2 * Copyright (c) 2012 Nicira, Inc.
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:
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
20 #include "byte-order.h"
21 #include "dynamic-string.h"
25 #include "openflow/nicira-ext.h"
26 #include "openflow/openflow.h"
29 VLOG_DEFINE_THIS_MODULE(ofp_msgs);
32 #define OFPT10_STATS_REQUEST 16
33 #define OFPT10_STATS_REPLY 17
34 #define OFPT11_STATS_REQUEST 18
35 #define OFPT11_STATS_REPLY 19
36 #define OFPST_VENDOR 0xffff
38 /* A thin abstraction of OpenFlow headers:
40 * - 'version' and 'type' come straight from struct ofp_header, so these are
41 * always present and meaningful.
43 * - 'stat' comes from the 'type' member in statistics messages only. It is
44 * meaningful, therefore, only if 'version' and 'type' taken together
45 * specify a statistics request or reply. Otherwise it is 0.
47 * - 'vendor' is meaningful only for vendor messages, that is, if 'version'
48 * and 'type' specify a vendor message or if 'version' and 'type' specify
49 * a statistics message and 'stat' specifies a vendor statistic type.
52 * - 'subtype' is meaningful only for vendor messages and otherwise 0. It
53 * specifies a vendor-defined subtype. There is no standard format for
54 * these but 32 bits seems like it should be enough. */
56 uint8_t version; /* From ofp_header. */
57 uint8_t type; /* From ofp_header. */
58 uint16_t stat; /* From ofp10_stats_msg or ofp11_stats_msg. */
59 uint32_t vendor; /* From ofp_vendor_header,
60 * ofp10_vendor_stats_msg, or
61 * ofp11_vendor_stats_msg. */
62 uint32_t subtype; /* From nicira_header, nicira10_stats_msg, or
63 * nicira11_stats_msg. */
65 BUILD_ASSERT_DECL(sizeof(struct ofphdrs) == 12);
67 /* A mapping from OpenFlow headers to OFPRAW_*. */
69 struct hmap_node hmap_node; /* In 'raw_instance_map'. */
70 struct ofphdrs hdrs; /* Key. */
71 enum ofpraw raw; /* Value. */
72 unsigned int hdrs_len; /* ofphdrs_len(hdrs). */
75 /* Information about a particular 'enum ofpraw'. */
77 /* All possible instantiations of this OFPRAW_* into OpenFlow headers. */
78 struct raw_instance *instances; /* min_version - max_version + 1 elems. */
82 unsigned int min_body;
83 unsigned int extra_multiple;
88 /* All understood OpenFlow message types, indexed by their 'struct ofphdrs'. */
89 static struct hmap raw_instance_map;
90 #include "ofp-msgs.inc"
92 static ovs_be32 alloc_xid(void);
94 /* ofphdrs functions. */
95 static uint32_t ofphdrs_hash(const struct ofphdrs *);
96 static bool ofphdrs_equal(const struct ofphdrs *a, const struct ofphdrs *b);
97 static enum ofperr ofphdrs_decode(struct ofphdrs *,
98 const struct ofp_header *oh, size_t length);
99 static void ofphdrs_decode_assert(struct ofphdrs *,
100 const struct ofp_header *oh, size_t length);
101 size_t ofphdrs_len(const struct ofphdrs *);
103 static const struct raw_info *raw_info_get(enum ofpraw);
104 static struct raw_instance *raw_instance_get(const struct raw_info *,
107 static enum ofperr ofpraw_from_ofphdrs(enum ofpraw *, const struct ofphdrs *);
109 /* Returns a transaction ID to use for an outgoing OpenFlow message. */
113 static uint32_t next_xid = 1;
114 return htonl(next_xid++);
118 ofphdrs_hash(const struct ofphdrs *hdrs)
120 BUILD_ASSERT_DECL(sizeof *hdrs == 12);
121 return hash_words((const uint32_t *) hdrs, 3, 0);
125 ofphdrs_equal(const struct ofphdrs *a, const struct ofphdrs *b)
127 return !memcmp(a, b, sizeof *a);
