| /* |
| * iSCSI over TCP/IP Data-Path lib |
| * |
| * 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 <linux/types.h> |
| #include <linux/list.h> |
| #include <linux/inet.h> |
| #include <linux/slab.h> |
| #include <linux/file.h> |
| #include <linux/blkdev.h> |
| #include <linux/crypto.h> |
| #include <linux/delay.h> |
| #include <linux/kfifo.h> |
| #include <linux/scatterlist.h> |
| #include <linux/module.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 int iscsi_dbg_libtcp; |
| module_param_named(debug_libiscsi_tcp, iscsi_dbg_libtcp, int, |
| S_IRUGO | S_IWUSR); |
| MODULE_PARM_DESC(debug_libiscsi_tcp, "Turn on debugging for libiscsi_tcp " |
| "module. Set to 1 to turn on, and zero to turn off. Default " |
| "is off."); |
| |
| #define ISCSI_DBG_TCP(_conn, dbg_fmt, arg...) \ |
| do { \ |
| if (iscsi_dbg_libtcp) \ |
| iscsi_conn_printk(KERN_INFO, _conn, \ |
| "%s " dbg_fmt, \ |
| __func__, ##arg); \ |
| } while (0); |
| |
| static int iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn, |
| struct iscsi_segment *segment); |
| |
| /* |
| * Scatterlist handling: inside the iscsi_segment, 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_segment_init_sg - init indicated scatterlist entry |
| * @segment: the buffer object |
| * @sg: scatterlist |
| * @offset: byte offset into that sg entry |
| * |
| * This function sets up the segment so that subsequent |
| * data is copied to the indicated sg entry, at the given |
| * offset. |
| */ |
| static inline void |
| iscsi_tcp_segment_init_sg(struct iscsi_segment *segment, |
| struct scatterlist *sg, unsigned int offset) |
| { |
| segment->sg = sg; |
| segment->sg_offset = offset; |
| segment->size = min(sg->length - offset, |
| segment->total_size - segment->total_copied); |
| segment->data = NULL; |
| } |
| |
| /** |
| * iscsi_tcp_segment_map - map the current S/G page |
| * @segment: iscsi_segment |
| * @recv: 1 if called from recv path |
| * |
| * 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 void iscsi_tcp_segment_map(struct iscsi_segment *segment, int recv) |
| { |
| struct scatterlist *sg; |
| |
| if (segment->data != NULL || !segment->sg) |
| return; |
| |
| sg = segment->sg; |
| BUG_ON(segment->sg_mapped); |
| BUG_ON(sg->length == 0); |
| |
| /* |
| * If the page count is greater than one it is ok to send |
| * to the network layer's zero copy send path. If not we |
| * have to go the slow sendmsg path. We always map for the |
| * recv path. |
| */ |
| if (page_count(sg_page(sg)) >= 1 && !recv) |
| return; |
| |
| if (recv) { |
| segment->atomic_mapped = true; |
| segment->sg_mapped = kmap_atomic(sg_page(sg), KM_SOFTIRQ0); |
| } else { |
| segment->atomic_mapped = false; |
| /* the xmit path can sleep with the page mapped so use kmap */ |
| segment->sg_mapped = kmap(sg_page(sg)); |
| } |
| |
| segment->data = segment->sg_mapped + sg->offset + segment->sg_offset; |
| } |
| |
| void iscsi_tcp_segment_unmap(struct iscsi_segment *segment) |
| { |
| if (segment->sg_mapped) { |
| if (segment->atomic_mapped) |
| kunmap_atomic(segment->sg_mapped, KM_SOFTIRQ0); |
| else |
| kunmap(sg_page(segment->sg)); |
| segment->sg_mapped = NULL; |
| segment->data = NULL; |
| } |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_segment_unmap); |
| |
| /* |
| * Splice the digest buffer into the buffer |
| */ |
| static inline void |
| iscsi_tcp_segment_splice_digest(struct iscsi_segment *segment, void *digest) |
| { |
| segment->data = digest; |
| segment->digest_len = ISCSI_DIGEST_SIZE; |
| segment->total_size += ISCSI_DIGEST_SIZE; |
| segment->size = ISCSI_DIGEST_SIZE; |
| segment->copied = 0; |
| segment->sg = NULL; |
| segment->hash = NULL; |
| } |
| |
| /** |
| * iscsi_tcp_segment_done - check whether the segment is complete |
