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Diffstat (limited to 'core/lwip/src/core/dhcp.c')
| -rw-r--r-- | core/lwip/src/core/dhcp.c | 1745 |
1 files changed, 1745 insertions, 0 deletions
diff --git a/core/lwip/src/core/dhcp.c b/core/lwip/src/core/dhcp.c new file mode 100644 index 00000000..81b4be27 --- /dev/null +++ b/core/lwip/src/core/dhcp.c @@ -0,0 +1,1745 @@ +/** + * @file + * Dynamic Host Configuration Protocol client + * + */ + +/* + * + * 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 a contribution to 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> + * + * 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, ...) + * + * Please coordinate changes and requests with Leon Woestenberg + * <leon.woestenberg@gmx.net> + * + * Integration with your code: + * + * In lwip/dhcp.h + * #define DHCP_COARSE_TIMER_SECS (recommended 60 which is a minute) + * #define DHCP_FINE_TIMER_MSECS (recommended 500 which equals TCP coarse timer) + * + * Then have your application call dhcp_coarse_tmr() and + * dhcp_fine_tmr() on the defined intervals. + * + * dhcp_start(struct netif *netif); + * starts a DHCP client instance which configures the interface by + * obtaining an IP address lease and maintaining it. + * + * Use dhcp_release(netif) to end the lease and use dhcp_stop(netif) + * to remove the DHCP client. + * + */ + +#include "lwip/opt.h" + +#if 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/sys.h" +#include "lwip/dhcp.h" +#include "lwip/autoip.h" +#include "lwip/dns.h" +#include "netif/etharp.h" + +#include <string.h> + +/** 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 + +/** 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). */ +#define DHCP_OPTION_IDX_OVERLOAD 0 +#define DHCP_OPTION_IDX_MSG_TYPE 1 +#define DHCP_OPTION_IDX_SERVER_ID 2 +#define DHCP_OPTION_IDX_LEASE_TIME 3 +#define DHCP_OPTION_IDX_T1 4 +#define DHCP_OPTION_IDX_T2 5 +#define DHCP_OPTION_IDX_SUBNET_MASK 6 +#define DHCP_OPTION_IDX_ROUTER 7 +#define DHCP_OPTION_IDX_DNS_SERVER 8 +#define DHCP_OPTION_IDX_MAX (DHCP_OPTION_IDX_DNS_SERVER + DNS_MAX_SERVERS) + +/** 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]; + +#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)) + + +/* 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, 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 err_t dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type); +/* free a DHCP request */ +static void dhcp_delete_msg(struct dhcp *dhcp); +/* add a DHCP option (type, then length in bytes) */ +static void dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len); +/* add option values */ +static void dhcp_option_byte(struct dhcp *dhcp, u8_t value); +static void dhcp_option_short(struct dhcp *dhcp, u16_t value); +static void dhcp_option_long(struct dhcp *dhcp, u32_t value); +/* always add the DHCP options trailer to end and pad */ +static void dhcp_option_trailer(struct dhcp *dhcp); + +/** + * 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; + 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)); + /* Set the interface down since the address must no longer be used, as per RFC2131 */ + netif_set_down(netif); + /* remove IP address from interface */ + netif_set_ipaddr(netif, IP_ADDR_ANY); + netif_set_gw(netif, IP_ADDR_ANY); + netif_set_netmask(netif, IP_ADDR_ANY); + /* Change to a defined state */ + dhcp_set_state(dhcp, DHCP_BACKING_OFF); + /* 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; + 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_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")); + } + dhcp->tries++; + msecs = 500; + dhcp->request_timeout = (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 *dhcp = netif->dhcp; + 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)) { + ip4_addr_set_u32(&dhcp->server_ip_addr, 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(&dhcp->server_ip_addr))); + /* remember offered address */ + ip_addr_copy(dhcp->offered_ip_addr, dhcp->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 = netif->dhcp; + err_t result; + u16_t msecs; + + 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_REQUESTING); + + /* create and initialize the DHCP message header */ + result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); + if (result == ERR_OK) { + dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); + + /* MUST request the offered IP address */ + dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); + dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); + + dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); + dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->server_ip_addr))); + + dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/); + dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK); + dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER); + dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST); + dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER); + +#if LWIP_NETIF_HOSTNAME + if (netif->hostname != NULL) { + const char *p = (const char*)netif->hostname; + u8_t namelen = (u8_t)strlen(p); + if (namelen > 0) { + LWIP_ASSERT("DHCP: hostname is too long!", namelen < 255); + dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, namelen); + while (*p) { + dhcp_option_byte(dhcp, *p++); + } + } + } +#endif /* LWIP_NETIF_HOSTNAME */ + + dhcp_option_trailer(dhcp); + /* shrink the pbuf to the actual content length */ + pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); + + /* send broadcast to any DHCP server */ + udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); + dhcp_delete_msg(dhcp); + 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")); + } + dhcp->tries++; + msecs = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000; + dhcp->request_timeout = (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. + */ +void +dhcp_coarse_tmr() +{ + struct netif *netif = netif_list; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n")); + /* iterate through all network interfaces */ + while (netif != NULL) { + /* only act on DHCP configured interfaces */ + if (netif->dhcp != NULL) { + /* timer is active (non zero), and triggers (zeroes) now? */ + if (netif->dhcp->t2_timeout-- == 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 (netif->dhcp->t1_timeout-- == 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); + } + } + /* proceed to next netif */ + netif = netif->next; + } +} + +/** + * DHCP transaction timeout handling + * + * 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() +{ + struct netif *netif = netif_list; + /* loop through netif's */ + while (netif != NULL) { + /* only act on DHCP configured interfaces */ + if (netif->dhcp != NULL) { + /* timer is active (non zero), and is about to trigger now */ + if (netif->dhcp->request_timeout > 1) { + netif->dhcp->request_timeout--; + } + else if (netif->dhcp->request_timeout == 1) { + netif->dhcp->request_timeout--; + /* { netif->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); + } + } + /* proceed to next network interface */ + netif = netif->next; + } +} + +/** + * 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; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_timeout()\n")); + /* back-off period has passed, or server selection timed out */ + if ((dhcp->state == DHCP_BACKING_OFF) || (dhcp->state == DHCP_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_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(netif); + dhcp_discover(netif); + } +#if DHCP_DOES_ARP_CHECK + /* received no ARP reply for the offered address (which is good) */ + } else if (dhcp->state == DHCP_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 */ + } + /* did not get response to renew request? */ + else if (dhcp->state == DHCP_RENEWING) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): RENEWING, DHCP request timed out\n")); + /* just retry renewal */ + /* note that the rebind timer will eventually time-out if renew does not work */ + dhcp_renew(netif); + /* did not get response to rebind request? */ + } else if (dhcp->state == DHCP_REBINDING) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): REBINDING, DHCP request timed out\n")); + if (dhcp->tries <= 8) { + dhcp_rebind(netif); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_timeout(): RELEASING, DISCOVERING\n")); + dhcp_release(netif); + dhcp_discover(netif); + } + } else if (dhcp->state == DHCP_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; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_t1_timeout()\n")); + if ((dhcp->state == DHCP_REQUESTING) || (dhcp->state == DHCP_BOUND) || + (dhcp->state == DHCP_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_RENEWING, not DHCP_BOUND */ + dhcp_renew(netif); + } +} + +/** + * 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; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_t2_timeout()\n")); + if ((dhcp->state == DHCP_REQUESTING) || (dhcp->state == DHCP_BOUND) || + (dhcp->state == DHCP_RENEWING)) { + /* 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_REBINDING, not DHCP_BOUND */ + dhcp_rebind(netif); + } +} + +/** + * Handle a DHCP