131 log_bad_vendor(uint32_t vendor)
133 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
135 VLOG_WARN_RL(&rl, "OpenFlow message has unknown vendor %#"PRIx32, vendor);
139 ofphdrs_decode(struct ofphdrs *hdrs,
140 const struct ofp_header *oh, size_t length)
142 memset(hdrs, 0, sizeof *hdrs);
143 if (length < sizeof *oh) {
144 return OFPERR_OFPBRC_BAD_LEN;
147 /* Get base message version and type (OFPT_*). */
148 hdrs->version = oh->version;
149 hdrs->type = oh->type;
151 if (hdrs->type == OFPT_VENDOR) {
153 const struct ofp_vendor_header *ovh;
155 if (length < sizeof *ovh) {
156 return OFPERR_OFPBRC_BAD_LEN;
159 ovh = (const struct ofp_vendor_header *) oh;
160 hdrs->vendor = ntohl(ovh->vendor);
161 if (hdrs->vendor == NX_VENDOR_ID) {
162 /* Get Nicira message subtype (NXT_*). */
163 const struct nicira_header *nh;
165 if (length < sizeof *nh) {
166 return OFPERR_OFPBRC_BAD_LEN;
168 nh = (const struct nicira_header *) oh;
169 hdrs->subtype = ntohl(nh->subtype);
171 log_bad_vendor(hdrs->vendor);
172 return OFPERR_OFPBRC_BAD_VENDOR;
174 } else if (hdrs->version == OFP10_VERSION
175 && (hdrs->type == OFPT10_STATS_REQUEST ||
176 hdrs->type == OFPT10_STATS_REPLY)) {
177 const struct ofp10_stats_msg *osm;
179 /* Get statistic type (OFPST_*). */
180 if (length < sizeof *osm) {
181 return OFPERR_OFPBRC_BAD_LEN;
183 osm = (const struct ofp10_stats_msg *) oh;
184 hdrs->stat = ntohs(osm->type);
186 if (hdrs->stat == OFPST_VENDOR) {
188 const struct ofp10_vendor_stats_msg *ovsm;
190 if (length < sizeof *ovsm) {
191 return OFPERR_OFPBRC_BAD_LEN;
194 ovsm = (const struct ofp10_vendor_stats_msg *) oh;
195 hdrs->vendor = ntohl(ovsm->vendor);
196 if (hdrs->vendor == NX_VENDOR_ID) {
197 /* Get Nicira statistic type (NXST_*). */
198 const struct nicira10_stats_msg *nsm;
200 if (length < sizeof *nsm) {
201 return OFPERR_OFPBRC_BAD_LEN;
203 nsm = (const struct nicira10_stats_msg *) oh;
204 hdrs->subtype = ntohl(nsm->subtype);
206 log_bad_vendor(hdrs->vendor);
207 return OFPERR_OFPBRC_BAD_VENDOR;
210 } else if (hdrs->version != OFP10_VERSION
211 && (hdrs->type == OFPT11_STATS_REQUEST ||
212 hdrs->type == OFPT11_STATS_REPLY)) {
213 const struct ofp11_stats_msg *osm;
215 /* Get statistic type (OFPST_*). */
216 if (length < sizeof *osm) {
217 return OFPERR_OFPBRC_BAD_LEN;
219 osm = (const struct ofp11_stats_msg *) oh;
220 hdrs->stat = ntohs(osm->type);
222 if (hdrs->stat == OFPST_VENDOR) {
224 const struct ofp11_vendor_stats_msg *ovsm;
226 if (length < sizeof *ovsm) {
227 return OFPERR_OFPBRC_BAD_LEN;
230 ovsm = (const struct ofp11_vendor_stats_msg *) oh;
231 hdrs->vendor = ntohl(ovsm->vendor);
232 if (hdrs->vendor == NX_VENDOR_ID) {
233 /* Get Nicira statistic type (NXST_*). */
234 const struct nicira11_stats_msg *nsm;
236 if (length < sizeof *nsm) {
237 return OFPERR_OFPBRC_BAD_LEN;
239 nsm = (const struct nicira11_stats_msg *) oh;
240 hdrs->subtype = ntohl(nsm->subtype);
242 log_bad_vendor(hdrs->vendor);
243 return OFPERR_OFPBRC_BAD_VENDOR;
252 ofphdrs_decode_assert(struct ofphdrs *hdrs,
253 const struct ofp_header *oh, size_t length)
255 enum ofperr error = ofphdrs_decode(hdrs, oh, length);
260 ofphdrs_is_stat(const struct ofphdrs *hdrs)
262 switch ((enum ofp_version) hdrs->version) {
264 return (hdrs->type == OFPT10_STATS_REQUEST ||
265 hdrs->type == OFPT10_STATS_REPLY);
269 return (hdrs->type == OFPT11_STATS_REQUEST ||
