From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57710) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fYKTt-0004cA-11 for qemu-devel@nongnu.org; Wed, 27 Jun 2018 20:08:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fYKTp-0003za-Af for qemu-devel@nongnu.org; Wed, 27 Jun 2018 20:08:12 -0400 From: Max Reitz Date: Thu, 28 Jun 2018 02:07:23 +0200 Message-Id: <20180628000745.4477-10-mreitz@redhat.com> In-Reply-To: <20180628000745.4477-1-mreitz@redhat.com> References: <20180628000745.4477-1-mreitz@redhat.com> Subject: [Qemu-devel] [PATCH v9 09/31] block: Make path_combine() return the path List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, Max Reitz , Kevin Wolf 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 Reviewed-by: Kevin Wolf --- include/block/block.h | 4 +- block.c | 85 ++++++++++++++++++++++++------------------- block/vmdk.c | 3 +- 3 files changed, 49 insertions(+), 43 deletions(-) diff --git a/include/block/block.h b/include/block/block.h index d0a840d7a6..f72ab30408 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -466,9 +466,7 @@ 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); diff --git a/block.c b/block.c index 262b66b00f..be0a8475aa 100644 --- a/block.c +++ b/block.c @@ -152,53 +152,62 @@ 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 *protocol_stripped = NULL; const char *p, *p1; + char *result; int len; - if (dest_size <= 0) - return; if (path_is_absolute(filename)) { - pstrcpy(dest, dest_size, filename); - } else { - const char *protocol_stripped = NULL; + return g_strdup(filename); + } - if (path_has_protocol(base_path)) { - protocol_stripped = strchr(base_path, ':'); - if (protocol_stripped) { - protocol_stripped++; - } + if (path_has_protocol(base_path)) { + protocol_stripped = strchr(base_path, ':'); + if (protocol_stripped) { + protocol_stripped++; } - p = protocol_stripped ?: base_path; + } + p = protocol_stripped ?: base_path; - p1 = strrchr(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); } /* @@ -297,7 +306,7 @@ 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); } } @@ -4304,8 +4313,8 @@ 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)) { @@ -4314,8 +4323,8 @@ 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 228999eeba..bec4a222e3 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -867,8 +867,7 @@ 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); -- 2.17.1