diff options
Diffstat (limited to '')
| -rw-r--r-- | debian/patches/machine-basic-factor-out-helper-function-to-add-airlocked.patch | 499 |
1 files changed, 499 insertions, 0 deletions
diff --git a/debian/patches/machine-basic-factor-out-helper-function-to-add-airlocked.patch b/debian/patches/machine-basic-factor-out-helper-function-to-add-airlocked.patch new file mode 100644 index 0000000..965e925 --- /dev/null +++ b/debian/patches/machine-basic-factor-out-helper-function-to-add-airlocked.patch @@ -0,0 +1,499 @@ +From: Luca Boccassi <luca.boccassi@microsoft.com> +Date: Thu, 13 Aug 2020 14:01:34 +0100 +Subject: machine/basic: factor out helper function to add airlocked mount to + namespace + +(cherry picked from commit 6af52c3a458691b016bedeba34c1e72294a67c81) +--- + src/machine/machine-dbus.c | 214 ++------------------------------------------ + src/shared/mount-util.c | 217 +++++++++++++++++++++++++++++++++++++++++++++ + src/shared/mount-util.h | 2 + + 3 files changed, 227 insertions(+), 206 deletions(-) + +diff --git a/src/machine/machine-dbus.c b/src/machine/machine-dbus.c +index 1105008..3c8f4fd 100644 +--- a/src/machine/machine-dbus.c ++++ b/src/machine/machine-dbus.c +@@ -810,17 +810,9 @@ int bus_machine_method_open_shell(sd_bus_message *message, void *userdata, sd_bu + } + + int bus_machine_method_bind_mount(sd_bus_message *message, void *userdata, sd_bus_error *error) { +- _cleanup_close_pair_ int errno_pipe_fd[2] = { -1, -1 }; +- char mount_slave[] = "/tmp/propagate.XXXXXX", *mount_tmp, *mount_outside, *p; +- bool mount_slave_created = false, mount_slave_mounted = false, +- mount_tmp_created = false, mount_tmp_mounted = false, +- mount_outside_created = false, mount_outside_mounted = false; +- _cleanup_free_ char *chased_src = NULL; + int read_only, make_file_or_directory; +- const char *dest, *src; ++ const char *dest, *src, *propagate_directory; + Machine *m = userdata; +- struct stat st; +- pid_t child; + uid_t uid; + int r; + +@@ -862,205 +854,15 @@ int bus_machine_method_bind_mount(sd_bus_message *message, void *userdata, sd_bu + if (uid != 0) + return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Can't bind mount on container with user namespacing applied."); + +- /* One day, when bind mounting /proc/self/fd/n works across +- * namespace boundaries we should rework this logic to make +- * use of it... */ +- +- p = strjoina("/run/systemd/nspawn/propagate/", m->name, "/"); +- 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, CHASE_TRAIL_SLASH, &chased_src, NULL); ++ propagate_directory = strjoina("/run/systemd/nspawn/propagate/", m->name); ++ r = bind_mount_in_namespace(m->leader, ++ propagate_directory, ++ "/run/host/incoming/", ++ src, dest, read_only, make_file_or_directory); + if (r < 0) +- return sd_bus_error_set_errnof(error, r, "Failed to resolve source path: %m"); +- +- if (lstat(chased_src, &st) < 0) +- return sd_bus_error_set_errnof(error, errno, "Failed to stat() source path: %m"); +- if (S_ISLNK(st.st_mode)) /* This shouldn't really happen, given that we just chased the symlinks above, but let's better be safe… */ +- return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Source directory can't be a symbolic link"); +- +- /* Our goal is to install a new bind mount into the container, +- possibly read-only. This is irritatingly complex +- unfortunately, currently. +- +- First, we start by creating a private playground in /tmp, +- that we can mount MS_SLAVE. (Which is necessary, since +- MS_MOVE cannot be applied to mounts with MS_SHARED parent +- mounts.) */ +- +- if (!mkdtemp(mount_slave)) +- return sd_bus_error_set_errnof(error, errno, "Failed to create playground %s: %m", mount_slave); +- +- mount_slave_created = true; +- +- r = mount_nofollow_verbose(LOG_DEBUG, mount_slave, mount_slave, NULL, MS_BIND, NULL); +- if (r < 0) { +- sd_bus_error_set_errnof(error, r, "Failed to make bind mount %s: %m", mount_slave); +- goto finish; +- } +- +- mount_slave_mounted = true; +- +- r = mount_nofollow_verbose(LOG_DEBUG, NULL, mount_slave, NULL, MS_SLAVE, NULL); +- if (r < 0) { +- sd_bus_error_set_errnof(error, r, "Failed to remount slave %s: %m", mount_slave); +- goto finish; +- } +- +- /* Second, we mount the source file or directory to a directory inside of our MS_SLAVE playground. */ +- mount_tmp = strjoina(mount_slave, "/mount"); +- r = make_mount_point_inode_from_stat(&st, mount_tmp, 0700); +- if (r < 0) { +- sd_bus_error_set_errnof(error, r, "Failed to create temporary mount point %s: %m", mount_tmp); +- goto finish; +- } +- +- mount_tmp_created = true; +- +- r = mount_nofollow_verbose(LOG_DEBUG, chased_src, mount_tmp, NULL, MS_BIND, NULL); +- if (r < 0) { +- sd_bus_error_set_errnof(error, r, "Failed to mount %s: %m", chased_src); +- goto finish; +- } +- +- mount_tmp_mounted = true; +- +- /* Third, we remount the new bind mount read-only if requested. */ +- if (read_only) { +- r = mount_nofollow_verbose(LOG_DEBUG, NULL, mount_tmp, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL); +- if (r < 0) { +- sd_bus_error_set_errnof(error, r, "Failed to remount read-only %s: %m", mount_tmp); +- goto finish; +- } +- } +- +- /* Fourth, we move the new bind mount into the propagation directory. This way it will appear there read-only +- * right-away. */ +- +- mount_outside = strjoina("/run/systemd/nspawn/propagate/", m->name, "/XXXXXX"); +- if (S_ISDIR(st.st_mode)) +- r = mkdtemp(mount_outside) ? 0 : -errno; +- else { +- r = mkostemp_safe(mount_outside); +- safe_close(r); +- } +- if (r < 0) { +- sd_bus_error_set_errnof(error, r, "Cannot create propagation file or directory %s: %m", mount_outside); +- goto finish; +- } +- +- mount_outside_created = true; +- +- r = mount_nofollow_verbose(LOG_DEBUG, mount_tmp, mount_outside, NULL, MS_MOVE, NULL); +- if (r < 0) { +- sd_bus_error_set_errnof(error, r, "Failed to move %s to %s: %m", mount_tmp, mount_outside); +- goto finish; +- } +- +- mount_outside_mounted = true; +- mount_tmp_mounted = false; +- +- if (S_ISDIR(st.st_mode)) +- (void) rmdir(mount_tmp); +- else +- (void) unlink(mount_tmp); +- mount_tmp_created = false; +- +- (void) umount_verbose(LOG_DEBUG, mount_slave, UMOUNT_NOFOLLOW); +- mount_slave_mounted = false; +- +- (void) rmdir(mount_slave); +- mount_slave_created = false; +- +- if (pipe2(errno_pipe_fd, O_CLOEXEC|O_NONBLOCK) < 0) { +- r = sd_bus_error_set_errnof(error, errno, "Failed to create pipe: %m"); +- goto finish; +- } +- +- r = safe_fork("(sd-bindmnt)", FORK_RESET_SIGNALS, &child); +- if (r < 0) { +- sd_bus_error_set_errnof(error, r, "Failed to fork(): %m"); +- goto finish; +- } +- if (r == 0) { +- const char *mount_inside, *q; +- int mntfd; +- +- errno_pipe_fd[0] = safe_close(errno_pipe_fd[0]); +- +- q = procfs_file_alloca(m->leader, "ns/mnt"); +- mntfd = open(q, O_RDONLY|O_NOCTTY|O_CLOEXEC); +- if (mntfd < 0) { +- r = log_error_errno(errno, "Failed to open mount namespace of leader: %m"); +- goto child_fail; +- } +- +- if (setns(mntfd, CLONE_NEWNS) < 0) { +- r = log_error_errno(errno, "Failed to join namespace of leader: %m"); +- goto child_fail; +- } +- +- if (make_file_or_directory) { +- (void) mkdir_parents(dest, 0755); +- (void) make_mount_point_inode_from_stat(&st, dest, 0700); +- } +- +- mount_inside = strjoina("/run/host/incoming/", basename(mount_outside)); +- r = mount_nofollow_verbose(LOG_ERR, mount_inside, dest, NULL, MS_MOVE, NULL); +- if (r < 0) +- goto child_fail; +- +- _exit(EXIT_SUCCESS); +- +- child_fail: +- (void) write(errno_pipe_fd[1], &r, sizeof(r)); +- errno_pipe_fd[1] = safe_close(errno_pipe_fd[1]); +- +- _exit(EXIT_FAILURE); +- } +- +- errno_pipe_fd[1] = safe_close(errno_pipe_fd[1]); ++ return sd_bus_error_set_errnof(error, r, "Failed to mount %s on %s in machine's namespace: %m", src, dest); + +- r = wait_for_terminate_and_check("(sd-bindmnt)", child, 0); +- if (r < 0) { +- r = sd_bus_error_set_errnof(error, r, "Failed to wait for child: %m"); +- goto finish; +- } +- if (r != EXIT_SUCCESS) { +- if (read(errno_pipe_fd[0], &r, sizeof(r)) == sizeof(r)) +- r = sd_bus_error_set_errnof(error, r, "Failed to mount: %m"); +- else +- r = sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Child failed."); +- goto finish; +- } +- +- r = sd_bus_reply_method_return(message, NULL); +- +-finish: +- if (mount_outside_mounted) +- (void) umount_verbose(LOG_DEBUG, mount_outside, UMOUNT_NOFOLLOW); +- if (mount_outside_created) { +- if (S_ISDIR(st.st_mode)) +- (void) rmdir(mount_outside); +- else +- (void) unlink(mount_outside); +- } +- +- if (mount_tmp_mounted) +- (void) umount_verbose(LOG_DEBUG, mount_tmp, UMOUNT_NOFOLLOW); +- if (mount_tmp_created) { +- if (S_ISDIR(st.st_mode)) +- (void) rmdir(mount_tmp); +- else +- (void) unlink(mount_tmp); +- } +- +- if (mount_slave_mounted) +- (void) umount_verbose(LOG_DEBUG, mount_slave, UMOUNT_NOFOLLOW); +- if (mount_slave_created) +- (void) rmdir(mount_slave); +- +- return r; ++ return sd_bus_reply_method_return(message, NULL); + } + + int bus_machine_method_copy(sd_bus_message *message, void *userdata, sd_bus_error *error) { +diff --git a/src/shared/mount-util.c b/src/shared/mount-util.c +index b19b384..4cfbb55 100644 +--- a/src/shared/mount-util.c ++++ b/src/shared/mount-util.c +@@ -14,15 +14,18 @@ + #include "fs-util.h" + #include "hashmap.h" + #include "libmount-util.h" ++#include "mkdir.h" + #include "mount-util.h" + #include "mountpoint-util.h" + #include "parse-util.h" + #include "path-util.h" ++#include "process-util.h" + #include "set.h" + #include "stat-util.h" + #include "stdio-util.h" + #include "string-util.h" + #include "strv.h" ++#include "tmpfile-util.h" + + int mount_fd(const char *source, + int target_fd, +@@ -742,3 +745,217 @@ int mount_option_mangle( + + return 0; + } ++ ++int bind_mount_in_namespace( ++ pid_t target, ++ const char *propagate_path, ++ const char *incoming_path, ++ const char *src, ++ const char *dest, ++ bool read_only, ++ bool make_file_or_directory) { ++ ++ _cleanup_close_pair_ int errno_pipe_fd[2] = { -1, -1 }; ++ char mount_slave[] = "/tmp/propagate.XXXXXX", *mount_tmp, *mount_outside, *p; ++ bool mount_slave_created = false, mount_slave_mounted = false, ++ mount_tmp_created = false, mount_tmp_mounted = false, ++ mount_outside_created = false, mount_outside_mounted = false; ++ _cleanup_free_ char *chased_src = NULL; ++ struct stat st; ++ pid_t child; ++ int r; ++ ++ assert(target > 0); ++ assert(propagate_path); ++ assert(incoming_path); ++ assert(src); ++ assert(dest); ++ ++ /* One day, when bind mounting /proc/self/fd/n works across ++ * namespace boundaries we should rework this logic to make ++ * use of it... */ ++ ++ p = strjoina(propagate_path, "/"); ++ r = laccess(p, F_OK); ++ if (r < 0) ++ return log_debug_errno(r == -ENOENT ? SYNTHETIC_ERRNO(EOPNOTSUPP) : r, "Target does not allow propagation of mount points"); ++ ++ r = chase_symlinks(src, NULL, CHASE_TRAIL_SLASH, &chased_src, NULL); ++ if (r < 0) ++ return log_debug_errno(r, "Failed to resolve source path of %s: %m", src); ++ ++ if (lstat(chased_src, &st) < 0) ++ return log_debug_errno(errno, "Failed to stat() resolved source path %s: %m", chased_src); ++ if (S_ISLNK(st.st_mode)) /* This shouldn't really happen, given that we just chased the symlinks above, but let's better be safe… */ ++ return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Source directory %s can't be a symbolic link", chased_src); ++ ++ /* Our goal is to install a new bind mount into the container, ++ possibly read-only. This is irritatingly complex ++ unfortunately, currently. ++ ++ First, we start by creating a private playground in /tmp, ++ that we can mount MS_SLAVE. (Which is necessary, since ++ MS_MOVE cannot be applied to mounts with MS_SHARED parent ++ mounts.) */ ++ ++ if (!mkdtemp(mount_slave)) ++ return log_debug_errno(errno, "Failed to create playground %s: %m", mount_slave); ++ ++ mount_slave_created = true; ++ ++ r = mount_nofollow_verbose(LOG_DEBUG, mount_slave, mount_slave, NULL, MS_BIND, NULL); ++ if (r < 0) ++ goto finish; ++ ++ mount_slave_mounted = true; ++ ++ r = mount_nofollow_verbose(LOG_DEBUG, NULL, mount_slave, NULL, MS_SLAVE, NULL); ++ if (r < 0) ++ goto finish; ++ ++ /* Second, we mount the source file or directory to a directory inside of our MS_SLAVE playground. */ ++ mount_tmp = strjoina(mount_slave, "/mount"); ++ r = make_mount_point_inode_from_stat(&st, mount_tmp, 0700); ++ if (r < 0) { ++ log_debug_errno(r, "Failed to create temporary mount point %s: %m", mount_tmp); ++ goto finish; ++ } ++ ++ mount_tmp_created = true; ++ ++ r = mount_nofollow_verbose(LOG_DEBUG, chased_src, mount_tmp, NULL, MS_BIND, NULL); ++ if (r < 0) ++ goto finish; ++ ++ mount_tmp_mounted = true; ++ ++ /* Third, we remount the new bind mount read-only if requested. */ ++ if (read_only) { ++ r = mount_nofollow_verbose(LOG_DEBUG, NULL, mount_tmp, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL); ++ if (r < 0) ++ goto finish; ++ } ++ ++ /* Fourth, we move the new bind mount into the propagation directory. This way it will appear there read-only ++ * right-away. */ ++ ++ mount_outside = strjoina(propagate_path, "/XXXXXX"); ++ if (S_ISDIR(st.st_mode)) ++ r = mkdtemp(mount_outside) ? 