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);
}
main()
{
struct sockaddr_in foreign;
int foreign_len = sizeof(foreign);
int rval, more;
static char name[] = "kpasswdd";
static struct rlimit rl = { 0, 0 };
progname = name;
openlog("kpasswdd", LOG_CONS | LOG_PID, LOG_AUTH);
signal(SIGHUP, SIG_IGN);
signal(SIGINT, SIG_IGN);
signal(SIGTSTP, SIG_IGN);
if(setrlimit(RLIMIT_CORE, &rl) < 0) {
syslog(LOG_ERR, "setrlimit: %m");
exit(1);
}
if(getpeername(0, &foreign, &foreign_len) < 0) {
syslog(LOG_ERR,"getpeername: %m");
exit(1);
}
strcpy(inst, "*");
rval = krb_recvauth(
0L, /* !MUTUAL */
0, /* file desc */
&ticket, /* client's ticket */
SERVICE, /* expected service */
inst, /* expected instance */
&foreign, /* foreign addr */
(struct sockaddr_in *) 0,
&kdata,
"",
(bit_64 *) NULL, /* key schedule */
version
);
if(rval != KSUCCESS) {
syslog(LOG_ERR, "krb_recvauth: %s", krb_err_txt[rval]);
cleanup();
exit(1);
}
/* get master key */
if(kdb_get_master_key(0, master_key, master_key_schedule) != 0) {
syslog(LOG_ERR, "couldn't get master key");
cleanup();
exit(1);
}
mkeyversion =
kdb_get_master_key(master_key, master_key_schedule, NULL);
if(mkeyversion < 0) {
syslog(LOG_NOTICE, "couldn't verify master key");
cleanup();
exit(1);
}
/* get principal info */
rval = kerb_get_principal(
kdata.pname,
kdata.pinst,
&principal_data,
1,
&more
);
if(rval != 1 || (more != 0)) {
syslog(LOG_NOTICE, "more than 1 entry for %s.%s",
kdata.pname, kdata.pinst);
cleanup();
exit(1);
}
/* get the user's key */
bcopy(&principal_data.key_low, key, 4);
bcopy(&principal_data.key_high, ((long *) key) + 1, 4);
kdb_encrypt_key(key, key, master_key, master_key_schedule,
DECRYPT);
key_sched(key, key_schedule);
des_set_key(key, key_schedule);
/* get random key and send it over {random} Kperson */
random_key(kpwd_data.random_key);
strcpy(kpwd_data.secure_msg, SECURE_STRING);
if(des_write(0, &kpwd_data, sizeof(kpwd_data)) != sizeof(kpwd_data)) {
syslog(LOG_ERR, "error writing initial data");
cleanup();
exit(1);
}
bzero(key, sizeof(key));
bzero(key_schedule, sizeof(key_schedule));
/* now read update info: { info }Krandom */
key_sched(kpwd_data.random_key, random_sched);
des_set_key(kpwd_data.random_key, random_sched);
if(des_read(0, &ud_data, sizeof(ud_data)) != sizeof(ud_data)) {
syslog(LOG_ERR, "update aborted");
cleanup();
exit(1);
}
/* validate info string by looking at the embedded string */
if(strcmp(ud_data.secure_msg, SECURE_STRING)) {
syslog(LOG_NOTICE, "invalid update from %s",
inet_ntoa(foreign.sin_addr));
cleanup();
exit(1);
}
/* produce the new key entry in the database { key }Kmaster */
string_to_key(ud_data.pw, key);
kdb_encrypt_key(key, key,
master_key, master_key_schedule,
ENCRYPT);
bcopy(key, &principal_data.key_low, 4);
bcopy(((long *) key) + 1,
&principal_data.key_high, 4);
bzero(key, sizeof(key));
principal_data.key_version++;
if(kerb_put_principal(&principal_data, 1)) {
