2833 lines
64 KiB
Groff
2833 lines
64 KiB
Groff
.\" DO NOT EDIT THIS FILE, IT IS NOT THE MASTER!
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.\" IT IS GENERATED AUTOMATICALLY FROM sudo_plugin.mdoc.in
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.\"
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.\" Copyright (c) 2009-2017 Todd C. Miller <Todd.Miller@courtesan.com>
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.\"
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.\" Permission to use, copy, modify, and distribute this software for any
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.\" purpose with or without fee is hereby granted, provided that the above
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.\" copyright notice and this permission notice appear in all copies.
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.\"
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.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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.\" ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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.\"
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.TH "SUDO_PLUGIN" "5" "February 16, 2017" "Sudo @PACKAGE_VERSION@" "File Formats Manual"
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.nh
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.if n .ad l
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.SH "NAME"
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\fBsudo_plugin\fR
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\- Sudo Plugin API
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.SH "DESCRIPTION"
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Starting with version 1.8,
|
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\fBsudo\fR
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|
supports a plugin API
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for policy and session logging.
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Plugins may be compiled as dynamic shared objects (the default on
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systems that support them) or compiled statically into the
|
|
\fBsudo\fR
|
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binary itself.
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By default, the
|
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\fBsudoers\fR
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|
policy plugin and an associated I/O logging plugin are used.
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Via the plugin API,
|
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\fBsudo\fR
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can be configured to use alternate policy and/or I/O logging plugins
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provided by third parties.
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The plugins to be used are specified in the
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sudo.conf(@mansectform@)
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|
file.
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.PP
|
|
The API is versioned with a major and minor number.
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|
The minor version number is incremented when additions are made.
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The major number is incremented when incompatible changes are made.
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A plugin should be check the version passed to it and make sure that the
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major version matches.
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.PP
|
|
The plugin API is defined by the
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|
\fRsudo_plugin.h\fR
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|
header file.
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.SS "Policy plugin API"
|
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A policy plugin must declare and populate a
|
|
\fRpolicy_plugin\fR
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|
struct in the global scope.
|
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This structure contains pointers to the functions that implement the
|
|
\fBsudo\fR
|
|
policy checks.
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|
The name of the symbol should be specified in
|
|
sudo.conf(@mansectform@)
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|
along with a path to the plugin so that
|
|
\fBsudo\fR
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|
can load it.
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.nf
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.sp
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|
.RS 0n
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|
struct policy_plugin {
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#define SUDO_POLICY_PLUGIN 1
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unsigned int type; /* always SUDO_POLICY_PLUGIN */
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unsigned int version; /* always SUDO_API_VERSION */
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int (*open)(unsigned int version, sudo_conv_t conversation,
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|
sudo_printf_t plugin_printf, char * const settings[],
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char * const user_info[], char * const user_env[],
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char * const plugin_options[]);
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void (*close)(int exit_status, int error);
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int (*show_version)(int verbose);
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int (*check_policy)(int argc, char * const argv[],
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|
char *env_add[], char **command_info[],
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char **argv_out[], char **user_env_out[]);
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int (*list)(int argc, char * const argv[], int verbose,
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|
const char *list_user);
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int (*validate)(void);
|
|
void (*invalidate)(int remove);
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|
int (*init_session)(struct passwd *pwd, char **user_env[]);
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void (*register_hooks)(int version,
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int (*register_hook)(struct sudo_hook *hook));
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|
void (*deregister_hooks)(int version,
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int (*deregister_hook)(struct sudo_hook *hook));
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};
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.RE
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|
.fi
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.PP
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|
The policy_plugin struct has the following fields:
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.TP 6n
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|
type
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|
The
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\fRtype\fR
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|
field should always be set to SUDO_POLICY_PLUGIN.
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.TP 6n
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|
version
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|
The
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|
\fRversion\fR
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|
field should be set to
|
|
\fRSUDO_API_VERSION\fR.
|
|
.sp
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|
This allows
|
|
\fBsudo\fR
|
|
to determine the API version the plugin was
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|
built against.
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.TP 6n
|
|
open
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|
.nf
|
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.RS 6n
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|
int (*open)(unsigned int version, sudo_conv_t conversation,
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|
sudo_printf_t plugin_printf, char * const settings[],
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char * const user_info[], char * const user_env[],
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char * const plugin_options[]);
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.RE
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|
.fi
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.RS 6n
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|
.sp
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|
Returns 1 on success, 0 on failure, \-1 if a general error occurred,
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or \-2 if there was a usage error.
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|
In the latter case,
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|
\fBsudo\fR
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|
will print a usage message before it exits.
|
|
If an error occurs, the plugin may optionally call the
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|
\fBconversation\fR()
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or
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|
\fBplugin_printf\fR()
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|
function with
|
|
\fRSUDO_CONF_ERROR_MSG\fR
|
|
to present additional error information to the user.
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|
.sp
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The function arguments are as follows:
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.TP 6n
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|
version
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The version passed in by
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\fBsudo\fR
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allows the plugin to determine the
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|
major and minor version number of the plugin API supported by
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|
\fBsudo\fR.
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.TP 6n
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conversation
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|
A pointer to the
|
|
\fBconversation\fR()
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|
function that can be used by the plugin to interact with the user (see below).
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Returns 0 on success and \-1 on failure.
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.TP 6n
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|
plugin_printf
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A pointer to a
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|
\fBprintf\fR()-style
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|
function that may be used to display informational or error messages
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|
(see below).
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|
Returns the number of characters printed on success and \-1 on failure.
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.TP 6n
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|
settings
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A vector of user-supplied
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|
\fBsudo\fR
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settings in the form of
|
|
\(Lqname=value\(Rq
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strings.
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The vector is terminated by a
|
|
\fRNULL\fR
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pointer.
|
|
These settings correspond to flags the user specified when running
|
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\fBsudo\fR.
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As such, they will only be present when the corresponding flag has
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been specified on the command line.
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.sp
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When parsing
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|
\fIsettings\fR,
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the plugin should split on the
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\fBfirst\fR
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equal sign
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(\(oq=\(cq)
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since the
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\fIname\fR
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|
field will never include one
|
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itself but the
|
|
\fIvalue\fR
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|
might.
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.PP
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|
.RS 6n
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|
.PD 0
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|
.TP 6n
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bsdauth_type=string
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Authentication type, if specified by the
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\fB\-a\fR
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|
flag, to use on
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systems where BSD authentication is supported.
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.PD
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.TP 6n
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closefrom=number
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|
If specified, the user has requested via the
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\fB\-C\fR
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|
flag that
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|
\fBsudo\fR
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|
close all files descriptors with a value of
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|
\fInumber\fR
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|
or higher.
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The plugin may optionally pass this, or another value, back in the
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\fIcommand_info\fR
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list.
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.TP 6n
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debug_flags=string
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A debug file path name followed by a space and a comma-separated
|
|
list of debug flags that correspond to the plugin's
|
|
\fRDebug\fR
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|
entry in
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sudo.conf(@mansectform@),
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|
if there is one.
|
|
The flags are passed to the plugin exactly as they appear in
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sudo.conf(@mansectform@).
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|
The syntax used by
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\fBsudo\fR
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and the
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\fBsudoers\fR
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plugin is
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|
\fIsubsystem\fR@\fIpriority\fR
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|
but a plugin is free to use a different
|
|
format so long as it does not include a comma
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|
(\(oq,\&\(cq).
|
|
Prior to
|
|
\fBsudo\fR
|
|
1.8.12, there was no way to specify plugin-specific
|
|
\fIdebug_flags\fR
|
|
so the value was always the same as that used by the
|
|
\fBsudo\fR
|
|
front end and did not include a path name, only the flags themselves.
|
|
As of version 1.7 of the plugin interface,
|
|
\fBsudo\fR
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|
will only pass
|
|
\fIdebug_flags\fR
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|
if
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|
sudo.conf(@mansectform@)
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|
contains a plugin-specific
|
|
\fRDebug\fR
|
|
entry.
|
|
.TP 6n
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|
debug_level=number
|
|
This setting has been deprecated in favor of
|
|
\fIdebug_flags\fR.
|
|
.TP 6n
|
|
ignore_ticket=bool
|
|
Set to true if the user specified the
|
|
\fB\-k\fR
|
|
flag along with a
|
|
command, indicating that the user wishes to ignore any cached
|
|
authentication credentials.
|
|
\fIimplied_shell\fR
|
|
to true.
|
|
This allows
|
|
\fBsudo\fR
|
|
with no arguments
|
|
to be used similarly to
|
|
su(1).
|
|
If the plugin does not to support this usage, it may return a value of \-2
|
|
from the
|
|
\fBcheck_policy\fR()
|
|
function, which will cause
|
|
\fBsudo\fR
|
|
to print a usage message and
|
|
exit.
|
|
.TP 6n
|
|
implied_shell=bool
|
|
If the user does not specify a program on the command line,
|
|
\fBsudo\fR
|
|
will pass the plugin the path to the user's shell and set
|
|
.TP 6n
|
|
login_class=string
|
|
BSD login class to use when setting resource limits and nice value,
|
|
if specified by the
|
|
\fB\-c\fR
|
|
flag.
|
|
.TP 6n
|
|
login_shell=bool
|
|
Set to true if the user specified the
|
|
\fB\-i\fR
|
|
flag, indicating that
|
|
the user wishes to run a login shell.
|
|
.TP 6n
|
|
max_groups=int
|
|
The maximum number of groups a user may belong to.
|
|
This will only be present if there is a corresponding setting in
|
|
sudo.conf(@mansectform@).
|
|
.TP 6n
|
|
network_addrs=list
|
|
A space-separated list of IP network addresses and netmasks in the
|
|
form
|
|
\(Lqaddr/netmask\(Rq,
|
|
e.g.\&
|
|
\(Lq192.168.1.2/255.255.255.0\(Rq.
|
|
The address and netmask pairs may be either IPv4 or IPv6, depending on
|
|
what the operating system supports.
|
|
If the address contains a colon
|
|
(\(oq:\&\(cq),
|
|
it is an IPv6 address, else it is IPv4.
|
|
.TP 6n
|
|
noninteractive=bool
|
|
Set to true if the user specified the
|
|
\fB\-n\fR
|
|
flag, indicating that
|
|
\fBsudo\fR
|
|
should operate in non-interactive mode.
|
|
The plugin may reject a command run in non-interactive mode if user
|
|
interaction is required.
|
|
.TP 6n
|
|
plugin_dir=string
|
|
The default plugin directory used by the
|
|
\fBsudo\fR
|
|
front end.
|
|
This is the default directory set at compile time and may not
|
|
correspond to the directory the running plugin was loaded from.
|
|
It may be used by a plugin to locate support files.
|
|
.TP 6n
|
|
plugin_path=string
|
|
The path name of plugin loaded by the
|
|
\fBsudo\fR
|
|
front end.
|
|
The path name will be a fully-qualified unless the plugin was
|
|
statically compiled into
|
|
\fBsudo\fR.
|
|
.TP 6n
|
|
preserve_environment=bool
|
|
Set to true if the user specified the
|
|
\fB\-E\fR
|
|
flag, indicating that
|
|
the user wishes to preserve the environment.
|
|
.TP 6n
|
|
preserve_groups=bool
|
|
Set to true if the user specified the
|
|
\fB\-P\fR
|
|
flag, indicating that
|
|
the user wishes to preserve the group vector instead of setting it
|
|
based on the runas user.
