Messages in this thread Patch in this message | | | From | Michal Kubecek <> | Subject | [PATCH net 3/3] ethtool: reject unrecognized request flags | Date | Sun, 15 Mar 2020 18:17:53 +0100 (CET) |
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As pointed out by Jakub Kicinski, we ethtool netlink code should respond with an error if request head has flags set which are not recognized by kernel, either as a mistake or because it expects functionality introduced in later kernel versions.
To avoid unnecessary roundtrips, use extack cookie to provide the information about supported request flags.
Signed-off-by: Michal Kubecek <mkubecek@suse.cz> --- net/ethtool/netlink.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c index 180c194fab07..fc9e0b806889 100644 --- a/net/ethtool/netlink.c +++ b/net/ethtool/netlink.c @@ -40,6 +40,7 @@ int ethnl_parse_header(struct ethnl_req_info *req_info, struct nlattr *tb[ETHTOOL_A_HEADER_MAX + 1]; const struct nlattr *devname_attr; struct net_device *dev = NULL; + u32 flags = 0; int ret; if (!header) { @@ -50,8 +51,17 @@ int ethnl_parse_header(struct ethnl_req_info *req_info, ethnl_header_policy, extack); if (ret < 0) return ret; - devname_attr = tb[ETHTOOL_A_HEADER_DEV_NAME]; + if (tb[ETHTOOL_A_HEADER_FLAGS]) { + flags = nla_get_u32(tb[ETHTOOL_A_HEADER_FLAGS]); + if (flags & ~ETHTOOL_FLAG_ALL) { + NL_SET_ERR_MSG_ATTR(extack, tb[ETHTOOL_A_HEADER_FLAGS], + "unrecognized request flags"); + nl_set_extack_cookie_u32(extack, ETHTOOL_FLAG_ALL); + return -EOPNOTSUPP; + } + } + devname_attr = tb[ETHTOOL_A_HEADER_DEV_NAME]; if (tb[ETHTOOL_A_HEADER_DEV_INDEX]) { u32 ifindex = nla_get_u32(tb[ETHTOOL_A_HEADER_DEV_INDEX]); @@ -90,9 +100,7 @@ int ethnl_parse_header(struct ethnl_req_info *req_info, } req_info->dev = dev; - if (tb[ETHTOOL_A_HEADER_FLAGS]) - req_info->flags = nla_get_u32(tb[ETHTOOL_A_HEADER_FLAGS]); - + req_info->flags = flags; return 0; } -- 2.25.1
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