grpsess.c

   1 /*
   2  * Fernando ALVES 2013
   3  * Grouped session for load balancing and fail-over
   4  * GPL licenced
   5  */
   6
   7 #include <errno.h>
   8 #include <ctype.h>
   9 #include <string.h>
  10 #include <sys/socket.h>
  11 #include <linux/rtnetlink.h>
  12
  13 #include "l2tpns.h"
  14 #include "util.h"
  15 #include "cluster.h"
  16
  17 #ifdef BGP
  18 #include "bgp.h"
  19 #endif
  20
  21 union grp_iphash {
  22         groupidt grp;
  23         union grp_iphash *idx;
  24 } grp_ip_hash[256];                     // Mapping from IP address to group structures.
  25
  26 groupidt gnextgrpid = 0;
  27
  28 // Find gruop by IP, < 1 for not found
  29 //
  30 // Confusingly enough, this 'ip' must be
  31 // in _network_ order. This being the common
  32 // case when looking it up from IP packet headers.
  33 static groupidt grp_lookup_ipmap(in_addr_t ip)
  34 {
  35         uint8_t *a = (uint8_t *) &ip;
  36         union grp_iphash *h = grp_ip_hash;
  37
  38         if (!(h = h[*a++].idx)) return 0;
  39         if (!(h = h[*a++].idx)) return 0;
  40         if (!(h = h[*a++].idx)) return 0;
  41
  42         return h[*a].grp;
  43 }
  44
  45 typedef struct
  46 {
  47         sessionidt sid_loaddist[0x10000];
  48 }
  49 local_group;
  50
  51 local_group *grp_local = NULL;          // Array of local_group structures.
  52
  53 //
  54 // Take an IP address in HOST byte order and
  55 // add it to the grouid by IP cache.
  56 //
  57 // (It's actually cached in network order)
  58 //
  59 static void grp_cache_ipmap(in_addr_t ip, groupidt g)
  60 {
  61         in_addr_t nip = htonl(ip);      // MUST be in network order. I.e. MSB must in be ((char *) (&ip))[0]
  62         uint8_t *a = (uint8_t *) &nip;
  63         union grp_iphash *h = grp_ip_hash;
  64         int i;
  65
  66         for (i = 0; i < 3; i++)
  67         {
  68                 if (!(h[a[i]].idx || (h[a[i]].idx = calloc(256, sizeof(union grp_iphash)))))
  69                         return;
  70
  71                 h = h[a[i]].idx;
  72         }
  73
  74         h[a[3]].grp = g;
  75
  76         if (g > 0)
  77                 LOG(4, 0, 0, "Caching Group:%d ip address %s\n", g, fmtaddr(nip, 0));
  78         else if (g == 0)
  79                 LOG(4, 0, 0, "Un-caching Group ip address %s\n", fmtaddr(nip, 0));
  80 }
  81
  82 groupidt grp_groupbyip(in_addr_t ip)
  83 {
  84         groupidt g = grp_lookup_ipmap(ip);
  85
  86         if (g > 0 && g < MAXGROUPE)
  87                 return g;
  88
  89         return 0;
  90 }
  91
  92 // Add a route
  93 //
  94 // This adds it to the routing table, advertises it
  95 // via BGP if enabled, and stuffs it into the
  96 // 'groupbyip' cache.
  97 //
  98 // 'ip' must be in _host_ order.
  99 //
 100 static void grp_routeset(groupidt g, in_addr_t ip, int prefixlen, int add)
 101 {
 102         struct {
 103                 struct nlmsghdr nh;
 104                 struct rtmsg rt;
 105                 char buf[32];
 106         } req;
 107         int i;
 108         in_addr_t n_ip;
 109
 110         if (!prefixlen) prefixlen = 32;
 111
 112         ip &= 0xffffffff << (32 - prefixlen);;  // Force the ip to be the first one in the route.
