Revision e454b591a84dc5465e252da91f65b20fba4d0bb5 authored by Chris Tarazi on 01 June 2021, 20:08:37 UTC, committed by André Martins on 07 June 2021, 12:23:03 UTC
[ upstream commit d620a92632610e293d03e248ac802c0a1177dfa7 ] The subsequent commit will add unit tests that make use of ipv{4,6}RouterAddress and state will need to be cleared during testing. Signed-off-by: Chris Tarazi <chris@isovalent.com> Signed-off-by: Paul Chaignon <paul@cilium.io>
1 parent 3378f8f
csum.h
/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (C) 2016-2020 Authors of Cilium */
#ifndef __LIB_CSUM_H_
#define __LIB_CSUM_H_
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/icmpv6.h>
#define TCP_CSUM_OFF (offsetof(struct tcphdr, check))
#define UDP_CSUM_OFF (offsetof(struct udphdr, check))
struct csum_offset {
__u16 offset;
__u16 flags;
};
/**
* Determins the L4 checksum field offset and required flags
* @arg nexthdr L3 nextheader field
* @arg off Pointer to uninitialied struct csum_offset struct
*
* Sets off.offset to offset from start of L4 header to L4 checksum field
* and off.flags to the required flags, namely BPF_F_MARK_MANGLED_0 for UDP.
* For unknown L4 protocols or L4 protocols which do not have a checksum
* field, off is initialied to 0.
*/
static __always_inline void csum_l4_offset_and_flags(__u8 nexthdr,
struct csum_offset *off)
{
switch (nexthdr) {
case IPPROTO_TCP:
off->offset = TCP_CSUM_OFF;
break;
case IPPROTO_UDP:
off->offset = UDP_CSUM_OFF;
off->flags = BPF_F_MARK_MANGLED_0;
break;
case IPPROTO_ICMPV6:
off->offset = offsetof(struct icmp6hdr, icmp6_cksum);
break;
case IPPROTO_ICMP:
break;
}
}
/**
* Helper to change L4 checksum
* @arg ctx Packet
* @arg l4_off Offset to L4 header
* @arg csum Pointer to csum_offset as extracted by csum_l4_offset_and_flags()
* @arg from From value or 0 if to contains csum diff
* @arg to To value or a csum diff
* @arg flags Additional flags to be passed to l4_csum_replace()
*/
static __always_inline int csum_l4_replace(struct __ctx_buff *ctx, __u64 l4_off,
const struct csum_offset *csum,
__be32 from, __be32 to, int flags)
{
return l4_csum_replace(ctx, l4_off + csum->offset, from, to, flags | csum->flags);
}
#endif /* __LB_H_ */
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