| * @tcp_conn: iscsi tcp connection |
| * @segment: iscsi segment to check |
| * @recv: set to one of this is called from the recv path |
| * @copied: number of bytes copied |
| * |
| * Check if we're done receiving this segment. 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. |
| */ |
| int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn, |
| struct iscsi_segment *segment, int recv, |
| unsigned copied) |
| { |
| struct scatterlist sg; |
| unsigned int pad; |
| |
| ISCSI_DBG_TCP(tcp_conn->iscsi_conn, "copied %u %u size %u %s\n", |
| segment->copied, copied, segment->size, |
| recv ? "recv" : "xmit"); |
| if (segment->hash && copied) { |
| /* |
| * If a segment is kmapd we must unmap it before sending |
| * to the crypto layer since that will try to kmap it again. |
| */ |
| iscsi_tcp_segment_unmap(segment); |
| |
| if (!segment->data) { |
| sg_init_table(&sg, 1); |
| sg_set_page(&sg, sg_page(segment->sg), copied, |
| segment->copied + segment->sg_offset + |
| segment->sg->offset); |
| } else |
| sg_init_one(&sg, segment->data + segment->copied, |
| copied); |
| crypto_hash_update(segment->hash, &sg, copied); |
| } |
| |
| segment->copied += copied; |
| if (segment->copied < segment->size) { |
| iscsi_tcp_segment_map(segment, recv); |
| return 0; |
| } |
| |
| segment->total_copied += segment->copied; |
| segment->copied = 0; |
| segment->size = 0; |
| |
| /* Unmap the current scatterlist page, if there is one. */ |
| iscsi_tcp_segment_unmap(segment); |
| |
| /* Do we have more scatterlist entries? */ |
| ISCSI_DBG_TCP(tcp_conn->iscsi_conn, "total copied %u total size %u\n", |
| segment->total_copied, segment->total_size); |
| if (segment->total_copied < segment->total_size) { |
| /* Proceed to the next entry in the scatterlist. */ |
| iscsi_tcp_segment_init_sg(segment, sg_next(segment->sg), |
| 0); |
| iscsi_tcp_segment_map(segment, recv); |
| BUG_ON(segment->size == 0); |
| return 0; |
| } |
| |
| /* Do we need to handle padding? */ |
| if (!(tcp_conn->iscsi_conn->session->tt->caps & CAP_PADDING_OFFLOAD)) { |
| pad = iscsi_padding(segment->total_copied); |
| if (pad != 0) { |
| ISCSI_DBG_TCP(tcp_conn->iscsi_conn, |
| "consume %d pad bytes\n", pad); |
| segment->total_size += pad; |
| segment->size = pad; |
| segment->data = segment->padbuf; |
| return 0; |
| } |
| } |
| |
| /* |
| * Set us up for transferring the data digest. hdr digest |
| * is completely handled in hdr done function. |
| */ |
| if (segment->hash) { |
| crypto_hash_final(segment->hash, segment->digest); |
| iscsi_tcp_segment_splice_digest(segment, |
| recv ? segment->recv_digest : segment->digest); |
| return 0; |
| } |
| |
| return 1; |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_segment_done); |
| |
| /** |
| * iscsi_tcp_segment_recv - copy data to segment |
| * @tcp_conn: the iSCSI TCP connection |
| * @segment: 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_segment_recv(struct iscsi_tcp_conn *tcp_conn, |
| struct iscsi_segment *segment, const void *ptr, |
| unsigned int len) |
| { |
| unsigned int copy = 0, copied = 0; |
| |
| while (!iscsi_tcp_segment_done(tcp_conn, segment, 1, copy)) { |
| if (copied == len) { |
| ISCSI_DBG_TCP(tcp_conn->iscsi_conn, |
| "copied %d bytes\n", len); |
| break; |
| } |
| |
| copy = min(len - copied, segment->size - segment->copied); |
| ISCSI_DBG_TCP(tcp_conn->iscsi_conn, "copying %d\n", copy); |
| memcpy(segment->data + segment->copied, ptr + copied, copy); |
| copied += copy; |
| } |
| return copied; |
| } |
| |
| 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); |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_dgst_header); |
| |
| static inline int |
| iscsi_tcp_dgst_verify(struct iscsi_tcp_conn *tcp_conn, |
| struct iscsi_segment *segment) |
| { |
| if (!segment->digest_len) |
