Christopher Faulet | d7c9196 | 2015-04-30 11:48:27 +0200 | [diff] [blame] | 1 | /* |
| 2 | * include/types/filteers.h |
| 3 | * This file defines everything related to stream filters. |
| 4 | * |
| 5 | * Copyright (C) 2015 Qualys Inc., Christopher Faulet <cfaulet@qualys.com> |
| 6 | * |
| 7 | * This library is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation, version 2.1 |
| 10 | * exclusively. |
| 11 | * |
| 12 | * This library is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with this library; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | #ifndef _TYPES_FILTERS_H |
| 22 | #define _TYPES_FILTERS_H |
| 23 | |
| 24 | #include <common/config.h> |
| 25 | #include <common/mini-clist.h> |
| 26 | |
| 27 | struct http_msg; |
| 28 | struct proxy; |
| 29 | struct stream; |
| 30 | struct channel; |
| 31 | struct filter; |
| 32 | |
| 33 | /* Descriptor for a "filter" keyword. The ->parse() function returns 0 in case |
| 34 | * of success, or a combination of ERR_* flags if an error is encountered. The |
| 35 | * function pointer can be NULL if not implemented. The function also has an |
| 36 | * access to the current "server" config line. The ->skip value tells the parser |
| 37 | * how many words have to be skipped after the keyword. If the function needs to |
| 38 | * parse more keywords, it needs to update cur_arg. |
| 39 | */ |
| 40 | struct flt_kw { |
| 41 | const char *kw; |
| 42 | int (*parse)(char **args, int *cur_arg, struct proxy *px, |
| 43 | struct filter *filter, char **err); |
| 44 | }; |
| 45 | |
| 46 | /* |
| 47 | * A keyword list. It is a NULL-terminated array of keywords. It embeds a struct |
| 48 | * list in order to be linked to other lists, allowing it to easily be declared |
| 49 | * where it is needed, and linked without duplicating data nor allocating |
| 50 | * memory. It is also possible to indicate a scope for the keywords. |
| 51 | */ |
| 52 | struct flt_kw_list { |
| 53 | const char *scope; |
| 54 | struct list list; |
| 55 | struct flt_kw kw[VAR_ARRAY]; |
| 56 | }; |
| 57 | |
| 58 | /* |
| 59 | * Filter flags set for a specific filter on channel |
| 60 | * |
| 61 | * - FILTER_FL_FORWARD_DATA : When this flag is set, the rest of the data is |
| 62 | * directly forwarded. For chunk-encoded HTTP |
| 63 | * messages, this flag is reseted between each |
| 64 | * chunks. |
| 65 | */ |
| 66 | #define FILTER_FL_FORWARD_DATA 0x00000001 |
| 67 | |
| 68 | |
| 69 | /* |
| 70 | * Callbacks available on a filter: |
| 71 | * |
| 72 | * - init : Initializes the filter for a proxy. Returns a |
| 73 | * negative value if an error occurs. |
| 74 | * - deinit : Cleans up what the init function has done. |
| 75 | * - check : Check the filter config for a proxy. Returns the |
| 76 | * number of errors encountered. |
| 77 | * |
| 78 | * |
| 79 | * - stream_start : Called when a stream is started. This callback will |
| 80 | * only be called for filters defined on a proxy with |
| 81 | * the frontend capability. |
| 82 | * Returns a negative value if an error occurs, any |
| 83 | * other value otherwise. |
| 84 | * - stream_stop : Called when a stream is stopped. This callback will |
| 85 | * only be called for filters defined on a proxy with |
| 86 | * the frontend capability. |
| 87 | * |
| 88 | * |
| 89 | * - channel_start_analyze: Called when a filter starts to analyze a channel. |
| 90 | * Returns a negative value if an error occurs, 0 if |
| 91 | * it needs to wait, any other value otherwise. |
| 92 | * - channel_analyze : Called before each analyzer attached to a channel, |
| 93 | * expects analyzers responsible for data sending. |
