From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: passt.top; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=HF7McDua; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by passt.top (Postfix) with ESMTPS id 6C5EF5A027E for ; Thu, 14 Aug 2025 11:49:03 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1755164942; 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=JmgzKBWWDD+6Y+6ClLnjAipq7L3GNK2zIlx5PHtXyWo=; b=HF7McDuaE6f70pcs9os4Ed6BtBNJRcKZciuOgTis3MdqpmfzEnXzPCZm/qYp4NfKFUtPNe I76SVxQkfifKgYc3RUdXCmtV24+Qur/NLSotNFZm5msbQtv9BdCzsk4FumotqSEC+lQj2Q N5nNQX8beRiqdEr6QXp46Qh6pXzbL6U= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-679-mI8kxyxZPymKq_giKUMSsQ-1; Thu, 14 Aug 2025 05:49:00 -0400 X-MC-Unique: mI8kxyxZPymKq_giKUMSsQ-1 X-Mimecast-MFC-AGG-ID: mI8kxyxZPymKq_giKUMSsQ_1755164939 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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 mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id BB4A71955F1F for ; Thu, 14 Aug 2025 09:48:59 +0000 (UTC) Received: from lenovo-t14s.redhat.com (unknown [10.45.225.81]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id AB9721800280; Thu, 14 Aug 2025 09:48:58 +0000 (UTC) From: Laurent Vivier To: passt-dev@passt.top Subject: [PATCH v10 03/30] iov: Update IOV_REMOVE_HEADER() and IOV_PEEK_HEADER() Date: Thu, 14 Aug 2025 11:48:22 +0200 Message-ID: <20250814094849.919709-4-lvivier@redhat.com> In-Reply-To: <20250814094849.919709-1-lvivier@redhat.com> References: <20250814094849.919709-1-lvivier@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: r76Iu-Ci07nS3Rpy253q_Q2zvyM8xS5rM_RyJwOOgvU_1755164939 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit content-type: text/plain; charset="US-ASCII"; x-default=true Message-ID-Hash: ZECEFEE2XZICTOAKRFA6H2KFU2T5LHJN X-Message-ID-Hash: ZECEFEE2XZICTOAKRFA6H2KFU2T5LHJN 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: Provide a temporary variable of the wanted type to store the header if the memory in the iovec array is not contiguous. Signed-off-by: Laurent Vivier --- iov.c | 53 ++++++++++++++++++++++++++++++++++++++++++++--------- iov.h | 35 +++++++++++++++++++++-------------- tcp_buf.c | 2 +- 3 files changed, 66 insertions(+), 24 deletions(-) diff --git a/iov.c b/iov.c index 9a91eb63026a..d20fbb854933 100644 --- a/iov.c +++ b/iov.c @@ -109,7 +109,7 @@ size_t iov_from_buf(const struct iovec *iov, size_t iov_cnt, * * Return: the number of bytes successfully copied. */ -/* cppcheck-suppress unusedFunction */ +/* cppcheck-suppress [staticFunction] */ size_t iov_to_buf(const struct iovec *iov, size_t iov_cnt, size_t offset, void *buf, size_t bytes) { @@ -127,6 +127,7 @@ size_t iov_to_buf(const struct iovec *iov, size_t iov_cnt, /* copying data */ for (copied = 0; copied < bytes && i < iov_cnt; i++) { size_t len = MIN(iov[i].iov_len - offset, bytes - copied); + ASSERT(iov[i].iov_base); memcpy((char *)buf + copied, (char *)iov[i].iov_base + offset, len); copied += len; @@ -208,7 +209,7 @@ bool iov_drop_header(struct iov_tail *tail, size_t len) } /** - * iov_peek_header_() - Get pointer to a header from an IOV tail + * iov_check_header() - Check if a header can be accessed * @tail: IOV tail to get header from * @len: Length of header to get, in bytes * @align: Required alignment of header, in bytes @@ -219,8 +220,7 @@ bool iov_drop_header(struct iov_tail *tail, size_t len) * overruns the IO vector, is not contiguous or doesn't have the * requested alignment. */ -/* cppcheck-suppress [staticFunction,unmatchedSuppression] */ -void *iov_peek_header_(struct iov_tail *tail, size_t len, size_t align) +static void *iov_check_header(struct iov_tail *tail, size_t len, size_t align) { char *p; @@ -240,27 +240,62 @@ void *iov_peek_header_(struct iov_tail *tail, size_t len, size_t align) return p; } +/** + * iov_peek_header_() - Get pointer to a header from an IOV tail + * @tail: IOV tail to get header from + * @v: Temporary memory to use if the memory in @tail + * is discontinuous + * @len: Length of header to get, in bytes + * @align: Required alignment of header, in bytes + * + * @tail may be pruned, but will represent the same bytes as before. + * + * Return: pointer to the first @len logical bytes of the tail, or to + * a copy if that overruns the IO vector, is not contiguous or + * doesn't have the requested alignment. NULL if that overruns the + * IO vector. + */ +/* cppcheck-suppress [staticFunction,unmatchedSuppression] */ +void *iov_peek_header_(struct