diff options
Diffstat (limited to 'net/sched/cls_api.c')
-rw-r--r-- | net/sched/cls_api.c | 642 |
1 files changed, 642 insertions, 0 deletions
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c new file mode 100644 index 0000000..56e66c3 --- /dev/null +++ b/net/sched/cls_api.c @@ -0,0 +1,642 @@ +/* + * net/sched/cls_api.c Packet classifier 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> + * + * Changes: + * + * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support + * + */ + +#include <asm/uaccess.h> +#include <asm/system.h> +#include <linux/bitops.h> +#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/kmod.h> +#include <net/sock.h> +#include <net/pkt_sched.h> +#include <net/pkt_cls.h> + +#if 0 /* control */ +#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args) +#else +#define DPRINTK(format,args...) +#endif + +/* The list of all installed classifier types */ + +static struct tcf_proto_ops *tcf_proto_base; + +/* Protects list of registered TC modules. It is pure SMP lock. */ +static DEFINE_RWLOCK(cls_mod_lock); + +/* Find classifier type by string name */ + +static struct tcf_proto_ops * tcf_proto_lookup_ops(struct rtattr *kind) +{ + struct tcf_proto_ops *t = NULL; + + if (kind) { + read_lock(&cls_mod_lock); + for (t = tcf_proto_base; t; t = t->next) { + if (rtattr_strcmp(kind, t->kind) == 0) { + if (!try_module_get(t->owner)) + t = NULL; + break; + } + } + read_unlock(&cls_mod_lock); + } + return t; +} + +/* Register(unregister) new classifier type */ + +int register_tcf_proto_ops(struct tcf_proto_ops *ops) +{ + struct tcf_proto_ops *t, **tp; + int rc = -EEXIST; + + write_lock(&cls_mod_lock); + for (tp = &tcf_proto_base; (t = *tp) != NULL; tp = &t->next) + if (!strcmp(ops->kind, t->kind)) + goto out; + + ops->next = NULL; + *tp = ops; + rc = 0; +out: + write_unlock(&cls_mod_lock); + return rc; +} + +int unregister_tcf_proto_ops(struct tcf_proto_ops *ops) +{ + struct tcf_proto_ops *t, **tp; + int rc = -ENOENT; + + write_lock(&cls_mod_lock); + for (tp = &tcf_proto_base; (t=*tp) != NULL; tp = &t->next) + if (t == ops) + break; + + if (!t) + goto out; + *tp = t->next; + rc = 0; +out: + write_unlock(&cls_mod_lock); + return rc; +} + +static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n, + struct tcf_proto *tp, unsigned long fh, int event); + + +/* Select new prio value from the range, managed by kernel. */ + +static __inline__ u32 tcf_auto_prio(struct tcf_proto *tp) +{ + u32 first = TC_H_MAKE(0xC0000000U,0U); + + if (tp) + first = tp->prio-1; + + return first; +} + +/* Add/change/delete/get a filter node */ + +static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg) +{ + struct rtattr **tca; + struct tcmsg *t; + u32 protocol; + u32 prio; + u32 nprio; + u32 parent; + struct net_device *dev; + struct Qdisc *q; + struct tcf_proto **back, **chain; + struct tcf_proto *tp; + struct tcf_proto_ops *tp_ops; + struct Qdisc_class_ops *cops; + unsigned long cl; + unsigned long fh; + int err; + +replay: + tca = arg; + t = NLMSG_DATA(n); + protocol = TC_H_MIN(t->tcm_info); + prio = TC_H_MAJ(t->tcm_info); + nprio = prio; + parent = t->tcm_parent; + cl = 0; + + if (prio == 0) { + /* If no priority is given, user wants we allocated it. */ + if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE)) + return -ENOENT; + prio = TC_H_MAKE(0x80000000U,0U); + } + + /* Find head of filter chain. */ + + /* Find link */ + if ((dev = __dev_get_by_index(t->tcm_ifindex)) == NULL) + return -ENODEV; + + /* Find qdisc */ + if (!parent) { + q = dev->qdisc_sleeping; + parent = q->handle; + } else