pxe.c revision 212126 
1/*-
2 * Copyright (c) 2000 Alfred Perlstein <alfred@freebsd.org>
3 * Copyright (c) 2000 Paul Saab <ps@freebsd.org>
4 * Copyright (c) 2000 John Baldwin <jhb@freebsd.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD: head/sys/boot/i386/libi386/pxe.c 212126 2010-09-02 01:05:10Z rmacklem $");
31
32#include <stand.h>
33#include <string.h>
34#include <stdarg.h>
35
36#include <netinet/in_systm.h>
37#include <netinet/in.h>
38#include <netinet/udp.h>
39
40#include <net.h>
41#include <netif.h>
42#include <nfsv2.h>
43#include <iodesc.h>
44
45#include <bootp.h>
46#include <bootstrap.h>
47#include "btxv86.h"
48#include "pxe.h"
49
50/*
51 * Allocate the PXE buffers statically instead of sticking grimy fingers into
52 * BTX's private data area.  The scratch buffer is used to send information to
53 * the PXE BIOS, and the data buffer is used to receive data from the PXE BIOS.
54 */
55#define	PXE_BUFFER_SIZE		0x2000
56#define	PXE_TFTP_BUFFER_SIZE	512
57static char	scratch_buffer[PXE_BUFFER_SIZE];
58static char	data_buffer[PXE_BUFFER_SIZE];
59
60static pxenv_t	*pxenv_p = NULL;        /* PXENV+ */
61static pxe_t	*pxe_p   = NULL;	/* !PXE */
62static BOOTPLAYER	bootplayer;	/* PXE Cached information. */
63
64static int 	pxe_debug = 0;
65static int	pxe_sock = -1;
66static int	pxe_opens = 0;
67
68void		pxe_enable(void *pxeinfo);
69static void	(*pxe_call)(int func);
70static void	pxenv_call(int func);
71static void	bangpxe_call(int func);
72
73static int	pxe_init(void);
74static int	pxe_strategy(void *devdata, int flag, daddr_t dblk,
75			     size_t size, char *buf, size_t *rsize);
76static int	pxe_open(struct open_file *f, ...);
77static int	pxe_close(struct open_file *f);
78static void	pxe_print(int verbose);
79static void	pxe_cleanup(void);
80static void	pxe_setnfshandle(char *rootpath);
81
82static void	pxe_perror(int error);
83static int	pxe_netif_match(struct netif *nif, void *machdep_hint);
84static int	pxe_netif_probe(struct netif *nif, void *machdep_hint);
85static void	pxe_netif_init(struct iodesc *desc, void *machdep_hint);
86static int	pxe_netif_get(struct iodesc *desc, void *pkt, size_t len,
87			      time_t timeout);
88static int	pxe_netif_put(struct iodesc *desc, void *pkt, size_t len);
89static void	pxe_netif_end(struct netif *nif);
90
91extern struct netif_stats	pxe_st[];
92extern u_int16_t		__bangpxeseg;
93extern u_int16_t		__bangpxeoff;
94extern void			__bangpxeentry(void);
95extern u_int16_t		__pxenvseg;
96extern u_int16_t		__pxenvoff;
97extern void			__pxenventry(void);
98
99struct netif_dif pxe_ifs[] = {
100/*      dif_unit        dif_nsel        dif_stats       dif_private     */
101	{0,             1,              &pxe_st[0],     0}
102};
103
104struct netif_stats pxe_st[NENTS(pxe_ifs)];
105
106struct netif_driver pxenetif = {
107	"pxenet",
108	pxe_netif_match,
109	pxe_netif_probe,
110	pxe_netif_init,
111	pxe_netif_get,
112	pxe_netif_put,
113	pxe_netif_end,
114	pxe_ifs,
115	NENTS(pxe_ifs)
116};
117
118struct netif_driver *netif_drivers[] = {
119	&pxenetif,
120	NULL
121};
122
123struct devsw pxedisk = {
124	"pxe",
125	DEVT_NET,
126	pxe_init,
127	pxe_strategy,
128	pxe_open,
129	pxe_close,
130	noioctl,
131	pxe_print,
132	pxe_cleanup
133};
134
135/*
136 * This function is called by the loader to enable PXE support if we
137 * are booted by PXE.  The passed in pointer is a pointer to the
138 * PXENV+ structure.
