/*	$OpenBSD: newsyslog.c,v 1.12 1997/07/10 17:37:10 kstailey Exp $	*/

/*
 * Copyright (c) 1997, Jason Downs.  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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Jason Downs for the
 *      OpenBSD system.
 * 4. Neither the name(s) of the author(s) nor the name OpenBSD
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 AUTHOR(S) 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.
 */

/*
 * This file contains changes from the Open Software Foundation.
 */

/*

Copyright 1988, 1989 by the Massachusetts Institute of Technology

Permission to use, copy, modify, and distribute this software
and its documentation for any purpose and without fee is
hereby granted, provided that the above copyright notice
appear in all copies and that both that copyright notice and
this permission notice appear in supporting documentation,
and that the names of M.I.T. and the M.I.T. S.I.P.B. not be
used in advertising or publicity pertaining to distribution
of the software without specific, written prior permission.
M.I.T. and the M.I.T. S.I.P.B. make no representations about
the suitability of this software for any purpose.  It is
provided "as is" without express or implied warranty.

*/

/*
 *      newsyslog - roll over selected logs at the appropriate time,
 *              keeping the a specified number of backup files around.
 *
 */

#ifndef lint
static char rcsid[] = "$OpenBSD: newsyslog.c,v 1.12 1997/07/10 17:37:10 kstailey Exp $";
#endif /* not lint */

#ifndef CONF
#define CONF "/etc/athena/newsyslog.conf" /* Configuration file */
#endif
#ifndef PIDFILE
#define PIDFILE "/etc/syslog.pid"
#endif
#ifndef COMPRESS
#define COMPRESS "/usr/ucb/compress" /* File compression program */
#endif
#ifndef COMPRESS_POSTFIX
#define COMPRESS_POSTFIX ".Z"
#endif
#ifndef STATS_DIR
#define STATS_DIR "/etc"
#endif
#ifndef SENDMAIL
#define SENDMAIL "/usr/lib/sendmail"
#endif

#include <stdio.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <sys/wait.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <signal.h>
#include <fcntl.h>
#include <pwd.h>
#include <grp.h>
#include <unistd.h>
#include <err.h>

#define kbytes(size)  (((size) + 1023) >> 10)

#define CE_COMPACT	0x01		/* Compact the achived log files */
#define CE_BINARY	0x02		/* Logfile is in binary, don't add */
					/* status messages */
#define CE_MONITOR	0x04		/* Monitory for changes */
#define NONE -1
        
struct conf_entry {
        char    *log;           /* Name of the log */
        int     uid;            /* Owner of log */
        int     gid;            /* Group of log */
        int     numlogs;        /* Number of logs to keep */
        int     size;           /* Size cutoff to trigger trimming the log */
        int     hours;          /* Hours between log trimming */
        int     permissions;    /* File permissions on the log */
        int     flags;          /* Flags (CE_COMPACT & CE_BINARY)  */
	char	*whom;		/* Whom to notify if logfile changes */
        struct conf_entry       *next; /* Linked list pointer */
};

extern const char *__progname;

int     verbose = 0;            /* Print out what's going on */
int     needroot = 1;           /* Root privs are necessary */
int     noaction = 0;           /* Don't do anything, just show it */
int	monitor = 0;		/* Don't do monitoring by default */
char    *conf = CONF;           /* Configuration file to use */
time_t  timenow;
int     syslog_pid;             /* read in from /etc/syslog.pid */
#define MIN_PID		3
#define MAX_PID		65534
char    hostname[MAXHOSTNAMELEN]; /* hostname */
char    *daytime;               /* timenow in human readable form */


void do_entry __P((struct conf_entry *));
void PRS __P((int, char **));
void usage __P((void));
struct conf_entry *parse_file __P((void));
char *missing_field __P((char *, char *));
void dotrim __P((char *, int, int, int, int, int));
int log_trim __P((char *));
void compress_log __P((char *));
int sizefile __P((char *));
int age_old_log __P((char *));
char *sob __P((char *));
char *son __P((char *));
int isnumberstr __P((char *));
void domonitor __P((char *, char *));
FILE *openmail __P((void));
void closemail __P((FILE *));

int main(argc, argv)
        int argc;
        char **argv;
{
        struct conf_entry *p, *q;
        
