Bug Summary

File:src/usr.sbin/tcpdump/print-lldp.c
Warning:line 283, column 4
Value stored to 'v' is never read

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.4 -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name print-lldp.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/usr.sbin/tcpdump/obj -resource-dir /usr/local/llvm16/lib/clang/16 -I /usr/src/usr.sbin/tcpdump/../../sbin/pfctl -I /usr/src/usr.sbin/tcpdump/../hostapd -I /usr/src/usr.sbin/tcpdump/../../lib/libpcap -D CSLIP -D PPP -D HAVE_FDDI -D ETHER_SERVICE -D HAVE_ETHER_NTOHOST -D INET6 -I /usr/src/usr.sbin/tcpdump/../../sbin/pfctl -D FAKE_PF_KERNEL -internal-isystem /usr/local/llvm16/lib/clang/16/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/usr.sbin/tcpdump/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fcf-protection=branch -fno-jump-tables -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/scan/2024-01-11-140451-98009-1 -x c /usr/src/usr.sbin/tcpdump/print-lldp.c
1/* $OpenBSD: print-lldp.c,v 1.9 2016/11/28 17:47:15 jca Exp $ */
2
3/*
4 * Copyright (c) 2006 Reyk Floeter <reyk@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <sys/time.h>
20#include <sys/socket.h>
21
22#include <net/if.h>
23
24#include <netinet/in.h>
25#include <netinet/if_ether.h>
26#include <arpa/inet.h>
27
28#include <ctype.h>
29#include <stdio.h>
30#include <string.h>
31
32#include "addrtoname.h"
33#include "extract.h"
34#include "interface.h"
35#include "afnum.h"
36
37enum {
38 LLDP_TLV_END = 0,
39 LLDP_TLV_CHASSIS_ID = 1,
40 LLDP_TLV_PORT_ID = 2,
41 LLDP_TLV_TTL = 3,
42 LLDP_TLV_PORT_DESCR = 4,
43 LLDP_TLV_SYSTEM_NAME = 5,
44 LLDP_TLV_SYSTEM_DESCR = 6,
45 LLDP_TLV_SYSTEM_CAP = 7,
46 LLDP_TLV_MANAGEMENT_ADDR = 8,
47 LLDP_TLV_ORG = 127
48};
49
50enum {
51 LLDP_CHASSISID_SUBTYPE_CHASSIS = 1,
52 LLDP_CHASSISID_SUBTYPE_IFALIAS = 2,
53 LLDP_CHASSISID_SUBTYPE_PORT = 3,
54 LLDP_CHASSISID_SUBTYPE_LLADDR = 4,
55 LLDP_CHASSISID_SUBTYPE_ADDR = 5,
56 LLDP_CHASSISID_SUBTYPE_IFNAME = 6,
57 LLDP_CHASSISID_SUBTYPE_LOCAL = 7
58};
59
60enum {
61 LLDP_PORTID_SUBTYPE_IFALIAS = 1,
62 LLDP_PORTID_SUBTYPE_PORT = 2,
63 LLDP_PORTID_SUBTYPE_LLADDR = 3,
64 LLDP_PORTID_SUBTYPE_ADDR = 4,
65 LLDP_PORTID_SUBTYPE_IFNAME = 5,
66 LLDP_PORTID_SUBTYPE_AGENTCID = 6,
67 LLDP_PORTID_SUBTYPE_LOCAL = 7
68};
69
70#define LLDP_CAP_OTHER0x01 0x01
71#define LLDP_CAP_REPEATER0x02 0x02
72#define LLDP_CAP_BRIDGE0x04 0x04
73#define LLDP_CAP_WLAN0x08 0x08
74#define LLDP_CAP_ROUTER0x10 0x10
75#define LLDP_CAP_TELEPHONE0x20 0x20
76#define LLDP_CAP_DOCSIS0x40 0x40
77#define LLDP_CAP_STATION0x80 0x80
78#define LLDP_CAP_BITS"\20\01OTHER\02REPEATER\03BRIDGE\04WLAN\05ROUTER\06TELEPHONE"
"\07DOCSIS\10STATION" \
79 "\20\01OTHER\02REPEATER\03BRIDGE\04WLAN\05ROUTER\06TELEPHONE" \
80 "\07DOCSIS\10STATION"
81
82enum {
83 LLDP_MGMT_IFACE_UNKNOWN = 1,
84 LLDP_MGMT_IFACE_IFINDEX = 2,
85 LLDP_MGMT_IFACE_SYSPORT = 3
86};
87
88static const char *afnumber[] = AFNUM_NAME_STR{ "Reserved", "IPv4", "IPv6", "NSAP", "HDLC", "BBN 1822", "802"
, "E.163", "E.164", "F.69", "X.121", "IPX", "Appletalk", "Decnet IV"
