[tahoe-lafs-trac-stream] [Tahoe-LAFS] #3907: HTTP storage protocol should not support requests beyond the end of the share

[Tahoe-LAFS]

#3907: HTTP storage protocol should not support requests beyond the end  of the
share
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 Reporter:  itamarst  |          Owner:
     Type:  defect    |         Status:  new
 Priority:  normal    |      Milestone:  HTTP Storage Protocol
Component:  unknown   |        Version:  n/a
 Keywords:            |  Launchpad Bug:
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 Currently requests beyond the end of the share result in truncated result.
 This is a weird thing to do from an HTTP perspective, and I suspect is
 only done because Foolscap maps directly to function calls; more
 structured information in a HTTP response ought to make it unnecessary.
 So:

 1. The HTTP protocol will not support this; reading beyond the end will
 result in HTTP error.
 2. The HTTP protocol will grow HEAD endpoints for mutable and immutables
 shares to get their length.
 3. Given the length of a share, the `IStorageServer` emulation layer can
 emulate this behavior by truncating requests to the actual length of the
 share. If a mutable is written half-way this in theory can result in
 error, but oh well.

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Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3907>
Tahoe-LAFS <https://Tahoe-LAFS.org>
secure decentralized storage