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         int log_level_max;
 216
 217         struct iovec* log_extra_fields;
 218         size_t n_log_extra_fields;
 219
 220         bool cpu_sched_reset_on_fork;
 221         bool non_blocking;
 222         bool private_tmp;
 223         bool private_network;
 224         bool private_devices;
 225         bool private_users;
 226         ProtectSystem protect_system;
 227         ProtectHome protect_home;
 228         bool protect_kernel_tunables;
 229         bool protect_kernel_modules;
 230         bool protect_control_groups;
 231         bool mount_apivfs;
 232
 233         bool no_new_privileges;
 234
 235         bool dynamic_user;
 236         bool remove_ipc;
 237
 238         /* This is not exposed to the user but available
 239          * internally. We need it to make sure that whenever we spawn
 240          * /usr/bin/mount it is run in the same process group as us so
 241          * that the autofs logic detects that it belongs to us and we
 242          * don't enter a trigger loop. */
 243         bool same_pgrp;
 244
 245         unsigned long personality;
 246         bool lock_personality;
 247
 248         unsigned long restrict_namespaces; /* The CLONE_NEWxyz flags permitted to the unit's processes */
 249
 250         Hashmap *syscall_filter;
 251         Set *syscall_archs;
 252         int syscall_errno;
 253         bool syscall_whitelist:1;
 254
 255         Set *address_families;
 256         bool address_families_whitelist:1;
 257
 258         ExecPreserveMode runtime_directory_preserve_mode;
 259         ExecDirectory directories[_EXEC_DIRECTORY_TYPE_MAX];
 260
 261         bool memory_deny_write_execute;
 262         bool restrict_realtime;
 263
 264         bool oom_score_adjust_set:1;
 265         bool nice_set:1;
 266         bool ioprio_set:1;
 267         bool cpu_sched_set:1;
 268 };
 269
 270 static inline bool exec_context_restrict_namespaces_set(const ExecContext *c) {
 271         assert(c);
 272
 273         return (c->restrict_namespaces & NAMESPACE_FLAGS_ALL) != NAMESPACE_FLAGS_ALL;
 274 }
 275
 276 typedef enum ExecFlags {
 277         EXEC_APPLY_SANDBOXING  = 1U << 0,
 278         EXEC_APPLY_CHROOT      = 1U << 1,
 279         EXEC_APPLY_TTY_STDIN   = 1U << 2,
 280         EXEC_NEW_KEYRING       = 1U << 3,
 281         EXEC_PASS_LOG_UNIT     = 1U << 4, /* Whether to pass the unit name to the service's journal stream connection */
 282         EXEC_CHOWN_DIRECTORIES = 1U << 5, /* chown() the runtime/state/cache/log directories to the user we run as, under all conditions */
 283         EXEC_NSS_BYPASS_BUS    = 1U << 6, /* Set the SYSTEMD_NSS_BYPASS_BUS environment variable, to disable nss-systemd for dbus */
 284         EXEC_CGROUP_DELEGATE   = 1U << 7,
 285
 286         /* The following are not used by execute.c, but by consumers internally */
 287         EXEC_PASS_FDS          = 1U << 8,
 288         EXEC_IS_CONTROL        = 1U << 9,
 289         EXEC_SETENV_RESULT     = 1U << 10,
 290         EXEC_SET_WATCHDOG      = 1U << 11,
 291 } ExecFlags;
 292
 293 struct ExecParameters {
 294         char **argv;
 295         char **environment;
 296
 297         int *fds;
 298         char **fd_names;
 299         unsigned n_storage_fds;
 300         unsigned n_socket_fds;
 301
 302         ExecFlags flags;
 303         bool selinux_context_net:1;
 304
 305         CGroupMask cgroup_supported;
 306         const char *cgroup_path;
 307
 308         char **prefix;
 309
