Hung-Te Lin | 6eaaafa | 2014-02-21 16:21:00 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2013 The Chromium OS Authors. All rights reserved. |
| 3 | * Use of this source code is governed by a BSD-style license that can be |
| 4 | * found in the LICENSE file. |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #ifndef __LIB_VPD__ |
| 9 | #define __LIB_VPD__ |
| 10 | |
| 11 | #include <inttypes.h> |
| 12 | |
| 13 | enum { |
| 14 | VPD_OK = 0, |
| 15 | VPD_FAIL, |
| 16 | }; |
| 17 | |
| 18 | enum { |
| 19 | VPD_TYPE_TERMINATOR = 0, |
| 20 | VPD_TYPE_STRING, |
| 21 | VPD_TYPE_INFO = 0xfe, |
| 22 | VPD_TYPE_IMPLICIT_TERMINATOR = 0xff, |
| 23 | }; |
| 24 | |
| 25 | enum { |
| 26 | VPD_AS_LONG_AS = -1, |
| 27 | }; |
| 28 | |
| 29 | enum { /* export_type */ |
| 30 | VPD_EXPORT_KEY_VALUE = 1, |
| 31 | VPD_EXPORT_VALUE, |
| 32 | VPD_EXPORT_AS_PARAMETER, |
| 33 | }; |
| 34 | |
| 35 | /* Callback for decodeVpdString to invoke. */ |
| 36 | typedef int VpdDecodeCallback(const uint8_t *key, int32_t key_len, |
| 37 | const uint8_t *value, int32_t value_len, |
| 38 | void *arg); |
| 39 | |
| 40 | /* Container data types */ |
| 41 | struct StringPair { |
| 42 | uint8_t *key; |
| 43 | uint8_t *value; |
| 44 | int pad_len; |
| 45 | int filter_out; /* TRUE means not exported. */ |
| 46 | struct StringPair *next; |
| 47 | }; |
| 48 | |
| 49 | struct PairContainer { |
| 50 | struct StringPair *first; |
| 51 | }; |
| 52 | |
| 53 | |
| 54 | /*********************************************************************** |
| 55 | * Encode and decode VPD entries |
| 56 | ***********************************************************************/ |
| 57 | |
| 58 | /* Encodes the len into multiple bytes with the following format. |
| 59 | * |
| 60 | * 7 6 ............ 0 |
| 61 | * +----+------------------+ |
| 62 | * |More| Length | ... |
| 63 | * +----+------------------+ |
| 64 | * |
| 65 | * The encode_buf points to the actual position we are going to store. |
| 66 | * encoded_len will return the exact bytes we encoded in this function. |
| 67 | * Returns fail if the buffer is not long enough. |
| 68 | */ |
| 69 | int encodeLen( |
| 70 | const int32_t len, |
| 71 | uint8_t *encode_buf, |
| 72 | const int32_t max_len, |
| 73 | int32_t *encoded_len); |
| 74 | |
| 75 | /* Given an encoded string, this functions decodes the length field which varies |
| 76 | * from 1 byte to many bytes. |
| 77 | * |
| 78 | * The in points the actual byte going to be decoded. The *length returns |
| 79 | * the decoded length field. The number of consumed bytes will be stroed in |
| 80 | * decoded_len. |
| 81 | * |
| 82 | * Returns VPD_FAIL if more bit is 1, but actually reaches the end of string. |
| 83 | */ |
| 84 | int decodeLen( |
| 85 | const int32_t max_len, |
| 86 | const uint8_t *in, |
| 87 | int32_t *length, |
| 88 | int32_t *decoded_len); |
| 89 | |
| 90 | |
| 91 | /* Encodes the terminator. |
| 92 | * When calling, the output_buf should point to the start of buffer while |
| 93 | * *generated_len should contain how many bytes exist in buffer now. |
| 94 | * After return, *generated_len would be plused the number of bytes generated |
| 95 | * in this function. |
| 96 | */ |
| 97 | int encodeVpdTerminator( |
| 98 | const int max_buffer_len, |
| 99 | uint8_t *output_buf, |
| 100 | int *generated_len); |
| 101 | |
| 102 | /* Encodes the given type/key/value pair into buffer. |
| 103 | * |
| 104 | * The pad_value_len is used to control the output value length. |
| 105 | * When pad_value_len > 0, the value is outputted into fixed length (pad \0 |
| 106 | * if the value is shorter). Truncated if too long. |
| 107 | * pad_value_len == VPD_NO_LIMIT, output the value as long as possible. |
| 108 | * This is useful when we want to fix the structure layout at beginning. |
| 109 | * |
| 110 | * The encoded string will be stored in output_buf. If it is longer than |
| 111 | * max_buffer_len, this function returns fail. If the buffer is long enough, |
| 112 | * the generated_len will be updated. |
| 113 | * |
| 114 | * When calling, the output_buf should point to the start of buffer while |
| 115 | * *generated_len should contain how many bytes exist in buffer now. |
