add utils.c, containing a calloc-like function to allocate multiple chunks with different sizes in one block and return pointers

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

1 files changed, 54 insertions, 0 deletions

diff --git a/utils.c b/utils.c
new file mode 100644
index 0000000..4589da8
--- /dev/null
+++ b/utils.c
@@ -0,0 +1,54 @@
+/*
+ * utils - misc libubox utility functions
+ *
+ * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
+ *
+ * Permission to use, copy, modify, and/or 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 "utils.h"
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#define foreach_arg(_arg, _addr, _len, _first_addr, _first_len) \
+	for (_addr = (_first_addr), _len = (_first_len); \
+		_addr; \
+		_addr = va_arg(_arg, void **), _len = _addr ? va_arg(_arg, size_t) : 0)
+
+void *__calloc_a(size_t len, ...)
+{
+	va_list ap, ap1;
+	void *ret;
+	void **cur_addr;
+	size_t cur_len;
+	int alloc_len = 0;
+	char *ptr;
+
+	va_start(ap, len);
+
+	va_copy(ap1, ap);
+	foreach_arg(ap1, cur_addr, cur_len, &ret, len)
+		alloc_len += cur_len;
+	va_end(ap1);
+
+	ptr = calloc(1, alloc_len);
+	alloc_len = 0;
+	foreach_arg(ap, cur_addr, cur_len, &ret, len) {
+		*cur_addr = &ptr[alloc_len];
+		alloc_len += cur_len;
+	}
+	va_end(ap);
+
+	return ret;
+}