lib/ofp-parse.c

   1 /*
   2  * Copyright (c) 2010, 2011, 2012 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 "autopath.h"
  26 #include "bundle.h"
  27 #include "byte-order.h"
  28 #include "dynamic-string.h"
  29 #include "learn.h"
  30 #include "meta-flow.h"
  31 #include "multipath.h"
  32 #include "netdev.h"
  33 #include "nx-match.h"
  34 #include "ofp-actions.h"
  35 #include "ofp-util.h"
  36 #include "ofpbuf.h"
  37 #include "openflow/openflow.h"
  38 #include "packets.h"
  39 #include "socket-util.h"
  40 #include "vconn.h"
  41 #include "vlog.h"
  42
  43 VLOG_DEFINE_THIS_MODULE(ofp_parse);
  44
  45 static void ofp_fatal(const char *flow, bool verbose, const char *format, ...)
  46     NO_RETURN;
  47
  48 static uint8_t
  49 str_to_table_id(const char *str)
  50 {
  51     int table_id;
  52
  53     if (!str_to_int(str, 10, &table_id) || table_id < 0 || table_id > 255) {
  54         ovs_fatal(0, "invalid table \"%s\"", str);
  55     }
  56     return table_id;
  57 }
  58
  59 static uint16_t
  60 str_to_u16(const char *str, const char *name)
  61 {
  62     int value;
  63
  64     if (!str_to_int(str, 0, &value) || value < 0 || value > 65535) {
  65         ovs_fatal(0, "invalid %s \"%s\"", name, str);
  66     }
  67     return value;
  68 }
  69
  70 static uint32_t
  71 str_to_u32(const char *str)
  72 {
  73     char *tail;
  74     uint32_t value;
  75
  76     if (!str[0]) {
  77         ovs_fatal(0, "missing required numeric argument");
  78     }
  79
  80     errno = 0;
  81     value = strtoul(str, &tail, 0);
  82     if (errno == EINVAL || errno == ERANGE || *tail) {
  83         ovs_fatal(0, "invalid numeric format %s", str);
  84     }
  85     return value;
  86 }
  87
  88 static uint64_t
  89 str_to_u64(const char *str)
  90 {
  91     char *tail;
  92     uint64_t value;
  93
  94     if (!str[0]) {
  95         ovs_fatal(0, "missing required numeric argument");
  96     }
  97
  98     errno = 0;
  99     value = strtoull(str, &tail, 0);
 100     if (errno == EINVAL || errno == ERANGE || *tail) {
 101         ovs_fatal(0, "invalid numeric format %s", str);
 102     }
 103     return value;
 104 }
 105
 106 static void
 107 str_to_mac(const char *str, uint8_t mac[6])
 108 {
 109     if (sscanf(str, ETH_ADDR_SCAN_FMT, ETH_ADDR_SCAN_ARGS(mac))
 110         != ETH_ADDR_SCAN_COUNT) {
 111         ovs_fatal(0, "invalid mac address %s", str);
 112     }
 113 }
 114
 115 static void
 116 str_to_ip(const char *str, ovs_be32 *ip)
 117 {
 118     struct in_addr in_addr;
 119
 120     if (lookup_ip(str, &in_addr)) {
 121         ovs_fatal(0, "%s: could not convert to IP address", str);
 122     }
 123     *ip = in_addr.s_addr;
 124 }
 125
 126 static void
 127 parse_enqueue(char *arg, struct ofpbuf *ofpacts)
 128 {
 129     char *sp = NULL;
 130     char *port = strtok_r(arg, ":q", &sp);
 131     char *queue = strtok_r(NULL, "", &sp);
 132     struct ofpact_enqueue *enqueue;
 133
 134     if (port == NULL || queue == NULL) {
 135         ovs_fatal(0, "\"enqueue\" syntax is \"enqueue:PORT:QUEUE\"");
 136     }
 137
 138     enqueue = ofpact_put_ENQUEUE(ofpacts);
 139     enqueue->port = str_to_u32(port);
