/**
* iscsi_sendpage - send one page of iSCSI Data-Out.
* @conn: iscsi connection
* @buf: buffer to write from
* @count: remaining data
* @sent: number of bytes sent
*
* Notes:
* (Tx, Fast Path)
**/
inline int iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
int *count, int *sent)
{
int flags = 0; /* MSG_DONTWAIT; */
int res, size;
size = buf->sg.length - buf->sent;
BUG_ON(buf->sent + size > buf->sg.length);
if (size > *count)
size = *count;
if (buf->sent + size != buf->sg.length || *count != size)
flags |= MSG_MORE;
res = iscsi_send(conn, buf, size, flags);
debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
size, buf->sent, *count, *sent, res);
if (res >= 0) {
*count -= res;
*sent += res;
if (size != res)
return -EAGAIN;
return 0;
}
return res;
}
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;
struct iscsi_session *session;
void (*old_state_change)(struct sock *);
read_lock(&sk->sk_callback_lock);
conn = (struct iscsi_conn*)sk->sk_user_data;
session = conn->session;
if ((sk->sk_state == TCP_CLOSE_WAIT ||
sk->sk_state == TCP_CLOSE) &&
!atomic_read(&sk->sk_rmem_alloc)) {
debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n");
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
}
tcp_conn = conn->dd_data;
tcp_sw_conn = tcp_conn->dd_data;
old_state_change = tcp_sw_conn->old_state_change;
read_unlock(&sk->sk_callback_lock);
old_state_change(sk);
}
/**
* iscsi_tcp_copy - copy skb bits to the destanation buffer
* @conn: iscsi tcp connection
*
* Notes:
* The function calls skb_copy_bits() and updates per-connection
* byte counters.
**/
inline int iscsi_tcp_copy(struct iscsi_tcp_conn *tcp_conn)
{
void *buf = tcp_conn->data;
int buf_size = tcp_conn->in.datalen;
int buf_left = buf_size - tcp_conn->data_copied;
int size = min(tcp_conn->in.copy, buf_left);
int rc;
debug_tcp("tcp_copy %d bytes at offset %d copied %d\n",
size, tcp_conn->in.offset, tcp_conn->data_copied);
BUG_ON(size <= 0);
rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
(char*)buf + tcp_conn->data_copied, size);
BUG_ON(rc);
tcp_conn->in.offset += size;
tcp_conn->in.copy -= size;
tcp_conn->in.copied += size;
tcp_conn->data_copied += size;
if (buf_size != tcp_conn->data_copied)
return -EAGAIN;
return 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;
debug_tcp("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);
debug_tcp("read %d bytes status %d\n", skb->len - offset, status);
return total_consumed;
}
/**
* 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_conn*)sk->sk_user_data;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct iscsi_sw_tcp_conn *tcp_sw_conn = tcp_conn->dd_data;
tcp_sw_conn->old_write_space(sk);
debug_tcp("iscsi_write_space: cid %d\n", conn->id);
scsi_queue_work(conn->session->host, &conn->xmitwork);
}
/**
* iscsi_ctask_copy - copy skb bits to the destanation cmd task
* @conn: iscsi tcp connection
* @ctask: scsi command task
* @buf: buffer to copy to
* @buf_size: size of buffer
* @offset: offset within the buffer
*
* Notes:
* The function calls skb_copy_bits() and updates per-connection and
* per-cmd byte counters.
