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[Qemu-devel] [PATCH 1/4] Unified Datagram Socket Transports
|
From: |
anton . ivanov |
|
Subject: |
[Qemu-devel] [PATCH 1/4] Unified Datagram Socket Transports |
|
Date: |
Wed, 19 Jul 2017 21:02:56 +0100 |
From: Anton Ivanov <address@hidden>
Basic infrastructure to start moving datagram based transports
to a common infrastructure as well as introduce several
additional transports.
Signed-off-by: Anton Ivanov <address@hidden>
---
configure | 12 +-
net/Makefile.objs | 2 +-
net/net.c | 4 +-
net/udst.c | 420 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
net/udst.h | 121 ++++++++++++++++
qapi-schema.json | 19 ++-
qemu-options.hx | 2 +-
7 files changed, 569 insertions(+), 11 deletions(-)
create mode 100644 net/udst.c
create mode 100644 net/udst.h
diff --git a/configure b/configure
index bad50f5368..00c911c49b 100755
--- a/configure
+++ b/configure
@@ -1862,7 +1862,9 @@ if ! compile_object -Werror ; then
fi
##########################################
-# L2TPV3 probe
+# UDST probe
+# identical to L2TPv3 probe used for both
+# during migration of L2TPv3 to udst backend
cat > $TMPC <<EOF
#include <sys/socket.h>
@@ -1870,9 +1872,9 @@ cat > $TMPC <<EOF
int main(void) { return sizeof(struct mmsghdr); }
EOF
if compile_prog "" "" ; then
- l2tpv3=yes
+ udst=yes
else
- l2tpv3=no
+ udst=no
fi
##########################################
@@ -5491,8 +5493,8 @@ fi
if test "$netmap" = "yes" ; then
echo "CONFIG_NETMAP=y" >> $config_host_mak
fi
-if test "$l2tpv3" = "yes" ; then
- echo "CONFIG_L2TPV3=y" >> $config_host_mak
+if test "$udst" = "yes" ; then
+ echo "CONFIG_UDST=y" >> $config_host_mak
fi
if test "$cap_ng" = "yes" ; then
echo "CONFIG_LIBCAP=y" >> $config_host_mak
diff --git a/net/Makefile.objs b/net/Makefile.objs
index 67ba5e26fb..ffdfb96bd0 100644
--- a/net/Makefile.objs
+++ b/net/Makefile.objs
@@ -2,7 +2,7 @@ common-obj-y = net.o queue.o checksum.o util.o hub.o
common-obj-y += socket.o
common-obj-y += dump.o
common-obj-y += eth.o
-common-obj-$(CONFIG_L2TPV3) += l2tpv3.o
+common-obj-$(CONFIG_UDST) += udst.o l2tpv3.o
common-obj-$(CONFIG_POSIX) += vhost-user.o
common-obj-$(CONFIG_SLIRP) += slirp.o
common-obj-$(CONFIG_VDE) += vde.o
diff --git a/net/net.c b/net/net.c
index 0e28099554..723a256260 100644
--- a/net/net.c
+++ b/net/net.c
@@ -960,8 +960,8 @@ static int (* const
net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
#ifdef CONFIG_VHOST_NET_USED
[NET_CLIENT_DRIVER_VHOST_USER] = net_init_vhost_user,
#endif
-#ifdef CONFIG_L2TPV3
- [NET_CLIENT_DRIVER_L2TPV3] = net_init_l2tpv3,
+#ifdef CONFIG_UDST
+ [NET_CLIENT_DRIVER_L2TPV3] = net_init_l2tpv3,
#endif
};
diff --git a/net/udst.c b/net/udst.c
new file mode 100644
index 0000000000..612c90cb3a
--- /dev/null
+++ b/net/udst.c
@@ -0,0 +1,420 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2015-2017 Cambridge Greys Limited
+ * Copyright (c) 2012-2014 Cisco Systems
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/*
+ * Udst Datagram Socket Transport Backend
+ * This transport is not intended to be initiated directly by an end-user
+ * It is used as a backend for other transports which use recv/sendmmsg
+ * socket functions for RX/TX.
