vlan_util.c revision 289549 
1/*
2 * hostapd / VLAN netlink api
3 * Copyright (c) 2012, Michael Braun <michael-dev@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*/
32int 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
127vlan_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
138int 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
184vlan_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