2 * sftp.c: SFTP generic client code.
13 #define smalloc malloc
14 #define srealloc realloc
17 #define GET_32BIT(cp) \
18 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
19 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
20 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
21 ((unsigned long)(unsigned char)(cp)[3]))
23 #define PUT_32BIT(cp, value) { \
24 (cp)[0] = (unsigned char)((value) >> 24); \
25 (cp)[1] = (unsigned char)((value) >> 16); \
26 (cp)[2] = (unsigned char)((value) >> 8); \
27 (cp)[3] = (unsigned char)(value); }
36 static const char *fxp_error_message
;
37 static int fxp_errtype
;
39 /* ----------------------------------------------------------------------
40 * SFTP packet construction functions.
42 static void sftp_pkt_ensure(struct sftp_packet
*pkt
, int length
)
44 if (pkt
->maxlen
< length
) {
45 pkt
->maxlen
= length
+ 256;
46 pkt
->data
= srealloc(pkt
->data
, pkt
->maxlen
);
49 static void sftp_pkt_adddata(struct sftp_packet
*pkt
, void *data
, int len
)
52 sftp_pkt_ensure(pkt
, pkt
->length
);
53 memcpy(pkt
->data
+ pkt
->length
- len
, data
, len
);
55 static void sftp_pkt_addbyte(struct sftp_packet
*pkt
, unsigned char byte
)
57 sftp_pkt_adddata(pkt
, &byte
, 1);
59 static struct sftp_packet
*sftp_pkt_init(int pkt_type
)
61 struct sftp_packet
*pkt
;
62 pkt
= smalloc(sizeof(struct sftp_packet
));
67 sftp_pkt_addbyte(pkt
, (unsigned char) pkt_type
);
68 fxp_error_message
= NULL
;
71 static void sftp_pkt_addbool(struct sftp_packet
*pkt
, unsigned char value
)
73 sftp_pkt_adddata(pkt
, &value
, 1);
75 static void sftp_pkt_adduint32(struct sftp_packet
*pkt
,
80 sftp_pkt_adddata(pkt
, x
, 4);
82 static void sftp_pkt_adduint64(struct sftp_packet
*pkt
, uint64 value
)
85 PUT_32BIT(x
, value
.hi
);
86 PUT_32BIT(x
+ 4, value
.lo
);
87 sftp_pkt_adddata(pkt
, x
, 8);
89 static void sftp_pkt_addstring_start(struct sftp_packet
*pkt
)
91 sftp_pkt_adduint32(pkt
, 0);
92 pkt
->savedpos
= pkt
->length
;
94 static void sftp_pkt_addstring_str(struct sftp_packet
*pkt
, char *data
)
96 sftp_pkt_adddata(pkt
, data
, strlen(data
));
97 PUT_32BIT(pkt
->data
+ pkt
->savedpos
- 4, pkt
->length
- pkt
->savedpos
);
99 static void sftp_pkt_addstring_data(struct sftp_packet
*pkt
,
102 sftp_pkt_adddata(pkt
, data
, len
);
103 PUT_32BIT(pkt
->data
+ pkt
->savedpos
- 4, pkt
->length
- pkt
->savedpos
);
105 static void sftp_pkt_addstring(struct sftp_packet
*pkt
, char *data
)
107 sftp_pkt_addstring_start(pkt
);
108 sftp_pkt_addstring_str(pkt
, data
);
110 static void sftp_pkt_addattrs(struct sftp_packet
*pkt
, struct fxp_attrs attrs
)
112 sftp_pkt_adduint32(pkt
, attrs
.flags
);
113 if (attrs
.flags
& SSH_FILEXFER_ATTR_SIZE
) {
114 sftp_pkt_adduint32(pkt
, attrs
.size
.hi
);
115 sftp_pkt_adduint32(pkt
, attrs
.size
.lo
);
117 if (attrs
.flags
& SSH_FILEXFER_ATTR_UIDGID
) {
118 sftp_pkt_adduint32(pkt
, attrs
.uid
);
119 sftp_pkt_adduint32(pkt
, attrs
.gid
);
121 if (attrs
.flags
& SSH_FILEXFER_ATTR_PERMISSIONS
) {
122 sftp_pkt_adduint32(pkt
, attrs
.permissions
);
124 if (attrs
.flags
& SSH_FILEXFER_ATTR_ACMODTIME
) {
125 sftp_pkt_adduint32(pkt
, attrs
.atime
);
126 sftp_pkt_adduint32(pkt
, attrs
.mtime
);
128 if (attrs
.flags
& SSH_FILEXFER_ATTR_EXTENDED
) {
130 * We currently don't support sending any extended
136 /* ----------------------------------------------------------------------
137 * SFTP packet decode functions.
