lib/ofp-parse.c

   1 /*
   2  * Copyright (c) 2010, 2011 Nicira Networks.
   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 "netdev.h"
  32 #include "multipath.h"
  33 #include "nx-match.h"
  34 #include "ofp-util.h"
  35 #include "ofpbuf.h"
  36 #include "openflow/openflow.h"
  37 #include "packets.h"
  38 #include "socket-util.h"
  39 #include "vconn.h"
  40 #include "vlog.h"
  41
  42 VLOG_DEFINE_THIS_MODULE(ofp_parse);
  43
  44 static uint8_t
  45 str_to_table_id(const char *str)
  46 {
  47     int table_id;
  48
  49     if (!str_to_int(str, 10, &table_id) || table_id < 0 || table_id > 255) {
  50         ovs_fatal(0, "invalid table \"%s\"", str);
  51     }
  52     return table_id;
  53 }
  54
  55 static uint16_t
  56 str_to_u16(const char *str, const char *name)
  57 {
  58     int value;
  59
  60     if (!str_to_int(str, 0, &value) || value < 0 || value > 65535) {
  61         ovs_fatal(0, "invalid %s \"%s\"", name, str);
  62     }
  63     return value;
  64 }
  65
  66 static uint32_t
  67 str_to_u32(const char *str)
  68 {
  69     char *tail;
  70     uint32_t value;
  71
  72     if (!str[0]) {
  73         ovs_fatal(0, "missing required numeric argument");
  74     }
  75
  76     errno = 0;
  77     value = strtoul(str, &tail, 0);
  78     if (errno == EINVAL || errno == ERANGE || *tail) {
  79         ovs_fatal(0, "invalid numeric format %s", str);
  80     }
  81     return value;
  82 }
  83
  84 static uint64_t
  85 str_to_u64(const char *str)
  86 {
  87     char *tail;
  88     uint64_t value;
  89
  90     if (!str[0]) {
  91         ovs_fatal(0, "missing required numeric argument");
  92     }
  93
  94     errno = 0;
  95     value = strtoull(str, &tail, 0);
  96     if (errno == EINVAL || errno == ERANGE || *tail) {
  97         ovs_fatal(0, "invalid numeric format %s", str);
  98     }
  99     return value;
 100 }
 101
 102 static void
 103 str_to_mac(const char *str, uint8_t mac[6])
 104 {
 105     if (sscanf(str, ETH_ADDR_SCAN_FMT, ETH_ADDR_SCAN_ARGS(mac))
 106         != ETH_ADDR_SCAN_COUNT) {
 107         ovs_fatal(0, "invalid mac address %s", str);
 108     }
 109 }
 110
 111 static void
 112 str_to_ip(const char *str, ovs_be32 *ip)
 113 {
 114     struct in_addr in_addr;
 115
 116     if (lookup_ip(str, &in_addr)) {
 117         ovs_fatal(0, "%s: could not convert to IP address", str);
 118     }
 119     *ip = in_addr.s_addr;
 120 }
 121
 122 static struct ofp_action_output *
 123 put_output_action(struct ofpbuf *b, uint16_t port)
 124 {
 125     struct ofp_action_output *oao;
 126
 127     oao = ofputil_put_OFPAT_OUTPUT(b);
 128     oao->port = htons(port);
 129     return oao;
 130 }
 131
 132 static void
 133 parse_enqueue(struct ofpbuf *b, char *arg)
 134 {
 135     char *sp = NULL;
 136     char *port = strtok_r(arg, ":q", &sp);
 137     char *queue = strtok_r(NULL, "", &sp);
 138     struct ofp_action_enqueue *oae;
 139
 140     if (port == NULL || queue == NULL) {
 141         ovs_fatal(0, "\"enqueue\" syntax is \"enqueue:PORT:QUEUE\"");
 142     }
 143
 144     oae = ofputil_put_OFPAT_ENQUEUE(b);
 145     oae->port = htons(str_to_u32(port));
 146     oae->queue_id = htonl(str_to_u32(queue));
 147 }
 148
 149 static void
 150 parse_output(struct ofpbuf *b, char *arg)
 151 {
 152     if (strchr(arg, '[')) {
 153         struct nx_action_output_reg *naor;
 154         int ofs, n_bits;
