sanchayanmaity/minix
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
minix/lib/liblwip/core/ipv4/autoip.c
Tomas Hruby abab24b785 LWIP - liblwip 
lwip-1.4.0-rc1 imported as liblwip
2011-04-07 07:43:36 +00:00

541 lines
18 KiB
C
Raw Blame History

/**
* @file
* AutoIP Automatic LinkLocal IP Configuration
*
*/
/*
*
* Copyright (c) 2007 Dominik Spies <kontakt@dspies.de>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* Author: Dominik Spies <kontakt@dspies.de>
*
* This is a AutoIP implementation for the lwIP TCP/IP stack. It aims to conform
* with RFC 3927.
*
*
* Please coordinate changes and requests with Dominik Spies
* <kontakt@dspies.de>
*/
/*******************************************************************************
* USAGE:
*
* define LWIP_AUTOIP 1 in your lwipopts.h
*
* If you don't use tcpip.c (so, don't call, you don't call tcpip_init):
* - First, call autoip_init().
* - call autoip_tmr() all AUTOIP_TMR_INTERVAL msces,
* that should be defined in autoip.h.
* I recommend a value of 100. The value must divide 1000 with a remainder almost 0.
* Possible values are 1000, 500, 333, 250, 200, 166, 142, 125, 111, 100 ....
*
* Without DHCP:
* - Call autoip_start() after netif_add().
*
* With DHCP:
* - define LWIP_DHCP_AUTOIP_COOP 1 in your lwipopts.h.
* - Configure your DHCP Client.
*
*/
#include "lwip/opt.h"
#if LWIP_AUTOIP /* don't build if not configured for use in lwipopts.h */
#include "lwip/mem.h"
#include "lwip/udp.h"
#include "lwip/ip_addr.h"
#include "lwip/netif.h"
#include "lwip/autoip.h"
#include "netif/etharp.h"
#include <stdlib.h>
#include <string.h>
/* 169.254.0.0 */
#define AUTOIP_NET 0xA9FE0000
/* 169.254.1.0 */
#define AUTOIP_RANGE_START (AUTOIP_NET | 0x0100)
/* 169.254.254.255 */
#define AUTOIP_RANGE_END (AUTOIP_NET | 0xFEFF)
/** Pseudo random macro based on netif informations.
* You could use "rand()" from the C Library if you define LWIP_AUTOIP_RAND in lwipopts.h */
#ifndef LWIP_AUTOIP_RAND
#define LWIP_AUTOIP_RAND(netif) ( (((u32_t)((netif->hwaddr[5]) & 0xff) << 24) | \
((u32_t)((netif->hwaddr[3]) & 0xff) << 16) | \
((u32_t)((netif->hwaddr[2]) & 0xff) << 8) | \
((u32_t)((netif->hwaddr[4]) & 0xff))) + \
(netif->autoip?netif->autoip->tried_llipaddr:0))
#endif /* LWIP_AUTOIP_RAND */
/**
* Macro that generates the initial IP address to be tried by AUTOIP.
* If you want to override this, define it to something else in lwipopts.h.
*/
#ifndef LWIP_AUTOIP_CREATE_SEED_ADDR
#define LWIP_AUTOIP_CREATE_SEED_ADDR(netif) \
htonl(AUTOIP_RANGE_START + ((u32_t)(((u8_t)(netif->hwaddr[4])) | \
((u32_t)((u8_t)(netif->hwaddr[5]))) << 8)))
#endif /* LWIP_AUTOIP_CREATE_SEED_ADDR */
/* static functions */
static void autoip_handle_arp_conflict(struct netif *netif);
/* creates a pseudo random LL IP-Address for a network interface */
static void autoip_create_addr(struct netif *netif, ip_addr_t *ipaddr);
/* sends an ARP probe */
static err_t autoip_arp_probe(struct netif *netif);
/* sends an ARP announce */
static err_t autoip_arp_announce(struct netif *netif);
/* configure interface for use with current LL IP-Address */
static err_t autoip_bind(struct netif *netif);
/* start sending probes for llipaddr */
static void autoip_start_probing(struct netif *netif);
/**
* Initialize this module
*/
void
autoip_init(void)
{
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_init()\n"));
}
/** Set a statically allocated struct autoip to work with.
* Using this prevents autoip_start to allocate it using mem_malloc.
