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mac80211: implement RANN processing and forwarding
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Process the RANN (Root Annoucement) Frame and try to find the HWMP
root station by sending a PREQ.

Signed-off-by: Rui Paulo <rpaulo@gmail.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Reviewed-by: Andrey Yurovsky <andrey@cozybit.com>
Tested-by: Brian Cavagnolo <brian@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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Rui Paulo authored and John W. Linville committed Nov 13, 2009
1 parent 41a2617 commit 90a5e16
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Showing 4 changed files with 91 additions and 8 deletions.
15 changes: 15 additions & 0 deletions include/linux/ieee80211.h
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Original file line number Diff line number Diff line change
Expand Up @@ -554,6 +554,20 @@ struct ieee80211_tim_ie {
u8 virtual_map[1];
} __attribute__ ((packed));

/**
* struct ieee80211_rann_ie
*
* This structure refers to "Root Announcement information element"
*/
struct ieee80211_rann_ie {
u8 rann_flags;
u8 rann_hopcount;
u8 rann_ttl;
u8 rann_addr[6];
u32 rann_seq;
u32 rann_metric;
} __attribute__ ((packed));

#define WLAN_SA_QUERY_TR_ID_LEN 2

struct ieee80211_mgmt {
Expand Down Expand Up @@ -1070,6 +1084,7 @@ enum ieee80211_eid {
WLAN_EID_PREQ = 68,
WLAN_EID_PREP = 69,
WLAN_EID_PERR = 70,
WLAN_EID_RANN = 49, /* compatible with FreeBSD */
/* 802.11h */
WLAN_EID_PWR_CONSTRAINT = 32,
WLAN_EID_PWR_CAPABILITY = 33,
Expand Down
1 change: 1 addition & 0 deletions net/mac80211/ieee80211_i.h
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Original file line number Diff line number Diff line change
Expand Up @@ -804,6 +804,7 @@ struct ieee802_11_elems {
u8 *preq;
u8 *prep;
u8 *perr;
struct ieee80211_rann_ie *rann;
u8 *ch_switch_elem;
u8 *country_elem;
u8 *pwr_constr_elem;
Expand Down
79 changes: 71 additions & 8 deletions net/mac80211/mesh_hwmp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -28,6 +28,8 @@
/* Reply and forward */
#define MP_F_RF 0x2

static void mesh_queue_preq(struct mesh_path *, u8);

static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
{
if (ae)
Expand Down Expand Up @@ -81,7 +83,8 @@ static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
enum mpath_frame_type {
MPATH_PREQ = 0,
MPATH_PREP,
MPATH_PERR
MPATH_PERR,
MPATH_RANN
};

static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
Expand Down Expand Up @@ -109,7 +112,8 @@ static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,

memcpy(mgmt->da, da, ETH_ALEN);
memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
/* BSSID is left zeroed, wildcard value */
/* BSSID == SA */
memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
mgmt->u.action.category = MESH_PATH_SEL_CATEGORY;
mgmt->u.action.u.mesh_action.action_code = MESH_PATH_SEL_ACTION;

Expand All @@ -126,6 +130,12 @@ static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
pos = skb_put(skb, 2 + ie_len);
*pos++ = WLAN_EID_PREP;
break;
case MPATH_RANN:
mhwmp_dbg("sending RANN from %pM\n", orig_addr);
ie_len = sizeof(struct ieee80211_rann_ie);
pos = skb_put(skb, 2 + ie_len);
*pos++ = WLAN_EID_RANN;
break;
default:
kfree_skb(skb);
return -ENOTSUPP;
Expand All @@ -143,18 +153,22 @@ static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
pos += ETH_ALEN;
memcpy(pos, &orig_dsn, 4);
pos += 4;
memcpy(pos, &lifetime, 4);
pos += 4;
if (action != MPATH_RANN) {
memcpy(pos, &lifetime, 4);
pos += 4;
}
memcpy(pos, &metric, 4);
pos += 4;
if (action == MPATH_PREQ) {
/* destination count */
*pos++ = 1;
*pos++ = dst_flags;
}
memcpy(pos, dst, ETH_ALEN);
pos += ETH_ALEN;
memcpy(pos, &dst_dsn, 4);
if (action != MPATH_RANN) {
memcpy(pos, dst, ETH_ALEN);
pos += ETH_ALEN;
memcpy(pos, &dst_dsn, 4);
}

ieee80211_tx_skb(sdata, skb, 1);
return 0;
Expand Down Expand Up @@ -610,6 +624,54 @@ static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
rcu_read_unlock();
}

static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt,
struct ieee80211_rann_ie *rann)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath;
u8 *ta;
u8 ttl, flags, hopcount;
u8 *orig_addr;
u32 orig_dsn, metric;

ta = mgmt->sa;
ttl = rann->rann_ttl;
if (ttl <= 1) {
ifmsh->mshstats.dropped_frames_ttl++;
return;
}
ttl--;
flags = rann->rann_flags;
orig_addr = rann->rann_addr;
orig_dsn = rann->rann_seq;
hopcount = rann->rann_hopcount;
metric = rann->rann_metric;
mhwmp_dbg("received RANN from %pM\n", orig_addr);

rcu_read_lock();
mpath = mesh_path_lookup(orig_addr, sdata);
if (!mpath) {
mesh_path_add(orig_addr, sdata);
mpath = mesh_path_lookup(orig_addr, sdata);
if (!mpath) {
rcu_read_unlock();
sdata->u.mesh.mshstats.dropped_frames_no_route++;
return;
}
mesh_queue_preq(mpath,
PREQ_Q_F_START | PREQ_Q_F_REFRESH);
}
if (mpath->dsn < orig_dsn) {
mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
cpu_to_le32(orig_dsn),
0, NULL, 0, sdata->dev->broadcast,
hopcount, ttl, 0, cpu_to_le32(metric),
0, sdata);
mpath->dsn = orig_dsn;
}
rcu_read_unlock();
}


void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
Expand Down Expand Up @@ -654,7 +716,8 @@ void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
return;
hwmp_perr_frame_process(sdata, mgmt, elems.perr);
}

if (elems.rann)
hwmp_rann_frame_process(sdata, mgmt, elems.rann);
}

/**
Expand Down
4 changes: 4 additions & 0 deletions net/mac80211/util.c
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Original file line number Diff line number Diff line change
Expand Up @@ -685,6 +685,10 @@ u32 ieee802_11_parse_elems_crc(u8 *start, size_t len,
elems->perr = pos;
elems->perr_len = elen;
break;
case WLAN_EID_RANN:
if (elen >= sizeof(struct ieee80211_rann_ie))
elems->rann = (void *)pos;
break;
case WLAN_EID_CHANNEL_SWITCH:
elems->ch_switch_elem = pos;
elems->ch_switch_elem_len = elen;
Expand Down

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