root/src/noit_filters.c

Revision 37daa37bbc546da8db4d76945b9c4b523e02d77b, 15.1 kB (checked in by Theo Schlossnagle <jesus@omniti.com>, 5 years ago)

online configuration filters, refs #182

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1 /*
2  * Copyright (c) 2007, OmniTI Computer Consulting, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are
7  * met:
8  *
9  *     * Redistributions of source code must retain the above copyright
10  *       notice, this list of conditions and the following disclaimer.
11  *     * Redistributions in binary form must reproduce the above
12  *       copyright notice, this list of conditions and the following
13  *       disclaimer in the documentation and/or other materials provided
14  *       with the distribution.
15  *     * Neither the name OmniTI Computer Consulting, Inc. nor the names
16  *       of its contributors may be used to endorse or promote products
17  *       derived from this software without specific prior written
18  *       permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
26  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
30  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32
33 #include "noit_defines.h"
34
35 #include "utils/noit_hash.h"
36 #include "utils/noit_atomic.h"
37 #include "noit_conf.h"
38 #include "noit_check.h"
39 #include "noit_conf_checks.h"
40 #include "noit_filters.h"
41
42 #include <pcre.h>
43 #include <assert.h>
44 #include <libxml/tree.h>
45
46 static noit_hash_table *filtersets = NULL;
47 static pthread_mutex_t filterset_lock;
48 #define LOCKFS() pthread_mutex_lock(&filterset_lock)
49 #define UNLOCKFS() pthread_mutex_unlock(&filterset_lock)
50
51 typedef enum { NOIT_FILTER_ACCEPT, NOIT_FILTER_DENY } noit_ruletype_t;
52 typedef struct _filterrule {
53   noit_ruletype_t type;
54   pcre *target;
55   pcre_extra *target_e;
56   pcre *module;
57   pcre_extra *module_e;
58   pcre *name;
59   pcre_extra *name_e;
60   pcre *metric;
61   pcre_extra *metric_e;
62   struct _filterrule *next;
63 } filterrule_t;
64
65 typedef struct {
66   noit_atomic32_t ref_cnt;
67   char *name;
68   filterrule_t *rules;
69 } filterset_t;
70
71 #define FRF(r,a) do { \
72   if(r->a) pcre_free(r->a); \
73   if(r->a##_e) pcre_free(r->a##_e); \
74 } while(0)
75
76 static void
77 filterrule_free(void *vp) {
78   filterrule_t *r = vp;
79   FRF(r,target);
80   FRF(r,module);
81   FRF(r,name);
82   FRF(r,metric);
83   free(r);
84 }
85 static void
86 filterset_free(void *vp) {
87   filterset_t *fs = vp;
88   filterrule_t *r;
89   if(noit_atomic_dec32(&fs->ref_cnt) != 0) return;
90   noitL(noit_error, "Freeing filterset [%d]: %s\n", fs->ref_cnt, fs->name);
91   while(fs->rules) {
92     r = fs->rules->next;
93     filterrule_free(fs->rules);
94     fs->rules = r;
95   }
96   if(fs->name) free(fs->name);
97   free(fs);
98 }
99 void
100 noit_filter_compile_add(noit_conf_section_t setinfo) {
101   noit_conf_section_t *rules;
102   int j, fcnt;
103   char filterset_name[256];
104   filterset_t *set;
105   if(!noit_conf_get_stringbuf(setinfo, "@name",
106                               filterset_name, sizeof(filterset_name))) {
107     noitL(noit_error,
108           "filterset with no name, skipping as it cannot be referenced.\n");
109     return;
110   }
111   set = calloc(1, sizeof(*set));
112   set->ref_cnt = 1;
113   set->name = strdup(filterset_name);
114
115   rules = noit_conf_get_sections(setinfo, "rule", &fcnt);
116   /* Here we will work through the list backwards pushing the rules on
117    * the front of the list.  That way we can simply walk them in order
118    * for the application process.
119    */
120   noitL(noit_debug, "Compiling filterset '%s'\n", set->name);
121   for(j=fcnt-1; j>=0; j--) {
122     filterrule_t *rule;
123     char buffer[256];
124     if(!noit_conf_get_stringbuf(rules[j], "@type", buffer, sizeof(buffer)) ||
125        (strcmp(buffer, "accept") && strcmp(buffer, "deny"))) {
126       noitL(noit_error, "rule must have type 'accept' or 'deny'\n");
127       continue;
128     }
129     noitL(noit_debug, "Prepending %s into %s\n", buffer, set->name);
130     rule = calloc(1, sizeof(*rule));
131     rule->type = (!strcmp(buffer, "accept")) ?
