[Still partial review] On Thu, 10 Oct 2024 14:29:01 +0200 Laurent Vivier <lvivier(a)redhat.com> wrote:add virtio and vhost-user functions to connect with QEMU. $ ./passt --vhost-user and # qemu-system-x86_64 ... -m 4G \ -object memory-backend-memfd,id=memfd0,share=on,size=4G \ -numa node,memdev=memfd0 \ -chardev socket,id=chr0,path=/tmp/passt_1.socket \ -netdev vhost-user,id=netdev0,chardev=chr0 \ -device virtio-net,mac=9a:2b:2c:2d:2e:2f,netdev=netdev0 \ ... Signed-off-by: Laurent Vivier <lvivier(a)redhat.com> --- Makefile | 6 +- conf.c | 21 ++- epoll_type.h | 4 + iov.c | 1 - isolation.c | 15 +- packet.c | 11 ++ packet.h | 8 +- passt.1 | 10 +- passt.c | 9 + passt.h | 6 + pcap.c | 1 - tap.c | 80 +++++++-- tap.h | 5 +- tcp.c | 7 + tcp_vu.c | 476 +++++++++++++++++++++++++++++++++++++++++++++++++++ tcp_vu.h | 12 ++ udp.c | 10 ++ udp_vu.c | 336 ++++++++++++++++++++++++++++++++++++ udp_vu.h | 13 ++ vhost_user.c | 37 ++-- vhost_user.h | 4 +- virtio.c | 5 - vu_common.c | 385 +++++++++++++++++++++++++++++++++++++++++ vu_common.h | 47 +++++ 24 files changed, 1454 insertions(+), 55 deletions(-) create mode 100644 tcp_vu.c create mode 100644 tcp_vu.h create mode 100644 udp_vu.c create mode 100644 udp_vu.h create mode 100644 vu_common.c create mode 100644 vu_common.h diff --git a/Makefile b/Makefile index 0e8ed60a0da1..1e8910dda1f4 100644 --- a/Makefile +++ b/Makefile @@ -54,7 +54,8 @@ FLAGS += -DDUAL_STACK_SOCKETS=$(DUAL_STACK_SOCKETS) PASST_SRCS = arch.c arp.c checksum.c conf.c dhcp.c dhcpv6.c flow.c fwd.c \ icmp.c igmp.c inany.c iov.c ip.c isolation.c lineread.c log.c mld.c \ ndp.c netlink.c packet.c passt.c pasta.c pcap.c pif.c tap.c tcp.c \ - tcp_buf.c tcp_splice.c udp.c udp_flow.c util.c vhost_user.c virtio.c + tcp_buf.c tcp_splice.c tcp_vu.c udp.c udp_flow.c udp_vu.c util.c \ + vhost_user.c virtio.c vu_common.c QRAP_SRCS = qrap.c SRCS = $(PASST_SRCS) $(QRAP_SRCS) @@ -64,7 +65,8 @@ PASST_HEADERS = arch.h arp.h checksum.h conf.h dhcp.h dhcpv6.h flow.h fwd.h \ flow_table.h icmp.h icmp_flow.h inany.h iov.h ip.h isolation.h \ lineread.h log.h ndp.h netlink.h packet.h passt.h pasta.h pcap.h pif.h \ siphash.h tap.h tcp.h tcp_buf.h tcp_conn.h tcp_internal.h tcp_splice.h \ - udp.h udp_flow.h util.h vhost_user.h virtio.h + tcp_vu.h udp.h udp_flow.h udp_internal.h udp_vu.h util.h vhost_user.h \ + virtio.h vu_common.h HEADERS = $(PASST_HEADERS) seccomp.h C := \#include <linux/tcp.h>\nstruct tcp_info x = { .tcpi_snd_wnd = 0 }; diff --git a/conf.c b/conf.c index c63101970155..29d6e41f5770 100644 --- a/conf.c +++ b/conf.c @@ -45,6 +45,7 @@ #include "lineread.h" #include "isolation.h" #include "log.h" +#include "vhost_user.h" /** * next_chunk - Return the next piece of a string delimited by a character @@ -762,9 +763,14 @@ static void usage(const char *name, FILE *f, int status) " default: same interface name as external one\n"); } else { fprintf(f, - " -s, --socket PATH UNIX domain socket path\n" + " -s, --socket, --socket-path PATH UNIX domain socket path\n" " default: probe free path starting from " UNIX_SOCK_PATH "\n", 1); + fprintf(f, + " --vhost-user Enable vhost-user mode\n" + " UNIX domain socket is provided by -s option\n" + " --print-capabilities print back-end capabilities in JSON format,\n" + " only meaningful for vhost-user mode\n"); } fprintf(f, @@ -1290,6 +1296,10 @@ void conf(struct ctx *c, int argc, char **argv) {"map-host-loopback", required_argument, NULL, 21 }, {"map-guest-addr", required_argument, NULL, 22 }, {"dns-host", required_argument, NULL, 24 }, + {"vhost-user", no_argument, NULL, 25 }, + /* vhost-user backend program convention */ + {"print-capabilities", no_argument, NULL, 26 }, + {"socket-path", required_argument, NULL, 's' }, { 0 }, }; const char *logname = (c->mode == MODE_PASTA) ? "pasta" : "passt"; @@ -1478,6 +1488,15 @@ void conf(struct ctx *c, int argc, char **argv) break; die("Invalid host nameserver address: %s", optarg); + case 25: + if (c->mode == MODE_PASTA) { + err("--vhost-user is for passt mode only"); + usage(argv[0], stdout, EXIT_SUCCESS);This shouldn't exit with EXIT_SUCCESS: it's not supported for pasta so it's an error (see all the other cases like this one): die("--vhost-user is for passt mode only");+ } + c->mode = MODE_VU; + break; + case 26: + vu_print_capabilities(); break; case 'd': c->debug = 1; diff --git a/epoll_type.h b/epoll_type.h index 0ad1efa0ccec..f3ef41584757 100644 --- a/epoll_type.h +++ b/epoll_type.h @@ -36,6 +36,10 @@ enum epoll_type { EPOLL_TYPE_TAP_PASST, /* socket listening for qemu socket connections */ EPOLL_TYPE_TAP_LISTEN, + /* vhost-user command socket */ + EPOLL_TYPE_VHOST_CMD, + /* vhost-user kick event socket */ + EPOLL_TYPE_VHOST_KICK, EPOLL_NUM_TYPES, }; diff --git a/iov.c b/iov.c index 3f9e229a305f..3741db21790f 100644 --- a/iov.c +++ b/iov.c @@ -68,7 +68,6 @@ size_t iov_skip_bytes(const struct iovec *iov, size_t n, * * Returns: The number of bytes successfully copied. */ -/* cppcheck-suppress unusedFunction */ size_t iov_from_buf(const struct iovec *iov, size_t iov_cnt, size_t offset, const void *buf, size_t bytes) { diff --git a/isolation.c b/isolation.c index 45fba1e68b9d..c2a3c7b7911d 100644 --- a/isolation.c +++ b/isolation.c @@ -379,12 +379,19 @@ void isolate_postfork(const struct ctx *c) prctl(PR_SET_DUMPABLE, 0); - if (c->mode == MODE_PASTA) { - prog.len = (unsigned short)ARRAY_SIZE(filter_pasta); - prog.filter = filter_pasta; - } else { + switch (c->mode) { + case MODE_PASST: prog.len = (unsigned short)ARRAY_SIZE(filter_passt); prog.filter = filter_passt; + break; + case MODE_PASTA: + prog.len = (unsigned short)ARRAY_SIZE(filter_pasta); + prog.filter = filter_pasta; + break; + case MODE_VU: + prog.len = (unsigned short)ARRAY_SIZE(filter_vu); + prog.filter = filter_vu; + break; } if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) || diff --git a/packet.c b/packet.c index 37489961a37e..e5a78d079231 100644 --- a/packet.c +++ b/packet.c @@ -36,6 +36,17 @@ static int packet_check_range(const struct pool *p, size_t offset, size_t len, const char *start, const char *func, int line) { + if (p->buf_size == 0) { + int ret; + + ret = vu_packet_check_range((void *)p->buf, offset, len, start); + + if (ret == -1) + trace("cannot find region, %s:%i", func, line); + + return ret; + } + if (start < p->buf) { trace("packet start %p before buffer start %p, " "%s:%i", (void *)start, (void *)p->buf, func, line); diff --git a/packet.h b/packet.h index 8377dcf678bb..3f70e949c066 100644 --- a/packet.h +++ b/packet.h @@ -8,8 +8,10 @@ /** * struct pool - Generic pool of packets stored in a buffer - * @buf: Buffer storing packet descriptors - * @buf_size: Total size of buffer + * @buf: Buffer storing packet descriptors, + * a struct vu_dev_region array for passt vhost-user mode + * @buf_size: Total size of buffer, + * 0 for passt vhost-user mode * @size: Number of usable descriptors for the pool * @count: Number of used descriptors for the pool * @pkt: Descriptors: see macros below @@ -22,6 +24,8 @@ struct pool { struct iovec pkt[1]; }; +int vu_packet_check_range(void *buf, size_t offset, size_t len, + const char *start); void packet_add_do(struct pool *p, size_t len, const char *start, const char *func, int line); void *packet_get_do(const struct pool *p, const size_t idx, diff --git a/passt.1 b/passt.1 index ef33267e9cd7..96532dd39aa2 100644 --- a/passt.1 +++ b/passt.1 @@ -397,12 +397,20 @@ interface address are configured on a given host interface. .SS \fBpasst\fR-only options .TP -.BR \-s ", " \-\-socket " " \fIpath +.BR \-s ", " \-\-socket-path ", " \-\-socket " " \fIpath Path for UNIX domain socket used by \fBqemu\fR(1) or \fBqrap\fR(1) to connect to \fBpasst\fR. Default is to probe a free socket, not accepting connections, starting from \fI/tmp/passt_1.socket\fR to \fI/tmp/passt_64.socket\fR. +.TP +.BR \-\-vhost-user +Enable vhost-user. The vhost-user command socket is provided by \fB--socket\fR. + +.TP +.BR \-\-print-capabilities +Print back-end capabilities in JSON format, only meaningful for vhost-user mode. + .TP .BR \-F ", " \-\-fd " " \fIFD Pass a pre-opened, connected socket to \fBpasst\fR. Usually the socket is opened diff --git a/passt.c b/passt.c index 79093ee02d62..2d105e81218d 100644 --- a/passt.c +++ b/passt.c @@ -52,6 +52,7 @@ #include "arch.h" #include "log.h" #include "tcp_splice.h" +#include "vu_common.h" #define EPOLL_EVENTS 8 @@ -74,6 +75,8 @@ char *epoll_type_str[] = { [EPOLL_TYPE_TAP_PASTA] = "/dev/net/tun device", [EPOLL_TYPE_TAP_PASST] = "connected qemu socket", [EPOLL_TYPE_TAP_LISTEN] = "listening qemu socket", + [EPOLL_TYPE_VHOST_CMD] = "vhost-user command socket", + [EPOLL_TYPE_VHOST_KICK] = "vhost-user kick socket", }; static_assert(ARRAY_SIZE(epoll_type_str) == EPOLL_NUM_TYPES, "epoll_type_str[] doesn't match enum epoll_type"); @@ -360,6 +363,12 @@ loop: case EPOLL_TYPE_PING: icmp_sock_handler(&c, ref); break; + case EPOLL_TYPE_VHOST_CMD: + vu_control_handler(c.vdev, c.fd_tap, eventmask); + break; + case EPOLL_TYPE_VHOST_KICK: + vu_kick_cb(c.vdev, ref, &now); + break; default: /* Can't happen */ ASSERT(0); diff --git a/passt.h b/passt.h index 4908ed937dc8..311482d36257 100644 --- a/passt.h +++ b/passt.h @@ -25,6 +25,8 @@ union epoll_ref; #include "fwd.h" #include "tcp.h" #include "udp.h" +#include "udp_vu.h" +#include "vhost_user.h" /* Default address for our end on the tap interface. Bit 0 of byte 0 must be 0 * (unicast) and bit 1 of byte 1 must be 1 (locally administered). Otherwise @@ -94,6 +96,7 @@ struct fqdn { enum passt_modes { MODE_PASST, MODE_PASTA, + MODE_VU, }; /** @@ -228,6 +231,7 @@ struct ip6_ctx { * @freebind: Allow binding of non-local addresses for forwarding * @low_wmem: Low probed net.core.wmem_max * @low_rmem: Low probed net.core.rmem_max + * @vdev: vhost-user device */ struct ctx { enum passt_modes mode; @@ -289,6 +293,8 @@ struct ctx { int low_wmem; int low_rmem; + + struct vu_dev *vdev; }; void proto_update_l2_buf(const unsigned char *eth_d, diff --git a/pcap.c b/pcap.c index 6ee6cdfd261a..718d6ad61732 100644 --- a/pcap.c +++ b/pcap.c @@ -140,7 +140,6 @@ void pcap_multiple(const struct iovec *iov, size_t frame_parts, unsigned int n, * @iovcnt: Number of buffers (@iov entries) * @offset: Offset of the L2 frame within the full data length */ -/* cppcheck-suppress unusedFunction */ void pcap_iov(const struct iovec *iov, size_t iovcnt, size_t offset) { struct timespec now; diff --git a/tap.c b/tap.c index 4b826fdf7adc..22d19f1833f7 100644 --- a/tap.c +++ b/tap.c @@ -58,6 +58,8 @@ #include "packet.h" #include "tap.h" #include "log.h" +#include "vhost_user.h" +#include "vu_common.h" /* IPv4 (plus ARP) and IPv6 message batches from tap/guest to IP handlers */ static PACKET_POOL_NOINIT(pool_tap4, TAP_MSGS, pkt_buf); @@ -78,16 +80,22 @@ void tap_send_single(const struct ctx *c, const void *data, size_t l2len) struct iovec iov[2]; size_t iovcnt = 0; - if (c->mode == MODE_PASST) { + switch (c->mode) { + case MODE_PASST: iov[iovcnt] = IOV_OF_LVALUE(vnet_len); iovcnt++; - } - - iov[iovcnt].iov_base = (void *)data; - iov[iovcnt].iov_len = l2len; - iovcnt++; + /* fall through */ + case MODE_PASTA: + iov[iovcnt].iov_base = (void *)data; + iov[iovcnt].iov_len = l2len; + iovcnt++; - tap_send_frames(c, iov, iovcnt, 1); + tap_send_frames(c, iov, iovcnt, 1); + break; + case