diff options
Diffstat (limited to 'lwip/src/core/ipv4/dhcp.c')
| -rw-r--r-- | lwip/src/core/ipv4/dhcp.c | 1990 |
1 files changed, 1990 insertions, 0 deletions
diff --git a/lwip/src/core/ipv4/dhcp.c b/lwip/src/core/ipv4/dhcp.c new file mode 100644 index 0000000..534574f --- /dev/null +++ b/lwip/src/core/ipv4/dhcp.c @@ -0,0 +1,1990 @@ +/** + * @file + * Dynamic Host Configuration Protocol client + * + * @defgroup dhcp4 DHCPv4 + * @ingroup ip4 + * DHCP (IPv4) related functions + * This is a DHCP client for the lwIP TCP/IP stack. It aims to conform + * with RFC 2131 and RFC 2132. + * + * @todo: + * - Support for interfaces other than Ethernet (SLIP, PPP, ...) + * + * Options: + * @ref DHCP_COARSE_TIMER_SECS (recommended 60 which is a minute) + * @ref DHCP_FINE_TIMER_MSECS (recommended 500 which equals TCP coarse timer) + * + * dhcp_start() starts a DHCP client instance which + * configures the interface by obtaining an IP address lease and maintaining it. + * + * Use dhcp_release() to end the lease and use dhcp_stop() + * to remove the DHCP client. + * + * @see LWIP_HOOK_DHCP_APPEND_OPTIONS + * @see LWIP_HOOK_DHCP_PARSE_OPTION + * + * @see netifapi_dhcp4 + */ + +/* + * Copyright (c) 2001-2004 Leon Woestenberg <leon.woestenberg@gmx.net> + * Copyright (c) 2001-2004 Axon Digital Design B.V., The Netherlands. + * 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. + * The Swedish Institute of Computer Science and Adam Dunkels + * are specifically granted permission to redistribute this + * source code. + * + * Author: Leon Woestenberg <leon.woestenberg@gmx.net> + * + */ + +#include "lwip/opt.h" + +#if LWIP_IPV4 && LWIP_DHCP /* don't build if not configured for use in lwipopts.h */ + +#include "lwip/stats.h" +#include "lwip/mem.h" +#include "lwip/udp.h" +#include "lwip/ip_addr.h" +#include "lwip/netif.h" +#include "lwip/def.h" +#include "lwip/dhcp.h" +#include "lwip/autoip.h" +#include "lwip/dns.h" +#include "lwip/etharp.h" +#include "lwip/prot/dhcp.h" +#include "lwip/prot/iana.h" + +#include <string.h> + +#ifdef LWIP_HOOK_FILENAME +#include LWIP_HOOK_FILENAME +#endif +#ifndef LWIP_HOOK_DHCP_APPEND_OPTIONS +#define LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, state, msg, msg_type, options_len_ptr) +#endif +#ifndef LWIP_HOOK_DHCP_PARSE_OPTION +#define LWIP_HOOK_DHCP_PARSE_OPTION(netif, dhcp, state, msg, msg_type, option, len, pbuf, offset) do { LWIP_UNUSED_ARG(msg); } while(0) +#endif + +/** DHCP_CREATE_RAND_XID: if this is set to 1, the xid is created using + * LWIP_RAND() (this overrides DHCP_GLOBAL_XID) + */ +#ifndef DHCP_CREATE_RAND_XID +#define DHCP_CREATE_RAND_XID 1 +#endif + +/** Default for DHCP_GLOBAL_XID is 0xABCD0000 + * This can be changed by defining DHCP_GLOBAL_XID and DHCP_GLOBAL_XID_HEADER, e.g. + * \#define DHCP_GLOBAL_XID_HEADER "stdlib.h" + * \#define DHCP_GLOBAL_XID rand() + */ +#ifdef DHCP_GLOBAL_XID_HEADER +#include DHCP_GLOBAL_XID_HEADER /* include optional starting XID generation prototypes */ +#endif + +/** DHCP_OPTION_MAX_MSG_SIZE is set to the MTU + * MTU is checked to be big enough in dhcp_start */ +#define DHCP_MAX_MSG_LEN(netif) (netif->mtu) +#define DHCP_MAX_MSG_LEN_MIN_REQUIRED 576 +/** Minimum length for reply before packet is parsed */ +#define DHCP_MIN_REPLY_LEN 44 + +#define REBOOT_TRIES 2 + +#if LWIP_DNS && LWIP_DHCP_MAX_DNS_SERVERS +#if DNS_MAX_SERVERS > LWIP_DHCP_MAX_DNS_SERVERS +#define LWIP_DHCP_PROVIDE_DNS_SERVERS LWIP_DHCP_MAX_DNS_SERVERS +#else +#define LWIP_DHCP_PROVIDE_DNS_SERVERS DNS_MAX_SERVERS +#endif +#else +#define LWIP_DHCP_PROVIDE_DNS_SERVERS 0 +#endif + +/** Option handling: options are parsed in dhcp_parse_reply + * and saved in an array where other functions can load them from. + * This might be moved into the struct dhcp (not necessarily since + * lwIP is single-threaded and the array is only used while in recv + * callback). */ +enum dhcp_option_idx { + DHCP_OPTION_IDX_OVERLOAD = 0, + DHCP_OPTION_IDX_MSG_TYPE, + DHCP_OPTION_IDX_SERVER_ID, + DHCP_OPTION_IDX_LEASE_TIME, + DHCP_OPTION_IDX_T1, + DHCP_OPTION_IDX_T2, + DHCP_OPTION_IDX_SUBNET_MASK, + DHCP_OPTION_IDX_ROUTER, +#if LWIP_DHCP_PROVIDE_DNS_SERVERS + DHCP_OPTION_IDX_DNS_SERVER, + DHCP_OPTION_IDX_DNS_SERVER_LAST = DHCP_OPTION_IDX_DNS_SERVER + LWIP_DHCP_PROVIDE_DNS_SERVERS - 1, +#endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ +#if LWIP_DHCP_GET_NTP_SRV + DHCP_OPTION_IDX_NTP_SERVER, + DHCP_OPTION_IDX_NTP_SERVER_LAST = DHCP_OPTION_IDX_NTP_SERVER + LWIP_DHCP_MAX_NTP_SERVERS - 1, +#endif /* LWIP_DHCP_GET_NTP_SRV */ + DHCP_OPTION_IDX_MAX +}; + +/** Holds the decoded option values, only valid while in dhcp_recv. + @todo: move this into struct dhcp? */ +u32_t dhcp_rx_options_val[DHCP_OPTION_IDX_MAX]; +/** Holds a flag which option was received and is contained in dhcp_rx_options_val, + only valid while in dhcp_recv. + @todo: move this into struct dhcp? */ +u8_t dhcp_rx_options_given[DHCP_OPTION_IDX_MAX]; + +static u8_t dhcp_discover_request_options[] = { + DHCP_OPTION_SUBNET_MASK, + DHCP_OPTION_ROUTER, + DHCP_OPTION_BROADCAST +#if LWIP_DHCP_PROVIDE_DNS_SERVERS + , DHCP_OPTION_DNS_SERVER +#endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ +#if LWIP_DHCP_GET_NTP_SRV + , DHCP_OPTION_NTP +#endif /* LWIP_DHCP_GET_NTP_SRV */ +}; + +#ifdef DHCP_GLOBAL_XID +static u32_t xid; +static u8_t xid_initialised; +#endif /* DHCP_GLOBAL_XID */ + +#define dhcp_option_given(dhcp, idx) (dhcp_rx_options_given[idx] != 0) +#define dhcp_got_option(dhcp, idx) (dhcp_rx_options_given[idx] = 1) +#define dhcp_clear_option(dhcp, idx) (dhcp_rx_options_given[idx] = 0) +#define dhcp_clear_all_options(dhcp) (memset(dhcp_rx_options_given, 0, sizeof(dhcp_rx_options_given))) +#define dhcp_get_option_value(dhcp, idx) (dhcp_rx_options_val[idx]) +#define dhcp_set_option_value(dhcp, idx, val) (dhcp_rx_options_val[idx] = (val)) + +static struct udp_pcb *dhcp_pcb; +static u8_t dhcp_pcb_refcount; + +/* DHCP client state machine functions */ +static err_t dhcp_discover(struct netif *netif); +static err_t dhcp_select(struct netif *netif); +static void dhcp_bind(struct netif *netif); +#if DHCP_DOES_ARP_CHECK +static err_t dhcp_decline(struct netif *netif); +#endif /* DHCP_DOES_ARP_CHECK */ +static err_t dhcp_rebind(struct netif *netif); +static err_t dhcp_reboot(struct netif *netif); +static void dhcp_set_state(struct dhcp *dhcp, u8_t new_state); + +/* receive, unfold, parse and free incoming messages */ +static void dhcp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port); + +/* set the DHCP timers */ +static void dhcp_timeout(struct netif *netif); +static void dhcp_t1_timeout(struct netif *netif); +static void dhcp_t2_timeout(struct netif *netif); + +/* build outgoing messages */ +/* create a DHCP message, fill in common headers */ +static struct pbuf *dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type, u16_t *options_out_len); +/* add a DHCP option (type, then length in bytes) */ +static u16_t dhcp_option(u16_t options_out_len, u8_t *options, u8_t option_type, u8_t option_len); +/* add option values */ +static u16_t dhcp_option_byte(u16_t options_out_len, u8_t *options, u8_t value); +static u16_t dhcp_option_short(u16_t options_out_len, u8_t *options, u16_t value); +static u16_t dhcp_option_long(u16_t options_out_len, u8_t *options, u32_t value); +#if LWIP_NETIF_HOSTNAME +static u16_t dhcp_option_hostname(u16_t options_out_len, u8_t *options, struct netif *netif); +#endif /* LWIP_NETIF_HOSTNAME */ +/* always add the DHCP options trailer to end and pad */ +static void dhcp_option_trailer(u16_t options_out_len, u8_t *options, struct pbuf *p_out); + +/** Ensure DHCP PCB is allocated and bound */ +static err_t +dhcp_inc_pcb_refcount(void) +{ + if (dhcp_pcb_refcount == 0) { + LWIP_ASSERT("dhcp_inc_pcb_refcount(): memory leak", dhcp_pcb == NULL); + + /* allocate UDP PCB */ + dhcp_pcb = udp_new(); + + if (dhcp_pcb == NULL) { + return ERR_MEM; + } + + ip_set_option(dhcp_pcb, SOF_BROADCAST); + + /* set up local and remote port for the pcb -> listen on all interfaces on all src/dest IPs */ + udp_bind(dhcp_pcb, IP4_ADDR_ANY, LWIP_IANA_PORT_DHCP_CLIENT); + udp_connect(dhcp_pcb, IP4_ADDR_ANY, LWIP_IANA_PORT_DHCP_SERVER); + udp_recv(dhcp_pcb, dhcp_recv, NULL); + } + + dhcp_pcb_refcount++; + + return ERR_OK; +} + +/** Free DHCP PCB if the last netif stops