chiark / gitweb /
[PATCH] big libsysfs diet (pre 2.0 version)
[elogind.git] / libsysfs / sysfs_utils.c
index 009ae94..9f6e18f 100644 (file)
  */
 #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;
 }
 
 /**
@@ -123,18 +78,17 @@ 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);
+       safestrcpy(tmp, path);
        n = strrchr(tmp, '/');
        if (n == NULL) {
                errno = EINVAL;
@@ -149,7 +103,7 @@ int sysfs_get_name_from_path(const unsigned char *path, unsigned char *name,
                }
        }
        n++;
-       strncpy(name, n, len);
+       safestrcpymax(name, n, len);
        return 0;
 }
 
@@ -159,61 +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
@@ -221,140 +205,22 @@ 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)
-{
-       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;
-       
-       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;
-       }
-       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_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);
-                       strcpy(subsys_name, cur->name);
-                       dlist_unshift(list, subsys_name);
-               }
-       }
-       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;
-               strcpy(c, SYSFS_BLOCK_NAME);
-               if ((sysfs_path_is_dir(sysfs_path)) == 0) {
-                       subsys_name = (char *)calloc(1, SYSFS_NAME_LEN);
-                       strcpy(subsys_name, SYSFS_BLOCK_NAME);
-                       dlist_unshift(list, subsys_name);
-               }
-       }
-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(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], *device_name = NULL;
-       struct sysfs_directory *dir = NULL;
-       struct sysfs_link *cur = NULL;
-       struct dlist *list = NULL;
-       
-       if (name == NULL)
+       if (!path)
                return NULL;
 
-       if (sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX) != 0) {
-               dprintf("Error getting sysfs mount point\n");
-               return NULL;
-       }
-
-       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, "/");
-       strcat(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);
-                       strcpy(device_name, cur->name);
-                       dlist_unshift(list, device_name);
-               }
-       }
-       sysfs_close_directory(dir);
-       return list;
+       return (read_dir_subdirs(path));
 }
 
 /**
@@ -362,11 +228,11 @@ struct dlist *sysfs_open_bus_devices_list(unsigned char *name)
  * @path: path to validate
  * Returns 0 if path points to dir, 1 otherwise
  */
-int sysfs_path_is_dir(const unsigned char *path)
+int sysfs_path_is_dir(const char *path)
 {
        struct stat astats;
 
-       if (path == NULL) {
+       if (!path) {
                errno = EINVAL;
                return 1;
        }
@@ -385,11 +251,11 @@ int sysfs_path_is_dir(const unsigned char *path)
  * @path: path to validate
  * Returns 0 if path points to link, 1 otherwise
  */
-int sysfs_path_is_link(const unsigned char *path)
+int sysfs_path_is_link(const char *path)
 {
        struct stat astats;
 
-       if (path == NULL) {
+       if (!path) {
                errno = EINVAL;
                return 1;
        }
@@ -408,11 +274,11 @@ int sysfs_path_is_link(const unsigned char *path)
  * @path: path to validate
  * Returns 0 if path points to file, 1 otherwise
  */
-int sysfs_path_is_file(const unsigned char *path)
+int sysfs_path_is_file(const char *path)
 {
        struct stat astats;
 
-       if (path == NULL) {
+       if (!path) {
                errno = EINVAL;
                return 1;
        }