/*
 * nsd.h -- nsd(8) definitions and prototypes
 *
 * Copyright (c) 2001-2006, NLnet Labs. All rights reserved.
 *
 * See LICENSE for the license.
 *
 */

#ifndef	NSD_H
#define	NSD_H

#include <signal.h>
#include <net/if.h>
#ifndef IFNAMSIZ
#  ifdef IF_NAMESIZE
#    define IFNAMSIZ IF_NAMESIZE
#  else
#    define IFNAMSIZ 16
#  endif
#endif
#ifdef HAVE_OPENSSL_SSL_H
#include <openssl/ssl.h>
#endif

#include "dns.h"
#include "edns.h"
#include "bitset.h"
#ifdef USE_XDP
#include "xdp-server.h"
#endif
struct netio_handler;
struct nsd_options;
struct udb_base;
struct daemon_remote;
#ifdef USE_METRICS
struct daemon_metrics;
#endif /* USE_METRICS */
#ifdef USE_DNSTAP
struct dt_collector;
#endif

/* The NSD runtime states and NSD ipc command values */
#define	NSD_RUN	0
#define	NSD_RELOAD 1
#define	NSD_SHUTDOWN 2
#define	NSD_STATS 3
#define	NSD_REAP_CHILDREN 4
#define	NSD_QUIT 5
/*
 * RELOAD_REQ is sent when parent receives a SIGHUP and tells
 * xfrd that it wants to initiate a reload (and thus task swap).
 */
#define NSD_RELOAD_REQ 7
/*
 * RELOAD_DONE is sent at the end of a reload pass.
 * xfrd then knows that reload phase is over.
 */
#define NSD_RELOAD_DONE 8
/*
 * QUIT_SYNC is sent to signify a synchronisation of ipc
 * channel content during reload
 */
#define NSD_QUIT_SYNC 9
/*
 * QUIT_CHILD is sent at exit, to make sure the child has exited so that
 * port53 is free when all of nsd's processes have exited at shutdown time
 */
#define NSD_QUIT_CHILD 11
/*
 * This is the exit code of a nsd "new master" child process to indicate to
 * the master process that some zones failed verification and that it should
 * reload again, reprocessing the difffiles. The master process will resend
 * the command to xfrd so it will not reload from xfrd yet.
 */
#define NSD_RELOAD_FAILED 14

#define NSD_SERVER_MAIN 0x0U
#define NSD_SERVER_UDP  0x1U
#define NSD_SERVER_TCP  0x2U
#define NSD_SERVER_BOTH (NSD_SERVER_UDP | NSD_SERVER_TCP)

#ifdef INET6
#define DEFAULT_AI_FAMILY AF_UNSPEC
#else
#define DEFAULT_AI_FAMILY AF_INET
#endif

#ifdef BIND8_STATS
/* Counter for statistics */
typedef	unsigned long stc_type;

#define	LASTELEM(arr)	(sizeof(arr) / sizeof(arr[0]) - 1)

#define	STATUP(nsd, stc) nsd->st->stc++
/* #define	STATUP2(nsd, stc, i)  ((i) <= (LASTELEM(nsd->st->stc) - 1)) ? nsd->st->stc[(i)]++ : \
				nsd->st.stc[LASTELEM(nsd->st->stc)]++ */

#define	STATUP2(nsd, stc, i) nsd->st->stc[(i) <= (LASTELEM(nsd->st->stc) - 1) ? i : LASTELEM(nsd->st->stc)]++
#else	/* BIND8_STATS */

#define	STATUP(nsd, stc) /* Nothing */
#define	STATUP2(nsd, stc, i) /* Nothing */

#endif /* BIND8_STATS */

#ifdef USE_ZONE_STATS
/* increment zone statistic, checks if zone-nonNULL and zone array bounds */
#define ZTATUP(nsd, zone, stc) ( \
	(zone && zone->zonestatid < nsd->zonestatsizenow) ? \
		nsd->zonestatnow[zone->zonestatid].stc++ \
		: 0)
#define	ZTATUP2(nsd, zone, stc, i) ( \
	(zone && zone->zonestatid < nsd->zonestatsizenow) ? \
		(nsd->zonestatnow[zone->zonestatid].stc[(i) <= (LASTELEM(nsd->zonestatnow[zone->zonestatid].stc) - 1) ? i : LASTELEM(nsd->zonestatnow[zone->zonestatid].stc)]++ ) \
		: 0)
#else /* USE_ZONE_STATS */
#define	ZTATUP(nsd, zone, stc) /* Nothing */
#define	ZTATUP2(nsd, zone, stc, i) /* Nothing */
#endif /* USE_ZONE_STATS */

