Commit 5d6d5cd1 authored by Dan Williams's avatar Dan Williams

dhclient: copy leasefiles from old location if needed (rh #916233) (bgo #696210)

When the default leasefile location got moved from distro-specific
dhclient locations to a single NM-specific location, that apparently
broke scripts and external tools that depended on the old location,
like dract netbooting.

During a netboot, DHCP is started from the initramfs and gets a
lease, and the leasefile lives in the initramfs.  When the real
system is started, and the rootfs switches from the initramfs to
the actual rootfs, something needs to copy the leasefiles over to
where NetworkManager can find them.  For dracut at least, various
dracut scripts were doing this, and copying to the old location
in /var/lib/dhclient or /var/lib/dhcp.  Which means NM can no
longer find them, and proceeds to acquire a new DHCP lease when
taking over the existing connection, rather than renewing the
existing lease.  This can lead to loss of network connectivity
and thus the netboot process fails.

If no leasefile for the connection in the new location exists,
look in the old locations and copy that leasefile over to the new
location.
parent 9e71bb3c
......@@ -24,7 +24,7 @@
#include <glib.h>
#include <glib/gi18n.h>
#include <dbus/dbus.h>
#include <gio/gio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
......@@ -79,13 +79,61 @@ nm_dhcp_dhclient_get_path (const char *try_first)
return *path;
}
/**
* get_dhclient_leasefile():
* @iface: the interface name of the device on which DHCP will be done
* @uuid: the connection UUID to which the returned lease should belong
* @ipv6: %TRUE for IPv6, %FALSE for IPv4
* @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 (const char * iface, const char *uuid, gboolean ipv6)
get_dhclient_leasefile (const char *iface,
const char *uuid,
gboolean ipv6,
char **out_preferred_path)
{
return g_strdup_printf (NMSTATEDIR "/dhclient%s-%s-%s.lease",
char *path;
/* /var/lib/NetworkManager is the preferred leasefile path */
path = g_strdup_printf (NMSTATEDIR "/dhclient%s-%s-%s.lease",
ipv6 ? "6" : "",
uuid,
iface);
if (out_preferred_path)
*out_preferred_path = g_strdup (path);
if (g_file_test (path, G_FILE_TEST_EXISTS))
return 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",
ipv6 ? "6" : "", uuid, iface);
if (g_file_test (path, G_FILE_TEST_EXISTS))
return path;
/* Old Red Hat and Fedora location */
g_free (path);
path = g_strdup_printf (LOCALSTATEDIR "/lib/dhclient/dhclient%s-%s-%s.lease",
ipv6 ? "6" : "", uuid, iface);
if (g_file_test (path, G_FILE_TEST_EXISTS))
return path;
/* Fail */
g_free (path);
return NULL;
}
static void
......@@ -141,7 +189,7 @@ nm_dhcp_dhclient_get_lease_config (const char *iface, const char *uuid, gboolean
if (ipv6)
return NULL;
leasefile = get_dhclient_leasefile (iface, uuid, FALSE);
leasefile = get_dhclient_leasefile (iface, uuid, FALSE, NULL);
if (!leasefile)
return NULL;
......@@ -457,7 +505,7 @@ dhclient_start (NMDHCPClient *client,
char *binary_name, *cmd_str, *pid_file = NULL, *system_bus_address_env = NULL;
gboolean ipv6, success;
guint log_domain;
char *escaped;
char *escaped, *preferred_leasefile_path = NULL;
g_return_val_if_fail (priv->pid_file == NULL, -1);
......@@ -488,7 +536,30 @@ dhclient_start (NMDHCPClient *client,
}
g_free (priv->lease_file);
priv->lease_file = get_dhclient_leasefile (iface, uuid, ipv6);
priv->lease_file = get_dhclient_leasefile (iface, uuid, ipv6, &preferred_leasefile_path);
if (!priv->lease_file) {
/* No existing leasefile, dhclient will create one at the preferred path */
priv->lease_file = g_strdup (preferred_leasefile_path);
} else if (g_strcmp0 (priv->lease_file, preferred_leasefile_path) != 0) {
GFile *src = g_file_new_for_path (priv->lease_file);
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, &error)) {
/* Success; use the preferred leasefile path */
g_free (priv->lease_file);
priv->lease_file = g_strdup (g_file_get_path (dst));
} else {
/* Failure; just use the existing leasefile */
nm_log_warn (log_domain, "Failed to copy leasefile %s to %s: (%d) %s",
g_file_get_path (src), g_file_get_path (dst),
error->code, error->message);
g_clear_error (&error);
}
g_object_unref (src);
g_object_unref (dst);
}
g_free (preferred_leasefile_path);
/* Save the DUID to the leasefile dhclient will actually use */
if (ipv6) {
......@@ -647,17 +718,18 @@ get_duid (NMDHCPClient *client)
/* Look in interface-specific leasefile first for backwards compat */
leasefile = get_dhclient_leasefile (nm_dhcp_client_get_iface (client),
nm_dhcp_client_get_uuid (client),
TRUE);
nm_log_dbg (LOGD_DHCP, "Looking for DHCPv6 DUID in '%s'.", leasefile);
duid = nm_dhcp_dhclient_read_duid (leasefile, &error);
g_free (leasefile);
TRUE,
NULL);
if (leasefile) {
nm_log_dbg (LOGD_DHCP, "Looking for DHCPv6 DUID in '%s'.", leasefile);
duid = nm_dhcp_dhclient_read_duid (leasefile, &error);
g_free (leasefile);
if (error) {
nm_log_warn (LOGD_DHCP, "Failed to read leasefile '%s': (%d) %s",
leasefile,
error ? error->code : -1,
error ? error->message : "(unknown)");
g_clear_error (&error);
if (error) {
nm_log_warn (LOGD_DHCP, "Failed to read leasefile '%s': (%d) %s",
leasefile, error->code, error->message);
g_clear_error (&error);
}
}
if (!duid && priv->def_leasefile) {
......
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