Incrementing the reference count of a packet as a means of granting ownership
is unsafe when the packet is shared across gorountines. The underlying buffer's
reference count is unchanged since it "technically" has the same owning
PacketBuffer, which means different goroutines operating on the underlying
buffer (and packet itself) race.
Clones are roughly as fast as IncRefs because the PacketBuffers allocate from
a pool and the underlying buffers are cloned with copy-on-write
semantics.
I've left IncRef in places where the original packet in obviously going out of
scope at the end of the function or in some tests.
Reported-by: syzbot+e026046f4bf8ad09ae1f@syzkaller.appspotmail.com
Reported-by: syzbot+559365d6050db4b30e0f@syzkaller.appspotmail.com
Reported-by: syzbot+63c78a2c88a5744c636b@syzkaller.appspotmail.com
PiperOrigin-RevId: 705676806
This CL restores the listening connections when netstack s/r is enabled.
The changes include:
- New method as a workaround to replace the new routes and nics to the loaded
stack after restore.
- New Restore() for transport layer protocols to restore the protocol level
background workers.
- Adds afterLoad() method for fdbased processors.
- Adds a test to verify listening connection is restored after checkpointing
with netstack s/r enabled.
- Few other changes to save restore fields to enable netstack s/r.
PiperOrigin-RevId: 698453124
The helper function is deprecated. The package gvisor.dev/gvisor/pkg/rand
depends on crypto/rand which performs worse thatn math/rand, the changes
are fine since they are not at any gVisor's hot path.
The ultimate goal is to migrate math/rand to math/rand/v2.
L2 MTU includes both payload and ethernet header. gVisor has supported setting
data link layer MTU, it will be up to users to set up proper value for a
device's MTU if a larger value is expected.
By doing the change, gVisor will be consistent with runc:
```shell
# runc
root@cec4d7238802:/# ip link set dev lo mtu 1234
root@cec4d7238802:/# ip link list dev lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 1234 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
# runsc before the change.
root@7cd89278d414:/# ip link set dev lo mtu 1234
root@7cd89278d414:/# ip link list dev lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 1220
link/loopback 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
# runsc after the change.
root@e811c5851226:/# ip link set dev lo mtu 1234
root@e811c5851226:/# ip link list dev lo
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 1234
link/loopback 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
```
PiperOrigin-RevId: 684746090
This was always set to 1, with the deteriminant of whether to log PCAP output
instead being whether `sniffer.Endpoint.writer` was non-nil. There's no reason
to keep it around.
PiperOrigin-RevId: 675712237
We weren't verifying that inbound MAC addresses match the NIC, which led to
netstack ingesting packets not meant for it.
Fixes#10908.
PiperOrigin-RevId: 675330632
recvMMsgDispatcher.msgHdrs is not required to be saved across s/r, mark it as
nosave and make changes to re-initialize it after restore.
PiperOrigin-RevId: 673859213
- Adds a new flag which will enable netstack s/r. When the flag is not enabled,
there is no change in the existing behavior. The flag will be enabled only in
tests to verify the s/r functionality of netstack.
- Some additional fields in netstack were causing panic when netstack is
save/restored. Such fields are marked as 'save'/'nosave' accordingly to resolve
the panic.
PiperOrigin-RevId: 668566657
Our Bazel build infrastructure explicitly recognizes some suffixes that can
appear at the end of filenames (tools/bazeldefs/tags.bzl). It uses these tags
to group files passed to go_stateify (tools/defs.bzl:go_library() =>
calculate_sets()).
Each invocation of go_stateify infers build tags from its input files. Before
this CL, all Go files in pkg/tcpip/link/fdbased (except for fdbased_unsafe.go)
are grouped together to generate fdbased_state_autogen.go, so go_stateify
infers builds tags "!linux !amd64,!arm64" (from mmap_stub.go) and "linux ..."
(from most other files); these contradictory build tags mean that
fdbased_state_autogen.go is never actually compiled, preventing its types from
being registered. After this CL, mmap_nonlinux.go independently generates
fdbased_nonlinux_state_autogen.go.
Fixing this causes fdbased_state_autogen.go to be included for the first time,
exposing a second problem:
```
pkg/tcpip/link/fdbased/endpoint_test.go:80:6: context already declared through import of package context ("context")
.../pkg/tcpip/link/fdbased/fdbased_state_autogen.go:12:2: other declaration of context
```
(Apparently Go imports are a pessimal hybrid of "shared between files in a
package" and "not shared between files in a package".) To fix this, rename the
test type to testContext.
PiperOrigin-RevId: 663522480
While testing docker-in-gvisor, we found that veth devices with enabled
CapabilityTXChecksumOffload don't work as expected. Packets issued from the
gvisor sandbox have incorrect checksum-s.
PiperOrigin-RevId: 651157380
The buffers from the buffer package are meant to be copy-on-write, but IP
headers still work with the underlying []byte, so writes are not tracked.
This allows data races in situations where packet buffers are shared
across goroutines.
PiperOrigin-RevId: 650429239
Ayush RanjanandgVisor bot
Lucas ManningandgVisor bot
Jing ChenandgVisor bot
Nayana BidariandgVisor bot
Andrei VaginandgVisor bot
Jing Chen
Koichi Shiraishi
Kevin KrakauerandgVisor bot
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