| /* |
| * net/sched/sch_api.c Packet scheduler API. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
| * |
| * Fixes: |
| * |
| * Rani Assaf <rani@magic.metawire.com> :980802: JIFFIES and CPU clock sources are repaired. |
| * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support |
| * Jamal Hadi Salim <hadi@nortelnetworks.com>: 990601: ingress support |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/string.h> |
| #include <linux/errno.h> |
| #include <linux/skbuff.h> |
| #include <linux/init.h> |
| #include <linux/proc_fs.h> |
| #include <linux/seq_file.h> |
| #include <linux/kmod.h> |
| #include <linux/list.h> |
| #include <linux/hrtimer.h> |
| |
| #include <net/net_namespace.h> |
| #include <net/sock.h> |
| #include <net/netlink.h> |
| #include <net/pkt_sched.h> |
| |
| static int qdisc_notify(struct sk_buff *oskb, struct nlmsghdr *n, u32 clid, |
| struct Qdisc *old, struct Qdisc *new); |
| static int tclass_notify(struct sk_buff *oskb, struct nlmsghdr *n, |
| struct Qdisc *q, unsigned long cl, int event); |
| |
| /* |
| |
| Short review. |
| ------------- |
| |
| This file consists of two interrelated parts: |
| |
| 1. queueing disciplines manager frontend. |
| 2. traffic classes manager frontend. |
| |
| Generally, queueing discipline ("qdisc") is a black box, |
| which is able to enqueue packets and to dequeue them (when |
| device is ready to send something) in order and at times |
| determined by algorithm hidden in it. |
| |
| qdisc's are divided to two categories: |
| - "queues", which have no internal structure visible from outside. |
| - "schedulers", which split all the packets to "traffic classes", |
| using "packet classifiers" (look at cls_api.c) |
| |
| In turn, classes may have child qdiscs (as rule, queues) |
| attached to them etc. etc. etc. |
| |
| The goal of the routines in this file is to translate |
| information supplied by user in the form of handles |
| to more intelligible for kernel form, to make some sanity |
| checks and part of work, which is common to all qdiscs |
| and to provide rtnetlink notifications. |
| |
| All real intelligent work is done inside qdisc modules. |
| |
| |
| |
| Every discipline has two major routines: enqueue and dequeue. |
| |
| ---dequeue |
| |
| dequeue usually returns a skb to send. It is allowed to return NULL, |
| but it does not mean that queue is empty, it just means that |
| discipline does not want to send anything this time. |
| Queue is really empty if q->q.qlen == 0. |
| For complicated disciplines with multiple queues q->q is not |
| real packet queue, but however q->q.qlen must be valid. |
| |
| ---enqueue |
| |
| enqueue returns 0, if packet was enqueued successfully. |
| If packet (this one or another one) was dropped, it returns |
| not zero error code. |
| NET_XMIT_DROP - this packet dropped |
| Expected action: do not backoff, but wait until queue will clear. |
| NET_XMIT_CN - probably this packet enqueued, but another one dropped. |
| Expected action: backoff or ignore |
| NET_XMIT_POLICED - dropped by police. |
| Expected action: backoff or error to real-time apps. |
| |
| Auxiliary routines: |
| |
| ---requeue |
| |
| requeues once dequeued packet. It is used for non-standard or |
| just buggy devices, which can defer output even if dev->tbusy=0. |
| |
| ---reset |
| |
| returns qdisc to initial state: purge all buffers, clear all |
| timers, counters (except for statistics) etc. |
| |
| ---init |
| |
| initializes newly created qdisc. |
| |
| ---destroy |
| |
| destroys resources allocated by init and during lifetime of qdisc. |
| |
| ---change |
| |
| changes qdisc parameters. |
| */ |
| |
| /* Protects list of registered TC modules. It is pure SMP lock. */ |
| static DEFINE_RWLOCK(qdisc_mod_lock); |
| |
| |
| /************************************************ |
| * Queueing disciplines manipulation. * |
| ************************************************/ |
| |
| |
| /* The list of all installed queueing disciplines. */ |
| |
| static struct Qdisc_ops *qdisc_base; |
| |
| /* Register/uregister queueing discipline */ |
| |
| int register_qdisc(struct Qdisc_ops *qops) |
