On Thu, Nov 17, 2022 at 12:54:08AM +0100, Stefano Brivio wrote: > [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. Fair call. Adjusted. > > > +}; > > + > > +/** 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. > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson