получить объект учетных данных для указанного PID (retrieve credentials object for the specified PID)
Имя (Name)
sd_bus_creds_new_from_pid, sd_bus_creds_get_mask,
sd_bus_creds_get_augmented_mask, sd_bus_creds_ref,
sd_bus_creds_unref, sd_bus_creds_unrefp - Retrieve credentials
object for the specified PID
Синопсис (Synopsis)
#include <systemd/sd-bus.h>
int sd_bus_creds_new_from_pid(pid_t pid, uint64_t creds_mask,
sd_bus_creds **ret);
uint64_t sd_bus_creds_get_mask(sd_bus_creds *c);
uint64_t sd_bus_creds_get_augmented_mask(sd_bus_creds *c);
sd_bus_creds *sd_bus_creds_ref(sd_bus_creds *c);
sd_bus_creds *sd_bus_creds_unref(sd_bus_creds *c);
void sd_bus_creds_unrefp(sd_bus_creds **c);
SD_BUS_CREDS_PID, SD_BUS_CREDS_PPID, SD_BUS_CREDS_TID,
SD_BUS_CREDS_UID, SD_BUS_CREDS_EUID, SD_BUS_CREDS_SUID,
SD_BUS_CREDS_FSUID, SD_BUS_CREDS_GID, SD_BUS_CREDS_EGID,
SD_BUS_CREDS_SGID, SD_BUS_CREDS_FSGID,
SD_BUS_CREDS_SUPPLEMENTARY_GIDS, SD_BUS_CREDS_COMM,
SD_BUS_CREDS_TID_COMM, SD_BUS_CREDS_EXE, SD_BUS_CREDS_CMDLINE,
SD_BUS_CREDS_CGROUP, SD_BUS_CREDS_UNIT, SD_BUS_CREDS_SLICE,
SD_BUS_CREDS_USER_UNIT, SD_BUS_CREDS_USER_SLICE,
SD_BUS_CREDS_SESSION, SD_BUS_CREDS_OWNER_UID,
SD_BUS_CREDS_EFFECTIVE_CAPS, SD_BUS_CREDS_PERMITTED_CAPS,
SD_BUS_CREDS_INHERITABLE_CAPS, SD_BUS_CREDS_BOUNDING_CAPS,
SD_BUS_CREDS_SELINUX_CONTEXT, SD_BUS_CREDS_AUDIT_SESSION_ID,
SD_BUS_CREDS_AUDIT_LOGIN_UID, SD_BUS_CREDS_TTY,
SD_BUS_CREDS_UNIQUE_NAME, SD_BUS_CREDS_WELL_KNOWN_NAMES,
SD_BUS_CREDS_DESCRIPTION, SD_BUS_CREDS_AUGMENT, _SD_BUS_CREDS_ALL
Описание (Description)
sd_bus_creds_new_from_pid() creates a new credentials object and
fills it with information about the process pid. The pointer to
this object will be stored in the ret pointer. Note that
credential objects may also be created and retrieved via
sd_bus_get_name_creds(3), sd_bus_get_owner_creds(3) and
sd_bus_message_get_creds(3).
The information that will be stored is determined by creds_mask.
It may contain a subset of ORed constants SD_BUS_CREDS_PID,
SD_BUS_CREDS_PPID, SD_BUS_CREDS_TID, SD_BUS_CREDS_UID,
SD_BUS_CREDS_EUID, SD_BUS_CREDS_SUID, SD_BUS_CREDS_FSUID,
SD_BUS_CREDS_GID, SD_BUS_CREDS_EGID, SD_BUS_CREDS_SGID,
SD_BUS_CREDS_FSGID, SD_BUS_CREDS_SUPPLEMENTARY_GIDS,
SD_BUS_CREDS_COMM, SD_BUS_CREDS_TID_COMM, SD_BUS_CREDS_EXE,
SD_BUS_CREDS_CMDLINE, SD_BUS_CREDS_CGROUP, SD_BUS_CREDS_UNIT,
SD_BUS_CREDS_SLICE, SD_BUS_CREDS_USER_UNIT,
SD_BUS_CREDS_USER_SLICE, SD_BUS_CREDS_SESSION,
SD_BUS_CREDS_OWNER_UID, SD_BUS_CREDS_EFFECTIVE_CAPS,
SD_BUS_CREDS_PERMITTED_CAPS, SD_BUS_CREDS_INHERITABLE_CAPS,
SD_BUS_CREDS_BOUNDING_CAPS, SD_BUS_CREDS_SELINUX_CONTEXT,
SD_BUS_CREDS_AUDIT_SESSION_ID, SD_BUS_CREDS_AUDIT_LOGIN_UID,
SD_BUS_CREDS_TTY, SD_BUS_CREDS_UNIQUE_NAME,
SD_BUS_CREDS_WELL_KNOWN_NAMES, and SD_BUS_CREDS_DESCRIPTION. Use
the special value _SD_BUS_CREDS_ALL to request all supported
fields. The SD_BUS_CREDS_AUGMENT constant may not be ORed into
the mask for invocations of sd_bus_creds_new_from_pid().
