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
);
111 /* ----------------------------------------------------------------------
112 * SFTP packet decode functions.
115 static unsigned char sftp_pkt_getbyte(struct sftp_packet
*pkt
)
118 if (pkt
->length
- pkt
->savedpos
< 1)
119 return 0; /* arrgh, no way to decline (FIXME?) */
120 value
= (unsigned char) pkt
->data
[pkt
->savedpos
];
124 static unsigned long sftp_pkt_getuint32(struct sftp_packet
*pkt
)
127 if (pkt
->length
- pkt
->savedpos
< 4)
128 return 0; /* arrgh, no way to decline (FIXME?) */
129 value
= GET_32BIT(pkt
->data
+ pkt
->savedpos
);
133 static void sftp_pkt_getstring(struct sftp_packet
*pkt
,
134 char **p
, int *length
)
137 if (pkt
->length
- pkt
->savedpos
< 4)
139 *length
= GET_32BIT(pkt
->data
+ pkt
->savedpos
);
141 if (pkt
->length
- pkt
->savedpos
< *length
)
143 *p
= pkt
->data
+ pkt
->savedpos
;
144 pkt
->savedpos
+= *length
;
146 static struct fxp_attrs
sftp_pkt_getattrs(struct sftp_packet
*pkt
)
148 struct fxp_attrs ret
;
149 ret
.flags
= sftp_pkt_getuint32(pkt
);
150 if (ret
.flags
& SSH_FILEXFER_ATTR_SIZE
) {
151 unsigned long hi
, lo
;
152 hi
= sftp_pkt_getuint32(pkt
);
153 lo
= sftp_pkt_getuint32(pkt
);
154 ret
.size
= uint64_make(hi
, lo
);
156 if (ret
.flags
& SSH_FILEXFER_ATTR_UIDGID
) {
157 ret
.uid
= sftp_pkt_getuint32(pkt
);
158 ret
.gid
= sftp_pkt_getuint32(pkt
);
160 if (ret
.flags
& SSH_FILEXFER_ATTR_PERMISSIONS
) {
161 ret
.permissions
= sftp_pkt_getuint32(pkt
);
163 if (ret
.flags
& SSH_FILEXFER_ATTR_ACMODTIME
) {
164 ret
.atime
= sftp_pkt_getuint32(pkt
);
165 ret
.mtime
= sftp_pkt_getuint32(pkt
);
167 if (ret
.flags
& SSH_FILEXFER_ATTR_EXTENDED
) {
169 count
= sftp_pkt_getuint32(pkt
);
174 * We should try to analyse these, if we ever find one
177 sftp_pkt_getstring(pkt
, &str
, &len
);
178 sftp_pkt_getstring(pkt
, &str
, &len
);
183 static void sftp_pkt_free(struct sftp_packet
*pkt
)
190 /* ----------------------------------------------------------------------
191 * Send and receive packet functions.
193 int sftp_send(struct sftp_packet
*pkt
)
197 PUT_32BIT(x
, pkt
->length
);
198 ret
= (sftp_senddata(x
, 4) && sftp_senddata(pkt
->data
, pkt
->length
));
202 struct sftp_packet
*sftp_recv(void)
204 struct sftp_packet
*pkt
;
207 if (!sftp_recvdata(x
, 4))
210 pkt
= smalloc(sizeof(struct sftp_packet
));
212 pkt
->length
= pkt
->maxlen
= GET_32BIT(x
);
213 pkt
->data
= smalloc(pkt
->length
);
215 if (!sftp_recvdata(pkt
->data
, pkt
->length
)) {
220 pkt
->type
= sftp_pkt_getbyte(pkt
);
225 /* ----------------------------------------------------------------------
226 * String handling routines.
229 static char *mkstr(char *s
, int len
)
231 char *p
= smalloc(len
+ 1);
237 /* ----------------------------------------------------------------------
242 * Deal with (and free) an FXP_STATUS packet. Return 1 if
243 * SSH_FX_OK, 0 if SSH_FX_EOF, and -1 for anything else (error).
