src/core/execute.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 typedef struct ExecStatus ExecStatus;
   5 typedef struct ExecCommand ExecCommand;
   6 typedef struct ExecContext ExecContext;
   7 typedef struct ExecRuntime ExecRuntime;
   8 typedef struct ExecParameters ExecParameters;
   9 typedef struct Manager Manager;
  10
  11 #include <sched.h>
  12 #include <stdbool.h>
  13 #include <stdio.h>
  14 #include <sys/capability.h>
  15
  16 #include "cgroup-util.h"
  17 #include "fdset.h"
  18 #include "list.h"
  19 #include "missing.h"
  20 #include "namespace.h"
  21 #include "nsflags.h"
  22
  23 #define EXEC_STDIN_DATA_MAX (64U*1024U*1024U)
  24
  25 typedef enum ExecUtmpMode {
  26         EXEC_UTMP_INIT,
  27         EXEC_UTMP_LOGIN,
  28         EXEC_UTMP_USER,
  29         _EXEC_UTMP_MODE_MAX,
  30         _EXEC_UTMP_MODE_INVALID = -1
  31 } ExecUtmpMode;
  32
  33 typedef enum ExecInput {
  34         EXEC_INPUT_NULL,
  35         EXEC_INPUT_TTY,
  36         EXEC_INPUT_TTY_FORCE,
  37         EXEC_INPUT_TTY_FAIL,
  38         EXEC_INPUT_SOCKET,
  39         EXEC_INPUT_NAMED_FD,
  40         EXEC_INPUT_DATA,
  41         EXEC_INPUT_FILE,
  42         _EXEC_INPUT_MAX,
  43         _EXEC_INPUT_INVALID = -1
  44 } ExecInput;
  45
  46 typedef enum ExecOutput {
  47         EXEC_OUTPUT_INHERIT,
  48         EXEC_OUTPUT_NULL,
  49         EXEC_OUTPUT_TTY,
  50         EXEC_OUTPUT_SYSLOG,
  51         EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
  52         EXEC_OUTPUT_KMSG,
  53         EXEC_OUTPUT_KMSG_AND_CONSOLE,
  54         EXEC_OUTPUT_JOURNAL,
  55         EXEC_OUTPUT_JOURNAL_AND_CONSOLE,
  56         EXEC_OUTPUT_SOCKET,
  57         EXEC_OUTPUT_NAMED_FD,
  58         EXEC_OUTPUT_FILE,
  59         EXEC_OUTPUT_FILE_APPEND,
  60         _EXEC_OUTPUT_MAX,
  61         _EXEC_OUTPUT_INVALID = -1
  62 } ExecOutput;
  63
  64 typedef enum ExecPreserveMode {
  65         EXEC_PRESERVE_NO,
  66         EXEC_PRESERVE_YES,
  67         EXEC_PRESERVE_RESTART,
  68         _EXEC_PRESERVE_MODE_MAX,
  69         _EXEC_PRESERVE_MODE_INVALID = -1
  70 } ExecPreserveMode;
  71
  72 typedef enum ExecKeyringMode {
  73         EXEC_KEYRING_INHERIT,
  74         EXEC_KEYRING_PRIVATE,
  75         EXEC_KEYRING_SHARED,
  76         _EXEC_KEYRING_MODE_MAX,
  77         _EXEC_KEYRING_MODE_INVALID = -1,
  78 } ExecKeyringMode;
  79
  80 struct ExecStatus {
  81         dual_timestamp start_timestamp;
  82         dual_timestamp exit_timestamp;
  83         pid_t pid;
  84         int code;     /* as in siginfo_t::si_code */
  85         int status;   /* as in sigingo_t::si_status */
  86 };
  87
  88 typedef enum ExecCommandFlags {
  89         EXEC_COMMAND_IGNORE_FAILURE   = 1 << 0,
  90         EXEC_COMMAND_FULLY_PRIVILEGED = 1 << 1,
  91         EXEC_COMMAND_NO_SETUID        = 1 << 2,
  92         EXEC_COMMAND_AMBIENT_MAGIC    = 1 << 3,
  93 } ExecCommandFlags;
  94
  95 struct ExecCommand {
  96         char *path;
  97         char **argv;
  98         ExecStatus exec_status;
  99         ExecCommandFlags flags;
 100         LIST_FIELDS(ExecCommand, command); /* useful for chaining commands */
 101 };
 102
 103 struct ExecRuntime {
 104         int n_ref;
 105
 106         Manager *manager;
 107
 108         /* unit id of the owner */
 109         char *id;
 110
 111         char *tmp_dir;
 112         char *var_tmp_dir;
 113
 114         /* An AF_UNIX socket pair, that contains a datagram containing a file descriptor referring to the network
