/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2005 - 2012 Red Hat, Inc.
*/
#include <config.h>
#define __CONFIG_H__
#define _XOPEN_SOURCE
#include <time.h>
#undef _XOPEN_SOURCE
#include "src/core/nm-default-daemon.h"
#if WITH_DHCLIENT
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <ctype.h>
#include "libnm-glib-aux/nm-dedup-multi.h"
#include "nm-utils.h"
#include "nm-dhcp-dhclient-utils.h"
#include "nm-dhcp-manager.h"
#include "NetworkManagerUtils.h"
#include "nm-dhcp-listener.h"
#include "nm-dhcp-client-logging.h"
/*****************************************************************************/
static const char *
_addr_family_to_path_part(int addr_family)
{
nm_assert(NM_IN_SET(addr_family, AF_INET, AF_INET6));
return (addr_family == AF_INET6) ? "6" : "";
}
/*****************************************************************************/
#define NM_TYPE_DHCP_DHCLIENT (nm_dhcp_dhclient_get_type())
#define NM_DHCP_DHCLIENT(obj) \
(G_TYPE_CHECK_INSTANCE_CAST((obj), NM_TYPE_DHCP_DHCLIENT, NMDhcpDhclient))
#define NM_DHCP_DHCLIENT_CLASS(klass) \
(G_TYPE_CHECK_CLASS_CAST((klass), NM_TYPE_DHCP_DHCLIENT, NMDhcpDhclientClass))
#define NM_IS_DHCP_DHCLIENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj), NM_TYPE_DHCP_DHCLIENT))
#define NM_IS_DHCP_DHCLIENT_CLASS(klass) \
(G_TYPE_CHECK_CLASS_TYPE((klass), NM_TYPE_DHCP_DHCLIENT))
#define NM_DHCP_DHCLIENT_GET_CLASS(obj) \
(G_TYPE_INSTANCE_GET_CLASS((obj), NM_TYPE_DHCP_DHCLIENT, NMDhcpDhclientClass))
typedef struct _NMDhcpDhclient NMDhcpDhclient;
typedef struct _NMDhcpDhclientClass NMDhcpDhclientClass;
static GType nm_dhcp_dhclient_get_type(void);
/*****************************************************************************/
typedef struct {
char * conf_file;
const char * def_leasefile;
char * lease_file;
char * pid_file;
NMDhcpListener *dhcp_listener;
} NMDhcpDhclientPrivate;
struct _NMDhcpDhclient {
NMDhcpClient parent;
NMDhcpDhclientPrivate _priv;
};
struct _NMDhcpDhclientClass {
NMDhcpClientClass parent;
};
G_DEFINE_TYPE(NMDhcpDhclient, nm_dhcp_dhclient, NM_TYPE_DHCP_CLIENT)
#define NM_DHCP_DHCLIENT_GET_PRIVATE(self) \
_NM_GET_PRIVATE(self, NMDhcpDhclient, NM_IS_DHCP_DHCLIENT)
/*****************************************************************************/
static const char *
nm_dhcp_dhclient_get_path(void)
{
return nm_utils_find_helper("dhclient", DHCLIENT_PATH, NULL);
}
/**
* get_dhclient_leasefile():
* @addr_family: AF_INET or AF_INET6
* @iface: the interface name of the device on which DHCP will be done
* @uuid: the connection UUID to which the returned lease should belong
* @out_preferred_path: on return, the "most preferred" leasefile path
*
* Returns the path of an existing leasefile (if any) for this interface and
* connection UUID. Also returns the "most preferred" leasefile path, which
* may be different than any found leasefile.
*
* Returns: an existing leasefile, or %NULL if no matching leasefile could be found
*/
static char *
get_dhclient_leasefile(int addr_family,
const char *iface,
const char *uuid,
char ** out_preferred_path)
{
gs_free char *path = NULL;
if (nm_dhcp_utils_get_leasefile_path(addr_family, "dhclient", iface, uuid, &path)) {
NM_SET_OUT(out_preferred_path, g_strdup(path));
return g_steal_pointer(&path);
}
NM_SET_OUT(out_preferred_path, g_steal_pointer(&path));
/* If the leasefile we're looking for doesn't exist yet in the new location
* (eg, /var/lib/NetworkManager) then look in old locations to maintain
* backwards compatibility with external tools (like dracut) that put
* leasefiles there.
