--- /dev/null
+/*
+ * ntp_realpath.c - get real path for a file
+ * Juergen Perlinger (perlinger@ntp.org) for the NTP project.
+ * Feb 11, 2014 for the NTP project.
+ *
+ * This is a butchered version of FreeBSD's implementation of 'realpath()',
+ * and the following copyright applies:
+ *----------------------------------------------------------------------
+ */
+
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 2003 Constantin S. Svintsoff <kostik@iclub.nsu.ru>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The names of the authors may not be used to endorse or promote
+ * products derived from this software without specific prior written
+ * permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include "ntp_stdlib.h"
+
+/* ================================================================== */
+#if !defined(SYS_WINNT) && !defined(HAVE_FUNC_POSIX_REALPATH)
+
+#include <sys/stat.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+/* The following definitions are to avoid system settings with excessive
+ * values for maxmimum path length and symlink chains/loops. Adjust with
+ * care, if that's ever needed: some buffers are on the stack!
+ */
+#define NTP_PATH_MAX 1024
+#define NTP_MAXSYMLINKS 16
+
+/*
+ * Find the real name of path, by removing all ".", ".." and symlink
+ * components. Returns (resolved) on success, or (NULL) on failure,
+ * in which case the path which caused trouble is left in (resolved).
+ */
+static char *
+realpath1(const char *path, char *resolved)
+{
+ struct stat sb;
+ char *p, *q;
+ size_t left_len, resolved_len, next_token_len;
+ unsigned symlinks;
+ ssize_t slen;
+ char left[NTP_PATH_MAX], next_token[NTP_PATH_MAX], symlink[NTP_PATH_MAX];
+
+ symlinks = 0;
+ if (path[0] == '/') {
+ resolved[0] = '/';
+ resolved[1] = '\0';
+ if (path[1] == '\0')
+ return (resolved);
+ resolved_len = 1;
+ left_len = strlcpy(left, path + 1, sizeof(left));
+ } else {
+ if (getcwd(resolved, NTP_PATH_MAX) == NULL) {
+ resolved[0] = '.';
+ resolved[1] = '\0';
+ return (NULL);
+ }
+ resolved_len = strlen(resolved);
+ left_len = strlcpy(left, path, sizeof(left));
+ }
+ if (left_len >= sizeof(left) || resolved_len >= NTP_PATH_MAX) {
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+
+ /*
+ * Iterate over path components in `left'.
+ */
+ while (left_len != 0) {
+ /*
+ * Extract the next path component and adjust `left'
+ * and its length.
+ */
+ p = strchr(left, '/');
+
+ next_token_len = p != NULL ? (size_t)(p - left) : left_len;
+ memcpy(next_token, left, next_token_len);
+ next_token[next_token_len] = '\0';
+
+ if (p != NULL) {
+ left_len -= next_token_len + 1;
+ memmove(left, p + 1, left_len + 1);
+ } else {
+ left[0] = '\0';
+ left_len = 0;
+ }
+
+ if (resolved[resolved_len - 1] != '/') {
+ if (resolved_len + 1 >= NTP_PATH_MAX) {
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+ resolved[resolved_len++] = '/';
+ resolved[resolved_len] = '\0';
+ }
+ if (next_token[0] == '\0') {
+ /* Handle consequential slashes. */
+ continue;
+ } else if (strcmp(next_token, ".") == 0) {
+ continue;
+ } else if (strcmp(next_token, "..") == 0) {
+ /*
+ * Strip the last path component except when we have
+ * single "/"
+ */
+ if (resolved_len > 1) {
+ resolved[resolved_len - 1] = '\0';
+ q = strrchr(resolved, '/') + 1;
+ *q = '\0';
+ resolved_len = q - resolved;
+ }
+ continue;
+ }
+
+ /*
+ * Append the next path component and lstat() it.
+ */
+ resolved_len = strlcat(resolved, next_token, NTP_PATH_MAX);
+ if (resolved_len >= NTP_PATH_MAX) {
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+ if (lstat(resolved, &sb) != 0)
+ return (NULL);
+ if (S_ISLNK(sb.st_mode)) {
+ if (symlinks++ > NTP_MAXSYMLINKS) {
+ errno = ELOOP;
+ return (NULL);
+ }
+ slen = readlink(resolved, symlink, sizeof(symlink));
+ if (slen <= 0 || slen >= (ssize_t)sizeof(symlink)) {
+ if (slen < 0)
+ ; /* keep errno from readlink(2) call */
+ else if (slen == 0)
+ errno = ENOENT;
+ else
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+ symlink[slen] = '\0';
+ if (symlink[0] == '/') {
+ resolved[1] = 0;
+ resolved_len = 1;
+ } else {
+ /* Strip the last path component. */
+ q = strrchr(resolved, '/') + 1;
+ *q = '\0';
+ resolved_len = q - resolved;
+ }
+
+ /*
+ * If there are any path components left, then
+ * append them to symlink. The result is placed
+ * in `left'.
