/*      $NetBSD: syslogd.h,v 1.11 2026/07/03 10:10:36 msaitoh Exp $     */

/*-
 * Copyright (c) 2008 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Martin Schütte.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
#ifndef SYSLOGD_H_
#define SYSLOGD_H_
/*
 * hold common data structures and prototypes
 * for syslogd.c and tls.c
 *
 */

#include <sys/cdefs.h>
#define MAXLINE         1024            /* maximum line length */
#define DEFUPRI         (LOG_USER|LOG_NOTICE)
#define DEFSPRI         (LOG_KERN|LOG_NOTICE)
#define TIMERINTVL      30              /* interval for checking flush, mark */
#define TTYMSGTIME      1               /* timeout passed to ttymsg */

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/types.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <sys/queue.h>
#include <netinet/in.h>
#include <sys/event.h>
#include <event.h>

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <locale.h>
#include <netdb.h>
#include <pwd.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdbool.h>
#include <utmp.h>
#ifdef __NetBSD_Version__
#include <util.h>
#include "utmpentry.h"
#endif /* __NetBSD_Version__ */
#ifdef __FreeBSD_version
#include <libutil.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <limits.h>
#endif /* __FreeBSD_version */

#ifndef DISABLE_TLS
#include <netinet/tcp.h>
#include <openssl/ssl.h>
#endif /* !DISABLE_TLS */

#include <sys/stdint.h>
#include <sys/resource.h>

#include "pathnames.h"
#include <sys/syslog.h>

/* some differences between the BSDs  */
#ifdef __FreeBSD_version
#undef _PATH_UNIX
#define _PATH_UNIX "kernel"
#define HAVE_STRNDUP 0
#endif /* __FreeBSD_version */

#ifdef __NetBSD_Version__
#define HAVE_STRNDUP 1
#define HAVE_DEHUMANIZE_NUMBER 1
#endif /* __NetBSD_Version__ */

#ifndef HAVE_DEHUMANIZE_NUMBER  /* not in my 4.0-STABLE yet */
extern int dehumanize_number(const char *str, int64_t *size);
#endif /* !HAVE_DEHUMANIZE_NUMBER */

#if !HAVE_STRNDUP
char *strndup(const char *str, size_t n);
#endif /* !HAVE_STRNDUP */

#ifdef LIBWRAP
#include <tcpd.h>
#endif

#define FDMASK(fd)      (1 << (fd))

#define A_CNT(x)        (sizeof((x)) / sizeof((x)[0]))

/* debug messages with categories */
#define D_NONE     0
#define D_CALL     1    /* function calls */
#define D_DATA     2    /* syslog message reading/formatting */
#define D_NET      4    /* sockets/network */
#define D_FILE     8    /* local files */
#define D_TLS     16    /* TLS */
#define D_PARSE   32    /* configuration/parsing */
#define D_EVENT   64    /* libevent */
#define D_BUFFER 128    /* message queues */
#define D_MEM    256    /* malloc/free */
#define D_MEM2  1024    /* every single malloc/free */
#define D_SIGN  2048    /* -sign */
#define D_MISC  4096    /* everything else */
#define D_ALL   (D_CALL | D_DATA | D_NET | D_FILE | D_TLS | D_PARSE |  \
                 D_EVENT | D_BUFFER | D_MEM | D_MEM2 | D_SIGN | D_MISC)
#define D_DEFAULT (D_CALL | D_NET | D_FILE | D_TLS | D_MISC)


/* build with -DNDEBUG to remove all assert()s and DPRINTF()s */
#ifdef NDEBUG
#define DPRINTF(x, ...) (void)0
#else
void dbprintf(const char *, const char *, size_t, const char *, ...)
    __printflike(4, 5);
#define DPRINTF(x, ...) /*LINTED null effect */(void)(Debug & (x) \
    ? dbprintf(__FILE__, __func__, __LINE__, __VA_ARGS__) : ((void)0))
#endif

