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/*
* Copyright (C) 2004 Andrew Beekhof <andrew@beekhof.net>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <crm_internal.h>
#include <crm/crm.h>
#include <sys/param.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/ip.h>
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <glib.h>
#include <crm/msg_xml.h>
#include <crm/common/ipc.h>
#include <crm/common/xml.h>
#include <crm/cib/internal.h>
#include "callbacks.h"
/* #undef HAVE_PAM_PAM_APPL_H */
/* #undef HAVE_GNUTLS_GNUTLS_H */
#ifdef HAVE_GNUTLS_GNUTLS_H
# undef KEYFILE
# include <gnutls/gnutls.h>
#endif
#include <pwd.h>
#include <grp.h>
#if HAVE_SECURITY_PAM_APPL_H
# include <security/pam_appl.h>
# define HAVE_PAM 1
#else
# if HAVE_PAM_PAM_APPL_H
# include <pam/pam_appl.h>
# define HAVE_PAM 1
# endif
#endif
#ifdef HAVE_DECL_NANOSLEEP
# include <time.h>
#endif
extern int remote_tls_fd;
extern gboolean cib_shutdown_flag;
int init_remote_listener(int port, gboolean encrypted);
void cib_remote_connection_destroy(gpointer user_data);
#ifdef HAVE_GNUTLS_GNUTLS_H
# define DH_BITS 1024
gnutls_dh_params dh_params;
extern gnutls_anon_server_credentials anon_cred_s;
static void
debug_log(int level, const char *str)
{
fputs(str, stderr);
}
extern gnutls_session *create_tls_session(int csock, int type);
#endif
int num_clients;
int authenticate_user(const char *user, const char *passwd);
int cib_remote_listen(gpointer data);
int cib_remote_msg(gpointer data);
static void
remote_connection_destroy(gpointer user_data)
{
return;
}
#define ERROR_SUFFIX " Shutting down remote listener"
int
init_remote_listener(int port, gboolean encrypted)
{
int ssock;
struct sockaddr_in saddr;
int optval;
static struct mainloop_fd_callbacks remote_listen_fd_callbacks =
{
.dispatch = cib_remote_listen,
.destroy = remote_connection_destroy,
};
if (port <= 0) {
/* dont start it */
return 0;
}
if (encrypted) {
#ifndef HAVE_GNUTLS_GNUTLS_H
crm_warn("TLS support is not available");
return 0;
#else
crm_notice("Starting a tls listener on port %d.", port);
gnutls_global_init();
/* gnutls_global_set_log_level (10); */
gnutls_global_set_log_function(debug_log);
gnutls_dh_params_init(&dh_params);
gnutls_dh_params_generate2(dh_params, DH_BITS);
gnutls_anon_allocate_server_credentials(&anon_cred_s);
gnutls_anon_set_server_dh_params(anon_cred_s, dh_params);
#endif
} else {
crm_warn("Starting a plain_text listener on port %d.", port);
}
#ifndef HAVE_PAM
crm_warn("PAM is _not_ enabled!");
#endif
/* create server socket */
ssock = socket(AF_INET, SOCK_STREAM, 0);
if (ssock == -1) {
crm_perror(LOG_ERR, "Can not create server socket." ERROR_SUFFIX);
return -1;
}
/* reuse address */
optval = 1;
setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval));
/* bind server socket */
memset(&saddr, '\0', sizeof(saddr));
saddr.sin_family = AF_INET;
saddr.sin_addr.s_addr = INADDR_ANY;
saddr.sin_port = htons(port);
if (bind(ssock, (struct sockaddr *)&saddr, sizeof(saddr)) == -1) {
crm_perror(LOG_ERR, "Can not bind server socket." ERROR_SUFFIX);
close(ssock);
return -2;
}
if (listen(ssock, 10) == -1) {
crm_perror(LOG_ERR, "Can not start listen." ERROR_SUFFIX);
close(ssock);
return -3;
}
