/* * iSCSI Initiator over TCP/IP Data-Path * * Copyright (C) 2004 Dmitry Yusupov * Copyright (C) 2004 Alex Aizman * Copyright (C) 2005 - 2006 Mike Christie * Copyright (C) 2006 Red Hat, Inc. All rights reserved. * maintained by open-iscsi@googlegroups.com * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published * by the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * See the file COPYING included with this distribution for more details. * * Credits: * Christoph Hellwig * FUJITA Tomonori * Arne Redlich * Zhenyu Wang */ #include <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("Dmitry Yusupov <dmitry_yus@yahoo.com>, " "Alex Aizman <itn780@yahoo.com>"); MODULE_DESCRIPTION("iSCSI/TCP data-path"); MODULE_LICENSE("GPL"); #undef DEBUG_TCP #define DEBUG_ASSERT #ifdef DEBUG_TCP #define debug_tcp(fmt...) printk(KERN_INFO "tcp: " fmt) #else #define debug_tcp(fmt...) #endif #ifndef DEBUG_ASSERT #ifdef BUG_ON #undef BUG_ON #endif #define BUG_ON(expr) #endif 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_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 inline 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; debug_tcp("iscsi_tcp_segment_map %s %p\n", recv ? "recv" : "xmit", segment); segment->sg_mapped = kmap_atomic(sg_page(sg), KM_SOFTIRQ0); segment->data = segment->sg_mapped + sg->offset + segment->sg_offset; } static inline void iscsi_tcp_segment_unmap(struct iscsi_segment *segment) { debug_tcp("iscsi_tcp_segment_unmap %p\n", segment); if (segment->sg_mapped) { debug_tcp("iscsi_tcp_segment_unmap valid\n"); kunmap_atomic(segment->sg_mapped, KM_SOFTIRQ0); segment->sg_mapped = NULL; segment->data = NULL; } } /* * 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 * @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. */ static inline int iscsi_tcp_segment_done(struct iscsi_segment *segment, int recv, unsigned copied) { static unsigned char padbuf[ISCSI_PAD_LEN]; struct scatterlist sg; unsigned int pad; debug_tcp("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? */ debug_tcp("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? */ pad = iscsi_padding(segment->total_copied); if (pad != 0) { debug_tcp("consume %d pad bytes\n", pad); segment->total_size += pad; segment->size = pad; segment->data = 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; } /** * iscsi_tcp_xmit_segment - transmit segment * @tcp_conn: the iSCSI TCP connection * @segment: the buffer to transmnit * * This function transmits as much of the buffer as * the network layer will accept, and returns the number of * bytes transmitted. * * If CRC hashing is enabled, the function will compute the * hash as it goes. When the entire segment has been transmitted, * it will retrieve the hash value and send it as well. */ static int iscsi_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn, struct iscsi_segment *segment) { struct socket *sk = tcp_conn->sock; unsigned int copied = 0; int r = 0; while (!iscsi_tcp_segment_done(segment, 0, r)) { struct scatterlist *sg; unsigned int offset, copy; int flags = 0; r = 0; offset = segment->copied; copy = segment->size - offset; if (segment->total_copied + segment->size < segment->total_size) flags |= MSG_MORE; /* Use sendpage if we can; else fall back to sendmsg */ if (!segment->data) { sg = segment->sg; offset += segment->sg_offset + sg->offset; r = tcp_conn->sendpage(sk, sg_page(sg), offset, copy, flags); } else { struct msghdr msg = { .msg_flags = flags }; struct kvec iov = { .iov_base = segment->data + offset, .iov_len = copy }; r = kernel_sendmsg(sk, &msg, &iov, 1, copy); } if (r < 0) { iscsi_tcp_segment_unmap(segment); if (copied || r == -EAGAIN) break; return r; } copied += r; } return copied; } /** * iscsi_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(segment, 1, copy)) { if (copied == len) { debug_tcp("iscsi_tcp_segment_recv copied %d bytes\n", len); break; } copy = min(len - copied, segment->size - segment->copied); debug_tcp("iscsi_tcp_segment_recv copying %d\n", copy); memcpy(segment->data + segment->copied, ptr + copied, copy); copied += copy; } return copied; } 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_segment *segment) { if (!segment->digest_len) return 1; if (memcmp(segment->recv_digest, segment->digest, segment->digest_len)) { debug_scsi("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); } } static 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; } static 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; debug_scsi("iscsi_segment_seek_sg offset %u size %llu\n", offset, size); __iscsi_segment_init(segment, size, done, hash); for_each_sg(sg_list, sg, sg_count, i) { debug_scsi("sg %d, len %u offset %u\n", i, sg->length, sg->offset); if (offset < sg->length) { iscsi_tcp_segment_init_sg(segment, sg, offset); return 0; } offset -= sg->length; } return ISCSI_ERR_DATA_OFFSET; } /** * 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. */ 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_segment_init_linear(&tcp_conn->in.segment, 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_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) 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); } /* * must be called with session lock */ static void iscsi_tcp_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) { struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data; struct iscsi_r2t_info *r2t; /* flush ctask's r2t queues */ while (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*))) { __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*)); debug_scsi("iscsi_tcp_cleanup_ctask pending r2t dropped\n"); } r2t = tcp_ctask->r2t; if (r2t != NULL) { __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*)); tcp_ctask->r2t = NULL; } } /** * iscsi_data_rsp - SCSI Data-In Response processing * @conn: iscsi connection * @ctask: scsi command task **/ static int iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) { struct iscsi_tcp_conn *tcp_conn = conn->dd_data; struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data; struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr; struct iscsi_session *session = conn->session; struct scsi_cmnd *sc = ctask->sc; int datasn = be32_to_cpu(rhdr->datasn); unsigned total_in_length = scsi_in(sc)->length; iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr); if (tcp_conn->in.datalen == 0) return 0; if (tcp_ctask->exp_datasn != datasn) { debug_tcp("%s: ctask->exp_datasn(%d) != rhdr->datasn(%d)\n", __FUNCTION__, tcp_ctask->exp_datasn, datasn); return ISCSI_ERR_DATASN; } tcp_ctask->exp_datasn++; tcp_ctask->data_offset = be32_to_cpu(rhdr->offset); if (tcp_ctask->data_offset + tcp_conn->in.datalen > total_in_length) { debug_tcp("%s: data_offset(%d) + data_len(%d) > total_length_in(%d)\n", __FUNCTION__, tcp_ctask->data_offset, tcp_conn->in.datalen, total_in_length); return ISCSI_ERR_DATA_OFFSET; } if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) { sc->result = (DID_OK << 16) | rhdr->cmd_status; conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1; if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW | ISCSI_FLAG_DATA_OVERFLOW)) { int res_count = be32_to_cpu(rhdr->residual_count); if (res_count > 0 && (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW || res_count <= total_in_length)) scsi_in(sc)->resid = res_count; else sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status; } } conn->datain_pdus_cnt++; return 0; } /** * iscsi_solicit_data_init - initialize first Data-Out * @conn: iscsi connection * @ctask: scsi command task * @r2t: R2T info * * Notes: * Initialize first Data-Out within this R2T sequence and finds * proper data_offset within this SCSI command. * * This function is called with connection lock taken. **/ static void iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask, struct iscsi_r2t_info *r2t) { struct iscsi_data *hdr; hdr = &r2t->dtask.hdr; memset(hdr, 0, sizeof(struct iscsi_data)); hdr->ttt = r2t->ttt; hdr->datasn = cpu_to_be32(r2t->solicit_datasn); r2t->solicit_datasn++; hdr->opcode = ISCSI_OP_SCSI_DATA_OUT; memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun)); hdr->itt = ctask->hdr->itt; hdr->exp_statsn = r2t->exp_statsn; hdr->offset = cpu_to_be32(r2t->data_offset); if (r2t->data_length > conn->max_xmit_dlength) { hton24(hdr->dlength, conn->max_xmit_dlength); r2t->data_count = conn->max_xmit_dlength; hdr->flags = 0; } else { hton24(hdr->dlength, r2t->data_length); r2t->data_count = r2t->data_length; hdr->flags = ISCSI_FLAG_CMD_FINAL; } conn->dataout_pdus_cnt++; r2t->sent = 0; } /** * iscsi_r2t_rsp - iSCSI R2T Response processing * @conn: iscsi connection * @ctask: scsi command task **/ static int iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) { struct iscsi_r2t_info *r2t; struct iscsi_session *session = conn->session; struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data; struct iscsi_tcp_conn *tcp_conn = conn->dd_data; struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr; 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_ctask->exp_datasn != r2tsn){ debug_tcp("%s: ctask->exp_datasn(%d) != rhdr->r2tsn(%d)\n", __FUNCTION__, tcp_ctask->exp_datasn, r2tsn); return ISCSI_ERR_R2TSN; } /* fill-in new R2T associated with the task */ iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr); if (!ctask->sc || session->state != ISCSI_STATE_LOGGED_IN) { iscsi_conn_printk(KERN_INFO, conn, "dropping R2T itt %d in recovery.