if_canloop.c revision 1.1.2.6 1 /* $NetBSD: if_canloop.c,v 1.1.2.6 2017/04/24 13:38:33 bouyer Exp $ */
2
3 /*-
4 * Copyright (c) 2017 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Manuel Bouyer.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32
33 /*
34 * Loopback interface driver for the CAN protocol
35 */
36
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(0, "$NetBSD: if_canloop.c,v 1.1.2.6 2017/04/24 13:38:33 bouyer Exp $");
39
40 #ifdef _KERNEL_OPT
41 #include "opt_can.h"
42 #include "opt_net_mpsafe.h"
43 #endif
44
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
48 #include <sys/mbuf.h>
49 #include <sys/socket.h>
50 #include <sys/errno.h>
51 #include <sys/ioctl.h>
52 #include <sys/time.h>
53 #include <sys/device.h>
54 #include <sys/module.h>
55
56 #include <sys/cpu.h>
57
58 #include <net/if.h>
59 #include <net/if_types.h>
60 #include <net/netisr.h>
61
62 #ifdef CAN
63 #include <netcan/can.h>
64 #endif
65 #include <net/bpf.h>
66
67 void canloopattach(int);
68 void canloopinit(void);
69 static int canloop_clone_create(struct if_clone *, int);
70 static int canloop_clone_destroy(struct ifnet *);
71 static int canloop_ioctl(struct ifnet *, u_long, void *);
72 static void canloop_ifstart(struct ifnet *);
73
74 static int canloop_count;
75
76 static struct if_clone canloop_cloner =
77 IF_CLONE_INITIALIZER("canlo", canloop_clone_create, canloop_clone_destroy);
78
79 void
80 canloopattach(int n)
81 {
82
83 /*
84 * Nothing to do here, initialization is handled by the
85 * module initialization code in canloopinit() below).
86 */
87 }
88
89 void
90 canloopinit(void)
91 {
92
93 canloop_count = 0;
94 if_clone_attach(&canloop_cloner);
95 }
96
97 static int
98 canloopdetach(void)
99 {
100 if (canloop_count > 0)
101 return EBUSY;
102 if_clone_detach(&canloop_cloner);
103 return 0;
104 }
105
106 static int
107 canloop_clone_create(struct if_clone *ifc, int unit)
108 {
109 struct ifnet *ifp;
110
111 ifp = if_alloc(IFT_OTHER);
112
113 if_initname(ifp, ifc->ifc_name, unit);
114
115 ifp->if_flags = IFF_LOOPBACK | IFF_RUNNING;
116 ifp->if_extflags = IFEF_OUTPUT_MPSAFE;
117 ifp->if_ioctl = canloop_ioctl;
118 ifp->if_start = canloop_ifstart;
119 if_attach(ifp);
120 can_ifattach(ifp);
121 bpf_attach(ifp, DLT_CAN_SOCKETCAN, 0);
122 #ifdef MBUFTRACE
123 ifp->if_mowner = malloc(sizeof(struct mowner), M_DEVBUF,
124 M_WAITOK | M_ZERO);
125 strlcpy(ifp->if_mowner->mo_name, ifp->if_xname,
126 sizeof(ifp->if_mowner->mo_name));
127 MOWNER_ATTACH(ifp->if_mowner);
128 #endif
129 canloop_count++;
130
131 return (0);
132 }
133
134 static int
135 canloop_clone_destroy(struct ifnet *ifp)
136 {
137
138 #ifdef MBUFTRACE
139 MOWNER_DETACH(ifp->if_mowner);
140 free(ifp->if_mowner, M_DEVBUF);
141 #endif
142
143 bpf_detach(ifp);
144 if_detach(ifp);
145
146 if_free(ifp);
147 canloop_count--;
148 KASSERT(canloop_count >= 0);
149 return (0);
150 }
151
152 static void
153 canloop_ifstart(struct ifnet *ifp)
154 {
155 size_t pktlen;
156 struct mbuf *m;
157
158 KERNEL_LOCK(1, NULL);
159 while (true) {
160 IF_DEQUEUE(&ifp->if_snd, m);
161 if (m == NULL)
162 break;
163 MCLAIM(m, ifp->if_mowner);
164
165 if ((m->m_flags & M_PKTHDR) == 0)
166 panic("canloop_output: no header mbuf");
167 m_set_rcvif(m, ifp);
168 if (ifp->if_flags & IFF_LOOPBACK)
169 bpf_mtap(ifp, m);
170
171 pktlen = m->m_pkthdr.len;
172 ifp->if_opackets++;
173 ifp->if_obytes += pktlen;
174
175 #ifdef CAN
176 can_mbuf_tag_clean(m);
177 can_input(ifp, m);
178 #else
179 printf("%s: can't handle CAN packet\n", ifp->if_xname);
180 m_freem(m);
181 #endif
182 }
183
184 KERNEL_UNLOCK_ONE(NULL);
185 }
186
187 /*
188 * Process an ioctl request.
189 */
190 /* ARGSUSED */
191 static int
192 canloop_ioctl(struct ifnet *ifp, u_long cmd, void *data)
193 {
194 struct ifreq *ifr = data;
195 int error = 0;
196
197 switch (cmd) {
198
199 case SIOCINITIFADDR:
200 error = EAFNOSUPPORT;
201 break;
202
203 case SIOCSIFMTU:
204 if ((unsigned)ifr->ifr_mtu != sizeof(struct can_frame))
205 error = EINVAL;
206 break;
207
208 case SIOCADDMULTI:
209 case SIOCDELMULTI:
210 error = EAFNOSUPPORT;
211 break;
212
213 default:
214 error = ifioctl_common(ifp, cmd, data);
215 }
216 return (error);
217 }
218
219 /*
220 * Module infrastructure
221 */
222 #include "../net/if_module.h"
223
224 IF_MODULE(MODULE_CLASS_DRIVER, canloop, "")
225