244 * Also place the status into fxp_errtype.
246 static int fxp_got_status(struct sftp_packet
*pktin
)
248 static const char *const messages
[] = {
249 /* SSH_FX_OK. The only time we will display a _message_ for this
250 * is if we were expecting something other than FXP_STATUS on
251 * success, so this is actually an error message! */
252 "unexpected OK response",
254 "no such file or directory",
260 "operation unsupported",
263 if (pktin
->type
!= SSH_FXP_STATUS
) {
264 fxp_error_message
= "expected FXP_STATUS packet";
267 fxp_errtype
= sftp_pkt_getuint32(pktin
);
268 if (fxp_errtype
< 0 ||
269 fxp_errtype
>= sizeof(messages
) / sizeof(*messages
))
270 fxp_error_message
= "unknown error code";
272 fxp_error_message
= messages
[fxp_errtype
];
275 if (fxp_errtype
== SSH_FX_OK
)
277 else if (fxp_errtype
== SSH_FX_EOF
)
283 static void fxp_internal_error(char *msg
)
285 fxp_error_message
= msg
;
289 const char *fxp_error(void)
291 return fxp_error_message
;
294 int fxp_error_type(void)
300 * Perform exchange of init/version packets. Return 0 on failure.
304 struct sftp_packet
*pktout
, *pktin
;
307 pktout
= sftp_pkt_init(SSH_FXP_INIT
);
308 sftp_pkt_adduint32(pktout
, SFTP_PROTO_VERSION
);
313 fxp_internal_error("could not connect");
316 if (pktin
->type
!= SSH_FXP_VERSION
) {
317 fxp_internal_error("did not receive FXP_VERSION");
320 remotever
= sftp_pkt_getuint32(pktin
);
321 if (remotever
> SFTP_PROTO_VERSION
) {
323 ("remote protocol is more advanced than we support");
327 * In principle, this packet might also contain extension-
328 * string pairs. We should work through them and look for any
329 * we recognise. In practice we don't currently do so because
330 * we know we don't recognise _any_.
332 sftp_pkt_free(pktin
);
338 * Canonify a pathname.
340 char *fxp_realpath(char *path
)
342 struct sftp_packet
*pktin
, *pktout
;
345 pktout
= sftp_pkt_init(SSH_FXP_REALPATH
);
346 sftp_pkt_adduint32(pktout
, 0x123); /* request id */
347 sftp_pkt_addstring_start(pktout
);
348 sftp_pkt_addstring_str(pktout
, path
);
351 id
= sftp_pkt_getuint32(pktin
);
353 fxp_internal_error("request ID mismatch\n");
356 if (pktin
->type
== SSH_FXP_NAME
) {
361 count
= sftp_pkt_getuint32(pktin
);
363 fxp_internal_error("REALPATH returned name count != 1\n");
366 sftp_pkt_getstring(pktin
, &path
, &len
);
368 fxp_internal_error("REALPATH returned malformed FXP_NAME\n");
371 path
= mkstr(path
, len
);
372 sftp_pkt_free(pktin
);
375 fxp_got_status(pktin
);
383 struct fxp_handle
*fxp_open(char *path
, int type
)
385 struct sftp_packet
*pktin
, *pktout
;
388 pktout
= sftp_pkt_init(SSH_FXP_OPEN
);
389 sftp_pkt_adduint32(pktout
, 0x567); /* request id */
390 sftp_pkt_addstring(pktout
, path
);
391 sftp_pkt_adduint32(pktout
, type
);
392 sftp_pkt_adduint32(pktout
, 0); /* (FIXME) empty ATTRS structure */
395 id
= sftp_pkt_getuint32(pktin
);
397 fxp_internal_error("request ID mismatch\n");
400 if (pktin
->type
