commit 6ff0511439d145fcf41d784e1fe974797ea7e754
author Hengqi Chen <chenhengqi@outlook.com> Sat Feb 19 17:42:23 2022 +0800
committer yonghong-song <ys114321@gmail.com> Sat Feb 19 10:19:06 2022 -0800
tree ff9d930f947f0cd5ffd3d42a972ae5c653603ed8
parent a9fc750f95de89bba70d9637e787c966897d7523

tools: Fix tcpconnect with kernel 5.14

Kernel commit 8cd54c1c8480 (0) changes iov_iter->type to iov_iter->iter_type,
which breaks tcpconnect. This commit fixes it by detecting kernel struct field
existence.

Closes #3859.

  [0]: https://github.com/torvalds/linux/commit/8cd54c1c848031a87820e58d772166ffdf8c08c0

Signed-off-by: Hengqi Chen <chenhengqi@outlook.com>

tools/tcpconnect.py

diff --git a/tools/tcpconnect.py b/tools/tcpconnect.py
index 8b49c70..a95b4cc 100755
--- a/tools/tcpconnect.py
+++ b/tools/tcpconnect.py
@@ -178,7 +178,7 @@
     u16 dport = skp->__sk_common.skc_dport;
 
     FILTER_PORT
-    
+
     FILTER_FAMILY
 
     if (ipver == 4) {
@@ -295,7 +295,7 @@
         return 0;
 
     struct msghdr *msghdr = (struct msghdr *)*msgpp;
-    if (msghdr->msg_iter.type != ITER_IOVEC)
+    if (msghdr->msg_iter.TYPE_FIELD != ITER_IOVEC)
         goto delete_and_return;
 
     int copied = (int)PT_REGS_RC(ctx);
@@ -361,6 +361,10 @@
 bpf_text = bpf_text.replace('FILTER_UID', '')
 
 if args.dns:
+    if BPF.kernel_struct_has_field(b'iov_iter', b'iter_type') == 1:
+        dns_bpf_text = dns_bpf_text.replace('TYPE_FIELD', 'iter_type')
+    else:
+        dns_bpf_text = dns_bpf_text.replace('TYPE_FIELD', 'type')
     bpf_text += dns_bpf_text
 
 if debug or args.ebpf: