lib/ofp-parse.c

   1 /*
   2  * Copyright (c) 2010, 2011, 2012, 2013, 2014, 2015 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include <config.h>
  18
  19 #include "ofp-parse.h"
  20
  21 #include <ctype.h>
  22 #include <errno.h>
  23 #include <stdlib.h>
  24
  25 #include "byte-order.h"
  26 #include "dynamic-string.h"
  27 #include "learn.h"
  28 #include "meta-flow.h"
  29 #include "multipath.h"
  30 #include "netdev.h"
  31 #include "nx-match.h"
  32 #include "ofp-actions.h"
  33 #include "ofp-util.h"
  34 #include "ofpbuf.h"
  35 #include "openflow/openflow.h"
  36 #include "ovs-thread.h"
  37 #include "packets.h"
  38 #include "simap.h"
  39 #include "socket-util.h"
  40 #include "openvswitch/vconn.h"
  41
  42 /* Parses 'str' as an 8-bit unsigned integer into '*valuep'.
  43  *
  44  * 'name' describes the value parsed in an error message, if any.
  45  *
  46  * Returns NULL if successful, otherwise a malloc()'d string describing the
  47  * error.  The caller is responsible for freeing the returned string. */
  48 char * OVS_WARN_UNUSED_RESULT
  49 str_to_u8(const char *str, const char *name, uint8_t *valuep)
  50 {
  51     int value;
  52
  53     if (!str_to_int(str, 0, &value) || value < 0 || value > 255) {
  54         return xasprintf("invalid %s \"%s\"", name, str);
  55     }
  56     *valuep = value;
  57     return NULL;
  58 }
  59
  60 /* Parses 'str' as a 16-bit unsigned integer into '*valuep'.
  61  *
  62  * 'name' describes the value parsed in an error message, if any.
  63  *
  64  * Returns NULL if successful, otherwise a malloc()'d string describing the
  65  * error.  The caller is responsible for freeing the returned string. */
  66 char * OVS_WARN_UNUSED_RESULT
  67 str_to_u16(const char *str, const char *name, uint16_t *valuep)
  68 {
  69     int value;
  70
  71     if (!str_to_int(str, 0, &value) || value < 0 || value > 65535) {
  72         return xasprintf("invalid %s \"%s\"", name, str);
  73     }
  74     *valuep = value;
  75     return NULL;
  76 }
  77
  78 /* Parses 'str' as a 32-bit unsigned integer into '*valuep'.
  79  *
  80  * Returns NULL if successful, otherwise a malloc()'d string describing the
  81  * error.  The caller is responsible for freeing the returned string. */
  82 char * OVS_WARN_UNUSED_RESULT
  83 str_to_u32(const char *str, uint32_t *valuep)
  84 {
  85     char *tail;
  86     uint32_t value;
  87
  88     if (!str[0]) {
  89         return xstrdup("missing required numeric argument");
  90     }
  91
  92     errno = 0;
  93     value = strtoul(str, &tail, 0);
  94     if (errno == EINVAL || errno == ERANGE || *tail) {
  95         return xasprintf("invalid numeric format %s", str);
  96     }
  97     *valuep = value;
  98     return NULL;
  99 }
 100
 101 /* Parses 'str' as an 64-bit unsigned integer into '*valuep'.
 102  *
 103  * Returns NULL if successful, otherwise a malloc()'d string describing the
 104  * error.  The caller is responsible for freeing the returned string. */
 105 char * OVS_WARN_UNUSED_RESULT
 106 str_to_u64(const char *str, uint64_t *valuep)
 107 {
 108     char *tail;
 109     uint64_t value;
 110
 111     if (!str[0]) {
 112         return xstrdup("missing required numeric argument");
 113     }
 114
 115     errno = 0;
 116     value = strtoull(str, &tail, 0);
 117     if (errno == EINVAL || errno == ERANGE || *tail) {
 118         return xasprintf("invalid numeric format %s", str);
 119     }
 120     *valuep = value;
 121     return NULL;
 122 }
 123
 124 /* Parses 'str' as an 64-bit unsigned integer in network byte order into
 125  * '*valuep'.
 126  *
 127  * Returns NULL if successful, otherwise a malloc()'d string describing the
 128  * error.  The caller is responsible for freeing the returned string. */
 129 char * OVS_WARN_UNUSED_RESULT
 130 str_to_be64(const char *str, ovs_be64 *valuep)
 131 {
 132     uint64_t value = 0;
 133     char *error;
 134
 135     error = str_to_u64(str, &value);
 136     if (!error) {
 137         *valuep = htonll(value);
 138     }
 139     return error;
 140 }
 141
 142 /* Parses 'str' as an Ethernet address into 'mac'.
 143  *
 144  * Returns NULL if successful, otherwise a malloc()'d string describing the
 145  * error.  The caller is responsible for freeing the returned string. */
 146 char * OVS_WARN_UNUSED_RESULT
 147 str_to_mac(const char *str, uint8_t mac[ETH_ADDR_LEN])
 148 {
 149     if (!ovs_scan(str, ETH_ADDR_SCAN_FMT, ETH_ADDR_SCAN_ARGS(mac))) {
 150         return xasprintf("invalid mac address %s", str);
 151     }
 152     return NULL;
 153 }
 154
 155 /* Parses 'str' as an IP address into '*ip'.
 156  *
 157  * Returns NULL if successful, otherwise a malloc()'d string describing the
 158  * error.  The caller is responsible for freeing the returned string. */
 159 char * OVS_WARN_UNUSED_RESULT
 160 str_to_ip(const char *str, ovs_be32 *ip)
 161 {
 162     struct in_addr in_addr;
 163
 164     if (lookup_ip(str, &in_addr)) {
 165         return xasprintf("%s: could not convert to IP address", str);
 166     }
 167     *ip = in_addr.s_addr;
 168     return NULL;
 169 }
 170
 171 struct protocol {
 172     const char *name;
 173     uint16_t dl_type;
 174     uint8_t nw_proto;
 175 };
 176
 177 static bool
 178 parse_protocol(const char *name, const struct protocol **p_out)
 179 {
 180     static const struct protocol protocols[] = {
 181         { "ip", ETH_TYPE_IP, 0 },
 182         { "arp", ETH_TYPE_ARP, 0 },
 183         { "icmp", ETH_TYPE_IP, IPPROTO_ICMP },
 184         { "tcp", ETH_TYPE_IP, IPPROTO_TCP },
 185         { "udp", ETH_TYPE_IP, IPPROTO_UDP },
 186         { "sctp", ETH_TYPE_IP, IPPROTO_SCTP },
 187         { "ipv6", ETH_TYPE_IPV6, 0 },
 188         { "ip6", ETH_TYPE_IPV6, 0 },
 189         { "icmp6", ETH_TYPE_IPV6, IPPROTO_ICMPV6 },
 190         { "tcp6", ETH_TYPE_IPV6, IPPROTO_TCP },
 191         { "udp6", ETH_TYPE_IPV6, IPPROTO_UDP },
 192         { "sctp6", ETH_TYPE_IPV6, IPPROTO_SCTP },
 193         { "rarp", ETH_TYPE_RARP, 0},
 194         { "mpls", ETH_TYPE_MPLS, 0 },
 195         { "mplsm", ETH_TYPE_MPLS_MCAST, 0 },
 196     };
 197     const struct protocol *p;
 198
 199     for (p = protocols; p < &protocols[ARRAY_SIZE(protocols)]; p++) {
 200         if (!strcmp(p->name, name)) {
 201             *p_out = p;
 202             return true;
 203         }
 204     }
 205     *p_out = NULL;
 206     return false;
 207 }
 208
 209 /* Parses 's' as the (possibly masked) value of field 'mf', and updates
 210  * 'match' appropriately.  Restricts the set of usable protocols to ones
 211  * supporting the parsed field.
