Adding upstream version 1.9.15p5.upstream/1.9.15p5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 762 insertions, 0 deletions

diff --git a/plugins/sample/Makefile.in b/plugins/sample/Makefile.in
new file mode 100644
index 0000000..a20cdd4
--- /dev/null
+++ b/plugins/sample/Makefile.in
@@ -0,0 +1,221 @@
+#
+# SPDX-License-Identifier: ISC
+#
+# Copyright (c) 2011-2023 Todd C. Miller <Todd.Miller@sudo.ws>
+#
+# Permission to use, copy, modify, and distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+#
+# @configure_input@
+#
+
+#### Start of system configuration section. ####
+
+srcdir = @srcdir@
+abs_srcdir = @abs_srcdir@
+top_srcdir = @top_srcdir@
+abs_top_srcdir = @abs_top_srcdir@
+top_builddir = @top_builddir@
+abs_top_builddir = @abs_top_builddir@
+devdir = @devdir@
+scriptdir = $(top_srcdir)/scripts
+incdir = $(top_srcdir)/include
+cross_compiling = @CROSS_COMPILING@
+
+# Compiler & tools to use
+CC = @CC@
+LIBTOOL = @LIBTOOL@
+SED = @SED@
+AWK = @AWK@
+
+# Our install program supports extra flags...
+INSTALL = $(SHELL) $(scriptdir)/install-sh -c
+INSTALL_OWNER = -o $(install_uid) -g $(install_gid)
+INSTALL_BACKUP = @INSTALL_BACKUP@
+
+# Libraries
+LIBS = $(top_builddir)/lib/util/libsudo_util.la
+
+# C preprocessor flags
+CPPFLAGS = -I$(incdir) -I$(top_builddir) @CPPFLAGS@
+
+# Usually -O and/or -g
+CFLAGS = @CFLAGS@
+
+# Flags to pass to the link stage
+LDFLAGS = @LDFLAGS@
+LT_LDFLAGS = @LT_LDFLAGS@ @LT_LDEXPORTS@
+
+# Flags to pass to libtool
+LTFLAGS = --tag=disable-static
+
+# Address sanitizer flags
+ASAN_CFLAGS = @ASAN_CFLAGS@
+ASAN_LDFLAGS = @ASAN_LDFLAGS@
+
+# PIE flags
+PIE_CFLAGS = @PIE_CFLAGS@
+PIE_LDFLAGS = @PIE_LDFLAGS@
+
+# Stack smashing protection flags
+HARDENING_CFLAGS = @HARDENING_CFLAGS@
+HARDENING_LDFLAGS = @HARDENING_LDFLAGS@
+
+# cppcheck options, usually set in the top-level Makefile
+CPPCHECK_OPTS = -q --enable=warning,performance,portability --suppress=constStatement --suppress=compareBoolExpressionWithInt --error-exitcode=1 --inline-suppr -Dva_copy=va_copy -U__cplusplus -UQUAD_MAX -UQUAD_MIN -UUQUAD_MAX -U_POSIX_HOST_NAME_MAX -U_POSIX_PATH_MAX -U__NBBY -DNSIG=64
+
+# splint options, usually set in the top-level Makefile
+SPLINT_OPTS = -D__restrict= -checks
+
+# PVS-studio options
+PVS_CFG = $(top_srcdir)/PVS-Studio.cfg
+PVS_IGNORE = 'V707,V011,V002,V536'
+PVS_LOG_OPTS = -a 'GA:1,2' -e -t errorfile -d $(PVS_IGNORE)
+
+# Where to install things...
