tx.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright 2007-2012 Siemens AG
  4 *
  5 * Written by:
  6 * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
  7 * Sergey Lapin <slapin@ossfans.org>
  8 * Maxim Gorbachyov <maxim.gorbachev@siemens.com>
  9 * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
 10 */
 11
 12#include <linux/netdevice.h>
 13#include <linux/if_arp.h>
 14#include <linux/crc-ccitt.h>
 15#include <linux/unaligned.h>
 16
 17#include <net/rtnetlink.h>
 18#include <net/ieee802154_netdev.h>
 19#include <net/mac802154.h>
 20#include <net/cfg802154.h>
 21
 22#include "ieee802154_i.h"
 23#include "driver-ops.h"
 24
 25void ieee802154_xmit_sync_worker(struct work_struct *work)
 26{
 27	struct ieee802154_local *local =
 28		container_of(work, struct ieee802154_local, sync_tx_work);
 29	struct sk_buff *skb = local->tx_skb;
 30	struct net_device *dev = skb->dev;
 31	int res;
 32
 33	res = drv_xmit_sync(local, skb);
 34	if (res)
 35		goto err_tx;
 36
 37	DEV_STATS_INC(dev, tx_packets);
 38	DEV_STATS_ADD(dev, tx_bytes, skb->len);
 39
 40	ieee802154_xmit_complete(&local->hw, skb, false);
 41
 42	return;
 43
 44err_tx:
 45	/* Restart the netif queue on each sub_if_data object. */
 46	ieee802154_release_queue(local);
 47	if (atomic_dec_and_test(&local->phy->ongoing_txs))
 48		wake_up(&local->phy->sync_txq);
 49	kfree_skb(skb);
 50	netdev_dbg(dev, "transmission failed\n");
 51}
 52
 53static netdev_tx_t
 54ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
 55{
 56	struct net_device *dev = skb->dev;
 57	int ret;
 58
 59	if (!(local->hw.flags & IEEE802154_HW_TX_OMIT_CKSUM)) {
 60		struct sk_buff *nskb;
 61		u16 crc;
 62
 63		if (unlikely(skb_tailroom(skb) < IEEE802154_FCS_LEN)) {
 64			nskb = skb_copy_expand(skb, 0, IEEE802154_FCS_LEN,
 65					       GFP_ATOMIC);
 66			if (likely(nskb)) {
 67				consume_skb(skb);
 68				skb = nskb;
 69			} else {
 70				goto err_free_skb;
 71			}
 72		}
 73
 74		crc = crc_ccitt(0, skb->data, skb->len);
 75		put_unaligned_le16(crc, skb_put(skb, 2));
 76	}
 77
 78	/* Stop the netif queue on each sub_if_data object. */
 79	ieee802154_hold_queue(local);
 80	atomic_inc(&local->phy->ongoing_txs);
 81
 82	/* Drivers should preferably implement the async callback. In some rare
 83	 * cases they only provide a sync callback which we will use as a
 84	 * fallback.
 85	 */
 86	if (local->ops->xmit_async) {
 87		unsigned int len = skb->len;
 88
 89		ret = drv_xmit_async(local, skb);
 90		if (ret)
 91			goto err_wake_netif_queue;
 92
 93		DEV_STATS_INC(dev, tx_packets);
 94		DEV_STATS_ADD(dev, tx_bytes, len);
 95	} else {
 96		local->tx_skb = skb;
 97		queue_work(local->workqueue, &local->sync_tx_work);
 98	}
 99
100	return NETDEV_TX_OK;
101
102err_wake_netif_queue:
103	ieee802154_release_queue(local);
104	if (atomic_dec_and_test(&local->phy->ongoing_txs))
105		wake_up(&local->phy->sync_txq);
106err_free_skb:
107	kfree_skb(skb);
108	return NETDEV_TX_OK;
109}
110
111static int ieee802154_sync_queue(struct ieee802154_local *local)
112{
113	int ret;
114
115	ieee802154_hold_queue(local);
116	ieee802154_disable_queue(local);
117	wait_event(local->phy->sync_txq, !atomic_read(&local->phy->ongoing_txs));
118	ret = local->tx_result;
119	ieee802154_release_queue(local);
120
121	return ret;
122}
123
124int ieee802154_sync_and_hold_queue(struct ieee802154_local *local)
125{
126	int ret;
127
128	ieee802154_hold_queue(local);
129	ret = ieee802154_sync_queue(local);
130	set_bit(WPAN_PHY_FLAG_STATE_QUEUE_STOPPED, &local->phy->flags);
131
132	return ret;
133}
134
135int ieee802154_mlme_op_pre(struct ieee802154_local *local)
136{
137	return ieee802154_sync_and_hold_queue(local);
138}
139
140int ieee802154_mlme_tx_locked(struct ieee802154_local *local,
141			      struct ieee802154_sub_if_data *sdata,
142			      struct sk_buff *skb)
143{
144	/* Avoid possible calls to ->ndo_stop() when we asynchronously perform
145	 * MLME transmissions.