 212  *
 213  * Returns NULL if successful, otherwise a malloc()'d string describing the
 214  * error.  The caller is responsible for freeing the returned string. */
 215 static char * OVS_WARN_UNUSED_RESULT
 216 parse_field(const struct mf_field *mf, const char *s, struct match *match,
 217             enum ofputil_protocol *usable_protocols)
 218 {
 219     union mf_value value, mask;
 220     char *error;
 221
 222     error = mf_parse(mf, s, &value, &mask);
 223     if (!error) {
 224         *usable_protocols &= mf_set(mf, &value, &mask, match);
 225     }
 226     return error;
 227 }
 228
 229 static char *
 230 extract_actions(char *s)
 231 {
 232     s = strstr(s, "action");
 233     if (s) {
 234         *s = '\0';
 235         s = strchr(s + 1, '=');
 236         return s ? s + 1 : NULL;
 237     } else {
 238         return NULL;
 239     }
 240 }
 241
 242
 243 static char * OVS_WARN_UNUSED_RESULT
 244 parse_ofp_str__(struct ofputil_flow_mod *fm, int command, char *string,
 245                 enum ofputil_protocol *usable_protocols)
 246 {
 247     enum {
 248         F_OUT_PORT = 1 << 0,
 249         F_ACTIONS = 1 << 1,
 250         F_IMPORTANCE = 1 << 2,
 251         F_TIMEOUT = 1 << 3,
 252         F_PRIORITY = 1 << 4,
 253         F_FLAGS = 1 << 5,
 254     } fields;
 255     char *save_ptr = NULL;
 256     char *act_str = NULL;
 257     char *name;
 258
 259     *usable_protocols = OFPUTIL_P_ANY;
 260
 261     switch (command) {
 262     case -1:
 263         fields = F_OUT_PORT;
 264         break;
 265
 266     case OFPFC_ADD:
 267         fields = F_ACTIONS | F_TIMEOUT | F_PRIORITY | F_FLAGS | F_IMPORTANCE;
 268         break;
 269
 270     case OFPFC_DELETE:
 271         fields = F_OUT_PORT;
 272         break;
 273
 274     case OFPFC_DELETE_STRICT:
 275         fields = F_OUT_PORT | F_PRIORITY;
 276         break;
 277
 278     case OFPFC_MODIFY:
 279         fields = F_ACTIONS | F_TIMEOUT | F_PRIORITY | F_FLAGS;
 280         break;
 281
 282     case OFPFC_MODIFY_STRICT:
 283         fields = F_ACTIONS | F_TIMEOUT | F_PRIORITY | F_FLAGS;
 284         break;
 285
 286     default:
 287         OVS_NOT_REACHED();
 288     }
 289
 290     match_init_catchall(&fm->match);
 291     fm->priority = OFP_DEFAULT_PRIORITY;
 292     fm->cookie = htonll(0);
 293     fm->cookie_mask = htonll(0);
 294     if (command == OFPFC_MODIFY || command == OFPFC_MODIFY_STRICT) {
 295         /* For modify, by default, don't update the cookie. */
 296         fm->new_cookie = OVS_BE64_MAX;
 297     } else{
 298         fm->new_cookie = htonll(0);
 299     }
 300     fm->modify_cookie = false;
 301     fm->table_id = 0xff;
 302     fm->command = command;
 303     fm->idle_timeout = OFP_FLOW_PERMANENT;
 304     fm->hard_timeout = OFP_FLOW_PERMANENT;
 305     fm->buffer_id = UINT32_MAX;
 306     fm->out_port = OFPP_ANY;
 307     fm->flags = 0;
 308     fm->importance = 0;
 309     fm->out_group = OFPG11_ANY;
 310     fm->delete_reason = OFPRR_DELETE;
 311     if (fields & F_ACTIONS) {
 312         act_str = extract_actions(string);
 313         if (!act_str) {
 314             return xstrdup("must specify an action");
 315         }
 316     }
 317     for (name = strtok_r(string, "=, \t\r\n", &save_ptr); name;
 318          name = strtok_r(NULL, "=, \t\r\n", &save_ptr)) {
 319         const struct protocol *p;
 320         char *error = NULL;
 321
 322         if (parse_protocol(name, &p)) {
 323             match_set_dl_type(&fm->match, htons(p->dl_type));
 324             if (p->nw_proto) {
 325                 match_set_nw_proto(&fm->match, p->nw_proto);
 326             }
 327         } else if (fields & F_FLAGS && !strcmp(name, "send_flow_rem")) {
 328             fm->flags |= OFPUTIL_FF_SEND_FLOW_REM;
 329         } else if (fields & F_FLAGS && !strcmp(name, "check_overlap")) {
 330             fm->flags |= OFPUTIL_FF_CHECK_OVERLAP;
 331         } else if (fields & F_FLAGS && !strcmp(name, "reset_counts")) {
 332             fm->flags |= OFPUTIL_FF_RESET_COUNTS;
 333             *usable_protocols &= OFPUTIL_P_OF12_UP;
 334         } else if (fields & F_FLAGS && !strcmp(name, "no_packet_counts")) {
 335             fm->flags |= OFPUTIL_FF_NO_PKT_COUNTS;
 336             *usable_protocols &= OFPUTIL_P_OF13_UP;
 337         } else if (fields & F_FLAGS && !strcmp(name, "no_byte_counts")) {
 338             fm->flags |= OFPUTIL_FF_NO_BYT_COUNTS;
 339             *usable_protocols &= OFPUTIL_P_OF13_UP;
 340         } else if (!strcmp(name, "no_readonly_table")
 341                    || !strcmp(name, "allow_hidden_fields")) {
 342              /* ignore these fields. */
 343         } else {
 344             char *value;
 345
 346             value = strtok_r(NULL, ", \t\r\n", &save_ptr);
 347             if (!value) {
 348                 return xasprintf("field %s missing value", name);
 349             }
 350
 351             if (!strcmp(name, "table")) {
 352                 error = str_to_u8(value, "table", &fm->table_id);
 353                 if (fm->table_id != 0xff) {
 354                     *usable_protocols &= OFPUTIL_P_TID;
 355                 }
 356             } else if (!strcmp(name, "out_port")) {
 357                 if (!ofputil_port_from_string(value, &fm->out_port)) {
 358                     error = xasprintf("%s is not a valid OpenFlow port",
 359                                       value);
 360                 }
 361             } else if (fields & F_PRIORITY && !strcmp(name, "priority")) {
 362                 uint16_t priority = 0;
 363
 364                 error = str_to_u16(value, name, &priority);
 365                 fm->priority = priority;
 366             } else if (fields & F_TIMEOUT && !strcmp(name, "idle_timeout")) {