 140     enqueue->queue = str_to_u32(queue);
 141 }
 142
 143 static void
 144 parse_output(char *arg, struct ofpbuf *ofpacts)
 145 {
 146     if (strchr(arg, '[')) {
 147         struct ofpact_output_reg *output_reg;
 148
 149         output_reg = ofpact_put_OUTPUT_REG(ofpacts);
 150         mf_parse_subfield(&output_reg->src, arg);
 151         output_reg->max_len = UINT16_MAX;
 152     } else {
 153         struct ofpact_output *output;
 154
 155         output = ofpact_put_OUTPUT(ofpacts);
 156         output->port = str_to_u32(arg);
 157         output->max_len = output->port == OFPP_CONTROLLER ? UINT16_MAX : 0;
 158     }
 159 }
 160
 161 static void
 162 parse_resubmit(char *arg, struct ofpbuf *ofpacts)
 163 {
 164     struct ofpact_resubmit *resubmit;
 165     char *in_port_s, *table_s;
 166
 167     resubmit = ofpact_put_RESUBMIT(ofpacts);
 168
 169     in_port_s = strsep(&arg, ",");
 170     if (in_port_s && in_port_s[0]) {
 171         if (!ofputil_port_from_string(in_port_s, &resubmit->in_port)) {
 172             resubmit->in_port = str_to_u32(in_port_s);
 173         }
 174     } else {
 175         resubmit->in_port = OFPP_IN_PORT;
 176     }
 177
 178     table_s = strsep(&arg, ",");
 179     resubmit->table_id = table_s && table_s[0] ? str_to_u32(table_s) : 255;
 180
 181     if (resubmit->in_port == OFPP_IN_PORT && resubmit->table_id == 255) {
 182         ovs_fatal(0, "at least one \"in_port\" or \"table\" must be specified "
 183                   " on resubmit");
 184     }
 185 }
 186
 187 static void
 188 parse_note(const char *arg, struct ofpbuf *ofpacts)
 189 {
 190     struct ofpact_note *note;
 191
 192     note = ofpact_put_NOTE(ofpacts);
 193     while (*arg != '\0') {
 194         uint8_t byte;
 195         bool ok;
 196
 197         if (*arg == '.') {
 198             arg++;
 199         }
 200         if (*arg == '\0') {
 201             break;
 202         }
 203
 204         byte = hexits_value(arg, 2, &ok);
 205         if (!ok) {
 206             ovs_fatal(0, "bad hex digit in `note' argument");
 207         }
 208         ofpbuf_put(ofpacts, &byte, 1);
 209
 210         note = ofpacts->l2;
 211         note->length++;
 212
 213         arg += 2;
 214     }
 215     ofpact_update_len(ofpacts, &note->ofpact);
 216 }
 217
 218 static void
 219 parse_fin_timeout(struct ofpbuf *b, char *arg)
 220 {
 221     struct ofpact_fin_timeout *oft = ofpact_put_FIN_TIMEOUT(b);
 222     char *key, *value;
 223
 224     while (ofputil_parse_key_value(&arg, &key, &value)) {
 225         if (!strcmp(key, "idle_timeout")) {
 226             oft->fin_idle_timeout = str_to_u16(value, key);
 227         } else if (!strcmp(key, "hard_timeout")) {
 228             oft->fin_hard_timeout = str_to_u16(value, key);
 229         } else {
 230             ovs_fatal(0, "invalid key '%s' in 'fin_timeout' argument", key);
 231         }
 232     }
 233 }
 234
 235 static void
 236 parse_controller(struct ofpbuf *b, char *arg)
 237 {
 238     enum ofp_packet_in_reason reason = OFPR_ACTION;
 239     uint16_t controller_id = 0;
 240     uint16_t max_len = UINT16_MAX;
 241
 242     if (!arg[0]) {
 243         /* Use defaults. */
 244     } else if (strspn(arg, "0123456789") == strlen(arg)) {
 245         max_len = str_to_u16(arg, "max_len");
 246     } else {
 247         char *name, *value;
 248
 249         while (ofputil_parse_key_value(&arg, &name, &value)) {
 250             if (!strcmp(name, "reason")) {
 251                 if (!ofputil_packet_in_reason_from_string(value, &reason)) {
 252                     ovs_fatal(0, "unknown reason \"%s\"", value);
 253                 }
 254             } else if (!strcmp(name, "max_len")) {
 255                 max_len = str_to_u16(value, "max_len");
 256             } else if (!strcmp(name, "id")) {
 257                 controller_id = str_to_u16(value, "id");
 258             } else {
 259                 ovs_fatal(0, "unknown key \"%s\" parsing controller action",
 260                           name);
 261             }
 262         }
 263     }
 264
 265     if (reason == OFPR_ACTION && controller_id == 0) {
 266         struct ofpact_output *output;
 267
 268         output = ofpact_put_OUTPUT(b);
 269         output->port = OFPP_CONTROLLER;
 270         output->max_len = max_len;
 271     } else {
 272         struct ofpact_controller *controller;
 273
 274         controller = ofpact_put_CONTROLLER(b);
 275         controller->max_len = max_len;
 276         controller->reason = reason;
 277         controller->controller_id = controller_id;
 278     }
 279 }
 280
 281 static void
 282 parse_named_action(enum ofputil_action_code code, const struct flow *flow,
 283                    char *arg, struct ofpbuf *ofpacts)
 284 {
 285     struct ofpact_tunnel *tunnel;
 286     uint16_t vid;
 287     ovs_be32 ip;
 288     uint8_t pcp;
 289     uint8_t tos;
 290
 291     switch (code) {
 292     case OFPUTIL_ACTION_INVALID:
 293         NOT_REACHED();
 294
 295     case OFPUTIL_OFPAT10_OUTPUT:
 296     case OFPUTIL_OFPAT11_OUTPUT:
 297         parse_output(arg, ofpacts);
 298         break;
 299
 300     case OFPUTIL_OFPAT10_SET_VLAN_VID:
 301     case OFPUTIL_OFPAT11_SET_VLAN_VID:
 302         vid = str_to_u32(arg);
 303         if (vid & ~VLAN_VID_MASK) {
 304             ovs_fatal(0, "%s: not a valid VLAN VID", arg);
 305         }
 306         ofpact_put_SET_VLAN_VID(ofpacts)->vlan_vid = vid;
 307         break;
 308
 309     case OFPUTIL_OFPAT10_SET_VLAN_PCP:
 310     case OFPUTIL_OFPAT11_SET_VLAN_PCP:
 311         pcp = str_to_u32(arg);
 312         if (pcp & ~7) {
 313             ovs_fatal(0, "%s: not a valid VLAN PCP", arg);
 314         }
 315         ofpact_put_SET_VLAN_PCP(ofpacts)->vlan_pcp = pcp;
 316         break;
 317
 318     case OFPUTIL_OFPAT10_STRIP_VLAN:
 319         ofpact_put_STRIP_VLAN(ofpacts);
 320         break;
 321
 322     case OFPUTIL_OFPAT10_SET_DL_SRC:
 323     case OFPUTIL_OFPAT11_SET_DL_SRC:
 324         str_to_mac(arg, ofpact_put_SET_ETH_SRC(ofpacts)->mac);
 325         break;
 326
 327     case OFPUTIL_OFPAT10_SET_DL_DST:
 328     case OFPUTIL_OFPAT11_SET_DL_DST:
 329         str_to_mac(arg, ofpact_put_SET_ETH_DST(ofpacts)->mac);
 330         break;
 331
 332     case OFPUTIL_OFPAT10_SET_NW_SRC:
 333     case OFPUTIL_OFPAT11_SET_NW_SRC:
 334         str_to_ip(arg, &ip);