*
* Read counters (in bytes):
*
* conn->in.offset offset within in progress SKB
* conn->in.copy left to copy from in progress SKB
* including padding
* conn->in.copied copied already from in progress SKB
* conn->data_copied copied already from in progress buffer
* ctask->sent total bytes sent up to the MidLayer
* ctask->data_count left to copy from in progress Data-In
* buf_left left to copy from in progress buffer
**/
static inline int
iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
void *buf, int buf_size, int offset)
{
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
int buf_left = buf_size - (tcp_conn->data_copied + offset);
int size = min(tcp_conn->in.copy, buf_left);
int rc;
size = min(size, ctask->data_count);
debug_tcp("ctask_copy %d bytes at offset %d copied %d\n",
size, tcp_conn->in.offset, tcp_conn->in.copied);
BUG_ON(size <= 0);
BUG_ON(tcp_ctask->sent + size > ctask->total_length);
rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
(char*)buf + (offset + tcp_conn->data_copied), size);
/* must fit into skb->len */
BUG_ON(rc);
tcp_conn->in.offset += size;
tcp_conn->in.copy -= size;
tcp_conn->in.copied += size;
tcp_conn->data_copied += size;
tcp_ctask->sent += size;
ctask->data_count -= size;
BUG_ON(tcp_conn->in.copy < 0);
BUG_ON(ctask->data_count < 0);
if (buf_size != (tcp_conn->data_copied + offset)) {
if (!ctask->data_count) {
BUG_ON(buf_size - tcp_conn->data_copied < 0);
/* done with this PDU */
return buf_size - tcp_conn->data_copied;
}
return -EAGAIN;
}
/* done with this buffer or with both - PDU and buffer */
tcp_conn->data_copied = 0;
return 0;
}
/**
* iscsi_sendhdr - send PDU Header via tcp_sendpage()
* @conn: iscsi connection
* @buf: buffer to write from
* @datalen: lenght of data to be sent after the header
*
* Notes:
* (Tx, Fast Path)
**/
inline int iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf,
int datalen)
{
int flags = 0; /* MSG_DONTWAIT; */
int res, size;
size = buf->sg.length - buf->sent;
BUG_ON(buf->sent + size > buf->sg.length);
if (buf->sent + size != buf->sg.length || datalen)
flags |= MSG_MORE;
res = iscsi_send(conn, buf, size, flags);
debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
if (res >= 0) {
if (size != res)
return -EAGAIN;
return 0;
}
return res;
}
/**
* 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);
if (copied || r == -EAGAIN)
break;
return r;
}
copied += r;
}
return copied;
}
/**
* iscsi_sw_tcp_xmit - TCP transmit
**/
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);
if (rc < 0) {
rc = ISCSI_ERR_XMIT_FAILED;
goto error;
}
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;
}
}
}
debug_tcp("xmit %d bytes\n", consumed);
conn->txdata_octets += consumed;
return consumed;
error:
/* Transmit error. We could initiate error recovery
* here. */
debug_tcp("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
*/
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;
int rc;
while (iscsi_sw_tcp_xmit_qlen(conn)) {
rc = iscsi_sw_tcp_xmit(conn);
if (rc == 0)
return -EAGAIN;
if (rc < 0)
return rc;
}
return 0;
}
/*
* 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;
debug_tcp("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;
debug_tcp("%s(%p%s)\n", __func__, tcp_conn,
conn->hdrdgst_en? ", digest enabled" : "");
/* 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 hash_desc *tx_hash = NULL;
unsigned int hdr_spec_len;
debug_tcp("%s(%p, offset=%d, datalen=%d%s)\n", __func__,
tcp_conn, offset, len,
conn->datadgst_en? ", digest enabled" : "");
/* 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 hash_desc *tx_hash = NULL;
unsigned int hdr_spec_len;
debug_tcp("%s(%p, datalen=%d%s)\n", __func__, tcp_conn, len,
conn->datadgst_en? ", digest enabled" : "");
/* 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) {
iscsi_conn_failure(conn, err);
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;
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;
tcp_sw_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
CRYPTO_ALG_ASYNC);
tcp_sw_conn->tx_hash.flags = 0;
if (IS_ERR(tcp_sw_conn->tx_hash.tfm))
goto free_conn;
tcp_sw_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0,
CRYPTO_ALG_ASYNC);
tcp_sw_conn->rx_hash.flags = 0;
if (IS_ERR(tcp_sw_conn->rx_hash.tfm))
goto free_tx_tfm;
tcp_conn->rx_hash = &tcp_sw_conn->rx_hash;
return cls_conn;
free_tx_tfm:
crypto_free_hash(tcp_sw_conn->tx_hash.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(tcp_sw_conn);
sock_put(sock->sk);
spin_lock_bh(&session->lock);
tcp_sw_conn->sock = NULL;
spin_unlock_bh(&session->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);
if (tcp_sw_conn->tx_hash.tfm)
crypto_free_hash(tcp_sw_conn->tx_hash.tfm);
if (tcp_sw_conn->rx_hash.tfm)
crypto_free_hash(tcp_sw_conn->rx_hash.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;
/* userspace may have goofed up and not bound us */
if (!tcp_sw_conn->sock)
return;
/*
* Make sure our recv side is stopped.
* Older tools called conn stop before ep_disconnect
* so IO could still be coming in.
