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psbuf.c revision 1.16 
      1 /*      $NetBSD: psbuf.c,v 1.16 2010/01/07 21:05:50 pooka Exp $        */
      2 
      3 /*
      4  * Copyright (c) 2006-2009  Antti Kantee.  All Rights Reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
     16  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     18  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     21  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     25  * SUCH DAMAGE.
     26  */
     27 
     28 #include <sys/cdefs.h>
     29 #ifndef lint
     30 __RCSID("$NetBSD: psbuf.c,v 1.16 2010/01/07 21:05:50 pooka Exp $");
     31 #endif /* !lint */
     32 
     33 /*
     34  * buffering functions for network input/output.  slightly different
     35  * from the average joe buffer routines, as is usually the case ...
     36  * these use efuns for now.
     37  */
     38 
     39 #include <sys/types.h>
     40 #include <sys/time.h>
     41 #include <sys/vnode.h>
     42 
     43 #include <err.h>
     44 #include <errno.h>
     45 #include <stdlib.h>
     46 #include <util.h>
     47 #include <unistd.h>
     48 
     49 #include "psshfs.h"
     50 #include "sftp_proto.h"
     51 
     52 #define FAILRV(x) do { int rv; if ((rv=x)) return (rv); } while (/*CONSTCOND*/0)
     53 #define READSTATE_LENGTH(off) (off < 4)
     54 
     55 #define SFTP_LENOFF	0
     56 #define SFTP_TYPEOFF	4
     57 #define SFTP_REQIDOFF	5
     58 
     59 #define CHECK(v) if (!(v)) abort()
     60 
     61 uint8_t
     62 psbuf_get_type(struct puffs_framebuf *pb)
     63 {
     64 	uint8_t type;
     65 
     66 	puffs_framebuf_getdata_atoff(pb, SFTP_TYPEOFF, &type, 1);
     67 	return type;
     68 }
     69 
     70 uint32_t
     71 psbuf_get_len(struct puffs_framebuf *pb)
     72 {
     73 	uint32_t len;
     74 
     75 	puffs_framebuf_getdata_atoff(pb, SFTP_LENOFF, &len, 4);
     76 	return be32toh(len);
     77 }
     78 
     79 uint32_t
     80 psbuf_get_reqid(struct puffs_framebuf *pb)
     81 {
     82 	uint32_t req;
     83 
     84 	puffs_framebuf_getdata_atoff(pb, SFTP_REQIDOFF, &req, 4);
     85 	return be32toh(req);
     86 }
     87 
     88 #define CUROFF(pb) (puffs_framebuf_telloff(pb))
     89 int
     90 psbuf_read(struct puffs_usermount *pu, struct puffs_framebuf *pb,
     91 	int fd, int *done)
     92 {
     93 	void *win;
     94 	ssize_t n;
     95 	size_t howmuch, winlen;
     96 	int lenstate;
     97 
     98  the_next_level:
     99 	if ((lenstate = READSTATE_LENGTH(CUROFF(pb))))
    100 		howmuch = 4 - CUROFF(pb);
    101 	else
    102 		howmuch = psbuf_get_len(pb) - (CUROFF(pb) - 4);
    103 
    104 	if (puffs_framebuf_reserve_space(pb, howmuch) == -1)
    105 		return errno;
    106 
    107 	while (howmuch) {
    108 		winlen = howmuch;
    109 		if (puffs_framebuf_getwindow(pb, CUROFF(pb), &win, &winlen)==-1)
    110 			return errno;
    111 		n = recv(fd, win, winlen, MSG_NOSIGNAL);
    112 		switch (n) {
    113 		case 0:
    114 			return ECONNRESET;
    115 		case -1:
    116 			if (errno == EAGAIN)
    117 				return 0;
