Daniel Erat | 748945e | 2015-08-11 09:22:30 -0600 | [diff] [blame] | 1 | /* |
| 2 | This file is part of libmicrospdy |
| 3 | Copyright Copyright (C) 2012 Andrey Uzunov |
| 4 | |
| 5 | This program is free software: you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation, either version 3 of the License, or |
| 8 | (at your option) any later version. |
| 9 | |
| 10 | This program is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 17 | */ |
| 18 | |
| 19 | /** |
| 20 | * @file session.h |
| 21 | * @brief TCP connection/SPDY session handling |
| 22 | * @author Andrey Uzunov |
| 23 | */ |
| 24 | |
| 25 | #ifndef SESSION_H |
| 26 | #define SESSION_H |
| 27 | |
| 28 | #include "platform.h" |
| 29 | #include "structures.h" |
| 30 | |
| 31 | /** |
| 32 | * Called by the daemon when the socket for the session has available |
| 33 | * data to be read. Reads data from the TLS socket and puts it to the |
| 34 | * session's read buffer. The latte |
| 35 | * |
| 36 | * @param session SPDY_Session for which data will be read. |
| 37 | * @return SPDY_YES if something was read or session's status was |
| 38 | * changed. It is possible that error occurred but was handled |
| 39 | * and the status was therefore changed. |
| 40 | * SPDY_NO if nothing happened, e.g. the subsystem wants read/ |
| 41 | * write to be called again. |
| 42 | */ |
| 43 | int |
| 44 | SPDYF_session_read (struct SPDY_Session *session); |
| 45 | |
| 46 | |
| 47 | /** |
| 48 | * Called by the daemon when the socket for the session is ready for some |
| 49 | * data to be written to it. For one or more objects on the response |
| 50 | * queue tries to fill in the write buffer, based on the frame on the |
| 51 | * queue, and to write data to the TLS socket. |
| 52 | * |
| 53 | * @param session SPDY_Session for which data will be written. |
| 54 | * @param only_one_frame when true, the function will write at most one |
| 55 | * SPDY frame to the underlying IO subsystem; |
| 56 | * when false, the function will write up to |
| 57 | * session->max_num_frames SPDY frames |
| 58 | * @return SPDY_YES if the session's internal writing state has changed: |
| 59 | * something was written and/or session's status was |
| 60 | * changed and/or response callback was called but did not provide |
| 61 | * data. It is possible that error occurred but was handled |
| 62 | * and the status was therefore changed. |
| 63 | * SPDY_NO if nothing happened. However, it is possible that some |
| 64 | * frames were discarded within the call, e.g. frames belonging |
| 65 | * to a closed stream. |
| 66 | */ |
| 67 | int |
| 68 | SPDYF_session_write (struct SPDY_Session *session, |
| 69 | bool only_one_frame); |
| 70 | |
| 71 | |
| 72 | /** |
| 73 | * Called by the daemon on SPDY_run to handle the data in the read and write |
| 74 | * buffer of a session. Based on the state and the content of the read |
| 75 | * buffer new frames are received and interpreted, appropriate user |
| 76 | * callbacks are called and maybe something is put on the response queue |
| 77 | * ready to be handled by session_write. |
| 78 | * |
| 79 | * @param session SPDY_Session which will be handled. |
| 80 | * @return SPDY_YES if something from the read buffers was processed, |
| 81 | * session's status was changed and/or the session was closed. |
| 82 | * SPDY_NO if nothing happened, e.g. the session is in a state, |
| 83 | * not allowing processing read buffers. |
| 84 | */ |
| 85 | int |
| 86 | SPDYF_session_idle (struct SPDY_Session *session); |
| 87 | |
| 88 | |
| 89 | /** |
| 90 | * This function shutdowns the socket, moves the session structure to |
| 91 | * daemon's queue for sessions to be cleaned up. |
| 92 | * |
| 93 | * @param session SPDY_Session which will be handled. |
