diff options
| author |   Petar Penkov <ppenkov@google.com> | 2019-07-29 09:59:16 -0700 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2019-07-30 21:03:05 -0700 |
| commit | 3745ee18017e36be34f6f2a81e802a20e54e5e8b (patch) | |
| tree | e40f25cce18dd51d6949066412129d0bedfa3943 /tools/include/uapi/linux/bpf.h | |
| parent | bpf: add bpf_tcp_gen_syncookie helper (diff) | |
| download | linux-dev-3745ee18017e36be34f6f2a81e802a20e54e5e8b.tar.xz linux-dev-3745ee18017e36be34f6f2a81e802a20e54e5e8b.zip | |
bpf: sync bpf.h to tools/
Sync updated documentation for bpf_redirect_map.
Sync the bpf_tcp_gen_syncookie helper function definition with the one
in tools/uapi.
Signed-off-by: Petar Penkov <ppenkov@google.com>
Reviewed-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to '')
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 37 |
1 files changed, 34 insertions, 3 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 21d0f6863df3..4393bd4b2419 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1572,8 +1572,11 @@ union bpf_attr { * but this is only implemented for native XDP (with driver * support) as of this writing). * - * All values for *flags* are reserved for future usage, and must - * be left at zero. + * The lower two bits of *flags* are used as the return code if + * the map lookup fails. This is so that the return value can be + * one of the XDP program return codes up to XDP_TX, as chosen by + * the caller. Any higher bits in the *flags* argument must be + * unset. * * When used to redirect packets to net devices, this helper * provides a high performance increase over **bpf_redirect**\ (). @@ -2711,6 +2714,33 @@ union bpf_attr { * **-EPERM** if no permission to send the *sig*. * * **-EAGAIN** if bpf program can try again. + * + * s64 bpf_tcp_gen_syncookie(struct bpf_sock *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len) + * Description + * Try to issue a SYN cookie for the packet with corresponding + * IP/TCP headers, *iph* and *th*, on the listening socket in *sk*. + * + * *iph* points to the start of the IPv4 or IPv6 header, while + * *iph_len* contains **sizeof**\ (**struct iphdr**) or + * **sizeof**\ (**struct ip6hdr**). + * + * *th* points to the start of the TCP header, while *th_len* + * contains the length of the TCP header. + * + * Return + * On success, lower 32 bits hold the generated SYN cookie in + * followed by 16 bits which hold the MSS value for that cookie, + * and the top 16 bits are unused. + * + * On failure, the returned value is one of the following: + * + * **-EINVAL** SYN cookie cannot be issued due to error + * + * **-ENOENT** SYN cookie should not be issued (no SYN flood) + * + * **-EOPNOTSUPP** kernel configuration does not enable SYN cookies + * + * **-EPROTONOSUPPORT** IP packet version is not 4 or 6 */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -2822,7 +2852,8 @@ union bpf_attr { FN(strtoul), \ FN(sk_storage_get), \ FN(sk_storage_delete), \ - FN(send_signal), + FN(send_signal), \ + FN(tcp_gen_syncookie), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call |