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nfs_diskless.c revision 1.1.1.2
      1 /*	$NetBSD: nfs_diskless.c,v 1.1.1.2 2016/11/18 07:49:12 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 1.1.1.2 2016/11/18 07:49:12 pgoyette Exp $");
     39 
     40 #include "opt_bootp.h"
     41 
     42 #include <sys/param.h>
     43 #include <sys/systm.h>
     44 #include <sys/jail.h>
     45 #include <sys/kernel.h>
     46 #include <sys/malloc.h>
     47 #include <sys/mount.h>
     48 #include <sys/socket.h>
     49 
     50 #include <net/if.h>
     51 #include <net/if_dl.h>
     52 #include <net/if_types.h>
     53 #include <net/if_var.h>
     54 #include <net/ethernet.h>
     55 #include <net/vnet.h>
     56 
     57 #include <netinet/in.h>
     58 #include <nfs/nfsproto.h>
     59 #include <nfsclient/nfs.h>
     60 #include <nfs/nfsdiskless.h>
     61 
     62 #define	NFS_IFACE_TIMEOUT_SECS	10 /* Timeout for interface to appear. */
     63 
     64 static int inaddr_to_sockaddr(char *ev, struct sockaddr_in *sa);
     65 static int hwaddr_to_sockaddr(char *ev, struct sockaddr_dl *sa);
     66 static int decode_nfshandle(char *ev, u_char *fh, int maxfh);
     67 
     68 /*
     69  * This structure must be filled in by a primary bootstrap or bootstrap
     70  * server for a diskless/dataless machine. It is initialized below just
     71  * to ensure that it is allocated to initialized data (.data not .bss).
     72  */
     73 struct nfs_diskless	nfs_diskless = { { { 0 } } };
     74 struct nfsv3_diskless	nfsv3_diskless = { { { 0 } } };
     75 int			nfs_diskless_valid = 0;
     76 
     77 /*
     78  * Validate/sanity check a rsize/wsize parameter.
     79  */
     80 static int
     81 checkrwsize(unsigned long v, const char *name)
     82 {
     83 	/*
     84 	 * 32K is used as an upper bound because most servers
     85 	 * limit block size to satisfy IPv4's limit of
     86 	 * 64K/reassembled packet.  The lower bound is pretty
     87 	 * much arbitrary.
     88 	 */
     89 	if (!(4 <= v && v <= 32*1024)) {
     90 		printf("nfs_parse_options: invalid %s %lu ignored\n", name, v);
     91 		return 0;
     92 	} else
     93 		return 1;
     94 }
     95 
     96 /*
     97  * Parse mount options and apply them to the supplied
     98  * nfs_diskless state.  Used also by bootp/dhcp support.
     99  */
    100 void
    101 nfs_parse_options(const char *envopts, struct nfs_args *nd)
    102 {
    103 	char *opts, *o, *otmp;
    104 	unsigned long v;
    105 
    106 	opts = strdup(envopts, M_TEMP);
    107 	otmp = opts;
    108 	while ((o = strsep(&otmp, ":;, ")) != NULL) {
    109 		if (*o == '\0')
    110 			; /* Skip empty options. */
    111 		else if (strcmp(o, "soft") == 0)
    112 			nd->flags |= NFSMNT_SOFT;
    113 		else if (strcmp(o, "intr") == 0)
    114 			nd->flags |= NFSMNT_INT;
    115 		else if (strcmp(o, "conn") == 0)
    116 			nd->flags |= NFSMNT_NOCONN;
    117 		else if (strcmp(o, "nolockd") == 0)
    118 			nd->flags |= NFSMNT_NOLOCKD;
    119 		else if (strcmp(o, "nocto") == 0)
    120 			nd->flags |= NFSMNT_NOCTO;
    121 		else if (strcmp(o, "nfsv2") == 0)
    122 			nd->flags &= ~(NFSMNT_NFSV3 | NFSMNT_NFSV4);
    123 		else if (strcmp(o, "nfsv3") == 0) {
    124 			nd->flags &= ~NFSMNT_NFSV4;
    125 			nd->flags |= NFSMNT_NFSV3;
    126 		} else if (strcmp(o, "tcp") == 0)
    127 			nd->sotype = SOCK_STREAM;
    128 		else if (strcmp(o, "udp") == 0)
    129 			nd->sotype = SOCK_DGRAM;
    130 		else if (strncmp(o, "rsize=", 6) == 0) {
    131 			v = strtoul(o+6, NULL, 10);
    132 			if (checkrwsize(v, "rsize")) {
    133 				nd->rsize = (int) v;
    134 				nd->flags |= NFSMNT_RSIZE;
    135 			}
    136 		} else if (strncmp(o, "wsize=", 6) == 0) {
    137 			v = strtoul(o+6, NULL, 10);
    138 			if (checkrwsize(v, "wsize")) {
    139 				nd->wsize = (int) v;
    140 				nd->flags |= NFSMNT_WSIZE;
    141 			}
    142 		} else
    143 			printf("%s: skipping unknown option \"%s\"\n",
    144 			    __func__, o);
    145 	}
    146 	free(opts, M_TEMP);
    147 }
    148 
    149 /*
    150  * Populate the essential fields in the nfsv3_diskless structure.
