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