mac80211: support for mesh interfaces in mac80211 data path

This changes the TX/RX paths in mac80211 to support mesh interfaces.
This code will be cleaned up later again before being enabled.

Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 246 insertions, 33 deletions

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index b7eeae0d3956..cc4a896c617f 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -20,6 +20,9 @@
 
 #include "ieee80211_i.h"
 #include "ieee80211_led.h"
+#ifdef CONFIG_MAC80211_MESH
+#include "mesh.h"
+#endif
 #include "wep.h"
 #include "wpa.h"
 #include "tkip.h"
@@ -390,10 +393,60 @@ ieee80211_rx_h_passive_scan(struct ieee80211_txrx_data *rx)
         return RX_CONTINUE;
 }
 
+#ifdef CONFIG_MAC80211_MESH
+#define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))
+static ieee80211_rx_result
+ieee80211_rx_mesh_check(struct ieee80211_txrx_data *rx)
+{
+        int hdrlen = ieee80211_get_hdrlen(rx->fc);
+        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
+        if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA) {
+                if (!((rx->fc & IEEE80211_FCTL_FROMDS) &&
+                      (rx->fc & IEEE80211_FCTL_TODS)))
+                        return RX_DROP_MONITOR;
+                if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
+                        return RX_DROP_MONITOR;
+        }
+
+        /* If there is not an established peer link and this is not a peer link
+         * establisment frame, beacon or probe, drop the frame.
+         */
+
+        if (!rx->sta || rx->sta->plink_state != ESTAB) {
+                struct ieee80211_mgmt *mgmt;
+                if ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT)
+                        return RX_DROP_MONITOR;
+
+                switch (rx->fc & IEEE80211_FCTL_STYPE) {
+                case IEEE80211_STYPE_ACTION:
+                        mgmt = (struct ieee80211_mgmt *)hdr;
+                        if (mgmt->u.action.category != PLINK_CATEGORY)
+                                return RX_DROP_MONITOR;
+                        /* fall through on else */
+                case IEEE80211_STYPE_PROBE_REQ:
+                case IEEE80211_STYPE_PROBE_RESP:
+                case IEEE80211_STYPE_BEACON:
+                        return RX_CONTINUE;
+                        break;
+                default:
+                        return RX_DROP_MONITOR;
+                }
+
+         } else if ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
+                    is_broadcast_ether_addr(hdr->addr1) &&
+                    mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->dev))
+                return RX_DROP_MONITOR;
+        else
+                return RX_CONTINUE;
+}
+#endif
+
+
 static ieee80211_rx_result
 ieee80211_rx_h_check(struct ieee80211_txrx_data *rx)
 {
         struct ieee80211_hdr *hdr;
+
         hdr = (struct ieee80211_hdr *) rx->skb->data;
 
         /* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
@@ -423,6 +476,12 @@ ieee80211_rx_h_check(struct ieee80211_txrx_data *rx)
          * deauth/disassoc frames when needed. In addition, hostapd is
          * responsible for filtering on both auth and assoc states.
          */
+
+#ifdef CONFIG_MAC80211_MESH
+        if (rx->sdata->vif.type == IEEE80211_IF_TYPE_MESH_POINT)
+                return ieee80211_rx_mesh_check(rx);
+#endif
+
         if (unlikely(((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA ||
                       ((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL &&
                        (rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)) &&
@@ -657,6 +716,8 @@ ieee80211_rx_h_sta_process(struct ieee80211_txrx_data *rx)
                 /* Update last_rx only for unicast frames in order to prevent
                  * the Probe Request frames (the only broadcast frames from a
                  * STA in infrastructure mode) from keeping a connection alive.
+                 * Mesh beacons will update last_rx when if they are found to
+                 * match the current local configuration when processed.
                  */
                 sta->last_rx = jiffies;
         }
@@ -1050,6 +1111,23 @@ ieee80211_data_to_8023(struct ieee80211_txrx_data *rx)
 
         hdrlen = ieee80211_get_hdrlen(fc);
 