MODE_VU: + vu_send_single(c, data, l2len); + break; + } } /** @@ -414,10 +422,18 @@ size_t tap_send_frames(const struct ctx *c, const struct iovec *iov, if (!nframes) return 0; - if (c->mode == MODE_PASTA) + switch (c->mode) { + case MODE_PASTA: m = tap_send_frames_pasta(c, iov, bufs_per_frame, nframes); - else + break; + case MODE_PASST: m = tap_send_frames_passt(c, iov, bufs_per_frame, nframes); + break; + case MODE_VU: + /* fall through */ + default: + ASSERT(0); + } if (m < nframes) debug("tap: failed to send %zu frames of %zu", @@ -976,7 +992,7 @@ void tap_add_packet(struct ctx *c, ssize_t l2len, char *p) * tap_sock_reset() - Handle closing or failure of connect AF_UNIX socket * @c: Execution context */ -static void tap_sock_reset(struct ctx *c) +void tap_sock_reset(struct ctx *c) { info("Client connection closed%s", c->one_off ? ", exiting" : ""); @@ -987,6 +1003,8 @@ static void tap_sock_reset(struct ctx *c) epoll_ctl(c->epollfd, EPOLL_CTL_DEL, c->fd_tap, NULL); close(c->fd_tap); c->fd_tap = -1; + if (c->mode == MODE_VU) + vu_cleanup(c->vdev); } /** @@ -1205,6 +1223,11 @@ static void tap_backend_show_hints(struct ctx *c) info("or qrap, for earlier qemu versions:"); info(" ./qrap 5 kvm ... -net socket,fd=5 -net nic,model=virtio"); break; + case MODE_VU: + info("You can start qemu with:"); + info(" kvm ... -chardev socket,id=chr0,path=%s -netdev vhost-user,id=netdev0,chardev=chr0 -device virtio-net,netdev=netdev0 -object memory-backend-memfd,id=memfd0,share=on,size=$RAMSIZE -numa node,memdev=memfd0\n", + c->sock_path); + break; } } @@ -1232,8 +1255,8 @@ static void tap_sock_unix_init(const struct ctx *c) */ void tap_listen_handler(struct ctx *c, uint32_t events) { - union epoll_ref ref = { .type = EPOLL_TYPE_TAP_PASST }; struct epoll_event ev = { 0 }; + union epoll_ref ref = { 0 }; int v = INT_MAX / 2; struct ucred ucred; socklen_t len; @@ -1273,6 +1296,10 @@ void tap_listen_handler(struct ctx *c, uint32_t events) trace("tap: failed to set SO_SNDBUF to %i", v); ref.fd = c->fd_tap; + if (c->mode == MODE_VU) + ref.type = EPOLL_TYPE_VHOST_CMD; + else + ref.type = EPOLL_TYPE_TAP_PASST; ev.events = EPOLLIN | EPOLLRDHUP; ev.data.u64 = ref.u64; epoll_ctl(c->epollfd, EPOLL_CTL_ADD, c->fd_tap, &ev); @@ -1339,7 +1366,7 @@ static void tap_sock_tun_init(struct ctx *c) * @base: Buffer base * @size Buffer size */ -static void tap_sock_update_pool(void *base, size_t size) +void tap_sock_update_pool(void *base, size_t size) { int i; @@ -1353,13 +1380,15 @@ static void tap_sock_update_pool(void *base, size_t size) } /** - * tap_backend_init() - Create and set up AF_UNIX socket or - * tuntap file descriptor + * tap_sock_init() - Create and set up AF_UNIX socket or tuntap file descriptor * @c: Execution context */ void tap_backend_init(struct ctx *c) { - tap_sock_update_pool(pkt_buf, sizeof(pkt_buf)); + if (c->mode == MODE_VU) + tap_sock_update_pool(NULL, 0); + else + tap_sock_update_pool(pkt_buf, sizeof(pkt_buf)); if (c->fd_tap != -1) { /* Passed as --fd */ struct epoll_event ev = { 0 }; @@ -1367,10 +1396,17 @@ void tap_backend_init(struct ctx *c) ASSERT(c->one_off); ref.fd = c->fd_tap; - if (c->mode == MODE_PASST) + switch (c->mode) { + case MODE_PASST: ref.type = EPOLL_TYPE_TAP_PASST; - else + break; + case MODE_PASTA: ref.type = EPOLL_TYPE_TAP_PASTA; + break; + case MODE_VU: + ref.type = EPOLL_TYPE_VHOST_CMD; + break; + } ev.events = EPOLLIN | EPOLLRDHUP; ev.data.u64 = ref.u64; @@ -1378,9 +1414,14 @@ void tap_backend_init(struct ctx *c) return; } - if (c->mode == MODE_PASTA) { + switch (c->mode) { + case MODE_PASTA: tap_sock_tun_init(c); - } else { + break; + case MODE_VU: + vu_init(c); + /* fall through */ + case MODE_PASST: tap_sock_unix_init(c); /* In passt mode, we don't know the guest's MAC address until it @@ -1388,6 +1429,7 @@ void tap_backend_init(struct ctx *c) * first packets will reach it. */ memset(&c->guest_mac, 0xff, sizeof(c->guest_mac)); + break;Unrelated change (or left-over).