SUDO_PLUGIN(4) File Formats Manual SUDO_PLUGIN(4)
NNAAMMEE
ssuuddoo__pplluuggiinn - Sudo Plugin API
DDEESSCCRRIIPPTTIIOONN
Starting with version 1.8, ssuuddoo supports a plugin API for policy and
session logging. Plugins may be compiled as dynamic shared objects (the
default on systems that support them) or compiled statically into the
ssuuddoo binary itself. By default, the ssuuddooeerrss policy plugin and an
associated I/O logging plugin are used. Via the plugin API, ssuuddoo can be
configured to use alternate policy and/or I/O logging plugins provided by
third parties. The plugins to be used are specified in the sudo.conf(4)
file.
The API is versioned with a major and minor number. The minor version
number is incremented when additions are made. The major number is
incremented when incompatible changes are made. A plugin should be check
the version passed to it and make sure that the major version matches.
The plugin API is defined by the sudo_plugin.h header file.
PPoolliiccyy pplluuggiinn AAPPII
A policy plugin must declare and populate a policy_plugin struct in the
global scope. This structure contains pointers to the functions that
implement the ssuuddoo policy checks. The name of the symbol should be
specified in sudo.conf(4) along with a path to the plugin so that ssuuddoo
can load it.
struct policy_plugin {
#define SUDO_POLICY_PLUGIN 1
unsigned int type; /* always SUDO_POLICY_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 user_env[],
char * const plugin_options[]);
void (*close)(int exit_status, int error);
int (*show_version)(int verbose);
int (*check_policy)(int argc, char * const argv[],
char *env_add[], char **command_info[],
char **argv_out[], char **user_env_out[]);
int (*list)(int argc, char * const argv[], int verbose,
const char *list_user);
int (*validate)(void);
void (*invalidate)(int remove);
int (*init_session)(struct passwd *pwd, char **user_env[]);
void (*register_hooks)(int version,
int (*register_hook)(struct sudo_hook *hook));
void (*deregister_hooks)(int version,
int (*deregister_hook)(struct sudo_hook *hook));
};
The policy_plugin struct has the following fields:
type The type field should always be set to SUDO_POLICY_PLUGIN.
version
The version field should be set to SUDO_API_VERSION.
This allows ssuuddoo to determine the API version the plugin was built
against.
open
int (*open)(unsigned int version, sudo_conv_t conversation,
sudo_printf_t plugin_printf, char * const settings[],
char * const user_info[], char * const user_env[],
char * const plugin_options[]);
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, ssuuddoo will
print a usage message before it exits. If an error occurs, the
plugin may optionally call the ccoonnvveerrssaattiioonn() or pplluuggiinn__pprriinnttff()
function with SUDO_CONF_ERROR_MSG to present additional error
information to the user.
The function arguments are as follows:
version
The version passed in by ssuuddoo allows the plugin to determine
the major and minor version number of the plugin API
supported by ssuuddoo.
conversation
A pointer to the ccoonnvveerrssaattiioonn() function that can be used by
the plugin to interact with the user (see below). Returns 0
on success and -1 on failure.
plugin_printf
A pointer to a pprriinnttff()-style function that may be used to
display informational or error messages (see below). Returns
the number of characters printed on success and -1 on
failure.
settings
A vector of user-supplied ssuuddoo settings in the form of
``name=value'' strings. The vector is terminated by a NULL
pointer. These settings correspond to flags the user
specified when running ssuuddoo. As such, they will only be
present when the corresponding flag has been specified on the
command line.
When parsing _s_e_t_t_i_n_g_s, the plugin should split on the ffiirrsstt
equal sign (`=') since the _n_a_m_e field will never include one
itself but the _v_a_l_u_e might.
bsdauth_type=string
Authentication type, if specified by the --aa flag, to
use on systems where BSD authentication is supported.
closefrom=number
If specified, the user has requested via the --CC flag
that ssuuddoo close all files descriptors with a value of
_n_u_m_b_e_r or higher. The plugin may optionally pass this,
or another value, back in the _c_o_m_m_a_n_d___i_n_f_o list.
debug_flags=string
A debug file path name followed by a space and a comma-
separated list of debug flags that correspond to the
plugin's Debug entry in sudo.conf(4), if there is one.
The flags are passed to the plugin exactly as they
appear in sudo.conf(4). The syntax used by ssuuddoo and
the ssuuddooeerrss plugin is _s_u_b_s_y_s_t_e_m@_p_r_i_o_r_i_t_y but a plugin
is free to use a different format so long as it does
not include a comma (`,'). Prior to ssuuddoo 1.8.12, there
was no way to specify plugin-specific _d_e_b_u_g___f_l_a_g_s so
the value was always the same as that used by the ssuuddoo
front end and did not include a path name, only the
flags themselves. As of version 1.7 of the plugin
interface, ssuuddoo will only pass _d_e_b_u_g___f_l_a_g_s if
sudo.conf(4) contains a plugin-specific Debug entry.
debug_level=number
This setting has been deprecated in favor of
_d_e_b_u_g___f_l_a_g_s.
ignore_ticket=bool
Set to true if the user specified the --kk flag along
with a command, indicating that the user wishes to
ignore any cached authentication credentials.
