Add a plugin interface to sudo main event loop.

2019-11-15 13:36:01 -07:00
parent 58cede6fee
commit 5793023ffd
17 changed files with 1114 additions and 199 deletions
--- a/doc/sudo_plugin.man.in
+++ b/doc/sudo_plugin.man.in
@@ -16,7 +16,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.TH "SUDO_PLUGIN" "5" "October 20, 2019" "Sudo @PACKAGE_VERSION@" "File Formats Manual"
+.TH "SUDO_PLUGIN" "5" "November 12, 2019" "Sudo @PACKAGE_VERSION@" "File Formats Manual"
 .nh
 .if n .ad l
 .SH "NAME"
@@ -88,6 +88,7 @@ struct policy_plugin {
       int (*register_hook)(struct sudo_hook *hook));
    void (*deregister_hooks)(int version,
       int (*deregister_hook)(struct sudo_hook *hook));
+    struct sudo_plugin_event * (*event_alloc)(void);
 };
 .RE
 .fi
@@ -1154,17 +1155,9 @@ Privileges should be output via the
 or
 \fBplugin_printf\fR()
 function using
-\fRSUDO_CONV_INFO_MSG\fR,
-.TP 6n
-verbose
-Flag indicating whether to list in verbose mode or not.
-.TP 6n
-list_user
-The name of a different user to list privileges for if the policy
-allows it.
-If
-\fRNULL\fR,
-the plugin should list the privileges of the invoking user.
+\fRSUDO_CONV_INFO_MSG\fR.
+.sp
+The function arguments are as follows:
 .TP 6n
 argc
 The number of elements in
@@ -1183,6 +1176,16 @@ 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.
+.TP 6n
+verbose
+Flag indicating whether to list in verbose mode or not.
+.TP 6n
+list_user
+The name of a different user to list privileges for if the policy
+allows it.
+If
+\fRNULL\fR,
+the plugin should list the privileges of the invoking user.
 .PD 0
 .PP
 .RE
@@ -1442,6 +1445,44 @@ version 1.2 or higher,
 \fRderegister_hooks\fR
 will not be called.
 .RE
+.TP 6n
+event_alloc
+.nf
+.RS 6n
+struct sudo_plugin_event * (*event_alloc)(void);
+.RE
+.fi
+.RS 6n
+.sp
+The
+\fBevent_alloc\fR()
+function is used to allocate a
+\fRstruct sudo_plugin_event\fR
+which provides access to the main
+\fBsudo\fR
+event loop.
+Unlike the other fields, the
+\fBevent_alloc\fR()
+pointer is filled in by the
+\fBsudo\fR
+front end, not by the plugin.
+.sp
+See the
+\fIEvent API\fR
+section below for more information
+about events.
+.sp
+NOTE: the
+\fBevent_alloc\fR()
+function is only available starting
+with API version 1.15.
+If the
+\fBsudo\fR
+front end doesn't support API
+version 1.15 or higher,
+\fBevent_alloc\fR()
+will not be set.
+.RE
 .PP
 \fIPolicy Plugin Version Macros\fR
 .nf
@@ -1490,6 +1531,7 @@ struct io_plugin {
       int (*deregister_hook)(struct sudo_hook *hook));
    int (*change_winsize)(unsigned int lines, unsigned int cols);
    int (*log_suspend)(int signo);
+    struct sudo_plugin_event * (*event_alloc)(void);
 };
 .RE
 .fi
@@ -2049,6 +2091,44 @@ Returns \-1 if an error occurred, in which case no further calls to
 \fBlog_suspend\fR()
 will be made,
 .RE
+.TP 6n
+event_alloc
+.nf
+.RS 6n
+struct sudo_plugin_event * (*event_alloc)(void);
+.RE
+.fi
+.RS 6n
+.sp
+The
+\fBevent_alloc\fR()
+function is used to allocate a
+\fRstruct sudo_plugin_event\fR
+which provides access to the main
+\fBsudo\fR
+event loop.
+Unlike the other fields, the
+\fBevent_alloc\fR()
+pointer is filled in by the
+\fBsudo\fR
+front end, not by the plugin.
+.sp
+See the
+\fIEvent API\fR
+section below for more information
+about events.
+.sp
+NOTE: the
+\fBevent_alloc\fR()
+function is only available starting
+with API version 1.15.
+If the
+\fBsudo\fR
+front end doesn't support API
+version 1.15 or higher,
+\fBevent_alloc\fR()
+will not be set.
+.RE
 .PP
 \fII/O Plugin Version Macros\fR
 .PP
@@ -2338,6 +2418,295 @@ return SUDO_HOOK_RET_STOP;
 .PP
 For getters and setters see the
 \fIPolicy plugin API\fR.
+.SS "Event API"
+When
+\fBsudo\fR
+runs a command, it uses an event loop to service signals and I/O.
+Events may be triggered based on time, a file or socket descriptor
+becoming ready, or due to receipt of a signal.
+Starting with API version 1.15, it is possible for a plugin to
+participate in this event loop by calling the
+\fBevent_alloc\fR()
+function.
+.PP
+\fIEvent structure\fR
+.PP
+Events are described by the following structure:
+.nf
+.RS 0n
+typedef void (*sudo_plugin_ev_callback_t)(int fd, int what,
+    void *closure);
+
+struct sudo_plugin_event {
+    int (*set)(struct sudo_plugin_event *pev, int fd, int events,
+        sudo_plugin_ev_callback_t callback, void *closure);
+    int (*add)(struct sudo_plugin_event *pev, struct timespec *timeout);
+    int (*del)(struct sudo_plugin_event *pev);
+    int (*timeleft)(struct sudo_plugin_event *pev, struct timespec *ts);
+    int (*fd)(struct sudo_plugin_event *pev);
+    void (*setbase)(struct sudo_plugin_event *pev, void *base);
+    void (*loopbreak)(struct sudo_plugin_event *pev);
+    void (*free)(struct sudo_plugin_event *pev);
+};
+.RE
+.fi
+.PP
+The sudo_plugin_event struct contains the following function pointers:
+.TP 6n
+\fBset\fR()
+.br
+.nf
+.RS 6n
+int (*set)(struct sudo_plugin_event *pev, int fd, int events,
+    sudo_plugin_ev_callback_t callback, void *closure);
+.RE
+.fi
+.RS 6n
+.sp
+The
+\fBset\fR()
+function takes the following arguments:
+.TP 6n
+struct sudo_plugin_event *\fIpev\fR
+A pointer to the struct sudo_plugin_event itself.
+.TP 6n
+\fIfd\fR
+The file or socket descriptor for I/O-based events or the signal
+number for signal events.
+For time-based events,
+\fIfd\fR
+must be -1.
+.TP 6n
+\fIevents\fR
+The following values determine what will trigger the event callback:
+.PP
+.RS 6n
+.PD 0
+.TP 6n
+SUDO_PLUGIN_EV_TIMEOUT
+callback is run after the specified timeout expires
+.PD
+.TP 6n
+SUDO_PLUGIN_EV_READ
+callback is run when the file descriptor is readable
+.TP 6n
+SUDO_PLUGIN_EV_WRITE
+callback is run when the file descriptor is writable
+.TP 6n
+SUDO_PLUGIN_EV_PERSIST
+event is persistent and remains enabled until explicitly deleted
+.TP 6n
+SUDO_PLUGIN_EV_SIGNAL
+callback is run when the specified signal is received
+.PP
+The
+\fRSUDO_PLUGIN_EV_PERSIST\fR
+flag may be ORed with any of the event types.
+It is also possible to OR
+\fRSUDO_PLUGIN_EV_READ\fR
+and
+\fRSUDO_PLUGIN_EV_WRITE\fR
+together to run the callback when a descriptor is ready to be
+either read from or written to.
+All other event values are mutually exclusive.
+.RE
+.TP 6n
+sudo_plugin_ev_callback_t \fIcallback\fR
+.nf
+.RS 6n
+typedef void (*sudo_plugin_ev_callback_t)(int fd, int what,
+    void *closure);
+.RE
+.fi
+.RS 6n
+.sp
+The function to call when an event is triggered.
+The
+\fBcallback\fR()
+function is run with the following arguments:
+.TP 6n
+\fIfd\fR
+The file or socket descriptor for I/O-based events or the signal
+number for signal events.
+.TP 6n
+\fIwhat\fR
+The event type that triggered that callback.
+For events that have multiple event types (for example
