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   systemd is free software; you can redistribute it and/or modify it
  10   under the terms of the GNU Lesser General Public License as published by
  11   the Free Software Foundation; either version 2.1 of the License, or
  12   (at your option) any later version.
  13
  14   systemd is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   Lesser General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public License
  20   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  21 ***/
  22
  23 typedef struct ExecStatus ExecStatus;
  24 typedef struct ExecCommand ExecCommand;
  25 typedef struct ExecContext ExecContext;
  26 typedef struct ExecRuntime ExecRuntime;
  27 typedef struct ExecParameters ExecParameters;
  28 typedef struct Manager Manager;
  29
  30 #include <sched.h>
  31 #include <stdbool.h>
  32 #include <stdio.h>
  33 #include <sys/capability.h>
  34
  35 #include "cgroup-util.h"
  36 #include "fdset.h"
  37 #include "list.h"
  38 #include "missing.h"
  39 #include "namespace.h"
  40 #include "nsflags.h"
  41
  42 #define EXEC_STDIN_DATA_MAX (64U*1024U*1024U)
  43
  44 typedef enum ExecUtmpMode {
  45         EXEC_UTMP_INIT,
  46         EXEC_UTMP_LOGIN,
  47         EXEC_UTMP_USER,
  48         _EXEC_UTMP_MODE_MAX,
  49         _EXEC_UTMP_MODE_INVALID = -1
  50 } ExecUtmpMode;
  51
  52 typedef enum ExecInput {
  53         EXEC_INPUT_NULL,
  54         EXEC_INPUT_TTY,
  55         EXEC_INPUT_TTY_FORCE,
  56         EXEC_INPUT_TTY_FAIL,
  57         EXEC_INPUT_SOCKET,
  58         EXEC_INPUT_NAMED_FD,
  59         EXEC_INPUT_DATA,
  60         EXEC_INPUT_FILE,
  61         _EXEC_INPUT_MAX,
  62         _EXEC_INPUT_INVALID = -1
  63 } ExecInput;
  64
  65 typedef enum ExecOutput {
  66         EXEC_OUTPUT_INHERIT,
  67         EXEC_OUTPUT_NULL,
  68         EXEC_OUTPUT_TTY,
  69         EXEC_OUTPUT_SYSLOG,
  70         EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
  71         EXEC_OUTPUT_KMSG,
  72         EXEC_OUTPUT_KMSG_AND_CONSOLE,
  73         EXEC_OUTPUT_JOURNAL,
  74         EXEC_OUTPUT_JOURNAL_AND_CONSOLE,
  75         EXEC_OUTPUT_SOCKET,
  76         EXEC_OUTPUT_NAMED_FD,
  77         EXEC_OUTPUT_FILE,
  78         _EXEC_OUTPUT_MAX,
  79         _EXEC_OUTPUT_INVALID = -1
  80 } ExecOutput;
  81
  82 typedef enum ExecPreserveMode {
  83         EXEC_PRESERVE_NO,
  84         EXEC_PRESERVE_YES,
  85         EXEC_PRESERVE_RESTART,
  86         _EXEC_PRESERVE_MODE_MAX,
  87         _EXEC_PRESERVE_MODE_INVALID = -1
  88 } ExecPreserveMode;
  89
  90 typedef enum ExecKeyringMode {
  91         EXEC_KEYRING_INHERIT,
  92         EXEC_KEYRING_PRIVATE,
  93         EXEC_KEYRING_SHARED,
  94         _EXEC_KEYRING_MODE_MAX,
  95         _EXEC_KEYRING_MODE_INVALID = -1,
  96 } ExecKeyringMode;
  97
  98 struct ExecStatus {
  99         dual_timestamp start_timestamp;
 100         dual_timestamp exit_timestamp;
 101         pid_t pid;
 102         int code;     /* as in siginfo_t::si_code */
 103         int status;   /* as in sigingo_t::si_status */
 104 };
 105
 106 typedef enum ExecCommandFlags {
 107         EXEC_COMMAND_IGNORE_FAILURE = 1,
 108         EXEC_COMMAND_FULLY_PRIVILEGED = 2,
 109         EXEC_COMMAND_NO_SETUID = 4,
 110         EXEC_COMMAND_AMBIENT_MAGIC = 8,
 111 } ExecCommandFlags;
 112
 113 struct ExecCommand {
 114         char *path;
