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| 1 | +#ifndef INCLUDE_LLHTTP_API_H_ |
| 2 | +#define INCLUDE_LLHTTP_API_H_ |
| 3 | +#ifdef __cplusplus |
| 4 | +extern "C" { |
| 5 | +#endif |
| 6 | +#include <stddef.h> |
| 7 | + |
| 8 | +#if defined(__wasm__) |
| 9 | +#define LLHTTP_EXPORT __attribute__((visibility("default"))) |
| 10 | +#elif defined(_WIN32) |
| 11 | +#define LLHTTP_EXPORT __declspec(dllexport) |
| 12 | +#else |
| 13 | +#define LLHTTP_EXPORT |
| 14 | +#endif |
| 15 | + |
| 16 | +typedef llhttp__internal_t llhttp_t; |
| 17 | +typedef struct llhttp_settings_s llhttp_settings_t; |
| 18 | + |
| 19 | +typedef int (*llhttp_data_cb)(llhttp_t*, const char *at, size_t length); |
| 20 | +typedef int (*llhttp_cb)(llhttp_t*); |
| 21 | + |
| 22 | +struct llhttp_settings_s { |
| 23 | + /* Possible return values 0, -1, `HPE_PAUSED` */ |
| 24 | + llhttp_cb on_message_begin; |
| 25 | + |
| 26 | + /* Possible return values 0, -1, HPE_USER */ |
| 27 | + llhttp_data_cb on_url; |
| 28 | + llhttp_data_cb on_status; |
| 29 | + llhttp_data_cb on_method; |
| 30 | + llhttp_data_cb on_version; |
| 31 | + llhttp_data_cb on_header_field; |
| 32 | + llhttp_data_cb on_header_value; |
| 33 | + llhttp_data_cb on_chunk_extension_name; |
| 34 | + llhttp_data_cb on_chunk_extension_value; |
| 35 | + |
| 36 | + /* Possible return values: |
| 37 | + * 0 - Proceed normally |
| 38 | + * 1 - Assume that request/response has no body, and proceed to parsing the |
| 39 | + * next message |
| 40 | + * 2 - Assume absence of body (as above) and make `llhttp_execute()` return |
| 41 | + * `HPE_PAUSED_UPGRADE` |
| 42 | + * -1 - Error |
| 43 | + * `HPE_PAUSED` |
| 44 | + */ |
| 45 | + llhttp_cb on_headers_complete; |
| 46 | + |
| 47 | + /* Possible return values 0, -1, HPE_USER */ |
| 48 | + llhttp_data_cb on_body; |
| 49 | + |
| 50 | + /* Possible return values 0, -1, `HPE_PAUSED` */ |
| 51 | + llhttp_cb on_message_complete; |
| 52 | + llhttp_cb on_url_complete; |
| 53 | + llhttp_cb on_status_complete; |
| 54 | + llhttp_cb on_method_complete; |
| 55 | + llhttp_cb on_version_complete; |
| 56 | + llhttp_cb on_header_field_complete; |
| 57 | + llhttp_cb on_header_value_complete; |
| 58 | + llhttp_cb on_chunk_extension_name_complete; |
| 59 | + llhttp_cb on_chunk_extension_value_complete; |
| 60 | + |
| 61 | + /* When on_chunk_header is called, the current chunk length is stored |
| 62 | + * in parser->content_length. |
| 63 | + * Possible return values 0, -1, `HPE_PAUSED` |
| 64 | + */ |
| 65 | + llhttp_cb on_chunk_header; |
| 66 | + llhttp_cb on_chunk_complete; |
| 67 | + llhttp_cb on_reset; |
| 68 | +}; |
| 69 | + |
| 70 | +/* Initialize the parser with specific type and user settings. |
| 71 | + * |
| 72 | + * NOTE: lifetime of `settings` has to be at least the same as the lifetime of |
| 73 | + * the `parser` here. In practice, `settings` has to be either a static |
| 74 | + * variable or be allocated with `malloc`, `new`, etc. |
| 75 | + */ |
| 76 | +LLHTTP_EXPORT |
| 77 | +void llhttp_init(llhttp_t* parser, llhttp_type_t type, |
| 78 | + const llhttp_settings_t* settings); |
| 79 | + |
| 80 | +LLHTTP_EXPORT |
| 81 | +llhttp_t* llhttp_alloc(llhttp_type_t type); |
| 82 | + |
| 83 | +LLHTTP_EXPORT |
| 84 | +void llhttp_free(llhttp_t* parser); |
| 85 | + |
