[PATCH bpf-next v5 1/2] Add skb_store_bytes() for BPF_PROG_TYPE_CGROUP_SKB

[Tyler Wear <quic_twear@quicinc.com>]

Need to modify the ds field to support upcoming Wifi QoS Alliance spec.
Instead of adding generic function for just modifying the ds field,
add skb_store_bytes for BPF_PROG_TYPE_CGROUP_SKB.
This allows other fields in the network and transport header to be
modified in the future.

Checksum API's also need to be added for completeness.

It is not possible to use CGROUP_(SET|GET)SOCKOPT since
the policy may change during runtime and would result
in a large number of entries with wildcards.

V4 patch fixes warnings and errors from checkpatch.

The existing check for bpf_try_make_writable() should mean that
skb_share_check() is not needed.

Signed-off-by: Tyler Wear <quic_twear@quicinc.com>
---
 net/core/filter.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/net/core/filter.c b/net/core/filter.c
index 6102f093d59a..ce01a8036361 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -7299,6 +7299,16 @@ cg_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_sk_storage_delete_proto;
 	case BPF_FUNC_perf_event_output:
 		return &bpf_skb_event_output_proto;
+	case BPF_FUNC_skb_store_bytes:
+		return &bpf_skb_store_bytes_proto;
+	case BPF_FUNC_csum_update:
+		return &bpf_csum_update_proto;
+	case BPF_FUNC_csum_level:
+		return &bpf_csum_level_proto;
+	case BPF_FUNC_l3_csum_replace:
+		return &bpf_l3_csum_replace_proto;
+	case BPF_FUNC_l4_csum_replace:
+		return &bpf_l4_csum_replace_proto;
 #ifdef CONFIG_SOCK_CGROUP_DATA
 	case BPF_FUNC_skb_cgroup_id:
 		return &bpf_skb_cgroup_id_proto;
-- 
2.25.1