Non-primary addresses are used for endpoints created to accept multicast and
broadcast packets, as well as "helper" endpoints (0.0.0.0) that allow sending
packets when no proper address has been assigned yet (e.g., for DHCP). These
addresses are not real addresses from a user point of view and should not be
part of the NICInfo() value. Also see b/127321246 for more info.
This switches NICInfo() to call a new NIC.PrimaryAddresses() function. To still
allow an option to get all addresses (mostly for testing) I added
Stack.GetAllAddresses() and NIC.AllAddresses().
In addition, the return value for GetMainNICAddress() was changed for the case
where the NIC has no primary address. Instead of returning an error here,
it now returns an empty AddressWithPrefix() value. The rational for this
change is that it is a valid case for a NIC to have no primary addresses.
Lastly, I refactored the code based on the new additions.
PiperOrigin-RevId: 270971764
The IPv6 all-nodes multicast address will be joined on NIC enable, and the
appropriate IPv6 solicited-node multicast address will be joined when IPv6
addresses are added.
Tests: Test receiving packets destined to the IPv6 link-local all-nodes
multicast address and the IPv6 solicted node address of an added IPv6 address.
PiperOrigin-RevId: 268047073
This also renames "subnet" to "addressRange" to avoid any more confusion with
an interface IP's subnet.
Lastly, this also removes the Stack.ContainsSubnet(..) API since it isn't used
by anyone. Plus the same information can be obtained from
Stack.NICAddressRanges().
PiperOrigin-RevId: 267229843
Adds support to generate Port Unreachable messages for UDP
datagrams received on a port for which there is no valid
endpoint.
Fixes#703
PiperOrigin-RevId: 267034418
Endpoint protocol goroutines were previously started as part of
loading the endpoint. This is potentially too soon, as resources used
by these goroutine may not have been loaded. Protocol goroutines may
perform meaningful work as soon as they're started (ex: incoming
connect) which can cause them to indirectly access resources that
haven't been loaded yet.
This CL defers resuming all protocol goroutines until the end of
restore.
PiperOrigin-RevId: 262409429
This allows the user code to add a network address with a subnet prefix length.
The prefix length value is stored in the network endpoint and provided back to
the user in the ProtocolAddress type.
PiperOrigin-RevId: 259807693
iptables also relies on IPPROTO_RAW in a way. It opens such a socket to
manipulate the kernel's tables, but it doesn't actually use any of the
functionality. Blegh.
PiperOrigin-RevId: 257903078
The implementation is similar to linux where we track the number of bytes
consumed by the application to grow the receive buffer of a given TCP endpoint.
This ensures that the advertised window grows at a reasonable rate to accomodate
for the sender's rate and prevents large amounts of data being held in stack
buffers if the application is not actively reading or not reading fast enough.
The original paper that was used to implement the linux receive buffer auto-
tuning is available @ https://public.lanl.gov/radiant/pubs/drs/lacsi2001.pdf
NOTE: Linux does not implement DRS as defined in that paper, it's just a good
reference to understand the solution space.
Updates #230
PiperOrigin-RevId: 253168283
This requires two changes:
1) Support for more than one socket to join a given multicast group.
2) Duplicate delivery of incoming multicast packets to all sockets listening
for it.
In addition, I tweaked the code (and added a test) to disallow duplicates
IP_ADD_MEMBERSHIP calls for the same group and NIC. This is how Linux does
it.
PiperOrigin-RevId: 246437315
Change-Id: Icad8300b4a8c3f501d9b4cd283bd3beabef88b72
Based on the guidelines at
https://opensource.google.com/docs/releasing/authors/.
1. $ rg -l "Google LLC" | xargs sed -i 's/Google LLC.*/The gVisor Authors./'
2. Manual fixup of "Google Inc" references.
3. Add AUTHORS file. Authors may request to be added to this file.
4. Point netstack AUTHORS to gVisor AUTHORS. Drop CONTRIBUTORS.
Fixes#209
PiperOrigin-RevId: 245823212
Change-Id: I64530b24ad021a7d683137459cafc510f5ee1de9
Having raw socket code together will make it easier to add support for other raw
network protocols. Currently, only ICMP uses the raw endpoint. However, adding
support for other protocols such as UDP shouldn't be much more difficult than
adding a few switch cases.
PiperOrigin-RevId: 241564875
Change-Id: I77e03adafe4ce0fd29ba2d5dfdc547d2ae8f25bf
HandleLocal is very similar conceptually to MULTICAST_LOOP, so we can unify
the implementations. This has the benefit of making HandleLocal apply even when
the fdbased link endpoint isn't in use.
