#include <stdlib.h>
#include <string.h>
#include <assert.h>
+#include <limits.h>
#include "misc.h"
#include "int64.h"
struct sftp_request {
unsigned id;
int registered;
+ void *userdata;
};
static int sftp_reqcmp(void *av, void *bv)
r = snew(struct sftp_request);
r->id = low + 1 + REQUEST_ID_OFFSET;
r->registered = 0;
+ r->userdata = NULL;
add234(sftp_requests, r);
return r;
}
sfree(name->longname);
sfree(name);
}
+
+/*
+ * Store user data in an sftp_request structure.
+ */
+void *fxp_get_userdata(struct sftp_request *req)
+{
+ return req->userdata;
+}
+
+void fxp_set_userdata(struct sftp_request *req, void *data)
+{
+ req->userdata = data;
+}
+
+/*
+ * A wrapper to go round fxp_read_* and fxp_write_*, which manages
+ * the queueing of multiple read/write requests.
+ */
+
+struct req {
+ char *buffer;
+ int len, retlen, complete;
+ uint64 offset;
+ struct req *next, *prev;
+};
+
+struct fxp_xfer {
+ uint64 offset, furthestdata, filesize;
+ int nreqs, req_max, eof, err;
+ struct fxp_handle *fh;
+ struct req *head, *tail;
+};
+
+static struct fxp_xfer *xfer_init(struct fxp_handle *fh, uint64 offset)
+{
+ struct fxp_xfer *xfer = snew(struct fxp_xfer);
+
+ xfer->fh = fh;
+ xfer->offset = offset;
+ xfer->head = xfer->tail = NULL;
+ xfer->nreqs = 0;
+ xfer->req_max = 4; /* FIXME: set properly! */
+ xfer->err = 0;
+ xfer->filesize = uint64_make(ULONG_MAX, ULONG_MAX);
+ xfer->furthestdata = uint64_make(0, 0);
+
+ return xfer;
+}
+
+int xfer_download_done(struct fxp_xfer *xfer)
+{
+ /*
+ * We're finished if we've seen EOF _and_ there are no
+ * outstanding requests.
+ */
+ return (xfer->eof || xfer->err) && !xfer->head;
+}
+
+void xfer_download_queue(struct fxp_xfer *xfer)
+{
+ while (xfer->nreqs < xfer->req_max && !xfer->eof) {
+ /*
+ * Queue a new read request.
+ */
+ struct req *rr;
+ struct sftp_request *req;
+
+ rr = snew(struct req);
+ rr->offset = xfer->offset;
+ rr->complete = 0;
+ if (xfer->tail) {
+ xfer->tail->next = rr;
+ rr->prev = xfer->tail;
+ } else {
+ xfer->head = rr;
+ rr->prev = NULL;
+ }
+ xfer->tail = rr;
+ rr->next = NULL;
+
+ rr->len = 4096;
+ rr->buffer = snewn(rr->len, char);
+ sftp_register(req = fxp_read_send(xfer->fh, rr->offset, rr->len));
+ fxp_set_userdata(req, rr);
+
+ xfer->offset = uint64_add32(xfer->offset, rr->len);
+ xfer->nreqs++;
+
+#ifdef DEBUG_DOWNLOAD
+ { char buf[40]; uint64_decimal(rr->offset, buf); printf("queueing read request %p at %s\n", rr, buf); }
+#endif
+ }
+}
+
+struct fxp_xfer *xfer_download_init(struct fxp_handle *fh, uint64 offset)
+{
+ struct fxp_xfer *xfer = xfer_init(fh, offset);
+
+ xfer->eof = FALSE;
+ xfer_download_queue(xfer);
+
+ return xfer;
+}
+
+int xfer_download_gotpkt(struct fxp_xfer *xfer, struct sftp_packet *pktin)
+{
+ struct sftp_request *rreq;
+ struct req *rr;
+
+ rreq = sftp_find_request(pktin);
+ rr = (struct req *)fxp_get_userdata(rreq);
+ if (!rr)
+ return 0; /* this packet isn't ours */
+ rr->retlen = fxp_read_recv(pktin, rreq, rr->buffer, rr->len);
+#ifdef DEBUG_DOWNLOAD
+ printf("read request %p has returned [%d]\n", rr, rr->retlen);
+#endif
+
+ if ((rr->retlen < 0 && fxp_error_type()==SSH_FX_EOF) || rr->retlen == 0) {
+ xfer->eof = TRUE;
+ rr->complete = -1;
+#ifdef DEBUG_DOWNLOAD
+ printf("setting eof\n");
+#endif
+ } else if (rr->retlen < 0) {
+ /* some error other than EOF; signal it back to caller */
+ return -1;
+ }
+
+ rr->complete = 1;
+
+ /*
+ * Special case: if we have received fewer bytes than we
+ * actually read, we should do something. For the moment I'll
+ * just throw an ersatz FXP error to signal this; the SFTP
+ * draft I've got says that it can't happen except on special
+ * files, in which case seeking probably has very little
+ * meaning and so queueing an additional read request to fill
+ * up the gap sounds like the wrong answer. I'm not sure what I
+ * should be doing here - if it _was_ a special file, I suspect
+ * I simply shouldn't have been queueing multiple requests in
+ * the first place...
+ */
+ if (rr->retlen > 0 && uint64_compare(xfer->furthestdata, rr->offset) < 0) {
+ xfer->furthestdata = rr->offset;
+#ifdef DEBUG_DOWNLOAD
+ { char buf[40];
+ uint64_decimal(xfer->furthestdata, buf);
+ printf("setting furthestdata = %s\n", buf); }
+#endif
+ }
+
+ if (rr->retlen < rr->len) {
+ uint64 filesize = uint64_add32(rr->offset,
+ (rr->retlen < 0 ? 0 : rr->retlen));
+#ifdef DEBUG_DOWNLOAD
+ { char buf[40];
+ uint64_decimal(filesize, buf);
+ printf("short block! trying filesize = %s\n", buf); }
+#endif
+ if (uint64_compare(xfer->filesize, filesize) > 0) {
+ xfer->filesize = filesize;
+#ifdef DEBUG_DOWNLOAD
+ printf("actually changing filesize\n");
+#endif
+ }
+ }
+
+ if (uint64_compare(xfer->furthestdata, xfer->filesize) > 0) {
+ fxp_error_message = "received a short buffer from FXP_READ, but not"
+ " at EOF";
+ fxp_errtype = -1;
+ xfer_set_error(xfer);
+ return -1;
+ }
+
+ return 1;
+}
+
+void xfer_set_error(struct fxp_xfer *xfer)
+{
+ xfer->err = 1;
+}
+
+int xfer_download_data(struct fxp_xfer *xfer, void **buf, int *len)
+{
+ void *retbuf = NULL;
+ int retlen = 0;
+
+ /*
+ * Discard anything at the head of the rr queue with complete <
+ * 0; return the first thing with complete > 0.
+ */
+ while (xfer->head && xfer->head->complete && !retbuf) {
+ struct req *rr = xfer->head;
+
+ if (rr->complete > 0) {
+ retbuf = rr->buffer;
+ retlen = rr->retlen;
+#ifdef DEBUG_DOWNLOAD
+ printf("handing back data from read request %p\n", rr);
+#endif
+ }
+#ifdef DEBUG_DOWNLOAD
+ else
+ printf("skipping failed read request %p\n", rr);
+#endif
+
+ xfer->head = xfer->head->next;
+ if (xfer->head)
+ xfer->head->prev = NULL;
+ else
+ xfer->tail = NULL;
+ sfree(rr);
+ xfer->nreqs--;
+ }
+
+ if (retbuf) {
+ *buf = retbuf;
+ *len = retlen;
+ return 1;
+ } else
+ return 0;
+}
+
+void xfer_cleanup(struct fxp_xfer *xfer)
+{
+ struct req *rr;
+ while (xfer->head) {
+ rr = xfer->head;
+ xfer->head = xfer->head->next;
+ sfree(rr->buffer);
+ sfree(rr);
+ }
+ sfree(xfer);
+}
projects / u / mdw / putty / blobdiff