syslog(LOG_ERR, "couldn't write new record for %s.%s",
principal_data.name, principal_data.instance);
cleanup();
exit(1);
}
syslog(LOG_NOTICE,"wrote new password field for %s.%s from %s",
principal_data.name,
principal_data.instance,
inet_ntoa(foreign.sin_addr)
);
send_ack(0, "Update complete.\n");
cleanup();
exit(0);
}
void
doit(struct sockaddr *fromp)
{
extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */
struct addrinfo hints, *res, *res0;
int gaierror;
struct passwd *pwd;
u_short port;
in_port_t *portp;
struct pollfd pfd[4];
int cc, nfd, pv[2], s = 0, one = 1;
pid_t pid;
char *hostname, *errorstr, *errorhost = (char *) NULL;
char *cp, sig, buf[BUFSIZ];
char cmdbuf[NCARGS+1], locuser[_PW_NAME_LEN+1], remuser[_PW_NAME_LEN+1];
char remotehost[2 * MAXHOSTNAMELEN + 1];
char hostnamebuf[2 * MAXHOSTNAMELEN + 1];
char naddr[NI_MAXHOST];
char saddr[NI_MAXHOST];
char raddr[NI_MAXHOST];
char pbuf[NI_MAXSERV];
auth_session_t *as;
const int niflags = NI_NUMERICHOST | NI_NUMERICSERV;
#ifdef KERBEROS
AUTH_DAT *kdata = (AUTH_DAT *) NULL;
KTEXT ticket = (KTEXT) NULL;
char instance[INST_SZ], version[VERSION_SIZE];
struct sockaddr_storage fromaddr;
int rc;
long authopts;
#ifdef CRYPT
int pv1[2], pv2[2];
#endif
if (sizeof(fromaddr) < fromp->sa_len) {
syslog(LOG_ERR, "malformed \"from\" address (af %d)",
fromp->sa_family);
exit(1);
}
memcpy(&fromaddr, fromp, fromp->sa_len);
#endif
(void) signal(SIGINT, SIG_DFL);
(void) signal(SIGQUIT, SIG_DFL);
(void) signal(SIGTERM, SIG_DFL);
#ifdef DEBUG
{ int t = open(_PATH_TTY, 2);
if (t >= 0) {
ioctl(t, TIOCNOTTY, (char *)0);
(void) close(t);
}
}
#endif
switch (fromp->sa_family) {
case AF_INET:
portp = &((struct sockaddr_in *)fromp)->sin_port;
break;
case AF_INET6:
portp = &((struct sockaddr_in6 *)fromp)->sin6_port;
break;
default:
syslog(LOG_ERR, "malformed \"from\" address (af %d)",
fromp->sa_family);
exit(1);
}
if (getnameinfo(fromp, fromp->sa_len, naddr, sizeof(naddr),
pbuf, sizeof(pbuf), niflags) != 0) {
syslog(LOG_ERR, "malformed \"from\" address (af %d)",
fromp->sa_family);
exit(1);
}
#ifdef IP_OPTIONS
if (fromp->sa_family == AF_INET) {
struct ipoption opts;
socklen_t optsize = sizeof(opts);
int ipproto, i;
struct protoent *ip;
if ((ip = getprotobyname("ip")) != NULL)
ipproto = ip->p_proto;
else
ipproto = IPPROTO_IP;
if (!getsockopt(STDIN_FILENO, ipproto, IP_OPTIONS,
(char *)&opts, &optsize) && optsize != 0) {
for (i = 0; (void *)&opts.ipopt_list[i] - (void *)&opts <
optsize; ) {
u_char c = (u_char)opts.ipopt_list[i];
if (c == IPOPT_LSRR || c == IPOPT_SSRR)
exit(1);
if (c == IPOPT_EOL)
break;
i += (c == IPOPT_NOP) ? 1 :
(u_char)opts.ipopt_list[i+1];
}
}
}
#endif
#ifdef KERBEROS
if (!use_kerberos)
#endif
if (ntohs(*portp) >= IPPORT_RESERVED ||
ntohs(*portp) < IPPORT_RESERVED/2) {
syslog(LOG_NOTICE|LOG_AUTH,
"Connection from %s on illegal port %u",
naddr, ntohs(*portp));
exit(1);
}
(void) alarm(60);
port = 0;