using it */ +static void +dhcp_dec_pcb_refcount(void) +{ + LWIP_ASSERT("dhcp_pcb_refcount(): refcount error", (dhcp_pcb_refcount > 0)); + dhcp_pcb_refcount--; + + if (dhcp_pcb_refcount == 0) { + udp_remove(dhcp_pcb); + dhcp_pcb = NULL; + } +} + +/** + * Back-off the DHCP client (because of a received NAK response). + * + * Back-off the DHCP client because of a received NAK. Receiving a + * NAK means the client asked for something non-sensible, for + * example when it tries to renew a lease obtained on another network. + * + * We clear any existing set IP address and restart DHCP negotiation + * afresh (as per RFC2131 3.2.3). + * + * @param netif the netif under DHCP control + */ +static void +dhcp_handle_nak(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_nak(netif=%p) %c%c%"U16_F"\n", + (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); + /* Change to a defined state - set this before assigning the address + to ensure the callback can use dhcp_supplied_address() */ + dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF); + /* remove IP address from interface (must no longer be used, as per RFC2131) */ + netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4); + /* We can immediately restart discovery */ + dhcp_discover(netif); +} + +#if DHCP_DOES_ARP_CHECK +/** + * Checks if the offered IP address is already in use. + * + * It does so by sending an ARP request for the offered address and + * entering CHECKING state. If no ARP reply is received within a small + * interval, the address is assumed to be free for use by us. + * + * @param netif the netif under DHCP control + */ +static void +dhcp_check(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + err_t result; + u16_t msecs; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_check(netif=%p) %c%c\n", (void *)netif, (s16_t)netif->name[0], + (s16_t)netif->name[1])); + dhcp_set_state(dhcp, DHCP_STATE_CHECKING); + /* create an ARP query for the offered IP address, expecting that no host + responds, as the IP address should not be in use. */ + result = etharp_query(netif, &dhcp->offered_ip_addr, NULL); + if (result != ERR_OK) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_check: could not perform ARP query\n")); + } + if (dhcp->tries < 255) { + dhcp->tries++; + } + msecs = 500; + dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_check(): set request timeout %"U16_F" msecs\n", msecs)); +} +#endif /* DHCP_DOES_ARP_CHECK */ + +/** + * Remember the configuration offered by a DHCP server. + * + * @param netif the netif under DHCP control + */ +static void +dhcp_handle_offer(struct netif *netif, struct dhcp_msg *msg_in) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_handle_offer(netif=%p) %c%c%"U16_F"\n", + (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); + /* obtain the server address */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SERVER_ID)) { + dhcp->request_timeout = 0; /* stop timer */ + + ip_addr_set_ip4_u32(&dhcp->server_ip_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SERVER_ID))); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): server 0x%08"X32_F"\n", + ip4_addr_get_u32(ip_2_ip4(&dhcp->server_ip_addr)))); + /* remember offered address */ + ip4_addr_copy(dhcp->offered_ip_addr, msg_in->yiaddr); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_handle_offer(): offer for 0x%08"X32_F"\n", + ip4_addr_get_u32(&dhcp->offered_ip_addr))); + + dhcp_select(netif); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, + ("dhcp_handle_offer(netif=%p) did not get server ID!\n", (void *)netif)); + } +} + +/** + * Select a DHCP server offer out of all offers. + * + * Simply select the first offer received. + * + * @param netif the netif under DHCP control + * @return lwIP specific error (see error.h) + */ +static err_t +dhcp_select(struct netif *netif) +{ + struct dhcp *dhcp; + err_t result; + u16_t msecs; + u8_t i; + struct pbuf *p_out; + u16_t options_out_len; + + LWIP_ERROR("dhcp_select: netif != NULL", (netif != NULL), return ERR_ARG;); + dhcp = netif_dhcp_data(netif); + LWIP_ERROR("dhcp_select: dhcp != NULL", (dhcp != NULL), return ERR_VAL;); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_select(netif=%p) %c%c%"U16_F"\n", (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); + dhcp_set_state(dhcp, DHCP_STATE_REQUESTING); + + /* create and initialize the DHCP message header */ + p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif)); + + /* MUST request the offered IP address */ + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_REQUESTED_IP, 4); + options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_SERVER_ID, 4); + options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(ip_2_ip4(&dhcp->server_ip_addr)))); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); + for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { + options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]); + } + +#if LWIP_NETIF_HOSTNAME + options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif); +#endif /* LWIP_NETIF_HOSTNAME */ + + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_REQUESTING, msg_out, DHCP_REQUEST, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + /* send broadcast to any DHCP server */ + result = udp_sendto_if_src(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif, IP4_ADDR_ANY); + pbuf_free(p_out); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_select: REQUESTING\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("dhcp_select: could not allocate DHCP request\n")); + result = ERR_MEM; + } + if (dhcp->tries < 255) { + dhcp->tries++; + } + msecs = (u16_t)((dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000); + dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_select(): set request timeout %"U16_F" msecs\n", msecs)); + return result; +} + +/** + * The DHCP timer that checks for lease renewal/rebind timeouts. + * Must be called once a minute (see @ref DHCP_COARSE_TIMER_SECS). + */ +void +dhcp_coarse_tmr(void) +{ + struct netif *netif; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n")); + /* iterate through all network interfaces */ + NETIF_FOREACH(netif) { + /* only act on DHCP configured interfaces */ + struct dhcp *dhcp = netif_dhcp_data(netif); + if ((dhcp != NULL) && (dhcp->state != DHCP_STATE_OFF)) { + /* compare lease time to expire timeout */ + if (dhcp->t0_timeout && (++dhcp->lease_used == dhcp->t0_timeout)) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t0 timeout\n")); + /* this clients' lease time has expired */ + dhcp_release_and_stop(netif); + dhcp_start(netif); + /* timer is active (non zero), and triggers (zeroes) now? */ + } else if (dhcp->t2_rebind_time && (dhcp->t2_rebind_time-- == 1)) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t2 timeout\n")); + /* this clients' rebind timeout triggered */ + dhcp_t2_timeout(netif); + /* timer is active (non zero), and triggers (zeroes) now */ + } else if (dhcp->t1_renew_time && (dhcp->t1_renew_time-- == 1)) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_coarse_tmr(): t1 timeout\n")); + /* this clients' renewal timeout triggered */ + dhcp_t1_timeout(netif); + } + } + } +} + +/** + * DHCP transaction timeout handling (this function must be called every 500ms, + * see @ref DHCP_FINE_TIMER_MSECS). + * + * A DHCP server is expected to respond within a short period of time. + * This timer checks whether an outstanding DHCP request is timed out. + */ +void +dhcp_fine_tmr(void) +{ + struct netif *netif; + /* loop through netif's */ + NETIF_FOREACH(netif) { + struct dhcp *dhcp = netif_dhcp_data(netif); + /* only act on DHCP configured interfaces */ + if (dhcp != NULL) { + /* timer is active (non zero), and is about to trigger now */ + if (dhcp->request_timeout > 1) { + dhcp->request_timeout--; + } else if (dhcp->request_timeout == 1) { + dhcp->request_timeout--; + /* { dhcp->request_timeout == 0 } */ + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_fine_tmr(): request timeout\n")); + /* this client's request timeout triggered */ + dhcp_timeout(netif); + } + } + } +} + +/** + * A DHCP negotiation transaction, or ARP request, has timed out. + * + * The timer that was started with the DHCP or ARP request has + * timed out, indicating no response was received in time. + * + * @param netif