@@ -189,6 +189,7 @@ enum bpf_prog_type {
BPF_PROG_TYPE_STRUCT_OPS,
BPF_PROG_TYPE_EXT,
BPF_PROG_TYPE_LSM,
+ BPF_PROG_TYPE_SK_LOOKUP,
};
enum bpf_attach_type {
@@ -227,6 +228,7 @@ enum bpf_attach_type {
BPF_CGROUP_INET6_GETSOCKNAME,
BPF_XDP_DEVMAP,
BPF_CGROUP_INET_SOCK_RELEASE,
+ BPF_SK_LOOKUP,
__MAX_BPF_ATTACH_TYPE
};
@@ -3068,6 +3070,10 @@ union bpf_attr {
*
* long bpf_sk_assign(struct sk_buff *skb, struct bpf_sock *sk, u64 flags)
* Description
+ * Helper is overloaded depending on BPF program type. This
+ * description applies to **BPF_PROG_TYPE_SCHED_CLS** and
+ * **BPF_PROG_TYPE_SCHED_ACT** programs.
+ *
* Assign the *sk* to the *skb*. When combined with appropriate
* routing configuration to receive the packet towards the socket,
* will cause *skb* to be delivered to the specified socket.
@@ -3093,6 +3099,56 @@ union bpf_attr {
* **-ESOCKTNOSUPPORT** if the socket type is not supported
* (reuseport).
*
+ * long bpf_sk_assign(struct bpf_sk_lookup *ctx, struct bpf_sock *sk, u64 flags)
+ * Description
+ * Helper is overloaded depending on BPF program type. This
+ * description applies to **BPF_PROG_TYPE_SK_LOOKUP** programs.
+ *
+ * Select the *sk* as a result of a socket lookup.
+ *
+ * For the operation to succeed passed socket must be compatible
+ * with the packet description provided by the *ctx* object.
+ *
+ * L4 protocol (**IPPROTO_TCP** or **IPPROTO_UDP**) must
+ * be an exact match. While IP family (**AF_INET** or
+ * **AF_INET6**) must be compatible, that is IPv6 sockets
+ * that are not v6-only can be selected for IPv4 packets.
+ *
+ * Only TCP listeners and UDP unconnected sockets can be
+ * selected. *sk* can also be NULL to reset any previous
+ * selection.
+ *
+ * *flags* argument can combination of following values:
+ *
+ * * **BPF_SK_LOOKUP_F_REPLACE** to override the previous
+ * socket selection, potentially done by a BPF program
+ * that ran before us.
+ *
+ * * **BPF_SK_LOOKUP_F_NO_REUSEPORT** to skip
+ * load-balancing within reuseport group for the socket
+ * being selected.
+ *
+ * On success *ctx->sk* will point to the selected socket.
+ *
+ * Return
+ * 0 on success, or a negative errno in case of failure.
+ *
+ * * **-EAFNOSUPPORT** if socket family (*sk->family*) is
+ * not compatible with packet family (*ctx->family*).
+ *
+ * * **-EEXIST** if socket has been already selected,
+ * potentially by another program, and
+ * **BPF_SK_LOOKUP_F_REPLACE** flag was not specified.
+ *
+ * * **-EINVAL** if unsupported flags were specified.
+ *
+ * * **-EPROTOTYPE** if socket L4 protocol
+ * (*sk->protocol*) doesn't match packet protocol
+ * (*ctx->protocol*).
+ *
+ * * **-ESOCKTNOSUPPORT** if socket is not in allowed
+ * state (TCP listening or UDP unconnected).
+ *
* u64 bpf_ktime_get_boot_ns(void)
* Description
* Return the time elapsed since system boot, in nanoseconds.
@@ -3605,6 +3661,12 @@ enum {
BPF_RINGBUF_HDR_SZ = 8,
};
+/* BPF_FUNC_sk_assign flags in bpf_sk_lookup context. */
+enum {
+ BPF_SK_LOOKUP_F_REPLACE = (1ULL << 0),
+ BPF_SK_LOOKUP_F_NO_REUSEPORT = (1ULL << 1),
+};
+
/* Mode for BPF_FUNC_skb_adjust_room helper. */
enum bpf_adj_room_mode {
BPF_ADJ_ROOM_NET,
@@ -4334,4 +4396,19 @@ struct bpf_pidns_info {
__u32 pid;
__u32 tgid;
};
+
+/* User accessible data for SK_LOOKUP programs. Add new fields at the end. */
+struct bpf_sk_lookup {
+ __bpf_md_ptr(struct bpf_sock *, sk); /* Selected socket */
+
+ __u32 family; /* Protocol family (AF_INET, AF_INET6) */
+ __u32 protocol; /* IP protocol (IPPROTO_TCP, IPPROTO_UDP) */
+ __u32 remote_ip4; /* Network byte order */
+ __u32 remote_ip6[4]; /* Network byte order */
+ __u32 remote_port; /* Network byte order */
+ __u32 local_ip4; /* Network byte order */
+ __u32 local_ip6[4]; /* Network byte order */
+ __u32 local_port; /* Host byte order */
+};
+
#endif /* _UAPI__LINUX_BPF_H__ */
Newly added program, context type and helper is used by tests in a subsequent patch. Synchronize the header file. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> --- Notes: v4: - Update after changes to bpf.h in earlier patch. v3: - Update after changes to bpf.h in earlier patch. v2: - Update after changes to bpf.h in earlier patch. tools/include/uapi/linux/bpf.h | 77 ++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+)