xref: /freebsd/contrib/wpa/src/ap/x_snoop.c (revision 6ae1554a5d9b318f8ad53ccc39fa5a961403da73)
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 	return 0;
55 }
56 
57 
58 struct l2_packet_data *
59 x_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 
87 void 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 
118 void 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