|
|
.TP 6n
|
|
progname=string
|
|
The command name that sudo was run as, typically
|
|
\(Lqsudo\(Rq
|
|
or
|
|
\(Lqsudoedit\(Rq.
|
|
.TP 6n
|
|
prompt=string
|
|
The prompt to use when requesting a password, if specified via
|
|
the
|
|
\fB\-p\fR
|
|
flag.
|
|
.TP 6n
|
|
remote_host=string
|
|
The name of the remote host to run the command on, if specified via
|
|
the
|
|
\fB\-h\fR
|
|
option.
|
|
Support for running the command on a remote host is meant to be implemented
|
|
via a helper program that is executed in place of the user-specified command.
|
|
The
|
|
\fBsudo\fR
|
|
front end is only capable of executing commands on the local host.
|
|
Only available starting with API version 1.4.
|
|
.TP 6n
|
|
run_shell=bool
|
|
Set to true if the user specified the
|
|
\fB\-s\fR
|
|
flag, indicating that the user wishes to run a shell.
|
|
.TP 6n
|
|
runas_group=string
|
|
The group name or gid to run the command as, if specified via
|
|
the
|
|
\fB\-g\fR
|
|
flag.
|
|
.TP 6n
|
|
runas_user=string
|
|
The user name or uid to run the command as, if specified via the
|
|
\fB\-u\fR
|
|
flag.
|
|
.TP 6n
|
|
selinux_role=string
|
|
SELinux role to use when executing the command, if specified by
|
|
the
|
|
\fB\-r\fR
|
|
flag.
|
|
.TP 6n
|
|
selinux_type=string
|
|
SELinux type to use when executing the command, if specified by
|
|
the
|
|
\fB\-t\fR
|
|
flag.
|
|
.TP 6n
|
|
set_home=bool
|
|
Set to true if the user specified the
|
|
\fB\-H\fR
|
|
flag.
|
|
If true, set the
|
|
\fRHOME\fR
|
|
environment variable to the target user's home directory.
|
|
.TP 6n
|
|
sudoedit=bool
|
|
Set to true when the
|
|
\fB\-e\fR
|
|
flag is is specified or if invoked as
|
|
\fBsudoedit\fR.
|
|
The plugin shall substitute an editor into
|
|
\fIargv\fR
|
|
in the
|
|
\fBcheck_policy\fR()
|
|
function or return \-2 with a usage error
|
|
if the plugin does not support
|
|
\fIsudoedit\fR.
|
|
For more information, see the
|
|
\fIcheck_policy\fR
|
|
section.
|
|
.TP 6n
|
|
timeout=string
|
|
User-specified command timeout.
|
|
Not all plugins support command timeouts and the ability for the
|
|
user to set a timeout may be restricted by policy.
|
|
The format of the timeout string is plugin-specific.
|
|
.PP
|
|
Additional settings may be added in the future so the plugin should
|
|
silently ignore settings that it does not recognize.
|
|
.RE
|
|
.TP 6n
|
|
user_info
|
|
A vector of information about the user running the command in the form of
|
|
\(Lqname=value\(Rq
|
|
strings.
|
|
The vector is terminated by a
|
|
\fRNULL\fR
|
|
pointer.
|
|
.sp
|
|
When parsing
|
|
\fIuser_info\fR,
|
|
the plugin should split on the
|
|
\fBfirst\fR
|
|
equal sign
|
|
(\(oq=\(cq)
|
|
since the
|
|
\fIname\fR
|
|
field will never include one
|
|
itself but the
|
|
\fIvalue\fR
|
|
might.
|
|
.PP
|
|
.RS 6n
|
|
.PD 0
|
|
.TP 6n
|
|
cols=int
|
|
The number of columns the user's terminal supports.
|
|
If there is no terminal device available, a default value of 80 is used.
|
|
.PD
|
|
.TP 6n
|
|
cwd=string
|
|
The user's current working directory.
|
|
.TP 6n
|
|
egid=gid_t
|
|
The effective group ID of the user invoking
|
|
\fBsudo\fR.
|
|
.TP 6n
|
|
euid=uid_t
|
|
The effective user ID of the user invoking
|
|
\fBsudo\fR.
|
|
.TP 6n
|
|
gid=gid_t
|
|
The real group ID of the user invoking
|
|
\fBsudo\fR.
|
|
.TP 6n
|
|
groups=list
|
|
The user's supplementary group list formatted as a string of
|
|
comma-separated group IDs.
|
|
.TP 6n
|
|
host=string
|
|
The local machine's hostname as returned by the
|
|
gethostname(2)
|
|
system call.
|
|
.TP 6n
|
|
lines=int
|
|
The number of lines the user's terminal supports.
|
|
If there is
|
|
no terminal device available, a default value of 24 is used.
|
|
.TP 6n
|
|
pgid=int
|
|
The ID of the process group that the running
|
|
\fBsudo\fR
|
|
process is a member of.
|
|
Only available starting with API version 1.2.
|
|
.TP 6n
|
|
pid=int
|
|
The process ID of the running
|
|
\fBsudo\fR
|
|
process.
|
|
Only available starting with API version 1.2.
|
|
.TP 6n
|
|
plugin_options
|
|
Any (non-comment) strings immediately after the plugin path are
|
|
passed as arguments to the plugin.
|
|
These arguments are split on a white space boundary and are passed to
|
|
the plugin in the form of a
|
|
\fRNULL\fR-terminated
|
|
array of strings.
|
|
If no arguments were
|
|
specified,
|
|
\fIplugin_options\fR
|
|
will be the
|
|
\fRNULL\fR
|
|
pointer.
|
|
.sp
|
|
NOTE: the
|
|
\fIplugin_options\fR
|
|
parameter is only available starting with
|
|
API version 1.2.
|
|
A plugin
|
|
\fBmust\fR
|
|
check the API version specified
|
|
by the
|
|
\fBsudo\fR
|
|
front end before using
|
|
\fIplugin_options\fR.
|
|
Failure to do so may result in a crash.
|
|
.TP 6n
|
|
ppid=int
|
|
The parent process ID of the running
|
|
\fBsudo\fR
|
|
process.
|
|
Only available starting with API version 1.2.
|
|
.TP 6n
|
|
sid=int
|
|
The session ID of the running
|
|
\fBsudo\fR
|
|
process or 0 if
|
|
\fBsudo\fR
|
|
is not part of a POSIX job control session.
|
|
Only available starting with API version 1.2.
|
|
.TP 6n
|
|
tcpgid=int
|
|
The ID of the foreground process group associated with the terminal
|
|
device associated with the
|
|
\fBsudo\fR
|
|
process or \-1 if there is no
|
|
terminal present.
|
|
Only available starting with API version 1.2.
|
|
.TP 6n
|
|
tty=string
|
|
The path to the user's terminal device.
|
|
If the user has no terminal device associated with the session,
|
|
the value will be empty, as in
|
|
\(Lq\fRtty=\fR\(Rq.
|
|
.TP 6n
|
|
uid=uid_t
|
|
The real user ID of the user invoking
|
|
\fBsudo\fR.
|
|
.TP 6n
|
|
umask=octal
|
|
The invoking user's file creation mask.
|
|
Only available starting with API version 1.10.
|
|
.TP 6n
|
|
user=string
|
|
The name of the user invoking
|
|
\fBsudo\fR.
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.TP 6n
|
|
user_env
|
|
The user's environment in the form of a
|
|
\fRNULL\fR-terminated vector of
|
|
\(Lqname=value\(Rq
|
|
strings.
|
|
.sp
|
|
When parsing
|
|
\fIuser_env\fR,
|
|
the plugin should split on the
|
|
\fBfirst\fR
|
|
equal sign
|
|
(\(oq=\(cq)
|
|
since the
|
|
\fIname\fR
|
|
field will never include one
|
|
itself but the
|
|
\fIvalue\fR
|
|
might.
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.TP 6n
|
|
close
|
|
.br
|
|
.nf
|
|
.RS 6n
|
|
void (*close)(int exit_status, int error);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBclose\fR()
|
|
function is called when the command being run by
|
|
\fBsudo\fR
|
|
finishes.
|
|
.sp
|
|
The function arguments are as follows:
|
|
.TP 6n
|
|
exit_status
|
|
The command's exit status, as returned by the
|
|
wait(2)
|
|
system call.
|
|
The value of
|
|
\fRexit_status\fR
|
|
is undefined if
|
|
\fRerror\fR
|
|
is non-zero.
|
|
.TP 6n
|
|
error
|
|
.br
|
|
If the command could not be executed, this is set to the value of
|
|
\fRerrno\fR
|
|
set by the
|
|
execve(2)
|
|
system call.
|
|
The plugin is responsible for displaying error information via the
|
|
\fBconversation\fR()
|
|
or
|
|
\fBplugin_printf\fR()
|
|
function.
|
|
If the command was successfully executed, the value of
|
|
\fRerror\fR
|
|
is 0.
|
|
.PP
|
|
If no
|
|
\fBclose\fR()
|
|
function is defined, no I/O logging plugins are loaded,
|
|
and neither the
|
|
\fItimeout\fR
|
|
not
|
|
\fIuse_pty\fR
|
|
options are set in the
|
|
\fRcommand_info\fR
|
|
list, the
|
|
\fBsudo\fR
|
|
front end may execute the command directly instead of running
|
|
it as a child process.
|
|
.RE
|
|
.TP 6n
|
|
show_version
|
|
.nf
|
|
.RS 6n
|
|
int (*show_version)(int verbose);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBshow_version\fR()
|
|
function is called by
|
|
\fBsudo\fR
|
|
when the user specifies
|
|
the
|
|
\fB\-V\fR
|
|
option.
|
|
The plugin may display its version information to the user via the
|
|
\fBconversation\fR()
|
|
or
|
|
\fBplugin_printf\fR()
|
|
function using
|
|
\fRSUDO_CONV_INFO_MSG\fR.
|
|
If the user requests detailed version information, the verbose flag will be set.
|
|
.RE
|
|
.TP 6n
|
|
check_policy
|
|
.nf
|
|
.RS 6n
|
|
int (*check_policy)(int argc, char * const argv[]
|
|
char *env_add[], char **command_info[],
|
|
char **argv_out[], char **user_env_out[]);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBcheck_policy\fR()
|
|
function is called by
|
|
\fBsudo\fR
|
|
to determine
|
|
whether the user is allowed to run the specified commands.
|
|
.sp
|
|
If the
|
|
\fIsudoedit\fR
|
|
option was enabled in the
|
|
\fIsettings\fR
|
|
array
|
|
passed to the
|
|
\fBopen\fR()
|
|
function, the user has requested
|
|
\fIsudoedit\fR
|
|
mode.
|
|
\fIsudoedit\fR
|
|
is a mechanism for editing one or more files
|
|
where an editor is run with the user's credentials instead of with
|
|
elevated privileges.
|
|
\fBsudo\fR
|
|
achieves this by creating user-writable
|
|
temporary copies of the files to be edited and then overwriting the
|
|
originals with the temporary copies after editing is complete.
|
|
If the plugin supports
|
|
\fIsudoedit\fR,
|
|
it should choose the editor to be used, potentially from a variable
|
|
in the user's environment, such as
|
|
\fREDITOR\fR,
|
|
and include it in
|
|
\fIargv_out\fR
|
|
(note that environment
|
|
variables may include command line flags).
|
|
The files to be edited should be copied from
|
|
\fIargv\fR
|
|
into
|
|
\fIargv_out\fR,
|
|
separated from the
|
|
editor and its arguments by a
|
|
\(Lq\fR--\fR\(Rq
|
|
element.
