usr/src/lib/libc/port/gen/getutx.c
changeset 0 68f95e015346
child 1111 e2bd9f81a79d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/usr/src/lib/libc/port/gen/getutx.c	Tue Jun 14 00:00:00 2005 -0700
@@ -0,0 +1,1407 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License").  You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/*	Copyright (c) 1988 AT&T	*/
+/*	  All Rights Reserved  	*/
+
+/*
+ * University Copyright- Copyright (c) 1982, 1986, 1988
+ * The Regents of the University of California
+ * All Rights Reserved
+ *
+ * University Acknowledgment- Portions of this document are derived from
+ * software developed by the University of California, Berkeley, and its
+ * contributors.
+ */
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+/*
+ * Routines to read and write the /etc/utmpx file. Also contains
+ * binary compatibility routines to support the old utmp interfaces
+ * on systems with MAXPID <= SHRT_MAX.
+ */
+
+#pragma weak getutxent = _getutxent
+#pragma weak getutent = _getutent
+#pragma weak getutxid = _getutxid
+#pragma weak getutid = _getutid
+#pragma weak getutxline = _getutxline
+#pragma weak getutline = _getutline
+#pragma weak getutmpx = _getutmpx
+#pragma weak getutmp = _getutmp
+#pragma weak makeutx = _makeutx
+#pragma weak makeut = _makeut
+#pragma weak modutx = _modutx
+#pragma weak modut = _modut
+#pragma weak pututxline = _pututxline
+#pragma weak pututline = _pututline
+#pragma weak setutxent = _setutxent
+#pragma weak setutent = _setutent
+#pragma weak endutxent = _endutxent
+#pragma weak endutent = _endutent
+#pragma weak utmpxname = _utmpxname
+#pragma weak utmpname = _utmpname
+#pragma weak updwtmpx = _updwtmpx
+#pragma weak updwtmp = _updwtmp
+
+#include "synonyms.h"
+#include <sys/types.h>
+#include <stdio.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <utmpx.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <strings.h>
+#include <unistd.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <limits.h>
+#include <signal.h>
+#include <spawn.h>
+
+#define	IDLEN		4	/* length of id field in utmp */
+#define	SC_WILDC	0xff	/* wild char for utmp ids */
+#define	MAXFILE		79	/* Maximum pathname length for "utmpx" file */
+
+#define	MAXVAL		255		/* max value for an id `character' */
+#define	IPIPE		"/etc/initpipe"	/* FIFO to send pids to init */
+#define	UPIPE		"/etc/utmppipe"	/* FIFO to send pids to utmpd */
+
+#define	VAR_UTMPX_FILE	"/var/adm/utmpx" /* for sanity check only */
+
+
+/*
+ * format of message sent to init
+ */
+
+typedef struct	pidrec {
+	int	pd_type;	/* command type */
+	pid_t	pd_pid;		/* pid */
+} pidrec_t;
+
+/*
+ * pd_type's
+ */
+#define	ADDPID 1	/* add a pid to "godchild" list */
+#define	REMPID 2	/* remove a pid to "godchild" list */
+
+static void	utmpx_frec2api(const struct futmpx *, struct utmpx *);
+static void	utmpx_api2frec(const struct utmpx *, struct futmpx *);
+
+static void	unlockutx(void);
+static void	sendpid(int, pid_t);
+static void	sendupid(int, pid_t);
+static int	idcmp(const char *, const char *);
+static int	allocid(char *, unsigned char *);
+static int	lockutx(void);
+
+static struct utmpx *invoke_utmp_update(const struct utmpx *);
+static struct futmpx *getoneutx(off_t *);
+static void	putoneutx(const struct utmpx *, off_t);
+static int	big_pids_in_use(void);
+
+/*
+ * prototypes for utmp compatibility routines (in getut.c)
+ */
+extern struct utmp *_compat_getutent(void);
+extern struct utmp *_compat_getutid(const struct utmp *);
+extern struct utmp *_compat_getutline(const struct utmp *);
+extern struct utmp *_compat_pututline(const struct utmp *);
+extern void _compat_setutent(void);
+extern void _compat_endutent(void);
+extern void _compat_updwtmp(const char *, struct utmp *);
+extern struct utmp *_compat_makeut(struct utmp *);
+
+static int fd = -1;	/* File descriptor for the utmpx file. */
+static int ut_got_maxpid = 0;	/* Flag set when sysconf(_SC_MAXPID) called */
+static pid_t ut_maxpid = 0;	/* Value of MAXPID from sysconf */
+static int tempfd = -1;  /* To store fd between lockutx() and unlockutx() */
+
+static	FILE	*fp = NULL;	/* Buffered file descriptior for utmpx file */
+static int changed_name = 0;	/* Flag set when not using utmpx file */
+static char utmpxfile[MAXFILE+1] = UTMPX_FILE;	/* Name of the current */
+char _compat_utmpfile[MAXFILE+1];
+static int compat_utmpflag = 0;	/* old compat mode flag */
+
+static struct futmpx fubuf;	/* Copy of last entry read in. */
+static struct utmpx ubuf;	/* Last entry returned to client */
+
+static struct utmp utmpcompat;	/* Buffer for returning utmp-format data */
+/*
+ * In the 64-bit world, the utmpx data structure grows because of
+ * the ut_time field (a struct timeval) grows in the middle of it.
