lib/bundle.c

   1 /* Copyright (c) 2011, 2012, 2013, 2014 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 "openvswitch/vlog.h"
  33
  34 VLOG_DEFINE_THIS_MODULE(bundle);
  35
  36 static ofp_port_t
  37 execute_ab(const struct ofpact_bundle *bundle,
  38            bool (*slave_enabled)(ofp_port_t ofp_port, void *aux), void *aux)
  39 {
  40     size_t i;
  41
  42     for (i = 0; i < bundle->n_slaves; i++) {
  43         ofp_port_t slave = bundle->slaves[i];
  44         if (slave_enabled(slave, aux)) {
  45             return slave;
  46         }
  47     }
  48
  49     return OFPP_NONE;
  50 }
  51
  52 static ofp_port_t
  53 execute_hrw(const struct ofpact_bundle *bundle,
  54             const struct flow *flow, struct flow_wildcards *wc,
  55             bool (*slave_enabled)(ofp_port_t ofp_port, void *aux), void *aux)
  56 {
  57     uint32_t flow_hash, best_hash;
  58     int best, i;
  59
  60     if (bundle->n_slaves > 1) {
  61         flow_mask_hash_fields(flow, wc, bundle->fields);
  62     }
  63
  64     flow_hash = flow_hash_fields(flow, bundle->fields, bundle->basis);
  65     best = -1;
  66     best_hash = 0;
  67
  68     for (i = 0; i < bundle->n_slaves; i++) {
  69         if (slave_enabled(bundle->slaves[i], aux)) {
  70             uint32_t hash = hash_2words(i, flow_hash);
  71
  72             if (best < 0 || hash > best_hash) {
  73                 best_hash = hash;
  74                 best = i;
  75             }
  76         }
  77     }
  78
  79     return best >= 0 ? bundle->slaves[best] : OFPP_NONE;
  80 }
  81
  82 /* Executes 'bundle' on 'flow'.  Sets fields in 'wc' that were used to
  83  * calculate the result.  Uses 'slave_enabled' to determine if the slave
  84  * designated by 'ofp_port' is up.  Returns the chosen slave, or
  85  * OFPP_NONE if none of the slaves are acceptable. */
  86 ofp_port_t
  87 bundle_execute(const struct ofpact_bundle *bundle,
  88                const struct flow *flow, struct flow_wildcards *wc,
  89                bool (*slave_enabled)(ofp_port_t ofp_port, void *aux),
  90                void *aux)
  91 {
  92     switch (bundle->algorithm) {
  93     case NX_BD_ALG_HRW:
  94         return execute_hrw(bundle, flow, wc, slave_enabled, aux);
  95
  96     case NX_BD_ALG_ACTIVE_BACKUP:
  97         return execute_ab(bundle, slave_enabled, aux);
  98
  99     default:
 100         OVS_NOT_REACHED();
 101     }
 102 }
 103
 104 enum ofperr
 105 bundle_check(const struct ofpact_bundle *bundle, ofp_port_t max_ports,
 106              const struct flow *flow)
 107 {
 108     static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
 109     size_t i;
 110
 111     if (bundle->dst.field) {
 112         enum ofperr error = mf_check_dst(&bundle->dst, flow);
 113         if (error) {
 114             return error;
 115         }
 116     }
 117
 118     for (i = 0; i < bundle->n_slaves; i++) {
 119         ofp_port_t ofp_port = bundle->slaves[i];
 120         enum ofperr error;
 121
 122         error = ofpact_check_output_port(ofp_port, max_ports);
 123         if (error) {
 124             VLOG_WARN_RL(&rl, "invalid slave %"PRIu16, ofp_port);
 125             return error;
 126         }
 127
 128         /* Controller slaves are unsupported due to the lack of a max_len
 129          * argument. This may or may not change in the future.  There doesn't
 130          * seem to be a real-world use-case for supporting it. */
 131         if (ofp_port == OFPP_CONTROLLER) {
 132             VLOG_WARN_RL(&rl, "unsupported controller slave");
 133             return OFPERR_OFPBAC_BAD_OUT_PORT;
 134         }
 135     }
 136
 137     return 0;
 138 }
 139
 140
 141 /* Helper for bundle_parse and bundle_parse_load.