In addition, move looping logic to route creation so that it doesn't need to be
run for each packet. This should improve performance.
PiperOrigin-RevId: 238099480
Change-Id: I72839f16f25310471453bc9d3fb8544815b25c23
IP_MULTICAST_LOOP controls whether or not multicast packets sent on the default
route are looped back. In order to implement this switch, support for sending
and looping back multicast packets on the default route had to be implemented.
For now we only support IPv4 multicast.
PiperOrigin-RevId: 237534603
Change-Id: I490ac7ff8e8ebef417c7eb049a919c29d156ac1c
...in accordance with RFCs 1112 and 2464.
Fixes IPv4 multicast when IP_MULTICAST_IF is specified.
Don't return ErrNoRoute when no route is needed.
Don't set Route.NextHop when no route is needed.
PiperOrigin-RevId: 236199813
Change-Id: I48ed33e1b7f760deaa37e18ad7f1b8b62819ab43
Broadly, this change:
* Enables sockets to be created via `socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)`.
* Passes the network-layer (IP) header up the stack to the transport endpoint,
which can pass it up to the socket layer. This allows a raw socket to return
the entire IP packet to users.
* Adds functions to stack.TransportProtocol, stack.Stack, stack.transportDemuxer
that enable incoming packets to be delivered to raw endpoints. New raw sockets
of other protocols (not ICMP) just need to register with the stack.
* Enables ping.endpoint to return IP headers when created via SOCK_RAW.
PiperOrigin-RevId: 235993280
Change-Id: I60ed994f5ff18b2cbd79f063a7fdf15d093d845a
This allows setting a default send interface for IPv4 multicast. IPv6 support
will come later.
PiperOrigin-RevId: 234251379
Change-Id: I65922341cd8b8880f690fae3eeb7ddfa47c8c173
Also includes a few fixes for IPv4 multicast support. IPv6 support is coming in
a followup CL.
PiperOrigin-RevId: 233008638
Change-Id: If7dae6222fef43fda48033f0292af77832d95e82
This option allows multiple sockets to be bound to the same port.
Incoming packets are distributed to sockets using a hash based on source and
destination addresses. This means that all packets from one sender will be
received by the same server socket.
PiperOrigin-RevId: 227153413
Change-Id: I59b6edda9c2209d5b8968671e9129adb675920cf
Same as with broadcast packets, sending of a multicast packet shouldn't require
accessing the route table. The same applies to IPv6 link-local addresses, which
aren't routable at all (they don't belong to any subnet by definition).
PiperOrigin-RevId: 225775870
Change-Id: Ic53e6560c125a83be2be9c3d112e66b36e8dfe7b
Currently sending a broadcast packet (for DHCP, e.g.) requires a "default
route" of the format "0.0.0.0/0 via 0.0.0.0 <intf>". There is no good reason
for this and on devices with several ports this creates a rather akward route
table with lots of such default routes (which defeats the purpose of a default
route).
PiperOrigin-RevId: 224378769
Change-Id: Icd7ec8a206eb08083cff9a837f6f9ab231c73a19
Previously, if address resolution for UDP or Ping sockets required sending
packets using Write in Transport layer, Resolve would return ErrWouldBlock
and Write would return ErrNoLinkAddress. Meanwhile startAddressResolution
would run in background. Further calls to Write using same address would also
return ErrNoLinkAddress until resolution has been completed successfully.
Since Write is not allowed to block and System Calls need to be
interruptible in System Call layer, the caller to Write is responsible for
blocking upon return of ErrWouldBlock.
Now, when startAddressResolution is called a notification channel for
the completion of the address resolution is returned.
The channel will traverse up to the calling function of Write as well as
ErrNoLinkAddress. Once address resolution is complete (success or not) the
channel is closed. The caller would call Write again to send packets and
check if address resolution was compeleted successfully or not.
Fixesgoogle/gvisor#5
Change-Id: Idafaf31982bee1915ca084da39ae7bd468cebd93
PiperOrigin-RevId: 214962200
Add option to redirect packet back to netstack if it's destined to itself.
This fixes the problem where connecting to the local NIC address would
not work, e.g.:
echo bar | nc -l -p 8080 &
echo foo | nc 192.168.0.2 8080
PiperOrigin-RevId: 207995083
Change-Id: I17adc2a04df48bfea711011a5df206326a1fb8ef