"Alex Aizman <itn780@yahoo.com>");
MODULE_DESCRIPTION("iSCSI/TCP data-path");
MODULE_LICENSE("GPL");
-/* #define DEBUG_TCP */
+#undef DEBUG_TCP
#define DEBUG_ASSERT
#ifdef DEBUG_TCP
static unsigned int iscsi_max_lun = 512;
module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
+static int iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn,
+ struct iscsi_chunk *chunk);
+
static inline void
iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size)
{
- sg_init_one(&ibuf->sg, vbuf, size);
+ ibuf->sg.page = virt_to_page(vbuf);
+ ibuf->sg.offset = offset_in_page(vbuf);
+ ibuf->sg.length = size;
ibuf->sent = 0;
ibuf->use_sendmsg = 1;
}
static inline void
iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg)
{
- sg_init_table(&ibuf->sg, 1);
- sg_set_page(&ibuf->sg, sg_page(sg), sg->length, sg->offset);
+ ibuf->sg.page = sg->page;
+ ibuf->sg.offset = sg->offset;
+ ibuf->sg.length = sg->length;
/*
* Fastpath: sg element fits into single page
*/
- if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg_page(sg)))
+ if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg->page))
ibuf->use_sendmsg = 0;
else
ibuf->use_sendmsg = 1;
buf->sg.length += sizeof(u32);
}
+/*
+ * Scatterlist handling: inside the iscsi_chunk, we
+ * remember an index into the scatterlist, and set data/size
+ * to the current scatterlist entry. For highmem pages, we
+ * kmap as needed.
+ *
+ * Note that the page is unmapped when we return from
+ * TCP's data_ready handler, so we may end up mapping and
+ * unmapping the same page repeatedly. The whole reason
+ * for this is that we shouldn't keep the page mapped
+ * outside the softirq.
+ */
+
+/**
+ * iscsi_tcp_chunk_init_sg - init indicated scatterlist entry
+ * @chunk: the buffer object
+ * @idx: index into scatterlist
+ * @offset: byte offset into that sg entry
+ *
+ * This function sets up the chunk so that subsequent
+ * data is copied to the indicated sg entry, at the given
+ * offset.
+ */
+static inline void
+iscsi_tcp_chunk_init_sg(struct iscsi_chunk *chunk,
+ unsigned int idx, unsigned int offset)
+{
+ struct scatterlist *sg;
+
+ BUG_ON(chunk->sg == NULL);
+
+ sg = &chunk->sg[idx];
+ chunk->sg_index = idx;
+ chunk->sg_offset = offset;
+ chunk->size = min(sg->length - offset, chunk->total_size);
+ chunk->data = NULL;
+}
+
+/**
+ * iscsi_tcp_chunk_map - map the current S/G page
+ * @chunk: iscsi chunk
+ *
+ * We only need to possibly kmap data if scatter lists are being used,
+ * because the iscsi passthrough and internal IO paths will never use high
+ * mem pages.
+ */
+static inline void
+iscsi_tcp_chunk_map(struct iscsi_chunk *chunk)
+{
+ struct scatterlist *sg;
+
+ if (chunk->data != NULL || !chunk->sg)
+ return;
+
+ sg = &chunk->sg[chunk->sg_index];
+ BUG_ON(chunk->sg_mapped);
+ BUG_ON(sg->length == 0);
+ chunk->sg_mapped = kmap_atomic(sg->page, KM_SOFTIRQ0);
+ chunk->data = chunk->sg_mapped + sg->offset + chunk->sg_offset;
+}
+
+static inline void
+iscsi_tcp_chunk_unmap(struct iscsi_chunk *chunk)
+{
+ if (chunk->sg_mapped) {
+ kunmap_atomic(chunk->sg_mapped, KM_SOFTIRQ0);
+ chunk->sg_mapped = NULL;
+ chunk->data = NULL;
+ }
+}
+
+/*
+ * Splice the digest buffer into the buffer
+ */
+static inline void
+iscsi_tcp_chunk_splice_digest(struct iscsi_chunk *chunk, void *digest)
+{
+ chunk->data = digest;
+ chunk->digest_len = ISCSI_DIGEST_SIZE;
+ chunk->total_size += ISCSI_DIGEST_SIZE;
+ chunk->size = ISCSI_DIGEST_SIZE;
+ chunk->copied = 0;
+ chunk->sg = NULL;
+ chunk->sg_index = 0;
+ chunk->hash = NULL;
+}
+
+/**
+ * iscsi_tcp_chunk_done - check whether the chunk is complete
+ * @chunk: iscsi chunk to check
+ *
+ * Check if we're done receiving this chunk. If the receive
+ * buffer is full but we expect more data, move on to the
+ * next entry in the scatterlist.