        PRS(argc,argv);
        if (needroot && getuid() && geteuid())
		errx(1, "You must be root.");
        p = q = parse_file();
        while (p) {
                do_entry(p);
                p=p->next;
                free(q);
                q=p;
        }
        exit(0);
}

void do_entry(ent)
        struct conf_entry       *ent;
        
{
        int     size, modtime;
        
        if (verbose) {
                if (ent->flags & CE_COMPACT)
                        printf("%s <%dZ>: ",ent->log,ent->numlogs);
                else
                        printf("%s <%d>: ",ent->log,ent->numlogs);
        }
        size = sizefile(ent->log);
        modtime = age_old_log(ent->log);
        if (size < 0) {
                if (verbose)
                        printf("does not exist.\n");
        } else {
                if (verbose && (ent->size > 0))
                        printf("size (Kb): %d [%d] ", size, ent->size);
                if (verbose && (ent->hours > 0))
                        printf(" age (hr): %d [%d] ", modtime, ent->hours);
		if (monitor && ent->flags & CE_MONITOR)
			domonitor(ent->log, ent->whom);
                if (!monitor && ((ent->size > 0) && (size >= ent->size)) ||
                    ((ent->hours > 0) && ((modtime >= ent->hours)
                                        || (modtime < 0)))) {
                        if (verbose)
                                printf("--> trimming log....\n");
                        if (noaction && !verbose) {
                                if (ent->flags & CE_COMPACT)
                                        printf("%s <%dZ>: trimming",
                                               ent->log,ent->numlogs);
                                else
                                        printf("%s <%d>: trimming",
                                               ent->log,ent->numlogs);
                        }
                        dotrim(ent->log, ent->numlogs, ent->flags,
                               ent->permissions, ent->uid, ent->gid);
                } else {
                        if (verbose)
                                printf("--> skipping\n");
                }
        }
}

void PRS(argc, argv)
        int argc;
        char **argv;
{
        int     c;
        FILE    *f;
        char    line[BUFSIZ];
	char	*p;

        timenow = time(NULL);
        daytime = ctime(&timenow) + 4;
        daytime[15] = '\0';

        /* Let's find the pid of syslogd */
        syslog_pid = 0;
        f = fopen(PIDFILE,"r");
        if (f && fgets(line,BUFSIZ,f))
                syslog_pid = atoi(line);
	if (f)
		(void)fclose(f);

        /* Let's get our hostname */
        (void) gethostname(hostname, sizeof(hostname));

	/* Truncate domain */
	p = strchr(hostname, '.');
	if (p)
		*p = '\0';

        optind = 1;             /* Start options parsing */
        while ((c = getopt(argc,argv,"nrvmf:t:")) != -1) {
                switch (c) {
                case 'n':
                        noaction++; /* This implies needroot as off */
                        /* fall through */
                case 'r':
                        needroot = 0;
                        break;
                case 'v':
                        verbose++;
                        break;
                case 'f':
                        conf = optarg;
                        break;
		case 'm':
			monitor++;
			break;
                default:
                        usage();
                }
        }
}

void usage()
{
	errx(1, "usage: %s <-nrvm> <-f config-file>", __progname);
}

/* Parse a configuration file and return a linked list of all the logs
 * to process
 */
struct conf_entry *parse_file()
{
        FILE    *f;
        char    line[BUFSIZ], *parse, *q;
        char    *errline, *group;
        struct conf_entry *first = NULL;
        struct conf_entry *working;
        struct passwd *pass;
        struct group *grp;

        if (strcmp(conf,"-"))
                f = fopen(conf,"r");
        else
                f = stdin;
        if (!f)
		err(1, conf);

