lib/bundle.c

   1 /* Copyright (c) 2011 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-util.h"
  28 #include "openflow/nicira-ext.h"
  29 #include "vlog.h"
  30
  31 #define BUNDLE_MAX_SLAVES 2048
  32
  33 VLOG_DEFINE_THIS_MODULE(bundle);
  34
  35 static uint16_t
  36 execute_ab(const struct nx_action_bundle *nab,
  37            bool (*slave_enabled)(uint16_t ofp_port, void *aux), void *aux)
  38 {
  39     size_t i;
  40
  41     for (i = 0; i < ntohs(nab->n_slaves); i++) {
  42         uint16_t slave = bundle_get_slave(nab, i);
  43
  44         if (slave_enabled(slave, aux)) {
  45             return slave;
  46         }
  47     }
  48
  49     return OFPP_NONE;
  50 }
  51
  52 static uint16_t
  53 execute_hrw(const struct nx_action_bundle *nab, const struct flow *flow,
  54             bool (*slave_enabled)(uint16_t ofp_port, void *aux), void *aux)
  55 {
  56     uint32_t flow_hash, best_hash;
  57     int best, i;
  58
  59     flow_hash = flow_hash_fields(flow, ntohs(nab->fields), ntohs(nab->basis));
  60     best = -1;
  61     best_hash = 0;
  62
  63     for (i = 0; i < ntohs(nab->n_slaves); i++) {
  64         if (slave_enabled(bundle_get_slave(nab, i), aux)) {
  65             uint32_t hash = hash_2words(i, flow_hash);
  66
  67             if (best < 0 || hash > best_hash) {
  68                 best_hash = hash;
  69                 best = i;
  70             }
  71         }
  72     }
  73
  74     return best >= 0 ? bundle_get_slave(nab, best) : OFPP_NONE;
  75 }
  76
  77 /* Executes 'nab' on 'flow'.  Uses 'slave_enabled' to determine if the slave
  78  * designated by 'ofp_port' is up.  Returns the chosen slave, or OFPP_NONE if
  79  * none of the slaves are acceptable. */
  80 uint16_t
  81 bundle_execute(const struct nx_action_bundle *nab, const struct flow *flow,
  82                bool (*slave_enabled)(uint16_t ofp_port, void *aux), void *aux)
  83 {
  84     switch (ntohs(nab->algorithm)) {
  85     case NX_BD_ALG_HRW: return execute_hrw(nab, flow, slave_enabled, aux);
  86     case NX_BD_ALG_ACTIVE_BACKUP: return execute_ab(nab, slave_enabled, aux);
  87     default: NOT_REACHED();
  88     }
  89 }
  90
  91 void
  92 bundle_execute_load(const struct nx_action_bundle *nab, struct flow *flow,
  93                     bool (*slave_enabled)(uint16_t ofp_port, void *aux),
  94                     void *aux)
  95 {
  96     nxm_reg_load(nab->dst, nab->ofs_nbits,
  97                  bundle_execute(nab, flow, slave_enabled, aux), flow);
  98 }
  99
 100 /* Checks that 'nab' specifies a bundle action which is supported by this
 101  * bundle module.  Uses the 'max_ports' parameter to validate each port using
 102  * ofputil_check_output_port().  Returns 0 if 'nab' is supported, otherwise an
 103  * OpenFlow error code (as returned by ofp_mkerr()). */
 104 int
 105 bundle_check(const struct nx_action_bundle *nab, int max_ports,
 106              const struct flow *flow)
 107 {
 108     static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
 109     uint16_t n_slaves, fields, algorithm, subtype;
 110     uint32_t slave_type;
 111     size_t slaves_size, i;
 112     int error;
 113
 114     subtype = ntohs(nab->subtype);
 115     n_slaves = ntohs(nab->n_slaves);
 116     fields = ntohs(nab->fields);
 117     algorithm = ntohs(nab->algorithm);
 118     slave_type = ntohl(nab->slave_type);
 119     slaves_size = ntohs(nab->len) - sizeof *nab;
 120
 121     error = ofp_mkerr(OFPET_BAD_ACTION, OFPBAC_BAD_ARGUMENT);
 122     if (!flow_hash_fields_valid(fields)) {
 123         VLOG_WARN_RL(&rl, "unsupported fields %"PRIu16, fields);
 124     } else if (n_slaves > BUNDLE_MAX_SLAVES) {
 125         VLOG_WARN_RL(&rl, "too may slaves");
 126     } else if (algorithm != NX_BD_ALG_HRW
 127                && algorithm != NX_BD_ALG_ACTIVE_BACKUP) {
 128         VLOG_WARN_RL(&rl, "unsupported algorithm %"PRIu16, algorithm);
 129     } else if (slave_type != NXM_OF_IN_PORT) {
 130         VLOG_WARN_RL(&rl, "unsupported slave type %"PRIu16, slave_type);
 131     } else {
 132         error = 0;
 133     }
 134
 135     for (i = 0; i < sizeof(nab->zero); i++) {
 136         if (nab->zero[i]) {
