/* $OpenBSD: ieee80211_amrr.c,v 1.1 2006/06/17 19:07:19 damien Exp $ */ /*- * Copyright (c) 2010 Rui Paulo * Copyright (c) 2006 * Damien Bergamini * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include __FBSDID("$FreeBSD$"); /*- * Naive implementation of the Adaptive Multi Rate Retry algorithm: * * "IEEE 802.11 Rate Adaptation: A Practical Approach" * Mathieu Lacage, Hossein Manshaei, Thierry Turletti * INRIA Sophia - Projet Planete * http://www-sop.inria.fr/rapports/sophia/RR-5208.html */ #include "opt_wlan.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define is_success(amn) \ ((amn)->amn_retrycnt < (amn)->amn_txcnt / 10) #define is_failure(amn) \ ((amn)->amn_retrycnt > (amn)->amn_txcnt / 3) #define is_enough(amn) \ ((amn)->amn_txcnt > 10) static void amrr_setinterval(const struct ieee80211vap *, int); static void amrr_init(struct ieee80211vap *); static void amrr_deinit(struct ieee80211vap *); static void amrr_node_init(struct ieee80211_node *); static void amrr_node_deinit(struct ieee80211_node *); static int amrr_update(struct ieee80211_amrr *, struct ieee80211_amrr_node *, struct ieee80211_node *); static int amrr_rate(struct ieee80211_node *, void *, uint32_t); static void amrr_tx_complete(const struct ieee80211vap *, const struct ieee80211_node *, int, void *, void *); static void amrr_tx_update(const struct ieee80211vap *vap, const struct ieee80211_node *, void *, void *, void *); static void amrr_sysctlattach(struct ieee80211vap *, struct sysctl_ctx_list *, struct sysctl_oid *); static void amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s); /* number of references from net80211 layer */ static int nrefs = 0; static const struct ieee80211_ratectl amrr = { .ir_name = "amrr", .ir_attach = NULL, .ir_detach = NULL, .ir_init = amrr_init, .ir_deinit = amrr_deinit, .ir_node_init = amrr_node_init, .ir_node_deinit = amrr_node_deinit, .ir_rate = amrr_rate, .ir_tx_complete = amrr_tx_complete, .ir_tx_update = amrr_tx_update, .ir_setinterval = amrr_setinterval, .ir_node_stats = amrr_node_stats, }; IEEE80211_RATECTL_MODULE(amrr, 1); IEEE80211_RATECTL_ALG(amrr, IEEE80211_RATECTL_AMRR, amrr); static void amrr_setinterval(const struct ieee80211vap *vap, int msecs) { struct ieee80211_amrr *amrr = vap->iv_rs; int t; if (msecs < 100) msecs = 100; t = msecs_to_ticks(msecs); amrr->amrr_interval = (t < 1) ? 1 : t; } static void amrr_init(struct ieee80211vap *vap) { struct ieee80211_amrr *amrr; KASSERT(vap->iv_rs == NULL, ("%s called multiple times", __func__)); #if defined(__DragonFly__) amrr = vap->iv_rs = kmalloc(sizeof(struct ieee80211_amrr), M_80211_RATECTL, M_INTWAIT|M_ZERO); #else amrr = vap->iv_rs = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr), M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); #endif if (amrr == NULL) { if_printf(vap->iv_ifp, "couldn't alloc ratectl structure\n"); return; } amrr->amrr_min_success_threshold = IEEE80211_AMRR_MIN_SUCCESS_THRESHOLD; amrr->amrr_max_success_threshold = IEEE80211_AMRR_MAX_SUCCESS_THRESHOLD; amrr_setinterval(vap, 500 /* ms */); amrr_sysctlattach(vap, vap->iv_sysctl, vap->iv_oid); } static void amrr_deinit(struct ieee80211vap *vap) { IEEE80211_FREE(vap->iv_rs, M_80211_RATECTL); } /* * Return whether 11n rates are possible. * * Some 11n devices may return HT information but no HT rates. * Thus, we shouldn't treat them as an 11n node. */ static int amrr_node_is_11n(struct ieee80211_node *ni) { if (ni->ni_chan == NULL) return (0); if (ni->ni_chan == IEEE80211_CHAN_ANYC) return (0); if (IEEE80211_IS_CHAN_HT(ni->ni_chan) && ni->ni_htrates.rs_nrates == 0) return (0); return (IEEE80211_IS_CHAN_HT(ni->ni_chan)); } static void amrr_node_init(struct ieee80211_node *ni) { const struct ieee80211_rateset *rs = NULL; struct ieee80211vap *vap = ni->ni_vap; struct ieee80211_amrr *amrr = vap->iv_rs; struct