/*
* This module implements printing of the very basic (version-independent)
* OpenFlow header and iteration over OpenFlow messages. It is intended for
* dispatching of version-specific OpenFlow message decoding.
*
*
* Copyright (c) 2013 The TCPDUMP project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
void
of_bitmap_print(netdissect_options *ndo,
const struct tok *t, const uint32_t v, const uint32_t u)
{
/* Assigned bits? */
if (v & ~u)
ND_PRINT(" (%s)", bittok2str(t, "", v));
/* Unassigned bits? */
if (v & u)
ND_PRINT(" (bogus)");
}
void
of_data_print(netdissect_options *ndo,
const u_char *cp, const u_int len)
{
if (len == 0)
return;
/* data */
ND_PRINT("\n\t data (%u octets)", len);
if (ndo->ndo_vflag >= 2)
hex_and_ascii_print(ndo, "\n\t ", cp, len);
else
ND_TCHECK_LEN(cp, len);
}
static void
of_message_print(netdissect_options *ndo,
const u_char *cp, uint16_t len,
const struct of_msgtypeinfo *mti)
{
/*
* Here "cp" and "len" stand for the message part beyond the common
* OpenFlow 1.0 header, if any.
*
* Most message types are longer than just the header, and the length
* constraints may be complex. When possible, validate the constraint
* completely here (REQ_FIXLEN), otherwise check that the message is
* long enough to begin the decoding (REQ_MINLEN) and have the
* type-specific function do any remaining validation.
*/
if (!mti)
goto tcheck_remainder;
if ((mti->req_what == REQ_FIXLEN && len != mti->req_value) ||
(mti->req_what == REQ_MINLEN && len < mti->req_value))
goto invalid;
if (!ndo->ndo_vflag || !mti->decoder)
goto tcheck_remainder;
/* Print a TCP segment worth of OpenFlow messages presuming the segment begins
* on a message boundary. */
void
openflow_print(netdissect_options *ndo, const u_char *cp, u_int len)
{
ndo->ndo_protocol = "openflow";
ND_PRINT(": OpenFlow");
while (len) {
/* Print a single OpenFlow message. */
uint8_t version, type;
uint16_t length;
const struct of_msgtypeinfo *mti;
/* version */
version = GET_U_1(cp);
OF_FWD(1);
ND_PRINT("\n\tversion %s",
tok2str(ofver_str, "unknown (0x%02x)", version));
/* type */
if (len < 1)
goto partial_header;
type = GET_U_1(cp);
OF_FWD(1);
mti =
version == OF_VER_1_0 ? of10_identify_msgtype(type) :
version == OF_VER_1_3 ? of13_identify_msgtype(type) :
NULL;
if (mti && mti->name)
ND_PRINT(", type %s", mti->name);
else
ND_PRINT(", type unknown (0x%02x)", type);
/* length */
if (len < 2)
goto partial_header;
length = GET_BE_U_2(cp);
OF_FWD(2);
ND_PRINT(", length %u%s", length,
length < OF_HEADER_FIXLEN ? " (too short!)" : "");
/* xid */
if (len < 4)
goto partial_header;
ND_PRINT(", xid 0x%08x", GET_BE_U_4(cp));
OF_FWD(4);
/*
* When a TCP packet can contain several protocol messages,
* and at the same time a protocol message can span several
* TCP packets, decoding an incomplete message at the end of
* a TCP packet requires attention to detail in this loop.
*
* Message length includes the header length and a message
* always includes the basic header. A message length underrun
* fails decoding of the rest of the current packet. At the
* same time, try decoding as much of the current message as
* possible even when it does not end within the current TCP
* segment.
*
* Specifically, to try to process the message body in this
* iteration do NOT require the header "length" to be small
* enough for the full declared OpenFlow message to fit into
* the remainder of the declared TCP segment, same as the full
* declared TCP segment is not required to fit into the
* captured packet buffer.
*
* But DO require the same at the end of this iteration to
* decrement "len" and to proceed to the next iteration.
* (Ideally the declared TCP payload end will be at or after
* the captured packet buffer end, but stay safe even when
* that's somehow not the case.)
*/
if (length < OF_HEADER_FIXLEN)
goto invalid;
