xref: /netbsd-src/sys/rump/net/lib/libvirtif/if_virt.c (revision b5677b36047b601b9addaaa494a58ceae82c2a6c)
1 /*	$NetBSD: if_virt.c,v 1.8 2009/03/27 13:46:35 pooka Exp $	*/
2 
3 /*
4  * Copyright (c) 2008 Antti Kantee.  All Rights Reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
16  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: if_virt.c,v 1.8 2009/03/27 13:46:35 pooka Exp $");
30 
31 #include <sys/param.h>
32 #include <sys/condvar.h>
33 #include <sys/fcntl.h>
34 #include <sys/kmem.h>
35 #include <sys/kthread.h>
36 #include <sys/mutex.h>
37 #include <sys/sockio.h>
38 #include <sys/socketvar.h>
39 
40 #include <net/if.h>
41 #include <net/if_ether.h>
42 #include <net/if_tap.h>
43 
44 #include <netinet/in.h>
45 #include <netinet/in_var.h>
46 
47 #include <rump/rump.h>
48 #include <rump/rumpuser.h>
49 
50 #include "rump_private.h"
51 
52 /*
53  * Virtual interface for userspace purposes.  Uses tap(4) to
54  * interface with the kernel and just simply shovels data
55  * to/from /dev/tap.
56  */
57 
58 #define VIRTIF_BASE "virt"
59 
60 static int	virtif_init(struct ifnet *);
61 static int	virtif_ioctl(struct ifnet *, u_long, void *);
62 static void	virtif_start(struct ifnet *);
63 static void	virtif_stop(struct ifnet *, int);
64 
65 struct virtif_sc {
66 	struct ethercom sc_ec;
67 	int sc_tapfd;
68 	kmutex_t sc_sendmtx;
69 	kcondvar_t sc_sendcv;
70 };
71 
72 static void virtif_worker(void *);
73 static void virtif_sender(void *);
74 
75 #if 0
76 /*
77  * Create a socket and call ifioctl() to configure the interface.
78  * This trickles down to virtif_ioctl().
79  */
80 static int
81 configaddr(struct ifnet *ifp, struct ifaliasreq *ia)
82 {
83 	struct socket *so;
84 	int error;
85 
86 	strcpy(ia->ifra_name, ifp->if_xname);
87 	error = socreate(ia->ifra_addr.sa_family, &so, SOCK_DGRAM,
88 	    0, curlwp, NULL);
89 	if (error)
90 		return error;
91 	error = ifioctl(so, SIOCAIFADDR, ia, curlwp);
92 	soclose(so);
93 
94 	return error;
95 }
96 #endif
97 
98 int
99 rump_virtif_create(int num)
100 {
101 	struct virtif_sc *sc;
102 	struct ifnet *ifp;
103 	uint8_t enaddr[ETHER_ADDR_LEN] = { 0xb2, 0x0a, 0x00, 0x0b, 0x0e, 0x01 };
104 	char tapdev[16];
105 	int fd, error;
106 
107 	snprintf(tapdev, sizeof(tapdev), "/dev/tap%d", num);
108 	fd = rumpuser_open(tapdev, O_RDWR, &error);
109 	if (fd == -1) {
110 		printf("virtif_create: can't open /dev/tap %d\n", error);
111 		return error;
112 	}
113 	KASSERT(num < 0x100);
114 	enaddr[2] = arc4random() & 0xff;
115 	enaddr[5] = num;
116 
117 	sc = kmem_zalloc(sizeof(*sc), KM_SLEEP);
118 	sc->sc_tapfd = fd;
119 
120 	ifp = &sc->sc_ec.ec_if;
121 	sprintf(ifp->if_xname, "%s%d", VIRTIF_BASE, num);
122 	ifp->if_softc = sc;
123 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
124 	ifp->if_init = virtif_init;
125 	ifp->if_ioctl = virtif_ioctl;
126 	ifp->if_start = virtif_start;
