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| -rw-r--r-- | test/packetimpact/dut/BUILD | 18 | ||||
| -rw-r--r-- | test/packetimpact/dut/posix_server.cc | 229 | ||||
| -rw-r--r-- | test/packetimpact/proto/BUILD | 12 | ||||
| -rw-r--r-- | test/packetimpact/proto/posix_server.proto | 150 | ||||
| -rw-r--r-- | test/packetimpact/testbench/BUILD | 31 | ||||
| -rw-r--r-- | test/packetimpact/testbench/connections.go | 245 | ||||
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| -rw-r--r-- | test/packetimpact/testbench/dut_client.go | 28 | ||||
| -rw-r--r-- | test/packetimpact/testbench/layers.go | 507 | ||||
| -rw-r--r-- | test/packetimpact/testbench/rawsockets.go | 151 | ||||
| -rw-r--r-- | test/packetimpact/tests/BUILD | 21 | ||||
| -rw-r--r-- | test/packetimpact/tests/Dockerfile | 5 | ||||
| -rw-r--r-- | test/packetimpact/tests/defs.bzl | 106 | ||||
| -rw-r--r-- | test/packetimpact/tests/fin_wait2_timeout_test.go | 68 | ||||
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diff --git a/test/packetimpact/README.md b/test/packetimpact/README.md new file mode 100644 index 000000000..ece4dedc6 --- /dev/null +++ b/test/packetimpact/README.md @@ -0,0 +1,531 @@ +# Packetimpact + +## What is packetimpact? + +Packetimpact is a tool for platform-independent network testing. It is heavily +inspired by [packetdrill](https://github.com/google/packetdrill). It creates two +docker containers connected by a network. One is for the test bench, which +operates the test. The other is for the device-under-test (DUT), which is the +software being tested. The test bench communicates over the network with the DUT +to check correctness of the network. + +### Goals + +Packetimpact aims to provide: + +* A **multi-platform** solution that can test both Linux and gVisor. +* **Conciseness** on par with packetdrill scripts. +* **Control-flow** like for loops, conditionals, and variables. +* **Flexibilty** to specify every byte in a packet or use multiple sockets. + +## When to use packetimpact? + +There are a few ways to write networking tests for gVisor currently: + +* [Go unit tests](https://github.com/google/gvisor/tree/master/pkg/tcpip) +* [syscall tests](https://github.com/google/gvisor/tree/master/test/syscalls/linux) +* [packetdrill tests](https://github.com/google/gvisor/tree/master/test/packetdrill) +* packetimpact tests + +The right choice depends on the needs of the test. + +Feature | Go unit test | syscall test | packetdrill | packetimpact +------------- | ------------ | ------------ | ----------- | ------------ +Multiplatform | no | **YES** | **YES** | **YES** +Concise | no | somewhat | somewhat | **VERY** +Control-flow | **YES** | **YES** | no | **YES** +Flexible | **VERY** | no | somewhat | **VERY** + +### Go unit tests + +If the test depends on the internals of gVisor and doesn't need to run on Linux +or other platforms for comparison purposes, a Go unit test can be appropriate. +They can observe internals of gVisor networking. The downside is that they are +**not concise** and **not multiplatform**. If you require insight on gVisor +internals, this is the right choice. + +### Syscall tests + +Syscall tests are **multiplatform** but cannot examine the internals of gVisor +networking. They are **concise**. They can use **control-flow** structures like +conditionals, for loops, and variables. However, they are limited to only what +the POSIX interface provides so they are **not flexible**. For example, you +would have difficulty writing a syscall test that intentionally sends a bad IP +checksum. Or if you did write that test with raw sockets, it would be very +**verbose** to write a test that intentionally send wrong checksums, wrong +protocols, wrong sequence numbers, etc. + +### Packetdrill tests + +Packetdrill tests are **multiplatform** and can run against both Linux and +gVisor. They are **concise** and use a special packetdrill scripting language. +They are **more flexible** than a syscall test in that they can send packets +that a syscall test would have difficulty sending, like a packet with a +calcuated ACK number. But they are also somewhat limimted in flexibiilty in that +they can't do tests with multiple sockets. They have **no control-flow** ability +like variables or conditionals. For example, it isn't possible to send a packet +that depends on the window size of a previous packet because the packetdrill +language can't express that. Nor could you branch based on whether or not the +other side supports window scaling, for example. + +### Packetimpact tests + +Packetimpact tests are similar to Packetdrill tests except that they are written +in Go instead of the packetdrill scripting language. That gives them all the +**control-flow** abilities of Go (loops, functions, variables, etc). They are +**multiplatform** in the same way as packetdrill tests but even more +**flexible** because Go is more expressive than the scripting language of +packetdrill. However, Go is **not as concise** as the packetdrill language. Many +design decisions below are made to mitigate that. + +## How it works + +``` + +--------------+ +--------------+ + | | TEST NET | | + | | <===========> | Device | + | Test | | Under | + | Bench | | Test | + | | <===========> | (DUT) | + | | CONTROL NET | | + +--------------+ +--------------+ +``` + +Two docker containers are created by a script, one for the test bench and the +other for the device under test (DUT). The script connects the two containers +with a control network and test network. It also does some other tasks like +waiting until the DUT is ready before starting the test and disabling Linux +networking that would interfere with the test bench. + +### DUT + +The DUT container runs a program called the "posix_server". The posix_server is +written in c++ for maximum portability. It is compiled on the host. The script +that starts the containers copies it into the DUT's container and runs it. It's +job is to receive directions from the test bench on what actions to take. For +this, the posix_server does three steps in a loop: + +1. Listen for a request from the test bench. +2. Execute a command. +3. Send the response back to the test bench. + +The requests and responses are +[protobufs](https://developers.google.com/protocol-buffers) and the +communication is done with [gRPC](https://grpc.io/). The commands run are +[POSIX socket commands](https://en.wikipedia.org/wiki/Berkeley_sockets#Socket_API_functions), +with the inputs and outputs converted into protobuf requests and responses. All +communication is on the control network, so that the test network is unaffected +by extra packets. + +For example, this is the request and response pair to call +[`socket()`](http://man7.org/linux/man-pages/man2/socket.2.html): + +```protocol-buffer +message SocketRequest { + int32 domain = 1; + int32 type = 2; + int32 protocol = 3; +} + +message SocketResponse { + int32 fd = 1; + int32 errno_ = 2; +} +``` + +##### Alternatives considered + +* We could have use JSON for communication instead. It would have been a + lighter-touch than protobuf but protobuf handles all the data type and has + strict typing to prevent a class of errors. The test bench could be written + in other languages, too. +* Instead of mimicking the POSIX interfaces, arguments could have had a more + natural form, like the `bind()` getting a string IP address instead of bytes + in a `sockaddr_t`. However, conforming to the existing structures keeps more + of the complexity in Go and keeps the posix_server simpler and thus more + likely to compile everywhere. + +### Test Bench + +The test bench does most of the work in a test. It is a Go program that compiles +on the host and is copied by the script into test bench's container. It is a +regular [go unit test](https://golang.org/pkg/testing/) that imports the test +bench framework. The test bench framwork is based on three basic utilities: + +* Commanding the DUT to run POSIX commands and return responses. +* Sending raw packets to the DUT on the test network. +* Listening for raw packets from the DUT on the test network. + +#### DUT commands + +To keep the interface to the DUT consistent and easy-to-use, each POSIX command +supported by the posix_server is wrapped in functions with signatures similar to +the ones in the [Go unix package](https://godoc.org/golang.org/x/sys/unix). This +way all the details of endianess and (un)marshalling of go structs such as +[unix.Timeval](https://godoc.org/golang.org/x/sys/unix#Timeval) is handled in +one place. This also makes it straight-forward to convert tests that use `unix.` +or `syscall.` calls to `dut.` calls. + +For example, creating a connection to the DUT and commanding it to make a socket +looks like this: + +```go +dut := testbench.NewDut(t) +fd, err := dut.SocketWithErrno(unix.AF_INET, unix.SOCK_STREAM, unix.IPPROTO_IP) +if fd < 0 { + t.Fatalf(...) +} +``` + +Because the usual case is to fail the test when the DUT fails to create a +socket, there is a concise version of each of the `...WithErrno` functions that +does that: + +```go +dut := testbench.NewDut(t) +fd := dut.Socket(unix.AF_INET, unix.SOCK_STREAM, unix.IPPROTO_IP) +``` + +The DUT and other structs in the code store a `*testing.T` so that they can +provide versions of functions that call `t.Fatalf(...)`. This helps keep tests +concise. + +##### Alternatives considered + +* Instead of mimicking the `unix.` go interface, we could have invented a more + natural one, like using `float64` instead of `Timeval`. However, using the + same function signatures that `unix.` has makes it easier to convert code to + `dut.`. Also, using an existing interface ensures that we don't invent an + interface that isn't extensible. For example, if we invented a function for + `bind()` that didn't support IPv6 and later we had to add a second `bind6()` + function. + +#### Sending/Receiving Raw Packets + +The framework wraps POSIX sockets for sending and receiving raw frames. Both +send and receive are synchronous commands. +[SO_RCVTIMEO](http://man7.org/linux/man-pages/man7/socket.7.html) is used to set +a timeout on the receive commands. For ease of use, these are wrapped in an +`Injector` and a `Sniffer`. They have functions: + +```go +func (s *Sniffer) Recv(timeout time.Duration) []byte {...} +func (i *Injector) Send(b []byte) {...