1/*	$NetBSD: nfs_diskless.c,v 1.2 2016/12/13 22:41:46 pgoyette Exp $	*/
2/*-
3 * Copyright (c) 1990 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * William Jolitz.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *	from: @(#)autoconf.c	7.1 (Berkeley) 5/9/91
34 */
35
36#include <sys/cdefs.h>
37/* __FBSDID("FreeBSD: head/sys/nfs/nfs_diskless.c 297086 2016-03-20 21:48:26Z ian "); */
38__RCSID("$NetBSD: nfs_diskless.c,v 1.2 2016/12/13 22:41:46 pgoyette Exp $");
39
40#ifdef _KERNEL_OPT
41#include "opt_newnfs.h"
42#endif
43
44#include <sys/param.h>
45#include <sys/systm.h>
46#include <sys/jail.h>
47#include <sys/kernel.h>
48#include <sys/malloc.h>
49#include <sys/mount.h>
50#include <sys/socket.h>
51
52#include <net/if.h>
53#include <net/if_dl.h>
54#include <net/if_types.h>
55
56#include <net/if_var.h>
57#include <net/ethernet.h>
58#include <net/vnet.h>
59
60#include <netinet/in.h>
61
62#include <fs/nfs/common/nfsproto.h>
63#include <fs/nfs/client/nfs.h>
64#include <fs/nfs/common/nfsdiskless.h>
65
66#define	NFS_IFACE_TIMEOUT_SECS	10 /* Timeout for interface to appear. */
67
68static int inaddr_to_sockaddr(char *ev, struct sockaddr_in *sa);
69static int hwaddr_to_sockaddr(char *ev, struct sockaddr_dl *sa);
70static int decode_nfshandle(char *ev, u_char *fh, int maxfh);
71
72/*
73 * This structure must be filled in by a primary bootstrap or bootstrap
74 * server for a diskless/dataless machine. It is initialized below just
75 * to ensure that it is allocated to initialized data (.data not .bss).
76 */
77struct nfs_diskless	nfs_diskless = { { { 0 } } };
78struct nfsv3_diskless	nfsv3_diskless = { { { 0 } } };
79int			nfs_diskless_valid = 0;
80
81/*
82 * Validate/sanity check a rsize/wsize parameter.
83 */
84static int
85checkrwsize(unsigned long v, const char *name)
86{
87	/*
88	 * 32K is used as an upper bound because most servers
89	 * limit block size to satisfy IPv4's limit of
90	 * 64K/reassembled packet.  The lower bound is pretty
91	 * much arbitrary.
92	 */
93	if (!(4 <= v && v <= 32*1024)) {
94		printf("nfs_parse_options: invalid %s %lu ignored\n", name, v);
95		return 0;
96	} else
97		return 1;
98}
99
100/*
101 * Parse mount options and apply them to the supplied
102 * nfs_diskless state.  Used also by bootp/dhcp support.
103 */
104void
105nfs_parse_options(const char *envopts, struct nfs_args *nd)
106{
107	char *opts, *o, *otmp;
108	unsigned long v;
109
110	opts = strdup(envopts, M_TEMP);
111	otmp = opts;
112	while ((o = strsep(&otmp, ":;, ")) != NULL) {
113		if (*o == '\0')
114			; /* Skip empty options. */
115		else if (strcmp(o, "soft") == 0)
116			nd->flags |= NFSMNT_SOFT;
117		else if (strcmp(o, "intr") == 0)
118			nd->flags |= NFSMNT_INT;
119		else if (strcmp(o, "conn") == 0)
120			nd->flags |= NFSMNT_NOCONN;
121		else if (strcmp(o, "nolockd") == 0)
122			nd->flags |= NFSMNT_NOLOCKD;
123		else if (strcmp(o, "nocto") == 0)
124			nd->flags |= NFSMNT_NOCTO;
125		else if (strcmp(o, "nfsv2") == 0)
126			nd->flags &= ~(NFSMNT_NFSV3 | NFSMNT_NFSV4);
127		else if (strcmp(o, "nfsv3") == 0) {
128			nd->flags &= ~NFSMNT_NFSV4;
129			nd->flags |= NFSMNT_NFSV3;
130		} else if (strcmp(o, "tcp") == 0)
131			nd->sotype = SOCK_STREAM;
132		else if (strcmp(o, "udp") == 0)
133			nd->sotype = SOCK_DGRAM;
134		else if (strncmp(o, "rsize=", 6) == 0) {
135			v = strtoul(o+6, NULL, 10);
136			if (checkrwsize(v, "rsize")) {
137				nd->rsize = (int) v;
138				nd->flags |= NFSMNT_RSIZE;
139			}
140		} else if (strncmp(o, "wsize=", 6) == 0) {
141			v = strtoul(o+6, NULL, 10);
142			if (checkrwsize(v, "wsize")) {
143				nd->wsize = (int) v;
144				nd->flags |= NFSMNT_WSIZE;
145			}
146		} else
147			printf("%s: skipping unknown option \"%s\"\n",
148			    __func__, o);
149	}
150	free(opts, M_TEMP);
151}
152
153/*
154 * Populate the essential fields in the nfsv3_diskless structure.
