soc: qcom: Add snapshot of QMI
This snapshot is taken as of msm-4.4 'commit <d2afad6a903b>
("Merge "ext4 crypto: enable HW based encryption with ICE"")'.
Fix the code style warnings and errors.
CRs-Fixed: 1079350
Change-Id: I7dfcaac6dd2f97b109793aee97db6e9951282194
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
diff --git a/lib/qmi_encdec.c b/lib/qmi_encdec.c
new file mode 100644
index 0000000..d7221d8
--- /dev/null
+++ b/lib/qmi_encdec.c
@@ -0,0 +1,877 @@
+/* Copyright (c) 2012-2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 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 <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/string.h>
+#include <linux/qmi_encdec.h>
+
+#include "qmi_encdec_priv.h"
+
+#define TLV_LEN_SIZE sizeof(uint16_t)
+#define TLV_TYPE_SIZE sizeof(uint8_t)
+#define OPTIONAL_TLV_TYPE_START 0x10
+
+#ifdef CONFIG_QMI_ENCDEC_DEBUG
+
+#define qmi_encdec_dump(prefix_str, buf, buf_len) do { \
+ const u8 *ptr = buf; \
+ int i, linelen, remaining = buf_len; \
+ int rowsize = 16, groupsize = 1; \
+ unsigned char linebuf[256]; \
+ for (i = 0; i < buf_len; i += rowsize) { \
+ linelen = min(remaining, rowsize); \
+ remaining -= linelen; \
+ hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, \
+ linebuf, sizeof(linebuf), false); \
+ pr_debug("%s: %s\n", prefix_str, linebuf); \
+ } \
+} while (0)
+
+#define QMI_ENCODE_LOG_MSG(buf, buf_len) \
+ qmi_encdec_dump("QMI_ENCODE_MSG", buf, buf_len)
+
+#define QMI_DECODE_LOG_MSG(buf, buf_len) \
+ qmi_encdec_dump("QMI_DECODE_MSG", buf, buf_len)
+
+#define QMI_ENCODE_LOG_ELEM(level, elem_len, elem_size, buf) do { \
+ pr_debug("QMI_ENCODE_ELEM lvl: %d, len: %d, size: %d\n", \
+ level, elem_len, elem_size); \
+ qmi_encdec_dump("QMI_ENCODE_ELEM", buf, (elem_len * elem_size)); \
+} while (0)
+
+#define QMI_DECODE_LOG_ELEM(level, elem_len, elem_size, buf) do { \
+ pr_debug("QMI_DECODE_ELEM lvl: %d, len: %d, size: %d\n", \
+ level, elem_len, elem_size); \
+ qmi_encdec_dump("QMI_DECODE_ELEM", buf, (elem_len * elem_size)); \
+} while (0)
+
+#define QMI_ENCODE_LOG_TLV(tlv_type, tlv_len) \
+ pr_debug("QMI_ENCODE_TLV type: %d, len: %d\n", tlv_type, tlv_len)
+
+#define QMI_DECODE_LOG_TLV(tlv_type, tlv_len) \
+ pr_debug("QMI_DECODE_TLV type: %d, len: %d\n", tlv_type, tlv_len)
+
+#else
+
+#define QMI_ENCODE_LOG_MSG(buf, buf_len) { }
+#define QMI_DECODE_LOG_MSG(buf, buf_len) { }
+#define QMI_ENCODE_LOG_ELEM(level, elem_len, elem_size, buf) { }
+#define QMI_DECODE_LOG_ELEM(level, elem_len, elem_size, buf) { }
+#define QMI_ENCODE_LOG_TLV(tlv_type, tlv_len) { }
+#define QMI_DECODE_LOG_TLV(tlv_type, tlv_len) { }
+
+#endif
+
+static int _qmi_kernel_encode(struct elem_info *ei_array,
+ void *out_buf, void *in_c_struct,
+ uint32_t out_buf_len, int enc_level);
+
+static int _qmi_kernel_decode(struct elem_info *ei_array,
+ void *out_c_struct,
+ void *in_buf, uint32_t in_buf_len,
+ int dec_level);
+static struct elem_info *skip_to_next_elem(struct elem_info *ei_array,
+ int level);
+
+/**
+ * qmi_calc_max_msg_len() - Calculate the maximum length of a QMI message
+ * @ei_array: Struct info array describing the structure.
+ * @level: Level to identify the depth of the nested structures.
+ *
+ * @return: expected maximum length of the QMI message or 0 on failure.