if ((q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent))) == NULL) + return -EINVAL; + + /* Is it classful? */ + if ((cops = q->ops->cl_ops) == NULL) + return -EINVAL; + + /* Do we search for filter, attached to class? */ + if (TC_H_MIN(parent)) { + cl = cops->get(q, parent); + if (cl == 0) + return -ENOENT; + } + + /* And the last stroke */ + chain = cops->tcf_chain(q, cl); + err = -EINVAL; + if (chain == NULL) + goto errout; + + /* Check the chain for existence of proto-tcf with this priority */ + for (back = chain; (tp=*back) != NULL; back = &tp->next) { + if (tp->prio >= prio) { + if (tp->prio == prio) { + if (!nprio || (tp->protocol != protocol && protocol)) + goto errout; + } else + tp = NULL; + break; + } + } + + if (tp == NULL) { + /* Proto-tcf does not exist, create new one */ + + if (tca[TCA_KIND-1] == NULL || !protocol) + goto errout; + + err = -ENOENT; + if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE)) + goto errout; + + + /* Create new proto tcf */ + + err = -ENOBUFS; + if ((tp = kmalloc(sizeof(*tp), GFP_KERNEL)) == NULL) + goto errout; + err = -EINVAL; + tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND-1]); + if (tp_ops == NULL) { +#ifdef CONFIG_KMOD + struct rtattr *kind = tca[TCA_KIND-1]; + char name[IFNAMSIZ]; + + if (kind != NULL && + rtattr_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) { + rtnl_unlock(); + request_module("cls_%s", name); + rtnl_lock(); + tp_ops = tcf_proto_lookup_ops(kind); + /* We dropped the RTNL semaphore in order to + * perform the module load. So, even if we + * succeeded in loading the module we have to + * replay the request. We indicate this using + * -EAGAIN. + */ + if (tp_ops != NULL) { + module_put(tp_ops->owner); + err = -EAGAIN; + } + } +#endif + kfree(tp); + goto errout; + } + memset(tp, 0, sizeof(*tp)); + tp->ops = tp_ops; + tp->protocol = protocol; + tp->prio = nprio ? : tcf_auto_prio(*back); + tp->q = q; + tp->classify = tp_ops->classify; + tp->classid = parent; + if ((err = tp_ops->init(tp)) != 0) { + module_put(tp_ops->owner); + kfree(tp); + goto errout; + } + + qdisc_lock_tree(dev); + tp->next = *back; + *back = tp; + qdisc_unlock_tree(dev); + + } else if (tca[TCA_KIND-1] && rtattr_strcmp(tca[TCA_KIND-1], tp->ops->kind)) + goto errout; + + fh = tp->ops->get(tp, t->tcm_handle); + + if (fh == 0) { + if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) { + qdisc_lock_tree(dev); + *back = tp->next; + qdisc_unlock_tree(dev); + + tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER); + tcf_destroy(tp); + err = 0; + goto errout; + } + + err = -ENOENT; + if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE)) + goto errout; + } else { + switch (n->nlmsg_type) { + case RTM_NEWTFILTER: + err = -EEXIST; + if (n->nlmsg_flags&NLM_F_EXCL) + goto errout; + break; + case RTM_DELTFILTER: + err = tp->ops->delete(tp, fh); + if (err == 0) + tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER); + goto errout; + case RTM_GETTFILTER: + err = tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER); + goto errout; + default: + err = -EINVAL; + goto errout; + } + } + + err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh); + if (err == 0) + tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER); + +errout: + if (cl) + cops->put(q, cl); + if (err == -EAGAIN) + /* Replay the request. */ + goto replay; + return err; +} + +static int +tcf_fill_node(struct sk_buff *skb, struct tcf_proto *tp, unsigned long fh, + u32 pid, u32 seq, unsigned flags, int event) +{ + struct tcmsg *tcm; + struct nlmsghdr *nlh; + unsigned