    118 			return errno;
    119 		default:
    120 			howmuch -= n;
    121 			puffs_framebuf_seekset(pb, CUROFF(pb) + n);
    122 			break;
    123 		}
    124 	}
    125 
    126 	if (!lenstate) {
    127 		/* XXX: initial exchange shorter.. but don't worry, be happy */
    128 		puffs_framebuf_seekset(pb, 9);
    129 		*done = 1;
    130 		return 0;
    131 	} else
    132 		goto the_next_level;
    133 }
    134 
    135 int
    136 psbuf_write(struct puffs_usermount *pu, struct puffs_framebuf *pb,
    137 	int fd, int *done)
    138 {
    139 	void *win;
    140 	ssize_t n;
    141 	size_t winlen, howmuch;
    142 
    143 	/* finalize buffer.. could be elsewhere ... */
    144 	if (CUROFF(pb) == 0) {
    145 		uint32_t len;
    146 
    147 		len = htobe32(puffs_framebuf_tellsize(pb) - 4);
    148 		puffs_framebuf_putdata_atoff(pb, 0, &len, 4);
    149 	}
    150 
    151 	howmuch = puffs_framebuf_tellsize(pb) - CUROFF(pb);
    152 	while (howmuch) {
    153 		winlen = howmuch;
    154 		if (puffs_framebuf_getwindow(pb, CUROFF(pb), &win, &winlen)==-1)
    155 			return errno;
    156 		n = send(fd, win, winlen, MSG_NOSIGNAL);
    157 		switch (n) {
    158 		case 0:
    159 			return ECONNRESET;
    160 		case -1:
    161 			if (errno == EAGAIN)
    162 				return 0;
    163 			return errno;
    164 		default:
    165 			howmuch -= n;
    166 			puffs_framebuf_seekset(pb, CUROFF(pb) + n);
    167 			break;
    168 		}
    169 	}
    170 
    171 	*done = 1;
    172 	return 0;
    173 }
    174 #undef CUROFF
    175 
    176 int
    177 psbuf_cmp(struct puffs_usermount *pu,
    178 	struct puffs_framebuf *cmp1, struct puffs_framebuf *cmp2, int *notresp)
    179 {
    180 
    181 	return psbuf_get_reqid(cmp1) != psbuf_get_reqid(cmp2);
    182 }
    183 
    184 struct puffs_framebuf *
    185 psbuf_makeout()
    186 {
    187 	struct puffs_framebuf *pb;
    188 
    189 	pb = puffs_framebuf_make();
    190 	puffs_framebuf_seekset(pb, 4);
    191 	return pb;
    192 }
    193 
    194 void
    195 psbuf_recycleout(struct puffs_framebuf *pb)
    196 {
    197 
    198 	puffs_framebuf_recycle(pb);
    199 	puffs_framebuf_seekset(pb, 4);
    200 }
    201 
    202 void
    203 psbuf_put_1(struct puffs_framebuf *pb, uint8_t val)
    204 {
    205 	int rv;
    206 
    207 	rv = puffs_framebuf_putdata(pb, &val, 1);
    208 	CHECK(rv == 0);
    209 }
    210 
    211 void
    212 psbuf_put_2(struct puffs_framebuf *pb, uint16_t val)
    213 {
    214 	int rv;
    215 
    216 	HTOBE16(val);
    217 	rv = puffs_framebuf_putdata(pb, &val, 2);
    218 	CHECK(rv == 0);
    219 }
    220 
    221 void
    222 psbuf_put_4(struct puffs_framebuf *pb, uint32_t val)
    223 {
    224 	int rv;
    225 
    226 	HTOBE32(val);
    227 	rv = puffs_framebuf_putdata(pb, &val, 4);
    228 	CHECK(rv == 0);
    229 }
    230 
    231 void
    232 psbuf_put_8(struct puffs_framebuf *pb, uint64_t val)
    233 {
    234 	int rv;
    235 
    236 	HTOBE64(val);
    237 	rv = puffs_framebuf_putdata(pb, &val, 8);
    238 	CHECK(rv == 0);
    239 }
    240 
    241 void
    242 psbuf_put_data(struct puffs_framebuf *pb, const void *data, uint32_t dlen)
