diff options
Diffstat (limited to 'net/ipv4/fib_semantics.c')
| -rw-r--r-- | net/ipv4/fib_semantics.c | 36 |
1 files changed, 30 insertions, 6 deletions
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 884d176e008..e63b8a98fb4 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -273,25 +273,49 @@ int ip_fib_check_default(__be32 gw, struct net_device *dev) return -1; } +static inline size_t fib_nlmsg_size(struct fib_info *fi) +{ + size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg)) + + nla_total_size(4) /* RTA_TABLE */ + + nla_total_size(4) /* RTA_DST */ + + nla_total_size(4) /* RTA_PRIORITY */ + + nla_total_size(4); /* RTA_PREFSRC */ + + /* space for nested metrics */ + payload += nla_total_size((RTAX_MAX * nla_total_size(4))); + + if (fi->fib_nhs) { + /* Also handles the special case fib_nhs == 1 */ + + /* each nexthop is packed in an attribute */ + size_t nhsize = nla_total_size(sizeof(struct rtnexthop)); + + /* may contain flow and gateway attribute */ + nhsize += 2 * nla_total_size(4); + + /* all nexthops are packed in a nested attribute */ + payload += nla_total_size(fi->fib_nhs * nhsize); + } + + return payload; +} + void rtmsg_fib(int event, __be32 key, struct fib_alias *fa, int dst_len, u32 tb_id, struct nl_info *info) { struct sk_buff *skb; - int payload = sizeof(struct rtmsg) + 256; u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; int err = -ENOBUFS; - skb = nlmsg_new(nlmsg_total_size(payload), GFP_KERNEL); + skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL); if (skb == NULL) goto errout; err = fib_dump_info(skb, info->pid, seq, event, tb_id, fa->fa_type, fa->fa_scope, key, dst_len, fa->fa_tos, fa->fa_info, 0); - if (err < 0) { - kfree_skb(skb); - goto errout; - } + /* failure implies BUG in fib_nlmsg_size() */ + BUG_ON(err < 0); err = rtnl_notify(skb, info->pid, RTNLGRP_IPV4_ROUTE, info->nlh, GFP_KERNEL); |