[ovs-dev] [PATCH V3 14/24] datapath: don't call pad_packet if not necessary
Greg Rose
gvrose8192 at gmail.com
Wed Sep 16 17:33:01 UTC 2020
From: Tonghao Zhang <xiangxia.m.yue at gmail.com>
Upstream commit:
commit 61ca533c0e94104c35fcb7858a23ec9a05d78143
Author: Tonghao Zhang <xiangxia.m.yue at gmail.com>
Date: Thu Nov 14 23:51:08 2019 +0800
net: openvswitch: don't call pad_packet if not necessary
The nla_put_u16/nla_put_u32 makes sure that
*attrlen is align. The call tree is that:
nla_put_u16/nla_put_u32
-> nla_put attrlen = sizeof(u16) or sizeof(u32)
-> __nla_put attrlen
-> __nla_reserve attrlen
-> skb_put(skb, nla_total_size(attrlen))
nla_total_size returns the total length of attribute
including padding.
Cc: Joe Stringer <joe at ovn.org>
Cc: William Tu <u9012063 at gmail.com>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue at gmail.com>
Acked-by: Pravin B Shelar <pshelar at ovn.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Cc: Tonghao Zhang <xiangxia.m.yue at gmail.com>
Reviewed-by: Tonghao Zhang <xiangxia.m.yue at gmail.com>
Signed-off-by: Greg Rose <gvrose8192 at gmail.com>
---
datapath/datapath.c | 22 ++++++++--------------
1 file changed, 8 insertions(+), 14 deletions(-)
diff --git a/datapath/datapath.c b/datapath/datapath.c
index f04ce210c..b9ac67635 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -512,23 +512,17 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
}
/* Add OVS_PACKET_ATTR_MRU */
- if (upcall_info->mru) {
- if (nla_put_u16(user_skb, OVS_PACKET_ATTR_MRU,
- upcall_info->mru)) {
- err = -ENOBUFS;
- goto out;
- }
- pad_packet(dp, user_skb);
+ if (upcall_info->mru &&
+ nla_put_u16(user_skb, OVS_PACKET_ATTR_MRU, upcall_info->mru)) {
+ err = -ENOBUFS;
+ goto out;
}
/* Add OVS_PACKET_ATTR_LEN when packet is truncated */
- if (cutlen > 0) {
- if (nla_put_u32(user_skb, OVS_PACKET_ATTR_LEN,
- skb->len)) {
- err = -ENOBUFS;
- goto out;
- }
- pad_packet(dp, user_skb);
+ if (cutlen > 0 &&
+ nla_put_u32(user_skb, OVS_PACKET_ATTR_LEN, skb->len)) {
+ err = -ENOBUFS;
+ goto out;
}
/* Add OVS_PACKET_ATTR_HASH */
--
2.17.1
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