blob: 41444a4c75bb449310a66a72580f1f2d8b81f2e4 [file] [log] [blame]
/**
* @file
*
* @defgroup dhcp6 DHCPv6
* @ingroup ip6
* DHCPv6 client: IPv6 address autoconfiguration as per
* RFC 3315 (stateful DHCPv6) and
* RFC 3736 (stateless DHCPv6).
*
* For now, only stateless DHCPv6 is implemented!
*
* TODO:
* - enable/disable API to not always start when RA is received
* - stateful DHCPv6 (for now, only stateless DHCPv6 for DNS and NTP servers works)
* - create Client Identifier?
* - only start requests if a valid local address is available on the netif
* - only start information requests if required (not for every RA)
*
* dhcp6_enable_stateful() enables stateful DHCPv6 for a netif (stateless disabled)\n
* dhcp6_enable_stateless() enables stateless DHCPv6 for a netif (stateful disabled)\n
* dhcp6_disable() disable DHCPv6 for a netif
*
* When enabled, requests are only issued after receipt of RA with the
* corresponding bits set.
*/
/*
* Copyright (c) 2018 Simon Goldschmidt
* 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.
*
* This file is part of the lwIP TCP/IP stack.
*
* Author: Simon Goldschmidt <goldsimon@gmx.de>
*/
#include "lwip/opt.h"
#if LWIP_IPV6 && LWIP_IPV6_DHCP6 /* don't build if not configured for use in lwipopts.h */
#include "lwip/dhcp6.h"
#include "lwip/prot/dhcp6.h"
#include "lwip/def.h"
#include "lwip/udp.h"
#include "lwip/dns.h"
#include <string.h>
#ifdef LWIP_HOOK_FILENAME
#include LWIP_HOOK_FILENAME
#endif
#ifndef LWIP_HOOK_DHCP6_APPEND_OPTIONS
#define LWIP_HOOK_DHCP6_APPEND_OPTIONS(netif, dhcp6, state, msg, msg_type, options_len_ptr, max_len)
#endif
#ifndef LWIP_HOOK_DHCP6_PARSE_OPTION
#define LWIP_HOOK_DHCP6_PARSE_OPTION(netif, dhcp6, state, msg, msg_type, option, len, pbuf, offset) do { LWIP_UNUSED_ARG(msg); } while(0)
#endif
#if LWIP_DNS && LWIP_DHCP6_MAX_DNS_SERVERS
#if DNS_MAX_SERVERS > LWIP_DHCP6_MAX_DNS_SERVERS
#define LWIP_DHCP6_PROVIDE_DNS_SERVERS LWIP_DHCP6_MAX_DNS_SERVERS
#else
#define LWIP_DHCP6_PROVIDE_DNS_SERVERS DNS_MAX_SERVERS
#endif
#else
#define LWIP_DHCP6_PROVIDE_DNS_SERVERS 0
#endif
/** Option handling: options are parsed in dhcp6_parse_reply
* and saved in an array where other functions can load them from.
