1 /* 2 * This module implements printing of the very basic (version-independent) 3 * OpenFlow header and iteration over OpenFlow messages. It is intended for 4 * dispatching of version-specific OpenFlow message decoding. 5 * 6 * 7 * Copyright (c) 2013 The TCPDUMP project 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 22 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 23 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 25 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 26 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 27 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 29 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #define NETDISSECT_REWORKED 34 #ifdef HAVE_CONFIG_H 35 #include "config.h" 36 #endif 37 38 #include <tcpdump-stdinc.h> 39 40 #include "interface.h" 41 #include "extract.h" 42 #include "openflow.h" 43 44 static const char tstr[] = " [|openflow]"; 45 static const char cstr[] = " (corrupt)"; 46 47 #define OF_VER_1_0 0x01 48 49 static void 50 of_header_print(netdissect_options *ndo, const uint8_t version, const uint8_t type, 51 const uint16_t length, const uint32_t xid) { 52 ND_PRINT((ndo, "\n\tversion unknown (0x%02x), type 0x%02x, length %u, xid 0x%08x", 53 version, type, length, xid)); 54 } 55 56 /* Print a single OpenFlow message. */ 57 static const u_char * 58 of_header_body_print(netdissect_options *ndo, const u_char *cp, const u_char *ep) { 59 uint8_t version, type; 60 uint16_t length; 61 uint32_t xid; 62 63 if (ep < cp + OF_HEADER_LEN) 64 goto corrupt; 65 /* version */ 66 ND_TCHECK2(*cp, 1); 67 version = *cp; 68 cp += 1; 69 /* type */ 70 ND_TCHECK2(*cp, 1); 71 type = *cp; 72 cp += 1; 73 /* length */ 74 ND_TCHECK2(*cp, 2); 75 length = EXTRACT_16BITS(cp); 76 cp += 2; 77 /* xid */ 78 ND_TCHECK2(*cp, 4); 79 xid = EXTRACT_32BITS(cp); 80 cp += 4; 81 /* Message length includes the header length and a message always includes 82 * the basic header. A message length underrun fails decoding of the rest of 83 * the current packet. At the same time, try decoding as much of the current 84 * message as possible even when it does not end within the current TCP 85 * segment. */ 86 if (length < OF_HEADER_LEN) { 87 of_header_print(ndo, version, type, length, xid); 88 goto corrupt; 89 } 90 /* Decode known protocol versions further without printing the header (the 91 * type decoding is version-specific. */ 92 switch (version) { 93 case OF_VER_1_0: 94 return of10_header_body_print(ndo, cp, ep, type, length, xid); 95 default: 96 of_header_print(ndo, version, type, length, xid); 97 ND_TCHECK2(*cp, length - OF_HEADER_LEN); 98 return cp + length - OF_HEADER_LEN; /* done with current message */ 99 } 100 101 corrupt: /* fail current packet */ 102 ND_PRINT((ndo, "%s", cstr)); 103 ND_TCHECK2(*cp, ep - cp); 104 return ep; 105 trunc: 106 ND_PRINT((ndo, "%s", tstr)); 107 return ep; 108 } 109 110 /* Print a TCP segment worth of OpenFlow messages presuming the segment begins 111 * on a message boundary. */ 112 void 113 openflow_print(netdissect_options *ndo, const u_char *cp, const u_int len) { 114 const u_char *ep = cp + len; 115 116 ND_PRINT((ndo, ": OpenFlow")); 117 while (cp < ep) 118 cp = of_header_body_print(ndo, cp, ep); 119 } 120