 335         ofpact_put_SET_IPV4_SRC(ofpacts)->ipv4 = ip;
 336         break;
 337
 338     case OFPUTIL_OFPAT10_SET_NW_DST:
 339     case OFPUTIL_OFPAT11_SET_NW_DST:
 340         str_to_ip(arg, &ip);
 341         ofpact_put_SET_IPV4_DST(ofpacts)->ipv4 = ip;
 342         break;
 343
 344     case OFPUTIL_OFPAT10_SET_NW_TOS:
 345     case OFPUTIL_OFPAT11_SET_NW_TOS:
 346         tos = str_to_u32(arg);
 347         if (tos & ~IP_DSCP_MASK) {
 348             ovs_fatal(0, "%s: not a valid TOS", arg);
 349         }
 350         ofpact_put_SET_IPV4_DSCP(ofpacts)->dscp = tos;
 351         break;
 352
 353     case OFPUTIL_OFPAT10_SET_TP_SRC:
 354     case OFPUTIL_OFPAT11_SET_TP_SRC:
 355         ofpact_put_SET_L4_SRC_PORT(ofpacts)->port = str_to_u32(arg);
 356         break;
 357
 358     case OFPUTIL_OFPAT10_SET_TP_DST:
 359     case OFPUTIL_OFPAT11_SET_TP_DST:
 360         ofpact_put_SET_L4_DST_PORT(ofpacts)->port = str_to_u32(arg);
 361         break;
 362
 363     case OFPUTIL_OFPAT10_ENQUEUE:
 364         parse_enqueue(arg, ofpacts);
 365         break;
 366
 367     case OFPUTIL_NXAST_RESUBMIT:
 368         parse_resubmit(arg, ofpacts);
 369         break;
 370
 371     case OFPUTIL_NXAST_SET_TUNNEL:
 372     case OFPUTIL_NXAST_SET_TUNNEL64:
 373         tunnel = ofpact_put_SET_TUNNEL(ofpacts);
 374         tunnel->ofpact.compat = code;
 375         tunnel->tun_id = str_to_u64(arg);
 376         break;
 377
 378     case OFPUTIL_NXAST_SET_QUEUE:
 379         ofpact_put_SET_QUEUE(ofpacts)->queue_id = str_to_u32(arg);
 380         break;
 381
 382     case OFPUTIL_NXAST_POP_QUEUE:
 383         ofpact_put_POP_QUEUE(ofpacts);
 384         break;
 385
 386     case OFPUTIL_NXAST_REG_MOVE:
 387         nxm_parse_reg_move(ofpact_put_REG_MOVE(ofpacts), arg);
 388         break;
 389
 390     case OFPUTIL_NXAST_REG_LOAD:
 391         nxm_parse_reg_load(ofpact_put_REG_LOAD(ofpacts), arg);
 392         break;
 393
 394     case OFPUTIL_NXAST_NOTE:
 395         parse_note(arg, ofpacts);
 396         break;
 397
 398     case OFPUTIL_NXAST_MULTIPATH:
 399         multipath_parse(ofpact_put_MULTIPATH(ofpacts), arg);
 400         break;
 401
 402     case OFPUTIL_NXAST_AUTOPATH:
 403         autopath_parse(ofpact_put_AUTOPATH(ofpacts), arg);
 404         break;
 405
 406     case OFPUTIL_NXAST_BUNDLE:
 407         bundle_parse(arg, ofpacts);
 408         break;
 409
 410     case OFPUTIL_NXAST_BUNDLE_LOAD:
 411         bundle_parse_load(arg, ofpacts);
 412         break;
 413
 414     case OFPUTIL_NXAST_RESUBMIT_TABLE:
 415     case OFPUTIL_NXAST_OUTPUT_REG:
 416         NOT_REACHED();
 417
 418     case OFPUTIL_NXAST_LEARN:
 419         learn_parse(arg, flow, ofpacts);
 420         break;
 421
 422     case OFPUTIL_NXAST_EXIT:
 423         ofpact_put_EXIT(ofpacts);
 424         break;
 425
 426     case OFPUTIL_NXAST_DEC_TTL:
 427         ofpact_put_DEC_TTL(ofpacts);
 428         break;
 429
 430     case OFPUTIL_NXAST_FIN_TIMEOUT:
 431         parse_fin_timeout(ofpacts, arg);
 432         break;
 433
 434     case OFPUTIL_NXAST_CONTROLLER:
 435         parse_controller(ofpacts, arg);
 436         break;
 437     }
 438 }
 439
 440 static void