    151  *
    152  * The loader is expected to export the following environment variables:
    153  *
    154  * boot.netif.name		name of boot interface
    155  * boot.netif.ip		IP address on boot interface
    156  * boot.netif.netmask		netmask on boot interface
    157  * boot.netif.gateway		default gateway (optional)
    158  * boot.netif.hwaddr		hardware address of boot interface
    159  * boot.netif.mtu		interface mtu from bootp/dhcp (optional)
    160  * boot.nfsroot.server		IP address of root filesystem server
    161  * boot.nfsroot.path		path of the root filesystem on server
    162  * boot.nfsroot.nfshandle	NFS handle for root filesystem on server
    163  * boot.nfsroot.nfshandlelen	and length of this handle (for NFSv3 only)
    164  * boot.nfsroot.options		NFS options for the root filesystem
    165  */
    166 void
    167 nfs_setup_diskless(void)
    168 {
    169 	struct nfs_diskless *nd = &nfs_diskless;
    170 	struct nfsv3_diskless *nd3 = &nfsv3_diskless;
    171 	struct ifnet *ifp;
    172 	struct ifaddr *ifa;
    173 	struct sockaddr_dl *sdl, ourdl;
    174 	struct sockaddr_in myaddr, netmask;
    175 	char *cp;
    176 	int cnt, fhlen, is_nfsv3;
    177 	uint32_t len;
    178 	time_t timeout_at;
    179 
    180 	if (nfs_diskless_valid != 0)
    181 		return;
    182 
    183 	/* get handle size. If this succeeds, it's an NFSv3 setup. */
    184 	if ((cp = kern_getenv("boot.nfsroot.nfshandlelen")) != NULL) {
    185 		cnt = sscanf(cp, "%d", &len);
    186 		freeenv(cp);
    187 		if (cnt != 1 || len == 0 || len > NFSX_V3FHMAX) {
    188 			printf("nfs_diskless: bad NFS handle len\n");
    189 			return;
    190 		}
    191 		nd3->root_fhsize = len;
    192 		is_nfsv3 = 1;
    193 	} else
    194 		is_nfsv3 = 0;
    195 	/* set up interface */
    196 	if (inaddr_to_sockaddr("boot.netif.ip", &myaddr))
    197 		return;
    198 	if (inaddr_to_sockaddr("boot.netif.netmask", &netmask)) {
    199 		printf("nfs_diskless: no netmask\n");
    200 		return;
    201 	}
    202 	if (is_nfsv3 != 0) {
    203 		bcopy(&myaddr, &nd3->myif.ifra_addr, sizeof(myaddr));
    204 		bcopy(&myaddr, &nd3->myif.ifra_broadaddr, sizeof(myaddr));
    205 		((struct sockaddr_in *)
    206 		   &nd3->myif.ifra_broadaddr)->sin_addr.s_addr =
    207 		    myaddr.sin_addr.s_addr | ~ netmask.sin_addr.s_addr;
    208 		bcopy(&netmask, &nd3->myif.ifra_mask, sizeof(netmask));
    209 	} else {
    210 		bcopy(&myaddr, &nd->myif.ifra_addr, sizeof(myaddr));
    211 		bcopy(&myaddr, &nd->myif.ifra_broadaddr, sizeof(myaddr));
    212 		((struct sockaddr_in *)
    213 		   &nd->myif.ifra_broadaddr)->sin_addr.s_addr =
    214 		    myaddr.sin_addr.s_addr | ~ netmask.sin_addr.s_addr;
    215 		bcopy(&netmask, &nd->myif.ifra_mask, sizeof(netmask));
    216 	}
    217 
    218 	if (hwaddr_to_sockaddr("boot.netif.hwaddr", &ourdl)) {
    219 		printf("nfs_diskless: no hardware address\n");
    220 		return;
    221 	}
    222 	ifa = NULL;
    223 	timeout_at = time_uptime + NFS_IFACE_TIMEOUT_SECS;
    224 retry:
    225 	CURVNET_SET(TD_TO_VNET(curthread));
    226 	IFNET_RLOCK();
    227 	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
    228 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
    229 			if (ifa->ifa_addr->sa_family == AF_LINK) {