*/
/* Old Debian, SUSE, and Mandriva location */
g_free(path);
path = g_strdup_printf(LOCALSTATEDIR "/lib/dhcp/dhclient%s-%s-%s.lease",
_addr_family_to_path_part(addr_family),
uuid,
iface);
if (g_file_test(path, G_FILE_TEST_EXISTS))
return g_steal_pointer(&path);
/* Old Red Hat and Fedora location */
g_free(path);
path = g_strdup_printf(LOCALSTATEDIR "/lib/dhclient/dhclient%s-%s-%s.lease",
_addr_family_to_path_part(addr_family),
uuid,
iface);
if (g_file_test(path, G_FILE_TEST_EXISTS))
return g_steal_pointer(&path);
/* Fail */
return NULL;
}
static gboolean
merge_dhclient_config(NMDhcpDhclient * self,
int addr_family,
const char * iface,
const char * conf_file,
GBytes * client_id,
const char * anycast_addr,
const char * hostname,
guint32 timeout,
gboolean use_fqdn,
NMDhcpHostnameFlags hostname_flags,
const char * mud_url,
const char *const * reject_servers,
const char * orig_path,
GBytes ** out_new_client_id,
GError ** error)
{
gs_free char *orig = NULL;
gs_free char *new = NULL;
g_return_val_if_fail(iface, FALSE);
g_return_val_if_fail(conf_file, FALSE);
if (orig_path && g_file_test(orig_path, G_FILE_TEST_EXISTS)) {
GError *read_error = NULL;
if (!g_file_get_contents(orig_path, &orig, NULL, &read_error)) {
_LOGW("error reading dhclient configuration %s: %s", orig_path, read_error->message);
g_error_free(read_error);
}
}
new = nm_dhcp_dhclient_create_config(iface,
addr_family,
client_id,
anycast_addr,
hostname,
timeout,
use_fqdn,
hostname_flags,
mud_url,
reject_servers,
orig_path,
orig,
out_new_client_id);
nm_assert(new);
return g_file_set_contents(conf_file, new, -1, error);
}
static char *
find_existing_config(NMDhcpDhclient *self, int addr_family, const char *iface, const char *uuid)
{
char *path;
/* NetworkManager-overridden configuration can be used to ship DHCP config
* with NetworkManager itself. It can be uuid-specific, device-specific
* or generic.
*/
if (uuid) {
path = g_strdup_printf(NMCONFDIR "/dhclient%s-%s.conf",
_addr_family_to_path_part(addr_family),
uuid);
_LOGD("looking for existing config %s", path);
if (g_file_test(path, G_FILE_TEST_EXISTS))
return path;
g_free(path);
}
path = g_strdup_printf(NMCONFDIR "/dhclient%s-%s.conf",
_addr_family_to_path_part(addr_family),
iface);
_LOGD("looking for existing config %s", path);
if (g_file_test(path, G_FILE_TEST_EXISTS))
return path;
g_free(path);
path = g_strdup_printf(NMCONFDIR "/dhclient%s.conf", _addr_family_to_path_part(addr_family));
_LOGD("looking for existing config %s", path);
if (g_file_test(path, G_FILE_TEST_EXISTS))
return path;
g_free(path);
/* Distribution's dhclient configuration is used so that we can use
* configuration shipped with dhclient (if any).
*
* This replaces conditional compilation based on distribution name. Fedora
* and Debian store the configs in /etc/dhcp while upstream defaults to /etc
* which is then used by many other distributions. Some distributions
* (including Fedora) don't even provide a default configuration file.