the netif under DHCP control + */ +static void +dhcp_timeout(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout()\n")); + /* back-off period has passed, or server selection timed out */ + if ((dhcp->state == DHCP_STATE_BACKING_OFF) || (dhcp->state == DHCP_STATE_SELECTING)) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout(): restarting discovery\n")); + dhcp_discover(netif); + /* receiving the requested lease timed out */ + } else if (dhcp->state == DHCP_STATE_REQUESTING) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, DHCP request timed out\n")); + if (dhcp->tries <= 5) { + dhcp_select(netif); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REQUESTING, releasing, restarting\n")); + dhcp_release_and_stop(netif); + dhcp_start(netif); + } +#if DHCP_DOES_ARP_CHECK + /* received no ARP reply for the offered address (which is good) */ + } else if (dhcp->state == DHCP_STATE_CHECKING) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): CHECKING, ARP request timed out\n")); + if (dhcp->tries <= 1) { + dhcp_check(netif); + /* no ARP replies on the offered address, + looks like the IP address is indeed free */ + } else { + /* bind the interface to the offered address */ + dhcp_bind(netif); + } +#endif /* DHCP_DOES_ARP_CHECK */ + } else if (dhcp->state == DHCP_STATE_REBOOTING) { + if (dhcp->tries < REBOOT_TRIES) { + dhcp_reboot(netif); + } else { + dhcp_discover(netif); + } + } +} + +/** + * The renewal period has timed out. + * + * @param netif the netif under DHCP control + */ +static void +dhcp_t1_timeout(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_t1_timeout()\n")); + if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_BOUND) || + (dhcp->state == DHCP_STATE_RENEWING)) { + /* just retry to renew - note that the rebind timer (t2) will + * eventually time-out if renew tries fail. */ + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("dhcp_t1_timeout(): must renew\n")); + /* This slightly different to RFC2131: DHCPREQUEST will be sent from state + DHCP_STATE_RENEWING, not DHCP_STATE_BOUND */ + dhcp_renew(netif); + /* Calculate next timeout */ + if (((dhcp->t2_timeout - dhcp->lease_used) / 2) >= ((60 + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS)) { + dhcp->t1_renew_time = (u16_t)((dhcp->t2_timeout - dhcp->lease_used) / 2); + } + } +} + +/** + * The rebind period has timed out. + * + * @param netif the netif under DHCP control + */ +static void +dhcp_t2_timeout(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t2_timeout()\n")); + if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_BOUND) || + (dhcp->state == DHCP_STATE_RENEWING) || (dhcp->state == DHCP_STATE_REBINDING)) { + /* just retry to rebind */ + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, + ("dhcp_t2_timeout(): must rebind\n")); + /* This slightly different to RFC2131: DHCPREQUEST will be sent from state + DHCP_STATE_REBINDING, not DHCP_STATE_BOUND */ + dhcp_rebind(netif); + /* Calculate next timeout */ + if (((dhcp->t0_timeout - dhcp->lease_used) / 2) >= ((60 + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS)) { + dhcp->t2_rebind_time = (u16_t)((dhcp->t0_timeout - dhcp->lease_used) / 2); + } + } +} + +/** + * Handle a DHCP ACK packet + * + * @param netif the netif under DHCP control + */ +static void +dhcp_handle_ack(struct netif *netif, struct dhcp_msg *msg_in) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + +#if LWIP_DHCP_PROVIDE_DNS_SERVERS || LWIP_DHCP_GET_NTP_SRV + u8_t n; +#endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS || LWIP_DHCP_GET_NTP_SRV */ +#if LWIP_DHCP_GET_NTP_SRV + ip4_addr_t ntp_server_addrs[LWIP_DHCP_MAX_NTP_SERVERS]; +#endif + + /* clear options we might not get from the ACK */ + ip4_addr_set_zero(&dhcp->offered_sn_mask); + ip4_addr_set_zero(&dhcp->offered_gw_addr); +#if LWIP_DHCP_BOOTP_FILE + ip4_addr_set_zero(&dhcp->offered_si_addr); +#endif /* LWIP_DHCP_BOOTP_FILE */ + + /* lease time given? */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_LEASE_TIME)) { + /* remember offered lease time */ + dhcp->offered_t0_lease = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_LEASE_TIME); + } + /* renewal period given? */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T1)) { + /* remember given renewal period */ + dhcp->offered_t1_renew = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T1); + } else { + /* calculate safe periods for renewal */ + dhcp->offered_t1_renew = dhcp->offered_t0_lease / 2; + } + + /* renewal period given? */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_T2)) { + /* remember given rebind period */ + dhcp->offered_t2_rebind = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_T2); + } else { + /* calculate safe periods for rebinding (offered_t0_lease * 0.875 -> 87.5%)*/ + dhcp->offered_t2_rebind = (dhcp->offered_t0_lease * 7U) / 8U; + } + + /* (y)our internet address */ + ip4_addr_copy(dhcp->offered_ip_addr, msg_in->yiaddr); + +#if LWIP_DHCP_BOOTP_FILE + /* copy boot server address, + boot file name copied in dhcp_parse_reply if not overloaded */ + ip4_addr_copy(dhcp->offered_si_addr, msg_in->siaddr); +#endif /* LWIP_DHCP_BOOTP_FILE */ + + /* subnet mask given? */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_SUBNET_MASK)) { + /* remember given subnet mask */ + ip4_addr_set_u32(&dhcp->offered_sn_mask, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_SUBNET_MASK))); + dhcp->subnet_mask_given = 1; + } else { + dhcp->subnet_mask_given = 0; + } + + /* gateway router */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_ROUTER)) { + ip4_addr_set_u32(&dhcp->offered_gw_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_ROUTER))); + } + +#if LWIP_DHCP_GET_NTP_SRV + /* NTP servers */ + for (n = 0; (n < LWIP_DHCP_MAX_NTP_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_NTP_SERVER + n); n++) { + ip4_addr_set_u32(&ntp_server_addrs[n], lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_NTP_SERVER + n))); + } + dhcp_set_ntp_servers(n, ntp_server_addrs); +#endif /* LWIP_DHCP_GET_NTP_SRV */ + +#if LWIP_DHCP_PROVIDE_DNS_SERVERS + /* DNS servers */ + for (n = 0; (n < LWIP_DHCP_PROVIDE_DNS_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n); n++) { + ip_addr_t dns_addr; + ip_addr_set_ip4_u32_val(dns_addr, lwip_htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n))); + dns_setserver(n, &dns_addr); + } +#endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ +} + +/** + * @ingroup dhcp4 + * Set a statically allocated struct dhcp to work with. + * Using this prevents dhcp_start to allocate it using mem_malloc. + * + * @param netif the netif for which to set the struct dhcp + * @param dhcp (uninitialised) dhcp struct allocated by the application + */ +void +dhcp_set_struct(struct netif *netif, struct dhcp *dhcp) +{ + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ASSERT("netif != NULL", netif != NULL); + LWIP_ASSERT("dhcp != NULL", dhcp != NULL); + LWIP_ASSERT("netif already has a struct dhcp set", netif_dhcp_data(netif) == NULL); + + /* clear data structure */ + memset(dhcp, 0, sizeof(struct dhcp)); + /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */ + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp); +} + +/** + * @ingroup dhcp4 + * Removes a struct dhcp from a netif. + * + * ATTENTION: Only use this when not using dhcp_set_struct() to allocate the + * struct dhcp since the memory is passed back to the heap. + * + * @param netif the netif from which to remove the struct dhcp + */ +void dhcp_cleanup(struct netif *netif) +{ + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ASSERT("netif != NULL", netif != NULL); + + if (netif_dhcp_data(netif) != NULL) { + mem_free(netif_dhcp_data(netif)); + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, NULL); + } +} + +/** + * @ingroup dhcp4 + * Start DHCP negotiation for a network interface. + * + * If no DHCP client instance was attached to this interface, + * a new client is created first. If a DHCP client instance + * was already present, it restarts negotiation. + * + * @param netif The lwIP network interface + * @return lwIP error code + * - ERR_OK - No error + * - ERR_MEM - Out of memory + */ +err_t +dhcp_start(struct netif *netif) +{ + struct dhcp *dhcp; + err_t result; + + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;); + LWIP_ERROR("netif is