+ */
+
+#include "qemu/osdep.h"
+#include <linux/ip.h>
+#include <netdb.h>
+#include "net/net.h"
+#include "clients.h"
+#include "qemu-common.h"
+#include "qemu/error-report.h"
+#include "qemu/option.h"
+#include "qemu/sockets.h"
+#include "qemu/iov.h"
+#include "qemu/main-loop.h"
+#include "udst.h"
+
+static void net_udst_send(void *opaque);
+static void udst_writable(void *opaque);
+
+static void udst_update_fd_handler(NetUdstState *s)
+{
+ qemu_set_fd_handler(s->fd,
+ s->read_poll ? net_udst_send : NULL,
+ s->write_poll ? udst_writable : NULL,
+ s);
+}
+
+static void udst_read_poll(NetUdstState *s, bool enable)
+{
+ if (s->read_poll != enable) {
+ s->read_poll = enable;
+ udst_update_fd_handler(s);
+ }
+}
+
+static void udst_write_poll(NetUdstState *s, bool enable)
+{
+ if (s->write_poll != enable) {
+ s->write_poll = enable;
+ udst_update_fd_handler(s);
+ }
+}
+
+static void udst_writable(void *opaque)
+{
+ NetUdstState *s = opaque;
+ udst_write_poll(s, false);
+ qemu_flush_queued_packets(&s->nc);
+}
+
+static void udst_send_completed(NetClientState *nc, ssize_t len)
+{
+ NetUdstState *s = DO_UPCAST(NetUdstState, nc, nc);
+ udst_read_poll(s, true);
+}
+
+static void udst_poll(NetClientState *nc, bool enable)
+{
+ NetUdstState *s = DO_UPCAST(NetUdstState, nc, nc);
+ udst_write_poll(s, enable);
+ udst_read_poll(s, enable);
+}
+
+static ssize_t net_udst_receive_dgram_iov(NetClientState *nc,
+ const struct iovec *iov,
+ int iovcnt)
+{
+ NetUdstState *s = DO_UPCAST(NetUdstState, nc, nc);
+
+ struct msghdr message;
+ int ret;
+
+ if (iovcnt > MAX_UNIFIED_IOVCNT - 1) {
+ error_report(
+ "iovec too long %d > %d, change udst.h",
+ iovcnt, MAX_UNIFIED_IOVCNT
+ );
+ return -1;
+ }
+ if (s->offset > 0) {
+ s->form_header(s);
+ memcpy(s->vec + 1, iov, iovcnt * sizeof(struct iovec));
+ s->vec->iov_base = s->header_buf;
+ s->vec->iov_len = s->offset;
+ message.msg_iovlen = iovcnt + 1;
+ } else {
+ memcpy(s->vec, iov, iovcnt * sizeof(struct iovec));
+ message.msg_iovlen = iovcnt;
+ }
+ message.msg_name = s->dgram_dst;
+ message.msg_namelen = s->dst_size;
+ message.msg_iov = s->vec;
+ message.msg_control = NULL;
+ message.msg_controllen = 0;
+ message.msg_flags = 0;
+ do {
+ ret = sendmsg(s->fd, &message, 0);
+ } while ((ret == -1) && (errno == EINTR));
+ if (ret > 0) {
+ ret -= s->offset;
+ } else if (ret == 0) {
+ /* belt and braces - should not occur on DGRAM
+ * we should get an error and never a 0 send
+ */
+ ret = iov_size(iov, iovcnt);
+ } else {
+ /* signal upper layer that socket buffer is full */
+ ret = -errno;
+ if (ret == -EAGAIN || ret == -ENOBUFS) {
+ udst_write_poll(s, true);
+ ret = 0;
+ }
+ }
+ return ret;
+}
+
+static ssize_t net_udst_receive_dgram(NetClientState *nc,
+ const uint8_t *buf,
+ size_t size)
+{
+ NetUdstState *s = DO_UPCAST(NetUdstState, nc, nc);
+
+ struct iovec *vec;
+ struct msghdr message;
+ ssize_t ret = 0;
+
+ vec = s->vec;
+ if (s->offset > 0) {
+ s->form_header(s);
+ vec->iov_base = s->header_buf;
+ vec->iov_len = s->offset;
+ message.msg_iovlen = 2;
+ vec++;
+ } else {
+ message.msg_iovlen = 1;
+ }
+ vec->iov_base = (void *) buf;
+ vec->iov_len = size;
+ message.msg_name = s->dgram_dst;
