src/dhcp-common.h

   1 /* SPDX-License-Identifier: BSD-2-Clause */
   2 /*
   3  * dhcpcd - DHCP client daemon
   4  * Copyright (c) 2006-2021 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 DHCPCOMMON_H
  30 #define DHCPCOMMON_H
  31
  32 #include <arpa/inet.h>
  33 #include <netinet/in.h>
  34
  35 #include <stdint.h>
  36
  37 #include <arpa/nameser.h> /* after normal includes for sunos */
  38
  39 #include "common.h"
  40 #include "dhcpcd.h"
  41
  42 /* Support very old arpa/nameser.h as found in OpenBSD */
  43 #ifndef NS_MAXDNAME
  44 #define NS_MAXCDNAME MAXCDNAME
  45 #define NS_MAXDNAME MAXDNAME
  46 #define NS_MAXLABEL MAXLABEL
  47 #endif
  48
  49 /* Max MTU - defines dhcp option length */
  50 #define IP_UDP_SIZE               28
  51 #define MTU_MAX                 1500 - IP_UDP_SIZE
  52 #define MTU_MIN                  576 + IP_UDP_SIZE
  53
  54 #define OT_REQUEST              (1 << 0)
  55 #define OT_UINT8                (1 << 1)
  56 #define OT_INT8                 (1 << 2)
  57 #define OT_UINT16               (1 << 3)
  58 #define OT_INT16                (1 << 4)
  59 #define OT_UINT32               (1 << 5)
  60 #define OT_INT32                (1 << 6)
  61 #define OT_ADDRIPV4             (1 << 7)
  62 #define OT_STRING               (1 << 8)
  63 #define OT_ARRAY                (1 << 9)
  64 #define OT_RFC3361              (1 << 10)
  65 #define OT_RFC1035              (1 << 11)
  66 #define OT_RFC3442              (1 << 12)
  67 #define OT_OPTIONAL             (1 << 13)
  68 #define OT_ADDRIPV6             (1 << 14)
  69 #define OT_BINHEX               (1 << 15)
  70 #define OT_FLAG                 (1 << 16)
  71 #define OT_NOREQ                (1 << 17)
  72 #define OT_EMBED                (1 << 18)
  73 #define OT_ENCAP                (1 << 19)
  74 #define OT_INDEX                (1 << 20)
  75 #define OT_OPTION               (1 << 21)
  76 #define OT_DOMAIN               (1 << 22)
  77 #define OT_ASCII                (1 << 23)
  78 #define OT_RAW                  (1 << 24)
  79 #define OT_ESCSTRING            (1 << 25)
  80 #define OT_ESCFILE              (1 << 26)
  81 #define OT_BITFLAG              (1 << 27)
  82 #define OT_RESERVED             (1 << 28)
  83
  84 #define DHC_REQ(r, n, o) \
  85         (has_option_mask((r), (o)) && !has_option_mask((n), (o)))
  86
  87 #define DHC_REQOPT(o, r, n)                                               \
  88         (!((o)->type & OT_NOREQ) &&                                       \
  89          ((o)->type & OT_REQUEST || has_option_mask((r), (o)->option)) && \
  90           !has_option_mask((n), (o)->option))
  91
  92 struct dhcp_opt {
  93         uint32_t option; /* Also used for IANA Enterpise Number */
  94         int type;
  95         size_t len;
  96         char *var;
  97
  98         int index; /* Index counter for many instances of the same option */
  99         char bitflags[8];
 100
 101         /* Embedded options.
 102          * The option code is irrelevant here. */
 103         struct dhcp_opt *embopts;
 104         size_t embopts_len;
 105
 106         /* Encapsulated options */
 107         struct dhcp_opt *encopts;
 108         size_t encopts_len;
 109 };
 110
 111 const char *dhcp_get_hostname(char *, size_t, const struct if_options *);
 112 struct dhcp_opt *vivso_find(uint32_t, const void *);
 113
 114 ssize_t dhcp_vendor(char *, size_t);
 115
 116 void dhcp_print_option_encoding(const struct dhcp_opt *opt, int cols);
 117 #define add_option_mask(var, val) \
 118         ((var)[(val) >> 3] = (uint8_t)((var)[(val) >> 3] | 1 << ((val) & 7)))
 119 #define del_option_mask(var, val) \
 120         ((var)[(val) >> 3] = (uint8_t)((var)[(val) >> 3] & ~(1 << ((val) & 7))))
 121 #define has_option_mask(var, val) \
 122         ((var)[(val) >> 3] & (uint8_t)(1 << ((val) & 7)))
 123 int make_option_mask(const struct dhcp_opt *, size_t,
 124     const struct dhcp_opt *, size_t,
 125     uint8_t *, const char *, int);
 126
 127 size_t encode_rfc1035(const char *src, uint8_t *dst);
 128 ssize_t decode_rfc1035(char *, size_t, const uint8_t *, size_t);
 129 ssize_t print_string(char *, size_t, int, const uint8_t *, size_t);
 130 int dhcp_set_leasefile(char *, size_t, int, const struct interface *);
 131
 132 void dhcp_envoption(struct dhcpcd_ctx *,
 133     FILE *, const char *, const char *, struct dhcp_opt *,
 134     const uint8_t *(*dgetopt)(struct dhcpcd_ctx *,
 135     size_t *, unsigned int *, size_t *,
 136     const uint8_t *, size_t, struct dhcp_opt **),
 137     const uint8_t *od, size_t ol);
 138 void dhcp_zero_index(struct dhcp_opt *);
 139
 140 ssize_t dhcp_readfile(struct dhcpcd_ctx *, const char *, void *, size_t);
 141 ssize_t dhcp_writefile(struct dhcpcd_ctx *, const char *, mode_t,
 142     const void *, size_t);
 143 int dhcp_filemtime(struct dhcpcd_ctx *, const char *, time_t *);
 144 int dhcp_unlink(struct dhcpcd_ctx *, const char *);
 145 size_t dhcp_read_hwaddr_aton(struct dhcpcd_ctx *, uint8_t **, const char *);
 146 #endif