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         TemporaryFileSystem *temporary_filesystems;
 223         unsigned n_temporary_filesystems;
 224
 225         uint64_t capability_bounding_set;
 226         uint64_t capability_ambient_set;
 227         int secure_bits;
 228
 229         int syslog_priority;
 230         char *syslog_identifier;
 231         bool syslog_level_prefix;
 232
 233         int log_level_max;
 234
 235         struct iovec* log_extra_fields;
 236         size_t n_log_extra_fields;
 237
 238         bool cpu_sched_reset_on_fork;
 239         bool non_blocking;
 240         bool private_tmp;
 241         bool private_network;
 242         bool private_devices;
 243         bool private_users;
 244         ProtectSystem protect_system;
 245         ProtectHome protect_home;
 246         bool protect_kernel_tunables;
 247         bool protect_kernel_modules;
 248         bool protect_control_groups;
 249         bool mount_apivfs;
 250
 251         bool no_new_privileges;
 252
 253         bool dynamic_user;
 254         bool remove_ipc;
 255
 256         /* This is not exposed to the user but available
 257          * internally. We need it to make sure that whenever we spawn
 258          * /usr/bin/mount it is run in the same process group as us so
 259          * that the autofs logic detects that it belongs to us and we
 260          * don't enter a trigger loop. */
 261         bool same_pgrp;
 262
 263         unsigned long personality;
 264         bool lock_personality;
 265
 266         unsigned long restrict_namespaces; /* The CLONE_NEWxyz flags permitted to the unit's processes */
 267
 268         Hashmap *syscall_filter;
 269         Set *syscall_archs;
 270         int syscall_errno;
 271         bool syscall_whitelist:1;
 272
 273         Set *address_families;
 274         bool address_families_whitelist:1;
 275
 276         ExecPreserveMode runtime_directory_preserve_mode;
 277         ExecDirectory directories[_EXEC_DIRECTORY_TYPE_MAX];
 278
 279         bool memory_deny_write_execute;
 280         bool restrict_realtime;
 281
 282         bool oom_score_adjust_set:1;
 283         bool nice_set:1;
 284         bool ioprio_set:1;
 285         bool cpu_sched_set:1;
 286 };
 287
 288 static inline bool exec_context_restrict_namespaces_set(const ExecContext *c) {
 289         assert(c);
 290
 291         return (c->restrict_namespaces & NAMESPACE_FLAGS_ALL) != NAMESPACE_FLAGS_ALL;
 292 }
 293
 294 typedef enum ExecFlags {
 295         EXEC_APPLY_SANDBOXING  = 1U << 0,
 296         EXEC_APPLY_CHROOT      = 1U << 1,
 297         EXEC_APPLY_TTY_STDIN   = 1U << 2,
 298         EXEC_NEW_KEYRING       = 1U << 3,
 299         EXEC_PASS_LOG_UNIT     = 1U << 4, /* Whether to pass the unit name to the service's journal stream connection */
 300         EXEC_CHOWN_DIRECTORIES = 1U << 5, /* chown() the runtime/state/cache/log directories to the user we run as, under all conditions */
 301         EXEC_NSS_BYPASS_BUS    = 1U << 6, /* Set the SYSTEMD_NSS_BYPASS_BUS environment variable, to disable nss-systemd for dbus */
 302         EXEC_CGROUP_DELEGATE   = 1U << 7,
 303
 304         /* The following are not used by execute.c, but by consumers internally */
 305         EXEC_PASS_FDS          = 1U << 8,
 306         EXEC_IS_CONTROL        = 1U << 9,
 307         EXEC_SETENV_RESULT     = 1U << 10,
 308         EXEC_SET_WATCHDOG      = 1U << 11,
 309 } ExecFlags;
 310
 311 struct ExecParameters {
 312         char **argv;
 313         char **environment;
 314
 315         int *fds;