 155         uint32_t src;
 156
 157         nxm_parse_field_bits(arg, &src, &ofs, &n_bits);
 158
 159         naor = ofputil_put_NXAST_OUTPUT_REG(b);
 160         naor->ofs_nbits = nxm_encode_ofs_nbits(ofs, n_bits);
 161         naor->src = htonl(src);
 162         naor->max_len = htons(UINT16_MAX);
 163     } else {
 164         put_output_action(b, str_to_u32(arg));
 165     }
 166 }
 167
 168 static void
 169 parse_resubmit(struct ofpbuf *b, char *arg)
 170 {
 171     struct nx_action_resubmit *nar;
 172     char *in_port_s, *table_s;
 173     uint16_t in_port;
 174     uint8_t table;
 175
 176     in_port_s = strsep(&arg, ",");
 177     if (in_port_s && in_port_s[0]) {
 178         if (!ofputil_port_from_string(in_port_s, &in_port)) {
 179             in_port = str_to_u32(in_port_s);
 180         }
 181     } else {
 182         in_port = OFPP_IN_PORT;
 183     }
 184
 185     table_s = strsep(&arg, ",");
 186     table = table_s && table_s[0] ? str_to_u32(table_s) : 255;
 187
 188     if (in_port == OFPP_IN_PORT && table == 255) {
 189         ovs_fatal(0, "at least one \"in_port\" or \"table\" must be specified "
 190                   " on resubmit");
 191     }
 192
 193     if (in_port != OFPP_IN_PORT && table == 255) {
 194         nar = ofputil_put_NXAST_RESUBMIT(b);
 195     } else {
 196         nar = ofputil_put_NXAST_RESUBMIT_TABLE(b);
 197         nar->table = table;
 198     }
 199     nar->in_port = htons(in_port);
 200 }
 201
 202 static void
 203 parse_set_tunnel(struct ofpbuf *b, const char *arg)
 204 {
 205     uint64_t tun_id = str_to_u64(arg);
 206     if (tun_id > UINT32_MAX) {
 207         ofputil_put_NXAST_SET_TUNNEL64(b)->tun_id = htonll(tun_id);
 208     } else {
 209         ofputil_put_NXAST_SET_TUNNEL(b)->tun_id = htonl(tun_id);
 210     }
 211 }
 212
 213 static void
 214 parse_note(struct ofpbuf *b, const char *arg)
 215 {
 216     size_t start_ofs = b->size;
 217     struct nx_action_note *nan;
 218     int remainder;
 219     size_t len;
 220
 221     nan = ofputil_put_NXAST_NOTE(b);
 222
 223     b->size -= sizeof nan->note;
 224     while (*arg != '\0') {
 225         uint8_t byte;
 226         bool ok;
 227
 228         if (*arg == '.') {
 229             arg++;
 230         }
 231         if (*arg == '\0') {
 232             break;
 233         }
 234
 235         byte = hexits_value(arg, 2, &ok);
 236         if (!ok) {
 237             ovs_fatal(0, "bad hex digit in `note' argument");
 238         }
 239         ofpbuf_put(b, &byte, 1);
 240
 241         arg += 2;
 242     }
 243
 244     len = b->size - start_ofs;
 245     remainder = len % OFP_ACTION_ALIGN;
 246     if (remainder) {
 247         ofpbuf_put_zeros(b, OFP_ACTION_ALIGN - remainder);
 248     }
 249     nan = (struct nx_action_note *)((char *)b->data + start_ofs);
 250     nan->len = htons(b->size - start_ofs);
 251 }
 252
 253 static void
 254 parse_named_action(enum ofputil_action_code code, const struct flow *flow,
 255                    struct ofpbuf *b, char *arg)
 256 {
 257     struct ofp_action_dl_addr *oada;
 258     struct ofp_action_vlan_pcp *oavp;
 259     struct ofp_action_vlan_vid *oavv;
 260     struct ofp_action_nw_addr *oana;
 261     struct ofp_action_tp_port *oata;
 262
 263     switch (code) {
 264     case OFPUTIL_OFPAT_OUTPUT:
 265         parse_output(b, arg);
 266         break;
 267
 268     case OFPUTIL_OFPAT_SET_VLAN_VID:
 269         oavv = ofputil_put_OFPAT_SET_VLAN_VID(b);
 270         oavv->vlan_vid = htons(str_to_u32(arg));
 271         break;
 272
 273     case OFPUTIL_OFPAT_SET_VLAN_PCP:
 274         oavp = ofputil_put_OFPAT_SET_VLAN_PCP(b);
 275         oavp->vlan_pcp = str_to_u32(arg);
 276         break;
 277
 278     case OFPUTIL_OFPAT_STRIP_VLAN:
 279         ofputil_put_OFPAT_STRIP_VLAN(b);
 280         break;
 281
 282     case OFPUTIL_OFPAT_SET_DL_SRC:
 283     case OFPUTIL_OFPAT_SET_DL_DST:
 284         oada = ofputil_put_action(code, b);
 285         str_to_mac(arg, oada->dl_addr);
 286         break;
 287
 288     case OFPUTIL_OFPAT_SET_NW_SRC:
 289     case OFPUTIL_OFPAT_SET_NW_DST:
 290         oana = ofputil_put_action(code, b);
 291         str_to_ip(arg, &oana->nw_addr);
 292         break;
 293
 294     case OFPUTIL_OFPAT_SET_NW_TOS:
 295         ofputil_put_OFPAT_SET_NW_TOS(b)->nw_tos = str_to_u32(arg);
 296         break;
 297
 298     case OFPUTIL_OFPAT_SET_TP_SRC:
 299     case OFPUTIL_OFPAT_SET_TP_DST:
 300         oata = ofputil_put_action(code, b);
 301         oata->tp_port = htons(str_to_u32(arg));
 302         break;
 303
 304     case OFPUTIL_OFPAT_ENQUEUE:
 305         parse_enqueue(b, arg);
 306         break;
 307
 308     case OFPUTIL_NXAST_RESUBMIT:
 309         parse_resubmit(b, arg);
 310         break;
 311
 312     case OFPUTIL_NXAST_SET_TUNNEL:
 313         parse_set_tunnel(b, arg);
 314         break;
 315
 316     case OFPUTIL_NXAST_SET_QUEUE:
 317         ofputil_put_NXAST_SET_QUEUE(b)->queue_id = htonl(str_to_u32(arg));
 318         break;
 319
 320     case OFPUTIL_NXAST_POP_QUEUE:
 321         ofputil_put_NXAST_POP_QUEUE(b);
 322         break;
 323
 324     case OFPUTIL_NXAST_REG_MOVE:
 325         nxm_parse_reg_move(ofputil_put_NXAST_REG_MOVE(b), arg);
 326         break;
 327
 328     case OFPUTIL_NXAST_REG_LOAD:
 329         nxm_parse_reg_load(ofputil_put_NXAST_REG_LOAD(b), arg);
 330         break;
 331
 332     case OFPUTIL_NXAST_NOTE:
 333         parse_note(b, arg);
 334         break;
 335
 336     case OFPUTIL_NXAST_SET_TUNNEL64:
 337         ofputil_put_NXAST_SET_TUNNEL64(b)->tun_id = htonll(str_to_u64(arg));
 338         break;
 339
 340     case OFPUTIL_NXAST_MULTIPATH:
 341         multipath_parse(ofputil_put_NXAST_MULTIPATH(b), arg);
 342         break;
 343
 344     case OFPUTIL_NXAST_AUTOPATH:
 345         autopath_parse(ofputil_put_NXAST_AUTOPATH(b), arg);
 346         break;
 347
 348     case OFPUTIL_NXAST_BUNDLE:
 349         bundle_parse(b, arg);
 350         break;
 351
 352     case OFPUTIL_NXAST_BUNDLE_LOAD:
 353         bundle_parse_load(b, arg);
 354         break;
 355
 356     case OFPUTIL_NXAST_RESUBMIT_TABLE:
 357     case OFPUTIL_NXAST_OUTPUT_REG:
 358         NOT_REACHED();
 359
 360     case OFPUTIL_NXAST_LEARN:
 361         learn_parse(b, arg, flow);
 362         break;
 363
 364     case OFPUTIL_NXAST_EXIT:
 365         ofputil_put_NXAST_EXIT(b);
 366         break;
 367     }
 368 }
 369
 370 static void
 371 str_to_action(const struct flow *flow, char *str, struct ofpbuf *b)
 372 {
 373     char *pos, *act, *arg;
 374     int n_actions;
 375
 376     pos = str;
 377     n_actions = 0;
 378     while (ofputil_parse_key_value(&pos, &act, &arg)) {
 379         uint16_t port;
 380         int code;
 381
 382         code = ofputil_action_code_from_name(act);