|
|
The
|
|
\(Lq\fR--\fR\(Rq
|
|
will
|
|
be removed by
|
|
\fBsudo\fR
|
|
before the editor is executed.
|
|
The plugin should also set
|
|
\fIsudoedit=true\fR
|
|
in the
|
|
\fIcommand_info\fR
|
|
list.
|
|
.sp
|
|
The
|
|
\fBcheck_policy\fR()
|
|
function returns 1 if the command is allowed,
|
|
0 if not allowed, \-1 for a general error, or \-2 for a usage error
|
|
or if
|
|
\fIsudoedit\fR
|
|
was specified but is unsupported by the plugin.
|
|
In the latter case,
|
|
\fBsudo\fR
|
|
will print a usage message before it
|
|
exits.
|
|
If an error occurs, the plugin may optionally call the
|
|
\fBconversation\fR()
|
|
or
|
|
\fBplugin_printf\fR()
|
|
function with
|
|
\fRSUDO_CONF_ERROR_MSG\fR
|
|
to present additional error information to the user.
|
|
.sp
|
|
The function arguments are as follows:
|
|
.TP 6n
|
|
argc
|
|
The number of elements in
|
|
\fIargv\fR,
|
|
not counting the final
|
|
\fRNULL\fR
|
|
pointer.
|
|
.TP 6n
|
|
argv
|
|
The argument vector describing the command the user wishes to run,
|
|
in the same form as what would be passed to the
|
|
execve(2)
|
|
system call.
|
|
The vector is terminated by a
|
|
\fRNULL\fR
|
|
pointer.
|
|
.TP 6n
|
|
env_add
|
|
Additional environment variables specified by the user on the command
|
|
line in the form of a
|
|
\fRNULL\fR-terminated
|
|
vector of
|
|
\(Lqname=value\(Rq
|
|
strings.
|
|
The plugin may reject the command if one or more variables
|
|
are not allowed to be set, or it may silently ignore such variables.
|
|
.sp
|
|
When parsing
|
|
\fIenv_add\fR,
|
|
the plugin should split on the
|
|
\fBfirst\fR
|
|
equal sign
|
|
(\(oq=\(cq)
|
|
since the
|
|
\fIname\fR
|
|
field will never include one
|
|
itself but the
|
|
\fIvalue\fR
|
|
might.
|
|
.TP 6n
|
|
command_info
|
|
Information about the command being run in the form of
|
|
\(Lqname=value\(Rq
|
|
strings.
|
|
These values are used by
|
|
\fBsudo\fR
|
|
to set the execution
|
|
environment when running a command.
|
|
The plugin is responsible for creating and populating the vector,
|
|
which must be terminated with a
|
|
\fRNULL\fR
|
|
pointer.
|
|
The following values are recognized by
|
|
\fBsudo\fR:
|
|
.PP
|
|
.RS 6n
|
|
.PD 0
|
|
.TP 6n
|
|
chroot=string
|
|
The root directory to use when running the command.
|
|
.PD
|
|
.TP 6n
|
|
closefrom=number
|
|
If specified,
|
|
\fBsudo\fR
|
|
will close all files descriptors with a value
|
|
of
|
|
\fInumber\fR
|
|
or higher.
|
|
.TP 6n
|
|
command=string
|
|
Fully qualified path to the command to be executed.
|
|
.TP 6n
|
|
cwd=string
|
|
The current working directory to change to when executing the command.
|
|
.TP 6n
|
|
exec_background=bool
|
|
By default,
|
|
\fBsudo\fR
|
|
runs a command as the foreground process as long as
|
|
\fBsudo\fR
|
|
itself is running in the foreground.
|
|
When
|
|
\fIexec_background\fR
|
|
is enabled and the command is being run in a pty (due to I/O logging
|
|
or the
|
|
\fIuse_pty\fR
|
|
setting), the command will be run as a background process.
|
|
Attempts to read from the controlling terminal (or to change terminal
|
|
settings) will result in the command being suspended with the
|
|
\fRSIGTTIN\fR
|
|
signal (or
|
|
\fRSIGTTOU\fR
|
|
in the case of terminal settings).
|
|
If this happens when
|
|
\fBsudo\fR
|
|
is a foreground process, the command will be granted the controlling terminal
|
|
and resumed in the foreground with no user intervention required.
|
|
The advantage of initially running the command in the background is that
|
|
\fBsudo\fR
|
|
need not read from the terminal unless the command explicitly requests it.
|
|
Otherwise, any terminal input must be passed to the command, whether it
|
|
has required it or not (the kernel buffers terminals so it is not possible
|
|
to tell whether the command really wants the input).
|
|
This is different from historic
|
|
\fIsudo\fR
|
|
behavior or when the command is not being run in a pty.
|
|
.sp
|
|
For this to work seamlessly, the operating system must support the
|
|
automatic restarting of system calls.
|
|
Unfortunately, not all operating systems do this by default,
|
|
and even those that do may have bugs.
|
|
For example, Mac OS X fails to restart the
|
|
\fBtcgetattr\fR()
|
|
and
|
|
\fBtcsetattr\fR()
|
|
system calls (this is a bug in Mac OS X).
|
|
Furthermore, because this behavior depends on the command stopping with the
|
|
\fRSIGTTIN\fR
|
|
or
|
|
\fRSIGTTOU\fR
|
|
signals, programs that catch these signals and suspend themselves
|
|
with a different signal (usually
|
|
\fRSIGTOP\fR)
|
|
will not be automatically foregrounded.
|
|
Some versions of the linux
|
|
su(1)
|
|
command behave this way.
|
|
Because of this, a plugin should not set
|
|
\fIexec_background\fR
|
|
unless it is explicitly enabled by the administrator and there should
|
|
be a way to enabled or disable it on a per-command basis.
|
|
.sp
|
|
This setting has no effect unless I/O logging is enabled or
|
|
\fIuse_pty\fR
|
|
is enabled.
|
|
.TP 6n
|
|
execfd=number
|
|
If specified,
|
|
\fBsudo\fR
|
|
will use the
|
|
fexecve(2)
|
|
system call to execute the command instead of
|
|
execve(2).
|
|
The specified
|
|
\fInumber\fR
|
|
must refer to an open file descriptor.
|
|
.TP 6n
|
|
iolog_compress=bool
|
|
Set to true if the I/O logging plugins, if any, should compress the
|
|
log data.
|
|
This is a hint to the I/O logging plugin which may choose to ignore it.
|
|
.TP 6n
|
|
iolog_group=string
|
|
The group that will own newly created I/O log files and directories.
|
|
This is a hint to the I/O logging plugin which may choose to ignore it.
|
|
.TP 6n
|
|
iolog_mode=octal
|
|
The file permision mode to use when creating I/O log files and directories.
|
|
This is a hint to the I/O logging plugin which may choose to ignore it.
|
|
.TP 6n
|
|
iolog_user=string
|
|
The user that will own newly created I/O log files and directories.
|
|
This is a hint to the I/O logging plugin which may choose to ignore it.
|
|
.TP 6n
|
|
iolog_path=string
|
|
Fully qualified path to the file or directory in which I/O log is
|
|
to be stored.
|
|
This is a hint to the I/O logging plugin which may choose to ignore it.
|
|
If no I/O logging plugin is loaded, this setting has no effect.
|
|
.TP 6n
|
|
iolog_stdin=bool
|
|
Set to true if the I/O logging plugins, if any, should log the
|
|
standard input if it is not connected to a terminal device.
|
|
This is a hint to the I/O logging plugin which may choose to ignore it.
|
|
.TP 6n
|
|
iolog_stdout=bool
|
|
Set to true if the I/O logging plugins, if any, should log the
|
|
standard output if it is not connected to a terminal device.
|
|
This is a hint to the I/O logging plugin which may choose to ignore it.
|
|
.TP 6n
|
|
iolog_stderr=bool
|
|
Set to true if the I/O logging plugins, if any, should log the
|
|
standard error if it is not connected to a terminal device.
|
|
This is a hint to the I/O logging plugin which may choose to ignore it.
|
|
.TP 6n
|
|
iolog_ttyin=bool
|
|
Set to true if the I/O logging plugins, if any, should log all
|
|
terminal input.
|
|
This only includes input typed by the user and not from a pipe or
|
|
redirected from a file.
|
|
This is a hint to the I/O logging plugin which may choose to ignore it.
|
|
.TP 6n
|
|
iolog_ttyout=bool
|
|
Set to true if the I/O logging plugins, if any, should log all
|
|
terminal output.
|
|
This only includes output to the screen, not output to a pipe or file.
|
|
This is a hint to the I/O logging plugin which may choose to ignore it.
|
|
.TP 6n
|
|
login_class=string
|
|
BSD login class to use when setting resource limits and nice value
|
|
(optional).
|
|
This option is only set on systems that support login classes.
|
|
.TP 6n
|
|
nice=int
|
|
Nice value (priority) to use when executing the command.
|
|
The nice value, if specified, overrides the priority associated with the
|
|
\fIlogin_class\fR
|
|
on BSD systems.
|
|
.TP 6n
|
|
noexec=bool
|
|
If set, prevent the command from executing other programs.
|
|
.TP 6n
|
|
preserve_fds=list
|
|
A comma-separated list of file descriptors that should be
|
|
preserved, regardless of the value of the
|
|
\fIclosefrom\fR
|
|
setting.
|
|
Only available starting with API version 1.5.
|
|
.TP 6n
|
|
preserve_groups=bool
|
|
If set,
|
|
\fBsudo\fR
|
|
will preserve the user's group vector instead of
|
|
initializing the group vector based on
|
|
\fRrunas_user\fR.
|
|
.TP 6n
|
|
runas_egid=gid
|
|
Effective group ID to run the command as.
|
|
If not specified, the value of
|
|
\fIrunas_gid\fR
|
|
is used.
|
|
.TP 6n
|
|
runas_euid=uid
|
|
Effective user ID to run the command as.
|
|
If not specified, the value of
|
|
\fIrunas_uid\fR
|
|
is used.
|
|
.TP 6n
|
|
runas_gid=gid
|
|
Group ID to run the command as.
|
|
.TP 6n
|
|
runas_groups=list
|
|
The supplementary group vector to use for the command in the form
|
|
of a comma-separated list of group IDs.
|
|
If
|
|
\fIpreserve_groups\fR
|
|
is set, this option is ignored.
|
|
.TP 6n
|
|
runas_uid=uid
|
|
User ID to run the command as.
|
|
.TP 6n
|
|
selinux_role=string
|
|
SELinux role to use when executing the command.
|
|
.TP 6n
|
|
selinux_type=string
|
|
SELinux type to use when executing the command.
|
|
.TP 6n
|
|
set_utmp=bool
|
|
Create a utmp (or utmpx) entry when a pseudo-tty is allocated.
|
|
By default, the new entry will be a copy of the user's existing utmp
|
|
entry (if any), with the tty, time, type and pid fields updated.
|
|
.TP 6n
|
|
sudoedit=bool
|
|
Set to true when in
|
|
\fIsudoedit\fR
|
|
mode.
|
|
The plugin may enable
|
|
\fIsudoedit\fR
|
|
mode even if
|
|
\fBsudo\fR
|
|
was not invoked as
|
|
\fBsudoedit\fR.
|
|
This allows the plugin to perform command substitution and transparently
|
|
enable
|
|
\fIsudoedit\fR
|
|
when the user attempts to run an editor.
|
|
.TP 6n
|
|
sudoedit_checkdir=bool
|
|
Set to false to disable directory writability checks in
|
|
\fBsudoedit\fR.
