2019-kvm-forum/papers/NBD-changes.tex

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  22
  23 \title{Summary of changes in NBD-related projects since mid 2016}
  24
  25 \begin{document}
  26 \maketitle
  27
  28 \section{NBD protocol}
  29 \url{https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md}
  30
  31 \begin{description}
  32 \item[2016]
  33
  34 \verb|WRITE_ZEROES|
  35
  36 \verb|NBD_OPT_INFO| and \verb|NBD_OPT_GO| (finalized)
  37
  38 TLS support (finalized)
  39
  40 \verb|NBD_OPT_BLOCK_SIZE|
  41
  42 \verb|NBD_FLAG_CAN_MULTI_CONN|
  43
  44 \item[2017]
  45
  46 \verb|STRUCTURED_REPLY| merged
  47
  48 \item[2018]
  49
  50 \verb|NBD_CMD_BLOCK_STATUS|, metadata contexts, \verb|base:|
  51 namespace, etc. merged
  52
  53 Preferred block size specified as 512 bytes.  Document maximum
  54 request size limits.
  55
  56 \verb|NBD_CMD_CACHE|
  57
  58 \item[2019]
  59
  60 \verb|NBD_CMD_FLAG_FAST_ZERO|
  61
  62 Recommend use of \verb|TCP_NODELAY|
  63
  64 \end{description}
  65
  66 \subsection{URIs}
  67
  68 \begin{description}
  69 \item[2019]
  70 NBD URI specification was introduced.
  71 \url{https://github.com/NetworkBlockDevice/nbd/blob/master/doc/uri.md}
  72 \end{description}
  73
  74
  75 \f
  76 \section{qemu-nbd}
  77
  78
  79
  80 \f
  81 \section{nbdkit}
  82
  83
  84 \f
  85 \section{libnbd}
  86
  87 Project started last day of April 2019.
  88
  89 \begin{description}
  90
  91 \item[May 2019]
  92
  93 Most \verb|NBD_CMD_| implemented, and working connection to nbdkit,
  94 within first 10 days.  Interoperating with qemu-nbd within 2 weeks.
  95 TLS implemented and interoperating with qemu-nbd within 16 days.
  96
  97 Generated C API, Python 3 bindings and \verb|nbdsh|, OCaml bindings,
  98 hierarchical state machine.
  99
 100 Export names
 101
 102 Subprocess server (\verb|nbd_connect_command|)
 103
 104 Structured replies
 105
 106 \verb|NBD_CMD_BLOCK_STATUS| and \verb|base:allocation|
 107
 108 Multiple commands ready to issue and in flight
 109
 110 Callbacks
 111
 112 ``Internal'' multi-conn support added then removed
 113
 114 Valgrinding
 115
 116 Some API calls can be handled without taking the lock
 117
 118 libnbd $0.1.2$ was released on May $30^{th}$ 2019.
 119
 120 \item[June 2019]
 121
 122 NBD URIs supported
 123
 124 \verb|nbdsh -c| parameter
 125
 126 \verb|MSG_MORE| optimization
 127
 128 Better handling of multiple in-flight commands, a lot of
 129 optimization, and finessing of the API.
 130
 131 Python bindings custom exception \verb|nbd.Error|
 132
 133 \item[July 2019]
 134
 135 Port to FreeBSD
 136
 137 Further work on callbacks
 138
 139 Optimize command queue to be $O(1)$ instead of $O(n)$
 140
 141 Symbol versions
 142
 143 libnbd $0.9.6$ was released on Jul $30^{th}$ 2019.
 144
 145 \item[August 2019]
 146
 147 More tests
 148
 149 Debug output includes function names, parameters, return values
 150
 151 Optional function parameters
 152
 153 Man pages for every API
 154
 155 Port to RHEL 7
 156
 157 First stable version $1.0$ was released on August $27^{th}$ 2019.
 158
 159 \item[September 2019]
 160
 161 Support for \verb|FAST_ZERO|
 162
 163 New APIs for testing servers without Structured Replies and explicitly
 164 setting handshake flags.  New APIs for finding out if TLS was
 165 negotiated, and what NBD protocol is being used.
 166
 167 Reproducible build
 168
 169 Two CVEs found
 170
 171 Share \verb|nbd-protocol.h| file with nbdkit
 172
 173 \item[October 2019]
 174
 175 Systemd socket activation
 176
 177 Fuzz testing (discovers one serious CVE)
 178
 179 New API to connect directly to socket
 180
 181 New \verb|nbdfuse| tool
 182
 183 \end{description}
 184
 185 \end{document}