1VMOD(UNIX)                                                          VMOD(UNIX)
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NAME

6       VMOD unix - Utilities for Unix domain sockets
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SYNOPSIS

9          import unix [as name] [from "path"]
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11          STRING user()
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13          STRING group()
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15          INT uid()
16
17          INT gid()
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DESCRIPTION

20       This  VMOD  provides  information  about  the  credentials  of the peer
21       process (user and group of the process owner) that is  connected  to  a
22       Varnish listener via a Unix domain socket, if the platform supports it.
23
24       Examples:
25
26          import unix;
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28          sub vcl_recv {
29                # Return "403 Forbidden" if the connected peer is
30                # not running as the user "trusteduser".
31                if (unix.user() != "trusteduser") {
32                        return( synth(403) );
33                }
34
35                # Require the connected peer to run in the group
36                # "trustedgroup".
37                if (unix.group() != "trustedgroup") {
38                        return( synth(403) );
39                }
40
41                # Require the connected peer to run under a specific numeric
42                # user id.
43                if (unix.uid() != 4711) {
44                        return( synth(403) );
45                }
46
47                # Require the connected peer to run under a numeric group id.
48                if (unix.gid() != 815) {
49                        return( synth(403) );
50                }
51          }
52
53       Obtaining  the peer credentials is possible on a platform that supports
54       one of the following:
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56       · getpeereid(3) (such as FreeBSD and other BSD-derived systems)
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58       · the socket option SO_PEERCRED for getsockopt(2) (Linux)
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60       · getpeerucred(3C) (SunOS and descendants)
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62       On SunOS and friends, the PRIV_PROC_INFO privilege set is added to  the
63       Varnish child process while the VMOD is loaded, see setppriv(2).
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65       On  most  platforms,  the value returned is the effective user or group
66       that was valid when the peer process initiated the connection.
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68   STRING user()
69       Return the user name of the peer process owner.
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71   STRING group()
72       Return the group name of the peer process owner.
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74   INT uid()
75       Return the numeric user id of the peer process owner.
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77   INT gid()
78       Return the numeric group id of the peer process owner.
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ERRORS

81       All functions in this VMOD are subject to the following constraints:
82
83       · None of them may be called in vcl_init{} or  vcl_fini{}.  If  one  of
84         them is called in vcl_init{}, then the VCL program will fail to load,
85         with an error message from the VMOD.
86
87       · If called on a platform that is not supported, then  VCL  failure  is
88         invoked.  An  error message is written to the log (with the VCL_Error
89         tag), and for all VCL subroutines except for vcl_synth{}, control  is
90         directed  immediately to vcl_synth{}, with the response status set to
91         503 and the reason string set to "VCL failed".
92
93         If  the  failure  occurs  during  vcl_synth{},  then  vcl_synth{}  is
94         aborted, and the the response line "503 VCL failed" is sent.
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96       · If  the  current  listener  is  not  a  Unix domain socket, or if the
97         attempt to read credentials fails, then a VCL_Error message is  writ‐
98         ten  to  the log. The STRING functions (unix.user() and unix.group())
99         return NULL, while the  INT  functions  (unix.uid()  and  unix.gid())
100         return -1.
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SEE ALSO

103       · varnishd(1)
104
105       · vcl(7)
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107       · getpeereid(3)
108
109       · getsockopt(2)
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111       · getpeerucred(3C)
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113       · setppriv(2)
114

116          This document is licensed under the same conditions as Varnish itself.
117          See LICENSE for details.
118
119          Authors: Geoffrey Simmons <geoffrey.simmons@uplex.de>
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124                                       3                            VMOD(UNIX)
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