Add canonicalize option to hostmux

Taking the canonical name makes very little sense nowadays with a lot of
services behind the same IP but virtual hostnames.

* hostmux/hostmux.h (hostmux): Add canonicalize field.
* hostmux/hostmux.c (options, parse_opt): Add -C/--canonicalize option.
* hostmux/mux.c (lookup_host): Only call getaddrinfo if canonicalize is
true, pass NULL as HE to lookup_addrinfo otherwise.
(lookup_addrinfo): When !HE, use name given by user.

3 files changed, 22 insertions, 8 deletions

diff --git a/hostmux/hostmux.c b/hostmux/hostmux.c
index 3778613c..5296527b 100644
--- a/hostmux/hostmux.c
+++ b/hostmux/hostmux.c
@@ -45,6 +45,9 @@ static const struct argp_option options[] =
     "The string to replace in the translator specification with the hostname;"
     " if empty, or doesn't occur, the hostname is appended as additional"
     " argument instead (default `" DEFAULT_HOST_PAT "')" },
+  { "canonicalize", 'C', 0, 0,
+    "Canonicalize hostname before passing it to TRANSLATOR, aliases will"
+    " show up as symbolic links to the canonicalized entry" },
   { 0 }
 };
 static const char args_doc[] = "TRANSLATOR [ARG...]";
@@ -97,6 +100,8 @@ main (int argc, char **argv)
 	{
 	case 'H':
 	  mux.host_pat = arg; break;
+	case 'C':
+	  mux.canonicalize = 1; break;
 	case ARGP_KEY_NO_ARGS:
 	  argp_usage (state);
 	case ARGP_KEY_ARGS:
diff --git a/hostmux/hostmux.h b/hostmux/hostmux.h
index e6cfb767..4f971473 100644
--- a/hostmux/hostmux.h
+++ b/hostmux/hostmux.h
@@ -55,6 +55,9 @@ struct hostmux
      argument.  */
   char *host_pat;
 
+  /* Whether we should canonicalize host names or not.  */
+  boolean_t canonicalize;
+
   /* Constant fields for host stat entries.  */
   struct stat stat_template;
 
@@ -69,9 +72,10 @@ struct hostmux_name
   const char *name;		/* Looked up name (may be a number).  */
   const char *canon;		/* The canonical (fq) host name.  */
 
-  /* A filesystem node associated with NAME.  If NAME = CANON, then this will
-     refer to a node with a translator for that host, otherwise, the node
-     will be a symbolic link to the canonical name.  */
+  /* A filesystem node associated with NAME.  If canonicalize is 0 or
+     NAME = CANON, then this will refer to a node with a translator for that
+     host, otherwise, the node will be a symbolic link to the canonical name.
+     */
   struct node *node;
 
   ino_t fileno;			/* The inode number for this entry.  */
diff --git a/hostmux/mux.c b/hostmux/mux.c
index 737240af..81d3961f 100644
--- a/hostmux/mux.c
+++ b/hostmux/mux.c
@@ -283,7 +283,7 @@ lookup_addrinfo (struct hostmux *mux, const char *host, struct addrinfo *he,
     return ENOMEM;
 
   nm->name = strdup (host);
-  if (strcmp (host, he->ai_canonname) == 0)
+  if (!he || strcmp (host, he->ai_canonname) == 0)
     nm->canon = nm->name;
   else
     nm->canon = strdup (he->ai_canonname);
@@ -340,12 +340,17 @@ lookup_host (struct hostmux *mux, const char *host, struct node **node)
   if (was_cached)
     return 0;
 
-  h_err = getaddrinfo (host, NULL, &hints, &ai);
-  if (! h_err)
+  if (mux->canonicalize)
     {
-      h_err = lookup_addrinfo (mux, host, ai, node);
-      freeaddrinfo (ai);
+      h_err = getaddrinfo (host, NULL, &hints, &ai);
+      if (! h_err)
+	{
+	  h_err = lookup_addrinfo (mux, host, ai, node);
+	  freeaddrinfo (ai);
+	}
     }
+  else
+    h_err = lookup_addrinfo (mux, host, NULL, node);
 
   return h_err;
 }