diff options
| -rw-r--r-- | net/mac80211/mesh_hwmp.c | 862 |
1 files changed, 862 insertions, 0 deletions
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c new file mode 100644 index 000000000000..9a501aae48eb --- /dev/null +++ b/net/mac80211/mesh_hwmp.c @@ -0,0 +1,862 @@ +/* + * Copyright (c) 2008 open80211s Ltd. + * Author: Luis Carlos Cobo <luisca@cozybit.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include "mesh.h" + +#define IEEE80211_FC(type, stype) cpu_to_le16(type | stype) + +#define TEST_FRAME_LEN 8192 +#define MAX_METRIC 0xffffffff +#define ARITH_SHIFT 8 + +/* Number of frames buffered per destination for unresolved destinations */ +#define MESH_FRAME_QUEUE_LEN 10 +#define MAX_PREQ_QUEUE_LEN 64 + +/* Destination only */ +#define MP_F_DO 0x1 +/* Reply and forward */ +#define MP_F_RF 0x2 + +/* HWMP IE processing macros */ +#define AE_F (1<<6) +#define AE_F_SET(x) (*x & AE_F) +#define PREQ_IE_FLAGS(x) (*(x)) +#define PREQ_IE_HOPCOUNT(x) (*(x + 1)) +#define PREQ_IE_TTL(x) (*(x + 2)) +#define PREQ_IE_PREQ_ID(x) le32_to_cpu(*((u32 *) (x + 3))) +#define PREQ_IE_ORIG_ADDR(x) (x + 7) +#define PREQ_IE_ORIG_DSN(x) le32_to_cpu(*((u32 *) (x + 13))) +#define PREQ_IE_LIFETIME(x) le32_to_cpu(*((u32 *) \ + (AE_F_SET(x) ? x + 23 : x + 17))) +#define PREQ_IE_METRIC(x) le32_to_cpu(*((u32 *) \ + (AE_F_SET(x) ? x + 27 : x + 21))) +#define PREQ_IE_DST_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26)) +#define PREQ_IE_DST_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27) +#define PREQ_IE_DST_DSN(x) le32_to_cpu(*((u32 *) \ + (AE_F_SET(x) ? x + 39 : x + 33))) + + +#define PREP_IE_FLAGS(x) PREQ_IE_FLAGS(x) +#define PREP_IE_HOPCOUNT(x) PREQ_IE_HOPCOUNT(x) +#define PREP_IE_TTL(x) PREQ_IE_TTL(x) +#define PREP_IE_ORIG_ADDR(x) (x + 3) +#define PREP_IE_ORIG_DSN(x) le32_to_cpu(*((u32 *) (x + 9))) +#define PREP_IE_LIFETIME(x) le32_to_cpu(*((u32 *) \ + (AE_F_SET(x) ? x + 19 : x + 13))) +#define PREP_IE_METRIC(x) le32_to_cpu(*((u32 *) \ + (AE_F_SET(x) ? x + 23 : x + 17))) +#define PREP_IE_DST_ADDR(x) (AE_F_SET(x) ? x + 27 : x + 21) +#define PREP_IE_DST_DSN(x) le32_to_cpu(*((u32 *) \ + (AE_F_SET(x) ? x + 33 : x + 27))) + +#define PERR_IE_DST_ADDR(x) (x + 2) +#define PERR_IE_DST_DSN(x) le32_to_cpu(*((u32 *) (x + 8))) + +#define TU_TO_EXP_TIME(x) (jiffies + msecs_to_jiffies(x * 1024 / 1000)) +#define MSEC_TO_TU(x) (x*1000/1024) +#define DSN_GT(x, y) ((long) (y) - (long) (x) < 0) +#define DSN_LT(x, y) ((long) (x) - (long) (y) < 0) + +#define net_traversal_jiffies(s) \ + msecs_to_jiffies(s->u.sta.mshcfg.dot11MeshHWMPnetDiameterTraversalTime) +#define default_lifetime(s) \ + MSEC_TO_TU(s->u.sta.mshcfg.dot11MeshHWMPactivePathTimeout) +#define min_preq_int_jiff(s) \ + (msecs_to_jiffies(s->u.sta.mshcfg.dot11MeshHWMPpreqMinInterval)) +#define max_preq_retries(s) (s->u.sta.mshcfg.dot11MeshHWMPmaxPREQretries) +#define disc_timeout_jiff(s) \ + msecs_to_jiffies(sdata->u.sta.mshcfg.min_discovery_timeout) + +enum mpath_frame_type { + MPATH_PREQ = 0, + MPATH_PREP, + MPATH_PERR +}; + +static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags, + u8 *orig_addr, __le32 orig_dsn, u8 dst_flags, u8 *dst, + __le32 dst_dsn, u8 *da, u8 hop_count, u8 ttl, __le32 lifetime, + __le32 metric, __le32 preq_id, 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; + int ie_len; + + if (!skb) + return -1; + skb_reserve(skb, local->hw.extra_tx_headroom); + /* 25 is the size of the common mgmt part (24) plus the size of the + * common action part (1) + */ + mgmt = (struct ieee80211_mgmt *) + skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action)); + memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action)); + mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT, + IEEE80211_STYPE_ACTION); + + memcpy(mgmt->da, da, ETH_ALEN); + memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN); + /* BSSID is left zeroed, wildcard value */ + mgmt->u.action.category = MESH_PATH_SEL_CATEGORY; + mgmt->u.action.u.mesh_action.action_code = action; + + switch (action) { + case MPATH_PREQ: + ie_len = 37; + pos = skb_put(skb, 2 + ie_len); + *pos++ = WLAN_EID_PREQ; + break; + case MPATH_PREP: + ie_len = 31; + pos = skb_put(skb, 2 + ie_len); + *pos++ = WLAN_EID_PREP; + break; + default: + kfree(skb); + return -ENOTSUPP; + break; + } + *pos++ = ie_len; + *pos++ = flags; + *pos++ = hop_count; + *pos++ = ttl; + if (action == MPATH_PREQ) { + memcpy(pos, &preq_id, 4); + pos += 4; + } + memcpy(pos, orig_addr, ETH_ALEN); + pos += ETH_ALEN; + memcpy(pos, &orig_dsn, 4); + pos += 4; + 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); + + ieee80211_sta_tx(dev, skb, 0); + return 0; +} + +/** + * mesh_send_path error - Sends a PERR mesh management frame + * + * @dst: broken destination + * @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 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; + int ie_len; + + if (!skb) + return -1; + skb_reserve(skb, local->hw.extra_tx_headroom); + /* 25 is the size of the common mgmt part (24) plus the size of the + * common action part (1) + */ + mgmt = (struct ieee80211_mgmt *) + skb_put(skb, 25 + sizeof(mgmt->u.action.u.mesh_action)); + memset(mgmt, 0, 25 + sizeof(mgmt->u.action.u.mesh_action)); + mgmt->frame_control = IEEE80211_FC(IEEE80211_FTYPE_MGMT, + IEEE80211_STYPE_ACTION); + + memcpy(mgmt->da, ra, ETH_ALEN); + memcpy(mgmt->sa, dev->dev_addr, ETH_ALEN); + /* BSSID is left zeroed, wildcard value */ + mgmt->u.action.category = MESH_PATH_SEL_CATEGORY; + mgmt->u.action.u.mesh_action.action_code = MPATH_PERR; + ie_len = 12; + pos = skb_put(skb, 2 + ie_len); + *pos++ = WLAN_EID_PERR; + *pos++ = ie_len; + /* mode flags, reserved */ + *pos++ = 0; + /* number of destinations */ + *pos++ = 1; + memcpy(pos, dst, ETH_ALEN); + pos += ETH_ALEN; + memcpy(pos, &dst_dsn, 4); + + ieee80211_sta_tx(dev, skb, 0); + return 0; +} + +static u32 airtime_link_metric_get(struct ieee80211_local *local, + struct sta_info *sta) +{ + struct ieee80211_supported_band *sband; + /* This should be adjusted for each device */ + int device_constant = 1 << ARITH_SHIFT; + int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT; + int s_unit = 1 << ARITH_SHIFT; + int