diff options
Diffstat (limited to '')
| -rw-r--r-- | src/libsystemd/sd-netlink/netlink-message.c | 1320 |
1 files changed, 1320 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 0000000..bd56536 --- /dev/null +++ b/src/libsystemd/sd-netlink/netlink-message.c @@ -0,0 +1,1320 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <netinet/in.h> +#include <stdbool.h> +#include <unistd.h> + +#include "sd-netlink.h" + +#include "alloc-util.h" +#include "format-util.h" +#include "memory-util.h" +#include "netlink-internal.h" +#include "netlink-types.h" +#include "netlink-util.h" +#include "socket-util.h" +#include "strv.h" + +#define GET_CONTAINER(m, i) ((struct rtattr*)((uint8_t*)(m)->hdr + (m)->containers[i].offset)) + +#define RTA_TYPE(rta) ((rta)->rta_type & NLA_TYPE_MASK) +#define RTA_FLAGS(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 = new(sd_netlink_message, 1); + if (!m) + return -ENOMEM; + + *m = (sd_netlink_message) { + .n_ref = 1, + .protocol = rtnl->protocol, + .sealed = false, + }; + + *ret = m; + + return 0; +} + +int message_new(sd_netlink *rtnl, sd_netlink_message **ret, uint16_t type) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL; + const NLType *nl_type; + size_t size; + int r; + + assert_return(rtnl, -EINVAL); + + r = type_system_root_get_type(rtnl, &nl_type, type); + if (r < 0) + return r; + + if (type_get_type(nl_type) != NETLINK_TYPE_NESTED) + return -EINVAL; + + r = message_new_empty(rtnl, &m); + if (r < 0) + return r; + + size = NLMSG_SPACE(type_get_size(nl_type)); + + assert(size >= sizeof(struct nlmsghdr)); + m->hdr = malloc0(size); + if (!m->hdr) + return -ENOMEM; + + m->hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; + + type_get_type_system(nl_type, &m->containers[0].type_system); + m->hdr->nlmsg_len = size; + m->hdr->nlmsg_type = type; + + *ret = TAKE_PTR(m); + + 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(IN_SET(m->hdr->nlmsg_type, + RTM_GETLINK, RTM_GETLINKPROP, RTM_GETADDR, RTM_GETROUTE, RTM_GETNEIGH, + RTM_GETRULE, RTM_GETADDRLABEL, RTM_GETNEXTHOP), -EINVAL); + + SET_FLAG(m->hdr->nlmsg_flags, NLM_F_DUMP, dump); + + return 0; +} + +DEFINE_TRIVIAL_REF_FUNC(sd_netlink_message, sd_netlink_message); + +sd_netlink_message *sd_netlink_message_unref(sd_netlink_message *m) { + while (m && --m->n_ref == 0) { + unsigned i; + + free(m->hdr); + + for (i = 0; i <= m->n_containers; i++) + free(m->containers[i].attributes); + + sd_netlink_message *t = m; + m = m->next; + free(t); + } + + return NULL; +} + +int sd_netlink_message_get_type(const 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_set_flags(sd_netlink_message *m, uint16_t flags) { + assert_return(m, -EINVAL); + assert_return(flags, -EINVAL); + + m->hdr->nlmsg_flags = flags; + + return 0; +} + +int sd_netlink_message_is_broadcast(const 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) { + size_t message_length; + struct nlmsghdr *new_hdr; + struct rtattr *rta; + 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 > 0); + + /* get the new message size (with padding at the end) */ + message_length = m->hdr->nlmsg_len + RTA_SPACE(data_length); + + /* buffer should be smaller than both one page or 8K to be accepted by the kernel */ + if (message_length > MIN(page_size(), 8192UL)) + return -ENOBUFS; + + /* 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 + m->hdr->nlmsg_len); + + rtattr_append_attribute_internal(rta, type, data, data_length); + + /* if we are inside containers, extend them */ + for (i = 0; i < m->n_containers; i++) + GET_CONTAINER(m, i)->rta_len += RTA_SPACE(data_length); + + /* update message size */ + offset = m->hdr->nlmsg_len; + m->hdr->nlmsg_len = message_length; + + /* return old message size */ + return offset; +} + +static int message_attribute_has_type(sd_netlink_message *m, size_t *out_size, uint16_t attribute_type, uint16_t data_type) { + const NLType *type; + int r; + + assert(m); + + r = type_system_get_type(m->containers[m->n_containers].type_system, &type, attribute_type); + if (r < 0) + return r; + + if (type_get_type(type) != data_type) + return -EINVAL; + + if (out_size) + *out_size = type_get_size(type); + return 0; +} + +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, &size, type, NETLINK_TYPE_STRING); + if (r < 0) + return 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_strv(sd_netlink_message *m, unsigned short type, char * const *data) { + size_t length, size; + char * const *p; + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + assert_return(data, -EINVAL); + + r = message_attribute_has_type(m, &size, type, NETLINK_TYPE_STRING); + if (r < 0) + return r; + + STRV_FOREACH(p, data) { + if (size) { + length = strnlen(*p, size+1); + if (length > size) + return -EINVAL; + } else + length = strlen(*p); + + r = add_rtattr(m, type, *p, length + 1); + if (r < 0) + return r; + } + + return 0; +} + +int sd_netlink_message_append_flag(sd_netlink_message *m, unsigned short type) { + size_t size; + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + + r = message_attribute_has_type(m, &size, type, NETLINK_TYPE_FLAG); + if (r < 0) + return r; + + r = add_rtattr(m, type, NULL, 0); + 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, NULL, type, NETLINK_TYPE_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, NULL, type, NETLINK_TYPE_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, NULL, type, NETLINK_TYPE_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_u64(sd_netlink_message *m, unsigned short type, uint64_t data) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + + r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U64); + if (r < 0) + return r; + + r = add_rtattr(m, type, &data, sizeof(uint64_t)); + if (r < 0) + return r; + + return 0; +} + +int sd_netlink_message_append_s8(sd_netlink_message *m, unsigned short type, int8_t data) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + + r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_S8); + if (r < 0) + return r; + + r = add_rtattr(m, type, &data, sizeof(int8_t)); + if (r < 0) + return r; + + return 0; +} + +int sd_netlink_message_append_s16(sd_netlink_message *m, unsigned short type, int16_t data) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + + r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_S16); + if (r < 0) + return r; + + r = add_rtattr(m, type, &data, sizeof(int16_t)); + if (r < 0) + return r; + + return 0; +} + +int sd_netlink_message_append_s32(sd_netlink_message *m, unsigned short type, int32_t data) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + + r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_S32); + if (r < 0) + return r; + + r = add_rtattr(m, type, &data, sizeof(int32_t)); + if (r < 0) + return r; + + return 0; +} + +int sd_netlink_message_append_s64(sd_netlink_message *m, unsigned short type, int64_t data) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + + r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_S64); + if (r < 0) + return r; + + r = add_rtattr(m, type, &data, sizeof(int64_t)); + if (r < 0) + return r; + + return 0; +} + +int sd_netlink_message_append_data(sd_netlink_message *m, unsigned short type, const void *data, size_t len) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + + r = add_rtattr(m, type, data, len); + if (r < 0) + return r; + + return 0; +} + +int netlink_message_append_in_addr_union(sd_netlink_message *m, unsigned short type, int family, const union in_addr_union *data) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + assert_return(data, -EINVAL); + assert_return(IN_SET(family, AF_INET, AF_INET6), -EINVAL); + + r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR); + if (r < 0) + return r; + + r = add_rtattr(m, type, data, FAMILY_ADDRESS_SIZE(family)); + 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) { + return netlink_message_append_in_addr_union(m, type, AF_INET, (const union in_addr_union *) data); +} + +int sd_netlink_message_append_in6_addr(sd_netlink_message *m, unsigned short type, const struct in6_addr *data) { + return netlink_message_append_in_addr_union(m, type, AF_INET6, (const union in_addr_union *) data); +} + +int netlink_message_append_sockaddr_union(sd_netlink_message *m, unsigned short type, const union sockaddr_union *data) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + assert_return(data, -EINVAL); + assert_return(IN_SET(data->sa.sa_family, AF_INET, AF_INET6), -EINVAL); + + r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_SOCKADDR); + if (r < 0) + return r; + + r = add_rtattr(m, type, data, data->sa.sa_family == AF_INET ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6)); + if (r < 0) + return r; + + return 0; +} + +int sd_netlink_message_append_sockaddr_in(sd_netlink_message *m, unsigned short type, const struct sockaddr_in *data) { + return netlink_message_append_sockaddr_union(m, type, (const union sockaddr_union *) data); +} + +int sd_netlink_message_append_sockaddr_in6(sd_netlink_message *m, unsigned short type, const struct sockaddr_in6 *data) { + return netlink_message_append_sockaddr_union(m, type, (const union sockaddr_union *) data); +} + +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, NULL, type, NETLINK_TYPE_ETHER_ADDR); + if (r < 0) + return r; + + r = add_rtattr(m, type, data, ETH_ALEN); + if (r < 0) + return r; + + return 0; +} + +int netlink_message_append_hw_addr(sd_netlink_message *m, unsigned short type, const hw_addr_data *data) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + assert_return(data, -EINVAL); + assert_return(data->length > 0, -EINVAL); + + r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_ETHER_ADDR); + if (r < 0) + return r; + + r = add_rtattr(m, type, data->addr.bytes, data->length); + 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, NULL, type, NETLINK_TYPE_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); + /* m->containers[m->n_containers + 1] is accessed both in read and write. Prevent access out of bound */ + assert_return(m->n_containers < (RTNL_CONTAINER_DEPTH - 1), -ERANGE); + + r = message_attribute_has_type(m, &size, type, NETLINK_TYPE_NESTED); + if (r < 0) { + const NLTypeSystemUnion *type_system_union; + int family; + + r = message_attribute_has_type(m, &size, type, NETLINK_TYPE_UNION); + if (r < 0) + return r; + + r = sd_rtnl_message_get_family(m, &family); + if (r < 0) + return r; + + r = type_system_get_type_system_union(m->containers[m->n_containers].type_system, &type_system_union, type); + if (r < 0) + return r; + + r = type_system_union_protocol_get_type_system(type_system_union, + &m->containers[m->n_containers + 1].type_system, + family); + if (r < 0) + return r; + } else { + r = type_system_get_type_system(m->containers[m->n_containers].type_system, + &m->containers[m->n_containers + 1].type_system, + type); + if (r < 0) + return r; + } + + r = add_rtattr(m, type | NLA_F_NESTED, NULL, size); + if (r < 0) + return r; + + m->containers[m->n_containers++].offset = 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); + assert_return(m->n_containers < (RTNL_CONTAINER_DEPTH - 1), -ERANGE); + + r = type_system_get_type_system_union(m->containers[m->n_containers].type_system, &type_system_union, type); + if (r < 0) + return r; + + r = type_system_union_get_type_system(type_system_union, + &m->containers[m->n_containers + 1].type_system, + 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 ever need non-null size */ + r = add_rtattr(m, type | NLA_F_NESTED, NULL, 0); + if (r < 0) + return r; + + m->containers[m->n_containers++].offset = 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->containers[m->n_containers].type_system = NULL; + m->containers[m->n_containers].offset = 0; + m->n_containers--; + + return 0; +} + +int sd_netlink_message_open_array(sd_netlink_message *m, uint16_t type) { + int r; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + assert_return(m->n_containers < (RTNL_CONTAINER_DEPTH - 1), -ERANGE); + + r = add_rtattr(m, type | NLA_F_NESTED, NULL, 0); + if (r < 0) + return r; + + m->containers[m->n_containers].offset = r; + m->n_containers++; + m->containers[m->n_containers].type_system = m->containers[m->n_containers - 1].type_system; + + return 0; +} + +int sd_netlink_message_cancel_array(sd_netlink_message *m) { + unsigned i; + uint32_t rta_len; + + assert_return(m, -EINVAL); + assert_return(!m->sealed, -EPERM); + assert_return(m->n_containers > 1, -EINVAL); + + rta_len = GET_CONTAINER(m, (m->n_containers - 1))->rta_len; + + for (i = 0; i < m->n_containers; i++) + GET_CONTAINER(m, i)->rta_len -= rta_len; + + m->hdr->nlmsg_len -= rta_len; + + m->n_containers--; + m->containers[m->n_containers].type_system = NULL; + + return 0; +} + +static int netlink_message_read_internal(sd_netlink_message *m, unsigned short type, void **data, bool *net_byteorder) { + struct netlink_attribute *attribute; + struct rtattr *rta; + + assert_return(m, -EINVAL); + assert_return(m->sealed, -EPERM); + assert_return(data, -EINVAL); + + assert(m->n_containers < RTNL_CONTAINER_DEPTH); + + if (!m->containers[m->n_containers].attributes) + return -ENODATA; + + if (type >= m->containers[m->n_containers].n_attributes) + return -ENODATA; + + attribute = &m->containers[m->n_containers].attributes[type]; + + if (attribute->offset == 0) + return -ENODATA; + + rta = (struct rtattr*)((uint8_t *) m->hdr + attribute->offset); + + *data = RTA_DATA(rta); + + if (net_byteorder) + *net_byteorder = attribute->net_byteorder; + + return RTA_PAYLOAD(rta); +} + +int sd_netlink_message_read(sd_netlink_message *m, unsigned short type, size_t size, void *data) { + void *attr_data; + int r; + + assert_return(m, -EINVAL); + + r = netlink_message_read_internal(m, type, &attr_data, NULL); + if (r < 0) + return r; + + if ((size_t) r < size) + return -EIO; + + if (data) + memcpy(data, attr_data, size); + + return r; +} + +int sd_netlink_message_read_data(sd_netlink_message *m, unsigned short type, size_t *ret_size, void **ret_data) { + void *attr_data, *data; + int r; + + assert_return(m, -EINVAL); + + r = netlink_message_read_internal(m, type, &attr_data, NULL); + if (r < 0) + return r; + + if (ret_data) { + data = memdup(attr_data, r); + if (!data) + return -ENOMEM; + + *ret_data = data; + } + + if (ret_size) + *ret_size = r; + + return r; +} + +int sd_netlink_message_read_string_strdup(sd_netlink_message *m, unsigned short type, char **data) { + void *attr_data; + char *str; + int r; + + assert_return(m, -EINVAL); + + r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_STRING); + if (r < 0) + return r; + + r = netlink_message_read_internal(m, type, &attr_data, NULL); + if (r < 0) + return r; + + if (data) { + str = strndup(attr_data, r); + if (!str) + return -ENOMEM; + + *data = str; + } + + return 0; +} + +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, NULL, type, NETLINK_TYPE_STRING); + if (r < 0) + return r; + + r = netlink_message_read_internal(m, type, &attr_data, NULL); + 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, NULL, type, NETLINK_TYPE_U8); + if (r < 0) + return r; + + r = netlink_message_read_internal(m, type, &attr_data, NULL); + 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) { + void *attr_data; + bool net_byteorder; + int r; + + assert_return(m, -EINVAL); + + r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U16); + if (r < 0) + return r; + + r = netlink_message_read_internal(m, type, &attr_data, &net_byteorder); + if (r < 0) + return r; + else if ((size_t) r < sizeof(uint16_t)) + return -EIO; + + if (data) { + if (net_byteorder) + *data = be16toh(*(uint16_t *) attr_data); + else + *data = *(uint16_t *) attr_data; + } + + return 0; +} + +int sd_netlink_message_read_u32(sd_netlink_message *m, unsigned short type, uint32_t *data) { + void *attr_data; + bool net_byteorder; + int r; + + assert_return(m, -EINVAL); + + r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U32); + if (r < 0) + return r; + + r = netlink_message_read_internal(m, type, &attr_data, &net_byteorder); + if (r < 0) + return r; + else if ((size_t) r < sizeof(uint32_t)) + return -EIO; + + if (data) { + if (net_byteorder) + *data = be32toh(*(uint32_t *) attr_data); + else + *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, NULL, type, NETLINK_TYPE_ETHER_ADDR); + if (r < 0) + return r; + + r = netlink_message_read_internal(m, type, &attr_data, NULL); + 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 netlink_message_read_hw_addr(sd_netlink_message *m, unsigned short type, hw_addr_data *data) { + int r; + void *attr_data; + + assert_return(m, -EINVAL); + + r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_ETHER_ADDR); + if (r < 0) + return r; + + r = netlink_message_read_internal(m, type, &attr_data, NULL); + if (r < 0) + return r; + else if ((size_t) r > sizeof(union hw_addr_union)) + return -EIO; + + if (data) { + memcpy(data->addr.bytes, attr_data, r); + data->length = r; + } + + 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, NULL, type, NETLINK_TYPE_CACHE_INFO); + if (r < 0) + return r; + + r = netlink_message_read_internal(m, type, &attr_data, NULL); + 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 netlink_message_read_in_addr_union(sd_netlink_message *m, unsigned short type, int family, union in_addr_union *data) { + void *attr_data; + int r; + + assert_return(m, -EINVAL); + assert_return(IN_SET(family, AF_INET, AF_INET6), -EINVAL); + + r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR); + if (r < 0) + return r; + + r = netlink_message_read_internal(m, type, &attr_data, NULL); + if (r < 0) + return r; + else if ((size_t) r < FAMILY_ADDRESS_SIZE(family)) + return -EIO; + + if (data) + memcpy(data, attr_data, FAMILY_ADDRESS_SIZE(family)); + + return 0; +} + +int sd_netlink_message_read_in_addr(sd_netlink_message *m, unsigned short type, struct in_addr *data) { + union in_addr_union u; + int r; + + r = netlink_message_read_in_addr_union(m, type, AF_INET, &u); + if (r >= 0 && data) + *data = u.in; + + return r; +} + +int sd_netlink_message_read_in6_addr(sd_netlink_message *m, unsigned short type, struct in6_addr *data) { + union in_addr_union u; + int r; + + r = netlink_message_read_in_addr_union(m, type, AF_INET6, &u); + if (r >= 0 && data) + *data = u.in6; + + return r; +} + +int sd_netlink_message_read_strv(sd_netlink_message *m, unsigned short container_type, unsigned short type_id, char ***ret) { + _cleanup_strv_free_ char **s = NULL; + const NLTypeSystem *type_system; + const NLType *nl_type; + struct rtattr *rta; + void *container; + size_t rt_len; + int r; + + assert_return(m, -EINVAL); + assert_return(m->n_containers < RTNL_CONTAINER_DEPTH, -EINVAL); + + r = type_system_get_type(m->containers[m->n_containers].type_system, + &nl_type, + container_type); + if (r < 0) + return r; + + if (type_get_type(nl_type) != NETLINK_TYPE_NESTED) + return -EINVAL; + + r = type_system_get_type_system(m->containers[m->n_containers].type_system, + &type_system, + container_type); + if (r < 0) + return r; + + r = type_system_get_type(type_system, &nl_type, type_id); + if (r < 0) + return r; + + if (type_get_type(nl_type) != NETLINK_TYPE_STRING) + return -EINVAL; + + r = netlink_message_read_internal(m, container_type, &container, NULL); + if (r < 0) + return r; + + rt_len = (size_t) r; + rta = container; + + /* RTA_OK() macro compares with rta->rt_len, which is unsigned short, and + * LGTM.com analysis does not like the type difference. Hence, here we + * introduce an unsigned short variable as a workaround. */ + unsigned short len = rt_len; + for (; RTA_OK(rta, len); rta = RTA_NEXT(rta, len)) { + unsigned short type; + + type = RTA_TYPE(rta); + if (type != type_id) + continue; + + r = strv_extend(&s, RTA_DATA(rta)); + if (r < 0) + return r; + } + + *ret = TAKE_PTR(s); + return 0; +} + +static int netlink_container_parse(sd_netlink_message *m, + struct netlink_container *container, + struct rtattr *rta, + size_t rt_len) { + _cleanup_free_ struct netlink_attribute *attributes = NULL; + size_t n_allocated = 0; + + /* RTA_OK() macro compares with rta->rt_len, which is unsigned short, and + * LGTM.com analysis does not like the type difference. Hence, here we + * introduce an unsigned short variable as a workaround. */ + unsigned short len = rt_len; + for (; RTA_OK(rta, len); rta = RTA_NEXT(rta, len)) { + unsigned short type; + + type = RTA_TYPE(rta); + + if (!GREEDY_REALLOC0(attributes, n_allocated, type + 1)) + return -ENOMEM; + + if (attributes[type].offset != 0) + log_debug("rtnl: message parse - overwriting repeated attribute"); + + attributes[type].offset = (uint8_t *) rta - (uint8_t *) m->hdr; + attributes[type].nested = RTA_FLAGS(rta) & NLA_F_NESTED; + attributes[type].net_byteorder = RTA_FLAGS(rta) & NLA_F_NET_BYTEORDER; + } + + container->attributes = TAKE_PTR(attributes); + container->n_attributes = n_allocated; + + return 0; +} + +int sd_netlink_message_enter_container(sd_netlink_message *m, unsigned short type_id) { + const NLType *nl_type; + const NLTypeSystem *type_system; + void *container; + uint16_t type; + size_t size; + int r; + + assert_return(m, -EINVAL); + assert_return(m->n_containers < (RTNL_CONTAINER_DEPTH - 1), -EINVAL); + + r = type_system_get_type(m->containers[m->n_containers].type_system, + &nl_type, + type_id); + if (r < 0) + return r; + + type = type_get_type(nl_type); + + if (type == NETLINK_TYPE_NESTED) { + r = type_system_get_type_system(m->containers[m->n_containers].type_system, + &type_system, + type_id); + if (r < 0) + return r; + } else if (type == NETLINK_TYPE_UNION) { + const NLTypeSystemUnion *type_system_union; + + r = type_system_get_type_system_union(m->containers[m->n_containers].type_system, + &type_system_union, + type_id); + 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 = netlink_message_read_internal(m, type_id, &container, NULL); + if (r < 0) + return r; + + size = (size_t) r; + m->n_containers++; + + r = netlink_container_parse(m, + &m->containers[m->n_containers], + container, + size); + if (r < 0) { + m->n_containers--; + return r; + } + + m->containers[m->n_containers].type_system = type_system; + + return 0; +} + +int sd_netlink_message_enter_array(sd_netlink_message *m, unsigned short type_id) { + void *container; + size_t size; + int r; + + assert_return(m, -EINVAL); + assert_return(m->n_containers < (RTNL_CONTAINER_DEPTH - 1), -EINVAL); + + r = netlink_message_read_internal(m, type_id, &container, NULL); + if (r < 0) + return r; + + size = (size_t) r; + m->n_containers++; + + r = netlink_container_parse(m, + &m->containers[m->n_containers], + container, + size); + if (r < 0) { + m->n_containers--; + return r; + } + + m->containers[m->n_containers].type_system = m->containers[m->n_containers - 1].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); + + m->containers[m->n_containers].attributes = mfree(m->containers[m->n_containers].attributes); + m->containers[m->n_containers].type_system = 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(const 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(const 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; +} + +static int netlink_message_parse_error(sd_netlink_message *m) { + struct nlmsgerr *err = NLMSG_DATA(m->hdr); + size_t hlen = sizeof(struct nlmsgerr); + + /* no TLVs, nothing to do here */ + if (!(m->hdr->nlmsg_flags & NLM_F_ACK_TLVS)) + return 0; + + /* if NLM_F_CAPPED is set then the inner err msg was capped */ + if (!(m->hdr->nlmsg_flags & NLM_F_CAPPED)) + hlen += err->msg.nlmsg_len - sizeof(struct nlmsghdr); + + if (m->hdr->nlmsg_len <= NLMSG_SPACE(hlen)) + return 0; + + return netlink_container_parse(m, + &m->containers[m->n_containers], + (struct rtattr*)((uint8_t*) NLMSG_DATA(m->hdr) + hlen), + NLMSG_PAYLOAD(m->hdr, hlen)); +} + +int sd_netlink_message_rewind(sd_netlink_message *m, sd_netlink *genl) { + const NLType *nl_type; + uint16_t type; + size_t size; + unsigned i; + int r; + + assert_return(m, -EINVAL); + assert_return(genl || m->protocol != NETLINK_GENERIC, -EINVAL); + + /* don't allow appending to message once parsed */ + if (!m->sealed) + rtnl_message_seal(m); + + for (i = 1; i <= m->n_containers; i++) + m->containers[i].attributes = mfree(m->containers[i].attributes); + + m->n_containers = 0; + + if (m->containers[0].attributes) + /* top-level attributes have already been parsed */ + return 0; + + assert(m->hdr); + + r = type_system_root_get_type(genl, &nl_type, m->hdr->nlmsg_type); + if (r < 0) + return r; + + type = type_get_type(nl_type); + size = type_get_size(nl_type); + + if (type == NETLINK_TYPE_NESTED) { + const NLTypeSystem *type_system; + + type_get_type_system(nl_type, &type_system); + + m->containers[0].type_system = type_system; + + if (sd_netlink_message_is_error(m)) + r = netlink_message_parse_error(m); + else + r = netlink_container_parse(m, + &m->containers[m->n_containers], + (struct rtattr*)((uint8_t*) NLMSG_DATA(m->hdr) + NLMSG_ALIGN(size)), + NLMSG_PAYLOAD(m->hdr, 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; +} |