xref: /freebsd/lib/libc/posix1e/mac_get.3 (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
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31.Dd September 21, 2023
32.Dt MAC_GET 3
33.Os
34.Sh NAME
35.Nm mac_get_file ,
36.Nm mac_get_link ,
37.Nm mac_get_fd ,
38.Nm mac_get_peer ,
39.Nm mac_get_pid ,
40.Nm mac_get_proc
41.Nd get the label of a file, socket, socket peer or process
42.Sh LIBRARY
43.Lb libc
44.Sh SYNOPSIS
45.In sys/mac.h
46.Ft int
47.Fn mac_get_file "const char *path" "mac_t label"
48.Ft int
49.Fn mac_get_link "const char *path" "mac_t label"
50.Ft int
51.Fn mac_get_fd "int fd" "mac_t label"
52.Ft int
53.Fn mac_get_peer "int fd" "mac_t label"
54.Ft int
55.Fn mac_get_pid "pid_t pid" "mac_t label"
56.Ft int
57.Fn mac_get_proc "mac_t label"
58.Sh DESCRIPTION
59The
60.Fn mac_get_file
61system call returns the label associated with a file specified by
62pathname.
63The
64.Fn mac_get_link
65function is the same as
66.Fn mac_get_file ,
67except that it does not follow symlinks.
68.Pp
69The
70.Fn mac_get_fd
71system call returns the label associated with an object referenced by
72the specified file descriptor.
73Note that in the case of a file system socket, the label returned will
74be the socket label, which may be different from the label of the
75on-disk node acting as a rendezvous for the socket.
76The
77.Fn mac_get_peer
78system call returns the label associated with the remote endpoint of
79a socket; the exact semantics of this call will depend on the protocol
80domain, communications type, and endpoint; typically this label will
81be cached when a connection-oriented protocol instance is first set up,
82and is undefined for datagram protocols.
83.Pp
84The
85.Fn mac_get_pid
86and
87.Fn mac_get_proc
88system calls return the process label associated with an arbitrary
89process ID, or the current process.
90.Pp
91Label storage for use with these calls must first be allocated and
92prepared using the
93.Xr mac_prepare 3
94functions.
95When an application is done using a label, the memory may be returned
96using
97.Xr mac_free 3 .
98.Sh ERRORS
99.Bl -tag -width Er
100.It Bq Er EACCES
101A component of
102.Fa path
103is not searchable,
104or MAC read access to the file
105is denied.
106.It Bq Er EINVAL
107The requested label operation is not valid for the object referenced by
108.Fa fd .
109.It Bq Er ENAMETOOLONG
110The pathname pointed to by
111.Fa path
112exceeds
113.Dv PATH_MAX ,
114or a component of the pathname exceeds
115.Dv NAME_MAX .
116.It Bq Er ENOENT
117A component of
118.Fa path
119does not exist.
120.It Bq Er ENOMEM
121Insufficient memory is available
122to allocate a new MAC label structure.
123.It Bq Er ENOTDIR
124A component of
125.Fa path
126is not a directory.
127.El
128.Sh SEE ALSO
129.Xr mac 3 ,
130.Xr mac_free 3 ,
131.Xr mac_prepare 3 ,
132.Xr mac_set 3 ,
133.Xr mac_text 3 ,
134.Xr posix1e 3 ,
135.Xr mac 4 ,
136.Xr mac 9
137.Sh STANDARDS
138POSIX.1e is described in IEEE POSIX.1e draft 17.
139.Sh HISTORY
140Support for Mandatory Access Control was introduced in
141.Fx 5.0
142as part of the
143.Tn TrustedBSD
144Project.
145