+\fRSUDO_PLUGIN_EV_READ\fR
+and
+\fRSUDO_PLUGIN_EV_WRITE\fR)
+or have an associated timeout,
+\fIwhat\fR
+can be used to determine why the callback was run.
+.TP 6n
+\fIclosure\fR
+The generic pointer that was specified in the
+\fBset\fR()
+function.
+.PD 0
+.PP
+.RE
+.PD
+.TP 6n
+closure
+A generic pointer that will be passed to the callback function.
+.PP
+The
+\fBset\fR()
+function returns 1 on success, and \-1 if a error occurred.
+.RE
+.TP 6n
+\fBadd\fR()
+.br
+.nf
+.RS 6n
+int (*add)(struct sudo_plugin_event *pev, struct timespec *timeout);
+.RE
+.fi
+.RS 6n
+.sp
+The
+\fBadd\fR()
+function adds the event
+\fIpev\fR
+to
+\fBsudo\fR's
+event loop.
+The event must have previously been initialized via the
+\fBset\fR()
+function.
+If the
+\fItimeout\fR
+argument is not NULL, it should specify a (relative) timeout after
+which the event will be triggered if the main event criteria has
+not been met.
+This is often used to implement an I/O timeout where the event
+will fire if a descriptor is not ready within a certain time
+period.
+If the event is already present in the event loop, its
+\fItimeout\fR
+will be adjusted to match the new value, if any.
+.sp
+The
+\fBadd\fR()
+function returns 1 on success, and \-1 if a error occurred.
+.RE
+.TP 6n
+\fBdel\fR()
+.br
+.nf
+.RS 6n
+int (*del)(struct sudo_plugin_event *pev);
+.RE
+.fi
+.RS 6n
+.sp
+The
+\fBdel\fR()
+function deletes the event
+\fIpev\fR
+from
+\fBsudo\fR's
+event loop.
+Deleted events can be added back via the
+\fBadd\fR()
+function.
+.sp
+The
+\fBdel\fR()
+function returns 1 on success, and \-1 if a error occurred.
+.RE
+.TP 6n
+\fBtimeleft\fR()
+.nf
+.RS 6n
+int (*timeleft)(struct sudo_plugin_event *pev, struct timespec *ts);
+.RE
+.fi
+.RS 6n
+.sp
+The
+\fBtimeleft\fR()
+function can be used to determine how much time remains in an event's
+timeout, if one was specified when the event was added.
+The
+\fIts\fR
+pointer is filled in with the remaining time.
+.sp
+The
+\fBtimeleft\fR()
+function returns 1 on success, and \-1 if the event has no associated timeout.
+.RE
+.TP 6n
+\fBfd\fR()
+.nf
+.RS 6n
+int (*fd)(struct sudo_plugin_event *pev);
+.RE
+.fi
+.RS 6n
+.sp
+The
+\fBfd\fR()
+function returns the descriptor or signal number associated with
+the event
+\fIpev\fR.
+.RE
+.TP 6n
+\fBsetbase\fR()
+.nf
+.RS 6n
+void (*setbase)(struct sudo_plugin_event *pev, void *base);
+.RE
+.fi
+.RS 6n
+.sp
+The
+\fBsetbase\fR()
+function sets the underlying event
+\fIbase\fR
+for
+\fIpev\fR
+to the specified value.
+This can be used to move an event created via
+\fBevent_alloc\fR()
+to a new event loop allocated by sudo's event subsystem.
+Using this function requires linking the plugin with the sudo_util
+library.
+It is unlikely to be used outside of the
+\fBsudoers\fR
+plugin.
+.RE
+.TP 6n
+\fBloopbreak\fR()
+.nf
+.RS 6n
+void (*loopbreak)(struct sudo_plugin_event *pev);
+.RE
+.fi
+.RS 6n
+.sp
+The
+\fBloopbreak\fR()
+function causes
+\fBsudo\fR's
+event loop to exit immediately and the running command to be terminated.
+.RE
+.TP 6n
+\fBfree\fR()
+.nf
+.RS 6n
+void (*free)(struct sudo_plugin_event *pev);
+.RE
+.fi
+.RS 6n
+.sp
+The
+\fBfree\fR()
+function deletes the event
+\fIpev\fR
+from the event loop and frees the memory associated with it.
+.RE
 .SS "Remote command execution"
 The
 \fBsudo\fR
@@ -2966,6 +3335,11 @@ The
 entry was added to the
 \fRcommand_info\fR
 list.
+.TP 6n
+Version 1.15 (sudo 1.9.0)
+The
+\fIevent_alloc\fR
+field was added to the policy_plugin and io_plugin structs.
 .SH "SEE ALSO"
 sudo.conf(@mansectform@),
 sudoers(@mansectform@),
--- a/doc/sudo_plugin.mdoc.in
+++ b/doc/sudo_plugin.mdoc.in
@@ -15,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd October 20, 2019
+.Dd November 12, 2019
 .Dt SUDO_PLUGIN @mansectform@
 .Os Sudo @PACKAGE_VERSION@
 .Sh NAME
@@ -85,6 +85,7 @@ struct policy_plugin {
       int (*register_hook)(struct sudo_hook *hook));
    void (*deregister_hooks)(int version,
       int (*deregister_hook)(struct sudo_hook *hook));
+    struct sudo_plugin_event * (*event_alloc)(void);
 };
 .Ed
 .Pp
@@ -1016,16 +1017,10 @@ Privileges should be output via the
 or
 .Fn plugin_printf
 function using
-.Dv SUDO_CONV_INFO_MSG ,
+.Dv SUDO_CONV_INFO_MSG .
+.Pp
+The function arguments are as follows:
 .Bl -tag -width 4n
-.It verbose
-Flag indicating whether to list in verbose mode or not.
-.It list_user
-The name of a different user to list privileges for if the policy
-allows it.
-If
-.Dv NULL ,
-the plugin should list the privileges of the invoking user.
 .It argc
 The number of elements in
 .Em argv ,
@@ -1042,6 +1037,14 @@ be passed to the
 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.
+.It verbose
+Flag indicating whether to list in verbose mode or not.
+.It list_user
+The name of a different user to list privileges for if the policy
+allows it.
+If
+.Dv NULL ,
+the plugin should list the privileges of the invoking user.
 .El
 .It validate
 .Bd -literal -compact
@@ -1273,6 +1276,39 @@ front end doesn't support API
 version 1.2 or higher,
 .Li deregister_hooks
 will not be called.
+.It event_alloc
+.Bd -literal -compact
+struct sudo_plugin_event * (*event_alloc)(void);
+.Ed
+.Pp
+The
+.Fn event_alloc
+function is used to allocate a
+.Li struct sudo_plugin_event
+which provides access to the main
+.Nm sudo
+event loop.
+Unlike the other fields, the
+.Fn event_alloc
+pointer is filled in by the
+.Nm sudo
+front end, not by the plugin.
+.Pp
+See the
+.Sx Event API
+section below for more information
+about events.
+.Pp
+NOTE: the
+.Fn event_alloc
+function is only available starting
+with API version 1.15.
+If the
+.Nm sudo
+front end doesn't support API
+version 1.15 or higher,
+.Fn event_alloc
+will not be set.
 .El
 .Pp
 .Em Policy Plugin Version Macros
@@ -1318,6 +1354,7 @@ struct io_plugin {
       int (*deregister_hook)(struct sudo_hook *hook));
    int (*change_winsize)(unsigned int lines, unsigned int cols);
    int (*log_suspend)(int signo);
+    struct sudo_plugin_event * (*event_alloc)(void);
 };
 .Ed
 .Pp
@@ -1793,6 +1830,39 @@ the command was suspended during playback of a session.
 Returns \-1 if an error occurred, in which case no further calls to
 .Fn log_suspend
 will be made,
+.It event_alloc
+.Bd -literal -compact
+struct sudo_plugin_event * (*event_alloc)(void);
+.Ed
+.Pp
+The
+.Fn event_alloc
+function is used to allocate a
+.Li struct sudo_plugin_event
+which provides access to the main
+.Nm sudo
+event loop.
+Unlike the other fields, the
+.Fn event_alloc
+pointer is filled in by the
+.Nm sudo
+front end, not by the plugin.
+.Pp
+See the
+.Sx Event API
+section below for more information
+about events.
+.Pp
+NOTE: the
+.Fn event_alloc
+function is only available starting
+with API version 1.15.
+If the
+.Nm sudo
+front end doesn't support API
