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 /* ----------------------------------------------------------------------
37 * SFTP packet construction functions.
39 static void sftp_pkt_ensure(struct sftp_packet
*pkt
, int length
)
41 if (pkt
->maxlen
< length
) {
42 pkt
->maxlen
= length
+ 256;
43 pkt
->data
= srealloc(pkt
->data
, pkt
->maxlen
);
46 static void sftp_pkt_adddata(struct sftp_packet
*pkt
, void *data
, int len
)
49 sftp_pkt_ensure(pkt
, pkt
->length
);
50 memcpy(pkt
->data
+ pkt
->length
- len
, data
, len
);
52 static void sftp_pkt_addbyte(struct sftp_packet
*pkt
, unsigned char byte
)
54 sftp_pkt_adddata(pkt
, &byte
, 1);
56 static struct sftp_packet
*sftp_pkt_init(int pkt_type
)
58 struct sftp_packet
*pkt
;
59 pkt
= smalloc(sizeof(struct sftp_packet
));
64 sftp_pkt_addbyte(pkt
, (unsigned char) pkt_type
);
67 static void sftp_pkt_addbool(struct sftp_packet
*pkt
, unsigned char value
)
69 sftp_pkt_adddata(pkt
, &value
, 1);
71 static void sftp_pkt_adduint32(struct sftp_packet
*pkt
,
76 sftp_pkt_adddata(pkt
, x
, 4);
78 static void sftp_pkt_adduint64(struct sftp_packet
*pkt
, uint64 value
)
81 PUT_32BIT(x
, value
.hi
);
82 PUT_32BIT(x
+ 4, value
.lo
);
83 sftp_pkt_adddata(pkt
, x
, 8);
85 static void sftp_pkt_addstring_start(struct sftp_packet
*pkt
)
87 sftp_pkt_adduint32(pkt
, 0);
88 pkt
->savedpos
= pkt
->length
;
90 static void sftp_pkt_addstring_str(struct sftp_packet
*pkt
, char *data
)
92 sftp_pkt_adddata(pkt
, data
, strlen(data
));
93 PUT_32BIT(pkt
->data
+ pkt
->savedpos
- 4, pkt
->length
- pkt
->savedpos
);
95 static void sftp_pkt_addstring_data(struct sftp_packet
*pkt
,
98 sftp_pkt_adddata(pkt
, data
, len
);
99 PUT_32BIT(pkt
->data
+ pkt
->savedpos
- 4, pkt
->length
- pkt
->savedpos
);
101 static void sftp_pkt_addstring(struct sftp_packet
*pkt
, char *data
)
103 sftp_pkt_addstring_start(pkt
);
104 sftp_pkt_addstring_str(pkt
, data
);
107 /* ----------------------------------------------------------------------
108 * SFTP packet decode functions.
111 static unsigned char sftp_pkt_getbyte(struct sftp_packet
*pkt
)
114 if (pkt
->length
- pkt
->savedpos
< 1)
115 return 0; /* arrgh, no way to decline (FIXME?) */
116 value
= (unsigned char) pkt
->data
[pkt
->savedpos
];
120 static unsigned long sftp_pkt_getuint32(struct sftp_packet
*pkt
)
123 if (pkt
->length
- pkt
->savedpos
< 4)
124 return 0; /* arrgh, no way to decline (FIXME?) */
125 value
= GET_32BIT(pkt
->data
+ pkt
->savedpos
);
129 static void sftp_pkt_getstring(struct sftp_packet
*pkt
,
130 char **p
, int *length
)
133 if (pkt
->length
- pkt
->savedpos
< 4)
135 *length
= GET_32BIT(pkt
->data
+ pkt
->savedpos
);
137 if (pkt
->length
- pkt
->savedpos
< *length
)
139 *p
= pkt
->data
+ pkt
->savedpos
;
140 pkt
->savedpos
+= *length
;
142 static struct fxp_attrs
sftp_pkt_getattrs(struct sftp_packet
*pkt
)
144 struct fxp_attrs ret
;
145 ret
.flags
= sftp_pkt_getuint32(pkt
);
146 if (ret
.flags
& SSH_FILEXFER_ATTR_SIZE