| 116 | * After return, *generated_len would be plused the number of bytes generated |
| 117 | * in this function. |
| 118 | * |
| 119 | * The initial value of *generated_len can be non-zero, so that this value |
| 120 | * can be used between multiple calls to encodeVpd2Pair(). |
| 121 | */ |
| 122 | int encodeVpdString( |
| 123 | const uint8_t *key, |
| 124 | const uint8_t *value, |
| 125 | const int pad_value_len, |
| 126 | const int max_buffer_len, |
| 127 | uint8_t *output_buf, |
| 128 | int *generated_len); |
| 129 | |
| 130 | |
| 131 | /* Given the encoded string, this function invokes callback with extracted |
| 132 | * (key, value). The *consumed will be plused the number of bytes consumed in |
| 133 | * this function. |
| 134 | * |
| 135 | * The input_buf points to the first byte of the input buffer. |
| 136 | * |
| 137 | * The *consumed starts from 0, which is actually the next byte to be decoded. |
| 138 | * It can be non-zero to be used in multiple calls. |
| 139 | * |
| 140 | * If one entry is successfully decoded, sends it to callback and returns the |
| 141 | * result. |
| 142 | */ |
| 143 | int decodeVpdString( |
| 144 | const int32_t max_len, |
| 145 | const uint8_t *input_buf, |
| 146 | int32_t *consumed, |
| 147 | VpdDecodeCallback callback, |
| 148 | void *callback_arg); |
| 149 | |
| 150 | /*********************************************************************** |
| 151 | * Container helpers |
| 152 | ***********************************************************************/ |
| 153 | void initContainer(struct PairContainer *container); |
| 154 | |
| 155 | struct StringPair *findString(struct PairContainer *container, |
| 156 | const uint8_t *key, |
| 157 | struct StringPair ***prev_next); |
| 158 | |
| 159 | /* If key is already existed in container, its value will be replaced. |
| 160 | * If not existed, creates new entry in container. |
| 161 | */ |
| 162 | void setString(struct PairContainer *container, |
| 163 | const uint8_t *key, |
| 164 | const uint8_t *value, |
| 165 | const int pad_len); |
| 166 | |
| 167 | /* merge all entries in src into dst. If key is duplicate, overwrite it. |
| 168 | */ |
| 169 | void mergeContainer(struct PairContainer *dst, |
| 170 | const struct PairContainer *src); |
| 171 | |
| 172 | /* subtract src from dst. |
| 173 | */ |
| 174 | int subtractContainer(struct PairContainer *dst, |
| 175 | const struct PairContainer *src); |
| 176 | |
| 177 | /* Given a container, encode its all entries into the buffer. |
| 178 | */ |
| 179 | int encodeContainer(const struct PairContainer *container, |
| 180 | const int max_buf_len, |
| 181 | uint8_t *buf, |
| 182 | int *generated); |
| 183 | |
| 184 | /* Given a VPD blob, decode its entries and push into container. |
| 185 | */ |
| 186 | int decodeToContainer(struct PairContainer *container, |
| 187 | const int32_t max_len, |
| 188 | const uint8_t *input_buf, |
| 189 | int32_t *consumed); |
| 190 | |
| 191 | /* Set filter for exporting functions. |
| 192 | * If filter is NULL, resets the filter so that everything can be exported. |
| 193 | */ |
| 194 | int setContainerFilter(struct PairContainer *container, |
| 195 | const uint8_t *filter); |
| 196 | |
| 197 | /* |
| 198 | * Remove a key. |
| 199 | * Returns VPD_OK if deleted successfully. Otherwise, VPD_FAIL. |
| 200 | */ |
| 201 | int deleteKey(struct PairContainer *container, |
| 202 | const uint8_t *key); |
| 203 | |
| 204 | /* |
| 205 | * Returns number of pairs in container. |
| 206 | */ |
| 207 | int lenOfContainer(const struct PairContainer *container); |
| 208 | |
| 209 | /* |
| 210 | * Export the container content with human-readable text. |
| 211 | * |
| 212 | * The buf points to the first byte of buffer and *generated contains the number |
| 213 | * of bytes already existed in buffer. |
| 214 | * |
| 215 | * Afterward, the *generated will be plused on exact bytes this function has |
| 216 | * generated. |
| 217 | */ |
| 218 | int exportContainer(const int export_type, |
| 219 | const struct PairContainer *container, |
| 220 | const int max_buf_len, |
| 221 | uint8_t *buf, |
| 222 | int *generated); |
| 223 | |
| 224 | void destroyContainer(struct PairContainer *container); |
| 225 | |
| 226 | #endif /* __LIB_VPD__ */ |