Functions
err_t	udp_send (struct udp_pcb pcb, struct pbuf p)

err_t	udp_sendto (struct udp_pcb pcb, struct pbuf p, const ip_addr_t *dst_ip, u16_t dst_port)

err_t	udp_sendto_if (struct udp_pcb pcb, struct pbuf p, const ip_addr_t dst_ip, u16_t dst_port, struct netif netif)

err_t	udp_sendto_if_src (struct udp_pcb pcb, struct pbuf p, const ip_addr_t dst_ip, u16_t dst_port, struct netif netif, const ip_addr_t *src_ip)

err_t	udp_bind (struct udp_pcb pcb, const ip_addr_t ipaddr, u16_t port)

void	udp_bind_netif (struct udp_pcb pcb, const struct netif netif)

err_t	udp_connect (struct udp_pcb pcb, const ip_addr_t ipaddr, u16_t port)

void	udp_disconnect (struct udp_pcb *pcb)

void	udp_recv (struct udp_pcb pcb, udp_recv_fn recv, void recv_arg)

void	udp_remove (struct udp_pcb *pcb)

struct udp_pcb *	udp_new (void)

struct udp_pcb *	udp_new_ip_type (u8_t type)

Detailed Description

User Datagram Protocol module

See also: APIs

Function Documentation

◆ udp_bind()

err_t udp_bind	(	struct udp_pcb *	pcb,
		const ip_addr_t *	ipaddr,
		u16_t	port
	)

Bind an UDP PCB.

Parameters

pcb	UDP PCB to be bound with a local address ipaddr and port.
ipaddr	local IP address to bind with. Use IP_ANY_TYPE to bind to all local interfaces.
port	local UDP port to bind with. Use 0 to automatically bind to a random port between UDP_LOCAL_PORT_RANGE_START and UDP_LOCAL_PORT_RANGE_END.

ipaddr & port are expected to be in the same byte order as in the pcb.

Returns

lwIP error code.

ERR_OK. Successful. No error occurred.
ERR_USE. The specified ipaddr and port are already bound to by another UDP PCB.

See also: udp_disconnect()

◆ udp_bind_netif()

void udp_bind_netif	(	struct udp_pcb *	pcb,
		const struct netif *	netif
	)

Bind an UDP PCB to a specific netif. After calling this function, all packets received via this PCB are guaranteed to have come in via the specified netif, and all outgoing packets will go out via the specified netif.

Parameters

pcb	UDP PCB to be bound.
netif	netif to bind udp pcb to. Can be NULL.

See also: udp_disconnect()

◆ udp_connect()

err_t udp_connect	(	struct udp_pcb *	pcb,
		const ip_addr_t *	ipaddr,
		u16_t	port
	)

Sets the remote end of the pcb. This function does not generate any network traffic, but only sets the remote address of the pcb.

Parameters

pcb	UDP PCB to be connected with remote address ipaddr and port.
ipaddr	remote IP address to connect with.
port	remote UDP port to connect with.

Returns: lwIP error code

ipaddr & port are expected to be in the same byte order as in the pcb.

The udp pcb is bound to a random local port if not already bound.

See also: udp_disconnect()

◆ udp_disconnect()

void udp_disconnect ( struct udp_pcb * pcb )

Remove the remote end of the pcb. This function does not generate any network traffic, but only removes the remote address of the pcb.

Parameters

pcb	the udp pcb to disconnect.

◆ udp_new()

struct udp_pcb* udp_new ( void )

Creates a new UDP pcb which can be used for UDP communication. The pcb is not active until it has either been bound to a local address or connected to a remote address.

Returns: The UDP PCB which was created. NULL if the PCB data structure could not be allocated.

See also: udp_remove()

◆ udp_new_ip_type()

struct udp_pcb* udp_new_ip_type ( u8_t type )

Create a UDP PCB for specific IP type. The pcb is not active until it has either been bound to a local address or connected to a remote address.

