Re: [Libguestfs] [libnbd PATCH 2/2] tests: Test server response to oversize requests

Improve some existing tests to cover client safety valves for oversize requests, and add a new test that tests libnbd behavior on server errors to the same sort of requests. The new test requires a parallel patch posted to nbdkit to teach 'nbdkit eval' how to forcefully disconnect the server on particarly oversize write requests, emulating

qemu-nbd behavior. --- tests/Makefile.am | 15 +++- tests/errors-client-oversize.c | 18 +++- tests/errors-server-oversize.c | 151 ++++++++++++++++++++++++++++++++ tests/errors-server-unaligned.c | 2 + .gitignore | 1 + 5 files changed, 185 insertions(+), 2 deletions(-) create mode 100644 tests/errors-server-oversize.c diff --git a/tests/Makefile.am b/tests/Makefile.am index 70083e5c..0b9c454e 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -177,6 +177,7 @@ check_PROGRAMS += \ errors-multiple-disconnects \ errors-server-invalid-offset \ errors-client-oversize \ + errors-server-oversize \ errors-client-unadvertised-cmd \ errors-server-unadvertised-cmd \ errors-client-unaligned \ @@ -247,6 +248,7 @@ TESTS += \ errors-multiple-disconnects \ errors-server-invalid-offset \ errors-client-oversize \ + errors-server-oversize \ errors-client-unadvertised-cmd \ errors-server-unadvertised-cmd \ errors-client-unaligned \ @@ -343,9 +345,20 @@ errors_multiple_disconnects_LDADD = $(top_builddir)/lib/libnbd.la errors_server_invalid_offset_SOURCES = errors-server-invalid-offset.c errors_server_invalid_offset_LDADD = $(top_builddir)/lib/libnbd.la -errors_client_oversize_SOURCES = errors-client-oversize.c +errors_client_oversize_SOURCES = \ + errors-client-oversize.c \ + requires.c \ + requires.h \ + $(NULL) errors_client_oversize_LDADD = $(top_builddir)/lib/libnbd.la +errors_server_oversize_SOURCES = \ + errors-server-oversize.c \ + requires.c \ + requires.h \ + $(NULL) +errors_server_oversize_LDADD = $(top_builddir)/lib/libnbd.la + errors_client_unadvertised_cmd_SOURCES = errors-client-unadvertised-cmd.c \ requires.c requires.h errors_client_unadvertised_cmd_LDADD = $(top_builddir)/lib/libnbd.la diff --git a/tests/errors-client-oversize.c b/tests/errors-client-oversize.c index 7e5b5421..739b41e9 100644 --- a/tests/errors-client-oversize.c +++ b/tests/errors-client-oversize.c @@ -30,6 +30,7 @@ #include <sys/stat.h> #include <libnbd.h> +#include "requires.h" #define MAXSIZE 68157440 /* 65M, oversize on purpose */ @@ -62,10 +63,15 @@ main (int argc, char *argv[]) { struct nbd_handle *nbd; const char *cmd[] = { - "nbdkit", "-s", "-v", "--exit-with-parent", "memory", "68157440", NULL, + "nbdkit", "-s", "-v", "--exit-with-parent", + "memory", "68157440", + "--filter=blocksize-policy", "blocksize-maximum=32M", + "blocksize-error-policy=error", + NULL }; progname = argv[0]; + requires ("nbdkit --version --filter=blocksize-policy null"); nbd = nbd_create (); if (nbd == NULL) { @@ -87,6 +93,7 @@ main (int argc, char *argv[]) exit (EXIT_FAILURE); } check (ERANGE, "nbd_pread: "); + if (nbd_aio_pwrite (nbd, buf, MAXSIZE, 0, NBD_NULL_COMPLETION, 0) != -1) { fprintf (stderr, "%s: test failed: " @@ -96,6 +103,15 @@ main (int argc, char *argv[]) } check (ERANGE, "nbd_aio_pwrite: "); + if (nbd_aio_pwrite (nbd, buf, 33*1024*1024, 0, + NBD_NULL_COMPLETION, 0) != -1) { + fprintf (stderr, "%s: test failed: " + "nbd_aio_pwrite did not fail with oversize request\n", + argv[0]); + exit (EXIT_FAILURE); + } + check (ERANGE, "nbd_aio_pwrite: "); + nbd_close (nbd); exit (EXIT_SUCCESS); } diff --git a/tests/errors-server-oversize.c b/tests/errors-server-oversize.c new file mode 100644 index 00000000..e55aafc3 --- /dev/null +++ b/tests/errors-server-oversize.c @@ -0,0 +1,151 @@ +/* NBD client library in userspace + * Copyright (C) 2013-2022 Red Hat Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/* Deliberately provoke some errors and check the error messages from + * nbd_get_error etc look reasonable. + */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <unistd.h> +#include <inttypes.h> +#include <sys/stat.h> + +#include <libnbd.h> +#include "requires.h" + +#define MAXSIZE 68157440 /* 65M, oversize on purpose */ + +static char *progname; +static char buf[MAXSIZE]; + +static void +check (int experr, const char *prefix) +{ + const char *msg = nbd_get_error (); + int errnum = nbd_get_errno (); + + fprintf (stderr, "error: \"%s\"\n", msg); + fprintf (stderr, "errno: %d (%s)\n", errnum, strerror (errnum)); + if (strncmp (msg, prefix, strlen (prefix)) != 0) { + fprintf (stderr, "%s: test failed: missing context prefix: %s\n", + progname, msg); + exit (EXIT_FAILURE); + } + if (errnum != experr) { + fprintf (stderr, "%s: test failed: " + "expected errno = %d (%s), but got %d\n", + progname, experr, strerror (experr), errnum); + exit (EXIT_FAILURE); + } +} + +static void +check_server_fail (struct nbd_handle *h, int64_t cookie, + const char *cmd, int experr) +{ + int r; + + if (cookie == -1) { + fprintf (stderr, "%s: test failed: %s not sent to server\n", + progname, cmd); + exit (EXIT_FAILURE); + } + + while ((r = nbd_aio_command_completed (h, cookie)) == 0) { + if (nbd_poll (h, -1) == -1) { + fprintf (stderr, "%s: test failed: poll failed while awaiting %s: %s\n", + progname, cmd, nbd_get_error ()); + exit (EXIT_FAILURE); + } + } + + if (r != -1) { + fprintf (stderr, "%s: test failed: %s did not fail at server\n", + progname, cmd); + exit (EXIT_FAILURE); + } + check (experr, "nbd_aio_command_completed: "); +} + +int +main (int argc, char *argv[]) +{ + struct nbd_handle *nbd; + const char *cmd[] = { + "nbdkit", "-s", "-v", "--exit-with-parent", "eval", + "get_size= echo 68157440", + "block_size= echo 1 512 16M", + "pread= echo EIO >&2; exit 1", + "pwrite= if test $3 -gt $((32*1024*1024)); then\n" + " exit 6\n" /* Hard disconnect */ + " elif test $3 -gt $((16*1024*1024)); then\n" + " echo EOVERFLOW >&2; exit 1\n" + " fi\n" + " cat >/dev/null", + NULL, + }; + uint32_t strict; + + progname = argv[0]; + requires ("nbdkit --dump-plugin eval | grep ^max_known_status="); + + nbd = nbd_create (); + if (nbd == NULL) { + fprintf (stderr, "%s\n", nbd_get_error ()); + exit (EXIT_FAILURE); + } + + /* Connect to the server. */ + if (nbd_connect_command (nbd, (char **) cmd) == -1) { + fprintf (stderr, "%s: %s\n", argv[0], nbd_get_error ()); + exit (EXIT_FAILURE); + } + + /* Check the advertised max sizes. */ + printf ("server block size maximum: %" PRIi64 "\n", + nbd_get_block_size (nbd, LIBNBD_SIZE_MAXIMUM)); + printf ("libnbd payload size maximum: %" PRIi64 "\n", + nbd_get_block_size (nbd, LIBNBD_SIZE_PAYLOAD)); + + /* Disable client-side safety check */ + strict = nbd_get_strict_mode (nbd) & ~LIBNBD_STRICT_PAYLOAD;