rate, err; + u32 tx_time, estimated_retx; + u64 result; + + sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; + + if (sta->fail_avg >= 100) + return MAX_METRIC; + err = (sta->fail_avg << ARITH_SHIFT) / 100; + + /* bitrate is in units of 100 Kbps, while we need rate in units of + * 1Mbps. This will be corrected on tx_time computation. + */ + rate = sband->bitrates[sta->txrate_idx].bitrate; + tx_time = (device_constant + 10 * test_frame_len / rate); + estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); + result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ; + return (u32)result; +} + +/** + * hwmp_route_info_get - Update routing info to originator and transmitter + * + * @dev: local mesh interface + * @mgmt: mesh management frame + * @hwmp_ie: hwmp information element (PREP or PREQ) + * + * This function updates the path routing information to the originator and the + * transmitter of a HWMP PREQ or PREP fram. + * + * Returns: metric to frame originator or 0 if the frame should not be further + * processed + * + * Notes: this function is the only place (besides user-provided info) where + * path routing information is updated. + */ +static u32 hwmp_route_info_get(struct net_device *dev, + struct ieee80211_mgmt *mgmt, + u8 *hwmp_ie) +{ + struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr); + struct mesh_path *mpath; + struct sta_info *sta; + bool fresh_info; + u8 *orig_addr, *ta; + u32 orig_dsn, orig_metric; + unsigned long orig_lifetime, exp_time; + u32 last_hop_metric, new_metric; + bool process = true; + u8 action = mgmt->u.action.u.mesh_action.action_code; + + rcu_read_lock(); + sta = sta_info_get(local, mgmt->sa); + if (!sta) + return 0; + + last_hop_metric = airtime_link_metric_get(local, sta); + /* Update and check originator routing info */ + fresh_info = true; + + switch (action) { + case MPATH_PREQ: + orig_addr = PREQ_IE_ORIG_ADDR(hwmp_ie); + orig_dsn = PREQ_IE_ORIG_DSN(hwmp_ie); + orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie); + orig_metric = PREQ_IE_METRIC(hwmp_ie); + break; + case MPATH_PREP: + /* Originator here refers to the MP that was the destination in + * the Path Request. The draft refers to that MP as the + * destination address, even though usually it is the origin of + * the PREP frame. We divert from the nomenclature in the draft + * so that we can easily use a single function to gather path + * information from both PREQ and PREP frames. + */ + orig_addr = PREP_IE_ORIG_ADDR(hwmp_ie); + orig_dsn = PREP_IE_ORIG_DSN(hwmp_ie); + orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); + orig_metric = PREP_IE_METRIC(hwmp_ie); + break; + default: + sta_info_put(sta); + return 0; + } + new_metric = orig_metric + last_hop_metric; + if (new_metric < orig_metric) + new_metric = MAX_METRIC; + exp_time = TU_TO_EXP_TIME(orig_lifetime); + + if (memcmp(orig_addr, dev->dev_addr, ETH_ALEN) == 0) { + /* This MP is the originator, we are not interested in this + * frame, except for updating transmitter's path info. + */ + process = false; + fresh_info = false; + } else { + mpath = mesh_path_lookup(orig_addr, dev); + if (mpath) { + spin_lock_bh(&mpath->state_lock); + if (mpath->flags & MESH_PATH_FIXED) + fresh_info = false; + else if ((mpath->flags & MESH_PATH_ACTIVE) && + (mpath->flags & MESH_PATH_DSN_VALID)) { + if (DSN_GT(mpath->dsn, orig_dsn) || + (mpath->dsn == orig_dsn && + action == MPATH_PREQ && + new_metric > mpath->metric)) { + process = false; + fresh_info = false; + } + } + } else { + mesh_path_add(orig_addr, dev); + mpath = mesh_path_lookup(orig_addr, dev); + if (!mpath) { + rcu_read_unlock(); + sta_info_put(sta); + return 0; + } + spin_lock_bh(&mpath->state_lock); + } + + if (fresh_info) { + mesh_path_assign_nexthop(mpath, sta); + mpath->flags |= MESH_PATH_DSN_VALID; + mpath->metric = new_metric; + mpath->dsn = orig_dsn; + mpath->exp_time = time_after(mpath->exp_time, exp_time) + ? mpath->exp_time : exp_time; + mesh_path_activate(mpath); + spin_unlock_bh(&mpath->state_lock); + mesh_path_tx_pending(mpath); + /* draft says preq_id should be saved to, but there does + * not seem to be any use for it, skipping by now + */ + } else + spin_unlock_bh(&mpath->state_lock); + } + + /* Update and check transmitter routing info */ + ta = mgmt->sa; + if (memcmp(orig_addr, ta, ETH_ALEN) == 0) + fresh_info = false; + else { + fresh_info = true; + + mpath = mesh_path_lookup(ta, dev); + if (mpath) { + spin_lock_bh(&mpath->state_lock); + if ((mpath->flags & MESH_PATH_FIXED) || + ((mpath->flags & MESH_PATH_ACTIVE) && + (last_hop_metric > mpath->metric))) + fresh_info = false; + } else { + mesh_path_add(ta, dev); + mpath = mesh_path_lookup(ta, dev); + if (!mpath) { + rcu_read_unlock(); + sta_info_put(sta); + return 0; + } + spin_lock_bh(&mpath->state_lock); + } + + if (fresh_info) { + mesh_path_assign_nexthop(mpath, sta); + mpath->flags &= ~MESH_PATH_DSN_VALID; + mpath->metric = last_hop_metric; + mpath->exp_time = time_after(mpath->exp_time, exp_time) + ? mpath->exp_time : exp_time; + mesh_path_activate(mpath); + spin_unlock_bh(&mpath->state_lock); + mesh_path_tx_pending(mpath); + } else + spin_unlock_bh(&mpath->state_lock); + } + + sta_info_put(sta); + rcu_read_unlock(); + + return process ? new_metric : 0; +} + +static void hwmp_preq_frame_process(struct net_device *dev, + struct ieee80211_mgmt *mgmt, + u8 *preq_elem, u32 metric) { + struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); + struct ieee80211_if_sta *ifsta = &sdata->u.sta; + struct mesh_path *mpath; + u8 *dst_addr, *orig_addr; + u8 dst_flags, ttl; + u32 orig_dsn, dst_dsn, lifetime; + bool reply = false; + bool forward = true; + + /* Update destination DSN, if present */ + dst_addr = PREQ_IE_DST_ADDR(preq_elem); + orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); + dst_dsn = PREQ_IE_DST_DSN(preq_elem); + orig_dsn = PREQ_IE_ORIG_DSN(preq_elem); + dst_flags = PREQ_IE_DST_F(preq_elem); + + if (memcmp(dst_addr, dev->dev_addr, ETH_ALEN) == 0) { + forward = false; + reply = true; + metric = 0; + if (time_after(jiffies, ifsta->last_dsn_update + + net_traversal_jiffies(sdata)) || + time_before(jiffies, ifsta->last_dsn_update)) { + dst_dsn = ++ifsta->dsn; + ifsta->last_dsn_update = jiffies; + } + } else { + rcu_read_lock(); + mpath = mesh_path_lookup(dst_addr, dev); + if (mpath) { + if ((!