[PATCH net-next] bpf: expose sk_priority through struct bpf_sock_ops

[Vlad Dumitrescu]

From: Vlad Dumitrescu <vla...@google.com>

Allows BPF_PROG_TYPE_SOCK_OPS programs to read sk_priority.

Signed-off-by: Vlad Dumitrescu <vla...@google.com>
---
 include/uapi/linux/bpf.h       |  1 +
 net/core/filter.c              | 11 +++++++++++
 tools/include/uapi/linux/bpf.h |  1 +
 3 files changed, 13 insertions(+)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index e880ae6434ee..9757a2002513 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -947,6 +947,7 @@ struct bpf_sock_ops {
        __u32 local_ip6[4];     /* Stored in network byte order */
        __u32 remote_port;      /* Stored in network byte order */
        __u32 local_port;       /* stored in host byte order */
+       __u32 priority;
 };
 
 /* List of known BPF sock_ops operators.
diff --git a/net/core/filter.c b/net/core/filter.c
index 61c791f9f628..a6329642d047 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4449,6 +4449,17 @@ static u32 sock_ops_convert_ctx_access(enum 
bpf_access_type type,
                *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->dst_reg,
                                      offsetof(struct sock_common, skc_num));
                break;
+
+       case offsetof(struct bpf_sock_ops, priority):
+               BUILD_BUG_ON(FIELD_SIZEOF(struct sock, sk_priority) != 4);
+
+               *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(
+                                               struct bpf_sock_ops_kern, sk),
+                                     si->dst_reg, si->src_reg,
+                                     offsetof(struct bpf_sock_ops_kern, sk));
+               *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,
+                                     offsetof(struct sock, sk_priority));
+               break;
        }
        return insn - insn_buf;
 }
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index e880ae6434ee..9757a2002513 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -947,6 +947,7 @@ struct bpf_sock_ops {
        __u32 local_ip6[4];     /* Stored in network byte order */
        __u32 remote_port;      /* Stored in network byte order */
        __u32 local_port;       /* stored in host byte order */
+       __u32 priority;
 };
 
 /* List of known BPF sock_ops operators.
-- 
2.15.0.448.gf294e3d99a-goog