src/dnsmasq.h

/* dnsmasq is Copyright (c) 2000-2024 Simon Kelley
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 dated June, 1991, or
   (at your option) version 3 dated 29 June, 2007.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
     
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#define COPYRIGHT "Copyright (c) 2000-2024 Simon Kelley"

/* We do defines that influence behavior of stdio.h, so complain
   if included too early. */
#ifdef _STDIO_H
#  error "Header file stdio.h included too early!"
#endif 

#ifndef NO_LARGEFILE
/* Ensure we can use files >2GB (log files may grow this big) */
#  define _LARGEFILE_SOURCE 1
#  define _FILE_OFFSET_BITS 64
#endif

/* Get linux C library versions and define _GNU_SOURCE for kFreeBSD. */
#if defined(__linux__) || defined(__GLIBC__)
#  ifndef __ANDROID__
#      define _GNU_SOURCE
#  endif
#  include <features.h> 
#endif

/* Need these defined early */
#if defined(__sun) || defined(__sun__)
#  define _XPG4_2
#  define __EXTENSIONS__
#endif

#if (defined(__GNUC__) && __GNUC__ >= 3) || defined(__clang__)
#define ATTRIBUTE_NORETURN __attribute__ ((noreturn))
#else
#define ATTRIBUTE_NORETURN
#endif

/* get these before config.h  for IPv6 stuff... */
#include <sys/types.h> 
#include <sys/socket.h>

#ifdef __APPLE__
/* Define before netinet/in.h to select API. OSX Lion onwards. */
#  define __APPLE_USE_RFC_3542
#endif
#include <netinet/in.h>

/* Also needed before config.h. */
#include <getopt.h>

#include "config.h"
#include "ip6addr.h"
#include "metrics.h"

typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned int u32;
typedef unsigned long long u64;

#define countof(x)      (long)(sizeof(x) / sizeof(x[0]))
#define MIN(a,b)        ((a) < (b) ? (a) : (b))

#include "dns-protocol.h"
#include "dhcp-protocol.h"
#ifdef HAVE_DHCP6
#include "dhcp6-protocol.h"
#include "radv-protocol.h"
#endif

#define gettext_noop(S) (S)
#ifndef LOCALEDIR
#  define _(S) (S)
#else
#  include <libintl.h>
#  include <locale.h>   
#  define _(S) gettext(S)
#endif

#include <arpa/inet.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#if defined(HAVE_SOLARIS_NETWORK)
#  include <sys/sockio.h>
#endif
#include <poll.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <sys/un.h>
#include <limits.h>
#include <net/if.h>
#if defined(HAVE_SOLARIS_NETWORK) && !defined(ifr_mtu)
/* Some solaris net/if./h omit this. */
#  define ifr_mtu  ifr_ifru.ifru_metric
#endif
#include <unistd.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <ctype.h>
#include <signal.h>
#include <stddef.h>
#include <time.h>
#include <errno.h>
#include <pwd.h>
#include <grp.h>
#include <stdarg.h>
#if defined(__OpenBSD__) || defined(__NetBSD__) || defined(__sun__) || defined (__sun) || defined (__ANDROID__)
#  include <netinet/if_ether.h>
#else
#  include <net/ethernet.h>
#endif
#include <net/if_arp.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <netinet/ip_icmp.h>
#include <netinet/tcp.h>
#include <sys/uio.h>
#include <syslog.h>
#include <dirent.h>
#include <netdb.h>
#ifndef HAVE_LINUX_NETWORK
#  include <net/if_dl.h>
#endif

#if defined(HAVE_LINUX_NETWORK)
#include <linux/version.h>
#include <linux/sockios.h>
#include <linux/capability.h>
/* There doesn't seem to be a universally-available 
   userspace header for these. */
extern int capset(cap_user_header_t header, cap_user_data_t data);
extern int capget(cap_user_header_t header, cap_user_data_t data);
#define LINUX_CAPABILITY_VERSION_1  0x19980330
#define LINUX_CAPABILITY_VERSION_2  0x20071026
#define LINUX_CAPABILITY_VERSION_3  0x20080522

#include <sys/prctl.h>
#elif defined(HAVE_SOLARIS_NETWORK)
#include <priv.h>
#endif

/* Backwards compat with 2.83 */
#if defined(HAVE_NETTLEHASH)
#  define HAVE_CRYPTOHASH
#endif
#if defined(HAVE_DNSSEC) || defined(HAVE_CRYPTOHASH)
#  include <nettle/nettle-meta.h>
#endif

/* daemon is function in the C library.... */
#define daemon dnsmasq_daemon

#define ADDRSTRLEN INET6_ADDRSTRLEN

/* Async event queue */
struct event_desc {
  int event, data, msg_sz;
};

#define EVENT_RELOAD     1
#define EVENT_DUMP       2
#define EVENT_ALARM      3
#define EVENT_TERM       4
#define EVENT_CHILD      5
#define EVENT_REOPEN     6
#define EVENT_EXITED     7
#define EVENT_KILLED     8
#define EVENT_EXEC_ERR   9
#define EVENT_PIPE_ERR   10
#define EVENT_USER_ERR   11
#define EVENT_CAP_ERR    12
#define EVENT_PIDFILE    13
#define EVENT_HUSER_ERR  14
#define EVENT_GROUP_ERR  15
#define EVENT_DIE        16
#define EVENT_LOG_ERR    17
#define EVENT_FORK_ERR   18
#define EVENT_LUA_ERR    19
#define EVENT_TFTP_ERR   20
#define EVENT_INIT       21
#define EVENT_NEWADDR    22
#define EVENT_NEWROUTE   23
#define EVENT_TIME_ERR   24
#define EVENT_SCRIPT_LOG 25
#define EVENT_TIME       26

/* Exit codes. */
#define EC_GOOD        0
#define EC_BADCONF     1
#define EC_BADNET      2
#define EC_FILE        3
#define EC_NOMEM       4
#define EC_MISC        5
#define EC_INIT_OFFSET 10

#define OPT_BOGUSPRIV      0
#define OPT_FILTER         1
#define OPT_LOG            2
#define OPT_SELFMX         3
#define OPT_NO_HOSTS       4
#define OPT_NO_POLL        5
#define OPT_DEBUG          6
#define OPT_ORDER          7
#define OPT_NO_RESOLV      8
#define OPT_EXPAND         9
#define OPT_LOCALMX        10
#define OPT_NO_NEG         11
#define OPT_NODOTS_LOCAL   12
#define OPT_NOWILD         13
#define OPT_ETHERS         14
#define OPT_RESOLV_DOMAIN  15
#define OPT_NO_FORK        16
#define OPT_AUTHORITATIVE  17
#define OPT_LOCALISE       18
#define OPT_DBUS           19
#define OPT_DHCP_FQDN      20
#define OPT_NO_PING        21
#define OPT_LEASE_RO       22
#define OPT_ALL_SERVERS    23
#define OPT_RELOAD         24
#define OPT_LOCAL_REBIND   25  
#define OPT_TFTP_SECURE    26
#define OPT_TFTP_NOBLOCK   27
#define OPT_LOG_OPTS       28
#define OPT_TFTP_APREF_IP  29
#define OPT_NO_OVERRIDE    30
#define OPT_NO_REBIND      31
#define OPT_ADD_MAC        32
#define OPT_DNSSEC_PROXY   33
#define OPT_CONSEC_ADDR    34
#define OPT_CONNTRACK      35
#define OPT_FQDN_UPDATE    36
#define OPT_RA             37
#define OPT_TFTP_LC        38
#define OPT_CLEVERBIND     39
#define OPT_TFTP           40
#define OPT_CLIENT_SUBNET  41
#define OPT_QUIET_DHCP     42
#define OPT_QUIET_DHCP6    43
#define OPT_QUIET_RA	   44
#define OPT_DNSSEC_VALID   45
#define OPT_DNSSEC_TIME    46
#define OPT_DNSSEC_DEBUG   47
#define OPT_DNSSEC_IGN_NS  48 
#define OPT_LOCAL_SERVICE  49
#define OPT_LOOP_DETECT    50
#define OPT_EXTRALOG       51
#define OPT_TFTP_NO_FAIL   52
#define OPT_SCRIPT_ARP     53
#define OPT_MAC_B64        54
#define OPT_MAC_HEX        55
#define OPT_TFTP_APREF_MAC 56
#define OPT_RAPID_COMMIT   57
#define OPT_UBUS           58
#define OPT_IGNORE_CLID    59
#define OPT_SINGLE_PORT    60
#define OPT_LEASE_RENEW    61
#define OPT_LOG_DEBUG      62
#define OPT_UMBRELLA       63
#define OPT_UMBRELLA_DEVID 64
#define OPT_CMARK_ALST_EN  65
#define OPT_QUIET_TFTP     66
#define OPT_STRIP_ECS      67
#define OPT_STRIP_MAC      68
#define OPT_NORR           69
#define OPT_NO_IDENT       70
#define OPT_CACHE_RR       71
#define OPT_LOCALHOST_SERVICE  72
#define OPT_LAST           73

