/* * 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/file.h> #include <linux/blkdev.h> #include <linux/crypto.h> #include <linux/delay.h> #include <linux/kfifo.h> #include <linux/scatterlist.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; segment->sg_mapped = kmap_atomic(sg_page(sg), KM_SOFTIRQ0); segment->data = segment->sg_mapped + sg->offset + segment->sg_offset; } void iscsi_tcp_segment_unmap(struct iscsi_segment *segment) { if (segment->sg_mapped) { kunmap_atomic(segment->sg_mapped, KM_SOFTIRQ0); 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), 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 = kzalloc(dd_data_size, GFP_KERNEL); if (!tcp_conn->dd_data) { iscsi_conn_teardown(cls_conn); return NULL; } return cls_conn; } EXPORT_SYMBOL_GPL(iscsi_tcp_conn_setup); void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn) { struct iscsi_conn *conn = cls_conn->dd_data; struct iscsi_tcp_conn *tcp_conn = conn->dd_data; kfree(tcp_conn->dd_data); 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); 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);