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| Current File : //usr/src/crypto/heimdal/appl/rsh/rshd.c |
/*
* Copyright (c) 1997-2007 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* 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 Institute 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 INSTITUTE 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 INSTITUTE 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 "rsh_locl.h"
#include "login_locl.h"
RCSID("$Id: rshd.c 21515 2007-07-12 12:47:07Z lha $");
int
login_access( struct passwd *user, char *from);
int
read_limits_conf(const char *file, const struct passwd *pwd);
#ifdef NEED_IRUSEROK_PROTO
int iruserok(uint32_t, int, const char *, const char *);
#endif
enum auth_method auth_method;
#ifdef KRB5
krb5_context context;
krb5_keyblock *keyblock;
krb5_crypto crypto;
#endif
#ifdef KRB4
des_key_schedule schedule;
des_cblock iv;
#endif
#ifdef KRB5
krb5_ccache ccache, ccache2;
int kerberos_status = 0;
#endif
int do_encrypt = 0;
static int do_unique_tkfile = 0;
static char tkfile[MAXPATHLEN] = "";
static int do_inetd = 1;
static char *port_str;
static int do_rhosts = 1;
static int do_kerberos = 0;
#define DO_KRB4 2
#define DO_KRB5 4
static int do_vacuous = 0;
static int do_log = 1;
static int do_newpag = 1;
static int do_addr_verify = 0;
static int do_keepalive = 1;
static int do_version;
static int do_help = 0;
static void
syslog_and_die (const char *m, ...)
__attribute__ ((format (printf, 1, 2)));
static void
syslog_and_die (const char *m, ...)
{
va_list args;
va_start(args, m);
vsyslog (LOG_ERR, m, args);
va_end(args);
exit (1);
}
static void
fatal (int, const char*, const char *, ...)
__attribute__ ((noreturn, format (printf, 3, 4)));
static void
fatal (int sock, const char *what, const char *m, ...)
{
va_list args;
char buf[BUFSIZ];
size_t len;
*buf = 1;
va_start(args, m);
len = vsnprintf (buf + 1, sizeof(buf) - 1, m, args);
len = min(len, sizeof(buf) - 1);
va_end(args);
if(what != NULL)
syslog (LOG_ERR, "%s: %m: %s", what, buf + 1);
else
syslog (LOG_ERR, "%s", buf + 1);
net_write (sock, buf, len + 1);
exit (1);
}
static char *
read_str (int s, size_t sz, char *expl)
{
char *str = malloc(sz);
char *p = str;
if(str == NULL)
fatal(s, NULL, "%s too long", expl);
while(p < str + sz) {
if(net_read(s, p, 1) != 1)
syslog_and_die("read: %m");
if(*p == '\0')
return str;
p++;
}
fatal(s, NULL, "%s too long", expl);
}
static int
recv_bsd_auth (int s, u_char *buf,
struct sockaddr_in *thisaddr,
struct sockaddr_in *thataddr,
char **client_username,
char **server_username,
char **cmd)
{
struct passwd *pwd;
*client_username = read_str (s, USERNAME_SZ, "local username");
*server_username = read_str (s, USERNAME_SZ, "remote username");
*cmd = read_str (s, ARG_MAX + 1, "command");
pwd = getpwnam(*server_username);
if (pwd == NULL)
fatal(s, NULL, "Login incorrect.");
if (iruserok(thataddr->sin_addr.s_addr, pwd->pw_uid == 0,
*client_username, *server_username))
fatal(s, NULL, "Login incorrect.");
return 0;
}
#ifdef KRB4
static int
recv_krb4_auth (int s, u_char *buf,
struct sockaddr *thisaddr,
struct sockaddr *thataddr,
char **client_username,
char **server_username,
char **cmd)
{
int status;
int32_t options;
KTEXT_ST ticket;
AUTH_DAT auth;
char instance[INST_SZ + 1];
