dhcp_cbfunc

#include <net_config.h>

void dhcp_cbfunc (
     U8  opt,     /* DHCP Option code.  */
     U8* val,     /* DHCP Option value. */
     U16 len);    /* DHCP Option length.*/

The dhcp_cbfunc function is what DHCP client calls, when the extended DHCP options are enabled in system configuration. This function is used to notify the user about extended DHCP option values. If this function is not provided in the user code, the DHCP client notifications are not possible.

The argument opt specifies the extended DHCP option code. The argument *val is a pointer to the option value. The option value length is len bytes.

The type of the option value is defined by the opt parameter. Currently supported extended DHCP options are shown in the table.

The dhcp_cbfunc function is part of RL-TCPnet. The prototype is defined in net_config.h.

Note

• This function is optional. If is not needed for default DHCP client configuration.

dhcp_disable

#include <net_config.h>

char boot_file[64];
U8 ntp_server[4];

void dhcp_cbfunc (U8 opt, U8 *val, U16 len) {
  /* DHCP client notification callback function */

  switch (opt) {
    case 42:
      /* DHCP Server has returned NTP Server list in DHCP response. */
      memcpy (ntp_server, val, 4);
      break;

    case 67:
      /* DHCP Server has returned Bootfile Name in DHCP response. */
      strcpy (boot_file, (char *)val);
      break;
  }
}