Make `-n` default to `/var/run` unless overridden by configure(1)

Renovate `-n` and `-a` manual page descriptions

Fixes: #3672

INSTALL

@@ -8,7 +8,7 @@ afterwards in order to update the shared library cache.
 If you obtained the sources directly from the Git repository, you will
 need to run autogen.sh first to create the configure script.
 
-Varnish will store run-time state in $localstatedir/varnish; you may
+Varnish will store run-time state in /var/run/varnish; you may
 want to tune this using configure's --localstatedir parameter.
 
 Additional configure options of interest:

configure.ac

@@ -654,7 +654,11 @@ fi
 LIBS="${save_LIBS}"
 
 # Run-time directory
-VARNISH_STATE_DIR='${localstatedir}/varnish'
+if test "${localstatedir}" = '${prefix}/var' ; then
+   VARNISH_STATE_DIR='/var/run'
+else
+   VARNISH_STATE_DIR='${localstatedir}/varnish'
+fi
 AC_SUBST(VARNISH_STATE_DIR)
 
 # Default configuration directory.

doc/sphinx/reference/varnishd.rst

@@ -20,7 +20,29 @@ HTTP accelerator daemon
 SYNOPSIS
 ========
 
-varnishd [-a [name=][address][:port][,PROTO][,user=<user>][,group=<group>][,mode=<mode>]] [-b [host[:port]|path]] [-C] [-d] [-F] [-f config] [-h type[,options]] [-I clifile] [-i identity] [-j jail[,jailoptions]] [-l vsl] [-M address:port] [-n name] [-P file] [-p param=value] [-r param[,param...]] [-S secret-file] [-s [name=]kind[,options]] [-T address[:port]] [-t TTL] [-V] [-W waiter]
+varnishd 
+    [-a [name=][listen_address[,PROTO]]
+    [-b [host[:port]|path]]
+    [-C]
+    [-d]
+    [-F]
+    [-f config]
+    [-h type[,options]]
+    [-I clifile]
+    [-i identity]
+    [-j jail[,jailoptions]]
+    [-l vsl]
+    [-M address:port]
+    [-n workdir]
+    [-P file]
+    [-p param=value]
+    [-r param[,param...]]
+    [-S secret-file]
+    [-s [name=]kind[,options]]
+    [-T address[:port]]
+    [-t TTL]
+    [-V]
+    [-W waiter]
 
 varnishd [-x parameter|vsl|cli|builtin|optstring]
 
@@ -41,32 +63,41 @@ OPTIONS
 Basic options
 -------------
 
--a <[name=][address][:port][,PROTO][,user=<user>][,group=<group>][,mode=<mode>]>
+-a <[name=][listen_address[,PROTO]]>
 
-  Listen for client requests on the specified address and port. The
-  address can be a host name ("localhost"), an IPv4 dotted-quad
-  ("127.0.0.1"), an IPv6 address enclosed in square brackets
-  ("[::1]"), or a path beginning with a '/' for a Unix domain socket
-  ("/path/to/listen.sock"). If address is not specified, `varnishd`
-  will listen on all available IPv4 and IPv6 interfaces. If port is
-  not specified, port 80 (http) is used. At least one of address or
-  port is required.
-
-  If a Unix domain socket is specified as the listen address, then the
-  user, group and mode sub-arguments may be used to specify the
-  permissions of the socket file -- use names for user and group, and
-  a 3-digit octal value for mode. These sub-arguments are not
-  permitted if an IP address is specified. When Unix domain socket
-  listeners are in use, all VCL configurations must have version >=
-  4.1.
+  Accept for client requests on the specified listen_address (see below).
 
