X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=libsysfs%2Fsysfs_utils.c;h=492c7fa668e5dd3ec445d29085e6ce70ab05f091;hp=a2410abe69003dc40414be63161093697b13830c;hb=656703759d7d3eac6e8c86f1121cde7dfd6d8cbd;hpb=070f54223f66490e9d25719c495e074f77da8985

diff --git a/libsysfs/sysfs_utils.c b/libsysfs/sysfs_utils.c
index a2410abe6..492c7fa66 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
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
@@ -20,53 +20,93 @@
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  *
  */
-#include "libsysfs.h"
+#include "sysfs/libsysfs.h"
 #include "sysfs.h"
+#ifndef __KLIBC__
+#include <mntent.h>
+#endif
+
+static int sort_char(void *new_elem, void *old_elem)
+{
+	return ((strncmp((char *)new_elem, (char *)old_elem, 
+			strlen((char *)new_elem))) < 0 ? 1 : 0);
+}
+
+/**
+ * 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)
+{
+	char *c = NULL;
+
+	if (path == NULL) {
+		errno = EINVAL;
+		return 1;
+	}
+	c = strrchr(path, '/');
+	if (c == NULL) {
+		dprintf("Invalid path %s\n", path);
+		errno = EINVAL;
+		return 1;
+	}
+	if (*(c+1) == '\0') 
+		*c = '\0';
+	return 0;
+}
 
 /**
- * sysfs_get_mnt_path: Gets the mount point for specified filesystem.
+ * sysfs_get_fs_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)
+static int sysfs_get_fs_mnt_path(const char *fs_type, 
+				char *mnt_path, size_t len)
 {
+#ifdef __KLIBC__
+	safestrcpymax(mnt_path, "/sys", len);
+	return 0;
+#else
 	FILE *mnt;
 	struct mntent *mntent;
 	int ret = 0;
 	size_t dirlen = 0;
 
 	/* check arg */
-	if (fs_type == NULL || mnt_path == NULL) {
+	if (fs_type == NULL || mnt_path == NULL || len == 0) {
 		errno = EINVAL;
 		return -1;
 	}
 
 	if ((mnt = setmntent(SYSFS_PROC_MNTS, "r")) == NULL) {
-		dprintf(stderr, "Error getting mount information\n");
+		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);
+				safestrcpymax(mnt_path, mntent->mnt_dir, len);
 			} else {
-				dprintf(stderr, 
-					"Error - mount path too long\n");
+				dprintf("Error - mount path too long\n");
 				ret = -1;
 			}
 		}
 	}
 	endmntent(mnt);
 	if (dirlen == 0 && ret == 0) {
-		dprintf(stderr, "Filesystem %s not found!\n", fs_type);
+		dprintf("Filesystem %s not found!\n", fs_type);
 		errno = EINVAL;
 		ret = -1;
 	}
+	if ((sysfs_remove_trailing_slash(mnt_path)) != 0)
+		ret = -1;
+	
 	return ret;
+#endif
 }
 
 /*
@@ -77,12 +117,20 @@ 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;
+	char *sysfs_path = NULL;
+	int ret = 0;
 
-	if (mnt_path != NULL)
-		ret = sysfs_get_fs_mnt_path(SYSFS_FSTYPE_NAME, mnt_path, len);
-	else
+	if (mnt_path == NULL || len == 0) {
 		errno = EINVAL;
+		return -1;
+	}
+	sysfs_path = getenv(SYSFS_PATH_ENV);
+	if (sysfs_path != NULL) {
+		safestrcpymax(mnt_path, sysfs_path, len);
+		if ((sysfs_remove_trailing_slash(mnt_path)) != 0)
+			return 1;
+	} else
+		ret = sysfs_get_fs_mnt_path(SYSFS_FSTYPE_NAME, mnt_path, len);
 
 	return ret;
 }
@@ -95,23 +143,33 @@ 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 == NULL || name == NULL || 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;
 }
-
+	
 /**
  * sysfs_get_link: returns link source
  * @path: symbolic link's path
@@ -122,35 +180,308 @@ 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 == NULL || target == NULL || 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_del_name: free function for sysfs_open_subsystem_list
+ * @name: memory area to be freed
+ */ 
+static void sysfs_del_name(void *name)
+{
+	free(name);
+}
 
