From: Johannes Berg <johannes.berg@xxxxxxxxx>
Factor out the 802.11 header building code from the xmit function
to be able to use it separately in a later commit.
While at it, fix up some documentation.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Arik Nemtsov <arik@xxxxxxxxxx>
---
net/mac80211/tx.c | 142 ++++++++++++++++++++++++++++++++++--------------------
1 file changed, 91 insertions(+), 51 deletions(-)
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index c4a5494..f67131a 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -1784,24 +1784,26 @@ static void ieee80211_tx_latency_start_msrmnt(struct ieee80211_local *local,
}
/**
- * __ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
- * subinterfaces (wlan#, WDS, and VLAN interfaces)
- * @skb: packet to be sent
- * @dev: incoming interface
+ * ieee80211_build_hdr - build 802.11 header in the given frame
+ * @sdata: virtual interface to build the header for
+ * @skb: the skb to build the header in
* @info_flags: skb flags to set
*
- * On failure skb will be freed.
+ * This function takes the skb with 802.3 header and reformats the header to
+ * the appropriate IEEE 802.11 header based on which interface the packet is
+ * being transmitted on.
+ *
+ * Note that this function also takes care of the TX status request and
+ * potential unsharing of the SKB - this needs to be interleaved with the
+ * header building.
+ *
+ * The function requires the read-side RCU lock held
*
- * This function takes in an Ethernet header and encapsulates it with suitable
- * IEEE 802.11 header based on which interface the packet is coming in. The
- * encapsulated packet will then be passed to master interface, wlan#.11, for
- * transmission (through low-level driver).
+ * Returns: the (possibly reallocated) skb or an ERR_PTR() code
*/
-void __ieee80211_subif_start_xmit(struct sk_buff *skb,
- struct net_device *dev,
- u32 info_flags)
+static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
+ struct sk_buff *skb, u32 info_flags)
{
- struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
struct ieee80211_local *local = sdata->local;
struct ieee80211_tx_info *info;
int head_need;
@@ -1821,20 +1823,13 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
struct ieee80211_chanctx_conf *chanctx_conf;
struct ieee80211_sub_if_data *ap_sdata;
enum ieee80211_band band;
-
- if (unlikely(skb->len < ETH_HLEN))
- goto fail;
+ int ret;
/* convert Ethernet header to proper 802.11 header (based on
* operation mode) */
ethertype = (skb->data[12] << 8) | skb->data[13];
fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
- rcu_read_lock();
-
- /* Measure frame arrival for Tx latency statistics calculation */
- ieee80211_tx_latency_start_msrmnt(local, skb);
-
switch (sdata->vif.type) {
case NL80211_IFTYPE_AP_VLAN:
sta = rcu_dereference(sdata->u.vlan.sta);
@@ -1852,8 +1847,10 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
ap_sdata = container_of(sdata->bss, struct ieee80211_sub_if_data,
u.ap);
chanctx_conf = rcu_dereference(ap_sdata->vif.chanctx_conf);
- if (!chanctx_conf)
- goto fail_rcu;
+ if (!chanctx_conf) {
+ ret = -ENOTCONN;
+ goto free;
+ }
band = chanctx_conf->def.chan->band;
if (sta)
break;
@@ -1861,8 +1858,10 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
case NL80211_IFTYPE_AP:
if (sdata->vif.type == NL80211_IFTYPE_AP)
chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
- if (!chanctx_conf)
- goto fail_rcu;
+ if (!chanctx_conf) {
+ ret = -ENOTCONN;
+ goto free;
+ }
fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
/* DA BSSID SA */
memcpy(hdr.addr1, skb->data, ETH_ALEN);
@@ -1949,8 +1948,10 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
}
chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
- if (!chanctx_conf)
- goto fail_rcu;
+ if (!chanctx_conf) {
+ ret = -ENOTCONN;
+ goto free;
+ }
band = chanctx_conf->def.chan->band;
break;
#endif
@@ -1980,8 +1981,10 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
* of a link teardown after a TDLS sta is removed due to being
* unreachable.
