4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 * All rights reserved. This program and the accompanying materials
7 * are made available under the terms of the GNU Lesser General Public License
8 * LGPL version 2.1 or (at your discretion) any later version.
9 * LGPL version 2.1 accompanies this distribution, and is available at
10 * http://www.gnu.org/licenses/lgpl-2.1.html
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
22 * Copyright (c) 2021 UT-Battelle, LLC
24 * Author: James Simmons <jsimmons@infradead.org>
32 #include <linux/lnet/lnet-nl.h>
33 #include "liblnetconfig.h"
36 #define fallthrough do {} while (0) /* fallthrough */
39 #ifndef SOL_NETLINK /* for glibc < 2.24 */
40 # define SOL_NETLINK 270
43 #ifndef NETLINK_EXT_ACK
44 #define NETLINK_EXT_ACK 11
47 #ifndef NLM_F_ACK_TLVS
48 #define NLM_F_ACK_TLVS 0x200 /* extended ACK TVLs were included */
51 #ifndef NLA_NUL_STRING
52 # define NLA_NUL_STRING 10
59 #ifndef HAVE_NLA_GET_S32
64 * Return payload of 32 bit signed integer attribute.
66 * @arg nla 32 bit integer attribute.
68 * @return Payload as 32 bit integer.
70 int32_t nla_get_s32(const struct nlattr *nla)
72 return *(const int32_t *) nla_data(nla);
74 #endif /* ! HAVE_NLA_GET_S32 */
76 #ifndef HAVE_NLA_GET_S64
81 * Return payload of s64 attribute
83 * @arg nla s64 netlink attribute
85 * @return Payload as 64 bit integer.
87 int64_t nla_get_s64(const struct nlattr *nla)
91 if (nla && nla_len(nla) >= sizeof(tmp))
92 memcpy(&tmp, nla_data(nla), sizeof(tmp));
97 #define NLA_PUT_S64(msg, attrtype, value) \
98 NLA_PUT_TYPE(msg, int64_t, attrtype, value)
100 #endif /* ! HAVE_NLA_GET_S64 */
103 * Set NETLINK_BROADCAST_ERROR flags on socket to report ENOBUFS errors.
105 * @sk Socket to change the flags.
107 * Return 0 on success or a Netlink error code.
109 int nl_socket_enable_broadcast_error(struct nl_sock *sk)
111 const int state = 1; /* enable errors */
114 if (nl_socket_get_fd(sk) < 0)
115 return -NLE_BAD_SOCK;
117 err = setsockopt(nl_socket_get_fd(sk), SOL_NETLINK,
118 NETLINK_BROADCAST_ERROR, &state, sizeof(state));
120 return -nl_syserr2nlerr(errno);
126 * Enable/disable extending ACK for netlink socket. Used for
127 * sending extra debugging information.
129 * @arg sk Netlink socket.
130 * @arg state New state (0 - disabled, 1 - enabled)
132 * @return 0 on success or a negative error code
134 int nl_socket_set_ext_ack(struct nl_sock *sk, int state)
138 if (nl_socket_get_fd(sk) < 0)
139 return -NLE_BAD_SOCK;
141 err = setsockopt(nl_socket_get_fd(sk), SOL_NETLINK,
142 NETLINK_EXT_ACK, &state, sizeof(state));
143 if (err < 0 && errno != ENOPROTOOPT)
144 return -nl_syserr2nlerr(errno);
150 * Create a Netlink socket
152 * @sk The nl_sock which we used to handle the Netlink
154 * @async_events tell the Netlink socket this will receive asynchronous
157 * Return 0 on success or a negative error code.
159 int lustre_netlink_register(struct nl_sock *sk, bool async_events)
163 rc = genl_connect(sk);
167 rc = nl_socket_enable_broadcast_error(sk);
171 rc = nl_socket_set_ext_ack(sk, true);
176 /* Required to receive async netlink event notifications */
177 nl_socket_disable_seq_check(sk);
178 /* Don't need ACK for events generated by kernel */
179 nl_socket_disable_auto_ack(sk);
186 * Filter Netlink socket by groups
189 * @family The family name of the Netlink socket.
190 * @group Netlink messages will only been sent if they belong to this
193 * Return 0 on success or a negative error code.
195 int lustre_netlink_add_group(struct nl_sock *nl, const char *family,
201 group_id = genl_ctrl_resolve_grp(nl, family, group);
205 /* subscribe to generic netlink multicast group */
206 return nl_socket_add_membership(nl, group_id);
209 /* A YAML file is used to describe data. In a YAML document the content is
210 * all about a collection of scalars used to create new data types such as
211 * key-value pairs. This allows complex documents to represent anything from
212 * a string to a tree.
216 * YAML scalars are a simple value which can be a string, number or Boolean.
217 * They are the simplest data types. They can exist in a YAML document but
218 * are typically used to build more complex data formats.