 115         char **argv;
 116         ExecStatus exec_status;
 117         ExecCommandFlags flags;
 118         LIST_FIELDS(ExecCommand, command); /* useful for chaining commands */
 119 };
 120
 121 struct ExecRuntime {
 122         int n_ref;
 123
 124         Manager *manager;
 125
 126         /* unit id of the owner */
 127         char *id;
 128
 129         char *tmp_dir;
 130         char *var_tmp_dir;
 131
 132         /* An AF_UNIX socket pair, that contains a datagram containing a file descriptor referring to the network
 133          * namespace. */
 134         int netns_storage_socket[2];
 135 };
 136
 137 typedef enum ExecDirectoryType {
 138         EXEC_DIRECTORY_RUNTIME = 0,
 139         EXEC_DIRECTORY_STATE,
 140         EXEC_DIRECTORY_CACHE,
 141         EXEC_DIRECTORY_LOGS,
 142         EXEC_DIRECTORY_CONFIGURATION,
 143         _EXEC_DIRECTORY_TYPE_MAX,
 144         _EXEC_DIRECTORY_TYPE_INVALID = -1,
 145 } ExecDirectoryType;
 146
 147 typedef struct ExecDirectory {
 148         char **paths;
 149         mode_t mode;
 150 } ExecDirectory;
 151
 152 struct ExecContext {
 153         char **environment;
 154         char **environment_files;
 155         char **pass_environment;
 156         char **unset_environment;
 157
 158         struct rlimit *rlimit[_RLIMIT_MAX];
 159         char *working_directory, *root_directory, *root_image;
 160         bool working_directory_missing_ok;
 161         bool working_directory_home;
 162
 163         mode_t umask;
 164         int oom_score_adjust;
 165         int nice;
 166         int ioprio;
 167         int cpu_sched_policy;
 168         int cpu_sched_priority;
 169
 170         cpu_set_t *cpuset;
 171         unsigned cpuset_ncpus;
 172
 173         ExecInput std_input;
 174         ExecOutput std_output;
 175         ExecOutput std_error;
 176         char *stdio_fdname[3];
 177         char *stdio_file[3];
 178
 179         void *stdin_data;
 180         size_t stdin_data_size;
 181
 182         nsec_t timer_slack_nsec;
 183
 184         bool stdio_as_fds;
 185
 186         char *tty_path;
 187
 188         bool tty_reset;
 189         bool tty_vhangup;
 190         bool tty_vt_disallocate;
 191
 192         bool ignore_sigpipe;
 193
 194         /* Since resolving these names might involve socket
 195          * connections and we don't want to deadlock ourselves these
 196          * names are resolved on execution only and in the child
 197          * process. */
 198         char *user;
 199         char *group;
 200         char **supplementary_groups;
 201
 202         char *pam_name;
 203
 204         char *utmp_id;
 205         ExecUtmpMode utmp_mode;
 206
 207         bool selinux_context_ignore;
 208         char *selinux_context;
 209
 210         bool apparmor_profile_ignore;
 211         char *apparmor_profile;
 212
 213         bool smack_process_label_ignore;
 214         char *smack_process_label;
 215
 216         ExecKeyringMode keyring_mode;
 217
 218         char **read_write_paths, **read_only_paths, **inaccessible_paths;
 219         unsigned long mount_flags;
 220         BindMount *bind_mounts;
 221         unsigned n_bind_mounts;
 222
 223         uint64_t capability_bounding_set;
 224         uint64_t capability_ambient_set;
 225         int secure_bits;
 226
 227         int syslog_priority;
 228         char *syslog_identifier;
 229         bool syslog_level_prefix;
 230
 231         int log_level_max;
 232
 233         struct iovec* log_extra_fields;
 234         size_t n_log_extra_fields;
 235
 236         bool cpu_sched_reset_on_fork;
 237         bool non_blocking;
 238         bool private_tmp;
 239         bool private_network;
 240         bool private_devices;
 241         bool private_users;
 242         ProtectSystem protect_system;
 243         ProtectHome protect_home;
 244         bool protect_kernel_tunables;
 245         bool protect_kernel_modules;
 246         bool protect_control_groups;
 247         bool mount_apivfs;
 248
 249         bool no_new_privileges;
 250
 251         bool dynamic_user;
 252         bool remove_ipc;
 253
 254         /* This is not exposed to the user but available
 255          * internally. We need it to make sure that whenever we spawn
 256          * /usr/bin/mount it is run in the same process group as us so
 257          * that the autofs logic detects that it belongs to us and we
 258          * don't enter a trigger loop. */
 259         bool same_pgrp;
 260
 261         unsigned long personality;
 262         bool lock_personality;
 263
 264         unsigned long restrict_namespaces; /* The CLONE_NEWxyz flags permitted to the unit's processes */
 265
 266         Hashmap *syscall_filter;
 267         Set *syscall_archs;
 268         int syscall_errno;
 269         bool syscall_whitelist:1;
 270
 271         Set *address_families;
 272         bool address_families_whitelist:1;
 273
 274         ExecPreserveMode runtime_directory_preserve_mode;
 275         ExecDirectory directories[_EXEC_DIRECTORY_TYPE_MAX];
 276
 277         bool memory_deny_write_execute;
 278         bool restrict_realtime;
 279
 280         bool oom_score_adjust_set:1;
 281         bool nice_set:1;
 282         bool ioprio_set:1;
 283         bool cpu_sched_set:1;
 284 };
 285
 286 static inline bool exec_context_restrict_namespaces_set(const ExecContext *c) {
 287         assert(c);
 288
 289         return (c->restrict_namespaces & NAMESPACE_FLAGS_ALL) != NAMESPACE_FLAGS_ALL;
 290 }
 291
 292 typedef enum ExecFlags {
 293         EXEC_APPLY_SANDBOXING  = 1U << 0,
 294         EXEC_APPLY_CHROOT      = 1U << 1,
 295         EXEC_APPLY_TTY_STDIN   = 1U << 2,
 296         EXEC_NEW_KEYRING       = 1U << 3,
 297         EXEC_PASS_LOG_UNIT     = 1U << 4, /* Whether to pass the unit name to the service's journal stream connection */
 298         EXEC_CHOWN_DIRECTORIES = 1U << 5, /* chown() the runtime/state/cache/log directories to the user we run as, under all conditions */
 299         EXEC_NSS_BYPASS_BUS    = 1U << 6, /* Set the SYSTEMD_NSS_BYPASS_BUS environment variable, to disable nss-systemd for dbus */
 300         EXEC_CGROUP_DELEGATE   = 1U << 7,
 301
 302         /* The following are not used by execute.c, but by consumers internally */
 303         EXEC_PASS_FDS          = 1U << 8,
 304         EXEC_IS_CONTROL        = 1U << 9,
 305         EXEC_SETENV_RESULT     = 1U << 10,
 306         EXEC_SET_WATCHDOG      = 1U << 11,
 307 } ExecFlags;
 308
 309 struct ExecParameters {
 310         char **argv;
 311         char **environment;
 312
 313         int *fds;
 314         char **fd_names;
 315         unsigned n_storage_fds;
 316         unsigned n_socket_fds;
 317
 318         ExecFlags flags;
 319         bool selinux_context_net:1;