mainloop_add_fd("cib-remote", G_PRIORITY_DEFAULT, ssock, &ssock, &remote_listen_fd_callbacks);
return ssock;
}
static int
check_group_membership(const char *usr, const char *grp)
{
int index = 0;
struct passwd *pwd = NULL;
struct group *group = NULL;
CRM_CHECK(usr != NULL, return FALSE);
CRM_CHECK(grp != NULL, return FALSE);
pwd = getpwnam(usr);
if (pwd == NULL) {
crm_err("No user named '%s' exists!", usr);
return FALSE;
}
group = getgrgid(pwd->pw_gid);
if (group != NULL && crm_str_eq(grp, group->gr_name, TRUE)) {
return TRUE;
}
group = getgrnam(grp);
if (group == NULL) {
crm_err("No group named '%s' exists!", grp);
return FALSE;
}
while (TRUE) {
char *member = group->gr_mem[index++];
if (member == NULL) {
break;
} else if (crm_str_eq(usr, member, TRUE)) {
return TRUE;
}
};
return FALSE;
}
int
cib_remote_listen(gpointer data)
{
int lpc = 0;
int csock = 0;
unsigned laddr;
time_t now = 0;
time_t start = time(NULL);
struct sockaddr_in addr;
int ssock = *(int *)data;
#ifdef HAVE_GNUTLS_GNUTLS_H
gnutls_session *session = NULL;
#endif
cib_client_t *new_client = NULL;
xmlNode *login = NULL;
const char *user = NULL;
const char *pass = NULL;
const char *tmp = NULL;
#ifdef HAVE_DECL_NANOSLEEP
const struct timespec sleepfast = { 0, 10000000 }; /* 10 millisec */
#endif
static struct mainloop_fd_callbacks remote_client_fd_callbacks =
{
.dispatch = cib_remote_msg,
.destroy = cib_remote_connection_destroy,
};
/* accept the connection */
laddr = sizeof(addr);
csock = accept(ssock, (struct sockaddr *)&addr, &laddr);
crm_debug("New %s connection from %s",
ssock == remote_tls_fd ? "secure" : "clear-text", inet_ntoa(addr.sin_addr));
if (csock == -1) {
crm_err("accept socket failed");
return TRUE;
}
if (ssock == remote_tls_fd) {
#ifdef HAVE_GNUTLS_GNUTLS_H
/* create gnutls session for the server socket */
session = create_tls_session(csock, GNUTLS_SERVER);
if (session == NULL) {
crm_err("TLS session creation failed");
close(csock);
return TRUE;
}
#endif
}
do {
crm_trace("Iter: %d", lpc++);
if (ssock == remote_tls_fd) {
#ifdef HAVE_GNUTLS_GNUTLS_H
login = crm_recv_remote_msg(session, TRUE);
#endif
} else {
login = crm_recv_remote_msg(GINT_TO_POINTER(csock), FALSE);
}
if (login != NULL) {
break;
}
#ifdef HAVE_DECL_NANOSLEEP
nanosleep(&sleepfast, NULL);
#else
sleep(1);
#endif
now = time(NULL);
/* Peers have 3s to connect */
} while (login == NULL && (start - now) < 4);
crm_log_xml_info(login, "Login: ");
if (login == NULL) {
goto bail;
}
tmp = crm_element_name(login);
if (safe_str_neq(tmp, "cib_command")) {
crm_err("Wrong tag: %s", tmp);
goto bail;
}
tmp = crm_element_value(login, "op");
if (safe_str_neq(tmp, "authenticate")) {
crm_err("Wrong operation: %s", tmp);
goto bail;
}
user = crm_element_value(login, "user");
pass = crm_element_value(login, "password");
/* Non-root daemons can only validate the password of the
* user they're running as
*/
if (check_group_membership(user, CRM_DAEMON_GROUP) == FALSE) {
crm_err("User is not a member of the required group");
goto bail;
} else if (authenticate_user(user, pass) == FALSE) {
crm_err("PAM auth failed");
goto bail;
}
/* send ACK */
num_clients++;
new_client = calloc(1, sizeof(cib_client_t));
new_client->name = crm_element_value_copy(login, "name");
CRM_CHECK(new_client->id == NULL, free(new_client->id));
