diff --git a/conf.c b/conf.c index 335f37c..c5ee07b 100644 --- a/conf.c +++ b/conf.c @@ -1413,6 +1413,7 @@ void conf(struct ctx *c, int argc, char **argv) optstring = "+dqfel:hs:F:p:P:m:a:n:M:g:i:o:D:S:H:461t:u:"; } + c->mtu = ROUND_DOWN(ETH_MAX_MTU - ETH_HLEN, sizeof(uint32_t)); c->tcp.fwd_in.mode = c->tcp.fwd_out.mode = FWD_UNSET; c->udp.fwd_in.mode = c->udp.fwd_out.mode = FWD_UNSET; memcpy(c->our_tap_mac, MAC_OUR_LAA, ETH_ALEN); @@ -1662,12 +1663,7 @@ void conf(struct ctx *c, int argc, char **argv) if (errno || *e) die("Invalid MTU: %s", optarg); - if (!mtu) { - c->mtu = -1; - break; - } - - if (mtu < ETH_MIN_MTU || mtu > ETH_MAX_MTU) { + if (mtu && (mtu < ETH_MIN_MTU || mtu > ETH_MAX_MTU)) { die("MTU %lu out of range (%u..%u)", mtu, ETH_MIN_MTU, ETH_MAX_MTU); } @@ -1980,9 +1976,6 @@ void conf(struct ctx *c, int argc, char **argv) c->no_dhcpv6 = 1; } - if (!c->mtu) - c->mtu = ROUND_DOWN(ETH_MAX_MTU - ETH_HLEN, sizeof(uint32_t)); - get_dns(c); if (!*c->pasta_ifn) { diff --git a/dhcp.c b/dhcp.c index 4a209f1..66a716e 100644 --- a/dhcp.c +++ b/dhcp.c @@ -417,7 +417,7 @@ int dhcp(const struct ctx *c, const struct pool *p) &c->ip4.guest_gw, sizeof(c->ip4.guest_gw)); } - if (c->mtu != -1) { + if (c->mtu) { opts[26].slen = 2; opts[26].s[0] = c->mtu / 256; opts[26].s[1] = c->mtu % 256; diff --git a/ndp.c b/ndp.c index 37bf7a3..ded2081 100644 --- a/ndp.c +++ b/ndp.c @@ -256,7 +256,7 @@ static void ndp_ra(const struct ctx *c, const struct in6_addr *dst) ptr = &ra.var[0]; - if (c->mtu != -1) { + if (c->mtu) { struct opt_mtu *mtu = (struct opt_mtu *)ptr; *mtu = (struct opt_mtu) { .header = { diff --git a/passt.h b/passt.h index 1f0dab5..28d1389 100644 --- a/passt.h +++ b/passt.h @@ -274,6 +274,8 @@ struct ctx { int fd_repair; unsigned char our_tap_mac[ETH_ALEN]; unsigned char guest_mac[ETH_ALEN]; + uint16_t mtu; + uint64_t hash_secret[2]; int ifi4; @@ -298,7 +300,6 @@ struct ctx { int no_icmp; struct icmp_ctx icmp; - int mtu; int no_dns; int no_dns_search; int no_dhcp_dns; diff --git a/pasta.c b/pasta.c index 585a51c..fa3e7de 100644 --- a/pasta.c +++ b/pasta.c @@ -319,7 +319,7 @@ void pasta_ns_conf(struct ctx *c) if (c->pasta_conf_ns) { unsigned int flags = IFF_UP; - if (c->mtu != -1) + if (c->mtu) nl_link_set_mtu(nl_sock_ns, c->pasta_ifi, c->mtu); if (c->ifi6) /* Avoid duplicate address detection on link up */ diff --git a/tcp.c b/tcp.c index f498f5b..e3c0a53 100644 --- a/tcp.c +++ b/tcp.c @@ -1139,7 +1139,7 @@ int tcp_prepare_flags(const struct ctx *c, struct tcp_tap_conn *conn, if (flags & SYN) { int mss; - if (c->mtu == -1) { + if (!c->mtu) { mss = tinfo.tcpi_snd_mss; } else { mss = c->mtu - sizeof(struct tcphdr);