+ if (nbd_set_strict_mode (nbd, strict) == -1) { + fprintf (stderr, "%s\n", nbd_get_error ()); + exit (EXIT_FAILURE); + } + + /* Handle graceful server rejection of oversize request */ + check_server_fail (nbd, + nbd_aio_pwrite (nbd, buf, 17*1024*1024, 0, + NBD_NULL_COMPLETION, 0), + "17M nbd_aio_pwrite", EINVAL); + + /* Handle abrupt server rejection of oversize request */ + check_server_fail (nbd, + nbd_aio_pwrite (nbd, buf, 33*1024*1024, 0, + NBD_NULL_COMPLETION, 0), + "33M nbd_aio_pwrite", ENOTCONN); + + nbd_close (nbd); + exit (EXIT_SUCCESS); +} diff --git a/tests/errors-server-unaligned.c b/tests/errors-server-unaligned.c index ac374976..6dbd6e29 100644 --- a/tests/errors-server-unaligned.c +++ b/tests/errors-server-unaligned.c @@ -123,6 +123,8 @@ main (int argc, char *argv[]) nbd_get_block_size (nbd, LIBNBD_SIZE_PREFERRED)); printf ("server block size maximum: %" PRIi64 "\n", nbd_get_block_size (nbd, LIBNBD_SIZE_MAXIMUM)); + printf ("libnbd payload size maximum: %" PRIi64 "\n", + nbd_get_block_size (nbd, LIBNBD_SIZE_PAYLOAD)); fflush (stdout); /* Send an unaligned read, server-side */ diff --git a/.gitignore b/.gitignore index fe929d6d..f4273713 100644 --- a/.gitignore +++ b/.gitignore @@ -215,6 +215,7 @@ Makefile.in /tests/errors-poll-no-fd /tests/errors-pread-structured /tests/errors-server-invalid-offset +/tests/errors-server-oversize /tests/errors-server-unadvertised-cmd /tests/errors-server-unaligned /tests/errors-server-unknown-flags