#define OPTION_BITS (sizeof(unsigned int)*8)
#define OPTION_SIZE ( (OPT_LAST/OPTION_BITS)+((OPT_LAST%OPTION_BITS)!=0) )
#define option_var(x) (daemon->options[(x) / OPTION_BITS])
#define option_val(x) ((1u) << ((x) % OPTION_BITS))
#define option_bool(x) (option_var(x) & option_val(x))

/* extra flags for my_syslog, we use facilities since they are known 
   not to occupy the same bits as priorities, no matter how syslog.h is set up. 
   MS_DEBUG messages are suppressed unless --log-debug is set. */
#define MS_TFTP   LOG_USER
#define MS_DHCP   LOG_DAEMON
#define MS_SCRIPT LOG_MAIL
#define MS_DEBUG  LOG_NEWS

/* Note that this is used widely as a container for IPv4/IPv6 addresses,
   so for that reason, was well as to avoid wasting memory in almost every
   cache entry, the other variants should not be larger than
   sizeof(struct in6_addr) - 16 bytes.
*/
union all_addr {
  struct in_addr addr4;
  struct in6_addr addr6;
  struct {
    union {
      struct crec *cache;
      char *name;
    } target;
    unsigned int uid;
    int is_name_ptr;  /* disciminates target union */
  } cname;
  struct {
    struct blockdata *keydata;
    unsigned short keylen, flags, keytag;
    unsigned char algo;
  } key; 
  struct {
    struct blockdata *keydata;
    unsigned short keylen, keytag;
    unsigned char algo;
    unsigned char digest; 
  } ds;
  /* for log_query */
  struct {
    unsigned short keytag, algo, digest, rcode;
    int ede;
  } log;
  /* for arbitrary RR record stored in block */
  struct {
    unsigned short rrtype;
    unsigned short datalen; 
    struct blockdata *rrdata;
  } rrblock;
  /* for arbitrary RR record small enough to go in addr.
     NOTE: rrblock and rrdata are discriminated by the F_KEYTAG bit
     in the cache flags. */
  struct datablock {
    unsigned short rrtype;
    unsigned char datalen; /* also length of SOA in negative records. */
    char data[];
  } rrdata;
};

#define RR_IMDATALEN (sizeof(union all_addr) - offsetof(struct datablock, data))

struct bogus_addr {
  int is6, prefix;
  union all_addr addr;
  struct bogus_addr *next;
};

/* dns doctor param */
struct doctor {
  struct in_addr in, end, out, mask;
  struct doctor *next;
};

struct mx_srv_record {
  char *name, *target;
  int issrv, srvport, priority, weight;
  unsigned int offset;
  struct mx_srv_record *next;
};

struct naptr {
  char *name, *replace, *regexp, *services, *flags;
  unsigned int order, pref;
  struct naptr *next;
};

#ifndef NO_ID
#define TXT_STAT_CACHESIZE     1
#define TXT_STAT_INSERTS       2
#define TXT_STAT_EVICTIONS     3
#define TXT_STAT_MISSES        4
#define TXT_STAT_HITS          5
#define TXT_STAT_AUTH          6
#define TXT_STAT_SERVERS       7
#endif

struct txt_record {
  char *name;
  unsigned char *txt;
  unsigned short class, len;
  int stat;
  struct txt_record *next;
};

struct ptr_record {
  char *name, *ptr;
  struct ptr_record *next;
};

struct cname {
  int ttl, flag;
  char *alias, *target;
  struct cname *next, *targetp;
}; 

struct ds_config {
  char *name, *digest;
  int digestlen, class, algo, keytag, digest_type;
  struct ds_config *next;
};

#define ADDRLIST_LITERAL  1
#define ADDRLIST_IPV6     2
#define ADDRLIST_REVONLY  4
#define ADDRLIST_PREFIX   8
#define ADDRLIST_WILDCARD 16
#define ADDRLIST_DECLINED 32

struct addrlist {
  union all_addr addr;
  int flags, prefixlen;
  time_t decline_time;
  struct addrlist *next;
};

#define AUTH6     1
#define AUTH4     2

struct auth_zone {
  char *domain;
  struct auth_name_list {
    char *name;
    int flags;
    struct auth_name_list *next;
  } *interface_names;
  struct addrlist *subnet;
  struct addrlist *exclude;
  struct auth_zone *next;
};

#define HR_6 1
#define HR_4 2

struct host_record {
  int ttl, flags;
  struct name_list {
    char *name;
    struct name_list *next;
  } *names;
  struct in_addr addr;
  struct in6_addr addr6;
  struct host_record *next;
};

#define IN4  1
#define IN6  2
#define INP4 4
#define INP6 8

struct interface_name {
  char *name; /* domain name */
  char *intr; /* interface name */
  int flags;
  struct in_addr proto4;
  struct in6_addr proto6;
  struct addrlist *addr;
  struct interface_name *next;
};

union bigname {
  char name[MAXDNAME];
  union bigname *next; /* freelist */
};

struct blockdata {
  struct blockdata *next;
  unsigned char key[KEYBLOCK_LEN];
};

struct crec { 
  struct crec *next, *prev, *hash_next;
  union all_addr addr;
  time_t ttd; /* time to die */
  /* used as class if DNSKEY/DS, index to source for F_HOSTS */
  unsigned int uid; 
  unsigned int flags;
  union {
    char sname[SMALLDNAME];
    union bigname *bname;
    char *namep;
  } name;
};

#define SIZEOF_BARE_CREC (sizeof(struct crec) - SMALLDNAME)
#define SIZEOF_POINTER_CREC (sizeof(struct crec) + sizeof(char *) - SMALLDNAME)

#define F_IMMORTAL  (1u<<0)
#define F_NAMEP     (1u<<1)
#define F_REVERSE   (1u<<2)
#define F_FORWARD   (1u<<3)
#define F_DHCP      (1u<<4)
#define F_NEG       (1u<<5)       
#define F_HOSTS     (1u<<6)
#define F_IPV4      (1u<<7)
#define F_IPV6      (1u<<8)
#define F_BIGNAME   (1u<<9)
#define F_NXDOMAIN  (1u<<10)
#define F_CNAME     (1u<<11)
#define F_DNSKEY    (1u<<12)
#define F_CONFIG    (1u<<13)
#define F_DS        (1u<<14)
#define F_DNSSECOK  (1u<<15)
#define F_UPSTREAM  (1u<<16)
#define F_RRNAME    (1u<<17)
#define F_SERVER    (1u<<18)
#define F_QUERY     (1u<<19)
#define F_NOERR     (1u<<20)
#define F_AUTH      (1u<<21)
#define F_DNSSEC    (1u<<22)
#define F_KEYTAG    (1u<<23)
#define F_SECSTAT   (1u<<24)
#define F_NO_RR     (1u<<25)
#define F_IPSET     (1u<<26)
#define F_NOEXTRA   (1u<<27)
#define F_DOMAINSRV (1u<<28)
#define F_RCODE     (1u<<29)
#define F_RR        (1u<<30)
#define F_STALE     (1u<<31)

#define UID_NONE      0
/* Values of uid in crecs with F_CONFIG bit set. */
#define SRC_CONFIG    1
#define SRC_HOSTS     2
#define SRC_AH        3


/* struct sockaddr is not large enough to hold any address,
   and specifically not big enough to hold an IPv6 address.
   Blech. Roll our own. */
union mysockaddr {
  struct sockaddr sa;
  struct sockaddr_in in;
  struct sockaddr_in6 in6;
};

/* bits in flag param to IPv6 callbacks from iface_enumerate() */
#define IFACE_TENTATIVE   1
#define IFACE_DEPRECATED  2
#define IFACE_PERMANENT   4


