From 99b7248e2ad57ca93ada10c6598affb267ffc99a Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 18 Mar 2016 14:33:45 +0100 Subject: [PATCH] openvswitch: call only into reachable nf-nat code The openvswitch code has gained support for calling into the nf-nat-ipv4/ipv6 modules, however those can be loadable modules in a configuration in which openvswitch is built-in, leading to link errors: net/built-in.o: In function `__ovs_ct_lookup': :(.text+0x2cc2c8): undefined reference to `nf_nat_icmp_reply_translation' :(.text+0x2cc66c): undefined reference to `nf_nat_icmpv6_reply_translation' The dependency on (!NF_NAT || NF_NAT) prevents similar issues, but NF_NAT is set to 'y' if any of the symbols selecting it are built-in, but the link error happens when any of them are modular. A second issue is that even if CONFIG_NF_NAT_IPV6 is built-in, CONFIG_NF_NAT_IPV4 might be completely disabled. This is unlikely to be useful in practice, but the driver currently only handles IPv6 being optional. This patch improves the Kconfig dependency so that openvswitch cannot be built-in if either of the two other symbols are set to 'm', and it replaces the incorrect #ifdef in ovs_ct_nat_execute() with two "if (IS_ENABLED())" checks that should catch all corner cases also make the code more readable. The same #ifdef exists ovs_ct_nat_to_attr(), where it does not cause a link error, but for consistency I'm changing it the same way. Signed-off-by: Arnd Bergmann Fixes: 05752523e565 ("openvswitch: Interface with NAT.") Acked-by: Joe Stringer Signed-off-by: Pablo Neira Ayuso --- net/openvswitch/Kconfig | 4 +++- net/openvswitch/conntrack.c | 16 ++++++++-------- 2 files changed, 11 insertions(+), 9 deletions(-) diff --git a/net/openvswitch/Kconfig b/net/openvswitch/Kconfig index 234a73344c6e..ce947292ae77 100644 --- a/net/openvswitch/Kconfig +++ b/net/openvswitch/Kconfig @@ -7,7 +7,9 @@ config OPENVSWITCH depends on INET depends on !NF_CONNTRACK || \ (NF_CONNTRACK && ((!NF_DEFRAG_IPV6 || NF_DEFRAG_IPV6) && \ - (!NF_NAT || NF_NAT))) + (!NF_NAT || NF_NAT) && \ + (!NF_NAT_IPV4 || NF_NAT_IPV4) && \ + (!NF_NAT_IPV6 || NF_NAT_IPV6))) select LIBCRC32C select MPLS select NET_MPLS_GSO diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c index 47f7c62761d2..3797879b0bf8 100644 --- a/net/openvswitch/conntrack.c +++ b/net/openvswitch/conntrack.c @@ -535,14 +535,15 @@ static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct, switch (ctinfo) { case IP_CT_RELATED: case IP_CT_RELATED_REPLY: - if (skb->protocol == htons(ETH_P_IP) && + if (IS_ENABLED(CONFIG_NF_NAT_IPV4) && + skb->protocol == htons(ETH_P_IP) && ip_hdr(skb)->protocol == IPPROTO_ICMP) { if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo, hooknum)) err = NF_DROP; goto push; -#if IS_ENABLED(CONFIG_NF_NAT_IPV6) - } else if (skb->protocol == htons(ETH_P_IPV6)) { + } else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) && + skb->protocol == htons(ETH_P_IPV6)) { __be16 frag_off; u8 nexthdr = ipv6_hdr(skb)->nexthdr; int hdrlen = ipv6_skip_exthdr(skb, @@ -557,7 +558,6 @@ static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct, err = NF_DROP; goto push; } -#endif } /* Non-ICMP, fall thru to initialize if needed. */ case IP_CT_NEW: @@ -1239,7 +1239,8 @@ static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info, } if (info->range.flags & NF_NAT_RANGE_MAP_IPS) { - if (info->family == NFPROTO_IPV4) { + if (IS_ENABLED(CONFIG_NF_NAT_IPV4) && + info->family == NFPROTO_IPV4) { if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN, info->range.min_addr.ip) || (info->range.max_addr.ip @@ -1247,8 +1248,8 @@ static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info, (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX, info->range.max_addr.ip)))) return false; -#if IS_ENABLED(CONFIG_NF_NAT_IPV6) - } else if (info->family == NFPROTO_IPV6) { + } else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) && + info->family == NFPROTO_IPV6) { if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN, &info->range.min_addr.in6) || (memcmp(&info->range.max_addr.in6, @@ -1257,7 +1258,6 @@ static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info, (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX, &info->range.max_addr.in6)))) return false; -#endif } else { return false; } -- 2.20.1