1 files changed, 277 insertions, 0 deletions

diff --git a/lib/libc/gen/pututxline.c b/lib/libc/gen/pututxline.c
new file mode 100644
index 000000000000..8c2e91dd43fc
--- /dev/null
+++ b/lib/libc/gen/pututxline.c
@@ -0,0 +1,277 @@
+/*-
+ * Copyright (c) 2010 Ed Schouten <ed@FreeBSD.org>
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "namespace.h"
+#include <sys/endian.h>
+#include <sys/stat.h>
+#include <sys/uio.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <utmpx.h>
+#include "utxdb.h"
+#include "un-namespace.h"
+
+static FILE *
+futx_open(const char *file)
+{
+	int fd;
+	FILE *fp;
+	struct stat sb;
+
+	fd = _open(file, O_CREAT|O_RDWR|O_EXLOCK, 0644);
+	if (fd < 0)
+		return (NULL);
+
+	/* Safety check: never use broken files. */
+	if (_fstat(fd, &sb) != -1 && sb.st_size % sizeof(struct futx) != 0) {
+		_close(fd);
+		return (NULL);
+	}
+	
+	fp = fdopen(fd, "r+");
+	if (fp == NULL) {
+		_close(fd);
+		return (NULL);
+	}
+
+	return (fp);
+}
+
+static void
+utx_active_add(const struct futx *fu)
+{
+	FILE *fp;
+	struct futx fe;
+	off_t partial = -1;
+
+	/*
+	 * Register user login sessions.  Overwrite entries of sessions
+	 * that have already been terminated.
+	 */
+	fp = futx_open(_PATH_UTX_ACTIVE);
+	if (fp == NULL)
+		return;
+	while (fread(&fe, sizeof fe, 1, fp) == 1) {
+		switch (fe.fu_type) {
+		case USER_PROCESS:
+		case INIT_PROCESS:
+		case LOGIN_PROCESS:
+		case DEAD_PROCESS:
+			/* Overwrite when ut_id matches. */
+			if (memcmp(fu->fu_id, fe.fu_id, sizeof fe.fu_id) == 0) {
+				fseeko(fp, -sizeof fe, SEEK_CUR);
+				goto exact;
+			}
+			if (fe.fu_type != DEAD_PROCESS)
+				break;
+			/* FALLTHROUGH */
+		default:
+			/* Allow us to overwrite unused records. */
+			if (partial == -1)
+				partial = fseeko(fp, 0, SEEK_CUR) - sizeof fe;
+			break;
+		}
+	}
+	
+	/*
+	 * No exact match found.  Use the partial match.  If no partial
+	 * match was found, just append a new record.
+	 */
+	if (partial != -1)
+		fseeko(fp, partial, SEEK_SET);
+exact:
+	fwrite(fu, sizeof *fu, 1, fp);
+	fclose(fp);
+}
+
+static int
+utx_active_remove(struct futx *fu)
+{
+	FILE *fp;
+	struct futx fe;
+
+	/*
+	 * Remove user login sessions, having the same ut_id.
+	 */
+	fp = futx_open(_PATH_UTX_ACTIVE);
+	if (fp == NULL)
+		return (0);
+	while (fread(&fe, sizeof fe, 1, fp) == 1) {
+		switch (fe.fu_type) {
+		case USER_PROCESS:
+		case INIT_PROCESS:
+		case LOGIN_PROCESS:
+			if (memcmp(fu->fu_id, fe.fu_id, sizeof fe.fu_id) != 0)
+				continue;
+
+			/*
+			 * Prevent login sessions from having a negative
+			 * timespan.
