Receives bytes for a socket from any source.
    Format
      #include  <types.h>
      #include  <socket.h>
      int recvfrom  ( int s, char *buf, int len, int flags,
                    struct sockaddr *from, int *fromlen)  ;
                    (_DECC_V4_SOURCE)
      ssize_t recvfrom  ( int s, void *buf, size_t len, int flags,
                        struct sockaddr *from, size_t *fromlen)  ;
                        (not_DECC_V4_SOURCE)