c7dc79e71d
Also fixes attacks possible via DHCPDECLINE / DHCPRELEASE function old new delta udhcpd_main 1846 1949 +103 send_renew 105 142 +37 send_NAK 61 - -61 send_ACK 180 - -180 ------------------------------------------------------------------------------ (add/remove: 0/2 grow/shrink: 2/0 up/down: 140/-241) Total: -101 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
202 lines
8.2 KiB
C
202 lines
8.2 KiB
C
/* vi: set sw=4 ts=4: */
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/* common.h
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*
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* Russ Dill <Russ.Dill@asu.edu> September 2001
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* Rewritten by Vladimir Oleynik <dzo@simtreas.ru> (C) 2003
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*
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* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
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*/
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#ifndef UDHCP_COMMON_H
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#define UDHCP_COMMON_H 1
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#include "libbb.h"
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#include <netinet/udp.h>
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#include <netinet/ip.h>
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PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
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#define DEFAULT_SCRIPT CONFIG_UDHCPC_DEFAULT_SCRIPT
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extern const uint8_t MAC_BCAST_ADDR[6]; /* six all-ones */
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/*** packet.h ***/
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/* DHCP protocol. See RFC 2131 */
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#define DHCP_MAGIC 0x63825363
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#define DHCP_OPTIONS_BUFSIZE 308
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#define BOOTREQUEST 1
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#define BOOTREPLY 2
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//TODO: rename ciaddr/yiaddr/chaddr
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struct dhcp_packet {
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uint8_t op; /* BOOTREQUEST or BOOTREPLY */
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uint8_t htype; /* hardware address type. 1 = 10mb ethernet */
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uint8_t hlen; /* hardware address length */
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uint8_t hops; /* used by relay agents only */
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uint32_t xid; /* unique id */
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uint16_t secs; /* elapsed since client began acquisition/renewal */
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uint16_t flags; /* only one flag so far: */
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#define BROADCAST_FLAG 0x8000 /* "I need broadcast replies" */
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uint32_t ciaddr; /* client IP (if client is in BOUND, RENEW or REBINDING state) */
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uint32_t yiaddr; /* 'your' (client) IP address */
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/* IP address of next server to use in bootstrap, returned in DHCPOFFER, DHCPACK by server */
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uint32_t siaddr_nip;
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uint32_t gateway_nip; /* relay agent IP address */
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uint8_t chaddr[16]; /* link-layer client hardware address (MAC) */
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uint8_t sname[64]; /* server host name (ASCIZ) */
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uint8_t file[128]; /* boot file name (ASCIZ) */
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uint32_t cookie; /* fixed first four option bytes (99,130,83,99 dec) */
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uint8_t options[DHCP_OPTIONS_BUFSIZE + CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS];
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} PACKED;
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#define DHCP_PKT_SNAME_LEN 64
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#define DHCP_PKT_FILE_LEN 128
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#define DHCP_PKT_SNAME_LEN_STR "64"
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#define DHCP_PKT_FILE_LEN_STR "128"
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struct ip_udp_dhcp_packet {
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struct iphdr ip;
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struct udphdr udp;
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struct dhcp_packet data;
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} PACKED;
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/* Let's see whether compiler understood us right */
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struct BUG_bad_sizeof_struct_ip_udp_dhcp_packet {
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char BUG_bad_sizeof_struct_ip_udp_dhcp_packet
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[(sizeof(struct ip_udp_dhcp_packet) != 576 + CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS) ? -1 : 1];
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};
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// RFC 2131 Table 5: Fields and options used by DHCP clients
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//
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// Field DHCPDISCOVER DHCPREQUEST DHCPDECLINE,
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// DHCPINFORM DHCPRELEASE
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// ----- ------------ ----------- -----------
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// 'op' BOOTREQUEST BOOTREQUEST BOOTREQUEST
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// 'hops' 0 0 0
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// 'xid' selected by client 'xid' from server selected by
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// DHCPOFFER message client
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// 'secs' 0 or seconds since 0 or seconds since 0
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// DHCP process started DHCP process started
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// 'flags' Set 'BROADCAST' Set 'BROADCAST' 0
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// flag if client flag if client
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// requires broadcast requires broadcast
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// reply reply
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// 'ciaddr' 0 (DHCPDISCOVER) 0 or client's 0 (DHCPDECLINE)
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// client's network address client's network
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// network address (BOUND/RENEW/REBIND) address
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// (DHCPINFORM) (DHCPRELEASE)
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// 'yiaddr' 0 0 0
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// 'siaddr' 0 0 0
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// 'giaddr' 0 0 0
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// 'chaddr' client's hardware client's hardware client's hardware
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// address address address
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// 'sname' options, if options, if (unused)
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// indicated in indicated in
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// 'sname/file' 'sname/file'
