/* * 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, u16 flags, int event) { struct tcmsg *tcm; struct nlmsghdr *nlh; unsigned char *b = skb->tail; nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), 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);