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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <netinet/icmp6.h>
#include "sd-ndisc.h"
#include "alloc-util.h"
#include "in-addr-util.h"
#include "ndisc-internal.h"
#include "ndisc-neighbor-internal.h"
#include "ndisc-option.h"
static sd_ndisc_neighbor* ndisc_neighbor_free(sd_ndisc_neighbor *na) {
if (!na)
return NULL;
icmp6_packet_unref(na->packet);
set_free(na->options);
return mfree(na);
}
DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_ndisc_neighbor, sd_ndisc_neighbor, ndisc_neighbor_free);
sd_ndisc_neighbor* ndisc_neighbor_new(ICMP6Packet *packet) {
sd_ndisc_neighbor *na;
assert(packet);
na = new(sd_ndisc_neighbor, 1);
if (!na)
return NULL;
*na = (sd_ndisc_neighbor) {
.n_ref = 1,
.packet = icmp6_packet_ref(packet),
};
return na;
}
int ndisc_neighbor_parse(sd_ndisc *nd, sd_ndisc_neighbor *na) {
int r;
assert(na);
if (na->packet->raw_size < sizeof(struct nd_neighbor_advert))
return log_ndisc_errno(nd, SYNTHETIC_ERRNO(EBADMSG),
"Too small to be a neighbor advertisement, ignoring datagram.");
/* Neighbor advertisement packets are neatly aligned to 64-bit boundaries, hence we can access them directly */
const struct nd_neighbor_advert *a = (const struct nd_neighbor_advert*) na->packet->raw_packet;
assert(a->nd_na_type == ND_NEIGHBOR_ADVERT);
assert(a->nd_na_code == 0);
na->flags = a->nd_na_flags_reserved; /* the first 3 bits */
na->target_address = a->nd_na_target;
/* RFC 4861 section 4.4:
* For solicited advertisements, the Target Address field in the Neighbor Solicitation message that
* prompted this advertisement. For an unsolicited advertisement, the address whose link-layer
* address has changed. The Target Address MUST NOT be a multicast address.
*
* Here, we only check if the target address is a link-layer address (or a null address, for safety)
* when the message is an unsolicited neighbor advertisement. */
if (!FLAGS_SET(na->flags, ND_NA_FLAG_SOLICITED))
if (!in6_addr_is_link_local(&na->target_address) && !in6_addr_is_null(&na->target_address))
return log_ndisc_errno(nd, SYNTHETIC_ERRNO(EBADMSG),
"Received ND packet with an invalid target address (%s), ignoring datagram.",
IN6_ADDR_TO_STRING(&na->target_address));
r = ndisc_parse_options(na->packet, &na->options);
if (r < 0)
return log_ndisc_errno(nd, r, "Failed to parse NDisc options in neighbor advertisement message, ignoring: %m");
return 0;
}
int sd_ndisc_neighbor_get_sender_address(sd_ndisc_neighbor *na, struct in6_addr *ret) {
assert_return(na, -EINVAL);
return icmp6_packet_get_sender_address(na->packet, ret);
}
int sd_ndisc_neighbor_get_target_address(sd_ndisc_neighbor *na, struct in6_addr *ret) {
assert_return(na, -EINVAL);
if (in6_addr_is_null(&na->target_address))
/* fall back to the sender address, for safety. */
return sd_ndisc_neighbor_get_sender_address(na, ret);
if (ret)
*ret = na->target_address;
return 0;
}
int sd_ndisc_neighbor_get_target_mac(sd_ndisc_neighbor *na, struct ether_addr *ret) {
assert_return(na, -EINVAL);
return ndisc_option_get_mac(na->options, SD_NDISC_OPTION_TARGET_LL_ADDRESS, ret);
}
int sd_ndisc_neighbor_get_flags(sd_ndisc_neighbor *na, uint32_t *ret) {
assert_return(na, -EINVAL);
if (ret)
*ret = na->flags;
return 0;
}
int sd_ndisc_neighbor_is_router(sd_ndisc_neighbor *na) {
assert_return(na, -EINVAL);
return FLAGS_SET(na->flags, ND_NA_FLAG_ROUTER);
}
int sd_ndisc_neighbor_is_solicited(sd_ndisc_neighbor *na) {
assert_return(na, -EINVAL);
return FLAGS_SET(na->flags, ND_NA_FLAG_SOLICITED);
}
int sd_ndisc_neighbor_is_override(sd_ndisc_neighbor *na) {
assert_return(na, -EINVAL);
return FLAGS_SET(na->flags, ND_NA_FLAG_OVERRIDE);
}
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