mirror of
https://github.com/pi-hole/dnsmasq.git
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Implement RFC-4388 DHCPv4 leasequery.
This commit is contained in:
Simon Kelley
692
contrib/leasequery/leasequery.c
Normal file
692
contrib/leasequery/leasequery.c
Normal file
@@ -0,0 +1,692 @@
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/* leasequery is Copyright (c) 2025 Simon Kelley
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 dated June, 1991, or
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(at your option) version 3 dated 29 June, 2007.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/* Author's email: simon@thekelleys.org.uk */
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#include <sys/socket.h>
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#include <sys/ioctl.h>
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#include <sys/select.h>
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#include <sys/time.h>
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#include <sys/stat.h>
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#include <limits.h>
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#include <net/if.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <time.h>
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#include <errno.h>
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#include <pwd.h>
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#include <grp.h>
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#include <netdb.h>
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#include <linux/types.h>
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#include <linux/capability.h>
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#include <arpa/inet.h>
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#include <ctype.h>
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typedef unsigned char u8;
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typedef unsigned short u16;
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typedef unsigned int u32;
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typedef unsigned long long u64;
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#define INADDRSZ 4
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#define ADDRSTRLEN 46
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#define option_len(opt) ((int)(((unsigned char *)(opt))[1]))
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#define option_ptr(opt, i) ((void *)&(((unsigned char *)(opt))[2u+(unsigned int)(i)]))
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#define DHCP_CHADDR_MAX 16
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#define DHCP_SERVER_PORT 67
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#define DHCP_CLIENT_PORT 68
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#define BOOTREQUEST 1
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#define BOOTREPLY 2
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#define DHCP_COOKIE 0x63825363
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#define DHCPLEASEQUERY 10
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#define DHCPLEASEUNASSIGNED 11
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#define DHCPLEASEUNKNOWN 12
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#define DHCPLEASEACTIVE 13
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#define OPTION_END 255
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#define OPTION_ROUTER 3
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#define OPTION_VENDOR_CLASS_OPT 43
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#define OPTION_LEASE_TIME 51
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#define OPTION_MESSAGE_TYPE 53
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#define OPTION_SERVER_IDENTIFIER 54
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#define OPTION_REQUESTED_OPTIONS 55
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#define OPTION_VENDOR_ID 60
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#define OPTION_CLIENT_ID 61
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/* flags in top of length field for DHCP-option tables */
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#define OT_ADDR_LIST 0x8000
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#define OT_RFC1035_NAME 0x4000
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#define OT_INTERNAL 0x2000
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#define OT_NAME 0x1000
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#define OT_CSTRING 0x0800
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#define OT_DEC 0x0400
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#define OT_TIME 0x0200
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#define GETSHORT(s, cp) do { \
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unsigned char *t_cp = (unsigned char *)(cp); \
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(s) = ((u16)t_cp[0] << 8) \
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| ((u16)t_cp[1]) \
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; \
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(cp) += 2; \
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} while(0)
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#define GETLONG(l, cp) do { \
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unsigned char *t_cp = (unsigned char *)(cp); \
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(l) = ((u32)t_cp[0] << 24) \
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| ((u32)t_cp[1] << 16) \
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| ((u32)t_cp[2] << 8) \
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| ((u32)t_cp[3]) \
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; \
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(cp) += 4; \
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} while (0)
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#define PUTSHORT(s, cp) do { \
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u16 t_s = (u16)(s); \
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unsigned char *t_cp = (unsigned char *)(cp); \
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*t_cp++ = t_s >> 8; \
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*t_cp = t_s; \
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(cp) += 2; \
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} while(0)
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#define PUTLONG(l, cp) do { \
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u32 t_l = (u32)(l); \
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unsigned char *t_cp = (unsigned char *)(cp); \
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*t_cp++ = t_l >> 24; \
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*t_cp++ = t_l >> 16; \
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*t_cp++ = t_l >> 8; \
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*t_cp = t_l; \
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(cp) += 4; \
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} while (0)
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union all_addr {
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struct in_addr addr4;
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struct in6_addr addr6;
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};
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struct dhcp_packet_with_opts{
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struct dhcp_packet {
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unsigned char op, htype, hlen, hops;
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unsigned int xid;
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unsigned short secs, flags;
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struct in_addr ciaddr, yiaddr, siaddr, giaddr;
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unsigned char chaddr[DHCP_CHADDR_MAX], sname[64], file[128];
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} header;
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unsigned char options[312];
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};
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static const struct opttab_t {
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char *name;
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u16 val, size;
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} opttab[] = {
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{ "netmask", 1, OT_ADDR_LIST },
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{ "time-offset", 2, 4 },
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{ "router", 3, OT_ADDR_LIST },
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{ "dns-server", 6, OT_ADDR_LIST },
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{ "log-server", 7, OT_ADDR_LIST },
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{ "lpr-server", 9, OT_ADDR_LIST },
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{ "hostname", 12, OT_INTERNAL | OT_NAME },
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{ "boot-file-size", 13, 2 | OT_DEC },
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{ "domain-name", 15, OT_NAME },
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{ "swap-server", 16, OT_ADDR_LIST },
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{ "root-path", 17, OT_NAME },
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{ "extension-path", 18, OT_NAME },
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{ "ip-forward-enable", 19, 1 },
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{ "non-local-source-routing", 20, 1 },
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{ "policy-filter", 21, OT_ADDR_LIST },
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{ "max-datagram-reassembly", 22, 2 | OT_DEC },
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{ "default-ttl", 23, 1 | OT_DEC },
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{ "mtu", 26, 2 | OT_DEC },
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{ "all-subnets-local", 27, 1 },
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{ "broadcast", 28, OT_INTERNAL | OT_ADDR_LIST },
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{ "router-discovery", 31, 1 },
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{ "router-solicitation", 32, OT_ADDR_LIST },
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{ "static-route", 33, OT_ADDR_LIST },
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{ "trailer-encapsulation", 34, 1 },