) {
147 unsigned long hi
, lo
;
148 hi
= sftp_pkt_getuint32(pkt
);
149 lo
= sftp_pkt_getuint32(pkt
);
150 ret
.size
= uint64_make(hi
, lo
);
152 if (ret
.flags
& SSH_FILEXFER_ATTR_UIDGID
) {
153 ret
.uid
= sftp_pkt_getuint32(pkt
);
154 ret
.gid
= sftp_pkt_getuint32(pkt
);
156 if (ret
.flags
& SSH_FILEXFER_ATTR_PERMISSIONS
) {
157 ret
.permissions
= sftp_pkt_getuint32(pkt
);
159 if (ret
.flags
& SSH_FILEXFER_ATTR_ACMODTIME
) {
160 ret
.atime
= sftp_pkt_getuint32(pkt
);
161 ret
.mtime
= sftp_pkt_getuint32(pkt
);
163 if (ret
.flags
& SSH_FILEXFER_ATTR_EXTENDED
) {
165 count
= sftp_pkt_getuint32(pkt
);
170 * We should try to analyse these, if we ever find one
173 sftp_pkt_getstring(pkt
, &str
, &len
);
174 sftp_pkt_getstring(pkt
, &str
, &len
);
179 static void sftp_pkt_free(struct sftp_packet
*pkt
)
186 /* ----------------------------------------------------------------------
187 * Send and receive packet functions.
189 int sftp_send(struct sftp_packet
*pkt
)
193 PUT_32BIT(x
, pkt
->length
);
194 ret
= (sftp_senddata(x
, 4) && sftp_senddata(pkt
->data
, pkt
->length
));
198 struct sftp_packet
*sftp_recv(void)
200 struct sftp_packet
*pkt
;
203 if (!sftp_recvdata(x
, 4))
206 pkt
= smalloc(sizeof(struct sftp_packet
));
208 pkt
->length
= pkt
->maxlen
= GET_32BIT(x
);
209 pkt
->data
= smalloc(pkt
->length
);
211 if (!sftp_recvdata(pkt
->data
, pkt
->length
)) {
216 pkt
->type
= sftp_pkt_getbyte(pkt
);
221 /* ----------------------------------------------------------------------
222 * String handling routines.
225 static char *mkstr(char *s
, int len
)
227 char *p
= smalloc(len
+ 1);
233 /* ----------------------------------------------------------------------
237 static const char *fxp_error_message
;
238 static int fxp_errtype
;
241 * Deal with (and free) an FXP_STATUS packet. Return 1 if
242 * SSH_FX_OK, 0 if SSH_FX_EOF, and -1 for anything else (error).
243 * Also place the status into fxp_errtype.
245 static int fxp_got_status(struct sftp_packet
*pktin
)
247 static const char *const messages
[] = {
248 /* SSH_FX_OK. The only time we will display a _message_ for this
249 * is if we were expecting something other than FXP_STATUS on
250 * success, so this is actually an error message! */
251 "unexpected OK response",
253 "no such file or directory",
259 "operation unsupported",
262 if (pktin
->type
!= SSH_FXP_STATUS
) {
263 fxp_error_message
= "expected FXP_STATUS packet";
266 fxp_errtype
= sftp_pkt_getuint32(pktin
);
267 if (fxp_errtype
< 0 ||
268 fxp_errtype
>= sizeof(messages
) / sizeof(*messages
))
269 fxp_error_message
= "unknown error code";
271 fxp_error_message
= messages
[fxp_errtype
];
274 if (fxp_errtype
== SSH_FX_OK
)
276 else if (fxp_errtype
== SSH_FX_EOF
)
282 static void fxp_internal_error(char *msg
)
284 fxp_error_message
= msg
;
288 const char *fxp_error(void)
290 return fxp_error_message
;
293 int fxp_error_type(void)
299 * Perform exchange of init/version packets. Return 0 on failure.