| { |
| struct Qdisc_ops *q, **qp; |
| int rc = -EEXIST; |
| |
| write_lock(&qdisc_mod_lock); |
| for (qp = &qdisc_base; (q = *qp) != NULL; qp = &q->next) |
| if (!strcmp(qops->id, q->id)) |
| goto out; |
| |
| if (qops->enqueue == NULL) |
| qops->enqueue = noop_qdisc_ops.enqueue; |
| if (qops->requeue == NULL) |
| qops->requeue = noop_qdisc_ops.requeue; |
| if (qops->dequeue == NULL) |
| qops->dequeue = noop_qdisc_ops.dequeue; |
| |
| qops->next = NULL; |
| *qp = qops; |
| rc = 0; |
| out: |
| write_unlock(&qdisc_mod_lock); |
| return rc; |
| } |
| EXPORT_SYMBOL(register_qdisc); |
| |
| int unregister_qdisc(struct Qdisc_ops *qops) |
| { |
| struct Qdisc_ops *q, **qp; |
| int err = -ENOENT; |
| |
| write_lock(&qdisc_mod_lock); |
| for (qp = &qdisc_base; (q=*qp)!=NULL; qp = &q->next) |
| if (q == qops) |
| break; |
| if (q) { |
| *qp = q->next; |
| q->next = NULL; |
| err = 0; |
| } |
| write_unlock(&qdisc_mod_lock); |
| return err; |
| } |
| EXPORT_SYMBOL(unregister_qdisc); |
| |
| /* We know handle. Find qdisc among all qdisc's attached to device |
| (root qdisc, all its children, children of children etc.) |
| */ |
| |
| struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle) |
| { |
| struct Qdisc *q; |
| |
| list_for_each_entry(q, &dev->qdisc_list, list) { |
| if (q->handle == handle) |
| return q; |
| } |
| return NULL; |
| } |
| |
| static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid) |
| { |
| unsigned long cl; |
| struct Qdisc *leaf; |
| const struct Qdisc_class_ops *cops = p->ops->cl_ops; |
| |
| if (cops == NULL) |
| return NULL; |
| cl = cops->get(p, classid); |
| |
| if (cl == 0) |
| return NULL; |
| leaf = cops->leaf(p, cl); |
| cops->put(p, cl); |
| return leaf; |
| } |
| |
| /* Find queueing discipline by name */ |
| |
| static struct Qdisc_ops *qdisc_lookup_ops(struct rtattr *kind) |
| { |
| struct Qdisc_ops *q = NULL; |
| |
| if (kind) { |
| read_lock(&qdisc_mod_lock); |
| for (q = qdisc_base; q; q = q->next) { |
| if (rtattr_strcmp(kind, q->id) == 0) { |
| if (!try_module_get(q->owner)) |
| q = NULL; |
| break; |
| } |
| } |
| read_unlock(&qdisc_mod_lock); |
| } |
| return q; |
| } |
| |
| static struct qdisc_rate_table *qdisc_rtab_list; |
| |
| struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r, struct rtattr *tab) |
| { |
| struct qdisc_rate_table *rtab; |
| |
| for (rtab = qdisc_rtab_list; rtab; rtab = rtab->next) { |
| if (memcmp(&rtab->rate, r, sizeof(struct tc_ratespec)) == 0) { |
| rtab->refcnt++; |
| return rtab; |
| } |
| } |
| |
| if (tab == NULL || r->rate == 0 || r->cell_log == 0 || RTA_PAYLOAD(tab) != 1024) |
| return NULL; |
| |
| rtab = kmalloc(sizeof(*rtab), GFP_KERNEL); |
| if (rtab) { |
| rtab->rate = *r; |
| rtab->refcnt = 1; |
| memcpy(rtab->data, RTA_DATA(tab), 1024); |
| rtab->next = qdisc_rtab_list; |
| qdisc_rtab_list = rtab; |
| } |
| return rtab; |
| } |
| EXPORT_SYMBOL(qdisc_get_rtab); |
| |
| void qdisc_put_rtab(struct qdisc_rate_table *tab) |
| { |
| struct qdisc_rate_table *rtab, **rtabp; |
| |
| if (!tab || --tab->refcnt) |
| return; |
| |
| for (rtabp = &qdisc_rtab_list; (rtab=*rtabp) != NULL; rtabp = &rtab->next) { |
| if (rtab == tab) { |
| *rtabp = rtab->next; |
| kfree(rtab); |
| return; |
| } |
| } |
| } |
| EXPORT_SYMBOL(qdisc_put_rtab); |
| |
| static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer) |
| { |
| struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog, |
| timer); |
| struct net_device *dev = wd->qdisc->dev; |
| |
| wd->qdisc->flags &= ~TCQ_F_THROTTLED; |
| smp_wmb(); |
| netif_schedule(dev); |
| |
| return HRTIMER_NORESTART; |
| } |
| |
| void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc) |
| { |
| hrtimer_init(&wd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); |
| wd->timer.function = qdisc_watchdog; |
| wd->qdisc = qdisc; |
| } |
| EXPORT_SYMBOL(qdisc_watchdog_init); |
| |
| void qdisc_watchdog_schedule(struct qdisc_watchdog *wd, psched_time_t expires) |
| { |
| ktime_t time; |
| |
| wd->qdisc->flags |= TCQ_F_THROTTLED; |
| time = ktime_set(0, 0); |
| time = ktime_add_ns(time, PSCHED_US2NS(expires)); |
