diff options
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/scsi/iscsi_tcp.c | 1018 | ||||
-rw-r--r-- | drivers/scsi/iscsi_tcp.h | 66 |
2 files changed, 548 insertions, 536 deletions
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c index 4b226b88b68..1b540e03f5b 100644 --- a/drivers/scsi/iscsi_tcp.c +++ b/drivers/scsi/iscsi_tcp.c @@ -48,7 +48,7 @@ MODULE_AUTHOR("Dmitry Yusupov <dmitry_yus@yahoo.com>, " "Alex Aizman <itn780@yahoo.com>"); MODULE_DESCRIPTION("iSCSI/TCP data-path"); MODULE_LICENSE("GPL"); -/* #define DEBUG_TCP */ +#undef DEBUG_TCP #define DEBUG_ASSERT #ifdef DEBUG_TCP @@ -67,10 +67,15 @@ MODULE_LICENSE("GPL"); static unsigned int iscsi_max_lun = 512; module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO); +static int iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn, + struct iscsi_chunk *chunk); + static inline void iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size) { - sg_init_one(&ibuf->sg, vbuf, size); + ibuf->sg.page = virt_to_page(vbuf); + ibuf->sg.offset = offset_in_page(vbuf); + ibuf->sg.length = size; ibuf->sent = 0; ibuf->use_sendmsg = 1; } @@ -78,12 +83,13 @@ iscsi_buf_init_iov(struct iscsi_buf *ibuf, char *vbuf, int size) static inline void iscsi_buf_init_sg(struct iscsi_buf *ibuf, struct scatterlist *sg) { - sg_init_table(&ibuf->sg, 1); - sg_set_page(&ibuf->sg, sg_page(sg), sg->length, sg->offset); + ibuf->sg.page = sg->page; + ibuf->sg.offset = sg->offset; + ibuf->sg.length = sg->length; /* * Fastpath: sg element fits into single page */ - if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg_page(sg))) + if (sg->length + sg->offset <= PAGE_SIZE && !PageSlab(sg->page)) ibuf->use_sendmsg = 0; else ibuf->use_sendmsg = 1; @@ -110,72 +116,331 @@ iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf, buf->sg.length += sizeof(u32); } +/* + * Scatterlist handling: inside the iscsi_chunk, we + * remember an index into the scatterlist, and set data/size + * to the current scatterlist entry. For highmem pages, we + * kmap as needed. + * + * Note that the page is unmapped when we return from + * TCP's data_ready handler, so we may end up mapping and + * unmapping the same page repeatedly. The whole reason + * for this is that we shouldn't keep the page mapped + * outside the softirq. + */ + +/** + * iscsi_tcp_chunk_init_sg - init indicated scatterlist entry + * @chunk: the buffer object + * @idx: index into scatterlist + * @offset: byte offset into that sg entry + * + * This function sets up the chunk so that subsequent + * data is copied to the indicated sg entry, at the given + * offset. + */ +static inline void +iscsi_tcp_chunk_init_sg(struct iscsi_chunk *chunk, + unsigned int idx, unsigned int offset) +{ + struct scatterlist *sg; + + BUG_ON(chunk->sg == NULL); + + sg = &chunk->sg[idx]; + chunk->sg_index = idx; + chunk->sg_offset = offset; + chunk->size = min(sg->length - offset, chunk->total_size); + chunk->data = NULL; +} + +/** + * iscsi_tcp_chunk_map - map the current S/G page + * @chunk: iscsi chunk + * + * We only need to possibly kmap data if scatter lists are being used, + * because the iscsi passthrough and internal IO paths will never use high + * mem pages. + */ +static inline void +iscsi_tcp_chunk_map(struct iscsi_chunk *chunk) +{ + struct