2 * sftp.c: SFTP generic client code.
14 #define GET_32BIT(cp) \
15 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
16 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
17 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
18 ((unsigned long)(unsigned char)(cp)[3]))
20 #define PUT_32BIT(cp, value) { \
21 (cp)[0] = (unsigned char)((value) >> 24); \
22 (cp)[1] = (unsigned char)((value) >> 16); \
23 (cp)[2] = (unsigned char)((value) >> 8); \
24 (cp)[3] = (unsigned char)(value); }
33 static const char *fxp_error_message;
34 static int fxp_errtype;
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);
106 static void sftp_pkt_addattrs(struct sftp_packet *pkt, struct fxp_attrs attrs)
108 sftp_pkt_adduint32(pkt, attrs.flags);
109 if (attrs.flags & SSH_FILEXFER_ATTR_SIZE) {
110 sftp_pkt_adduint32(pkt, attrs.size.hi);
111 sftp_pkt_adduint32(pkt, attrs.size.lo);
113 if (attrs.flags & SSH_FILEXFER_ATTR_UIDGID) {
114 sftp_pkt_adduint32(pkt, attrs.uid);
115 sftp_pkt_adduint32(pkt, attrs.gid);
117 if (attrs.flags & SSH_FILEXFER_ATTR_PERMISSIONS) {
118 sftp_pkt_adduint32(pkt, attrs.permissions);
120 if (attrs.flags & SSH_FILEXFER_ATTR_ACMODTIME) {
121 sftp_pkt_adduint32(pkt, attrs.atime);
122 sftp_pkt_adduint32(pkt, attrs.mtime);
124 if (attrs.flags & SSH_FILEXFER_ATTR_EXTENDED) {
126 * We currently don't support sending any extended
132 /* ----------------------------------------------------------------------
133 * SFTP packet decode functions.
136 static unsigned char sftp_pkt_getbyte(struct sftp_packet *pkt)
139 if (pkt->length - pkt->savedpos < 1)
140 return 0; /* arrgh, no way to decline (FIXME?) */
141 value = (unsigned char) pkt->data[pkt->savedpos];
145 static unsigned long sftp_pkt_getuint32(struct sftp_packet *pkt)
148 if (pkt->length - pkt->savedpos < 4)
149 return 0; /* arrgh, no way to decline (FIXME?) */
150 value = GET_32BIT(pkt->data + pkt->savedpos);
154 static void sftp_pkt_getstring(struct sftp_packet *pkt,
155 char **p, int *length)
158 if (pkt->length - pkt->savedpos < 4)
160 *length = GET_32BIT(pkt->data + pkt->savedpos);
162 if (pkt->length - pkt->savedpos < *length)
164 *p = pkt->data + pkt->savedpos;
165 pkt->savedpos += *length;
167 static struct fxp_attrs sftp_pkt_getattrs(struct sftp_packet *pkt)
169 struct fxp_attrs ret;
170 ret.flags = sftp_pkt_getuint32(pkt);
171 if (ret.flags & SSH_FILEXFER_ATTR_SIZE) {
172 unsigned long hi, lo;
173 hi = sftp_pkt_getuint32(pkt);
174 lo = sftp_pkt_getuint32(pkt);
175 ret.size = uint64_make(hi, lo);
177 if (ret.flags & SSH_FILEXFER_ATTR_UIDGID) {
178 ret.uid = sftp_pkt_getuint32(pkt);
179 ret.gid = sftp_pkt_getuint32(pkt);
181 if (ret.flags & SSH_FILEXFER_ATTR_PERMISSIONS) {
182 ret.permissions = sftp_pkt_getuint32(pkt);
184 if (ret.flags & SSH_FILEXFER_ATTR_ACMODTIME) {
185 ret.atime = sftp_pkt_getuint32(pkt);
186 ret.mtime = sftp_pkt_getuint32(pkt);
188 if (ret.flags & SSH_FILEXFER_ATTR_EXTENDED) {
190 count = sftp_pkt_getuint32(pkt);
195 * We should try to analyse these, if we ever find one
198 sftp_pkt_getstring(pkt, &str, &len);
199 sftp_pkt_getstring(pkt, &str, &len);
204 static void sftp_pkt_free(struct sftp_packet *pkt)
211 /* ----------------------------------------------------------------------
212 * Send and receive packet functions.
