diff options
Diffstat (limited to 'drivers/soc/qcom/qmi_encdec.c')
| -rw-r--r-- | drivers/soc/qcom/qmi_encdec.c | 816 |
1 files changed, 816 insertions, 0 deletions
diff --git a/drivers/soc/qcom/qmi_encdec.c b/drivers/soc/qcom/qmi_encdec.c new file mode 100644 index 000000000..5c7161b18 --- /dev/null +++ b/drivers/soc/qcom/qmi_encdec.c @@ -0,0 +1,816 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved. + * Copyright (C) 2017 Linaro Ltd. + */ +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/soc/qcom/qmi.h> + +#define QMI_ENCDEC_ENCODE_TLV(type, length, p_dst) do { \ + *p_dst++ = type; \ + *p_dst++ = ((u8)((length) & 0xFF)); \ + *p_dst++ = ((u8)(((length) >> 8) & 0xFF)); \ +} while (0) + +#define QMI_ENCDEC_DECODE_TLV(p_type, p_length, p_src) do { \ + *p_type = (u8)*p_src++; \ + *p_length = (u8)*p_src++; \ + *p_length |= ((u8)*p_src) << 8; \ +} while (0) + +#define QMI_ENCDEC_ENCODE_N_BYTES(p_dst, p_src, size) \ +do { \ + memcpy(p_dst, p_src, size); \ + p_dst = (u8 *)p_dst + size; \ + p_src = (u8 *)p_src + size; \ +} while (0) + +#define QMI_ENCDEC_DECODE_N_BYTES(p_dst, p_src, size) \ +do { \ + memcpy(p_dst, p_src, size); \ + p_dst = (u8 *)p_dst + size; \ + p_src = (u8 *)p_src + size; \ +} while (0) + +#define UPDATE_ENCODE_VARIABLES(temp_si, buf_dst, \ + encoded_bytes, tlv_len, encode_tlv, rc) \ +do { \ + buf_dst = (u8 *)buf_dst + rc; \ + encoded_bytes += rc; \ + tlv_len += rc; \ + temp_si = temp_si + 1; \ + encode_tlv = 1; \ +} while (0) + +#define UPDATE_DECODE_VARIABLES(buf_src, decoded_bytes, rc) \ +do { \ + buf_src = (u8 *)buf_src + rc; \ + decoded_bytes += rc; \ +} while (0) + +#define TLV_LEN_SIZE sizeof(u16) +#define TLV_TYPE_SIZE sizeof(u8) +#define OPTIONAL_TLV_TYPE_START 0x10 + +static int qmi_encode(const struct qmi_elem_info *ei_array, void *out_buf, + const void *in_c_struct, u32 out_buf_len, + int enc_level); + +static int qmi_decode(const struct qmi_elem_info *ei_array, void *out_c_struct, + const void *in_buf, u32 in_buf_len, int dec_level); + +/** + * 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. + * + * 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. + * + * Return: struct info of the next element that can be encoded. + */ +static const struct qmi_elem_info * +skip_to_next_elem(const struct qmi_elem_info *ei_array, int level) +{ + const struct qmi_elem_info *temp_ei = ei_array; + u8 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_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 error. + */ +static int qmi_calc_min_msg_len(const struct qmi_elem_info *ei_array, + int level) +{ + int min_msg_len = 0; + const struct qmi_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(u8) ? + sizeof(u8) : sizeof(u16)); + 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(u8) : sizeof(u16); + 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_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. + * + * 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 u8 - u64 or similar. This + * function returns the number of bytes of encoded information. + * + * Return: The number of bytes of encoded information. + */ +static int qmi_encode_basic_elem(void *buf_dst, const void *buf_src, + u32 elem_len, u32 elem_size) +{ + u32 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. + * + * 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. + * + * Return: The number of bytes of encoded information on success or negative + * errno on error. + */ +static int qmi_encode_struct_elem(const struct qmi_elem_info *ei_array, + void *buf_dst, const void *buf_src, + u32 elem_len, u32 out_buf_len, + int enc_level) +{ + int i, rc, encoded_bytes = 0; + const struct qmi_elem_info *temp_ei = ei_array; + + for (i = 0; i < elem_len; i++) { + rc = qmi_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. + * + * 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. + * + * Return: The number of bytes of encoded information on success or negative + * errno on error. + */ +static int qmi_encode_string_elem(const