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 struct ExecStatus {
  76         dual_timestamp start_timestamp;
  77         dual_timestamp exit_timestamp;
  78         pid_t pid;
  79         int code;     /* as in siginfo_t::si_code */
  80         int status;   /* as in sigingo_t::si_status */
  81 };
  82
  83 struct ExecCommand {
  84         char *path;
  85         char **argv;
  86         ExecStatus exec_status;
  87         LIST_FIELDS(ExecCommand, command); /* useful for chaining commands */
  88         bool ignore:1;
  89         bool privileged:1;
  90 };
  91
  92 struct ExecRuntime {
  93         int n_ref;
  94
  95         char *tmp_dir;
  96         char *var_tmp_dir;
  97
  98         /* An AF_UNIX socket pair, that contains a datagram containing a file descriptor referring to the network
  99          * namespace. */
 100         int netns_storage_socket[2];
 101 };
 102
 103 struct ExecContext {
 104         char **environment;
 105         char **environment_files;
 106         char **pass_environment;
 107
 108         struct rlimit *rlimit[_RLIMIT_MAX];
 109         char *working_directory, *root_directory;
 110         bool working_directory_missing_ok;
 111         bool working_directory_home;
 112
 113         mode_t umask;
 114         int oom_score_adjust;
 115         int nice;
 116         int ioprio;
 117         int cpu_sched_policy;
 118         int cpu_sched_priority;
 119
 120         cpu_set_t *cpuset;
 121         unsigned cpuset_ncpus;
 122
 123         ExecInput std_input;
 124         ExecOutput std_output;
 125         ExecOutput std_error;
 126         char *stdio_fdname[3];
 127
 128         nsec_t timer_slack_nsec;
 129
 130         bool stdio_as_fds;
 131
 132         char *tty_path;
 133
 134         bool tty_reset;
 135         bool tty_vhangup;
 136         bool tty_vt_disallocate;
 137
 138         bool ignore_sigpipe;
 139
 140         /* Since resolving these names might involve socket
 141          * connections and we don't want to deadlock ourselves these
 142          * names are resolved on execution only and in the child
 143          * process. */
 144         char *user;
 145         char *group;
 146         char **supplementary_groups;
 147
 148         char *pam_name;
 149
 150         char *utmp_id;
 151         ExecUtmpMode utmp_mode;
 152
 153         bool selinux_context_ignore;
 154         char *selinux_context;
 155
 156         bool apparmor_profile_ignore;
 157         char *apparmor_profile;
 158
 159         bool smack_process_label_ignore;
 160         char *smack_process_label;
 161
 162         char **read_write_paths, **read_only_paths, **inaccessible_paths;
 163         unsigned long mount_flags;
 164         BindMount *bind_mounts;
 165         unsigned n_bind_mounts;
 166
 167         uint64_t capability_bounding_set;
 168         uint64_t capability_ambient_set;
 169         int secure_bits;
 170
 171         int syslog_priority;
 172         char *syslog_identifier;
 173         bool syslog_level_prefix;
 174
 175         bool cpu_sched_reset_on_fork;
 176         bool non_blocking;
 177         bool private_tmp;
 178         bool private_network;
 179         bool private_devices;
 180         bool private_users;
 181         ProtectSystem protect_system;
 182         ProtectHome protect_home;
 183         bool protect_kernel_tunables;
 184         bool protect_kernel_modules;
 185         bool protect_control_groups;
 186
 187         bool no_new_privileges;
 188
 189         bool dynamic_user;
 190         bool remove_ipc;
 191
 192         /* This is not exposed to the user but available
 193          * internally. We need it to make sure that whenever we spawn
 194          * /usr/bin/mount it is run in the same process group as us so
 195          * that the autofs logic detects that it belongs to us and we
 196          * don't enter a trigger loop. */
 197         bool same_pgrp;
 198
 199         unsigned long personality;
 200
 201         unsigned long restrict_namespaces; /* The CLONE_NEWxyz flags permitted to the unit's processes */
 202
 203         Set *syscall_filter;
 204         Set *syscall_archs;
 205         int syscall_errno;
 206         bool syscall_whitelist:1;
 207
 208         Set *address_families;
 209         bool address_families_whitelist:1;
 210
 211         char **runtime_directory;