+ */
+static void
+utmpx_frec2api(const struct futmpx *src, struct utmpx *dst)
+{
+	if (src == NULL)
+		return;
+
+	(void) strncpy(dst->ut_user, src->ut_user, sizeof (dst->ut_user));
+	(void) strncpy(dst->ut_line, src->ut_line, sizeof (dst->ut_line));
+	(void) memcpy(dst->ut_id, src->ut_id, sizeof (dst->ut_id));
+	dst->ut_pid = src->ut_pid;
+	dst->ut_type = src->ut_type;
+	dst->ut_exit.e_termination = src->ut_exit.e_termination;
+	dst->ut_exit.e_exit = src->ut_exit.e_exit;
+	dst->ut_tv.tv_sec = (time_t)src->ut_tv.tv_sec;
+	dst->ut_tv.tv_usec = (suseconds_t)src->ut_tv.tv_usec;
+	dst->ut_session = src->ut_session;
+	bzero(dst->pad, sizeof (dst->pad));
+	dst->ut_syslen = src->ut_syslen;
+	(void) memcpy(dst->ut_host, src->ut_host, sizeof (dst->ut_host));
+}
+
+static void
+utmpx_api2frec(const struct utmpx *src, struct futmpx *dst)
+{
+	if (src == NULL)
+		return;
+
+	(void) strncpy(dst->ut_user, src->ut_user, sizeof (dst->ut_user));
+	(void) strncpy(dst->ut_line, src->ut_line, sizeof (dst->ut_line));
+	(void) memcpy(dst->ut_id, src->ut_id, sizeof (dst->ut_id));
+	dst->ut_pid = src->ut_pid;
+	dst->ut_type = src->ut_type;
+	dst->ut_exit.e_termination = src->ut_exit.e_termination;
+	dst->ut_exit.e_exit = src->ut_exit.e_exit;
+	dst->ut_tv.tv_sec = (time32_t)src->ut_tv.tv_sec;
+	dst->ut_tv.tv_usec = (int32_t)src->ut_tv.tv_usec;
+	dst->ut_session = src->ut_session;
+	bzero(dst->pad, sizeof (dst->pad));
+	dst->ut_syslen = src->ut_syslen;
+	(void) memcpy(dst->ut_host, src->ut_host, sizeof (dst->ut_host));
+}
+
+/*
+ * "getutxent_frec" gets the raw version of the next entry in the utmpx file.
+ */
+static struct futmpx *
+getutxent_frec(void)
+{
+	/*
+	 * If the "utmpx" file is not open, attempt to open it for
+	 * reading.  If there is no file, attempt to create one.  If
+	 * both attempts fail, return NULL.  If the file exists, but
+	 * isn't readable and writeable, do not attempt to create.
+	 */
+	if (fd < 0) {
+
+		if ((fd = open(utmpxfile, O_RDWR|O_CREAT, 0644)) < 0) {
+
+			/*
+			 * If the open failed for permissions, try opening
+			 * it only for reading.  All "pututxline()" later
+			 * will fail the writes.
+			 */
+
+			if ((fd = open(utmpxfile, O_RDONLY)) < 0)
+				return (NULL);
+
+			if ((fp = fopen(utmpxfile, "r")) == NULL) {
+				(void) close(fd);
+				fd = -1;
+				return (NULL);
+			}
+
+		} else {
+			/*
+			 * Get the stream pointer
+			 */
+			if ((fp = fopen(utmpxfile, "r+")) == NULL) {
+				(void) close(fd);
+				fd = -1;
+				return (NULL);
+			}
+		}
+	}
+
+	/*
+	 * Try to read in the next entry from the utmpx file.
+	 */
+	if (fread(&fubuf, sizeof (fubuf), 1, fp) != 1) {
+		/*
+		 * Make sure fubuf is zeroed.
+		 */
+		bzero(&fubuf, sizeof (fubuf));
+		return (NULL);
+	}
+
+	return (&fubuf);
+}
+
+/*
+ * "big_pids_in_use" determines whether large pid numbers are in use
+ * or not.  If MAXPID won't fit in a signed short, the utmp.ut_pid
+ * field will overflow.
+ *
+ * Returns 0 if small pids are in use, 1 otherwise
+ */
+static int
+big_pids_in_use(void)
+{
+	if (!ut_got_maxpid) {
+		ut_got_maxpid++;
+		ut_maxpid = sysconf(_SC_MAXPID);
+	}
+	return (ut_maxpid > SHRT_MAX ? 1 : 0);
+}
+
+/*
+ * "getutxent" gets the next entry in the utmpx file.
+ */
+struct utmpx *
+getutxent(void)
+{
+	struct futmpx *futxp;
+
+	futxp = getutxent_frec();
+	utmpx_frec2api(&fubuf, &ubuf);
+	if (futxp == NULL)
+		return (NULL);
+	return (&ubuf);
+}
+/*
+ * "getutent" gets the next entry in the utmp file.
+ */
+struct utmp *
+getutent(void)
+{
+	struct utmpx *utmpx;
+
+	if (compat_utmpflag)
+		return (_compat_getutent());
+
+	/* fail if we can't represent maxpid properly */
+	if (big_pids_in_use()) {
+		errno = EOVERFLOW;
+		return (NULL);
+	}
+
+	if ((utmpx = getutxent()) == NULL)
+		return (NULL);
+
+	getutmp(utmpx, &utmpcompat);
+	return (&utmpcompat);
+}
+
+/*
+ * "getutxid" finds the specified entry in the utmpx file.  If
+ * it can't find it, it returns NULL.
+ */
+struct utmpx *
+getutxid(const struct utmpx *entry)
+{
+	short type;
+
+	/*
+	 * From XPG5: "The getutxid() or getutxline() may cache data.
+	 * For this reason, to use getutxline() to search for multiple
+	 * occurrences, it is necessary to zero out the static data after
+	 * each success, or getutxline() could just return a pointer to
+	 * the same utmpx structure over and over again."
+	 */
+	utmpx_api2frec(&ubuf, &fubuf);
+
+	/*
+	 * Start looking for entry. Look in our current buffer before
+	 * reading in new entries.
+	 */
+	do {
+		/*
+		 * If there is no entry in "fubuf", skip to the read.
+		 */
+		if (fubuf.ut_type != EMPTY) {
+			switch (entry->ut_type) {
+
+			/*
+			 * Do not look for an entry if the user sent
+			 * us an EMPTY entry.
+			 */
+			case EMPTY:
+				return (NULL);
+
+			/*
+			 * For RUN_LVL, BOOT_TIME, OLD_TIME, and NEW_TIME
+			 * entries, only the types have to match.  If they do,
+			 * return the address of internal buffer.
+			 */
+			case RUN_LVL:
+			case BOOT_TIME:
+			case DOWN_TIME:
+			case OLD_TIME:
+			case NEW_TIME:
+				if (entry->ut_type == fubuf.ut_type) {
+					utmpx_frec2api(&fubuf, &ubuf);
+					return (&ubuf);
+				}
+				break;
+
+			/*
+			 * For INIT_PROCESS, LOGIN_PROCESS, USER_PROCESS,
+			 * and DEAD_PROCESS the type of the entry in "fubuf",
+			 * must be one of the above and id's must match.
+			 */
+			case INIT_PROCESS:
+			case LOGIN_PROCESS:
+			case USER_PROCESS:
+			case DEAD_PROCESS:
+				if (((type = fubuf.ut_type) == INIT_PROCESS ||
+				    type == LOGIN_PROCESS ||
+				    type == USER_PROCESS ||
+				    type == DEAD_PROCESS) &&
+				    (fubuf.ut_id[0] == entry->ut_id[0]) &&
+				    (fubuf.ut_id[1] == entry->ut_id[1]) &&
+				    (fubuf.ut_id[2] == entry->ut_id[2]) &&
+				    (fubuf.ut_id[3] == entry->ut_id[3])) {
+					utmpx_frec2api(&fubuf, &ubuf);
+					return (&ubuf);
+				}
+				break;
+
+			/*
+			 * Do not search for illegal types of entry.
+			 */
+			default:
+				return (NULL);
+			}
+		}
+	} while (getutxent_frec() != NULL);
+
+	/*
+	 * Return NULL since the proper entry wasn't found.
+	 */
+	utmpx_frec2api(&fubuf, &ubuf);
+	return (NULL);
+}
+
+/*
+ * "getutid" finds the specified entry in the utmp file.  If
+ * it can't find it, it returns NULL.
+ */
+struct utmp *
+getutid(const struct utmp *entry)
+{
+	struct utmpx utmpx;
+	struct utmpx *utmpx2;
+
+	if (compat_utmpflag)
+		return (_compat_getutid(entry));
+
+	/* fail if we can't represent maxpid properly */
+	if (big_pids_in_use()) {
+		errno = EOVERFLOW;
+		return (NULL);
+	}
+	getutmpx(entry, &utmpx);
+	if ((utmpx2 = getutxid(&utmpx)) == NULL)
+		return (NULL);
+	getutmp(utmpx2, &utmpcompat);
+	return (&utmpcompat);
+}
+
+/*
+ * "getutxline" searches the "utmpx" file for a LOGIN_PROCESS or
+ * USER_PROCESS with the same "line" as the specified "entry".
+ */
+struct utmpx *
+getutxline(const struct utmpx *entry)
+{
+	/*
+	 * From XPG5: "The getutxid() or getutxline() may cache data.
+	 * For this reason, to use getutxline() to search for multiple
+	 * occurrences, it is necessary to zero out the static data after
+	 * each success, or getutxline() could just return a pointer to
+	 * the same utmpx structure over and over again."
+	 */
+	utmpx_api2frec(&ubuf, &fubuf);
+
+	do {
+		/*
+		 * If the current entry is the one we are interested in,
+		 * return a pointer to it.
+		 */
+		if (fubuf.ut_type != EMPTY &&
+		    (fubuf.ut_type == LOGIN_PROCESS ||
+		    fubuf.ut_type == USER_PROCESS) &&
+		    strncmp(&entry->ut_line[0], &fubuf.ut_line[0],
+		    sizeof (fubuf.ut_line)) == 0) {
+			utmpx_frec2api(&fubuf, &ubuf);
+			return (&ubuf);
+		}
+	} while (getutxent_frec() != NULL);
+
+	/*
+	 * Since entry wasn't found, return NULL.
+	 */
+	utmpx_frec2api(&fubuf, &ubuf);
+	return (NULL);
+}
+
+/*
+ * "getutline" searches the "utmp" file for a LOGIN_PROCESS or
+ * USER_PROCESS with the same "line" as the specified "entry".
+ */
+struct utmp *
+getutline(const struct utmp *entry)
+{
+	struct utmpx utmpx;
+	struct utmpx *utmpx2;
+
+	if (compat_utmpflag)
+		return (_compat_getutline(entry));
+
+	/* fail if we can't represent maxpid properly */
+	if (big_pids_in_use()) {
+		errno = EOVERFLOW;
+		return (NULL);
+	}
+	/* call getutxline */
+	getutmpx(entry, &utmpx);
+	if ((utmpx2 = getutxline(&utmpx)) == NULL)
+		return (NULL);
+	getutmp(utmpx2, &utmpcompat);
+	return (&utmpcompat);
+}
+
+/*
+ * invoke_utmp_update
+ *
+ * Invokes the utmp_update program which has the privilege to write
+ * to the /etc/utmp file.
+ */
+
+#define	UTMP_UPDATE 	"/usr/lib/utmp_update"
+#define	STRSZ	64	/* Size of char buffer for argument strings */
+
+static struct utmpx *
+invoke_utmp_update(const struct utmpx *entryx)
+{
+	extern char **environ;
+
+	int status;
+	pid_t child;
+	pid_t w;
+	int i;
+	char user[STRSZ], id[STRSZ], line[STRSZ], pid[STRSZ], type[STRSZ],
+	    term[STRSZ], exit[STRSZ], time[STRSZ], time_usec[STRSZ],
+	    session_id[STRSZ], syslen[32];
+	char pad[sizeof (entryx->pad) * 2 + 1];
+	char host[sizeof (entryx->ut_host) + 1];
+	struct utmpx *curx = NULL;
+	char bin2hex[] = "0123456789ABCDEF";
+	sigset_t mask, omask;
+	unsigned char *cp;
+	char *argvec[15];
+	int error;
+
+	/*
+	 * Convert the utmp struct to strings for command line arguments.
