From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by passt.top (Postfix) with ESMTP id 1D6485A027A for ; Sat, 17 Feb 2024 16:07:30 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1708182448; 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=PhhR2OwiFHAWT+XpCjFaPuHYZ6SIVlJttjDFlUKzHPs=; b=FAllwzOgyC2UFtFSYddZs7m6z5XGZR9MHedyFWRLlkdBopjq3v5VBY5ZvWwasLZelC2I+Z MEg72457mb/RB91AZUxoLKiBL7GZDXaBoHsxvEYvHLEOFgBmG2KvyL1uuagqzgFr26+18p nC8p8pIoYdNUVGzQdbySdfXWC89kL48= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-260-Ec3IXRZnMdWzWnSKbkYtzQ-1; Sat, 17 Feb 2024 10:07:27 -0500 X-MC-Unique: Ec3IXRZnMdWzWnSKbkYtzQ-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CE83429AC006 for ; Sat, 17 Feb 2024 15:07:26 +0000 (UTC) Received: from virtlab218.virt.lab.eng.bos.redhat.com (virtlab218.virt.lab.eng.bos.redhat.com [10.19.152.190]) by smtp.corp.redhat.com (Postfix) with ESMTP id B2642492BE3; Sat, 17 Feb 2024 15:07:26 +0000 (UTC) From: Laurent Vivier To: passt-dev@passt.top Subject: [PATCH v3 1/9] iov: add some functions to manage iovec Date: Sat, 17 Feb 2024 16:07:17 +0100 Message-ID: <20240217150725.661467-2-lvivier@redhat.com> In-Reply-To: <20240217150725.661467-1-lvivier@redhat.com> References: <20240217150725.661467-1-lvivier@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII"; x-default=true Message-ID-Hash: 4NRENKFSWSBLDUQEHAZKYKHN6I2TRV4K X-Message-ID-Hash: 4NRENKFSWSBLDUQEHAZKYKHN6I2TRV4K X-MailFrom: lvivier@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: Laurent Vivier X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Introduce functions to copy to/from a buffer from/to an iovec array, to compute data length in in bytes of an iovec and to copy memory from an iovec to another. iov_from_buf(), iov_to_buf(), iov_size(), iov_copy(). Signed-off-by: Laurent Vivier --- Notes: v3: - update copyright statement (but keep it as proposed by Stefano) - open code of iov_fill_from_buf()/iov_fill_to_buf() into iov_frombuf()/iov_to_buf() - coding style cleanup - use size_t for the length of the vectors v2: - reorder added files in alphanetical order in Makefile - update comments, cosmetic cleanup - rename iov_from_buf_full/iov_to_buf_full to iov_fill_from_buf/iov_fill_to_buf - split loops that manage offset and bytes copy. - move iov_from_buf()/iov_to_buf() to iov.c Makefile | 8 +-- iov.c | 171 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ iov.h | 29 ++++++++++ 3 files changed, 204 insertions(+), 4 deletions(-) create mode 100644 iov.c create mode 100644 iov.h diff --git a/Makefile b/Makefile index af4fa87e7e13..156398b3844e 100644 --- a/Makefile +++ b/Makefile @@ -45,16 +45,16 @@ FLAGS += -DVERSION=\"$(VERSION)\" FLAGS += -DDUAL_STACK_SOCKETS=$(DUAL_STACK_SOCKETS) PASST_SRCS = arch.c arp.c checksum.c conf.c dhcp.c dhcpv6.c flow.c icmp.c \ - igmp.c isolation.c lineread.c log.c mld.c ndp.c netlink.c packet.c \ - passt.c pasta.c pcap.c pif.c port_fwd.c tap.c tcp.c tcp_splice.c udp.c \ - util.c + igmp.c iov.c isolation.c lineread.c log.c mld.c ndp.c netlink.c \ + packet.c passt.c pasta.c pcap.c pif.c port_fwd.c tap.c tcp.c \ + tcp_splice.c udp.c util.c QRAP_SRCS = qrap.c SRCS = $(PASST_SRCS) $(QRAP_SRCS) MANPAGES = passt.1 pasta.1 qrap.1 PASST_HEADERS = arch.h arp.h checksum.h conf.h dhcp.h dhcpv6.h flow.h \ - flow_table.h icmp.h inany.h isolation.h lineread.h log.h ndp.h \ + flow_table.h icmp.h inany.h iov.h isolation.h lineread.h log.h ndp.h \ netlink.h packet.h passt.h pasta.h pcap.h pif.h port_fwd.h siphash.h \ tap.h tcp.h tcp_conn.h tcp_splice.h udp.h util.h HEADERS = $(PASST_HEADERS) seccomp.h diff --git a/iov.c b/iov.c new file mode 100644 index 000000000000..1135f87e2f45 --- /dev/null +++ b/iov.c @@ -0,0 +1,171 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * iov.h - helpers for using (partial) iovecs. + * + * Copyright Red Hat + * Author: Laurent Vivier + * + * This file also contains code originally from QEMU include/qemu/iov.h + * and licensed under the following terms: + * + * Copyright (C) 2010 Red Hat, Inc. + * + * Author(s): + * Amit Shah + * Michael Tokarev + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + * Contributions after 2012-01-13 are licensed under the terms of the + * GNU GPL, version 2 or (at your option) any later version. + */ +#include + +#include "util.h" +#include "iov.h" + +/** + * iov_from_buf - Copy data from a buffer to an I/O vector (struct iovec) + * efficiently. + * + * @iov: Pointer to the array of struct iovec describing the + * scatter/gather I/O vector. + * @iov_cnt: Number of elements in the iov array. + * @offset: Byte offset in the iov array where copying should start. + * @buf: Pointer to the source buffer containing the data to copy. + * @bytes: Total number of bytes to copy