char version[KRB_SENDAUTH_VLEN + 1];
if (memcmp (buf, KRB_SENDAUTH_VERS, 4) != 0)
return -1;
if (net_read (s, buf + 4, KRB_SENDAUTH_VLEN - 4) !=
KRB_SENDAUTH_VLEN - 4)
syslog_and_die ("reading auth info: %m");
if (memcmp (buf, KRB_SENDAUTH_VERS, KRB_SENDAUTH_VLEN) != 0)
syslog_and_die("unrecognized auth protocol: %.8s", buf);
options = KOPT_IGNORE_PROTOCOL;
if (do_encrypt)
options |= KOPT_DO_MUTUAL;
k_getsockinst (s, instance, sizeof(instance));
status = krb_recvauth (options,
s,
&ticket,
"rcmd",
instance,
(struct sockaddr_in *)thataddr,
(struct sockaddr_in *)thisaddr,
&auth,
"",
schedule,
version);
if (status != KSUCCESS)
syslog_and_die ("recvauth: %s", krb_get_err_text(status));
if (strncmp (version, KCMD_OLD_VERSION, KRB_SENDAUTH_VLEN) != 0)
syslog_and_die ("bad version: %s", version);
*server_username = read_str (s, USERNAME_SZ, "remote username");
if (kuserok (&auth, *server_username) != 0)
fatal (s, NULL, "Permission denied.");
*cmd = read_str (s, ARG_MAX + 1, "command");
syslog(LOG_INFO|LOG_AUTH,
"kerberos v4 shell from %s on %s as %s, cmd '%.80s'",
krb_unparse_name_long(auth.pname, auth.pinst, auth.prealm),
inet_ntoa(((struct sockaddr_in *)thataddr)->sin_addr),
*server_username,
*cmd);
memcpy (iv, auth.session, sizeof(iv));
return 0;
}
#endif /* KRB4 */
#ifdef KRB5
static int
save_krb5_creds (int s,
krb5_auth_context auth_context,
krb5_principal client)
{
int ret;
krb5_data remote_cred;
krb5_data_zero (&remote_cred);
ret= krb5_read_message (context, (void *)&s, &remote_cred);
if (ret) {
krb5_data_free(&remote_cred);
return 0;
}
if (remote_cred.length == 0)
return 0;
ret = krb5_cc_gen_new(context, &krb5_mcc_ops, &ccache);
if (ret) {
krb5_data_free(&remote_cred);
return 0;
}
krb5_cc_initialize(context,ccache,client);
ret = krb5_rd_cred2(context, auth_context, ccache, &remote_cred);
if(ret != 0)
syslog(LOG_INFO|LOG_AUTH,
"reading creds: %s", krb5_get_err_text(context, ret));
krb5_data_free (&remote_cred);
if (ret)
return 0;
return 1;
}
static void
krb5_start_session (void)
{
krb5_error_code ret;
char *estr;
ret = krb5_cc_resolve (context, tkfile, &ccache2);
if (ret) {
estr = krb5_get_error_string(context);
syslog(LOG_WARNING, "resolve cred cache %s: %s",
tkfile,
estr ? estr : krb5_get_err_text(context, ret));
free(estr);
krb5_cc_destroy(context, ccache);
return;
}
ret = krb5_cc_copy_cache (context, ccache, ccache2);
if (ret) {
estr = krb5_get_error_string(context);
syslog(LOG_WARNING, "storing credentials: %s",
estr ? estr : krb5_get_err_text(context, ret));
free(estr);
krb5_cc_destroy(context, ccache);
return ;
}
krb5_cc_close(context, ccache2);
krb5_cc_destroy(context, ccache);
return;
}
static int protocol_version;
static krb5_boolean
match_kcmd_version(const void *data, const char *version)
{
if(strcmp(version, KCMD_NEW_VERSION) == 0) {
protocol_version = 2;
return TRUE;
}
if(strcmp(version, KCMD_OLD_VERSION) == 0) {
protocol_version = 1;
key_usage = KRB5_KU_OTHER_ENCRYPTED;
return TRUE;
}
return FALSE;
}
static int
recv_krb5_auth (int s, u_char *buf,
struct sockaddr *thisaddr,
struct sockaddr *thataddr,
char **client_username,
char **server_username,
char **cmd)
{
uint32_t len;
krb5_auth_context auth_context = NULL;
krb5_ticket *ticket;
krb5_error_code status;
krb5_data cksum_data;