139 */
140void
141pxe_enable(void *pxeinfo)
142{
143	pxenv_p  = (pxenv_t *)pxeinfo;
144	pxe_p    = (pxe_t *)PTOV(pxenv_p->PXEPtr.segment * 16 +
145				 pxenv_p->PXEPtr.offset);
146	pxe_call = NULL;
147}
148
149/*
150 * return true if pxe structures are found/initialized,
151 * also figures out our IP information via the pxe cached info struct
152 */
153static int
154pxe_init(void)
155{
156	t_PXENV_GET_CACHED_INFO	*gci_p;
157	int	counter;
158	uint8_t checksum;
159	uint8_t *checkptr;
160
161	if(pxenv_p == NULL)
162		return (0);
163
164	/*  look for "PXENV+" */
165	if (bcmp((void *)pxenv_p->Signature, S_SIZE("PXENV+"))) {
166		pxenv_p = NULL;
167		return (0);
168	}
169
170	/* make sure the size is something we can handle */
171	if (pxenv_p->Length > sizeof(*pxenv_p)) {
172	  	printf("PXENV+ structure too large, ignoring\n");
173		pxenv_p = NULL;
174		return (0);
175	}
176
177	/*
178	 * do byte checksum:
179	 * add up each byte in the structure, the total should be 0
180	 */
181	checksum = 0;
182	checkptr = (uint8_t *) pxenv_p;
183	for (counter = 0; counter < pxenv_p->Length; counter++)
184		checksum += *checkptr++;
185	if (checksum != 0) {
186		printf("PXENV+ structure failed checksum, ignoring\n");
187		pxenv_p = NULL;
188		return (0);
189	}
190
191
192	/*
193	 * PXENV+ passed, so use that if !PXE is not available or
194	 * the checksum fails.
195	 */
196	pxe_call = pxenv_call;
197	if (pxenv_p->Version >= 0x0200) {
198		for (;;) {
199			if (bcmp((void *)pxe_p->Signature, S_SIZE("!PXE"))) {
200				pxe_p = NULL;
201				break;
202			}
203			checksum = 0;
204			checkptr = (uint8_t *)pxe_p;
205			for (counter = 0; counter < pxe_p->StructLength;
206			     counter++)
207				checksum += *checkptr++;
208			if (checksum != 0) {
209				pxe_p = NULL;
210				break;
211			}
212			pxe_call = bangpxe_call;
213			break;
214		}
215	}
216
217	printf("\nPXE version %d.%d, real mode entry point ",
218	       (uint8_t) (pxenv_p->Version >> 8),
219	       (uint8_t) (pxenv_p->Version & 0xFF));
220	if (pxe_call == bangpxe_call)
221		printf("@%04x:%04x\n",
222		       pxe_p->EntryPointSP.segment,
223		       pxe_p->EntryPointSP.offset);
224	else
225		printf("@%04x:%04x\n",
226		       pxenv_p->RMEntry.segment, pxenv_p->RMEntry.offset);
227
228	gci_p = (t_PXENV_GET_CACHED_INFO *) scratch_buffer;
229	bzero(gci_p, sizeof(*gci_p));
230	gci_p->PacketType =  PXENV_PACKET_TYPE_BINL_REPLY;
231	pxe_call(PXENV_GET_CACHED_INFO);
232	if (gci_p->Status != 0) {
233		pxe_perror(gci_p->Status);
234		pxe_p = NULL;
235		return (0);
236	}
237	bcopy(PTOV((gci_p->Buffer.segment << 4) + gci_p->Buffer.offset),
238	      &bootplayer, gci_p->BufferSize);
239	return (1);
240}
241
242
243static int
244pxe_strategy(void *devdata, int flag, daddr_t dblk, size_t size,
245		char *buf, size_t *rsize)
246{
247	return (EIO);
248}
249
250static int
251pxe_open(struct open_file *f, ...)
