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 ABDC85A026B for ; Thu, 17 Nov 2022 00:54:14 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668642853; 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=ivPhAxZ6C/9pUbCWsQDhtdZ+pYaMCUGB4itt+UgsRqQ=; b=SMj4A8XpaHKCiis262yTdCKz5Pryhd9sQY2WHvTvu2jK8SmCMXzk3Tu2d2wZYxYXpZmim1 ne4yqiZxFx1Q7Hyvlhvur6QqDyEfWq0Dl5PX18LQIw323uon6q58VN6/mB0gPeKu62Qo94 yOP1bznR1KMlpph4kzGmqODG6jXQea8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-344-UGiIH18fO66YI-z7mjc2Pw-1; Wed, 16 Nov 2022 18:54:12 -0500 X-MC-Unique: UGiIH18fO66YI-z7mjc2Pw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id ADF78811E7A; Wed, 16 Nov 2022 23:54:11 +0000 (UTC) Received: from maya.cloud.tilaa.com (ovpn-208-8.brq.redhat.com [10.40.208.8]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4CD49140EBF3; Wed, 16 Nov 2022 23:54:11 +0000 (UTC) Date: Thu, 17 Nov 2022 00:54:08 +0100 From: Stefano Brivio To: David Gibson Subject: Re: [PATCH 19/32] inany: Helper functions for handling addresses which could be IPv4 or IPv6 Message-ID: <20221117005408.0f99d1e3@elisabeth> In-Reply-To: <20221116044212.3876516-20-david@gibson.dropbear.id.au> References: <20221116044212.3876516-1-david@gibson.dropbear.id.au> <20221116044212.3876516-20-david@gibson.dropbear.id.au> Organization: Red Hat MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-ID-Hash: BCB375F6ZJHSFEUK6QHQZMWMNU4KR6O7 X-Message-ID-Hash: BCB375F6ZJHSFEUK6QHQZMWMNU4KR6O7 X-MailFrom: sbrivio@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: passt-dev@passt.top X-Mailman-Version: 3.3.3 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: [Reviewed until 25/32 so far] On Wed, 16 Nov 2022 15:41:59 +1100 David Gibson wrote: > struct tcp_conn stores an address which could be IPv6 or IPv4 using a > union. We can do this without an additional tag by encoding IPv4 addresses > as IPv4-mapped IPv6 addresses. > > This approach is useful wider than the specific place in tcp_conn, so > expose a new 'union inany_addr' like this from a new inany.h. Along with > that create a number of helper functions to make working with these "inany" > addresses easier. > > Signed-off-by: David Gibson > --- > Makefile | 6 ++-- > inany.h | 68 ++++++++++++++++++++++++++++++++++++++++ > tcp.c | 88 +++++++++++++++++++++++++--------------------------- > tcp_conn.h | 15 ++------- > tcp_splice.c | 1 + > 5 files changed, 117 insertions(+), 61 deletions(-) > create mode 100644 inany.h > > diff --git a/Makefile b/Makefile > index 9046b0b..ca453aa 100644 > --- a/Makefile > +++ b/Makefile > @@ -44,9 +44,9 @@ 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 icmp.h \ > - isolation.h lineread.h log.h ndp.h netlink.h packet.h passt.h pasta.h \ > - pcap.h port_fwd.h siphash.h tap.h tcp.h tcp_conn.h tcp_splice.h udp.h \ > - util.h > + inany.h isolation.h lineread.h log.h ndp.h netlink.h packet.h passt.h \ > + pasta.h pcap.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 > > # On gcc 11 and 12, with -O2 and -flto, tcp_hash() and siphash_20b(), if > diff --git a/inany.h b/inany.h > new file mode 100644 > index 0000000..4e53da9 > --- /dev/null > +++ b/inany.h > @@ -0,0 +1,68 @@ > +/* SPDX-License-Identifier: AGPL-3.0-or-later > + * Copyright Red Hat > + * Author: David Gibson > + * > + * inany.h - Types and helpers for handling addresses which could be > + * IPv6 or IPv4 (encoded as IPv4-mapped IPv6 addresses) > + */ > + > +#include > + > +/** union inany_addr - Represents either an IPv4 or IPv6 address > + * @a6: Address as an IPv6 address, may be IPv4-mapped > + * @_v4._zero: All zero-bits for an IPv4 address > + * @_v4._one: All one-bits for an IPv4 address > + * @_v4.a4: If @a6 is an IPv4 mapped address, this is the raw IPv4 address > + * > + * Fields starting with _ shouldn't be accessed except via helpers. > + */ > +union inany_addr { > + struct in6_addr a6; > + struct { > + uint8_t _zero[10]; > + uint8_t _one[2]; > + struct in_addr a4; > + } _v4mapped; I'm not sure the extra _ are really worth it. I mean, that's not really enforceable, so saying that v4mapped should only be accessed