xref: /openbmc/u-boot/net/nfs.c (revision 8729d582)
1 /*
2  * NFS support driver - based on etherboot and U-BOOT's tftp.c
3  *
4  * Masami Komiya <mkomiya@sonare.it> 2004
5  *
6  */
7 
8 /* NOTE: the NFS code is heavily inspired by the NetBSD netboot code (read:
9  * large portions are copied verbatim) as distributed in OSKit 0.97.  A few
10  * changes were necessary to adapt the code to Etherboot and to fix several
11  * inconsistencies.  Also the RPC message preparation is done "by hand" to
12  * avoid adding netsprintf() which I find hard to understand and use.  */
13 
14 /* NOTE 2: Etherboot does not care about things beyond the kernel image, so
15  * it loads the kernel image off the boot server (ARP_SERVER) and does not
16  * access the client root disk (root-path in dhcpd.conf), which would use
17  * ARP_ROOTSERVER.  The root disk is something the operating system we are
18  * about to load needs to use.	This is different from the OSKit 0.97 logic.  */
19 
20 /* NOTE 3: Symlink handling introduced by Anselm M Hoffmeister, 2003-July-14
21  * If a symlink is encountered, it is followed as far as possible (recursion
22  * possible, maximum 16 steps). There is no clearing of ".."'s inside the
23  * path, so please DON'T DO THAT. thx. */
24 
25 #include <common.h>
26 #include <command.h>
27 #include <net.h>
28 #include <malloc.h>
29 #include <mapmem.h>
30 #include "nfs.h"
31 #include "bootp.h"
32 
33 #define HASHES_PER_LINE 65	/* Number of "loading" hashes per line	*/
34 #define NFS_RETRY_COUNT 30
35 #ifndef CONFIG_NFS_TIMEOUT
36 # define NFS_TIMEOUT 2000UL
37 #else
38 # define NFS_TIMEOUT CONFIG_NFS_TIMEOUT
39 #endif
40 
41 #define NFS_RPC_ERR	1
42 #define NFS_RPC_DROP	124
43 
44 static int fs_mounted;
45 static unsigned long rpc_id;
46 static int nfs_offset = -1;
47 static int nfs_len;
48 static ulong nfs_timeout = NFS_TIMEOUT;
49 
50 static char dirfh[NFS_FHSIZE];	/* file handle of directory */
51 static char filefh[NFS_FHSIZE]; /* file handle of kernel image */
52 
53 static enum net_loop_state nfs_download_state;
54 static struct in_addr nfs_server_ip;
55 static int nfs_server_mount_port;
56 static int nfs_server_port;
57 static int nfs_our_port;
58 static int nfs_timeout_count;
59 static int nfs_state;
60 #define STATE_PRCLOOKUP_PROG_MOUNT_REQ	1
61 #define STATE_PRCLOOKUP_PROG_NFS_REQ	2
62 #define STATE_MOUNT_REQ			3
63 #define STATE_UMOUNT_REQ		4
64 #define STATE_LOOKUP_REQ		5
65 #define STATE_READ_REQ			6
66 #define STATE_READLINK_REQ		7
67 
68 static char default_filename[64];
69 static char *nfs_filename;
70 static char *nfs_path;
71 static char nfs_path_buff[2048];
72 
73 static inline int store_block(uchar *src, unsigned offset, unsigned len)
74 {
75 	ulong newsize = offset + len;
76 #ifdef CONFIG_SYS_DIRECT_FLASH_NFS
77 	int i, rc = 0;
78 
79 	for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; i++) {
80 		/* start address in flash? */
81 		if (load_addr + offset >= flash_info[i].start[0]) {
82 			rc = 1;
83 			break;
84 		}
85 	}
86 
87 	if (rc) { /* Flash is destination for this packet */
88 		rc = flash_write((uchar *)src, (ulong)(load_addr+offset), len);
89 		if (rc) {
90 			flash_perror(rc);
91 			return -1;
92 		}
93 	} else
94 #endif /* CONFIG_SYS_DIRECT_FLASH_NFS */
95 	{
