src/core/execute.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 typedef struct ExecStatus ExecStatus;
   5 typedef struct ExecCommand ExecCommand;
   6 typedef struct ExecContext ExecContext;
   7 typedef struct ExecRuntime ExecRuntime;
   8 typedef struct ExecParameters ExecParameters;
   9 typedef struct Manager Manager;
  10
  11 #include <sched.h>
  12 #include <stdbool.h>
  13 #include <stdio.h>
  14 #include <sys/capability.h>
  15
  16 #include "cgroup-util.h"
  17 #include "fdset.h"
  18 #include "list.h"
  19 #include "missing.h"
  20 #include "namespace.h"
  21 #include "nsflags.h"
  22
  23 #define EXEC_STDIN_DATA_MAX (64U*1024U*1024U)
  24
  25 typedef enum ExecUtmpMode {
  26         EXEC_UTMP_INIT,
  27         EXEC_UTMP_LOGIN,
  28         EXEC_UTMP_USER,
  29         _EXEC_UTMP_MODE_MAX,
  30         _EXEC_UTMP_MODE_INVALID = -1
  31 } ExecUtmpMode;
  32
  33 typedef enum ExecInput {
  34         EXEC_INPUT_NULL,
  35         EXEC_INPUT_TTY,
  36         EXEC_INPUT_TTY_FORCE,
  37         EXEC_INPUT_TTY_FAIL,
  38         EXEC_INPUT_SOCKET,
  39         EXEC_INPUT_NAMED_FD,
  40         EXEC_INPUT_DATA,
  41         EXEC_INPUT_FILE,
  42         _EXEC_INPUT_MAX,
  43         _EXEC_INPUT_INVALID = -1
  44 } ExecInput;
  45
  46 typedef enum ExecOutput {
  47         EXEC_OUTPUT_INHERIT,
  48         EXEC_OUTPUT_NULL,
  49         EXEC_OUTPUT_TTY,
  50         EXEC_OUTPUT_SYSLOG,
  51         EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
  52         EXEC_OUTPUT_KMSG,
  53         EXEC_OUTPUT_KMSG_AND_CONSOLE,
  54         EXEC_OUTPUT_JOURNAL,
  55         EXEC_OUTPUT_JOURNAL_AND_CONSOLE,
  56         EXEC_OUTPUT_SOCKET,
  57         EXEC_OUTPUT_NAMED_FD,
  58         EXEC_OUTPUT_FILE,
  59         _EXEC_OUTPUT_MAX,
  60         _EXEC_OUTPUT_INVALID = -1
  61 } ExecOutput;
  62
  63 typedef enum ExecPreserveMode {
  64         EXEC_PRESERVE_NO,
  65         EXEC_PRESERVE_YES,
  66         EXEC_PRESERVE_RESTART,
  67         _EXEC_PRESERVE_MODE_MAX,
  68         _EXEC_PRESERVE_MODE_INVALID = -1
  69 } ExecPreserveMode;
  70
  71 typedef enum ExecKeyringMode {
  72         EXEC_KEYRING_INHERIT,
  73         EXEC_KEYRING_PRIVATE,
  74         EXEC_KEYRING_SHARED,
  75         _EXEC_KEYRING_MODE_MAX,
  76         _EXEC_KEYRING_MODE_INVALID = -1,
  77 } ExecKeyringMode;
  78
  79 struct ExecStatus {
  80         dual_timestamp start_timestamp;
  81         dual_timestamp exit_timestamp;
  82         pid_t pid;
  83         int code;     /* as in siginfo_t::si_code */
  84         int status;   /* as in sigingo_t::si_status */
  85 };
  86
  87 typedef enum ExecCommandFlags {
  88         EXEC_COMMAND_IGNORE_FAILURE = 1,
  89         EXEC_COMMAND_FULLY_PRIVILEGED = 2,
  90         EXEC_COMMAND_NO_SETUID = 4,
  91         EXEC_COMMAND_AMBIENT_MAGIC = 8,
  92 } ExecCommandFlags;
  93
  94 struct ExecCommand {
  95         char *path;
  96         char **argv;
  97         ExecStatus exec_status;
  98         ExecCommandFlags flags;
  99         LIST_FIELDS(ExecCommand, command); /* useful for chaining commands */
 100 };
 101
 102 struct ExecRuntime {
 103         int n_ref;
 104
 105         Manager *manager;
 106
 107         /* unit id of the owner */
 108         char *id;
 109
 110         char *tmp_dir;
 111         char *var_tmp_dir;
 112
 113         /* An AF_UNIX socket pair, that contains a datagram containing a file descriptor referring to the network
 114          * namespace. */
 115         int netns_storage_socket[2];
 116 };
 117
 118 typedef enum ExecDirectoryType {
 119         EXEC_DIRECTORY_RUNTIME = 0,
 120         EXEC_DIRECTORY_STATE,
 121         EXEC_DIRECTORY_CACHE,
 122         EXEC_DIRECTORY_LOGS,
 123         EXEC_DIRECTORY_CONFIGURATION,
 124         _EXEC_DIRECTORY_TYPE_MAX,
 125         _EXEC_DIRECTORY_TYPE_INVALID = -1,
 126 } ExecDirectoryType;
 127
 128 typedef struct ExecDirectory {
 129         char **paths;
 130         mode_t mode;
 131 } ExecDirectory;
 132
 133 struct ExecContext {
 134         char **environment;
 135         char **environment_files;
 136         char **pass_environment;
 137         char **unset_environment;
 138
 139         struct rlimit *rlimit[_RLIMIT_MAX];
 140         char *working_directory, *root_directory, *root_image;
 141         bool working_directory_missing_ok;
 142         bool working_directory_home;
 143
 144         mode_t umask;
