Userspace needs to reliably know the ifindex of the netdevs it creates, as we cannot rely on the ifname staying unchanged.
Earlier, a simlpe NLMSG_ERROR would be returned, but this returns the corresponding RTM_NEWLINK on success instead. Signed-off-by: Tom Gundersen <[email protected]> Cc: Marcel Holtmann <[email protected]> Cc: David S. Miller <[email protected]> --- net/core/rtnetlink.c | 100 ++++++++++++++++++++++++++------------------------- 1 file changed, 52 insertions(+), 48 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index cf67144..31c1322 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1725,6 +1725,54 @@ static int rtnl_group_changelink(struct net *net, int group, return 0; } +static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh) +{ + struct net *net = sock_net(skb->sk); + struct ifinfomsg *ifm; + char ifname[IFNAMSIZ]; + struct nlattr *tb[IFLA_MAX+1]; + struct net_device *dev = NULL; + struct sk_buff *nskb; + int err; + u32 ext_filter_mask = 0; + + err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy); + if (err < 0) + return err; + + 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]); + + ifm = nlmsg_data(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); + else + return -EINVAL; + + if (dev == NULL) + return -ENODEV; + + nskb = nlmsg_new(if_nlmsg_size(dev, ext_filter_mask), GFP_KERNEL); + if (nskb == NULL) + return -ENOBUFS; + + err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).portid, + nlh->nlmsg_seq, 0, 0, ext_filter_mask); + if (err < 0) { + /* -EMSGSIZE implies BUG in if_nlmsg_size */ + WARN_ON(err == -EMSGSIZE); + kfree_skb(nskb); + } else + err = rtnl_unicast(nskb, net, NETLINK_CB(skb).portid); + + return err; +} + static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh) { struct net *net = sock_net(skb->sk); @@ -1871,63 +1919,19 @@ replay: goto out; } + ifm->ifi_index = dev->ifindex; + err = rtnl_configure_link(dev, ifm); if (err < 0) unregister_netdevice(dev); + else + rtnl_getlink(skb, nlh); out: put_net(dest_net); return err; } } -static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh) -{ - struct net *net = sock_net(skb->sk); - struct ifinfomsg *ifm; - char ifname[IFNAMSIZ]; - struct nlattr *tb[IFLA_MAX+1]; - struct net_device *dev = NULL; - struct sk_buff *nskb; - int err; - u32 ext_filter_mask = 0; - - err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy); - if (err < 0) - return err; - - 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]); - - ifm = nlmsg_data(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); - else - return -EINVAL; - - if (dev == NULL) - return -ENODEV; - - nskb = nlmsg_new(if_nlmsg_size(dev, ext_filter_mask), GFP_KERNEL); - if (nskb == NULL) - return -ENOBUFS; - - err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).portid, - nlh->nlmsg_seq, 0, 0, ext_filter_mask); - if (err < 0) { - /* -EMSGSIZE implies BUG in if_nlmsg_size */ - WARN_ON(err == -EMSGSIZE); - kfree_skb(nskb); - } else - err = rtnl_unicast(nskb, net, NETLINK_CB(skb).portid); - - return err; -} - static u16 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh) { struct net *net = sock_net(skb->sk); -- 1.8.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
