tools/tcpconnect: Support IPv6 DNS

Add IPv6 DNS support for tcpconnect. Fixes iovisor#3933. Signed-off-by: Hengqi Chen <[email protected]>
Limnotation · Apr 27, 2022 · 1e510db · 1e510db
1 parent 7231ddb
commit 1e510db
Showing 1 changed file with 26 additions and 0 deletions.
diff --git a/tools/tcpconnect.py b/tools/tcpconnect.py
@@ -322,6 +322,31 @@
  return 0;
 }
 
+#include <uapi/linux/udp.h>
+
+int trace_udpv6_recvmsg(struct pt_regs *ctx)
+{
+ struct sk_buff *skb = (struct sk_buff *)PT_REGS_PARM2(ctx);
+ struct udphdr *hdr = (void*)skb->head + skb->transport_header;
+ struct dns_data_t *event;
+ int zero = 0;
+ void *data;
+
+ /* hex(53) = 0x0035, htons(0x0035) = 0x3500 */
+ if (hdr->source != 0x3500)
+ return 0;
+
+ /* skip UDP header */
+ data = skb->data + 8;
+
+ event = dns_data.lookup(&zero);
+ if (!event)
+ return 0;
+
+ bpf_probe_read(event->pkt, sizeof(event->pkt), data);
+ dns_events.perf_submit(ctx, event, sizeof(*event));
+ return 0;
+}
 """
 
 if args.count and args.dns:
@@ -510,6 +535,7 @@ def save_dns(cpu, data, size):
 if args.dns:
  b.attach_kprobe(event="udp_recvmsg", fn_name="trace_udp_recvmsg")
  b.attach_kretprobe(event="udp_recvmsg", fn_name="trace_udp_ret_recvmsg")
+ b.attach_kprobe(event="udpv6_queue_rcv_one_skb", fn_name="trace_udpv6_recvmsg")
 
 print("Tracing connect ... Hit Ctrl-C to end")
 if args.count: