raw.c File Reference

Implementation of raw protocol PCBs for low-level handling of different types of protocols besides (or overriding) those already available in lwIP.

#include "lwip/opt.h"
#include "lwip/def.h"
#include "lwip/memp.h"
#include "lwip/ip_addr.h"
#include "lwip/netif.h"
#include "lwip/raw.h"
#include "lwip/stats.h"
#include "arch/perf.h"
#include <string.h>

Functions
err_t	raw_bind (struct raw_pcb *pcb, ip_addr_t *ipaddr)
	Bind a RAW PCB. More...
err_t	raw_connect (struct raw_pcb *pcb, ip_addr_t *ipaddr)
	Connect an RAW PCB. More...
u8_t	raw_input (struct pbuf *p, struct netif *inp)
	Determine if in incoming IP packet is covered by a RAW PCB and if so, pass it to a user-provided receive callback function. More...
struct raw_pcb *	raw_new (u8_t proto)
	Create a RAW PCB. More...
void	raw_recv (struct raw_pcb *pcb, raw_recv_fn recv, void *recv_arg)
	Set the callback function for received packets that match the raw PCB's protocol and binding. More...
void	raw_remove (struct raw_pcb *pcb)
	Remove an RAW PCB. More...
err_t	raw_send (struct raw_pcb *pcb, struct pbuf *p)
	Send the raw IP packet to the address given by raw_connect() More...
err_t	raw_sendto (struct raw_pcb *pcb, struct pbuf *p, ip_addr_t *ipaddr)
	Send the raw IP packet to the given address. More...

Variables
static struct raw_pcb *	raw_pcbs
	The list of RAW PCBs. More...

err_t raw_bind	(	struct raw_pcb *	pcb,
		ip_addr_t *	ipaddr
	)

Bind a RAW PCB.

Parameters

pcb	RAW PCB to be bound with a local address ipaddr.
ipaddr	local IP address to bind with. Use IP_ADDR_ANY to bind to all local interfaces.

Returns

lwIP error code.

• ERR_OK. Successful. No error occured.
• ERR_USE. The specified IP address is already bound to by another RAW PCB.

See Also

raw_disconnect()

References ERR_OK, and ip_addr_set.

Referenced by do_bind().

err_t raw_connect	(	struct raw_pcb *	pcb,
		ip_addr_t *	ipaddr
	)

Connect an RAW PCB.

This function is required by upper layers of lwip. Using the raw api you could use raw_sendto() instead

This will associate the RAW PCB with the remote address.

Parameters

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

Returns

lwIP error code

See Also

raw_disconnect() and raw_sendto()

References ERR_OK, and ip_addr_set.

Referenced by do_connect().

u8_t raw_input	(	struct pbuf *	p,
		struct netif *	inp
	)

Determine if in incoming IP packet is covered by a RAW PCB and if so, pass it to a user-provided receive callback function.

Given an incoming IP datagram (as a chain of pbufs) this function finds a corresponding RAW PCB and calls the corresponding receive callback function.

Parameters

p	pbuf to be demultiplexed to a RAW PCB.
inp	network interface on which the datagram was received.

Returns

- 1 if the packet has been eaten by a RAW PCB receive callback function. The caller MAY NOT not reference the packet any longer, and MAY NOT call pbuf_free().

- 0 if packet is not eaten (pbuf is still referenced by the caller).

References current_iphdr_dest, ip_addr_cmp, ip_addr_isany, ip_addr_isbroadcast, ip_current_src_addr, IPH_PROTO, iphdr, LWIP_UNUSED_ARG, raw_pcb::next, NULL, pbuf::payload, raw_pcb::protocol, raw_pcbs, raw_pcb::recv, raw_pcb::recv_arg, and SOF_BROADCAST.

Referenced by ip_input().

struct raw_pcb* raw_new

(

u8_t

proto

)

Create a RAW PCB.

Returns

The RAW PCB which was created. NULL if the PCB data structure could not be allocated.

Parameters

proto

the protocol number of the IPs payload (e.g. IP_PROTO_ICMP)

See Also

raw_remove()

References LWIP_DBG_TRACE, LWIP_DEBUGF, memp_malloc(), raw_pcb::next, NULL, raw_pcb::protocol, RAW_DEBUG, raw_pcbs, and RAW_TTL.

Referenced by pcb_new().

void raw_recv	(	struct raw_pcb *	pcb,
		raw_recv_fn	recv,
		void *	recv_arg
	)

Set the callback function for received packets that match the raw PCB's protocol and binding.

The callback function MUST either

• eat the packet by calling pbuf_free() and returning non-zero. The packet will not be passed to other raw PCBs or other protocol layers.
• not free the packet, and return zero. The packet will be matched against further PCBs and/or forwarded to another protocol layers.

Returns

non-zero if the packet was free()d, zero if the packet remains available for others.

References raw_pcb::recv, recv, and raw_pcb::recv_arg.

Referenced by pcb_new().

void raw_remove

(

struct raw_pcb *

pcb

)

Remove an RAW PCB.

Parameters

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

See Also

raw_new()

References memp_free(), raw_pcb::next, and NULL.

Referenced by do_delconn().

err_t raw_send	(	struct raw_pcb *	pcb,
		struct pbuf *	p
	)

Send the raw IP packet to the address given by raw_connect()

Parameters

pcb	the raw pcb which to send
p	the IP payload to send

References raw_sendto().

Referenced by do_send().

err_t raw_sendto	(	struct raw_pcb *	pcb,
		struct pbuf *	p,
		ip_addr_t *	ipaddr
	)

Send the raw IP packet to the given address.

Note that actually you cannot modify the IP headers (this is inconsistent with the receive callback where you actually get the IP headers), you can only specify the IP payload here. It requires some more changes in lwIP. (there will be a raw_send() function then.)

Parameters

pcb	the raw pcb which to send
p	the IP payload to send
ipaddr	the destination address of the IP packet

References ERR_MEM, ERR_RTE, ERR_VAL, ip4_addr1_16, ip4_addr2_16, ip4_addr3_16, ip4_addr4_16, netif::ip_addr, ip_addr_isany, ip_addr_isbroadcast, IP_HLEN, ip_output_if(), ip_route(), LWIP_ASSERT, LWIP_DBG_LEVEL_SERIOUS, LWIP_DBG_LEVEL_WARNING, LWIP_DBG_TRACE, LWIP_DEBUGF, NULL, pbuf_alloc(), pbuf_chain(), pbuf_free(), pbuf_header(), PBUF_IP, PBUF_RAM, raw_pcb::protocol, RAW_DEBUG, SOF_BROADCAST, pbuf::tot_len, and U16_F.

Referenced by do_send(), lwip_sendto(), and raw_send().

struct raw_pcb* raw_pcbs

static

The list of RAW PCBs.

Referenced by raw_input(), and raw_new().