| return 1; |
| |
| if (memcmp(segment->recv_digest, segment->digest, |
| segment->digest_len)) { |
| ISCSI_DBG_TCP(tcp_conn->iscsi_conn, "digest mismatch\n"); |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| /* |
| * Helper function to set up segment buffer |
| */ |
| static inline void |
| __iscsi_segment_init(struct iscsi_segment *segment, size_t size, |
| iscsi_segment_done_fn_t *done, struct hash_desc *hash) |
| { |
| memset(segment, 0, sizeof(*segment)); |
| segment->total_size = size; |
| segment->done = done; |
| |
| if (hash) { |
| segment->hash = hash; |
| crypto_hash_init(hash); |
| } |
| } |
| |
| inline void |
| iscsi_segment_init_linear(struct iscsi_segment *segment, void *data, |
| size_t size, iscsi_segment_done_fn_t *done, |
| struct hash_desc *hash) |
| { |
| __iscsi_segment_init(segment, size, done, hash); |
| segment->data = data; |
| segment->size = size; |
| } |
| EXPORT_SYMBOL_GPL(iscsi_segment_init_linear); |
| |
| inline int |
| iscsi_segment_seek_sg(struct iscsi_segment *segment, |
| struct scatterlist *sg_list, unsigned int sg_count, |
| unsigned int offset, size_t size, |
| iscsi_segment_done_fn_t *done, struct hash_desc *hash) |
| { |
| struct scatterlist *sg; |
| unsigned int i; |
| |
| __iscsi_segment_init(segment, size, done, hash); |
| for_each_sg(sg_list, sg, sg_count, i) { |
| if (offset < sg->length) { |
| iscsi_tcp_segment_init_sg(segment, sg, offset); |
| return 0; |
| } |
| offset -= sg->length; |
| } |
| |
| return ISCSI_ERR_DATA_OFFSET; |
| } |
| EXPORT_SYMBOL_GPL(iscsi_segment_seek_sg); |
| |
| /** |
| * iscsi_tcp_hdr_recv_prep - prep segment 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. |
| */ |
| void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn) |
| { |
| ISCSI_DBG_TCP(tcp_conn->iscsi_conn, |
| "(%s)\n", tcp_conn->iscsi_conn->hdrdgst_en ? |
| "digest enabled" : "digest disabled"); |
| iscsi_segment_init_linear(&tcp_conn->in.segment, |
| tcp_conn->in.hdr_buf, sizeof(struct iscsi_hdr), |
| iscsi_tcp_hdr_recv_done, NULL); |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_hdr_recv_prep); |
| |
| /* |
| * Handle incoming reply to any other type of command |
| */ |
| static int |
| iscsi_tcp_data_recv_done(struct iscsi_tcp_conn *tcp_conn, |
| struct iscsi_segment *segment) |
| { |
| struct iscsi_conn *conn = tcp_conn->iscsi_conn; |
| int rc = 0; |
| |
| if (!iscsi_tcp_dgst_verify(tcp_conn, segment)) |
| 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 && |
| !(conn->session->tt->caps & CAP_DIGEST_OFFLOAD)) |
| rx_hash = tcp_conn->rx_hash; |
| |
| iscsi_segment_init_linear(&tcp_conn->in.segment, |
| conn->data, tcp_conn->in.datalen, |
| iscsi_tcp_data_recv_done, rx_hash); |
| } |
| |
| /** |
| * iscsi_tcp_cleanup_task - free tcp_task resources |
| * @task: iscsi task |
| * |
| * must be called with session lock |
| */ |
| void iscsi_tcp_cleanup_task(struct iscsi_task *task) |
| { |
| struct iscsi_tcp_task *tcp_task = task->dd_data; |
| struct iscsi_r2t_info *r2t; |
| |
| /* nothing to do for mgmt */ |
| if (!task->sc) |
| return; |
| |
| /* flush task's r2t queues */ |
| while (kfifo_out(&tcp_task->r2tqueue, (void*)&r2t, sizeof(void*))) { |
| kfifo_in(&tcp_task->r2tpool.queue, (void*)&r2t, |
| sizeof(void*)); |
| ISCSI_DBG_TCP(task->conn, "pending r2t dropped\n"); |
| } |
| |
| r2t = tcp_task->r2t; |
| if (r2t != NULL) { |
| kfifo_in(&tcp_task->r2tpool.queue, (void*)&r2t, |
| sizeof(void*)); |
| tcp_task->r2t = NULL; |
| } |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_cleanup_task); |
| |
| /** |
| * iscsi_tcp_data_in - SCSI Data-In Response processing |
| * @conn: iscsi connection |
| * @task: scsi command task |
| */ |
| static int iscsi_tcp_data_in(struct iscsi_conn *conn, struct iscsi_task *task) |
| { |
| struct iscsi_tcp_conn *tcp_conn = conn->dd_data; |
| struct iscsi_tcp_task *tcp_task = task->dd_data; |
| struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr; |
| int datasn = be32_to_cpu(rhdr->datasn); |
| unsigned total_in_length = scsi_in(task->sc)->length; |
| |
| /* |
| * lib iscsi will update this in the completion handling if there |
| * is status. |
| */ |
| if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS)) |
| iscsi_update_cmdsn(conn->session, (struct iscsi_nopin*)rhdr); |
| |
| if (tcp_conn->in.datalen == 0) |
| return 0; |
| |
| if (tcp_task->exp_datasn != datasn) { |
| ISCSI_DBG_TCP(conn, "task->exp_datasn(%d) != rhdr->datasn(%d)" |
| "\n", tcp_task->exp_datasn, datasn); |
| return ISCSI_ERR_DATASN; |
| } |
| |
| tcp_task->exp_datasn++; |
| |
| tcp_task->data_offset = be32_to_cpu(rhdr->offset); |
| if (tcp_task->data_offset + tcp_conn->in.datalen > total_in_length) { |
| ISCSI_DBG_TCP(conn, "data_offset(%d) + data_len(%d) > " |
| "total_length_in(%d)\n", tcp_task->data_offset, |
| tcp_conn->in.datalen, total_in_length); |
| return ISCSI_ERR_DATA_OFFSET; |
| } |
| |
| conn->datain_pdus_cnt++; |
| return 0; |
| } |
| |
| /** |
| * iscsi_tcp_r2t_rsp - iSCSI R2T Response processing |
| * @conn: iscsi connection |
| * @task: scsi command task |
| */ |
| static int iscsi_tcp_r2t_rsp(struct iscsi_conn *conn, struct iscsi_task *task) |
| { |
| struct iscsi_session *session = conn->session; |
| struct iscsi_tcp_task *tcp_task = task->dd_data; |
| struct iscsi_tcp_conn *tcp_conn = conn->dd_data; |
| struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr; |
| struct iscsi_r2t_info *r2t; |
| int r2tsn = be32_to_cpu(rhdr->r2tsn); |
| int rc; |
| |
| if (tcp_conn->in.datalen) { |
| iscsi_conn_printk(KERN_ERR, conn, |
| "invalid R2t with datalen %d\n", |
| tcp_conn->in.datalen); |
| return ISCSI_ERR_DATALEN; |
| } |
| |
| if (tcp_task->exp_datasn != r2tsn){ |
| ISCSI_DBG_TCP(conn, "task->exp_datasn(%d) != rhdr->r2tsn(%d)\n", |
| tcp_task->exp_datasn, r2tsn); |
| return ISCSI_ERR_R2TSN; |
| } |
| |
| /* fill-in new R2T associated with the task */ |
| iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr); |
| |
| if (!task->sc || session->state != ISCSI_STATE_LOGGED_IN) { |
| iscsi_conn_printk(KERN_INFO, conn, |
| "dropping R2T itt %d in recovery.\n", |
| task->itt); |
| return 0; |
| } |
| |
| rc = kfifo_out(&tcp_task->r2tpool.queue, (void*)&r2t, sizeof(void*)); |
| if (!rc) { |
| iscsi_conn_printk(KERN_ERR, conn, "Could not allocate R2T. " |
| "Target has sent more R2Ts than it " |
| "negotiated for or driver has has leaked.\n"); |
| return ISCSI_ERR_PROTO; |
| } |
| |
| r2t->exp_statsn = rhdr->statsn; |
| r2t->data_length = be32_to_cpu(rhdr->data_length); |
| if (r2t->data_length == 0) { |
| iscsi_conn_printk(KERN_ERR, conn, |
| "invalid R2T with zero data len\n"); |
| kfifo_in(&tcp_task->r2tpool.queue, (void*)&r2t, |
| sizeof(void*)); |
| return ISCSI_ERR_DATALEN; |
| } |
| |
| if (r2t->data_length > session->max_burst) |
| ISCSI_DBG_TCP(conn, "invalid R2T with data len %u and max " |
| "burst %u. Attempting to execute request.\n", |
| r2t->data_length, session->max_burst); |
| |
| r2t->data_offset = be32_to_cpu(rhdr->data_offset); |
| if (r2t->data_offset + r2t->data_length > scsi_out(task->sc)->length) { |
| iscsi_conn_printk(KERN_ERR, conn, |
| "invalid R2T with data len %u at offset %u " |
| "and total length %d\n", r2t->data_length, |
| r2t->data_offset, scsi_out(task->sc)->length); |
| kfifo_in(&tcp_task->r2tpool.queue, (void*)&r2t, |
| sizeof(void*)); |
| return ISCSI_ERR_DATALEN; |
| } |
| |
| r2t->ttt = rhdr->ttt; /* no flip */ |
| r2t->datasn = 0; |
| r2t->sent = 0; |
| |
| tcp_task->exp_datasn = r2tsn + 1; |
| kfifo_in(&tcp_task->r2tqueue, (void*)&r2t, sizeof(void*)); |
| conn->r2t_pdus_cnt++; |
