Run :socket_inet_loopback_isolated_test_linux tests in a container.

This creates new user and network namespaces for all tests in
`:socket_inet_loopback_isolated_test_linux`.

PiperOrigin-RevId: 381374120

test/runner/BUILD

@@ -8,6 +8,7 @@ go_binary(
     srcs = ["main.go"],
     data = [
         "//runsc",
+        "//test/runner/setup_container",
     ],
     visibility = ["//:sandbox"],
     deps = [

test/runner/defs.bzl

@@ -103,6 +103,8 @@ def _syscall_test(
     if platform == "native":
         tags.append("nogotsan")
 
+    container = "container" in tags
+
     runner_args = [
         # Arguments are passed directly to runner binary.
         "--platform=" + platform,
@@ -115,6 +117,7 @@ def _syscall_test(
         "--fuse=" + str(fuse),
         "--strace=" + str(debug),
         "--debug=" + str(debug),
+        "--container=" + str(container),
     ]
 
     # Call the rule above.

test/runner/main.go

@@ -40,16 +40,18 @@ import (
 )
 
 var (
-	debug      = flag.Bool("debug", false, "enable debug logs")
-	strace     = flag.Bool("strace", false, "enable strace logs")
-	platform   = flag.String("platform", "ptrace", "platform to run on")
-	network    = flag.String("network", "none", "network stack to run on (sandbox, host, none)")
-	useTmpfs   = flag.Bool("use-tmpfs", false, "mounts tmpfs for /tmp")
-	fileAccess = flag.String("file-access", "exclusive", "mounts root in exclusive or shared mode")
-	overlay    = flag.Bool("overlay", false, "wrap filesystem mounts with writable tmpfs overlay")
-	vfs2       = flag.Bool("vfs2", false, "enable VFS2")
-	fuse       = flag.Bool("fuse", false, "enable FUSE")
-	runscPath  = flag.String("runsc", "", "path to runsc binary")
+	debug              = flag.Bool("debug", false, "enable debug logs")
+	strace             = flag.Bool("strace", false, "enable strace logs")
+	platform           = flag.String("platform", "ptrace", "platform to run on")
+	network            = flag.String("network", "none", "network stack to run on (sandbox, host, none)")
+	useTmpfs           = flag.Bool("use-tmpfs", false, "mounts tmpfs for /tmp")
+	fileAccess         = flag.String("file-access", "exclusive", "mounts root in exclusive or shared mode")
+	overlay            = flag.Bool("overlay", false, "wrap filesystem mounts with writable tmpfs overlay")
+	vfs2               = flag.Bool("vfs2", false, "enable VFS2")
+	fuse               = flag.Bool("fuse", false, "enable FUSE")
+	container          = flag.Bool("container", false, "run tests in their own namespaces (user ns, network ns, etc), pretending to be root")
+	setupContainerPath = flag.String("setup-container", "", "path to setup_container binary (for use with --container)")
+	runscPath          = flag.String("runsc", "", "path to runsc binary")
 
 	addUDSTree = flag.Bool("add-uds-tree", false, "expose a tree of UDS utilities for use in tests")
 	// TODO(gvisor.dev/issue/4572): properly support leak checking for runsc, and
@@ -105,6 +107,27 @@ func runTestCaseNative(testBin string, tc gtest.TestCase, t *testing.T) {
 	cmd.Stderr = os.Stderr
 	cmd.SysProcAttr = &unix.SysProcAttr{}
 
+	if *container {
+		// setup_container takes in its target argv as positional arguments.
+		cmd.Path = *setupContainerPath
+		cmd.Args = append([]string{cmd.Path}, cmd.Args...)
+		cmd.SysProcAttr = &unix.SysProcAttr{
+			Cloneflags: unix.CLONE_NEWUSER | unix.CLONE_NEWNET | unix.CLONE_NEWIPC | unix.CLONE_NEWUTS,
+			// Set current user/group as root inside the namespace.
+			UidMappings: []syscall.SysProcIDMap{
+				{ContainerID: 0, HostID: os.Getuid(), Size: 1},
+			},
+			GidMappings: []syscall.SysProcIDMap{
+				{ContainerID: 0, HostID: os.Getgid(), Size: 1},
+			},
+			GidMappingsEnableSetgroups: false,
+			Credential: &syscall.Credential{
+				Uid: 0,
+				Gid: 0,
+			},
+		}
+	}
+
 	if specutils.HasCapabilities(capability.CAP_SYS_ADMIN) {
 		cmd.SysProcAttr.Cloneflags |= unix.CLONE_NEWUTS
 	}
@@ -454,6 +477,13 @@ func main() {
 		}
 		*runscPath = specutils.ExePath
 	}
+	if *container && *setupContainerPath == "" {
+		setupContainer, err := testutil.FindFile("test/runner/setup_container/setup_container")
+		if err != nil {
+			fatalf("cannot find setup_container: %v", err)
+		}
+		*setupContainerPath = setupContainer
+	}
 