/* shortcuts for libevent */
#define EVENT_ADD(x) do {                                               \
        DPRINTF(D_EVENT, "event_add(%s@%p)\n", #x, x);                  \
        if (event_add(x, NULL) == -1) {                                 \
                DPRINTF(D_EVENT, "Failure in event_add()\n");           \
        }                                                               \
} while (0)
#define RETRYEVENT_ADD(x) do {                                          \
        struct timeval _tv;                                             \
        _tv.tv_sec = 0;                                                 \
        _tv.tv_usec = TLS_RETRY_EVENT_USEC;                             \
        DPRINTF(D_EVENT, "retryevent_add(%s@%p)\n", #x, x);             \
        if (event_add(x, &_tv) == -1) {                                 \
                DPRINTF(D_EVENT, "Failure in event_add()\n");           \
        }                                                               \
} while (0)
#define DEL_EVENT(x) do {                                               \
        DPRINTF(D_MEM2, "DEL_EVENT(%s@%p)\n", #x, x);                   \
        if ((x) && (event_del(x) == -1)) {                              \
                DPRINTF(D_EVENT, "Failure in event_del()\n");           \
        }                                                               \
} while (0)

/* safe calls to free() */
#define FREEPTR(x)      if (x) {                                        \
                DPRINTF(D_MEM2, "free(%s@%p)\n", #x, x);                \
                free(x);         x = NULL; }
#define FREE_SSL(x)     if (x) {                                        \
                DPRINTF(D_MEM2, "SSL_free(%s@%p)\n", #x, x);            \
                SSL_free(x);     x = NULL; }
#define FREE_SSL_CTX(x) if (x) {                                        \
                DPRINTF(D_MEM2, "SSL_CTX_free(%s@%p)\n", #x, x);        \
                SSL_CTX_free(x); x = NULL; }

/* reference counting macros for buffers */
#define NEWREF(x) ((x) ? (DPRINTF(D_BUFFER, "inc refcount of " #x       \
                        " @ %p: %zu --> %zu\n", (x), (x)->refcount,     \
                        (x)->refcount + 1), (x)->refcount++, (x))       \
                        : (DPRINTF(D_BUFFER, "inc refcount of NULL!\n"), NULL))
#define DELREF(x) /*LINTED null effect*/                                \
                        (void)((x) ? (DPRINTF(D_BUFFER, "dec refcount of " #x \
                        " @ %p: %zu --> %zu\n", (x), (x)->refcount,     \
                        (x)->refcount - 1), buf_msg_free(x), NULL)      \
                        : (DPRINTF(D_BUFFER, "dec refcount of NULL!\n"), NULL))

/* assumption:
 * - malloc()/calloc() only fails if not enough memory available
 * - once init() has set up all global variables etc.
 *   the bulk of available memory is used for buffers
 *   and can be freed if necessary
 */
#define MALLOC(ptr, size) do {                                          \
        while (!(ptr = malloc(size))) {                                 \
                DPRINTF(D_MEM, "Unable to allocate memory");            \
                message_allqueues_purge();                              \
        }                                                               \
        DPRINTF(D_MEM2, "MALLOC(%s@%p, %zu)\n", #ptr, ptr, size);       \
} while (0)

#define CALLOC(ptr, size) do {                                          \
        while (!(ptr = calloc(1, size))) {                              \
                DPRINTF(D_MEM, "Unable to allocate memory");            \
                message_allqueues_purge();                              \
        }                                                               \
        DPRINTF(D_MEM2, "CALLOC(%s@%p, %zu)\n", #ptr, ptr, size);       \
} while (0)

/* define strlen(NULL) to be 0 */
#define SAFEstrlen(x) ((x) ? strlen(x) : 0)

/* shorthand to block/restore signals for the duration of one function */
#define BLOCK_SIGNALS(omask, newmask) do {                              \
        sigemptyset(&newmask);                                          \
        sigaddset(&newmask, SIGHUP);                                    \
        sigaddset(&newmask, SIGALRM);                                   \
        sigprocmask(SIG_BLOCK, &newmask, &omask);                       \
} while (0)

#define RESTORE_SIGNALS(omask) sigprocmask(SIG_SETMASK, &omask, NULL)