+	 */
+	(void) strncpy(user, entryx->ut_user, sizeof (entryx->ut_user));
+	user[sizeof (entryx->ut_user)] = '\0';
+	(void) strncpy(id, entryx->ut_id, sizeof (entryx->ut_id));
+	id[sizeof (entryx->ut_id)] = '\0';
+	(void) strncpy(line, entryx->ut_line, sizeof (entryx->ut_line));
+	line[sizeof (entryx->ut_line)] = '\0';
+	(void) sprintf(pid, "%d", entryx->ut_pid);
+	(void) sprintf(type, "%d", entryx->ut_type);
+	(void) sprintf(term, "%d", entryx->ut_exit.e_termination);
+	(void) sprintf(exit, "%d", entryx->ut_exit.e_exit);
+	(void) sprintf(time, "%ld", entryx->ut_tv.tv_sec);
+	(void) sprintf(time_usec, "%ld", entryx->ut_tv.tv_usec);
+	(void) sprintf(session_id, "%d", entryx->ut_session);
+
+	cp = (unsigned char *)entryx->pad;
+	for (i = 0; i < sizeof (entryx->pad); ++i) {
+		pad[i << 1] = bin2hex[(cp[i] >> 4) & 0xF];
+		pad[(i << 1) + 1] = bin2hex[cp[i] & 0xF];
+	}
+	pad[sizeof (pad) - 1] = '\0';
+
+	(void) sprintf(syslen, "%d", entryx->ut_syslen);
+	(void) strlcpy(host, entryx->ut_host, sizeof (host));
+
+	argvec[0] = UTMP_UPDATE;
+	argvec[1] = user;
+	argvec[2] = id;
+	argvec[3] = line;
+	argvec[4] = pid;
+	argvec[5] = type;
+	argvec[6] = term;
+	argvec[7] = exit;
+	argvec[8] = time;
+	argvec[9] = time_usec;
+	argvec[10] = session_id;
+	argvec[11] = pad;
+	argvec[12] = syslen;
+	argvec[13] = host;
+	argvec[14] = NULL;
+
+	/*
+	 * Block SIGCLD while we do this.
+	 * This avoids having an unexpected SIGCLD sent to the process.
+	 */
+	(void) sigemptyset(&mask);
+	(void) sigaddset(&mask, SIGCLD);
+	(void) sigprocmask(SIG_BLOCK, &mask, &omask);
+
+	error = posix_spawn(&child, UTMP_UPDATE, NULL, NULL, argvec, environ);
+	if (error) {
+		errno = error;
+		goto out;
+	}
+
+	do {
+		w = waitpid(child, &status, 0);
+	} while (w == -1 && errno == EINTR);
+
+	/*
+	 * We can get ECHILD if the process is ignoring SIGCLD.
+	 */
+	if (!(w == -1 && errno == ECHILD) &&
+	    (w == -1 || !WIFEXITED(status) || WEXITSTATUS(status) != 0)) {
+		/*
+		 * The child encountered an error,
+		 */
+		goto out;
+	}
+
+	/*
+	 * Normal termination.  Return a pointer to the entry we just made.
+	 */
+	setutxent();	/* Reset file pointer */
+
+	while ((curx = getutxent()) != NULL) {
+		if (curx->ut_type != EMPTY &&
+		    (curx->ut_type == LOGIN_PROCESS ||
+		    curx->ut_type == USER_PROCESS ||
+		    curx->ut_type == DEAD_PROCESS) &&
+		    strncmp(&entryx->ut_line[0], &curx->ut_line[0],
+		    sizeof (curx->ut_line)) == 0)
+			break;
+	}
+
+out:
+	(void) sigprocmask(SIG_SETMASK, &omask, NULL);
+	return (curx);
+}
+
+/*
+ * "pututxline" writes the structure sent into the utmpx file.
+ * If there is already an entry with the same id, then it is
+ * overwritten, otherwise a new entry is made at the end of the
+ * utmpx file.
+ */
+
+struct utmpx *
+pututxline(const struct utmpx *entry)
+{
+	struct utmpx *answer;
+	int lock = 0;
+	struct utmpx tmpxbuf;
+	struct futmpx ftmpxbuf;
+
+	/*
+	 * Copy the user supplied entry into our temporary buffer to
+	 * avoid the possibility that the user is actually passing us
+	 * the address of "ubuf".
+	 */
+	if (entry == NULL)
+		return (NULL);
+
+	tmpxbuf = *entry;
+	utmpx_api2frec(entry, &ftmpxbuf);
+
+	if (fd < 0) {
+		(void) getutxent_frec();
+		if (fd < 0)
+			return ((struct utmpx *)NULL);
+	}
+
+	/*
+	 * If we are not the superuser than we can't write to /etc/utmp,
+	 * so invoke update_utmp(8) to write the entry for us.
+	 */
+	if (changed_name == 0 && geteuid() != 0)
+		return (invoke_utmp_update(entry));
+
+	/*
+	 * Find the proper entry in the utmpx file.  Start at the current
+	 * location.  If it isn't found from here to the end of the
+	 * file, then reset to the beginning of the file and try again.
+	 * If it still isn't found, then write a new entry at the end of
+	 * the file.  (Making sure the location is an integral number of
+	 * utmp structures into the file incase the file is scribbled.)