+ */
+static int qmi_calc_max_msg_len(struct elem_info *ei_array,
+ int level)
+{
+ int max_msg_len = 0;
+ struct elem_info *temp_ei;
+
+ if (!ei_array)
+ return max_msg_len;
+
+ for (temp_ei = ei_array; temp_ei->data_type != QMI_EOTI; temp_ei++) {
+ /* Flag to identify the optional element is not encoded */
+ if (temp_ei->data_type == QMI_OPT_FLAG)
+ continue;
+
+ if (temp_ei->data_type == QMI_DATA_LEN) {
+ max_msg_len += (temp_ei->elem_size == sizeof(uint8_t) ?
+ sizeof(uint8_t) : sizeof(uint16_t));
+ continue;
+ } else if (temp_ei->data_type == QMI_STRUCT) {
+ max_msg_len += (temp_ei->elem_len *
+ qmi_calc_max_msg_len(temp_ei->ei_array,
+ (level + 1)));
+ } else if (temp_ei->data_type == QMI_STRING) {
+ if (level > 1)
+ max_msg_len += temp_ei->elem_len <= U8_MAX ?
+ sizeof(uint8_t) : sizeof(uint16_t);
+ max_msg_len += temp_ei->elem_len * temp_ei->elem_size;
+ } else {
+ max_msg_len += (temp_ei->elem_len * temp_ei->elem_size);
+ }
+
+ /*
+ * Type & Length info. not prepended for elements in the
+ * nested structure.
+ */
+ if (level == 1)
+ max_msg_len += (TLV_TYPE_SIZE + TLV_LEN_SIZE);
+ }
+ return max_msg_len;
+}
+
+/**
+ * qmi_calc_min_msg_len() - Calculate the minimum length of a QMI message
+ * @ei_array: Struct info array describing the structure.
+ * @level: Level to identify the depth of the nested structures.
+ *
+ * @return: expected minimum length of the QMI message or 0 on failure.
+ */
+static int qmi_calc_min_msg_len(struct elem_info *ei_array,
+ int level)
+{
+ int min_msg_len = 0;
+ struct elem_info *temp_ei = ei_array;
+
+ if (!ei_array)
+ return min_msg_len;
+
+ while (temp_ei->data_type != QMI_EOTI) {
+ /* Optional elements do not count in minimum length */
+ if (temp_ei->data_type == QMI_OPT_FLAG) {
+ temp_ei = skip_to_next_elem(temp_ei, level);
+ continue;
+ }
+
+ if (temp_ei->data_type == QMI_DATA_LEN) {
+ min_msg_len += (temp_ei->elem_size == sizeof(uint8_t) ?
+ sizeof(uint8_t) : sizeof(uint16_t));
+ temp_ei++;
+ continue;
+ } else if (temp_ei->data_type == QMI_STRUCT) {
+ min_msg_len += qmi_calc_min_msg_len(temp_ei->ei_array,
+ (level + 1));
+ temp_ei++;
+ } else if (temp_ei->data_type == QMI_STRING) {
+ if (level > 1)
+ min_msg_len += temp_ei->elem_len <= U8_MAX ?
+ sizeof(uint8_t) : sizeof(uint16_t);
+ min_msg_len += temp_ei->elem_len * temp_ei->elem_size;
+ temp_ei++;
+ } else {
+ min_msg_len += (temp_ei->elem_len * temp_ei->elem_size);
+ temp_ei++;
+ }
+
+ /*
+ * Type & Length info. not prepended for elements in the
+ * nested structure.
+ */
+ if (level == 1)
+ min_msg_len += (TLV_TYPE_SIZE + TLV_LEN_SIZE);
+ }
+ return min_msg_len;
+}
+
+/**
+ * qmi_verify_max_msg_len() - Verify the maximum length of a QMI message
+ * @desc: Pointer to structure descriptor.
+ *
+ * @return: true if the maximum message length embedded in structure
+ * descriptor matches the calculated value, else false.
+ */
+bool qmi_verify_max_msg_len(struct msg_desc *desc)
+{
+ int calc_max_msg_len;
+
+ if (!desc)
+ return false;
+
+ calc_max_msg_len = qmi_calc_max_msg_len(desc->ei_array, 1);
+ if (calc_max_msg_len != desc->max_msg_len) {
+ pr_err("%s: Calc. len %d != Passed len %d\n",
+ __func__, calc_max_msg_len, desc->max_msg_len);
+ return false;
+ }
+ return true;
+}
+
+/**
+ * qmi_kernel_encode() - Encode to QMI message wire format
+ * @desc: Pointer to structure descriptor.
+ * @out_buf: Buffer to hold the encoded QMI message.
+ * @out_buf_len: Length of the out buffer.
+ * @in_c_struct: C Structure to be encoded.
+ *
+ * @return: size of encoded message on success, < 0 for error.
+ */
+int qmi_kernel_encode(struct msg_desc *desc,
+ void *out_buf, uint32_t out_buf_len,
+ void *in_c_struct)
+{
+ int enc_level = 1;
+ int ret, calc_max_msg_len, calc_min_msg_len;
+
+ if (!desc)
+ return -EINVAL;
+
+ /* Check the possibility of a zero length QMI message */
+ if (!in_c_struct) {
+ calc_min_msg_len = qmi_calc_min_msg_len(desc->ei_array, 1);
+ if (calc_min_msg_len) {
+ pr_err("%s: Calc. len %d != 0, but NULL in_c_struct\n",
+ __func__, calc_min_msg_len);
+ return -EINVAL;
+ } else {
+ return 0;
+ }
+ }
+
+ /*
+ * Not a zero-length message. Ensure the output buffer and
+ * element information array are not NULL.
+ */
+ if (!out_buf || !desc->ei_array)
+ return -EINVAL;
+
+ if (desc->max_msg_len < out_buf_len)
+ return -ETOOSMALL;
+
+ ret = _qmi_kernel_encode(desc->ei_array, out_buf,
+ in_c_struct, out_buf_len, enc_level);
+ if (ret == -ETOOSMALL) {
+ calc_max_msg_len = qmi_calc_max_msg_len(desc->ei_array, 1);
+ pr_err("%s: Calc. len %d != Out buf len %d\n",
+ __func__, calc_max_msg_len, out_buf_len);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(qmi_kernel_encode);
+
+/**
+ * qmi_encode_basic_elem() - Encodes elements of basic/primary data type
+ * @buf_dst: Buffer to store the encoded information.
+ * @buf_src: Buffer containing the elements to be encoded.
+ * @elem_len: Number of elements, in the buf_src, to be encoded.
+ * @elem_size: Size of a single instance of the element to be encoded.
+ *
+ * @return: number of bytes of encoded information.
+ *
+ * This function encodes the "elem_len" number of data elements, each of
+ * size "elem_size" bytes from the source buffer "buf_src" and stores the
+ * encoded information in the destination buffer "buf_dst". The elements are
+ * of primary data type which include uint8_t - uint64_t or similar. This
+ * function returns the number of bytes of encoded information.
+ */
+static int qmi_encode_basic_elem(void *buf_dst, void *buf_src,
+ uint32_t elem_len, uint32_t elem_size)
+{
+ uint32_t i, rc = 0;
+
+ for (i = 0; i < elem_len; i++) {
+ QMI_ENCDEC_ENCODE_N_BYTES(buf_dst, buf_src, elem_size);
+ rc += elem_size;
+ }
+
+ return rc;
+}
+
+/**
+ * qmi_encode_struct_elem() - Encodes elements of struct data type
+ * @ei_array: Struct info array descibing the struct element.
+ * @buf_dst: Buffer to store the encoded information.
+ * @buf_src: Buffer containing the elements to be encoded.
+ * @elem_len: Number of elements, in the buf_src, to be encoded.
+ * @out_buf_len: Available space in the encode buffer.
+ * @enc_level: Depth of the nested structure from the main structure.
+ *
+ * @return: Number of bytes of encoded information, on success.
+ * < 0 on error.
+ *
+ * This function encodes the "elem_len" number of struct elements, each of
+ * size "ei_array->elem_size" bytes from the source buffer "buf_src" and
+ * stores the encoded information in the destination buffer "buf_dst". The
+ * elements are of struct data type which includes any C structure. This
+ * function returns the number of bytes of encoded information.
+ */
+static int qmi_encode_struct_elem(struct elem_info *ei_array,
+ void *buf_dst, void *buf_src,
+ uint32_t elem_len, uint32_t out_buf_len,
+ int enc_level)
+{
+ int i, rc, encoded_bytes = 0;
+ struct elem_info *temp_ei = ei_array;
+
+ for (i = 0; i < elem_len; i++) {
+ rc = _qmi_kernel_encode(temp_ei->ei_array, buf_dst, buf_src,
+ (out_buf_len - encoded_bytes),
+ enc_level);
+ if (rc < 0) {
+ pr_err("%s: STRUCT Encode failure\n", __func__);
+ return rc;
+ }
+ buf_dst = buf_dst + rc;
+ buf_src = buf_src + temp_ei->elem_size;
+ encoded_bytes += rc;
+ }
+
+ return encoded_bytes;
+}
+
+/**
+ * qmi_encode_string_elem() - Encodes elements of string data type
+ * @ei_array: Struct info array descibing the string element.
