diff mbox series

[net,v3,1/1] openvswitch: Fix setting ipv6 fields causing hw csum failure

Message ID 20220216135308.6354-1-paulb@nvidia.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series [net,v3,1/1] openvswitch: Fix setting ipv6 fields causing hw csum failure | expand

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netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/cc_maintainers fail 2 blamed authors not CCed: aatteka@nicira.com jesse@nicira.com; 2 maintainers not CCed: aatteka@nicira.com jesse@nicira.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 1 this patch: 1
netdev/checkpatch warning WARNING: line length of 82 exceeds 80 columns WARNING: line length of 84 exceeds 80 columns WARNING: line length of 86 exceeds 80 columns WARNING: line length of 90 exceeds 80 columns WARNING: line length of 94 exceeds 80 columns WARNING: line length of 95 exceeds 80 columns WARNING: line length of 96 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Paul Blakey Feb. 16, 2022, 1:53 p.m. UTC 
Ipv6 ttl, label and tos fields are modified without first
pulling/pushing the ipv6 header, which would have updated
the hw csum (if available). This might cause csum validation
when sending the packet to the stack, as can be seen in
the trace below.

Fix this by updating skb->csum if available.

Trace resulted by ipv6 ttl dec and then sending packet
to conntrack [actions: set(ipv6(hlimit=63)),ct(zone=99)]:
[295241.900063] s_pf0vf2: hw csum failure
[295241.923191] Call Trace:
[295241.925728]  <IRQ>
[295241.927836]  dump_stack+0x5c/0x80
[295241.931240]  __skb_checksum_complete+0xac/0xc0
[295241.935778]  nf_conntrack_tcp_packet+0x398/0xba0 [nf_conntrack]
[295241.953030]  nf_conntrack_in+0x498/0x5e0 [nf_conntrack]
[295241.958344]  __ovs_ct_lookup+0xac/0x860 [openvswitch]
[295241.968532]  ovs_ct_execute+0x4a7/0x7c0 [openvswitch]
[295241.979167]  do_execute_actions+0x54a/0xaa0 [openvswitch]
[295242.001482]  ovs_execute_actions+0x48/0x100 [openvswitch]
[295242.006966]  ovs_dp_process_packet+0x96/0x1d0 [openvswitch]
[295242.012626]  ovs_vport_receive+0x6c/0xc0 [openvswitch]
[295242.028763]  netdev_frame_hook+0xc0/0x180 [openvswitch]
[295242.034074]  __netif_receive_skb_core+0x2ca/0xcb0
[295242.047498]  netif_receive_skb_internal+0x3e/0xc0
[295242.052291]  napi_gro_receive+0xba/0xe0
[295242.056231]  mlx5e_handle_rx_cqe_mpwrq_rep+0x12b/0x250 [mlx5_core]
[295242.062513]  mlx5e_poll_rx_cq+0xa0f/0xa30 [mlx5_core]
[295242.067669]  mlx5e_napi_poll+0xe1/0x6b0 [mlx5_core]
[295242.077958]  net_rx_action+0x149/0x3b0
[295242.086762]  __do_softirq+0xd7/0x2d6
[295242.090427]  irq_exit+0xf7/0x100
[295242.093748]  do_IRQ+0x7f/0xd0
[295242.096806]  common_interrupt+0xf/0xf
[295242.100559]  </IRQ>
[295242.102750] RIP: 0033:0x7f9022e88cbd
[295242.125246] RSP: 002b:00007f9022282b20 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffda
[295242.132900] RAX: 0000000000000005 RBX: 0000000000000010 RCX: 0000000000000000
[295242.140120] RDX: 00007f9022282ba8 RSI: 00007f9022282a30 RDI: 00007f9014005c30
[295242.147337] RBP: 00007f9014014d60 R08: 0000000000000020 R09: 00007f90254a8340
[295242.154557] R10: 00007f9022282a28 R11: 0000000000000246 R12: 0000000000000000
[295242.161775] R13: 00007f902308c000 R14: 000000000000002b R15: 00007f9022b71f40

Fixes: 3fdbd1ce11e5 ("openvswitch: add ipv6 'set' action")
Signed-off-by: Paul Blakey <paulb@nvidia.com>
---
 Changelog:
    v2->v3:
      Use u8 instead of __u8
      Fix sparse warnings on conversions
    v1->v2:
      Replaced push pull rcsum checksum calc with actual checksum calc

 net/openvswitch/actions.c | 51 +++++++++++++++++++++++++++++++++------
 1 file changed, 43 insertions(+), 8 deletions(-)

