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linux/net/mac802154/rx.c
Miquel Raynal f0da47118c net: mac802154: Fix a condition in the receive path 
Upon reception, a packet must be categorized, either it's destination is
the host, or it is another host. A packet with no destination addressing
fields may be valid in two situations:
- the packet has no source field: only ACKs are built like that, we
  consider the host as the destination.
- the packet has a valid source field: it is directed to the PAN
  coordinator, as for know we don't have this information we consider we
  are not the PAN coordinator.

There was likely a copy/paste error made during a previous cleanup
because the if clause is now containing exactly the same condition as in
the switch case, which can never be true. In the past the destination
address was used in the switch and the source address was used in the
if, which matches what the spec says.

Cc: stable@vger.kernel.org
Fixes: ae531b9475 ("ieee802154: use ieee802154_addr instead of *_sa variants")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20220826142954.254853-1-miquel.raynal@bootlin.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
2022-08-29 11:10:22 +02:00

304 lines
7.1 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2007-2012 Siemens AG
*
* Written by:
* Pavel Smolenskiy <pavel.smolenskiy@gmail.com>
* Maxim Gorbachyov <maxim.gorbachev@siemens.com>
* Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
* Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/crc-ccitt.h>
#include <asm/unaligned.h>
#include <net/mac802154.h>
#include <net/ieee802154_netdev.h>
#include <net/nl802154.h>
#include "ieee802154_i.h"
static int ieee802154_deliver_skb(struct sk_buff *skb)
{
skb->ip_summed = CHECKSUM_UNNECESSARY;
skb->protocol = htons(ETH_P_IEEE802154);
return netif_receive_skb(skb);
}
static int
ieee802154_subif_frame(struct ieee802154_sub_if_data *sdata,
struct sk_buff *skb, const struct ieee802154_hdr *hdr)
{
struct wpan_dev *wpan_dev = &sdata->wpan_dev;
__le16 span, sshort;
int rc;
pr_debug("getting packet via slave interface %s\n", sdata->dev->name);
span = wpan_dev->pan_id;
sshort = wpan_dev->short_addr;
switch (mac_cb(skb)->dest.mode) {
case IEEE802154_ADDR_NONE:
if (hdr->source.mode != IEEE802154_ADDR_NONE)
/* FIXME: check if we are PAN coordinator */
skb->pkt_type = PACKET_OTHERHOST;
else
/* ACK comes with both addresses empty */
skb->pkt_type = PACKET_HOST;
break;
case IEEE802154_ADDR_LONG:
if (mac_cb(skb)->dest.pan_id != span &&
mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
skb->pkt_type = PACKET_OTHERHOST;
else if (mac_cb(skb)->dest.extended_addr == wpan_dev->extended_addr)
skb->pkt_type = PACKET_HOST;
else
skb->pkt_type = PACKET_OTHERHOST;
break;
case IEEE802154_ADDR_SHORT:
if (mac_cb(skb)->dest.pan_id != span &&
mac_cb(skb)->dest.pan_id != cpu_to_le16(IEEE802154_PANID_BROADCAST))
skb->pkt_type = PACKET_OTHERHOST;
else if (mac_cb(skb)->dest.short_addr == sshort)
skb->pkt_type = PACKET_HOST;
else if (mac_cb(skb)->dest.short_addr ==
cpu_to_le16(IEEE802154_ADDR_BROADCAST))
skb->pkt_type = PACKET_BROADCAST;
else
skb->pkt_type = PACKET_OTHERHOST;
break;
default:
pr_debug("invalid dest mode\n");
goto fail;
}
skb->dev = sdata->dev;
/* TODO this should be moved after netif_receive_skb call, otherwise
* wireshark will show a mac header with security fields and the
* payload is already decrypted.
*/
rc = mac802154_llsec_decrypt(&sdata->sec, skb);
if (rc) {
pr_debug("decryption failed: %i\n", rc);
goto fail;
}
sdata->dev->stats.rx_packets++;
sdata->dev->stats.rx_bytes += skb->len;
switch (mac_cb(skb)->type) {
case IEEE802154_FC_TYPE_BEACON:
case IEEE802154_FC_TYPE_ACK:
case IEEE802154_FC_TYPE_MAC_CMD:
goto fail;
case IEEE802154_FC_TYPE_DATA:
return ieee802154_deliver_skb(skb);
default:
pr_warn_ratelimited("ieee802154: bad frame received "
"(type = %d)\n", mac_cb(skb)->type);
goto fail;
}
fail:
kfree_skb(skb);
return NET_RX_DROP;
}
static void
