common/include: Add ASCII-only ctype header and ascii_is* functions.

Our existing uses of <ctype.h> were not necessarily safe if the locale
was changed.

Also I removed the unnecessary use of isascii, deprecated by POSIX.1-2008.

.gitignore

@@ -33,6 +33,7 @@ plugins/*/*.3
 /aclocal.m4
 /autom4te.cache
 /common/bitmap/test-bitmap
+/common/include/test-ascii-ctype
 /common/include/test-byte-swapping
 /common/include/test-current-dir-name
 /common/include/test-isaligned

common/include/Makefile.am

@@ -34,6 +34,7 @@ include $(top_srcdir)/common-rules.mk
 # These headers contain only common code shared by the core server,
 # plugins and/or filters.  They are not installed.
 EXTRA_DIST = \
+	ascii-ctype.h \
 	byte-swapping.h \
 	exit-with-parent.h \
 	get-current-dir-name.h \
@@ -50,6 +51,7 @@ EXTRA_DIST = \
 # Unit tests.
 
 TESTS = \
+	test-ascii-ctype \
 	test-byte-swapping \
 	test-current-dir-name \
 	test-isaligned \
@@ -62,6 +64,10 @@ TESTS = \
 	$(NULL)
 check_PROGRAMS = $(TESTS)
 
+test_ascii_ctype_SOURCES = test-ascii-ctype.c ascii-ctype.h
+test_ascii_ctype_CPPFLAGS = -I$(srcdir)
+test_ascii_ctype_CFLAGS = $(WARNINGS_CFLAGS)
+
 test_byte_swapping_SOURCES = test-byte-swapping.c byte-swapping.h
 test_byte_swapping_CPPFLAGS = -I$(srcdir)
 test_byte_swapping_CFLAGS = $(WARNINGS_CFLAGS)

common/include/ascii-ctype.h

@@ -0,0 +1,60 @@
+/* nbdkit
+ * Copyright (C) 2013-2020 Red Hat Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of Red Hat nor the names of its contributors may be
+ * used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/* Normal ctype functions are affected by the current locale.  For
+ * example isupper() might recognize Ä in some but not all locales.
+ * These functions match only 7 bit ASCII characters.
+ */
+
+#ifndef NBDKIT_ASCII_CTYPE_H
+#define NBDKIT_ASCII_CTYPE_H
+
+#define ascii_isalnum(c) (ascii_isalpha (c) || ascii_isdigit (c))
+
+#define ascii_isalpha(c)                                        \
+  (((c) >= 'a' && (c) <= 'z') || ((c) >= 'A' && (c) <= 'Z'))
+
+#define ascii_isdigit(c)                        \
+  ((c) >= '0' && (c) <= '9')
+
+#define ascii_isspace(c)                                                \
+  ((c) == '\t' || (c) == '\n' || (c) == '\f' || (c) == '\r' || (c) == ' ')
+
+#define ascii_isxdigit(c)                                               \
+  ((c) == '0' || (c) == '1' || (c) == '2' || (c) == '3' || (c) == '4' || \
+   (c) == '5' || (c) == '6' || (c) == '7' || (c) == '8' || (c) == '9' || \
+   (c) == 'a' || (c) == 'b' || (c) == 'c' ||                            \
+   (c) == 'd' || (c) == 'e' || (c) == 'f' ||                            \
+   (c) == 'A' || (c) == 'B' || (c) == 'C' ||                            \
+   (c) == 'D' || (c) == 'E' || (c) == 'F')
+
+#endif /* NBDKIT_ASCII_CTYPE_H */

common/include/test-ascii-ctype.c

@@ -0,0 +1,63 @@
+/* nbdkit
+ * Copyright (C) 2020 Red Hat Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of Red Hat nor the names of its contributors may be
+ * used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include "ascii-ctype.h"
+
+int
+main (void)
+{
+  assert (ascii_isspace (' '));
+  assert (ascii_isspace ('\t'));
+  assert (ascii_isspace ('\n'));
+  assert (! ascii_isspace ('a'));
+
+  assert (ascii_isalpha ('a'));
+  assert (ascii_isalpha ('Z'));
+  assert (ascii_isalpha ('z'));
+  assert (! ascii_isalpha (' '));
+  assert (! ascii_isalpha ('0'));
+  { const char *s = "Ä"; assert (! ascii_isalpha (s[0])); }
+  { const char *s = "®"; assert (! ascii_isalpha (s[0])); }
+
+  assert (ascii_isdigit ('0'));
+  assert (ascii_isdigit ('9'));
+  { const char *s = "Ø"; assert (! ascii_isdigit (s[0])); } /* U+00D8 */
+  { const char *s = "９"; assert (! ascii_isdigit (s[0])); } /* U+FF19 */
+
+  exit (EXIT_SUCCESS);
+}

plugins/partitioning/partition-gpt.c

@@ -36,12 +36,12 @@
 #include <stdlib.h>
 #include <stdbool.h>
 #include <string.h>
-#include <ctype.h>
 #include <inttypes.h>
 #include <assert.h>
 
