[PATCH] net: ipv4: Fix rtnexthop len when RTA_FLOW is present
From: Xiao Liang <hidden>
Date: 2021-09-22 09:49:37
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
Multipath RTA_FLOW is embedded in nexthop, thus add it to rtnexthop
length.
Fixes: b0f60193632e ("ipv4: Refactor nexthop attributes in fib_dump_info")
Signed-off-by: Xiao Liang <redacted>
---
net/ipv4/fib_semantics.c | 30 +++++++++++++++++++++---------
1 file changed, 21 insertions(+), 9 deletions(-)
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index b42c429cebbe..62b74edb5240 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c@@ -1660,8 +1660,9 @@ int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nhc, EXPORT_SYMBOL_GPL(fib_nexthop_info); #if IS_ENABLED(CONFIG_IP_ROUTE_MULTIPATH) || IS_ENABLED(CONFIG_IPV6) -int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc, - int nh_weight, u8 rt_family) +static struct rtnexthop *__fib_add_nexthop(struct sk_buff *skb, + const struct fib_nh_common *nhc, + int nh_weight, u8 rt_family) { const struct net_device *dev = nhc->nhc_dev; struct rtnexthop *rtnh;
@@ -1682,10 +1683,17 @@ int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc, /* length of rtnetlink header + attributes */ rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh; - return 0; + return rtnh; nla_put_failure: - return -EMSGSIZE; + return ERR_PTR(-EMSGSIZE); +} + +int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nhc, + int nh_weight, u8 rt_family) +{ + return PTR_ERR_OR_ZERO(__fib_add_nexthop(skb, nhc, nh_weight, + rt_family)); } EXPORT_SYMBOL_GPL(fib_add_nexthop); #endif
@@ -1706,13 +1714,17 @@ static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi) } for_nexthops(fi) { - if (fib_add_nexthop(skb, &nh->nh_common, nh->fib_nh_weight, - AF_INET) < 0) + struct rtnexthop *rtnh = __fib_add_nexthop(skb, &nh->nh_common, + nh->fib_nh_weight, + AF_INET); + if (IS_ERR(rtnh)) goto nla_put_failure; #ifdef CONFIG_IP_ROUTE_CLASSID - if (nh->nh_tclassid && - nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid)) - goto nla_put_failure; + if (nh->nh_tclassid) { + if (nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid)) + goto nla_put_failure; + rtnh->rtnh_len += nla_total_size(4); + } #endif } endfor_nexthops(fi);
--
2.33.0