*/
path = g_strdup_printf(SYSCONFDIR "/dhcp/dhclient%s-%s.conf",
_addr_family_to_path_part(addr_family),
iface);
_LOGD("looking for existing config %s", path);
if (g_file_test(path, G_FILE_TEST_EXISTS))
return path;
g_free(path);
path = g_strdup_printf(SYSCONFDIR "/dhclient%s-%s.conf",
_addr_family_to_path_part(addr_family),
iface);
_LOGD("looking for existing config %s", path);
if (g_file_test(path, G_FILE_TEST_EXISTS))
return path;
g_free(path);
path =
g_strdup_printf(SYSCONFDIR "/dhcp/dhclient%s.conf", _addr_family_to_path_part(addr_family));
_LOGD("looking for existing config %s", path);
if (g_file_test(path, G_FILE_TEST_EXISTS))
return path;
g_free(path);
path = g_strdup_printf(SYSCONFDIR "/dhclient%s.conf", _addr_family_to_path_part(addr_family));
_LOGD("looking for existing config %s", path);
if (g_file_test(path, G_FILE_TEST_EXISTS))
return path;
g_free(path);
return NULL;
}
/* NM provides interface-specific options; thus the same dhclient config
* file cannot be used since DHCP transactions can happen in parallel.
* Since some distros don't have default per-interface dhclient config files,
* read their single config file and merge that into a custom per-interface
* config file along with the NM options.
*/
static char *
create_dhclient_config(NMDhcpDhclient * self,
int addr_family,
const char * iface,
const char * uuid,
GBytes * client_id,
const char * dhcp_anycast_addr,
const char * hostname,
guint32 timeout,
gboolean use_fqdn,
NMDhcpHostnameFlags hostname_flags,
const char * mud_url,
const char *const * reject_servers,
GBytes ** out_new_client_id)
{
gs_free char *orig = NULL;
char *new = NULL;
GError *error = NULL;
g_return_val_if_fail(iface != NULL, NULL);
new = g_strdup_printf(NMSTATEDIR "/dhclient%s-%s.conf",
_addr_family_to_path_part(addr_family),
iface);
_LOGD("creating composite dhclient config %s", new);
orig = find_existing_config(self, addr_family, iface, uuid);
if (orig)
_LOGD("merging existing dhclient config %s", orig);
else
_LOGD("no existing dhclient configuration to merge");
if (!merge_dhclient_config(self,
addr_family,
iface,
new,
client_id,
dhcp_anycast_addr,
hostname,
timeout,
use_fqdn,
hostname_flags,
mud_url,
reject_servers,
orig,
out_new_client_id,
&error)) {
_LOGW("error creating dhclient configuration: %s", error->message);
g_clear_error(&error);
}
return new;
}
static gboolean
dhclient_start(NMDhcpClient *client,
const char * mode_opt,
gboolean release,
pid_t * out_pid,
int prefixes,
GError ** error)
{
NMDhcpDhclient * self = NM_DHCP_DHCLIENT(client);
NMDhcpDhclientPrivate *priv = NM_DHCP_DHCLIENT_GET_PRIVATE(self);
gs_unref_ptrarray GPtrArray *argv = NULL;
pid_t pid;
gs_free_error GError *local = NULL;
const char * iface;
const char * uuid;
const char * system_bus_address;
const char * dhclient_path;
char * binary_name;
gs_free char * cmd_str = NULL;
gs_free char * pid_file = NULL;
gs_free char * system_bus_address_env = NULL;
gs_free char * preferred_leasefile_path = NULL;
const int addr_family = nm_dhcp_client_get_addr_family(client);
g_return_val_if_fail(!priv->pid_file, FALSE);
NM_SET_OUT(out_pid, 0);
dhclient_path = nm_dhcp_dhclient_get_path();
if (!dhclient_path) {
nm_utils_error_set_literal(error, NM_UTILS_ERROR_UNKNOWN, "dhclient binary not found");
