diff options
Diffstat (limited to 'drivers/scsi/iscsi_tcp.c')
| -rw-r--r-- | drivers/scsi/iscsi_tcp.c | 1062 |
1 files changed, 1062 insertions, 0 deletions
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c new file mode 100644 index 000000000..7212e3a13 --- /dev/null +++ b/drivers/scsi/iscsi_tcp.c @@ -0,0 +1,1062 @@ +/* + * iSCSI Initiator over TCP/IP Data-Path + * + * Copyright (C) 2004 Dmitry Yusupov + * Copyright (C) 2004 Alex Aizman + * Copyright (C) 2005 - 2006 Mike Christie + * Copyright (C) 2006 Red Hat, Inc. All rights reserved. + * maintained by open-iscsi@googlegroups.com + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published + * by the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * See the file COPYING included with this distribution for more details. + * + * Credits: + * Christoph Hellwig + * FUJITA Tomonori + * Arne Redlich + * Zhenyu Wang + */ + +#include <crypto/hash.h> +#include <linux/types.h> +#include <linux/inet.h> +#include <linux/slab.h> +#include <linux/sched/mm.h> +#include <linux/file.h> +#include <linux/blkdev.h> +#include <linux/delay.h> +#include <linux/kfifo.h> +#include <linux/scatterlist.h> +#include <linux/module.h> +#include <linux/backing-dev.h> +#include <net/tcp.h> +#include <scsi/scsi_cmnd.h> +#include <scsi/scsi_device.h> +#include <scsi/scsi_host.h> +#include <scsi/scsi.h> +#include <scsi/scsi_transport_iscsi.h> + +#include "iscsi_tcp.h" + +MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, " + "Dmitry Yusupov <dmitry_yus@yahoo.com>, " + "Alex Aizman <itn780@yahoo.com>"); +MODULE_DESCRIPTION("iSCSI/TCP data-path"); +MODULE_LICENSE("GPL"); + +static struct scsi_transport_template *iscsi_sw_tcp_scsi_transport; +static struct scsi_host_template iscsi_sw_tcp_sht; +static struct iscsi_transport iscsi_sw_tcp_transport; + +static unsigned int iscsi_max_lun = ~0; +module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO); + +static int iscsi_sw_tcp_dbg; +module_param_named(debug_iscsi_tcp, iscsi_sw_tcp_dbg, int, + S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(debug_iscsi_tcp, "Turn on debugging for iscsi_tcp module " + "Set to 1 to turn on, and zero to turn off. Default is off."); + +#define ISCSI_SW_TCP_DBG(_conn, dbg_fmt, arg...) \ + do { \ + if (iscsi_sw_tcp_dbg) \ + iscsi_conn_printk(KERN_INFO, _conn, \ + "%s " dbg_fmt, \ + __func__, ##arg); \ + } while (0); + + +/** + * iscsi_sw_tcp_recv - TCP receive in sendfile fashion + * @rd_desc: read descriptor + * @skb: socket buffer + * @offset: offset in skb + * @len: skb->len - offset + */ +static int iscsi_sw_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, + unsigned int offset, size_t len) +{ + struct iscsi_conn *conn = rd_desc->arg.data; + unsigned int consumed, total_consumed = 0; + int status; + + ISCSI_SW_TCP_DBG(conn, "in %d bytes\n", skb->len - offset); + + do { + status = 0; + consumed = iscsi_tcp_recv_skb(conn, skb, offset, 0, &status); + offset += consumed; + total_consumed += consumed; + } while (consumed != 0 && status != ISCSI_TCP_SKB_DONE); + + ISCSI_SW_TCP_DBG(conn, "read %d bytes status %d\n", + skb->len - offset, status); + return total_consumed; +} + +/** + * iscsi_sw_sk_state_check - check socket state + * @sk: socket + * + * If the socket is in CLOSE or CLOSE_WAIT we should + * not close the connection if there is still some + * data pending. + * + * Must be called with sk_callback_lock. + */ +static inline int iscsi_sw_sk_state_check(struct sock *sk) +{ + struct iscsi_conn *conn = sk->sk_user_data; + + if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) && + (conn->session->state != ISCSI_STATE_LOGGING_OUT) && + !atomic_read(&sk->sk_rmem_alloc)) { + ISCSI_SW_TCP_DBG(conn, "TCP_CLOSE|TCP_CLOSE_WAIT\n"); + iscsi_conn_failure(conn, ISCSI_ERR_TCP_CONN_CLOSE); + return -ECONNRESET; + } + return 0; +} + +static void iscsi_sw_tcp_data_ready(struct sock *sk) +{ + struct iscsi_conn *conn; + struct iscsi_tcp_conn *tcp_conn; + read_descriptor_t rd_desc; + + read_lock_bh(&sk->sk_callback_lock); + conn = sk->sk_user_data; + if (!conn) { + read_unlock_bh(&sk->sk_callback_lock); + return; + } + tcp_conn = conn->dd_data; + + /* + * Use rd_desc to pass 'conn' to iscsi_tcp_recv. + * We set count to 1 because we want the network layer to + * hand us all the skbs that are available. iscsi_tcp_recv + * handled pdus that cross buffers or pdus that still need data. + */ + rd_desc.arg.data = conn; + rd_desc.count = 1; + tcp_read_sock(sk, &rd_desc, iscsi_sw_tcp_recv); + + iscsi_sw_sk_state_check(sk); + + /* If we had to (atomically) map a highmem page, + * unmap it now. */ + iscsi_tcp_segment_unmap(&tcp_conn->in.segment); + read_unlock_bh(&sk->sk_callback_lock); +} + +static void iscsi_sw_tcp_state_change(struct sock *sk) +{ + struct iscsi_tcp_conn *tcp_conn; + struct iscsi_sw_tcp_conn *tcp_sw_conn; + struct iscsi_conn *conn; + void (*old_state_change)(struct sock *); + + read_lock_bh(&sk->sk_callback_lock); + conn = sk->sk_user_data; + if (!conn) { + read_unlock_bh(&sk->sk_callback_lock); + return; + } + + iscsi_sw_sk_state_check(sk); + + tcp_conn = conn->dd_data; + tcp_sw_conn = tcp_conn->dd_data; + old_state_change = tcp_sw_conn->old_state_change; + + read_unlock_bh(&sk->sk_callback_lock); + + old_state_change(sk); +} + +/** + * iscsi_write_space - Called when more output buffer space is available + * @sk: socket space is available for + **/ +static void iscsi_sw_tcp_write_space(struct sock *sk) +{ + struct iscsi_conn *conn; + struct iscsi_tcp_conn *tcp_conn; + struct iscsi_sw_tcp_conn *tcp_sw_conn; + void (*old_write_space)(struct sock *); + + read_lock_bh(&sk->sk_callback_lock); + conn = sk->sk_user_data; + if (!conn) { + read_unlock_bh(&sk->sk_callback_lock); + return; + } + + tcp_conn = conn->dd_data; + tcp_sw_conn = tcp_conn->dd_data; + old_write_space = tcp_sw_conn->old_write_space; + read_unlock_bh(&sk->sk_callback_lock); + + old_write_space(sk); + + ISCSI_SW_TCP_DBG(conn, "iscsi_write_space\n"); + iscsi_conn_queue_work(conn); +} + +static void iscsi_sw_tcp_conn_set_callbacks(struct iscsi_conn *conn) +{ + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + struct sock *sk = tcp_sw_conn->sock->sk; + + /* assign new callbacks */ + write_lock_bh(&sk->sk_callback_lock); + sk->sk_user_data = conn; + tcp_sw_conn->old_data_ready = sk->sk_data_ready; + tcp_sw_conn->old_state_change = sk->sk_state_change; + tcp_sw_conn->old_write_space = sk->sk_write_space; + sk->sk_data_ready = iscsi_sw_tcp_data_ready; + sk->sk_state_change = iscsi_sw_tcp_state_change; + sk->sk_write_space = iscsi_sw_tcp_write_space; + write_unlock_bh(&sk->sk_callback_lock); +} + +static void +iscsi_sw_tcp_conn_restore_callbacks(struct iscsi_conn *conn) +{ + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + struct sock *sk = tcp_sw_conn->sock->sk; + + /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */ + write_lock_bh(&sk->sk_callback_lock); + sk->sk_user_data = NULL; + sk->sk_data_ready = tcp_sw_conn->old_data_ready; + sk->sk_state_change = tcp_sw_conn->old_state_change; + sk->sk_write_space = tcp_sw_conn->old_write_space; + sk->sk_no_check_tx = 0; + write_unlock_bh(&sk->sk_callback_lock); +} + +/** + * iscsi_sw_tcp_xmit_segment - transmit segment + * @tcp_conn: the iSCSI TCP connection + * @segment: the buffer to transmnit + * + * This function transmits as much of the buffer as + * the network layer will accept, and returns the number of + * bytes transmitted. + * + * If CRC hashing is enabled, the function will compute the + * hash as it goes. When the entire segment has been transmitted, + * it will retrieve the hash value and send it as well. + */ +static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn, + struct iscsi_segment *segment) +{ + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + struct socket *sk = tcp_sw_conn->sock; + unsigned int copied = 0; + int r = 0; + + while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) { + struct scatterlist *sg; + unsigned int offset, copy; + int flags = 0; + + r = 0; + offset = segment->copied; + copy = segment->size - offset; + + if (segment->total_copied + segment->size < segment->total_size) + flags |= MSG_MORE; + + /* Use sendpage if we can; else fall back to sendmsg */ + if (!segment->data) { + sg = segment->sg; + offset += segment->sg_offset + sg->offset; + r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset, + copy, flags); + } else { + struct msghdr msg = { .msg_flags = flags }; + struct kvec iov = { + .iov_base = segment->data + offset, + .iov_len = copy + }; + + r = kernel_sendmsg(sk, &msg, &iov, 1, copy); + } + + if (r < 0) { + iscsi_tcp_segment_unmap(segment); + return r; + } + copied += r; + } + return copied; +} + +/** + * iscsi_sw_tcp_xmit - TCP transmit + * @conn: iscsi connection + **/ +static int iscsi_sw_tcp_xmit(struct iscsi_conn *conn) +{ + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + struct iscsi_segment *segment = &tcp_sw_conn->out.segment; + unsigned int consumed = 0; + int rc = 0; + + while (1) { + rc = iscsi_sw_tcp_xmit_segment(tcp_conn, segment); + /* + * We may not have been able to send data because the conn + * is getting stopped. libiscsi will know so propagate err + * for it to do the right thing. + */ + if (rc == -EAGAIN) + return rc; + else if (rc < 0) { + rc = ISCSI_ERR_XMIT_FAILED; + goto error; + } else if (rc == 0) + break; + + consumed += rc; + + if (segment->total_copied >= segment->total_size) { + if (segment->done != NULL) { + rc = segment->done(tcp_conn, segment); + if (rc != 0) + goto error; + } + } + } + + ISCSI_SW_TCP_DBG(conn, "xmit %d bytes\n", consumed); + + conn->txdata_octets += consumed; + return consumed; + +error: + /* Transmit error. We could initiate error recovery + * here. */ + ISCSI_SW_TCP_DBG(conn, "Error sending PDU, errno=%d\n", rc); + iscsi_conn_failure(conn, rc); + return -EIO; +} + +/** + * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit + * @conn: iscsi connection + */ +static inline int iscsi_sw_tcp_xmit_qlen(struct iscsi_conn *conn) +{ + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + struct iscsi_segment *segment = &tcp_sw_conn->out.segment; + + return segment->total_copied - segment->total_size; +} + +static int iscsi_sw_tcp_pdu_xmit(struct iscsi_task *task) +{ + struct iscsi_conn *conn = task->conn; + unsigned int noreclaim_flag; + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + int rc = 0; + + if (!tcp_sw_conn->sock) { + iscsi_conn_printk(KERN_ERR, conn, + "Transport not bound to socket!