/* The actual values here matter, since we sort on them to get records in the order
   IPv6 addr, IPv4 addr, all zero return, resolvconf servers, upstream server, no-data return  */
#define SERV_LITERAL_ADDRESS    1  /* addr is the answer, or NoDATA is the answer, depending on the next four flags */
#define SERV_USE_RESOLV         2  /* forward this domain in the normal way */
#define SERV_ALL_ZEROS          4  /* return all zeros for A and AAAA */
#define SERV_4ADDR              8  /* addr is IPv4 */
#define SERV_6ADDR             16  /* addr is IPv6 */
#define SERV_HAS_SOURCE        32  /* source address defined */
#define SERV_FOR_NODOTS        64  /* server for names with no domain part only */
#define SERV_WARNED_RECURSIVE 128  /* avoid warning spam */
#define SERV_FROM_DBUS        256  /* 1 if source is DBus */
#define SERV_MARK             512  /* for mark-and-delete and log code */
#define SERV_WILDCARD        1024  /* domain has leading '*' */ 
#define SERV_FROM_RESOLV     2048  /* 1 for servers from resolv, 0 for command line. */
#define SERV_FROM_FILE       4096  /* read from --servers-file */
#define SERV_LOOP            8192  /* server causes forwarding loop */
#define SERV_DO_DNSSEC      16384  /* Validate DNSSEC when using this server */
#define SERV_GOT_TCP        32768  /* Got some data from the TCP connection */

struct serverfd {
  int fd;
  union mysockaddr source_addr;
  char interface[IF_NAMESIZE+1];
  unsigned int ifindex, used, preallocated;
  struct serverfd *next;
};

struct randfd {
  struct server *serv;
  int fd;
  unsigned short refcount; /* refcount == 0xffff means overflow record. */
};

struct randfd_list {
  struct randfd *rfd;
  struct randfd_list *next;
};


struct server {
  u16 flags, domain_len;
  char *domain;
  struct server *next;
  int serial, arrayposn;
  int last_server;
  union mysockaddr addr, source_addr;
  char interface[IF_NAMESIZE+1];
  unsigned int ifindex; /* corresponding to interface, above */
  struct serverfd *sfd; 
  int tcpfd, edns_pktsz;
  time_t pktsz_reduced;
  unsigned int queries, failed_queries, nxdomain_replies, retrys;
  unsigned int query_latency, mma_latency;
  time_t forwardtime;
  int forwardcount;
#ifdef HAVE_LOOP
  u32 uid;
#endif
};

/* First four fields must match struct server in next three definitions.. */
struct serv_addr4 {
  u16 flags, domain_len;
  char *domain;
  struct server *next;
  struct in_addr addr;
};

struct serv_addr6 {
  u16 flags, domain_len;
  char *domain;
  struct server *next;
  struct in6_addr addr;
};

struct serv_local {
  u16 flags, domain_len;
  char *domain;
  struct server *next;
};

struct rebind_domain {
  char *domain;
  struct rebind_domain *next;
};

struct ipsets {
  char **sets;
  char *domain;
  struct ipsets *next;
};

struct allowlist {
  u32 mark, mask;
  char **patterns;
  struct allowlist *next;
};

struct irec {
  union mysockaddr addr;
  struct in_addr netmask; /* only valid for IPv4 */
  int tftp_ok, dhcp4_ok, dhcp6_ok, mtu, done, warned, dad;
  int dns_auth, index, multicast_done, found, label;
  char *name; 
  struct irec *next;
};

struct listener {
  int fd, tcpfd, tftpfd, used;
  union mysockaddr addr;
  struct irec *iface; /* only sometimes valid for non-wildcard */
  struct listener *next;
};

/* interface and address parms from command line. */
struct iname {
  char *name;
  union mysockaddr addr;
  int flags;
  struct iname *next;
};

#define  INAME_USED  1
#define  INAME_4     2
#define  INAME_6     4

struct rrlist {
  unsigned short rr;
  struct rrlist *next;
};

/* subnet parameters from command line */
struct mysubnet {
  union mysockaddr addr;
  int addr_used;
  int mask;
};

/* resolv-file parms from command-line */
struct resolvc {
  struct resolvc *next;
  int is_default, logged;
  time_t mtime;
  ino_t ino;
  char *name;
#ifdef HAVE_INOTIFY
  int wd; /* inotify watch descriptor */
  char *file; /* pointer to file part if path */
#endif
};

/* adn-hosts parms from command-line (also dhcp-hostsfile and dhcp-optsfile and dhcp-hostsdir*/
#define AH_DIR      1
#define AH_INACTIVE 2
#define AH_WD_DONE  4
#define AH_HOSTS    8
#define AH_DHCP_HST 16
#define AH_DHCP_OPT 32
struct hostsfile {
  struct hostsfile *next;
  int flags;
  char *fname;
  unsigned int index; /* matches to cache entries for logging */
};

struct dyndir {
  struct dyndir *next;
  struct hostsfile *files;
  int flags;
  char *dname;
#ifdef HAVE_INOTIFY
  int wd; /* inotify watch descriptor */
#endif
};

/* packet-dump flags */
#define DUMP_QUERY         0x0001
#define DUMP_REPLY         0x0002
#define DUMP_UP_QUERY      0x0004 
#define DUMP_UP_REPLY      0x0008
#define DUMP_SEC_QUERY     0x0010
#define DUMP_SEC_REPLY     0x0020
#define DUMP_BOGUS         0x0040 
#define DUMP_SEC_BOGUS     0x0080
#define DUMP_DHCP          0x1000
#define DUMP_DHCPV6        0x2000
#define DUMP_RA            0x4000
#define DUMP_TFTP          0x8000

/* DNSSEC status values. */
#define STAT_SECURE             0x10000
#define STAT_INSECURE           0x20000
#define STAT_BOGUS              0x30000
#define STAT_NEED_DS            0x40000
#define STAT_NEED_KEY           0x50000
#define STAT_TRUNCATED          0x60000
#define STAT_SECURE_WILDCARD    0x70000
#define STAT_OK                 0x80000
#define STAT_ABANDONED          0x90000

#define DNSSEC_FAIL_NYV         0x0001 /* key not yet valid */
#define DNSSEC_FAIL_EXP         0x0002 /* key expired */
#define DNSSEC_FAIL_INDET       0x0004 /* indetermined */
#define DNSSEC_FAIL_NOKEYSUP    0x0008 /* no supported key algo. */
#define DNSSEC_FAIL_NOSIG       0x0010 /* No RRsigs */
#define DNSSEC_FAIL_NOZONE      0x0020 /* No Zone bit set */
#define DNSSEC_FAIL_NONSEC      0x0040 /* No NSEC */
#define DNSSEC_FAIL_NODSSUP     0x0080 /* no supported DS algo. */
#define DNSSEC_FAIL_NOKEY       0x0100 /* no DNSKEY */
#define DNSSEC_FAIL_NSEC3_ITERS 0x0200 /* too many iterations in NSEC3 */
#define DNSSEC_FAIL_BADPACKET   0x0400 /* bad packet */
#define DNSSEC_FAIL_WORK        0x0800 /* too much crypto */

#define STAT_ISEQUAL(a, b)  (((a) & 0xffff0000) == (b))

#define FREC_NOREBIND           1
#define FREC_CHECKING_DISABLED  2
#define FREC_NO_CACHE           4
#define FREC_DNSKEY_QUERY       8
#define FREC_DS_QUERY          16
#define FREC_AD_QUESTION       32
#define FREC_DO_QUESTION       64
#define FREC_ADDED_PHEADER    128
#define FREC_TEST_PKTSZ       256
#define FREC_HAS_EXTRADATA    512
#define FREC_HAS_PHEADER     1024

#define HASH_SIZE 32 /* SHA-256 digest size */

struct frec {
  struct frec_src {
    union mysockaddr source;
    union all_addr dest;
    unsigned int iface, log_id;
    int fd;
    unsigned short orig_id;
    struct frec_src *next;
  } frec_src;
  struct server *sentto; /* NULL means free */
  struct randfd_list *rfds;
  unsigned short new_id;
  int forwardall, flags;
  time_t time;
  u32 forward_timestamp;
  int forward_delay;
  unsigned char *hash[HASH_SIZE];
  struct blockdata *stash; /* Saved reply, whilst we validate */
  size_t stash_len;
#ifdef HAVE_DNSSEC 
  int class, work_counter, validate_counter;
  struct frec *dependent; /* Query awaiting internally-generated DNSKEY or DS query */
  struct frec *next_dependent; /* list of above. */
  struct frec *blocking_query; /* Query which is blocking us. */
#endif
  struct frec *next;
};

/* flags in top of length field for DHCP-option tables */
#define OT_ADDR_LIST    0x8000
#define OT_RFC1035_NAME 0x4000
#define OT_INTERNAL     0x2000
#define OT_NAME         0x1000
#define OT_CSTRING      0x0800
#define OT_DEC          0x0400 
#define OT_TIME         0x0200

