src/core/execute.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 /***
   5   This file is part of systemd.
   6
   7   Copyright 2010 Lennart Poettering
   8 ***/
   9
  10 typedef struct ExecStatus ExecStatus;
  11 typedef struct ExecCommand ExecCommand;
  12 typedef struct ExecContext ExecContext;
  13 typedef struct ExecRuntime ExecRuntime;
  14 typedef struct ExecParameters ExecParameters;
  15 typedef struct Manager Manager;
  16
  17 #include <sched.h>
  18 #include <stdbool.h>
  19 #include <stdio.h>
  20 #include <sys/capability.h>
  21
  22 #include "cgroup-util.h"
  23 #include "fdset.h"
  24 #include "list.h"
  25 #include "missing.h"
  26 #include "namespace.h"
  27 #include "nsflags.h"
  28
  29 #define EXEC_STDIN_DATA_MAX (64U*1024U*1024U)
  30
  31 typedef enum ExecUtmpMode {
  32         EXEC_UTMP_INIT,
  33         EXEC_UTMP_LOGIN,
  34         EXEC_UTMP_USER,
  35         _EXEC_UTMP_MODE_MAX,
  36         _EXEC_UTMP_MODE_INVALID = -1
  37 } ExecUtmpMode;
  38
  39 typedef enum ExecInput {
  40         EXEC_INPUT_NULL,
  41         EXEC_INPUT_TTY,
  42         EXEC_INPUT_TTY_FORCE,
  43         EXEC_INPUT_TTY_FAIL,
  44         EXEC_INPUT_SOCKET,
  45         EXEC_INPUT_NAMED_FD,
  46         EXEC_INPUT_DATA,
  47         EXEC_INPUT_FILE,
  48         _EXEC_INPUT_MAX,
  49         _EXEC_INPUT_INVALID = -1
  50 } ExecInput;
  51
  52 typedef enum ExecOutput {
  53         EXEC_OUTPUT_INHERIT,
  54         EXEC_OUTPUT_NULL,
  55         EXEC_OUTPUT_TTY,
  56         EXEC_OUTPUT_SYSLOG,
  57         EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
  58         EXEC_OUTPUT_KMSG,
  59         EXEC_OUTPUT_KMSG_AND_CONSOLE,
  60         EXEC_OUTPUT_JOURNAL,
  61         EXEC_OUTPUT_JOURNAL_AND_CONSOLE,
  62         EXEC_OUTPUT_SOCKET,
  63         EXEC_OUTPUT_NAMED_FD,
  64         EXEC_OUTPUT_FILE,
  65         _EXEC_OUTPUT_MAX,
  66         _EXEC_OUTPUT_INVALID = -1
  67 } ExecOutput;
  68
  69 typedef enum ExecPreserveMode {
  70         EXEC_PRESERVE_NO,
  71         EXEC_PRESERVE_YES,
  72         EXEC_PRESERVE_RESTART,
  73         _EXEC_PRESERVE_MODE_MAX,
  74         _EXEC_PRESERVE_MODE_INVALID = -1
  75 } ExecPreserveMode;
  76
  77 typedef enum ExecKeyringMode {
  78         EXEC_KEYRING_INHERIT,
  79         EXEC_KEYRING_PRIVATE,
  80         EXEC_KEYRING_SHARED,
  81         _EXEC_KEYRING_MODE_MAX,
  82         _EXEC_KEYRING_MODE_INVALID = -1,
  83 } ExecKeyringMode;
  84
  85 struct ExecStatus {
  86         dual_timestamp start_timestamp;
  87         dual_timestamp exit_timestamp;
  88         pid_t pid;
  89         int code;     /* as in siginfo_t::si_code */
  90         int status;   /* as in sigingo_t::si_status */
  91 };
  92
  93 typedef enum ExecCommandFlags {
  94         EXEC_COMMAND_IGNORE_FAILURE = 1,
  95         EXEC_COMMAND_FULLY_PRIVILEGED = 2,
  96         EXEC_COMMAND_NO_SETUID = 4,
  97         EXEC_COMMAND_AMBIENT_MAGIC = 8,
  98 } ExecCommandFlags;
  99
 100 struct ExecCommand {
 101         char *path;
 102         char **argv;
 103         ExecStatus exec_status;
 104         ExecCommandFlags flags;
 105         LIST_FIELDS(ExecCommand, command); /* useful for chaining commands */
 106 };
 107
 108 struct ExecRuntime {
 109         int n_ref;
 110
 111         Manager *manager;
 112
 113         /* unit id of the owner */
 114         char *id;
 115
 116         char *tmp_dir;
 117         char *var_tmp_dir;
 118
 119         /* An AF_UNIX socket pair, that contains a datagram containing a file descriptor referring to the network
 120          * namespace. */
 121         int netns_storage_socket[2];
 122 };
 123
 124 typedef enum ExecDirectoryType {
 125         EXEC_DIRECTORY_RUNTIME = 0,
 126         EXEC_DIRECTORY_STATE,
 127         EXEC_DIRECTORY_CACHE,
 128         EXEC_DIRECTORY_LOGS,
 129         EXEC_DIRECTORY_CONFIGURATION,
 130         _EXEC_DIRECTORY_TYPE_MAX,
 131         _EXEC_DIRECTORY_TYPE_INVALID = -1,
 132 } ExecDirectoryType;
 133
 134 typedef struct ExecDirectory {
 135         char **paths;
 136         mode_t mode;
 137 } ExecDirectory;
 138
 139 struct ExecContext {
 140         char **environment;
 141         char **environment_files;
 142         char **pass_environment;
 143         char **unset_environment;
 144
 145         struct rlimit *rlimit[_RLIMIT_MAX];
 146         char *working_directory, *root_directory, *root_image;
 147         bool working_directory_missing_ok;
