tools/testing/selftests/bpf/progs/test_sk_assign.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/bpf/progs/test_sk_assign.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/progs/test_sk_assign.c
Extension
.c
Size
4562 bytes
Lines
195
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019 Cloudflare Ltd.
// Copyright (c) 2020 Isovalent, Inc.

#include <stddef.h>
#include <stdbool.h>
#include <string.h>
#include <linux/bpf.h>
#include <linux/if_ether.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/pkt_cls.h>
#include <linux/tcp.h>
#include <sys/socket.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
#include "bpf_misc.h"

#if defined(IPROUTE2_HAVE_LIBBPF)
/* Use a new-style map definition. */
struct {
	__uint(type, BPF_MAP_TYPE_SOCKMAP);
	__type(key, int);
	__type(value, __u64);
	__uint(pinning, LIBBPF_PIN_BY_NAME);
	__uint(max_entries, 1);
} server_map SEC(".maps");
#else
/* Pin map under /sys/fs/bpf/tc/globals/<map name> */
#define PIN_GLOBAL_NS 2

/* Must match struct bpf_elf_map layout from iproute2 */
struct {
	__u32 type;
	__u32 size_key;
	__u32 size_value;
	__u32 max_elem;
	__u32 flags;
	__u32 id;
	__u32 pinning;
} server_map SEC("maps") = {
	.type = BPF_MAP_TYPE_SOCKMAP,
	.size_key = sizeof(int),
	.size_value  = sizeof(__u64),
	.max_elem = 1,
	.pinning = PIN_GLOBAL_NS,
};
#endif

char _license[] SEC("license") = "GPL";

/* Fill 'tuple' with L3 info, and attempt to find L4. On fail, return NULL. */
static inline struct bpf_sock_tuple *
get_tuple(struct __sk_buff *skb, bool *ipv4, bool *tcp)
{
	void *data_end = (void *)(long)skb->data_end;
	void *data = (void *)(long)skb->data;
	struct bpf_sock_tuple *result;
	struct ethhdr *eth;
	__u8 proto = 0;
	__u64 ihl_len;

	eth = (struct ethhdr *)(data);
	if (eth + 1 > data_end)
		return NULL;

	if (eth->h_proto == bpf_htons(ETH_P_IP)) {
		struct iphdr *iph = (struct iphdr *)(data + sizeof(*eth));

		if (iph + 1 > data_end)
			return NULL;
		if (iph->ihl != 5)
			/* Options are not supported */
			return NULL;
		ihl_len = iph->ihl * 4;
		proto = iph->protocol;
		*ipv4 = true;
		result = (struct bpf_sock_tuple *)&iph->saddr;
	} else if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
		struct ipv6hdr *ip6h = (struct ipv6hdr *)(data + sizeof(*eth));

		if (ip6h + 1 > data_end)
			return NULL;
		ihl_len = sizeof(*ip6h);
		proto = ip6h->nexthdr;
		*ipv4 = false;
		result = (struct bpf_sock_tuple *)&ip6h->saddr;
	} else {
		return (struct bpf_sock_tuple *)data;

Annotation

Implementation Notes