+ message.msg_namelen = s->dst_size;
+ message.msg_iov = s->vec;
+ message.msg_control = NULL;
+ message.msg_controllen = 0;
+ message.msg_flags = 0;
+ do {
+ ret = sendmsg(s->fd, &message, 0);
+ } while ((ret == -1) && (errno == EINTR));
+ if (ret > 0) {
+ ret -= s->offset;
+ } else if (ret == 0) {
+ /* belt and braces - should not occur on DGRAM
+ * we should get an error and never a 0 send
+ */
+ ret = size;
+ } else {
+ ret = -errno;
+ if (ret == -EAGAIN || ret == -ENOBUFS) {
+ /* signal upper layer that socket buffer is full */
+ udst_write_poll(s, true);
+ ret = 0;
+ }
+ }
+ return ret;
+}
+
+
+static void net_udst_process_queue(NetUdstState *s)
+{
+ int size = 0;
+ struct iovec *vec;
+ bool bad_read;
+ int data_size;
+ struct mmsghdr *msgvec;
+
+ /* go into ring mode only if there is a "pending" tail */
+ if (s->queue_depth > 0) {
+ do {
+ msgvec = s->msgvec + s->queue_tail;
+ if (msgvec->msg_len > 0) {
+ data_size = msgvec->msg_len - s->header_size;
+ vec = msgvec->msg_hdr.msg_iov;
+ if ((data_size > 0) &&
+ (s->verify_header(s, vec->iov_base) == 0)) {
+ if (s->header_size > 0) {
+ vec++;
+ }
+ /* Use the legacy delivery for now, we will
+ * switch to using our own ring as a queueing mechanism
+ * at a later date
+ */
+ size = qemu_send_packet_async(
+ &s->nc,
+ vec->iov_base,
+ data_size,
+ udst_send_completed
+ );
+ if (size == 0) {
+ udst_read_poll(s, false);
+ }
+ bad_read = false;
+ } else {
+ bad_read = true;
+ if (!s->header_mismatch) {
+ /* report error only once */
+ error_report("udst header verification failed");
+ s->header_mismatch = true;
+ }
+ }
+ } else {
+ bad_read = true;
+ }
+ s->queue_tail = (s->queue_tail + 1) % MAX_UNIFIED_MSGCNT;
+ s->queue_depth--;
+ } while (
+ (s->queue_depth > 0) &&
+ qemu_can_send_packet(&s->nc) &&
+ ((size > 0) || bad_read)
+ );
+ }
+}
+
+static void net_udst_send(void *opaque)
+{
+ NetUdstState *s = opaque;
+ int target_count, count;
+ struct mmsghdr *msgvec;
+
+ /* go into ring mode only if there is a "pending" tail */
+
+ if (s->queue_depth) {
+
+ /* The ring buffer we use has variable intake
+ * count of how much we can read varies - adjust accordingly
+ */
+
+ target_count = MAX_UNIFIED_MSGCNT - s->queue_depth;
+
+ /* Ensure we do not overrun the ring when we have
+ * a lot of enqueued packets
+ */
+
+ if (s->queue_head + target_count > MAX_UNIFIED_MSGCNT) {
+ target_count = MAX_UNIFIED_MSGCNT - s->queue_head;
+ }
+ } else {
+
+ /* we do not have any pending packets - we can use
+ * the whole message vector linearly instead of using
+ * it as a ring
+ */
+
+ s->queue_head = 0;
+ s->queue_tail = 0;
+ target_count = MAX_UNIFIED_MSGCNT;
+ }
+
+ msgvec = s->msgvec + s->queue_head;
+ if (target_count > 0) {
+ do {
+ count = recvmmsg(
+ s->fd,
+ msgvec,
+ target_count, MSG_DONTWAIT, NULL);
+ } while ((count == -1) && (errno == EINTR));
+ if (count < 0) {
+ /* Recv error - we still need to flush packets here,
+ * (re)set queue head to current position
+ */
+ count = 0;
+ }
+ s->queue_head = (s->queue_head + count) % MAX_UNIFIED_MSGCNT;
+ s->queue_depth += count;
+ }
+ net_udst_process_queue(s);
+}
+
+static void destroy_vector(struct mmsghdr *msgvec, int count, int iovcount)