} +``` + +##### Alternatives considered + +* [gopacket](https://github.com/google/gopacket) pcap has raw socket support + but requires cgo. cgo is not guaranteed to be portable from the host to the + container and in practice, the container doesn't recognize binaries built on + the host if they use cgo. +* Both gVisor and gopacket have the ability to read and write pcap files + without cgo but that is insufficient here. +* The sniffer and injector can't share a socket because they need to be bound + differently. +* Sniffing could have been done asynchronously with channels, obviating the + need for `SO_RCVTIMEO`. But that would introduce asynchronous complication. + `SO_RCVTIMEO` is well supported on the test bench. + +#### `Layer` struct + +A large part of packetimpact tests is creating packets to send and comparing +received packets against expectations. To keep tests concise, it is useful to be +able to specify just the important parts of packets that need to be set. For +example, sending a packet with default values except for TCP Flags. And for +packets received, it's useful to be able to compare just the necessary parts of +received packets and ignore the rest. + +To aid in both of those, Go structs with optional fields are created for each +encapsulation type, such as IPv4, TCP, and Ethernet. This is inspired by +[scapy](https://scapy.readthedocs.io/en/latest/). For example, here is the +struct for Ethernet: + +```go +type Ether struct { + LayerBase + SrcAddr *tcpip.LinkAddress + DstAddr *tcpip.LinkAddress + Type *tcpip.NetworkProtocolNumber +} +``` + +Each struct has the same fields as those in the +[gVisor headers](https://github.com/google/gvisor/tree/master/pkg/tcpip/header) +but with a pointer for each field that may be `nil`. + +##### Alternatives considered + +* Just use []byte like gVisor headers do. The drawback is that it makes the + tests more verbose. + * For example, there would be no way to call `Send(myBytes)` concisely and + indicate if the checksum should be calculated automatically versus + overridden. The only way would be to add lines to the test to calculate + it before each Send, which is wordy. Or make multiple versions of Send: + one that checksums IP, one that doesn't, one that checksums TCP, one + that does both, etc. That would be many combinations. + * Filtering inputs would become verbose. Either: + * large conditionals that need to be repeated many places: + `h[FlagOffset] == SYN && h[LengthOffset:LengthOffset+2] == ...` or + * Many functions, one per field, like: `filterByFlag(myBytes, SYN)`, + `filterByLength(myBytes, 20)`, `filterByNextProto(myBytes, 0x8000)`, + etc. + * Using pointers allows us to combine `Layer`s with a one-line call to + `mergo.Merge(...)`. So the default `Layers` can be overridden by a + `Layers` with just the TCP conection's src/dst which can be overridden + by one with just a test specific TCP window size. Each override is + specified as just one call to `mergo.Merge`. + * It's a proven way to separate the details of a packet from the byte + format as shown by scapy's success. +* Use packetgo. It's more general than parsing packets with gVisor. However: + * packetgo doesn't have optional fields so many of the above problems + still apply. + * It would be yet another dependency. + * It's not as well known to engineers that are already writing gVisor + code. + * It might be a good candidate for replacing the parsing of packets into + `Layer`s if all that parsing turns out to be more work than parsing by + packetgo and converting *that* to `Layer`. packetgo has easier to use + getters for the layers. This could be done later in a way that doesn't + break tests. + +#### `Layer` methods + +The `Layer` structs provide a way to partially specify an encapsulation. They +also need methods for using those partially specified encapsulation, for example +to marshal them to bytes or compare them. For those, each encapsulation +implements the `Layer` interface: + +```go +// Layer is the interface that all encapsulations must implement. +// +// A Layer is an encapsulation in a packet, such as TCP, IPv4, IPv6, etc. A +// Layer contains all the fields of the encapsulation. Each field is a pointer +// and may be nil. +type Layer interface { + // toBytes converts the Layer into bytes. In places where the Layer's field + // isn't nil, the value that is pointed to is used. When the field is nil, a + // reasonable default for the Layer is used. For example, "64" for IPv4 TTL + // and a calculated checksum for TCP or IP. Some layers require information + // from the previous or next layers in order to compute a default, such as + // TCP's checksum or Ethernet's type, so each Layer has a doubly-linked list + // to the layer's neighbors. + toBytes() ([]byte, error) + + // match checks if the current Layer matches the provided Layer. If either + // Layer has a nil in a given field, that field is considered matching. + // Otherwise, the values pointed to by the fields must match. + match(Layer) bool + + // length in bytes of the current encapsulation + length() int + + // next gets a pointer to the encapsulated Layer. + next() Layer + + // prev gets a pointer to the Layer encapsulating this one. + prev() Layer + + // setNext sets the pointer to the encapsulated Layer. + setNext(Layer) + + // setPrev sets the pointer to the Layer encapsulating this one. + setPrev(Layer) +} +``` + +For each `Layer` there is also a parsing function. For example, this one is for +Ethernet: + +``` +func ParseEther(b []byte) (Layers, error) +``` + +The parsing function converts bytes received on the wire into a `Layer` +(actually `Layers`, see below) which has no `nil`s in it. By using +`match(Layer)` to compare against another `Layer` that *does* have `nil`s in it, +the received bytes can be partially compared. The `nil`s behave as +"don't-cares". + +##### Alternatives considered + +* Matching against `[]byte` instead of converting to `Layer` first. + * The downside is that it precludes the use of a `cmp.Equal` one-liner to + do comparisons. + * It creates confusion in the code to deal with both representations at + different times. For example, is the checksum calculated on `[]byte` or + `Layer` when sending? What about when checking received packets? + +#### `Layers` + +``` +type Layers []Layer + +func (ls *Layers) match(other Layers) bool {...} +func (ls *Layers) toBytes() ([]byte, error) {...} +``` + +`Layers` is an array of `Layer`. It represents a stack of encapsulations, such +as `Layers{Ether{},IPv4{},TCP{},Payload{}}`. It also has `toBytes()` and +`match(Layers)`, like `Layer`. The parse functions above actually return +`Layers` and not `Layer` because they know about the headers below and +sequentially call each parser on the remaining, encapsulated bytes. + +All this leads to the ability to write concise packet processing. For example: + +```go +etherType := 0x8000 +flags = uint8(header.TCPFlagSyn|header.TCPFlagAck) +toMatch := Layers{Ether{Type: ðerType}, IPv4{}, TCP{Flags: &flags}} +for { + recvBytes := sniffer.Recv(time.Second) + if recvBytes == nil { + println("Got no packet for 1 second") + } + gotPacket, err := ParseEther(recvBytes) + if err == nil && toMatch.match(gotPacket) { + println("Got a TCP/IPv4/Eth packet with SYNACK") + } +} +``` + +##### Alternatives considered + +* Don't use previous and next pointers. + * Each layer may need to be able to interrogate the layers aroung it, like + for computing the next protocol number or total length. So *some* + mechanism is needed for a `Layer` to see neighboring layers. + * We could pass the entire array `Layers` to the `toBytes()` function. + Passing an array to a method that includes in the array the function + receiver itself seems wrong. + +#### Connections + +Using `Layers` above, we can create connection structures to maintain state +about connections. For example, here is the `TCPIPv4` struct: + +``` +type TCPIPv4 struct { + outgoing Layers + incoming Layers + localSeqNum uint32 + remoteSeqNum uint32 + sniffer Sniffer + injector Injector + t *testing.T +} +``` + +`TCPIPv4` contains an `outgoing Layers` which holds the defaults for the +connection, such as the source and destination MACs, IPs, and ports. When +`outgoing.toBytes()` is called a valid packet for this TCPIPv4 flow is built. + +It also contains `incoming Layers` which holds filter for incoming packets that +belong to this flow. `incoming.match(Layers)` is used on received bytes to check +if they are part of the flow. + +The `sniffer` and `injector` are for receiving and sending raw packet bytes. The +`localSeqNum` and `remoteSeqNum` are updated by `Send` and `Recv` so that +outgoing packets will have, by default, the correct sequence number and ack +number. + +TCPIPv4 provides some functions: + +``` +func (conn *TCPIPv4) Send(tcp TCP) {...} +func (conn *TCPIPv4) Recv(timeout time.Duration) *TCP {...} +``` + +`Send(tcp TCP)` uses [mergo](https://github.com/imdario/mergo) to merge the +provided `TCP` (a `Layer`) into `outgoing`. This way the user can specify +concisely just which fields of `outgoing` to modify. The packet is sent using +the `injector`. + +`Recv(timeout time.Duration)` reads packets from the sniffer until either the +timeout has elapsed or a packet that matches `incoming` arrives. + +Using those, we can perform a TCP 3-way handshake without too much code: + +```go +func (conn *TCPIPv4) Handshake() { + syn := uint8(header.TCPFlagSyn) + synack := uint8(header.TCPFlagSyn) + ack := uint8(header.TCPFlagAck) + conn.Send(TCP{Flags: &syn}) // Send a packet with all defaults but set TCP-SYN. + + // Wait for the SYN-ACK response. + for { + newTCP := conn.Recv(time.Second) // This already filters by MAC, IP, and ports. + if TCP{Flags: &synack}.match(newTCP) { + break // Only if it's a SYN-ACK proceed. + } + } + + conn.Send(TCP{Flags: &ack}) // Send an ACK. The seq and ack numbers are set correctly. +} +``` + +The handshake code is part of the testbench utilities so tests can share this +common sequence, making tests even more concise. + +##### Alternatives considered + +* Instead of storing `outgoing` and `incoming`, store values. + * There would be many more things to store instead, like `localMac`, + `remoteMac`, `localIP`, `remoteIP`, `localPort`, and `remotePort`. + * Construction of a packet would be many lines to copy each of these + values into a `[]byte`. And there would be slight variations needed for + each encapsulation stack, like TCPIPv6 and ARP. + * Filtering incoming packets would be a long sequence: + * Compare the MACs, then + * Parse the next header, then + * Compare the IPs, then + * Parse the next header, then + * Compare the TCP ports. Instead it's all just one call to + `cmp.Equal(...)