+ * @buf_dst: Buffer to store the encoded information.
+ * @buf_src: Buffer containing the elements to be encoded.
+ * @out_buf_len: Available space in the encode buffer.
+ * @enc_level: Depth of the string element from the main structure.
+ *
+ * @return: Number of bytes of encoded information, on success.
+ * < 0 on error.
+ *
+ * This function encodes a string element of maximum length "ei_array->elem_len"
+ * bytes from the source buffer "buf_src" and stores the encoded information in
+ * the destination buffer "buf_dst". This function returns the number of bytes
+ * of encoded information.
+ */
+static int qmi_encode_string_elem(struct elem_info *ei_array,
+ void *buf_dst, void *buf_src,
+ uint32_t out_buf_len, int enc_level)
+{
+ int rc;
+ int encoded_bytes = 0;
+ struct elem_info *temp_ei = ei_array;
+ uint32_t string_len = 0;
+ uint32_t string_len_sz = 0;
+
+ string_len = strlen(buf_src);
+ string_len_sz = temp_ei->elem_len <= U8_MAX ?
+ sizeof(uint8_t) : sizeof(uint16_t);
+ if (string_len > temp_ei->elem_len) {
+ pr_err("%s: String to be encoded is longer - %d > %d\n",
+ __func__, string_len, temp_ei->elem_len);
+ return -EINVAL;
+ }
+
+ if (enc_level == 1) {
+ if (string_len + TLV_LEN_SIZE + TLV_TYPE_SIZE >
+ out_buf_len) {
+ pr_err("%s: Output len %d > Out Buf len %d\n",
+ __func__, string_len, out_buf_len);
+ return -ETOOSMALL;
+ }
+ } else {
+ if (string_len + string_len_sz > out_buf_len) {
+ pr_err("%s: Output len %d > Out Buf len %d\n",
+ __func__, string_len, out_buf_len);
+ return -ETOOSMALL;
+ }
+ rc = qmi_encode_basic_elem(buf_dst, &string_len,
+ 1, string_len_sz);
+ encoded_bytes += rc;
+ }
+
+ rc = qmi_encode_basic_elem(buf_dst + encoded_bytes, buf_src,
+ string_len, temp_ei->elem_size);
+ encoded_bytes += rc;
+ QMI_ENCODE_LOG_ELEM(enc_level, string_len, temp_ei->elem_size, buf_src);
+ return encoded_bytes;
+}
+
+/**
+ * skip_to_next_elem() - Skip to next element in the structure to be encoded
+ * @ei_array: Struct info describing the element to be skipped.
+ * @level: Depth level of encoding/decoding to identify nested structures.
+ *
+ * @return: Struct info of the next element that can be encoded.
+ *
+ * This function is used while encoding optional elements. If the flag
+ * corresponding to an optional element is not set, then encoding the
+ * optional element can be skipped. This function can be used to perform
+ * that operation.
+ */
+static struct elem_info *skip_to_next_elem(struct elem_info *ei_array,
+ int level)
+{
+ struct elem_info *temp_ei = ei_array;
+ uint8_t tlv_type;
+
+ if (level > 1) {
+ temp_ei = temp_ei + 1;
+ } else {
+ do {
+ tlv_type = temp_ei->tlv_type;
+ temp_ei = temp_ei + 1;
+ } while (tlv_type == temp_ei->tlv_type);
+ }
+
+ return temp_ei;
+}
+
+/**
+ * _qmi_kernel_encode() - Core Encode Function
+ * @ei_array: Struct info array describing the structure to be encoded.
+ * @out_buf: Buffer to hold the encoded QMI message.
+ * @in_c_struct: Pointer to the C structure to be encoded.
+ * @out_buf_len: Available space in the encode buffer.
+ * @enc_level: Encode level to indicate the depth of the nested structure,
+ * within the main structure, being encoded.
+ *
+ * @return: Number of bytes of encoded information, on success.
+ * < 0 on error.
