[NETLINK]: Do precise netlink message allocations where possible

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv4 / devinet.c

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 7602c79a389bece923dc5dfd8b00b524690d8d85..f38cbbae0ae3bbc1c40489e02b02231d3a493564 100644 (file)
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1120,6 +1120,16 @@ static struct notifier_block ip_netdev_notifier = {
        .notifier_call =inetdev_event,
 };
 
+static inline size_t inet_nlmsg_size(void)
+{
+       return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
+              + nla_total_size(4) /* IFA_ADDRESS */
+              + nla_total_size(4) /* IFA_LOCAL */
+              + nla_total_size(4) /* IFA_BROADCAST */
+              + nla_total_size(4) /* IFA_ANYCAST */
+              + nla_total_size(IFNAMSIZ); /* IFA_LABEL */
+}
+
 static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
                            u32 pid, u32 seq, int event, unsigned int flags)
 {
@@ -1208,15 +1218,13 @@ static void rtmsg_ifa(int event, struct in_ifaddr* ifa, struct nlmsghdr *nlh,
        u32 seq = nlh ? nlh->nlmsg_seq : 0;
        int err = -ENOBUFS;
 
-       skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+       skb = nlmsg_new(inet_nlmsg_size(), GFP_KERNEL);
        if (skb == NULL)
                goto errout;
 
        err = inet_fill_ifaddr(skb, ifa, pid, seq, event, 0);
-       if (err < 0) {
-               kfree_skb(skb);
-               goto errout;
-       }
+       /* failure implies BUG in inet_nlmsg_size() */
+       BUG_ON(err < 0);
 
        err = rtnl_notify(skb, pid, RTNLGRP_IPV4_IFADDR, nlh, GFP_KERNEL);
 errout: