diff options
| author | Ian Gudger <igudger@google.com> | 2020-03-03 13:40:59 -0800 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2020-03-03 13:42:13 -0800 |
| commit | c15b8515eb4a07699e5f2401f0332286f0a51043 (patch) | |
| tree | 88ddd70d54388e3b1947b87490f45846f3fdf656 /pkg/tcpip/stack | |
| parent | b3c549d8391e7cadd82a5ab9280bc63bb372aa97 (diff) | |
Fix datarace on TransportEndpointInfo.ID and clean up semantics.
Ensures that all access to TransportEndpointInfo.ID is either:
* In a function ending in a Locked suffix.
* While holding the appropriate mutex.
This primary affects the checkV4Mapped method on affected endpoints, which has
been renamed to checkV4MappedLocked. Also document the method and change its
argument to be a value instead of a pointer which had caused some awkwardness.
This race was possible in the udp and icmp endpoints between Connect and uses
of TransportEndpointInfo.ID including in both itself and Bind.
The tcp endpoint did not suffer from this bug, but benefited from better
documentation.
Updates #357
PiperOrigin-RevId: 298682913
Diffstat (limited to 'pkg/tcpip/stack')
| -rw-r--r-- | pkg/tcpip/stack/stack.go | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go index ebb6c5e3b..13354d884 100644 --- a/pkg/tcpip/stack/stack.go +++ b/pkg/tcpip/stack/stack.go @@ -551,11 +551,13 @@ type TransportEndpointInfo struct { RegisterNICID tcpip.NICID } -// AddrNetProto unwraps the specified address if it is a V4-mapped V6 address -// and returns the network protocol number to be used to communicate with the -// specified address. It returns an error if the passed address is incompatible -// with the receiver. -func (e *TransportEndpointInfo) AddrNetProto(addr tcpip.FullAddress, v6only bool) (tcpip.FullAddress, tcpip.NetworkProtocolNumber, *tcpip.Error) { +// AddrNetProtoLocked unwraps the specified address if it is a V4-mapped V6 +// address and returns the network protocol number to be used to communicate +// with the specified address. It returns an error if the passed address is +// incompatible with the receiver. +// +// Preconditon: the parent endpoint mu must be held while calling this method. +func (e *TransportEndpointInfo) AddrNetProtoLocked(addr tcpip.FullAddress, v6only bool) (tcpip.FullAddress, tcpip.NetworkProtocolNumber, *tcpip.Error) { netProto := e.NetProto switch len(addr.Addr) { case header.IPv4AddressSize: |