222 * In YAML collections are scalar elements presented in the form of
223 * an array, called a sequence, or mappings (hashes) that are scalar
224 * key value pairs. All elements belonging to the same collection are
225 * the lines that begin at the same indentation level
227 * Sequences use a dash followed by a space.
228 * Mappings use a colon followed by a space (: ) to mark each key/value pair:
230 * Collections can be represented in two forms, flow and block.
231 * Note they are equivalent. Example of block sequence is;
237 * and a block mapping example is:
243 * YAML flow styles for collections uses explicit indicators rather than
244 * indentation to denote scope.
246 * A sequence can be written as a comma separated list within
247 * square brackets ([]):
249 * [ PHP, Perl, Python ]
251 * A mapping can be written as a comma separated list of key/values within
254 * { PHP: 5.2, MySQL: 5.1, Apache: 2.2.20 }
256 * NOTE!! flow and block are equivalent.
260 * A list is a defined array of data which can be either an flow or block
261 * sequence. Lists can be nested. Example
263 * numbers: [ 1, 2, 3, 4 ]
273 * Are comprised of a key: value format with contents indented. This is
274 * built on top of the flow or block mapping. Like lists they can be nested.
282 /* In YAML you have the concept of parsers and emitters. Parser
283 * consume YAML input from a file, character buffer, or in our
284 * case Netlink and emitters take data from some source and
285 * present it in a YAML format.
287 * In this section of the code we are handling the parsing of the
288 * Netlink packets coming in and using them to piece together a
289 * YAML document. We could in theory just dump a YAML document
290 * one line at a time over Netlink but the amount of data could
291 * become very large and impact performance. Additionally, having
292 * pseudo-YAML code in the kernel would be frowned on. We can
293 * optimize the network traffic by taking advantage of the fact
294 * that for key/value pairs the keys rarely change. We can
295 * break up the data into keys and the values. The first Netlink
296 * data packets received will be a nested keys table which we
297 * can cache locally. As we receive the value pairs we can then
298 * reconstruct the key : value pair by looking up the the key
299 * in the stored table. In effect we end up with a one key to
300 * many values stream of data.
302 * The data structures below are used to create a tree data
303 * structure which is the natural flow of both YAML and
306 struct yaml_nl_node {
307 struct nl_list_head list;
308 struct nl_list_head children;
309 struct ln_key_list keys;
312 struct yaml_netlink_input {
313 yaml_parser_t *parser;
320 struct yaml_nl_node *cur;
321 struct yaml_nl_node *root;
324 /* Sadly this is not exported out of libyaml. We want to
325 * give descent error message to help people track down
326 * issues. This is internal only to this code. The end
327 * user will never need to use this.
330 yaml_parser_set_reader_error(yaml_parser_t *parser, const char *problem,
331 size_t offset, int value)
333 parser->error = YAML_READER_ERROR;
334 parser->problem = problem;
335 parser->problem_offset = offset;
336 parser->problem_value = value;
341 /* This is used to handle all the Netlink packets containing the keys
342 * for the key/value pairs. Instead of creating unique code to handle
343 * every type of Netlink attributes possible we create a generic
344 * abstract so the same code be used with everything. To make this
345 * work the key table trasmitted must report the tree structure and
346 * state of the keys. We use nested attributes as a way to notify libyaml
347 * we have a new collection. This is used to create the tree structure
348 * of the YAML document. Each collection of attributes define the following:
350 * LN_SCALAR_ATTR_INDEX:
351 * enum XXX_ATTR that defines which value we are dealing with. This
352 * varies greatly depending on the subsystem we have developed for.
354 * LN_SCALAR_ATTR_NLA_TYPE:
355 * The Netlink attribute type (NLA_STRING, NLA_U32, etc..) the coming
358 * LN_SCALAR_ATTR_VALUE:
359 * The string represnting key's actually scalar value.
361 * LN_SCALAR_ATTR_INT_VALUE:
362 * For this case the key is an integer value. This shouldn't be
363 * sent for the receive case since we are going to just turn it
364 * into a string for YAML. Sending packets will make use of this.
366 * LN_SCALAR_ATTR_KEY_TYPE:
367 * What YAML format is it? block or flow. Only useful for
368 * LN_SCALAR_ATTR_NLA_TYPE of type NLA_NESTED or NLA_NUL_STRING
370 * LN_SCALAR_ATTR_LIST + LN_SCALAR_LIST_SIZE:
371 * Defined the next collection which is a collection of nested
372 * attributes of the above.
374 static struct nla_policy scalar_attr_policy[LN_SCALAR_MAX + 1] = {
375 [LN_SCALAR_ATTR_LIST] = { .type = NLA_NESTED },
376 [LN_SCALAR_ATTR_LIST_SIZE] = { .type = NLA_U16 },
377 [LN_SCALAR_ATTR_INDEX] = { .type = NLA_U16 },
378 [LN_SCALAR_ATTR_NLA_TYPE] = { .type = NLA_U16 },
379 [LN_SCALAR_ATTR_VALUE] = { .type = NLA_STRING },
380 [LN_SCALAR_ATTR_INT_VALUE] = { .type = NLA_S64 },
381 [LN_SCALAR_ATTR_KEY_FORMAT] = { .type = NLA_U16 },
384 static int yaml_parse_key_list(struct yaml_netlink_input *data,
385 struct yaml_nl_node *parent,
388 struct nlattr *tbl_info[LN_SCALAR_MAX + 1];
389 struct yaml_nl_node *node = NULL;
393 nla_for_each_nested(attr, list, rem) {
396 if (nla_parse_nested(tbl_info, LN_SCALAR_MAX, attr,
400 if (tbl_info[LN_SCALAR_ATTR_LIST_SIZE]) {
403 cnt = nla_get_u16(tbl_info[LN_SCALAR_ATTR_LIST_SIZE]) + 1;
405 size_t len = sizeof(struct nl_list_head) * 2;
407 len += sizeof(struct ln_key_props) * cnt;
408 node = calloc(1, len);
412 node->keys.lkl_maxattr = cnt;
413 NL_INIT_LIST_HEAD(&node->children);
414 nl_init_list_head(&node->list);
421 nl_list_add_tail(&node->list,
426 if (tbl_info[LN_SCALAR_ATTR_INDEX])
427 index = nla_get_u16(tbl_info[LN_SCALAR_ATTR_INDEX]);
429 if (!node || index == 0)
432 if (tbl_info[LN_SCALAR_ATTR_KEY_FORMAT]) {
435 format = nla_get_u16(tbl_info[LN_SCALAR_ATTR_KEY_FORMAT]);
436 node->keys.lkl_list[index].lkp_key_format = format;
439 if (tbl_info[LN_SCALAR_ATTR_NLA_TYPE]) {
442 type = nla_get_u16(tbl_info[LN_SCALAR_ATTR_NLA_TYPE]);
443 node->keys.lkl_list[index].lkp_data_type = type;
446 if (tbl_info[LN_SCALAR_ATTR_VALUE]) {
449 name = nla_strdup(tbl_info[LN_SCALAR_ATTR_VALUE]);
452 node->keys.lkl_list[index].lkp_value = name;
455 if (tbl_info[LN_SCALAR_ATTR_LIST]) {
456 int rc = yaml_parse_key_list(data, node,
457 tbl_info[LN_SCALAR_ATTR_LIST]);
465 static struct yaml_nl_node *get_next_child(struct yaml_nl_node *node,
468 struct yaml_nl_node *child;
471 nl_list_for_each_entry(child, &node->children, list)
479 * In the YAML C implementation the scanner transforms the input stream
480 * (Netlink in this case) into a sequence of keys. First we need to
481 * examine the potential keys involved to see the mapping to Netlink.
482 * We have chosen to examine the YAML stack with keys since they are
483 * more detailed when compared to yaml_document_t / yaml_nodes and
486 * STREAM-START(encoding) # The stream start.
487 * STREAM-END # The stream end.
488 * VERSION-DIRECTIVE(major,minor) # The '%YAML' directive.
489 * TAG-DIRECTIVE(handle,prefix) # The '%TAG' directive.
490 * DOCUMENT-START # '---'
491 * DOCUMENT-END # '...'
492 * BLOCK-SEQUENCE-START # Indentation increase denoting a block
493 * BLOCK-MAPPING-START # sequence or a block mapping.
494 * BLOCK-END # Indentation decrease.
495 * FLOW-SEQUENCE-START # '['
496 * FLOW-SEQUENCE-END # ']'
497 * FLOW-MAPPING-START # '{'
498 * FLOW-MAPPING-END # '}'
501 * KEY # '?' or nothing (simple keys).
503 * ALIAS(anchor) # '*anchor'
504 * ANCHOR(anchor) # '&anchor'
505 * TAG(handle,suffix) # '!handle!suffix'
506 * SCALAR(value,style) # A scalar.
508 * For our read_handler / write_handler STREAM-START / STREAM-END,
509 * VERSION-DIRECTIVE, and TAG-DIRECTIVE are hanndler by the libyaml
510 * internal scanner so we don't need to deal with it. Normally for
511 * LNet / Lustre DOCUMENT-START / DOCUMENT-END are not needed but it
512 * could be easily handled. In the case of multiplex streams we could
513 * see these used to differentiate data coming in.