    243 {
    244 	int rv;
    245 
    246 	psbuf_put_4(pb, dlen);
    247 	rv = puffs_framebuf_putdata(pb, data, dlen);
    248 	CHECK(rv == 0);
    249 }
    250 
    251 void
    252 psbuf_put_str(struct puffs_framebuf *pb, const char *str)
    253 {
    254 
    255 	psbuf_put_data(pb, str, strlen(str));
    256 }
    257 
    258 void
    259 psbuf_put_vattr(struct puffs_framebuf *pb, const struct vattr *va,
    260 	const struct psshfs_ctx *pctx)
    261 {
    262 	uint32_t flags;
    263 	flags = 0;
    264 
    265 	if (va->va_size != (uint64_t)PUFFS_VNOVAL)
    266 		flags |= SSH_FILEXFER_ATTR_SIZE;
    267 	if (va->va_uid != (uid_t)PUFFS_VNOVAL)
    268 		flags |= SSH_FILEXFER_ATTR_UIDGID;
    269 	if (va->va_mode != (mode_t)PUFFS_VNOVAL)
    270 		flags |= SSH_FILEXFER_ATTR_PERMISSIONS;
    271 
    272 	if (va->va_atime.tv_sec != PUFFS_VNOVAL)
    273 		flags |= SSH_FILEXFER_ATTR_ACCESSTIME;
    274 
    275 	psbuf_put_4(pb, flags);
    276 	if (flags & SSH_FILEXFER_ATTR_SIZE)
    277 		psbuf_put_8(pb, va->va_size);
    278 	if (flags & SSH_FILEXFER_ATTR_UIDGID) {
    279 		uid_t theuid;
    280 		gid_t thegid;
    281 
    282 		theuid = va->va_uid;
    283 		if (pctx->domangleuid && theuid == pctx->myuid)
    284 			theuid = pctx->mangleuid;
    285 		thegid = va->va_gid;
    286 		if (pctx->domanglegid && thegid == pctx->mygid)
    287 			thegid = pctx->manglegid;
    288 
    289 		psbuf_put_4(pb, theuid);
    290 		psbuf_put_4(pb, thegid);
    291 	}
    292 	if (flags & SSH_FILEXFER_ATTR_PERMISSIONS)
    293 		psbuf_put_4(pb, va->va_mode);
    294 
    295 	/* XXX: this is totally wrong for protocol v3, see OpenSSH */
    296 	if (flags & SSH_FILEXFER_ATTR_ACCESSTIME) {
    297 		psbuf_put_4(pb, va->va_atime.tv_sec);
    298 		psbuf_put_4(pb, va->va_mtime.tv_sec);
    299 	}
    300 }
    301 
    302 #define ERETURN(rv) return ((rv) == -1 ? errno : 0)
    303 
    304 int
    305 psbuf_get_1(struct puffs_framebuf *pb, uint8_t *val)
    306 {
    307 
    308 	ERETURN(puffs_framebuf_getdata(pb, val, 1));
    309 }
    310 
    311 int
    312 psbuf_get_2(struct puffs_framebuf *pb, uint16_t *val)
    313 {
    314 	int rv;
    315 
    316 	rv = puffs_framebuf_getdata(pb, val, 2);
    317 	BE16TOH(*val);
    318 
    319 	ERETURN(rv);
    320 }
    321 
    322 int
    323 psbuf_get_4(struct puffs_framebuf *pb, uint32_t *val)
    324 {
    325 	int rv;
    326 
    327 	rv = puffs_framebuf_getdata(pb, val, 4);
    328 	BE32TOH(*val);
    329 
    330 	ERETURN(rv);
    331 }
    332 
    333 int
    334 psbuf_get_8(struct puffs_framebuf *pb, uint64_t *val)
    335 {
    336 	int rv;
    337 
    338 	rv = puffs_framebuf_getdata(pb, val, 8);
    339 	BE64TOH(*val);
    340 
    341 	ERETURN(rv);
    342 }
    343 
    344 int
    345 psbuf_get_str(struct puffs_framebuf *pb, char **strp, uint32_t *strlenp)
    346 {
    347 	char *str;
    348 	uint32_t len;
    349 
    350 	FAILRV(psbuf_get_4(pb, &len));
    351 
    352 	if (puffs_framebuf_remaining(pb) < len)
    353 		return EPROTO;
    354 
    355 	str = emalloc(len+1);