+prefix = @prefix@
+exec_prefix = @exec_prefix@
+bindir = @bindir@
+sbindir = @sbindir@
+sysconfdir = @sysconfdir@
+adminconfdir = @adminconfdir@
+libexecdir = @libexecdir@
+datarootdir = @datarootdir@
+localstatedir = @localstatedir@
+plugindir = @plugindir@
+
+# File mode and map file to use for shared libraries/objects
+shlib_enable = @SHLIB_ENABLE@
+shlib_mode = @SHLIB_MODE@
+shlib_exp = $(srcdir)/sample_plugin.exp
+shlib_map = sample_plugin.map
+shlib_opt = sample_plugin.opt
+
+# User and group ids the installed files should be "owned" by
+install_uid = 0
+install_gid = 0
+
+#### End of system configuration section. ####
+
+SHELL = @SHELL@
+
+OBJS =	sample_plugin.lo
+
+LIBOBJDIR = $(top_builddir)/@ac_config_libobj_dir@/
+
+VERSION = @PACKAGE_VERSION@
+
+all: sample_plugin.la
+
+depend:
+	$(scriptdir)/mkdep.pl --srcdir=$(abs_top_srcdir) \
+	    --builddir=$(abs_top_builddir) plugins/sample/Makefile.in
+	cd $(top_builddir) && ./config.status --file plugins/sample/Makefile
+
+Makefile: $(srcdir)/Makefile.in
+	cd $(top_builddir) && ./config.status --file plugins/sample/Makefile
+
+.SUFFIXES: .c .h .i .lo .plog
+
+.c.lo:
+	$(LIBTOOL) $(LTFLAGS) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(HARDENING_CFLAGS) $<
+
+.c.i:
+	$(CC) -E -o $@ $(CPPFLAGS) $<
+
+.i.plog:
+	ifile=$<; rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $${ifile%i}c --i-file $< --output-file $@
+
+$(shlib_map): $(shlib_exp)
+	@$(AWK) 'BEGIN { print "{\n\tglobal:" } { print "\t\t"$$0";" } END { print "\tlocal:\n\t\t*;\n};" }' $(shlib_exp) > $@
+
+$(shlib_opt): $(shlib_exp)
+	@$(SED) 's/^/+e /' $(shlib_exp) > $@
+
+sample_plugin.la: $(OBJS) @LT_LDDEP@
+	$(LIBTOOL) $(LTFLAGS) --mode=link $(CC) $(LDFLAGS) $(ASAN_LDFLAGS) $(HARDENING_LDFLAGS) $(LT_LDFLAGS) -o $@ $(OBJS) $(LIBS) -module -avoid-version -rpath $(plugindir) -shrext .so
+
+pre-install:
+
+install: install-plugin
+
+install-dirs:
+	$(SHELL) $(scriptdir)/mkinstalldirs $(DESTDIR)$(plugindir)
+
+install-binaries:
+
+install-includes:
+
+install-doc:
+
+install-plugin: install-dirs sample_plugin.la
+	if [ X"$(shlib_enable)" = X"yes" ]; then \
+	    INSTALL_BACKUP='$(INSTALL_BACKUP)' $(LIBTOOL) $(LTFLAGS) --mode=install $(INSTALL) $(INSTALL_OWNER) -m $(shlib_mode) sample_plugin.la $(DESTDIR)$(plugindir); \
+	fi
+
+install-fuzzer:
+
+uninstall:
+	-$(LIBTOOL) $(LTFLAGS) --mode=uninstall rm -f $(DESTDIR)$(plugindir)/sample_plugin.la
+	-test -z "$(INSTALL_BACKUP)" || \
+	    rm -f $(DESTDIR)$(plugindir)/sample_plugin.so$(INSTALL_BACKUP)
+
+splint:
+	splint $(SPLINT_OPTS) -I$(incdir) -I$(top_builddir) $(srcdir)/*.c
+
+cppcheck:
+	cppcheck $(CPPCHECK_OPTS) -I$(incdir) -I$(top_builddir) $(srcdir)/*.c
+
+pvs-log-files: $(POBJS)
+
+pvs-studio: $(POBJS)
+	plog-converter $(PVS_LOG_OPTS) $(POBJS)
+
+fuzz:
+
+check-fuzzer:
+
+check: check-fuzzer
+
+check-verbose: check
+
+clean:
+	-$(LIBTOOL) $(LTFLAGS) --mode=clean rm -f *.lo *.o *.la
+	-rm -f *.i *.plog stamp-* core *.core core.*
+
+mostlyclean: clean
+
+distclean: clean
+	-rm -rf Makefile .libs $(shlib_map) $(shlib_opt)
+
+clobber: distclean
+
+realclean: distclean
+	rm -f TAGS tags
+
+cleandir: realclean
+
+.PHONY: clean mostlyclean distclean cleandir clobber realclean
+
