lib/bundle.c

   1 /* Copyright (c) 2011, 2012 Nicira, Inc.
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include <config.h>
  17
  18 #include "bundle.h"
  19
  20 #include <arpa/inet.h>
  21 #include <inttypes.h>
  22
  23 #include "dynamic-string.h"
  24 #include "multipath.h"
  25 #include "meta-flow.h"
  26 #include "nx-match.h"
  27 #include "ofpbuf.h"
  28 #include "ofp-actions.h"
  29 #include "ofp-errors.h"
  30 #include "ofp-util.h"
  31 #include "openflow/nicira-ext.h"
  32 #include "vlog.h"
  33
  34 #define BUNDLE_MAX_SLAVES 2048
  35
  36 VLOG_DEFINE_THIS_MODULE(bundle);
  37
  38 static uint16_t
  39 execute_ab(const struct ofpact_bundle *bundle,
  40            bool (*slave_enabled)(uint16_t ofp_port, void *aux), void *aux)
  41 {
  42     size_t i;
  43
  44     for (i = 0; i < bundle->n_slaves; i++) {
  45         uint16_t slave = bundle->slaves[i];
  46         if (slave_enabled(slave, aux)) {
  47             return slave;
  48         }
  49     }
  50
  51     return OFPP_NONE;
  52 }
  53
  54 static uint16_t
  55 execute_hrw(const struct ofpact_bundle *bundle,
  56             const struct flow *flow, struct flow_wildcards *wc,
  57             bool (*slave_enabled)(uint16_t ofp_port, void *aux), void *aux)
  58 {
  59     uint32_t flow_hash, best_hash;
  60     int best, i;
  61
  62     if (bundle->n_slaves > 1) {
  63         flow_mask_hash_fields(wc, bundle->fields);
  64     }
  65
  66     flow_hash = flow_hash_fields(flow, bundle->fields, bundle->basis);
  67     best = -1;
  68     best_hash = 0;
  69
  70     for (i = 0; i < bundle->n_slaves; i++) {
  71         if (slave_enabled(bundle->slaves[i], aux)) {
  72             uint32_t hash = hash_2words(i, flow_hash);
  73
  74             if (best < 0 || hash > best_hash) {
  75                 best_hash = hash;
  76                 best = i;
  77             }
  78         }
  79     }
  80
  81     return best >= 0 ? bundle->slaves[best] : OFPP_NONE;
  82 }
  83
  84 /* Executes 'bundle' on 'flow'.  Sets fields in 'wc' that were used to
  85  * calculate the result.  Uses 'slave_enabled' to determine if the slave
  86  * designated by 'ofp_port' is up.  Returns the chosen slave, or
  87  * OFPP_NONE if none of the slaves are acceptable. */
  88 uint16_t
  89 bundle_execute(const struct ofpact_bundle *bundle,
  90                const struct flow *flow, struct flow_wildcards *wc,
  91                bool (*slave_enabled)(uint16_t ofp_port, void *aux), void *aux)
  92 {
  93     switch (bundle->algorithm) {
  94     case NX_BD_ALG_HRW:
  95         return execute_hrw(bundle, flow, wc, slave_enabled, aux);
  96
  97     case NX_BD_ALG_ACTIVE_BACKUP:
  98         return execute_ab(bundle, slave_enabled, aux);
  99
 100     default:
 101         NOT_REACHED();
 102     }
 103 }
 104
 105 /* Checks that 'nab' specifies a bundle action which is supported by this
 106  * bundle module.  Uses the 'max_ports' parameter to validate each port using
 107  * ofputil_check_output_port().  Returns 0 if 'nab' is supported, otherwise an
 108  * OFPERR_* error code. */
 109 enum ofperr
 110 bundle_from_openflow(const struct nx_action_bundle *nab,
 111                      struct ofpbuf *ofpacts)
 112 {
 113     static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
 114     struct ofpact_bundle *bundle;
 115     uint16_t subtype;
 116     uint32_t slave_type;
 117     size_t slaves_size, i;
 118     enum ofperr error;
 119