\n", ctask->itt); return 0; } rc = __kfifo_get(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*)); BUG_ON(!rc); 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_put(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*)); return ISCSI_ERR_DATALEN; } if (r2t->data_length > session->max_burst) debug_scsi("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(ctask->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(ctask->sc)->length); __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*)); return ISCSI_ERR_DATALEN; } r2t->ttt = rhdr->ttt; /* no flip */ r2t->solicit_datasn = 0; iscsi_solicit_data_init(conn, ctask, r2t); tcp_ctask->exp_datasn = r2tsn + 1; __kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*)); conn->r2t_pdus_cnt++; iscsi_requeue_ctask(ctask); 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_session *session = conn->session; struct iscsi_tcp_conn *tcp_conn = conn->dd_data; struct iscsi_cmd_task *ctask; uint32_t itt; /* 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; debug_tcp("opcode 0x%x ahslen %d datalen %d\n", opcode, ahslen, tcp_conn->in.datalen); switch(opcode) { case ISCSI_OP_SCSI_DATA_IN: ctask = session->cmds[itt]; spin_lock(&conn->session->lock); rc = iscsi_data_rsp(conn, ctask); spin_unlock(&conn->session->lock); 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; struct scsi_data_buffer *sdb = scsi_in(ctask->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) 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_segment_seek_sg(&tcp_conn->in.segment, sdb->table.sgl, sdb->table.nents, tcp_ctask->data_offset, tcp_conn->in.datalen, iscsi_tcp_process_data_in, rx_hash); } /* fall through */ 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: ctask = session->cmds[itt]; if (ahslen) rc = ISCSI_ERR_AHSLEN; else if (ctask->sc->sc_data_direction == DMA_TO_DEVICE) { spin_lock(&session->lock); rc = iscsi_r2t_rsp(conn, ctask); spin_unlock(&session->lock); } else rc = ISCSI_ERR_PROTO; 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) { if (segment->digest_len == 0) { 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 - TCP receive in sendfile fashion * @rd_desc: read descriptor * @skb: socket buffer * @offset: offset in skb * @len: skb->len - offset **/ static int iscsi_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len) { struct iscsi_conn *conn = rd_desc->arg.data; 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; 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; } 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) { debug_tcp("no more data avail. Consumed %d\n", consumed); break; } BUG_ON(segment->copied >= segment->size); debug_tcp("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) { debug_tcp("segment done\n"); rc = segment->done(tcp_conn, segment); if (rc != 0) { skb_abort_seq_read(&seq); goto error; } /* The done() functions sets up the * next segment. */ } } skb_abort_seq_read(&seq); conn->rxdata_octets += consumed; return consumed; 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_recv. * We set count to 1 because we want the network layer to * hand us all the skbs that are available. iscsi_tcp_recv * handled pdus that cross buffers or pdus that still need data. */ rd_desc.arg.data = conn; rd_desc.count = 1; tcp_read_sock(sk, &rd_desc, iscsi_tcp_recv); read_unlock(&sk->sk_callback_lock); /* If we had to (atomically) map a highmem page, * unmap it now. */ iscsi_tcp_segment_unmap(&tcp_conn->in.segment); } static void iscsi_tcp_state_change(struct sock *sk) { struct iscsi_tcp_conn *tcp_conn; struct iscsi_conn *conn; struct iscsi_session *session; void (*old_state_change)(struct sock *); read_lock(&sk->sk_callback_lock); conn = (struct iscsi_conn*)sk->sk_user_data; session = conn->session; if ((sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) && !atomic_read(&sk->sk_rmem_alloc)) { debug_tcp("iscsi_tcp_state_change: TCP_CLOSE|TCP_CLOSE_WAIT\n"); iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); } tcp_conn = conn->dd_data; old_state_change = tcp_conn->old_state_change; read_unlock(&sk->sk_callback_lock); old_state_change(sk); } /** * iscsi_write_space - Called when more output buffer space is available * @sk: socket space is available for **/ static void iscsi_write_space(struct sock *sk) { struct iscsi_conn *conn = (struct iscsi_conn*)sk->sk_user_data; struct iscsi_tcp_conn *tcp_conn = conn->dd_data; tcp_conn->old_write_space(sk); debug_tcp("iscsi_write_space: cid %d\n", conn->id); scsi_queue_work(conn->session->host, &conn->xmitwork); } static void iscsi_conn_set_callbacks(struct iscsi_conn *conn) { struct iscsi_tcp_conn *tcp_conn = conn->dd_data; struct sock *sk = tcp_conn->sock->sk; /* assign new callbacks */ write_lock_bh(&sk->sk_callback_lock); sk->sk_user_data = conn; tcp_conn->old_data_ready = sk->sk_data_ready; tcp_conn->old_state_change = sk->sk_state_change; tcp_conn->old_write_space = sk->sk_write_space; sk->sk_data_ready = iscsi_tcp_data_ready; sk->sk_state_change = iscsi_tcp_state_change; sk->sk_write_space = iscsi_write_space; write_unlock_bh(&sk->sk_callback_lock); } static void iscsi_conn_restore_callbacks(struct iscsi_tcp_conn *tcp_conn) { struct sock *sk = tcp_conn->sock->sk; /* restore socket callbacks, see also: iscsi_conn_set_callbacks() */ write_lock_bh(&sk->sk_callback_lock); sk->sk_user_data = NULL; sk->sk_data_ready = tcp_conn->old_data_ready; sk->sk_state_change = tcp_conn->old_state_change; sk->sk_write_space = tcp_conn->old_write_space; sk->sk_no_check = 0; write_unlock_bh(&sk->sk_callback_lock); } /** * iscsi_xmit - TCP transmit **/ static int iscsi_xmit(struct iscsi_conn *conn) { struct iscsi_tcp_conn *tcp_conn = conn->dd_data; struct iscsi_segment *segment = &tcp_conn->out.segment; unsigned int consumed = 0; int rc = 0; while (1) { rc = iscsi_tcp_xmit_segment(tcp_conn, segment); if (rc < 0) goto error; if (rc == 0) break; consumed += rc; if (segment->total_copied >= segment->total_size) { if (segment->done != NULL) { rc = segment->done(tcp_conn, segment); if (rc < 0) goto error; } } } debug_tcp("xmit %d bytes\n", consumed); conn->txdata_octets += consumed; return consumed; error: /* Transmit error. We could initiate error recovery * here. */ debug_tcp("Error sending PDU, errno=%d\n", rc); iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); return rc; } /** * iscsi_tcp_xmit_qlen - return the number of bytes queued for xmit */ static inline int iscsi_tcp_xmit_qlen(struct iscsi_conn *conn) { struct iscsi_tcp_conn *tcp_conn = conn->dd_data; struct iscsi_segment *segment = &tcp_conn->out.segment; return segment->total_copied - segment->total_size; } static inline int iscsi_tcp_flush(struct iscsi_conn *conn) { int rc; while (iscsi_tcp_xmit_qlen(conn)) { rc = iscsi_xmit(conn); if (rc == 0) return -EAGAIN; if (rc < 0) return rc; } return 0; } /* * This is called when we're done sending the header. * Simply copy the data_segment to the send segment, and return. */ static int iscsi_tcp_send_hdr_done(struct iscsi_tcp_conn *tcp_conn, struct iscsi_segment *segment) { tcp_conn->out.segment = tcp_conn->out.data_segment; debug_tcp("Header done. Next segment size %u total_size %u\n", tcp_conn->out.segment.size, tcp_conn->out.segment.total_size); return 0; } static void iscsi_tcp_send_hdr_prep(struct iscsi_conn *conn, void *hdr, size_t hdrlen) { struct iscsi_tcp_conn *tcp_conn = conn->dd_data; debug_tcp("%s(%p%s)\n", __FUNCTION__, tcp_conn, conn->hdrdgst_en? ", digest enabled" : ""); /* Clear the data segment - needs to be filled in by the * caller using iscsi_tcp_send_data_prep() */ memset(&tcp_conn->out.data_segment, 0, sizeof(struct iscsi_segment)); /* If header digest is enabled, compute the CRC and * place the digest into the same buffer. We make * sure that both iscsi_tcp_ctask and mtask have * sufficient room. */ if (conn->hdrdgst_en) { iscsi_tcp_dgst_header(&tcp_conn->tx_hash, hdr, hdrlen, hdr + hdrlen); hdrlen += ISCSI_DIGEST_SIZE; } /* Remember header pointer for later, when we need * to decide whether there's a payload to go along * with the header. */ tcp_conn->out.hdr = hdr; iscsi_segment_init_linear(&tcp_conn->out.segment, hdr, hdrlen, iscsi_tcp_send_hdr_done, NULL); } /* * Prepare the send buffer for the payload data. * Padding and checksumming will all be taken care * of by the iscsi_segment routines. */ static int iscsi_tcp_send_data_prep(struct iscsi_conn *conn, struct scatterlist *sg, unsigned int count, unsigned int offset, unsigned int len) { struct iscsi_tcp_conn *tcp_conn = conn->dd_data; struct hash_desc *tx_hash = NULL; unsigned int hdr_spec_len; debug_tcp("%s(%p, offset=%d, datalen=%d%s)\n", __FUNCTION__, tcp_conn, offset, len, conn->datadgst_en? ", digest enabled" : ""); /* Make sure the datalen matches what the caller said he would send. */ hdr_spec_len = ntoh24(tcp_conn->out.hdr->dlength); WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); if (conn->datadgst_en) tx_hash = &tcp_conn->tx_hash; return iscsi_segment_seek_sg(&tcp_conn->out.data_segment, sg, count, offset, len, NULL, tx_hash); } static void iscsi_tcp_send_linear_data_prepare(struct iscsi_conn *conn, void *data, size_t len) { struct iscsi_tcp_conn *tcp_conn = conn->dd_data; struct hash_desc *tx_hash = NULL; unsigned int hdr_spec_len; debug_tcp("%s(%p, datalen=%d%s)\n", __FUNCTION__, tcp_conn, len, conn->datadgst_en? ", digest enabled" : ""); /* Make sure the datalen matches what the caller said he would send. */ hdr_spec_len = ntoh24(tcp_conn->out.hdr->dlength); WARN_ON(iscsi_padded(len) != iscsi_padded(hdr_spec_len)); if (conn->datadgst_en) tx_hash = &tcp_conn->tx_hash; iscsi_segment_init_linear(&tcp_conn->out.data_segment, data, len, NULL, tx_hash); } /** * iscsi_solicit_data_cont - initialize next Data-Out * @conn: iscsi connection * @ctask: scsi command task * @r2t: R2T info * @left: bytes left to transfer * * Notes: * Initialize next Data-Out within this R2T sequence and continue * to process next Scatter-Gather element(if any) of this SCSI command. * * Called under connection lock. **/ static int iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask, struct iscsi_r2t_info *r2t) { struct iscsi_data *hdr; int new_offset, left; BUG_ON(r2t->data_length - r2t->sent < 0); left = r2t->data_length - r2t->sent; if (left == 0) return 0; hdr = &r2t->dtask.hdr; memset(hdr, 0, sizeof(struct iscsi_data)); hdr->ttt = r2t->ttt; hdr->datasn = cpu_to_be32(r2t->solicit_datasn); r2t->solicit_datasn++; hdr->opcode = ISCSI_OP_SCSI_DATA_OUT; memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun)); hdr->itt = ctask->hdr->itt; hdr->exp_statsn = r2t->exp_statsn; new_offset = r2t->data_offset + r2t->sent; hdr->offset = cpu_to_be32(new_offset); if (left > conn->max_xmit_dlength) { hton24(hdr->dlength, conn->max_xmit_dlength); r2t->data_count = conn->max_xmit_dlength; } else { hton24(hdr->dlength, left); r2t->data_count = left; hdr->flags = ISCSI_FLAG_CMD_FINAL; } conn->dataout_pdus_cnt++; return 1; } /** * iscsi_tcp_ctask - Initialize iSCSI SCSI_READ or SCSI_WRITE commands * @conn: iscsi connection * @ctask: scsi command task * @sc: scsi command **/ static int iscsi_tcp_ctask_init(struct iscsi_cmd_task *ctask) { struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data; struct iscsi_conn *conn = ctask->conn; struct scsi_cmnd *sc = ctask->sc; int err; BUG_ON(__kfifo_len(tcp_ctask->r2tqueue)); tcp_ctask->sent = 0; tcp_ctask->exp_datasn = 0; /* Prepare PDU, optionally w/ immediate data */ debug_scsi("ctask deq [cid %d itt 0x%x imm %d unsol %d]\n", conn->id, ctask->itt, ctask->imm_count, ctask->unsol_count); iscsi_tcp_send_hdr_prep(conn, ctask->hdr, ctask->hdr_len); if (!ctask->imm_count) return 0; /* If we have immediate data, attach a payload */ err = iscsi_tcp_send_data_prep(conn, scsi_out(sc)->table.sgl, scsi_out(sc)->table.nents, 0, ctask->imm_count); if (err) return err; tcp_ctask->sent += ctask->imm_count; ctask->imm_count = 0; return 0; } /** * iscsi_tcp_mtask_xmit - xmit management(immediate) task * @conn: iscsi connection * @mtask: task management task * * Notes: * The function can return -EAGAIN in which case caller must * call it again later, or recover. '0' return code means successful * xmit. **/ static int iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask) { int rc; /* Flush any pending data first. */ rc = iscsi_tcp_flush(conn); if (rc < 0) return rc; if (mtask->hdr->itt == RESERVED_ITT) { struct iscsi_session *session = conn->session; spin_lock_bh(&session->lock); iscsi_free_mgmt_task(conn, mtask); spin_unlock_bh(&session->lock); } return 0; } /* * iscsi_tcp_ctask_xmit - xmit normal PDU task * @conn: iscsi connection * @ctask: iscsi command task * * We're expected to return 0 when everything was transmitted succesfully, * -EAGAIN if there's still data in the queue, or != 0 for any other kind * of error. */ static int iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) { struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data; struct scsi_cmnd *sc = ctask->sc; struct scsi_data_buffer *sdb = scsi_out(sc); int rc = 0; flush: /* Flush any pending data first. */ rc = iscsi_tcp_flush(conn); if (rc < 0) return rc; /* Are we done already? */ if (sc->sc_data_direction != DMA_TO_DEVICE) return 0; if (ctask->unsol_count != 0) { struct iscsi_data *hdr = &tcp_ctask->unsol_dtask.hdr; /* Prepare a header for the unsolicited PDU. * The amount of data we want to send will be * in ctask->data_count. * FIXME: return the data count instead. */ iscsi_prep_unsolicit_data_pdu(ctask, hdr); debug_tcp("unsol dout [itt 0x%x doff %d dlen %d]\n", ctask->itt, tcp_ctask->sent, ctask->data_count); iscsi_tcp_send_hdr_prep(conn, hdr, sizeof(*hdr)); rc = iscsi_tcp_send_data_prep(conn, sdb->table.sgl, sdb->table.nents, tcp_ctask->sent, ctask->data_count); if (rc) goto fail; tcp_ctask->sent += ctask->data_count; ctask->unsol_count -= ctask->data_count; goto flush; } else { struct iscsi_session *session = conn->session; struct iscsi_r2t_info *r2t; /* All unsolicited PDUs sent. Check for solicited PDUs. */ spin_lock_bh(&session->lock); r2t = tcp_ctask->r2t; if (r2t != NULL) { /* Continue