commit 3979c3e1bae20459d9b6d424bdb49927d9cd6fec

Author: Siddhesh Poyarekar <siddhesh@sourceware.org>

Date:   Mon Jun 7 14:22:18 2021 +0530

    iconvconfig: Read configuration from gconv-modules.d subdirectory

    In addition to GCONV_PATH/gconv-modules, also read module

    configuration from *.conf files in GCONV_PATH/gconv-modules.d.  This

    allows a single gconv directory to have multiple sets of gconv modules

    but at the same time, a single modules cache.

    With this feature, one could separate the glibc supported gconv

    modules into a minimal essential set (ISO-8859-*, UTF, etc.) from the

    remaining modules.  In future, these could be further segregated into

    langpack-associated sets with their own

    gconv-modules.d/someconfig.conf.

    Reviewed-by: DJ Delorie <dj@redhat.com>

diff --git a/iconv/iconvconfig.c b/iconv/iconvconfig.c

index 2b3c587bc77cfdcd..fafc686ae25fb5c1 100644

--- a/iconv/iconvconfig.c

+++ b/iconv/iconvconfig.c

@@ -18,6 +18,7 @@

 #include <argp.h>

 #include <assert.h>

+#include <dirent.h>

 #include <error.h>

 #include <errno.h>

 #include <fcntl.h>

@@ -33,6 +34,7 @@

 #include <string.h>

 #include <unistd.h>

 #include <sys/cdefs.h>

+#include <sys/types.h>

 #include <sys/uio.h>

 #include "iconvconfig.h"

@@ -710,6 +712,7 @@ handle_file (const char *dir, const char *infile)

 static int

 handle_dir (const char *dir)

 {

+#define BUF_LEN prefix_len + dirlen + sizeof "gconv-modules.d"

   char *cp;

   size_t dirlen = strlen (dir);

   bool found = false;

@@ -722,20 +725,55 @@ handle_dir (const char *dir)

       newp[dirlen] = '\0';

     }

-  char infile[prefix_len + dirlen + sizeof "gconv-modules"];

-  cp = infile;

+  /* First, look for a gconv-modules file.  */

+  char buf[BUF_LEN];

+  cp = buf;

   if (dir[0] == '/')

     cp = mempcpy (cp, prefix, prefix_len);

-  strcpy (mempcpy (cp, dir, dirlen), "gconv-modules");

+  cp = mempcpy (cp, dir, dirlen);

+  cp = stpcpy (cp, "gconv-modules");

-  found |= handle_file (dir, infile);

+  found |= handle_file (dir, buf);

+

+  /* Next, see if there is a gconv-modules.d directory containing configuration

+     files and if it is non-empty.  */

+  cp[0] = '.';

+  cp[1] = 'd';

+  cp[2] = '\0';

+

+  DIR *confdir = opendir (buf);

+  if (confdir != NULL)

+    {

+      struct dirent *ent;

+      while ((ent = readdir (confdir)) != NULL)

+	{

+	  if (ent->d_type != DT_REG)

+	    continue;

+

+	  size_t len = strlen (ent->d_name);

+	  const char *suffix = ".conf";

+

+	  if (len > strlen (suffix)

+	      && strcmp (ent->d_name + len - strlen (suffix), suffix) == 0)

+	    {

+	      /* LEN <= PATH_MAX so this alloca is not unbounded.  */

+	      char *conf = alloca (BUF_LEN + len + 1);

+	      cp = stpcpy (conf, buf);

+	      sprintf (cp, "/%s", ent->d_name);

+	      found |= handle_file (dir, conf);

+	    }

+	}

+      closedir (confdir);

+    }

   if (!found)

     {

-      error (0, errno, "failed to open gconv configuration file in `%s'",

+      error (0, errno, "failed to open gconv configuration files in `%s'",

 	     dir);

       error (0, 0,

-	     "ensure that the directory contains a valid gconv-modules file.");

+	     "ensure that the directory contains either a valid "

+	     "gconv-modules file or a gconv-modules.d directory with "

+	     "configuration files with names ending in .conf.");

     }

   return found ? 0 : 1;