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 flt_conf; 32 struct filter; 33 34 /* Descriptor for a "filter" keyword. The ->parse() function returns 0 in case 35 * of success, or a combination of ERR_* flags if an error is encountered. The 36 * function pointer can be NULL if not implemented. 37 */ 38 struct flt_kw { 39 const char *kw; 40 int (*parse)(char **args, int *cur_arg, struct proxy *px, 41 struct flt_conf *fconf, char **err, void *private); 42 void *private; 43 }; 44 45 /* 46 * A keyword list. It is a NULL-terminated array of keywords. It embeds a struct 47 * list in order to be linked to other lists, allowing it to easily be declared 48 * where it is needed, and linked without duplicating data nor allocating 49 * memory. It is also possible to indicate a scope for the keywords. 50 */ 51 struct flt_kw_list { 52 const char *scope; 53 struct list list; 54 struct flt_kw kw[VAR_ARRAY]; 55 }; 56 57 /* 58 * Callbacks available on a filter: 59 * 60 * - init : Initializes the filter for a proxy. Returns a 61 * negative value if an error occurs. 62 * - deinit : Cleans up what the init function has done. 63 * - check : Check the filter config for a proxy. Returns the 64 * number of errors encountered. 65 * - init_per_thread : Initializes the filter for a proxy for a specific 66 * thread. Returns a negative value if an error 67 * occurs. 68 * - deinit_per_thread : Cleans up what the init_per_thread funcion has 69 * done. 70 * 71 * 72 * - attach : Called after a filter instance creation, when it is 73 * attached to a stream. This happens when the stream 74 * is started for filters defined on the stream's 75 * frontend and when the backend is set for filters 76 * declared on the stream's backend. 77 * Returns a negative value if an error occurs, 0 if 78 * the filter must be ignored for the stream, any other 79 * value otherwise. 80 * - stream_start : Called when a stream is started. This callback will 81 * only be called for filters defined on the stream's 82 * frontend. 83 * Returns a negative value if an error occurs, any 84 * other value otherwise. 85 * - stream_set_backend : Called when a backend is set for a stream. This 86 * callbacks will be called for all filters attached 87 * to a stream (frontend and backend). 88 * Returns a negative value if an error occurs, any 89 * other value otherwise. 90 * - stream_stop : Called when a stream is stopped. This callback will 91 * only be called for filters defined on the stream's 92 * frontend. 93 * - detach : Called when a filter instance is detached from a 94 * stream, before its destruction. This happens when 95 * the stream is stopped for filters defined on the 96 * stream's frontend and when the analyze ends for 97 * filters defined on the stream's backend. 98 * - check_timeouts : Called when a a stream is woken up because of an 99 * expired timer. 100 * 101 * 102 * - channel_start_analyze: Called when a filter starts to analyze a channel. 103 * Returns a negative value if an error occurs, 0 if 104 * it needs to wait, any other value otherwise. 105 * - channel_pre_analyze : Called before each analyzer attached to a channel, 106 * expects analyzers responsible for data sending. 107 * Returns a negative value if an error occurs, 0 if 108 * it needs to wait, any other value otherwise. 109 * - channel_post_analyze: Called after each analyzer attached to a channel, 110 * expects analyzers responsible for data sending. 111 * Returns a negative value if an error occurs, 112 * any other value otherwise. 113 * - channel_end_analyze : Called when all other analyzers have finished their 114 * processing. 115 * Returns a negative value if an error occurs, 0 if 116 * it needs to wait, any other value otherwise. 117 * 118 * 119 * - http_headers : Called before the body parsing, after all HTTP 120 * headers was parsed and analyzed. 121 * Returns a negative value if an error occurs, 0 if 122 * it needs to wait, any other value otherwise. 123 * - http_payload : Called when some data can be consumed. 124 * Returns a negative value if an error occurs, else 125 * the number of forwarded bytes. 126 * - http_data : Called when unparsed body data are available. 127 * Returns a negative value if an error occurs, else 128 * the number of consumed bytes. [DEPRECATED] 129 * - http_chunk_trailers : Called when part of trailer headers of a 130 * chunk-encoded request/response are ready to be 131 * processed. 132 * Returns a negative value if an error occurs, any 133 * other value otherwise. [DEPRECATED] 134 * - http_end : Called when all the request/response has been 135 * processed and all body data has been forwarded. 136 * Returns a negative value if an error occurs, 0 if 137 * it needs to wait for some reason, any other value 138 * otherwise. 139 * - http_reset : Called when the HTTP message is reseted. It happens 140 * either when a 100-continue response is received. 141 * that can be detected if s->txn->status is 10X, or 142 * if we're attempting a L7 retry. 143 * Returns nothing. 144 * - http_reply : Called when, at any time, HA proxy decides to stop 145 * the HTTP message's processing and to send a message 146 * to the client (mainly, when an error or a redirect 147 * occur). 148 * Returns nothing. 149 * - http_forward_data : Called when some data can be consumed. 150 * Returns a negative value if an error occurs, else 151 * the number of forwarded bytes. [DEPRECATED] 152 * - tcp_data : Called when unparsed data are available. 153 * Returns a negative value if an error occurs, else 154 * the number of consumed bytes. 155 * - tcp_forward_data : Called when some data can be consumed. 