/* actions in the daemon->helper RPC */
#define ACTION_DEL           1
#define ACTION_OLD_HOSTNAME  2
#define ACTION_OLD           3
#define ACTION_ADD           4
#define ACTION_TFTP          5
#define ACTION_ARP           6
#define ACTION_ARP_DEL       7
#define ACTION_RELAY_SNOOP   8

#define LEASE_NEW            1  /* newly created */
#define LEASE_CHANGED        2  /* modified */
#define LEASE_AUX_CHANGED    4  /* CLID or expiry changed */
#define LEASE_AUTH_NAME      8  /* hostname came from config, not from client */
#define LEASE_USED          16  /* used this DHCPv6 transaction */
#define LEASE_NA            32  /* IPv6 no-temporary lease */
#define LEASE_TA            64  /* IPv6 temporary lease */
#define LEASE_HAVE_HWADDR  128  /* Have set hwaddress */
#define LEASE_EXP_CHANGED  256  /* Lease expiry time changed */

#define LIMIT_SIG_FAIL    0
#define LIMIT_CRYPTO      1
#define LIMIT_WORK        2
#define LIMIT_NSEC3_ITERS 3
#define LIMIT_MAX         4

struct dhcp_lease {
  int clid_len;          /* length of client identifier */
  unsigned char *clid;   /* clientid */
  char *hostname, *fqdn; /* name from client-hostname option or config */
  char *old_hostname;    /* hostname before it moved to another lease */
  int flags;
  time_t expires;        /* lease expiry */
#ifdef HAVE_BROKEN_RTC
  unsigned int length;
#endif
  int hwaddr_len, hwaddr_type;
  unsigned char hwaddr[DHCP_CHADDR_MAX]; 
  struct in_addr addr, override, giaddr;
  unsigned char *extradata;
  unsigned int extradata_len, extradata_size;
  int last_interface;
  int new_interface;     /* save possible originated interface */
  int new_prefixlen;     /* and its prefix length */
#ifdef HAVE_DHCP6
  struct in6_addr addr6;
  unsigned int iaid;
  struct slaac_address {
    struct in6_addr addr;
    time_t ping_time;
    int backoff; /* zero -> confirmed */
    struct slaac_address *next;
  } *slaac_address;
  int vendorclass_count;
#endif
  struct dhcp_lease *next;
};

struct dhcp_netid {
  char *net;
  struct dhcp_netid *next;
};

struct dhcp_netid_list {
  struct dhcp_netid *list;
  struct dhcp_netid_list *next;
};

struct tag_if {
  struct dhcp_netid_list *set;
  struct dhcp_netid *tag;
  struct tag_if *next;
};

struct delay_config {
  int delay;
  struct dhcp_netid *netid;
  struct delay_config *next;
};

struct hwaddr_config {
  int hwaddr_len, hwaddr_type;
  unsigned char hwaddr[DHCP_CHADDR_MAX];
  unsigned int wildcard_mask;
  struct hwaddr_config *next;
};

struct dhcp_config {
  unsigned int flags;
  int clid_len;          /* length of client identifier */
  unsigned char *clid;   /* clientid */
  char *hostname, *domain;
  struct dhcp_netid_list *netid;
  struct dhcp_netid *filter;
#ifdef HAVE_DHCP6
  struct addrlist *addr6;
#endif
  struct in_addr addr;
  time_t decline_time;
  unsigned int lease_time;
  struct hwaddr_config *hwaddr;
  struct dhcp_config *next;
};

#define have_config(config, mask) ((config) && ((config)->flags & (mask))) 

#define CONFIG_DISABLE           1
#define CONFIG_CLID              2
#define CONFIG_TIME              8
#define CONFIG_NAME             16
#define CONFIG_ADDR             32
#define CONFIG_NOCLID          128
#define CONFIG_FROM_ETHERS     256    /* entry created by /etc/ethers */
#define CONFIG_ADDR_HOSTS      512    /* address added by from /etc/hosts */
#define CONFIG_DECLINED       1024    /* address declined by client */
#define CONFIG_BANK           2048    /* from dhcp hosts file */
#define CONFIG_ADDR6          4096
#define CONFIG_ADDR6_HOSTS   16384    /* address added by from /etc/hosts */

struct dhcp_opt {
  int opt, len, flags;
  union {
    int encap;
    unsigned int wildcard_mask;
    unsigned char *vendor_class;
  } u;
  unsigned char *val;
  struct dhcp_netid *netid;
  struct dhcp_opt *next;
};

#define DHOPT_ADDR               1
#define DHOPT_STRING             2
#define DHOPT_ENCAPSULATE        4
#define DHOPT_ENCAP_MATCH        8
#define DHOPT_FORCE             16
#define DHOPT_BANK              32
#define DHOPT_ENCAP_DONE        64
#define DHOPT_MATCH            128
#define DHOPT_VENDOR           256
#define DHOPT_HEX              512
#define DHOPT_VENDOR_MATCH    1024
#define DHOPT_RFC3925         2048
#define DHOPT_TAGOK           4096
#define DHOPT_ADDR6           8192
#define DHOPT_VENDOR_PXE     16384

struct dhcp_boot {
  char *file, *sname, *tftp_sname;
  struct in_addr next_server;
  struct dhcp_netid *netid;
  struct dhcp_boot *next;
};

struct dhcp_match_name {
  char *name;
  int wildcard;
  struct dhcp_netid *netid;
  struct dhcp_match_name *next;
};

struct pxe_service {
  unsigned short CSA, type; 
  char *menu, *basename, *sname;
  struct in_addr server;
  struct dhcp_netid *netid;
  struct pxe_service *next;
};

#define DHCP_PXE_DEF_VENDOR      "PXEClient"

#define MATCH_VENDOR     1
#define MATCH_USER       2
#define MATCH_CIRCUIT    3
#define MATCH_REMOTE     4
#define MATCH_SUBSCRIBER 5

/* vendorclass, userclass, remote-id or circuit-id */
struct dhcp_vendor {
  int len, match_type;
  unsigned int enterprise;
  char *data;
  struct dhcp_netid netid;
  struct dhcp_vendor *next;
};

struct dhcp_pxe_vendor {
  char *data;
  struct dhcp_pxe_vendor *next;
};

struct dhcp_mac {
  unsigned int mask;
  int hwaddr_len, hwaddr_type;
  unsigned char hwaddr[DHCP_CHADDR_MAX];
  struct dhcp_netid netid;
  struct dhcp_mac *next;
};

struct dhcp_bridge {
  char iface[IF_NAMESIZE];
  struct dhcp_bridge *alias, *next;
};

struct cond_domain {
  char *domain, *prefix; /* prefix is text-prefix on domain name */
  char *interface;       /* These two set when domain comes from interface. */
  struct addrlist *al;
  struct in_addr start, end;
  struct in6_addr start6, end6;
  int is6, indexed, prefixlen;
  struct cond_domain *next;
}; 

struct ra_interface {
  char *name;
  char *mtu_name;
  int interval, lifetime, prio, mtu;
  struct ra_interface *next;
};

struct dhcp_context {
  unsigned int lease_time, addr_epoch;
  struct in_addr netmask, broadcast;
  struct in_addr local, router;
  struct in_addr start, end; /* range of available addresses */
#ifdef HAVE_DHCP6
  struct in6_addr start6, end6; /* range of available addresses */
  struct in6_addr local6;
  int prefix, if_index;
  unsigned int valid, preferred, saved_valid;
  time_t ra_time, ra_short_period_start, address_lost_time;
  char *template_interface;
#endif
  int flags;
  struct dhcp_netid netid, *filter;
  struct dhcp_context *next, *current;
};

struct shared_network {
  int if_index;
  struct in_addr match_addr, shared_addr;
#ifdef HAVE_DHCP6
  /* shared_addr == 0 for IP6 entries. */
  struct in6_addr match_addr6, shared_addr6;
#endif
  struct shared_network *next;
};