ACK packet + * + * @param netif the netif under DHCP control + */ +static void +dhcp_handle_ack(struct netif *netif) +{ + struct dhcp *dhcp = netif->dhcp; +#if LWIP_DNS + u8_t n; +#endif /* LWIP_DNS */ + + /* clear options we might not get from the ACK */ + ip_addr_set_zero(&dhcp->offered_sn_mask); + ip_addr_set_zero(&dhcp->offered_gw_addr); +#if LWIP_DHCP_BOOTP_FILE + ip_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 */ + dhcp->offered_t2_rebind = dhcp->offered_t0_lease; + } + + /* (y)our internet address */ + ip_addr_copy(dhcp->offered_ip_addr, dhcp->msg_in->yiaddr); + +#if LWIP_DHCP_BOOTP_FILE + /* copy boot server address, + boot file name copied in dhcp_parse_reply if not overloaded */ + ip_addr_copy(dhcp->offered_si_addr, dhcp->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, 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, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_ROUTER))); + } + +#if LWIP_DNS + /* DNS servers */ + n = 0; + while(dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n) && (n < DNS_MAX_SERVERS)) { + ip_addr_t dns_addr; + ip4_addr_set_u32(&dns_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n))); + dns_setserver(n, &dns_addr); + n++; + } +#endif /* LWIP_DNS */ +} + +/** 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("netif != NULL", netif != NULL); + LWIP_ASSERT("dhcp != NULL", dhcp != NULL); + LWIP_ASSERT("netif already has a struct dhcp set", netif->dhcp == NULL); + + /* clear data structure */ + memset(dhcp, 0, sizeof(struct dhcp)); + /* dhcp_set_state(&dhcp, DHCP_OFF); */ + netif->dhcp = dhcp; +} + +/** 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("netif != NULL", netif != NULL); + + if (netif->dhcp != NULL) { + mem_free(netif->dhcp); + netif->dhcp = NULL; + } +} + +/** + * 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 = ERR_OK; + + LWIP_ERROR("netif != NULL", (netif != NULL), return ERR_ARG;); + dhcp = netif->dhcp; + 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)); + /* Remove the flag that says this netif is handled by DHCP, + it is set when we succeeded starting. */ + netif->flags &= ~NETIF_FLAG_DHCP; + + /* check hwtype of the netif */ + if ((netif->flags & NETIF_FLAG_ETHARP) == 0) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): No ETHARP netif\n")); + return ERR_ARG; + } + + /* 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(): starting 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->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 != NULL) { + udp_remove(dhcp->pcb); + } + LWIP_ASSERT("pbuf p_out wasn't freed", dhcp->p_out == NULL); + LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL ); + } + + /* clear data structure */ + memset(dhcp, 0, sizeof(struct dhcp)); + /* dhcp_set_state(&dhcp, DHCP_OFF); */ + /* allocate UDP PCB */ + dhcp->pcb = udp_new(); + if (dhcp->pcb == NULL) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): could not obtain pcb\n")); + return ERR_MEM; + } + dhcp->pcb->so_options |= SOF_BROADCAST; + /* set up local and remote port for the pcb */ + udp_bind(dhcp->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); + udp_connect(dhcp->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT); + /* set up the recv callback and argument */ + udp_recv(dhcp->pcb, dhcp_recv, netif); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_start(): starting DHCP configuration\n")); + /* (re)start the DHCP negotiation */ + result = dhcp_discover(netif); + if (result != ERR_OK) { + /* free resources allocated above */ + dhcp_stop(netif); + return ERR_MEM; + } + /* Set the flag that says this netif is handled by DHCP. */ + netif->flags |= NETIF_FLAG_DHCP; + return result; +} + +/** + * 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; + err_t result = ERR_OK; + struct udp_pcb *pcb; + + LWIP_ERROR("netif != NULL", (netif != NULL), return;); + + memset(&dhcp, 0, sizeof(struct dhcp)); + dhcp_set_state(&dhcp, DHCP_INFORM); + + if ((netif->dhcp != NULL) && (netif->dhcp->pcb != NULL)) { + /* re-use existing pcb */ + pcb = netif->dhcp->pcb; + } else { + pcb = udp_new(); + if (pcb == NULL) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform(): could not obtain pcb")); + return; + } + dhcp.pcb = pcb; + dhcp.pcb->so_options |= SOF_BROADCAST; + udp_bind(dhcp.pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_inform(): created new udp pcb\n")); + } + /* create and initialize the DHCP message header */ + result = dhcp_create_msg(netif, &dhcp, DHCP_INFORM); + if (result == ERR_OK) { + dhcp_option(&dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + dhcp_option_short(&dhcp, DHCP_MAX_MSG_LEN(netif)); + + dhcp_option_trailer(&dhcp); + + pbuf_realloc(dhcp.p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp.options_out_len); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_inform: INFORMING\n")); + udp_sendto_if(pcb, dhcp.p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); + dhcp_delete_msg(&dhcp); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_inform: could not allocate DHCP request\n")); + } + + if (dhcp.pcb != NULL) { + /* otherwise, the existing pcb was used */ + udp_remove(dhcp.pcb); + } +} + +/** 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; + if (!dhcp) + return; + switch (dhcp->state) { + case DHCP_REBINDING: + case DHCP_RENEWING: + case DHCP_BOUND: + case DHCP_REBOOTING: + netif_set_down(netif); + dhcp->tries = 0; + dhcp_reboot(netif); + break; + case DHCP_OFF: + /* stay off */ + break; + default: + dhcp->tries = 0; +#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_discover(netif); + break; + } +} + +#if DHCP_DOES_ARP_CHECK +/** + * Match an ARP reply with the offered IP address. + * + * @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, ip_addr_t *addr) +{ + LWIP_ERROR("netif != NULL", (netif != NULL), return;); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_arp_reply()\n")); + /* is a DHCP client doing an ARP check? */ + if ((netif->dhcp != NULL) && (netif->dhcp->state == DHCP_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 (ip_addr_cmp(addr, &netif->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; + err_t result = ERR_OK; + u16_t msecs; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_decline()\n")); + dhcp_set_state(dhcp, DHCP_BACKING_OFF); + /* create and initialize the DHCP message header */ + result = dhcp_create_msg(netif, dhcp, DHCP_DECLINE); + if (result == ERR_OK) { + dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); + dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); + + dhcp_option_trailer(dhcp); + /* resize pbuf to reflect true size of options */ + pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); + + /* per section 4.4.4, broadcast DECLINE messages */ + udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); + dhcp_delete_msg(dhcp); + 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")); + } + dhcp->tries++; + msecs = 10*1000; + dhcp->request_timeout = (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; + err_t result = ERR_OK; + u16_t msecs; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover()\n")); + ip_addr_set_any(&dhcp->offered_ip_addr); + dhcp_set_state(dhcp, DHCP_SELECTING); + /* create and initialize the DHCP message header */ + result = dhcp_create_msg(netif, dhcp, DHCP_DISCOVER); + if (result == ERR_OK) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: making request\n")); + + dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); + + dhcp_option(dhcp, DHCP_OPTION_PARAMETER_REQUEST_LIST, 4/*num options*/); + dhcp_option_byte(dhcp, DHCP_OPTION_SUBNET_MASK); + dhcp_option_byte(dhcp, DHCP_OPTION_ROUTER); + dhcp_option_byte(dhcp, DHCP_OPTION_BROADCAST); + dhcp_option_byte(dhcp, DHCP_OPTION_DNS_SERVER); + + dhcp_option_trailer(dhcp); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: realloc()ing\n")); + pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: sendto(DISCOVER, IP_ADDR_BROADCAST, DHCP_SERVER_PORT)\n")); + udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_discover: deleting()ing\n")); + dhcp_delete_msg(dhcp); + 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")); + } + 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 = (dhcp->tries < 6 ? 1 << dhcp->tries : 60) * 1000; + dhcp->request_timeout = (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; + ip_addr_t sn_mask, gw_addr; + LWIP_ERROR("dhcp_bind: netif != NULL", (netif != NULL), return;); + dhcp = netif->dhcp; + 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)); + + /* 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)); + } + /* 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)); + } + + if (dhcp->subnet_mask_given) { + /* copy offered network mask */ + ip_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)); + } + } + + ip_addr_copy(gw_addr, dhcp->offered_gw_addr); + /* gateway address not given? */ + if (ip_addr_isany(&gw_addr)) { + /* copy network address */ + ip_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"\n", + ip4_addr_get_u32(&dhcp->offered_ip_addr))); + netif_set_ipaddr(netif, &dhcp->offered_ip_addr); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): SN: 