new_client->id = crm_generate_uuid();
#if ENABLE_ACL
new_client->user = strdup(user);
#endif
new_client->callback_id = NULL;
if (ssock == remote_tls_fd) {
#ifdef HAVE_GNUTLS_GNUTLS_H
new_client->encrypted = TRUE;
new_client->session = session;
#endif
} else {
new_client->session = GINT_TO_POINTER(csock);
}
free_xml(login);
login = create_xml_node(NULL, "cib_result");
crm_xml_add(login, F_CIB_OPERATION, CRM_OP_REGISTER);
crm_xml_add(login, F_CIB_CLIENTID, new_client->id);
crm_send_remote_msg(new_client->session, login, new_client->encrypted);
free_xml(login);
new_client->remote = mainloop_add_fd(
"cib-remote-client", G_PRIORITY_DEFAULT, csock, new_client, &remote_client_fd_callbacks);
g_hash_table_insert(client_list, new_client->id, new_client);
return TRUE;
bail:
if (ssock == remote_tls_fd) {
#ifdef HAVE_GNUTLS_GNUTLS_H
gnutls_bye(*session, GNUTLS_SHUT_RDWR);
gnutls_deinit(*session);
gnutls_free(session);
#endif
}
close(csock);
free_xml(login);
return TRUE;
}
void
cib_remote_connection_destroy(gpointer user_data)
{
cib_client_t *client = user_data;
if (client == NULL) {
return;
}
crm_trace("Cleaning up after client disconnect: %s/%s",
crm_str(client->name), client->id);
if (client->id != NULL) {
if (!g_hash_table_remove(client_list, client->id)) {
crm_err("Client %s not found in the hashtable", client->name);
}
}
crm_trace("Destroying %s (%p)", client->name, user_data);
num_clients--;
crm_trace("Num unfree'd clients: %d", num_clients);
free(client->name);
free(client->callback_id);
free(client->id);
free(client->user);
free(client);
crm_trace("Freed the cib client");
if (cib_shutdown_flag) {
cib_shutdown(0);
}
return;
}
int
cib_remote_msg(gpointer data)
{
const char *value = NULL;
xmlNode *command = NULL;
cib_client_t *client = data;
crm_trace("%s callback", client->encrypted ? "secure" : "clear-text");
command = crm_recv_remote_msg(client->session, client->encrypted);
if (command == NULL) {
return -1;
}
value = crm_element_name(command);
if (safe_str_neq(value, "cib_command")) {
crm_log_xml_trace(command, "Bad command: ");
goto bail;
}
if (client->name == NULL) {
value = crm_element_value(command, F_CLIENTNAME);
if (value == NULL) {
client->name = strdup(client->id);
} else {
client->name = strdup(value);
}
}
if (client->callback_id == NULL) {
value = crm_element_value(command, F_CIB_CALLBACK_TOKEN);
if (value != NULL) {
client->callback_id = strdup(value);
crm_trace("Callback channel for %s is %s", client->id, client->callback_id);
} else {
client->callback_id = strdup(client->id);
}
}
/* unset dangerous options */
xml_remove_prop(command, F_ORIG);
xml_remove_prop(command, F_CIB_HOST);
xml_remove_prop(command, F_CIB_GLOBAL_UPDATE);
crm_xml_add(command, F_TYPE, T_CIB);
crm_xml_add(command, F_CIB_CLIENTID, client->id);
crm_xml_add(command, F_CIB_CLIENTNAME, client->name);
#if ENABLE_ACL
crm_xml_add(command, F_CIB_USER, client->user);
#endif
if (crm_element_value(command, F_CIB_CALLID) == NULL) {
char *call_uuid = crm_generate_uuid();
/* fix the command */
crm_xml_add(command, F_CIB_CALLID, call_uuid);
free(call_uuid);
}
if (crm_element_value(command, F_CIB_CALLOPTS) == NULL) {
crm_xml_add_int(command, F_CIB_CALLOPTS, 0);
}
crm_log_xml_trace(command, "Remote command: ");