| 86 | +LLHTTP_EXPORT |
| 87 | +uint8_t llhttp_get_type(llhttp_t* parser); |
| 88 | + |
| 89 | +LLHTTP_EXPORT |
| 90 | +uint8_t llhttp_get_http_major(llhttp_t* parser); |
| 91 | + |
| 92 | +LLHTTP_EXPORT |
| 93 | +uint8_t llhttp_get_http_minor(llhttp_t* parser); |
| 94 | + |
| 95 | +LLHTTP_EXPORT |
| 96 | +uint8_t llhttp_get_method(llhttp_t* parser); |
| 97 | + |
| 98 | +LLHTTP_EXPORT |
| 99 | +int llhttp_get_status_code(llhttp_t* parser); |
| 100 | + |
| 101 | +LLHTTP_EXPORT |
| 102 | +uint8_t llhttp_get_upgrade(llhttp_t* parser); |
| 103 | + |
| 104 | +/* Reset an already initialized parser back to the start state, preserving the |
| 105 | + * existing parser type, callback settings, user data, and lenient flags. |
| 106 | + */ |
| 107 | +LLHTTP_EXPORT |
| 108 | +void llhttp_reset(llhttp_t* parser); |
| 109 | + |
| 110 | +/* Initialize the settings object */ |
| 111 | +LLHTTP_EXPORT |
| 112 | +void llhttp_settings_init(llhttp_settings_t* settings); |
| 113 | + |
| 114 | +/* Parse full or partial request/response, invoking user callbacks along the |
| 115 | + * way. |
| 116 | + * |
| 117 | + * If any of `llhttp_data_cb` returns errno not equal to `HPE_OK` - the parsing |
| 118 | + * interrupts, and such errno is returned from `llhttp_execute()`. If |
| 119 | + * `HPE_PAUSED` was used as a errno, the execution can be resumed with |
| 120 | + * `llhttp_resume()` call. |
| 121 | + * |
| 122 | + * In a special case of CONNECT/Upgrade request/response `HPE_PAUSED_UPGRADE` |
| 123 | + * is returned after fully parsing the request/response. If the user wishes to |
| 124 | + * continue parsing, they need to invoke `llhttp_resume_after_upgrade()`. |
| 125 | + * |
| 126 | + * NOTE: if this function ever returns a non-pause type error, it will continue |
| 127 | + * to return the same error upon each successive call up until `llhttp_init()` |
| 128 | + * is called. |
| 129 | + */ |
| 130 | +LLHTTP_EXPORT |
| 131 | +llhttp_errno_t llhttp_execute(llhttp_t* parser, const char* data, size_t len); |
| 132 | + |
| 133 | +/* This method should be called when the other side has no further bytes to |
| 134 | + * send (e.g. shutdown of readable side of the TCP connection.) |
| 135 | + * |
| 136 | + * Requests without `Content-Length` and other messages might require treating |
| 137 | + * all incoming bytes as the part of the body, up to the last byte of the |
| 138 | + * connection. This method will invoke `on_message_complete()` callback if the |
| 139 | + * request was terminated safely. Otherwise a error code would be returned. |
| 140 | + */ |
| 141 | +LLHTTP_EXPORT |
| 142 | +llhttp_errno_t llhttp_finish(llhttp_t* parser); |
| 143 | + |
| 144 | +/* Returns `1` if the incoming message is parsed until the last byte, and has |
| 145 | + * to be completed by calling `llhttp_finish()` on EOF |
| 146 | + */ |
| 147 | +LLHTTP_EXPORT |
| 148 | +int llhttp_message_needs_eof(const llhttp_t* parser); |
| 149 | + |
| 150 | +/* Returns `1` if there might be any other messages following the last that was |
| 151 | + * successfully parsed. |
| 152 | + */ |
| 153 | +LLHTTP_EXPORT |
| 154 | +int llhttp_should_keep_alive(const llhttp_t* parser); |
| 155 | + |
| 156 | +/* Make further calls of `llhttp_execute()` return `HPE_PAUSED` and set |