| hrtimer_start(&wd->timer, time, HRTIMER_MODE_ABS); |
| } |
| EXPORT_SYMBOL(qdisc_watchdog_schedule); |
| |
| void qdisc_watchdog_cancel(struct qdisc_watchdog *wd) |
| { |
| hrtimer_cancel(&wd->timer); |
| wd->qdisc->flags &= ~TCQ_F_THROTTLED; |
| } |
| EXPORT_SYMBOL(qdisc_watchdog_cancel); |
| |
| /* Allocate an unique handle from space managed by kernel */ |
| |
| static u32 qdisc_alloc_handle(struct net_device *dev) |
| { |
| int i = 0x10000; |
| static u32 autohandle = TC_H_MAKE(0x80000000U, 0); |
| |
| do { |
| autohandle += TC_H_MAKE(0x10000U, 0); |
| if (autohandle == TC_H_MAKE(TC_H_ROOT, 0)) |
| autohandle = TC_H_MAKE(0x80000000U, 0); |
| } while (qdisc_lookup(dev, autohandle) && --i > 0); |
| |
| return i>0 ? autohandle : 0; |
| } |
| |
| /* Attach toplevel qdisc to device dev */ |
| |
| static struct Qdisc * |
| dev_graft_qdisc(struct net_device *dev, struct Qdisc *qdisc) |
| { |
| struct Qdisc *oqdisc; |
| |
| if (dev->flags & IFF_UP) |
| dev_deactivate(dev); |
| |
| qdisc_lock_tree(dev); |
| if (qdisc && qdisc->flags&TCQ_F_INGRESS) { |
| oqdisc = dev->qdisc_ingress; |
| /* Prune old scheduler */ |
| if (oqdisc && atomic_read(&oqdisc->refcnt) <= 1) { |
| /* delete */ |
| qdisc_reset(oqdisc); |
| dev->qdisc_ingress = NULL; |
| } else { /* new */ |
| dev->qdisc_ingress = qdisc; |
| } |
| |
| } else { |
| |
| oqdisc = dev->qdisc_sleeping; |
| |
| /* Prune old scheduler */ |
| if (oqdisc && atomic_read(&oqdisc->refcnt) <= 1) |
| qdisc_reset(oqdisc); |
| |
| /* ... and graft new one */ |
| if (qdisc == NULL) |
| qdisc = &noop_qdisc; |
| dev->qdisc_sleeping = qdisc; |
| dev->qdisc = &noop_qdisc; |
| } |
| |
| qdisc_unlock_tree(dev); |
| |
| if (dev->flags & IFF_UP) |
| dev_activate(dev); |
| |
| return oqdisc; |
| } |
| |
| void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n) |
| { |
| const struct Qdisc_class_ops *cops; |
| unsigned long cl; |
| u32 parentid; |
| |
| if (n == 0) |
| return; |
| while ((parentid = sch->parent)) { |
| sch = qdisc_lookup(sch->dev, TC_H_MAJ(parentid)); |
| if (sch == NULL) { |
| WARN_ON(parentid != TC_H_ROOT); |
| return; |
| } |
| cops = sch->ops->cl_ops; |
| if (cops->qlen_notify) { |
| cl = cops->get(sch, parentid); |
| cops->qlen_notify(sch, cl); |
| cops->put(sch, cl); |
| } |
| sch->q.qlen -= n; |
| } |
| } |
| EXPORT_SYMBOL(qdisc_tree_decrease_qlen); |
| |
| /* Graft qdisc "new" to class "classid" of qdisc "parent" or |
| to device "dev". |
| |
| Old qdisc is not destroyed but returned in *old. |
| */ |
| |
| static int qdisc_graft(struct net_device *dev, struct Qdisc *parent, |
| u32 classid, |
| struct Qdisc *new, struct Qdisc **old) |
| { |
| int err = 0; |
| struct Qdisc *q = *old; |
| |
| |
| if (parent == NULL) { |
| if (q && q->flags&TCQ_F_INGRESS) { |
| *old = dev_graft_qdisc(dev, q); |
| } else { |
| *old = dev_graft_qdisc(dev, new); |
| } |
| } else { |
| const struct Qdisc_class_ops *cops = parent->ops->cl_ops; |
| |
| err = -EINVAL; |
| |
| if (cops) { |
| unsigned long cl = cops->get(parent, classid); |
| if (cl) { |
| err = cops->graft(parent, cl, new, old); |
| cops->put(parent, cl); |
| } |
| } |
| } |
| return err; |
| } |
| |
| /* |
| Allocate and initialize new qdisc. |
| |
| Parameters are passed via opt. |
| */ |
| |
| static struct Qdisc * |
| qdisc_create(struct net_device *dev, u32 parent, u32 handle, |
| struct rtattr **tca, int *errp) |
| { |
| int err; |
| struct rtattr *kind = tca[TCA_KIND-1]; |
| struct Qdisc *sch; |
| struct Qdisc_ops *ops; |
| |
| ops = qdisc_lookup_ops(kind); |
| #ifdef CONFIG_KMOD |
| if (ops == NULL && kind != NULL) { |
| char name[IFNAMSIZ]; |
| if (rtattr_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) { |
| /* We dropped the RTNL semaphore in order to |
| * perform the module load. So, even if we |
| * succeeded in loading the module we have to |
| * tell the caller to replay the request. We |
| * indicate this using -EAGAIN. |
| * We replay the request because the device may |
| * go away in the mean time. |
| */ |
| rtnl_unlock(); |
| request_module("sch_%s", name); |
| rtnl_lock(); |
| ops = qdisc_lookup_ops(kind); |
| if (ops != NULL) { |
