1SD_BUS_CREDS_NEW_FROM_PID(3)sd_bus_creds_new_from_piSdD_BUS_CREDS_NEW_FROM_PID(3)
2
6 sd_bus_creds_new_from_pid, sd_bus_creds_get_mask,
7 sd_bus_creds_get_augmented_mask, sd_bus_creds_ref, sd_bus_creds_unref,
8 sd_bus_creds_unrefp - Retrieve credentials object for the specified PID
9
11 #include <systemd/sd-bus.h>
12 int sd_bus_creds_new_from_pid(pid_t pid, uint64_t creds_mask,
14 sd_bus_creds **ret);
15 uint64_t sd_bus_creds_get_mask(sd_bus_creds *c);
17 uint64_t sd_bus_creds_get_augmented_mask(sd_bus_creds *c);
19 sd_bus_creds *sd_bus_creds_ref(sd_bus_creds *c);
21 sd_bus_creds *sd_bus_creds_unref(sd_bus_creds *c);
23 void sd_bus_creds_unrefp(sd_bus_creds **c);
25 SD_BUS_CREDS_PID, SD_BUS_CREDS_PPID, SD_BUS_CREDS_TID,
27 SD_BUS_CREDS_UID, SD_BUS_CREDS_EUID, SD_BUS_CREDS_SUID,
28 SD_BUS_CREDS_FSUID, SD_BUS_CREDS_GID, SD_BUS_CREDS_EGID,
29 SD_BUS_CREDS_SGID, SD_BUS_CREDS_FSGID, SD_BUS_CREDS_SUPPLEMENTARY_GIDS,
30 SD_BUS_CREDS_COMM, SD_BUS_CREDS_TID_COMM, SD_BUS_CREDS_EXE,
31 SD_BUS_CREDS_CMDLINE, SD_BUS_CREDS_CGROUP, SD_BUS_CREDS_UNIT,
32 SD_BUS_CREDS_SLICE, SD_BUS_CREDS_USER_UNIT, SD_BUS_CREDS_USER_SLICE,
33 SD_BUS_CREDS_SESSION, SD_BUS_CREDS_OWNER_UID,
34 SD_BUS_CREDS_EFFECTIVE_CAPS, SD_BUS_CREDS_PERMITTED_CAPS,
35 SD_BUS_CREDS_INHERITABLE_CAPS, SD_BUS_CREDS_BOUNDING_CAPS,
36 SD_BUS_CREDS_SELINUX_CONTEXT, SD_BUS_CREDS_AUDIT_SESSION_ID,
37 SD_BUS_CREDS_AUDIT_LOGIN_UID, SD_BUS_CREDS_TTY,
38 SD_BUS_CREDS_UNIQUE_NAME, SD_BUS_CREDS_WELL_KNOWN_NAMES,
39 SD_BUS_CREDS_DESCRIPTION, SD_BUS_CREDS_AUGMENT, _SD_BUS_CREDS_ALL
40
42 sd_bus_creds_new_from_pid() creates a new credentials object and fills
43 it with information about the process pid. The pointer to this object
44 will be stored in the ret pointer. Note that credential objects may
45 also be created and retrieved via sd_bus_get_name_creds(3),
46 sd_bus_get_owner_creds(3) and sd_bus_message_get_creds(3).
47 The information that will be stored is determined by creds_mask. It may
49 contain a subset of ORed constants SD_BUS_CREDS_PID, SD_BUS_CREDS_PPID,
50 SD_BUS_CREDS_TID, SD_BUS_CREDS_UID, SD_BUS_CREDS_EUID,
51 SD_BUS_CREDS_SUID, SD_BUS_CREDS_FSUID, SD_BUS_CREDS_GID,
52 SD_BUS_CREDS_EGID, SD_BUS_CREDS_SGID, SD_BUS_CREDS_FSGID,
53 SD_BUS_CREDS_SUPPLEMENTARY_GIDS, SD_BUS_CREDS_COMM,
54 SD_BUS_CREDS_TID_COMM, SD_BUS_CREDS_EXE, SD_BUS_CREDS_CMDLINE,
55 SD_BUS_CREDS_CGROUP, SD_BUS_CREDS_UNIT, SD_BUS_CREDS_SLICE,
56 SD_BUS_CREDS_USER_UNIT, SD_BUS_CREDS_USER_SLICE, SD_BUS_CREDS_SESSION,
57 SD_BUS_CREDS_OWNER_UID, SD_BUS_CREDS_EFFECTIVE_CAPS,
58 SD_BUS_CREDS_PERMITTED_CAPS, SD_BUS_CREDS_INHERITABLE_CAPS,
59 SD_BUS_CREDS_BOUNDING_CAPS, SD_BUS_CREDS_SELINUX_CONTEXT,
60 SD_BUS_CREDS_AUDIT_SESSION_ID, SD_BUS_CREDS_AUDIT_LOGIN_UID,
61 SD_BUS_CREDS_TTY, SD_BUS_CREDS_UNIQUE_NAME,
62 SD_BUS_CREDS_WELL_KNOWN_NAMES, and SD_BUS_CREDS_DESCRIPTION. Use the
63 special value _SD_BUS_CREDS_ALL to request all supported fields. The
64 SD_BUS_CREDS_AUGMENT constant may not be ORed into the mask for
65 invocations of sd_bus_creds_new_from_pid().
