diff options
Diffstat (limited to 'src/basic/fs-util.c')
| -rw-r--r-- | src/basic/fs-util.c | 77 |
1 files changed, 40 insertions, 37 deletions
diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c index a92241ca02..d20b9a5df5 100644 --- a/src/basic/fs-util.c +++ b/src/basic/fs-util.c @@ -713,7 +713,7 @@ static int log_autofs_mount_point(int fd, const char *path, unsigned flags) { n1, path); } -int chase_symlinks(const char *path, const char *original_root, unsigned flags, char **ret) { +int chase_symlinks(const char *path, const char *original_root, unsigned flags, char **ret_path, int *ret_fd) { _cleanup_free_ char *buffer = NULL, *done = NULL, *root = NULL; _cleanup_close_ int fd = -1; unsigned max_follow = CHASE_SYMLINKS_MAX; /* how many symlinks to follow before giving up and returning ELOOP */ @@ -725,10 +725,10 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags, assert(path); /* Either the file may be missing, or we return an fd to the final object, but both make no sense */ - if (FLAGS_SET(flags, CHASE_NONEXISTENT | CHASE_OPEN)) + if ((flags & CHASE_NONEXISTENT) && ret_fd) return -EINVAL; - if (FLAGS_SET(flags, CHASE_STEP | CHASE_OPEN)) + if ((flags & CHASE_STEP) && ret_fd) return -EINVAL; if (isempty(path)) @@ -754,17 +754,17 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags, * function what to do when encountering a symlink with an absolute path as directory: prefix it by the * specified path. * - * There are three ways to invoke this function: + * There are five ways to invoke this function: * - * 1. Without CHASE_STEP or CHASE_OPEN: in this case the path is resolved and the normalized path is returned - * in `ret`. The return value is < 0 on error. If CHASE_NONEXISTENT is also set, 0 is returned if the file - * doesn't exist, > 0 otherwise. If CHASE_NONEXISTENT is not set, >= 0 is returned if the destination was - * found, -ENOENT if it wasn't. + * 1. Without CHASE_STEP or ret_fd: in this case the path is resolved and the normalized path is + * returned in `ret_path`. The return value is < 0 on error. If CHASE_NONEXISTENT is also set, 0 + * is returned if the file doesn't exist, > 0 otherwise. If CHASE_NONEXISTENT is not set, >= 0 is + * returned if the destination was found, -ENOENT if it wasn't. * - * 2. With CHASE_OPEN: in this case the destination is opened after chasing it as O_PATH and this file + * 2. With ret_fd: in this case the destination is opened after chasing it as O_PATH and this file * descriptor is returned as return value. This is useful to open files relative to some root * directory. Note that the returned O_PATH file descriptors must be converted into a regular one (using - * fd_reopen() or such) before it can be used for reading/writing. CHASE_OPEN may not be combined with + * fd_reopen() or such) before it can be used for reading/writing. ret_fd may not be combined with * CHASE_NONEXISTENT. * * 3. With CHASE_STEP: in this case only a single step of the normalization is executed, i.e. only the first @@ -780,21 +780,21 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags, * 5. With CHASE_NO_AUTOFS: in this case if an autofs mount point is encountered, path normalization * is aborted and -EREMOTE is returned. If CHASE_WARN is also set, a warning showing the path of * the mount point is emitted. - * */ /* A root directory of "/" or "" is identical to none */ if (empty_or_root(original_root)) original_root = NULL; - if (!original_root && !ret && (flags & (CHASE_NONEXISTENT|CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_OPEN|CHASE_STEP)) == CHASE_OPEN) { - /* Shortcut the CHASE_OPEN case if the caller isn't interested in the actual path and has no root set + if (!original_root && !ret_path && !