156 * Returns a negative value if an error occurs, else 157 * or the number of forwarded bytes. 158 */ 159 struct flt_ops { 160 /* 161 * Callbacks to manage the filter lifecycle 162 */ 163 int (*init) (struct proxy *p, struct flt_conf *fconf); 164 void (*deinit) (struct proxy *p, struct flt_conf *fconf); 165 int (*check) (struct proxy *p, struct flt_conf *fconf); 166 int (*init_per_thread) (struct proxy *p, struct flt_conf *fconf); 167 void (*deinit_per_thread)(struct proxy *p, struct flt_conf *fconf); 168 /* 169 * Stream callbacks 170 */ 171 int (*attach) (struct stream *s, struct filter *f); 172 int (*stream_start) (struct stream *s, struct filter *f); 173 int (*stream_set_backend)(struct stream *s, struct filter *f, struct proxy *be); 174 void (*stream_stop) (struct stream *s, struct filter *f); 175 void (*detach) (struct stream *s, struct filter *f); 176 void (*check_timeouts) (struct stream *s, struct filter *f); 177 /* 178 * Channel callbacks 179 */ 180 int (*channel_start_analyze)(struct stream *s, struct filter *f, struct channel *chn); 181 int (*channel_pre_analyze) (struct stream *s, struct filter *f, struct channel *chn, unsigned int an_bit); 182 int (*channel_post_analyze) (struct stream *s, struct filter *f, struct channel *chn, unsigned int an_bit); 183 int (*channel_end_analyze) (struct stream *s, struct filter *f, struct channel *chn); 184 185 /* 186 * HTTP callbacks 187 */ 188 int (*http_headers) (struct stream *s, struct filter *f, struct http_msg *msg); 189 int (*http_payload) (struct stream *s, struct filter *f, struct http_msg *msg, 190 unsigned int offset, unsigned int len); 191 int (*http_end) (struct stream *s, struct filter *f, struct http_msg *msg); 192 int (*http_data) (struct stream *s, struct filter *f, struct http_msg *msg); // DEPRECATED 193 int (*http_chunk_trailers)(struct stream *s, struct filter *f, struct http_msg *msg); // DEPRECATED 194 int (*http_forward_data) (struct stream *s, struct filter *f, struct http_msg *msg, // DEPRECATED 195 unsigned int len); 196 197 void (*http_reset) (struct stream *s, struct filter *f, struct http_msg *msg); 198 void (*http_reply) (struct stream *s, struct filter *f, short status, 199 const struct buffer *msg); 200 201 /* 202 * TCP callbacks 203 */ 204 int (*tcp_data) (struct stream *s, struct filter *f, struct channel *chn); 205 int (*tcp_forward_data)(struct stream *s, struct filter *f, struct channel *chn, 206 unsigned int len); 207 }; 208 209 /* Flags set on a filter config */ 210 #define FLT_CFG_FL_HTX 0x00000001 /* The filter can filter HTX streams */ 211 212 /* Flags set on a filter instance */ 213 #define FLT_FL_IS_BACKEND_FILTER 0x0001 /* The filter is a backend filter */ 214 #define FLT_FL_IS_REQ_DATA_FILTER 0x0002 /* The filter will parse data on the request channel */ 215 #define FLT_FL_IS_RSP_DATA_FILTER 0x0004 /* The filter will parse data on the response channel */ 216 217 /* Flags set on the stream, common to all filters attached to its stream */ 218 #define STRM_FLT_FL_HAS_FILTERS 0x0001 /* The stream has at least one filter */ 219 #define STRM_FLT_FL_HOLD_HTTP_HDRS 0x0002 /* At least one filter on the stream want to hold the message headers */ 220 221 /* 222 * Structure representing the filter configuration, attached to a proxy and 223 * accessible from a filter when instantiated in a stream 224 */ 225 struct flt_conf { 226 const char *id; /* The filter id */ 227 struct flt_ops *ops; /* The filter callbacks */ 228 void *conf; /* The filter configuration */ 229 struct list list; /* Next filter for the same proxy */ 230 unsigned int flags; /* FLT_CFG_FL_* */ 231 }; 232 233 /* 234 * Structure reprensenting a filter instance attached to a stream 235 * 236 * 2D-Array fields are used to store info per channel. The first index stands 237 * for the request channel, and the second one for the response channel. 238 * Especially, <next> and <fwd> are offets representing amount of data that the 239 * filter are, respectively, parsed and forwarded on a channel. Filters can 240 * access these values using FLT_NXT and FLT_FWD macros. 241 */ 242 struct filter { 243 struct flt_conf *config; /* the filter's configuration */ 244 void *ctx; /* The filter context (opaque) */ 245 unsigned short flags; /* FLT_FL_* */ 246 unsigned int next[2]; /* Offset, relative to buf->p, to the next byte to parse for a specific channel 247 * 0: request channel, 1: response channel */ 248 unsigned int fwd[2]; /* Offset, relative to buf->p, to the next byte to forward for a specific channel 249 * 0: request channel, 1: response channel */ 250 unsigned long long offset[2]; 251 unsigned int pre_analyzers; /* bit field indicating analyzers to pre-process */ 252 unsigned int post_analyzers; /* bit field indicating analyzers to post-process */ 253 struct list list; /* Next filter for the same proxy/stream */ 254 }; 255 256 /* 257 * Structure reprensenting the "global" state of filters attached to a stream. 258 */ 259 struct strm_flt { 260 struct list filters; /* List of filters attached to a stream */ 261 struct filter *current[2]; /* From which filter resume processing, for a specific channel. 262 * This is used for resumable callbacks only, 263 * If NULL, we start from the first filter. 264 * 0: request channel, 1: response channel */ 265 unsigned short flags; /* STRM_FL_* */ 266 unsigned char nb_req_data_filters; /* Number of data filters registered on the request channel */ 267 unsigned char nb_rsp_data_filters; /* Number of data filters registered on the response channel */ 268 unsigned long long offset[2]; 269 }; 270 271 #endif /* _TYPES_FILTERS_H */ 272 273 /* 274 * Local variables: 275 * c-indent-level: 8 276 * c-basic-offset: 8 277 * End: 278 */ 279