![WANG Cong](/assets/img/avatar_default.png)
struct tc_action is confusing, currently we use it for two purposes: 1) Pass in arguments and carry out results from helper functions 2) A generic representation for tc actions The first one is error-prone, since we need to make sure we don't miss anything. This patch aims to get rid of this use, by moving tc_action into tcf_common, so that they are allocated together in hashtable and can be cast'ed easily. And together with the following patch, we could really make tc_action a generic representation for all tc actions and each type of action can inherit from it. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
285 lines
6.6 KiB
C
285 lines
6.6 KiB
C
/*
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* net/sched/act_pedit.c Generic packet editor
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Authors: Jamal Hadi Salim (2002-4)
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/errno.h>
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#include <linux/skbuff.h>
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#include <linux/rtnetlink.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <net/netlink.h>
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#include <net/pkt_sched.h>
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#include <linux/tc_act/tc_pedit.h>
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#include <net/tc_act/tc_pedit.h>
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#define PEDIT_TAB_MASK 15
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static int pedit_net_id;
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static struct tc_action_ops act_pedit_ops;
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static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = {
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[TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) },
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};
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static int tcf_pedit_init(struct net *net, struct nlattr *nla,
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struct nlattr *est, struct tc_action **a,
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int ovr, int bind)
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{
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struct tc_action_net *tn = net_generic(net, pedit_net_id);
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struct nlattr *tb[TCA_PEDIT_MAX + 1];
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struct tc_pedit *parm;
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int ret = 0, err;
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struct tcf_pedit *p;
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struct tc_pedit_key *keys = NULL;
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int ksize;
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if (nla == NULL)
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return -EINVAL;
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err = nla_parse_nested(tb, TCA_PEDIT_MAX, nla, pedit_policy);
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if (err < 0)
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return err;
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if (tb[TCA_PEDIT_PARMS] == NULL)
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return -EINVAL;
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parm = nla_data(tb[TCA_PEDIT_PARMS]);
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ksize = parm->nkeys * sizeof(struct tc_pedit_key);
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if (nla_len(tb[TCA_PEDIT_PARMS]) < sizeof(*parm) + ksize)
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return -EINVAL;
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if (!tcf_hash_check(tn, parm->index, a, bind)) {
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if (!parm->nkeys)
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return -EINVAL;
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ret = tcf_hash_create(tn, parm->index, est, a,
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&act_pedit_ops, bind, false);
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if (ret)
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return ret;
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p = to_pedit(*a);
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keys = kmalloc(ksize, GFP_KERNEL);
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if (keys == NULL) {
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tcf_hash_cleanup(*a, est);
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return -ENOMEM;
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}
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ret = ACT_P_CREATED;
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} else {
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if (bind)
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return 0;
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tcf_hash_release(*a, bind);
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if (!ovr)
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return -EEXIST;
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p = to_pedit(*a);
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if (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys) {
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keys = kmalloc(ksize, GFP_KERNEL);
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if (keys == NULL)
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return -ENOMEM;
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}
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}
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spin_lock_bh(&p->tcf_lock);
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p->tcfp_flags = parm->flags;
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p->tcf_action = parm->action;
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if (keys) {
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kfree(p->tcfp_keys);
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p->tcfp_keys = keys;
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p->tcfp_nkeys = parm->nkeys;
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}
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memcpy(p->tcfp_keys, parm->keys, ksize);
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spin_unlock_bh(&p->tcf_lock);
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if (ret == ACT_P_CREATED)
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tcf_hash_insert(tn, *a);
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return ret;
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}
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static void tcf_pedit_cleanup(struct tc_action *a, int bind)
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{
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struct tcf_pedit *p = to_pedit(a);
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struct tc_pedit_key *keys = p->tcfp_keys;
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kfree(keys);
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}
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static int tcf_pedit(struct sk_buff *skb, const struct tc_action *a,
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struct tcf_result *res)
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{
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struct tcf_pedit *p = to_pedit(a);
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int i;
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unsigned int off;
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if (skb_unclone(skb, GFP_ATOMIC))
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return p->tcf_action;
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off = skb_network_offset(skb);
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spin_lock(&p->tcf_lock);
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tcf_lastuse_update(&p->tcf_tm);
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if (p->tcfp_nkeys > 0) {
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struct tc_pedit_key *tkey = p->tcfp_keys;
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for (i = p->tcfp_nkeys; i > 0; i--, tkey++) {
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u32 *ptr, _data;
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int offset = tkey->off;
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if (tkey->offmask) {
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char *d, _d;
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d = skb_header_pointer(skb, off + tkey->at, 1,
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&_d);
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if (!d)
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goto bad;
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offset += (*d & tkey->offmask) >> tkey->shift;
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}
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if (offset % 4) {