 115          * namespace. */
 116         int netns_storage_socket[2];
 117 };
 118
 119 typedef enum ExecDirectoryType {
 120         EXEC_DIRECTORY_RUNTIME = 0,
 121         EXEC_DIRECTORY_STATE,
 122         EXEC_DIRECTORY_CACHE,
 123         EXEC_DIRECTORY_LOGS,
 124         EXEC_DIRECTORY_CONFIGURATION,
 125         _EXEC_DIRECTORY_TYPE_MAX,
 126         _EXEC_DIRECTORY_TYPE_INVALID = -1,
 127 } ExecDirectoryType;
 128
 129 typedef struct ExecDirectory {
 130         char **paths;
 131         mode_t mode;
 132 } ExecDirectory;
 133
 134 struct ExecContext {
 135         char **environment;
 136         char **environment_files;
 137         char **pass_environment;
 138         char **unset_environment;
 139
 140         struct rlimit *rlimit[_RLIMIT_MAX];
 141         char *working_directory, *root_directory, *root_image;
 142         bool working_directory_missing_ok;
 143         bool working_directory_home;
 144
 145         mode_t umask;
 146         int oom_score_adjust;
 147         int nice;
 148         int ioprio;
 149         int cpu_sched_policy;
 150         int cpu_sched_priority;
 151
 152         cpu_set_t *cpuset;
 153         unsigned cpuset_ncpus;
 154
 155         ExecInput std_input;
 156         ExecOutput std_output;
 157         ExecOutput std_error;
 158         char *stdio_fdname[3];
 159         char *stdio_file[3];
 160
 161         void *stdin_data;
 162         size_t stdin_data_size;
 163
 164         nsec_t timer_slack_nsec;
 165
 166         bool stdio_as_fds;
 167
 168         char *tty_path;
 169
 170         bool tty_reset;
 171         bool tty_vhangup;
 172         bool tty_vt_disallocate;
 173
 174         bool ignore_sigpipe;
 175
 176         /* Since resolving these names might involve socket
 177          * connections and we don't want to deadlock ourselves these
 178          * names are resolved on execution only and in the child
 179          * process. */
 180         char *user;
 181         char *group;
 182         char **supplementary_groups;
 183
 184         char *pam_name;
 185
 186         char *utmp_id;
 187         ExecUtmpMode utmp_mode;
 188
 189         bool selinux_context_ignore;
 190         char *selinux_context;
 191
 192         bool apparmor_profile_ignore;
 193         char *apparmor_profile;
 194
 195         bool smack_process_label_ignore;
 196         char *smack_process_label;
 197
 198         ExecKeyringMode keyring_mode;
 199
 200         char **read_write_paths, **read_only_paths, **inaccessible_paths;
 201         unsigned long mount_flags;
 202         BindMount *bind_mounts;
 203         size_t n_bind_mounts;
 204         TemporaryFileSystem *temporary_filesystems;
 205         size_t n_temporary_filesystems;
 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         bool private_mounts;
 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  = 1 << 0,
 279         EXEC_APPLY_CHROOT      = 1 << 1,
 280         EXEC_APPLY_TTY_STDIN   = 1 << 2,
 281         EXEC_NEW_KEYRING       = 1 << 3,
 282         EXEC_PASS_LOG_UNIT     = 1 << 4, /* Whether to pass the unit name to the service's journal stream connection */
 283         EXEC_CHOWN_DIRECTORIES = 1 << 5, /* chown() the runtime/state/cache/log directories to the user we run as, under all conditions */
 284         EXEC_NSS_BYPASS_BUS    = 1 << 6, /* Set the SYSTEMD_NSS_BYPASS_BUS environment variable, to disable nss-systemd for dbus */
