From cc6090e985d7d62bf2f1230c507d5fbe9899c9ec Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Mon, 30 Sep 2019 11:48:19 +0200 Subject: [PATCH] net: rtnetlink: introduce helper to get net_device instance by ifname Introduce helper function rtnl_get_dev() that gets net_device structure instance pointer according to passed ifname or ifname attribute. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 45 ++++++++++++++++++++++++-------------------- 1 file changed, 25 insertions(+), 20 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index a0017737442f..77d4719e5be0 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -2778,6 +2778,23 @@ errout: return err; } +static struct net_device *rtnl_dev_get(struct net *net, + struct nlattr *ifname_attr, + char *ifname) +{ + char buffer[IFNAMSIZ]; + + if (!ifname) { + ifname = buffer; + if (ifname_attr) + nla_strlcpy(ifname, ifname_attr, IFNAMSIZ); + else + return NULL; + } + + return __dev_get_by_name(net, ifname); +} + static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { @@ -2807,7 +2824,7 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, if (ifm->ifi_index > 0) dev = __dev_get_by_index(net, ifm->ifi_index); else if (tb[IFLA_IFNAME]) - dev = __dev_get_by_name(net, ifname); + dev = rtnl_dev_get(net, NULL, ifname); else goto errout; @@ -2880,7 +2897,6 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, struct net *tgt_net = net; struct net_device *dev = NULL; struct ifinfomsg *ifm; - char ifname[IFNAMSIZ]; struct nlattr *tb[IFLA_MAX+1]; int err; int netnsid = -1; @@ -2894,9 +2910,6 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, if (err < 0) return err; - if (tb[IFLA_IFNAME]) - nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ); - if (tb[IFLA_TARGET_NETNSID]) { netnsid = nla_get_s32(tb[IFLA_TARGET_NETNSID]); tgt_net = rtnl_get_net_ns_capable(NETLINK_CB(skb).sk, netnsid); @@ -2909,7 +2922,7 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, if (ifm->ifi_index > 0) dev = __dev_get_by_index(tgt_net, ifm->ifi_index); else if (tb[IFLA_IFNAME]) - dev = __dev_get_by_name(tgt_net, ifname); + dev = rtnl_dev_get(net, tb[IFLA_IFNAME], NULL); else if (tb[IFLA_GROUP]) err = rtnl_group_dellink(tgt_net, nla_get_u32(tb[IFLA_GROUP])); else @@ -3081,7 +3094,7 @@ replay: if (ifm->ifi_index > 0) dev = __dev_get_by_index(net, ifm->ifi_index); else if (tb[IFLA_IFNAME]) - dev = __dev_get_by_name(net, ifname); + dev = rtnl_dev_get(net, NULL, ifname); else dev = NULL; @@ -3363,7 +3376,6 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh, struct net *net = sock_net(skb->sk); struct net *tgt_net = net; struct ifinfomsg *ifm; - char ifname[IFNAMSIZ]; struct nlattr *tb[IFLA_MAX+1]; struct net_device *dev = NULL; struct sk_buff *nskb; @@ -3386,9 +3398,6 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh, return PTR_ERR(tgt_net); } - if (tb[IFLA_IFNAME]) - nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ); - if (tb[IFLA_EXT_MASK]) ext_filter_mask = nla_get_u32(tb[IFLA_EXT_MASK]); @@ -3397,7 +3406,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh, if (ifm->ifi_index > 0) dev = __dev_get_by_index(tgt_net, ifm->ifi_index); else if (tb[IFLA_IFNAME]) - dev = __dev_get_by_name(tgt_net, ifname); + dev = rtnl_dev_get(tgt_net, tb[IFLA_IFNAME], NULL); else goto out; @@ -3480,16 +3489,12 @@ static int rtnl_linkprop(int cmd, struct sk_buff *skb, struct nlmsghdr *nlh, return err; ifm = nlmsg_data(nlh); - if (ifm->ifi_index > 0) { + if (ifm->ifi_index > 0) dev = __dev_get_by_index(net, ifm->ifi_index); - } else if (tb[IFLA_IFNAME]) { - char ifname[IFNAMSIZ]; - - nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ); - dev = __dev_get_by_name(net, ifname); - } else { + else if (tb[IFLA_IFNAME]) + dev = rtnl_dev_get(net, tb[IFLA_IFNAME], NULL); + else return -EINVAL; - } if (!dev) return -ENODEV; -- 2.30.2