Verified Commit a2abd15f authored by Roy Marples's avatar Roy Marples Committed by Thomas Haller
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DHCP: Support dhcpcd-9.x

This locks NM into dhcpcd-9.3.3 as that is the first version to support
the --noconfigure option. Older versions are no longer supported by NM
because they do modify the host which is undesirable.

Due to the way dhcpcd-9 uses privilege separation and that it re-parents
itself to PID 1, the main process cannot be reaped or waited for.
So we rely on dhcpcd correctly cleaning up after itself.
A new function nm_dhcp_client_stop_watch_child() has been added
so that dhcpcd can perform similar cleanup to the equivalent stop call.

As part of this change, the STOP and STOPPED reasons are mapped to
NM_DHCP_STATE_DONE and PREINIT is mapped to a new state NM_DHCP_STATE_NOOP
which means NM should just ignore this state.

!668
parent c1529dab
Pipeline #261791 passed with stages
in 40 minutes and 57 seconds
......@@ -13,6 +13,9 @@ USE AT YOUR OWN RISK. NOT RECOMMENDED FOR PRODUCTION USE!
the profile.
* Increase timeout of NetworkManager-wait-online.service to 60 seconds.
* Add "ipv4.dhcp-client-id=ipv6-duid" option for RFC4361.
* The dhcpcd plugin now requires a minimum version of dhcpcd-9.3.3 with
the --noconfigure option. Using an older version will cause dhcpcd to
exit with a status code of 1.
=============================================
NetworkManager-1.28
......
......@@ -367,10 +367,13 @@ reason_to_state(NMDhcpClient *self, const char *iface, const char *reason)
else if (g_ascii_strcasecmp(reason, "nak") == 0 || g_ascii_strcasecmp(reason, "expire") == 0
|| g_ascii_strcasecmp(reason, "expire6") == 0)
return NM_DHCP_STATE_EXPIRE;
else if (g_ascii_strcasecmp(reason, "end") == 0)
else if (g_ascii_strcasecmp(reason, "end") == 0 || g_ascii_strcasecmp(reason, "stop") == 0
|| g_ascii_strcasecmp(reason, "stopped") == 0)
return NM_DHCP_STATE_DONE;
else if (g_ascii_strcasecmp(reason, "fail") == 0 || g_ascii_strcasecmp(reason, "abend") == 0)
return NM_DHCP_STATE_FAIL;
else if (g_ascii_strcasecmp(reason, "preinit") == 0)
return NM_DHCP_STATE_NOOP;
_LOGD("unmapped DHCP state '%s'", reason);
return NM_DHCP_STATE_UNKNOWN;
......@@ -547,6 +550,18 @@ nm_dhcp_client_watch_child(NMDhcpClient *self, pid_t pid)
priv->watch_id = g_child_watch_add(pid, daemon_watch_cb, self);
}
void
nm_dhcp_client_stop_watch_child(NMDhcpClient *self, pid_t pid)
{
NMDhcpClientPrivate *priv = NM_DHCP_CLIENT_GET_PRIVATE(self);
g_return_if_fail(priv->pid == pid);
priv->pid = -1;
watch_cleanup(self);
timeout_cleanup(self);
}
gboolean
nm_dhcp_client_start_ip4(NMDhcpClient *self,
GBytes * client_id,
......@@ -874,6 +889,9 @@ nm_dhcp_client_handle_event(gpointer unused,
state_to_string(new_state),
reason);
if (new_state == NM_DHCP_STATE_NOOP)
return TRUE;
if (NM_IN_SET(new_state, NM_DHCP_STATE_BOUND, NM_DHCP_STATE_EXTENDED)) {
GVariantIter iter;
const char * name;
......
......@@ -55,6 +55,7 @@ typedef enum {
NM_DHCP_STATE_EXPIRE, /* lease expired or NAKed */
NM_DHCP_STATE_FAIL, /* failed for some reason */
NM_DHCP_STATE_TERMINATED, /* client is no longer running */
NM_DHCP_STATE_NOOP, /* state is a non operation for NetworkManager */
__NM_DHCP_STATE_MAX,
NM_DHCP_STATE_MAX = __NM_DHCP_STATE_MAX - 1,
} NMDhcpState;
......@@ -183,6 +184,8 @@ void nm_dhcp_client_start_timeout(NMDhcpClient *self);
void nm_dhcp_client_watch_child(NMDhcpClient *self, pid_t pid);
void nm_dhcp_client_stop_watch_child(NMDhcpClient *self, pid_t pid);
void nm_dhcp_client_set_state(NMDhcpClient *self,
NMDhcpState new_state,
NMIPConfig * ip_config,
......
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright (C) 2008 Roy Marples
* Copyright (C) 2008,2020 Roy Marples <roy@marples.name>
* Copyright (C) 2010 Dan Williams <dcbw@redhat.com>
*/
......@@ -40,7 +40,6 @@ static GType nm_dhcp_dhcpcd_get_type(void);
/*****************************************************************************/
typedef struct {
char * pid_file;
NMDhcpListener *dhcp_listener;
} NMDhcpDhcpcdPrivate;
......@@ -71,39 +70,37 @@ ip4_start(NMDhcpClient *client,
const char * last_ip4_address,
