ofp-print: Print the type of truncated messages, when available.

The function ofputil_decode_msg_type_partial() can figure out the type of a truncated OpenFlow message, if the message is long enough that its type can be determined, so we should print this information. This is especially valuable for printing OFPT_ERROR messages, in which the inner OpenFlow message is often truncated to 64 bytes. Signed-off-by: Ben Pfaff <[email protected]>
dkarhi · Jul 20, 2012 · f25b4a8 · f25b4a8
1 parent 0d0c0bb
commit f25b4a8
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Showing 3 changed files with 48 additions and 12 deletions.
diff --git a/lib/ofp-print.c b/lib/ofp-print.c
@@ -1519,6 +1519,14 @@ ofp_print_version(const struct ofp_header *oh,
     ds_put_format(string, " (xid=0x%"PRIx32"):", ntohl(oh->xid));
 }
 
+static void
+ofp_header_to_string__(const struct ofp_header *oh,
+                       const struct ofputil_msg_type *type, struct ds *string)
+{
+    ds_put_cstr(string, ofputil_msg_type_name(type));
+    ofp_print_version(oh, string);
+}
+
 static void
 ofp_to_string__(const struct ofp_header *oh,
                 const struct ofputil_msg_type *type, struct ds *string,
@@ -1527,8 +1535,7 @@ ofp_to_string__(const struct ofp_header *oh,
     enum ofputil_msg_code code;
     const void *msg = oh;
 
-    ds_put_cstr(string, ofputil_msg_type_name(type));
-    ofp_print_version(oh, string);
+    ofp_header_to_string__(oh, type, string);
     code = ofputil_msg_type_code(type);
     switch (code) {
     case OFPUTIL_MSG_INVALID:
@@ -1730,6 +1737,15 @@ ofp_to_string(const void *oh_, size_t len, int verbosity)
         ds_put_format(&string, "OpenFlow packet too short (only %zu bytes):\n",
                       len);
     } else if (ntohs(oh->length) > len) {
+        const struct ofputil_msg_type *type;
+        enum ofperr error;
+
+        error = ofputil_decode_msg_type_partial(oh, len, &type);
+        if (!error) {
+            ofp_header_to_string__(oh, type, &string);
+            ds_put_char(&string, '\n');
+        }
+
         ds_put_format(&string,
                       "(***truncated to %zu bytes from %"PRIu16"***)\n",
                       len, ntohs(oh->length));

diff --git a/tests/ofp-errors.at b/tests/ofp-errors.at
@@ -18,10 +18,28 @@ AT_CLEANUP
 
 AT_SETUP([OFPT_ERROR with type OFPET_BAD_REQUEST - OF1.0])
 AT_KEYWORDS([ofp-print ofp-errors])
-AT_CHECK([ovs-ofctl ofp-print 01010014000000000001000601bbccddeeff0011], [0], [dnl
+AT_CHECK([ovs-ofctl ofp-print 0101001400000000000100060105ccddeeff0011], [0], [dnl
 OFPT_ERROR (xid=0x0): OFPBRC_BAD_LEN
+OFPT_FEATURES_REQUEST (xid=0xeeff0011):
 (***truncated to 8 bytes from 52445***)
-00000000  01 bb cc dd ee ff 00 11-                        |........        |
+00000000  01 05 cc dd ee ff 00 11-                        |........        |
+])
+AT_CLEANUP
+
+AT_SETUP([OFPT_ERROR prints type of truncated inner messages])
+AT_KEYWORDS([ofp-print ofp-errors])
+AT_CHECK([ovs-ofctl ofp-print "0101004c092529d500010006 \
+01 06 00 e0 00 00 00 01 00 00 50 54 00 00 00 01 \
+00 00 01 00 02 00 00 00 00 00 00 87 00 00 0f ff \
+ff fe 50 54 00 00 00 01 62 72 30 00 00 00 00 00 \
+00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 01"], [0], [dnl
+OFPT_ERROR (xid=0x92529d5): OFPBRC_BAD_LEN
+OFPT_FEATURES_REPLY (xid=0x1):
+(***truncated to 64 bytes from 224***)
+00000000  01 06 00 e0 00 00 00 01-00 00 50 54 00 00 00 01 |..........PT....|
+00000010  00 00 01 00 02 00 00 00-00 00 00 87 00 00 0f ff |................|
+00000020  ff fe 50 54 00 00 00 01-62 72 30 00 00 00 00 00 |..PT....br0.....|
+00000030  00 00 00 00 00 00 00 00-00 00 00 01 00 00 00 01 |................|
 ])
 AT_CLEANUP
 
