1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2013 Tom Gundersen <teg@jklm.no>
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
22 #include <netinet/in.h>
27 #include "socket-util.h"
28 #include "formats-util.h"
32 #include "sd-netlink.h"
33 #include "netlink-util.h"
34 #include "netlink-internal.h"
35 #include "netlink-types.h"
37 #define GET_CONTAINER(m, i) ((i) < (m)->n_containers ? (struct rtattr*)((uint8_t*)(m)->hdr + (m)->containers[i].offset) : NULL)
38 #define PUSH_CONTAINER(m, new) (m)->container_offsets[(m)->n_containers ++] = (uint8_t*)(new) - (uint8_t*)(m)->hdr;
40 #define RTA_TYPE(rta) ((rta)->rta_type & NLA_TYPE_MASK)
41 #define RTA_FLAGS(rta) ((rta)->rta_type & ~NLA_TYPE_MASK)
43 int message_new_empty(sd_netlink *rtnl, sd_netlink_message **ret) {
44 sd_netlink_message *m;
46 assert_return(ret, -EINVAL);
48 /* Note that 'rtnl' is currently unused, if we start using it internally
49 we must take care to avoid problems due to mutual references between
50 buses and their queued messages. See sd-bus.
53 m = new0(sd_netlink_message, 1);
57 m->n_ref = REFCNT_INIT;
66 int message_new(sd_netlink *rtnl, sd_netlink_message **ret, uint16_t type) {
67 _cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
68 const NLType *nl_type;
72 r = type_system_get_type(&type_system_root, &nl_type, type);
76 if (type_get_type(nl_type) != NETLINK_TYPE_NESTED)
79 r = message_new_empty(rtnl, &m);
83 size = NLMSG_SPACE(type_get_size(nl_type));
85 assert(size >= sizeof(struct nlmsghdr));
86 m->hdr = malloc0(size);
90 m->hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
92 type_get_type_system(nl_type, &m->containers[0].type_system);
93 m->hdr->nlmsg_len = size;
94 m->hdr->nlmsg_type = type;
102 int sd_netlink_message_request_dump(sd_netlink_message *m, int dump) {
103 assert_return(m, -EINVAL);
104 assert_return(m->hdr, -EINVAL);
105 assert_return(m->hdr->nlmsg_type == RTM_GETLINK ||
106 m->hdr->nlmsg_type == RTM_GETADDR ||
107 m->hdr->nlmsg_type == RTM_GETROUTE ||
108 m->hdr->nlmsg_type == RTM_GETNEIGH,
112 m->hdr->nlmsg_flags |= NLM_F_DUMP;
114 m->hdr->nlmsg_flags &= ~NLM_F_DUMP;
119 sd_netlink_message *sd_netlink_message_ref(sd_netlink_message *m) {
121 assert_se(REFCNT_INC(m->n_ref) >= 2);
126 sd_netlink_message *sd_netlink_message_unref(sd_netlink_message *m) {
127 if (m && REFCNT_DEC(m->n_ref) == 0) {
132 for (i = 0; i <= m->n_containers; i++)
133 free(m->containers[i].attributes);
135 sd_netlink_message_unref(m->next);
143 int sd_netlink_message_get_type(sd_netlink_message *m, uint16_t *type) {
144 assert_return(m, -EINVAL);
145 assert_return(type, -EINVAL);
147 *type = m->hdr->nlmsg_type;
152 int sd_netlink_message_is_broadcast(sd_netlink_message *m) {
153 assert_return(m, -EINVAL);
158 /* If successful the updated message will be correctly aligned, if
159 unsuccessful the old message is untouched. */
160 static int add_rtattr(sd_netlink_message *m, unsigned short type, const void *data, size_t data_length) {
162 size_t message_length, padding_length;
163 struct nlmsghdr *new_hdr;
172 assert(NLMSG_ALIGN(m->hdr->nlmsg_len) == m->hdr->nlmsg_len);
173 assert(!data || data_length);
175 /* get offset of the new attribute */
176 offset = m->hdr->nlmsg_len;
178 /* get the size of the new rta attribute (with padding at the end) */
179 rta_length = RTA_LENGTH(data_length);
181 /* get the new message size (with padding at the end) */