} tap_backend_show_hints(c); diff --git a/tap.h b/tap.h index 8728cc5c09c3..dfbd8b9ebd72 100644 --- a/tap.h +++ b/tap.h @@ -40,7 +40,8 @@ static inline struct iovec tap_hdr_iov(const struct ctx *c, */ static inline void tap_hdr_update(struct tap_hdr *thdr, size_t l2len) { - thdr->vnet_len = htonl(l2len); + if (thdr) + thdr->vnet_len = htonl(l2len); } void tap_udp4_send(const struct ctx *c, struct in_addr src, in_port_t sport, @@ -68,6 +69,8 @@ void tap_handler_pasta(struct ctx *c, uint32_t events, void tap_handler_passt(struct ctx *c, uint32_t events, const struct timespec *now); int tap_sock_unix_open(char *sock_path); +void tap_sock_reset(struct ctx *c); +void tap_sock_update_pool(void *base, size_t size); void tap_backend_init(struct ctx *c); void tap_flush_pools(void); void tap_handler(struct ctx *c, const struct timespec *now); diff --git a/tcp.c b/tcp.c index eae02b1647e3..fd2def0d8a39 100644 --- a/tcp.c +++ b/tcp.c @@ -304,6 +304,7 @@ #include "flow_table.h" #include "tcp_internal.h" #include "tcp_buf.h" +#include "tcp_vu.h" /* MSS rounding: see SET_MSS() */ #define MSS_DEFAULT 536 @@ -1328,6 +1329,9 @@ int tcp_prepare_flags(const struct ctx *c, struct tcp_tap_conn *conn, static int tcp_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags) { + if (c->mode == MODE_VU) + return tcp_vu_send_flag(c, conn, flags); + return tcp_buf_send_flag(c, conn, flags); } @@ -1721,6 +1725,9 @@ static int tcp_sock_consume(const struct tcp_tap_conn *conn, uint32_t ack_seq) */ static int tcp_data_from_sock(const struct ctx *c, struct tcp_tap_conn *conn) { + if (c->mode == MODE_VU) + return tcp_vu_data_from_sock(c, conn); + return tcp_buf_data_from_sock(c, conn); } diff --git a/tcp_vu.c b/tcp_vu.c new file mode 100644 index 000000000000..1126fb39d138 --- /dev/null +++ b/tcp_vu.c @@ -0,0 +1,476 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* tcp_vu.c - TCP L2 vhost-user management functions + * + * Copyright Red Hat + * Author: Laurent Vivier <lvivier(a)redhat.com> + */ + +#include <errno.h> +#include <stddef.h> +#include <stdint.h> + +#include <netinet/ip.h> + +#include <sys/socket.h> + +#include <linux/tcp.h> +#include <linux/virtio_net.h> + +#include "util.h" +#include "ip.h" +#include "passt.h" +#include "siphash.h" +#include "inany.h" +#include "vhost_user.h" +#include "tcp.h" +#include "pcap.h" +#include "flow.h" +#include "tcp_conn.h" +#include "flow_table.h" +#include "tcp_vu.h" +#include "tap.h" +#include "tcp_internal.h" +#include "checksum.h" +#include "vu_common.h" + +static struct iovec iov_vu[VIRTQUEUE_MAX_SIZE + 1]; +static struct vu_virtq_element elem[VIRTQUEUE_MAX_SIZE]; + +/** + * tcp_vu_l2_hdrlen() - return the size of the header in level 2 frame (TDP) + * @v6: Set for IPv6 packet + * + * Return: Return the size of the header + */ +static size_t tcp_vu_l2_hdrlen(bool v6) +{ + size_t l2_hdrlen; + + l2_hdrlen = sizeof(struct ethhdr) + sizeof(struct tcphdr); + + if (v6) + l2_hdrlen += sizeof(struct ipv6hdr); + else + l2_hdrlen += sizeof(struct iphdr); + + return l2_hdrlen; +} + +/** + * tcp_vu_update_check() - Calculate TCP checksum + * @tapside: Address information for one side of the flow + * @iov: Pointer to the array of IO vectors + * @iov_used: Length of the array + */ +static void tcp_vu_update_check(const struct flowside *tapside, + struct iovec *iov, int iov_used) +{ + char *base = iov[0].iov_base; + + if (inany_v4(&tapside->oaddr)) { + const struct iphdr *iph = vu_ip(base); + + tcp_update_check_tcp4(iph, iov, iov_used, + (char *)vu_payloadv4(base) - base); + } else { + const struct