2 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 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.
21 #include <sys/types.h>
25 #include "netlink-protocol.h"
28 #include "unaligned.h"
31 VLOG_DEFINE_THIS_MODULE(netlink);
33 /* A single (bad) Netlink message can in theory dump out many, many log
34 * messages, so the burst size is set quite high here to avoid missing useful
35 * information. Also, at high logging levels we log *all* Netlink messages. */
36 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(60, 600);
38 /* Returns the nlmsghdr at the head of 'msg'.
40 * 'msg' must be at least as large as a nlmsghdr. */
42 nl_msg_nlmsghdr(const struct ofpbuf *msg)
44 return ofpbuf_at_assert(msg, 0, NLMSG_HDRLEN);
47 /* Returns the genlmsghdr just past 'msg''s nlmsghdr.
49 * Returns a null pointer if 'msg' is not large enough to contain an nlmsghdr
50 * and a genlmsghdr. */
52 nl_msg_genlmsghdr(const struct ofpbuf *msg)
54 return ofpbuf_at(msg, NLMSG_HDRLEN, GENL_HDRLEN);
57 /* If 'buffer' is a NLMSG_ERROR message, stores 0 in '*errorp' if it is an ACK
58 * message, otherwise a positive errno value, and returns true. If 'buffer' is
59 * not an NLMSG_ERROR message, returns false.
61 * 'msg' must be at least as large as a nlmsghdr. */
63 nl_msg_nlmsgerr(const struct ofpbuf *msg, int *errorp)
65 if (nl_msg_nlmsghdr(msg)->nlmsg_type == NLMSG_ERROR) {
66 struct nlmsgerr *err = ofpbuf_at(msg, NLMSG_HDRLEN, sizeof *err);
69 VLOG_ERR_RL(&rl, "received invalid nlmsgerr (%"PRIu32"d bytes < %"PRIuSIZE"d)",
70 ofpbuf_size(msg), NLMSG_HDRLEN + sizeof *err);
71 } else if (err->error <= 0 && err->error > INT_MIN) {
83 /* Ensures that 'b' has room for at least 'size' bytes plus netlink padding at
84 * its tail end, reallocating and copying its data if necessary. */
86 nl_msg_reserve(struct ofpbuf *msg, size_t size)
88 ofpbuf_prealloc_tailroom(msg, NLMSG_ALIGN(size));
91 /* Puts a nlmsghdr at the beginning of 'msg', which must be initially empty.
92 * Uses the given 'type' and 'flags'. 'expected_payload' should be
93 * an estimate of the number of payload bytes to be supplied; if the size of
94 * the payload is unknown a value of 0 is acceptable.
96 * 'type' is ordinarily an enumerated value specific to the Netlink protocol
97 * (e.g. RTM_NEWLINK, for NETLINK_ROUTE protocol). For Generic Netlink, 'type'
98 * is the family number obtained via nl_lookup_genl_family().
100 * 'flags' is a bit-mask that indicates what kind of request is being made. It
101 * is often NLM_F_REQUEST indicating that a request is being made, commonly
102 * or'd with NLM_F_ACK to request an acknowledgement.
104 * Sets the new nlmsghdr's nlmsg_len, nlmsg_seq, and nlmsg_pid fields to 0 for
105 * now. Functions that send Netlink messages will fill these in just before
106 * sending the message.
108 * nl_msg_put_genlmsghdr() is more convenient for composing a Generic Netlink
111 nl_msg_put_nlmsghdr(struct ofpbuf *msg,
112 size_t expected_payload, uint32_t type, uint32_t flags)
114 struct nlmsghdr *nlmsghdr;
116 ovs_assert(ofpbuf_size(msg) == 0);
118 nl_msg_reserve(msg, NLMSG_HDRLEN + expected_payload);
119 nlmsghdr = nl_msg_put_uninit(msg, NLMSG_HDRLEN);
120 nlmsghdr->nlmsg_len = 0;
121 nlmsghdr->nlmsg_type = type;
122 nlmsghdr->nlmsg_flags = flags;
123 nlmsghdr->nlmsg_seq = 0;
124 nlmsghdr->nlmsg_pid = 0;
127 /* Puts a nlmsghdr and genlmsghdr at the beginning of 'msg', which must be
128 * initially empty. 'expected_payload' should be an estimate of the number of
129 * payload bytes to be supplied; if the size of the payload is unknown a value
130 * of 0 is acceptable.