146	 */
147	ASSERT_RTNL();
148
149	/* Ensure the device was not stopped, otherwise error out */
150	if (!local->open_count)
151		return -ENETDOWN;
152
153	/* Warn if the ieee802154 core thinks MLME frames can be sent while the
154	 * net interface expects this cannot happen.
155	 */
156	if (WARN_ON_ONCE(!netif_running(sdata->dev)))
157		return -ENETDOWN;
158
159	ieee802154_tx(local, skb);
160	return ieee802154_sync_queue(local);
161}
162
163int ieee802154_mlme_tx(struct ieee802154_local *local,
164		       struct ieee802154_sub_if_data *sdata,
165		       struct sk_buff *skb)
166{
167	int ret;
168
169	rtnl_lock();
170	ret = ieee802154_mlme_tx_locked(local, sdata, skb);
171	rtnl_unlock();
172
173	return ret;
174}
175
176void ieee802154_mlme_op_post(struct ieee802154_local *local)
177{
178	ieee802154_release_queue(local);
179}
180
181int ieee802154_mlme_tx_one_locked(struct ieee802154_local *local,
182				  struct ieee802154_sub_if_data *sdata,
183				  struct sk_buff *skb)
184{
185	int ret;
186
187	ieee802154_mlme_op_pre(local);
188	ret = ieee802154_mlme_tx_locked(local, sdata, skb);
189	ieee802154_mlme_op_post(local);
190
191	return ret;
192}
193
194static bool ieee802154_queue_is_stopped(struct ieee802154_local *local)
195{
196	return test_bit(WPAN_PHY_FLAG_STATE_QUEUE_STOPPED, &local->phy->flags);
197}
198
199static netdev_tx_t
200ieee802154_hot_tx(struct ieee802154_local *local, struct sk_buff *skb)
201{
202	/* Warn if the net interface tries to transmit frames while the
203	 * ieee802154 core assumes the queue is stopped.
204	 */
205	WARN_ON_ONCE(ieee802154_queue_is_stopped(local));
206
207	return ieee802154_tx(local, skb);
208}
209
210netdev_tx_t
211ieee802154_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev)
212{
213	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
214
215	skb->skb_iif = dev->ifindex;
216
217	return ieee802154_hot_tx(sdata->local, skb);
218}
219
220netdev_tx_t
221ieee802154_subif_start_xmit(struct sk_buff *skb, struct net_device *dev)
222{
223	struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
224	int rc;
225
226	/* TODO we should move it to wpan_dev_hard_header and dev_hard_header
227	 * functions. The reason is wireshark will show a mac header which is
228	 * with security fields but the payload is not encrypted.
229	 */
230	rc = mac802154_llsec_encrypt(&sdata->sec, skb);
231	if (rc) {
232		netdev_warn(dev, "encryption failed: %i\n", rc);
233		kfree_skb(skb);
234		return NETDEV_TX_OK;
235	}
236
237	skb->skb_iif = dev->ifindex;
238
239	return ieee802154_hot_tx(sdata->local, skb);
240}