 285         EXEC_CGROUP_DELEGATE   = 1 << 7,
 286
 287         /* The following are not used by execute.c, but by consumers internally */
 288         EXEC_PASS_FDS          = 1 << 8,
 289         EXEC_IS_CONTROL        = 1 << 9,
 290         EXEC_SETENV_RESULT     = 1 << 10,
 291         EXEC_SET_WATCHDOG      = 1 << 11,
 292 } ExecFlags;
 293
 294 struct ExecParameters {
 295         char **argv;
 296         char **environment;
 297
 298         int *fds;
 299         char **fd_names;
 300         size_t n_socket_fds;
 301         size_t n_storage_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         /* An fd that is closed by the execve(), and thus will result in EOF when the execve() is done */
 322         int exec_fd;
 323 };
 324
 325 #include "unit.h"
 326 #include "dynamic-user.h"
 327
 328 int exec_spawn(Unit *unit,
 329                ExecCommand *command,
 330                const ExecContext *context,
 331                const ExecParameters *exec_params,
 332                ExecRuntime *runtime,
 333                DynamicCreds *dynamic_creds,
 334                pid_t *ret);
 335
 336 void exec_command_done_array(ExecCommand *c, size_t n);
 337
 338 ExecCommand* exec_command_free_list(ExecCommand *c);
 339 void exec_command_free_array(ExecCommand **c, size_t n);
 340
 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(const ExecContext *c, FILE* f, const char *prefix);
 349
 350 int exec_context_destroy_runtime_directory(const ExecContext *c, const char *runtime_root);
 351
 352 const char* exec_context_fdname(const ExecContext *c, int fd_index);
 353
 354 bool exec_context_may_touch_console(const ExecContext *c);
 355 bool exec_context_maintains_privileges(const ExecContext *c);
 356
 357 int exec_context_get_effective_ioprio(const ExecContext *c);
 358
 359 void exec_context_free_log_extra_fields(ExecContext *c);
 360
 361 void exec_status_start(ExecStatus *s, pid_t pid);
 362 void exec_status_exit(ExecStatus *s, const ExecContext *context, pid_t pid, int code, int status);
 363 void exec_status_dump(const ExecStatus *s, FILE *f, const char *prefix);
 364
 365 int exec_runtime_acquire(Manager *m, const ExecContext *c, const char *name, bool create, ExecRuntime **ret);
 366 ExecRuntime *exec_runtime_unref(ExecRuntime *r, bool destroy);
 367
 368 int exec_runtime_serialize(const Manager *m, FILE *f, FDSet *fds);
 369 int exec_runtime_deserialize_compat(Unit *u, const char *key, const char *value, FDSet *fds);
 370 void exec_runtime_deserialize_one(Manager *m, const char *value, FDSet *fds);
 371 void exec_runtime_vacuum(Manager *m);
 372
 373 const char* exec_output_to_string(ExecOutput i) _const_;
 374 ExecOutput exec_output_from_string(const char *s) _pure_;
 375
 376 const char* exec_input_to_string(ExecInput i) _const_;
 377 ExecInput exec_input_from_string(const char *s) _pure_;
 378
 379 const char* exec_utmp_mode_to_string(ExecUtmpMode i) _const_;
 380 ExecUtmpMode exec_utmp_mode_from_string(const char *s) _pure_;
 381
 382 const char* exec_preserve_mode_to_string(ExecPreserveMode i) _const_;
 383 ExecPreserveMode exec_preserve_mode_from_string(const char *s) _pure_;
 384
 385 const char* exec_keyring_mode_to_string(ExecKeyringMode i) _const_;
 386 ExecKeyringMode exec_keyring_mode_from_string(const char *s) _pure_;
 387
 388 const char* exec_directory_type_to_string(ExecDirectoryType i) _const_;
 389 ExecDirectoryType exec_directory_type_from_string(const char *s) _pure_;