void
doit(struct sockaddr *fromp)
{
extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */
struct passwd *pwd;
u_short port;
fd_set ready, readfrom;
int cc, fd, nfd, pv[2], pid, s;
int one = 1;
const char *cp, *errorstr;
char sig, buf[BUFSIZ];
char *cmdbuf, luser[16], ruser[16];
char rhost[2 * MAXHOSTNAMELEN + 1];
char numericname[INET6_ADDRSTRLEN];
int af, srcport;
int maxcmdlen;
#ifndef __APPLE__
login_cap_t *lc;
#else
struct hostent *hp;
char *hostname, *errorhost = NULL;
#endif
maxcmdlen = (int)sysconf(_SC_ARG_MAX);
if (maxcmdlen <= 0 || (cmdbuf = malloc(maxcmdlen)) == NULL)
exit(1);
#if defined(KERBEROS)
AUTH_DAT *kdata = (AUTH_DAT *) NULL;
KTEXT ticket = (KTEXT) NULL;
char instance[INST_SZ], version[VERSION_SIZE];
struct sockaddr_in fromaddr;
int rc;
long authopts;
int pv1[2], pv2[2];
fd_set wready, writeto;
fromaddr = *fromp;
#endif /* KERBEROS */
(void) signal(SIGINT, SIG_DFL);
(void) signal(SIGQUIT, SIG_DFL);
(void) signal(SIGTERM, SIG_DFL);
af = fromp->sa_family;
srcport = ntohs(*((in_port_t *)&fromp->sa_data));
if (af == AF_INET) {
inet_ntop(af, &((struct sockaddr_in *)fromp)->sin_addr,
numericname, sizeof numericname);
} else if (af == AF_INET6) {
inet_ntop(af, &((struct sockaddr_in6 *)fromp)->sin6_addr,
numericname, sizeof numericname);
} else {
syslog(LOG_ERR, "malformed \"from\" address (af %d)", af);
exit(1);
}
#ifdef IP_OPTIONS
if (af == AF_INET) {
u_char optbuf[BUFSIZ/3];
socklen_t optsize = sizeof(optbuf), ipproto, i;
struct protoent *ip;
if ((ip = getprotobyname("ip")) != NULL)
ipproto = ip->p_proto;
else
ipproto = IPPROTO_IP;
if (!getsockopt(0, ipproto, IP_OPTIONS, optbuf, &optsize) &&
optsize != 0) {
for (i = 0; i < optsize; ) {
u_char c = optbuf[i];
if (c == IPOPT_LSRR || c == IPOPT_SSRR) {
syslog(LOG_NOTICE,
"connection refused from %s with IP option %s",
numericname,
c == IPOPT_LSRR ? "LSRR" : "SSRR");
exit(1);
}
if (c == IPOPT_EOL)
break;
i += (c == IPOPT_NOP) ? 1 : optbuf[i+1];
}
}
}
#endif
#if defined(KERBEROS)
if (!use_kerberos)
#endif
if (srcport >= IPPORT_RESERVED ||
srcport < IPPORT_RESERVED/2) {
syslog(LOG_NOTICE|LOG_AUTH,
"connection from %s on illegal port %u",
numericname,
srcport);
exit(1);
}
(void) alarm(60);
port = 0;
s = 0; /* not set or used if port == 0 */
for (;;) {
char c;
if ((cc = read(STDIN_FILENO, &c, 1)) != 1) {
if (cc < 0)
syslog(LOG_NOTICE, "read: %m");
shutdown(0, SHUT_RDWR);
exit(1);
}
if (c == 0)
break;
port = port * 10 + c - '0';
}
(void) alarm(0);
if (port != 0) {
int lport = IPPORT_RESERVED - 1;
s = rresvport_af(&lport, af);
if (s < 0) {
syslog(LOG_ERR, "can't get stderr port: %m");
exit(1);
}
#if defined(KERBEROS)
if (!use_kerberos)
#endif
if (port >= IPPORT_RESERVED ||
port < IPPORT_RESERVED/2) {
syslog(LOG_NOTICE|LOG_AUTH,
"2nd socket from %s on unreserved port %u",
numericname,
port);
exit(1);
}
*((in_port_t *)&fromp->sa_data) = htons(port);
if (connect(s, fromp, fromp->sa_len) < 0) {
syslog(LOG_INFO, "connect second port %d: %m", port);
exit(1);
}
}
#if defined(KERBEROS)
if (vacuous) {
error("rshd: remote host requires Kerberos authentication\n");
exit(1);
}
#endif
errorstr = NULL;
#ifndef __APPLE__
realhostname_sa(rhost, sizeof(rhost) - 1, fromp, fromp->sa_len);
rhost[sizeof(rhost) - 1] = '\0';
/* XXX truncation! */
#else
errorstr = NULL;
hp = gethostbyaddr((char *)&((struct sockaddr_in *)fromp)->sin_addr, sizeof (struct in_addr),
((struct sockaddr_in *)fromp)->sin_family);
if (hp) {
/*
* If name returned by gethostbyaddr is in our domain,
* attempt to verify that we haven't been fooled by someone
* in a remote net; look up the name and check that this
* address corresponds to the name.
