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)->container_offsets[i]) : 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)
42 int message_new_empty(sd_netlink *rtnl, sd_netlink_message **ret) {
43 sd_netlink_message *m;
45 assert_return(ret, -EINVAL);
47 /* Note that 'rtnl' is currently unused, if we start using it internally
48 we must take care to avoid problems due to mutual references between
49 buses and their queued messages. See sd-bus.
52 m = new0(sd_netlink_message, 1);
56 m->n_ref = REFCNT_INIT;
65 int message_new(sd_netlink *rtnl, sd_netlink_message **ret, uint16_t type) {
66 _cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
67 const NLType *nl_type;
71 r = type_system_get_type(&type_system_root, &nl_type, type);
75 if (type_get_type(nl_type) != NETLINK_TYPE_NESTED)
78 r = message_new_empty(rtnl, &m);
82 size = NLMSG_SPACE(type_get_size(nl_type));
84 assert(size >= sizeof(struct nlmsghdr));
85 m->hdr = malloc0(size);
89 m->hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
91 type_get_type_system(nl_type, &m->container_type_system[0]);
92 m->hdr->nlmsg_len = size;
93 m->hdr->nlmsg_type = type;
101 int sd_netlink_message_request_dump(sd_netlink_message *m, int dump) {
102 assert_return(m, -EINVAL);
103 assert_return(m->hdr, -EINVAL);
104 assert_return(m->hdr->nlmsg_type == RTM_GETLINK ||
105 m->hdr->nlmsg_type == RTM_GETADDR ||
106 m->hdr->nlmsg_type == RTM_GETROUTE ||
107 m->hdr->nlmsg_type == RTM_GETNEIGH,
111 m->hdr->nlmsg_flags |= NLM_F_DUMP;
113 m->hdr->nlmsg_flags &= ~NLM_F_DUMP;
118 sd_netlink_message *sd_netlink_message_ref(sd_netlink_message *m) {
120 assert_se(REFCNT_INC(m->n_ref) >= 2);
125 sd_netlink_message *sd_netlink_message_unref(sd_netlink_message *m) {
126 if (m && REFCNT_DEC(m->n_ref) == 0) {
131 for (i = 0; i <= m->n_containers; i++)
132 free(m->rta_offset_tb[i]);
134 sd_netlink_message_unref(m->next);
142 int sd_netlink_message_get_type(sd_netlink_message *m, uint16_t *type) {
143 assert_return(m, -EINVAL);
144 assert_return(type, -EINVAL);
146 *type = m->hdr->nlmsg_type;
151 int sd_netlink_message_is_broadcast(sd_netlink_message *m) {
152 assert_return(m, -EINVAL);
157 /* If successful the updated message will be correctly aligned, if
158 unsuccessful the old message is untouched. */
159 static int add_rtattr(sd_netlink_message *m, unsigned short type, const void *data, size_t data_length) {
161 size_t message_length, padding_length;
162 struct nlmsghdr *new_hdr;
171 assert(NLMSG_ALIGN(m->hdr->nlmsg_len) == m->hdr->nlmsg_len);
172 assert(!data || data_length);
174 /* get offset of the new attribute */
175 offset = m->hdr->nlmsg_len;
177 /* get the size of the new rta attribute (with padding at the end) */
178 rta_length = RTA_LENGTH(data_length);
180 /* get the new message size (with padding at the end) */
181 message_length = offset + RTA_ALIGN(rta_length);
183 /* realloc to fit the new attribute */
184 new_hdr = realloc(m->hdr, message_length);
189 /* get pointer to the attribute we are about to add */
190 rta = (struct rtattr *) ((uint8_t *) m->hdr + offset);
192 /* if we are inside containers, extend them */
193 for (i = 0; i < m->n_containers; i++)
194 GET_CONTAINER(m, i)->rta_len += message_length - offset;
196 /* fill in the attribute */
197 rta->rta_type = type;
198 rta->rta_len = rta_length;
200 /* we don't deal with the case where the user lies about the type
201 * and gives us too little data (so don't do that)
203 padding = mempcpy(RTA_DATA(rta), data, data_length);
205 /* if no data was passed, make sure we still initialize the padding
206 note that we can have data_length > 0 (used by some containers) */
207 padding = RTA_DATA(rta);
210 /* make sure also the padding at the end of the message is initialized */
211 padding_length = (uint8_t*)m->hdr + message_length - (uint8_t*)padding;
212 memzero(padding, padding_length);
214 /* update message size */
215 m->hdr->nlmsg_len = message_length;
220 static int message_attribute_has_type(sd_netlink_message *m, size_t *out_size, uint16_t attribute_type, uint16_t data_type) {