+version 1.15 or higher,
+.Fn event_alloc
+will not be set.
 .El
 .Pp
 .Em I/O Plugin Version Macros
@@ -2028,6 +2098,234 @@ return SUDO_HOOK_RET_STOP;
 .Pp
 For getters and setters see the
 .Sx Policy plugin API .
+.Ss Event API
+When
+.Nm sudo
+runs a command, it uses an event loop to service signals and I/O.
+Events may be triggered based on time, a file or socket descriptor
+becoming ready, or due to receipt of a signal.
+Starting with API version 1.15, it is possible for a plugin to
+participate in this event loop by calling the
+.Fn event_alloc
+function.
+.Pp
+.Em Event structure
+.Pp
+Events are described by the following structure:
+.Pp
+.Bd -literal -compact
+typedef void (*sudo_plugin_ev_callback_t)(int fd, int what,
+    void *closure);
+
+struct sudo_plugin_event {
+    int (*set)(struct sudo_plugin_event *pev, int fd, int events,
+        sudo_plugin_ev_callback_t callback, void *closure);
+    int (*add)(struct sudo_plugin_event *pev, struct timespec *timeout);
+    int (*del)(struct sudo_plugin_event *pev);
+    int (*timeleft)(struct sudo_plugin_event *pev, struct timespec *ts);
+    int (*fd)(struct sudo_plugin_event *pev);
+    void (*setbase)(struct sudo_plugin_event *pev, void *base);
+    void (*loopbreak)(struct sudo_plugin_event *pev);
+    void (*free)(struct sudo_plugin_event *pev);
+};
+.Ed
+.Pp
+The sudo_plugin_event struct contains the following function pointers:
+.Bl -tag -width 4n
+.It Fn set
+.Bd -literal -compact
+int (*set)(struct sudo_plugin_event *pev, int fd, int events,
+    sudo_plugin_ev_callback_t callback, void *closure);
+.Ed
+.Pp
+The
+.Fn set
+function takes the following arguments:
+.Bl -tag -width 4n
+.It struct sudo_plugin_event * Ns Fa pev
+A pointer to the struct sudo_plugin_event itself.
+.It Fa fd
+The file or socket descriptor for I/O-based events or the signal
+number for signal events.
+For time-based events,
+.Fa fd
+must be -1.
+.It Fa events
+The following values determine what will trigger the event callback:
+.Bl -tag -width 4n
+.It SUDO_PLUGIN_EV_TIMEOUT
+callback is run after the specified timeout expires
+.It SUDO_PLUGIN_EV_READ
+callback is run when the file descriptor is readable
+.It SUDO_PLUGIN_EV_WRITE
+callback is run when the file descriptor is writable
+.It SUDO_PLUGIN_EV_PERSIST
+event is persistent and remains enabled until explicitly deleted
+.It SUDO_PLUGIN_EV_SIGNAL
+callback is run when the specified signal is received
+.El
+.Pp
+The
+.Ev SUDO_PLUGIN_EV_PERSIST
+flag may be ORed with any of the event types.
+It is also possible to OR
+.Ev SUDO_PLUGIN_EV_READ
+and
+.Ev SUDO_PLUGIN_EV_WRITE
+together to run the callback when a descriptor is ready to be
+either read from or written to.
+All other event values are mutually exclusive.
+.It sudo_plugin_ev_callback_t Fa callback
+.Bd -literal -compact
+typedef void (*sudo_plugin_ev_callback_t)(int fd, int what,
+    void *closure);
+.Ed
+.Pp
+The function to call when an event is triggered.
+The
+.Fn callback
+function is run with the following arguments:
+.Bl -tag -width 4n
+.It Fa fd
+The file or socket descriptor for I/O-based events or the signal
+number for signal events.
+.It Fa what
+The event type that triggered that callback.
+For events that have multiple event types (for example
+.Ev SUDO_PLUGIN_EV_READ
+and
+.Ev SUDO_PLUGIN_EV_WRITE )
+or have an associated timeout,
+.Fa what
+can be used to determine why the callback was run.
+.It Fa closure
+The generic pointer that was specified in the
+.Fn set
+function.
+.El
+.It closure
+A generic pointer that will be passed to the callback function.
+.El
+.Pp
+The
+.Fn set
+function returns 1 on success, and \-1 if a error occurred.
+.It Fn add
+.Bd -literal -compact
+int (*add)(struct sudo_plugin_event *pev, struct timespec *timeout);
+.Ed
+.Pp
+The
+.Fn add
+function adds the event
+.Fa pev
+to
+.Nm sudo Ns No 's
+event loop.
+The event must have previously been initialized via the
+.Fn set
+function.
+If the
+.Fa timeout
+argument is not NULL, it should specify a (relative) timeout after
+which the event will be triggered if the main event criteria has
+not been met.
+This is often used to implement an I/O timeout where the event
+will fire if a descriptor is not ready within a certain time
+period.
+If the event is already present in the event loop, its
+.Fa timeout
+will be adjusted to match the new value, if any.
+.Pp
+The
+.Fn add
+function returns 1 on success, and \-1 if a error occurred.
+.It Fn del
+.Bd -literal -compact
+int (*del)(struct sudo_plugin_event *pev);
+.Ed
+.Pp
+The
+.Fn del
+function deletes the event
+.Fa pev
+from
+.Nm sudo Ns No 's
+event loop.
+Deleted events can be added back via the
+.Fn add
+function.
+.Pp
+The
+.Fn del
+function returns 1 on success, and \-1 if a error occurred.
+.It Fn timeleft
+.Bd -literal -compact
+int (*timeleft)(struct sudo_plugin_event *pev, struct timespec *ts);
+.Ed
+.Pp
+The
+.Fn timeleft
+function can be used to determine how much time remains in an event's
+timeout, if one was specified when the event was added.
+The
+.Fa ts
+pointer is filled in with the remaining time.
+.Pp
+The
+.Fn timeleft
+function returns 1 on success, and \-1 if the event has no associated timeout.
+.It Fn fd
+.Bd -literal -compact
+int (*fd)(struct sudo_plugin_event *pev);
+.Ed
+.Pp
+The
+.Fn fd
+function returns the descriptor or signal number associated with
+the event
+.Fa pev .
+.It Fn setbase
+.Bd -literal -compact
+void (*setbase)(struct sudo_plugin_event *pev, void *base);
+.Ed
+.Pp
+The
+.Fn setbase
+function sets the underlying event
+.Fa base
+for
+.Fa pev
+to the specified value.
+This can be used to move an event created via
+.Fn event_alloc
+to a new event loop allocated by sudo's event subsystem.
+Using this function requires linking the plugin with the sudo_util
+library.
+It is unlikely to be used outside of the
+.Nm sudoers
+plugin.
+.It Fn loopbreak
+.Bd -literal -compact
+void (*loopbreak)(struct sudo_plugin_event *pev);
+.Ed
+.Pp
+The
+.Fn loopbreak
+function causes
+.Nm sudo Ns No 's
+event loop to exit immediately and the running command to be terminated.
+.It Fn free
+.Bd -literal -compact
+void (*free)(struct sudo_plugin_event *pev);
+.Ed
+.Pp
+The
+.Fn free
+function deletes the event
+.Fa pev
+from the event loop and frees the memory associated with it.
+.El
 .Ss Remote command execution
 The
 .Nm sudo
@@ -2603,6 +2901,10 @@ The
 entry was added to the
 .Li command_info
 list.
+.It Version 1.15 (sudo 1.9.0)
+The
+.Em event_alloc
+field was added to the policy_plugin and io_plugin structs.
 .El
 .Sh SEE ALSO
 .Xr sudo.conf @mansectform@ ,
--- a/include/sudo_event.h
+++ b/include/sudo_event.h
@@ -22,7 +22,7 @@
 #include <signal.h>	/* for sigatomic_t and NSIG */
 #include "sudo_queue.h"

