contrib/dhcpcd/src/arp.h

   1 /* SPDX-License-Identifier: BSD-2-Clause */
   2 /*
   3  * dhcpcd - DHCP client daemon
   4  * Copyright (c) 2006-2019 Roy Marples <roy@marples.name>
   5  * All rights reserved
   6
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #ifndef ARP_H
  30 #define ARP_H
  31
  32 /* ARP timings from RFC5227 */
  33 #define PROBE_WAIT               1
  34 #define PROBE_NUM                3
  35 #define PROBE_MIN                1
  36 #define PROBE_MAX                2
  37 #define ANNOUNCE_WAIT            2
  38 #define ANNOUNCE_NUM             2
  39 #define ANNOUNCE_INTERVAL        2
  40 #define MAX_CONFLICTS           10
  41 #define RATE_LIMIT_INTERVAL     60
  42 #define DEFEND_INTERVAL         10
  43
  44 #include "dhcpcd.h"
  45 #include "if.h"
  46
  47 #ifdef IN_IFF_DUPLICATED
  48 /* NetBSD gained RFC 5227 support in the kernel.
  49  * This means dhcpcd doesn't need ARP except for ARPing support. */
  50 #if defined(__NetBSD_Version__) && __NetBSD_Version__ >= 799003900
  51 #define KERNEL_RFC5227
  52 #endif
  53 #endif
  54
  55 struct arp_msg {
  56         uint16_t op;
  57         unsigned char sha[HWADDR_LEN];
  58         struct in_addr sip;
  59         unsigned char tha[HWADDR_LEN];
  60         struct in_addr tip;
  61 };
  62
  63 struct arp_state {
  64         TAILQ_ENTRY(arp_state) next;
  65         struct interface *iface;
  66
  67         void (*found_cb)(struct arp_state *, const struct arp_msg *);
  68         void (*not_found_cb)(struct arp_state *);
  69         void (*announced_cb)(struct arp_state *);
  70         void (*defend_failed_cb)(struct arp_state *);
  71         void (*free_cb)(struct arp_state *);
  72
  73         struct in_addr addr;
  74         int probes;
  75         int claims;
  76         struct timespec defend;
  77 };
  78 TAILQ_HEAD(arp_statehead, arp_state);
  79
  80 struct iarp_state {
  81         int bpf_fd;
  82         unsigned int bpf_flags;
  83         struct arp_statehead arp_states;
  84 };
  85
  86 #define ARP_STATE(ifp)                                                         \
  87         ((struct iarp_state *)(ifp)->if_data[IF_DATA_ARP])
  88 #define ARP_CSTATE(ifp)                                                        \
  89         ((const struct iarp_state *)(ifp)->if_data[IF_DATA_ARP])
  90
  91 #ifdef ARP
  92 struct arp_state *arp_new(struct interface *, const struct in_addr *);
  93 void arp_probe(struct arp_state *);
  94 void arp_announce(struct arp_state *);
  95 void arp_announceaddr(struct dhcpcd_ctx *, const struct in_addr *);
  96 void arp_ifannounceaddr(struct interface *, const struct in_addr *);
  97 void arp_cancel(struct arp_state *);
  98 void arp_free(struct arp_state *);
  99 void arp_freeaddr(struct interface *, const struct in_addr *);
 100 void arp_drop(struct interface *);
 101 #endif /* ARP */
 102 #endif /* ARP_H */