96 		void *ptr = map_sysmem(load_addr + offset, len);
97 
98 		memcpy(ptr, src, len);
99 		unmap_sysmem(ptr);
100 	}
101 
102 	if (net_boot_file_size < (offset + len))
103 		net_boot_file_size = newsize;
104 	return 0;
105 }
106 
107 static char *basename(char *path)
108 {
109 	char *fname;
110 
111 	fname = path + strlen(path) - 1;
112 	while (fname >= path) {
113 		if (*fname == '/') {
114 			fname++;
115 			break;
116 		}
117 		fname--;
118 	}
119 	return fname;
120 }
121 
122 static char *dirname(char *path)
123 {
124 	char *fname;
125 
126 	fname = basename(path);
127 	--fname;
128 	*fname = '\0';
129 	return path;
130 }
131 
132 /**************************************************************************
133 RPC_ADD_CREDENTIALS - Add RPC authentication/verifier entries
134 **************************************************************************/
135 static uint32_t *rpc_add_credentials(uint32_t *p)
136 {
137 	int hl;
138 	int hostnamelen;
139 	char hostname[256];
140 
141 	strcpy(hostname, "");
142 	hostnamelen = strlen(hostname);
143 
144 	/* Here's the executive summary on authentication requirements of the
145 	 * various NFS server implementations:	Linux accepts both AUTH_NONE
146 	 * and AUTH_UNIX authentication (also accepts an empty hostname field
147 	 * in the AUTH_UNIX scheme).  *BSD refuses AUTH_NONE, but accepts
148 	 * AUTH_UNIX (also accepts an empty hostname field in the AUTH_UNIX
149 	 * scheme).  To be safe, use AUTH_UNIX and pass the hostname if we have
150 	 * it (if the BOOTP/DHCP reply didn't give one, just use an empty
151 	 * hostname).  */
152 
153 	hl = (hostnamelen + 3) & ~3;
154 
155 	/* Provide an AUTH_UNIX credential.  */
156 	*p++ = htonl(1);		/* AUTH_UNIX */
157 	*p++ = htonl(hl+20);		/* auth length */
158 	*p++ = htonl(0);		/* stamp */
159 	*p++ = htonl(hostnamelen);	/* hostname string */
160 	if (hostnamelen & 3)
161 		*(p + hostnamelen / 4) = 0; /* add zero padding */
162 	memcpy(p, hostname, hostnamelen);
163 	p += hl / 4;
164 	*p++ = 0;			/* uid */
165 	*p++ = 0;			/* gid */
166 	*p++ = 0;			/* auxiliary gid list */
167 
168 	/* Provide an AUTH_NONE verifier.  */
169 	*p++ = 0;			/* AUTH_NONE */
170 	*p++ = 0;			/* auth length */
171 
172 	return p;
173 }
174 
175 /**************************************************************************
176 RPC_LOOKUP - Lookup RPC Port numbers
177 **************************************************************************/
178 static void rpc_req(int rpc_prog, int rpc_proc, uint32_t *data, int datalen)
179 {
180 	struct rpc_t pkt;
181 	unsigned long id;
182 	uint32_t *p;
183 	int pktlen;
184 	int sport;
185 
186 	id = ++rpc_id;
187 	pkt.u.call.id = htonl(id);
188 	pkt.u.call.type = htonl(MSG_CALL);
189 	pkt.u.call.rpcvers = htonl(2);	/* use RPC version 2 */
190 	pkt.u.call.prog = htonl(rpc_prog);
191 	pkt.u.call.vers = htonl(2);	/* portmapper is version 2 */
192 	pkt.u.call.proc = htonl(rpc_proc);
193 	p = (uint32_t *)&(pkt.u.call.data);
194 
195 	if (datalen)
196 		memcpy((char *)p, (char *)data, datalen*sizeof(uint32_t));
197 
198 	pktlen = (char *)p + datalen*sizeof(uint32_t) - (char *)&pkt;
199 
200 	memcpy((char *)net_tx_packet + net_eth_hdr_size() + IP_UDP_HDR_SIZE,
201 	       (char *)&pkt, pktlen);
202 
203 	if (rpc_prog == PROG_PORTMAP)
204 		sport = SUNRPC_PORT;