226 r = type_system_get_type(m->container_type_system[m->n_containers], &type, attribute_type);
230 if (type_get_type(type) != data_type)
234 *out_size = type_get_size(type);
238 int sd_netlink_message_append_string(sd_netlink_message *m, unsigned short type, const char *data) {
242 assert_return(m, -EINVAL);
243 assert_return(!m->sealed, -EPERM);
244 assert_return(data, -EINVAL);
246 r = message_attribute_has_type(m, &size, type, NETLINK_TYPE_STRING);
251 length = strnlen(data, size+1);
255 length = strlen(data);
257 r = add_rtattr(m, type, data, length + 1);
264 int sd_netlink_message_append_u8(sd_netlink_message *m, unsigned short type, uint8_t data) {
267 assert_return(m, -EINVAL);
268 assert_return(!m->sealed, -EPERM);
270 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U8);
274 r = add_rtattr(m, type, &data, sizeof(uint8_t));
282 int sd_netlink_message_append_u16(sd_netlink_message *m, unsigned short type, uint16_t data) {
285 assert_return(m, -EINVAL);
286 assert_return(!m->sealed, -EPERM);
288 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U16);
292 r = add_rtattr(m, type, &data, sizeof(uint16_t));
299 int sd_netlink_message_append_u32(sd_netlink_message *m, unsigned short type, uint32_t data) {
302 assert_return(m, -EINVAL);
303 assert_return(!m->sealed, -EPERM);
305 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U32);
309 r = add_rtattr(m, type, &data, sizeof(uint32_t));
316 int sd_netlink_message_append_in_addr(sd_netlink_message *m, unsigned short type, const struct in_addr *data) {
319 assert_return(m, -EINVAL);
320 assert_return(!m->sealed, -EPERM);
321 assert_return(data, -EINVAL);
323 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR);
327 r = add_rtattr(m, type, data, sizeof(struct in_addr));
334 int sd_netlink_message_append_in6_addr(sd_netlink_message *m, unsigned short type, const struct in6_addr *data) {
337 assert_return(m, -EINVAL);
338 assert_return(!m->sealed, -EPERM);
339 assert_return(data, -EINVAL);
341 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR);
345 r = add_rtattr(m, type, data, sizeof(struct in6_addr));
352 int sd_netlink_message_append_ether_addr(sd_netlink_message *m, unsigned short type, const struct ether_addr *data) {
355 assert_return(m, -EINVAL);
356 assert_return(!m->sealed, -EPERM);
357 assert_return(data, -EINVAL);
359 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_ETHER_ADDR);
363 r = add_rtattr(m, type, data, ETH_ALEN);
370 int sd_netlink_message_append_cache_info(sd_netlink_message *m, unsigned short type, const struct ifa_cacheinfo *info) {
373 assert_return(m, -EINVAL);
374 assert_return(!m->sealed, -EPERM);
375 assert_return(info, -EINVAL);
377 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_CACHE_INFO);
381 r = add_rtattr(m, type, info, sizeof(struct ifa_cacheinfo));
388 int sd_netlink_message_open_container(sd_netlink_message *m, unsigned short type) {
392 assert_return(m, -EINVAL);
393 assert_return(!m->sealed, -EPERM);
394 assert_return(m->n_containers < RTNL_CONTAINER_DEPTH, -ERANGE);
396 r = message_attribute_has_type(m, &size, type, NETLINK_TYPE_NESTED);
398 const NLTypeSystemUnion *type_system_union;
401 r = message_attribute_has_type(m, &size, type, NETLINK_TYPE_UNION);
405 r = sd_rtnl_message_get_family(m, &family);
409 r = type_system_get_type_system_union(m->container_type_system[m->n_containers], &type_system_union, type);
413 r = type_system_union_protocol_get_type_system(type_system_union,
414 &m->container_type_system[m->n_containers + 1],
419 r = type_system_get_type_system(m->container_type_system[m->n_containers],
420 &m->container_type_system[m->n_containers + 1],
426 r = add_rtattr(m, type | NLA_F_NESTED, NULL, size);
430 m->container_offsets[m->n_containers ++] = r;
435 int sd_netlink_message_open_container_union(sd_netlink_message *m, unsigned short type, const char *key) {
436 const NLTypeSystemUnion *type_system_union;
439 assert_return(m, -EINVAL);
