// SPDX-License-Identifier: GPL-2.0-or-later /* * net/sched/act_gact.c Generic actions * * copyright Jamal Hadi Salim (2002-4) */ #include <linux/types.h> #include <linux/kernel.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/skbuff.h> #include <linux/rtnetlink.h> #include <linux/module.h> #include <linux/init.h> #include <net/netlink.h> #include <net/pkt_sched.h> #include <net/pkt_cls.h> #include <linux/tc_act/tc_gact.h> #include <net/tc_act/tc_gact.h> static unsigned int gact_net_id; static struct tc_action_ops act_gact_ops; #ifdef CONFIG_GACT_PROB static int gact_net_rand(struct tcf_gact *gact) { smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */ if (prandom_u32() % gact->tcfg_pval) return gact->tcf_action; return gact->tcfg_paction; } static int gact_determ(struct tcf_gact *gact) { u32 pack = atomic_inc_return(&gact->packets); smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */ if (pack % gact->tcfg_pval) return gact->tcf_action; return gact->tcfg_paction; } typedef int (*g_rand)(struct tcf_gact *gact); static g_rand gact_rand[MAX_RAND] = { NULL, gact_net_rand, gact_determ }; #endif /* CONFIG_GACT_PROB */ static const struct nla_policy gact_policy[TCA_GACT_MAX + 1] = { [TCA_GACT_PARMS] = { .len = sizeof(struct tc_gact) }, [TCA_GACT_PROB] = { .len = sizeof(struct tc_gact_p) }, }; static int tcf_gact_init(struct net *net, struct nlattr *nla, struct nlattr *est, struct tc_action **a, int ovr, int bind, bool rtnl_held, struct tcf_proto *tp, u32 flags, struct netlink_ext_ack *extack) { struct tc_action_net *tn = net_generic(net, gact_net_id); struct nlattr *tb[TCA_GACT_MAX + 1]; struct tcf_chain *goto_ch = NULL; struct tc_gact *parm; struct tcf_gact *gact; int ret = 0; u32 index; int err; #ifdef CONFIG_GACT_PROB struct tc_gact_p *p_parm = NULL; #endif if (nla == NULL) return -EINVAL; err = nla_parse_nested_deprecated(tb, TCA_GACT_MAX, nla, gact_policy, NULL); if (err < 0) return err; if (tb[TCA_GACT_PARMS] == NULL) return -EINVAL; parm = nla_data(tb[TCA_GACT_PARMS]); index = parm->index; #ifndef CONFIG_GACT_PROB if (tb[TCA_GACT_PROB] != NULL) return -EOPNOTSUPP; #else if (tb[TCA_GACT_PROB]) { p_parm = nla_data(tb[TCA_GACT_PROB]); if (p_parm->ptype >= MAX_RAND) return -EINVAL; if (TC_ACT_EXT_CMP(p_parm->paction, TC_ACT_GOTO_CHAIN)) { NL_SET_ERR_MSG(extack, "goto chain not allowed on fallback"); return -EINVAL; } } #endif err = tcf_idr_check_alloc(tn, &index, a, bind); if (!err) { ret = tcf_idr_create_from_flags(tn, index, est, a, &act_gact_ops, bind, flags); if (ret) { tcf_idr_cleanup(tn, index); return ret; } ret = ACT_P_CREATED; } else if (err > 0) { if (bind)/* dont override defaults */ return 0; if (!ovr) { tcf_idr_release(*a, bind); return -EEXIST; } } else { return err; } err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); if (err < 0) goto release_idr; gact = to_gact(*a); spin_lock_bh(&gact->tcf_lock); goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); #ifdef CONFIG_GACT_PROB if (p_parm) { gact->tcfg_paction = p_parm->paction; gact->tcfg_pval = max_t(u16, 1, p_parm->pval); /* Make sure tcfg_pval is written before tcfg_ptype * coupled with smp_rmb() in gact_net_rand() & gact_determ() */ smp_wmb(); gact->tcfg_ptype = p_parm->ptype; } #endif spin_unlock_bh(&gact->tcf_lock); if (goto_ch) tcf_chain_put_by_act(goto_ch); if (ret == ACT_P_CREATED) tcf_idr_insert(tn, *a); return ret; release_idr: tcf_idr_release(*a, bind); return err; } static int tcf_gact_act(struct sk_buff *skb, const struct tc_action *a, struct tcf_result *res) { struct tcf_gact *gact = to_gact(a); int action = READ_ONCE(gact->tcf_action); #ifdef CONFIG_GACT_PROB { u32 ptype = READ_ONCE(gact->tcfg_ptype); if (ptype) action = gact_rand[ptype](gact); } #endif tcf_action_update_bstats(&gact->common, skb); if (action == TC_ACT_SHOT) tcf_action_inc_drop_qstats(&gact->common); tcf_lastuse_update(&gact->tcf_tm); return action; } static void tcf_gact_stats_update(struct tc_action *a, u64 bytes, u64 packets, u64 drops, u64 lastuse, bool hw) { struct tcf_gact *gact = to_gact(a); int action = READ_ONCE(gact->tcf_action); struct tcf_t *tm = &gact->tcf_tm; tcf_action_update_stats(a, bytes, packets, action == TC_ACT_SHOT ? packets : drops, hw); tm->lastuse = max_t(u64, tm->lastuse, lastuse); } static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) { unsigned char *b = skb_tail_pointer(skb); struct tcf_gact *gact = to_gact(a); struct tc_gact opt = { .index = gact->tcf_index, .refcnt = refcount_read(&gact->tcf_refcnt) - ref, .bindcnt = atomic_read(&gact->tcf_bindcnt) - bind, }; struct tcf_t t; spin_lock_bh(&gact->tcf_lock); opt.action = gact->tcf_action; if (nla_put(skb, TCA_GACT_PARMS, sizeof(opt), &opt)) goto nla_put_failure; #ifdef CONFIG_GACT_PROB if (gact->tcfg_ptype) { struct tc_gact_p p_opt = { .paction = gact->tcfg_paction, .pval = gact->tcfg_pval, .ptype = gact->tcfg_ptype, }; if (nla_put(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt)) goto nla_put_failure; } #endif tcf_tm_dump(&t, &gact->tcf_tm); if (nla_put_64bit(skb, TCA_GACT_TM, sizeof(t), &t, TCA_GACT_PAD)) goto nla_put_failure; spin_unlock_bh(&gact->tcf_lock); return skb->len; nla_put_failure: spin_unlock_bh(&gact->tcf_lock); nlmsg_trim(skb, b); return -1; } static int tcf_gact_walker(struct net *net, struct sk_buff *skb, struct netlink_callback *cb, int type, const struct tc_action_ops *ops, struct netlink_ext_ack *extack) { struct tc_action_net *tn = net_generic(net, gact_net_id); return tcf_generic_walker(tn, skb, cb, type, ops, extack); } static int tcf_gact_search(struct net *net, struct tc_action **a, u32 index) { struct tc_action_net *tn = net_generic(net, gact_net_id); return tcf_idr_search(tn, a, index); } static size_t tcf_gact_get_fill_size(const struct tc_action *act) { size_t sz = nla_total_size(sizeof(struct tc_gact)); /* TCA_GACT_PARMS */ #ifdef CONFIG_GACT_PROB if (to_gact(act)->tcfg_ptype) /* TCA_GACT_PROB */ sz += nla_total_size(sizeof(struct tc_gact_p)); #endif return sz; } static struct tc_action_ops act_gact_ops = { .kind = "gact", .id = TCA_ID_GACT, .owner = THIS_MODULE, .act = tcf_gact_act, .stats_update = tcf_gact_stats_update, .dump = tcf_gact_dump, .init = tcf_gact_init, .walk = tcf_gact_walker, .lookup = tcf_gact_search, .get_fill_size = tcf_gact_get_fill_size, .size = sizeof(struct tcf_gact), }; static __net_init int gact_init_net(struct net *net) { struct tc_action_net *tn = net_generic(net, gact_net_id); return tc_action_net_init(net, tn, &act_gact_ops); } static void __net_exit gact_exit_net(struct list_head *net_list) { tc_action_net_exit(net_list, gact_net_id); } static struct pernet_operations gact_net_ops = { .init = gact_init_net, .exit_batch = gact_exit_net, .id = &gact_net_id, .size = sizeof(struct tc_action_net), }; MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); MODULE_DESCRIPTION("Generic Classifier actions"); MODULE_LICENSE("GPL"); static int __init gact_init_module(void) { #ifdef CONFIG_GACT_PROB pr_info("GACT probability on\n"); #else pr_info("GACT probability NOT on\n"); #endif return tcf_register_action(&act_gact_ops, &gact_net_ops); } static void __exit gact_cleanup_module(void) { tcf_unregister_action(&act_gact_ops, &gact_net_ops); } module_init(gact_init_module); module_exit(gact_cleanup_module);