xref: /netbsd-src/sys/rump/net/lib/libvirtif/if_virt.c (revision 466a16a118933bd295a8a104f095714fadf9cf68)
1 /*	$NetBSD: if_virt.c,v 1.5 2008/12/18 00:24:13 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 1.5 2008/12/18 00:24:13 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 static int nunits;
60 
61 static int	virtif_init(struct ifnet *);
62 static int	virtif_ioctl(struct ifnet *, u_long, void *);
63 static void	virtif_start(struct ifnet *);
64 static void	virtif_stop(struct ifnet *, int);
65 
66 struct virtif_sc {
67 	struct ifnet sc_if;
68 	char sc_tapname[IFNAMSIZ];
69 	int sc_tapfd;
70 };
71 
72 static int virtif_create(struct ifaliasreq *, struct ifnet **);
73 static void virtif_worker(void *);
74 
75 /* XXXXX: this prototype needs to go elsewhere */
76 int rump_virtif_create(struct ifaliasreq *, struct ifnet **);
77 int
78 rump_virtif_create(struct ifaliasreq *ia, struct ifnet **ifpp)
79 {
80 
81 	return virtif_create(ia, ifpp);
82 }
83 
84 /*
85  * Create a socket and call ifioctl() to configure the interface.
86  * This trickles down to virtif_ioctl().
87  */
88 static int
89 configaddr(struct ifnet *ifp, struct ifaliasreq *ia)
90 {
91 	struct socket *so;
92 	int error;
93 
94 	strcpy(ia->ifra_name, ifp->if_xname);
95 	error = socreate(ia->ifra_addr.sa_family, &so, SOCK_DGRAM,
96 	    0, curlwp, NULL);
97 	if (error)
98 		return error;
99 	error = ifioctl(so, SIOCAIFADDR, ia, curlwp);
100 	soclose(so);
101 
102 	return error;
103 }
104 
105 static int
106 virtif_create(struct ifaliasreq *ia, struct ifnet **ifpp)
107 {
108 	struct virtif_sc *sc;
109 	struct ifreq ifr;
110 	struct ifnet *ifp;
111 	uint8_t enaddr[ETHER_ADDR_LEN] = { 0xb2, 0x0a, 0x00, 0x0b, 0x0e, 0x01 };
112 	int fd, rv, error;
113 	int mynum;
114 
115 	/*
116 	 * XXX: this is currently un-sane.  Need to figure out a way
117 	 * to configure this with a bridge into a sane network without
118 	 * hardcoding it.
119 	 */
120 	fd = rumpuser_open("/dev/tap0", O_RDWR, &error);
121 	if (fd == -1) {
122 		printf("virtif_create: can't open /dev/tap %d\n", error);
123 		return error;
124 	}
125 
126 	sc = kmem_zalloc(sizeof(*sc), KM_SLEEP);
127 	rv = rumpuser_ioctl(fd, TAPGIFNAME, &ifr, &error);
128 	if (rv == -1) {
129 		kmem_free(sc, sizeof(*sc));
130 		return error;
131 	}
132 	strlcpy(sc->sc_tapname, ifr.ifr_name, IFNAMSIZ);
133 	sc->sc_tapfd = fd;
134 
135 	ifp = &sc->sc_if;
136 	mynum = nunits++;
137 	sprintf(ifp->if_xname, "%s%d", VIRTIF_BASE, mynum);
138 	ifp->if_softc = sc;
139 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
140 	ifp->if_init = virtif_init;
141 	ifp->if_ioctl = virtif_ioctl;
142 	ifp->if_start = virtif_start;
143 	ifp->if_stop = virtif_stop;
144 
145 	if (rump_threads) {
146 		rv = kthread_create(PRI_NONE, 0, NULL, virtif_worker, ifp,
147 		    NULL, "virtifi");
148 		if (rv) {
149 			kmem_free(sc, sizeof(*sc));
150 			return rv;
151 		}
152 	} else {
153 		printf("WARNING: threads not enabled, receive NOT working\n");
154 	}
155 
156 	if_attach(ifp);
157 	ether_ifattach(ifp, enaddr);
158 
159 	if (ia)
160 		configaddr(ifp, ia);
161 	if (ifpp)
162 		*ifpp = ifp;
163 
164 	return 0;
165 }
166 
167 static int
168 virtif_init(struct ifnet *ifp)
169 {
170 
171 	ifp->if_flags |= IFF_RUNNING;
172 
173 	return 0;
174 }
175 
176 static int
177 virtif_ioctl(struct ifnet *ifp, u_long cmd, void *data)
178 {
179 	int s, rv;
180 
181 	s = splnet();
182 	rv = ether_ioctl(ifp, cmd, data);
183 	splx(s);
184 
185 	return rv;
186 }
187 
188 /* just send everything in-context */
189 static void
190 virtif_start(struct ifnet *ifp)
191 {
192 	struct virtif_sc *sc = ifp->if_softc;
193 	struct iovec io[16];
194 	struct mbuf *m, *m0;
195 	int s, i, error;
196 
197 	s = splnet();
198 	for (;;) {
199 		IF_DEQUEUE(&ifp->if_snd, m0);
200 		if (!m0)
201 			break;
202 		splx(s);
203 
204 		m = m0;
205 		for (i = 0; i < 16 && m; i++) {
206 			io[i].iov_base = mtod(m, void *);
207 			io[i].iov_len = m->m_len;
208 			m = m->m_next;
209 		}
210 		if (i == 16)
211 			panic("lazy bum");
212 		rumpuser_writev(sc->sc_tapfd, io, i, &error);
213 		m_freem(m0);
214 		s = splnet();
215 	}
216 
217 	ifp->if_flags &= ~IFF_OACTIVE;
218 	splx(s);
219 }
220 
221 static void
222 virtif_stop(struct ifnet *ifp, int disable)
223 {
224 
225 	panic("%s: unimpl", __func__);
226 }
227 
228 static void
229 virtif_worker(void *arg)
230 {
231 	struct ifnet *ifp = arg;
232 	struct virtif_sc *sc = ifp->if_softc;
233 	struct mbuf *m;
234 	size_t plen = ETHER_MAX_LEN_JUMBO+1;
235 	ssize_t n;
236 	int error;
237 
238 	for (;;) {
239 		m = m_gethdr(M_WAIT, MT_DATA);
240 		MEXTMALLOC(m, plen, M_WAIT);
241 
242 		n = rumpuser_read(sc->sc_tapfd, mtod(m, void *), plen, &error);
243 		KASSERT(n < ETHER_MAX_LEN_JUMBO);
244 		if (n <= 0) {
245 			m_freem(m);
246 			break;
247 		}
248 		m->m_len = m->m_pkthdr.len = n;
249 		m->m_pkthdr.rcvif = ifp;
250 		ether_input(ifp, m);
251 	}
252 
253 	panic("virtif_workin is a lazy boy %d\n", error);
254 }
255