ip4.h File Reference

#include "lwip/opt.h"
#include "lwip/def.h"
#include "lwip/pbuf.h"
#include "lwip/ip_addr.h"
#include "lwip/ip6_addr.h"
#include "lwip/err.h"
#include "lwip/netif.h"

Data Structures
struct	ip_hdr

Macros
#define	ip_debug_print(p)
#define	IP_DF   0x4000U /* don't fragment flag */
#define	IP_HLEN   20
#define	ip_init()   /* Compatibility define, no init needed. */
#define	IP_MF   0x2000U /* more fragments flag */
#define	ip_netif_get_local_ipX(netif)   (((netif) != NULL) ? ip_2_ipX(&((netif)->ip_addr)) : NULL)
#define	IP_OFFMASK   0x1fffU /* mask for fragmenting bits */
#define	IP_OPTIONS_SEND   LWIP_IGMP
	Currently, the function ip_output_if_opt() is only used with IGMP. More...
#define	IP_PROTO_ICMP   1
#define	IP_PROTO_IGMP   2
#define	IP_PROTO_TCP   6
#define	IP_PROTO_UDP   17
#define	IP_PROTO_UDPLITE   136
#define	IP_RF   0x8000U /* reserved fragment flag */
#define	IPH_CHKSUM(hdr)   ((hdr)->_chksum)
#define	IPH_CHKSUM_SET(hdr, chksum)   (hdr)->_chksum = (chksum)
#define	IPH_HL(hdr)   ((hdr)->_v_hl & 0x0f)
#define	IPH_ID(hdr)   ((hdr)->_id)
#define	IPH_ID_SET(hdr, id)   (hdr)->_id = (id)
#define	IPH_LEN(hdr)   ((hdr)->_len)
#define	IPH_LEN_SET(hdr, len)   (hdr)->_len = (len)
#define	IPH_OFFSET(hdr)   ((hdr)->_offset)
#define	IPH_OFFSET_SET(hdr, off)   (hdr)->_offset = (off)
#define	IPH_PROTO(hdr)   ((hdr)->_proto)
#define	IPH_PROTO_SET(hdr, proto)   (hdr)->_proto = (u8_t)(proto)
#define	IPH_TOS(hdr)   ((hdr)->_tos)
#define	IPH_TOS_SET(hdr, tos)   (hdr)->_tos = (tos)
#define	IPH_TTL(hdr)   ((hdr)->_ttl)
#define	IPH_TTL_SET(hdr, ttl)   (hdr)->_ttl = (u8_t)(ttl)
#define	IPH_V(hdr)   ((hdr)->_v_hl >> 4)
#define	IPH_VHL_SET(hdr, v, hl)   (hdr)->_v_hl = (((v) << 4) | (hl))

Functions
err_t	ip_input (struct pbuf *p, struct netif *inp)
	This function is called by the network interface device driver when an IP packet is received. More...
err_t	ip_output (struct pbuf *p, ip_addr_t *src, ip_addr_t *dest, u8_t ttl, u8_t tos, u8_t proto)
	Simple interface to ip_output_if. More...
err_t	ip_output_if (struct pbuf *p, ip_addr_t *src, ip_addr_t *dest, u8_t ttl, u8_t tos, u8_t proto, struct netif *netif)
	Sends an IP packet on a network interface. More...
err_t	ip_output_if_src (struct pbuf *p, ip_addr_t *src, ip_addr_t *dest, u8_t ttl, u8_t tos, u8_t proto, struct netif *netif)
	Same as ip_output_if() but 'src' address is not replaced by netif address when it is 'any'. More...
struct netif *	ip_route (ip_addr_t *dest)
	Finds the appropriate network interface for a given IP address. More...

Variables
PACK_STRUCT_BEGIN struct ip_hdr	PACK_STRUCT_STRUCT

#define ip_debug_print

(

p

)

Referenced by ip_input().

#define IP_DF   0x4000U /* don't fragment flag */

#define IP_HLEN   20

Referenced by ip_input().

#define ip_init

(

)

/* Compatibility define, no init needed. */

Referenced by lwip_init().

#define IP_MF   0x2000U /* more fragments flag */

Referenced by ip_input().

#define ip_netif_get_local_ipX

(

netif

)

(((netif) != NULL) ? ip_2_ipX(&((netif)->ip_addr)) : NULL)

#define IP_OFFMASK   0x1fffU /* mask for fragmenting bits */

Referenced by ip_input().