for (;;) {
char c;
if ((cc = read(STDIN_FILENO, &c, 1)) != 1) {
if (cc < 0)
syslog(LOG_NOTICE, "read: %m");
shutdown(STDIN_FILENO, SHUT_RDWR);
exit(1);
}
if (c == 0)
break;
port = port * 10 + c - '0';
}
(void) alarm(0);
if (port != 0) {
int lport;
#ifdef KERBEROS
if (!use_kerberos)
#endif
if (port >= IPPORT_RESERVED ||
port < IPPORT_RESERVED/2) {
syslog(LOG_ERR, "2nd port not reserved");
exit(1);
}
*portp = htons(port);
lport = IPPORT_RESERVED - 1;
s = rresvport_af(&lport, fromp->sa_family);
if (s < 0) {
syslog(LOG_ERR, "can't get stderr port: %m");
exit(1);
}
if (connect(s, (struct sockaddr *)fromp, fromp->sa_len) < 0) {
syslog(LOG_INFO, "connect second port %d: %m", port);
exit(1);
}
}
#ifdef KERBEROS
if (vacuous) {
error("rshd: remote host requires Kerberos authentication\n");
exit(1);
}
#endif
#ifdef notdef
/* from inetd, socket is already on 0, 1, 2 */
dup2(f, 0);
dup2(f, 1);
dup2(f, 2);
#endif
errorstr = NULL;
if (getnameinfo(fromp, fromp->sa_len, saddr, sizeof(saddr),
NULL, 0, NI_NAMEREQD)== 0) {
/*
* If name returned by getnameinfo 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 = saddr;
res0 = NULL;
#ifdef KERBEROS
if (!use_kerberos)
#endif
if (check_all || local_domain(saddr)) {
strlcpy(remotehost, saddr, sizeof(remotehost));
errorhost = remotehost;
memset(&hints, 0, sizeof(hints));
hints.ai_family = fromp->sa_family;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_CANONNAME;
gaierror = getaddrinfo(remotehost, pbuf, &hints, &res0);
if (gaierror) {
syslog(LOG_INFO,
"Couldn't look up address for %s: %s",
remotehost, gai_strerror(gaierror));
errorstr =
"Couldn't look up address for your host (%s)\n";
hostname = naddr;
} else {
for (res = res0; res; res = res->ai_next) {
if (res->ai_family != fromp->sa_family)
continue;
if (res->ai_addrlen != fromp->sa_len)
continue;
if (getnameinfo(res->ai_addr,
res->ai_addrlen,
raddr, sizeof(raddr), NULL, 0,
niflags) == 0
&& strcmp(naddr, raddr) == 0) {
hostname = res->ai_canonname
? res->ai_canonname
: saddr;
break;
}
}
if (res == NULL) {
syslog(LOG_NOTICE,
"Host addr %s not listed for host %s",
naddr, res0->ai_canonname
? res0->ai_canonname
: saddr);
errorstr =
"Host address mismatch for %s\n";
hostname = naddr;
}
}
}
strlcpy(hostnamebuf, hostname, sizeof(hostnamebuf));
hostname = hostnamebuf;
if (res0)
freeaddrinfo(res0);
} else
strlcpy(hostnamebuf, naddr, sizeof(hostnamebuf));
errorhost = hostname = hostnamebuf;
#ifdef KERBEROS
if (use_kerberos) {
kdata = (AUTH_DAT *) authbuf;
ticket = (KTEXT) tickbuf;
authopts = 0L;
strlcpy(instance, "*", sizeof instance);
version[VERSION_SIZE - 1] = '\0';
#ifdef CRYPT
if (doencrypt) {
struct sockaddr_in local_addr;
rc = sizeof(local_addr);
if (getsockname(STDIN_FILENO,
(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, (struct sockaddr_in *)&fromaddr,
&local_addr, kdata, "", schedule, version);
desrw_set_key(&kdata->session, &schedule);
} else
#endif
