Add support for TIME_WAIT timeout.

This change adds explicit support for honoring the 2MSL timeout
for sockets in TIME_WAIT state. It also adds support for the
TCP_LINGER2 option that allows modification of the FIN_WAIT2
state timeout duration for a given socket.

It also adds an option to modify the Stack wide TIME_WAIT timeout
but this is only for testing. On Linux this is fixed at 60s.

Further, we also now correctly process RST's in CLOSE_WAIT and
close the socket similar to linux without moving it to error
state.

We also now handle SYN in ESTABLISHED state as per
RFC5961#section-4.1. Earlier we would just drop these SYNs.
Which can result in some tests that pass on linux to fail on
gVisor.

Netstack now honors TIME_WAIT correctly as well as handles the
following cases correctly.

- TCP RSTs in TIME_WAIT are ignored.
- A duplicate TCP FIN during TIME_WAIT extends the TIME_WAIT
  and a dup ACK is sent in response to the FIN as the dup FIN
  indicates potential loss of the original final ACK.
- An out of order segment during TIME_WAIT generates a dup ACK.
- A new SYN w/ a sequence number > the highest sequence number
  in the previous connection closes the TIME_WAIT early and
  opens a new connection.

Further to make the SYN case work correctly the ISN (Initial
Sequence Number) generation for Netstack has been updated to
be as per RFC. Its not a pure random number anymore and follows
the recommendation in https://tools.ietf.org/html/rfc6528#page-3.

The current hash used is not a cryptographically secure hash
function. A separate change will update the hash function used
to Siphash similar to what is used in Linux.

PiperOrigin-RevId: 279106406

1 files changed, 11 insertions, 11 deletions

diff --git a/test/syscalls/BUILD b/test/syscalls/BUILD
index 3e5b6b3c3..722d14b53 100644
--- a/test/syscalls/BUILD
+++ b/test/syscalls/BUILD
@@ -9,7 +9,7 @@ syscall_test(test = "//test/syscalls/linux:accept_bind_stream_test")
 
 syscall_test(
     size = "large",
-    shard_count = 10,
+    shard_count = 50,
     test = "//test/syscalls/linux:accept_bind_test",
 )
 
@@ -434,7 +434,7 @@ syscall_test(
 
 syscall_test(
     size = "large",
-    shard_count = 10,
+    shard_count = 50,
     test = "//test/syscalls/linux:socket_abstract_test",
 )
 
@@ -445,7 +445,7 @@ syscall_test(
 
 syscall_test(
     size = "large",
-    shard_count = 10,
+    shard_count = 50,
     test = "//test/syscalls/linux:socket_domain_test",
 )
 
@@ -458,19 +458,19 @@ syscall_test(
 syscall_test(
     size = "large",
     add_overlay = True,
-    shard_count = 10,
+    shard_count = 50,
     test = "//test/syscalls/linux:socket_filesystem_test",
 )
 
 syscall_test(
     size = "large",
-    shard_count = 10,
+    shard_count = 50,
     test = "//test/syscalls/linux:socket_inet_loopback_test",
 )
 
 syscall_test(
     size = "large",
-    shard_count = 10,
+    shard_count = 50,
     test = "//test/syscalls/linux:socket_ip_tcp_generic_loopback_test",
 )
 
@@ -481,13 +481,13 @@ syscall_test(
 
 syscall_test(
     size = "large",
-    shard_count = 10,
+    shard_count = 50,
     test = "//test/syscalls/linux:socket_ip_tcp_loopback_test",
 )
 
 syscall_test(
     size = "medium",
-    shard_count = 10,
+    shard_count = 50,
     test = "//test/syscalls/linux:socket_ip_tcp_udp_generic_loopback_test",
 )
 
@@ -498,7 +498,7 @@ syscall_test(
 
 syscall_test(
     size = "large",
-    shard_count = 10,
+    shard_count = 50,
     test = "//test/syscalls/linux:socket_ip_udp_loopback_test",
 )
 
@@ -560,7 +560,7 @@ syscall_test(
 syscall_test(
     size = "large",
     add_overlay = True,
-    shard_count = 10,
+    shard_count = 50,
     test = "//test/syscalls/linux:socket_unix_pair_test",
 )
 
@@ -599,7 +599,7 @@ syscall_test(
 
 syscall_test(
     size = "large",
-    shard_count = 10,
+    shard_count = 50,
     test = "//test/syscalls/linux:socket_unix_unbound_stream_test",
 )