| /* We will try again qdisc_lookup_ops, |
| * so don't keep a reference. |
| */ |
| module_put(ops->owner); |
| err = -EAGAIN; |
| goto err_out; |
| } |
| } |
| } |
| #endif |
| |
| err = -ENOENT; |
| if (ops == NULL) |
| goto err_out; |
| |
| sch = qdisc_alloc(dev, ops); |
| if (IS_ERR(sch)) { |
| err = PTR_ERR(sch); |
| goto err_out2; |
| } |
| |
| sch->parent = parent; |
| |
| if (handle == TC_H_INGRESS) { |
| sch->flags |= TCQ_F_INGRESS; |
| sch->stats_lock = &dev->ingress_lock; |
| handle = TC_H_MAKE(TC_H_INGRESS, 0); |
| } else { |
| sch->stats_lock = &dev->queue_lock; |
| if (handle == 0) { |
| handle = qdisc_alloc_handle(dev); |
| err = -ENOMEM; |
| if (handle == 0) |
| goto err_out3; |
| } |
| } |
| |
| sch->handle = handle; |
| |
| if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS-1])) == 0) { |
| if (tca[TCA_RATE-1]) { |
| err = gen_new_estimator(&sch->bstats, &sch->rate_est, |
| sch->stats_lock, |
| tca[TCA_RATE-1]); |
| if (err) { |
| /* |
| * Any broken qdiscs that would require |
| * a ops->reset() here? The qdisc was never |
| * in action so it shouldn't be necessary. |
| */ |
| if (ops->destroy) |
| ops->destroy(sch); |
| goto err_out3; |
| } |
| } |
| qdisc_lock_tree(dev); |
| list_add_tail(&sch->list, &dev->qdisc_list); |
| qdisc_unlock_tree(dev); |
| |
| return sch; |
| } |
| err_out3: |
| dev_put(dev); |
| kfree((char *) sch - sch->padded); |
| err_out2: |
| module_put(ops->owner); |
| err_out: |
| *errp = err; |
| return NULL; |
| } |
| |
| static int qdisc_change(struct Qdisc *sch, struct rtattr **tca) |
| { |
| if (tca[TCA_OPTIONS-1]) { |
| int err; |
| |
| if (sch->ops->change == NULL) |
| return -EINVAL; |
| err = sch->ops->change(sch, tca[TCA_OPTIONS-1]); |
| if (err) |
| return err; |
| } |
| if (tca[TCA_RATE-1]) |
| gen_replace_estimator(&sch->bstats, &sch->rate_est, |
| sch->stats_lock, tca[TCA_RATE-1]); |
| return 0; |
| } |
| |
| struct check_loop_arg |
| { |
| struct qdisc_walker w; |
| struct Qdisc *p; |
| int depth; |
| }; |
| |
| static int check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w); |
| |
| static int check_loop(struct Qdisc *q, struct Qdisc *p, int depth) |
| { |
| struct check_loop_arg arg; |
| |
| if (q->ops->cl_ops == NULL) |
| return 0; |
| |
| arg.w.stop = arg.w.skip = arg.w.count = 0; |
| arg.w.fn = check_loop_fn; |
| arg.depth = depth; |
| arg.p = p; |
| q->ops->cl_ops->walk(q, &arg.w); |
| return arg.w.stop ? -ELOOP : 0; |
| } |
| |
| static int |
| check_loop_fn(struct Qdisc *q, unsigned long cl, struct qdisc_walker *w) |
| { |
| struct Qdisc *leaf; |
| const struct Qdisc_class_ops *cops = q->ops->cl_ops; |
| struct check_loop_arg *arg = (struct check_loop_arg *)w; |
| |
| leaf = cops->leaf(q, cl); |
| if (leaf) { |
| if (leaf == arg->p || arg->depth > 7) |
| return -ELOOP; |
| return check_loop(leaf, arg->p, arg->depth + 1); |
| } |
| return 0; |
| } |
| |
| /* |
| * Delete/get qdisc. |
| */ |
| |
| static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg) |
| { |
| struct net *net = skb->sk->sk_net; |
| struct tcmsg *tcm = NLMSG_DATA(n); |
| struct rtattr **tca = arg; |
| struct net_device *dev; |
| u32 clid = tcm->tcm_parent; |
| struct Qdisc *q = NULL; |
| struct Qdisc *p = NULL; |
| int err; |
| |
| if (net != &init_net) |
| return -EINVAL; |
| |
| if ((dev = __dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL) |
| return -ENODEV; |
| |
| if (clid) { |
| if (clid != TC_H_ROOT) { |
| if (TC_H_MAJ(clid) != TC_H_MAJ(TC_H_INGRESS)) { |
| if ((p = qdisc_lookup(dev, TC_H_MAJ(clid))) == NULL) |
| return -ENOENT; |
| q = qdisc_leaf(p, clid); |
| } else { /* ingress */ |
| q = dev->qdisc_ingress; |
| } |
| } else { |
| q = dev->qdisc_sleeping; |
| } |
| if (!q) |
| return -ENOENT; |
| |
| if (tcm->tcm_handle && q->handle != tcm->tcm_handle) |
| return -EINVAL; |
| } else { |
| if ((q = qdisc_lookup(dev, tcm->tcm_handle)) == NULL) |
| return -ENOENT; |
| } |
| |
| if (tca[TCA_KIND-1] && rtattr_strcmp(tca[TCA_KIND-1], q->ops->id)) |
| return -EINVAL; |
| |
| if (n->nlmsg_type == RTM_DELQDISC) { |
| if (!clid) |
| return -EINVAL; |
| if (q->handle == 0) |
| return -ENOENT; |
