Add NETLINK_KOBJECT_UEVENT socket support

NETLINK_KOBJECT_UEVENT sockets send udev-style messages for device events.
gVisor doesn't have any device events, so our sockets don't need to do anything
once created.

systemd's device manager needs to be able to create one of these sockets. It
also wants to install a BPF filter on the socket. Since we'll never send any
messages, the filter would never be invoked, thus we just fake it out.

Fixes #1117
Updates #1119

PiperOrigin-RevId: 278405893

1 files changed, 23 insertions, 117 deletions

diff --git a/test/syscalls/linux/socket_netlink_route.cc b/test/syscalls/linux/socket_netlink_route.cc
index be0dadcd6..ef567f512 100644
--- a/test/syscalls/linux/socket_netlink_route.cc
+++ b/test/syscalls/linux/socket_netlink_route.cc
@@ -41,112 +41,7 @@ namespace {
 using ::testing::AnyOf;
 using ::testing::Eq;
 
-// Netlink sockets must be SOCK_DGRAM or SOCK_RAW.
-TEST(NetlinkRouteTest, Types) {
-  EXPECT_THAT(socket(AF_NETLINK, SOCK_STREAM, NETLINK_ROUTE),
-              SyscallFailsWithErrno(ESOCKTNOSUPPORT));
-  EXPECT_THAT(socket(AF_NETLINK, SOCK_SEQPACKET, NETLINK_ROUTE),
-              SyscallFailsWithErrno(ESOCKTNOSUPPORT));
-  EXPECT_THAT(socket(AF_NETLINK, SOCK_RDM, NETLINK_ROUTE),
-              SyscallFailsWithErrno(ESOCKTNOSUPPORT));
-  EXPECT_THAT(socket(AF_NETLINK, SOCK_DCCP, NETLINK_ROUTE),
-              SyscallFailsWithErrno(ESOCKTNOSUPPORT));
-  EXPECT_THAT(socket(AF_NETLINK, SOCK_PACKET, NETLINK_ROUTE),
-              SyscallFailsWithErrno(ESOCKTNOSUPPORT));
-
-  int fd;
-  EXPECT_THAT(fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE),
-              SyscallSucceeds());
-  EXPECT_THAT(close(fd), SyscallSucceeds());
-
-  EXPECT_THAT(fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE),
-              SyscallSucceeds());
-  EXPECT_THAT(close(fd), SyscallSucceeds());
-}
-
-TEST(NetlinkRouteTest, AutomaticPort) {
-  FileDescriptor fd =
-      ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE));
-
-  struct sockaddr_nl addr = {};
-  addr.nl_family = AF_NETLINK;
-
-  EXPECT_THAT(
-      bind(fd.get(), reinterpret_cast<struct sockaddr*>(&addr), sizeof(addr)),
-      SyscallSucceeds());
-
-  socklen_t addrlen = sizeof(addr);
-  EXPECT_THAT(getsockname(fd.get(), reinterpret_cast<struct sockaddr*>(&addr),
-                          &addrlen),
-              SyscallSucceeds());
-  EXPECT_EQ(addrlen, sizeof(addr));
-  // This is the only netlink socket in the process, so it should get the PID as
-  // the port id.
-  //
-  // N.B. Another process could theoretically have explicitly reserved our pid
-  // as a port ID, but that is very unlikely.
-  EXPECT_EQ(addr.nl_pid, getpid());
-}
-
-// Calling connect automatically binds to an automatic port.
-TEST(NetlinkRouteTest, ConnectBinds) {
-  FileDescriptor fd =
-      ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE));
-
-  struct sockaddr_nl addr = {};
-  addr.nl_family = AF_NETLINK;
-
-  EXPECT_THAT(connect(fd.get(), reinterpret_cast<struct sockaddr*>(&addr),
-                      sizeof(addr)),
-              SyscallSucceeds());
-
-  socklen_t addrlen = sizeof(addr);
-  EXPECT_THAT(getsockname(fd.get(), reinterpret_cast<struct sockaddr*>(&addr),
-                          &addrlen),
-              SyscallSucceeds());
-  EXPECT_EQ(addrlen, sizeof(addr));
-
-  // Each test is running in a pid namespace, so another process can explicitly
-  // reserve our pid as a port ID. In this case, a negative portid value will be
-  // set.
-  if (static_cast<pid_t>(addr.nl_pid) > 0) {
-    EXPECT_EQ(addr.nl_pid, getpid());
-  }
-
-  memset(&addr, 0, sizeof(addr));
-  addr.nl_family = AF_NETLINK;
-
-  // Connecting again is allowed, but keeps the same port.
-  EXPECT_THAT(connect(fd.get(), reinterpret_cast<struct sockaddr*>(&addr),
-                      sizeof(addr)),
-              SyscallSucceeds());
-
-  addrlen = sizeof(addr);
-  EXPECT_THAT(getsockname(fd.get(), reinterpret_cast<struct sockaddr*>(&addr),
-                          &addrlen),
-              SyscallSucceeds());
-  EXPECT_EQ(addrlen, sizeof(addr));
-  EXPECT_EQ(addr.nl_pid, getpid());
-}
-
-TEST(NetlinkRouteTest, GetPeerName) {
-  FileDescriptor fd =
-      ASSERT_NO_ERRNO_AND_VALUE(Socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE));
-
-  struct sockaddr_nl addr = {};
-  socklen_t addrlen = sizeof(addr);
-
-  EXPECT_THAT(getpeername(fd.get(), reinterpret_cast<struct sockaddr*>(&addr),
-                          &addrlen),
-              SyscallSucceeds());
-
-  EXPECT_EQ(addrlen, sizeof(addr));
-  EXPECT_EQ(addr.nl_family, AF_NETLINK);
-  // Peer is the kernel if we didn't connect elsewhere.
-  EXPECT_EQ(addr.nl_pid, 0);
-}
-
-// Parameters for GetSockOpt test. They are:
+// Parameters for SockOptTest. They are:
 // 0: Socket option to query.
 // 1: A predicate to run on the returned sockopt value. Should return true if
 //    the value is considered ok.
@@ -219,7 +114,8 @@ void CheckGetLinkResponse(const struct nlmsghdr* hdr, int seq, int port) {
 }
 