+ *
+ * If the amount of data we received isn't a multiple of 4,
+ * we will transparently receive the pad bytes, too.
+ *
+ * This function must be re-entrant.
+ */
static inline int
-iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn)
+iscsi_tcp_chunk_done(struct iscsi_chunk *chunk)
{
- struct sk_buff *skb = tcp_conn->in.skb;
+ static unsigned char padbuf[ISCSI_PAD_LEN];
+
+ if (chunk->copied < chunk->size) {
+ iscsi_tcp_chunk_map(chunk);
+ return 0;
+ }
- tcp_conn->in.zero_copy_hdr = 0;
+ chunk->total_copied += chunk->copied;
+ chunk->copied = 0;
+ chunk->size = 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;
+ /* Unmap the current scatterlist page, if there is one. */
+ iscsi_tcp_chunk_unmap(chunk);
+
+ /* Do we have more scatterlist entries? */
+ if (chunk->total_copied < chunk->total_size) {
+ /* Proceed to the next entry in the scatterlist. */
+ iscsi_tcp_chunk_init_sg(chunk, chunk->sg_index + 1, 0);
+ iscsi_tcp_chunk_map(chunk);
+ BUG_ON(chunk->size == 0);
+ return 0;
+ }
+
+ /* Do we need to handle padding? */
+ if (chunk->total_copied & (ISCSI_PAD_LEN-1)) {
+ unsigned int pad;
+
+ pad = ISCSI_PAD_LEN - (chunk->total_copied & (ISCSI_PAD_LEN-1));
+ debug_tcp("consume %d pad bytes\n", pad);
+ chunk->total_size += pad;
+ chunk->size = pad;
+ chunk->data = padbuf;
+ return 0;
+ }
+
+ /*
+ * Set us up for receiving the data digest. hdr digest
+ * is completely handled in hdr done function.
+ */
+ if (chunk->hash) {
+ if (chunk->digest_len == 0) {
+ crypto_hash_final(chunk->hash, chunk->digest);
+ iscsi_tcp_chunk_splice_digest(chunk,
+ chunk->recv_digest);
+ return 0;
}
- 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.
- */
+ return 1;
+}
+
+/**
+ * iscsi_tcp_chunk_recv - copy data to chunk
+ * @tcp_conn: the iSCSI TCP connection
+ * @chunk: the buffer to copy to
+ * @ptr: data pointer
+ * @len: amount of data available
+ *
+ * This function copies up to @len bytes to the
+ * given buffer, and returns the number of bytes
+ * consumed, which can actually be less than @len.
+ *
+ * If hash digest is enabled, the function will update the
+ * hash while copying.
+ * Combining these two operations doesn't buy us a lot (yet),
+ * but in the future we could implement combined copy+crc,
+ * just way we do for network layer checksums.
+ */
+static int
+iscsi_tcp_chunk_recv(struct iscsi_tcp_conn *tcp_conn,
+ struct iscsi_chunk *chunk, const void *ptr,
+ unsigned int len)
+{
+ struct scatterlist sg;
+ unsigned int copy, copied = 0;
+
+ while (!iscsi_tcp_chunk_done(chunk)) {
+ if (copied == len)
+ goto out;
+
+ copy = min(len - copied, chunk->size - chunk->copied);
+ memcpy(chunk->data + chunk->copied, ptr + copied, copy);
+
+ if (chunk->hash) {
+ sg_init_one(&sg, ptr + copied, copy);
+ crypto_hash_update(chunk->hash, &sg, copy);
+ }
+ chunk->copied += copy;
+ copied += copy;
+ }
+
+out:
+ return copied;
+}
- if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER)
- tcp_conn->in.hdr_offset = 0;
+static inline void
+iscsi_tcp_dgst_header(struct hash_desc *hash, const void *hdr, size_t hdrlen,
+ unsigned char digest[ISCSI_DIGEST_SIZE])
+{
+ struct scatterlist sg;
+
+ sg_init_one(&sg, hdr, hdrlen);
+ crypto_hash_digest(hash, &sg, hdrlen, digest);
+}
+
+static inline int
+iscsi_tcp_dgst_verify(struct iscsi_tcp_conn *tcp_conn,
+ struct iscsi_chunk *chunk)
+{
+ if (!chunk->digest_len)
+ return 1;
+
+ if (memcmp(chunk->recv_digest, chunk->digest, chunk->digest_len)) {
+ debug_scsi("digest mismatch\n");
+ return 0;
+ }
- hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset;
- BUG_ON(hdr_remains <= 0);
+ return 1;
+}
- 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);
+/*
+ * Helper function to set up chunk buffer
+ */
+static inline void
+__iscsi_chunk_init(struct iscsi_chunk *chunk, size_t size,
+ iscsi_chunk_done_fn_t *done, struct hash_desc *hash)
+{
+ memset(chunk, 0, sizeof(*chunk));
+ chunk->total_size = size;
+ chunk->done = done;
- 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);
+ if (hash) {
+ chunk->hash = hash;
+ crypto_hash_init(hash);
+ }
+}
- 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;
+static inline void
+iscsi_chunk_init_linear(struct iscsi_chunk *chunk, void *data, size_t size,
+ iscsi_chunk_done_fn_t *done, struct hash_desc *hash)
+{
+ __iscsi_chunk_init(chunk, size, done, hash);
+ chunk->data = data;
+ chunk->size = size;
+}
+
+static inline int
+iscsi_chunk_seek_sg(struct iscsi_chunk *chunk,
+ struct scatterlist *sg, unsigned int sg_count,
+ unsigned int offset, size_t size,
+ iscsi_chunk_done_fn_t *done, struct hash_desc *hash)
+{
+ unsigned int i;
+
+ __iscsi_chunk_init(chunk, size, done, hash);
+ for (i = 0; i < sg_count; ++i) {
+ if (offset < sg[i].length) {
+ chunk->sg = sg;
+ chunk->sg_count = sg_count;
+ iscsi_tcp_chunk_init_sg(chunk, i, offset);
+ return 0;
}
- tcp_conn->in.hdr = &tcp_conn->hdr;
- tcp_conn->discontiguous_hdr_cnt++;
- tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
+ offset -= sg[i].length;
}
+ return ISCSI_ERR_DATA_OFFSET;
+}
+
+/**
+ * iscsi_tcp_hdr_recv_prep - prep chunk for hdr reception
+ * @tcp_conn: iscsi connection to prep for
+ *
+ * This function always passes NULL for the hash argument, because when this
+ * function is called we do not yet know the final size of the header and want
+ * to delay the digest processing until we know that.
+ */
+static void
+iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn)
+{
+ debug_tcp("iscsi_tcp_hdr_recv_prep(%p%s)\n", tcp_conn,
+ tcp_conn->iscsi_conn->hdrdgst_en ? ", digest enabled" : "");
+ iscsi_chunk_init_linear(&tcp_conn->in.chunk,
+ tcp_conn->in.hdr_buf, sizeof(struct iscsi_hdr),
+ iscsi_tcp_hdr_recv_done, NULL);
+}
+
+/*
+ * Handle incoming reply to any other type of command
+ */
+static int
+iscsi_tcp_data_recv_done(struct iscsi_tcp_conn *tcp_conn,
+ struct iscsi_chunk *chunk)
+{
+ struct iscsi_conn *conn = tcp_conn->iscsi_conn;
+ int rc = 0;
+
+ if (!iscsi_tcp_dgst_verify(tcp_conn, chunk))
+ return ISCSI_ERR_DATA_DGST;
+
+ rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr,
+ conn->data, tcp_conn->in.datalen);
+ if (rc)
+ return rc;
+
+ iscsi_tcp_hdr_recv_prep(tcp_conn);
return 0;
}
+static void
+iscsi_tcp_data_recv_prep(struct iscsi_tcp_conn *tcp_conn)
+{
+ struct iscsi_conn *conn = tcp_conn->iscsi_conn;
+ struct hash_desc *rx_hash = NULL;
+
+ if (conn->datadgst_en)
+ rx_hash = &tcp_conn->rx_hash;
+
+ iscsi_chunk_init_linear(&tcp_conn->in.chunk,
+ conn->data, tcp_conn->in.datalen,
+ iscsi_tcp_data_recv_done, rx_hash);
+}
+
/*
* must be called with session lock
*/
return 0;
}
+/*
+ * Handle incoming reply to DataIn command
+ */
static int
-iscsi_tcp_hdr_recv(struct iscsi_conn *conn)
+iscsi_tcp_process_data_in(struct iscsi_tcp_conn *tcp_conn,
+ struct iscsi_chunk *chunk)
+{
+ struct iscsi_conn *conn = tcp_conn->iscsi_conn;
+ struct iscsi_hdr *hdr = tcp_conn->in.hdr;
+ int rc;
+
+ if (!iscsi_tcp_dgst_verify(tcp_conn, chunk))
+ return ISCSI_ERR_DATA_DGST;
+
+ /* check for non-exceptional status */
+ if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
+ rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
+ if (rc)
+ return rc;
+ }
+
+ iscsi_tcp_hdr_recv_prep(tcp_conn);
+ return 0;
+}
+
+/**
+ * iscsi_tcp_hdr_dissect - process PDU header
+ * @conn: iSCSI connection
+ * @hdr: PDU header
+ *
+ * This function analyzes the header of the PDU received,
+ * and performs several sanity checks. If the PDU is accompanied
+ * by data, the receive buffer is set up to copy the incoming data
+ * to the correct location.
+ */
+static int
+iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
{
int rc = 0, opcode, ahslen;
- struct iscsi_hdr *hdr;
struct iscsi_session *session = conn->session;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
- uint32_t cdgst, rdgst = 0, itt;
-
- hdr = tcp_conn->in.hdr;
+ struct iscsi_cmd_task *ctask;
+ uint32_t itt;
/* verify PDU length */
tcp_conn->in.datalen = ntoh24(hdr->dlength);
tcp_conn->in.datalen, conn->max_recv_dlength);
return ISCSI_ERR_DATALEN;
}
- tcp_conn->data_copied = 0;
- /* read AHS */
+ /* Additional header segments. So far, we don't
+ * process additional headers.
+ */
ahslen = hdr->hlength << 2;
- tcp_conn->in.offset += ahslen;
- tcp_conn->in.copy -= ahslen;
- if (tcp_conn->in.copy < 0) {
- printk(KERN_ERR "iscsi_tcp: can't handle AHS with length "
- "%d bytes\n", ahslen);
- return ISCSI_ERR_AHSLEN;
- }
-
- /* calculate read padding */
- tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1);
- if (tcp_conn->in.padding) {
- tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding;
- debug_scsi("read padding %d bytes\n", tcp_conn->in.padding);
- }
-
- if (conn->hdrdgst_en) {
- struct scatterlist sg;
-
- sg_init_one(&sg, (u8 *)hdr,
- sizeof(struct iscsi_hdr) + ahslen);
- crypto_hash_digest(&tcp_conn->rx_hash, &sg, sg.length,
- (u8 *)&cdgst);
- rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) +
- ahslen);
- if (cdgst != rdgst) {
- printk(KERN_ERR "iscsi_tcp: hdrdgst error "
- "recv 0x%x calc 0x%x\n", rdgst, cdgst);
- return ISCSI_ERR_HDR_DGST;
- }
- }
opcode = hdr->opcode & ISCSI_OPCODE_MASK;
/* verify itt (itt encoding: age+cid+itt) */
rc = iscsi_verify_itt(conn, hdr, &itt);
if (rc == ISCSI_ERR_NO_SCSI_CMD) {
+ /* XXX: what does this do? */
tcp_conn->in.datalen = 0; /* force drop */
return 0;
} else if (rc)
return rc;
- debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n",
- opcode, tcp_conn->in.offset, tcp_conn->in.copy,
- ahslen, tcp_conn->in.datalen);
+ debug_tcp("opcode 0x%x ahslen %d datalen %d\n",
+ opcode, ahslen, tcp_conn->in.datalen);
switch(opcode) {
case ISCSI_OP_SCSI_DATA_IN:
- tcp_conn->in.ctask = session->cmds[itt];
- rc = iscsi_data_rsp(conn, tcp_conn->in.ctask);
+ ctask = session->cmds[itt];
+ rc = iscsi_data_rsp(conn, ctask);
if (rc)
return rc;
+ if (tcp_conn->in.datalen) {
+ struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
+ struct hash_desc *rx_hash = NULL;
+
+ /*
+ * Setup copy of Data-In into the Scsi_Cmnd
+ * Scatterlist case:
+ * We set up the iscsi_chunk to point to the next
+ * scatterlist entry to copy to. As we go along,
+ * we move on to the next scatterlist entry and
+ * update the digest per-entry.