== SSH_FXP_HANDLE
) {
402 struct fxp_handle
*handle
;
405 sftp_pkt_getstring(pktin
, &hstring
, &len
);
407 fxp_internal_error("OPEN returned malformed FXP_HANDLE\n");
410 handle
= smalloc(sizeof(struct fxp_handle
));
411 handle
->hstring
= mkstr(hstring
, len
);
413 sftp_pkt_free(pktin
);
416 fxp_got_status(pktin
);
424 struct fxp_handle
*fxp_opendir(char *path
)
426 struct sftp_packet
*pktin
, *pktout
;
429 pktout
= sftp_pkt_init(SSH_FXP_OPENDIR
);
430 sftp_pkt_adduint32(pktout
, 0x456); /* request id */
431 sftp_pkt_addstring(pktout
, path
);
434 id
= sftp_pkt_getuint32(pktin
);
436 fxp_internal_error("request ID mismatch\n");
439 if (pktin
->type
== SSH_FXP_HANDLE
) {
441 struct fxp_handle
*handle
;
444 sftp_pkt_getstring(pktin
, &hstring
, &len
);
446 fxp_internal_error("OPENDIR returned malformed FXP_HANDLE\n");
449 handle
= smalloc(sizeof(struct fxp_handle
));
450 handle
->hstring
= mkstr(hstring
, len
);
452 sftp_pkt_free(pktin
);
455 fxp_got_status(pktin
);
463 void fxp_close(struct fxp_handle
*handle
)
465 struct sftp_packet
*pktin
, *pktout
;
468 pktout
= sftp_pkt_init(SSH_FXP_CLOSE
);
469 sftp_pkt_adduint32(pktout
, 0x789); /* request id */
470 sftp_pkt_addstring_start(pktout
);
471 sftp_pkt_addstring_data(pktout
, handle
->hstring
, handle
->hlen
);
474 id
= sftp_pkt_getuint32(pktin
);
476 fxp_internal_error("request ID mismatch\n");
479 fxp_got_status(pktin
);
480 sfree(handle
->hstring
);
484 int fxp_mkdir(char *path
)
486 struct sftp_packet
*pktin
, *pktout
;
489 pktout
= sftp_pkt_init(SSH_FXP_MKDIR
);
490 sftp_pkt_adduint32(pktout
, 0x234); /* request id */
491 sftp_pkt_addstring_start(pktout
);
492 sftp_pkt_addstring_data(pktout
, path
, strlen(path
));
493 sftp_pkt_adduint32(pktout
, 0); /* (FIXME) empty ATTRS structure */
496 id
= sftp_pkt_getuint32(pktin
);
498 fxp_internal_error("request ID mismatch\n");
501 id
= fxp_got_status(pktin
);
508 int fxp_rmdir(char *path
)
510 struct sftp_packet
*pktin
, *pktout
;
513 pktout
= sftp_pkt_init(SSH_FXP_RMDIR
);
514 sftp_pkt_adduint32(pktout
, 0x345); /* request id */
515 sftp_pkt_addstring_start(pktout
);
516 sftp_pkt_addstring_data(pktout
, path
, strlen(path
));
519 id
= sftp_pkt_getuint32(pktin
);
521 fxp_internal_error("request ID mismatch\n");
524 id
= fxp_got_status(pktin
);
531 int fxp_rm(char *fname
)
533 struct sftp_packet
*pktin
, *pktout
;
536 pktout
= sftp_pkt_init(SSH_FXP_REMOVE
);
537 sftp_pkt_adduint32(pktout
, 0x678); /* request id */
538 sftp_pkt_addstring_start(pktout
);
539 sftp_pkt_addstring_data(pktout
, fname
, strlen(fname
));
542 id
= sftp_pkt_getuint32(pktin
);
544 fxp_internal_error("request ID mismatch\n");
547 id
= fxp_got_status(pktin
);
555 * Read from a file. Returns the number of bytes read, or -1 on an
556 * error, or possibly 0 if EOF. (I'm not entirely sure whether it
557 * will return 0 on EOF, or return -1 and store SSH_FX_EOF in the
558 * error indicator. It might even depend on the SFTP server.)