515 * It is here we handle any simple scalars or values of the key /value
516 * pair. How the YAML document is formated is dependent on the key
519 static void yaml_parse_value_list(struct yaml_netlink_input *data, int *size,
520 struct nlattr *attr_array[],
521 struct ln_key_props *parent)
523 struct yaml_nl_node *node = data->cur;
524 struct ln_key_props *keys = node->keys.lkl_list;
525 int mapping = parent->lkp_key_format;
526 int child_idx = 0, len = 0, i;
528 for (i = 1; i < node->keys.lkl_maxattr; i++) {
531 attr = attr_array[i];
532 if (!attr && !keys[i].lkp_value)
535 if (keys[i].lkp_data_type != NLA_NUL_STRING &&
536 keys[i].lkp_data_type != NLA_NESTED) {
540 if (!(mapping & LNKF_FLOW)) {
541 unsigned int indent = data->indent ?
544 memset(data->buffer, ' ', indent);
545 if (mapping & LNKF_SEQUENCE) {
546 ((char *)data->buffer)[indent - 2] = '-';
547 if (mapping & LNKF_MAPPING)
548 mapping &= ~LNKF_SEQUENCE;
550 data->buffer += indent;
554 if (mapping & LNKF_MAPPING) {
555 len = snprintf(data->buffer, *size, "%s: ",
564 switch (keys[i].lkp_data_type) {
566 struct yaml_nl_node *next = get_next_child(node,
568 int num = next->keys.lkl_maxattr;
569 struct nla_policy nest_policy[num];
570 struct yaml_nl_node *old;
571 struct nlattr *cnt_attr;
577 memset(nest_policy, 0, sizeof(struct nla_policy) * num);
578 for (j = 1; j < num; j++)
579 nest_policy[j].type = next->keys.lkl_list[j].lkp_data_type;
583 nla_for_each_nested(cnt_attr, attr, rem) {
584 struct nlattr *nest_info[num];
587 if (nla_parse_nested(nest_info, num, cnt_attr,
591 if (keys[i].lkp_key_format & LNKF_FLOW) {
594 if (keys[i].lkp_key_format &
598 len = snprintf(data->buffer, *size,
604 if (keys[i].lkp_key_format &
607 if (keys[i].lkp_key_format &
611 len = snprintf(data->buffer, *size,
622 data->indent += indent;
623 yaml_parse_value_list(data, size, nest_info,
625 data->indent -= indent;
627 if (keys[i].lkp_key_format & LNKF_FLOW) {
628 char *tmp = (char *)data->buffer - 2;
629 char *brace = " }\n";
631 if (keys[i].lkp_key_format &
635 memcpy(tmp, brace, strlen(brace));
646 if (data->cur != data->root)
649 /* The top level is special so only print
652 if (strlen(keys[i].lkp_value)) {
653 len = snprintf(data->buffer,
663 if (!(mapping & LNKF_FLOW)) {
664 if (mapping & LNKF_SEQUENCE)
666 else if (mapping & LNKF_MAPPING)
670 if (attr && parent->lkp_value) {
671 free(parent->lkp_value);
672 parent->lkp_value = nla_strdup(attr);
678 len = snprintf(data->buffer, *size, "%s",
679 nla_get_string(attr));
683 len = snprintf(data->buffer, *size, "%hu",
688 len = snprintf(data->buffer, *size, "%u",
693 len = snprintf(data->buffer, *size, "%ju",
698 len = snprintf(data->buffer, *size, "%hd",
703 len = snprintf(data->buffer, *size, "%d",
708 len = snprintf(data->buffer, *size, "%jd",
716 if (mapping & LNKF_FLOW) {
717 strcat((char *)data->buffer, ", ");
720 ((char *)data->buffer)[len++] = '\n';
724 } else if (len < 0) {
726 data->buffer -= data->indent + 2;
727 *size -= data->indent + 2;
732 /* This is the CB_VALID callback for the Netlink library that we
733 * have hooked into. Any successful Netlink message is passed to
734 * this function which handles both the incoming key tables and
735 * the values of the key/value pairs being received. We use
736 * the NLM_F_CREATE flag to determine if the incoming Netlink
737 * message is a key table or a packet containing value pairs.
739 static int yaml_netlink_msg_parse(struct nl_msg *msg, void *arg)
741 struct yaml_netlink_input *data = arg;
742 struct nlmsghdr *nlh = nlmsg_hdr(msg);
744 if (nlh->nlmsg_flags & NLM_F_CREATE) {
745 struct nlattr *attrs[LN_SCALAR_MAX + 1];
747 if (genlmsg_parse(nlh, 0, attrs, LN_SCALAR_MAX + 1,
751 if (attrs[LN_SCALAR_ATTR_LIST]) {
752 int rc = yaml_parse_key_list(data, NULL,
753 attrs[LN_SCALAR_ATTR_LIST]);
757 /* reset to root node */
758 data->cur = data->root;
761 /* For streaming insert '---' to define start of
762 * YAML document. This allows use to extract
763 * documents out of a multiplexed stream.