(mpath->flags & MESH_PATH_DSN_VALID)) || + DSN_LT(mpath->dsn, dst_dsn)) { + mpath->dsn = dst_dsn; + mpath->flags &= MESH_PATH_DSN_VALID; + } else if ((!(dst_flags & MP_F_DO)) && + (mpath->flags & MESH_PATH_ACTIVE)) { + reply = true; + metric = mpath->metric; + dst_dsn = mpath->dsn; + if (dst_flags & MP_F_RF) + dst_flags |= MP_F_DO; + else + forward = false; + } + } + rcu_read_unlock(); + } + + if (reply) { + lifetime = PREQ_IE_LIFETIME(preq_elem); + ttl = ifsta->mshcfg.dot11MeshTTL; + if (ttl != 0) + mesh_path_sel_frame_tx(MPATH_PREP, 0, dst_addr, + __cpu_to_le32(dst_dsn), 0, orig_addr, + __cpu_to_le32(orig_dsn), mgmt->sa, 0, ttl, + __cpu_to_le32(lifetime), __cpu_to_le32(metric), + 0, dev); + else + ifsta->mshstats.dropped_frames_ttl++; + } + + if (forward) { + u32 preq_id; + u8 hopcount, flags; + + ttl = PREQ_IE_TTL(preq_elem); + lifetime = PREQ_IE_LIFETIME(preq_elem); + if (ttl <= 1) { + ifsta->mshstats.dropped_frames_ttl++; + return; + } + --ttl; + flags = PREQ_IE_FLAGS(preq_elem); + preq_id = PREQ_IE_PREQ_ID(preq_elem); + hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; + mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, + __cpu_to_le32(orig_dsn), dst_flags, dst_addr, + __cpu_to_le32(dst_dsn), dev->broadcast, + hopcount, ttl, __cpu_to_le32(lifetime), + __cpu_to_le32(metric), __cpu_to_le32(preq_id), + dev); + ifsta->mshstats.fwded_frames++; + } +} + + +static void hwmp_prep_frame_process(struct net_device *dev, + struct ieee80211_mgmt *mgmt, + u8 *prep_elem, u32 metric) +{ + struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); + struct mesh_path *mpath; + u8 *dst_addr, *orig_addr; + u8 ttl, hopcount, flags; + u8 next_hop[ETH_ALEN]; + u32 dst_dsn, orig_dsn, lifetime; + + /* Note that we divert from the draft nomenclature and denominate + * destination to what the draft refers to as origininator. So in this + * function destnation refers to the final destination of the PREP, + * which corresponds with the originator of the PREQ which this PREP + * replies + */ + dst_addr = PREP_IE_DST_ADDR(prep_elem); + if (memcmp(dst_addr, dev->dev_addr, ETH_ALEN) == 0) + /* destination, no forwarding required */ + return; + + ttl = PREP_IE_TTL(prep_elem); + if (ttl <= 1) { + sdata->u.sta.mshstats.dropped_frames_ttl++; + return; + } + + rcu_read_lock(); + mpath = mesh_path_lookup(dst_addr, dev); + if (mpath) + spin_lock_bh(&mpath->state_lock); + else + goto fail; + if (!(mpath->flags & MESH_PATH_ACTIVE)) { + spin_unlock_bh(&mpath->state_lock); + goto fail; + } + memcpy(next_hop, mpath->next_hop->addr, ETH_ALEN); + spin_unlock_bh(&mpath->state_lock); + --ttl; + flags = PREP_IE_FLAGS(prep_elem); + lifetime = PREP_IE_LIFETIME(prep_elem); + hopcount = PREP_IE_HOPCOUNT(prep_elem) + 1; + orig_addr = PREP_IE_ORIG_ADDR(prep_elem); + dst_dsn = PREP_IE_DST_DSN(prep_elem); + orig_dsn = PREP_IE_ORIG_DSN(prep_elem); + + mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, + __cpu_to_le32(orig_dsn), 