| 157 | + * appropriate error reason. |
| 158 | + * |
| 159 | + * Important: do not call this from user callbacks! User callbacks must return |
| 160 | + * `HPE_PAUSED` if pausing is required. |
| 161 | + */ |
| 162 | +LLHTTP_EXPORT |
| 163 | +void llhttp_pause(llhttp_t* parser); |
| 164 | + |
| 165 | +/* Might be called to resume the execution after the pause in user's callback. |
| 166 | + * See `llhttp_execute()` above for details. |
| 167 | + * |
| 168 | + * Call this only if `llhttp_execute()` returns `HPE_PAUSED`. |
| 169 | + */ |
| 170 | +LLHTTP_EXPORT |
| 171 | +void llhttp_resume(llhttp_t* parser); |
| 172 | + |
| 173 | +/* Might be called to resume the execution after the pause in user's callback. |
| 174 | + * See `llhttp_execute()` above for details. |
| 175 | + * |
| 176 | + * Call this only if `llhttp_execute()` returns `HPE_PAUSED_UPGRADE` |
| 177 | + */ |
| 178 | +LLHTTP_EXPORT |
| 179 | +void llhttp_resume_after_upgrade(llhttp_t* parser); |
| 180 | + |
| 181 | +/* Returns the latest return error */ |
| 182 | +LLHTTP_EXPORT |
| 183 | +llhttp_errno_t llhttp_get_errno(const llhttp_t* parser); |
| 184 | + |
| 185 | +/* Returns the verbal explanation of the latest returned error. |
| 186 | + * |
| 187 | + * Note: User callback should set error reason when returning the error. See |
| 188 | + * `llhttp_set_error_reason()` for details. |
| 189 | + */ |
| 190 | +LLHTTP_EXPORT |
| 191 | +const char* llhttp_get_error_reason(const llhttp_t* parser); |
| 192 | + |
| 193 | +/* Assign verbal description to the returned error. Must be called in user |
| 194 | + * callbacks right before returning the errno. |
| 195 | + * |
| 196 | + * Note: `HPE_USER` error code might be useful in user callbacks. |
| 197 | + */ |
| 198 | +LLHTTP_EXPORT |
| 199 | +void llhttp_set_error_reason(llhttp_t* parser, const char* reason); |
| 200 | + |
| 201 | +/* Returns the pointer to the last parsed byte before the returned error. The |
| 202 | + * pointer is relative to the `data` argument of `llhttp_execute()`. |
| 203 | + * |
| 204 | + * Note: this method might be useful for counting the number of parsed bytes. |
| 205 | + */ |
| 206 | +LLHTTP_EXPORT |
| 207 | +const char* llhttp_get_error_pos(const llhttp_t* parser); |
| 208 | + |
| 209 | +/* Returns textual name of error code */ |
| 210 | +LLHTTP_EXPORT |
| 211 | +const char* llhttp_errno_name(llhttp_errno_t err); |
| 212 | + |
| 213 | +/* Returns textual name of HTTP method */ |
| 214 | +LLHTTP_EXPORT |
| 215 | +const char* llhttp_method_name(llhttp_method_t method); |
| 216 | + |
| 217 | +/* Returns textual name of HTTP status */ |
| 218 | +LLHTTP_EXPORT |
| 219 | +const char* llhttp_status_name(llhttp_status_t status); |
| 220 | + |
| 221 | +/* Enables/disables lenient header value parsing (disabled by default). |
| 222 | + * |
| 223 | + * Lenient parsing disables header value token checks, extending llhttp's |
| 224 | + * protocol support to highly non-compliant clients/server. No |
| 225 | + * `HPE_INVALID_HEADER_TOKEN` will be raised for incorrect header values when |
| 226 | + * lenient parsing is "on". |
| 227 | + * |
| 228 | + * **Enabling this flag can pose a security issue since you will be exposed to |
| 229 | + * request smuggling attacks. USE WITH CAUTION!** |
| 230 | + */ |
| 231 | +LLHTTP_EXPORT |