140 static unsigned char sftp_pkt_getbyte(struct sftp_packet
*pkt
)
143 if (pkt
->length
- pkt
->savedpos
< 1)
144 return 0; /* arrgh, no way to decline (FIXME?) */
145 value
= (unsigned char) pkt
->data
[pkt
->savedpos
];
149 static unsigned long sftp_pkt_getuint32(struct sftp_packet
*pkt
)
152 if (pkt
->length
- pkt
->savedpos
< 4)
153 return 0; /* arrgh, no way to decline (FIXME?) */
154 value
= GET_32BIT(pkt
->data
+ pkt
->savedpos
);
158 static void sftp_pkt_getstring(struct sftp_packet
*pkt
,
159 char **p
, int *length
)
162 if (pkt
->length
- pkt
->savedpos
< 4)
164 *length
= GET_32BIT(pkt
->data
+ pkt
->savedpos
);
166 if (pkt
->length
- pkt
->savedpos
< *length
)
168 *p
= pkt
->data
+ pkt
->savedpos
;
169 pkt
->savedpos
+= *length
;
171 static struct fxp_attrs
sftp_pkt_getattrs(struct sftp_packet
*pkt
)
173 struct fxp_attrs ret
;
174 ret
.flags
= sftp_pkt_getuint32(pkt
);
175 if (ret
.flags
& SSH_FILEXFER_ATTR_SIZE
) {
176 unsigned long hi
, lo
;
177 hi
= sftp_pkt_getuint32(pkt
);
178 lo
= sftp_pkt_getuint32(pkt
);
179 ret
.size
= uint64_make(hi
, lo
);
181 if (ret
.flags
& SSH_FILEXFER_ATTR_UIDGID
) {
182 ret
.uid
= sftp_pkt_getuint32(pkt
);
183 ret
.gid
= sftp_pkt_getuint32(pkt
);
185 if (ret
.flags
& SSH_FILEXFER_ATTR_PERMISSIONS
) {
186 ret
.permissions
= sftp_pkt_getuint32(pkt
);
188 if (ret
.flags
& SSH_FILEXFER_ATTR_ACMODTIME
) {
189 ret
.atime
= sftp_pkt_getuint32(pkt
);
190 ret
.mtime
= sftp_pkt_getuint32(pkt
);
192 if (ret
.flags
& SSH_FILEXFER_ATTR_EXTENDED
) {
194 count
= sftp_pkt_getuint32(pkt
);
199 * We should try to analyse these, if we ever find one
202 sftp_pkt_getstring(pkt
, &str
, &len
);
203 sftp_pkt_getstring(pkt
, &str
, &len
);
208 static void sftp_pkt_free(struct sftp_packet
*pkt
)
215 /* ----------------------------------------------------------------------
216 * Send and receive packet functions.
