xref: /rk3399_rockchip-uboot/net/nfs.c (revision f8b26c7adf4e097484a4679ac6f32ae11ce100c5)
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 *nfs_filename;
69 static char *nfs_path;
70 static char nfs_path_buff[2048];
71 
72 static inline int store_block(uchar *src, unsigned offset, unsigned len)
73 {
74 	ulong newsize = offset + len;
75 #ifdef CONFIG_SYS_DIRECT_FLASH_NFS
76 	int i, rc = 0;
77 
78 	for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; i++) {
79 		/* start address in flash? */
80 		if (load_addr + offset >= flash_info[i].start[0]) {
81 			rc = 1;
82 			break;
83 		}
84 	}
85 
86 	if (rc) { /* Flash is destination for this packet */
87 		rc = flash_write((uchar *)src, (ulong)(load_addr+offset), len);
88 		if (rc) {
89 			flash_perror(rc);
90 			return -1;
91 		}
92 	} else
93 #endif /* CONFIG_SYS_DIRECT_FLASH_NFS */
94 	{
95 		void *ptr = map_sysmem(load_addr + offset, len);
96 
97 		memcpy(ptr, src, len);
98 		unmap_sysmem(ptr);
99 	}
100 
101 	if (net_boot_file_size < (offset + len))
102 		net_boot_file_size = newsize;
103 	return 0;
104 }
105 
106 static char *basename(char *path)
107 {
108 	char *fname;
109 
110 	fname = path + strlen(path) - 1;
111 	while (fname >= path) {
112 		if (*fname == '/') {
113 			fname++;
114 			break;
115 		}
116 		fname--;
117 	}
118 	return fname;
119 }
120 
121 static char *dirname(char *path)
122 {
123 	char *fname;
124 
125 	fname = basename(path);
126 	--fname;
127 	*fname = '\0';
128 	return path;
129 }
130 
131 /**************************************************************************
132 RPC_ADD_CREDENTIALS - Add RPC authentication/verifier entries
133 **************************************************************************/
134 static uint32_t *rpc_add_credentials(uint32_t *p)
135 {
136 	int hl;
137 	int hostnamelen;
138 	char hostname[256];
139 
140 	strcpy(hostname, "");
141 	hostnamelen = strlen(hostname);
142 
143 	/* Here's the executive summary on authentication requirements of the
144 	 * various NFS server implementations:	Linux accepts both AUTH_NONE
145 	 * and AUTH_UNIX authentication (also accepts an empty hostname field
146 	 * in the AUTH_UNIX scheme).  *BSD refuses AUTH_NONE, but accepts
147 	 * AUTH_UNIX (also accepts an empty hostname field in the AUTH_UNIX
148 	 * scheme).  To be safe, use AUTH_UNIX and pass the hostname if we have
149 	 * it (if the BOOTP/DHCP reply didn't give one, just use an empty
150 	 * hostname).  */
151 
152 	hl = (hostnamelen + 3) & ~3;
153 
154 	/* Provide an AUTH_UNIX credential.  */
155 	*p++ = htonl(1);		/* AUTH_UNIX */
156 	*p++ = htonl(hl+20);		/* auth length */
157 	*p++ = htonl(0);		/* stamp */
158 	*p++ = htonl(hostnamelen);	/* hostname string */
159 	if (hostnamelen & 3)
160 		*(p + hostnamelen / 4) = 0; /* add zero padding */
161 	memcpy(p, hostname, hostnamelen);
162 	p += hl / 4;
163 	*p++ = 0;			/* uid */
164 	*p++ = 0;			/* gid */
165 	*p++ = 0;			/* auxiliary gid list */
166 
167 	/* Provide an AUTH_NONE verifier.  */
168 	*p++ = 0;			/* AUTH_NONE */
169 	*p++ = 0;			/* auth length */
170 
171 	return p;
172 }
173 
174 /**************************************************************************
175 RPC_LOOKUP - Lookup RPC Port numbers
176 **************************************************************************/
177 static void rpc_req(int rpc_prog, int rpc_proc, uint32_t *data, int datalen)
