--- /dev/null
+pppd: Fill in default gateway on Linux
+
+On Linux, when pppd creates the default route, it does not set the peer
+address as gateway, leading to a default route without gateway address.
+
+This behaviour breaks various downstream programs which attempt to infer
+the default gateway IP address from the system default route entry.
+
+This patch addresses the issue by filling in the peer address as gateway
+when generating the default route entry.
+
+Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>
+
+--- a/pppd/sys-linux.c
++++ b/pppd/sys-linux.c
+@@ -1697,6 +1697,9 @@ int sifdefaultroute (int unit, u_int32_t
+ memset (&rt, 0, sizeof (rt));
+ SET_SA_FAMILY (rt.rt_dst, AF_INET);
+
++ SET_SA_FAMILY(rt.rt_gateway, AF_INET);
++ SIN_ADDR(rt.rt_gateway) = gateway;
++
+ rt.rt_dev = ifname;
+
+ if (kernel_version > KVERSION(2,1,0)) {
+@@ -1704,7 +1707,7 @@ int sifdefaultroute (int unit, u_int32_t
+ SIN_ADDR(rt.rt_genmask) = 0L;
+ }
+
+- rt.rt_flags = RTF_UP;
++ rt.rt_flags = RTF_UP | RTF_GATEWAY;
+ if (ioctl(sock_fd, SIOCADDRT, &rt) < 0) {
+ if (!ok_error(errno))
+ error("default route ioctl(SIOCADDRT): %m");