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129cf8d99229a267c0d274e7cf3d7e10fc8701df
sudo/plugins/sudoers/sudoers.c
Todd C. Miller 129cf8d992 sudoers.h includes sudo_plugin.h for us
2010-08-10 16:36:54 -04:00

1494 lines
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/*
* Copyright (c) 1993-1996, 1998-2010 Todd C. Miller <Todd.Miller@courtesan.com>
*
* 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.
*
* Sponsored in part by the Defense Advanced Research Projects
* Agency (DARPA) and Air Force Research Laboratory, Air Force
* Materiel Command, USAF, under agreement number F39502-99-1-0512.
*
* For a brief history of sudo, please see the HISTORY file included
* with this distribution.
*/
#define _SUDO_MAIN
#ifdef __TANDEM
# include <floss.h>
#endif
#include <config.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
# include <stdlib.h>
# endif
#endif /* STDC_HEADERS */
#ifdef HAVE_STRING_H
# if defined(HAVE_MEMORY_H) && !defined(STDC_HEADERS)
# include <memory.h>
# endif
# include <string.h>
#endif /* HAVE_STRING_H */
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */
#include <pwd.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <grp.h>
#include <time.h>
#ifdef HAVE_SETLOCALE
# include <locale.h>
#endif
#include <netinet/in.h>
#include <netdb.h>
#if defined(HAVE_GETPRPWNAM) && defined(HAVE_SET_AUTH_PARAMETERS)
# ifdef __hpux
# undef MAXINT
# include <hpsecurity.h>
# else
# include <sys/security.h>
# endif /* __hpux */
# include <prot.h>
#endif /* HAVE_GETPRPWNAM && HAVE_SET_AUTH_PARAMETERS */
#ifdef HAVE_LOGIN_CAP_H
# include <login_cap.h>
# ifndef LOGIN_DEFROOTCLASS
# define LOGIN_DEFROOTCLASS "daemon"
# endif
#endif
#ifdef HAVE_PROJECT_H
# include <project.h>
# include <sys/task.h>
#endif
#ifdef HAVE_SELINUX
# include <selinux/selinux.h>
#endif
#ifdef HAVE_MBR_CHECK_MEMBERSHIP
# include <membership.h>
#endif
#include <ctype.h>
#include <setjmp.h>
#include "sudoers.h"
#include "lbuf.h"
#include "interfaces.h"
#include "auth/sudo_auth.h"
/*
* Prototypes
*/
static void init_vars(char * const *);
static int set_cmnd(int);
static void set_loginclass(struct passwd *);
static void set_project(struct passwd *);
static void set_runasgr(char *);
static void set_runaspw(char *);
static int sudoers_policy_version(int verbose);
static struct passwd *get_authpw(void);
static int deserialize_info(char * const settings[], char * const user_info[]);
static char *find_editor(int nfiles, char **files, char ***argv_out);
static void create_admin_success_flag(void);
/* XXX */
extern int runas_ngroups;
extern GETGROUPS_T *runas_groups;
/*
* Globals
*/
char *prev_user;
struct sudo_user sudo_user;
struct passwd *auth_pw, *list_pw;
struct interface *interfaces;
int num_interfaces;
int long_list;
int debug_level;
uid_t timestamp_uid;
extern int errorlineno;
extern int parse_error;
extern char *errorfile;
#ifdef HAVE_LOGIN_CAP_H
login_cap_t *lc;
#endif /* HAVE_LOGIN_CAP_H */
#ifdef HAVE_BSD_AUTH_H
char *login_style;
#endif /* HAVE_BSD_AUTH_H */
sigaction_t saved_sa_int, saved_sa_quit, saved_sa_tstp;
sudo_conv_t sudo_conv;
sudo_printf_t sudo_printf;
int sudo_mode;
static char *runas_user;
static char *runas_group;
static struct sudo_nss_list *snl;
/* XXX - must be extern for audit bits of sudo_auth.c */
int NewArgc;
char **NewArgv;
/* error.c */
extern sigjmp_buf error_jmp;
static int
sudoers_policy_open(unsigned int version, sudo_conv_t conversation,
sudo_printf_t plugin_printf, char * const settings[],
char * const user_info[], char * const envp[])
{
int sources = 0;
sigaction_t sa;
struct sudo_nss *nss;
/* Must be done before we do any password lookups */
#if defined(HAVE_GETPRPWNAM) && defined(HAVE_SET_AUTH_PARAMETERS)
(void) set_auth_parameters(Argc, Argv);
# ifdef HAVE_INITPRIVS
initprivs();
# endif
#endif /* HAVE_GETPRPWNAM && HAVE_SET_AUTH_PARAMETERS */
if (!sudo_conv)
sudo_conv = conversation;
if (!sudo_printf)
sudo_printf = plugin_printf;
if (sigsetjmp(error_jmp, 1)) {
/* called via error(), errorx() or log_error() */
rewind_perms();
return -1;
}
/*
* Signal setup:
* Ignore keyboard-generated signals so the user cannot interrupt
* us at some point and avoid the logging.
* Install handler to wait for children when they exit.
*/
zero_bytes(&sa, sizeof(sa));
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
sa.sa_handler = SIG_IGN;
(void) sigaction(SIGINT, &sa, &saved_sa_int);
(void) sigaction(SIGQUIT, &sa, &saved_sa_quit);
(void) sigaction(SIGTSTP, &sa, &saved_sa_tstp);
sudo_setpwent();
sudo_setgrent();
/* Initialize environment functions (including replacements). */
env_init(envp);
/* Setup defaults data structures. */
init_defaults();
/* Load the list of local ip addresses and netmasks. */
load_interfaces();
/* Parse settings and user_info */
sudo_mode = deserialize_info(settings, user_info);
init_vars(envp); /* XXX - move this later? */
/* Parse nsswitch.conf for sudoers order. */
snl = sudo_read_nss();
set_perms(PERM_INITIAL);
/* Open and parse sudoers, set global defaults */
tq_foreach_fwd(snl, nss) {
if (nss->open(nss) == 0 && nss->parse(nss) == 0) {
sources++;
if (nss->setdefs(nss) != 0)
log_error(NO_STDERR|NO_EXIT, "problem with defaults entries");
}
}
if (sources == 0) {
warningx("no valid sudoers sources found, quitting");
return -1;
}
/* XXX - collect post-sudoers parse settings into a function */
/*
* Initialize external group plugin.
