X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=libsysfs%2Fsysfs_utils.c;h=9f6e18f665dd592cdb9de80ef9830e78880cd477;hp=627e618dceaf699dd811e091e09980126d4e711f;hb=f385ff6512012a75b8381938dd3f55f991b53e9a;hpb=edcd336477880368915245a4b7ddd1bca5940b30

diff --git a/libsysfs/sysfs_utils.c b/libsysfs/sysfs_utils.c
index 627e618dc..9f6e18f66 100644
--- a/libsysfs/sysfs_utils.c
+++ b/libsysfs/sysfs_utils.c
@@ -1,5 +1,5 @@
 /*
- * syfs_utils.c
+ * sysfs_utils.c
  *
  * System utility functions for libsysfs
  *
@@ -22,74 +22,28 @@
  */
 #include "libsysfs.h"
 #include "sysfs.h"
-#ifndef __KLIBC__
-#include <mntent.h>
-#endif
 
 /**
- * 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 unsigned char *fs_type, 
-				unsigned 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)
 {
-#ifdef __KLIBC__
-	strcpy(mnt_path, "/sys");
-	return 0;
-#else
-	FILE *mnt;
-	struct mntent *mntent;
-	int ret = 0;
-	size_t dirlen = 0;
+	char *c = NULL;
 
-	/* check arg */
-	if (fs_type == NULL || mnt_path == NULL) {
+	if (!path) {
 		errno = EINVAL;
-		return -1;
-	}
-
-	if ((mnt = setmntent(SYSFS_PROC_MNTS, "r")) == NULL) {
-		dprintf("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("Error - mount path too long\n");
-				ret = -1;
-			}
-		}
+		return 1;
 	}
-	endmntent(mnt);
-	if (dirlen == 0 && ret == 0) {
-		dprintf("Filesystem %s not found!\n", fs_type);
+	c = strrchr(path, '/');
+	if (c == NULL) {
+		dprintf("Invalid path %s\n", path);
 		errno = EINVAL;
-		ret = -1;
-	}
-	return ret;
-#endif
-}
-
-/*
- * sysfs_trailing_slash: checks if there's a trailing slash to path
- * @path: path to check
- * returns 1 if true and 0 if not
- */
-int sysfs_trailing_slash(unsigned char *path)
-{
-	unsigned char *s = NULL;
-
-	if (path == NULL)
-		return 0;
-	s = &path[strlen(path)-1];
-	if (strncmp(s, "/", 1) == 0)
 		return 1;
+	}
+	if (*(c+1) == '\0') 
+		*c = '\0';
 	return 0;
 }
 
@@ -99,22 +53,23 @@ int sysfs_trailing_slash(unsigned char *path)
  * @len: size of mnt_path
  * returns 0 with success and -1 with error.
  */
-int sysfs_get_mnt_path(unsigned char *mnt_path, size_t len)
+int sysfs_get_mnt_path(char *mnt_path, size_t len)
 {
-	char *sysfs_path = NULL;
-	int ret = 0;
-
-	if (mnt_path == NULL) {
-		errno = EINVAL;
-		return -1;
+	static char sysfs_path[SYSFS_PATH_MAX] = "";
+	const char *sysfs_path_env;
+
+	/* 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);
+			return 0;
+		}
+		safestrcpymax(mnt_path, SYSFS_MNT_PATH, len);
 	}
-	sysfs_path = getenv(SYSFS_PATH_ENV);
-	if (sysfs_path != NULL) 
-		strncpy(mnt_path, sysfs_path, len);
-	else
-		ret = sysfs_get_fs_mnt_path(SYSFS_FSTYPE_NAME, mnt_path, len);
 
-	return ret;
+	return 0;
 }
 
 /**
@@ -123,29 +78,32 @@ int sysfs_get_mnt_path(unsigned char *mnt_path, size_t len)
  * @name: where to put name
  * @len: size of name
  */
-int sysfs_get_name_from_path(const unsigned char *path, unsigned char *name, 
-								size_t len)
+int sysfs_get_name_from_path(const char *path, char *name, size_t len)
 {
-	unsigned char tmp[SYSFS_PATH_MAX];
-	unsigned char *n = NULL;
-                                                                                
-	if (path == NULL || name == NULL) {
+	char tmp[SYSFS_PATH_MAX];
+	char *n = NULL;
+
+	if (!path || !name || len == 0) {
 		errno = EINVAL;
 		return -1;
 	}
 	memset(tmp, 0, SYSFS_PATH_MAX);
-	strcpy(tmp, path);
-	n = &tmp[strlen(tmp)-1];
-	if (strncmp(n, "/", 1) == 0)
-		*n = '\0';	
+	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;
 }
 
@@ -155,61 +113,91 @@ int sysfs_get_name_from_path(const unsigned char *path, unsigned char *name,
  * @target: where to put name
  * @len: size of name
  */
-int sysfs_get_link(const unsigned char *path, unsigned char *target, size_t len)
+int sysfs_get_link(const char *path, char *target, size_t len)
 {
-	unsigned char devdir[SYSFS_PATH_MAX];
-	unsigned char linkpath[SYSFS_PATH_MAX];
-	unsigned char *d = NULL, *s = NULL;
+	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;
 
-	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);
-	strncpy(devdir, path, SYSFS_PATH_MAX);
+	memset(temp_path, 0, SYSFS_PATH_MAX);
+	safestrcpy(devdir, path);
 
 	if ((readlink(path, linkpath, SYSFS_PATH_MAX)) < 0) {
 		return -1;
 	}
-									        
 	d = linkpath;
-
-	/* getting rid of leading "../.." */	
-	while (*d == '/' || *d == '.') {
-		if (*d == '/')
-			slashes++;
-		d++;
-	}
-
-	d--;
-
-	s = &devdir[strlen(devdir)-1];
-	while (s != NULL && count != (slashes+1)) {
-		s--;
-		if (*s == '/')
-			count++;
+	/*
+	 * 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);
 	}
-	
-	strncpy(s, d, (SYSFS_PATH_MAX-strlen(devdir)));
-	strncpy(target, devdir, len);
-
 	return 0;
 }
 
-
-/**
- * sysfs_del_name: free function for sysfs_open_subsystem_list
- * @name: memory area to be freed
- */ 
-static void sysfs_del_name(void *name)
-{
-	free(name);
-}
-
-
 /**
  * sysfs_close_list: generic list free routine
  * @list: dlist to free
@@ -217,144 +205,89 @@ static void sysfs_del_name(void *name)
  */
 void sysfs_close_list(struct dlist *list)
 {
-	if (list != NULL)
+	if (list)
 		dlist_destroy(list);
 }
 
 /**
- * sysfs_open_subsystem_list: gets a list of all supported "name" subsystem
- * 	details from the system
- * @name: name of the subsystem, eg., "bus", "class", "devices"
- * Returns a dlist of supported names or NULL if subsystem not supported
- */ 
-struct dlist *sysfs_open_subsystem_list(unsigned char *name)
+ * 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)
 {
-	unsigned char sysfs_path[SYSFS_PATH_MAX], *subsys_name = NULL;
-	unsigned char *c = NULL;
-	struct sysfs_directory *dir = NULL, *cur = NULL;
-	struct dlist *list = NULL;
-	struct stat astats;
-	
-	if (name == NULL)
-		return NULL;
-
-	if (sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX) != 0) {
-		dprintf("Error getting sysfs mount point\n");
+	if (!path)
 		return NULL;
-	}
-
-	if (sysfs_trailing_slash(sysfs_path) == 0)
-		strcat(sysfs_path, "/");
-	strcat(sysfs_path, name);
-	dir = sysfs_open_directory(sysfs_path);
-	if (dir == NULL) {
-		dprintf("Error opening sysfs_directory at %s\n", sysfs_path);
-		return NULL;
-	}
 
-	if (sysfs_read_directory(dir) != 0) {
-		dprintf("Error reading sysfs_directory at %s\n", sysfs_path);
-		sysfs_close_directory(dir);
-		return NULL;
-	}
+	return (read_dir_subdirs(path));
+}
 
-	if (dir->subdirs != NULL) {
-		list = dlist_new_with_delete(SYSFS_NAME_LEN,
-				sysfs_del_name);
-		if (list == NULL) {
-			dprintf("Error creating list\n");
-			sysfs_close_directory(dir);
-			return NULL;
-		}
+/**
+ * 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;
 
