NetApp_SockOpen TCP-UDP

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Last updated: Dec 08, 2020 by WES Admin
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Open an application socket, with error handling. See section NetSock_Open() for more information.

Files

net_app.h/net_app.c

Prototype

          NET_SOCK_ID  NetApp_SockOpen (NET_SOCK_PROTOCOL_FAMILY   protocol_family,
                                        NET_SOCK_TYPE              sock_type,
                                        NET_SOCK_PROTOCOL          protocol,
                                        CPU_INT16U                 retry_max,
                                        CPU_INT32U                 time_dly_ms,
                                        NET_ERR                   *p_err);

Arguments

protocol_family

This field establishes the socket protocol family domain. Always use NET_SOCK_FAMILY_IP_V4/PF_INET or NET_SOCK_FAMILY_IP_V6/PF_INET6 for TCP/IP sockets.

sock_type

Socket type:

NET_SOCK_TYPE_DATAGRAM/PF_DGRAM for datagram sockets (i.e., UDP)

NET_SOCK_TYPE_STREAM/PF_STREAM for stream sockets (i.e., TCP)

NET_SOCK_TYPE_DATAGRAM sockets preserve message boundaries. Applications that exchange single request and response messages are examples of datagram communication.

NET_SOCK_TYPE_STREAM sockets provides a reliable byte-stream connection, where bytes are received from the remote application in the same order as they were sent. File transfer and terminal emulation are examples of applications that require this type of protocol.

protocol

Socket protocol:
NET_SOCK_PROTOCOL_UDP/IPPROTO_UDP for UDP
NET_SOCK_PROTOCOL_TCP/IPPROTO_TCP for TCP

0 for default-protocol:
UDP for NET_SOCK_TYPE_DATAGRAM/PF_DGRAM
TCP for NET_SOCK_TYPE_STREAM/PF_STREAM

retry_max

Maximum number of consecutive socket open retries.

time_dly_ms

Socket open delay value, in milliseconds.

p_err

Pointer to variable that will receive the error code from this function:

NET_APP_ERR_NONE
NET_APP_ERR_NONE_AVAIL
NET_APP_ERR_INVALID_ARG
NET_APP_ERR_FAULT

Returned Value

Socket descriptor/handle identifier of new socket, if no errors.

NET_SOCK_BSD_ERR_OPEN, otherwise.

Required Configuration

None.

Notes / Warnings

Some socket arguments and/or operations are validated only if validation code is enabled (see section Argument Check Configuration).

If a non-zero number of retries is requested (retry_max) then a non-zero time delay (time_dly_ms) should also be requested. Otherwise, all retries will likely fail immediately since no time will elapse to wait for and allow socket operations to successfully complete.