+ */
+static int _qmi_kernel_encode(struct elem_info *ei_array,
+ void *out_buf, void *in_c_struct,
+ uint32_t out_buf_len, int enc_level)
+{
+ struct elem_info *temp_ei = ei_array;
+ uint8_t opt_flag_value = 0;
+ uint32_t data_len_value = 0, data_len_sz;
+ uint8_t *buf_dst = (uint8_t *)out_buf;
+ uint8_t *tlv_pointer;
+ uint32_t tlv_len;
+ uint8_t tlv_type;
+ uint32_t encoded_bytes = 0;
+ void *buf_src;
+ int encode_tlv = 0;
+ int rc;
+
+ tlv_pointer = buf_dst;
+ tlv_len = 0;
+ if (enc_level == 1)
+ buf_dst = buf_dst + (TLV_LEN_SIZE + TLV_TYPE_SIZE);
+
+ while (temp_ei->data_type != QMI_EOTI) {
+ buf_src = in_c_struct + temp_ei->offset;
+ tlv_type = temp_ei->tlv_type;
+
+ if (temp_ei->is_array == NO_ARRAY) {
+ data_len_value = 1;
+ } else if (temp_ei->is_array == STATIC_ARRAY) {
+ data_len_value = temp_ei->elem_len;
+ } else if (data_len_value <= 0 ||
+ temp_ei->elem_len < data_len_value) {
+ pr_err("%s: Invalid data length\n", __func__);
+ return -EINVAL;
+ }
+
+ switch (temp_ei->data_type) {
+ case QMI_OPT_FLAG:
+ rc = qmi_encode_basic_elem(&opt_flag_value, buf_src,
+ 1, sizeof(uint8_t));
+ if (opt_flag_value)
+ temp_ei = temp_ei + 1;
+ else
+ temp_ei = skip_to_next_elem(temp_ei, enc_level);
+ break;
+
+ case QMI_DATA_LEN:
+ memcpy(&data_len_value, buf_src, temp_ei->elem_size);
+ data_len_sz = temp_ei->elem_size == sizeof(uint8_t) ?
+ sizeof(uint8_t) : sizeof(uint16_t);
+ /* Check to avoid out of range buffer access */
+ if ((data_len_sz + encoded_bytes + TLV_LEN_SIZE +
+ TLV_TYPE_SIZE) > out_buf_len) {
+ pr_err("%s: Too Small Buffer @DATA_LEN\n",
+ __func__);
+ return -ETOOSMALL;
+ }
+ rc = qmi_encode_basic_elem(buf_dst, &data_len_value,
+ 1, data_len_sz);
+ UPDATE_ENCODE_VARIABLES(temp_ei, buf_dst,
+ encoded_bytes, tlv_len, encode_tlv, rc);
+ if (!data_len_value)
+ temp_ei = skip_to_next_elem(temp_ei, enc_level);
+ else
+ encode_tlv = 0;
+ break;
+
+ case QMI_UNSIGNED_1_BYTE:
+ case QMI_UNSIGNED_2_BYTE:
+ case QMI_UNSIGNED_4_BYTE:
+ case QMI_UNSIGNED_8_BYTE:
+ case QMI_SIGNED_2_BYTE_ENUM:
+ case QMI_SIGNED_4_BYTE_ENUM:
+ /* Check to avoid out of range buffer access */
+ if (((data_len_value * temp_ei->elem_size) +
+ encoded_bytes + TLV_LEN_SIZE + TLV_TYPE_SIZE) >
+ out_buf_len) {
+ pr_err("%s: Too Small Buffer @data_type:%d\n",
+ __func__, temp_ei->data_type);
+ return -ETOOSMALL;
+ }
+ rc = qmi_encode_basic_elem(buf_dst, buf_src,
+ data_len_value, temp_ei->elem_size);
+ QMI_ENCODE_LOG_ELEM(enc_level, data_len_value,
+ temp_ei->elem_size, buf_src);
+ UPDATE_ENCODE_VARIABLES(temp_ei, buf_dst,
+ encoded_bytes, tlv_len, encode_tlv, rc);
+ break;
+
+ case QMI_STRUCT:
+ rc = qmi_encode_struct_elem(temp_ei, buf_dst, buf_src,
+ data_len_value, (out_buf_len - encoded_bytes),
+ (enc_level + 1));
+ if (rc < 0)
+ return rc;
+ UPDATE_ENCODE_VARIABLES(temp_ei, buf_dst,
+ encoded_bytes, tlv_len, encode_tlv, rc);
+ break;
+
+ case QMI_STRING:
+ rc = qmi_encode_string_elem(temp_ei, buf_dst, buf_src,
+ out_buf_len - encoded_bytes, enc_level);
+ if (rc < 0)
+ return rc;
+ UPDATE_ENCODE_VARIABLES(temp_ei, buf_dst,
+ encoded_bytes, tlv_len, encode_tlv, rc);
+ break;
+ default:
+ pr_err("%s: Unrecognized data type\n", __func__);
+ return -EINVAL;
+
+ }
+
+ if (encode_tlv && enc_level == 1) {
+ QMI_ENCDEC_ENCODE_TLV(tlv_type, tlv_len, tlv_pointer);
+ QMI_ENCODE_LOG_TLV(tlv_type, tlv_len);
+ encoded_bytes += (TLV_TYPE_SIZE + TLV_LEN_SIZE);
+ tlv_pointer = buf_dst;
+ tlv_len = 0;
+ buf_dst = buf_dst + TLV_LEN_SIZE + TLV_TYPE_SIZE;
+ encode_tlv = 0;
+ }
+ }
+ QMI_ENCODE_LOG_MSG(out_buf, encoded_bytes);
+ return encoded_bytes;
+}
+
+/**
+ * qmi_kernel_decode() - Decode to C Structure format
+ * @desc: Pointer to structure descriptor.