    356 	puffs_framebuf_getdata(pb, str, len);
    357 	str[len] = '\0';
    358 	*strp = str;
    359 
    360 	if (strlenp)
    361 		*strlenp = len;
    362 
    363 	return 0;
    364 }
    365 
    366 int
    367 psbuf_get_vattr(struct puffs_framebuf *pb, struct vattr *vap)
    368 {
    369 	uint32_t flags;
    370 	uint32_t val;
    371 
    372 	puffs_vattr_null(vap);
    373 
    374 	FAILRV(psbuf_get_4(pb, &flags));
    375 
    376 	if (flags & SSH_FILEXFER_ATTR_SIZE) {
    377 		FAILRV(psbuf_get_8(pb, &vap->va_size));
    378 		vap->va_bytes = vap->va_size;
    379 	}
    380 	if (flags & SSH_FILEXFER_ATTR_UIDGID) {
    381 		FAILRV(psbuf_get_4(pb, &vap->va_uid));
    382 		FAILRV(psbuf_get_4(pb, &vap->va_gid));
    383 	}
    384 	if (flags & SSH_FILEXFER_ATTR_PERMISSIONS) {
    385 		FAILRV(psbuf_get_4(pb, &vap->va_mode));
    386 		vap->va_type = puffs_mode2vt(vap->va_mode);
    387 	}
    388 	if (flags & SSH_FILEXFER_ATTR_ACCESSTIME) {
    389 		/*
    390 		 * XXX: this is utterly wrong if we want to speak
    391 		 * protocol version 3, but it seems like the
    392 		 * "internet standard" for doing this
    393 		 */
    394 		FAILRV(psbuf_get_4(pb, &val));
    395 		vap->va_atime.tv_sec = val;
    396 		FAILRV(psbuf_get_4(pb, &val));
    397 		vap->va_mtime.tv_sec = val;
    398 		/* make ctime the same as mtime */
    399 		vap->va_ctime.tv_sec = val;
    400 
    401 		vap->va_atime.tv_nsec = 0;
    402 		vap->va_ctime.tv_nsec = 0;
    403 		vap->va_mtime.tv_nsec = 0;
    404 	}
    405 
    406 	return 0;
    407 }
    408 
    409 /*
    410  * Buffer content helpers.  Caller frees all data.
    411  */
    412 
    413 /*
    414  * error mapping.. most are not expected for a file system, but
    415  * should help with diagnosing a possible error
    416  */
    417 static int emap[] = {
    418 	0,			/* OK			*/
    419 	0,			/* EOF			*/
    420 	ENOENT,			/* NO_SUCH_FILE		*/
    421 	EPERM,			/* PERMISSION_DENIED	*/
    422 	EIO,			/* FAILURE		*/
    423 	EBADMSG,		/* BAD_MESSAGE		*/
    424 	ENOTCONN,		/* NO_CONNECTION	*/
    425 	ECONNRESET,		/* CONNECTION_LOST	*/
    426 	EOPNOTSUPP,		/* OP_UNSUPPORTED	*/
    427 	EINVAL,			/* INVALID_HANDLE	*/
    428 	ENXIO,			/* NO_SUCH_PATH		*/
    429 	EEXIST,			/* FILE_ALREADY_EXISTS	*/
    430 	ENODEV			/* WRITE_PROTECT	*/
    431 };
    432 #define NERRORS ((int)(sizeof(emap) / sizeof(emap[0])))
    433 
    434 static int
    435 sftperr_to_errno(int error)
    436 {
    437 
    438 	if (!error)
    439 		return 0;
    440 
    441 	if (error >= NERRORS || error < 0)
    442 		return EPROTO;
    443 
    444 	return emap[error];
    445 }
    446 
    447 #define INVALRESPONSE EPROTO
    448 
    449 static int
    450 expectcode(struct puffs_framebuf *pb, int value)
    451 {
    452 	uint32_t error;
    453 	uint8_t type;
    454 
    455 	type = psbuf_get_type(pb);
    456 	if (type == value)
    457 		return 0;
    458 
    459 	if (type != SSH_FXP_STATUS)
    460 		return INVALRESPONSE;
    461 
    462 	FAILRV(psbuf_get_4(pb, &error));
    463 
    464 	return sftperr_to_errno(error);
