diff options
Diffstat (limited to 'net/mac80211/mesh_hwmp.c')
| -rw-r--r-- | net/mac80211/mesh_hwmp.c | 1280 |
1 files changed, 1280 insertions, 0 deletions
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c new file mode 100644 index 000000000..18158855d --- /dev/null +++ b/net/mac80211/mesh_hwmp.c @@ -0,0 +1,1280 @@ +/* + * Copyright (c) 2008, 2009 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 <linux/slab.h> +#include <linux/etherdevice.h> +#include <asm/unaligned.h> +#include "wme.h" +#include "mesh.h" + +#define TEST_FRAME_LEN 8192 +#define MAX_METRIC 0xffffffff +#define ARITH_SHIFT 8 +#define LINK_FAIL_THRESH 95 + +#define MAX_PREQ_QUEUE_LEN 64 + +static void mesh_queue_preq(struct mesh_path *, u8); + +static inline u32 u32_field_get(const u8 *preq_elem, int offset, bool ae) +{ + if (ae) + offset += 6; + return get_unaligned_le32(preq_elem + offset); +} + +static inline u16 u16_field_get(const 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) +#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) u32_field_get(x, 3, 0) +#define PREQ_IE_ORIG_ADDR(x) (x + 7) +#define PREQ_IE_ORIG_SN(x) u32_field_get(x, 13, 0) +#define PREQ_IE_LIFETIME(x) u32_field_get(x, 17, AE_F_SET(x)) +#define PREQ_IE_METRIC(x) u32_field_get(x, 21, AE_F_SET(x)) +#define PREQ_IE_TARGET_F(x) (*(AE_F_SET(x) ? x + 32 : x + 26)) +#define PREQ_IE_TARGET_ADDR(x) (AE_F_SET(x) ? x + 33 : x + 27) +#define PREQ_IE_TARGET_SN(x) u32_field_get(x, 33, AE_F_SET(x)) + + +#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) (AE_F_SET(x) ? x + 27 : x + 21) +#define PREP_IE_ORIG_SN(x) u32_field_get(x, 27, AE_F_SET(x)) +#define PREP_IE_LIFETIME(x) u32_field_get(x, 13, AE_F_SET(x)) +#define PREP_IE_METRIC(x) u32_field_get(x, 17, AE_F_SET(x)) +#define PREP_IE_TARGET_ADDR(x) (x + 3) +#define PREP_IE_TARGET_SN(x) u32_field_get(x, 9, 0) + +#define PERR_IE_TTL(x) (*(x)) +#define PERR_IE_TARGET_FLAGS(x) (*(x + 2)) +#define PERR_IE_TARGET_ADDR(x) (x + 3) +#define PERR_IE_TARGET_SN(x) u32_field_get(x, 9, 0) +#define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0) + +#define MSEC_TO_TU(x) (x*1000/1024) +#define SN_GT(x, y) ((s32)(y - x) < 0) +#define SN_LT(x, y) ((s32)(x - y) < 0) +#define MAX_SANE_SN_DELTA 32 + +static inline u32 SN_DELTA(u32 x, u32 y) +{ + return x >= y ? x - y : y - x; +} + +#define net_traversal_jiffies(s) \ + msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime) +#define default_lifetime(s) \ + MSEC_TO_TU(s->u.mesh.mshcfg.dot11MeshHWMPactivePathTimeout) +#define min_preq_int_jiff(s) \ + (msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPpreqMinInterval)) +#define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries) +#define disc_timeout_jiff(s) \ + msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout) +#define root_path_confirmation_jiffies(s) \ + msecs_to_jiffies(sdata->u.mesh.mshcfg.dot11MeshHWMPconfirmationInterval) + +enum mpath_frame_type { + MPATH_PREQ = 0, + MPATH_PREP, + MPATH_PERR, + MPATH_RANN +}; + +static const u8 broadcast_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; + +static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags, + const u8 *orig_addr, u32 orig_sn, + u8 target_flags, const u8 *target, + u32 target_sn, const u8 *da, + u8 hop_count, u8 ttl, + u32 lifetime, u32 metric, u32 preq_id, + struct ieee80211_sub_if_data *sdata) +{ + struct ieee80211_local *local = sdata->local; + struct sk_buff *skb; + struct ieee80211_mgmt *mgmt; + u8 *pos, ie_len; + int hdr_len = offsetofend(struct ieee80211_mgmt, + u.action.u.mesh_action); + + skb = dev_alloc_skb(local->tx_headroom + + hdr_len + + 2 + 37); /* max HWMP IE */ + if (!skb) + return -1; + skb_reserve(skb, local->tx_headroom); + mgmt = skb_put_zero(skb, hdr_len); + mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | + IEEE80211_STYPE_ACTION); + + memcpy(mgmt->da, da, ETH_ALEN); + memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); + /* BSSID == SA */ + memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); + mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION; + mgmt->u.action.u.mesh_action.action_code = + WLAN_MESH_ACTION_HWMP_PATH_SELECTION; + + switch (action) { + case MPATH_PREQ: + mhwmp_dbg(sdata, "sending