Commit e28784e3 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

bpf: Factor out attach_type to prog_type mapping for attach/detach 



Factor out logic mapping expected program attach type to program type and
subsequent handling of program attach/detach. Also list out all supported
cgroup BPF program types explicitly to prevent accidental bugs once more
program types are added to a mapping. Do the same for prog_query API.

Signed-off-by: default avatarAndrii Nakryiko <andriin@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200325065746.640559-3-andriin@fb.com
parent 00c4eddf

kernel/bpf/syscall.c

+66 −87
Original line number Diff line number Diff line
@@ -2535,36 +2535,18 @@ static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog, 
	}

}



#define BPF_PROG_ATTACH_LAST_FIELD replace_bpf_fd



#define BPF_F_ATTACH_MASK \

	(BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI | BPF_F_REPLACE)



static int bpf_prog_attach(const union bpf_attr *attr)

static enum bpf_prog_type

attach_type_to_prog_type(enum bpf_attach_type attach_type)

{

	enum bpf_prog_type ptype;

	struct bpf_prog *prog;

	int ret;



	if (!capable(CAP_NET_ADMIN))

		return -EPERM;



	if (CHECK_ATTR(BPF_PROG_ATTACH))

		return -EINVAL;



	if (attr->attach_flags & ~BPF_F_ATTACH_MASK)

		return -EINVAL;



	switch (attr->attach_type) {

	switch (attach_type) {

	case BPF_CGROUP_INET_INGRESS:

	case BPF_CGROUP_INET_EGRESS:

		ptype = BPF_PROG_TYPE_CGROUP_SKB;

		return BPF_PROG_TYPE_CGROUP_SKB;

		break;

	case BPF_CGROUP_INET_SOCK_CREATE:

	case BPF_CGROUP_INET4_POST_BIND:

	case BPF_CGROUP_INET6_POST_BIND:

		ptype = BPF_PROG_TYPE_CGROUP_SOCK;

		break;

		return BPF_PROG_TYPE_CGROUP_SOCK;

	case BPF_CGROUP_INET4_BIND:

	case BPF_CGROUP_INET6_BIND:

	case BPF_CGROUP_INET4_CONNECT:
@@ -2573,38 +2555,54 @@ static int bpf_prog_attach(const union bpf_attr *attr) 
	case BPF_CGROUP_UDP6_SENDMSG:

	case BPF_CGROUP_UDP4_RECVMSG:

	case BPF_CGROUP_UDP6_RECVMSG:

		ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;

		break;

		return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;

	case BPF_CGROUP_SOCK_OPS:

		ptype = BPF_PROG_TYPE_SOCK_OPS;

		break;

		return BPF_PROG_TYPE_SOCK_OPS;

	case BPF_CGROUP_DEVICE:

		ptype = BPF_PROG_TYPE_CGROUP_DEVICE;

		break;

		return BPF_PROG_TYPE_CGROUP_DEVICE;

	case BPF_SK_MSG_VERDICT:

		ptype = BPF_PROG_TYPE_SK_MSG;

		break;

		return BPF_PROG_TYPE_SK_MSG;

	case BPF_SK_SKB_STREAM_PARSER:

	case BPF_SK_SKB_STREAM_VERDICT:

		ptype = BPF_PROG_TYPE_SK_SKB;

		break;

		return BPF_PROG_TYPE_SK_SKB;

	case BPF_LIRC_MODE2:

		ptype = BPF_PROG_TYPE_LIRC_MODE2;

		break;

		return BPF_PROG_TYPE_LIRC_MODE2;

	case BPF_FLOW_DISSECTOR:

		ptype = BPF_PROG_TYPE_FLOW_DISSECTOR;

		break;

		return BPF_PROG_TYPE_FLOW_DISSECTOR;

	case BPF_CGROUP_SYSCTL:

		ptype = BPF_PROG_TYPE_CGROUP_SYSCTL;

		break;

		return BPF_PROG_TYPE_CGROUP_SYSCTL;

	case BPF_CGROUP_GETSOCKOPT:

	case BPF_CGROUP_SETSOCKOPT:

		ptype = BPF_PROG_TYPE_CGROUP_SOCKOPT;

		break;

		return BPF_PROG_TYPE_CGROUP_SOCKOPT;

	default:

		return -EINVAL;

		return BPF_PROG_TYPE_UNSPEC;

	}

}



#define BPF_PROG_ATTACH_LAST_FIELD replace_bpf_fd



#define BPF_F_ATTACH_MASK \

	(BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI | BPF_F_REPLACE)



static int bpf_prog_attach(const union bpf_attr *attr)

{

	enum bpf_prog_type ptype;

	struct bpf_prog *prog;

	int ret;



	if (!capable(CAP_NET_ADMIN))

		return -EPERM;



	if (CHECK_ATTR(BPF_PROG_ATTACH))

		return -EINVAL;



	if (attr->attach_flags & ~BPF_F_ATTACH_MASK)

		return -EINVAL;



	ptype = attach_type_to_prog_type(attr->attach_type);

	if (ptype == BPF_PROG_TYPE_UNSPEC)

		return -EINVAL;



