From d691f9e8d4405c334aa10d556e73c8bf44cb0e01 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 4 Jun 2015 10:11:54 -0700 Subject: bpf: allow programs to write to certain skb fields allow programs read/write skb->mark, tc_index fields and ((struct qdisc_skb_cb *)cb)->data. mark and tc_index are generically useful in TC. cb[0]-cb[4] are primarily used to pass arguments from one program to another called via bpf_tail_call() which can be seen in sockex3_kern.c example. All fields of 'struct __sk_buff' are readable to socket and tc_cls_act progs. mark, tc_index are writeable from tc_cls_act only. cb[0]-cb[4] are writeable by both sockets and tc_cls_act. Add verifier tests and improve sample code. Signed-off-by: Alexei Starovoitov Signed-off-by: David S. Miller --- include/uapi/linux/bpf.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/uapi/linux/bpf.h') diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 42aa19abab86..602f05b7a275 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -248,6 +248,8 @@ struct __sk_buff { __u32 priority; __u32 ingress_ifindex; __u32 ifindex; + __u32 tc_index; + __u32 cb[5]; }; #endif /* _UAPI__LINUX_BPF_H__ */ -- cgit v1.2.3