tests/test-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 <math.h>
  21 #include <stdlib.h>
  22
  23 #include "flow.h"
  24 #include "ofpbuf.h"
  25 #include "random.h"
  26
  27 #include "util.h"
  28
  29 #define N_FLOWS  50000
  30 #define MAX_SLAVES 8 /* Maximum supported by this test framework. */
  31
  32 struct slave {
  33     uint16_t slave_id;
  34
  35     bool enabled;
  36     size_t flow_count;
  37 };
  38
  39 struct slave_group {
  40     size_t n_slaves;
  41     struct slave slaves[MAX_SLAVES];
  42 };
  43
  44 static struct slave *
  45 slave_lookup(struct slave_group *sg, uint16_t slave_id)
  46 {
  47     size_t i;
  48
  49     for (i = 0; i < sg->n_slaves; i++) {
  50         if (sg->slaves[i].slave_id == slave_id) {
  51             return &sg->slaves[i];
  52         }
  53     }
  54
  55     return NULL;
  56 }
  57
  58 static bool
  59 slave_enabled_cb(uint16_t slave_id, void *aux)
  60 {
  61     struct slave *slave;
  62
  63     slave = slave_lookup(aux, slave_id);
  64     return slave ? slave->enabled : false;
  65 }
  66
  67 static struct nx_action_bundle *
  68 parse_bundle_actions(char *actions)
  69 {
  70     struct nx_action_bundle *nab;
  71     struct ofpbuf b;
  72
  73     ofpbuf_init(&b, 0);
  74     bundle_parse(&b, actions);
  75     nab = ofpbuf_steal_data(&b);
  76     ofpbuf_uninit(&b);
  77
  78     if (ntohs(nab->n_slaves) > MAX_SLAVES) {
  79         ovs_fatal(0, "At most %u slaves are supported", MAX_SLAVES);
  80     }
  81
  82     return nab;
  83 }
  84
  85 static const char *
  86 mask_str(uint8_t mask, size_t n_bits)
  87 {
  88     static char str[9];
  89     size_t i;
  90
  91     n_bits = MIN(n_bits, 8);
  92     for (i = 0; i < n_bits; i++) {
  93         str[i] = (1 << i) & mask ? '1' : '0';
  94     }
  95     str[i] = '\0';
  96
  97     return str;
  98 }
  99
 100 int
 101 main(int argc, char *argv[])
 102 {
 103     bool ok = true;
 104     struct nx_action_bundle *nab;
 105     struct flow *flows;
 106     size_t i, n_permute, old_n_enabled;
 107     struct slave_group sg;
 108     int old_active;
 109
 110     set_program_name(argv[0]);
 111     random_init();
 112
 113     if (argc != 2) {
 114         ovs_fatal(0, "usage: %s bundle_action", program_name);
 115     }
 116
 117     nab = parse_bundle_actions(argv[1]);
 118
 119     /* Generate 'slaves' array. */
 120     sg.n_slaves = 0;
 121     for (i = 0; i < ntohs(nab->n_slaves); i++) {
 122         uint16_t slave_id = bundle_get_slave(nab, i);
 123
 124         if (slave_lookup(&sg, slave_id)) {
 125             ovs_fatal(0, "Redundant slaves are not supported. ");
 126         }
 127
 128         sg.slaves[sg.n_slaves].slave_id = slave_id;
 129         sg.n_slaves++;
 130     }
 131
 132     /* Generate flows. */
 133     flows = xmalloc(N_FLOWS * sizeof *flows);
 134     for (i = 0; i < N_FLOWS; i++) {
 135         random_bytes(&flows[i], sizeof flows[i]);
 136         flows[i].regs[0] = OFPP_NONE;
 137     }
 138
 139     if (bundle_check(nab, 1024)) {
 140         ovs_fatal(0, "Bundle action fails to check.");
 141     }
 142
 143     /* Cycles through each possible liveness permutation for the given
 144      * n_slaves.  The initial state is equivalent to all slaves down, so we
 145      * skip it by starting at i = 1. We do one extra iteration to cover
 146      * transitioning from the final state back to the initial state. */
 147     old_n_enabled = 0;
 148     old_active = -1;
 149     n_permute = 1 << sg.n_slaves;
 150     for (i = 1; i <= n_permute + 1; i++) {
 151         struct slave *slave;
 152         size_t j, n_enabled, changed;
 153         double disruption, perfect;
 154         uint8_t mask;
 155         int active;
 156
 157         mask = i % n_permute;
 158
 159         /* Gray coding ensures that in each iteration exactly one slave