*/
write_lock_bh(&tcp_sw_conn->sock->sk->sk_callback_lock);
set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
write_unlock_bh(&tcp_sw_conn->sock->sk->sk_callback_lock);
iscsi_conn_stop(cls_conn, flag);
iscsi_sw_tcp_release_conn(conn);
}
static int iscsi_sw_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock,
char *buf, int *port,
int (*getname)(struct socket *,
struct sockaddr *,
int *addrlen))
{
struct sockaddr_storage *addr;
struct sockaddr_in6 *sin6;
struct sockaddr_in *sin;
int rc = 0, len;
addr = kmalloc(sizeof(*addr), GFP_KERNEL);
if (!addr)
return -ENOMEM;
if (getname(sock, (struct sockaddr *) addr, &len)) {
rc = -ENODEV;
goto free_addr;
}
switch (addr->ss_family) {
case AF_INET:
sin = (struct sockaddr_in *)addr;
spin_lock_bh(&conn->session->lock);
sprintf(buf, "%pI4", &sin->sin_addr.s_addr);
*port = be16_to_cpu(sin->sin_port);
spin_unlock_bh(&conn->session->lock);
break;
case AF_INET6:
sin6 = (struct sockaddr_in6 *)addr;
spin_lock_bh(&conn->session->lock);
sprintf(buf, "%pI6", &sin6->sin6_addr);
*port = be16_to_cpu(sin6->sin6_port);
spin_unlock_bh(&conn->session->lock);
break;
}
free_addr:
kfree(addr);
return rc;
}
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 Scsi_Host *shost = iscsi_session_to_shost(cls_session);
struct iscsi_host *ihost = shost_priv(shost);
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;
}
/*
* copy these values now because if we drop the session
* userspace may still want to query the values since we will
* be using them for the reconnect
*/
err = iscsi_sw_tcp_get_addr(conn, sock, conn->portal_address,
&conn->portal_port, kernel_getpeername);
if (err)
goto free_socket;
err = iscsi_sw_tcp_get_addr(conn, sock, ihost->local_address,
&ihost->local_port, kernel_getsockname);
if (err)
goto free_socket;
err = iscsi_conn_bind(cls_session, cls_conn, is_leading);
if (err)
goto free_socket;
/* bind iSCSI connection and socket */
tcp_sw_conn->sock = sock;
/* setup Socket parameters */
sk = sock->sk;
sk->sk_reuse = 1;
sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */
sk->sk_allocation = GFP_ATOMIC;
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_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;
int value;
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:
sscanf(buf, "%d", &value);
if (value <= 0 || !is_power_of_2(value))
return -EINVAL;
if (session->max_r2t == value)
break;
iscsi_tcp_r2tpool_free(session);
iscsi_set_param(cls_conn, param, buf, buflen);
if (iscsi_tcp_r2tpool_alloc(session))
return -ENOMEM;
break;
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;
int len;
switch(param) {
case ISCSI_PARAM_CONN_PORT:
spin_lock_bh(&conn->session->lock);
len = sprintf(buf, "%hu\n", conn->portal_port);
spin_unlock_bh(&conn->session->lock);
break;
case ISCSI_PARAM_CONN_ADDRESS:
spin_lock_bh(&conn->session->lock);
len = sprintf(buf, "%s\n", conn->portal_address);
spin_unlock_bh(&conn->session->lock);
break;
default:
return iscsi_conn_get_param(cls_conn, param, buf);
}
return len;
}
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,
uint32_t *hostno)
{
struct iscsi_cls_session *cls_session;
struct iscsi_session *session;
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, 0, qdepth);
if (!shost)
return NULL;
shost->transportt = iscsi_sw_tcp_scsi_transport;
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;
*hostno = shost->host_no;
cls_session = iscsi_session_setup(&iscsi_sw_tcp_transport, shost,
cmds_max,
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;
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);
iscsi_tcp_r2tpool_free(cls_session->dd_data);
iscsi_session_teardown(cls_session);
iscsi_host_remove(shost);
iscsi_host_free(shost);
}
static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
{
blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY);
blk_queue_dma_alignment(sdev->request_queue, 0);
return 0;
}
/**
* iscsi_tcp_data_recv - TCP receive in sendfile fashion
* @rd_desc: read descriptor
* @skb: socket buffer
* @offset: offset in skb
* @len: skb->len - offset
**/
static int
iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
unsigned int offset, size_t len)
{
int rc;
struct iscsi_conn *conn = rd_desc->arg.data;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
int processed;
char pad[ISCSI_PAD_LEN];
struct scatterlist sg;
/*
* Save current SKB and its offset in the corresponding
* connection context.
*/
tcp_conn->in.copy = skb->len - offset;
tcp_conn->in.offset = offset;
tcp_conn->in.skb = skb;
tcp_conn->in.len = tcp_conn->in.copy;
BUG_ON(tcp_conn->in.copy <= 0);
debug_tcp("in %d bytes\n", tcp_conn->in.copy);
more:
tcp_conn->in.copied = 0;
rc = 0;
if (unlikely(conn->suspend_rx)) {
debug_tcp("conn %d Rx suspended!\n", conn->id);
return 0;
}
if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER ||
tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) {
rc = iscsi_hdr_extract(tcp_conn);
if (rc) {
if (rc == -EAGAIN)
goto nomore;
else {
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
return 0;
}
}
/*
* Verify and process incoming PDU header.