|
|
By default,
|
|
\fBsudoedit\fR
|
|
1.8.16 and higher will check all directory components of the path to be
|
|
edited for writability by the invoking user.
|
|
Symbolic links will not be followed in writable directories and
|
|
\fBsudoedit\fR
|
|
will refuse to edit a file located in a writable directory.
|
|
These restrictions are not enforced when
|
|
\fBsudoedit\fR
|
|
is run by root.
|
|
The
|
|
\fIsudoedit_follow\fR
|
|
option can be set to false to disable this check.
|
|
Only available starting with API version 1.8.
|
|
.TP 6n
|
|
sudoedit_follow=bool
|
|
Set to true to allow
|
|
\fBsudoedit\fR
|
|
to edit files that are symbolic links.
|
|
By default,
|
|
\fBsudoedit\fR
|
|
1.8.15 and higher will refuse to open a symbolic link.
|
|
The
|
|
\fIsudoedit_follow\fR
|
|
option can be used to restore the older behavior and allow
|
|
\fBsudoedit\fR
|
|
to open symbolic links.
|
|
Only available starting with API version 1.8.
|
|
.TP 6n
|
|
timeout=int
|
|
Command timeout.
|
|
If non-zero then when the timeout expires the command will be killed.
|
|
.TP 6n
|
|
umask=octal
|
|
The file creation mask to use when executing the command.
|
|
.TP 6n
|
|
use_pty=bool
|
|
Allocate a pseudo-tty to run the command in, regardless of whether
|
|
or not I/O logging is in use.
|
|
By default,
|
|
\fBsudo\fR
|
|
will only run
|
|
the command in a pty when an I/O log plugin is loaded.
|
|
.TP 6n
|
|
utmp_user=string
|
|
User name to use when constructing a new utmp (or utmpx) entry when
|
|
\fIset_utmp\fR
|
|
is enabled.
|
|
This option can be used to set the user field in the utmp entry to
|
|
the user the command runs as rather than the invoking user.
|
|
If not set,
|
|
\fBsudo\fR
|
|
will base the new entry on
|
|
the invoking user's existing entry.
|
|
.PP
|
|
Unsupported values will be ignored.
|
|
.RE
|
|
.TP 6n
|
|
argv_out
|
|
The
|
|
\fRNULL\fR-terminated
|
|
argument vector to pass to the
|
|
execve(2)
|
|
system call when executing the command.
|
|
The plugin is responsible for allocating and populating the vector.
|
|
.TP 6n
|
|
user_env_out
|
|
The
|
|
\fRNULL\fR-terminated
|
|
environment vector to use when executing the command.
|
|
The plugin is responsible for allocating and populating the vector.
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.TP 6n
|
|
list
|
|
.nf
|
|
.RS 6n
|
|
int (*list)(int verbose, const char *list_user,
|
|
int argc, char * const argv[]);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
List available privileges for the invoking user.
|
|
Returns 1 on success, 0 on failure and \-1 on error.
|
|
On error, the plugin may optionally call the
|
|
\fBconversation\fR()
|
|
or
|
|
\fBplugin_printf\fR()
|
|
function with
|
|
\fRSUDO_CONF_ERROR_MSG\fR
|
|
to present additional error information to
|
|
the user.
|
|
.sp
|
|
Privileges should be output via the
|
|
\fBconversation\fR()
|
|
or
|
|
\fBplugin_printf\fR()
|
|
function using
|
|
\fRSUDO_CONV_INFO_MSG\fR,
|
|
.TP 6n
|
|
verbose
|
|
Flag indicating whether to list in verbose mode or not.
|
|
.TP 6n
|
|
list_user
|
|
The name of a different user to list privileges for if the policy
|
|
allows it.
|
|
If
|
|
\fRNULL\fR,
|
|
the plugin should list the privileges of the invoking user.
|
|
.TP 6n
|
|
argc
|
|
The number of elements in
|
|
\fIargv\fR,
|
|
not counting the final
|
|
\fRNULL\fR
|
|
pointer.
|
|
.TP 6n
|
|
argv
|
|
If
|
|
non-\fRNULL\fR,
|
|
an argument vector describing a command the user
|
|
wishes to check against the policy in the same form as what would
|
|
be passed to the
|
|
execve(2)
|
|
system call.
|
|
If the command is permitted by the policy, the fully-qualified path
|
|
to the command should be displayed along with any command line arguments.
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.TP 6n
|
|
validate
|
|
.nf
|
|
.RS 6n
|
|
int (*validate)(void);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBvalidate\fR()
|
|
function is called when
|
|
\fBsudo\fR
|
|
is run with the
|
|
\fB\-v\fR
|
|
flag.
|
|
For policy plugins such as
|
|
\fBsudoers\fR
|
|
that cache
|
|
authentication credentials, this function will validate and cache
|
|
the credentials.
|
|
.sp
|
|
The
|
|
\fBvalidate\fR()
|
|
function should be
|
|
\fRNULL\fR
|
|
if the plugin does not support credential caching.
|
|
.sp
|
|
Returns 1 on success, 0 on failure and \-1 on error.
|
|
On error, the plugin may optionally call the
|
|
\fBconversation\fR()
|
|
or
|
|
\fBplugin_printf\fR()
|
|
function with
|
|
\fRSUDO_CONF_ERROR_MSG\fR
|
|
to present additional
|
|
error information to the user.
|
|
.RE
|
|
.TP 6n
|
|
invalidate
|
|
.nf
|
|
.RS 6n
|
|
void (*invalidate)(int remove);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBinvalidate\fR()
|
|
function is called when
|
|
\fBsudo\fR
|
|
is called with
|
|
the
|
|
\fB\-k\fR
|
|
or
|
|
\fB\-K\fR
|
|
flag.
|
|
For policy plugins such as
|
|
\fBsudoers\fR
|
|
that
|
|
cache authentication credentials, this function will invalidate the
|
|
credentials.
|
|
If the
|
|
\fIremove\fR
|
|
flag is set, the plugin may remove
|
|
the credentials instead of simply invalidating them.
|
|
.sp
|
|
The
|
|
\fBinvalidate\fR()
|
|
function should be
|
|
\fRNULL\fR
|
|
if the plugin does not support credential caching.
|
|
.RE
|
|
.TP 6n
|
|
init_session
|
|
.nf
|
|
.RS 6n
|
|
int (*init_session)(struct passwd *pwd, char **user_envp[);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBinit_session\fR()
|
|
function is called before
|
|
\fBsudo\fR
|
|
sets up the
|
|
execution environment for the command.
|
|
It is run in the parent
|
|
\fBsudo\fR
|
|
process and before any uid or gid changes.
|
|
This can be used to perform session setup that is not supported by
|
|
\fIcommand_info\fR,
|
|
such as opening the PAM session.
|
|
The
|
|
\fBclose\fR()
|
|
function can be
|
|
used to tear down the session that was opened by
|
|
\fRinit_session\fR.
|
|
.sp
|
|
The
|
|
\fIpwd\fR
|
|
argument points to a passwd struct for the user the
|
|
command will be run as if the uid the command will run as was found
|
|
in the password database, otherwise it will be
|
|
\fRNULL\fR.
|
|
.sp
|
|
The
|
|
\fIuser_env\fR
|
|
argument points to the environment the command will
|
|
run in, in the form of a
|
|
\fRNULL\fR-terminated
|
|
vector of
|
|
\(Lqname=value\(Rq
|
|
strings.
|
|
This is the same string passed back to the front end via
|
|
the Policy Plugin's
|
|
\fIuser_env_out\fR
|
|
parameter.
|
|
If the
|
|
\fBinit_session\fR()
|
|
function needs to modify the user environment, it should update the
|
|
pointer stored in
|
|
\fIuser_env\fR.
|
|
The expected use case is to merge the contents of the PAM environment
|
|
(if any) with the contents of
|
|
\fIuser_env\fR.
|
|
NOTE: the
|
|
\fIuser_env\fR
|
|
parameter is only available
|
|
starting with API version 1.2.
|
|
A plugin
|
|
\fBmust\fR
|
|
check the API
|
|
version specified by the
|
|
\fBsudo\fR
|
|
front end before using
|
|
\fIuser_env\fR.
|
|
Failure to do so may result in a crash.
|
|
.sp
|
|
Returns 1 on success, 0 on failure and \-1 on error.
|
|
On error, the plugin may optionally call the
|
|
\fBconversation\fR()
|
|
or
|
|
\fBplugin_printf\fR()
|
|
function with
|
|
\fRSUDO_CONF_ERROR_MSG\fR
|
|
to present additional
|
|
error information to the user.
|
|
.RE
|
|
.TP 6n
|
|
register_hooks
|
|
.nf
|
|
.RS 6n
|
|
void (*register_hooks)(int version,
|
|
int (*register_hook)(struct sudo_hook *hook));
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBregister_hooks\fR()
|
|
function is called by the sudo front end to
|
|
register any hooks the plugin needs.
|
|
If the plugin does not support hooks,
|
|
\fRregister_hooks\fR
|
|
should be set to the
|
|
\fRNULL\fR
|
|
pointer.
|
|
.sp
|
|
The
|
|
\fIversion\fR
|
|
argument describes the version of the hooks API
|
|
supported by the
|
|
\fBsudo\fR
|
|
front end.
|
|
.sp
|
|
The
|
|
\fBregister_hook\fR()
|
|
function should be used to register any supported
|
|
hooks the plugin needs.
|
|
It returns 0 on success, 1 if the hook type is not supported and \-1
|
|
if the major version in
|
|
\fRstruct hook\fR
|
|
does not match the front end's major hook API version.
|
|
.sp
|
|
See the
|
|
\fIHook function API\fR
|
|
section below for more information
|
|
about hooks.
|
|
.sp
|
|
NOTE: the
|
|
\fBregister_hooks\fR()
|
|
function is only available starting
|
|
with API version 1.2.
|
|
If the
|
|
\fBsudo\fR
|
|
front end doesn't support API
|
|
version 1.2 or higher,
|
|
\fRregister_hooks\fR
|
|
will not be called.
|
|
.RE
|
|
.TP 6n
|
|
deregister_hooks
|
|
.nf
|
|
.RS 6n
|
|
void (*deregister_hooks)(int version,
|
|
int (*deregister_hook)(struct sudo_hook *hook));
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBderegister_hooks\fR()
|
|
function is called by the sudo front end
|
|
to deregister any hooks the plugin has registered.
|
|
If the plugin does not support hooks,
|
|
\fRderegister_hooks\fR
|
|
should be set to the
|
|
\fRNULL\fR
|
|
pointer.
|
|
.sp
|
|
The
|
|
\fIversion\fR
|
|
argument describes the version of the hooks API
|
|
supported by the
|
|
\fBsudo\fR
|
|
front end.
|
|
.sp
|
|
The
|
|
\fBderegister_hook\fR()
|
|
function should be used to deregister any
|
|
hooks that were put in place by the
|
|
\fBregister_hook\fR()
|
|
function.
|
|
If the plugin tries to deregister a hook that the front end does not support,
|
|
\fRderegister_hook\fR
|
|
will return an error.
|
|
.sp
|
|
See the
|
|
\fIHook function API\fR
|
|
section below for more information
|
|
about hooks.
|
|
.sp
|
|
NOTE: the
|
|
\fBderegister_hooks\fR()
|
|
function is only available starting
|
|
with API version 1.2.