    230 				sdl = (struct sockaddr_dl *)ifa->ifa_addr;
    231 				if ((sdl->sdl_type == ourdl.sdl_type) &&
    232 				    (sdl->sdl_alen == ourdl.sdl_alen) &&
    233 				    !bcmp(LLADDR(sdl),
    234 					  LLADDR(&ourdl),
    235 					  sdl->sdl_alen)) {
    236 				    IFNET_RUNLOCK();
    237 				    CURVNET_RESTORE();
    238 				    goto match_done;
    239 				}
    240 			}
    241 		}
    242 	}
    243 	IFNET_RUNLOCK();
    244 	CURVNET_RESTORE();
    245 	if (time_uptime < timeout_at) {
    246 		pause("nfssdl", hz / 5);
    247 		goto retry;
    248 	}
    249 	printf("nfs_diskless: no interface\n");
    250 	return;	/* no matching interface */
    251 match_done:
    252 	kern_setenv("boot.netif.name", ifp->if_xname);
    253 	if (is_nfsv3 != 0) {
    254 		strlcpy(nd3->myif.ifra_name, ifp->if_xname,
    255 		    sizeof(nd3->myif.ifra_name));
    256 
    257 		/* set up gateway */
    258 		inaddr_to_sockaddr("boot.netif.gateway", &nd3->mygateway);
    259 
    260 		/* set up root mount */
    261 		nd3->root_args.rsize = 32768;		/* XXX tunable? */
    262 		nd3->root_args.wsize = 32768;
    263 		nd3->root_args.sotype = SOCK_STREAM;
    264 		nd3->root_args.flags = (NFSMNT_NFSV3 | NFSMNT_WSIZE |
    265 		    NFSMNT_RSIZE | NFSMNT_RESVPORT);
    266 		if (inaddr_to_sockaddr("boot.nfsroot.server",
    267 		    &nd3->root_saddr)) {
    268 			printf("nfs_diskless: no server\n");
    269 			return;
    270 		}
    271 		nd3->root_saddr.sin_port = htons(NFS_PORT);
    272 		fhlen = decode_nfshandle("boot.nfsroot.nfshandle",
    273 		    &nd3->root_fh[0], NFSX_V3FHMAX);
    274 		if (fhlen == 0) {
    275 			printf("nfs_diskless: no NFS handle\n");
    276 			return;
    277 		}
    278 		if (fhlen != nd3->root_fhsize) {
    279 			printf("nfs_diskless: bad NFS handle len=%d\n", fhlen);
    280 			return;
    281 		}
    282 		if ((cp = kern_getenv("boot.nfsroot.path")) != NULL) {
    283 			strncpy(nd3->root_hostnam, cp, MNAMELEN - 1);
    284 			freeenv(cp);
    285 		}
    286 		if ((cp = kern_getenv("boot.nfsroot.options")) != NULL) {
    287 			nfs_parse_options(cp, &nd3->root_args);
    288 			freeenv(cp);
    289 		}
    290 
    291 		nfs_diskless_valid = 3;
    292 	} else {
    293 		strlcpy(nd->myif.ifra_name, ifp->if_xname,
    294 		    sizeof(nd->myif.ifra_name));
    295 
    296 		/* set up gateway */
    297 		inaddr_to_sockaddr("boot.netif.gateway", &nd->mygateway);
    298 
    299 		/* set up root mount */
    300 		nd->root_args.rsize = 8192;		/* XXX tunable? */
    301 		nd->root_args.wsize = 8192;
    302 		nd->root_args.sotype = SOCK_STREAM;
    303 		nd->root_args.flags = (NFSMNT_WSIZE |
    304 		    NFSMNT_RSIZE | NFSMNT_RESVPORT);
    305 		if (inaddr_to_sockaddr("boot.nfsroot.server",
    306 		    &nd->root_saddr)) {
    307 			printf("nfs_diskless: no server\n");
    308 			return;
    309 		}
    310 		nd->root_saddr.sin_port = htons(NFS_PORT);
    311 		if (decode_nfshandle("boot.nfsroot.nfshandle",
    312 		    &nd->root_fh[0], NFSX_V2FH) == 0) {
    313 			printf("nfs_diskless: no NFS handle\n");
    314 			return;
    315 		}
    316 		if ((cp = kern_getenv("boot.nfsroot.path")) != NULL) {
    317 			strncpy(nd->root_hostnam, cp, MNAMELEN - 1);
    318 			freeenv(cp);
    319 		}
