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