From d97f11590a0f60cd911ace8bb68180b5a09a068d Mon Sep 17 00:00:00 2001 From: Guishan Qin Date: Fri, 11 Dec 2020 17:35:11 +0800 Subject: [PATCH] net: checksum: Add IP header checksum calculation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit At present net_checksum_calculate() only calculates TCP/UDP checksum in an IP packet, but assumes the IP header checksum to be provided by the software, e.g.: Linux kernel always calculates the IP header checksum. However this might not always be the case, e.g.: for an IP checksum offload enabled stack like VxWorks, the IP header checksum can be zero. This adds the checksum calculation of the IP header. Signed-off-by: Guishan Qin Signed-off-by: Yabing Liu Signed-off-by: Bin Meng Reviewed-by: Cédric Le Goater Signed-off-by: Jason Wang --- net/checksum.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/checksum.c b/net/checksum.c index 5cb8b2c368..dabd290c64 100644 --- a/net/checksum.c +++ b/net/checksum.c @@ -61,6 +61,7 @@ void net_checksum_calculate(uint8_t *data, int length) { int mac_hdr_len, ip_len; struct ip_header *ip; + uint16_t csum; /* * Note: We cannot assume "data" is aligned, so the all code uses @@ -106,6 +107,11 @@ void net_checksum_calculate(uint8_t *data, int length) return; /* not IPv4 */ } + /* Calculate IP checksum */ + stw_he_p(&ip->ip_sum, 0); + csum = net_raw_checksum((uint8_t *)ip, IP_HDR_GET_LEN(ip)); + stw_be_p(&ip->ip_sum, csum); + if (IP4_IS_FRAGMENT(ip)) { return; /* a fragmented IP packet */ } @@ -122,7 +128,6 @@ void net_checksum_calculate(uint8_t *data, int length) switch (ip->ip_p) { case IP_PROTO_TCP: { - uint16_t csum; tcp_header *tcp = (tcp_header *)(ip + 1); if (ip_len < sizeof(tcp_header)) { @@ -143,7 +148,6 @@ void net_checksum_calculate(uint8_t *data, int length) } case IP_PROTO_UDP: { - uint16_t csum; udp_header *udp = (udp_header *)(ip + 1); if (ip_len < sizeof(udp_header)) {