#define IP_OPTIONS_SEND   LWIP_IGMP

Currently, the function ip_output_if_opt() is only used with IGMP.

#define IP_PROTO_ICMP   1

Referenced by ip_input().

#define IP_PROTO_IGMP   2

Referenced by ip_input().

#define IP_PROTO_TCP   6

Referenced by ip_input().

#define IP_PROTO_UDP   17

Referenced by ip_input().

#define IP_PROTO_UDPLITE   136

Referenced by ip_input().

#define IP_RF   0x8000U /* reserved fragment flag */

#define IPH_CHKSUM

(

hdr

)

((hdr)->_chksum)

#define IPH_CHKSUM_SET	(		hdr,
			chksum
	)		(hdr)->_chksum = (chksum)

#define IPH_HL

(

hdr

)

((hdr)->_v_hl & 0x0f)

Referenced by ip_input().

#define IPH_ID

(

hdr

)

((hdr)->_id)

Referenced by ip_input().

#define IPH_ID_SET	(		hdr,
			id
	)		(hdr)->_id = (id)

#define IPH_LEN

(

hdr

)

((hdr)->_len)

Referenced by ip_input().

#define IPH_LEN_SET	(		hdr,
			len
	)		(hdr)->_len = (len)

#define IPH_OFFSET

(

hdr

)

((hdr)->_offset)

Referenced by ip_input().

#define IPH_OFFSET_SET	(		hdr,
			off
	)		(hdr)->_offset = (off)

#define IPH_PROTO

(

hdr

)

((hdr)->_proto)

Referenced by ip_input().

#define IPH_PROTO_SET	(		hdr,
			proto
	)		(hdr)->_proto = (u8_t)(proto)

#define IPH_TOS

(

hdr

)

((hdr)->_tos)

#define IPH_TOS_SET	(		hdr,
			tos
	)		(hdr)->_tos = (tos)

#define IPH_TTL

(

hdr

)

((hdr)->_ttl)

#define IPH_TTL_SET	(		hdr,
			ttl
	)		(hdr)->_ttl = (u8_t)(ttl)

#define IPH_V

(

hdr

)

((hdr)->_v_hl >> 4)

Referenced by ip_input().

#define IPH_VHL_SET	(		hdr,
			v,
			hl
	)		(hdr)->_v_hl = (((v) << 4) | (hl))

err_t ip_input	(	struct pbuf *	p,
		struct netif *	inp
	)

This function is called by the network interface device driver when an IP packet is received.

The function does the basic checks of the IP header such as packet size being at least larger than the header size etc. If the packet was not destined for us, the packet is forwarded (using ip_forward). The IP checksum is always checked.

Finally, the packet is sent to the upper layer protocol input function.

Parameters

p	the received IP packet (p->payload points to IP header)
inp	the netif on which this packet was received

Returns

ERR_OK if the packet was processed (could return ERR_* if it wasn't processed, but currently always returns ERR_OK)

References ip_globals::current_ip4_header, ip_globals::current_ip_header_tot_len, ip_globals::current_iphdr_dest, ip_globals::current_iphdr_src, ip_globals::current_netif, ERR_OK, netif::flags, ICMP_DUR_PROTO, if(), inet_chksum(), IP4_ADDR, ip4_addr_get_u32, IP_ACCEPT_LINK_LAYER_ADDRESSING, netif::ip_addr, ip_addr_cmp, ip_addr_copy, ip_addr_isany, ip_addr_isbroadcast, ip_addr_ismulticast, ip_addr_set_any, ip_current_dest_addr, ip_current_src_addr, ip_data, IP_DEBUG, ip_debug_print, IP_HLEN, IP_MF, IP_OFFMASK, IP_PROTO_ICMP, IP_PROTO_IGMP, IP_PROTO_TCP, IP_PROTO_UDP, IP_PROTO_UDPLITE, IP_STATS_INC, IPH_HL, IPH_ID, IPH_LEN, IPH_OFFSET, IPH_PROTO, IPH_V, ipX_2_ip, pbuf::len, LWIP_DBG_LEVEL_SERIOUS, LWIP_DBG_LEVEL_WARNING, LWIP_DBG_TRACE, LWIP_DEBUGF, netif::name, NETIF_FLAG_IGMP, netif_is_up, netif_list, netif::netmask, netif::next, ntohs, NULL, pbuf::payload, pbuf_free(), pbuf_header(), pbuf_header_force(), pbuf_realloc(), PP_HTONS, snmp_inc_ipinaddrerrors, snmp_inc_ipindelivers, snmp_inc_ipindiscards, snmp_inc_ipinhdrerrors, snmp_inc_ipinreceives, snmp_inc_ipinunknownprotos, pbuf::tot_len, X16_F, and X32_F.