182 message_length = offset + RTA_ALIGN(rta_length);
184 /* realloc to fit the new attribute */
185 new_hdr = realloc(m->hdr, message_length);
190 /* get pointer to the attribute we are about to add */
191 rta = (struct rtattr *) ((uint8_t *) m->hdr + offset);
193 /* if we are inside containers, extend them */
194 for (i = 0; i < m->n_containers; i++)
195 GET_CONTAINER(m, i)->rta_len += message_length - offset;
197 /* fill in the attribute */
198 rta->rta_type = type;
199 rta->rta_len = rta_length;
201 /* we don't deal with the case where the user lies about the type
202 * and gives us too little data (so don't do that)
204 padding = mempcpy(RTA_DATA(rta), data, data_length);
206 /* if no data was passed, make sure we still initialize the padding
207 note that we can have data_length > 0 (used by some containers) */
208 padding = RTA_DATA(rta);
211 /* make sure also the padding at the end of the message is initialized */
212 padding_length = (uint8_t*)m->hdr + message_length - (uint8_t*)padding;
213 memzero(padding, padding_length);
215 /* update message size */
216 m->hdr->nlmsg_len = message_length;
221 static int message_attribute_has_type(sd_netlink_message *m, size_t *out_size, uint16_t attribute_type, uint16_t data_type) {
227 r = type_system_get_type(m->containers[m->n_containers].type_system, &type, attribute_type);
231 if (type_get_type(type) != data_type)
235 *out_size = type_get_size(type);
239 int sd_netlink_message_append_string(sd_netlink_message *m, unsigned short type, const char *data) {
243 assert_return(m, -EINVAL);
244 assert_return(!m->sealed, -EPERM);
245 assert_return(data, -EINVAL);
247 r = message_attribute_has_type(m, &size, type, NETLINK_TYPE_STRING);
252 length = strnlen(data, size+1);
256 length = strlen(data);
258 r = add_rtattr(m, type, data, length + 1);
265 int sd_netlink_message_append_u8(sd_netlink_message *m, unsigned short type, uint8_t data) {
268 assert_return(m, -EINVAL);
269 assert_return(!m->sealed, -EPERM);
271 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U8);
275 r = add_rtattr(m, type, &data, sizeof(uint8_t));
283 int sd_netlink_message_append_u16(sd_netlink_message *m, unsigned short type, uint16_t data) {
286 assert_return(m, -EINVAL);
287 assert_return(!m->sealed, -EPERM);
289 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U16);
293 r = add_rtattr(m, type, &data, sizeof(uint16_t));
300 int sd_netlink_message_append_u32(sd_netlink_message *m, unsigned short type, uint32_t data) {
303 assert_return(m, -EINVAL);
304 assert_return(!m->sealed, -EPERM);
306 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U32);
310 r = add_rtattr(m, type, &data, sizeof(uint32_t));
317 int sd_netlink_message_append_in_addr(sd_netlink_message *m, unsigned short type, const struct in_addr *data) {
320 assert_return(m, -EINVAL);
321 assert_return(!m->sealed, -EPERM);
322 assert_return(data, -EINVAL);
324 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR);
328 r = add_rtattr(m, type, data, sizeof(struct in_addr));
335 int sd_netlink_message_append_in6_addr(sd_netlink_message *m, unsigned short type, const struct in6_addr *data) {
338 assert_return(m, -EINVAL);
339 assert_return(!m->sealed, -EPERM);
340 assert_return(data, -EINVAL);
342 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR);
346 r = add_rtattr(m, type, data, sizeof(struct in6_addr));
353 int sd_netlink_message_append_ether_addr(sd_netlink_message *m, unsigned short type, const struct ether_addr *data) {
