X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=libsysfs%2Fsysfs_utils.c;h=bd7f99ae15d6c0417f492e7e72ef981bf8de3af3;hb=7a551dc35580988d13ff8e6e3e37398ac779181a;hp=a2410abe69003dc40414be63161093697b13830c;hpb=070f54223f66490e9d25719c495e074f77da8985;p=elogind.git

diff --git a/libsysfs/sysfs_utils.c b/libsysfs/sysfs_utils.c
index a2410abe6..bd7f99ae1 100644
--- a/libsysfs/sysfs_utils.c
+++ b/libsysfs/sysfs_utils.c
@@ -1,9 +1,9 @@
 /*
- * syfs_utils.c
+ * sysfs_utils.c
  *
  * System utility functions for libsysfs
  *
- * Copyright (C) 2003 International Business Machines, Inc.
+ * Copyright (C) IBM Corp. 2003-2005
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
@@ -24,49 +24,23 @@
 #include "sysfs.h"
 
 /**
- * sysfs_get_mnt_path: Gets the mount point for specified filesystem.
- * @fs_type: filesystem type to retrieve mount point
- * @mnt_path: place to put the retrieved mount path
- * @len: size of mnt_path
- * returns 0 with success and -1 with error.
- */
-static int sysfs_get_fs_mnt_path(const char *fs_type, char *mnt_path, 
-				 size_t len)
+ * sysfs_remove_trailing_slash: Removes any trailing '/' in the given path
+ * @path: Path to look for the trailing '/'
+ * Returns 0 on success 1 on error
+ */ 
+int sysfs_remove_trailing_slash(char *path)
 {
-	FILE *mnt;
-	struct mntent *mntent;
-	int ret = 0;
-	size_t dirlen = 0;
+	size_t len;
 
-	/* check arg */
-	if (fs_type == NULL || mnt_path == NULL) {
+	if (!path) {
 		errno = EINVAL;
-		return -1;
+		return 1;
 	}
 
-	if ((mnt = setmntent(SYSFS_PROC_MNTS, "r")) == NULL) {
-		dprintf(stderr, "Error getting mount information\n");
-		return -1;
-	}
-	while (ret == 0 && dirlen == 0 && (mntent = getmntent(mnt)) != NULL) {
-		if (strcmp(mntent->mnt_type, fs_type) == 0) {
-			dirlen = strlen(mntent->mnt_dir);
-			if (dirlen <= (len - 1)) {
-				strcpy(mnt_path, mntent->mnt_dir);
-			} else {
-				dprintf(stderr, 
-					"Error - mount path too long\n");
-				ret = -1;
-			}
-		}
-	}
-	endmntent(mnt);
-	if (dirlen == 0 && ret == 0) {
-		dprintf(stderr, "Filesystem %s not found!\n", fs_type);
-		errno = EINVAL;
-		ret = -1;
-	}
-	return ret;
+	len = strlen(path);
+	while (len > 0 && path[len-1] == '/')
+		path[--len] = '\0';
+	return 0;
 }
 
 /*
@@ -77,14 +51,22 @@ static int sysfs_get_fs_mnt_path(const char *fs_type, char *mnt_path,
  */
 int sysfs_get_mnt_path(char *mnt_path, size_t len)
 {
-	int ret = -1;
+	static char sysfs_path[SYSFS_PATH_MAX] = "";
+	const char *sysfs_path_env;
 
-	if (mnt_path != NULL)
-		ret = sysfs_get_fs_mnt_path(SYSFS_FSTYPE_NAME, mnt_path, len);
-	else
-		errno = EINVAL;
+	/* evaluate only at the first call */
+	if (sysfs_path[0] == '\0') {
+		/* possible overrride of real mount path */
+		sysfs_path_env = getenv(SYSFS_PATH_ENV);
+		if (sysfs_path_env != NULL) {
+			safestrcpymax(mnt_path, sysfs_path_env, len);
+			sysfs_remove_trailing_slash(mnt_path);
+			return 0;
+		}
+		safestrcpymax(mnt_path, SYSFS_MNT_PATH, len);
+	}
 
