[Libguestfs] [nbdkit PATCH v2 5/8] sh, eval: Implement .default_export

Use the recently added nbdkit_strndup_intern to make this possible. Testsuite coverage is added in both tls-fallback as well as a cleanup to test-eval-exports.sh. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- plugins/eval/nbdkit-eval-plugin.pod | 2 ++ plugins/sh/nbdkit-sh-plugin.pod | 20 +++++++++++-- plugins/sh/methods.h | 1 + plugins/eval/eval.c | 2 ++ plugins/sh/methods.c | 45 ++++++++++++++++++++++++++++- plugins/sh/sh.c | 1 + plugins/sh/example.sh | 2 +- tests/test-eval-exports.sh | 35 ++++++++++++++-------- tests/test-export-info.sh | 7 ++--- tests/test-tls-fallback.sh | 11 ++++--- 10 files changed, 102 insertions(+), 24 deletions(-) diff --git a/plugins/eval/nbdkit-eval-plugin.pod b/plugins/eval/nbdkit-eval-plugin.pod index baf79adf..eb3c7f5a 100644 --- a/plugins/eval/nbdkit-eval-plugin.pod +++ b/plugins/eval/nbdkit-eval-plugin.pod @@ -112,6 +112,8 @@ features): =item B<list_exports=>SCRIPT +=item B<default_export=>SCRIPT + =item B<open=>SCRIPT =item B<pread=>SCRIPT diff --git a/plugins/sh/nbdkit-sh-plugin.pod b/plugins/sh/nbdkit-sh-plugin.pod index 07d90b57..b827b658 100644 --- a/plugins/sh/nbdkit-sh-plugin.pod +++ b/plugins/sh/nbdkit-sh-plugin.pod @@ -315,8 +315,24 @@ export name or description, although this could be possible under a new mode supporting escape sequences. This method is I<not> required; if it is absent, the list of exports -advertised by nbdkit will be the single export with the empty string -as a name and no description. +advertised by nbdkit will be the single name result of C<default_export> +and no description. + +=item C<default_export> + + /path/to/script default_export <readonly> <tls> + +The C<readonly> and C<tls> parameters will be C<true> or C<false>. + +On success this should print a name on stdout to use in place of the +default export C<"">, then exit with code C<0>. For convenience, the +output can be any of the list forms recognized by C<list_exports>, in +which case the first listed export name is used, and where an empty +list uses C<"">. Given the current set of recognized export lists, it +is not possible for the resulting name to include a newline. + +This method is I<not> required; if it is absent, the default export +name will be the empty string, C<"">. =item C<open> diff --git a/plugins/sh/methods.h b/plugins/sh/methods.h index 69017fa4..3fd4ef42 100644 --- a/plugins/sh/methods.h +++ b/plugins/sh/methods.h @@ -46,6 +46,7 @@ extern int sh_after_fork (void); extern int sh_preconnect (int readonly); extern int sh_list_exports (int readonly, int default_only, struct nbdkit_exports *exports); +extern const char *sh_default_export (int readonly, int is_tls); extern void *sh_open (int readonly); extern void sh_close (void *handle); extern int64_t sh_get_size (void *handle); diff --git a/plugins/eval/eval.c b/plugins/eval/eval.c index 2bd5e79f..a123734e 100644 --- a/plugins/eval/eval.c +++ b/plugins/eval/eval.c @@ -68,6 +68,7 @@ static const char *known_methods[] = { "close", "config", "config_complete", + "default_export", "dump_plugin", "extents", "flush", @@ -395,6 +396,7 @@ static struct nbdkit_plugin plugin = { .preconnect = sh_preconnect, .list_exports = sh_list_exports, + .default_export = sh_default_export, .open = sh_open, .close = sh_close, diff --git a/plugins/sh/methods.c b/plugins/sh/methods.c index 2192ae25..55d6d535 100644 --- a/plugins/sh/methods.c +++ b/plugins/sh/methods.c @@ -241,7 +241,9 @@ parse_exports (const char *script, { const char *n, *d, *p, *q; - /* The first line determines how to parse the rest of s */ + /* The first line determines how to parse the rest of s. Keep + * sh_default_export in sync with this. + */ if ((p = skip_prefix (s, "INTERLEAVED\n")) != NULL) { n = p; while ((d = strchr (n, '\n')) != NULL) { @@ -331,6 +333,47 @@ sh_list_exports (int readonly, int default_only, } } +const char * +sh_default_export (int readonly, int is_tls) +{ + const char *method = "default_export"; + const char *script = get_script (method); + const char *args[] = { script, method, readonly ? "true" : "false", + is_tls ? "true" : "false", NULL }; + CLEANUP_FREE char *s = NULL; + size_t slen; + const char *p, *n; + + switch (call_read (&s, &slen, args)) { + case OK: + /* The first line determines how to parse the rest of s. For now, + * all export modes treat the next line as the first export. + */ + if ((p = skip_prefix (s, "INTERLEAVED\n")) != NULL || + (p = skip_prefix (s, "NAMES+DESCRIPTIONS\n")) != NULL || + (p = skip_prefix (s, "NAMES\n")) != NULL) + ; + else + p = s; + n = strchr (p, '\n') ?: s + slen; + return nbdkit_strndup_intern (p, n - p); + + case MISSING: + return ""; + + case ERROR: + return NULL; + + case RET_FALSE: + nbdkit_error ("%s: %s method returned unexpected code (3/false)", + script, method); + errno = EIO; + return NULL; + + default: abort (); + } +} + void * sh_open (int readonly) { diff --git a/plugins/sh/sh.c b/plugins/sh/sh.c index 374888a4..4fcc2a5a 100644 --- a/plugins/sh/sh.c +++ b/plugins/sh/sh.c @@ -301,6 +301,7 @@ static struct nbdkit_plugin plugin = { .preconnect = sh_preconnect, .list_exports = sh_list_exports, + .default_export = sh_default_export, .open = sh_open, .close = sh_close, diff --git a/plugins/sh/example.sh b/plugins/sh/example.sh index 4f547db0..e0e1b773 100755 --- a/plugins/sh/example.sh +++ b/plugins/sh/example.sh @@ -85,7 +85,7 @@ case "$1" in echo parallel ;; - list_exports) + list_exports | default_export) # The following lists the names of all files in the current # directory that do not contain whitespace, backslash, or single # quotes. No description accompanies the export names. diff --git a/tests/test-eval-exports.sh b/tests/test-eval-exports.sh index 7c946378..14b4c2ce 100755 --- a/tests/test-eval-exports.sh +++ b/tests/test-eval-exports.sh @@ -37,8 +37,8 @@ source ./functions.sh set -e set -x -# requires nbdinfo --version # nbdinfo 1.3.9 was broken, so check this instead: -requires nbdkit -U - memory 1 --run 'nbdinfo --size --json "$uri"' +requires nbdinfo --version +requires nbdsh -c 'print (h.set_full_info)' requires jq --version sock=$(mktemp -u) @@ -57,20 +57,19 @@ diff -u <(jq -c \ '[.exports[] | [."export-name", .description, ."export-size"]]' \ eval-exports.out) <(printf %s\\n '[["",null,0]]') -# Start a long-running server with .list_exports set to varying contents +# Start a long-running server with .list_exports and .default_export +# set to varying contents start_nbdkit -P eval-exports.pid -U $sock eval get_size='echo "$2"|wc -c' \ - open='echo "$3"' list_exports="cat '$PWD/eval-exports.list'" + open='echo "$3"' list_exports="cat '$PWD/eval-exports.list'" \ + default_export="cat '$PWD/eval-exports.list'" # do_nbdkit EXPNAME EXPOUT do_nbdkit () { # Check how the default export name is handled - # nbdinfo currently makes multiple connections, so we can't use the - # long-running server for validating default export name. - # XXX FIXME: requires .default_export in eval - : || nbdkit -U - -v eval list_exports="cat '$PWD/eval-exports.list'" \ - open='[ "$3" = "'"$1"'" ] || { echo EINVAL wrong export >&2; exit 1; }' \ - get_size='echo 0' --run 'nbdsh -u "$uri" -c "exit()"' + nbdinfo --no-content nbd+unix://\?socket=$sock >eval-exports.out + diff -u <(sed -n 's/export="\(.