 	// Make sure stdout and stderr are opened with O_APPEND, otherwise logs
 	// from outside the sandbox can (and will) stomp on logs from inside

test/runner/setup_container/BUILD

@@ -0,0 +1,19 @@
+# setup_container contains a shim binary that runs within the test container
+# for syscall tests with container=True.
+
+load("//tools:defs.bzl", "cc_binary")
+
+package(licenses = ["notice"])
+
+cc_binary(
+    name = "setup_container",
+    testonly = 1,
+    srcs = ["setup_container.cc"],
+    visibility = ["//test/runner:__subpackages__"],
+    deps = [
+        "//test/syscalls/linux:socket_netlink_util",
+        "//test/syscalls/linux:socket_test_util",
+        "//test/util:capability_util",
+        "//test/util:posix_error",
+    ],
+)

test/runner/setup_container/setup_container.cc

@@ -0,0 +1,79 @@
+// Copyright 2021 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 <linux/capability.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+#include "test/syscalls/linux/socket_netlink_util.h"
+#include "test/syscalls/linux/socket_test_util.h"
+#include "test/util/capability_util.h"
+#include "test/util/posix_error.h"
+
+namespace gvisor {
+namespace testing {
+
+// SetupContainer sets up the networking settings in the current container.
+PosixError SetupContainer() {
+  const PosixErrorOr<bool> have_net_admin = HaveCapability(CAP_NET_ADMIN);
+  if (!have_net_admin.ok()) {
+    std::cerr << "Cannot determine if we have CAP_NET_ADMIN." << std::endl;
+    return have_net_admin.error();
+  }
+  if (have_net_admin.ValueOrDie() && !IsRunningOnGvisor()) {
+    PosixErrorOr<FileDescriptor> sockfd = Socket(AF_INET, SOCK_DGRAM, 0);
+    if (!sockfd.ok()) {
+      std::cerr << "Cannot open socket." << std::endl;
+      return sockfd.error();
+    }
+    int sock = sockfd.ValueOrDie().get();
+    struct ifreq ifr = {};
+    strncpy(ifr.ifr_name, "lo", IFNAMSIZ);
+    if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) {
+      std::cerr << "Cannot get 'lo' flags: " << strerror(errno) << std::endl;
+      return PosixError(errno);
+    }
+    if ((ifr.ifr_flags & IFF_UP) == 0) {
+      ifr.ifr_flags |= IFF_UP;
+      if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) {
+        std::cerr << "Cannot set 'lo' as UP: " << strerror(errno) << std::endl;
+        return PosixError(errno);
+      }
+    }
+  }
+  return NoError();
+}
+
+}  // namespace testing
+}  // namespace gvisor
+
+using ::gvisor::testing::SetupContainer;
+
+// Binary setup_container initializes the container environment in which tests
+// with container=True will run, then execs the actual test binary.
+// Usage:
+//   ./setup_container test_binary [arguments forwarded to test_binary...]
+int main(int argc, char *argv[], char *envp[]) {
+  if (!SetupContainer().ok()) {
+    return 1;
+  }
+  if (argc < 2) {
+    std::cerr << "Must provide arguments to exec." << std::endl;
+    return 2;
+  }
+  if (execve(argv[1], &argv[1], envp) == -1) {
+    std::cerr << "execv returned errno " << errno << std::endl;
+    return 1;
+  }
+}

test/syscalls/BUILD

@@ -648,6 +648,7 @@ syscall_test(
 syscall_test(
     size = "large",
     shard_count = most_shards,
+    tags = ["container"],
     test = "//test/syscalls/linux:socket_inet_loopback_isolated_test",
 )
 

test/syscalls/linux/BUILD

@@ -3196,9 +3196,11 @@ cc_binary(
     linkstatic = 1,
     deps = [
         ":socket_inet_loopback_test_params",
+        ":socket_netlink_util",
         ":socket_test_util",
         gtest,
         "//test/util:test_main",
+        "//test/util:test_util",
         "@com_google_absl//absl/time",
     ],
 )

test/syscalls/linux/socket_inet_loopback_isolated.cc

@@ -19,6 +19,7 @@
 #include "absl/time/time.h"
 #include "test/syscalls/linux/socket_inet_loopback_test_params.h"
 #include "test/syscalls/linux/socket_test_util.h"
+#include "test/util/test_util.h"
 
 // Unit tests in this file will run in their own network namespace.