+#ifdef CONFIG_MAC80211_MESH
+        if (sdata->vif.type == IEEE80211_IF_TYPE_MESH_POINT) {
+                int meshhdrlen = ieee80211_get_mesh_hdrlen(
+                                (struct ieee80211s_hdr *) (skb->data + hdrlen));
+                /* Copy on cb:
+                 *  - mesh header: to be used for mesh forwarding
+                 * decision. It will also be used as mesh header template at
+                 * tx.c:ieee80211_subif_start_xmit() if interface
+                 * type is mesh and skb->pkt_type == PACKET_OTHERHOST
+                 *  - ta: to be used if a RERR needs to be sent.
+                 */
+                memcpy(skb->cb, skb->data + hdrlen, meshhdrlen);
+                memcpy(MESH_PREQ(skb), hdr->addr2, ETH_ALEN);
+                hdrlen += meshhdrlen;
+        }
+#endif
+
         /* convert IEEE 802.11 header + possible LLC headers into Ethernet
          * header
          * IEEE 802.11 address fields:
@@ -1083,9 +1161,10 @@ ieee80211_data_to_8023(struct ieee80211_txrx_data *rx)
                 memcpy(dst, hdr->addr3, ETH_ALEN);
                 memcpy(src, hdr->addr4, ETH_ALEN);
 
-                if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_WDS)) {
-                        if (net_ratelimit())
-                                printk(KERN_DEBUG "%s: dropped FromDS&ToDS "
+                 if (unlikely(sdata->vif.type != IEEE80211_IF_TYPE_WDS &&
+                             sdata->vif.type != IEEE80211_IF_TYPE_MESH_POINT)) {
+                         if (net_ratelimit())
+                                 printk(KERN_DEBUG "%s: dropped FromDS&ToDS "
                                        "frame (RA=%s TA=%s DA=%s SA=%s)\n",
                                        rx->dev->name,
                                        print_mac(mac, hdr->addr1),
@@ -1227,6 +1306,39 @@ ieee80211_deliver_skb(struct ieee80211_txrx_data *rx)
                 }
         }
 
+#ifdef CONFIG_MAC80211_MESH
+        /* Mesh forwarding */
+        if (sdata->vif.type == IEEE80211_IF_TYPE_MESH_POINT) {
+                u8 *mesh_ttl = &((struct ieee80211s_hdr *)skb->cb)->ttl;
+                (*mesh_ttl)--;
+
+                if (is_multicast_ether_addr(skb->data)) {
+                        if (*mesh_ttl > 0) {
+                                xmit_skb = skb_copy(skb, GFP_ATOMIC);
+                                if (!xmit_skb && net_ratelimit())
+                                        printk(KERN_DEBUG "%s: failed to clone "
+                                               "multicast frame\n", dev->name);
+                                else
+                                        xmit_skb->pkt_type = PACKET_OTHERHOST;
+                        } else
+                                sdata->u.sta.mshstats.dropped_frames_ttl++;
+
+                } else if (skb->pkt_type != PACKET_OTHERHOST &&
+                        compare_ether_addr(dev->dev_addr, skb->data) != 0) {
+                        if (*mesh_ttl == 0) {
+                                sdata->u.sta.mshstats.dropped_frames_ttl++;
+                                dev_kfree_skb(skb);
+                                skb = NULL;
+                        } else {
+                                xmit_skb = skb;
+                                xmit_skb->pkt_type = PACKET_OTHERHOST;
+                                if (!(dev->flags & IFF_PROMISC))
+                                        skb  = NULL;
+                        }
+                }
+        }
+#endif
+
         if (skb) {
                 /* deliver to local stack */
                 skb->protocol = eth_type_trans(skb, dev);
@@ -1444,7 +1556,8 @@ ieee80211_rx_h_mgmt(struct ieee80211_txrx_data *rx)
 
         sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
         if ((sdata->vif.type == IEEE80211_IF_TYPE_STA ||
-             sdata->vif.type == IEEE80211_IF_TYPE_IBSS) &&
+             sdata->vif.type == IEEE80211_IF_TYPE_IBSS ||
+             sdata->vif.type == IEEE80211_IF_TYPE_MESH_POINT) &&
             !(sdata->flags & IEEE80211_SDATA_USERSPACE_MLME))
                 ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->u.rx.status);
         else
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index 1cd58e01f1ee..fc1ffb55ed5c 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -26,6 +26,9 @@
 
 #include "ieee80211_i.h"
 #include "ieee80211_led.h"
+#ifdef CONFIG_MAC80211_MESH
+#include "mesh.h"
+#endif
 #include "wep.h"
 #include "wpa.h"
 #include "wme.h"
@@ -249,6 +252,9 @@ ieee80211_tx_h_check_assoc(struct ieee80211_txrx_data *tx)
              (tx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PROBE_REQ))
                 return TX_DROP;
 
+        if (tx->sdata->vif.type == IEEE80211_IF_TYPE_MESH_POINT)
+                return TX_CONTINUE;
+
         if (tx->flags & IEEE80211_TXRXD_TXPS_BUFFERED)
                 return TX_CONTINUE;
 
@@ -1384,8 +1390,9 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb,
         struct ieee80211_tx_packet_data *pkt_data;
         struct ieee80211_sub_if_data *sdata;
         int ret = 1, head_need;
-        u16 ethertype, hdrlen, fc;
+        u16 ethertype, hdrlen,  meshhdrlen = 0, fc;
         struct ieee80211_hdr hdr;
+        struct ieee80211s_hdr mesh_hdr;
         const u8 *encaps_data;
         int encaps_len, skip_header_bytes;
         int nh_pos, h_pos;
@@ -1427,6 +1434,37 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb,
                 memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
                 hdrlen = 30;
                 break;
+#ifdef CONFIG_MAC80211_MESH
+        case IEEE80211_IF_TYPE_MESH_POINT:
+                fc |= IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS;
+                /* RA TA DA SA */
+                if (is_multicast_ether_addr(skb->data))
+                        memcpy(hdr.addr1, skb->data, ETH_ALEN);
+                else if (mesh_nexthop_lookup(hdr.addr1, skb, dev))
+                                return 0;
+                memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
+                memcpy(hdr.addr3, skb->data, ETH_ALEN);
+                memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
+                if (skb->pkt_type == PACKET_OTHERHOST) {
+                        /* Forwarded frame, keep mesh ttl and seqnum */
+                        struct ieee80211s_hdr *prev_meshhdr;
+                        prev_meshhdr = ((struct ieee80211s_hdr *)skb->cb);
+                        meshhdrlen = ieee80211_get_mesh_hdrlen(prev_meshhdr);
+                        memcpy(&mesh_hdr, prev_meshhdr, meshhdrlen);
+                        sdata->u.sta.mshstats.fwded_frames++;
+                } else {
+                        if (!sdata->u.sta.mshcfg.dot11MeshTTL) {
+                                /* Do not send frames with mesh_ttl == 0 */
+                                sdata->u.sta.mshstats.dropped_frames_ttl++;
+                                ret = 0;
+                                goto fail;
+                        }
+                        meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr,
+                                        sdata);
+                }
+                hdrlen = 30;
+                break;
+#endif
         case IEEE80211_IF_TYPE_STA:
                 fc |= IEEE80211_FCTL_TODS;
                 /* BSSID SA DA */
@@ -1471,8 +1509,8 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb,
          * EAPOL frames from the local station.
          */
         if (unlikely(!is_multicast_ether_addr(hdr.addr1) &&
-                     !(sta_flags & WLAN_STA_AUTHORIZED) &&
-                     !(ethertype == ETH_P_PAE &&
+                      !(sta_flags & WLAN_STA_AUTHORIZED) &&
+                      !(ethertype == ETH_P_PAE &&
                        compare_ether_addr(dev->dev_addr,
                                           skb->data + ETH_ALEN) == 0))) {
 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
@@ -1525,7 +1563,7 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb,
          * build in headroom in __dev_alloc_skb() (linux/skbuff.h) and
          * alloc_skb() (net/core/skbuff.c)
          */
-        head_need = hdrlen + encaps_len + local->tx_headroom;
+        head_need = hdrlen + encaps_len + meshhdrlen + local->tx_headroom;
         head_need -= skb_headroom(skb);
 
         /* We are going to modify skb data, so make a copy of it if happens to
@@ -1559,6 +1597,12 @@ int ieee80211_subif_start_xmit(struct sk_buff *skb,
                 h_pos += encaps_len;
         }
 
+        if (meshhdrlen > 0) {
+                memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
+                nh_pos += meshhdrlen;
+                h_pos += meshhdrlen;
+        }
+
         if (fc & IEEE80211_STYPE_QOS_DATA) {
                 __le16 *qos_control;
 
@@ -1734,6 +1778,40 @@ static void ieee80211_beacon_add_tim(struct ieee80211_local *local,
         read_unlock_bh(&local->sta_lock);
 }
 
