--- /dev/null
+/*
+ * msgpack.c
+ *
+ * Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com>
+ *
+ * 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; only
+ * version 2.1 of the License.
+ *
+ * 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
+ */
+
+#define _GNU_SOURCE
+#define _LGPL_SOURCE
+#include <stddef.h>
+
+#define MSGPACK_FIXSTR_ID_MASK 0xA0
+#define MSGPACK_FIXMAP_ID_MASK 0x80
+#define MSGPACK_FIXARRAY_ID_MASK 0x90
+
+#define MSGPACK_NIL_ID 0xC0
+#define MSGPACK_FALSE_ID 0xC2
+#define MSGPACK_TRUE_ID 0xC3
+#define MSGPACK_MAP16_ID 0xDE
+#define MSGPACK_ARRAY16_ID 0xDC
+
+#define MSGPACK_UINT8_ID 0xCC
+#define MSGPACK_UINT16_ID 0xCD
+#define MSGPACK_UINT32_ID 0xCE
+#define MSGPACK_UINT64_ID 0xCF
+
+#define MSGPACK_INT8_ID 0xD0
+#define MSGPACK_INT16_ID 0xD1
+#define MSGPACK_INT32_ID 0xD2
+#define MSGPACK_INT64_ID 0xD3
+
+#define MSGPACK_FLOAT64_ID 0xCB
+#define MSGPACK_STR16_ID 0xDA
+
+#define MSGPACK_FIXINT_MAX ((1 << 7) - 1)
+#define MSGPACK_FIXINT_MIN -(1 << 5)
+#define MSGPACK_FIXMAP_MAX_COUNT 15
+#define MSGPACK_FIXARRAY_MAX_COUNT 15
+#define MSGPACK_FIXSTR_MAX_LENGTH 31
+
+#ifdef __KERNEL__
+#include <linux/bug.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include <lttng/msgpack.h>
+
+#define INT8_MIN (-128)
+#define INT16_MIN (-32767-1)
+#define INT32_MIN (-2147483647-1)
+#define INT8_MAX (127)
+#define INT16_MAX (32767)
+#define INT32_MAX (2147483647)
+#define UINT8_MAX (255)
+#define UINT16_MAX (65535)
+#define UINT32_MAX (4294967295U)
+
+#define byteswap_host_to_be16(_tmp) cpu_to_be16(_tmp)
+#define byteswap_host_to_be32(_tmp) cpu_to_be32(_tmp)
+#define byteswap_host_to_be64(_tmp) cpu_to_be64(_tmp)
+
+#define lttng_msgpack_assert(cond) WARN_ON(!(cond))
+
+#else /* __KERNEL__ */
+
+#include <endian.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "msgpack.h"
+
+#define byteswap_host_to_be16(_tmp) htobe16(_tmp)
+#define byteswap_host_to_be32(_tmp) htobe32(_tmp)
+#define byteswap_host_to_be64(_tmp) htobe64(_tmp)
+
+#define lttng_msgpack_assert(cond) ({ \
+ if (!(cond)) \
+ fprintf(stderr, "Assertion failed. %s:%d\n", __FILE__, __LINE__); \
+ })
+#endif /* __KERNEL__ */
+
+static inline int lttng_msgpack_append_buffer(
+ struct lttng_msgpack_writer *writer,
+ const uint8_t *buf,
+ size_t length)
+{
+ int ret = 0;
+
+ lttng_msgpack_assert(buf);
+
+ /* Ensure we are not trying to write after the end of the buffer. */
+ if (writer->write_pos + length > writer->end_write_pos) {
+ ret = -1;
+ goto end;
+ }
+
+ memcpy(writer->write_pos, buf, length);
+ writer->write_pos += length;
+end:
+ return ret;
+}
+
+static inline int lttng_msgpack_append_u8(
+ struct lttng_msgpack_writer *writer, uint8_t value)
+{
+ return lttng_msgpack_append_buffer(writer, &value, sizeof(value));
+}
+
+static inline int lttng_msgpack_append_u16(
+ struct lttng_msgpack_writer *writer, uint16_t value)
+{
+ value = byteswap_host_to_be16(value);
+
+ return lttng_msgpack_append_buffer(writer, (uint8_t *) &value, sizeof(value));
+}
+
+static inline int lttng_msgpack_append_u32(
+ struct lttng_msgpack_writer *writer, uint32_t value)
+{
+ value = byteswap_host_to_be32(value);
+
+ return lttng_msgpack_append_buffer(writer, (uint8_t *) &value, sizeof(value));
+}
+
+static inline int lttng_msgpack_append_u64(
+ struct lttng_msgpack_writer *writer, uint64_t value)
+{
+ value = byteswap_host_to_be64(value);
+
+ return lttng_msgpack_append_buffer(writer, (uint8_t *) &value, sizeof(value));
+}
+
+static inline int lttng_msgpack_append_f64(
+ struct lttng_msgpack_writer *writer, double value)
+{
+
+ union {
+ double d;
+ uint64_t u;
+ } u;
+
+ u.d = value;
+
+ return lttng_msgpack_append_u64(writer, u.u);
+}
+
+static inline int lttng_msgpack_append_i8(
+ struct lttng_msgpack_writer *writer, int8_t value)
+{
+ return lttng_msgpack_append_u8(writer, (uint8_t) value);
+}
+
+static inline int lttng_msgpack_append_i16(
