NetBSD-5.0.2/usr.bin/login/login_pam.c
/* $NetBSD: login_pam.c,v 1.19 2008/07/21 14:19:23 lukem Exp $ */
/*-
* Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994\
The Regents of the University of California. All rights reserved.");
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)login.c 8.4 (Berkeley) 4/2/94";
#endif
__RCSID("$NetBSD: login_pam.c,v 1.19 2008/07/21 14:19:23 lukem Exp $");
#endif /* not lint */
/*
* login [ name ]
* login -h hostname (for telnetd, etc.)
* login -f name (for pre-authenticated login: datakit, xterm, etc.)
*/
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/file.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <err.h>
#include <errno.h>
#include <grp.h>
#include <pwd.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <time.h>
#include <ttyent.h>
#include <tzfile.h>
#include <unistd.h>
#include <util.h>
#include <login_cap.h>
#include <vis.h>
#include <security/pam_appl.h>
#include <security/openpam.h>
#include "pathnames.h"
void badlogin (char *);
static void update_db (int);
void getloginname (void);
int main (int, char *[]);
void motd (char *);
int rootterm (char *);
void sigint (int);
void sleepexit (int);
const char *stypeof (const char *);
void timedout (int);
void decode_ss (const char *);
void usage (void);
static struct pam_conv pamc = { openpam_ttyconv, NULL };
#define TTYGRPNAME "tty" /* name of group to own ttys */
#define DEFAULT_BACKOFF 3
#define DEFAULT_RETRIES 10
/*
* This bounds the time given to login. Not a define so it can
* be patched on machines where it's too small.
*/
u_int timeout = 300;
struct passwd *pwd, pwres;
char pwbuf[1024];
struct group grs, *grp;
char grbuf[1024];
int failures, have_ss;
char term[64], *envinit[1], *hostname, *username, *tty, *nested;
struct timeval now;
struct sockaddr_storage ss;
extern const char copyrightstr[];
int
main(int argc, char *argv[])
{
extern char **environ;
struct stat st;
int ask, ch, cnt, fflag, pflag, quietlog, rootlogin;
int auth_passed;
uid_t uid, saved_uid;
gid_t saved_gid, saved_gids[NGROUPS_MAX];
int nsaved_gids;
char *domain, *p, *ttyn, *pwprompt;
char tbuf[MAXPATHLEN + 2], tname[sizeof(_PATH_TTY) + 10];
char localhost[MAXHOSTNAMELEN + 1];
int need_chpass, require_chpass;
int login_retries = DEFAULT_RETRIES,
login_backoff = DEFAULT_BACKOFF;
char *shell = NULL;
login_cap_t *lc = NULL;
pam_handle_t *pamh = NULL;
int pam_err;
sig_t oint, oabrt, oquit, oalrm;
const void *newuser;
int pam_silent = PAM_SILENT;
pid_t xpid, pid;
int status;
char *saved_term;
char **pamenv;
tbuf[0] = '\0';
pwprompt = NULL;
nested = NULL;
need_chpass = require_chpass = 0;
oabrt = signal(SIGABRT, SIG_IGN);
oalrm = signal(SIGALRM, timedout);
oint = signal(SIGINT, SIG_IGN);
oquit = signal(SIGQUIT, SIG_IGN);
(void)alarm(timeout);
(void)setpriority(PRIO_PROCESS, 0, 0);
openlog("login", 0, LOG_AUTH);
/*
* -p is used by getty to tell login not to destroy the environment
* -f is used to skip a second login authentication
* -h is used by other servers to pass the name of the remote host to
* login so that it may be placed in utmp/utmpx and wtmp/wtmpx
* -a in addition to -h, a server my supply -a to pass the actual
* server address.
