ovs-dpctl: Add a 'filter' option to match wildcarded 'dump-flows'.

With mega-flows, many flows in the kernel datapath are wildcarded.
For someone that is debugging a system and wants to find a particular
flow and its actions, it is a little hard to zero-in on the flow
because some fields are wildcarded.

With the filter='$filter' option, we can now filter on the o/p
of 'ovs-dpctl dump-flows'.

Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>

2 files changed, 54 insertions, 3 deletions

diff --git a/utilities/ovs-dpctl.8.in b/utilities/ovs-dpctl.8.in
index 5c0157028..35d1be590 100644
--- a/utilities/ovs-dpctl.8.in
+++ b/utilities/ovs-dpctl.8.in
@@ -118,11 +118,19 @@ exactly one datapath exists, in which case that datapath is the
 default.  When multiple datapaths exist, then a datapath name is
 required.
 .
-.IP "[\fB\-m \fR| \fB\-\-more\fR] \fBdump\-flows\fR [\fIdp\fR]"
+.IP "[\fB\-m \fR| \fB\-\-more\fR] \fBdump\-flows\fR [\fIdp\fR] [\fBfilter=\fIfilter\fR]"
 Prints to the console all flow entries in datapath \fIdp\fR's flow
 table.  Without \fB\-m\fR or \fB\-\-more\fR, output omits match fields
 that a flow wildcards entirely; with \fB\-m\fR or \fB\-\-more\fR,
 output includes all wildcarded fields.
+.IP
+If \fBfilter=\fIfilter\fR is specified, only displays the flows
+that match the \fIfilter\fR. \fIfilter\fR is a flow in the form similiar
+to that accepted by \fBovs\-ofctl\fR(8)'s \fBadd\-flow\fR command. (This is
+not an OpenFlow flow: besides other differences, it never contains wildcards.)
+The \fIfilter\fR is also useful to match wildcarded fields in the datapath
+flow. As an example, \fBfilter='tcp,tp_src=100'\fR will match the
+datapath flow containing '\fBtcp(src=80/0xff00,dst=8080/0xff)\fR'.
 .
 .IP "\fBadd\-flow\fR [\fIdp\fR] \fIflow actions\fR"
 .IQ "[\fB\-\-clear\fR] [\fB\-\-may-create\fR] [\fB\-s\fR | \fB\-\-statistics\fR] \fBmod\-flow\fR [\fIdp\fR] \fIflow actions\fR"
diff --git a/utilities/ovs-dpctl.c b/utilities/ovs-dpctl.c
index 4fb02dda4..e11e102e3 100644
--- a/utilities/ovs-dpctl.c
+++ b/utilities/ovs-dpctl.c
@@ -36,9 +36,11 @@
 #include "dpif.h"
 #include "dynamic-string.h"
 #include "flow.h"
+#include "match.h"
 #include "netdev.h"
 #include "netlink.h"
 #include "odp-util.h"
+#include "ofp-parse.h"
 #include "ofpbuf.h"
 #include "packets.h"
 #include "shash.h"
@@ -746,20 +748,38 @@ dpctl_dump_flows(int argc, char *argv[])
     struct dpif_port dpif_port;
     struct dpif_port_dump port_dump;
     struct hmap portno_names;
+    struct simap names_portno;
     size_t actions_len;
     struct dpif *dpif;
     size_t key_len;
     size_t mask_len;
     struct ds ds;
-    char *name;
+    char *name, *error, *filter = NULL;
+    struct flow flow_filter;
+    struct flow_wildcards wc_filter;
 
+    if (argc > 1 && !strncmp(argv[argc - 1], "filter=", 7)) {
+        filter = xstrdup(argv[--argc] + 7);
+    }
     name = (argc == 2) ? xstrdup(argv[1]) : get_one_dp();
+
     run(parsed_dpif_open(name, false, &dpif), "opening datapath");
     free(name);
 
     hmap_init(&portno_names);
+    simap_init(&names_portno);
     DPIF_PORT_FOR_EACH (&dpif_port, &port_dump, dpif) {
         odp_portno_names_set(&portno_names, dpif_port.port_no, dpif_port.name);
+        simap_put(&names_portno, dpif_port.name,
+                  odp_to_u32(dpif_port.port_no));
+    }
+
+    if (filter) {
+        error = parse_ofp_exact_flow(&flow_filter, &wc_filter.masks, filter,
+                                     &names_portno);
+        if (error) {
+            ovs_fatal(0, "Failed to parse filter (%s)", error);
+        }
     }
 
     ds_init(&ds);
@@ -767,6 +787,26 @@ dpctl_dump_flows(int argc, char *argv[])
     while (dpif_flow_dump_next(&flow_dump, &key, &key_len,
                                &mask, &mask_len,
                                &actions, &actions_len, &stats)) {
+        if (filter) {
+            struct flow flow;
+            struct flow_wildcards wc;
+            struct match match, match_filter;
+            struct minimatch minimatch;
+
+            odp_flow_key_to_flow(key, key_len, &flow);
+            odp_flow_key_to_mask(mask, mask_len, &wc.masks, &flow);
+            match_init(&match, &flow, &wc);
+
+            match_init(&match_filter, &flow_filter, &wc);
+            match_init(&match_filter, &match_filter.flow, &wc_filter);
+            minimatch_init(&minimatch, &match_filter);
+
+            if (!minimatch_matches_flow(&minimatch, &match.flow)) {
+                minimatch_destroy(&minimatch);
+                continue;
+            }
+            minimatch_destroy(&minimatch);
+        }
         ds_clear(&ds);
         odp_flow_format(key, key_len, mask, mask_len, &portno_names, &ds,
                         verbosity);
@@ -778,8 +818,11 @@ dpctl_dump_flows(int argc, char *argv[])
         printf("%s\n", ds_cstr(&ds));
     }
     dpif_flow_dump_done(&flow_dump);
+
+    free(filter);
     odp_portno_names_destroy(&portno_names);
     hmap_destroy(&portno_names);
+    simap_destroy(&names_portno);
     ds_destroy(&ds);
     dpif_close(dpif);
 }
@@ -1166,7 +1209,7 @@ static const struct command all_commands[] = {
     { "set-if", 2, INT_MAX, dpctl_set_if },
     { "dump-dps", 0, 0, dpctl_dump_dps },
     { "show", 0, INT_MAX, dpctl_show },
-    { "dump-flows", 0, 1, dpctl_dump_flows },
+    { "dump-flows", 0, 2, dpctl_dump_flows },
     { "add-flow", 2, 3, dpctl_add_flow },
     { "mod-flow", 2, 3, dpctl_mod_flow },
     { "del-flow", 1, 2, dpctl_del_flow },