From 46b0c76e2c355c0d0cc4792abb98cde07b28bc53 Mon Sep 17 00:00:00 2001

From: Emil Renner Berthing <systemd@esmil.dk>

Date: Fri, 5 Sep 2014 11:56:02 +0200

Subject: [PATCH] networkd: add preferred source to dhcp4 gateway route

This makes DHCPv4 and IPv4LL coexist peacefully.

[tomegun: apply to both the dhcp routes, use in_addr_is_null() rather than a

separate variable to indicate when prefsrc should be applied]

---

 src/network/networkd-dhcp4.c | 11 +++++++++++

 src/network/networkd-route.c | 22 ++++++++++++++++++++++

 src/network/networkd.h       |  1 +

 3 files changed, 34 insertions(+)

diff --git a/src/network/networkd-dhcp4.c b/src/network/networkd-dhcp4.c

index 5e4ff2b80b..b87fa73082 100644

--- a/src/network/networkd-dhcp4.c

+++ b/src/network/networkd-dhcp4.c

@@ -67,9 +67,18 @@ static int link_set_dhcp_routes(Link *link) {

                 return r;

         }

         if (r >= 0) {

+                struct in_addr address;

                 _cleanup_route_free_ Route *route = NULL;

                 _cleanup_route_free_ Route *route_gw = NULL;

+                r = sd_dhcp_lease_get_address(link->dhcp_lease, &address);

+                if (r < 0) {

+                        log_warning_link(link,

+                                         "DHCP error: could not get address: %s",

+                                         strerror(-r));

+                        return r;

+                }

+

                 r = route_new_dynamic(&route, RTPROT_DHCP);

                 if (r < 0) {

                         log_error_link(link,

@@ -92,6 +101,7 @@ static int link_set_dhcp_routes(Link *link) {

                 route_gw->family = AF_INET;

                 route_gw->dst_addr.in = gateway;

                 route_gw->dst_prefixlen = 32;

+                route_gw->prefsrc_addr.in = address;

                 route_gw->scope = RT_SCOPE_LINK;

                 route_gw->metrics = DHCP_ROUTE_METRIC;

@@ -107,6 +117,7 @@ static int link_set_dhcp_routes(Link *link) {

                 route->family = AF_INET;

                 route->in_addr.in = gateway;

+                route->prefsrc_addr.in = address;

                 route->metrics = DHCP_ROUTE_METRIC;

                 r = route_configure(route, link, &dhcp4_route_handler);

diff --git a/src/network/networkd-route.c b/src/network/networkd-route.c

index aead4fbb9e..10d8cd902a 100644

--- a/src/network/networkd-route.c

+++ b/src/network/networkd-route.c

@@ -144,6 +144,17 @@ int route_drop(Route *route, Link *link,

                 }

         }

+        if (!in_addr_is_null(route->family, &route->prefsrc_addr)) {

+                if (route->family == AF_INET)

+                        r = sd_rtnl_message_append_in_addr(req, RTA_PREFSRC, &route->prefsrc_addr.in);

+                else if (route->family == AF_INET6)

+                        r = sd_rtnl_message_append_in6_addr(req, RTA_PREFSRC, &route->prefsrc_addr.in6);

+                if (r < 0) {

+                        log_error("Could not append RTA_PREFSRC attribute: %s", strerror(-r));

+                        return r;

+                }

+        }

+

         r = sd_rtnl_message_route_set_scope(req, route->scope);

         if (r < 0) {

                 log_error("Could not set scope: %s", strerror(-r));

@@ -218,6 +229,17 @@ int route_configure(Route *route, Link *link,

                 }

         }

+        if (!in_addr_is_null(route->family, &route->prefsrc_addr)) {

+                if (route->family == AF_INET)

+                        r = sd_rtnl_message_append_in_addr(req, RTA_PREFSRC, &route->prefsrc_addr.in);

+                else if (route->family == AF_INET6)

+                        r = sd_rtnl_message_append_in6_addr(req, RTA_PREFSRC, &route->prefsrc_addr.in6);

+                if (r < 0) {

+                        log_error("Could not append RTA_PREFSRC attribute: %s", strerror(-r));

+                        return r;

+                }

+        }

+

         r = sd_rtnl_message_route_set_scope(req, route->scope);

         if (r < 0) {

                 log_error("Could not set scope: %s", strerror(-r));

diff --git a/src/network/networkd.h b/src/network/networkd.h

index ab5df1aa3c..c6e6b22c38 100644

--- a/src/network/networkd.h

+++ b/src/network/networkd.h

@@ -150,6 +150,7 @@ struct Route {

         union in_addr_union in_addr;

         union in_addr_union dst_addr;

+        union in_addr_union prefsrc_addr;

         LIST_FIELDS(Route, routes);

 };