`, for all sequences. + * A TCPIPv6 connection could share most of the code. Only the type of the + IP addresses are different. The types of `outgoing` and `incoming` would + be remain `Layers`. + * An ARP connection could share all the Ethernet parts. The IP `Layer` + could be factored out of `outgoing`. After that, the IPv4 and IPv6 + connections could implement one interface and a single TCP struct could + have either network protocol through composition. + +## Putting it all together + +Here's what te start of a packetimpact unit test looks like. This test creates a +TCP connection with the DUT. There are added comments for explanation in this +document but a real test might not include them in order to stay even more +concise. + +```go +func TestMyTcpTest(t *testing.T) { + // Prepare a DUT for communication. + dut := testbench.NewDUT(t) + + // This does: + // dut.Socket() + // dut.Bind() + // dut.Getsockname() to learn the new port number + // dut.Listen() + listenFD, remotePort := dut.CreateListener(unix.SOCK_STREAM, unix.IPPROTO_TCP, 1) + defer dut.Close(listenFD) // Tell the DUT to close the socket at the end of the test. + + // Monitor a new TCP connection with sniffer, injector, sequence number tracking, + // and reasonable outgoing and incoming packet field default IPs, MACs, and port numbers. + conn := testbench.NewTCPIPv4(t, dut, remotePort) + + // Perform a 3-way handshake: send SYN, expect SYNACK, send ACK. + conn.Handshake() + + // Tell the DUT to accept the new connection. + acceptFD := dut.Accept(acceptFd) +} +``` + +## Other notes + +* The time between receiving a SYN-ACK and replying with an ACK in `Handshake` + is about 3ms. This is much slower than the native unix response, which is + about 0.3ms. Packetdrill gets closer to 0.3ms. For tests where timing is + crucial, packetdrill is faster and more precise. diff --git a/test/packetimpact/dut/BUILD b/test/packetimpact/dut/BUILD new file mode 100644 index 000000000..3ce63c2c6 --- /dev/null +++ b/test/packetimpact/dut/BUILD @@ -0,0 +1,18 @@ +load("//tools:defs.bzl", "cc_binary", "grpcpp") + +package( + default_visibility = ["//test/packetimpact:__subpackages__"], + licenses = ["notice"], +) + +cc_binary( + name = "posix_server", + srcs = ["posix_server.cc"], + linkstatic = 1, + static = True, # This is needed for running in a docker container. + deps = [ + grpcpp, + "//test/packetimpact/proto:posix_server_cc_grpc_proto", + "//test/packetimpact/proto:posix_server_cc_proto", + ], +) diff --git a/test/packetimpact/dut/posix_server.cc b/test/packetimpact/dut/posix_server.cc new file mode 100644 index 000000000..2f10dda40 --- /dev/null +++ b/test/packetimpact/dut/posix_server.cc @@ -0,0 +1,229 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at // +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#include <fcntl.h> +#include <getopt.h> +#include <netdb.h> +#include <netinet/in.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/socket.h> +#include <sys/types.h> +#include <unistd.h> + +#include <iostream> +#include <unordered_map> + +#include "arpa/inet.h" +#include "include/grpcpp/security/server_credentials.h" +#include "include/grpcpp/server_builder.h" +#include "test/packetimpact/proto/posix_server.grpc.pb.h" +#include "test/packetimpact/proto/posix_server.pb.h" + +// Converts a sockaddr_storage to a Sockaddr message. +::grpc::Status sockaddr_to_proto(const sockaddr_storage &addr, + socklen_t addrlen, + posix_server::Sockaddr *sockaddr_proto) { + switch (addr.ss_family) { + case AF_INET: { + auto addr_in = reinterpret_cast<const sockaddr_in *>(&addr); + auto response_in = sockaddr_proto->mutable_in(); + response_in->set_family(addr_in->sin_family); + response_in->set_port(ntohs(addr_in->sin_port)); + response_in->mutable_addr()->assign( + reinterpret_cast<const char *>(&addr_in->sin_addr.s_addr), 4); + return ::grpc::Status::OK; + } + case AF_INET6: { + auto addr_in6 = reinterpret_cast<const sockaddr_in6 *>(&addr); + auto response_in6 = sockaddr_proto->mutable_in6(); + response_in6->set_family(addr_in6->sin6_family); + response_in6->set_port(ntohs(addr_in6->sin6_port)); + response_in6->set_flowinfo(ntohl(addr_in6->sin6_flowinfo)); + response_in6->mutable_addr()->assign( + reinterpret_cast<const char *>(&addr_in6->sin6_addr.s6_addr), 16); + response_in6->set_scope_id(ntohl(addr_in6->sin6_scope_id)); + return ::grpc::Status::OK; + } + } + return ::grpc::Status(grpc::StatusCode::INVALID_ARGUMENT, "Unknown Sockaddr"); +} + +class PosixImpl final : public posix_server::Posix::Service { + ::grpc::Status Socket(grpc_impl::ServerContext *context, + const ::posix_server::SocketRequest *request, + ::posix_server::SocketResponse *response) override { + response->set_fd( + socket(request->domain(), request->type(), request->protocol())); + response->set_errno_(errno); + return ::grpc::Status::OK; + } + + ::grpc::Status Bind(grpc_impl::ServerContext *context, + const ::posix_server::BindRequest *request, + ::posix_server::BindResponse *response) override { + if (!request->has_addr()) { + return ::grpc::Status(grpc::StatusCode::INVALID_ARGUMENT, + "Missing address"); + } + sockaddr_storage addr; + + switch (request->addr().sockaddr_case()) { + case posix_server::Sockaddr::SockaddrCase::kIn: { + auto request_in = request->addr().in(); + if (request_in.addr().size() != 4) { + return ::grpc::Status(grpc::StatusCode::INVALID_ARGUMENT, + "IPv4 address must be 4 bytes"); + } + auto addr_in = reinterpret_cast<sockaddr_in *>(&addr); + addr_in->sin_family = request_in.family(); + addr_in->sin_port = htons(request_in.port()); + request_in.addr().copy( + reinterpret_cast<char *>(&addr_in->sin_addr.s_addr), 4); + break; + } + case posix_server::Sockaddr::SockaddrCase::kIn6: { + auto request_in6 = request->addr().in6(); + if (request_in6.addr().size() != 16) { + return ::grpc::Status(grpc::StatusCode::INVALID_ARGUMENT, + "IPv6 address must be 16 bytes"); + } + auto addr_in6 = reinterpret_cast<sockaddr_in6 *>(&addr); + addr_in6->sin6_family = request_in6.family(); + addr_in6->sin6_port = htons(request_in6.port()); + addr_in6->sin6_flowinfo = htonl(request_in6.flowinfo()); + request_in6.addr().copy( + reinterpret_cast<char *>(&addr_in6->sin6_addr.s6_addr), 16); + addr_in6->sin6_scope_id = htonl(request_in6.scope_id()); + break; + } + case posix_server::Sockaddr::SockaddrCase::SOCKADDR_NOT_SET: + default: + return ::grpc::Status(grpc::StatusCode::INVALID_ARGUMENT, + "Unknown Sockaddr"); + } + response->set_ret(bind(request->sockfd(), + reinterpret_cast<sockaddr *>(&addr), sizeof(addr))); + response->set_errno_(errno); + return ::grpc::Status::OK; + } + + ::grpc::Status GetSockName( + grpc_impl::ServerContext *context, + const ::posix_server::GetSockNameRequest *request, + ::posix_server::GetSockNameResponse *response) override { + sockaddr_storage addr; + socklen_t addrlen = sizeof(addr); + response->set_ret(getsockname( + request->sockfd(), reinterpret_cast<sockaddr *>(&addr), &addrlen)); + response->set_errno_(errno); + return sockaddr_to_proto(addr, addrlen, response->mutable_addr()); + } + + ::grpc::Status Listen(grpc_impl::ServerContext *context, + const ::posix_server::ListenRequest *request, + ::posix_server::ListenResponse *response) override { + response->set_ret(listen(request->sockfd(), request->backlog())); + response->set_errno_(errno); + return ::grpc::Status::OK; + } + + ::grpc::Status Accept(grpc_impl::ServerContext *context, + const ::posix_server::AcceptRequest *request, + ::posix_server::AcceptResponse *response) override { + sockaddr_storage addr; + socklen_t addrlen = sizeof(addr); + response->set_fd(accept(request->sockfd(), + reinterpret_cast<sockaddr *>(&addr), &addrlen)); + response->set_errno_(errno); + return sockaddr_to_proto(addr, addrlen, response->mutable_addr()); + } + + ::grpc::Status SetSockOpt( + grpc_impl::ServerContext *context, + const ::posix_server::SetSockOptRequest *request, + ::posix_server::SetSockOptResponse *response) override { + response->set_ret(setsockopt(request->sockfd(), request->level(), + request->optname(), request->optval().c_str(), + request->optval().size())); + response->set_errno_(errno); + return ::grpc::Status::OK; + } + + ::grpc::Status SetSockOptTimeval( + ::grpc::ServerContext *context, + const ::posix_server::SetSockOptTimevalRequest *request, + ::posix_server::SetSockOptTimevalResponse *response) override { + timeval tv = {.tv_sec = static_cast<__time_t>(request->timeval().seconds()), + .tv_usec = static_cast<__suseconds_t>( + request->timeval().microseconds())}; + response->set_ret(setsockopt(request->sockfd(), request->level(), + request->optname(), &tv, sizeof(tv))); + response->set_errno_(errno); + return ::grpc::Status::OK; + } + + ::grpc::Status Close(grpc_impl::ServerContext *context, + const ::posix_server::CloseRequest *request, + ::posix_server::CloseResponse *response) override { + response->set_ret(close(request->fd())); + response->set_errno_(errno); + return ::grpc::Status::OK; + } +}; + +// Parse command line options. Returns a pointer to the first argument beyond +// the options. +void parse_command_line_options(int argc, char *argv[], std::string *ip, + int *port) { + static struct option options[] = {{"ip", required_argument, NULL, 1}, + {"port", required_argument, NULL, 2}, + {0, 0, 0, 0}}; + + // Parse the arguments. + int c; + while ((c = getopt_long(argc, argv, "", options, NULL)) > 0) { + if (c == 1) { + *ip = optarg; + } else if (c == 2) { + *port = std::stoi(std::string(optarg)); + } + } +} + +void run_server(const std::string &ip, int port) { + PosixImpl posix_service; + grpc::ServerBuilder builder; + std::string server_address = ip + ":" + std::to_string(port); + // Set the authentication mechanism. + std::shared_ptr<grpc::ServerCredentials> creds = + grpc::InsecureServerCredentials(); + builder.AddListeningPort(server_address, creds); + builder.RegisterService(&posix_service); + + std::unique_ptr<grpc::Server> server(builder.BuildAndStart()); + std::cerr << "Server listening on " << server_address << std::endl; + server->Wait(); + std::cerr << "posix_server is finished." << std::endl; +} + +int main(int argc, char *argv[]) { + std::cerr << "posix_server is starting." << std::endl; + std::string ip; + int port; + parse_command_line_options(argc, argv, &ip, &port); + + std::cerr << "Got IP " << ip << " and port " << port << "." << std::endl; + run_server(ip, port); +} diff --git a/test/packetimpact/proto/BUILD