+ */
+ if (conn->datadgst_en)
+ rx_hash = &tcp_conn->rx_hash;
+
+ debug_tcp("iscsi_tcp_begin_data_in(%p, offset=%d, "
+ "datalen=%d)\n", tcp_conn,
+ tcp_ctask->data_offset,
+ tcp_conn->in.datalen);
+ return iscsi_chunk_seek_sg(&tcp_conn->in.chunk,
+ scsi_sglist(ctask->sc),
+ scsi_sg_count(ctask->sc),
+ tcp_ctask->data_offset,
+ tcp_conn->in.datalen,
+ iscsi_tcp_process_data_in,
+ rx_hash);
+ }
/* fall through */
case ISCSI_OP_SCSI_CMD_RSP:
- tcp_conn->in.ctask = session->cmds[itt];
- if (tcp_conn->in.datalen)
- goto copy_hdr;
-
- spin_lock(&session->lock);
- rc = __iscsi_complete_pdu(conn, hdr, NULL, 0);
- spin_unlock(&session->lock);
+ if (tcp_conn->in.datalen) {
+ iscsi_tcp_data_recv_prep(tcp_conn);
+ return 0;
+ }
+ rc = iscsi_complete_pdu(conn, hdr, NULL, 0);
break;
case ISCSI_OP_R2T:
- tcp_conn->in.ctask = session->cmds[itt];
+ ctask = session->cmds[itt];
if (ahslen)
rc = ISCSI_ERR_AHSLEN;
- else if (tcp_conn->in.ctask->sc->sc_data_direction ==
- DMA_TO_DEVICE)
- rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask);
+ else if (ctask->sc->sc_data_direction == DMA_TO_DEVICE)
+ rc = iscsi_r2t_rsp(conn, ctask);
else
rc = ISCSI_ERR_PROTO;
break;
* than 8K, but there are no targets that currently do this.
* For now we fail until we find a vendor that needs it
*/
- if (ISCSI_DEF_MAX_RECV_SEG_LEN <
- tcp_conn->in.datalen) {
+ if (ISCSI_DEF_MAX_RECV_SEG_LEN < tcp_conn->in.datalen) {
printk(KERN_ERR "iscsi_tcp: received buffer of len %u "
"but conn buffer is only %u (opcode %0x)\n",
tcp_conn->in.datalen,
break;
}
- if (tcp_conn->in.datalen)
- goto copy_hdr;
+ /* If there's data coming in with the response,
+ * receive it to the connection's buffer.
+ */
+ if (tcp_conn->in.datalen) {
+ iscsi_tcp_data_recv_prep(tcp_conn);
+ return 0;
+ }
/* fall through */
case ISCSI_OP_LOGOUT_RSP:
case ISCSI_OP_NOOP_IN:
break;
}
- return rc;
-
-copy_hdr:
- /*
- * if we did zero copy for the header but we will need multiple
- * skbs to complete the command then we have to copy the header
- * for later use
- */
- if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <=
- (tcp_conn->in.datalen + tcp_conn->in.padding +
- (conn->datadgst_en ? 4 : 0))) {
- debug_tcp("Copying header for later use. in.copy %d in.datalen"
- " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen);
- memcpy(&tcp_conn->hdr, tcp_conn->in.hdr,
- sizeof(struct iscsi_hdr));
- tcp_conn->in.hdr = &tcp_conn->hdr;
- tcp_conn->in.zero_copy_hdr = 0;
- }
- return 0;
-}
-
-/**
- * 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);
- unsigned 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 > scsi_bufflen(ctask->sc));
-
- 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;
+ if (rc == 0) {
+ /* Anything that comes with data should have
+ * been handled above. */
+ if (tcp_conn->in.datalen)
+ return ISCSI_ERR_PROTO;
+ iscsi_tcp_hdr_recv_prep(tcp_conn);
}
- /* done with this buffer or with both - PDU and buffer */
- tcp_conn->data_copied = 0;
- return 0;
-}
-
-/**
- * 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.
