/* * Copyright 2002-2005, Instant802 Networks, Inc. * Copyright 2005-2006, Devicescape Software, Inc. * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz> * * 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/kernel.h> #include <linux/rtnetlink.h> #include "rate.h" #include "ieee80211_i.h" struct rate_control_alg { struct list_head list; struct rate_control_ops *ops; }; static LIST_HEAD(rate_ctrl_algs); static DEFINE_MUTEX(rate_ctrl_mutex); static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT; module_param(ieee80211_default_rc_algo, charp, 0644); MODULE_PARM_DESC(ieee80211_default_rc_algo, "Default rate control algorithm for mac80211 to use"); int ieee80211_rate_control_register(struct rate_control_ops *ops) { struct rate_control_alg *alg; if (!ops->name) return -EINVAL; mutex_lock(&rate_ctrl_mutex); list_for_each_entry(alg, &rate_ctrl_algs, list) { if (!strcmp(alg->ops->name, ops->name)) { /* don't register an algorithm twice */ WARN_ON(1); mutex_unlock(&rate_ctrl_mutex); return -EALREADY; } } alg = kzalloc(sizeof(*alg), GFP_KERNEL); if (alg == NULL) { mutex_unlock(&rate_ctrl_mutex); return -ENOMEM; } alg->ops = ops; list_add_tail(&alg->list, &rate_ctrl_algs); mutex_unlock(&rate_ctrl_mutex); return 0; } EXPORT_SYMBOL(ieee80211_rate_control_register); void ieee80211_rate_control_unregister(struct rate_control_ops *ops) { struct rate_control_alg *alg; mutex_lock(&rate_ctrl_mutex); list_for_each_entry(alg, &rate_ctrl_algs, list) { if (alg->ops == ops) { list_del(&alg->list); kfree(alg); break; } } mutex_unlock(&rate_ctrl_mutex); } EXPORT_SYMBOL(ieee80211_rate_control_unregister); static struct rate_control_ops * ieee80211_try_rate_control_ops_get(const char *name) { struct rate_control_alg *alg; struct rate_control_ops *ops = NULL; if (!name) return NULL; mutex_lock(&rate_ctrl_mutex); list_for_each_entry(alg, &rate_ctrl_algs, list) { if (!strcmp(alg->ops->name, name)) if (try_module_get(alg->ops->module)) { ops = alg->ops; break; } } mutex_unlock(&rate_ctrl_mutex); return ops; } /* Get the rate control algorithm. */ static struct rate_control_ops * ieee80211_rate_control_ops_get(const char *name) { struct rate_control_ops *ops; const char *alg_name; if (!name) alg_name = ieee80211_default_rc_algo; else alg_name = name; ops = ieee80211_try_rate_control_ops_get(alg_name); if (!ops) { request_module("rc80211_%s", alg_name); ops = ieee80211_try_rate_control_ops_get(alg_name); } if (!ops && name) /* try default if specific alg requested but not found */ ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo); /* try built-in one if specific alg requested but not found */ if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT)) ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT); return ops; } static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops) { module_put(ops->module); } struct rate_control_ref *rate_control_alloc(const char *name, struct ieee80211_local *local) { struct rate_control_ref *ref; ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL); if (!ref) goto fail_ref; kref_init(&ref->kref); ref->ops = ieee80211_rate_control_ops_get(name); if (!ref->ops) goto fail_ops; ref->priv = ref->ops->alloc(local); if (!ref->priv) goto fail_priv; return ref; fail_priv: ieee80211_rate_control_ops_put(ref->ops); fail_ops: kfree(ref); fail_ref: return NULL; } static void rate_control_release(struct kref *kref) { struct rate_control_ref *ctrl_ref; ctrl_ref = container_of(kref, struct rate_control_ref, kref); ctrl_ref->ops->free(ctrl_ref->priv); ieee80211_rate_control_ops_put(ctrl_ref->ops); kfree(ctrl_ref); } void rate_control_get_rate(struct net_device *dev, struct ieee80211_supported_band *sband, struct sk_buff *skb, struct rate_selection *sel) { struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr); struct rate_control_ref *ref = local->rate_ctrl; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; struct sta_info *sta; int i; rcu_read_lock(); sta = sta_info_get(local, hdr->addr1); sel->rate_idx = -1; sel->nonerp_idx = -1; sel->probe_idx = -1; ref->ops->get_rate(ref->priv, dev, sband, skb, sel); BUG_ON(sel->rate_idx < 0); /* Select a non-ERP backup rate. */ if (sel->nonerp_idx < 0) { for (i = 0; i < sband->n_bitrates; i++) { struct ieee80211_rate *rate = &sband->bitrates[i]; if (sband->bitrates[sel->rate_idx].bitrate < rate->bitrate) break; if (rate_supported(sta, sband->band, i) && !(rate->flags & IEEE80211_RATE_ERP_G)) sel->nonerp_idx = i; } } rcu_read_unlock(); } struct rate_control_ref *rate_control_get(struct rate_control_ref *ref) { kref_get(&ref->kref); return ref; } void rate_control_put(struct rate_control_ref *ref) { kref_put(&ref->kref, rate_control_release); } int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local, const char *name) { struct rate_control_ref *ref, *old; ASSERT_RTNL(); if (local->open_count || netif_running(local->mdev)) return -EBUSY; ref = rate_control_alloc(name, local); if (!ref) { printk(KERN_WARNING "%s: Failed to select rate control " "algorithm\n", wiphy_name(local->hw.wiphy)); return -ENOENT; } old = local->rate_ctrl; local->rate_ctrl = ref; if (old) { rate_control_put(old); sta_info_flush(local, NULL); } printk(KERN_DEBUG "%s: Selected rate control " "algorithm '%s'\n", wiphy_name(local->hw.wiphy), ref->ops->name); return 0; } void rate_control_deinitialize(struct ieee80211_local *local) { struct rate_control_ref *ref; ref = local->rate_ctrl; local->rate_ctrl = NULL; rate_control_put(ref); }