diff options
Diffstat (limited to 'lwip/src/core/ipv6/dhcp6.c')
| -rw-r--r-- | lwip/src/core/ipv6/dhcp6.c | 812 |
1 files changed, 812 insertions, 0 deletions
diff --git a/lwip/src/core/ipv6/dhcp6.c b/lwip/src/core/ipv6/dhcp6.c new file mode 100644 index 0000000..7cf98a5 --- /dev/null +++ b/lwip/src/core/ipv6/dhcp6.c @@ -0,0 +1,812 @@ +/** + * @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[] = {DHCP6_OPTION_DNS_SERVERS, DHCP6_OPTION_DOMAIN_LIST, DHCP6_OPTION_SNTP_SERVERS}; + 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; + + memset(&dns_addr, 0, sizeof(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 */ |