ofproto-dpif: Add -generate option to ofproto/trace command.

2 files changed, 25 insertions, 9 deletions

diff --git a/ofproto/ofproto-dpif.c b/ofproto/ofproto-dpif.c
index dfdaaa299..7174748b5 100644
--- a/ofproto/ofproto-dpif.c
+++ b/ofproto/ofproto-dpif.c
@@ -4099,8 +4099,8 @@ ofproto_unixctl_trace(struct unixctl_conn *conn, const char *args_,
     arg1 = strtok_r(NULL, " ", &save_ptr);
     arg2 = strtok_r(NULL, " ", &save_ptr);
     arg3 = strtok_r(NULL, "", &save_ptr); /* Get entire rest of line. */
-    if (dpname && arg1 && !arg2 && !arg3) {
-        /* ofproto/trace dpname flow */
+    if (dpname && arg1 && (!arg2 || !strcmp(arg2, "-generate")) && !arg3) {
+        /* ofproto/trace dpname flow [-generate] */
         int error;
 
         /* Convert string to datapath key. */
@@ -4117,6 +4117,12 @@ ofproto_unixctl_trace(struct unixctl_conn *conn, const char *args_,
             unixctl_command_reply(conn, 501, "Invalid flow");
             goto exit;
         }
+
+        /* Generate a packet, if requested. */
+        if (arg2) {
+            packet = ofpbuf_new(0);
+            flow_compose(packet, &flow);
+        }
     } else if (dpname && arg1 && arg2 && arg3) {
         /* ofproto/trace dpname tun_id in_port packet */
         uint16_t in_port;
diff --git a/ofproto/ofproto-unixctl.man b/ofproto/ofproto-unixctl.man
index 06db7e04d..2cf7bfaa8 100644
--- a/ofproto/ofproto-unixctl.man
+++ b/ofproto/ofproto-unixctl.man
@@ -7,12 +7,12 @@ Lists the names of the running ofproto instances.  These are the names
 that may be used on \fBofproto/trace\fR.
 .
 .IP "\fBofproto/trace \fIswitch tun_id in_port packet\fR"
-Traces the path of an imaginary packet through \fIswitch\fR.  The
-arguments are:
+.IQ "\fBofproto/trace \fIswitch odp_flow \fB\-generate\fR"
+Traces the path of an imaginary packet through \fIswitch\fR.  Both
+forms require \fIswitch\fR, the switch on which the packet arrived
+(one of those listed by \fBofproto/list\fR).  The first form specifies
+a packet's contents explicitly:
 .RS
-.IP "\fIswitch\fR"
-The switch on which the packet arrived (one of those listed by
-\fBofproto/list\fR).
 .IP "\fItun_id\fR"
 The tunnel ID on which the packet arrived.  Use
 \fB0\fR if the packet did not arrive through a tunnel.
@@ -27,9 +27,18 @@ by hand, so the \fBovs\-pcap\fR(1) and \fBovs\-tcpundump\fR(1)
 utilities provide easier ways.
 .RE
 .IP
+The second form specifies the packet's contents implicitly:
+.RS
+.IP "\fIodp_flow\fR"
+A flow in the form printed by \fBovs\-dpctl\fR(8)'s \fBdump\-flows\fR
+command.  This is not an OpenFlow flow: besides other differences, it
+never contains wildcards.  \fB\*(PN\fR generates an arbitrary packet
+that has the specified \fIodp_flow\fR.
+.RE
+.IP
 \fB\*(PN\fR will respond with extensive information on how the packet
 would be handled if it were to be received.  The packet will not
-actually be sent.
+actually be sent, but side effects such as MAC learning will occur.
 .
 .IP "\fBofproto/trace \fIswitch odp_flow\fR"
 Traces the path of a packet in an imaginary flow through
@@ -46,7 +55,8 @@ never contains wildcards.
 .IP
 \fB\*(PN\fR will respond with extensive information on how a packet
 in \fIodp_flow\fR would be handled if it were received by
-\fIswitch\fR.  No packet will actually be sent.
+\fIswitch\fR.  No packet will actually be sent.  Some side effects may
+occur, but MAC learning in particular will not.
 .IP
 This form of \fBofproto/trace\fR cannot determine the complete set of
 datapath actions in some corner cases.  If the results say that this