ipv6hdr *ip6h = vu_ip(base); + + tcp_update_check_tcp6(ip6h, iov, iov_used, + (char *)vu_payloadv6(base) - base); + } +} + +/** + * tcp_vu_send_flag() - Send segment with flags to vhost-user (no payload) + * @c: Execution context + * @conn: Connection pointer + * @flags: TCP flags: if not set, send segment only if ACK is due + * + * Return: negative error code on connection reset, 0 otherwise + */ +int tcp_vu_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, int flags) +{ + struct vu_dev *vdev = c->vdev; + struct vu_virtq *vq = &vdev->vq[VHOST_USER_RX_QUEUE]; + const struct flowside *tapside = TAPFLOW(conn); + size_t l2len, l4len, optlen, hdrlen; + struct ethhdr *eh; + int elem_cnt; + int nb_ack; + int ret; + + hdrlen = tcp_vu_l2_hdrlen(CONN_V6(conn)); + + vu_init_elem(elem, iov_vu, 2); + + elem_cnt = vu_collect_one_frame(vdev, vq, elem, 1, + hdrlen + OPT_MSS_LEN + OPT_WS_LEN + 1, + 0, NULL); + if (elem_cnt < 1) + return 0; + + vu_set_vnethdr(vdev, &iov_vu[0], 1, 0); + + eh = vu_eth(iov_vu[0].iov_base); + + memcpy(eh->h_dest, c->guest_mac, sizeof(eh->h_dest)); + memcpy(eh->h_source, c->our_tap_mac, sizeof(eh->h_source)); + + if (CONN_V4(conn)) { + struct tcp_payload_t *payload; + struct iphdr *iph; + uint32_t seq; + + eh->h_proto = htons(ETH_P_IP); + + iph = vu_ip(iov_vu[0].iov_base); + *iph = (struct iphdr)L2_BUF_IP4_INIT(IPPROTO_TCP); + + payload = vu_payloadv4(iov_vu[0].iov_base); + memset(&payload->th, 0, sizeof(payload->th)); + payload->th.doff = offsetof(struct tcp_flags_t, opts) / 4; + payload->th.ack = 1; + + seq = conn->seq_to_tap; + ret = tcp_prepare_flags(c, conn, flags, &payload->th, + (char *)payload->data, &optlen); + if (ret <= 0) { + vu_queue_rewind(vq, 1); + return ret; + } + + l4len = tcp_fill_headers4(conn, NULL, iph, payload, optlen, + NULL, seq, true); + l2len = sizeof(*iph); + } else { + struct tcp_payload_t *payload; + struct ipv6hdr *ip6h; + uint32_t seq; + + eh->h_proto = htons(ETH_P_IPV6); + + ip6h = vu_ip(iov_vu[0].iov_base); + *ip6h = (struct ipv6hdr)L2_BUF_IP6_INIT(IPPROTO_TCP); + + payload = vu_payloadv6(iov_vu[0].iov_base); + memset(&payload->th, 0, sizeof(payload->th)); + payload->th.doff = offsetof(struct tcp_flags_t, opts) / 4; + payload->th.ack = 1; + + seq = conn->seq_to_tap; + ret = tcp_prepare_flags(c, conn, flags, &payload->th, + (char *)payload->data, &optlen); + if (ret <= 0) { + vu_queue_rewind(vq, 1); + return ret; + } + + l4len = tcp_fill_headers6(conn, NULL, ip6h, payload, optlen, + seq, true); + l2len = sizeof(*ip6h); + } + l2len += l4len + sizeof(struct ethhdr); + + elem[0].in_sg[0].iov_len = l2len + + sizeof(struct virtio_net_hdr_mrg_rxbuf); + if (*c->pcap) { + tcp_vu_update_check(tapside, &elem[0].in_sg[0], 1); + pcap_iov(&elem[0].in_sg[0], 1, + sizeof(struct virtio_net_hdr_mrg_rxbuf)); + } + nb_ack = 1; + + if (flags & DUP_ACK) { + elem_cnt = vu_collect_one_frame(vdev, vq, &elem[1], 1, l2len, + 0, NULL); + if (elem_cnt == 1) { + memcpy(elem[1].in_sg[0].iov_base, + elem[0].in_sg[0].iov_base, l2len); + vu_set_vnethdr(vdev, &elem[1].in_sg[0], 1, 0); + nb_ack++; + + if (*c->pcap) + pcap_iov(&elem[1].in_sg[0], 1, 0); + } + } + + vu_flush(vdev, vq, elem, nb_ack); + + return 0; +} + +/** tcp_vu_sock_recv() - Receive datastream from socket into vhost-user buffers + * @c: Execution context + * @conn: Connection pointer + * @v4: Set for IPv4 connections + * @fillsize: Number of bytes we can receive + * @datalen: Size of received data (output) + * + * Return: Number of iov entries used to store the data, or negative error code+ */ +static ssize_t tcp_vu_sock_recv(const struct ctx *c, + struct tcp_tap_conn *conn, bool v4, + size_t fillsize, ssize_t *dlen) +{ + struct vu_dev *vdev = c->vdev; + struct vu_virtq *vq = &vdev->vq[VHOST_USER_RX_QUEUE]; + struct