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");
339 sftp_pkt_free(pktin);
342 remotever = sftp_pkt_getuint32(pktin);
343 if (remotever > SFTP_PROTO_VERSION) {
345 ("remote protocol is more advanced than we support");
346 sftp_pkt_free(pktin);
350 * In principle, this packet might also contain extension-
351 * string pairs. We should work through them and look for any
352 * we recognise. In practice we don't currently do so because
353 * we know we don't recognise _any_.
355 sftp_pkt_free(pktin);
361 * Canonify a pathname.
363 char *fxp_realpath(char *path)
365 struct sftp_packet *pktin, *pktout;
368 pktout = sftp_pkt_init(SSH_FXP_REALPATH);
369 sftp_pkt_adduint32(pktout, 0x123); /* request id */
370 sftp_pkt_addstring_start(pktout);
371 sftp_pkt_addstring_str(pktout, path);
375 fxp_internal_error("did not receive a valid SFTP packet\n");
378 id = sftp_pkt_getuint32(pktin);
380 fxp_internal_error("request ID mismatch\n");
381 sftp_pkt_free(pktin);
384 if (pktin->type == SSH_FXP_NAME) {
389 count = sftp_pkt_getuint32(pktin);
391 fxp_internal_error("REALPATH returned name count != 1\n");
392 sftp_pkt_free(pktin);
395 sftp_pkt_getstring(pktin, &path, &len);
397 fxp_internal_error("REALPATH returned malformed FXP_NAME\n");
398 sftp_pkt_free(pktin);
401 path = mkstr(path, len);
402 sftp_pkt_free(pktin);
405 fxp_got_status(pktin);
406 sftp_pkt_free(pktin);
414 struct fxp_handle *fxp_open(char *path, int type)
416 struct sftp_packet *pktin, *pktout;
419 pktout = sftp_pkt_init(SSH_FXP_OPEN);
420 sftp_pkt_adduint32(pktout, 0x567); /* request id */
421 sftp_pkt_addstring(pktout, path);
422 sftp_pkt_adduint32(pktout, type);
423 sftp_pkt_adduint32(pktout, 0); /* (FIXME) empty ATTRS structure */
427 fxp_internal_error("did not receive a valid SFTP packet\n");
430 id = sftp_pkt_getuint32(pktin);
432 fxp_internal_error("request ID mismatch\n");
433 sftp_pkt_free(pktin);
436 if (pktin->type == SSH_FXP_HANDLE) {
438 struct fxp_handle *handle;
441 sftp_pkt_getstring(pktin, &hstring, &len);
443 fxp_internal_error("OPEN returned malformed FXP_HANDLE\n");
444 sftp_pkt_free(pktin);
447 handle = smalloc(sizeof(struct fxp_handle));
448 handle->hstring = mkstr(hstring, len);
450 sftp_pkt_free(pktin);
453 fxp_got_status(pktin);
454 sftp_pkt_free(pktin);
462 struct fxp_handle *fxp_opendir(char *path)
464 struct sftp_packet *pktin, *pktout;
467 pktout = sftp_pkt_init(SSH_FXP_OPENDIR);
468 sftp_pkt_adduint32(pktout, 0x456); /* request id */
469 sftp_pkt_addstring(pktout, path);
473 fxp_internal_error("did not receive a valid SFTP packet\n");
476 id = sftp_pkt_getuint32(pktin);
478 fxp_internal_error("request ID mismatch\n");
479 sftp_pkt_free(pktin);
482 if (pktin->type == SSH_FXP_HANDLE) {
484 struct fxp_handle *handle;
487 sftp_pkt_getstring(pktin, &hstring, &len);
489 fxp_internal_error("OPENDIR returned malformed FXP_HANDLE\n");
490 sftp_pkt_free(pktin);
493 handle = smalloc(sizeof(struct fxp_handle));
494 handle->hstring = mkstr(hstring, len);
496 sftp_pkt_free(pktin);
499 fxp_got_status(pktin);
500 sftp_pkt_free(pktin);
508 void fxp_close(struct fxp_handle *handle)
510 struct sftp_packet *pktin, *pktout;
513 pktout = sftp_pkt_init(SSH_FXP_CLOSE);
514 sftp_pkt_adduint32(pktout, 0x789); /* request id */
515 sftp_pkt_addstring_start(pktout);
516 sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
520 fxp_internal_error("did not receive a valid SFTP packet\n");
523 id = sftp_pkt_getuint32(pktin);
525 fxp_internal_error("request ID mismatch\n");
526 sftp_pkt_free(pktin);
529 fxp_got_status(pktin);
530 sftp_pkt_free(pktin);
531 sfree(handle->hstring);
535 int fxp_mkdir(char *path)
537 struct sftp_packet *pktin, *pktout;
540 pktout = sftp_pkt_init(SSH_FXP_MKDIR);
541 sftp_pkt_adduint32(pktout, 0x234); /* request id */
542 sftp_pkt_addstring(pktout, path);
543 sftp_pkt_adduint32(pktout, 0); /* (FIXME) empty ATTRS structure */
547 fxp_internal_error("did not receive a valid SFTP packet\n");
550 id = sftp_pkt_getuint32(pktin);
552 fxp_internal_error("request ID mismatch\n");
553 sftp_pkt_free(pktin);
556 id = fxp_got_status(pktin);
557 sftp_pkt_free(pktin);
