JP Abgrall | 53f17a9 | 2014-02-12 14:02:41 -0800 | [diff] [blame] | 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 | } |