#ifdef	BIND8_STATS
/* Data structure to keep track of statistics */
struct nsdst {
	time_t	boot;
	stc_type reloadcount;	/* counts reloads */
	stc_type qtype[257];	/* Counters per qtype */
	stc_type qclass[4];	/* Class IN or Class CH or other */
	stc_type qudp, qudp6;	/* Number of queries udp and udp6 */
	stc_type ctcp, ctcp6;	/* Number of tcp and tcp6 connections */
	stc_type ctls, ctls6;	/* Number of tls and tls6 connections */
	stc_type rcode[17], opcode[6]; /* Rcodes & opcodes */
	/* Dropped, truncated, queries for nonconfigured zone, tx errors */
	stc_type dropped, truncated, wrongzone, txerr, rxerr;
	stc_type edns, ednserr, raxfr, nona, rixfr;
	uint64_t db_disk, db_mem;
};
#endif /* BIND8_STATS */

#define NSD_SOCKET_IS_OPTIONAL (1<<0)
#define NSD_BIND_DEVICE (1<<1)

struct nsd_addrinfo
{
	int ai_flags;
	int ai_family;
	int ai_socktype;
	socklen_t ai_addrlen;
	struct sockaddr_storage ai_addr;
};

struct nsd_socket
{
	struct nsd_addrinfo addr;
	int s;
	int flags;
	struct nsd_bitset *servers;
	char device[IFNAMSIZ];
	int fib;
};

struct nsd_child
{
#ifdef HAVE_CPUSET_T
	/* Processor(s) that child process must run on (if applicable). */
	cpuset_t *cpuset;
#endif

	/* The type of child process (UDP or TCP handler). */
	int kind;

	/* The child's process id.  */
	pid_t pid;

	/* child number in child array */
	int child_num;

	/*
	 * Socket used by the parent process to send commands and
	 * receive responses to/from this child process.
	 */
	int child_fd;

	/*
	 * Socket used by the child process to receive commands and
	 * send responses from/to the parent process.
	 */
	int parent_fd;

	/*
	 * IPC info, buffered for nonblocking writes to the child
	 */
	uint8_t need_to_send_STATS, need_to_send_QUIT;
	uint8_t need_to_exit, has_exited;

	/*
	 * The handler for handling the commands from the child.
	 */
	struct netio_handler* handler;

#ifdef	BIND8_STATS
	stc_type query_count;
#endif
};

#define NSD_COOKIE_HISTORY_SIZE 2
#define NSD_COOKIE_SECRET_SIZE 16

struct cookie_secret {
	/** cookie secret */
	uint8_t cookie_secret[NSD_COOKIE_SECRET_SIZE];
};
typedef struct cookie_secret cookie_secret_type;
typedef cookie_secret_type cookie_secrets_type[NSD_COOKIE_HISTORY_SIZE];

enum cookie_secrets_source {
	COOKIE_SECRETS_NONE        = 0,
	COOKIE_SECRETS_GENERATED   = 1,
	COOKIE_SECRETS_FROM_FILE   = 2,
	COOKIE_SECRETS_FROM_CONFIG = 3
};
typedef enum cookie_secrets_source cookie_secrets_source_type;

/* NSD configuration and run-time variables */
typedef struct nsd nsd_type;
struct	nsd
{
	/*
	 * Global region that is not deallocated until NSD shuts down.
	 */
	region_type    *region;

	/* Run-time variables */
	pid_t		pid;
	volatile sig_atomic_t mode;
	volatile sig_atomic_t signal_hint_reload_hup;
	volatile sig_atomic_t signal_hint_reload;
	volatile sig_atomic_t signal_hint_child;
	volatile sig_atomic_t signal_hint_quit;
	volatile sig_atomic_t signal_hint_shutdown;
	volatile sig_atomic_t signal_hint_stats;
	volatile sig_atomic_t signal_hint_statsusr;
	volatile sig_atomic_t quit_sync_done;
	unsigned		server_kind;
	struct namedb	*db;
	int				debug;

	size_t            child_count;
	struct nsd_child *children;
	int	restart_children;
	int	reload_failed;

	/* NULL if this is the parent process. */
	struct nsd_child *this_child;

	/* mmaps with data exchange from xfrd and reload */
	struct udb_base* task[2];
	int mytask;
	/* the base used by this (child)process */
	struct event_base* event_base;
	/* the server_region used by this (child)process */
	region_type* server_region;
	struct netio_handler* xfrd_listener;
	struct daemon_remote* rc;
#ifdef USE_METRICS
	struct daemon_metrics* metrics;
#endif /* USE_METRICS */

	/* Configuration */
	const char		*pidfile;
	const char		*log_filename;
	const char		*username;
	uid_t			uid;
	gid_t			gid;
	const char		*chrootdir;
	const char		*version;
	const char		*identity;
	uint16_t		nsid_len;
	unsigned char		*nsid;
	uint8_t 		file_rotation_ok;

#ifdef HAVE_CPUSET_T
	int			use_cpu_affinity;
	cpuset_t*		cpuset;
	cpuset_t*		xfrd_cpuset;
#endif

	/* number of interfaces */
	size_t	ifs;
	/* non0 if so_reuseport is in use, if so, tcp, udp array increased */
	int reuseport;

	/* TCP specific configuration (array size ifs) */
	struct nsd_socket* tcp;

	/* UDP specific configuration (array size ifs) */
	struct nsd_socket* udp;

	/* Interfaces used for zone verification */
	size_t verify_ifs;
	struct nsd_socket *verify_tcp;
	struct nsd_socket *verify_udp;

	struct zone *next_zone_to_verify;
	size_t verifier_count; /* Number of active verifiers */
	size_t verifier_limit; /* Maximum number of active verifiers */
	int verifier_pipe[2]; /* Pipe to trigger verifier exit handler */
	struct verifier *verifiers;

#ifdef USE_XDP
	struct {
		/* only one interface for now */
		struct xdp_server xdp_server;
	} xdp;
#endif

	edns_data_type edns_ipv4;
#if defined(INET6)
	edns_data_type edns_ipv6;
#endif

	int maximum_tcp_count;
	int current_tcp_count;
	int tcp_query_count;
	int tcp_timeout;
	int tcp_mss;
	int outgoing_tcp_mss;
	size_t ipv4_edns_size;
	size_t ipv6_edns_size;

#ifdef	BIND8_STATS
	/* statistics for this server */
	struct nsdst* st;
	/* Produce statistics dump every st_period seconds */
	int st_period;
	/* per zone stats, each an array per zone-stat-idx, stats per zone is
	 * add of [0][zoneidx] and [1][zoneidx]. */
	struct nsdst* zonestat[2];
	/* fd for zonestat mapping (otherwise mmaps cannot be shared between
	 * processes and resized) */
	int zonestatfd[2];
	/* filenames */
	char* zonestatfname[2];
	/* size of the mmapped zone stat array (number of array entries) */
	size_t zonestatsize[2], zonestatdesired, zonestatsizenow;
	/* current zonestat array to use */
	struct nsdst* zonestatnow;
	/* filenames for stat file mappings */
	char* statfname;
	/* fd for stat mapping (otherwise mmaps cannot be shared between
	 * processes and resized) */
	int statfd;
	/* statistics array, of size child_count*2, twice for old and new
	 * server processes. */
	struct nsdst* stat_map;
	/* statistics array of size child_count, twice */
	struct nsdst* stats_per_child[2];
	/* current stats_per_child array that is in use for the child set */
	int stat_current;
	/* start value for per process statistics printout, to clear it */
	struct nsdst stat_proc;
#endif /* BIND8_STATS */
#ifdef USE_DNSTAP
	/* the dnstap collector process info */
	struct dt_collector* dt_collector;
	/* the pipes from server processes to the dt_collector,
	 * arrays of size child_count * 2.  Kept open for (re-)forks. */
	int *dt_collector_fd_send, *dt_collector_fd_recv;
	/* the pipes from server processes to the dt_collector. Initially
	 * these point halfway into dt_collector_fd_send, but during reload
	 * the pointer is swapped with dt_collector_fd_send in order to
	 * to prevent writing to the dnstap collector by old serve childs
	 * simultaneous with new serve childs. */
	int *dt_collector_fd_swap;
#endif /* USE_DNSTAP */
	/* the pipes from the serve processes to xfrd, for passing through
	 * NOTIFY messages, arrays of size child_count * 2.
	 * Kept open for (re-)forks. */
	int *serve2xfrd_fd_send, *serve2xfrd_fd_recv;
	/* the pipes from the serve processes to the xfrd. Initially
	 * these point halfway into serve2xfrd_fd_send, but during reload
	 * the pointer is swapped with serve2xfrd_fd_send so that only one
	 * serve child will write to the same fd simultaneously. */
	int *serve2xfrd_fd_swap;
	/* ratelimit for errors, time value */
	time_t err_limit_time;
	/* ratelimit for errors, packet count */
	unsigned int err_limit_count;