_i_m_p_l_i_e_d___s_h_e_l_l to true. This allows ssuuddoo 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 cchheecckk__ppoolliiccyy() function, which will
cause ssuuddoo to print a usage message and exit.
implied_shell=bool
If the user does not specify a program on the command
line, ssuuddoo will pass the plugin the path to the user's
shell and set
login_class=string
BSD login class to use when setting resource limits and
nice value, if specified by the --cc flag.
login_shell=bool
Set to true if the user specified the --ii flag,
indicating that the user wishes to run a login shell.
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(4).
network_addrs=list
A space-separated list of IP network addresses and
netmasks in the form ``addr/netmask'', e.g.
``192.168.1.2/255.255.255.0''. The address and netmask
pairs may be either IPv4 or IPv6, depending on what the
operating system supports. If the address contains a
colon (`:'), it is an IPv6 address, else it is IPv4.
noninteractive=bool
Set to true if the user specified the --nn flag,
indicating that ssuuddoo should operate in non-interactive
mode. The plugin may reject a command run in non-
interactive mode if user interaction is required.
plugin_dir=string
The default plugin directory used by the ssuuddoo 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.
plugin_path=string
The path name of plugin loaded by the ssuuddoo front end.
The path name will be a fully-qualified unless the
plugin was statically compiled into ssuuddoo.
preserve_environment=bool
Set to true if the user specified the --EE flag,
indicating that the user wishes to preserve the
environment.
preserve_groups=bool
Set to true if the user specified the --PP flag,
indicating that the user wishes to preserve the group
vector instead of setting it based on the runas user.
progname=string
The command name that sudo was run as, typically
``sudo'' or ``sudoedit''.
prompt=string
The prompt to use when requesting a password, if
specified via the --pp flag.
remote_host=string
The name of the remote host to run the command on, if
specified via the --hh 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 ssuuddoo front end is only capable
of executing commands on the local host. Only
available starting with API version 1.4.
run_shell=bool
Set to true if the user specified the --ss flag,
indicating that the user wishes to run a shell.
runas_group=string
The group name or gid to run the command as, if
specified via the --gg flag.
runas_user=string
The user name or uid to run the command as, if
specified via the --uu flag.
selinux_role=string
SELinux role to use when executing the command, if
specified by the --rr flag.
selinux_type=string
SELinux type to use when executing the command, if
specified by the --tt flag.
set_home=bool
Set to true if the user specified the --HH flag. If
true, set the HOME environment variable to the target
user's home directory.
sudoedit=bool
Set to true when the --ee flag is is specified or if
invoked as ssuuddooeeddiitt. The plugin shall substitute an
editor into _a_r_g_v in the cchheecckk__ppoolliiccyy() function or
return -2 with a usage error if the plugin does not
support _s_u_d_o_e_d_i_t. For more information, see the
_c_h_e_c_k___p_o_l_i_c_y section.
Additional settings may be added in the future so the plugin
should silently ignore settings that it does not recognize.
user_info
A vector of information about the user running the command in
the form of ``name=value'' strings. The vector is terminated
by a NULL pointer.
When parsing _u_s_e_r___i_n_f_o, the plugin should split on the ffiirrsstt
equal sign (`=') since the _n_a_m_e field will never include one
itself but the _v_a_l_u_e might.
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.
cwd=string
The user's current working directory.
egid=gid_t
The effective group ID of the user invoking ssuuddoo.
euid=uid_t
The effective user ID of the user invoking ssuuddoo.
gid=gid_t
The real group ID of the user invoking ssuuddoo.
groups=list
The user's supplementary group list formatted as a
string of comma-separated group IDs.
host=string
The local machine's hostname as returned by the
gethostname(2) system call.
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.
pgid=int
The ID of the process group that the running ssuuddoo
process is a member of. Only available starting with
API version 1.2.
pid=int
The process ID of the running ssuuddoo process. Only
available starting with API version 1.2.
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 NULL-terminated
array of strings. If no arguments were specified,
_p_l_u_g_i_n___o_p_t_i_o_n_s will be the NULL pointer.
NOTE: the _p_l_u_g_i_n___o_p_t_i_o_n_s parameter is only available
starting with API version 1.2. A plugin mmuusstt check the
API version specified by the ssuuddoo front end before
using _p_l_u_g_i_n___o_p_t_i_o_n_s. Failure to do so may result in a
crash.
ppid=int
The parent process ID of the running ssuuddoo process.
Only available starting with API version 1.2.
sid=int
The session ID of the running ssuuddoo process or 0 if ssuuddoo
is not part of a POSIX job control session. Only
available starting with API version 1.2.
tcpgid=int
The ID of the foreground process group associated with
the terminal device associated with the ssuuddoo process or
-1 if there is no terminal present. Only available
starting with API version 1.2.
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 ``tty=''.
uid=uid_t
The real user ID of the user invoking ssuuddoo.
user=string
The name of the user invoking ssuuddoo.
user_env
The user's environment in the form of a NULL-terminated
vector of ``name=value'' strings.
When parsing _u_s_e_r___e_n_v, the plugin should split on the ffiirrsstt
equal sign (`=') since the _n_a_m_e field will never include one
itself but the _v_a_l_u_e might.
close
void (*close)(int exit_status, int error);
The cclloossee() function is called when the command being run by ssuuddoo
finishes.