msghdr mh_sock = { 0 }; + uint16_t mss = MSS_GET(conn); + int s = conn->sock; + size_t l2_hdrlen; + int elem_cnt; + ssize_t ret; + + *dlen = 0; + + l2_hdrlen = tcp_vu_l2_hdrlen(!v4); + + vu_init_elem(elem, &iov_vu[1], VIRTQUEUE_MAX_SIZE); + + elem_cnt = vu_collect(vdev, vq, elem, VIRTQUEUE_MAX_SIZE, mss, + l2_hdrlen, fillsize); + if (elem_cnt < 0) { + tcp_rst(c, conn); + return -ENOMEM;On top of what David mentioned (I don't think this warrants a tcp_rst() either), ENOMEM means "out of memory", ENOBUFS (no buffer space available) is probably more appropriate here. We're not failing to allocate anything, it's just that there are no buffers left.+ } + + mh_sock.msg_iov = iov_vu; + mh_sock.msg_iovlen = elem_cnt + 1; + + do + ret = recvmsg(s, &mh_sock, MSG_PEEK); + while (ret < 0 && errno == EINTR); + + if (ret < 0) { + vu_queue_rewind(vq, elem_cnt); + if (errno != EAGAIN && errno != EWOULDBLOCK) { + ret = -errno; + tcp_rst(c, conn); + } + return ret; + } + if (!ret) { + vu_queue_rewind(vq, elem_cnt); + + if ((conn->events & (SOCK_FIN_RCVD | TAP_FIN_SENT)) == SOCK_FIN_RCVD) { + int retf = tcp_vu_send_flag(c, conn, FIN | ACK); + if (retf) { + tcp_rst(c, conn); + return retf; + } + + conn_event(c, conn, TAP_FIN_SENT); + } + return 0; + } + + *dlen = ret; + + return elem_cnt; +} + +/** + * tcp_vu_prepare() - Prepare the packet header + * @c: Execution context + * @conn: Connection pointer + * @first: Pointer to the array of IO vectors + * @dlen: Packet data length + * @check: Checksum, if already known + */ +static void tcp_vu_prepare(const struct ctx *c, + struct tcp_tap_conn *conn, struct iovec *first, + size_t dlen, const uint16_t **check) +{ + const struct flowside *toside = TAPFLOW(conn); + char *base = first->iov_base; + struct ethhdr *eh; + + /* we guess the first iovec provided by the guest can embed + * all the headers needed by L2 frame + */ + + eh = vu_eth(base); + + memcpy(eh->h_dest, c->guest_mac, sizeof(eh->h_dest)); + memcpy(eh->h_source, c->our_tap_mac, sizeof(eh->h_source)); + + /* initialize header */ + if (inany_v4(&toside->eaddr) && inany_v4(&toside->oaddr)) { + struct tcp_payload_t *payload; + struct iphdr *iph; + + ASSERT(first[0].iov_len >= sizeof(struct virtio_net_hdr_mrg_rxbuf) + + sizeof(struct ethhdr) + sizeof(struct iphdr) + + sizeof(struct tcphdr)); + + eh->h_proto = htons(ETH_P_IP); + + iph = vu_ip(base); + *iph = (struct iphdr)L2_BUF_IP4_INIT(IPPROTO_TCP); + payload = vu_payloadv4(base); + memset(&payload->th, 0, sizeof(payload->th)); + payload->th.doff = offsetof(struct tcp_payload_t, data) / 4; + payload->th.ack = 1; + + tcp_fill_headers4(conn, NULL, iph, payload, dlen, + *check, conn->seq_to_tap, true); + *check = &iph->check; + } else { + struct tcp_payload_t *payload; + struct ipv6hdr *ip6h; + + ASSERT(first[0].iov_len >= sizeof(struct virtio_net_hdr_mrg_rxbuf) + + sizeof(struct ethhdr) + sizeof(struct ipv6hdr) + + sizeof(struct tcphdr)); + + eh->h_proto = htons(ETH_P_IPV6); + + ip6h = vu_ip(base); + *ip6h = (struct ipv6hdr)L2_BUF_IP6_INIT(IPPROTO_TCP); + + payload = vu_payloadv6(base); + memset(&payload->th, 0, sizeof(payload->th)); + payload->th.doff = offsetof(struct tcp_payload_t, data) / 4; + payload->th.ack = 1; + + tcp_fill_headers6(conn, NULL, ip6h, payload, dlen, + conn->seq_to_tap, true); + } +} + +/** + * tcp_vu_data_from_sock() - Handle new data from socket, queue to vhost-user, + * in window + * @c: Execution context + * @conn: Connection pointer + * + * Return: Negative on connection reset, 0 otherwise + */ +int tcp_vu_data_from_sock(const struct ctx *c, struct tcp_tap_conn *conn) +{ + uint32_t wnd_scaled = conn->wnd_from_tap << conn->ws_from_tap; + struct vu_dev *vdev = c->vdev; + struct vu_virtq *vq = &vdev->vq[VHOST_USER_RX_QUEUE]; + const