krb5_principal server;
char *str;
if (memcmp (buf, "\x00\x00\x00\x13", 4) != 0)
return -1;
len = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | (buf[3]);
if (net_read(s, buf, len) != len)
syslog_and_die ("reading auth info: %m");
if (len != sizeof(KRB5_SENDAUTH_VERSION)
|| memcmp (buf, KRB5_SENDAUTH_VERSION, len) != 0)
syslog_and_die ("bad sendauth version: %.8s", buf);
status = krb5_sock_to_principal (context,
s,
"host",
KRB5_NT_SRV_HST,
&server);
if (status)
syslog_and_die ("krb5_sock_to_principal: %s",
krb5_get_err_text(context, status));
status = krb5_recvauth_match_version(context,
&auth_context,
&s,
match_kcmd_version,
NULL,
server,
KRB5_RECVAUTH_IGNORE_VERSION,
NULL,
&ticket);
krb5_free_principal (context, server);
if (status)
syslog_and_die ("krb5_recvauth: %s",
krb5_get_err_text(context, status));
*server_username = read_str (s, USERNAME_SZ, "remote username");
*cmd = read_str (s, ARG_MAX + 1, "command");
*client_username = read_str (s, ARG_MAX + 1, "local username");
if(protocol_version == 2) {
status = krb5_auth_con_getremotesubkey(context, auth_context,
&keyblock);
if(status != 0 || keyblock == NULL)
syslog_and_die("failed to get remote subkey");
} else if(protocol_version == 1) {
status = krb5_auth_con_getkey (context, auth_context, &keyblock);
if(status != 0 || keyblock == NULL)
syslog_and_die("failed to get key");
}
if (status != 0 || keyblock == NULL)
syslog_and_die ("krb5_auth_con_getkey: %s",
krb5_get_err_text(context, status));
status = krb5_crypto_init(context, keyblock, 0, &crypto);
if(status)
syslog_and_die("krb5_crypto_init: %s",
krb5_get_err_text(context, status));
cksum_data.length = asprintf (&str,
"%u:%s%s",
ntohs(socket_get_port (thisaddr)),
*cmd,
*server_username);
if (str == NULL)
syslog_and_die ("asprintf: out of memory");
cksum_data.data = str;
status = krb5_verify_authenticator_checksum(context,
auth_context,
cksum_data.data,
cksum_data.length);
if (status)
syslog_and_die ("krb5_verify_authenticator_checksum: %s",
krb5_get_err_text(context, status));
free (cksum_data.data);
if (strncmp (*client_username, "-u ", 3) == 0) {
do_unique_tkfile = 1;
memmove (*client_username, *client_username + 3,
strlen(*client_username) - 2);
}
if (strncmp (*client_username, "-U ", 3) == 0) {
char *end, *temp_tkfile;
do_unique_tkfile = 1;
if (strncmp (*client_username + 3, "FILE:", 5) == 0) {
temp_tkfile = tkfile;
} else {
strlcpy (tkfile, "FILE:", sizeof(tkfile));
temp_tkfile = tkfile + 5;
}
end = strchr(*client_username + 3,' ');
if (end == NULL)
syslog_and_die("missing argument after -U");
snprintf(temp_tkfile, sizeof(tkfile) - (temp_tkfile - tkfile),
"%.*s",
(int)(end - *client_username - 3),
*client_username + 3);
memmove (*client_username, end + 1, strlen(end+1)+1);
}
kerberos_status = save_krb5_creds (s, auth_context, ticket->client);
if(!krb5_kuserok (context,
ticket->client,
*server_username))
fatal (s, NULL, "Permission denied.");
if (strncmp (*cmd, "-x ", 3) == 0) {
do_encrypt = 1;
memmove (*cmd, *cmd + 3, strlen(*cmd) - 2);
} else {
if(do_encrypt)
fatal (s, NULL, "Encryption is required.");
do_encrypt = 0;
}
{
char *name;
if (krb5_unparse_name (context, ticket->client, &name) == 0) {
char addr_str[256];
if (inet_ntop (thataddr->sa_family,
socket_get_address (thataddr),