766 char *start_doc = "---\n";
767 size_t len = strlen(start_doc) + 1;
769 strncpy(data->buffer, start_doc, len);
770 data->buffer += len - 1;
773 uint16_t maxtype = data->cur->keys.lkl_maxattr;
774 struct nla_policy policy[maxtype];
775 struct nlattr *attrs[maxtype];
778 memset(policy, 0, sizeof(struct nla_policy) * maxtype);
779 for (i = 1; i < maxtype; i++)
780 policy[i].type = data->cur->keys.lkl_list[i].lkp_data_type;
782 if (genlmsg_parse(nlh, 0, attrs, maxtype, policy))
785 size = data->parser->raw_buffer.end -
786 (unsigned char *)data->buffer;
787 yaml_parse_value_list(data, &size, attrs,
788 &data->cur->keys.lkl_list[1]);
791 /* Let yaml_netlink_msg_complete end collecting data */
795 static bool cleanup_children(struct yaml_nl_node *parent)
797 struct yaml_nl_node *child;
799 if (nl_list_empty(&parent->children)) {
800 struct ln_key_props *keys = parent->keys.lkl_list;
803 for (i = 1; i < parent->keys.lkl_maxattr; i++)
804 if (keys[i].lkp_value)
805 free(keys[i].lkp_value);
806 nl_list_del(&parent->list);
810 while ((child = get_next_child(parent, 0)) != NULL) {
811 if (cleanup_children(child))
818 /* This is the libnl callback for when the last Netlink packet
819 * is finished being parsed or its called right away in case
820 * the Linux kernel reports back an error from the Netlink layer.
822 static int yaml_netlink_msg_complete(struct nl_msg *msg, void *arg)
824 struct yaml_netlink_input *data = arg;
825 struct nlmsghdr *nlh = nlmsg_hdr(msg);
826 struct nlmsgerr *errmsg = nlmsg_data(nlh);
828 if ((nlh->nlmsg_type == NLMSG_ERROR ||
829 nlh->nlmsg_flags & NLM_F_ACK_TLVS) && errmsg->error) {
830 /* libyaml stomps on the reader error so we need to
831 * cache the source of the error.
833 data->errmsg = nl_geterror(nl_syserr2nlerr(errmsg->error));
834 #ifdef HAVE_USRSPC_NLMSGERR
835 /* Newer kernels support NLM_F_ACK_TLVS in nlmsg_flags
836 * which gives greater detail why we failed.
838 if (nlh->nlmsg_flags & NLM_F_ACK_TLVS &&
839 !(nlh->nlmsg_flags & NLM_F_CAPPED)) {
840 struct nlattr *head = ((void *)&errmsg->msg);
841 struct nlattr *tb[NLMSGERR_ATTR_MAX + 1];
843 if (nla_parse(tb, NLMSGERR_ATTR_MAX + 1, head,
844 nlmsg_attrlen(nlh, 0), NULL) == 0) {
845 if (tb[NLMSGERR_ATTR_MSG])
846 data->errmsg = nla_strdup(tb[NLMSGERR_ATTR_MSG]);
849 #endif /* HAVE_USRSPC_NLMSGERR */
850 data->parser->error = YAML_READER_ERROR;
851 data->complete = true;
856 cleanup_children(data->root);
860 /* For streaming insert '...' to define end of
864 char *end_doc = "...\n";
865 size_t len = strlen(end_doc) + 1;
867 strncpy(data->buffer, end_doc, len);
868 data->buffer += len - 1;
870 data->complete = true;
873 return data->async ? NL_OK : NL_STOP;
877 * In order for yaml_parser_set_input_netlink() to work we have to
878 * register a yaml_read_handler_t callback. This is that call back
879 * which listens for Netlink packets. Internally nl_recvmsg_report()
880 * calls the various callbacks discussed above.
882 static int yaml_netlink_read_handler(void *arg, unsigned char *buffer,
883 size_t size, size_t *size_read)
885 struct yaml_netlink_input *data = arg;
886 struct nl_sock *nl = data->nl;
890 if (data->complete) {
895 data->buffer = buffer;
897 cb = nl_socket_get_cb(nl);
898 rc = nl_recvmsgs_report(nl, cb);
899 if (rc == -NLE_INTR) {
903 data->errmsg = nl_geterror(rc);
905 } else if (data->parser->error) {
906 /* data->errmsg is set in NL_CB_FINISH */
910 rc = (unsigned char *)data->buffer - buffer;
918 /* libyaml by default just reports "input error" for parser read_handler_t
919 * issues which is not useful. This provides away to get better debugging
922 YAML_DECLARE(const char *)
923 yaml_parser_get_reader_error(yaml_parser_t *parser)
925 struct yaml_netlink_input *buf = parser->read_handler_data;
933 /* yaml_parser_set_input_netlink() mirrors the libyaml function
934 * yaml_parser_set_input_file(). Internally it does setup of the
935 * libnl socket callbacks to parse the Netlink messages received
936 * as well as register the special yaml_read_handler_t for libyaml.