| |
| iscsi_requeue_task(task); |
| return 0; |
| } |
| |
| /* |
| * Handle incoming reply to DataIn command |
| */ |
| static int |
| iscsi_tcp_process_data_in(struct iscsi_tcp_conn *tcp_conn, |
| struct iscsi_segment *segment) |
| { |
| 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, segment)) |
| 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_tcp_conn *tcp_conn = conn->dd_data; |
| struct iscsi_task *task; |
| |
| /* verify PDU length */ |
| tcp_conn->in.datalen = ntoh24(hdr->dlength); |
| if (tcp_conn->in.datalen > conn->max_recv_dlength) { |
| iscsi_conn_printk(KERN_ERR, conn, |
| "iscsi_tcp: datalen %d > %d\n", |
| tcp_conn->in.datalen, conn->max_recv_dlength); |
| return ISCSI_ERR_DATALEN; |
| } |
| |
| /* Additional header segments. So far, we don't |
| * process additional headers. |
| */ |
| ahslen = hdr->hlength << 2; |
| |
| opcode = hdr->opcode & ISCSI_OPCODE_MASK; |
| /* verify itt (itt encoding: age+cid+itt) */ |
| rc = iscsi_verify_itt(conn, hdr->itt); |
| if (rc) |
| return rc; |
| |
| ISCSI_DBG_TCP(conn, "opcode 0x%x ahslen %d datalen %d\n", |
| opcode, ahslen, tcp_conn->in.datalen); |
| |
| switch(opcode) { |
| case ISCSI_OP_SCSI_DATA_IN: |
| spin_lock(&conn->session->lock); |
| task = iscsi_itt_to_ctask(conn, hdr->itt); |
| if (!task) |
| rc = ISCSI_ERR_BAD_ITT; |
| else |
| rc = iscsi_tcp_data_in(conn, task); |
| if (rc) { |
| spin_unlock(&conn->session->lock); |
| break; |
| } |
| |
| if (tcp_conn->in.datalen) { |
| struct iscsi_tcp_task *tcp_task = task->dd_data; |
| struct hash_desc *rx_hash = NULL; |
| struct scsi_data_buffer *sdb = scsi_in(task->sc); |
| |
| /* |
| * Setup copy of Data-In into the Scsi_Cmnd |
| * Scatterlist case: |
| * We set up the iscsi_segment 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 && |
| !(conn->session->tt->caps & CAP_DIGEST_OFFLOAD)) |
| rx_hash = tcp_conn->rx_hash; |
| |
| ISCSI_DBG_TCP(conn, "iscsi_tcp_begin_data_in( " |
| "offset=%d, datalen=%d)\n", |
| tcp_task->data_offset, |
| tcp_conn->in.datalen); |
| task->last_xfer = jiffies; |
| rc = iscsi_segment_seek_sg(&tcp_conn->in.segment, |
| sdb->table.sgl, |
| sdb->table.nents, |
| tcp_task->data_offset, |
| tcp_conn->in.datalen, |
| iscsi_tcp_process_data_in, |
| rx_hash); |
| spin_unlock(&conn->session->lock); |
| return rc; |
| } |
| rc = __iscsi_complete_pdu(conn, hdr, NULL, 0); |
| spin_unlock(&conn->session->lock); |
| break; |
| case ISCSI_OP_SCSI_CMD_RSP: |
| 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: |
| spin_lock(&conn->session->lock); |
| task = iscsi_itt_to_ctask(conn, hdr->itt); |
| if (!task) |
| rc = ISCSI_ERR_BAD_ITT; |
| else if (ahslen) |
| rc = ISCSI_ERR_AHSLEN; |
| else if (task->sc->sc_data_direction == DMA_TO_DEVICE) { |
| task->last_xfer = jiffies; |
| rc = iscsi_tcp_r2t_rsp(conn, task); |
| } else |
| rc = ISCSI_ERR_PROTO; |
| spin_unlock(&conn->session->lock); |
| break; |
| case ISCSI_OP_LOGIN_RSP: |
| case ISCSI_OP_TEXT_RSP: |
| case ISCSI_OP_REJECT: |
| case ISCSI_OP_ASYNC_EVENT: |
| /* |
| * It is possible that we could get a PDU with a buffer larger |
| * 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) { |
| iscsi_conn_printk(KERN_ERR, conn, |
| "iscsi_tcp: received buffer of " |
| "len %u but conn buffer is only %u " |
| "(opcode %0x)\n", |
| tcp_conn->in.datalen, |
| ISCSI_DEF_MAX_RECV_SEG_LEN, opcode); |
| rc = ISCSI_ERR_PROTO; |
| break; |
| } |
| |
| /* 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: |
| case ISCSI_OP_SCSI_TMFUNC_RSP: |
| rc = iscsi_complete_pdu(conn, hdr, NULL, 0); |
| break; |
| default: |
| rc = ISCSI_ERR_BAD_OPCODE; |
| break; |
| } |
| |
| 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); |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * 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_segment *segment) |
