Bug Summary

File:netinet6/dest6.c
Warning:line 70, column 7
Value stored to 'optlen' 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 dest6.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 static -mframe-pointer=all -relaxed-aliasing -ffp-contract=on -fno-rounding-math -mconstructor-aliases -ffreestanding -mcmodel=kernel -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -target-feature -sse2 -target-feature -sse -target-feature -3dnow -target-feature -mmx -target-feature +save-args -target-feature +retpoline-external-thunk -disable-red-zone -no-implicit-float -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -nostdsysteminc -nobuiltininc -resource-dir /usr/local/llvm16/lib/clang/16 -I /usr/src/sys -I /usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -I /usr/src/sys/arch -I /usr/src/sys/dev/pci/drm/include -I /usr/src/sys/dev/pci/drm/include/uapi -I /usr/src/sys/dev/pci/drm/amd/include/asic_reg -I /usr/src/sys/dev/pci/drm/amd/include -I /usr/src/sys/dev/pci/drm/amd/amdgpu -I /usr/src/sys/dev/pci/drm/amd/display -I /usr/src/sys/dev/pci/drm/amd/display/include -I /usr/src/sys/dev/pci/drm/amd/display/dc -I /usr/src/sys/dev/pci/drm/amd/display/amdgpu_dm -I /usr/src/sys/dev/pci/drm/amd/pm/inc -I /usr/src/sys/dev/pci/drm/amd/pm/legacy-dpm -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/inc -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu11 -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu12 -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu13 -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/inc -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/hwmgr -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/smumgr -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/inc -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/inc/pmfw_if -I /usr/src/sys/dev/pci/drm/amd/display/dc/inc -I /usr/src/sys/dev/pci/drm/amd/display/dc/inc/hw -I /usr/src/sys/dev/pci/drm/amd/display/dc/clk_mgr -I /usr/src/sys/dev/pci/drm/amd/display/modules/inc -I /usr/src/sys/dev/pci/drm/amd/display/modules/hdcp -I /usr/src/sys/dev/pci/drm/amd/display/dmub/inc -I /usr/src/sys/dev/pci/drm/i915 -D DDB -D DIAGNOSTIC -D KTRACE -D ACCOUNTING -D KMEMSTATS -D PTRACE -D POOL_DEBUG -D CRYPTO -D SYSVMSG -D SYSVSEM -D SYSVSHM -D UVM_SWAP_ENCRYPT -D FFS -D FFS2 -D FFS_SOFTUPDATES -D UFS_DIRHASH -D QUOTA -D EXT2FS -D MFS -D NFSCLIENT -D NFSSERVER -D CD9660 -D UDF -D MSDOSFS -D FIFO -D FUSE -D SOCKET_SPLICE -D TCP_ECN -D TCP_SIGNATURE -D INET6 -D IPSEC -D PPP_BSDCOMP -D PPP_DEFLATE -D PIPEX -D MROUTING -D MPLS -D BOOT_CONFIG -D USER_PCICONF -D APERTURE -D MTRR -D NTFS -D SUSPEND -D HIBERNATE -D PCIVERBOSE -D USBVERBOSE -D WSDISPLAY_COMPAT_USL -D WSDISPLAY_COMPAT_RAWKBD -D WSDISPLAY_DEFAULTSCREENS=6 -D X86EMU -D ONEWIREVERBOSE -D MULTIPROCESSOR -D MAXUSERS=80 -D _KERNEL -O2 -Wno-pointer-sign -Wno-address-of-packed-member -Wno-constant-conversion -Wno-unused-but-set-variable -Wno-gnu-folding-constant -fdebug-compilation-dir=/usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fcf-protection=branch -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 -o /home/ben/Projects/scan/2024-01-11-110808-61670-1 -x c /usr/src/sys/netinet6/dest6.c
1/* $OpenBSD: dest6.c,v 1.19 2022/06/29 22:45:24 bluhm Exp $ */
2/* $KAME: dest6.c,v 1.25 2001/02/22 01:39:16 itojun Exp $ */
3
4/*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/param.h>
34#include <sys/systm.h>
35#include <sys/mbuf.h>
36#include <sys/socket.h>
37#include <sys/errno.h>
38#include <sys/time.h>
39#include <sys/kernel.h>
40
41#include <netinet/in.h>
42#include <netinet/ip6.h>
43#include <netinet6/ip6_var.h>
44#include <netinet/icmp6.h>
45
46/*
47 * Destination options header processing.
