1 /*
2 * include/proto/filters.h
3 * This file defines function prototypes for stream filters management.
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 _PROTO_FILTERS_H
22 #define _PROTO_FILTERS_H
23
24 #include <types/channel.h>
25 #include <types/filters.h>
26 #include <types/proto_http.h>
27 #include <types/proxy.h>
28 #include <types/stream.h>
29
30 #include <proto/channel.h>
31
32 #define FLT_ID(flt) (flt)->config->id
33 #define FLT_CONF(flt) (flt)->config->conf
34 #define FLT_OPS(flt) (flt)->config->ops
35
36 /* Useful macros to access per-channel values. It can be safely used inside
37 * filters. */
38 #define CHN_IDX(chn) (((chn)->flags & CF_ISRESP) == CF_ISRESP)
39 #define FLT_NXT(flt, chn) ((flt)->next[CHN_IDX(chn)])
40 #define FLT_FWD(flt, chn) ((flt)->fwd[CHN_IDX(chn)])
41 #define flt_req_nxt(flt) ((flt)->next[0])
42 #define flt_rsp_nxt(flt) ((flt)->next[1])
43 #define flt_req_fwd(flt) ((flt)->fwd[0])
44 #define flt_rsp_fwd(flt) ((flt)->fwd[1])
45
46 #define HAS_FILTERS(strm) ((strm)->strm_flt.flags & STRM_FLT_FL_HAS_FILTERS)
47
48 #define HAS_REQ_DATA_FILTERS(strm) ((strm)->strm_flt.nb_req_data_filters != 0)
49 #define HAS_RSP_DATA_FILTERS(strm) ((strm)->strm_flt.nb_rsp_data_filters != 0)
50 #define HAS_DATA_FILTERS(strm, chn) (((chn)->flags & CF_ISRESP) ? HAS_RSP_DATA_FILTERS(strm) : HAS_REQ_DATA_FILTERS(strm))
51
52 #define IS_REQ_DATA_FILTER(flt) ((flt)->flags & FLT_FL_IS_REQ_DATA_FILTER)
53 #define IS_RSP_DATA_FILTER(flt) ((flt)->flags & FLT_FL_IS_RSP_DATA_FILTER)
54 #define IS_DATA_FILTER(flt, chn) (((chn)->flags & CF_ISRESP) ? IS_RSP_DATA_FILTER(flt) : IS_REQ_DATA_FILTER(flt))
55
56 #define FLT_STRM_CB(strm, call) \
57 do { \
58 if (HAS_FILTERS(strm)) { call; } \
59 } while (0)
60
61 #define FLT_STRM_DATA_CB_IMPL_1(strm, chn, call, default_ret) \
62 (HAS_DATA_FILTERS(strm, chn) ? call : default_ret)
63 #define FLT_STRM_DATA_CB_IMPL_2(strm, chn, call, default_ret, on_error) \
64 ({ \
65 int _ret; \
66 if (HAS_DATA_FILTERS(strm, chn)) { \
67 _ret = call; \
68 if (_ret < 0) { on_error; } \
69 } \
70 else \
71 _ret = default_ret; \
72 _ret; \
73 })
74 #define FLT_STRM_DATA_CB_IMPL_3(strm, chn, call, default_ret, on_error, on_wait) \
75 ({ \
76 int _ret; \
77 if (HAS_DATA_FILTERS(strm, chn)) { \
78 _ret = call; \
79 if (_ret < 0) { on_error; } \
80 if (!_ret) { on_wait; } \
81 } \
82 else \
83 _ret = default_ret; \
84 _ret; \
85 })
86
87 #define FLT_STRM_DATA_CB_IMPL_X(strm, chn, call, A, B, C, DATA_CB_IMPL, ...) \
88 DATA_CB_IMPL
89
90 #define FLT_STRM_DATA_CB(strm, chn, call, ...) \
91 FLT_STRM_DATA_CB_IMPL_X(strm, chn, call, ##__VA_ARGS__, \
92 FLT_STRM_DATA_CB_IMPL_3(strm, chn, call, ##__VA_ARGS__), \
93 FLT_STRM_DATA_CB_IMPL_2(strm, chn, call, ##__VA_ARGS__), \
94 FLT_STRM_DATA_CB_IMPL_1(strm, chn, call, ##__VA_ARGS__))
95
96 extern struct pool_head *pool2_filter;
97
98 int flt_init(struct proxy *p);
99 void flt_deinit(struct proxy *p);
100 int flt_check(struct proxy *p);
101
102 int flt_stream_start(struct stream *s);
103 void flt_stream_stop(struct stream *s);
104 int flt_set_stream_backend(struct stream *s, struct proxy *be);
105 int flt_stream_init(struct stream *s);
106 void flt_stream_release(struct stream *s, int only_backend);
107 void flt_stream_check_timeouts(struct stream *s);
108
109 int flt_http_data(struct stream *s, struct http_msg *msg);
110 int flt_http_chunk_trailers(struct stream *s, struct http_msg *msg);
111 int flt_http_end(struct stream *s, struct http_msg *msg);
112 int flt_http_forward_data(struct stream *s, struct http_msg *msg, unsigned int len);
113
114 void flt_http_reset(struct stream *s, struct http_msg *msg);
115 void flt_http_reply(struct stream *s, short status, const struct chunk *msg);
116
117 int flt_start_analyze(struct stream *s, struct channel *chn, unsigned int an_bit);
118 int flt_pre_analyze(struct stream *s, struct channel *chn, unsigned int an_bit);
119 int flt_post_analyze(struct stream *s, struct channel *chn, unsigned int an_bit);
120 int flt_analyze_http_headers(struct stream *s, struct channel *chn, unsigned int an_bit);
121 int flt_end_analyze(struct stream *s, struct channel *chn, unsigned int an_bit);
122
123 int flt_xfer_data(struct stream *s, struct channel *chn, unsigned int an_bit);
124
125 void flt_register_keywords(struct flt_kw_list *kwl);
126 struct flt_kw *flt_find_kw(const char *kw);
127 void flt_dump_kws(char **out);
128 void list_filters(FILE *out);
129
130 /* Helper function that returns the "global" state of filters attached to a
131 * stream. */
132 static inline struct strm_flt *
strm_flt(struct stream * s)133 strm_flt(struct stream *s)
134 {
135 return &s->strm_flt;
136 }
137
138 /* Registers a filter to a channel. If a filter was already registered, this
139 * function do nothing. Once registered, the filter becomes a "data" filter for
140 * this channel. */
141 static inline void
register_data_filter(struct stream * s,struct channel * chn,struct filter * filter)142 register_data_filter(struct stream *s, struct channel *chn, struct filter *filter)
143 {
144 if (!IS_DATA_FILTER(filter, chn)) {
145 if (chn->flags & CF_ISRESP) {
146 filter->flags |= FLT_FL_IS_RSP_DATA_FILTER;
147 strm_flt(s)->nb_rsp_data_filters++;
148 }
149 else {
150 filter->flags |= FLT_FL_IS_REQ_DATA_FILTER;
151 strm_flt(s)->nb_req_data_filters++;
152 }
153 }
154 }
155
156 /* Unregisters a "data" filter from a channel. */
157 static inline void
unregister_data_filter(struct stream * s,struct channel * chn,struct filter * filter)158 unregister_data_filter(struct stream *s, struct channel *chn, struct filter *filter)
159 {
160 if (IS_DATA_FILTER(filter, chn)) {
161 if (chn->flags & CF_ISRESP) {
162 filter->flags &= ~FLT_FL_IS_RSP_DATA_FILTER;
163 strm_flt(s)->nb_rsp_data_filters--;
164
165 }
166 else {
167 filter->flags &= ~FLT_FL_IS_REQ_DATA_FILTER;
168 strm_flt(s)->nb_req_data_filters--;
169 }
170 }
171 }
172
173 /* This function must be called when a filter alter incoming data. It updates
174 * next offset value of all filter's predecessors. Do not call this function
175 * when a filter change the size of incomding data leads to an undefined
176 * behavior.
177 *
178 * This is the filter's responsiblitiy to update data itself. For now, it is
179 * unclear to know how to handle data updates, so we do the minimum here. For
180 * example, if you filter an HTTP message, we must update msg->next and
181 * msg->chunk_len values.
182 */
183 static inline void
flt_change_next_size(struct filter * filter,struct channel * chn,int len)184 flt_change_next_size(struct filter *filter, struct channel *chn, int len)
185 {
186 struct stream *s = chn_strm(chn);
187 struct filter *f;
188
189 list_for_each_entry(f, &strm_flt(s)->filters, list) {
190 if (f == filter)
191 break;
192 if (IS_DATA_FILTER(filter, chn))
193 FLT_NXT(f, chn) += len;
194 }
195 }
196
197 /* This function must be called when a filter alter forwarded data. It updates
198 * offset values (next and forward) of all filters. Do not call this function
199 * when a filter change the size of forwarded data leads to an undefined
200 * behavior.
201 *
202 * This is the filter's responsiblitiy to update data itself. For now, it is
203 * unclear to know how to handle data updates, so we do the minimum here. For
204 * example, if you filter an HTTP message, we must update msg->next and
205 * msg->chunk_len values.
206 */
207 static inline void
flt_change_forward_size(struct filter * filter,struct channel * chn,int len)208 flt_change_forward_size(struct filter *filter, struct channel *chn, int len)
209 {
210 struct stream *s = chn_strm(chn);
211 struct filter *f;
212 int before = 1;
213
214 list_for_each_entry(f, &strm_flt(s)->filters, list) {
215 if (f == filter)
216 before = 0;
217 if (IS_DATA_FILTER(filter, chn)) {
218 if (before)
219 FLT_FWD(f, chn) += len;
220 FLT_NXT(f, chn) += len;
221 }
222 }
223 }
224
225
226 #endif /* _PROTO_FILTERS_H */
227