sched: act_csum: don't mangle TCP and UDP GSO packets (add641e7) · Commits · 戴 / test

after act_csum computes the checksum on skbs carrying GSO TCP/UDP packets, subsequent segmentation fails because skb_needs_check(skb, true) returns true. Because of that, skb_warn_bad_offload() is invoked and the following message is displayed: WARNING: CPU: 3 PID: 28 at net/core/dev.c:2553 skb_warn_bad_offload+0xf0/0xfd <...> [<ffffffff8171f486>] skb_warn_bad_offload+0xf0/0xfd [<ffffffff8161304c>] __skb_gso_segment+0xec/0x110 [<ffffffff8161340d>] validate_xmit_skb+0x12d/0x2b0 [<ffffffff816135d2>] validate_xmit_skb_list+0x42/0x70 [<ffffffff8163c560>] sch_direct_xmit+0xd0/0x1b0 [<ffffffff8163c760>] __qdisc_run+0x120/0x270 [<ffffffff81613b3d>] __dev_queue_xmit+0x23d/0x690 [<ffffffff81613fa0>] dev_queue_xmit+0x10/0x20 Since GSO is able to compute checksum on individual segments of such skbs, we can simply skip mangling the packet. Signed-off-by:

Davide Caratti <dcaratti@redhat.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/sched/act_csum.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -181,6 +181,9 @@ static int tcf_csum_ipv4_tcp(struct sk_buff *skb, unsigned int ihl,
		struct tcphdr *tcph;
		const struct iphdr *iph;

		if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
		return 1;

		tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
		if (tcph == NULL)
		return 0;
		@@ -202,6 +205,9 @@ static int tcf_csum_ipv6_tcp(struct sk_buff *skb, unsigned int ihl,
		struct tcphdr *tcph;
		const struct ipv6hdr *ip6h;

		if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
		return 1;

		tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
		if (tcph == NULL)
		return 0;
		@@ -225,6 +231,9 @@ static int tcf_csum_ipv4_udp(struct sk_buff *skb, unsigned int ihl,
		const struct iphdr *iph;
		u16 ul;

		if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
		return 1;

		/*
		* Support both UDP and UDPLITE checksum algorithms, Don't use
		* udph->len to get the real length without any protocol check,
		@@ -278,6 +287,9 @@ static int tcf_csum_ipv6_udp(struct sk_buff *skb, unsigned int ihl,
		const struct ipv6hdr *ip6h;
		u16 ul;

		if (skb_is_gso(skb) && skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
		return 1;

		/*
		* Support both UDP and UDPLITE checksum algorithms, Don't use
		* udph->len to get the real length without any protocol check,

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