-/* Event types */
+/* Event types (keep in sync with sudo_plugin.h) */
 #define SUDO_EV_TIMEOUT		0x01	/* fire after timeout */
 #define SUDO_EV_READ		0x02	/* fire when readable */
 #define SUDO_EV_WRITE		0x04	/* fire when writable */
@@ -48,6 +48,7 @@
 #define SUDO_EVBASE_GOT_BREAK	0x20
 #define SUDO_EVBASE_GOT_MASK	0xf0

+/* Must match sudo_plugin_ev_callback_t in sudo_plugin.h */
 typedef void (*sudo_ev_callback_t)(int fd, int what, void *closure);

 /*
@@ -125,6 +126,10 @@ __dso_public struct sudo_event *sudo_ev_alloc_v1(int fd, short events, sudo_ev_c
 __dso_public void sudo_ev_free_v1(struct sudo_event *ev);
 #define sudo_ev_free(_a) sudo_ev_free_v1((_a))

+/* Set an event struct that was pre-allocated. */
+__dso_public int sudo_ev_set_v1(struct sudo_event *ev, int fd, short events, sudo_ev_callback_t callback, void *closure);
+#define sudo_ev_set(_a, _b, _c, _d, _e) sudo_ev_set_v1((_a), (_b), (_c), (_d), (_e))
+
 /* Add an event, returns 0 on success, -1 on error */
 __dso_public int sudo_ev_add_v1(struct sudo_event_base *head, struct sudo_event *ev, struct timeval *timo, bool tohead);
 __dso_public int sudo_ev_add_v2(struct sudo_event_base *head, struct sudo_event *ev, struct timespec *timo, bool tohead);
--- a/include/sudo_plugin.h
+++ b/include/sudo_plugin.h
@@ -21,7 +21,7 @@

 /* API version major/minor */
 #define SUDO_API_VERSION_MAJOR 1
-#define SUDO_API_VERSION_MINOR 14
+#define SUDO_API_VERSION_MINOR 15
 #define SUDO_API_MKVERSION(x, y) (((x) << 16) | (y))
 #define SUDO_API_VERSION SUDO_API_MKVERSION(SUDO_API_VERSION_MAJOR, SUDO_API_VERSION_MINOR)

@@ -128,7 +128,32 @@ struct sudo_hook {
 #define SUDO_HOOK_PUTENV	3
 #define SUDO_HOOK_GETENV	4

-/* Policy plugin type and defines */
+/*
+ * Plugin interface to sudo's main event loop.
+ */
+typedef void (*sudo_plugin_ev_callback_t)(int fd, int what, void *closure);
+
+struct timespec;
+struct sudo_plugin_event {
+    int (*set)(struct sudo_plugin_event *pev, int fd, int events, sudo_plugin_ev_callback_t callback, void *closure);
+    int (*add)(struct sudo_plugin_event *pev, struct timespec *timeout);
+    int (*del)(struct sudo_plugin_event *pev);
+    int (*timeleft)(struct sudo_plugin_event *pev, struct timespec *ts);
+    int (*fd)(struct sudo_plugin_event *pev);
+    void (*setbase)(struct sudo_plugin_event *pev, void *base);
+    void (*loopbreak)(struct sudo_plugin_event *pev);
+    void (*free)(struct sudo_plugin_event *pev);
+    /* actually larger... */
+};
+
+/* Sudo plugin Event types */
+#define SUDO_PLUGIN_EV_TIMEOUT	0x01	/* fire after timeout */
+#define SUDO_PLUGIN_EV_READ	0x02	/* fire when readable */
+#define SUDO_PLUGIN_EV_WRITE	0x04	/* fire when writable */
+#define SUDO_PLUGIN_EV_PERSIST	0x08	/* persist until deleted */
+#define SUDO_PLUGIN_EV_SIGNAL	0x10	/* fire on signal receipt */
+
+/* Policy plugin type and defines. */
 struct passwd;
 struct policy_plugin {
 #define SUDO_POLICY_PLUGIN     1
@@ -150,9 +175,10 @@ struct policy_plugin {
    int (*init_session)(struct passwd *pwd, char **user_env_out[]);
    void (*register_hooks)(int version, int (*register_hook)(struct sudo_hook *hook));
    void (*deregister_hooks)(int version, int (*deregister_hook)(struct sudo_hook *hook));
+    struct sudo_plugin_event * (*event_alloc)(void);
 };

-/* I/O plugin type and defines */
+/* I/O plugin type and defines. */
 struct io_plugin {
 #define SUDO_IO_PLUGIN	    2
    unsigned int type; /* always SUDO_IO_PLUGIN */
@@ -173,6 +199,7 @@ struct io_plugin {
    void (*deregister_hooks)(int version, int (*deregister_hook)(struct sudo_hook *hook));
    int (*change_winsize)(unsigned int line, unsigned int cols);
    int (*log_suspend)(int signo);
+    struct sudo_plugin_event * (*event_alloc)(void);
 };

 /* Sudoers group plugin version major/minor */
--- a/lib/util/event.c
+++ b/lib/util/event.c
@@ -284,6 +284,33 @@ sudo_ev_init(struct sudo_event *ev, int fd, short events,
    debug_return;
 }

+/*
+ * Set a pre-allocated struct sudo_event.
+ * Allocates space for siginfo_t for SUDO_EV_SIGINFO as needed.
+ */
+int
+sudo_ev_set_v1(struct sudo_event *ev, int fd, short events,
+    sudo_ev_callback_t callback, void *closure)
+{
+    debug_decl(sudo_ev_set, SUDO_DEBUG_EVENT)
+
+    /* For SUDO_EV_SIGINFO we use a container to store closure + siginfo_t */
+    if (ISSET(events, SUDO_EV_SIGINFO)) {
+	struct sudo_ev_siginfo_container *container =
+	    malloc(sizeof(*container) + sizeof(siginfo_t) - 1);
+	if (container == NULL) {
+	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+		"%s: unable to allocate siginfo container", __func__);
+	    debug_return_int(-1);
+	}
+	container->closure = closure;
+	closure = container;
+    }
+    sudo_ev_init(ev, fd, events, callback, closure);
+
+    debug_return_int(0);
+}
+
 struct sudo_event *
 sudo_ev_alloc_v1(int fd, short events, sudo_ev_callback_t callback, void *closure)
 {
@@ -296,21 +323,10 @@ sudo_ev_alloc_v1(int fd, short events, sudo_ev_callback_t callback, void *closur
 	    "%s: unable to allocate event", __func__);
 	debug_return_ptr(NULL);
    }
-    /* For SUDO_EV_SIGINFO we use a container to store closure + siginfo_t */
-    if (ISSET(events, SUDO_EV_SIGINFO)) {
-	struct sudo_ev_siginfo_container *container =
-	    malloc(sizeof(*container) + sizeof(siginfo_t) - 1);
-	if (container == NULL) {
-	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
-		"%s: unable to allocate siginfo container", __func__);
+    if (sudo_ev_set(ev, fd, events, callback, closure) == -1) {
 	free(ev);
 	debug_return_ptr(NULL);
    }
-	container->closure = closure;
-	closure = container;
-    }
-    sudo_ev_init(ev, fd, events, callback, closure);
-
    debug_return_ptr(ev);
 }