356 assert_return(m, -EINVAL);
357 assert_return(!m->sealed, -EPERM);
358 assert_return(data, -EINVAL);
360 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_ETHER_ADDR);
364 r = add_rtattr(m, type, data, ETH_ALEN);
371 int sd_netlink_message_append_cache_info(sd_netlink_message *m, unsigned short type, const struct ifa_cacheinfo *info) {
374 assert_return(m, -EINVAL);
375 assert_return(!m->sealed, -EPERM);
376 assert_return(info, -EINVAL);
378 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_CACHE_INFO);
382 r = add_rtattr(m, type, info, sizeof(struct ifa_cacheinfo));
389 int sd_netlink_message_open_container(sd_netlink_message *m, unsigned short type) {
393 assert_return(m, -EINVAL);
394 assert_return(!m->sealed, -EPERM);
395 assert_return(m->n_containers < RTNL_CONTAINER_DEPTH, -ERANGE);
397 r = message_attribute_has_type(m, &size, type, NETLINK_TYPE_NESTED);
399 const NLTypeSystemUnion *type_system_union;
402 r = message_attribute_has_type(m, &size, type, NETLINK_TYPE_UNION);
406 r = sd_rtnl_message_get_family(m, &family);
410 r = type_system_get_type_system_union(m->containers[m->n_containers].type_system, &type_system_union, type);
414 r = type_system_union_protocol_get_type_system(type_system_union,
415 &m->containers[m->n_containers + 1].type_system,
420 r = type_system_get_type_system(m->containers[m->n_containers].type_system,
421 &m->containers[m->n_containers + 1].type_system,
427 r = add_rtattr(m, type | NLA_F_NESTED, NULL, size);
431 m->containers[m->n_containers ++].offset = r;
436 int sd_netlink_message_open_container_union(sd_netlink_message *m, unsigned short type, const char *key) {
437 const NLTypeSystemUnion *type_system_union;
440 assert_return(m, -EINVAL);
441 assert_return(!m->sealed, -EPERM);
443 r = type_system_get_type_system_union(m->containers[m->n_containers].type_system, &type_system_union, type);
447 r = type_system_union_get_type_system(type_system_union,
448 &m->containers[m->n_containers + 1].type_system,
453 r = sd_netlink_message_append_string(m, type_system_union->match, key);
457 /* do we evere need non-null size */
458 r = add_rtattr(m, type | NLA_F_NESTED, NULL, 0);
462 m->containers[m->n_containers ++].offset = r;
468 int sd_netlink_message_close_container(sd_netlink_message *m) {
469 assert_return(m, -EINVAL);
470 assert_return(!m->sealed, -EPERM);
471 assert_return(m->n_containers > 0, -EINVAL);
473 m->containers[m->n_containers].type_system = NULL;
479 static int netlink_message_read_internal(sd_netlink_message *m, unsigned short type, void **data, bool *net_byteorder) {
480 struct netlink_attribute *attribute;
483 assert_return(m, -EINVAL);
484 assert_return(m->sealed, -EPERM);
485 assert_return(data, -EINVAL);
486 assert(m->n_containers <= RTNL_CONTAINER_DEPTH);
487 assert(m->containers[m->n_containers].attributes);
488 assert(type < m->containers[m->n_containers].n_attributes);
490 attribute = &m->containers[m->n_containers].attributes[type];
492 if(!attribute->offset)
495 rta = (struct rtattr*)((uint8_t *) m->hdr + attribute->offset);
497 *data = RTA_DATA(rta);
500 *net_byteorder = attribute->net_byteorder;
502 return RTA_PAYLOAD(rta);
505 int sd_netlink_message_read_string(sd_netlink_message *m, unsigned short type, const char **data) {
509 assert_return(m, -EINVAL);
511 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_STRING);
515 r = netlink_message_read_internal(m, type, &attr_data, NULL);