 383         if (code >= 0) {
 384             parse_named_action(code, flow, b, arg);
 385         } else if (!strcasecmp(act, "drop")) {
 386             /* A drop action in OpenFlow occurs by just not setting
 387              * an action. */
 388             if (n_actions) {
 389                 ovs_fatal(0, "Drop actions must not be preceded by other "
 390                           "actions");
 391             } else if (ofputil_parse_key_value(&pos, &act, &arg)) {
 392                 ovs_fatal(0, "Drop actions must not be followed by other "
 393                           "actions");
 394             }
 395             break;
 396         } else if (!strcasecmp(act, "CONTROLLER")) {
 397             struct ofp_action_output *oao;
 398             oao = put_output_action(b, OFPP_CONTROLLER);
 399
 400             /* Unless a numeric argument is specified, we send the whole
 401              * packet to the controller. */
 402             if (arg[0] && (strspn(arg, "0123456789") == strlen(arg))) {
 403                oao->max_len = htons(str_to_u32(arg));
 404             } else {
 405                 oao->max_len = htons(UINT16_MAX);
 406             }
 407         } else if (ofputil_port_from_string(act, &port)) {
 408             put_output_action(b, port);
 409         } else {
 410             ovs_fatal(0, "Unknown action: %s", act);
 411         }
 412         n_actions++;
 413     }
 414 }
 415
 416 struct protocol {
 417     const char *name;
 418     uint16_t dl_type;
 419     uint8_t nw_proto;
 420 };
 421
 422 static bool
 423 parse_protocol(const char *name, const struct protocol **p_out)
 424 {
 425     static const struct protocol protocols[] = {
 426         { "ip", ETH_TYPE_IP, 0 },
 427         { "arp", ETH_TYPE_ARP, 0 },
 428         { "icmp", ETH_TYPE_IP, IPPROTO_ICMP },
 429         { "tcp", ETH_TYPE_IP, IPPROTO_TCP },
 430         { "udp", ETH_TYPE_IP, IPPROTO_UDP },
 431         { "ipv6", ETH_TYPE_IPV6, 0 },
 432         { "ip6", ETH_TYPE_IPV6, 0 },
 433         { "icmp6", ETH_TYPE_IPV6, IPPROTO_ICMPV6 },
 434         { "tcp6", ETH_TYPE_IPV6, IPPROTO_TCP },
 435         { "udp6", ETH_TYPE_IPV6, IPPROTO_UDP },
 436     };
 437     const struct protocol *p;
 438
 439     for (p = protocols; p < &protocols[ARRAY_SIZE(protocols)]; p++) {
 440         if (!strcmp(p->name, name)) {
 441             *p_out = p;
 442             return true;
 443         }
 444     }
 445     *p_out = NULL;
 446     return false;
 447 }
 448
 449 static void
 450 ofp_fatal(const char *flow, bool verbose, const char *format, ...)
 451 {
 452     va_list args;
 453
 454     if (verbose) {
 455         fprintf(stderr, "%s:\n", flow);
 456     }
 457
 458     va_start(args, format);
 459     ovs_fatal_valist(0, format, args);
 460 }
 461
 462 static void
 463 parse_field(const struct mf_field *mf, const char *s, struct cls_rule *rule)
 464 {
 465     union mf_value value, mask;
 466     char *error;
 467
 468     error = mf_parse(mf, s, &value, &mask);
 469     if (error) {
 470         ovs_fatal(0, "%s", error);
 471     }
 472
 473     mf_set(mf, &value, &mask, rule);
 474 }
 475
 476 /* Convert 'str_' (as described in the Flow Syntax section of the ovs-ofctl man
 477  * page) into 'fm' for sending the specified flow_mod 'command' to a switch.
 478  * If 'actions' is specified, an action must be in 'string' and may be expanded
 479  * or reallocated.