205 	else if (rpc_prog == PROG_MOUNT)
206 		sport = nfs_server_mount_port;
207 	else
208 		sport = nfs_server_port;
209 
210 	net_send_udp_packet(net_server_ethaddr, nfs_server_ip, sport,
211 			    nfs_our_port, pktlen);
212 }
213 
214 /**************************************************************************
215 RPC_LOOKUP - Lookup RPC Port numbers
216 **************************************************************************/
217 static void rpc_lookup_req(int prog, int ver)
218 {
219 	uint32_t data[16];
220 
221 	data[0] = 0; data[1] = 0;	/* auth credential */
222 	data[2] = 0; data[3] = 0;	/* auth verifier */
223 	data[4] = htonl(prog);
224 	data[5] = htonl(ver);
225 	data[6] = htonl(17);	/* IP_UDP */
226 	data[7] = 0;
227 
228 	rpc_req(PROG_PORTMAP, PORTMAP_GETPORT, data, 8);
229 }
230 
231 /**************************************************************************
232 NFS_MOUNT - Mount an NFS Filesystem
233 **************************************************************************/
234 static void nfs_mount_req(char *path)
235 {
236 	uint32_t data[1024];
237 	uint32_t *p;
238 	int len;
239 	int pathlen;
240 
241 	pathlen = strlen(path);
242 
243 	p = &(data[0]);
244 	p = rpc_add_credentials(p);
245 
246 	*p++ = htonl(pathlen);
247 	if (pathlen & 3)
248 		*(p + pathlen / 4) = 0;
249 	memcpy(p, path, pathlen);
250 	p += (pathlen + 3) / 4;
251 
252 	len = (uint32_t *)p - (uint32_t *)&(data[0]);
253 
254 	rpc_req(PROG_MOUNT, MOUNT_ADDENTRY, data, len);
255 }
256 
257 /**************************************************************************
258 NFS_UMOUNTALL - Unmount all our NFS Filesystems on the Server
259 **************************************************************************/
260 static void nfs_umountall_req(void)
261 {
262 	uint32_t data[1024];
263 	uint32_t *p;
264 	int len;
265 
266 	if ((nfs_server_mount_port == -1) || (!fs_mounted))
267 		/* Nothing mounted, nothing to umount */
268 		return;
269 
270 	p = &(data[0]);
271 	p = rpc_add_credentials(p);
272 
273 	len = (uint32_t *)p - (uint32_t *)&(data[0]);
274 
275 	rpc_req(PROG_MOUNT, MOUNT_UMOUNTALL, data, len);
276 }
277 
278 /***************************************************************************
279  * NFS_READLINK (AH 2003-07-14)
280  * This procedure is called when read of the first block fails -
281  * this probably happens when it's a directory or a symlink
282  * In case of successful readlink(), the dirname is manipulated,
283  * so that inside the nfs() function a recursion can be done.
284  **************************************************************************/
285 static void nfs_readlink_req(void)
286 {
287 	uint32_t data[1024];
288 	uint32_t *p;
289 	int len;
290 
291 	p = &(data[0]);
292 	p = rpc_add_credentials(p);
293 
294 	memcpy(p, filefh, NFS_FHSIZE);
295 	p += (NFS_FHSIZE / 4);
296 
297 	len = (uint32_t *)p - (uint32_t *)&(data[0]);
298 
299 	rpc_req(PROG_NFS, NFS_READLINK, data, len);
300 }
301 
302 /**************************************************************************
303 NFS_LOOKUP - Lookup Pathname
304 **************************************************************************/
305 static void nfs_lookup_req(char *fname)
306 {
307 	uint32_t data[1024];
308 	uint32_t *p;
309 	int len;
310 	int fnamelen;
