Implement <utmpx.h>.

The utmpx interface is the standardized interface of the user accounting
database. The standard only defines a subset of the functions that were
present in System V-like systems.

I'd like to highlight some of the traits my implementation has:

- The standard allows the on-disk format to be different than the
  in-memory representation (struct utmpx). Most operating systems don't
  do this, but we do. This allows us to keep our ABI more stable, while
  giving us the opportunity to modify the on-disk format. It also allows
  us to use a common file format across different architectures (i.e.
  byte ordering).

- Our implementation of pututxline() also updates wtmp and lastlog (now
  called utx.log and utx.lastlogin). This means the databases are more
  likely to be in sync.

- Care must be taken that our implementation discard any fields that are
  not applicable. For example, our DEAD_PROCESS records do not hold a
  TTY name. Just a time stamp, a record identifier and a process
  identifier. It also guarantees that strings (ut_host, ut_line and
  ut_user) are null terminated. ut_id is obviously not null terminated,
  because it's not a string.

- The API and its behaviour should be conformant to POSIX, but there may
  be things that slightly deviate from the standard. This implementation
  uses separate file descriptors when writing to the log files. It also
  doesn't use getutxid() to search for a field to overwrite. It uses an
  allocation strategy similar to getutxid(), but prevents DEAD_PROCESS
  records from accumulating.

Make sure libulog doesn't overwrite the manpages shipped with our C
library. Also keep the symbol list in Symbol.map sorted.

I'll bump __FreeBSD_version later this evening. I first want to convert
everything to <utmpx.h> and get rid of <utmp.h>.

1 files changed, 61 insertions, 0 deletions

diff --git a/lib/libc/gen/utxdb.h b/lib/libc/gen/utxdb.h
new file mode 100644
index 0000000..ec02013
--- /dev/null
+++ b/lib/libc/gen/utxdb.h
@@ -0,0 +1,61 @@
+/*-
+ * 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.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _UTXDB_H_
+#define	_UTXDB_H_
+
+#include <stdint.h>
+
+#define	_PATH_UTX_ACTIVE	"/var/run/utx.active"
+#define	_PATH_UTX_LASTLOGIN	"/var/log/utx.lastlogin"
+#define	_PATH_UTX_LOG		"/var/log/utx.log"
+
+/*
+ * Entries in struct futx are ordered by how often they are used.  In
+ * utx.log only entries will be written until the last non-zero byte,
+ * which means we want to put the hostname at the end. Most primitive
+ * records only store a ut_type and ut_tv, which means we want to store
+ * those at the front.
+ */
+
+struct utmpx;
+
+struct futx {
+	uint8_t		fu_type;
+	uint64_t	fu_tv;
+	char		fu_id[8];
+	uint32_t	fu_pid;
+	char		fu_user[32];
+	char		fu_line[16];
+	char		fu_host[128];
+} __packed;
+
+void	utx_to_futx(const struct utmpx *, struct futx *);
+void	futx_to_utx(const struct futx *, struct utmpx *);
+
+#endif /* !_UTXDB_H_ */