socket: add support for TCP sockets

TCP sockets will be needed for NTS key establishment.

socket.c

@@ -168,6 +168,19 @@ check_socket_flag(int sock_flag, int fd_flag, int fs_flag)
 
 /* ================================================== */
 
+static int
+set_socket_nonblock(int sock_fd)
+{
+  if (fcntl(sock_fd, F_SETFL, O_NONBLOCK)) {
+    DEBUG_LOG("Could not set O_NONBLOCK : %s", strerror(errno));
+    return 0;
+  }
+
+  return 1;
+}
+
+/* ================================================== */
+
 static int
 open_socket(int domain, int type, int flags)
 {
@@ -196,8 +209,7 @@ open_socket(int domain, int type, int flags)
 #ifdef SOCK_NONBLOCK
       (socket_flags & SOCK_NONBLOCK) == 0 &&
 #endif
-      fcntl(sock_fd, F_SETFL, O_NONBLOCK)) {
+      !set_socket_nonblock(sock_fd)) {
-    DEBUG_LOG("Could not set O_NONBLOCK : %s", strerror(errno));
     close(sock_fd);
     return INVALID_SOCK_FD;
   }
@@ -318,7 +330,7 @@ connect_ip_address(int sock_fd, IPSockAddr *addr)
   if (saddr_len == 0)
     return 0;
 
-  if (connect(sock_fd, &saddr.sa, saddr_len) < 0) {
+  if (connect(sock_fd, &saddr.sa, saddr_len) < 0 && errno != EINPROGRESS) {
     DEBUG_LOG("Could not connect socket to %s : %s",
               UTI_IPSockAddrToString(addr), strerror(errno));
     return 0;
@@ -377,8 +389,9 @@ open_ip_socket(IPSockAddr *remote_addr, IPSockAddr *local_addr, int type, int fl
     goto error;
 
   if (remote_addr || local_addr)
-    DEBUG_LOG("Opened %s socket fd=%d%s%s%s%s",
+    DEBUG_LOG("Opened %s%s socket fd=%d%s%s%s%s",
-              family == IPADDR_INET4 ? "IPv4" : "IPv6",
+              type == SOCK_DGRAM ? "UDP" : type == SOCK_STREAM ? "TCP" : "?",
+              family == IPADDR_INET4 ? "v4" : "v6",
               sock_fd,
               remote_addr ? " remote=" : "",
               remote_addr ? UTI_IPSockAddrToString(remote_addr) : "",
@@ -508,11 +521,8 @@ handle_recv_error(int sock_fd, int flags)
      be for a socket error.  Clear the error to avoid a busy loop. */
   if (flags & SCK_FLAG_MSG_ERRQUEUE) {
     int error = 0;
-    socklen_t len = sizeof (error);
 
-    if (getsockopt(sock_fd, SOL_SOCKET, SO_ERROR, &error, &len))
+    if (SCK_GetIntOption(sock_fd, SOL_SOCKET, SO_ERROR, &error))
-      DEBUG_LOG("Could not get SO_ERROR");
-    if (error)
       errno = error;
   }
 #endif
@@ -1077,6 +1087,14 @@ SCK_OpenUdpSocket(IPSockAddr *remote_addr, IPSockAddr *local_addr, int flags)
 
 /* ================================================== */
 
+int
+SCK_OpenTcpSocket(IPSockAddr *remote_addr, IPSockAddr *local_addr, int flags)
+{
+  return open_ip_socket(remote_addr, local_addr, SOCK_STREAM, flags);
+}
+
+/* ================================================== */
+
 int
 SCK_OpenUnixDatagramSocket(const char *remote_addr, const char *local_addr, int flags)
 {
@@ -1107,6 +1125,22 @@ SCK_SetIntOption(int sock_fd, int level, int name, int value)
 
 /* ================================================== */
 
+int
+SCK_GetIntOption(int sock_fd, int level, int name, int *value)
+{
+  socklen_t len = sizeof (*value);
+
+  if (getsockopt(sock_fd, level, name, value, &len) < 0) {
+    DEBUG_LOG("getsockopt() failed fd=%d level=%d name=%d : %s",
+              sock_fd, level, name, strerror(errno));
+    return 0;
+  }
+
+  return 1;
+}
+
+/* ================================================== */
+
 int
 SCK_EnableKernelRxTimestamping(int sock_fd)
 {
@@ -1124,6 +1158,57 @@ SCK_EnableKernelRxTimestamping(int sock_fd)
 