| { |
| struct iscsi_conn *conn = tcp_conn->iscsi_conn; |
| struct iscsi_hdr *hdr; |
| |
| /* 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 (segment->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; |
| |
| segment->total_size += ahslen; |
| segment->size += ahslen; |
| return 0; |
| } |
| |
| /* 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 && |
| !(conn->session->tt->caps & CAP_DIGEST_OFFLOAD)) { |
| if (segment->digest_len == 0) { |
| /* |
| * Even if we offload the digest processing we |
| * splice it in so we can increment the skb/segment |
| * counters in preparation for the data segment. |
| */ |
| iscsi_tcp_segment_splice_digest(segment, |
| segment->recv_digest); |
| return 0; |
| } |
| |
| iscsi_tcp_dgst_header(tcp_conn->rx_hash, hdr, |
| segment->total_copied - ISCSI_DIGEST_SIZE, |
| segment->digest); |
| |
| if (!iscsi_tcp_dgst_verify(tcp_conn, segment)) |
| return ISCSI_ERR_HDR_DGST; |
| } |
| |
| tcp_conn->in.hdr = hdr; |
| return iscsi_tcp_hdr_dissect(conn, hdr); |
| } |
| |
| /** |
| * iscsi_tcp_recv_segment_is_hdr - tests if we are reading in a header |
| * @tcp_conn: iscsi tcp conn |
| * |
| * returns non zero if we are currently processing or setup to process |
| * a header. |
| */ |
| inline int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn) |
| { |
| return tcp_conn->in.segment.done == iscsi_tcp_hdr_recv_done; |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_recv_segment_is_hdr); |
| |
| /** |
| * iscsi_tcp_recv_skb - Process skb |
| * @conn: iscsi connection |
| * @skb: network buffer with header and/or data segment |
| * @offset: offset in skb |
| * @offload: bool indicating if transfer was offloaded |
| * |
| * Will return status of transfer in status. And will return |
| * number of bytes copied. |
| */ |
| int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb, |
| unsigned int offset, bool offloaded, int *status) |
| { |
| struct iscsi_tcp_conn *tcp_conn = conn->dd_data; |
| struct iscsi_segment *segment = &tcp_conn->in.segment; |
| struct skb_seq_state seq; |
| unsigned int consumed = 0; |
| int rc = 0; |
| |
| ISCSI_DBG_TCP(conn, "in %d bytes\n", skb->len - offset); |
| /* |
| * Update for each skb instead of pdu, because over slow networks a |
| * data_in's data could take a while to read in. We also want to |
| * account for r2ts. |
| */ |
| conn->last_recv = jiffies; |
| |
| if (unlikely(conn->suspend_rx)) { |
| ISCSI_DBG_TCP(conn, "Rx suspended!\n"); |
| *status = ISCSI_TCP_SUSPENDED; |
| return 0; |
| } |
| |
| if (offloaded) { |
| segment->total_copied = segment->total_size; |
| goto segment_done; |
| } |
| |
| skb_prepare_seq_read(skb, offset, skb->len, &seq); |
| while (1) { |
| unsigned int avail; |
| const u8 *ptr; |
| |
| avail = skb_seq_read(consumed, &ptr, &seq); |
| if (avail == 0) { |
| ISCSI_DBG_TCP(conn, "no more data avail. Consumed %d\n", |
| consumed); |
| *status = ISCSI_TCP_SKB_DONE; |
| skb_abort_seq_read(&seq); |
| goto skb_done; |
| } |
| BUG_ON(segment->copied >= segment->size); |
| |
| ISCSI_DBG_TCP(conn, "skb %p ptr=%p avail=%u\n", skb, ptr, |
| avail); |
| rc = iscsi_tcp_segment_recv(tcp_conn, segment, ptr, avail); |
| BUG_ON(rc == 0); |
| consumed += rc; |
| |
| if (segment->total_copied >= segment->total_size) { |
| skb_abort_seq_read(&seq); |
| goto segment_done; |
| } |
| } |
| |
| segment_done: |
| *status = ISCSI_TCP_SEGMENT_DONE; |
| ISCSI_DBG_TCP(conn, "segment done\n"); |
| rc = segment->done(tcp_conn, segment); |
| if (rc != 0) { |
| *status = ISCSI_TCP_CONN_ERR; |
| ISCSI_DBG_TCP(conn, "Error receiving PDU, errno=%d\n", rc); |
| iscsi_conn_failure(conn, rc); |
| return 0; |
| } |
| /* The done() functions sets up the next segment. */ |
| |
| skb_done: |
