Bug Summary

File:src/lib/libc/net/inet_pton.c
Warning:line 182, column 4
Value stored to 'count_xdigit' is never read

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name inet_pton.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -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 -fno-rounding-math -mconstructor-aliases -munwind-tables -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/lib/libc/obj -resource-dir /usr/local/lib/clang/13.0.0 -include namespace.h -I /usr/src/lib/libc/include -I /usr/src/lib/libc/hidden -D __LIBC__ -D APIWARN -D YP -I /usr/src/lib/libc/yp -I /usr/src/lib/libc -I /usr/src/lib/libc/gdtoa -I /usr/src/lib/libc/arch/amd64/gdtoa -D INFNAN_CHECK -D MULTIPLE_THREADS -D NO_FENV_H -D USE_LOCALE -I /usr/src/lib/libc -I /usr/src/lib/libc/citrus -D RESOLVSORT -D FLOATING_POINT -D PRINTF_WIDE_CHAR -D SCANF_WIDE_CHAR -D FUTEX -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/lib/libc/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -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/vmm/scan-build/2022-01-12-194120-40624-1 -x c /usr/src/lib/libc/net/inet_pton.c
1/* $OpenBSD: inet_pton.c,v 1.10 2015/09/13 21:36:08 guenther Exp $ */
2
3/* Copyright (c) 1996 by Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
10 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
11 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
12 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
13 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
14 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
15 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
16 * SOFTWARE.
17 */
18
19#include <sys/types.h>
20#include <sys/socket.h>
21#include <netinet/in.h>
22#include <arpa/inet.h>
23#include <arpa/nameser.h>
24#include <string.h>
25#include <errno(*__errno()).h>
26
27/*
28 * WARNING: Don't even consider trying to compile this on a system where
29 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
30 */
31
32static int inet_pton4(const char *src, u_char *dst);
33static int inet_pton6(const char *src, u_char *dst);
34
35/* int
36 * inet_pton(af, src, dst)
37 * convert from presentation format (which usually means ASCII printable)
38 * to network format (which is usually some kind of binary format).
39 * return:
40 * 1 if the address was valid for the specified address family
41 * 0 if the address wasn't valid (`dst' is untouched in this case)
42 * -1 if some other error occurred (`dst' is untouched in this case, too)
43 * author:
44 * Paul Vixie, 1996.
45 */
46int
47inet_pton(int af, const char *src, void *dst)
48{
49 switch (af) {
50 case AF_INET2:
51 return (inet_pton4(src, dst));
52 case AF_INET624:
53 return (inet_pton6(src, dst));
54 default:
55 errno(*__errno()) = EAFNOSUPPORT47;
56 return (-1);
57 }
58 /* NOTREACHED */
59}
60DEF_WEAK(inet_pton)__asm__(".weak " "inet_pton" " ; " "inet_pton" " = " "_libc_inet_pton"
);
61
62/* int
63 * inet_pton4(src, dst)
64 * like inet_aton() but without all the hexadecimal and shorthand.
65 * return:
66 * 1 if `src' is a valid dotted quad, else 0.
67 * notice:
68 * does not touch `dst' unless it's returning 1.
69 * author:
70 * Paul Vixie, 1996.
71 */
72static int
73inet_pton4(const char *src, u_char *dst)
74{
75 static const char digits[] = "0123456789";
76 int saw_digit, octets, ch;
77 u_char tmp[INADDRSZ4], *tp;
78
79 saw_digit = 0;
80 octets = 0;
81 *(tp = tmp) = 0;
82 while ((ch = *src++) != '\0') {
83 const char *pch;
84
85 if ((pch = strchr(digits, ch)) != NULL((void *)0)) {
86 u_int new = *tp * 10 + (pch - digits);
87
88 if (new > 255)
89 return (0);
90 if (! saw_digit) {
91 if (++octets > 4)
92 return (0);
93 saw_digit = 1;
94 }
95 *tp = new;
96 } else if (ch == '.' && saw_digit) {
97 if (octets == 4)
98 return (0);
99 *++tp = 0;
100 saw_digit = 0;
101 } else
102 return (0);
103 }
104 if (octets < 4)
105 return (0);
106
107 memcpy(dst, tmp, INADDRSZ4);
108 return (1);
109}
110
111/* int
112 * inet_pton6(src, dst)
113 * convert presentation level address to network order binary form.
114 * return:
115 * 1 if `src' is a valid [RFC1884 2.2] address, else 0.
116 * notice:
117 * does not touch `dst' unless it's returning 1.
118 * credit:
119 * inspired by Mark Andrews.
120 * author:
121 * Paul Vixie, 1996.
122 */
123static int
124inet_pton6(const char *src, u_char *dst)
125{
126 static const char xdigits_l[] = "0123456789abcdef",
127 xdigits_u[] = "0123456789ABCDEF";
128 u_char tmp[IN6ADDRSZ16], *tp, *endp, *colonp;
129 const char *xdigits, *curtok;
130 int ch, saw_xdigit, count_xdigit;
131 u_int val;
132
133 memset((tp = tmp), '\0', IN6ADDRSZ16);
134 endp = tp + IN6ADDRSZ16;
135 colonp = NULL((void *)0);
136 /* Leading :: requires some special handling. */
137 if (*src == ':')
138 if (*++src != ':')
139 return (0);
140 curtok = src;
141 saw_xdigit = count_xdigit = 0;
142 val = 0;
143 while ((ch = *src++) != '\0') {
144 const char *pch;
145
146 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL((void *)0))
147 pch = strchr((xdigits = xdigits_u), ch);
148 if (pch != NULL((void *)0)) {
149 if (count_xdigit >= 4)
150 return (0);
151 val <<= 4;
152 val |= (pch - xdigits);
153 if (val > 0xffff)
154 return (0);
155 saw_xdigit = 1;
156 count_xdigit++;
157 continue;
158 }
159 if (ch == ':') {
160 curtok = src;
161 if (!saw_xdigit) {
162 if (colonp)
163 return (0);
164 colonp = tp;
165 continue;
166 } else if (*src == '\0') {
167 return (0);
168 }
169 if (tp + INT16SZ2 > endp)
170 return (0);
171 *tp++ = (u_char) (val >> 8) & 0xff;
172 *tp++ = (u_char) val & 0xff;
173 saw_xdigit = 0;
174 count_xdigit = 0;
175 val = 0;
176 continue;
177 }
178 if (ch == '.' && ((tp + INADDRSZ4) <= endp) &&
179 inet_pton4(curtok, tp) > 0) {
180 tp += INADDRSZ4;
181 saw_xdigit = 0;
182 count_xdigit = 0;
Value stored to 'count_xdigit' is never read
183 break; /* '\0' was seen by inet_pton4(). */
184 }
185 return (0);
186 }
187 if (saw_xdigit) {
188 if (tp + INT16SZ2 > endp)
189 return (0);
190 *tp++ = (u_char) (val >> 8) & 0xff;
191 *tp++ = (u_char) val & 0xff;
192 }
193 if (colonp != NULL((void *)0)) {
194 /*
195 * Since some memmove()'s erroneously fail to handle
196 * overlapping regions, we'll do the shift by hand.
197 */
198 const int n = tp - colonp;
199 int i;
200
201 if (tp == endp)
202 return (0);
203 for (i = 1; i <= n; i++) {
204 endp[- i] = colonp[n - i];
205 colonp[n - i] = 0;
206 }
207 tp = endp;
208 }
209 if (tp != endp)
210 return (0);
211 memcpy(dst, tmp, IN6ADDRSZ16);
212 return (1);
213}