[bpf-next,1/4] bpf: export bpf_sock for BPF_PROG_TYPE_CGROUP_SOCK_ADDR prog type
diff mbox series

Message ID 20190612173040.61944-1-sdf@google.com
State Accepted
Delegated to: BPF Maintainers
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Series
  • [bpf-next,1/4] bpf: export bpf_sock for BPF_PROG_TYPE_CGROUP_SOCK_ADDR prog type
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Commit Message

Stanislav Fomichev June 12, 2019, 5:30 p.m. UTC
And let it use bpf_sk_storage_{get,delete} helpers to access socket
storage. Kernel context (struct bpf_sock_addr_kern) already has sk
member, so I just expose it to the BPF hooks. Using PTR_TO_SOCKET
instead of PTR_TO_SOCK_COMMON should be safe because the hook is
called on bind/connect.

Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
 include/uapi/linux/bpf.h |  1 +
 net/core/filter.c        | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

Comments

Daniel Borkmann June 14, 2019, 11:23 p.m. UTC | #1
On 06/12/2019 07:30 PM, Stanislav Fomichev wrote:
> And let it use bpf_sk_storage_{get,delete} helpers to access socket
> storage. Kernel context (struct bpf_sock_addr_kern) already has sk
> member, so I just expose it to the BPF hooks. Using PTR_TO_SOCKET
> instead of PTR_TO_SOCK_COMMON should be safe because the hook is
> called on bind/connect.
> 
> Cc: Martin Lau <kafai@fb.com>
> Signed-off-by: Stanislav Fomichev <sdf@google.com>

Looks good, applied, thanks!

Patch
diff mbox series

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index ae0907d8c03a..8815fc418cde 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -3247,6 +3247,7 @@  struct bpf_sock_addr {
 	__u32 msg_src_ip6[4];	/* Allows 1,2,4-byte read an 4-byte write.
 				 * Stored in network byte order.
 				 */
+	__bpf_md_ptr(struct bpf_sock *, sk);
 };
 
 /* User bpf_sock_ops struct to access socket values and specify request ops
diff --git a/net/core/filter.c b/net/core/filter.c
index a5e4ac7fcbe5..37c4a2fd559b 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5922,6 +5922,10 @@  sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 	case BPF_FUNC_skc_lookup_tcp:
 		return &bpf_sock_addr_skc_lookup_tcp_proto;
 #endif /* CONFIG_INET */
+	case BPF_FUNC_sk_storage_get:
+		return &bpf_sk_storage_get_proto;
+	case BPF_FUNC_sk_storage_delete:
+		return &bpf_sk_storage_delete_proto;
 	default:
 		return bpf_base_func_proto(func_id);
 	}
@@ -6828,6 +6832,13 @@  static bool sock_addr_is_valid_access(int off, int size,
 		if (size != size_default)
 			return false;
 		break;
+	case offsetof(struct bpf_sock_addr, sk):
+		if (type != BPF_READ)
+			return false;
+		if (size != sizeof(__u64))
+			return false;
+		info->reg_type = PTR_TO_SOCKET;
+		break;
 	default:
 		if (type == BPF_READ) {
 			if (size != size_default)
@@ -7778,6 +7789,11 @@  static u32 sock_addr_convert_ctx_access(enum bpf_access_type type,
 			struct bpf_sock_addr_kern, struct in6_addr, t_ctx,
 			s6_addr32[0], BPF_SIZE(si->code), off, tmp_reg);
 		break;
+	case offsetof(struct bpf_sock_addr, sk):
+		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_sock_addr_kern, sk),
+				      si->dst_reg, si->src_reg,
+				      offsetof(struct bpf_sock_addr_kern, sk));
+		break;
 	}
 
 	return insn - insn_buf;