| conn->rxdata_octets += consumed; |
| return consumed; |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_recv_skb); |
| |
| /** |
| * iscsi_tcp_task_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands |
| * @conn: iscsi connection |
| * @task: scsi command task |
| * @sc: scsi command |
| */ |
| int iscsi_tcp_task_init(struct iscsi_task *task) |
| { |
| struct iscsi_tcp_task *tcp_task = task->dd_data; |
| struct iscsi_conn *conn = task->conn; |
| struct scsi_cmnd *sc = task->sc; |
| int err; |
| |
| if (!sc) { |
| /* |
| * mgmt tasks do not have a scatterlist since they come |
| * in from the iscsi interface. |
| */ |
| ISCSI_DBG_TCP(conn, "mtask deq [itt 0x%x]\n", task->itt); |
| |
| return conn->session->tt->init_pdu(task, 0, task->data_count); |
| } |
| |
| BUG_ON(kfifo_len(&tcp_task->r2tqueue)); |
| tcp_task->exp_datasn = 0; |
| |
| /* Prepare PDU, optionally w/ immediate data */ |
| ISCSI_DBG_TCP(conn, "task deq [itt 0x%x imm %d unsol %d]\n", |
| task->itt, task->imm_count, task->unsol_r2t.data_length); |
| |
| err = conn->session->tt->init_pdu(task, 0, task->imm_count); |
| if (err) |
| return err; |
| task->imm_count = 0; |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_task_init); |
| |
| static struct iscsi_r2t_info *iscsi_tcp_get_curr_r2t(struct iscsi_task *task) |
| { |
| struct iscsi_session *session = task->conn->session; |
| struct iscsi_tcp_task *tcp_task = task->dd_data; |
| struct iscsi_r2t_info *r2t = NULL; |
| |
| if (iscsi_task_has_unsol_data(task)) |
| r2t = &task->unsol_r2t; |
| else { |
| spin_lock_bh(&session->lock); |
| if (tcp_task->r2t) { |
| r2t = tcp_task->r2t; |
| /* Continue with this R2T? */ |
| if (r2t->data_length <= r2t->sent) { |
| ISCSI_DBG_TCP(task->conn, |
| " done with r2t %p\n", r2t); |
| kfifo_in(&tcp_task->r2tpool.queue, |
| (void *)&tcp_task->r2t, |
| sizeof(void *)); |
| tcp_task->r2t = r2t = NULL; |
| } |
| } |
| |
| if (r2t == NULL) { |
| if (kfifo_out(&tcp_task->r2tqueue, |
| (void *)&tcp_task->r2t, sizeof(void *)) != |
| sizeof(void *)) |
| r2t = NULL; |
| else |
| r2t = tcp_task->r2t; |
| } |
| spin_unlock_bh(&session->lock); |
| } |
| |
| return r2t; |
| } |
| |
| /** |
| * iscsi_tcp_task_xmit - xmit normal PDU task |
| * @task: iscsi command task |
| * |
| * We're expected to return 0 when everything was transmitted successfully, |
| * -EAGAIN if there's still data in the queue, or != 0 for any other kind |
| * of error. |
| */ |
| int iscsi_tcp_task_xmit(struct iscsi_task *task) |
| { |
| struct iscsi_conn *conn = task->conn; |
| struct iscsi_session *session = conn->session; |
| struct iscsi_r2t_info *r2t; |
| int rc = 0; |
| |
| flush: |
| /* Flush any pending data first. */ |
| rc = session->tt->xmit_pdu(task); |
| if (rc < 0) |
| return rc; |
| |
| /* mgmt command */ |
| if (!task->sc) { |
| if (task->hdr->itt == RESERVED_ITT) |
| iscsi_put_task(task); |
| return 0; |
| } |
| |
| /* Are we done already? */ |
| if (task->sc->sc_data_direction != DMA_TO_DEVICE) |
| return 0; |
| |
| r2t = iscsi_tcp_get_curr_r2t(task); |
| if (r2t == NULL) { |
| /* Waiting for more R2Ts to arrive. */ |
| ISCSI_DBG_TCP(conn, "no R2Ts yet\n"); |
| return 0; |
| } |
| |
| rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_DATA_OUT); |
| if (rc) |
| return rc; |
| iscsi_prep_data_out_pdu(task, r2t, (struct iscsi_data *) task->hdr); |
| |
| ISCSI_DBG_TCP(conn, "sol dout %p [dsn %d itt 0x%x doff %d dlen %d]\n", |
| r2t, r2t->datasn - 1, task->hdr->itt, |
| r2t->data_offset + r2t->sent, r2t->data_count); |
| |
| rc = conn->session->tt->init_pdu(task, r2t->data_offset + r2t->sent, |
| r2t->data_count); |
| if (rc) { |
| iscsi_conn_failure(conn, ISCSI_ERR_XMIT_FAILED); |
| return rc; |
| } |
| |
| r2t->sent += r2t->data_count; |