not up, old style port?", netif_is_up(netif), return ERR_ARG;); + dhcp = netif_dhcp_data(netif); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(netif=%p) %c%c%"U16_F"\n", (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); + + /* check MTU of the netif */ + if (netif->mtu < DHCP_MAX_MSG_LEN_MIN_REQUIRED) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): Cannot use this netif with DHCP: MTU is too small\n")); + return ERR_MEM; + } + + /* no DHCP client attached yet? */ + if (dhcp == NULL) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): mallocing new DHCP client\n")); + dhcp = (struct dhcp *)mem_malloc(sizeof(struct dhcp)); + if (dhcp == NULL) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not allocate dhcp\n")); + return ERR_MEM; + } + + /* store this dhcp client in the netif */ + netif_set_client_data(netif, LWIP_NETIF_CLIENT_DATA_INDEX_DHCP, dhcp); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): allocated dhcp")); + /* already has DHCP client attached */ + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_start(): restarting DHCP configuration\n")); + + if (dhcp->pcb_allocated != 0) { + dhcp_dec_pcb_refcount(); /* free DHCP PCB if not needed any more */ + } + /* dhcp is cleared below, no need to reset flag*/ + } + + /* clear data structure */ + memset(dhcp, 0, sizeof(struct dhcp)); + /* dhcp_set_state(&dhcp, DHCP_STATE_OFF); */ + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n")); + + if (dhcp_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP PCB is allocated */ + return ERR_MEM; + } + dhcp->pcb_allocated = 1; + + if (!netif_is_link_up(netif)) { + /* set state INIT and wait for dhcp_network_changed() to call dhcp_discover() */ + dhcp_set_state(dhcp, DHCP_STATE_INIT); + return ERR_OK; + } + + /* (re)start the DHCP negotiation */ + result = dhcp_discover(netif); + if (result != ERR_OK) { + /* free resources allocated above */ + dhcp_release_and_stop(netif); + return ERR_MEM; + } + return result; +} + +/** + * @ingroup dhcp4 + * Inform a DHCP server of our manual configuration. + * + * This informs DHCP servers of our fixed IP address configuration + * by sending an INFORM message. It does not involve DHCP address + * configuration, it is just here to be nice to the network. + * + * @param netif The lwIP network interface + */ +void +dhcp_inform(struct netif *netif) +{ + struct dhcp dhcp; + struct pbuf *p_out; + u16_t options_out_len; + + LWIP_ASSERT_CORE_LOCKED(); + LWIP_ERROR("netif != NULL", (netif != NULL), return;); + + if (dhcp_inc_pcb_refcount() != ERR_OK) { /* ensure DHCP PCB is allocated */ + return; + } + + memset(&dhcp, 0, sizeof(struct dhcp)); + dhcp_set_state(&dhcp, DHCP_STATE_INFORMING); + + /* create and initialize the DHCP message header */ + p_out = dhcp_create_msg(netif, &dhcp, DHCP_INFORM, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif)); + + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, &dhcp, DHCP_STATE_INFORMING, msg_out, DHCP_INFORM, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n")); + + udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif); + + pbuf_free(p_out); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform: could not allocate DHCP request\n")); + } + + dhcp_dec_pcb_refcount(); /* delete DHCP PCB if not needed any more */ +} + +/** Handle a possible change in the network configuration. + * + * This enters the REBOOTING state to verify that the currently bound + * address is still valid. + */ +void +dhcp_network_changed(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + + if (!dhcp) { + return; + } + switch (dhcp->state) { + case DHCP_STATE_REBINDING: + case DHCP_STATE_RENEWING: + case DHCP_STATE_BOUND: + case DHCP_STATE_REBOOTING: + dhcp->tries = 0; + dhcp_reboot(netif); + break; + case DHCP_STATE_OFF: + /* stay off */ + break; + default: + LWIP_ASSERT("invalid dhcp->state", dhcp->state <= DHCP_STATE_BACKING_OFF); + /* INIT/REQUESTING/CHECKING/BACKING_OFF restart with new 'rid' because the + state changes, SELECTING: continue with current 'rid' as we stay in the + same state */ +#if LWIP_DHCP_AUTOIP_COOP + if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { + autoip_stop(netif); + dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; + } +#endif /* LWIP_DHCP_AUTOIP_COOP */ + /* ensure we start with short timeouts, even if already discovering */ + dhcp->tries = 0; + dhcp_discover(netif); + break; + } +} + +#if DHCP_DOES_ARP_CHECK +/** + * Match an ARP reply with the offered IP address: + * check whether the offered IP address is not in use using ARP + * + * @param netif the network interface on which the reply was received + * @param addr The IP address we received a reply from + */ +void +dhcp_arp_reply(struct netif *netif, const ip4_addr_t *addr) +{ + struct dhcp *dhcp; + + LWIP_ERROR("netif != NULL", (netif != NULL), return;); + dhcp = netif_dhcp_data(netif); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_arp_reply()\n")); + /* is a DHCP client doing an ARP check? */ + if ((dhcp != NULL) && (dhcp->state == DHCP_STATE_CHECKING)) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_arp_reply(): CHECKING, arp reply for 0x%08"X32_F"\n", + ip4_addr_get_u32(addr))); + /* did a host respond with the address we + were offered by the DHCP server? */ + if (ip4_addr_cmp(addr, &dhcp->offered_ip_addr)) { + /* we will not accept the offered address */ + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING, + ("dhcp_arp_reply(): arp reply matched with offered address, declining\n")); + dhcp_decline(netif); + } + } +} + +/** + * Decline an offered lease. + * + * Tell the DHCP server we do not accept the offered address. + * One reason to decline the lease is when we find out the address + * is already in use by another host (through ARP). + * + * @param netif the netif under DHCP control + */ +static err_t +dhcp_decline(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + err_t result; + u16_t msecs; + struct pbuf *p_out; + u16_t options_out_len; + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline()\n")); + dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF); + /* create and initialize the DHCP message header */ + p_out = dhcp_create_msg(netif, dhcp, DHCP_DECLINE, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_REQUESTED_IP, 4); + options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); + + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_BACKING_OFF, msg_out, DHCP_DECLINE, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + /* per section 4.4.4, broadcast DECLINE messages */ + result = udp_sendto_if_src(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif, IP4_ADDR_ANY); + pbuf_free(p_out); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_decline: BACKING OFF\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, + ("dhcp_decline: could not allocate DHCP request\n")); + result = ERR_MEM; + } + if (dhcp->tries < 255) { + dhcp->tries++; + } + msecs = 10 * 1000; + dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline(): set request timeout %"U16_F" msecs\n", msecs)); + return result; +} +#endif /* DHCP_DOES_ARP_CHECK */ + + +/** + * Start the DHCP process, discover a DHCP server. + * + * @param netif the netif under DHCP control + */ +static err_t +dhcp_discover(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + err_t result = ERR_OK; + u16_t msecs; + u8_t i; + struct pbuf *p_out; + u16_t options_out_len; + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover()\n")); + + ip4_addr_set_any(&dhcp->offered_ip_addr); + dhcp_set_state(dhcp, DHCP_STATE_SELECTING); + /* create and initialize the DHCP message header */ + p_out = dhcp_create_msg(netif, dhcp, DHCP_DISCOVER, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n")); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif)); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); + for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { + options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]); + } + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_SELECTING, msg_out, DHCP_DISCOVER, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER)\n")); + udp_sendto_if_src(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif, IP4_ADDR_ANY); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()ing\n")); + pbuf_free(p_out); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover: