Commit 464bc0fd authored by John Fastabend's avatar John Fastabend Committed by David S. Miller
Browse files

bpf: convert sockmap field attach_bpf_fd2 to type 



In the initial sockmap API we provided strparser and verdict programs
using a single attach command by extending the attach API with a the
attach_bpf_fd2 field.

However, if we add other programs in the future we will be adding a
field for every new possible type, attach_bpf_fd(3,4,..). This
seems a bit clumsy for an API. So lets push the programs using two
new type fields.

   BPF_SK_SKB_STREAM_PARSER
   BPF_SK_SKB_STREAM_VERDICT

This has the advantage of having a readable name and can easily be
extended in the future.

Updates to samples and sockmap included here also generalize tests
slightly to support upcoming patch for multiple map support.

Signed-off-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Fixes: 174a79ff ("bpf: sockmap with sk redirect support")
Suggested-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 901c5d2f

include/linux/bpf.h

+8 −2
Original line number Diff line number Diff line
@@ -39,8 +39,6 @@ struct bpf_map_ops { 
	void (*map_fd_put_ptr)(void *ptr);

	u32 (*map_gen_lookup)(struct bpf_map *map, struct bpf_insn *insn_buf);

	u32 (*map_fd_sys_lookup_elem)(void *ptr);

	int (*map_attach)(struct bpf_map *map,

			  struct bpf_prog *p1, struct bpf_prog *p2);

};



struct bpf_map {
@@ -387,11 +385,19 @@ static inline void __dev_map_flush(struct bpf_map *map) 


#if defined(CONFIG_STREAM_PARSER) && defined(CONFIG_BPF_SYSCALL)

struct sock  *__sock_map_lookup_elem(struct bpf_map *map, u32 key);

int sock_map_attach_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type);

#else

static inline struct sock  *__sock_map_lookup_elem(struct bpf_map *map, u32 key)

{

	return NULL;

}



static inline int sock_map_attach_prog(struct bpf_map *map,

				       struct bpf_prog *prog,

				       u32 type)

{

	return -EOPNOTSUPP;

}

#endif



/* verifier prototypes for helper functions called from eBPF programs */

include/uapi/linux/bpf.h

+3 −6
Original line number Diff line number Diff line
@@ -136,7 +136,8 @@ enum bpf_attach_type { 
	BPF_CGROUP_INET_EGRESS,

	BPF_CGROUP_INET_SOCK_CREATE,

	BPF_CGROUP_SOCK_OPS,

	BPF_CGROUP_SMAP_INGRESS,

	BPF_SK_SKB_STREAM_PARSER,

	BPF_SK_SKB_STREAM_VERDICT,

	__MAX_BPF_ATTACH_TYPE

};
@@ -224,7 +225,6 @@ union bpf_attr { 
		__u32		attach_bpf_fd;	/* eBPF program to attach */

		__u32		attach_type;

		__u32		attach_flags;

		__u32		attach_bpf_fd2;

	};



	struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
@@ -580,14 +580,11 @@ union bpf_attr { 
 *     @flags: reserved for future use

 *     Return: SK_REDIRECT

 *

 * int bpf_sock_map_update(skops, map, key, flags, map_flags)

 * int bpf_sock_map_update(skops, map, key, flags)

 *	@skops: pointer to bpf_sock_ops

 *	@map: pointer to sockmap to update

 *	@key: key to insert/update sock in map

 *	@flags: same flags as map update elem

 *	@map_flags: sock map specific flags

 *	   bit 1: Enable strparser

 *	   other bits: reserved

 */

#define __BPF_FUNC_MAPPER(FN)		\

	FN(unspec),			\

kernel/bpf/sockmap.c

+14 −11
Original line number Diff line number Diff line
@@ -723,20 +723,24 @@ out: 
	return err;

}



static int sock_map_attach_prog(struct bpf_map *map,

				struct bpf_prog *parse,

				struct bpf_prog *verdict)

int sock_map_attach_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type)

{

	struct bpf_stab *stab = container_of(map, struct bpf_stab, map);

	struct bpf_prog *_parse, *_verdict;

	struct bpf_prog *orig;



	_parse = xchg(&stab->bpf_parse, parse);

	_verdict = xchg(&stab->bpf_verdict, verdict);

	switch (type) {

	case BPF_SK_SKB_STREAM_PARSER:

		orig = xchg(&stab->bpf_parse, prog);

		break;

	case BPF_SK_SKB_STREAM_VERDICT:

		orig = xchg(&stab->bpf_verdict, prog);

		break;

	default:

		return -EOPNOTSUPP;