937 * This is exposed for public use.
940 yaml_parser_set_input_netlink(yaml_parser_t *reply, struct nl_sock *nl,
943 struct yaml_netlink_input *buf;
946 buf = calloc(1, sizeof(*buf));
948 reply->error = YAML_MEMORY_ERROR;
952 rc = lustre_netlink_register(nl, stream);
954 yaml_parser_set_reader_error(reply,
955 "netlink setup failed", 0,
963 yaml_parser_set_input(buf->parser, yaml_netlink_read_handler, buf);
965 rc = nl_socket_modify_cb(buf->nl, NL_CB_VALID, NL_CB_CUSTOM,
966 yaml_netlink_msg_parse, buf);
968 yaml_parser_set_reader_error(reply,
969 "netlink msg recv setup failed",
974 rc = nl_socket_modify_cb(buf->nl, NL_CB_FINISH, NL_CB_CUSTOM,
975 yaml_netlink_msg_complete, buf);
977 yaml_parser_set_reader_error(reply,
978 "netlink msg cleanup setup failed",
983 return rc < 0 ? false : true;
986 /* The role of the YAML emitter for us is to take a YAML document and
987 * change into a Netlink stream to send to the kernel to be processed.
988 * This provides the infrastructure to do this.
990 struct yaml_netlink_output {
991 yaml_emitter_t *emitter;
1001 /* Internal use for this file only. We fill in details of why creating
1002 * a Netlink packet to send failed. The end user will be able to debug
1006 yaml_emitter_set_writer_error(yaml_emitter_t *emitter, const char *problem)
1008 emitter->error = YAML_WRITER_ERROR;
1009 emitter->problem = problem;
1014 static unsigned int indent_level(const char *str)
1016 char *tmp = (char *)str;
1018 while (isspace(*tmp))
1025 static enum lnet_nl_key_format yaml_format_type(yaml_emitter_t *emitter,
1027 unsigned int *offset,
1028 enum lnet_nl_key_format prev)
1030 enum lnet_nl_key_format fmt = 0;
1031 unsigned int indent = *offset;
1032 unsigned int new_indent = 0;
1034 if (strchr(line, '{') || strchr(line, '[')) {
1036 if (strchr(line, '{'))
1037 fmt |= LNKF_MAPPING;
1041 new_indent = indent_level(line);
1042 if (new_indent < indent) {
1043 *offset = indent - emitter->best_indent;
1047 if (strncmp(line + new_indent, "- ", 2) == 0) {
1048 *offset = new_indent + emitter->best_indent;
1049 fmt = LNKF_SEQUENCE;
1051 if (strstr(line + new_indent, ": "))
1052 fmt |= LNKF_MAPPING;
1056 if (indent != new_indent) {
1057 *offset = new_indent;
1058 if (prev != LNKF_MAPPING)
1059 return LNKF_MAPPING;
1065 static int yaml_fill_scalar_data(struct nl_msg *msg,
1066 enum lnet_nl_key_format fmt,
1069 char *sep = strchr(line, ':');
1075 NLA_PUT_STRING(msg, LN_SCALAR_ATTR_VALUE, line);
1076 if (fmt & LNKF_MAPPING && sep) {
1077 while (isspace(*sep))
1080 if (strspn(sep, "0123456789") == strlen(sep)) {
1081 unsigned long num = strtoull(sep, NULL, 0);
1083 NLA_PUT_S64(msg, LN_SCALAR_ATTR_INT_VALUE, num);
1085 NLA_PUT_STRING(msg, LN_SCALAR_ATTR_VALUE, sep);
1092 static int yaml_create_nested_list(struct yaml_netlink_output *out,
1093 struct nl_msg *msg, char **hdr,
1094 char **entry, unsigned int *indent,
1095 enum lnet_nl_key_format fmt)
1097 struct nlattr *list = NULL;
1101 list = nla_nest_start(msg, LN_SCALAR_ATTR_LIST);
1103 yaml_emitter_set_writer_error(out->emitter,
1104 "Emmitter netlink list creation failed");
1106 goto nla_put_failure;
1109 if (fmt & LNKF_FLOW) {
1112 tmp = strchr(*hdr, '{');
1114 tmp = strchr(*hdr, '[');
1116 yaml_emitter_set_writer_error(out->emitter,
1117 "Emmitter flow format invalid");
1119 goto nla_put_failure;
1124 tmp = strchr(*hdr, '}');
1126 tmp = strchr(*hdr, ']');
1128 yaml_emitter_set_writer_error(out->emitter,
1129 "Emmitter flow format invalid");
1131 goto nla_put_failure;
1136 while ((line = strsep(hdr, ",")) != NULL) {
1137 if (isspace(line[0]))
1139 rc = yaml_fill_scalar_data(msg, fmt, line);
1141 goto nla_put_failure;
1143 nla_nest_end(msg, list);
1147 rc = yaml_fill_scalar_data(msg, fmt, *hdr + *indent);
1149 goto nla_put_failure;
1151 line = strsep(entry, "\n");
1153 if (!line || !strlen(line) || strcmp(line, "...") == 0)
1156 fmt = yaml_format_type(out->emitter, line, indent, fmt);
1157 if (fmt == LNKF_END)
1160 if (fmt & ~LNKF_MAPPING) { /* Filter out mappings */
1161 rc = yaml_create_nested_list(out, msg, &line, entry,
1164 goto nla_put_failure;
1166 goto have_next_line;
1168 rc = yaml_fill_scalar_data(msg, fmt, line + *indent);
1170 goto nla_put_failure;
1172 } while (strcmp(line, ""));
1174 nla_nest_end(msg, list);
1175 /* strsep in the above loop moves entry to a value pass the end of the
1176 * nested list. So to avoid losing this value we replace hdr with line
1183 /* YAML allows ' and " in its documents but those characters really
1184 * confuse libc string handling. The workaround is to replace
1185 * ' and " with another reserved character for YAML '%' which is
1186 * for tags which shouldn't matter if we send in a Netlink packet.
