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      1 /*
      2  * hostapd / VLAN netlink api
      3  * Copyright (c) 2012, Michael Braun <michael-dev (at) fami-braun.de>
      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 #include <sys/ioctl.h>
     11 #include <linux/sockios.h>
     12 #include <linux/if_vlan.h>
     13 #include <netlink/genl/genl.h>
     14 #include <netlink/genl/family.h>
     15 #include <netlink/genl/ctrl.h>
     16 #include <netlink/route/link.h>
     17 #include <netlink/route/link/vlan.h>
     18 
     19 #include "utils/common.h"
     20 #include "utils/eloop.h"
     21 #include "hostapd.h"
     22 #include "vlan_util.h"
     23 
     24 /*
     25  * Add a vlan interface with name 'vlan_if_name', VLAN ID 'vid' and
     26  * tagged interface 'if_name'.
     27  *
     28  * returns -1 on error
     29  * returns 1 if the interface already exists
     30  * returns 0 otherwise
     31 */
     32 int vlan_add(const char *if_name, int vid, const char *vlan_if_name)
     33 {
     34 	int err, ret = -1;
     35 	struct nl_sock *handle = NULL;
     36 	struct nl_cache *cache = NULL;
     37 	struct rtnl_link *rlink = NULL;
     38 	int if_idx = 0;
     39 
     40 	wpa_printf(MSG_DEBUG, "VLAN: vlan_add(if_name=%s, vid=%d, "
     41 		   "vlan_if_name=%s)", if_name, vid, vlan_if_name);
     42 
     43 	if ((os_strlen(if_name) + 1) > IFNAMSIZ) {
     44 		wpa_printf(MSG_ERROR, "VLAN: Interface name too long: '%s'",
     45 			   if_name);
     46 		return -1;
     47 	}
     48 
     49 	if ((os_strlen(vlan_if_name) + 1) > IFNAMSIZ) {
     50 		wpa_printf(MSG_ERROR, "VLAN: Interface name too long: '%s'",
     51 			   vlan_if_name);
     52 		return -1;
     53 	}
     54 
     55 	handle = nl_socket_alloc();
     56 	if (!handle) {
     57 		wpa_printf(MSG_ERROR, "VLAN: failed to open netlink socket");
     58 		goto vlan_add_error;
     59 	}
     60 
     61 	err = nl_connect(handle, NETLINK_ROUTE);
     62 	if (err < 0) {
     63 		wpa_printf(MSG_ERROR, "VLAN: failed to connect to netlink: %s",
     64 			   nl_geterror(err));
     65 		goto vlan_add_error;
     66 	}
     67 
     68 	err = rtnl_link_alloc_cache(handle, AF_UNSPEC, &cache);
     69 	if (err < 0) {
     70 		cache = NULL;
     71 		wpa_printf(MSG_ERROR, "VLAN: failed to alloc cache: %s",
     72 			   nl_geterror(err));
     73 		goto vlan_add_error;
     74 	}
     75 
     76 	if (!(if_idx = rtnl_link_name2i(cache, if_name))) {
     77 		/* link does not exist */
     78 		wpa_printf(MSG_ERROR, "VLAN: interface %s does not exist",
     79 			   if_name);
     80 		goto vlan_add_error;
     81 	}
     82 
     83 	if ((rlink = rtnl_link_get_by_name(cache, vlan_if_name))) {
     84 		/* link does exist */
     85 		rtnl_link_put(rlink);
     86 		rlink = NULL;
     87 		wpa_printf(MSG_ERROR, "VLAN: interface %s already exists",
     88 			   vlan_if_name);
     89 		ret = 1;
     90 		goto vlan_add_error;
     91 	}
     92 
     93 	rlink = rtnl_link_alloc();
     94 	if (!rlink) {
     95 		wpa_printf(MSG_ERROR, "VLAN: failed to allocate new link");
     96 		goto vlan_add_error;
     97 	}
     98 
     99 	err = rtnl_link_set_type(rlink, "vlan");
    100 	if (err < 0) {
    101 		wpa_printf(MSG_ERROR, "VLAN: failed to set link type: %s",
    102 			   nl_geterror(err));
    103 		goto vlan_add_error;
    104 	}
    105 
    106 	rtnl_link_set_link(rlink, if_idx);
    107 	rtnl_link_set_name(rlink, vlan_if_name);
    108 
    109 	err = rtnl_link_vlan_set_id(rlink, vid);
    110 	if (err < 0) {
    111 		wpa_printf(MSG_ERROR, "VLAN: failed to set link vlan id: %s",
    112 			   nl_geterror(err));
    113 		goto vlan_add_error;
    114 	}
    115 
    116 	err = rtnl_link_add(handle, rlink, NLM_F_CREATE);
    117 	if (err < 0) {
    118 		wpa_printf(MSG_ERROR, "VLAN: failed to create link %s for "
    119 			   "vlan %d on %s (%d): %s",
    120 			   vlan_if_name, vid, if_name, if_idx,
    121 			   nl_geterror(err));
    122 		goto vlan_add_error;
    123 	}
    124 
    125 	ret = 0;
    126 
    127 vlan_add_error:
    128 	if (rlink)
    129 		rtnl_link_put(rlink);
    130 	if (cache)
    131 		nl_cache_free(cache);
    132 	if (handle)
    133 		nl_socket_free(handle);
    134 	return ret;
    135 }
    136 
    137 
    138 int vlan_rem(const char *if_name)
    139 {
    140 	int err, ret = -1;
    141 	struct nl_sock *handle = NULL;
    142 	struct nl_cache *cache = NULL;
    143 	struct rtnl_link *rlink = NULL;
    144 
    145 	wpa_printf(MSG_DEBUG, "VLAN: vlan_rem(if_name=%s)", if_name);
    146 
    147 	handle = nl_socket_alloc();
    148 	if (!handle) {
    149 		wpa_printf(MSG_ERROR, "VLAN: failed to open netlink socket");
    150 		goto vlan_rem_error;
    151 	}
    152 
    153 	err = nl_connect(handle, NETLINK_ROUTE);
    154 	if (err < 0) {
    155 		wpa_printf(MSG_ERROR, "VLAN: failed to connect to netlink: %s",
    156 			   nl_geterror(err));
    157 		goto vlan_rem_error;
    158 	}
    159 
    160 	err = rtnl_link_alloc_cache(handle, AF_UNSPEC, &cache);
    161 	if (err < 0) {
    162 		cache = NULL;
    163 		wpa_printf(MSG_ERROR, "VLAN: failed to alloc cache: %s",
    164 			   nl_geterror(err));
    165 		goto vlan_rem_error;
    166 	}
    167 
    168 	if (!(rlink = rtnl_link_get_by_name(cache, if_name))) {
    169 		/* link does not exist */
    170 		wpa_printf(MSG_ERROR, "VLAN: interface %s does not exists",
    171 			   if_name);
    172 		goto vlan_rem_error;
    173 	}
    174 
    175 	err = rtnl_link_delete(handle, rlink);
    176 	if (err < 0) {
    177 		wpa_printf(MSG_ERROR, "VLAN: failed to remove link %s: %s",
    178 			   if_name, nl_geterror(err));
    179 		goto vlan_rem_error;
    180 	}
    181 
    182 	ret = 0;
    183 
    184 vlan_rem_error:
    185 	if (rlink)
    186 		rtnl_link_put(rlink);
    187 	if (cache)
    188 		nl_cache_free(cache);
    189 	if (handle)
    190 		nl_socket_free(handle);
    191 	return ret;
    192 }
    193