+#ifdef CONFIG_MAC80211_MESH
+static struct sk_buff *ieee80211_mesh_beacon_get(struct net_device *dev)
+{
+        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+        struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
+        struct ieee80211_mgmt *mgmt;
+        u8 *pos;
+
+        if (!skb)
+                return NULL;
+        skb_reserve(skb, local->hw.extra_tx_headroom);
+        mgmt = (struct ieee80211_mgmt *)
+                skb_put(skb, 24 + sizeof(mgmt->u.beacon));
+        memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
+        mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT,
+                                           IEEE80211_STYPE_BEACON);
+        memset(mgmt->da, 0xff, ETH_ALEN);
+        memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN);
+        /* BSSID is left zeroed, wildcard value */
+        mgmt->u.beacon.beacon_int =
+                cpu_to_le16(local->hw.conf.beacon_int);
+        mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */
+
+        pos = skb_put(skb, 2);
+        *pos++ = WLAN_EID_SSID;
+        *pos++ = 0x0;
+
+        mesh_mgmt_ies_add(skb, dev);
+
+        return skb;
+}
+#endif
+
+
 struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
                                      struct ieee80211_vif *vif,
                                      struct ieee80211_tx_control *control)
@@ -1746,6 +1824,8 @@ struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
         struct rate_selection rsel;
         struct beacon_data *beacon;
         struct ieee80211_supported_band *sband;
+        int *num_beacons;
+        int err = 0;
 
         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
 
@@ -1753,11 +1833,51 @@ struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
 
         sdata = vif_to_sdata(vif);
         bdev = sdata->dev;
-        ap = &sdata->u.ap;
 
-        beacon = rcu_dereference(ap->beacon);
+        switch (sdata->vif.type) {
+        case IEEE80211_IF_TYPE_AP:
+                ap = &sdata->u.ap;
+                beacon = rcu_dereference(ap->beacon);
+                if (!ap || !beacon) {
+                        err = -1;
+                        break;
+                }
+
+                /* headroom, head length, tail length and maximum TIM length */
+                skb = dev_alloc_skb(local->tx_headroom + beacon->head_len +
+                                    beacon->tail_len + 256);
+                if (!skb)
+                        goto out;
+
+                skb_reserve(skb, local->tx_headroom);
+                memcpy(skb_put(skb, beacon->head_len), beacon->head,
+                       beacon->head_len);
 
-        if (!ap || sdata->vif.type != IEEE80211_IF_TYPE_AP || !beacon) {
+                ieee80211_include_sequence(sdata,
+                                           (struct ieee80211_hdr *)skb->data);
+
+                ieee80211_beacon_add_tim(local, ap, skb, beacon);
+
+                if (beacon->tail)
+                        memcpy(skb_put(skb, beacon->tail_len), beacon->tail,
+                               beacon->tail_len);
+
+                num_beacons = &ap->num_beacons;
+                break;
+
+#ifdef CONFIG_MAC80211_MESH
+        case IEEE80211_IF_TYPE_MESH_POINT:
+                skb = ieee80211_mesh_beacon_get(bdev);
+                num_beacons = &sdata->u.sta.num_beacons;
+                break;
+#endif
+
+        default:
+                err = -1;
+                break;
+        }
+
+        if (err) {
 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
                 if (net_ratelimit())
                         printk(KERN_DEBUG "no beacon data avail for %s\n",
@@ -1767,24 +1887,6 @@ struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
                 goto out;
         }
 
-        /* headroom, head length, tail length and maximum TIM length */
-        skb = dev_alloc_skb(local->tx_headroom + beacon->head_len +
-                            beacon->tail_len + 256);
-        if (!skb)
-                goto out;
-
-        skb_reserve(skb, local->tx_headroom);
-        memcpy(skb_put(skb, beacon->head_len), beacon->head,
-               beacon->head_len);
-
-        ieee80211_include_sequence(sdata, (struct ieee80211_hdr *)skb->data);
-
-        ieee80211_beacon_add_tim(local, ap, skb, beacon);
-
-        if (beacon->tail)
-                memcpy(skb_put(skb, beacon->tail_len), beacon->tail,
-                       beacon->tail_len);
-
         if (control) {
                 rate_control_get_rate(local->mdev, sband, skb, &rsel);
                 if (!rsel.rate) {
@@ -1808,10 +1910,8 @@ struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
                 control->retry_limit = 1;
                 control->flags |= IEEE80211_TXCTL_CLEAR_PS_FILT;
         }
-
-        ap->num_beacons++;
-
- out:
+        (*num_beacons)++;
+out:
         rcu_read_unlock();
         return skb;
 }