* This might be moved into the struct dhcp6 (not necessarily since
* lwIP is single-threaded and the array is only used while in recv
* callback). */
enum dhcp6_option_idx {
DHCP6_OPTION_IDX_CLI_ID = 0,
DHCP6_OPTION_IDX_SERVER_ID,
#if LWIP_DHCP6_PROVIDE_DNS_SERVERS
DHCP6_OPTION_IDX_DNS_SERVER,
DHCP6_OPTION_IDX_DOMAIN_LIST,
#endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */
#if LWIP_DHCP6_GET_NTP_SRV
DHCP6_OPTION_IDX_NTP_SERVER,
#endif /* LWIP_DHCP_GET_NTP_SRV */
DHCP6_OPTION_IDX_MAX
};
struct dhcp6_option_info {
u8_t option_given;
u16_t val_start;
u16_t val_length;
};
/** Holds the decoded option info, only valid while in dhcp6_recv. */
struct dhcp6_option_info dhcp6_rx_options[DHCP6_OPTION_IDX_MAX];
#define dhcp6_option_given(dhcp6, idx) (dhcp6_rx_options[idx].option_given != 0)
#define dhcp6_got_option(dhcp6, idx) (dhcp6_rx_options[idx].option_given = 1)
#define dhcp6_clear_option(dhcp6, idx) (dhcp6_rx_options[idx].option_given = 0)
#define dhcp6_clear_all_options(dhcp6) (memset(dhcp6_rx_options, 0, sizeof(dhcp6_rx_options)))
#define dhcp6_get_option_start(dhcp6, idx) (dhcp6_rx_options[idx].val_start)
#define dhcp6_get_option_length(dhcp6, idx) (dhcp6_rx_options[idx].val_length)
#define dhcp6_set_option(dhcp6, idx, start, len) do { dhcp6_rx_options[idx].val_start = (start); dhcp6_rx_options[idx].val_length = (len); }while(0)
const ip_addr_t dhcp6_All_DHCP6_Relay_Agents_and_Servers = IPADDR6_INIT_HOST(0xFF020000, 0, 0, 0x00010002);
const ip_addr_t dhcp6_All_DHCP6_Servers = IPADDR6_INIT_HOST(0xFF020000, 0, 0, 0x00010003);
static struct udp_pcb *dhcp6_pcb;
static u8_t dhcp6_pcb_refcount;
/* receive, unfold, parse and free incoming messages */
static void dhcp6_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port);
/** Ensure DHCP PCB is allocated and bound */
static err_t
dhcp6_inc_pcb_refcount(void)
{
if (dhcp6_pcb_refcount == 0) {
LWIP_ASSERT("dhcp6_inc_pcb_refcount(): memory leak", dhcp6_pcb == NULL);
/* allocate UDP PCB */
dhcp6_pcb = udp_new_ip6();
if (dhcp6_pcb == NULL) {
return ERR_MEM;
}
ip_set_option(dhcp6_pcb, SOF_BROADCAST);
/* set up local and remote port for the pcb -> listen on all interfaces on all src/dest IPs */
udp_bind(dhcp6_pcb, IP6_ADDR_ANY, DHCP6_CLIENT_PORT);
udp_recv(dhcp6_pcb, dhcp6_recv, NULL);
}
dhcp6_pcb_refcount++;
return ERR_OK;
}
/** Free DHCP PCB if the last netif stops using it */
static void
dhcp6_dec_pcb_refcount(void)
{
LWIP_ASSERT("dhcp6_pcb_refcount(): refcount error", (dhcp6_pcb_refcount > 0));
dhcp6_pcb_refcount--;
if (dhcp6_pcb_refcount == 0) {
udp_remove(dhcp6_pcb);
dhcp6_pcb = NULL;
}
}
/**
* @ingroup dhcp6
* Set a statically allocated struct dhcp6 to work with.
* Using this prevents dhcp6_start to allocate it using mem_malloc.
*
* @param netif the netif for which to set the struct dhcp
* @param dhcp6 (uninitialised) dhcp6 struct allocated by the application
*/
void
dhcp6_set_struct(struct netif *netif, struct dhcp6 *dhcp6)
{
LWIP_ASSERT("netif != NULL", netif != NULL);
LWIP_ASSERT("dhcp6 != NULL", dhcp6 != NULL);
LWIP_ASSERT("netif already has a struct dhcp6 set", netif_dhcp6_data(netif) == NULL);
/* clear data structure */
memset(dhcp6, 0, sizeof(struct dhcp6));
/* dhcp6_set_state(&dhcp, DHCP6_STATE_OFF); */
netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP6, dhcp6);
}
/**
* @ingroup dhcp6
* Removes a struct dhcp6 from a netif.
*
* ATTENTION: Only use this when not using dhcp6_set_struct() to allocate the
* struct dhcp6 since the memory is passed back to the heap.
