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-rw-r--r--src/kernel/net.c528
1 files changed, 528 insertions, 0 deletions
diff --git a/src/kernel/net.c b/src/kernel/net.c
new file mode 100644
index 0000000..f44925f
--- /dev/null
+++ b/src/kernel/net.c
@@ -0,0 +1,528 @@
+/*
+ * This file is part of the Distributed Network Block Device 3
+ *
+ * Copyright(c) 2019 Frederic Robra <frederic@robra.org>
+ * Parts copyright 2011-2012 Johann Latocha <johann@latocha.de>
+ *
+ * This file may be licensed under the terms of of the
+ * GNU General Public License Version 2 (the ``GPL'').
+ *
+ * Software distributed under the License is distributed
+ * on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either
+ * express or implied. See the GPL for the specific language
+ * governing rights and limitations.
+ *
+ * You should have received a copy of the GPL along with this
+ * program. If not, go to http://www.gnu.org/licenses/gpl.html
+ * or write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+
+
+#include <net/sock.h>
+
+#include "dnbd3.h"
+#include "clientconfig.h"
+
+#define dnbd3_cmd_to_priv(req, cmd) (req)->cmd_flags = REQ_OP_DRV_IN | ((cmd) << REQ_FLAG_BITS)
+#define dnbd3_priv_to_cmd(req) ((req)->cmd_flags >> REQ_FLAG_BITS)
+#define dnbd3_req_op(req) req_op(req)
+#define dnbd3_sock_create(af,type,proto,sock) sock_create_kern(&init_net, (af) == HOST_IP4 ? AF_INET : AF_INET6, type, proto, sock)
+
+#define KEEPALIVE_TIMER (TIMER_INTERVAL_KEEPALIVE_PACKET * (jiffies + HZ))
+#define DISCOVERY_TIMER (TIMER_INTERVAL_PROBE_NORMAL * (jiffies + HZ))
+
+#define init_msghdr(h) do { \
+ h.msg_name = NULL; \
+ h.msg_namelen = 0; \
+ h.msg_control = NULL; \
+ h.msg_controllen = 0; \
+ h.msg_flags = MSG_WAITALL | MSG_NOSIGNAL; \
+ } while (0)
+
+
+static void printHost(struct dnbd3_host_t *host, char *msg)
+{
+ if (host->type == HOST_IP4) {
+ printk(KERN_INFO "dnbd3: %s %pI4:%d\n", msg, host->addr, host->port);
+ } else {
+ printk(KERN_INFO "dnbd3: %s [%pI6]:%d\n", msg, host->addr, host->port);
+ }
+}
+
+static void printServerList(struct dnbd3_device *dev)
+{
+ int i;
+ printHost(&dev->initial_server.host, "initial server is");
+ for (i = 0; i < NUMBER_SERVERS; i++) {
+ if (dev->alt_servers[i].host.addr[0] != 0) {
+ printHost(&dev->alt_servers[i].host, "alternative server is");
+ }
+ }
+}
+
+int dnbd3_send_request(struct dnbd3_device *dev, struct dnbd3_sock *sock, struct request *req)
+{
+ dnbd3_request_t dnbd3_request;
+ dnbd3_reply_t dnbd3_reply;
+ struct msghdr msg;
+ struct kvec iov;
+ struct req_iterator iter;
+ struct bio_vec bvec_inst;
+ struct bio_vec *bvec = &bvec_inst;
+ sigset_t blocked, oldset;
+ void *kaddr;
+ int result, count, remaining;
+ uint16_t rid;
+ sock->pending = req;
+ init_msghdr(msg);
+
+ dnbd3_request.magic = dnbd3_packet_magic;
+
+ switch (req_op(req)) {
+// case REQ_OP_DISCARD:
+// printk(KERN_DEBUG "dnbd3: request operation discard on device %d\n", dev->minor);
+// break;
+// case REQ_OP_FLUSH:
+// printk(KERN_DEBUG "dnbd3: request operation flush on device %d\n", dev->minor);
+// break;
+// case REQ_OP_WRITE:
+// printk(KERN_DEBUG "dnbd3: request operation write on device %d\n", dev->minor);
+// break;
+ case REQ_OP_READ:
+ printk(KERN_DEBUG "dnbd3: request operation read\n");
+ dnbd3_request.cmd = CMD_GET_BLOCK;
+ dnbd3_request.offset = blk_rq_pos(req) << 9; // *512
