lib/bundle.c

   1 /* Copyright (c) 2011, 2012 Nicira Networks.
   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 "nx-match.h"
  26 #include "ofpbuf.h"
  27 #include "ofp-errors.h"
  28 #include "ofp-util.h"
  29 #include "openflow/nicira-ext.h"
  30 #include "vlog.h"
  31
  32 #define BUNDLE_MAX_SLAVES 2048
  33
  34 VLOG_DEFINE_THIS_MODULE(bundle);
  35
  36 static uint16_t
  37 execute_ab(const struct nx_action_bundle *nab,
  38            bool (*slave_enabled)(uint16_t ofp_port, void *aux), void *aux)
  39 {
  40     size_t i;
  41
  42     for (i = 0; i < ntohs(nab->n_slaves); i++) {
  43         uint16_t slave = bundle_get_slave(nab, i);
  44
  45         if (slave_enabled(slave, aux)) {
  46             return slave;
  47         }
  48     }
  49
  50     return OFPP_NONE;
  51 }
  52
  53 static uint16_t
  54 execute_hrw(const struct nx_action_bundle *nab, const struct flow *flow,
  55             bool (*slave_enabled)(uint16_t ofp_port, void *aux), void *aux)
  56 {
  57     uint32_t flow_hash, best_hash;
  58     int best, i;
  59
  60     flow_hash = flow_hash_fields(flow, ntohs(nab->fields), ntohs(nab->basis));
  61     best = -1;
  62     best_hash = 0;
  63
  64     for (i = 0; i < ntohs(nab->n_slaves); i++) {
  65         if (slave_enabled(bundle_get_slave(nab, i), aux)) {
  66             uint32_t hash = hash_2words(i, flow_hash);
  67
  68             if (best < 0 || hash > best_hash) {
  69                 best_hash = hash;
  70                 best = i;
  71             }
  72         }
  73     }
  74
  75     return best >= 0 ? bundle_get_slave(nab, best) : OFPP_NONE;
  76 }
  77
  78 /* Executes 'nab' on 'flow'.  Uses 'slave_enabled' to determine if the slave
  79  * designated by 'ofp_port' is up.  Returns the chosen slave, or OFPP_NONE if
  80  * none of the slaves are acceptable. */
  81 uint16_t
  82 bundle_execute(const struct nx_action_bundle *nab, const struct flow *flow,
  83                bool (*slave_enabled)(uint16_t ofp_port, void *aux), void *aux)
  84 {
  85     switch (ntohs(nab->algorithm)) {
  86     case NX_BD_ALG_HRW: return execute_hrw(nab, flow, slave_enabled, aux);
  87     case NX_BD_ALG_ACTIVE_BACKUP: return execute_ab(nab, slave_enabled, aux);
  88     default: NOT_REACHED();
  89     }
  90 }
  91
  92 void
  93 bundle_execute_load(const struct nx_action_bundle *nab, struct flow *flow,
  94                     bool (*slave_enabled)(uint16_t ofp_port, void *aux),
  95                     void *aux)
  96 {
  97     nxm_reg_load(nab->dst, nab->ofs_nbits,
  98                  bundle_execute(nab, flow, slave_enabled, aux), flow);
  99 }
 100
 101 /* Checks that 'nab' specifies a bundle action which is supported by this
 102  * bundle module.  Uses the 'max_ports' parameter to validate each port using
 103  * ofputil_check_output_port().  Returns 0 if 'nab' is supported, otherwise an
 104  * OFPERR_* error code. */
 105 enum ofperr
 106 bundle_check(const struct nx_action_bundle *nab, int max_ports,
 107              const struct flow *flow)
 108 {
 109     static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
 110     uint16_t n_slaves, fields, algorithm, subtype;
 111     uint32_t slave_type;
 112     size_t slaves_size, i;
 113     enum ofperr error;
 114
 115     subtype = ntohs(nab->subtype);
 116     n_slaves = ntohs(nab->n_slaves);
 117     fields = ntohs(nab->fields);
 118     algorithm = ntohs(nab->algorithm);
 119     slave_type = ntohl(nab->slave_type);
 120     slaves_size = ntohs(nab->len) - sizeof *nab;
 121
 122     error = OFPERR_OFPBAC_BAD_ARGUMENT;
 123     if (!flow_hash_fields_valid(fields)) {
 124         VLOG_WARN_RL(&rl, "unsupported fields %"PRIu16, fields);
 125     } else if (n_slaves > BUNDLE_MAX_SLAVES) {
 126         VLOG_WARN_RL(&rl, "too may slaves");
 127     } else if (algorithm != NX_BD_ALG_HRW
 128                && algorithm != NX_BD_ALG_ACTIVE_BACKUP) {
 129         VLOG_WARN_RL(&rl, "unsupported algorithm %"PRIu16, algorithm);
 130     } else if (slave_type != NXM_OF_IN_PORT) {
 131         VLOG_WARN_RL(&rl, "unsupported slave type %"PRIu16, slave_type);
 132     } else {
 133         error = 0;
 134     }
 135