178 {
179 	struct rpc_t pkt;
180 	unsigned long id;
181 	uint32_t *p;
182 	int pktlen;
183 	int sport;
184 
185 	id = ++rpc_id;
186 	pkt.u.call.id = htonl(id);
187 	pkt.u.call.type = htonl(MSG_CALL);
188 	pkt.u.call.rpcvers = htonl(2);	/* use RPC version 2 */
189 	pkt.u.call.prog = htonl(rpc_prog);
190 	pkt.u.call.vers = htonl(2);	/* portmapper is version 2 */
191 	pkt.u.call.proc = htonl(rpc_proc);
192 	p = (uint32_t *)&(pkt.u.call.data);
193 
194 	if (datalen)
195 		memcpy((char *)p, (char *)data, datalen*sizeof(uint32_t));
196 
197 	pktlen = (char *)p + datalen*sizeof(uint32_t) - (char *)&pkt;
198 
199 	memcpy((char *)net_tx_packet + net_eth_hdr_size() + IP_UDP_HDR_SIZE,
200 	       (char *)&pkt, pktlen);
201 
202 	if (rpc_prog == PROG_PORTMAP)
203 		sport = SUNRPC_PORT;
204 	else if (rpc_prog == PROG_MOUNT)
205 		sport = nfs_server_mount_port;
206 	else
207 		sport = nfs_server_port;
208 
209 	net_send_udp_packet(net_server_ethaddr, nfs_server_ip, sport,
210 			    nfs_our_port, pktlen);
211 }
212 
213 /**************************************************************************
214 RPC_LOOKUP - Lookup RPC Port numbers
215 **************************************************************************/
216 static void rpc_lookup_req(int prog, int ver)
217 {
218 	uint32_t data[16];
219 
220 	data[0] = 0; data[1] = 0;	/* auth credential */
221 	data[2] = 0; data[3] = 0;	/* auth verifier */
222 	data[4] = htonl(prog);
223 	data[5] = htonl(ver);
224 	data[6] = htonl(17);	/* IP_UDP */
225 	data[7] = 0;
226 
227 	rpc_req(PROG_PORTMAP, PORTMAP_GETPORT, data, 8);
228 }
229 
230 /**************************************************************************
231 NFS_MOUNT - Mount an NFS Filesystem
232 **************************************************************************/
233 static void nfs_mount_req(char *path)
234 {
235 	uint32_t data[1024];
236 	uint32_t *p;
237 	int len;
238 	int pathlen;
239 
240 	pathlen = strlen(path);
241 
242 	p = &(data[0]);
243 	p = rpc_add_credentials(p);
244 
245 	*p++ = htonl(pathlen);
246 	if (pathlen & 3)
247 		*(p + pathlen / 4) = 0;
248 	memcpy(p, path, pathlen);
249 	p += (pathlen + 3) / 4;
250 
251 	len = (uint32_t *)p - (uint32_t *)&(data[0]);
252 
253 	rpc_req(PROG_MOUNT, MOUNT_ADDENTRY, data, len);
254 }
255 
256 /**************************************************************************
257 NFS_UMOUNTALL - Unmount all our NFS Filesystems on the Server
258 **************************************************************************/
259 static void nfs_umountall_req(void)
260 {
261 	uint32_t data[1024];
262 	uint32_t *p;
263 	int len;
264 
265 	if ((nfs_server_mount_port == -1) || (!fs_mounted))
266 		/* Nothing mounted, nothing to umount */
267 		return;
268 
269 	p = &(data[0]);
270 	p = rpc_add_credentials(p);
271 
272 	len = (uint32_t *)p - (uint32_t *)&(data[0]);
273 
274 	rpc_req(PROG_MOUNT, MOUNT_UMOUNTALL, data, len);
275 }
276 
277 /***************************************************************************
278  * NFS_READLINK (AH 2003-07-14)
279  * This procedure is called when read of the first block fails -
280  * this probably happens when it's a directory or a symlink
281  * In case of successful readlink(), the dirname is manipulated,
282  * so that inside the nfs() function a recursion can be done.
283  **************************************************************************/
284 static void nfs_readlink_req(void)
285 {
286 	uint32_t data[1024];
287 	uint32_t *p;
288 	int len;
289 
290 	p = &(data[0]);
291 	p = rpc_add_credentials(p);
292 
293 	memcpy(p, filefh, NFS_FHSIZE);
294 	p += (NFS_FHSIZE / 4);
295 
296 	len = (uint32_t *)p - (uint32_t *)&(data[0]);
297 
298 	rpc_req(PROG_NFS, NFS_READLINK, data, len);
299 }
300 
301 /**************************************************************************
302 NFS_LOOKUP - Lookup Pathname
303 **************************************************************************/
304 static void nfs_lookup_req(char *fname)
305 {
306 	uint32_t data[1024];
307 	uint32_t *p;
308 	int len;
309 	int fnamelen;
310 
311 	fnamelen = strlen(fname);
312 
313 	p = &(data[0]);
314 	p = rpc_add_credentials(p);
315 
316 	memcpy(p, dirfh, NFS_FHSIZE);
317 	p += (NFS_FHSIZE / 4);
318 	*p++ = htonl(fnamelen);
319 	if (fnamelen & 3)
320 		*(p + fnamelen / 4) = 0;
321 	memcpy(p, fname, fnamelen);
322 	p += (fnamelen + 3) / 4;
323 
324 	len = (uint32_t *)p - (uint32_t *)&(data[0]);
325 
326 	rpc_req(PROG_NFS, NFS_LOOKUP, data, len);
327 }
328 
329 /**************************************************************************
330 NFS_READ - Read File on NFS Server
331 **************************************************************************/
332 static void nfs_read_req(int offset, int readlen)
333 {
334 	uint32_t data[1024];
335 	uint32_t *p;
336 	int len;
337 
338 	p = &(data[0]);
339 	p = rpc_add_credentials(p);
340 
341 	memcpy(p, filefh, NFS_FHSIZE);
342 	p += (NFS_FHSIZE / 4);
343 	*p++ = htonl(offset);
344 	*p++ = htonl(readlen);
345 	*p++ = 0;
346 
347 	len = (uint32_t *)p - (uint32_t *)&(data[0]);
348 
349 	rpc_req(PROG_NFS, NFS_READ, data, len);
350 }
351 
352 /**************************************************************************
353 RPC request dispatcher
354 **************************************************************************/
355 static void nfs_send(void)
356 {
357 	debug("%s\n", __func__);
358 
359 	switch (nfs_state) {
360 	case STATE_PRCLOOKUP_PROG_MOUNT_REQ:
361 		rpc_lookup_req(PROG_MOUNT, 1);
362 		break;
363 	case STATE_PRCLOOKUP_PROG_NFS_REQ:
364 		rpc_lookup_req(PROG_NFS, 2);
365 		break;
366 	case STATE_MOUNT_REQ:
367 		nfs_mount_req(nfs_path);
368 		break;
369 	case STATE_UMOUNT_REQ:
370 		nfs_umountall_req();
371 		break;
372 	case STATE_LOOKUP_REQ:
373 		nfs_lookup_req(nfs_filename);
374 		break;
375 	case STATE_READ_REQ:
376 		nfs_read_req(nfs_offset, nfs_len);
377 		break;
378 	case STATE_READLINK_REQ:
379 		nfs_readlink_req();
380 		break;
381 	}
382 }
383 
384 /**************************************************************************
385 Handlers for the reply from server
