From: Roopa Prabhu <ro...@cumulusnetworks.com>
Dissect flow in fwd path if fib rules require it. Controlled by
a flag to avoid penatly for the common case. Flag is set when fib
rules with sport, dport and proto match that require flow dissect
are installed. Also passes the dissected hash keys to the multipath
hash function when applicable to avoid dissecting the flow again.
icmp packets will continue to use inner header for hash
calculations (Thanks to Nikolay Aleksandrov for some review here).
Signed-off-by: Roopa Prabhu <ro...@cumulusnetworks.com>
---
include/net/ip_fib.h | 2 +-
include/net/netns/ipv4.h | 1 +
net/ipv4/fib_rules.c | 13 ++++++++++---
net/ipv4/fib_semantics.c | 2 +-
net/ipv4/route.c | 49 +++++++++++++++++++++++++++++++++++-------------
5 files changed, 49 insertions(+), 18 deletions(-)
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index f805243..5ada772 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -371,7 +371,7 @@ int fib_sync_up(struct net_device *dev, unsigned int
nh_flags);
#ifdef CONFIG_IP_ROUTE_MULTIPATH
int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4,
- const struct sk_buff *skb);
+ const struct sk_buff *skb, struct flow_keys *flkeys);
#endif
void fib_select_multipath(struct fib_result *res, int hash);
void fib_select_path(struct net *net, struct fib_result *res,
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 44668c2..87b8fdc 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -52,6 +52,7 @@ struct netns_ipv4 {
#ifdef CONFIG_IP_MULTIPLE_TABLES
struct fib_rules_ops *rules_ops;
bool fib_has_custom_rules;
+ bool fib_rules_require_fldissect;
struct fib_table __rcu *fib_main;
struct fib_table __rcu *fib_default;
#endif
diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
index f204c85..fb6a637 100644
--- a/net/ipv4/fib_rules.c
+++ b/net/ipv4/fib_rules.c
@@ -256,14 +256,20 @@ static int fib4_rule_configure(struct fib_rule *rule,
struct sk_buff *skb,
net->ipv4.fib_num_tclassid_users++;
}
#endif
- if (tb[FRA_PROTO])
+ if (tb[FRA_PROTO]) {
rule4->proto = nla_get_u8(tb[FRA_PROTO]);
+ net->ipv4.fib_rules_require_fldissect = true;
+ }
- if (tb[FRA_DPORT])
+ if (tb[FRA_DPORT]) {
rule4->dport = nla_get_be16(tb[FRA_DPORT]);
+ net->ipv4.fib_rules_require_fldissect = true;
+ }
- if (tb[FRA_SPORT])
+ if (tb[FRA_SPORT]) {
rule4->sport = nla_get_be16(tb[FRA_SPORT]);
+ net->ipv4.fib_rules_require_fldissect = true;
+ }
rule4->src_len = frh->src_len;
rule4->srcmask = inet_make_mask(rule4->src_len);
@@ -431,6 +437,7 @@ int __net_init fib4_rules_init(struct net *net)
goto fail;
net->ipv4.rules_ops = ops;
net->ipv4.fib_has_custom_rules = false;
+ net->ipv4.fib_rules_require_fldissect = false;
return 0;
fail:
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index c586597..88f66e6 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1767,7 +1767,7 @@ void fib_select_path(struct net *net, struct fib_result
*res,
#ifdef CONFIG_IP_ROUTE_MULTIPATH
if (res->fi->fib_nhs > 1 && oif_check) {
- int h = fib_multipath_hash(res->fi, fl4, skb);
+ int h = fib_multipath_hash(res->fi, fl4, skb, NULL);
fib_select_multipath(res, h);
}
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 49cc1c1..8889d5e 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1798,7 +1798,7 @@ static void ip_multipath_l3_keys(const struct sk_buff
*skb,
/* if skb is set it will be used and fl4 can be NULL */
