Clean up the wtmp mess

4 files changed, 29 insertions, 23 deletions

diff --git a/doc/overview.html b/doc/overview.html
index 71b852d..ef01e1e 100644
--- a/doc/overview.html
+++ b/doc/overview.html
@@ -129,8 +129,8 @@ command is executed. </li>
 utmp record cleanup duty for patched <tt>login</tt> programs. </li>
    <li> <tt>s6-linux-init-early-getty</tt>: the early getty,
 allowing the user to login even if <em>rc.init</em> fails early. </li>
-   <li> <tt>utmpd</tt> and <tt>wtmpd</tt>: the services performing
-utmp and wtmp access when <a href="//skarnet.org/software/utmps/">utmps</a> is
+   <li> <tt>utmpd</tt>: a service performing
+utmp access when <a href="//skarnet.org/software/utmps/">utmps</a> is
 used. </li>
   </ul> </li>
 </ul>
diff --git a/doc/s6-linux-init-maker.html b/doc/s6-linux-init-maker.html
index f8ef940..9bf44ac 100644
--- a/doc/s6-linux-init-maker.html
+++ b/doc/s6-linux-init-maker.html
@@ -320,9 +320,15 @@ files in a staging directory. </li> <br />
 available when the s6-linux-init package has been built with the
 <tt>--enable-utmps</tt> configure option, that enables support for the
 <a href="//skarnet.org/software/utmps/">utmps</a> package. The option
-defines the user that the <tt>utmpd</tt> and <tt>wtmpd</tt> services
-will run as, and activates these services. Default is <strong>no
-utmpd or wtmpd services</strong>. </li> <br />
+defines the user that the <tt>utmpd</tt> service
+will run as, and activates this service. (Note that you will still
+have to create a <tt>wtmpd</tt> service yourself and activate it
+later in the boot sequence, after a writable filesystem is mounted,
+because the wtmp database is supposed to be persistent and should live
+on a real filesystem.
+s6-linux-init cannot do that for you, because it only handles the
+early part of the boot sequence, before filesystems are mounted.)
+Default is <strong>no utmpd service</strong>. </li> <br />
 
  <li> <tt>-C</tt>&nbsp;: create a set of scripts that is suitable
 for running <em>in a container</em>. This modifies some behaviours:
@@ -457,11 +463,14 @@ directories may exist:
 
 <ul>
  <li> A directory somewhere under <tt>run-image</tt>, by default <tt>utmps</tt>,
-that is the location where the utmp and wtmp files will be created. </li>
- <li> Two additional early services named <tt>utmpd</tt> and <tt>wtmpd</tt>,
-that are the <a href="//skarnet.org/software/utmps/">utmps</a> way of
-providing secure utmp functionality. </li>
-</ul>
+that is the location where the utmp files will be created. </li>
+ <li> An additional early service named <tt>utmpd</tt>, which is
+a part of the <a href="//skarnet.org/software/utmps/">utmps</a> way of
+providing secure utmp functionality. A similar <tt>wtmpd</tt> service
+should also be created and run later in the boot sequence by the
+service manager; it is not s6-linux-init's job to do it because
+<tt>wtmp</tt> requires a real, writable filesystem. </li>
+</ul>1
 
 <h2> Notes </h2>
 
diff --git a/src/init/s6-linux-init-maker.c b/src/init/s6-linux-init-maker.c
index 6d86ff9..c505e04 100644
--- a/src/init/s6-linux-init-maker.c
+++ b/src/init/s6-linux-init-maker.c
@@ -499,7 +499,7 @@ static inline void auto_basedir (char const *base, char const *dir, uid_t uid, g
   }
 }
 
-static int utmpd_script (buffer *b, char const *uw)
+static int utmpd_script (buffer *b, char const *aux)
 {
   size_t sabase = satmp.len ;
   if (!put_shebang(b)
@@ -512,12 +512,9 @@ static int utmpd_script (buffer *b, char const *uw)
   if (buffer_puts(b, "\n"
     EXECLINE_EXTBINPREFIX "cd " S6_LINUX_INIT_TMPFS "/" UTMPS_DIR "\n"
     EXECLINE_EXTBINPREFIX "fdmove 1 3\n"
-    S6_EXTBINPREFIX "s6-ipcserver -1 -c 1000 -- ") < 0) return 0 ;
-  if (buffer_puts(b, uw[0] == 'u' ? UTMPS_UTMPD_PATH : UTMPS_WTMPD_PATH) < 0
-   || buffer_puts(b, "\n"
-    UTMPS_EXTBINPREFIX "utmps-") < 0
-   || buffer_puts(b, uw) < 0
-   || buffer_puts(b, "tmpd\n") < 0) return 0 ;
+    S6_EXTBINPREFIX "s6-ipcserver -1 -c 1000 -- " UTMPS_UTMPD_PATH "\n"
+    UTMPS_EXTBINPREFIX "utmps-utmpd") < 0) return 0 ;
+  (void)aux ;
   return 1 ;
 
  err:
@@ -529,17 +526,13 @@ static inline void make_utmps (char const *base)
 {
   auto_dir(base, "run-image/" SCANDIR "/utmpd", 0, 0, 0755) ;
   auto_file(base, "run-image/" SCANDIR "/utmpd/notification-fd", "3\n", 2) ;
-  auto_script(base, "run-image/" SCANDIR "/utmpd/run", &utmpd_script, "u") ;
-  auto_dir(base, "run-image/" SCANDIR "/wtmpd", 0, 0, 0755) ;
-  auto_file(base, "run-image/" SCANDIR "/wtmpd/notification-fd", "3\n", 2) ;
-  auto_script(base, "run-image/" SCANDIR "/wtmpd/run", &utmpd_script, "w") ;
+  auto_script(base, "run-image/" SCANDIR "/utmpd/run", &utmpd_script, 0) ;
   {
     uid_t uid ;
     gid_t gid ;
     getug(base, utmp_user, &uid, &gid) ;
     auto_dir(base, "run-image/" UTMPS_DIR, uid, gid, 0755) ;
     auto_basedir(base, "run-image/" S6_LINUX_INIT_UTMPD_PATH, uid, gid, 0755) ;
-    auto_basedir(base, "run-image/" S6_LINUX_INIT_WTMPD_PATH, uid, gid, 0755) ;
   }
 }
 
diff --git a/src/shutdown/s6-linux-init-hpr.c b/src/shutdown/s6-linux-init-hpr.c
index 8ebe2d5..a874ac3 100644
--- a/src/shutdown/s6-linux-init-hpr.c
+++ b/src/shutdown/s6-linux-init-hpr.c
@@ -26,7 +26,11 @@
 #endif
 
 #ifndef _PATH_WTMP
-#define _PATH_WTMP "/dev/null/wtmp"
+# ifdef WTMPX_FILE
+#  define _PATH_WTMP WTMPX_FILE
+# else
+#  define _PATH_WTMP "/var/log/wtmp"
+# endif
 #endif
 
 #define USAGE "s6-linux-init-hpr [ -h | -p | -r ] [ -n ] [ -d | -w ] [ -W ] [ -f ] [ -i ]"