+# Autogenerated dependencies, do not modify
+sample_plugin.lo: $(srcdir)/sample_plugin.c $(incdir)/compat/stdbool.h \
+                  $(incdir)/sudo_compat.h $(incdir)/sudo_plugin.h \
+                  $(incdir)/sudo_util.h $(top_builddir)/config.h \
+                  $(top_builddir)/pathnames.h
+	$(LIBTOOL) $(LTFLAGS) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(ASAN_CFLAGS) $(PIE_CFLAGS) $(HARDENING_CFLAGS) $(srcdir)/sample_plugin.c
+sample_plugin.i: $(srcdir)/sample_plugin.c $(incdir)/compat/stdbool.h \
+                  $(incdir)/sudo_compat.h $(incdir)/sudo_plugin.h \
+                  $(incdir)/sudo_util.h $(top_builddir)/config.h \
+                  $(top_builddir)/pathnames.h
+	$(CC) -E -o $@ $(CPPFLAGS) $<
+sample_plugin.plog: sample_plugin.i
+	rm -f $@; pvs-studio --cfg $(PVS_CFG) --sourcetree-root $(top_srcdir) --skip-cl-exe yes --source-file $(srcdir)/sample_plugin.c --i-file $< --output-file $@
diff --git a/plugins/sample/README b/plugins/sample/README
new file mode 100644
index 0000000..dbd92cd
--- /dev/null
+++ b/plugins/sample/README
@@ -0,0 +1,22 @@
+This is a sample sudo policy plugin.  See the sudo_plugin manual for
+information on writing your own plugin.
+
+The sample policy plugin is not installed by default.  It can be installed
+by running "make install" as the superuser from the plugins/sample
+directory.
+
+To actually use the sample plugin, you'll need to modify the
+/etc/sudo.conf file.  Caution: you should not make changes to
+/etc/sudo.conf without also having a root shell open repair things
+in case of an error.  To enable the plugin, first comment out any
+existing policy Plugin line in /etc/sudo.conf, for example:
+
+    Plugin sudoers_policy sudoers.so
+
+Then add a line for the sample plugin:
+
+    Plugin sample_policy sample_plugin.so
+
+You may need to create /etc/sudo.conf if it does not already exist.
+
+Note that you may only have a single policy plugin defined.
diff --git a/plugins/sample/sample_plugin.c b/plugins/sample/sample_plugin.c
new file mode 100644
index 0000000..a529208
--- /dev/null
+++ b/plugins/sample/sample_plugin.c
@@ -0,0 +1,517 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2010-2016, 2022 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef HAVE_STDBOOL_H
+# include <stdbool.h>
+#else
+# include <compat/stdbool.h>
+#endif /* HAVE_STDBOOL_H */
+#include <string.h>
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif /* HAVE_STRINGS_H */
+#include <unistd.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <grp.h>
+#include <pwd.h>
+
+#include <pathnames.h>
+#include <sudo_compat.h>
+#include <sudo_plugin.h>
+#include <sudo_util.h>
+
+/*
+ * Sample plugin module that allows any user who knows the password
+ * ("test") to run any command as root.  Since there is no credential
+ * caching the validate and invalidate functions are NULL.
+ */
+
+static struct plugin_state {
+    char **envp;
+    char * const *settings;
+    char * const *user_info;
+} plugin_state;
+static sudo_conv_t sudo_conv;
+static sudo_printf_t sudo_log;
+static FILE *input, *output;
+static uid_t runas_uid = ROOT_UID;
+static gid_t runas_gid = (gid_t)-1;
+static int use_sudoedit = false;
+
+/*
+ * Plugin policy open function.