The function arguments are as follows:
exit_status
The command's exit status, as returned by the wait(2) system
call. The value of exit_status is undefined if error is non-
zero.
error
If the command could not be executed, this is set to the
value of errno set by the execve(2) system call. The plugin
is responsible for displaying error information via the
ccoonnvveerrssaattiioonn() or pplluuggiinn__pprriinnttff() function. If the command
was successfully executed, the value of error is 0.
If no cclloossee() function is defined, no I/O logging plugins are
loaded, and neither the _t_i_m_e_o_u_t not _u_s_e___p_t_y options are set in the
command_info list, the ssuuddoo front end may execute the command
directly instead of running it as a child process.
show_version
int (*show_version)(int verbose);
The sshhooww__vveerrssiioonn() function is called by ssuuddoo when the user
specifies the --VV option. The plugin may display its version
information to the user via the ccoonnvveerrssaattiioonn() or pplluuggiinn__pprriinnttff()
function using SUDO_CONV_INFO_MSG. If the user requests detailed
version information, the verbose flag will be set.
check_policy
int (*check_policy)(int argc, char * const argv[]
char *env_add[], char **command_info[],
char **argv_out[], char **user_env_out[]);
The cchheecckk__ppoolliiccyy() function is called by ssuuddoo to determine whether
the user is allowed to run the specified commands.
If the _s_u_d_o_e_d_i_t option was enabled in the _s_e_t_t_i_n_g_s array passed to
the ooppeenn() function, the user has requested _s_u_d_o_e_d_i_t mode.
_s_u_d_o_e_d_i_t is a mechanism for editing one or more files where an
editor is run with the user's credentials instead of with elevated
privileges. ssuuddoo 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 _s_u_d_o_e_d_i_t, it should choose the editor to be used,
potentially from a variable in the user's environment, such as
EDITOR, and include it in _a_r_g_v___o_u_t (note that environment variables
may include command line flags). The files to be edited should be
copied from _a_r_g_v into _a_r_g_v___o_u_t, separated from the editor and its
arguments by a ``--'' element. The ``--'' will be removed by ssuuddoo
before the editor is executed. The plugin should also set
_s_u_d_o_e_d_i_t_=_t_r_u_e in the _c_o_m_m_a_n_d___i_n_f_o list.
The cchheecckk__ppoolliiccyy() 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 _s_u_d_o_e_d_i_t was specified but is unsupported by the plugin. In the
latter case, ssuuddoo will print a usage message before it exits. If
an error occurs, the plugin may optionally call the ccoonnvveerrssaattiioonn()
or pplluuggiinn__pprriinnttff() function with SUDO_CONF_ERROR_MSG to present
additional error information to the user.
The function arguments are as follows:
argc The number of elements in _a_r_g_v, not counting the final NULL
pointer.
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 NULL
pointer.
env_add
Additional environment variables specified by the user on the
command line in the form of a NULL-terminated vector of
``name=value'' 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.
When parsing _e_n_v___a_d_d, the plugin should split on the ffiirrsstt
equal sign (`=') since the _n_a_m_e field will never include one
itself but the _v_a_l_u_e might.
command_info
Information about the command being run in the form of
``name=value'' strings. These values are used by ssuuddoo 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 NULL pointer. The following values
are recognized by ssuuddoo:
chroot=string
The root directory to use when running the command.
closefrom=number
If specified, ssuuddoo will close all files descriptors
with a value of _n_u_m_b_e_r or higher.
command=string
Fully qualified path to the command to be executed.
cwd=string
The current working directory to change to when
executing the command.
exec_background=bool
By default, ssuuddoo runs a command as the foreground
process as long as ssuuddoo itself is running in the
foreground. When _e_x_e_c___b_a_c_k_g_r_o_u_n_d is enabled and the
command is being run in a pty (due to I/O logging or
the _u_s_e___p_t_y 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
SIGTTIN signal (or SIGTTOU in the case of terminal
settings). If this happens when ssuuddoo 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 ssuuddoo 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 _s_u_d_o behavior
or when the command is not being run in a pty.
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 ttccggeettaattttrr() and
ttccsseettaattttrr() system calls (this is a bug in Mac OS X).
Furthermore, because this behavior depends on the
command stopping with the SIGTTIN or SIGTTOU signals,
programs that catch these signals and suspend
themselves with a different signal (usually SIGTOP)
will not be automatically foregrounded. Some versions
of the linux su(1) command behave this way. Because of
this, a plugin should not set _e_x_e_c___b_a_c_k_g_r_o_u_n_d unless it
is explicitly enabled by the administrator and there
should be a way to enabled or disable it on a per-
command basis.
This setting has no effect unless I/O logging is
enabled or _u_s_e___p_t_y is enabled.
execfd=number
If specified, ssuuddoo will use the fexecve(2) system call
to execute the command instead of execve(2). The
specified _n_u_m_b_e_r must refer to an open file descriptor.
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.
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.
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.
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.
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.
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.
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.
