NetSock_RxData() / recv() (TCP) NetSock_RxDataFrom() / recvfrom() (UDP)
Copy up to a specified number of bytes received from a remote socket into an application memory buffer.
Files
net_sock.h/net_sock.c
net_bsd.h/net_bsd.c
Prototypes
Arguments
sock_id
This is the socket ID returned by NetSock_Open()/socket() when the socket was created or by NetSock_Accept()/accept() when a connection was accepted.
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Flag to select receive options; bit-field flags logically OR’d:
NET_SOCK_FLAG_NONE/0
No socket flags selected
NET_SOCK_FLAG_RX_DATA_PEEK/
MSG_PEEK
Receive socket data without consuming it
NET_SOCK_FLAG_RX_NO_BLOCK/
MSG_DONTWAIT
Receive socket data without blocking
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In most cases, this flag would be set to NET_SOCK_FLAG_NONE/0.
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Pointer to variable that will receive the return error code from this function:
NET_SOCK_ERR_NONE
NET_SOCK_ERR_NULL_PTR
NET_SOCK_ERR_NULL_SIZE
NET_SOCK_ERR_NOT_USED
NET_SOCK_ERR_CLOSED
NET_SOCK_ERR_INVALID_SOCK
NET_SOCK_ERR_INVALID_FAMILY
NET_SOCK_ERR_INVALID_PROTOCOL
NET_SOCK_ERR_INVALID_TYPE
NET_SOCK_ERR_INVALID_STATE
NET_SOCK_ERR_INVALID_OP
NET_SOCK_ERR_INVALID_FLAG
NET_SOCK_ERR_INVALID_ADDR_LEN
NET_SOCK_ERR_INVALID_DATA_SIZE
NET_SOCK_ERR_CONN_FAIL
NET_SOCK_ERR_FAULT
NET_SOCK_ERR_RX_Q_EMPTY
NET_SOCK_ERR_RX_Q_CLOSED
NET_ERR_RX
NET_CONN_ERR_NULL_PTR
NET_CONN_ERR_NOT_USED
NET_CONN_ERR_INVALID_CONN
NET_CONN_ERR_INVALID_ADDR_LEN
NET_CONN_ERR_ADDR_NOT_USED
NET_ERR_INIT_INCOMPLETE
NET_OS_ERR_LOCK
Returned Value
Positive number of bytes received, if successful;
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NET_SOCK_BSD_ERR_RX/-1, otherwise.
Blocking vs Non-Blocking
The default setting for µC/TCP-IP is blocking. However, this setting can be changed at compile time by setting the NET_SOCK_CFG_BLOCK_SEL (see section D-15-3) to one of the following values:
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The current version of µC/TCP-IP selects blocking or non-blocking at compile time for all sockets. A future version may allow the selection of blocking or non-blocking at the individual socket level. However, each socket receive call can pass the NET_SOCK_FLAG_RX_NO_BLOCK/MSG_DONTWAIT flag to disable blocking on that call.
Required Configuration
NetSock_RxData()/NetSock_RxDataFrom() is available only if NET_CFG_TRANSPORT_LAYER_SEL is configured for TCP (see section D-12-1) and/or NET_UDP_CFG_APP_API_SEL is configured for sockets (see section D-13-1).
In addition, recv()/recvfrom() is available only if NET_BSD_CFG_API_EN is enabled (see section D-17-1).
Notes / Warnings
TCP sockets typically use NetSock_RxData()/recv(), whereas UDP sockets typically use NetSock_RxDataFrom()/recvfrom().
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