| 94 | * Returns a negative value if an error occurs, 0 if |
| 95 | * it needs to wait, any other value otherwise. |
| 96 | * - channel_end_analyze : Called when all other analyzers have finished their |
| 97 | * processing. |
| 98 | * Returns a negative value if an error occurs, 0 if |
| 99 | * it needs to wait, any other value otherwise. |
| 100 | * |
| 101 | * |
| 102 | * - http_headers : Called just before headers sending and parsing of |
| 103 | * the body. At this step, headers are fully parsed |
| 104 | * and the processing on it is finished. |
| 105 | * Returns a negative value if an error occurs, 0 if |
| 106 | * it needs to read more data (or to wait for some |
| 107 | * reason), any other value otherwise. |
| 108 | * - http_start_chunk : Called when we start to process a new chunk |
| 109 | * (for chunk-encoded request/response only). At this |
| 110 | * step, the chunk length is known and non-null. |
| 111 | * Returns a negative value if an error occurs, 0 if |
| 112 | * it needs to read more data (or to wait for some |
| 113 | * reason), any other value otherwise. |
| 114 | * - http_data : Called when unparsed body data are available. |
| 115 | * Returns a negative value if an error occurs, else |
| 116 | * the number of consumed bytes. |
| 117 | * - http_last_chunk : Called when the last chunk (with a zero length) is |
| 118 | * received. |
| 119 | * Returns a negative value if an error occurs, 0 if |
| 120 | * it needs to read more data (or to wait for some |
| 121 | * reason), any other value otherwise. |
| 122 | * - http_end_chunk : Called at the end of a chunk (expect for the last |
| 123 | * one). |
| 124 | * Returns a negative value if an error occurs, 0 if |
| 125 | * it needs to read more data (or to wait for some |
| 126 | * reason), any other value otherwise. |
| 127 | * - http_chunk_trailers : Called when part of trailer headers of a |
| 128 | * chunk-encoded request/response are ready to be |
| 129 | * processed. |
| 130 | * Returns a negative value if an error occurs, any |
| 131 | * other value otherwise. |
| 132 | * - http_end : Called when all the request/response has been |
| 133 | * processed and all body data has been forwarded. |
| 134 | * Returns a negative value if an error occurs, 0 if |
| 135 | * it needs to wait for some reason, any other value |
| 136 | * otherwise. |
| 137 | * - http_reset : Called when the HTTP message is reseted. It happens |
| 138 | * when a 100-continue response is received. |
| 139 | * Returns nothing. |
| 140 | * - http_reply : Called when, at any time, HA proxy decides to stop |
| 141 | * the HTTP message's processing and to send a message |
| 142 | * to the client (mainly, when an error or a redirect |
| 143 | * occur). |
| 144 | * Returns nothing. |
| 145 | * - http_forward_data : Called when some data can be consumed. |
| 146 | * Returns a negative value if an error occurs, else |
| 147 | * the number of forwarded bytes. |
| 148 | * - tcp_data : Called when unparsed data are available. |
| 149 | * Returns a negative value if an error occurs, else |
| 150 | * the number of consumed bytes. |
| 151 | * - tcp_forward_data : Called when some data can be consumed. |
| 152 | * Returns a negative value if an error occurs, else |
| 153 | * or the number of forwarded bytes. |
| 154 | */ |
| 155 | struct flt_ops { |
| 156 | /* |
| 157 | * Callbacks to manage the filter lifecycle |
| 158 | */ |
| 159 | int (*init) (struct proxy *p, struct filter *f); |
| 160 | void (*deinit)(struct proxy *p, struct filter *f); |
| 161 | int (*check) (struct proxy *p, struct filter *f); |
