This is required to implement O_TRUNC correctly on filesystems backed by
gofers.
9P2000.L: "lopen prepares fid for file I/O. flags contains Linux open(2) flags
bits, e.g. O_RDONLY, O_RDWR, O_WRONLY."
open(2): "The argument flags must include one of the following access modes:
O_RDONLY, O_WRONLY, or O_RDWR. ... In addition, zero or more file creation
flags and file status flags can be bitwise-or'd in flags."
The reference 9P2000.L implementation also appears to expect arbitrary flags,
not just access modes, in Tlopen.flags:
https://github.com/chaos/diod/blob/master/diod/ops.c#L703
PiperOrigin-RevId: 278972683
This change allows the netstack to do NDP's Router Discovery as outlined by
RFC 4861 section 6.3.4.
Note, this change will not break existing uses of netstack as the default
configuration for the stack options is set in such a way that Router Discovery
will not be performed. See `stack.Options` and `stack.NDPConfigurations` for
more details.
This change introduces 2 options required to take advantage of Router Discovery,
all available under NDPConfigurations:
- HandleRAs: Whether or not NDP RAs are processes
- DiscoverDefaultRouters: Whether or not Router Discovery is performed
Another note: for a NIC to process Router Advertisements, it must not be a
router itself. Currently the netstack does not have per-interface routing
configuration; the routing/forwarding configuration is controlled stack-wide.
Therefore, if the stack is configured to enable forwarding/routing, no Router
Advertisements will be processed.
Tests: Unittest to make sure that Router Discovery and updates to the routing
table only occur if explicitly configured to do so. Unittest to make sure at
max stack.MaxDiscoveredDefaultRouters discovered default routers are remembered.
PiperOrigin-RevId: 278965143
This change better follows what is outlined in RFC 793 section 3.4 figure 12
where a listening socket should not accept a SYN-ACK segment in response to a
(potentially) old SYN segment.
Tests: Test that checks the TCP RST segment sent in response to a TCP SYN-ACK
segment received on a listening TCP endpoint.
PiperOrigin-RevId: 278893114
This change validates incoming NDP Router Advertisements as per RFC 4861 section
6.1.2. It also includes the skeleton to handle Router Advertiements that arrive
on some NIC.
Tests: Unittest to make sure only valid NDP Router Advertisements are received/
not dropped.
PiperOrigin-RevId: 278891972
This fixes a number of issues with the repository build process:
* Fix the overall structure of the repository.
* Fix the debian package description.
* Fix the broken version number for packages.
* Update the digest algorithm used for signing the release.
I've validated that installation works from a separate staging bucket.
Updates #852
PiperOrigin-RevId: 278716914
NETLINK_KOBJECT_UEVENT sockets send udev-style messages for device events.
gVisor doesn't have any device events, so our sockets don't need to do anything
once created.
systemd's device manager needs to be able to create one of these sockets. It
also wants to install a BPF filter on the socket. Since we'll never send any
messages, the filter would never be invoked, thus we just fake it out.
Fixes#1117
Updates #1119
PiperOrigin-RevId: 278405893
Since we only supporting sending messages from the kernel, the peer is always
the kernel, simplifying handling.
There are currently no known users of SO_PASSCRED that would actually receive
messages from gVisor, but adding full support is barely more work than stubbing
out fake support.
Updates #1117Fixes#1119
PiperOrigin-RevId: 277981465
The watchdog currently can find stuck tasks, but has no way to tell if the
sandbox is stuck before the application starts executing.
This CL adds a startup timeout and action to the watchdog. If Start() is not
called before the given timeout (if non-zero), then the watchdog will take the
action.
PiperOrigin-RevId: 277970577
Adds a systemd-cgroup flag option that prints an error letting the user know
that systemd cgroups are not supported and points them to the relevant issue.
Issue #193
PiperOrigin-RevId: 277837162