rc = krb_recvauth(authopts, 0, ticket, "rcmd",
instance, (struct sockaddr_in *)&fromaddr,
NULL, kdata, "", NULL, version);
if (rc != KSUCCESS) {
error("Kerberos authentication failure: %s\n",
krb_get_err_text(rc));
exit(1);
}
} else
#endif
getstr(remuser, sizeof(remuser), "remuser");
getstr(locuser, sizeof(locuser), "locuser");
getstr(cmdbuf, sizeof(cmdbuf), "command");
pwd = getpwnam(locuser);
if (pwd == NULL) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: unknown login. cmd='%.80s'",
remuser, hostname, locuser, cmdbuf);
if (errorstr == NULL)
errorstr = "Permission denied.\n";
goto fail;
}
lc = login_getclass(pwd->pw_class);
if (lc == NULL) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: unknown class. cmd='%.80s'",
remuser, hostname, locuser, cmdbuf);
if (errorstr == NULL)
errorstr = "Login incorrect.\n";
goto fail;
}
as = auth_open();
if (as == NULL || auth_setpwd(as, pwd) != 0) {
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: unable to allocate memory. cmd='%.80s'",
remuser, hostname, locuser, cmdbuf);
if (errorstr == NULL)
errorstr = "Cannot allocate memory.\n";
goto fail;
}
setegid(pwd->pw_gid);
seteuid(pwd->pw_uid);
if (chdir(pwd->pw_dir) < 0) {
(void) chdir("/");
#ifdef notdef
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: no home directory. cmd='%.80s'",
remuser, hostname, locuser, cmdbuf);
error("No remote directory.\n");
exit(1);
#endif
}
seteuid(0);
setegid(0); /* XXX use a saved gid instead? */
#ifdef KERBEROS
if (use_kerberos) {
if (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0') {
if (kuserok(kdata, locuser) != 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
if (errorstr ||
(pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' &&
iruserok_sa(fromp, fromp->sa_len, pwd->pw_uid == 0,
remuser, locuser) < 0)) {
if (__rcmd_errstr)
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: permission denied (%s). cmd='%.80s'",
remuser, hostname, locuser, __rcmd_errstr,
cmdbuf);
else
syslog(LOG_INFO|LOG_AUTH,
"%s@%s as %s: permission denied. cmd='%.80s'",
remuser, hostname, locuser, cmdbuf);
fail:
if (errorstr == NULL)
errorstr = "Permission denied.\n";
error(errorstr, errorhost);
exit(1);
}
if (pwd->pw_uid)
auth_checknologin(lc);
(void) write(STDERR_FILENO, "\0", 1);
sent_null = 1;
if (port) {
if (pipe(pv) < 0) {
error("Can't make pipe.\n");
exit(1);
}
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt) {
if (pipe(pv1) < 0) {
error("Can't make 2nd pipe.\n");
exit(1);
}
if (pipe(pv2) < 0) {
error("Can't make 3rd pipe.\n");
exit(1);
}
}
#endif
#endif
pid = fork();
if (pid == -1) {
error("Can't fork; try again.\n");
exit(1);
}
if (pid) {
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt) {
static char msg[] = SECURE_MESSAGE;
(void) close(pv1[1]);
(void) close(pv2[1]);
des_write(s, msg, sizeof(msg) - 1);
} else
#endif
#endif
{
(void) close(STDIN_FILENO);
(void) close(STDOUT_FILENO);
}