/* small optimization to call send_queue() only if queue has elements */
#define SEND_QUEUE(f) do {                                              \
        if ((f)->f_qelements)                                           \
                send_queue(0, 0, f);                                    \
} while (0)

#define MAXUNAMES               20      /* maximum number of user names */
#define BSD_TIMESTAMPLEN        (14+1)
#define MAX_TIMESTAMPLEN        (31+1)

/* maximum field lengths in syslog-protocol */
#define PRI_MAX       5
#define HOST_MAX    255
#define APPNAME_MAX  48
#define PROCID_MAX  128
#define MSGID_MAX    32
/* longest possible header length */
#define HEADER_LEN_MAX (PRI_MAX + 1 + 1 + MAX_TIMESTAMPLEN + 1 + HOST_MAX \
                        + 1 + APPNAME_MAX + 1 + PROCID_MAX + 1 + MSGID_MAX)

/* allowed number of priorities by IETF standards */
#define IETF_NUM_PRIVALUES  192

/* check if message with fac/sev belogs to a destination f */
#define MATCH_PRI(f, fac, sev) \
           (  (((f)->f_pcmp[fac] & PRI_EQ) && ((f)->f_pmask[fac] == (sev))) \
            ||(((f)->f_pcmp[fac] & PRI_LT) && ((f)->f_pmask[fac]  < (sev)))  \
            ||(((f)->f_pcmp[fac] & PRI_GT) && ((f)->f_pmask[fac]  > (sev)))  \
           )

/* shorthand to test Byte Order Mark which indicates UTF-8 content */
#define IS_BOM(p) ( \
    (p)[0] != '\0' && (unsigned char)(p)[0] == (unsigned char)0xEF && \
    (p)[1] != '\0' && (unsigned char)(p)[1] == (unsigned char)0xBB && \
    (p)[2] != '\0' && (unsigned char)(p)[2] == (unsigned char)0xBF)

/* message buffer container used for processing, formatting, and queueing */
struct buf_msg {
        size_t   refcount;
        int      pri;
        int      flags;
        char    *timestamp;
        char    *recvhost;
        char    *host;
        char    *prog;
        char    *pid;
        char    *msgid;
        char    *sd;        /* structured data */
        char    *msg;       /* message content */
        char    *msgorig;   /* in case we advance *msg beyond header fields
                               we still want to free() the original ptr  */
        size_t   msglen;    /* strlen(msg) */
        size_t   msgsize;   /* allocated memory size   */
        size_t   tlsprefixlen; /* bytes for the TLS length prefix */
        size_t   prilen;       /* bytes for priority and version  */
};

/* queue of messages */
struct buf_queue {
        struct buf_msg* msg;
        STAILQ_ENTRY(buf_queue) entries;
};
STAILQ_HEAD(buf_queue_head, buf_queue);

/* a pair of a socket and an associated event object */
struct socketEvent {
        int fd;
        int af;
        struct event *ev;
};

/*
 * Flags to logmsg().
 */
#define IGN_CONS        0x001   /* don't print on console */
#define SYNC_FILE       0x002   /* do fsync on file after printing */
#define ADDDATE         0x004   /* add a date to the message */
#define MARK            0x008   /* this message is a mark */
#define ISKERNEL        0x010   /* kernel generated message */
#define BSDSYSLOG       0x020   /* line in traditional BSD Syslog format */
#define SIGN_MSG        0x040   /* syslog-sign data, not signed again */

/* strategies for message_queue_purge() */
#define PURGE_OLDEST            1
#define PURGE_BY_PRIORITY       2

/*
 * This structure represents the files that will have log
 * copies printed.
 * We require f_file to be valid if f_type is F_FILE, F_CONSOLE, F_TTY,
 * or if f_type is F_PIPE and f_pid > 0.
 */

