FreeBSD/Linux Kernel Cross Reference
sys/net/if_clone.c
1 /*
2 * Copyright (c) 1980, 1986, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)if.c 8.3 (Berkeley) 1/4/94
30 * $FreeBSD: src/sys/net/if.c,v 1.185 2004/03/13 02:35:03 brooks Exp $
31 * $DragonFly: src/sys/net/if_clone.c,v 1.1 2008/01/11 11:59:40 sephe Exp $
32 */
33
34 #include <sys/param.h>
35 #include <sys/kernel.h>
36 #include <sys/malloc.h>
37
38 #include <net/if.h>
39 #include <net/if_clone.h>
40
41 static LIST_HEAD(, if_clone) if_cloners = LIST_HEAD_INITIALIZER(if_cloners);
42 static int if_cloners_count;
43
44 MALLOC_DEFINE(M_CLONE, "clone", "interface cloning framework");
45
46 static struct if_clone *if_clone_lookup(const char *, int *);
47
48 /*
49 * Create a clone network interface.
50 */
51 int
52 if_clone_create(char *name, int len, caddr_t params)
53 {
54 struct if_clone *ifc;
55 char *dp;
56 int wildcard, bytoff, bitoff;
57 int unit;
58 int err;
59
60 ifc = if_clone_lookup(name, &unit);
61 if (ifc == NULL)
62 return (EINVAL);
63
64 if (ifunit(name) != NULL)
65 return (EEXIST);
66
67 bytoff = bitoff = 0;
68 wildcard = (unit < 0);
69 /*
70 * Find a free unit if none was given.
71 */
72 if (wildcard) {
73 while (bytoff < ifc->ifc_bmlen &&
74 ifc->ifc_units[bytoff] == 0xff)
75 bytoff++;
76 if (bytoff >= ifc->ifc_bmlen)
77 return (ENOSPC);
78 while ((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0)
79 bitoff++;
80 unit = (bytoff << 3) + bitoff;
81 }
82
83 if (unit > ifc->ifc_maxunit)
84 return (ENXIO);
85
86 err = (*ifc->ifc_create)(ifc, unit, params);
87 if (err != 0)
88 return (err);
89
90 if (!wildcard) {
91 bytoff = unit >> 3;
92 bitoff = unit - (bytoff << 3);
93 }
94
95 /*
96 * Allocate the unit in the bitmap.
97 */
98 KASSERT((ifc->ifc_units[bytoff] & (1 << bitoff)) == 0,
99 ("%s: bit is already set", __func__));
100 ifc->ifc_units[bytoff] |= (1 << bitoff);
101
102 /* In the wildcard case, we need to update the name. */
103 if (wildcard) {
104 for (dp = name; *dp != '\0'; dp++);
105 if (ksnprintf(dp, len - (dp-name), "%d", unit) >
106 len - (dp-name) - 1) {
107 /*
108 * This can only be a programmer error and
109 * there's no straightforward way to recover if
110 * it happens.
111 */
112 panic("if_clone_create(): interface name too long");
113 }
114
115 }
116
117 EVENTHANDLER_INVOKE(if_clone_event, ifc);
118
119 return (0);
120 }
121
122 /*
123 * Destroy a clone network interface.
124 */
125 int
126 if_clone_destroy(const char *name)
127 {
128 struct if_clone *ifc;
129 struct ifnet *ifp;
130 int bytoff, bitoff;
131 int unit, error;
132
133 ifc = if_clone_lookup(name, &unit);
134 if (ifc == NULL)
135 return (EINVAL);
136
137 if (unit < ifc->ifc_minifs)
138 return (EINVAL);
139
140 ifp = ifunit(name);
141 if (ifp == NULL)
142 return (ENXIO);
143
144 if (ifc->ifc_destroy == NULL)
145 return (EOPNOTSUPP);
146
147 error = ifc->ifc_destroy(ifp);
148 if (error)
149 return error;
150
151 /*
152 * Compute offset in the bitmap and deallocate the unit.
153 */
154 bytoff = unit >> 3;
155 bitoff = unit - (bytoff << 3);
156 KASSERT((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0,
157 ("%s: bit is already cleared", __func__));
158 ifc->ifc_units[bytoff] &= ~(1 << bitoff);
159 return (0);
160 }
161
162 /*
163 * Register a network interface cloner.
