diff options
Diffstat (limited to 'lwip/src/core/ipv4/autoip.c')
| -rw-r--r-- | lwip/src/core/ipv4/autoip.c | 527 |
1 files changed, 527 insertions, 0 deletions
diff --git a/lwip/src/core/ipv4/autoip.c b/lwip/src/core/ipv4/autoip.c new file mode 100644 index 0000000..9f7139b --- /dev/null +++ b/lwip/src/core/ipv4/autoip.c @@ -0,0 +1,527 @@ +/** + * @file + * AutoIP Automatic LinkLocal IP Configuration + * + * This is a AutoIP implementation for the lwIP TCP/IP stack. It aims to conform + * with RFC 3927. + * + * @defgroup autoip AUTOIP + * @ingroup ip4 + * AUTOIP related functions + * USAGE: + * + * define @ref LWIP_AUTOIP 1 in your lwipopts.h + * Options: + * AUTOIP_TMR_INTERVAL msecs, + * 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 @ref LWIP_DHCP_AUTOIP_COOP 1 in your lwipopts.h. + * - Configure your DHCP Client. + * + * @see netifapi_autoip + */ + +/* + * + * 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> + */ + +#include "lwip/opt.h" + +#if LWIP_IPV4 && 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 "lwip/etharp.h" +#include "lwip/prot/autoip.h" + +#include <string.h> + +/** 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_data(netif)? netif_autoip_data(netif)->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) \ + lwip_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 err_t autoip_arp_announce(struct netif *netif); +static void autoip_start_probing(struct netif *netif); + +/** + * @ingroup autoip + * 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 autoip (uninitialised) autoip struct allocated by the application + */ +void +autoip_set_struct(struct netif *netif, struct autoip *autoip) +{ + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ASSERT("netif != NULL", netif != NULL); + LWIP_ASSERT("autoip != NULL", autoip != NULL); + LWIP_ASSERT("netif already has a struct autoip set", + netif_autoip_data(netif) == NULL); + + /* clear data structure */ + memset(autoip, 0, sizeof(struct autoip)); + /* autoip->state = AUTOIP_STATE_OFF; */ + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_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) +{ + struct autoip *autoip = netif_autoip_data(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) +{ + struct autoip *autoip = netif_autoip_data(netif); + + /* RFC3927, 2.5 "Conflict Detection and Defense" allows two options where + a) means retreat on the first conflict and + b) allows to keep an already configured address when having only one + conflict in 10 seconds + We use option b) since it helps to improve the chance that one of the two + conflicting hosts may be able to retain its address. */ + + if (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")); + + /* Active TCP sessions are aborted when removing the ip addresss */ + 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); + autoip->lastconflict = DEFEND_INTERVAL * AUTOIP_TICKS_PER_SECOND; + } +} + +/** + * 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, ip4_addr_t *ipaddr) +{ + struct autoip *autoip = netif_autoip_data(netif); + + /* 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 = lwip_ntohl(LWIP_AUTOIP_CREATE_SEED_ADDR(netif)); + addr += 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, lwip_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)(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) +{ + struct autoip *autoip = netif_autoip_data(netif); + /* this works because netif->ip_addr is ANY */ + return etharp_request(netif, &autoip->llipaddr); +} + +/** + * 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_gratuitous(netif); +} + +/** + * 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_data(netif); + ip4_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_addr(netif, &autoip->llipaddr, &sn_mask, &gw_addr); + /* interface is used by routing now that an address is set */ + + return ERR_OK; +} + +/** + * @ingroup autoip + * 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_data(netif); + err_t result = ERR_OK; + + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ERROR("netif is not up, old style port?", netif_is_up(netif), return ERR_ARG;); + + /* Set IP-Address, Netmask and Gateway to 0 to make sure that + * ARP Packets are formed correctly + */ + netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4); + + 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_calloc(1, sizeof(struct autoip)); + if (autoip == NULL) { + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, + ("autoip_start(): could not allocate autoip\n")); + return ERR_MEM; + } + /* store this AutoIP client in the netif */ + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_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; + ip4_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_data(netif); + + 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(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr), + ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr))); + + /* time to wait to first probe, this is randomly + * chosen 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 + * acquiring 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) +{ + struct autoip *autoip = netif_autoip_data(netif); + + if (autoip && (autoip->state != AUTOIP_STATE_OFF)) { + autoip_start_probing(netif); + } +} + +/** + * @ingroup autoip + * Stop AutoIP client + * + * @param netif network interface on which stop the AutoIP client + */ +err_t +autoip_stop(struct netif *netif) +{ + struct autoip *autoip = netif_autoip_data(netif); + + LWIP_ASSERT_CORE_LOCKED(); + if (autoip != NULL) { + autoip->state = AUTOIP_STATE_OFF; + if (ip4_addr_islinklocal(netif_ip4_addr(netif))) { + netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4); + } + } + return ERR_OK; +} + +/** + * Has to be called in loop every AUTOIP_TMR_INTERVAL milliseconds + */ +void +autoip_tmr(void) +{ + struct netif *netif; + /* loop through netif's */ + NETIF_FOREACH(netif) { + struct autoip *autoip = netif_autoip_data(netif); + /* only act on AutoIP configured interfaces */ + if (autoip != NULL) { + if (autoip->lastconflict > 0) { + autoip->lastconflict--; + } + + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, + ("autoip_tmr() AutoIP-State: %"U16_F", ttw=%"U16_F"\n", + (u16_t)(autoip->state), autoip->ttw)); + + if (autoip->ttw > 0) { + autoip->ttw--; + } + + switch (autoip->state) { + case AUTOIP_STATE_PROBING: + if (autoip->ttw == 0) { + if (autoip->sent_num >= PROBE_NUM) { + /* Switch to ANNOUNCING: now we can bind to an IP address and use it */ + autoip->state = AUTOIP_STATE_ANNOUNCING; + autoip_bind(netif); + /* autoip_bind() calls netif_set_addr(): this triggers a gratuitous ARP + which counts as an announcement */ + autoip->sent_num = 1; + 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(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr), + ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr))); + } else { + autoip_arp_probe(netif); + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_tmr() PROBING Sent Probe\n")); + autoip->sent_num++; + if (autoip->sent_num == PROBE_NUM) { + /* calculate time to wait to for announce */ + autoip->ttw = ANNOUNCE_WAIT * AUTOIP_TICKS_PER_SECOND; + } else { + /* calculate time to wait to next probe */ + 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 (autoip->ttw == 0) { + autoip_arp_announce(netif); + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_tmr() ANNOUNCING Sent Announce\n")); + autoip->ttw = ANNOUNCE_INTERVAL * AUTOIP_TICKS_PER_SECOND; + autoip->sent_num++; + + if (autoip->sent_num >= ANNOUNCE_NUM) { + autoip->state = AUTOIP_STATE_BOUND; + autoip->sent_num = 0; + 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(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr), + ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr))); + } + } + break; + + default: + /* nothing to do in other states */ + break; + } + } + } +} + +/** + * Handles every incoming ARP Packet, called by etharp_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) +{ + struct autoip *autoip = netif_autoip_data(netif); + + LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_arp_reply()\n")); + if ((autoip != NULL) && (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 + */ + ip4_addr_t sipaddr, dipaddr; + struct eth_addr netifaddr; + SMEMCPY(netifaddr.addr, netif->hwaddr, ETH_HWADDR_LEN); + + /* Copy struct ip4_addr_wordaligned to aligned ip4_addr, to support compilers without + * structure packing (not using structure copy which breaks strict-aliasing rules). + */ + IPADDR_WORDALIGNED_COPY_TO_IP4_ADDR_T(&sipaddr, &hdr->sipaddr); + IPADDR_WORDALIGNED_COPY_TO_IP4_ADDR_T(&dipaddr, &hdr->dipaddr); + + if (autoip->state == AUTOIP_STATE_PROBING) { + /* 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 ((ip4_addr_cmp(&sipaddr, &autoip->llipaddr)) || + (ip4_addr_isany_val(sipaddr) && + ip4_addr_cmp(&dipaddr, &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 (ip4_addr_cmp(&sipaddr, &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); + } + } + } +} + +/** check if AutoIP supplied netif->ip_addr + * + * @param netif the netif to check + * @return 1 if AutoIP supplied netif->ip_addr (state BOUND or ANNOUNCING), + * 0 otherwise + */ +u8_t +autoip_supplied_address(const struct netif *netif) +{ + if ((netif != NULL) && (netif_autoip_data(netif) != NULL)) { + struct autoip *autoip = netif_autoip_data(netif); + return (autoip->state == AUTOIP_STATE_BOUND) || (autoip->state == AUTOIP_STATE_ANNOUNCING); + } + return 0; +} + +u8_t +autoip_accept_packet(struct netif *netif, const ip4_addr_t *addr) +{ + struct autoip *autoip = netif_autoip_data(netif); + return (autoip != NULL) && ip4_addr_cmp(addr, &(autoip->llipaddr)); +} + +#endif /* LWIP_IPV4 && LWIP_AUTOIP */ |