132                    NOIT_FILTER_ACCEPT : NOIT_FILTER_DENY;
133
134     /* Compile our rules */
135 #define RULE_COMPILE(rname) do { \
136   if(noit_conf_get_stringbuf(rules[j], "@" #rname, buffer, sizeof(buffer))) { \
137     const char *error; \
138     int erroffset; \
139     rule->rname = pcre_compile(buffer, 0, &error, &erroffset, NULL); \
140     if(!rule->rname) { \
141       noitL(noit_error, "set '%s' rule '%s: %s' compile failed: %s\n", \
142             set->name, #rname, buffer, error ? error : "???"); \
143     } \
144     else { \
145       rule->rname##_e = pcre_study(rule->rname, 0, &error); \
146     } \
147   } \
148 } while(0)
149
150     RULE_COMPILE(target);
151     RULE_COMPILE(module);
152     RULE_COMPILE(name);
153     RULE_COMPILE(metric);
154     rule->next = set->rules;
155     set->rules = rule;
156   }
157   free(rules);
158   LOCKFS();
159   noit_hash_replace(filtersets, set->name, strlen(set->name), (void *)set,
160                     NULL, filterset_free);
161   UNLOCKFS();
162 }
163 void
164 noit_filters_from_conf() {
165   noit_conf_section_t *sets;
166   int i, cnt;
167
168   sets = noit_conf_get_sections(NULL, "/noit/filtersets//filterset", &cnt);
169   for(i=0; i<cnt; i++) {
170     noit_filter_compile_add(sets[i]);
171   }
172   free(sets);
173 }
174
175 void
176 noit_refresh_filtersets(noit_console_closure_t ncct,
177                         noit_conf_t_userdata_t *info) {
178   noit_filters_from_conf();
179   nc_printf(ncct, "Reloaded %d filtersets.\n",
180             filtersets ? filtersets->size : 0);
181 }
182
183 static noit_boolean
184 noit_apply_filterrule(pcre *p, pcre_extra *pe, const char *subj) {
185   int rc, ovector[30];
186   if(!p) return noit_true;
187   rc = pcre_exec(p, pe, subj, strlen(subj), 0, 0, ovector, 30);
188   if(rc >= 0) return noit_true;
189   return noit_false;
190 }
191 noit_boolean
192 noit_apply_filterset(const char *filterset,
193                      noit_check_t *check,
194                      metric_t *metric) {
195   /* We pass in filterset here just in case someone wants to apply
196    * a filterset other than check->filterset.. You never know.
197    */
198   void *vfs;
199   if(!filtersets || !filterset) return noit_true;
200
201   LOCKFS();
202   if(noit_hash_retrieve(filtersets, filterset, strlen(filterset), &vfs)) {
203     filterset_t *fs = (filterset_t *)vfs;
204     filterrule_t *r;
205     noit_atomic_inc32(&fs->ref_cnt);
206     UNLOCKFS();
207 #define MATCHES(rname, value) noit_apply_filterrule(r->rname, r->rname##_e, value)
208     for(r = fs->rules; r; r = r->next) {
209       if(MATCHES(target, check->target) &&
210          MATCHES(module, check->module) &&
211          MATCHES(name, check->name) &&
212          MATCHES(metric, metric->metric_name))
213         return (r->type == NOIT_FILTER_ACCEPT) ? noit_true : noit_false;
214     }
215     filterset_free(fs);
216   }
217   UNLOCKFS();
218   return noit_true;
219 }
220
221 static char *
222 conf_t_filterset_prompt(EditLine *el) {
223   noit_console_closure_t ncct;
224   noit_conf_t_userdata_t *info;
225   static char *tl = "noit(conf)# ";
226   static char *pfmt = "noit(conf:filterset:%.*s%s)# ";
227   int max_space, namelen;
228   el_get(el, EL_USERDATA, (void *)&ncct);
229   if(!ncct) return tl;
230   info = noit_console_userdata_get(ncct, NOIT_CONF_T_USERDATA);
231   if(!info) return tl;
232   max_space = sizeof(info->prompt) - strlen(pfmt) + 6 - 1;
233   namelen = strlen(info->filter_name);
234   if(namelen > max_space)
235     snprintf(info->prompt, sizeof(info->prompt), pfmt,
236              max_space - 3, info->filter_name, "...");
237   else
238     snprintf(info->prompt, sizeof(info->prompt), pfmt,
239              namelen, info->filter_name, "");
240   return info->prompt;
241 }
242
243 static int
244 noit_console_filter_show(noit_console_closure_t ncct,
245                          int argc, char **argv,
246                          noit_console_state_t *state,
247                          void *closure) {
248   noit_conf_t_userdata_t *info;
249   char xpath[1024];
250   xmlNodePtr fsnode;
251   noit_conf_section_t *rules;
