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 @@ -69,6 +69,7 @@ struct netns_ipv6 { #ifdef CONFIG_IPV6_MULTIPLE_TABLES 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 @@ -73,6 +73,10 @@ 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 @@ -221,6 +221,7 @@ 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 @@ -2460,6 +2460,7 @@ 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 @@ -161,6 +161,7 @@ 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 @@ -121,6 +121,10 @@ static int fib6_rule_action(struct fib_r 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 @@ -168,6 +168,8 @@ 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 @@ -91,6 +91,8 @@ 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); @@ -321,6 +323,21 @@ static const struct rt6_info ip6_prohibi .rt6i_ref = ATOMIC_INIT(1), }; +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), + .rt6i_protocol = RTPROT_KERNEL, + .rt6i_metric = ~(u32) 0, + .rt6i_ref = ATOMIC_INIT(1), +}; + static const struct rt6_info ip6_blk_hole_entry_template = { .dst = { .__refcnt = ATOMIC_INIT(1), @@ -2041,6 +2058,11 @@ static struct rt6_info *ip6_route_info_c rt->dst.output = ip6_pkt_prohibit_out; rt->dst.input = ip6_pkt_prohibit; break; + case RTN_POLICY_FAILED: + rt->dst.error = -EACCES; + rt->dst.output = ip6_pkt_policy_failed_out; + rt->dst.input = ip6_pkt_policy_failed; + break; case RTN_THROW: case RTN_UNREACHABLE: default: @@ -2766,6 +2788,17 @@ 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. */ @@ -3000,7 +3033,8 @@ 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) @@ -3490,6 +3524,9 @@ static int rt6_fill_node(struct net *net case -EACCES: rtm->rtm_type = RTN_PROHIBIT; break; + case -EPERM: + rtm->rtm_type = RTN_POLICY_FAILED; + break; case -EAGAIN: rtm->rtm_type = RTN_THROW; break; @@ -3808,6 +3845,8 @@ 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 @@ -4035,6 +4074,17 @@ 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.path = + (struct dst_entry *)net->ipv6.ip6_policy_failed_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; @@ -4053,6 +4103,8 @@ 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: @@ -4070,6 +4122,7 @@ 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); } @@ -4143,6 +4196,9 @@ 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 }