    320 		if ((cp = kern_getenv("boot.nfsroot.options")) != NULL) {
    321 			struct nfs_args args;
    322 
    323 			/*
    324 			 * XXX yech, convert between old and current
    325 			 * arg format
    326 			 */
    327 			args.flags = nd->root_args.flags;
    328 			args.sotype = nd->root_args.sotype;
    329 			args.rsize = nd->root_args.rsize;
    330 			args.wsize = nd->root_args.wsize;
    331 			nfs_parse_options(cp, &args);
    332 			nd->root_args.flags = args.flags;
    333 			nd->root_args.sotype = args.sotype;
    334 			nd->root_args.rsize = args.rsize;
    335 			nd->root_args.wsize = args.wsize;
    336 			freeenv(cp);
    337 		}
    338 
    339 		nfs_diskless_valid = 1;
    340 	}
    341 }
    342 
    343 static int
    344 inaddr_to_sockaddr(char *ev, struct sockaddr_in *sa)
    345 {
    346 	u_int32_t a[4];
    347 	char *cp;
    348 	int count;
    349 
    350 	bzero(sa, sizeof(*sa));
    351 	sa->sin_len = sizeof(*sa);
    352 	sa->sin_family = AF_INET;
    353 
    354 	if ((cp = kern_getenv(ev)) == NULL)
    355 		return (1);
    356 	count = sscanf(cp, "%d.%d.%d.%d", &a[0], &a[1], &a[2], &a[3]);
    357 	freeenv(cp);
    358 	if (count != 4)
    359 		return (1);
    360 	sa->sin_addr.s_addr =
    361 	    htonl((a[0] << 24) | (a[1] << 16) | (a[2] << 8) | a[3]);
    362 	return (0);
    363 }
    364 
    365 static int
    366 hwaddr_to_sockaddr(char *ev, struct sockaddr_dl *sa)
    367 {
    368 	char *cp;
    369 	u_int32_t a[6];
    370 	int count;
    371 
    372 	bzero(sa, sizeof(*sa));
    373 	sa->sdl_len = sizeof(*sa);
    374 	sa->sdl_family = AF_LINK;
    375 	sa->sdl_type = IFT_ETHER;
    376 	sa->sdl_alen = ETHER_ADDR_LEN;
    377 	if ((cp = kern_getenv(ev)) == NULL)
    378 		return (1);
    379 	count = sscanf(cp, "%x:%x:%x:%x:%x:%x",
    380 	    &a[0], &a[1], &a[2], &a[3], &a[4], &a[5]);
    381 	freeenv(cp);
    382 	if (count != 6)
    383 		return (1);
    384 	sa->sdl_data[0] = a[0];
    385 	sa->sdl_data[1] = a[1];
    386 	sa->sdl_data[2] = a[2];
    387 	sa->sdl_data[3] = a[3];
    388 	sa->sdl_data[4] = a[4];
    389 	sa->sdl_data[5] = a[5];
    390 	return (0);
    391 }
    392 
    393 static int
    394 decode_nfshandle(char *ev, u_char *fh, int maxfh)
    395 {
    396 	u_char *cp, *ep;
    397 	int len, val;
    398 
    399 	ep = cp = kern_getenv(ev);
    400 	if (cp == NULL)
    401 		return (0);
    402 	if ((strlen(cp) < 2) || (*cp != 'X')) {
    403 		freeenv(ep);
    404 		return (0);
    405 	}
    406 	len = 0;
    407 	cp++;
    408 	for (;;) {
    409 		if (*cp == 'X') {
    410 			freeenv(ep);
    411 			return (len);
    412 		}
    413 		if ((sscanf(cp, "%2x", &val) != 1) || (val > 0xff)) {
    414 			freeenv(ep);
    415 			return (0);
    416 		}
    417 		*(fh++) = val;
    418 		len++;
    419 		cp += 2;
    420 		if (len > maxfh) {
    421 		    freeenv(ep);
    422 		    return (0);
    423 		}
    424 	}
    425 }
    426 
    427 #if !defined(BOOTP_NFSROOT)
    428 static void
    429 nfs_rootconf(void)
    430 {
    431 
    432 	nfs_setup_diskless();
    433 	if (nfs_diskless_valid)
    434 		rootdevnames[0] = "nfs:";
    435 }
    436 
    437 SYSINIT(cpu_rootconf, SI_SUB_ROOT_CONF, SI_ORDER_FIRST, nfs_rootconf, NULL);
    438 #endif
    439 
    440