155 *
156 * The loader is expected to export the following environment variables:
157 *
158 * boot.netif.name		name of boot interface
159 * boot.netif.ip		IP address on boot interface
160 * boot.netif.netmask		netmask on boot interface
161 * boot.netif.gateway		default gateway (optional)
162 * boot.netif.hwaddr		hardware address of boot interface
163 * boot.netif.mtu		interface mtu from bootp/dhcp (optional)
164 * boot.nfsroot.server		IP address of root filesystem server
165 * boot.nfsroot.path		path of the root filesystem on server
166 * boot.nfsroot.nfshandle	NFS handle for root filesystem on server
167 * boot.nfsroot.nfshandlelen	and length of this handle (for NFSv3 only)
168 * boot.nfsroot.options		NFS options for the root filesystem
169 */
170void
171nfs_setup_diskless(void)
172{
173	struct nfs_diskless *nd = &nfs_diskless;
174	struct nfsv3_diskless *nd3 = &nfsv3_diskless;
175	struct ifnet *ifp;
176	struct ifaddr *ifa;
177	struct sockaddr_dl *sdl, ourdl;
178	struct sockaddr_in myaddr, netmask;
179	char *cp;
180	int cnt, fhlen, is_nfsv3;
181	uint32_t len;
182	time_t timeout_at;
183
184	if (nfs_diskless_valid != 0)
185		return;
186
187	/* get handle size. If this succeeds, it's an NFSv3 setup. */
188	if ((cp = kern_getenv("boot.nfsroot.nfshandlelen")) != NULL) {
189		cnt = sscanf(cp, "%d", &len);
190		freeenv(cp);
191		if (cnt != 1 || len == 0 || len > NFSX_V3FHMAX) {
192			printf("nfs_diskless: bad NFS handle len\n");
193			return;
194		}
195		nd3->root_fhsize = len;
196		is_nfsv3 = 1;
197	} else
198		is_nfsv3 = 0;
199	/* set up interface */
200	if (inaddr_to_sockaddr("boot.netif.ip", &myaddr))
201		return;
202	if (inaddr_to_sockaddr("boot.netif.netmask", &netmask)) {
203		printf("nfs_diskless: no netmask\n");
204		return;
205	}
206	if (is_nfsv3 != 0) {
207		bcopy(&myaddr, &nd3->myif.ifra_addr, sizeof(myaddr));
208		bcopy(&myaddr, &nd3->myif.ifra_broadaddr, sizeof(myaddr));
209		((struct sockaddr_in *)
210		   &nd3->myif.ifra_broadaddr)->sin_addr.s_addr =
211		    myaddr.sin_addr.s_addr | ~ netmask.sin_addr.s_addr;
212		bcopy(&netmask, &nd3->myif.ifra_mask, sizeof(netmask));
213	} else {
214		bcopy(&myaddr, &nd->myif.ifra_addr, sizeof(myaddr));
215		bcopy(&myaddr, &nd->myif.ifra_broadaddr, sizeof(myaddr));
216		((struct sockaddr_in *)
217		   &nd->myif.ifra_broadaddr)->sin_addr.s_addr =
218		    myaddr.sin_addr.s_addr | ~ netmask.sin_addr.s_addr;
219		bcopy(&netmask, &nd->myif.ifra_mask, sizeof(netmask));
220	}
221
222	if (hwaddr_to_sockaddr("boot.netif.hwaddr", &ourdl)) {
223		printf("nfs_diskless: no hardware address\n");
224		return;
225	}
226	ifa = NULL;
227	timeout_at = time_uptime + NFS_IFACE_TIMEOUT_SECS;
228retry:
229	CURVNET_SET(TD_TO_VNET(curthread));
230	IFNET_RLOCK();
231	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