311 
312 	fnamelen = strlen(fname);
313 
314 	p = &(data[0]);
315 	p = rpc_add_credentials(p);
316 
317 	memcpy(p, dirfh, NFS_FHSIZE);
318 	p += (NFS_FHSIZE / 4);
319 	*p++ = htonl(fnamelen);
320 	if (fnamelen & 3)
321 		*(p + fnamelen / 4) = 0;
322 	memcpy(p, fname, fnamelen);
323 	p += (fnamelen + 3) / 4;
324 
325 	len = (uint32_t *)p - (uint32_t *)&(data[0]);
326 
327 	rpc_req(PROG_NFS, NFS_LOOKUP, data, len);
328 }
329 
330 /**************************************************************************
331 NFS_READ - Read File on NFS Server
332 **************************************************************************/
333 static void nfs_read_req(int offset, int readlen)
334 {
335 	uint32_t data[1024];
336 	uint32_t *p;
337 	int len;
338 
339 	p = &(data[0]);
340 	p = rpc_add_credentials(p);
341 
342 	memcpy(p, filefh, NFS_FHSIZE);
343 	p += (NFS_FHSIZE / 4);
344 	*p++ = htonl(offset);
345 	*p++ = htonl(readlen);
346 	*p++ = 0;
347 
348 	len = (uint32_t *)p - (uint32_t *)&(data[0]);
349 
350 	rpc_req(PROG_NFS, NFS_READ, data, len);
351 }
352 
353 /**************************************************************************
354 RPC request dispatcher
355 **************************************************************************/
356 static void nfs_send(void)
357 {
358 	debug("%s\n", __func__);
359 
360 	switch (nfs_state) {
361 	case STATE_PRCLOOKUP_PROG_MOUNT_REQ:
362 		rpc_lookup_req(PROG_MOUNT, 1);
363 		break;
364 	case STATE_PRCLOOKUP_PROG_NFS_REQ:
365 		rpc_lookup_req(PROG_NFS, 2);
366 		break;
367 	case STATE_MOUNT_REQ:
368 		nfs_mount_req(nfs_path);
369 		break;
370 	case STATE_UMOUNT_REQ:
371 		nfs_umountall_req();
372 		break;
373 	case STATE_LOOKUP_REQ:
374 		nfs_lookup_req(nfs_filename);
375 		break;
376 	case STATE_READ_REQ:
377 		nfs_read_req(nfs_offset, nfs_len);
378 		break;
379 	case STATE_READLINK_REQ:
380 		nfs_readlink_req();
381 		break;
382 	}
383 }
384 
385 /**************************************************************************
386 Handlers for the reply from server
387 **************************************************************************/
388 
389 static int rpc_lookup_reply(int prog, uchar *pkt, unsigned len)
390 {
391 	struct rpc_t rpc_pkt;
392 
393 	memcpy((unsigned char *)&rpc_pkt, pkt, len);
394 
395 	debug("%s\n", __func__);
396 
397 	if (ntohl(rpc_pkt.u.reply.id) > rpc_id)
398 		return -NFS_RPC_ERR;
399 	else if (ntohl(rpc_pkt.u.reply.id) < rpc_id)
400 		return -NFS_RPC_DROP;
401 
402 	if (rpc_pkt.u.reply.rstatus  ||
403 	    rpc_pkt.u.reply.verifier ||
404 	    rpc_pkt.u.reply.astatus)
405 		return -1;
406 
407 	switch (prog) {
408 	case PROG_MOUNT:
409 		nfs_server_mount_port = ntohl(rpc_pkt.u.reply.data[0]);
410 		break;
411 	case PROG_NFS:
412 		nfs_server_port = ntohl(rpc_pkt.u.reply.data[0]);
413 		break;
414 	}
415 
416 	return 0;
417 }
418 
419 static int nfs_mount_reply(uchar *pkt, unsigned len)
420 {
421 	struct rpc_t rpc_pkt;
422 
423 	debug("%s\n", __func__);
424 
425 	memcpy((unsigned char *)&rpc_pkt, pkt, len);
426 
427 	if (ntohl(rpc_pkt.u.reply.id) > rpc_id)
428 		return -NFS_RPC_ERR;
429 	else if (ntohl(rpc_pkt.u.reply.id) < rpc_id)
430 		return -NFS_RPC_DROP;
431 
432 	if (rpc_pkt.u.reply.rstatus  ||
433 	    rpc_pkt.u.reply.verifier ||
434 	    rpc_pkt.u.reply.astatus  ||