*\)":/\1/p' eval-exports.out) \ + <(printf %s\\n "$1") # Check what exports are listed nbdinfo --list --json nbd+unix://\?socket=$sock >eval-exports.out cat eval-exports.out @@ -79,9 +78,21 @@ do_nbdkit () eval-exports.out) <(printf %s\\n "$2") } -# With no file, .list_exports fails, but connecting works +# With no file, .list_exports and .default_export both fail, preventing +# connection to the default export, but not other exports nbdinfo --list --json nbd+unix://\?socket=$sock && fail=1 -nbdsh -u nbd+unix://\?socket=$sock -c 'quit()' +nbdsh -u nbd+unix://\?socket=$sock -c 'quit()' && fail=1 +nbdsh -u nbd+unix:///name\?socket=$sock -c 'quit()' + +# Setting .default_export but not .list_exports advertises the canonical name +nbdkit -U - eval default_export='echo hello' get_size='echo 0' \ + --run 'nbdinfo --list "$uri"' >eval-exports.out +diff -u <(grep '^export=' eval-exports.out) <(echo 'export="hello":') + +# Failing .default_export without .list_exports results in an empty list +nbdkit -U - eval default_export='echo ENOENT >&2; exit 1' get_size='echo 0' \ + --run 'nbdinfo --list "$uri"' >eval-exports.out +diff -u <(grep '^export=' eval-exports.out) /dev/null # Various spellings of empty lists, producing 0 exports for fmt in '' 'NAMES\n' 'INTERLEAVED\n' 'NAMES+DESCRIPTIONS\n'; do diff --git a/tests/test-export-info.sh b/tests/test-export-info.sh index b0dd4ce8..984d86c8 100755 --- a/tests/test-export-info.sh +++ b/tests/test-export-info.sh @@ -43,7 +43,7 @@ rm -f $files cleanup_fn rm -f $files # Create an nbdkit sh plugin for checking NBD_INFO replies to NBD_OPT_GO. -# XXX Update when .default_export and .export_description are implemented in sh +# XXX Update when .export_description is implemented in sh start_nbdkit -P export-info.pid -U $sock \ sh - <<'EOF' case "$1" in @@ -102,11 +102,10 @@ assert h.get_canonical_export_name () == "a" h.set_export_name ("") h.opt_info () -# XXX Adjust once default export works -assert h.get_canonical_export_name () == "" +assert h.get_canonical_export_name () == "hello" h.opt_go () -assert h.get_canonical_export_name () == "" +assert h.get_canonical_export_name () == "hello" h.shutdown () ' diff --git a/tests/test-tls-fallback.sh b/tests/test-tls-fallback.sh index cf54a606..94449f31 100755 --- a/tests/test-tls-fallback.sh +++ b/tests/test-tls-fallback.sh @@ -60,12 +60,15 @@ cleanup_fn rm -f $files # Run dual-mode server start_nbdkit -P $pid -U $sock --tls=on --tls-psk=keys.psk \ --filter=tls-fallback sh - tlsreadme=$'dummy\n' <<\EOF +check () { + if test "$1" != true; then + echo 'EINVAL unexpected tls mode' 2>&1; exit 1 + fi +} case $1 in list_exports) echo NAMES; echo hello; echo world ;; - open) if test "$4" != true; then - echo 'EINVAL unexpected tls mode' 2>&1; exit 1 - fi - echo $3 ;; + default_export) check "$3"; echo hello ;; + open) check "$4"; echo $3 ;; get_size) echo "$2" | wc -c ;; pread) echo "$2" | dd skip=$4 count=$3 iflag=skip_bytes,count_bytes ;; can_write | can_trim) exit 0 ;; -- 2.28.0