 113
 114         memset(&req, 0, sizeof(req));
 115
 116         if (add)
 117         {
 118                 req.nh.nlmsg_type = RTM_NEWROUTE;
 119                 req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_REPLACE;
 120         }
 121         else
 122         {
 123                 req.nh.nlmsg_type = RTM_DELROUTE;
 124                 req.nh.nlmsg_flags = NLM_F_REQUEST;
 125         }
 126
 127         req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.rt));
 128
 129         req.rt.rtm_family = AF_INET;
 130         req.rt.rtm_dst_len = prefixlen;
 131         req.rt.rtm_table = RT_TABLE_MAIN;
 132         req.rt.rtm_protocol = 42;
 133         req.rt.rtm_scope = RT_SCOPE_LINK;
 134         req.rt.rtm_type = RTN_UNICAST;
 135
 136         netlink_addattr(&req.nh, RTA_OIF, &tunidx, sizeof(int));
 137         n_ip = htonl(ip);
 138         netlink_addattr(&req.nh, RTA_DST, &n_ip, sizeof(n_ip));
 139
 140         LOG(3, 0, 0, "Route (Group) %s %s/%d\n", add ? "add" : "del", fmtaddr(htonl(ip), 0), prefixlen);
 141
 142         if (netlink_send(&req.nh) < 0)
 143                 LOG(0, 0, 0, "grp_routeset() error in sending netlink message: %s\n", strerror(errno));
 144
 145 #ifdef BGP
 146         if (add)
 147                 bgp_add_route(htonl(ip), prefixlen);
 148         else
 149                 bgp_del_route(htonl(ip), prefixlen);
 150 #endif /* BGP */
 151
 152         // Add/Remove the IPs to the 'groupbyip' cache.
 153         // Note that we add the zero address in the case of
 154         // a network route. Roll on CIDR.
 155
 156         // Note that 'g == 0' implies this is the address pool.
 157         // We still cache it here, because it will pre-fill
 158         // the malloc'ed tree.
 159         if (g)
 160         {
 161                 if (!add)       // Are we deleting a route?
 162                         g = 0;  // Caching the session as '0' is the same as uncaching.
 163
 164                 for (i = ip; i < ip+(1<<(32-prefixlen)) ; ++i)
 165                 {
 166                         grp_cache_ipmap(i, g);
 167                         if (!g) cache_ipmap(i, 0);
 168                 }
 169         }
 170 }
 171
 172 // Set all route of a group
 173 void grp_setgrouproute(groupidt g, int add)
 174 {
 175         int i;
 176         for (i = 0; i < grpsession[g].nbroutesgrp; i++)
 177         {
 178                 if (grpsession[g].route[i].ip != 0)
 179                 {
 180                         grp_routeset(g, grpsession[g].route[i].ip, grpsession[g].route[i].prefixlen, add);
 181                 }
 182         }
 183 }
 184
 185 // return group id by session
 186 groupidt grp_groupbysession(sessionidt s)
 187 {
 188         groupidt g = 0;
 189         int i;
 190         for (g = gnextgrpid; g != 0; g = grpsession[g].prev)
 191         {
 192                 for (i = 0; i < grpsession[g].nbsession; i++)
 193                 {
 194                         if (grpsession[g].sesslist[i].sid == s)
 195                         {       // session found in group
 196                                 return g;
 197                         }
 198                 }
 199         }
 200
 201         return 0;
 202 }
 203
 204 // Remove a session to a group
 205 // return 1 if OK
 206 void grp_removesession(groupidt g, sessionidt s)
 207 {
 208         int i;
 209
 210         if (grpsession[g].nbsession <= 0)
 211                 return;
 212
 213         for (i = 0; i < grpsession[g].nbsession; i++)
 214         {
 215                 if (grpsession[g].sesslist[i].sid == s)
 216                 {       // session found on group
 217                         --grpsession[g].nbsession;
 218                         if (grpsession[g].nbsession == 0)
 219                         {
 220                                 // Group is empty, remove it
 221
 222                                 // Del all routes
 223                                 grp_setgrouproute(g, 0);
 224
 225                                 if (gnextgrpid == g)
 226                                 {
 227                                         gnextgrpid = grpsession[g].prev;
 228                                 }
 229                                 else
 230                                 {
 231                                         groupidt g2;
 232                                         for (g2 = gnextgrpid; g2 != 0; g2 = grpsession[g2].prev)
 233                                         {
 234                                                 if (grpsession[g2].prev == g)
 235                                                 {
 236                                                         grpsession[g2].prev = grpsession[g].prev;
 237                                                         break;
 238                                                 }