GError ** error)
{
NMDhcpDhcpcd * self = NM_DHCP_DHCPCD(client);
NMDhcpDhcpcdPrivate *priv = NM_DHCP_DHCPCD_GET_PRIVATE(self);
gs_unref_ptrarray GPtrArray *argv = NULL;
pid_t pid = -1;
GError * local = NULL;
gs_free char * cmd_str = NULL;
gs_free char * binary_name = NULL;
NMDhcpDhcpcd * self = NM_DHCP_DHCPCD(client);
gs_unref_ptrarray GPtrArray *argv = NULL;
pid_t pid;
GError * local;
gs_free char * cmd_str = NULL;
const char * iface;
const char * dhcpcd_path;
const char * hostname;
g_return_val_if_fail(priv->pid_file == NULL, FALSE);
pid = nm_dhcp_client_get_pid(client);
g_return_val_if_fail(pid == -1, FALSE);
iface = nm_dhcp_client_get_iface(client);
/* dhcpcd does not allow custom pidfiles; the pidfile is always
* RUNSTATEDIR "dhcpcd-<ifname>.pid".
*/
priv->pid_file = g_strdup_printf(RUNSTATEDIR "/dhcpcd-%s.pid", iface);
dhcpcd_path = nm_dhcp_dhcpcd_get_path();
if (!dhcpcd_path) {
nm_utils_error_set_literal(error, NM_UTILS_ERROR_UNKNOWN, "dhcpcd binary not found");
return FALSE;
}
/* Kill any existing dhcpcd from the pidfile */
binary_name = g_path_get_basename(dhcpcd_path);
nm_dhcp_client_stop_existing(priv->pid_file, binary_name);
argv = g_ptr_array_new();
g_ptr_array_add(argv, (gpointer) dhcpcd_path);
/* Don't configure anything, we will do that instead.
* This requires dhcpcd-9.3.3 or newer.
* Older versions only had an option not to install a default route,
* dhcpcd still added addresses and other routes so we no longer support that
* as it doesn't fit how NetworkManager wants to work.
*/
g_ptr_array_add(argv, (gpointer) "--noconfigure");
g_ptr_array_add(argv, (gpointer) "-B"); /* Don't background on lease (disable fork()) */
g_ptr_array_add(argv, (gpointer) "-K"); /* Disable built-in carrier detection */
......@@ -113,8 +110,6 @@ ip4_start(NMDhcpClient *client,
/* --noarp. Don't request or claim the address by ARP; this also disables IPv4LL. */
g_ptr_array_add(argv, (gpointer) "-A");
g_ptr_array_add(argv, (gpointer) "-G"); /* Let NM handle routing */
g_ptr_array_add(argv, (gpointer) "-c"); /* Set script file */
g_ptr_array_add(argv, (gpointer) nm_dhcp_helper_path);
......@@ -146,8 +141,8 @@ ip4_start(NMDhcpClient *client,
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,
G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL
| G_SPAWN_DO_NOT_REAP_CHILD,
nm_utils_setpgid,
NULL,
&pid,
......@@ -169,23 +164,32 @@ ip4_start(NMDhcpClient *client,
static void
stop(NMDhcpClient *client, gboolean release)
{
NMDhcpDhcpcd * self = NM_DHCP_DHCPCD(client);
NMDhcpDhcpcdPrivate *priv = NM_DHCP_DHCPCD_GET_PRIVATE(self);
int errsv;
NM_DHCP_CLIENT_CLASS(nm_dhcp_dhcpcd_parent_class)->stop(client, release);
if (priv->pid_file) {
if (remove(priv->pid_file) == -1) {
errsv = errno;
_LOGD("could not remove dhcp pid file \"%s\": %d (%s)",
priv->pid_file,
errsv,
nm_strerror_native(errsv));
}
NMDhcpDhcpcd *self = NM_DHCP_DHCPCD(client);
pid_t pid;
int sig, errsv;
pid = nm_dhcp_client_get_pid(client);
sig = release ? SIGALRM : SIGTERM;
_LOGD("sending %s to dhcpcd pid %d", sig == SIGALRM ? "SIGALRM" : "SIGTERM", pid);
/* dhcpcd-9.x features privilege separation.
* It's not our job to track all these processes so we rely on dhcpcd
* to always cleanup after itself.
* Because it also re-parents itself to PID 1, the process cannot be
* reaped or waited for.
* As such, just send the correct signal.
*/
if (kill(pid, sig) == -1) {
errsv = errno;
_LOGE("failed to kill dhcpcd %d:%s", errsv, strerror(errsv));
}
/* FIXME: implement release... */
/* When this function exits NM expects the PID to be -1.
* This means we also need to stop watching the pid.
* If we need to know the exit status then we need to refactor NM
* to allow a non -1 to mean we're waiting to exit still.
*/
nm_dhcp_client_stop_watch_child(client, pid);
}
/*****************************************************************************/
......@@ -214,8 +218,6 @@ dispose(GObject *object)
g_clear_object(&priv->dhcp_listener);
}
nm_clear_g_free(&priv->pid_file);
G_OBJECT_CLASS(nm_dhcp_dhcpcd_parent_class)->dispose(object);
}
......
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