0 : -errno; ++ else { ++ r = mkostemp_safe(mount_outside); ++ safe_close(r); ++ } ++ if (r < 0) { ++ log_debug_errno(r, "Cannot create propagation file or directory %s: %m", mount_outside); ++ goto finish; ++ } ++ ++ mount_outside_created = true; ++ ++ r = mount_nofollow_verbose(LOG_DEBUG, mount_tmp, mount_outside, NULL, MS_MOVE, NULL); ++ if (r < 0) ++ goto finish; ++ ++ mount_outside_mounted = true; ++ mount_tmp_mounted = false; ++ ++ if (S_ISDIR(st.st_mode)) ++ (void) rmdir(mount_tmp); ++ else ++ (void) unlink(mount_tmp); ++ mount_tmp_created = false; ++ ++ (void) umount_verbose(LOG_DEBUG, mount_slave, UMOUNT_NOFOLLOW); ++ mount_slave_mounted = false; ++ ++ (void) rmdir(mount_slave); ++ mount_slave_created = false; ++ ++ if (pipe2(errno_pipe_fd, O_CLOEXEC|O_NONBLOCK) < 0) { ++ log_debug_errno(errno, "Failed to create pipe: %m"); ++ goto finish; ++ } ++ ++ r = safe_fork("(sd-bindmnt)", FORK_RESET_SIGNALS, &child); ++ if (r < 0) ++ goto finish; ++ if (r == 0) { ++ const char *mount_inside, *q; ++ int mntfd; ++ ++ errno_pipe_fd[0] = safe_close(errno_pipe_fd[0]); ++ ++ q = procfs_file_alloca(target, "ns/mnt"); ++ mntfd = open(q, O_RDONLY|O_NOCTTY|O_CLOEXEC); ++ if (mntfd < 0) { ++ r = log_error_errno(errno, "Failed to open mount namespace of leader: %m"); ++ goto child_fail; ++ } ++ ++ if (setns(mntfd, CLONE_NEWNS) < 0) { ++ r = log_error_errno(errno, "Failed to join namespace of leader: %m"); ++ goto child_fail; ++ } ++ ++ if (make_file_or_directory) { ++ (void) mkdir_parents(dest, 0755); ++ (void) make_mount_point_inode_from_stat(&st, dest, 0700); ++ } ++ ++ /* Fifth, move the mount to the right place inside */ ++ mount_inside = strjoina(incoming_path, basename(mount_outside)); ++ r = mount_nofollow_verbose(LOG_ERR, mount_inside, dest, NULL, MS_MOVE, NULL); ++ if (r < 0) ++ goto child_fail; ++ ++ _exit(EXIT_SUCCESS); ++ ++ child_fail: ++ (void) write(errno_pipe_fd[1], &r, sizeof(r)); ++ errno_pipe_fd[1] = safe_close(errno_pipe_fd[1]); ++ ++ _exit(EXIT_FAILURE); ++ } ++ ++ errno_pipe_fd[1] = safe_close(errno_pipe_fd[1]); ++ ++ r = wait_for_terminate_and_check("(sd-bindmnt)", child, 0); ++ if (r < 0) { ++ log_debug_errno(r, "Failed to wait for child: %m"); ++ goto finish; ++ } ++ if (r != EXIT_SUCCESS) { ++ if (read(errno_pipe_fd[0], &r, sizeof(r)) == sizeof(r)) ++ log_debug_errno(r, "Failed to mount: %m"); ++ else ++ log_debug("Child failed."); ++ goto finish; ++ } ++ ++finish: ++ if (mount_outside_mounted) ++ (void) umount_verbose(LOG_DEBUG, mount_outside, UMOUNT_NOFOLLOW); ++ if (mount_outside_created) { ++ if (S_ISDIR(st.st_mode)) ++ (void) rmdir(mount_outside); ++ else ++ (void) unlink(mount_outside); ++ } ++ ++ if (mount_tmp_mounted) ++ (void) umount_verbose(LOG_DEBUG, mount_tmp, UMOUNT_NOFOLLOW); ++ if (mount_tmp_created) { ++ if (S_ISDIR(st.st_mode)) ++ (void) rmdir(mount_tmp); ++ else ++ (void) unlink(mount_tmp); ++ } ++ ++ if (mount_slave_mounted) ++ (void) umount_verbose(LOG_DEBUG, mount_slave, UMOUNT_NOFOLLOW); ++ if (mount_slave_created) ++ (void) rmdir(mount_slave); ++ ++ return r; ++} +diff --git a/src/shared/mount-util.h b/src/shared/mount-util.h +index 6202008..c3500a0 100644 +--- a/src/shared/mount-util.h ++++ b/src/shared/mount-util.h +@@ -97,3 +97,5 @@ static inline char* umount_and_rmdir_and_free(char *p) { + return NULL; + } + DEFINE_TRIVIAL_CLEANUP_FUNC(char*, umount_and_rmdir_and_free); ++ ++int bind_mount_in_namespace(pid_t target, const char *propagate_path, const char *incoming_path, const char *src, const char *dest, bool read_only, bool make_file_or_directory); |