Add OpenBSD reallocarray(3) v1.2

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Makefile.am

@@ -4,8 +4,9 @@ lib_LTLIBRARIES     = libite.la
 pkgincludedir       = $(includedir)/lite
 pkginclude_HEADERS  = lite.h queue.h conio.h tree.h
 libite_la_SOURCES   = chomp.c copyfile.c dir.c fexist.c fisdir.c fmode.c fsendfile.c	\
-			ifconfig.c lfile.c makepath.c pidfile.c pidfilefn.c progress.c	\
-			rsync.c strlcpy.c strlcat.c strtonum.c tempfile.c tree.c
+		      ifconfig.c lfile.c makepath.c pidfile.c pidfilefn.c progress.c	\
+		      reallocarray.c rsync.c strlcpy.c strlcat.c strtonum.c tempfile.c	\
+		      tree.c
 
 libite_la_CPPFLAGS  = -D_GNU_SOURCE
 libite_la_CFLAGS    = -W -Wall -Wextra

README.md

@@ -296,6 +296,10 @@ The following are popular OpenBSD functions and highly useful macros.
   file `__pidfile_name`, similar to `__progname`.  See previous section
   for details.
 
+- `reallocarray(ptr, nmemb, size)`
+
+  http://man.openbsd.org/OpenBSD-current/man3/reallocarray.3
+
 - `strlcpy(dst, src, len)`
 
   http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man3/strlcpy.3

lite.h

@@ -68,6 +68,8 @@ int     pidfile_signal(const char *pidfile, int signal);
 pid_t   pidfile_read  (const char *pidfile);
 pid_t   pidfile_poll  (const char *pidfile);
 
+void   *reallocarray(void *optr, size_t nmemb, size_t size);
+
 #ifndef strlcpy
 size_t  strlcpy    (char *dst, const char *src, size_t siz);
 #endif

reallocarray.c

@@ -0,0 +1,38 @@
+/*	$OpenBSD: reallocarray.c,v 1.2 2014/12/08 03:45:00 bcook Exp $	*/
+/*
+ * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+/*
+ * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
+ * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
+ */
+#define MUL_NO_OVERFLOW ((size_t)1 << (sizeof(size_t) * 4))
+
+void *
+reallocarray(void *optr, size_t nmemb, size_t size)
+{
+	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
+	    nmemb > 0 && SIZE_MAX / nmemb < size) {
+		errno = ENOMEM;
+		return NULL;
+	}
+	return realloc(optr, size * nmemb);
+}