        while (fgets(line,BUFSIZ,f)) {
                if ((line[0]== '\n') || (line[0] == '#'))
                        continue;
                errline = strdup(line);
		if (errline == NULL)
			err(1, "strdup");
                if (!first) {
                        working = (struct conf_entry *) malloc(sizeof(struct conf_entry));
			if (working == NULL)
				err(1, "malloc");
                        first = working;
                } else {
                        working->next = (struct conf_entry *) malloc(sizeof(struct conf_entry));
			if (working->next == NULL)
				err(1, "malloc");
                        working = working->next;
                }

                q = parse = missing_field(sob(line),errline);
                *(parse = son(line)) = '\0';
                working->log = strdup(q);
		if (working->log == NULL)
			err(1, "strdup");

                q = parse = missing_field(sob(++parse),errline);
                *(parse = son(parse)) = '\0';
                if ((group = strchr(q, '.')) != NULL) {
                    *group++ = '\0';
                    if (*q) {
                        if (!(isnumberstr(q))) {
                            if ((pass = getpwnam(q)) == NULL)
				errx(1, "Error in config file; unknown user: %s", q);
                            working->uid = pass->pw_uid;
                        } else
                            working->uid = atoi(q);
                    } else
                        working->uid = NONE;
                    
                    q = group;
                    if (*q) {
                        if (!(isnumberstr(q))) {
                            if ((grp = getgrnam(q)) == NULL)
				errx(1, "Error in config file; unknown group: %s", q);
                            working->gid = grp->gr_gid;
                        } else
                            working->gid = atoi(q);
                    } else
                        working->gid = NONE;
                    
                    q = parse = missing_field(sob(++parse),errline);
                    *(parse = son(parse)) = '\0';
                } else 
                    working->uid = working->gid = NONE;

                if (!sscanf(q,"%o",&working->permissions))
			errx(1, "Error in config file; bad permissions: %s", q);

                q = parse = missing_field(sob(++parse),errline);
                *(parse = son(parse)) = '\0';
                if (!sscanf(q,"%d",&working->numlogs))
			errx(1, "Error in config file; bad number: %s", q);

                q = parse = missing_field(sob(++parse),errline);
                *(parse = son(parse)) = '\0';
                if (isdigit(*q))
                        working->size = atoi(q);
                else
                        working->size = -1;
                
                q = parse = missing_field(sob(++parse),errline);
                *(parse = son(parse)) = '\0';
                if (isdigit(*q))
                        working->hours = atoi(q);
                else
                        working->hours = -1;

                q = parse = sob(++parse); /* Optional field */
                *(parse = son(parse)) = '\0';
                working->flags = 0;
                while (q && *q && !isspace(*q)) {
                        if ((*q == 'Z') || (*q == 'z'))
                                working->flags |= CE_COMPACT;
                        else if ((*q == 'B') || (*q == 'b'))
                                working->flags |= CE_BINARY;
			else if ((*q == 'M') || (*q == 'm'))
				working->flags |= CE_MONITOR;
                        else
				errx(1, "Illegal flag in config file: %c", *q);
                        q++;
                }

		working->whom = NULL;
		if (working->flags & CE_MONITOR) {	/* Optional field */
			q = parse = sob(++parse);
			*(parse = son(parse)) = '\0';

			working->whom = strdup(q);
			if (working->log == NULL)
				err(1, "strdup");
		}
                
                free(errline);
        }
        if (working)
                working->next = NULL;
        (void) fclose(f);
        return(first);
}

char *missing_field(p, errline)
        char    *p,*errline;
{
        if (!p || !*p) {
                fprintf(stderr, "%s: Missing field in config file line:\n",
		    __progname);
                fputs(errline, stderr);
                exit(1);
        }
        return(p);
}

void dotrim(log, numdays, flags, perm, owner_uid, group_gid)
        char    *log;
        int     numdays;
        int     flags;
        int     perm;
        int     owner_uid;
        int     group_gid;
{
        char    file1[MAXPATHLEN], file2[MAXPATHLEN];
        char    zfile1[MAXPATHLEN], zfile2[MAXPATHLEN];
        int     fd;
        struct  stat st;
	int	days = numdays;

