From 78a5822820f9356bcd3bd8824186dd953c33028b Mon Sep 17 00:00:00 2001 From: Alejandro Zeise Date: Tue, 8 Oct 2024 09:57:13 +0200 Subject: [PATCH] util/iov: Introduce iov_send_recv_with_flags() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In order to support a new update function, a flag needs to be passed to the kernel via the socket send call (MSG_MORE) to notify it that more data is to be expected to calculate the hash correctly. Add a new iov helper for this purpose. Signed-off-by: Alejandro Zeise [ clg: - Split iov changes from original patch - Checkpatch fixes ] Signed-off-by: Cédric Le Goater Reviewed-by: Daniel P. Berrangé Signed-off-by: Daniel P. Berrangé --- include/qemu/iov.h | 27 +++++++++++++++++++++++++++ util/iov.c | 25 ++++++++++++++++++------- 2 files changed, 45 insertions(+), 7 deletions(-) diff --git a/include/qemu/iov.h b/include/qemu/iov.h index 63a1c01965..44f9db5cee 100644 --- a/include/qemu/iov.h +++ b/include/qemu/iov.h @@ -1,6 +1,7 @@ /* * Helpers for using (partial) iovecs. * + * Copyright (c) 2024 Seagate Technology LLC and/or its Affiliates * Copyright (C) 2010 Red Hat, Inc. * * Author(s): @@ -75,6 +76,32 @@ iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt, size_t iov_memset(const struct iovec *iov, const unsigned int iov_cnt, size_t offset, int fillc, size_t bytes); +/* + * Send/recv data from/to iovec buffers directly, with the provided + * socket flags. + * + * `offset' bytes in the beginning of iovec buffer are skipped and + * next `bytes' bytes are used, which must be within data of iovec. + * + * r = iov_send_recv_with_flags(sockfd, sockflags, iov, iovcnt, + * offset, bytes, true); + * + * is logically equivalent to + * + * char *buf = malloc(bytes); + * iov_to_buf(iov, iovcnt, offset, buf, bytes); + * r = send(sockfd, buf, bytes, sockflags); + * free(buf); + * + * For iov_send_recv_with_flags() _whole_ area being sent or received + * should be within the iovec, not only beginning of it. + */ +ssize_t iov_send_recv_with_flags(int sockfd, int sockflags, + const struct iovec *iov, + unsigned iov_cnt, size_t offset, + size_t bytes, + bool do_send); + /* * Send/recv data from/to iovec buffers directly * diff --git a/util/iov.c b/util/iov.c index 7e73948f5e..7777116123 100644 --- a/util/iov.c +++ b/util/iov.c @@ -3,6 +3,7 @@ * * Copyright IBM, Corp. 2007, 2008 * Copyright (C) 2010 Red Hat, Inc. + * Copyright (c) 2024 Seagate Technology LLC and/or its Affiliates * * Author(s): * Anthony Liguori @@ -92,7 +93,8 @@ size_t iov_size(const struct iovec *iov, const unsigned int iov_cnt) /* helper function for iov_send_recv() */ static ssize_t -do_send_recv(int sockfd, struct iovec *iov, unsigned iov_cnt, bool do_send) +do_send_recv(int sockfd, int flags, struct iovec *iov, unsigned iov_cnt, + bool do_send) { #ifdef CONFIG_POSIX ssize_t ret; @@ -102,8 +104,8 @@ do_send_recv(int sockfd, struct iovec *iov, unsigned iov_cnt, bool do_send) msg.msg_iovlen = iov_cnt; do { ret = do_send - ? sendmsg(sockfd, &msg, 0) - : recvmsg(sockfd, &msg, 0); + ? sendmsg(sockfd, &msg, flags) + : recvmsg(sockfd, &msg, flags); } while (ret < 0 && errno == EINTR); return ret; #else @@ -114,8 +116,8 @@ do_send_recv(int sockfd, struct iovec *iov, unsigned iov_cnt, bool do_send) ssize_t off = 0; while (i < iov_cnt) { ssize_t r = do_send - ? send(sockfd, iov[i].iov_base + off, iov[i].iov_len - off, 0) - : recv(sockfd, iov[i].iov_base + off, iov[i].iov_len - off, 0); + ? send(sockfd, iov[i].iov_base + off, iov[i].iov_len - off, flags) + : recv(sockfd, iov[i].iov_base + off, iov[i].iov_len - off, flags); if (r > 0) { ret += r; off += r; @@ -144,6 +146,15 @@ do_send_recv(int sockfd, struct iovec *iov, unsigned iov_cnt, bool do_send) ssize_t iov_send_recv(int sockfd, const struct iovec *_iov, unsigned iov_cnt, size_t offset, size_t bytes, bool do_send) +{ + return iov_send_recv_with_flags(sockfd, 0, _iov, iov_cnt, offset, bytes, + do_send); +} + +ssize_t iov_send_recv_with_flags(int sockfd, int sockflags, + const struct iovec *_iov, + unsigned iov_cnt, size_t offset, + size_t bytes, bool do_send) { ssize_t total = 0; ssize_t ret; @@ -192,11 +203,11 @@ ssize_t iov_send_recv(int sockfd, const struct iovec *_iov, unsigned iov_cnt, assert(iov[niov].iov_len > tail); orig_len = iov[niov].iov_len; iov[niov++].iov_len = tail; - ret = do_send_recv(sockfd, iov, niov, do_send); + ret = do_send_recv(sockfd, sockflags, iov, niov, do_send); /* Undo the changes above before checking for errors */ iov[niov-1].iov_len = orig_len; } else { - ret = do_send_recv(sockfd, iov, niov, do_send); + ret = do_send_recv(sockfd, sockflags, iov, niov, do_send); } if (offset) { iov[0].iov_base -= offset;