*/
hostname = hp->h_name;
#if defined(KERBEROS)
if (!use_kerberos)
#endif
if (check_all || local_domain(hp->h_name)) {
strncpy(rhost, hp->h_name, sizeof(rhost) - 1);
rhost[sizeof(rhost) - 1] = 0;
errorhost = rhost;
hp = gethostbyname(rhost);
if (hp == NULL) {
syslog(LOG_INFO,
"Couldn't look up address for %s",
rhost);
errorstr =
"Couldn't look up address for your host (%s)\n";
hostname = inet_ntoa(((struct sockaddr_in *)fromp)->sin_addr);
} else for (; ; hp->h_addr_list++) {
if (hp->h_addr_list[0] == NULL) {
syslog(LOG_NOTICE,
"Host addr %s not listed for host %s",
inet_ntoa(((struct sockaddr_in *)fromp)->sin_addr),
hp->h_name);
errorstr =
"Host address mismatch for %s\n";
hostname = inet_ntoa(((struct sockaddr_in *)fromp)->sin_addr);
break;
}
if (!bcmp(hp->h_addr_list[0],
(caddr_t)&((struct sockaddr_in *)fromp)->sin_addr,
sizeof(((struct sockaddr_in *)fromp)->sin_addr))) {
hostname = hp->h_name;
break;
}
}
}
} else
errorhost = hostname = inet_ntoa(((struct sockaddr_in *)fromp)->sin_addr);
#if defined(KERBEROS)
if (use_kerberos) {
kdata = (AUTH_DAT *) authbuf;
ticket = (KTEXT) tickbuf;
authopts = 0L;
strcpy(instance, "*");
version[VERSION_SIZE - 1] = '\0';
#if defined(CRYPT)
if (doencrypt) {
struct sockaddr_in local_addr;
rc = sizeof(local_addr);
if (getsockname(0, (struct sockaddr *)&local_addr,
&rc) < 0) {
syslog(LOG_ERR, "getsockname: %m");
error("rshd: getsockname: %m");
exit(1);
}
authopts = KOPT_DO_MUTUAL;
rc = krb_recvauth(authopts, 0, ticket,
"rcmd", instance, &fromaddr,
&local_addr, kdata, "", schedule,
version);
des_set_key(kdata->session, schedule);
} else
#endif /* CRYPT */
rc = krb_recvauth(authopts, 0, ticket, "rcmd",
instance, &fromaddr,
(struct sockaddr_in *) 0,
kdata, "", (bit_64 *) 0, version);
if (rc != KSUCCESS) {
error("Kerberos authentication failure: %s\n",
krb_err_txt[rc]);
exit(1);
}
} else
#endif /* KERBEROS */
#endif
(void) alarm(60);
getstr(ruser, sizeof(ruser), "ruser");
getstr(luser, sizeof(luser), "luser");
getstr(cmdbuf, maxcmdlen, "command");
(void) alarm(0);
#if !TARGET_OS_EMBEDDED
pam_err = pam_start("rshd", luser, &pamc, &pamh);
if (pam_err != PAM_SUCCESS) {
syslog(LOG_ERR|LOG_AUTH, "pam_start(): %s",
pam_strerror(pamh, pam_err));
rshd_errx(1, "Login incorrect.");
}
if ((pam_err = pam_set_item(pamh, PAM_RUSER, ruser)) != PAM_SUCCESS ||
(pam_err = pam_set_item(pamh, PAM_RHOST, rhost) != PAM_SUCCESS)) {
syslog(LOG_ERR|LOG_AUTH, "pam_set_item(): %s",
pam_strerror(pamh, pam_err));
rshd_errx(1, "Login incorrect.");
}
pam_err = pam_authenticate(pamh, 0);
if (pam_err == PAM_SUCCESS) {
if ((pam_err = pam_get_user(pamh, &cp, NULL)) == PAM_SUCCESS) {
strncpy(luser, cp, sizeof(luser));
luser[sizeof(luser) - 1] = '\0';