 367                 error = str_to_u16(value, name, &fm->idle_timeout);
 368             } else if (fields & F_TIMEOUT && !strcmp(name, "hard_timeout")) {
 369                 error = str_to_u16(value, name, &fm->hard_timeout);
 370             } else if (fields & F_IMPORTANCE && !strcmp(name, "importance")) {
 371                 error = str_to_u16(value, name, &fm->importance);
 372             } else if (!strcmp(name, "cookie")) {
 373                 char *mask = strchr(value, '/');
 374
 375                 if (mask) {
 376                     /* A mask means we're searching for a cookie. */
 377                     if (command == OFPFC_ADD) {
 378                         return xstrdup("flow additions cannot use "
 379                                        "a cookie mask");
 380                     }
 381                     *mask = '\0';
 382                     error = str_to_be64(value, &fm->cookie);
 383                     if (error) {
 384                         return error;
 385                     }
 386                     error = str_to_be64(mask + 1, &fm->cookie_mask);
 387
 388                     /* Matching of the cookie is only supported through NXM or
 389                      * OF1.1+. */
 390                     if (fm->cookie_mask != htonll(0)) {
 391                         *usable_protocols &= OFPUTIL_P_NXM_OF11_UP;
 392                     }
 393                 } else {
 394                     /* No mask means that the cookie is being set. */
 395                     if (command != OFPFC_ADD && command != OFPFC_MODIFY
 396                         && command != OFPFC_MODIFY_STRICT) {
 397                         return xstrdup("cannot set cookie");
 398                     }
 399                     error = str_to_be64(value, &fm->new_cookie);
 400                     fm->modify_cookie = true;
 401                 }
 402             } else if (mf_from_name(name)) {
 403                 error = parse_field(mf_from_name(name), value, &fm->match,
 404                                     usable_protocols);
 405             } else if (!strcmp(name, "duration")
 406                        || !strcmp(name, "n_packets")
 407                        || !strcmp(name, "n_bytes")
 408                        || !strcmp(name, "idle_age")
 409                        || !strcmp(name, "hard_age")) {
 410                 /* Ignore these, so that users can feed the output of
 411                  * "ovs-ofctl dump-flows" back into commands that parse
 412                  * flows. */
 413             } else {
 414                 error = xasprintf("unknown keyword %s", name);
 415             }
 416
 417             if (error) {
 418                 return error;
 419             }
 420         }
 421     }
 422     /* Check for usable protocol interdependencies between match fields. */
 423     if (fm->match.flow.dl_type == htons(ETH_TYPE_IPV6)) {
 424         const struct flow_wildcards *wc = &fm->match.wc;
 425         /* Only NXM and OXM support matching L3 and L4 fields within IPv6.
 426          *
 427          * (IPv6 specific fields as well as arp_sha, arp_tha, nw_frag, and
 428          *  nw_ttl are covered elsewhere so they don't need to be included in
 429          *  this test too.)
 430          */
 431         if (wc->masks.nw_proto || wc->masks.nw_tos
 432             || wc->masks.tp_src || wc->masks.tp_dst) {
 433             *usable_protocols &= OFPUTIL_P_NXM_OXM_ANY;
 434         }
 435     }
 436     if (!fm->cookie_mask && fm->new_cookie == OVS_BE64_MAX
 437         && (command == OFPFC_MODIFY || command == OFPFC_MODIFY_STRICT)) {
 438         /* On modifies without a mask, we are supposed to add a flow if
 439          * one does not exist.  If a cookie wasn't been specified, use a
 440          * default of zero. */
 441         fm->new_cookie = htonll(0);
 442     }
 443     if (fields & F_ACTIONS) {
 444         enum ofputil_protocol action_usable_protocols;
 445         struct ofpbuf ofpacts;
 446         char *error;
 447
 448         ofpbuf_init(&ofpacts, 32);
 449         error = ofpacts_parse_instructions(act_str, &ofpacts,
 450                                            &action_usable_protocols);
 451         *usable_protocols &= action_usable_protocols;
 452         if (!error) {
 453             enum ofperr err;
 454
 455             err = ofpacts_check(ofpacts.data, ofpacts.size, &fm->match.flow,
 456                                 OFPP_MAX, fm->table_id, 255, usable_protocols);
 457             if (!err && !usable_protocols) {
 458                 err = OFPERR_OFPBAC_MATCH_INCONSISTENT;
 459             }
 460             if (err) {
 461                 error = xasprintf("actions are invalid with specified match "
 462                                   "(%s)", ofperr_to_string(err));
 463             }
 464
 465         }
 466         if (error) {
 467             ofpbuf_uninit(&ofpacts);
 468             return error;
 469         }
 470
 471         fm->ofpacts_len = ofpacts.size;
 472         fm->ofpacts = ofpbuf_steal_data(&ofpacts);
 473     } else {
 474         fm->ofpacts_len = 0;
 475         fm->ofpacts = NULL;
 476     }
 477
 478     return NULL;
 479 }
 480
 481 /* Convert 'str_' (as described in the Flow Syntax section of the ovs-ofctl man
 482  * page) into 'fm' for sending the specified flow_mod 'command' to a switch.
 483  * Returns the set of usable protocols in '*usable_protocols'.
 484  *
 485  * To parse syntax for an OFPT_FLOW_MOD (or NXT_FLOW_MOD), use an OFPFC_*
 486  * constant for 'command'.  To parse syntax for an OFPST_FLOW or
 487  * OFPST_AGGREGATE (or NXST_FLOW or NXST_AGGREGATE), use -1 for 'command'.