+ dnbd3_request.size = blk_rq_bytes(req); // bytes left to complete entire request
+ break;
+ case REQ_OP_DRV_IN:
+ printk(KERN_DEBUG "dnbd3: request operation driver in\n");
+ dnbd3_request.cmd = dnbd3_priv_to_cmd(req);
+ dnbd3_request.size = 0;
+ break;
+
+ default:
+ return -EIO;
+ }
+
+ dnbd3_request.handle = (uint64_t)(uintptr_t)req; // Double cast to prevent warning on 32bit
+ fixup_request(dnbd3_request);
+ iov.iov_base = &dnbd3_request;
+ iov.iov_len = sizeof(dnbd3_request);
+ if (kernel_sendmsg(sock->sock, &msg, &iov, 1, sizeof(dnbd3_request)) != sizeof(dnbd3_request)) {
+ printk(KERN_ERR "dnbd3: connection to server lost\n");
+ result = -EIO;
+ goto error;
+ }
+
+ // receive net reply
+ iov.iov_base = &dnbd3_reply;
+ iov.iov_len = sizeof(dnbd3_reply);
+ result = kernel_recvmsg(sock->sock, &msg, &iov, 1, sizeof(dnbd3_reply), msg.msg_flags);
+ if (!result) {
+ printk(KERN_ERR "dnbd3: connection to server lost\n");
+ result = -EIO;
+ goto error;
+
+ }
+ fixup_reply(dnbd3_reply);
+
+ // check error
+ if (dnbd3_reply.magic != dnbd3_packet_magic) {
+ printk(KERN_ERR "dnbd3: wrong magic packet\n");
+ result = -EIO;
+ goto error;
+ }
+
+ if (dnbd3_reply.cmd == 0) {
+ printk(KERN_ERR "dnbd3: command was 0\n");
+ result = -EIO;
+ goto error;
+ }
+
+
+ switch (dnbd3_reply.cmd) {
+ case CMD_GET_BLOCK:
+ rq_for_each_segment(bvec_inst, req, iter) {
+ siginitsetinv(&blocked, sigmask(SIGKILL));
+ sigprocmask(SIG_SETMASK, &blocked, &oldset);
+
+ kaddr = kmap(bvec->bv_page) + bvec->bv_offset;
+ iov.iov_base = kaddr;
+ iov.iov_len = bvec->bv_len;
+ if (kernel_recvmsg(sock->sock, &msg, &iov, 1, bvec->bv_len, msg.msg_flags) != bvec->bv_len) {
+ kunmap(bvec->bv_page);
+ sigprocmask(SIG_SETMASK, &oldset, NULL );
+ printk(KERN_ERR "dnbd3: could not receive form net to block layer\n");
+ goto error;
+ }
+ kunmap(bvec->bv_page);
+
+ sigprocmask(SIG_SETMASK, &oldset, NULL );
+ }
+ blk_mq_end_request(req, 0);
+ break;
+ case CMD_GET_SERVERS:
+ printk(KERN_DEBUG "dnbd3: get servers received\n");
+ mutex_lock(&dev->device_lock);
+ if (!dev->use_server_provided_alts) {
+ remaining = dnbd3_reply.size;
+ goto consume_payload;
+ }
+ dev->new_servers_num = 0;
+ count = MIN(NUMBER_SERVERS, dnbd3_reply.size / sizeof(dnbd3_server_entry_t));
+
+ if (count != 0) {
+ iov.iov_base = dev->new_servers;
+ iov.iov_len = count * sizeof(dnbd3_server_entry_t);
+ if (kernel_recvmsg(sock->sock, &msg, &iov, 1, (count * sizeof(dnbd3_server_entry_t)), msg.msg_flags) != (count * sizeof(dnbd3_server_entry_t))) {
+ printk(KERN_ERR "dnbd3: failed to get servers\n");
+ mutex_unlock(&dev->device_lock);
+ goto error;
+ }
+ dev->new_servers_num = count;
+ }
+ // If there were more servers than accepted, remove the remaining data from the socket buffer
+ remaining = dnbd3_reply.size - (count * sizeof(dnbd3_server_entry_t));
+consume_payload:
+ while (remaining > 0) {
+ count = MIN(sizeof(dnbd3_reply), remaining); // Abuse the reply struct as the receive buffer
+ iov.iov_base = &dnbd3_reply;
+ iov.iov_len = count;
+ result = kernel_recvmsg(sock->sock, &msg, &iov, 1, iov.iov_len, msg.msg_flags);
+ if (result <= 0) {
+ printk(KERN_ERR "dnbd3: failed to receive payload from get servers\n");
+ mutex_unlock(&dev->device_lock);
+ goto error;
+ }
+ result = 0;
+ }
+ mutex_unlock(&dev->device_lock);
+ break;
+ case CMD_LATEST_RID:
+ if (dnbd3_reply.size != 2) {
+ printk(KERN_ERR "dnbd3: failed to get latest rid, wrong size\n");
+ goto error;
+ }
+ printk(KERN_DEBUG "dnbd3: latest rid received\n");
+ iov.iov_base = &rid;
+ iov.iov_len = sizeof(rid);
+ if (kernel_recvmsg(sock->sock, &msg, &iov, 1, iov.iov_len, msg.msg_flags) <= 0) {
+ printk(KERN_ERR "dnbd3: failed to get latest rid\n");
+ goto error;
+ }
+ rid = net_order_16(rid);
+ printk("Latest rid of %s is %d (currently using %d)\n", dev->imgname, (int)rid, (int)dev->rid);
+ dev->update_available = (rid > dev->rid ? 1 : 0);
+ break;
+ case CMD_KEEPALIVE:
+ if (dnbd3_reply.size != 0) {
+ printk(KERN_ERR "dnbd3: got keep alive packet with payload\n");
+ goto error;
+ }
+ printk(KERN_DEBUG "dnbd3: keep alive received\n");
+ break;
+
+ default:
+ printk("ERROR: Unknown command (Receive)\n");
+ break;
+
+ }
+ sock->pending = NULL;
+error:
+ return result;
+}
+
+
+void dnbd3_keepalive(struct timer_list *arg)
+{
+ struct dnbd3_sock *sock = container_of(arg, struct dnbd3_sock, keepalive_timer);
+ printk(KERN_DEBUG "dnbd3: schedule keepalive\n");
+// schedule_work(&sock->keepalive);
+ sock->keepalive_timer.expires = KEEPALIVE_TIMER;
+ add_timer(&sock->keepalive_timer);
+}
+
+static void keepalive(struct work_struct *work)
+{
+ struct dnbd3_sock *sock = container_of(work, struct dnbd3_sock, keepalive);
+ struct request *req;
+ mutex_lock(&sock->lock);
+ req = kmalloc(sizeof(struct request), GFP_ATOMIC );
+ // send keepalive
+ if (req) {
+ dnbd3_cmd_to_priv(req, CMD_KEEPALIVE);
+ dnbd3_send_request(NULL, sock, req); // we do not need the device for keepalive
+ kfree(req);
+ } else {
+ printk(KERN_WARNING "dnbd3: could not create keepalive request\n");
+ }
+ ++sock->heartbeat_count;
+ mutex_unlock(&sock->lock);
+}
+
+void dnbd3_discovery(struct timer_list *arg)
+{
+ struct dnbd3_device *dev = container_of(arg, struct dnbd3_device, discovery_timer);
+ printk(KERN_DEBUG "dnbd3: schedule discovery\n");
+// schedule_work(&dev->discovery);
+ dev->discovery_timer.expires = DISCOVERY_TIMER;
+ add_timer(&dev->discovery_timer);
+}
+
+static void discovery(struct work_struct *work)
+{
+ struct dnbd3_device *dev = container_of(work, struct dnbd3_device, discovery);
+ dnbd3_sock *sock = &dev->socks[0]; // we use the first sock for discovery
+ struct request *req;
+ mutex_lock(&sock->lock);
+ req = kmalloc(sizeof(struct request), GFP_ATOMIC );
+ // send keepalive
+ if (req) {
+ dnbd3_cmd_to_priv(req, CMD_GET_SERVERS);
+ dnbd3_send_request(NULL, sock, req); // we do not need the device for keepalive
+ kfree(req);
+ } else {
+ printk(KERN_WARNING "dnbd3: could not create get servers request\n");
+ }
+ mutex_unlock(&sock->lock);
+}
+
+
+static int dnbd3_socket_connect(dnbd3_device *dev, dnbd3_sock *sock)
+{
+ int result = -EIO;
+ struct request *req1 = NULL;
+ struct timeval timeout;
+ struct dnbd3_server *server = sock->server;
+ dnbd3_request_t dnbd3_request;
+ dnbd3_reply_t dnbd3_reply;
+ struct msghdr msg;
+ struct kvec iov[2];
+ uint16_t rid;
+ uint64_t reported_size;
+ char *name;
+ int mlen;
+ serialized_buffer_t payload_buffer;
+
+ printk(KERN_DEBUG "dnbd3: socket connect device %i\n", dev->minor);
+
+ mutex_init(&sock->lock);
+ mutex_lock(&sock->lock);
+ if (sock->pending) {
+ printk(KERN_DEBUG "dnbd3: socket still in request\n");
+ while (sock->pending)
+ schedule();
+ }
+ if (server->host.port == 0 || server->host.type == 0) {
+ printk(KERN_ERR "dnbd3: host or port not set\n");
+ goto error;
+ }
+ if (sock->sock) {
+ printk(KERN_WARNING "dnbd3: socket already connected\n");
+ goto error;
+ }
+
+ timeout.tv_sec = SOCKET_TIMEOUT_CLIENT_DATA;
+ timeout.tv_usec = 0;
+
+ req1 = kmalloc(sizeof(*req1), GFP_ATOMIC );
+ if (!req1) {
+ printk(KERN_ERR "dnbd3: kmalloc failed\n");
+ goto error;
+ }
+
+ init_msghdr(msg);
+
+ if (dnbd3_sock_create(server->host.type, SOCK_STREAM, IPPROTO_TCP, &sock->sock) < 0) {
+ printk(KERN_ERR "dnbd3: could not create socket\n");
+ goto error;
+ }
+
+ kernel_setsockopt(sock->sock, SOL_SOCKET, SO_SNDTIMEO, (char *)&timeout, sizeof(timeout));
+ kernel_setsockopt(sock->sock, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout, sizeof(timeout));
+ sock->sock->sk->sk_allocation = GFP_NOIO;
+ if (server->host.type == HOST_IP4) {
+ struct sockaddr_in sin;
+ memset(&sin, 0, sizeof(sin));
+ sin.sin_family = AF_INET;
+ memcpy(&(sin.sin_addr), server->host.addr, 4);
+ sin.sin_port = server->host.port;
+ if (kernel_connect(sock->sock, (struct sockaddr *)&sin, sizeof(sin), 0) != 0) {
+ printk(KERN_ERR "dnbd3: connection to host failed (ipv4)\n");
+ goto error;
+ }
+ } else {
+ struct sockaddr_in6 sin;
+ memset(&sin, 0, sizeof(sin));
+ sin.sin6_family = AF_INET6;
+ memcpy(&(sin.sin6_addr), server->host.addr, 16);
+ sin.sin6_port = server->host.port;
+ if (kernel_connect(sock->sock, (struct sockaddr *)&sin, sizeof(sin), 0) != 0){
+ printk(KERN_ERR "dnbd3: connection to host failed (ipv6)\n");
+ goto error;
+ }
+ }
+ // Request filesize
+ dnbd3_request.magic = dnbd3_packet_magic;
+ dnbd3_request.cmd = CMD_SELECT_IMAGE;
+ iov[0].iov_base = &dnbd3_request;
+ iov[0].iov_len = sizeof(dnbd3_request);
+ serializer_reset_write(&payload_buffer);
+ serializer_put_uint16(&payload_buffer, PROTOCOL_VERSION);
+ serializer_put_string(&payload_buffer, dev->imgname);
+ serializer_put_uint16(&payload_buffer, dev->rid);
+ serializer_put_uint8(&payload_buffer, 0); // is_server = false
+ iov[1].iov_base = &payload_buffer;
+ dnbd3_request.size = iov[1].iov_len = serializer_get_written_length(&payload_buffer);
+ fixup_request(dnbd3_request);
+ mlen = sizeof(dnbd3_request) + iov[1].iov_len;
+ if (kernel_sendmsg(sock->sock, &msg, iov, 2, mlen) != mlen) {
+ printk(KERN_ERR "dnbd3: could not send CMD_SIZE_REQUEST\n");
+ goto error;
+ }
+ // receive reply header
+ iov[0].iov_base = &dnbd3_reply;
+ iov[0].iov_len = sizeof(dnbd3_reply);
+ if (kernel_recvmsg(sock->sock, &msg, iov, 1, sizeof(dnbd3_reply), msg.msg_flags) != sizeof(dnbd3_reply)) {
+ printk(KERN_ERR "dnbd3: received corrupted reply header after CMD_SIZE_REQUEST\n");
+ goto error;
+ }
+
+ // check reply header
+ fixup_reply(dnbd3_reply);
+ if (dnbd3_reply.cmd != CMD_SELECT_IMAGE ||
+ dnbd3_reply.size < 3 ||
+ dnbd3_reply.size > MAX_PAYLOAD ||
+ dnbd3_reply.magic != dnbd3_packet_magic) {
+ printk(KERN_ERR "dnbd3: received invalid reply to CMD_SIZE_REQUEST image does not exist on server\n");
+ goto error;
+ }
+
+ // receive reply payload
+ iov[0].iov_base = &payload_buffer;
+ iov[0].iov_len = dnbd3_reply.size;
+ if (kernel_recvmsg(sock->sock, &msg, iov, 1, dnbd3_reply.size, msg.msg_flags) != dnbd3_reply.size) {
