git.meshlink.io Git - catta/blob - src/probe-sched.c

   1 /***
   2   This file is part of catta.
   3
   4   catta is free software; you can redistribute it and/or modify it
   5   under the terms of the GNU Lesser General Public License as
   6   published by the Free Software Foundation; either version 2.1 of the
   7   License, or (at your option) any later version.
   8
   9   catta is distributed in the hope that it will be useful, but WITHOUT
  10   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  11   or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
  12   Public License for more details.
  13
  14   You should have received a copy of the GNU Lesser General Public
  15   License along with catta; if not, write to the Free Software
  16   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  17   USA.
  18 ***/
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include <config.h>
  22 #endif
  23
  24 #include <stdlib.h>
  25
  26 #include <catta/domain.h>
  27 #include <catta/timeval.h>
  28 #include <catta/malloc.h>
  29
  30 #include "probe-sched.h"
  31 #include <catta/log.h>
  32 #include "rr-util.h"
  33
  34 #define CATTA_PROBE_HISTORY_MSEC 150
  35 #define CATTA_PROBE_DEFER_MSEC 50
  36
  37 typedef struct CattaProbeJob CattaProbeJob;
  38
  39 struct CattaProbeJob {
  40     CattaProbeScheduler *scheduler;
  41     CattaTimeEvent *time_event;
  42
  43     int chosen; /* Use for packet assembling */
  44     int done;
  45     struct timeval delivery;
  46
  47     CattaRecord *record;
  48
  49     CATTA_LLIST_FIELDS(CattaProbeJob, jobs);
  50 };
  51
  52 struct CattaProbeScheduler {
  53     CattaInterface *interface;
  54     CattaTimeEventQueue *time_event_queue;
  55
  56     CATTA_LLIST_HEAD(CattaProbeJob, jobs);
  57     CATTA_LLIST_HEAD(CattaProbeJob, history);
  58 };
  59
  60 static CattaProbeJob* job_new(CattaProbeScheduler *s, CattaRecord *record, int done) {
  61     CattaProbeJob *pj;
  62
  63     assert(s);
  64     assert(record);
  65
  66     if (!(pj = catta_new(CattaProbeJob, 1))) {
  67         catta_log_error(__FILE__": Out of memory");
  68         return NULL; /* OOM */
  69     }
  70
  71     pj->scheduler = s;
  72     pj->record = catta_record_ref(record);
  73     pj->time_event = NULL;
  74     pj->chosen = 0;
  75
  76     if ((pj->done = done))
  77         CATTA_LLIST_PREPEND(CattaProbeJob, jobs, s->history, pj);
  78     else
  79         CATTA_LLIST_PREPEND(CattaProbeJob, jobs, s->jobs, pj);
  80
  81     return pj;
  82 }
  83
  84 static void job_free(CattaProbeScheduler *s, CattaProbeJob *pj) {
  85     assert(pj);
  86
  87     if (pj->time_event)
  88         catta_time_event_free(pj->time_event);
  89
  90     if (pj->done)
  91         CATTA_LLIST_REMOVE(CattaProbeJob, jobs, s->history, pj);
  92     else
  93         CATTA_LLIST_REMOVE(CattaProbeJob, jobs, s->jobs, pj);
  94
  95     catta_record_unref(pj->record);
  96     catta_free(pj);
  97 }
  98
  99 static void elapse_callback(CattaTimeEvent *e, void* data);
 100
 101 static void job_set_elapse_time(CattaProbeScheduler *s, CattaProbeJob *pj, unsigned msec, unsigned jitter) {
 102     struct timeval tv;
 103
 104     assert(s);
 105     assert(pj);
 106
 107     catta_elapse_time(&tv, msec, jitter);
 108
 109     if (pj->time_event)
 110         catta_time_event_update(pj->time_event, &tv);
 111     else
 112         pj->time_event = catta_time_event_new(s->time_event_queue, &tv, elapse_callback, pj);
 113 }
 114
 115 static void job_mark_done(CattaProbeScheduler *s, CattaProbeJob *pj) {
 116     assert(s);
 117     assert(pj);
 118
 119     assert(!pj->done);
 120
 121     CATTA_LLIST_REMOVE(CattaProbeJob, jobs, s->jobs, pj);
 122     CATTA_LLIST_PREPEND(CattaProbeJob, jobs, s->history, pj);
 123
 124     pj->done = 1;
 125
 126     job_set_elapse_time(s, pj, CATTA_PROBE_HISTORY_MSEC, 0);
 127     gettimeofday(&pj->delivery, NULL);
 128 }
 129
 130 CattaProbeScheduler *catta_probe_scheduler_new(CattaInterface *i) {