- **/
-static inline int
-iscsi_tcp_copy(struct iscsi_conn *conn, int buf_size)
-{
- struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
- 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*)conn->data + 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;
+ return rc;
}
static inline void
crypto_hash_update(desc, &temp, length);
}
-static void
-iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len)
-{
- struct scatterlist tmp;
-
- sg_init_one(&tmp, buf, len);
- crypto_hash_update(&tcp_conn->rx_hash, &tmp, len);
-}
-
-static int iscsi_scsi_data_in(struct iscsi_conn *conn)
+/**
+ * iscsi_tcp_hdr_recv_done - process PDU header
+ *
+ * This is the callback invoked when the PDU header has
+ * been received. If the header is followed by additional
+ * header segments, we go back for more data.
+ */
+static int
+iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn,
+ struct iscsi_chunk *chunk)
{
- struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
- struct iscsi_cmd_task *ctask = tcp_conn->in.ctask;
- struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
- struct scsi_cmnd *sc = ctask->sc;
- struct scatterlist *sg;
- int i, offset, rc = 0;
-
- BUG_ON((void*)ctask != sc->SCp.ptr);
-
- offset = tcp_ctask->data_offset;
- sg = scsi_sglist(sc);
-
- if (tcp_ctask->data_offset)
- for (i = 0; i < tcp_ctask->sg_count; i++)
- offset -= sg[i].length;
- /* we've passed through partial sg*/
- if (offset < 0)
- offset = 0;
-
- for (i = tcp_ctask->sg_count; i < scsi_sg_count(sc); i++) {
- char *dest;
-
- dest = kmap_atomic(sg_page(&sg[i]), KM_SOFTIRQ0);
- rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset,
- sg[i].length, offset);
- kunmap_atomic(dest, KM_SOFTIRQ0);
- if (rc == -EAGAIN)
- /* continue with the next SKB/PDU */
- return rc;
- if (!rc) {
- if (conn->datadgst_en) {
- if (!offset)
- crypto_hash_update(
- &tcp_conn->rx_hash,
- &sg[i], sg[i].length);
- else
- partial_sg_digest_update(
- &tcp_conn->rx_hash,
- &sg[i],
- sg[i].offset + offset,
- sg[i].length - offset);
- }
- offset = 0;
- tcp_ctask->sg_count++;
- }
-
- if (!ctask->data_count) {
- if (rc && conn->datadgst_en)
- /*
- * data-in is complete, but buffer not...
- */
- partial_sg_digest_update(&tcp_conn->rx_hash,
- &sg[i],
- sg[i].offset,
- sg[i].length-rc);
- rc = 0;
- break;
- }
-
- if (!tcp_conn->in.copy)
- return -EAGAIN;
- }
- BUG_ON(ctask->data_count);
+ struct iscsi_conn *conn = tcp_conn->iscsi_conn;
+ struct iscsi_hdr *hdr;
- /* check for non-exceptional status */
- if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
- debug_scsi("done [sc %lx res %d itt 0x%x flags 0x%x]\n",
- (long)sc, sc->result, ctask->itt,
- tcp_conn->in.hdr->flags);
- spin_lock(&conn->session->lock);
- __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0);
- spin_unlock(&conn->session->lock);
+ /* Check if there are additional header segments
+ * *prior* to computing the digest, because we
+ * may need to go back to the caller for more.