214 int sftp_send(struct sftp_packet *pkt)
218 PUT_32BIT(x, pkt->length);
219 ret = (sftp_senddata(x, 4) && sftp_senddata(pkt->data, pkt->length));
223 struct sftp_packet *sftp_recv(void)
225 struct sftp_packet *pkt;
228 if (!sftp_recvdata(x, 4))
231 pkt = smalloc(sizeof(struct sftp_packet));
233 pkt->length = pkt->maxlen = GET_32BIT(x);
234 pkt->data = smalloc(pkt->length);
236 if (!sftp_recvdata(pkt->data, pkt->length)) {
241 pkt->type = sftp_pkt_getbyte(pkt);
246 /* ----------------------------------------------------------------------
247 * String handling routines.
250 static char *mkstr(char *s, int len)
252 char *p = smalloc(len + 1);
258 /* ----------------------------------------------------------------------
263 * Deal with (and free) an FXP_STATUS packet. Return 1 if
264 * SSH_FX_OK, 0 if SSH_FX_EOF, and -1 for anything else (error).
265 * Also place the status into fxp_errtype.
267 static int fxp_got_status(struct sftp_packet *pktin)
269 static const char *const messages[] = {
270 /* SSH_FX_OK. The only time we will display a _message_ for this
271 * is if we were expecting something other than FXP_STATUS on
272 * success, so this is actually an error message! */
273 "unexpected OK response",
275 "no such file or directory",
281 "operation unsupported",
284 if (pktin->type != SSH_FXP_STATUS) {
285 fxp_error_message = "expected FXP_STATUS packet";
288 fxp_errtype = sftp_pkt_getuint32(pktin);
289 if (fxp_errtype < 0 ||
290 fxp_errtype >= sizeof(messages) / sizeof(*messages))
291 fxp_error_message = "unknown error code";
293 fxp_error_message = messages[fxp_errtype];
296 if (fxp_errtype == SSH_FX_OK)
298 else if (fxp_errtype == SSH_FX_EOF)
304 static void fxp_internal_error(char *msg)
306 fxp_error_message = msg;
310 const char *fxp_error(void)
312 return fxp_error_message;
315 int fxp_error_type(void)
321 * Perform exchange of init/version packets. Return 0 on failure.
325 struct sftp_packet *pktout, *pktin;
328 pktout = sftp_pkt_init(SSH_FXP_INIT);
329 sftp_pkt_adduint32(pktout, SFTP_PROTO_VERSION);
334 fxp_internal_error("could not connect");
337 if (pktin->type != SSH_FXP_VERSION) {
338 fxp_internal_error("did not receive FXP_VERSION");
341 remotever = sftp_pkt_getuint32(pktin);
342 if (remotever > SFTP_PROTO_VERSION) {
344 ("remote protocol is more advanced than we support");
348 * In principle, this packet might also contain extension-
349 * string pairs. We should work through them and look for any
350 * we recognise. In practice we don't currently do so because
351 * we know we don't recognise _any_.
353 sftp_pkt_free(pktin);
359 * Canonify a pathname.
361 char *fxp_realpath(char *path)
363 struct sftp_packet *pktin, *pktout;
366 pktout = sftp_pkt_init(SSH_FXP_REALPATH);
367 sftp_pkt_adduint32(pktout, 0x123); /* request id */
368 sftp_pkt_addstring_start(pktout);
369 sftp_pkt_addstring_str(pktout, path);
373 fxp_internal_error("did not receive a valid SFTP packet\n");
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 */
421 fxp_internal_error("did not receive a valid SFTP packet\n");
424 id = sftp_pkt_getuint32(pktin);
426 fxp_internal_error("request ID mismatch\n");
429 if (pktin->type == SSH_FXP_HANDLE) {
431 struct fxp_handle *handle;
434 sftp_pkt_getstring(pktin, &hstring, &len);
436 fxp_internal_error("OPEN returned malformed FXP_HANDLE\n");
439 handle = smalloc(sizeof(struct fxp_handle));
440 handle->hstring = mkstr(hstring, len);
442 sftp_pkt_free(pktin);
445 fxp_got_status(pktin);
453 struct fxp_handle *fxp_opendir(char *path)
455 struct sftp_packet *pktin, *pktout;
458 pktout = sftp_pkt_init(SSH_FXP_OPENDIR);
459 sftp_pkt_adduint32(pktout, 0x456); /* request id */
460 sftp_pkt_addstring(pktout, path);
464 fxp_internal_error("did not receive a valid SFTP packet\n");
467 id = sftp_pkt_getuint32(pktin);