0x%08"X32_F"\n", + ip4_addr_get_u32(&sn_mask))); + netif_set_netmask(netif, &sn_mask); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_STATE, ("dhcp_bind(): GW: 0x%08"X32_F"\n", + ip4_addr_get_u32(&gw_addr))); + netif_set_gw(netif, &gw_addr); + /* bring the interface up */ + netif_set_up(netif); + /* netif is now bound to DHCP leased address */ + dhcp_set_state(dhcp, DHCP_BOUND); +} + +/** + * 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; + err_t result; + u16_t msecs; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_renew()\n")); + dhcp_set_state(dhcp, DHCP_RENEWING); + + /* create and initialize the DHCP message header */ + result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); + if (result == ERR_OK) { + dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); + +#if LWIP_NETIF_HOSTNAME + if (netif->hostname != NULL) { + const char *p = (const char*)netif->hostname; + u8_t namelen = (u8_t)strlen(p); + if (namelen > 0) { + LWIP_ASSERT("DHCP: hostname is too long!", namelen < 255); + dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, namelen); + while (*p) { + dhcp_option_byte(dhcp, *p++); + } + } + } +#endif /* LWIP_NETIF_HOSTNAME */ + +#if 0 + dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); + dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); +#endif + +#if 0 + dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); + dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr)); +#endif + /* append DHCP message trailer */ + dhcp_option_trailer(dhcp); + + pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); + + udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif); + dhcp_delete_msg(dhcp); + + 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")); + } + dhcp->tries++; + /* back-off on retries, but to a maximum of 20 seconds */ + msecs = dhcp->tries < 10 ? dhcp->tries * 2000 : 20 * 1000; + dhcp->request_timeout = (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; + err_t result; + u16_t msecs; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n")); + dhcp_set_state(dhcp, DHCP_REBINDING); + + /* create and initialize the DHCP message header */ + result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); + if (result == ERR_OK) { + dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif)); + +#if LWIP_NETIF_HOSTNAME + if (netif->hostname != NULL) { + const char *p = (const char*)netif->hostname; + u8_t namelen = (u8_t)strlen(p); + if (namelen > 0) { + LWIP_ASSERT("DHCP: hostname is too long!", namelen < 255); + dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, namelen); + while (*p) { + dhcp_option_byte(dhcp, *p++); + } + } + } +#endif /* LWIP_NETIF_HOSTNAME */ + +#if 0 + dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); + dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr)); + + dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4); + dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr)); +#endif + + dhcp_option_trailer(dhcp); + + pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); + + /* broadcast to server */ + udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); + dhcp_delete_msg(dhcp); + 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")); + } + dhcp->tries++; + msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; + dhcp->request_timeout = (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; + err_t result; + u16_t msecs; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n")); + dhcp_set_state(dhcp, DHCP_REBOOTING); + + /* create and initialize the DHCP message header */ + result = dhcp_create_msg(netif, dhcp, DHCP_REQUEST); + if (result == ERR_OK) { + dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN); + dhcp_option_short(dhcp, 576); + + dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4); + dhcp_option_long(dhcp, ntohl(ip4_addr_get_u32(&dhcp->offered_ip_addr))); + + dhcp_option_trailer(dhcp); + + pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); + + /* broadcast to server */ + udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif); + dhcp_delete_msg(dhcp); + 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")); + } + dhcp->tries++; + msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; + dhcp->request_timeout = (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; +} + + +/** + * Release a DHCP lease. + * + * @param netif network interface which must release its lease + */ +err_t +dhcp_release(struct netif *netif) +{ + struct dhcp *dhcp = netif->dhcp; + err_t result; + u16_t msecs; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release()\n")); + + /* idle