*
* @param netif the netif from which to remove the struct dhcp
*/
void dhcp6_cleanup(struct netif *netif)
{
LWIP_ASSERT("netif != NULL", netif != NULL);
if (netif_dhcp6_data(netif) != NULL) {
mem_free(netif_dhcp6_data(netif));
netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP6, NULL);
}
}
static struct dhcp6*
dhcp6_get_struct(struct netif *netif, const char *dbg_requester)
{
struct dhcp6 *dhcp6 = netif_dhcp6_data(netif);
if (dhcp6 == NULL) {
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE, ("%s: mallocing new DHCPv6 client\n", dbg_requester));
dhcp6 = (struct dhcp6 *)mem_malloc(sizeof(struct dhcp6));
if (dhcp6 == NULL) {
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE, ("%s: could not allocate dhcp6\n", dbg_requester));
return NULL;
}
/* clear data structure, this implies DHCP6_STATE_OFF */
memset(dhcp6, 0, sizeof(struct dhcp6));
/* store this dhcp6 client in the netif */
netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP6, dhcp6);
} else {
/* already has DHCP6 client attached */
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("%s: using existing DHCPv6 client\n", dbg_requester));
}
if (!dhcp6->pcb_allocated) {
if (dhcp6_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP6 PCB is allocated */
mem_free(dhcp6);
netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP6, NULL);
return NULL;
}
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE, ("%s: allocated dhcp6", dbg_requester));
dhcp6->pcb_allocated = 1;
}
return dhcp6;
}
/*
* Set the DHCPv6 state
* If the state changed, reset the number of tries.
*/
static void
dhcp6_set_state(struct dhcp6 *dhcp6, u8_t new_state, const char *dbg_caller)
{
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("DHCPv6 state: %d -> %d (%s)\n",
dhcp6->state, new_state, dbg_caller));
if (new_state != dhcp6->state) {
dhcp6->state = new_state;
dhcp6->tries = 0;
dhcp6->request_timeout = 0;
}
}
static int
dhcp6_stateless_enabled(struct dhcp6 *dhcp6)
{
if ((dhcp6->state == DHCP6_STATE_STATELESS_IDLE) ||
(dhcp6->state == DHCP6_STATE_REQUESTING_CONFIG)) {
return 1;
}
return 0;
}
/*static int
dhcp6_stateful_enabled(struct dhcp6 *dhcp6)
{
if (dhcp6->state == DHCP6_STATE_OFF) {
return 0;
}
if (dhcp6_stateless_enabled(dhcp6)) {
return 0;
}
return 1;
}*/
/**
* @ingroup dhcp6
* Enable stateful DHCPv6 on this netif
* Requests are sent on receipt of an RA message with the
* ND6_RA_FLAG_MANAGED_ADDR_CONFIG flag set.
*
* A struct dhcp6 will be allocated for this netif if not
* set via @ref dhcp6_set_struct before.
*
* @todo: stateful DHCPv6 not supported, yet
*/
err_t
dhcp6_enable_stateful(struct netif *netif)
{
LWIP_UNUSED_ARG(netif);
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE, ("stateful dhcp6 not implemented yet"));
return ERR_VAL;
}
/**
* @ingroup dhcp6
* Enable stateless DHCPv6 on this netif
* Requests are sent on receipt of an RA message with the
* ND6_RA_FLAG_OTHER_CONFIG flag set.
*
* A struct dhcp6 will be allocated for this netif if not
* set via @ref dhcp6_set_struct before.
*/
err_t
dhcp6_enable_stateless(struct netif *netif)
{
struct dhcp6 *dhcp6;
LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp6_enable_stateless(netif=%p) %c%c%"U16_F"\n", (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num));
dhcp6 = dhcp6_get_struct(netif, "dhcp6_enable_stateless()");
if (dhcp6 == NULL) {
return ERR_MEM;
}
if (dhcp6_stateless_enabled(dhcp6)) {
LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp6_enable_stateless(): stateless DHCPv6 already enabled"));
return ERR_OK;
} else if (dhcp6->state != DHCP6_STATE_OFF) {
/* stateful running */
/* @todo: stop stateful once it is implemented */
LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp6_enable_stateless(): switching from stateful to stateless DHCPv6"));
}
LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp6_enable_stateless(): stateless DHCPv6 enabled\n"));
dhcp6_set_state(dhcp6, DHCP6_STATE_STATELESS_IDLE, "dhcp6_enable_stateless");
return ERR_OK;
}
/**
* @ingroup dhcp6
* Disable stateful or stateless DHCPv6 on this netif
* Requests are sent on receipt of an RA message with the
* ND6_RA_FLAG_OTHER_CONFIG flag set.
