1 files changed, 162 insertions, 0 deletions
diff --git a/src/commonlib/include/commonlib/iobuf.h b/src/commonlib/include/commonlib/iobuf.h
new file mode 100644
index 0000000000..c5a0f4c6fb
--- /dev/null
+++ b/src/commonlib/include/commonlib/iobuf.h
@@ -0,0 +1,162 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2017 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * 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.
+ */
+
+#ifndef COMMONLIB_IOBUF_H
+#define COMMONLIB_IOBUF_H
+
+#include <stdint.h>
+#include <sys/types.h>
+
+/*
+ * Two types are provided to aid in dealing with automatic buffer management
+ * for code that deals with serializing and deserializing data structures.
+ * The ibuf (input buffer) is read from while the obuf (output buffer) is
+ * written to. Both keep track of capacity of the buffer as well as current
+ * read or write cursor.
+ *
+ * When splicing or splitting ibufs of obufs the source object doesn't track
+ * reads or writes through the newly created objects back to the source object.
+ *
+ * Any function returning an int encodes the return values as < 0 on error
+ * and 0 on success. Any function returning a pointer returns NULL on error
+ * and non-NULL on success.
+ */
+
+struct ibuf {
+	const uint8_t *b;
+	size_t n_read;
+	size_t capacity;
+};
+
+struct obuf {
+	uint8_t *b;
+	size_t n_written;
+	size_t capacity;
+};
+
+/* Helper functions. */
+static inline size_t ibuf_capacity(const struct ibuf *ib)
+{
+	return ib->capacity;
+}
+
+static inline size_t ibuf_nr_read(const struct ibuf *ib)
+{
+	return ib->n_read;
+}
+
+static inline size_t ibuf_remaining(const struct ibuf *ib)
+{
+	return ibuf_capacity(ib) - ibuf_nr_read(ib);
+}
+
+static inline size_t obuf_capacity(const struct obuf *ob)
+{
+	return ob->capacity;
+}
+
+static inline size_t obuf_nr_written(const struct obuf *ob)
+{
+	return ob->n_written;
+}
+
+static inline size_t obuf_remaining(const struct obuf *ob)
+{
+	return obuf_capacity(ob) - obuf_nr_written(ob);
+}
+
+/* Initialize an ibuf with buffer and size of data. */
+void ibuf_init(struct ibuf *ib, const void *b, size_t sz);
+
+/* Create a new ibuf based on a subregion of the src ibuf. */
+int ibuf_splice(const struct ibuf *src, struct ibuf *dst, size_t off,
+		size_t sz);
+
+/* Same as ibuf_splice(), but start from last read byte offset. */
+int ibuf_splice_current(const struct ibuf *src, struct ibuf *dst, size_t sz);
+
+/* Split an ibuf into 2 new ibufs at provided boundary. */
+int ibuf_split(const struct ibuf *src, struct ibuf *a, struct ibuf *b,
+		size_t boundary);
+
+/* Out-of-band drain of ibuf by returning pointer to data of specified size. */
+const void *ibuf_oob_drain(struct ibuf *ib, size_t sz);
+
+/* Read arbitray data from input buffer. */
+int ibuf_read(struct ibuf *ib, void *data, size_t sz);
+
+/* Read big endian fixed size values. */
+int ibuf_read_be8(struct ibuf *ib, uint8_t *v);
+int ibuf_read_be16(struct ibuf *ib, uint16_t *v);
+int ibuf_read_be32(struct ibuf *ib, uint32_t *v);
+int ibuf_read_be64(struct ibuf *ib, uint64_t *v);
+
+/* Read little endian fixed size values. */
+int ibuf_read_le8(struct ibuf *ib, uint8_t *v);
+int ibuf_read_le16(struct ibuf *ib, uint16_t *v);
+int ibuf_read_le32(struct ibuf *ib, uint32_t *v);
+int ibuf_read_le64(struct ibuf *ib, uint64_t *v);
+
+/* Read native endian fixed size values. */
+int ibuf_read_n8(struct ibuf *ib, uint8_t *v);
+int ibuf_read_n16(struct ibuf *ib, uint16_t *v);
+int ibuf_read_n32(struct ibuf *ib, uint32_t *v);
+int ibuf_read_n64(struct ibuf *ib, uint64_t *v);
+
+/* Helper to create an ibuf from an obuf after an entity has written data. */
+void ibuf_from_obuf(struct ibuf *ib, const struct obuf *ob);
+
+/* Initialize an obuf with buffer and maximum capacity. */
+void obuf_init(struct obuf *ob, void *b, size_t sz);
+
+/* Provide the buffer and size of the written contents. */
+const void *obuf_contents(const struct obuf *ob, size_t *sz);
+
+/* Create a new obuf based on a subregion of the src obuf. */
+int obuf_splice(const struct obuf *src, struct obuf *dst, size_t off,
+		size_t sz);
+
+/* Same as obuf_splice(), but start from last written byte offset. */
+int obuf_splice_current(const struct obuf *src, struct obuf *dst, size_t sz);
+
+/* Split an obuf into 2 new obufs at provided boundary. */
+int obuf_split(const struct obuf *src, struct obuf *a, struct obuf *b,
+		size_t boundary);
+
+/* Fill the buffer out-of-band. The size is accounted for. */
+void *obuf_oob_fill(struct obuf *ob, size_t sz);
+
+/* Write arbitray data to output buffer. */
+int obuf_write(struct obuf *ob, const void *data, size_t sz);
+
+/* Write big endian fixed size values. */
+int obuf_write_be8(struct obuf *ob, uint8_t v);
+int obuf_write_be16(struct obuf *ob, uint16_t v);
+int obuf_write_be32(struct obuf *ob, uint32_t v);
+int obuf_write_be64(struct obuf *ob, uint64_t v);
+
+/* Write little endian fixed size values. */
+int obuf_write_le8(struct obuf *ob, uint8_t v);
+int obuf_write_le16(struct obuf *ob, uint16_t v);
+int obuf_write_le32(struct obuf *ob, uint32_t v);
+int obuf_write_le64(struct obuf *ob, uint64_t v);
+
+/* Write native endian fixed size values. */
+int obuf_write_n8(struct obuf *ob, uint8_t v);
+int obuf_write_n16(struct obuf *ob, uint16_t v);
+int obuf_write_n32(struct obuf *ob, uint32_t v);
+int obuf_write_n64(struct obuf *ob, uint64_t v);
+
+#endif