, "Banyan Vines", "E.164 with NSAP subaddress", "DNS", "AS Number"
, "XTP over IPv4", "XTP over IPv6", "XTP native mode", "Fibre Channel WWPN"
, "Fibre Channel WWNN", "GWID" };
89
90void lldp_print_str(u_int8_t *, int);
91const char *lldp_print_addr(int, const void *);
92void lldp_print_id(int, u_int8_t *, int);
93
94void
95lldp_print_str(u_int8_t *str, int len)
96{
97 int i;
98 printf("\"");
99 for (i = 0; i < len; i++)
100 printf("%c", isprint(str[i]) ? str[i] : '.');
101 printf("\"");
102}
103
104const char *
105lldp_print_addr(int af, const void *addr)
106{
107 static char buf[48];
108 if (inet_ntop(af, addr, buf, sizeof(buf)) == NULL((void *)0))
109 return ("?");
110 return (buf);
111}
112
113void
114lldp_print_id(int type, u_int8_t *ptr, int len)
115{
116 u_int8_t id;
117 u_int8_t *data;
118
119 id = *(u_int8_t *)ptr;
120 len -= sizeof(u_int8_t);
121 data = ptr + sizeof(u_int8_t);
122 if (len <= 0)
123 return;
124
125 if (type == LLDP_TLV_CHASSIS_ID) {
126 switch (id) {
127 case LLDP_CHASSISID_SUBTYPE_CHASSIS:
128 printf("chassis ");
129 lldp_print_str(data, len);
130 break;
131 case LLDP_CHASSISID_SUBTYPE_IFALIAS:
132 printf("ifalias");
133 break;
134 case LLDP_CHASSISID_SUBTYPE_PORT:
135 printf("port");
136 break;
137 case LLDP_CHASSISID_SUBTYPE_LLADDR:
138 printf("lladdr %s", etheraddr_string(data));
139 break;
140 case LLDP_CHASSISID_SUBTYPE_ADDR:
141 printf("addr");
142 break;
143 case LLDP_CHASSISID_SUBTYPE_IFNAME:
144 printf("ifname ");
145 lldp_print_str(data, len);
146 break;
147 case LLDP_CHASSISID_SUBTYPE_LOCAL:
148 printf("local ");
149 lldp_print_str(data, len);
150 break;
151 default:
152 printf("unknown 0x%02x", id);
153 break;
154 }
155
156 } else if (type == LLDP_TLV_PORT_ID) {
157 switch (id) {
158 case LLDP_PORTID_SUBTYPE_IFALIAS:
159 printf("ifalias");
160 break;
161 case LLDP_PORTID_SUBTYPE_PORT:
162 printf("port");
163 break;
164 case LLDP_PORTID_SUBTYPE_LLADDR:
165 printf("lladdr %s", etheraddr_string(data));
166 break;
167 case LLDP_PORTID_SUBTYPE_ADDR:
168 printf("addr");
169 break;
170 case LLDP_PORTID_SUBTYPE_IFNAME:
171 printf("ifname ");
172 lldp_print_str(data, len);
173 break;
174 case LLDP_PORTID_SUBTYPE_AGENTCID:
175 printf("agentcid");
176 break;
177 case LLDP_PORTID_SUBTYPE_LOCAL:
178 printf("local ");
179 lldp_print_str(data, len);
180 break;
181 default:
182 printf("unknown 0x%02x", id);
183 break;
184 }
185 }
186}
187
188void
189lldp_print(const u_char *p, u_int len)
190{
191 u_int16_t tlv;
192 u_int8_t *ptr = (u_int8_t *)p, v = 0;
193 int n, type, vlen, alen;
194
195 printf("LLDP");
196
197#define _ptrinc(_v)ptr += (_v); vlen -= (_v); ptr += (_v); vlen -= (_v);
198
199 for (n = 0; n < len;) {
200 TCHECK2(*ptr, sizeof(tlv))if (!(snapend - (sizeof(tlv)) <= snapend && (const
u_char *)&(*ptr) <= snapend - (sizeof(tlv)))) goto trunc;
201
202 tlv = EXTRACT_16BITS(ptr)((u_int16_t)*((const u_int8_t *)(ptr) + 0) << 8 | (u_int16_t
)*((const u_int8_t *)(ptr) + 1));
203 type = (tlv & 0xfe00) >> 9;
204 vlen = tlv & 0x1ff;
205 n += vlen;
206
207 ptr += sizeof(tlv);