| if ((err = qdisc_graft(dev, p, clid, NULL, &q)) != 0) |
| return err; |
| if (q) { |
| qdisc_notify(skb, n, clid, q, NULL); |
| qdisc_lock_tree(dev); |
| qdisc_destroy(q); |
| qdisc_unlock_tree(dev); |
| } |
| } else { |
| qdisc_notify(skb, n, clid, NULL, q); |
| } |
| return 0; |
| } |
| |
| /* |
| Create/change qdisc. |
| */ |
| |
| static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n, void *arg) |
| { |
| struct net *net = skb->sk->sk_net; |
| struct tcmsg *tcm; |
| struct rtattr **tca; |
| struct net_device *dev; |
| u32 clid; |
| struct Qdisc *q, *p; |
| int err; |
| |
| if (net != &init_net) |
| return -EINVAL; |
| |
| replay: |
| /* Reinit, just in case something touches this. */ |
| tcm = NLMSG_DATA(n); |
| tca = arg; |
| clid = tcm->tcm_parent; |
| q = p = NULL; |
| |
| if ((dev = __dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL) |
| return -ENODEV; |
| |
| if (clid) { |
| if (clid != TC_H_ROOT) { |
| if (clid != TC_H_INGRESS) { |
| if ((p = qdisc_lookup(dev, TC_H_MAJ(clid))) == NULL) |
| return -ENOENT; |
| q = qdisc_leaf(p, clid); |
| } else { /*ingress */ |
| q = dev->qdisc_ingress; |
| } |
| } else { |
| q = dev->qdisc_sleeping; |
| } |
| |
| /* It may be default qdisc, ignore it */ |
| if (q && q->handle == 0) |
| q = NULL; |
| |
| if (!q || !tcm->tcm_handle || q->handle != tcm->tcm_handle) { |
| if (tcm->tcm_handle) { |
| if (q && !(n->nlmsg_flags&NLM_F_REPLACE)) |
| return -EEXIST; |
| if (TC_H_MIN(tcm->tcm_handle)) |
| return -EINVAL; |
| if ((q = qdisc_lookup(dev, tcm->tcm_handle)) == NULL) |
| goto create_n_graft; |
| if (n->nlmsg_flags&NLM_F_EXCL) |
| return -EEXIST; |
| if (tca[TCA_KIND-1] && rtattr_strcmp(tca[TCA_KIND-1], q->ops->id)) |
| return -EINVAL; |
| if (q == p || |
| (p && check_loop(q, p, 0))) |
| return -ELOOP; |
| atomic_inc(&q->refcnt); |
| goto graft; |
| } else { |
| if (q == NULL) |
| goto create_n_graft; |
| |
| /* This magic test requires explanation. |
| * |
| * We know, that some child q is already |
| * attached to this parent and have choice: |
| * either to change it or to create/graft new one. |
| * |
| * 1. We are allowed to create/graft only |
| * if CREATE and REPLACE flags are set. |
| * |
| * 2. If EXCL is set, requestor wanted to say, |
| * that qdisc tcm_handle is not expected |
| * to exist, so that we choose create/graft too. |
| * |
| * 3. The last case is when no flags are set. |
| * Alas, it is sort of hole in API, we |
| * cannot decide what to do unambiguously. |
| * For now we select create/graft, if |
| * user gave KIND, which does not match existing. |
| */ |
| if ((n->nlmsg_flags&NLM_F_CREATE) && |
| (n->nlmsg_flags&NLM_F_REPLACE) && |
| ((n->nlmsg_flags&NLM_F_EXCL) || |
| (tca[TCA_KIND-1] && |
| rtattr_strcmp(tca[TCA_KIND-1], q->ops->id)))) |
| goto create_n_graft; |
| } |
| } |
| } else { |
| if (!tcm->tcm_handle) |
| return -EINVAL; |
| q = qdisc_lookup(dev, tcm->tcm_handle); |
| } |
| |
| /* Change qdisc parameters */ |
| if (q == NULL) |
| return -ENOENT; |
| if (n->nlmsg_flags&NLM_F_EXCL) |
| return -EEXIST; |
| if (tca[TCA_KIND-1] && rtattr_strcmp(tca[TCA_KIND-1], q->ops->id)) |
| return -EINVAL; |
| err = qdisc_change(q, tca); |
| if (err == 0) |
| qdisc_notify(skb, n, clid, NULL, q); |
| return err; |
| |
| create_n_graft: |
| if (!(n->nlmsg_flags&NLM_F_CREATE)) |
| return -ENOENT; |
| if (clid == TC_H_INGRESS) |
| q = qdisc_create(dev, tcm->tcm_parent, tcm->tcm_parent, |
| tca, &err); |
| else |
| q = qdisc_create(dev, tcm->tcm_parent, tcm->tcm_handle, |
| tca, &err); |
| if (q == NULL) { |
| if (err == -EAGAIN) |
| goto replay; |
| return err; |
| } |
| |
| graft: |
| if (1) { |
| struct Qdisc *old_q = NULL; |
| err = qdisc_graft(dev, p, clid, q, &old_q); |
| if (err) { |
| if (q) { |
| qdisc_lock_tree(dev); |
| qdisc_destroy(q); |
| qdisc_unlock_tree(dev); |
| } |
| return err; |
| } |
| qdisc_notify(skb, n, clid, old_q, q); |
| if (old_q) { |
| qdisc_lock_tree(dev); |
| qdisc_destroy(old_q); |
| qdisc_unlock_tree(dev); |
| } |
| } |
| return 0; |
| } |
| |
| static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid, |
| u32 pid, u32 seq, u16 flags, int event) |
| { |
| struct tcmsg *tcm; |
