Hi all,

I would like to use CURLOPT_RANGE with an SFTP download, but it's not
currently supported. However, looking at
http://tools.ietf.org/html/draft-ietf-secsh-filexfer-13#page-36
I saw that the protocol supports it, so I've tried to add support.

The patch below makes curl start downloading from the right byte, so I'm
half way there. Unfortunately, due to unfamiliarity with the code, I
haven't managed the other half yet, and I don't have any more time to work on
this at the moment. Presumably all that is needed is to tell curl how
many bytes to download, somehow. I'd be delighted if someone was able to
finish this off, or give me some clues on how to do so myself.

The patch is against Debian's 7.18.2 as that's what I had handy, but I
hope it'll work equally well in the CVS code.

diff -ur old/curl-7.18.2/lib/ssh.c new/curl-7.18.2/lib/ssh.c
--- old/curl-7.18.2/lib/ssh.c 2008-05-31 07:15:01.000000000 +0100
+++ new/curl-7.18.2/lib/ssh.c 2008-09-12 01:34:47.000000000 +0100
@@ -104,6 +104,7 @@
 #include "select.h"
 #include "parsedate.h" /* for the week day and month names */
 #include "sockaddr.h" /* required for Curl_sockaddr_storage */
+#include "strtoofft.h"
 #include "multiif.h"

 #if defined(HAVE_INET_NTOA_R) && !defined(HAVE_INET_NTOA_R_DECL)
@@ -2306,6 +2307,20 @@
   }
   *connected = conn->bits.tcpconnect;
 
+ if(conn->data->state.use_range) {
+ curl_off_t from, to;
+ char *ptr;
+ char *ptr2;
+
+ /* XXX This needs to look for from/to being missing */
+ from=curlx_strtoofft(conn->data->state.range, &ptr, 0);
+ while(ptr && *ptr && (isspace((int)*ptr) || (*ptr=='-')))
+ ptr++;
+ to=curlx_strtoofft(ptr, &ptr2, 0);
+
+ libssh2_sftp_seek(conn->proto.sshc.sftp_handle, from);
+ }
+
   if(*dophase_done) {
     DEBUGF(infof(conn->data, "DO phase is complete\n"));
   }

Thanks
Ian
Received on 2008-09-12