270 hdrs->type == OFPT11_STATS_REPLY);
277 ofphdrs_len(const struct ofphdrs *hdrs)
279 if (hdrs->type == OFPT_VENDOR) {
280 return sizeof(struct nicira_header);
283 switch ((enum ofp_version) hdrs->version) {
285 if (hdrs->type == OFPT10_STATS_REQUEST ||
286 hdrs->type == OFPT10_STATS_REPLY) {
287 return (hdrs->stat == OFPST_VENDOR
288 ? sizeof(struct nicira10_stats_msg)
289 : sizeof(struct ofp10_stats_msg));
296 if (hdrs->type == OFPT11_STATS_REQUEST ||
297 hdrs->type == OFPT11_STATS_REPLY) {
298 return (hdrs->stat == OFPST_VENDOR
299 ? sizeof(struct nicira11_stats_msg)
300 : sizeof(struct ofp11_stats_msg));
305 return sizeof(struct ofp_header);
308 /* Determines the OFPRAW_* type of the OpenFlow message at 'oh', which has
309 * length 'oh->length'. (The caller must ensure that 'oh->length' bytes of
310 * data are readable at 'oh'.) On success, returns 0 and stores the type into
311 * '*raw'. On failure, returns an OFPERR_* error code and zeros '*raw'.
313 * This function checks that 'oh' is a valid length for its particular type of
314 * message, and returns an error if not. */
316 ofpraw_decode(enum ofpraw *raw, const struct ofp_header *oh)
320 ofpbuf_use_const(&msg, oh, ntohs(oh->length));
321 return ofpraw_pull(raw, &msg);
324 /* Determines the OFPRAW_* type of the OpenFlow message in 'msg', which starts
325 * at 'msg->data' and has length 'msg->size' bytes. On success, returns 0 and
326 * stores the type into '*rawp'. On failure, returns an OFPERR_* error code
329 * This function checks that the message has a valid length for its particular
330 * type of message, and returns an error if not.
332 * In addition to setting '*rawp', this function pulls off the OpenFlow header
333 * (including the stats headers, vendor header, and any subtype header) with
334 * ofpbuf_pull(). It also sets 'msg->l2' to the start of the OpenFlow header
335 * and 'msg->l3' just beyond the headers (that is, to the final value of
338 ofpraw_pull(enum ofpraw *rawp, struct ofpbuf *msg)
340 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
342 const struct raw_instance *instance;
343 const struct raw_info *info;
346 unsigned int min_len;
352 /* Set default outputs. */
353 msg->l2 = msg->l3 = msg->data;
357 error = ofphdrs_decode(&hdrs, msg->data, len);
362 error = ofpraw_from_ofphdrs(&raw, &hdrs);
367 info = raw_info_get(raw);
368 instance = raw_instance_get(info, hdrs.version);
369 msg->l2 = ofpbuf_pull(msg, instance->hdrs_len);
372 min_len = instance->hdrs_len + info->min_body;
373 switch (info->extra_multiple) {
375 if (len != min_len) {
376 VLOG_WARN_RL(&rl, "received %s with incorrect length %u (expected "
377 "length %u)", info->name, len, min_len);
378 return OFPERR_OFPBRC_BAD_LEN;
384 VLOG_WARN_RL(&rl, "received %s with incorrect length %u (expected "
385 "length at least %u bytes)",
386 info->name, len, min_len);
387 return OFPERR_OFPBRC_BAD_LEN;
392 if (len < min_len || (len - min_len) % info->extra_multiple) {
393 VLOG_WARN_RL(&rl, "received %s with incorrect length %u (must be "
394 "exactly %u bytes or longer by an integer multiple "
396 info->name, len, min_len, info->extra_multiple);
397 return OFPERR_OFPBRC_BAD_LEN;
406 /* Does the same job as ofpraw_pull(), except that it assert-fails if
407 * ofpbuf_pull() would have reported an error. Thus, it's able to use the
408 * return value for the OFPRAW_* message type instead of an error code.
410 * (It only makes sense to use this function if you previously called
411 * ofpbuf_decode() on the message and thus know that it's OK.) */
413 ofpraw_pull_assert(struct ofpbuf *msg)
418 error = ofpraw_pull(&raw, msg);
423 /* Determines the OFPRAW_* type of the OpenFlow message that starts at 'oh' and
424 * has length 'length' bytes. On success, returns 0 and stores the type into
425 * '*rawp'. On failure, returns an OFPERR_* error code and zeros '*rawp'.
427 * Unlike other functions for decoding message types, this one is not picky
428 * about message length. For example, it will successfully decode a message
429 * whose body is shorter than the minimum length for a message of its type.
430 * Thus, this is the correct function to use for decoding the type of a message
431 * that might have been truncated, such as the payload of an OpenFlow error
432 * message (which is allowed to be truncated to 64 bytes). */
434 ofpraw_decode_partial(enum ofpraw *raw,
435 const struct ofp_header *oh, size_t length)
440 error = ofphdrs_decode(&hdrs, oh, length);
442 error = ofpraw_from_ofphdrs(raw, &hdrs);
451 /* Encoding messages using OFPRAW_* values. */
453 static void ofpraw_put__(enum ofpraw, uint8_t version, ovs_be32 xid,
454 size_t extra_tailroom, struct ofpbuf *);
456 /* Allocates and returns a new ofpbuf that contains an OpenFlow header for
457 * 'raw' with OpenFlow version 'version' and a fresh OpenFlow transaction ID.
458 * The ofpbuf has enough tailroom for the minimum body length of 'raw', plus
459 * 'extra_tailroom' additional bytes.
461 * Each 'raw' value is valid only for certain OpenFlow versions. The caller
462 * must specify a valid (raw, version) pair.
464 * In the returned ofpbuf, 'l2' points to the beginning of the OpenFlow header
465 * and 'l3' points just after it, to where the message's body will start. The
466 * caller must actually allocate the body into the space reserved for it,
467 * e.g. with ofpbuf_put_uninit().
469 * The caller owns the returned ofpbuf and must free it when it is no longer
470 * needed, e.g. with ofpbuf_delete(). */
472 ofpraw_alloc(enum ofpraw raw, uint8_t version, size_t extra_tailroom)
474 return ofpraw_alloc_xid(raw, version, alloc_xid(), extra_tailroom);
477 /* Same as ofpraw_alloc() but the caller provides the transaction ID. */
479 ofpraw_alloc_xid(enum ofpraw raw, uint8_t version, ovs_be32 xid,
480 size_t extra_tailroom)
482 struct ofpbuf *buf = ofpbuf_new(0);
483 ofpraw_put__(raw, version, xid, extra_tailroom, buf);
487 /* Same as ofpraw_alloc(), but obtains the OpenFlow version and transaction ID
488 * from 'request->version' and 'request->xid', respectively.
490 * Even though the version comes from 'request->version', the caller must still
491 * know what it is doing, by specifying a valid pairing of 'raw' and
492 * 'request->version', just like ofpraw_alloc(). */
494 ofpraw_alloc_reply(enum ofpraw raw, const struct ofp_header *request,
495 size_t extra_tailroom)
497 return ofpraw_alloc_xid(raw, request->version, request->xid,
501 /* Allocates and returns a new ofpbuf that contains an OpenFlow header that is
502 * a stats reply to the stats request in 'request', using the same OpenFlow
503 * version and transaction ID as 'request'. The ofpbuf has enough tailroom for
504 * the stats reply's minimum body length, plus 'extra_tailroom' additional
507 * 'request' must be a stats request, that is, an OFPRAW_OFPST* or OFPRAW_NXST*
508 * value. Every stats request has a corresponding reply, so the (raw, version)
509 * pairing pitfalls of the other ofpraw_alloc_*() functions don't apply here.