DHCP client */ + dhcp_set_state(dhcp, DHCP_OFF); + /* clean old DHCP offer */ + ip_addr_set_zero(&dhcp->server_ip_addr); + ip_addr_set_zero(&dhcp->offered_ip_addr); + ip_addr_set_zero(&dhcp->offered_sn_mask); + ip_addr_set_zero(&dhcp->offered_gw_addr); +#if LWIP_DHCP_BOOTP_FILE + ip_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; + + /* create and initialize the DHCP message header */ + result = dhcp_create_msg(netif, dhcp, DHCP_RELEASE); + if (result == ERR_OK) { + dhcp_option_trailer(dhcp); + + pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len); + + udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif); + dhcp_delete_msg(dhcp); + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_OFF\n")); + } else { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n")); + } + dhcp->tries++; + msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000; + dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release(): set request timeout %"U16_F" msecs\n", msecs)); + /* bring the interface down */ + netif_set_down(netif); + /* remove IP address from interface */ + netif_set_ipaddr(netif, IP_ADDR_ANY); + netif_set_gw(netif, IP_ADDR_ANY); + netif_set_netmask(netif, IP_ADDR_ANY); + + return result; +} + +/** + * Remove the DHCP client from the interface. + * + * @param netif The network interface to stop DHCP on + */ +void +dhcp_stop(struct netif *netif) +{ + struct dhcp *dhcp; + LWIP_ERROR("dhcp_stop: netif != NULL", (netif != NULL), return;); + dhcp = netif->dhcp; + /* Remove the flag that says this netif is handled by DHCP. */ + netif->flags &= ~NETIF_FLAG_DHCP; + + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_stop()\n")); + /* netif is DHCP configured? */ + if (dhcp != NULL) { +#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 */ + + if (dhcp->pcb != NULL) { + udp_remove(dhcp->pcb); + dhcp->pcb = NULL; + } + LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL); + dhcp_set_state(dhcp, DHCP_OFF); + } +} + +/* + * 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 void +dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len) +{ + LWIP_ASSERT("dhcp_option: dhcp->options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN); + dhcp->msg_out->options[dhcp->options_out_len++] = option_type; + dhcp->msg_out->options[dhcp->options_out_len++] = option_len; +} +/* + * Concatenate a single byte to the outgoing DHCP message. + * + */ +static void +dhcp_option_byte(struct dhcp *dhcp, u8_t value) +{ + LWIP_ASSERT("dhcp_option_byte: dhcp->options_out_len < DHCP_OPTIONS_LEN", dhcp->options_out_len < DHCP_OPTIONS_LEN); + dhcp->msg_out->options[dhcp->options_out_len++] = value; +} + +static void +dhcp_option_short(struct dhcp *dhcp, u16_t value) +{ + LWIP_ASSERT("dhcp_option_short: dhcp->options_out_len + 2 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U <= DHCP_OPTIONS_LEN); + dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff00U) >> 8); + dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t) (value & 0x00ffU); +} + +static void +dhcp_option_long(struct dhcp *dhcp, u32_t value) +{ + LWIP_ASSERT("dhcp_option_long: dhcp->options_out_len + 4 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 4U <= DHCP_OPTIONS_LEN); + dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24); + dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16); + dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8); + dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x000000ffUL)); +} + +/** + * 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 conitguous piece of memory, and + * use that further on. + * + */ +static err_t +dhcp_parse_reply(struct dhcp *dhcp, struct pbuf *p) +{ + 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; + + /* 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; + } + dhcp->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 -= q->len; + 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) && (options[offset] != DHCP_OPTION_END) && (offset < offset_max)) { + u8_t op = options[offset]; + u8_t len; + u8_t decode_len = 0; + int decode_idx = -1; + u16_t val_offset = offset + 2; + /* 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 */ + offset--; + break; + case(DHCP_OPTION_SUBNET_MASK): + LWIP_ASSERT("len == 4", len == 4); + decode_idx = DHCP_OPTION_IDX_SUBNET_MASK; + break; + case(DHCP_OPTION_ROUTER): + decode_len = 4; /* only copy the first given router */ + LWIP_ASSERT("len >= decode_len", len >= decode_len); + decode_idx = DHCP_OPTION_IDX_ROUTER; + break; + case(DHCP_OPTION_DNS_SERVER): + /* special