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 struct ExecStatus {
  84         dual_timestamp start_timestamp;
  85         dual_timestamp exit_timestamp;
  86         pid_t pid;
  87         int code;     /* as in siginfo_t::si_code */
  88         int status;   /* as in sigingo_t::si_status */
  89 };
  90
  91 typedef enum ExecCommandFlags {
  92         EXEC_COMMAND_IGNORE_FAILURE = 1,
  93         EXEC_COMMAND_FULLY_PRIVILEGED = 2,
  94         EXEC_COMMAND_NO_SETUID = 4,
  95         EXEC_COMMAND_AMBIENT_MAGIC = 8,
  96 } ExecCommandFlags;
  97
  98 struct ExecCommand {
  99         char *path;
 100         char **argv;
 101         ExecStatus exec_status;
 102         ExecCommandFlags flags;
 103         LIST_FIELDS(ExecCommand, command); /* useful for chaining commands */
 104 };
 105
 106 struct ExecRuntime {
 107         int n_ref;
 108
 109         char *tmp_dir;
 110         char *var_tmp_dir;
 111
 112         /* An AF_UNIX socket pair, that contains a datagram containing a file descriptor referring to the network
 113          * namespace. */
 114         int netns_storage_socket[2];
 115 };
 116
 117 typedef enum ExecDirectoryType {
 118         EXEC_DIRECTORY_RUNTIME = 0,
 119         EXEC_DIRECTORY_STATE,
 120         EXEC_DIRECTORY_CACHE,
 121         EXEC_DIRECTORY_LOGS,
 122         EXEC_DIRECTORY_CONFIGURATION,
 123         _EXEC_DIRECTORY_MAX,
 124         _EXEC_DIRECTORY_INVALID = -1,
 125 } ExecDirectoryType;
 126
 127 typedef struct ExecDirectory {
 128         char **paths;
 129         mode_t mode;
 130 } ExecDirectory;
 131
 132 struct ExecContext {
 133         char **environment;
 134         char **environment_files;
 135         char **pass_environment;
 136         char **unset_environment;
 137
 138         struct rlimit *rlimit[_RLIMIT_MAX];
 139         char *working_directory, *root_directory, *root_image;
 140         bool working_directory_missing_ok;
 141         bool working_directory_home;
 142
 143         mode_t umask;
 144         int oom_score_adjust;
 145         int nice;
 146         int ioprio;
 147         int cpu_sched_policy;
 148         int cpu_sched_priority;
 149
 150         cpu_set_t *cpuset;
 151         unsigned cpuset_ncpus;
 152
 153         ExecInput std_input;
 154         ExecOutput std_output;
 155         ExecOutput std_error;
 156         char *stdio_fdname[3];
 157
 158         nsec_t timer_slack_nsec;
 159
 160         bool stdio_as_fds;
 161
 162         char *tty_path;
 163
 164         bool tty_reset;
 165         bool tty_vhangup;
 166         bool tty_vt_disallocate;
 167
 168         bool ignore_sigpipe;
 169
 170         /* Since resolving these names might involve socket
 171          * connections and we don't want to deadlock ourselves these
 172          * names are resolved on execution only and in the child
 173          * process. */
 174         char *user;
 175         char *group;
 176         char **supplementary_groups;
 177
 178         char *pam_name;
 179
 180         char *utmp_id;
 181         ExecUtmpMode utmp_mode;
 182
 183         bool selinux_context_ignore;
 184         char *selinux_context;
 185
 186         bool apparmor_profile_ignore;
 187         char *apparmor_profile;
 188
 189         bool smack_process_label_ignore;
 190         char *smack_process_label;
 191
 192         char **read_write_paths, **read_only_paths, **inaccessible_paths;
 193         unsigned long mount_flags;
 194         BindMount *bind_mounts;
 195         unsigned n_bind_mounts;
 196
 197         uint64_t capability_bounding_set;
 198         uint64_t capability_ambient_set;
 199         int secure_bits;
 200
 201         int syslog_priority;
 202         char *syslog_identifier;
 203         bool syslog_level_prefix;
 204
 205         bool cpu_sched_reset_on_fork;
 206         bool non_blocking;
 207         bool private_tmp;
 208         bool private_network;
 209         bool private_devices;
 210         bool private_users;
 211         ProtectSystem protect_system;
 212         ProtectHome protect_home;
 213         bool protect_kernel_tunables;
 214         bool protect_kernel_modules;
 215         bool protect_control_groups;
 216         bool mount_apivfs;
 217
 218         bool no_new_privileges;
 219
 220         bool dynamic_user;
 221         bool remove_ipc;
 222
 223         /* This is not exposed to the user but available
 224          * internally. We need it to make sure that whenever we spawn
 225          * /usr/bin/mount it is run in the same process group as us so
 226          * that the autofs logic detects that it belongs to us and we
 227          * don't enter a trigger loop. */
 228         bool same_pgrp;
 229
 230         unsigned long personality;
 231         bool lock_personality;
 232
 233         unsigned long restrict_namespaces; /* The CLONE_NEWxyz flags permitted to the unit's processes */
 234
 235         Set *syscall_filter;
 236         Set *syscall_archs;
 237         int syscall_errno;
 238         bool syscall_whitelist:1;
 239
 240         Set *address_families;
 241         bool address_families_whitelist:1;
 242
 243         ExecPreserveMode runtime_directory_preserve_mode;