(void) close(STDERR_FILENO);
(void) close(pv[1]);
pfd[P_SOCKREAD].fd = s;
pfd[P_SOCKREAD].events = POLLIN;
pfd[P_PIPEREAD].fd = pv[0];
pfd[P_PIPEREAD].events = POLLIN;
nfd = 2;
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt) {
pfd[P_CRYPTREAD].fd = pv1[0];
pfd[P_CRYPTREAD].events = POLLIN;
pfd[P_CRYPTWRITE].fd = pv2[0];
pfd[P_CRYPTWRITE].events = POLLOUT;
nfd += 2;
} else
#endif
#endif
ioctl(pv[0], FIONBIO, (char *)&one);
/* should set s nbio! */
do {
if (poll(pfd, nfd, INFTIM) < 0)
break;
if (pfd[P_SOCKREAD].revents & POLLIN) {
int ret;
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt)
ret = des_read(s, &sig, 1);
else
#endif
#endif
ret = read(s, &sig, 1);
if (ret <= 0)
pfd[P_SOCKREAD].revents = 0;
else
killpg(pid, sig);
}
if (pfd[P_PIPEREAD].revents & POLLIN) {
errno = 0;
cc = read(pv[0], buf, sizeof(buf));
if (cc <= 0) {
shutdown(s, SHUT_RDWR);
pfd[P_PIPEREAD].revents = 0;
} else {
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt)
(void)
des_write(s, buf, cc);
else
#endif
#endif
(void)
write(s, buf, cc);
}
}
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt &&
(pfd[P_CRYPTREAD].revents & POLLIN)) {
errno = 0;
cc = read(pv1[0], buf, sizeof(buf));
if (cc <= 0) {
shutdown(pv1[0], SHUT_RDWR);
pfd[P_CRYPTREAD].revents = 0;
} else
(void) des_write(STDOUT_FILENO,
buf, cc);
}
if (doencrypt &&
(pfd[P_CRYPTWRITE].revents & POLLIN)) {
errno = 0;
cc = des_read(STDIN_FILENO,
buf, sizeof(buf));
if (cc <= 0) {
shutdown(pv2[0], SHUT_RDWR);
pfd[P_CRYPTWRITE].revents = 0;
} else
(void) write(pv2[0], buf, cc);
}
#endif
#endif
} while ((pfd[P_SOCKREAD].revents & POLLIN) ||
#ifdef CRYPT
#ifdef KERBEROS
(doencrypt && (pfd[P_CRYPTREAD].revents & POLLIN)) ||
#endif
#endif
(pfd[P_PIPEREAD].revents & POLLIN));
exit(0);
}
setsid();
(void) close(s);
(void) close(pv[0]);
#ifdef CRYPT
#ifdef KERBEROS
if (doencrypt) {
close(pv1[0]); close(pv2[0]);
dup2(pv1[1], 1);
dup2(pv2[1], 0);
close(pv1[1]);
close(pv2[1]);
}
#endif
#endif
dup2(pv[1], 2);
close(pv[1]);
} else
setsid();
if (*pwd->pw_shell == '\0')
pwd->pw_shell = _PATH_BSHELL;
environ = envinit;
if (setenv("HOME", pwd->pw_dir, 1) == -1 ||
setenv("SHELL", pwd->pw_shell, 1) == -1 ||
setenv("USER", pwd->pw_name, 1) == -1 ||
setenv("LOGNAME", pwd->pw_name, 1) == -1)
errx(1, "cannot setup environment");
if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETALL))
errx(1, "cannot set user context");
if (auth_approval(as, lc, pwd->pw_name, "rsh") <= 0)
errx(1, "approval failure");
auth_close(as);
login_close(lc);
cp = strrchr(pwd->pw_shell, '/');
if (cp)
cp++;
else
cp = pwd->pw_shell;
endpwent();
if (log_success || pwd->pw_uid == 0) {
#ifdef 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, locuser, cmdbuf);
else
#endif
syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'",
remuser, hostname, locuser, cmdbuf);
}
execl(pwd->pw_shell, cp, "-c", cmdbuf, (char *)NULL);
perror(pwd->pw_shell);
exit(1);
}
