diff options
| author | Eric Dumazet <edumazet@google.com> | 2026-02-04 05:30:23 +0000 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2026-02-05 16:33:52 +0100 |
| commit | 7a4cd71fa4514cd85df39b3cf99da8142660cdcd (patch) | |
| tree | cf3759770b1b3e173aa3c4917850e171424ab724 /net | |
| parent | 770e112634e73349abb5b021ff9735dc18a4f176 (diff) | |
net: add vlan_get_protocol_offset_inline() helper
skb_protocol() is bloated, and forces slow stack canaries in many
fast paths.
Add vlan_get_protocol_offset_inline() which deals with the non-vlan
common cases.
__vlan_get_protocol_offset() is now out of line.
It returns a vlan_type_depth struct to avoid stack canaries in callers.
struct vlan_type_depth {
__be16 type;
u16 depth;
};
$ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
add/remove: 0/2 grow/shrink: 0/22 up/down: 0/-6320 (-6320)
Function old new delta
vlan_get_protocol_dgram 61 59 -2
__pfx_skb_protocol 16 - -16
__vlan_get_protocol_offset 307 273 -34
tap_get_user 1374 1207 -167
ip_md_tunnel_xmit 1625 1452 -173
tap_sendmsg 940 753 -187
netif_skb_features 1079 866 -213
netem_enqueue 3017 2800 -217
vlan_parse_protocol 271 50 -221
tso_start 567 344 -223
fq_dequeue 1908 1685 -223
skb_network_protocol 434 205 -229
ip6_tnl_xmit 2639 2409 -230
br_dev_queue_push_xmit 474 236 -238
skb_protocol 258 - -258
packet_parse_headers 621 357 -264
__ip6_tnl_rcv 1306 1039 -267
skb_csum_hwoffload_help 515 224 -291
ip_tunnel_xmit 2635 2339 -296
sch_frag_xmit_hook 1582 1233 -349
bpf_skb_ecn_set_ce 868 457 -411
IP6_ECN_decapsulate 1297 768 -529
ip_tunnel_rcv 2121 1489 -632
ipip6_rcv 2572 1922 -650
Total: Before=24892803, After=24886483, chg -0.03%
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260204053023.1622775-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/skbuff.c | 36 | ||||
| -rw-r--r-- | net/packet/af_packet.c | 5 |
2 files changed, 39 insertions, 2 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 648c20e19038..45809986dfe1 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -7444,3 +7444,39 @@ void __put_netmem(netmem_ref netmem) net_devmem_put_net_iov(netmem_to_net_iov(netmem)); } EXPORT_SYMBOL(__put_netmem); + +struct vlan_type_depth __vlan_get_protocol_offset(const struct sk_buff *skb, + __be16 type, + int mac_offset) +{ + unsigned int vlan_depth = skb->mac_len, parse_depth = VLAN_MAX_DEPTH; + + /* if type is 802.1Q/AD then the header should already be + * present at mac_len - VLAN_HLEN (if mac_len > 0), or at + * ETH_HLEN otherwise + */ + if (vlan_depth) { + if (WARN_ON_ONCE(vlan_depth < VLAN_HLEN)) + return (struct vlan_type_depth) { 0 }; + vlan_depth -= VLAN_HLEN; + } else { + vlan_depth = ETH_HLEN; + } + do { + struct vlan_hdr vhdr, *vh; + + vh = skb_header_pointer(skb, mac_offset + vlan_depth, + sizeof(vhdr), &vhdr); + if (unlikely(!vh || !--parse_depth)) + return (struct vlan_type_depth) { 0 }; + + type = vh->h_vlan_encapsulated_proto; + vlan_depth += VLAN_HLEN; + } while (eth_type_vlan(type)); + + return (struct vlan_type_depth) { + .type = type, + .depth = vlan_depth + }; +} +EXPORT_SYMBOL(__vlan_get_protocol_offset); diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 494d628d10a5..a1005359085a 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -572,8 +572,9 @@ static __be16 vlan_get_protocol_dgram(const struct sk_buff *skb) __be16 proto = skb->protocol; if (unlikely(eth_type_vlan(proto))) - proto = __vlan_get_protocol_offset(skb, proto, - skb_mac_offset(skb), NULL); + proto = vlan_get_protocol_offset_inline(skb, proto, + skb_mac_offset(skb), + NULL); return proto; } |