/* XXX truncation! */
}
pam_err = pam_acct_mgmt(pamh, 0);
}
if (pam_err != PAM_SUCCESS) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: permission denied (%s). cmd='%.80s'",
ruser, rhost, luser, pam_strerror(pamh, pam_err), cmdbuf);
rshd_errx(1, "Login incorrect.");
}
#endif
setpwent();
pwd = getpwnam(luser);
if (pwd == NULL) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: unknown login. cmd='%.80s'",
ruser, rhost, luser, cmdbuf);
if (errorstr == NULL)
errorstr = "Login incorrect.";
rshd_errx(1, errorstr, rhost);
}
#ifndef __APPLE__
lc = login_getpwclass(pwd);
if (pwd->pw_uid)
auth_checknologin(lc);
#endif
if (chdir(pwd->pw_dir) < 0) {
if (chdir("/") < 0 ||
#ifndef __APPLE__
login_getcapbool(lc, "requirehome", !!pwd->pw_uid)) {
#else
0) {
#endif /* __APPLE__ */
#ifdef notdef
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: no home directory. cmd='%.80s'",
ruser, rhost, luser, cmdbuf);
rshd_errx(0, "No remote home directory.");
#endif
}
pwd->pw_dir = slash;
}
#if defined(KERBEROS)
if (use_kerberos) {
if (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0') {
if (kuserok(kdata, luser) != 0) {
syslog(LOG_INFO|LOG_AUTH,
"Kerberos rsh denied to %s.%s@%s",
kdata->pname, kdata->pinst, kdata->prealm);
error("Permission denied.\n");
exit(1);
}
}
} else
#endif
#ifdef __APPLE__
if (errorstr ||
(pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' &&
iruserok(((struct sockaddr_in *)fromp)->sin_addr.s_addr,
#if TARGET_OS_EMBEDDED
// rdar://problem/5381734
0,
#else
pwd->pw_uid == 0,
#endif
ruser, luser) < 0)) {
if (__rcmd_errstr)
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: permission denied (%s). cmd='%.80s'",
ruser, rhost, luser, __rcmd_errstr,
cmdbuf);
else
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: permission denied. cmd='%.80s'",
ruser, rhost, luser, cmdbuf);
if (errorstr == NULL)
errorstr = "Permission denied.";
rshd_errx(1, errorstr, errorhost);
}
if (pwd->pw_uid && !access(_PATH_NOLOGIN, F_OK)) {
rshd_errx(1, "Logins currently disabled.");
}
#else
if (lc != NULL && fromp->sa_family == AF_INET) { /*XXX*/
char remote_ip[MAXHOSTNAMELEN];
strncpy(remote_ip, numericname,
sizeof(remote_ip) - 1);
remote_ip[sizeof(remote_ip) - 1] = 0;
/* XXX truncation! */
if (!auth_hostok(lc, rhost, remote_ip)) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: permission denied (%s). cmd='%.80s'",
ruser, rhost, luser, __rcmd_errstr,
cmdbuf);
rshd_errx(1, "Login incorrect.");
}
if (!auth_timeok(lc, time(NULL)))
rshd_errx(1, "Logins not available right now");
}
/*
* PAM modules might add supplementary groups in
* pam_setcred(), so initialize them first.
* But we need to open the session as root.
*/
if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETGROUP) != 0) {
syslog(LOG_ERR, "setusercontext: %m");
exit(1);
}
#endif /* !__APPLE__ */
#if !TARGET_OS_EMBEDDED
if ((pam_err = pam_open_session(pamh, 0)) != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_open_session: %s", pam_strerror(pamh, pam_err));
} else if ((pam_err = pam_setcred(pamh, PAM_ESTABLISH_CRED)) != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, pam_err));
}
#endif
(void) write(STDERR_FILENO, "\0", 1);
sent_null = 1;
if (port) {
if (pipe(pv) < 0)
rshd_errx(1, "Can't make pipe.");
#if defined(KERBEROS) && defined(CRYPT)
if (doencrypt) {
if (pipe(pv1) < 0)
rshd_errx(1, "Can't make 2nd pipe.");
if (pipe(pv2) < 0)
rshd_errx(1, "Can't make 3rd pipe.");
}
#endif /* KERBEROS && CRYPT */
pid = fork();
if (pid == -1)
rshd_errx(1, "Can't fork; try again.");
if (pid) {
#if defined(KERBEROS) && defined(CRYPT)
if (doencrypt) {
static char msg[] = SECURE_MESSAGE;
(void) close(pv1[1]);
(void) close(pv2[1]);
des_write(s, msg, sizeof(msg) - 1);
} else
#endif /* KERBEROS && CRYPT */
(void) close(0);
(void) close(1);
(void) close(2);
(void) close(pv[1]);
FD_ZERO(&readfrom);
FD_SET(s, &readfrom);
FD_SET(pv[0], &readfrom);
if (pv[0] > s)
nfd = pv[0];
else
nfd = s;
#if defined(KERBEROS) && defined(CRYPT)
if (doencrypt) {
FD_ZERO(&writeto);
FD_SET(pv2[0], &writeto);
FD_SET(pv1[0], &readfrom);
nfd = MAX(nfd, pv2[0]);
nfd = MAX(nfd, pv1[0]);
} else
#endif /* KERBEROS && CRYPT */
ioctl(pv[0], FIONBIO, (char *)&one);
/* should set s nbio! */
nfd++;
do {
ready = readfrom;
#if defined(KERBEROS) && defined(CRYPT)
if (doencrypt) {
wready = writeto;
if (select(nfd, &ready,
&wready, (fd_set *) 0,
(struct timeval *) 0) < 0)
break;
} else
#endif /* KERBEROS && CRYPT */
if (select(nfd, &ready, (fd_set *)0,
(fd_set *)0, (struct timeval *)0) < 0)
break;
if (FD_ISSET(s, &ready)) {
int ret;
#if defined(KERBEROS) && defined(CRYPT)
if (doencrypt)
ret = des_read(s, &sig, 1);
else
#endif /* KERBEROS && CRYPT */
ret = read(s, &sig, 1);
if (ret <= 0)
FD_CLR(s, &readfrom);
else
killpg(pid, sig);
}
if (FD_ISSET(pv[0], &ready)) {
errno = 0;
cc = read(pv[0], buf, sizeof(buf));
if (cc <= 0) {
shutdown(s, SHUT_RDWR);
FD_CLR(pv[0], &readfrom);
} else {
#if defined(KERBEROS) && defined(CRYPT)
if (doencrypt)
(void)
des_write(s, buf, cc);
else
#endif /* KERBEROS && CRYPT */
(void)write(s, buf, cc);
}
}
#if defined(KERBEROS) && defined(CRYPT)
if (doencrypt && FD_ISSET(pv1[0], &ready)) {
errno = 0;
cc = read(pv1[0], buf, sizeof(buf));
if (cc <= 0) {
shutdown(pv1[0], 1+1);
FD_CLR(pv1[0], &readfrom);
} else
(void) des_write(STDOUT_FILENO,
buf, cc);
}
if (doencrypt && FD_ISSET(pv2[0], &wready)) {
errno = 0;
cc = des_read(STDIN_FILENO,
buf, sizeof(buf));
if (cc <= 0) {
shutdown(pv2[0], 1+1);
FD_CLR(pv2[0], &writeto);
} else
(void) write(pv2[0], buf, cc);
}
#endif /* KERBEROS && CRYPT */
} while (FD_ISSET(s, &readfrom) ||
#if defined(KERBEROS) && defined(CRYPT)
(doencrypt && FD_ISSET(pv1[0], &readfrom)) ||
#endif /* KERBEROS && CRYPT */
FD_ISSET(pv[0], &readfrom));
#if !TARGET_OS_EMBEDDED
PAM_END;
#endif
exit(0);
}
#ifdef __APPLE__
// rdar://problem/4485794
setpgid(0, getpid());
#endif
(void) close(s);
(void) close(pv[0]);
#if defined(KERBEROS) && defined(CRYPT)
if (doencrypt) {
close(pv1[0]); close(pv2[0]);
dup2(pv1[1], 1);
dup2(pv2[1], 0);
close(pv1[1]);
close(pv2[1]);
}
#endif /* KERBEROS && CRYPT */
dup2(pv[1], 2);
close(pv[1]);
}
#ifndef __APPLE__
else {
pid = fork();
if (pid == -1)
rshd_errx(1, "Can't fork; try again.");
if (pid) {
/* Parent. */
while (wait(NULL) > 0 || errno == EINTR)
/* nothing */ ;
PAM_END;
exit(0);
}
}
#endif
for (fd = getdtablesize(); fd > 2; fd--) {
#ifdef __APPLE__
(void) fcntl(fd, F_SETFD, FD_CLOEXEC);
#else
(void) close(fd);
#endif
}
if (setsid() == -1)
syslog(LOG_ERR, "setsid() failed: %m");
if (setlogin(pwd->pw_name) < 0)
syslog(LOG_ERR, "setlogin() failed: %m");
if (*pwd->pw_shell == '\0')
pwd->pw_shell = bshell;
#ifdef __APPLE__
(void) setgid((gid_t)pwd->pw_gid);
initgroups(pwd->pw_name, pwd->pw_gid);
(void) setuid((uid_t)pwd->pw_uid);
environ = envinit;
strncat(homedir, pwd->pw_dir, sizeof(homedir)-6);
strcat(path, _PATH_DEFPATH);
strncat(shell, pwd->pw_shell, sizeof(shell)-7);
strncat(username, pwd->pw_name, sizeof(username)-6);
#endif
#if !TARGET_OS_EMBEDDED
(void) pam_setenv(pamh, "HOME", pwd->pw_dir, 1);
(void) pam_setenv(pamh, "SHELL", pwd->pw_shell, 1);
(void) pam_setenv(pamh, "USER", pwd->pw_name, 1);
(void) pam_setenv(pamh, "PATH", _PATH_DEFPATH, 1);
environ = pam_getenvlist(pamh);
(void) pam_end(pamh, pam_err);
#endif
cp = strrchr(pwd->pw_shell, '/');
if (cp)
cp++;
else
cp = pwd->pw_shell;
#ifndef __APPLE__
if (setusercontext(lc, pwd, pwd->pw_uid,
LOGIN_SETALL & ~LOGIN_SETGROUP) < 0) {
syslog(LOG_ERR, "setusercontext(): %m");
exit(1);
}
login_close(lc);
#endif
endpwent();
if (log_success || pwd->pw_uid == 0) {
#if defined(KERBEROS)
if (use_kerberos)
syslog(LOG_INFO|LOG_AUTH,
"Kerberos shell from %s.%s@%s on %s as %s, cmd='%.80s'",
kdata->pname, kdata->pinst, kdata->prealm,
hostname, luser, cmdbuf);
else
#endif /* KERBEROS */
syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'",
ruser, rhost, luser, cmdbuf);
}
execl(pwd->pw_shell, cp, "-c", cmdbuf, (char *)NULL);
err(1, "%s", pwd->pw_shell);
exit(1);
}
/*ARGSUSED*/
static void
input_userauth_request(int type, u_int32_t seq, void *ctxt)
{
Authctxt *authctxt = ctxt;
Authmethod *m = NULL;
char *user, *service, *method, *style = NULL;
int authenticated = 0;
#ifdef HAVE_LOGIN_CAP
login_cap_t *lc;
const char *from_host, *from_ip;
from_host = get_canonical_hostname(options.use_dns);
from_ip = get_remote_ipaddr();
#endif
if (authctxt == NULL)
fatal("input_userauth_request: no authctxt");
user = packet_get_cstring(NULL);
service = packet_get_cstring(NULL);
method = packet_get_cstring(NULL);
debug("userauth-request for user %s service %s method %s", user, service, method);
debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);
if ((style = strchr(user, ':')) != NULL)
*style++ = 0;
if (authctxt->attempt++ == 0) {
/* setup auth context */
authctxt->pw = PRIVSEP(getpwnamallow(user));
authctxt->user = xstrdup(user);
if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
authctxt->valid = 1;
debug2("input_userauth_request: setting up authctxt for %s", user);
} else {
logit("input_userauth_request: invalid user %s", user);
authctxt->pw = fakepw();
#ifdef SSH_AUDIT_EVENTS
PRIVSEP(audit_event(SSH_INVALID_USER));
#endif
}
#ifdef USE_PAM
if (options.use_pam)
PRIVSEP(start_pam(authctxt));
#endif
setproctitle("%s%s", authctxt->valid ? user : "******",
use_privsep ? " [net]" : "");
authctxt->service = xstrdup(service);
authctxt->style = style ? xstrdup(style) : NULL;
if (use_privsep)
mm_inform_authserv(service, style);
userauth_banner();
if (auth2_setup_methods_lists(authctxt) != 0)
packet_disconnect("no authentication methods enabled");
} else if (strcmp(user, authctxt->user) != 0 ||
strcmp(service, authctxt->service) != 0) {
packet_disconnect("Change of username or service not allowed: "
"(%s,%s) -> (%s,%s)",
authctxt->user, authctxt->service, user, service);
}
#ifdef HAVE_LOGIN_CAP
if (authctxt->pw != NULL) {
lc = login_getpwclass(authctxt->pw);
if (lc == NULL)
lc = login_getclassbyname(NULL, authctxt->pw);
if (!auth_hostok(lc, from_host, from_ip)) {
logit("Denied connection for %.200s from %.200s [%.200s].",
authctxt->pw->pw_name, from_host, from_ip);
packet_disconnect("Sorry, you are not allowed to connect.");
}
if (!auth_timeok(lc, time(NULL))) {
logit("LOGIN %.200s REFUSED (TIME) FROM %.200s",
authctxt->pw->pw_name, from_host);
packet_disconnect("Logins not available right now.");
}
login_close(lc);
lc = NULL;
}
#endif /* HAVE_LOGIN_CAP */
/* reset state */
auth2_challenge_stop(authctxt);
#ifdef GSSAPI
/* XXX move to auth2_gssapi_stop() */
dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
#endif
authctxt->postponed = 0;
authctxt->server_caused_failure = 0;
/* try to authenticate user */
m = authmethod_lookup(authctxt, method);
if (m != NULL && authctxt->failures < options.max_authtries) {
debug2("input_userauth_request: try method %s", method);
authenticated = m->userauth(authctxt);
}
userauth_finish(authctxt, authenticated, method, NULL);
free(service);
free(user);
free(method);
}
void
doit(struct sockaddr *fromp)
{
extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */
struct passwd *pwd;
u_short port;
fd_set ready, readfrom;
int cc, fd, nfd, pv[2], pid, s;
int one = 1;
const char *cp, *errorstr;
char sig, buf[BUFSIZ];
char *cmdbuf, luser[16], ruser[16];
char rhost[2 * MAXHOSTNAMELEN + 1];
char numericname[INET6_ADDRSTRLEN];
int af, srcport;
int maxcmdlen;
login_cap_t *lc;
maxcmdlen = (int)sysconf(_SC_ARG_MAX);
if (maxcmdlen <= 0 || (cmdbuf = malloc(maxcmdlen)) == NULL)
exit(1);
(void) signal(SIGINT, SIG_DFL);
(void) signal(SIGQUIT, SIG_DFL);
(void) signal(SIGTERM, SIG_DFL);
af = fromp->sa_family;
srcport = ntohs(*((in_port_t *)&fromp->sa_data));
if (af == AF_INET) {
inet_ntop(af, &((struct sockaddr_in *)fromp)->sin_addr,
numericname, sizeof numericname);
} else if (af == AF_INET6) {
inet_ntop(af, &((struct sockaddr_in6 *)fromp)->sin6_addr,
numericname, sizeof numericname);
} else {
syslog(LOG_ERR, "malformed \"from\" address (af %d)", af);
exit(1);
}
#ifdef IP_OPTIONS
if (af == AF_INET) {
u_char optbuf[BUFSIZ/3];
socklen_t optsize = sizeof(optbuf), ipproto, i;
struct protoent *ip;
if ((ip = getprotobyname("ip")) != NULL)
ipproto = ip->p_proto;
else
ipproto = IPPROTO_IP;
if (!getsockopt(0, ipproto, IP_OPTIONS, optbuf, &optsize) &&
optsize != 0) {
for (i = 0; i < optsize; ) {
u_char c = optbuf[i];
if (c == IPOPT_LSRR || c == IPOPT_SSRR) {
syslog(LOG_NOTICE,
"connection refused from %s with IP option %s",
numericname,
c == IPOPT_LSRR ? "LSRR" : "SSRR");
exit(1);
}
if (c == IPOPT_EOL)
break;
i += (c == IPOPT_NOP) ? 1 : optbuf[i+1];
}
}
}
#endif
if (srcport >= IPPORT_RESERVED ||
srcport < IPPORT_RESERVED/2) {
syslog(LOG_NOTICE|LOG_AUTH,
"connection from %s on illegal port %u",
numericname,
srcport);
exit(1);
}
(void) alarm(60);
port = 0;
s = 0; /* not set or used if port == 0 */
for (;;) {
char c;
if ((cc = read(STDIN_FILENO, &c, 1)) != 1) {
if (cc < 0)
syslog(LOG_NOTICE, "read: %m");
shutdown(0, SHUT_RDWR);
exit(1);
}
if (c == 0)
break;
port = port * 10 + c - '0';
}
(void) alarm(0);
if (port != 0) {
int lport = IPPORT_RESERVED - 1;
s = rresvport_af(&lport, af);
if (s < 0) {
syslog(LOG_ERR, "can't get stderr port: %m");
exit(1);
}
if (port >= IPPORT_RESERVED ||
port < IPPORT_RESERVED/2) {
syslog(LOG_NOTICE|LOG_AUTH,
"2nd socket from %s on unreserved port %u",
numericname,
port);
exit(1);
}
*((in_port_t *)&fromp->sa_data) = htons(port);
if (connect(s, fromp, fromp->sa_len) < 0) {
syslog(LOG_INFO, "connect second port %d: %m", port);
exit(1);
}
}
errorstr = NULL;
realhostname_sa(rhost, sizeof(rhost) - 1, fromp, fromp->sa_len);
rhost[sizeof(rhost) - 1] = '\0';
/* XXX truncation! */
(void) alarm(60);
getstr(ruser, sizeof(ruser), "ruser");
getstr(luser, sizeof(luser), "luser");
getstr(cmdbuf, maxcmdlen, "command");
(void) alarm(0);
pam_err = pam_start("rsh", luser, &pamc, &pamh);
if (pam_err != PAM_SUCCESS) {
syslog(LOG_ERR|LOG_AUTH, "pam_start(): %s",
pam_strerror(pamh, pam_err));
rshd_errx(1, "Login incorrect.");
}
if ((pam_err = pam_set_item(pamh, PAM_RUSER, ruser)) != PAM_SUCCESS ||
(pam_err = pam_set_item(pamh, PAM_RHOST, rhost)) != PAM_SUCCESS) {
syslog(LOG_ERR|LOG_AUTH, "pam_set_item(): %s",
pam_strerror(pamh, pam_err));
rshd_errx(1, "Login incorrect.");
}
pam_err = pam_authenticate(pamh, 0);
if (pam_err == PAM_SUCCESS) {
if ((pam_err = pam_get_user(pamh, &cp, NULL)) == PAM_SUCCESS) {
strncpy(luser, cp, sizeof(luser));
luser[sizeof(luser) - 1] = '\0';
/* XXX truncation! */
}
pam_err = pam_acct_mgmt(pamh, 0);
}
if (pam_err != PAM_SUCCESS) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: permission denied (%s). cmd='%.80s'",
ruser, rhost, luser, pam_strerror(pamh, pam_err), cmdbuf);
rshd_errx(1, "Login incorrect.");
}
setpwent();
pwd = getpwnam(luser);
if (pwd == NULL) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: unknown login. cmd='%.80s'",
ruser, rhost, luser, cmdbuf);
if (errorstr == NULL)
errorstr = "Login incorrect.";
rshd_errx(1, errorstr, rhost);
}
lc = login_getpwclass(pwd);
if (pwd->pw_uid)
auth_checknologin(lc);
if (chdir(pwd->pw_dir) < 0) {
if (chdir("/") < 0 ||
login_getcapbool(lc, "requirehome", !!pwd->pw_uid)) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: no home directory. cmd='%.80s'",
ruser, rhost, luser, cmdbuf);
rshd_errx(0, "No remote home directory.");
}
pwd->pw_dir = slash;
}
if (lc != NULL && fromp->sa_family == AF_INET) { /*XXX*/
char remote_ip[MAXHOSTNAMELEN];
strncpy(remote_ip, numericname,
sizeof(remote_ip) - 1);
remote_ip[sizeof(remote_ip) - 1] = 0;
/* XXX truncation! */
if (!auth_hostok(lc, rhost, remote_ip)) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: permission denied (%s). cmd='%.80s'",
ruser, rhost, luser, __rcmd_errstr,
cmdbuf);
rshd_errx(1, "Login incorrect.");
}
if (!auth_timeok(lc, time(NULL)))
rshd_errx(1, "Logins not available right now");
}
/*
* PAM modules might add supplementary groups in
* pam_setcred(), so initialize them first.
