diff options
Diffstat (limited to 'src/libsystemd/sd-netlink/netlink-message.c')
| -rw-r--r-- | src/libsystemd/sd-netlink/netlink-message.c | 906 |
1 files changed, 906 insertions, 0 deletions
diff --git a/src/libsystemd/sd-netlink/netlink-message.c b/src/libsystemd/sd-netlink/netlink-message.c new file mode 100644 index 0000000000..87324fc2f7 --- /dev/null +++ b/src/libsystemd/sd-netlink/netlink-message.c @@ -0,0 +1,906 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2013 Tom Gundersen <teg@jklm.no> + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <netinet/in.h> +#include <stdbool.h> +#include <unistd.h> + +#include "util.h" +#include "socket-util.h" +#include "formats-util.h" +#include "refcnt.h" +#include "missing.h" + +#include "sd-netlink.h" +#include "netlink-util.h" +#include "netlink-internal.h" +#include "netlink-types.h" + +#define GET_CONTAINER(m, i) ((i) < (m)->n_containers ? (struct rtattr*)((uint8_t*)(m)->hdr + (m)->container_offsets[i]) : NULL) +#define PUSH_CONTAINER(m, new) (m)->container_offsets[(m)->n_containers ++] = (uint8_t*)(new) - (uint8_t*)(m)->hdr; + +#define RTA_TYPE(rta) ((rta)->rta_type & NLA_TYPE_MASK) + +int message_new_empty(sd_netlink *rtnl, sd_netlink_message **ret) { + sd_netlink_message *m; + + assert_return(ret, -EINVAL); + + /* Note that 'rtnl' is currently unused, if we start using it internally + we must take care to avoid problems due to mutual references between + buses and their queued messages. See sd-bus. + */ + + m = new0(sd_netlink_message, 1); + if (!m) + return -ENOMEM; + + m->n_ref = REFCNT_INIT; + + m->sealed = false; + + *ret = m; + + return 0; +} + +int message_new(sd_netlink *rtnl, sd_netlink_message **ret, uint16_t type) { + _cleanup_netlink_message_unref_ sd_netlink_message *m = NULL; + const NLType *nl_type; + size_t size; + int r; + + r = type_system_get_type(NULL, &nl_type, type); + if (r < 0) + return r; + + r = message_new_empty(rtnl, &m); + if (r < 0) + return r; + + size = NLMSG_SPACE(nl_type->size); + + assert(size >= sizeof(struct nlmsghdr)); + m->hdr = malloc0(size); + if (!m->hdr) + return -ENOMEM; + + m->hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; + + m->container_type_system[0] = nl_type->type_system; + m->hdr->nlmsg_len = size; + m->hdr->nlmsg_type = type; + + *ret = m; + m = NULL; + + return 0; +} + +int sd_netlink_message_request_dump(sd_netlink_message *m, int dump) { + assert_return(m, -EINVAL); + assert_return(m->hdr, -EINVAL); + assert_return(m->hdr->nlmsg_type == RTM_GETLINK || + m->hdr->nlmsg_type == RTM_GETADDR || + m->hdr->nlmsg_type == RTM_GETROUTE || + m->hdr->nlmsg_type == RTM_GETNEIGH, + -EINVAL); + + if (dump) + m->hdr->nlmsg_flags |= NLM_F_DUMP; + else + m->hdr->nlmsg_flags &= ~NLM_F_DUMP; + + return 0; +} + +sd_netlink_message *sd_netlink_message_ref(sd_netlink_message *m) { + if (m) + assert_se(REFCNT_INC(m->n_ref) >= 2); + + return m; +} + +sd_netlink_message *sd_netlink_message_unref(sd_netlink_message *m) { + if (m && REFCNT_DEC(m->n_ref) == 0) { + unsigned i; + + free(m->hdr); + + for (i = 0; i <= m->n_containers; i++) + free(m->rta_offset_tb[i]); + + sd_netlink_message_unref(m->next); + + free(m); + } + + return NULL; +} + +int sd_netlink_message_get_type(sd_netlink_message *m, uint16_t *type) { + assert_return(m, -EINVAL); + assert_return(type, -EINVAL); + + *type = m->hdr->nlmsg_type; + + return 0; +} + +int sd_netlink_message_is_broadcast(sd_netlink_message *m) { + assert_return(m, -EINVAL); + + return m->broadcast; +} + +/* If successful the updated message will be correctly aligned, if + unsuccessful the old message is untouched. */ +static int add_rtattr(sd_netlink_message *m, unsigned short type, const void *data, size_t data_length) { + uint32_t rta_length; + size_t message_length, padding_length; + struct nlmsghdr *new_hdr; + struct rtattr *rta; + char *padding; + unsigned i; + int offset; + + assert(m); + assert(m->hdr); + assert(!m->sealed); + assert(NLMSG_ALIGN(m->hdr->nlmsg_len) == m->hdr->nlmsg_len); + assert(!data || data_length); + + /* get