+ * @out_c_struct: Buffer to hold the decoded C structure.
+ * @in_buf: Buffer containg the QMI message to be decoded.
+ * @in_buf_len: Length of the incoming QMI message.
+ *
+ * @return: 0 on success, < 0 on error.
+ */
+int qmi_kernel_decode(struct msg_desc *desc, void *out_c_struct,
+ void *in_buf, uint32_t in_buf_len)
+{
+ int dec_level = 1;
+ int rc = 0;
+
+ if (!desc || !desc->ei_array)
+ return -EINVAL;
+
+ if (!out_c_struct || !in_buf || !in_buf_len)
+ return -EINVAL;
+
+ if (desc->max_msg_len < in_buf_len)
+ return -EINVAL;
+
+ rc = _qmi_kernel_decode(desc->ei_array, out_c_struct,
+ in_buf, in_buf_len, dec_level);
+ if (rc < 0)
+ return rc;
+ else
+ return 0;
+}
+EXPORT_SYMBOL(qmi_kernel_decode);
+
+/**
+ * qmi_decode_basic_elem() - Decodes elements of basic/primary data type
+ * @buf_dst: Buffer to store the decoded element.
+ * @buf_src: Buffer containing the elements in QMI wire format.
+ * @elem_len: Number of elements to be decoded.
+ * @elem_size: Size of a single instance of the element to be decoded.
+ *
+ * @return: Total size of the decoded data elements, in bytes.
+ *
+ * This function decodes the "elem_len" number of elements in QMI wire format,
+ * each of size "elem_size" bytes from the source buffer "buf_src" and stores
+ * the decoded elements in the destination buffer "buf_dst". The elements are
+ * of primary data type which include uint8_t - uint64_t or similar. This
+ * function returns the number of bytes of decoded information.
+ */
+static int qmi_decode_basic_elem(void *buf_dst, void *buf_src,
+ uint32_t elem_len, uint32_t elem_size)
+{
+ uint32_t i, rc = 0;
+
+ for (i = 0; i < elem_len; i++) {
+ QMI_ENCDEC_DECODE_N_BYTES(buf_dst, buf_src, elem_size);
+ rc += elem_size;
+ }
+
+ return rc;
+}
+
+/**
+ * qmi_decode_struct_elem() - Decodes elements of struct data type
+ * @ei_array: Struct info array descibing the struct element.
+ * @buf_dst: Buffer to store the decoded element.
+ * @buf_src: Buffer containing the elements in QMI wire format.
+ * @elem_len: Number of elements to be decoded.
+ * @tlv_len: Total size of the encoded inforation corresponding to
+ * this struct element.
+ * @dec_level: Depth of the nested structure from the main structure.
+ *
+ * @return: Total size of the decoded data elements, on success.
+ * < 0 on error.
+ *
+ * This function decodes the "elem_len" number of elements in QMI wire format,
+ * each of size "(tlv_len/elem_len)" bytes from the source buffer "buf_src"
+ * and stores the decoded elements in the destination buffer "buf_dst". The
+ * elements are of struct data type which includes any C structure. This
+ * function returns the number of bytes of decoded information.
+ */
+static int qmi_decode_struct_elem(struct elem_info *ei_array, void *buf_dst,
+ void *buf_src, uint32_t elem_len,
+ uint32_t tlv_len, int dec_level)
+{
+ int i, rc, decoded_bytes = 0;
+ struct elem_info *temp_ei = ei_array;
+
+ for (i = 0; i < elem_len && decoded_bytes < tlv_len; i++) {
+ rc = _qmi_kernel_decode(temp_ei->ei_array, buf_dst, buf_src,
+ (tlv_len - decoded_bytes), dec_level);
+ if (rc < 0)
+ return rc;
+ buf_src = buf_src + rc;
+ buf_dst = buf_dst + temp_ei->elem_size;
+ decoded_bytes += rc;
+ }
+
+ if ((dec_level <= 2 && decoded_bytes != tlv_len) ||
+ (dec_level > 2 && (i < elem_len || decoded_bytes > tlv_len))) {
+ pr_err("%s: Fault in decoding: dl(%d), db(%d), tl(%d), i(%d), el(%d)\n",
+ __func__, dec_level, decoded_bytes, tlv_len,
+ i, elem_len);
+ return -EFAULT;
+ }
+ return decoded_bytes;
+}
+
+/**
+ * qmi_decode_string_elem() - Decodes elements of string data type
+ * @ei_array: Struct info array descibing the string element.