469 fxp_internal_error("request ID mismatch\n");
472 if (pktin->type == SSH_FXP_HANDLE) {
474 struct fxp_handle *handle;
477 sftp_pkt_getstring(pktin, &hstring, &len);
479 fxp_internal_error("OPENDIR returned malformed FXP_HANDLE\n");
482 handle = smalloc(sizeof(struct fxp_handle));
483 handle->hstring = mkstr(hstring, len);
485 sftp_pkt_free(pktin);
488 fxp_got_status(pktin);
496 void fxp_close(struct fxp_handle *handle)
498 struct sftp_packet *pktin, *pktout;
501 pktout = sftp_pkt_init(SSH_FXP_CLOSE);
502 sftp_pkt_adduint32(pktout, 0x789); /* request id */
503 sftp_pkt_addstring_start(pktout);
504 sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
508 fxp_internal_error("did not receive a valid SFTP packet\n");
511 id = sftp_pkt_getuint32(pktin);
513 fxp_internal_error("request ID mismatch\n");
516 fxp_got_status(pktin);
517 sfree(handle->hstring);
521 int fxp_mkdir(char *path)
523 struct sftp_packet *pktin, *pktout;
526 pktout = sftp_pkt_init(SSH_FXP_MKDIR);
527 sftp_pkt_adduint32(pktout, 0x234); /* request id */
528 sftp_pkt_addstring(pktout, path);
529 sftp_pkt_adduint32(pktout, 0); /* (FIXME) empty ATTRS structure */
533 fxp_internal_error("did not receive a valid SFTP packet\n");
536 id = sftp_pkt_getuint32(pktin);
538 fxp_internal_error("request ID mismatch\n");
541 id = fxp_got_status(pktin);
548 int fxp_rmdir(char *path)
550 struct sftp_packet *pktin, *pktout;
553 pktout = sftp_pkt_init(SSH_FXP_RMDIR);
554 sftp_pkt_adduint32(pktout, 0x345); /* request id */
555 sftp_pkt_addstring(pktout, path);
559 fxp_internal_error("did not receive a valid SFTP packet\n");
562 id = sftp_pkt_getuint32(pktin);
564 fxp_internal_error("request ID mismatch\n");
567 id = fxp_got_status(pktin);
574 int fxp_remove(char *fname)
576 struct sftp_packet *pktin, *pktout;
579 pktout = sftp_pkt_init(SSH_FXP_REMOVE);
580 sftp_pkt_adduint32(pktout, 0x678); /* request id */
581 sftp_pkt_addstring(pktout, fname);
585 fxp_internal_error("did not receive a valid SFTP packet\n");
588 id = sftp_pkt_getuint32(pktin);
590 fxp_internal_error("request ID mismatch\n");
593 id = fxp_got_status(pktin);
600 int fxp_rename(char *srcfname, char *dstfname)
602 struct sftp_packet *pktin, *pktout;
605 pktout = sftp_pkt_init(SSH_FXP_RENAME);
606 sftp_pkt_adduint32(pktout, 0x678); /* request id */
607 sftp_pkt_addstring(pktout, srcfname);
608 sftp_pkt_addstring(pktout, dstfname);
612 fxp_internal_error("did not receive a valid SFTP packet\n");
615 id = sftp_pkt_getuint32(pktin);
617 fxp_internal_error("request ID mismatch\n");
620 id = fxp_got_status(pktin);
628 * Retrieve the attributes of a file. We have fxp_stat which works
629 * on filenames, and fxp_fstat which works on open file handles.
631 int fxp_stat(char *fname, struct fxp_attrs *attrs)
633 struct sftp_packet *pktin, *pktout;
636 pktout = sftp_pkt_init(SSH_FXP_STAT);
637 sftp_pkt_adduint32(pktout, 0x678); /* request id */
638 sftp_pkt_addstring(pktout, fname);
642 fxp_internal_error("did not receive a valid SFTP packet\n");
645 id = sftp_pkt_getuint32(pktin);
647 fxp_internal_error("request ID mismatch\n");
651 if (pktin->type == SSH_FXP_ATTRS) {
652 *attrs = sftp_pkt_getattrs(pktin);
655 fxp_got_status(pktin);
660 int fxp_fstat(struct fxp_handle *handle, struct fxp_attrs *attrs)
662 struct sftp_packet *pktin, *pktout;
665 pktout = sftp_pkt_init(SSH_FXP_FSTAT);
666 sftp_pkt_adduint32(pktout, 0x678); /* request id */
667 sftp_pkt_addstring_start(pktout);
668 sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
672 fxp_internal_error("did not receive a valid SFTP packet\n");
675 id = sftp_pkt_getuint32(pktin);
677 fxp_internal_error("request ID mismatch\n");
681 if (pktin->type == SSH_FXP_ATTRS) {
682 *attrs = sftp_pkt_getattrs(pktin);
685 fxp_got_status(pktin);
691 * Set the attributes of a file.