b/test/packetimpact/proto/BUILD new file mode 100644 index 000000000..4a4370f42 --- /dev/null +++ b/test/packetimpact/proto/BUILD @@ -0,0 +1,12 @@ +load("//tools:defs.bzl", "proto_library") + +package( + default_visibility = ["//test/packetimpact:__subpackages__"], + licenses = ["notice"], +) + +proto_library( + name = "posix_server", + srcs = ["posix_server.proto"], + has_services = 1, +) diff --git a/test/packetimpact/proto/posix_server.proto b/test/packetimpact/proto/posix_server.proto new file mode 100644 index 000000000..026876fc2 --- /dev/null +++ b/test/packetimpact/proto/posix_server.proto @@ -0,0 +1,150 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +syntax = "proto3"; + +package posix_server; + +message SocketRequest { + int32 domain = 1; + int32 type = 2; + int32 protocol = 3; +} + +message SocketResponse { + int32 fd = 1; + int32 errno_ = 2; +} + +message SockaddrIn { + int32 family = 1; + uint32 port = 2; + bytes addr = 3; +} + +message SockaddrIn6 { + uint32 family = 1; + uint32 port = 2; + uint32 flowinfo = 3; + bytes addr = 4; + uint32 scope_id = 5; +} + +message Sockaddr { + oneof sockaddr { + SockaddrIn in = 1; + SockaddrIn6 in6 = 2; + } +} + +message BindRequest { + int32 sockfd = 1; + Sockaddr addr = 2; +} + +message BindResponse { + int32 ret = 1; + int32 errno_ = 2; +} + +message GetSockNameRequest { + int32 sockfd = 1; +} + +message GetSockNameResponse { + int32 ret = 1; + int32 errno_ = 2; + Sockaddr addr = 3; +} + +message ListenRequest { + int32 sockfd = 1; + int32 backlog = 2; +} + +message ListenResponse { + int32 ret = 1; + int32 errno_ = 2; +} + +message AcceptRequest { + int32 sockfd = 1; +} + +message AcceptResponse { + int32 fd = 1; + int32 errno_ = 2; + Sockaddr addr = 3; +} + +message SetSockOptRequest { + int32 sockfd = 1; + int32 level = 2; + int32 optname = 3; + bytes optval = 4; +} + +message SetSockOptResponse { + int32 ret = 1; + int32 errno_ = 2; +} + +message Timeval { + int64 seconds = 1; + int64 microseconds = 2; +} + +message SetSockOptTimevalRequest { + int32 sockfd = 1; + int32 level = 2; + int32 optname = 3; + Timeval timeval = 4; +} + +message SetSockOptTimevalResponse { + int32 ret = 1; + int32 errno_ = 2; +} + +message CloseRequest { + int32 fd = 1; +} + +message CloseResponse { + int32 ret = 1; + int32 errno_ = 2; +} + +service Posix { + // Call socket() on the DUT. + rpc Socket(SocketRequest) returns (SocketResponse); + // Call bind() on the DUT. + rpc Bind(BindRequest) returns (BindResponse); + // Call getsockname() on the DUT. + rpc GetSockName(GetSockNameRequest) returns (GetSockNameResponse); + // Call listen() on the DUT. + rpc Listen(ListenRequest) returns (ListenResponse); + // Call accept() on the DUT. + rpc Accept(AcceptRequest) returns (AcceptResponse); + // Call setsockopt() on the DUT. You should prefer one of the other + // SetSockOpt* functions with a more structured optval or else you may get the + // encoding wrong, such as making a bad assumption about the server's word + // sizes or endianness. + rpc SetSockOpt(SetSockOptRequest) returns (SetSockOptResponse); + // Call setsockopt() on the DUT with a Timeval optval. + rpc SetSockOptTimeval(SetSockOptTimevalRequest) + returns (SetSockOptTimevalResponse); + // Call close() on the DUT. + rpc Close(CloseRequest) returns (CloseResponse); +} diff --git a/test/packetimpact/testbench/BUILD b/test/packetimpact/testbench/BUILD new file mode 100644 index 000000000..a34c81fcc --- /dev/null +++ b/test/packetimpact/testbench/BUILD @@ -0,0 +1,31 @@ +load("//tools:defs.bzl", "go_library") + +package( + default_visibility = ["//test/packetimpact:__subpackages__"], + licenses = ["notice"], +) + +go_library( + name = "testbench", + srcs = [ + "connections.go", + "dut.go", + "dut_client.go", + "layers.go", + "rawsockets.go", + ], + deps = [ + "//pkg/tcpip", + "//pkg/tcpip/header", + "//pkg/tcpip/seqnum", + "//pkg/usermem", + "//test/packetimpact/proto:posix_server_go_proto", + "@com_github_google_go-cmp//cmp:go_default_library", + "@com_github_google_go-cmp//cmp/cmpopts:go_default_library", + "@com_github_imdario_mergo//:go_default_library", + "@com_github_mohae_deepcopy//:go_default_library", + "@org_golang_google_grpc//:go_default_library", + "@org_golang_google_grpc//keepalive:go_default_library", + "@org_golang_x_sys//unix:go_default_library", + ], +) diff --git a/test/packetimpact/testbench/connections.go b/test/packetimpact/testbench/connections.go new file mode 100644 index 000000000..b7aa63934 --- /dev/null +++ b/test/packetimpact/testbench/connections.go @@ -0,0 +1,245 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// Package testbench has utilities to send and receive packets and also command +// the DUT to run POSIX functions. +package testbench + +import ( + "flag" + "fmt" + "math/rand" + "net" + "testing" + "time" + + "github.com/mohae/deepcopy" + "golang.org/x/sys/unix" + "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/tcpip/header" + "gvisor.dev/gvisor/pkg/tcpip/seqnum" +) + +var localIPv4 = flag.String("local_ipv4", "", "local IPv4 address for test packets") +var remoteIPv4 = flag.String("remote_ipv4", "", "remote IPv4 address for test packets") +var localMAC = flag.String("local_mac", "", "local mac address for test packets") +var remoteMAC = flag.String("remote_mac", "", "remote mac address for test packets") + +// TCPIPv4 maintains state about a TCP/IPv4 connection. +type TCPIPv4 struct { + outgoing Layers + incoming Layers + LocalSeqNum seqnum.Value + RemoteSeqNum seqnum.Value + SynAck *TCP + sniffer Sniffer + injector Injector + portPickerFD int + t *testing.T +} + +// pickPort makes a new socket and returns the socket FD and port. The caller +// must close the FD when done with the port if there is no error. +func pickPort() (int, uint16, error) { + fd, err := unix.Socket(unix.AF_INET, unix.SOCK_STREAM, 0) + if err != nil { + return -1, 0, err + } + var sa unix.SockaddrInet4 + copy(sa.Addr[0:4], net.ParseIP(*localIPv4).To4()) + if err := unix.Bind(fd, &sa); err != nil { + unix.Close(fd) + return -1, 0, err + } + newSockAddr, err := unix.Getsockname(fd) + if err != nil { + unix.Close(fd) + return -1, 0, err + } + newSockAddrInet4, ok := newSockAddr.(*unix.SockaddrInet4) + if !ok { + unix.Close(fd) + return -1, 0, fmt.Errorf("can't cast Getsockname result to SockaddrInet4") + } + return fd, uint16(newSockAddrInet4.Port), nil +} + +// tcpLayerIndex is the position of the TCP layer in the TCPIPv4 connection. It +// is the third, after Ethernet and IPv4. +const tcpLayerIndex int = 2 + +// NewTCPIPv4 creates a new TCPIPv4 connection with reasonable defaults. +func NewTCPIPv4(t *testing.T, dut DUT, outgoingTCP, incomingTCP TCP) TCPIPv4 { + lMAC, err := tcpip.ParseMACAddress(*localMAC) + if err != nil { + t.Fatalf("can't parse localMAC %q: %s", *localMAC, err) + } + + rMAC, err := tcpip.ParseMACAddress(*remoteMAC) + if err != nil { + t.Fatalf("can't parse remoteMAC %q: %s", *remoteMAC, err) + } + + portPickerFD, localPort, err := pickPort() + if err != nil { + t.Fatalf("can't pick a port: %s", err) + } + lIP := tcpip.Address(net.ParseIP(*localIPv4).To4()) + rIP := tcpip.Address(net.ParseIP(*remoteIPv4).To4()) + + sniffer, err := NewSniffer(t) + if err != nil { + t.Fatalf("can't make new sniffer: %s", err) + } + + injector, err := NewInjector(t) + if err != nil { + t.Fatalf("can't make new injector: %s", err) + } + + newOutgoingTCP := &TCP{ + DataOffset: Uint8(header.TCPMinimumSize), + WindowSize: Uint16(32768), + SrcPort: &localPort, + } + if err := newOutgoingTCP.merge(outgoingTCP); err != nil { + t.Fatalf("can't merge %v into %v: %s", outgoingTCP, newOutgoingTCP, err) + } + newIncomingTCP := &TCP{ + DstPort: &localPort, + } + if err := newIncomingTCP.merge(incomingTCP); err != nil { + t.Fatalf("can't merge %v into %v: %s", incomingTCP, newIncomingTCP, err) + } + return TCPIPv4{ + outgoing: Layers{ + &Ether{SrcAddr: &lMAC, DstAddr: &rMAC}, + &IPv4{SrcAddr: &lIP, DstAddr: &rIP}, + newOutgoingTCP}, + incoming: Layers{ + &Ether{SrcAddr: &rMAC, DstAddr: &lMAC}, + &IPv4{SrcAddr: &rIP, DstAddr: &lIP}, + newIncomingTCP}, + sniffer: sniffer, + injector: injector, + portPickerFD: portPickerFD, + t: t, + LocalSeqNum: seqnum.Value(rand.Uint32()), + } +} + +// Close the injector and sniffer associated with this connection. +func (conn *TCPIPv4) Close() { + conn.sniffer.Close() + conn.injector.Close() + if err := unix.Close(conn.portPickerFD); err != nil { + conn.t.Fatalf("can't close portPickerFD: %s", err) + } + conn.portPickerFD = -1 +} + +// Send a packet with reasonable defaults and override some fields by tcp. +func (conn *TCPIPv4) Send(tcp TCP, additionalLayers ...Layer) { + if tcp.SeqNum == nil { + tcp.SeqNum = Uint32(uint32(conn.LocalSeqNum)) + } + if tcp.AckNum == nil { + tcp.AckNum = Uint32(uint32(conn.RemoteSeqNum)) + } + layersToSend := deepcopy.Copy(conn.outgoing).(Layers) + if err := layersToSend[tcpLayerIndex].(*TCP).merge(tcp); err != nil { + conn.t.Fatalf("can't merge %v into %v: %s", tcp, layersToSend[tcpLayerIndex], err) + } + layersToSend = append(layersToSend, additionalLayers...) + outBytes, err := layersToSend.toBytes() + if err != nil { + conn.t.Fatalf("can't build outgoing TCP packet: %s", err) + } + conn.injector.Send(outBytes) + + // Compute the next TCP sequence number. + for i := tcpLayerIndex + 1; i < len(layersToSend); i++ { + conn.LocalSeqNum.UpdateForward(seqnum.Size(layersToSend[i].length())) + } + if tcp.Flags != nil && *tcp.Flags&(header.TCPFlagSyn|header.TCPFlagFin) != 0 { + conn.LocalSeqNum.UpdateForward(1) + } +} + +// Recv gets a packet from the sniffer within the timeout provided. If no packet +// arrives before the timeout, it returns nil. +func (conn *TCPIPv4) Recv(timeout time.Duration) *TCP { + deadline := time.Now().Add(timeout) + for { + timeout = deadline.Sub(time.Now()) + if timeout <= 0 { + break + } + b := conn.sniffer.Recv(timeout) + if b == nil { + break + } + layers, err := ParseEther(b) + if err != nil { + continue // Ignore packets that can't be parsed. + } + if !conn.incoming.match(layers) { + continue // Ignore packets that don't match the expected incoming. + } + tcpHeader := (layers[tcpLayerIndex]).