From: Jonas Gorski Subject: ipv6: allow rejecting with "source address failed policy" RFC6204 L-14 requires rejecting traffic from invalid addresses with ICMPv6 Destination Unreachable, Code 5 (Source address failed ingress/ egress policy) on the LAN side, so add an appropriate rule for that. Signed-off-by: Jonas Gorski --- include/net/netns/ipv6.h | 1 + include/uapi/linux/fib_rules.h | 4 +++ include/uapi/linux/rtnetlink.h | 1 + net/ipv4/fib_semantics.c | 4 +++ net/ipv4/fib_trie.c | 1 + net/ipv4/ipmr.c | 1 + net/ipv6/fib6_rules.c | 4 +++ net/ipv6/ip6mr.c | 2 ++ net/ipv6/route.c | 58 +++++++++++++++++++++++++++++++++++++++++- 9 files changed, 75 insertions(+), 1 deletion(-) --- a/include/net/netns/ipv6.h +++ b/include/net/netns/ipv6.h @@ -78,6 +78,7 @@ struct netns_ipv6 { unsigned int fib6_rules_require_fldissect; bool fib6_has_custom_rules; struct rt6_info *ip6_prohibit_entry; + struct rt6_info *ip6_policy_failed_entry; struct rt6_info *ip6_blk_hole_entry; struct fib6_table *fib6_local_tbl; struct fib_rules_ops *fib6_rules_ops; --- a/include/uapi/linux/fib_rules.h +++ b/include/uapi/linux/fib_rules.h @@ -82,6 +82,10 @@ enum { FR_ACT_BLACKHOLE, /* Drop without notification */ FR_ACT_UNREACHABLE, /* Drop with ENETUNREACH */ FR_ACT_PROHIBIT, /* Drop with EACCES */ + FR_ACT_RES9, + FR_ACT_RES10, + FR_ACT_RES11, + FR_ACT_POLICY_FAILED, /* Drop with EACCES */ __FR_ACT_MAX, }; --- a/include/uapi/linux/rtnetlink.h +++ b/include/uapi/linux/rtnetlink.h @@ -228,6 +228,7 @@ enum { RTN_THROW, /* Not in this table */ RTN_NAT, /* Translate this address */ RTN_XRESOLVE, /* Use external resolver */ + RTN_POLICY_FAILED, /* Failed ingress/egress policy */ __RTN_MAX }; --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -139,6 +139,10 @@ const struct fib_prop fib_props[RTN_MAX .error = -EINVAL, .scope = RT_SCOPE_NOWHERE, }, + [RTN_POLICY_FAILED] = { + .error = -EACCES, + .scope = RT_SCOPE_UNIVERSE, + }, }; static void rt_fibinfo_free(struct rtable __rcu **rtp) --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -2474,6 +2474,7 @@ static const char *const rtn_type_names[ [RTN_THROW] = "THROW", [RTN_NAT] = "NAT", [RTN_XRESOLVE] = "XRESOLVE", + [RTN_POLICY_FAILED] = "POLICY_FAILED", }; static inline const char *rtn_type(char *buf, size_t len, unsigned int t) --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -179,6 +179,7 @@ static int ipmr_rule_action(struct fib_r case FR_ACT_UNREACHABLE: return -ENETUNREACH; case FR_ACT_PROHIBIT: + case FR_ACT_POLICY_FAILED: return -EACCES; case FR_ACT_BLACKHOLE: default: --- a/net/ipv6/fib6_rules.c +++ b/net/ipv6/fib6_rules.c @@ -221,6 +221,10 @@ static int __fib6_rule_action(struct fib err = -EACCES; rt = net->ipv6.ip6_prohibit_entry; goto discard_pkt; + case FR_ACT_POLICY_FAILED: + err = -EACCES; + rt = net->ipv6.ip6_policy_failed_entry; + goto discard_pkt; } tb_id = fib_rule_get_table(rule, arg); --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -162,6 +162,8 @@ static int ip6mr_rule_action(struct fib_ return -ENETUNREACH; case FR_ACT_PROHIBIT: return -EACCES; + case FR_ACT_POLICY_FAILED: + return -EACCES; case FR_ACT_BLACKHOLE: default: return -EINVAL; --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -97,6 +97,8 @@ static int ip6_pkt_discard(struct sk_bu static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb); static int ip6_pkt_prohibit(struct sk_buff *skb); static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb); +static int ip6_pkt_policy_failed(struct sk_buff *skb); +static int ip6_pkt_policy_failed_out(struct net *net, struct sock *sk, struct sk_buff *skb); static void ip6_link_failure(struct sk_buff *skb); static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb, u32 mtu, @@ -328,6 +330,18 @@ static const struct rt6_info ip6_prohibi .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), }; +static const struct rt6_info ip6_policy_failed_entry_template = { + .dst = { + .__refcnt = ATOMIC_INIT(1), + .