   Name is referenced in logs. If name is not specified, "a0", "a1",
-  etc. is used. An additional protocol type can be set for the
-  listening socket with PROTO. Valid protocol types are: HTTP
-  (default), and PROXY.
+  etc. is used.
+
+  PROTO can be "HTTP" (the default) or "PROXY".  Both version 1
+  and 2 of the proxy protocol can be used.
+
+  Multiple -a arguments are allowed.
+
+  If no -a argument is given, the default `-a :80` will listen to
+  all IPv4 and IPv6 interfaces.
+
+-a <[name=][ip_address][:port][,PROTO]>
+
+  The ip_address can be a host name ("localhost"), an IPv4 dotted-quad
+  ("127.0.0.1") or an IPv6 address enclosed in square brackets
+  ("[::1]")
+
+  If port is not specified, port 80 (http) is used.
 
-  Multiple listening addresses can be specified by using different
-  -a arguments.
+  At least one of ip_address or port is required.
+
+-a <[name=][path][,PROTO][,user=name][,group=name][,mode=octal]>
+
+  (VCL4.1 and higher)
+
+  Accept connections on a Unix domain socket.  Path must be absolute
+  ("/path/to/listen.sock").
+
+  The user, group and mode sub-arguments may be used to specify the
+  permissions of the socket file -- use names for user and group, and
+  a 3-digit octal value for mode.
 
 -b <[host[:port]|path]>
 
@@ -111,12 +142,17 @@ Basic options
 
 .. _opt_n:
 
--n name
+-n workdir
+
+  Runtime directory for the shared memory, compiled VCLs etc.
+
+  In performance critical applications, this directory should be
+  on a RAM backed filesystem.
+
+  Relative paths will be appended to `/var/run/` (NB: Binary packages
+  of Varnish may have adjusted this to the platform.)
 
-  Specify the name for this instance.  This name is used to construct
-  the name of the directory in which `varnishd` keeps temporary files
-  and persistent state. If the specified name begins with a forward slash,
-  it is interpreted as the absolute path to the directory.
+  The default value is `/var/run/varnishd` (NB: as above.)
 
 Documentation options
 ---------------------

lib/libvarnish/vin.c

@@ -27,17 +27,14 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * XXX: NB: also used in libvarnishapi
+ * NB: also used in libvarnishapi
  */
 
 #include "config.h"
 
-#include <limits.h>
-#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <unistd.h>
 
 #include "vdef.h"
 
@@ -48,45 +45,27 @@
 int
 VIN_n_Arg(const char *n_arg, char **dir)
 {
-	char nm[PATH_MAX];
-	char dn[PATH_MAX];
-	struct vsb vsb[1];
-	int i;
+	struct vsb *vsb;
 
 	AN(dir);
 
-	/* First: determine the name */
-
-	if (n_arg == NULL || *n_arg == '\0') {
-		if (gethostname(nm, sizeof nm) != 0)
-			return (-1);
-	} else if (strlen(n_arg) >= sizeof nm) {
-		/* preliminary length check to avoid overflowing nm */
-		errno = ENAMETOOLONG;
-		return (-1);
-	} else
-		bprintf(nm, "%s", n_arg);
-
-	/* Second: find the directory name */
-
-	AN(VSB_init(vsb, dn, sizeof dn));
-
-	if (*nm == '/')
-		i = VSB_printf(vsb, "%s/", nm);
-	else
-		i = VSB_printf(vsb, "%s/%s/", VARNISH_STATE_DIR, nm);
-
-	if (i != 0) {
-		errno = ENAMETOOLONG;
-		return (-1);
+	vsb = VSB_new_auto();
+	AN(vsb);
+	if (n_arg == NULL || n_arg[0] == '\0') {
+		VSB_cat(vsb, VARNISH_STATE_DIR);
+		VSB_cat(vsb, "/varnishd");
+	} else if (n_arg[0] == '/') {
+		VSB_cat(vsb, n_arg);
+	} else {
+		VSB_cat(vsb, VARNISH_STATE_DIR);
+		VSB_cat(vsb, "/");
+		VSB_cat(vsb, n_arg);
 	}
-
 	AZ(VSB_finish(vsb));
 
 	*dir = strdup(VSB_data(vsb));
+	VSB_destroy(&vsb);
 	if (*dir == NULL)
 		return (-1);
-
-	VSB_fini(vsb);
 	return (0);
 }