|
|
If the
|
|
\fBsudo\fR
|
|
front end doesn't support API
|
|
version 1.2 or higher,
|
|
\fRderegister_hooks\fR
|
|
will not be called.
|
|
.RE
|
|
.PP
|
|
\fIPolicy Plugin Version Macros\fR
|
|
.nf
|
|
.sp
|
|
.RS 0n
|
|
/* Plugin API version major/minor. */
|
|
#define SUDO_API_VERSION_MAJOR 1
|
|
#define SUDO_API_VERSION_MINOR 2
|
|
#define SUDO_API_MKVERSION(x, y) ((x << 16) | y)
|
|
#define SUDO_API_VERSION SUDO_API_MKVERSION(SUDO_API_VERSION_MAJOR,\e
|
|
SUDO_API_VERSION_MINOR)
|
|
|
|
/* Getters and setters for API version */
|
|
#define SUDO_API_VERSION_GET_MAJOR(v) ((v) >> 16)
|
|
#define SUDO_API_VERSION_GET_MINOR(v) ((v) & 0xffff)
|
|
#define SUDO_API_VERSION_SET_MAJOR(vp, n) do { \e
|
|
*(vp) = (*(vp) & 0x0000ffff) | ((n) << 16); \e
|
|
} while(0)
|
|
#define SUDO_API_VERSION_SET_MINOR(vp, n) do { \e
|
|
*(vp) = (*(vp) & 0xffff0000) | (n); \e
|
|
} while(0)
|
|
.RE
|
|
.fi
|
|
.SS "I/O plugin API"
|
|
.nf
|
|
.RS 0n
|
|
struct io_plugin {
|
|
#define SUDO_IO_PLUGIN 2
|
|
unsigned int type; /* always SUDO_IO_PLUGIN */
|
|
unsigned int version; /* always SUDO_API_VERSION */
|
|
int (*open)(unsigned int version, sudo_conv_t conversation,
|
|
sudo_printf_t plugin_printf, char * const settings[],
|
|
char * const user_info[], char * const command_info[],
|
|
int argc, char * const argv[], char * const user_env[],
|
|
char * const plugin_options[]);
|
|
void (*close)(int exit_status, int error); /* wait status or error */
|
|
int (*show_version)(int verbose);
|
|
int (*log_ttyin)(const char *buf, unsigned int len);
|
|
int (*log_ttyout)(const char *buf, unsigned int len);
|
|
int (*log_stdin)(const char *buf, unsigned int len);
|
|
int (*log_stdout)(const char *buf, unsigned int len);
|
|
int (*log_stderr)(const char *buf, unsigned int len);
|
|
void (*register_hooks)(int version,
|
|
int (*register_hook)(struct sudo_hook *hook));
|
|
void (*deregister_hooks)(int version,
|
|
int (*deregister_hook)(struct sudo_hook *hook));
|
|
};
|
|
.RE
|
|
.fi
|
|
.PP
|
|
When an I/O plugin is loaded,
|
|
\fBsudo\fR
|
|
runs the command in a pseudo-tty.
|
|
This makes it possible to log the input and output from the user's
|
|
session.
|
|
If any of the standard input, standard output or standard error do not
|
|
correspond to a tty,
|
|
\fBsudo\fR
|
|
will open a pipe to capture
|
|
the I/O for logging before passing it on.
|
|
.PP
|
|
The log_ttyin function receives the raw user input from the terminal
|
|
device (note that this will include input even when echo is disabled,
|
|
such as when a password is read).
|
|
The log_ttyout function receives output from the pseudo-tty that is
|
|
suitable for replaying the user's session at a later time.
|
|
The
|
|
\fBlog_stdin\fR(),
|
|
\fBlog_stdout\fR()
|
|
and
|
|
\fBlog_stderr\fR()
|
|
functions are only called if the standard input, standard output
|
|
or standard error respectively correspond to something other than
|
|
a tty.
|
|
.PP
|
|
Any of the logging functions may be set to the
|
|
\fRNULL\fR
|
|
pointer if no logging is to be performed.
|
|
If the open function returns 0, no I/O will be sent to the plugin.
|
|
.PP
|
|
If a logging function returns an error
|
|
(\-1),
|
|
the running command will be terminated and all of the plugin's logging
|
|
functions will be disabled.
|
|
Other I/O logging plugins will still receive any remaining
|
|
input or output that has not yet been processed.
|
|
.PP
|
|
If an input logging function rejects the data by returning 0, the
|
|
command will be terminated and the data will not be passed to the
|
|
command, though it will still be sent to any other I/O logging plugins.
|
|
If an output logging function rejects the data by returning 0, the
|
|
command will be terminated and the data will not be written to the
|
|
terminal, though it will still be sent to any other I/O logging plugins.
|
|
.PP
|
|
The io_plugin struct has the following fields:
|
|
.TP 6n
|
|
type
|
|
The
|
|
\fRtype\fR
|
|
field should always be set to
|
|
\fRSUDO_IO_PLUGIN\fR.
|
|
.TP 6n
|
|
version
|
|
The
|
|
\fRversion\fR
|
|
field should be set to
|
|
\fRSUDO_API_VERSION\fR.
|
|
.sp
|
|
This allows
|
|
\fBsudo\fR
|
|
to determine the API version the plugin was
|
|
built against.
|
|
.TP 6n
|
|
open
|
|
.nf
|
|
.RS 6n
|
|
int (*open)(unsigned int version, sudo_conv_t conversation,
|
|
sudo_printf_t plugin_printf, char * const settings[],
|
|
char * const user_info[], int argc, char * const argv[],
|
|
char * const user_env[], char * const plugin_options[]);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBopen\fR()
|
|
function is run before the
|
|
\fBlog_ttyin\fR(),
|
|
\fBlog_ttyout\fR(),
|
|
\fBlog_stdin\fR(),
|
|
\fBlog_stdout\fR(),
|
|
\fBlog_stderr\fR(),
|
|
or
|
|
\fBshow_version\fR()
|
|
functions are called.
|
|
It is only called if the version is being requested or if the
|
|
policy plugin's
|
|
\fBcheck_policy\fR()
|
|
function has returned successfully.
|
|
It returns 1 on success, 0 on failure, \-1 if a general error occurred,
|
|
or \-2 if there was a usage error.
|
|
In the latter case,
|
|
\fBsudo\fR
|
|
will print a usage message before it exits.
|
|
If an error occurs, the plugin may optionally call the
|
|
\fBconversation\fR()
|
|
or
|
|
\fBplugin_printf\fR()
|
|
function with
|
|
\fRSUDO_CONF_ERROR_MSG\fR
|
|
to present
|
|
additional error information to the user.
|
|
.sp
|
|
The function arguments are as follows:
|
|
.TP 6n
|
|
version
|
|
The version passed in by
|
|
\fBsudo\fR
|
|
allows the plugin to determine the
|
|
major and minor version number of the plugin API supported by
|
|
\fBsudo\fR.
|
|
.TP 6n
|
|
conversation
|
|
A pointer to the
|
|
\fBconversation\fR()
|
|
function that may be used by the
|
|
\fBshow_version\fR()
|
|
function to display version information (see
|
|
\fBshow_version\fR()
|
|
below).
|
|
The
|
|
\fBconversation\fR()
|
|
function may also be used to display additional error message to the user.
|
|
The
|
|
\fBconversation\fR()
|
|
function returns 0 on success and \-1 on failure.
|
|
.TP 6n
|
|
plugin_printf
|
|
A pointer to a
|
|
\fBprintf\fR()-style
|
|
function that may be used by the
|
|
\fBshow_version\fR()
|
|
function to display version information (see
|
|
show_version below).
|
|
The
|
|
\fBplugin_printf\fR()
|
|
function may also be used to display additional error message to the user.
|
|
The
|
|
\fBplugin_printf\fR()
|
|
function returns number of characters printed on success and \-1 on failure.
|
|
.TP 6n
|
|
settings
|
|
A vector of user-supplied
|
|
\fBsudo\fR
|
|
settings in the form of
|
|
\(Lqname=value\(Rq
|
|
strings.
|
|
The vector is terminated by a
|
|
\fRNULL\fR
|
|
pointer.
|
|
These settings correspond to flags the user specified when running
|
|
\fBsudo\fR.
|
|
As such, they will only be present when the corresponding flag has
|
|
been specified on the command line.
|
|
.sp
|
|
When parsing
|
|
\fIsettings\fR,
|
|
the plugin should split on the
|
|
\fBfirst\fR
|
|
equal sign
|
|
(\(oq=\(cq)
|
|
since the
|
|
\fIname\fR
|
|
field will never include one
|
|
itself but the
|
|
\fIvalue\fR
|
|
might.
|
|
.sp
|
|
See the
|
|
\fIPolicy plugin API\fR
|
|
section for a list of all possible settings.
|
|
.TP 6n
|
|
user_info
|
|
A vector of information about the user running the command in the form of
|
|
\(Lqname=value\(Rq
|
|
strings.
|
|
The vector is terminated by a
|
|
\fRNULL\fR
|
|
pointer.
|
|
.sp
|
|
When parsing
|
|
\fIuser_info\fR,
|
|
the plugin should split on the
|
|
\fBfirst\fR
|
|
equal sign
|
|
(\(oq=\(cq)
|
|
since the
|
|
\fIname\fR
|
|
field will never include one
|
|
itself but the
|
|
\fIvalue\fR
|
|
might.
|
|
.sp
|
|
See the
|
|
\fIPolicy plugin API\fR
|
|
section for a list of all possible strings.
|
|
.TP 6n
|
|
argc
|
|
The number of elements in
|
|
\fIargv\fR,
|
|
not counting the final
|
|
\fRNULL\fR
|
|
pointer.
|
|
.TP 6n
|
|
argv
|
|
If
|
|
non-\fRNULL\fR,
|
|
an argument vector describing a command the user
|
|
wishes to run in the same form as what would be passed to the
|
|
execve(2)
|
|
system call.
|
|
.TP 6n
|
|
user_env
|
|
The user's environment in the form of a
|
|
\fRNULL\fR-terminated
|
|
vector of
|
|
\(Lqname=value\(Rq
|
|
strings.
|
|
.sp
|
|
When parsing
|
|
\fIuser_env\fR,
|
|
the plugin should split on the
|
|
\fBfirst\fR
|
|
equal sign
|
|
(\(oq=\(cq)
|
|
since the
|
|
\fIname\fR
|
|
field will never include one
|
|
itself but the
|
|
\fIvalue\fR
|
|
might.
|
|
.TP 6n
|
|
plugin_options
|
|
Any (non-comment) strings immediately after the plugin path are
|
|
treated as arguments to the plugin.
|
|
These arguments are split on a white space boundary and are passed to
|
|
the plugin in the form of a
|
|
\fRNULL\fR-terminated
|
|
array of strings.
|
|
If no arguments were specified,
|
|
\fIplugin_options\fR
|
|
will be the
|
|
\fRNULL\fR
|
|
pointer.
|
|
.sp
|
|
NOTE: the
|
|
\fIplugin_options\fR
|
|
parameter is only available starting with
|
|
API version 1.2.
|
|
A plugin
|
|
\fBmust\fR
|
|
check the API version specified
|
|
by the
|
|
\fBsudo\fR
|
|
front end before using
|
|
\fIplugin_options\fR.
|
|
Failure to do so may result in a crash.