--- a/plugins/sudoers/iolog.c
+++ b/plugins/sudoers/iolog.c
@@ -828,5 +828,6 @@ __dso_public struct io_plugin sudoers_io = {
    NULL, /* register_hooks */
    NULL, /* deregister_hooks */
    sudoers_io_change_winsize,
-    sudoers_io_suspend
+    sudoers_io_suspend,
+    NULL /* event_alloc() filled in by sudo */
 };
--- a/plugins/sudoers/policy.c
+++ b/plugins/sudoers/policy.c
@@ -1003,5 +1003,6 @@ __dso_public struct policy_plugin sudoers_policy = {
    sudoers_policy_validate,
    sudoers_policy_invalidate,
    sudoers_policy_init_session,
-    sudoers_policy_register_hooks
+    sudoers_policy_register_hooks,
+    NULL /* event_alloc() filled in by sudo */
 };
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -318,17 +318,19 @@ check_ttyname.plog: check_ttyname.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/regress/ttyname/check_ttyname.c --i-file $< --output-file $@
 conversation.o: $(srcdir)/conversation.c $(incdir)/compat/stdbool.h \
                $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-                $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-                $(incdir)/sudo_gettext.h $(incdir)/sudo_plugin.h \
-                $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+                $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+                $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+                $(incdir)/sudo_plugin.h $(incdir)/sudo_queue.h \
+                $(incdir)/sudo_util.h $(srcdir)/sudo.h \
                $(srcdir)/sudo_plugin_int.h $(top_builddir)/config.h \
                $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/conversation.c
 conversation.i: $(srcdir)/conversation.c $(incdir)/compat/stdbool.h \
                $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-                $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-                $(incdir)/sudo_gettext.h $(incdir)/sudo_plugin.h \
-                $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+                $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+                $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+                $(incdir)/sudo_plugin.h $(incdir)/sudo_queue.h \
+                $(incdir)/sudo_util.h $(srcdir)/sudo.h \
                $(srcdir)/sudo_plugin_int.h $(top_builddir)/config.h \
                $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
@@ -337,18 +339,18 @@ conversation.plog: conversation.i
 env_hooks.o: $(srcdir)/env_hooks.c $(incdir)/compat/stdbool.h \
             $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
             $(incdir)/sudo_debug.h $(incdir)/sudo_dso.h \
-             $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
-             $(incdir)/sudo_plugin.h $(incdir)/sudo_queue.h \
-             $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
-             $(top_builddir)/pathnames.h
+             $(incdir)/sudo_event.h $(incdir)/sudo_fatal.h \
+             $(incdir)/sudo_gettext.h $(incdir)/sudo_plugin.h \
+             $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+             $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/env_hooks.c
 env_hooks.i: $(srcdir)/env_hooks.c $(incdir)/compat/stdbool.h \
             $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
             $(incdir)/sudo_debug.h $(incdir)/sudo_dso.h \
-             $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
-             $(incdir)/sudo_plugin.h $(incdir)/sudo_queue.h \
-             $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
-             $(top_builddir)/pathnames.h
+             $(incdir)/sudo_event.h $(incdir)/sudo_fatal.h \
+             $(incdir)/sudo_gettext.h $(incdir)/sudo_plugin.h \
+             $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+             $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 env_hooks.plog: env_hooks.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/env_hooks.c --i-file $< --output-file $@
@@ -370,17 +372,19 @@ exec.plog: exec.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/exec.c --i-file $< --output-file $@
 exec_common.o: $(srcdir)/exec_common.c $(incdir)/compat/stdbool.h \
               $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-               $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-               $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-               $(incdir)/sudo_util.h $(srcdir)/sudo.h $(srcdir)/sudo_exec.h \
-               $(top_builddir)/config.h $(top_builddir)/pathnames.h
+               $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+               $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+               $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+               $(srcdir)/sudo_exec.h $(top_builddir)/config.h \
+               $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/exec_common.c
 exec_common.i: $(srcdir)/exec_common.c $(incdir)/compat/stdbool.h \
               $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-               $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-               $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-               $(incdir)/sudo_util.h $(srcdir)/sudo.h $(srcdir)/sudo_exec.h \
-               $(top_builddir)/config.h $(top_builddir)/pathnames.h
+               $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+               $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+               $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+               $(srcdir)/sudo_exec.h $(top_builddir)/config.h \
+               $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 exec_common.plog: exec_common.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/exec_common.c --i-file $< --output-file $@
@@ -446,65 +450,67 @@ exec_pty.plog: exec_pty.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/exec_pty.c --i-file $< --output-file $@
 get_pty.o: $(srcdir)/get_pty.c $(incdir)/compat/stdbool.h \
           $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-           $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-           $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-           $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
-           $(top_builddir)/pathnames.h
+           $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+           $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+           $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+           $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/get_pty.c
 get_pty.i: $(srcdir)/get_pty.c $(incdir)/compat/stdbool.h \
           $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-           $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-           $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-           $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
-           $(top_builddir)/pathnames.h
+           $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+           $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+           $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+           $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 get_pty.plog: get_pty.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/get_pty.c --i-file $< --output-file $@
 hooks.o: $(srcdir)/hooks.c $(incdir)/compat/stdbool.h $(incdir)/sudo_compat.h \
-         $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-         $(incdir)/sudo_gettext.h $(incdir)/sudo_plugin.h \
-         $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
-         $(srcdir)/sudo_plugin_int.h $(top_builddir)/config.h \
+         $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+         $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+         $(incdir)/sudo_plugin.h $(incdir)/sudo_queue.h $(incdir)/sudo_util.h \
+         $(srcdir)/sudo.h $(srcdir)/sudo_plugin_int.h $(top_builddir)/config.h \
         $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/hooks.c
 hooks.i: $(srcdir)/hooks.c $(incdir)/compat/stdbool.h $(incdir)/sudo_compat.h \
-         $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-         $(incdir)/sudo_gettext.h $(incdir)/sudo_plugin.h \
-         $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
-         $(srcdir)/sudo_plugin_int.h $(top_builddir)/config.h \
+         $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+         $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+         $(incdir)/sudo_plugin.h $(incdir)/sudo_queue.h $(incdir)/sudo_util.h \
+         $(srcdir)/sudo.h $(srcdir)/sudo_plugin_int.h $(top_builddir)/config.h \
         $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 hooks.plog: hooks.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/hooks.c --i-file $< --output-file $@
 limits.o: $(srcdir)/limits.c $(incdir)/compat/stdbool.h \
          $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h \
-          $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
-          $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
-          $(top_builddir)/config.h $(top_builddir)/pathnames.h
+          $(incdir)/sudo_event.h $(incdir)/sudo_fatal.h \
+          $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
+          $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
+          $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/limits.c
 limits.i: $(srcdir)/limits.c $(incdir)/compat/stdbool.h \
          $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h \
-          $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
-          $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
-          $(top_builddir)/config.h $(top_builddir)/pathnames.h
+          $(incdir)/sudo_event.h $(incdir)/sudo_fatal.h \
+          $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
+          $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
+          $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 limits.plog: limits.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/limits.c --i-file $< --output-file $@
 load_plugins.o: $(srcdir)/load_plugins.c $(incdir)/compat/stdbool.h \
                $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
                $(incdir)/sudo_debug.h $(incdir)/sudo_dso.h \
-                $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
-                $(incdir)/sudo_plugin.h $(incdir)/sudo_queue.h \
-                $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+                $(incdir)/sudo_event.h $(incdir)/sudo_fatal.h \
+                $(incdir)/sudo_gettext.h $(incdir)/sudo_plugin.h \
+                $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
                $(srcdir)/sudo_plugin_int.h $(top_builddir)/config.h \
                $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/load_plugins.c
 load_plugins.i: $(srcdir)/load_plugins.c $(incdir)/compat/stdbool.h \
                $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
                $(incdir)/sudo_debug.h $(incdir)/sudo_dso.h \
-                $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
-                $(incdir)/sudo_plugin.h $(incdir)/sudo_queue.h \
-                $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+                $(incdir)/sudo_event.h $(incdir)/sudo_fatal.h \
+                $(incdir)/sudo_gettext.h $(incdir)/sudo_plugin.h \
+                $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
                $(srcdir)/sudo_plugin_int.h $(top_builddir)/config.h \
                $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
@@ -526,35 +532,37 @@ net_ifs.plog: net_ifs.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/net_ifs.c --i-file $< --output-file $@
 openbsd.o: $(srcdir)/openbsd.c $(incdir)/compat/stdbool.h \
           $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-           $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-           $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-           $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
-           $(top_builddir)/pathnames.h
+           $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+           $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+           $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+           $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/openbsd.c
 openbsd.i: $(srcdir)/openbsd.c $(incdir)/compat/stdbool.h \
           $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-           $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-           $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-           $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
-           $(top_builddir)/pathnames.h
+           $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+           $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+           $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+           $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 openbsd.plog: openbsd.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/openbsd.c --i-file $< --output-file $@
 parse_args.o: $(srcdir)/parse_args.c $(incdir)/compat/getopt.h \
              $(incdir)/compat/stdbool.h $(incdir)/sudo_compat.h \
              $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h \
-              $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
-              $(incdir)/sudo_lbuf.h $(incdir)/sudo_queue.h \
-              $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
-              $(top_builddir)/pathnames.h ./sudo_usage.h
+              $(incdir)/sudo_event.h $(incdir)/sudo_fatal.h \
+              $(incdir)/sudo_gettext.h $(incdir)/sudo_lbuf.h \
+              $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+              $(top_builddir)/config.h $(top_builddir)/pathnames.h \
+              ./sudo_usage.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/parse_args.c
 parse_args.i: $(srcdir)/parse_args.c $(incdir)/compat/getopt.h \
              $(incdir)/compat/stdbool.h $(incdir)/sudo_compat.h \
              $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h \
-              $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
-              $(incdir)/sudo_lbuf.h $(incdir)/sudo_queue.h \
-              $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
-              $(top_builddir)/pathnames.h ./sudo_usage.h
+              $(incdir)/sudo_event.h $(incdir)/sudo_fatal.h \
+              $(incdir)/sudo_gettext.h $(incdir)/sudo_lbuf.h \
+              $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+              $(top_builddir)/config.h $(top_builddir)/pathnames.h \
+              ./sudo_usage.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 parse_args.plog: parse_args.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/parse_args.c --i-file $< --output-file $@
@@ -568,33 +576,35 @@ preload.plog: preload.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/preload.c --i-file $< --output-file $@
 preserve_fds.o: $(srcdir)/preserve_fds.c $(incdir)/compat/stdbool.h \