@@ -45,18 +63,20 @@ dnl Error type 3, code 1 is OFPFMFC_OVERLAP in OF1.0
 dnl and OFPBIC_UNSUP_INST in OF1.1, so check that value in both versions.
 AT_SETUP([OFPT_ERROR with type OFPFMFC_OVERLAP - OF1.0])
 AT_KEYWORDS([ofp-print ofp-errors])
-AT_CHECK([ovs-ofctl ofp-print 01010014000000000003000101bbccddeeff0011], [0], [dnl
+AT_CHECK([ovs-ofctl ofp-print 0101001400000000000300010106ccddeeff0011], [0], [dnl
 OFPT_ERROR (xid=0x0): OFPFMFC_OVERLAP
+OFPT_FEATURES_REPLY (xid=0xeeff0011):
 (***truncated to 8 bytes from 52445***)
-00000000  01 bb cc dd ee ff 00 11-                        |........        |
+00000000  01 06 cc dd ee ff 00 11-                        |........        |
 ])
 AT_CLEANUP
 AT_SETUP([OFPT_ERROR with type OFPBIC_UNSUP_INST - OF1.1])
 AT_KEYWORDS([ofp-print ofp-errors])
-AT_CHECK([ovs-ofctl ofp-print 02010014000000000003000102bbccddeeff0011], [0], [dnl
+AT_CHECK([ovs-ofctl ofp-print 0201001400000000000300010206ccddeeff0011], [0], [dnl
 OFPT_ERROR (OF1.1) (xid=0x0): OFPBIC_UNSUP_INST
+OFPT_FEATURES_REPLY (OF1.1) (xid=0xeeff0011):
 (***truncated to 8 bytes from 52445***)
-00000000  02 bb cc dd ee ff 00 11-                        |........        |
+00000000  02 06 cc dd ee ff 00 11-                        |........        |
 ])
 AT_CLEANUP
 

diff --git a/tests/ofp-print.at b/tests/ofp-print.at
@@ -26,17 +26,17 @@ AT_CLEANUP
 
 AT_SETUP([truncated message])
 AT_KEYWORDS([ofp-print])
-AT_CHECK([ovs-ofctl ofp-print 01bbccddeeff0011], [0], [dnl
+AT_CHECK([ovs-ofctl ofp-print 0110ccddeeff0011], [0], [dnl
 (***truncated to 8 bytes from 52445***)
-00000000  01 bb cc dd ee ff 00 11-                        |........        |
+00000000  01 10 cc dd ee ff 00 11-                        |........        |
 ])
 AT_CLEANUP
 
 AT_SETUP([message only uses part of buffer])
 AT_KEYWORDS([ofp-print])
-AT_CHECK([ovs-ofctl ofp-print 01bb0009eeff00112233], [0], [dnl
+AT_CHECK([ovs-ofctl ofp-print 01100009eeff00112233], [0], [dnl
 (***only uses 9 bytes out of 10***)
-00000000  01 bb 00 09 ee ff 00 11-22 33                   |........"3      |
+00000000  01 10 00 09 ee ff 00 11-22 33                   |........"3      |
 ])
 # "
 AT_CLEANUP