From ca69c3f1964846b27f8333cd06f7594289cbf53b Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 17 Nov 2022 16:58:55 +1100 Subject: inany: Helper functions for handling addresses which could be IPv4 or IPv6 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 Signed-off-by: Stefano Brivio --- tcp.c | 88 +++++++++++++++++++++++++++++++++---------------------------------- 1 file changed, 43 insertions(+), 45 deletions(-) (limited to 'tcp.c') diff --git a/tcp.c b/tcp.c index e9803aa..d1008ae 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; @@ -1253,11 +1255,13 @@ static unsigned int tcp_hash(const struct ctx *c, int af, const void *addr, static unsigned int tcp_conn_hash(const struct ctx *c, const struct tcp_tap_conn *conn) { - if (CONN_V6(conn)) - return tcp_hash(c, AF_INET6, &conn->a.a6, + const struct in_addr *a4 = inany_v4(&conn->addr); + + if (a4) + return tcp_hash(c, AF_INET, a4, conn->tap_port, conn->sock_port); else - return tcp_hash(c, AF_INET, &conn->a.a4.a, + return tcp_hash(c, AF_INET6, &conn->addr.a6, conn->tap_port, conn->sock_port); } @@ -1582,6 +1586,7 @@ static size_t tcp_l2_buf_fill_headers(const struct ctx *c, void *p, size_t plen, const uint16_t *check, uint32_t seq) { + const struct in_addr *a4 = inany_v4(&conn->addr); size_t ip_len, eth_len; #define SET_TCP_HEADER_COMMON_V4_V6(b, conn, seq) \ @@ -1599,13 +1604,33 @@ do { \ } \ } while (0) - if (CONN_V6(conn)) { + if (a4) { + struct tcp4_l2_buf_t *b = (struct tcp4_l2_buf_t *)p; + + ip_len = plen + sizeof(struct iphdr) + sizeof(struct tcphdr); + b->iph.tot_len = htons(ip_len); + b->iph.saddr = a4->s_addr; + b->iph.daddr = c->ip4.addr_seen.s_addr; + + if (check) + b->iph.check = *check; + else + tcp_update_check_ip4(b); + + SET_TCP_HEADER_COMMON_V4_V6(b, conn, seq); + + tcp_update_check_tcp4(b); + + eth_len = ip_len + sizeof(struct ethhdr); + if (c->mode == MODE_PASST) + b->vnet_len = htonl(eth_len); + } else { struct tcp6_l2_buf_t *b = (struct tcp6_l2_buf_t *)p; ip_len = plen + sizeof(struct ipv6hdr) + sizeof(struct tcphdr); b->ip6h.payload_len = htons(plen + sizeof(struct tcphdr)); - b->ip6h.saddr = conn->a.a6; + b->ip6h.saddr = conn->addr.a6; if (IN6_IS_ADDR_LINKLOCAL(&b->ip6h.saddr)) b->ip6h.daddr = c->ip6.addr_ll_seen; else @@ -1621,26 +1646,6 @@ do { \ b->ip6h.flow_lbl[1] = (conn->sock >> 8) & 0xff; b->ip6h.flow_lbl[2] = (conn->sock >> 0) & 0xff; - eth_len = ip_len + sizeof(struct ethhdr); - if (c->mode == MODE_PASST) - b->vnet_len = htonl(eth_len); - } else { - struct tcp4_l2_buf_t *b = (struct tcp4_l2_buf_t *)p; - - ip_len = plen + sizeof(struct iphdr) + sizeof(struct tcphdr); - b->iph.tot_len = htons(ip_len); - b->iph.saddr = conn->a.a4.a.s_addr; - b->iph.daddr = c->ip4.addr_seen.s_addr; - - if (check) - b->iph.check = *check; - else - tcp_update_check_ip4(b); - - SET_TCP_HEADER_COMMON_V4_V6(b, conn, seq); - - tcp_update_check_tcp4(b); - eth_len = ip_len + sizeof(struct ethhdr); if (c->mode == MODE_PASST) b->vnet_len = htonl(eth_len); @@ -2144,18 +2149,14 @@ static void tcp_conn_from_tap(struct ctx *c, int af, const void *addr, if (!(conn->wnd_from_tap = (htons(th->window) >> conn->ws_from_tap))) conn->wnd_from_tap = 1; + inany_from_af(&conn->addr, af, addr); + if (af == AF_INET) { sa = (struct sockaddr *)&addr4; sl = sizeof(addr4); - - memset(&conn->a.a4.zero, 0, sizeof(conn->a.a4.zero)); - memset(&conn->a.a4.one, 0xff, sizeof(conn->a.a4.one)); - memcpy(&conn->a.a4.a, addr, sizeof(conn->a.a4.a)); } else { sa = (struct sockaddr *)&addr6; sl = sizeof(addr6); - - memcpy(&conn->a.a6, addr, sizeof(conn->a.a6)); } conn->sock_port = ntohs(th->dest); @@ -2808,7 +2809,7 @@ static void tcp_tap_conn_from_sock(struct ctx *c, union epoll_ref ref, memcpy(&sa6.sin6_addr, src, sizeof(*src)); } - memcpy(&conn->a.a6, &sa6.sin6_addr, sizeof(conn->a.a6)); + inany_from_af(&conn->addr, AF_INET6, &sa6.sin6_addr); conn->sock_port = ntohs(sa6.sin6_port); conn->tap_port = ref.r.p.tcp.tcp.index; @@ -2824,15 +2825,12 @@ static void tcp_tap_conn_from_sock(struct ctx *c, union epoll_ref ref, memcpy(&sa4, sa, sizeof(sa4)); - memset(&conn->a.a4.zero, 0, sizeof(conn->a.a4.zero)); - memset(&conn->a.a4.one, 0xff, sizeof(conn->a.a4.one)); - if (IN4_IS_ADDR_LOOPBACK(&sa4.sin_addr) || IN4_IS_ADDR_UNSPECIFIED(&sa4.sin_addr) || IN4_ARE_ADDR_EQUAL(&sa4.sin_addr, &c->ip4.addr_seen)) sa4.sin_addr = c->ip4.gw; - conn->a.a4.a = sa4.sin_addr; + inany_from_af(&conn->addr, AF_INET, &sa4.sin_addr); conn->sock_port = ntohs(sa4.sin_port); conn->tap_port = ref.r.p.tcp.tcp.index; -- cgit v1.2.3