*
* @param netif the netif for which to set the struct autoip
* @param dhcp (uninitialised) dhcp struct allocated by the application
*/
void
autoip_set_struct(struct netif *netif, struct autoip *autoip)
{
LWIP_ASSERT("netif != NULL", netif != NULL);
LWIP_ASSERT("autoip != NULL", autoip != NULL);
LWIP_ASSERT("netif already has a struct autoip set", netif->autoip == NULL);
/* clear data structure */
memset(autoip, 0, sizeof(struct autoip));
/* autoip->state = AUTOIP_STATE_OFF; */
netif->autoip = autoip;
}
/** Restart AutoIP client and check the next address (conflict detected)
*
* @param netif The netif under AutoIP control
*/
static void
autoip_restart(struct netif *netif)
{
netif->autoip->tried_llipaddr++;
autoip_start(netif);
}
/**
* Handle a IP address conflict after an ARP conflict detection
*/
static void
autoip_handle_arp_conflict(struct netif *netif)
{
/* Somehow detect if we are defending or retreating */
unsigned char defend = 1; /* tbd */
if(defend) {
if(netif->autoip->lastconflict > 0) {
/* retreat, there was a conflicting ARP in the last
* DEFEND_INTERVAL seconds
*/
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
("autoip_handle_arp_conflict(): we are defending, but in DEFEND_INTERVAL, retreating\n"));
/* TODO: close all TCP sessions */
autoip_restart(netif);
} else {
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
("autoip_handle_arp_conflict(): we are defend, send ARP Announce\n"));
autoip_arp_announce(netif);
netif->autoip->lastconflict = DEFEND_INTERVAL * AUTOIP_TICKS_PER_SECOND;
}
} else {
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
("autoip_handle_arp_conflict(): we do not defend, retreating\n"));
/* TODO: close all TCP sessions */
autoip_restart(netif);
}
}
/**
* Create an IP-Address out of range 169.254.1.0 to 169.254.254.255
*
* @param netif network interface on which create the IP-Address
* @param ipaddr ip address to initialize
*/
static void
autoip_create_addr(struct netif *netif, ip_addr_t *ipaddr)
{
/* Here we create an IP-Address out of range 169.254.1.0 to 169.254.254.255
* compliant to RFC 3927 Section 2.1
* We have 254 * 256 possibilities */
u32_t addr = ntohl(LWIP_AUTOIP_CREATE_SEED_ADDR(netif));
addr += netif->autoip->tried_llipaddr;
addr = AUTOIP_NET | (addr & 0xffff);
/* Now, 169.254.0.0 <= addr <= 169.254.255.255 */
if (addr < AUTOIP_RANGE_START) {
addr += AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1;
}
if (addr > AUTOIP_RANGE_END) {
addr -= AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1;
}
LWIP_ASSERT("AUTOIP address not in range", (addr >= AUTOIP_RANGE_START) &&
(addr <= AUTOIP_RANGE_END));
ip4_addr_set_u32(ipaddr, htonl(addr));
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
("autoip_create_addr(): tried_llipaddr=%"U16_F", %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
(u16_t)(netif->autoip->tried_llipaddr), ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr),
ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr)));
}
/**
* Sends an ARP probe from a network interface
*
* @param netif network interface used to send the probe
*/
static err_t
autoip_arp_probe(struct netif *netif)
{
return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, &ethbroadcast,
(struct eth_addr *)netif->hwaddr, IP_ADDR_ANY, &ethzero,
&netif->autoip->llipaddr, ARP_REQUEST);
}
/**
* Sends an ARP announce from a network interface
*
* @param netif network interface used to send the announce
*/
static err_t
autoip_arp_announce(struct netif *netif)
{
return etharp_raw(netif, (struct eth_addr *)netif->hwaddr, &ethbroadcast,
(struct eth_addr *)netif->hwaddr, &netif->autoip->llipaddr, &ethzero,
&netif->autoip->llipaddr, ARP_REQUEST);
}
/**
* Configure interface for use with current LL IP-Address
*
* @param netif network interface to configure with current LL IP-Address
*/
static err_t
autoip_bind(struct netif *netif)
{
struct autoip *autoip = netif->autoip;
ip_addr_t sn_mask, gw_addr;
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
("autoip_bind(netif=%p) %c%c%"U16_F" %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
(void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num,
ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
IP4_ADDR(&sn_mask, 255, 255, 0, 0);
IP4_ADDR(&gw_addr, 0, 0, 0, 0);
netif_set_ipaddr(netif, &autoip->llipaddr);
netif_set_netmask(netif, &sn_mask);
netif_set_gw(netif, &gw_addr);
/* bring the interface up */
netif_set_up(netif);
return ERR_OK;
}
/**
* Start AutoIP client
*
* @param netif network interface on which start the AutoIP client
*/