Referenced by netif_init(), tcpip_input(), and tcpip_thread().

err_t ip_output	(	struct pbuf *	p,
		ip_addr_t *	src,
		ip_addr_t *	dest,
		u8_t	ttl,
		u8_t	tos,
		u8_t	proto
	)

Simple interface to ip_output_if.

It finds the outgoing network interface and calls upon ip_output_if to do the actual work.

Parameters

p	the packet to send (p->payload points to the data, e.g. next protocol header; if dest == IP_HDRINCL, p already includes an IP header and p->payload points to that IP header)
src	the source IP address to send from (if src == IP_ADDR_ANY, the IP address of the netif used to send is used as source address)
dest	the destination IP address to send the packet to
ttl	the TTL value to be set in the IP header
tos	the TOS value to be set in the IP header
proto	the PROTOCOL to be set in the IP header

Returns

ERR_RTE if no route is found see ip_output_if() for more return values

References ERR_RTE, ip4_addr1_16, ip4_addr2_16, ip4_addr3_16, ip4_addr4_16, IP_DEBUG, ip_output_if(), ip_route(), IP_STATS_INC, LWIP_DEBUGF, LWIP_IP_CHECK_PBUF_REF_COUNT_FOR_TX, and NULL.

err_t ip_output_if	(	struct pbuf *	p,
		ip_addr_t *	src,
		ip_addr_t *	dest,
		u8_t	ttl,
		u8_t	tos,
		u8_t	proto,
		struct netif *	netif
	)

Sends an IP packet on a network interface.

This function constructs the IP header and calculates the IP header checksum. If the source IP address is NULL, the IP address of the outgoing network interface is filled in as source address. If the destination IP address is IP_HDRINCL, p is assumed to already include an IP header and p->payload points to it instead of the data.

Parameters

p	the packet to send (p->payload points to the data, e.g. next protocol header; if dest == IP_HDRINCL, p already includes an IP header and p->payload points to that IP header)
src	the source IP address to send from (if src == IP_ADDR_ANY, the IP address of the netif used to send is used as source address)
dest	the destination IP address to send the packet to
ttl	the TTL value to be set in the IP header
tos	the TOS value to be set in the IP header
proto	the PROTOCOL to be set in the IP header
netif	the netif on which to send this packet

Returns

ERR_OK if the packet was sent OK ERR_BUF if p doesn't have enough space for IP/LINK headers returns errors returned by netif->output

Note

ip_id: RFC791 "some host may be able to simply use unique identifiers independent of destination"

References NULL.

Referenced by ip_output().

err_t ip_output_if_src	(	struct pbuf *	p,
		ip_addr_t *	src,
		ip_addr_t *	dest,
		u8_t	ttl,
		u8_t	tos,
		u8_t	proto,
		struct netif *	netif
	)

Same as ip_output_if() but 'src' address is not replaced by netif address when it is 'any'.

References NULL.

struct netif* ip_route

(

ip_addr_t *

dest

)

Finds the appropriate network interface for a given IP address.

It searches the list of network interfaces linearly. A match is found if the masked IP address of the network interface equals the masked IP address given to the function.

Parameters

dest	the destination IP address for which to find the route

Returns

the netif on which to send to reach dest

References ip4_addr1_16, ip4_addr2_16, ip4_addr3_16, ip4_addr4_16, netif::ip_addr, ip_addr_isany, ip_addr_netcmp, IP_DEBUG, IP_STATS_INC, LWIP_DBG_LEVEL_SERIOUS, LWIP_DEBUGF, LWIP_IPV6, netif_default, netif_is_up, netif_list, netif::netmask, netif::next, NULL, snmp_inc_ipoutnoroutes, and U16_F.

Referenced by ip_output().

PACK_STRUCT_BEGIN struct ip_hdr PACK_STRUCT_STRUCT