*/
void
dhcp6_disable(struct netif *netif)
{
struct dhcp6 *dhcp6;
LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp6_disable(netif=%p) %c%c%"U16_F"\n", (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num));
dhcp6 = netif_dhcp6_data(netif);
if (dhcp6 != NULL) {
if (dhcp6->state != DHCP6_STATE_OFF) {
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE, ("dhcp6_disable(): DHCPv6 disabled (old state: %s)\n",
(dhcp6_stateless_enabled(dhcp6) ? "stateless" : "stateful")));
dhcp6_set_state(dhcp6, DHCP6_STATE_OFF, "dhcp6_disable");
if (dhcp6->pcb_allocated != 0) {
dhcp6_dec_pcb_refcount(); /* free DHCPv6 PCB if not needed any more */
dhcp6->pcb_allocated = 0;
}
}
}
}
/**
* Create a DHCPv6 request, fill in common headers
*
* @param netif the netif under DHCPv6 control
* @param dhcp6 dhcp6 control struct
* @param message_type message type of the request
* @param opt_len_alloc option length to allocate
* @param options_out_len option length on exit
* @return a pbuf for the message
*/
static struct pbuf *
dhcp6_create_msg(struct netif *netif, struct dhcp6 *dhcp6, u8_t message_type,
u16_t opt_len_alloc, u16_t *options_out_len)
{
struct pbuf *p_out;
struct dhcp6_msg *msg_out;
LWIP_ERROR("dhcp6_create_msg: netif != NULL", (netif != NULL), return NULL;);
LWIP_ERROR("dhcp6_create_msg: dhcp6 != NULL", (dhcp6 != NULL), return NULL;);
p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp6_msg) + opt_len_alloc, PBUF_RAM);
if (p_out == NULL) {
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
("dhcp6_create_msg(): could not allocate pbuf\n"));
return NULL;
}
LWIP_ASSERT("dhcp6_create_msg: check that first pbuf can hold struct dhcp6_msg",
(p_out->len >= sizeof(struct dhcp6_msg) + opt_len_alloc));
/* @todo: limit new xid for certain message types? */
/* reuse transaction identifier in retransmissions */
if (dhcp6->tries == 0) {
dhcp6->xid = LWIP_RAND() & 0xFFFFFF;
}
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE,
("transaction id xid(%"X32_F")\n", dhcp6->xid));
msg_out = (struct dhcp6_msg *)p_out->payload;
memset(msg_out, 0, sizeof(struct dhcp6_msg) + opt_len_alloc);
msg_out->msgtype = message_type;
msg_out->transaction_id[0] = (u8_t)(dhcp6->xid >> 16);
msg_out->transaction_id[1] = (u8_t)(dhcp6->xid >> 8);
msg_out->transaction_id[2] = (u8_t)dhcp6->xid;
*options_out_len = 0;
return p_out;
}
static u16_t
dhcp6_option_short(u16_t options_out_len, u8_t *options, u16_t value)
{
options[options_out_len++] = (u8_t)((value & 0xff00U) >> 8);
options[options_out_len++] = (u8_t) (value & 0x00ffU);
return options_out_len;
}
static u16_t
dhcp6_option_optionrequest(u16_t options_out_len, u8_t *options, const u16_t *req_options,
u16_t num_req_options, u16_t max_len)
{
size_t i;
u16_t ret;
LWIP_ASSERT("dhcp6_option_optionrequest: options_out_len + sizeof(struct dhcp6_msg) + addlen <= max_len",
sizeof(struct dhcp6_msg) + options_out_len + 4U + (2U * num_req_options) <= max_len);
LWIP_UNUSED_ARG(max_len);
ret = dhcp6_option_short(options_out_len, options, DHCP6_OPTION_ORO);