scatterlist *sg; + + if (chunk->data != NULL || !chunk->sg) + return; + + sg = &chunk->sg[chunk->sg_index]; + BUG_ON(chunk->sg_mapped); + BUG_ON(sg->length == 0); + chunk->sg_mapped = kmap_atomic(sg->page, KM_SOFTIRQ0); + chunk->data = chunk->sg_mapped + sg->offset + chunk->sg_offset; +} + +static inline void +iscsi_tcp_chunk_unmap(struct iscsi_chunk *chunk) +{ + if (chunk->sg_mapped) { + kunmap_atomic(chunk->sg_mapped, KM_SOFTIRQ0); + chunk->sg_mapped = NULL; + chunk->data = NULL; + } +} + +/* + * Splice the digest buffer into the buffer + */ +static inline void +iscsi_tcp_chunk_splice_digest(struct iscsi_chunk *chunk, void *digest) +{ + chunk->data = digest; + chunk->digest_len = ISCSI_DIGEST_SIZE; + chunk->total_size += ISCSI_DIGEST_SIZE; + chunk->size = ISCSI_DIGEST_SIZE; + chunk->copied = 0; + chunk->sg = NULL; + chunk->sg_index = 0; + chunk->hash = NULL; +} + +/** + * iscsi_tcp_chunk_done - check whether the chunk is complete + * @chunk: iscsi chunk to check + * + * Check if we're done receiving this chunk. If the receive + * buffer is full but we expect more data, move on to the + * next entry in the scatterlist. + * + * If the amount of data we received isn't a multiple of 4, + * we will transparently receive the pad bytes, too. + * + * This function must be re-entrant. + */ static inline int -iscsi_hdr_extract(struct iscsi_tcp_conn *tcp_conn) +iscsi_tcp_chunk_done(struct iscsi_chunk *chunk) { - struct sk_buff *skb = tcp_conn->in.skb; + static unsigned char padbuf[ISCSI_PAD_LEN]; + + if (chunk->copied < chunk->size) { + iscsi_tcp_chunk_map(chunk); + return 0; + } - tcp_conn->in.zero_copy_hdr = 0; + chunk->total_copied += chunk->copied; + chunk->copied = 0; + chunk->size = 0; - if (tcp_conn->in.copy >= tcp_conn->hdr_size && - tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) { - /* - * Zero-copy PDU Header: using connection context - * to store header pointer. - */ - if (skb_shinfo(skb)->frag_list == NULL && - !skb_shinfo(skb)->nr_frags) { - tcp_conn->in.hdr = (struct iscsi_hdr *) - ((char*)skb->data + tcp_conn->in.offset); - tcp_conn->in.zero_copy_hdr = 1; - } else { - /* ignoring return code since we checked - * in.copy before */ - skb_copy_bits(skb, tcp_conn->in.offset, - &tcp_conn->hdr, tcp_conn->hdr_size); - tcp_conn->in.hdr = &tcp_conn->hdr; + /* Unmap the current scatterlist page, if there is one. */ + iscsi_tcp_chunk_unmap(chunk); + + /* Do we have more scatterlist entries? */ + if (chunk->total_copied < chunk->total_size) { + /* Proceed to the next entry in the scatterlist. */ + iscsi_tcp_chunk_init_sg(chunk, chunk->sg_index + 1, 0); + iscsi_tcp_chunk_map(chunk); + BUG_ON(chunk->size == 0); + return 0; + } + + /* Do we need to handle padding? */ + if (chunk->total_copied & (ISCSI_PAD_LEN-1)) { + unsigned int pad; + + pad = ISCSI_PAD_LEN - (chunk->total_copied & (ISCSI_PAD_LEN-1)); + debug_tcp("consume %d pad bytes\n", pad); + chunk->total_size += pad; + chunk->size = pad; + chunk->data = padbuf; + return 0; + } + + /* + * Set us up for receiving the data digest. hdr digest + * is completely handled in hdr done function. + */ + if (chunk->hash) { + if (chunk->digest_len == 0) { + crypto_hash_final(chunk->hash, chunk->digest); + iscsi_tcp_chunk_splice_digest(chunk, + chunk->recv_digest); + return 