        /* Remove oldest log */
        (void) sprintf(file1,"%s.%d",log,numdays);
        (void) strcpy(zfile1, file1);
        (void) strcat(zfile1, COMPRESS_POSTFIX);

        if (noaction) {
                printf("rm -f %s\n", file1);
                printf("rm -f %s\n", zfile1);
        } else {
                (void) unlink(file1);
                (void) unlink(zfile1);
        }

        /* Move down log files */
        while (numdays--) {
                (void) strcpy(file2,file1);
                (void) sprintf(file1,"%s.%d",log,numdays);
                (void) strcpy(zfile1, file1);
                (void) strcpy(zfile2, file2);
                if (lstat(file1, &st)) {
                        (void) strcat(zfile1, COMPRESS_POSTFIX);
                        (void) strcat(zfile2, COMPRESS_POSTFIX);
                        if (lstat(zfile1, &st)) continue;
                }
                if (noaction) {
                        printf("mv %s %s\n",zfile1,zfile2);
                        printf("chmod %o %s\n", perm, zfile2);
                        printf("chown %d.%d %s\n",
                               owner_uid, group_gid, zfile2);
                } else {
                        (void) rename(zfile1, zfile2);
                        (void) chmod(zfile2, perm);
                        (void) chown(zfile2, owner_uid, group_gid);
                }
        }
        if (!noaction && !(flags & CE_BINARY))
                (void) log_trim(log);  /* Report the trimming to the old log */

	if (days == 0) {
		if (noaction)
			printf("rm %s\n",log);
		else
			(void) unlink(log);
	} else {
		if (noaction) 
	                printf("mv %s to %s\n",log,file1);
	        else
	                (void) rename(log,file1);
	}

        if (noaction) 
                printf("Start new log...");
        else {
                fd = creat(log,perm);
                if (fd < 0)
			err(1, "can't start new log");
                if (fchown(fd, owner_uid, group_gid))
			err(1, "can't chmod new log file");
                (void) close(fd);
                if (!(flags & CE_BINARY))
                        if (log_trim(log))	/* Add status message */
                                err(1, "can't add status message to log");
        }
        if (noaction)
                printf("chmod %o %s...",perm,log);
        else
                (void) chmod(log,perm);
        if (noaction)
                printf("kill -HUP %d (syslogd)\n",syslog_pid);
        else if (syslog_pid < MIN_PID || syslog_pid > MAX_PID)
		warnx("preposterous process number: %d", syslog_pid);
        else if (kill(syslog_pid,SIGHUP))
                        warnx("warning - could not restart syslogd");
        if (flags & CE_COMPACT) {
                if (noaction)
                        printf("Compress %s.0\n",log);
                else
                        compress_log(log);
        }
}

/* Log the fact that the logs were turned over */
int log_trim(log)
        char    *log;
{
        FILE    *f;
        if ((f = fopen(log,"a")) == NULL)
                return(-1);
        fprintf(f,"%s %s newsyslog[%d]: logfile turned over\n",
                daytime, hostname, getpid());
        if (fclose(f) == EOF) {
                err(1, "log_trim: fclose");
        }
        return(0);
}

/* Fork of /usr/ucb/compress to compress the old log file */
void compress_log(log)
        char    *log;
{
        int     pid;
        char    tmp[MAXPATHLEN];
        
        pid = fork();
        (void) sprintf(tmp,"%s.0",log);
        if (pid < 0) {
		err(1, "fork");
        } else if (!pid) {
                (void) execl(COMPRESS,"compress","-f",tmp,0);
		err(1, COMPRESS);
        }
}

/* Return size in kilobytes of a file */
int sizefile(file)
        char    *file;
{
        struct stat sb;

        if (stat(file,&sb) < 0)
                return(-1);
        return(kbytes(dbtob(sb.st_blocks)));
}

/* Return the age of old log file (file.0) */
int age_old_log(file)
        char    *file;
{
        struct stat sb;
        char tmp[MAXPATHLEN];