| goto flush; |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_task_xmit); |
| |
| struct iscsi_cls_conn * |
| iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size, |
| uint32_t conn_idx) |
| |
| { |
| struct iscsi_conn *conn; |
| struct iscsi_cls_conn *cls_conn; |
| struct iscsi_tcp_conn *tcp_conn; |
| |
| cls_conn = iscsi_conn_setup(cls_session, |
| sizeof(*tcp_conn) + dd_data_size, conn_idx); |
| if (!cls_conn) |
| return NULL; |
| conn = cls_conn->dd_data; |
| /* |
| * due to strange issues with iser these are not set |
| * in iscsi_conn_setup |
| */ |
| conn->max_recv_dlength = ISCSI_DEF_MAX_RECV_SEG_LEN; |
| |
| tcp_conn = conn->dd_data; |
| tcp_conn->iscsi_conn = conn; |
| tcp_conn->dd_data = conn->dd_data + sizeof(*tcp_conn); |
| return cls_conn; |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_conn_setup); |
| |
| void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn) |
| { |
| iscsi_conn_teardown(cls_conn); |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_conn_teardown); |
| |
| int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session) |
| { |
| int i; |
| int cmd_i; |
| |
| /* |
| * initialize per-task: R2T pool and xmit queue |
| */ |
| for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) { |
| struct iscsi_task *task = session->cmds[cmd_i]; |
| struct iscsi_tcp_task *tcp_task = task->dd_data; |
| |
| /* |
| * pre-allocated x2 as much r2ts to handle race when |
| * target acks DataOut faster than we data_xmit() queues |
| * could replenish r2tqueue. |
| */ |
| |
| /* R2T pool */ |
| if (iscsi_pool_init(&tcp_task->r2tpool, |
| session->max_r2t * 2, NULL, |
| sizeof(struct iscsi_r2t_info))) { |
| goto r2t_alloc_fail; |
| } |
| |
| /* R2T xmit queue */ |
| if (kfifo_alloc(&tcp_task->r2tqueue, |
| session->max_r2t * 4 * sizeof(void*), GFP_KERNEL)) { |
| iscsi_pool_free(&tcp_task->r2tpool); |
| goto r2t_alloc_fail; |
| } |
| } |
| |
| return 0; |
| |
| r2t_alloc_fail: |
| for (i = 0; i < cmd_i; i++) { |
| struct iscsi_task *task = session->cmds[i]; |
| struct iscsi_tcp_task *tcp_task = task->dd_data; |
| |
| kfifo_free(&tcp_task->r2tqueue); |
| iscsi_pool_free(&tcp_task->r2tpool); |
| } |
| return -ENOMEM; |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_r2tpool_alloc); |
| |
| void iscsi_tcp_r2tpool_free(struct iscsi_session *session) |
| { |
| int i; |
| |
| for (i = 0; i < session->cmds_max; i++) { |
| struct iscsi_task *task = session->cmds[i]; |
| struct iscsi_tcp_task *tcp_task = task->dd_data; |
| |
| kfifo_free(&tcp_task->r2tqueue); |
| iscsi_pool_free(&tcp_task->r2tpool); |
| } |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_r2tpool_free); |
| |
| int iscsi_tcp_set_max_r2t(struct iscsi_conn *conn, char *buf) |
| { |
| struct iscsi_session *session = conn->session; |
| unsigned short r2ts = 0; |
| |
| sscanf(buf, "%hu", &r2ts); |
| if (session->max_r2t == r2ts) |
| return 0; |
| |
| if (!r2ts || !is_power_of_2(r2ts)) |
| return -EINVAL; |
| |
| session->max_r2t = r2ts; |
| iscsi_tcp_r2tpool_free(session); |
| return iscsi_tcp_r2tpool_alloc(session); |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_set_max_r2t); |
| |
| void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn, |
| struct iscsi_stats *stats) |
| { |
| struct iscsi_conn *conn = cls_conn->dd_data; |
| |
| stats->txdata_octets = conn->txdata_octets; |
| stats->rxdata_octets = conn->rxdata_octets; |
| stats->scsicmd_pdus = conn->scsicmd_pdus_cnt; |
| stats->dataout_pdus = conn->dataout_pdus_cnt; |
| stats->scsirsp_pdus = conn->scsirsp_pdus_cnt; |
| stats->datain_pdus = conn->datain_pdus_cnt; |
| stats->r2t_pdus = conn->r2t_pdus_cnt; |
| stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt; |
| stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt; |
| } |
| EXPORT_SYMBOL_GPL(iscsi_tcp_conn_get_stats); |