| struct nlmsghdr *nlh; |
| unsigned char *b = skb_tail_pointer(skb); |
| struct gnet_dump d; |
| |
| nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags); |
| tcm = NLMSG_DATA(nlh); |
| tcm->tcm_family = AF_UNSPEC; |
| tcm->tcm__pad1 = 0; |
| tcm->tcm__pad2 = 0; |
| tcm->tcm_ifindex = q->dev->ifindex; |
| tcm->tcm_parent = clid; |
| tcm->tcm_handle = q->handle; |
| tcm->tcm_info = atomic_read(&q->refcnt); |
| RTA_PUT(skb, TCA_KIND, IFNAMSIZ, q->ops->id); |
| if (q->ops->dump && q->ops->dump(q, skb) < 0) |
| goto rtattr_failure; |
| q->qstats.qlen = q->q.qlen; |
| |
| if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, |
| TCA_XSTATS, q->stats_lock, &d) < 0) |
| goto rtattr_failure; |
| |
| if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0) |
| goto rtattr_failure; |
| |
| if (gnet_stats_copy_basic(&d, &q->bstats) < 0 || |
| gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 || |
| gnet_stats_copy_queue(&d, &q->qstats) < 0) |
| goto rtattr_failure; |
| |
| if (gnet_stats_finish_copy(&d) < 0) |
| goto rtattr_failure; |
| |
| nlh->nlmsg_len = skb_tail_pointer(skb) - b; |
| return skb->len; |
| |
| nlmsg_failure: |
| rtattr_failure: |
| nlmsg_trim(skb, b); |
| return -1; |
| } |
| |
| static int qdisc_notify(struct sk_buff *oskb, struct nlmsghdr *n, |
| u32 clid, struct Qdisc *old, struct Qdisc *new) |
| { |
| struct sk_buff *skb; |
| u32 pid = oskb ? NETLINK_CB(oskb).pid : 0; |
| |
| skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); |
| if (!skb) |
| return -ENOBUFS; |
| |
| if (old && old->handle) { |
| if (tc_fill_qdisc(skb, old, clid, pid, n->nlmsg_seq, 0, RTM_DELQDISC) < 0) |
| goto err_out; |
| } |
| if (new) { |
| if (tc_fill_qdisc(skb, new, clid, pid, n->nlmsg_seq, old ? NLM_F_REPLACE : 0, RTM_NEWQDISC) < 0) |
| goto err_out; |
| } |
| |
| if (skb->len) |
| return rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO); |
| |
| err_out: |
| kfree_skb(skb); |
| return -EINVAL; |
| } |
| |
| static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb) |
| { |
| struct net *net = skb->sk->sk_net; |
| int idx, q_idx; |
| int s_idx, s_q_idx; |
| struct net_device *dev; |
| struct Qdisc *q; |
| |
| if (net != &init_net) |
| return 0; |
| |
| s_idx = cb->args[0]; |
| s_q_idx = q_idx = cb->args[1]; |
| read_lock(&dev_base_lock); |
| idx = 0; |
| for_each_netdev(&init_net, dev) { |
| if (idx < s_idx) |
| goto cont; |
| if (idx > s_idx) |
| s_q_idx = 0; |
| q_idx = 0; |
| list_for_each_entry(q, &dev->qdisc_list, list) { |
| if (q_idx < s_q_idx) { |
| q_idx++; |
| continue; |
| } |
| if (tc_fill_qdisc(skb, q, q->parent, NETLINK_CB(cb->skb).pid, |
| cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWQDISC) <= 0) |
| goto done; |
| q_idx++; |
| } |
| cont: |
| idx++; |
| } |
| |
| done: |
| read_unlock(&dev_base_lock); |
| |
| cb->args[0] = idx; |
| cb->args[1] = q_idx; |
| |
| return skb->len; |
| } |
| |
| |
| |
| /************************************************ |
| * Traffic classes manipulation. * |
| ************************************************/ |
| |
| |
| |
| static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n, void *arg) |
| { |
| struct net *net = skb->sk->sk_net; |
| struct tcmsg *tcm = NLMSG_DATA(n); |
| struct rtattr **tca = arg; |
| struct net_device *dev; |
| struct Qdisc *q = NULL; |
| const struct Qdisc_class_ops *cops; |
| unsigned long cl = 0; |
| unsigned long new_cl; |
| u32 pid = tcm->tcm_parent; |
| u32 clid = tcm->tcm_handle; |
| u32 qid = TC_H_MAJ(clid); |
| int err; |
| |
| if (net != &init_net) |
| return -EINVAL; |
| |
| if ((dev = __dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL) |
| return -ENODEV; |
| |
| /* |
| parent == TC_H_UNSPEC - unspecified parent. |
| parent == TC_H_ROOT - class is root, which has no parent. |
| parent == X:0 - parent is root class. |
| parent == X:Y - parent is a node in hierarchy. |
| parent == 0:Y - parent is X:Y, where X:0 is qdisc. |
| |
| handle == 0:0 - generate handle from kernel pool. |
| handle == 0:Y - class is X:Y, where X:0 is qdisc. |
| handle == X:Y - clear. |
| handle == X:0 - root class. |
| */ |
| |
| /* Step 1. Determine qdisc handle X:0 */ |