by helpers should be equivalent. > +}; > + > +/** inany_v4 - Extract IPv4 address, if present, from IPv[46] address > + * @addr: IPv4 or IPv6 address > + * > + * Return: IPv4 address if @addr is IPv4, NULL otherwise > + */ > +static inline const struct in_addr *inany_v4(const union inany_addr *addr) > +{ > + if (!IN6_IS_ADDR_V4MAPPED(&addr->a6)) > + return NULL; > + return &addr->_v4mapped.a4; > +} > + > +/** inany_equals - Compare two IPv[46] addresses > + * @a, @b: IPv[46] addresses > + * > + * Return: true if @a and @b are the same address > + */ > +static inline bool inany_equals(const union inany_addr *a, > + const union inany_addr *b) > +{ > + return IN6_ARE_ADDR_EQUAL(&a->a6, &b->a6); > +} > + > +/** inany_from_af - Set IPv[46] address from IPv4 or IPv6 address > + * @aa: Pointer to store IPv[46] address > + * @af: Address family of @addr > + * @addr: struct in_addr (IPv4) or struct in6_addr (IPv6) > + */ > +static inline void inany_from_af(union inany_addr *aa, int af, const void *addr) > +{ > + if (af == AF_INET6) { > + aa->a6 = *((struct in6_addr *)addr); > + } else if (af == AF_INET) { > + memset(&aa->_v4mapped._zero, 0, sizeof(aa->_v4mapped._zero)); > + memset(&aa->_v4mapped._one, 0xff, sizeof(aa->_v4mapped._one)); > + aa->_v4mapped.a4 = *((struct in_addr *)addr); > + } else { > + /* Not valid to call with other address families */ > + assert(0); > + } > +} > diff --git a/tcp.c b/tcp.c > index 7686766..4040198 100644 > --- a/tcp.c > +++ b/tcp.c > @@ -301,6 +301,7 @@ > #include "conf.h" > #include "tcp_splice.h" > #include "log.h" > +#include "inany.h" > > #include "tcp_conn.h" > > @@ -404,7 +405,7 @@ struct tcp6_l2_head { /* For MSS6 macro: keep in sync with tcp6_l2_buf_t */ > #define OPT_SACK 5 > #define OPT_TS 8 > > -#define CONN_V4(conn) IN6_IS_ADDR_V4MAPPED(&conn->a.a6) > +#define CONN_V4(conn) (!!inany_v4(&(conn)->addr)) > #define CONN_V6(conn) (!CONN_V4(conn)) > #define CONN_IS_CLOSING(conn) \ > ((conn->events & ESTABLISHED) && \ > @@ -438,7 +439,7 @@ static int tcp_sock_init_ext [NUM_PORTS][IP_VERSIONS]; > static int tcp_sock_ns [NUM_PORTS][IP_VERSIONS]; > > /* Table of destinations with very low RTT (assumed to be local), LRU */ > -static struct in6_addr low_rtt_dst[LOW_RTT_TABLE_SIZE]; > +static union inany_addr low_rtt_dst[LOW_RTT_TABLE_SIZE]; > > /* Static buffers */ > > @@ -861,7 +862,7 @@ static int tcp_rtt_dst_low(const struct tcp_tap_conn *conn) > int i; > > for (i = 0; i < LOW_RTT_TABLE_SIZE; i++) > - if (IN6_ARE_ADDR_EQUAL(&conn->a.a6, low_rtt_dst + i)) > + if (inany_equals(&conn->addr, low_rtt_dst + i)) > return 1; > > return 0; > @@ -883,7 +884,7 @@ static void tcp_rtt_dst_check(const struct tcp_tap_conn *conn, > return; > > for (i = 0; i < LOW_RTT_TABLE_SIZE; i++) { > - if (IN6_ARE_ADDR_EQUAL(&conn->a.a6, low_rtt_dst + i)) > + if (inany_equals(&conn->addr, low_rtt_dst + i)) > return; > if (hole == -1 && IN6_IS_ADDR_UNSPECIFIED(low_rtt_dst + i)) > hole = i; > @@ -895,10 +896,10 @@ static void tcp_rtt_dst_check(const struct tcp_tap_conn *conn, > if (hole == -1) > return; > > - memcpy(low_rtt_dst + hole++, &conn->a.a6, sizeof(conn->a.a6)); > + low_rtt_dst[hole++] = conn->addr; > if (hole == LOW_RTT_TABLE_SIZE) > hole = 0; > - memcpy(low_rtt_dst + hole, &in6addr_any, sizeof(conn->a.a6)); > + inany_from_af(low_rtt_dst + hole, AF_INET6, &in6addr_any); > #else > (void)conn; > (void)tinfo; > @@ -1187,13 +1188,14 @@ static int tcp_hash_match(const struct tcp_tap_conn *conn, > int af, const void *addr, > in_port_t tap_port, in_port_t sock_port) > { > - if (af == AF_INET && CONN_V4(conn) && > - !memcmp(&conn->a.a4.a, addr, sizeof(conn->a.a4.a)) && > + const struct in_addr *a4 = inany_v4(&conn->addr); > + > + if (af == AF_INET && a4 && !memcmp(a4, addr, sizeof(*a4)) && > conn->tap_port == tap_port && conn->sock_port == sock_port) > return 1; > > if (af == AF_INET6 && > - IN6_ARE_ADDR_EQUAL(&conn->a.a6, addr) && > + IN6_ARE_ADDR_EQUAL(&conn->addr.a6, addr) && > conn->tap_port == tap_port && conn->sock_port == sock_port) > return 1; Note to self or other reviewers: switch to inany_equals() in 22/32. -- Stefano