Open source system call tests.

PiperOrigin-RevId: 224886231
Change-Id: I0fccb4d994601739d8b16b1d4e6b31f40297fb22

1 files changed, 100 insertions, 0 deletions

diff --git a/test/syscalls/linux/socket_netlink_util.cc b/test/syscalls/linux/socket_netlink_util.cc
new file mode 100644
index 000000000..ee0e03966
--- /dev/null
+++ b/test/syscalls/linux/socket_netlink_util.cc
@@ -0,0 +1,100 @@
+// Copyright 2018 Google LLC
+//
+// 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/if_arp.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+#include <sys/socket.h>
+#include <vector>
+
+#include "absl/strings/str_cat.h"
+#include "test/syscalls/linux/socket_netlink_util.h"
+#include "test/syscalls/linux/socket_test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+PosixErrorOr<FileDescriptor> NetlinkBoundSocket() {
+  FileDescriptor fd;
+  ASSIGN_OR_RETURN_ERRNO(fd, Socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE));
+
+  struct sockaddr_nl addr = {};
+  addr.nl_family = AF_NETLINK;
+
+  RETURN_ERROR_IF_SYSCALL_FAIL(
+      bind(fd.get(), reinterpret_cast<struct sockaddr*>(&addr), sizeof(addr)));
+  MaybeSave();
+
+  return std::move(fd);
+}
+
+PosixErrorOr<uint32_t> NetlinkPortID(int fd) {
+  struct sockaddr_nl addr;
+  socklen_t addrlen = sizeof(addr);
+
+  RETURN_ERROR_IF_SYSCALL_FAIL(
+      getsockname(fd, reinterpret_cast<struct sockaddr*>(&addr), &addrlen));
+  MaybeSave();
+
+  return static_cast<uint32_t>(addr.nl_pid);
+}
+
+PosixError NetlinkRequestResponse(
+    const FileDescriptor& fd, void* request, size_t len,
+    const std::function<void(const struct nlmsghdr* hdr)>& fn) {
+  struct iovec iov = {};
+  iov.iov_base = request;
+  iov.iov_len = len;
+
+  struct msghdr msg = {};
+  msg.msg_iov = &iov;
+  msg.msg_iovlen = 1;
+  // No destination required; it defaults to pid 0, the kernel.
+
+  RETURN_ERROR_IF_SYSCALL_FAIL(RetryEINTR(sendmsg)(fd.get(), &msg, 0));
+
+  constexpr size_t kBufferSize = 4096;
+  std::vector<char> buf(kBufferSize);
+  iov.iov_base = buf.data();
+  iov.iov_len = buf.size();
+
+  // Response is a series of NLM_F_MULTI messages, ending with a NLMSG_DONE
+  // message.
+  int type = -1;
+  do {
+    int len;
+    RETURN_ERROR_IF_SYSCALL_FAIL(len = RetryEINTR(recvmsg)(fd.get(), &msg, 0));
+
+    // We don't bother with the complexity of dealing with truncated messages.
+    // We must allocate a large enough buffer up front.
+    if ((msg.msg_flags & MSG_TRUNC) == MSG_TRUNC) {
+      return PosixError(EIO,
+                        absl::StrCat("Received truncated message with flags: ",
+                                     msg.msg_flags));
+    }
+
+    for (struct nlmsghdr* hdr = reinterpret_cast<struct nlmsghdr*>(buf.data());
+         NLMSG_OK(hdr, len); hdr = NLMSG_NEXT(hdr, len)) {
+      fn(hdr);
+      type = hdr->nlmsg_type;
+    }
+  } while (type != NLMSG_DONE && type != NLMSG_ERROR);
+
+  EXPECT_EQ(type, NLMSG_DONE);
+  return NoError();
+}
+
+}  // namespace testing
+}  // namespace gvisor