252{
253    va_list args;
254    char *devname;		/* Device part of file name (or NULL). */
255    char temp[FNAME_SIZE];
256    int error = 0;
257    int i;
258
259    va_start(args, f);
260    devname = va_arg(args, char*);
261    va_end(args);
262
263    /* On first open, do netif open, mount, etc. */
264    if (pxe_opens == 0) {
265	/* Find network interface. */
266	if (pxe_sock < 0) {
267	    pxe_sock = netif_open(devname);
268	    if (pxe_sock < 0) {
269		printf("pxe_open: netif_open() failed\n");
270		return (ENXIO);
271	    }
272	    if (pxe_debug)
273		printf("pxe_open: netif_open() succeeded\n");
274	}
275	if (rootip.s_addr == 0) {
276		/*
277		 * Do a bootp/dhcp request to find out where our
278		 * NFS/TFTP server is.  Even if we dont get back
279		 * the proper information, fall back to the server
280		 * which brought us to life and a default rootpath.
281		 */
282		bootp(pxe_sock, BOOTP_PXE);
283		if (rootip.s_addr == 0)
284			rootip.s_addr = bootplayer.sip;
285		if (!rootpath[0])
286			strcpy(rootpath, PXENFSROOTPATH);
287
288		for (i = 0; rootpath[i] != '\0' && i < FNAME_SIZE; i++)
289			if (rootpath[i] == ':')
290				break;
291		if (i && i != FNAME_SIZE && rootpath[i] == ':') {
292			rootpath[i++] = '\0';
293			if (inet_addr(&rootpath[0]) != INADDR_NONE)
294				rootip.s_addr = inet_addr(&rootpath[0]);
295			bcopy(&rootpath[i], &temp[0], strlen(&rootpath[i])+1);
296			bcopy(&temp[0], &rootpath[0], strlen(&rootpath[i])+1);
297		}
298		printf("pxe_open: server addr: %s\n", inet_ntoa(rootip));
299		printf("pxe_open: server path: %s\n", rootpath);
300		printf("pxe_open: gateway ip:  %s\n", inet_ntoa(gateip));
301
302		setenv("boot.netif.ip", inet_ntoa(myip), 1);
303		setenv("boot.netif.netmask", intoa(netmask), 1);
304		setenv("boot.netif.gateway", inet_ntoa(gateip), 1);
305		if (bootplayer.Hardware == ETHER_TYPE) {
306		    sprintf(temp, "%6D", bootplayer.CAddr, ":");
307		    setenv("boot.netif.hwaddr", temp, 1);
308		}
309		setenv("boot.nfsroot.server", inet_ntoa(rootip), 1);
310		setenv("boot.nfsroot.path", rootpath, 1);
311		setenv("dhcp.host-name", hostname, 1);
312	}
313    }
314    pxe_opens++;
315    f->f_devdata = &pxe_sock;
316    return (error);
317}
318
319static int
320pxe_close(struct open_file *f)
321{
322
323#ifdef	PXE_DEBUG
324    if (pxe_debug)
325	printf("pxe_close: opens=%d\n", pxe_opens);
326#endif
327
328    /* On last close, do netif close, etc. */
329    f->f_devdata = NULL;
330    /* Extra close call? */
331    if (pxe_opens <= 0)
332	return (0);
333    pxe_opens--;