435 	    rpc_pkt.u.reply.data[0])
436 		return -1;
437 
438 	fs_mounted = 1;
439 	memcpy(dirfh, rpc_pkt.u.reply.data + 1, NFS_FHSIZE);
440 
441 	return 0;
442 }
443 
444 static int nfs_umountall_reply(uchar *pkt, unsigned len)
445 {
446 	struct rpc_t rpc_pkt;
447 
448 	debug("%s\n", __func__);
449 
450 	memcpy((unsigned char *)&rpc_pkt, pkt, len);
451 
452 	if (ntohl(rpc_pkt.u.reply.id) > rpc_id)
453 		return -NFS_RPC_ERR;
454 	else if (ntohl(rpc_pkt.u.reply.id) < rpc_id)
455 		return -NFS_RPC_DROP;
456 
457 	if (rpc_pkt.u.reply.rstatus  ||
458 	    rpc_pkt.u.reply.verifier ||
459 	    rpc_pkt.u.reply.astatus)
460 		return -1;
461 
462 	fs_mounted = 0;
463 	memset(dirfh, 0, sizeof(dirfh));
464 
465 	return 0;
466 }
467 
468 static int nfs_lookup_reply(uchar *pkt, unsigned len)
469 {
470 	struct rpc_t rpc_pkt;
471 
472 	debug("%s\n", __func__);
473 
474 	memcpy((unsigned char *)&rpc_pkt, pkt, len);
475 
476 	if (ntohl(rpc_pkt.u.reply.id) > rpc_id)
477 		return -NFS_RPC_ERR;
478 	else if (ntohl(rpc_pkt.u.reply.id) < rpc_id)
479 		return -NFS_RPC_DROP;
480 
481 	if (rpc_pkt.u.reply.rstatus  ||
482 	    rpc_pkt.u.reply.verifier ||
483 	    rpc_pkt.u.reply.astatus  ||
484 	    rpc_pkt.u.reply.data[0]) {
485 		switch (ntohl(rpc_pkt.u.reply.astatus)) {
486 		case 0: /* Not an error */
487 			break;
488 		case 2: /* Remote can't support NFS version */
489 			printf("*** ERROR: NFS version not supported: Requested: V%d, accepted: min V%d - max V%d\n",
490 			       2,
491 			       ntohl(rpc_pkt.u.reply.data[0]),
492 			       ntohl(rpc_pkt.u.reply.data[1]));
493 			break;
494 		default: /* Unknown error on 'accept state' flag */
495 			printf("*** ERROR: accept state error (%d)\n",
496 			       ntohl(rpc_pkt.u.reply.astatus));
497 			break;
498 		}
499 		return -1;
500 	}
501 
502 	memcpy(filefh, rpc_pkt.u.reply.data + 1, NFS_FHSIZE);
503 
504 	return 0;
505 }
506 
507 static int nfs_readlink_reply(uchar *pkt, unsigned len)
508 {
509 	struct rpc_t rpc_pkt;
510 	int rlen;
511 
512 	debug("%s\n", __func__);
513 
514 	memcpy((unsigned char *)&rpc_pkt, pkt, len);
515 
516 	if (ntohl(rpc_pkt.u.reply.id) > rpc_id)
517 		return -NFS_RPC_ERR;
518 	else if (ntohl(rpc_pkt.u.reply.id) < rpc_id)
519 		return -NFS_RPC_DROP;
520 
521 	if (rpc_pkt.u.reply.rstatus  ||
522 	    rpc_pkt.u.reply.verifier ||
523 	    rpc_pkt.u.reply.astatus  ||
524 	    rpc_pkt.u.reply.data[0])
525 		return -1;
526 
527 	rlen = ntohl(rpc_pkt.u.reply.data[1]); /* new path length */
528 
529 	if (*((char *)&(rpc_pkt.u.reply.data[2])) != '/') {
530 		int pathlen;
531 		strcat(nfs_path, "/");
532 		pathlen = strlen(nfs_path);
533 		memcpy(nfs_path + pathlen, (uchar *)&(rpc_pkt.u.reply.data[2]),
534 		       rlen);
535 		nfs_path[pathlen + rlen] = 0;
536 	} else {
537 		memcpy(nfs_path, (uchar *)&(rpc_pkt.u.reply.data[2]), rlen);
538 		nfs_path[rlen] = 0;
539 	}
540 	return 0;
541 }
542 
543 static int nfs_read_reply(uchar *pkt, unsigned len)
544 {
545 	struct rpc_t rpc_pkt;
546 	int rlen;
547 
548 	debug("%s\n", __func__);
549 
550 	memcpy((uchar *)&rpc_pkt, pkt, sizeof(rpc_pkt.u.reply));
551 
552 	if (ntohl(rpc_pkt.u.reply.id) > rpc_id)
553 		return -NFS_RPC_ERR;
554 	else if (ntohl(rpc_pkt.u.reply.id) < rpc_id)
555 		return -NFS_RPC_DROP;
556 