218 int sftp_send(struct sftp_packet
*pkt
)
222 PUT_32BIT(x
, pkt
->length
);
223 ret
= (sftp_senddata(x
, 4) && sftp_senddata(pkt
->data
, pkt
->length
));
227 struct sftp_packet
*sftp_recv(void)
229 struct sftp_packet
*pkt
;
232 if (!sftp_recvdata(x
, 4))
235 pkt
= smalloc(sizeof(struct sftp_packet
));
237 pkt
->length
= pkt
->maxlen
= GET_32BIT(x
);
238 pkt
->data
= smalloc(pkt
->length
);
240 if (!sftp_recvdata(pkt
->data
, pkt
->length
)) {
245 pkt
->type
= sftp_pkt_getbyte(pkt
);
250 /* ----------------------------------------------------------------------
251 * String handling routines.
254 static char *mkstr(char *s
, int len
)
256 char *p
= smalloc(len
+ 1);
262 /* ----------------------------------------------------------------------
267 * Deal with (and free) an FXP_STATUS packet. Return 1 if
268 * SSH_FX_OK, 0 if SSH_FX_EOF, and -1 for anything else (error).
269 * Also place the status into fxp_errtype.
271 static int fxp_got_status(struct sftp_packet
*pktin
)
273 static const char *const messages
[] = {
274 /* SSH_FX_OK. The only time we will display a _message_ for this
275 * is if we were expecting something other than FXP_STATUS on
276 * success, so this is actually an error message! */
277 "unexpected OK response",
279 "no such file or directory",
285 "operation unsupported",
288 if (pktin
->type
!= SSH_FXP_STATUS
) {
289 fxp_error_message
= "expected FXP_STATUS packet";
292 fxp_errtype
= sftp_pkt_getuint32(pktin
);
293 if (fxp_errtype
< 0 ||
294 fxp_errtype
>= sizeof(messages
) / sizeof(*messages
))
295 fxp_error_message
= "unknown error code";
297 fxp_error_message
= messages
[fxp_errtype
];
300 if (fxp_errtype
== SSH_FX_OK
)
302 else if (fxp_errtype
== SSH_FX_EOF
)
308 static void fxp_internal_error(char *msg
)
310 fxp_error_message
= msg
;
314 const char *fxp_error(void)
316 return fxp_error_message
;
319 int fxp_error_type(void)
325 * Perform exchange of init/version packets. Return 0 on failure.
329 struct sftp_packet
*pktout
, *pktin
;
332 pktout
= sftp_pkt_init(SSH_FXP_INIT
);
333 sftp_pkt_adduint32(pktout
, SFTP_PROTO_VERSION
);
338 fxp_internal_error("could not connect");
341 if (pktin
->type
!= SSH_FXP_VERSION
) {
342 fxp_internal_error("did not receive FXP_VERSION");
345 remotever
= sftp_pkt_getuint32(pktin
);
346 if (remotever
> SFTP_PROTO_VERSION
) {
348 ("remote protocol is more advanced than we support");
352 * In principle, this packet might also contain extension-
353 * string pairs. We should work through them and look for any
354 * we recognise. In practice we don't currently do so because
355 * we know we don't recognise _any_.
357 sftp_pkt_free(pktin
);
363 * Canonify a pathname.
