From b5799eeb0787deacb30d5984f6ac78f88f23b97e Mon Sep 17 00:00:00 2001
From: Susant Sahani <ssahani@redhat.com>
Date: Mon, 29 Apr 2019 10:32:34 +0530
Subject: [PATCH] networkd: Add back static routes after DHCPv4 lease expires.

1. When the DHCPv4 lease expires kernel removes the route. So add it back
when we gain lease again.

Closes https://github.com/systemd/systemd/issues/12426

2. When UseRoutes=false do not remove router
---
 src/network/networkd-dhcp4.c | 9 ++++++---
 src/network/networkd-link.c  | 2 +-
 src/network/networkd-link.h  | 1 +
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/network/networkd-dhcp4.c b/src/network/networkd-dhcp4.c
index 9ea49b0..301d9c6 100644
--- a/src/network/networkd-dhcp4.c
+++ b/src/network/networkd-dhcp4.c
@@ -214,10 +214,7 @@ static int dhcp_lease_lost(Link *link) {
                                 }
                         }
                 }
-        }
 
-        r = address_new(&address);
-        if (r >= 0) {
                 r = sd_dhcp_lease_get_router(link->dhcp_lease, &router);
                 if (r > 0 && !in4_addr_is_null(&router[0])) {
                         _cleanup_(route_freep) Route *route_gw = NULL;
@@ -241,7 +238,10 @@ static int dhcp_lease_lost(Link *link) {
                                 route_remove(route, link, NULL);
                         }
                 }
+        }
 
+        r = address_new(&address);
+        if (r >= 0) {
                 r = sd_dhcp_lease_get_address(link->dhcp_lease, &addr);
                 if (r >= 0) {
                         r = sd_dhcp_lease_get_netmask(link->dhcp_lease, &netmask);
@@ -308,6 +308,9 @@ static int dhcp4_address_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *
 
         link_set_dhcp_routes(link);
 
+        /* Add back static routes since kernel removes while DHCPv4 address is removed from when lease expires */
+        link_request_set_routes(link);
+
         if (link->dhcp4_messages == 0) {
                 link->dhcp4_configured = true;
                 link_check_ready(link);
diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index 567df73..3e22efb 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -913,7 +913,7 @@ static int route_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
         return 1;
 }
 
-static int link_request_set_routes(Link *link) {
+int link_request_set_routes(Link *link) {
         enum {
                 PHASE_NON_GATEWAY, /* First phase: Routes without a gateway */
                 PHASE_GATEWAY,     /* Second phase: Routes with a gateway */
diff --git a/src/network/networkd-link.h b/src/network/networkd-link.h
index e549737..7d8808e 100644
--- a/src/network/networkd-link.h
+++ b/src/network/networkd-link.h
@@ -180,6 +180,7 @@ int link_send_changed(Link *link, const char *property, ...) _sentinel_;
 uint32_t link_get_vrf_table(Link *link);
 uint32_t link_get_dhcp_route_table(Link *link);
 uint32_t link_get_ipv6_accept_ra_route_table(Link *link);
+int link_request_set_routes(Link *link);
 
 #define ADDRESS_FMT_VAL(address)                   \
         be32toh((address).s_addr) >> 24,           \
-- 
2.7.4