+ */
+ hdr = (struct iscsi_hdr *) tcp_conn->in.hdr_buf;
+ if (chunk->copied == sizeof(struct iscsi_hdr) && hdr->hlength) {
+ /* Bump the header length - the caller will
+ * just loop around and get the AHS for us, and
+ * call again. */
+ unsigned int ahslen = hdr->hlength << 2;
+
+ /* Make sure we don't overflow */
+ if (sizeof(*hdr) + ahslen > sizeof(tcp_conn->in.hdr_buf))
+ return ISCSI_ERR_AHSLEN;
+
+ chunk->total_size += ahslen;
+ chunk->size += ahslen;
+ return 0;
}
- return rc;
-}
-
-static int
-iscsi_data_recv(struct iscsi_conn *conn)
-{
- struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
- int rc = 0, opcode;
-
- opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK;
- switch (opcode) {
- case ISCSI_OP_SCSI_DATA_IN:
- rc = iscsi_scsi_data_in(conn);
- break;
- case ISCSI_OP_SCSI_CMD_RSP:
- case ISCSI_OP_TEXT_RSP:
- case ISCSI_OP_LOGIN_RSP:
- case ISCSI_OP_ASYNC_EVENT:
- case ISCSI_OP_REJECT:
- /*
- * Collect data segment to the connection's data
- * placeholder
- */
- if (iscsi_tcp_copy(conn, tcp_conn->in.datalen)) {
- rc = -EAGAIN;
- goto exit;
+ /* We're done processing the header. See if we're doing
+ * header digests; if so, set up the recv_digest buffer
+ * and go back for more. */
+ if (conn->hdrdgst_en) {
+ if (chunk->digest_len == 0) {
+ iscsi_tcp_chunk_splice_digest(chunk,
+ chunk->recv_digest);
+ return 0;
}
+ iscsi_tcp_dgst_header(&tcp_conn->rx_hash, hdr,
+ chunk->total_copied - ISCSI_DIGEST_SIZE,
+ chunk->digest);
- rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, conn->data,
- tcp_conn->in.datalen);
- if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP)
- iscsi_recv_digest_update(tcp_conn, conn->data,
- tcp_conn->in.datalen);
- break;
- default:
- BUG_ON(1);
+ if (!iscsi_tcp_dgst_verify(tcp_conn, chunk))
+ return ISCSI_ERR_HDR_DGST;
}
-exit:
- return rc;
+
+ tcp_conn->in.hdr = hdr;
+ return iscsi_tcp_hdr_dissect(conn, hdr);
}
/**
- * iscsi_tcp_data_recv - TCP receive in sendfile fashion
+ * iscsi_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_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
- unsigned int offset, size_t len)
+iscsi_tcp_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);
+ struct iscsi_chunk *chunk = &tcp_conn->in.chunk;
+ struct skb_seq_state seq;
+ unsigned int consumed = 0;
+ int rc = 0;
-more:
- tcp_conn->in.copied = 0;
- rc = 0;
+ debug_tcp("in %d bytes\n", skb->len - offset);
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 = iscsi_tcp_hdr_recv(conn);
- if (!rc && tcp_conn->in.datalen) {
- if (conn->datadgst_en)
- crypto_hash_init(&tcp_conn->rx_hash);
- tcp_conn->in_progress = IN_PROGRESS_DATA_RECV;
- } else if (rc) {
- iscsi_conn_failure(conn, rc);
- return 0;
- }
- }
-
- if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV &&
- tcp_conn->in.copy) {
- uint32_t recv_digest;
+ skb_prepare_seq_read(skb, offset, skb->len, &seq);
+ while (1) {
+ unsigned int avail;
+ const u8 *ptr;
- debug_tcp("extra data_recv offset %d copy %d\n",
- tcp_conn->in.offset, tcp_conn->in.copy);
-
- if (!tcp_conn->data_copied) {
- 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_hash_update(&tcp_conn->rx_hash,
- &sg, sg.length);
+ avail = skb_seq_read(consumed, &ptr, &seq);
+ if (avail == 0)
+ break;
+ BUG_ON(chunk->copied >= chunk->size);
+
+ debug_tcp("skb %p ptr=%p avail=%u\n", skb, ptr, avail);
+ rc = iscsi_tcp_chunk_recv(tcp_conn, chunk, ptr, avail);
+ BUG_ON(rc == 0);
+ consumed += rc;
+
+ if (chunk->total_copied >= chunk->total_size) {
+ rc = chunk->done(tcp_conn, chunk);
+ if (rc != 0) {
+ skb_abort_seq_read(&seq);
+ goto error;
}
- crypto_hash_final(&tcp_conn->rx_hash,
- (u8 *) &tcp_conn->in.datadgst);
- debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst);
- }
-
