/*	$OpenBSD: message.c,v 1.27 2015/01/20 09:00:16 guenther Exp $	*/

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * 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. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 */

#include <errno.h>
#include <limits.h>
#include <paths.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>

#include "defs.h"

/*
 * Message handling functions for both rdist and rdistd.
 */


#define MSGBUFSIZ	32*1024

int			debug = 0;		/* Debugging level */
int			nerrs = 0;		/* Number of errors */

/*
 * Message Types
 */
struct msgtype {
	int		mt_type;		/* Type (bit) */
	char	       *mt_name;		/* Name of message type */
} msgtypes[] = {
	{ MT_CHANGE,	"change" },
	{ MT_INFO,	"info" },
	{ MT_NOTICE,	"notice" },
	{ MT_NERROR,	"nerror" },
	{ MT_FERROR,	"ferror" },
	{ MT_WARNING,	"warning" },
	{ MT_VERBOSE,	"verbose" },
	{ MT_ALL,	"all" },
	{ MT_DEBUG,	"debug" },
	{ 0 },
};

/*
 * Description of message facilities
 */
struct msgfacility {
	/* compile time initialized data */
	int		mf_msgfac;		/* One of MF_* from below */
	char	       *mf_name;		/* Name of this facility */
	void	      (*mf_sendfunc)		/* Function to send msg */
			(struct msgfacility *, int, int, char *);
	/* run time initialized data */
	int		mf_msgtypes;		/* Bitmask of MT_* from above*/
	char	       *mf_filename;		/* Name of file */
	FILE	       *mf_fptr;		/* File pointer to output to */
};

/*
 * Message Facilities
 */
#define MF_STDOUT	1			/* Standard Output */
#define MF_NOTIFY	2			/* Notify mail service */
#define MF_FILE		3			/* A normal file */
#define MF_SYSLOG	4			/* syslog() */

static void msgsendstdout(struct msgfacility *, int, int, char *);
static void msgsendsyslog(struct msgfacility *, int, int, char *);
static void msgsendfile(struct msgfacility *, int, int, char *);
static void msgsendnotify(struct msgfacility *, int, int, char *);

/*
 * Message Facilities
 */
struct msgfacility msgfacility[] = {
	{ MF_STDOUT,	"stdout",	msgsendstdout },
	{ MF_FILE,	"file",		msgsendfile },
	{ MF_SYSLOG,	"syslog",	msgsendsyslog },
	{ MF_NOTIFY,	"notify",	msgsendnotify },
	{ 0 },
};

static struct msgfacility *getmsgfac(char *);
static struct msgtype *getmsgtype(char *);
static char *setmsgtypes(struct msgfacility *, char *);
static void _message(int, char *);
static void _debugmsg(int, char *);
static void _error(const char *);
static void _fatalerr(const char *);

/*
 * Print message logging usage message
 */
void
msgprusage(void)
{
	int i, x;

	(void) fprintf(stderr, "\nWhere <msgopt> is of form\n");
	(void) fprintf(stderr, 
       "\t<facility1>=<type1>,<type2>,...:<facility2>=<type1>,<type2>...\n");

	(void) fprintf(stderr, "Valid <facility> names:");

	for (i = 0; msgfacility[i].mf_name; ++i)
		(void) fprintf(stderr, " %s", msgfacility[i].mf_name);

	(void) fprintf(stderr, "\nValid <type> names:");
	for (x = 0; msgtypes[x].mt_name; ++x)
		(void) fprintf(stderr, " %s", msgtypes[x].mt_name);