1187 * The kernel side will need to handle % in a special way.
1189 static void yaml_quotation_handling(char *buf)
1191 char *tmp = buf, *line;
1193 line = strstr(tmp, "! \'");
1197 while ((line = strchr(tmp, '\"')) != NULL) {
1199 tmp = strchr(line, '\"');
1203 while ((line = strchr(tmp, '\'')) != NULL) {
1205 tmp = strchr(line, '\'');
1210 /* libyaml takes the YAML documents and places the data into an
1211 * internal buffer to the library. We take each line and turn it
1212 * into a Netlink message using the same format as the key table.
1213 * The reason for this approach is that we can do filters at the
1214 * key level or the key + value level.
1216 static int yaml_netlink_write_handler(void *data, unsigned char *buffer,
1219 struct yaml_netlink_output *out = data;
1220 char *buf = strndup((char *)buffer, size);
1221 char *entry = buf, *tmp = buf, *line;
1222 enum lnet_nl_key_format fmt = 0;
1223 struct nl_msg *msg = NULL;
1224 unsigned int indent = 0;
1225 bool nogroups = true;
1228 yaml_quotation_handling(entry);
1230 while (entry && strcmp(line = strsep(&entry, "\n"), "")) {
1232 if (strcmp(line, "---") == 0 || strcmp(line, "...") == 0)
1235 /* In theory we could have a sequence of groups but a bug in
1236 * libyaml prevents this from happing
1238 if (line[0] != ' ' && line[0] != '-') {
1239 tmp = strchr(line, ':');
1244 rc = lustre_netlink_add_group(out->nl, out->family,
1247 yaml_emitter_set_writer_error(out->emitter,
1248 "Netlink group does not exist");
1249 goto nla_put_failure;
1253 /* Handle case first line contains more than a
1257 if (strchr(line, '{') || strchr(line, '['))
1264 msg = nlmsg_alloc();
1266 out->emitter->error = YAML_MEMORY_ERROR;
1267 goto nla_put_failure;
1270 usr_hdr = genlmsg_put(msg, out->pid,
1273 out->flags, out->cmd,
1276 out->emitter->error = YAML_MEMORY_ERROR;
1278 goto nla_put_failure;
1282 fmt = yaml_format_type(out->emitter, line, &indent,
1284 if (fmt & ~LNKF_MAPPING) {
1285 rc = yaml_create_nested_list(out, msg, &line,
1289 yaml_emitter_set_writer_error(out->emitter,
1292 goto nla_put_failure;
1294 /* yaml_created_nested_list set line to the next
1295 * entry. We can just add it to the msg directly.
1298 goto already_have_line;
1300 rc = yaml_fill_scalar_data(msg, fmt,
1303 yaml_emitter_set_writer_error(out->emitter,
1306 goto nla_put_failure;
1312 /* Don't success if no valid groups found */
1314 yaml_emitter_set_writer_error(out->emitter,
1315 "Emitter contains no valid Netlink groups");
1316 goto nla_put_failure;
1320 rc = nl_send_auto(out->nl, msg);
1323 rc = genl_send_simple(out->nl, out->family_id, out->cmd,
1324 out->version, out->flags);
1327 yaml_emitter_set_writer_error(out->emitter,
1331 return out->emitter->error == YAML_NO_ERROR ? 1 : 0;
1334 /* This is the libnl callback for when an error has happened
1335 * kernel side. An error message is sent back to the user.
