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         bool lock_personality;
 231
 232         unsigned long restrict_namespaces; /* The CLONE_NEWxyz flags permitted to the unit's processes */
 233
 234         Set *syscall_filter;
 235         Set *syscall_archs;
 236         int syscall_errno;
 237         bool syscall_whitelist:1;
 238
 239         Set *address_families;
 240         bool address_families_whitelist:1;
 241
 242         ExecPreserveMode runtime_directory_preserve_mode;
 243         ExecDirectory directories[_EXEC_DIRECTORY_MAX];
 244
 245         bool memory_deny_write_execute;
 246         bool restrict_realtime;
 247
 248         bool oom_score_adjust_set:1;
 249         bool nice_set:1;
 250         bool ioprio_set:1;
 251         bool cpu_sched_set:1;
 252 };
 253
 254 static inline bool exec_context_restrict_namespaces_set(const ExecContext *c) {
 255         assert(c);
 256
 257         return (c->restrict_namespaces & NAMESPACE_FLAGS_ALL) != NAMESPACE_FLAGS_ALL;
 258 }
 259
 260 typedef enum ExecFlags {
 261         EXEC_APPLY_SANDBOXING  = 1U << 0,
 262         EXEC_APPLY_CHROOT      = 1U << 1,
 263         EXEC_APPLY_TTY_STDIN   = 1U << 2,
 264         EXEC_NEW_KEYRING       = 1U << 3,
 265         EXEC_PASS_LOG_UNIT     = 1U << 4, /* Whether to pass the unit name to the service's journal stream connection */
 266         EXEC_CHOWN_DIRECTORIES = 1U << 5, /* chown() the runtime/state/cache/log directories to the user we run as, under all conditions */
 267         EXEC_NSS_BYPASS_BUS    = 1U << 6, /* Set the SYSTEMD_NSS_BYPASS_BUS environment variable, to disable nss-systemd for dbus */
 268         EXEC_CGROUP_DELEGATE   = 1U << 7,
 269
 270         /* The following are not used by execute.c, but by consumers internally */
 271         EXEC_PASS_FDS          = 1U << 8,
 272         EXEC_IS_CONTROL        = 1U << 9,
 273         EXEC_SETENV_RESULT     = 1U << 10,
 274         EXEC_SET_WATCHDOG      = 1U << 11,
 275 } ExecFlags;
 276
 277 struct ExecParameters {
 278         char **argv;
 279         char **environment;
 280
 281         int *fds;
 282         char **fd_names;
 283         unsigned n_storage_fds;
 284         unsigned n_socket_fds;
 285
 286         ExecFlags flags;
 287         bool selinux_context_net:1;
 288
 289         CGroupMask cgroup_supported;
 290         const char *cgroup_path;
 291
 292         char **prefix;
 293
 294         const char *confirm_spawn;
 295
 296         usec_t watchdog_usec;
 297
 298         int *idle_pipe;
 299
 300         int stdin_fd;
 301         int stdout_fd;
 302         int stderr_fd;
 303 };
 304
 305 #include "unit.h"
 306 #include "dynamic-user.h"
 307
 308 int exec_spawn(Unit *unit,
 309                ExecCommand *command,
 310                const ExecContext *context,
 311                const ExecParameters *exec_params,
 312                ExecRuntime *runtime,
 313                DynamicCreds *dynamic_creds,
 314                pid_t *ret);
 315
 316 void exec_command_done(ExecCommand *c);
 317 void exec_command_done_array(ExecCommand *c, unsigned n);
 318
 319 ExecCommand* exec_command_free_list(ExecCommand *c);
 320 void exec_command_free_array(ExecCommand **c, unsigned n);
 321
 322 char *exec_command_line(char **argv);
 323
 324 void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix);
 325 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix);
 326 void exec_command_append_list(ExecCommand **l, ExecCommand *e);
 327 int exec_command_set(ExecCommand *c, const char *path, ...);
 328 int exec_command_append(ExecCommand *c, const char *path, ...);
 329
 330 void exec_context_init(ExecContext *c);
 331 void exec_context_done(ExecContext *c);
 332 void exec_context_dump(ExecContext *c, FILE* f, const char *prefix);
 333
 334 int exec_context_destroy_runtime_directory(ExecContext *c, const char *runtime_root);
 335
 336 int exec_context_load_environment(Unit *unit, const ExecContext *c, char ***l);
 337 int exec_context_named_iofds(Unit *unit, const ExecContext *c, const ExecParameters *p, int named_iofds[3]);
 338 const char* exec_context_fdname(const ExecContext *c, int fd_index);
 339
 340 bool exec_context_may_touch_console(ExecContext *c);
 341 bool exec_context_maintains_privileges(ExecContext *c);
 342
 343 int exec_context_get_effective_ioprio(ExecContext *c);
 344
 345 void exec_status_start(ExecStatus *s, pid_t pid);
 346 void exec_status_exit(ExecStatus *s, ExecContext *context, pid_t pid, int code, int status);
 347 void exec_status_dump(ExecStatus *s, FILE *f, const char *prefix);
 348
 349 int exec_runtime_make(ExecRuntime **rt, ExecContext *c, const char *id);
 350 ExecRuntime *exec_runtime_ref(ExecRuntime *r);
 351 ExecRuntime *exec_runtime_unref(ExecRuntime *r);
 352
 353 int exec_runtime_serialize(Unit *unit, ExecRuntime *rt, FILE *f, FDSet *fds);
 354 int exec_runtime_deserialize_item(Unit *unit, ExecRuntime **rt, const char *key, const char *value, FDSet *fds);
 355
 356 void exec_runtime_destroy(ExecRuntime *rt);
 357
 358 const char* exec_output_to_string(ExecOutput i) _const_;
 359 ExecOutput exec_output_from_string(const char *s) _pure_;
 360
 361 const char* exec_input_to_string(ExecInput i) _const_;
 362 ExecInput exec_input_from_string(const char *s) _pure_;
 363
 364 const char* exec_utmp_mode_to_string(ExecUtmpMode i) _const_;
 365 ExecUtmpMode exec_utmp_mode_from_string(const char *s) _pure_;
 366
 367 const char* exec_preserve_mode_to_string(ExecPreserveMode i) _const_;
 368 ExecPreserveMode exec_preserve_mode_from_string(const char *s) _pure_;
 369
 370 const char* exec_directory_type_to_string(ExecDirectoryType i) _const_;
 371 ExecDirectoryType exec_directory_type_from_string(const char *s) _pure_;