693 int fxp_setstat(char *fname, struct fxp_attrs attrs)
695 struct sftp_packet *pktin, *pktout;
698 pktout = sftp_pkt_init(SSH_FXP_SETSTAT);
699 sftp_pkt_adduint32(pktout, 0x678); /* request id */
700 sftp_pkt_addstring(pktout, fname);
701 sftp_pkt_addattrs(pktout, attrs);
705 fxp_internal_error("did not receive a valid SFTP packet\n");
708 id = sftp_pkt_getuint32(pktin);
710 fxp_internal_error("request ID mismatch\n");
713 id = fxp_got_status(pktin);
719 int fxp_fsetstat(struct fxp_handle *handle, struct fxp_attrs attrs)
721 struct sftp_packet *pktin, *pktout;
724 pktout = sftp_pkt_init(SSH_FXP_FSETSTAT);
725 sftp_pkt_adduint32(pktout, 0x678); /* request id */
726 sftp_pkt_addstring_start(pktout);
727 sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
728 sftp_pkt_addattrs(pktout, attrs);
732 fxp_internal_error("did not receive a valid SFTP packet\n");
735 id = sftp_pkt_getuint32(pktin);
737 fxp_internal_error("request ID mismatch\n");
740 id = fxp_got_status(pktin);
748 * Read from a file. Returns the number of bytes read, or -1 on an
749 * error, or possibly 0 if EOF. (I'm not entirely sure whether it
750 * will return 0 on EOF, or return -1 and store SSH_FX_EOF in the
751 * error indicator. It might even depend on the SFTP server.)
753 int fxp_read(struct fxp_handle *handle, char *buffer, uint64 offset,
756 struct sftp_packet *pktin, *pktout;
759 pktout = sftp_pkt_init(SSH_FXP_READ);
760 sftp_pkt_adduint32(pktout, 0xBCD); /* request id */
761 sftp_pkt_addstring_start(pktout);
762 sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
763 sftp_pkt_adduint64(pktout, offset);
764 sftp_pkt_adduint32(pktout, len);
768 fxp_internal_error("did not receive a valid SFTP packet\n");
771 id = sftp_pkt_getuint32(pktin);
773 fxp_internal_error("request ID mismatch");
776 if (pktin->type == SSH_FXP_DATA) {
780 sftp_pkt_getstring(pktin, &str, &rlen);
782 if (rlen > len || rlen < 0) {
783 fxp_internal_error("READ returned more bytes than requested");
787 memcpy(buffer, str, rlen);
791 fxp_got_status(pktin);
797 * Read from a directory.
799 struct fxp_names *fxp_readdir(struct fxp_handle *handle)
801 struct sftp_packet *pktin, *pktout;
804 pktout = sftp_pkt_init(SSH_FXP_READDIR);
805 sftp_pkt_adduint32(pktout, 0xABC); /* request id */
806 sftp_pkt_addstring_start(pktout);
807 sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
811 fxp_internal_error("did not receive a valid SFTP packet\n");
814 id = sftp_pkt_getuint32(pktin);
816 fxp_internal_error("request ID mismatch\n");
819 if (pktin->type == SSH_FXP_NAME) {
820 struct fxp_names *ret;
822 ret = smalloc(sizeof(struct fxp_names));
823 ret->nnames = sftp_pkt_getuint32(pktin);
824 ret->names = smalloc(ret->nnames * sizeof(struct fxp_name));
825 for (i = 0; i < ret->nnames; i++) {
828 sftp_pkt_getstring(pktin, &str, &len);
829 ret->names[i].filename = mkstr(str, len);
830 sftp_pkt_getstring(pktin, &str, &len);
831 ret->names[i].longname = mkstr(str, len);
832 ret->names[i].attrs = sftp_pkt_getattrs(pktin);
836 fxp_got_status(pktin);
842 * Write to a file. Returns 0 on error, 1 on OK.
844 int fxp_write(struct fxp_handle *handle, char *buffer, uint64 offset,
847 struct sftp_packet *pktin, *pktout;
850 pktout = sftp_pkt_init(SSH_FXP_WRITE);
851 sftp_pkt_adduint32(pktout, 0xDCB); /* request id */
852 sftp_pkt_addstring_start(pktout);
853 sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
854 sftp_pkt_adduint64(pktout, offset);
855 sftp_pkt_addstring_start(pktout);
856 sftp_pkt_addstring_data(pktout, buffer, len);
860 fxp_internal_error("did not receive a valid SFTP packet\n");
863 id = sftp_pkt_getuint32(pktin);
865 fxp_internal_error("request ID mismatch\n");
868 fxp_got_status(pktin);
869 return fxp_errtype == SSH_FX_OK;
873 * Free up an fxp_names structure.
875 void fxp_free_names(struct fxp_names *names)
879 for (i = 0; i < names->nnames; i++) {
880 sfree(names->names[i].filename);
881 sfree(names->names[i].longname);