Luca Boccassi
8baed40298
NDisc packets received through the socket path are filtered before parser dispatch, but parser entry points should still reject malformed packet bytes instead of asserting on them. Return EBADMSG for non-zero ICMPv6 code values in RA, NA, and Redirect messages. Follow-up forc34cb1d645Follow-up for696eb2b8deFollow-up for44e8cf303b
131 lines
4.5 KiB
C
131 lines
4.5 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
|
|
|
|
#include <netinet/icmp6.h>
|
|
|
|
#include "sd-ndisc.h"
|
|
|
|
#include "alloc-util.h"
|
|
#include "icmp6-packet.h"
|
|
#include "in-addr-util.h"
|
|
#include "ndisc-internal.h"
|
|
#include "ndisc-neighbor-internal.h"
|
|
#include "ndisc-option.h"
|
|
#include "set.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);
|
|
if (a->nd_na_code != 0)
|
|
return log_ndisc_errno(nd, SYNTHETIC_ERRNO(EBADMSG),
|
|
"Received Neighbor Advertisement with non-zero code, ignoring datagram.");
|
|
|
|
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);
|
|
}
|