diff options
| -rw-r--r-- | flow.c | 2 | ||||
| -rw-r--r-- | udp.c | 4 | ||||
| -rw-r--r-- | udp_flow.c | 75 | ||||
| -rw-r--r-- | udp_flow.h | 6 | ||||
| -rw-r--r-- | udp_internal.h | 2 |
5 files changed, 63 insertions, 26 deletions
@@ -850,7 +850,7 @@ void flow_defer_handler(const struct ctx *c, const struct timespec *now) closed = icmp_ping_timer(c, &flow->ping, now); break; case FLOW_UDP: - closed = udp_flow_defer(&flow->udp); + closed = udp_flow_defer(c, &flow->udp, now); if (!closed && timer) closed = udp_flow_timer(c, &flow->udp, now); break; @@ -698,8 +698,8 @@ static void udp_buf_sock_to_tap(const struct ctx *c, int s, int n, * @port: Our (local) port number of @s * @now: Current timestamp */ -static void udp_sock_fwd(const struct ctx *c, int s, uint8_t frompif, - in_port_t port, const struct timespec *now) +void udp_sock_fwd(const struct ctx *c, int s, uint8_t frompif, + in_port_t port, const struct timespec *now) { union sockaddr_inany src; @@ -9,10 +9,12 @@ #include <fcntl.h> #include <sys/uio.h> #include <unistd.h> +#include <netinet/udp.h> #include "util.h" #include "passt.h" #include "flow_table.h" +#include "udp_internal.h" #define UDP_CONN_TIMEOUT 180 /* s, timeout for ephemeral or local bind */ @@ -67,16 +69,15 @@ void udp_flow_close(const struct ctx *c, struct udp_flow *uflow) * Return: fd of new socket on success, -ve error code on failure */ static int udp_flow_sock(const struct ctx *c, - const struct udp_flow *uflow, unsigned sidei) + struct udp_flow *uflow, unsigned sidei) { const struct flowside *side = &uflow->f.side[sidei]; - struct mmsghdr discard[UIO_MAXIOV] = { 0 }; uint8_t pif = uflow->f.pif[sidei]; union { flow_sidx_t sidx; uint32_t data; } fref = { .sidx = FLOW_SIDX(uflow, sidei) }; - int rc, s; + int s; s = flowside_sock_l4(c, EPOLL_TYPE_UDP, pif, side, fref.data); if (s < 0) { @@ -85,30 +86,32 @@ static int udp_flow_sock(const struct ctx *c, } if (flowside_connect(c, s, pif, side) < 0) { - rc = -errno; + int rc = -errno; flow_dbg_perror(uflow, "Couldn't connect flow socket"); return rc; } - /* It's possible, if unlikely, that we could receive some unrelated - * packets in between the bind() and connect() of this socket. For now - * we just discard these. + /* It's possible, if unlikely, that we could receive some packets in + * between the bind() and connect() which may or may not be for this + * flow. Being UDP we could just discard them, but it's not ideal. * - * FIXME: Redirect these to an appropriate handler + * There's also a tricky case if a bunch of datagrams for a new flow + * arrive in rapid succession, the first going to the original listening + * socket and later ones going to this new socket. If we forwarded the + * datagrams from the new socket immediately here they would go before + * the datagram which established the flow. Again, not strictly wrong + * for UDP, but not ideal. + * + * So, we flag that the new socket is in a transient state where it + * might have datagrams for a different flow queued. Before the next + * epoll cycle, udp_flow_defer() will flush out any such datagrams, and + * thereafter everything on the new socket should be strictly for this + * flow. */ - rc = recvmmsg(s, discard, ARRAY_SIZE(discard), MSG_DONTWAIT, NULL); - if (rc >= ARRAY_SIZE(discard)) { - flow_dbg(uflow, "Too many (%d) spurious reply datagrams", rc); - return -E2BIG; - } - - if (rc > 0) { - flow_trace(uflow, "Discarded %d spurious reply datagrams", rc); - } else if (errno != EAGAIN) { - rc = -errno; - flow_perror(uflow, "Unexpected error discarding datagrams"); - return rc; - } + if (sidei) + uflow->flush1 = true; + else + uflow->flush0 = true; return s; } @@ -269,13 +272,41 @@ flow_sidx_t udp_flow_from_tap(const struct ctx *c, } /** + * udp_flush_flow() - Flush datagrams that might not be for this flow + * @c: Execution context + * @uflow: Flow to handle + * @sidei: Side of the flow to flush + * @now: Current timestamp + */ +static void udp_flush_flow(const struct ctx *c, + const struct udp_flow *uflow, unsigned sidei, + const struct timespec *now) +{ + /* We don't know exactly where the datagrams will come from, but we know + * they'll have an interface and oport matching this flow */ + udp_sock_fwd(c, uflow->s[sidei], uflow->f.pif[sidei], + uflow->f.side[sidei].oport, now); +} + +/** * udp_flow_defer() - Deferred per-flow handling (clean up aborted flows) + * @c: Execution context * @uflow: Flow to handle + * @now: Current timestamp * * Return: true if the connection is ready to free, false otherwise */ -bool udp_flow_defer(const struct udp_flow *uflow) +bool udp_flow_defer(const struct ctx *c, struct udp_flow *uflow, + const struct timespec *now) { + if (uflow->flush0) { + udp_flush_flow(c, uflow, INISIDE, now); + uflow->flush0 = false; + } + if (uflow->flush1) { + udp_flush_flow(c, uflow, TGTSIDE, now); + uflow->flush1 = false; + } return uflow->closed; } @@ -11,6 +11,8 @@ * struct udp_flow - Descriptor for a flow of UDP packets * @f: Generic flow information * @closed: Flow is already closed + * @flush0: @s[0] may have datagrams queued for other flows + * @flush1: @s[1] may have datagrams queued for other flows * @ts: Activity timestamp * @s: Socket fd (or -1) for each side of the flow * @ttl: TTL or hop_limit for both sides @@ -20,6 +22,7 @@ struct udp_flow { struct flow_common f; bool closed :1; + bool flush0, flush1 :1; time_t ts; int s[SIDES]; uint8_t ttl[SIDES]; @@ -35,7 +38,8 @@ flow_sidx_t udp_flow_from_tap(const struct ctx *c, in_port_t srcport, in_port_t dstport, const struct timespec *now); void udp_flow_close(const struct ctx *c, struct udp_flow *uflow); -bool udp_flow_defer(const struct udp_flow *uflow); +bool udp_flow_defer(const struct ctx *c, struct udp_flow *uflow, + const struct timespec *now); bool udp_flow_timer(const struct ctx *c, struct udp_flow *uflow, const struct timespec *now); diff --git a/udp_internal.h b/udp_internal.h index f7d8426..96d11cf 100644 --- a/udp_internal.h +++ b/udp_internal.h @@ -28,5 +28,7 @@ size_t udp_update_hdr4(struct iphdr *ip4h, struct udp_payload_t *bp, size_t udp_update_hdr6(struct ipv6hdr *ip6h, struct udp_payload_t *bp, const struct flowside *toside, size_t dlen, bool no_udp_csum); +void udp_sock_fwd(const struct ctx *c, int s, uint8_t frompif, + in_port_t port, const struct timespec *now); #endif /* UDP_INTERNAL_H */ |