+ printk(KERN_ERR "dnbd3: could not read CMD_SELECT_IMAGE payload on handshake\n");
+ goto error;
+ }
+
+ // handle/check reply payload
+ serializer_reset_read(&payload_buffer, dnbd3_reply.size);
+ server->protocol_version = serializer_get_uint16(&payload_buffer);
+ if (server->protocol_version < MIN_SUPPORTED_SERVER) {
+ printk(KERN_ERR "dnbd3: server version is lower than min supported version\n");
+ goto error;
+ }
+
+ name = serializer_get_string(&payload_buffer);
+ rid = serializer_get_uint16(&payload_buffer);
+ if (dev->rid != rid && strcmp(name, dev->imgname) != 0) {
+ printk(KERN_ERR "dnbd3: server offers image '%s', requested '%s'\n", name, dev->imgname);
+ goto error;
+ }
+
+ reported_size = serializer_get_uint64(&payload_buffer);
+ if (dev->reported_size == NULL) {
+ if (reported_size < 4096) {
+ printk(KERN_ERR "dnbd3: reported size by server is < 4096\n");
+ goto error;
+ }
+ dev->reported_size = reported_size;
+ set_capacity(dev->disk, dev->reported_size >> 9); /* 512 Byte blocks */
+ } else if (dev->reported_size != reported_size) {
+ printk(KERN_ERR "dnbd3: reported size by server is %llu but should be %llu\n", reported_size, dev->reported_size);
+ }
+
+ printk(KERN_DEBUG "dnbd3: connected to image %s, filesize %llu\n", dev->imgname, dev->reported_size);
+
+// TODO add heartbeat
+ // add heartbeat timer and scheduler for the command
+ INIT_WORK(&sock->keepalive, keepalive);
+ sock->heartbeat_count = 0;
+ timer_setup(&sock->keepalive_timer, dnbd3_keepalive, 0);
+ sock->keepalive_timer.expires = KEEPALIVE_TIMER;
+ add_timer(&sock->keepalive_timer);
+
+ mutex_unlock(&sock->lock);
+
+ return 0;
+error:
+ if (sock->sock) {
+ sock_release(sock->sock);
+ sock->sock = NULL;
+ }
+ if (req1) {
+ kfree(req1);
+ }
+ mutex_unlock(&sock->lock);
+ return result;
+}
+
+static int dnbd3_socket_disconnect(dnbd3_device *dev, dnbd3_sock *sock)
+{
+ printk(KERN_DEBUG "dnbd3: socket disconnect device %i\n", dev->minor);
+ mutex_lock(&sock->lock);
+
+ // clear heartbeat timer
+ del_timer_sync(&sock->keepalive_timer);
+// destroy_workqueue(&sock->keepalive);
+
+ if (sock->sock) {
+ kernel_sock_shutdown(sock->sock, SHUT_RDWR);
+ }
+
+ // clear socket
+ if (sock->sock) {
+ sock_release(sock->sock);
+ sock->sock = NULL;
+ }
+
+ mutex_unlock(&sock->lock);
+ mutex_destroy(&sock->lock);
+ return 0;
+}
+
+int dnbd3_net_disconnect(struct dnbd3_device *dev)
+{
+ int i;
+ int result;
+ del_timer_sync(&dev->discovery_timer);
+// destroy_workqueue(&dev->discovery);
+ for (i = 0; i < NUMBER_CONNECTIONS; i++) {
+ if (dev->socks[i].sock) {
+ if (dnbd3_socket_disconnect(dev, &dev->socks[i])) {
+ result = -EIO;
+ }
+ }
+ }
+ return result;
+}
+
+
+int dnbd3_net_connect(struct dnbd3_device *dev) {
+ // TODO decide which socket to connect
+ int result;
+ dev->socks[0].server = &dev->initial_server;
+ if (dnbd3_socket_connect(dev, &dev->socks[0]) == 0) {
+ printServerList(dev);
+
+ INIT_WORK(&dev->discovery, discovery);
+ timer_setup(&dev->discovery_timer, dnbd3_discovery, 0);
+ dev->discovery_timer.expires = DISCOVERY_TIMER;
+ add_timer(&dev->discovery_timer);
+
+ result = 0;
+ } else {
+ printk(KERN_ERR "dnbd3: failed to connect to initial server\n");
+ result = -ENOENT;
+ dev->imgname = NULL;
+ dev->socks[0].server = NULL;
+ }
+ return result;
+}
+
+
+
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-05-03 11:58:36 +0200