![Arnaldo Carvalho de Melo](/assets/img/avatar_default.png)
So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes on 64bit architectures, allowing us to combine the 4 bytes hole left by the layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4 64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN... :-) Many calculations that previously required that skb->{transport,network, mac}_header be first converted to a pointer now can be done directly, being meaningful as offsets or pointers. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
212 lines
5 KiB
C
212 lines
5 KiB
C
/*
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* net/sched/simp.c Simple example of an action
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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 (2005)
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*
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/netdevice.h>
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#include <linux/skbuff.h>
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#include <linux/rtnetlink.h>
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#include <net/pkt_sched.h>
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#define TCA_ACT_SIMP 22
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#include <linux/tc_act/tc_defact.h>
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#include <net/tc_act/tc_defact.h>
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#define SIMP_TAB_MASK 7
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static struct tcf_common *tcf_simp_ht[SIMP_TAB_MASK + 1];
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static u32 simp_idx_gen;
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static DEFINE_RWLOCK(simp_lock);
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static struct tcf_hashinfo simp_hash_info = {
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.htab = tcf_simp_ht,
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.hmask = SIMP_TAB_MASK,
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.lock = &simp_lock,
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};
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static int tcf_simp(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
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{
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struct tcf_defact *d = a->priv;
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spin_lock(&d->tcf_lock);
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d->tcf_tm.lastuse = jiffies;
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d->tcf_bstats.bytes += skb->len;
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d->tcf_bstats.packets++;
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/* print policy string followed by _ then packet count
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* Example if this was the 3rd packet and the string was "hello"
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* then it would look like "hello_3" (without quotes)
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**/
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printk("simple: %s_%d\n",
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(char *)d->tcfd_defdata, d->tcf_bstats.packets);
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spin_unlock(&d->tcf_lock);
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return d->tcf_action;
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}
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static int tcf_simp_release(struct tcf_defact *d, int bind)
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{
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int ret = 0;
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if (d) {
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if (bind)
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d->tcf_bindcnt--;
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d->tcf_refcnt--;
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if (d->tcf_bindcnt <= 0 && d->tcf_refcnt <= 0) {
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kfree(d->tcfd_defdata);
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tcf_hash_destroy(&d->common, &simp_hash_info);
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ret = 1;
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}
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}
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return ret;
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}
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static int alloc_defdata(struct tcf_defact *d, u32 datalen, void *defdata)
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{
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d->tcfd_defdata = kmemdup(defdata, datalen, GFP_KERNEL);
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if (unlikely(!d->tcfd_defdata))
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return -ENOMEM;
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d->tcfd_datalen = datalen;
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return 0;
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}
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static int realloc_defdata(struct tcf_defact *d, u32 datalen, void *defdata)
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{
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kfree(d->tcfd_defdata);
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return alloc_defdata(d, datalen, defdata);
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}
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static int tcf_simp_init(struct rtattr *rta, struct rtattr *est,
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struct tc_action *a, int ovr, int bind)
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{
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struct rtattr *tb[TCA_DEF_MAX];
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struct tc_defact *parm;
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struct tcf_defact *d;
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struct tcf_common *pc;
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void *defdata;
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u32 datalen = 0;
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int ret = 0;
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if (rta == NULL || rtattr_parse_nested(tb, TCA_DEF_MAX, rta) < 0)
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return -EINVAL;
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if (tb[TCA_DEF_PARMS - 1] == NULL ||
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RTA_PAYLOAD(tb[TCA_DEF_PARMS - 1]) < sizeof(*parm))
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return -EINVAL;
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parm = RTA_DATA(tb[TCA_DEF_PARMS - 1]);
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defdata = RTA_DATA(tb[TCA_DEF_DATA - 1]);
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if (defdata == NULL)
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return -EINVAL;
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datalen = RTA_PAYLOAD(tb[TCA_DEF_DATA - 1]);
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if (datalen <= 0)
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return -EINVAL;
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pc = tcf_hash_check(parm->index, a, bind, &simp_hash_info);
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if (!pc) {
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pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind,
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&simp_idx_gen, &simp_hash_info);
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if (unlikely(!pc))
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return -ENOMEM;
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d = to_defact(pc);
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ret = alloc_defdata(d, datalen, defdata);
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if (ret < 0) {
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kfree(pc);
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return ret;
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}
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ret = ACT_P_CREATED;
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} else {
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d = to_defact(pc);
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if (!ovr) {
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tcf_simp_release(d, bind);
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return -EEXIST;
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}
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realloc_defdata(d, datalen, defdata);
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}
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spin_lock_bh(&d->tcf_lock);
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d->tcf_action = parm->action;
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spin_unlock_bh(&d->tcf_lock);
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if (ret == ACT_P_CREATED)
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tcf_hash_insert(pc, &simp_hash_info);
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return ret;
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}
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static inline int tcf_simp_cleanup(struct tc_action *a, int bind)
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{
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struct tcf_defact *d = a->priv;
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if (d)
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return tcf_simp_release(d, bind);
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return 0;
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}
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static inline int tcf_simp_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_defact *d = a->priv;
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struct tc_defact opt;
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struct tcf_t t;
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opt.index = d->tcf_index;
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opt.refcnt = d->tcf_refcnt - ref;
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opt.bindcnt = d->tcf_bindcnt - bind;
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opt.action = d->tcf_action;
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RTA_PUT(skb, TCA_DEF_PARMS, sizeof(opt), &opt);
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RTA_PUT(skb, TCA_DEF_DATA, d->tcfd_datalen, d->tcfd_defdata);
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t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install);
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t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse);
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t.expires = jiffies_to_clock_t(d->tcf_tm.expires);
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RTA_PUT(skb, TCA_DEF_TM, sizeof(t), &t);
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return skb->len;
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rtattr_failure:
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skb_trim(skb, b - skb->data);
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return -1;
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}
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static struct tc_action_ops act_simp_ops = {
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.kind = "simple",
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.hinfo = &simp_hash_info,
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.type = TCA_ACT_SIMP,
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.capab = TCA_CAP_NONE,
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.owner = THIS_MODULE,
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.act = tcf_simp,
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.dump = tcf_simp_dump,
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.cleanup = tcf_simp_cleanup,
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.init = tcf_simp_init,
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.walk = tcf_generic_walker,
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};
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MODULE_AUTHOR("Jamal Hadi Salim(2005)");
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MODULE_DESCRIPTION("Simple example action");
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MODULE_LICENSE("GPL");
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static int __init simp_init_module(void)
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{
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int ret = tcf_register_action(&act_simp_ops);
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if (!ret)
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printk("Simple TC action Loaded\n");
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return ret;
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}
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static void __exit simp_cleanup_module(void)
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{
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tcf_unregister_action(&act_simp_ops);
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}
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module_init(simp_init_module);
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module_exit(simp_cleanup_module);
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