+	 */
+
+	if (getutxid(&tmpxbuf) == NULL) {
+
+		setutxent();
+
+		/*
+		 * Lock the the entire file from here onwards.
+		 */
+		if (getutxid(&tmpxbuf) == NULL) {
+			lock++;
+			if (lockf(fd, F_LOCK, 0) < NULL)
+				return (NULL);
+			(void) fseek(fp, 0, SEEK_END);
+		} else
+			(void) fseek(fp, -(long)sizeof (struct futmpx),
+			    SEEK_CUR);
+	} else
+		(void) fseek(fp, -(long)sizeof (struct futmpx), SEEK_CUR);
+
+	/*
+	 * Write out the user supplied structure.  If the write fails,
+	 * then the user probably doesn't have permission to write the
+	 * utmpx file.
+	 */
+	if (fwrite(&ftmpxbuf, sizeof (ftmpxbuf), 1, fp) != 1) {
+		answer = (struct utmpx *)NULL;
+	} else {
+		/*
+		 * Save the new user structure into ubuf and fubuf so that
+		 * it will be up to date in the future.
+		 */
+		(void) fflush(fp);
+		fubuf = ftmpxbuf;
+		utmpx_frec2api(&fubuf, &ubuf);
+		answer = &ubuf;
+	}
+
+	if (lock)
+		(void) lockf(fd, F_ULOCK, 0);
+
+	if (answer != NULL && (tmpxbuf.ut_type == USER_PROCESS ||
+	    tmpxbuf.ut_type == DEAD_PROCESS))
+		sendupid(tmpxbuf.ut_type == USER_PROCESS ? ADDPID : REMPID,
+		    (pid_t)tmpxbuf.ut_pid);
+	return (answer);
+}
+/*
+ * "pututline" is a wrapper that calls pututxline after converting
+ * the utmp record to a utmpx record.
+ */
+struct utmp *
+pututline(const struct utmp *entry)
+{
+	struct utmpx utmpx;
+	struct utmpx *utmpx2;
+
+	if (compat_utmpflag)
+		return (_compat_pututline(entry));
+
+	getutmpx(entry, &utmpx);
+	if ((utmpx2 = pututxline(&utmpx)) == NULL)
+		return (NULL);
+	getutmp(utmpx2, &utmpcompat);
+	return (&utmpcompat);
+}
+
+/*
+ * "setutxent" just resets the utmpx file back to the beginning.
+ */
+void
+setutxent(void)
+{
+	if (fd != -1)
+		(void) lseek(fd, 0L, SEEK_SET);
+
+	if (fp != NULL)
+		(void) fseek(fp, 0L, SEEK_SET);
+
+	/*
+	 * Zero the stored copy of the last entry read, since we are
+	 * resetting to the beginning of the file.
+	 */
+	bzero(&ubuf, sizeof (ubuf));
+	bzero(&fubuf, sizeof (fubuf));
+}
+
+/*
+ * "setutent" is a wrapper that calls setutxent
+ */
+void
+setutent(void)
+{
+	if (compat_utmpflag) {
+		_compat_setutent();
+		return;
+	}
+
+	setutxent();
+}
+
+/*
+ * "endutxent" closes the utmpx file.
+ */
+void
+endutxent(void)
+{
+	if (fd != -1)
+		(void) close(fd);
+	fd = -1;
+
+	if (fp != NULL)
+		(void) fclose(fp);
+	fp = NULL;
+
+	bzero(&ubuf, sizeof (ubuf));
+	bzero(&fubuf, sizeof (fubuf));
+}
+
+/*
+ * "endutent" is a wrapper that calls endutxent
+ * and clears the utmp compatibility buffer.
+ */
+void
+endutent(void)
+{
+	if (compat_utmpflag) {
+		_compat_endutent();
+		return;
+	}
+
+	endutxent();
+	bzero(&utmpcompat, sizeof (utmpcompat));
+}
+
+/*
+ * "utmpxname" allows the user to read a file other than the
+ * normal "utmpx" file.
+ */
+int
+utmpxname(const char *newfile)
+{
+	size_t len;
+
+	/*
+	 * Determine if the new filename will fit.  If not, return 0.
+	 */
+	if ((len = strlen(newfile)) > MAXFILE-1)
+		return (0);
+
+	/*
+	 * The name of the utmpx file has to end with 'x'
+	 */
+	if (newfile[len-1] != 'x')
+		return (0);
+
+	/*
+	 * Otherwise copy in the new file name.
+	 */
+	else
+		(void) strcpy(&utmpxfile[0], newfile);
+	/*
+	 * Make sure everything is reset to the beginning state.
+	 */
+	endutxent();
+
+	/*
+	 * If the file is being changed to /etc/utmpx or /var/adm/utmpx then
+	 * we clear the flag so pututxline invokes utmp_update.  Otherwise
+	 * we set the flag indicating that they changed to another name.
+	 */
+	if (strcmp(utmpxfile, UTMPX_FILE) == 0 ||
+	    strcmp(utmpxfile, VAR_UTMPX_FILE) == 0)
+		changed_name = 0;
+	else
+		changed_name = 1;
+
+	return (1);
+}
+
+/*
+ * "utmpname" allows the user to read a file other than the
+ * normal "utmp" file. If the file specified is "/var/adm/utmp"
+ * or "/var/adm/wtmp", it is translated to the corresponding "utmpx"
+ * format name, and all "utmp" operations become wrapped calls
+ * to the equivalent "utmpx" routines, with data conversions
+ * as appropriate.  In the event the application wishes to read
+ * an actual "old" utmp file (named something other than /var/adm/utmp),
+ * calling this function with that name enables backward compatibility
+ * mode, where we actually call the old utmp routines to operate on
+ * the old file.