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{ "arp-timeout", 35, 4 | OT_DEC },
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{ "ethernet-encap", 36, 1 },
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{ "tcp-ttl", 37, 1 },
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{ "tcp-keepalive", 38, 4 | OT_DEC },
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{ "nis-domain", 40, OT_NAME },
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{ "nis-server", 41, OT_ADDR_LIST },
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{ "ntp-server", 42, OT_ADDR_LIST },
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{ "vendor-encap", 43, OT_INTERNAL },
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{ "netbios-ns", 44, OT_ADDR_LIST },
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{ "netbios-dd", 45, OT_ADDR_LIST },
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{ "netbios-nodetype", 46, 1 },
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{ "netbios-scope", 47, 0 },
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{ "x-windows-fs", 48, OT_ADDR_LIST },
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{ "x-windows-dm", 49, OT_ADDR_LIST },
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{ "requested-address", 50, OT_INTERNAL | OT_ADDR_LIST },
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{ "lease-time", 51, OT_INTERNAL | OT_TIME },
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{ "option-overload", 52, OT_INTERNAL },
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{ "message-type", 53, OT_INTERNAL | OT_DEC },
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{ "server-identifier", 54, OT_INTERNAL | OT_ADDR_LIST },
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{ "parameter-request", 55, OT_INTERNAL },
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{ "message", 56, OT_INTERNAL },
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{ "max-message-size", 57, OT_INTERNAL },
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{ "T1", 58, OT_TIME},
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{ "T2", 59, OT_TIME},
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{ "vendor-class", 60, OT_NAME },
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{ "client-id", 61, OT_INTERNAL },
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{ "nis+-domain", 64, OT_NAME },
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{ "nis+-server", 65, OT_ADDR_LIST },
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{ "tftp-server", 66, OT_NAME },
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{ "bootfile-name", 67, OT_NAME },
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{ "mobile-ip-home", 68, OT_ADDR_LIST },
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{ "smtp-server", 69, OT_ADDR_LIST },
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{ "pop3-server", 70, OT_ADDR_LIST },
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{ "nntp-server", 71, OT_ADDR_LIST },
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{ "irc-server", 74, OT_ADDR_LIST },
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{ "user-class", 77, 0 },
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{ "rapid-commit", 80, 0 },
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{ "FQDN", 81, OT_INTERNAL },
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{ "agent-info", 82, OT_INTERNAL },
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{ "last-transaction", 91, 4 | OT_TIME },
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{ "associated-ip", 92, OT_ADDR_LIST },
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{ "client-arch", 93, 2 | OT_DEC },
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{ "client-interface-id", 94, 0 },
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{ "client-machine-id", 97, 0 },
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{ "posix-timezone", 100, OT_NAME }, /* RFC 4833, Sec. 2 */
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{ "tzdb-timezone", 101, OT_NAME }, /* RFC 4833, Sec. 2 */
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{ "ipv6-only", 108, 4 | OT_DEC }, /* RFC 8925 */
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{ "subnet-select", 118, OT_INTERNAL },
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{ "domain-search", 119, OT_RFC1035_NAME },
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{ "sip-server", 120, 0 },
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{ "classless-static-route", 121, 0 },
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{ "vendor-id-encap", 125, 0 },
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{ "tftp-server-address", 150, OT_ADDR_LIST },
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{ "server-ip-address", 255, OT_ADDR_LIST }, /* special, internal only, sets siaddr */
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{ NULL, 0, 0 }
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};
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static void prettyprint_time(char *buf, unsigned int t);
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static char *print_mac(char *buff, unsigned char *mac, int len);
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int lookup_dhcp_opt(char *name)
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{
