diff options
Diffstat (limited to 'udp.c')
| -rw-r--r-- | udp.c | 1442 |
1 files changed, 593 insertions, 849 deletions
@@ -15,79 +15,64 @@ /** * DOC: Theory of Operation * + * UDP Flows + * ========= * - * For UDP, a reduced version of port-based connection tracking is implemented - * with two purposes: - * - binding ephemeral ports when they're used as source port by the guest, so - * that replies on those ports can be forwarded back to the guest, with a - * fixed timeout for this binding - * - packets received from the local host get their source changed to a local - * address (gateway address) so that they can be forwarded to the guest, and - * packets sent as replies by the guest need their destination address to - * be changed back to the address of the local host. This is dynamic to allow - * connections from the gateway as well, and uses the same fixed 180s timeout - * - * Sockets for bound ports are created at initialisation time, one set for IPv4 - * and one for IPv6. + * UDP doesn't have true connections, but many protocols use a connection-like + * format. The flow is initiated by a client sending a datagram from a port of + * its choosing (usually ephemeral) to a specific port (usually well known) on a + * server. Both client and server address must be unicast. The server sends + * replies using the same addresses & ports with src/dest swapped. * - * Packets are forwarded back and forth, by prepending and stripping UDP headers - * in the obvious way, with no port translation. + * We track pseudo-connections of this type as flow table entries of type + * FLOW_UDP. We store the time of the last traffic on the flow in uflow->ts, + * and let the flow expire if there is no traffic for UDP_CONN_TIMEOUT seconds. * - * In PASTA mode, the L2-L4 translation is skipped for connections to ports - * bound between namespaces using the loopback interface, messages are directly - * transferred between L4 sockets instead. These are called spliced connections - * for consistency with the TCP implementation, but the splice() syscall isn't - * actually used as it wouldn't make sense for datagram-based connections: a - * pair of recvmmsg() and sendmmsg() deals with this case. + * NOTE: This won't handle multicast protocols, or some protocols with different + * port usage. We'll need specific logic if we want to handle those. + * + * "Listening" sockets + * =================== * - * The connection tracking for PASTA mode is slightly complicated by the absence - * of actual connections, see struct udp_splice_port, and these examples: + * UDP doesn't use listen(), but we consider long term sockets which are allowed + * to create new flows "listening" by analogy with TCP. This listening socket + * could receive packets from multiple flows, so we use a hash table match to + * find the specific flow for a datagram. * - * - from init to namespace: + * When a UDP flow is initiated from a listening socket we take a duplicate of + * the socket and store it in uflow->s[INISIDE]. This will last for the + * lifetime of the flow, even if the original listening socket is closed due to + * port auto-probing. The duplicate is used to deliver replies back to the + * originating side. * - * - forward direction: 127.0.0.1:5000 -> 127.0.0.1:80 in init from socket s, - * with epoll reference: index = 80, splice = 1, orig = 1, ns = 0 - * - if udp_splice_ns[V4][5000].sock: - * - send packet to udp_splice_ns[V4][5000].sock, with destination port - * 80 - * - otherwise: - * - create new socket udp_splice_ns[V4][5000].sock - * - bind in namespace to 127.0.0.1:5000 - * - add to epoll with reference: index = 5000, splice = 1, orig = 0, - * ns = 1 - * - update udp_splice_init[V4][80].ts and udp_splice_ns[V4][5000].ts with - * current time + * Reply sockets + * ============= * - * - reverse direction: 127.0.0.1:80 -> 127.0.0.1:5000 in namespace socket s, - * having epoll reference: index = 5000, splice = 1, orig = 0, ns = 1 - * - if udp_splice_init[V4][80].sock: - * - send to udp_splice_init[V4][80].sock, with destination port 5000 - * - update udp_splice_init[V4][80].ts and udp_splice_ns[V4][5000].ts with - * current time - * - otherwise, discard + * When a UDP flow targets a socket, we create a "reply" socket in + * uflow->s[TGTSIDE] both to deliver datagrams to the target side and receive + * replies on the target side. This socket is both bound and connected and has + * EPOLL_TYPE_UDP_REPLY. The connect() means it will only receive datagrams + * associated with this flow, so the epoll reference directly points to the flow + * and we don't need a hash lookup. * - * - from namespace to init: + * NOTE: it's possible that the reply socket could have a bound address + * overlapping with an unrelated listening socket. We assume datagrams for the + * flow will come to the reply socket in preference to a listening socket. The + * sample program doc/platform-requirements/reuseaddr-priority.c documents and + * tests that assumption. * - * - forward direction: 127.0.0.1:2000 -> 127.0.0.1:22 in namespace from - * socket s, with epoll reference: index = 22, splice = 1, orig = 1, ns = 1 - * - if udp4_splice_init[V4][2000].sock: - * - send packet to udp_splice_init[V4][2000].sock, with destination - * port 22 - * - otherwise: - * - create new socket udp_splice_init[V4][2000].sock - * - bind in init to 127.0.0.1:2000 - * - add to epoll with reference: index = 2000, splice = 1, orig = 0, - * ns = 0 - * - update udp_splice_ns[V4][22].ts and udp_splice_init[V4][2000].ts with - * current time + * "Spliced" flows + * =============== + * + * In PASTA mode, L2-L4 translation is skipped for connections to ports bound + * between namespaces using the loopback interface, messages are directly + * transferred between L4 sockets instead. These are called spliced connections + * in analogy with the TCP implementation. The the splice() syscall isn't + * actually used; it doesn't make sense for datagrams and instead a pair of + * recvmmsg() and sendmmsg() is used to forward the datagrams. * - * - reverse direction: 127.0.0.1:22 -> 127.0.0.1:2000 in init from socket s, - * having epoll reference: index = 2000, splice = 1, orig = 0, ns = 0 - * - if udp_splice_ns[V4][22].sock: - * - send to udp_splice_ns[V4][22].sock, with destination port 2000 - * - update udp_splice_ns[V4][22].ts and udp_splice_init[V4][2000].ts with - * current time - * - otherwise, discard + * Note that a spliced flow will have *both* a duplicated listening socket and a + * reply socket (see above). */ #include <sched.h> @@ -110,9 +95,12 @@ #include <sys/socket.h> #include <sys/uio.h> #include <time.h> +#include <arpa/inet.h> +#include <linux/errqueue.h> #include "checksum.h" #include "util.h" +#include "iov.h" #include "ip.h" #include "siphash.h" #include "inany.h" @@ -120,125 +108,74 @@ #include "tap.h" #include "pcap.h" #include "log.h" +#include "flow_table.h" #include "udp_internal.h" +#include "udp_vu.h" -/** - * struct udp_tap_port - Port tracking based on tap-facing source port - * @sock: Socket bound to source port used as index - * @flags: Flags for local bind, loopback address/unicast address as source - * @ts: Activity timestamp from tap, used for socket aging - */ -struct udp_tap_port { - int sock; - uint8_t flags; -#define PORT_LOCAL BIT(0) -#define PORT_LOOPBACK BIT(1) -#define PORT_GUA BIT(2) - - time_t ts; -}; - -/** - * struct udp_splice_port - Bound socket for spliced communication - * @sock: Socket bound to index port - * @ts: Activity timestamp - */ -struct udp_splice_port { - int sock; - time_t ts; -}; +/* "Spliced" sockets indexed by bound port (host order) */ +static int udp_splice_ns [IP_VERSIONS][NUM_PORTS]; +static int udp_splice_init[IP_VERSIONS][NUM_PORTS]; -/* Port tracking, arrays indexed by packet source port (host order) */ -static struct udp_tap_port udp_tap_map [IP_VERSIONS][NUM_PORTS]; +/* Static buffers */ -/* "Spliced" sockets indexed by bound port (host order) */ -static struct udp_splice_port udp_splice_ns [IP_VERSIONS][NUM_PORTS]; -static struct udp_splice_port udp_splice_init[IP_VERSIONS][NUM_PORTS]; - -enum udp_act_type { - UDP_ACT_TAP, - UDP_ACT_SPLICE_NS, - UDP_ACT_SPLICE_INIT, - UDP_ACT_TYPE_MAX, -}; +/* UDP header and data for inbound messages */ +static struct udp_payload_t udp_payload[UDP_MAX_FRAMES]; -/* Activity-based aging for bindings */ -static uint8_t udp_act[IP_VERSIONS][UDP_ACT_TYPE_MAX][DIV_ROUND_UP(NUM_PORTS, 8)]; +/* Ethernet header for IPv4 frames */ +static struct ethhdr udp4_eth_hdr; -/* Static buffers */ +/* Ethernet header for IPv6 frames */ +static struct ethhdr udp6_eth_hdr; /** - * udp4_l2_buf_t - Pre-cooked IPv4 packet buffers for tap connections + * struct udp_meta_t - Pre-cooked headers and metadata for UDP packets + * @ip6h: Pre-filled IPv6 header (except for payload_len and addresses) + * @ip4h: Pre-filled IPv4 header (except for tot_len and saddr) + * @taph: Tap backend specific header * @s_in: Source socket address, filled in by recvmmsg() - * @taph: Tap-level headers (partially pre-filled) - * @iph: Pre-filled IP header (except for tot_len and saddr) - * @uh: Headroom for UDP header - * @data: Storage for UDP payload + * @tosidx: sidx for the destination side of this datagram's flow */ -static struct udp4_l2_buf_t { - struct sockaddr_in s_in; - +static struct udp_meta_t { + struct ipv6hdr ip6h; + struct iphdr ip4h; struct tap_hdr taph; - struct iphdr iph; - struct udphdr uh; - uint8_t data[USHRT_MAX - - (sizeof(struct iphdr) + sizeof(struct udphdr))]; -} __attribute__ ((packed, aligned(__alignof__(unsigned int)))) -udp4_l2_buf[UDP_MAX_FRAMES]; - -/** - * udp6_l2_buf_t - Pre-cooked IPv6 packet buffers for tap connections - * @s_in6: Source socket address, filled in by recvmmsg() - * @taph: Tap-level headers (partially pre-filled) - * @ip6h: Pre-filled IP header (except for payload_len and addresses) - * @uh: Headroom for UDP header - * @data: Storage for UDP payload - */ -struct udp6_l2_buf_t { - struct sockaddr_in6 s_in6; -#ifdef __AVX2__ - /* Align ip6h to 32-byte boundary. */ - uint8_t pad[64 - (sizeof(struct sockaddr_in6) + sizeof(struct ethhdr) + - sizeof(uint32_t))]; -#endif - struct tap_hdr taph; - struct ipv6hdr ip6h; - struct udphdr uh; - uint8_t data[USHRT_MAX - - (sizeof(struct ipv6hdr) + sizeof(struct udphdr))]; + union sockaddr_inany s_in; + flow_sidx_t tosidx; +} #ifdef __AVX2__ -} __attribute__ ((packed, aligned(32))) -#else -} __attribute__ ((packed, aligned(__alignof__(unsigned int)))) +__attribute__ ((aligned(32))) #endif -udp6_l2_buf[UDP_MAX_FRAMES]; - -/* recvmmsg()/sendmmsg() data for tap */ -static struct iovec udp4_l2_iov_sock [UDP_MAX_FRAMES]; -static struct iovec udp6_l2_iov_sock [UDP_MAX_FRAMES]; +udp_meta[UDP_MAX_FRAMES]; -static struct iovec udp4_l2_iov_tap [UDP_MAX_FRAMES]; -static struct iovec udp6_l2_iov_tap [UDP_MAX_FRAMES]; +/** + * enum udp_iov_idx - Indices for the buffers making up a single UDP frame + * @UDP_IOV_TAP tap specific header + * @UDP_IOV_ETH Ethernet header + * @UDP_IOV_IP IP (v4/v6) header + * @UDP_IOV_PAYLOAD IP payload (UDP header + data) + * @UDP_NUM_IOVS the number of entries in the iovec array + */ +enum udp_iov_idx { + UDP_IOV_TAP, + UDP_IOV_ETH, + UDP_IOV_IP, + UDP_IOV_PAYLOAD, + UDP_NUM_IOVS, +}; -static struct mmsghdr udp4_l2_mh_sock [UDP_MAX_FRAMES]; -static struct mmsghdr udp6_l2_mh_sock [UDP_MAX_FRAMES]; +/* IOVs and msghdr arrays for receiving datagrams from sockets */ +static struct iovec udp_iov_recv [UDP_MAX_FRAMES]; +static struct mmsghdr udp_mh_recv [UDP_MAX_FRAMES]; -/* recvmmsg()/sendmmsg() data for "spliced" connections */ -static struct iovec udp4_iov_splice [UDP_MAX_FRAMES]; -static struct iovec udp6_iov_splice [UDP_MAX_FRAMES]; +/* IOVs and msghdr arrays for sending "spliced" datagrams to sockets */ +static union sockaddr_inany udp_splice_to; -struct sockaddr_in udp4_localname = { - .sin_family = AF_INET, - .sin_addr = IN4ADDR_LOOPBACK_INIT, -}; -struct sockaddr_in6 udp6_localname = { - .sin6_family = AF_INET6, - .sin6_addr = IN6ADDR_LOOPBACK_INIT, -}; +static struct iovec udp_iov_splice [UDP_MAX_FRAMES]; +static struct mmsghdr udp_mh_splice [UDP_MAX_FRAMES]; -static struct mmsghdr udp4_mh_splice [UDP_MAX_FRAMES]; -static struct mmsghdr udp6_mh_splice [UDP_MAX_FRAMES]; +/* IOVs for L2 frames */ +static struct iovec udp_l2_iov [UDP_MAX_FRAMES][UDP_NUM_IOVS]; /** * udp_portmap_clear() - Clear UDP port map before configuration @@ -248,28 +185,8 @@ void udp_portmap_clear(void) unsigned i; for (i = 0; i < NUM_PORTS; i++) { - udp_tap_map[V4][i].sock = udp_tap_map[V6][i].sock = -1; - udp_splice_ns[V4][i].sock = udp_splice_ns[V6][i].sock = -1; - udp_splice_init[V4][i].sock = udp_splice_init[V6][i].sock = -1; - } -} - -/** - * udp_invert_portmap() - Compute reverse port translations for return packets - * @fwd: Port forwarding configuration to compute reverse map for - */ -static void udp_invert_portmap(struct udp_fwd_ports *fwd) -{ - unsigned int i; - - static_assert(ARRAY_SIZE(fwd->f.delta) == ARRAY_SIZE(fwd->rdelta), - "Forward and reverse delta arrays must have same size"); - for (i = 0; i < ARRAY_SIZE(fwd->f.delta); i++) { - in_port_t delta = fwd->f.delta[i]; - in_port_t rport = i + delta; - - if (delta) - fwd->rdelta[rport] = NUM_PORTS - delta; + udp_splice_ns[V4][i] = udp_splice_ns[V6][i] = -1; + udp_splice_init[V4][i] = udp_splice_init[V6][i] = -1; } } @@ -280,473 +197,448 @@ static void udp_invert_portmap(struct udp_fwd_ports *fwd) */ void udp_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s) { - int i; - - for (i = 0; i < UDP_MAX_FRAMES; i++) { - struct udp4_l2_buf_t *b4 = &udp4_l2_buf[i]; - struct udp6_l2_buf_t *b6 = &udp6_l2_buf[i]; - - eth_update_mac(&b4->taph.eh, eth_d, eth_s); - eth_update_mac(&b6->taph.eh, eth_d, eth_s); - } + eth_update_mac(&udp4_eth_hdr, eth_d, eth_s); + eth_update_mac(&udp6_eth_hdr, eth_d, eth_s); } /** - * udp_sock4_iov_init() - Initialise scatter-gather L2 buffers for IPv4 sockets + * udp_iov_init_one() - Initialise scatter-gather lists for one buffer * @c: Execution context + * @i: Index of buffer to initialize */ -static void udp_sock4_iov_init(const struct ctx *c) +static void udp_iov_init_one(const struct ctx *c, size_t i) { - struct mmsghdr *h; - int i; - - for (i = 0; i < ARRAY_SIZE(udp4_l2_buf); i++) { - udp4_l2_buf[i] = (struct udp4_l2_buf_t) { - .taph = TAP_HDR_INIT(ETH_P_IP), - .iph = L2_BUF_IP4_INIT(IPPROTO_UDP) - }; - } - - for (i = 0, h = udp4_l2_mh_sock; i < UDP_MAX_FRAMES; i++, h++) { - struct msghdr *mh = &h->msg_hdr; - - mh->msg_name = &udp4_l2_buf[i].s_in; - mh->msg_namelen = sizeof(udp4_l2_buf[i].s_in); - - udp4_l2_iov_sock[i].iov_base = udp4_l2_buf[i].data; - udp4_l2_iov_sock[i].iov_len = sizeof(udp4_l2_buf[i].data); - mh->msg_iov = &udp4_l2_iov_sock[i]; - mh->msg_iovlen = 1; - } - - for (i = 0; i < UDP_MAX_FRAMES; i++) { - struct iovec *iov = &udp4_l2_iov_tap[i]; - - iov->iov_base = tap_iov_base(c, &udp4_l2_buf[i].taph); - } + struct udp_payload_t *payload = &udp_payload[i]; + struct msghdr *mh = &udp_mh_recv[i].msg_hdr; + struct udp_meta_t *meta = &udp_meta[i]; + struct iovec *siov = &udp_iov_recv[i]; + struct iovec *tiov = udp_l2_iov[i]; + + *meta = (struct udp_meta_t) { + .ip4h = L2_BUF_IP4_INIT(IPPROTO_UDP), + .ip6h = L2_BUF_IP6_INIT(IPPROTO_UDP), + }; + + *siov = IOV_OF_LVALUE(payload->data); + + tiov[UDP_IOV_TAP] = tap_hdr_iov(c, &meta->taph); + tiov[UDP_IOV_PAYLOAD].iov_base = payload; + + mh->msg_name = &meta->s_in; + mh->msg_namelen = sizeof(meta->s_in); + mh->msg_iov = siov; + mh->msg_iovlen = 1; } /** - * udp_sock6_iov_init() - Initialise scatter-gather L2 buffers for IPv6 sockets + * udp_iov_init() - Initialise scatter-gather L2 buffers * @c: Execution context */ -static void udp_sock6_iov_init(const struct ctx *c) +static void udp_iov_init(const struct ctx *c) { - struct mmsghdr *h; - int i; + size_t i; - for (i = 0; i < ARRAY_SIZE(udp6_l2_buf); i++) { - udp6_l2_buf[i] = (struct udp6_l2_buf_t) { - .taph = TAP_HDR_INIT(ETH_P_IPV6), - .ip6h = L2_BUF_IP6_INIT(IPPROTO_UDP) - }; - } + udp4_eth_hdr.h_proto = htons_constant(ETH_P_IP); + udp6_eth_hdr.h_proto = htons_constant(ETH_P_IPV6); - for (i = 0, h = udp6_l2_mh_sock; i < UDP_MAX_FRAMES; i++, h++) { - struct msghdr *mh = &h->msg_hdr; + for (i = 0; i < UDP_MAX_FRAMES; i++) + udp_iov_init_one(c, i); +} - mh->msg_name = &udp6_l2_buf[i].s_in6; - mh->msg_namelen = sizeof(struct sockaddr_in6); +/** + * udp_splice_prepare() - Prepare one datagram for splicing + * @mmh: Receiving mmsghdr array + * @idx: Index of the datagram to prepare + */ +static void udp_splice_prepare(struct mmsghdr *mmh, unsigned idx) +{ + udp_mh_splice[idx].msg_hdr.msg_iov->iov_len = mmh[idx].msg_len; +} - udp6_l2_iov_sock[i].iov_base = udp6_l2_buf[i].data; - udp6_l2_iov_sock[i].iov_len = sizeof(udp6_l2_buf[i].data); - mh->msg_iov = &udp6_l2_iov_sock[i]; - mh->msg_iovlen = 1; - } +/** + * udp_splice_send() - Send a batch of datagrams from socket to socket + * @c: Execution context + * @start: Index of batch's first datagram in udp[46]_l2_buf + * @n: Number of datagrams in batch + * @src: Source port for datagram (target side) + * @dst: Destination port for datagrams (target side) + * @ref: epoll reference for origin socket + * @now: Timestamp + */ +static void udp_splice_send(const struct ctx *c, size_t start, size_t n, + flow_sidx_t tosidx) +{ + const struct flowside *toside = flowside_at_sidx(tosidx); + const struct udp_flow *uflow = udp_at_sidx(tosidx); + uint8_t topif = pif_at_sidx(tosidx); + int s = uflow->s[tosidx.sidei]; + socklen_t sl; - for (i = 0; i < UDP_MAX_FRAMES; i++) { - struct iovec *iov = &udp6_l2_iov_tap[i]; + pif_sockaddr(c, &udp_splice_to, &sl, topif, + &toside->eaddr, toside->eport); - iov->iov_base = tap_iov_base(c, &udp6_l2_buf[i].taph); - } + sendmmsg(s, udp_mh_splice + start, n, MSG_NOSIGNAL); } /** - * udp_splice_new() - Create and prepare socket for "spliced" binding - * @c: Execution context - * @v6: Set for IPv6 sockets - * @src: Source port of original connection, host order - * @ns: Does the splice originate in the ns or not - * - * Return: prepared socket, negative error code on failure + * udp_update_hdr4() - Update headers for one IPv4 datagram + * @ip4h: Pre-filled IPv4 header (except for tot_len and saddr) + * @bp: Pointer to udp_payload_t to update + * @toside: Flowside for destination side + * @dlen: Length of UDP payload + * @no_udp_csum: Do not set UDP checksum * - * #syscalls:pasta getsockname + * Return: size of IPv4 payload (UDP header + data) */ -int udp_splice_new(const struct ctx *c, int v6, in_port_t src, bool ns) +size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp, + const struct flowside *toside, size_t dlen, + bool no_udp_csum) { - struct epoll_event ev = { .events = EPOLLIN | EPOLLRDHUP | EPOLLHUP }; - union epoll_ref ref = { .type = EPOLL_TYPE_UDP, - .udp = { .splice = true, .v6 = v6, .port = src } - }; - struct udp_splice_port *sp; - int act, s; - - if (ns) { - ref.udp.pif = PIF_SPLICE; - sp = &udp_splice_ns[v6 ? V6 : V4][src]; - act = UDP_ACT_SPLICE_NS; + const struct in_addr *src = inany_v4(&toside->oaddr); + const struct in_addr *dst = inany_v4(&toside->eaddr); + size_t l4len = dlen + sizeof(bp->uh); + size_t l3len = l4len + sizeof(*ip4h); + + ASSERT(src && dst); + + ip4h->tot_len = htons(l3len); + ip4h->daddr = dst->s_addr; + ip4h->saddr = src->s_addr; + ip4h->check = csum_ip4_header(l3len, IPPROTO_UDP, *src, *dst); + + bp->uh.source = htons(toside->oport); + bp->uh.dest = htons(toside->eport); + bp->uh.len = htons(l4len); + if (no_udp_csum) { + bp->uh.check = 0; } else { - ref.udp.pif = PIF_HOST; - sp = &udp_splice_init[v6 ? V6 : V4][src]; - act = UDP_ACT_SPLICE_INIT; + const struct iovec iov = { + .iov_base = bp->data, + .iov_len = dlen + }; + csum_udp4(&bp->uh, *src, *dst, &iov, 1, 0); } - s = socket(v6 ? AF_INET6 : AF_INET, SOCK_DGRAM | SOCK_NONBLOCK, - IPPROTO_UDP); - - if (s > FD_REF_MAX) { - close(s); - return -EIO; - } + return l4len; +} - if (s < 0) - return s; +/** + * udp_update_hdr6() - Update headers for one IPv6 datagram + * @ip6h: Pre-filled IPv6 header (except for payload_len and + * addresses) + * @bp: Pointer to udp_payload_t to update + * @toside: Flowside for destination side + * @dlen: Length of UDP payload + * @no_udp_csum: Do not set UDP checksum + * + * Return: size of IPv6 payload (UDP header + data) + */ +size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp, + const struct flowside *toside, size_t dlen, + bool no_udp_csum) +{ + uint16_t l4len = dlen + sizeof(bp->uh); - ref.fd = s; + ip6h->payload_len = htons(l4len); + ip6h->daddr = toside->eaddr.a6; + ip6h->saddr = toside->oaddr.a6; + ip6h->version = 6; + ip6h->nexthdr = IPPROTO_UDP; + ip6h->hop_limit = 255; - if (v6) { - struct sockaddr_in6 addr6 = { - .sin6_family = AF_INET6, - .sin6_port = htons(src), - .sin6_addr = IN6ADDR_LOOPBACK_INIT, - }; - if (bind(s, (struct sockaddr *)&addr6, sizeof(addr6))) - goto fail; + bp->uh.source = htons(toside->oport); + bp->uh.dest = htons(toside->eport); + bp->uh.len = ip6h->payload_len; + if (no_udp_csum) { + /* 0 is an invalid checksum for UDP IPv6 and dropped by + * the kernel stack, even if the checksum is disabled by virtio + * flags. We need to put any non-zero value here. + */ + bp->uh.check = 0xffff; } else { - struct sockaddr_in addr4 = { - .sin_family = AF_INET, - .sin_port = htons(src), - .sin_addr = IN4ADDR_LOOPBACK_INIT, + const struct iovec iov = { + .iov_base = bp->data, + .iov_len = dlen }; - if (bind(s, (struct sockaddr *)&addr4, sizeof(addr4))) - goto fail; + csum_udp6(&bp->uh, &toside->oaddr.a6, &toside->eaddr.a6, + &iov, 1, 0); } - sp->sock = s; - bitmap_set(udp_act[v6 ? V6 : V4][act], src); - - ev.data.u64 = ref.u64; - epoll_ctl(c->epollfd, EPOLL_CTL_ADD, s, &ev); - return s; - -fail: - close(s); - return -1; + return l4len; } /** - * struct udp_splice_new_ns_arg - Arguments for udp_splice_new_ns() - * @c: Execution context - * @v6: Set for IPv6 - * @src: Source port of originating datagram, host order - * @dst: Destination port of originating datagram, host order - * @s: Newly created socket or negative error code + * udp_tap_prepare() - Convert one datagram into a tap frame + * @mmh: Receiving mmsghdr array + * @idx: Index of the datagram to prepare + * @toside: Flowside for destination side + * @no_udp_csum: Do not set UDP checksum */ -struct udp_splice_new_ns_arg { - const struct ctx *c; - int v6; - in_port_t src; - int s; -}; +static void udp_tap_prepare(const struct mmsghdr *mmh, + unsigned idx, const struct flowside *toside, + bool no_udp_csum) +{ + struct iovec (*tap_iov)[UDP_NUM_IOVS] = &udp_l2_iov[idx]; + struct udp_payload_t *bp = &udp_payload[idx]; + struct udp_meta_t *bm = &udp_meta[idx]; + size_t l4len; + + if (!inany_v4(&toside->eaddr) || !inany_v4(&toside->oaddr)) { + l4len = udp_update_hdr6(&bm->ip6h, bp, toside, + mmh[idx].msg_len, no_udp_csum); + tap_hdr_update(&bm->taph, l4len + sizeof(bm->ip6h) + + sizeof(udp6_eth_hdr)); + (*tap_iov)[UDP_IOV_ETH] = IOV_OF_LVALUE(udp6_eth_hdr); + (*tap_iov)[UDP_IOV_IP] = IOV_OF_LVALUE(bm->ip6h); + } else { + l4len = udp_update_hdr4(&bm->ip4h, bp, toside, + mmh[idx].msg_len, no_udp_csum); + tap_hdr_update(&bm->taph, l4len + sizeof(bm->ip4h) + + sizeof(udp4_eth_hdr)); + (*tap_iov)[UDP_IOV_ETH] = IOV_OF_LVALUE(udp4_eth_hdr); + (*tap_iov)[UDP_IOV_IP] = IOV_OF_LVALUE(bm->ip4h); + } + (*tap_iov)[UDP_IOV_PAYLOAD].iov_len = l4len; +} /** - * udp_splice_new_ns() - Enter namespace and call udp_splice_new() - * @arg: See struct udp_splice_new_ns_arg + * udp_sock_recverr() - Receive and clear an error from a socket + * @s: Socket to receive from * - * Return: 0 + * Return: 1 if error received and processed, 0 if no more errors in queue, < 0 + * if there was an error reading the queue + * + * #syscalls recvmsg */ -static int udp_splice_new_ns(void *arg) +static int udp_sock_recverr(int s) { - struct udp_splice_new_ns_arg *a; + const struct sock_extended_err *ee; + const struct cmsghdr *hdr; + char buf[CMSG_SPACE(sizeof(*ee))]; + struct msghdr mh = { + .msg_name = NULL, + .msg_namelen = 0, + .msg_iov = NULL, + .msg_iovlen = 0, + .msg_control = buf, + .msg_controllen = sizeof(buf), + }; + ssize_t rc; + + rc = recvmsg(s, &mh, MSG_ERRQUEUE); + if (rc < 0) { + if (errno == EAGAIN || errno == EWOULDBLOCK) + return 0; + + err_perror("UDP: Failed to read error queue"); + return -1; + } - a = (struct udp_splice_new_ns_arg *)arg; + if (!(mh.msg_flags & MSG_ERRQUEUE)) { + err("Missing MSG_ERRQUEUE flag reading error queue"); + return -1; + } - ns_enter(a->c); + hdr = CMSG_FIRSTHDR(&mh); + if (!((hdr->cmsg_level == IPPROTO_IP && + hdr->cmsg_type == IP_RECVERR) || + (hdr->cmsg_level == IPPROTO_IPV6 && + hdr->cmsg_type == IPV6_RECVERR))) { + err("Unexpected cmsg reading error queue"); + return -1; + } - a->s = udp_splice_new(a->c, a->v6, a->src, true); + ee = (const struct sock_extended_err *)CMSG_DATA(hdr); - return 0; + /* TODO: When possible propagate and otherwise handle errors */ + debug("%s error on UDP socket %i: %s", + str_ee_origin(ee), s, strerror(ee->ee_errno)); + + return 1; } /** - * udp_mmh_splice_port() - Is source address of message suitable for splicing? - * @v6: Is @sa a sockaddr_in6 (otherwise sockaddr_in)? - * @mmh: mmsghdr of incoming message + * udp_sock_errs() - Process errors on a socket + * @c: Execution context + * @s: Socket to receive from + * @events: epoll events bitmap * - * Return: if @sa refers to localhost (127.0.0.1 or ::1) the port from - * @sa in host order, otherwise -1. + * Return: Number of errors handled, or < 0 if we have an unrecoverable error */ -static int udp_mmh_splice_port(bool v6, const struct mmsghdr *mmh) +int udp_sock_errs(const struct ctx *c, int s, uint32_t events) { - const struct sockaddr_in6 *sa6 = mmh->msg_hdr.msg_name; - const struct sockaddr_in *sa4 = mmh->msg_hdr.msg_name; + unsigned n_err = 0; + socklen_t errlen; + int rc, err; - if (v6 && IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) - return ntohs(sa6->sin6_port); + ASSERT(!c->no_udp); - if (!v6 && IN4_IS_ADDR_LOOPBACK(&sa4->sin_addr)) - return ntohs(sa4->sin_port); + if (!