dhcp.c

freescale k40/k60 freertos-lwip例程

{
  struct dhcp *dhcp = netif->dhcp;
  err_t result;
  u16_t msecs;
#if LWIP_NETIF_HOSTNAME
  const char *p;
#endif /* LWIP_NETIF_HOSTNAME */
  LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind()\n"));
  dhcp_set_state(dhcp, DHCP_REBINDING);

  /* create and initialize the DHCP message header */
  result = dhcp_create_request(netif);
  if (result == ERR_OK) {

    dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
    dhcp_option_byte(dhcp, DHCP_REQUEST);

    dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
    dhcp_option_short(dhcp, DHCP_MAX_MSG_LEN(netif));

#if LWIP_NETIF_HOSTNAME
    p = (const char*)netif->hostname;
    if (p != NULL) {
      dhcp_option(dhcp, DHCP_OPTION_HOSTNAME, strlen(p));
      while (*p) {
        dhcp_option_byte(dhcp, *p++);
      }
    }
#endif /* LWIP_NETIF_HOSTNAME */

#if 0
    dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
    dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr));

    dhcp_option(dhcp, DHCP_OPTION_SERVER_ID, 4);
    dhcp_option_long(dhcp, ntohl(dhcp->server_ip_addr.addr));
#endif

    dhcp_option_trailer(dhcp);

    pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);

    /* broadcast to server */
    udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
    dhcp_delete_request(netif);
    LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind: REBINDING\n"));
  } else {
    LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_rebind: could not allocate DHCP request\n"));
  }
  dhcp->tries++;
  msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000;
  dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
  LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_rebind(): set request timeout %"U16_F" msecs\n", msecs));
  return result;
}

/**
 * Enter REBOOTING state to verify an existing lease
 *
 * @param netif network interface which must reboot
 */
static err_t
dhcp_reboot(struct netif *netif)
{
  struct dhcp *dhcp = netif->dhcp;
  err_t result;
  u16_t msecs;
  LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot()\n"));
  dhcp_set_state(dhcp, DHCP_REBOOTING);

  /* create and initialize the DHCP message header */
  result = dhcp_create_request(netif);
  if (result == ERR_OK) {

    dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
    dhcp_option_byte(dhcp, DHCP_REQUEST);

    dhcp_option(dhcp, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
    dhcp_option_short(dhcp, 576);

    dhcp_option(dhcp, DHCP_OPTION_REQUESTED_IP, 4);
    dhcp_option_long(dhcp, ntohl(dhcp->offered_ip_addr.addr));

    dhcp_option_trailer(dhcp);

    pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);

    /* broadcast to server */
    udp_sendto_if(dhcp->pcb, dhcp->p_out, IP_ADDR_BROADCAST, DHCP_SERVER_PORT, netif);
    dhcp_delete_request(netif);
    LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot: REBOOTING\n"));
  } else {
    LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_reboot: could not allocate DHCP request\n"));
  }
  dhcp->tries++;
  msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000;
  dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
  LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_reboot(): set request timeout %"U16_F" msecs\n", msecs));
  return result;
}


/**
 * Release a DHCP lease.
 *
 * @param netif network interface which must release its lease
 */
err_t
dhcp_release(struct netif *netif)
{
  struct dhcp *dhcp = netif->dhcp;
  err_t result;
  u16_t msecs;
  LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_release()\n"));

  /* idle DHCP client */
  dhcp_set_state(dhcp, DHCP_OFF);
  /* clean old DHCP offer */
  dhcp->server_ip_addr.addr = 0;
  dhcp->offered_ip_addr.addr = dhcp->offered_sn_mask.addr = 0;
  dhcp->offered_gw_addr.addr = dhcp->offered_bc_addr.addr = 0;
  dhcp->offered_t0_lease = dhcp->offered_t1_renew = dhcp->offered_t2_rebind = 0;
  dhcp->dns_count = 0;
  