cib_common_callback_worker(0, 0, command, client, TRUE);
bail:
free_xml(command);
command = NULL;
return 0;
}
#ifdef HAVE_PAM
/*
* Useful Examples:
* http://www.kernel.org/pub/linux/libs/pam/Linux-PAM-html
* http://developer.apple.com/samplecode/CryptNoMore/index.html
*/
static int
construct_pam_passwd(int num_msg, const struct pam_message **msg,
struct pam_response **response, void *data)
{
int count = 0;
struct pam_response *reply;
char *string = (char *)data;
CRM_CHECK(data, return PAM_CONV_ERR);
CRM_CHECK(num_msg == 1, return PAM_CONV_ERR); /* We only want to handle one message */
reply = calloc(1, sizeof(struct pam_response));
CRM_ASSERT(reply != NULL);
for (count = 0; count < num_msg; ++count) {
switch (msg[count]->msg_style) {
case PAM_TEXT_INFO:
crm_info("PAM: %s\n", msg[count]->msg);
break;
case PAM_PROMPT_ECHO_OFF:
case PAM_PROMPT_ECHO_ON:
reply[count].resp_retcode = 0;
reply[count].resp = string; /* We already made a copy */
case PAM_ERROR_MSG:
/* In theory we'd want to print this, but then
* we see the password prompt in the logs
*/
/* crm_err("PAM error: %s\n", msg[count]->msg); */
break;
default:
crm_err("Unhandled conversation type: %d", msg[count]->msg_style);
goto bail;
}
}
*response = reply;
reply = NULL;
return PAM_SUCCESS;
bail:
for (count = 0; count < num_msg; ++count) {
if (reply[count].resp != NULL) {
switch (msg[count]->msg_style) {
case PAM_PROMPT_ECHO_ON:
case PAM_PROMPT_ECHO_OFF:
/* Erase the data - it contained a password */
while (*(reply[count].resp)) {
*(reply[count].resp)++ = '\0';
}
free(reply[count].resp);
break;
}
reply[count].resp = NULL;
}
}
free(reply);
reply = NULL;
return PAM_CONV_ERR;
}
#endif
int
authenticate_user(const char *user, const char *passwd)
{
#ifndef HAVE_PAM
gboolean pass = TRUE;
#else
int rc = 0;
gboolean pass = FALSE;
const void *p_user = NULL;
struct pam_conv p_conv;
struct pam_handle *pam_h = NULL;
static const char *pam_name = NULL;
if (pam_name == NULL) {
pam_name = getenv("CIB_pam_service");
}
if (pam_name == NULL) {
pam_name = "login";
}
p_conv.conv = construct_pam_passwd;
p_conv.appdata_ptr = strdup(passwd);
rc = pam_start(pam_name, user, &p_conv, &pam_h);
if (rc != PAM_SUCCESS) {
crm_err("Could not initialize PAM: %s (%d)", pam_strerror(pam_h, rc), rc);
goto bail;
}
rc = pam_authenticate(pam_h, 0);
if (rc != PAM_SUCCESS) {
crm_err("Authentication failed for %s: %s (%d)", user, pam_strerror(pam_h, rc), rc);
goto bail;
}
/* Make sure we authenticated the user we wanted to authenticate.
* Since we also run as non-root, it might be worth pre-checking
* the user has the same EID as us, since that the only user we
* can authenticate.
*/
rc = pam_get_item(pam_h, PAM_USER, &p_user);
if (rc != PAM_SUCCESS) {
crm_err("Internal PAM error: %s (%d)", pam_strerror(pam_h, rc), rc);
goto bail;
} else if (p_user == NULL) {
crm_err("Unknown user authenticated.");
goto bail;
} else if (safe_str_neq(p_user, user)) {
crm_err("User mismatch: %s vs. %s.", (const char *)p_user, (const char *)user);
goto bail;
}
rc = pam_acct_mgmt(pam_h, 0);
if (rc != PAM_SUCCESS) {
crm_err("Access denied: %s (%d)", pam_strerror(pam_h, rc), rc);
goto bail;
}
pass = TRUE;
bail:
rc = pam_end(pam_h, rc);
#endif
return pass;
}

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