char *b = skb->tail; + + 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 = tp->q->dev->ifindex; + tcm->tcm_parent = tp->classid; + tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol); + RTA_PUT(skb, TCA_KIND, IFNAMSIZ, tp->ops->kind); + tcm->tcm_handle = fh; + if (RTM_DELTFILTER != event) { + tcm->tcm_handle = 0; + if (tp->ops->dump && tp->ops->dump(tp, fh, skb, tcm) < 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 tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n, + struct tcf_proto *tp, unsigned long fh, 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 (tcf_fill_node(skb, tp, fh, 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 tcf_dump_args +{ + struct tcf_walker w; + struct sk_buff *skb; + struct netlink_callback *cb; +}; + +static int tcf_node_dump(struct tcf_proto *tp, unsigned long n, struct tcf_walker *arg) +{ + struct tcf_dump_args *a = (void*)arg; + + return tcf_fill_node(a->skb, tp, n, NETLINK_CB(a->cb->skb).pid, + a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER); +} + +static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) +{ + int t; + int s_t; + struct net_device *dev; + struct Qdisc *q; + struct tcf_proto *tp, **chain; + struct tcmsg *tcm = (struct tcmsg*)NLMSG_DATA(cb->nlh); + unsigned long cl = 0; + struct Qdisc_class_ops *cops; + struct tcf_dump_args arg; + + if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm))) + return skb->len; + if ((dev = dev_get_by_index(tcm->tcm_ifindex)) == NULL) + return skb->len; + + read_lock_bh(&qdisc_tree_lock); + if (!tcm->tcm_parent) + q = dev->qdisc_sleeping; + else + q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent)); + if (!q) + goto out; + if ((cops = q->ops->cl_ops) == NULL) + goto errout; + if (TC_H_MIN(tcm->tcm_parent)) { + cl = cops->get(q, tcm->tcm_parent); + if (cl == 0) + goto errout; + } + chain = cops->tcf_chain(q, cl); + if (chain == NULL) + goto errout; + + s_t = cb->args[0]; + + for (tp=*chain, t=0; tp; tp = tp->next, t++) { + if (t < s_t) continue; + if (TC_H_MAJ(tcm->tcm_info) && + TC_H_MAJ(tcm->tcm_info) != tp->prio) + continue; + if (TC_H_MIN(tcm->tcm_info) && + TC_H_MIN(tcm->tcm_info) != tp->protocol) + continue; + if (t > s_t) + memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0])); + if (cb->args[1] == 0) { + if (tcf_fill_node(skb, tp, 0, NETLINK_CB(cb->skb).pid, + cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER) <= 0) { + break; + } + cb->args[1] = 1; + } + if (tp->ops->walk == NULL) + continue; + arg.w.fn = tcf_node_dump; + arg.skb = skb; + arg.cb = cb; + arg.w.stop = 0; + arg.w.skip = cb->args[1]-1; + arg.w.count = 0; + tp->ops->walk(tp, &arg.w); + cb->args[1] = arg.w.count+1; + if (arg.w.stop) + break; + } + + cb->args[0] = t; + +errout: + if (cl) + cops->put(q, cl); +out: + read_unlock_bh(&qdisc_tree_lock); + dev_put(dev); + return skb->len; +} + +void +tcf_exts_destroy(struct tcf_proto *tp, struct tcf_exts *exts) +{ +#ifdef CONFIG_NET_CLS_ACT + if (exts->action) { + tcf_action_destroy(exts->action, TCA_ACT_UNBIND); + exts->action = NULL; + } +#elif defined CONFIG_NET_CLS_POLICE + if (exts->police) { + tcf_police_release(exts->police, TCA_ACT_UNBIND); + exts->police = NULL; + } +#endif +} + + +int +tcf_exts_validate(struct tcf_proto *tp, struct rtattr **tb, + struct rtattr *rate_tlv, struct tcf_exts *exts, + struct tcf_ext_map *map) +{ + memset(exts, 0, sizeof(*exts)); + +#ifdef CONFIG_NET_CLS_ACT + { + int err; + struct tc_action *act; + + if (map->police && tb[map->police-1]) { + act = tcf_action_init_1(tb[map->police-1], rate_tlv, "police", + TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err); + if (act == NULL) + return err; + + act->type = TCA_OLD_COMPAT; + exts->action = act; + } else if (map->action && tb[map->action-1]) { + act = tcf_action_init(tb[map->action-1], rate_tlv, NULL, + TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err); + if (act == NULL) + return err; + + exts->action = act; + } + } +#elif defined CONFIG_NET_CLS_POLICE + if (map->police && tb[map->police-1]) { + struct tcf_police *p; + + p = tcf_police_locate(tb[map->police-1], rate_tlv); + if (p == NULL) + return -EINVAL; + + exts->police = p; + } else if (map->action && tb[map->action-1]) + return -EOPNOTSUPP; +#else + if ((map->action && tb[map->action-1]) || + (map->police && tb[map->police-1])) + return -EOPNOTSUPP; +#endif + + return 0; +} + +void +tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst, + struct tcf_exts *src) +{ +#ifdef CONFIG_NET_CLS_ACT + if (src->action) { + struct tc_action *act; + tcf_tree_lock(tp); + act = xchg(&dst->action, src->action); + tcf_tree_unlock(tp); + if (act) + tcf_action_destroy(act, TCA_ACT_UNBIND); + } +#elif defined CONFIG_NET_CLS_POLICE + if (src->police) { + struct tcf_police *p; + tcf_tree_lock(tp); + p = xchg(&dst->police, src->police); + tcf_tree_unlock(tp); + if (p) + tcf_police_release(p, TCA_ACT_UNBIND); + } +#endif +} + +int +tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts, + struct tcf_ext_map *map) +{ +#ifdef CONFIG_NET_CLS_ACT + if (map->action && exts->action) { + /* + * again for backward compatible mode - we want + * to work with both old and new modes of entering + * tc data even if iproute2 was newer - jhs + */ + struct rtattr * p_rta = (struct rtattr*) skb->tail; + + if (exts->action->type != TCA_OLD_COMPAT) { + RTA_PUT(skb, map->action, 0, NULL); + if (tcf_action_dump(skb, exts->action, 0, 0) < 0) + goto rtattr_failure; + p_rta->rta_len = skb->tail - (u8*)p_rta; + } else if (map->police) { + RTA_PUT(skb, map->police, 0, NULL); + if (tcf_action_dump_old(skb, exts->action, 0, 0) < 0) + goto rtattr_failure; + p_rta->rta_len = skb->tail - (u8*)p_rta; + } + } +#elif defined CONFIG_NET_CLS_POLICE + if (map->police && exts->police) { + struct rtattr * p_rta = (struct rtattr*) skb->tail; + + RTA_PUT(skb, map->police, 0, NULL); + + if (tcf_police_dump(skb, exts->police) < 0) + goto rtattr_failure; + + p_rta->rta_len = skb->tail - (u8*)p_rta; + } +#endif + return 0; +rtattr_failure: __attribute__ ((unused)) + return -1; +} + +int +tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts, + struct tcf_ext_map *map) +{ +#ifdef CONFIG_NET_CLS_ACT + if (exts->action) + if (tcf_action_copy_stats(skb, exts->action, 1) < 0) + goto rtattr_failure; +#elif defined CONFIG_NET_CLS_POLICE + if (exts->police) + if (tcf_police_dump_stats(skb, exts->police) < 0) + goto rtattr_failure; +#endif + return 0; +rtattr_failure: __attribute__ ((unused)) + return -1; +} + +static int __init tc_filter_init(void) +{ + struct rtnetlink_link *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_NEWTFILTER-RTM_BASE].doit = tc_ctl_tfilter; + link_p[RTM_DELTFILTER-RTM_BASE].doit = tc_ctl_tfilter; + link_p[RTM_GETTFILTER-RTM_BASE].doit = tc_ctl_tfilter; + link_p[RTM_GETTFILTER-RTM_BASE].dumpit = tc_dump_tfilter; + } + return 0; +} + +subsys_initcall(tc_filter_init); + +EXPORT_SYMBOL(register_tcf_proto_ops); +EXPORT_SYMBOL(unregister_tcf_proto_ops); +EXPORT_SYMBOL(tcf_exts_validate); +EXPORT_SYMBOL(tcf_exts_destroy); +EXPORT_SYMBOL(tcf_exts_change); +EXPORT_SYMBOL(tcf_exts_dump); +EXPORT_SYMBOL(tcf_exts_dump_stats); |