[posix] open netif fds with O_NONBLOCK in a compatible way (#4804)

src/posix/platform/misc.cpp

@@ -83,7 +83,7 @@ otPlatMcuPowerState otPlatGetMcuPowerState(otInstance *aInstance)
     return gPlatMcuPowerState;
 }
 
-int SocketWithCloseExec(int aDomain, int aType, int aProtocol)
+int SocketWithCloseExec(int aDomain, int aType, int aProtocol, SocketBlockOption aBlockOption)
 {
     int rval = 0;
     int fd   = -1;
@@ -92,13 +92,15 @@ int SocketWithCloseExec(int aDomain, int aType, int aProtocol)
     VerifyOrExit((fd = socket(aDomain, aType, aProtocol)) != -1, perror("socket(SOCK_CLOEXEC)"));
 
     VerifyOrExit((rval = fcntl(fd, F_GETFD, 0)) != -1, perror("fcntl(F_GETFD)"));
-    VerifyOrExit((rval = fcntl(fd, F_SETFD, rval | FD_CLOEXEC)) != -1, perror("fcntl(F_SETFD)"));
+    rval |= aBlockOption == kSocketNonBlock ? O_NONBLOCK | FD_CLOEXEC : FD_CLOEXEC;
+    VerifyOrExit((rval = fcntl(fd, F_SETFD, rval)) != -1, perror("fcntl(F_SETFD)"));
 #else
-    VerifyOrExit((fd = socket(aDomain, aType | SOCK_CLOEXEC, aProtocol)) != -1, perror("socket(SOCK_CLOEXEC)"));
+    aType |= aBlockOption == kSocketNonBlock ? SOCK_CLOEXEC | SOCK_NONBLOCK : SOCK_CLOEXEC;
+    VerifyOrExit((fd = socket(aDomain, aType, aProtocol)) != -1, perror("socket(SOCK_CLOEXEC)"));
 #endif
 
 exit:
-    if (rval == -1 && fd != -1)
+    if (rval == -1)
     {
         VerifyOrDie(close(fd) == 0, OT_EXIT_ERROR_ERRNO);
         fd = -1;

src/posix/platform/netif.cpp

@@ -447,7 +447,7 @@ static void mldListenerInit(void)
 {
     struct ipv6_mreq mreq6;
 
-    sMLDMonitorFd          = SocketWithCloseExec(AF_INET6, SOCK_RAW | SOCK_NONBLOCK, IPPROTO_ICMPV6);
+    sMLDMonitorFd          = SocketWithCloseExec(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6, kSocketNonBlock);
     mreq6.ipv6mr_interface = sTunIndex;
     memcpy(&mreq6.ipv6mr_multiaddr, kMLDv2MulticastAddress.mFields.m8, sizeof(kMLDv2MulticastAddress.mFields.m8));
 
@@ -559,7 +559,7 @@ void platformNetifInit(otInstance *aInstance, const char *aInterfaceName)
 {
     struct ifreq ifr;
 
-    sIpFd = SocketWithCloseExec(AF_INET6, SOCK_DGRAM, IPPROTO_IP);
+    sIpFd = SocketWithCloseExec(AF_INET6, SOCK_DGRAM, IPPROTO_IP, kSocketNonBlock);
     VerifyOrDie(sIpFd >= 0, OT_EXIT_ERROR_ERRNO);
 
     sNetlinkFd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
@@ -576,7 +576,7 @@ void platformNetifInit(otInstance *aInstance, const char *aInterfaceName)
         VerifyOrDie(bind(sNetlinkFd, reinterpret_cast<struct sockaddr *>(&sa), sizeof(sa)) == 0, OT_EXIT_ERROR_ERRNO);
     }
 
-    sTunFd = open(OPENTHREAD_POSIX_TUN_DEVICE, O_RDWR | O_CLOEXEC);
+    sTunFd = open(OPENTHREAD_POSIX_TUN_DEVICE, O_RDWR | O_CLOEXEC | O_NONBLOCK);
     VerifyOrDie(sTunFd > 0, OT_EXIT_ERROR_ERRNO);
 
     memset(&ifr, 0, sizeof(ifr));

src/posix/platform/platform-posix.h

@@ -428,19 +428,26 @@ void platformUdpProcess(otInstance *aInstance, const fd_set *aReadSet);
  */
 void platformUdpUpdateFdSet(otInstance *aInstance, fd_set *aReadFdSet, int *aMaxFd);
 
+enum SocketBlockOption
+{
+    kSocketBlock,
+    kSocketNonBlock,
+};
+
 /**
  * This function creates a socket with SOCK_CLOEXEC flag set.
  *
- * @param[in]   aDomain     The communication domain.
- * @param[in]   aType       The semantics of communication.
- * @param[in]   aProtocol   The protocol to use.
+ * @param[in]   aDomain       The communication domain.
+ * @param[in]   aType         The semantics of communication.
+ * @param[in]   aProtocol     The protocol to use.
+ * @param[in]   aBlockOption  Whether to add nonblock flags.
  *
  * @returns The file descriptor of the created socket.
  *
  * @retval  -1  Failed to create socket.
  *
  */
-int SocketWithCloseExec(int aDomain, int aType, int aProtocol);
+int SocketWithCloseExec(int aDomain, int aType, int aProtocol, SocketBlockOption aBlockOption);
 
 #ifdef __cplusplus
 }

src/posix/platform/uart.cpp

@@ -69,7 +69,7 @@ otError otPlatUartEnable(void)
     // This allows implementing pseudo reset.
     VerifyOrExit(sUartSocket == -1, OT_NOOP);
 
-    sUartSocket = SocketWithCloseExec(AF_UNIX, SOCK_STREAM, 0);
+    sUartSocket = SocketWithCloseExec(AF_UNIX, SOCK_STREAM, 0, kSocketNonBlock);
 
     if (sUartSocket == -1)
     {

src/posix/platform/udp.cpp

@@ -219,7 +219,7 @@ otError otPlatUdpSocket(otUdpSocket *aUdpSocket)
 
     assert(aUdpSocket->mHandle == NULL);
 
-    fd = SocketWithCloseExec(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
+    fd = SocketWithCloseExec(AF_INET6, SOCK_DGRAM, IPPROTO_UDP, kSocketNonBlock);
     VerifyOrExit(fd >= 0, error = OT_ERROR_FAILED);
 
     aUdpSocket->mHandle = FdToHandle(fd);

src/posix/platform/virtual_time.cpp

@@ -87,7 +87,7 @@ void virtualTimeInit(void)
     sockaddr.sin_port        = htons(kBasePort + sPortOffset + sNodeId);
     sockaddr.sin_addr.s_addr = INADDR_ANY;
 
-    sSockFd = SocketWithCloseExec(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+    sSockFd = SocketWithCloseExec(AF_INET, SOCK_DGRAM, IPPROTO_UDP, kSocketBlock);
 
     if (sSockFd == -1)
     {