164 */
165 void
166 if_clone_attach(struct if_clone *ifc)
167 {
168 int bytoff, bitoff;
169 int err;
170 int len, maxclone;
171 int unit;
172
173 KASSERT(ifc->ifc_minifs - 1 <= ifc->ifc_maxunit,
174 ("%s: %s requested more units then allowed (%d > %d)",
175 __func__, ifc->ifc_name, ifc->ifc_minifs,
176 ifc->ifc_maxunit + 1));
177 /*
178 * Compute bitmap size and allocate it.
179 */
180 maxclone = ifc->ifc_maxunit + 1;
181 len = maxclone >> 3;
182 if ((len << 3) < maxclone)
183 len++;
184 ifc->ifc_units = kmalloc(len, M_CLONE, M_WAITOK | M_ZERO);
185 ifc->ifc_bmlen = len;
186
187 LIST_INSERT_HEAD(&if_cloners, ifc, ifc_list);
188 if_cloners_count++;
189
190 for (unit = 0; unit < ifc->ifc_minifs; unit++) {
191 err = (*ifc->ifc_create)(ifc, unit, NULL);
192 KASSERT(err == 0,
193 ("%s: failed to create required interface %s%d",
194 __func__, ifc->ifc_name, unit));
195
196 /* Allocate the unit in the bitmap. */
197 bytoff = unit >> 3;
198 bitoff = unit - (bytoff << 3);
199 ifc->ifc_units[bytoff] |= (1 << bitoff);
200 }
201 }
202
203 /*
204 * Unregister a network interface cloner.
205 */
206 void
207 if_clone_detach(struct if_clone *ifc)
208 {
209
210 LIST_REMOVE(ifc, ifc_list);
211 kfree(ifc->ifc_units, M_CLONE);
212 if_cloners_count--;
213 }
214
215 /*
216 * Provide list of interface cloners to userspace.
217 */
218 int
219 if_clone_list(struct if_clonereq *ifcr)
220 {
221 char outbuf[IFNAMSIZ], *dst;
222 struct if_clone *ifc;
223 int count, error = 0;
224
225 ifcr->ifcr_total = if_cloners_count;
226 if ((dst = ifcr->ifcr_buffer) == NULL) {
227 /* Just asking how many there are. */
228 return (0);
229 }
230
231 if (ifcr->ifcr_count < 0)
232 return (EINVAL);
233
234 count = (if_cloners_count < ifcr->ifcr_count) ?
235 if_cloners_count : ifcr->ifcr_count;
236
237 for (ifc = LIST_FIRST(&if_cloners); ifc != NULL && count != 0;
238 ifc = LIST_NEXT(ifc, ifc_list), count--, dst += IFNAMSIZ) {
239 strlcpy(outbuf, ifc->ifc_name, IFNAMSIZ);
240 error = copyout(outbuf, dst, IFNAMSIZ);
241 if (error)
242 break;
243 }
244
245 return (error);
246 }
247
248 /*
249 * Look up a network interface cloner.
250 */
251 static struct if_clone *
252 if_clone_lookup(const char *name, int *unitp)
253 {
254 struct if_clone *ifc;
255 const char *cp;
256 int i;
257
258 for (ifc = LIST_FIRST(&if_cloners); ifc != NULL;) {
259 for (cp = name, i = 0; i < ifc->ifc_namelen; i++, cp++) {
260 if (ifc->ifc_name[i] != *cp)
261 goto next_ifc;
262 }
263 goto found_name;
264 next_ifc:
265 ifc = LIST_NEXT(ifc, ifc_list);
266 }
267
268 /* No match. */
269 return (NULL);
270
271 found_name:
272 if (*cp == '\0') {
273 i = -1;
274 } else {
275 for (i = 0; *cp != '\0'; cp++) {
276 if (*cp < '' || *cp > '9') {
277 /* Bogus unit number. */
278 return (NULL);
279 }
280 i = (i * 10) + (*cp - '');
281 }
282 }
283
284 if (unitp != NULL)
285 *unitp = i;
286 return (ifc);
287 }
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