return FALSE;
}
iface = nm_dhcp_client_get_iface(client);
uuid = nm_dhcp_client_get_uuid(client);
pid_file = g_strdup_printf(NMRUNDIR "/dhclient%s-%s.pid",
_addr_family_to_path_part(addr_family),
iface);
/* Kill any existing dhclient from the pidfile */
binary_name = g_path_get_basename(dhclient_path);
nm_dhcp_client_stop_existing(pid_file, binary_name);
g_free(binary_name);
if (release) {
/* release doesn't use the pidfile after killing an old client */
nm_clear_g_free(&pid_file);
}
g_free(priv->lease_file);
priv->lease_file = get_dhclient_leasefile(addr_family, iface, uuid, &preferred_leasefile_path);
nm_assert(preferred_leasefile_path);
if (!priv->lease_file) {
/* No existing leasefile, dhclient will create one at the preferred path */
priv->lease_file = g_steal_pointer(&preferred_leasefile_path);
} else if (!nm_streq0(priv->lease_file, preferred_leasefile_path)) {
gs_unref_object GFile *src = g_file_new_for_path(priv->lease_file);
gs_unref_object GFile *dst = g_file_new_for_path(preferred_leasefile_path);
/* Try to copy the existing leasefile to the preferred location */
if (!g_file_copy(src, dst, G_FILE_COPY_OVERWRITE, NULL, NULL, NULL, &local)) {
gs_free char *s_path = NULL;
gs_free char *d_path = NULL;
/* Failure; just use the existing leasefile */
_LOGW("failed to copy leasefile %s to %s: %s",
(s_path = g_file_get_path(src)),
(d_path = g_file_get_path(dst)),
local->message);
g_clear_error(&local);
} else {
/* Success; use the preferred leasefile path */
g_free(priv->lease_file);
priv->lease_file = g_file_get_path(dst);
}
}
/* Save the DUID to the leasefile dhclient will actually use */
if (addr_family == AF_INET6) {
if (!nm_dhcp_dhclient_save_duid(priv->lease_file,
nm_dhcp_client_get_client_id(client),
&local)) {
nm_utils_error_set(error,
NM_UTILS_ERROR_UNKNOWN,
"failed to save DUID to '%s': %s",
priv->lease_file,
local->message);
return FALSE;
}
}
argv = g_ptr_array_new();
g_ptr_array_add(argv, (gpointer) dhclient_path);
g_ptr_array_add(argv, (gpointer) "-d");
/* Be quiet. dhclient logs to syslog anyway. And we duplicate the syslog
* to stderr in case of NM running with --debug.
*/
g_ptr_array_add(argv, (gpointer) "-q");
if (release)
g_ptr_array_add(argv, (gpointer) "-r");
if (addr_family == AF_INET6) {
g_ptr_array_add(argv, (gpointer) "-6");
if (prefixes > 0 && nm_streq0(mode_opt, "-S")) {
/* -S is incompatible with -P, only use the latter */
mode_opt = NULL;
}
if (mode_opt)
g_ptr_array_add(argv, (gpointer) mode_opt);
while (prefixes--)
g_ptr_array_add(argv, (gpointer) "-P");
}
g_ptr_array_add(argv, (gpointer) "-sf"); /* Set script file */
g_ptr_array_add(argv, (gpointer) nm_dhcp_helper_path);
if (pid_file) {
g_ptr_array_add(argv, (gpointer) "-pf"); /* Set pid file */
g_ptr_array_add(argv, (gpointer) pid_file);
}
g_ptr_array_add(argv, (gpointer) "-lf"); /* Set lease file */
g_ptr_array_add(argv, (gpointer) priv->lease_file);
if (priv->conf_file) {
g_ptr_array_add(argv, (gpointer) "-cf"); /* Set interface config file */
g_ptr_array_add(argv, (gpointer) priv->conf_file);
}
/* Usually the system bus address is well-known; but if it's supposed
* to be something else, we need to push it to dhclient, since dhclient
* sanitizes the environment it gives the action scripts.