ret = dhcp6_option_short(ret, options, 2 * num_req_options);
for (i = 0; i < num_req_options; i++) {
ret = dhcp6_option_short(ret, options, req_options[i]);
}
return ret;
}
/* All options are added, shrink the pbuf to the required size */
static void
dhcp6_msg_finalize(u16_t options_out_len, struct pbuf *p_out)
{
/* shrink the pbuf to the actual content length */
pbuf_realloc(p_out, (u16_t)(sizeof(struct dhcp6_msg) + options_out_len));
}
#if LWIP_IPV6_DHCP6_STATELESS
static void
dhcp6_information_request(struct netif *netif, struct dhcp6 *dhcp6)
{
const u16_t requested_options[] = {
#if LWIP_DHCP6_PROVIDE_DNS_SERVERS
DHCP6_OPTION_DNS_SERVERS,
DHCP6_OPTION_DOMAIN_LIST
#endif
#if LWIP_DHCP6_GET_NTP_SRV
, DHCP6_OPTION_SNTP_SERVERS
#endif
};
u16_t msecs;
struct pbuf *p_out;
u16_t options_out_len;
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE, ("dhcp6_information_request()\n"));
/* create and initialize the DHCP message header */
p_out = dhcp6_create_msg(netif, dhcp6, DHCP6_INFOREQUEST, 4 + sizeof(requested_options), &options_out_len);
if (p_out != NULL) {
err_t err;
struct dhcp6_msg *msg_out = (struct dhcp6_msg *)p_out->payload;
u8_t *options = (u8_t *)(msg_out + 1);
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE, ("dhcp6_information_request: making request\n"));
options_out_len = dhcp6_option_optionrequest(options_out_len, options, requested_options,
LWIP_ARRAYSIZE(requested_options), p_out->len);
LWIP_HOOK_DHCP6_APPEND_OPTIONS(netif, dhcp6, DHCP6_STATE_REQUESTING_CONFIG, msg_out,
DHCP6_INFOREQUEST, options_out_len, p_out->len);
dhcp6_msg_finalize(options_out_len, p_out);
err = udp_sendto_if(dhcp6_pcb, p_out, &dhcp6_All_DHCP6_Relay_Agents_and_Servers, DHCP6_SERVER_PORT, netif);
pbuf_free(p_out);
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp6_information_request: INFOREQUESTING -> %d\n", (int)err));
LWIP_UNUSED_ARG(err);
} else {
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp6_information_request: could not allocate DHCP6 request\n"));
}
dhcp6_set_state(dhcp6, DHCP6_STATE_REQUESTING_CONFIG, "dhcp6_information_request");
if (dhcp6->tries < 255) {
dhcp6->tries++;
}
msecs = (u16_t)((dhcp6->tries < 6 ? 1 << dhcp6->tries : 60) * 1000);
dhcp6->request_timeout = (u16_t)((msecs + DHCP6_TIMER_MSECS - 1) / DHCP6_TIMER_MSECS);
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp6_information_request(): set request timeout %"U16_F" msecs\n", msecs));
}
static err_t
dhcp6_request_config(struct netif *netif, struct dhcp6 *dhcp6)
{
/* stateless mode enabled and no request running? */
if (dhcp6->state == DHCP6_STATE_STATELESS_IDLE) {
/* send Information-request and wait for answer; setup receive timeout */
dhcp6_information_request(netif, dhcp6);
}
return ERR_OK;
}
static void
dhcp6_abort_config_request(struct dhcp6 *dhcp6)
{
if (dhcp6->state == DHCP6_STATE_REQUESTING_CONFIG) {
/* abort running request */
dhcp6_set_state(dhcp6, DHCP6_STATE_STATELESS_IDLE, "dhcp6_abort_config_request");
}
}
/* Handle a REPLY to INFOREQUEST
* This parses DNS and NTP server addresses from the reply.
