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