| |
| if (pid != TC_H_ROOT) { |
| u32 qid1 = TC_H_MAJ(pid); |
| |
| if (qid && qid1) { |
| /* If both majors are known, they must be identical. */ |
| if (qid != qid1) |
| return -EINVAL; |
| } else if (qid1) { |
| qid = qid1; |
| } else if (qid == 0) |
| qid = dev->qdisc_sleeping->handle; |
| |
| /* Now qid is genuine qdisc handle consistent |
| both with parent and child. |
| |
| TC_H_MAJ(pid) still may be unspecified, complete it now. |
| */ |
| if (pid) |
| pid = TC_H_MAKE(qid, pid); |
| } else { |
| if (qid == 0) |
| qid = dev->qdisc_sleeping->handle; |
| } |
| |
| /* OK. Locate qdisc */ |
| if ((q = qdisc_lookup(dev, qid)) == NULL) |
| return -ENOENT; |
| |
| /* An check that it supports classes */ |
| cops = q->ops->cl_ops; |
| if (cops == NULL) |
| return -EINVAL; |
| |
| /* Now try to get class */ |
| if (clid == 0) { |
| if (pid == TC_H_ROOT) |
| clid = qid; |
| } else |
| clid = TC_H_MAKE(qid, clid); |
| |
| if (clid) |
| cl = cops->get(q, clid); |
| |
| if (cl == 0) { |
| err = -ENOENT; |
| if (n->nlmsg_type != RTM_NEWTCLASS || !(n->nlmsg_flags&NLM_F_CREATE)) |
| goto out; |
| } else { |
| switch (n->nlmsg_type) { |
| case RTM_NEWTCLASS: |
| err = -EEXIST; |
| if (n->nlmsg_flags&NLM_F_EXCL) |
| goto out; |
| break; |
| case RTM_DELTCLASS: |
| err = cops->delete(q, cl); |
| if (err == 0) |
| tclass_notify(skb, n, q, cl, RTM_DELTCLASS); |
| goto out; |
| case RTM_GETTCLASS: |
| err = tclass_notify(skb, n, q, cl, RTM_NEWTCLASS); |
| goto out; |
| default: |
| err = -EINVAL; |
| goto out; |
| } |
| } |
| |
| new_cl = cl; |
| err = cops->change(q, clid, pid, tca, &new_cl); |
| if (err == 0) |
| tclass_notify(skb, n, q, new_cl, RTM_NEWTCLASS); |
| |
| out: |
| if (cl) |
| cops->put(q, cl); |
| |
| return err; |
| } |
| |
| |
| static int tc_fill_tclass(struct sk_buff *skb, struct Qdisc *q, |
| unsigned long cl, |
| u32 pid, u32 seq, u16 flags, int event) |
| { |
| struct tcmsg *tcm; |
| struct nlmsghdr *nlh; |
| unsigned char *b = skb_tail_pointer(skb); |
| struct gnet_dump d; |
| const struct Qdisc_class_ops *cl_ops = q->ops->cl_ops; |
| |
| nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags); |
| tcm = NLMSG_DATA(nlh); |
| tcm->tcm_family = AF_UNSPEC; |
| tcm->tcm_ifindex = q->dev->ifindex; |
| tcm->tcm_parent = q->handle; |
| tcm->tcm_handle = q->handle; |
| tcm->tcm_info = 0; |
| RTA_PUT(skb, TCA_KIND, IFNAMSIZ, q->ops->id); |
| if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0) |
| goto rtattr_failure; |
| |
| if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, |
| TCA_XSTATS, q->stats_lock, &d) < 0) |
| goto rtattr_failure; |
| |
| if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0) |
| goto rtattr_failure; |
| |
| if (gnet_stats_finish_copy(&d) < 0) |
| goto rtattr_failure; |
| |
| nlh->nlmsg_len = skb_tail_pointer(skb) - b; |
| return skb->len; |
| |
| nlmsg_failure: |
| rtattr_failure: |
| nlmsg_trim(skb, b); |
| return -1; |
| } |
| |
| static int tclass_notify(struct sk_buff *oskb, struct nlmsghdr *n, |
| struct Qdisc *q, unsigned long cl, int event) |
| { |
| struct sk_buff *skb; |
| u32 pid = oskb ? NETLINK_CB(oskb).pid : 0; |
| |
| skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); |
| if (!skb) |
| return -ENOBUFS; |
| |
| if (tc_fill_tclass(skb, q, cl, pid, n->nlmsg_seq, 0, event) < 0) { |
| kfree_skb(skb); |
| return -EINVAL; |
| } |
| |
| return rtnetlink_send(skb, &init_net, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO); |
| } |
| |
| struct qdisc_dump_args |
| { |
| struct qdisc_walker w; |
| struct sk_buff *skb; |
| struct netlink_callback *cb; |
| }; |
| |
| static int qdisc_class_dump(struct Qdisc *q, unsigned long cl, struct qdisc_walker *arg) |
| { |
| struct qdisc_dump_args *a = (struct qdisc_dump_args *)arg; |
| |
| return tc_fill_tclass(a->skb, q, cl, NETLINK_CB(a->cb->skb).pid, |
| a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTCLASS); |
| } |
| |
| static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb) |
| { |
| struct net *net = skb->sk->sk_net; |
| int t; |
| int s_t; |
| struct net_device *dev; |
| struct Qdisc *q; |