132 * 'family' is the family number obtained via nl_lookup_genl_family().
134 * 'flags' is a bit-mask that indicates what kind of request is being made. It
135 * is often NLM_F_REQUEST indicating that a request is being made, commonly
136 * or'd with NLM_F_ACK to request an acknowledgement.
138 * 'cmd' is an enumerated value specific to the Generic Netlink family
139 * (e.g. CTRL_CMD_NEWFAMILY for the GENL_ID_CTRL family).
141 * 'version' is a version number specific to the family and command (often 1).
143 * Sets the new nlmsghdr's nlmsg_pid field to 0 for now. nl_sock_send() will
144 * fill it in just before sending the message.
146 * nl_msg_put_nlmsghdr() should be used to compose Netlink messages that are
147 * not Generic Netlink messages. */
149 nl_msg_put_genlmsghdr(struct ofpbuf *msg, size_t expected_payload,
150 int family, uint32_t flags, uint8_t cmd, uint8_t version)
152 struct genlmsghdr *genlmsghdr;
154 nl_msg_put_nlmsghdr(msg, GENL_HDRLEN + expected_payload, family, flags);
155 ovs_assert(ofpbuf_size(msg) == NLMSG_HDRLEN);
156 genlmsghdr = nl_msg_put_uninit(msg, GENL_HDRLEN);
157 genlmsghdr->cmd = cmd;
158 genlmsghdr->version = version;
159 genlmsghdr->reserved = 0;
162 /* Appends the 'size' bytes of data in 'p', plus Netlink padding if needed, to
163 * the tail end of 'msg'. Data in 'msg' is reallocated and copied if
166 nl_msg_put(struct ofpbuf *msg, const void *data, size_t size)
168 memcpy(nl_msg_put_uninit(msg, size), data, size);
171 /* Appends 'size' bytes of data, plus Netlink padding if needed, to the tail
172 * end of 'msg', reallocating and copying its data if necessary. Returns a
173 * pointer to the first byte of the new data, which is left uninitialized. */
175 nl_msg_put_uninit(struct ofpbuf *msg, size_t size)
177 size_t pad = PAD_SIZE(size, NLMSG_ALIGNTO);
178 char *p = ofpbuf_put_uninit(msg, size + pad);
180 memset(p + size, 0, pad);
185 /* Prepends the 'size' bytes of data in 'p', plus Netlink padding if needed, to
186 * the head end of 'msg'. Data in 'msg' is reallocated and copied if
189 nl_msg_push(struct ofpbuf *msg, const void *data, size_t size)
191 memcpy(nl_msg_push_uninit(msg, size), data, size);
194 /* Prepends 'size' bytes of data, plus Netlink padding if needed, to the head
195 * end of 'msg', reallocating and copying its data if necessary. Returns a
196 * pointer to the first byte of the new data, which is left uninitialized. */
198 nl_msg_push_uninit(struct ofpbuf *msg, size_t size)
200 size_t pad = PAD_SIZE(size, NLMSG_ALIGNTO);
201 char *p = ofpbuf_push_uninit(msg, size + pad);
203 memset(p + size, 0, pad);
208 /* Appends a Netlink attribute of the given 'type' and room for 'size' bytes of
209 * data as its payload, plus Netlink padding if needed, to the tail end of
210 * 'msg', reallocating and copying its data if necessary. Returns a pointer to
211 * the first byte of data in the attribute, which is left uninitialized. */
213 nl_msg_put_unspec_uninit(struct ofpbuf *msg, uint16_t type, size_t size)
215 size_t total_size = NLA_HDRLEN + size;
216 struct nlattr* nla = nl_msg_put_uninit(msg, total_size);
217 ovs_assert(NLA_ALIGN(total_size) <= UINT16_MAX);
218 nla->nla_len = total_size;
219 nla->nla_type = type;
223 /* Appends a Netlink attribute of the given 'type' and room for 'size' bytes of
224 * data as its payload, plus Netlink padding if needed, to the tail end of
225 * 'msg', reallocating and copying its data if necessary. Returns a pointer to
226 * the first byte of data in the attribute, which is zeroed. */
228 nl_msg_put_unspec_zero(struct ofpbuf *msg, uint16_t type, size_t size)
230 void *data = nl_msg_put_unspec_uninit(msg, type, size);
231 memset(data, 0, size);
235 /* Appends a Netlink attribute of the given 'type' and the 'size' bytes of
236 * 'data' as its payload, to the tail end of 'msg', reallocating and copying
237 * its data if necessary. Returns a pointer to the first byte of data in the
238 * attribute, which is left uninitialized. */
240 nl_msg_put_unspec(struct ofpbuf *msg, uint16_t type,
241 const void *data, size_t size)
243 memcpy(nl_msg_put_unspec_uninit(msg, type, size), data, size);
246 /* Appends a Netlink attribute of the given 'type' and no payload to 'msg'.
