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Diffstat (limited to 'src/core/execute.h')
| -rw-r--r-- | src/core/execute.h | 472 |
1 files changed, 472 insertions, 0 deletions
diff --git a/src/core/execute.h b/src/core/execute.h new file mode 100644 index 0000000..33d7e16 --- /dev/null +++ b/src/core/execute.h @@ -0,0 +1,472 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +typedef struct ExecStatus ExecStatus; +typedef struct ExecCommand ExecCommand; +typedef struct ExecContext ExecContext; +typedef struct ExecRuntime ExecRuntime; +typedef struct ExecParameters ExecParameters; +typedef struct Manager Manager; + +#include <sched.h> +#include <stdbool.h> +#include <stdio.h> +#include <sys/capability.h> + +#include "cgroup-util.h" +#include "coredump-util.h" +#include "cpu-set-util.h" +#include "exec-util.h" +#include "fdset.h" +#include "list.h" +#include "missing_resource.h" +#include "namespace.h" +#include "nsflags.h" +#include "numa-util.h" +#include "path-util.h" +#include "time-util.h" + +#define EXEC_STDIN_DATA_MAX (64U*1024U*1024U) + +typedef enum ExecUtmpMode { + EXEC_UTMP_INIT, + EXEC_UTMP_LOGIN, + EXEC_UTMP_USER, + _EXEC_UTMP_MODE_MAX, + _EXEC_UTMP_MODE_INVALID = -1 +} ExecUtmpMode; + +typedef enum ExecInput { + EXEC_INPUT_NULL, + EXEC_INPUT_TTY, + EXEC_INPUT_TTY_FORCE, + EXEC_INPUT_TTY_FAIL, + EXEC_INPUT_SOCKET, + EXEC_INPUT_NAMED_FD, + EXEC_INPUT_DATA, + EXEC_INPUT_FILE, + _EXEC_INPUT_MAX, + _EXEC_INPUT_INVALID = -1 +} ExecInput; + +typedef enum ExecOutput { + EXEC_OUTPUT_INHERIT, + EXEC_OUTPUT_NULL, + EXEC_OUTPUT_TTY, + EXEC_OUTPUT_KMSG, + EXEC_OUTPUT_KMSG_AND_CONSOLE, + EXEC_OUTPUT_JOURNAL, + EXEC_OUTPUT_JOURNAL_AND_CONSOLE, + EXEC_OUTPUT_SOCKET, + EXEC_OUTPUT_NAMED_FD, + EXEC_OUTPUT_FILE, + EXEC_OUTPUT_FILE_APPEND, + _EXEC_OUTPUT_MAX, + _EXEC_OUTPUT_INVALID = -1 +} ExecOutput; + +typedef enum ExecPreserveMode { + EXEC_PRESERVE_NO, + EXEC_PRESERVE_YES, + EXEC_PRESERVE_RESTART, + _EXEC_PRESERVE_MODE_MAX, + _EXEC_PRESERVE_MODE_INVALID = -1 +} ExecPreserveMode; + +typedef enum ExecKeyringMode { + EXEC_KEYRING_INHERIT, + EXEC_KEYRING_PRIVATE, + EXEC_KEYRING_SHARED, + _EXEC_KEYRING_MODE_MAX, + _EXEC_KEYRING_MODE_INVALID = -1, +} ExecKeyringMode; + +/* Contains start and exit information about an executed command. */ +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 siginfo_t::si_status */ +}; + +/* Stores information about commands we execute. Covers both configuration settings as well as runtime data. */ +struct ExecCommand { + char *path; + char **argv; + ExecStatus exec_status; + ExecCommandFlags flags; + LIST_FIELDS(ExecCommand, command); /* useful for chaining commands */ +}; + +/* Encapsulates certain aspects of the runtime environment that is to be shared between multiple otherwise separate + * invocations of commands. Specifically, this allows sharing of /tmp and /var/tmp data as well as network namespaces + * between invocations of commands. This is a reference counted object, with one reference taken by each currently + * active command invocation that wants to share this runtime. */ +struct ExecRuntime { + unsigned n_ref; + + Manager *manager; + + char *id; /* Unit id of the owner */ + + char *tmp_dir; + char *var_tmp_dir; + + /* An AF_UNIX socket pair, that contains a datagram containing a file descriptor referring to the network + * namespace. */ + int netns_storage_socket[2]; +}; + +typedef enum ExecDirectoryType { + EXEC_DIRECTORY_RUNTIME = 