+ */
+int
+utmpname(const char *newfile)
+{
+	char name[MAXFILE+1];
+
+	if (strlen(newfile) > MAXFILE)
+		return (0);
+
+	if (strcmp(newfile, "/var/adm/utmp") == 0 ||
+	    strcmp(newfile, "/var/adm/wtmp") == 0) {
+		(void) strcpy(name, newfile);
+		(void) strcat(name, "x");
+		compat_utmpflag = 0;	/* turn off old compat mode */
+		return (utmpxname(name));
+	} else {
+		(void) strcpy(_compat_utmpfile, newfile);
+		compat_utmpflag = 1;
+		return (1);
+	}
+}
+
+/*
+ * Add the record to wtmpx.
+ */
+void
+updwtmpx(const char *filex, struct utmpx *utx)
+{
+	struct futmpx futx;
+	int wfdx;
+
+	if ((wfdx = open(filex, O_WRONLY | O_APPEND)) < 0)
+		return;
+
+	(void) lseek(wfdx, 0, SEEK_END);
+
+	utmpx_api2frec(utx, &futx);
+	(void) write(wfdx, &futx, sizeof (futx));
+
+done:
+	(void) close(wfdx);
+}
+
+/*
+ * Add record to wtmp (actually wtmpx). If not updating /var/adm/wtmp,
+ * use the old utmp compatibility routine to write a utmp-format
+ * record to the file specified.
+ */
+void
+updwtmp(const char *file, struct utmp *ut)
+{
+	struct utmpx utmpx;
+	char xfile[MAXFILE + 1];
+
+	if (strcmp(file, "/var/adm/wtmp") == 0) {
+		(void) strlcpy(xfile, file, sizeof (xfile) - 1);
+		(void) strcat(xfile, "x");
+		getutmpx(ut, &utmpx);
+		updwtmpx((const char *)&xfile, &utmpx);
+	} else
+		_compat_updwtmp(file, ut);
+}
+
+/*
+ * modutx - modify a utmpx entry.  Also notify init about new pids or
+ *	old pids that it no longer needs to care about
+ *
+ *	args:	utp- point to utmpx structure to be created
+ */
+struct utmpx *
+modutx(const struct utmpx *utp)
+{
+	int i;
+	struct utmpx utmp;		/* holding area */
+	struct utmpx *ucp = &utmp;	/* and a pointer to it */
+	struct utmpx *up;		/* "current" utmpx entry */
+	struct futmpx *fup;		/* being examined */
+
+	for (i = 0; i < IDLEN; ++i) {
+		if ((unsigned char)utp->ut_id[i] == SC_WILDC)
+			return (NULL);
+	}
+
+	/*
+	 * copy the supplied utmpx structure someplace safe
+	 */
+	utmp = *utp;
+	setutxent();
+	while (fup = getutxent_frec()) {
+		if (idcmp(ucp->ut_id, fup->ut_id))
+			continue;
+
+		/*
+		 * only get here if ids are the same, i.e. found right entry
+		 */
+		if (ucp->ut_pid != fup->ut_pid) {
+			sendpid(REMPID, (pid_t)fup->ut_pid);
+			sendpid(ADDPID, (pid_t)ucp->ut_pid);
+		}
+		break;
+	}
+	up = pututxline(ucp);
+	if (ucp->ut_type == DEAD_PROCESS)
+		sendpid(REMPID, (pid_t)ucp->ut_pid);
+	if (up)
+		updwtmpx(WTMPX_FILE, up);
+	endutxent();
+	return (up);
+}
+
+/*
+ * modut - modify a utmp entry.	 Also notify init about new pids or
+ *	old pids that it no longer needs to care about
+ *
+ *	args:	utmp - point to utmp structure to be created
+ */
+struct utmp *
+modut(struct utmp *utp)
+{
+	struct utmpx utmpx;
+	struct utmpx *utmpx2;
+
+	getutmpx(utp, &utmpx);
+	if ((utmpx2 = modutx(&utmpx)) == NULL)
+		return (NULL);
+
+	getutmp(utmpx2, utp);
+	return (utp);
+}
+
+/*
+ * idcmp - compare two id strings, return  0 if same, non-zero if not *
+ *	args:	s1 - first id string
+ *		s2 - second id string
+ */
+static int
+idcmp(const char *s1, const char *s2)
+{
+	int i;
+
+	for (i = 0; i < IDLEN; ++i)
+		if ((unsigned char) *s1 != SC_WILDC && (*s1++ != *s2++))
+			return (-1);
+	return (0);
+}
+
+
+/*
+ * allocid - allocate an unused id for utmp, either by recycling a
+ *	DEAD_PROCESS entry or creating a new one.  This routine only
+ *	gets called if a wild card character was specified.
+ *
+ *	args:	srcid - pattern for new id
+ *		saveid - last id matching pattern for a non-dead process
+ */
+static int
+allocid(char *srcid, unsigned char *saveid)
+{
+	int i;		/* scratch variable */
+	int changed;		/* flag to indicate that a new id has */
+				/* been generated */
+	char copyid[IDLEN];	/* work area */
+
+	(void) memcpy(copyid, srcid, IDLEN);
+	changed = 0;
+	for (i = 0; i < IDLEN; ++i) {
+
+		/*
+		 * if this character isn't wild, it'll be part of the
+		 * generated id
+		 */
+		if ((unsigned char) copyid[i] != SC_WILDC)
+			continue;
+
+		/*
+		 * it's a wild character, retrieve the character from the
+		 * saved id
+		 */
+		copyid[i] = saveid[i];
+
+		/*
+		 * if we haven't changed anything yet, try to find a new char
+		 * to use
+		 */
+		if (!changed && (saveid[i] < MAXVAL)) {
+
+		/*
+		 * Note: this algorithm is taking the "last matched" id
+		 * and trying to make a 1 character change to it to create
+		 * a new one.  Rather than special-case the first time
+		 * (when no perturbation is really necessary), just don't
+		 * allocate the first valid id.