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.
nice=int
Nice value (priority) to use when executing the
command. The nice value, if specified, overrides the
priority associated with the _l_o_g_i_n___c_l_a_s_s on BSD
systems.
noexec=bool
If set, prevent the command from executing other
programs.
preserve_fds=list
A comma-separated list of file descriptors that should
be preserved, regardless of the value of the _c_l_o_s_e_f_r_o_m
setting. Only available starting with API version 1.5.
preserve_groups=bool
If set, ssuuddoo will preserve the user's group vector
instead of initializing the group vector based on
runas_user.
runas_egid=gid
Effective group ID to run the command as. If not
specified, the value of _r_u_n_a_s___g_i_d is used.
runas_euid=uid
Effective user ID to run the command as. If not
specified, the value of _r_u_n_a_s___u_i_d is used.
runas_gid=gid
Group ID to run the command as.
runas_groups=list
The supplementary group vector to use for the command
in the form of a comma-separated list of group IDs. If
_p_r_e_s_e_r_v_e___g_r_o_u_p_s is set, this option is ignored.
runas_uid=uid
User ID to run the command as.
selinux_role=string
SELinux role to use when executing the command.
selinux_type=string
SELinux type to use when executing the command.
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.
sudoedit=bool
Set to true when in _s_u_d_o_e_d_i_t mode. The plugin may
enable _s_u_d_o_e_d_i_t mode even if ssuuddoo was not invoked as
ssuuddooeeddiitt. This allows the plugin to perform command
substitution and transparently enable _s_u_d_o_e_d_i_t when the
user attempts to run an editor.
sudoedit_checkdir=bool
Set to false to disable directory writability checks in
ssuuddooeeddiitt. By default, ssuuddooeeddiitt 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
ssuuddooeeddiitt will refuse to edit a file located in a
writable directory. These restrictions are not
enforced when ssuuddooeeddiitt is run by root. The
_s_u_d_o_e_d_i_t___f_o_l_l_o_w option can be set to false to disable
this check. Only available starting with API version
1.8.
sudoedit_follow=bool
Set to true to allow ssuuddooeeddiitt to edit files that are
symbolic links. By default, ssuuddooeeddiitt 1.8.15 and higher
will refuse to open a symbolic link. The
_s_u_d_o_e_d_i_t___f_o_l_l_o_w option can be used to restore the older
behavior and allow ssuuddooeeddiitt to open symbolic links.
Only available starting with API version 1.8.
timeout=int
Command timeout. If non-zero then when the timeout
expires the command will be killed.
umask=octal
The file creation mask to use when executing the
command.
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,
ssuuddoo will only run the command in a pty when an I/O log
plugin is loaded.
utmp_user=string
User name to use when constructing a new utmp (or
utmpx) entry when _s_e_t___u_t_m_p 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, ssuuddoo will base the new entry on the
invoking user's existing entry.
Unsupported values will be ignored.
argv_out
The NULL-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.
user_env_out
The NULL-terminated environment vector to use when executing
the command. The plugin is responsible for allocating and
populating the vector.
list
int (*list)(int verbose, const char *list_user,
int argc, char * const argv[]);
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 ccoonnvveerrssaattiioonn() or pplluuggiinn__pprriinnttff() function with
SUDO_CONF_ERROR_MSG to present additional error information to the
user.
Privileges should be output via the ccoonnvveerrssaattiioonn() or
pplluuggiinn__pprriinnttff() function using SUDO_CONV_INFO_MSG,
verbose
Flag indicating whether to list in verbose mode or not.
list_user
The name of a different user to list privileges for if the
policy allows it. If NULL, the plugin should list the
privileges of the invoking user.
argc The number of elements in _a_r_g_v, not counting the final NULL
pointer.
argv If non-NULL, 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.
validate
int (*validate)(void);
The vvaalliiddaattee() function is called when ssuuddoo is run with the --vv
flag. For policy plugins such as ssuuddooeerrss that cache authentication
credentials, this function will validate and cache the credentials.
The vvaalliiddaattee() function should be NULL if the plugin does not
support credential caching.
Returns 1 on success, 0 on failure and -1 on error. On error, the
plugin may optionally call the ccoonnvveerrssaattiioonn() or pplluuggiinn__pprriinnttff()
function with SUDO_CONF_ERROR_MSG to present additional error
information to the user.
invalidate
void (*invalidate)(int remove);
The iinnvvaalliiddaattee() function is called when ssuuddoo is called with the --kk
or --KK flag. For policy plugins such as ssuuddooeerrss that cache
authentication credentials, this function will invalidate the
credentials. If the _r_e_m_o_v_e flag is set, the plugin may remove the
credentials instead of simply invalidating them.
The iinnvvaalliiddaattee() function should be NULL if the plugin does not
support credential caching.
init_session
int (*init_session)(struct passwd *pwd, char **user_envp[);
The iinniitt__sseessssiioonn() function is called before ssuuddoo sets up the
execution environment for the command. It is run in the parent
ssuuddoo process and before any uid or gid changes. This can be used
to perform session setup that is not supported by _c_o_m_m_a_n_d___i_n_f_o,
such as opening the PAM session. The cclloossee() function can be used
to tear down the session that was opened by init_session.
The _p_w_d 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 NULL.
The _u_s_e_r___e_n_v argument points to the environment the command will
run in, in the form of a NULL-terminated vector of ``name=value''
strings. This is the same string passed back to the front end via
the Policy Plugin's _u_s_e_r___e_n_v___o_u_t parameter. If the iinniitt__sseessssiioonn()
function needs to modify the user environment, it should update the
pointer stored in _u_s_e_r___e_n_v. The expected use case is to merge the
contents of the PAM environment (if any) with the contents of
_u_s_e_r___e_n_v. NOTE: the _u_s_e_r___e_n_v parameter is only available starting
with API version 1.2. A plugin mmuusstt check the API version
specified by the ssuuddoo front end before using _u_s_e_r___e_n_v. Failure to
do so may result in a crash.