err_t
autoip_start(struct netif *netif)
{
struct autoip *autoip = netif->autoip;
err_t result = ERR_OK;
if(netif_is_up(netif)) {
netif_set_down(netif);
}
/* Set IP-Address, Netmask and Gateway to 0 to make sure that
* ARP Packets are formed correctly
*/
ip_addr_set_zero(&netif->ip_addr);
ip_addr_set_zero(&netif->netmask);
ip_addr_set_zero(&netif->gw);
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
("autoip_start(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0],
netif->name[1], (u16_t)netif->num));
if(autoip == NULL) {
/* no AutoIP client attached yet? */
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
("autoip_start(): starting new AUTOIP client\n"));
autoip = (struct autoip *)mem_malloc(sizeof(struct autoip));
if(autoip == NULL) {
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
("autoip_start(): could not allocate autoip\n"));
return ERR_MEM;
}
memset(autoip, 0, sizeof(struct autoip));
/* store this AutoIP client in the netif */
netif->autoip = autoip;
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_start(): allocated autoip"));
} else {
autoip->state = AUTOIP_STATE_OFF;
autoip->ttw = 0;
autoip->sent_num = 0;
ip_addr_set_zero(&autoip->llipaddr);
autoip->lastconflict = 0;
}
autoip_create_addr(netif, &(autoip->llipaddr));
autoip_start_probing(netif);
return result;
}
static void
autoip_start_probing(struct netif *netif)
{
struct autoip *autoip = netif->autoip;
autoip->state = AUTOIP_STATE_PROBING;
autoip->sent_num = 0;
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
("autoip_start_probing(): changing state to PROBING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
ip4_addr1_16(&netif->autoip->llipaddr), ip4_addr2_16(&netif->autoip->llipaddr),
ip4_addr3_16(&netif->autoip->llipaddr), ip4_addr4_16(&netif->autoip->llipaddr)));
/* time to wait to first probe, this is randomly
* choosen out of 0 to PROBE_WAIT seconds.
* compliant to RFC 3927 Section 2.2.1
*/
autoip->ttw = (u16_t)(LWIP_AUTOIP_RAND(netif) % (PROBE_WAIT * AUTOIP_TICKS_PER_SECOND));
/*
* if we tried more then MAX_CONFLICTS we must limit our rate for
* accquiring and probing address
* compliant to RFC 3927 Section 2.2.1
*/
if(autoip->tried_llipaddr > MAX_CONFLICTS) {
autoip->ttw = RATE_LIMIT_INTERVAL * AUTOIP_TICKS_PER_SECOND;
}
}
/**
* Handle a possible change in the network configuration.
*
* If there is an AutoIP address configured, take the interface down
* and begin probing with the same address.
*/
void
autoip_network_changed(struct netif *netif)
{
if (netif->autoip && netif->autoip->state != AUTOIP_STATE_OFF) {
netif_set_down(netif);
autoip_start_probing(netif);
}
}
/**
* Stop AutoIP client
*
* @param netif network interface on which stop the AutoIP client
*/
err_t
autoip_stop(struct netif *netif)
{
netif->autoip->state = AUTOIP_STATE_OFF;
netif_set_down(netif);
return ERR_OK;
}
/**
* Has to be called in loop every AUTOIP_TMR_INTERVAL milliseconds
*/
void
autoip_tmr()
{
struct netif *netif = netif_list;
/* loop through netif's */
while (netif != NULL) {
/* only act on AutoIP configured interfaces */
if (netif->autoip != NULL) {
if(netif->autoip->lastconflict > 0) {
netif->autoip->lastconflict--;
}
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
("autoip_tmr() AutoIP-State: %"U16_F", ttw=%"U16_F"\n",
(u16_t)(netif->autoip->state), netif->autoip->ttw));
switch(netif->autoip->state) {
case AUTOIP_STATE_PROBING:
if(netif->autoip->ttw > 0) {
netif->autoip->ttw--;
} else {
if(netif->autoip->sent_num >= PROBE_NUM) {
netif->autoip->state = AUTOIP_STATE_ANNOUNCING;
netif->autoip->sent_num = 0;
netif->autoip->ttw = ANNOUNCE_WAIT * AUTOIP_TICKS_PER_SECOND;
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
("autoip_tmr(): changing state to ANNOUNCING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
ip4_addr1_16(&netif->autoip->llipaddr), ip4_addr2_16(&netif->autoip->llipaddr),
ip4_addr3_16(&netif->autoip->llipaddr), ip4_addr4_16(&netif->autoip->llipaddr)));
} else {
autoip_arp_probe(netif);
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
("autoip_tmr() PROBING Sent Probe\n"));
netif->autoip->sent_num++;
/* calculate time to wait to next probe */
netif->autoip->ttw = (u16_t)((LWIP_AUTOIP_RAND(netif) %
((PROBE_MAX - PROBE_MIN) * AUTOIP_TICKS_PER_SECOND) ) +
PROBE_MIN * AUTOIP_TICKS_PER_SECOND);
}
}
break;
case AUTOIP_STATE_ANNOUNCING:
if(netif->autoip->ttw > 0) {
netif->autoip->ttw--;
} else {
if(netif->autoip->sent_num == 0) {
/* We are here the first time, so we waited ANNOUNCE_WAIT seconds
* Now we can bind to an IP address and use it.