+{
+ int i, j;
+ struct iovec *iov;
+ struct mmsghdr *cleanup = msgvec;
+ if (cleanup) {
+ for (i = 0; i < count; i++) {
+ if (cleanup->msg_hdr.msg_iov) {
+ iov = cleanup->msg_hdr.msg_iov;
+ for (j = 0; j < iovcount; j++) {
+ g_free(iov->iov_base);
+ iov++;
+ }
+ g_free(cleanup->msg_hdr.msg_iov);
+ }
+ cleanup++;
+ }
+ g_free(msgvec);
+ }
+}
+
+
+
+static struct mmsghdr *build_udst_vector(NetUdstState *s, int count)
+{
+ int i;
+ struct iovec *iov;
+ struct mmsghdr *msgvec, *result;
+
+ msgvec = g_new(struct mmsghdr, count);
+ result = msgvec;
+ for (i = 0; i < count ; i++) {
+ msgvec->msg_hdr.msg_name = NULL;
+ msgvec->msg_hdr.msg_namelen = 0;
+ iov = g_new(struct iovec, IOVSIZE);
+ msgvec->msg_hdr.msg_iov = iov;
+ if (s->header_size > 0) {
+ iov->iov_base = g_malloc(s->header_size);
+ iov->iov_len = s->header_size;
+ iov++ ;
+ }
+ iov->iov_base = qemu_memalign(BUFFER_ALIGN, BUFFER_SIZE);
+ iov->iov_len = BUFFER_SIZE;
+ msgvec->msg_hdr.msg_iovlen = 2;
+ msgvec->msg_hdr.msg_control = NULL;
+ msgvec->msg_hdr.msg_controllen = 0;
+ msgvec->msg_hdr.msg_flags = 0;
+ msgvec++;
+ }
+ return result;
+}
+
+static void net_udst_cleanup(NetClientState *nc)
+{
+ NetUdstState *s = DO_UPCAST(NetUdstState, nc, nc);
+ qemu_purge_queued_packets(nc);
+ udst_read_poll(s, false);
+ udst_write_poll(s, false);
+ if (s->fd >= 0) {
+ close(s->fd);
+ }
+ if (s->header_size > 0) {
+ destroy_vector(s->msgvec, MAX_UNIFIED_MSGCNT, IOVSIZE);
+ } else {
+ destroy_vector(s->msgvec, MAX_UNIFIED_MSGCNT, 1);
+ }
+ g_free(s->vec);
+ if (s->header_buf != NULL) {
+ g_free(s->header_buf);
+ }
+ if (s->dgram_dst != NULL) {
+ g_free(s->dgram_dst);
+ }
+}
+
+static NetClientInfo net_udst_info = {
+ /* we share this one for all types for now, wrong I know :) */
+ .type = NET_CLIENT_DRIVER_UDST,
+ .size = sizeof(NetUdstState),
+ .receive = net_udst_receive_dgram,
+ .receive_iov = net_udst_receive_dgram_iov,
+ .poll = udst_poll,
+ .cleanup = net_udst_cleanup,
+};
+
+NetClientState *qemu_new_udst_net_client(const char *name,
+ NetClientState *peer) {
+ return qemu_new_net_client(&net_udst_info, peer, "udst", name);
+}
+
+void qemu_net_finalize_udst_init(NetUdstState *s,
+ int (*verify_header)(void *s, uint8_t *buf),
+ void (*form_header)(void *s),
+ int fd)
+{
+
+ s->form_header = form_header;
+ s->verify_header = verify_header;
+ s->queue_head = 0;
+ s->queue_tail = 0;
+ s->header_mismatch = false;
+ s->msgvec = build_udst_vector(s, MAX_UNIFIED_MSGCNT);
+ s->vec = g_new(struct iovec, MAX_UNIFIED_IOVCNT);
+ if (s->header_size > 0) {
+ s->header_buf = g_malloc(s->header_size);
+ } else {
+ s->header_buf = NULL;
+ }
+ qemu_set_nonblock(fd);
+
+ s->fd = fd;
+ udst_read_poll(s, true);
+
+}
diff --git a/net/udst.h b/net/udst.h
new file mode 100644
index 0000000000..2a6b44c74d
--- /dev/null
+++ b/net/udst.h
@@ -0,0 +1,121 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2015-2017 Cambridge Greys Limited
+ * Copyright (c) 2012-2014 Cisco Systems
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+
+
+#define BUFFER_ALIGN sysconf(_SC_PAGESIZE)
+#define BUFFER_SIZE 2048
+#define IOVSIZE 2
+#define MAX_UNIFIED_MSGCNT 64
