Windows: Add conntrack dump and flush support in userspace

Modify dpif-netlink.c and netlink-conntrack.c to send down dump and flush command
to Windows datapath. Include netlink-conntrack.c and netlink-conntrack.h
in automake.mk for Windows binaries.

Windows currently supports only NETLINK_GENERIC port. In order to support
the NETLINK_NETFILTER messages, the port id is being overwritten to
NETLINK_GENERIC on Windows and datapath has been updated to support the
new message format.

Signed-off-by: Sairam Venugopal <vsairam@vmware.com>
Acked-by: Paul-Daniel Boca <pboca@cloudbasesolutions.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Signed-off-by: Gurucharan Shetty <guru@ovn.org>

lib/automake.mk

@@ -372,6 +372,8 @@ lib_libopenvswitch_la_SOURCES += \
 	lib/dpif-netlink.c \
 	lib/dpif-netlink.h \
 	lib/netdev-windows.c \
+	lib/netlink-conntrack.c \
+	lib/netlink-conntrack.h \
 	lib/netlink-notifier.c \
 	lib/netlink-notifier.h \
 	lib/netlink-protocol.h \

lib/dpif-netlink.c

@@ -2274,7 +2274,6 @@ dpif_netlink_get_datapath_version(void)
     return version_str;
 }
 
-#ifdef __linux__
 struct dpif_netlink_ct_dump_state {
     struct ct_dpif_dump_state up;
     struct nl_ct_dump_state *nl_ct_dump;
@@ -2335,7 +2334,6 @@ dpif_netlink_ct_flush(struct dpif *dpif OVS_UNUSED, const uint16_t *zone)
         return nl_ct_flush();
     }
 }
-#endif
 
 const struct dpif_class dpif_netlink_class = {
     "system",
@@ -2377,17 +2375,10 @@ const struct dpif_class dpif_netlink_class = {
     NULL,                       /* enable_upcall */
     NULL,                       /* disable_upcall */
     dpif_netlink_get_datapath_version, /* get_datapath_version */
-#ifdef __linux__
     dpif_netlink_ct_dump_start,
     dpif_netlink_ct_dump_next,
     dpif_netlink_ct_dump_done,
-    dpif_netlink_ct_flush,
-#else
-    NULL,                       /* ct_dump_start */
-    NULL,                       /* ct_dump_next */
-    NULL,                       /* ct_dump_done */
-    NULL,                       /* ct_flush */
-#endif
+    dpif_netlink_ct_flush
 };
 
 static int
@@ -2442,7 +2433,7 @@ dpif_netlink_is_internal_device(const char *name)
 
     return reply.type == OVS_VPORT_TYPE_INTERNAL;
 }
-
+
 /* Parses the contents of 'buf', which contains a "struct ovs_header" followed
  * by Netlink attributes, into 'vport'.  Returns 0 if successful, otherwise a
  * positive errno value.
@@ -2946,7 +2937,7 @@ dpif_netlink_flow_get_stats(const struct dpif_netlink_flow *flow,
     stats->used = flow->used ? get_32aligned_u64(flow->used) : 0;
     stats->tcp_flags = flow->tcp_flags ? *flow->tcp_flags : 0;
 }
-
+
 /* Logs information about a packet that was recently lost in 'ch' (in
  * 'dpif_'). */
 static void

lib/netlink-conntrack.c

@@ -75,6 +75,14 @@ static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
 #define IPS_UNTRACKED_BIT 12
 #define IPS_UNTRACKED (1 << IPS_UNTRACKED_BIT)
 
+#ifdef _WIN32
+#ifdef NETLINK_NETFILTER
+#undef NETLINK_NETFILTER
+#endif
+/* Reuse same socket for nfgenmsg and genlmsghdr in Windows*/
+#define NETLINK_NETFILTER       NETLINK_GENERIC
+#endif
+
 static const struct nl_policy nfnlgrp_conntrack_policy[] = {
     [CTA_TUPLE_ORIG] = { .type = NL_A_NESTED, .optional = false },
     [CTA_TUPLE_REPLY] = { .type = NL_A_NESTED, .optional = false },
@@ -118,7 +126,7 @@ struct nl_ct_dump_state {
     bool filter_zone;
     uint16_t zone;
 };
-
+
 /* Conntrack netlink dumping. */
 
 /* Initialize a conntrack netlink dump. */
@@ -200,7 +208,7 @@ nl_ct_dump_done(struct nl_ct_dump_state *state)
     free(state);
     return error;
 }
-
+
 /* Format conntrack event 'entry' of 'type' to 'ds'. */
 void
 nl_ct_format_event_entry(const struct ct_dpif_entry *entry,
@@ -235,6 +243,26 @@ nl_ct_flush(void)
     return err;
 }
 
+#ifdef _WIN32
+int
+nl_ct_flush_zone(uint16_t flush_zone)
+{
+    /* Windows can flush a specific zone */
+    struct ofpbuf buf;
+    int err;
+
+    ofpbuf_init(&buf, NL_DUMP_BUFSIZE);
+
+    nl_msg_put_nfgenmsg(&buf, 0, AF_UNSPEC, NFNL_SUBSYS_CTNETLINK,
+                        IPCTNL_MSG_CT_DELETE, NLM_F_REQUEST);
+    nl_msg_put_be16(&buf, CTA_ZONE, flush_zone);
+
+    err = nl_transact(NETLINK_NETFILTER, &buf, NULL);
+    ofpbuf_uninit(&buf);
+
+    return err;
+}
+#else
 int
 nl_ct_flush_zone(uint16_t flush_zone)
 {
@@ -299,7 +327,8 @@ nl_ct_flush_zone(uint16_t flush_zone)
      * have a master connection anymore */
     return 0;
 }
-
+#endif
+
 /* Conntrack netlink parsing. */
 
 static bool
@@ -788,7 +817,7 @@ nl_ct_parse_entry(struct ofpbuf *buf, struct ct_dpif_entry *entry,
 
     return true;
 }
-
+
 /* NetFilter utility functions. */
 
 /* Puts a nlmsghdr and nfgenmsg at the beginning of 'msg', which must be
@@ -826,4 +855,8 @@ nl_msg_put_nfgenmsg(struct ofpbuf *msg, size_t expected_payload,
     nfm->nfgen_family = family;
     nfm->version = NFNETLINK_V0;
     nfm->res_id = 0;
+#ifdef _WIN32
+    /* nfgenmsg contains ovsHdr padding in windows */
+    nfm->ovsHdr.dp_ifindex = 0;
+#endif
 }