*
* autoip_bind calls netif_set_up. This triggers a gratuitous ARP
* which counts as an announcement.
*/
autoip_bind(netif);
} else {
autoip_arp_announce(netif);
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
("autoip_tmr() ANNOUNCING Sent Announce\n"));
}
netif->autoip->ttw = ANNOUNCE_INTERVAL * AUTOIP_TICKS_PER_SECOND;
netif->autoip->sent_num++;
if(netif->autoip->sent_num >= ANNOUNCE_NUM) {
netif->autoip->state = AUTOIP_STATE_BOUND;
netif->autoip->sent_num = 0;
netif->autoip->ttw = 0;
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
("autoip_tmr(): changing state to BOUND: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
ip4_addr1_16(&netif->autoip->llipaddr), ip4_addr2_16(&netif->autoip->llipaddr),
ip4_addr3_16(&netif->autoip->llipaddr), ip4_addr4_16(&netif->autoip->llipaddr)));
}
}
break;
}
}
/* proceed to next network interface */
netif = netif->next;
}
}
/**
* Handles every incoming ARP Packet, called by etharp_arp_input.
*
* @param netif network interface to use for autoip processing
* @param hdr Incoming ARP packet
*/
void
autoip_arp_reply(struct netif *netif, struct etharp_hdr *hdr)
{
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_arp_reply()\n"));
if ((netif->autoip != NULL) && (netif->autoip->state != AUTOIP_STATE_OFF)) {
/* when ip.src == llipaddr && hw.src != netif->hwaddr
*
* when probing ip.dst == llipaddr && hw.src != netif->hwaddr
* we have a conflict and must solve it
*/
ip_addr_t sipaddr, dipaddr;
struct eth_addr netifaddr;
netifaddr.addr[0] = netif->hwaddr[0];
netifaddr.addr[1] = netif->hwaddr[1];
netifaddr.addr[2] = netif->hwaddr[2];
netifaddr.addr[3] = netif->hwaddr[3];
netifaddr.addr[4] = netif->hwaddr[4];
netifaddr.addr[5] = netif->hwaddr[5];
/* Copy struct ip_addr2 to aligned ip_addr, to support compilers without
* structure packing (not using structure copy which breaks strict-aliasing rules).
*/
IPADDR2_COPY(&sipaddr, &hdr->sipaddr);
IPADDR2_COPY(&dipaddr, &hdr->dipaddr);
if ((netif->autoip->state == AUTOIP_STATE_PROBING) ||
((netif->autoip->state == AUTOIP_STATE_ANNOUNCING) &&
(netif->autoip->sent_num == 0))) {
/* RFC 3927 Section 2.2.1:
* from beginning to after ANNOUNCE_WAIT
* seconds we have a conflict if
* ip.src == llipaddr OR
* ip.dst == llipaddr && hw.src != own hwaddr
*/
if ((ip_addr_cmp(&sipaddr, &netif->autoip->llipaddr)) ||
(ip_addr_cmp(&dipaddr, &netif->autoip->llipaddr) &&
!eth_addr_cmp(&netifaddr, &hdr->shwaddr))) {
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
("autoip_arp_reply(): Probe Conflict detected\n"));
autoip_restart(netif);
}
} else {
/* RFC 3927 Section 2.5:
* in any state we have a conflict if
* ip.src == llipaddr && hw.src != own hwaddr
*/
if (ip_addr_cmp(&sipaddr, &netif->autoip->llipaddr) &&
!eth_addr_cmp(&netifaddr, &hdr->shwaddr)) {
LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
("autoip_arp_reply(): Conflicting ARP-Packet detected\n"));
autoip_handle_arp_conflict(netif);
}
}
}
}
#endif /* LWIP_AUTOIP */
Reference in a new issue View git blame Copy permalink