PREQ to %pM\n", target); + ie_len = 37; + pos = skb_put(skb, 2 + ie_len); + *pos++ = WLAN_EID_PREQ; + break; + case MPATH_PREP: + mhwmp_dbg(sdata, "sending PREP to %pM\n", orig_addr); + ie_len = 31; + pos = skb_put(skb, 2 + ie_len); + *pos++ = WLAN_EID_PREP; + break; + case MPATH_RANN: + mhwmp_dbg(sdata, "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; + } + *pos++ = ie_len; + *pos++ = flags; + *pos++ = hop_count; + *pos++ = ttl; + if (action == MPATH_PREP) { + memcpy(pos, target, ETH_ALEN); + pos += ETH_ALEN; + put_unaligned_le32(target_sn, pos); + pos += 4; + } else { + if (action == MPATH_PREQ) { + put_unaligned_le32(preq_id, pos); + pos += 4; + } + memcpy(pos, orig_addr, ETH_ALEN); + pos += ETH_ALEN; + put_unaligned_le32(orig_sn, pos); + pos += 4; + } + put_unaligned_le32(lifetime, pos); /* interval for RANN */ + pos += 4; + put_unaligned_le32(metric, pos); + pos += 4; + if (action == MPATH_PREQ) { + *pos++ = 1; /* destination count */ + *pos++ = target_flags; + memcpy(pos, target, ETH_ALEN); + pos += ETH_ALEN; + put_unaligned_le32(target_sn, pos); + pos += 4; + } else if (action == MPATH_PREP) { + memcpy(pos, orig_addr, ETH_ALEN); + pos += ETH_ALEN; + put_unaligned_le32(orig_sn, pos); + pos += 4; + } + + ieee80211_tx_skb(sdata, skb); + return 0; +} + + +/* Headroom is not adjusted. Caller should ensure that skb has sufficient + * headroom in case the frame is encrypted. */ +static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata, + struct sk_buff *skb) +{ + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; + + skb_reset_mac_header(skb); + skb_reset_network_header(skb); + skb_reset_transport_header(skb); + + /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */ + skb_set_queue_mapping(skb, IEEE80211_AC_VO); + skb->priority = 7; + + info->control.vif = &sdata->vif; + info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; + ieee80211_set_qos_hdr(sdata, skb); + ieee80211_mps_set_frame_flags(sdata, NULL, hdr); +} + +/** + * mesh_path_error_tx - Sends a PERR mesh management frame + * + * @ttl: allowed remaining hops + * @target: broken destination + * @target_sn: SN of the broken destination + * @target_rcode: reason code for this PERR + * @ra: node this frame is addressed to + * @sdata: local mesh subif + * + * Note: This function may be called with driver locks taken that the driver + * also acquires in the TX path. To avoid a deadlock we don't transmit the + * frame directly but add it to the pending queue instead. + */ +int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata, + u8 ttl, const u8 *target, u32 target_sn, + u16 target_rcode, const u8 *ra) +{ + struct ieee80211_local *local = sdata->local; + struct sk_buff *skb; + struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; + struct ieee80211_mgmt *mgmt; + u8 *pos, ie_len; + int hdr_len = offsetofend(struct ieee80211_mgmt, + u.action.u.mesh_action); + + if (time_before(jiffies, ifmsh->next_perr)) + return -EAGAIN; + + skb = dev_alloc_skb(local->tx_headroom + + sdata->encrypt_headroom + + IEEE80211_ENCRYPT_TAILROOM + + hdr_len + + 2 + 15 /* PERR IE */); + if (!skb) + return -1; + skb_reserve(skb, local->tx_headroom + sdata->encrypt_headroom); + mgmt = skb_put_zero(skb, hdr_len); + mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | + IEEE80211_STYPE_ACTION); + + memcpy(mgmt->da, ra, ETH_ALEN); + memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); + /* BSSID == SA */ + memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); + mgmt->u.action.category = WLAN_CATEGORY_MESH_ACTION; + mgmt->u.action.u.mesh_action.action_code = + WLAN_MESH_ACTION_HWMP_PATH_SELECTION; + ie_len = 15; + pos = skb_put(skb, 2 + ie_len); + *pos++ = WLAN_EID_PERR; + *pos++ = ie_len; + /* ttl */ + *pos++ = ttl; + /* number of destinations */ + *pos++ = 1; + /* Flags field has AE bit only as defined in + * sec 8.4.2.117 IEEE802.11-2012 + */ + *pos = 0; + pos++; + memcpy(pos, target, ETH_ALEN); + pos += ETH_ALEN; + put_unaligned_le32(target_sn, pos); + pos += 4; + put_unaligned_le16(target_rcode, pos); + + /* see note in function header */ + prepare_frame_for_deferred_tx(sdata, skb); + ifmsh->next_perr = TU_TO_EXP_TIME( + ifmsh->mshcfg.dot11MeshHWMPperrMinInterval); + ieee80211_add_pending_skb(local, skb); + return 0; +} + +void ieee80211s_update_metric(struct ieee80211_local *local, + struct sta_info *sta, + struct ieee80211_tx_status *st) +{ + struct ieee80211_tx_info *txinfo = st->info; + int failed; + + failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK); + + /* moving average, scaled to 100. + * feed failure as 100 and success as 0 + */ + ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, failed * 100); + if (ewma_mesh_fail_avg_read(&sta->mesh->fail_avg) > + LINK_FAIL_THRESH) + mesh_plink_broken(sta); +} + +static u32 airtime_link_metric_get(struct ieee80211_local *local, + struct sta_info *sta) +{ + struct rate_info rinfo; + /* 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; + unsigned long fail_avg = + ewma_mesh_fail_avg_read(&sta->mesh->fail_avg); + + if (sta->mesh->plink_state != NL80211_PLINK_ESTAB) + return MAX_METRIC; + + /* Try to get rate based on HW/SW RC algorithm. + * Rate is returned in units of Kbps, correct this + * to comply with airtime calculation units + * Round up in case we get rate < 100Kbps + */ + rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100); + + if (rate) { + err = 0; + } else { + if (fail_avg > LINK_FAIL_THRESH) + return MAX_METRIC; + + sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo); + rate = cfg80211_calculate_bitrate(&rinfo); + if (WARN_ON(!rate)) + return MAX_METRIC; + + err = (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. + */ + tx_time = (device_constant + 10 * test_frame_len / rate); + estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); + result = ((u64)tx_time * estimated_retx) >> (2 * ARITH_SHIFT); + return (u32)result; +} + +/** + * hwmp_route_info_get - Update routing info to originator and transmitter + * + * @sdata: local mesh subif + * @mgmt: mesh management frame + * @hwmp_ie: hwmp information element (PREP or PREQ) + * @action: type of hwmp ie + * + * This function updates the path routing information to the originator and the + * transmitter of a HWMP PREQ or PREP frame. + * + * 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 ieee80211_sub_if_data *sdata, + struct ieee80211_mgmt *mgmt, + const u8 *hwmp_ie, enum mpath_frame_type action) +{ + struct ieee80211_local *local = sdata->local; + struct mesh_path *mpath; + struct sta_info *sta; + bool fresh_info; + const u8 *orig_addr, *ta; + u32 orig_sn, orig_metric; + unsigned long orig_lifetime, exp_time; + u32 last_hop_metric, new_metric; + bool process = true; + + rcu_read_lock(); + sta = sta_info_get(sdata, mgmt->sa); + if (!sta) { + rcu_read_unlock(); + 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_sn = PREQ_IE_ORIG_SN(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 target in the + * Path Request. 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_TARGET_ADDR(hwmp_ie); + orig_sn = PREP_IE_TARGET_SN(hwmp_ie); + orig_lifetime = PREP_IE_LIFETIME(hwmp_ie); + orig_metric = PREP_IE_METRIC(hwmp_ie); + break; + default: + rcu_read_unlock(); + 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 (ether_addr_equal(orig_addr, sdata->vif.addr)) { + /* 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(sdata, orig_addr); + 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_SN_VALID)) { + if (SN_GT(mpath->sn, orig_sn) || + (mpath->sn == orig_sn && + new_metric >= mpath->metric)) { + process = false; + fresh_info = false; + } + } else if (!(mpath->flags & MESH_PATH_ACTIVE)) { + bool have_sn, newer_sn, bounced; + + have_sn = mpath->flags & MESH_PATH_SN_VALID; + newer_sn = have_sn && SN_GT(orig_sn, mpath->sn); + bounced = have_sn && + (SN_DELTA(orig_sn, mpath->sn) > + MAX_SANE_SN_DELTA); + + if (!have_sn || newer_sn) { + /* if SN is newer than what we had + * then we can take it */; + } else if (bounced) { + /* if SN is way different than what + * we had then assume the other side + * rebooted or restarted */; + } else { + process = false; + fresh_info = false; + } + } + } else { + mpath = mesh_path_add(sdata, orig_addr); + if (IS_ERR(mpath)) { + rcu_read_unlock(); + return 0; + } + spin_lock_bh(&mpath->state_lock); + } + + if (fresh_info) { + mesh_path_assign_nexthop(mpath, sta); + mpath->flags |= MESH_PATH_SN_VALID; + mpath->metric = new_metric; + mpath->sn = orig_sn; + 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); + ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); + /* init it at a low value - 0 start is tricky */ + ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); + 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 (ether_addr_equal(orig_addr, ta)) + fresh_info = false; + else { + fresh_info = true; + + mpath = mesh_path_lookup(sdata, ta); + 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 { + mpath = mesh_path_add(sdata, ta); + if (IS_ERR(mpath)) { + rcu_read_unlock(); + return 0; + } + spin_lock_bh(&mpath->state_lock); + } + + if (fresh_info) { + mesh_path_assign_nexthop(mpath, sta); + 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); + ewma_mesh_fail_avg_init(&sta->mesh->fail_avg); + /* init it at a low value - 0 start is tricky */ + ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1); + mesh_path_tx_pending(mpath); + } else + spin_unlock_bh(&mpath->state_lock); + } + + rcu_read_unlock(); + + return process ? new_metric : 0; +} + +static void hwmp_preq_frame_process(struct ieee80211_sub_if_data *sdata, + struct ieee80211_mgmt *mgmt, + const u8 *preq_elem, u32 orig_metric) +{ + struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; + struct mesh_path *mpath = NULL; + const u8 *target_addr, *orig_addr; + const u8 *da; + u8 target_flags, ttl, flags; + u32 orig_sn, target_sn, lifetime, target_metric = 0; + bool reply = false; + bool forward = true; + bool root_is_gate; + + /* Update target SN, if present */ + target_addr = PREQ_IE_TARGET_ADDR(preq_elem); + orig_addr = PREQ_IE_ORIG_ADDR(preq_elem); + target_sn = PREQ_IE_TARGET_SN(preq_elem); + orig_sn = PREQ_IE_ORIG_SN(preq_elem); + target_flags = PREQ_IE_TARGET_F(preq_elem); + /* Proactive PREQ gate announcements */ + flags = PREQ_IE_FLAGS(preq_elem); + root_is_gate = !!(flags & RANN_FLAG_IS_GATE); + + mhwmp_dbg(sdata, "received PREQ from %pM\n", orig_addr); + + if (ether_addr_equal(target_addr, sdata->vif.addr)) { + mhwmp_dbg(sdata, "PREQ is for us\n"); + forward = false; + reply = true; + target_metric = 0; + + if (SN_GT(target_sn, ifmsh->sn)) + ifmsh->sn = target_sn; + + if (time_after(jiffies, ifmsh->last_sn_update + + net_traversal_jiffies(sdata)) || + time_before(jiffies, ifmsh->last_sn_update)) { + ++ifmsh->sn; + ifmsh->last_sn_update = jiffies; + } + target_sn = ifmsh->sn; + } else if (is_broadcast_ether_addr(target_addr) && + (target_flags & IEEE80211_PREQ_TO_FLAG)) { + rcu_read_lock(); + mpath = mesh_path_lookup(sdata, orig_addr); + if (mpath) { + if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { + reply = true; + target_addr = sdata->vif.addr; + target_sn = ++ifmsh->sn; + target_metric = 0; + ifmsh->last_sn_update = jiffies; + } + if (root_is_gate) + mesh_path_add_gate(mpath); + } + rcu_read_unlock(); + } else { + rcu_read_lock(); + mpath = mesh_path_lookup(sdata, target_addr); + if (mpath) { + if ((!(mpath->flags & MESH_PATH_SN_VALID)) || + SN_LT(mpath->sn, target_sn)) { + mpath->sn = target_sn; + mpath->flags |= MESH_PATH_SN_VALID; + } else if ((!(target_flags & IEEE80211_PREQ_TO_FLAG)) && + (mpath->flags & MESH_PATH_ACTIVE)) { + reply = true; + target_metric = mpath->metric; + target_sn = mpath->sn; + /* Case E2 of sec 13.10.9.3 IEEE 802.11-2012*/ + target_flags |= IEEE80211_PREQ_TO_FLAG; + } + } + rcu_read_unlock(); + } + + if (reply) { + lifetime = PREQ_IE_LIFETIME(preq_elem); + ttl = ifmsh->mshcfg.element_ttl; + if (ttl != 0) { + mhwmp_dbg(sdata, "replying to the PREQ\n"); + mesh_path_sel_frame_tx(MPATH_PREP, 0, orig_addr, + orig_sn, 0, target_addr, + target_sn, mgmt->sa, 0, ttl, + lifetime, target_metric, 0, + sdata); + } else { + ifmsh->mshstats.dropped_frames_ttl++; + } + } + + if (forward && ifmsh->mshcfg.dot11MeshForwarding) { + u32 preq_id; + u8 hopcount; + + ttl = PREQ_IE_TTL(preq_elem); + lifetime = PREQ_IE_LIFETIME(preq_elem); + if (ttl <= 1) { + ifmsh->mshstats.dropped_frames_ttl++; + return; + } + mhwmp_dbg(sdata, "forwarding the PREQ from %pM\n", orig_addr); + --ttl; + preq_id = PREQ_IE_PREQ_ID(preq_elem); + hopcount = PREQ_IE_HOPCOUNT(preq_elem) + 1; + da = (mpath && mpath->is_root) ? + mpath->rann_snd_addr : broadcast_addr; + + if (flags & IEEE80211_PREQ_PROACTIVE_PREP_FLAG) { + target_addr = PREQ_IE_TARGET_ADDR(preq_elem); + target_sn = PREQ_IE_TARGET_SN(preq_elem); + } + + mesh_path_sel_frame_tx(MPATH_PREQ, flags, orig_addr, + orig_sn, target_flags, target_addr, + target_sn, da, hopcount, ttl, lifetime, + orig_metric, preq_id, sdata); + if (!is_multicast_ether_addr(da)) + ifmsh->mshstats.fwded_unicast++; + else + ifmsh->mshstats.fwded_mcast++; + ifmsh->mshstats.fwded_frames++; + } +} + + +static inline struct sta_info * +next_hop_deref_protected(struct mesh_path *mpath) +{ + return rcu_dereference_protected(mpath->next_hop, + lockdep_is_held(&mpath->state_lock)); +} + + +static void hwmp_prep_frame_process(struct ieee80211_sub_if_data *sdata, + struct ieee80211_mgmt *mgmt, + const u8 *prep_elem, u32 metric) +{ + struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; + struct mesh_path *mpath; + const u8 *target_addr, *orig_addr; + u8 ttl, hopcount, flags; + u8 next_hop[ETH_ALEN]; + u32 target_sn, orig_sn, lifetime; + + mhwmp_dbg(sdata, "received PREP from %pM\n", + PREP_IE_TARGET_ADDR(prep_elem)); + + orig_addr = PREP_IE_ORIG_ADDR(prep_elem); + if (ether_addr_equal(orig_addr, sdata->vif.addr)) + /* destination, no forwarding required */ + return; + + if (!ifmsh->mshcfg.dot11MeshForwarding) + return; + + ttl = PREP_IE_TTL(prep_elem); + if (ttl <= 1) { + sdata->u.mesh.mshstats.dropped_frames_ttl++; + return; + } + + rcu_read_lock(); + mpath = mesh_path_lookup(sdata, orig_addr); + 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, next_hop_deref_protected(mpath)->sta.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; + target_addr = PREP_IE_TARGET_ADDR(prep_elem); + target_sn = PREP_IE_TARGET_SN(prep_elem); + orig_sn = PREP_IE_ORIG_SN(prep_elem); + + mesh_path_sel_frame_tx(MPATH_PREP, flags, orig_addr, orig_sn, 0, + target_addr, target_sn, next_hop, hopcount, + ttl, lifetime, metric, 0, sdata); + rcu_read_unlock(); + + sdata->u.mesh.mshstats.fwded_unicast++; + sdata->u.mesh.mshstats.fwded_frames++; + return; + +fail: + rcu_read_unlock(); + sdata->u.mesh.mshstats.dropped_frames_no_route++; +} + +static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata, + struct ieee80211_mgmt *mgmt, + const u8 *perr_elem) +{ + struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; + struct mesh_path *mpath; + u8 ttl; + const u8 *ta, *target_addr; + u32 target_sn; + u16 target_rcode; + + ta = mgmt->sa; + ttl = PERR_IE_TTL(perr_elem); + if (ttl <= 1) { + ifmsh->mshstats.dropped_frames_ttl++; + return; + } + ttl--; + target_addr = PERR_IE_TARGET_ADDR(perr_elem); + target_sn = PERR_IE_TARGET_SN(perr_elem); + target_rcode = PERR_IE_TARGET_RCODE(perr_elem); + + rcu_read_lock(); + mpath = mesh_path_lookup(sdata, target_addr); + if (mpath) { + struct sta_info *sta; + + spin_lock_bh(&mpath->state_lock); + sta = next_hop_deref_protected(mpath); + if (mpath->flags & MESH_PATH_ACTIVE && + ether_addr_equal(ta, sta->sta.addr) && + !(mpath->flags & MESH_PATH_FIXED) && + (!(mpath->flags & MESH_PATH_SN_VALID) || + SN_GT(target_sn, mpath->sn) || target_sn == 0)) { + mpath->flags &= ~MESH_PATH_ACTIVE; + if (target_sn != 0) + mpath->sn = target_sn; + else + mpath->sn += 1; + spin_unlock_bh(&mpath->state_lock); + if (!ifmsh->mshcfg.dot11MeshForwarding) + goto endperr; + mesh_path_error_tx(sdata, ttl, target_addr, + target_sn, target_rcode, + broadcast_addr); + } else + spin_unlock_bh(&mpath->state_lock); + } +endperr: + rcu_read_unlock(); +} + +static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, + struct ieee80211_mgmt *mgmt, + const struct ieee80211_rann_ie *rann) +{ + struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; + struct ieee80211_local *local = sdata->local; + struct sta_info *sta; + struct mesh_path *mpath; + u8 ttl, flags, hopcount; + const u8 *orig_addr; + u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval; + bool root_is_gate; + + ttl = rann->rann_ttl; + flags = rann->rann_flags; + root_is_gate = !!(flags & RANN_FLAG_IS_GATE); + orig_addr = rann->rann_addr; + orig_sn = le32_to_cpu(rann->rann_seq); + interval = le32_to_cpu(rann->rann_interval); + hopcount = rann->rann_hopcount; + hopcount++; + orig_metric = le32_to_cpu(rann->rann_metric); + + /* Ignore our own RANNs */ + if (ether_addr_equal(orig_addr, sdata->vif.addr)) + return; + + mhwmp_dbg(sdata, + "received RANN from %pM via neighbour %pM (is_gate=%d)\n", + orig_addr, mgmt->sa, root_is_gate); + + rcu_read_lock(); + sta = sta_info_get(sdata, mgmt->sa); + if (!sta) { + rcu_read_unlock(); + return; + } + + last_hop_metric = airtime_link_metric_get(local, sta); + new_metric = orig_metric + last_hop_metric; + if (new_metric < orig_metric) + new_metric = MAX_METRIC; + + mpath = mesh_path_lookup(sdata, orig_addr); + if (!mpath) { + mpath = mesh_path_add(sdata, orig_addr); + if (IS_ERR(mpath)) { + rcu_read_unlock(); + sdata->u.mesh.mshstats.dropped_frames_no_route++; + return; + } + } + + if (!(SN_LT(mpath->sn, orig_sn)) && + !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) { + rcu_read_unlock(); + return; + } + + if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) || + (time_after(jiffies, mpath->last_preq_to_root + + root_path_confirmation_jiffies(sdata)) || + time_before(jiffies, mpath->last_preq_to_root))) && + !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) { + mhwmp_dbg(sdata, + "time to refresh root mpath %pM\n", + orig_addr); + mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); + mpath->last_preq_to_root = jiffies; + } + + mpath->sn = orig_sn; + mpath->rann_metric = new_metric; + mpath->is_root = true; + /* Recording RANNs sender address to send individually + * addressed PREQs destined for root mesh STA */ + memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN); + + if (root_is_gate) + mesh_path_add_gate(mpath); + + if (ttl <= 1) { + ifmsh->mshstats.dropped_frames_ttl++; + rcu_read_unlock(); + return; + } + ttl--; + + if (ifmsh->mshcfg.dot11MeshForwarding) { + mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr, + orig_sn, 0, NULL, 0, broadcast_addr, + hopcount, ttl, interval, + new_metric, 0, sdata); + } + + rcu_read_unlock(); +} + + +void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, + struct ieee80211_mgmt *mgmt, size_t len) +{ + struct ieee802_11_elems elems; + size_t baselen; + u32 path_metric; + struct sta_info *sta; + + /* need action_code */ + if (len < IEEE80211_MIN_ACTION_SIZE + 1) + return; + + rcu_read_lock(); + sta = sta_info_get(sdata, mgmt->sa); + if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) { + rcu_read_unlock(); + return; + } + rcu_read_unlock(); + + baselen = (u8 *) mgmt->u.action.u.mesh_action.variable - (u8 *) mgmt; + ieee802_11_parse_elems(mgmt->u.action.u.mesh_action.variable, + len - baselen, false, &elems); + + if (elems.preq) { + if (elems.preq_len != 37) + /* Right now we support just 1 destination and no AE */ + return; + path_metric = hwmp_route_info_get(sdata, mgmt, elems.preq, + MPATH_PREQ); + if (path_metric) + hwmp_preq_frame_process(sdata, mgmt, elems.preq, + path_metric); + } + if (elems.prep) { + if (elems.prep_len != 31) + /* Right now we support no AE */ + return; + path_metric = hwmp_route_info_get(sdata, mgmt, elems.prep, + MPATH_PREP); + if (path_metric) + hwmp_prep_frame_process(sdata, mgmt, elems.prep, + path_metric); + } + if (elems.perr) { + if (elems.perr_len != 15) + /* Right now we support only one destination per PERR */ + return; + hwmp_perr_frame_process(sdata, mgmt, elems.perr); + } + if (elems.rann) + hwmp_rann_frame_process(sdata, mgmt, elems.rann); +} + +/** + * 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 = mpath->sdata; + struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; + struct mesh_preq_queue *preq_node; + + preq_node = kmalloc(sizeof(struct mesh_preq_queue), GFP_ATOMIC); + if (!preq_node) { + mhwmp_dbg(sdata, "could not allocate PREQ node\n"); + return; + } + + spin_lock_bh(&ifmsh->mesh_preq_queue_lock); + if (ifmsh->preq_queue_len == MAX_PREQ_QUEUE_LEN) { + spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); + kfree(preq_node); + if (printk_ratelimit()) + mhwmp_dbg(sdata, "PREQ node queue full\n"); + return; + } + + spin_lock(&mpath->state_lock); + if (mpath->flags & MESH_PATH_REQ_QUEUED) { + spin_unlock(&mpath->state_lock); + spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); + kfree(preq_node); + return; + } + + memcpy(preq_node->dst, mpath->dst, ETH_ALEN); + preq_node->flags = flags; + + mpath->flags |= MESH_PATH_REQ_QUEUED; + spin_unlock(&mpath->state_lock); + + list_add_tail(&preq_node->list, &ifmsh->preq_queue.list); + ++ifmsh->preq_queue_len; + spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); + + if (time_after(jiffies, ifmsh->last_preq + min_preq_int_jiff(sdata))) + ieee80211_queue_work(&sdata->local->hw, &sdata->work); + + else if (time_before(jiffies, ifmsh->last_preq)) { + /* avoid long wait if did not send preqs for a long time + * and jiffies wrapped around + */ + ifmsh->last_preq = jiffies - min_preq_int_jiff(sdata) - 1; + ieee80211_queue_work(&sdata->local->hw, &sdata->work); + } else + mod_timer(&ifmsh->mesh_path_timer, ifmsh->last_preq + + min_preq_int_jiff(sdata)); +} + +/** + * mesh_path_start_discovery - launch a path discovery from the PREQ queue + * + * @sdata: local mesh subif + */ +void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata) +{ + struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; + struct mesh_preq_queue *preq_node; + struct mesh_path *mpath; + u8 ttl, target_flags = 0; + const u8 *da; + u32 lifetime; + + spin_lock_bh(&ifmsh->mesh_preq_queue_lock); + if (!ifmsh->preq_queue_len || + time_before(jiffies, ifmsh->last_preq + + min_preq_int_jiff(sdata))) { + spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); + return; + } + + preq_node = list_first_entry(&ifmsh->preq_queue.list, + struct mesh_preq_queue, list); + list_del(&preq_node->list); + --ifmsh->preq_queue_len; + spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); + + rcu_read_lock(); + mpath = mesh_path_lookup(sdata, preq_node->dst); + if (!mpath) + goto enddiscovery; + + spin_lock_bh(&mpath->state_lock); + if (mpath->flags & (MESH_PATH_DELETED | MESH_PATH_FIXED)) { + spin_unlock_bh(&mpath->state_lock); + goto enddiscovery; + } + mpath->flags &= ~MESH_PATH_REQ_QUEUED; + 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; + } + + ifmsh->last_preq = jiffies; + + if (time_after(jiffies, ifmsh->last_sn_update + + net_traversal_jiffies(sdata)) || + time_before(jiffies, ifmsh->last_sn_update)) { + ++ifmsh->sn; + sdata->u.mesh.last_sn_update = jiffies; + } + lifetime = default_lifetime(sdata); + ttl = sdata->u.mesh.mshcfg.element_ttl; + if (ttl == 0) { + sdata->u.mesh.mshstats.dropped_frames_ttl++; + spin_unlock_bh(&mpath->state_lock); + goto enddiscovery; + } + + if (preq_node->flags & PREQ_Q_F_REFRESH) + target_flags |= IEEE80211_PREQ_TO_FLAG; + else + target_flags &= ~IEEE80211_PREQ_TO_FLAG; + + spin_unlock_bh(&mpath->state_lock); + da = (mpath->is_root) ? mpath->rann_snd_addr : broadcast_addr; + mesh_path_sel_frame_tx(MPATH_PREQ, 0, sdata->vif.addr, ifmsh->sn, + target_flags, mpath->dst, mpath->sn, da, 0, + ttl, lifetime, 0, ifmsh->preq_id++, sdata); + + spin_lock_bh(&mpath->state_lock); + if (mpath->flags & MESH_PATH_DELETED) { + spin_unlock_bh(&mpath->state_lock); + goto enddiscovery; + } + mod_timer(&mpath->timer, jiffies + mpath->discovery_timeout); + spin_unlock_bh(&mpath->state_lock); + +enddiscovery: + rcu_read_unlock(); + kfree(preq_node); +} + +/** + * mesh_nexthop_resolve - lookup next hop; conditionally start path discovery + * + * @skb: 802.11 frame to be sent + * @sdata: network subif the frame will be sent through + * + * Lookup next hop for given skb and start path discovery if no + * forwarding information is found. + * + * Returns: 0 if the next hop was found and -ENOENT if the frame was queued. + * skb is freeed here if no mpath could be allocated. + */ +int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata, + struct sk_buff *skb) +{ + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + struct mesh_path *mpath; + struct sk_buff *skb_to_free = NULL; + u8 *target_addr = hdr->addr3; + int err = 0; + + /* Nulls are only sent to peers for PS and should be pre-addressed */ + if (ieee80211_is_qos_nullfunc(hdr->frame_control)) + return 0; + + rcu_read_lock(); + err = mesh_nexthop_lookup(sdata, skb); + if (!err) + goto endlookup; + + /* no nexthop found, start resolving */ + mpath = mesh_path_lookup(sdata, target_addr); + if (!mpath) { + mpath = mesh_path_add(sdata, target_addr); + if (IS_ERR(mpath)) { + mesh_path_discard_frame(sdata, skb); + err = PTR_ERR(mpath); + goto endlookup; + } + } + + if (!