	(void) fprintf(stderr, "\n");
}

/*
 * Print enabled message logging info
 */
void
msgprconfig(void)
{
	int i, x;
	static char buf[MSGBUFSIZ];

	debugmsg(DM_MISC, "Current message logging config:");
	for (i = 0; msgfacility[i].mf_name; ++i) {
		(void) snprintf(buf, sizeof(buf), "    %.*s=", 
			       (int)(sizeof(buf) - 7), msgfacility[i].mf_name);
		for (x = 0; msgtypes[x].mt_name; ++x)
			if (IS_ON(msgfacility[i].mf_msgtypes, 
				  msgtypes[x].mt_type)) {
				if (x > 0)
					(void) strlcat(buf, ",", sizeof(buf));
				(void) strlcat(buf, msgtypes[x].mt_name,
				    sizeof(buf));
			}
		debugmsg(DM_MISC, "%s", buf);
	}

}

/*
 * Get the Message Facility entry "name"
 */
static struct msgfacility *
getmsgfac(char *name)
{
	int i;

	for (i = 0; msgfacility[i].mf_name; ++i)
		if (strcasecmp(name, msgfacility[i].mf_name) == 0)
			return(&msgfacility[i]);

	return(NULL);
}

/*
 * Get the Message Type entry named "name"
 */
static struct msgtype *
getmsgtype(char *name)
{
	int i;

	for (i = 0; msgtypes[i].mt_name; ++i)
		if (strcasecmp(name, msgtypes[i].mt_name) == 0)
			return(&msgtypes[i]);

	return(NULL);
}

/*
 * Set Message Type information for Message Facility "msgfac" as
 * indicated by string "str".
 */
static char *
setmsgtypes(struct msgfacility *msgfac, char *str)
{
	static char ebuf[BUFSIZ];
	char *cp;
	char *strptr, *word;
	struct msgtype *mtp;

	/*
	 * MF_SYSLOG is the only supported message facility for the server
	 */
	if (isserver && (msgfac->mf_msgfac != MF_SYSLOG && 
			 msgfac->mf_msgfac != MF_FILE)) {
		(void) snprintf(ebuf, sizeof(ebuf),
		"The \"%.*s\" message facility cannot be used by the server.",
			        100, msgfac->mf_name);
		return(ebuf);
	}

	strptr = str;

	/*
	 * Do any necessary Message Facility preparation
	 */
	switch(msgfac->mf_msgfac) {
	case MF_FILE:
		/*
		 * The MF_FILE string should look like "<file>=<types>".
		 */
		if ((cp = strchr(strptr, '=')) == NULL)
			return(
			   "No file name found for \"file\" message facility");
		*cp++ = CNULL;

		if ((msgfac->mf_fptr = fopen(strptr, "w")) == NULL)
			fatalerr("Cannot open log file for writing: %s: %s.",
				 strptr, SYSERR);
		msgfac->mf_filename = xstrdup(strptr);

		strptr = cp;
		break;

	case MF_NOTIFY:
		break;

	case MF_STDOUT:
		msgfac->mf_fptr = stdout;
		break;

	case MF_SYSLOG:
		openlog(progname, LOG_PID, LOG_DAEMON);
		break;
	}

	/*
	 * Parse each type word
	 */
	msgfac->mf_msgtypes = 0;	/* Start from scratch */
	while (strptr) {
		word = strptr;
		if ((cp = strchr(strptr, ',')) != NULL)
			*cp++ = CNULL;
		strptr = cp;

		if ((mtp = getmsgtype(word)) != NULL) {
			msgfac->mf_msgtypes |= mtp->mt_type;
			/*
			 * XXX This is really a kludge until we add real
			 * control over debugging.
			 */
			if (!debug && isserver && 
			    strcasecmp(word, "debug") == 0)
				debug = DM_ALL;
		} else {
			(void) snprintf(ebuf, sizeof(ebuf),
				        "Message type \"%.*s\" is invalid.",
				        100, word);
			return(ebuf);
		}
	}

	return(NULL);
}

/*
 * Parse a message logging option string
 */
char *
msgparseopts(char *msgstr, int doset)
{
	static char ebuf[BUFSIZ], msgbuf[MSGBUFSIZ];
	char *cp, *optstr;
	char *word;
	struct msgfacility *msgfac;

	if (msgstr == NULL)
		return("NULL message string");