struct flowside *tapside = TAPFLOW(conn); + uint16_t mss = MSS_GET(conn); + size_t l2_hdrlen, fillsize; + int i, iov_cnt, iov_used; + int v4 = CONN_V4(conn); + uint32_t already_sent = 0; + const uint16_t *check; + struct iovec *first; + int frame_size; + int num_buffers; + ssize_t len; + + if (!vu_queue_enabled(vq) || !vu_queue_started(vq)) { + flow_err(conn, + "Got packet, but RX virtqueue not usable yet"); + return 0; + } + + already_sent = conn->seq_to_tap - conn->seq_ack_from_tap; + + if (SEQ_LT(already_sent, 0)) { + /* RFC 761, section 2.1. */ + flow_trace(conn, "ACK sequence gap: ACK for %u, sent: %u", + conn->seq_ack_from_tap, conn->seq_to_tap); + conn->seq_to_tap = conn->seq_ack_from_tap; + already_sent = 0; + } + + if (!wnd_scaled || already_sent >= wnd_scaled) { + conn_flag(c, conn, STALLED); + conn_flag(c, conn, ACK_FROM_TAP_DUE); + return 0; + } + + /* Set up buffer descriptors we'll fill completely and partially. */ + + fillsize = wnd_scaled; + + if (peek_offset_cap) + already_sent = 0; + + iov_vu[0].iov_base = tcp_buf_discard; + iov_vu[0].iov_len = already_sent;I think I had a similar comment to a previous revision. Now, I haven't tested this (yet) on a kernel with support for SO_PEEK_OFF on TCP, but I think this should eventually follow the same logic as the (updated) tcp_buf_data_from_sock(): we should use tcp_buf_discard only if (!peek_offset_cap). It's fine to always initialise VIRTQUEUE_MAX_SIZE iov_vu items, starting from 1, for simplicity. But I'm not sure if it's safe to pass a zero iov_len if (peek_offset_cap). I'll test that (unless you already did) -- if it works, we can fix this up later as well.+ fillsize -= already_sent; + + /* collect the buffers from vhost-user and fill them with the + * data from the socket + */ + iov_cnt = tcp_vu_sock_recv(c, conn, v4, fillsize, &len); + if (iov_cnt <= 0) + return iov_cnt; + + len -= already_sent; + if (len <= 0) { + conn_flag(c, conn, STALLED); + vu_queue_rewind(vq, iov_cnt); + return 0; + } + + conn_flag(c, conn, ~STALLED); + + /* Likely, some new data was acked too. */ + tcp_update_seqack_wnd(c, conn, 0, NULL); + + /* initialize headers */ + l2_hdrlen = tcp_vu_l2_hdrlen(!v4); + iov_used = 0; + num_buffers = 0; + check = NULL; + frame_size = 0; + + /* iov_vu is an array of buffers and the buffer size can be + * smaller than the frame size we want to use but with + * num_buffer we can merge several virtio iov buffers in one packet + * we need only to set the packet headers in the first iov and + * num_buffer to the number of iov entries + */ + for (i = 0; i < iov_cnt && len; i++) { + + if (frame_size == 0) + first = &iov_vu[i + 1]; + + if (iov_vu[i + 1].iov_len > (size_t)len) + iov_vu[i + 1].iov_len = len; + + len -= iov_vu[i + 1].iov_len; + iov_used++; + + frame_size += iov_vu[i + 1].iov_len; + num_buffers++; + + if (frame_size >= mss || len == 0 || + i + 1 == iov_cnt || !vu_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) { + if (i + 1 == iov_cnt) + check = NULL; + + /* restore first iovec base: point to vnet header */ + vu_set_vnethdr(vdev, first, num_buffers, l2_hdrlen); + + tcp_vu_prepare(c, conn, first, frame_size, &check); + if (*c->pcap) {Nit: excess whitespace.+ tcp_vu_update_check(tapside, first, num_buffers); + pcap_iov(first, num_buffers, + sizeof(struct virtio_net_hdr_mrg_rxbuf)); + } + + conn->seq_to_tap += frame_size; + + frame_size = 0; + num_buffers = 0; + } + } + + /* release unused buffers */ + vu_queue_rewind(vq, iov_cnt - iov_used); + + /* send packets */ + vu_flush(vdev, vq, elem, iov_used); + + conn_flag(c, conn, ACK_FROM_TAP_DUE); + + return 0; +}Minus those and David's comments, it looks good to me until this point -- I'm still reviewing the UDP part and the common_vu.c functions. -- Stefano