| struct tcmsg *tcm = (struct tcmsg*)NLMSG_DATA(cb->nlh); |
| struct qdisc_dump_args arg; |
| |
| if (net != &init_net) |
| return 0; |
| |
| if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm))) |
| return 0; |
| if ((dev = dev_get_by_index(&init_net, tcm->tcm_ifindex)) == NULL) |
| return 0; |
| |
| s_t = cb->args[0]; |
| t = 0; |
| |
| list_for_each_entry(q, &dev->qdisc_list, list) { |
| if (t < s_t || !q->ops->cl_ops || |
| (tcm->tcm_parent && |
| TC_H_MAJ(tcm->tcm_parent) != q->handle)) { |
| t++; |
| continue; |
| } |
| if (t > s_t) |
| memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0])); |
| arg.w.fn = qdisc_class_dump; |
| arg.skb = skb; |
| arg.cb = cb; |
| arg.w.stop = 0; |
| arg.w.skip = cb->args[1]; |
| arg.w.count = 0; |
| q->ops->cl_ops->walk(q, &arg.w); |
| cb->args[1] = arg.w.count; |
| if (arg.w.stop) |
| break; |
| t++; |
| } |
| |
| cb->args[0] = t; |
| |
| dev_put(dev); |
| return skb->len; |
| } |
| |
| /* Main classifier routine: scans classifier chain attached |
| to this qdisc, (optionally) tests for protocol and asks |
| specific classifiers. |
| */ |
| int tc_classify_compat(struct sk_buff *skb, struct tcf_proto *tp, |
| struct tcf_result *res) |
| { |
| __be16 protocol = skb->protocol; |
| int err = 0; |
| |
| for (; tp; tp = tp->next) { |
| if ((tp->protocol == protocol || |
| tp->protocol == htons(ETH_P_ALL)) && |
| (err = tp->classify(skb, tp, res)) >= 0) { |
| #ifdef CONFIG_NET_CLS_ACT |
| if (err != TC_ACT_RECLASSIFY && skb->tc_verd) |
| skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0); |
| #endif |
| return err; |
| } |
| } |
| return -1; |
| } |
| EXPORT_SYMBOL(tc_classify_compat); |
| |
| int tc_classify(struct sk_buff *skb, struct tcf_proto *tp, |
| struct tcf_result *res) |
| { |
| int err = 0; |
| __be16 protocol; |
| #ifdef CONFIG_NET_CLS_ACT |
| struct tcf_proto *otp = tp; |
| reclassify: |
| #endif |
| protocol = skb->protocol; |
| |
| err = tc_classify_compat(skb, tp, res); |
| #ifdef CONFIG_NET_CLS_ACT |
| if (err == TC_ACT_RECLASSIFY) { |
| u32 verd = G_TC_VERD(skb->tc_verd); |
| tp = otp; |
| |
| if (verd++ >= MAX_REC_LOOP) { |
| printk("rule prio %u protocol %02x reclassify loop, " |
| "packet dropped\n", |
| tp->prio&0xffff, ntohs(tp->protocol)); |
| return TC_ACT_SHOT; |
| } |
| skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd); |
| goto reclassify; |
| } |
| #endif |
| return err; |
| } |
| EXPORT_SYMBOL(tc_classify); |
| |
| void tcf_destroy(struct tcf_proto *tp) |
| { |
| tp->ops->destroy(tp); |
| module_put(tp->ops->owner); |
| kfree(tp); |
| } |
| |
| void tcf_destroy_chain(struct tcf_proto *fl) |
| { |
| struct tcf_proto *tp; |
| |
| while ((tp = fl) != NULL) { |
| fl = tp->next; |
| tcf_destroy(tp); |
| } |
| } |
| EXPORT_SYMBOL(tcf_destroy_chain); |
| |
| #ifdef CONFIG_PROC_FS |
| static int psched_show(struct seq_file *seq, void *v) |
| { |
| struct timespec ts; |
| |
| hrtimer_get_res(CLOCK_MONOTONIC, &ts); |
| seq_printf(seq, "%08x %08x %08x %08x\n", |
| (u32)NSEC_PER_USEC, (u32)PSCHED_US2NS(1), |
| 1000000, |
| (u32)NSEC_PER_SEC/(u32)ktime_to_ns(timespec_to_ktime(ts))); |
| |
| return 0; |
| } |
| |
| static int psched_open(struct inode *inode, struct file *file) |
| { |
| return single_open(file, psched_show, PDE(inode)->data); |
| } |
| |
| static const struct file_operations psched_fops = { |
| .owner = THIS_MODULE, |
| .open = psched_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = single_release, |
| }; |
| #endif |
| |
| static int __init pktsched_init(void) |
| { |
| register_qdisc(&pfifo_qdisc_ops); |
| register_qdisc(&bfifo_qdisc_ops); |
| proc_net_fops_create(&init_net, "psched", 0, &psched_fops); |
| |
| rtnl_register(PF_UNSPEC, RTM_NEWQDISC, tc_modify_qdisc, NULL); |
| rtnl_register(PF_UNSPEC, RTM_DELQDISC, tc_get_qdisc, NULL); |
| rtnl_register(PF_UNSPEC, RTM_GETQDISC, tc_get_qdisc, tc_dump_qdisc); |
| rtnl_register(PF_UNSPEC, RTM_NEWTCLASS, tc_ctl_tclass, NULL); |
| rtnl_register(PF_UNSPEC, RTM_DELTCLASS, tc_ctl_tclass, NULL); |
| rtnl_register(PF_UNSPEC, RTM_GETTCLASS, tc_ctl_tclass, tc_dump_tclass); |
| |
| return 0; |
| } |
| |
| subsys_initcall(pktsched_init); |