netdev - [PATCH RFC 5/5] net: set DF bit on fragment list skbs if DF was set earlier

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1430772888-5682-6-git-send-email-fw@strlen.de>
Date:	Mon,  4 May 2015 22:54:48 +0200
From:	Florian Westphal <fw@...len.de>
To:	<netdev@...r.kernel.org>
Cc:	hannes@...essinduktion.org, jesse@...ira.com,
	Florian Westphal <fw@...len.de>
Subject: [PATCH RFC 5/5] net: set DF bit on fragment list skbs if DF was set earlier

This extends the previous change to also set the DF bit in the
fragment list skb, i.e. if the original fragments had DF set,
then also set it when 'replaying' the fraglist skbs.

Signed-off-by: Florian Westphal <fw@...len.de>
---
 net/ipv4/ip_output.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 26847e4..3a41844 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -543,6 +543,7 @@ int ip_fragment(struct sock *sk, struct sk_buff *skb,
 	if (skb_has_frag_list(skb)) {
 		struct sk_buff *frag, *frag2;
 		int first_len = skb_pagelen(skb);
+		bool is_df_skb;
 
 		if (first_len - hlen > mtu ||
 		    ((first_len - hlen) & 7) ||
@@ -579,6 +580,9 @@ int ip_fragment(struct sock *sk, struct sk_buff *skb,
 		skb->len = first_len;
 		iph->tot_len = htons(first_len);
 		iph->frag_off = htons(IP_MF);
+		is_df_skb = IPCB(skb)->flags & IPSKB_FRAG_PMTU;
+		if (is_df_skb)
+			iph->frag_off |= htons(IP_DF);
 		ip_send_check(iph);
 
 		for (;;) {
@@ -599,6 +603,8 @@ int ip_fragment(struct sock *sk, struct sk_buff *skb,
 				iph->frag_off = htons(offset>>3);
 				if (frag->next)
 					iph->frag_off |= htons(IP_MF);
+				if (is_df_skb)
+					iph->frag_off |= htons(IP_DF);
 				/* Ready, complete checksum */
 				ip_send_check(iph);
 			}
-- 
2.0.5

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html