 480  *
 481  * To parse syntax for an OFPT_FLOW_MOD (or NXT_FLOW_MOD), use an OFPFC_*
 482  * constant for 'command'.  To parse syntax for an OFPST_FLOW or
 483  * OFPST_AGGREGATE (or NXST_FLOW or NXST_AGGREGATE), use -1 for 'command'. */
 484 void
 485 parse_ofp_str(struct ofputil_flow_mod *fm, int command, const char *str_,
 486               bool verbose)
 487 {
 488     enum {
 489         F_OUT_PORT = 1 << 0,
 490         F_ACTIONS = 1 << 1,
 491         F_TIMEOUT = 1 << 3,
 492         F_PRIORITY = 1 << 4
 493     } fields;
 494     char *string = xstrdup(str_);
 495     char *save_ptr = NULL;
 496     char *act_str = NULL;
 497     char *name;
 498
 499     switch (command) {
 500     case -1:
 501         fields = F_OUT_PORT;
 502         break;
 503
 504     case OFPFC_ADD:
 505         fields = F_ACTIONS | F_TIMEOUT | F_PRIORITY;
 506         break;
 507
 508     case OFPFC_DELETE:
 509         fields = F_OUT_PORT;
 510         break;
 511
 512     case OFPFC_DELETE_STRICT:
 513         fields = F_OUT_PORT | F_PRIORITY;
 514         break;
 515
 516     case OFPFC_MODIFY:
 517         fields = F_ACTIONS;
 518         break;
 519
 520     case OFPFC_MODIFY_STRICT:
 521         fields = F_ACTIONS | F_PRIORITY;
 522         break;
 523
 524     default:
 525         NOT_REACHED();
 526     }
 527
 528     cls_rule_init_catchall(&fm->cr, OFP_DEFAULT_PRIORITY);
 529     fm->cookie = htonll(0);
 530     fm->cookie_mask = htonll(0);
 531     fm->table_id = 0xff;
 532     fm->command = command;
 533     fm->idle_timeout = OFP_FLOW_PERMANENT;
 534     fm->hard_timeout = OFP_FLOW_PERMANENT;
 535     fm->buffer_id = UINT32_MAX;
 536     fm->out_port = OFPP_NONE;
 537     fm->flags = 0;
 538     if (fields & F_ACTIONS) {
 539         act_str = strstr(string, "action");
 540         if (!act_str) {
 541             ofp_fatal(str_, verbose, "must specify an action");
 542         }
 543         *act_str = '\0';
 544
 545         act_str = strchr(act_str + 1, '=');
 546         if (!act_str) {
 547             ofp_fatal(str_, verbose, "must specify an action");
 548         }
 549
 550         act_str++;
 551     }
 552     for (name = strtok_r(string, "=, \t\r\n", &save_ptr); name;
 553          name = strtok_r(NULL, "=, \t\r\n", &save_ptr)) {
 554         const struct protocol *p;
 555
 556         if (parse_protocol(name, &p)) {
 557             cls_rule_set_dl_type(&fm->cr, htons(p->dl_type));
 558             if (p->nw_proto) {
 559                 cls_rule_set_nw_proto(&fm->cr, p->nw_proto);
 560             }
 561         } else {
 562             char *value;
 563
 564             value = strtok_r(NULL, ", \t\r\n", &save_ptr);
 565             if (!value) {
 566                 ofp_fatal(str_, verbose, "field %s missing value", name);
 567             }
 568
 569             if (!strcmp(name, "table")) {
 570                 fm->table_id = str_to_table_id(value);
 571             } else if (!strcmp(name, "out_port")) {
 572                 fm->out_port = atoi(value);
 573             } else if (fields & F_PRIORITY && !strcmp(name, "priority")) {
 574                 fm->cr.priority = str_to_u16(value, name);
 575             } else if (fields & F_TIMEOUT && !strcmp(name, "idle_timeout")) {
 576                 fm->idle_timeout = str_to_u16(value, name);
 577             } else if (fields & F_TIMEOUT && !strcmp(name, "hard_timeout")) {
 578                 fm->hard_timeout = str_to_u16(value, name);
 579             } else if (!strcmp(name, "cookie")) {
 580                 char *mask = strchr(value, '/');
 581                 if (mask) {
 582                     if (command == OFPFC_ADD) {
 583                         ofp_fatal(str_, verbose, "flow additions cannot use "
 584                                   "a cookie mask");
 585                     }
 586                     *mask = '\0';
 587                     fm->cookie_mask = htonll(str_to_u64(mask+1));
 588                 } else {
 589                     fm->cookie_mask = htonll(UINT64_MAX);
 590                 }
 591                 fm->cookie = htonll(str_to_u64(value));
 592             } else if (mf_from_name(name)) {
 593                 parse_field(mf_from_name(name), value, &fm->cr);
 594             } else if (!strcmp(name, "duration")
 595                        || !strcmp(name, "n_packets")
 596                        || !strcmp(name, "n_bytes")) {
 597                 /* Ignore these, so that users can feed the output of
 598                  * "ovs-ofctl dump-flows" back into commands that parse
 599                  * flows. */
 600             } else {
 601                 ofp_fatal(str_, verbose, "unknown keyword %s", name);
 602             }
 603         }
 604     }
 605     if (fields & F_ACTIONS) {
 606         struct ofpbuf actions;
 607
 608         ofpbuf_init(&actions, sizeof(union ofp_action));
 609         str_to_action(&fm->cr.flow, act_str, &actions);
 610         fm->actions = ofpbuf_steal_data(&actions);
 611         fm->n_actions = actions.size / sizeof(union ofp_action);
 612     } else {
 613         fm->actions = NULL;
 614         fm->n_actions = 0;
 615     }
 616
 617     free(string);
 618 }
 619
 620 /* Parses 'string' as an OFPT_FLOW_MOD or NXT_FLOW_MOD with command 'command'
 621  * (one of OFPFC_*) and appends the parsed OpenFlow message to 'packets'.
