diff options
Diffstat (limited to 'src/kernel/main.c')
| -rw-r--r-- | src/kernel/main.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/src/kernel/main.c b/src/kernel/main.c new file mode 100644 index 0000000..1802b5f --- /dev/null +++ b/src/kernel/main.c @@ -0,0 +1,216 @@ +#include <linux/fs.h> +#include <linux/module.h> +#include <linux/blkdev.h> +#include <net/sock.h> + +// Own +#include "config.h" +#include "include/types.h" + +static int major; +static struct gendisk *disk; +static struct request_queue *dnbd3_queue; + +DEFINE_SPINLOCK( dnbd3_lock); + +static struct socket *_sock; +static struct dnbd3_request _dnbd3_request; +static struct dnbd3_reply _dnbd3_reply; + +static char* host; +static char* port; + +unsigned int inet_addr(char *str) +{ + int a, b, c, d; + char arr[4]; + sscanf(str, "%d.%d.%d.%d", &a, &b, &c, &d); + arr[0] = a; + arr[1] = b; + arr[2] = c; + arr[3] = d; + return *(unsigned int*) arr; +} + +void connect(void) +{ + if (!host || !port) + { + printk("ERROR: Host or port not set."); + return; + } + + // initialize socket + struct sockaddr_in sin; + if (sock_create_kern(AF_INET, SOCK_STREAM, IPPROTO_TCP, &_sock) < 0) + { + printk("ERROR: dnbd3 couldn't create socket.\n"); + return; + } + sin.sin_family = AF_INET; + sin.sin_addr.s_addr = inet_addr(host); + sin.sin_port = htons(simple_strtol(port, NULL, 10)); + if (kernel_connect(_sock, (struct sockaddr *) &sin, sizeof(sin), 0) < 0) + { + printk("ERROR: dnbd3 couldn't connect to given host.\n"); + return; + } + + // prepare message + struct msghdr msg; + struct kvec iov; + _sock->sk->sk_allocation = GFP_NOIO; // GFP_NOIO: blocking is possible, but no I/O will be performed. + msg.msg_name = NULL; + msg.msg_namelen = 0; + msg.msg_control = NULL; + msg.msg_controllen = 0; + msg.msg_flags = MSG_WAITALL | MSG_NOSIGNAL; // No SIGPIPE + + // send request + _dnbd3_request.cmd = CMD_GET_SIZE; + iov.iov_base = &_dnbd3_request; + iov.iov_len = sizeof(_dnbd3_request); + kernel_sendmsg(_sock, &msg, &iov, 1, sizeof(_dnbd3_request)); + + // receive replay + iov.iov_base = &_dnbd3_reply; + iov.iov_len = sizeof(_dnbd3_reply); + kernel_recvmsg(_sock, &msg, &iov, 1, sizeof(_dnbd3_reply), msg.msg_flags); + + // set filesize + printk("INFO: dnbd3 filesize: %llu\n", _dnbd3_reply.filesize); + set_capacity(disk, _dnbd3_reply.filesize >> 9); /* 512 Byte blocks */ +} + +void dnbd3_request(struct request_queue *q) +{ + if (!_sock) + return; + + struct request *req; + struct msghdr msg; + struct kvec iov; + + _sock->sk->sk_allocation = GFP_NOIO; // GFP_NOIO: blocking is possible, but no I/O will be performed. + msg.msg_name = NULL; + msg.msg_namelen = 0; + msg.msg_control = NULL; + msg.msg_controllen = 0; + msg.msg_flags = MSG_WAITALL | MSG_NOSIGNAL; // No SIGPIPE + + while ((req = blk_fetch_request(q)) != NULL) + { + if (req->cmd_type != REQ_TYPE_FS) + { + if (!__blk_end_request_cur(req, 0)) + req = blk_fetch_request(q); + continue; + } + + spin_unlock_irq(q->queue_lock); + if (rq_data_dir(req) == READ) + { + _dnbd3_request.cmd = CMD_GET_BLOCK; + _dnbd3_request.offset = blk_rq_pos(req) << 9; // *512 + _dnbd3_request.size = blk_rq_bytes(req); // blk_rq_bytes() Returns bytes left to complete in the entire request + + // send request + iov.iov_base = &_dnbd3_request; + iov.iov_len = sizeof(_dnbd3_request); + kernel_sendmsg(_sock, &msg, &iov, 1, sizeof(_dnbd3_request)); + + // receive replay + struct req_iterator iter; + struct bio_vec *bvec; + rq_for_each_segment(bvec, req, iter) + { + iov.iov_base = kmap(bvec->bv_page) + bvec->bv_offset; + iov.iov_len = bvec->bv_len; + kernel_recvmsg(_sock, &msg, &iov, 1, bvec->bv_len, msg.msg_flags); + kunmap(bvec->bv_page); + } + } + + spin_lock_irq(q->queue_lock); + __blk_end_request_all(req, 0); + } +} + +int dnbd3_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + switch (cmd) + { + case IOCTL_SET_HOST: + host = (char *) arg; + break; + + case IOCTL_SET_PORT: + port = (char *) arg; + break; + + case IOCTL_CONNECT: + connect(); + break; + case BLKFLSBUF: + // TODO: if missing, hdparm tells "BLKFLSBUF failed: Operation not permitted". Figure out what this should do. + break; + + default: + return -1; + + } + return 0; +} + +struct block_device_operations dnbd3_ops = +{ .owner = THIS_MODULE, .ioctl = dnbd3_ioctl, }; + +static int __init dnbd3_init(void) +{ + // Init blkdev + if ((major = register_blkdev(0, "dnbd")) == 0) + { + printk("ERROR: dnbd3 register_blkdev failed.\n"); + return -EIO; + } + if (!(disk = alloc_disk(1))) + { + printk("ERROR: dnbd3 alloc_disk failed.\n"); + return -EIO; + } + disk->major = major; + disk->first_minor = 0; + sprintf(disk->disk_name, "dnbd0"); + set_capacity(disk, 0); + //set_disk_ro(disk, 1); + disk->fops = &dnbd3_ops; + + if ((dnbd3_queue = blk_init_queue(&dnbd3_request, &dnbd3_lock)) == NULL) + { + printk("ERROR: dnbd3 blk_init_queue failed.\n"); + return -EIO; + } + + blk_queue_logical_block_size(dnbd3_queue, DNBD3_BLOCK_SIZE); // set logical block size for the queue + disk->queue = dnbd3_queue; + + add_disk(disk); + printk("INFO: dnbd3 init successful.\n"); + return 0; +} + +static void __exit dnbd3_exit(void) +{ + if (_sock) + sock_release(_sock); + unregister_blkdev(major, "dnbd"); + del_gendisk(disk); + put_disk(disk); + blk_cleanup_queue(dnbd3_queue); + printk("INFO: dnbd3 exit.\n"); +} + +module_init( dnbd3_init); +module_exit( dnbd3_exit); +MODULE_LICENSE("GPL"); |