mac80211: fix mesh beacon format

Correct ordering of IEs in the mesh beacon while removing unneeded IEs
from mesh peering frames. Set privacy bit in capability info if security
is enabled. Add utility functions to aid in construction
of IEs and reduce code duplication.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 164 insertions, 59 deletions

diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index 29e9980c8e60..1990869033e1 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -204,36 +204,185 @@ int mesh_rmc_check(u8 *sa, struct ieee80211s_hdr *mesh_hdr,
         return 0;
 }
 
-void mesh_mgmt_ies_add(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
+int
+mesh_add_meshconf_ie(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
+{
+        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+        u8 *pos, neighbors;
+        u8 meshconf_len = sizeof(struct ieee80211_meshconf_ie);
+
+        if (skb_tailroom(skb) < 2 + meshconf_len)
+                return -ENOMEM;
+
+        pos = skb_put(skb, 2 + meshconf_len);
+        *pos++ = WLAN_EID_MESH_CONFIG;
+        *pos++ = meshconf_len;
+
+        /* Active path selection protocol ID */
+        *pos++ = ifmsh->mesh_pp_id;
+        /* Active path selection metric ID   */
+        *pos++ = ifmsh->mesh_pm_id;
+        /* Congestion control mode identifier */
+        *pos++ = ifmsh->mesh_cc_id;
+        /* Synchronization protocol identifier */
+        *pos++ = ifmsh->mesh_sp_id;
+        /* Authentication Protocol identifier */
+        *pos++ = ifmsh->mesh_auth_id;
+        /* Mesh Formation Info - number of neighbors */
+        neighbors = atomic_read(&ifmsh->mshstats.estab_plinks);
+        /* Number of neighbor mesh STAs or 15 whichever is smaller */
+        neighbors = (neighbors > 15) ? 15 : neighbors;
+        *pos++ = neighbors << 1;
+        /* Mesh capability */
+        ifmsh->accepting_plinks = mesh_plink_availables(sdata);
+        *pos = MESHCONF_CAPAB_FORWARDING;
+        *pos++ |= ifmsh->accepting_plinks ?
+            MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
+        *pos++ = 0x00;
+
+        return 0;
+}
+
+int
+mesh_add_meshid_ie(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
+{
+        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+        u8 *pos;
+
+        if (skb_tailroom(skb) < 2 + ifmsh->mesh_id_len)
+                return -ENOMEM;
+
+        pos = skb_put(skb, 2 + ifmsh->mesh_id_len);
+        *pos++ = WLAN_EID_MESH_ID;
+        *pos++ = ifmsh->mesh_id_len;
+        if (ifmsh->mesh_id_len)
+                memcpy(pos, ifmsh->mesh_id, ifmsh->mesh_id_len);
+
+        return 0;
+}
+
+int
+mesh_add_vendor_ies(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
+{
+        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+        u8 offset, len;
+        const u8 *data;
+
+        if (!ifmsh->ie || !ifmsh->ie_len)
+                return 0;
+
+        /* fast-forward to vendor IEs */
+        offset = ieee80211_ie_split_vendor(ifmsh->ie, ifmsh->ie_len, 0);
+
+        if (offset) {
+                len = ifmsh->ie_len - offset;
+                data = ifmsh->ie + offset;
+                if (skb_tailroom(skb) < len)
+                        return -ENOMEM;
+                memcpy(skb_put(skb, len), data, len);
+        }
+
+        return 0;
+}
+
+int
+mesh_add_rsn_ie(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
+{
+        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+        u8 len = 0;
+        const u8 *data;
+
+        if (!ifmsh->ie || !ifmsh->ie_len)
+                return 0;
+
+        /* find RSN IE */
+        data = ifmsh->ie;
+        while (data < ifmsh->ie + ifmsh->ie_len) {
+                if (*data == WLAN_EID_RSN) {
+                        len = data[1] + 2;
+                        break;
+                }
+                data++;
+        }
+
+        if (len) {
+                if (skb_tailroom(skb) < len)
+                        return -ENOMEM;
+                memcpy(skb_put(skb, len), data, len);
+        }
+
+        return 0;
+}
+
+int
+mesh_add_srates_ie(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
 {
         struct ieee80211_local *local = sdata->local;
         struct ieee80211_supported_band *sband;
-        u8 *pos;
-        int len, i, rate;
-        u8 neighbors;
+        int rate;
+        u8 i, rates, *pos;
 
