commit b17d29b390154df9dfad9d21f1e6605422521fd2

Author: Siddhesh Poyarekar <siddhesh@sourceware.org>

Date:   Mon Jun 7 14:22:19 2021 +0530

    gconv_conf: Read configuration files in gconv-modules.d

    Read configuration files with names ending in .conf in

    GCONV_PATH/gconv-modules.d to mirror configuration flexibility in

    iconvconfig into the iconv program and function.

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

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

index f173cde71b2a61d7..8eb981fca7cee36a 100644

--- a/iconv/gconv_conf.c

+++ b/iconv/gconv_conf.c

@@ -19,6 +19,7 @@

 #include <assert.h>

 #include <ctype.h>

+#include <dirent.h>

 #include <errno.h>

 #include <limits.h>

 #include <locale.h>

@@ -30,6 +31,7 @@

 #include <string.h>

 #include <unistd.h>

 #include <sys/param.h>

+#include <sys/types.h>

 #include <libc-lock.h>

 #include <gconv_int.h>

@@ -50,6 +52,7 @@ static const struct path_elem empty_path_elem = { NULL, 0 };

 /* Name of the file containing the module information in the directories

    along the path.  */

 static const char gconv_conf_filename[] = "gconv-modules";

+static const char gconv_conf_dirname[] = "gconv-modules.d";

 /* Filename extension for the modules.  */

 #ifndef MODULE_EXT

@@ -554,18 +557,52 @@ __gconv_read_conf (void)

   for (cnt = 0; __gconv_path_elem[cnt].name != NULL; ++cnt)

     {

+#define BUF_LEN elem_len + sizeof (gconv_conf_dirname)

+

       const char *elem = __gconv_path_elem[cnt].name;

       size_t elem_len = __gconv_path_elem[cnt].len;

-      char *filename;

+      char *buf;

       /* No slash needs to be inserted between elem and gconv_conf_filename;

 	 elem already ends in a slash.  */

-      filename = alloca (elem_len + sizeof (gconv_conf_filename));

-      __mempcpy (__mempcpy (filename, elem, elem_len),

-		 gconv_conf_filename, sizeof (gconv_conf_filename));

+      buf = alloca (BUF_LEN);

+      char *cp = __mempcpy (__mempcpy (buf, elem, elem_len),

+			    gconv_conf_filename, sizeof (gconv_conf_filename));

+

+      /* Read the gconv-modules configuration file first.  */

+      read_conf_file (buf, elem, elem_len, &modules, &nmodules);

+

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

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

+      cp--;

+      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";

-      /* Read the next configuration file.  */

-      read_conf_file (filename, elem, elem_len, &modules, &nmodules);

+	      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);

+		  read_conf_file (conf, elem, elem_len, &modules, &nmodules);

+		}

+	    }

+	  __closedir (confdir);

+	}

     }

 #endif