511 * In the returned ofpbuf, 'l2' points to the beginning of the OpenFlow header
512 * and 'l3' points just after it, to where the message's body will start. The
513 * caller must actually allocate the body into the space reserved for it,
514 * e.g. with ofpbuf_put_uninit().
516 * The caller owns the returned ofpbuf and must free it when it is no longer
517 * needed, e.g. with ofpbuf_delete(). */
519 ofpraw_alloc_stats_reply(const struct ofp_header *request,
520 size_t extra_tailroom)
522 enum ofpraw request_raw;
523 enum ofpraw reply_raw;
526 error = ofpraw_decode_partial(&request_raw, request,
527 ntohs(request->length));
530 reply_raw = ofpraw_stats_request_to_reply(request_raw, request->version);
533 return ofpraw_alloc_reply(reply_raw, request, extra_tailroom);
536 /* Appends to 'buf' an OpenFlow header for 'raw' with OpenFlow version
537 * 'version' and a fresh OpenFlow transaction ID. Preallocates enough tailroom
538 * in 'buf' for the minimum body length of 'raw', plus 'extra_tailroom'
541 * Each 'raw' value is valid only for certain OpenFlow versions. The caller
542 * must specify a valid (raw, version) pair.
544 * Upon return, 'buf->l2' points to the beginning of the OpenFlow header and
545 * 'buf->l3' points just after it, to where the message's body will start. The
546 * caller must actually allocating the body into the space reserved for it,
547 * e.g. with ofpbuf_put_uninit(). */
549 ofpraw_put(enum ofpraw raw, uint8_t version, struct ofpbuf *buf)
551 ofpraw_put__(raw, version, alloc_xid(), 0, buf);
554 /* Same as ofpraw_put() but the caller provides the transaction ID. */
556 ofpraw_put_xid(enum ofpraw raw, uint8_t version, ovs_be32 xid,
559 ofpraw_put__(raw, version, xid, 0, buf);
562 /* Same as ofpraw_put(), but obtains the OpenFlow version and transaction ID
563 * from 'request->version' and 'request->xid', respectively.
565 * Even though the version comes from 'request->version', the caller must still
566 * know what it is doing, by specifying a valid pairing of 'raw' and
567 * 'request->version', just like ofpraw_put(). */
569 ofpraw_put_reply(enum ofpraw raw, const struct ofp_header *request,
572 ofpraw_put__(raw, request->version, request->xid, 0, buf);
575 /* Appends to 'buf' an OpenFlow header that is a stats reply to the stats
576 * request in 'request', using the same OpenFlow version and transaction ID as
577 * 'request'. Preallocate enough tailroom in 'buf for the stats reply's
578 * minimum body length, plus 'extra_tailroom' additional bytes.
580 * 'request' must be a stats request, that is, an OFPRAW_OFPST* or OFPRAW_NXST*
581 * value. Every stats request has a corresponding reply, so the (raw, version)
582 * pairing pitfalls of the other ofpraw_alloc_*() functions don't apply here.
584 * In the returned ofpbuf, 'l2' points to the beginning of the OpenFlow header
585 * and 'l3' points just after it, to where the message's body will start. The
586 * caller must actually allocate the body into the space reserved for it,
587 * e.g. with ofpbuf_put_uninit().