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const struct opttab_t *t = opttab;
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int i;
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for (i = 0; t[i].name; i++)
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if (strcasecmp(t[i].name, name) == 0)
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return t[i].val;
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return -1;
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}
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char *option_string(unsigned int opt, unsigned char *val, int opt_len, char *buf, int buf_len)
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{
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int o, i, j, nodecode = 0;
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const struct opttab_t *ot = opttab;
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char addrbuff[ADDRSTRLEN];
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for (o = 0; ot[o].name; o++)
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if (ot[o].val == opt)
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{
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if (buf)
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{
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memset(buf, 0, buf_len);
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if (ot[o].size & OT_ADDR_LIST)
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{
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union all_addr addr;
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int addr_len = INADDRSZ;
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for (buf[0]= 0, i = 0; i <= opt_len - addr_len; i += addr_len)
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{
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if (i != 0)
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strncat(buf, ", ", buf_len - strlen(buf));
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/* align */
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memcpy(&addr, &val[i], addr_len);
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inet_ntop(AF_INET, &val[i], addrbuff, ADDRSTRLEN);
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strncat(buf, addrbuff, buf_len - strlen(buf));
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}
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}
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else if (ot[o].size & OT_NAME)
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for (i = 0, j = 0; i < opt_len && j < buf_len ; i++)
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{
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char c = val[i];
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if (isprint((unsigned char)c))
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buf[j++] = c;
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}
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else if ((ot[o].size & (OT_DEC | OT_TIME)) && opt_len != 0)
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{
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unsigned int dec = 0;
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for (i = 0; i < opt_len; i++)
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dec = (dec << 8) | val[i];
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if (ot[o].size & OT_TIME)
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prettyprint_time(buf, dec);
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else
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sprintf(buf, "%u", dec);
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}
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else
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nodecode = 1;
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}
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break;
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}
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if (opt_len != 0 && buf && (!ot[o].name || nodecode))
|
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{
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int trunc = 0;
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if (opt_len > 14)
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{
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trunc = 1;
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opt_len = 14;
|
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}
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print_mac(buf, val, opt_len);
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if (trunc)
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strncat(buf, "...", buf_len - strlen(buf));
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|
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}
|
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return ot[o].name ? ot[o].name : "";
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}
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static void prettyprint_time(char *buf, unsigned int t)
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{
|
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if (t == 0xffffffff)
|
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sprintf(buf, "infinite");