 142  *
 143  * Returns NULL if successful, otherwise a malloc()'d string describing the
 144  * error.  The caller is responsible for freeing the returned string.*/
 145 static char * OVS_WARN_UNUSED_RESULT
 146 bundle_parse__(const char *s, char **save_ptr,
 147                const char *fields, const char *basis, const char *algorithm,
 148                const char *slave_type, const char *dst,
 149                const char *slave_delim, struct ofpbuf *ofpacts)
 150 {
 151     struct ofpact_bundle *bundle;
 152
 153     if (!slave_delim) {
 154         return xasprintf("%s: not enough arguments to bundle action", s);
 155     }
 156
 157     if (strcasecmp(slave_delim, "slaves")) {
 158         return xasprintf("%s: missing slave delimiter, expected `slaves' "
 159                          "got `%s'", s, slave_delim);
 160     }
 161
 162     bundle = ofpact_put_BUNDLE(ofpacts);
 163
 164     for (;;) {
 165         ofp_port_t slave_port;
 166         char *slave;
 167
 168         slave = strtok_r(NULL, ", []", save_ptr);
 169         if (!slave || bundle->n_slaves >= BUNDLE_MAX_SLAVES) {
 170             break;
 171         }
 172
 173         if (!ofputil_port_from_string(slave, &slave_port)) {
 174             return xasprintf("%s: bad port number", slave);
 175         }
 176         ofpbuf_put(ofpacts, &slave_port, sizeof slave_port);
 177
 178         bundle = ofpacts->header;
 179         bundle->n_slaves++;
 180     }
 181     ofpact_update_len(ofpacts, &bundle->ofpact);
 182
 183     bundle->basis = atoi(basis);
 184
 185     if (!strcasecmp(fields, "eth_src")) {
 186         bundle->fields = NX_HASH_FIELDS_ETH_SRC;
 187     } else if (!strcasecmp(fields, "symmetric_l4")) {
 188         bundle->fields = NX_HASH_FIELDS_SYMMETRIC_L4;
 189     } else {
 190         return xasprintf("%s: unknown fields `%s'", s, fields);
 191     }
 192
 193     if (!strcasecmp(algorithm, "active_backup")) {
 194         bundle->algorithm = NX_BD_ALG_ACTIVE_BACKUP;
 195     } else if (!strcasecmp(algorithm, "hrw")) {
 196         bundle->algorithm = NX_BD_ALG_HRW;
 197     } else {
 198         return xasprintf("%s: unknown algorithm `%s'", s, algorithm);
 199     }
 200
 201     if (strcasecmp(slave_type, "ofport")) {
 202         return xasprintf("%s: unknown slave_type `%s'", s, slave_type);
 203     }
 204
 205     if (dst) {
 206         char *error = mf_parse_subfield(&bundle->dst, dst);
 207         if (error) {
 208             return error;
 209         }
 210
 211         if (!mf_nxm_header(bundle->dst.field->id)) {
 212             return xasprintf("%s: experimenter OXM field '%s' not supported",
 213                              s, dst);
 214         }
 215     }
 216
 217     return NULL;
 218 }
 219
 220 /* Converts a bundle action string contained in 's' to an nx_action_bundle and
 221  * stores it in 'b'.  Sets 'b''s l2 pointer to NULL.
 222  *
 223  * Returns NULL if successful, otherwise a malloc()'d string describing the
 224  * error.  The caller is responsible for freeing the returned string. */
 225 char * OVS_WARN_UNUSED_RESULT
 226 bundle_parse(const char *s, struct ofpbuf *ofpacts)
 227 {
 228     char *fields, *basis, *algorithm, *slave_type, *slave_delim;
 229     char *tokstr, *save_ptr;
 230     char *error;
 231
 232     save_ptr = NULL;
 233     tokstr = xstrdup(s);
 234     fields = strtok_r(tokstr, ", ", &save_ptr);
 235     basis = strtok_r(NULL, ", ", &save_ptr);
 236     algorithm = strtok_r(NULL, ", ", &save_ptr);
 237     slave_type = strtok_r(NULL, ", ", &save_ptr);
 238     slave_delim = strtok_r(NULL, ": ", &save_ptr);
 239
 240     error = bundle_parse__(s, &save_ptr, fields, basis, algorithm, slave_type,
 241                            NULL, slave_delim, ofpacts);
 242     free(tokstr);
 243
 244     return error;
 245 }
 246
 247 /* Converts a bundle_load action string contained in 's' to an nx_action_bundle
 248  * and stores it in 'b'.  Sets 'b''s l2 pointer to NULL.
 249  *
 250  * Returns NULL if successful, otherwise a malloc()'d string describing the
 251  * error.  The caller is responsible for freeing the returned string.*/
 252 char * OVS_WARN_UNUSED_RESULT
 253 bundle_parse_load(const char *s, struct ofpbuf *ofpacts)
 254 {
 255     char *fields, *basis, *algorithm, *slave_type, *dst, *slave_delim;
 256     char *tokstr, *save_ptr;
 257     char *error;
 258
 259     save_ptr = NULL;
 260     tokstr = xstrdup(s);
 261     fields = strtok_r(tokstr, ", ", &save_ptr);
 262     basis = strtok_r(NULL, ", ", &save_ptr);
 263     algorithm = strtok_r(NULL, ", ", &save_ptr);
 264     slave_type = strtok_r(NULL, ", ", &save_ptr);
 265     dst = strtok_r(NULL, ", ", &save_ptr);
 266     slave_delim = strtok_r(NULL, ": ", &save_ptr);
 267
 268     error = bundle_parse__(s, &save_ptr, fields, basis, algorithm, slave_type,
 269                            dst, slave_delim, ofpacts);
 270
 271     free(tokstr);
 272
 273     return error;
 274 }
 275
 276 /* Appends a human-readable representation of 'nab' to 's'. */
 277 void
 278 bundle_format(const struct ofpact_bundle *bundle, struct ds *s)
 279 {
 280     const char *action, *fields, *algorithm;
 281     size_t i;
 282
 283     fields = flow_hash_fields_to_str(bundle->fields);
 284
 285     switch (bundle->algorithm) {
 286     case NX_BD_ALG_HRW:
 287         algorithm = "hrw";
 288         break;
 289     case NX_BD_ALG_ACTIVE_BACKUP:
 290         algorithm = "active_backup";
 291         break;
 292     default:
 293         algorithm = "<unknown>";
 294     }
 295
 296     action = bundle->dst.field ? "bundle_load" : "bundle";
 297
 298     ds_put_format(s, "%s(%s,%"PRIu16",%s,%s,", action, fields,
 299                   bundle->basis, algorithm, "ofport");
 300
 301     if (bundle->dst.field) {
 302         mf_format_subfield(&bundle->dst, s);
 303         ds_put_cstr(s, ",");
 304     }
 305
 306     ds_put_cstr(s, "slaves:");
 307     for (i = 0; i < bundle->n_slaves; i++) {
 308         if (i) {
 309             ds_put_cstr(s, ",");
 310         }
 311
 312         ofputil_format_port(bundle->slaves[i], s);
 313     }
 314
 315     ds_put_cstr(s, ")");
 316 }