 145         int oom_score_adjust;
 146         int nice;
 147         int ioprio;
 148         int cpu_sched_policy;
 149         int cpu_sched_priority;
 150
 151         cpu_set_t *cpuset;
 152         unsigned cpuset_ncpus;
 153
 154         ExecInput std_input;
 155         ExecOutput std_output;
 156         ExecOutput std_error;
 157         char *stdio_fdname[3];
 158         char *stdio_file[3];
 159
 160         void *stdin_data;
 161         size_t stdin_data_size;
 162
 163         nsec_t timer_slack_nsec;
 164
 165         bool stdio_as_fds;
 166
 167         char *tty_path;
 168
 169         bool tty_reset;
 170         bool tty_vhangup;
 171         bool tty_vt_disallocate;
 172
 173         bool ignore_sigpipe;
 174
 175         /* Since resolving these names might involve socket
 176          * connections and we don't want to deadlock ourselves these
 177          * names are resolved on execution only and in the child
 178          * process. */
 179         char *user;
 180         char *group;
 181         char **supplementary_groups;
 182
 183         char *pam_name;
 184
 185         char *utmp_id;
 186         ExecUtmpMode utmp_mode;
 187
 188         bool selinux_context_ignore;
 189         char *selinux_context;
 190
 191         bool apparmor_profile_ignore;
 192         char *apparmor_profile;
 193
 194         bool smack_process_label_ignore;
 195         char *smack_process_label;
 196
 197         ExecKeyringMode keyring_mode;
 198
 199         char **read_write_paths, **read_only_paths, **inaccessible_paths;
 200         unsigned long mount_flags;
 201         BindMount *bind_mounts;
 202         size_t n_bind_mounts;
 203         TemporaryFileSystem *temporary_filesystems;
 204         size_t n_temporary_filesystems;
 205
 206         uint64_t capability_bounding_set;
 207         uint64_t capability_ambient_set;
 208         int secure_bits;
 209
 210         int syslog_priority;
 211         char *syslog_identifier;
 212         bool syslog_level_prefix;
 213
 214         int log_level_max;
 215
 216         struct iovec* log_extra_fields;
 217         size_t n_log_extra_fields;
 218
 219         bool cpu_sched_reset_on_fork;
 220         bool non_blocking;
 221         bool private_tmp;
 222         bool private_network;
 223         bool private_devices;
 224         bool private_users;
 225         bool private_mounts;
 226         ProtectSystem protect_system;
 227         ProtectHome protect_home;
 228         bool protect_kernel_tunables;
 229         bool protect_kernel_modules;
 230         bool protect_control_groups;
 231         bool mount_apivfs;
 232
 233         bool no_new_privileges;
 234
 235         bool dynamic_user;
 236         bool remove_ipc;
 237
 238         /* This is not exposed to the user but available
 239          * internally. We need it to make sure that whenever we spawn
 240          * /usr/bin/mount it is run in the same process group as us so
 241          * that the autofs logic detects that it belongs to us and we
 242          * don't enter a trigger loop. */
 243         bool same_pgrp;
 244
 245         unsigned long personality;
 246         bool lock_personality;
 247
 248         unsigned long restrict_namespaces; /* The CLONE_NEWxyz flags permitted to the unit's processes */
 249
 250         Hashmap *syscall_filter;
 251         Set *syscall_archs;
 252         int syscall_errno;
 253         bool syscall_whitelist:1;
 254
 255         Set *address_families;
 256         bool address_families_whitelist:1;
 257
 258         ExecPreserveMode runtime_directory_preserve_mode;
 259         ExecDirectory directories[_EXEC_DIRECTORY_TYPE_MAX];
 260
 261         bool memory_deny_write_execute;
 262         bool restrict_realtime;
 263
 264         bool oom_score_adjust_set:1;
 265         bool nice_set:1;
 266         bool ioprio_set:1;
 267         bool cpu_sched_set:1;
 268 };
 269
 270 static inline bool exec_context_restrict_namespaces_set(const ExecContext *c) {
 271         assert(c);
 272
 273         return (c->restrict_namespaces & NAMESPACE_FLAGS_ALL) != NAMESPACE_FLAGS_ALL;
 274 }
 275
 276 typedef enum ExecFlags {
 277         EXEC_APPLY_SANDBOXING  = 1 << 0,
 278         EXEC_APPLY_CHROOT      = 1 << 1,
 279         EXEC_APPLY_TTY_STDIN   = 1 << 2,
 280         EXEC_NEW_KEYRING       = 1 << 3,