303 struct sftp_packet
*pktout
, *pktin
;
306 pktout
= sftp_pkt_init(SSH_FXP_INIT
);
307 sftp_pkt_adduint32(pktout
, SFTP_PROTO_VERSION
);
312 fxp_internal_error("could not connect");
315 if (pktin
->type
!= SSH_FXP_VERSION
) {
316 fxp_internal_error("did not receive FXP_VERSION");
319 remotever
= sftp_pkt_getuint32(pktin
);
320 if (remotever
> SFTP_PROTO_VERSION
) {
322 ("remote protocol is more advanced than we support");
326 * In principle, this packet might also contain extension-
327 * string pairs. We should work through them and look for any
328 * we recognise. In practice we don't currently do so because
329 * we know we don't recognise _any_.
331 sftp_pkt_free(pktin
);
337 * Canonify a pathname.
339 char *fxp_realpath(char *path
)
341 struct sftp_packet
*pktin
, *pktout
;
344 pktout
= sftp_pkt_init(SSH_FXP_REALPATH
);
345 sftp_pkt_adduint32(pktout
, 0x123); /* request id */
346 sftp_pkt_addstring_start(pktout
);
347 sftp_pkt_addstring_str(pktout
, path
);
350 id
= sftp_pkt_getuint32(pktin
);
352 fxp_internal_error("request ID mismatch\n");
355 if (pktin
->type
== SSH_FXP_NAME
) {
360 count
= sftp_pkt_getuint32(pktin
);
362 fxp_internal_error("REALPATH returned name count != 1\n");
365 sftp_pkt_getstring(pktin
, &path
, &len
);
367 fxp_internal_error("REALPATH returned malformed FXP_NAME\n");
370 path
= mkstr(path
, len
);
371 sftp_pkt_free(pktin
);
374 fxp_got_status(pktin
);
382 struct fxp_handle
*fxp_open(char *path
, int type
)
384 struct sftp_packet
*pktin
, *pktout
;
387 pktout
= sftp_pkt_init(SSH_FXP_OPEN
);
388 sftp_pkt_adduint32(pktout
, 0x567); /* request id */
389 sftp_pkt_addstring(pktout
, path
);
390 sftp_pkt_adduint32(pktout
, type
);
391 sftp_pkt_adduint32(pktout
, 0); /* (FIXME) empty ATTRS structure */
394 id
= sftp_pkt_getuint32(pktin
);
396 fxp_internal_error("request ID mismatch\n");
399 if (pktin
->type
== SSH_FXP_HANDLE
) {
401 struct fxp_handle
*handle
;
404 sftp_pkt_getstring(pktin
, &hstring
, &len
);
406 fxp_internal_error("OPEN returned malformed FXP_HANDLE\n");
409 handle
= smalloc(sizeof(struct fxp_handle
));
410 handle
->hstring
= mkstr(hstring
, len
);
412 sftp_pkt_free(pktin
);
415 fxp_got_status(pktin
);
423 struct fxp_handle
*fxp_opendir(char *path
)
425 struct sftp_packet
*pktin
, *pktout
;
428 pktout
= sftp_pkt_init(SSH_FXP_OPENDIR
);
429 sftp_pkt_adduint32(pktout
, 0x456); /* request id */
430 sftp_pkt_addstring(pktout
, path
);
433 id
= sftp_pkt_getuint32(pktin
);
435 fxp_internal_error("request ID mismatch\n");
438 if (pktin
->type
== SSH_FXP_HANDLE
) {
440 struct fxp_handle
*handle
;
443 sftp_pkt_getstring(pktin
, &hstring
, &len
);
445 fxp_internal_error("OPENDIR returned malformed FXP_HANDLE\n");
448 handle
= smalloc(sizeof(struct fxp_handle
));
449 handle
->hstring
= mkstr(hstring
, len
);
451 sftp_pkt_free(pktin
);
454 fxp_got_status(pktin
);
462 void fxp_close(struct fxp_handle
*handle
)
464 struct sftp_packet
*pktin
, *pktout
;
467 pktout
= sftp_pkt_init(SSH_FXP_CLOSE
);
468 sftp_pkt_adduint32(pktout
, 0x789); /* request id */
469 sftp_pkt_addstring_start(pktout
);
470 sftp_pkt_addstring_data(pktout
, handle
->hstring
, handle
->hlen
);
473 id
= sftp_pkt_getuint32(pktin
);
475 fxp_internal_error("request ID mismatch\n");
478 fxp_got_status(pktin
);
479 sfree(handle
->hstring
);
484 * Read from a file. Returns the number of bytes read, or -1 on an
485 * error, or possibly 0 if EOF. (I'm not entirely sure whether it
486 * will return 0 on EOF, or return -1 and store SSH_FX_EOF in the
487 * error indicator. It might even depend on the SFTP server.)
