ovs-dpctl: Allow requesting the port number from "add-if" command.

The datapath port number influences the OpenFlow port number in
ovs-vswitchd.  The new "port_no" option for the "add-if" command allows
the user to request a specific datapath port number.

Feature #12642

Signed-off-by: Justin Pettit <[email protected]>

NEWS

@@ -9,6 +9,9 @@ post-v1.8.0
     - OpenFlow:
       - Allow bitwise masking for SHA and THA fields in ARP, SLL and TLL
         fields in IPv6 neighbor discovery messages, and IPv6 flow label.
+    - ovs-dpctl
+      - Support requesting the port number with the "port_no" option in
+        the "add-if" command.
 
 
 v1.8.0 - xx xxx xxxx

utilities/ovs-dpctl.8.in

@@ -66,6 +66,9 @@ The following options are currently supported:
 .RS
 .IP "\fBtype=\fItype\fR"
 Specifies the type of port to add.  The default type is \fBsystem\fR.
+.IP "\fBport_no=\fIport\fR"
+Requests a specific port number within the datapath.  If this option is
+not specified then one will be automatically assigned.
 .IP "\fIkey\fB=\fIvalue\fR"
 Adds an arbitrary key-value option to the port's configuration.
 .RE
@@ -78,9 +81,9 @@ Reconfigures each \fIport\fR in \fIdp\fR as specified.  An
 \fIoption\fR of the form \fIkey\fB=\fIvalue\fR adds the specified
 key-value option to the port or overrides an existing key's value.  An
 \fIoption\fR of the form \fIkey\fB=\fR, that is, without a value,
-deletes the key-value named \fIkey\fR.  The type of a port cannot be
-changed, so \fBtype=\fItype\fR is only allowed if \fItype\fR is the
-port's existing type.
+deletes the key-value named \fIkey\fR.  The type and port number of a
+port cannot be changed, so \fBtype\fR and \fBport_no\fR are only allowed if
+they match the existing configuration.
 .TP
 \fBdel\-if \fIdp netdev\fR...
 Removes each \fInetdev\fR from the list of network devices datapath

utilities/ovs-dpctl.c

@@ -248,6 +248,7 @@ dpctl_add_if(int argc OVS_UNUSED, char *argv[])
         char *save_ptr = NULL;
         struct netdev *netdev = NULL;
         struct smap args;
+        uint16_t port_no = UINT16_MAX;
         char *option;
         int error;
 
@@ -273,6 +274,8 @@ dpctl_add_if(int argc OVS_UNUSED, char *argv[])
 
             if (!strcmp(key, "type")) {
                 type = value;
+            } else if (!strcmp(key, "port_no")) {
+                port_no = atoi(value);
             } else if (!smap_add_once(&args, key, value)) {
                 ovs_error(0, "duplicate \"%s\" option", key);
             }
@@ -290,7 +293,7 @@ dpctl_add_if(int argc OVS_UNUSED, char *argv[])
             goto next;
         }
 
-        error = dpif_port_add(dpif, netdev, NULL);
+        error = dpif_port_add(dpif, netdev, &port_no);
         if (error) {
             ovs_error(error, "adding %s to %s failed", name, argv[1]);
             goto next;
@@ -325,6 +328,7 @@ dpctl_set_if(int argc, char *argv[])
         char *type = NULL;
         const char *name;
         struct smap args;
+        uint32_t port_no;
         char *option;
         int error;
 
@@ -342,6 +346,7 @@ dpctl_set_if(int argc, char *argv[])
             goto next;
         }
         type = xstrdup(dpif_port.type);
+        port_no = dpif_port.port_no;
         dpif_port_destroy(&dpif_port);
 
         /* Retrieve its existing configuration. */
@@ -375,6 +380,13 @@ dpctl_set_if(int argc, char *argv[])
                               name, type, value);
                     failure = true;
                 }
+            } else if (!strcmp(key, "port_no")) {
+                if (port_no != atoi(value)) {
+                    ovs_error(0, "%s: can't change port number from "
+                              "%"PRIu32" to %d",
+                              name, port_no, atoi(value));
+                    failure = true;
+                }
             } else if (value[0] == '\0') {
                 smap_remove(&args, key);
             } else {