Returns 1 on success, 0 on failure and -1 on error. On error, the
plugin may optionally call the ccoonnvveerrssaattiioonn() or pplluuggiinn__pprriinnttff()
function with SUDO_CONF_ERROR_MSG to present additional error
information to the user.
register_hooks
void (*register_hooks)(int version,
int (*register_hook)(struct sudo_hook *hook));
The rreeggiisstteerr__hhooookkss() function is called by the sudo front end to
register any hooks the plugin needs. If the plugin does not
support hooks, register_hooks should be set to the NULL pointer.
The _v_e_r_s_i_o_n argument describes the version of the hooks API
supported by the ssuuddoo front end.
The rreeggiisstteerr__hhooookk() 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
struct hook does not match the front end's major hook API version.
See the _H_o_o_k _f_u_n_c_t_i_o_n _A_P_I section below for more information about
hooks.
NOTE: the rreeggiisstteerr__hhooookkss() function is only available starting with
API version 1.2. If the ssuuddoo front end doesn't support API version
1.2 or higher, register_hooks will not be called.
deregister_hooks
void (*deregister_hooks)(int version,
int (*deregister_hook)(struct sudo_hook *hook));
The ddeerreeggiisstteerr__hhooookkss() function is called by the sudo front end to
deregister any hooks the plugin has registered. If the plugin does
not support hooks, deregister_hooks should be set to the NULL
pointer.
The _v_e_r_s_i_o_n argument describes the version of the hooks API
supported by the ssuuddoo front end.
The ddeerreeggiisstteerr__hhooookk() function should be used to deregister any
hooks that were put in place by the rreeggiisstteerr__hhooookk() function. If
the plugin tries to deregister a hook that the front end does not
support, deregister_hook will return an error.
See the _H_o_o_k _f_u_n_c_t_i_o_n _A_P_I section below for more information about
hooks.
NOTE: the ddeerreeggiisstteerr__hhooookkss() function is only available starting
with API version 1.2. If the ssuuddoo front end doesn't support API
version 1.2 or higher, deregister_hooks will not be called.
_P_o_l_i_c_y _P_l_u_g_i_n _V_e_r_s_i_o_n _M_a_c_r_o_s
/* 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,\
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 { \
*(vp) = (*(vp) & 0x0000ffff) | ((n) << 16); \
} while(0)
#define SUDO_API_VERSION_SET_MINOR(vp, n) do { \
*(vp) = (*(vp) & 0xffff0000) | (n); \
} while(0)
II//OO pplluuggiinn AAPPII
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));
};
When an I/O plugin is loaded, ssuuddoo 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, ssuuddoo will open a pipe to capture the I/O for
logging before passing it on.
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 lloogg__ssttddiinn(), lloogg__ssttddoouutt() and lloogg__ssttddeerrrr()
functions are only called if the standard input, standard output or
standard error respectively correspond to something other than a tty.
Any of the logging functions may be set to the NULL pointer if no logging
is to be performed. If the open function returns 0, no I/O will be sent
to the plugin.
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.
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.
The io_plugin struct has the following fields:
type The type field should always be set to SUDO_IO_PLUGIN.
version
The version field should be set to SUDO_API_VERSION.
This allows ssuuddoo to determine the API version the plugin was built
against.
open
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[]);
The ooppeenn() function is run before the lloogg__ttttyyiinn(), lloogg__ttttyyoouutt(),
lloogg__ssttddiinn(), lloogg__ssttddoouutt(), lloogg__ssttddeerrrr(), or sshhooww__vveerrssiioonn()
functions are called. It is only called if the version is being
requested or if the policy plugin's cchheecckk__ppoolliiccyy() 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, ssuuddoo will print a usage message before it exits.
If an error occurs, the plugin may optionally call the
ccoonnvveerrssaattiioonn() or pplluuggiinn__pprriinnttff() function with SUDO_CONF_ERROR_MSG
to present additional error information to the user.
The function arguments are as follows:
version
The version passed in by ssuuddoo allows the plugin to determine
the major and minor version number of the plugin API
supported by ssuuddoo.
conversation
A pointer to the ccoonnvveerrssaattiioonn() function that may be used by
the sshhooww__vveerrssiioonn() function to display version information
(see sshhooww__vveerrssiioonn() below). The ccoonnvveerrssaattiioonn() function may
also be used to display additional error message to the user.
The ccoonnvveerrssaattiioonn() function returns 0 on success and -1 on
failure.
plugin_printf
A pointer to a pprriinnttff()-style function that may be used by
the sshhooww__vveerrssiioonn() function to display version information
(see show_version below). The pplluuggiinn__pprriinnttff() function may
also be used to display additional error message to the user.
The pplluuggiinn__pprriinnttff() function returns number of characters
printed on success and -1 on failure.
settings
A vector of user-supplied ssuuddoo settings in the form of
``name=value'' strings. The vector is terminated by a NULL
pointer. These settings correspond to flags the user
specified when running ssuuddoo. As such, they will only be
present when the corresponding flag has been specified on the
command line.
When parsing _s_e_t_t_i_n_g_s, the plugin should split on the ffiirrsstt
equal sign (`=') since the _n_a_m_e field will never include one
itself but the _v_a_l_u_e might.