(*TCP) + conn.RemoteSeqNum = seqnum.Value(*tcpHeader.SeqNum) + if *tcpHeader.Flags&(header.TCPFlagSyn|header.TCPFlagFin) != 0 { + conn.RemoteSeqNum.UpdateForward(1) + } + for i := tcpLayerIndex + 1; i < len(layers); i++ { + conn.RemoteSeqNum.UpdateForward(seqnum.Size(layers[i].length())) + } + return tcpHeader + } + return nil +} + +// Expect a packet that matches the provided tcp within the timeout specified. +// If it doesn't arrive in time, the test fails. +func (conn *TCPIPv4) Expect(tcp TCP, timeout time.Duration) *TCP { + deadline := time.Now().Add(timeout) + for { + timeout = deadline.Sub(time.Now()) + if timeout <= 0 { + return nil + } + gotTCP := conn.Recv(timeout) + if gotTCP == nil { + return nil + } + if tcp.match(gotTCP) { + return gotTCP + } + } +} + +// Handshake performs a TCP 3-way handshake. +func (conn *TCPIPv4) Handshake() { + // Send the SYN. + conn.Send(TCP{Flags: Uint8(header.TCPFlagSyn)}) + + // Wait for the SYN-ACK. + conn.SynAck = conn.Expect(TCP{Flags: Uint8(header.TCPFlagSyn | header.TCPFlagAck)}, time.Second) + if conn.SynAck == nil { + conn.t.Fatalf("didn't get synack during handshake") + } + + // Send an ACK. + conn.Send(TCP{Flags: Uint8(header.TCPFlagAck)}) +} diff --git a/test/packetimpact/testbench/dut.go b/test/packetimpact/testbench/dut.go new file mode 100644 index 000000000..8ea1706d3 --- /dev/null +++ b/test/packetimpact/testbench/dut.go @@ -0,0 +1,363 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package testbench + +import ( + "context" + "flag" + "net" + "strconv" + "syscall" + "testing" + "time" + + pb "gvisor.dev/gvisor/test/packetimpact/proto/posix_server_go_proto" + + "golang.org/x/sys/unix" + "google.golang.org/grpc" + "google.golang.org/grpc/keepalive" +) + +var ( + posixServerIP = flag.String("posix_server_ip", "", "ip address to listen to for UDP commands") + posixServerPort = flag.Int("posix_server_port", 40000, "port to listen to for UDP commands") + rpcTimeout = flag.Duration("rpc_timeout", 100*time.Millisecond, "gRPC timeout") + rpcKeepalive = flag.Duration("rpc_keepalive", 10*time.Second, "gRPC keepalive") +) + +// DUT communicates with the DUT to force it to make POSIX calls. +type DUT struct { + t *testing.T + conn *grpc.ClientConn + posixServer PosixClient +} + +// NewDUT creates a new connection with the DUT over gRPC. +func NewDUT(t *testing.T) DUT { + flag.Parse() + posixServerAddress := *posixServerIP + ":" + strconv.Itoa(*posixServerPort) + conn, err := grpc.Dial(posixServerAddress, grpc.WithInsecure(), grpc.WithKeepaliveParams(keepalive.ClientParameters{Timeout: *rpcKeepalive})) + if err != nil { + t.Fatalf("failed to grpc.Dial(%s): %s", posixServerAddress, err) + } + posixServer := NewPosixClient(conn) + return DUT{ + t: t, + conn: conn, + posixServer: posixServer, + } +} + +// TearDown closes the underlying connection. +func (dut *DUT) TearDown() { + dut.conn.Close() +} + +// SocketWithErrno calls socket on the DUT and returns the fd and errno. +func (dut *DUT) SocketWithErrno(domain, typ, proto int32) (int32, error) { + dut.t.Helper() + req := pb.SocketRequest{ + Domain: domain, + Type: typ, + Protocol: proto, + } + ctx := context.Background() + resp, err := dut.posixServer.Socket(ctx, &req) + if err != nil { + dut.t.Fatalf("failed to call Socket: %s", err) + } + return resp.GetFd(), syscall.Errno(resp.GetErrno_()) +} + +// Socket calls socket on the DUT and returns the file descriptor. If socket +// fails on the DUT, the test ends. +func (dut *DUT) Socket(domain, typ, proto int32) int32 { + dut.t.Helper() + fd, err := dut.SocketWithErrno(domain, typ, proto) + if fd < 0 { + dut.t.Fatalf("failed to create socket: %s", err) + } + return fd +} + +func (dut *DUT) sockaddrToProto(sa unix.Sockaddr) *pb.Sockaddr { + dut.t.Helper() + switch s := sa.(type) { + case *unix.SockaddrInet4: + return &pb.Sockaddr{ + Sockaddr: &pb.Sockaddr_In{ + In: &pb.SockaddrIn{ + Family: unix.AF_INET, + Port: uint32(s.Port), + Addr: s.Addr[:], + }, + }, + } + case *unix.SockaddrInet6: + return &pb.Sockaddr{ + Sockaddr: &pb.Sockaddr_In6{ + In6: &pb.SockaddrIn6{ + Family: unix.AF_INET6, + Port: uint32(s.Port), + Flowinfo: 0, + ScopeId: s.ZoneId, + Addr: s.Addr[:], + }, + }, + } + } + dut.t.Fatalf("can't parse Sockaddr: %+v", sa) + return nil +} + +func (dut *DUT) protoToSockaddr(sa *pb.Sockaddr) unix.Sockaddr { + dut.t.Helper() + switch s := sa.Sockaddr.(type) { + case *pb.Sockaddr_In: + ret := unix.SockaddrInet4{ + Port: int(s.In.GetPort()), + } + copy(ret.Addr[:], s.In.GetAddr()) + return &ret + case *pb.Sockaddr_In6: + ret := unix.SockaddrInet6{ + Port: int(s.In6.GetPort()), + ZoneId: s.In6.GetScopeId(), + } + copy(ret.Addr[:], s.In6.GetAddr()) + } + dut.t.Fatalf("can't parse Sockaddr: %+v", sa) + return nil +} + +// BindWithErrno calls bind on the DUT. +func (dut *DUT) BindWithErrno(fd int32, sa unix.Sockaddr) (int32, error) { + dut.t.Helper() + req := pb.BindRequest{ + Sockfd: fd, + Addr: dut.sockaddrToProto(sa), + } + ctx := context.Background() + resp, err := dut.posixServer.Bind(ctx, &req) + if err != nil { + dut.t.Fatalf("failed to call Bind: %s", err) + } + return resp.GetRet(), syscall.Errno(resp.GetErrno_()) +} + +// Bind calls bind on the DUT and causes a fatal test failure if it doesn't +// succeed. +func (dut *DUT) Bind(fd int32, sa unix.Sockaddr) { + dut.t.Helper() + ret, err := dut.BindWithErrno(fd, sa) + if ret != 0 { + dut.t.Fatalf("failed to bind socket: %s", err) + } +} + +// GetSockNameWithErrno calls getsockname on the DUT. +func (dut *DUT) GetSockNameWithErrno(sockfd int32) (int32, unix.Sockaddr, error) { + dut.t.Helper() + req := pb.GetSockNameRequest{ + Sockfd: sockfd, + } + ctx := context.Background() + resp, err := dut.posixServer.GetSockName(ctx, &req) + if err != nil { + dut.t.Fatalf("failed to call Bind: %s", err) + } + return resp.GetRet(), dut.protoToSockaddr(resp.GetAddr()), syscall.Errno(resp.GetErrno_()) +} + +// GetSockName calls getsockname on the DUT and causes a fatal test failure if +// it doens't succeed. +func (dut *DUT) GetSockName(sockfd int32) unix.Sockaddr { + dut.t.Helper() + ret, sa, err := dut.GetSockNameWithErrno(sockfd) + if ret != 0 { + dut.t.Fatalf("failed to getsockname: %s", err) + } + return sa +} + +// ListenWithErrno calls listen on the DUT. +func (dut *DUT) ListenWithErrno(sockfd, backlog int32) (int32, error) { + dut.t.Helper() + req := pb.ListenRequest{ + Sockfd: sockfd, + Backlog: backlog, + } + ctx, cancel := context.WithTimeout(context.Background(), *rpcTimeout) + defer cancel() + resp, err := dut.posixServer.Listen(ctx, &req) + if err != nil { + dut.t.Fatalf("failed to call Listen: %s", err) + } + return resp.GetRet(), syscall.Errno(resp.GetErrno_()) +} + +// Listen calls listen on the DUT and causes a fatal test failure if it doesn't +// succeed. +func (dut *DUT) Listen(sockfd, backlog int32) { + dut.t.Helper() + ret, err := dut.ListenWithErrno(sockfd, backlog) + if ret != 0 { + dut.t.Fatalf("failed to listen: %s", err) + } +} + +// AcceptWithErrno calls accept on the DUT. +func (dut *DUT) AcceptWithErrno(sockfd int32) (int32, unix.Sockaddr, error) { + dut.t.Helper() + req := pb.AcceptRequest{ + Sockfd: sockfd, + } + ctx, cancel := context.WithTimeout(context.Background(), *rpcTimeout) + defer cancel() + resp, err := dut.posixServer.Accept(ctx, &req) + if err != nil { + dut.t.Fatalf("failed to call Accept: %s", err) + } + return resp.GetFd(), dut.protoToSockaddr(resp.GetAddr()), syscall.Errno(resp.GetErrno_()) +} + +// Accept calls accept on the DUT and causes a fatal test failure if it doesn't +// succeed. +func (dut *DUT) Accept(sockfd int32) (int32, unix.Sockaddr) { + dut.t.Helper() + fd, sa, err := dut.AcceptWithErrno(sockfd) + if fd < 0 { + dut.t.Fatalf("failed to accept: %s", err) + } + return fd, sa +} + +// SetSockOptWithErrno calls setsockopt on the DUT. +func (dut *DUT) SetSockOptWithErrno(sockfd, level, optname int32, optval []byte) (int32, error) { + dut.t.Helper() + req := pb.SetSockOptRequest{ + Sockfd: sockfd, + Level: level, + Optname: optname, + Optval: optval, + } + ctx, cancel := context.WithTimeout(context.Background(), *rpcTimeout) + defer cancel() + resp, err := dut.posixServer.SetSockOpt(ctx, &req) + if err != nil { + dut.t.Fatalf("failed to call SetSockOpt: %s", err) + } + return resp.GetRet(), syscall.Errno(resp.GetErrno_()) +} + +// SetSockOpt calls setsockopt on the DUT and causes a fatal test failure if it +// doesn't succeed. +func (dut *DUT) SetSockOpt(sockfd, level, optname int32, optval []byte) { + dut.t.Helper() + ret, err := dut.SetSockOptWithErrno(sockfd, level, optname, optval) + if ret != 0 { + dut.t.Fatalf("failed to SetSockOpt: %s", err) + } +} + +// SetSockOptTimevalWithErrno calls setsockopt with the timeval converted to +// bytes. +func (dut *DUT) SetSockOptTimevalWithErrno(sockfd, level, optname int32, tv *unix.Timeval) (int32, error) { + dut.t.Helper() + timeval := pb.Timeval{ + Seconds: int64(tv.Sec), + Microseconds: int64(tv.Usec), + } + req := pb.SetSockOptTimevalRequest{ + Sockfd: sockfd, + Level: level, + Optname: optname, + Timeval: &timeval, + } + ctx, cancel := context.WithTimeout(context.Background(), *rpcTimeout) + defer cancel() + resp, err := dut.posixServer.SetSockOptTimeval(ctx, &req) + if err != nil { + dut.t.Fatalf("failed to call SetSockOptTimeval: %s", err) + } + return resp.GetRet(), syscall.Errno(resp.GetErrno_()) +} + +// SetSockOptTimeval calls setsockopt on the DUT and causes a fatal test failure +// if it doesn't succeed. +func (dut *DUT) SetSockOptTimeval(sockfd, level, optname int32, tv *unix.Timeval) { + dut.t.Helper() + ret, err := dut.SetSockOptTimevalWithErrno(sockfd, level, optname, tv) + if ret != 0 { + dut.t.Fatalf("failed to SetSockOptTimeval: %s", err) + } +} + +// CloseWithErrno calls close on the DUT. +func (dut *DUT) CloseWithErrno(fd int32) (int32, error) { + dut.t.Helper() + req := pb.CloseRequest{ + Fd: fd, + } + ctx, cancel := context.WithTimeout(context.Background(), *rpcTimeout) + defer cancel() + resp, err := dut.posixServer.Close(ctx, &req) + if err != nil { + dut.t.Fatalf("failed to call Close: %s", err) + } + return resp.GetRet(), syscall.Errno(resp.GetErrno_()) +} + +// Close calls close on the DUT and causes a fatal test failure if it doesn't +// succeed. +func (dut *DUT) Close(fd int32) { + dut.t.Helper() + ret, err := dut.CloseWithErrno(fd) + if ret != 0 { + dut.t.Fatalf("failed to close: %s", err) + } +} + +// CreateListener makes a new TCP connection. If it fails, the test ends. +func (dut *DUT) CreateListener(typ, proto, backlog int32) (int32, uint16) { + dut.t.Helper() + addr := net.ParseIP(*remoteIPv4) + var fd int32 + if addr.To4() != nil { + fd = dut.Socket(unix.AF_INET, typ, proto) + sa := unix.SockaddrInet4{} + copy(sa.Addr[:], addr.To4()) + dut.Bind(fd, &sa) + } else if addr.To16() != nil { + fd = dut.Socket(unix.AF_INET6, typ, proto) + sa := unix.SockaddrInet6{} + copy(sa.Addr[:], addr.To16()) + dut.Bind(fd, &sa) + } else { + dut.t.Fatal("unknown ip addr type for remoteIP") + } + sa := dut.GetSockName(fd) + var port int + switch s := sa.