struct qmi_elem_info *ei_array, + void *buf_dst, const void *buf_src, + u32 out_buf_len, int enc_level) +{ + int rc; + int encoded_bytes = 0; + const struct qmi_elem_info *temp_ei = ei_array; + u32 string_len = 0; + u32 string_len_sz = 0; + + string_len = strlen(buf_src); + string_len_sz = temp_ei->elem_len <= U8_MAX ? + sizeof(u8) : sizeof(u16); + 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; + + return encoded_bytes; +} + +/** + * qmi_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: The number of bytes of encoded information on success or negative + * errno on error. + */ +static int qmi_encode(const struct qmi_elem_info *ei_array, void *out_buf, + const void *in_c_struct, u32 out_buf_len, + int enc_level) +{ + const struct qmi_elem_info *temp_ei = ei_array; + u8 opt_flag_value = 0; + u32 data_len_value = 0, data_len_sz; + u8 *buf_dst = (u8 *)out_buf; + u8 *tlv_pointer; + u32 tlv_len; + u8 tlv_type; + u32 encoded_bytes = 0; + const void *buf_src; + int encode_tlv = 0; + int rc; + + if (!ei_array) + return 0; + + 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->array_type == NO_ARRAY) { + data_len_value = 1; + } else if (temp_ei->array_type == 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(u8)); + 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(u8) ? + sizeof(u8) : sizeof(u16); + /* 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); + 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); + 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; + } + } + + return encoded_bytes; +} + +/** + * 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. + * + * 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 u8 - u64 or similar. This + * function returns the number of bytes of decoded information. + * + * Return: The total size of the decoded data elements, in bytes. + */ +static int qmi_decode_basic_elem(void *buf_dst, const void *buf_src, + u32 elem_len, u32 elem_size) +{ + u32 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 describing 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 information corresponding to + * this struct element. + * @dec_level: Depth of the nested structure from the main structure. + * + * 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. + * + * Return: The total size of the decoded data elements on success, negative + * errno on error. + */ +static int qmi_decode_struct_elem(const struct qmi_elem_info *ei_array, + void *buf_dst, const void *buf_src, + u32 elem_len, u32 tlv_len, + int dec_level) +{ + int i, rc, decoded_bytes = 0; + const struct qmi_elem_info *temp_ei = ei_array; + + for (i = 0; i < elem_len && decoded_bytes < tlv_len; i++) { + rc = qmi_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 describing 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 information corresponding to + * this string element. + * @dec_level: Depth of the string element from the main structure. + * + * 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. + * + * Return: The total size of the decoded data elements on success, negative + * errno on error. + */ +static int qmi_decode_string_elem(const struct qmi_elem_info *ei_array, + void *buf_dst, const void *buf_src, + u32 tlv_len, int dec_level) +{ + int rc; + int decoded_bytes = 0; + u32 string_len = 0; + u32 string_len_sz = 0; + const struct qmi_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(u8) : sizeof(u16); + 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; + + 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. + * + * 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. + * + * Return: Pointer to struct info, if found + */ +static const struct qmi_elem_info *find_ei(const struct qmi_elem_info *ei_array, + u32 type) +{ + const struct qmi_elem_info *temp_ei = ei_array; + + while (temp_ei->data_type != QMI_EOTI) { + if (temp_ei->tlv_type == (u8)type) + return temp_ei; + temp_ei = temp_ei + 1; + } + + return NULL; +} + +/** + * qmi_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: The number of bytes of decoded information on success, negative + * errno on error. + */ +static int qmi_decode(const struct qmi_elem_info *ei_array, void *out_c_struct, + const void *in_buf, u32 in_buf_len, + int dec_level) +{ + const struct qmi_elem_info *temp_ei = ei_array; + u8 opt_flag_value = 1; + u32 data_len_value = 0, data_len_sz = 0; + u8 *buf_dst = out_c_struct; + const u8 *tlv_pointer; + u32 tlv_len = 0; + u32 tlv_type; + u32 decoded_bytes = 0; + const void *buf_src = in_buf; + int rc; + + 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); + 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(u8)); + 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(u8) ? + sizeof(u8) : sizeof(u16); + rc = qmi_decode_basic_elem(&data_len_value, buf_src, + 1, data_len_sz); + memcpy(buf_dst, &data_len_value, sizeof(u32)); + 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->array_type == NO_ARRAY) { + data_len_value = 1; + } else if (temp_ei->array_type == 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); + 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; +} + +/** + * qmi_encode_message() - Encode C structure as QMI encoded message + * @type: Type of QMI message + * @msg_id: Message ID of the message + * @len: Passed as max length of the message, updated to actual size + * @txn_id: Transaction ID + * @ei: QMI message descriptor + * @c_struct: Reference to structure to encode + * + * Return: Buffer with encoded message, or negative ERR_PTR() on error + */ +void *qmi_encode_message(int type, unsigned int msg_id, size_t *len, + unsigned int txn_id, const struct qmi_elem_info *ei, + const void *c_struct) +{ + struct qmi_header *hdr; + ssize_t msglen = 0; + void *msg; + int ret; + + /* Check the possibility of a zero length QMI message */ + if (!c_struct) { + ret = qmi_calc_min_msg_len(ei, 1); + if (ret) { + pr_err("%s: Calc. len %d != 0, but NULL c_struct\n", + __func__, ret); + return ERR_PTR(-EINVAL); + } + } + + msg = kzalloc(sizeof(*hdr) + *len, GFP_KERNEL); + if (!msg) + return ERR_PTR(-ENOMEM); + + /* Encode message, if we have a message */ + if (c_struct) { + msglen = qmi_encode(ei, msg + sizeof(*hdr), c_struct, *len, 1); + if (msglen < 0) { + kfree(msg); + return ERR_PTR(msglen); + } + } + + hdr = msg; + hdr->type = type; + hdr->txn_id = txn_id; + hdr->msg_id = msg_id; + hdr->msg_len = msglen; + + *len = sizeof(*hdr) + msglen; + + return msg; +} +EXPORT_SYMBOL(qmi_encode_message); + +/** + * qmi_decode_message() - Decode QMI encoded message to C structure + * @buf: Buffer with encoded message + * @len: Amount of data in @buf + * @ei: QMI message descriptor + * @c_struct: Reference to structure to decode into + * + * Return: The number of bytes of decoded information on success, negative + * errno on error. + */ +int qmi_decode_message(const void *buf, size_t len, + const struct qmi_elem_info *ei, void *c_struct) +{ + if (!ei) + return -EINVAL; + + if (!c_struct || !buf || !len) + return -EINVAL; + + return qmi_decode(ei, c_struct, buf + sizeof(struct qmi_header), + len - sizeof(struct qmi_header), 1); +} +EXPORT_SYMBOL(qmi_decode_message); + +/* Common header in all QMI responses */ +const struct qmi_elem_info qmi_response_type_v01_ei[] = { + { + .data_type = QMI_SIGNED_2_BYTE_ENUM, + .elem_len = 1, + .elem_size = sizeof(u16), + .array_type = NO_ARRAY, + .tlv_type = QMI_COMMON_TLV_TYPE, + .offset = offsetof(struct qmi_response_type_v01, result), + .ei_array = NULL, + }, + { + .data_type = QMI_SIGNED_2_BYTE_ENUM, + .elem_len = 1, + .elem_size = sizeof(u16), + .array_type = NO_ARRAY, + .tlv_type = QMI_COMMON_TLV_TYPE, + .offset = offsetof(struct qmi_response_type_v01, error), + .ei_array = NULL, + }, + { + .data_type = QMI_EOTI, + .elem_len = 0, + .elem_size = 0, + .array_type = NO_ARRAY, + .tlv_type = QMI_COMMON_TLV_TYPE, + .offset = 0, + .ei_array = NULL, + }, +}; +EXPORT_SYMBOL(qmi_response_type_v01_ei); + +MODULE_DESCRIPTION("QMI encoder/decoder helper"); +MODULE_LICENSE("GPL v2"); |