See the _P_o_l_i_c_y _p_l_u_g_i_n _A_P_I section for a list of all possible
settings.
user_info
A vector of information about the user running the command in
the form of ``name=value'' strings. The vector is terminated
by a NULL pointer.
When parsing _u_s_e_r___i_n_f_o, the plugin should split on the ffiirrsstt
equal sign (`=') since the _n_a_m_e field will never include one
itself but the _v_a_l_u_e might.
See the _P_o_l_i_c_y _p_l_u_g_i_n _A_P_I section for a list of all possible
strings.
argc The number of elements in _a_r_g_v, not counting the final NULL
pointer.
argv If non-NULL, 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.
user_env
The user's environment in the form of a NULL-terminated
vector of ``name=value'' strings.
When parsing _u_s_e_r___e_n_v, the plugin should split on the ffiirrsstt
equal sign (`=') since the _n_a_m_e field will never include one
itself but the _v_a_l_u_e might.
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 NULL-terminated array of strings. If no
arguments were specified, _p_l_u_g_i_n___o_p_t_i_o_n_s will be the NULL
pointer.
NOTE: the _p_l_u_g_i_n___o_p_t_i_o_n_s parameter is only available starting
with API version 1.2. A plugin mmuusstt check the API version
specified by the ssuuddoo front end before using _p_l_u_g_i_n___o_p_t_i_o_n_s.
Failure to do so may result in a crash.
close
void (*close)(int exit_status, int error);
The cclloossee() function is called when the command being run by ssuuddoo
finishes.
The function arguments are as follows:
exit_status
The command's exit status, as returned by the wait(2) system
call. The value of exit_status is undefined if error is non-
zero.
error
If the command could not be executed, this is set to the
value of errno set by the execve(2) system call. If the
command was successfully executed, the value of error is 0.
show_version
int (*show_version)(int verbose);
The sshhooww__vveerrssiioonn() function is called by ssuuddoo when the user
specifies the --VV option. The plugin may display its version
information to the user via the ccoonnvveerrssaattiioonn() or pplluuggiinn__pprriinnttff()
function using SUDO_CONV_INFO_MSG. If the user requests detailed
version information, the verbose flag will be set.
log_ttyin
int (*log_ttyin)(const char *buf, unsigned int len);
The lloogg__ttttyyiinn() 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.
The function arguments are as follows:
buf The buffer containing user input.
len The length of _b_u_f in bytes.
log_ttyout
int (*log_ttyout)(const char *buf, unsigned int len);
The lloogg__ttttyyoouutt() 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.
The function arguments are as follows:
buf The buffer containing command output.
len The length of _b_u_f in bytes.
log_stdin
int (*log_stdin)(const char *buf, unsigned int len);
The lloogg__ssttddiinn() 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.
The function arguments are as follows:
buf The buffer containing user input.
len The length of _b_u_f in bytes.
log_stdout
int (*log_stdout)(const char *buf, unsigned int len);
The lloogg__ssttddoouutt() 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.
The function arguments are as follows:
buf The buffer containing command output.
len The length of _b_u_f in bytes.
log_stderr
int (*log_stderr)(const char *buf, unsigned int len);
The lloogg__ssttddeerrrr() 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.
The function arguments are as follows:
buf The buffer containing command output.
len The length of _b_u_f in bytes.
register_hooks
See the _P_o_l_i_c_y _p_l_u_g_i_n _A_P_I section for a description of
register_hooks.
deregister_hooks
See the _P_o_l_i_c_y _p_l_u_g_i_n _A_P_I section for a description of
deregister_hooks.
_I_/_O _P_l_u_g_i_n _V_e_r_s_i_o_n _M_a_c_r_o_s
Same as for the _P_o_l_i_c_y _p_l_u_g_i_n _A_P_I.
SSiiggnnaall hhaannddlleerrss
The ssuuddoo 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:
++oo SIGALRM
++oo SIGHUP
++oo SIGINT
++oo SIGPIPE
++oo SIGQUIT
++oo SIGTERM
++oo SIGTSTP
++oo SIGUSR1
++oo SIGUSR2
If a fatal signal is received before the command is executed, ssuuddoo will
call the plugin's cclloossee() 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 cclloossee() function. An exception to this is SIGPIPE,
which is ignored until the command is executed.
A plugin may temporarily install its own signal handlers but must restore
the original handler before the plugin function returns.
HHooookk ffuunnccttiioonn AAPPII
Beginning with plugin API version 1.2, it is possible to install hooks
for certain functions called by the ssuuddoo front end.
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 ssuuddoo front end
functions as well.
_H_o_o_k _s_t_r_u_c_t_u_r_e
Hooks in ssuuddoo are described by the following structure:
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;
};
The sudo_hook structure has the following fields:
hook_version
The hook_version field should be set to SUDO_HOOK_VERSION.
hook_type
The hook_type field may be one of the following supported hook
types:
SUDO_HOOK_SETENV
The C library setenv(3) function. Any registered hooks will
run before the C library implementation. The hook_fn field
should be a function that matches the following typedef:
typedef int (*sudo_hook_fn_setenv_t)(const char *name,
const char *value, int overwrite, void *closure);
If the registered hook does not match the typedef the results
are unspecified.
