tools/tcpaccept: Fix support for v5.6+ kernels
Commit bf9765145b85 ("sock: Make sk_protocol a 16-bit value") which
landed in kernel 5.6 reorganized a bit the layout of struct sock. Now
sk_protocol is its own field which directly precedes sk_gso_max_segs and
it in turn directly precedes sk_lingertime. This naturally broke
tcpaccept on kernels starting with 5.6.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
diff --git a/tools/tcpaccept.py b/tools/tcpaccept.py
index d3e4414..b2ace4f 100755
--- a/tools/tcpaccept.py
+++ b/tools/tcpaccept.py
@@ -116,7 +116,7 @@
return 0;
// check this is TCP
- u8 protocol = 0;
+ u16 protocol = 0;
// workaround for reading the sk_protocol bitfield:
// Following comments add by Joe Yin:
@@ -132,7 +132,12 @@
int gso_max_segs_offset = offsetof(struct sock, sk_gso_max_segs);
int sk_lingertime_offset = offsetof(struct sock, sk_lingertime);
- if (sk_lingertime_offset - gso_max_segs_offset == 4)
+
+ // Since kernel v5.6 sk_protocol is its own u16 field and gso_max_segs
+ // precedes sk_lingertime.
+ if (sk_lingertime_offset - gso_max_segs_offset == 2)
+ protocol = newsk->sk_protocol;
+ else if (sk_lingertime_offset - gso_max_segs_offset == 4)
// 4.10+ with little endian
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
protocol = *(u8 *)((u64)&newsk->sk_gso_max_segs - 3);