-	return ret;
+	return 0;
 }
 
 /**
@@ -95,20 +77,30 @@ int sysfs_get_mnt_path(char *mnt_path, size_t len)
  */
 int sysfs_get_name_from_path(const char *path, char *name, size_t len)
 {
+	char tmp[SYSFS_PATH_MAX];
 	char *n = NULL;
-                                                                                
-	if (path == NULL || name == NULL) {
+
+	if (!path || !name || len == 0) {
 		errno = EINVAL;
 		return -1;
 	}
-	n = strrchr(path, '/');
+	memset(tmp, 0, SYSFS_PATH_MAX);
+	safestrcpy(tmp, path);
+	n = strrchr(tmp, '/');
 	if (n == NULL) {
 		errno = EINVAL;
 		return -1;
 	}
+	if (*(n+1) == '\0') {
+		*n = '\0';
+		n = strrchr(tmp, '/');
+		if (n == NULL) {
+			errno = EINVAL;
+			return -1;
+		}
+	}
 	n++;
-	strncpy(name, n, len);
-
+	safestrcpymax(name, n, len);
 	return 0;
 }
 
@@ -122,35 +114,177 @@ int sysfs_get_link(const char *path, char *target, size_t len)
 {
 	char devdir[SYSFS_PATH_MAX];
 	char linkpath[SYSFS_PATH_MAX];
-	char *d = NULL;
+	char temp_path[SYSFS_PATH_MAX];
+	char *d = NULL, *s = NULL;
+	int slashes = 0, count = 0;
 
-	if (path == NULL || target == NULL) {
+	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 ((sysfs_get_mnt_path(devdir, SYSFS_PATH_MAX)) != 0) {
-		dprintf(stderr, "Sysfs not supported on this system\n");
-		return -1;
-	}
-								        
 	if ((readlink(path, linkpath, SYSFS_PATH_MAX)) < 0) {
 		return -1;
 	}
-									        
 	d = linkpath;
+	/*
+	 * 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 '.': 
+			/*
+			 * 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;
+			/*
+			 * relative path, getting rid of leading "../.."
+			 */
+parse_path:
+			while (*d == '/' || *d == '.') {
+				if (*d == '/')
+					slashes++;
+				d++;
+			}
+			d--;
+			s = &devdir[strlen(devdir)-1];
+			while (s != NULL && count != (slashes+1)) {
+				s--;
+				if (*s == '/')
+					count++;
+			}
+			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);
+			}
+			safestrcpymax(target, temp_path, len);
+	}
+	return 0;
+}
+
+/**
+ * sysfs_close_list: generic list free routine
+ * @list: dlist to free
+ * Returns nothing
+ */
+void sysfs_close_list(struct dlist *list)
+{
+	if (list)
+		dlist_destroy(list);
+}
 
-	/* getting rid of leading "../.." */	
-	while (*d == '/' || *d == '.')
-		d++;
+/**
+ * sysfs_open_directory_list: gets a list of all directories under "path"
+ * @path: path to read
+ * Returns a dlist of supported names or NULL no directories (errno is set
+ * 	in case of error
+ */
+struct dlist *sysfs_open_directory_list(const char *path)
+{
+	if (!path)
+		return NULL;
 
-	d--;
-	
-	strcat(devdir, d);
-	strncpy(target, devdir, len);
+	return (read_dir_subdirs(path));
+}
 
-	return 0;
+/**
+ * sysfs_path_is_dir: Check if the path supplied points to a directory
+ * @path: path to validate
+ * Returns 0 if path points to dir, 1 otherwise
+ */
+int sysfs_path_is_dir(const char *path)
+{
+	struct stat astats;
+
+	if (!path) {
+		errno = EINVAL;
+		return 1;
+	}
+	if ((stat(path, &astats)) != 0) {
+		dprintf("stat() failed\n");
+		return 1;
+	}
+	if (S_ISDIR(astats.st_mode))
+		return 0;
+
+	return 1;
+}
+
+/**
+ * sysfs_path_is_link: Check if the path supplied points to a link
+ * @path: path to validate
+ * Returns 0 if path points to link, 1 otherwise
+ */
+int sysfs_path_is_link(const char *path)
+{
+	struct stat astats;
+
+	if (!path) {
+		errno = EINVAL;
+		return 1;
+	}
+	if ((lstat(path, &astats)) != 0) {
+		dprintf("stat() failed\n");
+		return 1;
+	}
+	if (S_ISLNK(astats.st_mode))
+		return 0;
+
+	return 1;
+}
+
+/**
+ * sysfs_path_is_file: Check if the path supplied points to a file
+ * @path: path to validate
+ * Returns 0 if path points to file, 1 otherwise
+ */
+int sysfs_path_is_file(const char *path)
+{
+	struct stat astats;
+
+	if (!path) {
+		errno = EINVAL;
+		return 1;
+	}
+	if ((lstat(path, &astats)) != 0) {
+		dprintf("stat() failed\n");
+		return 1;
+	}
+	if (S_ISREG(astats.st_mode))
+		return 0;
+
+	return 1;
 }