* But we need to open the session as root.
*/
if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETGROUP) != 0) {
syslog(LOG_ERR, "setusercontext: %m");
exit(1);
}
if ((pam_err = pam_open_session(pamh, 0)) != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_open_session: %s", pam_strerror(pamh, pam_err));
} else if ((pam_err = pam_setcred(pamh, PAM_ESTABLISH_CRED)) != PAM_SUCCESS) {
syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, pam_err));
}
(void) write(STDERR_FILENO, "\0", 1);
sent_null = 1;
if (port) {
if (pipe(pv) < 0)
rshd_errx(1, "Can't make pipe.");
pid = fork();
if (pid == -1)
rshd_errx(1, "Can't fork; try again.");
if (pid) {
(void) close(0);
(void) close(1);
(void) close(2);
(void) close(pv[1]);
FD_ZERO(&readfrom);
FD_SET(s, &readfrom);
FD_SET(pv[0], &readfrom);
if (pv[0] > s)
nfd = pv[0];
else
nfd = s;
ioctl(pv[0], FIONBIO, (char *)&one);
/* should set s nbio! */
nfd++;
do {
ready = readfrom;
if (select(nfd, &ready, (fd_set *)0,
(fd_set *)0, (struct timeval *)0) < 0)
break;
if (FD_ISSET(s, &ready)) {
int ret;
ret = read(s, &sig, 1);
if (ret <= 0)
FD_CLR(s, &readfrom);
else
killpg(pid, sig);
}
if (FD_ISSET(pv[0], &ready)) {
errno = 0;
cc = read(pv[0], buf, sizeof(buf));
if (cc <= 0) {
shutdown(s, SHUT_RDWR);
FD_CLR(pv[0], &readfrom);
} else {
(void)write(s, buf, cc);
}
}
} while (FD_ISSET(s, &readfrom) ||
FD_ISSET(pv[0], &readfrom));
PAM_END;
exit(0);
}
(void) close(s);
(void) close(pv[0]);
dup2(pv[1], 2);
close(pv[1]);
}
else {
pid = fork();
if (pid == -1)
rshd_errx(1, "Can't fork; try again.");
if (pid) {
/* Parent. */
while (wait(NULL) > 0 || errno == EINTR)
/* nothing */ ;
PAM_END;
exit(0);
}
}
for (fd = getdtablesize(); fd > 2; fd--)
(void) close(fd);
if (setsid() == -1)
syslog(LOG_ERR, "setsid() failed: %m");
if (setlogin(pwd->pw_name) < 0)
syslog(LOG_ERR, "setlogin() failed: %m");
if (*pwd->pw_shell == '\0')
pwd->pw_shell = bshell;
(void) pam_setenv(pamh, "HOME", pwd->pw_dir, 1);
(void) pam_setenv(pamh, "SHELL", pwd->pw_shell, 1);
(void) pam_setenv(pamh, "USER", pwd->pw_name, 1);
(void) pam_setenv(pamh, "PATH", _PATH_DEFPATH, 1);
environ = pam_getenvlist(pamh);
(void) pam_end(pamh, pam_err);
cp = strrchr(pwd->pw_shell, '/');
if (cp)
cp++;
else
cp = pwd->pw_shell;
if (setusercontext(lc, pwd, pwd->pw_uid,
LOGIN_SETALL & ~LOGIN_SETGROUP) < 0) {
syslog(LOG_ERR, "setusercontext(): %m");
exit(1);
}
login_close(lc);
endpwent();
if (log_success || pwd->pw_uid == 0) {
syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'",
ruser, rhost, luser, cmdbuf);
}
execl(pwd->pw_shell, cp, "-c", cmdbuf, (char *)NULL);
err(1, "%s", pwd->pw_shell);
exit(1);
}