+#define MAX_UNIFIED_IOVCNT (MAX_UNIFIED_MSGCNT * IOVSIZE)
+
+#ifndef QEMU_NET_UNIFIED_H
+#define QEMU_NET_UNIFIED_H
+
+typedef struct NetUdstState {
+ NetClientState nc;
+
+ int fd;
+
+ /*
+ * these are used for xmit - that happens packet a time
+ * and for first sign of life packet (easier to parse that once)
+ */
+
+ uint8_t *header_buf;
+ struct iovec *vec;
+
+ /*
+ * these are used for receive - try to "eat" up to 32 packets at a time
+ */
+
+ struct mmsghdr *msgvec;
+
+ /*
+ * peer address
+ */
+
+ struct sockaddr_storage *dgram_dst;
+ uint32_t dst_size;
+
+ /*
+ * Internal Queue
+ */
+
+ /*
+ * DOS avoidance in error handling
+ */
+
+ /* Easier to keep l2tpv3 specific */
+
+ bool header_mismatch;
+
+ /*
+ *
+ * Ring buffer handling
+ *
+ */
+
+ int queue_head;
+ int queue_tail;
+ int queue_depth;
+
+ /*
+ * Offset to data - common for all protocols
+ */
+
+ uint32_t offset;
+
+ /*
+ * Header size - common for all protocols
+ */
+
+ uint32_t header_size;
+ /* Poll Control */
+
+ bool read_poll;
+ bool write_poll;
+
+ /* Parameters */
+
+ void *params;
+
+ /* header forming functions */
+
+ int (*verify_header)(void *s, uint8_t *buf);
+ void (*form_header)(void *s);
+
+} NetUdstState;
+
+extern NetClientState *qemu_new_udst_net_client(const char *name,
+ NetClientState *peer);
+
+extern void qemu_net_finalize_udst_init(NetUdstState *s,
+ int (*verify_header)(void *s, uint8_t *buf),
+ void (*form_header)(void *s),
+ int fd);
+#endif
diff --git a/qapi-schema.json b/qapi-schema.json
index 8b015bee2e..62a044f006 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -3854,6 +3854,18 @@
'*offset': 'uint32' } }
##
+# @NetdevUdstOptions:
+#
+# Common Datagram backend for unified datagram
+# socket transports
+# Should not be instantiated directly
+
+# Since: 2.11
+##
+{ 'struct': 'NetdevUdstOptions',
+ 'data': { } }
+
+##
# @NetdevVdeOptions:
#
# Connect the VLAN to a vde switch running on the host.
@@ -3971,7 +3983,7 @@
##
{ 'enum': 'NetClientDriver',
'data': [ 'none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'vde', 'dump',
- 'bridge', 'hubport', 'netmap', 'vhost-user' ] }
+ 'bridge', 'hubport', 'netmap', 'vhost-user', 'udst' ] }
##
# @Netdev:
@@ -3985,6 +3997,8 @@
# Since: 1.2
#
# 'l2tpv3' - since 2.1
+#
+# 'udst' - since 2.11
##
{ 'union': 'Netdev',
'base': { 'id': 'str', 'type': 'NetClientDriver' },
@@ -4001,7 +4015,8 @@
'bridge': 'NetdevBridgeOptions',
'hubport': 'NetdevHubPortOptions',
'netmap': 'NetdevNetmapOptions',
- 'vhost-user': 'NetdevVhostUserOptions' } }
+ 'vhost-user': 'NetdevVhostUserOptions',
+ 'udst': 'NetdevUdstOptions' } }
##
# @NetLegacy:
diff --git a/qemu-options.hx b/qemu-options.hx
index 746b5fa75d..9caf53fd76 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1945,7 +1945,7 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
" connected to a bridge (default=" DEFAULT_BRIDGE_INTERFACE
")\n"
" using the program 'helper (default="
DEFAULT_BRIDGE_HELPER ")\n"
#endif
-#ifdef __linux__
+#ifdef CONFIG_UDST
"-netdev
l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
"
[,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
" [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
--
2.11.0