#define CONTEXT_STATIC         (1u<<0)
#define CONTEXT_NETMASK        (1u<<1)
#define CONTEXT_BRDCAST        (1u<<2)
#define CONTEXT_PROXY          (1u<<3)
#define CONTEXT_RA_ROUTER      (1u<<4)
#define CONTEXT_RA_DONE        (1u<<5)
#define CONTEXT_RA_NAME        (1u<<6)
#define CONTEXT_RA_STATELESS   (1u<<7)
#define CONTEXT_DHCP           (1u<<8)
#define CONTEXT_DEPRECATE      (1u<<9)
#define CONTEXT_TEMPLATE       (1u<<10)    /* create contexts using addresses */
#define CONTEXT_CONSTRUCTED    (1u<<11)
#define CONTEXT_GC             (1u<<12)
#define CONTEXT_RA             (1u<<13)
#define CONTEXT_CONF_USED      (1u<<14)
#define CONTEXT_USED           (1u<<15)
#define CONTEXT_OLD            (1u<<16)
#define CONTEXT_V6             (1u<<17)
#define CONTEXT_RA_OFF_LINK    (1u<<18)
#define CONTEXT_SETLEASE       (1u<<19)

struct ping_result {
  struct in_addr addr;
  time_t time;
  unsigned int hash;
  struct ping_result *next;
};

struct tftp_file {
  int refcount, fd;
  off_t size;
  dev_t dev;
  ino_t inode;
  char filename[];
};

struct tftp_transfer {
  int sockfd;
  time_t timeout;
  int backoff;
  unsigned int block, blocksize, expansion;
  off_t offset;
  union mysockaddr peer;
  union all_addr source;
  int if_index;
  char opt_blocksize, opt_transize, netascii, carrylf;
  struct tftp_file *file;
  struct tftp_transfer *next;
};

struct addr_list {
  struct in_addr addr;
  struct addr_list *next;
};

struct tftp_prefix {
  char *interface;
  char *prefix;
  int missing;
  struct tftp_prefix *next;
};

struct dhcp_relay {
  union all_addr local, server;
  char *interface; /* Allowable interface for replies from server, and dest for IPv6 multicast */
  int iface_index; /* working - interface in which requests arrived, for return */
  int port;        /* Port of relay we forward to. */
#ifdef HAVE_SCRIPT
  struct snoop_record {
    struct in6_addr client, prefix;
    int prefix_len;
    struct snoop_record *next;
  } *snoop_records;
#endif
  struct dhcp_relay *next;
};

extern struct daemon {
  /* datastuctures representing the command-line and 
     config file arguments. All set (including defaults)
     in option.c */

  unsigned int options[OPTION_SIZE];
  struct resolvc default_resolv, *resolv_files;
  time_t last_resolv;
  char *servers_file;
  struct mx_srv_record *mxnames;
  struct naptr *naptr;
  struct txt_record *txt, *rr;
  struct ptr_record *ptr;
  struct rrlist *cache_rr, *filter_rr;
  struct host_record *host_records, *host_records_tail;
  struct cname *cnames;
  struct auth_zone *auth_zones;
  struct interface_name *int_names;
  char *mxtarget;
  struct mysubnet *add_subnet4;
  struct mysubnet *add_subnet6;
  char *lease_file;
  char *username, *groupname, *scriptuser;
  char *luascript;
  char *authserver, *hostmaster;
  struct iname *authinterface;
  struct name_list *secondary_forward_server;
  int group_set, osport;
  char *domain_suffix;
  struct cond_domain *cond_domain, *synth_domains;
  char *runfile; 
  char *lease_change_command;
  struct iname *if_names, *if_addrs, *if_except, *dhcp_except, *auth_peers, *tftp_interfaces;
  struct bogus_addr *bogus_addr, *ignore_addr;
  struct server *servers, *servers_tail, *local_domains, **serverarray;
  struct rebind_domain *no_rebind;
  int server_has_wildcard;
  int serverarraysz, serverarrayhwm;
  struct ipsets *ipsets, *nftsets;
  u32 allowlist_mask;
  struct allowlist *allowlists;
  int log_fac; /* log facility */
  char *log_file; /* optional log file */
  int max_logs;  /* queue limit */
  int randport_limit; /* Maximum number of source ports for query. */
  int cachesize, ftabsize;
  int port, query_port, min_port, max_port;
  unsigned long local_ttl, neg_ttl, max_ttl, min_cache_ttl, max_cache_ttl, auth_ttl, dhcp_ttl, use_dhcp_ttl;
  char *dns_client_id;
  u32 umbrella_org;
  u32 umbrella_asset;
  u8 umbrella_device[8];
  int host_index;
  struct hostsfile *addn_hosts;
  struct dhcp_context *dhcp, *dhcp6;
  struct ra_interface *ra_interfaces;
  struct dhcp_config *dhcp_conf;
  struct dhcp_opt *dhcp_opts, *dhcp_match, *dhcp_opts6, *dhcp_match6;
  struct dhcp_match_name *dhcp_name_match;
  struct dhcp_pxe_vendor *dhcp_pxe_vendors;
  struct dhcp_vendor *dhcp_vendors;
  struct dhcp_mac *dhcp_macs;
  struct dhcp_boot *boot_config;
  struct pxe_service *pxe_services;
  struct tag_if *tag_if; 
  struct addr_list *override_relays;
  struct dhcp_relay *relay4, *relay6;
  struct delay_config *delay_conf;
  int override;
  int enable_pxe;
  int doing_ra, doing_dhcp6;
  struct dhcp_netid_list *dhcp_ignore, *dhcp_ignore_names, *dhcp_gen_names; 
  struct dhcp_netid_list *force_broadcast, *bootp_dynamic;
  struct hostsfile *dhcp_hosts_file, *dhcp_opts_file;
  struct dyndir *dynamic_dirs;
  int dhcp_max, tftp_max, tftp_mtu;
  int dhcp_server_port, dhcp_client_port;
  int start_tftp_port, end_tftp_port; 
  unsigned int min_leasetime;
  struct doctor *doctors;
  unsigned short edns_pktsz;
  char *tftp_prefix; 
  struct tftp_prefix *if_prefix; /* per-interface TFTP prefixes */
  unsigned int duid_enterprise, duid_config_len;
  unsigned char *duid_config;
  char *dbus_name;
  char *ubus_name;
  char *dump_file;
  int dump_mask;
  unsigned long soa_sn, soa_refresh, soa_retry, soa_expiry;
  u32 metrics[__METRIC_MAX];
  int fast_retry_time, fast_retry_timeout;
  int cache_max_expiry;
#ifdef HAVE_DNSSEC
  struct ds_config *ds;
  char *timestamp_file;
#endif

  /* globally used stuff for DNS */
  char *packet; /* packet buffer */
  int packet_buff_sz; /* size of above */
  char *namebuff; /* MAXDNAME size buffer */
  char *workspacename;
#ifdef HAVE_DNSSEC
  char *keyname; /* MAXDNAME size buffer */
  unsigned long *rr_status; /* ceiling in TTL from DNSSEC or zero for insecure */
  int rr_status_sz;
  int dnssec_no_time_check;
  int back_to_the_future;
  int limit[LIMIT_MAX];
#endif
  struct frec *frec_list;
  struct frec_src *free_frec_src;
  int frec_src_count;
  struct serverfd *sfds;
  struct irec *interfaces;
  struct listener *listeners;
  struct server *srv_save; /* Used for resend on DoD */
  size_t packet_len;       /*      "        "        */
  int    fd_save;          /*      "        "        */
  pid_t *tcp_pids;
  int *tcp_pipes;
  int pipe_to_parent;
  int numrrand;
  struct randfd *randomsocks;
  struct randfd_list *rfl_spare, *rfl_poll;
  int v6pktinfo; 
  struct addrlist *interface_addrs; /* list of all addresses/prefix lengths associated with all local interfaces */
  int log_id, log_display_id; /* ids of transactions for logging */
  union mysockaddr *log_source_addr;

  /* DHCP state */
  int dhcpfd, helperfd, pxefd; 
#ifdef HAVE_INOTIFY
  int inotifyfd;
#endif
#if defined(HAVE_LINUX_NETWORK)
  int netlinkfd, kernel_version;
#elif defined(HAVE_BSD_NETWORK)
  int dhcp_raw_fd, dhcp_icmp_fd, routefd;
#endif
  struct iovec dhcp_packet;
  char *dhcp_buff, *dhcp_buff2, *dhcp_buff3;
  struct ping_result *ping_results;
  FILE *lease_stream;
  struct dhcp_bridge *bridges;
  struct shared_network *shared_networks;
#ifdef HAVE_DHCP6
  int duid_len;
  unsigned char *duid;
  struct iovec outpacket;
  int dhcp6fd, icmp6fd;
#  ifdef HAVE_SCRIPT
  struct snoop_record *free_snoops;
#  endif
#endif
  
  /* DBus stuff */
  /* void * here to avoid depending on dbus headers outside dbus.c */
  void *dbus;
#ifdef HAVE_DBUS
  struct watch *watches;
#endif

  /* UBus stuff */
#ifdef HAVE_UBUS
  /* void * here to avoid depending on ubus headers outside ubus.c */
  void *ubus;
#endif

  /* TFTP stuff */
  struct tftp_transfer *tftp_trans, *tftp_done_trans;

