xref: /freebsd/contrib/wpa/src/ap/x_snoop.c (revision 895f86f15fbf6540071feb9328c3c50ed1f027b8)
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 
18 int 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 #ifdef CONFIG_IPV6
55 	if (hostapd_drv_br_set_net_param(hapd, DRV_BR_MULTICAST_SNOOPING, 1)) {
56 		wpa_printf(MSG_DEBUG,
57 			   "x_snoop: Failed to enable multicast snooping on the bridge");
58 		return -1;
59 	}
60 #endif /* CONFIG_IPV6 */
61 
62 	return 0;
63 }
64 
65 
66 struct l2_packet_data *
67 x_snoop_get_l2_packet(struct hostapd_data *hapd,
68 		      void (*handler)(void *ctx, const u8 *src_addr,
69 				      const u8 *buf, size_t len),
70 		      enum l2_packet_filter_type type)
71 {
72 	struct hostapd_bss_config *conf = hapd->conf;
73 	struct l2_packet_data *l2;
74 
75 	l2 = l2_packet_init(conf->bridge, NULL, ETH_P_ALL, handler, hapd, 1);
76 	if (l2 == NULL) {
77 		wpa_printf(MSG_DEBUG,
78 			   "x_snoop: Failed to initialize L2 packet processing %s",
79 			   strerror(errno));
80 		return NULL;
81 	}
82 
83 	if (l2_packet_set_packet_filter(l2, type)) {
84 		wpa_printf(MSG_DEBUG,
85 			   "x_snoop: Failed to set L2 packet filter for type: %d",
86 			   type);
87 		l2_packet_deinit(l2);
88 		return NULL;
89 	}
90 
91 	return l2;
92 }
93 
94 
95 void x_snoop_mcast_to_ucast_convert_send(struct hostapd_data *hapd,
96 					 struct sta_info *sta, u8 *buf,
97 					 size_t len)
98 {
99 	int res;
100 	u8 addr[ETH_ALEN];
101 	u8 *dst_addr = buf;
102 
103 	if (!(dst_addr[0] & 0x01))
104 		return;
105 
106 	wpa_printf(MSG_EXCESSIVE, "x_snoop: Multicast-to-unicast conversion "
107 		   MACSTR " -> " MACSTR " (len %u)",
108 		   MAC2STR(dst_addr), MAC2STR(sta->addr), (unsigned int) len);
109 
110 	/* save the multicast destination address for restoring it later */
111 	os_memcpy(addr, buf, ETH_ALEN);
112 
113 	os_memcpy(buf, sta->addr, ETH_ALEN);
114 	res = l2_packet_send(hapd->sock_dhcp, NULL, 0, buf, len);
115 	if (res < 0) {
116 		wpa_printf(MSG_DEBUG,
117 			   "x_snoop: Failed to send mcast to ucast converted packet to "
118 			   MACSTR, MAC2STR(sta->addr));
119 	}
120 
121 	/* restore the multicast destination address */
122 	os_memcpy(buf, addr, ETH_ALEN);
123 }
124 
125 
126 void x_snoop_deinit(struct hostapd_data *hapd)
127 {
128 	hostapd_drv_br_set_net_param(hapd, DRV_BR_NET_PARAM_GARP_ACCEPT, 0);
129 	hostapd_drv_br_port_set_attr(hapd, DRV_BR_PORT_ATTR_PROXYARP, 0);
130 	hostapd_drv_br_port_set_attr(hapd, DRV_BR_PORT_ATTR_HAIRPIN_MODE, 0);
131 }
132