127 	ifp->if_stop = virtif_stop;
128 
129 	mutex_init(&sc->sc_sendmtx, MUTEX_DEFAULT, IPL_NONE);
130 	cv_init(&sc->sc_sendcv, "virtsnd");
131 
132 	if_attach(ifp);
133 	ether_ifattach(ifp, enaddr);
134 
135 	return 0;
136 }
137 
138 static int
139 virtif_init(struct ifnet *ifp)
140 {
141 	int rv;
142 
143 	if (rump_threads) {
144 		rv = kthread_create(PRI_NONE, 0, NULL, virtif_worker, ifp,
145 		    NULL, "virtifi");
146 		/* XXX: should do proper cleanup */
147 		if (rv) {
148 			panic("if_virt: can't create worker");
149 		}
150 		rv = kthread_create(PRI_NONE, 0, NULL, virtif_sender, ifp,
151 		    NULL, "virtifs");
152 		if (rv) {
153 			panic("if_virt: can't create sender");
154 		}
155 	} else {
156 		printf("WARNING: threads not enabled, receive NOT working\n");
157 	}
158 	ifp->if_flags |= IFF_RUNNING;
159 
160 	return 0;
161 }
162 
163 static int
164 virtif_ioctl(struct ifnet *ifp, u_long cmd, void *data)
165 {
166 	int s, rv;
167 
168 	s = splnet();
169 	rv = ether_ioctl(ifp, cmd, data);
170 	splx(s);
171 
172 	return rv;
173 }
174 
175 /* just send everything in-context */
176 static void
177 virtif_start(struct ifnet *ifp)
178 {
179 	struct virtif_sc *sc = ifp->if_softc;
180 
181 	mutex_enter(&sc->sc_sendmtx);
182 	cv_signal(&sc->sc_sendcv);
183 	mutex_exit(&sc->sc_sendmtx);
184 }
185 
186 static void
187 virtif_stop(struct ifnet *ifp, int disable)
188 {
189 
190 	panic("%s: unimpl", __func__);
191 }
192 
193 static void
194 virtif_worker(void *arg)
195 {
196 	struct ifnet *ifp = arg;
197 	struct virtif_sc *sc = ifp->if_softc;
198 	struct mbuf *m;
199 	size_t plen = ETHER_MAX_LEN_JUMBO+1;
200 	ssize_t n;
201 	int error;
202 
203 	for (;;) {
204 		m = m_gethdr(M_WAIT, MT_DATA);
205 		MEXTMALLOC(m, plen, M_WAIT);
206 
207 		n = rumpuser_read(sc->sc_tapfd, mtod(m, void *), plen, &error);
208 		KASSERT(n < ETHER_MAX_LEN_JUMBO);
209 		if (n <= 0) {
210 			m_freem(m);
211 			break;
212 		}
213 		m->m_len = m->m_pkthdr.len = n;
214 		m->m_pkthdr.rcvif = ifp;
215 		ether_input(ifp, m);
216 	}
217 
218 	panic("virtif_workin is a lazy boy %d\n", error);
219 }
220 
221 static void
222 virtif_sender(void *arg)
223 {
224 	struct ifnet *ifp = arg;
225 	struct virtif_sc *sc = ifp->if_softc;
226 	struct mbuf *m, *m0;
227 	struct rumpuser_iovec io[16];
228 	int i, error;
229 
230 	mutex_enter(&sc->sc_sendmtx);
231 	for (;;) {
232 		IF_DEQUEUE(&ifp->if_snd, m0);
233 		if (!m0) {
234 			cv_wait(&sc->sc_sendcv, &sc->sc_sendmtx);
235 			continue;
236 		}
237 		mutex_exit(&sc->sc_sendmtx);
238 
239 		m = m0;
240 		for (i = 0; i < 16 && m; i++) {
241 			io[i].iov_base = mtod(m, void *);
242 			io[i].iov_len = m->m_len;
243 			m = m->m_next;
244 		}
245 		if (i == 16)
246 			panic("lazy bum");
247 		rumpuser_writev(sc->sc_tapfd, io, i, &error);
248 		m_freem(m0);
249 		mutex_enter(&sc->sc_sendmtx);
250 	}
251 
252 	mutex_exit(softnet_lock);
253 }
254