src/core/execute.h

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