 441 str_to_ofpacts(const struct flow *flow, char *str, struct ofpbuf *ofpacts)
 442 {
 443     char *pos, *act, *arg;
 444     int n_actions;
 445
 446     pos = str;
 447     n_actions = 0;
 448     while (ofputil_parse_key_value(&pos, &act, &arg)) {
 449         uint16_t port;
 450         int code;
 451
 452         code = ofputil_action_code_from_name(act);
 453         if (code >= 0) {
 454             parse_named_action(code, flow, arg, ofpacts);
 455         } else if (!strcasecmp(act, "drop")) {
 456             if (n_actions) {
 457                 ovs_fatal(0, "Drop actions must not be preceded by other "
 458                           "actions");
 459             } else if (ofputil_parse_key_value(&pos, &act, &arg)) {
 460                 ovs_fatal(0, "Drop actions must not be followed by other "
 461                           "actions");
 462             }
 463             break;
 464         } else if (ofputil_port_from_string(act, &port)) {
 465             ofpact_put_OUTPUT(ofpacts)->port = port;
 466         } else {
 467             ovs_fatal(0, "Unknown action: %s", act);
 468         }
 469         n_actions++;
 470     }
 471     ofpact_pad(ofpacts);
 472 }
 473
 474 struct protocol {
 475     const char *name;
 476     uint16_t dl_type;
 477     uint8_t nw_proto;
 478 };
 479
 480 static bool
 481 parse_protocol(const char *name, const struct protocol **p_out)
 482 {
 483     static const struct protocol protocols[] = {
 484         { "ip", ETH_TYPE_IP, 0 },
 485         { "arp", ETH_TYPE_ARP, 0 },
 486         { "icmp", ETH_TYPE_IP, IPPROTO_ICMP },
 487         { "tcp", ETH_TYPE_IP, IPPROTO_TCP },
 488         { "udp", ETH_TYPE_IP, IPPROTO_UDP },
 489         { "ipv6", ETH_TYPE_IPV6, 0 },
 490         { "ip6", ETH_TYPE_IPV6, 0 },
 491         { "icmp6", ETH_TYPE_IPV6, IPPROTO_ICMPV6 },
 492         { "tcp6", ETH_TYPE_IPV6, IPPROTO_TCP },
 493         { "udp6", ETH_TYPE_IPV6, IPPROTO_UDP },
 494     };
 495     const struct protocol *p;
 496
 497     for (p = protocols; p < &protocols[ARRAY_SIZE(protocols)]; p++) {
 498         if (!strcmp(p->name, name)) {
 499             *p_out = p;
 500             return true;
 501         }
 502     }
 503     *p_out = NULL;
 504     return false;
 505 }
 506
 507 static void
 508 ofp_fatal(const char *flow, bool verbose, const char *format, ...)
 509 {
 510     va_list args;
 511
 512     if (verbose) {
 513         fprintf(stderr, "%s:\n", flow);
 514     }
 515
 516     va_start(args, format);
 517     ovs_fatal_valist(0, format, args);
 518 }
 519
 520 static void
 521 parse_field(const struct mf_field *mf, const char *s, struct cls_rule *rule)
 522 {
 523     union mf_value value, mask;
 524     char *error;
 525
 526     error = mf_parse(mf, s, &value, &mask);
 527     if (error) {
 528         ovs_fatal(0, "%s", error);
 529     }
 530
 531     mf_set(mf, &value, &mask, rule);
 532 }
 533
 534 /* Convert 'str_' (as described in the Flow Syntax section of the ovs-ofctl man
 535  * page) into 'fm' for sending the specified flow_mod 'command' to a switch.
 536  * If 'actions' is specified, an action must be in 'string' and may be expanded
 537  * or reallocated.
