diff options
Diffstat (limited to 'net/sched/sch_api.c')
| -rw-r--r-- | net/sched/sch_api.c | 1296 |
1 files changed, 1296 insertions, 0 deletions
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c new file mode 100644 index 0000000..4323a74 --- /dev/null +++ b/net/sched/sch_api.c @@ -0,0 +1,1296 @@ +/* + * 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/config.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/in.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <linux/rtnetlink.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/bitops.h> + +#include <net/sock.h> +#include <net/pkt_sched.h> + +#include <asm/processor.h> +#include <asm/uaccess.h> +#include <asm/system.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; +} + +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; +} + +/* 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; + + read_lock_bh(&qdisc_tree_lock); + list_for_each_entry(q, &dev->qdisc_list, list) { + if (q->handle == handle) { + read_unlock_bh(&qdisc_tree_lock); + return q; + } + } + read_unlock_bh(&qdisc_tree_lock); + return NULL; +} + +static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid) +{ + unsigned long cl; + struct Qdisc *leaf; + 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; +} + +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; + } + } +} + + +/* 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; +} + + +/* 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 { + 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); + if (new) + new->parent = classid; + 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 handle, struct rtattr **tca, int *errp) +{ + int err; + struct rtattr *kind = tca[TCA_KIND-1]; + void *p = NULL; + struct Qdisc *sch; + struct Qdisc_ops *ops; + int size; + + 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 = -EINVAL; + if (ops == NULL) + goto err_out; + + /* ensure that the Qdisc and the private data are 32-byte aligned */ + size = ((sizeof(*sch) + QDISC_ALIGN_CONST) & ~QDISC_ALIGN_CONST); + size += ops->priv_size + QDISC_ALIGN_CONST; + + p = kmalloc(size, GFP_KERNEL); + err = -ENOBUFS; + if (!p) + goto err_out2; + memset(p, 0, size); + sch = (struct Qdisc *)(((unsigned long)p + QDISC_ALIGN_CONST) + & ~QDISC_ALIGN_CONST); + sch->padded = (char *)sch - (char *)p; + + INIT_LIST_HEAD(&sch->list); + skb_queue_head_init(&sch->q); + + if (handle == TC_H_INGRESS) + sch->flags |= TCQ_F_INGRESS; + + sch->ops = ops; + sch->enqueue = ops->enqueue; + sch->dequeue = ops->dequeue; + sch->dev = dev; + dev_hold(dev); + atomic_set(&sch->refcnt, 1); + sch->stats_lock = &dev->queue_lock; + if (handle == 0) { + handle = qdisc_alloc_handle(dev); + err = -ENOMEM; + if (handle == 0) + goto err_out3; + } + + if (handle == TC_H_INGRESS) + sch->handle =TC_H_MAKE(TC_H_INGRESS, 0); + else + sch->handle = handle; + + if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS-1])) == 0) { + qdisc_lock_tree(dev); + list_add_tail(&sch->list, &dev->qdisc_list); + qdisc_unlock_tree(dev); + +#ifdef CONFIG_NET_ESTIMATOR + if (tca[TCA_RATE-1]) + gen_new_estimator(&sch->bstats, &sch->rate_est, + sch->stats_lock, tca[TCA_RATE-1]); +#endif + return sch; + } +err_out3: + dev_put(dev); +err_out2: + module_put(ops->owner); +err_out: + *errp = err; + if (p) + kfree(p); + 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; + } +#ifdef CONFIG_NET_ESTIMATOR + if (tca[TCA_RATE-1]) + gen_replace_estimator(&sch->bstats, &sch->rate_est, + sch->stats_lock, tca[TCA_RATE-1]); +#endif + 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; + 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 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 ((dev = __dev_get_by_index(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); + spin_lock_bh(&dev->queue_lock); + qdisc_destroy(q); + spin_unlock_bh(&dev->queue_lock); + } + } 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 tcmsg *tcm; + struct rtattr **tca; + struct net_device *dev; + u32 clid; + struct Qdisc *q, *p; + int err; + +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(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, tca, &err); + else + q = qdisc_create(dev, 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) { + spin_lock_bh(&dev->queue_lock); + qdisc_destroy(q); + spin_unlock_bh(&dev->queue_lock); + } + return err; + } + qdisc_notify(skb, n, clid, old_q, q); + if (old_q) { + spin_lock_bh(&dev->queue_lock); + qdisc_destroy(old_q); + spin_unlock_bh(&dev->queue_lock); + } + } + return 0; +} + +static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid, + u32 pid, u32 seq, unsigned flags, int event) +{ + struct tcmsg *tcm; + struct nlmsghdr *nlh; + unsigned char *b = skb->tail; + struct gnet_dump d; + + nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*tcm)); + nlh->nlmsg_flags = flags; + tcm = NLMSG_DATA(nlh); + tcm->tcm_family = AF_UNSPEC; + 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 || +#ifdef CONFIG_NET_ESTIMATOR + gnet_stats_copy_rate_est(&d, &q->rate_est) < 0 || +#endif + 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 - b; + return skb->len; + +nlmsg_failure: +rtattr_failure: + skb_trim(skb, b - skb->data); + 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, pid, RTMGRP_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) +{ + int idx, q_idx; + int s_idx, s_q_idx; + struct net_device *dev; + struct Qdisc *q; + + s_idx = cb->args[0]; + s_q_idx = q_idx = cb->args[1]; + read_lock(&dev_base_lock); + for (dev=dev_base, idx=0; dev; dev = dev->next, idx++) { + if (idx < s_idx) + continue; + if (idx > s_idx) + s_q_idx = 0; + read_lock_bh(&qdisc_tree_lock); + 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) { + read_unlock_bh(&qdisc_tree_lock); + goto done; + } + q_idx++; + } + read_unlock_bh(&qdisc_tree_lock); + } + +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 tcmsg *tcm = NLMSG_DATA(n); + struct rtattr **tca = arg; + struct net_device *dev; + struct Qdisc *q = NULL; + 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 ((dev = __dev_get_by_index(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, unsigned flags, int event) +{ + struct tcmsg *tcm; + struct nlmsghdr *nlh; + unsigned char *b = skb->tail; + struct gnet_dump d; + struct Qdisc_class_ops *cl_ops = q->ops->cl_ops; + + nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*tcm)); + nlh->nlmsg_flags = 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 - b; + return skb->len; + +nlmsg_failure: +rtattr_failure: + skb_trim(skb, b - skb->data); + 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, pid, RTMGRP_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) +{ + 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 (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm))) + return 0; + if ((dev = dev_get_by_index(tcm->tcm_ifindex)) == NULL) + return 0; + + s_t = cb->args[0]; + t = 0; + + read_lock_bh(&qdisc_tree_lock); + 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++; + } + read_unlock_bh(&qdisc_tree_lock); + + 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(struct sk_buff *skb, struct tcf_proto *tp, + struct tcf_result *res) +{ + int err = 0; + u32 protocol = skb->protocol; +#ifdef CONFIG_NET_CLS_ACT + struct tcf_proto *otp = tp; +reclassify: +#endif + protocol = skb->protocol; + + for ( ; tp; tp = tp->next) { + if ((tp->protocol == protocol || + tp->protocol == __constant_htons(ETH_P_ALL)) && + (err = tp->classify(skb, tp, res)) >= 0) { +#ifdef CONFIG_NET_CLS_ACT + if ( TC_ACT_RECLASSIFY == err) { + __u32 verd = (__u32) G_TC_VERD(skb->tc_verd); + tp = otp; + + if (MAX_REC_LOOP < verd++) { + printk("rule prio %d protocol %02x reclassify is buggy 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; + } else { + if (skb->tc_verd) + skb->tc_verd = SET_TC_VERD(skb->tc_verd,0); + return err; + } +#else + + return err; +#endif + } + + } + return -1; +} + +static int psched_us_per_tick = 1; +static int psched_tick_per_us = 1; + +#ifdef CONFIG_PROC_FS +static int psched_show(struct seq_file *seq, void *v) +{ + seq_printf(seq, "%08x %08x %08x %08x\n", + psched_tick_per_us, psched_us_per_tick, + 1000000, HZ); + + return 0; +} + +static int psched_open(struct inode *inode, struct file *file) +{ + return single_open(file, psched_show, PDE(inode)->data); +} + +static struct file_operations psched_fops = { + .owner = THIS_MODULE, + .open = psched_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; +#endif + +#ifdef CONFIG_NET_SCH_CLK_CPU +psched_tdiff_t psched_clock_per_hz; +int psched_clock_scale; +EXPORT_SYMBOL(psched_clock_per_hz); +EXPORT_SYMBOL(psched_clock_scale); + +psched_time_t psched_time_base; +cycles_t psched_time_mark; +EXPORT_SYMBOL(psched_time_mark); +EXPORT_SYMBOL(psched_time_base); + +/* + * Periodically adjust psched_time_base to avoid overflow + * with 32-bit get_cycles(). Safe up to 4GHz CPU. + */ +static void psched_tick(unsigned long); +static struct timer_list psched_timer = TIMER_INITIALIZER(psched_tick, 0, 0); + +static void psched_tick(unsigned long dummy) +{ + if (sizeof(cycles_t) == sizeof(u32)) { + psched_time_t dummy_stamp; + PSCHED_GET_TIME(dummy_stamp); + psched_timer.expires = jiffies + 1*HZ; + add_timer(&psched_timer); + } +} + +int __init psched_calibrate_clock(void) +{ + psched_time_t stamp, stamp1; + struct timeval tv, tv1; + psched_tdiff_t delay; + long rdelay; + unsigned long stop; + + psched_tick(0); + stop = jiffies + HZ/10; + PSCHED_GET_TIME(stamp); + do_gettimeofday(&tv); + while (time_before(jiffies, stop)) { + barrier(); + cpu_relax(); + } + PSCHED_GET_TIME(stamp1); + do_gettimeofday(&tv1); + + delay = PSCHED_TDIFF(stamp1, stamp); + rdelay = tv1.tv_usec - tv.tv_usec; + rdelay += (tv1.tv_sec - tv.tv_sec)*1000000; + if (rdelay > delay) + return -1; + delay /= rdelay; + psched_tick_per_us = delay; + while ((delay>>=1) != 0) + psched_clock_scale++; + psched_us_per_tick = 1<<psched_clock_scale; + psched_clock_per_hz = (psched_tick_per_us*(1000000/HZ))>>psched_clock_scale; + return 0; +} +#endif + +static int __init pktsched_init(void) +{ + struct rtnetlink_link *link_p; + +#ifdef CONFIG_NET_SCH_CLK_CPU + if (psched_calibrate_clock() < 0) + return -1; +#elif defined(CONFIG_NET_SCH_CLK_JIFFIES) + psched_tick_per_us = HZ<<PSCHED_JSCALE; + psched_us_per_tick = 1000000; +#endif + + link_p = rtnetlink_links[PF_UNSPEC]; + + /* Setup rtnetlink links. It is made here to avoid + exporting large number of public symbols. + */ + + if (link_p) { + link_p[RTM_NEWQDISC-RTM_BASE].doit = tc_modify_qdisc; + link_p[RTM_DELQDISC-RTM_BASE].doit = tc_get_qdisc; + link_p[RTM_GETQDISC-RTM_BASE].doit = tc_get_qdisc; + link_p[RTM_GETQDISC-RTM_BASE].dumpit = tc_dump_qdisc; + link_p[RTM_NEWTCLASS-RTM_BASE].doit = tc_ctl_tclass; + link_p[RTM_DELTCLASS-RTM_BASE].doit = tc_ctl_tclass; + link_p[RTM_GETTCLASS-RTM_BASE].doit = tc_ctl_tclass; + link_p[RTM_GETTCLASS-RTM_BASE].dumpit = tc_dump_tclass; + } + + register_qdisc(&pfifo_qdisc_ops); + register_qdisc(&bfifo_qdisc_ops); + proc_net_fops_create("psched", 0, &psched_fops); + + return 0; +} + +subsys_initcall(pktsched_init); + +EXPORT_SYMBOL(qdisc_get_rtab); +EXPORT_SYMBOL(qdisc_put_rtab); +EXPORT_SYMBOL(register_qdisc); +EXPORT_SYMBOL(unregister_qdisc); +EXPORT_SYMBOL(tc_classify); |