 310         const char *confirm_spawn;
 311
 312         usec_t watchdog_usec;
 313
 314         int *idle_pipe;
 315
 316         int stdin_fd;
 317         int stdout_fd;
 318         int stderr_fd;
 319 };
 320
 321 #include "unit.h"
 322 #include "dynamic-user.h"
 323
 324 int exec_spawn(Unit *unit,
 325                ExecCommand *command,
 326                const ExecContext *context,
 327                const ExecParameters *exec_params,
 328                ExecRuntime *runtime,
 329                DynamicCreds *dynamic_creds,
 330                pid_t *ret);
 331
 332 void exec_command_done(ExecCommand *c);
 333 void exec_command_done_array(ExecCommand *c, unsigned n);
 334
 335 ExecCommand* exec_command_free_list(ExecCommand *c);
 336 void exec_command_free_array(ExecCommand **c, unsigned n);
 337
 338 char *exec_command_line(char **argv);
 339
 340 void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix);
 341 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix);
 342 void exec_command_append_list(ExecCommand **l, ExecCommand *e);
 343 int exec_command_set(ExecCommand *c, const char *path, ...);
 344 int exec_command_append(ExecCommand *c, const char *path, ...);
 345
 346 void exec_context_init(ExecContext *c);
 347 void exec_context_done(ExecContext *c);
 348 void exec_context_dump(ExecContext *c, FILE* f, const char *prefix);
 349
 350 int exec_context_destroy_runtime_directory(ExecContext *c, const char *runtime_root);
 351
 352 int exec_context_load_environment(Unit *unit, const ExecContext *c, char ***l);
 353 int exec_context_named_iofds(Unit *unit, const ExecContext *c, const ExecParameters *p, int named_iofds[3]);
 354 const char* exec_context_fdname(const ExecContext *c, int fd_index);
 355
 356 bool exec_context_may_touch_console(ExecContext *c);
 357 bool exec_context_maintains_privileges(ExecContext *c);
 358
 359 int exec_context_get_effective_ioprio(ExecContext *c);
 360
 361 void exec_context_free_log_extra_fields(ExecContext *c);
 362
 363 void exec_status_start(ExecStatus *s, pid_t pid);
 364 void exec_status_exit(ExecStatus *s, ExecContext *context, pid_t pid, int code, int status);
 365 void exec_status_dump(ExecStatus *s, FILE *f, const char *prefix);
 366
 367 int exec_runtime_make(ExecRuntime **rt, ExecContext *c, const char *id);
 368 ExecRuntime *exec_runtime_ref(ExecRuntime *r);
 369 ExecRuntime *exec_runtime_unref(ExecRuntime *r);
 370
 371 int exec_runtime_serialize(Unit *unit, ExecRuntime *rt, FILE *f, FDSet *fds);
 372 int exec_runtime_deserialize_item(Unit *unit, ExecRuntime **rt, const char *key, const char *value, FDSet *fds);
 373
 374 void exec_runtime_destroy(ExecRuntime *rt);
 375
 376 const char* exec_output_to_string(ExecOutput i) _const_;
 377 ExecOutput exec_output_from_string(const char *s) _pure_;
 378
 379 const char* exec_input_to_string(ExecInput i) _const_;
 380 ExecInput exec_input_from_string(const char *s) _pure_;
 381
 382 const char* exec_utmp_mode_to_string(ExecUtmpMode i) _const_;
 383 ExecUtmpMode exec_utmp_mode_from_string(const char *s) _pure_;
 384
 385 const char* exec_preserve_mode_to_string(ExecPreserveMode i) _const_;
 386 ExecPreserveMode exec_preserve_mode_from_string(const char *s) _pure_;
 387
 388 const char* exec_keyring_mode_to_string(ExecKeyringMode i) _const_;
 389 ExecKeyringMode exec_keyring_mode_from_string(const char *s) _pure_;
 390
 391 const char* exec_directory_type_to_string(ExecDirectoryType i) _const_;
 392 ExecDirectoryType exec_directory_type_from_string(const char *s) _pure_;