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Diffstat (limited to 'net/sched/cls_api.c')
-rw-r--r--net/sched/cls_api.c131
1 files changed, 114 insertions, 17 deletions
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 5f9373ee47ce..266fcb34fefe 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -163,6 +163,23 @@ static inline u32 tcf_auto_prio(struct tcf_proto *tp)
return TC_H_MAJ(first);
}
+static bool tcf_proto_is_unlocked(const char *kind)
+{
+ const struct tcf_proto_ops *ops;
+ bool ret;
+
+ ops = tcf_proto_lookup_ops(kind, false, NULL);
+ /* On error return false to take rtnl lock. Proto lookup/create
+ * functions will perform lookup again and properly handle errors.
+ */
+ if (IS_ERR(ops))
+ return false;
+
+ ret = !!(ops->flags & TCF_PROTO_OPS_DOIT_UNLOCKED);
+ module_put(ops->owner);
+ return ret;
+}
+
static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
u32 prio, struct tcf_chain *chain,
bool rtnl_held,
@@ -1312,8 +1329,12 @@ static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
if (!IS_ERR_OR_NULL(block))
tcf_block_refcnt_put(block, rtnl_held);
- if (q)
- qdisc_put(q);
+ if (q) {
+ if (rtnl_held)
+ qdisc_put(q);
+ else
+ qdisc_put_unlocked(q);
+ }
}
struct tcf_block_owner_item {
@@ -1966,7 +1987,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
void *fh;
int err;
int tp_created;
- bool rtnl_held = true;
+ bool rtnl_held = false;
if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
return -EPERM;
@@ -1985,6 +2006,7 @@ replay:
parent = t->tcm_parent;
tp = NULL;
cl = 0;
+ block = NULL;
if (prio == 0) {
/* If no priority is provided by the user,
@@ -2001,8 +2023,27 @@ replay:
/* Find head of filter chain. */
- block = tcf_block_find(net, &q, &parent, &cl,
- t->tcm_ifindex, t->tcm_block_index, extack);
+ err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
+ if (err)
+ return err;
+
+ /* Take rtnl mutex if rtnl_held was set to true on previous iteration,
+ * block is shared (no qdisc found), qdisc is not unlocked, classifier
+ * type is not specified, classifier is not unlocked.
+ */
+ if (rtnl_held ||
+ (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
+ !tca[TCA_KIND] || !tcf_proto_is_unlocked(nla_data(tca[TCA_KIND]))) {
+ rtnl_held = true;
+ rtnl_lock();
+ }
+
+ err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
+ if (err)
+ goto errout;
+
+ block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
+ extack);
if (IS_ERR(block)) {
err = PTR_ERR(block);
goto errout;
@@ -2123,9 +2164,18 @@ errout_tp:
tcf_chain_put(chain);
}
tcf_block_release(q, block, rtnl_held);
- if (err == -EAGAIN)
+
+ if (rtnl_held)
+ rtnl_unlock();
+
+ if (err == -EAGAIN) {
+ /* Take rtnl lock in case EAGAIN is caused by concurrent flush
+ * of target chain.
+ */
+ rtnl_held = true;
/* Replay the request. */
goto replay;
+ }
return err;
errout_locked:
@@ -2146,12 +2196,12 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
struct Qdisc *q = NULL;
struct tcf_chain_info chain_info;
struct tcf_chain *chain = NULL;
- struct tcf_block *block;
+ struct tcf_block *block = NULL;
struct tcf_proto *tp = NULL;
unsigned long cl = 0;
void *fh = NULL;
int err;
- bool rtnl_held = true;
+ bool rtnl_held = false;
if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
return -EPERM;
@@ -2172,8 +2222,27 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
/* Find head of filter chain. */
- block = tcf_block_find(net, &q, &parent, &cl,
- t->tcm_ifindex, t->tcm_block_index, extack);
+ err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
+ if (err)
+ return err;
+
+ /* Take rtnl mutex if flushing whole chain, block is shared (no qdisc
+ * found), qdisc is not unlocked, classifier type is not specified,
+ * classifier is not unlocked.
+ */
+ if (!prio ||
+ (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
+ !tca[TCA_KIND] || !tcf_proto_is_unlocked(nla_data(tca[TCA_KIND]))) {
+ rtnl_held = true;
+ rtnl_lock();
+ }
+
+ err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
+ if (err)
+ goto errout;
+
+ block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
+ extack);
if (IS_ERR(block)) {
err = PTR_ERR(block);
goto errout;
@@ -2255,6 +2324,10 @@ errout:
tcf_chain_put(chain);
}
tcf_block_release(q, block, rtnl_held);
+
+ if (rtnl_held)
+ rtnl_unlock();
+
return err;
errout_locked:
@@ -2275,12 +2348,12 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
struct Qdisc *q = NULL;
struct tcf_chain_info chain_info;
struct tcf_chain *chain = NULL;
- struct tcf_block *block;
+ struct tcf_block *block = NULL;
struct tcf_proto *tp = NULL;
unsigned long cl = 0;
void *fh = NULL;
int err;
- bool rtnl_held = true;
+ bool rtnl_held = false;
err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, rtm_tca_policy, extack);
if (err < 0)
@@ -2298,8 +2371,26 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
/* Find head of filter chain. */
- block = tcf_block_find(net, &q, &parent, &cl,
- t->tcm_ifindex, t->tcm_block_index, extack);
+ err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
+ if (err)
+ return err;
+
+ /* Take rtnl mutex if block is shared (no qdisc found), qdisc is not
+ * unlocked, classifier type is not specified, classifier is not
+ * unlocked.
+ */
+ if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
+ !tca[TCA_KIND] || !tcf_proto_is_unlocked(nla_data(tca[TCA_KIND]))) {
+ rtnl_held = true;
+ rtnl_lock();
+ }
+
+ err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
+ if (err)
+ goto errout;
+
+ block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
+ extack);
if (IS_ERR(block)) {
err = PTR_ERR(block);
goto errout;
@@ -2352,6 +2443,10 @@ errout:
tcf_chain_put(chain);
}
tcf_block_release(q, block, rtnl_held);
+
+ if (rtnl_held)
+ rtnl_unlock();
+
return err;
}
@@ -3214,10 +3309,12 @@ static int __init tc_filter_init(void)
if (err)
goto err_rhash_setup_block_ht;
- rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL, 0);
- rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL, 0);
+ rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
+ RTNL_FLAG_DOIT_UNLOCKED);
+ rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
+ RTNL_FLAG_DOIT_UNLOCKED);
rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
- tc_dump_tfilter, 0);
+ tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED);
rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.