SUDO_HOOK_UNSETENV
The C library unsetenv(3) function. Any registered hooks
will run before the C library implementation. The hook_fn
field should be a function that matches the following
typedef:
typedef int (*sudo_hook_fn_unsetenv_t)(const char *name,
void *closure);
SUDO_HOOK_GETENV
The C library getenv(3) function. Any registered hooks will
run before the C library implementation. The hook_fn field
should be a function that matches the following typedef:
typedef int (*sudo_hook_fn_getenv_t)(const char *name,
char **value, void *closure);
If the registered hook does not match the typedef the results
are unspecified.
SUDO_HOOK_PUTENV
The C library putenv(3) function. Any registered hooks will
run before the C library implementation. The hook_fn field
should be a function that matches the following typedef:
typedef int (*sudo_hook_fn_putenv_t)(char *string,
void *closure);
If the registered hook does not match the typedef the results
are unspecified.
hook_fn
sudo_hook_fn_t hook_fn;
The hook_fn field should be set to the plugin's hook
implementation. The actual function arguments will vary depending
on the hook_type (see hook_type above). In all cases, the closure
field of struct sudo_hook is passed as the last function parameter.
This can be used to pass arbitrary data to the plugin's hook
implementation.
The function return value may be one of the following:
SUDO_HOOK_RET_ERROR
The hook function encountered an error.
SUDO_HOOK_RET_NEXT
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 SUDO_HOOK_RET_NEXT if
the specified variable was not found in the private copy of
the environment.
SUDO_HOOK_RET_STOP
The hook completed without error, stop processing hooks for
this invocation. This can be used to replace the native
implementation. For example, a setenv hook that operates on
a private copy of the environment but leaves environ
unchanged.
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:
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;
_H_o_o_k _A_P_I _V_e_r_s_i_o_n _M_a_c_r_o_s
/* 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,\
SUDO_HOOK_VERSION_MINOR)
For getters and setters see the _P_o_l_i_c_y _p_l_u_g_i_n _A_P_I.
RReemmoottee ccoommmmaanndd eexxeeccuuttiioonn
The ssuuddoo front end does not have native support for running remote
commands. However, starting with ssuuddoo 1.8.8, the --hh option may be used
to specify a remote host that is passed to the policy plugin. A plugin
may also accept a _r_u_n_a_s___u_s_e_r in the form of ``user@hostname'' which will
work with older versions of ssuuddoo. It is anticipated that remote commands
will be supported by executing a ``helper'' program. The policy plugin
should setup the execution environment such that the ssuuddoo front end will
run the helper which, in turn, will connect to the remote host and run
the command.
For example, the policy plugin could utilize sssshh to perform remote
command execution. The helper program would be responsible for running
sssshh 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.
Note that remote ssuuddooeeddiitt functionality must be handled by the policy
plugin, not ssuuddoo 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.
CCoonnvveerrssaattiioonn AAPPII
If the plugin needs to interact with the user, it may do so via the
ccoonnvveerrssaattiioonn() 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 msg
if one is to be printed.
A pprriinnttff()-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.
_C_o_n_v_e_r_s_a_t_i_o_n _f_u_n_c_t_i_o_n _s_t_r_u_c_t_u_r_e_s
The conversation function takes as arguments pointers to the following
structures:
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;
};
Pointers to the ccoonnvveerrssaattiioonn() and pprriinnttff()-style functions are passed in
to the plugin's ooppeenn() function when the plugin is initialized. The
following type definitions can be used in the declaration of the ooppeenn()
function:
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, ...);
To use the ccoonnvveerrssaattiioonn() function, the plugin must pass an array of
sudo_conv_message and sudo_conv_reply structures. There must be a struct
sudo_conv_message and struct sudo_conv_reply for each message in the
conversation. The struct sudo_conv_callback pointer, if not NULL, should
contain function pointers to be called when the ssuuddoo process is suspended
and/or resumed during conversation input. The _o_n___s_u_s_p_e_n_d and _o_n___r_e_s_u_m_e
functions are called with the signal that caused ssuuddoo to be suspended and
the _c_l_o_s_u_r_e pointer from the struct sudo_conv_callback. 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.
The plugin is responsible for freeing the reply buffer located in each
struct sudo_conv_reply, if it is not NULL. SUDO_CONV_REPL_MAX represents
the maximum length of the reply buffer (not including the trailing NUL
character). In practical terms, this is the longest password ssuuddoo will
support. It is also useful as a maximum value for the mmeemmsseett__ss()
function when clearing passwords filled in by the conversation function.
The pprriinnttff()-style function uses the same underlying mechanism as the
ccoonnvveerrssaattiioonn() function but only supports SUDO_CONV_INFO_MSG and
SUDO_CONV_ERROR_MSG for the _m_s_g___t_y_p_e parameter. It can be more
convenient than using the ccoonnvveerrssaattiioonn() function if no user reply is
needed and supports standard pprriinnttff() escape sequences.
See the sample plugin for an example of the ccoonnvveerrssaattiioonn() function
usage.
SSuuddooeerrss ggrroouupp pplluuggiinn AAPPII
The ssuuddooeerrss 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
ssuuddoo, _g_r_o_u_p___f_i_l_e and _s_y_s_t_e_m___g_r_o_u_p, are detailed in sudoers(4). Third
party group plugins include a QAS AD plugin available from Quest
Software.
A group plugin must declare and populate a sudoers_group_plugin struct in
the global scope. This structure contains pointers to the functions that
implement plugin initialization, cleanup and group lookup.