SELECTING\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_discover: could not allocate DHCP request\n")); + } + if (dhcp->tries < 255) { + dhcp->tries++; + } +#if LWIP_DHCP_AUTOIP_COOP + if (dhcp->tries >= LWIP_DHCP_AUTOIP_COOP_TRIES && dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_OFF) { + dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_ON; + autoip_start(netif); + } +#endif /* LWIP_DHCP_AUTOIP_COOP */ + msecs = (u16_t)((dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000); + dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_discover(): set request timeout %"U16_F" msecs\n", msecs)); + return result; +} + + +/** + * Bind the interface to the offered IP address. + * + * @param netif network interface to bind to the offered address + */ +static void +dhcp_bind(struct netif *netif) +{ + u32_t timeout; + struct dhcp *dhcp; + ip4_addr_t sn_mask, gw_addr; + LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;); + dhcp = netif_dhcp_data(netif); + LWIP_ERROR("dhcp_bind: dhcp != NULL", (dhcp != NULL), return;); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(netif=%p) %c%c%"U16_F"\n", (void *)netif, netif->name[0], netif->name[1], (u16_t)netif->num)); + + /* reset time used of lease */ + dhcp->lease_used = 0; + + if (dhcp->offered_t0_lease != 0xffffffffUL) { + /* set renewal period timer */ + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t0 renewal timer %"U32_F" secs\n", dhcp->offered_t0_lease)); + timeout = (dhcp->offered_t0_lease + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; + if (timeout > 0xffff) { + timeout = 0xffff; + } + dhcp->t0_timeout = (u16_t)timeout; + if (dhcp->t0_timeout == 0) { + dhcp->t0_timeout = 1; + } + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t0_lease * 1000)); + } + + /* temporary DHCP lease? */ + if (dhcp->offered_t1_renew != 0xffffffffUL) { + /* set renewal period timer */ + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t1 renewal timer %"U32_F" secs\n", dhcp->offered_t1_renew)); + timeout = (dhcp->offered_t1_renew + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; + if (timeout > 0xffff) { + timeout = 0xffff; + } + dhcp->t1_timeout = (u16_t)timeout; + if (dhcp->t1_timeout == 0) { + dhcp->t1_timeout = 1; + } + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t1_renew * 1000)); + dhcp->t1_renew_time = dhcp->t1_timeout; + } + /* set renewal period timer */ + if (dhcp->offered_t2_rebind != 0xffffffffUL) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_bind(): t2 rebind timer %"U32_F" secs\n", dhcp->offered_t2_rebind)); + timeout = (dhcp->offered_t2_rebind + DHCP_COARSE_TIMER_SECS / 2) / DHCP_COARSE_TIMER_SECS; + if (timeout > 0xffff) { + timeout = 0xffff; + } + dhcp->t2_timeout = (u16_t)timeout; + if (dhcp->t2_timeout == 0) { + dhcp->t2_timeout = 1; + } + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_bind(): set request timeout %"U32_F" msecs\n", dhcp->offered_t2_rebind * 1000)); + dhcp->t2_rebind_time = dhcp->t2_timeout; + } + + /* If we have sub 1 minute lease, t2 and t1 will kick in at the same time. */ + if ((dhcp->t1_timeout >= dhcp->t2_timeout) && (dhcp->t2_timeout > 0)) { + dhcp->t1_timeout = 0; + } + + if (dhcp->subnet_mask_given) { + /* copy offered network mask */ + ip4_addr_copy(sn_mask, dhcp->offered_sn_mask); + } else { + /* subnet mask not given, choose a safe subnet mask given the network class */ + u8_t first_octet = ip4_addr1(&dhcp->offered_ip_addr); + if (first_octet <= 127) { + ip4_addr_set_u32(&sn_mask, PP_HTONL(0xff000000UL)); + } else if (first_octet >= 192) { + ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffffff00UL)); + } else { + ip4_addr_set_u32(&sn_mask, PP_HTONL(0xffff0000UL)); + } + } + + ip4_addr_copy(gw_addr, dhcp->offered_gw_addr); + /* gateway address not given? */ + if (ip4_addr_isany_val(gw_addr)) { + /* copy network address */ + ip4_addr_get_network(&gw_addr, &dhcp->offered_ip_addr, &sn_mask); + /* use first host address on network as gateway */ + ip4_addr_set_u32(&gw_addr, ip4_addr_get_u32(&gw_addr) | PP_HTONL(0x00000001UL)); + } + +#if LWIP_DHCP_AUTOIP_COOP + if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { + autoip_stop(netif); + dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; + } +#endif /* LWIP_DHCP_AUTOIP_COOP */ + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): IP: 0x%08"X32_F" SN: 0x%08"X32_F" GW: 0x%08"X32_F"\n", + ip4_addr_get_u32(&dhcp->offered_ip_addr), ip4_addr_get_u32(&sn_mask), ip4_addr_get_u32(&gw_addr))); + /* netif is now bound to DHCP leased address - set this before assigning the address + to ensure the callback can use dhcp_supplied_address() */ + dhcp_set_state(dhcp, DHCP_STATE_BOUND); + + netif_set_addr(netif, &dhcp->offered_ip_addr, &sn_mask, &gw_addr); + /* interface is used by routing now that an address is set */ +} + +/** + * @ingroup dhcp4 + * Renew an existing DHCP lease at the involved DHCP server. + * + * @param netif network interface which must renew its lease + */ +err_t +dhcp_renew(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + err_t result; + u16_t msecs; + u8_t i; + struct pbuf *p_out; + u16_t options_out_len; + + LWIP_ASSERT_CORE_LOCKED(); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_renew()\n")); + dhcp_set_state(dhcp, DHCP_STATE_RENEWING); + + /* create and initialize the DHCP message header */ + p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif)); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); + for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { + options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]); + } + +#if LWIP_NETIF_HOSTNAME + options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif); +#endif /* LWIP_NETIF_HOSTNAME */ + + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_RENEWING, msg_out, DHCP_REQUEST, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + result = udp_sendto_if(dhcp_pcb, p_out, &dhcp->server_ip_addr, LWIP_IANA_PORT_DHCP_SERVER, netif); + pbuf_free(p_out); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew: RENEWING\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_renew: could not allocate DHCP request\n")); + result = ERR_MEM; + } + if (dhcp->tries < 255) { + dhcp->tries++; + } + /* back-off on retries, but to a maximum of 20 seconds */ + msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000); + dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_renew(): set request timeout %"U16_F" msecs\n", msecs)); + return result; +} + +/** + * Rebind with a DHCP server for an existing DHCP lease. + * + * @param netif network interface which must rebind with a DHCP server + */ +static err_t +dhcp_rebind(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + err_t result; + u16_t msecs; + u8_t i; + struct pbuf *p_out; + u16_t options_out_len; + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n")); + dhcp_set_state(dhcp, DHCP_STATE_REBINDING); + + /* create and initialize the DHCP message header */ + p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif)); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); + for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { + options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]); + } + +#if LWIP_NETIF_HOSTNAME + options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif); +#endif /* LWIP_NETIF_HOSTNAME */ + + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_REBINDING, msg_out, DHCP_DISCOVER, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + /* broadcast to server */ + result = udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif); + pbuf_free(p_out); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_rebind: could not allocate DHCP request\n")); + result = ERR_MEM; + } + if (dhcp->tries < 255) { + dhcp->tries++; + } + msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000); + dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs)); + return result; +} + +/** + * Enter REBOOTING state to verify an existing lease + * + * @param netif network interface which must reboot + */ +static err_t +dhcp_reboot(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + err_t result; + u16_t msecs; + u8_t i; + struct pbuf *p_out; + u16_t