  /* utility string buffer, hold max sized IP address as string */
  char *addrbuff;
  char *addrbuff2; /* only allocated when OPT_EXTRALOG */

#ifdef HAVE_DUMPFILE
  /* file for packet dumps. */
  int dumpfd;
#endif
  int max_procs;
  uint max_procs_used;
} *daemon;

struct server_details {
  union mysockaddr *addr, *source_addr;
  struct addrinfo *hostinfo, *orig_hostinfo;
  char *interface, *source, *scope_id, *interface_opt;
  int serv_port, source_port, addr_type, scope_index, valid;
  u16 *flags;
};

/* cache.c */
void cache_init(void);
unsigned short rrtype(char *in);
void next_uid(struct crec *crecp);
void log_query(unsigned int flags, char *name, union all_addr *addr, char *arg, unsigned short type); 
char *record_source(unsigned int index);
int cache_find_non_terminal(char *name, time_t now);
struct crec *cache_find_by_addr(struct crec *crecp,
				union all_addr *addr, time_t now, 
				unsigned int prot);
struct crec *cache_find_by_name(struct crec *crecp, 
				char *name, time_t now, unsigned int prot);
void cache_end_insert(void);
void cache_start_insert(void);
unsigned int cache_remove_uid(const unsigned int uid);
int cache_recv_insert(time_t now, int fd);
struct crec *cache_insert(char *name, union all_addr *addr, unsigned short class, 
			  time_t now, unsigned long ttl, unsigned int flags);
void cache_reload(void);
void cache_add_dhcp_entry(char *host_name, int prot, union all_addr *host_address, time_t ttd);
struct in_addr a_record_from_hosts(char *name, time_t now);
void cache_unhash_dhcp(void);
void dump_cache(time_t now);
#ifndef NO_ID
int cache_make_stat(struct txt_record *t);
#endif
char *cache_get_name(struct crec *crecp);
char *cache_get_cname_target(struct crec *crecp);
struct crec *cache_enumerate(int init);
int read_hostsfile(char *filename, unsigned int index, int cache_size, 
		   struct crec **rhash, int hashsz);

/* blockdata.c */
void blockdata_init(void);
void blockdata_report(void);
struct blockdata *blockdata_alloc(char *data, size_t len);
int blockdata_expand(struct blockdata *block, size_t oldlen,
		     char *data, size_t newlen);
void *blockdata_retrieve(struct blockdata *block, size_t len, void *data);
struct blockdata *blockdata_read(int fd, size_t len);
void blockdata_write(struct blockdata *block, size_t len, int fd);
void blockdata_free(struct blockdata *blocks);

/* domain.c */
char *get_domain(struct in_addr addr);
char *get_domain6(struct in6_addr *addr);
int is_name_synthetic(int flags, char *name, union all_addr *addr);
int is_rev_synth(int flag, union all_addr *addr, char *name);

/* rfc1035.c */
int do_doctor(struct dns_header *header, size_t qlen, char *namebuff);
int extract_name(struct dns_header *header, size_t plen, unsigned char **pp, 
                 char *name, int isExtract, int extrabytes);
unsigned char *skip_name(unsigned char *ansp, struct dns_header *header, size_t plen, int extrabytes);
unsigned char *skip_questions(struct dns_header *header, size_t plen);
unsigned char *skip_section(unsigned char *ansp, int count, struct dns_header *header, size_t plen);
unsigned int extract_request(struct dns_header *header, size_t qlen, 
			       char *name, unsigned short *typep);
void setup_reply(struct dns_header *header, unsigned int flags, int ede);
int extract_addresses(struct dns_header *header, size_t qlen, char *name,
		      time_t now, struct ipsets *ipsets, struct ipsets *nftsets, int is_sign,
                      int check_rebind, int no_cache_dnssec, int secure);
#if defined(HAVE_CONNTRACK) && defined(HAVE_UBUS)
void report_addresses(struct dns_header *header, size_t len, u32 mark);
#endif
size_t answer_request(struct dns_header *header, char *limit, size_t qlen,  
		      struct in_addr local_addr, struct in_addr local_netmask, 
		      time_t now, int ad_reqd, int do_bit, int have_pseudoheader,
		      int *stale, int *filtered);
int check_for_bogus_wildcard(struct dns_header *header, size_t qlen, char *name, 
			     time_t now);
int check_for_ignored_address(struct dns_header *header, size_t qlen);
int check_for_local_domain(char *name, time_t now);
size_t resize_packet(struct dns_header *header, size_t plen, 
		  unsigned char *pheader, size_t hlen);
int add_resource_record(struct dns_header *header, char *limit, int *truncp,
			int nameoffset, unsigned char **pp, unsigned long ttl, 
			int *offset, unsigned short type, unsigned short class, char *format, ...);
int in_arpa_name_2_addr(char *namein, union all_addr *addrp);
int private_net(struct in_addr addr, int ban_localhost);

/* auth.c */
#ifdef HAVE_AUTH
size_t answer_auth(struct dns_header *header, char *limit, size_t qlen, 
		   time_t now, union mysockaddr *peer_addr, int local_query,
		   int do_bit, int have_pseudoheader);
int in_zone(struct auth_zone *zone, char *name, char **cut);
#endif

/* dnssec.c */
#ifdef HAVE_DNSSEC
size_t dnssec_generate_query(struct dns_header *header, unsigned char *end, char *name, int class, int type, int edns_pktsz);
int dnssec_validate_by_ds(time_t now, struct dns_header *header, size_t plen, char *name,
			  char *keyname, int class, int *validate_count);
int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char *name,
		       char *keyname, int class, int *validate_count);
int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int *class,
			  int check_unsigned, int *neganswer, int *nons, int *nsec_ttl, int *validate_count);
int dnskey_keytag(int alg, int flags, unsigned char *key, int keylen);
size_t filter_rrsigs(struct dns_header *header, size_t plen);
int setup_timestamp(void);
int errflags_to_ede(int status);
#endif

/* hash_questions.c */
void hash_questions_init(void);
unsigned char *hash_questions(struct dns_header *header, size_t plen, char *name);

/* crypto.c */
const struct nettle_hash *hash_find(char *name);
int hash_init(const struct nettle_hash *hash, void **ctxp, unsigned char **digestp);
int verify(struct blockdata *key_data, unsigned int key_len, unsigned char *sig, size_t sig_len,
	   unsigned char *digest, size_t digest_len, int algo);
char *ds_digest_name(int digest);
char *algo_digest_name(int algo);
char *nsec3_digest_name(int digest);

/* util.c */
void rand_init(void);
unsigned short rand16(void);
u32 rand32(void);
u64 rand64(void);
int rr_on_list(struct rrlist *list, unsigned short rr);
int legal_hostname(char *name);
char *canonicalise(char *in, int *nomem);
unsigned char *do_rfc1035_name(unsigned char *p, char *sval, char *limit);
void *safe_malloc(size_t size);
void safe_strncpy(char *dest, const char *src, size_t size);
void safe_pipe(int *fd, int read_noblock);
void *whine_malloc(size_t size);
void *whine_realloc(void *ptr, size_t size);
int sa_len(union mysockaddr *addr);
int sockaddr_isequal(const union mysockaddr *s1, const union mysockaddr *s2);
int sockaddr_isnull(const union mysockaddr *s);
int hostname_order(const char *a, const char *b);
int hostname_isequal(const char *a, const char *b);
int hostname_issubdomain(char *a, char *b);
time_t dnsmasq_time(void);
u32 dnsmasq_milliseconds(void);
int netmask_length(struct in_addr mask);
int is_same_net(struct in_addr a, struct in_addr b, struct in_addr mask);
int is_same_net_prefix(struct in_addr a, struct in_addr b, int prefix);
int is_same_net6(struct in6_addr *a, struct in6_addr *b, int prefixlen);
u64 addr6part(struct in6_addr *addr);
void setaddr6part(struct in6_addr *addr, u64 host);
int retry_send(ssize_t rc);
void prettyprint_time(char *buf, unsigned int t);
int prettyprint_addr(union mysockaddr *addr, char *buf);
int parse_hex(char *in, unsigned char *out, int maxlen, 
	      unsigned int *wildcard_mask, int *mac_type);
int memcmp_masked(unsigned char *a, unsigned char *b, int len, 
		  unsigned int mask);
int expand_buf(struct iovec *iov, size_t size);
char *print_mac(char *buff, unsigned char *mac, int len);
int read_write(int fd, unsigned char *packet, int size, int rw);
void close_fds(long max_fd, int spare1, int spare2, int spare3);
int wildcard_match(const char* wildcard, const char* match);
int wildcard_matchn(const char* wildcard, const char* match, int num);
#ifdef HAVE_LINUX_NETWORK
int kernel_version(void);
#endif

