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      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