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// option; otherwise option; otherwise
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// unused unused
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// 'file' options, if options, if (unused)
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// indicated in indicated in
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// 'sname/file' 'sname/file'
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// option; otherwise option; otherwise
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// unused unused
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// 'options' options options (unused)
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//
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// Option DHCPDISCOVER DHCPREQUEST DHCPDECLINE,
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// DHCPINFORM DHCPRELEASE
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// ------ ------------ ----------- -----------
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// Requested IP address MAY MUST (in MUST
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// (DISCOVER) SELECTING or (DHCPDECLINE),
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// MUST NOT INIT-REBOOT) MUST NOT
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// (INFORM) MUST NOT (in (DHCPRELEASE)
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// BOUND or
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// RENEWING)
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// IP address lease time MAY MAY MUST NOT
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// (DISCOVER)
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// MUST NOT
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// (INFORM)
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// Use 'file'/'sname' fields MAY MAY MAY
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// Client identifier MAY MAY MAY
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// Vendor class identifier MAY MAY MUST NOT
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// Server identifier MUST NOT MUST (after MUST
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// SELECTING)
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// MUST NOT (after
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// INIT-REBOOT,
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// BOUND, RENEWING
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// or REBINDING)
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// Parameter request list MAY MAY MUST NOT
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// Maximum message size MAY MAY MUST NOT
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// Message SHOULD NOT SHOULD NOT SHOULD
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// Site-specific MAY MAY MUST NOT
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// All others MAY MAY MUST NOT
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uint16_t udhcp_checksum(void *addr, int count) FAST_FUNC;
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void udhcp_init_header(struct dhcp_packet *packet, char type) FAST_FUNC;
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/*int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd); - in dhcpc.h */
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int udhcp_recv_kernel_packet(struct dhcp_packet *packet, int fd) FAST_FUNC;
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int udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
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uint32_t source_ip, int source_port,
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uint32_t dest_ip, int dest_port, const uint8_t *dest_arp,
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int ifindex) FAST_FUNC;
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int udhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
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uint32_t source_ip, int source_port,
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uint32_t dest_ip, int dest_port) FAST_FUNC;
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/**/
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void udhcp_run_script(struct dhcp_packet *packet, const char *name) FAST_FUNC;
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// Still need to clean these up...
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/* from options.h */
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#define get_option udhcp_get_option
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#define end_option udhcp_end_option
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#define add_option_string udhcp_add_option_string
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#define add_simple_option udhcp_add_simple_option
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void udhcp_sp_setup(void) FAST_FUNC;
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int udhcp_sp_fd_set(fd_set *rfds, int extra_fd) FAST_FUNC;
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int udhcp_sp_read(const fd_set *rfds) FAST_FUNC;
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int udhcp_read_interface(const char *interface, int *ifindex, uint32_t *nip, uint8_t *mac) FAST_FUNC;
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int udhcp_raw_socket(int ifindex) FAST_FUNC;
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int udhcp_listen_socket(/*uint32_t ip,*/ int port, const char *inf) FAST_FUNC;
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/* Returns 1 if no reply received */
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int arpping(uint32_t test_nip,
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const uint8_t *safe_mac,
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uint32_t from_ip,
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uint8_t *from_mac,
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const char *interface) FAST_FUNC;
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#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
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extern unsigned dhcp_verbose;
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# define log1(...) do { if (dhcp_verbose >= 1) bb_info_msg(__VA_ARGS__); } while (0)
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# if CONFIG_UDHCP_DEBUG >= 2
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void udhcp_dump_packet(struct dhcp_packet *packet) FAST_FUNC;
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# define log2(...) do { if (dhcp_verbose >= 2) bb_info_msg(__VA_ARGS__); } while (0)
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# else
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# define udhcp_dump_packet(...) ((void)0)
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# define log2(...) ((void)0)
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# endif
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# if CONFIG_UDHCP_DEBUG >= 3
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# define log3(...) do { if (dhcp_verbose >= 3) bb_info_msg(__VA_ARGS__); } while (0)
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# else
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# define log3(...) ((void)0)
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# endif
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#else
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# define udhcp_dump_packet(...) ((void)0)
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# define log1(...) ((void)0)
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# define log2(...) ((void)0)
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# define log3(...) ((void)0)
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#endif
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POP_SAVED_FUNCTION_VISIBILITY
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#endif
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