sysfsutils/SOURCES/sysfsutils-2.1.0-get_link.patch
2021-10-08 17:01:28 +00:00

165 lines
3.9 KiB
Diff

diff -upr sysfsutils-2.1.0-old/lib/sysfs_utils.c sysfsutils-2.1.0/lib/sysfs_utils.c
--- sysfsutils-2.1.0-old/lib/sysfs_utils.c 2006-08-07 07:08:01.000000000 +0200
+++ sysfsutils-2.1.0/lib/sysfs_utils.c 2008-05-13 07:42:50.000000000 +0200
@@ -117,84 +117,104 @@ int sysfs_get_link(const char *path, cha
{
char devdir[SYSFS_PATH_MAX];
char linkpath[SYSFS_PATH_MAX];
- char temp_path[SYSFS_PATH_MAX];
- char *d = NULL, *s = NULL;
- int slashes = 0, count = 0;
+ char *d, *s;
+ int count;
if (!path || !target || len == 0) {
errno = EINVAL;
return -1;
}
- memset(devdir, 0, SYSFS_PATH_MAX);
- memset(linkpath, 0, SYSFS_PATH_MAX);
- memset(temp_path, 0, SYSFS_PATH_MAX);
- safestrcpy(devdir, path);
-
- if ((readlink(path, linkpath, SYSFS_PATH_MAX)) < 0) {
+ count = readlink(path, linkpath, SYSFS_PATH_MAX);
+ if (count < 0)
return -1;
- }
- d = linkpath;
+ else
+ linkpath[count] = '\0';
/*
* Three cases here:
* 1. relative path => format ../..
* 2. absolute path => format /abcd/efgh
* 3. relative path _from_ this dir => format abcd/efgh
*/
- switch (*d) {
- case '.':
+ if (*linkpath == '/') {
+ /* absolute path - copy as is */
+ safestrcpymax(target, linkpath, len);
+ return 0;
+ }
+
+ safestrcpy(devdir, path);
+ s = strrchr(devdir, '/');
+ if (s == NULL)
+ s = devdir - 1;
+ d = linkpath;
+ while (*d == '.') {
+ if (*(d+1) == '/') {
/*
* handle the case where link is of type ./abcd/xxx
*/
- safestrcpy(temp_path, devdir);
- if (*(d+1) == '/')
- d += 2;
- else if (*(d+1) == '.')
- goto parse_path;
- s = strrchr(temp_path, '/');
- if (s != NULL) {
- *(s+1) = '\0';
- safestrcat(temp_path, d);
- } else {
- safestrcpy(temp_path, d);
- }
- safestrcpymax(target, temp_path, len);
- break;
+ d += 2;
+ while (*d == '/')
+ d++;
+ continue;
+ } else if (*(d+1) != '.' || *(d+2) != '/')
/*
- * relative path, getting rid of leading "../.."
+ * relative path from this directory, starting
+ * with a hidden directory
*/
-parse_path:
- while (*d == '/' || *d == '.') {
- if (*d == '/')
- slashes++;
- d++;
- }
- d--;
- s = &devdir[strlen(devdir)-1];
- while (s != NULL && count != (slashes+1)) {
+ break;
+
+ /*
+ * relative path, getting rid of leading "../.."; must
+ * be careful here since any path component of devdir
+ * could be a symlink again
+ */
+ for (;;) {
+ while (s > devdir && *s == '/') {
s--;
- if (*s == '/')
- count++;
+ if (*s == '.'
+ && (s == devdir || *(s-1) == '/'))
+ s--;
}
- safestrcpymax(s, d, (SYSFS_PATH_MAX-strlen(devdir)));
- safestrcpymax(target, devdir, len);
- break;
- case '/':
- /* absolute path - copy as is */
- safestrcpymax(target, linkpath, len);
- break;
- default:
- /* relative path from this directory */
- safestrcpy(temp_path, devdir);
- s = strrchr(temp_path, '/');
- if (s != NULL) {
- *(s+1) = '\0';
- safestrcat(temp_path, linkpath);
- } else {
- safestrcpy(temp_path, linkpath);
+ *(s+1) = '\0';
+ if (*devdir == '\0' || sysfs_path_is_link(devdir))
+ /*
+ * condition will be true eventually
+ * because we already know that all
+ * but the last component of path
+ * resolve to a directory
+ */
+ break;
+ if (sysfs_get_link(devdir, devdir, SYSFS_PATH_MAX))
+ return -1;
+ s = devdir + strlen(devdir) - 1;
+ }
+ while (s >= devdir) {
+ if (*s == '/') {
+ if (*(s+1) != '.' || *(s+2) != '.'
+ || *(s+3) != '\0') {
+ d += 3;
+ while (*d == '/')
+ d++;
+ } else
+ s += 2;
+ break;
}
- safestrcpymax(target, temp_path, len);
+ s--;
+ }
+ if (s < devdir || *(s+1) == '\0')
+ break;
}
+
+ /*
+ * appending to devdir a slash and the (possibly shortened)
+ * relative path to the link source
+ */
+ s++;
+ if (s > devdir && *s == '\0')
+ *s++ = '/';
+ *s = '\0';
+ safestrcpymax(s, d, SYSFS_PATH_MAX-(s-devdir));
+ safestrcpymax(target, devdir, len);
return 0;
}