489 int fxp_read(struct fxp_handle
*handle
, char *buffer
, uint64 offset
,
492 struct sftp_packet
*pktin
, *pktout
;
495 pktout
= sftp_pkt_init(SSH_FXP_READ
);
496 sftp_pkt_adduint32(pktout
, 0xBCD); /* request id */
497 sftp_pkt_addstring_start(pktout
);
498 sftp_pkt_addstring_data(pktout
, handle
->hstring
, handle
->hlen
);
499 sftp_pkt_adduint64(pktout
, offset
);
500 sftp_pkt_adduint32(pktout
, len
);
503 id
= sftp_pkt_getuint32(pktin
);
505 fxp_internal_error("request ID mismatch");
508 if (pktin
->type
== SSH_FXP_DATA
) {
512 sftp_pkt_getstring(pktin
, &str
, &rlen
);
514 if (rlen
> len
|| rlen
< 0) {
515 fxp_internal_error("READ returned more bytes than requested");
519 memcpy(buffer
, str
, rlen
);
523 fxp_got_status(pktin
);
529 * Read from a directory.
531 struct fxp_names
*fxp_readdir(struct fxp_handle
*handle
)
533 struct sftp_packet
*pktin
, *pktout
;
536 pktout
= sftp_pkt_init(SSH_FXP_READDIR
);
537 sftp_pkt_adduint32(pktout
, 0xABC); /* request id */
538 sftp_pkt_addstring_start(pktout
);
539 sftp_pkt_addstring_data(pktout
, handle
->hstring
, handle
->hlen
);
542 id
= sftp_pkt_getuint32(pktin
);
544 fxp_internal_error("request ID mismatch\n");
547 if (pktin
->type
== SSH_FXP_NAME
) {
548 struct fxp_names
*ret
;
550 ret
= smalloc(sizeof(struct fxp_names
));
551 ret
->nnames
= sftp_pkt_getuint32(pktin
);
552 ret
->names
= smalloc(ret
->nnames
* sizeof(struct fxp_name
));
553 for (i
= 0; i
< ret
->nnames
; i
++) {
556 sftp_pkt_getstring(pktin
, &str
, &len
);
557 ret
->names
[i
].filename
= mkstr(str
, len
);
558 sftp_pkt_getstring(pktin
, &str
, &len
);
559 ret
->names
[i
].longname
= mkstr(str
, len
);
560 ret
->names
[i
].attrs
= sftp_pkt_getattrs(pktin
);
564 fxp_got_status(pktin
);
570 * Write to a file. Returns 0 on error, 1 on OK.
572 int fxp_write(struct fxp_handle
*handle
, char *buffer
, uint64 offset
,
575 struct sftp_packet
*pktin
, *pktout
;
578 pktout
= sftp_pkt_init(SSH_FXP_WRITE
);
579 sftp_pkt_adduint32(pktout
, 0xDCB); /* request id */
580 sftp_pkt_addstring_start(pktout
);
581 sftp_pkt_addstring_data(pktout
, handle
->hstring
, handle
->hlen
);
582 sftp_pkt_adduint64(pktout
, offset
);
583 sftp_pkt_addstring_start(pktout
);
584 sftp_pkt_addstring_data(pktout
, buffer
, len
);
587 id
= sftp_pkt_getuint32(pktin
);
589 fxp_internal_error("request ID mismatch\n");
592 fxp_got_status(pktin
);
593 return fxp_errtype
== SSH_FX_OK
;
597 * Free up an fxp_names structure.
599 void fxp_free_names(struct fxp_names
*names
)
603 for (i
= 0; i
< names
->nnames
; i
++) {
604 sfree(names
->names
[i
].filename
);
605 sfree(names
->names
[i
].longname
);