365 char *fxp_realpath(char *path
)
367 struct sftp_packet
*pktin
, *pktout
;
370 pktout
= sftp_pkt_init(SSH_FXP_REALPATH
);
371 sftp_pkt_adduint32(pktout
, 0x123); /* request id */
372 sftp_pkt_addstring_start(pktout
);
373 sftp_pkt_addstring_str(pktout
, path
);
376 id
= sftp_pkt_getuint32(pktin
);
378 fxp_internal_error("request ID mismatch\n");
381 if (pktin
->type
== SSH_FXP_NAME
) {
386 count
= sftp_pkt_getuint32(pktin
);
388 fxp_internal_error("REALPATH returned name count != 1\n");
391 sftp_pkt_getstring(pktin
, &path
, &len
);
393 fxp_internal_error("REALPATH returned malformed FXP_NAME\n");
396 path
= mkstr(path
, len
);
397 sftp_pkt_free(pktin
);
400 fxp_got_status(pktin
);
408 struct fxp_handle
*fxp_open(char *path
, int type
)
410 struct sftp_packet
*pktin
, *pktout
;
413 pktout
= sftp_pkt_init(SSH_FXP_OPEN
);
414 sftp_pkt_adduint32(pktout
, 0x567); /* request id */
415 sftp_pkt_addstring(pktout
, path
);
416 sftp_pkt_adduint32(pktout
, type
);
417 sftp_pkt_adduint32(pktout
, 0); /* (FIXME) empty ATTRS structure */
420 id
= sftp_pkt_getuint32(pktin
);
422 fxp_internal_error("request ID mismatch\n");
425 if (pktin
->type
== SSH_FXP_HANDLE
) {
427 struct fxp_handle
*handle
;
430 sftp_pkt_getstring(pktin
, &hstring
, &len
);
432 fxp_internal_error("OPEN returned malformed FXP_HANDLE\n");
435 handle
= smalloc(sizeof(struct fxp_handle
));
436 handle
->hstring
= mkstr(hstring
, len
);
438 sftp_pkt_free(pktin
);
441 fxp_got_status(pktin
);
449 struct fxp_handle
*fxp_opendir(char *path
)
451 struct sftp_packet
*pktin
, *pktout
;
454 pktout
= sftp_pkt_init(SSH_FXP_OPENDIR
);
455 sftp_pkt_adduint32(pktout
, 0x456); /* request id */
456 sftp_pkt_addstring(pktout
, path
);
459 id
= sftp_pkt_getuint32(pktin
);
461 fxp_internal_error("request ID mismatch\n");
464 if (pktin
->type
== SSH_FXP_HANDLE
) {
466 struct fxp_handle
*handle
;
469 sftp_pkt_getstring(pktin
, &hstring
, &len
);
471 fxp_internal_error("OPENDIR returned malformed FXP_HANDLE\n");
474 handle
= smalloc(sizeof(struct fxp_handle
));
475 handle
->hstring
= mkstr(hstring
, len
);
477 sftp_pkt_free(pktin
);
480 fxp_got_status(pktin
);
488 void fxp_close(struct fxp_handle
*handle
)
490 struct sftp_packet
*pktin
, *pktout
;
493 pktout
= sftp_pkt_init(SSH_FXP_CLOSE
);
494 sftp_pkt_adduint32(pktout
, 0x789); /* request id */
495 sftp_pkt_addstring_start(pktout
);
496 sftp_pkt_addstring_data(pktout
, handle
->hstring
, handle
->hlen
);
499 id
= sftp_pkt_getuint32(pktin
);
501 fxp_internal_error("request ID mismatch\n");
504 fxp_got_status(pktin
);
505 sfree(handle
->hstring
);
509 int fxp_mkdir(char *path
)
511 struct sftp_packet
*pktin
, *pktout
;
514 pktout
= sftp_pkt_init(SSH_FXP_MKDIR
);
515 sftp_pkt_adduint32(pktout
, 0x234); /* request id */
516 sftp_pkt_addstring(pktout
, path
);
517 sftp_pkt_adduint32(pktout
, 0); /* (FIXME) empty ATTRS structure */
520 id
= sftp_pkt_getuint32(pktin
);
522 fxp_internal_error("request ID mismatch\n");
525 id
= fxp_got_status(pktin
);
532 int fxp_rmdir(char *path
)
534 struct sftp_packet
*pktin
, *pktout
;
537 pktout
= sftp_pkt_init(SSH_FXP_RMDIR
);
538 sftp_pkt_adduint32(pktout
, 0x345); /* request id */
539 sftp_pkt_addstring(pktout
, path
);
542 id
= sftp_pkt_getuint32(pktin
);
544 fxp_internal_error("request ID mismatch\n");
547 id
= fxp_got_status(pktin
);
554 int fxp_remove(char *fname
)
556 struct sftp_packet
*pktin
, *pktout
;
559 pktout
= sftp_pkt_init(SSH_FXP_REMOVE
);
560 sftp_pkt_adduint32(pktout
, 0x678); /* request id */
561 sftp_pkt_addstring(pktout
, fname
);
564 id
= sftp_pkt_getuint32(pktin
);
566 fxp_internal_error("request ID mismatch\n");
569 id
= fxp_got_status(pktin
);
576 int fxp_rename(char *srcfname
, char *dstfname
)
578 struct sftp_packet
*pktin
, *pktout
;
581 pktout
= sftp_pkt_init(SSH_FXP_RENAME
);
582 sftp_pkt_adduint32(pktout
, 0x678); /* request id */
583 sftp_pkt_addstring(pktout
, srcfname
);
584 sftp_pkt_addstring(pktout
, dstfname
);
587 id
= sftp_pkt_getuint32(pktin
);
589 fxp_internal_error("request ID mismatch\n");
592 id
= fxp_got_status(pktin
);
600 * Retrieve the attributes of a file. We have fxp_stat which works
601 * on filenames, and fxp_fstat which works on open file handles.
