There are 2 interfaces in gVisor which are exactly the same:
- pkg/tcpip/stack.UniqueID
- pkg/sentry/uniqueid.Provider
Before this change, both were using the Kernel as the unique number generator.
However, we want to decouple the netstack from the kernel. This coupling is
causing bugs in restore because netstack needs to be created before the Kernel
is restored. So right now, netstack ends up using a "temporary" Kernel which is
later destroyed in the restore sequence, but netstack keeps referencing it.
Before this change, the unique ID generator in pkg/tcpip/stack.Stack was used
for 2 things:
1. Provide NIC IDs which are unique across all network namespaces.
2. Implement stack.TransportEndpoint.UniqueID.
(2) is not used anywhere, so deleted it. (1) is overly unique. NIC IDs do not
need to be unique across network namespace. So instead of holding a pointer to
the kernel, added a NIC ID generator in stack.Stack itself and added
NextNICID() function with proper typing.
PiperOrigin-RevId: 646997006
Implement the core part. All packets are broadcast-ed to all ports. The next
step will be to implement forwarding and multicast group databases.
PiperOrigin-RevId: 644471256
The veth devices are virtual Ethernet devices. They can act as
tunnels between network namespaces to create a bridge to a
physical network device in another namespace, but can also be
used as standalone network devices.
More information can be found here:
https://man7.org/linux/man-pages/man4/veth.4.html
PiperOrigin-RevId: 638853289
The NEWLINK commands contains many properties and here is no reason to have
another abstract interface between the Sentry and network stacks.
PiperOrigin-RevId: 627916629
Resume method resumes the endpoints after save which is required for
save/resume. This method resumes the endpoint states which were frozen during
save.
PiperOrigin-RevId: 615467468
The existing Resume method in netstack is doing the work of Restore. This
method does not resume endpoints as the resumable endpoints are only stored
during the Restore of the sandbox, rename the method appropriately.
PiperOrigin-RevId: 613320887
tcp_benchmark throughput increase 2-3%, but allocations go down (25% in the
download benchmark, only 2% in the upload path).
PiperOrigin-RevId: 532523146
The important change here is in tcpip/tcpip.go, where tcpip.Address is defined.
The rest is updating uses of tcpip.Address.
This is preparation for netip.Addr or []byte based addresses, which should save
us a bunch of allocations. Currently, we allocate every time we want to, say,
get a tcpip.Address from a header. This is because the header is a byte slice,
but Address is a string. Strings are immutable, so Go allocates and copies.
PiperOrigin-RevId: 532284732
Implement this check in netstack integration (in sentry) so that the
core netstack does not prevent an integrator from removing loopback.
PiperOrigin-RevId: 493992707
This change removes all endpoint goroutines and all TCP processing is now done
inline in the TCP processor loop. TCP timers directly invoke handlers as
required rather than assert a waker.
UnlockUser is also simplified to just queue the endpoint to the processor
instead of trying to process segments inline. This allows us to centralize logic
for TCP state handling in the processor. This potentially could involve an extra
wakeup but now that endpoint goroutines do not exist this is not such a big
concern as in case of busy servers the processor goroutines will already be
running anyway.
This change also allows us to clean up S/R as now restoring a TCP endpoint does
not require restarting a goroutine and moving it to the right logical point but
only requires that we restart any timers that may have been running when the
save was done and restore any port bindings as required.
Endpoint.Release is now removed in favor of Endpoint.Abort by using Abort in
places where we use Endpoint.Release.
Updates #231
PiperOrigin-RevId: 442673015
Replaced the current AddAddressWithOptions method with
AddAddressWithProperties which passes all address properties in
a single AddressProperties type. More properties that need to be
configured in the future are expected, so adding a type makes adding
them easier.
PiperOrigin-RevId: 396930729
This change will allow us to remove the default link in a packetimpact test so
we can reduce indeterministic behaviors as required in https://fxbug.dev/78430.
This will also help with testing #1388.
Updates #578, #1388.
PiperOrigin-RevId: 387896847
Remove three syserror entries duplicated in linuxerr. Because of the
linuxerr.Equals method, this is a mere change of return values from
syserror to linuxerr definitions.