*/
if (def_group_plugin) {
switch (group_plugin_load(def_group_plugin)) {
case -1:
return -1;
case FALSE:
def_group_plugin = NULL;
}
}
/*
* Set runas passwd/group entries based on command line or sudoers.
* Note that if runas_group was specified without runas_user we
* defer setting runas_pw so the match routines know to ignore it.
*/
if (runas_group != NULL) {
set_runasgr(runas_group);
if (runas_user != NULL)
set_runaspw(runas_user);
} else
set_runaspw(runas_user ? runas_user : def_runas_default);
if (!update_defaults(SETDEF_RUNAS))
log_error(NO_STDERR|NO_EXIT, "problem with defaults entries");
if (def_fqdn)
set_fqdn(); /* deferred until after sudoers is parsed */
/* Set login class if applicable. */
set_loginclass(sudo_user.pw);
restore_perms();
return TRUE;
}
static void
sudoers_policy_close(int exit_status, int error_code)
{
/* We do not currently log the exit status. */
if (error_code)
warningx("unable to execute %s: %s", safe_cmnd, strerror(error_code));
/* Close the session we opened in sudoers_policy_init_session(). */
if (ISSET(sudo_mode, MODE_RUN|MODE_EDIT))
(void)auth_end_session();
/* Free remaining references to password and group entries. */
pw_delref(sudo_user.pw);
pw_delref(runas_pw);
if (runas_gr != NULL)
gr_delref(runas_gr);
}
/*
* The init_session function is called before executing the command
* and before uid/gid changes occur.
*/
static int
sudoers_policy_init_session(struct passwd *pwd)
{
return auth_begin_session(pwd);
}
static int
sudoers_policy_main(int argc, char * const argv[], int pwflag, char *env_add[],
char **command_infop[], char **argv_out[], char **user_env_out[])
{
static char *command_info[32]; /* XXX */
char **edit_argv = NULL;
struct sudo_nss *nss;
int cmnd_status = -1, validated;
int info_len = 0;
int rval = FALSE;
/* Is root even allowed to run sudo? */
if (user_uid == 0 && !def_root_sudo) {
warningx("sudoers specifies that root is not allowed to sudo");
goto done;
}
/* Check for -C overriding def_closefrom. */
if (user_closefrom >= 0 && user_closefrom != def_closefrom) {
if (!def_closefrom_override) {
warningx("you are not permitted to use the -C option");
goto done;
}
def_closefrom = user_closefrom;
}
if (sigsetjmp(error_jmp, 1)) {
/* error recovery via error(), errorx() or log_error() */
rewind_perms();
return -1;
}
set_perms(PERM_INITIAL);
/* Environment variables specified on the command line. */
if (env_add != NULL && env_add[0] != NULL)
sudo_user.env_vars = env_add;
/*
* Make a local copy of argc/argv, with special handling
* for the '-i' option.
*/
NewArgv = emalloc2(argc + 1, sizeof(char *));
memcpy(NewArgv, argv, argc * sizeof(char *));
NewArgv[argc] = NULL;
NewArgc = argc;
if (ISSET(sudo_mode, MODE_LOGIN_SHELL))
NewArgv[0] = runas_pw->pw_shell;
/* Find command in path */
cmnd_status = set_cmnd(sudo_mode);
if (cmnd_status == -1) {
rval = -1;
goto done;
}
#ifdef HAVE_SETLOCALE
if (!setlocale(LC_ALL, def_sudoers_locale)) {
warningx("unable to set locale to \"%s\", using \"C\"",
def_sudoers_locale);
setlocale(LC_ALL, "C");
}
#endif
/*
* Check sudoers sources.
*/
validated = FLAG_NO_USER | FLAG_NO_HOST;
tq_foreach_fwd(snl, nss) {
validated = nss->lookup(nss, validated, pwflag);
if (ISSET(validated, VALIDATE_OK)) {
/* Handle "= auth" in netsvc.conf */
if (nss->ret_if_found)
break;
} else {
/* Handle [NOTFOUND=return] */
if (nss->ret_if_notfound)
break;
}
}
if (safe_cmnd == NULL)
safe_cmnd = estrdup(user_cmnd);
#ifdef HAVE_SETLOCALE
setlocale(LC_ALL, "");
#endif
/* If only a group was specified, set runas_pw based on invoking user. */
if (runas_pw == NULL)
set_runaspw(user_name);
/*
* Look up the timestamp dir owner if one is specified.
*/
if (def_timestampowner) {
struct passwd *pw;
if (*def_timestampowner == '#')
pw = sudo_getpwuid(atoi(def_timestampowner + 1));
else
pw = sudo_getpwnam(def_timestampowner);
if (!pw)
log_error(0, "timestamp owner (%s): No such user",
def_timestampowner);
timestamp_uid = pw->pw_uid;
pw_delref(pw);
}
/* If given the -P option, set the "preserve_groups" flag. */
if (ISSET(sudo_mode, MODE_PRESERVE_GROUPS))
def_preserve_groups = TRUE;
/* If no command line args and "shell_noargs" is not set, error out. */
if (ISSET(sudo_mode, MODE_IMPLIED_SHELL) && !def_shell_noargs) {
rval = -2; /* usage error */
goto done;
}
/* Bail if a tty is required and we don't have one. */
if (def_requiretty) {
int fd = open(_PATH_TTY, O_RDWR|O_NOCTTY);
if (fd == -1) {
audit_failure(NewArgv, "no tty");
warningx("sorry, you must have a tty to run sudo");
goto done;
} else
(void) close(fd);
}
/*
* We don't reset the environment for sudoedit or if the user
* specified the -E command line flag and they have setenv privs.