 120     bundle = ofpact_put_BUNDLE(ofpacts);
 121
 122     subtype = ntohs(nab->subtype);
 123     bundle->n_slaves = ntohs(nab->n_slaves);
 124     bundle->basis = ntohs(nab->basis);
 125     bundle->fields = ntohs(nab->fields);
 126     bundle->algorithm = ntohs(nab->algorithm);
 127     slave_type = ntohl(nab->slave_type);
 128     slaves_size = ntohs(nab->len) - sizeof *nab;
 129
 130     error = OFPERR_OFPBAC_BAD_ARGUMENT;
 131     if (!flow_hash_fields_valid(bundle->fields)) {
 132         VLOG_WARN_RL(&rl, "unsupported fields %d", (int) bundle->fields);
 133     } else if (bundle->n_slaves > BUNDLE_MAX_SLAVES) {
 134         VLOG_WARN_RL(&rl, "too may slaves");
 135     } else if (bundle->algorithm != NX_BD_ALG_HRW
 136                && bundle->algorithm != NX_BD_ALG_ACTIVE_BACKUP) {
 137         VLOG_WARN_RL(&rl, "unsupported algorithm %d", (int) bundle->algorithm);
 138     } else if (slave_type != NXM_OF_IN_PORT) {
 139         VLOG_WARN_RL(&rl, "unsupported slave type %"PRIu16, slave_type);
 140     } else {
 141         error = 0;
 142     }
 143
 144     if (!is_all_zeros(nab->zero, sizeof nab->zero)) {
 145         VLOG_WARN_RL(&rl, "reserved field is nonzero");
 146         error = OFPERR_OFPBAC_BAD_ARGUMENT;
 147     }
 148
 149     if (subtype == NXAST_BUNDLE && (nab->ofs_nbits || nab->dst)) {
 150         VLOG_WARN_RL(&rl, "bundle action has nonzero reserved fields");
 151         error = OFPERR_OFPBAC_BAD_ARGUMENT;
 152     }
 153
 154     if (subtype == NXAST_BUNDLE_LOAD) {
 155         bundle->dst.field = mf_from_nxm_header(ntohl(nab->dst));
 156         bundle->dst.ofs = nxm_decode_ofs(nab->ofs_nbits);
 157         bundle->dst.n_bits = nxm_decode_n_bits(nab->ofs_nbits);
 158
 159         if (bundle->dst.n_bits < 16) {
 160             VLOG_WARN_RL(&rl, "bundle_load action requires at least 16 bit "
 161                          "destination.");
 162             error = OFPERR_OFPBAC_BAD_ARGUMENT;
 163         }
 164     }
 165
 166     if (slaves_size < bundle->n_slaves * sizeof(ovs_be16)) {
 167         VLOG_WARN_RL(&rl, "Nicira action %"PRIu16" only has %zu bytes "
 168                      "allocated for slaves.  %zu bytes are required for "
 169                      "%"PRIu16" slaves.", subtype, slaves_size,
 170                      bundle->n_slaves * sizeof(ovs_be16), bundle->n_slaves);
 171         error = OFPERR_OFPBAC_BAD_LEN;
 172     }
 173
 174     for (i = 0; i < bundle->n_slaves; i++) {
 175         uint16_t ofp_port = ntohs(((ovs_be16 *)(nab + 1))[i]);
 176         ofpbuf_put(ofpacts, &ofp_port, sizeof ofp_port);
 177     }
 178
 179     bundle = ofpacts->l2;
 180     ofpact_update_len(ofpacts, &bundle->ofpact);
 181
 182     if (!error) {
 183         error = bundle_check(bundle, OFPP_MAX, NULL);
 184     }
 185     return error;
 186 }
 187
 188 enum ofperr
 189 bundle_check(const struct ofpact_bundle *bundle, int max_ports,
 190              const struct flow *flow)
 191 {
 192     static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
 193     size_t i;
 194
 195     if (bundle->dst.field) {
 196         enum ofperr error = mf_check_dst(&bundle->dst, flow);
 197         if (error) {
 198             return error;
 199         }
 200     }
 201
 202     for (i = 0; i < bundle->n_slaves; i++) {
 203         uint16_t ofp_port = bundle->slaves[i];
 204         enum ofperr error;
 205
 206         error = ofputil_check_output_port(ofp_port, max_ports);
