src/ap/x_snoop.c

   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 }