From f72b63e92f040104a289d5f38047c3688fa76593 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Wed, 19 Oct 2022 11:43:50 +1100 Subject: [PATCH] Remove support for TCP packets from tap_ip_send() tap_ip_send() is never used for TCP packets, we're unlikely to use it for that in future, and the handling of TCP packets makes other cleanups unnecessarily awkward. Remove it. This is the only user of csum_tcp4(), so we can remove that as well. Signed-off-by: David Gibson Signed-off-by: Stefano Brivio --- checksum.c | 34 ---------------------------------- checksum.h | 1 - tap.c | 11 ++--------- 3 files changed, 2 insertions(+), 44 deletions(-) diff --git a/checksum.c b/checksum.c index 7b83196..09d2c7c 100644 --- a/checksum.c +++ b/checksum.c @@ -211,40 +211,6 @@ void csum_icmp6(struct icmp6hdr *icmp6hr, icmp6hr->icmp6_cksum = csum_unaligned(payload, len, psum); } -/** - * csum_tcp4() - Calculate TCP checksum for IPv4 and set in place - * @iph: Packet buffer, IP header - */ -void csum_tcp4(struct iphdr *iph) -{ - uint16_t tlen = ntohs(iph->tot_len) - iph->ihl * 4, *p; - struct tcphdr *th; - uint32_t sum = 0; - - th = (struct tcphdr *)((char *)iph + (intptr_t)(iph->ihl * 4)); - p = (uint16_t *)th; - - sum += (iph->saddr >> 16) & 0xffff; - sum += iph->saddr & 0xffff; - sum += (iph->daddr >> 16) & 0xffff; - sum += iph->daddr & 0xffff; - - sum += htons(IPPROTO_TCP); - sum += htons(tlen); - - th->check = 0; - while (tlen > 1) { - sum += *p++; - tlen -= 2; - } - - if (tlen > 0) { - sum += *p & htons(0xff00); - } - - th->check = (uint16_t)~csum_fold(sum); -} - #ifdef __AVX2__ #include diff --git a/checksum.h b/checksum.h index 91e9954..b87b0d6 100644 --- a/checksum.h +++ b/checksum.h @@ -23,7 +23,6 @@ void csum_udp6(struct udphdr *udp6hr, void csum_icmp6(struct icmp6hdr *icmp6hr, const struct in6_addr *saddr, const struct in6_addr *daddr, const void *payload, size_t len); -void csum_tcp4(struct iphdr *iph); uint16_t csum(const void *buf, size_t len, uint32_t init); #endif /* CHECKSUM_H */ diff --git a/tap.c b/tap.c index 89be383..844ee43 100644 --- a/tap.c +++ b/tap.c @@ -165,9 +165,7 @@ void tap_ip_send(const struct ctx *c, const struct in6_addr *src, uint8_t proto, memcpy(data, in, len); - if (iph->protocol == IPPROTO_TCP) { - csum_tcp4(iph); - } else if (iph->protocol == IPPROTO_UDP) { + if (iph->protocol == IPPROTO_UDP) { struct udphdr *uh = (struct udphdr *)(iph + 1); csum_udp4(uh, iph->saddr, iph->daddr, uh + 1, len - sizeof(*uh)); @@ -196,13 +194,8 @@ void tap_ip_send(const struct ctx *c, const struct in6_addr *src, uint8_t proto, ip6h->hop_limit = proto; ip6h->version = 0; ip6h->nexthdr = 0; - if (proto == IPPROTO_TCP) { - struct tcphdr *th = (struct tcphdr *)(ip6h + 1); - th->check = 0; - th->check = csum_unaligned(ip6h, len + sizeof(*ip6h), - 0); - } else if (proto == IPPROTO_UDP) { + if (proto == IPPROTO_UDP) { struct udphdr *uh = (struct udphdr *)(ip6h + 1); csum_udp6(uh, &ip6h->saddr, &ip6h->daddr,