with this R2T? */ if (!iscsi_solicit_data_cont(conn, ctask, r2t)) { debug_scsi(" done with r2t %p\n", r2t); __kfifo_put(tcp_ctask->r2tpool.queue, (void*)&r2t, sizeof(void*)); tcp_ctask->r2t = r2t = NULL; } } if (r2t == NULL) { __kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t, sizeof(void*)); r2t = tcp_ctask->r2t; } spin_unlock_bh(&session->lock); /* Waiting for more R2Ts to arrive. */ if (r2t == NULL) { debug_tcp("no R2Ts yet\n"); return 0; } debug_scsi("sol dout %p [dsn %d itt 0x%x doff %d dlen %d]\n", r2t, r2t->solicit_datasn - 1, ctask->itt, r2t->data_offset + r2t->sent, r2t->data_count); iscsi_tcp_send_hdr_prep(conn, &r2t->dtask.hdr, sizeof(struct iscsi_hdr)); rc = iscsi_tcp_send_data_prep(conn, sdb->table.sgl, sdb->table.nents, r2t->data_offset + r2t->sent, r2t->data_count); if (rc) goto fail; tcp_ctask->sent += r2t->data_count; r2t->sent += r2t->data_count; goto flush; } return 0; fail: iscsi_conn_failure(conn, rc); return -EIO; } static struct iscsi_cls_conn * iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx) { struct iscsi_conn *conn; struct iscsi_cls_conn *cls_conn; struct iscsi_tcp_conn *tcp_conn; cls_conn = iscsi_conn_setup(cls_session, 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 = kzalloc(sizeof(*tcp_conn), GFP_KERNEL); if (!tcp_conn) goto tcp_conn_alloc_fail; conn->dd_data = tcp_conn; tcp_conn->iscsi_conn = conn; tcp_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0, CRYPTO_ALG_ASYNC); tcp_conn->tx_hash.flags = 0; if (IS_ERR(tcp_conn->tx_hash.tfm)) goto free_tcp_conn; tcp_conn->rx_hash.tfm = crypto_alloc_hash("crc32c", 0, CRYPTO_ALG_ASYNC); tcp_conn->rx_hash.flags = 0; if (IS_ERR(tcp_conn->rx_hash.tfm)) goto free_tx_tfm; return cls_conn; free_tx_tfm: crypto_free_hash(tcp_conn->tx_hash.tfm); free_tcp_conn: iscsi_conn_printk(KERN_ERR, conn, "Could not create connection due to crc32c " "loading error. Make sure the crc32c " "module is built as a module or into the " "kernel\n"); kfree(tcp_conn); tcp_conn_alloc_fail: iscsi_conn_teardown(cls_conn); return NULL; } static void iscsi_tcp_release_conn(struct iscsi_conn *conn) { struct iscsi_session *session = conn->session; struct iscsi_tcp_conn *tcp_conn = conn->dd_data; struct socket *sock = tcp_conn->sock; if (!sock) return; sock_hold(sock->sk); iscsi_conn_restore_callbacks(tcp_conn); sock_put(sock->sk); spin_lock_bh(&session->lock); tcp_conn->sock = NULL; conn->recv_lock = NULL; spin_unlock_bh(&session->lock); sockfd_put(sock); } static void iscsi_tcp_conn_destroy(struct iscsi_cls_conn *cls_conn) { struct iscsi_conn *conn = cls_conn->dd_data; struct iscsi_tcp_conn *tcp_conn = conn->dd_data; iscsi_tcp_release_conn(conn); iscsi_conn_teardown(cls_conn); if (tcp_conn->tx_hash.tfm) crypto_free_hash(tcp_conn->tx_hash.tfm); if (tcp_conn->rx_hash.tfm) crypto_free_hash(tcp_conn->rx_hash.tfm); kfree(tcp_conn); } static void iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) { struct iscsi_conn *conn = cls_conn->dd_data; iscsi_conn_stop(cls_conn, flag); iscsi_tcp_release_conn(conn); } static int iscsi_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock, char *buf, int *port, int (*getname)(struct socket *, struct sockaddr *, int *addrlen)) { struct sockaddr_storage *addr; struct sockaddr_in6 *sin6; struct sockaddr_in *sin; int rc = 0, len; addr = kmalloc(sizeof(*addr), GFP_KERNEL); if (!addr) return -ENOMEM; if (getname(sock, (struct sockaddr *) addr, &len)) { rc = -ENODEV; goto free_addr; } switch (addr->ss_family) { case AF_INET: sin = (struct sockaddr_in *)addr; spin_lock_bh(&conn->session->lock); sprintf(buf, NIPQUAD_FMT, NIPQUAD(sin->sin_addr.s_addr)); *port = be16_to_cpu(sin->sin_port); spin_unlock_bh(&conn->session->lock); break; case AF_INET6: sin6 = (struct sockaddr_in6 *)addr; spin_lock_bh(&conn->session->lock); sprintf(buf, NIP6_FMT, NIP6(sin6->sin6_addr)); *port = be16_to_cpu(sin6->sin6_port); spin_unlock_bh(&conn->session->lock); break; } free_addr: kfree(addr); return rc; } static int iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session, struct iscsi_cls_conn *cls_conn, uint64_t transport_eph, int is_leading) { struct iscsi_conn *conn = cls_conn->dd_data; struct iscsi_tcp_conn *tcp_conn = conn->dd_data; struct sock *sk; struct socket *sock; int err; /* lookup for existing socket */ sock = sockfd_lookup((int)transport_eph, &err); if (!sock) { iscsi_conn_printk(KERN_ERR, conn, "sockfd_lookup failed %d\n", err); return -EEXIST; } /* * copy these values now because if we drop the session * userspace may still want to query the values since we will * be using them for the reconnect */ err = iscsi_tcp_get_addr(conn, sock, conn->portal_address, &conn->portal_port, kernel_getpeername); if (err) goto