208 TCHECK2(*ptr, vlen)if (!(snapend - (vlen) <= snapend && (const u_char
*)&(*ptr) <= snapend - (vlen))) goto trunc;
209
210 switch (type) {
211 case LLDP_TLV_END:
212 goto done;
213 break;
214
215 case LLDP_TLV_CHASSIS_ID:
216 printf(", ChassisId: ");
217 lldp_print_id(type, ptr, vlen);
218 break;
219
220 case LLDP_TLV_PORT_ID:
221 printf(", PortId: ");
222 lldp_print_id(type, ptr, vlen);
223 break;
224
225 case LLDP_TLV_TTL:
226 printf(", TTL: ");
227 TCHECK2(*ptr, 2)if (!(snapend - (2) <= snapend && (const u_char *)
&(*ptr) <= snapend - (2))) goto trunc;
228 printf("%ds", EXTRACT_16BITS(ptr)((u_int16_t)*((const u_int8_t *)(ptr) + 0) << 8 | (u_int16_t
)*((const u_int8_t *)(ptr) + 1)));
229 break;
230
231 case LLDP_TLV_PORT_DESCR:
232 printf(", PortDescr: ");
233 lldp_print_str(ptr, vlen);
234 break;
235
236 case LLDP_TLV_SYSTEM_NAME:
237 printf(", SysName: ");
238 lldp_print_str(ptr, vlen);
239 break;
240
241 case LLDP_TLV_SYSTEM_DESCR:
242 printf(", SysDescr: ");
243 lldp_print_str(ptr, vlen);
244 break;
245
246 case LLDP_TLV_SYSTEM_CAP:
247 printf(", CAP:");
248 TCHECK2(*ptr, 4)if (!(snapend - (4) <= snapend && (const u_char *)
&(*ptr) <= snapend - (4))) goto trunc;
249 printb(" available", EXTRACT_16BITS(ptr)((u_int16_t)*((const u_int8_t *)(ptr) + 0) << 8 | (u_int16_t
)*((const u_int8_t *)(ptr) + 1)),
250 LLDP_CAP_BITS"\20\01OTHER\02REPEATER\03BRIDGE\04WLAN\05ROUTER\06TELEPHONE"
"\07DOCSIS\10STATION");
251 _ptrinc(sizeof(u_int16_t))ptr += (sizeof(u_int16_t)); vlen -= (sizeof(u_int16_t));;
252 printb(" enabled", EXTRACT_16BITS(ptr)((u_int16_t)*((const u_int8_t *)(ptr) + 0) << 8 | (u_int16_t
)*((const u_int8_t *)(ptr) + 1)),
253 LLDP_CAP_BITS"\20\01OTHER\02REPEATER\03BRIDGE\04WLAN\05ROUTER\06TELEPHONE"
"\07DOCSIS\10STATION");
254 break;
255
256 case LLDP_TLV_MANAGEMENT_ADDR:
257 printf(", MgmtAddr:");
258 TCHECK2(*ptr, 2)if (!(snapend - (2) <= snapend && (const u_char *)
&(*ptr) <= snapend - (2))) goto trunc;
259 alen = *ptr - sizeof(u_int8_t);
260 _ptrinc(sizeof(u_int8_t))ptr += (sizeof(u_int8_t)); vlen -= (sizeof(u_int8_t));;
261 v = *ptr;
262 _ptrinc(sizeof(u_int8_t))ptr += (sizeof(u_int8_t)); vlen -= (sizeof(u_int8_t));;
263 if (v < AFNUM_MAX24)
264 printf(" %s", afnumber[v]);
265 else
266 printf(" type %d", v);
267 TCHECK2(*ptr, alen)if (!(snapend - (alen) <= snapend && (const u_char
*)&(*ptr) <= snapend - (alen))) goto trunc;
268 switch (v) {
269 case AFNUM_INET1:
270 if (alen != sizeof(struct in_addr))
271 goto trunc;
272 printf(" %s",
273 lldp_print_addr(AF_INET2, ptr));
274 break;
275 case AFNUM_INET62:
276 if (alen != sizeof(struct in6_addr))
277 goto trunc;
278 printf(" %s",
279 lldp_print_addr(AF_INET624, ptr));
280 break;
281 }
282 _ptrinc(alen)ptr += (alen); vlen -= (alen);;
283 v = *(u_int8_t *)ptr;
Value stored to 'v' is never read
284 break;
285
286 case LLDP_TLV_ORG:
287 printf(", Org");
288 break;
289
290 default:
291 printf(", type %d length %d", type, vlen);
292 break;
293 }
294 ptr += vlen;
295 }
296
297 done:
298 return;
299
300 trunc:
301 printf(" [|LLDP]");
302}
303