From patchwork Thu Dec 12 16:38:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 1208662 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="TJG78EEV"; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 47YgMQ2gx6z9sNH for ; Fri, 13 Dec 2019 04:12:02 +1100 (AEDT) Received: from localhost ([::1]:34478 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ifS0N-0006tO-Tu for incoming@patchwork.ozlabs.org; Thu, 12 Dec 2019 12:11:59 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:50548) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ifRVi-0005t2-Lq for qemu-devel@nongnu.org; Thu, 12 Dec 2019 11:40:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ifRVh-0002Hp-HT for qemu-devel@nongnu.org; Thu, 12 Dec 2019 11:40:18 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:39113 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ifRVh-0002H4-CS for qemu-devel@nongnu.org; Thu, 12 Dec 2019 11:40:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1576168816; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=WG+Al5te8uqZSlxkLLc9k3C99FeovJnhxsjdX0wcZlg=; b=TJG78EEVU4t1mNHKKv49P0SdL9SVddqXbrFhCaM25HcD+8cEUW4wqGpQS+aQvjnPW93yfy SglUtPt33Sxb78V0IIJuJt3I5WIB/08d7w/qd1toMBkxUH+W0BsO5GCiptziYR7LVN1pnE EVNqU5uvgoqq/C42P6aS5vrOAo4pBg0= 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-99-nd6nUNfSNjuPXYOw0flkMQ-1; Thu, 12 Dec 2019 11:40:15 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7B6BD8017DF for ; Thu, 12 Dec 2019 16:40:14 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-116-226.ams2.redhat.com [10.36.116.226]) by smtp.corp.redhat.com (Postfix) with ESMTP id 99A0C60BE1; Thu, 12 Dec 2019 16:40:13 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com, vgoyal@redhat.com Subject: [PATCH 041/104] virtiofsd: add fuse_mbuf_iter API Date: Thu, 12 Dec 2019 16:38:01 +0000 Message-Id: <20191212163904.159893-42-dgilbert@redhat.com> In-Reply-To: <20191212163904.159893-1-dgilbert@redhat.com> References: <20191212163904.159893-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: nd6nUNfSNjuPXYOw0flkMQ-1 X-Mimecast-Spam-Score: 0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 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: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Stefan Hajnoczi Introduce an API for consuming bytes from a buffer with size checks. All FUSE operations will be converted to use this safe API instead of void *inarg. Signed-off-by: Stefan Hajnoczi Reviewed-by: Sergio Lopez --- tools/virtiofsd/buffer.c | 28 ++++++++++++++++++++ tools/virtiofsd/fuse_common.h | 49 ++++++++++++++++++++++++++++++++++- 2 files changed, 76 insertions(+), 1 deletion(-) diff --git a/tools/virtiofsd/buffer.c b/tools/virtiofsd/buffer.c index 1d7e6d2439..f59d8d72eb 100644 --- a/tools/virtiofsd/buffer.c +++ b/tools/virtiofsd/buffer.c @@ -338,3 +338,31 @@ ssize_t fuse_buf_copy(struct fuse_bufvec *dstv, struct fuse_bufvec *srcv, return copied; } + +void *fuse_mbuf_iter_advance(struct fuse_mbuf_iter *iter, size_t len) +{ + void *ptr; + + if (len > iter->size - iter->pos) { + return NULL; + } + + ptr = iter->mem + iter->pos; + iter->pos += len; + return ptr; +} + +const char *fuse_mbuf_iter_advance_str(struct fuse_mbuf_iter *iter) +{ + const char *str = iter->mem + iter->pos; + size_t remaining = iter->size - iter->pos; + size_t i; + + for (i = 0; i < remaining; i++) { + if (str[i] == '\0') { + iter->pos += i + 1; + return str; + } + } + return NULL; +} diff --git a/tools/virtiofsd/fuse_common.h b/tools/virtiofsd/fuse_common.h index 7bed38b436..147c043bd9 100644 --- a/tools/virtiofsd/fuse_common.h +++ b/tools/virtiofsd/fuse_common.h @@ -771,10 +771,57 @@ size_t fuse_buf_size(const struct fuse_bufvec *bufv); ssize_t fuse_buf_copy(struct fuse_bufvec *dst, struct fuse_bufvec *src, enum fuse_buf_copy_flags flags); +/** + * Memory buffer iterator + * + */ +struct fuse_mbuf_iter { + /** + * Data pointer + */ + void *mem; + + /** + * Total length, in bytes + */ + size_t size; + + /** + * Offset from start of buffer + */ + size_t pos; +}; + +/* Initialize memory buffer iterator from a fuse_buf */ +#define FUSE_MBUF_ITER_INIT(fbuf) \ + ((struct fuse_mbuf_iter){ \ + .mem = fbuf->mem, \ + .size = fbuf->size, \ + .pos = 0, \ + }) + +/** + * Consume bytes from a memory buffer iterator + * + * @param iter memory buffer iterator + * @param len number of bytes to consume + * @return pointer to start of consumed bytes or + * NULL if advancing beyond end of buffer + */ +void *fuse_mbuf_iter_advance(struct fuse_mbuf_iter *iter, size_t len); + +/** + * Consume a NUL-terminated string from a memory buffer iterator + * + * @param iter memory buffer iterator + * @return pointer to the string or + * NULL if advancing beyond end of buffer or there is no NUL-terminator + */ +const char *fuse_mbuf_iter_advance_str(struct fuse_mbuf_iter *iter); + /* * Signal handling */ - /** * Exit session on HUP, TERM and INT signals and ignore PIPE signal *