/** * @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 * 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 * */ #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/acd.h" #include "lwip/dns.h" #include "lwip/etharp.h" #include "lwip/prot/dhcp.h" #include "lwip/prot/iana.h" #include #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 #ifndef LWIP_DHCP_INPUT_ERROR #define LWIP_DHCP_INPUT_ERROR(message, expression, handler) do { if (!(expression)) { \ handler;} } while(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]; #if LWIP_DHCP_PROVIDE_DNS_SERVERS /** Determines whether the DNS server will be overwritten by DHCP */ static u8_t dhcp_dns_overwrite = 1; #endif 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 LWIP_DHCP_DOES_ACD_CHECK static err_t dhcp_decline(struct netif *netif); #endif /* LWIP_DHCP_DOES_ACD_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 LWIP_DHCP_DOES_ACD_CHECK /** * Handle conflict information from ACD module * * @param netif network interface to handle conflict information on * @param state acd_callback_enum_t */ static void dhcp_conflict_callback(struct netif *netif, acd_callback_enum_t state) { struct dhcp *dhcp = netif_dhcp_data(netif); u16_t msecs; switch (state) { case ACD_IP_OK: dhcp_bind(netif); break; case ACD_RESTART_CLIENT: /* wait 10s before restarting * According to RFC2131 section 3.1 point 5: * If the client detects that the address is already in use (e.g., through * the use of ARP), the client MUST send a DHCPDECLINE message to the * server and restarts the configuration process. The client SHOULD wait * a minimum of ten seconds before restarting the configuration process to * avoid excessive network traffic in case of looping. */ dhcp_set_state(dhcp, DHCP_STATE_BACKING_OFF); 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)); break; case ACD_DECLINE: /* remove IP address from interface * (prevents routing from selecting this interface) */ netif_set_addr(netif, IP4_ADDR_ANY4, IP4_ADDR_ANY4, IP4_ADDR_ANY4); /* Let the DHCP server know we will not use the address */ dhcp_decline(netif); break; default: break; } } /** * Checks if the offered IP address is already in use. * * It does this according to the address conflict detection method described in * RFC5227. * * @param netif the netif under DHCP control */ static void dhcp_check(struct netif *netif) { struct dhcp *dhcp = netif_dhcp_data(netif); 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); /* start ACD module */ acd_start(netif, &dhcp->acd, dhcp->offered_ip_addr); } #endif /* LWIP_DHCP_DOES_ACD_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); } } 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->flags |= DHCP_FLAG_SUBNET_MASK_GIVEN; } else { dhcp->flags &= ~DHCP_FLAG_SUBNET_MASK_GIVEN; } /* 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 */ if (dhcp_dns_overwrite) { 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)); /* mark this as externally allocated */ dhcp->flags |= DHCP_FLAG_EXTERNAL_MEM; /* 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) { struct dhcp *dhcp; LWIP_ASSERT_CORE_LOCKED(); LWIP_ASSERT("netif != NULL", netif != NULL); dhcp = netif_dhcp_data(netif); if (dhcp != NULL) { if (!(dhcp->flags & DHCP_FLAG_EXTERNAL_MEM)) { mem_free(dhcp); } 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); */ #if LWIP_DHCP_DOES_ACD_CHECK /* add acd struct to list*/ acd_add(netif, &dhcp->acd, dhcp_conflict_callback); #endif /* LWIP_DHCP_DOES_ACD_CHECK */ 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_link_up(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 */ /* ensure we start with short timeouts, even if already discovering */ dhcp->tries = 0; dhcp_discover(netif); break; } } #if LWIP_DHCP_DOES_ACD_CHECK /** * 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; 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; } return result; } #endif /* LWIP_DHCP_DOES_ACD_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")); #if LWIP_DHCP_AUTOIP_COOP if (dhcp->tries >= LWIP_DHCP_AUTOIP_COOP_TRIES) { autoip_start(netif); } #endif /* LWIP_DHCP_AUTOIP_COOP */ 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()\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++; } 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->flags & DHCP_FLAG_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)); } 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; dhcp_set_state(dhcp, DHCP_STATE_OFF); 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); } else { 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_offset; 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; options_offset = options_idx; 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_DHCP_INPUT_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_DHCP_INPUT_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_DHCP_INPUT_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_DHCP_INPUT_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_DHCP_INPUT_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_DHCP_INPUT_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_DHCP_INPUT_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_DHCP_INPUT_ERROR("len == 1", len == 1, return ERR_VAL;); /* decode overload only in options, not in file/sname: invalid packet */ LWIP_DHCP_INPUT_ERROR("overload in file/sname", options_offset == DHCP_OPTIONS_OFS, return ERR_VAL;); decode_idx = DHCP_OPTION_IDX_OVERLOAD; break; case (DHCP_OPTION_MESSAGE_TYPE): LWIP_DHCP_INPUT_ERROR("len == 1", len == 1, return ERR_VAL;); decode_idx = DHCP_OPTION_IDX_MSG_TYPE; break; case (DHCP_OPTION_SERVER_ID): LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;); decode_idx = DHCP_OPTION_IDX_SERVER_ID; break; case (DHCP_OPTION_T1): LWIP_DHCP_INPUT_ERROR("len == 4", len == 4, return ERR_VAL;); decode_idx = DHCP_OPTION_IDX_T1; break; case (DHCP_OPTION_T2): LWIP_DHCP_INPUT_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_DHCP_INPUT_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_DHCP_INPUT_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_DHCP_INPUT_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 or just reconnected to the network? */ if ((dhcp->state == DHCP_STATE_REQUESTING) || (dhcp->state == DHCP_STATE_REBOOTING)) { dhcp_handle_ack(netif, msg_in); #if LWIP_DHCP_DOES_ACD_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 and using it? */ else if ((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; } #if LWIP_DHCP_PROVIDE_DNS_SERVERS /** Choose whether or not DHCP will overwrite the DNS server * * @param set 0 if DHCP will not overwrite DNS * other if DHCP will overwrite DNS */ void dhcp_set_dns_overwrite_setting(u8_t set) { dhcp_dns_overwrite = set ? 1 : 0; } /** Get the DHCP DNS overwrite setting * * @return 1 if DHCP will overwrite DNS * 0 if HDCP will not overwrite DNS */ u8_t dhcp_get_dns_overwrite_setting() { return dhcp_dns_overwrite; } #endif /* LWIP_DHCP_PROVIDE_DNS_SERVERS */ #endif /* LWIP_IPV4 && LWIP_DHCP */