+ struct lttng_msgpack_writer *writer, int16_t value)
+{
+ return lttng_msgpack_append_u16(writer, (uint16_t) value);
+}
+
+static inline int lttng_msgpack_append_i32(
+ struct lttng_msgpack_writer *writer, int32_t value)
+{
+ return lttng_msgpack_append_u32(writer, (uint32_t) value);
+}
+
+static inline int lttng_msgpack_append_i64(
+ struct lttng_msgpack_writer *writer, int64_t value)
+{
+ return lttng_msgpack_append_u64(writer, (uint64_t) value);
+}
+
+static inline int lttng_msgpack_encode_f64(
+ struct lttng_msgpack_writer *writer, double value)
+{
+ int ret;
+
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_FLOAT64_ID);
+ if (ret)
+ goto end;
+
+ ret = lttng_msgpack_append_f64(writer, value);
+ if (ret)
+ goto end;
+
+end:
+ return ret;
+}
+
+static inline int lttng_msgpack_encode_fixmap(
+ struct lttng_msgpack_writer *writer, uint8_t count)
+{
+ int ret = 0;
+
+ lttng_msgpack_assert(count <= MSGPACK_FIXMAP_MAX_COUNT);
+
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_FIXMAP_ID_MASK | count);
+ if (ret)
+ goto end;
+
+end:
+ return ret;
+}
+
+static inline int lttng_msgpack_encode_map16(
+ struct lttng_msgpack_writer *writer, uint16_t count)
+{
+ int ret;
+
+ lttng_msgpack_assert(count > MSGPACK_FIXMAP_MAX_COUNT);
+
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_MAP16_ID);
+ if (ret)
+ goto end;
+
+ ret = lttng_msgpack_append_u16(writer, count);
+ if (ret)
+ goto end;
+
+end:
+ return ret;
+}
+
+static inline int lttng_msgpack_encode_fixarray(
+ struct lttng_msgpack_writer *writer, uint8_t count)
+{
+ int ret = 0;
+
+ lttng_msgpack_assert(count <= MSGPACK_FIXARRAY_MAX_COUNT);
+
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_FIXARRAY_ID_MASK | count);
+ if (ret)
+ goto end;
+
+end:
+ return ret;
+}
+
+static inline int lttng_msgpack_encode_array16(
+ struct lttng_msgpack_writer *writer, uint16_t count)
+{
+ int ret;
+
+ lttng_msgpack_assert(count > MSGPACK_FIXARRAY_MAX_COUNT);
+
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_ARRAY16_ID);
+ if (ret)
+ goto end;
+
+ ret = lttng_msgpack_append_u16(writer, count);
+ if (ret)
+ goto end;
+
+end:
+ return ret;
+}
+
+static inline int lttng_msgpack_encode_fixstr(
+ struct lttng_msgpack_writer *writer,
+ const char *str,
+ uint8_t len)
+{
+ int ret;
+
+ lttng_msgpack_assert(len <= MSGPACK_FIXSTR_MAX_LENGTH);
+
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_FIXSTR_ID_MASK | len);
+ if (ret)
+ goto end;
+
+ ret = lttng_msgpack_append_buffer(writer, (uint8_t *) str, len);
+ if (ret)
+ goto end;
+
+end:
+ return ret;
+}
+
+static inline int lttng_msgpack_encode_str16(
+ struct lttng_msgpack_writer *writer,
+ const char *str,
+ uint16_t len)
+{
+ int ret;
+
+ lttng_msgpack_assert(len > MSGPACK_FIXSTR_MAX_LENGTH);
+
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_STR16_ID);
+ if (ret)
+ goto end;
+
+ ret = lttng_msgpack_append_u16(writer, len);
+ if (ret)
+ goto end;
+
+ ret = lttng_msgpack_append_buffer(writer, (uint8_t *) str, len);
+ if (ret)
+ goto end;
+
+end:
+ return ret;
+}
+
+int lttng_msgpack_begin_map(struct lttng_msgpack_writer *writer, size_t count)
+{
+ int ret;
+
+ if (count < 0 || count >= (1 << 16)) {
+ ret = -1;
+ goto end;
+ }
+
+ if (count <= MSGPACK_FIXMAP_MAX_COUNT)
+ ret = lttng_msgpack_encode_fixmap(writer, count);
+ else
+ ret = lttng_msgpack_encode_map16(writer, count);
+
+ writer->map_nesting++;
+end:
+ return ret;
+}
+
+int lttng_msgpack_end_map(struct lttng_msgpack_writer *writer)
+{
+ lttng_msgpack_assert(writer->map_nesting > 0);
+ writer->map_nesting--;
+ return 0;
+}
+
+int lttng_msgpack_begin_array(
+ struct lttng_msgpack_writer *writer, size_t count)
+{
+ int ret;
+
+ if (count < 0 || count >= (1 << 16)) {
+ ret = -1;
+ goto end;
+ }
+
+ if (count <= MSGPACK_FIXARRAY_MAX_COUNT)
+ ret = lttng_msgpack_encode_fixarray(writer, count);
+ else