+			 */
+			if (be64toh(fu->fu_tv) < be64toh(fe.fu_tv))
+				fu->fu_tv = fe.fu_tv;
+
+			/* Terminate session. */
+			fseeko(fp, -sizeof fe, SEEK_CUR);
+			fwrite(fu, sizeof *fu, 1, fp);
+			fclose(fp);
+			return (0);
+		}
+	}
+
+	fclose(fp);
+	return (1);
+}
+
+static void
+utx_active_purge(void)
+{
+
+	truncate(_PATH_UTX_ACTIVE, 0);
+}
+
+static void
+utx_lastlogin_add(const struct futx *fu)
+{
+	FILE *fp;
+	struct futx fe;
+
+	/*
+	 * Write an entry to lastlogin.  Overwrite the entry if the
+	 * current user already has an entry.  If not, append a new
+	 * entry.
+	 */
+	fp = futx_open(_PATH_UTX_LASTLOGIN);
+	if (fp == NULL)
+		return;
+	while (fread(&fe, sizeof fe, 1, fp) == 1) {
+		if (strncmp(fu->fu_user, fe.fu_user, sizeof fe.fu_user) != 0)
+			continue;
+
+		/* Prevent lowering the time value. */
+		if (be64toh(fu->fu_tv) <= be64toh(fe.fu_tv))
+			goto done;
+		
+		/* Found a previous lastlogin entry for this user. */
+		fseeko(fp, -sizeof fe, SEEK_CUR);
+		break;
+	}
+	fwrite(fu, sizeof *fu, 1, fp);
+done:
+	fclose(fp);
+}
+
+static void
+utx_lastlogin_upgrade(void)
+{
+	int fd;
+	struct stat sb;
+
+	fd = _open(_PATH_UTX_LASTLOGIN, O_RDWR, 0644);
+	if (fd < 0)
+		return;
+
+	/*
+	 * Truncate broken lastlogin files.  In the future we should
+	 * check for older versions of the file format here and try to
+	 * upgrade it.
+	 */
+	if (_fstat(fd, &sb) != -1 && sb.st_size % sizeof(struct futx) != 0)
+		ftruncate(fd, 0);
+	_close(fd);
+}
+
+static void
+utx_log_add(const struct futx *fu)
+{
+	int fd;
+	uint16_t l;
+	struct iovec vec[2];
+
+	/*
+	 * Append an entry to the log file.  We only need to append
+	 * records to this file, so to conserve space, trim any trailing
+	 * zero-bytes.  Prepend a length field, indicating the length of
+	 * the record, excluding the length field itself.
+	 */
+	for (l = sizeof *fu; l > 0 && ((const char *)fu)[l - 1] == '\0'; l--);
+	vec[0].iov_base = &l;
+	vec[0].iov_len = sizeof l;
+	vec[1].iov_base = __DECONST(void *, fu);
+	vec[1].iov_len = l;
+	l = htobe16(l);
+
+	fd = _open(_PATH_UTX_LOG, O_CREAT|O_WRONLY|O_APPEND, 0644);
+	if (fd < 0)
+		return;
+	_writev(fd, vec, 2);
+	_close(fd);
+}
+
+struct utmpx *
+pututxline(const struct utmpx *utmpx)
+{
+	struct futx fu;
+	static struct utmpx ut;
+
+	utx_to_futx(utmpx, &fu);
+	
+	switch (fu.fu_type) {
+	case BOOT_TIME:
+	case SHUTDOWN_TIME:
+		utx_active_purge();
+		utx_lastlogin_upgrade();
+		break;
+	case OLD_TIME:
+	case NEW_TIME:
+		break;
+	case USER_PROCESS:
+		utx_active_add(&fu);
+		utx_lastlogin_add(&fu);
+		break;
+#if 0 /* XXX: Are these records of any use to us? */
+	case INIT_PROCESS:
+	case LOGIN_PROCESS:
+		utx_active_add(&fu);
+		break;
+#endif
+	case DEAD_PROCESS:
+		if (utx_active_remove(&fu) != 0)
+			return (NULL);
+		break;
+	default:
+		return (NULL);
+	}
+
+	utx_log_add(&fu);
+	futx_to_utx(&fu, &ut);
+	return (&ut);
+}