\n"); + return -EINVAL; + } + + noreclaim_flag = memalloc_noreclaim_save(); + + while (iscsi_sw_tcp_xmit_qlen(conn)) { + rc = iscsi_sw_tcp_xmit(conn); + if (rc == 0) { + rc = -EAGAIN; + break; + } + if (rc < 0) + break; + rc = 0; + } + + memalloc_noreclaim_restore(noreclaim_flag); + return rc; +} + +/* + * This is called when we're done sending the header. + * Simply copy the data_segment to the send segment, and return. + */ +static int iscsi_sw_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn, + struct iscsi_segment *segment) +{ + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + + tcp_sw_conn->out.segment = tcp_sw_conn->out.data_segment; + ISCSI_SW_TCP_DBG(tcp_conn->iscsi_conn, + "Header done. Next segment size %u total_size %u\n", + tcp_sw_conn->out.segment.size, + tcp_sw_conn->out.segment.total_size); + return 0; +} + +static void iscsi_sw_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr, + size_t hdrlen) +{ + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + + ISCSI_SW_TCP_DBG(conn, "%s\n", conn->hdrdgst_en ? + "digest enabled" : "digest disabled"); + + /* Clear the data segment - needs to be filled in by the + * caller using iscsi_tcp_send_data_prep() */ + memset(&tcp_sw_conn->out.data_segment, 0, + sizeof(struct iscsi_segment)); + + /* If header digest is enabled, compute the CRC and + * place the digest into the same buffer. We make + * sure that both iscsi_tcp_task and mtask have + * sufficient room. + */ + if (conn->hdrdgst_en) { + iscsi_tcp_dgst_header(tcp_sw_conn->tx_hash, hdr, hdrlen, + hdr + hdrlen); + hdrlen += ISCSI_DIGEST_SIZE; + } + + /* Remember header pointer for later, when we need + * to decide whether there's a payload to go along + * with the header. */ + tcp_sw_conn->out.hdr = hdr; + + iscsi_segment_init_linear(&tcp_sw_conn->out.segment, hdr, hdrlen, + iscsi_sw_tcp_send_hdr_done, NULL); +} + +/* + * Prepare the send buffer for the payload data. + * Padding and checksumming will all be taken care + * of by the iscsi_segment routines. + */ +static int +iscsi_sw_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg, + unsigned int count, unsigned int offset, + unsigned int len) +{ + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + struct ahash_request *tx_hash = NULL; + unsigned int hdr_spec_len; + + ISCSI_SW_TCP_DBG(conn, "offset=%d, datalen=%d %s\n", offset, len, + conn->datadgst_en ? + "digest enabled" : "digest disabled"); + + /* Make sure the datalen matches what the caller + said he would send. */ + hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength); + WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); + + if (conn->datadgst_en) + tx_hash = tcp_sw_conn->tx_hash; + + return iscsi_segment_seek_sg(&tcp_sw_conn->out.data_segment, + sg, count, offset, len, + NULL, tx_hash); +} + +static void +iscsi_sw_tcp_send_linear_data_prep(struct iscsi_conn *conn, void *data, + size_t len) +{ + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + struct ahash_request *tx_hash = NULL; + unsigned int hdr_spec_len; + + ISCSI_SW_TCP_DBG(conn, "datalen=%zd %s\n", len, conn->datadgst_en ? + "digest enabled" : "digest disabled"); + + /* Make sure the datalen matches what the caller + said he would send. */ + hdr_spec_len = ntoh24(tcp_sw_conn->out.hdr->dlength); + WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); + + if (conn->datadgst_en) + tx_hash = tcp_sw_conn->tx_hash; + + iscsi_segment_init_linear(&tcp_sw_conn->out.data_segment, + data, len, NULL, tx_hash); +} + +static int iscsi_sw_tcp_pdu_init(struct iscsi_task *task, + unsigned int offset, unsigned int count) +{ + struct iscsi_conn *conn = task->conn; + int err = 0; + + iscsi_sw_tcp_send_hdr_prep(conn, task->hdr, task->hdr_len); + + if (!count) + return 0; + + if (!task->sc) + iscsi_sw_tcp_send_linear_data_prep(conn, task->data, count); + else { + struct scsi_data_buffer *sdb = scsi_out(task->sc); + + err = iscsi_sw_tcp_send_data_prep(conn, sdb->table.sgl, + sdb->table.nents, offset, + count); + } + + if (err) { + /* got invalid offset/len */ + return -EIO; + } + return 0; +} + +static int iscsi_sw_tcp_pdu_alloc(struct iscsi_task *task, uint8_t opcode) +{ + struct iscsi_tcp_task *tcp_task = task->dd_data; + + task->hdr = task->dd_data + sizeof(*tcp_task); + task->hdr_max = sizeof(struct iscsi_sw_tcp_hdrbuf) - ISCSI_DIGEST_SIZE; + return 0; +} + +static struct iscsi_cls_conn * +iscsi_sw_tcp_conn_create(struct iscsi_cls_session *cls_session, + uint32_t conn_idx) +{ + struct iscsi_conn *conn; + struct iscsi_cls_conn *cls_conn; + struct iscsi_tcp_conn *tcp_conn; + struct iscsi_sw_tcp_conn *tcp_sw_conn; + struct crypto_ahash *tfm; + + cls_conn = iscsi_tcp_conn_setup(cls_session, sizeof(*tcp_sw_conn), + conn_idx); + if (!cls_conn) + return NULL; + conn = cls_conn->dd_data; + tcp_conn = conn->dd_data; + tcp_sw_conn = tcp_conn->dd_data; + + tfm = crypto_alloc_ahash("crc32c", 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(tfm)) + goto free_conn; + + tcp_sw_conn->tx_hash = ahash_request_alloc(tfm, GFP_KERNEL); + if (!tcp_sw_conn->tx_hash) + goto free_tfm; + ahash_request_set_callback(tcp_sw_conn->tx_hash, 0, NULL, NULL); + + tcp_sw_conn->rx_hash = ahash_request_alloc(tfm, GFP_KERNEL); + if (!tcp_sw_conn->rx_hash) + goto free_tx_hash; + ahash_request_set_callback(tcp_sw_conn->rx_hash, 0, NULL, NULL); + + tcp_conn->rx_hash = tcp_sw_conn->rx_hash; + + return cls_conn; + +free_tx_hash: + ahash_request_free(tcp_sw_conn->tx_hash); +free_tfm: + crypto_free_ahash(tfm); +free_conn: + iscsi_conn_printk(KERN_ERR, conn, + "Could not create connection due to crc32c " + "loading error. Make sure the crc32c " + "module is built as a module or into the " + "kernel\n"); + iscsi_tcp_conn_teardown(cls_conn); + return NULL; +} + +static void iscsi_sw_tcp_release_conn(struct iscsi_conn *conn) +{ + struct iscsi_session *session = conn->session; + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + struct socket *sock = tcp_sw_conn->sock; + + if (!sock) + return; + + sock_hold(sock->sk); + iscsi_sw_tcp_conn_restore_callbacks(conn); + sock_put(sock->sk); + + spin_lock_bh(&session->frwd_lock); + tcp_sw_conn->sock = NULL; + spin_unlock_bh(&session->frwd_lock); + sockfd_put(sock); +} + +static void iscsi_sw_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn) +{ + struct iscsi_conn *conn = cls_conn->dd_data; + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + + iscsi_sw_tcp_release_conn(conn); + + ahash_request_free(tcp_sw_conn->rx_hash); + if (tcp_sw_conn->tx_hash) { + struct crypto_ahash *tfm; + + tfm = crypto_ahash_reqtfm(tcp_sw_conn->tx_hash); + ahash_request_free(tcp_sw_conn->tx_hash); + crypto_free_ahash(tfm); + } + + iscsi_tcp_conn_teardown(cls_conn); +} + +static void iscsi_sw_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) +{ + struct iscsi_conn *conn = cls_conn->dd_data; + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + struct socket *sock = tcp_sw_conn->sock; + + /* userspace may have goofed up and not bound us */ + if (!sock) + return; + + sock->sk->sk_err = EIO; + wake_up_interruptible(sk_sleep(sock->sk)); + + /* stop xmit side */ + iscsi_suspend_tx(conn); + + /* stop recv side and release socket */ + iscsi_sw_tcp_release_conn(conn); + + iscsi_conn_stop(cls_conn, flag); +} + +static int +iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session, + struct iscsi_cls_conn *cls_conn, uint64_t transport_eph, + int is_leading) +{ + struct iscsi_session *session = cls_session->dd_data; + struct iscsi_conn *conn = cls_conn->dd_data; + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + struct sock *sk; + struct socket *sock; + int err; + + /* lookup for existing socket */ + sock = sockfd_lookup((int)transport_eph, &err); + if (!sock) { + iscsi_conn_printk(KERN_ERR, conn, + "sockfd_lookup failed %d\n", err); + return -EEXIST; + } + + err = iscsi_conn_bind(cls_session, cls_conn, is_leading); + if (err) + goto free_socket; + + spin_lock_bh(&session->frwd_lock); + /* bind iSCSI connection and socket */ + tcp_sw_conn->sock = sock; + spin_unlock_bh(&session->frwd_lock); + + /* setup Socket parameters */ + sk = sock->sk; + sk->sk_reuse = SK_CAN_REUSE; + sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */ + sk->sk_allocation = GFP_ATOMIC; + sk_set_memalloc(sk); + + iscsi_sw_tcp_conn_set_callbacks(conn); + tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage; + /* + * set receive state machine into initial state + */ + iscsi_tcp_hdr_recv_prep(tcp_conn); + return 0; + +free_socket: + sockfd_put(sock); + return err; +} + +static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn, + enum iscsi_param param, char *buf, + int buflen) +{ + struct iscsi_conn *conn = cls_conn->dd_data; + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + + switch(param) { + case ISCSI_PARAM_HDRDGST_EN: + iscsi_set_param(cls_conn, param, buf, buflen); + break; + case ISCSI_PARAM_DATADGST_EN: + iscsi_set_param(cls_conn, param, buf, buflen); + tcp_sw_conn->sendpage = conn->datadgst_en ? + sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage; + break; + case ISCSI_PARAM_MAX_R2T: + return iscsi_tcp_set_max_r2t(conn, buf); + default: + return iscsi_set_param(cls_conn, param, buf, buflen); + } + + return 0; +} + +static int iscsi_sw_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn, + enum iscsi_param param, char *buf) +{ + struct iscsi_conn *conn = cls_conn->dd_data; + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + struct sockaddr_in6 addr; + int rc; + + switch(param) { + case ISCSI_PARAM_CONN_PORT: + case ISCSI_PARAM_CONN_ADDRESS: + case ISCSI_PARAM_LOCAL_PORT: + spin_lock_bh(&conn->session->frwd_lock); + if (!tcp_sw_conn || !tcp_sw_conn->sock) { + spin_unlock_bh(&conn->session->frwd_lock); + return -ENOTCONN; + } + if (param == ISCSI_PARAM_LOCAL_PORT) + rc = kernel_getsockname(tcp_sw_conn->sock, + (struct sockaddr *)&addr); + else + rc = kernel_getpeername(tcp_sw_conn->sock, + (struct sockaddr *)&addr); + spin_unlock_bh(&conn->session->frwd_lock); + if (rc < 0) + return rc; + + return iscsi_conn_get_addr_param((struct sockaddr_storage *) + &addr, param, buf); + default: + return iscsi_conn_get_param(cls_conn, param, buf); + } + + return 0; +} + +static int iscsi_sw_tcp_host_get_param(struct Scsi_Host *shost, + enum iscsi_host_param param, char *buf) +{ + struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(shost); + struct iscsi_session *session = tcp_sw_host->session; + struct iscsi_conn *conn; + struct iscsi_tcp_conn *tcp_conn; + struct iscsi_sw_tcp_conn *tcp_sw_conn; + struct sockaddr_in6 addr; + int rc; + + switch (param) { + case ISCSI_HOST_PARAM_IPADDRESS: + if (!session) + return -ENOTCONN; + + spin_lock_bh(&session->frwd_lock); + conn = session->leadconn; + if (!conn) { + spin_unlock_bh(&session->frwd_lock); + return -ENOTCONN; + } + tcp_conn = conn->dd_data; + + tcp_sw_conn = tcp_conn->dd_data; + if (!tcp_sw_conn->sock) { + spin_unlock_bh(&session->frwd_lock); + return -ENOTCONN; + } + + rc = kernel_getsockname(tcp_sw_conn->sock, + (struct sockaddr *)&addr); + spin_unlock_bh(&session->frwd_lock); + if (rc < 0) + return rc; + + return iscsi_conn_get_addr_param((struct sockaddr_storage *) + &addr, + (enum iscsi_param)param, buf); + default: + return iscsi_host_get_param(shost, param, buf); + } + + return 0; +} + +static void +iscsi_sw_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn, + struct iscsi_stats *stats) +{ + struct iscsi_conn *conn = cls_conn->dd_data; + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; + struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data; + + stats->custom_length = 3; + strcpy(stats->custom[0].desc, "tx_sendpage_failures"); + stats->custom[0].value = tcp_sw_conn->sendpage_failures_cnt; + strcpy(stats->custom[1].desc, "rx_discontiguous_hdr"); + stats->custom[1].value = tcp_sw_conn->discontiguous_hdr_cnt; + strcpy(stats->custom[2].desc, "eh_abort_cnt"); + stats->custom[2].value = conn->eh_abort_cnt; + + iscsi_tcp_conn_get_stats(cls_conn, stats); +} + +static struct iscsi_cls_session * +iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max, + uint16_t qdepth, uint32_t initial_cmdsn) +{ + struct iscsi_cls_session *cls_session; + struct iscsi_session *session; + struct iscsi_sw_tcp_host *tcp_sw_host; + struct Scsi_Host *shost; + + if (ep) { + printk(KERN_ERR "iscsi_tcp: invalid ep %p.\n", ep); + return NULL; + } + + shost = iscsi_host_alloc(&iscsi_sw_tcp_sht, + sizeof(struct iscsi_sw_tcp_host), 1); + if (!shost) + return NULL; + shost->transportt = iscsi_sw_tcp_scsi_transport; + shost->cmd_per_lun = qdepth; + shost->max_lun = iscsi_max_lun; + shost->max_id = 0; + shost->max_channel = 0; + shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE; + + if (iscsi_host_add(shost, NULL)) + goto free_host; + + cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost, + cmds_max, 0, + sizeof(struct iscsi_tcp_task) + + sizeof(struct iscsi_sw_tcp_hdrbuf), + initial_cmdsn, 0); + if (!cls_session) + goto remove_host; + session = cls_session->dd_data; + tcp_sw_host = iscsi_host_priv(shost); + tcp_sw_host->session = session; + + shost->can_queue = session->scsi_cmds_max; + if (iscsi_tcp_r2tpool_alloc(session)) + goto remove_session; + return cls_session; + +remove_session: + iscsi_session_teardown(cls_session); +remove_host: + iscsi_host_remove(shost); +free_host: + iscsi_host_free(shost); + return NULL; +} + +static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session) +{ + struct Scsi_Host *shost = iscsi_session_to_shost(cls_session); + struct iscsi_session *session = cls_session->dd_data; + + if (WARN_ON_ONCE(session->leadconn)) + return; + + iscsi_tcp_r2tpool_free(cls_session->dd_data); + iscsi_session_teardown(cls_session); + + iscsi_host_remove(shost); + iscsi_host_free(shost); +} + +static umode_t iscsi_sw_tcp_attr_is_visible(int param_type, int param) +{ + switch (param_type) { + case ISCSI_HOST_PARAM: + switch (param) { + case ISCSI_HOST_PARAM_NETDEV_NAME: + case ISCSI_HOST_PARAM_HWADDRESS: + case ISCSI_HOST_PARAM_IPADDRESS: + case ISCSI_HOST_PARAM_INITIATOR_NAME: + return S_IRUGO; + default: + return 0; + } + case ISCSI_PARAM: + switch (param) { + case ISCSI_PARAM_MAX_RECV_DLENGTH: + case ISCSI_PARAM_MAX_XMIT_DLENGTH: + case ISCSI_PARAM_HDRDGST_EN: + case ISCSI_PARAM_DATADGST_EN: + case ISCSI_PARAM_CONN_ADDRESS: + case ISCSI_PARAM_CONN_PORT: + case ISCSI_PARAM_LOCAL_PORT: + case ISCSI_PARAM_EXP_STATSN: + case ISCSI_PARAM_PERSISTENT_ADDRESS: + case ISCSI_PARAM_PERSISTENT_PORT: + case ISCSI_PARAM_PING_TMO: + case ISCSI_PARAM_RECV_TMO: + case ISCSI_PARAM_INITIAL_R2T_EN: + case ISCSI_PARAM_MAX_R2T: + case ISCSI_PARAM_IMM_DATA_EN: + case ISCSI_PARAM_FIRST_BURST: + case ISCSI_PARAM_MAX_BURST: + case ISCSI_PARAM_PDU_INORDER_EN: + case ISCSI_PARAM_DATASEQ_INORDER_EN: + case ISCSI_PARAM_ERL: + case ISCSI_PARAM_TARGET_NAME: + case ISCSI_PARAM_TPGT: + case ISCSI_PARAM_USERNAME: + case ISCSI_PARAM_PASSWORD: + case ISCSI_PARAM_USERNAME_IN: + case ISCSI_PARAM_PASSWORD_IN: + case ISCSI_PARAM_FAST_ABORT: + case ISCSI_PARAM_ABORT_TMO: + case ISCSI_PARAM_LU_RESET_TMO: + case ISCSI_PARAM_TGT_RESET_TMO: + case ISCSI_PARAM_IFACE_NAME: + case ISCSI_PARAM_INITIATOR_NAME: + return S_IRUGO; + default: + return 0; + } + } + + return 0; +} + +static int iscsi_sw_tcp_slave_alloc(struct scsi_device *sdev) +{ + blk_queue_flag_set(QUEUE_FLAG_BIDI, sdev->request_queue); + return 0; +} + +static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev) +{ + struct iscsi_sw_tcp_host *tcp_sw_host = iscsi_host_priv(sdev->host); + struct iscsi_session *session = tcp_sw_host->session; + struct iscsi_conn *conn = session->leadconn; + + if (conn->datadgst_en) + sdev->request_queue->backing_dev_info->capabilities + |= BDI_CAP_STABLE_WRITES; + blk_queue_dma_alignment(sdev->request_queue, 0); + return 0; +} + +static struct scsi_host_template iscsi_sw_tcp_sht = { + .module = THIS_MODULE, + .name = "iSCSI Initiator over TCP/IP", + .queuecommand = iscsi_queuecommand, + .change_queue_depth = scsi_change_queue_depth, + .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1, + .sg_tablesize = 4096, + .max_sectors = 0xFFFF, + .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN, + .eh_timed_out = iscsi_eh_cmd_timed_out, + .eh_abort_handler = iscsi_eh_abort, + .eh_device_reset_handler= iscsi_eh_device_reset, + .eh_target_reset_handler = iscsi_eh_recover_target, + .use_clustering = DISABLE_CLUSTERING, + .slave_alloc = iscsi_sw_tcp_slave_alloc, + .slave_configure = iscsi_sw_tcp_slave_configure, + .target_alloc = iscsi_target_alloc, + .proc_name = "iscsi_tcp", + .this_id = -1, + .track_queue_depth = 1, +}; + +static struct iscsi_transport iscsi_sw_tcp_transport = { + .owner = THIS_MODULE, + .name = "tcp", + .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST + | CAP_DATADGST, + /* session management */ + .create_session = iscsi_sw_tcp_session_create, + .destroy_session = iscsi_sw_tcp_session_destroy, + /* connection management */ + .create_conn = iscsi_sw_tcp_conn_create, + .bind_conn = iscsi_sw_tcp_conn_bind, + .destroy_conn = iscsi_sw_tcp_conn_destroy, + .attr_is_visible = iscsi_sw_tcp_attr_is_visible, + .set_param = iscsi_sw_tcp_conn_set_param, + .get_conn_param = iscsi_sw_tcp_conn_get_param, + .get_session_param = iscsi_session_get_param, + .start_conn = iscsi_conn_start, + .stop_conn = iscsi_sw_tcp_conn_stop, + /* iscsi host params */ + .get_host_param = iscsi_sw_tcp_host_get_param, + .set_host_param = iscsi_host_set_param, + /* IO */ + .send_pdu = iscsi_conn_send_pdu, + .get_stats = iscsi_sw_tcp_conn_get_stats, + /* iscsi task/cmd helpers */ + .init_task = iscsi_tcp_task_init, + .xmit_task = iscsi_tcp_task_xmit, + .cleanup_task = iscsi_tcp_cleanup_task, + /* low level pdu helpers */ + .xmit_pdu = iscsi_sw_tcp_pdu_xmit, + .init_pdu = iscsi_sw_tcp_pdu_init, + .alloc_pdu = iscsi_sw_tcp_pdu_alloc, + /* recovery */ + .session_recovery_timedout = iscsi_session_recovery_timedout, +}; + +static int __init iscsi_sw_tcp_init(void) +{ + if (iscsi_max_lun < 1) { + printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n", + iscsi_max_lun); + return -EINVAL; + } + + iscsi_sw_tcp_scsi_transport = iscsi_register_transport( + &iscsi_sw_tcp_transport); + if (!iscsi_sw_tcp_scsi_transport) + return -ENODEV; + + return 0; +} + +static void __exit iscsi_sw_tcp_exit(void) +{ + iscsi_unregister_transport(&iscsi_sw_tcp_transport); +} + +module_init(iscsi_sw_tcp_init); +module_exit(iscsi_sw_tcp_exit); |