0, + EXEC_DIRECTORY_STATE, + EXEC_DIRECTORY_CACHE, + EXEC_DIRECTORY_LOGS, + EXEC_DIRECTORY_CONFIGURATION, + _EXEC_DIRECTORY_TYPE_MAX, + _EXEC_DIRECTORY_TYPE_INVALID = -1, +} ExecDirectoryType; + +typedef struct ExecDirectory { + char **paths; + mode_t mode; +} ExecDirectory; + +typedef enum ExecCleanMask { + /* In case you wonder why the bitmask below doesn't use "directory" in its name: we want to keep this + * generic so that .timer timestamp files can nicely be covered by this too, and similar. */ + EXEC_CLEAN_RUNTIME = 1U << EXEC_DIRECTORY_RUNTIME, + EXEC_CLEAN_STATE = 1U << EXEC_DIRECTORY_STATE, + EXEC_CLEAN_CACHE = 1U << EXEC_DIRECTORY_CACHE, + EXEC_CLEAN_LOGS = 1U << EXEC_DIRECTORY_LOGS, + EXEC_CLEAN_CONFIGURATION = 1U << EXEC_DIRECTORY_CONFIGURATION, + EXEC_CLEAN_NONE = 0, + EXEC_CLEAN_ALL = (1U << _EXEC_DIRECTORY_TYPE_MAX) - 1, + _EXEC_CLEAN_MASK_INVALID = -1, +} ExecCleanMask; + +/* A credential configured with SetCredential= */ +typedef struct ExecSetCredential { + char *id; + void *data; + size_t size; +} ExecSetCredential; + +/* Encodes configuration parameters applied to invoked commands. Does not carry runtime data, but only configuration + * changes sourced from unit files and suchlike. ExecContext objects are usually embedded into Unit objects, and do not + * change after being loaded. */ +struct ExecContext { + char **environment; + char **environment_files; + char **pass_environment; + char **unset_environment; + + struct rlimit *rlimit[_RLIMIT_MAX]; + char *working_directory, *root_directory, *root_image, *root_verity, *root_hash_path, *root_hash_sig_path; + void *root_hash, *root_hash_sig; + size_t root_hash_size, root_hash_sig_size; + LIST_HEAD(MountOptions, root_image_options); + bool working_directory_missing_ok:1; + bool working_directory_home:1; + + bool oom_score_adjust_set:1; + bool coredump_filter_set:1; + bool nice_set:1; + bool ioprio_set:1; + bool cpu_sched_set:1; + bool mount_apivfs_set:1; + + /* This is not exposed to the user but available internally. We need it to make sure that whenever we + * spawn /usr/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; + + bool cpu_sched_reset_on_fork; + bool non_blocking; + + mode_t umask; + int oom_score_adjust; + int nice; + int ioprio; + int cpu_sched_policy; + int cpu_sched_priority; + uint64_t coredump_filter; + + CPUSet cpu_set; + NUMAPolicy numa_policy; + bool cpu_affinity_from_numa; + + ExecInput std_input; + ExecOutput std_output; + ExecOutput std_error; + bool stdio_as_fds; + char *stdio_fdname[3]; + char *stdio_file[3]; + + void *stdin_data; + size_t stdin_data_size; + + nsec_t timer_slack_nsec; + + char *tty_path; + + bool tty_reset; + bool tty_vhangup; + bool tty_vt_disallocate; + + bool ignore_sigpipe; + + ExecKeyringMode keyring_mode; + + /* Since resolving these names 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; + ExecUtmpMode utmp_mode; + + bool no_new_privileges; + + bool selinux_context_ignore; + bool apparmor_profile_ignore; + bool smack_process_label_ignore; + + char *selinux_context; + char *apparmor_profile; + char *smack_process_label; + + char **read_write_paths, **read_only_paths, **inaccessible_paths; + unsigned long mount_flags; + BindMount *bind_mounts; + size_t n_bind_mounts; + TemporaryFileSystem *temporary_filesystems; + size_t n_temporary_filesystems; + MountImage *mount_images; + size_t n_mount_images; + + uint64_t capability_bounding_set; + uint64_t capability_ambient_set; + int secure_bits; + + int syslog_priority; + bool syslog_level_prefix; + char *syslog_identifier; + + struct