Parameters

type	IP address type, see lwip_ip_addr_type definitions. If you want to listen to IPv4 and IPv6 (dual-stack) packets, supply IPADDR_TYPE_ANY as argument and bind to IP_ANY_TYPE.

Returns: The UDP PCB which was created. NULL if the PCB data structure could not be allocated.

See also: udp_remove()

◆ udp_recv()

void udp_recv	(	struct udp_pcb *	pcb,
		udp_recv_fn	recv,
		void *	recv_arg
	)

Set a receive callback for a UDP PCB. This callback will be called when receiving a datagram for the pcb.

Parameters

pcb	the pcb for which to set the recv callback
recv	function pointer of the callback function
recv_arg	additional argument to pass to the callback function

◆ udp_remove()

void udp_remove ( struct udp_pcb * pcb )

Removes and deallocates the pcb.

Parameters

pcb	UDP PCB to be removed. The PCB is removed from the list of UDP PCB's and the data structure is freed from memory.

See also: udp_new()

◆ udp_send()

err_t udp_send	(	struct udp_pcb *	pcb,
		struct pbuf *	p
	)

Sends the pbuf p using UDP. The pbuf is not deallocated.

Parameters

pcb	UDP PCB used to send the data.
p	chain of pbuf's to be sent.

The datagram will be sent to the current remote_ip & remote_port stored in pcb. If the pcb is not bound to a port, it will automatically be bound to a random port.

Returns

lwIP error code.

ERR_OK. Successful. No error occurred.
ERR_MEM. Out of memory.
ERR_RTE. Could not find route to destination address.
ERR_VAL. No PCB or PCB is dual-stack
More errors could be returned by lower protocol layers.

See also: udp_disconnect() udp_sendto()

◆ udp_sendto()

err_t udp_sendto	(	struct udp_pcb *	pcb,
		struct pbuf *	p,
		const ip_addr_t *	dst_ip,
		u16_t	dst_port
	)

Send data to a specified address using UDP.

Parameters

pcb	UDP PCB used to send the data.
p	chain of pbuf's to be sent.
dst_ip	Destination IP address.
dst_port	Destination UDP port.

dst_ip & dst_port are expected to be in the same byte order as in the pcb.

If the PCB already has a remote address association, it will be restored after the data is sent.

Returns: lwIP error code (

See also: udp_send for possible error codes); udp_disconnect() udp_send()

◆ udp_sendto_if()

err_t udp_sendto_if	(	struct udp_pcb *	pcb,
		struct pbuf *	p,
		const ip_addr_t *	dst_ip,
		u16_t	dst_port,
		struct netif *	netif
	)

Send data to a specified address using UDP. The netif used for sending can be specified.

This function exists mainly for DHCP, to be able to send UDP packets on a netif that is still down.

Parameters

pcb	UDP PCB used to send the data.
p	chain of pbuf's to be sent.
dst_ip	Destination IP address.
dst_port	Destination UDP port.
netif	the netif used for sending.

dst_ip & dst_port are expected to be in the same byte order as in the pcb.

Returns: lwIP error code (

See also: udp_send for possible error codes); udp_disconnect() udp_send()

◆ udp_sendto_if_src()

err_t udp_sendto_if_src	(	struct udp_pcb *	pcb,
		struct pbuf *	p,
		const ip_addr_t *	dst_ip,
		u16_t	dst_port,
		struct netif *	netif,
		const ip_addr_t *	src_ip
	)

Same as udp_sendto_if, but with source address

Functions

Detailed Description

Function Documentation

◆ udp_bind()

◆ udp_bind_netif()

◆ udp_connect()

◆ udp_disconnect()

◆ udp_new()

◆ udp_new_ip_type()

◆ udp_recv()

◆ udp_remove()

◆ udp_send()

◆ udp_sendto()

◆ udp_sendto_if()

◆ udp_sendto_if_src()