/* log.c */
void die(char *message, char *arg1, int exit_code) ATTRIBUTE_NORETURN;
int log_start(struct passwd *ent_pw, int errfd);
int log_reopen(char *log_file);

void my_syslog(int priority, const char *format, ...);

void set_log_writer(void);
void check_log_writer(int force);
void flush_log(void);

/* option.c */
void read_opts (int argc, char **argv, char *compile_opts);
char *option_string(int prot, unsigned int opt, unsigned char *val, 
		    int opt_len, char *buf, int buf_len);
void reread_dhcp(void);
void read_servers_file(void);
void set_option_bool(unsigned int opt);
void reset_option_bool(unsigned int opt);
struct hostsfile *expand_filelist(struct hostsfile *list);
char *parse_server(char *arg, struct server_details *sdetails);
char *parse_server_addr(struct server_details *sdetails);
int parse_server_next(struct server_details *sdetails);
int option_read_dynfile(char *file, int flags);

/* forward.c */
void reply_query(int fd, time_t now);
void receive_query(struct listener *listen, time_t now);
unsigned char *tcp_request(int confd, time_t now,
			   union mysockaddr *local_addr, struct in_addr netmask, int auth_dns);
void server_gone(struct server *server);
int send_from(int fd, int nowild, char *packet, size_t len, 
	       union mysockaddr *to, union all_addr *source,
	       unsigned int iface);
void resend_query(void);
int allocate_rfd(struct randfd_list **fdlp, struct server *serv);
void free_rfds(struct randfd_list **fdlp);
int fast_retry(time_t now);

/* network.c */
int indextoname(int fd, int index, char *name);
int local_bind(int fd, union mysockaddr *addr, char *intname, unsigned int ifindex, int is_tcp);
void pre_allocate_sfds(void);
int reload_servers(char *fname);
void check_servers(int no_loop_call);
int enumerate_interfaces(int reset);
void create_wildcard_listeners(void);
void create_bound_listeners(int dienow);
void warn_bound_listeners(void);
void warn_wild_labels(void);
void warn_int_names(void);
int is_dad_listeners(void);
int iface_check(int family, union all_addr *addr, char *name, int *auth);
int loopback_exception(int fd, int family, union all_addr *addr, char *name);
int label_exception(int index, int family, union all_addr *addr);
int fix_fd(int fd);
int tcp_interface(int fd, int af);
int set_ipv6pktinfo(int fd);
#ifdef HAVE_DHCP6
void join_multicast(int dienow);
#endif
#if defined(HAVE_LINUX_NETWORK) || defined(HAVE_BSD_NETWORK)
void newaddress(time_t now);
#endif


/* dhcp.c */
#ifdef HAVE_DHCP
void dhcp_init(void);
void dhcp_packet(time_t now, int pxe_fd);
struct dhcp_context *address_available(struct dhcp_context *context, 
				       struct in_addr taddr,
				       struct dhcp_netid *netids);
struct dhcp_context *narrow_context(struct dhcp_context *context, 
				    struct in_addr taddr,
				    struct dhcp_netid *netids);
struct ping_result *do_icmp_ping(time_t now, struct in_addr addr,
				 unsigned int hash, int loopback);
int address_allocate(struct dhcp_context *context,
		     struct in_addr *addrp, unsigned char *hwaddr, int hw_len,
		     struct dhcp_netid *netids, time_t now, int loopback);
void dhcp_read_ethers(void);
struct dhcp_config *config_find_by_address(struct dhcp_config *configs, struct in_addr addr);
char *host_from_dns(struct in_addr addr);
#endif

/* lease.c */
#ifdef HAVE_DHCP
void lease_update_file(time_t now);
void lease_update_dns(int force);
void lease_init(time_t now);
struct dhcp_lease *lease4_allocate(struct in_addr addr);
#ifdef HAVE_DHCP6
struct dhcp_lease *lease6_allocate(struct in6_addr *addrp, int lease_type);
struct dhcp_lease *lease6_find(unsigned char *clid, int clid_len, 
			       int lease_type, unsigned int iaid, struct in6_addr *addr);
void lease6_reset(void);
struct dhcp_lease *lease6_find_by_client(struct dhcp_lease *first, int lease_type,
					 unsigned char *clid, int clid_len, unsigned int iaid);
struct dhcp_lease *lease6_find_by_addr(struct in6_addr *net, int prefix, u64 addr);
u64 lease_find_max_addr6(struct dhcp_context *context);
void lease_ping_reply(struct in6_addr *sender, unsigned char *packet, char *interface);
void lease_update_slaac(time_t now);
void lease_set_iaid(struct dhcp_lease *lease, unsigned int iaid);
void lease_make_duid(time_t now);
#endif
void lease_set_hwaddr(struct dhcp_lease *lease, const unsigned char *hwaddr,
		      const unsigned char *clid, int hw_len, int hw_type,
		      int clid_len, time_t now, int force);
void lease_set_hostname(struct dhcp_lease *lease, const char *name, int auth, char *domain, char *config_domain);
void lease_set_expires(struct dhcp_lease *lease, unsigned int len, time_t now);
void lease_set_interface(struct dhcp_lease *lease, int interface, time_t now);
struct dhcp_lease *lease_find_by_client(unsigned char *hwaddr, int hw_len, int hw_type,  
					unsigned char *clid, int clid_len);
struct dhcp_lease *lease_find_by_addr(struct in_addr addr);
struct in_addr lease_find_max_addr(struct dhcp_context *context);
void lease_prune(struct dhcp_lease *target, time_t now);
void lease_update_from_configs(void);
int do_script_run(time_t now);
void rerun_scripts(void);
void lease_find_interfaces(time_t now);
void lease_calc_fqdns(void);
#ifdef HAVE_SCRIPT
void lease_add_extradata(struct dhcp_lease *lease, unsigned char *data, 
			 unsigned int len, int delim);
#endif
#endif

/* rfc2131.c */
#ifdef HAVE_DHCP
size_t dhcp_reply(struct dhcp_context *context, char *iface_name, int int_index,
		  size_t sz, time_t now, int unicast_dest, int loopback,
		  int *is_inform, int pxe, struct in_addr fallback, time_t recvtime);
unsigned char *extended_hwaddr(int hwtype, int hwlen, unsigned char *hwaddr, 
			       int clid_len, unsigned char *clid, int *len_out);
#endif

/* dnsmasq.c */
#ifdef HAVE_DHCP
int make_icmp_sock(void);
int icmp_ping(struct in_addr addr);
int delay_dhcp(time_t start, int sec, int fd, uint32_t addr, unsigned short id);
#endif
void queue_event(int event);
void send_alarm(time_t event, time_t now);
void send_event(int fd, int event, int data, char *msg);
void clear_cache_and_reload(time_t now);

/* netlink.c */
#ifdef HAVE_LINUX_NETWORK
char *netlink_init(void);
void netlink_multicast(void);
#endif

/* bpf.c */
#ifdef HAVE_BSD_NETWORK
void init_bpf(void);
void send_via_bpf(struct dhcp_packet *mess, size_t len,
		  struct in_addr iface_addr, struct ifreq *ifr);
void route_init(void);
void route_sock(void);
#endif

/* bpf.c or netlink.c */
int iface_enumerate(int family, void *parm, int (callback)());

/* dbus.c */
#ifdef HAVE_DBUS
char *dbus_init(void);
void check_dbus_listeners(void);
void set_dbus_listeners(void);
#  ifdef HAVE_DHCP
void emit_dbus_signal(int action, struct dhcp_lease *lease, char *hostname);
#  endif
#endif

/* ubus.c */
#ifdef HAVE_UBUS
char *ubus_init(void);
void set_ubus_listeners(void);
void check_ubus_listeners(void);
void ubus_event_bcast(const char *type, const char *mac, const char *ip, const char *name, const char *interface);
#  ifdef HAVE_CONNTRACK
void ubus_event_bcast_connmark_allowlist_refused(u32 mark, const char *name);
void ubus_event_bcast_connmark_allowlist_resolved(u32 mark, const char *pattern, const char *ip, u32 ttl);
#  endif
#endif

/* ipset.c */
#ifdef HAVE_IPSET
void ipset_init(void);
int add_to_ipset(const char *setname, const union all_addr *ipaddr, int flags, int remove);
#endif

/* nftset.c */
#ifdef HAVE_NFTSET
void nftset_init(void);
int add_to_nftset(const char *setpath, const union all_addr *ipaddr, int flags, int remove);
#endif