589 * The caller owns the returned ofpbuf and must free it when it is no longer
590 * needed, e.g. with ofpbuf_delete(). */
592 ofpraw_put_stats_reply(const struct ofp_header *request, struct ofpbuf *buf)
597 error = ofpraw_decode_partial(&raw, request, ntohs(request->length));
600 raw = ofpraw_stats_request_to_reply(raw, request->version);
603 ofpraw_put__(raw, request->version, request->xid, 0, buf);
607 ofpraw_put__(enum ofpraw raw, uint8_t version, ovs_be32 xid,
608 size_t extra_tailroom, struct ofpbuf *buf)
610 const struct raw_info *info = raw_info_get(raw);
611 const struct raw_instance *instance = raw_instance_get(info, version);
612 const struct ofphdrs *hdrs = &instance->hdrs;
613 struct ofp_header *oh;
615 ofpbuf_prealloc_tailroom(buf, (instance->hdrs_len + info->min_body
617 buf->l2 = ofpbuf_put_uninit(buf, instance->hdrs_len);
618 buf->l3 = ofpbuf_tail(buf);
621 oh->version = version;
622 oh->type = hdrs->type;
623 oh->length = htons(buf->size);
626 if (hdrs->type == OFPT_VENDOR) {
627 struct nicira_header *nh = buf->l2;
629 assert(hdrs->vendor == NX_VENDOR_ID);
630 nh->vendor = htonl(hdrs->vendor);
631 nh->subtype = htonl(hdrs->subtype);
632 } else if (version == OFP10_VERSION
633 && (hdrs->type == OFPT10_STATS_REQUEST ||
634 hdrs->type == OFPT10_STATS_REPLY)) {
635 struct ofp10_stats_msg *osm = buf->l2;
637 osm->type = htons(hdrs->stat);
638 osm->flags = htons(0);
640 if (hdrs->stat == OFPST_VENDOR) {
641 struct ofp10_vendor_stats_msg *ovsm = buf->l2;
643 ovsm->vendor = htonl(hdrs->vendor);
644 if (hdrs->vendor == NX_VENDOR_ID) {
645 struct nicira10_stats_msg *nsm = buf->l2;
647 nsm->subtype = htonl(hdrs->subtype);
648 memset(nsm->pad, 0, sizeof nsm->pad);
653 } else if (version != OFP10_VERSION
654 && (hdrs->type == OFPT11_STATS_REQUEST ||
655 hdrs->type == OFPT11_STATS_REPLY)) {
656 struct ofp11_stats_msg *osm = buf->l2;
658 osm->type = htons(hdrs->stat);
659 osm->flags = htons(0);
660 memset(osm->pad, 0, sizeof osm->pad);
662 if (hdrs->stat == OFPST_VENDOR) {
663 struct ofp11_vendor_stats_msg *ovsm = buf->l2;
665 ovsm->vendor = htonl(hdrs->vendor);
666 if (hdrs->vendor == NX_VENDOR_ID) {
667 struct nicira11_stats_msg *nsm = buf->l2;
669 nsm->subtype = htonl(hdrs->subtype);
677 /* Returns 'raw''s name.
679 * The name is the name used for 'raw' in the OpenFlow specification. For
680 * example, ofpraw_get_name(OFPRAW_OFPT10_FEATURES_REPLY) is
681 * "OFPT_FEATURES_REPLY".
683 * The caller must not modify or free the returned string. */
685 ofpraw_get_name(enum ofpraw raw)
687 return raw_info_get(raw)->name;
690 /* Returns the stats reply that corresponds to 'raw' in the given OpenFlow
693 ofpraw_stats_request_to_reply(enum ofpraw raw, uint8_t version)
695 const struct raw_info *info = raw_info_get(raw);
696 const struct raw_instance *instance = raw_instance_get(info, version);
697 enum ofpraw reply_raw;
701 hdrs = instance->hdrs;
702 switch ((enum ofp_version)hdrs.version) {
704 assert(hdrs.type == OFPT10_STATS_REQUEST);
705 hdrs.type = OFPT10_STATS_REPLY;
710 assert(hdrs.type == OFPT11_STATS_REQUEST);
711 hdrs.type = OFPT11_STATS_REPLY;
717 error = ofpraw_from_ofphdrs(&reply_raw, &hdrs);
723 /* Determines the OFPTYPE_* type of the OpenFlow message at 'oh', which has
724 * length 'oh->length'. (The caller must ensure that 'oh->length' bytes of
725 * data are readable at 'oh'.) On success, returns 0 and stores the type into
726 * '*typep'. On failure, returns an OFPERR_* error code and zeros '*typep'.