 244         ExecDirectory directories[_EXEC_DIRECTORY_MAX];
 245
 246         bool memory_deny_write_execute;
 247         bool restrict_realtime;
 248
 249         bool oom_score_adjust_set:1;
 250         bool nice_set:1;
 251         bool ioprio_set:1;
 252         bool cpu_sched_set:1;
 253 };
 254
 255 static inline bool exec_context_restrict_namespaces_set(const ExecContext *c) {
 256         assert(c);
 257
 258         return (c->restrict_namespaces & NAMESPACE_FLAGS_ALL) != NAMESPACE_FLAGS_ALL;
 259 }
 260
 261 typedef enum ExecFlags {
 262         EXEC_APPLY_SANDBOXING  = 1U << 0,
 263         EXEC_APPLY_CHROOT      = 1U << 1,
 264         EXEC_APPLY_TTY_STDIN   = 1U << 2,
 265         EXEC_NEW_KEYRING       = 1U << 3,
 266         EXEC_PASS_LOG_UNIT     = 1U << 4, /* Whether to pass the unit name to the service's journal stream connection */
 267         EXEC_CHOWN_DIRECTORIES = 1U << 5, /* chown() the runtime/state/cache/log directories to the user we run as, under all conditions */
 268         EXEC_NSS_BYPASS_BUS    = 1U << 6, /* Set the SYSTEMD_NSS_BYPASS_BUS environment variable, to disable nss-systemd for dbus */
 269         EXEC_CGROUP_DELEGATE   = 1U << 7,
 270
 271         /* The following are not used by execute.c, but by consumers internally */
 272         EXEC_PASS_FDS          = 1U << 8,
 273         EXEC_IS_CONTROL        = 1U << 9,
 274         EXEC_SETENV_RESULT     = 1U << 10,
 275         EXEC_SET_WATCHDOG      = 1U << 11,
 276 } ExecFlags;
 277
 278 struct ExecParameters {
 279         char **argv;
 280         char **environment;
 281
 282         int *fds;
 283         char **fd_names;
 284         unsigned n_storage_fds;
 285         unsigned n_socket_fds;
 286
 287         ExecFlags flags;
 288         bool selinux_context_net:1;
 289
 290         CGroupMask cgroup_supported;
 291         const char *cgroup_path;
 292
 293         char **prefix;
 294
 295         const char *confirm_spawn;
 296
 297         usec_t watchdog_usec;
 298
 299         int *idle_pipe;
 300
 301         int stdin_fd;
 302         int stdout_fd;
 303         int stderr_fd;
 304 };
 305
 306 #include "unit.h"
 307 #include "dynamic-user.h"
 308
 309 int exec_spawn(Unit *unit,
 310                ExecCommand *command,
 311                const ExecContext *context,
 312                const ExecParameters *exec_params,
 313                ExecRuntime *runtime,
 314                DynamicCreds *dynamic_creds,
 315                pid_t *ret);
 316
 317 void exec_command_done(ExecCommand *c);
 318 void exec_command_done_array(ExecCommand *c, unsigned n);
 319
 320 ExecCommand* exec_command_free_list(ExecCommand *c);
 321 void exec_command_free_array(ExecCommand **c, unsigned n);
 322
 323 char *exec_command_line(char **argv);
 324
 325 void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix);
 326 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix);
 327 void exec_command_append_list(ExecCommand **l, ExecCommand *e);
 328 int exec_command_set(ExecCommand *c, const char *path, ...);
 329 int exec_command_append(ExecCommand *c, const char *path, ...);
 330
 331 void exec_context_init(ExecContext *c);
 332 void exec_context_done(ExecContext *c);
 333 void exec_context_dump(ExecContext *c, FILE* f, const char *prefix);
 334
 335 int exec_context_destroy_runtime_directory(ExecContext *c, const char *runtime_root);
 336
 337 int exec_context_load_environment(Unit *unit, const ExecContext *c, char ***l);
 338 int exec_context_named_iofds(Unit *unit, const ExecContext *c, const ExecParameters *p, int named_iofds[3]);
 339 const char* exec_context_fdname(const ExecContext *c, int fd_index);
 340
 341 bool exec_context_may_touch_console(ExecContext *c);
 342 bool exec_context_maintains_privileges(ExecContext *c);
 343
 344 int exec_context_get_effective_ioprio(ExecContext *c);
 345
 346 void exec_status_start(ExecStatus *s, pid_t pid);
 347 void exec_status_exit(ExecStatus *s, ExecContext *context, pid_t pid, int code, int status);
 348 void exec_status_dump(ExecStatus *s, FILE *f, const char *prefix);
 349
 350 int exec_runtime_make(ExecRuntime **rt, ExecContext *c, const char *id);
 351 ExecRuntime *exec_runtime_ref(ExecRuntime *r);
 352 ExecRuntime *exec_runtime_unref(ExecRuntime *r);
 353
 354 int exec_runtime_serialize(Unit *unit, ExecRuntime *rt, FILE *f, FDSet *fds);
 355 int exec_runtime_deserialize_item(Unit *unit, ExecRuntime **rt, const char *key, const char *value, FDSet *fds);
 356
 357 void exec_runtime_destroy(ExecRuntime *rt);
 358
 359 const char* exec_output_to_string(ExecOutput i) _const_;
 360 ExecOutput exec_output_from_string(const char *s) _pure_;
 361
 362 const char* exec_input_to_string(ExecInput i) _const_;
 363 ExecInput exec_input_from_string(const char *s) _pure_;
 364
 365 const char* exec_utmp_mode_to_string(ExecUtmpMode i) _const_;
 366 ExecUtmpMode exec_utmp_mode_from_string(const char *s) _pure_;
 367
 368 const char* exec_preserve_mode_to_string(ExecPreserveMode i) _const_;
 369 ExecPreserveMode exec_preserve_mode_from_string(const char *s) _pure_;
 370
 371 const char* exec_directory_type_to_string(ExecDirectoryType i) _const_;
 372 ExecDirectoryType exec_directory_type_from_string(const char *s) _pure_;