ieee80211_amrr_node *amn; uint8_t rate; if (ni->ni_rctls == NULL) { #if defined(__DragonFly__) ni->ni_rctls = amn = kmalloc(sizeof(struct ieee80211_amrr_node), M_80211_RATECTL, M_INTWAIT|M_ZERO); #else ni->ni_rctls = amn = IEEE80211_MALLOC(sizeof(struct ieee80211_amrr_node), M_80211_RATECTL, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); #endif if (amn == NULL) { if_printf(vap->iv_ifp, "couldn't alloc per-node ratectl " "structure\n"); return; } } else amn = ni->ni_rctls; amn->amn_amrr = amrr; amn->amn_success = 0; amn->amn_recovery = 0; amn->amn_txcnt = amn->amn_retrycnt = 0; amn->amn_success_threshold = amrr->amrr_min_success_threshold; /* 11n or not? Pick the right rateset */ if (amrr_node_is_11n(ni)) { /* XXX ew */ IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, "%s: 11n node", __func__); rs = (struct ieee80211_rateset *) &ni->ni_htrates; } else { IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, "%s: non-11n node", __func__); rs = &ni->ni_rates; } /* Initial rate - lowest */ rate = rs->rs_rates[0]; /* XXX clear the basic rate flag if it's not 11n */ if (! amrr_node_is_11n(ni)) rate &= IEEE80211_RATE_VAL; /* pick initial rate from the rateset - HT or otherwise */ /* Pick something low that's likely to succeed */ for (amn->amn_rix = rs->rs_nrates - 1; amn->amn_rix > 0; amn->amn_rix--) { /* legacy - anything < 36mbit, stop searching */ /* 11n - stop at MCS4 */ if (amrr_node_is_11n(ni)) { if ((rs->rs_rates[amn->amn_rix] & 0x1f) < 4) break; } else if ((rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL) <= 72) break; } rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; /* if the rate is an 11n rate, ensure the MCS bit is set */ if (amrr_node_is_11n(ni)) rate |= IEEE80211_RATE_MCS; /* Assign initial rate from the rateset */ ni->ni_txrate = rate; amn->amn_ticks = ticks; IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, "AMRR: nrates=%d, initial rate %d", rs->rs_nrates, rate); } static void amrr_node_deinit(struct ieee80211_node *ni) { IEEE80211_FREE(ni->ni_rctls, M_80211_RATECTL); } static int amrr_update(struct ieee80211_amrr *amrr, struct ieee80211_amrr_node *amn, struct ieee80211_node *ni) { int rix = amn->amn_rix; const struct ieee80211_rateset *rs = NULL; KASSERT(is_enough(amn), ("txcnt %d", amn->amn_txcnt)); /* 11n or not? Pick the right rateset */ if (amrr_node_is_11n(ni)) { /* XXX ew */ rs = (struct ieee80211_rateset *) &ni->ni_htrates; } else { rs = &ni->ni_rates; } IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, "AMRR: current rate %d, txcnt=%d, retrycnt=%d", rs->rs_rates[rix] & IEEE80211_RATE_VAL, amn->amn_txcnt, amn->amn_retrycnt); /* * XXX This is totally bogus for 11n, as although high MCS * rates for each stream may be failing, the next stream * should be checked. * * Eg, if MCS5 is ok but MCS6/7 isn't, and we can go up to * MCS23, we should skip 6/7 and try 8 onwards. */ if (is_success(amn)) { amn->amn_success++; if (amn->amn_success >= amn->amn_success_threshold && rix + 1 < rs->rs_nrates) { amn->amn_recovery = 1; amn->amn_success = 0; rix++; IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, "AMRR increasing rate %d (txcnt=%d retrycnt=%d)", rs->rs_rates[rix] & IEEE80211_RATE_VAL, amn->amn_txcnt, amn->amn_retrycnt); } else { amn->amn_recovery = 0; } } else if (is_failure(amn)) { amn->amn_success = 0; if (rix > 0) { if (amn->amn_recovery) { amn->amn_success_threshold *= 2; if (amn->amn_success_threshold > amrr->amrr_max_success_threshold) amn->amn_success_threshold = amrr->amrr_max_success_threshold; } else { amn->amn_success_threshold = amrr->amrr_min_success_threshold; } rix--; IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_RATECTL, ni, "AMRR decreasing rate %d (txcnt=%d retrycnt=%d)", rs->rs_rates[rix] & IEEE80211_RATE_VAL, amn->amn_txcnt, amn->amn_retrycnt); } amn->amn_recovery = 0; } /* reset