| 94 | */ |
| 95 | void |
| 96 | SPDYF_session_close (struct SPDY_Session *session); |
| 97 | |
| 98 | |
| 99 | /** |
| 100 | * Called to accept new TCP connection and create SPDY session. |
| 101 | * |
| 102 | * @param daemon SPDY_Daemon whose listening socket is used. |
| 103 | * @return SPDY_NO on any kind of error while accepting new TCP connection |
| 104 | * and initializing new SPDY_Session. |
| 105 | * SPDY_YES otherwise. |
| 106 | */ |
| 107 | int |
| 108 | SPDYF_session_accept(struct SPDY_Daemon *daemon); |
| 109 | |
| 110 | |
| 111 | /** |
| 112 | * Puts SPDYF_Response_Queue object on the queue to be sent to the |
| 113 | * client later. |
| 114 | * |
| 115 | * @param response_to_queue linked list of objects containing SPDY |
| 116 | * frame and data to be added to the queue |
| 117 | * @param session SPDY session for which the response is sent |
| 118 | * @param consider_priority if SPDY_NO, the list will be added to the |
| 119 | * end of the queue. |
| 120 | * If SPDY_YES, the response will be added after |
| 121 | * the last previously added response with priority of the |
| 122 | * request grater or equal to that of the current one. |
| 123 | * If -1, the object will be put at the head of the queue. |
| 124 | */ |
| 125 | void |
| 126 | SPDYF_queue_response (struct SPDYF_Response_Queue *response_to_queue, |
| 127 | struct SPDY_Session *session, |
| 128 | int consider_priority); |
| 129 | |
| 130 | |
| 131 | /** |
| 132 | * Cleans up the TSL context for the session, closes the TCP connection, |
| 133 | * cleans up any data pointed by members of the session structure |
| 134 | * (buffers, queue of responses, etc.) and frees the memory allocated by |
| 135 | * the session itself. |
| 136 | */ |
| 137 | void |
| 138 | SPDYF_session_destroy(struct SPDY_Session *session); |
| 139 | |
| 140 | |
| 141 | /** |
| 142 | * Prepares GOAWAY frame to tell the client to stop creating new streams. |
| 143 | * The session should be closed soon after this call. |
| 144 | * |
| 145 | * @param session SPDY session |
| 146 | * @param status code for the GOAWAY frame |
| 147 | * @param in_front whether or not to put the frame in front of everything |
| 148 | * on the response queue |
| 149 | * @return SPDY_NO on error (not enough memory) or |
| 150 | * SPDY_YES on success |
| 151 | */ |
| 152 | int |
| 153 | SPDYF_prepare_goaway (struct SPDY_Session *session, |
| 154 | enum SPDY_GOAWAY_STATUS status, |
| 155 | bool in_front); |
| 156 | |
| 157 | |
| 158 | /** |
| 159 | * Prepares RST_STREAM frame to terminate a stream. This frame may or |
| 160 | * not indicate an error. The frame will be put at the head of the queue. |
| 161 | * This means that frames for this stream which are still in the queue |
| 162 | * will be discarded soon. |
| 163 | * |
| 164 | * @param session SPDY session |
| 165 | * @param stream stream to terminate |
| 166 | * @param status code for the RST_STREAM frame |
| 167 | * @return SPDY_NO on memory error or |
| 168 | * SPDY_YES on success |
| 169 | */ |
| 170 | int |
| 171 | SPDYF_prepare_rst_stream (struct SPDY_Session *session, |
| 172 | struct SPDYF_Stream * stream, |
| 173 | enum SPDY_RST_STREAM_STATUS status); |
| 174 | |
| 175 | |
| 176 | /** |
| 177 | * Prepares WINDOW_UPDATE frame to tell the other party that more |
| 178 | * data can be sent on the stream. The frame will be put at the head of |
| 179 | * the queue. |
| 180 | * |
| 181 | * @param session SPDY session |
| 182 | * @param stream stream to which the changed window will apply |
| 183 | * @param delta_window_size how much the window grows |
| 184 | * @return SPDY_NO on memory error or |
| 185 | * SPDY_YES on success |
| 186 | */ |
| 187 | int |