 281         EXEC_PASS_LOG_UNIT     = 1 << 4, /* Whether to pass the unit name to the service's journal stream connection */
 282         EXEC_CHOWN_DIRECTORIES = 1 << 5, /* chown() the runtime/state/cache/log directories to the user we run as, under all conditions */
 283         EXEC_NSS_BYPASS_BUS    = 1 << 6, /* Set the SYSTEMD_NSS_BYPASS_BUS environment variable, to disable nss-systemd for dbus */
 284         EXEC_CGROUP_DELEGATE   = 1 << 7,
 285
 286         /* The following are not used by execute.c, but by consumers internally */
 287         EXEC_PASS_FDS          = 1 << 8,
 288         EXEC_IS_CONTROL        = 1 << 9,
 289         EXEC_SETENV_RESULT     = 1 << 10,
 290         EXEC_SET_WATCHDOG      = 1 << 11,
 291 } ExecFlags;
 292
 293 struct ExecParameters {
 294         char **argv;
 295         char **environment;
 296
 297         int *fds;
 298         char **fd_names;
 299         size_t n_storage_fds;
 300         size_t n_socket_fds;
 301
 302         ExecFlags flags;
 303         bool selinux_context_net:1;
 304
 305         CGroupMask cgroup_supported;
 306         const char *cgroup_path;
 307
 308         char **prefix;
 309
 310         const char *confirm_spawn;
 311
 312         usec_t watchdog_usec;
 313
 314         int *idle_pipe;
 315
 316         int stdin_fd;
 317         int stdout_fd;
 318         int stderr_fd;
 319 };
 320
 321 #include "unit.h"
 322 #include "dynamic-user.h"
 323
 324 int exec_spawn(Unit *unit,
 325                ExecCommand *command,
 326                const ExecContext *context,
 327                const ExecParameters *exec_params,
 328                ExecRuntime *runtime,
 329                DynamicCreds *dynamic_creds,
 330                pid_t *ret);
 331
 332 void exec_command_done_array(ExecCommand *c, size_t n);
 333
 334 ExecCommand* exec_command_free_list(ExecCommand *c);
 335 void exec_command_free_array(ExecCommand **c, size_t n);
 336
 337 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix);
 338 void exec_command_append_list(ExecCommand **l, ExecCommand *e);
 339 int exec_command_set(ExecCommand *c, const char *path, ...);
 340 int exec_command_append(ExecCommand *c, const char *path, ...);
 341
 342 void exec_context_init(ExecContext *c);
 343 void exec_context_done(ExecContext *c);
 344 void exec_context_dump(const ExecContext *c, FILE* f, const char *prefix);
 345
 346 int exec_context_destroy_runtime_directory(const ExecContext *c, const char *runtime_root);
 347
 348 const char* exec_context_fdname(const ExecContext *c, int fd_index);
 349
 350 bool exec_context_may_touch_console(const ExecContext *c);
 351 bool exec_context_maintains_privileges(const ExecContext *c);
 352
 353 int exec_context_get_effective_ioprio(const ExecContext *c);
 354
 355 void exec_context_free_log_extra_fields(ExecContext *c);
 356
 357 void exec_status_start(ExecStatus *s, pid_t pid);
 358 void exec_status_exit(ExecStatus *s, const ExecContext *context, pid_t pid, int code, int status);
 359 void exec_status_dump(const ExecStatus *s, FILE *f, const char *prefix);
 360
 361 int exec_runtime_acquire(Manager *m, const ExecContext *c, const char *name, bool create, ExecRuntime **ret);
 362 ExecRuntime *exec_runtime_unref(ExecRuntime *r, bool destroy);
 363
 364 int exec_runtime_serialize(const Manager *m, FILE *f, FDSet *fds);
 365 int exec_runtime_deserialize_compat(Unit *u, const char *key, const char *value, FDSet *fds);
 366 void exec_runtime_deserialize_one(Manager *m, const char *value, FDSet *fds);
 367 void exec_runtime_vacuum(Manager *m);
 368
 369 const char* exec_output_to_string(ExecOutput i) _const_;
 370 ExecOutput exec_output_from_string(const char *s) _pure_;
 371
 372 const char* exec_input_to_string(ExecInput i) _const_;
 373 ExecInput exec_input_from_string(const char *s) _pure_;
 374
 375 const char* exec_utmp_mode_to_string(ExecUtmpMode i) _const_;
 376 ExecUtmpMode exec_utmp_mode_from_string(const char *s) _pure_;
 377
 378 const char* exec_preserve_mode_to_string(ExecPreserveMode i) _const_;
 379 ExecPreserveMode exec_preserve_mode_from_string(const char *s) _pure_;
 380
 381 const char* exec_keyring_mode_to_string(ExecKeyringMode i) _const_;
 382 ExecKeyringMode exec_keyring_mode_from_string(const char *s) _pure_;
 383
 384 const char* exec_directory_type_to_string(ExecDirectoryType i) _const_;
 385 ExecDirectoryType exec_directory_type_from_string(const char *s) _pure_;