[PATCH] more Libsysfs updates

On Thu, Mar 11, 2004 at 02:36:23PM +0100, Kay Sievers wrote:
> On Thu, 2004-03-11 at 15:02, Ananth N Mavinakayanahalli wrote:
> > On Thu, Mar 11, 2004 at 02:04:36PM +0100, Kay Sievers wrote:
> > > On Thu, Mar 11, 2004 at 11:53:50AM +0500, Ananth N Mavinakayanahalli wrote:
> > >
> > > > +#define safestrcpy(to, from)	strncpy(to, from, sizeof(to)-1)
> > > > +#define safestrcat(to, from)	strncat(to, from, sizeof(to) - strlen(to)-1)
> > >
> > > These strings are not terminated with '\0' if from is longer than
> > > the sizeof to.
> >
> > Did not do it on purpose as the "to" elements are either calloc'd or memset to
> > '0' explicitly in the library. Thats the reason I mentioned "scaled down" :)
>
> Ahh, sounds good.
>
> > > > +#define safestrncpy(to, from, maxsize) \
> > > > +do { \
> > > > +	to[maxsize-1] = '\0'; \
> > > > +	strncpy(to, from, maxsize-1); \
> > > > +} while (0)
> > > > +
> > > > +#define safestrncat(to, from, maxsize) \
> > > > +do { \
> > > > +	to[maxsize-1] = '\0'; \
> > > > +	strncat(to, from, maxsize - strlen(to)-1); \
> > > > +} while (0)
> > >
> > > We all expect a similar behavior like strncat/strncpy according to the
> > > names, but these macros are limiting by the target size and do not limit
> > > the count of chars copied.
> > > This is confusing I think and suggest using a different name like
> > > 'safestrcopymax()' or something.
> >
> > Good point.. will make the change
>
> Nice. I've had these *n* names too and I forgot about the logic and only
> 10 days later I introduced a ugly bug cause I can't limit the count of
> copied chars :)

Inlined is the patch for this... applies on the earlier _BIG_ patch.

7 files changed, 40 insertions, 40 deletions

diff --git a/libsysfs/sysfs/libsysfs.h b/libsysfs/sysfs/libsysfs.h
index cbde2f5783..11cffae045 100644
--- a/libsysfs/sysfs/libsysfs.h
+++ b/libsysfs/sysfs/libsysfs.h
@@ -32,16 +32,16 @@
 #define safestrcpy(to, from)	strncpy(to, from, sizeof(to)-1)
 #define safestrcat(to, from)	strncat(to, from, sizeof(to) - strlen(to)-1)
 
-#define safestrncpy(to, from, maxsize) \
+#define safestrcpymax(to, from, max) \
 do { \
-	to[maxsize-1] = '\0'; \
-	strncpy(to, from, maxsize-1); \
+	to[max-1] = '\0'; \
+	strncpy(to, from, max-1); \
 } while (0)
 
-#define safestrncat(to, from, maxsize) \
+#define safestrcatmax(to, from, max) \
 do { \
-	to[maxsize-1] = '\0'; \
-	strncat(to, from, maxsize - strlen(to)-1); \
+	to[max-1] = '\0'; \
+	strncat(to, from, max - strlen(to)-1); \
 } while (0)
 