options_out_len; + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n")); + dhcp_set_state(dhcp, DHCP_STATE_REBOOTING); + + /* create and initialize the DHCP message header */ + p_out = dhcp_create_msg(netif, dhcp, DHCP_REQUEST, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN_MIN_REQUIRED); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_REQUESTED_IP, 4); + options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); + + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options)); + for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) { + options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]); + } + +#if LWIP_NETIF_HOSTNAME + options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif); +#endif /* LWIP_NETIF_HOSTNAME */ + + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, DHCP_STATE_REBOOTING, msg_out, DHCP_REQUEST, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + /* broadcast to server */ + result = udp_sendto_if(dhcp_pcb, p_out, IP_ADDR_BROADCAST, LWIP_IANA_PORT_DHCP_SERVER, netif); + pbuf_free(p_out); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot: REBOOTING\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_reboot: could not allocate DHCP request\n")); + result = ERR_MEM; + } + if (dhcp->tries < 255) { + dhcp->tries++; + } + msecs = (u16_t)(dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000); + dhcp->request_timeout = (u16_t)((msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot(): set request timeout %"U16_F" msecs\n", msecs)); + return result; +} + +/** + * @ingroup dhcp4 + * Release a DHCP lease and stop DHCP statemachine (and AUTOIP if LWIP_DHCP_AUTOIP_COOP). + * + * @param netif network interface + */ +void +dhcp_release_and_stop(struct netif *netif) +{ + struct dhcp *dhcp = netif_dhcp_data(netif); + ip_addr_t server_ip_addr; + + LWIP_ASSERT_CORE_LOCKED(); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release_and_stop()\n")); + if (dhcp == NULL) { + return; + } + + /* already off? -> nothing to do */ + if (dhcp->state == DHCP_STATE_OFF) { + return; + } + + ip_addr_copy(server_ip_addr, dhcp->server_ip_addr); + + /* clean old DHCP offer */ + ip_addr_set_zero_ip4(&dhcp->server_ip_addr); + ip4_addr_set_zero(&dhcp->offered_ip_addr); + ip4_addr_set_zero(&dhcp->offered_sn_mask); + ip4_addr_set_zero(&dhcp->offered_gw_addr); +#if LWIP_DHCP_BOOTP_FILE + ip4_addr_set_zero(&dhcp->offered_si_addr); +#endif /* LWIP_DHCP_BOOTP_FILE */ + dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0; + dhcp->t1_renew_time = dhcp->t2_rebind_time = dhcp->lease_used = dhcp->t0_timeout = 0; + + /* send release message when current IP was assigned via DHCP */ + if (dhcp_supplied_address(netif)) { + /* create and initialize the DHCP message header */ + struct pbuf *p_out; + u16_t options_out_len; + p_out = dhcp_create_msg(netif, dhcp, DHCP_RELEASE, &options_out_len); + if (p_out != NULL) { + struct dhcp_msg *msg_out = (struct dhcp_msg *)p_out->payload; + options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_SERVER_ID, 4); + options_out_len = dhcp_option_long(options_out_len, msg_out->options, lwip_ntohl(ip4_addr_get_u32(ip_2_ip4(&server_ip_addr)))); + + LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, dhcp->state, msg_out, DHCP_RELEASE, &options_out_len); + dhcp_option_trailer(options_out_len, msg_out->options, p_out); + + udp_sendto_if(dhcp_pcb, p_out, &server_ip_addr, LWIP_IANA_PORT_DHCP_SERVER, netif); + pbuf_free(p_out); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_STATE_OFF\n")); + } else { + /* sending release failed, but that's not a problem since the correct behaviour of dhcp does not rely on release */ + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n")); + } + } + + /* remove IP address from interface (prevents routing from selecting this interface) */ + netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4); + +#if LWIP_DHCP_AUTOIP_COOP + if (dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) { + autoip_stop(netif); + dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF; + } +#endif /* LWIP_DHCP_AUTOIP_COOP */ + + dhcp_set_state(dhcp, DHCP_STATE_OFF); + + if (dhcp->pcb_allocated != 0) { + dhcp_dec_pcb_refcount(); /* free DHCP PCB if not needed any more */ + dhcp->pcb_allocated = 0; + } +} + +/** + * @ingroup dhcp4 + * This function calls dhcp_release_and_stop() internally. + * @deprecated Use dhcp_release_and_stop() instead. + */ +err_t +dhcp_release(struct netif *netif) +{ + dhcp_release_and_stop(netif); + return ERR_OK; +} + +/** + * @ingroup dhcp4 + * This function calls dhcp_release_and_stop() internally. + * @deprecated Use dhcp_release_and_stop() instead. + */ +void +dhcp_stop(struct netif *netif) +{ + dhcp_release_and_stop(netif); +} + +/* + * Set the DHCP state of a DHCP client. + * + * If the state changed, reset the number of tries. + */ +static void +dhcp_set_state(struct dhcp *dhcp, u8_t new_state) +{ + if (new_state != dhcp->state) { + dhcp->state = new_state; + dhcp->tries = 0; + dhcp->request_timeout = 0; + } +} + +/* + * Concatenate an option type and length field to the outgoing + * DHCP message. + * + */ +static u16_t +dhcp_option(u16_t options_out_len, u8_t *options, u8_t option_type, u8_t option_len) +{ + LWIP_ASSERT("dhcp_option: options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN); + options[options_out_len++] = option_type; + options[options_out_len++] = option_len; + return options_out_len; +} +/* + * Concatenate a single byte to the outgoing DHCP message. + * + */ +static u16_t +dhcp_option_byte(u16_t options_out_len, u8_t *options, u8_t value) +{ + LWIP_ASSERT("dhcp_option_byte: options_out_len < DHCP_OPTIONS_LEN", options_out_len < DHCP_OPTIONS_LEN); + options[options_out_len++] = value; + return options_out_len; +} + +static u16_t +dhcp_option_short(u16_t options_out_len, u8_t *options, u16_t value) +{ + LWIP_ASSERT("dhcp_option_short: options_out_len + 2 <= DHCP_OPTIONS_LEN", options_out_len + 2U <= DHCP_OPTIONS_LEN); + options[options_out_len++] = (u8_t)((value & 0xff00U) >> 8); + options[options_out_len++] = (u8_t) (value & 0x00ffU); + return options_out_len; +} + +static u16_t +dhcp_option_long(u16_t options_out_len, u8_t *options, u32_t value) +{ + LWIP_ASSERT("dhcp_option_long: options_out_len + 4 <= DHCP_OPTIONS_LEN", options_out_len + 4U <= DHCP_OPTIONS_LEN); + options[options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24); + options[options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16); + options[options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8); + options[options_out_len++] = (u8_t)((value & 0x000000ffUL)); + return options_out_len; +} + +#if LWIP_NETIF_HOSTNAME +static u16_t +dhcp_option_hostname(u16_t options_out_len, u8_t *options, struct netif *netif) +{ + if (netif->hostname != NULL) { + size_t namelen = strlen(netif->hostname); + if (namelen > 0) { + size_t len; + const char *p = netif->hostname; + /* Shrink len to available bytes (need 2 bytes for OPTION_HOSTNAME + and 1 byte for trailer) */ + size_t available = DHCP_OPTIONS_LEN - options_out_len - 3; + LWIP_ASSERT("DHCP: hostname is too long!", namelen <= available); + len = LWIP_MIN(namelen, available); + LWIP_ASSERT("DHCP: hostname is too long!", len <= 0xFF); + options_out_len = dhcp_option(options_out_len, options, DHCP_OPTION_HOSTNAME, (u8_t)len); + while (len--) { + options_out_len = dhcp_option_byte(options_out_len, options, *p++); + } + } + } + return options_out_len; +} +#endif /* LWIP_NETIF_HOSTNAME */ + +/** + * Extract the DHCP message and the DHCP options. + * + * Extract the DHCP message and the DHCP options, each into a contiguous + * piece of memory. As a DHCP message is variable sized by its options, + * and also allows overriding some fields for options, the easy approach + * is to first unfold the options into a contiguous piece of memory, and + * use that further on. + * + */ +static err_t +dhcp_parse_reply(struct pbuf *p, struct dhcp *dhcp) +{ + u8_t *options; + u16_t offset; + u16_t offset_max; + u16_t options_idx; + u16_t options_idx_max; + struct pbuf *q; + int parse_file_as_options = 0; + int parse_sname_as_options = 0; + struct dhcp_msg *msg_in; +#if LWIP_DHCP_BOOTP_FILE + int file_overloaded = 0; +#endif + + LWIP_UNUSED_ARG(dhcp); + + /* clear received options */ + dhcp_clear_all_options(dhcp); + /* check that beginning of dhcp_msg (up to and including chaddr) is in first pbuf */ + if (p->len < DHCP_SNAME_OFS) { + return ERR_BUF; + } + msg_in = (struct dhcp_msg *)p->payload; +#if LWIP_DHCP_BOOTP_FILE + /* clear boot file name */ + dhcp->boot_file_name[0] = 0; +#endif /* LWIP_DHCP_BOOTP_FILE */ + + /* parse options */ + + /* start with options field */ + options_idx = DHCP_OPTIONS_OFS; + /* parse options to the end of the received packet */ + options_idx_max = p->tot_len; +again: + q = p; + while ((q != NULL) && (options_idx >= q->len)) { + options_idx = (u16_t)(options_idx - q->len); + options_idx_max = (u16_t)(options_idx_max - q->len); + q = q->next; + } + if (q == NULL) { + return ERR_BUF; + } + offset = options_idx; + offset_max = options_idx_max; + options = (u8_t *)q->payload; + /* at least 1 byte to read and no end marker, then at least 3 bytes to read? */ + while ((q != NULL) && (offset < offset_max) && (options[offset] != DHCP_OPTION_END)) { + u8_t op = options[offset]; + u8_t len; + u8_t decode_len = 0; + int decode_idx = -1; + u16_t val_offset = (u16_t)(offset + 2); + if (val_offset < offset) { + /* overflow */ + return ERR_BUF; + } + /* len byte might be in the next pbuf */ + if ((offset + 1) < q->len) { + len = options[offset + 1]; + } else { + len = (q->next != NULL ? ((u8_t *)q->next->payload)[0] : 0); + } + /* LWIP_DEBUGF(DHCP_DEBUG, ("msg_offset=%"U16_F", q->len=%"U16_F, msg_offset, q->len)); */ + decode_len = len; + switch (op) { + /* case(DHCP_OPTION_END): handled above */ + case (DHCP_OPTION_PAD): + /* special option: no len encoded */ + decode_len = len = 0; + /* will be increased below */ + break; + case (DHCP_OPTION_SUBNET_MASK): + LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_SUBNET_MASK; + break; + case (DHCP_OPTION_ROUTER): + decode_len = 4; /* only copy the first given router */ + LWIP_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_ROUTER; + break; +#if LWIP_DHCP_PROVIDE_DNS_SERVERS + case (DHCP_OPTION_DNS_SERVER): + /* special case: there might be more than one server */ + LWIP_ERROR("len %% 4 == 0", len % 4 == 0, return ERR_VAL;); + /* limit number of DNS servers */ + decode_len = LWIP_MIN(len, 4 * DNS_MAX_SERVERS); + LWIP_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_DNS_SERVER; + break; +#endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ + case (DHCP_OPTION_LEASE_TIME): + LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_LEASE_TIME; + break; +#if LWIP_DHCP_GET_NTP_SRV + case (DHCP_OPTION_NTP): + /* special case: there might be more than one server */ + LWIP_ERROR("len %% 4 == 0", len % 4 == 0, return ERR_VAL;); + /* limit number of NTP servers */ + decode_len = LWIP_MIN(len, 4 * LWIP_DHCP_MAX_NTP_SERVERS); + LWIP_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_NTP_SERVER; + break; +#endif /* LWIP_DHCP_GET_NTP_SRV*/ + case (DHCP_OPTION_OVERLOAD): + LWIP_ERROR("len == 1", len == 1, return ERR_VAL;); + /* decode overload only in options, not in file/sname: invalid packet */ + LWIP_ERROR("overload in file/sname", options_idx == DHCP_OPTIONS_OFS, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_OVERLOAD; + break; + case (DHCP_OPTION_MESSAGE_TYPE): + LWIP_ERROR("len == 1", len == 1, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_MSG_TYPE; + break; + case (DHCP_OPTION_SERVER_ID): + LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_SERVER_ID; + break; + case (DHCP_OPTION_T1): + LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_T1; + break; + case (DHCP_OPTION_T2): + LWIP_ERROR("len == 4", len == 4, return ERR_VAL;); + decode_idx = DHCP_OPTION_IDX_T2; + break; + default: + decode_len = 0; + LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", (u16_t)op)); + LWIP_HOOK_DHCP_PARSE_OPTION(ip_current_netif(), dhcp, dhcp->state, msg_in, + dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) ? (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) : 0, + op, len, q, val_offset); + break; + } + if (op == DHCP_OPTION_PAD) { + offset++; + } else { + if (offset + len + 2 > 0xFFFF) { + /* overflow */ + return ERR_BUF; + } + offset = (u16_t)(offset + len + 2); + if (decode_len > 0) { + u32_t value = 0; + u16_t copy_len; +decode_next: + LWIP_ASSERT("check decode_idx", decode_idx >= 0 && decode_idx < DHCP_OPTION_IDX_MAX); + if (!dhcp_option_given(dhcp, decode_idx)) { + copy_len = LWIP_MIN(decode_len, 4); + if (pbuf_copy_partial(q, &value, copy_len, val_offset) != copy_len) { + return ERR_BUF; + } + if (decode_len > 4) { + /* decode more than one u32_t */ + u16_t next_val_offset; + LWIP_ERROR("decode_len %% 4 == 0", decode_len % 4 == 0, return ERR_VAL;); + dhcp_got_option(dhcp, decode_idx); + dhcp_set_option_value(dhcp, decode_idx, lwip_htonl(value)); + decode_len = (u8_t)(decode_len - 4); + next_val_offset = (u16_t)(val_offset + 4); + if (next_val_offset < val_offset) { + /* overflow */ + return ERR_BUF; + } + val_offset = next_val_offset; + decode_idx++; + goto decode_next; + } else if (decode_len == 4) { + value = lwip_ntohl(value); + } else { + LWIP_ERROR("invalid decode_len", decode_len == 1, return ERR_VAL;); + value = ((u8_t *)&value)[0]; + } + dhcp_got_option(dhcp, decode_idx); + dhcp_set_option_value(dhcp, decode_idx, value); + } + } + } + if (offset >= q->len) { + offset = (u16_t)(offset - q->len); + offset_max = (u16_t)(offset_max - q->len); + if (offset < offset_max) { + q = q->next; + LWIP_ERROR("next pbuf was null", q != NULL, return ERR_VAL;); + options = (u8_t *)q->payload; + } else { + /* We've run out of bytes, probably no end marker. Don't proceed. */ + return ERR_BUF; + } + } + } + /* is this an overloaded message? */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_OVERLOAD)) { + u32_t overload = dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_OVERLOAD); + dhcp_clear_option(dhcp, DHCP_OPTION_IDX_OVERLOAD); + if (overload == DHCP_OVERLOAD_FILE) { + parse_file_as_options = 1; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded file field\n")); + } else if (overload == DHCP_OVERLOAD_SNAME) { + parse_sname_as_options = 1; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname field\n")); + } else if (overload == DHCP_OVERLOAD_SNAME_FILE) { + parse_sname_as_options = 1; + parse_file_as_options = 1; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("overloaded sname and file field\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("invalid overload option: %d\n", (int)overload)); + } + } + if (parse_file_as_options) { + /* if both are overloaded, parse file first and then sname (RFC 2131 ch. 4.1) */ + parse_file_as_options = 0; + options_idx = DHCP_FILE_OFS; + options_idx_max = DHCP_FILE_OFS + DHCP_FILE_LEN; +#if LWIP_DHCP_BOOTP_FILE + file_overloaded = 1; +#endif + goto again; + } else if (parse_sname_as_options) { + parse_sname_as_options = 0; + options_idx = DHCP_SNAME_OFS; + options_idx_max = DHCP_SNAME_OFS + DHCP_SNAME_LEN; + goto again; + } +#if LWIP_DHCP_BOOTP_FILE + if (!file_overloaded) { + /* only do this for ACK messages */ + if (dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE) && + (dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE) == DHCP_ACK)) + /* copy bootp file name, don't care for sname (server hostname) */ + if (pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS) != (DHCP_FILE_LEN-1)) { + return ERR_BUF; + } + /* make sure the string is really NULL-terminated */ + dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0; + } +#endif /* LWIP_DHCP_BOOTP_FILE */ + return ERR_OK; +} + +/** + * If an incoming DHCP message is in response to us, then trigger the state machine + */ +static void +dhcp_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 dhcp *dhcp = netif_dhcp_data(netif); + struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload; + u8_t msg_type; + u8_t i; + struct dhcp_msg *msg_in; + + LWIP_UNUSED_ARG(arg); + + /* Caught DHCP message from netif that does not have DHCP enabled? -> not interested */ + if ((dhcp == NULL) || (dhcp->pcb_allocated == 0)) { + goto free_pbuf_and_return; + } + + LWIP_ASSERT("invalid server address type", IP_IS_V4(addr)); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_recv(pbuf = %p) from DHCP server %"U16_F".%"U16_F".%"U16_F".