 538  *
 539  * To parse syntax for an OFPT_FLOW_MOD (or NXT_FLOW_MOD), use an OFPFC_*
 540  * constant for 'command'.  To parse syntax for an OFPST_FLOW or
 541  * OFPST_AGGREGATE (or NXST_FLOW or NXST_AGGREGATE), use -1 for 'command'. */
 542 void
 543 parse_ofp_str(struct ofputil_flow_mod *fm, int command, const char *str_,
 544               bool verbose)
 545 {
 546     enum {
 547         F_OUT_PORT = 1 << 0,
 548         F_ACTIONS = 1 << 1,
 549         F_TIMEOUT = 1 << 3,
 550         F_PRIORITY = 1 << 4,
 551         F_FLAGS = 1 << 5,
 552     } fields;
 553     char *string = xstrdup(str_);
 554     char *save_ptr = NULL;
 555     char *act_str = NULL;
 556     char *name;
 557
 558     switch (command) {
 559     case -1:
 560         fields = F_OUT_PORT;
 561         break;
 562
 563     case OFPFC_ADD:
 564         fields = F_ACTIONS | F_TIMEOUT | F_PRIORITY | F_FLAGS;
 565         break;
 566
 567     case OFPFC_DELETE:
 568         fields = F_OUT_PORT;
 569         break;
 570
 571     case OFPFC_DELETE_STRICT:
 572         fields = F_OUT_PORT | F_PRIORITY;
 573         break;
 574
 575     case OFPFC_MODIFY:
 576         fields = F_ACTIONS | F_TIMEOUT | F_PRIORITY | F_FLAGS;
 577         break;
 578
 579     case OFPFC_MODIFY_STRICT:
 580         fields = F_ACTIONS | F_TIMEOUT | F_PRIORITY | F_FLAGS;
 581         break;
 582
 583     default:
 584         NOT_REACHED();
 585     }
 586
 587     cls_rule_init_catchall(&fm->cr, OFP_DEFAULT_PRIORITY);
 588     fm->cookie = htonll(0);
 589     fm->cookie_mask = htonll(0);
 590     if (command == OFPFC_MODIFY || command == OFPFC_MODIFY_STRICT) {
 591         /* For modify, by default, don't update the cookie. */
 592         fm->new_cookie = htonll(UINT64_MAX);
 593     } else{
 594         fm->new_cookie = htonll(0);
 595     }
 596     fm->table_id = 0xff;
 597     fm->command = command;
 598     fm->idle_timeout = OFP_FLOW_PERMANENT;
 599     fm->hard_timeout = OFP_FLOW_PERMANENT;
 600     fm->buffer_id = UINT32_MAX;
 601     fm->out_port = OFPP_NONE;
 602     fm->flags = 0;
 603     if (fields & F_ACTIONS) {
 604         act_str = strstr(string, "action");
 605         if (!act_str) {
 606             ofp_fatal(str_, verbose, "must specify an action");
 607         }
 608         *act_str = '\0';
 609
 610         act_str = strchr(act_str + 1, '=');
 611         if (!act_str) {
 612             ofp_fatal(str_, verbose, "must specify an action");
 613         }
 614
 615         act_str++;
 616     }
 617     for (name = strtok_r(string, "=, \t\r\n", &save_ptr); name;
 618          name = strtok_r(NULL, "=, \t\r\n", &save_ptr)) {
 619         const struct protocol *p;
 620
 621         if (parse_protocol(name, &p)) {
 622             cls_rule_set_dl_type(&fm->cr, htons(p->dl_type));
 623             if (p->nw_proto) {
 624                 cls_rule_set_nw_proto(&fm->cr, p->nw_proto);
 625             }
 626         } else if (fields & F_FLAGS && !strcmp(name, "send_flow_rem")) {
 627             fm->flags |= OFPFF_SEND_FLOW_REM;
 628         } else if (fields & F_FLAGS && !strcmp(name, "check_overlap")) {
 629             fm->flags |= OFPFF_CHECK_OVERLAP;
 630         } else {
 631             char *value;
 632
 633             value = strtok_r(NULL, ", \t\r\n", &save_ptr);
 634             if (!value) {
 635                 ofp_fatal(str_, verbose, "field %s missing value", name);
 636             }
 637
 638             if (!strcmp(name, "table")) {
 639                 fm->table_id = str_to_table_id(value);
 640             } else if (!strcmp(name, "out_port")) {
 641                 fm->out_port = atoi(value);
 642             } else if (fields & F_PRIORITY && !strcmp(name, "priority")) {
 643                 fm->cr.priority = str_to_u16(value, name);
 644             } else if (fields & F_TIMEOUT && !strcmp(name, "idle_timeout")) {