 TEST(NetlinkRouteTest, GetLinkDump) {
-  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket());
+  FileDescriptor fd =
+      ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket(NETLINK_ROUTE));
   uint32_t port = ASSERT_NO_ERRNO_AND_VALUE(NetlinkPortID(fd.get()));
 
   struct request {
@@ -260,7 +156,8 @@ TEST(NetlinkRouteTest, GetLinkDump) {
 }
 
 TEST(NetlinkRouteTest, MsgHdrMsgUnsuppType) {
-  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket());
+  FileDescriptor fd =
+      ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket(NETLINK_ROUTE));
 
   struct request {
     struct nlmsghdr hdr;
@@ -293,7 +190,8 @@ TEST(NetlinkRouteTest, MsgHdrMsgUnsuppType) {
 }
 
 TEST(NetlinkRouteTest, MsgHdrMsgTrunc) {
-  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket());
+  FileDescriptor fd =
+      ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket(NETLINK_ROUTE));
 
   struct request {
     struct nlmsghdr hdr;
@@ -332,7 +230,8 @@ TEST(NetlinkRouteTest, MsgHdrMsgTrunc) {
 }
 
 TEST(NetlinkRouteTest, MsgTruncMsgHdrMsgTrunc) {
-  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket());
+  FileDescriptor fd =
+      ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket(NETLINK_ROUTE));
 
   struct request {
     struct nlmsghdr hdr;
@@ -373,7 +272,8 @@ TEST(NetlinkRouteTest, MsgTruncMsgHdrMsgTrunc) {
 }
 
 TEST(NetlinkRouteTest, ControlMessageIgnored) {
-  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket());
+  FileDescriptor fd =
+      ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket(NETLINK_ROUTE));
   uint32_t port = ASSERT_NO_ERRNO_AND_VALUE(NetlinkPortID(fd.get()));
 
   struct request {
@@ -408,7 +308,8 @@ TEST(NetlinkRouteTest, ControlMessageIgnored) {
 }
 
 TEST(NetlinkRouteTest, GetAddrDump) {
-  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket());
+  FileDescriptor fd =
+      ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket(NETLINK_ROUTE));
   uint32_t port = ASSERT_NO_ERRNO_AND_VALUE(NetlinkPortID(fd.get()));
 
   struct request {
@@ -468,7 +369,8 @@ TEST(NetlinkRouteTest, LookupAll) {
 
 // GetRouteDump tests a RTM_GETROUTE + NLM_F_DUMP request.
 TEST(NetlinkRouteTest, GetRouteDump) {
-  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket());
+  FileDescriptor fd =
+      ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket(NETLINK_ROUTE));
   uint32_t port = ASSERT_NO_ERRNO_AND_VALUE(NetlinkPortID(fd.get()));
 
   struct request {
@@ -544,7 +446,8 @@ TEST(NetlinkRouteTest, GetRouteDump) {
 // buffer. MSG_TRUNC with a zero length buffer should consume subsequent
 // messages off the socket.
 TEST(NetlinkRouteTest, RecvmsgTrunc) {
-  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket());
+  FileDescriptor fd =
+      ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket(NETLINK_ROUTE));
 
   struct request {
     struct nlmsghdr hdr;
@@ -620,7 +523,8 @@ TEST(NetlinkRouteTest, RecvmsgTrunc) {
 // it, so a properly sized buffer can be allocated to store the message. This
 // test tests that scenario.
 TEST(NetlinkRouteTest, RecvmsgTruncPeek) {
-  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket());
+  FileDescriptor fd =
+      ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket(NETLINK_ROUTE));
 
   struct request {
     struct nlmsghdr hdr;
@@ -695,7 +599,8 @@ TEST(NetlinkRouteTest, RecvmsgTruncPeek) {
 
 // No SCM_CREDENTIALS are received without SO_PASSCRED set.
 TEST(NetlinkRouteTest, NoPasscredNoCreds) {
-  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket());
+  FileDescriptor fd =
+      ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket(NETLINK_ROUTE));
 
   ASSERT_THAT(setsockopt(fd.get(), SOL_SOCKET, SO_PASSCRED, &kSockOptOff,
                          sizeof(kSockOptOff)),
@@ -742,7 +647,8 @@ TEST(NetlinkRouteTest, NoPasscredNoCreds) {
 
 // SCM_CREDENTIALS are received with SO_PASSCRED set.
 TEST(NetlinkRouteTest, PasscredCreds) {
-  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket());
+  FileDescriptor fd =
+      ASSERT_NO_ERRNO_AND_VALUE(NetlinkBoundSocket(NETLINK_ROUTE));
 
   ASSERT_THAT(setsockopt(fd.get(), SOL_SOCKET, SO_PASSCRED, &kSockOptOn,
                          sizeof(kSockOptOn)),