From b93d025d50dcc2c058b9eb3b67b76da56d27fcba Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 5 Jan 2023 15:26:25 +1100 Subject: [PATCH] udp: Don't use separate sockets to listen for spliced packets Currently, when ports are forwarded inbound in pasta mode, we open two sockets for incoming traffic: one listens on the public IP address and will forward packets to the tuntap interface. The other listens on localhost and forwards via "splicing" (resending directly via sockets in the ns). Now that we've improved the logic about whether we "splice" any individual packet, we don't need this. Instead we can have a single socket bound to 0.0.0.0 or ::, marked as able to splice and udp_sock_handler() will deal with each packet as appropriate. Signed-off-by: David Gibson Signed-off-by: Stefano Brivio --- udp.c | 53 +++++++++++++---------------------------------------- 1 file changed, 13 insertions(+), 40 deletions(-) diff --git a/udp.c b/udp.c index 3f216ed..dbfdb61 100644 --- a/udp.c +++ b/udp.c @@ -1124,7 +1124,6 @@ void udp_sock_init(const struct ctx *c, int ns, sa_family_t af, const void *addr, const char *ifname, in_port_t port) { union udp_epoll_ref uref = { .u32 = 0 }; - const void *bind_addr; int s; if (ns) { @@ -1136,67 +1135,41 @@ void udp_sock_init(const struct ctx *c, int ns, sa_family_t af, } if ((af == AF_INET || af == AF_UNSPEC) && c->ifi4) { - if (!addr && c->mode == MODE_PASTA) - bind_addr = &c->ip4.addr; - else - bind_addr = addr; - uref.udp.v6 = 0; + uref.udp.splice = (c->mode == MODE_PASTA); + uref.udp.orig = true; if (!ns) { - uref.udp.splice = 0; - s = sock_l4(c, AF_INET, IPPROTO_UDP, bind_addr, ifname, + s = sock_l4(c, AF_INET, IPPROTO_UDP, addr, ifname, port, uref.u32); udp_tap_map[V4][uref.udp.port].sock = s; - - if (c->mode == MODE_PASTA) { - bind_addr = &(uint32_t){ htonl(INADDR_LOOPBACK) }; - uref.udp.splice = uref.udp.orig = true; - - s = sock_l4(c, AF_INET, IPPROTO_UDP, bind_addr, - ifname, port, uref.u32); - udp_splice_init[V4][port].sock = s; - } + udp_splice_init[V4][port].sock = s; } else { - uref.udp.splice = uref.udp.orig = uref.udp.ns = true; + struct in_addr loopback = { htonl(INADDR_LOOPBACK) }; + uref.udp.ns = true; - bind_addr = &(uint32_t){ htonl(INADDR_LOOPBACK) }; - - s = sock_l4(c, AF_INET, IPPROTO_UDP, bind_addr, + s = sock_l4(c, AF_INET, IPPROTO_UDP, &loopback, ifname, port, uref.u32); udp_splice_ns[V4][port].sock = s; } } if ((af == AF_INET6 || af == AF_UNSPEC) && c->ifi6) { - if (!addr && c->mode == MODE_PASTA) - bind_addr = &c->ip6.addr; - else - bind_addr = addr; - uref.udp.v6 = 1; + uref.udp.splice = (c->mode == MODE_PASTA); + uref.udp.orig = true; if (!ns) { - uref.udp.splice = 0; - s = sock_l4(c, AF_INET6, IPPROTO_UDP, bind_addr, ifname, + s = sock_l4(c, AF_INET6, IPPROTO_UDP, addr, ifname, port, uref.u32); udp_tap_map[V6][uref.udp.port].sock = s; - - if (c->mode == MODE_PASTA) { - bind_addr = &in6addr_loopback; - uref.udp.splice = uref.udp.orig = true; - - s = sock_l4(c, AF_INET6, IPPROTO_UDP, bind_addr, - ifname, port, uref.u32); - udp_splice_init[V6][port].sock = s; - } + udp_splice_init[V6][port].sock = s; } else { - bind_addr = &in6addr_loopback; - uref.udp.splice = uref.udp.orig = uref.udp.ns = true; + uref.udp.ns = true; - s = sock_l4(c, AF_INET6, IPPROTO_UDP, bind_addr, + s = sock_l4(c, AF_INET6, IPPROTO_UDP, &in6addr_loopback, ifname, port, uref.u32); udp_splice_ns[V6][port].sock = s; }