386 **************************************************************************/
387 
388 static int rpc_lookup_reply(int prog, uchar *pkt, unsigned len)
389 {
390 	struct rpc_t rpc_pkt;
391 
392 	memcpy((unsigned char *)&rpc_pkt, pkt, len);
393 
394 	debug("%s\n", __func__);
395 
396 	if (ntohl(rpc_pkt.u.reply.id) > rpc_id)
397 		return -NFS_RPC_ERR;
398 	else if (ntohl(rpc_pkt.u.reply.id) < rpc_id)
399 		return -NFS_RPC_DROP;
400 
401 	if (rpc_pkt.u.reply.rstatus  ||
402 	    rpc_pkt.u.reply.verifier ||
403 	    rpc_pkt.u.reply.astatus)
404 		return -1;
405 
406 	switch (prog) {
407 	case PROG_MOUNT:
408 		nfs_server_mount_port = ntohl(rpc_pkt.u.reply.data[0]);
409 		break;
410 	case PROG_NFS:
411 		nfs_server_port = ntohl(rpc_pkt.u.reply.data[0]);
412 		break;
413 	}
414 
415 	return 0;
416 }
417 
418 static int nfs_mount_reply(uchar *pkt, unsigned len)
419 {
420 	struct rpc_t rpc_pkt;
421 
422 	debug("%s\n", __func__);
423 
424 	memcpy((unsigned char *)&rpc_pkt, pkt, len);
425 
426 	if (ntohl(rpc_pkt.u.reply.id) > rpc_id)
427 		return -NFS_RPC_ERR;
428 	else if (ntohl(rpc_pkt.u.reply.id) < rpc_id)
429 		return -NFS_RPC_DROP;
430 
431 	if (rpc_pkt.u.reply.rstatus  ||
432 	    rpc_pkt.u.reply.verifier ||
433 	    rpc_pkt.u.reply.astatus  ||
434 	    rpc_pkt.u.reply.data[0])
435 		return -1;
436 
437 	fs_mounted = 1;
438 	memcpy(dirfh, rpc_pkt.u.reply.data + 1, NFS_FHSIZE);
439 
440 	return 0;
441 }
442 
443 static int nfs_umountall_reply(uchar *pkt, unsigned len)
444 {
445 	struct rpc_t rpc_pkt;
446 
447 	debug("%s\n", __func__);
448 
449 	memcpy((unsigned char *)&rpc_pkt, pkt, len);
450 
451 	if (ntohl(rpc_pkt.u.reply.id) > rpc_id)
452 		return -NFS_RPC_ERR;
453 	else if (ntohl(rpc_pkt.u.reply.id) < rpc_id)
454 		return -NFS_RPC_DROP;
455 
456 	if (rpc_pkt.u.reply.rstatus  ||
457 	    rpc_pkt.u.reply.verifier ||
458 	    rpc_pkt.u.reply.astatus)
459 		return -1;
460 
461 	fs_mounted = 0;
462 	memset(dirfh, 0, sizeof(dirfh));
463 
464 	return 0;
465 }
466 
467 static int nfs_lookup_reply(uchar *pkt, unsigned len)
468 {
469 	struct rpc_t rpc_pkt;
470 
471 	debug("%s\n", __func__);
472 
473 	memcpy((unsigned char *)&rpc_pkt, pkt, len);
474 
475 	if (ntohl(rpc_pkt.u.reply.id) > rpc_id)
476 		return -NFS_RPC_ERR;
477 	else if (ntohl(rpc_pkt.u.reply.id) < rpc_id)
478 		return -NFS_RPC_DROP;
479 
480 	if (rpc_pkt.u.reply.rstatus  ||
481 	    rpc_pkt.u.reply.verifier ||
482 	    rpc_pkt.u.reply.astatus  ||
483 	    rpc_pkt.u.reply.data[0]) {
484 		switch (ntohl(rpc_pkt.u.reply.astatus)) {
485 		case 0: /* Not an error */
486 			break;
487 		case 2: /* Remote can't support NFS version */
488 			printf("*** ERROR: NFS version not supported: Requested: V%d, accepted: min V%d - max V%d\n",
489 			       2,