	/* do answer with server cookie when request contained cookie option */
	int do_answer_cookie;

	/* how many cookies are there in the cookies array */
	size_t cookie_count;

	/* keep track of the last `NSD_COOKIE_HISTORY_SIZE`
	 * cookies as per rfc requirement .*/
	cookie_secrets_type cookie_secrets;

	/* From where came the configured cookies */
	cookie_secrets_source_type cookie_secrets_source;

	/* The cookie secrets filename when they came from file; when
	 * cookie_secrets_source == COOKIE_SECRETS_FROM_FILE */
	char* cookie_secrets_filename;

	struct nsd_options* options;

#ifdef HAVE_SSL
	/* TLS specific configuration */
	SSL_CTX *tls_ctx;
	SSL_CTX *tls_auth_ctx;
#endif
};

extern struct nsd nsd;

/* nsd.c */
pid_t readpid(const char *file);
int writepid(struct nsd *nsd);
void unlinkpid(const char* file, const char* username);
void sig_handler(int sig);
void bind8_stats(struct nsd *nsd);

/* server.c */
int server_init(struct nsd *nsd);
int server_prepare(struct nsd *nsd);
void server_main(struct nsd *nsd);
void server_child(struct nsd *nsd);
void server_shutdown(struct nsd *nsd) ATTR_NORETURN;
void server_close_all_sockets(struct nsd_socket sockets[], size_t n);
const char* nsd_event_vs(void);
const char* nsd_event_method(void);
struct event_base* nsd_child_event_base(void);
void service_remaining_tcp(struct nsd* nsd);
/* extra domain numbers for temporary domains */
#define EXTRA_DOMAIN_NUMBERS 1024
#define SLOW_ACCEPT_TIMEOUT 2 /* in seconds */
/* ratelimit for error responses */
#define ERROR_RATELIMIT 100 /* qps */
/* allocate zonestat structures */
void server_zonestat_alloc(struct nsd* nsd);
/* remap the mmaps for zonestat isx, to bytesize sz.  Caller has to set
 * the zonestatsize */
void zonestat_remap(struct nsd* nsd, int idx, size_t sz);
/* allocate stat structures */
void server_stat_alloc(struct nsd* nsd);
/* free stat mmap file, unlinks it */
void server_stat_free(struct nsd* nsd);
/* allocate and init xfrd variables */
void server_prepare_xfrd(struct nsd *nsd);
/* start xfrdaemon (again) */
void server_start_xfrd(struct nsd *nsd, int del_db, int reload_active);
/* send SOA serial numbers to xfrd */
void server_send_soa_xfrd(struct nsd *nsd, int shortsoa);
#ifdef HAVE_SSL
SSL_CTX* server_tls_ctx_setup(char* key, char* pem, char* verifypem);
SSL_CTX* server_tls_ctx_create(struct nsd *nsd, char* verifypem, char* ocspfile);
void perform_openssl_init(void);
#endif
ssize_t block_read(struct nsd* nsd, int s, void* p, ssize_t sz, int timeout);

#endif	/* NSD_H */