603 int fxp_stat(char *fname
, struct fxp_attrs
*attrs
)
605 struct sftp_packet
*pktin
, *pktout
;
608 pktout
= sftp_pkt_init(SSH_FXP_STAT
);
609 sftp_pkt_adduint32(pktout
, 0x678); /* request id */
610 sftp_pkt_addstring(pktout
, fname
);
613 id
= sftp_pkt_getuint32(pktin
);
615 fxp_internal_error("request ID mismatch\n");
619 if (pktin
->type
== SSH_FXP_ATTRS
) {
620 *attrs
= sftp_pkt_getattrs(pktin
);
623 fxp_got_status(pktin
);
628 int fxp_fstat(struct fxp_handle
*handle
, struct fxp_attrs
*attrs
)
630 struct sftp_packet
*pktin
, *pktout
;
633 pktout
= sftp_pkt_init(SSH_FXP_FSTAT
);
634 sftp_pkt_adduint32(pktout
, 0x678); /* request id */
635 sftp_pkt_addstring_start(pktout
);
636 sftp_pkt_addstring_data(pktout
, handle
->hstring
, handle
->hlen
);
639 id
= sftp_pkt_getuint32(pktin
);
641 fxp_internal_error("request ID mismatch\n");
645 if (pktin
->type
== SSH_FXP_ATTRS
) {
646 *attrs
= sftp_pkt_getattrs(pktin
);
649 fxp_got_status(pktin
);
655 * Set the attributes of a file.
657 int fxp_setstat(char *fname
, struct fxp_attrs attrs
)
659 struct sftp_packet
*pktin
, *pktout
;
662 pktout
= sftp_pkt_init(SSH_FXP_SETSTAT
);
663 sftp_pkt_adduint32(pktout
, 0x678); /* request id */
664 sftp_pkt_addstring(pktout
, fname
);
665 sftp_pkt_addattrs(pktout
, attrs
);
668 id
= sftp_pkt_getuint32(pktin
);
670 fxp_internal_error("request ID mismatch\n");
673 id
= fxp_got_status(pktin
);
679 int fxp_fsetstat(struct fxp_handle
*handle
, struct fxp_attrs attrs
)
681 struct sftp_packet
*pktin
, *pktout
;
684 pktout
= sftp_pkt_init(SSH_FXP_FSETSTAT
);
685 sftp_pkt_adduint32(pktout
, 0x678); /* request id */
686 sftp_pkt_addstring_start(pktout
);
687 sftp_pkt_addstring_data(pktout
, handle
->hstring
, handle
->hlen
);
688 sftp_pkt_addattrs(pktout
, attrs
);
691 id
= sftp_pkt_getuint32(pktin
);
693 fxp_internal_error("request ID mismatch\n");
696 id
= fxp_got_status(pktin
);
704 * Read from a file. Returns the number of bytes read, or -1 on an
705 * error, or possibly 0 if EOF. (I'm not entirely sure whether it
706 * will return 0 on EOF, or return -1 and store SSH_FX_EOF in the
707 * error indicator. It might even depend on the SFTP server.)