        (void) strcpy(tmp,file);
        if (stat(strcat(tmp,".0"),&sb) < 0)
            if (stat(strcat(tmp,COMPRESS_POSTFIX), &sb) < 0)
                return(-1);
        return( (int) (timenow - sb.st_mtime + 1800) / 3600);
}

/* Skip Over Blanks */
char *sob(p)
        register char   *p;
{
        while (p && *p && isspace(*p))
                p++;
        return(p);
}

/* Skip Over Non-Blanks */
char *son(p)
        register char   *p;
{
        while (p && *p && !isspace(*p))
                p++;
        return(p);
}

        
/* Check if string is actually a number */

int isnumberstr(string)
	char *string;
{
        while (*string != '\0') {
            if (!isdigit(*string++))
		return(0);
        }
        return(1);
}

void domonitor(log, whom)
	char *log, *whom;
{
	struct stat sb, tsb;
	char *fname, *flog, *p, *rb = NULL;
	FILE *fp;
	off_t osize;
	int rd;

	if (stat(log, &sb) < 0)
		return;

	flog = strdup(log);
	if (flog == NULL)
		err(1, "strdup");

	for (p = flog; *p != '\0'; p++) {
		if (*p == '/')
			*p = '_';
	}
	fname = (char *) malloc(strlen(STATS_DIR) + strlen(flog) + 17);
	if (fname == NULL)
		err(1, "malloc");

	sprintf(fname, "%s/newsyslog.%s.size", STATS_DIR, flog);

	/* ..if it doesn't exist, simply record the current size. */
	if ((sb.st_size == 0) || stat(fname, &tsb) < 0)
		goto update;

	fp = fopen(fname, "r");
	if (fp == NULL) {
		warn(fname);
		goto cleanup;
	}
#ifdef QUAD_OFF_T
	if (fscanf(fp, "%qd\n", &osize) != 1) {
#else
	if (fscanf(fp, "%ld\n", &osize) != 1) {
#endif	/* QUAD_OFF_T */
		fclose(fp);
		goto update;
	}

	fclose(fp);

	/* If the file is smaller, mark the entire thing as changed. */
	if (sb.st_size < osize)
		osize = 0;

	/* Now see if current size is larger. */
	if (sb.st_size > osize) {
		rb = (char *) malloc(sb.st_size - osize);
		if (rb == NULL)
			err(1, "malloc");

		/* Open logfile, seek. */
		fp = fopen(log, "r");
		if (fp == NULL) {
			warn(log);
			goto cleanup;
		}
		fseek(fp, osize, SEEK_SET);
		rd = fread(rb, 1, sb.st_size - osize, fp);
		if (rd < 1) {
			warn("fread");
			fclose(fp);
			goto cleanup;
		}
		
		/* Send message. */
		fclose(fp);

		fp = openmail();
		if (fp == NULL) {
			warn("openmail");
			goto cleanup;
		}
		fprintf(fp, "To: %s\nSubject: LOGFILE NOTIFICATION: %s\n\n\n",
		    whom, log);
		fwrite(rb, 1, rd, fp);
		fputs("\n\n", fp);

		closemail(fp);
	}
update:
	/* Reopen for writing and update file. */
	fp = fopen(fname, "w");
	if (fp == NULL) {
		warn(fname);
		goto cleanup;
	}
#ifdef QUAD_OFF_T
	fprintf(fp, "%qd\n", sb.st_size);
#else
	fprintf(fp, "%ld\n", sb.st_size);
#endif	/* QUAD_OFF_T */
	fclose(fp);

cleanup:
	free(flog);
	free(fname);
	if (rb != NULL)
		free(rb);
}

FILE *openmail()
{
	char *cmdbuf;
	FILE *ret;

	cmdbuf = (char *) malloc(strlen(SENDMAIL) + 3);
	if (cmdbuf == NULL)
		return(NULL);

	sprintf(cmdbuf, "%s -t", SENDMAIL);
	ret = popen(cmdbuf, "w");

	free(cmdbuf);
	return(ret);
}

void closemail(pfp)
	FILE *pfp;
{
	pclose(pfp);
}