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);
};
The sudoers_group_plugin struct has the following fields:
version
The version field should be set to GROUP_API_VERSION.
This allows ssuuddooeerrss to determine the API version the group plugin
was built against.
init
int (*init)(int version, sudo_printf_t plugin_printf,
char *const argv[]);
The iinniitt() function is called after _s_u_d_o_e_r_s 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 pplluuggiinn__pprriinnttff()
function with SUDO_CONF_ERROR_MSG to present additional error
information to the user.
The function arguments are as follows:
version
The version passed in by ssuuddooeerrss allows the plugin to
determine the major and minor version number of the group
plugin API supported by ssuuddooeerrss.
plugin_printf
A pointer to a pprriinnttff()-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.
argv A NULL-terminated array of arguments generated from the
_g_r_o_u_p___p_l_u_g_i_n option in _s_u_d_o_e_r_s. If no arguments were given,
_a_r_g_v will be NULL.
cleanup
void (*cleanup)();
The cclleeaannuupp() function is called when ssuuddooeerrss has finished its
group checks. The plugin should free any memory it has allocated
and close open file handles.
query
int (*query)(const char *user, const char *group,
const struct passwd *pwd);
The qquueerryy() function is used to ask the group plugin whether _u_s_e_r
is a member of _g_r_o_u_p.
The function arguments are as follows:
user The name of the user being looked up in the external group
database.
group
The name of the group being queried.
pwd The password database entry for _u_s_e_r, if any. If _u_s_e_r is not
present in the password database, _p_w_d will be NULL.
_G_r_o_u_p _A_P_I _V_e_r_s_i_o_n _M_a_c_r_o_s
/* 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) | \
GROUP_API_VERSION_MINOR)
For getters and setters see the _P_o_l_i_c_y _p_l_u_g_i_n _A_P_I.
PPLLUUGGIINN AAPPII CCHHAANNGGEELLOOGG
The following revisions have been made to the Sudo Plugin API.
Version 1.0
Initial API version.
Version 1.1 (sudo 1.8.0)
The I/O logging plugin's ooppeenn() function was modified to take the
command_info list as an argument.
Version 1.2 (sudo 1.8.5)
The Policy and I/O logging plugins' ooppeenn() functions are now passed
a list of plugin parameters if any are specified in sudo.conf(4).
A simple hooks API has been introduced to allow plugins to hook in
to the system's environment handling functions.
The init_session 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.
Version 1.3 (sudo 1.8.7)
Support for the _e_x_e_c___b_a_c_k_g_r_o_u_n_d entry has been added to the
command_info list.
The _m_a_x___g_r_o_u_p_s and _p_l_u_g_i_n___d_i_r entries were added to the settings
list.
The vveerrssiioonn() and cclloossee() functions are now optional. Previously,
a missing vveerrssiioonn() or cclloossee() function would result in a crash.
If no policy plugin cclloossee() function is defined, a default cclloossee()
function will be provided by the ssuuddoo front end that displays a
warning if the command could not be executed.
The ssuuddoo front end now installs default signal handlers to trap
common signals while the plugin functions are run.
Version 1.4 (sudo 1.8.8)
The _r_e_m_o_t_e___h_o_s_t entry was added to the settings list.
Version 1.5 (sudo 1.8.9)
The _p_r_e_s_e_r_v_e___f_d_s entry was added to the command_info list.
Version 1.6 (sudo 1.8.11)
The behavior when an I/O logging plugin returns an error (-1) has
changed. Previously, the ssuuddoo front end took no action when the
lloogg__ttttyyiinn(), lloogg__ttttyyoouutt(), lloogg__ssttddiinn(), lloogg__ssttddoouutt(), or
lloogg__ssttddeerrrr() function returned an error.
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.
Version 1.7 (sudo 1.8.12)
The _p_l_u_g_i_n___p_a_t_h entry was added to the settings list.
The _d_e_b_u_g___f_l_a_g_s 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(4) file.
Version 1.8 (sudo 1.8.15)
The _s_u_d_o_e_d_i_t___c_h_e_c_k_d_i_r and _s_u_d_o_e_d_i_t___f_o_l_l_o_w entries were added to the
command_info list. The default value of _s_u_d_o_e_d_i_t___c_h_e_c_k_d_i_r was
changed to true in sudo 1.8.16.
The sudo _c_o_n_v_e_r_s_a_t_i_o_n function now takes a pointer to a struct
sudo_conv_callback as its fourth argument. The sudo_conv_t
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.
Version 1.9 (sudo 1.8.16)
The _e_x_e_c_f_d entry was added to the command_info list.
SSEEEE AALLSSOO
sudo.conf(4), sudoers(4), sudo(1m)
AAUUTTHHOORRSS
Many people have worked on ssuuddoo over the years; this version consists of
code written primarily by:
Todd C. Miller
See the CONTRIBUTORS file in the ssuuddoo distribution
(https://www.sudo.ws/contributors.html) for an exhaustive list of people
who have contributed to ssuuddoo.
BBUUGGSS
If you feel you have found a bug in ssuuddoo, please submit a bug report at
https://bugzilla.sudo.ws/
SSUUPPPPOORRTT
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.
DDIISSCCLLAAIIMMEERR
ssuuddoo is provided ``AS IS'' 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 ssuuddoo or https://www.sudo.ws/license.html for
complete details.
Sudo 1.8.17 January 20, 2016 Sudo 1.8.17