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 /* \summary: version-independent OpenFlow printer */
34
35 #ifdef HAVE_CONFIG_H
36 #include <config.h>
37 #endif
38
39 #include "netdissect-stdinc.h"
40
41 #define ND_LONGJMP_FROM_TCHECK
42 #include "netdissect.h"
43 #include "extract.h"
44 #include "openflow.h"
45 #include "oui.h"
46
47
48 static const struct tok ofver_str[] = {
49 { OF_VER_1_0, "1.0" },
50 { OF_VER_1_1, "1.1" },
51 { OF_VER_1_2, "1.2" },
52 { OF_VER_1_3, "1.3" },
53 { OF_VER_1_4, "1.4" },
54 { OF_VER_1_5, "1.5" },
55 { 0, NULL }
56 };
57
58 const struct tok onf_exp_str[] = {
59 { ONF_EXP_ONF, "ONF Extensions" },
60 { ONF_EXP_BUTE, "Budapest University of Technology and Economics" },
61 { ONF_EXP_NOVIFLOW, "NoviFlow" },
62 { ONF_EXP_L3, "L3+ Extensions, Vendor Neutral" },
63 { ONF_EXP_L4L7, "L4-L7 Extensions" },
64 { ONF_EXP_WMOB, "Wireless and Mobility Extensions" },
65 { ONF_EXP_FABS, "Forwarding Abstractions Extensions" },
66 { ONF_EXP_OTRANS, "Optical Transport Extensions" },
67 { ONF_EXP_NBLNCTU, "Network Benchmarking Lab, NCTU" },
68 { ONF_EXP_MPCE, "Mobile Packet Core Extensions" },
69 { ONF_EXP_MPLSTPSPTN, "MPLS-TP OpenFlow Extensions for SPTN" },
70 { 0, NULL }
71 };
72
73 const char *
of_vendor_name(const uint32_t vendor)74 of_vendor_name(const uint32_t vendor)
75 {
76 const struct tok *table = (vendor & 0xff000000) == 0 ? oui_values : onf_exp_str;
77 return tok2str(table, "unknown", vendor);
78 }
79
80 void
of_bitmap_print(netdissect_options * ndo,const struct tok * t,const uint32_t v,const uint32_t u)81 of_bitmap_print(netdissect_options *ndo,
82 const struct tok *t, const uint32_t v, const uint32_t u)
83 {
84 /* Assigned bits? */
85 if (v & ~u)
86 ND_PRINT(" (%s)", bittok2str(t, "", v));
87 /* Unassigned bits? */
88 if (v & u)
89 ND_PRINT(" (bogus)");
90 }
91
92 void
of_data_print(netdissect_options * ndo,const u_char * cp,const u_int len)93 of_data_print(netdissect_options *ndo,
94 const u_char *cp, const u_int len)
95 {
96 if (len == 0)
97 return;
98 /* data */
99 ND_PRINT("\n\t data (%u octets)", len);
100 if (ndo->ndo_vflag >= 2)
101 hex_and_ascii_print(ndo, "\n\t ", cp, len);
102 else
103 ND_TCHECK_LEN(cp, len);
104 }
105
106 static void
of_message_print(netdissect_options * ndo,const u_char * cp,uint16_t len,const struct of_msgtypeinfo * mti)107 of_message_print(netdissect_options *ndo,
108 const u_char *cp, uint16_t len,
109 const struct of_msgtypeinfo *mti)
110 {
111 /*
112 * Here "cp" and "len" stand for the message part beyond the common
113 * OpenFlow 1.0 header, if any.
114 *
115 * Most message types are longer than just the header, and the length
116 * constraints may be complex. When possible, validate the constraint
117 * completely here (REQ_FIXLEN), otherwise check that the message is
118 * long enough to begin the decoding (REQ_MINLEN) and have the
119 * type-specific function do any remaining validation.