66 Fields can be retrieved from the credentials object using
68 sd_bus_creds_get_pid(3) and other functions which correspond directly
69 to the constants listed above.
70 A mask of fields which were actually successfully retrieved can be
72 retrieved with sd_bus_creds_get_mask(). If the credentials object was
73 created with sd_bus_creds_new_from_pid(), this will be a subset of
74 fields requested in creds_mask.
75 Similar to sd_bus_creds_get_mask(), the function
77 sd_bus_creds_get_augmented_mask() returns a bitmask of field constants.
78 The mask indicates which credential fields have been retrieved in a
79 non-atomic fashion. For credential objects created via
80 sd_bus_creds_new_from_pid(), this mask will be identical to the mask
81 returned by sd_bus_creds_get_mask(). However, for credential objects
82 retrieved via sd_bus_get_name_creds(), this mask will be set for the
83 credential fields that could not be determined atomically at peer
84 connection time, and which were later added by reading augmenting
85 credential data from /proc/. Similarly, for credential objects
86 retrieved via sd_bus_get_owner_creds(), the mask is set for the fields
87 that could not be determined atomically at bus creation time, but have
88 been augmented. Similarly, for credential objects retrieved via
89 sd_bus_message_get_creds(), the mask is set for the fields that could
90 not be determined atomically at message sending time, but have been
91 augmented. The mask returned by sd_bus_creds_get_augmented_mask() is
92 always a subset of (or identical to) the mask returned by
93 sd_bus_creds_get_mask() for the same object. The latter call hence
94 returns all credential fields available in the credential object, the
95 former then marks the subset of those that have been augmented. Note
96 that augmented fields are unsuitable for authorization decisions, as
97 they may be retrieved at different times, thus being subject to races.
98 Hence, augmented fields should be used exclusively for informational
99 purposes.
100 sd_bus_creds_ref() creates a new reference to the credentials object c.
102 This object will not be destroyed until sd_bus_creds_unref() has been
103 called as many times plus once more. Once the reference count has
104 dropped to zero, c cannot be used anymore, so further calls to
105 sd_bus_creds_ref(c) or sd_bus_creds_unref(c) are illegal.
106 sd_bus_creds_unref() destroys a reference to c.
108 sd_bus_creds_unrefp() is similar to sd_bus_creds_unref() but takes a
110 pointer to a pointer to an sd_bus_creds object. This call is useful in
111 conjunction with GCC's and LLVM's Clean-up Variable Attribute[1]. Note
112 that this function is defined as inline function.
113 sd_bus_creds_ref(), sd_bus_creds_unref() and sd_bus_creds_unrefp()
115 execute no operation if the passed in bus credentials object is NULL.
116
118 On success, sd_bus_creds_new_from_pid() returns 0 or a positive
119 integer. On failure, it returns a negative errno-style error code.
120 sd_bus_creds_get_mask() returns the mask of successfully acquired
122 fields.
123 sd_bus_creds_get_augmented_mask() returns the mask of fields that have
125 been augmented from data in /proc/, and are thus not suitable for
126 authorization decisions.
127 sd_bus_creds_ref() always returns the argument.
129 sd_bus_creds_unref() always returns NULL.
131
133 Function sd_bus_creds_new_from_pid() creates a new object and the
134 caller owns the sole reference. When not needed anymore, this reference
135 should be destroyed with sd_bus_creds_unref(3).
136 Errors
138 Returned errors may indicate the following problems:
139 -ESRCH
141 Specified pid could not be found.
142 -EINVAL
144 Specified parameter is invalid (NULL in case of output parameters).
145 -ENOMEM
147 Memory allocation failed.
148 -EOPNOTSUPP
150 One of the requested fields is unknown to the local system.
151
153 Functions described here are available as a shared library, which can
154 be compiled against and linked to with the libsystemd pkg-config(1)
155 file.
156 The code described here uses getenv(3), which is declared to be not
158 multi-thread-safe. This means that the code calling the functions
159 described here must not call setenv(3) from a parallel thread. It is
160 recommended to only do calls to setenv() from an early phase of the
161 program when no other threads have been started.
162
164 systemd(1), sd-bus(3), sd_bus_creds_get_pid(3),
165 sd_bus_get_name_creds(3), sd_bus_get_owner_creds(3),
166 sd_bus_message_get_creds(3)
167
169 1. Clean-up Variable Attribute
170 https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html
171systemd 254 SD_BUS_CREDS_NEW_FROM_PID(3)