728 * This function checks that 'oh' is a valid length for its particular type of
729 * message, and returns an error if not. */
731 ofptype_decode(enum ofptype *typep, const struct ofp_header *oh)
736 error = ofpraw_decode(&raw, oh);
737 *typep = error ? 0 : ofptype_from_ofpraw(raw);
741 /* Determines the OFPTYPE_* type of the OpenFlow message in 'msg', which starts
742 * at 'msg->data' and has length 'msg->size' bytes. On success, returns 0 and
743 * stores the type into '*typep'. On failure, returns an OFPERR_* error code
744 * and zeros '*typep'.
746 * This function checks that the message has a valid length for its particular
747 * type of message, and returns an error if not.
749 * In addition to setting '*typep', this function pulls off the OpenFlow header
750 * (including the stats headers, vendor header, and any subtype header) with
751 * ofpbuf_pull(). It also sets 'msg->l2' to the start of the OpenFlow header
752 * and 'msg->l3' just beyond the headers (that is, to the final value of
755 ofptype_pull(enum ofptype *typep, struct ofpbuf *buf)
760 error = ofpraw_pull(&raw, buf);
761 *typep = error ? 0 : ofptype_from_ofpraw(raw);
765 /* Returns the OFPTYPE_* type that corresponds to 'raw'.
767 * (This is a one-way trip, because the mapping from ofpraw to ofptype is
770 ofptype_from_ofpraw(enum ofpraw raw)
772 return raw_info_get(raw)->type;
775 /* Updates the 'length' field of the OpenFlow message in 'buf' to
778 ofpmsg_update_length(struct ofpbuf *buf)
780 struct ofp_header *oh = ofpbuf_at_assert(buf, 0, sizeof *oh);
781 oh->length = htons(buf->size);
784 /* Returns just past the Openflow header (including the stats headers, vendor
785 * header, and any subtype header) in 'oh'. */
787 ofpmsg_body(const struct ofp_header *oh)
791 ofphdrs_decode_assert(&hdrs, oh, ntohs(oh->length));
792 return (const uint8_t *) oh + ofphdrs_len(&hdrs);
795 static ovs_be16 *ofpmp_flags__(const struct ofp_header *);
797 /* Initializes 'replies' as a new list of stats messages that reply to
798 * 'request', which must be a stats request message. Initially the list will
799 * consist of only a single reply part without any body. The caller should
800 * use calls to the other ofpmp_*() functions to add to the body and split the
801 * message into multiple parts, if necessary. */
803 ofpmp_init(struct list *replies, const struct ofp_header *request)
809 msg = ofpraw_alloc_stats_reply(request, 1000);
810 list_push_back(replies, &msg->list_node);
813 /* Prepares to append up to 'len' bytes to the series of statistics replies in
814 * 'replies', which should have been initialized with ofpmp_init(), if
815 * necessary adding a new reply to the list.
817 * Returns an ofpbuf with at least 'len' bytes of tailroom. The 'len' bytes
818 * have not actually been allocated, so the caller must do so with
819 * e.g. ofpbuf_put_uninit(). */
821 ofpmp_reserve(struct list *replies, size_t len)
823 struct ofpbuf *msg = ofpbuf_from_list(list_back(replies));
825 if (msg->size + len <= UINT16_MAX) {
826 ofpbuf_prealloc_tailroom(msg, len);
829 unsigned int hdrs_len;
833 ofphdrs_decode_assert(&hdrs, msg->data, msg->size);
834 hdrs_len = ofphdrs_len(&hdrs);
836 next = ofpbuf_new(MAX(1024, hdrs_len + len));
837 ofpbuf_put(next, msg->data, hdrs_len);
838 list_push_back(replies, &next->list_node);
840 *ofpmp_flags__(msg->data) |= htons(OFPSF_REPLY_MORE);
846 /* Appends 'len' bytes to the series of statistics replies in 'replies', and
847 * returns the first byte. */
849 ofpmp_append(struct list *replies, size_t len)
851 return ofpbuf_put_uninit(ofpmp_reserve(replies, len), len);
854 /* Sometimes, when composing stats replies, it's difficult to predict how long
855 * an individual reply chunk will be before actually encoding it into the reply
856 * buffer. This function allows easy handling of this case: just encode the
857 * reply, then use this function to break the message into two pieces if it
858 * exceeds the OpenFlow message limit.
