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