squashfs-tools: Add mount-point flag

This flag is necessary when android-fs-config or context-file are passed
and the source directory is not mount point (e.g. absolute
path, current dir '.', different dir name than mount point...etc).

Change-Id: I3b4bdc401527765a571ff4e5fb5815c6d5e85adc
Signed-off-by: Mohamad Ayyash <mkayyash@google.com>

4 files changed, 63 insertions, 5 deletions

diff --git a/squashfs-tools/android.c b/squashfs-tools/android.c
index a59c210..aaf91b5 100644
--- a/squashfs-tools/android.c
+++ b/squashfs-tools/android.c
@@ -33,6 +33,16 @@
 
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
 
+void alloc_mounted_path(const char *mount_point, const char *subpath, char **mounted_path) {
+    *mounted_path = malloc(strlen(mount_point) + strlen(subpath) + 1);
+    if (*mounted_path == NULL) {
+        perror("Malloc Failure.");
+        exit(EXIT_FAILURE);
+    }
+    strcpy(*mounted_path, mount_point);
+    strcat(*mounted_path, subpath);
+}
+
 void android_fs_config(const char *path, struct stat *stat) {
     unsigned long capabilities = 0;
     fs_config(path, S_ISDIR(stat->st_mode), &stat->st_uid, &stat->st_gid, &stat->st_mode,
diff --git a/squashfs-tools/android.h b/squashfs-tools/android.h
index 766cf0a..b290b8e 100644
--- a/squashfs-tools/android.h
+++ b/squashfs-tools/android.h
@@ -17,6 +17,7 @@
 #ifndef _ANDROID_H_
 #define _ANDROID_H_
 
+void alloc_mounted_path(const char *mount_point, const char *subpath, char **mounted_path);
 void android_fs_config(const char *path, struct stat *stat);
 struct selabel_handle *get_sehnd(const char *context_file);
 char *set_selabel(const char *path, unsigned int mode, struct selabel_handle *sehnd);
diff --git a/squashfs-tools/mksquashfs.c b/squashfs-tools/mksquashfs.c
index 11401e2..9e80d0a 100644
--- a/squashfs-tools/mksquashfs.c
+++ b/squashfs-tools/mksquashfs.c
@@ -82,6 +82,7 @@
 #include "android.h"
 int android_config = FALSE;
 char *context_file = NULL;
+char *mount_point = NULL;
 #endif
 /* ANDROID CHANGES END */
 
@@ -3049,8 +3050,16 @@ inline void add_dir_entry(struct dir_ent *dir_ent, struct dir_info *sub_dir,
 
 /* ANDROID CHANGES START*/
 #ifdef ANDROID
-	if (android_config)
-		android_fs_config(pathname(dir_ent), &inode_info->buf);
+	if (android_config) {
+		if (mount_point) {
+			char *mounted_path;
+			alloc_mounted_path(mount_point, subpathname(dir_ent), &mounted_path);
+			android_fs_config(mounted_path, &inode_info->buf);
+			free(mounted_path);
+		} else {
+			android_fs_config(pathname(dir_ent), &inode_info->buf);
+		}
+	}
 #endif
 /* ANDROID CHANGES END */
 
@@ -3062,6 +3071,16 @@ inline void add_dir_entry(struct dir_ent *dir_ent, struct dir_info *sub_dir,
 	dir->count++;
 }
 
+/* ANDROID CHANGES START*/
+#ifdef ANDROID
+/* Weird linker bug that complains those inline functions are undefined. */
+extern inline void add_dir_entry(struct dir_ent *dir_ent, struct dir_info *sub_dir,
+	struct inode_info *inode_info);
+extern inline void add_dir_entry2(char *name, char *source_name,
+	char *nonstandard_pathname, struct dir_info *sub_dir,
+	struct inode_info *inode_info, struct dir_info *dir);
+#endif
+/* ANDROID CHANGES END */
 
 inline void add_dir_entry2(char *name, char *source_name,
 	char *nonstandard_pathname, struct dir_info *sub_dir,
@@ -3138,7 +3157,10 @@ void dir_scan(squashfs_inode *inode, char *pathname,
 /* ANDROID CHANGES START*/
 #ifdef ANDROID
 		if (android_config)
-			android_fs_config(pathname, &buf);
+			if (mount_point)
+				android_fs_config(mount_point, &buf);
+			else
+				android_fs_config(pathname, &buf);
 #endif
 /* ANDROID CHANGES END */
 		dir_ent->inode = lookup_inode(&buf);
@@ -5573,6 +5595,14 @@ print_compressor_options:
 #ifdef ANDROID
 		else if(strcmp(argv[i], "-android-fs-config") == 0)
 			android_config = TRUE;
+		else if(strcmp(argv[i], "-mount-point") == 0) {
+			if(++i == argc) {
+				ERROR("%s: -mount-point: missing mount point name\n",
+					argv[0]);
+				exit(1);
+			}
+			mount_point = argv[i];
+		}
 #endif
 /* ANDROID CHANGES END */
 
@@ -5640,6 +5670,9 @@ printOptions:
 #ifdef ANDROID
 			ERROR("-android-fs-config\tuse android fs config "
 				"for mode, uid, and gids of inodes\n");
+			ERROR("-mount-point <name>\tNeed to be provided when "
+				"android-fs-config or context-file\n\t\t\tare "
+				"enabled and source directory is not mount point\n");
 #endif
 /* ANDROID CHANGES END */
 			ERROR("\nFilesystem filter options:\n");
diff --git a/squashfs-tools/xattr.c b/squashfs-tools/xattr.c
index bef7115..a405234 100644
--- a/squashfs-tools/xattr.c
+++ b/squashfs-tools/xattr.c
@@ -85,6 +85,7 @@ extern int fd;
 extern unsigned int xattr_bytes, total_xattr_bytes;
 /* ANDROID CHANGES START*/
 extern char *context_file;
+extern char *mount_point;
 /* ANDROID CHANGES END */
 
 /* helper functions from mksquashfs.c */
@@ -93,6 +94,11 @@ extern void write_destination(int, long long, int, void *);
 extern long long generic_write_table(int, void *, int, void *, int);
 extern int mangle(char *, char *, int, int, int, int);
 extern char *pathname(struct dir_ent *);
+/* ANDROID CHANGES START*/
+#ifdef ANDROID
+extern char *subpathname(struct dir_ent *);
+#endif
+/* ANDROID CHANGES END */
 
 /* helper functions and definitions from read_xattrs.c */
 extern int read_xattrs_from_disk(int, struct squashfs_super_block *);
@@ -650,8 +656,16 @@ int read_xattrs(void *d)
 	if (context_file) {
 		if (sehnd == NULL)
 			sehnd = get_sehnd(context_file);
-		xattrs = read_xattrs_from_context_file(filename, inode->buf.st_mode,
-				sehnd, &xattr_list);
+		if (mount_point) {
+			char *mounted_path;
+			alloc_mounted_path(mount_point, subpathname(dir_ent), &mounted_path);
+			xattrs = read_xattrs_from_context_file(mounted_path, inode->buf.st_mode,
+					sehnd, &xattr_list);
+			free(mounted_path);
+		} else {
+			xattrs = read_xattrs_from_context_file(filename, inode->buf.st_mode,
+					sehnd, &xattr_list);
+		}
 	} else {
 		xattrs = read_xattrs_from_system(filename, &xattr_list);
 	}