232		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
233			if (ifa->ifa_addr->sa_family == AF_LINK) {
234				sdl = (struct sockaddr_dl *)ifa->ifa_addr;
235				if ((sdl->sdl_type == ourdl.sdl_type) &&
236				    (sdl->sdl_alen == ourdl.sdl_alen) &&
237				    !bcmp(LLADDR(sdl),
238					  LLADDR(&ourdl),
239					  sdl->sdl_alen)) {
240				    IFNET_RUNLOCK();
241				    CURVNET_RESTORE();
242				    goto match_done;
243				}
244			}
245		}
246	}
247	IFNET_RUNLOCK();
248	CURVNET_RESTORE();
249	if (time_uptime < timeout_at) {
250		pause("nfssdl", hz / 5);
251		goto retry;
252	}
253	printf("nfs_diskless: no interface\n");
254	return;	/* no matching interface */
255match_done:
256	kern_setenv("boot.netif.name", ifp->if_xname);
257	if (is_nfsv3 != 0) {
258		strlcpy(nd3->myif.ifra_name, ifp->if_xname,
259		    sizeof(nd3->myif.ifra_name));
260
261		/* set up gateway */
262		inaddr_to_sockaddr("boot.netif.gateway", &nd3->mygateway);
263
264		/* set up root mount */
265		nd3->root_args.rsize = 32768;		/* XXX tunable? */
266		nd3->root_args.wsize = 32768;
267		nd3->root_args.sotype = SOCK_STREAM;
268		nd3->root_args.flags = (NFSMNT_NFSV3 | NFSMNT_WSIZE |
269		    NFSMNT_RSIZE | NFSMNT_RESVPORT);
270		if (inaddr_to_sockaddr("boot.nfsroot.server",
271		    &nd3->root_saddr)) {
272			printf("nfs_diskless: no server\n");
273			return;
274		}
275		nd3->root_saddr.sin_port = htons(NFS_PORT);
276		fhlen = decode_nfshandle("boot.nfsroot.nfshandle",
277		    &nd3->root_fh[0], NFSX_V3FHMAX);
278		if (fhlen == 0) {
279			printf("nfs_diskless: no NFS handle\n");
280			return;
281		}
282		if (fhlen != nd3->root_fhsize) {
283			printf("nfs_diskless: bad NFS handle len=%d\n", fhlen);
284			return;
285		}
286		if ((cp = kern_getenv("boot.nfsroot.path")) != NULL) {
287			strncpy(nd3->root_hostnam, cp, MNAMELEN - 1);
288			freeenv(cp);
289		}
290		if ((cp = kern_getenv("boot.nfsroot.options")) != NULL) {
291			nfs_parse_options(cp, &nd3->root_args);
292			freeenv(cp);
293		}
294
295		nfs_diskless_valid = 3;
296	} else {
297		strlcpy(nd->myif.ifra_name, ifp->if_xname,
298		    sizeof(nd->myif.ifra_name));
299
300		/* set up gateway */
301		inaddr_to_sockaddr("boot.netif.gateway", &nd->mygateway);
302
303		/* set up root mount */
304		nd->root_args.rsize = 8192;		/* XXX tunable? */
305		nd->root_args.wsize = 8192;
306		nd->root_args.sotype = SOCK_STREAM;
307		nd->root_args.flags = (NFSMNT_WSIZE |
308		    NFSMNT_RSIZE | NFSMNT_RESVPORT);
309		if (inaddr_to_sockaddr("boot.nfsroot.server",
310		    &nd->root_saddr)) {
311			printf("nfs_diskless: no server\n");
312			return;
313		}
314		nd->root_saddr.sin_port = htons(NFS_PORT);
315		if (decode_nfshandle("boot.nfsroot.nfshandle",
316		    &nd->root_fh[0], NFSX_V2FH) == 0) {
317			printf("nfs_diskless: no NFS handle\n");
318			return;
319		}