 #include <nbdkit-plugin.h>
 
+#include "ascii-ctype.h"
 #include "byte-swapping.h"
 
 #include "efi-crc32.h"
@@ -244,19 +244,19 @@ parse_guid (const char *str, char *out)
     return -1;
 
   for (i = 0; i < 8; ++i)
-    if (!isxdigit (str[i]))
+    if (!ascii_isxdigit (str[i]))
       return -1;
   for (i = 9; i < 13; ++i)
-    if (!isxdigit (str[i]))
+    if (!ascii_isxdigit (str[i]))
       return -1;
   for (i = 14; i < 18; ++i)
-    if (!isxdigit (str[i]))
+    if (!ascii_isxdigit (str[i]))
       return -1;
   for (i = 19; i < 23; ++i)
-    if (!isxdigit (str[i]))
+    if (!ascii_isxdigit (str[i]))
       return -1;
   for (i = 24; i < 36; ++i)
-    if (!isxdigit (str[i]))
+    if (!ascii_isxdigit (str[i]))
       return -1;
 
   /* The first, second and third blocks are parsed as little endian,

plugins/sh/Makefile.am

@@ -50,6 +50,7 @@ nbdkit_sh_plugin_la_SOURCES = \
 
 nbdkit_sh_plugin_la_CPPFLAGS = \
 	-I$(top_srcdir)/include \
+	-I$(top_srcdir)/common/include \
 	-I$(top_srcdir)/common/utils \
 	$(NULL)
 nbdkit_sh_plugin_la_CFLAGS = $(WARNINGS_CFLAGS)

plugins/sh/call.c

@@ -44,10 +44,10 @@
 #include <poll.h>
 #include <sys/types.h>
 #include <sys/wait.h>
-#include <ctype.h>
 
 #include <nbdkit-plugin.h>
 
+#include "ascii-ctype.h"
 #include "cleanup.h"
 #include "utils.h"
 
@@ -443,15 +443,15 @@ handle_script_error (const char *argv0, char *ebuf, size_t len)
   }
 
   if (skip && ebuf[skip]) {
-    if (!isspace ((unsigned char) ebuf[skip])) {
+    if (!ascii_isspace ((unsigned char) ebuf[skip])) {
       /* Treat 'EINVALID' as EIO, not EINVAL */
       err = EIO;
       skip = 0;
     }
     else
       do
         skip++;
-      while (isspace ((unsigned char) ebuf[skip]));
+      while (ascii_isspace ((unsigned char) ebuf[skip]));
   }
 
   while (len > 0 && ebuf[len-1] == '\n')

server/backend.c

@@ -37,13 +37,14 @@
 #include <inttypes.h>
 #include <string.h>
 #include <assert.h>
-#include <ctype.h>
 
 #include <dlfcn.h>
 
-#include "internal.h"
+#include "ascii-ctype.h"
 #include "minmax.h"
 
+#include "internal.h"
+
 /* Helpers for registering a new backend. */
 
 /* Use:
@@ -100,7 +101,7 @@ backend_load (struct backend *b, const char *name, void (*load) (void))
   for (i = 0; i < len; ++i) {
     unsigned char c = name[i];
 
-    if (!(isascii (c) && isalnum (c))) {
+    if (! ascii_isalnum (c)) {
       fprintf (stderr,
                "%s: %s: %s.name ('%s') field "
                "must contain only ASCII alphanumeric characters\n",

server/public.c

@@ -45,13 +45,13 @@
 #include <string.h>
 #include <unistd.h>
 #include <limits.h>
-#include <ctype.h>
 #include <termios.h>
 #include <errno.h>
 #include <poll.h>
 #include <signal.h>
 #include <sys/socket.h>
 
+#include "ascii-ctype.h"
 #include "get-current-dir-name.h"
 
 #include "internal.h"
@@ -210,7 +210,7 @@ nbdkit_parse_int64_t (const char *what, const char *str, int64_t *rp)
  */
 #define PARSE_ERROR_IF_NEGATIVE                                         \
   do {                                                                  \
-    while (isspace (*str))                                              \
+    while (ascii_isspace (*str))                                        \
       str++;                                                            \
     if (*str == '-') {                                                  \
       nbdkit_error ("%s: negative numbers are not allowed", what);      \