diff options
| -rw-r--r-- | mkfs.ubifs/mkfs.ubifs.c | 116 |
1 files changed, 37 insertions, 79 deletions
diff --git a/mkfs.ubifs/mkfs.ubifs.c b/mkfs.ubifs/mkfs.ubifs.c index 46f12ad..5b433bd 100644 --- a/mkfs.ubifs/mkfs.ubifs.c +++ b/mkfs.ubifs/mkfs.ubifs.c @@ -20,6 +20,7 @@ * Zoltan Sogor */ +#define _XOPEN_SOURCE 500 /* For realpath() */ #define PROGRAM_NAME "mkfs.ubifs" #include "mkfs.ubifs.h" @@ -235,93 +236,50 @@ static char *make_path(const char *dir, const char *name) } /** - * same_dir - determine if two file descriptors refer to the same directory. - * @fd1: file descriptor 1 - * @fd2: file descriptor 2 - */ -static int same_dir(int fd1, int fd2) -{ - struct stat stat1, stat2; - - if (fstat(fd1, &stat1) == -1) - return -1; - if (fstat(fd2, &stat2) == -1) - return -1; - return stat1.st_dev == stat2.st_dev && stat1.st_ino == stat2.st_ino; -} - -/** - * do_openat - open a file in a directory. - * @fd: file descriptor of open directory - * @path: path relative to directory - * @flags: open flags + * is_contained - determine if a file is beneath a directory. + * @file: file path name + * @dir: directory path name * - * This function is provided because the library function openat is sometimes - * not available. + * This function returns %1 if @file is accessible from the @dir directory and + * %0 otherwise. In case of error, returns %-1. */ -static int do_openat(int fd, const char *path, int flags) +static int is_contained(const char *file, const char *dir) { - int ret; - char *cwd; + char *file_base, *copy, *real_file, *real_dir, *p; - cwd = getcwd(NULL, 0); - if (!cwd) + /* Make a copy of the file path because 'dirname()' can modify it */ + copy = strdup(file); + if (!copy) return -1; - ret = fchdir(fd); - if (ret != -1) - ret = open(path, flags); - if (chdir(cwd) && !ret) - ret = -1; - free(cwd); - return ret; -} + file_base = dirname(copy); -/** - * in_path - determine if a file is beneath a directory. - * @dir_name: directory path name - * @file_name: file path name - */ -static int in_path(const char *dir_name, const char *file_name) -{ - char *fn = strdup(file_name); - char *dn; - int fd1, fd2, fd3, ret = -1, top_fd; + /* Turn the paths into the canonical form */ + real_file = malloc(PATH_MAX); + if (!real_file) { + free(copy); + return -1; + } - if (!fn) + real_dir = malloc(PATH_MAX); + if (!real_dir) { + free(real_file); + free(copy); + return -1; + } + if (!realpath(file_base, real_file)) { + perror("realpath"); return -1; - top_fd = open("/", O_RDONLY); - if (top_fd != -1) { - dn = dirname(fn); - fd1 = open(dir_name, O_RDONLY); - if (fd1 != -1) { - fd2 = open(dn, O_RDONLY); - if (fd2 != -1) { - while (1) { - int same; - - same = same_dir(fd1, fd2); - if (same) { - ret = same; - break; - } - if (same_dir(fd2, top_fd)) { - ret = 0; - break; - } - fd3 = do_openat(fd2, "..", O_RDONLY); - if (fd3 == -1) - break; - close(fd2); - fd2 = fd3; - } - close(fd2); - } - close(fd1); - } - close(top_fd); } - free(fn); - return ret; + if (!realpath(dir, real_dir)) { + perror("realpath"); + return -1; + } + + p = strstr(real_file, real_dir); + free(real_dir); + free(real_file); + free(copy); + return !!p; } /** @@ -376,7 +334,7 @@ static int validate_options(void) if (!output) return err_msg("no output file or UBI volume specified"); - if (root && in_path(root, output)) + if (root && is_contained(output, root)) return err_msg("output file cannot be in the UBIFS root " "directory"); if (!is_power_of_2(c->min_io_size)) |