Done with only these three errnos as CLs removing all grow to a significantly
large size.
PiperOrigin-RevId: 382173835
https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt:
/proc/sys/net/ipv4/* Variables:
ip_forward - BOOLEAN
0 - disabled (default)
not 0 - enabled
Forward Packets between interfaces.
This variable is special, its change resets all configuration
parameters to their default state (RFC1122 for hosts, RFC1812
for routers)
/proc/sys/net/ipv4/ip_forward only does work when its value is changed
and always returns the last written value. The last written value may
not reflect the current state of the netstack (e.g. when `ip_forward`
was written a value of "1" then disable forwarding on an interface)
so there is no need for sentry to probe netstack to get the current
forwarding state of interfaces.
```
~$ cat /proc/sys/net/ipv4/ip_forward
0
~$ sudo bash -c "echo 1 > /proc/sys/net/ipv4/ip_forward"
~$ cat /proc/sys/net/ipv4/ip_forward
1
~$ sudo sysctl -a | grep ipv4 | grep forward
net.ipv4.conf.all.forwarding = 1
net.ipv4.conf.default.forwarding = 1
net.ipv4.conf.eno1.forwarding = 1
net.ipv4.conf.lo.forwarding = 1
net.ipv4.conf.wlp1s0.forwarding = 1
net.ipv4.ip_forward = 1
net.ipv4.ip_forward_update_priority = 1
net.ipv4.ip_forward_use_pmtu = 0
~$ sudo sysctl -w net.ipv4.conf.wlp1s0.forwarding=0
net.ipv4.conf.wlp1s0.forwarding = 0
~$ sudo sysctl -a | grep ipv4 | grep forward
net.ipv4.conf.all.forwarding = 1
net.ipv4.conf.default.forwarding = 1
net.ipv4.conf.eno1.forwarding = 1
net.ipv4.conf.lo.forwarding = 1
net.ipv4.conf.wlp1s0.forwarding = 0
net.ipv4.ip_forward = 1
net.ipv4.ip_forward_update_priority = 1
net.ipv4.ip_forward_use_pmtu = 0
~$ cat /proc/sys/net/ipv4/ip_forward
1
~$ sudo bash -c "echo 1 > /proc/sys/net/ipv4/ip_forward"
~$ sudo sysctl -a | grep ipv4 | grep forward
net.ipv4.conf.all.forwarding = 1
net.ipv4.conf.default.forwarding = 1
net.ipv4.conf.eno1.forwarding = 1
net.ipv4.conf.lo.forwarding = 1
net.ipv4.conf.wlp1s0.forwarding = 0
net.ipv4.ip_forward = 1
net.ipv4.ip_forward_update_priority = 1
net.ipv4.ip_forward_use_pmtu = 0
~$ sudo bash -c "echo 0 > /proc/sys/net/ipv4/ip_forward"
~$ sudo sysctl -a | grep ipv4 | grep forward
sysctl: unable to open directory "/proc/sys/fs/binfmt_misc/"
net.ipv4.conf.all.forwarding = 0
net.ipv4.conf.default.forwarding = 0
net.ipv4.conf.eno1.forwarding = 0
net.ipv4.conf.lo.forwarding = 0
net.ipv4.conf.wlp1s0.forwarding = 0
net.ipv4.ip_forward = 0
net.ipv4.ip_forward_update_priority = 1
net.ipv4.ip_forward_use_pmtu = 0
~$ cat /proc/sys/net/ipv4/ip_forward
0
```
In the above example we can see that writing "1" to
/proc/sys/net/ipv4/ip_forward configures the stack to be a router (all
interfaces are configured to enable forwarding). However, if we manually
update an interace (`wlp1s0`) to not forward packets,
/proc/sys/net/ipv4/ip_forward continues to return the last written value
of "1", even though not all interfaces will forward packets.
Also note that writing the same value twice has no effect; work is
performed iff the value changes.
This change also removes the 'unset' state from sentry's ip forwarding
data structures as an 'unset' ip forwarding value is the same as leaving
forwarding disabled as the stack is always brought up with forwarding
initially disabled; disabling forwarding on a newly created stack is a
no-op.