 /*
diff --git a/libsysfs/sysfs_bus.c b/libsysfs/sysfs_bus.c
index bff7f78f05..9ca23c85d8 100644
--- a/libsysfs/sysfs_bus.c
+++ b/libsysfs/sysfs_bus.c
@@ -384,7 +384,7 @@ int sysfs_find_driver_bus(const char *driver, char *busname, size_t bsize)
 			if (drivers != NULL) {
 				dlist_for_each_data(drivers, curdrv, char) {
 					if (strcmp(driver, curdrv) == 0) {
-						safestrncpy(busname, 
+						safestrcpymax(busname, 
 								bus, bsize);
 						sysfs_close_list(drivers);
 						sysfs_close_list(buslist);
diff --git a/libsysfs/sysfs_class.c b/libsysfs/sysfs_class.c
index 7a696355ca..59ef0be48e 100644
--- a/libsysfs/sysfs_class.c
+++ b/libsysfs/sysfs_class.c
@@ -509,16 +509,16 @@ static int get_classdev_path(const char *classname, const char *clsdev,
 	}
 	if (strncmp(classname, SYSFS_BLOCK_NAME,
 				sizeof(SYSFS_BLOCK_NAME)) == 0) {
-		safestrncat(path, "/", len);
-		safestrncat(path, SYSFS_BLOCK_NAME, len);
+		safestrcatmax(path, "/", len);
+		safestrcatmax(path, SYSFS_BLOCK_NAME, len);
 	} else {
-		safestrncat(path, "/", len);
-		safestrncat(path, SYSFS_CLASS_NAME, len);
-		safestrncat(path, "/", len);
-		safestrncat(path, classname, len);
+		safestrcatmax(path, "/", len);
+		safestrcatmax(path, SYSFS_CLASS_NAME, len);
+		safestrcatmax(path, "/", len);
+		safestrcatmax(path, classname, len);
 	}
-	safestrncat(path, "/", len);
-	safestrncat(path, clsdev, len);
+	safestrcatmax(path, "/", len);
+	safestrcatmax(path, clsdev, len);
 	return 0;
 }
 
diff --git a/libsysfs/sysfs_device.c b/libsysfs/sysfs_device.c
index e3a8977016..290fd9723e 100644
--- a/libsysfs/sysfs_device.c
+++ b/libsysfs/sysfs_device.c
@@ -53,7 +53,7 @@ static int get_dev_driver(struct sysfs_device *dev)
 	if (c == NULL)
 		return 1;
 	*c = '\0';
-	safestrncat(c, path, (sizeof(devpath) - strlen(devpath)));
+	safestrcatmax(c, path, (sizeof(devpath) - strlen(devpath)));
 
 	drvlist = sysfs_open_subsystem_list(path);
 	if (drvlist != NULL) {
diff --git a/libsysfs/sysfs_dir.c b/libsysfs/sysfs_dir.c
index be54a1cf86..8ce8522200 100644
--- a/libsysfs/sysfs_dir.c
+++ b/libsysfs/sysfs_dir.c
@@ -239,10 +239,10 @@ int sysfs_write_attribute(struct sysfs_attribute *sysattr,
 			sysattr->value = (char *)realloc
 				(sysattr->value, length);
 			sysattr->len = length;
-			safestrncpy(sysattr->value, new_value, length);
+			safestrcpymax(sysattr->value, new_value, length);
 		} else {
 			/*"length" of the new value is same as old one */ 
-			safestrncpy(sysattr->value, new_value, length);
+			safestrcpymax(sysattr->value, new_value, length);
 		}
 	}
 			
@@ -348,7 +348,7 @@ int sysfs_read_attribute_value(const char *attrpath,
 	if (length > vsize) 
 		dprintf("Value length %d is larger than supplied buffer %d\n",
 			length, vsize);
-	safestrncpy(value, attr->value, vsize);
+	safestrcpymax(value, attr->value, vsize);
 	sysfs_close_attribute(attr);
 
 	return 0;
diff --git a/libsysfs/sysfs_driver.c b/libsysfs/sysfs_driver.c
index 9ffa9c9077..2439b7a567 100644
--- a/libsysfs/sysfs_driver.c
+++ b/libsysfs/sysfs_driver.c
@@ -335,14 +335,14 @@ static int get_driver_path(const char *bus, const char *drv,
 		dprintf("Error getting sysfs mount path\n");
 		return -1;
 	}
-	safestrncat(path, "/", psize);
-	safestrncat(path, SYSFS_BUS_NAME, psize);
-	safestrncat(path, "/", psize);
-	safestrncat(path, bus, psize);
-	safestrncat(path, "/", psize);
-	safestrncat(path, SYSFS_DRIVERS_NAME, psize);
-	safestrncat(path, "/", psize);
-	safestrncat(path, drv, psize);
+	safestrcatmax(path, "/", psize);
+	safestrcatmax(path, SYSFS_BUS_NAME, psize);
+	safestrcatmax(path, "/", psize);
+	safestrcatmax(path, bus, psize);
+	safestrcatmax(path, "/", psize);
+	safestrcatmax(path, SYSFS_DRIVERS_NAME, psize);
+	safestrcatmax(path, "/", psize);
+	safestrcatmax(path, drv, psize);
 	return 0;
 }
 
diff --git a/libsysfs/sysfs_utils.c b/libsysfs/sysfs_utils.c
index 699a9829b8..492c7fa668 100644
--- a/libsysfs/sysfs_utils.c
+++ b/libsysfs/sysfs_utils.c
@@ -67,7 +67,7 @@ static int sysfs_get_fs_mnt_path(const char *fs_type,
 				char *mnt_path, size_t len)
 {
 #ifdef __KLIBC__
-	safestrncpy(mnt_path, "/sys", len);
+	safestrcpymax(mnt_path, "/sys", len);
 	return 0;
 #else
 	FILE *mnt;
@@ -89,7 +89,7 @@ static int sysfs_get_fs_mnt_path(const char *fs_type,
 		if (strcmp(mntent->mnt_type, fs_type) == 0) {
 			dirlen = strlen(mntent->mnt_dir);
 			if (dirlen <= (len - 1)) {
-				safestrncpy(mnt_path, mntent->mnt_dir, len);
+				safestrcpymax(mnt_path, mntent->mnt_dir, len);
 			} else {
 				dprintf("Error - mount path too long\n");
 				ret = -1;
@@ -126,7 +126,7 @@ int sysfs_get_mnt_path(char *mnt_path, size_t len)
 	}
 	sysfs_path = getenv(SYSFS_PATH_ENV);
 	if (sysfs_path != NULL) {
-		safestrncpy(mnt_path, sysfs_path, len);
+		safestrcpymax(mnt_path, sysfs_path, len);
 		if ((sysfs_remove_trailing_slash(mnt_path)) != 0)
 			return 1;
 	} else
@@ -166,7 +166,7 @@ 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;
 }
 	
@@ -221,7 +221,7 @@ 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  
@@ -240,12 +240,12 @@ 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 */
@@ -257,7 +257,7 @@ parse_path:
 			} else {
 				safestrcpy(temp_path, linkpath);
 			}
-			safestrncpy(target, temp_path, len);
+			safestrcpymax(target, temp_path, len);
 	}
 	return 0;
 }
@@ -330,7 +330,7 @@ struct dlist *sysfs_open_subsystem_list(char *name)
 		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);
+			safestrcpymax(subsys_name, cur->name, SYSFS_NAME_LEN);
 			dlist_unshift_sorted(list, subsys_name, sort_char);
 		}
 	}
@@ -345,11 +345,11 @@ struct dlist *sysfs_open_subsystem_list(char *name)
 		if (c == NULL)
 			goto out;
 		*c = '\0';
-		safestrncpy(c, SYSFS_BLOCK_NAME, 
+		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);
-			safestrncpy(subsys_name, SYSFS_BLOCK_NAME, 
+			safestrcpymax(subsys_name, SYSFS_BLOCK_NAME, 
 					SYSFS_NAME_LEN);
 			dlist_unshift_sorted(list, subsys_name, sort_char);
 		}
@@ -409,7 +409,7 @@ struct dlist *sysfs_open_bus_devices_list(char *name)
 		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);
+			safestrcpymax(device_name, cur->name, SYSFS_NAME_LEN);
 			dlist_unshift_sorted(list, device_name, sort_char);
 		}
 	}