 488  *
 489  * Returns NULL if successful, otherwise a malloc()'d string describing the
 490  * error.  The caller is responsible for freeing the returned string. */
 491 char * OVS_WARN_UNUSED_RESULT
 492 parse_ofp_str(struct ofputil_flow_mod *fm, int command, const char *str_,
 493               enum ofputil_protocol *usable_protocols)
 494 {
 495     char *string = xstrdup(str_);
 496     char *error;
 497
 498     error = parse_ofp_str__(fm, command, string, usable_protocols);
 499     if (error) {
 500         fm->ofpacts = NULL;
 501         fm->ofpacts_len = 0;
 502     }
 503
 504     free(string);
 505     return error;
 506 }
 507
 508 static char * OVS_WARN_UNUSED_RESULT
 509 parse_ofp_meter_mod_str__(struct ofputil_meter_mod *mm, char *string,
 510                           struct ofpbuf *bands, int command,
 511                           enum ofputil_protocol *usable_protocols)
 512 {
 513     enum {
 514         F_METER = 1 << 0,
 515         F_FLAGS = 1 << 1,
 516         F_BANDS = 1 << 2,
 517     } fields;
 518     char *save_ptr = NULL;
 519     char *band_str = NULL;
 520     char *name;
 521
 522     /* Meters require at least OF 1.3. */
 523     *usable_protocols = OFPUTIL_P_OF13_UP;
 524
 525     switch (command) {
 526     case -1:
 527         fields = F_METER;
 528         break;
 529
 530     case OFPMC13_ADD:
 531         fields = F_METER | F_FLAGS | F_BANDS;
 532         break;
 533
 534     case OFPMC13_DELETE:
 535         fields = F_METER;
 536         break;
 537
 538     case OFPMC13_MODIFY:
 539         fields = F_METER | F_FLAGS | F_BANDS;
 540         break;
 541
 542     default:
 543         OVS_NOT_REACHED();
 544     }
 545
 546     mm->command = command;
 547     mm->meter.meter_id = 0;
 548     mm->meter.flags = 0;
 549     if (fields & F_BANDS) {
 550         band_str = strstr(string, "band");
 551         if (!band_str) {
 552             return xstrdup("must specify bands");
 553         }
 554         *band_str = '\0';
 555
 556         band_str = strchr(band_str + 1, '=');
 557         if (!band_str) {
 558             return xstrdup("must specify bands");
 559         }
 560
 561         band_str++;
 562     }
 563     for (name = strtok_r(string, "=, \t\r\n", &save_ptr); name;
 564          name = strtok_r(NULL, "=, \t\r\n", &save_ptr)) {
 565
 566         if (fields & F_FLAGS && !strcmp(name, "kbps")) {
 567             mm->meter.flags |= OFPMF13_KBPS;
 568         } else if (fields & F_FLAGS && !strcmp(name, "pktps")) {
 569             mm->meter.flags |= OFPMF13_PKTPS;
 570         } else if (fields & F_FLAGS && !strcmp(name, "burst")) {
 571             mm->meter.flags |= OFPMF13_BURST;
 572         } else if (fields & F_FLAGS && !strcmp(name, "stats")) {
 573             mm->meter.flags |= OFPMF13_STATS;
 574         } else {
 575             char *value;
 576
 577             value = strtok_r(NULL, ", \t\r\n", &save_ptr);
 578             if (!value) {
 579                 return xasprintf("field %s missing value", name);
 580             }
 581
 582             if (!strcmp(name, "meter")) {
 583                 if (!strcmp(value, "all")) {
 584                     mm->meter.meter_id = OFPM13_ALL;
 585                 } else if (!strcmp(value, "controller")) {
 586                     mm->meter.meter_id = OFPM13_CONTROLLER;
 587                 } else if (!strcmp(value, "slowpath")) {
 588                     mm->meter.meter_id = OFPM13_SLOWPATH;
 589                 } else {
 590                     char *error = str_to_u32(value, &mm->meter.meter_id);
 591                     if (error) {
 592                         return error;
 593                     }
 594                     if (mm->meter.meter_id > OFPM13_MAX
 595                         || !mm->meter.meter_id) {
 596                         return xasprintf("invalid value for %s", name);
 597                     }
 598                 }
 599             } else {
 600                 return xasprintf("unknown keyword %s", name);
 601             }
 602         }
 603     }
 604     if (fields & F_METER && !mm->meter.meter_id) {
 605         return xstrdup("must specify 'meter'");
 606     }
 607     if (fields & F_FLAGS && !mm->meter.flags) {
 608         return xstrdup("meter must specify either 'kbps' or 'pktps'");
 609     }
 610
 611     if (fields & F_BANDS) {
 612         uint16_t n_bands = 0;
 613         struct ofputil_meter_band *band = NULL;
 614         int i;
 615
 616         for (name = strtok_r(band_str, "=, \t\r\n", &save_ptr); name;
 617              name = strtok_r(NULL, "=, \t\r\n", &save_ptr)) {
 618
 619             char *value;
 620
 621             value = strtok_r(NULL, ", \t\r\n", &save_ptr);
 622             if (!value) {
 623                 return xasprintf("field %s missing value", name);
 624             }
 625
 626             if (!strcmp(name, "type")) {
 627                 /* Start a new band */
 628                 band = ofpbuf_put_zeros(bands, sizeof *band);
 629                 n_bands++;
 630
 631                 if (!strcmp(value, "drop")) {
 632                     band->type = OFPMBT13_DROP;
 633                 } else if (!strcmp(value, "dscp_remark")) {
 634                     band->type = OFPMBT13_DSCP_REMARK;
 635                 } else {
 636                     return xasprintf("field %s unknown value %s", name, value);
 637                 }
 638             } else if (!band || !band->type) {
 639                 return xstrdup("band must start with the 'type' keyword");
 640             } else if (!strcmp(name, "rate")) {
 641                 char *error = str_to_u32(value, &band->rate);
 642                 if (error) {
 643                     return error;
 644                 }
 645             } else if (!strcmp(name, "burst_size")) {
 646                 char *error = str_to_u32(value, &band->burst_size);
 647                 if (error) {
 648                     return error;
 649                 }
 650             } else if (!strcmp(name, "prec_level")) {
 651                 char *error = str_to_u8(value, name, &band->prec_level);
 652                 if (error) {
 653                     return error;
 654                 }
 655             } else {
 656                 return xasprintf("unknown keyword %s", name);
 657             }
 658         }
 659         /* validate bands */
 660         if (!n_bands) {
 661             return xstrdup("meter must have bands");
 662         }
 663
 664         mm->meter.n_bands = n_bands;
 665         mm->meter.bands = ofpbuf_steal_data(bands);
 666
 667         for (i = 0; i < n_bands; ++i) {
 668             band = &mm->meter.bands[i];
 669
 670             if (!band->type) {
 671                 return xstrdup("band must have 'type'");
 672             }
 673             if (band->type == OFPMBT13_DSCP_REMARK) {
 674                 if (!band->prec_level) {
 675                     return xstrdup("'dscp_remark' band must have"
 676                                    " 'prec_level'");
 677                 }
 678             } else {
 679                 if (band->prec_level) {
 680                     return xstrdup("Only 'dscp_remark' band may have"
 681                                    " 'prec_level'");
 682                 }
 683             }
 684             if (!band->rate) {
 685                 return xstrdup("band must have 'rate'");
 686             }
 687             if (mm->meter.flags & OFPMF13_BURST) {
 688                 if (!band->burst_size) {
 689                     return xstrdup("band must have 'burst_size' "
 690                                    "when 'burst' flag is set");
 691                 }
 692             } else {
 693                 if (band->burst_size) {
 694                     return xstrdup("band may have 'burst_size' only "
 695                                    "when 'burst' flag is set");
 696                 }
 697             }
 698         }
 699     } else {
 700         mm->meter.n_bands = 0;
 701         mm->meter.bands = NULL;
 702     }
 703
 704     return NULL;
 705 }
 706
 707 /* Convert 'str_' (as described in the Flow Syntax section of the ovs-ofctl man
 708  * page) into 'mm' for sending the specified meter_mod 'command' to a switch.