+ * @buf_dst: Buffer to store the decoded element.
+ * @buf_src: Buffer containing the elements in QMI wire format.
+ * @tlv_len: Total size of the encoded inforation corresponding to
+ * this string element.
+ * @dec_level: Depth of the string element from the main structure.
+ *
+ * @return: Total size of the decoded data elements, on success.
+ * < 0 on error.
+ *
+ * This function decodes the string element of maximum length
+ * "ei_array->elem_len" from the source buffer "buf_src" and puts it into
+ * the destination buffer "buf_dst". This function returns number of bytes
+ * decoded from the input buffer.
+ */
+static int qmi_decode_string_elem(struct elem_info *ei_array, void *buf_dst,
+ void *buf_src, uint32_t tlv_len,
+ int dec_level)
+{
+ int rc;
+ int decoded_bytes = 0;
+ uint32_t string_len = 0;
+ uint32_t string_len_sz = 0;
+ struct elem_info *temp_ei = ei_array;
+
+ if (dec_level == 1) {
+ string_len = tlv_len;
+ } else {
+ string_len_sz = temp_ei->elem_len <= U8_MAX ?
+ sizeof(uint8_t) : sizeof(uint16_t);
+ rc = qmi_decode_basic_elem(&string_len, buf_src,
+ 1, string_len_sz);
+ decoded_bytes += rc;
+ }
+
+ if (string_len > temp_ei->elem_len) {
+ pr_err("%s: String len %d > Max Len %d\n",
+ __func__, string_len, temp_ei->elem_len);
+ return -ETOOSMALL;
+ } else if (string_len > tlv_len) {
+ pr_err("%s: String len %d > Input Buffer Len %d\n",
+ __func__, string_len, tlv_len);
+ return -EFAULT;
+ }
+
+ rc = qmi_decode_basic_elem(buf_dst, buf_src + decoded_bytes,
+ string_len, temp_ei->elem_size);
+ *((char *)buf_dst + string_len) = '\0';
+ decoded_bytes += rc;
+ QMI_DECODE_LOG_ELEM(dec_level, string_len, temp_ei->elem_size, buf_dst);
+ return decoded_bytes;
+}
+
+/**
+ * find_ei() - Find element info corresponding to TLV Type
+ * @ei_array: Struct info array of the message being decoded.
+ * @type: TLV Type of the element being searched.
+ *
+ * @return: Pointer to struct info, if found
+ *
+ * Every element that got encoded in the QMI message will have a type
+ * information associated with it. While decoding the QMI message,
+ * this function is used to find the struct info regarding the element
+ * that corresponds to the type being decoded.
+ */
+static struct elem_info *find_ei(struct elem_info *ei_array,
+ uint32_t type)
+{
+ struct elem_info *temp_ei = ei_array;
+
+ while (temp_ei->data_type != QMI_EOTI) {
+ if (temp_ei->tlv_type == (uint8_t)type)
+ return temp_ei;
+ temp_ei = temp_ei + 1;
+ }
+ return NULL;
+}
+
+/**
+ * _qmi_kernel_decode() - Core Decode Function
+ * @ei_array: Struct info array describing the structure to be decoded.
+ * @out_c_struct: Buffer to hold the decoded C struct
+ * @in_buf: Buffer containing the QMI message to be decoded
+ * @in_buf_len: Length of the QMI message to be decoded
+ * @dec_level: Decode level to indicate the depth of the nested structure,
+ * within the main structure, being decoded
+ *
+ * @return: Number of bytes of decoded information, on success
+ * < 0 on error.