| 188 | SPDYF_prepare_window_update (struct SPDY_Session *session, |
| 189 | struct SPDYF_Stream * stream, |
| 190 | int32_t delta_window_size); |
| 191 | |
| 192 | |
| 193 | /** |
| 194 | * Handler called by session_write to fill the write buffer according to |
| 195 | * the data frame waiting in the response queue. |
| 196 | * When response data is given by user callback, the lib does not know |
| 197 | * how many frames are needed. In such case this call produces |
| 198 | * another ResponseQueue object and puts it on the queue while the the |
| 199 | * user callback says that there will be more data. |
| 200 | * |
| 201 | * @return SPDY_NO on error (not enough memory or the user calback for |
| 202 | * providing response data did something wrong). If |
| 203 | * the error is unrecoverable the handler changes session's |
| 204 | * status. |
| 205 | * SPDY_YES on success |
| 206 | */ |
| 207 | int |
| 208 | SPDYF_handler_write_data (struct SPDY_Session *session); |
| 209 | |
| 210 | |
| 211 | /** |
| 212 | * Handler called by session_write to fill the write buffer based on the |
| 213 | * control frame (SYN_REPLY) waiting in the response queue. |
| 214 | * |
| 215 | * @param session SPDY session |
| 216 | * @return SPDY_NO on error (zlib state is broken; the session MUST be |
| 217 | * closed). If |
| 218 | * the error is unrecoverable the handler changes session's |
| 219 | * status. |
| 220 | * SPDY_YES on success |
| 221 | */ |
| 222 | int |
| 223 | SPDYF_handler_write_syn_reply (struct SPDY_Session *session); |
| 224 | |
| 225 | |
| 226 | /** |
| 227 | * Handler called by session_write to fill the write buffer based on the |
| 228 | * control frame (GOAWAY) waiting in the response queue. |
| 229 | * |
| 230 | * @param session SPDY session |
| 231 | * @return SPDY_NO on error (not enough memory; by specification the |
| 232 | * session must be closed |
| 233 | * soon, thus there is no need to handle the error) or |
| 234 | * SPDY_YES on success |
| 235 | */ |
| 236 | int |
| 237 | SPDYF_handler_write_goaway (struct SPDY_Session *session); |
| 238 | |
| 239 | |
| 240 | /** |
| 241 | * Handler called by session_write to fill the write buffer based on the |
| 242 | * control frame (RST_STREAM) waiting in the response queue. |
| 243 | * |
| 244 | * @param session SPDY session |
| 245 | * @return SPDY_NO on error (not enough memory). If |
| 246 | * the error is unrecoverable the handler changes session's |
| 247 | * status. |
| 248 | * SPDY_YES on success |
| 249 | */ |
| 250 | int |
| 251 | SPDYF_handler_write_rst_stream (struct SPDY_Session *session); |
| 252 | |
| 253 | |
| 254 | /** |
| 255 | * Handler called by session_write to fill the write buffer based on the |
| 256 | * control frame (WINDOW_UPDATE) waiting in the response queue. |
| 257 | * |
| 258 | * @param session SPDY session |
| 259 | * @return SPDY_NO on error (not enough memory). If |
| 260 | * the error is unrecoverable the handler changes session's |
| 261 | * status. |
| 262 | * SPDY_YES on success |
| 263 | */ |
| 264 | int |
| 265 | SPDYF_handler_write_window_update (struct SPDY_Session *session); |
| 266 | |
| 267 | |
| 268 | /** |
| 269 | * Carefully ignore the full size of frames which are not yet supported |
| 270 | * by the lib. |
| 271 | * TODO Ignoring frames containing compressed bodies means that the |
| 272 | * compress state will be corrupted on next received frame. According to |
| 273 | * the draft the lib SHOULD try to decompress data also in corrupted |
| 274 | * frames just to keep right compression state. |
| 275 | * |
| 276 | * @param session SPDY_Session whose read buffer is used. |
| 277 | */ |
| 278 | void |
| 279 | SPDYF_handler_ignore_frame (struct SPDY_Session *session); |
| 280 | |
| 281 | #endif |