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/*
* RADIUS Dynamic Authorization Server (DAS) (RFC 5176)
* Copyright (c) 2012, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "includes.h"
#include <net/if.h>
#include "utils/common.h"
#include "utils/eloop.h"
#include "utils/ip_addr.h"
#include "radius.h"
#include "radius_das.h"
extern int wpa_debug_level;
struct radius_das_data {
int sock;
u8 *shared_secret;
size_t shared_secret_len;
struct hostapd_ip_addr client_addr;
unsigned int time_window;
int require_event_timestamp;
};
static void radius_das_receive(int sock, void *eloop_ctx, void *sock_ctx)
{
struct radius_das_data *das = eloop_ctx;
u8 buf[1500];
union {
struct sockaddr_storage ss;
struct sockaddr_in sin;
#ifdef CONFIG_IPV6
struct sockaddr_in6 sin6;
#endif /* CONFIG_IPV6 */
} from;
char abuf[50];
int from_port = 0;
socklen_t fromlen;
int len;
struct radius_msg *msg, *reply = NULL;
struct radius_hdr *hdr;
struct wpabuf *rbuf;
u32 val;
int res;
fromlen = sizeof(from);
len = recvfrom(sock, buf, sizeof(buf), 0,
(struct sockaddr *) &from.ss, &fromlen);
if (len < 0) {
wpa_printf(MSG_ERROR, "DAS: recvfrom: %s", strerror(errno));
return;
}
os_strlcpy(abuf, inet_ntoa(from.sin.sin_addr), sizeof(abuf));
from_port = ntohs(from.sin.sin_port);
wpa_printf(MSG_DEBUG, "DAS: Received %d bytes from %s:%d",
len, abuf, from_port);
if (das->client_addr.u.v4.s_addr != from.sin.sin_addr.s_addr) {
wpa_printf(MSG_DEBUG, "DAS: Drop message from unknown client");
return;
}
msg = radius_msg_parse(buf, len);
if (msg == NULL) {
wpa_printf(MSG_DEBUG, "DAS: Parsing incoming RADIUS packet "
"from %s:%d failed", abuf, from_port);
return;
}
if (wpa_debug_level <= MSG_MSGDUMP)
radius_msg_dump(msg);
if (radius_msg_verify_das_req(msg, das->shared_secret,
das->shared_secret_len)) {
wpa_printf(MSG_DEBUG, "DAS: Invalid authenticator in packet "
"from %s:%d - drop", abuf, from_port);
goto fail;
}
res = radius_msg_get_attr(msg, RADIUS_ATTR_EVENT_TIMESTAMP,
(u8 *) &val, 4);
if (res == 4) {
u32 timestamp = ntohl(val);
struct os_time now;
os_get_time(&now);
if (abs(now.sec - timestamp) > das->time_window) {
wpa_printf(MSG_DEBUG, "DAS: Unacceptable "
"Event-Timestamp (%u; local time %u) in "
"packet from %s:%d - drop",
timestamp, (unsigned int) now.sec,
abuf, from_port);
goto fail;
}
} else if (das->require_event_timestamp) {
wpa_printf(MSG_DEBUG, "DAS: Missing Event-Timestamp in packet "
"from %s:%d - drop", abuf, from_port);
goto fail;
}
hdr = radius_msg_get_hdr(msg);
switch (hdr->code) {
case RADIUS_CODE_DISCONNECT_REQUEST:
/* TODO */
reply = radius_msg_new(RADIUS_CODE_DISCONNECT_NAK,
hdr->identifier);
if (reply == NULL)
break;
radius_msg_add_attr_int32(reply, RADIUS_ATTR_ERROR_CAUSE, 405);
break;
case RADIUS_CODE_COA_REQUEST:
/* TODO */
reply = radius_msg_new(RADIUS_CODE_COA_NAK,
hdr->identifier);
if (reply == NULL)
break;
/* Unsupported Service */
radius_msg_add_attr_int32(reply, RADIUS_ATTR_ERROR_CAUSE, 405);
break;
default:
wpa_printf(MSG_DEBUG, "DAS: Unexpected RADIUS code %u in "
"packet from %s:%d",
hdr->code, abuf, from_port);
}
if (reply) {
wpa_printf(MSG_DEBUG, "DAS: Reply to %s:%d", abuf, from_port);
if (radius_msg_finish_das_resp(reply, das->shared_secret,
das->shared_secret_len, hdr) <
0) {
wpa_printf(MSG_DEBUG, "DAS: Failed to add "
"Message-Authenticator attribute");
}
if (wpa_debug_level <= MSG_MSGDUMP)
radius_msg_dump(reply);
rbuf = radius_msg_get_buf(reply);
res = sendto(das->sock, wpabuf_head(rbuf),
wpabuf_len(rbuf), 0,
(struct sockaddr *) &from.ss, fromlen);
if (res < 0) {
wpa_printf(MSG_ERROR, "DAS: sendto(to %s:%d): %s",
abuf, from_port, strerror(errno));
}
}
fail:
radius_msg_free(msg);
radius_msg_free(reply);
}
static int radius_das_open_socket(int port)
{
int s;
struct sockaddr_in addr;
s = socket(PF_INET, SOCK_DGRAM, 0);
if (s < 0) {
perror("socket");
return -1;
}
os_memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
perror("bind");
close(s);
return -1;
}
return s;
}
struct radius_das_data *
radius_das_init(struct radius_das_conf *conf)
{
struct radius_das_data *das;
if (conf->port == 0 || conf->shared_secret == NULL ||
conf->client_addr == NULL)
return NULL;
das = os_zalloc(sizeof(*das));
if (das == NULL)
return NULL;
das->time_window = conf->time_window;
das->require_event_timestamp = conf->require_event_timestamp;
os_memcpy(&das->client_addr, conf->client_addr,
sizeof(das->client_addr));
das->shared_secret = os_malloc(conf->shared_secret_len);
if (das->shared_secret == NULL) {
radius_das_deinit(das);
return NULL;
}
os_memcpy(das->shared_secret, conf->shared_secret,
conf->shared_secret_len);
das->shared_secret_len = conf->shared_secret_len;
das->sock = radius_das_open_socket(conf->port);
if (das->sock < 0) {
wpa_printf(MSG_ERROR, "Failed to open UDP socket for RADIUS "
"DAS");
radius_das_deinit(das);
return NULL;
}
if (eloop_register_read_sock(das->sock, radius_das_receive, das, NULL))
{
radius_das_deinit(das);
return NULL;
}
return das;
}
void radius_das_deinit(struct radius_das_data *das)
{
if (das == NULL)
return;
if (das->sock >= 0) {
eloop_unregister_read_sock(das->sock);
close(das->sock);
}
os_free(das->shared_secret);
os_free(das);
}
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