(type) { + case *unix.SockaddrInet4: + port = s.Port + case *unix.SockaddrInet6: + port = s.Port + default: + dut.t.Fatalf("unknown sockaddr type from getsockname: %t", sa) + } + dut.Listen(fd, backlog) + return fd, uint16(port) +} diff --git a/test/packetimpact/testbench/dut_client.go b/test/packetimpact/testbench/dut_client.go new file mode 100644 index 000000000..b130a33a2 --- /dev/null +++ b/test/packetimpact/testbench/dut_client.go @@ -0,0 +1,28 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package testbench + +import ( + "google.golang.org/grpc" + pb "gvisor.dev/gvisor/test/packetimpact/proto/posix_server_go_proto" +) + +// PosixClient is a gRPC client for the Posix service. +type PosixClient pb.PosixClient + +// NewPosixClient makes a new gRPC client for the Posix service. +func NewPosixClient(c grpc.ClientConnInterface) PosixClient { + return pb.NewPosixClient(c) +} diff --git a/test/packetimpact/testbench/layers.go b/test/packetimpact/testbench/layers.go new file mode 100644 index 000000000..35fa4dcb6 --- /dev/null +++ b/test/packetimpact/testbench/layers.go @@ -0,0 +1,507 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package testbench + +import ( + "fmt" + "reflect" + + "github.com/google/go-cmp/cmp" + "github.com/google/go-cmp/cmp/cmpopts" + "github.com/imdario/mergo" + "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/tcpip/header" +) + +// Layer is the interface that all encapsulations must implement. +// +// A Layer is an encapsulation in a packet, such as TCP, IPv4, IPv6, etc. A +// Layer contains all the fields of the encapsulation. Each field is a pointer +// and may be nil. +type Layer interface { + // toBytes converts the Layer into bytes. In places where the Layer's field + // isn't nil, the value that is pointed to is used. When the field is nil, a + // reasonable default for the Layer is used. For example, "64" for IPv4 TTL + // and a calculated checksum for TCP or IP. Some layers require information + // from the previous or next layers in order to compute a default, such as + // TCP's checksum or Ethernet's type, so each Layer has a doubly-linked list + // to the layer's neighbors. + toBytes() ([]byte, error) + + // match checks if the current Layer matches the provided Layer. If either + // Layer has a nil in a given field, that field is considered matching. + // Otherwise, the values pointed to by the fields must match. + match(Layer) bool + + // length in bytes of the current encapsulation + length() int + + // next gets a pointer to the encapsulated Layer. + next() Layer + + // prev gets a pointer to the Layer encapsulating this one. + prev() Layer + + // setNext sets the pointer to the encapsulated Layer. + setNext(Layer) + + // setPrev sets the pointer to the Layer encapsulating this one. + setPrev(Layer) +} + +// LayerBase is the common elements of all layers. +type LayerBase struct { + nextLayer Layer + prevLayer Layer +} + +func (lb *LayerBase) next() Layer { + return lb.nextLayer +} + +func (lb *LayerBase) prev() Layer { + return lb.prevLayer +} + +func (lb *LayerBase) setNext(l Layer) { + lb.nextLayer = l +} + +func (lb *LayerBase) setPrev(l Layer) { + lb.prevLayer = l +} + +func equalLayer(x, y Layer) bool { + opt := cmp.FilterValues(func(x, y interface{}) bool { + if reflect.ValueOf(x).Kind() == reflect.Ptr && reflect.ValueOf(x).IsNil() { + return true + } + if reflect.ValueOf(y).Kind() == reflect.Ptr && reflect.ValueOf(y).IsNil() { + return true + } + return false + + }, cmp.Ignore()) + return cmp.Equal(x, y, opt, cmpopts.IgnoreUnexported(LayerBase{})) +} + +// Ether can construct and match the ethernet encapsulation. +type Ether struct { + LayerBase + SrcAddr *tcpip.LinkAddress + DstAddr *tcpip.LinkAddress + Type *tcpip.NetworkProtocolNumber +} + +func (l *Ether) toBytes() ([]byte, error) { + b := make([]byte, header.EthernetMinimumSize) + h := header.Ethernet(b) + fields := &header.EthernetFields{} + if l.SrcAddr != nil { + fields.SrcAddr = *l.SrcAddr + } + if l.DstAddr != nil { + fields.DstAddr = *l.DstAddr + } + if l.Type != nil { + fields.Type = *l.Type + } else { + switch n := l.next().(type) { + case *IPv4: + fields.Type = header.IPv4ProtocolNumber + default: + // TODO(b/150301488): Support more protocols, like IPv6. + return nil, fmt.Errorf("can't deduce the ethernet header's next protocol: %d", n) + } + } + h.Encode(fields) + return h, nil +} + +// LinkAddress is a helper routine that allocates a new tcpip.LinkAddress value +// to store v and returns a pointer to it. +func LinkAddress(v tcpip.LinkAddress) *tcpip.LinkAddress { + return &v +} + +// NetworkProtocolNumber is a helper routine that allocates a new +// tcpip.NetworkProtocolNumber value to store v and returns a pointer to it. +func NetworkProtocolNumber(v tcpip.NetworkProtocolNumber) *tcpip.NetworkProtocolNumber { + return &v +} + +// ParseEther parses the bytes assuming that they start with an ethernet header +// and continues parsing further encapsulations. +func ParseEther(b []byte) (Layers, error) { + h := header.Ethernet(b) + ether := Ether{ + SrcAddr: LinkAddress(h.SourceAddress()), + DstAddr: LinkAddress(h.DestinationAddress()), + Type: NetworkProtocolNumber(h.Type()), + } + layers := Layers{ðer} + switch h.Type() { + case header.IPv4ProtocolNumber: + moreLayers, err := ParseIPv4(b[ether.length():]) + if err != nil { + return nil, err + } + return append(layers, moreLayers...), nil + default: + // TODO(b/150301488): Support more protocols, like IPv6. + return nil, fmt.Errorf("can't deduce the ethernet header's next protocol: %v", b) + } +} + +func (l *Ether) match(other Layer) bool { + return equalLayer(l, other) +} + +func (l *Ether) length() int { + return header.EthernetMinimumSize +} + +// IPv4 can construct and match the ethernet excapulation. +type IPv4 struct { + LayerBase + IHL *uint8 + TOS *uint8 + TotalLength *uint16 + ID *uint16 + Flags *uint8 + FragmentOffset *uint16 + TTL *uint8 + Protocol *uint8 + Checksum *uint16 + SrcAddr *tcpip.Address + DstAddr *tcpip.Address +} + +func (l *IPv4) toBytes() ([]byte, error) { + b := make([]byte, header.IPv4MinimumSize) + h := header.IPv4(b) + fields := &header.IPv4Fields{ + IHL: 20, + TOS: 0, + TotalLength: 0, + ID: 0, + Flags: 0, + FragmentOffset: 0, + TTL: 64, + Protocol: 0, + Checksum: 0, + SrcAddr: tcpip.Address(""), + DstAddr: tcpip.Address(""), + } + if l.TOS != nil { + fields.TOS = *l.TOS + } + if l.TotalLength != nil { + fields.TotalLength = *l.TotalLength + } else { + fields.TotalLength = uint16(l.length()) + current := l.next() + for current != nil { + fields.TotalLength += uint16(current.length()) + current = current.next() + } + } + if l.ID != nil { + fields.ID = *l.ID + } + if l.Flags != nil { + fields.Flags = *l.Flags + } + if l.FragmentOffset != nil { + fields.FragmentOffset = *l.FragmentOffset + } + if l.TTL != nil { + fields.TTL = *l.TTL + } + if l.Protocol != nil { + fields.Protocol = *l.Protocol + } else { + switch n := l.next().(type) { + case *TCP: + fields.Protocol = uint8(header.TCPProtocolNumber) + default: + // TODO(b/150301488): Support more protocols, like UDP. + return nil, fmt.Errorf("can't deduce the ip header's next protocol: %+v", n) + } + } + if l.SrcAddr != nil { + fields.SrcAddr = *l.SrcAddr + } + if l.DstAddr != nil { + fields.DstAddr = *l.DstAddr + } + if l.Checksum != nil { + fields.Checksum = *l.Checksum + } + h.Encode(fields) + if l.Checksum == nil { + h.SetChecksum(^h.CalculateChecksum()) + } + return h, nil +} + +// Uint16 is a helper routine that allocates a new +// uint16 value to store v and returns a pointer to it. +func Uint16(v uint16) *uint16 { + return &v +} + +// Uint8 is a helper routine that allocates a new +// uint8 value to store v and returns a pointer to it. +func Uint8(v uint8) *uint8 { + return &v +} + +// Address is a helper routine that allocates a new tcpip.Address value to store +// v and returns a pointer to it. +func Address(v tcpip.Address) *tcpip.Address { + return &v +} + +// ParseIPv4 parses the bytes assuming that they start with an ipv4 header and +// continues parsing further encapsulations. +func ParseIPv4(b []byte) (Layers, error) { + h := header.IPv4(b) + tos, _ := h.TOS() + ipv4 := IPv4{ + IHL: Uint8(h.HeaderLength()), + TOS: &tos, + TotalLength: Uint16(h.TotalLength()), + ID: Uint16(h.ID()), + Flags: Uint8(h.Flags()), + FragmentOffset: Uint16(h.FragmentOffset()), + TTL: Uint8(h.TTL()), + Protocol: Uint8(h.Protocol()), + Checksum: Uint16(h.Checksum()), + SrcAddr: Address(h.SourceAddress()), + DstAddr: Address(h.DestinationAddress()), + } + layers := Layers{&ipv4} + switch h.Protocol() { + case uint8(header.TCPProtocolNumber): + moreLayers, err := ParseTCP(b[ipv4.length():]) + if err != nil { + return nil, err + } + return append(layers, moreLayers...), nil + } + return nil, fmt.Errorf("can't deduce the ethernet header's next protocol: %d", h.Protocol()) +} + +func (l *IPv4) match(other Layer) bool { + return equalLayer(l, other) +} + +func (l *IPv4) length() int { + if l.IHL == nil { + return header.IPv4MinimumSize + } + return int(*l.IHL) +} + +// TCP can construct and match the TCP excapulation. +type TCP struct { + LayerBase + SrcPort *uint16 + DstPort *uint16 + SeqNum *uint32 + AckNum *uint32 + DataOffset *uint8 + Flags *uint8 + WindowSize *uint16 + Checksum *uint16 + UrgentPointer *uint16 +} + +func (l *TCP) toBytes() ([]byte, error) { + b := make([]byte, header.TCPMinimumSize) + h := header.TCP(b) + if l.SrcPort != nil { + h.SetSourcePort(*l.SrcPort) + } + if l.DstPort != nil { + h.SetDestinationPort(*l.DstPort) + } + if l.SeqNum != nil { + h.SetSequenceNumber(*l.SeqNum) + } + if l.AckNum != nil { + h.SetAckNumber(*l.AckNum) + } + if l.DataOffset != nil { + h.SetDataOffset(*l.DataOffset) + } + if l.Flags != nil { + h.SetFlags(*l.Flags) + } + if l.WindowSize != nil { + h.SetWindowSize(*l.WindowSize) + } + if l.UrgentPointer != nil { + h.SetUrgentPoiner(*l.UrgentPointer) + } + if l.Checksum != nil { + h.SetChecksum(*l.Checksum) + return h, nil + } + if err := setChecksum(&h, l); err != nil { + return nil, err + } + return h, nil +} + +// setChecksum calculates the checksum of the TCP header and sets it in h. +func setChecksum(h *header.TCP, tcp *TCP) error { + h.SetChecksum(0) + tcpLength := uint16(tcp.length()) + current := tcp.next() + for current != nil { + tcpLength += uint16(current.length()) + current = current.next() + } + + var xsum uint16 + switch s := tcp.prev().