*/
if (ISSET(sudo_mode, MODE_EDIT) ||
(ISSET(sudo_mode, MODE_PRESERVE_ENV) && def_setenv))
def_env_reset = FALSE;
/* Build a new environment that avoids any nasty bits. */
rebuild_env(def_noexec);
/* Fill in passwd struct based on user we are authenticating as. */
auth_pw = get_authpw();
/* Require a password if sudoers says so. */
if (def_authenticate) {
int rc = check_user(validated, sudo_mode);
if (rc != TRUE) {
rval = rc;
goto done;
}
}
/* If run as root with SUDO_USER set, set sudo_user.pw to that user. */
/* XXX - causes confusion when root is not listed in sudoers */
if (sudo_mode & (MODE_RUN | MODE_EDIT) && prev_user != NULL) {
if (user_uid == 0 && strcmp(prev_user, "root") != 0) {
struct passwd *pw;
if ((pw = sudo_getpwnam(prev_user)) != NULL) {
if (sudo_user.pw != NULL)
pw_delref(sudo_user.pw);
sudo_user.pw = pw;
#ifdef HAVE_MBR_CHECK_MEMBERSHIP
mbr_uid_to_uuid(user_uid, user_uuid);
#endif
}
}
}
/* If the user was not allowed to run the command we are done. */
if (!ISSET(validated, VALIDATE_OK)) {
if (ISSET(validated, FLAG_NO_USER | FLAG_NO_HOST)) {
audit_failure(NewArgv, "No user or host");
log_denial(validated, 1);
} else {
if (def_path_info) {
/*
* We'd like to not leak path info at all here, but that can
* *really* confuse the users. To really close the leak we'd
* have to say "not allowed to run foo" even when the problem
* is just "no foo in path" since the user can trivially set
* their path to just contain a single dir.
*/
log_denial(validated,
!(cmnd_status == NOT_FOUND_DOT || cmnd_status == NOT_FOUND));
if (cmnd_status == NOT_FOUND)
warningx("%s: command not found", user_cmnd);
else if (cmnd_status == NOT_FOUND_DOT)
warningx("ignoring `%s' found in '.'\nUse `sudo ./%s' if this is the `%s' you wish to run.", user_cmnd, user_cmnd, user_cmnd);
} else {
/* Just tell the user they are not allowed to run foo. */
log_denial(validated, 1);
}
audit_failure(NewArgv, "validation failure");
}
goto done;
}
/* Create Ubuntu-style dot file to indicate sudo was successful. */
create_admin_success_flag();
/* Finally tell the user if the command did not exist. */
if (cmnd_status == NOT_FOUND_DOT) {
audit_failure(NewArgv, "command in current directory");
warningx("ignoring `%s' found in '.'\nUse `sudo ./%s' if this is the `%s' you wish to run.", user_cmnd, user_cmnd, user_cmnd);
goto done;
} else if (cmnd_status == NOT_FOUND) {
audit_failure(NewArgv, "%s: command not found", user_cmnd);
warningx("%s: command not found", user_cmnd);
goto done;
}
/* If user specified env vars make sure sudoers allows it. */
if (ISSET(sudo_mode, MODE_RUN) && !def_setenv) {
if (ISSET(sudo_mode, MODE_PRESERVE_ENV)) {
warningx("sorry, you are not allowed to preserve the environment");
goto done;
} else
validate_env_vars(sudo_user.env_vars);
}
if (ISSET(sudo_mode, (MODE_RUN| MODE_EDIT)) && (def_log_input || def_log_output))
io_nextid();
log_allowed(validated);
if (ISSET(sudo_mode, MODE_CHECK))
rval = display_cmnd(snl, list_pw ? list_pw : sudo_user.pw);
else if (ISSET(sudo_mode, MODE_LIST))
display_privs(snl, list_pw ? list_pw : sudo_user.pw); /* XXX - return val */
/* Cleanup sudoers sources */
tq_foreach_fwd(snl, nss) {
nss->close(nss);
}
if (def_group_plugin)
group_plugin_unload();
if (ISSET(sudo_mode, (MODE_VALIDATE|MODE_CHECK|MODE_LIST)))
goto done;
/*
* Set umask based on sudoers.
* If user's umask is more restrictive, OR in those bits too
* unless umask_override is set.