| 162 | |
| 163 | /* |
| 164 | * Stream callbacks |
| 165 | */ |
| 166 | int (*stream_start) (struct stream *s, struct filter *f); |
| 167 | void (*stream_stop) (struct stream *s, struct filter *f); |
| 168 | |
| 169 | /* |
| 170 | * Channel callbacks |
| 171 | */ |
| 172 | int (*channel_start_analyze)(struct stream *s, struct filter *f, struct channel *chn); |
| 173 | int (*channel_analyze) (struct stream *s, struct filter *f, struct channel *chn, unsigned int an_bit); |
| 174 | int (*channel_end_analyze) (struct stream *s, struct filter *f, struct channel *chn); |
| 175 | |
| 176 | /* |
| 177 | * HTTP callbacks |
| 178 | */ |
| 179 | int (*http_headers) (struct stream *s, struct filter *f, struct http_msg *msg); |
| 180 | int (*http_start_chunk) (struct stream *s, struct filter *f, struct http_msg *msg); |
| 181 | int (*http_data) (struct stream *s, struct filter *f, struct http_msg *msg); |
| 182 | int (*http_last_chunk) (struct stream *s, struct filter *f, struct http_msg *msg); |
| 183 | int (*http_end_chunk) (struct stream *s, struct filter *f, struct http_msg *msg); |
| 184 | int (*http_chunk_trailers)(struct stream *s, struct filter *f, struct http_msg *msg); |
| 185 | int (*http_end) (struct stream *s, struct filter *f, struct http_msg *msg); |
| 186 | void (*http_reset) (struct stream *s, struct filter *f, struct http_msg *msg); |
| 187 | |
| 188 | void (*http_reply) (struct stream *s, struct filter *f, short status, |
| 189 | const struct chunk *msg); |
| 190 | int (*http_forward_data) (struct stream *s, struct filter *f, struct http_msg *msg, |
| 191 | unsigned int len); |
| 192 | |
| 193 | /* |
| 194 | * TCP callbacks |
| 195 | */ |
| 196 | int (*tcp_data) (struct stream *s, struct filter *f, struct channel *chn); |
| 197 | int (*tcp_forward_data)(struct stream *s, struct filter *f, struct channel *chn, |
| 198 | unsigned int len); |
| 199 | }; |
| 200 | |
| 201 | /* |
| 202 | * Structure representing the state of a filter. When attached to a proxy, only |
| 203 | * <ops> and <conf> field (and optionnaly <id>) are set. All other fields are |
| 204 | * used when the filter is attached to a stream. |
| 205 | * |
| 206 | * 2D-Array fields are used to store info per channel. The first index stands |
| 207 | * for the request channel, and the second one for the response channel. |
| 208 | * Especially, <next> and <fwd> are offets representing amount of data that the |
| 209 | * filter are, respectively, parsed and forwarded on a channel. Filters can |
| 210 | * access these values using FLT_NXT and FLT_FWD macros. |
| 211 | */ |
| 212 | struct filter { |
| 213 | const char *id; /* The filter id */ |
| 214 | struct flt_ops *ops; /* The filter callbacks */ |
| 215 | void *conf; /* The filter configuration */ |
| 216 | void *ctx; /* The filter context (opaque) */ |
| 217 | int is_backend_filter; /* Flag to specify if the filter is a "backend" filter */ |
| 218 | unsigned int flags[2]; /* 0: request, 1: response */ |
| 219 | unsigned int next[2]; /* Offset, relative to buf->p, to the next byte to parse for a specific channel |
| 220 | * 0: request channel, 1: response channel */ |
| 221 | unsigned int fwd[2]; /* Offset, relative to buf->p, to the next byte to forward for a specific channel |
| 222 | * 0: request channel, 1: response channel */ |
| 223 | struct list list; /* Next filter for the same proxy/stream */ |
| 224 | }; |
| 225 | |
| 226 | #endif /* _TYPES_FILTERS_H */ |
| 227 | |
| 228 | /* |
| 229 | * Local variables: |
| 230 | * c-indent-level: 8 |
| 231 | * c-basic-offset: 8 |
| 232 | * End: |
| 233 | */ |