lwIP 2.1.2 Lightweight IP stack

Macros | Enumerations | Functions | Variables
dhcp.c File Reference
`#include "lwip/opt.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>`
`#include "path/to/my/lwip_hooks.h"`

## Macros
#define | DHCP_CREATE_RAND_XID 1
#define | DHCP_MAX_MSG_LEN(netif) (netif->mtu)
#define | DHCP_MIN_REPLY_LEN 44

## Enumerations
enum | dhcp_option_idx

## Functions
void | dhcp_coarse_tmr (void)
void | dhcp_fine_tmr (void)
void | dhcp_set_struct (struct netif *netif, struct dhcp *dhcp)
void | dhcp_cleanup (struct netif *netif)
err_t | dhcp_start (struct netif *netif)
void | dhcp_inform (struct netif *netif)
void | dhcp_network_changed (struct netif *netif)
void | dhcp_arp_reply (struct netif *netif, const ip4_addr_t *addr)
err_t | dhcp_renew (struct netif *netif)
void | dhcp_release_and_stop (struct netif *netif)
err_t | dhcp_release (struct netif *netif)
void | dhcp_stop (struct netif *netif)
u8_t | dhcp_supplied_address (const struct netif *netif)

## Variables
u32_t | dhcp_rx_options_val [DHCP_OPTION_IDX_MAX]
u8_t | dhcp_rx_options_given [DHCP_OPTION_IDX_MAX]

## Detailed Description

Dynamic Host Configuration Protocol client

## Macro Definition Documentation

## ◆ DHCP_CREATE_RAND_XID

#define DHCP_CREATE_RAND_XID 1

DHCP_CREATE_RAND_XID: if this is set to 1, the xid is created using LWIP_RAND() (this overrides DHCP_GLOBAL_XID)

## ◆ DHCP_MAX_MSG_LEN

#define DHCP_MAX_MSG_LEN | ( |  | netif | ) | (netif->mtu)

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() DHCP_OPTION_MAX_MSG_SIZE is set to the MTU MTU is checked to be big enough in dhcp_start

## ◆ DHCP_MIN_REPLY_LEN

#define DHCP_MIN_REPLY_LEN 44

Minimum length for reply before packet is parsed

## Enumeration Type Documentation

## ◆ dhcp_option_idx

enum dhcp_option_idx

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).

## Function Documentation

## ◆ dhcp_arp_reply()

void dhcp_arp_reply | ( | struct netif * | netif,
|  | const ip4_addr_t * | addr
| ) |  |

Match an ARP reply with the offered IP address: check whether the offered IP address is not in use using ARP

Parameters

  netif | the network interface on which the reply was received
  addr | The IP address we received a reply from

## ◆ dhcp_coarse_tmr()

void dhcp_coarse_tmr | ( | void |  | ) |

The DHCP timer that checks for lease renewal/rebind timeouts. Must be called once a minute (see DHCP_COARSE_TIMER_SECS).

## ◆ dhcp_fine_tmr()

void dhcp_fine_tmr | ( | void |  | ) |

DHCP transaction timeout handling (this function must be called every 500ms, see 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.

## ◆ dhcp_network_changed()

void dhcp_network_changed | ( | struct netif * | netif | ) |

Handle a possible change in the network configuration.

This enters the REBOOTING state to verify that the currently bound address is still valid.

## ◆ dhcp_supplied_address()

u8_t dhcp_supplied_address | ( | const struct netif * | netif | ) |

check if DHCP supplied netif->ip_addr

Parameters

  netif | the netif to check

Returns
  1 if DHCP supplied netif->ip_addr (states BOUND or RENEWING), 0 otherwise

## Variable Documentation

## ◆ dhcp_rx_options_given

u8_t dhcp_rx_options_given[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.

## ◆ dhcp_rx_options_val

u32_t dhcp_rx_options_val[DHCP_OPTION_IDX_MAX]

Holds the decoded option values, only valid while in dhcp_recv.