 239                                         }
 240                                 }
 241
 242                                 memset(&grpsession[g], 0, sizeof(grpsession[0]));
 243                                 grpsession[g].state = GROUPEFREE;
 244                         }
 245                         else
 246                         {
 247                                 // remove the session
 248                                 memmove(&grpsession[g].sesslist[i],
 249                                                 &grpsession[g].sesslist[i+1],
 250                                                 (grpsession[g].nbsession - i) * sizeof(grpsession[g].sesslist[i]));
 251                         }
 252
 253                         cluster_send_groupe(g);
 254                         return;
 255                 }
 256         }
 257 }
 258
 259 // Add a session to a group
 260 // return 1 if OK
 261 static int grp_addsession(groupidt g, sessionidt s, uint8_t weight)
 262 {
 263         int i;
 264
 265         for (i = 0; i < grpsession[g].nbsession; i++)
 266         {
 267                 if (grpsession[g].sesslist[i].sid == s)
 268                 {       // already in group
 269                         if ((!grpsession[g].sesslist[i].weight) || (weight > 1))
 270                                 grpsession[g].sesslist[i].weight = weight; // update Weight session (for load-balancing)
 271
 272                         return 1;
 273                 }
 274         }
 275
 276         if (i >= MAXSESSINGRP)
 277         {
 278                 LOG(1, s, session[s].tunnel, "   Too many session for Group %d\n", g);
 279                 return 0;
 280         }
 281         else
 282         {       // add session id to group
 283                 if (i == 0)
 284                 {
 285                         // it's the first session of the group, set to next group
 286                         grpsession[g].prev = gnextgrpid;
 287                         gnextgrpid = g;
 288                         grpsession[g].state = GROUPEOPEN;
 289                 }
 290                 grpsession[g].sesslist[i].sid = s;
 291                 grpsession[g].sesslist[i].weight = weight;
 292                 grpsession[g].nbsession++;
 293
 294                 return 1;
 295         }
 296         return 0;
 297 }
 298
 299 // Add a route to a group
 300 // return 1 if OK
 301 static int grp_addroute(groupidt g, sessionidt s, in_addr_t ip, int prefixlen)
 302 {
 303         int i;
 304
 305         for (i = 0; i < MAXROUTEINGRP; i++)
 306         {
 307                 if ((i >= grpsession[g].nbroutesgrp))
 308                 {
 309                         LOG(3, s, session[s].tunnel, "   Radius reply Group %d contains route for %s/%d\n",
 310                                 g, fmtaddr(htonl(ip), 0), prefixlen);
 311
 312                         grpsession[g].route[i].ip = ip;
 313                         grpsession[g].route[i].prefixlen = prefixlen;
 314                         grpsession[g].nbroutesgrp++;
 315                         return 1;
 316                 }
 317                 else if ((grpsession[g].route[i].ip == ip) && (grpsession[g].route[i].prefixlen == prefixlen))
 318                 {
 319                         // route already defined in group
 320                         LOG(3, s, session[s].tunnel,
 321                                 "   Radius reply Group %d contains route for %s/%d (this already defined)\n",
 322                                 g, fmtaddr(htonl(ip), 0), prefixlen);
 323
 324                         return 1;
 325                 }
 326                 else if (grpsession[g].route[i].ip == 0)
 327                 {
 328                         LOG(3, s, session[s].tunnel, "   Radius reply Group %d contains route for %s/%d (find empty on list!!!)\n",
 329                                 g, fmtaddr(htonl(ip), 0), prefixlen);
 330
 331                         grpsession[g].route[i].ip = ip;
 332                         grpsession[g].route[i].prefixlen = prefixlen;
 333                         return 1;
 334                 }
 335         }
 336
 337         if (i >= MAXROUTEINGRP)
 338         {
 339                 LOG(1, s, session[s].tunnel, "   Too many routes for Group %d\n", g);
 340         }
 341         return 0;
 342 }
 343
 344 // Process Sames vendor specific attribut radius
 345 void grp_processvendorspecific(sessionidt s, uint8_t *pvs)
 346 {
 347         uint8_t attrib = *pvs;
 348         groupidt grpid = 0;
 349         uint8_t *n = pvs + 2;
 350         uint8_t *e = pvs + pvs[1];
 351
 352         if ((attrib >= 22) && (attrib <= 23))
 353         {
 354                 while (n < e && isdigit(*n))
 355                 {
 356                         grpid = grpid * 10 + *n - '0';
 357                         n++;