+		 */
+
+			while (++saveid[i] < MAXVAL) {
+				/*
+				 * make sure new char is alphanumeric
+				 */
+				if (isalnum(saveid[i])) {
+					copyid[i] = saveid[i];
+					changed = 1;
+					break;
+				}
+			}
+
+			if (!changed) {
+				/*
+				 * Then 'reset' the current count at
+				 * this position to it's lowest valid
+				 * value, and propagate the carry to
+				 * the next wild-card slot
+				 *
+				 * See 1113208.
+				 */
+				saveid[i] = 0;
+				while (!isalnum(saveid[i]))
+				saveid[i]++;
+				copyid[i] = ++saveid[i];
+			}
+		}
+	}
+	/*
+	 * changed is true if we were successful in allocating an id
+	 */
+	if (changed) {
+		(void) memcpy(srcid, copyid, IDLEN);
+		return (0);
+	} else {
+		return (-1);
+	}
+}
+
+
+/*
+ * lockutx - lock utmpx file
+ */
+static int
+lockutx(void)
+{
+	int lockfd;
+
+	if ((lockfd = open(UTMPX_FILE, O_RDWR|O_CREAT, 0644)) < 0)
+		return (-1);
+
+	if (lockf(lockfd, F_LOCK, 0) < 0) {
+		(void) close(lockfd);
+		return (-1);
+	}
+
+	tempfd = fd;
+	fd = lockfd;
+
+	return (0);
+
+}
+
+
+
+/*
+ * unlockutx - unlock utmpx file
+ */
+static void
+unlockutx(void)
+{
+	(void) lockf(fd, F_ULOCK, 0);
+	(void) close(fd);
+	fd = tempfd;
+}
+
+
+/*
+ * sendpid - send message to init to add or remove a pid from the
+ *	"godchild" list
+ *
+ *	args:	cmd - ADDPID or REMPID
+ *		pid - pid of "godchild"
+ */
+static void
+sendpid(int cmd, pid_t pid)
+{
+	int pfd;		/* file desc. for init pipe */
+	pidrec_t prec;		/* place for message to be built */
+
+	/*
+	 * if for some reason init didn't open initpipe, open it read/write
+	 * here to avoid sending SIGPIPE to the calling process
+	 */
+	pfd = open(IPIPE, O_RDWR);
+	if (pfd < 0)
+		return;
+	prec.pd_pid = pid;
+	prec.pd_type = cmd;
+	(void) write(pfd, &prec, sizeof (pidrec_t));
+	(void) close(pfd);
+}
+
+/*
+ * makeutx - create a utmpx entry, recycling an id if a wild card is
+ *	specified.  Also notify init about the new pid
+ *
+ *	args:	utmpx - point to utmpx structure to be created
+ */
+
+struct utmpx *
+makeutx(const struct utmpx *utmp)
+{
+	struct utmpx *utp;
+	struct futmpx *ut;		/* "current" utmpx being examined */
+	unsigned char saveid[IDLEN];	/* the last id we matched that was */
+					/* NOT a dead proc */
+	int falphanum = 0x30;		/* first alpha num char */
+	off_t offset;
+
+	/*
+	 * Are any wild card char's present in the idlen string?
+	 */
+	if (memchr(utmp->ut_id, SC_WILDC, IDLEN) != NULL) {
+		/*
+		 * try to lock the utmpx file, only needed if
+		 * we're doing wildcard matching
+		 */
+		if (lockutx())
+			return (NULL);
+
+		/*
+		 * used in allocid
+		 */
+		(void) memset(saveid, falphanum, IDLEN);
+
+		while (ut = getoneutx(&offset))
+			if (idcmp(utmp->ut_id, ut->ut_id)) {
+				continue;
+			} else {
+				/*
+				 * Found a match. We are done if this is
+				 * a free slot. Else record this id. We
+				 * will need it to generate the next new id.
+				 */
+				if (ut->ut_type == DEAD_PROCESS)
+					break;
+				else
+					(void) memcpy(saveid, ut->ut_id,
+					    IDLEN);
+			}
+
+		if (ut) {
+
+			/*
+			 * Unused entry, reuse it. We know the offset. So
+			 * just go to that offset  utmpx and write it out.
+			 */
+			(void) memcpy((caddr_t)utmp->ut_id, ut->ut_id, IDLEN);
+
+			putoneutx(utmp, offset);
+			updwtmpx(WTMPX_FILE, (struct utmpx *)utmp);
+			unlockutx();
+			sendpid(ADDPID, (pid_t)utmp->ut_pid);
+			return ((struct utmpx *)utmp);
+		} else {
+			/*
+			 * nothing available, allocate an id and
+			 * write it out at the end.
+			 */
+
+			if (allocid((char *)utmp->ut_id, saveid)) {
+				unlockutx();
+				return (NULL);
+			} else {
+				/*
+				 * Seek to end and write out the entry
+				 * and also update the utmpx file.