 645                 fm->idle_timeout = str_to_u16(value, name);
 646             } else if (fields & F_TIMEOUT && !strcmp(name, "hard_timeout")) {
 647                 fm->hard_timeout = str_to_u16(value, name);
 648             } else if (!strcmp(name, "cookie")) {
 649                 char *mask = strchr(value, '/');
 650
 651                 if (mask) {
 652                     /* A mask means we're searching for a cookie. */
 653                     if (command == OFPFC_ADD) {
 654                         ofp_fatal(str_, verbose, "flow additions cannot use "
 655                                   "a cookie mask");
 656                     }
 657                     *mask = '\0';
 658                     fm->cookie = htonll(str_to_u64(value));
 659                     fm->cookie_mask = htonll(str_to_u64(mask+1));
 660                 } else {
 661                     /* No mask means that the cookie is being set. */
 662                     if (command != OFPFC_ADD && command != OFPFC_MODIFY
 663                             && command != OFPFC_MODIFY_STRICT) {
 664                         ofp_fatal(str_, verbose, "cannot set cookie");
 665                     }
 666                     fm->new_cookie = htonll(str_to_u64(value));
 667                 }
 668             } else if (mf_from_name(name)) {
 669                 parse_field(mf_from_name(name), value, &fm->cr);
 670             } else if (!strcmp(name, "duration")
 671                        || !strcmp(name, "n_packets")
 672                        || !strcmp(name, "n_bytes")) {
 673                 /* Ignore these, so that users can feed the output of
 674                  * "ovs-ofctl dump-flows" back into commands that parse
 675                  * flows. */
 676             } else {
 677                 ofp_fatal(str_, verbose, "unknown keyword %s", name);
 678             }
 679         }
 680     }
 681     if (!fm->cookie_mask && fm->new_cookie == htonll(UINT64_MAX)
 682             && (command == OFPFC_MODIFY || command == OFPFC_MODIFY_STRICT)) {
 683         /* On modifies without a mask, we are supposed to add a flow if
 684          * one does not exist.  If a cookie wasn't been specified, use a
 685          * default of zero. */
 686         fm->new_cookie = htonll(0);
 687     }
 688     if (fields & F_ACTIONS) {
 689         struct ofpbuf ofpacts;
 690
 691         ofpbuf_init(&ofpacts, 32);
 692         str_to_ofpacts(&fm->cr.flow, act_str, &ofpacts);
 693         fm->ofpacts_len = ofpacts.size;
 694         fm->ofpacts = ofpbuf_steal_data(&ofpacts);
 695     } else {
 696         fm->ofpacts_len = 0;
 697         fm->ofpacts = NULL;
 698     }
 699
 700     free(string);
 701 }
 702
 703 /* Parses 's' as a set of OpenFlow actions and appends the actions to
 704  * 'actions'.
 705  *
 706  * Prints an error on stderr and aborts the program if 's' syntax is
 707  * invalid. */
 708 void
 709 parse_ofpacts(const char *s_, struct ofpbuf *ofpacts)
 710 {
 711     char *s = xstrdup(s_);
 712     str_to_ofpacts(NULL, s, ofpacts);
 713     free(s);
 714 }
 715
 716 /* Parses 'string' as an OFPT_FLOW_MOD or NXT_FLOW_MOD with command 'command'
 717  * (one of OFPFC_*) into 'fm'. */
 718 void
 719 parse_ofp_flow_mod_str(struct ofputil_flow_mod *fm, const char *string,
 720                        uint16_t command, bool verbose)
 721 {
 722     struct cls_rule rule_copy;
 723
 724     parse_ofp_str(fm, command, string, verbose);
 725
 726     /* Normalize a copy of the rule.  This ensures that non-normalized flows
 727      * get logged but doesn't affect what gets sent to the switch, so that the
 728      * switch can do whatever it likes with the flow. */
 729     rule_copy = fm->cr;
 730     ofputil_normalize_rule(&rule_copy);
 731 }
 732
 733 void
 734 parse_ofp_flow_mod_file(const char *file_name, uint16_t command,
 735                         struct ofputil_flow_mod **fms, size_t *n_fms)