	}



	if (_parse)

		bpf_prog_put(_parse);

	if (_verdict)

		bpf_prog_put(_verdict);

	if (orig)

		bpf_prog_put(orig);



	return 0;

}
@@ -777,7 +781,6 @@ const struct bpf_map_ops sock_map_ops = { 
	.map_get_next_key = sock_map_get_next_key,

	.map_update_elem = sock_map_update_elem,

	.map_delete_elem = sock_map_delete_elem,

	.map_attach = sock_map_attach_prog,

};



BPF_CALL_5(bpf_sock_map_update, struct bpf_sock_ops_kern *, bpf_sock,

kernel/bpf/syscall.c

+11 −27
Original line number Diff line number Diff line
@@ -1093,12 +1093,12 @@ static int bpf_obj_get(const union bpf_attr *attr) 


#ifdef CONFIG_CGROUP_BPF



#define BPF_PROG_ATTACH_LAST_FIELD attach_bpf_fd2

#define BPF_PROG_ATTACH_LAST_FIELD attach_flags



static int sockmap_get_from_fd(const union bpf_attr *attr, int ptype)

static int sockmap_get_from_fd(const union bpf_attr *attr)

{

	struct bpf_prog *prog1, *prog2;

	int ufd = attr->target_fd;

	struct bpf_prog *prog;

	struct bpf_map *map;

	struct fd f;

	int err;
@@ -1108,29 +1108,16 @@ static int sockmap_get_from_fd(const union bpf_attr *attr, int ptype) 
	if (IS_ERR(map))

		return PTR_ERR(map);



	if (!map->ops->map_attach) {

		fdput(f);

		return -EOPNOTSUPP;

	}



	prog1 = bpf_prog_get_type(attr->attach_bpf_fd, ptype);

	if (IS_ERR(prog1)) {

	prog = bpf_prog_get_type(attr->attach_bpf_fd, BPF_PROG_TYPE_SK_SKB);

	if (IS_ERR(prog)) {

		fdput(f);

		return PTR_ERR(prog1);

	}



	prog2 = bpf_prog_get_type(attr->attach_bpf_fd2, ptype);

	if (IS_ERR(prog2)) {

		fdput(f);

		bpf_prog_put(prog1);

		return PTR_ERR(prog2);

		return PTR_ERR(prog);

	}



	err = map->ops->map_attach(map, prog1, prog2);

	err = sock_map_attach_prog(map, prog, attr->attach_type);

	if (err) {

		fdput(f);

		bpf_prog_put(prog1);

		bpf_prog_put(prog2);

		bpf_prog_put(prog);

		return err;

	}
@@ -1165,16 +1152,13 @@ static int bpf_prog_attach(const union bpf_attr *attr) 
	case BPF_CGROUP_SOCK_OPS:

		ptype = BPF_PROG_TYPE_SOCK_OPS;

		break;

	case BPF_CGROUP_SMAP_INGRESS:

		ptype = BPF_PROG_TYPE_SK_SKB;

		break;

	case BPF_SK_SKB_STREAM_PARSER:

	case BPF_SK_SKB_STREAM_VERDICT:

		return sockmap_get_from_fd(attr);

	default:

		return -EINVAL;

	}



	if (attr->attach_type == BPF_CGROUP_SMAP_INGRESS)

		return sockmap_get_from_fd(attr, ptype);



	prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);

	if (IS_ERR(prog))

		return PTR_ERR(prog);

samples/sockmap/sockmap_kern.c

+2 −4
Original line number Diff line number Diff line
@@ -82,8 +82,7 @@ int bpf_sockmap(struct bpf_sock_ops *skops) 
		if (lport == 10000) {

			ret = 1;

			err = bpf_sock_map_update(skops, &sock_map, &ret,

						  BPF_NOEXIST,

						  BPF_SOCKMAP_STRPARSER);

						  BPF_NOEXIST);

			bpf_printk("passive(%i -> %i) map ctx update err: %d\n",

				   lport, bpf_ntohl(rport), err);

		}
@@ -95,8 +94,7 @@ int bpf_sockmap(struct bpf_sock_ops *skops) 
		if (bpf_ntohl(rport) == 10001) {

			ret = 10;

			err = bpf_sock_map_update(skops, &sock_map, &ret,

						  BPF_NOEXIST,

						  BPF_SOCKMAP_STRPARSER);

						  BPF_NOEXIST);

			bpf_printk("active(%i -> %i) map ctx update err: %d\n",

				   lport, bpf_ntohl(rport), err);

		}

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