 709  *
 710  * Returns NULL if successful, otherwise a malloc()'d string describing the
 711  * error.  The caller is responsible for freeing the returned string. */
 712 char * OVS_WARN_UNUSED_RESULT
 713 parse_ofp_meter_mod_str(struct ofputil_meter_mod *mm, const char *str_,
 714                         int command, enum ofputil_protocol *usable_protocols)
 715 {
 716     struct ofpbuf bands;
 717     char *string;
 718     char *error;
 719
 720     ofpbuf_init(&bands, 64);
 721     string = xstrdup(str_);
 722
 723     error = parse_ofp_meter_mod_str__(mm, string, &bands, command,
 724                                       usable_protocols);
 725
 726     free(string);
 727     ofpbuf_uninit(&bands);
 728
 729     return error;
 730 }
 731
 732 static char * OVS_WARN_UNUSED_RESULT
 733 parse_flow_monitor_request__(struct ofputil_flow_monitor_request *fmr,
 734                              const char *str_, char *string,
 735                              enum ofputil_protocol *usable_protocols)
 736 {
 737     static atomic_count id = ATOMIC_COUNT_INIT(0);
 738     char *save_ptr = NULL;
 739     char *name;
 740
 741     fmr->id = atomic_count_inc(&id);
 742
 743     fmr->flags = (NXFMF_INITIAL | NXFMF_ADD | NXFMF_DELETE | NXFMF_MODIFY
 744                   | NXFMF_OWN | NXFMF_ACTIONS);
 745     fmr->out_port = OFPP_NONE;
 746     fmr->table_id = 0xff;
 747     match_init_catchall(&fmr->match);
 748
 749     for (name = strtok_r(string, "=, \t\r\n", &save_ptr); name;
 750          name = strtok_r(NULL, "=, \t\r\n", &save_ptr)) {
 751         const struct protocol *p;
 752
 753         if (!strcmp(name, "!initial")) {
 754             fmr->flags &= ~NXFMF_INITIAL;
 755         } else if (!strcmp(name, "!add")) {
 756             fmr->flags &= ~NXFMF_ADD;
 757         } else if (!strcmp(name, "!delete")) {
 758             fmr->flags &= ~NXFMF_DELETE;
 759         } else if (!strcmp(name, "!modify")) {
 760             fmr->flags &= ~NXFMF_MODIFY;
 761         } else if (!strcmp(name, "!actions")) {
 762             fmr->flags &= ~NXFMF_ACTIONS;
 763         } else if (!strcmp(name, "!own")) {
 764             fmr->flags &= ~NXFMF_OWN;
 765         } else if (parse_protocol(name, &p)) {
 766             match_set_dl_type(&fmr->match, htons(p->dl_type));
 767             if (p->nw_proto) {
 768                 match_set_nw_proto(&fmr->match, p->nw_proto);
 769             }
 770         } else {
 771             char *value;
 772
 773             value = strtok_r(NULL, ", \t\r\n", &save_ptr);
 774             if (!value) {
 775                 return xasprintf("%s: field %s missing value", str_, name);
 776             }
 777
 778             if (!strcmp(name, "table")) {
 779                 char *error = str_to_u8(value, "table", &fmr->table_id);
 780                 if (error) {
 781                     return error;
 782                 }
 783             } else if (!strcmp(name, "out_port")) {
 784                 fmr->out_port = u16_to_ofp(atoi(value));
 785             } else if (mf_from_name(name)) {
 786                 char *error;
 787
 788                 error = parse_field(mf_from_name(name), value, &fmr->match,
 789                                     usable_protocols);
 790                 if (error) {
 791                     return error;
 792                 }
 793             } else {
 794                 return xasprintf("%s: unknown keyword %s", str_, name);
 795             }
 796         }
 797     }
 798     return NULL;
 799 }
 800
 801 /* Convert 'str_' (as described in the documentation for the "monitor" command
 802  * in the ovs-ofctl man page) into 'fmr'.
 803  *
 804  * Returns NULL if successful, otherwise a malloc()'d string describing the
 805  * error.  The caller is responsible for freeing the returned string. */
 806 char * OVS_WARN_UNUSED_RESULT
 807 parse_flow_monitor_request(struct ofputil_flow_monitor_request *fmr,
 808                            const char *str_,
 809                            enum ofputil_protocol *usable_protocols)
 810 {
 811     char *string = xstrdup(str_);
 812     char *error = parse_flow_monitor_request__(fmr, str_, string,
 813                                                usable_protocols);
 814     free(string);
 815     return error;
 816 }
 817
 818 /* Parses 'string' as an OFPT_FLOW_MOD or NXT_FLOW_MOD with command 'command'
 819  * (one of OFPFC_*) into 'fm'.
 820  *
 821  * Returns NULL if successful, otherwise a malloc()'d string describing the
 822  * error.  The caller is responsible for freeing the returned string. */
 823 char * OVS_WARN_UNUSED_RESULT
 824 parse_ofp_flow_mod_str(struct ofputil_flow_mod *fm, const char *string,
 825                        uint16_t command,
 826                        enum ofputil_protocol *usable_protocols)
 827 {
 828     char *error = parse_ofp_str(fm, command, string, usable_protocols);
 829     if (!error) {
 830         /* Normalize a copy of the match.  This ensures that non-normalized
 831          * flows get logged but doesn't affect what gets sent to the switch, so
 832          * that the switch can do whatever it likes with the flow. */
 833         struct match match_copy = fm->match;
 834         ofputil_normalize_match(&match_copy);
 835     }
 836
 837     return error;
 838 }
 839
 840 /* Convert 'table_id' and 'flow_miss_handling' (as described for the
 841  * "mod-table" command in the ovs-ofctl man page) into 'tm' for sending the
 842  * specified table_mod 'command' to a switch.
 843  *
 844  * Returns NULL if successful, otherwise a malloc()'d string describing the
 845  * error.  The caller is responsible for freeing the returned string. */
 846 char * OVS_WARN_UNUSED_RESULT
 847 parse_ofp_table_mod(struct ofputil_table_mod *tm, const char *table_id,
 848                     const char *flow_miss_handling,
 849                     enum ofputil_protocol *usable_protocols)
 850 {
 851     /* Table mod requires at least OF 1.1. */
 852     *usable_protocols = OFPUTIL_P_OF11_UP;
 853
 854     if (!strcasecmp(table_id, "all")) {
 855         tm->table_id = OFPTT_ALL;
 856     } else {
 857         char *error = str_to_u8(table_id, "table_id", &tm->table_id);
 858         if (error) {
 859             return error;
 860         }
 861     }
 862
 863     if (strcmp(flow_miss_handling, "controller") == 0) {
 864         tm->miss_config = OFPUTIL_TABLE_MISS_CONTROLLER;
 865     } else if (strcmp(flow_miss_handling, "continue") == 0) {
 866         tm->miss_config = OFPUTIL_TABLE_MISS_CONTINUE;
 867     } else if (strcmp(flow_miss_handling, "drop") == 0) {
 868         tm->miss_config = OFPUTIL_TABLE_MISS_DROP;
 869     } else {
 870         return xasprintf("invalid flow_miss_handling %s", flow_miss_handling);
 871     }
 872
 873     if (tm->table_id == 0xfe
 874         && tm->miss_config == OFPUTIL_TABLE_MISS_CONTINUE) {
 875         return xstrdup("last table's flow miss handling can not be continue");
 876     }
 877
 878     return NULL;
 879 }
 880
 881
 882 /* Opens file 'file_name' and reads each line as a flow_mod of the specified
 883  * type (one of OFPFC_*).  Stores each flow_mod in '*fm', an array allocated
 884  * on the caller's behalf, and the number of flow_mods in '*n_fms'.
