systemd/src/core/execute.h

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

#pragma once

/***
  This file is part of systemd.

  Copyright 2010 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

typedef struct ExecStatus ExecStatus;
typedef struct ExecCommand ExecCommand;
typedef struct ExecContext ExecContext;
typedef struct ExecRuntime ExecRuntime;

#include <linux/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/capability.h>
#include <stdbool.h>
#include <stdio.h>
#include <sched.h>
#ifdef HAVE_SECCOMP
#include <seccomp.h>

#include "set.h"
#endif

#include "list.h"
#include "util.h"
#include "fdset.h"

typedef enum ExecInput {
        EXEC_INPUT_NULL,
        EXEC_INPUT_TTY,
        EXEC_INPUT_TTY_FORCE,
        EXEC_INPUT_TTY_FAIL,
        EXEC_INPUT_SOCKET,
        _EXEC_INPUT_MAX,
        _EXEC_INPUT_INVALID = -1
} ExecInput;

typedef enum ExecOutput {
        EXEC_OUTPUT_INHERIT,
        EXEC_OUTPUT_NULL,
        EXEC_OUTPUT_TTY,
        EXEC_OUTPUT_SYSLOG,
        EXEC_OUTPUT_SYSLOG_AND_CONSOLE,
        EXEC_OUTPUT_KMSG,
        EXEC_OUTPUT_KMSG_AND_CONSOLE,
        EXEC_OUTPUT_JOURNAL,
        EXEC_OUTPUT_JOURNAL_AND_CONSOLE,
        EXEC_OUTPUT_SOCKET,
        _EXEC_OUTPUT_MAX,
        _EXEC_OUTPUT_INVALID = -1
} ExecOutput;

struct ExecStatus {
        dual_timestamp start_timestamp;
        dual_timestamp exit_timestamp;
        pid_t pid;
        int code;     /* as in siginfo_t::si_code */
        int status;   /* as in sigingo_t::si_status */
};

struct ExecCommand {
        char *path;
        char **argv;
        ExecStatus exec_status;
        LIST_FIELDS(ExecCommand, command); /* useful for chaining commands */
        bool ignore;
};

struct ExecRuntime {
        int n_ref;

        char *tmp_dir;
        char *var_tmp_dir;

        int netns_storage_socket[2];
};

struct ExecContext {
        char **environment;
        char **environment_files;

        struct rlimit *rlimit[RLIMIT_NLIMITS];
        char *working_directory, *root_directory;

        mode_t umask;
        int oom_score_adjust;
        int nice;
        int ioprio;
        int cpu_sched_policy;
        int cpu_sched_priority;

        cpu_set_t *cpuset;
        unsigned cpuset_ncpus;

        ExecInput std_input;
        ExecOutput std_output;
        ExecOutput std_error;

        nsec_t timer_slack_nsec;

        char *tcpwrap_name;

        char *tty_path;

        bool tty_reset;
        bool tty_vhangup;
        bool tty_vt_disallocate;

        bool ignore_sigpipe;

        /* Since resolving these names might might involve socket
         * connections and we don't want to deadlock ourselves these
         * names are resolved on execution only and in the child
         * process. */
        char *user;
        char *group;
        char **supplementary_groups;

        char *pam_name;

        char *utmp_id;

        bool selinux_context_ignore;
        char *selinux_context;

        char **read_write_dirs, **read_only_dirs, **inaccessible_dirs;
        unsigned long mount_flags;

        uint64_t capability_bounding_set_drop;

        cap_t capabilities;
        int secure_bits;

        int syslog_priority;
        char *syslog_identifier;
        bool syslog_level_prefix;

        bool cpu_sched_reset_on_fork;
        bool non_blocking;
        bool private_tmp;
        bool private_network;
        bool private_devices;

        bool no_new_privileges;

        /* This is not exposed to the user but available
         * internally. We need it to make sure that whenever we spawn
         * /bin/mount it is run in the same process group as us so
         * that the autofs logic detects that it belongs to us and we
         * don't enter a trigger loop. */
        bool same_pgrp;

        unsigned long personality;

        Set *syscall_filter;
        Set *syscall_archs;
        int syscall_errno;
        bool syscall_whitelist:1;

        bool oom_score_adjust_set:1;
        bool nice_set:1;
        bool ioprio_set:1;
        bool cpu_sched_set:1;
};

#include "cgroup.h"

int exec_spawn(ExecCommand *command,
               char **argv,
               ExecContext *context,
               int fds[], unsigned n_fds,
               char **environment,
               bool apply_permissions,
               bool apply_chroot,
               bool apply_tty_stdin,
               bool confirm_spawn,
               CGroupControllerMask cgroup_mask,
               const char *cgroup_path,
               const char *unit_id,
               usec_t watchdog_usec,
               int pipe_fd[2],
               ExecRuntime *runtime,
               pid_t *ret);

void exec_command_done(ExecCommand *c);
void exec_command_done_array(ExecCommand *c, unsigned n);

void exec_command_free_list(ExecCommand *c);
void exec_command_free_array(ExecCommand **c, unsigned n);

char *exec_command_line(char **argv);

void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix);
void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix);
void exec_command_append_list(ExecCommand **l, ExecCommand *e);
int exec_command_set(ExecCommand *c, const char *path, ...);

void exec_context_init(ExecContext *c);
void exec_context_done(ExecContext *c);
void exec_context_dump(ExecContext *c, FILE* f, const char *prefix);

int exec_context_load_environment(const ExecContext *c, char ***l);

bool exec_context_may_touch_console(ExecContext *c);

void exec_status_start(ExecStatus *s, pid_t pid);
void exec_status_exit(ExecStatus *s, ExecContext *context, pid_t pid, int code, int status);
void exec_status_dump(ExecStatus *s, FILE *f, const char *prefix);

int exec_runtime_make(ExecRuntime **rt, ExecContext *c, const char *id);
ExecRuntime *exec_runtime_ref(ExecRuntime *r);
ExecRuntime *exec_runtime_unref(ExecRuntime *r);

int exec_runtime_serialize(ExecRuntime *rt, Unit *u, FILE *f, FDSet *fds);
int exec_runtime_deserialize_item(ExecRuntime **rt, Unit *u, const char *key, const char *value, FDSet *fds);

void exec_runtime_destroy(ExecRuntime *rt);

const char* exec_output_to_string(ExecOutput i) _const_;
ExecOutput exec_output_from_string(const char *s) _pure_;

const char* exec_input_to_string(ExecInput i) _const_;
ExecInput exec_input_from_string(const char *s) _pure_;