-		dlist_for_each_data(dir->subdirs, cur,
-				struct sysfs_directory) {
-			subsys_name = (char *)calloc(1, SYSFS_NAME_LEN);
-			strcpy(subsys_name, cur->name);
-			dlist_unshift(list, subsys_name);
-		}
+	if (!path) {
+		errno = EINVAL;
+		return 1;
 	}
-	sysfs_close_directory(dir);
-	/*
-	 * We are now considering "block" as a "class". Hence, if the subsys
-	 * name requested here is "class", verify if "block" is supported on
-	 * this system and return the same.
-	 */ 
-	if (strcmp(name, SYSFS_CLASS_DIR) == 0) {
-		c = strstr(sysfs_path, SYSFS_CLASS_NAME);
-		if (c == NULL)
-			goto out;
-		strcpy(c, SYSFS_BLOCK_NAME);
-		if ((lstat(sysfs_path, &astats)) != 0) {
-			dprintf("stat() failed\n");
-			goto out;
-		}
-		if (S_ISDIR(astats.st_mode)) {
-			subsys_name = (char *)calloc(1, SYSFS_NAME_LEN);
-			strcpy(subsys_name, SYSFS_BLOCK_NAME);
-			dlist_unshift(list, subsys_name);
-		}
+	if ((lstat(path, &astats)) != 0) {
+		dprintf("stat() failed\n");
+		return 1;
 	}
-out:
-	return list;
-}
+	if (S_ISDIR(astats.st_mode))
+		return 0;
 
+	return 1;
+}
 
 /**
- * sysfs_open_bus_devices_list: gets a list of all devices on "name" bus
- * @name: name of the subsystem, eg., "pci", "scsi", "usb"
- * Returns a dlist of supported names or NULL if subsystem not supported
- */ 
-struct dlist *sysfs_open_bus_devices_list(unsigned char *name)
+ * 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)
 {
-	unsigned char sysfs_path[SYSFS_PATH_MAX], *device_name = NULL;
-	struct sysfs_directory *dir = NULL;
-	struct sysfs_link *cur = NULL;
-	struct dlist *list = NULL;
-	
-	if (name == NULL)
-		return NULL;
+	struct stat astats;
 
-	if (sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX) != 0) {
-		dprintf("Error getting sysfs mount point\n");
-		return NULL;
+	if (!path) {
+		errno = EINVAL;
+		return 1;
 	}
-
-	if (sysfs_trailing_slash(sysfs_path) == 0)
-		strcat(sysfs_path, "/");
-	strcat(sysfs_path, SYSFS_BUS_NAME);
-	strcat(sysfs_path, "/");
-	strcat(sysfs_path, name);
-	strcat(sysfs_path, SYSFS_DEVICES_DIR);
-	dir = sysfs_open_directory(sysfs_path);
-	if (dir == NULL) {
-		dprintf("Error opening sysfs_directory at %s\n", sysfs_path);
-		return NULL;
+	if ((lstat(path, &astats)) != 0) {
+		dprintf("stat() failed\n");
+		return 1;
 	}
+	if (S_ISLNK(astats.st_mode))
+		return 0;
 
-	if (sysfs_read_directory(dir) != 0) {
-		dprintf("Error reading sysfs_directory at %s\n", sysfs_path);
-		sysfs_close_directory(dir);
-		return NULL;
-	}
+	return 1;
+}
 
-	if (dir->links != NULL) {
-		list = dlist_new_with_delete(SYSFS_NAME_LEN,
-				sysfs_del_name);
-		if (list == NULL) {
-			dprintf("Error creating list\n");
-			sysfs_close_directory(dir);
-			return NULL;
-		}
+/**
+ * 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;
 
-		dlist_for_each_data(dir->links, cur,
-				struct sysfs_link) {
-			device_name = (char *)calloc(1, SYSFS_NAME_LEN);
-			strcpy(device_name, cur->name);
-			dlist_unshift(list, device_name);
-		}
+	if (!path) {
+		errno = EINVAL;
+		return 1;
 	}
-	sysfs_close_directory(dir);
-	return list;
-}
+	if ((lstat(path, &astats)) != 0) {
+		dprintf("stat() failed\n");
+		return 1;
+	}
+	if (S_ISREG(astats.st_mode))
+		return 0;
 
+	return 1;
+}