 131     CattaProbeScheduler *s;
 132
 133     assert(i);
 134
 135     if (!(s = catta_new(CattaProbeScheduler, 1))) {
 136         catta_log_error(__FILE__": Out of memory");
 137         return NULL;
 138     }
 139
 140     s->interface = i;
 141     s->time_event_queue = i->monitor->server->time_event_queue;
 142
 143     CATTA_LLIST_HEAD_INIT(CattaProbeJob, s->jobs);
 144     CATTA_LLIST_HEAD_INIT(CattaProbeJob, s->history);
 145
 146     return s;
 147 }
 148
 149 void catta_probe_scheduler_free(CattaProbeScheduler *s) {
 150     assert(s);
 151
 152     catta_probe_scheduler_clear(s);
 153     catta_free(s);
 154 }
 155
 156 void catta_probe_scheduler_clear(CattaProbeScheduler *s) {
 157     assert(s);
 158
 159     while (s->jobs)
 160         job_free(s, s->jobs);
 161     while (s->history)
 162         job_free(s, s->history);
 163 }
 164
 165 static int packet_add_probe_query(CattaProbeScheduler *s, CattaDnsPacket *p, CattaProbeJob *pj) {
 166     size_t size;
 167     CattaKey *k;
 168     int b;
 169
 170     assert(s);
 171     assert(p);
 172     assert(pj);
 173
 174     assert(!pj->chosen);
 175
 176     /* Estimate the size for this record */
 177     size =
 178         catta_key_get_estimate_size(pj->record->key) +
 179         catta_record_get_estimate_size(pj->record);
 180
 181     /* Too large */
 182     if (size > catta_dns_packet_space(p))
 183         return 0;
 184
 185     /* Create the probe query */
 186     if (!(k = catta_key_new(pj->record->key->name, pj->record->key->clazz, CATTA_DNS_TYPE_ANY)))
 187         return 0; /* OOM */
 188
 189     b = !!catta_dns_packet_append_key(p, k, 0);
 190     assert(b);
 191
 192     /* Mark this job for addition to the packet */
 193     pj->chosen = 1;
 194
 195     /* Scan for more jobs whith matching key pattern */
 196     for (pj = s->jobs; pj; pj = pj->jobs_next) {
 197         if (pj->chosen)
 198             continue;
 199
 200         /* Does the record match the probe? */
 201         if (k->clazz != pj->record->key->clazz || !catta_domain_equal(k->name, pj->record->key->name))
 202             continue;
 203
 204         /* This job wouldn't fit in */
 205         if (catta_record_get_estimate_size(pj->record) > catta_dns_packet_space(p))
 206             break;
 207
 208         /* Mark this job for addition to the packet */
 209         pj->chosen = 1;
 210     }
 211
 212     catta_key_unref(k);
 213
 214     return 1;
 215 }
 216
 217 static void elapse_callback(CATTA_GCC_UNUSED CattaTimeEvent *e, void* data) {
 218     CattaProbeJob *pj = data, *next;
 219     CattaProbeScheduler *s;
 220     CattaDnsPacket *p;
 221     unsigned n;
 222
 223     assert(pj);
 224     s = pj->scheduler;
 225
 226     if (pj->done) {
 227         /* Lets remove it  from the history */
 228         job_free(s, pj);
 229         return;
 230     }
 231
 232     if (!(p = catta_dns_packet_new_query(s->interface->hardware->mtu)))
 233         return; /* OOM */
 234     n = 1;
 235
 236     /* Add the import probe */
 237     if (!packet_add_probe_query(s, p, pj)) {
 238         size_t size;
 239         CattaKey *k;
 240         int b;
 241
 242         catta_dns_packet_free(p);
 243
 244         /* The probe didn't fit in the package, so let's allocate a larger one */
 245
 246         size =
 247             catta_key_get_estimate_size(pj->record->key) +
 248             catta_record_get_estimate_size(pj->record) +
 249             CATTA_DNS_PACKET_HEADER_SIZE;
 250
 251         if (!(p = catta_dns_packet_new_query(size + CATTA_DNS_PACKET_EXTRA_SIZE)))
 252             return; /* OOM */
 253
 254         if (!(k = catta_key_new(pj->record->key->name, pj->record->key->clazz, CATTA_DNS_TYPE_ANY))) {
 255             catta_dns_packet_free(p);
 256             return;  /* OOM */
 257         }
 258
 259         b = catta_dns_packet_append_key(p, k, 0) && catta_dns_packet_append_record(p, pj->record, 0, 0);
 260         catta_key_unref(k);
 261
