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mac80211: update PERR frame format
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Update the PERR IE frame format according to latest draft (3.03).

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 90a5e16 commit d611f06
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Showing 3 changed files with 60 additions and 13 deletions.
9 changes: 7 additions & 2 deletions net/mac80211/mesh.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -210,6 +210,11 @@ struct mesh_rmc {
#define MESH_PATH_SEL_CATEGORY 32
#define MESH_PATH_SEL_ACTION 0

/* PERR reason codes */
#define PEER_RCODE_UNSPECIFIED 11
#define PERR_RCODE_NO_ROUTE 12
#define PERR_RCODE_DEST_UNREACH 13

/* Public interfaces */
/* Various */
int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
Expand Down Expand Up @@ -275,8 +280,8 @@ void mesh_mpp_table_grow(void);
u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata,
struct mesh_table *tbl);
/* Mesh paths */
int mesh_path_error_tx(u8 *dest, __le32 dest_dsn, u8 *ra,
struct ieee80211_sub_if_data *sdata);
int mesh_path_error_tx(u8 ttl, u8 *dest, __le32 dest_dsn, __le16 dest_rcode,
u8 *ra, struct ieee80211_sub_if_data *sdata);
void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
void mesh_path_flush_pending(struct mesh_path *mpath);
void mesh_path_tx_pending(struct mesh_path *mpath);
Expand Down
58 changes: 49 additions & 9 deletions net/mac80211/mesh_hwmp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,10 @@
#define MP_F_DO 0x1
/* Reply and forward */
#define MP_F_RF 0x2
/* Unknown Sequence Number */
#define MP_F_USN 0x01
/* Reason code Present */
#define MP_F_RCODE 0x02

static void mesh_queue_preq(struct mesh_path *, u8);

Expand All @@ -37,6 +41,13 @@ static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
return get_unaligned_le32(preq_elem + offset);
}

static inline u32 u16_field_get(u8 *preq_elem, int offset, bool ae)
{
if (ae)
offset += 6;
return get_unaligned_le16(preq_elem + offset);
}

/* HWMP IE processing macros */
#define AE_F (1<<6)
#define AE_F_SET(x) (*x & AE_F)
Expand All @@ -63,8 +74,11 @@ static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
#define PREP_IE_DST_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21)
#define PREP_IE_DST_DSN(x) u32_field_get(x, 27, AE_F_SET(x));

#define PERR_IE_DST_ADDR(x) (x + 2)
#define PERR_IE_DST_DSN(x) u32_field_get(x, 8, 0);
#define PERR_IE_TTL(x) (*(x))
#define PERR_IE_DST_FLAGS(x) (*(x + 2))
#define PERR_IE_DST_ADDR(x) (x + 3)
#define PERR_IE_DST_DSN(x) u32_field_get(x, 9, 0);
#define PERR_IE_DST_RCODE(x) u16_field_get(x, 13, 0);

#define MSEC_TO_TU(x) (x*1000/1024)
#define DSN_GT(x, y) ((long) (y) - (long) (x) < 0)
Expand Down Expand Up @@ -181,8 +195,8 @@ static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
* @dst_dsn: dsn of the broken destination
* @ra: node this frame is addressed to
*/
int mesh_path_error_tx(u8 *dst, __le32 dst_dsn, u8 *ra,
struct ieee80211_sub_if_data *sdata)
int mesh_path_error_tx(u8 ttl, u8 *dst, __le32 dst_dsn, __le16 dst_rcode,
u8 *ra, struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
struct sk_buff *skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400);
Expand All @@ -207,17 +221,29 @@ int mesh_path_error_tx(u8 *dst, __le32 dst_dsn, u8 *ra,
/* BSSID is left zeroed, wildcard value */
mgmt->u.action.category = MESH_PATH_SEL_CATEGORY;
mgmt->u.action.u.mesh_action.action_code = MESH_PATH_SEL_ACTION;
ie_len = 12;
ie_len = 15;
pos = skb_put(skb, 2 + ie_len);
*pos++ = WLAN_EID_PERR;
*pos++ = ie_len;
/* mode flags, reserved */
*pos++ = 0;
/* ttl */
*pos++ = MESH_TTL;
/* number of destinations */
*pos++ = 1;
/*
* flags bit, bit 1 is unset if we know the sequence number and
* bit 2 is set if we have a reason code
*/
*pos = 0;
if (!dst_dsn)
*pos |= MP_F_USN;
if (dst_rcode)
*pos |= MP_F_RCODE;
pos++;
memcpy(pos, dst, ETH_ALEN);
pos += ETH_ALEN;
memcpy(pos, &dst_dsn, 4);
pos += 4;
memcpy(pos, &dst_rcode, 2);

ieee80211_tx_skb(sdata, skb, 1);
return 0;
Expand Down Expand Up @@ -598,13 +624,26 @@ static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata,
static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt, u8 *perr_elem)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct mesh_path *mpath;
u8 ttl;
u8 *ta, *dst_addr;
u8 dst_flags;
u32 dst_dsn;
u16 dst_rcode;

ta = mgmt->sa;
ttl = PERR_IE_TTL(perr_elem);
if (ttl <= 1) {
ifmsh->mshstats.dropped_frames_ttl++;
return;
}
ttl--;
dst_flags = PERR_IE_DST_FLAGS(perr_elem);
dst_addr = PERR_IE_DST_ADDR(perr_elem);
dst_dsn = PERR_IE_DST_DSN(perr_elem);
dst_rcode = PERR_IE_DST_RCODE(perr_elem);

rcu_read_lock();
mpath = mesh_path_lookup(dst_addr, sdata);
if (mpath) {
Expand All @@ -616,7 +655,8 @@ static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
mpath->flags &= ~MESH_PATH_ACTIVE;
mpath->dsn = dst_dsn;
spin_unlock_bh(&mpath->state_lock);
mesh_path_error_tx(dst_addr, cpu_to_le32(dst_dsn),
mesh_path_error_tx(ttl, dst_addr, cpu_to_le32(dst_dsn),
cpu_to_le16(dst_rcode),
sdata->dev->broadcast, sdata);
} else
spin_unlock_bh(&mpath->state_lock);
Expand Down Expand Up @@ -711,7 +751,7 @@ void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
last_hop_metric);
}
if (elems.perr) {
if (elems.perr_len != 12)
if (elems.perr_len != 15)
/* Right now we support only one destination per PERR */
return;
hwmp_perr_frame_process(sdata, mgmt, elems.perr);
Expand Down
6 changes: 4 additions & 2 deletions net/mac80211/mesh_pathtbl.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -465,8 +465,9 @@ void mesh_plink_broken(struct sta_info *sta)
mpath->flags &= ~MESH_PATH_ACTIVE;
++mpath->dsn;
spin_unlock_bh(&mpath->state_lock);
mesh_path_error_tx(mpath->dst,
mesh_path_error_tx(MESH_TTL, mpath->dst,
cpu_to_le32(mpath->dsn),
PERR_RCODE_DEST_UNREACH,
sdata->dev->broadcast, sdata);
} else
spin_unlock_bh(&mpath->state_lock);
Expand Down Expand Up @@ -611,7 +612,8 @@ void mesh_path_discard_frame(struct sk_buff *skb,
mpath = mesh_path_lookup(da, sdata);
if (mpath)
dsn = ++mpath->dsn;
mesh_path_error_tx(skb->data, cpu_to_le32(dsn), ra, sdata);
mesh_path_error_tx(MESH_TTL, skb->data, cpu_to_le32(dsn),
PERR_RCODE_NO_ROUTE, ra, sdata);
}

kfree_skb(skb);
Expand Down

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