+ */
+static int
+policy_open(unsigned int version, sudo_conv_t conversation,
+    sudo_printf_t sudo_plugin_printf, char * const settings[],
+    char * const user_info[], char * const user_env[], char * const args[],
+    const char **errstr)
+{
+    char * const *ui;
+    struct passwd *pw;
+    const char *runas_user = NULL;
+    struct group *gr;
+    const char *runas_group = NULL;
+
+    if (!sudo_conv)
+	sudo_conv = conversation;
+    if (!sudo_log)
+	sudo_log = sudo_plugin_printf;
+
+    if (SUDO_API_VERSION_GET_MAJOR(version) != SUDO_API_VERSION_MAJOR) {
+	sudo_log(SUDO_CONV_ERROR_MSG,
+	    "the sample plugin requires API version %d.x\n",
+	    SUDO_API_VERSION_MAJOR);
+	return -1;
+    }
+
+    /* Only allow commands to be run as root. */
+    for (ui = settings; *ui != NULL; ui++) {
+	if (strncmp(*ui, "runas_user=", sizeof("runas_user=") - 1) == 0) {
+	    runas_user = *ui + sizeof("runas_user=") - 1;
+	}
+	if (strncmp(*ui, "runas_group=", sizeof("runas_group=") - 1) == 0) {
+	    runas_group = *ui + sizeof("runas_group=") - 1;
+	}
+	if (strncmp(*ui, "progname=", sizeof("progname=") - 1) == 0) {
+	    initprogname(*ui + sizeof("progname=") - 1);
+	}
+	/* Check to see if sudo was called as sudoedit or with -e flag. */
+	if (strncmp(*ui, "sudoedit=", sizeof("sudoedit=") - 1) == 0) {
+	    if (strcasecmp(*ui + sizeof("sudoedit=") - 1, "true") == 0)
+		use_sudoedit = true;
+	}
+	/* This plugin doesn't support running sudo with no arguments. */
+	if (strncmp(*ui, "implied_shell=", sizeof("implied_shell=") - 1) == 0) {
+	    if (strcasecmp(*ui + sizeof("implied_shell=") - 1, "true") == 0)
+		return -2; /* usage error */
+	}
+    }
+    if (runas_user != NULL) {
+	if ((pw = getpwnam(runas_user)) == NULL) {
+	    sudo_log(SUDO_CONV_ERROR_MSG, "unknown user %s\n", runas_user);
+	    return 0;
+	}
+	runas_uid = pw->pw_uid;
+    }
+    if (runas_group != NULL) {
+	if ((gr = getgrnam(runas_group)) == NULL) {
+	    sudo_log(SUDO_CONV_ERROR_MSG, "unknown group %s\n", runas_group);
+	    return 0;
+	}
+	runas_gid = gr->gr_gid;
+    }
+
+    /* Plugin state. */
+    plugin_state.envp = (char **)user_env;
+    plugin_state.settings = settings;
+    plugin_state.user_info = user_info;
+
+    return 1;
+}
+
+static char *
+find_in_path(char *command, char **envp)
+{
+    struct stat sb;
+    char *path = NULL;
+    char *path0, **ep, *cp;
+    char pathbuf[PATH_MAX], *qualified = NULL;
+
+    if (strchr(command, '/') != NULL)
+	return command;
+
+    for (ep = plugin_state.envp; *ep != NULL; ep++) {
+	if (strncmp(*ep, "PATH=", 5) == 0) {
+	    path = *ep + 5;
+	    break;
+	}
+    }
+    path = path0 = strdup(path ? path : _PATH_DEFPATH);
+    do {
+	if ((cp = strchr(path, ':')))
+	    *cp = '\0';
+	snprintf(pathbuf, sizeof(pathbuf), "%s/%s", *path ? path : ".",
