv->disposed = TRUE; + + nm_dns_plugin_child_kill (self); + } + + G_OBJECT_CLASS (nm_dns_plugin_parent_class)->dispose (object); +} + +static void +finalize (GObject *object) +{ + NMDnsPlugin *self = NM_DNS_PLUGIN (object); + NMDnsPluginPrivate *priv = NM_DNS_PLUGIN_GET_PRIVATE (self); + + g_free (priv->progname); + g_free (priv->pidfile); + + G_OBJECT_CLASS (nm_dns_plugin_parent_class)->finalize (object); +} + +static void +nm_dns_plugin_class_init (NMDnsPluginClass *plugin_class) +{ + GObjectClass *object_class = G_OBJECT_CLASS (plugin_class); + + g_type_class_add_private (plugin_class, sizeof (NMDnsPluginPrivate)); + + /* virtual methods */ + object_class->dispose = dispose; + object_class->finalize = finalize; + plugin_class->is_caching = is_caching; + + /* signals */ + signals[FAILED] = + g_signal_new (NM_DNS_PLUGIN_FAILED, + G_OBJECT_CLASS_TYPE (object_class), + G_SIGNAL_RUN_FIRST, + G_STRUCT_OFFSET (NMDnsPluginClass, failed), + NULL, NULL, + g_cclosure_marshal_VOID__VOID, + G_TYPE_NONE, 0); + + signals[CHILD_QUIT] = + g_signal_new (NM_DNS_PLUGIN_CHILD_QUIT, + G_OBJECT_CLASS_TYPE (object_class), + G_SIGNAL_RUN_FIRST, + G_STRUCT_OFFSET (NMDnsPluginClass, child_quit), + NULL, NULL, + g_cclosure_marshal_VOID__INT, + G_TYPE_NONE, 1, G_TYPE_INT); +} + |