addr_str, sizeof(addr_str)) == NULL)
strlcpy (addr_str, "unknown address",
sizeof(addr_str));
syslog(LOG_INFO|LOG_AUTH,
"kerberos v5 shell from %s on %s as %s, cmd '%.80s'",
name,
addr_str,
*server_username,
*cmd);
free (name);
}
}
return 0;
}
#endif /* KRB5 */
static void
rshd_loop (int from0, int to0,
int to1, int from1,
int to2, int from2,
int have_errsock)
{
fd_set real_readset;
int max_fd;
int count = 2;
char *buf;
if(from0 >= FD_SETSIZE || from1 >= FD_SETSIZE || from2 >= FD_SETSIZE)
errx (1, "fd too large");
#ifdef KRB5
if(auth_method == AUTH_KRB5 && protocol_version == 2)
init_ivecs(0, have_errsock);
#endif
FD_ZERO(&real_readset);
FD_SET(from0, &real_readset);
FD_SET(from1, &real_readset);
FD_SET(from2, &real_readset);
max_fd = max(from0, max(from1, from2)) + 1;
buf = malloc(max(RSHD_BUFSIZ, RSH_BUFSIZ));
if (buf == NULL)
syslog_and_die("out of memory");
for (;;) {
int ret;
fd_set readset = real_readset;
ret = select (max_fd, &readset, NULL, NULL, NULL);
if (ret < 0) {
if (errno == EINTR)
continue;
else
syslog_and_die ("select: %m");
}
if (FD_ISSET(from0, &readset)) {
ret = do_read (from0, buf, RSHD_BUFSIZ, ivec_in[0]);
if (ret < 0)
syslog_and_die ("read: %m");
else if (ret == 0) {
close (from0);
close (to0);
FD_CLR(from0, &real_readset);
} else
net_write (to0, buf, ret);
}
if (FD_ISSET(from1, &readset)) {
ret = read (from1, buf, RSH_BUFSIZ);
if (ret < 0)
syslog_and_die ("read: %m");
else if (ret == 0) {
close (from1);
close (to1);
FD_CLR(from1, &real_readset);
if (--count == 0)
exit (0);
} else
do_write (to1, buf, ret, ivec_out[0]);
}
if (FD_ISSET(from2, &readset)) {
ret = read (from2, buf, RSH_BUFSIZ);
if (ret < 0)
syslog_and_die ("read: %m");
else if (ret == 0) {
close (from2);
close (to2);
FD_CLR(from2, &real_readset);
if (--count == 0)
exit (0);
} else
do_write (to2, buf, ret, ivec_out[1]);
}
}
}
/*
* Used by `setup_copier' to create some pipe-like means of
* communcation. Real pipes would probably be the best thing, but
* then the shell doesn't understand it's talking to rshd. If
* socketpair doesn't work everywhere, some autoconf magic would have
* to be added here.
*
* If it fails creating the `pipe', it aborts by calling fatal.
*/
static void
pipe_a_like (int fd[2])
{
if (socketpair (AF_UNIX, SOCK_STREAM, 0, fd) < 0)
fatal (STDOUT_FILENO, "socketpair", "Pipe creation failed.");
}
/*
* Start a child process and leave the parent copying data to and from it. */
static void
setup_copier (int have_errsock)
{
int p0[2], p1[2], p2[2];
pid_t pid;
pipe_a_like(p0);
pipe_a_like(p1);
pipe_a_like(p2);
pid = fork ();
if (pid < 0)
fatal (STDOUT_FILENO, "fork", "Could not create child process.");
if (pid == 0) { /* child */
close (p0[1]);
close (p1[0]);
close (p2[0]);
dup2 (p0[0], STDIN_FILENO);
dup2 (p1[1], STDOUT_FILENO);
dup2 (p2[1], STDERR_FILENO);
close (p0[0]);
close (p1[1]);
close (p2[1]);
} else { /* parent */
close (p0[0]);
close (p1[1]);
close (p2[1]);
if (net_write (STDOUT_FILENO, "", 1) != 1)
fatal (STDOUT_FILENO, "net_write", "Write failure.");
rshd_loop (STDIN_FILENO, p0[1],
STDOUT_FILENO, p1[0],
STDERR_FILENO, p2[0],
have_errsock);
}
}
/*
* Is `port' a ``reserverd'' port?
*/
static int
is_reserved(u_short port)
{
return ntohs(port) < IPPORT_RESERVED;
}
/*
* Set the necessary part of the environment in `env'.
*/
static void
setup_environment (char ***env, const struct passwd *pwd)
{
int i, j, path;
char **e;
i = 0;
path = 0;
*env = NULL;
i = read_environment(_PATH_ETC_ENVIRONMENT, env);
e = *env;
for (j = 0; j < i; j++) {
if (!strncmp(e[j], "PATH=", 5)) {
path = 1;
}
}
e = *env;
e = realloc(e, (i + 7) * sizeof(char *));
if (asprintf (&e[i++], "USER=%s", pwd->pw_name) == -1)
syslog_and_die ("asprintf: out of memory");
if (asprintf (&e[i++], "HOME=%s", pwd->pw_dir) == -1)
syslog_and_die ("asprintf: out of memory");
if (asprintf (&e[i++], "SHELL=%s", pwd->pw_shell) == -1)
syslog_and_die ("asprintf: out of memory");
if (! path) {
if (asprintf (&e[i++], "PATH=%s", _PATH_DEFPATH) == -1)
syslog_and_die ("asprintf: out of memory");
}
asprintf (&e[i++], "SSH_CLIENT=only_to_make_bash_happy");
if (do_unique_tkfile)
if (asprintf (&e[i++], "KRB5CCNAME=%s", tkfile) == -1)
syslog_and_die ("asprintf: out of memory");
e[i++] = NULL;
*env = e;
}
static void
doit (void)
{
u_char buf[BUFSIZ];
u_char *p;
struct sockaddr_storage thisaddr_ss;
struct sockaddr *thisaddr = (struct sockaddr *)&thisaddr_ss;
struct sockaddr_storage thataddr_ss;
struct sockaddr *thataddr = (struct sockaddr *)&thataddr_ss;
struct sockaddr_storage erraddr_ss;
struct sockaddr *erraddr = (struct sockaddr *)&erraddr_ss;
socklen_t thisaddr_len, thataddr_len;
int port;
int errsock = -1;
char *client_user = NULL, *server_user = NULL, *cmd = NULL;
struct passwd *pwd;
int s = STDIN_FILENO;
char **env;
int ret;
char that_host[NI_MAXHOST];
thisaddr_len = sizeof(thisaddr_ss);
if (getsockname (s, thisaddr, &thisaddr_len) < 0)
syslog_and_die("getsockname: %m");
thataddr_len = sizeof(thataddr_ss);
if (getpeername (s, thataddr, &thataddr_len) < 0)
syslog_and_die ("getpeername: %m");
/* check for V4MAPPED addresses? */
if (do_kerberos == 0 && !is_reserved(socket_get_port(thataddr)))
fatal(s, NULL, "Permission denied.");
p = buf;
port = 0;
for(;;) {
if (net_read (s, p, 1) != 1)
syslog_and_die ("reading port number: %m");
if (*p == '\0')
break;
else if (isdigit(*p))
port = port * 10 + *p - '0';
else
syslog_and_die ("non-digit in port number: %c", *p);
}
if (do_kerberos == 0 && !is_reserved(htons(port)))
fatal(s, NULL, "Permission denied.");
if (port) {
int priv_port = IPPORT_RESERVED - 1;
/*
* There's no reason to require a ``privileged'' port number
* here, but for some reason the brain dead rsh clients
* do... :-(
*/
erraddr->sa_family = thataddr->sa_family;
socket_set_address_and_port (erraddr,
socket_get_address (thataddr),
htons(port));
/*
* we only do reserved port for IPv4
*/
if (erraddr->sa_family == AF_INET)
errsock = rresvport (&priv_port);
else
errsock = socket (erraddr->sa_family, SOCK_STREAM, 0);
if (errsock < 0)
syslog_and_die ("socket: %m");
if (connect (errsock,
erraddr,
socket_sockaddr_size (erraddr)) < 0) {
syslog (LOG_WARNING, "connect: %m");
close (errsock);
}
}
if(do_kerberos) {
if (net_read (s, buf, 4) != 4)
syslog_and_die ("reading auth info: %m");
#ifdef KRB4
if ((do_kerberos & DO_KRB4) &&
recv_krb4_auth (s, buf, thisaddr, thataddr,
&client_user,
&server_user,
&cmd) == 0)
auth_method = AUTH_KRB4;
else
#endif /* KRB4 */
#ifdef KRB5
if((do_kerberos & DO_KRB5) &&
recv_krb5_auth (s, buf, thisaddr, thataddr,
&client_user,
&server_user,
&cmd) == 0)
auth_method = AUTH_KRB5;
else