 358                 }
 359                 if ((grpid == 0) || (grpid >= MAXGROUPE))
 360                 {
 361                         LOG(1, s, session[s].tunnel, "   Group Attribute Id %d not allowed\n", grpid);
 362                         return;
 363                 }
 364                 else if (*n != ',')
 365                 {
 366                         LOG(1, s, session[s].tunnel, "   Group Attribute Id not defined\n");
 367                         return;
 368                 }
 369
 370                 if (!grp_addsession(grpid, s, 1))
 371                 {
 372                         return;
 373                 }
 374
 375                 if (grpid > config->cluster_highest_groupeid)
 376                         config->cluster_highest_groupeid = grpid;
 377
 378                 n++;
 379         }
 380
 381         //process, Sames vendor-specific 64520
 382         if (attrib == 22) //SAMES-Group-Framed-Route
 383         {
 384                 in_addr_t ip = 0;
 385                 uint8_t u = 0;
 386                 uint8_t bits = 0;
 387
 388                 while (n < e && (isdigit(*n) || *n == '.'))
 389                 {
 390                         if (*n == '.')
 391                         {
 392                                 ip = (ip << 8) + u;
 393                                 u = 0;
 394                         }
 395                         else
 396                                 u = u * 10 + *n - '0';
 397                         n++;
 398                 }
 399                 ip = (ip << 8) + u;
 400                 if (*n == '/')
 401                 {
 402                         n++;
 403                         while (n < e && isdigit(*n))
 404                                 bits = bits * 10 + *n++ - '0';
 405                 }
 406                 else if ((ip >> 24) < 128)
 407                         bits = 8;
 408                 else if ((ip >> 24) < 192)
 409                         bits = 16;
 410                 else
 411                         bits = 24;
 412
 413                 if (!grp_addroute(grpid, s, ip, bits))
 414                         return;
 415         }
 416         else if (attrib == 23) //SAMES-Group-Session-Weight
 417         {
 418                 uint8_t weight = 0;
 419
 420                 while (n < e && isdigit(*n))
 421                         weight = weight * 10 + *n++ - '0';
 422
 423                 if (!weight)
 424                 {
 425                         LOG(1, s, session[s].tunnel, "   Group-Session-Weight 0 GroupId %d not allowed\n", grpid);
 426                         return;
 427                 }
 428                 if (!grp_addsession(grpid, s, weight))
 429                 {
 430                         return;
 431                 }
 432         }
 433         else
 434         {
 435                 LOG(3, s, session[s].tunnel, "   Unknown vendor-specific: 64520, Attrib: %d\n", attrib);
 436         }
 437 }
 438
 439 // Init data structures
 440 void grp_initdata()
 441 {
 442         int i;
 443
 444         // Set default value (10s)
 445         config->grp_txrate_average_time = 10;
 446
 447         if (!(grpsession = shared_malloc(sizeof(groupsesst) * MAXGROUPE)))
 448         {
 449                 LOG(0, 0, 0, "Error doing malloc for grouped session: %s\n", strerror(errno));
 450                 exit(1);
 451         }
 452
 453         memset(grpsession, 0, sizeof(grpsession[0]) * MAXGROUPE);
 454         for (i = 1; i < MAXGROUPE; i++)
 455         {
 456                 grpsession[i].state = GROUPEUNDEF;
 457         }
 458
 459         if (!(grp_local = shared_malloc(sizeof(local_group) * MAXGROUPE)))
 460         {
 461                 LOG(0, 0, 0, "Error doing malloc for grp_local: %s\n", strerror(errno));
 462                 exit(1);
 463         }
 464         memset(grp_local, 0, sizeof(grp_local[0]) * MAXGROUPE);
 465
 466 }
 467
 468 // Update time_changed of the group
 469 void grp_time_changed()
 470 {
 471         groupidt g;
 472
 473         for (g = gnextgrpid; g != 0; g = grpsession[g].prev)
 474         {
 475                 grpsession[g].time_changed++;
 476         }
 477 }
 478
 479 // Uncache all IP of a session
 480 static void grp_uncache_ipsession(groupidt g, sessionidt s)
 481 {
 482         int i;
 483         uint8_t *a;
 484         in_addr_t ip;
 485         in_addr_t n_ip, j;
 486         int prefixlen;
 487         union iphash *h;
 488
 489         for (i = 0; i < grpsession[g].nbroutesgrp; i++)
 490         {
 491                 if (grpsession[g].route[i].ip != 0)
 492                 {
 493                         prefixlen = grpsession[g].route[i].prefixlen;
 494                         ip = grpsession[g].route[i].ip & (0xffffffff << (32 - prefixlen));      // Force the ip to be the first one in the route.