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.TP 6n
|
|
close
|
|
.br
|
|
.nf
|
|
.RS 6n
|
|
void (*close)(int exit_status, int error);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBclose\fR()
|
|
function is called when the command being run by
|
|
\fBsudo\fR
|
|
finishes.
|
|
.sp
|
|
The function arguments are as follows:
|
|
.TP 6n
|
|
exit_status
|
|
The command's exit status, as returned by the
|
|
wait(2)
|
|
system call.
|
|
The value of
|
|
\fRexit_status\fR
|
|
is undefined if
|
|
\fRerror\fR
|
|
is non-zero.
|
|
.TP 6n
|
|
error
|
|
.br
|
|
If the command could not be executed, this is set to the value of
|
|
\fRerrno\fR
|
|
set by the
|
|
execve(2)
|
|
system call.
|
|
If the command was successfully executed, the value of
|
|
\fRerror\fR
|
|
is 0.
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.TP 6n
|
|
show_version
|
|
.nf
|
|
.RS 6n
|
|
int (*show_version)(int verbose);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBshow_version\fR()
|
|
function is called by
|
|
\fBsudo\fR
|
|
when the user specifies
|
|
the
|
|
\fB\-V\fR
|
|
option.
|
|
The plugin may display its version information to the user via the
|
|
\fBconversation\fR()
|
|
or
|
|
\fBplugin_printf\fR()
|
|
function using
|
|
\fRSUDO_CONV_INFO_MSG\fR.
|
|
If the user requests detailed version information, the verbose flag will be set.
|
|
.RE
|
|
.TP 6n
|
|
log_ttyin
|
|
.nf
|
|
.RS 6n
|
|
int (*log_ttyin)(const char *buf, unsigned int len);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBlog_ttyin\fR()
|
|
function is called whenever data can be read from
|
|
the user but before it is passed to the running command.
|
|
This allows the plugin to reject data if it chooses to (for instance
|
|
if the input contains banned content).
|
|
Returns 1 if the data should be passed to the command, 0 if the data
|
|
is rejected (which will terminate the running command) or \-1 if an
|
|
error occurred.
|
|
.sp
|
|
The function arguments are as follows:
|
|
.TP 6n
|
|
buf
|
|
The buffer containing user input.
|
|
.TP 6n
|
|
len
|
|
The length of
|
|
\fIbuf\fR
|
|
in bytes.
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.TP 6n
|
|
log_ttyout
|
|
.nf
|
|
.RS 6n
|
|
int (*log_ttyout)(const char *buf, unsigned int len);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBlog_ttyout\fR()
|
|
function is called whenever data can be read from
|
|
the command but before it is written to the user's terminal.
|
|
This allows the plugin to reject data if it chooses to (for instance
|
|
if the output contains banned content).
|
|
Returns 1 if the data should be passed to the user, 0 if the data is rejected
|
|
(which will terminate the running command) or \-1 if an error occurred.
|
|
.sp
|
|
The function arguments are as follows:
|
|
.TP 6n
|
|
buf
|
|
The buffer containing command output.
|
|
.TP 6n
|
|
len
|
|
The length of
|
|
\fIbuf\fR
|
|
in bytes.
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.TP 6n
|
|
log_stdin
|
|
.nf
|
|
.RS 6n
|
|
int (*log_stdin)(const char *buf, unsigned int len);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBlog_stdin\fR()
|
|
function is only used if the standard input does
|
|
not correspond to a tty device.
|
|
It is called whenever data can be read from the standard input but
|
|
before it is passed to the running command.
|
|
This allows the plugin to reject data if it chooses to
|
|
(for instance if the input contains banned content).
|
|
Returns 1 if the data should be passed to the command, 0 if the data is
|
|
rejected (which will terminate the running command) or \-1 if an error occurred.
|
|
.sp
|
|
The function arguments are as follows:
|
|
.TP 6n
|
|
buf
|
|
The buffer containing user input.
|
|
.TP 6n
|
|
len
|
|
The length of
|
|
\fIbuf\fR
|
|
in bytes.
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.TP 6n
|
|
log_stdout
|
|
.nf
|
|
.RS 6n
|
|
int (*log_stdout)(const char *buf, unsigned int len);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBlog_stdout\fR()
|
|
function is only used if the standard output does not correspond
|
|
to a tty device.
|
|
It is called whenever data can be read from the command but before
|
|
it is written to the standard output.
|
|
This allows the plugin to reject data if it chooses to
|
|
(for instance if the output contains banned content).
|
|
Returns 1 if the data should be passed to the user, 0 if the data is
|
|
rejected (which will terminate the running command) or \-1 if an error occurred.
|
|
.sp
|
|
The function arguments are as follows:
|
|
.TP 6n
|
|
buf
|
|
The buffer containing command output.
|
|
.TP 6n
|
|
len
|
|
The length of
|
|
\fIbuf\fR
|
|
in bytes.
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.TP 6n
|
|
log_stderr
|
|
.nf
|
|
.RS 6n
|
|
int (*log_stderr)(const char *buf, unsigned int len);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBlog_stderr\fR()
|
|
function is only used if the standard error does
|
|
not correspond to a tty device.
|
|
It is called whenever data can be read from the command but before it
|
|
is written to the standard error.
|
|
This allows the plugin to reject data if it chooses to
|
|
(for instance if the output contains banned content).
|
|
Returns 1 if the data should be passed to the user, 0 if the data is
|
|
rejected (which will terminate the running command) or \-1 if an error occurred.
|
|
.sp
|
|
The function arguments are as follows:
|
|
.TP 6n
|
|
buf
|
|
The buffer containing command output.
|
|
.TP 6n
|
|
len
|
|
The length of
|
|
\fIbuf\fR
|
|
in bytes.
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.TP 6n
|
|
register_hooks
|
|
See the
|
|
\fIPolicy plugin API\fR
|
|
section for a description of
|
|
\fRregister_hooks\fR.
|
|
.TP 6n
|
|
deregister_hooks
|
|
See the
|
|
\fIPolicy plugin API\fR
|
|
section for a description of
|
|
\fRderegister_hooks.\fR
|
|
.PP
|
|
\fII/O Plugin Version Macros\fR
|
|
.PP
|
|
Same as for the
|
|
\fIPolicy plugin API\fR.
|
|
.SS "Signal handlers"
|
|
The
|
|
\fBsudo\fR
|
|
front end installs default signal handlers to trap common signals
|
|
while the plugin functions are run.
|
|
The following signals are trapped by default before the command is
|
|
executed:
|
|
.TP 4n
|
|
\fB\(bu\fR
|
|
\fRSIGALRM\fR
|
|
.PD 0
|
|
.TP 4n
|
|
\fB\(bu\fR
|
|
\fRSIGHUP\fR
|
|
.TP 4n
|
|
\fB\(bu\fR
|
|
\fRSIGINT\fR
|
|
.TP 4n
|
|
\fB\(bu\fR
|
|
\fRSIGPIPE\fR
|
|
.TP 4n
|
|
\fB\(bu\fR
|
|
\fRSIGQUIT\fR
|
|
.TP 4n
|
|
\fB\(bu\fR
|
|
\fRSIGTERM\fR
|
|
.TP 4n
|
|
\fB\(bu\fR
|
|
\fRSIGTSTP\fR
|
|
.TP 4n
|
|
\fB\(bu\fR
|
|
\fRSIGUSR1\fR
|
|
.TP 4n
|
|
\fB\(bu\fR
|
|
\fRSIGUSR2\fR
|
|
.PD
|
|
.PP
|
|
If a fatal signal is received before the command is executed,
|
|
\fBsudo\fR
|
|
will call the plugin's
|
|
\fBclose\fR()
|
|
function with an exit status of 128 plus the value of the signal
|
|
that was received.
|
|
This allows for consistent logging of commands killed by a signal
|
|
for plugins that log such information in their
|
|
\fBclose\fR()
|
|
function.
|
|
An exception to this is
|
|
\fRSIGPIPE\fR,
|
|
which is ignored until the command is executed.
|
|
.PP
|
|
A plugin may temporarily install its own signal handlers but must
|
|
restore the original handler before the plugin function returns.
|
|
.SS "Hook function API"
|
|
Beginning with plugin API version 1.2, it is possible to install
|
|
hooks for certain functions called by the
|
|
\fBsudo\fR
|
|
front end.
|
|
.PP
|
|
Currently, the only supported hooks relate to the handling of
|
|
environment variables.
|
|
Hooks can be used to intercept attempts to get, set, or remove
|
|
environment variables so that these changes can be reflected in
|
|
the version of the environment that is used to execute a command.
|
|
A future version of the API will support hooking internal
|
|
\fBsudo\fR
|
|
front end functions as well.
|
|
.PP
|
|
\fIHook structure\fR
|
|
.PP
|
|
Hooks in
|
|
\fBsudo\fR
|
|
are described by the following structure:
|
|
.nf
|
|
.sp
|
|
.RS 0n
|
|
typedef int (*sudo_hook_fn_t)();
|
|
|
|
struct sudo_hook {
|
|
unsigned int hook_version;
|
|
unsigned int hook_type;
|
|
sudo_hook_fn_t hook_fn;
|
|
void *closure;
|
|
};
|
|
.RE
|
|
.fi
|
|
.PP
|
|
The
|
|
\fRsudo_hook\fR
|
|
structure has the following fields:
|
|
.TP 6n
|
|
hook_version
|
|
The
|
|
\fRhook_version\fR
|
|
field should be set to
|
|
\fRSUDO_HOOK_VERSION\fR.
|
|
.TP 6n
|
|
hook_type
|
|
The
|
|
\fRhook_type\fR
|
|
field may be one of the following supported hook types:
|
|
.PP
|
|
.RS 6n
|
|
.PD 0
|
|
.TP 6n
|
|
\fRSUDO_HOOK_SETENV\fR
|
|
The C library
|
|
setenv(3)
|
|
function.
|
|
Any registered hooks will run before the C library implementation.
|
|
The
|
|
\fRhook_fn\fR
|
|
field should
|
|
be a function that matches the following typedef:
|
|
.nf
|
|
.sp
|
|
.RS 6n
|
|
typedef int (*sudo_hook_fn_setenv_t)(const char *name,
|
|
const char *value, int overwrite, void *closure);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
If the registered hook does not match the typedef the results are
|
|
unspecified.
|
|
.RE
|
|
.PD
|
|
.TP 6n
|
|
\fRSUDO_HOOK_UNSETENV\fR
|
|
The C library
|
|
unsetenv(3)
|
|
function.
|
|
Any registered hooks will run before the C library implementation.
|
|
The
|
|
\fRhook_fn\fR
|
|
field should
|
|
be a function that matches the following typedef:
|
|
.nf
|
|
.sp
|
|
.RS 6n
|
|
typedef int (*sudo_hook_fn_unsetenv_t)(const char *name,
|
|
void *closure);
|
|
.RE
|
|
.fi
|
|
.TP 6n
|
|
\fRSUDO_HOOK_GETENV\fR
|
|
The C library
|
|
getenv(3)
|
|
function.
|
|
Any registered hooks will run before the C library implementation.
|
|
The
|
|
\fRhook_fn\fR
|
|
field should
|
|
be a function that matches the following typedef:
|
|
.nf
|
|
.sp
|
|
.RS 6n
|
|
typedef int (*sudo_hook_fn_getenv_t)(const char *name,
|
|
char **value, void *closure);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
If the registered hook does not match the typedef the results are
|
|
unspecified.
|
|
.RE
|
|
.TP 6n
|
|
\fRSUDO_HOOK_PUTENV\fR
|
|
The C library
|
|
putenv(3)
|
|
function.
|
|
Any registered hooks will run before the C library implementation.
