socket: set ignore_df=1 on xmit

This allows the kernel to generate ipv6 fragments. Apply the same to ipv4 for consistency. Signed-off-by: Joe Holden <[email protected]>
WireGuard · May 12, 2019 · 8416093 · 8416093
1 parent 3b8affc
commit 8416093
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Showing 2 changed files with 6 additions and 0 deletions.
diff --git a/src/compat/compat.h b/src/compat/compat.h
@@ -778,6 +778,9 @@ struct __kernel_timespec {
 #define skb_probe_transport_header(a) skb_probe_transport_header(a, 0)
 #endif
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 16, 0) && !defined(ISRHEL7)
+#define ignore_df local_df
+#endif
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(5, 1, 0)
 /* Note that all intentional uses of the non-_bh variety need to explicitly

diff --git a/src/socket.c b/src/socket.c
@@ -86,6 +86,8 @@ static int send4(struct wg_device *wg, struct sk_buff *skb,
 		if (cache)
 			dst_cache_set_ip4(cache, &rt->dst, fl.saddr);
 	}
+
+	skb->ignore_df = 1;
 	udp_tunnel_xmit_skb(rt, sock, skb, fl.saddr, fl.daddr, ds,
 			    ip4_dst_hoplimit(&rt->dst), 0, fl.fl4_sport,
 			    fl.fl4_dport, false, false);
@@ -157,6 +159,7 @@ static int send6(struct wg_device *wg, struct sk_buff *skb,
 			dst_cache_set_ip6(cache, dst, &fl.saddr);
 	}
 
+	skb->ignore_df = 1;
 	udp_tunnel6_xmit_skb(dst, sock, skb, skb->dev, &fl.saddr, &fl.daddr, ds,
 			     ip6_dst_hoplimit(dst), 0, fl.fl6_sport,
 			     fl.fl6_dport, false);