 148         bool working_directory_home;
 149
 150         mode_t umask;
 151         int oom_score_adjust;
 152         int nice;
 153         int ioprio;
 154         int cpu_sched_policy;
 155         int cpu_sched_priority;
 156
 157         cpu_set_t *cpuset;
 158         unsigned cpuset_ncpus;
 159
 160         ExecInput std_input;
 161         ExecOutput std_output;
 162         ExecOutput std_error;
 163         char *stdio_fdname[3];
 164         char *stdio_file[3];
 165
 166         void *stdin_data;
 167         size_t stdin_data_size;
 168
 169         nsec_t timer_slack_nsec;
 170
 171         bool stdio_as_fds;
 172
 173         char *tty_path;
 174
 175         bool tty_reset;
 176         bool tty_vhangup;
 177         bool tty_vt_disallocate;
 178
 179         bool ignore_sigpipe;
 180
 181         /* Since resolving these names might involve socket
 182          * connections and we don't want to deadlock ourselves these
 183          * names are resolved on execution only and in the child
 184          * process. */
 185         char *user;
 186         char *group;
 187         char **supplementary_groups;
 188
 189         char *pam_name;
 190
 191         char *utmp_id;
 192         ExecUtmpMode utmp_mode;
 193
 194         bool selinux_context_ignore;
 195         char *selinux_context;
 196
 197         bool apparmor_profile_ignore;
 198         char *apparmor_profile;
 199
 200         bool smack_process_label_ignore;
 201         char *smack_process_label;
 202
 203         ExecKeyringMode keyring_mode;
 204
 205         char **read_write_paths, **read_only_paths, **inaccessible_paths;
 206         unsigned long mount_flags;
 207         BindMount *bind_mounts;
 208         unsigned n_bind_mounts;
 209         TemporaryFileSystem *temporary_filesystems;
 210         unsigned n_temporary_filesystems;
 211
 212         uint64_t capability_bounding_set;
 213         uint64_t capability_ambient_set;
 214         int secure_bits;
 215
 216         int syslog_priority;
 217         char *syslog_identifier;
 218         bool syslog_level_prefix;
 219
 220         int log_level_max;
 221
 222         struct iovec* log_extra_fields;
 223         size_t n_log_extra_fields;
 224
 225         bool cpu_sched_reset_on_fork;
 226         bool non_blocking;
 227         bool private_tmp;
 228         bool private_network;
 229         bool private_devices;
 230         bool private_users;
 231         ProtectSystem protect_system;
 232         ProtectHome protect_home;
 233         bool protect_kernel_tunables;
 234         bool protect_kernel_modules;
 235         bool protect_control_groups;
 236         bool mount_apivfs;
 237
 238         bool no_new_privileges;
 239
 240         bool dynamic_user;
 241         bool remove_ipc;
 242
 243         /* This is not exposed to the user but available
 244          * internally. We need it to make sure that whenever we spawn
 245          * /usr/bin/mount it is run in the same process group as us so
 246          * that the autofs logic detects that it belongs to us and we
 247          * don't enter a trigger loop. */
 248         bool same_pgrp;
 249
 250         unsigned long personality;
 251         bool lock_personality;
 252
 253         unsigned long restrict_namespaces; /* The CLONE_NEWxyz flags permitted to the unit's processes */
 254
 255         Hashmap *syscall_filter;
 256         Set *syscall_archs;
 257         int syscall_errno;
 258         bool syscall_whitelist:1;
 259
 260         Set *address_families;
 261         bool address_families_whitelist:1;
 262
 263         ExecPreserveMode runtime_directory_preserve_mode;
 264         ExecDirectory directories[_EXEC_DIRECTORY_TYPE_MAX];
 265
 266         bool memory_deny_write_execute;
 267         bool restrict_realtime;
 268
 269         bool oom_score_adjust_set:1;
 270         bool nice_set:1;
 271         bool ioprio_set:1;
 272         bool cpu_sched_set:1;
 273 };
 274
 275 static inline bool exec_context_restrict_namespaces_set(const ExecContext *c) {
 276         assert(c);
 277
 278         return (c->restrict_namespaces & NAMESPACE_FLAGS_ALL) != NAMESPACE_FLAGS_ALL;
 279 }
 280
 281 typedef enum ExecFlags {
 282         EXEC_APPLY_SANDBOXING  = 1U << 0,
 283         EXEC_APPLY_CHROOT      = 1U << 1,
 284         EXEC_APPLY_TTY_STDIN   = 1U << 2,
 285         EXEC_NEW_KEYRING       = 1U << 3,