(events & EPOLLERR)) + return 0; /* Nothing to do */ - return -1; -} + /* Empty the error queue */ + while ((rc = udp_sock_recverr(s)) > 0) + n_err += rc; -/** - * udp_splice_sendfrom() - Send datagrams from given port to given port - * @c: Execution context - * @start: Index of first datagram in udp[46]_l2_buf - * @n: Number of datagrams to send - * @src: Datagrams will be sent from this port (on origin side) - * @dst: Datagrams will be send to this port (on destination side) - * @from_pif: pif from which the packet originated - * @v6: Send as IPv6? - * @allow_new: If true create sending socket if needed, if false discard - * if no sending socket is available - * @now: Timestamp - */ -static void udp_splice_sendfrom(const struct ctx *c, unsigned start, unsigned n, - in_port_t src, in_port_t dst, uint8_t from_pif, - bool v6, bool allow_new, - const struct timespec *now) -{ - struct mmsghdr *mmh_recv, *mmh_send; - unsigned int i; - int s; + if (rc < 0) + return -1; /* error reading error, unrecoverable */ - if (v6) { - mmh_recv = udp6_l2_mh_sock; - mmh_send = udp6_mh_splice; - } else { - mmh_recv = udp4_l2_mh_sock; - mmh_send = udp4_mh_splice; + errlen = sizeof(err); + if (getsockopt(s, SOL_SOCKET, SO_ERROR, &err, &errlen) < 0 || + errlen != sizeof(err)) { + err_perror("Error reading SO_ERROR"); + return -1; /* error reading error, unrecoverable */ } - if (from_pif == PIF_SPLICE) { - src += c->udp.fwd_in.rdelta[src]; - s = udp_splice_init[v6][src].sock; - if (s < 0 && allow_new) - s = udp_splice_new(c, v6, src, false); - - if (s < 0) - return; - - udp_splice_ns[v6][dst].ts = now->tv_sec; - udp_splice_init[v6][src].ts = now->tv_sec; - } else { - ASSERT(from_pif == PIF_HOST); - src += c->udp.fwd_out.rdelta[src]; - s = udp_splice_ns[v6][src].sock; - if (s < 0 && allow_new) { - struct udp_splice_new_ns_arg arg = { - c, v6, src, -1, - }; - - NS_CALL(udp_splice_new_ns, &arg); - s = arg.s; - } - if (s < 0) - return; - - udp_splice_init[v6][dst].ts = now->tv_sec; - udp_splice_ns[v6][src].ts = now->tv_sec; + if (err) { + debug("Unqueued error on UDP socket %i: %s", s, strerror(err)); + n_err++; } - for (i = start; i < start + n; i++) - mmh_send[i].msg_hdr.msg_iov->iov_len = mmh_recv[i].msg_len; + if (!n_err) { + /* EPOLLERR, but no errors to clear !? */ + err("EPOLLERR event without reported errors on socket %i", s); + return -1; /* no way to clear, unrecoverable */ + } - sendmmsg(s, mmh_send + start, n, MSG_NOSIGNAL); + return n_err; } /** - * udp_update_hdr4() - Update headers for one IPv4 datagram + * udp_sock_recv() - Receive datagrams from a socket * @c: Execution context - * @n: Index of buffer in udp4_l2_buf pool - * @dstport: Destination port number - * @now: Current timestamp + * @s: Socket to receive from + * @events: epoll events bitmap + * @mmh mmsghdr array to receive into * - * Return: size of tap frame with headers + * Return: Number of datagrams received + * + * #syscalls recvmmsg arm:recvmmsg_time64 i686:recvmmsg_time64 */ -size_t udp_update_hdr4(const struct ctx *c, struct iphdr *iph, - size_t data_len, struct sockaddr_in *s_in, - in_port_t dstport, const struct timespec *now) +static int udp_sock_recv(const struct ctx *c, int s, uint32_t events, + struct mmsghdr *mmh) { - struct udphdr *uh = (struct udphdr *)(iph + 1); - const struct in_addr *src; - in_port_t src_port; - size_t ip_len; - - ip_len = data_len + sizeof(struct iphdr) + sizeof(struct udphdr); - - iph->tot_len = htons(ip_len); - iph->daddr = c->ip4.addr_seen.s_addr; - - src = &s_in->sin_addr; - src_port = ntohs(s_in->sin_port); - - if (!IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns_match) && - IN4_ARE_ADDR_EQUAL(src, &c->ip4.dns_host) && src_port == 53) { - src = &c->ip4.dns_match; - } else if (IN4_IS_ADDR_LOOPBACK(src) || - IN4_ARE_ADDR_EQUAL(src, &c->ip4.addr_seen)) { - udp_tap_map[V4][src_port].ts = now->tv_sec; - udp_tap_map[V4][src_port].flags |= PORT_LOCAL; + /* For not entirely clear reasons (data locality?) pasta gets better + * throughput if we receive tap datagrams one at a atime. For small + * splice datagrams throughput is slightly better if we do batch, but + * it's slightly worse for large splice datagrams. Since we don't know + * before we receive whether we'll use tap or splice, always go one at a + * time for pasta mode. + */ + int n = (c->mode == MODE_PASTA ? 1 : UDP_MAX_FRAMES); - if (IN4_IS_ADDR_LOOPBACK(src)) - udp_tap_map[V4][src_port].flags |= PORT_LOOPBACK; - else - udp_tap_map[V4][src_port].flags &= ~PORT_LOOPBACK; + ASSERT(!c->no_udp); - bitmap_set(udp_act[V4][UDP_ACT_TAP], src_port); + if (!(events & EPOLLIN)) + return 0; - src = &c->ip4.gw; + n = recvmmsg(s, mmh, n, 0, NULL); + if (n < 0) { + err_perror("Error receiving datagrams"); + return 0; } - iph->saddr = src->s_addr; - - iph->check = csum_ip4_header(iph->tot_len, IPPROTO_UDP, - *src, c->ip4.addr_seen); - uh->source = s_in->sin_port; - uh->dest = htons(dstport); - uh->len = htons(data_len + sizeof(struct udphdr)); - uh->check = 0; - return ip_len; + return n; } /** - * udp_update_hdr6() - Update headers for one IPv6 datagram + * udp_buf_listen_sock_handler() - Handle new data from socket * @c: Execution context - * @n: Index of buffer in udp6_l2_buf pool - * @dstport: Destination port number + * @ref: epoll reference + * @events: epoll events bitmap * @now: Current timestamp * - * Return: size of tap frame with headers + * #syscalls recvmmsg */ -size_t udp_update_hdr6(const struct ctx *c, struct ipv6hdr *ip6h, - size_t data_len, struct sockaddr_in6 *s_in6, - in_port_t dstport, const struct timespec *now) +static void udp_buf_listen_sock_handler(const struct ctx *c, + union epoll_ref ref, uint32_t events, + const struct timespec *now) { - struct udphdr *uh = (struct udphdr *)(ip6h + 1); - const struct in6_addr *src, *dst; - uint16_t payload_len; - in_port_t src_port; - size_t ip_len; - - dst = &c->ip6.addr_seen; - src = &s_in6->sin6_addr; - src_port = ntohs(s_in6->sin6_port); - - ip_len = data_len + sizeof(struct ipv6hdr) + sizeof(struct udphdr); - - payload_len = data_len + sizeof(struct udphdr); - ip6h->payload_len = htons(payload_len); - - if (IN6_IS_ADDR_LINKLOCAL(src)) { - dst = &c->ip6.addr_ll_seen; - } else if (!IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns_match) && - IN6_ARE_ADDR_EQUAL(src, &c->ip6.dns_host) && - src_port == 53) { - src = &c->ip6.dns_match; - } else if (IN6_IS_ADDR_LOOPBACK(src) || - IN6_ARE_ADDR_EQUAL(src, &c->ip6.addr_seen) || - IN6_ARE_ADDR_EQUAL(src, &c->ip6.addr)) { - udp_tap_map[V6][src_port].ts = now->tv_sec; - udp_tap_map[V6][src_port].flags |= PORT_LOCAL; - - if (IN6_IS_ADDR_LOOPBACK(src)) - udp_tap_map[V6][src_port].flags |= PORT_LOOPBACK; - else - udp_tap_map[V6][src_port].flags &= ~PORT_LOOPBACK; - - if (IN6_ARE_ADDR_EQUAL(src, &c->ip6.addr)) - udp_tap_map[V6][src_port].flags |= PORT_GUA; - else - udp_tap_map[V6][src_port].flags &= ~PORT_GUA; - - bitmap_set(udp_act[V6][UDP_ACT_TAP], src_port); - - dst = &c->ip6.addr_ll_seen; - - if (IN6_IS_ADDR_LINKLOCAL(&c->ip6.gw)) - src = &c->ip6.gw; - else - src = &c->ip6.addr_ll; + const socklen_t sasize = sizeof(udp_meta[0].s_in); + int n, i; + + if (udp_sock_errs(c, ref.fd, events) < 0) { + err("UDP: Unrecoverable error on listening socket:" + " (%s port %hu)", pif_name(ref.udp.pif), ref.udp.port); + /* FIXME: what now? close/re-open socket? */ + return; } - ip6h->daddr = *dst; - ip6h->saddr = *src; - ip6h->version = 6; - ip6h->nexthdr = IPPROTO_UDP; - ip6h->hop_limit = 255; - uh->source = s_in6->sin6_port; - uh->dest = htons(dstport); - uh->len = ip6h->payload_len; - uh->check = 0; - if (c->mode != MODE_VU) - uh->check = csum(uh, payload_len, - proto_ipv6_header_psum(payload_len, IPPROTO_UDP, - src, dst)); - else - uh->check = 0xffff; /* zero checksum is invalid with IPv6 */ - - return ip_len; + if ((n = udp_sock_recv(c, ref.fd, events, udp_mh_recv)) <= 0) + return; + + /* We divide datagrams into batches based on how we need to send them, + * determined by udp_meta[i].tosidx. To avoid either two passes through + * the array, or recalculating tosidx for a single entry, we have to + * populate it one entry *ahead* of the loop counter. + */ + udp_meta[0].tosidx = udp_flow_from_sock(c, ref, &udp_meta[0].s_in, now); + udp_mh_recv[0].msg_hdr.msg_namelen = sasize; + for (i = 0; i < n; ) { + flow_sidx_t batchsidx = udp_meta[i].tosidx; + uint8_t batchpif = pif_at_sidx(batchsidx); + int batchstart = i; + + do { + if (pif_is_socket(batchpif)) { + udp_splice_prepare(udp_mh_recv, i); + } else if (batchpif == PIF_TAP) { + udp_tap_prepare(udp_mh_recv, i, + flowside_at_sidx(batchsidx), + false); + } + + if (++i >= n) + break; + + udp_meta[i].tosidx = udp_flow_from_sock(c, ref, + &udp_meta[i].s_in, + now); + udp_mh_recv[i].msg_hdr.msg_namelen = sasize; + } while (flow_sidx_eq(udp_meta[i].tosidx, batchsidx)); + + if (pif_is_socket(batchpif)) { + udp_splice_send(c, batchstart, i - batchstart, + batchsidx); + } else if (batchpif == PIF_TAP) { + tap_send_frames(c, &udp_l2_iov[batchstart][0], + UDP_NUM_IOVS, i - batchstart); + } else if (flow_sidx_valid(batchsidx)) { + flow_sidx_t fromsidx = flow_sidx_opposite(batchsidx); + struct udp_flow *uflow = udp_at_sidx(batchsidx); + + flow_err(uflow, + "No support for forwarding UDP from %s to %s", + pif_name(pif_at_sidx(fromsidx)), + pif_name(batchpif)); + } else { + debug("Discarding %d datagrams without flow", + i - batchstart); + } + } } /** - * udp_tap_send() - Prepare UDP datagrams and send to tap interface + * udp_listen_sock_handler() - Handle new data from socket * @c: Execution context - * @start: Index of first datagram in udp[46]_l2_buf pool - * @n: Number of datagrams to send - * @dstport: Destination port number - * @v6: True if using IPv6 + * @ref: epoll reference + * @events: epoll events bitmap * @now: Current timestamp - * - * Return: size of tap frame with headers - */ -#pragma GCC diagnostic push -/* ignore unaligned pointer value warning for &udp6_l2_buf[i].ip6h and - * &udp4_l2_buf[i].iph */ -#pragma GCC diagnostic ignored "-Waddress-of-packed-member" -static void udp_tap_send(const struct ctx *c, - unsigned int start, unsigned int n, - in_port_t dstport, bool v6, const struct timespec *now) +void udp_listen_sock_handler(const struct ctx *c, + union epoll_ref ref, uint32_t events, + const struct timespec *now) { - struct iovec *tap_iov; - unsigned int i; - - if (v6) - tap_iov = udp6_l2_iov_tap; - else - tap_iov = udp4_l2_iov_tap; - - for (i = start; i < start + n; i++) { - size_t ip_len; - - if (v6) { - ip_len = udp_update_hdr6(c, &udp6_l2_buf[i].ip6h, - udp6_l2_mh_sock[i].msg_len, - &udp6_l2_buf[i].s_in6, dstport, - now); - tap_iov[i].iov_len = tap_iov_len(c, - &udp6_l2_buf[i].taph, - ip_len); - } else { - ip_len = udp_update_hdr4(c, &udp4_l2_buf[i].iph, - udp4_l2_mh_sock[i].msg_len, - &udp4_l2_buf[i].s_in, - dstport, now); - - tap_iov[i].iov_len = tap_iov_len(c, - &udp4_l2_buf[i].taph, - ip_len); - } + if (c->mode == MODE_VU) { + udp_vu_listen_sock_handler(c, ref, events, now); + return; } - tap_send_frames(c, tap_iov + start, n); + udp_buf_listen_sock_handler(c, ref, events, now); } -#pragma GCC diagnostic pop /** - * udp_buf_sock_handler() - Handle new data from socket + * udp_buf_reply_sock_handler() - Handle new data from flow specific socket * @c: Execution context * @ref: epoll reference * @events: epoll events bitmap @@ -754,65 +646,70 @@ static void udp_tap_send(const struct ctx *c, * * #syscalls recvmmsg */ -void udp_buf_sock_handler(const struct ctx *c, union epoll_ref ref, uint32_t events, - const struct timespec *now) +static void udp_buf_reply_sock_handler(const struct ctx *c, union epoll_ref ref, + uint32_t events, + const struct timespec *now) { - /* For not entirely clear reasons (data locality?) pasta gets - * better throughput if we receive tap datagrams one at a - * atime. For small splice datagrams throughput is slightly - * better if we do batch, but it's slightly worse for large - * splice datagrams. Since we don't know before we receive - * whether we'll use tap or splice, always go one at a time - * for pasta mode. - */ - ssize_t n = (c->mode == MODE_PASTA ? 1 : UDP_MAX_FRAMES); - in_port_t dstport = ref.udp.port; - bool v6 = ref.udp.v6; - struct mmsghdr *mmh_recv; - int i, m; + flow_sidx_t tosidx = flow_sidx_opposite(ref.flowside); + const struct flowside *toside = flowside_at_sidx(tosidx); + struct udp_flow *uflow = udp_at_sidx(ref.flowside); + uint8_t topif = pif_at_sidx(tosidx); + int n, i, from_s; - if (c->no_udp || !(events & EPOLLIN)) - return; + ASSERT(!c->no_udp && uflow); - if (ref.udp.pif == PIF_SPLICE) - dstport += c->udp.fwd_out.f.delta[dstport]; - else if (ref.udp.pif == PIF_HOST) - dstport += c->udp.fwd_in.f.delta[dstport]; + from_s = uflow->s[ref.flowside.sidei]; - if (v6) { - mmh_recv = udp6_l2_mh_sock; - udp6_localname.sin6_port = htons(dstport); - } else { - mmh_recv = udp4_l2_mh_sock; - udp4_localname.sin_port = htons(dstport); + if (udp_sock_errs(c, from_s, events) < 0) { + flow_err(uflow, "Unrecoverable error on reply socket"); + flow_err_details(uflow); + udp_flow_close(c, uflow); + return; } - n = recvmmsg(ref.fd, mmh_recv, n, 0, NULL); - if (n <= 0) + if ((n = udp_sock_recv(c, from_s, events, udp_mh_recv)) <= 0) return; - for (i = 0; i < n; i += m) { - int splicefrom = -1; - m = n; + flow_trace(uflow, "Received %d datagrams on reply socket", n); + uflow->ts = now->tv_sec; - if (ref.udp.splice) { - splicefrom = udp_mmh_splice_port(v6, mmh_recv + i); + for (i = 0; i < n; i++) { + if (pif_is_socket(topif)) + udp_splice_prepare(udp_mh_recv, i); + else if (topif == PIF_TAP) + udp_tap_prepare(udp_mh_recv, i, toside, false); + /* Restore sockaddr length clobbered by recvmsg() */ + udp_mh_recv[i].msg_hdr.msg_namelen = sizeof(udp_meta[i].s_in); + } - for (m = 1; i + m < n; m++) { - int p; + if (pif_is_socket(topif)) { + udp_splice_send(c, 0, n, tosidx); + } else if (topif == PIF_TAP) { + tap_send_frames(c, &udp_l2_iov[0][0], UDP_NUM_IOVS, n); + } else { + uint8_t frompif = pif_at_sidx(ref.flowside); - p = udp_mmh_splice_port(v6, mmh_recv + i + m); - if (p != splicefrom) - break; - } - } + flow_err(uflow, "No