|
|
The
|
|
\fRhook_fn\fR
|
|
field should
|
|
be a function that matches the following typedef:
|
|
.nf
|
|
.sp
|
|
.RS 6n
|
|
typedef int (*sudo_hook_fn_putenv_t)(char *string,
|
|
void *closure);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
If the registered hook does not match the typedef the results are
|
|
unspecified.
|
|
.RE
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.TP 6n
|
|
hook_fn
|
|
sudo_hook_fn_t hook_fn;
|
|
.sp
|
|
The
|
|
\fRhook_fn\fR
|
|
field should be set to the plugin's hook implementation.
|
|
The actual function arguments will vary depending on the
|
|
\fRhook_type\fR
|
|
(see
|
|
\fRhook_type\fR
|
|
above).
|
|
In all cases, the
|
|
\fRclosure\fR
|
|
field of
|
|
\fRstruct sudo_hook\fR
|
|
is passed as the last function parameter.
|
|
This can be used to pass arbitrary data to the plugin's hook implementation.
|
|
.sp
|
|
The function return value may be one of the following:
|
|
.PP
|
|
.RS 6n
|
|
.PD 0
|
|
.TP 6n
|
|
\fRSUDO_HOOK_RET_ERROR\fR
|
|
The hook function encountered an error.
|
|
.PD
|
|
.TP 6n
|
|
\fRSUDO_HOOK_RET_NEXT\fR
|
|
The hook completed without error, go on to the next hook (including
|
|
the native implementation if applicable).
|
|
For example, a
|
|
getenv(3)
|
|
hook might return
|
|
\fRSUDO_HOOK_RET_NEXT\fR
|
|
if the specified variable was not found in the private copy of the environment.
|
|
.TP 6n
|
|
\fRSUDO_HOOK_RET_STOP\fR
|
|
The hook completed without error, stop processing hooks for this invocation.
|
|
This can be used to replace the native implementation.
|
|
For example, a
|
|
\fRsetenv\fR
|
|
hook that operates on a private copy of
|
|
the environment but leaves
|
|
\fRenviron\fR
|
|
unchanged.
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.PP
|
|
Note that it is very easy to create an infinite loop when hooking
|
|
C library functions.
|
|
For example, a
|
|
getenv(3)
|
|
hook that calls the
|
|
snprintf(3)
|
|
function may create a loop if the
|
|
snprintf(3)
|
|
implementation calls
|
|
getenv(3)
|
|
to check the locale.
|
|
To prevent this, you may wish to use a static variable in the hook
|
|
function to guard against nested calls.
|
|
For example:
|
|
.nf
|
|
.sp
|
|
.RS 0n
|
|
static int in_progress = 0; /* avoid recursion */
|
|
if (in_progress)
|
|
return SUDO_HOOK_RET_NEXT;
|
|
in_progress = 1;
|
|
\&...
|
|
in_progress = 0;
|
|
return SUDO_HOOK_RET_STOP;
|
|
.RE
|
|
.fi
|
|
.PP
|
|
\fIHook API Version Macros\fR
|
|
.nf
|
|
.sp
|
|
.RS 0n
|
|
/* Hook API version major/minor */
|
|
#define SUDO_HOOK_VERSION_MAJOR 1
|
|
#define SUDO_HOOK_VERSION_MINOR 0
|
|
#define SUDO_HOOK_VERSION SUDO_API_MKVERSION(SUDO_HOOK_VERSION_MAJOR,\e
|
|
SUDO_HOOK_VERSION_MINOR)
|
|
.RE
|
|
.fi
|
|
.PP
|
|
For getters and setters see the
|
|
\fIPolicy plugin API\fR.
|
|
.SS "Remote command execution"
|
|
The
|
|
\fBsudo\fR
|
|
front end does not have native support for running remote commands.
|
|
However, starting with
|
|
\fBsudo\fR
|
|
1.8.8, the
|
|
\fB\-h\fR
|
|
option may be used to specify a remote host that is passed
|
|
to the policy plugin.
|
|
A plugin may also accept a
|
|
\fIrunas_user\fR
|
|
in the form of
|
|
\(Lquser@hostname\(Rq
|
|
which will work with older versions of
|
|
\fBsudo\fR.
|
|
It is anticipated that remote commands will be supported by executing a
|
|
\(Lqhelper\(Rq
|
|
program.
|
|
The policy plugin should setup the execution environment such that the
|
|
\fBsudo\fR
|
|
front end will run the helper which, in turn, will connect to the
|
|
remote host and run the command.
|
|
.PP
|
|
For example, the policy plugin could utilize
|
|
\fBssh\fR
|
|
to perform remote command execution.
|
|
The helper program would be responsible for running
|
|
\fBssh\fR
|
|
with the proper options to use a private key or certificate
|
|
that the remote host will accept and run a program
|
|
on the remote host that would setup the execution environment
|
|
accordingly.
|
|
.PP
|
|
Note that remote
|
|
\fBsudoedit\fR
|
|
functionality must be handled by the policy plugin, not
|
|
\fBsudo\fR
|
|
itself as the front end has no knowledge that a remote command is
|
|
being executed.
|
|
This may be addressed in a future revision of the plugin API.
|
|
.SS "Conversation API"
|
|
If the plugin needs to interact with the user, it may do so via the
|
|
\fBconversation\fR()
|
|
function.
|
|
A plugin should not attempt to read directly from the standard input
|
|
or the user's tty (neither of which are guaranteed to exist).
|
|
The caller must include a trailing newline in
|
|
\fRmsg\fR
|
|
if one is to be printed.
|
|
.PP
|
|
A
|
|
\fBprintf\fR()-style
|
|
function is also available that can be used to display informational
|
|
or error messages to the user, which is usually more convenient for
|
|
simple messages where no use input is required.
|
|
.PP
|
|
\fIConversation function structures\fR
|
|
.PP
|
|
The conversation function takes as arguments pointers to the following
|
|
structures:
|
|
.nf
|
|
.sp
|
|
.RS 0n
|
|
struct sudo_conv_message {
|
|
#define SUDO_CONV_PROMPT_ECHO_OFF 0x0001 /* do not echo user input */
|
|
#define SUDO_CONV_PROMPT_ECHO_ON 0x0002 /* echo user input */
|
|
#define SUDO_CONV_ERROR_MSG 0x0003 /* error message */
|
|
#define SUDO_CONV_INFO_MSG 0x0004 /* informational message */
|
|
#define SUDO_CONV_PROMPT_MASK 0x0005 /* mask user input */
|
|
#define SUDO_CONV_PROMPT_ECHO_OK 0x1000 /* flag: allow echo if no tty */
|
|
int msg_type;
|
|
int timeout;
|
|
const char *msg;
|
|
};
|
|
|
|
#define SUDO_CONV_REPL_MAX 255
|
|
|
|
struct sudo_conv_reply {
|
|
char *reply;
|
|
};
|
|
|
|
typedef int (*sudo_conv_callback_fn_t)(int signo, void *closure);
|
|
struct sudo_conv_callback {
|
|
unsigned int version;
|
|
void *closure;
|
|
sudo_conv_callback_fn_t on_suspend;
|
|
sudo_conv_callback_fn_t on_resume;
|
|
};
|
|
.RE
|
|
.fi
|
|
.PP
|
|
Pointers to the
|
|
\fBconversation\fR()
|
|
and
|
|
\fBprintf\fR()-style
|
|
functions are passed
|
|
in to the plugin's
|
|
\fBopen\fR()
|
|
function when the plugin is initialized.
|
|
The following type definitions can be used in the declaration of the
|
|
\fBopen\fR()
|
|
function:
|
|
.nf
|
|
.sp
|
|
.RS 0n
|
|
typedef int (*sudo_conv_t)(int num_msgs,
|
|
const struct sudo_conv_message msgs[],
|
|
struct sudo_conv_reply replies[],
|
|
struct sudo_conv_callback *callback);
|
|
|
|
typedef int (*sudo_printf_t)(int msg_type, const char *fmt, ...);
|
|
.RE
|
|
.fi
|
|
.PP
|
|
To use the
|
|
\fBconversation\fR()
|
|
function, the plugin must pass an array of
|
|
\fRsudo_conv_message\fR
|
|
and
|
|
\fRsudo_conv_reply\fR
|
|
structures.
|
|
There must be a
|
|
\fRstruct sudo_conv_message\fR
|
|
and
|
|
\fRstruct sudo_conv_reply\fR
|
|
for
|
|
each message in the conversation.
|
|
The
|
|
\fRstruct sudo_conv_callback\fR
|
|
pointer, if not
|
|
\fRNULL\fR,
|
|
should contain function pointers to be called when the
|
|
\fBsudo\fR
|
|
process is suspended and/or resumed during conversation input.
|
|
The
|
|
\fIon_suspend\fR
|
|
and
|
|
\fIon_resume\fR
|
|
functions are called with the signal that caused
|
|
\fBsudo\fR
|
|
to be suspended and the
|
|
\fIclosure\fR
|
|
pointer from the
|
|
\fRstruct sudo_conv_callback\fR.
|
|
These functions should return 0 on success and \-1 on error.
|
|
On error, the conversation will end and the conversation function
|
|
will return a value of \-1.
|
|
The intended use is to allow the plugin to release resources, such as locks,
|
|
that should not be held indefinitely while suspended and then reacquire them
|
|
when the process is resumed.
|
|
Note that the functions are not actually invoked from within a signal handler.
|
|
.PP
|
|
The plugin is responsible for freeing the reply buffer located in each
|
|
\fRstruct sudo_conv_reply\fR,
|
|
if it is not
|
|
\fRNULL\fR.
|
|
\fRSUDO_CONV_REPL_MAX\fR
|
|
represents the maximum length of the reply buffer (not including
|
|
the trailing NUL character).
|
|
In practical terms, this is the longest password
|
|
\fBsudo\fR
|
|
will support.
|
|
It is also useful as a maximum value for the
|
|
\fBmemset_s\fR()
|
|
function when clearing passwords filled in by the conversation function.
|
|
.PP
|
|
The
|
|
\fBprintf\fR()-style
|
|
function uses the same underlying mechanism as the
|
|
\fBconversation\fR()
|
|
function but only supports
|
|
\fRSUDO_CONV_INFO_MSG\fR
|
|
and
|
|
\fRSUDO_CONV_ERROR_MSG\fR
|
|
for the
|
|
\fImsg_type\fR
|
|
parameter.
|
|
It can be more convenient than using the
|
|
\fBconversation\fR()
|
|
function if no user reply is needed and supports standard
|
|
\fBprintf\fR()
|
|
escape sequences.
|
|
.PP
|
|
See the sample plugin for an example of the
|
|
\fBconversation\fR()
|
|
function usage.
|
|
.SS "Sudoers group plugin API"
|
|
The
|
|
\fBsudoers\fR
|
|
plugin supports its own plugin interface to allow non-Unix
|
|
group lookups.
|
|
This can be used to query a group source other than the standard Unix
|
|
group database.
|
|
Two sample group plugins are bundled with
|
|
\fBsudo\fR,
|
|
\fIgroup_file\fR
|
|
and
|
|
\fIsystem_group\fR,
|
|
are detailed in
|
|
sudoers(@mansectform@).
|
|
Third party group plugins include a QAS AD plugin available from Quest Software.
|
|
.PP
|
|
A group plugin must declare and populate a
|
|
\fRsudoers_group_plugin\fR
|
|
struct in the global scope.
|
|
This structure contains pointers to the functions that implement plugin
|
|
initialization, cleanup and group lookup.