*/
static void
dhcp6_handle_config_reply(struct netif *netif, struct pbuf *p_msg_in)
{
struct dhcp6 *dhcp6 = netif_dhcp6_data(netif);
LWIP_UNUSED_ARG(dhcp6);
LWIP_UNUSED_ARG(p_msg_in);
#if LWIP_DHCP6_PROVIDE_DNS_SERVERS
if (dhcp6_option_given(dhcp6, DHCP6_OPTION_IDX_DNS_SERVER)) {
ip_addr_t dns_addr;
ip6_addr_t *dns_addr6;
u16_t op_start = dhcp6_get_option_start(dhcp6, DHCP6_OPTION_IDX_DNS_SERVER);
u16_t op_len = dhcp6_get_option_length(dhcp6, DHCP6_OPTION_IDX_DNS_SERVER);
u16_t idx;
u8_t n;
ip_addr_set_zero_ip6(&dns_addr);
dns_addr6 = ip_2_ip6(&dns_addr);
for (n = 0, idx = op_start; (idx < op_start + op_len) && (n < LWIP_DHCP6_PROVIDE_DNS_SERVERS);
n++, idx += sizeof(struct ip6_addr_packed)) {
u16_t copied = pbuf_copy_partial(p_msg_in, dns_addr6, sizeof(struct ip6_addr_packed), idx);
if (copied != sizeof(struct ip6_addr_packed)) {
/* pbuf length mismatch */
return;
}
ip6_addr_assign_zone(dns_addr6, IP6_UNKNOWN, netif);
/* @todo: do we need a different offset than DHCP(v4)? */
dns_setserver(n, &dns_addr);
}
}
/* @ todo: parse and set Domain Search List */
#endif /* LWIP_DHCP6_PROVIDE_DNS_SERVERS */
#if LWIP_DHCP6_GET_NTP_SRV
if (dhcp6_option_given(dhcp6, DHCP6_OPTION_IDX_NTP_SERVER)) {
ip_addr_t ntp_server_addrs[LWIP_DHCP6_MAX_NTP_SERVERS];
u16_t op_start = dhcp6_get_option_start(dhcp6, DHCP6_OPTION_IDX_NTP_SERVER);
u16_t op_len = dhcp6_get_option_length(dhcp6, DHCP6_OPTION_IDX_NTP_SERVER);
u16_t idx;
u8_t n;
for (n = 0, idx = op_start; (idx < op_start + op_len) && (n < LWIP_DHCP6_MAX_NTP_SERVERS);
n++, idx += sizeof(struct ip6_addr_packed)) {
u16_t copied;
ip6_addr_t *ntp_addr6 = ip_2_ip6(&ntp_server_addrs[n]);
ip_addr_set_zero_ip6(&ntp_server_addrs[n]);
copied = pbuf_copy_partial(p_msg_in, ntp_addr6, sizeof(struct ip6_addr_packed), idx);
if (copied != sizeof(struct ip6_addr_packed)) {
/* pbuf length mismatch */
return;
}
ip6_addr_assign_zone(ntp_addr6, IP6_UNKNOWN, netif);
}
dhcp6_set_ntp_servers(n, ntp_server_addrs);
}
#endif /* LWIP_DHCP6_GET_NTP_SRV */
}
#endif /* LWIP_IPV6_DHCP6_STATELESS */
/** This function is called from nd6 module when an RA messsage is received
* It triggers DHCPv6 requests (if enabled).
*/
void
dhcp6_nd6_ra_trigger(struct netif *netif, u8_t managed_addr_config, u8_t other_config)
{
struct dhcp6 *dhcp6;
LWIP_ASSERT("netif != NULL", netif != NULL);
dhcp6 = netif_dhcp6_data(netif);
LWIP_UNUSED_ARG(managed_addr_config);
LWIP_UNUSED_ARG(other_config);
LWIP_UNUSED_ARG(dhcp6);
#if LWIP_IPV6_DHCP6_STATELESS
if (dhcp6 != NULL) {
if (dhcp6_stateless_enabled(dhcp6)) {
if (other_config) {
dhcp6_request_config(netif, dhcp6);
} else {
dhcp6_abort_config_request(dhcp6);
}
}
}
#endif /* LWIP_IPV6_DHCP6_STATELESS */
}
/**
* Parse the DHCPv6 message and extract the DHCPv6 options.
