diff options
Diffstat (limited to 'pkg')
-rw-r--r-- | pkg/registries/registries.go | 6 | ||||
-rw-r--r-- | pkg/rootless/rootless_linux.c | 412 | ||||
-rw-r--r-- | pkg/rootless/rootless_linux.go | 57 | ||||
-rw-r--r-- | pkg/rootless/rootless_unsupported.go | 4 | ||||
-rw-r--r-- | pkg/spec/storage.go | 36 | ||||
-rw-r--r-- | pkg/util/utils_supported.go | 10 | ||||
-rw-r--r-- | pkg/util/utils_windows.go | 6 |
7 files changed, 460 insertions, 71 deletions
diff --git a/pkg/registries/registries.go b/pkg/registries/registries.go index fdb7f33c5..5c4ecd020 100644 --- a/pkg/registries/registries.go +++ b/pkg/registries/registries.go @@ -51,7 +51,7 @@ func GetRegistries() ([]string, error) { } for _, reg := range registries { if reg.Search { - searchRegistries = append(searchRegistries, reg.URL) + searchRegistries = append(searchRegistries, reg.Location) } } return searchRegistries, nil @@ -66,7 +66,7 @@ func GetBlockedRegistries() ([]string, error) { } for _, reg := range registries { if reg.Blocked { - blockedRegistries = append(blockedRegistries, reg.URL) + blockedRegistries = append(blockedRegistries, reg.Location) } } return blockedRegistries, nil @@ -81,7 +81,7 @@ func GetInsecureRegistries() ([]string, error) { } for _, reg := range registries { if reg.Insecure { - insecureRegistries = append(insecureRegistries, reg.URL) + insecureRegistries = append(insecureRegistries, reg.Location) } } return insecureRegistries, nil diff --git a/pkg/rootless/rootless_linux.c b/pkg/rootless/rootless_linux.c index 1d32b1adb..a08cfd36a 100644 --- a/pkg/rootless/rootless_linux.c +++ b/pkg/rootless/rootless_linux.c @@ -17,38 +17,29 @@ #include <sys/prctl.h> #include <dirent.h> #include <sys/select.h> +#include <stdio.h> + +#ifndef RENAME_NOREPLACE +# define RENAME_NOREPLACE (1 << 0) + +int renameat2 (int olddirfd, const char *oldpath, int newdirfd, const char *newpath, unsigned int flags) +{ +# ifdef __NR_renameat2 + return (int) syscall (__NR_renameat2, olddirfd, oldpath, newdirfd, newpath, flags); +# else + /* no way to implement it atomically. */ + errno = ENOSYS; + return -1; +# endif +} +#endif static const char *_max_user_namespaces = "/proc/sys/user/max_user_namespaces"; static const char *_unprivileged_user_namespaces = "/proc/sys/kernel/unprivileged_userns_clone"; static int open_files_max_fd; fd_set open_files_set; - -static void __attribute__((constructor)) init() -{ - DIR *d; - - /* Store how many FDs were open before the Go runtime kicked in. */ - d = opendir ("/proc/self/fd"); - if (d) - { - struct dirent *ent; - - FD_ZERO (&open_files_set); - for (ent = readdir (d); ent; ent = readdir (d)) - { - int fd = atoi (ent->d_name); - if (fd != dirfd (d)) - { - if (fd > open_files_max_fd) - open_files_max_fd = fd; - FD_SET (fd, &open_files_set); - } - } - closedir (d); - } -} - +static uid_t rootless_uid_init; static int syscall_setresuid (uid_t ruid, uid_t euid, uid_t suid) @@ -62,14 +53,18 @@ syscall_setresgid (gid_t rgid, gid_t egid, gid_t sgid) return (int) syscall (__NR_setresgid, rgid, egid, sgid); } -static int -syscall_clone (unsigned long flags, void *child_stack) +uid_t +rootless_uid () { -#if defined(__s390__) || defined(__CRIS__) - return (int) syscall (__NR_clone, child_stack, flags); -#else - return (int) syscall (__NR_clone, flags, child_stack); -#endif + return rootless_uid_init; +} + +static void +do_pause () +{ + prctl (PR_SET_NAME, "podman pause", NULL, NULL, NULL); + while (1) + pause (); } static