From 9a79a1ab931c3b5a7ae07d6f0fcfef7c4368a2c4 Mon Sep 17 00:00:00 2001 From: Damjan Marion Date: Mon, 31 Aug 2020 19:54:19 +0200 Subject: [PATCH] ip: improve ip4_header_checksum_is_valid It is cheaper to include checksum field in calculation and simply compare result with zero. Type: improvement Change-Id: I6f77632c0a4d2f2c632d044d3a5d2fcf2b5bac62 Signed-off-by: Damjan Marion --- src/vnet/ip/ip4_packet.h | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/src/vnet/ip/ip4_packet.h b/src/vnet/ip/ip4_packet.h index 6abb6a9ebf0..06530926120 100644 --- a/src/vnet/ip/ip4_packet.h +++ b/src/vnet/ip/ip4_packet.h @@ -205,8 +205,8 @@ ip4_next_header (ip4_header_t * i) WARN_OFF(array-bounds) /* *INDENT-ON* */ -always_inline u16 -ip4_header_checksum (ip4_header_t * i) +static_always_inline u16 +ip4_header_checksum_inline (ip4_header_t * i, int with_checksum) { int option_len = (i->ip_version_and_header_length & 0xf) - 5; uword sum = 0; @@ -215,7 +215,7 @@ ip4_header_checksum (ip4_header_t * i) sum += iphdr[0]; sum += iphdr[1]; - sum += *(u16 *) (iphdr + 2); + sum += with_checksum ? iphdr[2] : *(u16 *) (iphdr + 2); /* skip checksum */ sum += iphdr[3]; sum += iphdr[4]; @@ -256,7 +256,8 @@ ip4_header_checksum (ip4_header_t * i) sum += iphdr[2]; sum += iphdr[3]; sum += iphdr[4]; - /* skip checksum */ + if (with_checksum) + sum += iphdr[5]; sum += iphdr[6]; sum += iphdr[7]; sum += iphdr[8]; @@ -309,6 +310,12 @@ ip4_header_checksum (ip4_header_t * i) WARN_ON(array-bounds) /* *INDENT-ON* */ +always_inline u16 +ip4_header_checksum (ip4_header_t * i) +{ + return ip4_header_checksum_inline (i, /* with_checksum */ 0); +} + always_inline void ip4_header_set_dscp (ip4_header_t * ip4, ip_dscp_t dscp) { @@ -376,7 +383,7 @@ ip4_header_get_df (const ip4_header_t * ip4) static inline uword ip4_header_checksum_is_valid (ip4_header_t * i) { - return i->checksum == ip4_header_checksum (i); + return ip4_header_checksum_inline (i, /* with_checksum */ 1) == 0; } #define ip4_partial_header_checksum_x1(ip0,sum0) \ -- 2.16.6