 736 {
 737     size_t allocated_fms;
 738     FILE *stream;
 739     struct ds s;
 740
 741     stream = !strcmp(file_name, "-") ? stdin : fopen(file_name, "r");
 742     if (stream == NULL) {
 743         ovs_fatal(errno, "%s: open", file_name);
 744     }
 745
 746     allocated_fms = *n_fms;
 747     ds_init(&s);
 748     while (!ds_get_preprocessed_line(&s, stream)) {
 749         if (*n_fms >= allocated_fms) {
 750             *fms = x2nrealloc(*fms, &allocated_fms, sizeof **fms);
 751         }
 752         parse_ofp_flow_mod_str(&(*fms)[*n_fms], ds_cstr(&s), command, false);
 753         *n_fms += 1;
 754     }
 755     ds_destroy(&s);
 756
 757     if (stream != stdin) {
 758         fclose(stream);
 759     }
 760 }
 761
 762 void
 763 parse_ofp_flow_stats_request_str(struct ofputil_flow_stats_request *fsr,
 764                                  bool aggregate, const char *string)
 765 {
 766     struct ofputil_flow_mod fm;
 767
 768     parse_ofp_str(&fm, -1, string, false);
 769     fsr->aggregate = aggregate;
 770     fsr->cookie = fm.cookie;
 771     fsr->cookie_mask = fm.cookie_mask;
 772     fsr->match = fm.cr;
 773     fsr->out_port = fm.out_port;
 774     fsr->table_id = fm.table_id;
 775 }
 776
 777 /* Parses a specification of a flow from 's' into 'flow'.  's' must take the
 778  * form FIELD=VALUE[,FIELD=VALUE]... where each FIELD is the name of a
 779  * mf_field.  Fields must be specified in a natural order for satisfying
 780  * prerequisites.
 781  *
 782  * Returns NULL on success, otherwise a malloc()'d string that explains the
 783  * problem. */
 784 char *
 785 parse_ofp_exact_flow(struct flow *flow, const char *s)
 786 {
 787     char *pos, *key, *value_s;
 788     char *error = NULL;
 789     char *copy;
 790
 791     memset(flow, 0, sizeof *flow);
 792
 793     pos = copy = xstrdup(s);
 794     while (ofputil_parse_key_value(&pos, &key, &value_s)) {
 795         const struct protocol *p;
 796         if (parse_protocol(key, &p)) {
 797             if (flow->dl_type) {
 798                 error = xasprintf("%s: Ethernet type set multiple times", s);
 799                 goto exit;
 800             }
 801             flow->dl_type = htons(p->dl_type);
 802
 803             if (p->nw_proto) {
 804                 if (flow->nw_proto) {
 805                     error = xasprintf("%s: network protocol set "
 806                                       "multiple times", s);
 807                     goto exit;
 808                 }
 809                 flow->nw_proto = p->nw_proto;
 810             }
 811         } else {
 812             const struct mf_field *mf;
 813             union mf_value value;
 814             char *field_error;
 815
 816             mf = mf_from_name(key);
 817             if (!mf) {
 818                 error = xasprintf("%s: unknown field %s", s, key);
 819                 goto exit;
 820             }
 821
 822             if (!mf_are_prereqs_ok(mf, flow)) {
 823                 error = xasprintf("%s: prerequisites not met for setting %s",
 824                                   s, key);
 825                 goto exit;
 826             }
 827
 828             if (!mf_is_zero(mf, flow)) {
 829                 error = xasprintf("%s: field %s set multiple times", s, key);
 830                 goto exit;
 831             }
 832
 833             field_error = mf_parse_value(mf, value_s, &value);
 834             if (field_error) {
 835                 error = xasprintf("%s: bad value for %s (%s)",
 836                                   s, key, field_error);
 837                 free(field_error);
 838                 goto exit;
 839             }
 840
 841             mf_set_flow_value(mf, &value, flow);
 842         }
 843     }
 844
 845 exit:
 846     free(copy);
 847
 848     if (error) {
 849         memset(flow, 0, sizeof *flow);
 850     }
 851     return error;
 852 }