tools/testing/selftests/bpf/progs/test_lwt_seg6local.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/bpf/progs/test_lwt_seg6local.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/progs/test_lwt_seg6local.c
Extension
.c
Size
9964 bytes
Lines
429
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

struct ip6_t {
	unsigned int ver:4;
	unsigned int priority:8;
	unsigned int flow_label:20;
	unsigned short payload_len;
	unsigned char next_header;
	unsigned char hop_limit;
	unsigned long long src_hi;
	unsigned long long src_lo;
	unsigned long long dst_hi;
	unsigned long long dst_lo;
} BPF_PACKET_HEADER;

struct ip6_addr_t {
	unsigned long long hi;
	unsigned long long lo;
} BPF_PACKET_HEADER;

struct ip6_srh_t {
	unsigned char nexthdr;
	unsigned char hdrlen;
	unsigned char type;
	unsigned char segments_left;
	unsigned char first_segment;
	unsigned char flags;
	unsigned short tag;

	struct ip6_addr_t segments[0];
} BPF_PACKET_HEADER;

struct sr6_tlv_t {
	unsigned char type;
	unsigned char len;
	unsigned char value[0];
} BPF_PACKET_HEADER;

static __always_inline struct ip6_srh_t *get_srh(struct __sk_buff *skb)
{
	void *cursor, *data_end;
	struct ip6_srh_t *srh;
	struct ip6_t *ip;
	uint8_t *ipver;

	data_end = (void *)(long)skb->data_end;
	cursor = (void *)(long)skb->data;
	ipver = (uint8_t *)cursor;

	if ((void *)ipver + sizeof(*ipver) > data_end)
		return NULL;

	if ((*ipver >> 4) != 6)
		return NULL;

	ip = cursor_advance(cursor, sizeof(*ip));
	if ((void *)ip + sizeof(*ip) > data_end)
		return NULL;

	if (ip->next_header != 43)
		return NULL;

	srh = cursor_advance(cursor, sizeof(*srh));
	if ((void *)srh + sizeof(*srh) > data_end)
		return NULL;

	if (srh->type != 4)
		return NULL;

	return srh;
}

static __always_inline
int update_tlv_pad(struct __sk_buff *skb, uint32_t new_pad,
		   uint32_t old_pad, uint32_t pad_off)
{
	int err;

	if (new_pad != old_pad) {
		err = bpf_lwt_seg6_adjust_srh(skb, pad_off,
					  (int) new_pad - (int) old_pad);
		if (err)
			return err;
	}

	if (new_pad > 0) {
		char pad_tlv_buf[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
					0, 0, 0};
		struct sr6_tlv_t *pad_tlv = (struct sr6_tlv_t *) pad_tlv_buf;

		pad_tlv->type = SR6_TLV_PADDING;
		pad_tlv->len = new_pad - 2;

Annotation

Implementation Notes