add alloc.h

diff --git a/include/share/Makefile.am b/include/share/Makefile.am
index b50d883..513828b 100644 (file)
--- a/include/share/Makefile.am
+++ b/include/share/Makefile.am
@@ -5,6 +5,7 @@ AUTOMAKE_OPTIONS = foreign
 SUBDIRS = grabbag
 
 EXTRA_DIST = \
+       alloc.h \
        getopt.h \
        grabbag.h \
        replaygain_analysis.h \

diff --git a/include/share/alloc.h b/include/share/alloc.h
new file mode 100644 (file)
index 0000000..350f63c
--- /dev/null
+++ b/include/share/alloc.h
@@ -0,0 +1,171 @@
+/* alloc - Convenience routines for safely allocating memory
+ * Copyright (C) 2007  Josh Coalson
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef FLAC__SHARE__ALLOC_H
+#define FLAC__SHARE__ALLOC_H
+
+/* WATCHOUT: for c++ you may have to #define __STDC_LIMIT_MACROS 1 real early
+ * before #including this file,  otherwise SIZE_MAX might not be defined
+ */
+
+#include <limits.h> /* for SIZE_MAX */
+#if !defined _MSC_VER && !defined __MINGW32__ && !defined __EMX__
+#include <stdint.h> /* for SIZE_MAX in case limits.h didn't get it */
+#endif
+#include <stdlib.h> /* for size_t, malloc(), etc */
+
+/* avoid malloc()ing 0 bytes, see:
+ * https://www.securecoding.cert.org/confluence/display/seccode/MEM04-A.+Do+not+make+assumptions+about+the+result+of+allocating+0+bytes?focusedCommentId=5407003
+*/
+static void *safe_malloc_(size_t size)
+{
+       /* malloc(0) is undefined; FLAC src convention is to always allocate */
+       if(!size)
+               size++;
+       return malloc(size);
+}
+
+static void *safe_calloc_(size_t nmemb, size_t size)
+{
+       if(!nmemb || !size)
+               return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
+       return calloc(nmemb, size);
+}
+
+/*@@@@ there's probably a better way to prevent overflows when allocating untrusted sums but this works for now */
+
+static void *safe_malloc_add_2op_(size_t size1, size_t size2)
+{
+       size2 += size1;
+       if(size2 < size1)
+               return 0;
+       return safe_malloc_(size2);
+}
+
+static void *safe_malloc_add_3op_(size_t size1, size_t size2, size_t size3)
+{
+       size2 += size1;
+       if(size2 < size1)
+               return 0;
+       size3 += size2;
+       if(size3 < size2)
+               return 0;
+       return safe_malloc_(size3);
+}
+
+static void *safe_malloc_add_4op_(size_t size1, size_t size2, size_t size3, size_t size4)
+{
+       size2 += size1;
+       if(size2 < size1)
+               return 0;
+       size3 += size2;
+       if(size3 < size2)
+               return 0;
+       size4 += size3;
+       if(size4 < size3)
+               return 0;
+       return safe_malloc_(size4);
+}
+
+static void *safe_malloc_mul_2op_(size_t size1, size_t size2)
+#if 0
+needs support for cases where sizeof(size_t) != 4
+{
+       /* could be faster #ifdef'ing off SIZEOF_SIZE_T */
+       if(sizeof(size_t) == 4) {
+               if ((double)size1 * (double)size2 < 4294967296.0)
+                       return malloc(size1*size2);
+       }
+       return 0;
+}
+#else
+/* better? */
+{
+       if(!size1 || !size2)
+               return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
+       if(size1 > SIZE_MAX / size2)
+               return 0;
+       return malloc(size1*size2);
+}
+#endif
+
+static void *safe_malloc_mul_3op_(size_t size1, size_t size2, size_t size3)
+{
+       if(!size1 || !size2 || !size3)
+               return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
+       if(size1 > SIZE_MAX / size2)
+               return 0;
+       size1 *= size2;
+       if(size1 > SIZE_MAX / size3)
+               return 0;
+       return malloc(size1*size3);
+}
+
+/* size1*size2 + size3 */
+static void *safe_malloc_mul2add_(size_t size1, size_t size2, size_t size3)
+{
+       if(!size1 || !size2)
+               return safe_malloc_(size3);
+       if(size1 > SIZE_MAX / size2)
+               return 0;
+       return safe_malloc_add_2op_(size1*size2, size3);
+}
+
+static void *safe_realloc_add_2op_(void *ptr, size_t size1, size_t size2)
+{
+       size2 += size1;
+       if(size2 < size1)
+               return 0;
+       return realloc(ptr, size2);
+}
+
+static void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3)
+{
+       size2 += size1;
+       if(size2 < size1)
+               return 0;
+       size3 += size2;
+       if(size3 < size2)
+               return 0;
+       return realloc(ptr, size3);
+}
+
+static void *safe_realloc_add_4op_(void *ptr, size_t size1, size_t size2, size_t size3, size_t size4)
+{
+       size2 += size1;
+       if(size2 < size1)
+               return 0;
+       size3 += size2;
+       if(size3 < size2)
+               return 0;
+       size4 += size3;
+       if(size4 < size3)
+               return 0;
+       return realloc(ptr, size4);
+}
+
+static void *safe_realloc_mul_2op_(void *ptr, size_t size1, size_t size2)
+{
+       if(!size1 || !size2)
+               return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
+       if(size1 > SIZE_MAX / size2)
+               return 0;
+       return realloc(ptr, size1*size2);
+}
+
+#endif