247 * (Some Netlink protocols use the presence or absence of an attribute as a
250 nl_msg_put_flag(struct ofpbuf *msg, uint16_t type)
252 nl_msg_put_unspec(msg, type, NULL, 0);
255 /* Appends a Netlink attribute of the given 'type' and the given 8-bit 'value'
258 nl_msg_put_u8(struct ofpbuf *msg, uint16_t type, uint8_t value)
260 nl_msg_put_unspec(msg, type, &value, sizeof value);
263 /* Appends a Netlink attribute of the given 'type' and the given 16-bit host
264 * byte order 'value' to 'msg'. */
266 nl_msg_put_u16(struct ofpbuf *msg, uint16_t type, uint16_t value)
268 nl_msg_put_unspec(msg, type, &value, sizeof value);
271 /* Appends a Netlink attribute of the given 'type' and the given 32-bit host
272 * byte order 'value' to 'msg'. */
274 nl_msg_put_u32(struct ofpbuf *msg, uint16_t type, uint32_t value)
276 nl_msg_put_unspec(msg, type, &value, sizeof value);
279 /* Appends a Netlink attribute of the given 'type' and the given 64-bit host
280 * byte order 'value' to 'msg'. */
282 nl_msg_put_u64(struct ofpbuf *msg, uint16_t type, uint64_t value)
284 nl_msg_put_unspec(msg, type, &value, sizeof value);
287 /* Appends a Netlink attribute of the given 'type' and the given 16-bit network
288 * byte order 'value' to 'msg'. */
290 nl_msg_put_be16(struct ofpbuf *msg, uint16_t type, ovs_be16 value)
292 nl_msg_put_unspec(msg, type, &value, sizeof value);
295 /* Appends a Netlink attribute of the given 'type' and the given 32-bit network
296 * byte order 'value' to 'msg'. */
298 nl_msg_put_be32(struct ofpbuf *msg, uint16_t type, ovs_be32 value)
300 nl_msg_put_unspec(msg, type, &value, sizeof value);
303 /* Appends a Netlink attribute of the given 'type' and the given 64-bit network
304 * byte order 'value' to 'msg'. */
306 nl_msg_put_be64(struct ofpbuf *msg, uint16_t type, ovs_be64 value)
308 nl_msg_put_unspec(msg, type, &value, sizeof value);
311 /* Appends a Netlink attribute of the given 'type' and the given odp_port_t
312 * 'value' to 'msg'. */
314 nl_msg_put_odp_port(struct ofpbuf *msg, uint16_t type, odp_port_t value)
316 nl_msg_put_u32(msg, type, odp_to_u32(value));
320 /* Appends a Netlink attribute of the given 'type' and the given
321 * null-terminated string 'value' to 'msg'. */
323 nl_msg_put_string(struct ofpbuf *msg, uint16_t type, const char *value)
325 nl_msg_put_unspec(msg, type, value, strlen(value) + 1);
328 /* Prepends a Netlink attribute of the given 'type' and room for 'size' bytes
329 * of data as its payload, plus Netlink padding if needed, to the head end of
330 * 'msg', reallocating and copying its data if necessary. Returns a pointer to
331 * the first byte of data in the attribute, which is left uninitialized. */
333 nl_msg_push_unspec_uninit(struct ofpbuf *msg, uint16_t type, size_t size)
335 size_t total_size = NLA_HDRLEN + size;
336 struct nlattr* nla = nl_msg_push_uninit(msg, total_size);
337 ovs_assert(!nl_attr_oversized(size));
338 nla->nla_len = total_size;
339 nla->nla_type = type;
343 /* Prepends a Netlink attribute of the given 'type' and the 'size' bytes of
344 * 'data' as its payload, to the head end of 'msg', reallocating and copying
345 * its data if necessary. Returns a pointer to the first byte of data in the
346 * attribute, which is left uninitialized. */
348 nl_msg_push_unspec(struct ofpbuf *msg, uint16_t type,
349 const void *data, size_t size)
351 memcpy(nl_msg_push_unspec_uninit(msg, type, size), data, size);
354 /* Prepends a Netlink attribute of the given 'type' and no payload to 'msg'.