char ** @@ -84,7 +79,10 @@ get_cmd_line_args (pid_t pid) int i, argc = 0; char **argv; - sprintf (path, "/proc/%d/cmdline", pid); + if (pid) + sprintf (path, "/proc/%d/cmdline", pid); + else + strcpy (path, "/proc/self/cmdline"); fd = open (path, O_RDONLY); if (fd < 0) return NULL; @@ -99,7 +97,10 @@ get_cmd_line_args (pid_t pid) ret = read (fd, buffer + used, allocated - used); while (ret < 0 && errno == EINTR); if (ret < 0) - return NULL; + { + free (buffer); + return NULL; + } if (ret == 0) break; @@ -109,11 +110,12 @@ get_cmd_line_args (pid_t pid) { allocated += 512; char *tmp = realloc (buffer, allocated); - if (buffer == NULL) { - free(buffer); - return NULL; - } - buffer=tmp; + if (buffer == NULL) + { + free (buffer); + return NULL; + } + buffer = tmp; } } close (fd); @@ -122,11 +124,17 @@ get_cmd_line_args (pid_t pid) if (buffer[i] == '\0') argc++; if (argc == 0) - return NULL; + { + free (buffer); + return NULL; + } argv = malloc (sizeof (char *) * (argc + 1)); if (argv == NULL) - return NULL; + { + free (buffer); + return NULL; + } argc = 0; argv[argc++] = buffer; @@ -139,8 +147,296 @@ get_cmd_line_args (pid_t pid) return argv; } +static bool +can_use_shortcut () +{ + int argc; + char **argv; + bool ret = true; + +#ifdef DISABLE_JOIN_SHORTCUT + return false; +#endif + + argv = get_cmd_line_args (0); + if (argv == NULL) + return NULL; + + for (argc = 0; argv[argc]; argc++) + { + if (argc == 0 || argv[argc][0] == '-') + continue; + + if (strcmp (argv[argc], "mount") == 0 + || strcmp (argv[argc], "search") == 0 + || strcmp (argv[argc], "system") == 0) + { + ret = false; + break; + } + } + + free (argv[0]); + free (argv); + return ret; +} + +static void __attribute__((constructor)) init() +{ + const char *xdg_runtime_dir; + const char *pause; + DIR *d; + + pause = getenv ("_PODMAN_PAUSE"); + if (pause && pause[0]) + { + do_pause (); + _exit (EXIT_FAILURE); + } + + /* Store how many FDs were open before the Go runtime kicked in. */ + d = opendir ("/proc/self/fd"); + if (d) + { + struct dirent *ent; + + FD_ZERO (&open_files_set); + for (ent = readdir (d); ent; ent = readdir (d)) + { + int fd = atoi (ent->d_name); + if (fd != dirfd (d)) + { + if (fd > open_files_max_fd) + open_files_max_fd = fd; + FD_SET (fd, &open_files_set); + } + } + closedir (d); + } + + /* Shortcut. If we are able to join the pause pid file, do it now so we don't + need to re-exec. */ + xdg_runtime_dir = getenv ("XDG_RUNTIME_DIR"); + if (xdg_runtime_dir && xdg_runtime_dir[0] && can_use_shortcut ()) + { + int r; + int fd; + long pid; + char buf[12]; + uid_t uid; + char path[PATH_MAX]; + const char *const suffix = "/libpod/pause.pid"; + char *cwd = getcwd (NULL, 0); + + if (cwd == NULL) + { + fprintf (stderr, "error getting current working directory: %s\n", strerror (errno)); + _exit (EXIT_FAILURE); + } + + if (strlen (xdg_runtime_dir) >= PATH_MAX - strlen (suffix)) + { + fprintf (stderr, "invalid value for XDG_RUNTIME_DIR: %s", strerror (ENAMETOOLONG)); + exit (EXIT_FAILURE); + } + + sprintf (path, "%s%s", xdg_runtime_dir, suffix); + fd = open (path, O_RDONLY); + if (fd < 0) + { + free (cwd); + return; + } + + r = read (fd, buf, sizeof (buf)); + close (fd); + if (r < 0) + { + free (cwd); + return; + } + pid = strtol (buf, NULL, 10); + if (pid == LONG_MAX) + { + free (cwd); + return; + } + + uid = geteuid (); + + sprintf (path, "/proc/%d/ns/user", pid); + fd = open (path, O_RDONLY); + if (fd < 0 || setns (fd, 0) < 0) + { + free (cwd); + return; + } + close (fd); + + /* Errors here cannot be ignored as we already joined a ns. */ + sprintf (path, "/proc/%d/ns/mnt", pid); + fd = open (path, O_RDONLY); + if (fd < 0) + { + fprintf (stderr, "cannot open %s: %s", path, strerror (errno)); + exit (EXIT_FAILURE); + } + + r = setns (fd, 0); + if (r < 0) + { + fprintf (stderr, "cannot join mount namespace for %d: %s", pid, strerror (errno)); + exit (EXIT_FAILURE); + } + close (fd); + + if (syscall_setresgid (0, 0, 0) < 0) + { + fprintf (stderr, "cannot setresgid: %s\n", strerror (errno)); + _exit (EXIT_FAILURE); + } + + if (syscall_setresuid (0, 0, 0) < 0) + { + fprintf (stderr, "cannot setresuid: %s\n", strerror (errno)); + _exit (EXIT_FAILURE); + } + + if (chdir (cwd) < 0) + { + fprintf (stderr, "cannot chdir: %s\n", strerror (errno)); + _exit (EXIT_FAILURE); + } + + free (cwd); + rootless_uid_init = uid; + } +} + +static int +syscall_clone (unsigned long flags, void *child_stack) +{ +#if defined(__s390__) || defined(__CRIS__) + return (int) syscall (__NR_clone, child_stack, flags); +#else + return (int) syscall (__NR_clone, flags, child_stack); +#endif +} + +static int +create_pause_process (const char *pause_pid_file_path, char **argv) +{ + int r, p[2]; + + if (pipe (p) < 0) + _exit (EXIT_FAILURE); + + r = fork (); + if (r < 0) + _exit (EXIT_FAILURE); + + if (r) + { + char b; + + close (p[1]); + /* Block until we write the pid file. */ + do + r = read (p[0], &b, 1); + while (r < 0 && errno == EINTR); + close (p[0]); + + return r == 1 && b == '0' ? 0 : -1; + } + else + { + int fd; + pid_t pid; + + close (p[0]); + + setsid (); + pid = fork (); + if (r < 0) + _exit (EXIT_FAILURE); + + if (pid) + { + char pid_str[12]; + char *tmp_file_path = NULL; + + sprintf (pid_str, "%d", pid); + + asprintf (&tmp_file_path, "%s.XXXXXX", pause_pid_file_path); + if (tmp_file_path == NULL) + { + kill (pid, SIGKILL); + _exit (EXIT_FAILURE); + } + + fd = mkstemp (tmp_file_path); + if (fd < 0) + { + kill (pid, SIGKILL); + _exit (EXIT_FAILURE); + } + + do + r = write (fd, pid_str, strlen (pid_str)); + while (r < 0 && errno == EINTR); + if (r < 0) + { + kill (pid, SIGKILL); + _exit (EXIT_FAILURE); + } + close (fd); + + /* There can be another process at this point trying to configure the user namespace and the pause + process, do not override the pid file if it already exists. */ + if (renameat2 (AT_FDCWD, tmp_file_path, AT_FDCWD, pause_pid_file_path, RENAME_NOREPLACE) < 0) + { + unlink (tmp_file_path); + kill (pid, SIGKILL); + _exit (EXIT_FAILURE); + } + + do + r = write (p[1], "0", 1); + while (r < 0 && errno == EINTR); + close (p[1]); + + _exit (EXIT_SUCCESS); + } + else + { + int null; + + close (p[1]); + + null = open ("/dev/null", O_RDWR); + if (null >= 0) + { + dup2 (null, 0); + dup2 (null, 1); + dup2 (null, 2); + close (null); + } + + for (fd = 3; fd < open_files_max_fd + 16; fd++) + close (fd); + + setenv ("_PODMAN_PAUSE", "1", 1); + execlp (argv[0], NULL); + + /* If the execve fails, then do the pause here. */ + do_pause (); + _exit (EXIT_FAILURE); + } + } +} + int -reexec_userns_join (int userns, int mountns) +reexec_userns_join (int userns, int mountns, char *pause_pid_file_path) { pid_t ppid = getpid (); char uid[16]; @@ -200,7 +496,7 @@ reexec_userns_join (int userns, int mountns) fprintf (stderr, "cannot setns: %s\n", strerror (errno)); _exit (EXIT_FAILURE); } - close (userns); + close (mountns); if (syscall_setresgid (0, 0, 0) < 0) { @@ -221,6 +517,12 @@ reexec_userns_join (int userns, int mountns) } free (cwd); + if (pause_pid_file_path && pause_pid_file_path[0] != '\0') + { + /* We ignore errors here as we didn't create the namespace anyway. */ + create_pause_process (pause_pid_file_path, argv); + } + execvp (argv[0], argv); _exit (EXIT_FAILURE); @@ -246,7 +548,7 @@ check_proc_sys_userns_file (const char *path) } int -reexec_in_user_namespace (int ready) +reexec_in_user_namespace (int ready, char *pause_pid_file_path) { int ret; pid_t pid; @@ -328,29 +630,45 @@ reexec_in_user_namespace (int ready) fprintf (stderr, "cannot read from sync pipe: %s\n", strerror (errno)); _exit (EXIT_FAILURE); } - close (ready); - if (b != '1') + if (b != '0') _exit (EXIT_FAILURE); if (syscall_setresgid (0, 0, 0) < 0) { fprintf (stderr, "cannot setresgid: %s\n", strerror (errno)); + write (ready, "1", 1); _exit (EXIT_FAILURE); } if (syscall_setresuid (0, 0, 0) < 0) { fprintf (stderr, "cannot setresuid: %s\n", strerror (errno)); + write (ready, "1", 1); _exit (EXIT_FAILURE); } if (chdir (cwd) < 0) { fprintf (stderr, "cannot chdir: %s\n", strerror (errno)); + write (ready, "1", 1); _exit (EXIT_FAILURE); } free (cwd); + if (pause_pid_file_path && pause_pid_file_path[0] != '\0') + { + if (create_pause_process (pause_pid_file_path, argv) < 0) + { + write (ready, "2", 1); + _exit (EXIT_FAILURE); + } + } + + do + ret = write (ready, "0", 1) < 0; + while (ret < 0 && errno == EINTR); + close (ready); + execvp (argv[0], argv); _exit (EXIT_FAILURE); diff --git a/pkg/rootless/rootless_linux.go b/pkg/rootless/rootless_linux.go index 2c99f41a4..ddf881368 100644 --- a/pkg/rootless/rootless_linux.go +++ b/pkg/rootless/rootless_linux.go @@ -22,9 +22,12 @@ import ( ) /* -extern int reexec_in_user_namespace(int ready); +#cgo remoteclient CFLAGS: -DDISABLE_JOIN_SHORTCUT +#include <stdlib.h> +extern uid_t rootless_uid(); +extern int reexec_in_user_namespace(int ready, char *pause_pid_file_path); extern int reexec_in_user_namespace_wait(int pid); -extern int reexec_userns_join(int userns, int mountns); +extern int reexec_userns_join(int userns, int mountns, char *pause_pid_file_path); */ import "C" @@ -45,6 +48,12 @@ var ( // IsRootless tells us if we are running in rootless mode func IsRootless() bool { isRootlessOnce.Do(func() { + rootlessUIDInit := int(C.rootless_uid()) + if rootlessUIDInit != 0 { + // This happens if we joined the user+mount namespace as part of + os.Setenv("_CONTAINERS_USERNS_CONFIGURED", "done") + os.Setenv("_CONTAINERS_ROOTLESS_UID", fmt.Sprintf("%d", rootlessUIDInit)) + } isRootless = os.Geteuid() != 0 || os.Getenv("_CONTAINERS_USERNS_CONFIGURED") != "" }) return isRootless @@ -168,11 +177,14 @@ func getUserNSFirstChild(fd uintptr) (*os.File, error) { // JoinUserAndMountNS re-exec podman in a new userNS and join the user and mount // namespace of the specified PID without looking up its parent. Useful to join directly // the conmon process. -func JoinUserAndMountNS(pid uint) (bool, int, error) { +func JoinUserAndMountNS(pid uint, pausePid string) (bool, int, error) { if os.Geteuid() == 0 || os.Getenv("_CONTAINERS_USERNS_CONFIGURED") != "" { return false, -1, nil } + cPausePid := C.CString(pausePid) + defer C.free(unsafe.Pointer(cPausePid)) + userNS, err := os.Open(fmt.Sprintf("/proc/%d/ns/user", pid)) if err != nil { return false, -1, err @@ -189,7 +201,7 @@ func JoinUserAndMountNS(pid uint) (bool, int, error) { if err != nil { return false, -1, err } - pidC := C.reexec_userns_join(C.int(fd.Fd()), C.int(mountNS.Fd())) + pidC := C.reexec_userns_join(C.int(fd.Fd()), C.int(mountNS.Fd()), cPausePid) if int(pidC) < 0 { return false, -1, errors.Errorf("cannot re-exec process") } @@ -206,7 +218,7 @@ func JoinUserAndMountNS(pid uint) (bool, int, error) { // into a new user namespace and the return code from the re-executed podman process. // If podman was re-executed the caller needs to propagate the error code returned by the child // process. -func BecomeRootInUserNS() (bool, int, error) { +func BecomeRootInUserNS(pausePid string) (bool, int, error) { if os.Geteuid() == 0 || os.Getenv("_CONTAINERS_USERNS_CONFIGURED") != "" { if os.Getenv("_CONTAINERS_USERNS_CONFIGURED") == "init" { return false, 0, runInUser() @@ -214,18 +226,23 @@ func BecomeRootInUserNS() (bool, int, error) { return false, 0, nil } + cPausePid := C.CString(pausePid) + defer C.free(unsafe.Pointer(cPausePid)) + runtime.LockOSThread() defer runtime.UnlockOSThread() - r, w, err := os.Pipe() + fds, err := syscall.Socketpair(syscall.AF_UNIX, syscall.SOCK_DGRAM, 0) if err != nil { return false, -1, err } + r, w := os.NewFile(uintptr(fds[0]), "sync host"), os.NewFile(uintptr(fds[1]), "sync child") + defer r.Close() defer w.Close() defer w.Write([]byte("0")) - pidC := C.reexec_in_user_namespace(C.int(r.Fd())) + pidC := C.reexec_in_user_namespace(C.int(r.Fd()), cPausePid) pid := int(pidC) if pid < 0 { return false, -1, errors.Errorf("cannot re-exec process") @@ -280,11 +297,35 @@ func BecomeRootInUserNS() (bool, int, error) { } } - _, err = w.Write([]byte("1")) + _, err = w.Write([]byte("0")) if err != nil { return false, -1, errors.Wrapf(err, "write to sync pipe") } + b := make([]byte, 1, 1) + _, err = w.Read(b) + if err != nil { + return false, -1, errors.Wrapf(err, "read from sync pipe") + } + + if b[0] == '2' { + // We have lost the race for writing the PID file, as probably another + // process created a namespace and wrote the PID. + // Try to join it. + data, err := ioutil.ReadFile(pausePid) + if err == nil { + pid, err := strconv.ParseUint(string(data), 10, 0) + if err == nil { + return JoinUserAndMountNS(uint(pid), "") + } + } + return false, -1, errors.Wrapf(err, "error setting up the process") + } + + if b[0] != '0' { + return false, -1, errors.Wrapf(err, "error setting up the process") + } + c := make(chan os.Signal, 1) signals := []os.Signal{} diff --git a/pkg/rootless/rootless_unsupported.go b/pkg/rootless/rootless_unsupported.go index 47b5dd7cc..42f8f3aec 100644 --- a/pkg/rootless/rootless_unsupported.go +++ b/pkg/rootless/rootless_unsupported.go @@ -15,7 +15,7 @@ func IsRootless() bool { // into a new user namespace and the return code from the re-executed podman process. // If podman was re-executed the caller needs to propagate the error code returned by the child // process. It is a convenience function for BecomeRootInUserNSWithOpts with a default configuration. -func BecomeRootInUserNS() (bool, int, error) { +func BecomeRootInUserNS(pausePid string) (bool, int, error) { return false, -1, errors.New("this function is not supported on this os") } @@ -28,6 +28,6 @@ func GetRootlessUID() int { // namespace of the specified PID without looking up its parent. Useful to join directly // the conmon process. It is a convenience function for JoinUserAndMountNSWithOpts // with a default configuration. -func JoinUserAndMountNS(pid uint) (bool, int, error) { +func JoinUserAndMountNS(pid uint, pausePid