1337 static int yaml_netlink_write_error(struct sockaddr_nl *who,
1338 struct nlmsgerr *errmsg, void *arg)
1340 struct yaml_netlink_output *data = arg;
1341 struct nlmsghdr *nlh = &errmsg->msg;
1343 if ((nlh->nlmsg_type == NLMSG_ERROR ||
1344 nlh->nlmsg_flags & NLM_F_ACK_TLVS) && errmsg->error) {
1345 const char *errstr = nl_geterror(nl_syserr2nlerr(errmsg->error));
1347 #ifdef HAVE_USRSPC_NLMSGERR
1348 /* Newer kernels support NLM_F_ACK_TLVS in nlmsg_flags
1349 * which gives greater detail why we failed.
1351 if (nlh->nlmsg_flags & NLM_F_ACK_TLVS &&
1352 !(nlh->nlmsg_flags & NLM_F_CAPPED)) {
1353 struct nlattr *head = ((void *)&errmsg->msg);
1354 struct nlattr *tb[NLMSGERR_ATTR_MAX + 1];
1356 if (nla_parse(tb, NLMSGERR_ATTR_MAX + 1, head,
1357 nlmsg_attrlen(nlh, 0), NULL) == 0) {
1358 if (tb[NLMSGERR_ATTR_MSG])
1359 errstr = nla_strdup(tb[NLMSGERR_ATTR_MSG]);
1362 #endif /* HAVE_USRSPC_NLMSGERR */
1363 yaml_emitter_set_writer_error(data->emitter, errstr);
1368 /* This function is used by external utilities to use Netlink with
1369 * libyaml so we can turn YAML documentations into Netlink message
1370 * to send. This behavior mirrors yaml_emitter_set_output_file()
1371 * which is used to write out a YAML document to a file.
1374 yaml_emitter_set_output_netlink(yaml_emitter_t *sender, struct nl_sock *nl,
1375 char *family, int version, int cmd, int flags)
1377 struct yaml_netlink_output *out;
1380 out = calloc(1, sizeof(*out));
1382 sender->error = YAML_MEMORY_ERROR;
1387 out->family_id = genl_ctrl_resolve(nl, family);
1388 if (out->family_id < 0) {
1389 yaml_emitter_set_writer_error(sender,
1390 "failed to resolve Netlink family id");
1395 rc = nl_socket_modify_err_cb(nl, NL_CB_CUSTOM,
1396 yaml_netlink_write_error, out);
1398 yaml_emitter_set_writer_error(sender,
1399 "failed to register error handling");
1404 rc = nl_socket_enable_broadcast_error(nl);
1406 yaml_emitter_set_writer_error(sender,
1407 "failed to enable broadcast errors");
1412 rc = nl_socket_set_ext_ack(nl, true);
1414 yaml_emitter_set_writer_error(sender,
1415 "failed to enable ext ack");
1420 out->emitter = sender;
1422 out->family = family;
1423 out->version = version;
1426 out->pid = nl_socket_get_local_port(nl);
1427 yaml_emitter_set_output(sender, yaml_netlink_write_handler, out);
1431 /* Error handling helpers */
1432 void yaml_emitter_log_error(yaml_emitter_t *emitter, FILE *log)
1434 /* YAML_WRITER_ERROR means no Netlink support so use old API */
1435 switch (emitter->error) {
1436 case YAML_MEMORY_ERROR:
1437 fprintf(log, "Memory error: Not enough memory for emitting\n");
1439 case YAML_WRITER_ERROR:
1440 fprintf(log, "Writer error: %s\n", emitter->problem);
1442 case YAML_EMITTER_ERROR:
1443 fprintf(log, "Emitter error: %s\n", emitter->problem);
1449 void yaml_parser_log_error(yaml_parser_t *parser, FILE *log, const char *errmsg)
1453 switch (parser->error) {
1454 case YAML_MEMORY_ERROR:
1455 fprintf(log, "Memory error: Not enough memory for parser\n");
1458 case YAML_SCANNER_ERROR:
1459 case YAML_PARSER_ERROR:
1460 if (parser->context) {
1462 "%s error: %s at line %d, column %d\n%s at line %d, column %d\n",
1463 parser->error == YAML_SCANNER_ERROR ? "Scanner" : "Parser",
1465 (int)parser->context_mark.line + 1,
1466 (int)parser->context_mark.column + 1,
1468 (int)parser->problem_mark.line + 1,
1469 (int)parser->problem_mark.column + 1);
1471 fprintf(log, "%s error: %s at line %d, column %d\n",
1472 parser->error == YAML_SCANNER_ERROR ? "Scanner" : "Parser",
1474 (int)parser->problem_mark.line + 1,
1475 (int)parser->problem_mark.column + 1);
1479 case YAML_READER_ERROR:
1480 extra = yaml_parser_get_reader_error(parser);
1482 extra = parser->problem;
1484 if (parser->problem_value != -1) {
1485 fprintf(log, "Reader error: '%s':#%X at %ld'\n",
1486 extra, parser->problem_value,
1487 (long)parser->problem_offset);
1489 fprintf(log, "Reader error: '%s' at %ld\n",
1490 extra, (long)parser->problem_offset);