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