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else
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{
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unsigned int x, p = 0;
|
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if ((x = t/86400))
|
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p += sprintf(&buf[p], "%ud", x);
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if ((x = (t/3600)%24))
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p += sprintf(&buf[p], "%uh", x);
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if ((x = (t/60)%60))
|
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p += sprintf(&buf[p], "%um", x);
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if ((x = t%60))
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sprintf(&buf[p], "%us", x);
|
||||
}
|
||||
}
|
||||
|
||||
static char *print_mac(char *buff, unsigned char *mac, int len)
|
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{
|
||||
char *p = buff;
|
||||
int i;
|
||||
|
||||
if (len == 0)
|
||||
sprintf(p, "<null>");
|
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else
|
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for (i = 0; i < len; i++)
|
||||
p += sprintf(p, "%.2x%s", mac[i], (i == len - 1) ? "" : ":");
|
||||
|
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return buff;
|
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}
|
||||
|
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static unsigned char *dhcp_skip_opts(struct dhcp_packet_with_opts *pktp)
|
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{
|
||||
unsigned char *start = (unsigned char *)(((unsigned int *)&pktp->options[0]) + 1);
|
||||
while (*start != 0)
|
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start += start[1] + 2;
|
||||
return start;
|
||||
}
|
||||
|
||||
static unsigned char *dhcp_find_opt(struct dhcp_packet_with_opts *pktp, int optno)
|
||||
{
|
||||
unsigned char *start = (unsigned char *)(((unsigned int *)&pktp->options[0]) + 1);
|
||||
while (*start != OPTION_END)
|
||||
{
|
||||
if (*start == optno)
|
||||
return start;
|
||||
start += start[1] + 2;
|
||||
}
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static void option_put(struct dhcp_packet_with_opts *pktp, int opt, int len, unsigned int val)
|
||||
{
|
||||
int i;
|
||||
unsigned char *p = dhcp_skip_opts(pktp);
|
||||
|
||||
if (p)
|
||||
{
|
||||
*p++ = opt;
|
||||
*p++ = len;
|
||||
for (i = 0; i < len; i++)
|
||||
*(p++) = val >> (8 * (len - (i + 1)));
|
||||
}
|
||||
}
|
||||
|
||||
static void option_put_string(struct dhcp_packet_with_opts *pktp, int opt,
|
||||
const char *string, int null_term)
|
||||
{
|
||||
unsigned char *p;
|
||||
size_t len = strlen(string);
|
||||
|
||||
if (null_term && len != 255)
|
||||
len++;
|
||||
|
||||
if ((p = dhcp_skip_opts(pktp)))
|
||||
{
|
||||
*p++ = opt;
|
||||
*p++ = len;
|
||||
memcpy(p, string, len);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
/* in may equal out, when maxlen may be -1 (No max len).
|
||||
Return -1 for extraneous no-hex chars found. */
|
||||
int parse_hex(char *in, unsigned char *out, int maxlen,
|
||||
unsigned int *wildcard_mask, int *mac_type)
|
||||
{
|
||||
int done = 0, mask = 0, i = 0;
|
||||
char *r;
|
||||
|
||||
if (mac_type)
|
||||
*mac_type = 0;
|
||||
|
||||
while (!done && (maxlen == -1 || i < maxlen))
|
||||
{
|
||||
for (r = in; *r != 0 && *r != ':' && *r != '-' && *r != ' '; r++)
|
||||
if (*r != '*' && !isxdigit((unsigned char)*r))
|
||||
return -1;
|
||||
|
||||
if (*r == 0)
|
||||
done = 1;
|
||||
|
||||
if (r != in )
|
||||
{
|
||||
if (*r == '-' && i == 0 && mac_type)
|
||||
{
|
||||
*r = 0;
|
||||
*mac_type = strtol(in, NULL, 16);
|
||||
mac_type = NULL;
|
||||
}
|
||||
else
|
||||
{
|
||||
*r = 0;
|
||||
if (strcmp(in, "*") == 0)
|
||||
{
|
||||
mask = (mask << 1) | 1;
|
||||
i++;
|
||||
}
|
||||
else
|
||||
{
|
||||
int j, bytes = (1 + (r - in))/2;
|
||||
for (j = 0; j < bytes; j++)
|
||||
{
|
||||
char sav;
|
||||
if (j < bytes - 1)
|
||||
{
|
||||
sav = in[(j+1)*2];
|
||||
in[(j+1)*2] = 0;
|
||||
}
|
||||
/* checks above allow mix of hexdigit and *, which
|
||||
is illegal. */
|
||||
if (strchr(&in[j*2], '*'))
|
||||
return -1;
|
||||
out[i] = strtol(&in[j*2], NULL, 16);
|
||||
mask = mask << 1;
|
||||
if (++i == maxlen)
|
||||
break;
|
||||
if (j < bytes - 1)
|
||||
in[(j+1)*2] = sav;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
in = r+1;
|
||||
}
|
||||
|
||||
if (wildcard_mask)
|
||||
*wildcard_mask = mask;
|
||||
|
||||
return i;
|
||||
}
|
||||
|
||||
static char *split_chr(char *s, char c)
|
||||
{
|
||||
char *comma, *p;
|
||||
|
||||
if (!s || !(comma = strchr(s, c)))
|
||||
return NULL;
|
||||
|
||||
p = comma;
|
||||
*comma = ' ';
|
||||
|
||||
for (; *comma == ' '; comma++);
|
||||
|
||||
for (; (p >= s) && *p == ' '; p--)
|
||||
*p = 0;
|
||||
|
||||
return comma;
|
||||
}
|
||||
|
||||
static char *split(char *s)
|
||||
{
|
||||
return split_chr(s, ',');
|
||||
}
|
||||
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
int fd;
|
||||
struct ifreq ifr;
|
||||
struct in_addr iface_addr, server_addr, lease_addr;
|
||||
struct dhcp_packet_with_opts pkt;
|
||||
struct sockaddr_in saddr;
|
||||
unsigned char *p;
|
||||
ssize_t sz;
|
||||
unsigned char mac[DHCP_CHADDR_MAX], clid[256], req_options[256];