709 int fxp_read(struct fxp_handle
*handle
, char *buffer
, uint64 offset
,
712 struct sftp_packet
*pktin
, *pktout
;
715 pktout
= sftp_pkt_init(SSH_FXP_READ
);
716 sftp_pkt_adduint32(pktout
, 0xBCD); /* request id */
717 sftp_pkt_addstring_start(pktout
);
718 sftp_pkt_addstring_data(pktout
, handle
->hstring
, handle
->hlen
);
719 sftp_pkt_adduint64(pktout
, offset
);
720 sftp_pkt_adduint32(pktout
, len
);
723 id
= sftp_pkt_getuint32(pktin
);
725 fxp_internal_error("request ID mismatch");
728 if (pktin
->type
== SSH_FXP_DATA
) {
732 sftp_pkt_getstring(pktin
, &str
, &rlen
);
734 if (rlen
> len
|| rlen
< 0) {
735 fxp_internal_error("READ returned more bytes than requested");
739 memcpy(buffer
, str
, rlen
);
743 fxp_got_status(pktin
);
749 * Read from a directory.
751 struct fxp_names
*fxp_readdir(struct fxp_handle
*handle
)
753 struct sftp_packet
*pktin
, *pktout
;
756 pktout
= sftp_pkt_init(SSH_FXP_READDIR
);
757 sftp_pkt_adduint32(pktout
, 0xABC); /* request id */
758 sftp_pkt_addstring_start(pktout
);
759 sftp_pkt_addstring_data(pktout
, handle
->hstring
, handle
->hlen
);
762 id
= sftp_pkt_getuint32(pktin
);
764 fxp_internal_error("request ID mismatch\n");
767 if (pktin
->type
== SSH_FXP_NAME
) {
768 struct fxp_names
*ret
;
770 ret
= smalloc(sizeof(struct fxp_names
));
771 ret
->nnames
= sftp_pkt_getuint32(pktin
);
772 ret
->names
= smalloc(ret
->nnames
* sizeof(struct fxp_name
));
773 for (i
= 0; i
< ret
->nnames
; i
++) {
776 sftp_pkt_getstring(pktin
, &str
, &len
);
777 ret
->names
[i
].filename
= mkstr(str
, len
);
778 sftp_pkt_getstring(pktin
, &str
, &len
);
779 ret
->names
[i
].longname
= mkstr(str
, len
);
780 ret
->names
[i
].attrs
= sftp_pkt_getattrs(pktin
);
784 fxp_got_status(pktin
);
790 * Write to a file. Returns 0 on error, 1 on OK.
792 int fxp_write(struct fxp_handle
*handle
, char *buffer
, uint64 offset
,
795 struct sftp_packet
*pktin
, *pktout
;
798 pktout
= sftp_pkt_init(SSH_FXP_WRITE
);
799 sftp_pkt_adduint32(pktout
, 0xDCB); /* request id */
800 sftp_pkt_addstring_start(pktout
);
801 sftp_pkt_addstring_data(pktout
, handle
->hstring
, handle
->hlen
);
802 sftp_pkt_adduint64(pktout
, offset
);
803 sftp_pkt_addstring_start(pktout
);
804 sftp_pkt_addstring_data(pktout
, buffer
, len
);
807 id
= sftp_pkt_getuint32(pktin
);
809 fxp_internal_error("request ID mismatch\n");
812 fxp_got_status(pktin
);
813 return fxp_errtype
== SSH_FX_OK
;
817 * Free up an fxp_names structure.
819 void fxp_free_names(struct fxp_names
*names
)
823 for (i
= 0; i
< names
->nnames
; i
++) {
824 sfree(names
->names
[i
].filename
);
825 sfree(names
->names
[i
].longname
);