+ */
+static int _qmi_kernel_decode(struct elem_info *ei_array,
+ void *out_c_struct,
+ void *in_buf, uint32_t in_buf_len,
+ int dec_level)
+{
+ struct elem_info *temp_ei = ei_array;
+ uint8_t opt_flag_value = 1;
+ uint32_t data_len_value = 0, data_len_sz = 0;
+ uint8_t *buf_dst = out_c_struct;
+ uint8_t *tlv_pointer;
+ uint32_t tlv_len = 0;
+ uint32_t tlv_type;
+ uint32_t decoded_bytes = 0;
+ void *buf_src = in_buf;
+ int rc;
+
+ QMI_DECODE_LOG_MSG(in_buf, in_buf_len);
+ while (decoded_bytes < in_buf_len) {
+ if (dec_level >= 2 && temp_ei->data_type == QMI_EOTI)
+ return decoded_bytes;
+
+ if (dec_level == 1) {
+ tlv_pointer = buf_src;
+ QMI_ENCDEC_DECODE_TLV(&tlv_type,
+ &tlv_len, tlv_pointer);
+ QMI_DECODE_LOG_TLV(tlv_type, tlv_len);
+ buf_src += (TLV_TYPE_SIZE + TLV_LEN_SIZE);
+ decoded_bytes += (TLV_TYPE_SIZE + TLV_LEN_SIZE);
+ temp_ei = find_ei(ei_array, tlv_type);
+ if (!temp_ei && (tlv_type < OPTIONAL_TLV_TYPE_START)) {
+ pr_err("%s: Inval element info\n", __func__);
+ return -EINVAL;
+ } else if (!temp_ei) {
+ UPDATE_DECODE_VARIABLES(buf_src,
+ decoded_bytes, tlv_len);
+ continue;
+ }
+ } else {
+ /*
+ * No length information for elements in nested
+ * structures. So use remaining decodable buffer space.
+ */
+ tlv_len = in_buf_len - decoded_bytes;
+ }
+
+ buf_dst = out_c_struct + temp_ei->offset;
+ if (temp_ei->data_type == QMI_OPT_FLAG) {
+ memcpy(buf_dst, &opt_flag_value, sizeof(uint8_t));
+ temp_ei = temp_ei + 1;
+ buf_dst = out_c_struct + temp_ei->offset;
+ }
+
+ if (temp_ei->data_type == QMI_DATA_LEN) {
+ data_len_sz = temp_ei->elem_size == sizeof(uint8_t) ?
+ sizeof(uint8_t) : sizeof(uint16_t);
+ rc = qmi_decode_basic_elem(&data_len_value, buf_src,
+ 1, data_len_sz);
+ memcpy(buf_dst, &data_len_value, sizeof(uint32_t));
+ temp_ei = temp_ei + 1;
+ buf_dst = out_c_struct + temp_ei->offset;
+ tlv_len -= data_len_sz;
+ UPDATE_DECODE_VARIABLES(buf_src, decoded_bytes, rc);
+ }
+
+ if (temp_ei->is_array == NO_ARRAY) {
+ data_len_value = 1;
+ } else if (temp_ei->is_array == STATIC_ARRAY) {
+ data_len_value = temp_ei->elem_len;
+ } else if (data_len_value > temp_ei->elem_len) {
+ pr_err("%s: Data len %d > max spec %d\n",
+ __func__, data_len_value, temp_ei->elem_len);
+ return -ETOOSMALL;
+ }
+
+ switch (temp_ei->data_type) {
+ case QMI_UNSIGNED_1_BYTE:
+ case QMI_UNSIGNED_2_BYTE:
+ case QMI_UNSIGNED_4_BYTE:
+ case QMI_UNSIGNED_8_BYTE:
+ case QMI_SIGNED_2_BYTE_ENUM:
+ case QMI_SIGNED_4_BYTE_ENUM:
+ rc = qmi_decode_basic_elem(buf_dst, buf_src,
+ data_len_value, temp_ei->elem_size);
+ QMI_DECODE_LOG_ELEM(dec_level, data_len_value,
+ temp_ei->elem_size, buf_dst);
+ UPDATE_DECODE_VARIABLES(buf_src, decoded_bytes, rc);
+ break;
+
+ case QMI_STRUCT:
+ rc = qmi_decode_struct_elem(temp_ei, buf_dst, buf_src,
+ data_len_value, tlv_len, (dec_level + 1));
+ if (rc < 0)
+ return rc;
+ UPDATE_DECODE_VARIABLES(buf_src, decoded_bytes, rc);
+ break;
+
+ case QMI_STRING:
+ rc = qmi_decode_string_elem(temp_ei, buf_dst, buf_src,
+ tlv_len, dec_level);
+ if (rc < 0)
+ return rc;
+ UPDATE_DECODE_VARIABLES(buf_src, decoded_bytes, rc);
+ break;
+
+ default:
+ pr_err("%s: Unrecognized data type\n", __func__);
+ return -EINVAL;
+ }
+ temp_ei = temp_ei + 1;
+ }
+ return decoded_bytes;
+}
+MODULE_DESCRIPTION("QMI kernel enc/dec");
+MODULE_LICENSE("GPL v2");