 286         EXEC_PASS_LOG_UNIT     = 1U << 4, /* Whether to pass the unit name to the service's journal stream connection */
 287         EXEC_CHOWN_DIRECTORIES = 1U << 5, /* chown() the runtime/state/cache/log directories to the user we run as, under all conditions */
 288         EXEC_NSS_BYPASS_BUS    = 1U << 6, /* Set the SYSTEMD_NSS_BYPASS_BUS environment variable, to disable nss-systemd for dbus */
 289         EXEC_CGROUP_DELEGATE   = 1U << 7,
 290
 291         /* The following are not used by execute.c, but by consumers internally */
 292         EXEC_PASS_FDS          = 1U << 8,
 293         EXEC_IS_CONTROL        = 1U << 9,
 294         EXEC_SETENV_RESULT     = 1U << 10,
 295         EXEC_SET_WATCHDOG      = 1U << 11,
 296 } ExecFlags;
 297
 298 struct ExecParameters {
 299         char **argv;
 300         char **environment;
 301
 302         int *fds;
 303         char **fd_names;
 304         unsigned n_storage_fds;
 305         unsigned n_socket_fds;
 306
 307         ExecFlags flags;
 308         bool selinux_context_net:1;
 309
 310         CGroupMask cgroup_supported;
 311         const char *cgroup_path;
 312
 313         char **prefix;
 314
 315         const char *confirm_spawn;
 316
 317         usec_t watchdog_usec;
 318
 319         int *idle_pipe;
 320
 321         int stdin_fd;
 322         int stdout_fd;
 323         int stderr_fd;
 324 };
 325
 326 #include "unit.h"
 327 #include "dynamic-user.h"
 328
 329 int exec_spawn(Unit *unit,
 330                ExecCommand *command,
 331                const ExecContext *context,
 332                const ExecParameters *exec_params,
 333                ExecRuntime *runtime,
 334                DynamicCreds *dynamic_creds,
 335                pid_t *ret);
 336
 337 void exec_command_done_array(ExecCommand *c, unsigned n);
 338
 339 ExecCommand* exec_command_free_list(ExecCommand *c);
 340 void exec_command_free_array(ExecCommand **c, unsigned n);
 341
 342 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix);
 343 void exec_command_append_list(ExecCommand **l, ExecCommand *e);
 344 int exec_command_set(ExecCommand *c, const char *path, ...);
 345 int exec_command_append(ExecCommand *c, const char *path, ...);
 346
 347 void exec_context_init(ExecContext *c);
 348 void exec_context_done(ExecContext *c);
 349 void exec_context_dump(const ExecContext *c, FILE* f, const char *prefix);
 350
 351 int exec_context_destroy_runtime_directory(const ExecContext *c, const char *runtime_root);
 352
 353 const char* exec_context_fdname(const ExecContext *c, int fd_index);
 354
 355 bool exec_context_may_touch_console(const ExecContext *c);
 356 bool exec_context_maintains_privileges(const ExecContext *c);
 357
 358 int exec_context_get_effective_ioprio(const ExecContext *c);
 359
 360 void exec_context_free_log_extra_fields(ExecContext *c);
 361
 362 void exec_status_start(ExecStatus *s, pid_t pid);
 363 void exec_status_exit(ExecStatus *s, const ExecContext *context, pid_t pid, int code, int status);
 364 void exec_status_dump(const ExecStatus *s, FILE *f, const char *prefix);
 365
 366 int exec_runtime_acquire(Manager *m, const ExecContext *c, const char *name, bool create, ExecRuntime **ret);
 367 ExecRuntime *exec_runtime_unref(ExecRuntime *r, bool destroy);
 368
 369 int exec_runtime_serialize(const Manager *m, FILE *f, FDSet *fds);
 370 int exec_runtime_deserialize_compat(Unit *u, const char *key, const char *value, FDSet *fds);
 371 void exec_runtime_deserialize_one(Manager *m, const char *value, FDSet *fds);
 372 void exec_runtime_vacuum(Manager *m);
 373
 374 const char* exec_output_to_string(ExecOutput i) _const_;
 375 ExecOutput exec_output_from_string(const char *s) _pure_;
 376
 377 const char* exec_input_to_string(ExecInput i) _const_;
 378 ExecInput exec_input_from_string(const char *s) _pure_;
 379
 380 const char* exec_utmp_mode_to_string(ExecUtmpMode i) _const_;
 381 ExecUtmpMode exec_utmp_mode_from_string(const char *s) _pure_;
 382
 383 const char* exec_preserve_mode_to_string(ExecPreserveMode i) _const_;
 384 ExecPreserveMode exec_preserve_mode_from_string(const char *s) _pure_;
 385
 386 const char* exec_keyring_mode_to_string(ExecKeyringMode i) _const_;
 387 ExecKeyringMode exec_keyring_mode_from_string(const char *s) _pure_;
 388
 389 const char* exec_directory_type_to_string(ExecDirectoryType i) _const_;
 390 ExecDirectoryType exec_directory_type_from_string(const char *s) _pure_;