Bug Summary

File:src/usr.bin/w/w.c
Warning:line 156, column 2
Value stored to 'argc' 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 w.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/usr.bin/w/obj -resource-dir /usr/local/lib/clang/13.0.0 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/usr.bin/w/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/usr.bin/w/w.c
1/* $OpenBSD: w.c,v 1.66 2019/06/28 13:35:05 deraadt Exp $ */
2
3/*-
4 * Copyright (c) 1980, 1991, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32/*
33 * w - print system status (who and what)
34 *
35 * This program is similar to the systat command on Tenex/Tops 10/20
36 *
37 */
38#include <sys/param.h> /* MAXCOMLEN */
39#include <sys/time.h>
40#include <sys/stat.h>
41#include <sys/sysctl.h>
42#include <sys/signal.h>
43#include <sys/proc.h>
44#include <sys/ioctl.h>
45#include <sys/socket.h>
46#include <sys/tty.h>
47
48#include <netinet/in.h>
49#include <arpa/inet.h>
50
51#include <ctype.h>
52#include <err.h>
53#include <errno(*__errno()).h>
54#include <fcntl.h>
55#include <kvm.h>
56#include <netdb.h>
57#include <nlist.h>
58#include <paths.h>
59#include <stdio.h>
60#include <stdlib.h>
61#include <string.h>
62#include <unistd.h>
63#include <limits.h>
64#include <utmp.h>
65#include <vis.h>
66
67#include "extern.h"
68
69struct utmp utmp;
70struct winsize ws;
71kvm_t *kd;
72time_t now; /* the current time of day */
73int ttywidth; /* width of tty */
74int argwidth; /* width of tty */
75int header = 1; /* true if -h flag: don't print heading */
76int nflag = 1; /* true if -n flag: don't convert addrs */
77int sortidle; /* sort by idle time */
78char *sel_user; /* login of particular user selected */
79char domain[HOST_NAME_MAX255+1];
80
81#define NAME_WIDTH8 8
82#define HOST_WIDTH16 16
83
84/*
85 * One of these per active utmp entry.
86 */
87struct entry {
88 struct entry *next;
89 struct utmp utmp;
90 dev_t tdev; /* dev_t of terminal */
91 time_t idle; /* idle time of terminal in seconds */
92 struct kinfo_proc *kp; /* `most interesting' proc */
93} *ep, *ehead = NULL((void *)0), **nextp = &ehead;
94
95static void fmt_putc(int, int *);
96static void fmt_puts(const char *, int *);
97static void pr_args(struct kinfo_proc *);
98static void pr_header(time_t *, int);
99static struct stat
100 *ttystat(char *);
101static void usage(int);
102
103int
104main(int argc, char *argv[])
105{
106 extern char *__progname;
107 struct kinfo_proc *kp;
108 struct hostent *hp;
109 struct stat *stp;
110 FILE *ut;
111 struct in_addr addr;
112 int ch, i, nentries, nusers, wcmd;
113 char *memf, *nlistf, *p, *x;
114 char buf[HOST_NAME_MAX255+1], errbuf[_POSIX2_LINE_MAX2048];
115
116 /* Are we w(1) or uptime(1)? */
117 p = __progname;
118 if (*p == '-')
119 p++;
120 if (p[0] == 'w' && p[1] == '\0') {
121 wcmd = 1;
122 p = "hiflM:N:asuw";
123 } else if (!strcmp(p, "uptime")) {
124 wcmd = 0;
125 p = "";
126 } else
127 errx(1,
128 "this program should be invoked only as \"w\" or \"uptime\"");
129
130 memf = nlistf = NULL((void *)0);
131 while ((ch = getopt(argc, argv, p)) != -1)
132 switch (ch) {
133 case 'h':
134 header = 0;
135 break;
136 case 'i':
137 sortidle = 1;
138 break;
139 case 'M':
140 header = 0;
141 memf = optarg;
142 break;
143 case 'N':
144 nlistf = optarg;
145 break;
146 case 'a':
147 nflag = 0;
148 break;