490 			       ntohl(rpc_pkt.u.reply.data[0]),
491 			       ntohl(rpc_pkt.u.reply.data[1]));
492 			break;
493 		default: /* Unknown error on 'accept state' flag */
494 			printf("*** ERROR: accept state error (%d)\n",
495 			       ntohl(rpc_pkt.u.reply.astatus));
496 			break;
497 		}
498 		return -1;
499 	}
500 
501 	memcpy(filefh, rpc_pkt.u.reply.data + 1, NFS_FHSIZE);
502 
503 	return 0;
504 }
505 
506 static int nfs_readlink_reply(uchar *pkt, unsigned len)
507 {
508 	struct rpc_t rpc_pkt;
509 	int rlen;
510 
511 	debug("%s\n", __func__);
512 
513 	memcpy((unsigned char *)&rpc_pkt, pkt, len);
514 
515 	if (ntohl(rpc_pkt.u.reply.id) > rpc_id)
516 		return -NFS_RPC_ERR;
517 	else if (ntohl(rpc_pkt.u.reply.id) < rpc_id)
518 		return -NFS_RPC_DROP;
519 
520 	if (rpc_pkt.u.reply.rstatus  ||
521 	    rpc_pkt.u.reply.verifier ||
522 	    rpc_pkt.u.reply.astatus  ||
523 	    rpc_pkt.u.reply.data[0])
524 		return -1;
525 
526 	rlen = ntohl(rpc_pkt.u.reply.data[1]); /* new path length */
527 
528 	if (*((char *)&(rpc_pkt.u.reply.data[2])) != '/') {
529 		int pathlen;
530 		strcat(nfs_path, "/");
531 		pathlen = strlen(nfs_path);
532 		memcpy(nfs_path + pathlen, (uchar *)&(rpc_pkt.u.reply.data[2]),
533 		       rlen);
534 		nfs_path[pathlen + rlen] = 0;
535 	} else {
536 		memcpy(nfs_path, (uchar *)&(rpc_pkt.u.reply.data[2]), rlen);
537 		nfs_path[rlen] = 0;
538 	}
539 	return 0;
540 }
541 
542 static int nfs_read_reply(uchar *pkt, unsigned len)
543 {
544 	struct rpc_t rpc_pkt;
545 	int rlen;
546 
547 	debug("%s\n", __func__);
548 
549 	memcpy((uchar *)&rpc_pkt, pkt, sizeof(rpc_pkt.u.reply));
550 
551 	if (ntohl(rpc_pkt.u.reply.id) > rpc_id)
552 		return -NFS_RPC_ERR;
553 	else if (ntohl(rpc_pkt.u.reply.id) < rpc_id)
554 		return -NFS_RPC_DROP;
555 
556 	if (rpc_pkt.u.reply.rstatus  ||
557 	    rpc_pkt.u.reply.verifier ||
558 	    rpc_pkt.u.reply.astatus  ||
559 	    rpc_pkt.u.reply.data[0]) {
560 		if (rpc_pkt.u.reply.rstatus)
561 			return -9999;
562 		if (rpc_pkt.u.reply.astatus)
563 			return -9999;
564 		return -ntohl(rpc_pkt.u.reply.data[0]);
565 	}
566 
567 	if ((nfs_offset != 0) && !((nfs_offset) %
568 			(NFS_READ_SIZE / 2 * 10 * HASHES_PER_LINE)))
569 		puts("\n\t ");
570 	if (!(nfs_offset % ((NFS_READ_SIZE / 2) * 10)))
571 		putc('#');
572 
573 	rlen = ntohl(rpc_pkt.u.reply.data[18]);
574 	if (store_block((uchar *)pkt + sizeof(rpc_pkt.u.reply),
575 			nfs_offset, rlen))
576 		return -9999;
577 
578 	return rlen;
579 }
580 
581 /**************************************************************************
582 Interfaces of U-BOOT
583 **************************************************************************/
584 static void nfs_timeout_handler(void)
585 {
586 	if (++nfs_timeout_count > NFS_RETRY_COUNT) {
