[PATCH] ieee80211: adds support for the creation of RTS packets

tree b45c9c1017fd23216bfbe71e441aed9aa297fc84
parent 04aacdd71e904656a304d923bdcf57ad3bd2b254
author Ivo van Doorn <IvDoorn@gmail.com> 1124445405 -0500
committer James Ketrenos <jketreno@linux.intel.com> 1127313029 -0500

This patch adds support for the creation of RTS packets when the
config flag CFG_IEEE80211_RTS has been set.

Signed-Off-By: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: James Ketrenos <jketreno@linux.intel.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

3 files changed, 41 insertions, 3 deletions

diff --git a/include/net/ieee80211.h b/include/net/ieee80211.h
index ebe7e41e5eaf..5e11ccf8a763 100644
--- a/include/net/ieee80211.h
+++ b/include/net/ieee80211.h
@@ -690,6 +690,7 @@ enum ieee80211_state {
 
 #define CFG_IEEE80211_RESERVE_FCS (1<<0)
 #define CFG_IEEE80211_COMPUTE_FCS (1<<1)
+#define CFG_IEEE80211_RTS (1<<2)
 
 struct ieee80211_device {
         struct net_device *dev;
@@ -747,6 +748,7 @@ struct ieee80211_device {
         struct ieee80211_frag_entry frag_cache[IEEE80211_FRAG_CACHE_LEN];
         unsigned int frag_next_idx;
         u16 fts;                /* Fragmentation Threshold */
+        u16 rts;                /* RTS threshold */
 
         /* Association info */
         u8 bssid[ETH_ALEN];
diff --git a/net/ieee80211/ieee80211_module.c b/net/ieee80211/ieee80211_module.c
index 82a4fd713b28..67d6bdd2e3f2 100644
--- a/net/ieee80211/ieee80211_module.c
+++ b/net/ieee80211/ieee80211_module.c
@@ -126,6 +126,7 @@ struct net_device *alloc_ieee80211(int sizeof_priv)
 
         /* Default fragmentation threshold is maximum payload size */
         ieee->fts = DEFAULT_FTS;
+        ieee->rts = DEFAULT_FTS;
         ieee->scan_age = DEFAULT_MAX_SCAN_AGE;
         ieee->open_wep = 1;
 
diff --git a/net/ieee80211/ieee80211_tx.c b/net/ieee80211/ieee80211_tx.c
index 29770cfefc3d..cdee41cefb26 100644
--- a/net/ieee80211/ieee80211_tx.c
+++ b/net/ieee80211/ieee80211_tx.c
@@ -222,13 +222,15 @@ static struct ieee80211_txb *ieee80211_alloc_txb(int nr_frags, int txb_size,
         return txb;
 }
 
-/* SKBs are added to the ieee->tx_queue. */
+/* Incoming skb is converted to a txb which consist of
+ * a block of 802.11 fragment packets (stored as skbs) */
 int ieee80211_xmit(struct sk_buff *skb, struct net_device *dev)
 {
         struct ieee80211_device *ieee = netdev_priv(dev);
         struct ieee80211_txb *txb = NULL;
         struct ieee80211_hdr_3addr *frag_hdr;
-        int i, bytes_per_frag, nr_frags, bytes_last_frag, frag_size;
+        int i, bytes_per_frag, nr_frags, bytes_last_frag, frag_size,
+            rts_required;
         unsigned long flags;
         struct net_device_stats *stats = &ieee->stats;
         int ether_type, encrypt, host_encrypt;
@@ -334,6 +336,13 @@ int ieee80211_xmit(struct sk_buff *skb, struct net_device *dev)
         else
                 bytes_last_frag = bytes_per_frag;
 
+        rts_required = (frag_size > ieee->rts
+                        && ieee->config & CFG_IEEE80211_RTS);
+        if (rts_required)
+                nr_frags++;
+        else
+                bytes_last_frag = bytes_per_frag;
+
         /* When we allocate the TXB we allocate enough space for the reserve
          * and full fragment bytes (bytes_per_frag doesn't include prefix,
          * postfix, header, FCS, etc.) */
@@ -346,7 +355,33 @@ int ieee80211_xmit(struct sk_buff *skb, struct net_device *dev)
         txb->encrypted = encrypt;
         txb->payload_size = bytes;
 
-        for (i = 0; i < nr_frags; i++) {
+        if (rts_required) {
+                skb_frag = txb->fragments[0];
+                frag_hdr =
+                    (struct ieee80211_hdr_3addr *)skb_put(skb_frag, hdr_len);
+
+                /*
+                 * Set header frame_ctl to the RTS.
+                 */
+                header.frame_ctl =
+                    cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
+                memcpy(frag_hdr, &header, hdr_len);
+
+                /*
+                 * Restore header frame_ctl to the original data setting.
+                 */
+                header.frame_ctl = cpu_to_le16(fc);
+
+                if (ieee->config &
+                    (CFG_IEEE80211_COMPUTE_FCS | CFG_IEEE80211_RESERVE_FCS))
+                        skb_put(skb_frag, 4);
+
+                txb->rts_included = 1;
+                i = 1;
+        } else
+                i = 0;
+
+        for (; i < nr_frags; i++) {
                 skb_frag = txb->fragments[i];
 
                 if (host_encrypt)