On 9/17/20 10:41 AM, Eelco Chaudron wrote:
Currently, userspace conntrack only tracks TCP, UDP, and ICMP, and
all
other IP protocols are discarded, and the +inv state is returned.
This
is not in line with the kernel conntrack. Where if no L4 information
can
be extracted it's treated as generic L3. The change below mimics the
behavior of the kernel.
Signed-off-by: Eelco Chaudron <[email protected]>
---
v2: Small style fix suggested by Aaron Conole.
lib/conntrack-private.h | 3 +++
lib/conntrack.c | 29 +++++++++++++++++++----------
tests/system-traffic.at | 29 +++++++++++++++++++++++++++++
3 files changed, 51 insertions(+), 10 deletions(-)
Hi, Eelco. Thanks for the patch!
Could you, please, add a NEWS entry since this is kind of user-visible
change.
It should be something like:
- Userspace datapath:
* ...
Some small nitpicks inline. :)
diff --git a/lib/conntrack-private.h b/lib/conntrack-private.h
index 9a8ca39..85329e8 100644
--- a/lib/conntrack-private.h
+++ b/lib/conntrack-private.h
@@ -59,6 +59,9 @@ struct conn_key {
uint8_t nw_proto;
};
+/* Verify that nw_proto stays uint8_t as it's used to index into
l4_protos[] */
+BUILD_ASSERT_DECL(sizeof(((struct conn_key *)0)->nw_proto) ==
sizeof(uint8_t));
This should be 'MEMBER_SIZEOF(struct conn_key, nw_proto) ==
sizeof(uint8_t)'.
+
/* This is used for alg expectations; an expectation is a
* context created in preparation for establishing a data
* connection. The expectation is created by the control
diff --git a/lib/conntrack.c b/lib/conntrack.c
index 0cbc8f6..3597112 100644
--- a/lib/conntrack.c
+++ b/lib/conntrack.c
@@ -143,12 +143,7 @@ detect_ftp_ctl_type(const struct conn_lookup_ctx
*ctx,
static void
expectation_clean(struct conntrack *ct, const struct conn_key
*master_key);
-static struct ct_l4_proto *l4_protos[] = {
- [IPPROTO_TCP] = &ct_proto_tcp,
- [IPPROTO_UDP] = &ct_proto_other,
- [IPPROTO_ICMP] = &ct_proto_icmp4,
- [IPPROTO_ICMPV6] = &ct_proto_icmp6,
-};
+static struct ct_l4_proto *l4_protos[UINT8_MAX + 1];
static void
handle_ftp_ctl(struct conntrack *ct, const struct conn_lookup_ctx
*ctx,
@@ -296,6 +291,7 @@ ct_print_conn_info(const struct conn *c, const
char *log_msg,
struct conntrack *
conntrack_init(void)
{
+ static struct ovsthread_once setup_l4_once =
OVSTHREAD_ONCE_INITIALIZER;
struct conntrack *ct = xzalloc(sizeof *ct);
ovs_rwlock_init(&ct->resources_lock);
@@ -322,6 +318,18 @@ conntrack_init(void)
ct->clean_thread = ovs_thread_create("ct_clean",
clean_thread_main, ct);
ct->ipf = ipf_init();
+ /* Initialize the l4 protocols. */
+ if (ovsthread_once_start(&setup_l4_once)) {
+ for (int i = 0; i < ARRAY_SIZE(l4_protos); i++) {
+ l4_protos[i] = &ct_proto_other;
+ }
+ /* IPPROTO_UDP uses ct_proto_other, so no need to initialize
it. */
+ l4_protos[IPPROTO_TCP] = &ct_proto_tcp;
+ l4_protos[IPPROTO_ICMP] = &ct_proto_icmp4;
+ l4_protos[IPPROTO_ICMPV6] = &ct_proto_icmp6;
+
+ ovsthread_once_done(&setup_l4_once);
+ }
return ct;
}
@@ -1970,9 +1978,10 @@ extract_l4(struct conn_key *key, const void
*data, size_t size, bool *related,
return (!related || check_l4_icmp6(key, data, size, l3,
validate_checksum))
&& extract_l4_icmp6(key, data, size, related);
- } else {
- return false;
}
+
+ /* For all other protocols we do not have L4 keys, so keep them
zero */
Period in the end of a comment.
+ return true;
}
static bool
@@ -2255,8 +2264,8 @@ nat_select_range_tuple(struct conntrack *ct,
const struct conn *conn,
conn->nat_info->nat_action & NAT_ACTION_SRC_PORT
? true : false;
union ct_addr first_addr = ct_addr;
- bool pat_enabled = conn->key.nw_proto != IPPROTO_ICMP &&
- conn->key.nw_proto != IPPROTO_ICMPV6;
+ bool pat_enabled = conn->key.nw_proto == IPPROTO_TCP ||
+ conn->key.nw_proto == IPPROTO_UDP;
while (true) {
if (conn->nat_info->nat_action & NAT_ACTION_SRC) {
diff --git a/tests/system-traffic.at b/tests/system-traffic.at
index 3ed03d9..b7aca93 100644
--- a/tests/system-traffic.at
+++ b/tests/system-traffic.at
@@ -2341,6 +2341,35 @@ NXST_FLOW reply:
OVS_TRAFFIC_VSWITCHD_STOP
AT_CLEANUP
+AT_SETUP([conntrack - generic IP protocol])
+CHECK_CONNTRACK()
+OVS_TRAFFIC_VSWITCHD_START()
+AT_CHECK([ovs-appctl vlog/set dpif:dbg dpif_netdev:dbg
ofproto_dpif_upcall:dbg])
+
+ADD_NAMESPACES(at_ns0, at_ns1)
+
+ADD_VETH(p0, at_ns0, br0, "10.1.1.1/24")
+ADD_VETH(p1, at_ns1, br0, "10.1.1.2/24")
+
+AT_DATA([flows.txt], [dnl
+table=0, priority=1,action=drop
+table=0, priority=10,arp,action=normal
+table=0, priority=100,ip,action=ct(table=1)
+table=1,
priority=100,in_port=1,ip,ct_state=+trk+new,action=ct(commit)
+table=1, priority=100,in_port=1,ct_state=+trk+est,action=normal
+])
+
+AT_CHECK([ovs-ofctl --bundle add-flows br0 flows.txt])
+
+AT_CHECK([ovs-ofctl -O OpenFlow13 packet-out br0 "in_port=1
packet=01005e00001200005e000101080045c0002800000000ff7019cdc0a8001ee0000012210164010001ba52c0a800010000000000000000000000000000
actions=resubmit(,0)"])
+
+AT_CHECK([ovs-appctl dpctl/dump-conntrack | grep
"orig=.src=192\.168\.0\.30,"], [], [dnl
+112,orig=(src=192.168.0.30,dst=224.0.0.18,sport=0,dport=0),reply=(src=224.0.0.18,dst=192.168.0.30,sport=0,dport=0)
+])
+
+OVS_TRAFFIC_VSWITCHD_STOP
+AT_CLEANUP
+
AT_SETUP([conntrack - ICMP related])
AT_SKIP_IF([test $HAVE_NC = no])
CHECK_CONNTRACK()