860 * In detail, if the final stats message in 'replies' is too long for OpenFlow,
861 * this function breaks it into two separate stats replies, the first one with
862 * the first 'start_ofs' bytes, the second one containing the bytes from that
865 ofpmp_postappend(struct list *replies, size_t start_ofs)
867 struct ofpbuf *msg = ofpbuf_from_list(list_back(replies));
869 assert(start_ofs <= UINT16_MAX);
870 if (msg->size > UINT16_MAX) {
871 size_t len = msg->size - start_ofs;
872 memcpy(ofpmp_append(replies, len),
873 (const uint8_t *) msg->data + start_ofs, len);
874 msg->size = start_ofs;
879 ofpmp_flags__(const struct ofp_header *oh)
881 switch ((enum ofp_version)oh->version) {
883 return &((struct ofp10_stats_msg *) oh)->flags;
887 return &((struct ofp11_stats_msg *) oh)->flags;
893 /* Returns the OFPSF_* flags found in the OpenFlow stats header of 'oh', which
894 * must be an OpenFlow stats request or reply.
896 * (OFPSF_REPLY_MORE is the only defined flag.) */
898 ofpmp_flags(const struct ofp_header *oh)
900 return ntohs(*ofpmp_flags__(oh));
903 /* Returns true if the OFPSF_REPLY_MORE flag is set in the OpenFlow stats
904 * header of 'oh', which must be an OpenFlow stats request or reply, false if
907 ofpmp_more(const struct ofp_header *oh)
909 return (ofpmp_flags(oh) & OFPSF_REPLY_MORE) != 0;
912 static void ofpmsgs_init(void);
914 static const struct raw_info *
915 raw_info_get(enum ofpraw raw)
919 assert(raw < ARRAY_SIZE(raw_infos));
920 return &raw_infos[raw];
923 static struct raw_instance *
924 raw_instance_get(const struct raw_info *info, uint8_t version)
926 assert(version >= info->min_version && version <= info->max_version);
927 return &info->instances[version - info->min_version];
931 ofpraw_from_ofphdrs(enum ofpraw *raw, const struct ofphdrs *hdrs)
933 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
935 struct raw_instance *raw_hdrs;
940 hash = ofphdrs_hash(hdrs);
941 HMAP_FOR_EACH_WITH_HASH (raw_hdrs, hmap_node, hash, &raw_instance_map) {
942 if (ofphdrs_equal(hdrs, &raw_hdrs->hdrs)) {
943 *raw = raw_hdrs->raw;
948 if (!VLOG_DROP_WARN(&rl)) {
952 ds_put_format(&s, "version %"PRIu8", type %"PRIu8,
953 hdrs->version, hdrs->type);
954 if (ofphdrs_is_stat(hdrs)) {
955 ds_put_format(&s, ", stat %"PRIu16, hdrs->stat);
958 ds_put_format(&s, ", vendor 0x%"PRIx32", subtype %"PRIu32,
959 hdrs->vendor, hdrs->subtype);
961 VLOG_WARN("unknown OpenFlow message (%s)", ds_cstr(&s));
965 return (hdrs->vendor ? OFPERR_OFPBRC_BAD_SUBTYPE
966 : ofphdrs_is_stat(hdrs) ? OFPERR_OFPBRC_BAD_STAT
967 : OFPERR_OFPBRC_BAD_TYPE);
973 const struct raw_info *info;
975 if (raw_instance_map.buckets) {
979 hmap_init(&raw_instance_map);
980 for (info = raw_infos; info < &raw_infos[ARRAY_SIZE(raw_infos)]; info++)
982 int n_instances = info->max_version - info->min_version + 1;
983 struct raw_instance *inst;
985 for (inst = info->instances;
986 inst < &info->instances[n_instances];
988 inst->hdrs_len = ofphdrs_len(&inst->hdrs);
989 hmap_insert(&raw_instance_map, &inst->hmap_node,
990 ofphdrs_hash(&inst->hdrs));