ip.c File Reference

#include "lwip/opt.h"
#include "lwip/ip.h"
#include "lwip/def.h"
#include "lwip/mem.h"
#include "lwip/ip_frag.h"
#include "lwip/inet_chksum.h"
#include "lwip/netif.h"
#include "lwip/icmp.h"
#include "lwip/igmp.h"
#include "lwip/raw.h"
#include "lwip/udp.h"
#include "lwip/tcp_impl.h"
#include "lwip/snmp.h"
#include "lwip/dhcp.h"
#include "lwip/autoip.h"
#include "lwip/stats.h"
#include "arch/perf.h"
#include <string.h>

Defines
#define	LWIP_INLINE_IP_CHKSUM   1
Functions
netif *	ip_route (ip_addr_t *dest)
err_t	ip_input (struct pbuf *p, struct netif *inp)
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)
err_t	ip_output (struct pbuf *p, ip_addr_t *src, ip_addr_t *dest, u8_t ttl, u8_t tos, u8_t proto)
Variables
netif *	current_netif
const struct ip_hdr *	current_header
ip_addr_t	current_iphdr_src
ip_addr_t	current_iphdr_dest

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Detailed Description

This is the IPv4 layer implementation for incoming and outgoing IP traffic.

See also:

ip_frag.c

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Define Documentation

#define LWIP_INLINE_IP_CHKSUM   1

Set this to 0 in the rare case of wanting to call an extra function to generate the IP checksum (in contrast to calculating it on-the-fly).

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Function Documentation

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)

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

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"

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

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Variable Documentation

const struct ip_hdr* current_header

Header of the input packet currently being processed.

ip_addr_t current_iphdr_dest

Destination IP address of current_header

ip_addr_t current_iphdr_src

Source IP address of current_header

struct netif* current_netif

The interface that provided the packet for the current callback invocation.

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