120 */
121
122 if (!mti)
123 goto tcheck_remainder;
124
125 if ((mti->req_what == REQ_FIXLEN && len != mti->req_value) ||
126 (mti->req_what == REQ_MINLEN && len < mti->req_value))
127 goto invalid;
128
129 if (!ndo->ndo_vflag || !mti->decoder)
130 goto tcheck_remainder;
131
132 mti->decoder(ndo, cp, len);
133 return;
134
135 invalid:
136 nd_print_invalid(ndo);
137 tcheck_remainder:
138 ND_TCHECK_LEN(cp, len);
139 }
140
141 /* Print a TCP segment worth of OpenFlow messages presuming the segment begins
142 * on a message boundary. */
143 void
openflow_print(netdissect_options * ndo,const u_char * cp,u_int len)144 openflow_print(netdissect_options *ndo, const u_char *cp, u_int len)
145 {
146 ndo->ndo_protocol = "openflow";
147 ND_PRINT(": OpenFlow");
148 while (len) {
149 /* Print a single OpenFlow message. */
150 uint8_t version, type;
151 uint16_t length;
152 const struct of_msgtypeinfo *mti;
153
154 /* version */
155 version = GET_U_1(cp);
156 OF_FWD(1);
157 ND_PRINT("\n\tversion %s",
158 tok2str(ofver_str, "unknown (0x%02x)", version));
159 /* type */
160 if (len < 1)
161 goto partial_header;
162 type = GET_U_1(cp);
163 OF_FWD(1);
164 mti =
165 version == OF_VER_1_0 ? of10_identify_msgtype(type) :
166 version == OF_VER_1_3 ? of13_identify_msgtype(type) :
167 NULL;
168 if (mti && mti->name)
169 ND_PRINT(", type %s", mti->name);
170 else
171 ND_PRINT(", type unknown (0x%02x)", type);
172 /* length */
173 if (len < 2)
174 goto partial_header;
175 length = GET_BE_U_2(cp);
176 OF_FWD(2);
177 ND_PRINT(", length %u%s", length,
178 length < OF_HEADER_FIXLEN ? " (too short!)" : "");
179 /* xid */
180 if (len < 4)
181 goto partial_header;
182 ND_PRINT(", xid 0x%08x", GET_BE_U_4(cp));
183 OF_FWD(4);
184
185 /*
186 * When a TCP packet can contain several protocol messages,
187 * and at the same time a protocol message can span several
188 * TCP packets, decoding an incomplete message at the end of
189 * a TCP packet requires attention to detail in this loop.
190 *
191 * Message length includes the header length and a message
192 * always includes the basic header. A message length underrun
193 * fails decoding of the rest of the current packet. At the
194 * same time, try decoding as much of the current message as
195 * possible even when it does not end within the current TCP
196 * segment.
197 *
198 * Specifically, to try to process the message body in this
199 * iteration do NOT require the header "length" to be small
200 * enough for the full declared OpenFlow message to fit into
201 * the remainder of the declared TCP segment, same as the full
202 * declared TCP segment is not required to fit into the
203 * captured packet buffer.
204 *
205 * But DO require the same at the end of this iteration to
206 * decrement "len" and to proceed to the next iteration.
207 * (Ideally the declared TCP payload end will be at or after
208 * the captured packet buffer end, but stay safe even when
209 * that's somehow not the case.)
210 */
211 if (length < OF_HEADER_FIXLEN)
212 goto invalid;
213
214 of_message_print(ndo, cp, length - OF_HEADER_FIXLEN, mti);
215 if (length - OF_HEADER_FIXLEN > len)
216 break;
217 OF_FWD(length - OF_HEADER_FIXLEN);
218 } /* while (len) */
219 return;
220
221 partial_header:
222 ND_PRINT(" (end of TCP payload)");
223 ND_TCHECK_LEN(cp, len);
224 return;
225 invalid: /* fail the current packet */
226 nd_print_invalid(ndo);
227 ND_TCHECK_LEN(cp, len);
228 }
229