ieee802154_print_addr(const char *name, const struct ieee802154_addr *addr)
{
if (addr->mode == IEEE802154_ADDR_NONE)
pr_debug("%s not present\n", name);
pr_debug("%s PAN ID: %04x\n", name, le16_to_cpu(addr->pan_id));
if (addr->mode == IEEE802154_ADDR_SHORT) {
pr_debug("%s is short: %04x\n", name,
le16_to_cpu(addr->short_addr));
} else {
u64 hw = swab64((__force u64)addr->extended_addr);
pr_debug("%s is hardware: %8phC\n", name, &hw);
}
}
static int
ieee802154_parse_frame_start(struct sk_buff *skb, struct ieee802154_hdr *hdr)
{
int hlen;
struct ieee802154_mac_cb *cb = mac_cb_init(skb);
skb_reset_mac_header(skb);
hlen = ieee802154_hdr_pull(skb, hdr);
if (hlen < 0)
return -EINVAL;
skb->mac_len = hlen;
pr_debug("fc: %04x dsn: %02x\n", le16_to_cpup((__le16 *)&hdr->fc),
hdr->seq);
cb->type = hdr->fc.type;
cb->ackreq = hdr->fc.ack_request;
cb->secen = hdr->fc.security_enabled;
ieee802154_print_addr("destination", &hdr->dest);
ieee802154_print_addr("source", &hdr->source);
cb->source = hdr->source;
cb->dest = hdr->dest;
if (hdr->fc.security_enabled) {
u64 key;
pr_debug("seclevel %i\n", hdr->sec.level);
switch (hdr->sec.key_id_mode) {
case IEEE802154_SCF_KEY_IMPLICIT:
pr_debug("implicit key\n");
break;
case IEEE802154_SCF_KEY_INDEX:
pr_debug("key %02x\n", hdr->sec.key_id);
break;
case IEEE802154_SCF_KEY_SHORT_INDEX:
pr_debug("key %04x:%04x %02x\n",
le32_to_cpu(hdr->sec.short_src) >> 16,
le32_to_cpu(hdr->sec.short_src) & 0xffff,
hdr->sec.key_id);
break;
case IEEE802154_SCF_KEY_HW_INDEX:
key = swab64((__force u64)hdr->sec.extended_src);
pr_debug("key source %8phC %02x\n", &key,
hdr->sec.key_id);
break;
}
}
return 0;
}
static void
__ieee802154_rx_handle_packet(struct ieee802154_local *local,
struct sk_buff *skb)
{
int ret;
struct ieee802154_sub_if_data *sdata;
struct ieee802154_hdr hdr;
ret = ieee802154_parse_frame_start(skb, &hdr);
if (ret) {
pr_debug("got invalid frame\n");
kfree_skb(skb);
return;
}
list_for_each_entry_rcu(sdata, &local->interfaces, list) {
if (sdata->wpan_dev.iftype != NL802154_IFTYPE_NODE)
continue;
if (!ieee802154_sdata_running(sdata))
continue;
ieee802154_subif_frame(sdata, skb, &hdr);
skb = NULL;
break;
}
kfree_skb(skb);
}
static void
ieee802154_monitors_rx(struct ieee802154_local *local, struct sk_buff *skb)
{
struct sk_buff *skb2;
struct ieee802154_sub_if_data *sdata;
skb_reset_mac_header(skb);
skb->ip_summed = CHECKSUM_UNNECESSARY;
skb->pkt_type = PACKET_OTHERHOST;
skb->protocol = htons(ETH_P_IEEE802154);
list_for_each_entry_rcu(sdata, &local->interfaces, list) {
if (sdata->wpan_dev.iftype != NL802154_IFTYPE_MONITOR)
continue;
if (!ieee802154_sdata_running(sdata))
continue;
skb2 = skb_clone(skb, GFP_ATOMIC);
if (skb2) {
skb2->dev = sdata->dev;
ieee802154_deliver_skb(skb2);
sdata->dev->stats.rx_packets++;
sdata->dev->stats.rx_bytes += skb->len;
}
}
}
void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *skb)
{
u16 crc;
WARN_ON_ONCE(softirq_count() == 0);
if (local->suspended)
goto drop;
/* TODO: When a transceiver omits the checksum here, we
* add an own calculated one. This is currently an ugly
* solution because the monitor needs a crc here.
*/
if (local->hw.flags & IEEE802154_HW_RX_OMIT_CKSUM) {
crc = crc_ccitt(0, skb->data, skb->len);
put_unaligned_le16(crc, skb_put(skb, 2));
}
rcu_read_lock();
ieee802154_monitors_rx(local, skb);
/* Check if transceiver doesn't validate the checksum.
* If not we validate the checksum here.
*/
if (local->hw.flags & IEEE802154_HW_RX_DROP_BAD_CKSUM) {
crc = crc_ccitt(0, skb->data, skb->len);
if (crc) {
rcu_read_unlock();
goto drop;
}
}
/* remove crc */
skb_trim(skb, skb->len - 2);
__ieee802154_rx_handle_packet(local, skb);
rcu_read_unlock();
return;
drop:
kfree_skb(skb);
}
void
ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi)
{
struct ieee802154_local *local = hw_to_local(hw);
mac_cb(skb)->lqi = lqi;
skb->pkt_type = IEEE802154_RX_MSG;
skb_queue_tail(&local->skb_queue, skb);
tasklet_schedule(&local->tasklet);
}
EXPORT_SYMBOL(ieee802154_rx_irqsafe);
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