	/* strtok() is harmful */
	(void) strlcpy(msgbuf, msgstr, sizeof(msgbuf));

	/*
	 * Each <facility>=<types> list is separated by ":".
	 */
	for (optstr = strtok(msgbuf, ":"); optstr;
	     optstr = strtok(NULL, ":")) {

		if ((cp = strchr(optstr, '=')) == NULL)
			return("No '=' found");

		*cp++ = CNULL;
		word = optstr;
		if ((int)strlen(word) <= 0)
			return("No message facility specified");
		if ((int)strlen(cp) <= 0)
			return("No message type specified");

		if ((msgfac = getmsgfac(word)) == NULL) {
			(void) snprintf(ebuf, sizeof(ebuf),
				        "%.*s is not a valid message facility", 
				        100, word);
			return(ebuf);
		}
		
		if (doset) {
			char *mcp;

			if ((mcp = setmsgtypes(msgfac, cp)) != NULL)
				return(mcp);
		}
	}

	if (isserver && debug) {
		debugmsg(DM_MISC, "%s", getversion());
		msgprconfig();
	}

	return(NULL);
}

/*
 * Send a message to facility "stdout".
 * For rdistd, this is really the rdist client.
 */
static void
msgsendstdout(struct msgfacility *msgfac, int mtype, int flags, char *msgbuf)
{
	char cmd;

	if (isserver) {
		if (rem_w < 0 || IS_ON(flags, MT_NOREMOTE))
			return;

		cmd = CNULL;

		switch(mtype) {
		case MT_NERROR:		cmd = C_ERRMSG;		break;
		case MT_FERROR:		cmd = C_FERRMSG;	break;
		case MT_NOTICE:		cmd = C_NOTEMSG;	break;
		case MT_REMOTE:		cmd = C_LOGMSG;		break;
		}

		if (cmd != CNULL)
			(void) sendcmd(cmd, "%s", msgbuf);
	} else {
		switch(mtype) {
		case MT_FERROR:
		case MT_NERROR:
			if (msgbuf && *msgbuf) {
				(void) fprintf(stderr, "%s\n", msgbuf);
				(void) fflush(stderr);
			}
			break;

		case MT_DEBUG:
			/* 
			 * Only things that are strictly MT_DEBUG should
			 * be shown.
			 */
			if (flags != MT_DEBUG)
				return;
		case MT_NOTICE:
		case MT_CHANGE:
		case MT_INFO:
		case MT_VERBOSE:
		case MT_WARNING:
			if (msgbuf && *msgbuf) {
				(void) printf("%s\n", msgbuf);
				(void) fflush(stdout);
			}
			break;
		}
	}
}

/*
 * Send a message to facility "syslog"
 */
static void
msgsendsyslog(struct msgfacility *msgfac, int mtype, int flags, char *msgbuf)
{
	int syslvl = 0;

	if (!msgbuf || !*msgbuf)
		return;

	switch(mtype) {
#if	defined(SL_NERROR)
	case MT_NERROR:		syslvl = SL_NERROR;	break;
#endif
#if	defined(SL_FERROR)
	case MT_FERROR:		syslvl = SL_FERROR;	break;
#endif
#if	defined(SL_WARNING)
	case MT_WARNING:	syslvl = SL_WARNING;	break;
#endif
#if	defined(SL_CHANGE)
	case MT_CHANGE:		syslvl = SL_CHANGE;	break;
#endif
#if	defined(SL_INFO)
	case MT_SYSLOG:
	case MT_VERBOSE:
	case MT_INFO:		syslvl = SL_INFO;	break;
#endif
#if	defined(SL_NOTICE)
	case MT_NOTICE:		syslvl = SL_NOTICE;	break;
#endif
#if	defined(SL_DEBUG)
	case MT_DEBUG:		syslvl = SL_DEBUG;	break;
#endif
	}

	if (syslvl)
		syslog(syslvl, "%s", msgbuf);
}

/*
 * Send a message to a "file" facility.
 */
static void
msgsendfile(struct msgfacility *msgfac, int mtype, int flags, char *msgbuf)
{
	if (msgfac->mf_fptr == NULL)
		return;

	if (!msgbuf || !*msgbuf)
		return;