__use = 1, + .obsolete = DST_OBSOLETE_FORCE_CHK, + .error = -EACCES, + .input = ip6_pkt_policy_failed, + .output = ip6_pkt_policy_failed_out, + }, + .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), +}; + static const struct rt6_info ip6_blk_hole_entry_template = { .dst = { .__refcnt = ATOMIC_INIT(1), @@ -906,6 +920,7 @@ static const int fib6_prop[RTN_MAX + 1] [RTN_BLACKHOLE] = -EINVAL, [RTN_UNREACHABLE] = -EHOSTUNREACH, [RTN_PROHIBIT] = -EACCES, + [RTN_POLICY_FAILED] = -EACCES, [RTN_THROW] = -EAGAIN, [RTN_NAT] = -EINVAL, [RTN_XRESOLVE] = -EINVAL, @@ -943,6 +958,10 @@ static void ip6_rt_init_dst_reject(struc rt->dst.output = ip6_pkt_prohibit_out; rt->dst.input = ip6_pkt_prohibit; break; + case RTN_POLICY_FAILED: + rt->dst.output = ip6_pkt_policy_failed_out; + rt->dst.input = ip6_pkt_policy_failed; + break; case RTN_THROW: case RTN_UNREACHABLE: default: @@ -3789,6 +3808,17 @@ static int ip6_pkt_prohibit_out(struct n return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES); } +static int ip6_pkt_policy_failed(struct sk_buff *skb) +{ + return ip6_pkt_drop(skb, ICMPV6_POLICY_FAIL, IPSTATS_MIB_INNOROUTES); +} + +static int ip6_pkt_policy_failed_out(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + skb->dev = skb_dst(skb)->dev; + return ip6_pkt_drop(skb, ICMPV6_POLICY_FAIL, IPSTATS_MIB_OUTNOROUTES); +} + /* * Allocate a dst for local (unicast / anycast) address. */ @@ -4236,7 +4266,8 @@ static int rtm_to_fib6_config(struct sk_ if (rtm->rtm_type == RTN_UNREACHABLE || rtm->rtm_type == RTN_BLACKHOLE || rtm->rtm_type == RTN_PROHIBIT || - rtm->rtm_type == RTN_THROW) + rtm->rtm_type == RTN_THROW || + rtm->rtm_type == RTN_POLICY_FAILED) cfg->fc_flags |= RTF_REJECT; if (rtm->rtm_type == RTN_LOCAL) @@ -5085,6 +5116,8 @@ static int ip6_route_dev_notify(struct n #ifdef CONFIG_IPV6_MULTIPLE_TABLES net->ipv6.ip6_prohibit_entry->dst.dev = dev; net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev); + net->ipv6.ip6_policy_failed_entry->dst.dev = dev; + net->ipv6.ip6_policy_failed_entry->rt6i_idev = in6_dev_get(dev); net->ipv6.ip6_blk_hole_entry->dst.dev = dev; net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev); #endif @@ -5096,6 +5129,7 @@ static int ip6_route_dev_notify(struct n in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev); #ifdef CONFIG_IPV6_MULTIPLE_TABLES in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev); + in6_dev_put_clear(&net->ipv6.ip6_policy_failed_entry->rt6i_idev); in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev); #endif } @@ -5290,6 +5324,15 @@ static int __net_init ip6_route_net_init net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops; dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst, ip6_template_metrics, true); + + net->ipv6.ip6_policy_failed_entry = + kmemdup(&ip6_policy_failed_entry_template, + sizeof(*net->ipv6.ip6_policy_failed_entry), GFP_KERNEL); + if (!net->ipv6.ip6_policy_failed_entry) + goto out_ip6_blk_hole_entry; + net->ipv6.ip6_policy_failed_entry->dst.ops = &net->ipv6.ip6_dst_ops; + dst_init_metrics(&net->ipv6.ip6_policy_failed_entry->dst, + ip6_template_metrics, true); #endif net->ipv6.sysctl.flush_delay = 0; @@ -5308,6 +5351,8 @@ out: return ret; #ifdef CONFIG_IPV6_MULTIPLE_TABLES +out_ip6_blk_hole_entry: + kfree(net->ipv6.ip6_blk_hole_entry); out_ip6_prohibit_entry: kfree(net->ipv6.ip6_prohibit_entry); out_ip6_null_entry: @@ -5328,6 +5373,7 @@ static void __net_exit ip6_route_net_exi #ifdef CONFIG_IPV6_MULTIPLE_TABLES kfree(net->ipv6.ip6_prohibit_entry); kfree(net->ipv6.ip6_blk_hole_entry); + kfree(net->ipv6.ip6_policy_failed_entry); #endif dst_entries_destroy(&net->ipv6.ip6_dst_ops); } @@ -5404,6 +5450,9 @@ void __init ip6_route_init_special_entri init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev; init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); + init_net.ipv6.ip6_policy_failed_entry->dst.dev = init_net.loopback_dev; + init_net.ipv6.ip6_policy_failed_entry->rt6i_idev = + in6_dev_get(init_net.loopback_dev); #endif }