On Wed, Aug 02, 2023 at 08:50:36PM -0500, Eric Blake wrote:
> Add another bit of overall server information, as well as a '--has
> extended-headers' silent query. For now, the testsuite is written
> assuming that when nbdkit finally adds extended headers support, it
> will also add a --no-eh kill switch comparable to its existing --no-sr
> switch.
>
> Signed-off-by: Eric Blake <ebl...@redhat.com>
> ---
>
> v4: s/can/has/ [Rich]
> ---
> info/nbdinfo.pod | 9 +++++++++
> info/can.c | 9 +++++++++
> info/info-can.sh | 27 +++++++++++++++++++++++++++
> info/info-packets.sh | 17 ++++++++++++++++-
> info/main.c | 7 ++++++-
> 5 files changed, 67 insertions(+), 2 deletions(-)
>
> diff --git a/info/nbdinfo.pod b/info/nbdinfo.pod
> index 72193c24..2bdd573f 100644
> --- a/info/nbdinfo.pod
> +++ b/info/nbdinfo.pod
> @@ -86,6 +86,7 @@ the I<--json> parameter:
> "protocol": "newstyle-fixed",
> "TLS": false,
> "structured": true,
> + "extended": false,
> "exports": [
> {
> "export-name": "",
> @@ -165,6 +166,11 @@ Test if the NBD URI connection is using TLS.
> Test if server has support for structured replies (a prerequisite
> for supporting block status commands).
>
> +=item nbdinfo --has extended-headers URI
> +
> +Test if server supports extended headers (a prerequisite for
> +supporting 64-bit commands; implies structured replies as well).
> +
> =item nbdinfo --is rotational URI
>
> Test if the server export is backed by something which behaves like a
> @@ -367,6 +373,8 @@ When using I<--list>, the default is I<--no-content>
> (since
> downloading from each export is expensive). To enable content probing
> use I<--list --content>.
>
> +=item B<--has extended-headers>
> +
> =item B<--has structured-reply>
>
> Test properties of the NBD server connection. The command does not
> @@ -377,6 +385,7 @@ indicate an error querying the flag).
> For further information see the L<NBD
> protocol|https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md>
> and the following libnbd functions:
> +L<nbd_get_extended_headers_negotiated(3)>,
> L<nbd_get_structured_replies_negotiated(3)>.
>
> =item B<--is read-only>
> diff --git a/info/can.c b/info/can.c
> index 8514fd5a..8547ef04 100644
> --- a/info/can.c
> +++ b/info/can.c
> @@ -50,6 +50,15 @@ do_can (void)
> strcasecmp (can, "structured_replies") == 0)
> feature = nbd_get_structured_replies_negotiated (nbd);
>
> + else if (strcasecmp (can, "eh") == 0 ||
> + strcasecmp (can, "extended header") == 0 ||
> + strcasecmp (can, "extended-header") == 0 ||
> + strcasecmp (can, "extended_header") == 0 ||
> + strcasecmp (can, "extended headers") == 0 ||
> + strcasecmp (can, "extended-headers") == 0 ||
> + strcasecmp (can, "extended_headers") == 0)
> + feature = nbd_get_extended_headers_negotiated (nbd);
> +
> else if (strcasecmp (can, "readonly") == 0 ||
> strcasecmp (can, "read-only") == 0 ||
> strcasecmp (can, "read_only") == 0)
> diff --git a/info/info-can.sh b/info/info-can.sh
> index 13ef1032..5d9f2e89 100755
> --- a/info/info-can.sh
> +++ b/info/info-can.sh
> @@ -61,6 +61,33 @@ esac
> EOF
> test $st = 2
>
> +# --has extended-headers cannot be positively tested until nbdkit gains
> +# --no-eh support. Otherwise, it is similar to --has structured-reply.
> +
> +no_eh=
> +if nbdkit --no-eh --help >/dev/null 2>/dev/null; then
> + no_eh=--no-eh
> + nbdkit -v -U - sh - \
> + --run '$VG nbdinfo --has extended-headers
> "nbd+unix:///?socket=$unixsocket"' <<'EOF'
> +case "$1" in
> + get_size) echo 1024 ;;
> + pread) ;;
> + *) exit 2 ;;
> +esac
> +EOF
> +fi
> +
> +st=0
> +nbdkit -v -U - $no_eh sh - \
> + --run '$VG nbdinfo --has extended-headers
> "nbd+unix:///?socket=$unixsocket"' <<'EOF' || st=$?
> +case "$1" in
> + get_size) echo 1024 ;;
> + pread) ;;
> + *) exit 2 ;;
> +esac
> +EOF
> +test $st = 2
> +
> # --can cache and --can fua require special handling because in
> # nbdkit-sh-plugin we must print "native" or "none". Also the can_fua
> # flag is only sent if the export is writable (hence can_write below).
> diff --git a/info/info-packets.sh b/info/info-packets.sh
> index 2460052e..410faef8 100755
> --- a/info/info-packets.sh
> +++ b/info/info-packets.sh
> @@ -27,12 +27,27 @@ requires nbdkit --no-sr memory --version
> out=info-packets.out
> cleanup_fn rm -f $out
>
> +# Older nbdkit does not support extended headers; --no-eh is a reliable
> +# witness of whether nbdkit is new enough.
> +
> +no_eh=
> +if nbdkit --no-eh --help >/dev/null 2>/dev/null; then
> + no_eh=--no-eh
> +fi
> +
> nbdkit --no-sr -U - memory size=1M \
> --run '$VG nbdinfo "nbd+unix:///?socket=$unixsocket"' > $out
> cat $out
> grep "protocol: .*using simple packets" $out
>
> -nbdkit -U - memory size=1M \
> +nbdkit $no_eh -U - memory size=1M \
> --run '$VG nbdinfo "nbd+unix:///?socket=$unixsocket"' > $out
> cat $out
> grep "protocol: .*using structured packets" $out
> +
> +if test x != "x$no_eh"; then
> + nbdkit -U - memory size=1M \
> + --run '$VG nbdinfo "nbd+unix:///?socket=$unixsocket"' > $out
> + cat $out
> + grep "protocol: .*using extended packets" $out
> +fi
> diff --git a/info/main.c b/info/main.c
> index dbcc5a14..572dd536 100644
> --- a/info/main.c
> +++ b/info/main.c
> @@ -306,11 +306,13 @@ main (int argc, char *argv[])
> const char *protocol;
> int tls_negotiated;
> int sr_negotiated;
> + int eh_negotiated;
>
> /* Print per-connection fields. */
> protocol = nbd_get_protocol (nbd);
> tls_negotiated = nbd_get_tls_negotiated (nbd);
> sr_negotiated = nbd_get_structured_replies_negotiated (nbd);
> + eh_negotiated = nbd_get_extended_headers_negotiated (nbd);
>
> if (!json_output) {
> if (protocol) {
> @@ -318,8 +320,9 @@ main (int argc, char *argv[])
> fprintf (fp, "protocol: %s", protocol);
> if (tls_negotiated >= 0)
> fprintf (fp, " %s TLS", tls_negotiated ? "with" : "without");
> - if (sr_negotiated >= 0)
> + if (eh_negotiated >= 0 && sr_negotiated >= 0)
> fprintf (fp, ", using %s packets",
> + eh_negotiated ? "extended" :
> sr_negotiated ? "structured" : "simple");
Interesting - there's never a case where we could have extended
headers && ! structured replies?
> fprintf (fp, "\n");
> ansi_restore (fp);
> @@ -337,6 +340,8 @@ main (int argc, char *argv[])
> fprintf (fp, "\"TLS\": %s,\n", tls_negotiated ? "true" : "false");
> if (sr_negotiated >= 0)
> fprintf (fp, "\"structured\": %s,\n", sr_negotiated ? "true" :
> "false");
> + if (eh_negotiated >= 0)
> + fprintf (fp, "\"extended\": %s,\n", eh_negotiated ? "true" :
> "false");
> }
>
> if (!list_all)
> --
Reviewed-by: Richard W.M. Jones <rjo...@redhat.com>
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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