| 232 | +void llhttp_set_lenient_headers(llhttp_t* parser, int enabled); |
| 233 | + |
| 234 | + |
| 235 | +/* Enables/disables lenient handling of conflicting `Transfer-Encoding` and |
| 236 | + * `Content-Length` headers (disabled by default). |
| 237 | + * |
| 238 | + * Normally `llhttp` would error when `Transfer-Encoding` is present in |
| 239 | + * conjunction with `Content-Length`. This error is important to prevent HTTP |
| 240 | + * request smuggling, but may be less desirable for small number of cases |
| 241 | + * involving legacy servers. |
| 242 | + * |
| 243 | + * **Enabling this flag can pose a security issue since you will be exposed to |
| 244 | + * request smuggling attacks. USE WITH CAUTION!** |
| 245 | + */ |
| 246 | +LLHTTP_EXPORT |
| 247 | +void llhttp_set_lenient_chunked_length(llhttp_t* parser, int enabled); |
| 248 | + |
| 249 | + |
| 250 | +/* Enables/disables lenient handling of `Connection: close` and HTTP/1.0 |
| 251 | + * requests responses. |
| 252 | + * |
| 253 | + * Normally `llhttp` would error on (in strict mode) or discard (in loose mode) |
| 254 | + * the HTTP request/response after the request/response with `Connection: close` |
| 255 | + * and `Content-Length`. This is important to prevent cache poisoning attacks, |
| 256 | + * but might interact badly with outdated and insecure clients. With this flag |
| 257 | + * the extra request/response will be parsed normally. |
| 258 | + * |
| 259 | + * **Enabling this flag can pose a security issue since you will be exposed to |
| 260 | + * poisoning attacks. USE WITH CAUTION!** |
| 261 | + */ |
| 262 | +LLHTTP_EXPORT |
| 263 | +void llhttp_set_lenient_keep_alive(llhttp_t* parser, int enabled); |
| 264 | + |
| 265 | +/* Enables/disables lenient handling of `Transfer-Encoding` header. |
| 266 | + * |
| 267 | + * Normally `llhttp` would error when a `Transfer-Encoding` has `chunked` value |
| 268 | + * and another value after it (either in a single header or in multiple |
| 269 | + * headers whose value are internally joined using `, `). |
| 270 | + * This is mandated by the spec to reliably determine request body size and thus |
| 271 | + * avoid request smuggling. |
| 272 | + * With this flag the extra value will be parsed normally. |
| 273 | + * |
| 274 | + * **Enabling this flag can pose a security issue since you will be exposed to |
| 275 | + * request smuggling attacks. USE WITH CAUTION!** |
| 276 | + */ |
| 277 | +LLHTTP_EXPORT |
| 278 | +void llhttp_set_lenient_transfer_encoding(llhttp_t* parser, int enabled); |
| 279 | + |
| 280 | +/* Enables/disables lenient handling of HTTP version. |
| 281 | + * |
| 282 | + * Normally `llhttp` would error when the HTTP version in the request or status line |
| 283 | + * is not `0.9`, `1.0`, `1.1` or `2.0`. |
| 284 | + * With this flag the invalid value will be parsed normally. |
| 285 | + * |
| 286 | + * **Enabling this flag can pose a security issue since you will allow unsupported |
| 287 | + * HTTP versions. USE WITH CAUTION!** |
| 288 | + */ |
| 289 | +LLHTTP_EXPORT |
| 290 | +void llhttp_set_lenient_version(llhttp_t* parser, int enabled); |
| 291 | + |
| 292 | +/* Enables/disables lenient handling of additional data received after a message ends |
| 293 | + * and keep-alive is disabled. |