557 	if (rpc_pkt.u.reply.rstatus  ||
558 	    rpc_pkt.u.reply.verifier ||
559 	    rpc_pkt.u.reply.astatus  ||
560 	    rpc_pkt.u.reply.data[0]) {
561 		if (rpc_pkt.u.reply.rstatus)
562 			return -9999;
563 		if (rpc_pkt.u.reply.astatus)
564 			return -9999;
565 		return -ntohl(rpc_pkt.u.reply.data[0]);
566 	}
567 
568 	if ((nfs_offset != 0) && !((nfs_offset) %
569 			(NFS_READ_SIZE / 2 * 10 * HASHES_PER_LINE)))
570 		puts("\n\t ");
571 	if (!(nfs_offset % ((NFS_READ_SIZE / 2) * 10)))
572 		putc('#');
573 
574 	rlen = ntohl(rpc_pkt.u.reply.data[18]);
575 	if (store_block((uchar *)pkt + sizeof(rpc_pkt.u.reply),
576 			nfs_offset, rlen))
577 		return -9999;
578 
579 	return rlen;
580 }
581 
582 /**************************************************************************
583 Interfaces of U-BOOT
584 **************************************************************************/
585 static void nfs_timeout_handler(void)
586 {
587 	if (++nfs_timeout_count > NFS_RETRY_COUNT) {
588 		puts("\nRetry count exceeded; starting again\n");
589 		net_start_again();
590 	} else {
591 		puts("T ");
592 		net_set_timeout_handler(nfs_timeout +
593 					NFS_TIMEOUT * nfs_timeout_count,
594 					nfs_timeout_handler);
595 		nfs_send();
596 	}
597 }
598 
599 static void nfs_handler(uchar *pkt, unsigned dest, struct in_addr sip,
600 			unsigned src, unsigned len)
601 {
602 	int rlen;
603 	int reply;
604 
605 	debug("%s\n", __func__);
606 
607 	if (dest != nfs_our_port)
608 		return;
609 
610 	switch (nfs_state) {
611 	case STATE_PRCLOOKUP_PROG_MOUNT_REQ:
612 		if (rpc_lookup_reply(PROG_MOUNT, pkt, len) == -NFS_RPC_DROP)
613 			break;
614 		nfs_state = STATE_PRCLOOKUP_PROG_NFS_REQ;
615 		nfs_send();
616 		break;
617 
618 	case STATE_PRCLOOKUP_PROG_NFS_REQ:
619 		if (rpc_lookup_reply(PROG_NFS, pkt, len) == -NFS_RPC_DROP)
620 			break;
621 		nfs_state = STATE_MOUNT_REQ;
622 		nfs_send();
623 		break;
624 
625 	case STATE_MOUNT_REQ:
626 		reply = nfs_mount_reply(pkt, len);
627 		if (reply == -NFS_RPC_DROP) {
628 			break;
629 		} else if (reply == -NFS_RPC_ERR) {
630 			puts("*** ERROR: Cannot mount\n");
631 			/* just to be sure... */
632 			nfs_state = STATE_UMOUNT_REQ;
633 			nfs_send();
634 		} else {
635 			nfs_state = STATE_LOOKUP_REQ;
636 			nfs_send();
637 		}
638 		break;
639 
640 	case STATE_UMOUNT_REQ:
641 		reply = nfs_umountall_reply(pkt, len);
642 		if (reply == -NFS_RPC_DROP) {
643 			break;
644 		} else if (reply == -NFS_RPC_ERR) {
645 			puts("*** ERROR: Cannot umount\n");
646 			net_set_state(NETLOOP_FAIL);
647 		} else {
648 			puts("\ndone\n");
649 			net_set_state(nfs_download_state);
650 		}
651 		break;
652 
653 	case STATE_LOOKUP_REQ:
654 		reply = nfs_lookup_reply(pkt, len);
655 		if (reply == -NFS_RPC_DROP) {
656 			break;
657 		} else if (reply == -NFS_RPC_ERR) {
658 			puts("*** ERROR: File lookup fail\n");
659 			nfs_state = STATE_UMOUNT_REQ;
660 			nfs_send();
661 		} else {
662 			nfs_state = STATE_READ_REQ;
663 			nfs_offset = 0;
664 			nfs_len = NFS_READ_SIZE;
665 			nfs_send();
666 		}
667 		break;
668 
669 	case STATE_READLINK_REQ:
670 		reply = nfs_readlink_reply(pkt, len);
671 		if (reply == -NFS_RPC_DROP) {
672 			break;
673 		} else if (reply == -NFS_RPC_ERR) {
674 			puts("*** ERROR: Symlink fail\n");
