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Release 4.8 net/mac80211/mesh_hwmp.c

Directory: net/mac80211
/*
 * 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 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); }

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PersonTokensPropCommitsCommitProp
luis carlos cobo rusluis carlos cobo rus3294.12%133.33%
harvey harrisonharvey harrison12.94%133.33%
johannes bergjohannes berg12.94%133.33%
Total34100.00%3100.00%


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); }

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PersonTokensPropCommitsCommitProp
rui paulorui paulo3294.12%133.33%
johannes bergjohannes berg12.94%133.33%
bob copelandbob copeland12.94%133.33%
Total34100.00%3100.00%

/* 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; }

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PersonTokensPropCommitsCommitProp
jesse jonesjesse jones26100.00%1100.00%
Total26100.00%1100.00%

#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 = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) + sizeof(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 = (struct ieee80211_mgmt *) skb_put(skb, hdr_len); memset(mgmt, 0, 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; }

Contributors

PersonTokensPropCommitsCommitProp
luis carlos cobo rusluis carlos cobo rus34459.21%15.56%
thomas pedersenthomas pedersen11519.79%211.11%
rui paulorui paulo7112.22%422.22%
chun-yeow yeohchun-yeow yeoh203.44%211.11%
johannes bergjohannes berg193.27%527.78%
jasper bryant-greenejasper bryant-greene71.20%15.56%
javier cardonajavier cardona20.34%15.56%
harvey harrisonharvey harrison20.34%15.56%
patrick mchardypatrick mchardy10.17%15.56%
Total581100.00%18100.00%

/* 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); }

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PersonTokensPropCommitsCommitProp
javier cardonajavier cardona7068.63%240.00%
marco porschmarco porsch2322.55%120.00%
bob copelandbob copeland65.88%120.00%
zhang shengjuzhang shengju32.94%120.00%
Total102100.00%5100.00%

/** * 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 = offsetof(struct ieee80211_mgmt, u.action.u.mesh_action) + sizeof(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 = (struct ieee80211_mgmt *) skb_put(skb, hdr_len); memset(mgmt, 0, 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; }

Contributors

PersonTokensPropCommitsCommitProp
luis carlos cobo rusluis carlos cobo rus18851.23%15.26%
thomas pedersenthomas pedersen10528.61%315.79%
rui paulorui paulo287.63%210.53%
javier cardonajavier cardona123.27%315.79%
johannes bergjohannes berg102.72%421.05%
chun-yeow yeohchun-yeow yeoh71.91%210.53%
max stepanovmax stepanov61.63%15.26%
jasper bryant-greenejasper bryant-greene51.36%15.26%
bob copelandbob copeland41.09%15.26%
harvey harrisonharvey harrison20.54%15.26%
Total367100.00%19100.00%


void ieee80211s_update_metric(struct ieee80211_local *local, struct sta_info *sta, struct sk_buff *skb) { struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb); struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; int failed; if (!ieee80211_is_data(hdr->frame_control)) return; failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK); /* moving average, scaled to 100 */ sta->mesh->fail_avg = ((80 * sta->mesh->fail_avg + 5) / 100 + 20 * failed); if (sta->mesh->fail_avg > 95) mesh_plink_broken(sta); }

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PersonTokensPropCommitsCommitProp
javier cardonajavier cardona10594.59%266.67%
johannes bergjohannes berg65.41%133.33%
Total111100.00%3100.00%


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; if (sta->mesh->fail_avg >= 100) 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 = (sta->mesh->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 = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ; return (u32)result; }

Contributors

PersonTokensPropCommitsCommitProp
luis carlos cobo rusluis carlos cobo rus12875.74%120.00%
thomas pedersenthomas pedersen2715.98%120.00%
johannes bergjohannes berg148.28%360.00%
Total169100.00%5100.00%

/** * 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); 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); mesh_path_tx_pending(mpath); } else spin_unlock_bh(&mpath->state_lock); } rcu_read_unlock(); return process ? new_metric : 0; }

Contributors

PersonTokensPropCommitsCommitProp
luis carlos cobo rusluis carlos cobo rus57879.07%17.14%
jesse jonesjesse jones9012.31%17.14%
johannes bergjohannes berg223.01%535.71%
rui paulorui paulo172.33%214.29%
jasper bryant-greenejasper bryant-greene101.37%17.14%
bob copelandbob copeland81.09%17.14%
thomas pedersenthomas pedersen30.41%17.14%
joe perchesjoe perches20.27%17.14%
marco porschmarco porsch10.14%17.14%
Total731100.00%14100.00%


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 (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