564 int fxp_rmdir(char *path)
566 struct sftp_packet *pktin, *pktout;
569 pktout = sftp_pkt_init(SSH_FXP_RMDIR);
570 sftp_pkt_adduint32(pktout, 0x345); /* request id */
571 sftp_pkt_addstring(pktout, path);
575 fxp_internal_error("did not receive a valid SFTP packet\n");
578 id = sftp_pkt_getuint32(pktin);
580 fxp_internal_error("request ID mismatch\n");
581 sftp_pkt_free(pktin);
584 id = fxp_got_status(pktin);
585 sftp_pkt_free(pktin);
592 int fxp_remove(char *fname)
594 struct sftp_packet *pktin, *pktout;
597 pktout = sftp_pkt_init(SSH_FXP_REMOVE);
598 sftp_pkt_adduint32(pktout, 0x678); /* request id */
599 sftp_pkt_addstring(pktout, fname);
603 fxp_internal_error("did not receive a valid SFTP packet\n");
606 id = sftp_pkt_getuint32(pktin);
608 fxp_internal_error("request ID mismatch\n");
609 sftp_pkt_free(pktin);
612 id = fxp_got_status(pktin);
613 sftp_pkt_free(pktin);
620 int fxp_rename(char *srcfname, char *dstfname)
622 struct sftp_packet *pktin, *pktout;
625 pktout = sftp_pkt_init(SSH_FXP_RENAME);
626 sftp_pkt_adduint32(pktout, 0x678); /* request id */
627 sftp_pkt_addstring(pktout, srcfname);
628 sftp_pkt_addstring(pktout, dstfname);
632 fxp_internal_error("did not receive a valid SFTP packet\n");
635 id = sftp_pkt_getuint32(pktin);
637 fxp_internal_error("request ID mismatch\n");
638 sftp_pkt_free(pktin);
641 id = fxp_got_status(pktin);
642 sftp_pkt_free(pktin);
650 * Retrieve the attributes of a file. We have fxp_stat which works
651 * on filenames, and fxp_fstat which works on open file handles.
653 int fxp_stat(char *fname, struct fxp_attrs *attrs)
655 struct sftp_packet *pktin, *pktout;
658 pktout = sftp_pkt_init(SSH_FXP_STAT);
659 sftp_pkt_adduint32(pktout, 0x678); /* request id */
660 sftp_pkt_addstring(pktout, fname);
664 fxp_internal_error("did not receive a valid SFTP packet\n");
667 id = sftp_pkt_getuint32(pktin);
669 fxp_internal_error("request ID mismatch\n");
670 sftp_pkt_free(pktin);
674 if (pktin->type == SSH_FXP_ATTRS) {
675 *attrs = sftp_pkt_getattrs(pktin);
676 sftp_pkt_free(pktin);
679 fxp_got_status(pktin);
680 sftp_pkt_free(pktin);
685 int fxp_fstat(struct fxp_handle *handle, struct fxp_attrs *attrs)
687 struct sftp_packet *pktin, *pktout;
690 pktout = sftp_pkt_init(SSH_FXP_FSTAT);
691 sftp_pkt_adduint32(pktout, 0x678); /* request id */
692 sftp_pkt_addstring_start(pktout);
693 sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
697 fxp_internal_error("did not receive a valid SFTP packet\n");
700 id = sftp_pkt_getuint32(pktin);
702 fxp_internal_error("request ID mismatch\n");
703 sftp_pkt_free(pktin);
707 if (pktin->type == SSH_FXP_ATTRS) {
708 *attrs = sftp_pkt_getattrs(pktin);
709 sftp_pkt_free(pktin);
712 fxp_got_status(pktin);
713 sftp_pkt_free(pktin);
719 * Set the attributes of a file.
721 int fxp_setstat(char *fname, struct fxp_attrs attrs)
723 struct sftp_packet *pktin, *pktout;
726 pktout = sftp_pkt_init(SSH_FXP_SETSTAT);
727 sftp_pkt_adduint32(pktout, 0x678); /* request id */
728 sftp_pkt_addstring(pktout, fname);
729 sftp_pkt_addattrs(pktout, attrs);
733 fxp_internal_error("did not receive a valid SFTP packet\n");
736 id = sftp_pkt_getuint32(pktin);
738 fxp_internal_error("request ID mismatch\n");
739 sftp_pkt_free(pktin);
742 id = fxp_got_status(pktin);
743 sftp_pkt_free(pktin);
749 int fxp_fsetstat(struct fxp_handle *handle, struct fxp_attrs attrs)
751 struct sftp_packet *pktin, *pktout;
754 pktout = sftp_pkt_init(SSH_FXP_FSETSTAT);
755 sftp_pkt_adduint32(pktout, 0x678); /* request id */
756 sftp_pkt_addstring_start(pktout);
757 sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
758 sftp_pkt_addattrs(pktout, attrs);
762 fxp_internal_error("did not receive a valid SFTP packet\n");
765 id = sftp_pkt_getuint32(pktin);
767 fxp_internal_error("request ID mismatch\n");
768 sftp_pkt_free(pktin);
771 id = fxp_got_status(pktin);
772 sftp_pkt_free(pktin);
780 * Read from a file. Returns the number of bytes read, or -1 on an
781 * error, or possibly 0 if EOF. (I'm not entirely sure whether it
782 * will return 0 on EOF, or return -1 and store SSH_FX_EOF in the
783 * error indicator. It might even depend on the SFTP server.)