320		if ((cp = kern_getenv("boot.nfsroot.path")) != NULL) {
321			strncpy(nd->root_hostnam, cp, MNAMELEN - 1);
322			freeenv(cp);
323		}
324		if ((cp = kern_getenv("boot.nfsroot.options")) != NULL) {
325			struct nfs_args args;
326
327			/*
328			 * XXX yech, convert between old and current
329			 * arg format
330			 */
331			args.flags = nd->root_args.flags;
332			args.sotype = nd->root_args.sotype;
333			args.rsize = nd->root_args.rsize;
334			args.wsize = nd->root_args.wsize;
335			nfs_parse_options(cp, &args);
336			nd->root_args.flags = args.flags;
337			nd->root_args.sotype = args.sotype;
338			nd->root_args.rsize = args.rsize;
339			nd->root_args.wsize = args.wsize;
340			freeenv(cp);
341		}
342
343		nfs_diskless_valid = 1;
344	}
345}
346
347static int
348inaddr_to_sockaddr(char *ev, struct sockaddr_in *sa)
349{
350	u_int32_t a[4];
351	char *cp;
352	int count;
353
354	bzero(sa, sizeof(*sa));
355	sa->sin_len = sizeof(*sa);
356	sa->sin_family = AF_INET;
357
358	if ((cp = kern_getenv(ev)) == NULL)
359		return (1);
360	count = sscanf(cp, "%d.%d.%d.%d", &a[0], &a[1], &a[2], &a[3]);
361	freeenv(cp);
362	if (count != 4)
363		return (1);
364	sa->sin_addr.s_addr =
365	    htonl((a[0] << 24) | (a[1] << 16) | (a[2] << 8) | a[3]);
366	return (0);
367}
368
369static int
370hwaddr_to_sockaddr(char *ev, struct sockaddr_dl *sa)
371{
372	char *cp;
373	u_int32_t a[6];
374	int count;
375
376	bzero(sa, sizeof(*sa));
377	sa->sdl_len = sizeof(*sa);
378	sa->sdl_family = AF_LINK;
379	sa->sdl_type = IFT_ETHER;
380	sa->sdl_alen = ETHER_ADDR_LEN;
381	if ((cp = kern_getenv(ev)) == NULL)
382		return (1);
383	count = sscanf(cp, "%x:%x:%x:%x:%x:%x",
384	    &a[0], &a[1], &a[2], &a[3], &a[4], &a[5]);
385	freeenv(cp);
386	if (count != 6)
387		return (1);
388	sa->sdl_data[0] = a[0];
389	sa->sdl_data[1] = a[1];
390	sa->sdl_data[2] = a[2];
391	sa->sdl_data[3] = a[3];
392	sa->sdl_data[4] = a[4];
393	sa->sdl_data[5] = a[5];
394	return (0);
395}
396
397static int
398decode_nfshandle(char *ev, u_char *fh, int maxfh)
399{
400	u_char *cp, *ep;
401	int len, val;
402
403	ep = cp = kern_getenv(ev);
404	if (cp == NULL)
405		return (0);
406	if ((strlen(cp) < 2) || (*cp != 'X')) {
407		freeenv(ep);
408		return (0);
409	}
410	len = 0;
411	cp++;
412	for (;;) {
413		if (*cp == 'X') {
414			freeenv(ep);
415			return (len);
416		}
417		if ((sscanf(cp, "%2x", &val) != 1) || (val > 0xff)) {
418			freeenv(ep);
419			return (0);
420		}
421		*(fh++) = val;
422		len++;
423		cp += 2;
424		if (len > maxfh) {
425		    freeenv(ep);
426		    return (0);
427		}
428	}
429}
430
431#if !defined(NEW_NFS_BOOT_BOOTP)
432static void
433nfs_rootconf(void)
434{
435
436	nfs_setup_diskless();
437	if (nfs_diskless_valid)
438		rootdevnames[0] = "nfs:";
439}
440
441SYSINIT(cpu_rootconf, SI_SUB_ROOT_CONF, SI_ORDER_FIRST, nfs_rootconf, NULL);
442#endif
443
444