         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
-        len = sband->n_bitrates;
-        if (len > 8)
-                len = 8;
-        pos = skb_put(skb, len + 2);
+        rates = sband->n_bitrates;
+        if (rates > 8)
+                rates = 8;
+
+        if (skb_tailroom(skb) < rates + 2)
+                return -ENOMEM;
+
+        pos = skb_put(skb, rates + 2);
         *pos++ = WLAN_EID_SUPP_RATES;
-        *pos++ = len;
-        for (i = 0; i < len; i++) {
+        *pos++ = rates;
+        for (i = 0; i < rates; i++) {
                 rate = sband->bitrates[i].bitrate;
                 *pos++ = (u8) (rate / 5);
         }
 
-        if (sband->n_bitrates > len) {
-                pos = skb_put(skb, sband->n_bitrates - len + 2);
+        return 0;
+}
+
+int
+mesh_add_ext_srates_ie(struct sk_buff *skb,
+                       struct ieee80211_sub_if_data *sdata)
+{
+        struct ieee80211_local *local = sdata->local;
+        struct ieee80211_supported_band *sband;
+        int rate;
+        u8 i, exrates, *pos;
+
+        sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
+        exrates = sband->n_bitrates;
+        if (exrates > 8)
+                exrates -= 8;
+        else
+                exrates = 0;
+
+        if (skb_tailroom(skb) < exrates + 2)
+                return -ENOMEM;
+
+        if (exrates) {
+                pos = skb_put(skb, exrates + 2);
                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
-                *pos++ = sband->n_bitrates - len;
-                for (i = len; i < sband->n_bitrates; i++) {
+                *pos++ = exrates;
+                for (i = 8; i < sband->n_bitrates; i++) {
                         rate = sband->bitrates[i].bitrate;
                         *pos++ = (u8) (rate / 5);
                 }
         }
+        return 0;
+}
+
+int mesh_add_ds_params_ie(struct sk_buff *skb,
+                          struct ieee80211_sub_if_data *sdata)
+{
+        struct ieee80211_local *local = sdata->local;
+        struct ieee80211_supported_band *sband;
+        u8 *pos;
+
+        if (skb_tailroom(skb) < 3)
+                return -ENOMEM;
 
+        sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
         if (sband->band == IEEE80211_BAND_2GHZ) {
                 pos = skb_put(skb, 2 + 1);
                 *pos++ = WLAN_EID_DS_PARAMS;
@@ -241,53 +390,9 @@ void mesh_mgmt_ies_add(struct sk_buff *skb, struct ieee80211_sub_if_data *sdata)
                 *pos++ = ieee80211_frequency_to_channel(local->hw.conf.channel->center_freq);
         }
 
-        pos = skb_put(skb, 2 + sdata->u.mesh.mesh_id_len);
-        *pos++ = WLAN_EID_MESH_ID;
-        *pos++ = sdata->u.mesh.mesh_id_len;
-        if (sdata->u.mesh.mesh_id_len)
-                memcpy(pos, sdata->u.mesh.mesh_id, sdata->u.mesh.mesh_id_len);
-
-        pos = skb_put(skb, 2 + sizeof(struct ieee80211_meshconf_ie));
-        *pos++ = WLAN_EID_MESH_CONFIG;
-        *pos++ = sizeof(struct ieee80211_meshconf_ie);
-
-        /* Active path selection protocol ID */
-        *pos++ = sdata->u.mesh.mesh_pp_id;
-
-        /* Active path selection metric ID   */
-        *pos++ = sdata->u.mesh.mesh_pm_id;
-
-        /* Congestion control mode identifier */
-        *pos++ = sdata->u.mesh.mesh_cc_id;
-
-        /* Synchronization protocol identifier */
-        *pos++ = sdata->u.mesh.mesh_sp_id;
-
-        /* Authentication Protocol identifier */
-        *pos++ = sdata->u.mesh.mesh_auth_id;
-
-        /* Mesh Formation Info - number of neighbors */
-        neighbors = atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
-        /* Number of neighbor mesh STAs or 15 whichever is smaller */
-        neighbors = (neighbors > 15) ? 15 : neighbors;
-        *pos++ = neighbors << 1;
-
-        /* Mesh capability */
-        sdata->u.mesh.accepting_plinks = mesh_plink_availables(sdata);
-        *pos = MESHCONF_CAPAB_FORWARDING;
-        *pos++ |= sdata->u.mesh.accepting_plinks ?
-            MESHCONF_CAPAB_ACCEPT_PLINKS : 0x00;
-        *pos++ = 0x00;
-
-        if (sdata->u.mesh.ie) {
-                int len = sdata->u.mesh.ie_len;
-                const u8 *data = sdata->u.mesh.ie;
-                if (skb_tailroom(skb) > len)
-                        memcpy(skb_put(skb, len), data, len);
-        }
+        return 0;
 }
 
-
 static void ieee80211_mesh_path_timer(unsigned long data)
 {
         struct ieee80211_sub_if_data *sdata =