*
* Extract the DHCPv6 options (offset + length) so that we can later easily
* check for them or extract the contents.
*/
static err_t
dhcp6_parse_reply(struct pbuf *p, struct dhcp6 *dhcp6)
{
u16_t offset;
u16_t offset_max;
u16_t options_idx;
struct dhcp6_msg *msg_in;
LWIP_UNUSED_ARG(dhcp6);
/* clear received options */
dhcp6_clear_all_options(dhcp6);
msg_in = (struct dhcp6_msg *)p->payload;
/* parse options */
options_idx = sizeof(struct dhcp6_msg);
/* parse options to the end of the received packet */
offset_max = p->tot_len;
offset = options_idx;
/* at least 4 byte to read? */
while ((offset + 4 <= offset_max)) {
u8_t op_len_buf[4];
u8_t *op_len;
u16_t op;
u16_t len;
u16_t val_offset = (u16_t)(offset + 4);
if (val_offset < offset) {
/* overflow */
return ERR_BUF;
}
/* copy option + length, might be split accross pbufs */
op_len = (u8_t *)pbuf_get_contiguous(p, op_len_buf, 4, 4, offset);
if (op_len == NULL) {
/* failed to get option and length */
return ERR_VAL;
}
op = (op_len[0] << 8) | op_len[1];
len = (op_len[2] << 8) | op_len[3];
offset = val_offset + len;
if (offset < val_offset) {
/* overflow */
return ERR_BUF;
}
switch (op) {
case (DHCP6_OPTION_CLIENTID):
dhcp6_got_option(dhcp6, DHCP6_OPTION_IDX_CLI_ID);
dhcp6_set_option(dhcp6, DHCP6_OPTION_IDX_CLI_ID, val_offset, len);
break;
case (DHCP6_OPTION_SERVERID):
dhcp6_got_option(dhcp6, DHCP6_OPTION_IDX_SERVER_ID);
dhcp6_set_option(dhcp6, DHCP6_OPTION_IDX_SERVER_ID, val_offset, len);
break;
#if LWIP_DHCP6_PROVIDE_DNS_SERVERS
case (DHCP6_OPTION_DNS_SERVERS):
dhcp6_got_option(dhcp6, DHCP6_OPTION_IDX_DNS_SERVER);
dhcp6_set_option(dhcp6, DHCP6_OPTION_IDX_DNS_SERVER, val_offset, len);
break;
case (DHCP6_OPTION_DOMAIN_LIST):
dhcp6_got_option(dhcp6, DHCP6_OPTION_IDX_DOMAIN_LIST);
dhcp6_set_option(dhcp6, DHCP6_OPTION_IDX_DOMAIN_LIST, val_offset, len);
break;
#endif /* LWIP_DHCP6_PROVIDE_DNS_SERVERS */
#if LWIP_DHCP6_GET_NTP_SRV
case (DHCP6_OPTION_SNTP_SERVERS):
dhcp6_got_option(dhcp6, DHCP6_OPTION_IDX_NTP_SERVER);
dhcp6_set_option(dhcp6, DHCP6_OPTION_IDX_NTP_SERVER, val_offset, len);
break;
#endif /* LWIP_DHCP6_GET_NTP_SRV*/
default:
LWIP_DEBUGF(DHCP6_DEBUG, ("skipping option %"U16_F" in options\n", op));
LWIP_HOOK_DHCP6_PARSE_OPTION(ip_current_netif(), dhcp6, dhcp6->state, msg_in,
msg_in->msgtype, op, len, q, val_offset);
break;
}
}
return ERR_OK;
}
static void
dhcp6_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port)
{
struct netif *netif = ip_current_input_netif();
struct dhcp6 *dhcp6 = netif_dhcp6_data(netif);
struct dhcp6_msg *reply_msg = (struct dhcp6_msg *)p->payload;
u8_t msg_type;
u32_t xid;
LWIP_UNUSED_ARG(arg);
/* Caught DHCPv6 message from netif that does not have DHCPv6 enabled? -> not interested */
if ((dhcp6 == NULL) || (dhcp6->pcb_allocated == 0)) {
goto free_pbuf_and_return;
}
LWIP_ERROR("invalid server address type", IP_IS_V6(addr), goto free_pbuf_and_return;);
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE, ("dhcp6_recv(pbuf = %p) from DHCPv6 server %s port %"U16_F"\n", (void *)p,
ipaddr_ntoa(addr), port));
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len));
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len));