#endif /* KRB5 */
syslog_and_die ("unrecognized auth protocol: %x %x %x %x",
buf[0], buf[1], buf[2], buf[3]);
} else {
if(recv_bsd_auth (s, buf,
(struct sockaddr_in *)thisaddr,
(struct sockaddr_in *)thataddr,
&client_user,
&server_user,
&cmd) == 0) {
auth_method = AUTH_BROKEN;
if(do_vacuous) {
printf("Remote host requires Kerberos authentication\n");
exit(0);
}
} else
syslog_and_die("recv_bsd_auth failed");
}
if (client_user == NULL || server_user == NULL || cmd == NULL)
syslog_and_die("mising client/server/cmd");
pwd = getpwnam (server_user);
if (pwd == NULL)
fatal (s, NULL, "Login incorrect.");
if (*pwd->pw_shell == '\0')
pwd->pw_shell = _PATH_BSHELL;
if (pwd->pw_uid != 0 && access (_PATH_NOLOGIN, F_OK) == 0)
fatal (s, NULL, "Login disabled.");
ret = getnameinfo_verified (thataddr, thataddr_len,
that_host, sizeof(that_host),
NULL, 0, 0);
if (ret)
fatal (s, NULL, "getnameinfo: %s", gai_strerror(ret));
if (login_access(pwd, that_host) == 0) {
syslog(LOG_NOTICE, "Kerberos rsh denied to %s from %s",
server_user, that_host);
fatal(s, NULL, "Permission denied.");
}
#ifdef HAVE_GETSPNAM
{
struct spwd *sp;
long today;
sp = getspnam(server_user);
if (sp != NULL) {
today = time(0)/(24L * 60 * 60);
if (sp->sp_expire > 0)
if (today > sp->sp_expire)
fatal(s, NULL, "Account has expired.");
}
}
#endif
#ifdef HAVE_SETLOGIN
if (setlogin(pwd->pw_name) < 0)
syslog(LOG_ERR, "setlogin() failed: %m");
#endif
#ifdef HAVE_SETPCRED
if (setpcred (pwd->pw_name, NULL) == -1)
syslog(LOG_ERR, "setpcred() failure: %m");
#endif /* HAVE_SETPCRED */
/* Apply limits if not root */
if(pwd->pw_uid != 0) {
const char *file = _PATH_LIMITS_CONF;
read_limits_conf(file, pwd);
}
if (initgroups (pwd->pw_name, pwd->pw_gid) < 0)
fatal (s, "initgroups", "Login incorrect.");
if (setgid(pwd->pw_gid) < 0)
fatal (s, "setgid", "Login incorrect.");
if (setuid (pwd->pw_uid) < 0)
fatal (s, "setuid", "Login incorrect.");
if (chdir (pwd->pw_dir) < 0)
fatal (s, "chdir", "Remote directory.");
if (errsock >= 0) {
if (dup2 (errsock, STDERR_FILENO) < 0)
fatal (s, "dup2", "Cannot dup stderr.");
close (errsock);
} else {
if (dup2 (STDOUT_FILENO, STDERR_FILENO) < 0)
fatal (s, "dup2", "Cannot dup stderr.");
}
#ifdef KRB5
{
int fd;
if (!do_unique_tkfile)
snprintf(tkfile,sizeof(tkfile),"FILE:/tmp/krb5cc_%lu",
(unsigned long)pwd->pw_uid);
else if (*tkfile=='\0') {
snprintf(tkfile,sizeof(tkfile),"FILE:/tmp/krb5cc_XXXXXX");
fd = mkstemp(tkfile+5);
close(fd);
unlink(tkfile+5);
}
if (kerberos_status)
krb5_start_session();
}
#endif
setup_environment (&env, pwd);
if (do_encrypt) {
setup_copier (errsock >= 0);
} else {
if (net_write (s, "", 1) != 1)
fatal (s, "net_write", "write failed");
}
#if defined(KRB4) || defined(KRB5)
if(k_hasafs()) {
char cell[64];
if(do_newpag)
k_setpag();
#ifdef KRB4
if (k_afs_cell_of_file (pwd->pw_dir, cell, sizeof(cell)) == 0)
krb_afslog_uid_home (cell, NULL, pwd->pw_uid, pwd->pw_dir);
krb_afslog_uid_home(NULL, NULL, pwd->pw_uid, pwd->pw_dir);
#endif
#ifdef KRB5
/* XXX */
if (kerberos_status) {
krb5_ccache ccache;
krb5_error_code status;
status = krb5_cc_resolve (context, tkfile, &ccache);
if (!status) {
if (k_afs_cell_of_file (pwd->pw_dir, cell, sizeof(cell)) == 0)
krb5_afslog_uid_home(context, ccache, cell, NULL,
pwd->pw_uid, pwd->pw_dir);
krb5_afslog_uid_home(context, ccache, NULL, NULL,