*/
system_bus_address = getenv("DBUS_SYSTEM_BUS_ADDRESS");
if (system_bus_address) {
system_bus_address_env = g_strdup_printf("DBUS_SYSTEM_BUS_ADDRESS=%s", system_bus_address);
g_ptr_array_add(argv, (gpointer) "-e");
g_ptr_array_add(argv, (gpointer) system_bus_address_env);
}
g_ptr_array_add(argv, (gpointer) iface);
g_ptr_array_add(argv, NULL);
_LOGD("running: %s", (cmd_str = g_strjoinv(" ", (char **) argv->pdata)));
if (!g_spawn_async(NULL,
(char **) argv->pdata,
NULL,
G_SPAWN_DO_NOT_REAP_CHILD | G_SPAWN_STDOUT_TO_DEV_NULL
| G_SPAWN_STDERR_TO_DEV_NULL,
nm_utils_setpgid,
NULL,
&pid,
&local)) {
nm_utils_error_set(error,
NM_UTILS_ERROR_UNKNOWN,
"dhclient failed to start: %s",
local->message);
return FALSE;
}
_LOGI("dhclient started with pid %lld", (long long int) pid);
if (!release)
nm_dhcp_client_watch_child(client, pid);
priv->pid_file = g_steal_pointer(&pid_file);
NM_SET_OUT(out_pid, pid);
return TRUE;
}
static gboolean
ip4_start(NMDhcpClient *client,
const char * dhcp_anycast_addr,
const char * last_ip4_address,
GError ** error)
{
NMDhcpDhclient * self = NM_DHCP_DHCLIENT(client);
NMDhcpDhclientPrivate *priv = NM_DHCP_DHCLIENT_GET_PRIVATE(self);
GBytes * client_id;
gs_unref_bytes GBytes *new_client_id = NULL;
client_id = nm_dhcp_client_get_client_id(client);
priv->conf_file = create_dhclient_config(self,
AF_INET,
nm_dhcp_client_get_iface(client),
nm_dhcp_client_get_uuid(client),
client_id,
dhcp_anycast_addr,
nm_dhcp_client_get_hostname(client),
nm_dhcp_client_get_timeout(client),
nm_dhcp_client_get_use_fqdn(client),
nm_dhcp_client_get_hostname_flags(client),
nm_dhcp_client_get_mud_url(client),
nm_dhcp_client_get_reject_servers(client),
&new_client_id);
if (!priv->conf_file) {
nm_utils_error_set_literal(error,
NM_UTILS_ERROR_UNKNOWN,
"error creating dhclient configuration file");
return FALSE;
}
if (new_client_id) {
nm_assert(!client_id);
nm_dhcp_client_set_client_id(client, new_client_id);
}
return dhclient_start(client, NULL, FALSE, NULL, 0, error);
}
static gboolean
ip6_start(NMDhcpClient * client,
const char * dhcp_anycast_addr,
const struct in6_addr * ll_addr,
NMSettingIP6ConfigPrivacy privacy,
guint needed_prefixes,
GError ** error)
{
NMDhcpDhclient * self = NM_DHCP_DHCLIENT(client);
NMDhcpDhclientPrivate *priv = NM_DHCP_DHCLIENT_GET_PRIVATE(self);
if (nm_dhcp_client_get_iaid_explicit(client))
_LOGW("dhclient does not support specifying an IAID for DHCPv6, it will be ignored");
priv->conf_file = create_dhclient_config(self,
AF_INET6,
nm_dhcp_client_get_iface(client),
nm_dhcp_client_get_uuid(client),
NULL,
dhcp_anycast_addr,
nm_dhcp_client_get_hostname(client),
nm_dhcp_client_get_timeout(client),
TRUE,
nm_dhcp_client_get_hostname_flags(client),
nm_dhcp_client_get_mud_url(client),
NULL,
NULL);
if (!priv->conf_file) {
nm_utils_error_set_literal(error,
NM_UTILS_ERROR_UNKNOWN,
"error creating dhclient configuration file");
return FALSE;
}
return dhclient_start(client,
nm_dhcp_client_get_info_only(NM_DHCP_CLIENT(self)) ? "-S" : "-N",
FALSE,
NULL,
needed_prefixes,
error);
}
static void
stop(NMDhcpClient *client, gboolean release)
{
NMDhcpDhclient * self = NM_DHCP_DHCLIENT(client);
NMDhcpDhclientPrivate *priv = NM_DHCP_DHCLIENT_GET_PRIVATE(self);
int errsv;
NM_DHCP_CLIENT_CLASS(nm_dhcp_dhclient_parent_class)->stop(client, release);
if (priv->conf_file)
if (remove(priv->conf_file) == -1) {