-	/* getting rid of leading "../.." */	
-	while (*d == '/' || *d == '.')
-		d++;
 
-	d--;
+/**
+ * sysfs_close_list: generic list free routine
+ * @list: dlist to free
+ * Returns nothing
+ */
+void sysfs_close_list(struct dlist *list)
+{
+	if (list != NULL)
+		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(char *name)
+{
+	char sysfs_path[SYSFS_PATH_MAX], *subsys_name = NULL;
+	char *c = NULL;
+	struct sysfs_directory *dir = NULL, *cur = NULL;
+	struct dlist *list = NULL;
 	
-	strcat(devdir, d);
-	strncpy(target, devdir, len);
+	if (name == NULL)
+		return NULL;
 
-	return 0;
+	if (sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX) != 0) {
+		dprintf("Error getting sysfs mount point\n");
+		return NULL;
+	}
+
+	safestrcat(sysfs_path, "/");
+	safestrcat(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_dir_subdirs(dir)) != 0) {
+		dprintf("Error reading sysfs_directory at %s\n", sysfs_path);
+		sysfs_close_directory(dir);
+		return NULL;
+	}
+
+	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;
+		}
+
+		dlist_for_each_data(dir->subdirs, cur,
+				struct sysfs_directory) {
+			subsys_name = (char *)calloc(1, SYSFS_NAME_LEN);
+			safestrcpymax(subsys_name, cur->name, SYSFS_NAME_LEN);
+			dlist_unshift_sorted(list, subsys_name, sort_char);
+		}
+	}
+	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_NAME) == 0) {
+		c = strstr(sysfs_path, SYSFS_CLASS_NAME);
+		if (c == NULL)
+			goto out;
+		*c = '\0';
+		safestrcpymax(c, SYSFS_BLOCK_NAME, 
+				sizeof(sysfs_path) - strlen(sysfs_path));
+		if ((sysfs_path_is_dir(sysfs_path)) == 0) {
+			subsys_name = (char *)calloc(1, SYSFS_NAME_LEN);
+			safestrcpymax(subsys_name, SYSFS_BLOCK_NAME, 
+					SYSFS_NAME_LEN);
+			dlist_unshift_sorted(list, subsys_name, sort_char);
+		}
+	}
+out:
+	return list;
+}
+
+
+/**
+ * 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(char *name)
+{
+	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;
+
+	if (sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX) != 0) {
+		dprintf("Error getting sysfs mount point\n");
+		return NULL;
+	}
+
+	safestrcat(sysfs_path, "/");
+	safestrcat(sysfs_path, SYSFS_BUS_NAME);
+	safestrcat(sysfs_path, "/");
+	safestrcat(sysfs_path, name);
+	safestrcat(sysfs_path, "/");
+	safestrcat(sysfs_path, SYSFS_DEVICES_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_dir_links(dir)) != 0) {
+		dprintf("Error reading sysfs_directory at %s\n", sysfs_path);
+		sysfs_close_directory(dir);
+		return NULL;
+	}
+
+	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;
+		}
+
+		dlist_for_each_data(dir->links, cur,
+				struct sysfs_link) {
+			device_name = (char *)calloc(1, SYSFS_NAME_LEN);
+			safestrcpymax(device_name, cur->name, SYSFS_NAME_LEN);
+			dlist_unshift_sorted(list, device_name, sort_char);
+		}
+	}
+	sysfs_close_directory(dir);
+	return list;
+}
+
+/**
+ * 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 == NULL) {
+		errno = EINVAL;
+		return 1;
+	}
+	if ((lstat(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 == NULL) {
+		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 == NULL) {
+		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;
 }