355 * (Some Netlink protocols use the presence or absence of an attribute as a
358 nl_msg_push_flag(struct ofpbuf *msg, uint16_t type)
360 nl_msg_push_unspec(msg, type, NULL, 0);
363 /* Prepends a Netlink attribute of the given 'type' and the given 8-bit 'value'
366 nl_msg_push_u8(struct ofpbuf *msg, uint16_t type, uint8_t value)
368 nl_msg_push_unspec(msg, type, &value, sizeof value);
371 /* Prepends a Netlink attribute of the given 'type' and the given 16-bit host
372 * byte order 'value' to 'msg'. */
374 nl_msg_push_u16(struct ofpbuf *msg, uint16_t type, uint16_t value)
376 nl_msg_push_unspec(msg, type, &value, sizeof value);
379 /* Prepends a Netlink attribute of the given 'type' and the given 32-bit host
380 * byte order 'value' to 'msg'. */
382 nl_msg_push_u32(struct ofpbuf *msg, uint16_t type, uint32_t value)
384 nl_msg_push_unspec(msg, type, &value, sizeof value);
387 /* Prepends a Netlink attribute of the given 'type' and the given 64-bit host
388 * byte order 'value' to 'msg'. */
390 nl_msg_push_u64(struct ofpbuf *msg, uint16_t type, uint64_t value)
392 nl_msg_push_unspec(msg, type, &value, sizeof value);
395 /* Prepends a Netlink attribute of the given 'type' and the given 16-bit
396 * network byte order 'value' to 'msg'. */
398 nl_msg_push_be16(struct ofpbuf *msg, uint16_t type, ovs_be16 value)
400 nl_msg_push_unspec(msg, type, &value, sizeof value);
403 /* Prepends a Netlink attribute of the given 'type' and the given 32-bit
404 * network byte order 'value' to 'msg'. */
406 nl_msg_push_be32(struct ofpbuf *msg, uint16_t type, ovs_be32 value)
408 nl_msg_push_unspec(msg, type, &value, sizeof value);
411 /* Prepends a Netlink attribute of the given 'type' and the given 64-bit
412 * network byte order 'value' to 'msg'. */
414 nl_msg_push_be64(struct ofpbuf *msg, uint16_t type, ovs_be64 value)
416 nl_msg_push_unspec(msg, type, &value, sizeof value);
419 /* Prepends a Netlink attribute of the given 'type' and the given
420 * null-terminated string 'value' to 'msg'. */
422 nl_msg_push_string(struct ofpbuf *msg, uint16_t type, const char *value)
424 nl_msg_push_unspec(msg, type, value, strlen(value) + 1);
427 /* Adds the header for nested Netlink attributes to 'msg', with the specified
428 * 'type', and returns the header's offset within 'msg'. The caller should add
429 * the content for the nested Netlink attribute to 'msg' (e.g. using the other
430 * nl_msg_*() functions), and then pass the returned offset to
431 * nl_msg_end_nested() to finish up the nested attributes. */
433 nl_msg_start_nested(struct ofpbuf *msg, uint16_t type)
435 size_t offset = ofpbuf_size(msg);
436 nl_msg_put_unspec(msg, type, NULL, 0);
440 /* Finalizes a nested Netlink attribute in 'msg'. 'offset' should be the value
441 * returned by nl_msg_start_nested(). */
443 nl_msg_end_nested(struct ofpbuf *msg, size_t offset)
445 struct nlattr *attr = ofpbuf_at_assert(msg, offset, sizeof *attr);
446 attr->nla_len = ofpbuf_size(msg) - offset;
449 /* Appends a nested Netlink attribute of the given 'type', with the 'size'
450 * bytes of content starting at 'data', to 'msg'. */
452 nl_msg_put_nested(struct ofpbuf *msg,
453 uint16_t type, const void *data, size_t size)
455 size_t offset = nl_msg_start_nested(msg, type);
456 nl_msg_put(msg, data, size);
457 nl_msg_end_nested(msg, offset);
460 /* If 'buffer' begins with a valid "struct nlmsghdr", pulls the header and its
461 * payload off 'buffer', stores header and payload in 'msg->data' and
462 * 'ofpbuf_size(msg)', and returns a pointer to the header.