 137             VLOG_WARN_RL(&rl, "reserved field is nonzero");
 138             error = ofp_mkerr(OFPET_BAD_ACTION, OFPBAC_BAD_ARGUMENT);
 139         }
 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 = ofp_mkerr(OFPET_BAD_ACTION, OFPBAC_BAD_ARGUMENT);
 145     }
 146
 147     if (subtype == NXAST_BUNDLE_LOAD) {
 148         int ofs = nxm_decode_ofs(nab->ofs_nbits);
 149         int n_bits = nxm_decode_n_bits(nab->ofs_nbits);
 150
 151         if (n_bits < 16) {
 152             VLOG_WARN_RL(&rl, "bundle_load action requires at least 16 bit "
 153                          "destination.");
 154             error = ofp_mkerr(OFPET_BAD_ACTION, OFPBAC_BAD_ARGUMENT);
 155         } else {
 156             error = nxm_dst_check(nab->dst, ofs, n_bits, flow) || error;
 157         }
 158     }
 159
 160     if (slaves_size < n_slaves * sizeof(ovs_be16)) {
 161         VLOG_WARN_RL(&rl, "Nicira action %"PRIu16" only has %zu bytes "
 162                      "allocated for slaves.  %zu bytes are required for "
 163                      "%"PRIu16" slaves.", subtype, slaves_size,
 164                      n_slaves * sizeof(ovs_be16), n_slaves);
 165         error = ofp_mkerr(OFPET_BAD_ACTION, OFPBAC_BAD_LEN);
 166     }
 167
 168     for (i = 0; i < n_slaves; i++) {
 169         uint16_t ofp_port = bundle_get_slave(nab, i);
 170         int ofputil_error = ofputil_check_output_port(ofp_port, max_ports);
 171
 172         if (ofputil_error) {
 173             VLOG_WARN_RL(&rl, "invalid slave %"PRIu16, ofp_port);
 174             error = ofputil_error;
 175         }
 176
 177         /* Controller slaves are unsupported due to the lack of a max_len
 178          * argument. This may or may not change in the future.  There doesn't
 179          * seem to be a real-world use-case for supporting it. */
 180         if (ofp_port == OFPP_CONTROLLER) {
 181             VLOG_WARN_RL(&rl, "unsupported controller slave");
 182             error = ofp_mkerr(OFPET_BAD_ACTION, OFPBAC_BAD_OUT_PORT);
 183         }
 184     }
 185
 186     return error;
 187 }
 188
 189 /* Helper for bundle_parse and bundle_parse_load. */
 190 static void
 191 bundle_parse__(struct ofpbuf *b, const char *s, char **save_ptr,
 192                const char *fields, const char *basis, const char *algorithm,
 193                const char *slave_type, const char *dst,
 194                const char *slave_delim)
 195 {
 196     struct nx_action_bundle *nab;
 197     uint16_t n_slaves;
 198
 199     if (!slave_delim) {
 200         ovs_fatal(0, "%s: not enough arguments to bundle action", s);
 201     }
 202
 203     if (strcasecmp(slave_delim, "slaves")) {
 204         ovs_fatal(0, "%s: missing slave delimiter, expected `slaves' got `%s'",
 205                    s, slave_delim);
 206     }
 207
 208     b->l2 = ofpbuf_put_zeros(b, sizeof *nab);
 209
 210     n_slaves = 0;
 211     for (;;) {
 212         ovs_be16 slave_be;
 213         char *slave;
 214
 215         slave = strtok_r(NULL, ", ", save_ptr);
 216         if (!slave || n_slaves >= BUNDLE_MAX_SLAVES) {
 217             break;
 218         }
 219
 220         slave_be = htons(atoi(slave));
 221         ofpbuf_put(b, &slave_be, sizeof slave_be);
 222
 223         n_slaves++;
 224     }
 225
 226     /* Slaves array must be multiple of 8 bytes long. */
 227     if (b->size % 8) {
 228         ofpbuf_put_zeros(b, 8 - (b->size % 8));
 229     }
 230
 231     nab = b->l2;
 232     nab->type = htons(OFPAT_VENDOR);
 233     nab->len = htons(b->size - ((char *) b->l2 - (char *) b->data));
 234     nab->vendor = htonl(NX_VENDOR_ID);
 235     nab->subtype = htons(dst ? NXAST_BUNDLE_LOAD: NXAST_BUNDLE);
 236     nab->n_slaves = htons(n_slaves);
 237     nab->basis = htons(atoi(basis));
 238
 239     if (!strcasecmp(fields, "eth_src")) {
 240         nab->fields = htons(NX_HASH_FIELDS_ETH_SRC);
 241     } else if (!strcasecmp(fields, "symmetric_l4")) {
 242         nab->fields = htons(NX_HASH_FIELDS_SYMMETRIC_L4);
 243     } else {
 244         ovs_fatal(0, "%s: unknown fields `%s'", s, fields);
 245     }
 246
 247     if (!strcasecmp(algorithm, "active_backup")) {
 248         nab->algorithm = htons(NX_BD_ALG_ACTIVE_BACKUP);