 207         if (error) {
 208             VLOG_WARN_RL(&rl, "invalid slave %"PRIu16, ofp_port);
 209             return error;
 210         }
 211
 212         /* Controller slaves are unsupported due to the lack of a max_len
 213          * argument. This may or may not change in the future.  There doesn't
 214          * seem to be a real-world use-case for supporting it. */
 215         if (ofp_port == OFPP_CONTROLLER) {
 216             VLOG_WARN_RL(&rl, "unsupported controller slave");
 217             return OFPERR_OFPBAC_BAD_OUT_PORT;
 218         }
 219     }
 220
 221     return 0;
 222 }
 223
 224 void
 225 bundle_to_nxast(const struct ofpact_bundle *bundle, struct ofpbuf *openflow)
 226 {
 227     int slaves_len = ROUND_UP(2 * bundle->n_slaves, OFP_ACTION_ALIGN);
 228     struct nx_action_bundle *nab;
 229     ovs_be16 *slaves;
 230     size_t i;
 231
 232     nab = (bundle->dst.field
 233            ? ofputil_put_NXAST_BUNDLE_LOAD(openflow)
 234            : ofputil_put_NXAST_BUNDLE(openflow));
 235     nab->len = htons(ntohs(nab->len) + slaves_len);
 236     nab->algorithm = htons(bundle->algorithm);
 237     nab->fields = htons(bundle->fields);
 238     nab->basis = htons(bundle->basis);
 239     nab->slave_type = htonl(NXM_OF_IN_PORT);
 240     nab->n_slaves = htons(bundle->n_slaves);
 241     if (bundle->dst.field) {
 242         nab->ofs_nbits = nxm_encode_ofs_nbits(bundle->dst.ofs,
 243                                               bundle->dst.n_bits);
 244         nab->dst = htonl(bundle->dst.field->nxm_header);
 245     }
 246
 247     slaves = ofpbuf_put_zeros(openflow, slaves_len);
 248     for (i = 0; i < bundle->n_slaves; i++) {
 249         slaves[i] = htons(bundle->slaves[i]);
 250     }
 251 }
 252
 253 /* Helper for bundle_parse and bundle_parse_load. */
 254 static void
 255 bundle_parse__(const char *s, char **save_ptr,
 256                const char *fields, const char *basis, const char *algorithm,
 257                const char *slave_type, const char *dst,
 258                const char *slave_delim, struct ofpbuf *ofpacts)
 259 {
 260     struct ofpact_bundle *bundle;
 261
 262     if (!slave_delim) {
 263         ovs_fatal(0, "%s: not enough arguments to bundle action", s);
 264     }
 265
 266     if (strcasecmp(slave_delim, "slaves")) {
 267         ovs_fatal(0, "%s: missing slave delimiter, expected `slaves' got `%s'",
 268                    s, slave_delim);
 269     }
 270
 271     bundle = ofpact_put_BUNDLE(ofpacts);
 272
 273     for (;;) {
 274         uint16_t slave_port;
 275         char *slave;
 276
 277         slave = strtok_r(NULL, ", []", save_ptr);
 278         if (!slave || bundle->n_slaves >= BUNDLE_MAX_SLAVES) {
 279             break;
 280         }
 281
 282         if (!ofputil_port_from_string(slave, &slave_port)) {
 283             ovs_fatal(0, "%s: bad port number", slave);
 284         }
 285         ofpbuf_put(ofpacts, &slave_port, sizeof slave_port);
 286
 287         bundle = ofpacts->l2;
 288         bundle->n_slaves++;
 289     }
 290     ofpact_update_len(ofpacts, &bundle->ofpact);
 291
 292     bundle->basis = atoi(basis);
 293
 294     if (!strcasecmp(fields, "eth_src")) {
 295         bundle->fields = NX_HASH_FIELDS_ETH_SRC;
 296     } else if (!strcasecmp(fields, "symmetric_l4")) {
 297         bundle->fields = NX_HASH_FIELDS_SYMMETRIC_L4;
 298     } else {
 299         ovs_fatal(0, "%s: unknown fields `%s'", s, fields);
 300     }