free_socket; err = iscsi_tcp_get_addr(conn, sock, conn->local_address, &conn->local_port, kernel_getsockname); if (err) goto free_socket; err = iscsi_conn_bind(cls_session, cls_conn, is_leading); if (err) goto free_socket; /* bind iSCSI connection and socket */ tcp_conn->sock = sock; /* setup Socket parameters */ sk = sock->sk; sk->sk_reuse = 1; sk->sk_sndtimeo = 15 * HZ; /* FIXME: make it configurable */ sk->sk_allocation = GFP_ATOMIC; /* FIXME: disable Nagle's algorithm */ /* * Intercept TCP callbacks for sendfile like receive * processing. */ conn->recv_lock = &sk->sk_callback_lock; iscsi_conn_set_callbacks(conn); tcp_conn->sendpage = tcp_conn->sock->ops->sendpage; /* * set receive state machine into initial state */ iscsi_tcp_hdr_recv_prep(tcp_conn); return 0; free_socket: sockfd_put(sock); return err; } /* called with host lock */ static void iscsi_tcp_mtask_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask) { debug_scsi("mtask deq [cid %d itt 0x%x]\n", conn->id, mtask->itt); /* Prepare PDU, optionally w/ immediate data */ iscsi_tcp_send_hdr_prep(conn, mtask->hdr, sizeof(*mtask->hdr)); /* If we have immediate data, attach a payload */ if (mtask->data_count) iscsi_tcp_send_linear_data_prepare(conn, mtask->data, mtask->data_count); } static int iscsi_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_cmd_task *ctask = session->cmds[cmd_i]; struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data; /* * pre-allocated x4 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_ctask->r2tpool, session->max_r2t * 4, NULL, sizeof(struct iscsi_r2t_info))) { goto r2t_alloc_fail; } /* R2T xmit queue */ tcp_ctask->r2tqueue = kfifo_alloc( session->max_r2t * 4 * sizeof(void*), GFP_KERNEL, NULL); if (tcp_ctask->r2tqueue == ERR_PTR(-ENOMEM)) { iscsi_pool_free(&tcp_ctask->r2tpool); goto r2t_alloc_fail; } } return 0; r2t_alloc_fail: for (i = 0; i < cmd_i; i++) { struct iscsi_cmd_task *ctask = session->cmds[i]; struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data; kfifo_free(tcp_ctask->r2tqueue); iscsi_pool_free(&tcp_ctask->r2tpool); } return -ENOMEM; } static void iscsi_r2tpool_free(struct iscsi_session *session) { int i; for (i = 0; i < session->cmds_max; i++) { struct iscsi_cmd_task *ctask = session->cmds[i]; struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data; kfifo_free(tcp_ctask->r2tqueue); iscsi_pool_free(&tcp_ctask->r2tpool); } } static int iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param, char *buf, int buflen) { struct iscsi_conn *conn = cls_conn->dd_data; struct iscsi_session *session = conn->session; struct iscsi_tcp_conn *tcp_conn = conn->dd_data; int value; switch(param) { case ISCSI_PARAM_HDRDGST_EN: iscsi_set_param(cls_conn, param, buf, buflen); break; case ISCSI_PARAM_DATADGST_EN: iscsi_set_param(cls_conn, param, buf, buflen); tcp_conn->sendpage = conn->datadgst_en ? sock_no_sendpage : tcp_conn->sock->ops->sendpage; break; case ISCSI_PARAM_MAX_R2T: sscanf(buf, "%d", &value); if (value <= 0 || !is_power_of_2(value)) return -EINVAL; if (session->max_r2t == value) break; iscsi_r2tpool_free(session); iscsi_set_param(cls_conn, param, buf, buflen); if (iscsi_r2tpool_alloc(session)) return -ENOMEM; break; default: return iscsi_set_param(cls_conn, param, buf, buflen); } return 0; } static int iscsi_tcp_conn_get_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param, char *buf) { struct iscsi_conn *conn = cls_conn->dd_data; int len; switch(param) { case ISCSI_PARAM_CONN_PORT: spin_lock_bh(&conn->session->lock); len = sprintf(buf, "%hu\n", conn->portal_port); spin_unlock_bh(&conn->session->lock); break; case ISCSI_PARAM_CONN_ADDRESS: spin_lock_bh(&conn->session->lock); len = sprintf(buf, "%s\n", conn->portal_address); spin_unlock_bh(&conn->session->lock); break; default: return iscsi_conn_get_param(cls_conn, param, buf); } return len; } static int iscsi_tcp_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param, char *buf) { struct iscsi_session *session = iscsi_hostdata(shost->hostdata); int len; switch (param) { case ISCSI_HOST_PARAM_IPADDRESS: spin_lock_bh(&session->lock); if (!session->leadconn) len = -ENODEV; else len = sprintf(buf, "%s\n", session->leadconn->local_address); spin_unlock_bh(&session->lock); break; default: return iscsi_host_get_param(shost, param, buf); } return len; } static void iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats) { struct iscsi_conn *conn = cls_conn->dd_data; struct iscsi_tcp_conn *tcp_conn = conn->dd_data; 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; stats->custom_length = 3; strcpy(stats->custom[0].desc, "tx_sendpage_failures"); stats->custom[0].value = tcp_conn->sendpage_failures_cnt; strcpy(stats->custom[1].desc, "rx_discontiguous_hdr"); stats->custom[1].value = tcp_conn->discontiguous_hdr_cnt; strcpy(stats->custom[2].desc, "eh_abort_cnt"); stats->custom[2].value = conn->eh_abort_cnt; } static struct iscsi_cls_session * iscsi_tcp_session_create(struct iscsi_transport *iscsit, struct scsi_transport_template *scsit, uint16_t cmds_max, uint16_t qdepth, uint32_t initial_cmdsn, uint32_t *hostno) { struct iscsi_cls_session *cls_session; struct iscsi_session *session; uint32_t hn; int cmd_i; cls_session = iscsi_session_setup(iscsit, scsit, cmds_max, qdepth, sizeof(struct iscsi_tcp_cmd_task), sizeof(struct iscsi_tcp_mgmt_task), initial_cmdsn, &hn); if (!cls_session) return NULL; *hostno = hn; session = class_to_transport_session(cls_session); for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) { struct iscsi_cmd_task *ctask = session->cmds[cmd_i]; struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data; ctask->hdr = &tcp_ctask->hdr.cmd_hdr; ctask->hdr_max = sizeof(tcp_ctask->hdr) - ISCSI_DIGEST_SIZE; } for (cmd_i = 0; cmd_i < session->mgmtpool_max; cmd_i++) { struct iscsi_mgmt_task *mtask = session->mgmt_cmds[cmd_i]; struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data; mtask->hdr = (struct iscsi_hdr *) &tcp_mtask->hdr; } if (iscsi_r2tpool_alloc(class_to_transport_session(cls_session))) goto r2tpool_alloc_fail; return cls_session; r2tpool_alloc_fail: iscsi_session_teardown(cls_session); return NULL; } static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session) { iscsi_r2tpool_free(class_to_transport_session(cls_session)); iscsi_session_teardown(cls_session); } static int iscsi_tcp_slave_configure(struct scsi_device *sdev) { blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_ANY); blk_queue_dma_alignment(sdev->request_queue, 0); return 0; } static struct scsi_host_template iscsi_sht = { .module = THIS_MODULE, .name = "iSCSI Initiator over TCP/IP", .queuecommand = iscsi_queuecommand, .change_queue_depth = iscsi_change_queue_depth, .can_queue = ISCSI_DEF_XMIT_CMDS_MAX - 1, .sg_tablesize = 4096, .max_sectors = 0xFFFF, .cmd_per_lun = ISCSI_DEF_CMD_PER_LUN, .eh_abort_handler = iscsi_eh_abort, .eh_device_reset_handler= iscsi_eh_device_reset, .eh_host_reset_handler = iscsi_eh_host_reset, .use_clustering = DISABLE_CLUSTERING, .slave_configure = iscsi_tcp_slave_configure, .proc_name = "iscsi_tcp", .this_id = -1, }; static struct iscsi_transport iscsi_tcp_transport = { .owner = THIS_MODULE, .name = "tcp", .caps = CAP_RECOVERY_L0 | CAP_MULTI_R2T | CAP_HDRDGST | CAP_DATADGST, .param_mask = ISCSI_MAX_RECV_DLENGTH | ISCSI_MAX_XMIT_DLENGTH | ISCSI_HDRDGST_EN | ISCSI_DATADGST_EN | ISCSI_INITIAL_R2T_EN | ISCSI_MAX_R2T | ISCSI_IMM_DATA_EN | ISCSI_FIRST_BURST | ISCSI_MAX_BURST | ISCSI_PDU_INORDER_EN | ISCSI_DATASEQ_INORDER_EN | ISCSI_ERL | ISCSI_CONN_PORT | ISCSI_CONN_ADDRESS | ISCSI_EXP_STATSN | ISCSI_PERSISTENT_PORT | ISCSI_PERSISTENT_ADDRESS | ISCSI_TARGET_NAME | ISCSI_TPGT | ISCSI_USERNAME | ISCSI_PASSWORD | ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN | ISCSI_FAST_ABORT | ISCSI_ABORT_TMO | ISCSI_LU_RESET_TMO | ISCSI_PING_TMO | ISCSI_RECV_TMO, .host_param_mask = ISCSI_HOST_HWADDRESS | ISCSI_HOST_IPADDRESS | ISCSI_HOST_INITIATOR_NAME | ISCSI_HOST_NETDEV_NAME, .host_template = &iscsi_sht, .conndata_size = sizeof(struct iscsi_conn), .max_conn = 1, .max_cmd_len = 16, /* session management */ .create_session = iscsi_tcp_session_create, .destroy_session = iscsi_tcp_session_destroy, /* connection management */ .create_conn = iscsi_tcp_conn_create, .bind_conn = iscsi_tcp_conn_bind, .destroy_conn = iscsi_tcp_conn_destroy, .set_param = iscsi_conn_set_param, .get_conn_param = iscsi_tcp_conn_get_param, .get_session_param = iscsi_session_get_param, .start_conn = iscsi_conn_start, .stop_conn = iscsi_tcp_conn_stop, /* iscsi host params */ .get_host_param = iscsi_tcp_host_get_param, .set_host_param = iscsi_host_set_param, /* IO */ .send_pdu = iscsi_conn_send_pdu, .get_stats = iscsi_conn_get_stats, .init_cmd_task = iscsi_tcp_ctask_init, .init_mgmt_task = iscsi_tcp_mtask_init, .xmit_cmd_task = iscsi_tcp_ctask_xmit, .xmit_mgmt_task = iscsi_tcp_mtask_xmit, .cleanup_cmd_task = iscsi_tcp_cleanup_ctask, /* recovery */ .session_recovery_timedout = iscsi_session_recovery_timedout, }; static int __init iscsi_tcp_init(void) { if (iscsi_max_lun < 1) { printk(KERN_ERR "iscsi_tcp: Invalid max_lun value of %u\n", iscsi_max_lun); return -EINVAL; } iscsi_tcp_transport.max_lun = iscsi_max_lun; if (!iscsi_register_transport(&iscsi_tcp_transport)) return -ENODEV; return 0; } static void __exit iscsi_tcp_exit(void) { iscsi_unregister_transport(&iscsi_tcp_transport); } module_init(iscsi_tcp_init); module_exit(iscsi_tcp_exit);