560 int fxp_read(struct fxp_handle
*handle
, char *buffer
, uint64 offset
,
563 struct sftp_packet
*pktin
, *pktout
;
566 pktout
= sftp_pkt_init(SSH_FXP_READ
);
567 sftp_pkt_adduint32(pktout
, 0xBCD); /* request id */
568 sftp_pkt_addstring_start(pktout
);
569 sftp_pkt_addstring_data(pktout
, handle
->hstring
, handle
->hlen
);
570 sftp_pkt_adduint64(pktout
, offset
);
571 sftp_pkt_adduint32(pktout
, len
);
574 id
= sftp_pkt_getuint32(pktin
);
576 fxp_internal_error("request ID mismatch");
579 if (pktin
->type
== SSH_FXP_DATA
) {
583 sftp_pkt_getstring(pktin
, &str
, &rlen
);
585 if (rlen
> len
|| rlen
< 0) {
586 fxp_internal_error("READ returned more bytes than requested");
590 memcpy(buffer
, str
, rlen
);
594 fxp_got_status(pktin
);
600 * Read from a directory.
602 struct fxp_names
*fxp_readdir(struct fxp_handle
*handle
)
604 struct sftp_packet
*pktin
, *pktout
;
607 pktout
= sftp_pkt_init(SSH_FXP_READDIR
);
608 sftp_pkt_adduint32(pktout
, 0xABC); /* request id */
609 sftp_pkt_addstring_start(pktout
);
610 sftp_pkt_addstring_data(pktout
, handle
->hstring
, handle
->hlen
);
613 id
= sftp_pkt_getuint32(pktin
);
615 fxp_internal_error("request ID mismatch\n");
618 if (pktin
->type
== SSH_FXP_NAME
) {
619 struct fxp_names
*ret
;
621 ret
= smalloc(sizeof(struct fxp_names
));
622 ret
->nnames
= sftp_pkt_getuint32(pktin
);
623 ret
->names
= smalloc(ret
->nnames
* sizeof(struct fxp_name
));
624 for (i
= 0; i
< ret
->nnames
; i
++) {
627 sftp_pkt_getstring(pktin
, &str
, &len
);
628 ret
->names
[i
].filename
= mkstr(str
, len
);
629 sftp_pkt_getstring(pktin
, &str
, &len
);
630 ret
->names
[i
].longname
= mkstr(str
, len
);
631 ret
->names
[i
].attrs
= sftp_pkt_getattrs(pktin
);
635 fxp_got_status(pktin
);
641 * Write to a file. Returns 0 on error, 1 on OK.
643 int fxp_write(struct fxp_handle
*handle
, char *buffer
, uint64 offset
,
646 struct sftp_packet
*pktin
, *pktout
;
649 pktout
= sftp_pkt_init(SSH_FXP_WRITE
);
650 sftp_pkt_adduint32(pktout
, 0xDCB); /* request id */
651 sftp_pkt_addstring_start(pktout
);
652 sftp_pkt_addstring_data(pktout
, handle
->hstring
, handle
->hlen
);
653 sftp_pkt_adduint64(pktout
, offset
);
654 sftp_pkt_addstring_start(pktout
);
655 sftp_pkt_addstring_data(pktout
, buffer
, len
);
658 id
= sftp_pkt_getuint32(pktin
);
660 fxp_internal_error("request ID mismatch\n");
663 fxp_got_status(pktin
);
664 return fxp_errtype
== SSH_FX_OK
;
668 * Free up an fxp_names structure.
670 void fxp_free_names(struct fxp_names
*names
)
674 for (i
= 0; i
< names
->nnames
; i
++) {
675 sfree(names
->names
[i
].filename
);
676 sfree(names
->names
[i
].longname
);