 495
 496                         for (j = ip; j < ip+(1<<(32-prefixlen)) ; ++j)
 497                         {
 498                                 n_ip = htonl(j); // To network order
 499                                 a = (uint8_t *) &n_ip;
 500                                 h = ip_hash;
 501
 502                                 if (!(h = h[*a++].idx)) continue;
 503                                 if (!(h = h[*a++].idx)) continue;
 504                                 if (!(h = h[*a++].idx)) continue;
 505
 506                                 if (s == h[*a].sess)
 507                                 {
 508                                         h[*a].sess = 0;
 509                                         //LOG(3, s, session[s].tunnel, "UnCaching ip address %s\n", fmtaddr(n_ip, 0));
 510                                 }
 511                         }
 512                 }
 513         }
 514 }
 515
 516 // return the next session can be used on the group
 517 sessionidt grp_getnextsession(groupidt g, in_addr_t ip, in_addr_t ip_src)
 518 {
 519         sessionidt s = 0, s2 = 0, s3 = 0;
 520         int i;
 521         uint32_t ltime_changed = 0, mintxrate = 0xFFFFFFFF, maxtxrate = 0;
 522         uint32_t txrate;
 523
 524         if (g >= MAXGROUPE)
 525                 return 0;
 526
 527         if (grpsession[g].time_changed >= config->grp_txrate_average_time)
 528         {
 529                 // recalculation txrate
 530                 ltime_changed = grpsession[g].time_changed;
 531                 grpsession[g].time_changed = 0;
 532                 for (i = 0; i < grpsession[g].nbsession; i++)
 533                 {
 534                         if ((s2 = grpsession[g].sesslist[i].sid))
 535                         {
 536                                 uint32_t coutgrp_delta = 0;
 537
 538                                 if (session[s2].cout >= grpsession[g].sesslist[i].prev_coutgrp)
 539                                         coutgrp_delta = session[s2].cout - grpsession[g].sesslist[i].prev_coutgrp;
 540                                 grpsession[g].sesslist[i].prev_coutgrp = session[s2].cout;
 541
 542                                 grpsession[g].sesslist[i].tx_rate = coutgrp_delta/ltime_changed;
 543
 544                                 txrate = grpsession[g].sesslist[i].tx_rate/grpsession[g].sesslist[i].weight;
 545                                 if (txrate < mintxrate)
 546                                 {
 547                                         if ( session[s2].ppp.phase > Establish &&
 548                                                 (time_now - session[s2].last_packet <= (config->echo_timeout + 1)) )
 549                                         {
 550                                                 grpsession[g].smin = s2;
 551                                                 mintxrate = txrate;
 552                                         }
 553                                 }
 554
 555                                 if (txrate > maxtxrate)
 556                                 {
 557                                         if ( session[s2].ppp.phase > Establish &&
 558                                         (time_now - session[s2].last_packet <= (config->echo_timeout + 1)) )
 559                                         {
 560                                                 grpsession[g].smax = s2;
 561                                                 maxtxrate = txrate;
 562                                         }
 563                                 }
 564                         }
 565                 }
 566         }
 567
 568         if ((s = sessionbyip(ip)))
 569         {
 570                 uint8_t *as = (uint8_t *) &ip_src;
 571                 uint8_t *ad = (uint8_t *) &ip;
 572                 uint16_t ai = ad[3];
 573                 ai <<= 8;
 574                 ai |= as[3];
 575
 576                 s = grp_local[g].sid_loaddist[ai];
 577                 if (!s)
 578                 {
 579                         s = grpsession[g].smin;
 580                         grp_local[g].sid_loaddist[ai] = s;
 581                 }
 582
 583                 if (g != grp_groupbysession(s))
 584                 {
 585                         // This session does not belong to this group
 586                         LOG(2, s, session[s].tunnel, "Warning, the session does not belong to group %d\n", g);
 587                         s = 0;
