From patchwork Wed Dec 2 09:02:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 11945523 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87013C64E7C for ; Wed, 2 Dec 2020 09:56:52 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DEA9A206C0 for ; Wed, 2 Dec 2020 09:56:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DEA9A206C0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:58288 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kkOsT-0006XX-SX for qemu-devel@archiver.kernel.org; Wed, 02 Dec 2020 04:56:49 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:53514) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kkO3g-0003a1-GJ for qemu-devel@nongnu.org; Wed, 02 Dec 2020 04:04:20 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:43805) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kkO3d-0004dn-Ks for qemu-devel@nongnu.org; Wed, 02 Dec 2020 04:04:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606899857; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UnDHar2bdds6odKKiAb3/vfn+NJPp4kuSa2PND4522U=; b=Wo4K2BaE9KRfHsGHhH531mpiehRDQUYV2Uc0Y/tYnVrYy/jkb1lvBNx0QIyL+0jO+CC9MJ tW4iuDGzdBn+6U1KG1P8vD4IlnGSyTLl6etlkw9D8TKaSgRYOqsAn1IogeS2EvjhVgT0V+ tv6jsMFxAZv9GrMttzhkWbNepHrFS8o= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-445-L6I_DyZhO6m6d0dgoIWCuw-1; Wed, 02 Dec 2020 04:04:15 -0500 X-MC-Unique: L6I_DyZhO6m6d0dgoIWCuw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 01B7A102CB74; Wed, 2 Dec 2020 09:03:41 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id 51EF161F20; Wed, 2 Dec 2020 09:03:40 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PATCH 06/28] keyval: accept escaped commas in implied option Date: Wed, 2 Dec 2020 04:02:43 -0500 Message-Id: <20201202090305.4129317-7-pbonzini@redhat.com> In-Reply-To: <20201202090305.4129317-1-pbonzini@redhat.com> References: <20201202090305.4129317-1-pbonzini@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pbonzini@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -35 X-Spam_score: -3.6 X-Spam_bar: --- X-Spam_report: (-3.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.497, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, imammedo@redhat.com, armbru@redhat.com, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This is used with the weirdly-named device "SUNFD,fdtwo": $ qemu-system-sparc -device SUNW,,fdtwo,help SUNW,fdtwo options: drive= - Node name or ID of a block device to use as a backend fallback= - FDC drive type, 144/288/120/none/auto (default: "144") ... Therefore, accepting it is a preparatory step towards keyval-ifying -device and the device_add monitor command. In general, however, this unexpected wart of the keyval syntax leads to suboptimal errors compared to QemuOpts: $ ./qemu-system-x86_64 -object foo,,bar,id=obj qemu-system-x86_64: -object foo,,bar,id=obj: invalid object type: foo,bar $ storage-daemon/qemu-storage-daemon --object foo,,bar,id=obj qemu-storage-daemon: Invalid parameter '' To implement this, the flow of the parser is changed to first unescape everything up to the next comma or equal sign. This is done in a new function keyval_fetch_string for both the key and value part. Keys therefore are now parsed in unescaped form, but this makes no difference in practice because a comma is an invalid character for a QAPI name. Thus keys with a comma in them are rejected anyway, as demonstrated by the new testcase. As a side effect of the new code, parse errors are slightly improved as well: "Invalid parameter ''" becomes "Expected parameter before '='" when keyval is fed a string starting with an equal sign. The slightly baroque interface of keyval_fetch_string lets me keep the key parsing loop mostly untouched. It is simplified in the next patch, however. Signed-off-by: Paolo Bonzini --- include/qemu/help_option.h | 11 --- tests/test-keyval.c | 21 +++--- util/keyval.c | 142 ++++++++++++++++++++----------------- 3 files changed, 91 insertions(+), 83 deletions(-) diff --git a/include/qemu/help_option.h b/include/qemu/help_option.h index ca6389a154..328d2a89fd 100644 --- a/include/qemu/help_option.h +++ b/include/qemu/help_option.h @@ -19,15 +19,4 @@ static inline bool is_help_option(const char *s) return !strcmp(s, "?") || !strcmp(s, "help"); } -static inline int starts_with_help_option(const char *s) -{ - if (*s == '?') { - return 1; - } - if (g_str_has_prefix(s, "help")) { - return 4; - } - return 0; -} - #endif diff --git a/tests/test-keyval.c b/tests/test-keyval.c index ee927fe4e4..19f664f535 100644 --- a/tests/test-keyval.c +++ b/tests/test-keyval.c @@ -89,6 +89,11 @@ static void test_keyval_parse(void) error_free_or_abort(&err); g_assert(!qdict); + /* Keys must be QAPI identifiers */ + qdict = keyval_parse("weird,,=key", NULL, NULL, &err); + error_free_or_abort(&err); + g_assert(!qdict); + /* Multiple keys, last one wins */ qdict = keyval_parse("a=1,b=2,,x,a=3", NULL, NULL, &error_abort); g_assert_cmpuint(qdict_size(qdict), ==, 2); @@ -178,15 +183,15 @@ static void test_keyval_parse(void) error_free_or_abort(&err); g_assert(!qdict); - /* Likewise (qemu_opts_parse(): implied key with comma value) */ - qdict = keyval_parse(",,,a=1", "implied", NULL, &err); - error_free_or_abort(&err); - g_assert(!qdict); + /* Implied key's value can have a comma */ + qdict = keyval_parse(",,,a=1", "implied", NULL, &error_abort); + g_assert_cmpstr(qdict_get_try_str(qdict, "implied"), ==, ","); + g_assert_cmpstr(qdict_get_try_str(qdict, "a"), ==, "1"); + qobject_unref(qdict); - /* Implied key's value can't have comma (qemu_opts_parse(): it can) */ - qdict = keyval_parse("val,,ue", "implied", NULL, &err); - error_free_or_abort(&err); - g_assert(!qdict); + qdict = keyval_parse("val,,ue", "implied", NULL, &error_abort); + g_assert_cmpstr(qdict_get_try_str(qdict, "implied"), ==, "val,ue"); + qobject_unref(qdict); /* Empty key is not an implied key */ qdict = keyval_parse("=val", "implied", NULL, &err); diff --git a/util/keyval.c b/util/keyval.c index 7f625ad33c..eb9b9c55ec 100644 --- a/util/keyval.c +++ b/util/keyval.c @@ -16,8 +16,8 @@ * key-vals = [ key-val { ',' key-val } [ ',' ] ] * key-val = key '=' val | help * key = key-fragment { '.' key-fragment } - * key-fragment = / [^=,.]+ / - * val = { / [^,]+ / | ',,' } + * key-fragment = { / [^=,.] / | ',,' } + * val = { / [^,] / | ',,' } * help = 'help' | '?' * * Semantics defined by reduction to JSON: @@ -78,13 +78,13 @@ * Alternative syntax for use with an implied key: * * key-vals = [ key-val-1st { ',' key-val } [ ',' ] ] - * key-val-1st = val-no-key | key-val - * val-no-key = / [^=,]+ / - help + * key-val-1st = (val-no-key - help) | key-val + * val-no-key = { / [^=,] / | ',,' } * * where val-no-key is syntactic sugar for implied-key=val-no-key. * - * Note that you can't use the sugared form when the value contains - * '=' or ','. + * Note that you can't use the sugared form when the value is empty + * or contains '='. */ #include "qemu/osdep.h" @@ -141,7 +141,7 @@ static int key_to_index(const char *key, const char **end) * On failure, store an error through @errp and return NULL. */ static QObject *keyval_parse_put(QDict *cur, - const char *key_in_cur, QString *value, + const char *key_in_cur, const char *value, const char *key, const char *key_cursor, Error **errp) { @@ -152,20 +152,56 @@ static QObject *keyval_parse_put(QDict *cur, if (qobject_type(old) != (value ? QTYPE_QSTRING : QTYPE_QDICT)) { error_setg(errp, "Parameters '%.*s.