Hoist the send/recv logic in test.py into a helper function,
snd_rcv_packets().  This is a preparatory refactoring for the
rds over ROCE series which can use the same function to run
the test over tcp, rdma, or both.  No functional changes are
introduced in this patch.

Signed-off-by: Allison Henderson <achender@kernel.org>
---
 tools/testing/selftests/net/rds/test.py | 99 ++++++++++++++-----------
 1 file changed, 54 insertions(+), 45 deletions(-)

diff --git a/tools/testing/selftests/net/rds/test.py b/tools/testing/selftests/net/rds/test.py
index 6a7a5fe20034..38f6100a6e33 100755
--- a/tools/testing/selftests/net/rds/test.py
+++ b/tools/testing/selftests/net/rds/test.py
@@ -167,6 +167,59 @@ def verify_hashes(snd_hashes, rcv_hashes):
         ksft_pr(f"{key[0]}/{key[1]}: ok")
     return 0
 
+def snd_rcv_packets(addrs, netns_list):
+    """
+    Send packets on the given network interfaces
+
+    :param addrs: list of (ip, port) tuples matching the sockets
+    :param netns_list: list of network namespaces
+    """
+
+    sockets = [
+        netns_socket(netns_list[0], socket.AF_RDS, socket.SOCK_SEQPACKET),
+        netns_socket(netns_list[1], socket.AF_RDS, socket.SOCK_SEQPACKET),
+    ]
+
+    for s, addr in zip(sockets, addrs):
+        s.bind(addr)
+        s.setblocking(0)
+
+    send_hashes = {}
+    recv_hashes = {}
+
+    ep = select.epoll()
+
+    for s in sockets:
+        ep.register(s, select.EPOLLRDNORM)
+
+    NUM_PACKETS = 50000
+    nr_send = 0
+    nr_recv = 0
+
+    while nr_send < NUM_PACKETS:
+
+        # Send as much as we can without blocking
+        ksft_pr("sending...", nr_send, nr_recv)
+        nr_send = send_burst(sockets, addrs, send_hashes, nr_send, NUM_PACKETS)
+
+        # Receive as much as we can without blocking
+        ksft_pr("receiving...", nr_send, nr_recv)
+        while nr_recv < nr_send:
+            nr_recv = recv_burst(ep, sockets, addrs, recv_hashes, nr_recv)
+
+        # exercise net/rds/tcp.c:rds_tcp_sysctl_reset()
+        for net in netns_list:
+            ip(f"netns exec {net} /usr/sbin/sysctl net.rds.tcp.rds_tcp_rcvbuf=10000")
+            ip(f"netns exec {net} /usr/sbin/sysctl net.rds.tcp.rds_tcp_sndbuf=10000")
+
+    ksft_pr("done", nr_send, nr_recv)
+
+    check_info(sockets)
+
+    # We're done sending and receiving stuff, now let's check if what
+    # we received is what we sent.
+    return verify_hashes(send_hashes, recv_hashes)
+
 def stop_pcaps():
     """Stop tcpdump processes.
 
@@ -267,7 +320,6 @@ PACKET_CORRUPTION=str(args.corruption)+'%'
 PACKET_DUPLICATE=str(args.duplicate)+'%'
 
 setup_tcp()
-addrs = tcp_addrs
 
 print("TAP version 13")
 print("1..1")
@@ -277,56 +329,13 @@ if args.timeout > 0:
     signal.alarm(args.timeout)
     signal.signal(signal.SIGALRM, signal_handler)
 
-sockets = [
-    netns_socket(NET0, socket.AF_RDS, socket.SOCK_SEQPACKET),
-    netns_socket(NET1, socket.AF_RDS, socket.SOCK_SEQPACKET),
-]
-
-for s, addr in zip(sockets, addrs):
-    s.bind(addr)
-    s.setblocking(0)
-
-send_hashes = {}
-recv_hashes = {}
-
-ep = select.epoll()
-
-for s in sockets:
-    ep.register(s, select.EPOLLRDNORM)
-
-NUM_PACKETS = 50000
-nr_send = 0
-nr_recv = 0
-
-while nr_send < NUM_PACKETS:
-
-    # Send as much as we can without blocking
-    ksft_pr("sending...", nr_send, nr_recv)
-    nr_send = send_burst(sockets, addrs, send_hashes, nr_send, NUM_PACKETS)
-
-    # Receive as much as we can without blocking
-    ksft_pr("receiving...", nr_send, nr_recv)
-    while nr_recv < nr_send:
-        nr_recv = recv_burst(ep, sockets, addrs, recv_hashes, nr_recv)
-
-    # exercise net/rds/tcp.c:rds_tcp_sysctl_reset()
-    for net in [NET0, NET1]:
-        ip(f"netns exec {net} /usr/sbin/sysctl net.rds.tcp.rds_tcp_rcvbuf=10000")
-        ip(f"netns exec {net} /usr/sbin/sysctl net.rds.tcp.rds_tcp_sndbuf=10000")
-
-ksft_pr("done", nr_send, nr_recv)
-
-check_info(sockets)
+RC = snd_rcv_packets(tcp_addrs, [NET0, NET1])
 
 # cancel timeout
 signal.alarm(0)
 
 stop_pcaps()
 
-# We're done sending and receiving stuff, now let's check if what
-# we received is what we sent.
-RC = verify_hashes(send_hashes, recv_hashes)
-
 if RC == 0:
     ksft_pr("Success")
     print("ok 1 rds selftest")
-- 
2.25.1