from buf to iov. + * + * Returns: The number of bytes successfully copied. + */ +size_t iov_from_buf(const struct iovec *iov, size_t iov_cnt, + size_t offset, const void *buf, size_t bytes) +{ + unsigned int i; + size_t copied; + + if (__builtin_constant_p(bytes) && iov_cnt && + offset <= iov[0].iov_len && bytes <= iov[0].iov_len - offset) { + memcpy((char *)iov[0].iov_base + offset, buf, bytes); + return bytes; + } + + /* skipping offset bytes in the iovec */ + for (i = 0; offset >= iov[i].iov_len && i < iov_cnt; i++) + offset -= iov[i].iov_len; + + /* copying data */ + for (copied = 0; copied < bytes && i < iov_cnt; i++) { + size_t len = MIN(iov[i].iov_len - offset, bytes - copied); + + memcpy((char *)iov[i].iov_base + offset, (char *)buf + copied, + len); + copied += len; + offset = 0; + } + + return copied; +} + +/** + * iov_to_buf - Copy data from a scatter/gather I/O vector (struct iovec) to + * a buffer efficiently. + * + * @iov: Pointer to the array of struct iovec describing the scatter/gather + * I/O vector. + * @iov_cnt: Number of elements in the iov array. + * @offset: Offset within the first element of iov from where copying should start. + * @buf: Pointer to the destination buffer where data will be copied. + * @bytes: Total number of bytes to copy from iov to buf. + * + * Returns: The number of bytes successfully copied. + */ +size_t iov_to_buf(const struct iovec *iov, size_t iov_cnt, + size_t offset, void *buf, size_t bytes) +{ + unsigned int i; + size_t copied; + + if (__builtin_constant_p(bytes) && iov_cnt && + offset <= iov[0].iov_len && bytes <= iov[0].iov_len - offset) { + memcpy(buf, (char *)iov[0].iov_base + offset, bytes); + return bytes; + } + + /* skipping offset bytes in the iovec */ + for (i = 0; offset >= iov[i].iov_len && i < iov_cnt; i++) + offset -= iov[i].iov_len; + + /* copying data */ + for (copied = 0; copied < bytes && i < iov_cnt; i++) { + size_t len = MIN(iov[i].iov_len - offset, bytes - copied); + memcpy((char *)buf + copied, (char *)iov[i].iov_base + offset, + len); + copied += len; + offset = 0; + } + + return copied; +} + +/** + * iov_size - Calculate the total size of a scatter/gather I/O vector + * (struct iovec). + * + * @iov: Pointer to the array of struct iovec describing the + * scatter/gather I/O vector. + * @iov_cnt: Number of elements in the iov array. + * + * Returns: The total size in bytes. + */ +size_t iov_size(const struct iovec *iov, size_t iov_cnt) +{ + unsigned int i; + size_t len; + + for (i = 0, len = 0; i < iov_cnt; i++) + len += iov[i].iov_len; + + return len; +} + +/** + * iov_copy - Copy data from one scatter/gather I/O vector (struct iovec) to + * another. + * + * @dst_iov: Pointer to the destination array of struct iovec describing + * the scatter/gather I/O vector to copy to. + * @dst_iov_cnt: Number of elements in the destination iov array. + * @iov: Pointer to the source array of struct iovec describing + * the scatter/gather I/O vector to copy from. + * @iov_cnt: Number of elements in the source iov array. + * @offset: Offset within the source iov from where copying should start. + * @bytes: Total number of bytes to copy from iov to dst_iov. + * + * Returns: The number of elements successfully copied to the destination + * iov array. + */ +unsigned iov_copy(struct iovec *dst_iov, size_t dst_iov_cnt, + const struct iovec *iov, size_t iov_cnt, + size_t offset, size_t bytes) +{ + unsigned int i, j; + size_t len; + + /* skipping offset bytes in the iovec */ + for (i = 0; offset >= iov[i].iov_len && i < iov_cnt; i++) + offset -= iov[i].iov_len; + + /* copying data */ + for (j = 0; i < iov_cnt && j < dst_iov_cnt && bytes; i++) { + len = MIN(bytes, iov[i].iov_len - offset); + + dst_iov[j].iov_base = (char *)iov[i].iov_base + offset; + dst_iov[j].iov_len = len; + j++; + bytes -= len; + offset = 0; + } + + return j; +} diff --git a/iov.h b/iov.h new file mode 100644 index 000000000000..ee35a75d0870 --- /dev/null +++ b/iov.h @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * iov.c - helpers for using (partial) iovecs. + * + * Copyrigh Red Hat + * Author: Laurent Vivier + * + * This file also contains code originally from QEMU include/qemu/iov.h: + * + * Author(s): + * Amit Shah + * Michael Tokarev + */ + +#ifndef IOVEC_H +#define IOVEC_H + +#include +#include + +size_t iov_from_buf(const struct iovec *iov, size_t iov_cnt, + size_t offset, const void *buf, size_t bytes); +size_t iov_to_buf(const struct iovec *iov, size_t iov_cnt, + size_t offset, void *buf, size_t bytes); +size_t iov_size(const struct iovec *iov, size_t iov_cnt); +unsigned iov_copy(struct iovec *dst_iov, size_t dst_iov_cnt, + const struct iovec *iov, size_t iov_cnt, + size_t offset, size_t bytes); +#endif /* IOVEC_H */ -- 2.42.0