587 		puts("\nRetry count exceeded; starting again\n");
588 		net_start_again();
589 	} else {
590 		puts("T ");
591 		net_set_timeout_handler(nfs_timeout +
592 					NFS_TIMEOUT * nfs_timeout_count,
593 					nfs_timeout_handler);
594 		nfs_send();
595 	}
596 }
597 
598 static void nfs_handler(uchar *pkt, unsigned dest, struct in_addr sip,
599 			unsigned src, unsigned len)
600 {
601 	int rlen;
602 	int reply;
603 
604 	debug("%s\n", __func__);
605 
606 	if (dest != nfs_our_port)
607 		return;
608 
609 	switch (nfs_state) {
610 	case STATE_PRCLOOKUP_PROG_MOUNT_REQ:
611 		if (rpc_lookup_reply(PROG_MOUNT, pkt, len) == -NFS_RPC_DROP)
612 			break;
613 		nfs_state = STATE_PRCLOOKUP_PROG_NFS_REQ;
614 		nfs_send();
615 		break;
616 
617 	case STATE_PRCLOOKUP_PROG_NFS_REQ:
618 		if (rpc_lookup_reply(PROG_NFS, pkt, len) == -NFS_RPC_DROP)
619 			break;
620 		nfs_state = STATE_MOUNT_REQ;
621 		nfs_send();
622 		break;
623 
624 	case STATE_MOUNT_REQ:
625 		reply = nfs_mount_reply(pkt, len);
626 		if (reply == -NFS_RPC_DROP) {
627 			break;
628 		} else if (reply == -NFS_RPC_ERR) {
629 			puts("*** ERROR: Cannot mount\n");
630 			/* just to be sure... */
631 			nfs_state = STATE_UMOUNT_REQ;
632 			nfs_send();
633 		} else {
634 			nfs_state = STATE_LOOKUP_REQ;
635 			nfs_send();
636 		}
637 		break;
638 
639 	case STATE_UMOUNT_REQ:
640 		reply = nfs_umountall_reply(pkt, len);
641 		if (reply == -NFS_RPC_DROP) {
642 			break;
643 		} else if (reply == -NFS_RPC_ERR) {
644 			puts("*** ERROR: Cannot umount\n");
645 			net_set_state(NETLOOP_FAIL);
646 		} else {
647 			puts("\ndone\n");
648 			net_set_state(nfs_download_state);
649 		}
650 		break;
651 
652 	case STATE_LOOKUP_REQ:
653 		reply = nfs_lookup_reply(pkt, len);
654 		if (reply == -NFS_RPC_DROP) {
655 			break;
656 		} else if (reply == -NFS_RPC_ERR) {
657 			puts("*** ERROR: File lookup fail\n");
658 			nfs_state = STATE_UMOUNT_REQ;
659 			nfs_send();
660 		} else {
661 			nfs_state = STATE_READ_REQ;
662 			nfs_offset = 0;
663 			nfs_len = NFS_READ_SIZE;
664 			nfs_send();
665 		}
666 		break;
667 
668 	case STATE_READLINK_REQ:
669 		reply = nfs_readlink_reply(pkt, len);
670 		if (reply == -NFS_RPC_DROP) {
671 			break;
672 		} else if (reply == -NFS_RPC_ERR) {
673 			puts("*** ERROR: Symlink fail\n");
674 			nfs_state = STATE_UMOUNT_REQ;
675 			nfs_send();
676 		} else {
677 			debug("Symlink --> %s\n", nfs_path);
678 			nfs_filename = basename(nfs_path);
679 			nfs_path     = dirname(nfs_path);
680 
681 			nfs_state = STATE_MOUNT_REQ;
682 			nfs_send();
683 		}
684 		break;
685 
686 	case STATE_READ_REQ:
687 		rlen = nfs_read_reply(pkt, len);
688 		net_set_timeout_handler(nfs_timeout, nfs_timeout_handler);
689 		if (rlen > 0) {
690 			nfs_offset += rlen;
691 			nfs_send();
