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| author | Stefan Tomanek <stefan.tomanek@wertarbyte.de> | 2013-08-01 02:17:15 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-07-31 17:27:17 -0700 |
| commit | 7764a45a8f1fe74d4f7d301eaca2e558e7e2831a (patch) | |
| tree | 39e20aa1dd22859d315da33b858074651efed7b9 /net/core | |
| parent | 5c15257f93234aaa9775291a041b49eeb38fd95a (diff) | |
| download | linux-7764a45a8f1fe74d4f7d301eaca2e558e7e2831a.tar.gz linux-7764a45a8f1fe74d4f7d301eaca2e558e7e2831a.tar.bz2 linux-7764a45a8f1fe74d4f7d301eaca2e558e7e2831a.zip | |
fib_rules: add .suppress operation
This change adds a new operation to the fib_rules_ops struct; it allows the
suppression of routing decisions if certain criteria are not met by its
results.
The first implemented constraint is a minimum prefix length added to the
structures of routing rules. If a rule is added with a minimum prefix length
>0, only routes meeting this threshold will be considered. Any other (more
general) routing table entries will be ignored.
When configuring a system with multiple network uplinks and default routes, it
is often convinient to reference the main routing table multiple times - but
omitting the default route. Using this patch and a modified "ip" utility, this
can be achieved by using the following command sequence:
$ ip route add table secuplink default via 10.42.23.1
$ ip rule add pref 100 table main prefixlength 1
$ ip rule add pref 150 fwmark 0xA table secuplink
With this setup, packets marked 0xA will be processed by the additional routing
table "secuplink", but only if no suitable route in the main routing table can
be found. By using a minimal prefixlength of 1, the default route (/0) of the
table "main" is hidden to packets processed by rule 100; packets traveling to
destinations with more specific routing entries are processed as usual.
Signed-off-by: Stefan Tomanek <stefan.tomanek@wertarbyte.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/fib_rules.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c index 21735440c44a..2ef5040c99c8 100644 --- a/net/core/fib_rules.c +++ b/net/core/fib_rules.c @@ -226,6 +226,9 @@ jumped: else err = ops->action(rule, fl, flags, arg); + if (!err && ops->suppress && ops->suppress(rule, arg)) + continue; + if (err != -EAGAIN) { if ((arg->flags & FIB_LOOKUP_NOREF) || likely(atomic_inc_not_zero(&rule->refcnt))) { @@ -337,6 +340,8 @@ static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh) rule->action = frh->action; rule->flags = frh->flags; rule->table = frh_get_table(frh, tb); + if (tb[FRA_TABLE_PREFIXLEN_MIN]) + rule->table_prefixlen_min = nla_get_u8(tb[FRA_TABLE_PREFIXLEN_MIN]); if (!tb[FRA_PRIORITY] && ops->default_pref) rule->pref = ops->default_pref(ops); @@ -523,6 +528,7 @@ static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops, + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */ + nla_total_size(4) /* FRA_PRIORITY */ + nla_total_size(4) /* FRA_TABLE */ + + nla_total_size(1) /* FRA_TABLE_PREFIXLEN_MIN */ + nla_total_size(4) /* FRA_FWMARK */ + nla_total_size(4); /* FRA_FWMASK */ @@ -548,6 +554,8 @@ static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule, frh->table = rule->table; if (nla_put_u32(skb, FRA_TABLE, rule->table)) goto nla_put_failure; + if (nla_put_u8(skb, FRA_TABLE_PREFIXLEN_MIN, rule->table_prefixlen_min)) + goto nla_put_failure; frh->res1 = 0; frh->res2 = 0; frh->action = rule->action; |