A deferred resize of nl_table causes the offsets that Netlink diag keeps
to become inaccurate. Mark the dump as inconsistent and have user space
request a new dump.
Signed-off-by: Thomas Graf <tgraf@xxxxxxx>
---
net/netlink/af_netlink.c | 10 ++++++++++
net/netlink/af_netlink.h | 1 +
net/netlink/diag.c | 1 +
3 files changed, 12 insertions(+)
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 7a94185..e214557 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -91,6 +91,9 @@ static inline int netlink_is_kernel(struct sock *sk)
struct netlink_table *nl_table;
EXPORT_SYMBOL_GPL(nl_table);
+atomic_t nl_table_seq;
+EXPORT_SYMBOL_GPL(nl_table_seq);
+
static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
static int netlink_dump(struct sock *sk);
@@ -3071,6 +3074,12 @@ static const struct net_proto_family netlink_family_ops = {
.owner = THIS_MODULE, /* for consistency 8) */
};
+static void nl_table_resize_notify(const struct rhashtable *ht,
+ enum rht_resize_op op)
+{
+ atomic_inc(&nl_table_seq);
+}
+
static int __net_init netlink_net_init(struct net *net)
{
#ifdef CONFIG_PROC_FS
@@ -3124,6 +3133,7 @@ static int __init netlink_proto_init(void)
.max_shift = 16, /* 64K */
.grow_decision = rht_grow_above_75,
.shrink_decision = rht_shrink_below_30,
+ .resize_notify = nl_table_resize_notify,
};
if (err != 0)
diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h
index 7518375..51c23c0 100644
--- a/net/netlink/af_netlink.h
+++ b/net/netlink/af_netlink.h
@@ -74,5 +74,6 @@ struct netlink_table {
extern struct netlink_table *nl_table;
extern rwlock_t nl_table_lock;
+extern atomic_t nl_table_seq;
#endif
diff --git a/net/netlink/diag.c b/net/netlink/diag.c
index 3ee63a3..50aa385 100644
--- a/net/netlink/diag.c
+++ b/net/netlink/diag.c
@@ -112,6 +112,7 @@ static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
int ret = 0, num = 0, i;
req = nlmsg_data(cb->nlh);
+ cb->seq = atomic_read(&nl_table_seq);
for (i = 0; i < htbl->size; i++) {
struct rhash_head *pos;
--
1.9.3
--
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