procps/pwdx.c
Qualys Security Advisory f69d54f05b 0021-pwdx: Fix a misleading comment.
It sounds like an off-by-one, but the code itself is correct.
2018-06-23 21:59:14 +10:00

150 lines
3.5 KiB
C

/*
* pwdx.c - print process working directory
* Copyright 2004 Nicholas Miell
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <errno.h>
#include <getopt.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include "c.h"
#include "nls.h"
#include "xalloc.h"
#include "fileutils.h"
static void __attribute__ ((__noreturn__)) usage(FILE * out)
{
fputs(USAGE_HEADER, out);
fprintf(out, _(" %s [options] pid...\n"), program_invocation_short_name);
fputs(USAGE_OPTIONS, out);
fputs(USAGE_HELP, out);
fputs(USAGE_VERSION, out);
fprintf(out, USAGE_MAN_TAIL("pwdx(1)"));
exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
}
int check_pid_argument(char *input)
{
int skip = 0;
long pid;
char *end = NULL;
if (!strncmp("/proc/", input, 6))
skip = 6;
errno = 0;
pid = strtol(input + skip, &end, 10);
if (errno || input + skip == end || (end && *end))
return 1;
if (pid < 1)
return 1;
return 0;
}
int main(int argc, char *argv[])
{
int ch;
int retval = 0, i;
ssize_t alloclen = 128;
char *pathbuf;
static const struct option longopts[] = {
{"version", no_argument, 0, 'V'},
{"help", no_argument, 0, 'h'},
{NULL, 0, 0, 0}
};
#ifdef HAVE_PROGRAM_INVOCATION_NAME
program_invocation_name = program_invocation_short_name;
#endif
setlocale (LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
atexit(close_stdout);
while ((ch = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1)
switch (ch) {
case 'V':
printf(PROCPS_NG_VERSION);
return EXIT_SUCCESS;
case 'h':
usage(stdout);
default:
usage(stderr);
}
argc -= optind;
argv += optind;
if (argc == 0)
usage(stderr);
pathbuf = xmalloc(alloclen);
for (i = 0; i < argc; i++) {
char *s;
ssize_t len, buflen;
/* Constant 10 is the length of strings "/proc/" + "/cwd" */
char *buf;
buflen = 10 + strlen(argv[i]) + 1;
buf = xmalloc(buflen);
if (check_pid_argument(argv[i]))
xerrx(EXIT_FAILURE, _("invalid process id: %s"),
argv[i]);
/*
* At this point, all arguments are in the form
* /proc/NNNN or NNNN, so a simple check based on
* the first char is possible
*/
if (argv[i][0] != '/')
snprintf(buf, buflen, "/proc/%s/cwd", argv[i]);
else
snprintf(buf, buflen, "%s/cwd", argv[i]);
/*
* buf contains /proc/NNNN/cwd symlink name
* on entry, the target of that symlink on return
*/
while ((len = readlink(buf, pathbuf, alloclen)) == alloclen) {
alloclen *= 2;
pathbuf = xrealloc(pathbuf, alloclen);
}
free(buf);
if (len < 0) {
s = strerror(errno == ENOENT ? ESRCH : errno);
retval = EXIT_FAILURE;
fprintf(stderr, "%s: %s\n", argv[i], s);
continue;
} else {
pathbuf[len] = 0;
s = pathbuf;
}
printf("%s: %s\n", argv[i], s);
}
free(pathbuf);
return retval;
}