 316         char **fd_names;
 317         unsigned n_storage_fds;
 318         unsigned n_socket_fds;
 319
 320         ExecFlags flags;
 321         bool selinux_context_net:1;
 322
 323         CGroupMask cgroup_supported;
 324         const char *cgroup_path;
 325
 326         char **prefix;
 327
 328         const char *confirm_spawn;
 329
 330         usec_t watchdog_usec;
 331
 332         int *idle_pipe;
 333
 334         int stdin_fd;
 335         int stdout_fd;
 336         int stderr_fd;
 337 };
 338
 339 #include "unit.h"
 340 #include "dynamic-user.h"
 341
 342 int exec_spawn(Unit *unit,
 343                ExecCommand *command,
 344                const ExecContext *context,
 345                const ExecParameters *exec_params,
 346                ExecRuntime *runtime,
 347                DynamicCreds *dynamic_creds,
 348                pid_t *ret);
 349
 350 void exec_command_done_array(ExecCommand *c, unsigned n);
 351
 352 ExecCommand* exec_command_free_list(ExecCommand *c);
 353 void exec_command_free_array(ExecCommand **c, unsigned n);
 354
 355 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix);
 356 void exec_command_append_list(ExecCommand **l, ExecCommand *e);
 357 int exec_command_set(ExecCommand *c, const char *path, ...);
 358 int exec_command_append(ExecCommand *c, const char *path, ...);
 359
 360 void exec_context_init(ExecContext *c);
 361 void exec_context_done(ExecContext *c);
 362 void exec_context_dump(const ExecContext *c, FILE* f, const char *prefix);
 363
 364 int exec_context_destroy_runtime_directory(const ExecContext *c, const char *runtime_root);
 365
 366 const char* exec_context_fdname(const ExecContext *c, int fd_index);
 367
 368 bool exec_context_may_touch_console(const ExecContext *c);
 369 bool exec_context_maintains_privileges(const ExecContext *c);
 370
 371 int exec_context_get_effective_ioprio(const ExecContext *c);
 372
 373 void exec_context_free_log_extra_fields(ExecContext *c);
 374
 375 void exec_status_start(ExecStatus *s, pid_t pid);
 376 void exec_status_exit(ExecStatus *s, const ExecContext *context, pid_t pid, int code, int status);
 377 void exec_status_dump(const ExecStatus *s, FILE *f, const char *prefix);
 378
 379 int exec_runtime_acquire(Manager *m, const ExecContext *c, const char *name, bool create, ExecRuntime **ret);
 380 ExecRuntime *exec_runtime_unref(ExecRuntime *r, bool destroy);
 381
 382 int exec_runtime_serialize(const Manager *m, FILE *f, FDSet *fds);
 383 int exec_runtime_deserialize_compat(Unit *u, const char *key, const char *value, FDSet *fds);
 384 void exec_runtime_deserialize_one(Manager *m, const char *value, FDSet *fds);
 385 void exec_runtime_vacuum(Manager *m);
 386
 387 const char* exec_output_to_string(ExecOutput i) _const_;
 388 ExecOutput exec_output_from_string(const char *s) _pure_;
 389
 390 const char* exec_input_to_string(ExecInput i) _const_;
 391 ExecInput exec_input_from_string(const char *s) _pure_;
 392
 393 const char* exec_utmp_mode_to_string(ExecUtmpMode i) _const_;
 394 ExecUtmpMode exec_utmp_mode_from_string(const char *s) _pure_;
 395
 396 const char* exec_preserve_mode_to_string(ExecPreserveMode i) _const_;
 397 ExecPreserveMode exec_preserve_mode_from_string(const char *s) _pure_;
 398
 399 const char* exec_keyring_mode_to_string(ExecKeyringMode i) _const_;
 400 ExecKeyringMode exec_keyring_mode_from_string(const char *s) _pure_;
 401
 402 const char* exec_directory_type_to_string(ExecDirectoryType i) _const_;
 403 ExecDirectoryType exec_directory_type_from_string(const char *s) _pure_;