518 else if (strnlen(attr_data, r) >= (size_t) r)
522 *data = (const char *) attr_data;
527 int sd_netlink_message_read_u8(sd_netlink_message *m, unsigned short type, uint8_t *data) {
531 assert_return(m, -EINVAL);
533 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U8);
537 r = netlink_message_read_internal(m, type, &attr_data, NULL);
540 else if ((size_t) r < sizeof(uint8_t))
544 *data = *(uint8_t *) attr_data;
549 int sd_netlink_message_read_u16(sd_netlink_message *m, unsigned short type, uint16_t *data) {
554 assert_return(m, -EINVAL);
556 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U16);
560 r = netlink_message_read_internal(m, type, &attr_data, &net_byteorder);
563 else if ((size_t) r < sizeof(uint16_t))
568 *data = be16toh(*(uint16_t *) attr_data);
570 *data = *(uint16_t *) attr_data;
576 int sd_netlink_message_read_u32(sd_netlink_message *m, unsigned short type, uint32_t *data) {
581 assert_return(m, -EINVAL);
583 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U32);
587 r = netlink_message_read_internal(m, type, &attr_data, &net_byteorder);
590 else if ((size_t)r < sizeof(uint32_t))
595 *data = be32toh(*(uint32_t *) attr_data);
597 *data = *(uint32_t *) attr_data;
603 int sd_netlink_message_read_ether_addr(sd_netlink_message *m, unsigned short type, struct ether_addr *data) {
607 assert_return(m, -EINVAL);
609 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_ETHER_ADDR);
613 r = netlink_message_read_internal(m, type, &attr_data, NULL);
616 else if ((size_t)r < sizeof(struct ether_addr))
620 memcpy(data, attr_data, sizeof(struct ether_addr));
625 int sd_netlink_message_read_cache_info(sd_netlink_message *m, unsigned short type, struct ifa_cacheinfo *info) {
629 assert_return(m, -EINVAL);
631 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_CACHE_INFO);
635 r = netlink_message_read_internal(m, type, &attr_data, NULL);
638 else if ((size_t)r < sizeof(struct ifa_cacheinfo))
642 memcpy(info, attr_data, sizeof(struct ifa_cacheinfo));
647 int sd_netlink_message_read_in_addr(sd_netlink_message *m, unsigned short type, struct in_addr *data) {
651 assert_return(m, -EINVAL);
653 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR);
657 r = netlink_message_read_internal(m, type, &attr_data, NULL);
660 else if ((size_t)r < sizeof(struct in_addr))
664 memcpy(data, attr_data, sizeof(struct in_addr));
669 int sd_netlink_message_read_in6_addr(sd_netlink_message *m, unsigned short type, struct in6_addr *data) {
673 assert_return(m, -EINVAL);
675 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR);
679 r = netlink_message_read_internal(m, type, &attr_data, NULL);
682 else if ((size_t)r < sizeof(struct in6_addr))
686 memcpy(data, attr_data, sizeof(struct in6_addr));
691 static int netlink_container_parse(sd_netlink_message *m,
692 struct netlink_container *container,
695 unsigned int rt_len) {
696 _cleanup_free_ struct netlink_attribute *attributes = NULL;
698 attributes = new0(struct netlink_attribute, count);
702 for (; RTA_OK(rta, rt_len); rta = RTA_NEXT(rta, rt_len)) {
705 type = RTA_TYPE(rta);
707 /* if the kernel is newer than the headers we used
708 when building, we ignore out-of-range attributes */
712 if (attributes[type].offset)
713 log_debug("rtnl: message parse - overwriting repeated attribute");
715 attributes[type].offset = (uint8_t *) rta - (uint8_t *) m->hdr;
716 attributes[type].nested = RTA_FLAGS(rta) & NLA_F_NESTED;
