[PATCH RFC v2 net-next 08/25] rtnetlink: Update rtnl_stats_dump to support NLM_F_DUMP_PROPER_HDR
From: David Ahern <dsahern@kernel.org>
Date: 2018-10-02 07:09:18
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: David Ahern <redacted> Update rtnl_stats_dump to check for NLM_F_DUMP_PROPER_HDR in the netlink message header. If the flag is set, the dump request is expected to have an if_stats_msg struct as the header. All elements of the struct are expected to be 0 except filter_mask which must be non-0 (legacy behavior). No attributes are supported. Signed-off-by: David Ahern <redacted> --- net/core/rtnetlink.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 51a653b810be..1751baf0c823 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c@@ -4648,6 +4648,9 @@ static int rtnl_stats_get(struct sk_buff *skb, struct nlmsghdr *nlh, static int rtnl_stats_dump(struct sk_buff *skb, struct netlink_callback *cb) { + struct netlink_ext_ack *extack = cb->extack; + const struct nlmsghdr *nlh = cb->nlh; + bool proper_hdr = !!(nlh->nlmsg_flags & NLM_F_DUMP_PROPER_HDR); int h, s_h, err, s_idx, s_idxattr, s_prividx; struct net *net = sock_net(skb->sk); unsigned int flags = NLM_F_MULTI;
@@ -4668,9 +4671,26 @@ static int rtnl_stats_dump(struct sk_buff *skb, struct netlink_callback *cb) return -EINVAL; ifsm = nlmsg_data(cb->nlh); + + /* only requests using NLM_F_DUMP_PROPER_HDR can pass data to + * influence the dump. The legacy exception is filter_mask. + */ + if (proper_hdr) { + if (ifsm->pad1 || ifsm->pad2 || ifsm->ifindex) { + NL_SET_ERR_MSG(extack, "Invalid values in header for dump request"); + return -EINVAL; + } + if (nlmsg_len(cb->nlh) != nlmsg_msg_size(sizeof(*ifsm))) { + NL_SET_ERR_MSG(extack, "Invalid attributes after header"); + return -EINVAL; + } + } + filter_mask = ifsm->filter_mask; - if (!filter_mask) + if (!filter_mask) { + NL_SET_ERR_MSG(extack, "Invalid filter_mask in header"); return -EINVAL; + } for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { idx = 0;
--
2.11.0