xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

bpf: helper to pop data from messages

Browse Source 
This adds a BPF SK_MSG program helper so that we can pop data from a
msg. We use this to pop metadata from a previous push data call.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
John Fastabend
2018-11-26 14:16:17 -08:00
committed by Daniel Borkmann
parent 17d95e4225
commit 7246d8ed4d
4 changed files with 209 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
net/ipv4/tcp_bpf.c
View File

@@ -289,12 +289,23 @@ static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
{
bool cork = false, enospc = msg->sg.start == msg->sg.end;
struct sock *sk_redir;
u32 tosend;
u32 tosend, delta = 0;
int ret;
more_data:
if (psock->eval == __SK_NONE)
if (psock->eval == __SK_NONE) {
/* Track delta in msg size to add/subtract it on SK_DROP from
* returned to user copied size. This ensures user doesn't
* get a positive return code with msg_cut_data and SK_DROP
* verdict.
*/
delta = msg->sg.size;
psock->eval = sk_psock_msg_verdict(sk, psock, msg);
if (msg->sg.size < delta)
delta -= msg->sg.size;
else
delta = 0;
}
if (msg->cork_bytes &&
msg->cork_bytes > msg->sg.size && !enospc) {
@@ -350,7 +361,7 @@ more_data:
default:
sk_msg_free_partial(sk, msg, tosend);
sk_msg_apply_bytes(psock, tosend);
*copied -= tosend;
*copied -= (tosend + delta);
return -EACCES;
}