errsv = errno;
_LOGD("could not remove dhcp config file \"%s\": %d (%s)",
priv->conf_file,
errsv,
nm_strerror_native(errsv));
}
if (priv->pid_file) {
if (remove(priv->pid_file) == -1) {
errsv = errno;
_LOGD("could not remove dhcp pid file \"%s\": %s (%d)",
priv->pid_file,
nm_strerror_native(errsv),
errsv);
}
nm_clear_g_free(&priv->pid_file);
}
if (release) {
pid_t rpid = -1;
if (dhclient_start(client, NULL, TRUE, &rpid, 0, NULL)) {
/* Wait a few seconds for the release to happen */
nm_dhcp_client_stop_pid(rpid, nm_dhcp_client_get_iface(client));
}
}
}
static GBytes *
get_duid(NMDhcpClient *client)
{
NMDhcpDhclient * self = NM_DHCP_DHCLIENT(client);
NMDhcpDhclientPrivate *priv = NM_DHCP_DHCLIENT_GET_PRIVATE(self);
GBytes * duid = NULL;
gs_free char * leasefile = NULL;
GError * error = NULL;
/* Look in interface-specific leasefile first for backwards compat */
leasefile = get_dhclient_leasefile(AF_INET6,
nm_dhcp_client_get_iface(client),
nm_dhcp_client_get_uuid(client),
NULL);
if (leasefile) {
_LOGD("looking for DUID in '%s'", leasefile);
duid = nm_dhcp_dhclient_read_duid(leasefile, &error);
if (error) {
_LOGW("failed to read leasefile '%s': %s", leasefile, error->message);
g_clear_error(&error);
}
if (duid)
return duid;
}
/* Otherwise, read the default machine-wide DUID */
_LOGD("looking for default DUID in '%s'", priv->def_leasefile);
duid = nm_dhcp_dhclient_read_duid(priv->def_leasefile, &error);
if (error) {
_LOGW("failed to read leasefile '%s': %s", priv->def_leasefile, error->message);
g_clear_error(&error);
}
return duid;
}
/*****************************************************************************/
static void
nm_dhcp_dhclient_init(NMDhcpDhclient *self)
{
static const char *const FILES[] = {
SYSCONFDIR "/dhclient6.leases", /* default */
LOCALSTATEDIR "/lib/dhcp/dhclient6.leases",
LOCALSTATEDIR "/lib/dhclient/dhclient6.leases",
};
NMDhcpDhclientPrivate *priv = NM_DHCP_DHCLIENT_GET_PRIVATE(self);
int i;
priv->def_leasefile = FILES[0];
for (i = 0; i < G_N_ELEMENTS(FILES); i++) {
if (g_file_test(FILES[i], G_FILE_TEST_EXISTS)) {
priv->def_leasefile = FILES[i];
break;
}
}
priv->dhcp_listener = g_object_ref(nm_dhcp_listener_get());
g_signal_connect(priv->dhcp_listener,
NM_DHCP_LISTENER_EVENT,
G_CALLBACK(nm_dhcp_client_handle_event),
self);
}
static void
dispose(GObject *object)
{
NMDhcpDhclientPrivate *priv = NM_DHCP_DHCLIENT_GET_PRIVATE(object);
if (priv->dhcp_listener) {
g_signal_handlers_disconnect_by_func(priv->dhcp_listener,
G_CALLBACK(nm_dhcp_client_handle_event),
NM_DHCP_DHCLIENT(object));
g_clear_object(&priv->dhcp_listener);
}
nm_clear_g_free(&priv->pid_file);
nm_clear_g_free(&priv->conf_file);
nm_clear_g_free(&priv->lease_file);
G_OBJECT_CLASS(nm_dhcp_dhclient_parent_class)->dispose(object);
}
static void
nm_dhcp_dhclient_class_init(NMDhcpDhclientClass *dhclient_class)
{
NMDhcpClientClass *client_class = NM_DHCP_CLIENT_CLASS(dhclient_class);
GObjectClass * object_class = G_OBJECT_CLASS(dhclient_class);
object_class->dispose = dispose;
client_class->ip4_start = ip4_start;
client_class->ip6_start = ip6_start;
client_class->stop = stop;
client_class->get_duid = get_duid;
}
const NMDhcpClientFactory _nm_dhcp_client_factory_dhclient = {
.name = "dhclient",
.get_type = nm_dhcp_dhclient_get_type,
.get_path = nm_dhcp_dhclient_get_path,
};
#endif /* WITH_DHCLIENT */