pwd->pw_uid, pwd->pw_dir);
krb5_cc_close (context, ccache);
}
}
#endif /* KRB5 */
}
#endif /* KRB5 || KRB4 */
execle (pwd->pw_shell, pwd->pw_shell, "-c", cmd, NULL, env);
err(1, "exec %s", pwd->pw_shell);
}
struct getargs args[] = {
{ NULL, 'a', arg_flag, &do_addr_verify },
{ "keepalive", 'n', arg_negative_flag, &do_keepalive },
{ "inetd", 'i', arg_negative_flag, &do_inetd,
"Not started from inetd" },
#if defined(KRB4) || defined(KRB5)
{ "kerberos", 'k', arg_flag, &do_kerberos,
"Implement kerberised services" },
{ "encrypt", 'x', arg_flag, &do_encrypt,
"Implement encrypted service" },
#endif
{ "rhosts", 'l', arg_negative_flag, &do_rhosts,
"Don't check users .rhosts" },
{ "port", 'p', arg_string, &port_str, "Use this port",
"port" },
{ "vacuous", 'v', arg_flag, &do_vacuous,
"Don't accept non-kerberised connections" },
#if defined(KRB4) || defined(KRB5)
{ NULL, 'P', arg_negative_flag, &do_newpag,
"Don't put process in new PAG" },
#endif
/* compatibility flag: */
{ NULL, 'L', arg_flag, &do_log },
{ "version", 0, arg_flag, &do_version },
{ "help", 0, arg_flag, &do_help }
};
static void
usage (int ret)
{
if(isatty(STDIN_FILENO))
arg_printusage (args,
sizeof(args) / sizeof(args[0]),
NULL,
"");
else
syslog (LOG_ERR, "Usage: %s [-ikxlvPL] [-p port]", getprogname());
exit (ret);
}
int
main(int argc, char **argv)
{
int optind = 0;
int on = 1;
setprogname (argv[0]);
roken_openlog ("rshd", LOG_ODELAY | LOG_PID, LOG_AUTH);
if (getarg(args, sizeof(args) / sizeof(args[0]), argc, argv,
&optind))
usage(1);
if(do_help)
usage (0);
if (do_version) {
print_version(NULL);
exit(0);
}
#if defined(KRB4) || defined(KRB5)
if (do_encrypt)
do_kerberos = 1;
if(do_kerberos)
do_kerberos = DO_KRB4 | DO_KRB5;
#endif
#ifdef KRB5
if((do_kerberos & DO_KRB5) && krb5_init_context (&context) != 0)
do_kerberos &= ~DO_KRB5;
#endif
if (!do_inetd) {
int error;
struct addrinfo *ai = NULL, hints;
char portstr[NI_MAXSERV];
memset (&hints, 0, sizeof(hints));
hints.ai_flags = AI_PASSIVE;
hints.ai_socktype = SOCK_STREAM;
hints.ai_family = PF_UNSPEC;
if(port_str != NULL) {
error = getaddrinfo (NULL, port_str, &hints, &ai);
if (error)
errx (1, "getaddrinfo: %s", gai_strerror (error));
}
if (ai == NULL) {
#if defined(KRB4) || defined(KRB5)
if (do_kerberos) {
if (do_encrypt) {
error = getaddrinfo(NULL, "ekshell", &hints, &ai);
if(error == EAI_NONAME) {
snprintf(portstr, sizeof(portstr), "%d", 545);
error = getaddrinfo(NULL, portstr, &hints, &ai);
}
if(error)
errx (1, "getaddrinfo: %s", gai_strerror (error));
} else {
error = getaddrinfo(NULL, "kshell", &hints, &ai);
if(error == EAI_NONAME) {
snprintf(portstr, sizeof(portstr), "%d", 544);
error = getaddrinfo(NULL, portstr, &hints, &ai);
}
if(error)
errx (1, "getaddrinfo: %s", gai_strerror (error));
}
} else
#endif
{
error = getaddrinfo(NULL, "shell", &hints, &ai);
if(error == EAI_NONAME) {
snprintf(portstr, sizeof(portstr), "%d", 514);
error = getaddrinfo(NULL, portstr, &hints, &ai);
}
if(error)
errx (1, "getaddrinfo: %s", gai_strerror (error));
}
}
mini_inetd_addrinfo (ai);
freeaddrinfo(ai);
}
if (do_keepalive &&
setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, (char *)&on,
sizeof(on)) < 0)
syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
/* set SO_LINGER? */
signal (SIGPIPE, SIG_IGN);
doit ();
return 0;
}