%"U16_F" port %"U16_F"\n", (void *)p, + ip4_addr1_16(ip_2_ip4(addr)), ip4_addr2_16(ip_2_ip4(addr)), ip4_addr3_16(ip_2_ip4(addr)), ip4_addr4_16(ip_2_ip4(addr)), port)); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len)); + LWIP_DEBUGF(DHCP_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 < DHCP_MIN_REPLY_LEN) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP reply message or pbuf too short\n")); + goto free_pbuf_and_return; + } + + if (reply_msg->op != DHCP_BOOTREPLY) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("not a DHCP reply message, but type %"U16_F"\n", (u16_t)reply_msg->op)); + goto free_pbuf_and_return; + } + /* iterate through hardware address and match against DHCP message */ + for (i = 0; i < netif->hwaddr_len && i < LWIP_MIN(DHCP_CHADDR_LEN, NETIF_MAX_HWADDR_LEN); i++) { + if (netif->hwaddr[i] != reply_msg->chaddr[i]) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, + ("netif->hwaddr[%"U16_F"]==%02"X16_F" != reply_msg->chaddr[%"U16_F"]==%02"X16_F"\n", + (u16_t)i, (u16_t)netif->hwaddr[i], (u16_t)i, (u16_t)reply_msg->chaddr[i])); + goto free_pbuf_and_return; + } + } + /* match transaction ID against what we expected */ + if (lwip_ntohl(reply_msg->xid) != dhcp->xid) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, + ("transaction id mismatch reply_msg->xid(%"X32_F")!=dhcp->xid(%"X32_F")\n", lwip_ntohl(reply_msg->xid), dhcp->xid)); + goto free_pbuf_and_return; + } + /* option fields could be unfold? */ + if (dhcp_parse_reply(p, dhcp) != ERR_OK) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, + ("problem unfolding DHCP message - too short on memory?\n")); + goto free_pbuf_and_return; + } + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("searching DHCP_OPTION_MESSAGE_TYPE\n")); + /* obtain pointer to DHCP message type */ + if (!dhcp_option_given(dhcp, DHCP_OPTION_IDX_MSG_TYPE)) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("DHCP_OPTION_MESSAGE_TYPE option not found\n")); + goto free_pbuf_and_return; + } + + msg_in = (struct dhcp_msg *)p->payload; + /* read DHCP message type */ + msg_type = (u8_t)dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_MSG_TYPE); + /* message type is DHCP ACK? */ + if (msg_type == DHCP_ACK) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_ACK received\n")); + /* in requesting state? */ + if (dhcp->state == DHCP_STATE_REQUESTING) { + dhcp_handle_ack(netif, msg_in); +#if DHCP_DOES_ARP_CHECK + if ((netif->flags & NETIF_FLAG_ETHARP) != 0) { + /* check if the acknowledged lease address is already in use */ + dhcp_check(netif); + } else { + /* bind interface to the acknowledged lease address */ + dhcp_bind(netif); + } +#else + /* bind interface to the acknowledged lease address */ + dhcp_bind(netif); +#endif + } + /* already bound to the given lease address? */ + else if ((dhcp->state == DHCP_STATE_REBOOTING) || (dhcp->state == DHCP_STATE_REBINDING) || + (dhcp->state == DHCP_STATE_RENEWING)) { + dhcp_handle_ack(netif, msg_in); + dhcp_bind(netif); + } + } + /* received a DHCP_NAK in appropriate state? */ + else if ((msg_type == DHCP_NAK) && + ((dhcp->state == DHCP_STATE_REBOOTING) || (dhcp->state == DHCP_STATE_REQUESTING) || + (dhcp->state == DHCP_STATE_REBINDING) || (dhcp->state == DHCP_STATE_RENEWING ))) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_NAK received\n")); + dhcp_handle_nak(netif); + } + /* received a DHCP_OFFER in DHCP_STATE_SELECTING state? */ + else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_STATE_SELECTING)) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_OFFER received in DHCP_STATE_SELECTING state\n")); + /* remember offered lease */ + dhcp_handle_offer(netif, msg_in); + } + +free_pbuf_and_return: + pbuf_free(p); +} + +/** + * Create a DHCP request, fill in common headers + * + * @param netif the netif under DHCP control + * @param dhcp dhcp control struct + * @param message_type message type of the request + */ +static struct pbuf * +dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type, u16_t *options_out_len) +{ + u16_t i; + struct pbuf *p_out; + struct dhcp_msg *msg_out; + u16_t options_out_len_loc; + +#ifndef DHCP_GLOBAL_XID + /** default global transaction identifier starting value (easy to match + * with a packet analyser). We simply increment for each new request. + * Predefine DHCP_GLOBAL_XID to a better value or a function call to generate one + * at runtime, any supporting function prototypes can be defined in DHCP_GLOBAL_XID_HEADER */ +#if DHCP_CREATE_RAND_XID && defined(LWIP_RAND) + static u32_t xid; +#else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ + static u32_t xid = 0xABCD0000; +#endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ +#else + if (!xid_initialised) { + xid = DHCP_GLOBAL_XID; + xid_initialised = !xid_initialised; + } +#endif + LWIP_ERROR("dhcp_create_msg: netif != NULL", (netif != NULL), return NULL;); + LWIP_ERROR("dhcp_create_msg: dhcp != NULL", (dhcp != NULL), return NULL;); + p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM); + if (p_out == NULL) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, + ("dhcp_create_msg(): could not allocate pbuf\n")); + return NULL; + } + LWIP_ASSERT("dhcp_create_msg: check that first pbuf can hold struct dhcp_msg", + (p_out->len >= sizeof(struct dhcp_msg))); + + /* DHCP_REQUEST should reuse 'xid' from DHCPOFFER */ + if ((message_type != DHCP_REQUEST) || (dhcp->state == DHCP_STATE_REBOOTING)) { + /* reuse transaction identifier in retransmissions */ + if (dhcp->tries == 0) { +#if DHCP_CREATE_RAND_XID && defined(LWIP_RAND) + xid = LWIP_RAND(); +#else /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ + xid++; +#endif /* DHCP_CREATE_RAND_XID && defined(LWIP_RAND) */ + } + dhcp->xid = xid; + } + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, + ("transaction id xid(%"X32_F")\n", xid)); + + msg_out = (struct dhcp_msg *)p_out->payload; + memset(msg_out, 0, sizeof(struct dhcp_msg)); + + msg_out->op = DHCP_BOOTREQUEST; + /* @todo: make link layer independent */ + msg_out->htype = LWIP_IANA_HWTYPE_ETHERNET; + msg_out->hlen = netif->hwaddr_len; + msg_out->xid = lwip_htonl(dhcp->xid); + /* we don't need the broadcast flag since we can receive unicast traffic + before being fully configured! */ + /* set ciaddr to netif->ip_addr based on message_type and state */ + if ((message_type == DHCP_INFORM) || (message_type == DHCP_DECLINE) || (message_type == DHCP_RELEASE) || + ((message_type == DHCP_REQUEST) && /* DHCP_STATE_BOUND not used for sending! */ + ((dhcp->state == DHCP_STATE_RENEWING) || dhcp->state == DHCP_STATE_REBINDING))) { + ip4_addr_copy(msg_out->ciaddr, *netif_ip4_addr(netif)); + } + for (i = 0; i < LWIP_MIN(DHCP_CHADDR_LEN, NETIF_MAX_HWADDR_LEN); i++) { + /* copy netif hardware address (padded with zeroes through memset already) */ + msg_out->chaddr[i] = netif->hwaddr[i]; + } + msg_out->cookie = PP_HTONL(DHCP_MAGIC_COOKIE); + /* Add option MESSAGE_TYPE */ + options_out_len_loc = dhcp_option(0, msg_out->options, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); + options_out_len_loc = dhcp_option_byte(options_out_len_loc, msg_out->options, message_type); + if (options_out_len) { + *options_out_len = options_out_len_loc; + } + return p_out; +} + +/** + * Add a DHCP message trailer + * + * Adds the END option to the DHCP message, and if + * necessary, up to three padding bytes. + */ +static void +dhcp_option_trailer(u16_t options_out_len, u8_t *options, struct pbuf *p_out) +{ + options[options_out_len++] = DHCP_OPTION_END; + /* packet is too small, or not 4 byte aligned? */ + while (((options_out_len < DHCP_MIN_OPTIONS_LEN) || (options_out_len & 3)) && + (options_out_len < DHCP_OPTIONS_LEN)) { + /* add a fill/padding byte */ + options[options_out_len++] = 0; + } + /* shrink the pbuf to the actual content length */ + pbuf_realloc(p_out, (u16_t)(sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + options_out_len)); +} + +/** check if DHCP supplied netif->ip_addr + * + * @param netif the netif to check + * @return 1 if DHCP supplied netif->ip_addr (states BOUND or RENEWING), + * 0 otherwise + */ +u8_t +dhcp_supplied_address(const struct netif *netif) +{ + if ((netif != NULL) && (netif_dhcp_data(netif) != NULL)) { + struct dhcp *dhcp = netif_dhcp_data(netif); + return (dhcp->state == DHCP_STATE_BOUND) || (dhcp->state == DHCP_STATE_RENEWING) || + (dhcp->state == DHCP_STATE_REBINDING); + } + return 0; +} + +#endif /* LWIP_IPV4 && LWIP_DHCP */ |