[IPV6]: Policy Routing Rules

Adds support for policy routing rules including a new
local table for routes with a local destination.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 251 insertions, 0 deletions

diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
new file mode 100644
index 000000000000..c3c8195744ee
--- /dev/null
+++ b/net/ipv6/fib6_rules.c
@@ -0,0 +1,251 @@
+/*
+ * net/ipv6/fib6_rules.c        IPv6 Routing Policy Rules
+ *
+ * Copyright (C)2003-2006 Helsinki University of Technology
+ * Copyright (C)2003-2006 USAGI/WIDE Project
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License as
+ *      published by the Free Software Foundation, version 2.
+ *
+ * Authors
+ *      Thomas Graf             <tgraf@suug.ch>
+ *      Ville Nuorvala          <vnuorval@tcs.hut.fi>
+ */
+
+#include <linux/config.h>
+#include <linux/netdevice.h>
+
+#include <net/fib_rules.h>
+#include <net/ipv6.h>
+#include <net/ip6_route.h>
+#include <net/netlink.h>
+
+struct fib6_rule
+{
+        struct fib_rule         common;
+        struct rt6key           src;
+        struct rt6key           dst;
+        u8                      tclass;
+};
+
+static struct fib_rules_ops fib6_rules_ops;
+
+static struct fib6_rule main_rule = {
+        .common = {
+                .refcnt =       ATOMIC_INIT(2),
+                .pref =         0x7FFE,
+                .action =       FR_ACT_TO_TBL,
+                .table =        RT6_TABLE_MAIN,
+        },
+};
+
+static struct fib6_rule local_rule = {
+        .common = {
+                .refcnt =       ATOMIC_INIT(2),
+                .pref =         0,
+                .action =       FR_ACT_TO_TBL,
+                .table =        RT6_TABLE_LOCAL,
+                .flags =        FIB_RULE_PERMANENT,
+        },
+};
+
+static LIST_HEAD(fib6_rules);
+
+struct dst_entry *fib6_rule_lookup(struct flowi *fl, int flags,
+                                   pol_lookup_t lookup)
+{
+        struct fib_lookup_arg arg = {
+                .lookup_ptr = lookup,
+        };
+
+        fib_rules_lookup(&fib6_rules_ops, fl, flags, &arg);
+        if (arg.rule)
+                fib_rule_put(arg.rule);
+
+        return (struct dst_entry *) arg.result;
+}
+
+int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
+                     int flags, struct fib_lookup_arg *arg)
+{
+        struct rt6_info *rt = NULL;
+        struct fib6_table *table;
+        pol_lookup_t lookup = arg->lookup_ptr;
+
+        switch (rule->action) {
+        case FR_ACT_TO_TBL:
+                break;
+        case FR_ACT_UNREACHABLE:
+                rt = &ip6_null_entry;
+                goto discard_pkt;
+        default:
+        case FR_ACT_BLACKHOLE:
+                rt = &ip6_blk_hole_entry;
+                goto discard_pkt;
+        case FR_ACT_PROHIBIT:
+                rt = &ip6_prohibit_entry;
+                goto discard_pkt;
+        }
+
+        table = fib6_get_table(rule->table);
+        if (table)
+                rt = lookup(table, flp, flags);
+
+        if (rt != &ip6_null_entry)
+                goto out;
+
+        dst_release(&rt->u.dst);
+discard_pkt:
+        dst_hold(&rt->u.dst);
+out:
+        arg->result = rt;
+        return rt == NULL ? -EAGAIN : 0;
+}
+
+
+static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
+{
+        struct fib6_rule *r = (struct fib6_rule *) rule;
+
+        if (!ipv6_prefix_equal(&fl->fl6_dst, &r->dst.addr, r->dst.plen))
+                return 0;
+
+        if ((flags & RT6_F_HAS_SADDR) &&
+            !ipv6_prefix_equal(&fl->fl6_src, &r->src.addr, r->src.plen))
+                return 0;
+
+        return 1;
+}
+
+static struct nla_policy fib6_rule_policy[RTA_MAX+1] __read_mostly = {
+        [FRA_IFNAME]    = { .type = NLA_STRING },
+        [FRA_PRIORITY]  = { .type = NLA_U32 },
+        [FRA_SRC]       = { .minlen = sizeof(struct in6_addr) },