 249     } else if (!strcasecmp(algorithm, "hrw")) {
 250         nab->algorithm = htons(NX_BD_ALG_HRW);
 251     } else {
 252         ovs_fatal(0, "%s: unknown algorithm `%s'", s, algorithm);
 253     }
 254
 255     if (!strcasecmp(slave_type, "ofport")) {
 256         nab->slave_type = htonl(NXM_OF_IN_PORT);
 257     } else {
 258         ovs_fatal(0, "%s: unknown slave_type `%s'", s, slave_type);
 259     }
 260
 261     if (dst) {
 262         uint32_t reg;
 263         int ofs, n_bits;
 264
 265         nxm_parse_field_bits(dst, &reg, &ofs, &n_bits);
 266
 267         nab->dst = htonl(reg);
 268         nab->ofs_nbits = nxm_encode_ofs_nbits(ofs, n_bits);
 269     }
 270
 271     b->l2 = NULL;
 272 }
 273
 274 /* Converts a bundle action string contained in 's' to an nx_action_bundle and
 275  * stores it in 'b'.  Sets 'b''s l2 pointer to NULL. */
 276 void
 277 bundle_parse(struct ofpbuf *b, const char *s)
 278 {
 279     char *fields, *basis, *algorithm, *slave_type, *slave_delim;
 280     char *tokstr, *save_ptr;
 281
 282     save_ptr = NULL;
 283     tokstr = xstrdup(s);
 284     fields = strtok_r(tokstr, ", ", &save_ptr);
 285     basis = strtok_r(NULL, ", ", &save_ptr);
 286     algorithm = strtok_r(NULL, ", ", &save_ptr);
 287     slave_type = strtok_r(NULL, ", ", &save_ptr);
 288     slave_delim = strtok_r(NULL, ": ", &save_ptr);
 289
 290     bundle_parse__(b, s, &save_ptr, fields, basis, algorithm, slave_type, NULL,
 291                    slave_delim);
 292     free(tokstr);
 293 }
 294
 295 /* Converts a bundle_load action string contained in 's' to an nx_action_bundle
 296  * and stores it in 'b'.  Sets 'b''s l2 pointer to NULL. */
 297 void
 298 bundle_parse_load(struct ofpbuf *b, const char *s)
 299 {
 300     char *fields, *basis, *algorithm, *slave_type, *dst, *slave_delim;
 301     char *tokstr, *save_ptr;
 302
 303     save_ptr = NULL;
 304     tokstr = xstrdup(s);
 305     fields = strtok_r(tokstr, ", ", &save_ptr);
 306     basis = strtok_r(NULL, ", ", &save_ptr);
 307     algorithm = strtok_r(NULL, ", ", &save_ptr);
 308     slave_type = strtok_r(NULL, ", ", &save_ptr);
 309     dst = strtok_r(NULL, ", ", &save_ptr);
 310     slave_delim = strtok_r(NULL, ": ", &save_ptr);
 311
 312     bundle_parse__(b, s, &save_ptr, fields, basis, algorithm, slave_type, dst,
 313                    slave_delim);
 314
 315     free(tokstr);
 316 }
 317
 318 /* Appends a human-readable representation of 'nab' to 's'. */
 319 void
 320 bundle_format(const struct nx_action_bundle *nab, struct ds *s)
 321 {
 322     const char *action, *fields, *algorithm, *slave_type;
 323     size_t i;
 324
 325     fields = flow_hash_fields_to_str(ntohs(nab->fields));
 326
 327     switch (ntohs(nab->algorithm)) {
 328     case NX_BD_ALG_HRW:
 329         algorithm = "hrw";
 330         break;
 331     case NX_BD_ALG_ACTIVE_BACKUP:
 332         algorithm = "active_backup";
 333         break;
 334     default:
 335         algorithm = "<unknown>";
 336     }
 337
 338     switch (ntohl(nab->slave_type)) {
 339     case NXM_OF_IN_PORT:
 340         slave_type = "ofport";
 341         break;
 342     default:
 343         slave_type = "<unknown>";
 344     }
 345
 346     switch (ntohs(nab->subtype)) {
 347     case NXAST_BUNDLE:
 348         action = "bundle";
 349         break;
 350     case NXAST_BUNDLE_LOAD:
 351         action = "bundle_load";
 352         break;
 353     default:
 354         NOT_REACHED();
 355     }
 356
 357     ds_put_format(s, "%s(%s,%"PRIu16",%s,%s,", action, fields,
 358                   ntohs(nab->basis), algorithm, slave_type);
 359
 360     if (nab->subtype == htons(NXAST_BUNDLE_LOAD)) {
 361         nxm_format_field_bits(s, ntohl(nab->dst),
 362                               nxm_decode_ofs(nab->ofs_nbits),
 363                               nxm_decode_n_bits(nab->ofs_nbits));
 364         ds_put_cstr(s, ",");
 365     }
 366
 367     ds_put_cstr(s, "slaves:");
 368     for (i = 0; i < ntohs(nab->n_slaves); i++) {
 369         if (i) {
 370             ds_put_cstr(s, ",");
 371         }
 372
 373         ds_put_format(s, "%"PRIu16, bundle_get_slave(nab, i));
 374     }
 375
 376     ds_put_cstr(s, ")");
 377 }