(type) { + case *IPv4: + xsum = header.PseudoHeaderChecksum(header.TCPProtocolNumber, *s.SrcAddr, *s.DstAddr, tcpLength) + default: + // TODO(b/150301488): Support more protocols, like IPv6. + return fmt.Errorf("can't get src and dst addr from previous layer") + } + current = tcp.next() + for current != nil { + payload, err := current.toBytes() + if err != nil { + return fmt.Errorf("can't get bytes for next header: %s", payload) + } + xsum = header.Checksum(payload, xsum) + current = current.next() + } + h.SetChecksum(^h.CalculateChecksum(xsum)) + return nil +} + +// Uint32 is a helper routine that allocates a new +// uint32 value to store v and returns a pointer to it. +func Uint32(v uint32) *uint32 { + return &v +} + +// ParseTCP parses the bytes assuming that they start with a tcp header and +// continues parsing further encapsulations. +func ParseTCP(b []byte) (Layers, error) { + h := header.TCP(b) + tcp := TCP{ + SrcPort: Uint16(h.SourcePort()), + DstPort: Uint16(h.DestinationPort()), + SeqNum: Uint32(h.SequenceNumber()), + AckNum: Uint32(h.AckNumber()), + DataOffset: Uint8(h.DataOffset()), + Flags: Uint8(h.Flags()), + WindowSize: Uint16(h.WindowSize()), + Checksum: Uint16(h.Checksum()), + UrgentPointer: Uint16(h.UrgentPointer()), + } + layers := Layers{&tcp} + moreLayers, err := ParsePayload(b[tcp.length():]) + if err != nil { + return nil, err + } + return append(layers, moreLayers...), nil +} + +func (l *TCP) match(other Layer) bool { + return equalLayer(l, other) +} + +func (l *TCP) length() int { + if l.DataOffset == nil { + return header.TCPMinimumSize + } + return int(*l.DataOffset) +} + +// merge overrides the values in l with the values from other but only in fields +// where the value is not nil. +func (l *TCP) merge(other TCP) error { + return mergo.Merge(l, other, mergo.WithOverride) +} + +// Payload has bytes beyond OSI layer 4. +type Payload struct { + LayerBase + Bytes []byte +} + +// ParsePayload parses the bytes assuming that they start with a payload and +// continue to the end. There can be no further encapsulations. +func ParsePayload(b []byte) (Layers, error) { + payload := Payload{ + Bytes: b, + } + return Layers{&payload}, nil +} + +func (l *Payload) toBytes() ([]byte, error) { + return l.Bytes, nil +} + +func (l *Payload) match(other Layer) bool { + return equalLayer(l, other) +} + +func (l *Payload) length() int { + return len(l.Bytes) +} + +// Layers is an array of Layer and supports similar functions to Layer. +type Layers []Layer + +func (ls *Layers) toBytes() ([]byte, error) { + for i, l := range *ls { + if i > 0 { + l.setPrev((*ls)[i-1]) + } + if i+1 < len(*ls) { + l.setNext((*ls)[i+1]) + } + } + outBytes := []byte{} + for _, l := range *ls { + layerBytes, err := l.toBytes() + if err != nil { + return nil, err + } + outBytes = append(outBytes, layerBytes...) + } + return outBytes, nil +} + +func (ls *Layers) match(other Layers) bool { + if len(*ls) > len(other) { + return false + } + for i := 0; i < len(*ls); i++ { + if !equalLayer((*ls)[i], other[i]) { + return false + } + } + return true +} diff --git a/test/packetimpact/testbench/rawsockets.go b/test/packetimpact/testbench/rawsockets.go new file mode 100644 index 000000000..0c7d0f979 --- /dev/null +++ b/test/packetimpact/testbench/rawsockets.go @@ -0,0 +1,151 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package testbench + +import ( + "encoding/binary" + "flag" + "math" + "net" + "testing" + "time" + + "golang.org/x/sys/unix" + "gvisor.dev/gvisor/pkg/usermem" +) + +var device = flag.String("device", "", "local device for test packets") + +// Sniffer can sniff raw packets on the wire. +type Sniffer struct { + t *testing.T + fd int +} + +func htons(x uint16) uint16 { + buf := [2]byte{} + binary.BigEndian.PutUint16(buf[:], x) + return usermem.ByteOrder.Uint16(buf[:]) +} + +// NewSniffer creates a Sniffer connected to *device. +func NewSniffer(t *testing.T) (Sniffer, error) { + flag.Parse() + snifferFd, err := unix.Socket(unix.AF_PACKET, unix.SOCK_RAW, int(htons(unix.ETH_P_ALL))) + if err != nil { + return Sniffer{}, err + } + return Sniffer{ + t: t, + fd: snifferFd, + }, nil +} + +// maxReadSize should be large enough for the maximum frame size in bytes. If a +// packet too large for the buffer arrives, the test will get a fatal error. +const maxReadSize int = 65536 + +// Recv tries to read one frame until the timeout is up. +func (s *Sniffer) Recv(timeout time.Duration) []byte { + deadline := time.Now().Add(timeout) + for { + timeout = deadline.Sub(time.Now()) + if timeout <= 0 { + return nil + } + whole, frac := math.Modf(timeout.Seconds()) + tv := unix.Timeval{ + Sec: int64(whole), + Usec: int64(frac * float64(time.Microsecond/time.Second)), + } + + if err := unix.SetsockoptTimeval(s.fd, unix.SOL_SOCKET, unix.SO_RCVTIMEO, &tv); err != nil { + s.t.Fatalf("can't setsockopt SO_RCVTIMEO: %s", err) + } + + buf := make([]byte, maxReadSize) + nread, _, err := unix.Recvfrom(s.fd, buf, unix.MSG_TRUNC) + if err == unix.EINTR || err == unix.EAGAIN { + // There was a timeout. + continue + } + if err != nil { + s.t.Fatalf("can't read: %s", err) + } + if nread > maxReadSize { + s.t.Fatalf("received a truncated frame of %d bytes", nread) + } + return buf[:nread] + } +} + +// Close the socket that Sniffer is using. +func (s *Sniffer) Close() { + if err := unix.Close(s.fd); err != nil { + s.t.Fatalf("can't close sniffer socket: %s", err) + } + s.fd = -1 +} + +// Injector can inject raw frames. +type Injector struct { + t *testing.T + fd int +} + +// NewInjector creates a new injector on *device. +func NewInjector(t *testing.T) (Injector, error) { + flag.Parse() + ifInfo, err := net.InterfaceByName(*device) + if err != nil { + return Injector{}, err + } + + var haddr [8]byte + copy(haddr[:], ifInfo.HardwareAddr) + sa := unix.SockaddrLinklayer{ + Protocol: unix.ETH_P_IP, + Ifindex: ifInfo.Index, + Halen: uint8(len(ifInfo.HardwareAddr)), + Addr: haddr, + } + + injectFd, err := unix.Socket(unix.AF_PACKET, unix.SOCK_RAW, int(htons(unix.ETH_P_ALL))) + if err != nil { + return Injector{}, err + } + if err := unix.Bind(injectFd, &sa); err != nil { + return Injector{}, err + } + return Injector{ + t: t, + fd: injectFd, + }, nil +} + +// Send a raw frame. +func (i *Injector) Send(b []byte) { + if _, err := unix.Write(i.fd, b); err != nil { + i.t.Fatalf("can't write: %s", err) + } +} + +// Close the underlying socket. +func (i *Injector) Close() { + if err := unix.Close(i.fd); err != nil { + i.t.Fatalf("can't close sniffer socket: %s", err) + } + i.fd = -1 +} diff --git a/test/packetimpact/tests/BUILD b/test/packetimpact/tests/BUILD new file mode 100644 index 000000000..1dff2a4d5 --- /dev/null +++ b/test/packetimpact/tests/BUILD @@ -0,0 +1,21 @@ +load("defs.bzl", "packetimpact_go_test") + +package( + default_visibility = ["//test/packetimpact:__subpackages__"], + licenses = ["notice"], +) + +packetimpact_go_test( + name = "fin_wait2_timeout", + srcs = ["fin_wait2_timeout_test.go"], + deps = [ + "//pkg/tcpip/header", + "//test/packetimpact/testbench", + "@org_golang_x_sys//unix:go_default_library", + ], +) + +sh_binary( + name = "test_runner", + srcs = ["test_runner.sh"], +) diff --git a/test/packetimpact/tests/Dockerfile b/test/packetimpact/tests/Dockerfile new file mode 100644 index 000000000..507030cc7 --- /dev/null +++ b/test/packetimpact/tests/Dockerfile @@ -0,0 +1,5 @@ +FROM ubuntu:bionic + +RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y iptables netcat tcpdump iproute2 tshark +RUN hash -r +CMD /bin/bash diff --git a/test/packetimpact/tests/defs.bzl b/test/packetimpact/tests/defs.bzl new file mode 100644 index 000000000..1b4213d9b --- /dev/null +++ b/test/packetimpact/tests/defs.bzl @@ -0,0 +1,106 @@ +"""Defines rules for packetimpact test targets.""" + +load("//tools:defs.bzl", "go_test") + +def _packetimpact_test_impl(ctx): + test_runner = ctx.executable._test_runner + bench = ctx.actions.declare_file("%s-bench" % ctx.label.name) + bench_content = "\n".join([ + "#!/bin/bash", + # This test will run part in a distinct user namespace. This can cause + # permission problems, because all runfiles may not be owned by the + # current user, and no other users will be mapped in that namespace. + # Make sure that everything is readable here. + "find . -type f -exec chmod a+rx {} \\;", + "find . -type d -exec chmod a+rx {} \\;", + "%s %s --posix_server_binary %s --testbench_binary %s $@\n" % ( + test_runner.short_path, + " ".join(ctx.attr.flags), + ctx.files._posix_server_binary[0].short_path, + ctx.files.testbench_binary[0].short_path, + ), + ]) + ctx.actions.write(bench, bench_content, is_executable = True) + + transitive_files = depset() + if hasattr(ctx.attr._test_runner, "data_runfiles"): + transitive_files = depset(ctx.attr._test_runner.data_runfiles.files) + runfiles = ctx.runfiles( + files = [test_runner] + ctx.files.testbench_binary + ctx.files._posix_server_binary, + transitive_files = transitive_files, + collect_default = True, + collect_data = True, + ) + return [DefaultInfo(executable = bench, runfiles = runfiles)] + +_packetimpact_test = rule( + attrs = { + "_test_runner": attr.label( + executable = True, + cfg = "target", + default = ":test_runner", + ), + "_posix_server_binary": attr.label( + cfg = "target", + default = "//test/packetimpact/dut:posix_server", + ), + "testbench_binary": attr.label( + cfg = "target", + mandatory = True, + ), + "flags": attr.string_list( + mandatory = False, + default = [], + ), + }, + test = True, + implementation = _packetimpact_test_impl, +) + +PACKETIMPACT_TAGS = ["local", "manual"] + +def packetimpact_linux_test(name, testbench_binary, **kwargs): + """Add a packetimpact test on linux. + + Args: + name: name of the test + testbench_binary: the testbench binary + **kwargs: all the other args, forwarded to _packetimpact_test + """ + _packetimpact_test( + name = name + "_linux_test", + testbench_binary = testbench_binary, + flags = ["--dut_platform", "linux"], + tags = PACKETIMPACT_TAGS + ["packetimpact"], + **kwargs + ) + +def packetimpact_netstack_test(name, testbench_binary, **kwargs): + """Add a packetimpact test on netstack. + + Args: + name: name of the test + testbench_binary: the testbench binary + **kwargs: all the other args, forwarded to _packetimpact_test + """ + _packetimpact_test( + name = name + "_netstack_test", + testbench_binary = testbench_binary, + # This is the default runtime unless + # "--test_arg=--runtime=OTHER_RUNTIME" is