iov_tail *tail, void *v, size_t len, size_t align) +{ + char *p = iov_check_header(tail, len, align); + size_t l; + + if (p) + return p; + + l = iov_to_buf(tail->iov, tail->cnt, tail->off, v, len); + if (l != len) + return NULL; + + return v; +} + /** * iov_remove_header_() - Remove a header from an IOV tail * @tail: IOV tail to remove header from (modified) + * @v: Temporary memory to use if the memory in @tail + * is discontinuous * @len: Length of header to remove, in bytes * @align: Required alignment of header, in bytes * * On success, @tail is updated so that it longer includes the bytes of the * returned header. * - * Return: pointer to the first @len logical bytes of the tail, NULL if that - * overruns the IO vector, is not contiguous or doesn't have the - * requested alignment. + * Return: pointer to the first @len logical bytes of the tail, or to + * a copy if that overruns the IO vector, is not contiguous or + * doesn't have the requested alignment. NULL if that overruns the + * IO vector. */ -void *iov_remove_header_(struct iov_tail *tail, size_t len, size_t align) +void *iov_remove_header_(struct iov_tail *tail, void *v, size_t len, size_t align) { - char *p = iov_peek_header_(tail, len, align); + char *p = iov_peek_header_(tail, v, len, align); if (!p) return NULL; tail->off = tail->off + len; + return p; } diff --git a/iov.h b/iov.h index c94fabe1eb43..1821b40b1cb5 100644 --- a/iov.h +++ b/iov.h @@ -73,38 +73,45 @@ struct iov_tail { bool iov_tail_prune(struct iov_tail *tail); size_t iov_tail_size(struct iov_tail *tail); bool iov_drop_header(struct iov_tail *tail, size_t len); -void *iov_peek_header_(struct iov_tail *tail, size_t len, size_t align); -void *iov_remove_header_(struct iov_tail *tail, size_t len, size_t align); +void *iov_peek_header_(struct iov_tail *tail, void *v, size_t len, size_t align); +void *iov_remove_header_(struct iov_tail *tail, void *v, size_t len, size_t align); ssize_t iov_tail_clone(struct iovec *dst_iov, size_t dst_iov_cnt, struct iov_tail *tail); /** * IOV_PEEK_HEADER() - Get typed pointer to a header from an IOV tail * @tail_: IOV tail to get header from - * @type_: Data type of the header + * @var_: Temporary buffer of the type of the header to use if + * the memory in the iovec array is not contiguous. * * @tail_ may be pruned, but will represent the same bytes as before. * - * Return: pointer of type (@type_ *) located at the start of @tail_, NULL if - * we can't get a contiguous and aligned pointer. + * Return: pointer of type (@type_ *) located at the start of @tail_ + * or to @var_ if iovec memory is not contiguous, NULL if + * that overruns the iovec. */ -#define IOV_PEEK_HEADER(tail_, type_) \ - ((type_ *)(iov_peek_header_((tail_), \ - sizeof(type_), __alignof__(type_)))) + +#define IOV_PEEK_HEADER(tail_, var_) \ + ((__typeof__(var_) *)(iov_peek_header_((tail_), &(var_), \ + sizeof(var_), \ + __alignof__(var_)))) /** * IOV_REMOVE_HEADER() - Remove and return typed header from an IOV tail * @tail_: IOV tail to remove header from (modified) - * @type_: Data type of the header to remove + * @var_: Temporary buffer of the type of the header to use if + * the memory in the iovec array is not contiguous. * * On success, @tail_ is updated so that it longer includes the bytes of the * returned header. * - * Return: pointer of type (@type_ *) located at the old start of @tail_, NULL - * if we can't get a contiguous and aligned pointer. + * Return: pointer of type (@type_ *) located at the start of @tail_ + * or to @var_ if iovec memory is not contiguous, NULL if + * that overruns the iovec. */ -#define IOV_REMOVE_HEADER(tail_, type_) \ - ((type_ *)(iov_remove_header_((tail_), \ - sizeof(type_), __alignof__(type_)))) + +#define IOV_REMOVE_HEADER(tail_, var_) \ + ((__typeof__(var_) *)(iov_remove_header_((tail_), &(var_), \ + sizeof(var_), __alignof__(var_)))) #endif /* IOVEC_H */ diff --git a/tcp_buf.c b/tcp_buf.c index d1fca676c9a7..bc898de86919 100644 --- a/tcp_buf.c +++ b/tcp_buf.c @@ -160,7 +160,7 @@ static void tcp_l2_buf_fill_headers(const struct tcp_tap_conn *conn, uint32_t seq, bool no_tcp_csum) { struct iov_tail tail = IOV_TAIL(&iov[TCP_IOV_PAYLOAD], 1, 0); - struct tcphdr *th = IOV_REMOVE_HEADER(&tail, struct tcphdr); + struct tcphdr th_storage, *th = IOV_REMOVE_HEADER(&tail, th_storage); struct tap_hdr *taph = iov[TCP_IOV_TAP].iov_base; const struct flowside *tapside = TAPFLOW(conn); const struct in_addr *a4 = inany_v4(&tapside->oaddr); -- 2.49.0