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net: l2: ieee802154: fix double address swap

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As we have to provide LL addresses in big endian to userspace to be
POSIX compliant and we also do not want to reserve extra space for
such addresses, bff6a5cce5 introduced
a change that swaps address bytes in place in the packet before
returning the packet with LL address pointers to userspace.

Unfortunately a regression sneaked into the code base while doing
so: The byte swapping was duplicated when using 6LoWPAN compression
and the byte swapping caused decryption to fail in some cases,
see #53630. This commit fixes the problem.

Fixes: #53630

Signed-off-by: Florian Grandel <jerico.dev@gmail.com>
This commit is contained in:
Florian Grandel 2023-01-08 12:13:23 +01:00 • committed by Carles Cufí
commit e854314928
2 changed files with 18 additions and 26 deletions
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31
subsys/net/l2/ieee802154/ieee802154.c
View file

@ -94,9 +94,9 @@ static inline void ieee802154_acknowledge(struct net_if *iface, struct ieee80215
#define ieee802154_acknowledge(...)
#endif /* CONFIG_NET_L2_IEEE802154_ACK_REPLY */
static inline void set_pkt_ll_addr(struct net_linkaddr *addr, bool comp,
enum ieee802154_addressing_mode mode,
struct ieee802154_address_field *ll)
static inline void swap_and_set_pkt_ll_addr(struct net_linkaddr *addr, bool comp,
enum ieee802154_addressing_mode mode,
struct ieee802154_address_field *ll)
{
addr->type = NET_LINK_IEEE802154;
@ -127,8 +127,9 @@ static inline void set_pkt_ll_addr(struct net_linkaddr *addr, bool comp,
addr->addr = NULL;
}
/* Swap address byte order in place from little to big endian.
* This is ok as the ll address field comes from the header
/* The net stack expects link layer addresses to be in
* big endian format for posix compliance so we must swap it.
* This is ok as the L2 address field comes from the header
* part of the packet buffer which will not be directly accessible
* once the packet reaches the upper layers.
*/
@ -238,18 +239,22 @@ static enum net_verdict ieee802154_recv(struct net_if *iface, struct net_pkt *pk
ieee802154_acknowledge(iface, &mpdu);
net_pkt_set_ll_proto_type(pkt, ETH_P_IEEE802154);
set_pkt_ll_addr(net_pkt_lladdr_src(pkt), mpdu.mhr.fs->fc.pan_id_comp,
mpdu.mhr.fs->fc.src_addr_mode, mpdu.mhr.src_addr);
set_pkt_ll_addr(net_pkt_lladdr_dst(pkt), false, mpdu.mhr.fs->fc.dst_addr_mode,
mpdu.mhr.dst_addr);
if (!ieee802154_decipher_data_frame(iface, pkt, &mpdu)) {
return NET_DROP;
}
/* Setting L2 addresses must be done after packet authentication and internal
* packet handling as it will mangle the package header to comply with upper
* network layers' (POSIX) requirement to represent network addresses in big endian.
*/
swap_and_set_pkt_ll_addr(net_pkt_lladdr_src(pkt), mpdu.mhr.fs->fc.pan_id_comp,
mpdu.mhr.fs->fc.src_addr_mode, mpdu.mhr.src_addr);
swap_and_set_pkt_ll_addr(net_pkt_lladdr_dst(pkt), false, mpdu.mhr.fs->fc.dst_addr_mode,
mpdu.mhr.dst_addr);
net_pkt_set_ll_proto_type(pkt, ETH_P_IEEE802154);
pkt_hexdump(RX_PKT_TITLE " (with ll)", pkt, true);
hdr_len = (uint8_t *)mpdu.payload - net_pkt_data(pkt);

13
subsys/net/l2/ieee802154/ieee802154_6lo.c
View file

@ -24,19 +24,6 @@ LOG_MODULE_REGISTER(net_ieee802154_6lo, CONFIG_NET_L2_IEEE802154_LOG_LEVEL);
enum net_verdict ieee802154_6lo_decode_pkt(struct net_if *iface, struct net_pkt *pkt)
{
/* Upper IP stack expects the link layer address to be in
* big endian format so we must swap it here.
*/
if (net_pkt_lladdr_src(pkt)->addr &&
net_pkt_lladdr_src(pkt)->len == IEEE802154_EXT_ADDR_LENGTH) {
sys_mem_swap(net_pkt_lladdr_src(pkt)->addr, net_pkt_lladdr_src(pkt)->len);
}
if (net_pkt_lladdr_dst(pkt)->addr &&
net_pkt_lladdr_dst(pkt)->len == IEEE802154_EXT_ADDR_LENGTH) {
sys_mem_swap(net_pkt_lladdr_dst(pkt)->addr, net_pkt_lladdr_dst(pkt)->len);
}
#ifdef CONFIG_NET_L2_IEEE802154_FRAGMENT
return ieee802154_6lo_reassemble(pkt);
#else