252   int i, rulecnt;
253
254   info = noit_console_userdata_get(ncct, NOIT_CONF_T_USERDATA);
255   snprintf(xpath, sizeof(xpath), "/%s",
256            info->path);
257   fsnode = noit_conf_get_section(NULL, xpath);
258   if(!fsnode) {
259     nc_printf(ncct, "internal error\n");
260     return -1;
261   }
262   rules = noit_conf_get_sections(fsnode, "rule", &rulecnt);
263   for(i=0; i<rulecnt; i++) {
264     char val[256];
265     val[0] = '\0';
266     noit_conf_get_stringbuf(rules[i], "@type", val, sizeof(val));
267     nc_printf(ncct, "Rule %d [%s]:\n", i+1, val);
268 #define DUMP_ATTR(a) do { \
269   if(noit_conf_get_stringbuf(rules[i], "@" #a, val, sizeof(val))) { \
270     nc_printf(ncct, "\t%s: /%s/\n", #a, val); \
271   } \
272 } while(0)
273     DUMP_ATTR(target);
274     DUMP_ATTR(module);
275     DUMP_ATTR(name);
276     DUMP_ATTR(metric);
277   }
278   if(rules) free(rules);
279   return 0;
280 }
281 static int
282 noit_console_rule_configure(noit_console_closure_t ncct,
283                             int argc, char **argv,
284                             noit_console_state_t *state,
285                             void *closure) {
286   xmlNodePtr fsnode = NULL;
287   noit_conf_t_userdata_t *info;
288   char xpath[1024];
289
290   info = noit_console_userdata_get(ncct, NOIT_CONF_T_USERDATA);
291   snprintf(xpath, sizeof(xpath), "/%s",
292            info->path);
293   fsnode = noit_conf_get_section(NULL, xpath);
294   if(!fsnode) {
295     nc_printf(ncct, "internal error");
296     return -1;
297   }
298   if(closure) {
299     int rulenum;
300     xmlNodePtr byebye;
301     /* removing a rule */
302     if(argc != 1) {
303       nc_printf(ncct, "requires one argument\n");
304       return -1;
305     }
306     rulenum = atoi(argv[0]);
307     snprintf(xpath, sizeof(xpath), "rule[%d]", rulenum);
308     byebye = noit_conf_get_section(fsnode, xpath);
309     if(!byebye) {
310       nc_printf(ncct, "cannot find rule\n");
311       return -1;
312     }
313     xmlUnlinkNode(byebye);
314     xmlFreeNode(byebye);
315     nc_printf(ncct, "removed\n");
316   }
317   else {
318     xmlNodePtr (*add_func)(xmlNodePtr, xmlNodePtr);
319     xmlNodePtr add_arg, new_rule;
320     int i, needs_type = 1;
321     if(argc < 1 || argc % 2) {
322       nc_printf(ncct, "even number of arguments required\n");
323       return -1;
324     }
325     if(!strcmp(argv[0], "before") || !strcmp(argv[0], "after")) {
326       int rulenum = atoi(argv[1]);
327       snprintf(xpath, sizeof(xpath), "rule[%d]", rulenum);
328       add_arg = noit_conf_get_section(fsnode, xpath);
329       if(!add_arg) {
330         nc_printf(ncct, "%s rule not found\n", xpath);
331         return -1;
332       }
333       if(*argv[0] == 'b') add_func = xmlAddPrevSibling;
334       else add_func = xmlAddNextSibling;
335       argc -= 2;
336       argv += 2;
337     }
338     else {
339       add_func = xmlAddChild;
340       add_arg = fsnode;
341     }
342     for(i=0;i<argc;i+=2) {
343       if(!strcmp(argv[i], "type")) needs_type = 0;
344       else if(strcmp(argv[i], "target") && strcmp(argv[i], "module") &&
345               strcmp(argv[i], "name") && strcmp(argv[i], "metric")) {
346         nc_printf(ncct, "unknown attribute '%s'\n", argv[i]);
347         return -1;
348       }
349     }
350     if(needs_type) {
351       nc_printf(ncct, "type <allow|deny> is required\n");
352       return -1;
353     }
354     new_rule = xmlNewNode(NULL, (xmlChar *)"rule");
355     for(i=0;i<argc;i+=2)
356       xmlSetProp(new_rule, (xmlChar *)argv[i], (xmlChar *)argv[i+1]);
357     add_func(add_arg, new_rule);
358     noit_filter_compile_add((noit_conf_section_t *)fsnode);
359   }
360   return 0;
361 }
362 static int
363 noit_console_filter_configure(noit_console_closure_t ncct,
364                               int argc, char **argv,
365                               noit_console_state_t *state,
366                               void *closure) {
367   xmlNodePtr parent, fsnode = NULL;
368   int rv = -1;
369   noit_conf_t_userdata_t *info;
370   char xpath[1024];
371
372   info = noit_console_userdata_get(ncct, NOIT_CONF_T_USERDATA);