*/
domain = NULL;
if (gethostname(localhost, sizeof(localhost)) < 0)
syslog(LOG_ERR, "couldn't get local hostname: %m");
else
domain = strchr(localhost, '.');
localhost[sizeof(localhost) - 1] = '\0';
fflag = pflag = 0;
have_ss = 0;
uid = getuid();
while ((ch = getopt(argc, argv, "a:fh:p")) != -1)
switch (ch) {
case 'a':
if (uid) {
errno = EPERM;
err(EXIT_FAILURE, "-a option");
}
decode_ss(optarg);
#ifdef notdef
(void)sockaddr_snprintf(optarg,
sizeof(struct sockaddr_storage), "%a", (void *)&ss);
#endif
break;
case 'f':
fflag = 1;
break;
case 'h':
if (uid) {
errno = EPERM;
err(EXIT_FAILURE, "-h option");
}
if (domain && (p = strchr(optarg, '.')) != NULL &&
strcasecmp(p, domain) == 0)
*p = '\0';
hostname = optarg;
break;
case 'p':
pflag = 1;
break;
default:
case '?':
usage();
break;
}
setproctitle(NULL);
argc -= optind;
argv += optind;
if (*argv) {
username = *argv;
ask = 0;
} else
ask = 1;
#ifdef F_CLOSEM
(void)fcntl(3, F_CLOSEM, 0);
#else
for (cnt = getdtablesize(); cnt > 2; cnt--)
(void)close(cnt);
#endif
ttyn = ttyname(STDIN_FILENO);
if (ttyn == NULL || *ttyn == '\0') {
(void)snprintf(tname, sizeof(tname), "%s??", _PATH_TTY);
ttyn = tname;
}
if ((tty = strstr(ttyn, "/pts/")) != NULL)
++tty;
else if ((tty = strrchr(ttyn, '/')) != NULL)
++tty;
else
tty = ttyn;
if (issetugid()) {
nested = strdup(user_from_uid(getuid(), 0));
if (nested == NULL) {
syslog(LOG_ERR, "strdup: %m");
sleepexit(EXIT_FAILURE);
}
}
/* Get "login-retries" and "login-backoff" from default class */
if ((lc = login_getclass(NULL)) != NULL) {
login_retries = (int)login_getcapnum(lc, "login-retries",
DEFAULT_RETRIES, DEFAULT_RETRIES);
login_backoff = (int)login_getcapnum(lc, "login-backoff",
DEFAULT_BACKOFF, DEFAULT_BACKOFF);
login_close(lc);
lc = NULL;
}
for (cnt = 0;; ask = 1) {
if (ask) {
fflag = 0;
getloginname();
}
rootlogin = 0;
auth_passed = 0;
if (strlen(username) > MAXLOGNAME)
username[MAXLOGNAME] = '\0';
/*
* Note if trying multiple user names; log failures for
* previous user name, but don't bother logging one failure
* for nonexistent name (mistyped username).
*/
if (failures && strcmp(tbuf, username)) {
if (failures > (pwd ? 0 : 1))
badlogin(tbuf);
failures = 0;
}
#define PAM_END(msg) do { \
syslog(LOG_ERR, "%s: %s", msg, pam_strerror(pamh, pam_err)); \
warnx("%s: %s", msg, pam_strerror(pamh, pam_err)); \
pam_end(pamh, pam_err); \
sleepexit(EXIT_FAILURE); \
} while (/*CONSTCOND*/0)
pam_err = pam_start("login", username, &pamc, &pamh);
if (pam_err != PAM_SUCCESS) {
if (pamh != NULL)
PAM_END("pam_start");
/* Things went really bad... */
syslog(LOG_ERR, "pam_start failed: %s",
pam_strerror(pamh, pam_err));
errx(EXIT_FAILURE, "pam_start failed");
}
#define PAM_SET_ITEM(item, var) do { \
pam_err = pam_set_item(pamh, (item), (var)); \
if (pam_err != PAM_SUCCESS) \
PAM_END("pam_set_item(" # item ")"); \
} while (/*CONSTCOND*/0)
/*
* Fill hostname tty, and nested user
*/
PAM_SET_ITEM(PAM_RHOST, hostname);
PAM_SET_ITEM(PAM_TTY, tty);
if (nested)
PAM_SET_ITEM(PAM_NUSER, nested);
if (have_ss)
PAM_SET_ITEM(PAM_SOCKADDR, &ss);
/*
* Don't check for errors, because we don't want to give
* out any information.
*/
pwd = NULL;
(void)getpwnam_r(username, &pwres, pwbuf, sizeof(pwbuf), &pwd);
/*
* Establish the class now, before we might goto
* within the next block. pwd can be NULL since it
* falls back to the "default" class if it is.
*/
lc = login_getclass(pwd ? pwd->pw_class : NULL);
/*
* if we have a valid account name, and it doesn't have a
* password, or the -f option was specified and the caller
* is root or the caller isn't changing their uid, don't
* authenticate.
*/
if (pwd) {
if (pwd->pw_uid == 0)
rootlogin = 1;
if (fflag && (uid == 0 || uid == pwd->pw_uid)) {
/* already authenticated */
auth_passed = 1;
goto skip_auth;
}
}
(void)setpriority(PRIO_PROCESS, 0, -4);
switch(pam_err = pam_authenticate(pamh, pam_silent)) {
case PAM_SUCCESS:
/*
* PAM can change the user, refresh
* username, pwd, and lc.