440 assert_return(!m->sealed, -EPERM);
442 r = type_system_get_type_system_union(m->container_type_system[m->n_containers], &type_system_union, type);
446 r = type_system_union_get_type_system(type_system_union,
447 &m->container_type_system[m->n_containers + 1],
452 r = sd_netlink_message_append_string(m, type_system_union->match, key);
456 /* do we evere need non-null size */
457 r = add_rtattr(m, type | NLA_F_NESTED, NULL, 0);
461 m->container_offsets[m->n_containers ++] = r;
467 int sd_netlink_message_close_container(sd_netlink_message *m) {
468 assert_return(m, -EINVAL);
469 assert_return(!m->sealed, -EPERM);
470 assert_return(m->n_containers > 0, -EINVAL);
472 m->container_type_system[m->n_containers] = NULL;
478 static int netlink_message_read_internal(sd_netlink_message *m, unsigned short type, void **data) {
481 assert_return(m, -EINVAL);
482 assert_return(m->sealed, -EPERM);
483 assert_return(data, -EINVAL);
484 assert(m->n_containers <= RTNL_CONTAINER_DEPTH);
485 assert(m->rta_offset_tb[m->n_containers]);
486 assert(type < m->rta_tb_size[m->n_containers]);
488 if(!m->rta_offset_tb[m->n_containers][type])
491 rta = (struct rtattr*)((uint8_t *) m->hdr + m->rta_offset_tb[m->n_containers][type]);
493 *data = RTA_DATA(rta);
495 return RTA_PAYLOAD(rta);
498 int sd_netlink_message_read_string(sd_netlink_message *m, unsigned short type, const char **data) {
502 assert_return(m, -EINVAL);
504 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_STRING);
508 r = netlink_message_read_internal(m, type, &attr_data);
511 else if (strnlen(attr_data, r) >= (size_t) r)
515 *data = (const char *) attr_data;
520 int sd_netlink_message_read_u8(sd_netlink_message *m, unsigned short type, uint8_t *data) {
524 assert_return(m, -EINVAL);
526 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U8);
530 r = netlink_message_read_internal(m, type, &attr_data);
533 else if ((size_t) r < sizeof(uint8_t))
537 *data = *(uint8_t *) attr_data;
542 int sd_netlink_message_read_u16(sd_netlink_message *m, unsigned short type, uint16_t *data) {
546 assert_return(m, -EINVAL);
548 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U16);
552 r = netlink_message_read_internal(m, type, &attr_data);
555 else if ((size_t) r < sizeof(uint16_t))
559 *data = *(uint16_t *) attr_data;
564 int sd_netlink_message_read_u32(sd_netlink_message *m, unsigned short type, uint32_t *data) {
568 assert_return(m, -EINVAL);
570 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U32);
574 r = netlink_message_read_internal(m, type, &attr_data);
577 else if ((size_t)r < sizeof(uint32_t))
581 *data = *(uint32_t *) attr_data;
586 int sd_netlink_message_read_ether_addr(sd_netlink_message *m, unsigned short type, struct ether_addr *data) {
590 assert_return(m, -EINVAL);
592 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_ETHER_ADDR);
596 r = netlink_message_read_internal(m, type, &attr_data);
599 else if ((size_t)r < sizeof(struct ether_addr))
603 memcpy(data, attr_data, sizeof(struct ether_addr));
608 int sd_netlink_message_read_cache_info(sd_netlink_message *m, unsigned short type, struct ifa_cacheinfo *info) {
612 assert_return(m, -EINVAL);
614 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_CACHE_INFO);
618 r = netlink_message_read_internal(m, type, &attr_data);
621 else if ((size_t)r < sizeof(struct ifa_cacheinfo))
625 memcpy(info, attr_data, sizeof(struct ifa_cacheinfo));
630 int sd_netlink_message_read_in_addr(sd_netlink_message *m, unsigned short type, struct in_addr *data) {
634 assert_return(m, -EINVAL);
636 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR);
640 r = netlink_message_read_internal(m, type, &attr_data);
643 else if ((size_t)r < sizeof(struct in_addr))
647 memcpy(data, attr_data, sizeof(struct in_addr));
652 int sd_netlink_message_read_in6_addr(sd_netlink_message *m, unsigned short type, struct in6_addr *data) {
656 assert_return(m, -EINVAL);
658 r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR);
