handle return value in kretprobe handler for tcpv4connect

Signed-off-by: Yonghong Song <yhs@plumgrid.com>

diff --git a/tools/tcpv4connect b/tools/tcpv4connect
index fdada97..67a2894 100755 (executable)
--- a/tools/tcpv4connect
+++ b/tools/tcpv4connect
@@ -61,6 +61,13 @@ int kretprobe__tcp_v4_connect(struct pt_regs *ctx)
                return 0;       // missed entry
        }
 
+       if (ret != 0) {
+               // failed to send SYNC packet, socket __sk_common.{skc_rcv_saddr, ...}
+               // may not be populated properly.
+               currsock.delete(&pid);
+               return 0;
+       }
+
        // pull in details
        struct sock *skp = *skpp;
        u32 saddr = 0, daddr = 0;