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

	if (IS_ERR(prog))

		return PTR_ERR(prog);
@@ -2625,8 +2623,17 @@ static int bpf_prog_attach(const union bpf_attr *attr) 
	case BPF_PROG_TYPE_FLOW_DISSECTOR:

		ret = skb_flow_dissector_bpf_prog_attach(attr, prog);

		break;

	default:

	case BPF_PROG_TYPE_CGROUP_DEVICE:

	case BPF_PROG_TYPE_CGROUP_SKB:

	case BPF_PROG_TYPE_CGROUP_SOCK:

	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:

	case BPF_PROG_TYPE_CGROUP_SOCKOPT:

	case BPF_PROG_TYPE_CGROUP_SYSCTL:

	case BPF_PROG_TYPE_SOCK_OPS:

		ret = cgroup_bpf_prog_attach(attr, ptype, prog);

		break;

	default:

		ret = -EINVAL;

	}



	if (ret)
@@ -2646,53 +2653,27 @@ static int bpf_prog_detach(const union bpf_attr *attr) 
	if (CHECK_ATTR(BPF_PROG_DETACH))

		return -EINVAL;



	switch (attr->attach_type) {

	case BPF_CGROUP_INET_INGRESS:

	case BPF_CGROUP_INET_EGRESS:

		ptype = BPF_PROG_TYPE_CGROUP_SKB;

		break;

	case BPF_CGROUP_INET_SOCK_CREATE:

	case BPF_CGROUP_INET4_POST_BIND:

	case BPF_CGROUP_INET6_POST_BIND:

		ptype = BPF_PROG_TYPE_CGROUP_SOCK;

		break;

	case BPF_CGROUP_INET4_BIND:

	case BPF_CGROUP_INET6_BIND:

	case BPF_CGROUP_INET4_CONNECT:

	case BPF_CGROUP_INET6_CONNECT:

	case BPF_CGROUP_UDP4_SENDMSG:

	case BPF_CGROUP_UDP6_SENDMSG:

	case BPF_CGROUP_UDP4_RECVMSG:

	case BPF_CGROUP_UDP6_RECVMSG:

		ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;

		break;

	case BPF_CGROUP_SOCK_OPS:

		ptype = BPF_PROG_TYPE_SOCK_OPS;

		break;

	case BPF_CGROUP_DEVICE:

		ptype = BPF_PROG_TYPE_CGROUP_DEVICE;

		break;

	case BPF_SK_MSG_VERDICT:

		return sock_map_get_from_fd(attr, NULL);

	case BPF_SK_SKB_STREAM_PARSER:

	case BPF_SK_SKB_STREAM_VERDICT:

	ptype = attach_type_to_prog_type(attr->attach_type);



	switch (ptype) {

	case BPF_PROG_TYPE_SK_MSG:

	case BPF_PROG_TYPE_SK_SKB:

		return sock_map_get_from_fd(attr, NULL);

	case BPF_LIRC_MODE2:

	case BPF_PROG_TYPE_LIRC_MODE2:

		return lirc_prog_detach(attr);

	case BPF_FLOW_DISSECTOR:

	case BPF_PROG_TYPE_FLOW_DISSECTOR:

		return skb_flow_dissector_bpf_prog_detach(attr);

	case BPF_CGROUP_SYSCTL:

		ptype = BPF_PROG_TYPE_CGROUP_SYSCTL;

		break;

	case BPF_CGROUP_GETSOCKOPT:

	case BPF_CGROUP_SETSOCKOPT:

		ptype = BPF_PROG_TYPE_CGROUP_SOCKOPT;

		break;

	case BPF_PROG_TYPE_CGROUP_DEVICE:

	case BPF_PROG_TYPE_CGROUP_SKB:

	case BPF_PROG_TYPE_CGROUP_SOCK:

	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:

	case BPF_PROG_TYPE_CGROUP_SOCKOPT:

	case BPF_PROG_TYPE_CGROUP_SYSCTL:

	case BPF_PROG_TYPE_SOCK_OPS:

		return cgroup_bpf_prog_detach(attr, ptype);

	default:

		return -EINVAL;

	}



	return cgroup_bpf_prog_detach(attr, ptype);

}



#define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
@@ -2726,7 +2707,7 @@ static int bpf_prog_query(const union bpf_attr *attr, 
	case BPF_CGROUP_SYSCTL:

	case BPF_CGROUP_GETSOCKOPT:

	case BPF_CGROUP_SETSOCKOPT:

		break;

		return cgroup_bpf_prog_query(attr, uattr);

	case BPF_LIRC_MODE2:

		return lirc_prog_query(attr, uattr);

	case BPF_FLOW_DISSECTOR:
@@ -2734,8 +2715,6 @@ static int bpf_prog_query(const union bpf_attr *attr, 
	default:

		return -EINVAL;

	}



	return cgroup_bpf_prog_query(attr, uattr);

}



#define BPF_PROG_TEST_RUN_LAST_FIELD test.ctx_out

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