 588                         grp_local[g].sid_loaddist[ai] = 0;
 589                 }
 590                 else if (s == grpsession[g].smax)
 591                 {
 592                         s = grpsession[g].smin;
 593                         grp_local[g].sid_loaddist[ai] = s;
 594                         grpsession[g].smax = 0;
 595                 }
 596                 else if ( (session[s].ppp.phase > Establish) &&
 597                          (time_now - session[s].last_packet <= (config->echo_timeout + 1)) )
 598                 {
 599                         return s;
 600                 }
 601                 else
 602                 {
 603                         s = 0;
 604                         grp_local[g].sid_loaddist[ai] = 0;
 605                 }
 606         }
 607
 608         if (!s)
 609         {
 610                 // random between 0 and nbsession-1
 611                 uint indexsess = (rand() % grpsession[g].nbsession);
 612
 613                 if (indexsess >= grpsession[g].nbsession)
 614                         indexsess = 0; //Sanity checks.
 615
 616                 s2 = grpsession[g].sesslist[indexsess].sid;
 617                 if (s2 &&
 618                         (session[s2].ppp.phase > Establish) &&
 619                         (time_now - session[s2].last_packet <= (config->echo_timeout + 1)))
 620                 {
 621                         s = s2;
 622                 }
 623                 else
 624                 {
 625                         for (i = 0; i < grpsession[g].nbsession; i++)
 626                         {
 627                                 if ((s2 = grpsession[g].sesslist[i].sid))
 628                                 {
 629                                         s3 = s2;
 630
 631                                         if ( session[s2].ppp.phase > Establish &&
 632                                                 (time_now - session[s2].last_packet <= (config->echo_timeout + 1)) )
 633                                         {
 634                                                 s = s2;
 635                                                 break;
 636                                         }
 637                                 }
 638                         }
 639                 }
 640         }
 641
 642         if (!s)
 643                 s = s3;
 644
 645         if (s)
 646                 cache_ipmap(ntohl(ip), s);
 647
 648         return s;
 649 }
 650
 651 // load a groupe receive from master
 652 int grp_cluster_load_groupe(groupidt g, groupsesst *new)
 653 {
 654         int i;
 655         int updategroup = 0;
 656
 657         if (g >= MAXGROUPE)
 658         {
 659                 LOG(0, 0, 0, "ERROR: Received a group id > MAXGROUPE!\n");
 660                 return 0;
 661         }
 662
 663         if ((grpsession[g].nbroutesgrp != new->nbroutesgrp) ||
 664                 (grpsession[g].nbsession != new->nbsession))
 665         {
 666                 updategroup = 1;
 667         }
 668
 669         if (!updategroup)
 670         {
 671                 // Check session list
 672                 for (i = 0; i < grpsession[g].nbsession; i++)
 673                 {
 674                         if (grpsession[g].sesslist[i].sid != new->sesslist[i].sid)
 675                         {
 676                                 updategroup = 1;
 677                                 break;
 678                         }
 679                 }
 680         }
 681
 682         if (!updategroup)
 683         {
 684                 // Check routes list
 685                 for (i = 0; i < grpsession[g].nbroutesgrp; i++)
 686                 {
 687                         if (grpsession[g].route[i].ip != new->route[i].ip)
 688                         {
 689                                 updategroup = 1;
 690                                 break;
 691                         }
 692                 }
 693         }
 694
 695         // needs update
 696         if (updategroup)
 697         {
 698                 // Del all routes
 699                 grp_setgrouproute(g, 0);
 700         }
 701
 702         memcpy(&grpsession[g], new, sizeof(grpsession[g]));     // Copy over..
 703
 704         // needs update
 705         if (updategroup)
 706         {
 707                 // Add all routes
 708                 grp_setgrouproute(g, 1);
 709         }
 710
 711         return 1;
 712 }