149 case 'f': case 'l': case 's': case 'u': case 'w':
150 warnx("[-flsuw] no longer supported");
151 /* FALLTHROUGH */
152 case '?':
153 default:
154 usage(wcmd);
155 }
156 argc -= optind;
Value stored to 'argc' is never read
157 argv += optind;
158
159 if (nflag == 0) {
160 if (pledge("stdio tty rpath dns ps vminfo", NULL((void *)0)) == -1)
161 err(1, "pledge");
162 } else {
163 if (pledge("stdio tty rpath ps vminfo", NULL((void *)0)) == -1)
164 err(1, "pledge");
165 }
166
167 if (nlistf == NULL((void *)0) && memf == NULL((void *)0)) {
168 if ((kd = kvm_openfiles(nlistf, memf, NULL((void *)0), KVM_NO_FILES0x80000000,
169 errbuf)) == NULL((void *)0))
170 errx(1, "%s", errbuf);
171 } else {
172 if ((kd = kvm_openfiles(nlistf, memf, NULL((void *)0), O_RDONLY0x0000, errbuf)) == NULL((void *)0))
173 errx(1, "%s", errbuf);
174 }
175
176 (void)time(&now);
177 if ((ut = fopen(_PATH_UTMP"/var/run/utmp", "r")) == NULL((void *)0))
178 err(1, "%s", _PATH_UTMP"/var/run/utmp");
179
180 if (*argv)
181 sel_user = *argv;
182
183 for (nusers = 0; fread(&utmp, sizeof(utmp), 1, ut);) {
184 if (utmp.ut_name[0] == '\0')
185 continue;
186 ++nusers;
187 if (wcmd == 0 || (sel_user &&
188 strncmp(utmp.ut_name, sel_user, UT_NAMESIZE32) != 0))
189 continue;
190 if ((ep = calloc(1, sizeof(*ep))) == NULL((void *)0))
191 err(1, NULL((void *)0));
192 *nextp = ep;
193 nextp = &(ep->next);
194 memcpy(&(ep->utmp), &utmp, sizeof(utmp));
195 if (!(stp = ttystat(ep->utmp.ut_line)))
196 continue;
197 ep->tdev = stp->st_rdev;
198
199 /*
200 * If this is the console device, attempt to ascertain
201 * the true console device dev_t.
202 */
203 if (ep->tdev == 0) {
204 int mib[2];
205 size_t size;
206
207 mib[0] = CTL_KERN1;
208 mib[1] = KERN_CONSDEV75;
209 size = sizeof(dev_t);
210 (void) sysctl(mib, 2, &ep->tdev, &size, NULL((void *)0), 0);
211 }
212
213 if ((ep->idle = now - stp->st_atimest_atim.tv_sec) < 0)
214 ep->idle = 0;
215 }
216 (void)fclose(ut);
217
218 if (header || wcmd == 0) {
219 pr_header(&now, nusers);
220 if (wcmd == 0)
221 exit (0);
222 }
223
224#define HEADER"USER TTY FROM LOGIN@ IDLE WHAT" "USER TTY FROM LOGIN@ IDLE WHAT"
225#define WUSED(sizeof("USER TTY FROM LOGIN@ IDLE WHAT") - sizeof
("WHAT")) (sizeof(HEADER"USER TTY FROM LOGIN@ IDLE WHAT") - sizeof("WHAT"))
226 if (header)
227 (void)puts(HEADER"USER TTY FROM LOGIN@ IDLE WHAT");
228
229 kp = kvm_getprocs(kd, KERN_PROC_ALL0, 0, sizeof(*kp), &nentries);
230 if (kp == NULL((void *)0))
231 errx(1, "%s", kvm_geterr(kd));
232
233 if ((ioctl(STDOUT_FILENO1, TIOCGWINSZ((unsigned long)0x40000000 | ((sizeof(struct winsize) & 0x1fff
) << 16) | ((('t')) << 8) | ((104))), &ws) == -1 &&
234 ioctl(STDERR_FILENO2, TIOCGWINSZ((unsigned long)0x40000000 | ((sizeof(struct winsize) & 0x1fff
) << 16) | ((('t')) << 8) | ((104))), &ws) == -1 &&
235 ioctl(STDIN_FILENO0, TIOCGWINSZ((unsigned long)0x40000000 | ((sizeof(struct winsize) & 0x1fff
) << 16) | ((('t')) << 8) | ((104))), &ws) == -1) || ws.ws_col == 0)
236 ttywidth = 79;
237 else
238 ttywidth = ws.ws_col - 1;
239 argwidth = ttywidth - WUSED(sizeof("USER TTY FROM LOGIN@ IDLE WHAT") - sizeof
("WHAT"));
240 if (argwidth < 4)
241 argwidth = 8;
242
243 for (i = 0; i < nentries; i++, kp++) {
244 if (kp->p_psflags & (PS_EMBRYO0x00020000 | PS_ZOMBIE0x00040000))
245 continue;
246 for (ep = ehead; ep != NULL((void *)0); ep = ep->next) {
247 /* ftp is a special case. */
248 if (strncmp(ep->utmp.ut_line, "ftp", 3) == 0) {
249 char pidstr[UT_LINESIZE8-2];
250 pid_t fp;
251
252 (void)strncpy(pidstr, &ep->utmp.ut_line[3],
253 sizeof(pidstr) - 1);
254 pidstr[sizeof(pidstr) - 1] = '\0';
255 fp = (pid_t)strtol(pidstr, NULL((void *)0), 10);
256 if (kp->p_pid == fp) {
257 ep->kp = kp;
258 break;
259 }
260 } else if (ep->tdev == kp->p_tdev &&
261 kp->p__pgid == kp->p_tpgid) {
262 /*
263 * Proc is in foreground of this terminal
264 */
265 if (proc_compare(ep->kp, kp))
266 ep->kp = kp;
267 break;
268 }
269 }
270 }
271 /* sort by idle time */
272 if (sortidle && ehead != NULL((void *)0)) {
273 struct entry *from = ehead, *save;
274
275 ehead = NULL((void *)0);
276 while (from != NULL((void *)0)) {
277 for (nextp = &ehead;
278 (*nextp) && from->idle >= (*nextp)->idle;
279 nextp = &(*nextp)->next)
280 continue;
281 save = from;
282 from = from->next;
283 save->next = *nextp;
284 *nextp = save;
285 }
286 }
287
288 if (!nflag) {
289 if (gethostname(domain, sizeof(domain)) == -1 ||
290 (p = strchr(domain, '.')) == 0)
291 domain[0] = '\0';
292 else {
293 domain[sizeof(domain) - 1] = '\0';
294 memmove(domain, p, strlen(p) + 1);
295 }
296 }
297
298 for (ep = ehead; ep != NULL((void *)0); ep = ep->next) {
299 p = *ep->utmp.ut_host ? ep->utmp.ut_host : "-";
300 for (x = NULL((void *)0), i = 0; p[i] != '\0' && i < UT_HOSTSIZE256; i++)
301 if (p[i] == ':') {
302 x = &p[i];
303 *x++ = '\0';
304 break;
305 }
306 if (!nflag && inet_aton(p, &addr) &&
307 (hp = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET2))) {
308 if (domain[0] != '\0') {
309 p = hp->h_name;
310 p += strlen(hp->h_name);
311 p -= strlen(domain);
312 if (p > hp->h_name &&
313 strcasecmp(p, domain) == 0)
314 *p = '\0';
315 }
316 p = hp->h_name;
317 }
318 if (x) {
319 (void)snprintf(buf, sizeof(buf), "%s:%.*s", p,
320 (int)(ep->utmp.ut_host + UT_HOSTSIZE256 - x), x);
321 p = buf;
322 }
323 (void)printf("%-*.*s %-2.2s %-*.*s ",
324 NAME_WIDTH8, UT_NAMESIZE32, ep->utmp.ut_name,
325 strncmp(ep->utmp.ut_line, "tty", 3) ?
326 ep->utmp.ut_line : ep->utmp.ut_line + 3,
327 HOST_WIDTH16, HOST_WIDTH16, *p ? p : "-");
328 pr_attime(&ep->utmp.ut_time, &now);
329 pr_idle(ep->idle);
330 pr_args(ep->kp);
331 printf("\n");
332 }
333 exit(0);
334}
335
336static void
337fmt_putc(int c, int *leftp)
338{
339
340 if (*leftp == 0)
341 return;
342 if (*leftp != -1)
343 *leftp -= 1;
344 putchar(c)(!__isthreaded ? __sputc(c, (&__sF[1])) : (putc)(c, (&
__sF[1])));
345}
346
347static void
348fmt_puts(const char *s, int *leftp)
349{
350 static char *v = NULL((void *)0);
351 static size_t maxlen = 0;
352 size_t len;
353
354 if (*leftp == 0)
355 return;
356 len = strlen(s) * 4 + 1;
357 if (len > maxlen) {
358 free(v);
359 maxlen = 0;
360 if (len < getpagesize())
361 len = getpagesize();
362 v = malloc(len);
363 if (v == NULL((void *)0))
364 return;
365 maxlen = len;
366 }
367 strvis(v, s, VIS_TAB0x08 | VIS_NL0x10 | VIS_CSTYLE0x02);
368 if (*leftp != -1) {
369 len = strlen(v);
370 if (len > *leftp) {
371 v[*leftp] = '\0';
372 *leftp = 0;
373 } else
374 *leftp -= len;
375 }
376 printf("%s", v);
377}
378
379
380static void
381pr_args(struct kinfo_proc *kp)
382{
383 char **argv, *str;
384 int left;
385
386 if (kp == NULL((void *)0))
387 goto nothing; /* no matching process found */
388 left = argwidth;