 885  *
 886  * Returns NULL if successful, otherwise a malloc()'d string describing the
 887  * error.  The caller is responsible for freeing the returned string. */
 888 char * OVS_WARN_UNUSED_RESULT
 889 parse_ofp_flow_mod_file(const char *file_name, uint16_t command,
 890                         struct ofputil_flow_mod **fms, size_t *n_fms,
 891                         enum ofputil_protocol *usable_protocols)
 892 {
 893     size_t allocated_fms;
 894     int line_number;
 895     FILE *stream;
 896     struct ds s;
 897
 898     *usable_protocols = OFPUTIL_P_ANY;
 899
 900     *fms = NULL;
 901     *n_fms = 0;
 902
 903     stream = !strcmp(file_name, "-") ? stdin : fopen(file_name, "r");
 904     if (stream == NULL) {
 905         return xasprintf("%s: open failed (%s)",
 906                          file_name, ovs_strerror(errno));
 907     }
 908
 909     allocated_fms = *n_fms;
 910     ds_init(&s);
 911     line_number = 0;
 912     while (!ds_get_preprocessed_line(&s, stream, &line_number)) {
 913         char *error;
 914         enum ofputil_protocol usable;
 915
 916         if (*n_fms >= allocated_fms) {
 917             *fms = x2nrealloc(*fms, &allocated_fms, sizeof **fms);
 918         }
 919         error = parse_ofp_flow_mod_str(&(*fms)[*n_fms], ds_cstr(&s), command,
 920                                        &usable);
 921         if (error) {
 922             size_t i;
 923
 924             for (i = 0; i < *n_fms; i++) {
 925                 free(CONST_CAST(struct ofpact *, (*fms)[i].ofpacts));
 926             }
 927             free(*fms);
 928             *fms = NULL;
 929             *n_fms = 0;
 930
 931             ds_destroy(&s);
 932             if (stream != stdin) {
 933                 fclose(stream);
 934             }
 935
 936             return xasprintf("%s:%d: %s", file_name, line_number, error);
 937         }
 938         *usable_protocols &= usable; /* Each line can narrow the set. */
 939         *n_fms += 1;
 940     }
 941
 942     ds_destroy(&s);
 943     if (stream != stdin) {
 944         fclose(stream);
 945     }
 946     return NULL;
 947 }
 948
 949 char * OVS_WARN_UNUSED_RESULT
 950 parse_ofp_flow_stats_request_str(struct ofputil_flow_stats_request *fsr,
 951                                  bool aggregate, const char *string,
 952                                  enum ofputil_protocol *usable_protocols)
 953 {
 954     struct ofputil_flow_mod fm;
 955     char *error;
 956
 957     error = parse_ofp_str(&fm, -1, string, usable_protocols);
 958     if (error) {
 959         return error;
 960     }
 961
 962     /* Special table ID support not required for stats requests. */
 963     if (*usable_protocols & OFPUTIL_P_OF10_STD_TID) {
 964         *usable_protocols |= OFPUTIL_P_OF10_STD;
 965     }
 966     if (*usable_protocols & OFPUTIL_P_OF10_NXM_TID) {
 967         *usable_protocols |= OFPUTIL_P_OF10_NXM;
 968     }
 969
 970     fsr->aggregate = aggregate;
 971     fsr->cookie = fm.cookie;
 972     fsr->cookie_mask = fm.cookie_mask;
 973     fsr->match = fm.match;
 974     fsr->out_port = fm.out_port;
 975     fsr->out_group = fm.out_group;
 976     fsr->table_id = fm.table_id;
 977     return NULL;
 978 }
 979
 980 /* Parses a specification of a flow from 's' into 'flow'.  's' must take the
 981  * form FIELD=VALUE[,FIELD=VALUE]... where each FIELD is the name of a
 982  * mf_field.  Fields must be specified in a natural order for satisfying
 983  * prerequisites. If 'mask' is specified, fills the mask field for each of the
 984  * field specified in flow. If the map, 'names_portno' is specfied, converts
 985  * the in_port name into port no while setting the 'flow'.
 986  *
 987  * Returns NULL on success, otherwise a malloc()'d string that explains the
 988  * problem. */
 989 char *
 990 parse_ofp_exact_flow(struct flow *flow, struct flow *mask, const char *s,
 991                      const struct simap *portno_names)
 992 {
 993     char *pos, *key, *value_s;
 994     char *error = NULL;
 995     char *copy;
 996
 997     memset(flow, 0, sizeof *flow);
 998     if (mask) {
 999         memset(mask, 0, sizeof *mask);
1000     }
1001
1002     pos = copy = xstrdup(s);
1003     while (ofputil_parse_key_value(&pos, &key, &value_s)) {
1004         const struct protocol *p;
1005         if (parse_protocol(key, &p)) {
1006             if (flow->dl_type) {
1007                 error = xasprintf("%s: Ethernet type set multiple times", s);
1008                 goto exit;
1009             }
1010             flow->dl_type = htons(p->dl_type);
1011             if (mask) {
1012                 mask->dl_type = OVS_BE16_MAX;
1013             }
1014
1015             if (p->nw_proto) {
1016                 if (flow->nw_proto) {
1017                     error = xasprintf("%s: network protocol set "
1018                                       "multiple times", s);
1019                     goto exit;
1020                 }
1021                 flow->nw_proto = p->nw_proto;
1022                 if (mask) {
1023                     mask->nw_proto = UINT8_MAX;
1024                 }
1025             }
1026         } else {
1027             const struct mf_field *mf;
1028             union mf_value value;
1029             char *field_error;
1030
1031             mf = mf_from_name(key);
1032             if (!mf) {
1033                 error = xasprintf("%s: unknown field %s", s, key);
1034                 goto exit;
1035             }
1036
1037             if (!mf_are_prereqs_ok(mf, flow)) {
1038                 error = xasprintf("%s: prerequisites not met for setting %s",
1039                                   s, key);
1040                 goto exit;
1041             }
1042
1043             if (!mf_is_zero(mf, flow)) {
1044                 error = xasprintf("%s: field %s set multiple times", s, key);
1045                 goto exit;
1046             }
1047
1048             if (!strcmp(key, "in_port")
1049                 && portno_names
1050                 && simap_contains(portno_names, value_s)) {
1051                 flow->in_port.ofp_port = u16_to_ofp(
1052                     simap_get(portno_names, value_s));
1053                 if (mask) {
1054                     mask->in_port.ofp_port = u16_to_ofp(ntohs(OVS_BE16_MAX));
1055                 }
1056             } else {
1057                 field_error = mf_parse_value(mf, value_s, &value);
1058                 if (field_error) {
1059                     error = xasprintf("%s: bad value for %s (%s)",
1060                                       s, key, field_error);
1061                     free(field_error);
1062                     goto exit;
1063                 }
1064
1065                 mf_set_flow_value(mf, &value, flow);
1066                 if (mask) {
1067                     mf_mask_field(mf, mask);
1068                 }
1069             }
1070         }