+ */
+ if (p != NULL) {
+ if (symlink[slen - 1] != '/') {
+ if (slen + 1 >= (ssize_t)sizeof(symlink)) {
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+ symlink[slen] = '/';
+ symlink[slen + 1] = 0;
+ }
+ left_len = strlcat(symlink, left,
+ sizeof(symlink));
+ if (left_len >= sizeof(symlink)) {
+ errno = ENAMETOOLONG;
+ return (NULL);
+ }
+ }
+ left_len = strlcpy(left, symlink, sizeof(left));
+ } else if (!S_ISDIR(sb.st_mode) && p != NULL) {
+ errno = ENOTDIR;
+ return (NULL);
+ }
+ }
+
+ /*
+ * Remove trailing slash except when the resolved pathname
+ * is a single "/".
+ */
+ if (resolved_len > 1 && resolved[resolved_len - 1] == '/')
+ resolved[resolved_len - 1] = '\0';
+ return (resolved);
+}
+
+#endif /* !defined(SYS_WINNT) && !defined(HAVE_POSIX_REALPATH) */
+/* ================================================================== */
+
+char *
+ntp_realpath(const char * path)
+{
+ char *res, *m;
+
+# if defined(SYS_WINNT)
+
+ (void)m;
+ if (path == NULL) {
+ errno = EINVAL;
+ return (NULL);
+ }
+ if (path[0] == '\0') {
+ errno = ENOENT;
+ return (NULL);
+ }
+
+ return strdup(path); /* this clearly needs some work! */
+
+# elif defined(HAVE_FUNC_POSIX_REALPATH)
+
+ (void)m;
+ return realpath(path, NULL);
+
+# else
+
+ if (path == NULL) {
+ errno = EINVAL;
+ return (NULL);
+ }
+ if (path[0] == '\0') {
+ errno = ENOENT;
+ return (NULL);
+ }
+
+ m = malloc(NTP_PATH_MAX);
+ if (m == NULL)
+ return (NULL);
+
+ res = realpath1(path, m);
+ if (res != NULL)
+ res = realloc(res, strlen(res) + 1);
+ if (res == NULL)
+ free(m);
+
+# endif
+
+ return (res);
+}
{
clockprocT * const pp = peer->procptr;
gpsd_unitT * up;
- gpsd_unitT ** uscan = &s_clock_units;
+ gpsd_unitT ** uscan = &s_clock_units;
- struct stat sb;
+ struct stat sb;
+ char * devname = NULL;
/* check if we can proceed at all or if init failed */
if ( ! gpsd_init_check())
* practicable, we will have to read the symlink, if
* any, so we can get the true device file.)
*/
- if (-1 == myasprintf(&up->device, "%s%u",
+ if (-1 == myasprintf(&devname, "%s%u",
s_dev_stem, up->unit)) {
msyslog(LOG_ERR, "%s: clock device name too long",
up->logname);
goto dev_fail;
}
- if (-1 == stat(up->device, &sb) || !S_ISCHR(sb.st_mode)) {
+ up->device = ntp_realpath(devname);
+ if (NULL == up->device) {
+ msyslog(LOG_ERR, "%s: '%s' has no absolute path",
+ up->logname, devname);
+ goto dev_fail;
+ }
+ if (-1 == lstat(up->device, &sb)) {
+ msyslog(LOG_ERR, "%s: '%s' not accessible",
+ up->logname, up->device);
+ goto dev_fail;
+ }
+ if (!S_ISCHR(sb.st_mode)) {
msyslog(LOG_ERR, "%s: '%s' is not a character device",
up->logname, up->device);
goto dev_fail;
}
+ free(devname);
+ devname = NULL;
} else {
/* All set up, just increment use count. */
++up->refcount;
dev_fail:
/* On failure, remove all UNIT ressources and declare defeat. */
-
+ free(devname);
INSIST (up);
if (!--up->refcount) {
*uscan = up->next_unit;
}
}
+
#else
NONEMPTY_TRANSLATION_UNIT
#endif /* REFCLOCK && CLOCK_GPSDJSON */
projects / thirdparty / ntp.git / commitdiff