389 argv = kvm_getargv(kd, kp, argwidth+60); /* +60 for ftpd snip */
390 if (argv == NULL((void *)0))
391 goto nothing;
392
393 if (*argv == NULL((void *)0) || **argv == '\0') {
394 /* Process has zeroed argv[0], display executable name. */
395 fmt_putc('(', &left);
396 fmt_puts(kp->p_comm, &left);
397 fmt_putc(')', &left);
398 }
399 while (*argv) {
400 /*
401 * ftp argv[0] is in the following format:
402 * ftpd: HOSTNAME: [USER/PASS: ]CMD args (ftpd)
403 */
404 if (strncmp(*argv, "ftpd:", 5) == 0) {
405 if ((str = strchr(*argv + 5, ':')) != NULL((void *)0))
406 str = strchr(str + 1, ':');
407 if (str != NULL((void *)0)) {
408 if ((str[0] == ':') &&
409 isspace((unsigned char)str[1]))
410 str += 2;
411 fmt_puts(str, &left);
412 } else
413 fmt_puts(*argv, &left);
414 } else
415 fmt_puts(*argv, &left);
416 argv++;
417 fmt_putc(' ', &left);
418 }
419 return;
420nothing:
421 putchar('-')(!__isthreaded ? __sputc('-', (&__sF[1])) : (putc)('-', (
&__sF[1])));
422}
423
424static void
425pr_header(time_t *nowp, int nusers)
426{
427 double avenrun[3];
428 struct timespec boottime;
429 time_t uptime;
430 int days, hrs, i, mins;
431 char buf[256];
432
433 /*
434 * Print time of day.
435 */
436 (void)strftime(buf, sizeof(buf) - 1, "%l:%M%p", localtime(nowp));
437 buf[sizeof(buf) - 1] = '\0';
438 (void)printf("%s ", buf);
439
440 /*
441 * Print how long system has been up.
442 */
443 if (clock_gettime(CLOCK_BOOTTIME6, &boottime) != -1) {
444 uptime = boottime.tv_sec;
445 if (uptime > 59) {
446 uptime += 30;
447 days = uptime / SECSPERDAY(24 * 60 * 60);
448 uptime %= SECSPERDAY(24 * 60 * 60);
449 hrs = uptime / SECSPERHOUR(60 * 60);
450 uptime %= SECSPERHOUR(60 * 60);
451 mins = uptime / 60;
452 (void)printf(" up");
453 if (days > 0)
454 (void)printf(" %d day%s,", days,
455 days > 1 ? "s" : "");
456 if (hrs > 0 && mins > 0)
457 (void)printf(" %2d:%02d,", hrs, mins);
458 else {
459 if (hrs > 0)
460 (void)printf(" %d hr%s,",
461 hrs, hrs > 1 ? "s" : "");
462 if (mins > 0 || (days == 0 && hrs == 0))
463 (void)printf(" %d min%s,",
464 mins, mins != 1 ? "s" : "");
465 }
466 } else
467 printf(" %d secs,", (int)uptime);
468 }
469
470 /* Print number of users logged in to system */
471 (void)printf(" %d user%s", nusers, nusers != 1 ? "s" : "");
472
473 /*
474 * Print 1, 5, and 15 minute load averages.
475 */
476 if (getloadavg(avenrun, sizeof(avenrun) / sizeof(avenrun[0])) == -1)
477 (void)printf(", no load average information available\n");
478 else {
479 (void)printf(", load averages:");
480 for (i = 0; i < (sizeof(avenrun) / sizeof(avenrun[0])); i++) {
481 if (i > 0)
482 (void)printf(",");
483 (void)printf(" %.2f", avenrun[i]);
484 }
485 (void)printf("\n");
486 }
487}
488
489static struct stat *
490ttystat(char *line)
491{
492 static struct stat sb;
493 char ttybuf[sizeof(_PATH_DEV"/dev/") + UT_LINESIZE8];
494
495 /* Note, line may not be NUL-terminated */
496 (void)strlcpy(ttybuf, _PATH_DEV"/dev/", sizeof(ttybuf));
497 (void)strncat(ttybuf, line, sizeof(ttybuf) - 1 - strlen(ttybuf));
498 if (stat(ttybuf, &sb))
499 return (NULL((void *)0));
500 return (&sb);
501}
502
503static void
504usage(int wcmd)
505{
506 if (wcmd)
507 (void)fprintf(stderr(&__sF[2]),
508 "usage: w [-ahi] [-M core] [-N system] [user]\n");
509 else
510 (void)fprintf(stderr(&__sF[2]),
511 "usage: uptime\n");
512 exit (1);
513}