	(void) fprintf(msgfac->mf_fptr, "%s\n", msgbuf);
	(void) fflush(msgfac->mf_fptr);
}

/*
 * Same method as msgsendfile()
 */
static void
msgsendnotify(struct msgfacility *msgfac, int mtype, int flags, char *msgbuf)
{
	char *tempfile;

	if (IS_ON(flags, MT_DEBUG))
		return;

	if (!msgbuf || !*msgbuf)
		return;

	if (!msgfac->mf_fptr) {
		char *cp;
		int fd;
		size_t len;

		/*
		 * Create and open a new temporary file
		 */
		if ((cp = getenv("TMPDIR")) == NULL || *cp == '\0')
			cp = _PATH_TMP;
		len = strlen(cp) + 1 + sizeof(_RDIST_TMP);
		tempfile = xmalloc(len);
		(void) snprintf(tempfile, len, "%s/%s", cp, _RDIST_TMP);

		msgfac->mf_filename = tempfile;
		if ((fd = mkstemp(msgfac->mf_filename)) < 0 ||
		    (msgfac->mf_fptr = fdopen(fd, "w")) == NULL)
		    fatalerr("Cannot open notify file for writing: %s: %s.",
			msgfac->mf_filename, SYSERR);
		debugmsg(DM_MISC, "Created notify temp file '%s'",
			 msgfac->mf_filename);
	}

	if (msgfac->mf_fptr == NULL)
		return;

	(void) fprintf(msgfac->mf_fptr, "%s\n", msgbuf);
	(void) fflush(msgfac->mf_fptr);
}

/*
 * Insure currenthost is set to something reasonable.
 */
void
checkhostname(void)
{
	static char mbuf[HOST_NAME_MAX+1];
	char *cp;

	if (!currenthost) {
		if (gethostname(mbuf, sizeof(mbuf)) == 0) {
			if ((cp = strchr(mbuf, '.')) != NULL)
				*cp = CNULL;
			currenthost = xstrdup(mbuf);
		} else
			currenthost = "(unknown)";
	}
}

/*
 * Print a message contained in "msgbuf" if a level "lvl" is set.
 */
static void
_message(int flags, char *msgbuf)
{
	int i, x;
	static char mbuf[2048];

	if (msgbuf && *msgbuf) {
		/*
		 * Ensure no stray newlines are present
		 */
		msgbuf[strcspn(msgbuf, "\n")] = CNULL;

		checkhostname();
		if (strncmp(currenthost, msgbuf, strlen(currenthost)) == 0)
			(void) strlcpy(mbuf, msgbuf, sizeof(mbuf));
		else
			(void) snprintf(mbuf, sizeof(mbuf), 
					"%s: %s", currenthost, msgbuf);
	} else
		mbuf[0] = '\0';

	/*
	 * Special case for messages that only get
	 * logged to the system log facility
	 */
	if (IS_ON(flags, MT_SYSLOG)) {
		msgsendsyslog(NULL, MT_SYSLOG, flags, mbuf);
		return;
	}

	/*
	 * Special cases
	 */
	if (isserver && IS_ON(flags, MT_NOTICE)) {
		msgsendstdout(NULL, MT_NOTICE, flags, mbuf);
		return;
	} else if (isserver && IS_ON(flags, MT_REMOTE))
		msgsendstdout(NULL, MT_REMOTE, flags, mbuf);
	else if (isserver && IS_ON(flags, MT_NERROR))
		msgsendstdout(NULL, MT_NERROR, flags, mbuf);
	else if (isserver && IS_ON(flags, MT_FERROR))
		msgsendstdout(NULL, MT_FERROR, flags, mbuf);