 212         mode_t runtime_directory_mode;
 213
 214         bool memory_deny_write_execute;
 215         bool restrict_realtime;
 216
 217         bool oom_score_adjust_set:1;
 218         bool nice_set:1;
 219         bool ioprio_set:1;
 220         bool cpu_sched_set:1;
 221 };
 222
 223 static inline bool exec_context_restrict_namespaces_set(const ExecContext *c) {
 224         assert(c);
 225
 226         return (c->restrict_namespaces & NAMESPACE_FLAGS_ALL) != NAMESPACE_FLAGS_ALL;
 227 }
 228
 229 typedef enum ExecFlags {
 230         EXEC_APPLY_PERMISSIONS = 1U << 0,
 231         EXEC_APPLY_CHROOT      = 1U << 1,
 232         EXEC_APPLY_TTY_STDIN   = 1U << 2,
 233
 234         /* The following are not used by execute.c, but by consumers internally */
 235         EXEC_PASS_FDS          = 1U << 3,
 236         EXEC_IS_CONTROL        = 1U << 4,
 237         EXEC_SETENV_RESULT     = 1U << 5,
 238         EXEC_SET_WATCHDOG      = 1U << 6,
 239 } ExecFlags;
 240
 241 struct ExecParameters {
 242         char **argv;
 243         char **environment;
 244
 245         int *fds;
 246         char **fd_names;
 247         unsigned n_fds;
 248
 249         ExecFlags flags;
 250         bool selinux_context_net:1;
 251
 252         bool cgroup_delegate:1;
 253         CGroupMask cgroup_supported;
 254         const char *cgroup_path;
 255
 256         const char *runtime_prefix;
 257
 258         const char *confirm_spawn;
 259
 260         usec_t watchdog_usec;
 261
 262         int *idle_pipe;
 263
 264         int stdin_fd;
 265         int stdout_fd;
 266         int stderr_fd;
 267 };
 268
 269 #include "unit.h"
 270 #include "dynamic-user.h"
 271
 272 int exec_spawn(Unit *unit,
 273                ExecCommand *command,
 274                const ExecContext *context,
 275                const ExecParameters *exec_params,
 276                ExecRuntime *runtime,
 277                DynamicCreds *dynamic_creds,
 278                pid_t *ret);
 279
 280 void exec_command_done(ExecCommand *c);
 281 void exec_command_done_array(ExecCommand *c, unsigned n);
 282
 283 ExecCommand* exec_command_free_list(ExecCommand *c);
 284 void exec_command_free_array(ExecCommand **c, unsigned n);
 285
 286 char *exec_command_line(char **argv);
 287
 288 void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix);
 289 void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix);
 290 void exec_command_append_list(ExecCommand **l, ExecCommand *e);
 291 int exec_command_set(ExecCommand *c, const char *path, ...);
 292 int exec_command_append(ExecCommand *c, const char *path, ...);
 293
 294 void exec_context_init(ExecContext *c);
 295 void exec_context_done(ExecContext *c);
 296 void exec_context_dump(ExecContext *c, FILE* f, const char *prefix);
 297
 298 int exec_context_destroy_runtime_directory(ExecContext *c, const char *runtime_root);
 299
 300 int exec_context_load_environment(Unit *unit, const ExecContext *c, char ***l);
 301 int exec_context_named_iofds(Unit *unit, const ExecContext *c, const ExecParameters *p, int named_iofds[3]);
 302 const char* exec_context_fdname(const ExecContext *c, int fd_index);
 303
 304 bool exec_context_may_touch_console(ExecContext *c);
 305 bool exec_context_maintains_privileges(ExecContext *c);
 306
 307 void exec_status_start(ExecStatus *s, pid_t pid);
 308 void exec_status_exit(ExecStatus *s, ExecContext *context, pid_t pid, int code, int status);
 309 void exec_status_dump(ExecStatus *s, FILE *f, const char *prefix);
 310
 311 int exec_runtime_make(ExecRuntime **rt, ExecContext *c, const char *id);
 312 ExecRuntime *exec_runtime_ref(ExecRuntime *r);
 313 ExecRuntime *exec_runtime_unref(ExecRuntime *r);
 314
 315 int exec_runtime_serialize(Unit *unit, ExecRuntime *rt, FILE *f, FDSet *fds);
 316 int exec_runtime_deserialize_item(Unit *unit, ExecRuntime **rt, const char *key, const char *value, FDSet *fds);
 317
 318 void exec_runtime_destroy(ExecRuntime *rt);
 319
 320 const char* exec_output_to_string(ExecOutput i) _const_;
 321 ExecOutput exec_output_from_string(const char *s) _pure_;
 322
 323 const char* exec_input_to_string(ExecInput i) _const_;
 324 ExecInput exec_input_from_string(const char *s) _pure_;
 325
 326 const char* exec_utmp_mode_to_string(ExecUtmpMode i) _const_;
 327 ExecUtmpMode exec_utmp_mode_from_string(const char *s) _pure_;