net/socket: replace net_lock with conn_lock

dup2 and setsockopt can use the lock in conn to protect resources,
the lock in accept is originally used to protect the connection status.
however, only the send, recv, netpoll, and connect processes will
check this flag. only when the interface returns will the corresponding
conn structure be exposed to the caller, and then the above operations
can be performed. Therefore, this net_lock is not necessary.

Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>

net/socket/accept.c

@@ -147,7 +147,6 @@ int psock_accept(FAR struct socket *psock, FAR struct sockaddr *addr,
       return -EOPNOTSUPP;
     }
 
-  net_lock();
   ret = psock->s_sockif->si_accept(psock, addr, addrlen, newsock, flags);
   if (ret >= 0)
     {
@@ -166,6 +165,5 @@ int psock_accept(FAR struct socket *psock, FAR struct sockaddr *addr,
       nerr("ERROR: si_accept failed: %d\n", ret);
     }
 
-  net_unlock();
   return ret;
 }

net/socket/net_dup2.c

@@ -39,6 +39,7 @@
 #include "inet/inet.h"
 #include "tcp/tcp.h"
 #include "socket/socket.h"
+#include "utils/utils.h"
 
 /****************************************************************************
  * Public Functions
@@ -65,7 +66,7 @@ int psock_dup2(FAR struct socket *psock1, FAR struct socket *psock2)
 {
   /* Parts of this operation need to be atomic */
 
-  net_lock();
+  conn_lock(psock1->s_conn);
 
   /* Duplicate the relevant socket state (zeroing everything else) */
 
@@ -84,7 +85,7 @@ int psock_dup2(FAR struct socket *psock1, FAR struct socket *psock2)
               psock2->s_sockif->si_addref != NULL);
   psock2->s_sockif->si_addref(psock2);
 
-  net_unlock();
+  conn_unlock(psock1->s_conn);
 
   return OK;
 }

net/socket/setsockopt.c

@@ -161,7 +161,7 @@ static int psock_socketlevel_option(FAR struct socket *psock, int option,
            * options.
            */
 
-           net_lock();
+          conn_lock(conn);
 
           /* Set or clear the option bit */
 
@@ -174,7 +174,7 @@ static int psock_socketlevel_option(FAR struct socket *psock, int option,
               _SO_CLROPT(conn->s_options, option);
             }
 
-          net_unlock();
+          conn_unlock(conn);
         }
         break;