From patchwork Sun Nov 27 01:56:03 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 9448627 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id DF0D960235 for ; Sun, 27 Nov 2016 01:57:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D4E7126220 for ; Sun, 27 Nov 2016 01:57:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C994F26785; Sun, 27 Nov 2016 01:57:41 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E5A0126220 for ; Sun, 27 Nov 2016 01:57:40 +0000 (UTC) Received: from localhost ([::1]:52378 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cAoip-00025i-U1 for patchwork-qemu-devel@patchwork.kernel.org; Sat, 26 Nov 2016 20:57:39 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42839) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cAohw-0001oX-5G for qemu-devel@nongnu.org; Sat, 26 Nov 2016 20:56:45 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cAohv-0006ng-5h for qemu-devel@nongnu.org; Sat, 26 Nov 2016 20:56:44 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54264) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cAohs-0006mW-6c; Sat, 26 Nov 2016 20:56:40 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 46CF08B11B; Sun, 27 Nov 2016 01:56:39 +0000 (UTC) Received: from localhost (ovpn-116-37.phx2.redhat.com [10.3.116.37]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id uAR1ub2U027519 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Sat, 26 Nov 2016 20:56:38 -0500 From: Max Reitz To: qemu-block@nongnu.org Date: Sun, 27 Nov 2016 02:56:03 +0100 Message-Id: <20161127015622.24105-6-mreitz@redhat.com> In-Reply-To: <20161127015622.24105-1-mreitz@redhat.com> References: <20161127015622.24105-1-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Sun, 27 Nov 2016 01:56:39 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 05/24] block: Make path_combine() return the path X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Alberto Garcia , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Besides being safe for arbitrary path lengths, after some follow-up patches all callers will want a freshly allocated buffer anyway. In the meantime, path_combine_deprecated() is added which has the same interface as path_combine() had before this patch. All callers to that function will be converted in follow-up patches. Signed-off-by: Max Reitz Reviewed-by: Alberto Garcia --- block.c | 81 +++++++++++++++++++++++++++++---------------------- block/vmdk.c | 3 +- include/block/block.h | 4 +-- 3 files changed, 48 insertions(+), 40 deletions(-) diff --git a/block.c b/block.c index 0b37c2e..70076f4 100644 --- a/block.c +++ b/block.c @@ -148,48 +148,59 @@ int path_is_absolute(const char *path) #endif } -/* if filename is absolute, just copy it to dest. Otherwise, build a +/* if filename is absolute, just return its duplicate. Otherwise, build a path to it by considering it is relative to base_path. URL are supported. */ -void path_combine(char *dest, int dest_size, - const char *base_path, - const char *filename) +char *path_combine(const char *base_path, const char *filename) { const char *p, *p1; + char *result; int len; - if (dest_size <= 0) - return; if (path_is_absolute(filename)) { - pstrcpy(dest, dest_size, filename); + return g_strdup(filename); + } + + p = strchr(base_path, ':'); + if (p) { + p++; } else { - p = strchr(base_path, ':'); - if (p) - p++; - else - p = base_path; - p1 = strrchr(base_path, '/'); + p = base_path; + } + p1 = strrchr(base_path, '/'); #ifdef _WIN32 - { - const char *p2; - p2 = strrchr(base_path, '\\'); - if (!p1 || p2 > p1) - p1 = p2; + { + const char *p2; + p2 = strrchr(base_path, '\\'); + if (!p1 || p2 > p1) { + p1 = p2; } + } #endif - if (p1) - p1++; - else - p1 = base_path; - if (p1 > p) - p = p1; - len = p - base_path; - if (len > dest_size - 1) - len = dest_size - 1; - memcpy(dest, base_path, len); - dest[len] = '\0'; - pstrcat(dest, dest_size, filename); + if (p1) { + p1++; + } else { + p1 = base_path; + } + if (p1 > p) { + p = p1; } + len = p - base_path; + + result = g_malloc(len + strlen(filename) + 1); + memcpy(result, base_path, len); + strcpy(result + len, filename); + + return result; +} + +static void path_combine_deprecated(char *dest, int dest_size, + const char *base_path, + const char *filename) +{ + char *combined = path_combine(base_path, filename); + pstrcpy(dest, dest_size, combined); + g_free(combined); } void bdrv_get_full_backing_filename_from_filename(const char *backed, @@ -205,7 +216,7 @@ void bdrv_get_full_backing_filename_from_filename(const char *backed, error_setg(errp, "Cannot use relative backing file names for '%s'", backed); } else { - path_combine(dest, sz, backed, backing); + path_combine_deprecated(dest, sz, backed, backing); } } @@ -3178,8 +3189,8 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, } else { /* If not an absolute filename path, make it relative to the current * image's filename path */ - path_combine(filename_tmp, PATH_MAX, curr_bs->filename, - backing_file); + path_combine_deprecated(filename_tmp, PATH_MAX, curr_bs->filename, + backing_file); /* We are going to compare absolute pathnames */ if (!realpath(filename_tmp, filename_full)) { @@ -3188,8 +3199,8 @@ BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, /* We need to make sure the backing filename we are comparing against * is relative to the current image filename (or absolute) */ - path_combine(filename_tmp, PATH_MAX, curr_bs->filename, - curr_bs->backing_file); + path_combine_deprecated(filename_tmp, PATH_MAX, curr_bs->filename, + curr_bs->backing_file); if (!realpath(filename_tmp, backing_file_full)) { continue; diff --git a/block/vmdk.c b/block/vmdk.c index a11c27a..aad2d7d 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -846,8 +846,7 @@ static int vmdk_parse_extents(const char *desc, BlockDriverState *bs, return -EINVAL; } - extent_path = g_malloc0(PATH_MAX); - path_combine(extent_path, PATH_MAX, desc_file_path, fname); + extent_path = path_combine(desc_file_path, fname); ret = snprintf(extent_opt_prefix, 32, "extents.%d", s->num_extents); assert(ret < 32); diff --git a/include/block/block.h b/include/block/block.h index 49bb0b2..6e5d4b2 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -444,9 +444,7 @@ void bdrv_get_full_backing_filename_from_filename(const char *backed, int path_has_protocol(const char *path); int path_is_absolute(const char *path); -void path_combine(char *dest, int dest_size, - const char *base_path, - const char *filename); +char *path_combine(const char *base_path, const char *filename); int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos); int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos);