X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev_rules.c;h=d1c3f042c390ce5dd4c913a664159ffce350f1c2;hp=8a2066d70931dee89a915d13b92d7360584c5e7f;hb=1bcfb137e838a9fa8c607aa2e88b1b1f0716f296;hpb=27b77df44daebbd7597c572343105c16de099233

diff --git a/udev_rules.c b/udev_rules.c
index 8a2066d70..d1c3f042c 100644
--- a/udev_rules.c
+++ b/udev_rules.c
@@ -364,6 +364,8 @@ void udev_rules_apply_format(struct udevice *udev, char *string, size_t maxsize)
 						goto found;
 					}
 				}
+				head[0] = '$';
+				err("unknown format variable '%s'", head);
 			} else if (head[0] == '%') {
 				/* substitute format char */
 				if (head[1] == '\0')
@@ -385,6 +387,8 @@ void udev_rules_apply_format(struct udevice *udev, char *string, size_t maxsize)
 						goto found;
 					}
 				}
+				head[0] = '%';
+				err("unknown format char '%c'", tail[0]);
 			}
 			head++;
 		}
@@ -458,30 +462,42 @@ found:
 			}
 			break;
 		case SUBST_ATTR:
-			if (attr == NULL) {
-				dbg("missing attribute");
-				break;
-			} else {
-				struct sysfs_device *dev_parent;
-				const char *value;
+			if (attr == NULL)
+				err("missing file parameter for attr");
+			else {
+				const char *value = NULL;
+				size_t size;
+
+				/* first try the current device, other matches may have selected */
+				if (udev->dev_parent != NULL && udev->dev_parent != udev->dev)
+					value = sysfs_attr_get_value(udev->dev_parent->devpath, attr);
+
+				/* look at all devices along the chain of parents */
+				if (value == NULL) {
+					struct sysfs_device *dev_parent = udev->dev;
+
+					do {
+						dbg("looking at '%s'", dev_parent->devpath);
+						value = sysfs_attr_get_value(dev_parent->devpath, attr);
+						if (value != NULL) {
+							strlcpy(temp2, value, sizeof(temp2));
+							break;
+						}
+						dev_parent = sysfs_device_get_parent(dev_parent);
+					} while (dev_parent != NULL);
+				}
 
-				dev_parent = udev->dev;
-				do {
-					dbg("looking at '%s'", dev_parent->devpath);
-					value = sysfs_attr_get_value(dev_parent->devpath, attr);
-					if (value != NULL) {
-						strlcpy(temp2, value, sizeof(temp2));
-						break;
-					}
-					dev_parent = sysfs_device_get_parent(dev_parent);
-				} while (dev_parent != NULL);
+				if (value == NULL)
+					break;
 
-				/* strip trailing whitespace of sysfs value */
-				i = strlen(temp2);
-				while (i > 0 && isspace(temp2[i-1]))
-					temp2[--i] = '\0';
+				/* strip trailing whitespace and replace untrusted characters of sysfs value */
+				size = strlcpy(temp2, value, sizeof(temp2));
+				if (size >= sizeof(temp2))
+					size = sizeof(temp2)-1;
+				while (size > 0 && isspace(temp2[size-1]))
+					temp2[--size] = '\0';
 				count = replace_untrusted_chars(temp2);
-				if (count)
+				if (count > 0)
 					info("%i untrusted character(s) replaced" , count);
 				strlcat(string, temp2, maxsize);
 				dbg("substitute sysfs value '%s'", temp2);
@@ -542,7 +558,7 @@ found:
 			break;
 		}
 		/* possibly truncate to format-char specified length */
-		if (len != -1) {
+		if (len >= 0 && len < (int)strlen(head)) {
 			head[len] = '\0';
 			dbg("truncate to %i chars, subtitution string becomes '%s'", len, head);
 		}
@@ -693,7 +709,7 @@ static int match_rule(struct udevice *udev, struct udev_rule *rule)
 		if (match_key("DRIVERS", rule, &rule->drivers, udev->dev_parent->driver))
 			goto try_parent;
 
-		/* check for matching sysfs attrubute pairs */
+		/* check for matching sysfs attribute pairs */
 		for (i = 0; i < rule->attrs.count; i++) {
 			struct key_pair *pair = &rule->attrs.keys[i];
 
@@ -802,13 +818,19 @@ try_parent:
 		struct key_pair *pair = &rule->env.keys[i];
 
 		if (pair->key.operation == KEY_OP_ASSIGN) {
+			char temp_value[NAME_SIZE];
 			const char *key_name = key_pair_name(rule, pair);
 			const char *value = key_val(rule, &pair->key);
-			char *key_value = name_list_key_add(&udev->env_list, key_name, value);
+			char *key_value;
+
+			/* make sure we don't write to the same string we possibly read from */
+			strlcpy(temp_value, value, sizeof(temp_value));
+			udev_rules_apply_format(udev, temp_value, NAME_SIZE);
+
+			key_value = name_list_key_add(&udev->env_list, key_name, temp_value);
 			if (key_value == NULL)
 				break;
 
-			udev_rules_apply_format(udev, key_value, NAME_SIZE);
 			putenv(key_value);
 			dbg("export ENV '%s'", key_value);
 		}