+ ret = lttng_msgpack_encode_array16(writer, count);
+
+ writer->array_nesting++;
+end:
+ return ret;
+}
+
+int lttng_msgpack_end_array(struct lttng_msgpack_writer *writer)
+{
+ lttng_msgpack_assert(writer->array_nesting > 0);
+ writer->array_nesting--;
+ return 0;
+}
+
+int lttng_msgpack_write_str(struct lttng_msgpack_writer *writer,
+ const char *str)
+{
+ int ret;
+ size_t length = strlen(str);
+ if (length < 0 || length >= (1 << 16)) {
+ ret = -1;
+ goto end;
+ }
+
+ if (length <= MSGPACK_FIXSTR_MAX_LENGTH)
+ ret = lttng_msgpack_encode_fixstr(writer, str, length);
+ else
+ ret = lttng_msgpack_encode_str16(writer, str, length);
+
+end:
+ return ret;
+}
+
+int lttng_msgpack_write_nil(struct lttng_msgpack_writer *writer)
+{
+ return lttng_msgpack_append_u8(writer, MSGPACK_NIL_ID);
+}
+
+int lttng_msgpack_write_true(struct lttng_msgpack_writer *writer)
+{
+ return lttng_msgpack_append_u8(writer, MSGPACK_TRUE_ID);
+}
+
+int lttng_msgpack_write_false(struct lttng_msgpack_writer *writer)
+{
+ return lttng_msgpack_append_u8(writer, MSGPACK_FALSE_ID);
+}
+
+int lttng_msgpack_write_unsigned_integer(
+ struct lttng_msgpack_writer *writer, uint64_t value)
+{
+ int ret = 0;
+
+ if (value <= MSGPACK_FIXINT_MAX) {
+ ret = lttng_msgpack_append_u8(writer, (uint8_t) value);
+ if (ret)
+ goto end;
+ } else if (value <= UINT8_MAX) {
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_UINT8_ID);
+ if (ret)
+ goto end;
+
+ ret = lttng_msgpack_append_u8(writer, (uint8_t) value);
+ if (ret)
+ goto end;
+ } else if (value <= UINT16_MAX) {
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_UINT16_ID);
+ if (ret)
+ goto end;
+
+ ret = lttng_msgpack_append_u16(writer, (uint16_t) value);
+ if (ret)
+ goto end;
+ } else if (value <= UINT32_MAX) {
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_UINT32_ID);
+ if (ret)
+ goto end;
+
+ ret = lttng_msgpack_append_u32(writer, (uint32_t) value);
+ if (ret)
+ goto end;
+ } else {
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_UINT64_ID);
+ if (ret)
+ goto end;
+
+ ret = lttng_msgpack_append_u64(writer, value);
+ if (ret)
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+int lttng_msgpack_write_signed_integer(struct lttng_msgpack_writer *writer, int64_t value)
+{
+ int ret;
+
+ if (value >= MSGPACK_FIXINT_MIN && value <= MSGPACK_FIXINT_MAX){
+ ret = lttng_msgpack_append_i8(writer, (int8_t) value);
+ if (ret)
+ goto end;
+ } else if (value >= INT8_MIN && value <= INT8_MAX) {
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_INT8_ID);
+ if (ret)
+ goto end;
+
+ ret = lttng_msgpack_append_i8(writer, (int8_t) value);
+ if (ret)
+ goto end;
+ } else if (value >= INT16_MIN && value <= INT16_MAX) {
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_INT16_ID);
+ if (ret)
+ goto end;
+
+ ret = lttng_msgpack_append_i16(writer, (int16_t) value);
+ if (ret)
+ goto end;
+ } else if (value >= INT32_MIN && value <= INT32_MAX) {
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_INT32_ID);
+ if (ret)
+ goto end;
+
+ ret = lttng_msgpack_append_i32(writer, (int32_t) value);
+ if (ret)
+ goto end;
+ } else {
+ ret = lttng_msgpack_append_u8(writer, MSGPACK_INT64_ID);
+ if (ret)
+ goto end;
+
+ ret = lttng_msgpack_append_i64(writer, value);
+ if (ret)
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+int lttng_msgpack_write_double(struct lttng_msgpack_writer *writer, double value)
+{
+ return lttng_msgpack_encode_f64(writer, value);
+}
+
+void lttng_msgpack_writer_init(struct lttng_msgpack_writer *writer,
+ uint8_t *buffer, size_t size)
+{
+ lttng_msgpack_assert(buffer);
+ lttng_msgpack_assert(size >= 0);
+
+ writer->buffer = buffer;
+ writer->write_pos = buffer;
+ writer->end_write_pos = buffer + size;
+
+ writer->array_nesting = 0;
+ writer->map_nesting = 0;
+}
+
+void lttng_msgpack_writer_fini(struct lttng_msgpack_writer *writer)
+{
+ memset(writer, 0, sizeof(*writer));
+}