0, dst_addr, + __cpu_to_le32(dst_dsn), mpath->next_hop->addr, hopcount, ttl, + __cpu_to_le32(lifetime), __cpu_to_le32(metric), + 0, dev); + rcu_read_unlock(); + sdata->u.sta.mshstats.fwded_frames++; + return; + +fail: + rcu_read_unlock(); + sdata->u.sta.mshstats.dropped_frames_no_route++; + return; +} + +static void hwmp_perr_frame_process(struct net_device *dev, + struct ieee80211_mgmt *mgmt, u8 *perr_elem) +{ + struct mesh_path *mpath; + u8 *ta, *dst_addr; + u32 dst_dsn; + + ta = mgmt->sa; + dst_addr = PERR_IE_DST_ADDR(perr_elem); + dst_dsn = PERR_IE_DST_DSN(perr_elem); + rcu_read_lock(); + mpath = mesh_path_lookup(dst_addr, dev); + if (mpath) { + spin_lock_bh(&mpath->state_lock); + if (mpath->flags & MESH_PATH_ACTIVE && + memcmp(ta, mpath->next_hop->addr, ETH_ALEN) == 0 && + (!(mpath->flags & MESH_PATH_DSN_VALID) || + DSN_GT(dst_dsn, mpath->dsn))) { + mpath->flags &= ~MESH_PATH_ACTIVE; + mpath->dsn = dst_dsn; + spin_unlock_bh(&mpath->state_lock); + mesh_path_error_tx(dst_addr, dst_dsn, dev->broadcast, + dev); + } else + spin_unlock_bh(&mpath->state_lock); + } + rcu_read_unlock(); +} + + + +void mesh_rx_path_sel_frame(struct net_device *dev, + struct ieee80211_mgmt *mgmt, + size_t len) +{ + struct ieee802_11_elems elems; + size_t baselen; + u32 last_hop_metric; + + baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; + ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, + len - baselen, &elems); + + switch (mgmt->u.action.u.mesh_action.action_code) { + case MPATH_PREQ: + if (!elems.preq || elems.preq_len != 37) + /* Right now we support just 1 destination and no AE */ + return; + last_hop_metric = hwmp_route_info_get(dev, mgmt, elems.preq); + if (!last_hop_metric) + return; + hwmp_preq_frame_process(dev, mgmt, elems.preq, last_hop_metric); + break; + case MPATH_PREP: + if (!elems.prep || elems.prep_len != 31) + /* Right now we support no AE */ + return; + last_hop_metric = hwmp_route_info_get(dev, mgmt, elems.prep); + if (!last_hop_metric) + return; + hwmp_prep_frame_process(dev, mgmt, elems.prep, last_hop_metric); + break; + case MPATH_PERR: + if (!elems.perr || elems.perr_len != 12) + /* Right now we support only one destination per PERR */ + return; + hwmp_perr_frame_process(dev, mgmt, elems.perr); + default: + return; + } + +} + +/** + * mesh_queue_preq - queue a PREQ to a given destination + * + * @mpath: mesh path to discover + * @flags: special attributes of the PREQ to be sent + * + * Locking: the function must be called from within a rcu read lock block. + * + */ +static void mesh_queue_preq(struct mesh_path *mpath, u8 flags) +{ + struct ieee80211_sub_if_data *sdata = + IEEE80211_DEV_TO_SUB_IF(mpath->dev); + struct ieee80211_if_sta *ifsta = &sdata->u.sta; + struct mesh_preq_queue *preq_node; + + preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_KERNEL); + if (!preq_node) { + printk(KERN_DEBUG "Mesh HWMP: could not allocate PREQ node\n"); + return; + } + + spin_lock(&ifsta->mesh_preq_queue_lock); + if (ifsta->preq_queue_len == MAX_PREQ_QUEUE_LEN) { + spin_unlock(&ifsta->mesh_preq_queue_lock); + kfree(preq_node); + if (printk_ratelimit()) + printk(KERN_DEBUG "Mesh HWMP: PREQ node queue full\n"); + return; + } + + memcpy(preq_node->dst, mpath->dst, ETH_ALEN); + preq_node->flags = flags; + + list_add_tail(&preq_node->list, &ifsta->preq_queue.list); + ++ifsta->preq_queue_len; + spin_unlock(&ifsta->mesh_preq_queue_lock); + + if (time_after(jiffies, ifsta->last_preq + min_preq_int_jiff(sdata))) + queue_work(sdata->local->hw.workqueue, &ifsta->work); + + else if (time_before(jiffies, ifsta->last_preq)) { + /* avoid long wait if did not send preqs for a long time + * and jiffies wrapped around + */ + ifsta->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; + queue_work(sdata->local->hw.workqueue, &ifsta->work); + } else + mod_timer(&ifsta->mesh_path_timer, ifsta->last_preq + + min_preq_int_jiff(sdata)); +} + +/** + * mesh_path_start_discovery - launch a path discovery from the PREQ queue + * + * @dev: local mesh interface + */ +void mesh_path_start_discovery(struct net_device *dev) +{ + struct ieee80211_sub_if_data *sdata = + IEEE80211_DEV_TO_SUB_IF(dev); + struct ieee80211_if_sta *ifsta = &sdata->u.sta; + struct mesh_preq_queue *preq_node; + struct mesh_path *mpath; + u8 ttl, dst_flags; + u32 lifetime; + + spin_lock(&ifsta->mesh_preq_queue_lock); + if (!ifsta->preq_queue_len || + time_before(jiffies, ifsta->last_preq + + min_preq_int_jiff(sdata))) { + spin_unlock(&ifsta->mesh_preq_queue_lock); + return; + } + + preq_node = list_first_entry(&ifsta->preq_queue.list, + struct mesh_preq_queue, list); + list_del(&preq_node->list); + --ifsta->preq_queue_len; + spin_unlock(&ifsta->mesh_preq_queue_lock); + + rcu_read_lock(); + mpath = mesh_path_lookup(preq_node->dst, dev); + if (!mpath) + goto enddiscovery; + + spin_lock_bh(&mpath->state_lock); + if (preq_node->flags & PREQ_Q_F_START) { + if (mpath->flags & MESH_PATH_RESOLVING) { + spin_unlock_bh(&mpath->state_lock); + goto enddiscovery; + } else { + mpath->flags &= ~MESH_PATH_RESOLVED; + mpath->flags |= MESH_PATH_RESOLVING; + mpath->discovery_retries = 0; + mpath->discovery_timeout = disc_timeout_jiff(sdata); + } + } else if (!(mpath->flags & MESH_PATH_RESOLVING) || + mpath->flags & MESH_PATH_RESOLVED) { + mpath->flags &= ~MESH_PATH_RESOLVING; + spin_unlock_bh(&mpath->state_lock); + goto enddiscovery; + } + + ifsta->last_preq = jiffies; + + if (time_after(jiffies, ifsta->last_dsn_update + + net_traversal_jiffies(sdata)) || + time_before(jiffies, ifsta->last_dsn_update)) { + ++ifsta->dsn; + sdata->u.sta.last_dsn_update = jiffies; + } + lifetime = default_lifetime(sdata); + ttl = sdata->u.sta.mshcfg.dot11MeshTTL; + if (ttl == 0) { + sdata->u.sta.mshstats.dropped_frames_ttl++; + spin_unlock_bh(&mpath->state_lock); + goto enddiscovery; + } + + if (preq_node->flags & PREQ_Q_F_REFRESH) + dst_flags = MP_F_DO; + else + dst_flags = MP_F_RF; + + spin_unlock_bh(&mpath->state_lock); + mesh_path_sel_frame_tx(MPATH_PREQ, 0, dev->dev_addr, + __cpu_to_le32(ifsta->dsn), dst_flags, mpath->dst, + __cpu_to_le32(mpath->dsn), dev->broadcast, 0, + ttl, __cpu_to_le32(lifetime), 0, + __cpu_to_le32(ifsta->preq_id++), dev); + mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); + +enddiscovery: + rcu_read_unlock(); + kfree(preq_node); +} + +/** + * ieee80211s_lookup_nexthop - put the appropriate next hop on a mesh frame + * + * @next_hop: output argument for next hop address + * @skb: frame to be sent + * @dev: network device the frame will be sent through + * + * Returns: 0 if the next hop was found. Nonzero otherwise. If no next hop is + * found, the function will start a path discovery and queue the frame so it is + * sent when the path is resolved. This means the caller must not free the skb + * in this case. + */ +int mesh_nexthop_lookup(u8 *next_hop, struct sk_buff *skb, + struct net_device *dev) +{ + struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); + struct sk_buff *skb_to_free = NULL; + struct mesh_path *mpath; + int err = 0; + + rcu_read_lock(); + mpath = mesh_path_lookup(skb->data, dev); + + if (!mpath) { + mesh_path_add(skb->data, dev); + mpath = mesh_path_lookup(skb->data, dev); + if (!mpath) { + dev_kfree_skb(skb); + sdata->u.sta.mshstats.dropped_frames_no_route++; + err = -ENOSPC; + goto endlookup; + } + } + + if (mpath->flags & MESH_PATH_ACTIVE) { + if (time_after(jiffies, mpath->exp_time - + msecs_to_jiffies(sdata->u.sta.mshcfg.path_refresh_time)) + && skb->pkt_type != PACKET_OTHERHOST + && !(mpath->flags & MESH_PATH_RESOLVING) + && !(mpath->flags & MESH_PATH_FIXED)) { + mesh_queue_preq(mpath, + PREQ_Q_F_START | PREQ_Q_F_REFRESH); + } + memcpy(next_hop, mpath->next_hop->addr, + ETH_ALEN); + } else { + if (!(mpath->flags & MESH_PATH_RESOLVING)) { + /* Start discovery only if it is not running yet */ + mesh_queue_preq(mpath, PREQ_Q_F_START); + } + + if (skb_queue_len(&mpath->frame_queue) >= + MESH_FRAME_QUEUE_LEN) { + skb_to_free = mpath->frame_queue.next; + skb_unlink(skb_to_free, &mpath->frame_queue); + } + + skb_queue_tail(&mpath->frame_queue, skb); + if (skb_to_free) + mesh_path_discard_frame(skb_to_free, dev); + err = -ENOENT; + } + +endlookup: + rcu_read_unlock(); + return err; +} + +void mesh_path_timer(unsigned long data) +{ + struct ieee80211_sub_if_data *sdata; + struct mesh_path *mpath; + bool delete = false; + + rcu_read_lock(); + mpath = (struct mesh_path *) data; + mpath = rcu_dereference(mpath); + if (!mpath) + goto endmpathtimer; + spin_lock_bh(&mpath->state_lock); + sdata = IEEE80211_DEV_TO_SUB_IF(mpath->dev); + if (mpath->flags & MESH_PATH_DELETE) { + mpath->flags = 0; + delete = true; + } else if (mpath->flags & MESH_PATH_RESOLVED || + (!(mpath->flags & MESH_PATH_RESOLVING))) + mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); + else if (mpath->discovery_retries < max_preq_retries(sdata)) { + ++mpath->discovery_retries; + mpath->discovery_timeout *= 2; + mesh_queue_preq(mpath, 0); + } else { + mpath->flags = 0; + mpath->exp_time = jiffies; + mesh_path_flush_pending(mpath); + } + + spin_unlock_bh(&mpath->state_lock); +endmpathtimer: + rcu_read_unlock(); + if (delete) + mesh_path_del(mpath->dst, mpath->dev); +} |