785 int fxp_read(struct fxp_handle *handle, char *buffer, uint64 offset,
788 struct sftp_packet *pktin, *pktout;
791 pktout = sftp_pkt_init(SSH_FXP_READ);
792 sftp_pkt_adduint32(pktout, 0xBCD); /* request id */
793 sftp_pkt_addstring_start(pktout);
794 sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
795 sftp_pkt_adduint64(pktout, offset);
796 sftp_pkt_adduint32(pktout, len);
800 fxp_internal_error("did not receive a valid SFTP packet\n");
803 id = sftp_pkt_getuint32(pktin);
805 fxp_internal_error("request ID mismatch");
806 sftp_pkt_free(pktin);
809 if (pktin->type == SSH_FXP_DATA) {
813 sftp_pkt_getstring(pktin, &str, &rlen);
815 if (rlen > len || rlen < 0) {
816 fxp_internal_error("READ returned more bytes than requested");
817 sftp_pkt_free(pktin);
821 memcpy(buffer, str, rlen);
822 sftp_pkt_free(pktin);
825 fxp_got_status(pktin);
826 sftp_pkt_free(pktin);
832 * Read from a directory.
834 struct fxp_names *fxp_readdir(struct fxp_handle *handle)
836 struct sftp_packet *pktin, *pktout;
839 pktout = sftp_pkt_init(SSH_FXP_READDIR);
840 sftp_pkt_adduint32(pktout, 0xABC); /* request id */
841 sftp_pkt_addstring_start(pktout);
842 sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
846 fxp_internal_error("did not receive a valid SFTP packet\n");
849 id = sftp_pkt_getuint32(pktin);
851 fxp_internal_error("request ID mismatch\n");
852 sftp_pkt_free(pktin);
855 if (pktin->type == SSH_FXP_NAME) {
856 struct fxp_names *ret;
858 ret = smalloc(sizeof(struct fxp_names));
859 ret->nnames = sftp_pkt_getuint32(pktin);
860 ret->names = smalloc(ret->nnames * sizeof(struct fxp_name));
861 for (i = 0; i < ret->nnames; i++) {
864 sftp_pkt_getstring(pktin, &str, &len);
865 ret->names[i].filename = mkstr(str, len);
866 sftp_pkt_getstring(pktin, &str, &len);
867 ret->names[i].longname = mkstr(str, len);
868 ret->names[i].attrs = sftp_pkt_getattrs(pktin);
870 sftp_pkt_free(pktin);
873 fxp_got_status(pktin);
874 sftp_pkt_free(pktin);
880 * Write to a file. Returns 0 on error, 1 on OK.
882 int fxp_write(struct fxp_handle *handle, char *buffer, uint64 offset,
885 struct sftp_packet *pktin, *pktout;
888 pktout = sftp_pkt_init(SSH_FXP_WRITE);
889 sftp_pkt_adduint32(pktout, 0xDCB); /* request id */
890 sftp_pkt_addstring_start(pktout);
891 sftp_pkt_addstring_data(pktout, handle->hstring, handle->hlen);
892 sftp_pkt_adduint64(pktout, offset);
893 sftp_pkt_addstring_start(pktout);
894 sftp_pkt_addstring_data(pktout, buffer, len);
898 fxp_internal_error("did not receive a valid SFTP packet\n");
901 id = sftp_pkt_getuint32(pktin);
903 fxp_internal_error("request ID mismatch\n");
904 sftp_pkt_free(pktin);
907 fxp_got_status(pktin);
908 sftp_pkt_free(pktin);
909 return fxp_errtype == SSH_FX_OK;
913 * Free up an fxp_names structure.
915 void fxp_free_names(struct fxp_names *names)
919 for (i = 0; i < names->nnames; i++) {
920 sfree(names->names[i].filename);
921 sfree(names->names[i].longname);
928 * Duplicate an fxp_name structure.
930 struct fxp_name *fxp_dup_name(struct fxp_name *name)
932 struct fxp_name *ret;
933 ret = smalloc(sizeof(struct fxp_name));
934 ret->filename = dupstr(name->filename);
935 ret->longname = dupstr(name->longname);
936 ret->attrs = name->attrs; /* structure copy */
941 * Free up an fxp_name structure.
943 void fxp_free_name(struct fxp_name *name)
945 sfree(name->filename);
946 sfree(name->longname);