 320
 321         CGroupMask cgroup_supported;
 322         const char *cgroup_path;
 323
 324         char **prefix;
 325
 326         const char *confirm_spawn;
 327
 328         usec_t watchdog_usec;
 329
 330         int *idle_pipe;
 331
 332         int stdin_fd;
 333         int stdout_fd;
 334         int stderr_fd;
 335 };
 336
 337 #include "unit.h"
 338 #include "dynamic-user.h"
 339
 340 int exec_spawn(Unit *unit,
 341                ExecCommand *command,
 342                const ExecContext *context,
 343                const ExecParameters *exec_params,
 344                ExecRuntime *runtime,
 345                DynamicCreds *dynamic_creds,
 346                pid_t *ret);
 347
 348 void exec_command_done_array(ExecCommand *c, unsigned n);
 349
 350 ExecCommand* exec_command_free_list(ExecCommand *c);
 351 void exec_command_free_array(ExecCommand **c, unsigned n);
 352
 353 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix);
 354 void exec_command_append_list(ExecCommand **l, ExecCommand *e);
 355 int exec_command_set(ExecCommand *c, const char *path, ...);
 356 int exec_command_append(ExecCommand *c, const char *path, ...);
 357
 358 void exec_context_init(ExecContext *c);
 359 void exec_context_done(ExecContext *c);
 360 void exec_context_dump(const ExecContext *c, FILE* f, const char *prefix);
 361
 362 int exec_context_destroy_runtime_directory(const ExecContext *c, const char *runtime_root);
 363
 364 const char* exec_context_fdname(const ExecContext *c, int fd_index);
 365
 366 bool exec_context_may_touch_console(const ExecContext *c);
 367 bool exec_context_maintains_privileges(const ExecContext *c);
 368
 369 int exec_context_get_effective_ioprio(const ExecContext *c);
 370
 371 void exec_context_free_log_extra_fields(ExecContext *c);
 372
 373 void exec_status_start(ExecStatus *s, pid_t pid);
 374 void exec_status_exit(ExecStatus *s, const ExecContext *context, pid_t pid, int code, int status);
 375 void exec_status_dump(const ExecStatus *s, FILE *f, const char *prefix);
 376
 377 int exec_runtime_acquire(Manager *m, const ExecContext *c, const char *name, bool create, ExecRuntime **ret);
 378 ExecRuntime *exec_runtime_unref(ExecRuntime *r, bool destroy);
 379
 380 int exec_runtime_serialize(const Manager *m, FILE *f, FDSet *fds);
 381 int exec_runtime_deserialize_compat(Unit *u, const char *key, const char *value, FDSet *fds);
 382 void exec_runtime_deserialize_one(Manager *m, const char *value, FDSet *fds);
 383 void exec_runtime_vacuum(Manager *m);
 384
 385 const char* exec_output_to_string(ExecOutput i) _const_;
 386 ExecOutput exec_output_from_string(const char *s) _pure_;
 387
 388 const char* exec_input_to_string(ExecInput i) _const_;
 389 ExecInput exec_input_from_string(const char *s) _pure_;
 390
 391 const char* exec_utmp_mode_to_string(ExecUtmpMode i) _const_;
 392 ExecUtmpMode exec_utmp_mode_from_string(const char *s) _pure_;
 393
 394 const char* exec_preserve_mode_to_string(ExecPreserveMode i) _const_;
 395 ExecPreserveMode exec_preserve_mode_from_string(const char *s) _pure_;
 396
 397 const char* exec_keyring_mode_to_string(ExecKeyringMode i) _const_;
 398 ExecKeyringMode exec_keyring_mode_from_string(const char *s) _pure_;
 399
 400 const char* exec_directory_type_to_string(ExecDirectoryType i) _const_;
 401 ExecDirectoryType exec_directory_type_from_string(const char *s) _pure_;