692 		} else if ((rlen == -NFSERR_ISDIR) || (rlen == -NFSERR_INVAL)) {
693 			/* symbolic link */
694 			nfs_state = STATE_READLINK_REQ;
695 			nfs_send();
696 		} else {
697 			if (!rlen)
698 				nfs_download_state = NETLOOP_SUCCESS;
699 			nfs_state = STATE_UMOUNT_REQ;
700 			nfs_send();
701 		}
702 		break;
703 	}
704 }
705 
706 
707 void nfs_start(void)
708 {
709 	debug("%s\n", __func__);
710 	nfs_download_state = NETLOOP_FAIL;
711 
712 	nfs_server_ip = net_server_ip;
713 	nfs_path = (char *)nfs_path_buff;
714 
715 	if (nfs_path == NULL) {
716 		net_set_state(NETLOOP_FAIL);
717 		puts("*** ERROR: Fail allocate memory\n");
718 		return;
719 	}
720 
721 	if (net_boot_file_name[0] == '\0') {
722 		sprintf(nfs_path, "/nfsroot/%02X%02X%02X%02X.img",
723 			net_ip.s_addr & 0xFF,
724 			(net_ip.s_addr >>  8) & 0xFF,
725 			(net_ip.s_addr >> 16) & 0xFF,
726 			(net_ip.s_addr >> 24) & 0xFF);
727 
728 		printf("*** Warning: no boot file name; using '%s'\n",
729 		       nfs_path);
730 	} else {
731 		char *p = net_boot_file_name;
732 
733 		p = strchr(p, ':');
734 
735 		if (p != NULL) {
736 			nfs_server_ip = string_to_ip(net_boot_file_name);
737 			++p;
738 			strcpy(nfs_path, p);
739 		} else {
740 			strcpy(nfs_path, net_boot_file_name);
741 		}
742 	}
743 
744 	nfs_filename = basename(nfs_path);
745 	nfs_path     = dirname(nfs_path);
746 
747 	printf("Using %s device\n", eth_get_name());
748 
749 	printf("File transfer via NFS from server %pI4; our IP address is %pI4",
750 	       &nfs_server_ip, &net_ip);
751 
752 	/* Check if we need to send across this subnet */
753 	if (net_gateway.s_addr && net_netmask.s_addr) {
754 		struct in_addr our_net;
755 		struct in_addr server_net;
756 
757 		our_net.s_addr = net_ip.s_addr & net_netmask.s_addr;
758 		server_net.s_addr = net_server_ip.s_addr & net_netmask.s_addr;
759 		if (our_net.s_addr != server_net.s_addr)
760 			printf("; sending through gateway %pI4",
761 			       &net_gateway);
762 	}
763 	printf("\nFilename '%s/%s'.", nfs_path, nfs_filename);
764 
765 	if (net_boot_file_expected_size_in_blocks) {
766 		printf(" Size is 0x%x Bytes = ",
767 		       net_boot_file_expected_size_in_blocks << 9);
768 		print_size(net_boot_file_expected_size_in_blocks << 9, "");
769 	}
770 	printf("\nLoad address: 0x%lx\n"
771 		"Loading: *\b", load_addr);
772 
773 	net_set_timeout_handler(nfs_timeout, nfs_timeout_handler);
774 	net_set_udp_handler(nfs_handler);
775 
776 	nfs_timeout_count = 0;
777 	nfs_state = STATE_PRCLOOKUP_PROG_MOUNT_REQ;
778 
779 	/*nfs_our_port = 4096 + (get_ticks() % 3072);*/
780 	/*FIX ME !!!*/
781 	nfs_our_port = 1000;
782 
783 	/* zero out server ether in case the server ip has changed */
784 	memset(net_server_ethaddr, 0, 6);
785 
786 	nfs_send();
787 }
788