#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)->containers[i].offset) : 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)

#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

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(&type_system_root, &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 = 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->containers[i].attributes);

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;

}

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

padding = mempcpy(RTA_DATA(rta), data, data_length);

else {

/* if no data was passed, make sure we still initialize the padding

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, 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_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_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, NULL, type, NETLINK_TYPE_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, NULL, type, NETLINK_TYPE_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, 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 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);

assert_return(m->n_containers < RTNL_CONTAINER_DEPTH, -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);

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 evere 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->n_containers --;

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);

assert(m->containers[m->n_containers].attributes);

assert(type < m->containers[m->n_containers].n_attributes);

attribute = &m->containers[m->n_containers].attributes[type];

if(!attribute->offset)

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_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 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 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, 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 < 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, 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 < sizeof(struct in6_addr))

return -EIO;

if (data)

memcpy(data, attr_data, sizeof(struct in6_addr));

return 0;

}

static int netlink_container_parse(sd_netlink_message *m,

struct netlink_container *container,

int count,

struct rtattr *rta,

unsigned int rt_len) {

_cleanup_free_ struct netlink_attribute *attributes = NULL;

attributes = new0(struct netlink_attribute, count);

if(!attributes)

return -ENOMEM;

for (; RTA_OK(rta, rt_len); rta = RTA_NEXT(rta, rt_len)) {

unsigned short type;

type = RTA_TYPE(rta);

/* if the kernel is newer than the headers we used

if (type >= count)

continue;

if (attributes[type].offset)

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 = attributes;

attributes = NULL;

container->n_attributes = count;

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, -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;

else

size = (size_t)r;

m->n_containers ++;

r = netlink_container_parse(m,

&m->containers[m->n_containers],

type_system_get_count(type_system),

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_exit_container(sd_netlink_message *m) {

assert_return(m, -EINVAL);

assert_return(m->sealed, -EINVAL);

assert_return(m->n_containers > 0, -EINVAL);

free(m->containers[m->n_containers].attributes);

m->containers[m->n_containers].attributes = NULL;

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(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 sd_netlink_message_rewind(sd_netlink_message *m) {

const NLType *nl_type;

uint16_t type;

size_t size;

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->containers[i].attributes);

m->containers[i].attributes = NULL;

}

m->n_containers = 0;

if (m->containers[0].attributes) {

/* top-level attributes have already been parsed */

return 0;

}

assert(m->hdr);

r = type_system_get_type(&type_system_root, &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;

r = netlink_container_parse(m,

&m->containers[m->n_containers],

type_system_get_count(type_system),

(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;

}