From: Ben Pfaff <blp@nicira.com>
Date: Wed, 15 Feb 2012 01:08:03 +0000 (-0800)
Subject: ofp-util: Add functions for working with OpenFlow 1.1 port numbers.
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7b7503ea627ccd2a0851803ca39c1505f30415d3;p=openvswitch

ofp-util: Add functions for working with OpenFlow 1.1 port numbers.

OpenFlow 1.1 extends port numbers to 32 bits.  Initially we plan to support
only port numbers in the 16-bit range in Open vSwitch.  However the OF1.1
reserved ports have high-valued fixed numbers that require translation to
high fixed values in the 16-bit range for OF1.0.  These new functions
provide this translation.

Nothing uses these functions yet.

Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Ben Pfaff <blp@nicira.com>
---

diff --git a/include/openflow/openflow-1.1.h b/include/openflow/openflow-1.1.h
index 8b407e32..93002af9 100644
--- a/include/openflow/openflow-1.1.h
+++ b/include/openflow/openflow-1.1.h
@@ -54,6 +54,20 @@
 
 #include "openflow/openflow-common.h"
 
-/* Nothing here yet. */
+/* OpenFlow 1.1 uses 32-bit port numbers.  Open vSwitch, for now, uses OpenFlow
+ * 1.0 port numbers internally.  We map them to OpenFlow 1.0 as follows:
+ *
+ * OF1.1                    <=>  OF1.0
+ * -----------------------       ---------------
+ * 0x00000000...0x0000feff  <=>  0x0000...0xfeff  "physical" ports
+ * 0x0000ff00...0xfffffeff  <=>  not supported
+ * 0xffffff00...0xffffffff  <=>  0xff00...0xffff  "reserved" OFPP_* ports
+ *
+ * OFPP11_OFFSET is the value that must be added or subtracted to convert
+ * an OpenFlow 1.0 reserved port number to or from, respectively, the
+ * corresponding OpenFlow 1.1 reserved port number.
+ */
+#define OFPP11_MAX    0xffffff00
+#define OFPP11_OFFSET (OFPP11_MAX - OFPP_MAX)
 
 #endif /* openflow/openflow-1.1.h */
diff --git a/lib/ofp-util.c b/lib/ofp-util.c
index db954220..a60c0a52 100644
--- a/lib/ofp-util.c
+++ b/lib/ofp-util.c
@@ -2692,6 +2692,44 @@ ofputil_frag_handling_from_string(const char *s, enum ofp_config_flags *flags)
     return true;
 }
 
+/* Converts the OpenFlow 1.1+ port number 'ofp11_port' into an OpenFlow 1.0
+ * port number and stores the latter in '*ofp10_port', for the purpose of
+ * decoding OpenFlow 1.1+ protocol messages.  Returns 0 if successful,
+ * otherwise an OFPERR_* number.
+ *
+ * See the definition of OFP11_MAX for an explanation of the mapping. */
+enum ofperr
+ofputil_port_from_ofp11(ovs_be32 ofp11_port, uint16_t *ofp10_port)
+{
+    uint32_t ofp11_port_h = ntohl(ofp11_port);
+
+    if (ofp11_port_h < OFPP_MAX) {
+        *ofp10_port = ofp11_port_h;
+        return 0;
+    } else if (ofp11_port_h >= OFPP11_MAX) {
+        *ofp10_port = ofp11_port_h - OFPP11_OFFSET;
+        return 0;
+    } else {
+        VLOG_WARN_RL(&bad_ofmsg_rl, "port %"PRIu32" is outside the supported "
+                     "range 0 through %d or 0x%"PRIx32" through 0x%"PRIx32,
+                     ofp11_port_h, OFPP_MAX - 1,
+                     (uint32_t) OFPP11_MAX, UINT32_MAX);
+        return OFPERR_OFPBAC_BAD_OUT_PORT;
+    }
+}
+
+/* Returns the OpenFlow 1.1+ port number equivalent to the OpenFlow 1.0 port
+ * number 'ofp10_port', for encoding OpenFlow 1.1+ protocol messages.
+ *
+ * See the definition of OFP11_MAX for an explanation of the mapping. */
+ovs_be32
+ofputil_port_to_ofp11(uint16_t ofp10_port)
+{
+    return htonl(ofp10_port < OFPP_MAX
+                 ? ofp10_port
+                 : ofp10_port + OFPP11_OFFSET);
+}
+
 /* Checks that 'port' is a valid output port for the OFPAT_OUTPUT action, given
  * that the switch will never have more than 'max_ports' ports.  Returns 0 if
  * 'port' is valid, otherwise an OpenFlow return code. */
diff --git a/lib/ofp-util.h b/lib/ofp-util.h
index c2b0e2a0..980f5eaf 100644
--- a/lib/ofp-util.h
+++ b/lib/ofp-util.h
@@ -102,6 +102,9 @@ enum ofputil_msg_code ofputil_msg_type_code(const struct ofputil_msg_type *);
 const char *ofputil_msg_type_name(const struct ofputil_msg_type *);
 
 /* Port numbers. */
+enum ofperr ofputil_port_from_ofp11(ovs_be32 ofp11_port, uint16_t *ofp10_port);
+ovs_be32 ofputil_port_to_ofp11(uint16_t ofp10_port);
+
 enum ofperr ofputil_check_output_port(uint16_t ofp_port, int max_ports);
 bool ofputil_port_from_string(const char *, uint16_t *port);
 void ofputil_format_port(uint16_t port, struct ds *);