iovec* log_extra_fields; + size_t n_log_extra_fields; + + usec_t log_ratelimit_interval_usec; + unsigned log_ratelimit_burst; + + int log_level_max; + + char *log_namespace; + + ProtectProc protect_proc; /* hidepid= */ + ProcSubset proc_subset; /* subset= */ + + bool private_tmp; + bool private_network; + bool private_devices; + bool private_users; + bool private_mounts; + bool protect_kernel_tunables; + bool protect_kernel_modules; + bool protect_kernel_logs; + bool protect_clock; + bool protect_control_groups; + ProtectSystem protect_system; + ProtectHome protect_home; + bool protect_hostname; + bool mount_apivfs; + + bool dynamic_user; + bool remove_ipc; + + bool memory_deny_write_execute; + bool restrict_realtime; + bool restrict_suid_sgid; + + bool lock_personality; + unsigned long personality; + + unsigned long restrict_namespaces; /* The CLONE_NEWxyz flags permitted to the unit's processes */ + + Hashmap *syscall_filter; + Set *syscall_archs; + int syscall_errno; + bool syscall_allow_list:1; + + Hashmap *syscall_log; + bool syscall_log_allow_list:1; /* Log listed system calls */ + + bool address_families_allow_list:1; + Set *address_families; + + char *network_namespace_path; + + ExecDirectory directories[_EXEC_DIRECTORY_TYPE_MAX]; + ExecPreserveMode runtime_directory_preserve_mode; + usec_t timeout_clean_usec; + + Hashmap *set_credentials; /* output id → ExecSetCredential */ + char **load_credentials; /* pairs of output id, path/input id */ +}; + +static inline bool exec_context_restrict_namespaces_set(const ExecContext *c) { + assert(c); + + return (c->restrict_namespaces & NAMESPACE_FLAGS_ALL) != NAMESPACE_FLAGS_ALL; +} + +static inline bool exec_context_with_rootfs(const ExecContext *c) { + assert(c); + + /* Checks if RootDirectory= or RootImage= are used */ + + return !empty_or_root(c->root_directory) || c->root_image; +} + +typedef enum ExecFlags { + EXEC_APPLY_SANDBOXING = 1 << 0, + EXEC_APPLY_CHROOT = 1 << 1, + EXEC_APPLY_TTY_STDIN = 1 << 2, + EXEC_PASS_LOG_UNIT = 1 << 3, /* Whether to pass the unit name to the service's journal stream connection */ + EXEC_CHOWN_DIRECTORIES = 1 << 4, /* chown() the runtime/state/cache/log directories to the user we run as, under all conditions */ + EXEC_NSS_BYPASS_BUS = 1 << 5, /* Set the SYSTEMD_NSS_BYPASS_BUS environment variable, to disable nss-systemd for dbus */ + EXEC_CGROUP_DELEGATE = 1 << 6, + EXEC_IS_CONTROL = 1 << 7, + EXEC_CONTROL_CGROUP = 1 << 8, /* Place the process not in the indicated cgroup but in a subcgroup '/.control', but only EXEC_CGROUP_DELEGATE and EXEC_IS_CONTROL is set, too */ + EXEC_WRITE_CREDENTIALS = 1 << 9, /* Set up the credential store logic */ + + /* The following are not used by execute.c, but by consumers internally */ + EXEC_PASS_FDS = 1 << 10, + EXEC_SETENV_RESULT = 1 << 11, + EXEC_SET_WATCHDOG = 1 << 12, +} ExecFlags; + +/* Parameters for a specific invocation of a command. This structure is put together right before a command is + * executed. */ +struct ExecParameters { + char **environment; + + int *fds; + char **fd_names; + size_t n_socket_fds; + size_t n_storage_fds; + + ExecFlags flags; + bool selinux_context_net:1; + + CGroupMask cgroup_supported; + const char *cgroup_path; + + char **prefix; + const char *received_credentials; + + const char *confirm_spawn; + + usec_t watchdog_usec; + + int *idle_pipe; + + int stdin_fd; + int stdout_fd; + int stderr_fd; + + /* An fd that is closed by the execve(), and thus will result in EOF when the execve() is done */ + int exec_fd; +}; + +#include "unit.h" +#include "dynamic-user.h" + +int exec_spawn(Unit *unit, + ExecCommand *command, + const ExecContext *context, + const ExecParameters *exec_params, + ExecRuntime *runtime, + DynamicCreds *dynamic_creds, + pid_t *ret); + +void exec_command_done_array(ExecCommand *c, size_t n); +ExecCommand* exec_command_free_list(ExecCommand *c); +void exec_command_free_array(ExecCommand **c, size_t n); +void exec_command_reset_status_array(ExecCommand *c, size_t n); +void exec_command_reset_status_list_array(ExecCommand **c, size_t n); +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, ...) _sentinel_; +int exec_command_append(ExecCommand *c, const char *path, ...) _sentinel_; + +void exec_context_init(ExecContext *c); +void exec_context_done(ExecContext *c); +void exec_context_dump(const ExecContext *c, FILE* f, const char *prefix); + +int exec_context_destroy_runtime_directory(const ExecContext *c, const char *runtime_root); +int exec_context_destroy_credentials(const ExecContext *c, const char *runtime_root, const char *unit); + +const char* exec_context_fdname(const ExecContext *c, int fd_index); + +bool exec_context_may_touch_console(const ExecContext *c); +bool exec_context_maintains_privileges(const ExecContext *c); + +int exec_context_get_effective_ioprio(const ExecContext *c); +bool exec_context_get_effective_mount_apivfs(const ExecContext *c); + +void exec_context_free_log_extra_fields(ExecContext *c); + +void exec_context_revert_tty(ExecContext *c); + +int exec_context_get_clean_directories(ExecContext *c, char **prefix, ExecCleanMask mask, char ***ret); +int exec_context_get_clean_mask(ExecContext *c, ExecCleanMask *ret); + +void exec_status_start(ExecStatus *s, pid_t pid); +void exec_status_exit(ExecStatus *s, const ExecContext *context, pid_t pid, int code, int status); +void exec_status_dump(const ExecStatus *s, FILE *f, const char *prefix); +void exec_status_reset(ExecStatus *s); + +int exec_runtime_acquire(Manager *m, const ExecContext *c, const char *name, bool create, ExecRuntime **ret); +ExecRuntime *exec_runtime_unref(ExecRuntime *r, bool destroy); + +int exec_runtime_serialize(const Manager *m, FILE *f, FDSet *fds); +int exec_runtime_deserialize_compat(Unit *u, const char *key, const char *value, FDSet *fds); +int exec_runtime_deserialize_one(Manager *m, const char *value, FDSet *fds); +void exec_runtime_vacuum(Manager *m); + +void exec_params_clear(ExecParameters *p); + +bool exec_context_get_cpu_affinity_from_numa(const ExecContext *c); + +ExecSetCredential *exec_set_credential_free(ExecSetCredential *sc); +DEFINE_TRIVIAL_CLEANUP_FUNC(ExecSetCredential*, exec_set_credential_free); + +extern const struct hash_ops exec_set_credential_hash_ops; + +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_; + +const char* exec_utmp_mode_to_string(ExecUtmpMode i) _const_; +ExecUtmpMode exec_utmp_mode_from_string(const char *s) _pure_; + +const char* exec_preserve_mode_to_string(ExecPreserveMode i) _const_; +ExecPreserveMode exec_preserve_mode_from_string(const char *s) _pure_; + +const char* exec_keyring_mode_to_string(ExecKeyringMode i) _const_; +ExecKeyringMode exec_keyring_mode_from_string(const char *s) _pure_; + +const char* exec_directory_type_to_string(ExecDirectoryType i) _const_; +ExecDirectoryType exec_directory_type_from_string(const char *s) _pure_; + +const char* exec_resource_type_to_string(ExecDirectoryType i) _const_; +ExecDirectoryType exec_resource_type_from_string(const char *s) _pure_; |