 301
 302     if (!strcasecmp(algorithm, "active_backup")) {
 303         bundle->algorithm = NX_BD_ALG_ACTIVE_BACKUP;
 304     } else if (!strcasecmp(algorithm, "hrw")) {
 305         bundle->algorithm = NX_BD_ALG_HRW;
 306     } else {
 307         ovs_fatal(0, "%s: unknown algorithm `%s'", s, algorithm);
 308     }
 309
 310     if (strcasecmp(slave_type, "ofport")) {
 311         ovs_fatal(0, "%s: unknown slave_type `%s'", s, slave_type);
 312     }
 313
 314     if (dst) {
 315         mf_parse_subfield(&bundle->dst, dst);
 316     }
 317 }
 318
 319 /* Converts a bundle action string contained in 's' to an nx_action_bundle and
 320  * stores it in 'b'.  Sets 'b''s l2 pointer to NULL. */
 321 void
 322 bundle_parse(const char *s, struct ofpbuf *ofpacts)
 323 {
 324     char *fields, *basis, *algorithm, *slave_type, *slave_delim;
 325     char *tokstr, *save_ptr;
 326
 327     save_ptr = NULL;
 328     tokstr = xstrdup(s);
 329     fields = strtok_r(tokstr, ", ", &save_ptr);
 330     basis = strtok_r(NULL, ", ", &save_ptr);
 331     algorithm = strtok_r(NULL, ", ", &save_ptr);
 332     slave_type = strtok_r(NULL, ", ", &save_ptr);
 333     slave_delim = strtok_r(NULL, ": ", &save_ptr);
 334
 335     bundle_parse__(s, &save_ptr, fields, basis, algorithm, slave_type, NULL,
 336                    slave_delim, ofpacts);
 337     free(tokstr);
 338 }
 339
 340 /* Converts a bundle_load action string contained in 's' to an nx_action_bundle
 341  * and stores it in 'b'.  Sets 'b''s l2 pointer to NULL. */
 342 void
 343 bundle_parse_load(const char *s, struct ofpbuf *ofpacts)
 344 {
 345     char *fields, *basis, *algorithm, *slave_type, *dst, *slave_delim;
 346     char *tokstr, *save_ptr;
 347
 348     save_ptr = NULL;
 349     tokstr = xstrdup(s);
 350     fields = strtok_r(tokstr, ", ", &save_ptr);
 351     basis = strtok_r(NULL, ", ", &save_ptr);
 352     algorithm = strtok_r(NULL, ", ", &save_ptr);
 353     slave_type = strtok_r(NULL, ", ", &save_ptr);
 354     dst = strtok_r(NULL, ", ", &save_ptr);
 355     slave_delim = strtok_r(NULL, ": ", &save_ptr);
 356
 357     bundle_parse__(s, &save_ptr, fields, basis, algorithm, slave_type, dst,
 358                    slave_delim, ofpacts);
 359
 360     free(tokstr);
 361 }
 362
 363 /* Appends a human-readable representation of 'nab' to 's'. */
 364 void
 365 bundle_format(const struct ofpact_bundle *bundle, struct ds *s)
 366 {
 367     const char *action, *fields, *algorithm;
 368     size_t i;
 369
 370     fields = flow_hash_fields_to_str(bundle->fields);
 371
 372     switch (bundle->algorithm) {
 373     case NX_BD_ALG_HRW:
 374         algorithm = "hrw";
 375         break;
 376     case NX_BD_ALG_ACTIVE_BACKUP:
 377         algorithm = "active_backup";
 378         break;
 379     default:
 380         algorithm = "<unknown>";
 381     }
 382
 383     action = bundle->dst.field ? "bundle_load" : "bundle";
 384
 385     ds_put_format(s, "%s(%s,%"PRIu16",%s,%s,", action, fields,
 386                   bundle->basis, algorithm, "ofport");
 387
 388     if (bundle->dst.field) {
 389         mf_format_subfield(&bundle->dst, s);
 390         ds_put_cstr(s, ",");
 391     }
 392
 393     ds_put_cstr(s, "slaves:");
 394     for (i = 0; i < bundle->n_slaves; i++) {
 395         if (i) {
 396             ds_put_cstr(s, ",");
 397         }
 398
 399         ofputil_format_port(bundle->slaves[i], s);
 400     }
 401
 402     ds_put_cstr(s, ")");
 403 }