    465 }
    466 
    467 #define CHECKCODE(pb,val)						\
    468 do {									\
    469 	int rv;								\
    470 	rv = expectcode(pb, val);					\
    471 	if (rv)								\
    472 		return rv;						\
    473 } while (/*CONSTCOND*/0)
    474 
    475 int
    476 psbuf_expect_status(struct puffs_framebuf *pb)
    477 {
    478 	uint32_t error;
    479 
    480 	if (psbuf_get_type(pb) != SSH_FXP_STATUS)
    481 		return INVALRESPONSE;
    482 
    483 	FAILRV(psbuf_get_4(pb, &error));
    484 
    485 	return sftperr_to_errno(error);
    486 }
    487 
    488 int
    489 psbuf_expect_handle(struct puffs_framebuf *pb, char **hand, uint32_t *handlen)
    490 {
    491 
    492 	CHECKCODE(pb, SSH_FXP_HANDLE);
    493 	FAILRV(psbuf_get_str(pb, hand, handlen));
    494 
    495 	return 0;
    496 }
    497 
    498 /* no memory allocation, direct copy */
    499 int
    500 psbuf_do_data(struct puffs_framebuf *pb, uint8_t *data, uint32_t *dlen)
    501 {
    502 	void *win;
    503 	size_t bufoff, winlen;
    504 	uint32_t len, dataoff;
    505 
    506 	if (psbuf_get_type(pb) != SSH_FXP_DATA) {
    507 		uint32_t val;
    508 
    509 		if (psbuf_get_type(pb) != SSH_FXP_STATUS)
    510 			return INVALRESPONSE;
    511 
    512 		if (psbuf_get_4(pb, &val) != 0)
    513 			return INVALRESPONSE;
    514 
    515 		if (val != SSH_FX_EOF)
    516 			return sftperr_to_errno(val);
    517 
    518 		*dlen = 0;
    519 		return 0;
    520 	}
    521 	if (psbuf_get_4(pb, &len) != 0)
    522 		return INVALRESPONSE;
    523 
    524 	if (*dlen < len)
    525 		return EINVAL;
    526 
    527 	*dlen = 0;
    528 
    529 	dataoff = 0;
    530 	while (dataoff < len) {
    531 		winlen = len-dataoff;
    532 		bufoff = puffs_framebuf_telloff(pb);
    533 		if (puffs_framebuf_getwindow(pb, bufoff,
    534 		    &win, &winlen) == -1)
    535 			return EINVAL;
    536 		if (winlen == 0)
    537 			break;
    538 
    539 		memcpy(data + dataoff, win, winlen);
    540 		dataoff += winlen;
    541 	}
    542 
    543 	*dlen = dataoff;
    544 
    545 	return 0;
    546 }
    547 
    548 int
    549 psbuf_expect_name(struct puffs_framebuf *pb, uint32_t *count)
    550 {
    551 
    552 	CHECKCODE(pb, SSH_FXP_NAME);
    553 	FAILRV(psbuf_get_4(pb, count));
    554 
    555 	return 0;
    556 }
    557 
    558 int
    559 psbuf_expect_attrs(struct puffs_framebuf *pb, struct vattr *vap)
    560 {
    561 
    562 	CHECKCODE(pb, SSH_FXP_ATTRS);
    563 	FAILRV(psbuf_get_vattr(pb, vap));
    564 
    565 	return 0;
    566 }
    567 
    568 /*
    569  * More helpers: larger-scale put functions
    570  */
    571 
    572 void
    573 psbuf_req_data(struct puffs_framebuf *pb, int type, uint32_t reqid,
    574 	const void *data, uint32_t dlen)
    575 {
    576 
    577 	psbuf_put_1(pb, type);
    578 	psbuf_put_4(pb, reqid);
    579 	psbuf_put_data(pb, data, dlen);
    580 }
    581 
    582 void
    583 psbuf_req_str(struct puffs_framebuf *pb, int type, uint32_t reqid,
    584 	const char *str)
    585 {
    586 
    587 	psbuf_req_data(pb, type, reqid, str, strlen(str));
    588 }
    589