 160          * changes its liveness.  This makes the expected disruption a bit
 161          * easier to calculate, and is likely similar to how failures will be
 162          * experienced in the wild. */
 163         mask = mask ^ (mask >> 1);
 164
 165         /* Initialize slaves. */
 166         n_enabled = 0;
 167         for (j = 0; j < sg.n_slaves; j++) {
 168             slave = &sg.slaves[j];
 169             slave->flow_count = 0;
 170             slave->enabled = ((1 << j) & mask) != 0;
 171
 172             if (slave->enabled) {
 173                 n_enabled++;
 174             }
 175         }
 176
 177         active = -1;
 178         for (j = 0; j < sg.n_slaves; j++) {
 179             if (sg.slaves[j].enabled) {
 180                 active = j;
 181                 break;
 182             }
 183         }
 184
 185         changed = 0;
 186         for (j = 0; j < N_FLOWS; j++) {
 187             struct flow *flow = &flows[j];
 188             uint16_t old_slave_id;
 189
 190             old_slave_id = flow->regs[0];
 191             flow->regs[0] = bundle_execute(nab, flow, slave_enabled_cb, &sg);
 192
 193             if (flow->regs[0] != OFPP_NONE) {
 194                 slave_lookup(&sg, flow->regs[0])->flow_count++;
 195             }
 196
 197             if (old_slave_id != flow->regs[0]) {
 198                 changed++;
 199             }
 200         }
 201
 202         if (nab->algorithm == htons(NX_BD_ALG_ACTIVE_BACKUP)) {
 203             perfect = active == old_active ? 0.0 : 1.0;
 204         } else {
 205             if (old_n_enabled || n_enabled) {
 206                 perfect = 1.0 / MAX(old_n_enabled, n_enabled);
 207             } else {
 208                 /* This will happen when 'sg.n_slaves' is 0. */
 209                 perfect = 0;
 210             }
 211         }
 212
 213         disruption = changed / (double)N_FLOWS;
 214         printf("%s: disruption=%.2f (perfect=%.2f)",
 215                mask_str(mask, sg.n_slaves), disruption, perfect);
 216
 217         for (j = 0 ; j < sg.n_slaves; j++) {
 218             struct slave *slave = &sg.slaves[j];
 219             double flow_percent;
 220
 221             flow_percent = slave->flow_count / (double)N_FLOWS;
 222             printf( " %.2f", flow_percent);
 223
 224             if (slave->enabled) {
 225                 double perfect_fp;
 226
 227                 if (nab->algorithm == htons(NX_BD_ALG_ACTIVE_BACKUP)) {
 228                     perfect_fp = j == active ? 1.0 : 0.0;
 229                 } else {
 230                     perfect_fp = 1.0 / n_enabled;
 231                 }
 232
 233                 if (fabs(flow_percent - perfect_fp) >= .01) {
 234                     fprintf(stderr, "%s: slave %d: flow_percentage=%.5f for"
 235                             " differs from perfect=%.5f by more than .01\n",
 236                             mask_str(mask, sg.n_slaves), slave->slave_id,
 237                             flow_percent, perfect_fp);
 238                     ok = false;
 239                 }
 240             } else if (slave->flow_count) {
 241                 fprintf(stderr, "%s: slave %d: disabled slave received"
 242                         " flows.\n", mask_str(mask, sg.n_slaves),
 243                         slave->slave_id);
 244                 ok = false;
 245             }
 246         }
 247         printf("\n");
 248
 249         if (fabs(disruption - perfect) >= .01) {
 250             fprintf(stderr, "%s: disruption=%.5f differs from perfect=%.5f by"
 251                     " more than .01\n", mask_str(mask, sg.n_slaves),
 252                     disruption, perfect);
 253             ok = false;
 254         }
 255
 256         old_active = active;
 257         old_n_enabled = n_enabled;
 258     }
 259
 260     free(nab);
 261     free(flows);
 262     return ok ? 0 : 1;
 263 }