case: there might be more than one server */ + LWIP_ASSERT("len % 4 == 0", len % 4 == 0); + /* limit number of DNS servers */ + decode_len = LWIP_MIN(len, 4 * DNS_MAX_SERVERS); + LWIP_ASSERT("len >= decode_len", len >= decode_len); + decode_idx = DHCP_OPTION_IDX_DNS_SERVER; + break; + case(DHCP_OPTION_LEASE_TIME): + LWIP_ASSERT("len == 4", len == 4); + decode_idx = DHCP_OPTION_IDX_LEASE_TIME; + break; + case(DHCP_OPTION_OVERLOAD): + LWIP_ASSERT("len == 1", len == 1); + decode_idx = DHCP_OPTION_IDX_OVERLOAD; + break; + case(DHCP_OPTION_MESSAGE_TYPE): + LWIP_ASSERT("len == 1", len == 1); + decode_idx = DHCP_OPTION_IDX_MSG_TYPE; + break; + case(DHCP_OPTION_SERVER_ID): + LWIP_ASSERT("len == 4", len == 4); + decode_idx = DHCP_OPTION_IDX_SERVER_ID; + break; + case(DHCP_OPTION_T1): + LWIP_ASSERT("len == 4", len == 4); + decode_idx = DHCP_OPTION_IDX_T1; + break; + case(DHCP_OPTION_T2): + LWIP_ASSERT("len == 4", len == 4); + decode_idx = DHCP_OPTION_IDX_T2; + break; + default: + decode_len = 0; + LWIP_DEBUGF(DHCP_DEBUG, ("skipping option %"U16_F" in options\n", op)); + break; + } + 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); + LWIP_ASSERT("option already decoded", !dhcp_option_given(dhcp, decode_idx)); + copy_len = LWIP_MIN(decode_len, 4); + pbuf_copy_partial(q, &value, copy_len, val_offset); + if (decode_len > 4) { + /* decode more than one u32_t */ + LWIP_ASSERT("decode_len % 4 == 0", decode_len % 4 == 0); + dhcp_got_option(dhcp, decode_idx); + dhcp_set_option_value(dhcp, decode_idx, htonl(value)); + decode_len -= 4; + val_offset += 4; + decode_idx++; + goto decode_next; + } else if (decode_len == 4) { + value = ntohl(value); + } else { + LWIP_ASSERT("invalid decode_len", decode_len == 1); + value = ((u8_t*)&value)[0]; + } + dhcp_got_option(dhcp, decode_idx); + dhcp_set_option_value(dhcp, decode_idx, value); + } + if (offset >= q->len) { + offset -= q->len; + offset_max -= q->len; + q = q->next; + options = (u8_t*)q->payload; + } + } + /* 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 LWIP_DHCP_BOOTP_FILE + if (!parse_file_as_options) { + /* 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) */ + pbuf_copy_partial(p, dhcp->boot_file_name, DHCP_FILE_LEN-1, DHCP_FILE_OFS); + /* make sure the string is really NULL-terminated */ + dhcp->boot_file_name[DHCP_FILE_LEN-1] = 0; + } +#endif /* LWIP_DHCP_BOOTP_FILE */ + } + 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; + 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; + } + 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, ip_addr_t *addr, u16_t port) +{ + struct netif *netif = (struct netif *)arg; + struct dhcp *dhcp = netif->dhcp; + struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload; + u8_t msg_type; + u8_t i; + 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(addr), ip4_addr2_16(addr), ip4_addr3_16(addr), ip4_addr4_16(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); + + LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL); + + 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++) { + 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 (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",ntohl(reply_msg->xid),dhcp->xid)); + goto free_pbuf_and_return; + } + /* option fields could be unfold? */ + if (dhcp_parse_reply(dhcp, p) != 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; + } + + /* 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_REQUESTING) { + dhcp_handle_ack(netif); +#if DHCP_DOES_ARP_CHECK + /* check if the acknowledged lease address is already in use */ + dhcp_check(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_REBOOTING) || (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING)) { + dhcp_bind(netif); + } + } + /* received a DHCP_NAK in appropriate state? */ + else if ((msg_type == DHCP_NAK) && + ((dhcp->state == DHCP_REBOOTING) || (dhcp->state == DHCP_REQUESTING) || + (dhcp->state == DHCP_REBINDING) || (dhcp->state == DHCP_RENEWING ))) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_NAK received\n")); + dhcp_handle_nak(netif); + } + /* received a DHCP_OFFER in DHCP_SELECTING state? */ + else if ((msg_type == DHCP_OFFER) && (dhcp->state == DHCP_SELECTING)) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("DHCP_OFFER received in DHCP_SELECTING state\n")); + dhcp->request_timeout = 0; + /* remember offered lease */ + dhcp_handle_offer(netif); + } +free_pbuf_and_return: + dhcp->msg_in = NULL; + 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 err_t +dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type) +{ + u16_t i; +#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 */ + static u32_t xid = 0xABCD0000; +#else + static u32_t xid; + static u8_t xid_initialised = 0; + if (!xid_initialised) { + xid = DHCP_GLOBAL_XID; + xid_initialised = !xid_initialised; + } +#endif + LWIP_ERROR("dhcp_create_msg: netif != NULL", (netif != NULL), return ERR_ARG;); + LWIP_ERROR("dhcp_create_msg: dhcp != NULL", (dhcp != NULL), return ERR_VAL;); + LWIP_ASSERT("dhcp_create_msg: dhcp->p_out == NULL", dhcp->p_out == NULL); + LWIP_ASSERT("dhcp_create_msg: dhcp->msg_out == NULL", dhcp->msg_out == NULL); + dhcp->p_out = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct dhcp_msg), PBUF_RAM); + if (dhcp->p_out == NULL) { + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, + ("dhcp_create_msg(): could not allocate pbuf\n")); + return ERR_MEM; + } + LWIP_ASSERT("dhcp_create_msg: check that first pbuf can hold struct dhcp_msg", + (dhcp->p_out->len >= sizeof(struct dhcp_msg))); + + /* reuse transaction identifier in retransmissions */ + if (dhcp->tries == 0) { + xid++; + } + dhcp->xid = xid; + LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, + ("transaction id xid(%"X32_F")\n", xid)); + + dhcp->msg_out = (struct dhcp_msg *)dhcp->p_out->payload; + + dhcp->msg_out->op = DHCP_BOOTREQUEST; + /* TODO: make link layer independent */ + dhcp->msg_out->htype = DHCP_HTYPE_ETH; + dhcp->msg_out->hlen = netif->hwaddr_len; + dhcp->msg_out->hops = 0; + dhcp->msg_out->xid = htonl(dhcp->xid); + dhcp->msg_out->secs = 0; + /* we don't need the broadcast flag since we can receive unicast traffic + before being fully configured! */ + dhcp->msg_out->flags = 0; + ip_addr_set_zero(&dhcp->msg_out->ciaddr); + /* set ciaddr to netif->ip_addr based on message_type and state */ + if ((message_type == DHCP_INFORM) || (message_type == DHCP_DECLINE) || + ((message_type == DHCP_REQUEST) && /* DHCP_BOUND not used for sending! */ + ((dhcp->state==DHCP_RENEWING) || dhcp->state==DHCP_REBINDING))) { + ip_addr_copy(dhcp->msg_out->ciaddr, netif->ip_addr); + } + ip_addr_set_zero(&dhcp->msg_out->yiaddr); + ip_addr_set_zero(&dhcp->msg_out->siaddr); + ip_addr_set_zero(&dhcp->msg_out->giaddr); + for (i = 0; i < DHCP_CHADDR_LEN; i++) { + /* copy netif hardware address, pad with zeroes */ + dhcp->msg_out->chaddr[i] = (i < netif->hwaddr_len) ? netif->hwaddr[i] : 0/* pad byte*/; + } + for (i = 0; i < DHCP_SNAME_LEN; i++) { + dhcp->msg_out->sname[i] = 0; + } + for (i = 0; i < DHCP_FILE_LEN; i++) { + dhcp->msg_out->file[i] = 0; + } + dhcp->msg_out->cookie = PP_HTONL(DHCP_MAGIC_COOKIE); + dhcp->options_out_len = 0; + /* fill options field with an incrementing array (for debugging purposes) */ + for (i = 0; i < DHCP_OPTIONS_LEN; i++) { + dhcp->msg_out->options[i] = (u8_t)i; /* for debugging only, no matter if truncated */ + } + /* Add option MESSAGE_TYPE */ + dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN); + dhcp_option_byte(dhcp, message_type); + return ERR_OK; +} + +/** + * Free previously allocated memory used to send a DHCP request. + * + * @param dhcp the dhcp struct to free the request from + */ +static void +dhcp_delete_msg(struct dhcp *dhcp) +{ + LWIP_ERROR("dhcp_delete_msg: dhcp != NULL", (dhcp != NULL), return;); + LWIP_ASSERT("dhcp_delete_msg: dhcp->p_out != NULL", dhcp->p_out != NULL); + LWIP_ASSERT("dhcp_delete_msg: dhcp->msg_out != NULL", dhcp->msg_out != NULL); + if (dhcp->p_out != NULL) { + pbuf_free(dhcp->p_out); + } + dhcp->p_out = NULL; + dhcp->msg_out = NULL; +} + +/** + * Add a DHCP message trailer + * + * Adds the END option to the DHCP message, and if + * necessary, up to three padding bytes. + * + * @param dhcp DHCP state structure + */ +static void +dhcp_option_trailer(struct dhcp *dhcp) +{ + LWIP_ERROR("dhcp_option_trailer: dhcp != NULL", (dhcp != NULL), return;); + LWIP_ASSERT("dhcp_option_trailer: dhcp->msg_out != NULL\n", dhcp->msg_out != NULL); + LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN); + dhcp->msg_out->options[dhcp->options_out_len++] = DHCP_OPTION_END; + /* packet is too small, or not 4 byte aligned? */ + while ((dhcp->options_out_len < DHCP_MIN_OPTIONS_LEN) || (dhcp->options_out_len & 3)) { + /* LWIP_DEBUGF(DHCP_DEBUG,("dhcp_option_trailer:dhcp->options_out_len=%"U16_F", DHCP_OPTIONS_LEN=%"U16_F, dhcp->options_out_len, DHCP_OPTIONS_LEN)); */ + LWIP_ASSERT("dhcp_option_trailer: dhcp->options_out_len < DHCP_OPTIONS_LEN\n", dhcp->options_out_len < DHCP_OPTIONS_LEN); + /* add a fill/padding byte */ + dhcp->msg_out->options[dhcp->options_out_len++] = 0; + } +} + +#endif /* LWIP_DHCP */ |