 622  * '*cur_format' should initially contain the flow format currently configured
 623  * on the connection; this function will add a message to change the flow
 624  * format and update '*cur_format', if this is necessary to add the parsed
 625  * flow. */
 626 void
 627 parse_ofp_flow_mod_str(struct list *packets, enum nx_flow_format *cur_format,
 628                        bool *flow_mod_table_id, char *string, uint16_t command,
 629                        bool verbose)
 630 {
 631     enum nx_flow_format min_format, next_format;
 632     struct cls_rule rule_copy;
 633     struct ofpbuf *ofm;
 634     struct ofputil_flow_mod fm;
 635
 636     parse_ofp_str(&fm, command, string, verbose);
 637
 638     min_format = ofputil_min_flow_format(&fm.cr);
 639     if (command != OFPFC_ADD && fm.cookie_mask != htonll(0)) {
 640         min_format = NXFF_NXM;
 641     }
 642     next_format = MAX(*cur_format, min_format);
 643     if (next_format != *cur_format) {
 644         struct ofpbuf *sff = ofputil_make_set_flow_format(next_format);
 645         list_push_back(packets, &sff->list_node);
 646         *cur_format = next_format;
 647     }
 648
 649     /* Normalize a copy of the rule.  This ensures that non-normalized flows
 650      * get logged but doesn't affect what gets sent to the switch, so that the
 651      * switch can do whatever it likes with the flow. */
 652     rule_copy = fm.cr;
 653     ofputil_normalize_rule(&rule_copy, next_format);
 654
 655     if (fm.table_id != 0xff && !*flow_mod_table_id) {
 656         struct ofpbuf *sff = ofputil_make_flow_mod_table_id(true);
 657         list_push_back(packets, &sff->list_node);
 658         *flow_mod_table_id = true;
 659     }
 660
 661     ofm = ofputil_encode_flow_mod(&fm, *cur_format, *flow_mod_table_id);
 662     list_push_back(packets, &ofm->list_node);
 663 }
 664
 665 /* Similar to parse_ofp_flow_mod_str(), except that the string is read from
 666  * 'stream' and the command is always OFPFC_ADD.  Returns false if end-of-file
 667  * is reached before reading a flow, otherwise true. */
 668 bool
 669 parse_ofp_flow_mod_file(struct list *packets,
 670                         enum nx_flow_format *cur, bool *flow_mod_table_id,
 671                         FILE *stream, uint16_t command)
 672 {
 673     struct ds s;
 674     bool ok;
 675
 676     ds_init(&s);
 677     ok = ds_get_preprocessed_line(&s, stream) == 0;
 678     if (ok) {
 679         parse_ofp_flow_mod_str(packets, cur, flow_mod_table_id,
 680                                ds_cstr(&s), command, true);
 681     }
 682     ds_destroy(&s);
 683
 684     return ok;
 685 }
 686
 687 void
 688 parse_ofp_flow_stats_request_str(struct ofputil_flow_stats_request *fsr,
 689                                  bool aggregate, char *string)
 690 {
 691     struct ofputil_flow_mod fm;
 692
 693     parse_ofp_str(&fm, -1, string, false);
 694     fsr->aggregate = aggregate;
 695     fsr->cookie = fm.cookie;
 696     fsr->cookie_mask = fm.cookie_mask;
 697     fsr->match = fm.cr;
 698     fsr->out_port = fm.out_port;
 699     fsr->table_id = fm.table_id;
 700 }