/* prevent warnings about unused arguments */
LWIP_UNUSED_ARG(pcb);
LWIP_UNUSED_ARG(addr);
LWIP_UNUSED_ARG(port);
if (p->len < sizeof(struct dhcp6_msg)) {
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCPv6 reply message or pbuf too short\n"));
goto free_pbuf_and_return;
}
/* match transaction ID against what we expected */
xid = reply_msg->transaction_id[0] << 16;
xid |= reply_msg->transaction_id[1] << 8;
xid |= reply_msg->transaction_id[2];
if (xid != dhcp6->xid) {
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING,
("transaction id mismatch reply_msg->xid(%"X32_F")!= dhcp6->xid(%"X32_F")\n", xid, dhcp6->xid));
goto free_pbuf_and_return;
}
/* option fields could be unfold? */
if (dhcp6_parse_reply(p, dhcp6) != ERR_OK) {
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
("problem unfolding DHCPv6 message - too short on memory?\n"));
goto free_pbuf_and_return;
}
/* read DHCP message type */
msg_type = reply_msg->msgtype;
/* message type is DHCP6 REPLY? */
if (msg_type == DHCP6_REPLY) {
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE, ("DHCP6_REPLY received\n"));
#if LWIP_IPV6_DHCP6_STATELESS
/* in info-requesting state? */
if (dhcp6->state == DHCP6_STATE_REQUESTING_CONFIG) {
dhcp6_set_state(dhcp6, DHCP6_STATE_STATELESS_IDLE, "dhcp6_recv");
dhcp6_handle_config_reply(netif, p);
} else
#endif /* LWIP_IPV6_DHCP6_STATELESS */
{
/* @todo: handle reply in other states? */
}
} else {
/* @todo: handle other message types */
}
free_pbuf_and_return:
pbuf_free(p);
}
/**
* A DHCPv6 request has timed out.
*
* The timer that was started with the DHCPv6 request has
* timed out, indicating no response was received in time.
*/
static void
dhcp6_timeout(struct netif *netif, struct dhcp6 *dhcp6)
{
LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp6_timeout()\n"));
LWIP_UNUSED_ARG(netif);
LWIP_UNUSED_ARG(dhcp6);
#if LWIP_IPV6_DHCP6_STATELESS
/* back-off period has passed, or server selection timed out */
if (dhcp6->state == DHCP6_STATE_REQUESTING_CONFIG) {
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE, ("dhcp6_timeout(): retrying information request\n"));
dhcp6_information_request(netif, dhcp6);
}
#endif /* LWIP_IPV6_DHCP6_STATELESS */
}
/**
* DHCPv6 timeout handling (this function must be called every 500ms,
* see @ref DHCP6_TIMER_MSECS).
*
* A DHCPv6 server is expected to respond within a short period of time.
* This timer checks whether an outstanding DHCPv6 request is timed out.
*/
void
dhcp6_tmr(void)
{
struct netif *netif;
/* loop through netif's */
NETIF_FOREACH(netif) {
struct dhcp6 *dhcp6 = netif_dhcp6_data(netif);
/* only act on DHCPv6 configured interfaces */
if (dhcp6 != NULL) {
/* timer is active (non zero), and is about to trigger now */
if (dhcp6->request_timeout > 1) {
dhcp6->request_timeout--;
} else if (dhcp6->request_timeout == 1) {
dhcp6->request_timeout--;
/* { dhcp6->request_timeout == 0 } */
LWIP_DEBUGF(DHCP6_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp6_tmr(): request timeout\n"));
/* this client's request timeout triggered */
dhcp6_timeout(netif, dhcp6);
}
}
}
}
#endif /* LWIP_IPV6 && LWIP_IPV6_DHCP6 */