string) (bool, int, error) { return false, -1, errors.New("this function is not supported on this os") } diff --git a/pkg/spec/storage.go b/pkg/spec/storage.go index 55148b606..dcc149b55 100644 --- a/pkg/spec/storage.go +++ b/pkg/spec/storage.go @@ -135,6 +135,29 @@ func (config *CreateConfig) parseVolumes(runtime *libpod.Runtime) ([]spec.Mount, unifiedMounts[initMount.Destination] = initMount } + // Before superceding, we need to find volume mounts which conflict with + // named volumes, and vice versa. + // We'll delete the conflicts here as we supercede. + for dest := range unifiedMounts { + if _, ok := baseVolumes[dest]; ok { + delete(baseVolumes, dest) + } + } + for dest := range unifiedVolumes { + if _, ok := baseMounts[dest]; ok { + delete(baseMounts, dest) + } + } + + // Supercede volumes-from/image volumes with unified volumes from above. + // This is an unconditional replacement. + for dest, mount := range unifiedMounts { + baseMounts[dest] = mount + } + for dest, volume := range unifiedVolumes { + baseVolumes[dest] = volume + } + // If requested, add tmpfs filesystems for read-only containers. // Need to keep track of which we created, so we don't modify options // for them later... @@ -146,14 +169,14 @@ func (config *CreateConfig) parseVolumes(runtime *libpod.Runtime) ([]spec.Mount, if config.ReadOnlyRootfs && config.ReadOnlyTmpfs { options := []string{"rw", "rprivate", "nosuid", "nodev", "tmpcopyup", "size=65536k"} for dest := range readonlyTmpfs { - if _, ok := unifiedMounts[dest]; ok { + if _, ok := baseMounts[dest]; ok { continue } localOpts := options if dest == "/run" { localOpts = append(localOpts, "noexec") } - unifiedMounts[dest] = spec.Mount{ + baseMounts[dest] = spec.Mount{ Destination: dest, Type: "tmpfs", Source: "tmpfs", @@ -163,15 +186,6 @@ func (config *CreateConfig) parseVolumes(runtime *libpod.Runtime) ([]spec.Mount, } } - // Supercede volumes-from/image volumes with unified volumes from above. - // This is an unconditional replacement. - for dest, mount := range unifiedMounts { - baseMounts[dest] = mount - } - for dest, volume := range unifiedVolumes { - baseVolumes[dest] = volume - } - // Check for conflicts between named volumes and mounts for dest := range baseMounts { if _, ok := baseVolumes[dest]; ok { diff --git a/pkg/util/utils_supported.go b/pkg/util/utils_supported.go index 8b98658c2..3d9140a23 100644 --- a/pkg/util/utils_supported.go +++ b/pkg/util/utils_supported.go @@ -82,3 +82,13 @@ func GetRootlessRuntimeDir() (string, error) { } return rootlessRuntimeDir, nil } + +// GetRootlessPauseProcessPidPath returns the path to the file that holds the pid for +// the pause process +func GetRootlessPauseProcessPidPath() (string, error) { + runtimeDir, err := GetRootlessRuntimeDir() + if err != nil { + return "", err + } + return filepath.Join(runtimeDir, "libpod", "pause.pid"), nil +} diff --git a/pkg/util/utils_windows.go b/pkg/util/utils_windows.go index b33733da9..3faa6f10c 100644 --- a/pkg/util/utils_windows.go +++ b/pkg/util/utils_windows.go @@ -15,3 +15,9 @@ func GetRootlessRuntimeDir() (string, error) { func IsCgroup2UnifiedMode() (bool, error) { return false, errors.New("this function is not implemented for windows") } + +// GetRootlessPauseProcessPidPath returns the path to the file that holds the pid for +// the pause process +func GetRootlessPauseProcessPidPath() (string, error) { + return "", errors.New("this function is not implemented for windows") +} |