717 attributes[type].net_byteorder = RTA_FLAGS(rta) & NLA_F_NET_BYTEORDER;
720 container->attributes = attributes;
722 container->n_attributes = count;
727 int sd_netlink_message_enter_container(sd_netlink_message *m, unsigned short type_id) {
728 const NLType *nl_type;
729 const NLTypeSystem *type_system;
735 assert_return(m, -EINVAL);
736 assert_return(m->n_containers < RTNL_CONTAINER_DEPTH, -EINVAL);
738 r = type_system_get_type(m->containers[m->n_containers].type_system,
744 type = type_get_type(nl_type);
746 if (type == NETLINK_TYPE_NESTED) {
747 r = type_system_get_type_system(m->containers[m->n_containers].type_system,
752 } else if (type == NETLINK_TYPE_UNION) {
753 const NLTypeSystemUnion *type_system_union;
755 r = type_system_get_type_system_union(m->containers[m->n_containers].type_system,
761 switch (type_system_union->match_type) {
762 case NL_MATCH_SIBLING:
766 r = sd_netlink_message_read_string(m, type_system_union->match, &key);
770 r = type_system_union_get_type_system(type_system_union,
778 case NL_MATCH_PROTOCOL:
782 r = sd_rtnl_message_get_family(m, &family);
786 r = type_system_union_protocol_get_type_system(type_system_union,
795 assert_not_reached("sd-netlink: invalid type system union type");
800 r = netlink_message_read_internal(m, type_id, &container, NULL);
808 r = netlink_container_parse(m,
809 &m->containers[m->n_containers],
810 type_system_get_count(type_system),
818 m->containers[m->n_containers].type_system = type_system;
823 int sd_netlink_message_exit_container(sd_netlink_message *m) {
824 assert_return(m, -EINVAL);
825 assert_return(m->sealed, -EINVAL);
826 assert_return(m->n_containers > 0, -EINVAL);
828 free(m->containers[m->n_containers].attributes);
829 m->containers[m->n_containers].attributes = NULL;
830 m->containers[m->n_containers].type_system = NULL;
837 uint32_t rtnl_message_get_serial(sd_netlink_message *m) {
841 return m->hdr->nlmsg_seq;
844 int sd_netlink_message_is_error(sd_netlink_message *m) {
846 assert_return(m->hdr, 0);
848 return m->hdr->nlmsg_type == NLMSG_ERROR;
851 int sd_netlink_message_get_errno(sd_netlink_message *m) {
852 struct nlmsgerr *err;
854 assert_return(m, -EINVAL);
855 assert_return(m->hdr, -EINVAL);
857 if (!sd_netlink_message_is_error(m))
860 err = NLMSG_DATA(m->hdr);
865 int sd_netlink_message_rewind(sd_netlink_message *m) {
866 const NLType *nl_type;
872 assert_return(m, -EINVAL);
874 /* don't allow appending to message once parsed */
876 rtnl_message_seal(m);
878 for (i = 1; i <= m->n_containers; i++) {
879 free(m->containers[i].attributes);
880 m->containers[i].attributes = NULL;
885 if (m->containers[0].attributes) {
886 /* top-level attributes have already been parsed */
892 r = type_system_get_type(&type_system_root, &nl_type, m->hdr->nlmsg_type);
896 type = type_get_type(nl_type);
897 size = type_get_size(nl_type);
899 if (type == NETLINK_TYPE_NESTED) {
900 const NLTypeSystem *type_system;
902 type_get_type_system(nl_type, &type_system);
904 m->containers[0].type_system = type_system;
906 r = netlink_container_parse(m,
907 &m->containers[m->n_containers],
908 type_system_get_count(type_system),
909 (struct rtattr*)((uint8_t*)NLMSG_DATA(m->hdr) + NLMSG_ALIGN(size)),
910 NLMSG_PAYLOAD(m->hdr, size));
918 void rtnl_message_seal(sd_netlink_message *m) {
925 sd_netlink_message *sd_netlink_message_next(sd_netlink_message *m) {
926 assert_return(m, NULL);