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