Initial import

1 files changed, 177 insertions, 0 deletions

diff --git a/blob.c b/blob.c
new file mode 100644
index 0000000..823eb24
--- /dev/null
+++ b/blob.c
@@ -0,0 +1,177 @@
+/*
+ * blob - library for generating/parsing tagged binary data
+ *
+ * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation
+ *
+ * This program 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 General Public License for more details.
+ */
+
+#include "blob.h"
+
+static bool
+blob_buffer_grow(struct blob_buf *buf, int minlen)
+{
+	buf->buflen += ((minlen / 256) + 1) * 256;
+	buf->buf = realloc(buf->buf, buf->buflen);
+	return !!buf->buf;
+}
+
+static void
+blob_init(struct blob_attr *attr, int id, unsigned int len)
+{
+	len &= BLOB_ATTR_LEN_MASK;
+	len |= (id << BLOB_ATTR_ID_SHIFT) & BLOB_ATTR_ID_MASK;
+	attr->id_len = cpu_to_be32(len);
+}
+
+static inline struct blob_attr *
+offset_to_attr(struct blob_buf *buf, int offset)
+{
+	void *ptr = (char *)buf->buf + offset;
+	return ptr;
+}
+
+static inline int
+attr_to_offset(struct blob_buf *buf, struct blob_attr *attr)
+{
+	return (char *)attr - (char *) buf->buf;
+}
+
+static struct blob_attr *
+blob_add(struct blob_buf *buf, struct blob_attr *pos, int id, int payload)
+{
+	int offset = attr_to_offset(buf, pos);
+	int required = (offset + sizeof(struct blob_attr) + payload) - buf->buflen;
+	struct blob_attr *attr;
+
+	if (required > 0) {
+		int offset_head = attr_to_offset(buf, buf->head);
+
+		if (!buf->grow || !buf->grow(buf, required))
+			return NULL;
+
+		buf->head = offset_to_attr(buf, offset_head);
+		attr = offset_to_attr(buf, offset);
+	} else {
+		attr = pos;
+	}
+
+	blob_init(attr, id, payload + sizeof(struct blob_attr));
+	return attr;
+}
+
+int
+blob_buf_init(struct blob_buf *buf, int id)
+{
+	if (!buf->grow)
+		buf->grow = blob_buffer_grow;
+
+	buf->head = buf->buf;
+	if (blob_add(buf, buf->buf, id, 0) == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+struct blob_attr *
+blob_new(struct blob_buf *buf, int id, int payload)
+{
+	struct blob_attr *attr;
+
+	attr = blob_add(buf, blob_next(buf->head), id, payload);
+	if (!attr)
+		return NULL;
+
+	blob_set_raw_len(buf->head, blob_pad_len(buf->head) + blob_pad_len(attr));
+	return attr;
+}
+
+struct blob_attr *
+blob_put(struct blob_buf *buf, int id, const void *ptr, int len)
+{
+	struct blob_attr *attr;
+
+	attr = blob_new(buf, id, len);
+	if (!attr)
+		return NULL;
+
+	if (ptr)
+		memcpy(blob_data(attr), ptr, len);
+	return attr;
+}
+
+void *
+blob_nest_start(struct blob_buf *buf, int id)
+{
+	unsigned long offset = attr_to_offset(buf, buf->head);
+	buf->head = blob_new(buf, id, 0);
+	return (void *) offset;
+}
+
+void
+blob_nest_end(struct blob_buf *buf, void *cookie)
+{
+	struct blob_attr *attr = offset_to_attr(buf, (unsigned long) cookie);
+	blob_set_raw_len(attr, blob_pad_len(attr) + blob_len(buf->head));
+	buf->head = attr;
+}
+
+static const int blob_type_minlen[BLOB_ATTR_LAST] = {
+	[BLOB_ATTR_STRING] = 1,
+	[BLOB_ATTR_INT8] = sizeof(uint8_t),
+	[BLOB_ATTR_INT16] = sizeof(uint16_t),
+	[BLOB_ATTR_INT32] = sizeof(uint32_t),
+	[BLOB_ATTR_INT64] = sizeof(uint64_t),
+};
+
+int
+blob_parse(struct blob_attr *attr, struct blob_attr **data, struct blob_attr_info *info, int max)
+{
+	struct blob_attr *pos;
+	int found = 0;
+	int rem;
+
+	memset(data, 0, sizeof(struct blob_attr *) * max);
+	blob_for_each_attr(pos, attr, rem) {
+		int id = blob_id(pos);
+		int len = blob_len(pos);
+
+		if (id >= max)
+			continue;
+
+		if (info) {
+			int type = info[id].type;
+			if (type < BLOB_ATTR_LAST) {
+				if (type >= BLOB_ATTR_INT8 && type <= BLOB_ATTR_INT64) {
+					if (len != blob_type_minlen[type])
+						continue;
+				} else {
+					if (len < blob_type_minlen[type])
+						continue;
+				}
+			}
+
+			if (info[id].minlen && len < info[id].minlen)
+				continue;
+
+			if (info[id].maxlen && len > info[id].maxlen)
+				continue;
+
+			if (info[id].validate && !info[id].validate(&info[id], attr))
+				continue;
+		}
+
+		if (!data[id])
+			found++;
+
+		data[id] = pos;
+	}
+	return found;
+}