464 * If 'buffer' does not begin with a "struct nlmsghdr" or begins with one that
465 * is invalid, returns NULL without modifying 'buffer'. */
467 nl_msg_next(struct ofpbuf *buffer, struct ofpbuf *msg)
469 if (ofpbuf_size(buffer) >= sizeof(struct nlmsghdr)) {
470 struct nlmsghdr *nlmsghdr = nl_msg_nlmsghdr(buffer);
471 size_t len = nlmsghdr->nlmsg_len;
472 if (len >= sizeof *nlmsghdr && len <= ofpbuf_size(buffer)) {
473 ofpbuf_use_const(msg, nlmsghdr, len);
474 ofpbuf_pull(buffer, len);
479 ofpbuf_set_data(msg, NULL);
480 ofpbuf_set_size(msg, 0);
484 /* Returns true if a Netlink attribute with a payload that is 'payload_size'
485 * bytes long would be oversized, that is, if it's not possible to create an
486 * nlattr of that size because its size wouldn't fit in the 16-bit nla_len
489 nl_attr_oversized(size_t payload_size)
491 return NL_ATTR_SIZE(payload_size) > UINT16_MAX;
496 /* Returns the bits of 'nla->nla_type' that are significant for determining its
499 nl_attr_type(const struct nlattr *nla)
501 return nla->nla_type & NLA_TYPE_MASK;
504 /* Returns the first byte in the payload of attribute 'nla'. */
506 nl_attr_get(const struct nlattr *nla)
508 ovs_assert(nla->nla_len >= NLA_HDRLEN);
512 /* Returns the number of bytes in the payload of attribute 'nla'. */
514 nl_attr_get_size(const struct nlattr *nla)
516 ovs_assert(nla->nla_len >= NLA_HDRLEN);
517 return nla->nla_len - NLA_HDRLEN;
520 /* Asserts that 'nla''s payload is at least 'size' bytes long, and returns the
521 * first byte of the payload. */
523 nl_attr_get_unspec(const struct nlattr *nla, size_t size)
525 ovs_assert(nla->nla_len >= NLA_HDRLEN + size);
529 /* Returns true if 'nla' is nonnull. (Some Netlink protocols use the presence
530 * or absence of an attribute as a Boolean flag.) */
532 nl_attr_get_flag(const struct nlattr *nla)
537 #define NL_ATTR_GET_AS(NLA, TYPE) \
538 (*(TYPE*) nl_attr_get_unspec(nla, sizeof(TYPE)))
540 /* Returns the 8-bit value in 'nla''s payload.
542 * Asserts that 'nla''s payload is at least 1 byte long. */
544 nl_attr_get_u8(const struct nlattr *nla)
546 return NL_ATTR_GET_AS(nla, uint8_t);
549 /* Returns the 16-bit host byte order value in 'nla''s payload.
551 * Asserts that 'nla''s payload is at least 2 bytes long. */
553 nl_attr_get_u16(const struct nlattr *nla)
555 return NL_ATTR_GET_AS(nla, uint16_t);
558 /* Returns the 32-bit host byte order value in 'nla''s payload.