 /* ================================================== */
 
+int
+SCK_ListenOnSocket(int sock_fd, int backlog)
+{
+  if (listen(sock_fd, backlog) < 0) {
+    DEBUG_LOG("listen() failed : %s", strerror(errno));
+    return 0;
+  }
+
+  return 1;
+}
+
+/* ================================================== */
+
+int
+SCK_AcceptConnection(int sock_fd, IPSockAddr *remote_addr)
+{
+  union sockaddr_all saddr;
+  socklen_t saddr_len = sizeof (saddr);
+  int conn_fd;
+
+  conn_fd = accept(sock_fd, &saddr.sa, &saddr_len);
+  if (conn_fd < 0) {
+    DEBUG_LOG("accept() failed : %s", strerror(errno));
+    return INVALID_SOCK_FD;
+  }
+
+  if (!UTI_FdSetCloexec(conn_fd) || !set_socket_nonblock(conn_fd)) {
+    close(conn_fd);
+    return INVALID_SOCK_FD;
+  }
+
+  SCK_SockaddrToIPSockAddr(&saddr.sa, saddr_len, remote_addr);
+
+  return conn_fd;
+}
+
+/* ================================================== */
+
+int
+SCK_ShutdownConnection(int sock_fd)
+{
+  if (shutdown(sock_fd, SHUT_RDWR) < 0) {
+    DEBUG_LOG("shutdown() failed : %s", strerror(errno));
+    return 0;
+  }
+
+  return 1;
+}
+
+/* ================================================== */
+
 int
 SCK_Receive(int sock_fd, void *buffer, unsigned int length, int flags)
 {

socket.h

@@ -95,11 +95,18 @@ extern int SCK_OpenUnixDatagramSocket(const char *remote_addr, const char *local
 extern int SCK_OpenUnixStreamSocket(const char *remote_addr, const char *local_addr,
                                     int flags);
 
-/* Set a socket option */
+/* Set and get a socket option of int size */
-extern int SCK_SetIntOption(int sock_fd, int level, int option, int value);
+extern int SCK_SetIntOption(int sock_fd, int level, int name, int value);
+extern int SCK_GetIntOption(int sock_fd, int level, int name, int *value);
+
 /* Enable RX timestamping socket option */
 extern int SCK_EnableKernelRxTimestamping(int sock_fd);
 
+/* Operate on a stream socket - listen()/accept()/shutdown() wrappers */
+extern int SCK_ListenOnSocket(int sock_fd, int backlog);
+extern int SCK_AcceptConnection(int sock_fd, IPSockAddr *remote_addr);
+extern int SCK_ShutdownConnection(int sock_fd);
+
 /* Receive and send data on connected sockets - recv()/send() wrappers */
 extern int SCK_Receive(int sock_fd, void *buffer, unsigned int length, int flags);
 extern int SCK_Send(int sock_fd, void *buffer, unsigned int length, int flags);

sys_linux.c

@@ -496,9 +496,10 @@ SYS_Linux_EnableSystemCallFilter(int level)
     SCMP_SYS(stat), SCMP_SYS(stat64), SCMP_SYS(statfs), SCMP_SYS(statfs64),
     SCMP_SYS(unlink), SCMP_SYS(unlinkat),
     /* Socket */
-    SCMP_SYS(bind), SCMP_SYS(connect), SCMP_SYS(getsockname), SCMP_SYS(getsockopt),
+    SCMP_SYS(accept), SCMP_SYS(bind), SCMP_SYS(connect), SCMP_SYS(getsockname),
-    SCMP_SYS(recv), SCMP_SYS(recvfrom), SCMP_SYS(recvmmsg), SCMP_SYS(recvmsg),
+    SCMP_SYS(getsockopt), SCMP_SYS(recv), SCMP_SYS(recvfrom),
-    SCMP_SYS(send), SCMP_SYS(sendmmsg), SCMP_SYS(sendmsg), SCMP_SYS(sendto),
+    SCMP_SYS(recvmmsg), SCMP_SYS(recvmsg), SCMP_SYS(send), SCMP_SYS(sendmmsg),
+    SCMP_SYS(sendmsg), SCMP_SYS(sendto), SCMP_SYS(shutdown),
     /* TODO: check socketcall arguments */
     SCMP_SYS(socketcall),
     /* General I/O */