8eeb8277e5
dhcpcd is a small DHCP client, supporting most, if not all, features of dhclient. It is much smaller (1/6 of the size on amd64), but still supports many of the more advanced modern RFCs like IPv4LL (RFC 3927), Classless Static Routes (RFC 3442) and Node-specific Client Identifiers (RFC 4361). It was written by Roy Marpled, partly in reply to the discussion of the DHCP client Sommer of Code project.
185 lines
6.4 KiB
C
185 lines
6.4 KiB
C
/*
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* dhcpcd - DHCP client daemon
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* Copyright 2006-2008 Roy Marples <roy@marples.name>
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* All rights reserved
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef DHCP_H
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#define DHCP_H
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#include <arpa/inet.h>
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#include <stdint.h>
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#include "config.h"
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#include "dhcpcd.h"
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#include "net.h"
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/* Max MTU - defines dhcp option length */
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#define MTU_MAX 1500
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#define MTU_MIN 576
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/* UDP port numbers for DHCP */
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#define DHCP_SERVER_PORT 67
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#define DHCP_CLIENT_PORT 68
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#define MAGIC_COOKIE 0x63825363
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#define BROADCAST_FLAG 0x8000
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/* DHCP message OP code */
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#define DHCP_BOOTREQUEST 1
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#define DHCP_BOOTREPLY 2
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/* DHCP message type */
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#define DHCP_DISCOVER 1
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#define DHCP_OFFER 2
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#define DHCP_REQUEST 3
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#define DHCP_DECLINE 4
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#define DHCP_ACK 5
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#define DHCP_NAK 6
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#define DHCP_RELEASE 7
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#define DHCP_INFORM 8
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/* DHCP options */
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enum DHCP_OPTIONS
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{
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DHCP_PAD = 0,
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DHCP_SUBNETMASK = 1,
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DHCP_ROUTER = 3,
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DHCP_DNSSERVER = 6,
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DHCP_HOSTNAME = 12,
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DHCP_DNSDOMAIN = 15,
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DHCP_BROADCAST = 28,
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DHCP_STATICROUTE = 33,
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DHCP_NISDOMAIN = 40,
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DHCP_NISSERVER = 41,
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DHCP_NTPSERVER = 42,
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DHCP_IPADDRESS = 50,
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DHCP_LEASETIME = 51,
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DHCP_OPTIONSOVERLOADED = 52,
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DHCP_MESSAGETYPE = 53,
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DHCP_SERVERID = 54,
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DHCP_PARAMETERREQUESTLIST = 55,
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DHCP_MESSAGE = 56,
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DHCP_MAXMESSAGESIZE = 57,
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DHCP_RENEWALTIME = 58,
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DHCP_REBINDTIME = 59,
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DHCP_CLASSID = 60,
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DHCP_CLIENTID = 61,
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DHCP_USERCLASS = 77, /* RFC 3004 */
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DHCP_FQDN = 81,
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DHCP_DNSSEARCH = 119, /* RFC 3397 */
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DHCP_CSR = 121, /* RFC 3442 */
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DHCP_MSCSR = 249, /* MS code for RFC 3442 */
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DHCP_END = 255
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};
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/* SetFQDNHostName values - lsnybble used in flags
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* byte (see buildmsg.c), hsnybble to create order
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* and to allow 0x00 to mean disable
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*/
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enum FQQN {
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FQDN_DISABLE = 0x00,
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FQDN_NONE = 0x18,
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FQDN_PTR = 0x20,
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FQDN_BOTH = 0x31
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};
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struct fqdn
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{
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uint8_t flags;
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uint8_t r1;
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uint8_t r2;
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char *name;
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};
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/* Sizes for DHCP options */
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#define DHCP_CHADDR_LEN 16
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#define SERVERNAME_LEN 64
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#define BOOTFILE_LEN 128
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#define DHCP_UDP_LEN (20 + 8)
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#define DHCP_BASE_LEN (4 + 4 + 2 + 2 + 4 + 4 + 4 + 4 + 4)
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#define DHCP_RESERVE_LEN (4 + 4 + 4 + 4 + 2)
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#define DHCP_FIXED_LEN (DHCP_BASE_LEN + DHCP_CHADDR_LEN + \
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+ SERVERNAME_LEN + BOOTFILE_LEN)
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#define DHCP_OPTION_LEN (MTU_MAX - DHCP_FIXED_LEN - DHCP_UDP_LEN \
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- DHCP_RESERVE_LEN)
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/* Some crappy DHCP servers require the BOOTP minimum length */
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#define BOOTP_MESSAGE_LENTH_MIN 300
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struct dhcp_message {
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uint8_t op; /* message type */
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uint8_t hwtype; /* hardware address type */
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uint8_t hwlen; /* hardware address length */
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uint8_t hwopcount; /* should be zero in client message */
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uint32_t xid; /* transaction id */
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uint16_t secs; /* elapsed time in sec. from boot */
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uint16_t flags;
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uint32_t ciaddr; /* (previously allocated) client IP */
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uint32_t yiaddr; /* 'your' client IP address */
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uint32_t siaddr; /* should be zero in client's messages */
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uint32_t giaddr; /* should be zero in client's messages */
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uint8_t chaddr[DHCP_CHADDR_LEN]; /* client's hardware address */
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uint8_t servername[SERVERNAME_LEN]; /* server host name */
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uint8_t bootfile[BOOTFILE_LEN]; /* boot file name */
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uint32_t cookie;
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uint8_t options[DHCP_OPTION_LEN]; /* message options - cookie */
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};
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struct dhcp_lease {
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struct in_addr addr;
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struct in_addr net;
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uint32_t leasetime;
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uint32_t renewaltime;
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uint32_t rebindtime;
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struct in_addr server;
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uint32_t leasedfrom;
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uint8_t frominfo;
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};
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#define add_reqmask(var, val) (var[val >> 3] |= 1 << (val & 7))
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#define del_reqmask(var, val) (var[val >> 3] &= ~(1 << (val & 7)))
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#define has_reqmask(var, val) (var[val >> 3] & (1 << (val & 7)))
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int make_reqmask(uint8_t *, char **, int);
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void print_options(void);
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//const uint8_t *get_option(const struct dhcp_message *, uint8_t);
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char *get_option_string(const struct dhcp_message *, uint8_t);
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int get_option_addr(uint32_t *, const struct dhcp_message *, uint8_t);
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int get_option_uint32(uint32_t *, const struct dhcp_message *, uint8_t);
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int get_option_uint16(uint16_t *, const struct dhcp_message *, uint8_t);
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int get_option_uint8(uint8_t *, const struct dhcp_message *, uint8_t);
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struct rt *get_option_routes(const struct dhcp_message *);
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ssize_t configure_env(char **, const char *, const struct dhcp_message *,
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const struct options *);
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ssize_t make_message(struct dhcp_message **,
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const struct interface *, const struct dhcp_lease *,
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uint32_t, uint8_t, const struct options *);
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int valid_dhcp_packet(unsigned char *);
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ssize_t write_lease(const struct interface *, const struct dhcp_message *);
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struct dhcp_message *read_lease(const struct interface *iface);
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#endif
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