PiperOrigin-RevId: 373853106
...to make it clear to callers that all interfaces are updated with the
forwarding flag and that future NICs will be created with the new
forwarding state.
PiperOrigin-RevId: 373618435
This change lets us split the v4 stats from the v6 stats, which will be
useful when adding stats for each network endpoint.
PiperOrigin-RevId: 345322615
The existing implementation for TransportProtocol.{Set}Option take
arguments of an empty interface type which all types (implicitly)
implement; any type may be passed to the functions.
This change introduces marker interfaces for transport protocol options
that may be set or queried which transport protocol option types
implement to ensure that invalid types are caught at compile time.
Different interfaces are used to allow the compiler to enforce read-only
or set-only socket options.
RELNOTES: n/a
PiperOrigin-RevId: 330559811
gVisor incorrectly returns the wrong ARP type for SIOGIFHWADDR. This breaks
tcpdump as it tries to interpret the packets incorrectly.
Similarly, SIOCETHTOOL is used by tcpdump to query interface properties which
fails with an EINVAL since we don't implement it. For now change it to return
EOPNOTSUPP to indicate that we don't support the query rather than return
EINVAL.
NOTE: ARPHRD types for link endpoints are distinct from NIC capabilities
and NIC flags. In Linux all 3 exist eg. ARPHRD types are stored in dev->type
field while NIC capabilities are more like the device features which can be
queried using SIOCETHTOOL but not modified and NIC Flags are fields that can
be modified from user space. eg. NIC status (UP/DOWN/MULTICAST/BROADCAST) etc.
Updates #2746
PiperOrigin-RevId: 321436525
Linux controls socket send/receive buffers using a few sysctl variables
- net.core.rmem_default
- net.core.rmem_max
- net.core.wmem_max
- net.core.wmem_default
- net.ipv4.tcp_rmem
- net.ipv4.tcp_wmem
The first 4 control the default socket buffer sizes for all sockets
raw/packet/tcp/udp and also the maximum permitted socket buffer that can be
specified in setsockopt(SOL_SOCKET, SO_(RCV|SND)BUF,...).
The last two control the TCP auto-tuning limits and override the default
specified in rmem_default/wmem_default as well as the max limits.
Netstack today only implements tcp_rmem/tcp_wmem and incorrectly uses it
to limit the maximum size in setsockopt() as well as uses it for raw/udp
sockets.
This changelist introduces the other 4 and updates the udp/raw sockets to use
the newly introduced variables. The values for min/max match the current
tcp_rmem/wmem values and the default value buffers for UDP/RAW sockets is
updated to match the linux value of 212KiB up from the really low current value
of 32 KiB.
Updates #3043Fixes#3043
PiperOrigin-RevId: 318089805
Metadata was useful for debugging and safety, but enough tests exist that we
should see failures when (de)serialization is broken. It made stack
initialization more cumbersome and it's also getting in the way of ip6tables.
PiperOrigin-RevId: 317210653
IPTables.connections contains a sync.RWMutex. Copying it will trigger copylocks
analysis. Tested by manually enabling nogo tests.
sync.RWMutex is added to IPTables for the additional race condition discovered.
PiperOrigin-RevId: 314817019
This is a precursor to be being able to build an intrusive list
of PacketBuffers for use in queuing disciplines being implemented.
Updates #2214
PiperOrigin-RevId: 302677662
CERT Advisory CA-96.21 III. Solution advises that devices drop packets which
could not have correctly arrived on the wire, such as receiving a packet where
the source IP address is owned by the device that sent it.
Fixes#1507
PiperOrigin-RevId: 290378240
In the future this will replace DanglingEndpoints. DanglingEndpoints must be
kept for now due to issues with save/restore.
This is arguably a cleaner design and allows the stack to know which transport
endpoints might still be using its link endpoints.
Updates #837
PiperOrigin-RevId: 277386633
Netstack has its own stats, we use this to fill /proc/net/snmp.
Note that some metrics are not recorded in Netstack, which will be shown
as 0 in the proc file.
Signed-off-by: Jianfeng Tan <[email protected]>
Change-Id: Ie0089184507d16f49bc0057b4b0482094417ebe1