/* pattern.c */
#ifdef HAVE_CONNTRACK
int is_valid_dns_name(const char *value);
int is_valid_dns_name_pattern(const char *value);
int is_dns_name_matching_pattern(const char *name, const char *pattern);
#endif

/* helper.c */
#if defined(HAVE_SCRIPT)
int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd);
void helper_write(void);
void queue_script(int action, struct dhcp_lease *lease, 
		  char *hostname, time_t now);
#ifdef HAVE_TFTP
void queue_tftp(off_t file_len, char *filename, union mysockaddr *peer);
#endif
void queue_arp(int action, unsigned char *mac, int maclen,
	       int family, union all_addr *addr);
int helper_buf_empty(void);
#ifdef HAVE_DHCP6
void queue_relay_snoop(struct in6_addr *client, int if_index, struct in6_addr *prefix, int prefix_len);
#endif
#endif

/* tftp.c */
#ifdef HAVE_TFTP
void tftp_request(struct listener *listen, time_t now);
void check_tftp_listeners(time_t now);
int do_tftp_script_run(void);
#endif

/* conntrack.c */
#ifdef HAVE_CONNTRACK
int get_incoming_mark(union mysockaddr *peer_addr, union all_addr *local_addr,
		      int istcp, unsigned int *markp);
#endif

/* dhcp6.c */
#ifdef HAVE_DHCP6
void dhcp6_init(void);
void dhcp6_packet(time_t now);
struct dhcp_context *address6_allocate(struct dhcp_context *context,  unsigned char *clid, int clid_len, int temp_addr,
				       unsigned int iaid, int serial, struct dhcp_netid *netids, int plain_range, struct in6_addr *ans);
struct dhcp_context *address6_available(struct dhcp_context *context, 
					struct in6_addr *taddr,
					struct dhcp_netid *netids,
					int plain_range);
struct dhcp_context *address6_valid(struct dhcp_context *context, 
				    struct in6_addr *taddr,
				    struct dhcp_netid *netids,
				    int plain_range);
struct dhcp_config *config_find_by_address6(struct dhcp_config *configs, struct in6_addr *net, 
					    int prefix, struct in6_addr *addr);
void make_duid(time_t now);
void dhcp_construct_contexts(time_t now);
void get_client_mac(struct in6_addr *client, int iface, unsigned char *mac, 
		    unsigned int *maclenp, unsigned int *mactypep, time_t now);
#endif
  
/* rfc3315.c */
#ifdef HAVE_DHCP6
unsigned short dhcp6_reply(struct dhcp_context *context, int interface, char *iface_name,  
			   struct in6_addr *fallback, struct in6_addr *ll_addr, struct in6_addr *ula_addr,
			   size_t sz, struct in6_addr *client_addr, time_t now);
int relay_upstream6(int iface_index, ssize_t sz, struct in6_addr *peer_address, 
		     u32 scope_id, time_t now);

int relay_reply6( struct sockaddr_in6 *peer, ssize_t sz, char *arrival_interface);
#  ifdef HAVE_SCRIPT
int do_snoop_script_run(void);
#  endif
#endif

/* dhcp-common.c */
#ifdef HAVE_DHCP
void dhcp_common_init(void);
ssize_t recv_dhcp_packet(int fd, struct msghdr *msg);
struct dhcp_netid *run_tag_if(struct dhcp_netid *tags);
struct dhcp_netid *option_filter(struct dhcp_netid *tags, struct dhcp_netid *context_tags,
				 struct dhcp_opt *opts);
int match_netid(struct dhcp_netid *check, struct dhcp_netid *pool, int tagnotneeded);
char *strip_hostname(char *hostname);
void log_tags(struct dhcp_netid *netid, u32 xid);
int match_bytes(struct dhcp_opt *o, unsigned char *p, int len);
void dhcp_update_configs(struct dhcp_config *configs);
void display_opts(void);
int lookup_dhcp_opt(int prot, char *name);
int lookup_dhcp_len(int prot, int val);
struct dhcp_config *find_config(struct dhcp_config *configs,
				struct dhcp_context *context,
				unsigned char *clid, int clid_len,
				unsigned char *hwaddr, int hw_len, 
				int hw_type, char *hostname,
				struct dhcp_netid *filter);
int config_has_mac(struct dhcp_config *config, unsigned char *hwaddr, int len, int type);
#ifdef HAVE_LINUX_NETWORK
char *whichdevice(void);
int bind_dhcp_devices(char *bound_device);
#endif
#  ifdef HAVE_DHCP6
void display_opts6(void);
#  endif
void log_context(int family, struct dhcp_context *context);
void log_relay(int family, struct dhcp_relay *relay);
#endif

/* outpacket.c */
#ifdef HAVE_DHCP6
void end_opt6(int container);
void reset_counter(void);
int save_counter(int newval);
void *expand(size_t headroom);
int new_opt6(int opt);
void *put_opt6(void *data, size_t len);
void put_opt6_long(unsigned int val);
void put_opt6_short(unsigned int val);
void put_opt6_char(unsigned int val);
void put_opt6_string(char *s);
#endif

/* radv.c */
#ifdef HAVE_DHCP6
void ra_init(time_t now);
void icmp6_packet(time_t now);
time_t periodic_ra(time_t now);
void ra_start_unsolicited(time_t now, struct dhcp_context *context);
#endif

/* slaac.c */ 
#ifdef HAVE_DHCP6
void slaac_add_addrs(struct dhcp_lease *lease, time_t now, int force);
time_t periodic_slaac(time_t now, struct dhcp_lease *leases);
void slaac_ping_reply(struct in6_addr *sender, unsigned char *packet, char *interface, struct dhcp_lease *leases);
#endif

/* loop.c */
#ifdef HAVE_LOOP
void loop_send_probes(void);
int detect_loop(char *query, int type);
#endif

/* inotify.c */
#ifdef HAVE_INOTIFY
void inotify_dnsmasq_init(void);
int inotify_check(time_t now);
void set_dynamic_inotify(int flag, int total_size, struct crec **rhash, int revhashsz);
#endif

/* poll.c */
void poll_reset(void);
int poll_check(int fd, short event);
void poll_listen(int fd, short event);
int do_poll(int timeout);

/* rrfilter.c */
size_t rrfilter(struct dns_header *header, size_t *plen, int mode);
short *rrfilter_desc(int type);
int expand_workspace(unsigned char ***wkspc, int *szp, int new);
int to_wire(char *name);
void from_wire(char *name);
/* modes. */
#define RRFILTER_EDNS0   0
#define RRFILTER_DNSSEC  1
#define RRFILTER_CONF    2

/* edns0.c */
unsigned char *find_pseudoheader(struct dns_header *header, size_t plen,
				   size_t *len, unsigned char **p, int *is_sign, int *is_last);
size_t add_pseudoheader(struct dns_header *header, size_t plen, unsigned char *limit, 
			unsigned short udp_sz, int optno, unsigned char *opt, size_t optlen, int set_do, int replace);
size_t add_do_bit(struct dns_header *header, size_t plen, unsigned char *limit);
size_t add_edns0_config(struct dns_header *header, size_t plen, unsigned char *limit, 
			union mysockaddr *source, time_t now, int *cacheable);
int check_source(struct dns_header *header, size_t plen, unsigned char *pseudoheader, union mysockaddr *peer);

/* arp.c */
int find_mac(union mysockaddr *addr, unsigned char *mac, int lazy, time_t now);
int do_arp_script_run(void);

/* dump.c */
#ifdef HAVE_DUMPFILE
void dump_init(void);
void dump_packet_udp(int mask, void *packet, size_t len, union mysockaddr *src,
		     union mysockaddr *dst, int fd);
void dump_packet_icmp(int mask, void *packet, size_t len, union mysockaddr *src,
		      union mysockaddr *dst);
#endif

/* domain-match.c */
void build_server_array(void);
int lookup_domain(char *qdomain, int flags, int *lowout, int *highout);
int filter_servers(int seed, int flags, int *lowout, int *highout);
int is_local_answer(time_t now, int first, char *name);
size_t make_local_answer(int flags, int gotname, size_t size, struct dns_header *header,
			 char *name, char *limit, int first, int last, int ede);
int server_samegroup(struct server *a, struct server *b);
#ifdef HAVE_DNSSEC
int dnssec_server(struct server *server, char *keyname, int *firstp, int *lastp);
#endif
void mark_servers(int flag);
void cleanup_servers(void);
int add_update_server(int flags,
		      union mysockaddr *addr,
		      union mysockaddr *source_addr,
		      const char *interface,
		      const char *domain,
		      union all_addr *local_addr);