int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4,
- const struct sk_buff *skb)
+ const struct sk_buff *skb, struct flow_keys *flkeys)
{
struct net *net = fi->fib_net;
struct flow_keys hash_keys;
@@ -1825,12 +1825,20 @@ int fib_multipath_hash(const struct fib_info *fi, const
struct flowi4 *fl4,
if (skb->l4_hash)
return skb_get_hash_raw(skb) >> 1;
memset(&hash_keys, 0, sizeof(hash_keys));
- skb_flow_dissect_flow_keys(skb, &keys, flag);
- hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
- hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
- hash_keys.ports.src = keys.ports.src;
- hash_keys.ports.dst = keys.ports.dst;
- hash_keys.basic.ip_proto = keys.basic.ip_proto;
+ if (flkeys) {
+ hash_keys.addrs.v4addrs.src =
flkeys->addrs.v4addrs.src;
+ hash_keys.addrs.v4addrs.dst =
flkeys->addrs.v4addrs.dst;
+ hash_keys.ports.src = flkeys->ports.src;
+ hash_keys.ports.dst = flkeys->ports.dst;
+ hash_keys.basic.ip_proto =
flkeys->basic.ip_proto;
+ } else {
+ skb_flow_dissect_flow_keys(skb, &keys, flag);
+ hash_keys.addrs.v4addrs.src =
keys.addrs.v4addrs.src;
+ hash_keys.addrs.v4addrs.dst =
keys.addrs.v4addrs.dst;
+ hash_keys.ports.src = keys.ports.src;
+ hash_keys.ports.dst = keys.ports.dst;
+ hash_keys.basic.ip_proto = keys.basic.ip_proto;
+ }
} else {
memset(&hash_keys, 0, sizeof(hash_keys));
hash_keys.control.addr_type =
FLOW_DISSECTOR_KEY_IPV4_ADDRS;
@@ -1852,11 +1860,12 @@ EXPORT_SYMBOL_GPL(fib_multipath_hash);
static int ip_mkroute_input(struct sk_buff *skb,
struct fib_result *res,
struct in_device *in_dev,
- __be32 daddr, __be32 saddr, u32 tos)
+ __be32 daddr, __be32 saddr, u32 tos,
+ struct flow_keys *hkeys)
{
#ifdef CONFIG_IP_ROUTE_MULTIPATH
if (res->fi && res->fi->fib_nhs > 1) {
- int h = fib_multipath_hash(res->fi, NULL, skb);
+ int h = fib_multipath_hash(res->fi, NULL, skb, hkeys);
fib_select_multipath(res, h);
}
@@ -1882,13 +1891,14 @@ static int ip_route_input_slow(struct sk_buff *skb,
__be32 daddr, __be32 saddr,
struct fib_result *res)
{
struct in_device *in_dev = __in_dev_get_rcu(dev);
+ struct flow_keys *flkeys = NULL, _flkeys;
+ struct net *net = dev_net(dev);
struct ip_tunnel_info *tun_info;
- struct flowi4 fl4;
+ int err = -EINVAL;
unsigned int flags = 0;
u32 itag = 0;
struct rtable *rth;
- int err = -EINVAL;
- struct net *net = dev_net(dev);
+ struct flowi4 fl4;
bool do_cache;
/* IP on this device is disabled. */
@@ -1947,6 +1957,19 @@ static int ip_route_input_slow(struct sk_buff *skb,
__be32 daddr, __be32 saddr,
fl4.daddr = daddr;
fl4.saddr = saddr;
fl4.flowi4_uid = sock_net_uid(net, NULL);
+
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+ if (net->ipv4.fib_rules_require_fldissect) {
+ unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
+
+ memset(&_flkeys, 0, sizeof(_flkeys));
+ skb_flow_dissect_flow_keys(skb, &_flkeys, flag);
+ fl4.fl4_sport = _flkeys.ports.src;
+ fl4.fl4_dport = _flkeys.ports.dst;
+ fl4.flowi4_proto = _flkeys.basic.ip_proto;
+ flkeys = &_flkeys;
+ }
+#endif
err = fib_lookup(net, &fl4, res, 0);
if (err != 0) {
if (!IN_DEV_FORWARD(in_dev))
@@ -1972,7 +1995,7 @@ static int ip_route_input_slow(struct sk_buff *skb,
__be32 daddr, __be32 saddr,
if (res->type != RTN_UNICAST)
goto martian_destination;
- err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos);
+ err = ip_mkroute_input(skb, res, in_dev, daddr, saddr, tos, flkeys);
out: return err;
brd_input:
--
2.1.4
