Unverified Commit 22bae0fc authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!798 bpf: support BPF_PROG_QUERY for progs attached to sockmap 

Merge Pull Request from: @kwb0523 
 
Right now there is no way to query whether BPF programs are
attached to a sockmap or not.

we can use the standard interface in libbpf to query, such as:
bpf_prog_query(mapFd, BPF_SK_SKB_STREAM_PARSER, 0, NULL, ...);
the mapFd is the fd of sockmap. 
 
Link:https://gitee.com/openeuler/kernel/pulls/798

 

Reviewed-by: default avatarYue Haibing <yuehaibing@huawei.com>
Reviewed-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parents 0c374437 05038388

include/linux/bpf.h

+7 −0
Original line number Diff line number Diff line
@@ -1880,6 +1880,7 @@ int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog); 
int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype);

int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value, u64 flags);

void sock_map_unhash(struct sock *sk);

int sock_map_bpf_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr);

void sock_map_close(struct sock *sk, long timeout);

#else

static inline int sock_map_prog_update(struct bpf_map *map,
@@ -1906,6 +1907,12 @@ static inline int sock_map_update_elem_sys(struct bpf_map *map, void *key, void 
{

	return -EOPNOTSUPP;

}



static inline int sock_map_bpf_prog_query(const union bpf_attr *attr,

					   union bpf_attr __user *uattr)

{

	return -EINVAL;

}

#endif /* CONFIG_BPF_STREAM_PARSER */



#if defined(CONFIG_INET) && defined(CONFIG_BPF_SYSCALL)

kernel/bpf/syscall.c

+4 −0
Original line number Diff line number Diff line
@@ -3136,6 +3136,10 @@ static int bpf_prog_query(const union bpf_attr *attr, 
	case BPF_FLOW_DISSECTOR:

	case BPF_SK_LOOKUP:

		return netns_bpf_prog_query(attr, uattr);

	case BPF_SK_SKB_STREAM_PARSER:

	case BPF_SK_SKB_STREAM_VERDICT:

	case BPF_SK_MSG_VERDICT:

		return sock_map_bpf_prog_query(attr, uattr);

	default:

		return -EINVAL;

	}

net/core/sock_map.c

+68 −6
Original line number Diff line number Diff line
@@ -1498,28 +1498,39 @@ static struct sk_psock_progs *sock_map_progs(struct bpf_map *map) 
	return NULL;

}



int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,

			 struct bpf_prog *old, u32 which)

int sock_map_prog_lookup(struct bpf_map *map, struct bpf_prog ***pprog,

			 u32 which)

{

	struct sk_psock_progs *progs = sock_map_progs(map);

	struct bpf_prog **pprog;



	if (!progs)

		return -EOPNOTSUPP;



	switch (which) {

	case BPF_SK_MSG_VERDICT:

		pprog = &progs->msg_parser;

		*pprog = &progs->msg_parser;

		break;

	case BPF_SK_SKB_STREAM_PARSER:

		pprog = &progs->skb_parser;

		*pprog = &progs->skb_parser;

		break;

	case BPF_SK_SKB_STREAM_VERDICT:

		pprog = &progs->skb_verdict;

		*pprog = &progs->skb_verdict;

		break;

	default:

		return -EOPNOTSUPP;

	}

	return 0;

}



int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,

			 struct bpf_prog *old, u32 which)

{

	struct bpf_prog **pprog;

	int ret;



	ret = sock_map_prog_lookup(map, &pprog, which);

	if (ret)

		return ret;



	if (old)

		return psock_replace_prog(pprog, prog, old);
@@ -1528,6 +1539,57 @@ int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, 
	return 0;

}



int sock_map_bpf_prog_query(const union bpf_attr *attr,

			    union bpf_attr __user *uattr)

{

	__u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);

	u32 prog_cnt = 0, flags = 0, ufd = attr->target_fd;

	struct bpf_prog **pprog;

	struct bpf_prog *prog;

	struct bpf_map *map;

	struct fd f;

	u32 id = 0;

	int ret;



	if (attr->query.query_flags)

		return -EINVAL;



	f = fdget(ufd);

	map = __bpf_map_get(f);

	if (IS_ERR(map))

		return PTR_ERR(map);



	rcu_read_lock();



	ret = sock_map_prog_lookup(map, &pprog, attr->query.attach_type);

	if (ret)

		goto end;



	prog = *pprog;

	prog_cnt = !prog ? 0 : 1;



	if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)

		goto end;



	/* we do not hold the refcnt, the bpf prog may be released

	 * asynchronously and the id would be set to 0.

	 */

	id = data_race(prog->aux->id);

	if (id == 0)

		prog_cnt = 0;



end:

	rcu_read_unlock();



	if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)) ||

	    (id != 0 && copy_to_user(prog_ids, &id, sizeof(u32))) ||

	    copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))

		ret = -EFAULT;



	fdput(f);

	return ret;

}



static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link)

{

	switch (link->map->map_type) {