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lwip/src/core/ipv4/dhcp.c
Jasper Verschueren d65681a7d7 DHCP request send on reboot does not contain hostname option 
When the network is changed, dhcp is rebooted.
It will send a dhcp request again to verify it's lease.

DHCP requests are send out in selecting state, rebinding, renewing
and rebooting. But in the rebooting state the hostname option is
not included. This means that after reboot, the hostname will be
unknown to the DNS.

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>
2018-07-11 19:55:49 +02:00

1994 lines
74 KiB
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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 LWIP_DHCP_CHECK_LINK_UP
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;
}
#endif /* LWIP_DHCP_CHECK_LINK_UP */
/* (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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