560 * Asserts that 'nla''s payload is at least 4 bytes long. */
562 nl_attr_get_u32(const struct nlattr *nla)
564 return NL_ATTR_GET_AS(nla, uint32_t);
567 /* Returns the 64-bit host byte order value in 'nla''s payload.
569 * Asserts that 'nla''s payload is at least 8 bytes long. */
571 nl_attr_get_u64(const struct nlattr *nla)
573 const ovs_32aligned_u64 *x = nl_attr_get_unspec(nla, sizeof *x);
574 return get_32aligned_u64(x);
577 /* Returns the 16-bit network byte order value in 'nla''s payload.
579 * Asserts that 'nla''s payload is at least 2 bytes long. */
581 nl_attr_get_be16(const struct nlattr *nla)
583 return NL_ATTR_GET_AS(nla, ovs_be16);
586 /* Returns the 32-bit network byte order value in 'nla''s payload.
588 * Asserts that 'nla''s payload is at least 4 bytes long. */
590 nl_attr_get_be32(const struct nlattr *nla)
592 return NL_ATTR_GET_AS(nla, ovs_be32);
595 /* Returns the 64-bit network byte order value in 'nla''s payload.
597 * Asserts that 'nla''s payload is at least 8 bytes long. */
599 nl_attr_get_be64(const struct nlattr *nla)
601 const ovs_32aligned_be64 *x = nl_attr_get_unspec(nla, sizeof *x);
602 return get_32aligned_be64(x);
605 /* Returns the 32-bit odp_port_t value in 'nla''s payload.
607 * Asserts that 'nla''s payload is at least 4 bytes long. */
609 nl_attr_get_odp_port(const struct nlattr *nla)
611 return u32_to_odp(nl_attr_get_u32(nla));
614 /* Returns the null-terminated string value in 'nla''s payload.
616 * Asserts that 'nla''s payload contains a null-terminated string. */
618 nl_attr_get_string(const struct nlattr *nla)
620 ovs_assert(nla->nla_len > NLA_HDRLEN);
621 ovs_assert(memchr(nl_attr_get(nla), '\0', nla->nla_len - NLA_HDRLEN));
622 return nl_attr_get(nla);
625 /* Initializes 'nested' to the payload of 'nla'. */
627 nl_attr_get_nested(const struct nlattr *nla, struct ofpbuf *nested)
629 ofpbuf_use_const(nested, nl_attr_get(nla), nl_attr_get_size(nla));
632 /* Default minimum payload size for each type of attribute. */
634 min_attr_len(enum nl_attr_type type)
637 case NL_A_NO_ATTR: return 0;
638 case NL_A_UNSPEC: return 0;
639 case NL_A_U8: return 1;
640 case NL_A_U16: return 2;
641 case NL_A_U32: return 4;
642 case NL_A_U64: return 8;
643 case NL_A_STRING: return 1;
644 case NL_A_FLAG: return 0;
645 case NL_A_NESTED: return 0;
646 case N_NL_ATTR_TYPES: default: OVS_NOT_REACHED();
650 /* Default maximum payload size for each type of attribute. */
652 max_attr_len(enum nl_attr_type type)
655 case NL_A_NO_ATTR: return SIZE_MAX;
656 case NL_A_UNSPEC: return SIZE_MAX;
657 case NL_A_U8: return 1;
658 case NL_A_U16: return 2;
659 case NL_A_U32: return 4;
660 case NL_A_U64: return 8;
661 case NL_A_STRING: return SIZE_MAX;
662 case NL_A_FLAG: return SIZE_MAX;
663 case NL_A_NESTED: return SIZE_MAX;
664 case N_NL_ATTR_TYPES: default: OVS_NOT_REACHED();
669 nl_attr_validate(const struct nlattr *nla, const struct nl_policy *policy)
671 uint16_t type = nl_attr_type(nla);
676 if (policy->type == NL_A_NO_ATTR) {
680 /* Figure out min and max length. */
681 min_len = policy->min_len;
683 min_len = min_attr_len(policy->type);
685 max_len = policy->max_len;
687 max_len = max_attr_len(policy->type);
691 len = nl_attr_get_size(nla);
692 if (len < min_len || len > max_len) {
693 VLOG_DBG_RL(&rl, "attr %"PRIu16" length %"PRIuSIZE" not in "
694 "allowed range %"PRIuSIZE"...%"PRIuSIZE, type, len, min_len, max_len);
698 /* Strings must be null terminated and must not have embedded nulls. */
699 if (policy->type == NL_A_STRING) {
700 if (((char *) nla)[nla->nla_len - 1]) {
701 VLOG_DBG_RL(&rl, "attr %"PRIu16" lacks null at end", type);
704 if (memchr(nla + 1, '\0', len - 1) != NULL) {
705 VLOG_DBG_RL(&rl, "attr %"PRIu16" has bad length", type);
713 /* Parses the 'msg' starting at the given 'nla_offset' as a sequence of Netlink
714 * attributes. 'policy[i]', for 0 <= i < n_attrs, specifies how the attribute
715 * with nla_type == i is parsed; a pointer to attribute i is stored in
716 * attrs[i]. Returns true if successful, false on failure.
