chiark / gitweb /
[PATCH] big libsysfs diet (pre 2.0 version)
[elogind.git] / libsysfs / sysfs_utils.c
index 699a982..9f6e18f 100644 (file)
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  *
  */
-#include "sysfs/libsysfs.h"
+#include "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
@@ -41,7 +32,7 @@ int sysfs_remove_trailing_slash(char *path)
 {
        char *c = NULL;
 
-       if (path == NULL) {
+       if (!path) {
                errno = EINVAL;
                return 1;
        }
@@ -56,59 +47,6 @@ int sysfs_remove_trailing_slash(char *path)
        return 0;
 }
 
-/**
- * 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)
-{
-#ifdef __KLIBC__
-       safestrncpy(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 || len == 0) {
-               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)) {
-                               safestrncpy(mnt_path, mntent->mnt_dir, len);
-                       } else {
-                               dprintf("Error - mount path too long\n");
-                               ret = -1;
-                       }
-               }
-       }
-       endmntent(mnt);
-       if (dirlen == 0 && ret == 0) {
-               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
-}
-
 /*
  * sysfs_get_mnt_path: Gets the sysfs mount point.
  * @mnt_path: place to put "sysfs" mount point
@@ -117,22 +55,21 @@ static int sysfs_get_fs_mnt_path(const char *fs_type,
  */
 int sysfs_get_mnt_path(char *mnt_path, size_t len)
 {
-       char *sysfs_path = NULL;
-       int ret = 0;
-
-       if (mnt_path == NULL || len == 0) {
-               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) {
-               safestrncpy(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;
+       return 0;
 }
 
 /**
@@ -145,8 +82,8 @@ 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 || len == 0) {
+
+       if (!path || !name || len == 0) {
                errno = EINVAL;
                return -1;
        }
@@ -166,10 +103,10 @@ int sysfs_get_name_from_path(const char *path, char *name, size_t len)
                }
        }
        n++;
-       safestrncpy(name, n, len);
+       safestrcpymax(name, n, len);
        return 0;
 }
-       
+
 /**
  * sysfs_get_link: returns link source
  * @path: symbolic link's path
@@ -184,7 +121,7 @@ int sysfs_get_link(const char *path, char *target, size_t len)
        char *d = NULL, *s = NULL;
        int slashes = 0, count = 0;
 
-       if (path == NULL || target == NULL || len == 0) {
+       if (!path || !target || len == 0) {
                errno = EINVAL;
                return -1;
        }
@@ -198,15 +135,15 @@ int sysfs_get_link(const char *path, char *target, size_t len)
                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);
@@ -221,11 +158,10 @@ int sysfs_get_link(const char *path, char *target, size_t len)
                        } else {
                                safestrcpy(temp_path, d);
                        }
-                       safestrncpy(target, temp_path, len);
+                       safestrcpymax(target, temp_path, len);
                        break;
-                       /* 
-                        * relative path  
-                        * getting rid of leading "../.." 
+                       /*
+                        * relative path, getting rid of leading "../.."
                         */
 parse_path:
                        while (*d == '/' || *d == '.') {
@@ -240,12 +176,12 @@ parse_path:
                                if (*s == '/')
                                        count++;
                        }
-                       safestrncpy(s, d, (SYSFS_PATH_MAX-strlen(devdir)));
-                       safestrncpy(target, devdir, len);
+                       safestrcpymax(s, d, (SYSFS_PATH_MAX-strlen(devdir)));
+                       safestrcpymax(target, devdir, len);
                        break;
                case '/':
                        /* absolute path - copy as is */
-                       safestrncpy(target, linkpath, len);
+                       safestrcpymax(target, linkpath, len);
                        break;
                default:
                        /* relative path from this directory */
@@ -257,164 +193,34 @@ parse_path:
                        } else {
                                safestrcpy(temp_path, linkpath);
                        }
-                       safestrncpy(target, temp_path, len);
+                       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);
-}
-
-
-/**
  * sysfs_close_list: generic list free routine
  * @list: dlist to free
  * Returns nothing
  */
 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(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;
-       
-       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, 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);
-                       safestrncpy(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';
-               safestrncpy(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);
-                       safestrncpy(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)
+ * 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)
 {
-       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);
+       if (!path)
                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);
-                       safestrncpy(device_name, cur->name, SYSFS_NAME_LEN);
-                       dlist_unshift_sorted(list, device_name, sort_char);
-               }
-       }
-       sysfs_close_directory(dir);
-       return list;
+       return (read_dir_subdirs(path));
 }
 
 /**
@@ -426,7 +232,7 @@ int sysfs_path_is_dir(const char *path)
 {
        struct stat astats;
 
-       if (path == NULL) {
+       if (!path) {
                errno = EINVAL;
                return 1;
        }
@@ -436,7 +242,7 @@ int sysfs_path_is_dir(const char *path)
        }
        if (S_ISDIR(astats.st_mode))
                return 0;
-               
+
        return 1;
 }
 
@@ -449,7 +255,7 @@ int sysfs_path_is_link(const char *path)
 {
        struct stat astats;
 
-       if (path == NULL) {
+       if (!path) {
                errno = EINVAL;
                return 1;
        }
@@ -459,7 +265,7 @@ int sysfs_path_is_link(const char *path)
        }
        if (S_ISLNK(astats.st_mode))
                return 0;
-               
+
        return 1;
 }
 
@@ -472,7 +278,7 @@ int sysfs_path_is_file(const char *path)
 {
        struct stat astats;
 
-       if (path == NULL) {
+       if (!path) {
                errno = EINVAL;
                return 1;
        }
@@ -482,6 +288,6 @@ int sysfs_path_is_file(const char *path)
        }
        if (S_ISREG(astats.st_mode))
                return 0;
-               
+
        return 1;
 }