*' used inconsistently", (int)(key_cursor - key), key); - qobject_unref(value); return NULL; } if (!value) { return old; /* already QDict, do nothing */ } - new = QOBJECT(value); /* replacement */ - } else { - new = value ? QOBJECT(value) : QOBJECT(qdict_new()); } + new = value ? QOBJECT(qstring_from_str(value)) : QOBJECT(qdict_new()); qdict_put_obj(cur, key_in_cur, new); return new; } +/* + * Parse and unescape the string (key or value) pointed to by @start, + * stopping at a single comma or if @key is true an equal sign. + * The string is unescaped and NUL-terminated in place. + * + * On return: + * - either NUL or the separator (comma or equal sign) is returned. + * - the length of the string is stored in @len. + * - @start is advanced to either the NUL or the first character past the + * separator. + */ +static char keyval_fetch_string(char **start, size_t *len, bool key) +{ + char sep; + char *p, *unescaped; + p = unescaped = *start; + for (;;) { + sep = *p; + if (!sep) { + break; + } + if (key && sep == '=') { + ++p; + break; + } + if (sep == ',') { + if (*++p != ',') { + break; + } + } + *unescaped++ = *p++; + } + + *unescaped = 0; + *len = unescaped - *start; + *start = p; + return sep; +} + /* * Parse one parameter from @params. * @@ -179,35 +215,42 @@ static QObject *keyval_parse_put(QDict *cur, * On success, return a pointer to the next parameter, or else to '\0'. * On failure, return NULL. */ -static const char *keyval_parse_one(QDict *qdict, const char *params, - const char *implied_key, bool *help, - Error **errp) +static char *keyval_parse_one(QDict *qdict, char *params, + const char *implied_key, bool *help, + Error **errp) { - const char *key, *key_end, *val_end, *s, *end; + const char *key, *key_end, *s, *end; + const char *val = NULL; + char sep; size_t len; char key_in_cur[128]; QDict *cur; int ret; QObject *next; - QString *val; key = params; - val_end = NULL; - len = strcspn(params, "=,"); - if (len && key[len] != '=') { - if (starts_with_help_option(key) == len) { + sep = keyval_fetch_string(¶ms, &len, true); + if (!len) { + if (sep) { + error_setg(errp, "Expected parameter before '%c%s'", sep, params); + } else { + error_setg(errp, "Expected parameter at end of string"); + } + return NULL; + } + if (sep != '=') { + if (is_help_option(key)) { *help = true; - s = key + len; - if (*s == ',') { - s++; - } - return s; + return params; } if (implied_key) { /* Desugar implied key */ + val = key; key = implied_key; - val_end = params + len; len = strlen(implied_key); + } else { + error_setg(errp, "No implicit parameter name for value '%s'", key); + return NULL; } } key_end = key + len; @@ -218,7 +261,7 @@ static const char *keyval_parse_one(QDict *qdict, const char *params, */ cur = qdict; s = key; - for (;;) { + do { /* Want a key index (unless it's first) or a QAPI name */ if (s != key && key_to_index(s, &end) >= 0) { len = end - s; @@ -254,46 +297,16 @@ static const char *keyval_parse_one(QDict *qdict, const char *params, memcpy(key_in_cur, s, len); key_in_cur[len] = 0; s += len; + } while (*s++ == '.'); - if (*s != '.') { - break; - } - s++; - } - - if (key == implied_key) { - assert(!*s); - val = qstring_from_substr(params, 0, val_end - params); - s = val_end; - if (*s == ',') { - s++; - } - } else { - if (*s != '=') { - error_setg(errp, "Expected '=' after parameter '%.*s'", - (int)(s - key), key); - return NULL; - } - s++; - - val = qstring_new(); - for (;;) { - if (!*s) { - break; - } else if (*s == ',') { - s++; - if (*s != ',') { - break; - } - } - qstring_append_chr(val, *s++); - } + if (key != implied_key) { + val = params; + keyval_fetch_string(¶ms, &len, false); } - if (!keyval_parse_put(cur, key_in_cur, val, key, key_end, errp)) { return NULL; } - return s; + return params; } static char *reassemble_key(GSList *key) @@ -438,10 +451,11 @@ QDict *keyval_parse(const char *params, const char *implied_key, { QDict *qdict = qdict_new(); QObject *listified; - const char *s; + g_autofree char *dup; + char *s; bool help = false; - s = params; + s = dup = g_strdup(params); while (*s) { s = keyval_parse_one(qdict, s, implied_key, &help, errp); if (!s) {