+	    command);
+	if (stat(pathbuf, &sb) == 0) {
+	    if (S_ISREG(sb.st_mode) && (sb.st_mode & 0000111)) {
+		qualified = pathbuf;
+		break;
+	    }
+	}
+	path = cp + 1;
+    } while (cp != NULL);
+    free(path0);
+    return qualified ? strdup(qualified) : NULL;
+}
+
+static int
+check_passwd(void)
+{
+    struct sudo_conv_message msg;
+    struct sudo_conv_reply repl;
+
+    /* Prompt user for password via conversation function. */
+    memset(&msg, 0, sizeof(msg));
+    msg.msg_type = SUDO_CONV_PROMPT_ECHO_OFF;
+    msg.msg = "Password: ";
+    memset(&repl, 0, sizeof(repl));
+    sudo_conv(1, &msg, &repl, NULL);
+    if (repl.reply == NULL) {
+	sudo_log(SUDO_CONV_ERROR_MSG, "missing password\n");
+	return false;
+    }
+    if (strcmp(repl.reply, "test") != 0) {
+	sudo_log(SUDO_CONV_ERROR_MSG, "incorrect password\n");
+	return false;
+    }
+    return true;
+}
+
+static char **
+build_command_info(const char *command)
+{
+    char **command_info;
+    int i = 0;
+
+    /* Setup command info. */
+    command_info = calloc(32, sizeof(char *));
+    if (command_info == NULL)
+	goto oom;
+    if ((command_info[i] = sudo_new_key_val("command", command)) == NULL)
+	goto oom;
+    i++;
+    if (asprintf(&command_info[i], "runas_euid=%ld", (long)runas_uid) == -1)
+	goto oom;
+    i++;
+    if (asprintf(&command_info[i++], "runas_uid=%ld", (long)runas_uid) == -1)
+	goto oom;
+    i++;
+    if (runas_gid != (gid_t)-1) {
+	if (asprintf(&command_info[i++], "runas_gid=%ld", (long)runas_gid) == -1)
+	    goto oom;
+	i++;
+	if (asprintf(&command_info[i++], "runas_egid=%ld", (long)runas_gid) == -1)
+	    goto oom;
+	i++;
+    }
+#ifdef USE_TIMEOUT
+    if ((command_info[i] = strdup("timeout=30")) == NULL)
+	goto oom;
+    i++;
+#endif
+    if (use_sudoedit) {
+	if ((command_info[i] = strdup("sudoedit=true")) == NULL)
+	    goto oom;
+    }
+    return command_info;
+oom:
+    while (i > 0) {
+	free(command_info[i--]);
+    }
+    free(command_info);
+    return NULL;
+}
+
+static char *
+find_editor(int nfiles, char * const files[], char **argv_out[])
+{
+    char *cp, *last, **ep, **nargv, *editor_path;
+    char *editor = NULL;
+    int ac, i, nargc, wasblank;
+
+    /* Lookup EDITOR in user's environment. */
+    for (ep = plugin_state.envp; *ep != NULL; ep++) {
+	if (strncmp(*ep, "EDITOR=", 7) == 0) {
+	    editor = *ep + 7;
+	    break;
+	}
+    }
+    editor = strdup(editor ? editor : _PATH_VI);
+    if (editor == NULL) {
+	sudo_log(SUDO_CONV_ERROR_MSG, "unable to allocate memory\n");
+	return NULL;
+    }
+
+    /*
+     * Split editor into an argument vector; editor is reused (do not free).
+     * The EDITOR environment variables may contain command
+     * line args so look for those and alloc space for them too.
+     */
+    nargc = 1;
+    for (wasblank = 0, cp = editor; *cp != '\0'; cp++) {
+	if (isblank((unsigned char) *cp))
+	    wasblank = 1;
+	else if (wasblank) {
+	    wasblank = 0;
+	    nargc++;
+	}
+    }
+    /* If we can't find the editor in the user's PATH, give up. */
+    cp = strtok_r(editor, " \t", &last);
+    if (cp == NULL ||
+	(editor_path = find_in_path(editor, plugin_state.envp)) == NULL) {
+	free(editor);
+	return NULL;
+    }
+    if (editor_path != editor)
+	free(editor);
+    nargv = reallocarray(NULL, (size_t)nargc + 1 + (size_t)nfiles + 1,
+	sizeof(char *));
+    if (nargv == NULL) {
+	sudo_log(SUDO_CONV_ERROR_MSG, "unable to allocate memory\n");
+	free(editor_path);
+	return NULL;
+    }
+    for (ac = 0; cp != NULL && ac < nargc; ac++) {
+	nargv[ac] = cp;
+	cp = strtok_r(NULL, " \t", &last);
+    }
+    nargv[ac++] = (char *)"--";
+    for (i = 0; i < nfiles; )
+	nargv[ac++] = files[i++];
+    nargv[ac] = NULL;
+
+    *argv_out = nargv;
+    return editor_path;
+}
+
+/*
+ * Plugin policy check function.
+ * Simple example that prompts for a password, hard-coded to "test".
+ */
+static int 
+policy_check(int argc, char * const argv[],
+    char *env_add[], char **command_info_out[],
+    char **argv_out[], char **user_env_out[], const char **errstr)
+{
+    char *command;
+
+    if (!argc || argv[0] == NULL) {
+	sudo_log(SUDO_CONV_ERROR_MSG, "no command specified\n");
+	return false;
+    }
+
+    if (!check_passwd())
+	return false;
+
+    command = find_in_path(argv[0], plugin_state.envp);
+    if (command == NULL) {
+	sudo_log(SUDO_CONV_ERROR_MSG, "%s: command not found\n", argv[0]);
+	return false;
+    }
+
+    /* If "sudo vi" is run, auto-convert to sudoedit.  */
+    if (strcmp(command, _PATH_VI) == 0)
+	use_sudoedit = true;
+
+    if (use_sudoedit) {
+	/* Rebuild argv using editor */
+	free(command);
+	command = find_editor(argc - 1, argv + 1, argv_out);
+	if (command == NULL) {
+	    sudo_log(SUDO_CONV_ERROR_MSG, "unable to find valid editor\n");
+	    return -1;
+	}
+	use_sudoedit = true;
+    } else {
+	/* No changes needd to argv */
+	*argv_out = (char **)argv;
+    }
+
+    /* No changes to envp */
+    *user_env_out = plugin_state.envp;
+
+    /* Setup command info. */
+    *command_info_out = build_command_info(command);
+    free(command);
+    if (*command_info_out == NULL) {
+	sudo_log(SUDO_CONV_ERROR_MSG, "out of memory\n");
+	return -1;
+    }
+
+    return true;
+}
+
+static int
+policy_list(int argc, char * const argv[], int verbose, const char *list_user,
+    const char **errstr)
+{
+    /*
+     * List user's capabilities.
+     */
+    sudo_log(SUDO_CONV_INFO_MSG, "Validated users may run any command\n");
+    return true;
+}
+
+static int
+policy_version(int verbose)
+{
+    sudo_log(SUDO_CONV_INFO_MSG, "Sample policy plugin version %s\n",
+	PACKAGE_VERSION);
+    return true;
+}
+
+static void
+policy_close(int exit_status, int error)
+{
+    /*
+     * The policy might log the command exit status here.
+     * In this example, we just print a message.
+     */
+    if (error) {
+	sudo_log(SUDO_CONV_ERROR_MSG, "Command error: %s\n", strerror(error));
+    } else {
+        if (WIFEXITED(exit_status)) {
+	    sudo_log(SUDO_CONV_INFO_MSG, "Command exited with status %d\n",
+		WEXITSTATUS(exit_status));
+        } else if (WIFSIGNALED(exit_status)) {
+	    sudo_log(SUDO_CONV_INFO_MSG, "Command killed by signal %d\n",
+		WTERMSIG(exit_status));
+	}
+    }
+}
+
+static int
+io_open(unsigned int version, sudo_conv_t conversation,
+    sudo_printf_t sudo_plugin_printf, char * const settings[],
+    char * const user_info[], char * const command_info[],
+    int argc, char * const argv[], char * const user_env[], char * const args[],
+    const char **errstr)
+{
+    int fd;
+    char path[PATH_MAX];
+
+    if (!sudo_conv)
+	sudo_conv = conversation;
+    if (!sudo_log)
+	sudo_log = sudo_plugin_printf;
+
+    /* Open input and output files. */
+    snprintf(path, sizeof(path), "/var/tmp/sample-%u.output",
+	(unsigned int)getpid());
+    fd = open(path, O_WRONLY|O_CREAT|O_EXCL, 0644);
+    if (fd == -1)
+	return false;
+    output = fdopen(fd, "w");
+
+    snprintf(path, sizeof(path), "/var/tmp/sample-%u.input",
+	(unsigned int)getpid());
+    fd = open(path, O_WRONLY|O_CREAT|O_EXCL, 0644);
+    if (fd == -1)
+	return false;
+    input = fdopen(fd, "w");
+
+    return true;
+}
+
+static void
+io_close(int exit_status, int error)
+{
+    fclose(input);
+    fclose(output);
+}
+
+static int
+io_version(int verbose)
+{
+    sudo_log(SUDO_CONV_INFO_MSG, "Sample I/O plugin version %s\n",
+	PACKAGE_VERSION);
+    return true;
+}
+
+static int
+io_log_input(const char *buf, unsigned int len, const char **errstr)
+{
+    ignore_result(fwrite(buf, len, 1, input));
+    return true;
+}
+
+static int
+io_log_output(const char *buf, unsigned int len, const char **errstr)
+{
+    const char *cp, *ep;
+    bool ret = true;
+
+    ignore_result(fwrite(buf, len, 1, output));
+    /*
+     * If we find the string "honk!" in the buffer, reject it.
+     * In practice we'd want to be able to detect the word
+     * broken across two buffers.
+     */
+    for (cp = buf, ep = buf + len; cp < ep; cp++) {
+	if (cp + 5 < ep && memcmp(cp, "honk!", 5) == 0) {
+	    ret = false;
+	    break;
+	}
+    }
+    return ret;
+}
+
+sudo_dso_public struct policy_plugin sample_policy = {
+    SUDO_POLICY_PLUGIN,
+    SUDO_API_VERSION,
+    policy_open,
+    policy_close,
+    policy_version,
+    policy_check,
+    policy_list,
+    NULL, /* validate */
+    NULL, /* invalidate */
+    NULL, /* init_session */
+    NULL, /* register_hooks */
+    NULL, /* deregister_hooks */
+    NULL /* event_alloc() filled in by sudo */
+};
+
+/*
+ * Note: This plugin does not differentiate between tty and pipe I/O.
+ *       It all gets logged to the same file.
+ */
+sudo_dso_public struct io_plugin sample_io = {
+    SUDO_IO_PLUGIN,
+    SUDO_API_VERSION,
+    io_open,
+    io_close,
+    io_version,
+    io_log_input,	/* tty input */
+    io_log_output,	/* tty output */
+    io_log_input,	/* command stdin if not tty */
+    io_log_output,	/* command stdout if not tty */
+    io_log_output,	/* command stderr if not tty */
+    NULL, /* register_hooks */
+    NULL, /* deregister_hooks */
+    NULL, /* change_winsize */
+    NULL, /* log_suspend */
+    NULL /* event_alloc() filled in by sudo */
+};
diff --git a/plugins/sample/sample_plugin.exp b/plugins/sample/sample_plugin.exp
new file mode 100644
index 0000000..9f85094
--- /dev/null
+++ b/plugins/sample/sample_plugin.exp
@@ -0,0 +1,2 @@
+sample_policy
+sample_io