+				 */
+				(void) lseek(fd, 0L, SEEK_END);
+				offset = lseek(fd, 0L, SEEK_CUR);
+
+				putoneutx(utmp, offset);
+				updwtmpx(WTMPX_FILE, (struct utmpx *)utmp);
+				unlockutx();
+				sendpid(ADDPID, (pid_t)utmp->ut_pid);
+				return ((struct utmpx *)utmp);
+			}
+		}
+	} else {
+		utp = pututxline(utmp);
+		if (utp)
+			updwtmpx(WTMPX_FILE, utp);
+		endutxent();
+		sendpid(ADDPID, (pid_t)utmp->ut_pid);
+		return (utp);
+	}
+}
+
+/*
+ * makeut - create a utmp entry, recycling an id if a wild card is
+ *	specified.  Also notify init about the new pid
+ *
+ *	args:	utmp - point to utmp structure to be created
+ */
+struct utmp *
+makeut(struct utmp *utmp)
+{
+	struct utmpx utmpx;
+	struct utmpx *utmpx2;
+
+	if (compat_utmpflag)
+		return (_compat_makeut(utmp));
+
+	getutmpx(utmp, &utmpx);
+	if ((utmpx2 = makeutx(&utmpx)) == NULL)
+		return (NULL);
+
+	getutmp(utmpx2, utmp);
+	return (utmp);
+}
+
+
+#define	UTMPNBUF	200	/* Approx 8k (FS Block) size */
+static struct futmpx	*utmpbuf = NULL;
+
+/*
+ * Buffered read routine to get one entry from utmpx file
+ */
+static struct futmpx *
+getoneutx(off_t *off)
+{
+	static	size_t idx = 0;	/* Current index in the utmpbuf */
+	static	size_t nidx = 0;	/* Max entries in this utmpbuf */
+	static	int nbuf = 0;	/* number of utmpbufs read from disk */
+	ssize_t	nbytes, bufsz = sizeof (struct futmpx) * UTMPNBUF;
+
+	if (utmpbuf == NULL)
+		if ((utmpbuf = malloc(bufsz)) == NULL) {
+			perror("malloc");
+			return (NULL);
+		}
+
+	if (idx == nidx) {
+		/*
+		 *	We have read all entries in the utmpbuf. Read
+		 *	the buffer from the disk.
+		 */
+		if ((nbytes = read(fd, utmpbuf, bufsz)) < bufsz) {
+			/*
+			 *	Partial read only. keep count of the
+			 *	number of valid entries in the buffer
+			 */
+			nidx = nbytes / sizeof (struct futmpx);
+		} else {
+			/*
+			 *	We read in the full UTMPNBUF entries
+			 *	Great !
+			 */
+			nidx = UTMPNBUF;
+		}
+		nbuf++;		/* Number of buf we have read in. */
+		idx = 0;	/* reset index within utmpbuf */
+	}
+
+	/*
+	 *	Current offset of this buffer in the file
+	 */
+	*off = (((nbuf - 1) * UTMPNBUF) + idx) * sizeof (struct futmpx);
+
+	if (idx < nidx) {
+		/*
+		 *	We still have at least one valid buffer in
+		 *	utmpbuf to be passed to the caller.
+		 */
+		return (&utmpbuf[idx++]);
+	}
+
+	/*
+	 *	Reached EOF. Return NULL. Offset is set correctly
+	 *	to append at the end of the file
+	 */
+
+	return (NULL);
+}
+
+static void
+putoneutx(const struct utmpx *utpx, off_t off)
+{
+	struct	futmpx futx;
+
+	utmpx_api2frec(utpx, &futx);
+	(void) lseek(fd, off, SEEK_SET);	/* seek in the utmpx file */
+	(void) write(fd, &futx, sizeof (futx));
+}
+
+/*
+ * sendupid - send message to utmpd to add or remove a pid from the
+ *	list of procs to watch
+ *
+ *	args:	cmd - ADDPID or REMPID
+ *		pid - process ID of process to watch
+ */
+static void
+sendupid(int cmd, pid_t pid)
+{
+	int pfd;		/* file desc. for utmp pipe */
+	pidrec_t prec;		/* place for message to be built */
+
+	/*
+	 * if for some reason utmp didn't open utmppipe, open it read/write
+	 * here to avoid sending SIGPIPE to the calling process
+	 */
+
+	pfd = open(UPIPE, O_RDWR | O_NONBLOCK | O_NDELAY);
+	if (pfd < 0)
+		return;
+	prec.pd_pid = pid;
+	prec.pd_type = cmd;
+	(void) write(pfd, &prec, sizeof (pidrec_t));
+	(void) close(pfd);
+}
+
+/*
+ * getutmpx - convert a utmp record into a utmpx record
+ */
+void
+getutmpx(const struct utmp *ut, struct utmpx *utx)
+{
+	(void) memcpy(utx->ut_user, ut->ut_user, sizeof (ut->ut_user));
+	(void) bzero(&utx->ut_user[sizeof (ut->ut_user)],
+	    sizeof (utx->ut_user) - sizeof (ut->ut_user));
+	(void) memcpy(utx->ut_line, ut->ut_line, sizeof (ut->ut_line));
+	(void) bzero(&utx->ut_line[sizeof (ut->ut_line)],
+	    sizeof (utx->ut_line) - sizeof (ut->ut_line));
+	(void) memcpy(utx->ut_id, ut->ut_id, sizeof (ut->ut_id));
+	utx->ut_pid = ut->ut_pid;
+	utx->ut_type = ut->ut_type;
+	utx->ut_exit = ut->ut_exit;
+	utx->ut_tv.tv_sec = ut->ut_time;
+	utx->ut_tv.tv_usec = 0;
+	utx->ut_session = 0;
+	bzero(utx->pad, sizeof (utx->pad));
+	bzero(utx->ut_host, sizeof (utx->ut_host));
+	utx->ut_syslen = 0;
+}
+
+/*
+ * getutmp - convert a utmpx record into a utmp record
+ */
+void
+getutmp(const struct utmpx *utx, struct utmp *ut)
+{
+	(void) memcpy(ut->ut_user, utx->ut_user, sizeof (ut->ut_user));
+	(void) memcpy(ut->ut_line, utx->ut_line, sizeof (ut->ut_line));
+	(void) memcpy(ut->ut_id, utx->ut_id, sizeof (utx->ut_id));
+	ut->ut_pid = utx->ut_pid;
+	ut->ut_type = utx->ut_type;
+	ut->ut_exit = utx->ut_exit;
+	ut->ut_time = utx->ut_tv.tv_sec;
+}