 136     for (i = 0; i < sizeof(nab->zero); i++) {
 137         if (nab->zero[i]) {
 138             VLOG_WARN_RL(&rl, "reserved field is nonzero");
 139             error = OFPERR_OFPBAC_BAD_ARGUMENT;
 140         }
 141     }
 142
 143     if (subtype == NXAST_BUNDLE && (nab->ofs_nbits || nab->dst)) {
 144         VLOG_WARN_RL(&rl, "bundle action has nonzero reserved fields");
 145         error = OFPERR_OFPBAC_BAD_ARGUMENT;
 146     }
 147
 148     if (subtype == NXAST_BUNDLE_LOAD) {
 149         int ofs = nxm_decode_ofs(nab->ofs_nbits);
 150         int n_bits = nxm_decode_n_bits(nab->ofs_nbits);
 151
 152         if (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         } else if (!error) {
 157             error = nxm_dst_check(nab->dst, ofs, n_bits, flow);
 158         }
 159     }
 160
 161     if (slaves_size < n_slaves * sizeof(ovs_be16)) {
 162         VLOG_WARN_RL(&rl, "Nicira action %"PRIu16" only has %zu bytes "
 163                      "allocated for slaves.  %zu bytes are required for "
 164                      "%"PRIu16" slaves.", subtype, slaves_size,
 165                      n_slaves * sizeof(ovs_be16), n_slaves);
 166         error = OFPERR_OFPBAC_BAD_LEN;
 167     }
 168
 169     for (i = 0; i < n_slaves; i++) {
 170         uint16_t ofp_port = bundle_get_slave(nab, i);
 171         enum ofperr ofputil_error;
 172
 173         ofputil_error = ofputil_check_output_port(ofp_port, max_ports);
 174         if (ofputil_error) {
 175             VLOG_WARN_RL(&rl, "invalid slave %"PRIu16, ofp_port);
 176             error = ofputil_error;
 177         }
 178
 179         /* Controller slaves are unsupported due to the lack of a max_len
 180          * argument. This may or may not change in the future.  There doesn't
 181          * seem to be a real-world use-case for supporting it. */
 182         if (ofp_port == OFPP_CONTROLLER) {
 183             VLOG_WARN_RL(&rl, "unsupported controller slave");
 184             error = OFPERR_OFPBAC_BAD_OUT_PORT;
 185         }
 186     }
 187
 188     return error;
 189 }
 190
 191 /* Helper for bundle_parse and bundle_parse_load. */
 192 static void
 193 bundle_parse__(struct ofpbuf *b, const char *s, char **save_ptr,
 194                const char *fields, const char *basis, const char *algorithm,
 195                const char *slave_type, const char *dst,
 196                const char *slave_delim)
 197 {
 198     enum ofputil_action_code code;
 199     struct nx_action_bundle *nab;
 200     uint16_t n_slaves;
 201
 202     if (!slave_delim) {
 203         ovs_fatal(0, "%s: not enough arguments to bundle action", s);
 204     }
 205
 206     if (strcasecmp(slave_delim, "slaves")) {
 207         ovs_fatal(0, "%s: missing slave delimiter, expected `slaves' got `%s'",
 208                    s, slave_delim);
 209     }
 210
 211     code = dst ? OFPUTIL_NXAST_BUNDLE_LOAD : OFPUTIL_NXAST_BUNDLE;
 212     b->l2 = ofputil_put_action(code, b);
 213
 214     n_slaves = 0;
 215     for (;;) {
 216         ovs_be16 slave_be;
 217         char *slave;
 218
 219         slave = strtok_r(NULL, ", [", save_ptr);
 220         if (!slave || n_slaves >= BUNDLE_MAX_SLAVES) {
 221             break;
 222         }
 223
 224         slave_be = htons(atoi(slave));
 225         ofpbuf_put(b, &slave_be, sizeof slave_be);
 226
 227         n_slaves++;
 228     }
 229
 230     /* Slaves array must be multiple of 8 bytes long. */
 231     if (b->size % 8) {
 232         ofpbuf_put_zeros(b, 8 - (b->size % 8));
 233     }
 234
 235     nab = b->l2;
 236     nab->len = htons(b->size - ((char *) b->l2 - (char *) b->data));
 237     nab->n_slaves = htons(n_slaves);
 238     nab->basis = htons(atoi(basis));
 239
 240     if (!strcasecmp(fields, "eth_src")) {
 241         nab->fields = htons(NX_HASH_FIELDS_ETH_SRC);
 242     } else if (!strcasecmp(fields, "symmetric_l4")) {
 243         nab->fields = htons(NX_HASH_FIELDS_SYMMETRIC_L4);
 244     } else {
 245         ovs_fatal(0, "%s: unknown fields `%s'", s, fields);
 246     }
 247
 248     if (!strcasecmp(algorithm, "active_backup")) {
 249         nab->algorithm = htons(NX_BD_ALG_ACTIVE_BACKUP);
 250     } else if (!strcasecmp(algorithm, "hrw")) {
 251         nab->algorithm = htons(NX_BD_ALG_HRW);
 252     } else {
 253         ovs_fatal(0, "%s: unknown algorithm `%s'", s, algorithm);
 254     }
 255
 256     if (!strcasecmp(slave_type, "ofport")) {
 257         nab->slave_type = htonl(NXM_OF_IN_PORT);
 258     } else {
 259         ovs_fatal(0, "%s: unknown slave_type `%s'", s, slave_type);
 260     }
 261
 262     if (dst) {
 263         uint32_t reg;
 264         int ofs, n_bits;
 265
 266         nxm_parse_field_bits(dst, &reg, &ofs, &n_bits);
 267
 268         nab->dst = htonl(reg);
 269         nab->ofs_nbits = nxm_encode_ofs_nbits(ofs, n_bits);
 270     }
 271
 272     b->l2 = NULL;
 273 }
 274
 275 /* Converts a bundle action string contained in 's' to an nx_action_bundle and
 276  * stores it in 'b'.  Sets 'b''s l2 pointer to NULL. */
 277 void
 278 bundle_parse(struct ofpbuf *b, const char *s)
 279 {
 280     char *fields, *basis, *algorithm, *slave_type, *slave_delim;
 281     char *tokstr, *save_ptr;
 282
 283     save_ptr = NULL;
 284     tokstr = xstrdup(s);
 285     fields = strtok_r(tokstr, ", ", &save_ptr);
 286     basis = strtok_r(NULL, ", ", &save_ptr);
 287     algorithm = strtok_r(NULL, ", ", &save_ptr);
 288     slave_type = strtok_r(NULL, ", ", &save_ptr);
 289     slave_delim = strtok_r(NULL, ": ", &save_ptr);
 290
 291     bundle_parse__(b, s, &save_ptr, fields, basis, algorithm, slave_type, NULL,
 292                    slave_delim);
 293     free(tokstr);
 294 }
 295
 296 /* Converts a bundle_load action string contained in 's' to an nx_action_bundle
 297  * and stores it in 'b'.  Sets 'b''s l2 pointer to NULL. */
 298 void
 299 bundle_parse_load(struct ofpbuf *b, const char *s)
 300 {
 301     char *fields, *basis, *algorithm, *slave_type, *dst, *slave_delim;
 302     char *tokstr, *save_ptr;
 303
 304     save_ptr = NULL;
 305     tokstr = xstrdup(s);
 306     fields = strtok_r(tokstr, ", ", &save_ptr);
 307     basis = strtok_r(NULL, ", ", &save_ptr);
 308     algorithm = strtok_r(NULL, ", ", &save_ptr);
 309     slave_type = strtok_r(NULL, ", ", &save_ptr);
 310     dst = strtok_r(NULL, ", ", &save_ptr);
 311     slave_delim = strtok_r(NULL, ": ", &save_ptr);
 312
 313     bundle_parse__(b, s, &save_ptr, fields, basis, algorithm, slave_type, dst,
 314                    slave_delim);
 315
 316     free(tokstr);
 317 }
 318
 319 /* Appends a human-readable representation of 'nab' to 's'. */
 320 void
 321 bundle_format(const struct nx_action_bundle *nab, struct ds *s)
 322 {
 323     const char *action, *fields, *algorithm, *slave_type;
 324     size_t i;
 325
 326     fields = flow_hash_fields_to_str(ntohs(nab->fields));
 327
 328     switch (ntohs(nab->algorithm)) {
 329     case NX_BD_ALG_HRW:
 330         algorithm = "hrw";
 331         break;
 332     case NX_BD_ALG_ACTIVE_BACKUP:
 333         algorithm = "active_backup";
 334         break;
 335     default:
 336         algorithm = "<unknown>";
 337     }
 338
 339     switch (ntohl(nab->slave_type)) {
 340     case NXM_OF_IN_PORT:
 341         slave_type = "ofport";
 342         break;
 343     default:
 344         slave_type = "<unknown>";
 345     }
 346
 347     switch (ntohs(nab->subtype)) {
 348     case NXAST_BUNDLE:
 349         action = "bundle";
 350         break;
 351     case NXAST_BUNDLE_LOAD:
 352         action = "bundle_load";
 353         break;
 354     default:
 355         NOT_REACHED();
 356     }
 357
 358     ds_put_format(s, "%s(%s,%"PRIu16",%s,%s,", action, fields,
 359                   ntohs(nab->basis), algorithm, slave_type);
 360
 361     if (nab->subtype == htons(NXAST_BUNDLE_LOAD)) {
 362         nxm_format_field_bits(s, ntohl(nab->dst),
 363                               nxm_decode_ofs(nab->ofs_nbits),
 364                               nxm_decode_n_bits(nab->ofs_nbits));
 365         ds_put_cstr(s, ",");
 366     }
 367
 368     ds_put_cstr(s, "slaves:");
 369     for (i = 0; i < ntohs(nab->n_slaves); i++) {
 370         if (i) {
 371             ds_put_cstr(s, ",");
 372         }
 373
 374         ds_put_format(s, "%"PRIu16, bundle_get_slave(nab, i));
 375     }
 376
 377     ds_put_cstr(s, ")");
 378 }