  /* create and initialize the DHCP message header */
  result = dhcp_create_request(netif);
  if (result == ERR_OK) {
    dhcp_option(dhcp, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
    dhcp_option_byte(dhcp, DHCP_RELEASE);

    dhcp_option_trailer(dhcp);

    pbuf_realloc(dhcp->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + dhcp->options_out_len);

    udp_sendto_if(dhcp->pcb, dhcp->p_out, &dhcp->server_ip_addr, DHCP_SERVER_PORT, netif);
    dhcp_delete_request(netif);
    LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release: RELEASED, DHCP_OFF\n"));
  } else {
    LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("dhcp_release: could not allocate DHCP request\n"));
  }
  dhcp->tries++;
  msecs = dhcp->tries < 10 ? dhcp->tries * 1000 : 10 * 1000;
  dhcp->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
  LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("dhcp_release(): set request timeout %"U16_F" msecs\n", msecs));
  /* bring the interface down */
  netif_set_down(netif);
  /* remove IP address from interface */
  netif_set_ipaddr(netif, IP_ADDR_ANY);
  netif_set_gw(netif, IP_ADDR_ANY);
  netif_set_netmask(netif, IP_ADDR_ANY);
  
  /* TODO: netif_down(netif); */
  return result;
}

/**
 * Remove the DHCP client from the interface.
 *
 * @param netif The network interface to stop DHCP on
 */
void
dhcp_stop(struct netif *netif)
{
  struct dhcp *dhcp = netif->dhcp;
  LWIP_ERROR("dhcp_stop: netif != NULL", (netif != NULL), return;);
  /* Remove the flag that says this netif is handled by DHCP. */
  netif->flags &= ~NETIF_FLAG_DHCP;

  LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_stop()\n"));
  /* netif is DHCP configured? */
  if (dhcp != NULL) {
#if LWIP_DHCP_AUTOIP_COOP
  if(dhcp->autoip_coop_state == DHCP_AUTOIP_COOP_STATE_ON) {
    autoip_stop(netif);
    dhcp->autoip_coop_state = DHCP_AUTOIP_COOP_STATE_OFF;
  }
#endif /* LWIP_DHCP_AUTOIP_COOP */

    if (dhcp->pcb != NULL) {
      udp_remove(dhcp->pcb);
      dhcp->pcb = NULL;
    }
    LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL &&
      dhcp->options_in == NULL && dhcp->options_in_len == 0);
    mem_free((void *)dhcp);
    netif->dhcp = NULL;
  }
}

/*
 * Set the DHCP state of a DHCP client.
 *
 * If the state changed, reset the number of tries.
 *
 * TODO: we might also want to reset the timeout here?
 */
static void
dhcp_set_state(struct dhcp *dhcp, u8_t new_state)
{
  if (new_state != dhcp->state) {
    dhcp->state = new_state;
    dhcp->tries = 0;
  }
}

/*
 * Concatenate an option type and length field to the outgoing
 * DHCP message.
 *
 */
static void
dhcp_option(struct dhcp *dhcp, u8_t option_type, u8_t option_len)
{
  LWIP_ASSERT("dhcp_option: dhcp->options_out_len + 2 + option_len <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U + option_len <= DHCP_OPTIONS_LEN);
  dhcp->msg_out->options[dhcp->options_out_len++] = option_type;
  dhcp->msg_out->options[dhcp->options_out_len++] = option_len;
}
/*
 * Concatenate a single byte to the outgoing DHCP message.
 *
 */
static void
dhcp_option_byte(struct dhcp *dhcp, u8_t value)
{
  LWIP_ASSERT("dhcp_option_byte: dhcp->options_out_len < DHCP_OPTIONS_LEN", dhcp->options_out_len < DHCP_OPTIONS_LEN);
  dhcp->msg_out->options[dhcp->options_out_len++] = value;
}

static void
dhcp_option_short(struct dhcp *dhcp, u16_t value)
{
  LWIP_ASSERT("dhcp_option_short: dhcp->options_out_len + 2 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 2U <= DHCP_OPTIONS_LEN);
  dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff00U) >> 8);
  dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t) (value & 0x00ffU);
}

static void
dhcp_option_long(struct dhcp *dhcp, u32_t value)
{
  LWIP_ASSERT("dhcp_option_long: dhcp->options_out_len + 4 <= DHCP_OPTIONS_LEN", dhcp->options_out_len + 4U <= DHCP_OPTIONS_LEN);
  dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0xff000000UL) >> 24);
  dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x00ff0000UL) >> 16);
  dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x0000ff00UL) >> 8);
  dhcp->msg_out->options[dhcp->options_out_len++] = (u8_t)((value & 0x000000ffUL));
}

/**
 * Extract the DHCP message and the DHCP options.
 *
 * Extract the DHCP message and the DHCP options, each into a contiguous
 * piece of memory. As a DHCP message is variable sized by its options,
 * and also allows overriding some fields for options, the easy approach
 * is to first unfold the options into a conitguous piece of memory, and
 * use that further on.
 *
 */
static err_t
dhcp_unfold_reply(struct dhcp *dhcp, struct pbuf *p)
{
  u16_t ret;
  LWIP_ERROR("dhcp != NULL", (dhcp != NULL), return ERR_ARG;);
  /* free any left-overs from previous unfolds */
  dhcp_free_reply(dhcp);
  /* options present? */
  if (p->tot_len > (sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN)) {
    dhcp->options_in_len = p->tot_len - (sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN);
    dhcp->options_in = mem_malloc(dhcp->options_in_len);
    if (dhcp->options_in == NULL) {
      LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
        ("dhcp_unfold_reply(): could not allocate dhcp->options\n"));
      dhcp->options_in_len = 0;
      return ERR_MEM;
    }
  }
  dhcp->msg_in = mem_malloc(sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN);
  if (dhcp->msg_in == NULL) {
    LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
      ("dhcp_unfold_reply(): could not allocate dhcp->msg_in\n"));
    if (dhcp->options_in != NULL) {
      mem_free(dhcp->options_in);
      dhcp->options_in = NULL;
      dhcp->options_in_len = 0;
    }
    return ERR_MEM;
  }

  /** copy the DHCP message without options */
  ret = pbuf_copy_partial(p, dhcp->msg_in, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN, 0);
  LWIP_ASSERT("ret == sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN", ret == sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN);
  LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_unfold_reply(): copied %"U16_F" bytes into dhcp->msg_in[]\n",
     sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN));

  if (dhcp->options_in != NULL) {
    /** copy the DHCP options */
    ret = pbuf_copy_partial(p, dhcp->options_in, dhcp->options_in_len, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN);
    LWIP_ASSERT("ret == dhcp->options_in_len", ret == dhcp->options_in_len);
    LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_unfold_reply(): copied %"U16_F" bytes to dhcp->options_in[]\n",
      dhcp->options_in_len));
  }
  LWIP_UNUSED_ARG(ret);
  return ERR_OK;
}

/**
 * Free the incoming DHCP message including contiguous copy of
 * its DHCP options.
 */
static void dhcp_free_reply(struct dhcp *dhcp)
{
  if (dhcp->msg_in != NULL) {
    mem_free((void *)dhcp->msg_in);
    dhcp->msg_in = NULL;
  }
  if (dhcp->options_in) {
    mem_free(dhcp->options_in);
    dhcp->options_in = NULL;
    dhcp->options_in_len = 0;
  }
  LWIP_DEBUGF(DHCP_DEBUG, ("dhcp_free_reply(): free'd\n"));
}

/**
 * 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, struct ip_addr *addr, u16_t port)
{
  struct netif *netif = (struct netif *)arg;
  struct dhcp *dhcp = netif->dhcp;
  struct dhcp_msg *reply_msg = (struct dhcp_msg *)p->payload;
  u8_t *options_ptr;
  u8_t msg_type;
  u8_t i;
  LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_recv(pbuf = %p) from DHCP server %"U16_F".%"U16_F".%"U16_F".%"U16_F" port %"U16_F"\n", (void*)p,
    (u16_t)(ntohl(addr->addr) >> 24 & 0xff), (u16_t)(ntohl(addr->addr) >> 16 & 0xff),
    (u16_t)(ntohl(addr->addr) >>  8 & 0xff), (u16_t)(ntohl(addr->addr) & 0xff), port));
  LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->len = %"U16_F"\n", p->len));
  LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("pbuf->tot_len = %"U16_F"\n", p->tot_len));
  /* prevent warnings about unused arguments */
  LWIP_UNUSED_ARG(pcb);
  LWIP_UNUSED_ARG(addr);
  LWIP_UNUSED_ARG(port);

  LWIP_ASSERT("reply wasn't freed", dhcp->msg_in == NULL &&
    dhcp->options_in == NULL && dhcp->options_in_len == 0);