x_snoop.c revision 1.1.1.1 
1/*
2 * Generic Snooping for Proxy ARP
3 * Copyright (c) 2014, Qualcomm Atheros, Inc.
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9#include "utils/includes.h"
10
11#include "utils/common.h"
12#include "hostapd.h"
13#include "sta_info.h"
14#include "ap_drv_ops.h"
15#include "x_snoop.h"
16
17
18int x_snoop_init(struct hostapd_data *hapd)
19{
20	struct hostapd_bss_config *conf = hapd->conf;
21
22	if (!conf->isolate) {
23		wpa_printf(MSG_DEBUG,
24			   "x_snoop: ap_isolate must be enabled for x_snoop");
25		return -1;
26	}
27
28	if (conf->bridge[0] == '\0') {
29		wpa_printf(MSG_DEBUG,
30			   "x_snoop: Bridge must be configured for x_snoop");
31		return -1;
32	}
33
34	if (hostapd_drv_br_port_set_attr(hapd, DRV_BR_PORT_ATTR_HAIRPIN_MODE,
35					 1)) {
36		wpa_printf(MSG_DEBUG,
37			   "x_snoop: Failed to enable hairpin_mode on the bridge port");
38		return -1;
39	}
40
41	if (hostapd_drv_br_port_set_attr(hapd, DRV_BR_PORT_ATTR_PROXYARP, 1)) {
42		wpa_printf(MSG_DEBUG,
43			   "x_snoop: Failed to enable proxyarp on the bridge port");
44		return -1;
45	}
46
47	if (hostapd_drv_br_set_net_param(hapd, DRV_BR_NET_PARAM_GARP_ACCEPT,
48					 1)) {
49		wpa_printf(MSG_DEBUG,
50			   "x_snoop: Failed to enable accepting gratuitous ARP on the bridge");
51		return -1;
52	}
53
54	return 0;
55}
56
57
58struct l2_packet_data *
59x_snoop_get_l2_packet(struct hostapd_data *hapd,
60		      void (*handler)(void *ctx, const u8 *src_addr,
61				      const u8 *buf, size_t len),
62		      enum l2_packet_filter_type type)
63{
64	struct hostapd_bss_config *conf = hapd->conf;
65	struct l2_packet_data *l2;
66
67	l2 = l2_packet_init(conf->bridge, NULL, ETH_P_ALL, handler, hapd, 1);
68	if (l2 == NULL) {
69		wpa_printf(MSG_DEBUG,
70			   "x_snoop: Failed to initialize L2 packet processing %s",
71			   strerror(errno));
72		return NULL;
73	}
74
75	if (l2_packet_set_packet_filter(l2, type)) {
76		wpa_printf(MSG_DEBUG,
77			   "x_snoop: Failed to set L2 packet filter for type: %d",
78			   type);
79		l2_packet_deinit(l2);
80		return NULL;
81	}
82
83	return l2;
84}
85
86
87void x_snoop_mcast_to_ucast_convert_send(struct hostapd_data *hapd,
88					 struct sta_info *sta, u8 *buf,
89					 size_t len)
90{
91	int res;
92	u8 addr[ETH_ALEN];
93	u8 *dst_addr = buf;
94
95	if (!(dst_addr[0] & 0x01))
96		return;
97
98	wpa_printf(MSG_EXCESSIVE, "x_snoop: Multicast-to-unicast conversion "
99		   MACSTR " -> " MACSTR " (len %u)",
100		   MAC2STR(dst_addr), MAC2STR(sta->addr), (unsigned int) len);
101
102	/* save the multicast destination address for restoring it later */
103	os_memcpy(addr, buf, ETH_ALEN);
104
105	os_memcpy(buf, sta->addr, ETH_ALEN);
106	res = l2_packet_send(hapd->sock_dhcp, NULL, 0, buf, len);
107	if (res < 0) {
108		wpa_printf(MSG_DEBUG,
109			   "x_snoop: Failed to send mcast to ucast converted packet to "
110			   MACSTR, MAC2STR(sta->addr));
111	}
112
113	/* restore the multicast destination address */
114	os_memcpy(buf, addr, ETH_ALEN);
115}
116
117
118void x_snoop_deinit(struct hostapd_data *hapd)
119{
120	hostapd_drv_br_set_net_param(hapd, DRV_BR_NET_PARAM_GARP_ACCEPT, 0);
121	hostapd_drv_br_port_set_attr(hapd, DRV_BR_PORT_ATTR_PROXYARP, 0);
122	hostapd_drv_br_port_set_attr(hapd, DRV_BR_PORT_ATTR_HAIRPIN_MODE, 0);
123}
124