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pr_info("tc filter pedit"
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" offset must be on 32 bit boundaries\n");
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goto bad;
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}
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if (offset > 0 && offset > skb->len) {
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pr_info("tc filter pedit"
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" offset %d can't exceed pkt length %d\n",
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offset, skb->len);
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goto bad;
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}
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ptr = skb_header_pointer(skb, off + offset, 4, &_data);
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if (!ptr)
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goto bad;
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/* just do it, baby */
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*ptr = ((*ptr & tkey->mask) ^ tkey->val);
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if (ptr == &_data)
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skb_store_bits(skb, off + offset, ptr, 4);
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}
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goto done;
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} else
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WARN(1, "pedit BUG: index %d\n", p->tcf_index);
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bad:
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p->tcf_qstats.overlimits++;
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done:
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bstats_update(&p->tcf_bstats, skb);
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spin_unlock(&p->tcf_lock);
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return p->tcf_action;
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}
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static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a,
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int bind, int ref)
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{
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unsigned char *b = skb_tail_pointer(skb);
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struct tcf_pedit *p = to_pedit(a);
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struct tc_pedit *opt;
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struct tcf_t t;
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int s;
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s = sizeof(*opt) + p->tcfp_nkeys * sizeof(struct tc_pedit_key);
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/* netlink spinlocks held above us - must use ATOMIC */
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opt = kzalloc(s, GFP_ATOMIC);
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if (unlikely(!opt))
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return -ENOBUFS;
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memcpy(opt->keys, p->tcfp_keys,
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p->tcfp_nkeys * sizeof(struct tc_pedit_key));
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opt->index = p->tcf_index;
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opt->nkeys = p->tcfp_nkeys;
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opt->flags = p->tcfp_flags;
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opt->action = p->tcf_action;
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opt->refcnt = p->tcf_refcnt - ref;
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opt->bindcnt = p->tcf_bindcnt - bind;
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if (nla_put(skb, TCA_PEDIT_PARMS, s, opt))
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goto nla_put_failure;
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tcf_tm_dump(&t, &p->tcf_tm);
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if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD))
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goto nla_put_failure;
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kfree(opt);
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return skb->len;
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nla_put_failure:
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nlmsg_trim(skb, b);
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kfree(opt);
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return -1;
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}
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static int tcf_pedit_walker(struct net *net, struct sk_buff *skb,
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struct netlink_callback *cb, int type,
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const struct tc_action_ops *ops)
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{
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struct tc_action_net *tn = net_generic(net, pedit_net_id);
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return tcf_generic_walker(tn, skb, cb, type, ops);
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}
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static int tcf_pedit_search(struct net *net, struct tc_action **a, u32 index)
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{
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struct tc_action_net *tn = net_generic(net, pedit_net_id);
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return tcf_hash_search(tn, a, index);
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}
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static struct tc_action_ops act_pedit_ops = {
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.kind = "pedit",
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.type = TCA_ACT_PEDIT,
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.owner = THIS_MODULE,
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.act = tcf_pedit,
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.dump = tcf_pedit_dump,
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.cleanup = tcf_pedit_cleanup,
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.init = tcf_pedit_init,
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.walk = tcf_pedit_walker,
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.lookup = tcf_pedit_search,
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.size = sizeof(struct tcf_pedit),
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};
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static __net_init int pedit_init_net(struct net *net)
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{
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struct tc_action_net *tn = net_generic(net, pedit_net_id);
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return tc_action_net_init(tn, &act_pedit_ops, PEDIT_TAB_MASK);
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}
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static void __net_exit pedit_exit_net(struct net *net)
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{
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struct tc_action_net *tn = net_generic(net, pedit_net_id);
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tc_action_net_exit(tn);
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}
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static struct pernet_operations pedit_net_ops = {
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.init = pedit_init_net,
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.exit = pedit_exit_net,
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.id = &pedit_net_id,
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.size = sizeof(struct tc_action_net),
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};
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MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
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MODULE_DESCRIPTION("Generic Packet Editor actions");
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MODULE_LICENSE("GPL");
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static int __init pedit_init_module(void)
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{
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return tcf_register_action(&act_pedit_ops, &pedit_net_ops);
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}
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static void __exit pedit_cleanup_module(void)
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{
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tcf_unregister_action(&act_pedit_ops, &pedit_net_ops);
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}
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module_init(pedit_init_module);
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module_exit(pedit_cleanup_module);
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