718 * If the Netlink attributes in 'msg' follow a Netlink header and a Generic
719 * Netlink header, then 'nla_offset' should be NLMSG_HDRLEN + GENL_HDRLEN. */
721 nl_policy_parse(const struct ofpbuf *msg, size_t nla_offset,
722 const struct nl_policy policy[],
723 struct nlattr *attrs[], size_t n_attrs)
729 memset(attrs, 0, n_attrs * sizeof *attrs);
731 if (ofpbuf_size(msg) < nla_offset) {
732 VLOG_DBG_RL(&rl, "missing headers in nl_policy_parse");
736 NL_ATTR_FOR_EACH (nla, left, ofpbuf_at(msg, nla_offset, 0),
737 ofpbuf_size(msg) - nla_offset)
739 uint16_t type = nl_attr_type(nla);
740 if (type < n_attrs && policy[type].type != NL_A_NO_ATTR) {
741 const struct nl_policy *e = &policy[type];
742 if (!nl_attr_validate(nla, e)) {
746 VLOG_DBG_RL(&rl, "duplicate attr %"PRIu16, type);
752 VLOG_DBG_RL(&rl, "attributes followed by garbage");
756 for (i = 0; i < n_attrs; i++) {
757 const struct nl_policy *e = &policy[i];
758 if (!e->optional && e->type != NL_A_NO_ATTR && !attrs[i]) {
759 VLOG_DBG_RL(&rl, "required attr %"PRIuSIZE" missing", i);
766 /* Parses the Netlink attributes within 'nla'. 'policy[i]', for 0 <= i <
767 * n_attrs, specifies how the attribute with nla_type == i is parsed; a pointer
768 * to attribute i is stored in attrs[i]. Returns true if successful, false on
771 nl_parse_nested(const struct nlattr *nla, const struct nl_policy policy[],
772 struct nlattr *attrs[], size_t n_attrs)
776 nl_attr_get_nested(nla, &buf);
777 return nl_policy_parse(&buf, 0, policy, attrs, n_attrs);
780 const struct nlattr *
781 nl_attr_find__(const struct nlattr *attrs, size_t size, uint16_t type)
783 const struct nlattr *nla;
786 NL_ATTR_FOR_EACH (nla, left, attrs, size) {
787 if (nl_attr_type(nla) == type) {
794 /* Returns the first Netlink attribute within 'buf' with the specified 'type',
795 * skipping a header of 'hdr_len' bytes at the beginning of 'buf'.
797 * This function does not validate the attribute's length. */
798 const struct nlattr *
799 nl_attr_find(const struct ofpbuf *buf, size_t hdr_len, uint16_t type)
801 return nl_attr_find__(ofpbuf_at(buf, hdr_len, 0), ofpbuf_size(buf) - hdr_len,
805 /* Returns the first Netlink attribute within 'nla' with the specified
808 * This function does not validate the attribute's length. */
809 const struct nlattr *
810 nl_attr_find_nested(const struct nlattr *nla, uint16_t type)
812 return nl_attr_find__(nl_attr_get(nla), nl_attr_get_size(nla), type);