1071     }
1072
1073     if (!flow->in_port.ofp_port) {
1074         flow->in_port.ofp_port = OFPP_NONE;
1075     }
1076
1077 exit:
1078     free(copy);
1079
1080     if (error) {
1081         memset(flow, 0, sizeof *flow);
1082         if (mask) {
1083             memset(mask, 0, sizeof *mask);
1084         }
1085     }
1086     return error;
1087 }
1088
1089 static char * OVS_WARN_UNUSED_RESULT
1090 parse_bucket_str(struct ofputil_bucket *bucket, char *str_,
1091                   enum ofputil_protocol *usable_protocols)
1092 {
1093     char *pos, *key, *value;
1094     struct ofpbuf ofpacts;
1095     struct ds actions;
1096     char *error;
1097
1098     bucket->weight = 1;
1099     bucket->bucket_id = OFPG15_BUCKET_ALL;
1100     bucket->watch_port = OFPP_ANY;
1101     bucket->watch_group = OFPG11_ANY;
1102
1103     ds_init(&actions);
1104
1105     pos = str_;
1106     error = NULL;
1107     while (ofputil_parse_key_value(&pos, &key, &value)) {
1108         if (!strcasecmp(key, "weight")) {
1109             error = str_to_u16(value, "weight", &bucket->weight);
1110         } else if (!strcasecmp(key, "watch_port")) {
1111             if (!ofputil_port_from_string(value, &bucket->watch_port)
1112                 || (ofp_to_u16(bucket->watch_port) >= ofp_to_u16(OFPP_MAX)
1113                     && bucket->watch_port != OFPP_ANY)) {
1114                 error = xasprintf("%s: invalid watch_port", value);
1115             }
1116         } else if (!strcasecmp(key, "watch_group")) {
1117             error = str_to_u32(value, &bucket->watch_group);
1118             if (!error && bucket->watch_group > OFPG_MAX) {
1119                 error = xasprintf("invalid watch_group id %"PRIu32,
1120                                   bucket->watch_group);
1121             }
1122         } else if (!strcasecmp(key, "bucket_id")) {
1123             error = str_to_u32(value, &bucket->bucket_id);
1124             if (!error && bucket->bucket_id > OFPG15_BUCKET_MAX) {
1125                 error = xasprintf("invalid bucket_id id %"PRIu32,
1126                                   bucket->bucket_id);
1127             }
1128             *usable_protocols &= OFPUTIL_P_OF15_UP;
1129         } else if (!strcasecmp(key, "action") || !strcasecmp(key, "actions")) {
1130             ds_put_format(&actions, "%s,", value);
1131         } else {
1132             ds_put_format(&actions, "%s(%s),", key, value);
1133         }
1134
1135         if (error) {
1136             ds_destroy(&actions);
1137             return error;
1138         }
1139     }
1140
1141     if (!actions.length) {
1142         return xstrdup("bucket must specify actions");
1143     }
1144     ds_chomp(&actions, ',');
1145
1146     ofpbuf_init(&ofpacts, 0);
1147     error = ofpacts_parse_actions(ds_cstr(&actions), &ofpacts,
1148                                   usable_protocols);
1149     ds_destroy(&actions);
1150     if (error) {
1151         ofpbuf_uninit(&ofpacts);
1152         return error;
1153     }
1154     bucket->ofpacts = ofpacts.data;
1155     bucket->ofpacts_len = ofpacts.size;
1156
1157     return NULL;
1158 }
1159
1160 static char * OVS_WARN_UNUSED_RESULT
1161 parse_ofp_group_mod_str__(struct ofputil_group_mod *gm, uint16_t command,
1162                           char *string,
1163                           enum ofputil_protocol *usable_protocols)
1164 {
1165     enum {
1166         F_GROUP_TYPE            = 1 << 0,
1167         F_BUCKETS               = 1 << 1,
1168         F_COMMAND_BUCKET_ID     = 1 << 2,
1169         F_COMMAND_BUCKET_ID_ALL = 1 << 3,
1170     } fields;
1171     char *save_ptr = NULL;
1172     bool had_type = false;
1173     bool had_command_bucket_id = false;
1174     char *name;
1175     struct ofputil_bucket *bucket;
1176     char *error = NULL;
1177
1178     *usable_protocols = OFPUTIL_P_OF11_UP;
1179
1180     switch (command) {
1181     case OFPGC11_ADD:
1182         fields = F_GROUP_TYPE | F_BUCKETS;
1183         break;
1184
1185     case OFPGC11_DELETE:
1186         fields = 0;
1187         break;
1188
1189     case OFPGC11_MODIFY:
1190         fields = F_GROUP_TYPE | F_BUCKETS;
1191         break;
1192
1193     case OFPGC15_INSERT_BUCKET:
1194         fields = F_BUCKETS | F_COMMAND_BUCKET_ID;
1195         *usable_protocols &= OFPUTIL_P_OF15_UP;
1196         break;
1197
1198     case OFPGC15_REMOVE_BUCKET:
1199         fields = F_COMMAND_BUCKET_ID | F_COMMAND_BUCKET_ID_ALL;
1200         *usable_protocols &= OFPUTIL_P_OF15_UP;
1201         break;
1202
1203     default:
1204         OVS_NOT_REACHED();
1205     }
1206
1207     memset(gm, 0, sizeof *gm);
1208     gm->command = command;
1209     gm->group_id = OFPG_ANY;
1210     gm->command_bucket_id = OFPG15_BUCKET_ALL;
1211     list_init(&gm->buckets);
1212     if (command == OFPGC11_DELETE && string[0] == '\0') {
1213         gm->group_id = OFPG_ALL;
1214         return NULL;
1215     }
1216
1217     *usable_protocols = OFPUTIL_P_OF11_UP;
1218
1219     if (fields & F_BUCKETS) {
1220         char *bkt_str = strstr(string, "bucket=");
1221
1222         if (bkt_str) {
1223             *bkt_str = '\0';
1224         }
1225
1226         while (bkt_str) {
1227             char *next_bkt_str;
1228
1229             bkt_str = strchr(bkt_str + 1, '=');
1230             if (!bkt_str) {
1231                 error = xstrdup("must specify bucket content");
1232                 goto out;
1233             }
1234             bkt_str++;
1235
1236             next_bkt_str = strstr(bkt_str, "bucket=");
1237             if (next_bkt_str) {
1238                 *next_bkt_str = '\0';
1239             }
1240
1241             bucket = xzalloc(sizeof(struct ofputil_bucket));
1242             error = parse_bucket_str(bucket, bkt_str, usable_protocols);
1243             if (error) {
1244                 free(bucket);
1245                 goto out;
1246             }
1247             list_push_back(&gm->buckets, &bucket->list_node);
1248
1249             bkt_str = next_bkt_str;
1250         }
1251     }
1252
1253     for (name = strtok_r(string, "=, \t\r\n", &save_ptr); name;
1254          name = strtok_r(NULL, "=, \t\r\n", &save_ptr)) {
1255         char *value;
1256
1257         value = strtok_r(NULL, ", \t\r\n", &save_ptr);
1258         if (!value) {
1259             error = xasprintf("field %s missing value", name);
1260             goto out;
1261         }
1262
1263         if (!strcmp(name, "command_bucket_id")) {
1264             if (!(fields & F_COMMAND_BUCKET_ID)) {
1265                 error = xstrdup("command bucket id is not needed");
1266                 goto out;
1267             }
1268             if (!strcmp(value, "all")) {
1269                 gm->command_bucket_id = OFPG15_BUCKET_ALL;
1270             } else if (!strcmp(value, "first")) {
1271                 gm->command_bucket_id = OFPG15_BUCKET_FIRST;