675 			nfs_state = STATE_UMOUNT_REQ;
676 			nfs_send();
677 		} else {
678 			debug("Symlink --> %s\n", nfs_path);
679 			nfs_filename = basename(nfs_path);
680 			nfs_path     = dirname(nfs_path);
681 
682 			nfs_state = STATE_MOUNT_REQ;
683 			nfs_send();
684 		}
685 		break;
686 
687 	case STATE_READ_REQ:
688 		rlen = nfs_read_reply(pkt, len);
689 		net_set_timeout_handler(nfs_timeout, nfs_timeout_handler);
690 		if (rlen > 0) {
691 			nfs_offset += rlen;
692 			nfs_send();
693 		} else if ((rlen == -NFSERR_ISDIR) || (rlen == -NFSERR_INVAL)) {
694 			/* symbolic link */
695 			nfs_state = STATE_READLINK_REQ;
696 			nfs_send();
697 		} else {
698 			if (!rlen)
699 				nfs_download_state = NETLOOP_SUCCESS;
700 			nfs_state = STATE_UMOUNT_REQ;
701 			nfs_send();
702 		}
703 		break;
704 	}
705 }
706 
707 
708 void nfs_start(void)
709 {
710 	debug("%s\n", __func__);
711 	nfs_download_state = NETLOOP_FAIL;
712 
713 	nfs_server_ip = net_server_ip;
714 	nfs_path = (char *)nfs_path_buff;
715 
716 	if (nfs_path == NULL) {
717 		net_set_state(NETLOOP_FAIL);
718 		puts("*** ERROR: Fail allocate memory\n");
719 		return;
720 	}
721 
722 	if (net_boot_file_name[0] == '\0') {
723 		sprintf(default_filename, "/nfsroot/%02X%02X%02X%02X.img",
724 			net_ip.s_addr & 0xFF,
725 			(net_ip.s_addr >>  8) & 0xFF,
726 			(net_ip.s_addr >> 16) & 0xFF,
727 			(net_ip.s_addr >> 24) & 0xFF);
728 		strcpy(nfs_path, default_filename);
729 
730 		printf("*** Warning: no boot file name; using '%s'\n",
731 		       nfs_path);
732 	} else {
733 		char *p = net_boot_file_name;
734 
735 		p = strchr(p, ':');
736 
737 		if (p != NULL) {
738 			nfs_server_ip = string_to_ip(net_boot_file_name);
739 			++p;
740 			strcpy(nfs_path, p);
741 		} else {
742 			strcpy(nfs_path, net_boot_file_name);
743 		}
744 	}
745 
746 	nfs_filename = basename(nfs_path);
747 	nfs_path     = dirname(nfs_path);
748 
749 	printf("Using %s device\n", eth_get_name());
750 
751 	printf("File transfer via NFS from server %pI4; our IP address is %pI4",
752 	       &nfs_server_ip, &net_ip);
753 
754 	/* Check if we need to send across this subnet */
755 	if (net_gateway.s_addr && net_netmask.s_addr) {
756 		struct in_addr our_net;
757 		struct in_addr server_net;
758 
759 		our_net.s_addr = net_ip.s_addr & net_netmask.s_addr;
760 		server_net.s_addr = net_server_ip.s_addr & net_netmask.s_addr;
761 		if (our_net.s_addr != server_net.s_addr)
762 			printf("; sending through gateway %pI4",
763 			       &net_gateway);
764 	}
765 	printf("\nFilename '%s/%s'.", nfs_path, nfs_filename);
766 
767 	if (net_boot_file_expected_size_in_blocks) {
768 		printf(" Size is 0x%x Bytes = ",
769 		       net_boot_file_expected_size_in_blocks << 9);
770 		print_size(net_boot_file_expected_size_in_blocks << 9, "");
771 	}
772 	printf("\nLoad address: 0x%lx\n"
773 		"Loading: *\b", load_addr);
774 
775 	net_set_timeout_handler(nfs_timeout, nfs_timeout_handler);
776 	net_set_udp_handler(nfs_handler);
777 
778 	nfs_timeout_count = 0;
779 	nfs_state = STATE_PRCLOOKUP_PROG_MOUNT_REQ;
780 
781 	/*nfs_our_port = 4096 + (get_ticks() % 3072);*/
782 	/*FIX ME !!!*/
783 	nfs_our_port = 1000;
784 
785 	/* zero out server ether in case the server ip has changed */
786 	memset(net_server_ethaddr, 0, 6);
787 
788 	nfs_send();
789 }
790