334    /* Not last close? */
335    if (pxe_opens > 0)
336	return(0);
337
338#ifdef LOADER_NFS_SUPPORT
339    /* get an NFS filehandle for our root filesystem */
340    pxe_setnfshandle(rootpath);
341#endif
342
343    if (pxe_sock >= 0) {
344
345#ifdef PXE_DEBUG
346	if (pxe_debug)
347	    printf("pxe_close: calling netif_close()\n");
348#endif
349	netif_close(pxe_sock);
350	pxe_sock = -1;
351    }
352    return (0);
353}
354
355static void
356pxe_print(int verbose)
357{
358	if (pxe_call != NULL) {
359		if (*bootplayer.Sname == '\0') {
360			printf("      "IP_STR":%s\n",
361			       IP_ARGS(htonl(bootplayer.sip)),
362			       bootplayer.bootfile);
363		} else {
364			printf("      %s:%s\n", bootplayer.Sname,
365			       bootplayer.bootfile);
366		}
367	}
368
369	return;
370}
371
372static void
373pxe_cleanup(void)
374{
375#ifdef PXE_DEBUG
376	t_PXENV_UNLOAD_STACK *unload_stack_p =
377	    (t_PXENV_UNLOAD_STACK *)scratch_buffer;
378	t_PXENV_UNDI_SHUTDOWN *undi_shutdown_p =
379	    (t_PXENV_UNDI_SHUTDOWN *)scratch_buffer;
380#endif
381
382	if (pxe_call == NULL)
383		return;
384
385	pxe_call(PXENV_UNDI_SHUTDOWN);
386
387#ifdef PXE_DEBUG
388	if (pxe_debug && undi_shutdown_p->Status != 0)
389		printf("pxe_cleanup: UNDI_SHUTDOWN failed %x\n",
390		       undi_shutdown_p->Status);
391#endif
392
393	pxe_call(PXENV_UNLOAD_STACK);
394
395#ifdef PXE_DEBUG
396	if (pxe_debug && unload_stack_p->Status != 0)
397		printf("pxe_cleanup: UNLOAD_STACK failed %x\n",
398		    unload_stack_p->Status);
399#endif
400}
401
402void
403pxe_perror(int err)
404{
405	return;
406}
407
408/*
409 * Reach inside the libstand NFS code and dig out an NFS handle
410 * for the root filesystem.
411 */
412#ifdef OLD_NFSV2
413struct nfs_iodesc {
414	struct	iodesc	*iodesc;
415	off_t	off;
416	u_char	fh[NFS_FHSIZE];
417	/* structure truncated here */
418};
419extern struct	nfs_iodesc nfs_root_node;
420extern int      rpc_port;
421
422static void
423pxe_rpcmountcall()
424{
425	struct	iodesc *d;
426	int     error;
427
428	if (!(d = socktodesc(pxe_sock)))
429		return;
430        d->myport = htons(--rpc_port);
431        d->destip = rootip;
432	if ((error = nfs_getrootfh(d, rootpath, nfs_root_node.fh)) != 0)
433		printf("NFS MOUNT RPC error: %d\n", error);
434	nfs_root_node.iodesc = d;
435}
436
437static void
438pxe_setnfshandle(char *rootpath)
439{
440	int	i;
441	u_char	*fh;
442	char	buf[2 * NFS_FHSIZE + 3], *cp;
443
444	/*
445	 * If NFS files were never opened, we need to do mount call
446	 * ourselves. Use nfs_root_node.iodesc as flag indicating
447	 * previous NFS usage.