struct filed {
        struct  filed *f_next;          /* next in linked list */
        short   f_type;                 /* entry type, see below */
        short   f_file;                 /* file descriptor */
        time_t  f_time;                 /* time this was last written */
        char    *f_host;                /* host from which to record */
        u_char  f_pmask[LOG_NFACILITIES+1];     /* priority mask */
        u_char  f_pcmp[LOG_NFACILITIES+1];      /* compare priority */
#define PRI_LT  0x1
#define PRI_EQ  0x2
#define PRI_GT  0x4
        char    *f_program;             /* program this applies to */
        union {
                char    f_uname[MAXUNAMES][UT_NAMESIZE+1];
                struct {
                        char    f_hname[MAXHOSTNAMELEN];
                        struct  addrinfo *f_addr;
                } f_forw;               /* UDP forwarding address */
#ifndef DISABLE_TLS
                struct {
                        SSL     *ssl;                   /* SSL object  */
                        struct tls_conn_settings *tls_conn;  /* certificate info */
                } f_tls;                /* TLS forwarding address */
#endif /* !DISABLE_TLS */
                char    f_fname[MAXPATHLEN];
                struct {
                        char    f_pname[MAXPATHLEN];
                        pid_t   f_pid;
                } f_pipe;
        } f_un;
#ifndef DISABLE_SIGN
        struct signature_group_t *f_sg;      /* one signature group */
#endif /* !DISABLE_SIGN */
        struct buf_queue_head f_qhead;       /* undelivered msgs queue */
        size_t                f_qelements;   /* elements in queue */
        size_t                f_qsize;       /* size of queue in bytes */
        struct buf_msg       *f_prevmsg;     /* last message logged */
        struct event         *f_sq_event;    /* timer for send_queue() */
        int                   f_prevcount;   /* repetition cnt of prevmsg */
        int                   f_repeatcount; /* number of "repeated" msgs */
        int                   f_lasterror;   /* last error on writev() */
        int                   f_flags;       /* file-specific flags */
#define FFLAG_SYNC      0x01    /* for F_FILE: fsync after every msg */
#define FFLAG_FULL      0x02    /* for F_FILE | F_PIPE: write PRI header */
#define FFLAG_SIGN      0x04    /* for syslog-sign with SG="3":
                                 * sign the messages to this destination */
};

#ifndef DISABLE_TLS

/* linked list for allowed TLS peer credentials
 * (one for fingerprint, one for cert-files)
 */
SLIST_HEAD(peer_cred_head, peer_cred);
struct peer_cred {
        SLIST_ENTRY(peer_cred) entries;
        char *data;
};

/* config options for TLS server-side */
struct tls_global_options_t {
        SSL_CTX *global_TLS_CTX;
        struct peer_cred_head fprint_head;  /* trusted client fingerprints */
        struct peer_cred_head cert_head;    /* trusted client cert files   */
        char *keyfile;      /* file with private key     */
        char *certfile;     /* file with own certificate */
        char *CAfile;       /* file with CA certificate  */
        char *CAdir;        /* alternative: path to directory with CA certs */
        char *x509verify;   /* level of peer verification */
        char *bindhost;     /* hostname/IP to bind to     */
        char *bindport;     /* port/service to bind to    */
        char *server;       /* if !NULL: do not listen to incoming TLS    */
        char *gen_cert;     /* if !NULL: generate self-signed certificate */
};

/* TLS needs three sets of sockets:
 * - listening sockets: a fixed size array TLS_Listen_Set, just like finet for UDP.
 * - outgoing connections: managed as part of struct filed.
 * - incoming connections: variable sized, thus a linked list TLS_Incoming.
 */
/* every connection has its own input buffer with status
 * variables for message reading */
SLIST_HEAD(TLS_Incoming, TLS_Incoming_Conn);

struct TLS_Incoming_Conn {
        SLIST_ENTRY(TLS_Incoming_Conn) entries;
        struct tls_conn_settings *tls_conn;
        int socket;
        char *inbuf;                /* input buffer */
        size_t inbuflen;
        size_t cur_msg_len;         /* length of current msg */
        size_t cur_msg_start;       /* beginning of current msg */
        size_t read_pos;            /* ring buffer position to write to */
        size_t errorcount;          /* to close faulty connections */
        bool closenow;              /* close connection as soon as buffer processed */
        bool dontsave;              /* for receiving oversized messages w/o saving them */
};

#endif /* !DISABLE_TLS */

#endif /*SYSLOGD_H_*/