	/*
	 * For each Message Facility, check each Message Type to see
	 * if the bits in "flags" are set.  If so, call the appropriate
	 * Message Facility to dispatch the message.
	 */
	for (i = 0; msgfacility[i].mf_name; ++i)
		for (x = 0; msgtypes[x].mt_name; ++x)
			/* 
			 * XXX MT_ALL should not be used directly 
			 */
			if (msgtypes[x].mt_type != MT_ALL &&
			    IS_ON(flags, msgtypes[x].mt_type) &&
			    IS_ON(msgfacility[i].mf_msgtypes,
				  msgtypes[x].mt_type))
				(*msgfacility[i].mf_sendfunc)(&msgfacility[i],
							   msgtypes[x].mt_type,
							      flags,
							      mbuf);
}

/*
 * Front-end to _message()
 */
void
message(int lvl, const char *fmt, ...)
{
	static char buf[MSGBUFSIZ];
	va_list args;

	va_start(args, fmt);
	(void) vsnprintf(buf, sizeof(buf), fmt, args);
	va_end(args);

	_message(lvl, buf);
}

/*
 * Display a debugging message
 */
static void
_debugmsg(int lvl, char *buf)
{
	if (IS_ON(debug, lvl))
		_message(MT_DEBUG, buf);
}

/*
 * Front-end to _debugmsg()
 */
void
debugmsg(int lvl, const char *fmt, ...)
{
	static char buf[MSGBUFSIZ];
	va_list args;

	va_start(args, fmt);
	(void) vsnprintf(buf, sizeof(buf), fmt, args);
	va_end(args);

	_debugmsg(lvl, buf);
}

/*
 * Print an error message
 */
static void
_error(const char *msg)
{
	static char buf[MSGBUFSIZ];

	nerrs++;
	buf[0] = CNULL;

	if (msg) {
		if (isserver)
			(void) snprintf(buf, sizeof(buf),
					"REMOTE ERROR: %s", msg);
		else
			(void) snprintf(buf, sizeof(buf),
					"LOCAL ERROR: %s", msg);
	}

	_message(MT_NERROR, (buf[0]) ? buf : NULL);
}

/*
 * Frontend to _error()
 */
void
error(const char *fmt, ...)
{
	static char buf[MSGBUFSIZ];
	va_list args;

	buf[0] = CNULL;
	va_start(args, fmt);
	if (fmt)
		(void) vsnprintf(buf, sizeof(buf), fmt, args);
	va_end(args);

	_error((buf[0]) ? buf : NULL);
}

/*
 * Display a fatal message
 */
static void
_fatalerr(const char *msg)
{
	static char buf[MSGBUFSIZ];

	++nerrs;

	if (isserver)
		(void) snprintf(buf, sizeof(buf), "REMOTE ERROR: %s", msg);
	else
		(void) snprintf(buf, sizeof(buf), "LOCAL ERROR: %s", msg);

	_message(MT_FERROR, buf);

	exit(nerrs);
}

/*
 * Front-end to _fatalerr()
 */
void
fatalerr(const char *fmt, ...)
{
	static char buf[MSGBUFSIZ];
	va_list args;

	va_start(args, fmt);
	(void) vsnprintf(buf, sizeof(buf), fmt, args);
	va_end(args);

	_fatalerr(buf);
}

/*
 * Get the name of the file used for notify.
 * A side effect is that the file pointer to the file
 * is closed.  We assume this function is only called when
 * we are ready to read the file.
 */
char *
getnotifyfile(void)
{
	int i;

	for (i = 0; msgfacility[i].mf_name; i++)
		if (msgfacility[i].mf_msgfac == MF_NOTIFY &&
		    msgfacility[i].mf_fptr) {
			(void) fclose(msgfacility[i].mf_fptr);
			msgfacility[i].mf_fptr = NULL;
			return(msgfacility[i].mf_filename);
		}

	return(NULL);
}