448	 */
449	if (nfs_root_node.iodesc == NULL)
450		pxe_rpcmountcall();
451
452	fh = &nfs_root_node.fh[0];
453	buf[0] = 'X';
454	cp = &buf[1];
455	for (i = 0; i < NFS_FHSIZE; i++, cp += 2)
456		sprintf(cp, "%02x", fh[i]);
457	sprintf(cp, "X");
458	setenv("boot.nfsroot.nfshandle", buf, 1);
459}
460#else	/* !OLD_NFSV2 */
461
462#define	NFS_V3MAXFHSIZE		64
463
464struct nfs_iodesc {
465	struct iodesc *iodesc;
466	off_t off;
467	uint32_t fhsize;
468	u_char fh[NFS_V3MAXFHSIZE];
469	/* structure truncated */
470};
471extern struct nfs_iodesc nfs_root_node;
472extern int rpc_port;
473
474static void
475pxe_rpcmountcall()
476{
477	struct iodesc *d;
478	int error;
479
480	if (!(d = socktodesc(pxe_sock)))
481		return;
482        d->myport = htons(--rpc_port);
483        d->destip = rootip;
484	if ((error = nfs_getrootfh(d, rootpath, &nfs_root_node.fhsize,
485	    nfs_root_node.fh)) != 0) {
486		printf("NFS MOUNT RPC error: %d\n", error);
487		nfs_root_node.fhsize = 0;
488	}
489	nfs_root_node.iodesc = d;
490}
491
492static void
493pxe_setnfshandle(char *rootpath)
494{
495	int i;
496	u_char *fh;
497	char buf[2 * NFS_V3MAXFHSIZE + 3], *cp;
498
499	/*
500	 * If NFS files were never opened, we need to do mount call
501	 * ourselves. Use nfs_root_node.iodesc as flag indicating
502	 * previous NFS usage.
503	 */
504	if (nfs_root_node.iodesc == NULL)
505		pxe_rpcmountcall();
506
507	fh = &nfs_root_node.fh[0];
508	buf[0] = 'X';
509	cp = &buf[1];
510	for (i = 0; i < nfs_root_node.fhsize; i++, cp += 2)
511		sprintf(cp, "%02x", fh[i]);
512	sprintf(cp, "X");
513	setenv("boot.nfsroot.nfshandle", buf, 1);
514	sprintf(buf, "%d", nfs_root_node.fhsize);
515	setenv("boot.nfsroot.nfshandlelen", buf, 1);
516}
517#endif	/* OLD_NFSV2 */
518
519void
520pxenv_call(int func)
521{
522#ifdef PXE_DEBUG
523	if (pxe_debug)
524		printf("pxenv_call %x\n", func);
525#endif
526
527	bzero(&v86, sizeof(v86));
528	bzero(data_buffer, sizeof(data_buffer));
529
530	__pxenvseg = pxenv_p->RMEntry.segment;
531	__pxenvoff = pxenv_p->RMEntry.offset;
532
533	v86.ctl  = V86_ADDR | V86_CALLF | V86_FLAGS;
534	v86.es   = VTOPSEG(scratch_buffer);
535	v86.edi  = VTOPOFF(scratch_buffer);
536	v86.addr = (VTOPSEG(__pxenventry) << 16) | VTOPOFF(__pxenventry);
537	v86.ebx  = func;
538	v86int();
539	v86.ctl  = V86_FLAGS;
540}
541
542void
543bangpxe_call(int func)
544{
545#ifdef PXE_DEBUG
546	if (pxe_debug)
547		printf("bangpxe_call %x\n", func);
548#endif
549
550	bzero(&v86, sizeof(v86));
551	bzero(data_buffer, sizeof(data_buffer));
552
553	__bangpxeseg = pxe_p->EntryPointSP.segment;
554	__bangpxeoff = pxe_p->EntryPointSP.offset;
555
556	v86.ctl  = V86_ADDR | V86_CALLF | V86_FLAGS;
557	v86.edx  = VTOPSEG(scratch_buffer);
558	v86.eax  = VTOPOFF(scratch_buffer);
559	v86.addr = (VTOPSEG(__bangpxeentry) << 16) | VTOPOFF(__bangpxeentry);
560	v86.ebx  = func;
561	v86int();
562	v86.ctl  = V86_FLAGS;
563}
564
565
566time_t
567getsecs()
568{
569	time_t n = 0;
570	time(&n);
571	return n;
572}
573
574static int
575pxe_netif_match(struct netif *nif, void *machdep_hint)
576{
577	return 1;
578}
579
580