+        [FRA_DST]       = { .minlen = sizeof(struct in6_addr) },
+};
+
+static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
+                               struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
+                               struct nlattr **tb)
+{
+        int err = -EINVAL;
+        struct fib6_rule *rule6 = (struct fib6_rule *) rule;
+
+        if (frh->src_len > 128 || frh->dst_len > 128 ||
+            (frh->tos & ~IPV6_FLOWINFO_MASK))
+                goto errout;
+
+        if (rule->action == FR_ACT_TO_TBL) {
+                if (rule->table == RT6_TABLE_UNSPEC)
+                        goto errout;
+
+                if (fib6_new_table(rule->table) == NULL) {
+                        err = -ENOBUFS;
+                        goto errout;
+                }
+        }
+
+        if (tb[FRA_SRC])
+                nla_memcpy(&rule6->src.addr, tb[FRA_SRC],
+                           sizeof(struct in6_addr));
+
+        if (tb[FRA_DST])
+                nla_memcpy(&rule6->dst.addr, tb[FRA_DST],
+                           sizeof(struct in6_addr));
+
+        rule6->src.plen = frh->src_len;
+        rule6->dst.plen = frh->dst_len;
+        rule6->tclass = frh->tos;
+
+        err = 0;
+errout:
+        return err;
+}
+
+static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
+                             struct nlattr **tb)
+{
+        struct fib6_rule *rule6 = (struct fib6_rule *) rule;
+
+        if (frh->src_len && (rule6->src.plen != frh->src_len))
+                return 0;
+
+        if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
+                return 0;
+
+        if (frh->tos && (rule6->tclass != frh->tos))
+                return 0;
+
+        if (tb[FRA_SRC] &&
+            nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
+                return 0;
+
+        if (tb[FRA_DST] &&
+            nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
+                return 0;
+
+        return 1;
+}
+
+static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
+                          struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
+{
+        struct fib6_rule *rule6 = (struct fib6_rule *) rule;
+
+        frh->family = AF_INET6;
+        frh->dst_len = rule6->dst.plen;
+        frh->src_len = rule6->src.plen;
+        frh->tos = rule6->tclass;
+
+        if (rule6->dst.plen)
+                NLA_PUT(skb, FRA_DST, sizeof(struct in6_addr),
+                        &rule6->dst.addr);
+
+        if (rule6->src.plen)
+                NLA_PUT(skb, FRA_SRC, sizeof(struct in6_addr),
+                        &rule6->src.addr);
+
+        return 0;
+
+nla_put_failure:
+        return -ENOBUFS;
+}
+
+int fib6_rules_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+        return fib_rules_dump(skb, cb, AF_INET6);
+}
+
+static u32 fib6_rule_default_pref(void)
+{
+        return 0x3FFF;
+}
+
+static struct fib_rules_ops fib6_rules_ops = {
+        .family                 = AF_INET6,
+        .rule_size              = sizeof(struct fib6_rule),
+        .action                 = fib6_rule_action,
+        .match                  = fib6_rule_match,
+        .configure              = fib6_rule_configure,
+        .compare                = fib6_rule_compare,
+        .fill                   = fib6_rule_fill,
+        .default_pref           = fib6_rule_default_pref,
+        .nlgroup                = RTNLGRP_IPV6_RULE,
+        .policy                 = fib6_rule_policy,
+        .rules_list             = &fib6_rules,
+        .owner                  = THIS_MODULE,
+};
+
+void __init fib6_rules_init(void)
+{
+        list_add_tail(&local_rule.common.list, &fib6_rules);
+        list_add_tail(&main_rule.common.list, &fib6_rules);
+
+        fib_rules_register(&fib6_rules_ops);
+}
+
+void fib6_rules_cleanup(void)
+{
+        fib_rules_unregister(&fib6_rules_ops);
+}