48 */
49int
50dest6_input(struct mbuf **mp, int *offp, int proto, int af)
51{
52 int off = *offp, dstoptlen, optlen;
53 struct ip6_dest *dstopts;
54 u_int8_t *opt;
55
56 /* validation of the length of the header */
57 IP6_EXTHDR_GET(dstopts, struct ip6_dest *, *mp, off, sizeof(*dstopts))do { struct mbuf *t; int tmp; if ((*mp)->m_hdr.mh_len >=
(off) + (sizeof(*dstopts))) (dstopts) = (struct ip6_dest *)(
((caddr_t)(((*mp))->m_hdr.mh_data)) + (off)); else { t = m_pulldown
((*mp), (off), (sizeof(*dstopts)), &tmp); if (t) { if (t->
m_hdr.mh_len < tmp + (sizeof(*dstopts))) panic("m_pulldown malfunction"
); (dstopts) = (struct ip6_dest *)(((caddr_t)((t)->m_hdr.mh_data
)) + tmp); } else { (dstopts) = (struct ip6_dest *)((void *)0
); (*mp) = ((void *)0); } } } while ( 0)
;
58 if (dstopts == NULL((void *)0))
59 return IPPROTO_DONE257;
60 dstoptlen = (dstopts->ip6d_len + 1) << 3;
61
62 IP6_EXTHDR_GET(dstopts, struct ip6_dest *, *mp, off, dstoptlen)do { struct mbuf *t; int tmp; if ((*mp)->m_hdr.mh_len >=
(off) + (dstoptlen)) (dstopts) = (struct ip6_dest *)(((caddr_t
)(((*mp))->m_hdr.mh_data)) + (off)); else { t = m_pulldown
((*mp), (off), (dstoptlen), &tmp); if (t) { if (t->m_hdr
.mh_len < tmp + (dstoptlen)) panic("m_pulldown malfunction"
); (dstopts) = (struct ip6_dest *)(((caddr_t)((t)->m_hdr.mh_data
)) + tmp); } else { (dstopts) = (struct ip6_dest *)((void *)0
); (*mp) = ((void *)0); } } } while ( 0)
;
63 if (dstopts == NULL((void *)0))
64 return IPPROTO_DONE257;
65 off += dstoptlen;
66 dstoptlen -= sizeof(struct ip6_dest);
67 opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
68
69 /* search header for all options. */
70 for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
Value stored to 'optlen' is never read
71 if (*opt != IP6OPT_PAD10x00 &&
72 (dstoptlen < IP6OPT_MINLEN2 || *(opt + 1) + 2 > dstoptlen)) {
73 ip6stat_inc(ip6s_toosmall);
74 goto bad;
75 }
76
77 switch (*opt) {
78 case IP6OPT_PAD10x00:
79 optlen = 1;
80 break;
81 case IP6OPT_PADN0x01:
82 optlen = *(opt + 1) + 2;
83 break;
84 default: /* unknown option */
85 optlen = ip6_unknown_opt(mp, opt,
86 opt - mtod(*mp, u_int8_t *)((u_int8_t *)((*mp)->m_hdr.mh_data)));
87 if (optlen == -1)
88 return (IPPROTO_DONE257);
89 optlen += 2;
90 break;
91 }
92 }
93
94 *offp = off;
95 return (dstopts->ip6d_nxt);
96
97 bad:
98 m_freemp(mp);
99 return (IPPROTO_DONE257);
100}