From 2190d1d0944f84c55cdfdb89c7920f8f9311bdde Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Wed, 17 May 2017 11:07:59 +0200 Subject: [PATCH] net: sched: introduce helpers to work with filter chains Introduce struct tcf_chain object and set of helpers around it. Wraps up insertion, deletion and search in the filter chain. Signed-off-by: Jiri Pirko Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller --- include/net/sch_generic.h | 7 +- net/sched/cls_api.c | 148 +++++++++++++++++++++++++++----------- 2 files changed, 113 insertions(+), 42 deletions(-) diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 98cf2f23602d..52bceede534b 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -248,10 +248,15 @@ struct qdisc_skb_cb { unsigned char data[QDISC_CB_PRIV_LEN]; }; -struct tcf_block { +struct tcf_chain { + struct tcf_proto __rcu *filter_chain; struct tcf_proto __rcu **p_filter_chain; }; +struct tcf_block { + struct tcf_chain *chain; +}; + static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz) { struct qdisc_skb_cb *qcb; diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index 690457c988b2..fee3d7faeb79 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -106,13 +106,12 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb, static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb, struct nlmsghdr *n, - struct tcf_proto __rcu **chain, int event) + struct tcf_chain *chain, int event) { - struct tcf_proto __rcu **it_chain; struct tcf_proto *tp; - for (it_chain = chain; (tp = rtnl_dereference(*it_chain)) != NULL; - it_chain = &tp->next) + for (tp = rtnl_dereference(chain->filter_chain); + tp; tp = rtnl_dereference(tp->next)) tfilter_notify(net, oskb, n, tp, 0, event, false); } @@ -187,26 +186,49 @@ static void tcf_proto_destroy(struct tcf_proto *tp) kfree_rcu(tp, rcu); } -static void tcf_chain_destroy(struct tcf_proto __rcu **fl) +static struct tcf_chain *tcf_chain_create(void) +{ + return kzalloc(sizeof(struct tcf_chain), GFP_KERNEL); +} + +static void tcf_chain_destroy(struct tcf_chain *chain) { struct tcf_proto *tp; - while ((tp = rtnl_dereference(*fl)) != NULL) { - RCU_INIT_POINTER(*fl, tp->next); + while ((tp = rtnl_dereference(chain->filter_chain)) != NULL) { + RCU_INIT_POINTER(chain->filter_chain, tp->next); tcf_proto_destroy(tp); } + kfree(chain); +} + +static void +tcf_chain_filter_chain_ptr_set(struct tcf_chain *chain, + struct tcf_proto __rcu **p_filter_chain) +{ + chain->p_filter_chain = p_filter_chain; } int tcf_block_get(struct tcf_block **p_block, struct tcf_proto __rcu **p_filter_chain) { struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL); + int err; if (!block) return -ENOMEM; - block->p_filter_chain = p_filter_chain; + block->chain = tcf_chain_create(); + if (!block->chain) { + err = -ENOMEM; + goto err_chain_create; + } + tcf_chain_filter_chain_ptr_set(block->chain, p_filter_chain); *p_block = block; return 0; + +err_chain_create: + kfree(block); + return err; } EXPORT_SYMBOL(tcf_block_get); @@ -214,7 +236,7 @@ void tcf_block_put(struct tcf_block *block) { if (!block) return; - tcf_chain_destroy(block->p_filter_chain); + tcf_chain_destroy(block->chain); kfree(block); } EXPORT_SYMBOL(tcf_block_put); @@ -267,6 +289,65 @@ reset: } EXPORT_SYMBOL(tcf_classify); +struct tcf_chain_info { + struct tcf_proto __rcu **pprev; + struct tcf_proto __rcu *next; +}; + +static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info) +{ + return rtnl_dereference(*chain_info->pprev); +} + +static void tcf_chain_tp_insert(struct tcf_chain *chain, + struct tcf_chain_info *chain_info, + struct tcf_proto *tp) +{ + if (chain->p_filter_chain && + *chain_info->pprev == chain->filter_chain) + *chain->p_filter_chain = tp; + RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info)); + rcu_assign_pointer(*chain_info->pprev, tp); +} + +static void tcf_chain_tp_remove(struct tcf_chain *chain, + struct tcf_chain_info *chain_info, + struct tcf_proto *tp) +{ + struct tcf_proto *next = rtnl_dereference(chain_info->next); + + if (chain->p_filter_chain && tp == chain->filter_chain) + *chain->p_filter_chain = next; + RCU_INIT_POINTER(*chain_info->pprev, next); +} + +static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain, + struct tcf_chain_info *chain_info, + u32 protocol, u32 prio, + bool prio_allocate) +{ + struct tcf_proto **pprev; + struct tcf_proto *tp; + + /* Check the chain for existence of proto-tcf with this priority */ + for (pprev = &chain->filter_chain; + (tp = rtnl_dereference(*pprev)); pprev = &tp->next) { + if (tp->prio >= prio) { + if (tp->prio == prio) { + if (prio_allocate || + (tp->protocol != protocol && protocol)) + return ERR_PTR(-EINVAL); + } else { + tp = NULL; + } + break; + } + } + chain_info->pprev = pprev; + chain_info->next = tp ? tp->next : NULL; + return tp; +} + /* Add/change/delete/get a filter node */ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, @@ -281,10 +362,9 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, u32 parent; struct net_device *dev; struct Qdisc *q; - struct tcf_proto __rcu **back; - struct tcf_proto __rcu **chain; + struct tcf_chain_info chain_info; + struct tcf_chain *chain; struct tcf_block *block; - struct tcf_proto *next; struct tcf_proto *tp; const struct Qdisc_class_ops *cops; unsigned long cl; @@ -369,7 +449,7 @@ replay: err = -EINVAL; goto errout; } - chain = block->p_filter_chain; + chain = block->chain; if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) { tfilter_notify_chain(net, skb, n, chain, RTM_DELTFILTER); @@ -378,22 +458,11 @@ replay: goto errout; } - /* Check the chain for existence of proto-tcf with this priority */ - for (back = chain; - (tp = rtnl_dereference(*back)) != NULL; - back = &tp->next) { - if (tp->prio >= prio) { - if (tp->prio == prio) { - if (prio_allocate || - (tp->protocol != protocol && protocol)) { - err = -EINVAL; - goto errout; - } - } else { - tp = NULL; - } - break; - } + tp = tcf_chain_tp_find(chain, &chain_info, protocol, + prio, prio_allocate); + if (IS_ERR(tp)) { + err = PTR_ERR(tp); + goto errout; } if (tp == NULL) { @@ -411,7 +480,7 @@ replay: } if (prio_allocate) - prio = tcf_auto_prio(rtnl_dereference(*back)); + prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info)); tp = tcf_proto_create(nla_data(tca[TCA_KIND]), protocol, prio, parent, q, block); @@ -429,8 +498,7 @@ replay: if (fh == 0) { if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) { - next = rtnl_dereference(tp->next); - RCU_INIT_POINTER(*back, next); + tcf_chain_tp_remove(chain, &chain_info, tp); tfilter_notify(net, skb, n, tp, fh, RTM_DELTFILTER, false); tcf_proto_destroy(tp); @@ -459,11 +527,10 @@ replay: err = tp->ops->delete(tp, fh, &last); if (err) goto errout; - next = rtnl_dereference(tp->next); tfilter_notify(net, skb, n, tp, t->tcm_handle, RTM_DELTFILTER, false); if (last) { - RCU_INIT_POINTER(*back, next); + tcf_chain_tp_remove(chain, &chain_info, tp); tcf_proto_destroy(tp); } goto errout; @@ -480,10 +547,8 @@ replay: err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh, n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE); if (err == 0) { - if (tp_created) { - RCU_INIT_POINTER(tp->next, rtnl_dereference(*back)); - rcu_assign_pointer(*back, tp); - } + if (tp_created) + tcf_chain_tp_insert(chain, &chain_info, tp); tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER, false); } else { if (tp_created) @@ -584,7 +649,8 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) struct net_device *dev; struct Qdisc *q; struct tcf_block *block; - struct tcf_proto *tp, __rcu **chain; + struct tcf_proto *tp; + struct tcf_chain *chain; struct tcmsg *tcm = nlmsg_data(cb->nlh); unsigned long cl = 0; const struct Qdisc_class_ops *cops; @@ -615,11 +681,11 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) block = cops->tcf_block(q, cl); if (!block) goto errout; - chain = block->p_filter_chain; + chain = block->chain; s_t = cb->args[0]; - for (tp = rtnl_dereference(*chain), t = 0; + for (tp = rtnl_dereference(chain->filter_chain), t = 0; tp; tp = rtnl_dereference(tp->next), t++) { if (t < s_t) continue;