From 62570f6f03fd6defb0d053e3650457553e42085a Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 22 Mar 2018 19:54:24 +0100 Subject: [PATCH] fs-util: add new CHASE_TRAIL_SLASH flag for chase_symlinks() This rearranges chase_symlinks() a bit: if no special flags are specified it will now revert to behaviour before b12d25a8d631af00b200e7aa9dbba6ba4a4a59ff. However, if the new CHASE_TRAIL_SLASH flag is specified it will follow the behaviour introduced by that commit. I wasn't sure which one to make the beaviour that requires specification of a flag to enable. I opted to make the "append trailing slash" behaviour the one to enable by a flag, following the thinking that the function should primarily be used to generate a normalized path, and I am pretty sure a path without trailing slash is the more "normalized" one, as the trailing slash is not really a part of it, but merely a "decorator" that tells various system calls to generate ENOTDIR if the path doesn't refer to a path. Or to say this differently: if the slash was part of normalization then we really should add it in all cases when the final path is a directory, not just when the user originally specified it. Fixes: #8544 Replaces: #8545 --- src/basic/fs-util.c | 6 ++++-- src/basic/fs-util.h | 1 + src/basic/mount-util.c | 2 +- src/core/dbus-manager.c | 2 +- src/core/namespace.c | 2 +- src/delta/delta.c | 4 ++-- src/journal/journalctl.c | 2 +- src/machine/machine-dbus.c | 2 +- src/shared/dissect-image.c | 2 +- src/shared/machine-image.c | 10 +++++----- 10 files changed, 18 insertions(+), 15 deletions(-) diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c index c65ba4bfe5..fc8f87da5f 100644 --- a/src/basic/fs-util.c +++ b/src/basic/fs-util.c @@ -685,8 +685,10 @@ int chase_symlinks(const char *path, const char *original_root, unsigned flags, /* Just a single slash? Then we reached the end. */ if (path_equal(first, "/")) { /* Preserve the trailing slash */ - if (!strextend(&done, "/", NULL)) - return -ENOMEM; + + if (flags & CHASE_TRAIL_SLASH) + if (!strextend(&done, "/", NULL)) + return -ENOMEM; break; } diff --git a/src/basic/fs-util.h b/src/basic/fs-util.h index 82d7e765b3..5298a41f0e 100644 --- a/src/basic/fs-util.h +++ b/src/basic/fs-util.h @@ -86,6 +86,7 @@ enum { CHASE_NO_AUTOFS = 1U << 2, /* If set, return -EREMOTE if autofs mount point found */ CHASE_SAFE = 1U << 3, /* If set, return EPERM if we ever traverse from unprivileged to privileged files or directories */ CHASE_OPEN = 1U << 4, /* If set, return an O_PATH object to the final component */ + CHASE_TRAIL_SLASH = 1U << 5, /* If set, any trailing slash will be preserved */ }; int chase_symlinks(const char *path_with_prefix, const char *root, unsigned flags, char **ret); diff --git a/src/basic/mount-util.c b/src/basic/mount-util.c index 8151b3a4e4..9672a7cf96 100644 --- a/src/basic/mount-util.c +++ b/src/basic/mount-util.c @@ -296,7 +296,7 @@ int path_is_mount_point(const char *t, const char *root, int flags) { * /bin -> /usr/bin/ and /usr is a mount point, then the parent that we * look at needs to be /usr, not /. */ if (flags & AT_SYMLINK_FOLLOW) { - r = chase_symlinks(t, root, 0, &canonical); + r = chase_symlinks(t, root, CHASE_TRAIL_SLASH, &canonical); if (r < 0) return r; diff --git a/src/core/dbus-manager.c b/src/core/dbus-manager.c index 90e7f86389..9136dcf17c 100644 --- a/src/core/dbus-manager.c +++ b/src/core/dbus-manager.c @@ -1583,7 +1583,7 @@ static int method_switch_root(sd_bus_message *message, void *userdata, sd_bus_er if (!path_is_absolute(init)) return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Path to init binary '%s' not absolute.", init); - r = chase_symlinks(init, root, CHASE_PREFIX_ROOT, &chased); + r = chase_symlinks(init, root, CHASE_PREFIX_ROOT|CHASE_TRAIL_SLASH, &chased); if (r < 0) return sd_bus_error_set_errnof(error, r, "Could not resolve init executable %s: %m", init); diff --git a/src/core/namespace.c b/src/core/namespace.c index 0e9c7b8fb4..a11c8e0147 100644 --- a/src/core/namespace.c +++ b/src/core/namespace.c @@ -824,7 +824,7 @@ static int mount_entry_chase( * chase the symlinks on our own first. This is called for the destination path, as well as the source path (if * that applies). The result is stored in "location". */ - r = chase_symlinks(path, root_directory, chase_nonexistent ? CHASE_NONEXISTENT : 0, &chased); + r = chase_symlinks(path, root_directory, CHASE_TRAIL_SLASH | (chase_nonexistent ? CHASE_NONEXISTENT : 0), &chased); if (r == -ENOENT && m->ignore) { log_debug_errno(r, "Path %s does not exist, ignoring.", path); return 0; diff --git a/src/delta/delta.c b/src/delta/delta.c index 49d9f0bb03..dc064b4c07 100644 --- a/src/delta/delta.c +++ b/src/delta/delta.c @@ -90,11 +90,11 @@ static int equivalent(const char *a, const char *b) { _cleanup_free_ char *x = NULL, *y = NULL; int r; - r = chase_symlinks(a, NULL, 0, &x); + r = chase_symlinks(a, NULL, CHASE_TRAIL_SLASH, &x); if (r < 0) return r; - r = chase_symlinks(b, NULL, 0, &y); + r = chase_symlinks(b, NULL, CHASE_TRAIL_SLASH, &y); if (r < 0) return r; diff --git a/src/journal/journalctl.c b/src/journal/journalctl.c index e8eb9ac161..fa2127c2b6 100644 --- a/src/journal/journalctl.c +++ b/src/journal/journalctl.c @@ -1070,7 +1070,7 @@ static int add_matches(sd_journal *j, char **args) { _cleanup_free_ char *p = NULL, *t = NULL, *t2 = NULL, *interpreter = NULL; struct stat st; - r = chase_symlinks(*i, NULL, 0, &p); + r = chase_symlinks(*i, NULL, CHASE_TRAIL_SLASH, &p); if (r < 0) return log_error_errno(r, "Couldn't canonicalize path: %m"); diff --git a/src/machine/machine-dbus.c b/src/machine/machine-dbus.c index 9c435d6715..37e16bbe79 100644 --- a/src/machine/machine-dbus.c +++ b/src/machine/machine-dbus.c @@ -907,7 +907,7 @@ int bus_machine_method_bind_mount(sd_bus_message *message, void *userdata, sd_bu if (laccess(p, F_OK) < 0) return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Container does not allow propagation of mount points."); - r = chase_symlinks(src, NULL, 0, &chased_src); + r = chase_symlinks(src, NULL, CHASE_TRAIL_SLASH, &chased_src); if (r < 0) return sd_bus_error_set_errnof(error, r, "Failed to resolve source path: %m"); diff --git a/src/shared/dissect-image.c b/src/shared/dissect-image.c index faeaddc66e..7af59422b2 100644 --- a/src/shared/dissect-image.c +++ b/src/shared/dissect-image.c @@ -1288,7 +1288,7 @@ int dissected_image_acquire_metadata(DissectedImage *m) { NULSTR_FOREACH(p, paths[k]) { _cleanup_free_ char *q = NULL; - r = chase_symlinks(p, t, CHASE_PREFIX_ROOT, &q); + r = chase_symlinks(p, t, CHASE_PREFIX_ROOT|CHASE_TRAIL_SLASH, &q); if (r < 0) continue; diff --git a/src/shared/machine-image.c b/src/shared/machine-image.c index 66eefb3036..12528ed015 100644 --- a/src/shared/machine-image.c +++ b/src/shared/machine-image.c @@ -938,7 +938,7 @@ int image_read_metadata(Image *i) { _cleanup_free_ char *hostname = NULL; _cleanup_free_ char *path = NULL; - r = chase_symlinks("/etc/hostname", i->path, CHASE_PREFIX_ROOT, &path); + r = chase_symlinks("/etc/hostname", i->path, CHASE_PREFIX_ROOT|CHASE_TRAIL_SLASH, &path); if (r < 0 && r != -ENOENT) log_debug_errno(r, "Failed to chase /etc/hostname in image %s: %m", i->name); else if (r >= 0) { @@ -949,7 +949,7 @@ int image_read_metadata(Image *i) { path = mfree(path); - r = chase_symlinks("/etc/machine-id", i->path, CHASE_PREFIX_ROOT, &path); + r = chase_symlinks("/etc/machine-id", i->path, CHASE_PREFIX_ROOT|CHASE_TRAIL_SLASH, &path); if (r < 0 && r != -ENOENT) log_debug_errno(r, "Failed to chase /etc/machine-id in image %s: %m", i->name); else if (r >= 0) { @@ -967,7 +967,7 @@ int image_read_metadata(Image *i) { path = mfree(path); - r = chase_symlinks("/etc/machine-info", i->path, CHASE_PREFIX_ROOT, &path); + r = chase_symlinks("/etc/machine-info", i->path, CHASE_PREFIX_ROOT|CHASE_TRAIL_SLASH, &path); if (r < 0 && r != -ENOENT) log_debug_errno(r, "Failed to chase /etc/machine-info in image %s: %m", i->name); else if (r >= 0) { @@ -978,9 +978,9 @@ int image_read_metadata(Image *i) { path = mfree(path); - r = chase_symlinks("/etc/os-release", i->path, CHASE_PREFIX_ROOT, &path); + r = chase_symlinks("/etc/os-release", i->path, CHASE_PREFIX_ROOT|CHASE_TRAIL_SLASH, &path); if (r == -ENOENT) - r = chase_symlinks("/usr/lib/os-release", i->path, CHASE_PREFIX_ROOT, &path); + r = chase_symlinks("/usr/lib/os-release", i->path, CHASE_PREFIX_ROOT|CHASE_TRAIL_SLASH, &path); if (r < 0 && r != -ENOENT) log_debug_errno(r, "Failed to chase os-release in image: %m"); else if (r >= 0) {