From 9974803f431fa20def40a78e241e4736dc00773d Mon Sep 17 00:00:00 2001
From: iosabi <iosabi@protonmail.com>
Date: Sat, 10 Apr 2021 18:56:12 +0200
Subject: [PATCH] tests/lwip: Add a test for partial TCP reads.

Add a new test to check the behavior of `sock_tcp_read` when more data
is available in the connection than the buffer passed. This test checks
issue #16124 as well as reading from multiple small network packets into
a single buffer.
---
 tests/lwip/tests/01-run.py | 52 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 51 insertions(+), 1 deletion(-)

diff --git a/tests/lwip/tests/01-run.py b/tests/lwip/tests/01-run.py
index 0f96dc6593..e1375f7b66 100755
--- a/tests/lwip/tests/01-run.py
+++ b/tests/lwip/tests/01-run.py
@@ -275,6 +275,55 @@ def test_tcpv6_send(board_group, application, env=None):
         client.expect_exact(u"could not send")
 
 
+def test_tcpv6_large_send(board_group, application, env=None):
+    """Test that the TCP server can receive a large packet in multiple reads"""
+    if any(b.name != "native" for b in board_group.boards):
+        # run test only with native
+        print("SKIP_TEST INFO found non-native board")
+        return
+    env_server = os.environ.copy()
+    if env is not None:
+        env_server.update(env)
+    env_server.update(board_group.boards[1].to_env())
+    with pexpect.spawnu(MAKE, ["-C", application, "term"], env=env_server,
+                        timeout=DEFAULT_TIMEOUT) as server:
+        port = random.randint(0x0000, 0xffff)
+        server_ip = get_ipv6_address(server)
+
+        try:
+            connect_addr = socket.getaddrinfo(
+                "%s%%tapbr0" % server_ip, port)[0][4]
+        except socket.gaierror as e:
+            print("SKIP_TEST INFO", e)
+            return
+
+        server.sendline(u"tcp server start %d" % port)
+        # wait for neighbor discovery to be done
+        time.sleep(5)
+
+        # Send large amount of data to verify multiple reads.
+        with socket.socket(socket.AF_INET6) as sock:
+            sock.connect(connect_addr)
+            server.expect(u"TCP client \\[[0-9a-f:]+\\]:[0-9]+ connected")
+            # Default read size in tcp.c SOCK_INBUF_SIZE (256 bytes), so this
+            # is at least 3 reads.
+            data = bytearray(random.randint(0, 255) for i in range(608))
+            sock.send(data)
+
+            def data_line(i):
+                return u'  '.join(u'%.2X' % data[i + j] for j in range(16))
+            # We expect three consecutive reads of 256 byte buffer to print the
+            # data at positions 0, 256 and 512.
+            server.expect(u"00000000  %s" % data_line(0))
+            server.expect(u"00000000  %s" % data_line(256))
+            server.expect(u"00000000  %s" % data_line(512))
+            # Last line of the message should be on the third read call,
+            # together with the rest of the third read.
+            server.expect(u"00000050  %s" % data_line(len(data) - 16))
+            sock.close()
+            server.expect(u"TCP connection to \\[[0-9a-f:]+\\]:[0-9]+ reset")
+
+
 def test_tcpv6_multiconnect(board_group, application, env=None):
     if any(b.name != "native" for b in board_group.boards):
         # run test only with native
@@ -366,4 +415,5 @@ if __name__ == "__main__":
     TestStrategy().execute([BoardGroup((Board("native", "tap0"),
                             Board("native", "tap1")))],
                            [test_ipv6_send, test_udpv6_send, test_tcpv6_send,
-                            test_tcpv6_multiconnect, test_triple_send])
+                            test_tcpv6_large_send, test_tcpv6_multiconnect,
+                            test_triple_send])