                $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-                $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-                $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-                $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+                $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+                $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+                $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
                $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/preserve_fds.c
 preserve_fds.i: $(srcdir)/preserve_fds.c $(incdir)/compat/stdbool.h \
                $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-                $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-                $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-                $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+                $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+                $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+                $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
                $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 preserve_fds.plog: preserve_fds.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/preserve_fds.c --i-file $< --output-file $@
 selinux.o: $(srcdir)/selinux.c $(incdir)/compat/stdbool.h \
           $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-           $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-           $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-           $(incdir)/sudo_util.h $(srcdir)/sudo.h $(srcdir)/sudo_exec.h \
-           $(top_builddir)/config.h $(top_builddir)/pathnames.h
+           $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+           $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+           $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+           $(srcdir)/sudo_exec.h $(top_builddir)/config.h \
+           $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/selinux.c
 selinux.i: $(srcdir)/selinux.c $(incdir)/compat/stdbool.h \
           $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-           $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-           $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-           $(incdir)/sudo_util.h $(srcdir)/sudo.h $(srcdir)/sudo_exec.h \
-           $(top_builddir)/config.h $(top_builddir)/pathnames.h
+           $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+           $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+           $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+           $(srcdir)/sudo_exec.h $(top_builddir)/config.h \
+           $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 selinux.plog: selinux.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/selinux.c --i-file $< --output-file $@
@@ -614,127 +624,133 @@ sesh.plog: sesh.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/sesh.c --i-file $< --output-file $@
 signal.o: $(srcdir)/signal.c $(incdir)/compat/stdbool.h \
          $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h \
-          $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
-          $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
-          $(srcdir)/sudo_exec.h $(top_builddir)/config.h \
-          $(top_builddir)/pathnames.h
+          $(incdir)/sudo_event.h $(incdir)/sudo_fatal.h \
+          $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
+          $(incdir)/sudo_util.h $(srcdir)/sudo.h $(srcdir)/sudo_exec.h \
+          $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/signal.c
 signal.i: $(srcdir)/signal.c $(incdir)/compat/stdbool.h \
          $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h \
-          $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
-          $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
-          $(srcdir)/sudo_exec.h $(top_builddir)/config.h \
-          $(top_builddir)/pathnames.h
+          $(incdir)/sudo_event.h $(incdir)/sudo_fatal.h \
+          $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
+          $(incdir)/sudo_util.h $(srcdir)/sudo.h $(srcdir)/sudo_exec.h \
+          $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 signal.plog: signal.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/signal.c --i-file $< --output-file $@
 solaris.o: $(srcdir)/solaris.c $(incdir)/compat/stdbool.h \
           $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-           $(incdir)/sudo_debug.h $(incdir)/sudo_dso.h $(incdir)/sudo_fatal.h \
-           $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-           $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
-           $(top_builddir)/pathnames.h
+           $(incdir)/sudo_debug.h $(incdir)/sudo_dso.h $(incdir)/sudo_event.h \
+           $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+           $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+           $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/solaris.c
 solaris.i: $(srcdir)/solaris.c $(incdir)/compat/stdbool.h \
           $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-           $(incdir)/sudo_debug.h $(incdir)/sudo_dso.h $(incdir)/sudo_fatal.h \
-           $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-           $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
-           $(top_builddir)/pathnames.h
+           $(incdir)/sudo_debug.h $(incdir)/sudo_dso.h $(incdir)/sudo_event.h \
+           $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+           $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+           $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 solaris.plog: solaris.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/solaris.c --i-file $< --output-file $@
 sudo.o: $(srcdir)/sudo.c $(incdir)/compat/stdbool.h $(incdir)/sudo_compat.h \
-        $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-        $(incdir)/sudo_gettext.h $(incdir)/sudo_plugin.h \
-        $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
-        $(srcdir)/sudo_plugin_int.h $(top_builddir)/config.h \
+        $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+        $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+        $(incdir)/sudo_plugin.h $(incdir)/sudo_queue.h $(incdir)/sudo_util.h \
+        $(srcdir)/sudo.h $(srcdir)/sudo_plugin_int.h $(top_builddir)/config.h \
        $(top_builddir)/pathnames.h ./sudo_usage.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/sudo.c
 sudo.i: $(srcdir)/sudo.c $(incdir)/compat/stdbool.h $(incdir)/sudo_compat.h \
-        $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-        $(incdir)/sudo_gettext.h $(incdir)/sudo_plugin.h \
-        $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
-        $(srcdir)/sudo_plugin_int.h $(top_builddir)/config.h \
+        $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+        $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+        $(incdir)/sudo_plugin.h $(incdir)/sudo_queue.h $(incdir)/sudo_util.h \
+        $(srcdir)/sudo.h $(srcdir)/sudo_plugin_int.h $(top_builddir)/config.h \
        $(top_builddir)/pathnames.h ./sudo_usage.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 sudo.plog: sudo.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/sudo.c --i-file $< --output-file $@
 sudo_edit.o: $(srcdir)/sudo_edit.c $(incdir)/compat/stdbool.h \
             $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-             $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-             $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-             $(incdir)/sudo_util.h $(srcdir)/sudo.h $(srcdir)/sudo_exec.h \
-             $(top_builddir)/config.h $(top_builddir)/pathnames.h
+             $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+             $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+             $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+             $(srcdir)/sudo_exec.h $(top_builddir)/config.h \
+             $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/sudo_edit.c
 sudo_edit.i: $(srcdir)/sudo_edit.c $(incdir)/compat/stdbool.h \
             $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-             $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-             $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-             $(incdir)/sudo_util.h $(srcdir)/sudo.h $(srcdir)/sudo_exec.h \
-             $(top_builddir)/config.h $(top_builddir)/pathnames.h
+             $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+             $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+             $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+             $(srcdir)/sudo_exec.h $(top_builddir)/config.h \
+             $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 sudo_edit.plog: sudo_edit.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/sudo_edit.c --i-file $< --output-file $@
 tcsetpgrp_nobg.o: $(srcdir)/tcsetpgrp_nobg.c $(incdir)/compat/stdbool.h \
                  $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-                  $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-                  $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-                  $(incdir)/sudo_util.h $(srcdir)/sudo.h \
-                  $(top_builddir)/config.h $(top_builddir)/pathnames.h
+                  $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+                  $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+                  $(incdir)/sudo_queue.h $(incdir)/sudo_util.h \
+                  $(srcdir)/sudo.h $(top_builddir)/config.h \
+                  $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/tcsetpgrp_nobg.c
 tcsetpgrp_nobg.i: $(srcdir)/tcsetpgrp_nobg.c $(incdir)/compat/stdbool.h \
                  $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-                  $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-                  $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-                  $(incdir)/sudo_util.h $(srcdir)/sudo.h \
-                  $(top_builddir)/config.h $(top_builddir)/pathnames.h
+                  $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+                  $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+                  $(incdir)/sudo_queue.h $(incdir)/sudo_util.h \
+                  $(srcdir)/sudo.h $(top_builddir)/config.h \
+                  $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 tcsetpgrp_nobg.plog: tcsetpgrp_nobg.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/tcsetpgrp_nobg.c --i-file $< --output-file $@
 tgetpass.o: $(srcdir)/tgetpass.c $(incdir)/compat/stdbool.h \
            $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-            $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-            $(incdir)/sudo_gettext.h $(incdir)/sudo_plugin.h \
-            $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
-            $(top_builddir)/config.h $(top_builddir)/pathnames.h
+            $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+            $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+            $(incdir)/sudo_plugin.h $(incdir)/sudo_queue.h \
+            $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
+            $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/tgetpass.c
 tgetpass.i: $(srcdir)/tgetpass.c $(incdir)/compat/stdbool.h \
            $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-            $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-            $(incdir)/sudo_gettext.h $(incdir)/sudo_plugin.h \
-            $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
-            $(top_builddir)/config.h $(top_builddir)/pathnames.h
+            $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+            $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+            $(incdir)/sudo_plugin.h $(incdir)/sudo_queue.h \
+            $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
+            $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 tgetpass.plog: tgetpass.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/tgetpass.c --i-file $< --output-file $@
 ttyname.o: $(srcdir)/ttyname.c $(incdir)/compat/stdbool.h \
           $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-           $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-           $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-           $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
-           $(top_builddir)/pathnames.h
+           $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+           $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+           $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+           $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/ttyname.c
 ttyname.i: $(srcdir)/ttyname.c $(incdir)/compat/stdbool.h \
           $(incdir)/sudo_compat.h $(incdir)/sudo_conf.h \
-           $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-           $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
-           $(incdir)/sudo_util.h $(srcdir)/sudo.h $(top_builddir)/config.h \
-           $(top_builddir)/pathnames.h
+           $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+           $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h \
+           $(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/sudo.h \
+           $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 ttyname.plog: ttyname.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/ttyname.c --i-file $< --output-file $@
 utmp.o: $(srcdir)/utmp.c $(incdir)/compat/stdbool.h $(incdir)/sudo_compat.h \
-        $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-        $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h $(incdir)/sudo_util.h \
-        $(srcdir)/sudo.h $(srcdir)/sudo_exec.h $(top_builddir)/config.h \
-        $(top_builddir)/pathnames.h
+        $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+        $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
+        $(incdir)/sudo_util.h $(srcdir)/sudo.h $(srcdir)/sudo_exec.h \
+        $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/utmp.c
 utmp.i: $(srcdir)/utmp.c $(incdir)/compat/stdbool.h $(incdir)/sudo_compat.h \
-        $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h $(incdir)/sudo_fatal.h \
-        $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h $(incdir)/sudo_util.h \
-        $(srcdir)/sudo.h $(srcdir)/sudo_exec.h $(top_builddir)/config.h \
-        $(top_builddir)/pathnames.h
+        $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h $(incdir)/sudo_event.h \
+        $(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h $(incdir)/sudo_queue.h \
+        $(incdir)/sudo_util.h $(srcdir)/sudo.h $(srcdir)/sudo_exec.h \
+        $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(CC) -E -o $@ $(CPPFLAGS) $<
 utmp.plog: utmp.i
 	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/utmp.c --i-file $< --output-file $@
--- a/src/exec.c
+++ b/src/exec.c
@@ -52,7 +52,6 @@

 #include "sudo.h"
 #include "sudo_exec.h"
-#include "sudo_event.h"
 #include "sudo_plugin.h"
 #include "sudo_plugin_int.h"

@@ -314,7 +313,7 @@ sudo_terminated(struct command_status *cstat)
    debug_return_bool(false);
 }

-#if SUDO_API_VERSION != SUDO_API_MKVERSION(1, 14)
+#if SUDO_API_VERSION != SUDO_API_MKVERSION(1, 15)
 # error "Update sudo_needs_pty() after changing the plugin API"
 #endif
 static bool
--- a/src/exec_monitor.c
+++ b/src/exec_monitor.c
@@ -43,7 +43,6 @@
 #include <termios.h>

 #include "sudo.h"
-#include "sudo_event.h"
 #include "sudo_exec.h"
 #include "sudo_plugin.h"
 #include "sudo_plugin_int.h"
--- a/src/exec_nopty.c
+++ b/src/exec_nopty.c
@@ -40,7 +40,6 @@

 #include "sudo.h"
 #include "sudo_exec.h"
-#include "sudo_event.h"
 #include "sudo_plugin.h"
 #include "sudo_plugin_int.h"

@@ -209,9 +208,8 @@ fill_exec_closure_nopty(struct exec_closure_nopty *ec,
    ec->details = details;

    /* Setup event base and events. */
-    ec->evbase = sudo_ev_base_alloc();
-    if (ec->evbase == NULL)
-	sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+    ec->evbase = details->evbase;
+    details->evbase = NULL;

    /* Event for command status via errfd. */
    ec->errpipe_event = sudo_ev_alloc(errfd,
--- a/src/exec_pty.c
+++ b/src/exec_pty.c
@@ -43,7 +43,6 @@
 #include <termios.h>		/* for struct winsize on HP-UX */

 #include "sudo.h"
-#include "sudo_event.h"
 #include "sudo_exec.h"
 #include "sudo_plugin.h"
 #include "sudo_plugin_int.h"
@@ -1160,9 +1159,8 @@ fill_exec_closure_pty(struct exec_closure_pty *ec, struct command_status *cstat,
    TAILQ_INIT(&ec->monitor_messages);

    /* Setup event base and events. */
-    ec->evbase = sudo_ev_base_alloc();
-    if (ec->evbase == NULL)
-	sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+    ec->evbase = details->evbase;
+    details->evbase = NULL;

    /* Event for command status via backchannel. */
    ec->backchannel_event = sudo_ev_alloc(backchannel,
--- a/src/load_plugins.c
+++ b/src/load_plugins.c
@@ -368,6 +368,15 @@ sudo_load_plugins(struct plugin_container *policy_plugin,
 		container->u.io->register_hooks(SUDO_HOOK_VERSION, register_hook);
 	}
    }
+
+    /* Set event_alloc() in plugins. */
+    if (policy_plugin->u.policy->version >= SUDO_API_MKVERSION(1, 15))
+	policy_plugin->u.policy->event_alloc = sudo_plugin_event_alloc;
+    TAILQ_FOREACH(container, io_plugins, entries) {
+	if (container->u.io->version >= SUDO_API_MKVERSION(1, 15))
+	    container->u.io->event_alloc = sudo_plugin_event_alloc;
+    }
+
    sudo_debug_set_active_instance(sudo_debug_instance);

 done:
--- a/src/sudo.c
+++ b/src/sudo.c
@@ -31,6 +31,7 @@
 #include <sys/stat.h>
 #include <sys/wait.h>
 #include <sys/socket.h>
+#include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
 #ifdef HAVE_STRING_H
@@ -79,6 +80,7 @@ const char *list_user; /* extern for parse_args.c */
 int sudo_debug_instance = SUDO_DEBUG_INSTANCE_INITIALIZER;
 static struct command_details command_details;
 static int sudo_mode;
+static struct sudo_event_base *sudo_event_base;

 struct sudo_gc_entry {
    SLIST_ENTRY(sudo_gc_entry) entries;
@@ -213,6 +215,10 @@ main(int argc, char *argv[], char *envp[])
    if (!sudo_load_plugins(&policy_plugin, &io_plugins))
 	sudo_fatalx(U_("fatal error, unable to load plugins"));

+    /* Allocate event base so plugin can use it. */
+    if ((sudo_event_base = sudo_ev_base_alloc()) == NULL)
+	sudo_fatalx("%s", U_("unable to allocate memory"));
+
    /* Open policy plugin. */
    ok = policy_open(&policy_plugin, settings, user_info, envp);
    if (ok != 1) {
@@ -288,6 +294,7 @@ main(int argc, char *argv[], char *envp[])
 	    command_details.tty = user_details.tty;
 	    command_details.argv = argv_out;
 	    command_details.envp = user_env_out;
+	    command_details.evbase = sudo_event_base;
 	    if (ISSET(sudo_mode, MODE_LOGIN_SHELL))
 		SET(command_details.flags, CD_LOGIN_SHELL);
 	    if (ISSET(sudo_mode, MODE_BACKGROUND))
@@ -1328,6 +1335,158 @@ iolog_unlink(struct plugin_container *plugin)
    debug_return;
 }

+/*
+ * Fill in a previously allocated struct sudo_plugin_event.
+ */
+static int
+plugin_event_set(struct sudo_plugin_event *pev, int fd, int events,
+    sudo_ev_callback_t callback, void *closure)
+{
+    struct sudo_plugin_event_int *ev_int;
+    debug_decl(plugin_event_set, SUDO_DEBUG_PCOMM)
+
+    ev_int = __containerof(pev, struct sudo_plugin_event_int, public);
+    if (sudo_ev_set(&ev_int->private, fd, events, callback, closure) == -1)
+	debug_return_int(-1);
+
+    /* Plugin can only operate on the main event loop. */
+    ev_int->private.base = sudo_event_base;
+
+    debug_return_int(1);
+}
+
+/*
+ * Add a struct sudo_plugin_event to the main event loop.
+ */
+static int
+plugin_event_add(struct sudo_plugin_event *pev, struct timespec *timo)
+{
+    struct sudo_plugin_event_int *ev_int;
+    debug_decl(plugin_event_add, SUDO_DEBUG_PCOMM)
+
+    ev_int = __containerof(pev, struct sudo_plugin_event_int, public);
+    if (sudo_ev_add(NULL, &ev_int->private, timo, 0) == -1)
+	debug_return_int(-1);
+    debug_return_int(1);
+}
+
+/*
+ * Delete a struct sudo_plugin_event from the main event loop.
+ */
+static int
+plugin_event_del(struct sudo_plugin_event *pev)
+{
+    struct sudo_plugin_event_int *ev_int;
+    debug_decl(plugin_event_del, SUDO_DEBUG_PCOMM)
+
+    ev_int = __containerof(pev, struct sudo_plugin_event_int, public);
+    if (sudo_ev_del(NULL, &ev_int->private) == -1)
+	debug_return_int(-1);
+    debug_return_int(1);
+}
+
+/*
+ * Get the amount of time remaining in a timeout event.
+ */
+static int
+plugin_event_timeleft(struct sudo_plugin_event *pev, struct timespec *ts)
+{
+    struct sudo_plugin_event_int *ev_int;
+    debug_decl(plugin_event_timeleft, SUDO_DEBUG_PCOMM)
+
+    ev_int = __containerof(pev, struct sudo_plugin_event_int, public);
+    if (sudo_ev_get_timeleft(&ev_int->private, ts) == -1)
+	debug_return_int(-1);
+    debug_return_int(1);
+}
+
+/*
+ * Get the file descriptor associated with an event.
+ */
+static int
+plugin_event_fd(struct sudo_plugin_event *pev)
+{
+    struct sudo_plugin_event_int *ev_int;
+    debug_decl(plugin_event_fd, SUDO_DEBUG_PCOMM)
+
+    ev_int = __containerof(pev, struct sudo_plugin_event_int, public);
+    debug_return_int(sudo_ev_get_fd(&ev_int->private));
+}
+
+/*
+ * Break out of the event loop, killing the command if it is running.
+ */
+static void
+plugin_event_loopbreak(struct sudo_plugin_event *pev)
+{
+    struct sudo_plugin_event_int *ev_int;
+    debug_decl(plugin_event_loopbreak, SUDO_DEBUG_PCOMM)
+
+    ev_int = __containerof(pev, struct sudo_plugin_event_int, public);
+    sudo_ev_loopbreak(ev_int->private.base);
+    debug_return;
+}
+
+/*
+ * Reset the event base of a struct sudo_plugin_event.
+ * The event is removed from the old base (if any) first.
+ */
+static void
+plugin_event_setbase(struct sudo_plugin_event *pev, void *base)
+{
+    struct sudo_plugin_event_int *ev_int;
+    debug_decl(plugin_event_setbase, SUDO_DEBUG_PCOMM)
+
+    ev_int = __containerof(pev, struct sudo_plugin_event_int, public);
+    if (ev_int->private.base != NULL)
+	sudo_ev_del(ev_int->private.base, &ev_int->private);
+    ev_int->private.base = base;
+    debug_return;
+}
+
+/*
+ * Free a struct sudo_plugin_event allocated by plugin_event_alloc().
+ */
+static void
+plugin_event_free(struct sudo_plugin_event *pev)
+{
+    struct sudo_plugin_event_int *ev_int;
+    debug_decl(plugin_event_free, SUDO_DEBUG_PCOMM)
+
+    /* The private field is first so sudo_ev_free() can free the struct. */
+    ev_int = __containerof(pev, struct sudo_plugin_event_int, public);
+    sudo_ev_free(&ev_int->private);
+
+    debug_return;
+}
+
+/*
+ * Allocate a struct sudo_plugin_event and fill in the public fields.
+ */
+struct sudo_plugin_event *
+sudo_plugin_event_alloc(void)
+{
+    struct sudo_plugin_event_int *ev_int;
+    debug_decl(plugin_event_alloc, SUDO_DEBUG_PCOMM)
+
+    if ((ev_int = malloc(sizeof(*ev_int))) == NULL)
+	debug_return_ptr(NULL);
+
+    /* Init public fields. */
+    ev_int->public.set = plugin_event_set;
+    ev_int->public.add = plugin_event_add;
+    ev_int->public.del = plugin_event_del;
+    ev_int->public.fd = plugin_event_fd;
+    ev_int->public.timeleft = plugin_event_timeleft;
+    ev_int->public.setbase = plugin_event_setbase;
+    ev_int->public.free = plugin_event_free;
+
+    /* Clear private portion in case caller tries to use us uninitialized. */
+    memset(&ev_int->private, 0, sizeof(ev_int->private));
+
+    debug_return_ptr(&ev_int->public);
+}
+
 static void
 free_plugin_container(struct plugin_container *plugin, bool ioplugin)
 {
--- a/src/sudo.h
+++ b/src/sudo.h
@@ -39,6 +39,7 @@
 #include "sudo_conf.h"
 #include "sudo_debug.h"
 #include "sudo_queue.h"
+#include "sudo_event.h"
 #include "sudo_util.h"

 #ifdef HAVE_PRIV_SET
@@ -169,6 +170,7 @@ struct command_details {
    const char *tty;
    char **argv;
    char **envp;
+    struct sudo_event_base *evbase;
 #ifdef HAVE_PRIV_SET
    priv_set_t *privs;
    priv_set_t *limitprivs;
@@ -218,6 +220,7 @@ int run_command(struct command_details *details);
 int os_init_common(int argc, char *argv[], char *envp[]);
 bool gc_add(enum sudo_gc_types type, void *v);
 bool set_user_groups(struct command_details *details);
+struct sudo_plugin_event *sudo_plugin_event_alloc(void);
 extern const char *list_user;
 extern struct user_details user_details;
 extern int sudo_debug_instance;
--- a/src/sudo_plugin_int.h
+++ b/src/sudo_plugin_int.h
@@ -104,6 +104,14 @@ struct plugin_container {
 };
 TAILQ_HEAD(plugin_container_list, plugin_container);

+/*
+ * Private implementation of struct sudo_plugin_event.
+ */
+struct sudo_plugin_event_int {
+    struct sudo_event private;		/* must be first */
+    struct sudo_plugin_event public;
+};
+
 extern struct plugin_container policy_plugin;
 extern struct plugin_container_list io_plugins;