used to override the value. + flags = ["--dut_platform", "netstack", "--runtime=runsc-d"], + tags = PACKETIMPACT_TAGS + ["packetimpact"], + **kwargs + ) + +def packetimpact_go_test(name, size = "small", pure = True, **kwargs): + testbench_binary = name + "_test" + go_test( + name = testbench_binary, + size = size, + pure = pure, + tags = PACKETIMPACT_TAGS, + **kwargs + ) + packetimpact_linux_test(name = name, testbench_binary = testbench_binary) + packetimpact_netstack_test(name = name, testbench_binary = testbench_binary) diff --git a/test/packetimpact/tests/fin_wait2_timeout_test.go b/test/packetimpact/tests/fin_wait2_timeout_test.go new file mode 100644 index 000000000..5f54e67ed --- /dev/null +++ b/test/packetimpact/tests/fin_wait2_timeout_test.go @@ -0,0 +1,68 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package fin_wait2_timeout_test + +import ( + "testing" + "time" + + "golang.org/x/sys/unix" + "gvisor.dev/gvisor/pkg/tcpip/header" + tb "gvisor.dev/gvisor/test/packetimpact/testbench" +) + +func TestFinWait2Timeout(t *testing.T) { + for _, tt := range []struct { + description string + linger2 bool + }{ + {"WithLinger2", true}, + {"WithoutLinger2", false}, + } { + t.Run(tt.description, func(t *testing.T) { + dut := tb.NewDUT(t) + defer dut.TearDown() + listenFd, remotePort := dut.CreateListener(unix.SOCK_STREAM, unix.IPPROTO_TCP, 1) + defer dut.Close(listenFd) + conn := tb.NewTCPIPv4(t, dut, tb.TCP{DstPort: &remotePort}, tb.TCP{SrcPort: &remotePort}) + defer conn.Close() + conn.Handshake() + + acceptFd, _ := dut.Accept(listenFd) + if tt.linger2 { + tv := unix.Timeval{Sec: 1, Usec: 0} + dut.SetSockOptTimeval(acceptFd, unix.SOL_TCP, unix.TCP_LINGER2, &tv) + } + dut.Close(acceptFd) + + if gotOne := conn.Expect(tb.TCP{Flags: tb.Uint8(header.TCPFlagFin | header.TCPFlagAck)}, time.Second); gotOne == nil { + t.Fatal("expected a FIN-ACK within 1 second but got none") + } + conn.Send(tb.TCP{Flags: tb.Uint8(header.TCPFlagAck)}) + + time.Sleep(5 * time.Second) + conn.Send(tb.TCP{Flags: tb.Uint8(header.TCPFlagAck)}) + if tt.linger2 { + if gotOne := conn.Expect(tb.TCP{Flags: tb.Uint8(header.TCPFlagRst)}, time.Second); gotOne == nil { + t.Fatal("expected a RST packet within a second but got none") + } + } else { + if gotOne := conn.Expect(tb.TCP{Flags: tb.Uint8(header.TCPFlagRst)}, 10*time.Second); gotOne != nil { + t.Fatal("expected no RST packets within ten seconds but got one") + } + } + }) + } +} diff --git a/test/packetimpact/tests/test_runner.sh b/test/packetimpact/tests/test_runner.sh new file mode 100755 index 000000000..5281cb53d --- /dev/null +++ b/test/packetimpact/tests/test_runner.sh @@ -0,0 +1,246 @@ +#!/bin/bash + +# Copyright 2020 The gVisor Authors. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +# Run a packetimpact test. Two docker containers are made, one for the +# Device-Under-Test (DUT) and one for the test bench. Each is attached with +# two networks, one for control packets that aid the test and one for test +# packets which are sent as part of the test and observed for correctness. + +set -euxo pipefail + +function failure() { + local lineno=$1 + local msg=$2 + local filename="$0" + echo "FAIL: $filename:$lineno: $msg" +} +trap 'failure ${LINENO} "$BASH_COMMAND"' ERR + +declare -r LONGOPTS="dut_platform:,posix_server_binary:,testbench_binary:,runtime:,tshark" + +# Don't use declare below so that the error from getopt will end the script. +PARSED=$(getopt --options "" --longoptions=$LONGOPTS --name "$0" -- "$@") + +eval set -- "$PARSED" + +while true; do + case "$1" in + --dut_platform) + # Either "linux" or "netstack". + declare -r DUT_PLATFORM="$2" + shift 2 + ;; + --posix_server_binary) + declare -r POSIX_SERVER_BINARY="$2" + shift 2 + ;; + --testbench_binary) + declare -r TESTBENCH_BINARY="$2" + shift 2 + ;; + --runtime) + # Not readonly because there might be multiple --runtime arguments and we + # want to use just the last one. Only used if --dut_platform is + # "netstack". + declare RUNTIME="$2" + shift 2 + ;; + --tshark) + declare -r TSHARK="1" + shift 1 + ;; + --) + shift + break + ;; + *) + echo "Programming error" + exit 3 + esac +done + +# All the other arguments are scripts. +declare -r scripts="$@" + +# Check that the required flags are defined in a way that is safe for "set -u". +if [[ "${DUT_PLATFORM-}" == "netstack" ]]; then + if [[ -z "${RUNTIME-}" ]]; then + echo "FAIL: Missing --runtime argument: ${RUNTIME-}" + exit 2 + fi + declare -r RUNTIME_ARG="--runtime ${RUNTIME}" +elif [[ "${DUT_PLATFORM-}" == "linux" ]]; then + declare -r RUNTIME_ARG="" +else + echo "FAIL: Bad or missing --dut_platform argument: ${DUT_PLATFORM-}" + exit 2 +fi +if [[ ! -f "${POSIX_SERVER_BINARY-}" ]]; then + echo "FAIL: Bad or missing --posix_server_binary: ${POSIX_SERVER-}" + exit 2 +fi +if [[ ! -f "${TESTBENCH_BINARY-}" ]]; then + echo "FAIL: Bad or missing --testbench_binary: ${TESTBENCH_BINARY-}" + exit 2 +fi + +# Variables specific to the control network and interface start with CTRL_. +# Variables specific to the test network and interface start with TEST_. +# Variables specific to the DUT start with DUT_. +# Variables specific to the test bench start with TESTBENCH_. +# Use random numbers so that test networks don't collide. +declare -r CTRL_NET="ctrl_net-${RANDOM}${RANDOM}" +declare -r TEST_NET="test_net-${RANDOM}${RANDOM}" +# On both DUT and test bench, testing packets are on the eth2 interface. +declare -r TEST_DEVICE="eth2" +# Number of bits in the *_NET_PREFIX variables. +declare -r NET_MASK="24" +function new_net_prefix() { + # Class C, 192.0.0.0 to 223.255.255.255, transitionally has mask 24. + echo "$(shuf -i 192-223 -n 1).$(shuf -i 0-255 -n 1).$(shuf -i 0-255 -n 1)" +} +# Last bits of the DUT's IP address. +declare -r DUT_NET_SUFFIX=".10" +# Control port. +declare -r CTRL_PORT="40000" +# Last bits of the test bench's IP address. +declare -r TESTBENCH_NET_SUFFIX=".20" +declare -r TIMEOUT="60" +declare -r IMAGE_TAG="gcr.io/gvisor-presubmit/packetimpact" +# Make sure that docker is installed. +docker --version + +function finish { + local cleanup_success=1 + for net in "${CTRL_NET}" "${TEST_NET}"; do + # Kill all processes attached to ${net}. + for docker_command in "kill" "rm"; do + (docker network inspect "${net}" \ + --format '{{range $key, $value := .Containers}}{{$key}} {{end}}' \ + | xargs -r docker "${docker_command}") || \ + cleanup_success=0 + done + # Remove the network. + docker network rm "${net}" || \ + cleanup_success=0 + done + + if ((!$cleanup_success)); then + echo "FAIL: Cleanup command failed" + exit 4 + fi +} +trap finish EXIT + +# Subnet for control packets between test bench and DUT. +declare CTRL_NET_PREFIX=$(new_net_prefix) +while ! docker network create \ + "--subnet=${CTRL_NET_PREFIX}.0/${NET_MASK}" "${CTRL_NET}"; do + sleep 0.1 + declare CTRL_NET_PREFIX=$(new_net_prefix) +done + +# Subnet for the packets that are part of the test. +declare TEST_NET_PREFIX=$(new_net_prefix) +while ! docker network create \ + "--subnet=${TEST_NET_PREFIX}.0/${NET_MASK}" "${TEST_NET}"; do + sleep 0.1 + declare TEST_NET_PREFIX=$(new_net_prefix) +done + +docker pull "${IMAGE_TAG}" + +# Create the DUT container and connect to network. +DUT=$(docker create ${RUNTIME_ARG} --privileged --rm \ + --stop-timeout ${TIMEOUT} -it ${IMAGE_TAG}) +docker network connect "${CTRL_NET}" \ + --ip "${CTRL_NET_PREFIX}${DUT_NET_SUFFIX}" "${DUT}" \ + || (docker kill ${DUT}; docker rm ${DUT}; false) +docker network connect "${TEST_NET}" \ + --ip "${TEST_NET_PREFIX}${DUT_NET_SUFFIX}" "${DUT}" \ + || (docker kill ${DUT}; docker rm ${DUT}; false) +docker start "${DUT}" + +# Create the test bench container and connect to network. +TESTBENCH=$(docker create --privileged --rm \ + --stop-timeout ${TIMEOUT} -it ${IMAGE_TAG}) +docker network connect "${CTRL_NET}" \ + --ip "${CTRL_NET_PREFIX}${TESTBENCH_NET_SUFFIX}" "${TESTBENCH}" \ + || (docker kill ${TESTBENCH}; docker rm ${TESTBENCH}; false) +docker network connect "${TEST_NET}" \ + --ip "${TEST_NET_PREFIX}${TESTBENCH_NET_SUFFIX}" "${TESTBENCH}" \ + || (docker kill ${TESTBENCH}; docker rm ${TESTBENCH}; false) +docker start "${TESTBENCH}" + +# Start the posix_server in the DUT. +declare -r DOCKER_POSIX_SERVER_BINARY="/$(basename ${POSIX_SERVER_BINARY})" +docker cp -L ${POSIX_SERVER_BINARY} "${DUT}:${DOCKER_POSIX_SERVER_BINARY}" + +docker exec -t "${DUT}" \ + /bin/bash -c "${DOCKER_POSIX_SERVER_BINARY} \ + --ip ${CTRL_NET_PREFIX}${DUT_NET_SUFFIX} \ + --port ${CTRL_PORT}" & + +# Because the Linux kernel receives the SYN-ACK but didn't send the SYN it will +# issue a RST. To prevent this IPtables can be used to filter those out. +docker exec "${TESTBENCH}" \ + iptables -A INPUT -i ${TEST_DEVICE} -j DROP + +# Wait for the DUT server to come up. Attempt to connect to it from the test +# bench every 100 milliseconds until success. +while ! docker exec "${TESTBENCH}" \ + nc -zv "${CTRL_NET_PREFIX}${DUT_NET_SUFFIX}" "${CTRL_PORT}"; do + sleep 0.1 +done + +declare -r REMOTE_MAC=$(docker exec -t "${DUT}" ip link show \ + "${TEST_DEVICE}" | tail -1 | cut -d' ' -f6) +declare -r LOCAL_MAC=$(docker exec -t "${TESTBENCH}" ip link show \ + "${TEST_DEVICE}" | tail -1 | cut -d' ' -f6) + +declare -r DOCKER_TESTBENCH_BINARY="/$(basename ${TESTBENCH_BINARY})" +docker cp -L "${TESTBENCH_BINARY}" "${TESTBENCH}:${DOCKER_TESTBENCH_BINARY}" + +if [[ -z "${TSHARK-}" ]]; then + # Run tcpdump in the test bench unbuffered, without dns resolution, just on + # the interface with the test packets. + docker exec -t "${TESTBENCH}" \ + tcpdump -S -vvv -U -n -i "${TEST_DEVICE}" net "${TEST_NET_PREFIX}/24" & +else + # Run tshark in the test bench unbuffered, without dns resolution, just on the + # interface with the test packets. + docker exec -t "${TESTBENCH}" \ + tshark -V -l -n -i "${TEST_DEVICE}" \ + host "${TEST_NET_PREFIX}${TESTBENCH_NET_SUFFIX}" & +fi + +# tcpdump and tshark take time to startup +sleep 3 + +# Start a packetimpact test on the test bench. The packetimpact test sends and +# receives packets and also sends POSIX socket commands to the posix_server to +# be executed on the DUT. +docker exec -t "${TESTBENCH}" \ + /bin/bash -c "${DOCKER_TESTBENCH_BINARY} \ + --posix_server_ip=${CTRL_NET_PREFIX}${DUT_NET_SUFFIX} \ + --posix_server_port=${CTRL_PORT} \ + --remote_ipv4=${TEST_NET_PREFIX}${DUT_NET_SUFFIX} \ + --local_ipv4=${TEST_NET_PREFIX}${TESTBENCH_NET_SUFFIX} \ + --remote_mac=${REMOTE_MAC} \ + --local_mac=${LOCAL_MAC} \ + --device=${TEST_DEVICE}" + +echo PASS: No errors. |