support for forwarding UDP from %s to %s", + pif_name(frompif), pif_name(topif)); + } +} - if (splicefrom >= 0) - udp_splice_sendfrom(c, i, m, splicefrom, dstport, - ref.udp.pif, v6, ref.udp.orig, now); - else - udp_tap_send(c, i, m, dstport, v6, now); +/** + * udp_reply_sock_handler() - Handle new data from flow specific socket + * @c: Execution context + * @ref: epoll reference + * @events: epoll events bitmap + * @now: Current timestamp + */ +void udp_reply_sock_handler(const struct ctx *c, union epoll_ref ref, + uint32_t events, const struct timespec *now) +{ + if (c->mode == MODE_VU) { + udp_vu_reply_sock_handler(c, ref, events, now); + return; } + + udp_buf_reply_sock_handler(c, ref, events, now); } /** @@ -830,23 +727,23 @@ void udp_buf_sock_handler(const struct ctx *c, union epoll_ref ref, uint32_t eve * * #syscalls sendmmsg */ -int udp_tap_handler(struct ctx *c, uint8_t pif, +int udp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af, const void *saddr, const void *daddr, const struct pool *p, int idx, const struct timespec *now) { + const struct flowside *toside; struct mmsghdr mm[UIO_MAXIOV]; + union sockaddr_inany to_sa; struct iovec m[UIO_MAXIOV]; - struct sockaddr_in6 s_in6; - struct sockaddr_in s_in; const struct udphdr *uh; - struct sockaddr *sa; + struct udp_flow *uflow; int i, s, count = 0; + flow_sidx_t tosidx; in_port_t src, dst; + uint8_t topif; socklen_t sl; - (void)c; - (void)saddr; - (void)pif; + ASSERT(!c->no_udp); uh = packet_get(p, idx, 0, sizeof(*uh), NULL); if (!uh) @@ -858,107 +755,32 @@ int udp_tap_handler(struct ctx *c, uint8_t pif, src = ntohs(uh->source); dst = ntohs(uh->dest); - if (af == AF_INET) { - s_in = (struct sockaddr_in) { - .sin_family = AF_INET, - .sin_port = uh->dest, - .sin_addr = *(struct in_addr *)daddr, - }; - - sa = (struct sockaddr *)&s_in; - sl = sizeof(s_in); - - if (IN4_ARE_ADDR_EQUAL(&s_in.sin_addr, &c->ip4.dns_match) && - ntohs(s_in.sin_port) == 53) { - s_in.sin_addr = c->ip4.dns_host; - } else if (IN4_ARE_ADDR_EQUAL(&s_in.sin_addr, &c->ip4.gw) && - !c->no_map_gw) { - if (!(udp_tap_map[V4][dst].flags & PORT_LOCAL) || - (udp_tap_map[V4][dst].flags & PORT_LOOPBACK)) - s_in.sin_addr.s_addr = htonl(INADDR_LOOPBACK); - else - s_in.sin_addr = c->ip4.addr_seen; - } - - debug("UDP from tap src=%hu dst=%hu, s=%d", - src, dst, udp_tap_map[V4][src].sock); - if ((s = udp_tap_map[V4][src].sock) < 0) { - struct in_addr bind_addr = IN4ADDR_ANY_INIT; - union udp_epoll_ref uref = { - .port = src, - .pif = PIF_HOST, - }; - const char *bind_if = NULL; - - if (!IN4_IS_ADDR_LOOPBACK(&s_in.sin_addr)) - bind_if = c->ip4.ifname_out; - - if (!IN4_IS_ADDR_LOOPBACK(&s_in.sin_addr)) - bind_addr = c->ip4.addr_out; - - s = sock_l4(c, AF_INET, IPPROTO_UDP, &bind_addr, - bind_if, src, uref.u32); - if (s < 0) - return p->count - idx; - - udp_tap_map[V4][src].sock = s; - bitmap_set(udp_act[V4][UDP_ACT_TAP], src); - } - - udp_tap_map[V4][src].ts = now->tv_sec; - } else { - s_in6 = (struct sockaddr_in6) { - .sin6_family = AF_INET6, - .sin6_port = uh->dest, - .sin6_addr = *(struct in6_addr *)daddr, - }; - const struct in6_addr *bind_addr = &in6addr_any; - - sa = (struct sockaddr *)&s_in6; - sl = sizeof(s_in6); - - if (IN6_ARE_ADDR_EQUAL(daddr, &c->ip6.dns_match) && - ntohs(s_in6.sin6_port) == 53) { - s_in6.sin6_addr = c->ip6.dns_host; - } else if (IN6_ARE_ADDR_EQUAL(daddr, &c->ip6.gw) && - !c->no_map_gw) { - if (!(udp_tap_map[V6][dst].flags & PORT_LOCAL) || - (udp_tap_map[V6][dst].flags & PORT_LOOPBACK)) - s_in6.sin6_addr = in6addr_loopback; - else if (udp_tap_map[V6][dst].flags & PORT_GUA) - s_in6.sin6_addr = c->ip6.addr; - else - s_in6.sin6_addr = c->ip6.addr_seen; - } else if (IN6_IS_ADDR_LINKLOCAL(&s_in6.sin6_addr)) { - bind_addr = &c->ip6.addr_ll; - } - - if ((s = udp_tap_map[V6][src].sock) < 0) { - union udp_epoll_ref uref = { - .v6 = 1, - .port = src, - .pif = PIF_HOST, - }; - const char *bind_if = NULL; + tosidx = udp_flow_from_tap(c, pif, af, saddr, daddr, src, dst, now); + if (!(uflow = udp_at_sidx(tosidx))) { + char sstr[INET6_ADDRSTRLEN], dstr[INET6_ADDRSTRLEN]; - if (!IN6_IS_ADDR_LOOPBACK(&s_in6.sin6_addr)) - bind_if = c->ip6.ifname_out; + debug("Dropping datagram with no flow %s %s:%hu -> %s:%hu", + pif_name(pif), + inet_ntop(af, saddr, sstr, sizeof(sstr)), src, + inet_ntop(af, daddr, dstr, sizeof(dstr)), dst); + return 1; + } - if (!IN6_IS_ADDR_LOOPBACK(&s_in6.sin6_addr) && - !IN6_IS_ADDR_LINKLOCAL(&s_in6.sin6_addr)) - bind_addr = &c->ip6.addr_out; + topif = pif_at_sidx(tosidx); + if (topif != PIF_HOST) { + flow_sidx_t fromsidx = flow_sidx_opposite(tosidx); + uint8_t frompif = pif_at_sidx(fromsidx); - s = sock_l4(c, AF_INET6, IPPROTO_UDP, bind_addr, - bind_if, src, uref.u32); - if (s < 0) - return p->count - idx; + flow_err(uflow, "No support for forwarding UDP from %s to %s", + pif_name(frompif), pif_name(topif)); + return 1; + } + toside = flowside_at_sidx(tosidx); - udp_tap_map[V6][src].sock = s; - bitmap_set(udp_act[V6][UDP_ACT_TAP], src); - } + s = udp_at_sidx(tosidx)->s[tosidx.sidei]; + ASSERT(s >= 0); - udp_tap_map[V6][src].ts = now->tv_sec; - } + pif_sockaddr(c, &to_sa, &sl, topif, &toside->eaddr, toside->eport); for (i = 0; i < (int)p->count - idx; i++) { struct udphdr *uh_send; @@ -968,7 +790,7 @@ int udp_tap_handler(struct ctx *c, uint8_t pif, if (!uh_send) return p->count - idx; - mm[i].msg_hdr.msg_name = sa; + mm[i].msg_hdr.msg_name = &to_sa; mm[i].msg_hdr.msg_namelen = sl; if (len) { @@ -1000,56 +822,62 @@ int udp_tap_handler(struct ctx *c, uint8_t pif, * udp_sock_init() - Initialise listening sockets for a given port * @c: Execution context * @ns: In pasta mode, if set, bind with loopback address in namespace - * @af: Address family to select a specific IP version, or AF_UNSPEC * @addr: Pointer to address for binding, NULL if not configured * @ifname: Name of interface to bind to, NULL if not configured * @port: Port, host order * * Return: 0 on (partial) success, negative error code on (complete) failure */ -int udp_sock_init(const struct ctx *c, int ns, sa_family_t af, - const void *addr, const char *ifname, in_port_t port) +int udp_sock_init(const struct ctx *c, int ns, const union inany_addr *addr, + const char *ifname, in_port_t port) { - union udp_epoll_ref uref = { .splice = (c->mode == MODE_PASTA), - .orig = true, .port = port }; - int s, r4 = FD_REF_MAX + 1, r6 = FD_REF_MAX + 1; - - if (ns) - uref.pif = PIF_SPLICE; - else - uref.pif = PIF_HOST; - - if ((af == AF_INET || af == AF_UNSPEC) && c->ifi4) { - uref.v6 = 0; + union udp_listen_epoll_ref uref = { + .pif = ns ? PIF_SPLICE : PIF_HOST, + .port = port, + }; + int r4 = FD_REF_MAX + 1, r6 = FD_REF_MAX + 1; + + ASSERT(!c->no_udp); + + if (!addr && c->ifi4 && c->ifi6 && !ns) { + int s; + + /* Attempt to get a dual stack socket */ + s = pif_sock_l4(c, EPOLL_TYPE_UDP_LISTEN, PIF_HOST, + NULL, ifname, port, uref.u32); + udp_splice_init[V4][port] = s < 0 ? -1 : s; + udp_splice_init[V6][port] = s < 0 ? -1 : s; + if (IN_INTERVAL(0, FD_REF_MAX, s)) + return 0; + } + if ((!addr || inany_v4(addr)) && c->ifi4) { if (!ns) { - r4 = s = sock_l4(c, AF_INET, IPPROTO_UDP, addr, - ifname, port, uref.u32); + r4 = pif_sock_l4(c, EPOLL_TYPE_UDP_LISTEN, PIF_HOST, + addr ? addr : &inany_any4, ifname, + port, uref.u32); - udp_tap_map[V4][uref.port].sock = s < 0 ? -1 : s; - udp_splice_init[V4][port].sock = s < 0 ? -1 : s; + udp_splice_init[V4][port] = r4 < 0 ? -1 : r4; } else { - r4 = s = sock_l4(c, AF_INET, IPPROTO_UDP, - &in4addr_loopback, - ifname, port, uref.u32); - udp_splice_ns[V4][port].sock = s < 0 ? -1 : s; + r4 = pif_sock_l4(c, EPOLL_TYPE_UDP_LISTEN, PIF_SPLICE, + &inany_loopback4, ifname, + port, uref.u32); + udp_splice_ns[V4][port] = r4 < 0 ? -1 : r4; } } - if ((af == AF_INET6 || af == AF_UNSPEC) && c->ifi6) { - uref.v6 = 1; - + if ((!addr || !inany_v4(addr)) && c->ifi6) { if (!ns) { - r6 = s = sock_l4(c, AF_INET6, IPPROTO_UDP, addr, - ifname, port, uref.u32); + r6 = pif_sock_l4(c, EPOLL_TYPE_UDP_LISTEN, PIF_HOST, + addr ? addr : &inany_any6, ifname, + port, uref.u32); - udp_tap_map[V6][uref.port].sock = s < 0 ? -1 : s; - udp_splice_init[V6][port].sock = s < 0 ? -1 : s; + udp_splice_init[V6][port] = r6 < 0 ? -1 : r6; } else { - r6 = s = sock_l4(c, AF_INET6, IPPROTO_UDP, - &in6addr_loopback, - ifname, port, uref.u32); - udp_splice_ns[V6][port].sock = s < 0 ? -1 : s; + r6 = pif_sock_l4(c, EPOLL_TYPE_UDP_LISTEN, PIF_SPLICE, + &inany_loopback6, ifname, + port, uref.u32); + udp_splice_ns[V6][port] = r6 < 0 ? -1 : r6; } } @@ -1067,73 +895,15 @@ static void udp_splice_iov_init(void) int i; for (i = 0; i < UDP_MAX_FRAMES; i++) { - struct msghdr *mh4 = &udp4_mh_splice[i].msg_hdr; - struct msghdr *mh6 = &udp6_mh_splice[i].msg_hdr; - - mh4->msg_name = &udp4_localname; - mh4->msg_namelen = sizeof(udp4_localname); + struct msghdr *mh = &udp_mh_splice[i].msg_hdr; - mh6->msg_name = &udp6_localname; - mh6->msg_namelen = sizeof(udp6_localname); + mh->msg_name = &udp_splice_to; + mh->msg_namelen = sizeof(udp_splice_to); - udp4_iov_splice[i].iov_base = udp4_l2_buf[i].data; - udp6_iov_splice[i].iov_base = udp6_l2_buf[i].data; + udp_iov_splice[i].iov_base = udp_payload[i].data; - mh4->msg_iov = &udp4_iov_splice[i]; - mh6->msg_iov = &udp6_iov_splice[i]; - mh4->msg_iovlen = mh6->msg_iovlen = 1; - } -} - -/** - * udp_timer_one() - Handler for timed events on one port - * @c: Execution context - * @v6: Set for IPv6 connections - * @type: Socket type - * @port: Port number, host order - * @now: Current timestamp - */ -static void udp_timer_one(struct ctx *c, int v6, enum udp_act_type type, - in_port_t port, const struct timespec *now) -{ - struct udp_splice_port *sp; - struct udp_tap_port *tp; - int *sockp = NULL; - - switch (type) { - case UDP_ACT_TAP: - tp = &udp_tap_map[v6 ? V6 : V4][port]; - - if (now->tv_sec - tp->ts > UDP_CONN_TIMEOUT) { - sockp = &tp->sock; - tp->flags = 0; - } - - break; - case UDP_ACT_SPLICE_INIT: - sp = &udp_splice_init[v6 ? V6 : V4][port]; - - if (now->tv_sec - sp->ts > UDP_CONN_TIMEOUT) - sockp = &sp->sock; - - break; - case UDP_ACT_SPLICE_NS: - sp = &udp_splice_ns[v6 ? V6 : V4][port]; - - if (now->tv_sec - sp->ts > UDP_CONN_TIMEOUT) - sockp = &sp->sock; - - break; - default: - return; - } - - if (sockp && *sockp >= 0) { - int s = *sockp; - *sockp = -1; - epoll_ctl(c->epollfd, EPOLL_CTL_DEL, s, NULL); - close(s); - bitmap_clear(udp_act[v6 ? V6 : V4][type], port); + mh->msg_iov = &udp_iov_splice[i]; + mh->msg_iovlen = 1; } } @@ -1146,24 +916,23 @@ static void udp_timer_one(struct ctx *c, int v6, enum udp_act_type type, */ static void udp_port_rebind(struct ctx *c, bool outbound) { + int (*socks)[NUM_PORTS] = outbound ? udp_splice_ns : udp_splice_init; const uint8_t *fmap - = outbound ? c->udp.fwd_out.f.map : c->udp.fwd_in.f.map; + = outbound ? c->udp.fwd_out.map : c->udp.fwd_in.map; const uint8_t *rmap - = outbound ? c->udp.fwd_in.f.map : c->udp.fwd_out.f.map; - struct udp_splice_port (*socks)[NUM_PORTS] - = outbound ? udp_splice_ns : udp_splice_init; + = outbound ? c->udp.fwd_in.map : c->udp.fwd_out.map; unsigned port; for (port = 0; port < NUM_PORTS; port++) { if (!bitmap_isset(fmap, port)) { - if (socks[V4][port].sock >= 0) { - close(socks[V4][port].sock); - socks[V4][port].sock = -1; + if (socks[V4][port] >= 0) { + close(socks[V4][port]); + socks[V4][port] = -1; } - if (socks[V6][port].sock >= 0) { - close(socks[V6][port].sock); - socks[V6][port].sock = -1; + if (socks[V6][port] >= 0) { + close(socks[V6][port]); + socks[V6][port] = -1; } continue; @@ -1173,9 +942,9 @@ static void udp_port_rebind(struct ctx *c, bool outbound) if (bitmap_isset(rmap, port)) continue; - if ((c->ifi4 && socks[V4][port].sock == -1) || - (c->ifi6 && socks[V6][port].sock == -1)) - udp_sock_init(c, outbound, AF_UNSPEC, NULL, NULL, port); + if ((c->ifi4 && socks[V4][port] == -1) || + (c->ifi6 && socks[V6][port] == -1)) + udp_sock_init(c, outbound, NULL, NULL, port); } } @@ -1204,43 +973,23 @@ static int udp_port_rebind_outbound(void *arg) */ void udp_timer(struct ctx *c, const struct timespec *now) { - int n, t, v6 = 0; - unsigned int i; - long *word, tmp; + (void)now; + + ASSERT(!c->no_udp); if (c->mode == MODE_PASTA) { - if (c->udp.fwd_out.f.mode == FWD_AUTO) { - fwd_scan_ports_udp(&c->udp.fwd_out.f, &c->udp.fwd_in.f, + if (c->udp.fwd_out.mode == FWD_AUTO) { + fwd_scan_ports_udp(&c->udp.fwd_out, &c->udp.fwd_in, &c->tcp.fwd_out, &c->tcp.fwd_in); NS_CALL(udp_port_rebind_outbound, c); } - if (c->udp.fwd_in.f.mode == FWD_AUTO) { - fwd_scan_ports_udp(&c->udp.fwd_in.f, &c->udp.fwd_out.f, + if (c->udp.fwd_in.mode == FWD_AUTO) { + fwd_scan_ports_udp(&c->udp.fwd_in, &c->udp.fwd_out, &c->tcp.fwd_in, &c->tcp.fwd_out); udp_port_rebind(c, false); } } - - if (!c->ifi4) - v6 = 1; -v6: - for (t = 0; t < UDP_ACT_TYPE_MAX; t++) { - word = (long *)udp_act[v6 ? V6 : V4][t]; - for (i = 0; i < ARRAY_SIZE(udp_act[0][0]); - i += sizeof(long), word++) { - tmp = *word; - while ((n = ffsl(tmp))) { - tmp &= ~(1UL << (n - 1)); - udp_timer_one(c, v6, t, i * 8 + n - 1, now); - } - } - } - - if (!v6 && c->ifi6) { - v6 = 1; - goto v6; - } } /** @@ -1251,14 +1000,9 @@ v6: */ int udp_init(struct ctx *c) { - if (c->ifi4) - udp_sock4_iov_init(c); - - if (c->ifi6) - udp_sock6_iov_init(c); + ASSERT(!c->no_udp); - udp_invert_portmap(&c->udp.fwd_in); - udp_invert_portmap(&c->udp.fwd_out); + udp_iov_init(c); if (c->mode == MODE_PASTA) { udp_splice_iov_init(); |