(mpath->flags & MESH_PATH_RESOLVING) && + mesh_path_sel_is_hwmp(sdata)) + mesh_queue_preq(mpath, PREQ_Q_F_START); + + if (skb_queue_len(&mpath->frame_queue) >= MESH_FRAME_QUEUE_LEN) + skb_to_free = skb_dequeue(&mpath->frame_queue); + + info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING; + ieee80211_set_qos_hdr(sdata, skb); + skb_queue_tail(&mpath->frame_queue, skb); + err = -ENOENT; + if (skb_to_free) + mesh_path_discard_frame(sdata, skb_to_free); + +endlookup: + rcu_read_unlock(); + return err; +} + +/** + * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling + * this function is considered "using" the associated mpath, so preempt a path + * refresh if this mpath expires soon. + * + * @skb: 802.11 frame to be sent + * @sdata: network subif the frame will be sent through + * + * Returns: 0 if the next hop was found. Nonzero otherwise. + */ +int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata, + struct sk_buff *skb) +{ + struct mesh_path *mpath; + struct sta_info *next_hop; + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; + u8 *target_addr = hdr->addr3; + int err = -ENOENT; + + rcu_read_lock(); + mpath = mesh_path_lookup(sdata, target_addr); + + if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE)) + goto endlookup; + + if (time_after(jiffies, + mpath->exp_time - + msecs_to_jiffies(sdata->u.mesh.mshcfg.path_refresh_time)) && + ether_addr_equal(sdata->vif.addr, hdr->addr4) && + !(mpath->flags & MESH_PATH_RESOLVING) && + !(mpath->flags & MESH_PATH_FIXED)) + mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); + + next_hop = rcu_dereference(mpath->next_hop); + if (next_hop) { + memcpy(hdr->addr1, next_hop->sta.addr, ETH_ALEN); + memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN); + ieee80211_mps_set_frame_flags(sdata, next_hop, hdr); + err = 0; + } + +endlookup: + rcu_read_unlock(); + return err; +} + +void mesh_path_timer(struct timer_list *t) +{ + struct mesh_path *mpath = from_timer(mpath, t, timer); + struct ieee80211_sub_if_data *sdata = mpath->sdata; + int ret; + + if (sdata->local->quiescing) + return; + + spin_lock_bh(&mpath->state_lock); + if (mpath->flags & MESH_PATH_RESOLVED || + (!(mpath->flags & MESH_PATH_RESOLVING))) { + mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED); + spin_unlock_bh(&mpath->state_lock); + } else if (mpath->discovery_retries < max_preq_retries(sdata)) { + ++mpath->discovery_retries; + mpath->discovery_timeout *= 2; + mpath->flags &= ~MESH_PATH_REQ_QUEUED; + spin_unlock_bh(&mpath->state_lock); + mesh_queue_preq(mpath, 0); + } else { + mpath->flags &= ~(MESH_PATH_RESOLVING | + MESH_PATH_RESOLVED | + MESH_PATH_REQ_QUEUED); + mpath->exp_time = jiffies; + spin_unlock_bh(&mpath->state_lock); + if (!mpath->is_gate && mesh_gate_num(sdata) > 0) { + ret = mesh_path_send_to_gates(mpath); + if (ret) + mhwmp_dbg(sdata, "no gate was reachable\n"); + } else + mesh_path_flush_pending(mpath); + } +} + +void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata) +{ + struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; + u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval; + u8 flags, target_flags = 0; + + flags = (ifmsh->mshcfg.dot11MeshGateAnnouncementProtocol) + ? RANN_FLAG_IS_GATE : 0; + + switch (ifmsh->mshcfg.dot11MeshHWMPRootMode) { + case IEEE80211_PROACTIVE_RANN: + mesh_path_sel_frame_tx(MPATH_RANN, flags, sdata->vif.addr, + ++ifmsh->sn, 0, NULL, 0, broadcast_addr, + 0, ifmsh->mshcfg.element_ttl, + interval, 0, 0, sdata); + break; + case IEEE80211_PROACTIVE_PREQ_WITH_PREP: + flags |= IEEE80211_PREQ_PROACTIVE_PREP_FLAG; + /* fall through */ + case IEEE80211_PROACTIVE_PREQ_NO_PREP: + interval = ifmsh->mshcfg.dot11MeshHWMPactivePathToRootTimeout; + target_flags |= IEEE80211_PREQ_TO_FLAG | + IEEE80211_PREQ_USN_FLAG; + mesh_path_sel_frame_tx(MPATH_PREQ, flags, sdata->vif.addr, + ++ifmsh->sn, target_flags, + (u8 *) broadcast_addr, 0, broadcast_addr, + 0, ifmsh->mshcfg.element_ttl, interval, + 0, ifmsh->preq_id++, sdata); + break; + default: + mhwmp_dbg(sdata, "Proactive mechanism not supported\n"); + return; + } +} |