Fields can be retrieved from the credentials object using
sd_bus_creds_get_pid(3) and other functions which correspond
directly to the constants listed above.
A mask of fields which were actually successfully retrieved can
be retrieved with sd_bus_creds_get_mask(). If the credentials
object was created with sd_bus_creds_new_from_pid(), this will be
a subset of fields requested in creds_mask.
Similar to sd_bus_creds_get_mask(), the function
sd_bus_creds_get_augmented_mask() returns a bitmask of field
constants. The mask indicates which credential fields have been
retrieved in a non-atomic fashion. For credential objects created
via sd_bus_creds_new_from_pid(), this mask will be identical to
the mask returned by sd_bus_creds_get_mask(). However, for
credential objects retrieved via sd_bus_get_name_creds(), this
mask will be set for the credential fields that could not be
determined atomically at peer connection time, and which were
later added by reading augmenting credential data from /proc/.
Similarly, for credential objects retrieved via
sd_bus_get_owner_creds(), the mask is set for the fields that
could not be determined atomically at bus creation time, but have
been augmented. Similarly, for credential objects retrieved via
sd_bus_message_get_creds(), the mask is set for the fields that
could not be determined atomically at message sending time, but
have been augmented. The mask returned by
sd_bus_creds_get_augmented_mask() is always a subset of (or
identical to) the mask returned by sd_bus_creds_get_mask() for
the same object. The latter call hence returns all credential
fields available in the credential object, the former then marks
the subset of those that have been augmented. Note that augmented
fields are unsuitable for authorization decisions, as they may be
retrieved at different times, thus being subject to races. Hence,
augmented fields should be used exclusively for informational
purposes.
sd_bus_creds_ref() creates a new reference to the credentials
object c. This object will not be destroyed until
sd_bus_creds_unref() has been called as many times plus once
more. Once the reference count has dropped to zero, c cannot be
used anymore, so further calls to sd_bus_creds_ref(c) or
sd_bus_creds_unref(c) are illegal.
sd_bus_creds_unref() destroys a reference to c.
sd_bus_creds_unrefp() is similar to sd_bus_creds_unref() but
takes a pointer to a pointer to an sd_bus_creds object. This call
is useful in conjunction with GCC's and LLVM's Clean-up Variable
Attribute
sd_bus_creds_ref(), sd_bus_creds_unref() and
sd_bus_creds_unrefp() execute no operation if the passed in bus
credentials object is NULL.
Возвращаемое значение (Return value)
On success, sd_bus_creds_new_from_pid() returns 0 or a positive
integer. On failure, it returns a negative errno-style error
code.
sd_bus_creds_get_mask() returns the mask of successfully acquired
fields.
sd_bus_creds_get_augmented_mask() returns the mask of fields that
have been augmented from data in /proc/, and are thus not
suitable for authorization decisions.
sd_bus_creds_ref() always returns the argument.
sd_bus_creds_unref() always returns NULL.
Function sd_bus_creds_new_from_pid() creates a new object and the
caller owns the sole reference. When not needed anymore, this
reference should be destroyed with sd_bus_creds_unref(3).
Errors
Returned errors may indicate the following problems:
-ESRCH
Specified pid could not be found.
-EINVAL
Specified parameter is invalid (NULL in case of output
parameters).
-ENOMEM
Memory allocation failed.
-EOPNOTSUPP
One of the requested fields is unknown to the local system.
Примечание (Note)
These APIs are implemented as a shared library, which can be
compiled and linked to with the libsystemd pkg-config(1) file.
Смотри также (See also)
systemd(1), sd-bus(3), sd_bus_creds_get_pid(3),
sd_bus_get_name_creds(3), sd_bus_get_owner_creds(3),
sd_bus_message_get_creds(3)
Примечание (Note)
1. Clean-up Variable Attribute
https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html