(flags & (CHASE_NONEXISTENT|CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_STEP)) && ret_fd) { + /* Shortcut the ret_fd case if the caller isn't interested in the actual path and has no root set * and doesn't care about any of the other special features we provide either. */ r = open(path, O_PATH|O_CLOEXEC|((flags & CHASE_NOFOLLOW) ? O_NOFOLLOW : 0)); if (r < 0) return -errno; - return r; + *ret_fd = r; + return 0; } if (original_root) { @@ -803,7 +803,6 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags, return r; if (flags & CHASE_PREFIX_ROOT) { - /* We don't support relative paths in combination with a root directory */ if (!path_is_absolute(path)) return -EINVAL; @@ -948,7 +947,6 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags, if (S_ISLNK(st.st_mode) && !((flags & CHASE_NOFOLLOW) && isempty(todo))) { char *joined; - _cleanup_free_ char *destination = NULL; /* This is a symlink, in this case read the destination. But let's make sure we don't follow @@ -1034,15 +1032,15 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags, return -ENOMEM; } - if (ret) - *ret = TAKE_PTR(done); + if (ret_path) + *ret_path = TAKE_PTR(done); - if (flags & CHASE_OPEN) { - /* Return the O_PATH fd we currently are looking to the caller. It can translate it to a proper fd by - * opening /proc/self/fd/xyz. */ + if (ret_fd) { + /* Return the O_PATH fd we currently are looking to the caller. It can translate it to a + * proper fd by opening /proc/self/fd/xyz. */ assert(fd >= 0); - return TAKE_FD(fd); + *ret_fd = TAKE_FD(fd); } if (flags & CHASE_STEP) @@ -1051,14 +1049,14 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags, return exists; chased_one: - if (ret) { + if (ret_path) { char *c; c = strjoin(strempty(done), todo); if (!c) return -ENOMEM; - *ret = c; + *ret_path = c; } return 0; @@ -1087,9 +1085,10 @@ int chase_symlinks_and_open( return r; } - path_fd = chase_symlinks(path, root, chase_flags|CHASE_OPEN, ret_path ? &p : NULL); - if (path_fd < 0) - return path_fd; + r = chase_symlinks(path, root, chase_flags, ret_path ? &p : NULL, &path_fd); + if (r < 0) + return r; + assert(path_fd >= 0); r = fd_reopen(path_fd, open_flags); if (r < 0) @@ -1112,6 +1111,7 @@ int chase_symlinks_and_opendir( _cleanup_close_ int path_fd = -1; _cleanup_free_ char *p = NULL; DIR *d; + int r; if (!ret_dir) return -EINVAL; @@ -1128,9 +1128,10 @@ int chase_symlinks_and_opendir( return 0; } - path_fd = chase_symlinks(path, root, chase_flags|CHASE_OPEN, ret_path ? &p : NULL); - if (path_fd < 0) - return path_fd; + r = chase_symlinks(path, root, chase_flags, ret_path ? &p : NULL, &path_fd); + if (r < 0) + return r; + assert(path_fd >= 0); xsprintf(procfs_path, "/proc/self/fd/%i", path_fd); d = opendir(procfs_path); @@ -1149,10 +1150,12 @@ int chase_symlinks_and_stat( const char *root, unsigned chase_flags, char **ret_path, - struct stat *ret_stat) { + struct stat *ret_stat, + int *ret_fd) { _cleanup_close_ int path_fd = -1; _cleanup_free_ char *p = NULL; + int r; assert(path); assert(ret_stat); @@ -1168,18 +1171,18 @@ int chase_symlinks_and_stat( return 1; } - path_fd = chase_symlinks(path, root, chase_flags|CHASE_OPEN, ret_path ? &p : NULL); - if (path_fd < 0) - return path_fd; + r = chase_symlinks(path, root, chase_flags, ret_path ? &p : NULL, &path_fd); + if (r < 0) + return r; + assert(path_fd >= 0); if (fstat(path_fd, ret_stat) < 0) return -errno; if (ret_path) *ret_path = TAKE_PTR(p); - - if (chase_flags & CHASE_OPEN) - return TAKE_FD(path_fd); + if (ret_fd) + *ret_fd = TAKE_FD(path_fd); return 1; } |