373   if(!info ||
374      (strncmp(info->path, "/filtersets/", strlen("/filtersets/")) &&
375       strcmp(info->path, "/filtersets"))) {
376     nc_printf(ncct, "filterset only allows inside /filtersets (not %s)\n",
377               info->path);
378     goto cleanup;
379   }
380   if(argc != 1) {
381     nc_printf(ncct, "filterset requires one argument\n");
382     goto cleanup;
383   }
384   snprintf(xpath, sizeof(xpath), "/%s", info->path);
385   parent = noit_conf_get_section(NULL, xpath);
386   if(!parent) {
387     nc_printf(ncct, "internal error, can't final current working path\n");
388     goto cleanup;
389   }
390   snprintf(xpath, sizeof(xpath), "filterset[@name=\"%s\"]", argv[0]);
391   fsnode = noit_conf_get_section(parent, xpath);
392   if(closure) {
393     int removed;
394     LOCKFS();
395     removed = noit_hash_delete(filtersets, argv[0], strlen(argv[0]),
396                                NULL, filterset_free);
397     UNLOCKFS();
398     nc_printf(ncct, "%sremoved filterset '%s'\n",
399               removed ? "" : "failed to ", argv[0]);
400     if(removed) {
401       xmlUnlinkNode(fsnode);
402       xmlFreeNode(fsnode);
403     }
404     rv = !removed;
405     goto cleanup;
406   }
407   if(!fsnode) {
408     void *vfs;
409     nc_printf(ncct, "Cannot find filterset '%s'\n", argv[0]);
410     LOCKFS();
411     if(noit_hash_retrieve(filtersets, argv[0], strlen(argv[0]), &vfs)) {
412       UNLOCKFS();
413       nc_printf(ncct, "filter of the same name already exists\n");
414       goto cleanup;
415     }
416     UNLOCKFS();
417     /* Fine the parent path */
418     fsnode = xmlNewNode(NULL, (xmlChar *)"filterset");
419     xmlSetProp(fsnode, (xmlChar *)"name", (xmlChar *)argv[0]);
420     xmlAddChild(parent, fsnode);
421     nc_printf(ncct, "created new filterset\n");
422   }
423
424   if(info) {
425     if(info->path) free(info->path);
426     info->path = strdup((char *)xmlGetNodePath(fsnode) + strlen("/noit"));
427     strlcpy(info->filter_name, argv[0], sizeof(info->filter_name));
428     if(state) {
429       noit_console_state_push_state(ncct, state);
430       noit_console_state_init(ncct);
431     }
432   }
433  cleanup:
434   return rv;
435 }
436
437 static void
438 register_console_filter_commands() {
439   noit_console_state_t *tl, *filterset_state, *nostate;
440   cmd_info_t *confcmd, *conf_t_cmd, *no_cmd;
441
442   tl = noit_console_state_initial();
443   confcmd = noit_console_state_get_cmd(tl, "configure");
444   assert(confcmd && confcmd->dstate);
445
446   conf_t_cmd = noit_console_state_get_cmd(confcmd->dstate, "terminal");
447   assert(conf_t_cmd && conf_t_cmd->dstate);
448
449   nostate = noit_console_state_alloc();
450   noit_console_state_add_cmd(nostate,
451     NCSCMD("rule", noit_console_rule_configure, NULL, NULL, (void *)1));
452
453   filterset_state = noit_console_state_alloc();
454   noit_console_state_add_cmd(filterset_state,
455     NCSCMD("exit", noit_console_config_cd, NULL, NULL, ".."));
456   noit_console_state_add_cmd(filterset_state,
457     NCSCMD("status", noit_console_filter_show, NULL, NULL, NULL));
458   noit_console_state_add_cmd(filterset_state,
459     NCSCMD("rule", noit_console_rule_configure, NULL, NULL, NULL));
460   noit_console_state_add_cmd(filterset_state,
461     NCSCMD("no", noit_console_state_delegate, noit_console_opt_delegate,
462            nostate, NULL));
463
464   filterset_state->console_prompt_function = conf_t_filterset_prompt;
465
466   noit_console_state_add_cmd(conf_t_cmd->dstate,
467     NCSCMD("filterset", noit_console_filter_configure,
468            NULL, filterset_state, NULL));
469
470   no_cmd = noit_console_state_get_cmd(conf_t_cmd->dstate, "no");
471   assert(no_cmd && no_cmd->dstate);
472   noit_console_state_add_cmd(no_cmd->dstate,
473     NCSCMD("filterset", noit_console_filter_configure, NULL, NULL, (void *)1));
474 }
475
476 void
477 noit_filters_init() {
478   pthread_mutex_init(&filterset_lock, NULL);
479   filtersets = calloc(1, sizeof(noit_hash_table));
480   register_console_filter_commands();
481   noit_filters_from_conf();
482 }
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