*/
if (def_umask != 0777) {
mode_t mask = def_umask;
if (!def_umask_override) {
mode_t omask = umask(mask);
mask |= omask;
umask(omask);
}
easprintf(&command_info[info_len++], "umask=0%o", (unsigned int)mask);
}
if (ISSET(sudo_mode, MODE_LOGIN_SHELL)) {
char *p;
/* Convert /bin/sh -> -sh so shell knows it is a login shell */
if ((p = strrchr(NewArgv[0], '/')) == NULL)
p = NewArgv[0];
*p = '-';
NewArgv[0] = p;
/* Set cwd to run user's homedir. */
command_info[info_len++] = fmt_string("cwd", runas_pw->pw_dir);
#if defined(__linux__) || defined(_AIX)
/* Insert system-wide environment variables. */
read_env_file(_PATH_ENVIRONMENT, TRUE);
#endif
}
/* Insert system-wide environment variables. */
if (def_env_file)
read_env_file(def_env_file, FALSE);
/* Insert user-specified environment variables. */
insert_env_vars(sudo_user.env_vars);
/* Restore signal handlers before we exec. */
(void) sigaction(SIGINT, &saved_sa_int, NULL);
(void) sigaction(SIGQUIT, &saved_sa_quit, NULL);
(void) sigaction(SIGTSTP, &saved_sa_tstp, NULL);
if (ISSET(sudo_mode, MODE_EDIT)) {
char *editor = find_editor(NewArgc - 1, NewArgv + 1, &edit_argv);
if (!editor)
goto done;
command_info[info_len++] = fmt_string("command", editor);
command_info[info_len++] = estrdup("sudoedit=true");
} else {
command_info[info_len++] = fmt_string("command", safe_cmnd);
}
if (def_stay_setuid) {
easprintf(&command_info[info_len++], "runas_uid=%u",
(unsigned int)user_uid);
easprintf(&command_info[info_len++], "runas_gid=%u",
(unsigned int)user_gid);
easprintf(&command_info[info_len++], "runas_euid=%u",
(unsigned int)runas_pw->pw_uid);
easprintf(&command_info[info_len++], "runas_egid=%u",
(unsigned int)runas_pw->pw_gid);
} else {
easprintf(&command_info[info_len++], "runas_uid=%u",
(unsigned int)runas_pw->pw_uid);
easprintf(&command_info[info_len++], "runas_gid=%u",
(unsigned int)runas_pw->pw_gid);
}
if (def_preserve_groups) {
command_info[info_len++] = "preserve_groups=true";
} else if (runas_ngroups != -1) {
int i, len;
size_t glsize;
char *cp, *gid_list;
glsize = sizeof("runas_groups=") - 1 + (runas_ngroups * (MAX_UID_T_LEN + 1));
gid_list = emalloc(glsize);
memcpy(gid_list, "runas_groups=", sizeof("runas_groups=") - 1);
cp = gid_list + sizeof("runas_groups=") - 1;
for (i = 0; i < runas_ngroups; i++) {
/* XXX - check rval */
len = snprintf(cp, glsize - (cp - gid_list), "%s%lu",
i ? "," : "", (unsigned long)runas_groups[i]);
cp += len;
}
command_info[info_len++] = gid_list;
}
if (def_closefrom >= 0)
easprintf(&command_info[info_len++], "closefrom=%d", def_closefrom);
#ifdef HAVE_SELINUX
if (user_role != NULL)
command_info[info_len++] = fmt_string("selinux_role", user_role);
if (user_type != NULL)
command_info[info_len++] = fmt_string("selinux_type", user_type);
#endif /* HAVE_SELINUX */
/* Must audit before uid change. */
audit_success(NewArgv);
*command_infop = command_info;
*argv_out = edit_argv ? edit_argv : NewArgv;
*user_env_out = env_get(); /* our private copy */
rval = TRUE;
restore_perms();
done:
/* Close the password and group files and free up memory. */
sudo_endpwent();
sudo_endgrent();
return rval;
}
static int
sudoers_policy_check(int argc, char * const argv[], char *env_add[],
char **command_infop[], char **argv_out[], char **user_env_out[])
{
SET(sudo_mode, MODE_RUN);
return sudoers_policy_main(argc, argv, 0, env_add, command_infop,
argv_out, user_env_out);
}
static int
sudoers_policy_validate(void)
{
user_cmnd = "validate";
SET(sudo_mode, MODE_VALIDATE);
return sudoers_policy_main(0, NULL, I_VERIFYPW, NULL, NULL, NULL, NULL);
}
static void
sudoers_policy_invalidate(int remove)
{
user_cmnd = "kill";
if (sigsetjmp(error_jmp, 1) == 0) {
remove_timestamp(remove);
cleanup(0);
}
}
static int
sudoers_policy_list(int argc, char * const argv[], int verbose,
const char *list_user)
{
int rval;
user_cmnd = "list";
if (argc)
SET(sudo_mode, MODE_CHECK);
else
SET(sudo_mode, MODE_LIST);
if (verbose)
long_list = 1;
if (list_user) {
list_pw = sudo_getpwnam(list_user);
if (list_pw == NULL) {
warningx("unknown user: %s", list_user);
return -1;
}
}
rval = sudoers_policy_main(argc, argv, I_LISTPW, NULL, NULL, NULL, NULL);
if (list_user) {
pw_delref(list_pw);
list_pw = NULL;
}
return rval;
}
/*
* Initialize timezone, set umask, fill in ``sudo_user'' struct and
* load the ``interfaces'' array.
*/
static void
init_vars(char * const envp[])
{
char * const * ep;
#ifdef HAVE_TZSET
(void) tzset(); /* set the timezone if applicable */
#endif /* HAVE_TZSET */
for (ep = envp; *ep; ep++) {
/* XXX - don't fill in if empty string */
switch (**ep) {
case 'K':
if (strncmp("KRB5CCNAME=", *ep, 11) == 0)
user_ccname = *ep + 11;
break;
case 'P':
if (strncmp("PATH=", *ep, 5) == 0)
user_path = *ep + 5;
break;
case 'S':
if (!user_prompt && strncmp("SUDO_PROMPT=", *ep, 12) == 0)
user_prompt = *ep + 12;
else if (strncmp("SUDO_USER=", *ep, 10) == 0)
prev_user = *ep + 10;
break;
}
}
/*
* Get a local copy of the user's struct passwd with the shadow password
* if necessary. It is assumed that euid is 0 at this point so we
* can read the shadow passwd file if necessary.
*/
if ((sudo_user.pw = sudo_getpwnam(user_name)) == NULL) {
struct passwd pw;
/* Create a fake struct passwd for log_error(). */
memset(&pw, 0, sizeof(pw));
pw.pw_uid = getuid();
pw.pw_name = user_name;
sudo_user.pw = &pw;
/*
* It is not unusual for users to place "sudo -k" in a .logout
* file which can cause sudo to be run during reboot after the
* YP/NIS/NIS+/LDAP/etc daemon has died.
*/
if (sudo_mode == MODE_KILL || sudo_mode == MODE_INVALIDATE)
errorx(1, "unknown user: %s", user_name);
log_error(0, "unknown user: %s", user_name);
/* NOTREACHED */
}
#ifdef HAVE_MBR_CHECK_MEMBERSHIP
mbr_uid_to_uuid(user_uid, user_uuid);
#endif
/* It is now safe to use log_error() and set_perms() */
}
/*
* Fill in user_cmnd, user_args, user_base and user_stat variables
* and apply any command-specific defaults entries.
*/
static int
set_cmnd(int sudo_mode)
{
int rval;
char *path = user_path;
/* Set project if applicable. */
set_project(runas_pw);
/* Resolve the path and return. */
rval = FOUND;
user_stat = emalloc(sizeof(struct stat));
/* Default value for cmnd, overridden below. */
if (user_cmnd == NULL)
user_cmnd = NewArgv[0];
if (sudo_mode & (MODE_RUN | MODE_EDIT | MODE_CHECK)) {
if (ISSET(sudo_mode, MODE_RUN | MODE_CHECK)) {
if (def_secure_path && !user_is_exempt())
path = def_secure_path;
set_perms(PERM_RUNAS);
rval = find_path(NewArgv[0], &user_cmnd, user_stat, path,
def_ignore_dot);
restore_perms();
if (rval != FOUND) {
/* Failed as root, try as invoking user. */
set_perms(PERM_USER);
rval = find_path(NewArgv[0], &user_cmnd, user_stat, path,
def_ignore_dot);
restore_perms();
}
}
/* set user_args */
if (NewArgc > 1) {
char *to, **from;
size_t size, n;
/* Alloc and build up user_args. */
for (size = 0, from = NewArgv + 1; *from; from++)
size += strlen(*from) + 1;
user_args = emalloc(size);
for (to = user_args, from = NewArgv + 1; *from; from++) {
n = strlcpy(to, *from, size - (to - user_args));
if (n >= size - (to - user_args))
errorx(1, "internal error, set_cmnd() overflow");
to += n;
*to++ = ' ';
}
*--to = '\0';
}
}
if (strlen(user_cmnd) >= PATH_MAX)
errorx(1, "%s: file name too long", user_cmnd);
if ((user_base = strrchr(user_cmnd, '/')) != NULL)
user_base++;
else
user_base = user_cmnd;
if (!update_defaults(SETDEF_CMND))
log_error(NO_STDERR|NO_EXIT, "problem with defaults entries");
if (!runas_user && !runas_group)
set_runaspw(def_runas_default); /* may have been updated above */
return(rval);
}
/*
* Open sudoers and sanity check mode/owner/type.
* Returns a handle to the sudoers file or NULL on error.
*/
FILE *
open_sudoers(const char *sudoers, int doedit, int *keepopen)
{
struct stat statbuf;
FILE *fp = NULL;
int rootstat;
/*
* Fix the mode and group on sudoers file from old default.
* Only works if file system is readable/writable by root.
*/
if ((rootstat = stat_sudoers(sudoers, &statbuf)) == 0 &&
SUDOERS_UID == statbuf.st_uid && SUDOERS_MODE != 0400 &&
(statbuf.st_mode & 0007777) == 0400) {
if (chmod(sudoers, SUDOERS_MODE) == 0) {
warningx("fixed mode on %s", sudoers);
SET(statbuf.st_mode, SUDOERS_MODE);
if (statbuf.st_gid != SUDOERS_GID) {
if (chown(sudoers, (uid_t) -1, SUDOERS_GID) == 0) {
warningx("set group on %s", sudoers);
statbuf.st_gid = SUDOERS_GID;
} else
warning("unable to set group on %s", sudoers);
}
} else
warning("unable to fix mode on %s", sudoers);
}
/*
* Sanity checks on sudoers file. Must be done as sudoers
* file owner. We already did a stat as root, so use that
* data if we can't stat as sudoers file owner.
*/
set_perms(PERM_SUDOERS);
if (rootstat != 0 && stat_sudoers(sudoers, &statbuf) != 0)
log_error(USE_ERRNO|NO_EXIT, "can't stat %s", sudoers);
else if (!S_ISREG(statbuf.st_mode))
log_error(NO_EXIT, "%s is not a regular file", sudoers);
else if ((statbuf.st_mode & 07777) != SUDOERS_MODE)
log_error(NO_EXIT, "%s is mode 0%o, should be 0%o", sudoers,
(unsigned int) (statbuf.st_mode & 07777),
(unsigned int) SUDOERS_MODE);
else if (statbuf.st_uid != SUDOERS_UID)
log_error(NO_EXIT, "%s is owned by uid %lu, should be %lu", sudoers,
(unsigned long) statbuf.st_uid, (unsigned long) SUDOERS_UID);
else if (statbuf.st_gid != SUDOERS_GID)
log_error(NO_EXIT, "%s is owned by gid %lu, should be %lu", sudoers,
(unsigned long) statbuf.st_gid, (unsigned long) SUDOERS_GID);
else if ((fp = fopen(sudoers, "r")) == NULL)
log_error(USE_ERRNO|NO_EXIT, "can't open %s", sudoers);
else {
/*
* Make sure we can actually read sudoers so we can present the
* user with a reasonable error message (unlike the lexer).
*/
if (statbuf.st_size != 0 && fgetc(fp) == EOF) {
log_error(USE_ERRNO|NO_EXIT, "can't read %s", sudoers);
fclose(fp);
fp = NULL;
}
}
if (fp != NULL) {
rewind(fp);
(void) fcntl(fileno(fp), F_SETFD, 1);
}
restore_perms(); /* change back to root */
return(fp);
}
#ifdef HAVE_LOGIN_CAP_H
static void
set_loginclass(struct passwd *pw)
{
int errflags;
/*
* Don't make it a fatal error if the user didn't specify the login
* class themselves. We do this because if login.conf gets
* corrupted we want the admin to be able to use sudo to fix it.
*/
if (login_class)
errflags = NO_MAIL|MSG_ONLY;
else
errflags = NO_MAIL|MSG_ONLY|NO_EXIT;
if (login_class && strcmp(login_class, "-") != 0) {
if (user_uid != 0 &&
strcmp(runas_user ? runas_user : def_runas_default, "root") != 0)
errorx(1, "only root can use -c %s", login_class);
} else {
login_class = pw->pw_class;
if (!login_class || !*login_class)
login_class =
(pw->pw_uid == 0) ? LOGIN_DEFROOTCLASS : LOGIN_DEFCLASS;
}
lc = login_getclass(login_class);
if (!lc || !lc->lc_class || strcmp(lc->lc_class, login_class) != 0) {
log_error(errflags, "unknown login class: %s", login_class);
if (!lc)
lc = login_getclass(NULL); /* needed for login_getstyle() later */
}
}
#else
static void
set_loginclass(struct passwd *pw)
{
}
#endif /* HAVE_LOGIN_CAP_H */
#ifdef HAVE_PROJECT_H
static void
set_project(struct passwd *pw)
{
int errflags = NO_MAIL|MSG_ONLY|NO_EXIT;
int errval;
struct project proj;
struct project *resultp = '\0';
char buf[1024];
/*
* Collect the default project for the user and settaskid
*/
setprojent();
if (resultp = getdefaultproj(pw->pw_name, &proj, buf, sizeof(buf))) {
errval = setproject(resultp->pj_name, pw->pw_name, TASK_NORMAL);
if (errval != 0) {
switch(errval) {
case SETPROJ_ERR_TASK:
if (errno == EAGAIN)
log_error(errflags, "resource control limit has been reached");
else if (errno == ESRCH)
log_error(errflags, "user \"%s\" is not a member of "
"project \"%s\"", pw->pw_name, resultp->pj_name);
else if (errno == EACCES)
log_error(errflags, "the invoking task is final");
else
log_error(errflags, "could not join project \"%s\"",
resultp->pj_name);
break;
case SETPROJ_ERR_POOL:
if (errno == EACCES)
log_error(errflags, "no resource pool accepting "
"default bindings exists for project \"%s\"",
resultp->pj_name);
else if (errno == ESRCH)
log_error(errflags, "specified resource pool does "
"not exist for project \"%s\"", resultp->pj_name);
else
log_error(errflags, "could not bind to default "
"resource pool for project \"%s\"", resultp->pj_name);
break;
default:
if (errval <= 0) {
log_error(errflags, "setproject failed for project \"%s\"",
resultp->pj_name);
} else {
log_error(errflags, "warning, resource control assignment "
"failed for project \"%s\"", resultp->pj_name);
}
}
}
} else {
log_error(errflags, "getdefaultproj() error: %s", strerror(errno));
}
endprojent();
}
#else
static void
set_project(struct passwd *pw)
{
}
#endif /* HAVE_PROJECT_H */
/*
* Look up the fully qualified domain name and set user_host and user_shost.
*/
void
set_fqdn(void)
{
#ifdef HAVE_GETADDRINFO
struct addrinfo *res0, hint;
#else
struct hostent *hp;
#endif
char *p;
#ifdef HAVE_GETADDRINFO
zero_bytes(&hint, sizeof(hint));
hint.ai_family = PF_UNSPEC;
hint.ai_flags = AI_CANONNAME;
if (getaddrinfo(user_host, NULL, &hint, &res0) != 0) {
#else
if (!(hp = gethostbyname(user_host))) {
#endif
log_error(MSG_ONLY|NO_EXIT,
"unable to resolve host %s", user_host);
} else {
if (user_shost != user_host)
efree(user_shost);
efree(user_host);
#ifdef HAVE_GETADDRINFO
user_host = estrdup(res0->ai_canonname);
freeaddrinfo(res0);
#else
user_host = estrdup(hp->h_name);
#endif
}
if ((p = strchr(user_host, '.')) != NULL)
user_shost = estrndup(user_host, (size_t)(p - user_host));
else
user_shost = user_host;
}
/*
* Get passwd entry for the user we are going to run commands as
* and store it in runas_pw. By default, commands run as "root".
*/
static void
set_runaspw(char *user)
{
if (runas_pw != NULL)
pw_delref(runas_pw);
if (*user == '#') {
if ((runas_pw = sudo_getpwuid(atoi(user + 1))) == NULL)
runas_pw = sudo_fakepwnam(user, runas_gr ? runas_gr->gr_gid : 0);
} else {
if ((runas_pw = sudo_getpwnam(user)) == NULL) {
audit_failure(NewArgv, "unknown user: %s", user);
log_error(NO_MAIL|MSG_ONLY, "unknown user: %s", user);
}
}
}
/*
* Get group entry for the group we are going to run commands as
* and store it in runas_gr.
*/
static void
set_runasgr(char *group)
{
if (runas_gr != NULL)
gr_delref(runas_gr);
if (*group == '#') {
if ((runas_gr = sudo_getgrgid(atoi(group + 1))) == NULL)
runas_gr = sudo_fakegrnam(group);
} else {
if ((runas_gr = sudo_getgrnam(group)) == NULL)
log_error(NO_MAIL|MSG_ONLY, "unknown group: %s", group);
}
}
/*
* Get passwd entry for the user we are going to authenticate as.
* By default, this is the user invoking sudo. In the most common
* case, this matches sudo_user.pw or runas_pw.
*/
static struct passwd *
get_authpw(void)
{
struct passwd *pw;
if (def_rootpw) {
if ((pw = sudo_getpwuid(0)) == NULL)
log_error(0, "unknown uid: 0");
} else if (def_runaspw) {
if ((pw = sudo_getpwnam(def_runas_default)) == NULL)
log_error(0, "unknown user: %s", def_runas_default);
} else if (def_targetpw) {
if (runas_pw->pw_name == NULL)
log_error(NO_MAIL|MSG_ONLY, "unknown uid: %lu",
(unsigned long) runas_pw->pw_uid);
pw_addref(runas_pw);
pw = runas_pw;
} else {
pw_addref(sudo_user.pw);
pw = sudo_user.pw;
}
return(pw);
}
/*
* Cleanup hook for error()/errorx()
*/
void
cleanup(int gotsignal)
{
struct sudo_nss *nss;
if (!gotsignal) {
if (snl != NULL) {
tq_foreach_fwd(snl, nss)
nss->close(nss);
}
if (def_group_plugin)
group_plugin_unload();
sudo_endpwent();
sudo_endgrent();
}
}
static int
sudoers_policy_version(int verbose)
{
sudo_printf(SUDO_CONV_INFO_MSG, "Sudoers policy plugin version %s\n",
PACKAGE_VERSION);
if (verbose) {
sudo_printf(SUDO_CONV_INFO_MSG, "\nSudoers path: %s\n", _PATH_SUDOERS);
#ifdef HAVE_LDAP
# ifdef _PATH_NSSWITCH_CONF
sudo_printf(SUDO_CONV_INFO_MSG, "nsswitch path: %s\n", _PATH_NSSWITCH_CONF);
# endif
sudo_printf(SUDO_CONV_INFO_MSG, "ldap.conf path: %s\n", _PATH_LDAP_CONF);
sudo_printf(SUDO_CONV_INFO_MSG, "ldap.secret path: %s\n", _PATH_LDAP_SECRET);
#endif
dump_auth_methods();
dump_defaults();
sudo_printf(SUDO_CONV_INFO_MSG, "\n");
dump_interfaces();
sudo_printf(SUDO_CONV_INFO_MSG, "\n");
}
return TRUE;
}
static int
deserialize_info(char * const settings[], char * const user_info[])
{
char * const *cur;
const char *p;
int flags = 0;
#define MATCHES(s, v) (strncmp(s, v, sizeof(v) - 1) == 0)
/* Parse command line settings. */
user_closefrom = -1;
for (cur = settings; *cur != NULL; cur++) {
if (MATCHES(*cur, "closefrom=")) {
user_closefrom = atoi(*cur + sizeof("closefrom=") - 1);
continue;
}
if (MATCHES(*cur, "debug_level=")) {
debug_level = atoi(*cur + sizeof("debug_level=") - 1);
continue;
}
if (MATCHES(*cur, "runas_user=")) {
runas_user = *cur + sizeof("runas_user=") - 1;
continue;
}
if (MATCHES(*cur, "runas_group=")) {
runas_group = *cur + sizeof("runas_group=") - 1;
continue;
}
if (MATCHES(*cur, "prompt=")) {
user_prompt = *cur + sizeof("prompt=") - 1;
def_passprompt_override = TRUE;
continue;
}
if (MATCHES(*cur, "set_home=")) {
if (atobool(*cur + sizeof("set_home=") - 1) == TRUE)
SET(flags, MODE_RESET_HOME);
continue;
}
if (MATCHES(*cur, "preserve_environment=")) {
if (atobool(*cur + sizeof("preserve_environment=") - 1) == TRUE)
SET(flags, MODE_PRESERVE_ENV);
continue;
}
if (MATCHES(*cur, "login_shell=")) {
if (atobool(*cur + sizeof("login_shell=") - 1) == TRUE) {
SET(flags, MODE_LOGIN_SHELL);
def_env_reset = TRUE;
}
continue;
}
if (MATCHES(*cur, "implied_shell=")) {
if (atobool(*cur + sizeof("implied_shell=") - 1) == TRUE)
SET(flags, MODE_IMPLIED_SHELL);
continue;
}
if (MATCHES(*cur, "preserve_groups=")) {
if (atobool(*cur + sizeof("preserve_groups=") - 1) == TRUE)
SET(flags, MODE_PRESERVE_GROUPS);
continue;
}
if (MATCHES(*cur, "ignore_ticket=")) {
if (atobool(*cur + sizeof("ignore_ticket=") - 1) == TRUE)
SET(flags, MODE_IGNORE_TICKET);
continue;
}
if (MATCHES(*cur, "sudoedit=")) {
if (atobool(*cur + sizeof("sudoedit=") - 1) == TRUE)
SET(flags, MODE_EDIT);
continue;
}
if (MATCHES(*cur, "login_class=")) {
login_class = *cur + sizeof("login_class=") - 1;
def_use_loginclass = TRUE;
continue;
}
#ifdef HAVE_SELINUX
if (MATCHES(*cur, "selinux_role=")) {
user_role = *cur + sizeof("selinux_role=") - 1;
continue;
}
if (MATCHES(*cur, "selinux_type=")) {
user_type = *cur + sizeof("selinux_type=") - 1;
continue;
}
#endif /* HAVE_SELINUX */
#ifdef HAVE_BSD_AUTH_H
if (MATCHES(*cur, "bsdauth_type=")) {
login_style = *cur + sizeof("bsdauth_type=") - 1;
continue;
}
#endif /* HAVE_BSD_AUTH_H */
#if !defined(HAVE_GETPROGNAME) && !defined(HAVE___PROGNAME)
if (MATCHES(*cur, "progname=")) {
setprogname(*cur + sizeof("progname=") - 1);
continue;
}
#endif
}
for (cur = user_info; *cur != NULL; cur++) {
if (MATCHES(*cur, "user=")) {
user_name = estrdup(*cur + sizeof("user=") - 1);
continue;
}
if (MATCHES(*cur, "uid=")) {
user_uid = atoi(*cur + sizeof("uid=") - 1);
continue;
}
if (MATCHES(*cur, "gid=")) {
user_gid = atoi(*cur + sizeof("gid=") - 1);
continue;
}
if (MATCHES(*cur, "groups=")) {
/* Count number of groups */
const char *val = *cur + sizeof("groups=") - 1;
const char *cp;
if (val[0] != '\0') {
user_ngroups = 1;
for (cp = val; *cp != '\0'; cp++) {
if (*cp == ',')
user_ngroups++;
}
user_groups = emalloc2(user_ngroups, sizeof(GETGROUPS_T));
user_ngroups = 0;
cp = val;
for (;;) {
/* XXX - strtol would be better here */
user_groups[user_ngroups++] = atoi(cp);
cp = strchr(cp, ',');
if (cp == NULL)
break;
cp++; /* skip over comma */
}
}
continue;
}
if (MATCHES(*cur, "cwd=")) {
user_cwd = estrdup(*cur + sizeof("cwd=") - 1);
continue;
}
if (MATCHES(*cur, "tty=")) {
user_tty = user_ttypath = estrdup(*cur + sizeof("tty=") - 1);
if (strncmp(user_tty, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
user_tty += sizeof(_PATH_DEV) - 1;
continue;
}
if (MATCHES(*cur, "host=")) {
user_host = user_shost = estrdup(*cur + sizeof("host=") - 1);
if ((p = strchr(user_host, '.')))
user_shost = estrndup(user_host, (size_t)(p - user_host));
continue;
}
if (MATCHES(*cur, "lines=")) {
sudo_user.lines = atoi(*cur + sizeof("lines=") - 1);
continue;
}
if (MATCHES(*cur, "cols=")) {
sudo_user.cols = atoi(*cur + sizeof("cols=") - 1);
continue;
}
}
if (user_cwd == NULL)
user_cwd = "unknown";
if (user_tty == NULL)
user_tty = "unknown"; /* user_ttypath remains NULL */
#undef MATCHES
return flags;
}
static char *
resolve_editor(char *editor, int nfiles, char **files, char ***argv_out)
{
char *cp, **nargv, *editor_path = NULL;
int ac, i, nargc, wasblank;
editor = estrdup(editor); /* becomes part of argv_out */
/*
* Split editor into an argument vector; editor is reused (do not free).
* The EDITOR and VISUAL environment variables may contain command
* line args so look for those and alloc space for them too.
*/
nargc = 1;
for (wasblank = FALSE, cp = editor; *cp != '\0'; cp++) {
if (isblank((unsigned char) *cp))
wasblank = TRUE;
else if (wasblank) {
wasblank = FALSE;
nargc++;
}
}
/* If we can't find the editor in the user's PATH, give up. */
cp = strtok(editor, " \t");
if (cp == NULL ||
find_path(cp, &editor_path, NULL, getenv("PATH"), 0) != FOUND) {
efree(editor);
return NULL;
}
nargv = (char **) emalloc2(nargc + 1 + nfiles + 1, sizeof(char *));
for (ac = 0; cp != NULL && ac < nargc; ac++) {
nargv[ac] = cp;
cp = strtok(NULL, " \t");
}
nargv[ac++] = "--";
for (i = 0; i < nfiles; )
nargv[ac++] = files[i++];
nargv[ac] = NULL;
*argv_out = nargv;
return editor_path;
}
/*
* Determine which editor to use. We don't need to worry about restricting
* this to a "safe" editor since it runs with the uid of the invoking user,
* not the runas (privileged) user.
*/
static char *
find_editor(int nfiles, char **files, char ***argv_out)
{
char *cp, *editor, *editor_path = NULL, **ev, *ev0[4];
/*
* If any of SUDO_EDITOR, VISUAL or EDITOR are set, choose the first one.
*/
ev0[0] = "SUDO_EDITOR";
ev0[1] = "VISUAL";
ev0[2] = "EDITOR";
ev0[3] = NULL;
for (ev = ev0; *ev != NULL; ev++) {
if ((editor = getenv(*ev)) != NULL && *editor != '\0') {
editor_path = resolve_editor(editor, nfiles, files, argv_out);
if (editor_path != NULL)
break;
}
}
if (editor_path == NULL) {
/* def_editor could be a path, split it up */
editor = estrdup(def_editor);
cp = strtok(editor, ":");
while (cp != NULL && editor_path == NULL) {
editor_path = resolve_editor(cp, nfiles, files, argv_out);
cp = strtok(NULL, ":");
}
if (editor_path)
efree(editor);
}
if (!editor_path) {
audit_failure(NewArgv, "%s: command not found", editor);
warningx("%s: command not found", editor);
}
return editor_path;
}
#ifdef USE_ADMIN_FLAG
static void
create_admin_success_flag(void)
{
struct stat statbuf;
char flagfile[PATH_MAX];
int fd, n;
/* Check whether the user is in the admin group. */
if (!user_in_group(sudo_user.pw, "admin"))
return;
/* Build path to flag file. */
n = snprintf(flagfile, sizeof(flagfile), "%s/.sudo_as_admin_successful",
user_dir);
if (n <= 0 || n >= sizeof(flagfile))
return;
/* Create admin flag file if it doesn't already exist. */
set_perms(PERM_USER);
if (stat(flagfile, &statbuf) == 0) {
set_perms(PERM_ROOT);
return;
}
fd = open(flagfile, O_CREAT|O_WRONLY|O_EXCL, 0644);
close(fd);
set_perms(PERM_ROOT);
}
#else /* !USE_ADMIN_FLAG */
static void
create_admin_success_flag(void)
{
/* STUB */
}
#endif /* USE_ADMIN_FLAG */
struct policy_plugin sudoers_policy = {
SUDO_POLICY_PLUGIN,
SUDO_API_VERSION,
sudoers_policy_open,
sudoers_policy_close,
sudoers_policy_version,
sudoers_policy_check,
sudoers_policy_list,
sudoers_policy_validate,
sudoers_policy_invalidate,
sudoers_policy_init_session
};
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