counters */ amn->amn_txcnt = 0; amn->amn_retrycnt = 0; return rix; } /* * Return the rate index to use in sending a data frame. * Update our internal state if it's been long enough. * If the rate changes we also update ni_txrate to match. */ static int amrr_rate(struct ieee80211_node *ni, void *arg __unused, uint32_t iarg __unused) { struct ieee80211_amrr_node *amn = ni->ni_rctls; struct ieee80211_amrr *amrr = amn->amn_amrr; const struct ieee80211_rateset *rs = NULL; int rix; /* 11n or not? Pick the right rateset */ if (amrr_node_is_11n(ni)) { /* XXX ew */ rs = (struct ieee80211_rateset *) &ni->ni_htrates; } else { rs = &ni->ni_rates; } if (is_enough(amn) && (ticks - amn->amn_ticks) > amrr->amrr_interval) { rix = amrr_update(amrr, amn, ni); if (rix != amn->amn_rix) { /* update public rate */ ni->ni_txrate = rs->rs_rates[rix]; /* XXX strip basic rate flag from txrate, if non-11n */ if (amrr_node_is_11n(ni)) ni->ni_txrate |= IEEE80211_RATE_MCS; else ni->ni_txrate &= IEEE80211_RATE_VAL; amn->amn_rix = rix; } amn->amn_ticks = ticks; } else rix = amn->amn_rix; return rix; } /* * Update statistics with tx complete status. Ok is non-zero * if the packet is known to be ACK'd. Retries has the number * retransmissions (i.e. xmit attempts - 1). */ static void amrr_tx_complete(const struct ieee80211vap *vap, const struct ieee80211_node *ni, int ok, void *arg1, void *arg2 __unused) { struct ieee80211_amrr_node *amn = ni->ni_rctls; int retries = *(int *)arg1; amn->amn_txcnt++; if (ok) amn->amn_success++; amn->amn_retrycnt += retries; } /* * Set tx count/retry statistics explicitly. Intended for * drivers that poll the device for statistics maintained * in the device. */ static void amrr_tx_update(const struct ieee80211vap *vap, const struct ieee80211_node *ni, void *arg1, void *arg2, void *arg3) { struct ieee80211_amrr_node *amn = ni->ni_rctls; int txcnt = *(int *)arg1, success = *(int *)arg2, retrycnt = *(int *)arg3; amn->amn_txcnt = txcnt; amn->amn_success = success; amn->amn_retrycnt = retrycnt; } static int amrr_sysctl_interval(SYSCTL_HANDLER_ARGS) { struct ieee80211vap *vap = arg1; struct ieee80211_amrr *amrr = vap->iv_rs; int msecs = ticks_to_msecs(amrr->amrr_interval); int error; error = sysctl_handle_int(oidp, &msecs, 0, req); if (error || !req->newptr) return error; amrr_setinterval(vap, msecs); return 0; } static void amrr_sysctlattach(struct ieee80211vap *vap, struct sysctl_ctx_list *ctx, struct sysctl_oid *tree) { struct ieee80211_amrr *amrr = vap->iv_rs; SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "amrr_rate_interval", CTLTYPE_INT | CTLFLAG_RW, vap, 0, amrr_sysctl_interval, "I", "amrr operation interval (ms)"); /* XXX bounds check values */ SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "amrr_max_sucess_threshold", CTLFLAG_RW, &amrr->amrr_max_success_threshold, 0, ""); SYSCTL_ADD_UINT(ctx, SYSCTL_CHILDREN(tree), OID_AUTO, "amrr_min_sucess_threshold", CTLFLAG_RW, &amrr->amrr_min_success_threshold, 0, ""); } static void amrr_node_stats(struct ieee80211_node *ni, struct sbuf *s) { int rate; struct ieee80211_amrr_node *amn = ni->ni_rctls; struct ieee80211_rateset *rs; /* XXX TODO: check locking? */ /* XXX TODO: this should be a method */ if (amrr_node_is_11n(ni)) { rs = (struct ieee80211_rateset *) &ni->ni_htrates; rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; sbuf_printf(s, "rate: MCS %d\n", rate); } else { rs = &ni->ni_rates; rate = rs->rs_rates[amn->amn_rix] & IEEE80211_RATE_VAL; sbuf_printf(s, "rate: %d Mbit\n", rate / 2); } sbuf_printf(s, "ticks: %d\n", amn->amn_ticks); sbuf_printf(s, "txcnt: %u\n", amn->amn_txcnt); sbuf_printf(s, "success: %u\n", amn->amn_success); sbuf_printf(s, "success_threshold: %u\n", amn->amn_success_threshold); sbuf_printf(s, "recovery: %u\n", amn->amn_recovery); sbuf_printf(s, "retry_cnt: %u\n", amn->amn_retrycnt); }