Comments

Jakub Kicinski Feb. 17, 2022, 5:42 p.m. UTC | #1 
On Wed, 16 Feb 2022 15:53:08 +0200 Paul Blakey wrote:
> +		skb->csum =
> +			~csum_block_add(csum_block_sub(~skb->csum,
> +						       (__force __wsum) (ipv6_tclass << 4), 1),
> +					(__force __wsum) (old_ipv6_tclass << 4), 1);

Please add a wcsum_replace4() helper to include/net/checksum.h
It should work like the (misnamed) csum_relace4() helper and have
similar params just wsum instead of sum16.
diff mbox series

Patch

diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 076774034bb9..02c63308433a 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -423,12 +423,48 @@  static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
 	memcpy(addr, new_addr, sizeof(__be32[4]));
 }
 
-static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl, u32 mask)
+static void set_ipv6_dsfield(struct sk_buff *skb, struct ipv6hdr *nh, u8 ipv6_tclass, u8 mask)
 {
+	u8 old_ipv6_tclass = ipv6_get_dsfield(nh);
+
+	ipv6_tclass = OVS_MASKED(old_ipv6_tclass, ipv6_tclass, mask);
+
+	if (skb->ip_summed == CHECKSUM_COMPLETE)
+		skb->csum =
+			~csum_block_add(csum_block_sub(~skb->csum,
+						       (__force __wsum) (ipv6_tclass << 4), 1),
+					(__force __wsum) (old_ipv6_tclass << 4), 1);
+
+	ipv6_change_dsfield(nh, ~mask, ipv6_tclass);
+}
+
+static void set_ipv6_fl(struct sk_buff *skb, struct ipv6hdr *nh, u32 fl, u32 mask)
+{
+	u32 old_fl;
+
+	old_fl = nh->flow_lbl[0] << 16 |  nh->flow_lbl[1] << 8 |  nh->flow_lbl[2];
+	fl = OVS_MASKED(old_fl, fl, mask);
+
 	/* Bits 21-24 are always unmasked, so this retains their values. */
-	OVS_SET_MASKED(nh->flow_lbl[0], (u8)(fl >> 16), (u8)(mask >> 16));
-	OVS_SET_MASKED(nh->flow_lbl[1], (u8)(fl >> 8), (u8)(mask >> 8));
-	OVS_SET_MASKED(nh->flow_lbl[2], (u8)fl, (u8)mask);
+	nh->flow_lbl[0] = (u8)(fl >> 16);
+	nh->flow_lbl[1] = (u8)(fl >> 8);
+	nh->flow_lbl[2] = (u8)fl;
+
+	if (skb->ip_summed == CHECKSUM_COMPLETE)
+		skb->csum = ~csum_block_add(csum_block_sub(~skb->csum,
+							   (__force __wsum) htonl(fl), 0),
+					    (__force __wsum) htonl(old_fl), 0);
+}
+
+static void set_ipv6_ttl(struct sk_buff *skb, struct ipv6hdr *nh, u8 new_ttl, u8 mask)
+{
+	new_ttl = OVS_MASKED(nh->hop_limit, new_ttl, mask);
+
+	if (skb->ip_summed == CHECKSUM_COMPLETE)
+		skb->csum = ~csum_block_add(csum_block_sub(~skb->csum, (__force __wsum) new_ttl,
+							   1),
+					    (__force __wsum) nh->hop_limit, 1);
+	nh->hop_limit = new_ttl;
 }
 
 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl,
@@ -546,18 +582,17 @@  static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *flow_key,
 		}
 	}
 	if (mask->ipv6_tclass) {
-		ipv6_change_dsfield(nh, ~mask->ipv6_tclass, key->ipv6_tclass);
+		set_ipv6_dsfield(skb, nh, key->ipv6_tclass, mask->ipv6_tclass);
 		flow_key->ip.tos = ipv6_get_dsfield(nh);
 	}
 	if (mask->ipv6_label) {
-		set_ipv6_fl(nh, ntohl(key->ipv6_label),
+		set_ipv6_fl(skb, nh, ntohl(key->ipv6_label),
 			    ntohl(mask->ipv6_label));
 		flow_key->ipv6.label =
 		    *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
 	}
 	if (mask->ipv6_hlimit) {
-		OVS_SET_MASKED(nh->hop_limit, key->ipv6_hlimit,
-			       mask->ipv6_hlimit);
+		set_ipv6_ttl(skb, nh, key->ipv6_hlimit, mask->ipv6_hlimit);
 		flow_key->ip.ttl = nh->hop_limit;
 	}
 	return 0;