581static int
582pxe_netif_probe(struct netif *nif, void *machdep_hint)
583{
584	t_PXENV_UDP_OPEN *udpopen_p = (t_PXENV_UDP_OPEN *)scratch_buffer;
585
586	if (pxe_call == NULL)
587		return -1;
588
589	bzero(udpopen_p, sizeof(*udpopen_p));
590	udpopen_p->src_ip = bootplayer.yip;
591	pxe_call(PXENV_UDP_OPEN);
592
593	if (udpopen_p->status != 0) {
594		printf("pxe_netif_probe: failed %x\n", udpopen_p->status);
595		return -1;
596	}
597	return 0;
598}
599
600static void
601pxe_netif_end(struct netif *nif)
602{
603	t_PXENV_UDP_CLOSE *udpclose_p = (t_PXENV_UDP_CLOSE *)scratch_buffer;
604	bzero(udpclose_p, sizeof(*udpclose_p));
605
606	pxe_call(PXENV_UDP_CLOSE);
607	if (udpclose_p->status != 0)
608		printf("pxe_end failed %x\n", udpclose_p->status);
609}
610
611static void
612pxe_netif_init(struct iodesc *desc, void *machdep_hint)
613{
614	int i;
615	for (i = 0; i < 6; ++i)
616		desc->myea[i] = bootplayer.CAddr[i];
617	desc->xid = bootplayer.ident;
618}
619
620static int
621pxe_netif_get(struct iodesc *desc, void *pkt, size_t len, time_t timeout)
622{
623	return len;
624}
625
626static int
627pxe_netif_put(struct iodesc *desc, void *pkt, size_t len)
628{
629	return len;
630}
631
632ssize_t
633sendudp(struct iodesc *h, void *pkt, size_t len)
634{
635	t_PXENV_UDP_WRITE *udpwrite_p = (t_PXENV_UDP_WRITE *)scratch_buffer;
636	bzero(udpwrite_p, sizeof(*udpwrite_p));
637
638	udpwrite_p->ip             = h->destip.s_addr;
639	udpwrite_p->dst_port       = h->destport;
640	udpwrite_p->src_port       = h->myport;
641	udpwrite_p->buffer_size    = len;
642	udpwrite_p->buffer.segment = VTOPSEG(pkt);
643	udpwrite_p->buffer.offset  = VTOPOFF(pkt);
644
645	if (netmask == 0 || SAMENET(myip, h->destip, netmask))
646		udpwrite_p->gw = 0;
647	else
648		udpwrite_p->gw = gateip.s_addr;
649
650	pxe_call(PXENV_UDP_WRITE);
651
652#if 0
653	/* XXX - I dont know why we need this. */
654	delay(1000);
655#endif
656	if (udpwrite_p->status != 0) {
657		/* XXX: This happens a lot.  It shouldn't. */
658		if (udpwrite_p->status != 1)
659			printf("sendudp failed %x\n", udpwrite_p->status);
660		return -1;
661	}
662	return len;
663}
664
665ssize_t
666readudp(struct iodesc *h, void *pkt, size_t len, time_t timeout)
667{
668	t_PXENV_UDP_READ *udpread_p = (t_PXENV_UDP_READ *)scratch_buffer;
669	struct udphdr *uh = NULL;
670
671	uh = (struct udphdr *) pkt - 1;
672	bzero(udpread_p, sizeof(*udpread_p));
673
674	udpread_p->dest_ip        = h->myip.s_addr;
675	udpread_p->d_port         = h->myport;
676	udpread_p->buffer_size    = len;
677	udpread_p->buffer.segment = VTOPSEG(data_buffer);
678	udpread_p->buffer.offset  = VTOPOFF(data_buffer);
679
680	pxe_call(PXENV_UDP_READ);
681
682#if 0
683	/* XXX - I dont know why we need this. */
684	delay(1000);
685#endif
686	if (udpread_p->status != 0) {
687		/* XXX: This happens a lot.  It shouldn't. */
688		if (udpread_p->status != 1)
689			printf("readudp failed %x\n", udpread_p->status);
690		return -1;
691	}
692	bcopy(data_buffer, pkt, udpread_p->buffer_size);
693	uh->uh_sport = udpread_p->s_port;
694	return udpread_p->buffer_size;
695}
696