- rc = iscsi_tcp_copy(conn, sizeof(uint32_t));
- if (rc) {
- if (rc == -EAGAIN)
- goto again;
- iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
- return 0;
- }
-
- memcpy(&recv_digest, conn->data, sizeof(uint32_t));
- 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 (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 = iscsi_data_recv(conn);
- if (rc) {
- if (rc == -EAGAIN)
- goto again;
- iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
- return 0;
+ /* The done() functions sets up the
+ * next chunk. */
}
-
- if (tcp_conn->in.padding)
- tcp_conn->in_progress = IN_PROGRESS_PAD_RECV;
- else if (conn->datadgst_en)
- tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
- else
- tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
- tcp_conn->data_copied = 0;
- }
-
- if (tcp_conn->in_progress == IN_PROGRESS_PAD_RECV &&
- tcp_conn->in.copy) {
- int copylen = min(tcp_conn->in.padding - tcp_conn->data_copied,
- tcp_conn->in.copy);
-
- tcp_conn->in.copy -= copylen;
- tcp_conn->in.offset += copylen;
- tcp_conn->data_copied += copylen;
-
- if (tcp_conn->data_copied != tcp_conn->in.padding)
- tcp_conn->in_progress = IN_PROGRESS_PAD_RECV;
- else if (conn->datadgst_en)
- tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV;
- else
- tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
- tcp_conn->data_copied = 0;
}
- 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);
+ conn->rxdata_octets += consumed;
+ return consumed;
- 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;
+error:
+ debug_tcp("Error receiving PDU, errno=%d\n", rc);
+ iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+ return 0;
}
static void
iscsi_tcp_data_ready(struct sock *sk, int flag)
{
struct iscsi_conn *conn = sk->sk_user_data;
+ struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
read_descriptor_t rd_desc;
read_lock(&sk->sk_callback_lock);
/*
- * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv.
+ * 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_data_recv
+ * 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_tcp_data_recv);
+ tcp_read_sock(sk, &rd_desc, iscsi_tcp_recv);
read_unlock(&sk->sk_callback_lock);
+
+ /* If we had to (atomically) map a highmem page,
+ * unmap it now. */
+ iscsi_tcp_chunk_unmap(&tcp_conn->in.chunk);
}
static void
* slab case.
*/
if (buf->use_sendmsg)
- res = sock_no_sendpage(sk, sg_page(&buf->sg), offset, size, flags);
+ res = sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
else
- res = tcp_conn->sendpage(sk, sg_page(&buf->sg), offset, size, flags);
+ res = tcp_conn->sendpage(sk, buf->sg.page, offset, size, flags);
if (res >= 0) {
conn->txdata_octets += res;
conn->dd_data = tcp_conn;
tcp_conn->iscsi_conn = conn;
- tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
- /* initial operational parameters */
- tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
tcp_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0,
CRYPTO_ALG_ASYNC);
iscsi_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;
iscsi_conn_stop(cls_conn, flag);
iscsi_tcp_release_conn(conn);
- tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
}
static int iscsi_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock,
/*
* set receive state machine into initial state
*/
- tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER;
+ iscsi_tcp_hdr_recv_prep(tcp_conn);
return 0;
free_socket:
switch(param) {
case ISCSI_PARAM_HDRDGST_EN:
iscsi_set_param(cls_conn, param, buf, buflen);
- tcp_conn->hdr_size = sizeof(struct iscsi_hdr);
- if (conn->hdrdgst_en)
- tcp_conn->hdr_size += sizeof(__u32);
break;
case ISCSI_PARAM_DATADGST_EN:
iscsi_set_param(cls_conn, param, buf, buflen);
git://ftp.safe.ca / safe / jmp / linux-2.6 / commitdiff