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 #ifdef HAVE_CONFIG_H 34 #include "config.h" 35 #endif 36 37 #include <tcpdump-stdinc.h> 38 39 #include "interface.h" 40 #include "extract.h" 41 #include "openflow.h" 42 43 #define OF_VER_1_0 0x01 44 45 static void 46 of_header_print(const uint8_t version, const uint8_t type, 47 const uint16_t length, const uint32_t xid) { 48 printf("\n\tversion unknown (0x%02x), type 0x%02x, length %u, xid 0x%08x", 49 version, type, length, xid); 50 } 51 52 /* Print a single OpenFlow message. */ 53 static const u_char * 54 of_header_body_print(const u_char *cp, const u_char *ep) { 55 uint8_t version, type; 56 uint16_t length; 57 uint32_t xid; 58 59 if (ep < cp + OF_HEADER_LEN) 60 goto corrupt; 61 /* version */ 62 TCHECK2(*cp, 1); 63 version = *cp; 64 cp += 1; 65 /* type */ 66 TCHECK2(*cp, 1); 67 type = *cp; 68 cp += 1; 69 /* length */ 70 TCHECK2(*cp, 2); 71 length = EXTRACT_16BITS(cp); 72 cp += 2; 73 /* xid */ 74 TCHECK2(*cp, 4); 75 xid = EXTRACT_32BITS(cp); 76 cp += 4; 77 /* Message length includes the header length and a message always includes 78 * the basic header. A message length underrun fails decoding of the rest of 79 * the current packet. At the same time, try decoding as much of the current 80 * message as possible even when it does not end within the current TCP 81 * segment. */ 82 if (length < OF_HEADER_LEN) { 83 of_header_print(version, type, length, xid); 84 goto corrupt; 85 } 86 /* Decode known protocol versions further without printing the header (the 87 * type decoding is version-specific. */ 88 switch (version) { 89 case OF_VER_1_0: 90 return of10_header_body_print(cp, ep, type, length, xid); 91 default: 92 of_header_print(version, type, length, xid); 93 TCHECK2(*cp, length - OF_HEADER_LEN); 94 return cp + length - OF_HEADER_LEN; /* done with current message */ 95 } 96 97 corrupt: /* fail current packet */ 98 printf(" (corrupt)"); 99 TCHECK2(*cp, ep - cp); 100 return ep; 101 trunc: 102 printf(" [|openflow]"); 103 return ep; 104 } 105 106 /* Print a TCP segment worth of OpenFlow messages presuming the segment begins 107 * on a message boundary. */ 108 void 109 openflow_print(const u_char *cp, const u_int len) { 110 const u_char *ep = cp + len; 111 112 printf(": OpenFlow"); 113 while (cp < ep) 114 cp = of_header_body_print(cp, ep); 115 } 116