*/
rc = tcp_conn->ops->hdr_recv(conn);
if (!rc && tcp_conn->in.datalen) {
if (conn->datadgst_en) {
BUG_ON(!tcp_conn->data_rx_tfm);
crypto_digest_init(tcp_conn->data_rx_tfm);
}
tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
} else if (rc) {
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
return 0;
}
}
if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV) {
uint32_t recv_digest;
debug_tcp("extra data_recv offset %d copy %d\n",
tcp_conn->in.offset, tcp_conn->in.copy);
skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
&recv_digest, 4);
tcp_conn->in.offset += 4;
tcp_conn->in.copy -= 4;
if (recv_digest != tcp_conn->in.datadgst) {
debug_tcp("iscsi_tcp: data digest error!"
"0x%x != 0x%x\n", recv_digest,
tcp_conn->in.datadgst);
iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST);
return 0;
} else {
debug_tcp("iscsi_tcp: data digest match!"
"0x%x == 0x%x\n", recv_digest,
tcp_conn->in.datadgst);
tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
}
}
if (unlikely(conn->suspend_rx)) {
debug_tcp("conn %d Rx suspended!\n", conn->id);
goto nomore;
}
if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV &&
tcp_conn->in.copy) {
debug_tcp("data_recv offset %d copy %d\n",
tcp_conn->in.offset, tcp_conn->in.copy);
rc = tcp_conn->ops->data_recv(conn);
if (rc) {
if (rc == -EAGAIN)
goto again;
iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
return 0;
}
tcp_conn->in.copy -= tcp_conn->in.padding;
tcp_conn->in.offset += tcp_conn->in.padding;
if (conn->datadgst_en) {
if (tcp_conn->in.padding) {
debug_tcp("padding -> %d\n",
tcp_conn->in.padding);
memset(pad, 0, tcp_conn->in.padding);
sg_init_one(&sg, pad, tcp_conn->in.padding);
crypto_digest_update(tcp_conn->data_rx_tfm,
&sg, 1);
}
crypto_digest_final(tcp_conn->data_rx_tfm,
(u8 *) & tcp_conn->in.datadgst);
debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
} else
tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
}
debug_tcp("f, processed %d from out of %d padding %d\n",
tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding);
BUG_ON(tcp_conn->in.offset - offset > len);
if (tcp_conn->in.offset - offset != len) {
debug_tcp("continue to process %d bytes\n",
(int)len - (tcp_conn->in.offset - offset));
goto more;
}
nomore:
processed = tcp_conn->in.offset - offset;
BUG_ON(processed == 0);
return processed;
again:
processed = tcp_conn->in.offset - offset;
debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n",
processed, (int)len, (int)rd_desc->count);
BUG_ON(processed == 0);
BUG_ON(processed > len);
conn->rxdata_octets += processed;
return processed;
}
static inline int
iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
{
struct sk_buff *skb = tcp_conn->in.skb;
tcp_conn->in.zero_copy_hdr = 0;
if (tcp_conn->in.copy >= tcp_conn->hdr_size &&
tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) {
/*
* Zero-copy PDU Header: using connection context
* to store header pointer.
*/
if (skb_shinfo(skb)->frag_list == NULL &&
!skb_shinfo(skb)->nr_frags) {
tcp_conn->in.hdr = (struct iscsi_hdr *)
((char*)skb->data + tcp_conn->in.offset);
tcp_conn->in.zero_copy_hdr = 1;
} else {
/* ignoring return code since we checked
* in.copy before */
skb_copy_bits(skb, tcp_conn->in.offset,
&tcp_conn->hdr, tcp_conn->hdr_size);
tcp_conn->in.hdr = &tcp_conn->hdr;
}
tcp_conn->in.offset += tcp_conn->hdr_size;
tcp_conn->in.copy -= tcp_conn->hdr_size;
} else {
int hdr_remains;
int copylen;
/*
* PDU header scattered across SKB's,
* copying it... This'll happen quite rarely.
*/
if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
tcp_conn->in.hdr_offset = 0;
hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
BUG_ON(hdr_remains <= 0);
copylen = min(tcp_conn->in.copy, hdr_remains);
skb_copy_bits(skb, tcp_conn->in.offset,
(char*)&tcp_conn->hdr + tcp_conn->in.hdr_offset,
copylen);
debug_tcp("PDU gather offset %d bytes %d in.offset %d "
"in.copy %d\n", tcp_conn->in.hdr_offset, copylen,
tcp_conn->in.offset, tcp_conn->in.copy);
tcp_conn->in.offset += copylen;
tcp_conn->in.copy -= copylen;
if (copylen < hdr_remains) {
tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER;
tcp_conn->in.hdr_offset += copylen;
return -EAGAIN;
}
tcp_conn->in.hdr = &tcp_conn->hdr;
tcp_conn->discontiguous_hdr_cnt++;
tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
}
return 0;
}