 262         if (b) {
 263             catta_dns_packet_set_field(p, CATTA_DNS_FIELD_NSCOUNT, 1);
 264             catta_dns_packet_set_field(p, CATTA_DNS_FIELD_QDCOUNT, 1);
 265             catta_interface_send_packet(s->interface, p);
 266         } else
 267             catta_log_warn("Probe record too large, cannot send");
 268
 269         catta_dns_packet_free(p);
 270         job_mark_done(s, pj);
 271
 272         return;
 273     }
 274
 275     /* Try to fill up packet with more probes, if available */
 276     for (pj = s->jobs; pj; pj = pj->jobs_next) {
 277
 278         if (pj->chosen)
 279             continue;
 280
 281         if (!packet_add_probe_query(s, p, pj))
 282             break;
 283
 284         n++;
 285     }
 286
 287     catta_dns_packet_set_field(p, CATTA_DNS_FIELD_QDCOUNT, n);
 288
 289     n = 0;
 290
 291     /* Now add the chosen records to the authorative section */
 292     for (pj = s->jobs; pj; pj = next) {
 293
 294         next = pj->jobs_next;
 295
 296         if (!pj->chosen)
 297             continue;
 298
 299         if (!catta_dns_packet_append_record(p, pj->record, 0, 0)) {
 300 /*             catta_log_warn("Bad probe size estimate!"); */
 301
 302             /* Unmark all following jobs */
 303             for (; pj; pj = pj->jobs_next)
 304                 pj->chosen = 0;
 305
 306             break;
 307         }
 308
 309         job_mark_done(s, pj);
 310
 311         n ++;
 312     }
 313
 314     catta_dns_packet_set_field(p, CATTA_DNS_FIELD_NSCOUNT, n);
 315
 316     /* Send it now */
 317     catta_interface_send_packet(s->interface, p);
 318     catta_dns_packet_free(p);
 319 }
 320
 321 static CattaProbeJob* find_scheduled_job(CattaProbeScheduler *s, CattaRecord *record) {
 322     CattaProbeJob *pj;
 323
 324     assert(s);
 325     assert(record);
 326
 327     for (pj = s->jobs; pj; pj = pj->jobs_next) {
 328         assert(!pj->done);
 329
 330         if (catta_record_equal_no_ttl(pj->record, record))
 331             return pj;
 332     }
 333
 334     return NULL;
 335 }
 336
 337 static CattaProbeJob* find_history_job(CattaProbeScheduler *s, CattaRecord *record) {
 338     CattaProbeJob *pj;
 339
 340     assert(s);
 341     assert(record);
 342
 343     for (pj = s->history; pj; pj = pj->jobs_next) {
 344         assert(pj->done);
 345
 346         if (catta_record_equal_no_ttl(pj->record, record)) {
 347             /* Check whether this entry is outdated */
 348
 349             if (catta_age(&pj->delivery) > CATTA_PROBE_HISTORY_MSEC*1000) {
 350                 /* it is outdated, so let's remove it */
 351                 job_free(s, pj);
 352                 return NULL;
 353             }
 354
 355             return pj;
 356         }
 357     }
 358
 359     return NULL;
 360 }
 361
 362 int catta_probe_scheduler_post(CattaProbeScheduler *s, CattaRecord *record, int immediately) {
 363     CattaProbeJob *pj;
 364     struct timeval tv;
 365
 366     assert(s);
 367     assert(record);
 368     assert(!catta_key_is_pattern(record->key));
 369
 370     if ((pj = find_history_job(s, record)))
 371         return 0;
 372
 373     catta_elapse_time(&tv, immediately ? 0 : CATTA_PROBE_DEFER_MSEC, 0);
 374
 375     if ((pj = find_scheduled_job(s, record))) {
 376
 377         if (catta_timeval_compare(&tv, &pj->delivery) < 0) {
 378             /* If the new entry should be scheduled earlier, update the old entry */
 379             pj->delivery = tv;
 380             catta_time_event_update(pj->time_event, &pj->delivery);
 381         }
 382
 383         return 1;
 384     } else {
 385         /* Create a new job and schedule it */
 386         if (!(pj = job_new(s, record, 0)))
 387             return 0; /* OOM */
 388
 389         pj->delivery = tv;
 390         pj->time_event = catta_time_event_new(s->time_event_queue, &pj->delivery, elapse_callback, pj);
 391
 392
 393 /*     catta_log_debug("Accepted new probe job."); */
 394
 395         return 1;
 396     }
 397 }