| 294 | + * |
| 295 | + * Normally `llhttp` would error when additional unexpected data is received if the message |
| 296 | + * contains the `Connection` header with `close` value. |
| 297 | + * With this flag the extra data will discarded without throwing an error. |
| 298 | + * |
| 299 | + * **Enabling this flag can pose a security issue since you will be exposed to |
| 300 | + * poisoning attacks. USE WITH CAUTION!** |
| 301 | + */ |
| 302 | +LLHTTP_EXPORT |
| 303 | +void llhttp_set_lenient_data_after_close(llhttp_t* parser, int enabled); |
| 304 | + |
| 305 | +/* Enables/disables lenient handling of incomplete CRLF sequences. |
| 306 | + * |
| 307 | + * Normally `llhttp` would error when a CR is not followed by LF when terminating the |
| 308 | + * request line, the status line, the headers or a chunk header. |
| 309 | + * With this flag only a CR is required to terminate such sections. |
| 310 | + * |
| 311 | + * **Enabling this flag can pose a security issue since you will be exposed to |
| 312 | + * request smuggling attacks. USE WITH CAUTION!** |
| 313 | + */ |
| 314 | +LLHTTP_EXPORT |
| 315 | +void llhttp_set_lenient_optional_lf_after_cr(llhttp_t* parser, int enabled); |
| 316 | + |
| 317 | +/* |
| 318 | + * Enables/disables lenient handling of line separators. |
| 319 | + * |
| 320 | + * Normally `llhttp` would error when a LF is not preceded by CR when terminating the |
| 321 | + * request line, the status line, the headers, a chunk header or a chunk data. |
| 322 | + * With this flag only a LF is required to terminate such sections. |
| 323 | + * |
| 324 | + * **Enabling this flag can pose a security issue since you will be exposed to |
| 325 | + * request smuggling attacks. USE WITH CAUTION!** |
| 326 | + */ |
| 327 | +LLHTTP_EXPORT |
| 328 | +void llhttp_set_lenient_optional_cr_before_lf(llhttp_t* parser, int enabled); |
| 329 | + |
| 330 | +/* Enables/disables lenient handling of chunks not separated via CRLF. |
| 331 | + * |
| 332 | + * Normally `llhttp` would error when after a chunk data a CRLF is missing before |
| 333 | + * starting a new chunk. |
| 334 | + * With this flag the new chunk can start immediately after the previous one. |
| 335 | + * |
| 336 | + * **Enabling this flag can pose a security issue since you will be exposed to |
| 337 | + * request smuggling attacks. USE WITH CAUTION!** |
| 338 | + */ |
| 339 | +LLHTTP_EXPORT |
| 340 | +void llhttp_set_lenient_optional_crlf_after_chunk(llhttp_t* parser, int enabled); |
| 341 | + |
| 342 | +/* Enables/disables lenient handling of spaces after chunk size. |
| 343 | + * |
| 344 | + * Normally `llhttp` would error when after a chunk size is followed by one or more |
| 345 | + * spaces are present instead of a CRLF or `;`. |
| 346 | + * With this flag this check is disabled. |
| 347 | + * |
| 348 | + * **Enabling this flag can pose a security issue since you will be exposed to |
| 349 | + * request smuggling attacks. USE WITH CAUTION!** |
| 350 | + */ |
| 351 | +LLHTTP_EXPORT |
| 352 | +void llhttp_set_lenient_spaces_after_chunk_size(llhttp_t* parser, int enabled); |
| 353 | + |
| 354 | +#ifdef __cplusplus |
| 355 | +} /* extern "C" */ |
| 356 | +#endif |
| 357 | +#endif /* INCLUDE_LLHTTP_API_H_ */ |
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