samples/bpf/test_map_in_map.bpf.c

Source file repositories/reference/linux-study-clean/samples/bpf/test_map_in_map.bpf.c

File Facts

System
Linux kernel
Corpus path
samples/bpf/test_map_in_map.bpf.c
Extension
.c
Size
3884 bytes
Lines
173
Domain
Support Tooling And Documentation
Bucket
samples
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 inner_a {
	__uint(type, BPF_MAP_TYPE_ARRAY);
	__type(key, u32);
	__type(value, int);
	__uint(max_entries, MAX_NR_PORTS);
} port_a SEC(".maps");

/* map #1 */
struct inner_h {
	__uint(type, BPF_MAP_TYPE_HASH);
	__type(key, u32);
	__type(value, int);
	__uint(max_entries, 1);
} port_h SEC(".maps");

/* map #2 */
struct {
	__uint(type, BPF_MAP_TYPE_HASH);
	__type(key, u32);
	__type(value, int);
	__uint(max_entries, 1);
} reg_result_h SEC(".maps");

/* map #3 */
struct {
	__uint(type, BPF_MAP_TYPE_HASH);
	__type(key, u32);
	__type(value, int);
	__uint(max_entries, 1);
} inline_result_h SEC(".maps");

/* map #4 */ /* Test case #0 */
struct {
	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
	__uint(max_entries, MAX_NR_PORTS);
	__uint(key_size, sizeof(u32));
	__array(values, struct inner_a); /* use inner_a as inner map */
} a_of_port_a SEC(".maps");

/* map #5 */ /* Test case #1 */
struct {
	__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
	__uint(max_entries, 1);
	__uint(key_size, sizeof(u32));
	__array(values, struct inner_a); /* use inner_a as inner map */
} h_of_port_a SEC(".maps");

/* map #6 */ /* Test case #2 */
struct {
	__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
	__uint(max_entries, 1);
	__uint(key_size, sizeof(u32));
	__array(values, struct inner_h); /* use inner_h as inner map */
} h_of_port_h SEC(".maps");

static __always_inline int do_reg_lookup(void *inner_map, u32 port)
{
	int *result;

	result = bpf_map_lookup_elem(inner_map, &port);
	return result ? *result : -ENOENT;
}

static __always_inline int do_inline_array_lookup(void *inner_map, u32 port)
{
	int *result;

	if (inner_map != &port_a)
		return -EINVAL;

	result = bpf_map_lookup_elem(&port_a, &port);
	return result ? *result : -ENOENT;
}

static __always_inline int do_inline_hash_lookup(void *inner_map, u32 port)
{
	int *result;

	if (inner_map != &port_h)
		return -EINVAL;

	result = bpf_map_lookup_elem(&port_h, &port);
	return result ? *result : -ENOENT;
}

SEC("ksyscall/connect")
int BPF_KSYSCALL(trace_sys_connect, unsigned int fd, struct sockaddr_in6 *in6, int addrlen)
{
	u16 test_case, port, dst6[8];
	int ret, inline_ret, ret_key = 0;

Annotation

Implementation Notes