1272             } else if (!strcmp(value, "last")) {
1273                 gm->command_bucket_id = OFPG15_BUCKET_LAST;
1274             } else {
1275                 char *error = str_to_u32(value, &gm->command_bucket_id);
1276                 if (error) {
1277                     goto out;
1278                 }
1279                 if (gm->command_bucket_id > OFPG15_BUCKET_MAX
1280                     && (gm->command_bucket_id != OFPG15_BUCKET_FIRST
1281                         && gm->command_bucket_id != OFPG15_BUCKET_LAST
1282                         && gm->command_bucket_id != OFPG15_BUCKET_ALL)) {
1283                     error = xasprintf("invalid command bucket id %"PRIu32,
1284                                       gm->command_bucket_id);
1285                     goto out;
1286                 }
1287             }
1288             if (gm->command_bucket_id == OFPG15_BUCKET_ALL
1289                 && !(fields & F_COMMAND_BUCKET_ID_ALL)) {
1290                 error = xstrdup("command_bucket_id=all is not permitted");
1291                 goto out;
1292             }
1293             had_command_bucket_id = true;
1294         } else if (!strcmp(name, "group_id")) {
1295             if(!strcmp(value, "all")) {
1296                 gm->group_id = OFPG_ALL;
1297             } else {
1298                 char *error = str_to_u32(value, &gm->group_id);
1299                 if (error) {
1300                     goto out;
1301                 }
1302                 if (gm->group_id != OFPG_ALL && gm->group_id > OFPG_MAX) {
1303                     error = xasprintf("invalid group id %"PRIu32,
1304                                       gm->group_id);
1305                     goto out;
1306                 }
1307             }
1308         } else if (!strcmp(name, "type")){
1309             if (!(fields & F_GROUP_TYPE)) {
1310                 error = xstrdup("type is not needed");
1311                 goto out;
1312             }
1313             if (!strcmp(value, "all")) {
1314                 gm->type = OFPGT11_ALL;
1315             } else if (!strcmp(value, "select")) {
1316                 gm->type = OFPGT11_SELECT;
1317             } else if (!strcmp(value, "indirect")) {
1318                 gm->type = OFPGT11_INDIRECT;
1319             } else if (!strcmp(value, "ff") ||
1320                        !strcmp(value, "fast_failover")) {
1321                 gm->type = OFPGT11_FF;
1322             } else {
1323                 error = xasprintf("invalid group type %s", value);
1324                 goto out;
1325             }
1326             had_type = true;
1327         } else if (!strcmp(name, "bucket")) {
1328             error = xstrdup("bucket is not needed");
1329             goto out;
1330         } else {
1331             error = xasprintf("unknown keyword %s", name);
1332             goto out;
1333         }
1334     }
1335     if (gm->group_id == OFPG_ANY) {
1336         error = xstrdup("must specify a group_id");
1337         goto out;
1338     }
1339     if (fields & F_GROUP_TYPE && !had_type) {
1340         error = xstrdup("must specify a type");
1341         goto out;
1342     }
1343
1344     if (fields & F_COMMAND_BUCKET_ID) {
1345         if (!(fields & F_COMMAND_BUCKET_ID_ALL || had_command_bucket_id)) {
1346             error = xstrdup("must specify a command bucket id");
1347             goto out;
1348         }
1349     } else if (had_command_bucket_id) {
1350         error = xstrdup("command bucket id is not needed");
1351         goto out;
1352     }
1353
1354     /* Validate buckets. */
1355     LIST_FOR_EACH (bucket, list_node, &gm->buckets) {
1356         if (bucket->weight != 1 && gm->type != OFPGT11_SELECT) {
1357             error = xstrdup("Only select groups can have bucket weights.");
1358             goto out;
1359         }
1360     }
1361     if (gm->type == OFPGT11_INDIRECT && !list_is_short(&gm->buckets)) {
1362         error = xstrdup("Indirect groups can have at most one bucket.");
1363         goto out;
1364     }
1365
1366     return NULL;
1367  out:
1368     ofputil_bucket_list_destroy(&gm->buckets);
1369     return error;
1370 }
1371
1372 char * OVS_WARN_UNUSED_RESULT
1373 parse_ofp_group_mod_str(struct ofputil_group_mod *gm, uint16_t command,
1374                         const char *str_,
1375                         enum ofputil_protocol *usable_protocols)
1376 {
1377     char *string = xstrdup(str_);
1378     char *error = parse_ofp_group_mod_str__(gm, command, string,
1379                                             usable_protocols);
1380     free(string);
1381
1382     if (error) {
1383         ofputil_bucket_list_destroy(&gm->buckets);
1384     }
1385     return error;
1386 }
1387
1388 char * OVS_WARN_UNUSED_RESULT
1389 parse_ofp_group_mod_file(const char *file_name, uint16_t command,
1390                          struct ofputil_group_mod **gms, size_t *n_gms,
1391                          enum ofputil_protocol *usable_protocols)
1392 {
1393     size_t allocated_gms;
1394     int line_number;
1395     FILE *stream;
1396     struct ds s;
1397
1398     *gms = NULL;
1399     *n_gms = 0;
1400
1401     stream = !strcmp(file_name, "-") ? stdin : fopen(file_name, "r");
1402     if (stream == NULL) {
1403         return xasprintf("%s: open failed (%s)",
1404                          file_name, ovs_strerror(errno));
1405     }
1406
1407     allocated_gms = *n_gms;
1408     ds_init(&s);
1409     line_number = 0;
1410     *usable_protocols = OFPUTIL_P_OF11_UP;
1411     while (!ds_get_preprocessed_line(&s, stream, &line_number)) {
1412         enum ofputil_protocol usable;
1413         char *error;
1414
1415         if (*n_gms >= allocated_gms) {
1416             struct ofputil_group_mod *new_gms;
1417             size_t i;
1418
1419             new_gms = x2nrealloc(*gms, &allocated_gms, sizeof **gms);
1420             for (i = 0; i < *n_gms; i++) {
1421                 list_moved(&new_gms[i].buckets, &(*gms)[i].buckets);
1422             }
1423             *gms = new_gms;
1424         }
1425         error = parse_ofp_group_mod_str(&(*gms)[*n_gms], command, ds_cstr(&s),
1426                                         &usable);
1427         if (error) {
1428             size_t i;
1429
1430             for (i = 0; i < *n_gms; i++) {
1431                 ofputil_bucket_list_destroy(&(*gms)[i].buckets);
1432             }
1433             free(*gms);
1434             *gms = NULL;
1435             *n_gms = 0;
1436
1437             ds_destroy(&s);
1438             if (stream != stdin) {
1439                 fclose(stream);
1440             }
1441
1442             return xasprintf("%s:%d: %s", file_name, line_number, error);
1443         }
1444         *usable_protocols &= usable;
1445         *n_gms += 1;
1446     }
1447
1448     ds_destroy(&s);
1449     if (stream != stdin) {
1450         fclose(stream);
1451     }
1452     return NULL;
1453 }