*/
- if (tdls_peer && !tdls_auth && !tdls_setup_frame)
- goto fail_rcu;
+ if (tdls_peer && !tdls_auth && !tdls_setup_frame) {
+ ret = -EINVAL;
+ goto free;
+ }
/* send direct packets to authorized TDLS peers */
if (tdls_peer && tdls_auth) {
@@ -2009,8 +2012,10 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
hdrlen = 24;
}
chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
- if (!chanctx_conf)
- goto fail_rcu;
+ if (!chanctx_conf) {
+ ret = -ENOTCONN;
+ goto free;
+ }
band = chanctx_conf->def.chan->band;
break;
case NL80211_IFTYPE_OCB:
@@ -2020,8 +2025,10 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
eth_broadcast_addr(hdr.addr3);
hdrlen = 24;
chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
- if (!chanctx_conf)
- goto fail_rcu;
+ if (!chanctx_conf) {
+ ret = -ENOTCONN;
+ goto free;
+ }
band = chanctx_conf->def.chan->band;
break;
case NL80211_IFTYPE_ADHOC:
@@ -2031,12 +2038,15 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
hdrlen = 24;
chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
- if (!chanctx_conf)
- goto fail_rcu;
+ if (!chanctx_conf) {
+ ret = -ENOTCONN;
+ goto free;
+ }
band = chanctx_conf->def.chan->band;
break;
default:
- goto fail_rcu;
+ ret = -EINVAL;
+ goto free;
}
/*
@@ -2079,7 +2089,8 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
- goto fail_rcu;
+ ret = -EPERM;
+ goto free;
}
if (unlikely(!multicast && skb->sk &&
@@ -2116,8 +2127,10 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
skb = skb_clone(skb, GFP_ATOMIC);
kfree_skb(tmp_skb);
- if (!skb)
- goto fail_rcu;
+ if (!skb) {
+ ret = -ENOMEM;
+ goto free;
+ }
}
hdr.frame_control = fc;
@@ -2166,7 +2179,7 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
if (ieee80211_skb_resize(sdata, skb, head_need, true)) {
ieee80211_free_txskb(&local->hw, skb);
skb = NULL;
- goto fail_rcu;
+ return ERR_PTR(-ENOMEM);
}
}
@@ -2200,9 +2213,6 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
nh_pos += hdrlen;
h_pos += hdrlen;
- dev->stats.tx_packets++;
- dev->stats.tx_bytes += skb->len;
-
/* Update skb pointers to various headers since this modified frame
* is going to go through Linux networking code that may potentially
* need things like pointer to IP header. */
@@ -2213,23 +2223,53 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
info = IEEE80211_SKB_CB(skb);
memset(info, 0, sizeof(*info));
- dev->trans_start = jiffies;
-
info->flags = info_flags;
info->ack_frame_id = info_id;
info->band = band;
- ieee80211_xmit(sdata, skb);
- rcu_read_unlock();
+ return skb;
+ free:
+ kfree_skb(skb);
+ return ERR_PTR(ret);
+}
+
+void __ieee80211_subif_start_xmit(struct sk_buff *skb,
+ struct net_device *dev,
+ u32 info_flags)
+{
+ struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+ struct ieee80211_local *local = sdata->local;
+
+ if (unlikely(skb->len < ETH_HLEN)) {
+ kfree_skb(skb);
+ return;
+ }
+
+ rcu_read_lock();
+
+ /* Measure frame arrival for Tx latency statistics calculation */
+ ieee80211_tx_latency_start_msrmnt(local, skb);
+
+ skb = ieee80211_build_hdr(sdata, skb, info_flags);
+ if (IS_ERR(skb))
+ goto out;
- return;
+ dev->stats.tx_packets++;
+ dev->stats.tx_bytes += skb->len;
+ dev->trans_start = jiffies;
- fail_rcu:
+ ieee80211_xmit(sdata, skb);
+ out:
rcu_read_unlock();
- fail:
- dev_kfree_skb(skb);
}
+/**
+ * ieee80211_subif_start_xmit - netif start_xmit function for 802.3 vifs
+ * @skb: packet to be sent
+ * @dev: incoming interface
+ *
+ * On failure skb will be freed.
+ */
netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
--
1.9.1
--
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