|
||||
char buff[500];
|
||||
int clid_len = 0, mac_len = 0, mac_type = 0, opts_len = 0;
|
||||
unsigned short port = DHCP_SERVER_PORT;
|
||||
unsigned int xid;
|
||||
struct timeval tv;
|
||||
|
||||
gettimeofday(&tv, NULL);
|
||||
srand(tv.tv_usec);
|
||||
xid = rand();
|
||||
server_addr.s_addr = lease_addr.s_addr = iface_addr.s_addr = 0;
|
||||
|
||||
if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
|
||||
{
|
||||
perror("leasequery: cannot create socket");
|
||||
exit(1);
|
||||
}
|
||||
|
||||
while (1)
|
||||
{
|
||||
int option = getopt(argc, argv, "i:s:l:m:c:p:r:");
|
||||
|
||||
if (option == -1)
|
||||
break;
|
||||
|
||||
switch (option)
|
||||
{
|
||||
default:
|
||||
fprintf(stderr,
|
||||
"-p <port> port on DHCP server.\n"
|
||||
"-i <interface> exit interface to DHCP server.\n"
|
||||
"-s <inet-addr> DHCP server address.\n"
|
||||
"-l <inet-addr> Query lease by IP address.\n"
|
||||
"-m <MAC-addr> Query lease by MAC address.\n"
|
||||
"-c <hex> Query lease by client-id.\n"
|
||||
"-r <name>|<int>[,...] List of options to return.\n");
|
||||
exit(1);
|
||||
|
||||
case 'p':
|
||||
port = atoi(optarg);
|
||||
break;
|
||||
|
||||
case 'i':
|
||||
strncpy(ifr.ifr_name, optarg, IF_NAMESIZE);
|
||||
ifr.ifr_addr.sa_family = AF_INET;
|
||||
if (ioctl(fd, SIOCGIFADDR, &ifr) == -1)
|
||||
{
|
||||
perror("leasequery: cannot get interface address");
|
||||
exit(1);
|
||||
}
|
||||
|
||||
iface_addr = ((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr;
|
||||
break;
|
||||
|
||||
case 's':
|
||||
if (inet_pton(AF_INET, optarg, &server_addr) <= 0)
|
||||
{
|
||||
fprintf(stderr, "leasequery: bad server address\n");
|
||||
exit(1);
|
||||
}
|
||||
break;
|
||||
|
||||
case 'l':
|
||||
if (inet_pton(AF_INET, optarg, &lease_addr) <= 0)
|
||||
{
|
||||
fprintf(stderr, "leasequery: bad lease address\n");
|
||||
exit(1);
|
||||
}
|
||||
break;
|
||||
|
||||
case 'm':
|
||||
mac_type = 1; /* default ethernet */
|
||||
mac_len = parse_hex(optarg, mac, DHCP_CHADDR_MAX, NULL, &mac_type);
|
||||
if (!mac_type)
|
||||
mac_type = 1; /* default ethernet */
|
||||
break;
|
||||
|
||||
case 'c':
|
||||
clid_len = parse_hex(optarg, clid, 256, NULL, NULL);
|
||||
break;
|
||||
|
||||
case 'r':
|
||||
{
|
||||
char *comma;
|
||||
int opt;
|
||||
|
||||
while (optarg)
|
||||
{
|
||||
comma = split(optarg);
|
||||
|
||||
if ((opt = lookup_dhcp_opt(optarg)) != -1 || (opt = atoi(optarg)) != 0)
|
||||
req_options[opts_len++] = opt;
|
||||
|
||||
optarg = comma;
|
||||
}
|
||||
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if (!server_addr.s_addr)
|
||||
{
|
||||
fprintf(stderr, "leasequery: no server address\n");
|
||||
exit(1);
|
||||
}
|
||||
|
||||
memset(&pkt, 0, sizeof pkt);
|
||||
pkt.header.op = BOOTREQUEST;
|
||||
pkt.header.xid = xid;
|
||||
pkt.header.ciaddr = lease_addr;
|
||||
pkt.header.hlen = mac_len;
|
||||
pkt.header.htype = mac_type;
|
||||
memcpy(pkt.header.chaddr, mac, mac_len);
|
||||
*((unsigned int *)&pkt.options[0]) = htonl(DHCP_COOKIE);
|
||||
|
||||
/* Dnsmasq extension. */
|
||||
pkt.header.giaddr.s_addr = iface_addr.s_addr ? iface_addr.s_addr : INADDR_BROADCAST;
|
||||
|
||||
option_put(&pkt, OPTION_MESSAGE_TYPE, 1, DHCPLEASEQUERY);
|
||||
|
||||
if (clid_len != 0)
|
||||
{
|
||||
p = dhcp_skip_opts(&pkt);
|
||||
*p++ = OPTION_CLIENT_ID;
|
||||
*p++ = clid_len;
|
||||
memcpy(p, clid, clid_len);
|
||||
}
|
||||
|
||||
if (opts_len != 0)
|
||||
{
|
||||
p = dhcp_skip_opts(&pkt);
|
||||
*p++ = OPTION_REQUESTED_OPTIONS;
|
||||
*p++ = opts_len;
|
||||
memcpy(p, req_options, opts_len);
|
||||
}
|
||||
|
||||
if (iface_addr.s_addr)
|
||||
{
|
||||
saddr.sin_family = AF_INET;
|
||||
saddr.sin_port = htons(port);
|
||||
saddr.sin_addr.s_addr = iface_addr.s_addr;
|
||||
|
||||
if (bind(fd, (struct sockaddr *)&saddr, sizeof(struct sockaddr_in)))
|
||||
{
|
||||
perror("leasequery: cannot bind DHCP server socket");
|
||||
exit(1);
|
||||
}
|
||||
}
|
||||
|
||||
saddr.sin_family = AF_INET;
|
||||
saddr.sin_port = htons(port);
|
||||
saddr.sin_addr = server_addr;
|
||||
|
||||
while((sz = sendto(fd, &pkt, dhcp_skip_opts(&pkt) - ((unsigned char *)&pkt), 0, (struct sockaddr *)&saddr, sizeof(saddr))) == -1 &&
|
||||
errno == EINTR);
|
||||
|
||||
if (sz == -1)
|
||||
{
|
||||
perror("leasequery: sendto()");
|
||||
exit(1);
|
||||
}
|
||||
|
||||
sz = recv(fd, &pkt, sizeof(pkt), 0);
|
||||
|
||||
if (sz == -1)
|
||||
{
|
||||
perror("leasequery: recv()");
|
||||
exit(1);
|
||||
}
|
||||
|
||||
if (sz >= sizeof(pkt.header) &&
|
||||
pkt.header.op == BOOTREPLY &&
|
||||
(p = dhcp_find_opt(&pkt, OPTION_MESSAGE_TYPE)) &&
|
||||
pkt.header.xid == xid)
|
||||
{
|
||||
if (p[2] == DHCPLEASEUNASSIGNED)
|
||||
printf("UNASSIGNED\n");
|
||||
else if (p[2] == DHCPLEASEUNKNOWN)
|
||||
printf("UNKNOWN\n");
|
||||
else if (p[2] == DHCPLEASEACTIVE)
|
||||
{
|
||||
print_mac(buff, pkt.header.chaddr, pkt.header.hlen);
|
||||
printf("ACTIVE %s %s\n", inet_ntoa(pkt.header.ciaddr), buff);
|
||||
|
||||
p = (unsigned char *)(((unsigned int *)&pkt.options[0]) + 1);
|
||||
|
||||
while (*p != OPTION_END)
|
||||
{
|
||||
char *optname = option_string(p[0], option_ptr(p, 0), option_len(p), buff, 500);
|
||||
|
||||
printf("size:%3d option:%3d %s %s\n", option_len(p), p[0], optname, buff);
|
||||
p += p[1] + 2;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user