offset of the new attribute */ + offset = m->hdr->nlmsg_len; + + /* get the size of the new rta attribute (with padding at the end) */ + rta_length = RTA_LENGTH(data_length); + + /* get the new message size (with padding at the end) */ + message_length = offset + RTA_ALIGN(rta_length); + + /* realloc to fit the new attribute */ + new_hdr = realloc(m->hdr, message_length); + if (!new_hdr) + return -ENOMEM; + m->hdr = new_hdr; + + /* get pointer to the attribute we are about to add */ + rta = (struct rtattr *) ((uint8_t *) m->hdr + offset); + + /* if we are inside containers, extend them */ + for (i = 0; i < m->n_containers; i++) + GET_CONTAINER(m, i)->rta_len += message_length - offset; + + /* fill in the attribute */ + rta->rta_type = type; + rta->rta_len = rta_length; + if (data) + /* we don't deal with the case where the user lies about the type + * and gives us too little data (so don't do that) + */ + padding = mempcpy(RTA_DATA(rta), data, data_length); + else { + /* if no data was passed, make sure we still initialize the padding + note that we can have data_length > 0 (used by some containers) */ + padding = RTA_DATA(rta); + } + + /* make sure also the padding at the end of the message is initialized */ + padding_length = (uint8_t*)m->hdr + message_length - (uint8_t*)padding; + memzero(padding, padding_length); + + /* update message size */ + m->hdr->nlmsg_len = message_length; + + return offset; +} + +static int message_attribute_has_type(sd_netlink_message *m, uint16_t attribute_type, uint16_t data_type) { + const NLType *type; + int r; + + r = type_system_get_type(m->container_type_system[m->n_containers], &type, attribute_type); + if (r < 0) + return r; + + if (type->type != data_type) + return -EINVAL; + + return type->size; +} + +int sd_netlink_message_append_string(sd_netlink_message *m, unsigned short type, const char *data) { + size_t length, size; + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + assert_return(data, -EINVAL); + + r = message_attribute_has_type(m, type, NLA_STRING); + if (r < 0) + return r; + else + size = (size_t)r; + + if (size) { + length = strnlen(data, size+1); + if (length > size) + return -EINVAL; + } else + length = strlen(data); + + r = add_rtattr(m, type, data, length + 1); + if (r < 0) + return r; + + return 0; +} + +int sd_netlink_message_append_u8(sd_netlink_message *m, unsigned short type, uint8_t data) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + + r = message_attribute_has_type(m, type, NLA_U8); + if (r < 0) + return r; + + r = add_rtattr(m, type, &data, sizeof(uint8_t)); + if (r < 0) + return r; + + return 0; +} + + +int sd_netlink_message_append_u16(sd_netlink_message *m, unsigned short type, uint16_t data) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + + r = message_attribute_has_type(m, type, NLA_U16); + if (r < 0) + return r; + + r = add_rtattr(m, type, &data, sizeof(uint16_t)); + if (r < 0) + return r; + + return 0; +} + +int sd_netlink_message_append_u32(sd_netlink_message *m, unsigned short type, uint32_t data) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + + r = message_attribute_has_type(m, type, NLA_U32); + if (r < 0) + return r; + + r = add_rtattr(m, type, &data, sizeof(uint32_t)); + if (r < 0) + return r; + + return 0; +} + +int sd_netlink_message_append_in_addr(sd_netlink_message *m, unsigned short type, const struct in_addr *data) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + assert_return(data, -EINVAL); + + r = message_attribute_has_type(m, type, NLA_IN_ADDR); + if (r < 0) + return r; + + r = add_rtattr(m, type, data, sizeof(struct in_addr)); + if (r < 0) + return r; + + return 0; +} + +int sd_netlink_message_append_in6_addr(sd_netlink_message *m, unsigned short type, const struct in6_addr *data) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + assert_return(data, -EINVAL); + + r = message_attribute_has_type(m, type, NLA_IN_ADDR); + if (r < 0) + return r; + + r = add_rtattr(m, type, data, sizeof(struct in6_addr)); + if (r < 0) + return r; + + return 0; +} + +int sd_netlink_message_append_ether_addr(sd_netlink_message *m, unsigned short type, const struct ether_addr *data) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + assert_return(data, -EINVAL); + + r = message_attribute_has_type(m, type, NLA_ETHER_ADDR); + if (r < 0) + return r; + + r = add_rtattr(m, type, data, ETH_ALEN); + if (r < 0) + return r; + + return 0; +} + +int sd_netlink_message_append_cache_info(sd_netlink_message *m, unsigned short type, const struct ifa_cacheinfo *info) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + assert_return(info, -EINVAL); + + r = message_attribute_has_type(m, type, NLA_CACHE_INFO); + if (r < 0) + return r; + + r = add_rtattr(m, type, info, sizeof(struct ifa_cacheinfo)); + if (r < 0) + return r; + + return 0; +} + +int sd_netlink_message_open_container(sd_netlink_message *m, unsigned short type) { + size_t size; + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + assert_return(m->n_containers < RTNL_CONTAINER_DEPTH, -ERANGE); + + r = message_attribute_has_type(m, type, NLA_NESTED); + if (r < 0) { + const NLTypeSystemUnion *type_system_union; + int family; + + r = message_attribute_has_type(m, type, NLA_UNION); + if (r < 0) + return r; + size = (size_t) r; + + r = sd_rtnl_message_get_family(m, &family); + if (r < 0) + return r; + + r = type_system_get_type_system_union(m->container_type_system[m->n_containers], &type_system_union, type); + if (r < 0) + return r; + + r = type_system_union_protocol_get_type_system(type_system_union, + &m->container_type_system[m->n_containers + 1], + family); + if (r < 0) + return r; + } else { + size = (size_t)r; + + r = type_system_get_type_system(m->container_type_system[m->n_containers], + &m->container_type_system[m->n_containers + 1], + type); + if (r < 0) + return r; + } + + r = add_rtattr(m, type | NLA_F_NESTED, NULL, size); + if (r < 0) + return r; + + m->container_offsets[m->n_containers ++] = r; + + return 0; +} + +int sd_netlink_message_open_container_union(sd_netlink_message *m, unsigned short type, const char *key) { + const NLTypeSystemUnion *type_system_union; + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + + r = type_system_get_type_system_union(m->container_type_system[m->n_containers], &type_system_union, type); + if (r < 0) + return r; + + r = type_system_union_get_type_system(type_system_union, + &m->container_type_system[m->n_containers + 1], + key); + if (r < 0) + return r; + + r = sd_netlink_message_append_string(m, type_system_union->match, key); + if (r < 0) + return r; + + /* do we evere need non-null size */ + r = add_rtattr(m, type, NULL, 0); + if (r < 0) + return r; + + m->container_offsets[m->n_containers ++] = r; + + return 0; +} + + +int sd_netlink_message_close_container(sd_netlink_message *m) { + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + assert_return(m->n_containers > 0, -EINVAL); + + m->container_type_system[m->n_containers] = NULL; + m->n_containers --; + + return 0; +} + +int rtnl_message_read_internal(sd_netlink_message *m, unsigned short type, void **data) { + struct rtattr *rta; + + assert_return(m, -EINVAL); + assert_return(m->sealed, -EPERM); + assert_return(data, -EINVAL); + assert(m->n_containers <= RTNL_CONTAINER_DEPTH); + assert(m->rta_offset_tb[m->n_containers]); + assert(type < m->rta_tb_size[m->n_containers]); + + if(!m->rta_offset_tb[m->n_containers][type]) + return -ENODATA; + + rta = (struct rtattr*)((uint8_t *) m->hdr + m->rta_offset_tb[m->n_containers][type]); + + *data = RTA_DATA(rta); + + return RTA_PAYLOAD(rta); +} + +int sd_netlink_message_read_string(sd_netlink_message *m, unsigned short type, const char **data) { + int r; + void *attr_data; + + assert_return(m, -EINVAL); + + r = message_attribute_has_type(m, type, NLA_STRING); + if (r < 0) + return r; + + r = rtnl_message_read_internal(m, type, &attr_data); + if (r < 0) + return r; + else if (strnlen(attr_data, r) >= (size_t) r) + return -EIO; + + if (data) + *data = (const char *) attr_data; + + return 0; +} + +int sd_netlink_message_read_u8(sd_netlink_message *m, unsigned short type, uint8_t *data) { + int r; + void *attr_data; + + assert_return(m, -EINVAL); + + r = message_attribute_has_type(m, type, NLA_U8); + if (r < 0) + return r; + + r = rtnl_message_read_internal(m, type, &attr_data); + if (r < 0) + return r; + else if ((size_t) r < sizeof(uint8_t)) + return -EIO; + + if (data) + *data = *(uint8_t *) attr_data; + + return 0; +} + +int sd_netlink_message_read_u16(sd_netlink_message *m, unsigned short type, uint16_t *data) { + int r; + void *attr_data; + + assert_return(m, -EINVAL); + + r = message_attribute_has_type(m, type, NLA_U16); + if (r < 0) + return r; + + r = rtnl_message_read_internal(m, type, &attr_data); + if (r < 0) + return r; + else if ((size_t) r < sizeof(uint16_t)) + return -EIO; + + if (data) + *data = *(uint16_t *) attr_data; + + return 0; +} + +int sd_netlink_message_read_u32(sd_netlink_message *m, unsigned short type, uint32_t *data) { + int r; + void *attr_data; + + assert_return(m, -EINVAL); + + r = message_attribute_has_type(m, type, NLA_U32); + if (r < 0) + return r; + + r = rtnl_message_read_internal(m, type, &attr_data); + if (r < 0) + return r; + else if ((size_t)r < sizeof(uint32_t)) + return -EIO; + + if (data) + *data = *(uint32_t *) attr_data; + + return 0; +} + +int sd_netlink_message_read_ether_addr(sd_netlink_message *m, unsigned short type, struct ether_addr *data) { + int r; + void *attr_data; + + assert_return(m, -EINVAL); + + r = message_attribute_has_type(m, type, NLA_ETHER_ADDR); + if (r < 0) + return r; + + r = rtnl_message_read_internal(m, type, &attr_data); + if (r < 0) + return r; + else if ((size_t)r < sizeof(struct ether_addr)) + return -EIO; + + if (data) + memcpy(data, attr_data, sizeof(struct ether_addr)); + + return 0; +} + +int sd_netlink_message_read_cache_info(sd_netlink_message *m, unsigned short type, struct ifa_cacheinfo *info) { + int r; + void *attr_data; + + assert_return(m, -EINVAL); + + r = message_attribute_has_type(m, type, NLA_CACHE_INFO); + if (r < 0) + return r; + + r = rtnl_message_read_internal(m, type, &attr_data); + if (r < 0) + return r; + else if ((size_t)r < sizeof(struct ifa_cacheinfo)) + return -EIO; + + if (info) + memcpy(info, attr_data, sizeof(struct ifa_cacheinfo)); + + return 0; +} + +int sd_netlink_message_read_in_addr(sd_netlink_message *m, unsigned short type, struct in_addr *data) { + int r; + void *attr_data; + + assert_return(m, -EINVAL); + + r = message_attribute_has_type(m, type, NLA_IN_ADDR); + if (r < 0) + return r; + + r = rtnl_message_read_internal(m, type, &attr_data); + if (r < 0) + return r; + else if ((size_t)r < sizeof(struct in_addr)) + return -EIO; + + if (data) + memcpy(data, attr_data, sizeof(struct in_addr)); + + return 0; +} + +int sd_netlink_message_read_in6_addr(sd_netlink_message *m, unsigned short type, struct in6_addr *data) { + int r; + void *attr_data; + + assert_return(m, -EINVAL); + + r = message_attribute_has_type(m, type, NLA_IN_ADDR); + if (r < 0) + return r; + + r = rtnl_message_read_internal(m, type, &attr_data); + if (r < 0) + return r; + else if ((size_t)r < sizeof(struct in6_addr)) + return -EIO; + + if (data) + memcpy(data, attr_data, sizeof(struct in6_addr)); + + return 0; +} + +int sd_netlink_message_enter_container(sd_netlink_message *m, unsigned short type) { + const NLType *nl_type; + const NLTypeSystem *type_system; + void *container; + size_t size; + int r; + + assert_return(m, -EINVAL); + assert_return(m->n_containers < RTNL_CONTAINER_DEPTH, -EINVAL); + + r = type_system_get_type(m->container_type_system[m->n_containers], + &nl_type, + type); + if (r < 0) + return r; + + if (nl_type->type == NLA_NESTED) { + r = type_system_get_type_system(m->container_type_system[m->n_containers], + &type_system, + type); + if (r < 0) + return r; + } else if (nl_type->type == NLA_UNION) { + const NLTypeSystemUnion *type_system_union; + + r = type_system_get_type_system_union(m->container_type_system[m->n_containers], + &type_system_union, + type); + if (r < 0) + return r; + + switch (type_system_union->match_type) { + case NL_MATCH_SIBLING: + { + const char *key; + + r = sd_netlink_message_read_string(m, type_system_union->match, &key); + if (r < 0) + return r; + + r = type_system_union_get_type_system(type_system_union, + &type_system, + key); + if (r < 0) + return r; + + break; + } + case NL_MATCH_PROTOCOL: + { + int family; + + r = sd_rtnl_message_get_family(m, &family); + if (r < 0) + return r; + + r = type_system_union_protocol_get_type_system(type_system_union, + &type_system, + family); + if (r < 0) + return r; + + break; + } + default: + assert_not_reached("sd-netlink: invalid type system union type"); + } + } else + return -EINVAL; + + r = rtnl_message_read_internal(m, type, &container); + if (r < 0) + return r; + else + size = (size_t)r; + + m->n_containers ++; + + r = rtnl_message_parse(m, + &m->rta_offset_tb[m->n_containers], + &m->rta_tb_size[m->n_containers], + type_system->max, + container, + size); + if (r < 0) { + m->n_containers --; + return r; + } + + m->container_type_system[m->n_containers] = type_system; + + return 0; +} + +int sd_netlink_message_exit_container(sd_netlink_message *m) { + assert_return(m, -EINVAL); + assert_return(m->sealed, -EINVAL); + assert_return(m->n_containers > 0, -EINVAL); + + free(m->rta_offset_tb[m->n_containers]); + m->rta_offset_tb[m->n_containers] = NULL; + m->container_type_system[m->n_containers] = NULL; + + m->n_containers --; + + return 0; +} + +uint32_t rtnl_message_get_serial(sd_netlink_message *m) { + assert(m); + assert(m->hdr); + + return m->hdr->nlmsg_seq; +} + +int sd_netlink_message_is_error(sd_netlink_message *m) { + assert_return(m, 0); + assert_return(m->hdr, 0); + + return m->hdr->nlmsg_type == NLMSG_ERROR; +} + +int sd_netlink_message_get_errno(sd_netlink_message *m) { + struct nlmsgerr *err; + + assert_return(m, -EINVAL); + assert_return(m->hdr, -EINVAL); + + if (!sd_netlink_message_is_error(m)) + return 0; + + err = NLMSG_DATA(m->hdr); + + return err->error; +} + +int rtnl_message_parse(sd_netlink_message *m, + size_t **rta_offset_tb, + unsigned short *rta_tb_size, + int max, + struct rtattr *rta, + unsigned int rt_len) { + unsigned short type; + size_t *tb; + + tb = new0(size_t, max + 1); + if(!tb) + return -ENOMEM; + + *rta_tb_size = max + 1; + + for (; RTA_OK(rta, rt_len); rta = RTA_NEXT(rta, rt_len)) { + type = RTA_TYPE(rta); + + /* if the kernel is newer than the headers we used + when building, we ignore out-of-range attributes + */ + if (type > max) + continue; + + if (tb[type]) + log_debug("rtnl: message parse - overwriting repeated attribute"); + + tb[type] = (uint8_t *) rta - (uint8_t *) m->hdr; + } + + *rta_offset_tb = tb; + + return 0; +} + +int sd_netlink_message_rewind(sd_netlink_message *m) { + const NLType *type; + unsigned i; + int r; + + assert_return(m, -EINVAL); + + /* don't allow appending to message once parsed */ + if (!m->sealed) + rtnl_message_seal(m); + + for (i = 1; i <= m->n_containers; i++) { + free(m->rta_offset_tb[i]); + m->rta_offset_tb[i] = NULL; + m->rta_tb_size[i] = 0; + m->container_type_system[i] = NULL; + } + + m->n_containers = 0; + + if (m->rta_offset_tb[0]) { + /* top-level attributes have already been parsed */ + return 0; + } + + assert(m->hdr); + + r = type_system_get_type(NULL, &type, m->hdr->nlmsg_type); + if (r < 0) + return r; + + if (type->type == NLA_NESTED) { + const NLTypeSystem *type_system = type->type_system; + + assert(type_system); + + m->container_type_system[0] = type_system; + + r = rtnl_message_parse(m, + &m->rta_offset_tb[m->n_containers], + &m->rta_tb_size[m->n_containers], + type_system->max, + (struct rtattr*)((uint8_t*)NLMSG_DATA(m->hdr) + + NLMSG_ALIGN(type->size)), + NLMSG_PAYLOAD(m->hdr, type->size)); + if (r < 0) + return r; + } + + return 0; +} + +void rtnl_message_seal(sd_netlink_message *m) { + assert(m); + assert(!m->sealed); + + m->sealed = true; +} + +sd_netlink_message *sd_netlink_message_next(sd_netlink_message *m) { + assert_return(m, NULL); + + return m->next; +} |