From 8aa12e9063201e0704f7ad3a34fb4bf8614a075d Mon Sep 17 00:00:00 2001 From: Frederic Robra Date: Tue, 2 Jul 2019 14:38:11 +0200 Subject: added code to connect to server --- Kbuild.in | 2 +- src/kernel/block.c | 230 ++++++++++++++++++++++++++++++++++++++++++++ src/kernel/block.h | 5 + src/kernel/core.c | 3 + src/kernel/dnbd3.h | 5 +- src/kernel/mq.c | 4 +- src/kernel/serialize_kmod.c | 5 + 7 files changed, 249 insertions(+), 5 deletions(-) create mode 100644 src/kernel/serialize_kmod.c diff --git a/Kbuild.in b/Kbuild.in index 1682c83..566a58b 100644 --- a/Kbuild.in +++ b/Kbuild.in @@ -1,2 +1,2 @@ obj-m := ${MODULE_NAME}.o -${MODULE_NAME}-objs += core.o sysfs.o block.o mq.o utils.o +${MODULE_NAME}-objs += core.o sysfs.o block.o mq.o utils.o serialize_kmod.o diff --git a/src/kernel/block.c b/src/kernel/block.c index bd2f8d7..4eb52c5 100644 --- a/src/kernel/block.c +++ b/src/kernel/block.c @@ -5,11 +5,21 @@ * Author: fred */ +#include #include "dnbd3.h" #include "block.h" +#include "clientconfig.h" +#define dnbd3_sock_create(af,type,proto,sock) sock_create_kern(&init_net, (af) == HOST_IP4 ? AF_INET : AF_INET6, type, proto, sock) +#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 int dnbd3_open(struct block_device *bdev, fmode_t mode) { @@ -34,16 +44,236 @@ void dnbd3_blk_fail_all_requests(dnbd3_device_t *dev) } + int dnbd3_net_connect(dnbd3_device_t *dev) { + struct request *req1 = NULL; + struct timeval timeout; + printk(KERN_DEBUG "dnbd3: net connect device %i\n", dev->minor); + + if (dev->disconnecting) { + printk(KERN_DEBUG "dnbd3: device still disconnecting\n"); + while (dev->disconnecting) + schedule(); + } + if (dev->request) { + printk(KERN_DEBUG "dnbd3: device still in request\n"); + while (dev->disconnecting) + schedule(); + } + + timeout.tv_sec = SOCKET_TIMEOUT_CLIENT_DATA; + timeout.tv_usec = 0; + + // do some checks before connecting + + req1 = kmalloc(sizeof(*req1), GFP_ATOMIC ); + if (!req1) { + printk(KERN_ERR "dnbd3: kmalloc failed\n"); + goto error; + } + if (dev->cur_server.host.port == 0 || dev->cur_server.host.type == 0 || dev->imgname == NULL ) { + printk(KERN_ERR "dnbd3: host, port or image name not set\n"); + goto error; + } + if (dev->sock) { + printk(KERN_WARNING "dnbd3: already connected\n"); + goto error; + } + + if (dev->cur_server.host.type != HOST_IP4 && dev->cur_server.host.type != HOST_IP6) { + printk(KERN_ERR "dnbd3: unknown address type %d\n", (int)dev->cur_server.host.type); + goto error; + } + + if (dev->better_sock == NULL ) { + // no established connection yet from discovery thread, start new one + dnbd3_request_t dnbd3_request; + dnbd3_reply_t dnbd3_reply; + struct msghdr msg; + struct kvec iov[2]; + uint16_t rid; + char *name; + int mlen; + init_msghdr(msg); + + if (dnbd3_sock_create(dev->cur_server.host.type, SOCK_STREAM, IPPROTO_TCP, &dev->sock) < 0) { + printk(KERN_ERR "dnbd3: could not create socket\n"); + goto error; + } + + kernel_setsockopt(dev->sock, SOL_SOCKET, SO_SNDTIMEO, (char *)&timeout, sizeof(timeout)); + kernel_setsockopt(dev->sock, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout, sizeof(timeout)); + dev->sock->sk->sk_allocation = GFP_NOIO; + if (dev->cur_server.host.type == HOST_IP4) { + struct sockaddr_in sin; + memset(&sin, 0, sizeof(sin)); + sin.sin_family = AF_INET; + memcpy(&(sin.sin_addr), dev->cur_server.host.addr, 4); + sin.sin_port = dev->cur_server.host.port; + if (kernel_connect(dev->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), dev->cur_server.host.addr, 16); + sin.sin6_port = dev->cur_server.host.port; + if (kernel_connect(dev->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(&dev->payload_buffer); + serializer_put_uint16(&dev->payload_buffer, PROTOCOL_VERSION); + serializer_put_string(&dev->payload_buffer, dev->imgname); + serializer_put_uint16(&dev->payload_buffer, dev->rid); + serializer_put_uint8(&dev->payload_buffer, 0); // is_server = false + iov[1].iov_base = &dev->payload_buffer; + dnbd3_request.size = iov[1].iov_len = serializer_get_written_length(&dev->payload_buffer); + fixup_request(dnbd3_request); + mlen = sizeof(dnbd3_request) + iov[1].iov_len; + if (kernel_sendmsg(dev->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(dev->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 = &dev->payload_buffer; + iov[0].iov_len = dnbd3_reply.size; + if (kernel_recvmsg(dev->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(&dev->payload_buffer, dnbd3_reply.size); + dev->cur_server.protocol_version = serializer_get_uint16(&dev->payload_buffer); + if (dev->cur_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(&dev->payload_buffer); + if (dev->rid != 0 && strcmp(name, dev->imgname) != 0) { + printk(KERN_ERR "dnbd3: server offers image '%s', requested '%s'\n", name, dev->imgname); + goto error; + } + + if (strlen(dev->imgname) < strlen(name)) { + dev->imgname = krealloc(dev->imgname, strlen(name) + 1, GFP_ATOMIC ); + if (dev->imgname == NULL ) { + printk(KERN_ERR "dnbd3: reallocating buffer for new image name failed\n"); + goto error; + } + } + strcpy(dev->imgname, name); + rid = serializer_get_uint16(&dev->payload_buffer); + if (dev->rid != 0 && dev->rid != rid) { + printk(KERN_ERR "dnbd3: server provides rid %d, requested was %d\n", (int)rid, (int)dev->rid); + goto error; + } + + dev->rid = rid; + dev->reported_size = serializer_get_uint64(&dev->payload_buffer); + if (dev->reported_size < 4096) { + printk(KERN_ERR "dnbd3: reported size by server is < 4096\n"); + goto error; + } + + // store image information + set_capacity(dev->disk, dev->reported_size >> 9); /* 512 Byte blocks */ + printk(KERN_DEBUG "dnbd3: connected to image %s, filesize %llu\n", dev->imgname, dev->reported_size); + dev->update_available = 0; + } else { // Switching server, connection is already established and size request was executed + + printk(KERN_DEBUG "dnbd3: changing server\n"); + dev->sock = dev->better_sock; + dev->better_sock = NULL; + kernel_setsockopt(dev->sock, SOL_SOCKET, SO_SNDTIMEO, (char *)&timeout, sizeof(timeout)); + kernel_setsockopt(dev->sock, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout, sizeof(timeout)); + } + + dev->panic = 0; + dev->panic_count = 0; + + // Enqueue request to request_queue_send for a fresh list of alt servers + //TODO refresh alt server list + + // add heartbeat timer + //TODO needed anymore= +// dev->heartbeat_count = 0; +// timer_setup(&dev->hb_timer, dnbd3_net_heartbeat, 0); +// dev->hb_timer.expires = jiffies + HZ; +// add_timer(&dev->hb_timer); return 0; +error: + if (dev->sock) { + sock_release(dev->sock); + dev->sock = NULL; + } + dev->cur_server.host.type = 0; + dev->cur_server.host.port = 0; + if (req1) { + kfree(req1); + } + return -1; } int dnbd3_net_disconnect(dnbd3_device_t *dev) { printk(KERN_DEBUG "dnbd3: net disconnect device %i\n", dev->minor); + if (dev->disconnecting) { + return 0; + } + + dev->disconnecting = 1; + + // clear heartbeat timer +// del_timer(&dev->hb_timer); + + dev->discover = 0; + + if (dev->sock) { + kernel_sock_shutdown(dev->sock, SHUT_RDWR); + } + + // clear socket + if (dev->sock) { + sock_release(dev->sock); + dev->sock = NULL; + } + dev->cur_server.host.type = 0; + dev->cur_server.host.port = 0; + + dev->disconnecting = 0; + return 0; } diff --git a/src/kernel/block.h b/src/kernel/block.h index 5493a00..af99108 100644 --- a/src/kernel/block.h +++ b/src/kernel/block.h @@ -8,6 +8,11 @@ #ifndef SRC_KERNEL_BLOCK_H_ #define SRC_KERNEL_BLOCK_H_ + +int dnbd3_net_connect(dnbd3_device_t *dev); + +int dnbd3_net_disconnect(dnbd3_device_t *dev); + extern struct block_device_operations dnbd3_fops; diff --git a/src/kernel/core.c b/src/kernel/core.c index 7725a1d..3b30a11 100644 --- a/src/kernel/core.c +++ b/src/kernel/core.c @@ -427,6 +427,9 @@ static void dnbd3_dev_remove(struct dnbd3_device_t *dnbd3) del_gendisk(disk); blk_cleanup_queue(q); blk_mq_free_tag_set(&dnbd3->tag_set); + if (dnbd3->sock) { + dnbd3_net_disconnect(dnbd3); + } disk->private_data = NULL; put_disk(disk); } diff --git a/src/kernel/dnbd3.h b/src/kernel/dnbd3.h index b8b0f59..3fb625a 100644 --- a/src/kernel/dnbd3.h +++ b/src/kernel/dnbd3.h @@ -28,6 +28,7 @@ #define KERNEL_MODULE #include "types.h" +#include "serialize.h" typedef struct { @@ -58,11 +59,11 @@ typedef struct dnbd3_device_t { struct socket *sock; dnbd3_server_t cur_server, initial_server; uint64_t cur_rtt; -// serialized_buffer_t payload_buffer; + serialized_buffer_t payload_buffer; dnbd3_server_t alt_servers[NUMBER_SERVERS]; // array of alt servers int new_servers_num; // number of new alt servers that are waiting to be copied to above array dnbd3_server_entry_t new_servers[NUMBER_SERVERS]; // pending new alt servers - uint8_t discover, panic, disconnecting, update_available, panic_count; + uint8_t discover, panic, disconnecting, update_available, panic_count, request; uint8_t use_server_provided_alts; uint16_t rid; uint32_t heartbeat_count; diff --git a/src/kernel/mq.c b/src/kernel/mq.c index d402ecf..ee60574 100644 --- a/src/kernel/mq.c +++ b/src/kernel/mq.c @@ -16,7 +16,7 @@ static int dnbd3_handle_cmd(struct dnbd3_cmd *cmd, int index) struct request *req = blk_mq_rq_from_pdu(cmd); struct dnbd3_device_t *dev = cmd->dnbd3; struct dnbd3_sock *nsock; - int ret; + int ret = -1; printk(KERN_DEBUG "dnbd3: handle command %i device %i\n", cmd->cmd_cookie, dev->minor); @@ -46,7 +46,7 @@ static blk_status_t dnbd3_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_ ret = BLK_STS_OK; mutex_unlock(&cmd->lock); - return -10; + return ret; } static void dnbd3_complete_rq(struct request *req) diff --git a/src/kernel/serialize_kmod.c b/src/kernel/serialize_kmod.c new file mode 100644 index 0000000..50746df --- /dev/null +++ b/src/kernel/serialize_kmod.c @@ -0,0 +1,5 @@ +#include +#include + +#define KERNEL_MODULE +#include "serialize.c" -- cgit v1.2.3-55-g7522