*/
pam_err = pam_get_item(pamh, PAM_USER, &newuser);
if (pam_err != PAM_SUCCESS)
PAM_END("pam_get_item(PAM_USER)");
username = (char *)newuser;
/*
* Don't check for errors, because we don't want to give
* out any information.
*/
pwd = NULL;
(void)getpwnam_r(username, &pwres, pwbuf, sizeof(pwbuf),
&pwd);
lc = login_getpwclass(pwd);
auth_passed = 1;
switch (pam_err = pam_acct_mgmt(pamh, pam_silent)) {
case PAM_SUCCESS:
break;
case PAM_NEW_AUTHTOK_REQD:
pam_err = pam_chauthtok(pamh,
pam_silent|PAM_CHANGE_EXPIRED_AUTHTOK);
if (pam_err != PAM_SUCCESS)
PAM_END("pam_chauthtok");
break;
case PAM_AUTH_ERR:
case PAM_USER_UNKNOWN:
case PAM_MAXTRIES:
auth_passed = 0;
break;
default:
PAM_END("pam_acct_mgmt");
break;
}
break;
case PAM_AUTH_ERR:
case PAM_USER_UNKNOWN:
case PAM_MAXTRIES:
auth_passed = 0;
break;
default:
PAM_END("pam_authenticate");
break;
}
(void)setpriority(PRIO_PROCESS, 0, 0);
skip_auth:
/*
* If the user exists and authentication passed,
* get out of the loop and login the user.
*/
if (pwd && auth_passed)
break;
(void)printf("Login incorrect or refused on this terminal.\n");
failures++;
cnt++;
/*
* We allow login_retries tries, but after login_backoff
* we start backing off. These default to 10 and 3
* respectively.
*/
if (cnt > login_backoff) {
if (cnt >= login_retries) {
badlogin(username);
pam_end(pamh, PAM_SUCCESS);
sleepexit(EXIT_FAILURE);
}
sleep((u_int)((cnt - login_backoff) * 5));
}
}
/* committed to login -- turn off timeout */
(void)alarm((u_int)0);
endpwent();
quietlog = login_getcapbool(lc, "hushlogin", 0);
/*
* Temporarily give up special privileges so we can change
* into NFS-mounted homes that are exported for non-root
* access and have mode 7x0
*/
saved_uid = geteuid();
saved_gid = getegid();
nsaved_gids = getgroups(NGROUPS_MAX, saved_gids);
(void)setegid(pwd->pw_gid);
initgroups(username, pwd->pw_gid);
(void)seteuid(pwd->pw_uid);
if (chdir(pwd->pw_dir) != 0) {
if (login_getcapbool(lc, "requirehome", 0)) {
(void)printf("Home directory %s required\n",
pwd->pw_dir);
pam_end(pamh, PAM_SUCCESS);
exit(EXIT_FAILURE);
}
(void)printf("No home directory %s!\n", pwd->pw_dir);
if (chdir("/") == -1) {
pam_end(pamh, PAM_SUCCESS);
exit(EXIT_FAILURE);
}
pwd->pw_dir = "/";
(void)printf("Logging in with home = \"/\".\n");
}
if (!quietlog) {
quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0;
pam_silent = quietlog ? PAM_SILENT : 0;
}
/* regain special privileges */
setegid(saved_gid);
setgroups(nsaved_gids, saved_gids);
seteuid(saved_uid);
(void)getgrnam_r(TTYGRPNAME, &grs, grbuf, sizeof(grbuf), &grp);
(void)chown(ttyn, pwd->pw_uid,
(grp != NULL) ? grp->gr_gid : pwd->pw_gid);
if (ttyaction(ttyn, "login", pwd->pw_name))
(void)printf("Warning: ttyaction failed.\n");
/* Nothing else left to fail -- really log in. */
update_db(quietlog);
if (nested == NULL && setusercontext(lc, pwd, pwd->pw_uid,
LOGIN_SETLOGIN) != 0) {
syslog(LOG_ERR, "setusercontext failed");
pam_end(pamh, PAM_SUCCESS);
exit(EXIT_FAILURE);
}
if (tty[sizeof("tty")-1] == 'd')
syslog(LOG_INFO, "DIALUP %s, %s", tty, pwd->pw_name);
/* If fflag is on, assume caller/authenticator has logged root login. */
if (rootlogin && fflag == 0) {
if (hostname)
syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s FROM %s",
username, tty, hostname);
else
syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s",
username, tty);
}
/*
* Establish groups
*/
if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETGROUP) != 0) {
syslog(LOG_ERR, "setusercontext failed");
pam_end(pamh, PAM_SUCCESS);
exit(EXIT_FAILURE);
}
pam_err = pam_setcred(pamh, pam_silent|PAM_ESTABLISH_CRED);
if (pam_err != PAM_SUCCESS)
PAM_END("pam_setcred");
pam_err = pam_open_session(pamh, pam_silent);
if (pam_err != PAM_SUCCESS)
PAM_END("pam_open_session");
/*
* Fork because we need to call pam_closesession as root.
* Make sure signals cannot kill the parent.
* This has been handled in the begining of main.
*/
switch(pid = fork()) {
case -1:
pam_err = pam_close_session(pamh, 0);
if (pam_err != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_close_session: %s",
pam_strerror(pamh, pam_err));
warnx("pam_close_session: %s",
pam_strerror(pamh, pam_err));
}
syslog(LOG_ERR, "fork failed: %m");
warn("fork failed");
pam_end(pamh, pam_err);
exit(EXIT_FAILURE);
break;
case 0: /* Child */
break;
default:
/*
* Parent: wait for the child to terminate
* and call pam_close_session.
*/
if ((xpid = waitpid(pid, &status, 0)) != pid) {
pam_err = pam_close_session(pamh, 0);
if (pam_err != PAM_SUCCESS) {
syslog(LOG_ERR,
"pam_close_session: %s",
pam_strerror(pamh, pam_err));
warnx("pam_close_session: %s",
pam_strerror(pamh, pam_err));
}
pam_end(pamh, pam_err);
if (xpid != -1)
warnx("wrong PID: %d != %d", pid, xpid);
else
warn("wait for pid %d failed", pid);
exit(EXIT_FAILURE);
}
(void)signal(SIGABRT, oabrt);
(void)signal(SIGALRM, oalrm);
(void)signal(SIGINT, oint);
(void)signal(SIGQUIT, oquit);
if ((pam_err = pam_close_session(pamh, 0)) != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_close_session: %s",
pam_strerror(pamh, pam_err));
warnx("pam_close_session: %s",
pam_strerror(pamh, pam_err));
}
pam_end(pamh, PAM_SUCCESS);
exit(EXIT_SUCCESS);
break;
}
/*
* The child: starting here, we don't have to care about
* handling PAM issues if we exit, the parent will do the
* job when we exit.
*
* Destroy environment unless user has requested its preservation.
* Try to preserve TERM anyway.
*/
saved_term = getenv("TERM");
if (!pflag) {
environ = envinit;
if (saved_term)
setenv("TERM", saved_term, 0);
}
if (*pwd->pw_shell == '\0')
pwd->pw_shell = _PATH_BSHELL;
shell = login_getcapstr(lc, "shell", pwd->pw_shell, pwd->pw_shell);
if (*shell == '\0')
shell = pwd->pw_shell;
if ((pwd->pw_shell = strdup(shell)) == NULL) {
syslog(LOG_ERR, "Cannot alloc mem");
exit(EXIT_FAILURE);
}
(void)setenv("HOME", pwd->pw_dir, 1);
(void)setenv("SHELL", pwd->pw_shell, 1);
if (term[0] == '\0') {
char *tt = (char *)stypeof(tty);
if (tt == NULL)
tt = login_getcapstr(lc, "term", NULL, NULL);
/* unknown term -> "su" */
(void)strlcpy(term, tt != NULL ? tt : "su", sizeof(term));
}
(void)setenv("TERM", term, 0);
(void)setenv("LOGNAME", pwd->pw_name, 1);
(void)setenv("USER", pwd->pw_name, 1);
/*
* Add PAM environement
*/
if ((pamenv = pam_getenvlist(pamh)) != NULL) {
char **envitem;
for (envitem = pamenv; *envitem; envitem++) {
putenv(*envitem);
free(*envitem);
}
free(pamenv);
}
/* This drops root privs */
if (setusercontext(lc, pwd, pwd->pw_uid,
(LOGIN_SETALL & ~LOGIN_SETLOGIN)) != 0) {
syslog(LOG_ERR, "setusercontext failed");
exit(EXIT_FAILURE);
}
if (!quietlog) {
char *fname;
fname = login_getcapstr(lc, "copyright", NULL, NULL);
if (fname != NULL && access(fname, F_OK) == 0)
motd(fname);
else
(void)printf("%s", copyrightstr);
fname = login_getcapstr(lc, "welcome", NULL, NULL);
if (fname == NULL || access(fname, F_OK) != 0)
fname = _PATH_MOTDFILE;
motd(fname);
(void)snprintf(tbuf,
sizeof(tbuf), "%s/%s", _PATH_MAILDIR, pwd->pw_name);
if (stat(tbuf, &st) == 0 && st.st_size != 0)
(void)printf("You have %smail.\n",
(st.st_mtime > st.st_atime) ? "new " : "");
}
login_close(lc);
tbuf[0] = '-';
(void)strlcpy(tbuf + 1, (p = strrchr(pwd->pw_shell, '/')) ?
p + 1 : pwd->pw_shell, sizeof(tbuf) - 1);
(void)signal(SIGABRT, oabrt);
(void)signal(SIGALRM, oalrm);
(void)signal(SIGINT, oint);
(void)signal(SIGQUIT, oquit);
(void)signal(SIGTSTP, SIG_IGN);
execlp(pwd->pw_shell, tbuf, NULL);
err(EXIT_FAILURE, "%s", pwd->pw_shell);
}
#define NBUFSIZ (MAXLOGNAME + 1)
void
getloginname(void)
{
int ch;
char *p;
static char nbuf[NBUFSIZ];
for (;;) {
(void)printf("login: ");
for (p = nbuf; (ch = getchar()) != '\n'; ) {
if (ch == EOF) {
badlogin(username);
exit(EXIT_FAILURE);
}
if (p < nbuf + (NBUFSIZ - 1))
*p++ = ch;
}
if (p > nbuf) {
if (nbuf[0] == '-')
(void)fprintf(stderr,
"login names may not start with '-'.\n");
else {
*p = '\0';
username = nbuf;
break;
}
}
}
}
int
rootterm(char *ttyn)
{
struct ttyent *t;
return ((t = getttynam(ttyn)) && t->ty_status & TTY_SECURE);
}
jmp_buf motdinterrupt;
void
motd(char *fname)
{
int fd, nchars;
sig_t oldint;
char tbuf[8192];
if ((fd = open(fname ? fname : _PATH_MOTDFILE, O_RDONLY, 0)) < 0)
return;
oldint = signal(SIGINT, sigint);
if (setjmp(motdinterrupt) == 0)
while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0)
(void)write(fileno(stdout), tbuf, nchars);
(void)signal(SIGINT, oldint);
(void)close(fd);
}
/* ARGSUSED */
void
sigint(int signo)
{
longjmp(motdinterrupt, 1);
}
/* ARGSUSED */
void
timedout(int signo)
{
(void)fprintf(stderr, "Login timed out after %d seconds\n", timeout);
exit(EXIT_FAILURE);
}
static void
update_db(int quietlog)
{
if (nested != NULL) {
if (hostname != NULL)
syslog(LOG_NOTICE, "%s to %s on tty %s from %s",
nested, pwd->pw_name, tty, hostname);
else
syslog(LOG_NOTICE, "%s to %s on tty %s", nested,
pwd->pw_name, tty);
}
if (hostname != NULL && have_ss == 0) {
socklen_t len = sizeof(ss);
have_ss = getpeername(STDIN_FILENO, (struct sockaddr *)&ss,
&len) != -1;
}
(void)gettimeofday(&now, NULL);
}
void
badlogin(char *name)
{
if (failures == 0)
return;
if (hostname) {
syslog(LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s",
failures, failures > 1 ? "S" : "", hostname);
syslog(LOG_AUTHPRIV|LOG_NOTICE,
"%d LOGIN FAILURE%s FROM %s, %s",
failures, failures > 1 ? "S" : "", hostname, name);
} else {
syslog(LOG_NOTICE, "%d LOGIN FAILURE%s ON %s",
failures, failures > 1 ? "S" : "", tty);
syslog(LOG_AUTHPRIV|LOG_NOTICE,
"%d LOGIN FAILURE%s ON %s, %s",
failures, failures > 1 ? "S" : "", tty, name);
}
}
const char *
stypeof(const char *ttyid)
{
struct ttyent *t;
return (ttyid && (t = getttynam(ttyid)) ? t->ty_type : NULL);
}
void
sleepexit(int eval)
{
(void)sleep(5);
exit(eval);
}
void
decode_ss(const char *arg)
{
struct sockaddr_storage *ssp;
size_t len = strlen(arg);
if (len > sizeof(*ssp) * 4 + 1 || len < sizeof(*ssp))
errx(EXIT_FAILURE, "Bad argument");
if ((ssp = malloc(len)) == NULL)
err(EXIT_FAILURE, NULL);
if (strunvis((char *)ssp, arg) != sizeof(*ssp))
errx(EXIT_FAILURE, "Decoding error");
(void)memcpy(&ss, ssp, sizeof(ss));
have_ss = 1;
free(ssp);
}
void
usage(void)
{
(void)fprintf(stderr,
"Usage: %s [-fp] [-a address] [-h hostname] [username]\n",
getprogname());
exit(EXIT_FAILURE);
}