662 r = netlink_message_read_internal(m, type, &attr_data);
665 else if ((size_t)r < sizeof(struct in6_addr))
669 memcpy(data, attr_data, sizeof(struct in6_addr));
674 static int netlink_message_parse(sd_netlink_message *m,
675 size_t **rta_offset_tb,
676 unsigned short *rta_tb_size,
679 unsigned int rt_len) {
683 tb = new0(size_t, count);
687 *rta_tb_size = count;
689 for (; RTA_OK(rta, rt_len); rta = RTA_NEXT(rta, rt_len)) {
690 type = RTA_TYPE(rta);
692 /* if the kernel is newer than the headers we used
693 when building, we ignore out-of-range attributes
699 log_debug("rtnl: message parse - overwriting repeated attribute");
701 tb[type] = (uint8_t *) rta - (uint8_t *) m->hdr;
709 int sd_netlink_message_enter_container(sd_netlink_message *m, unsigned short type_id) {
710 const NLType *nl_type;
711 const NLTypeSystem *type_system;
717 assert_return(m, -EINVAL);
718 assert_return(m->n_containers < RTNL_CONTAINER_DEPTH, -EINVAL);
720 r = type_system_get_type(m->container_type_system[m->n_containers],
726 type = type_get_type(nl_type);
728 if (type == NETLINK_TYPE_NESTED) {
729 r = type_system_get_type_system(m->container_type_system[m->n_containers],
734 } else if (type == NETLINK_TYPE_UNION) {
735 const NLTypeSystemUnion *type_system_union;
737 r = type_system_get_type_system_union(m->container_type_system[m->n_containers],
743 switch (type_system_union->match_type) {
744 case NL_MATCH_SIBLING:
748 r = sd_netlink_message_read_string(m, type_system_union->match, &key);
752 r = type_system_union_get_type_system(type_system_union,
760 case NL_MATCH_PROTOCOL:
764 r = sd_rtnl_message_get_family(m, &family);
768 r = type_system_union_protocol_get_type_system(type_system_union,
777 assert_not_reached("sd-netlink: invalid type system union type");
782 r = netlink_message_read_internal(m, type_id, &container);
790 r = netlink_message_parse(m,
791 &m->rta_offset_tb[m->n_containers],
792 &m->rta_tb_size[m->n_containers],
793 type_system_get_count(type_system),
801 m->container_type_system[m->n_containers] = type_system;
806 int sd_netlink_message_exit_container(sd_netlink_message *m) {
807 assert_return(m, -EINVAL);
808 assert_return(m->sealed, -EINVAL);
809 assert_return(m->n_containers > 0, -EINVAL);
811 free(m->rta_offset_tb[m->n_containers]);
812 m->rta_offset_tb[m->n_containers] = NULL;
813 m->container_type_system[m->n_containers] = NULL;
820 uint32_t rtnl_message_get_serial(sd_netlink_message *m) {
824 return m->hdr->nlmsg_seq;
827 int sd_netlink_message_is_error(sd_netlink_message *m) {
829 assert_return(m->hdr, 0);
831 return m->hdr->nlmsg_type == NLMSG_ERROR;
834 int sd_netlink_message_get_errno(sd_netlink_message *m) {
835 struct nlmsgerr *err;
837 assert_return(m, -EINVAL);
838 assert_return(m->hdr, -EINVAL);
840 if (!sd_netlink_message_is_error(m))
843 err = NLMSG_DATA(m->hdr);
848 int sd_netlink_message_rewind(sd_netlink_message *m) {
849 const NLType *nl_type;
855 assert_return(m, -EINVAL);
857 /* don't allow appending to message once parsed */
859 rtnl_message_seal(m);
861 for (i = 1; i <= m->n_containers; i++) {
862 free(m->rta_offset_tb[i]);
863 m->rta_offset_tb[i] = NULL;
864 m->rta_tb_size[i] = 0;
865 m->container_type_system[i] = NULL;
870 if (m->rta_offset_tb[0]) {
871 /* top-level attributes have already been parsed */
877 r = type_system_get_type(&type_system_root, &nl_type, m->hdr->nlmsg_type);
881 type = type_get_type(nl_type);
882 size = type_get_size(nl_type);
884 if (type == NETLINK_TYPE_NESTED) {
885 const NLTypeSystem *type_system;
887 type_get_type_system(nl_type, &type_system);
889 m->container_type_system[0] = type_system;
891 r = netlink_message_parse(m,
892 &m->rta_offset_tb[m->n_containers],
893 &m->rta_tb_size[m->n_containers],
894 type_system_get_count(type_system),
895 (struct rtattr*)((uint8_t*)NLMSG_DATA(m->hdr) + NLMSG_ALIGN(size)),
896 NLMSG_PAYLOAD(m->hdr, size));
904 void rtnl_message_seal(sd_netlink_message *m) {
911 sd_netlink_message *sd_netlink_message_next(sd_netlink_message *m) {
912 assert_return(m, NULL);