|
|
.nf
|
|
.sp
|
|
.RS 0n
|
|
struct sudoers_group_plugin {
|
|
unsigned int version;
|
|
int (*init)(int version, sudo_printf_t sudo_printf,
|
|
char *const argv[]);
|
|
void (*cleanup)(void);
|
|
int (*query)(const char *user, const char *group,
|
|
const struct passwd *pwd);
|
|
};
|
|
.RE
|
|
.fi
|
|
.PP
|
|
The
|
|
\fRsudoers_group_plugin\fR
|
|
struct has the following fields:
|
|
.TP 6n
|
|
version
|
|
The
|
|
\fRversion\fR
|
|
field should be set to GROUP_API_VERSION.
|
|
.sp
|
|
This allows
|
|
\fBsudoers\fR
|
|
to determine the API version the group plugin
|
|
was built against.
|
|
.TP 6n
|
|
init
|
|
.nf
|
|
.RS 6n
|
|
int (*init)(int version, sudo_printf_t plugin_printf,
|
|
char *const argv[]);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBinit\fR()
|
|
function is called after
|
|
\fIsudoers\fR
|
|
has been parsed but
|
|
before any policy checks.
|
|
It returns 1 on success, 0 on failure (or if the plugin is not configured),
|
|
and \-1 if a error occurred.
|
|
If an error occurs, the plugin may call the
|
|
\fBplugin_printf\fR()
|
|
function with
|
|
\fRSUDO_CONF_ERROR_MSG\fR
|
|
to present additional error information
|
|
to the user.
|
|
.sp
|
|
The function arguments are as follows:
|
|
.TP 6n
|
|
version
|
|
The version passed in by
|
|
\fBsudoers\fR
|
|
allows the plugin to determine the
|
|
major and minor version number of the group plugin API supported by
|
|
\fBsudoers\fR.
|
|
.TP 6n
|
|
plugin_printf
|
|
A pointer to a
|
|
\fBprintf\fR()-style
|
|
function that may be used to display informational or error message to the user.
|
|
Returns the number of characters printed on success and \-1 on failure.
|
|
.TP 6n
|
|
argv
|
|
A
|
|
\fRNULL\fR-terminated
|
|
array of arguments generated from the
|
|
\fIgroup_plugin\fR
|
|
option in
|
|
\fIsudoers\fR.
|
|
If no arguments were given,
|
|
\fIargv\fR
|
|
will be
|
|
\fRNULL\fR.
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.TP 6n
|
|
cleanup
|
|
.nf
|
|
.RS 6n
|
|
void (*cleanup)();
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBcleanup\fR()
|
|
function is called when
|
|
\fBsudoers\fR
|
|
has finished its
|
|
group checks.
|
|
The plugin should free any memory it has allocated and close open file handles.
|
|
.RE
|
|
.TP 6n
|
|
query
|
|
.br
|
|
.nf
|
|
.RS 6n
|
|
int (*query)(const char *user, const char *group,
|
|
const struct passwd *pwd);
|
|
.RE
|
|
.fi
|
|
.RS 6n
|
|
.sp
|
|
The
|
|
\fBquery\fR()
|
|
function is used to ask the group plugin whether
|
|
\fIuser\fR
|
|
is a member of
|
|
\fIgroup\fR.
|
|
.sp
|
|
The function arguments are as follows:
|
|
.TP 6n
|
|
user
|
|
The name of the user being looked up in the external group database.
|
|
.TP 6n
|
|
group
|
|
.br
|
|
The name of the group being queried.
|
|
.TP 6n
|
|
pwd
|
|
The password database entry for
|
|
\fIuser\fR,
|
|
if any.
|
|
If
|
|
\fIuser\fR
|
|
is not
|
|
present in the password database,
|
|
\fIpwd\fR
|
|
will be
|
|
\fRNULL\fR.
|
|
.PD 0
|
|
.PP
|
|
.RE
|
|
.PD
|
|
.PP
|
|
\fIGroup API Version Macros\fR
|
|
.nf
|
|
.sp
|
|
.RS 0n
|
|
/* Sudoers group plugin version major/minor */
|
|
#define GROUP_API_VERSION_MAJOR 1
|
|
#define GROUP_API_VERSION_MINOR 0
|
|
#define GROUP_API_VERSION ((GROUP_API_VERSION_MAJOR << 16) | \e
|
|
GROUP_API_VERSION_MINOR)
|
|
.RE
|
|
.fi
|
|
For getters and setters see the
|
|
\fIPolicy plugin API\fR.
|
|
.SH "PLUGIN API CHANGELOG"
|
|
The following revisions have been made to the Sudo Plugin API.
|
|
.TP 6n
|
|
Version 1.0
|
|
Initial API version.
|
|
.TP 6n
|
|
Version 1.1 (sudo 1.8.0)
|
|
The I/O logging plugin's
|
|
\fBopen\fR()
|
|
function was modified to take the
|
|
\fRcommand_info\fR
|
|
list as an argument.
|
|
.TP 6n
|
|
Version 1.2 (sudo 1.8.5)
|
|
The Policy and I/O logging plugins'
|
|
\fBopen\fR()
|
|
functions are now passed
|
|
a list of plugin parameters if any are specified in
|
|
sudo.conf(@mansectform@).
|
|
.sp
|
|
A simple hooks API has been introduced to allow plugins to hook in to the
|
|
system's environment handling functions.
|
|
.sp
|
|
The
|
|
\fRinit_session\fR
|
|
Policy plugin function is now passed a pointer
|
|
to the user environment which can be updated as needed.
|
|
This can be used to merge in environment variables stored in the PAM
|
|
handle before a command is run.
|
|
.TP 6n
|
|
Version 1.3 (sudo 1.8.7)
|
|
Support for the
|
|
\fIexec_background\fR
|
|
entry has been added to the
|
|
\fRcommand_info\fR
|
|
list.
|
|
.sp
|
|
The
|
|
\fImax_groups\fR
|
|
and
|
|
\fIplugin_dir\fR
|
|
entries were added to the
|
|
\fRsettings\fR
|
|
list.
|
|
.sp
|
|
The
|
|
\fBversion\fR()
|
|
and
|
|
\fBclose\fR()
|
|
functions are now optional.
|
|
Previously, a missing
|
|
\fBversion\fR()
|
|
or
|
|
\fBclose\fR()
|
|
function would result in a crash.
|
|
If no policy plugin
|
|
\fBclose\fR()
|
|
function is defined, a default
|
|
\fBclose\fR()
|
|
function will be provided by the
|
|
\fBsudo\fR
|
|
front end that displays a warning if the command could not be
|
|
executed.
|
|
.sp
|
|
The
|
|
\fBsudo\fR
|
|
front end now installs default signal handlers to trap common signals
|
|
while the plugin functions are run.
|
|
.TP 6n
|
|
Version 1.4 (sudo 1.8.8)
|
|
The
|
|
\fIremote_host\fR
|
|
entry was added to the
|
|
\fRsettings\fR
|
|
list.
|
|
.TP 6n
|
|
Version 1.5 (sudo 1.8.9)
|
|
The
|
|
\fIpreserve_fds\fR
|
|
entry was added to the
|
|
\fRcommand_info\fR
|
|
list.
|
|
.TP 6n
|
|
Version 1.6 (sudo 1.8.11)
|
|
The behavior when an I/O logging plugin returns an error
|
|
(\-1)
|
|
has changed.
|
|
Previously, the
|
|
\fBsudo\fR
|
|
front end took no action when the
|
|
\fBlog_ttyin\fR(),
|
|
\fBlog_ttyout\fR(),
|
|
\fBlog_stdin\fR(),
|
|
\fBlog_stdout\fR(),
|
|
or
|
|
\fBlog_stderr\fR()
|
|
function returned an error.
|
|
.sp
|
|
The behavior when an I/O logging plugin returns 0 has changed.
|
|
Previously, output from the command would be displayed to the
|
|
terminal even if an output logging function returned 0.
|
|
.TP 6n
|
|
Version 1.7 (sudo 1.8.12)
|
|
The
|
|
\fIplugin_path\fR
|
|
entry was added to the
|
|
\fRsettings\fR
|
|
list.
|
|
.sp
|
|
The
|
|
\fIdebug_flags\fR
|
|
entry now starts with a debug file path name and may occur multiple
|
|
times if there are multiple plugin-specific Debug lines in the
|
|
sudo.conf(@mansectform@) file.
|
|
.TP 6n
|
|
Version 1.8 (sudo 1.8.15)
|
|
The
|
|
\fIsudoedit_checkdir\fR
|
|
and
|
|
\fIsudoedit_follow\fR
|
|
entries were added to the
|
|
\fRcommand_info\fR
|
|
list.
|
|
The default value of
|
|
\fIsudoedit_checkdir\fR
|
|
was changed to true in sudo 1.8.16.
|
|
.sp
|
|
The sudo
|
|
\fIconversation\fR
|
|
function now takes a pointer to a
|
|
\fRstruct sudo_conv_callback\fR
|
|
as its fourth argument.
|
|
The
|
|
\fRsudo_conv_t\fR
|
|
definition has been updated to match.
|
|
The plugin must specify that it supports plugin API version 1.8 or higher
|
|
to receive a conversation function pointer that supports this argument.
|
|
.TP 6n
|
|
Version 1.9 (sudo 1.8.16)
|
|
The
|
|
\fIexecfd\fR
|
|
entry was added to the
|
|
\fRcommand_info\fR
|
|
list.
|
|
.TP 6n
|
|
Version 1.10 (sudo 1.8.19)
|
|
The
|
|
\fIumask\fR
|
|
entry was added to the
|
|
\fRuser_info\fR
|
|
list.
|
|
The
|
|
\fIiolog_group\fR,
|
|
\fIiolog_mode\fR,
|
|
and
|
|
\fIiolog_user\fR
|
|
entries were added to the
|
|
\fRcommand_info\fR
|
|
list.
|
|
.TP 6n
|
|
Version 1.11 (sudo 1.8.20)
|
|
The
|
|
\fItimeout\fR
|
|
entry was added to the
|
|
\fRsettings\fR
|
|
list.
|
|
.SH "SEE ALSO"
|
|
sudo.conf(@mansectform@),
|
|
sudoers(@mansectform@),
|
|
sudo(@mansectsu@)
|
|
.SH "AUTHORS"
|
|
Many people have worked on
|
|
\fBsudo\fR
|
|
over the years; this version consists of code written primarily by:
|
|
.sp
|
|
.RS 6n
|
|
Todd C. Miller
|
|
.RE
|
|
.PP
|
|
See the CONTRIBUTORS file in the
|
|
\fBsudo\fR
|
|
distribution (https://www.sudo.ws/contributors.html) for an
|
|
exhaustive list of people who have contributed to
|
|
\fBsudo\fR.
|
|
.SH "BUGS"
|
|
If you feel you have found a bug in
|
|
\fBsudo\fR,
|
|
please submit a bug report at https://bugzilla.sudo.ws/
|
|
.SH "SUPPORT"
|
|
Limited free support is available via the sudo-users mailing list,
|
|
see https://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or
|
|
search the archives.
|
|
.SH "DISCLAIMER"
|
|
\fBsudo\fR
|
|
is provided
|
|
\(LqAS IS\(Rq
|
|
and any express or implied warranties, including, but not limited
|
|
to, the implied warranties of merchantability and fitness for a
|
|
particular purpose are disclaimed.
|
|
See the LICENSE file distributed with
|
|
\fBsudo\fR
|
|
or https://www.sudo.ws/license.html for complete details.
|