0; } - tcp_conn->in.offset += tcp_conn->hdr_size; - tcp_conn->in.copy -= tcp_conn->hdr_size; - } else { - int hdr_remains; - int copylen; + } - /* - * PDU header scattered across SKB's, - * copying it... This'll happen quite rarely. - */ + return 1; +} + +/** + * iscsi_tcp_chunk_recv - copy data to chunk + * @tcp_conn: the iSCSI TCP connection + * @chunk: the buffer to copy to + * @ptr: data pointer + * @len: amount of data available + * + * This function copies up to @len bytes to the + * given buffer, and returns the number of bytes + * consumed, which can actually be less than @len. + * + * If hash digest is enabled, the function will update the + * hash while copying. + * Combining these two operations doesn't buy us a lot (yet), + * but in the future we could implement combined copy+crc, + * just way we do for network layer checksums. + */ +static int +iscsi_tcp_chunk_recv(struct iscsi_tcp_conn *tcp_conn, + struct iscsi_chunk *chunk, const void *ptr, + unsigned int len) +{ + struct scatterlist sg; + unsigned int copy, copied = 0; + + while (!iscsi_tcp_chunk_done(chunk)) { + if (copied == len) + goto out; + + copy = min(len - copied, chunk->size - chunk->copied); + memcpy(chunk->data + chunk->copied, ptr + copied, copy); + + if (chunk->hash) { + sg_init_one(&sg, ptr + copied, copy); + crypto_hash_update(chunk->hash, &sg, copy); + } + chunk->copied += copy; + copied += copy; + } + +out: + return copied; +} - if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER) - tcp_conn->in.hdr_offset = 0; +static inline void +iscsi_tcp_dgst_header(struct hash_desc *hash, const void *hdr, size_t hdrlen, + unsigned char digest[ISCSI_DIGEST_SIZE]) +{ + struct scatterlist sg; + + sg_init_one(&sg, hdr, hdrlen); + crypto_hash_digest(hash, &sg, hdrlen, digest); +} + +static inline int +iscsi_tcp_dgst_verify(struct iscsi_tcp_conn *tcp_conn, + struct iscsi_chunk *chunk) +{ + if (!chunk->digest_len) + return 1; + + if (memcmp(chunk->recv_digest, chunk->digest, chunk->digest_len)) { + debug_scsi("digest mismatch\n"); + return 0; + } - hdr_remains = tcp_conn->hdr_size - tcp_conn->in.hdr_offset; - BUG_ON(hdr_remains <= 0); + return 1; +} - copylen = min(tcp_conn->in.copy, hdr_remains); - skb_copy_bits(skb, tcp_conn->in.offset, - (char*)&tcp_conn->hdr + tcp_conn->in.hdr_offset, - copylen); +/* + * Helper function to set up chunk buffer + */ +static inline void +__iscsi_chunk_init(struct iscsi_chunk *chunk, size_t size, + iscsi_chunk_done_fn_t *done, struct hash_desc *hash) +{ + memset(chunk, 0, sizeof(*chunk)); + chunk->total_size = size; + chunk->done = done; - debug_tcp("PDU gather offset %d bytes %d in.offset %d " - "in.copy %d\n", tcp_conn->in.hdr_offset, copylen, - tcp_conn->in.offset, tcp_conn->in.copy); + if (hash) { + chunk->hash = hash; + crypto_hash_init(hash); + } +} - tcp_conn->in.offset += copylen; - tcp_conn->in.copy -= copylen; - if (copylen < hdr_remains) { - tcp_conn->in_progress = IN_PROGRESS_HEADER_GATHER; - tcp_conn->in.hdr_offset += copylen; - return -EAGAIN; +static inline void +iscsi_chunk_init_linear(struct iscsi_chunk *chunk, void *data, size_t size, + iscsi_chunk_done_fn_t *done, struct hash_desc *hash) +{ + __iscsi_chunk_init(chunk, size, done, hash); + chunk->data = data; + chunk->size = size; +} + +static inline int +iscsi_chunk_seek_sg(struct iscsi_chunk *chunk, + struct scatterlist *sg, unsigned int sg_count, + unsigned int offset, size_t size, + iscsi_chunk_done_fn_t *done, struct hash_desc *hash) +{ + unsigned int i; + + __iscsi_chunk_init(chunk, size, done, hash); + for (i = 0; i < sg_count; ++i) { + if (offset < sg[i].length) { + chunk->sg = sg; + chunk->sg_count = sg_count; + iscsi_tcp_chunk_init_sg(chunk, i, offset); + return 0; } - tcp_conn->in.hdr = &tcp_conn->hdr; - tcp_conn->discontiguous_hdr_cnt++; - tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER; + offset -= sg[i].length; } + return ISCSI_ERR_DATA_OFFSET; +} + +/** + * iscsi_tcp_hdr_recv_prep - prep chunk for hdr reception + * @tcp_conn: iscsi connection to prep for + * + * This function always passes NULL for the hash argument, because when this + * function is called we do not yet know the final size of the header and want + * to delay the digest processing until we know that. + */ +static void +iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn) +{ + debug_tcp("iscsi_tcp_hdr_recv_prep(%p%s)\n", tcp_conn, + tcp_conn->iscsi_conn->hdrdgst_en ? ", digest enabled" : ""); + iscsi_chunk_init_linear(&tcp_conn->in.chunk, + tcp_conn->in.hdr_buf, sizeof(struct iscsi_hdr), + iscsi_tcp_hdr_recv_done, NULL); +} + +/* + * Handle incoming reply to any other type of command + */ +static int +iscsi_tcp_data_recv_done(struct iscsi_tcp_conn *tcp_conn, + struct iscsi_chunk *chunk) +{ + struct iscsi_conn *conn = tcp_conn->iscsi_conn; + int rc = 0; + + if (!iscsi_tcp_dgst_verify(tcp_conn, chunk)) + return ISCSI_ERR_DATA_DGST; + + rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, + conn->data, tcp_conn->in.datalen); + if (rc) + return rc; + + iscsi_tcp_hdr_recv_prep(tcp_conn); return 0; } +static void +iscsi_tcp_data_recv_prep(struct iscsi_tcp_conn *tcp_conn) +{ + struct iscsi_conn *conn = tcp_conn->iscsi_conn; + struct hash_desc *rx_hash = NULL; + + if (conn->datadgst_en) + rx_hash = &tcp_conn->rx_hash; + + iscsi_chunk_init_linear(&tcp_conn->in.chunk, + conn->data, tcp_conn->in.datalen, + iscsi_tcp_data_recv_done, rx_hash); +} + /* * must be called with session lock */ @@ -417,16 +682,49 @@ iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask) return 0; } +/* + * Handle incoming reply to DataIn command + */ static int -iscsi_tcp_hdr_recv(struct iscsi_conn *conn) +iscsi_tcp_process_data_in(struct iscsi_tcp_conn *tcp_conn, + struct iscsi_chunk *chunk) +{ + struct iscsi_conn *conn = tcp_conn->iscsi_conn; + struct iscsi_hdr *hdr = tcp_conn->in.hdr; + int rc; + + if (!iscsi_tcp_dgst_verify(tcp_conn, chunk)) + return ISCSI_ERR_DATA_DGST; + + /* check for non-exceptional status */ + if (hdr->flags & ISCSI_FLAG_DATA_STATUS) { + rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0); + if (rc) + return rc; + } + + iscsi_tcp_hdr_recv_prep(tcp_conn); + return 0; +} + +/** + * iscsi_tcp_hdr_dissect - process PDU header + * @conn: iSCSI connection + * @hdr: PDU header + * + * This function analyzes the header of the PDU received, + * and performs several sanity checks. If the PDU is accompanied + * by data, the receive buffer is set up to copy the incoming data + * to the correct location. + */ +static int +iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr) { int rc = 0, opcode, ahslen; - struct iscsi_hdr *hdr; struct iscsi_session *session = conn->session; struct iscsi_tcp_conn *tcp_conn = conn->dd_data; - uint32_t cdgst, rdgst = 0, itt; - - hdr = tcp_conn->in.hdr; + struct iscsi_cmd_task *ctask; + uint32_t itt; /* verify PDU length */ tcp_conn->in.datalen = ntoh24(hdr->dlength); @@ -435,77 +733,72 @@ iscsi_tcp_hdr_recv(struct iscsi_conn *conn) tcp_conn->in.datalen, conn->max_recv_dlength); return ISCSI_ERR_DATALEN; } - tcp_conn->data_copied = 0; - /* read AHS */ + /* Additional header segments. So far, we don't + * process additional headers. + */ ahslen = hdr->hlength << 2; - tcp_conn->in.offset += ahslen; - tcp_conn->in.copy -= ahslen; - if (tcp_conn->in.copy < 0) { - printk(KERN_ERR "iscsi_tcp: can't handle AHS with length " - "%d bytes\n", ahslen); - return ISCSI_ERR_AHSLEN; - } - - /* calculate read padding */ - tcp_conn->in.padding = tcp_conn->in.datalen & (ISCSI_PAD_LEN-1); - if (tcp_conn->in.padding) { - tcp_conn->in.padding = ISCSI_PAD_LEN - tcp_conn->in.padding; - debug_scsi("read padding %d bytes\n", tcp_conn->in.padding); - } - - if (conn->hdrdgst_en) { - struct scatterlist sg; - - sg_init_one(&sg, (u8 *)hdr, - sizeof(struct iscsi_hdr) + ahslen); - crypto_hash_digest(&tcp_conn->rx_hash, &sg, sg.length, - (u8 *)&cdgst); - rdgst = *(uint32_t*)((char*)hdr + sizeof(struct iscsi_hdr) + - ahslen); - if (cdgst != rdgst) { - printk(KERN_ERR "iscsi_tcp: hdrdgst error " - "recv 0x%x calc 0x%x\n", rdgst, cdgst); - return ISCSI_ERR_HDR_DGST; - } - } opcode = hdr->opcode & ISCSI_OPCODE_MASK; /* verify itt (itt encoding: age+cid+itt) */ rc = iscsi_verify_itt(conn, hdr, &itt); if (rc == ISCSI_ERR_NO_SCSI_CMD) { + /* XXX: what does this do? */ tcp_conn->in.datalen = 0; /* force drop */ return 0; } else if (rc) return rc; - debug_tcp("opcode 0x%x offset %d copy %d ahslen %d datalen %d\n", - opcode, tcp_conn->in.offset, tcp_conn->in.copy, - ahslen, tcp_conn->in.datalen); + debug_tcp("opcode 0x%x ahslen %d datalen %d\n", + opcode, ahslen, tcp_conn->in.datalen); switch(opcode) { case ISCSI_OP_SCSI_DATA_IN: - tcp_conn->in.ctask = session->cmds[itt]; - rc = iscsi_data_rsp(conn, tcp_conn->in.ctask); + ctask = session->cmds[itt]; + rc = iscsi_data_rsp(conn, ctask); if (rc) return rc; + if (tcp_conn->in.datalen) { + struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data; + struct hash_desc *rx_hash = NULL; + + /* + * Setup copy of Data-In into the Scsi_Cmnd + * Scatterlist case: + * We set up the iscsi_chunk to point to the next + * scatterlist entry to copy to. As we go along, + * we move on to the next scatterlist entry and + * update the digest per-entry. + */ + if (conn->datadgst_en) + rx_hash = &tcp_conn->rx_hash; + + debug_tcp("iscsi_tcp_begin_data_in(%p, offset=%d, " + "datalen=%d)\n", tcp_conn, + tcp_ctask->data_offset, + tcp_conn->in.datalen); + return iscsi_chunk_seek_sg(&tcp_conn->in.chunk, + scsi_sglist(ctask->sc), + scsi_sg_count(ctask->sc), + tcp_ctask->data_offset, + tcp_conn->in.datalen, + iscsi_tcp_process_data_in, + rx_hash); + } /* fall through */ case ISCSI_OP_SCSI_CMD_RSP: - tcp_conn->in.ctask = session->cmds[itt]; - if (tcp_conn->in.datalen) - goto copy_hdr; - - spin_lock(&session->lock); - rc = __iscsi_complete_pdu(conn, hdr, NULL, 0); - spin_unlock(&session->lock); + if (tcp_conn->in.datalen) { + iscsi_tcp_data_recv_prep(tcp_conn); + return 0; + } + rc = iscsi_complete_pdu(conn, hdr, NULL, 0); break; case ISCSI_OP_R2T: - tcp_conn->in.ctask = session->cmds[itt]; + ctask = session->cmds[itt]; if (ahslen) rc = ISCSI_ERR_AHSLEN; - else if (tcp_conn->in.ctask->sc->sc_data_direction == - DMA_TO_DEVICE) - rc = iscsi_r2t_rsp(conn, tcp_conn->in.ctask); + else if (ctask->sc->sc_data_direction == DMA_TO_DEVICE) + rc = iscsi_r2t_rsp(conn, ctask); else rc = ISCSI_ERR_PROTO; break; @@ -518,8 +811,7 @@ iscsi_tcp_hdr_recv(struct iscsi_conn *conn) * than 8K, but there are no targets that currently do this. * For now we fail until we find a vendor that needs it */ - if (ISCSI_DEF_MAX_RECV_SEG_LEN < - tcp_conn->in.datalen) { + if (ISCSI_DEF_MAX_RECV_SEG_LEN < tcp_conn->in.datalen) { printk(KERN_ERR "iscsi_tcp: received buffer of len %u " "but conn buffer is only %u (opcode %0x)\n", tcp_conn->in.datalen, @@ -528,8 +820,13 @@ iscsi_tcp_hdr_recv(struct iscsi_conn *conn) break; } - if (tcp_conn->in.datalen) - goto copy_hdr; + /* If there's data coming in with the response, + * receive it to the connection's buffer. + */ + if (tcp_conn->in.datalen) { + iscsi_tcp_data_recv_prep(tcp_conn); + return 0; + } /* fall through */ case ISCSI_OP_LOGOUT_RSP: case ISCSI_OP_NOOP_IN: @@ -541,129 +838,15 @@ iscsi_tcp_hdr_recv(struct iscsi_conn *conn) break; } - return rc; - -copy_hdr: - /* - * if we did zero copy for the header but we will need multiple - * skbs to complete the command then we have to copy the header - * for later use - */ - if (tcp_conn->in.zero_copy_hdr && tcp_conn->in.copy <= - (tcp_conn->in.datalen + tcp_conn->in.padding + - (conn->datadgst_en ? 4 : 0))) { - debug_tcp("Copying header for later use. in.copy %d in.datalen" - " %d\n", tcp_conn->in.copy, tcp_conn->in.datalen); - memcpy(&tcp_conn->hdr, tcp_conn->in.hdr, - sizeof(struct iscsi_hdr)); - tcp_conn->in.hdr = &tcp_conn->hdr; - tcp_conn->in.zero_copy_hdr = 0; - } - return 0; -} - -/** - * iscsi_ctask_copy - copy skb bits to the destanation cmd task - * @conn: iscsi tcp connection - * @ctask: scsi command task - * @buf: buffer to copy to - * @buf_size: size of buffer - * @offset: offset within the buffer - * - * Notes: - * The function calls skb_copy_bits() and updates per-connection and - * per-cmd byte counters. - * - * Read counters (in bytes): - * - * conn->in.offset offset within in progress SKB - * conn->in.copy left to copy from in progress SKB - * including padding - * conn->in.copied copied already from in progress SKB - * conn->data_copied copied already from in progress buffer - * ctask->sent total bytes sent up to the MidLayer - * ctask->data_count left to copy from in progress Data-In - * buf_left left to copy from in progress buffer - **/ -static inline int -iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask, - void *buf, int buf_size, int offset) -{ - struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data; - int buf_left = buf_size - (tcp_conn->data_copied + offset); - unsigned size = min(tcp_conn->in.copy, buf_left); - int rc; - - size = min(size, ctask->data_count); - - debug_tcp("ctask_copy %d bytes at offset %d copied %d\n", - size, tcp_conn->in.offset, tcp_conn->in.copied); - - BUG_ON(size <= 0); - BUG_ON(tcp_ctask->sent + size > scsi_bufflen(ctask->sc)); - - rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset, - (char*)buf + (offset + tcp_conn->data_copied), size); - /* must fit into skb->len */ - BUG_ON(rc); - - tcp_conn->in.offset += size; - tcp_conn->in.copy -= size; - tcp_conn->in.copied += size; - tcp_conn->data_copied += size; - tcp_ctask->sent += size; - ctask->data_count -= size; - - BUG_ON(tcp_conn->in.copy < 0); - BUG_ON(ctask->data_count < 0); - - if (buf_size != (tcp_conn->data_copied + offset)) { - if (!ctask->data_count) { - BUG_ON(buf_size - tcp_conn->data_copied < 0); - /* done with this PDU */ - return buf_size - tcp_conn->data_copied; - } - return -EAGAIN; + if (rc == 0) { + /* Anything that comes with data should have + * been handled above. */ + if (tcp_conn->in.datalen) + return ISCSI_ERR_PROTO; + iscsi_tcp_hdr_recv_prep(tcp_conn); } - /* done with this buffer or with both - PDU and buffer */ - tcp_conn->data_copied = 0; - return 0; -} - -/** - * iscsi_tcp_copy - copy skb bits to the destanation buffer - * @conn: iscsi tcp connection - * - * Notes: - * The function calls skb_copy_bits() and updates per-connection - * byte counters. - **/ -static inline int -iscsi_tcp_copy(struct iscsi_conn *conn, int buf_size) -{ - struct iscsi_tcp_conn *tcp_conn = conn->dd_data; - int buf_left = buf_size - tcp_conn->data_copied; - int size = min(tcp_conn->in.copy, buf_left); - int rc; - - debug_tcp("tcp_copy %d bytes at offset %d copied %d\n", - size, tcp_conn->in.offset, tcp_conn->data_copied); - BUG_ON(size <= 0); - - rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset, - (char*)conn->data + tcp_conn->data_copied, size); - BUG_ON(rc); - - tcp_conn->in.offset += size; - tcp_conn->in.copy -= size; - tcp_conn->in.copied += size; - tcp_conn->data_copied += size; - - if (buf_size != tcp_conn->data_copied) - return -EAGAIN; - - return 0; + return rc; } static inline void @@ -677,325 +860,146 @@ partial_sg_digest_update(struct hash_desc *desc, struct scatterlist *sg, crypto_hash_update(desc, &temp, length); } -static void -iscsi_recv_digest_update(struct iscsi_tcp_conn *tcp_conn, char* buf, int len) -{ - struct scatterlist tmp; - - sg_init_one(&tmp, buf, len); - crypto_hash_update(&tcp_conn->rx_hash, &tmp, len); -} - -static int iscsi_scsi_data_in(struct iscsi_conn *conn) +/** + * iscsi_tcp_hdr_recv_done - process PDU header + * + * This is the callback invoked when the PDU header has + * been received. If the header is followed by additional + * header segments, we go back for more data. + */ +static int +iscsi_tcp_hdr_recv_done(struct iscsi_tcp_conn *tcp_conn, + struct iscsi_chunk *chunk) { - struct iscsi_tcp_conn *tcp_conn = conn->dd_data; - struct iscsi_cmd_task *ctask = tcp_conn->in.ctask; - struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data; - struct scsi_cmnd *sc = ctask->sc; - struct scatterlist *sg; - int i, offset, rc = 0; - - BUG_ON((void*)ctask != sc->SCp.ptr); - - offset = tcp_ctask->data_offset; - sg = scsi_sglist(sc); - - if (tcp_ctask->data_offset) - for (i = 0; i < tcp_ctask->sg_count; i++) - offset -= sg[i].length; - /* we've passed through partial sg*/ - if (offset < 0) - offset = 0; - - for (i = tcp_ctask->sg_count; i < scsi_sg_count(sc); i++) { - char *dest; - - dest = kmap_atomic(sg_page(&sg[i]), KM_SOFTIRQ0); - rc = iscsi_ctask_copy(tcp_conn, ctask, dest + sg[i].offset, - sg[i].length, offset); - kunmap_atomic(dest, KM_SOFTIRQ0); - if (rc == -EAGAIN) - /* continue with the next SKB/PDU */ - return rc; - if (!rc) { - if (conn->datadgst_en) { - if (!offset) - crypto_hash_update( - &tcp_conn->rx_hash, - &sg[i], sg[i].length); - else - partial_sg_digest_update( - &tcp_conn->rx_hash, - &sg[i], - sg[i].offset + offset, - sg[i].length - offset); - } - offset = 0; - tcp_ctask->sg_count++; - } - - if (!ctask->data_count) { - if (rc && conn->datadgst_en) - /* - * data-in is complete, but buffer not... - */ - partial_sg_digest_update(&tcp_conn->rx_hash, - &sg[i], - sg[i].offset, - sg[i].length-rc); - rc = 0; - break; - } - - if (!tcp_conn->in.copy) - return -EAGAIN; - } - BUG_ON(ctask->data_count); + struct iscsi_conn *conn = tcp_conn->iscsi_conn; + struct iscsi_hdr *hdr; - /* check for non-exceptional status */ - if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) { - debug_scsi("done [sc %lx res %d itt 0x%x flags 0x%x]\n", - (long)sc, sc->result, ctask->itt, - tcp_conn->in.hdr->flags); - spin_lock(&conn->session->lock); - __iscsi_complete_pdu(conn, tcp_conn->in.hdr, NULL, 0); - spin_unlock(&conn->session->lock); + /* Check if there are additional header segments + * *prior* to computing the digest, because we + * may need to go back to the caller for more. + */ + hdr = (struct iscsi_hdr *) tcp_conn->in.hdr_buf; + if (chunk->copied == sizeof(struct iscsi_hdr) && hdr->hlength) { + /* Bump the header length - the caller will + * just loop around and get the AHS for us, and + * call again. */ + unsigned int ahslen = hdr->hlength << 2; + + /* Make sure we don't overflow */ + if (sizeof(*hdr) + ahslen > sizeof(tcp_conn->in.hdr_buf)) + return ISCSI_ERR_AHSLEN; + + chunk->total_size += ahslen; + chunk->size += ahslen; + return 0; } - return rc; -} - -static int -iscsi_data_recv(struct iscsi_conn *conn) -{ - struct iscsi_tcp_conn *tcp_conn = conn->dd_data; - int rc = 0, opcode; - - opcode = tcp_conn->in.hdr->opcode & ISCSI_OPCODE_MASK; - switch (opcode) { - case ISCSI_OP_SCSI_DATA_IN: - rc = iscsi_scsi_data_in(conn); - break; - case ISCSI_OP_SCSI_CMD_RSP: - case ISCSI_OP_TEXT_RSP: - case ISCSI_OP_LOGIN_RSP: - case ISCSI_OP_ASYNC_EVENT: - case ISCSI_OP_REJECT: - /* - * Collect data segment to the connection's data - * placeholder - */ - if (iscsi_tcp_copy(conn, tcp_conn->in.datalen)) { - rc = -EAGAIN; - goto exit; + /* We're done processing the header. See if we're doing + * header digests; if so, set up the recv_digest buffer + * and go back for more. */ + if (conn->hdrdgst_en) { + if (chunk->digest_len == 0) { + iscsi_tcp_chunk_splice_digest(chunk, + chunk->recv_digest); + return 0; } + iscsi_tcp_dgst_header(&tcp_conn->rx_hash, hdr, + chunk->total_copied - ISCSI_DIGEST_SIZE, + chunk->digest); - rc = iscsi_complete_pdu(conn, tcp_conn->in.hdr, conn->data, - tcp_conn->in.datalen); - if (!rc && conn->datadgst_en && opcode != ISCSI_OP_LOGIN_RSP) - iscsi_recv_digest_update(tcp_conn, conn->data, - tcp_conn->in.datalen); - break; - default: - BUG_ON(1); + if (!iscsi_tcp_dgst_verify(tcp_conn, chunk)) + return ISCSI_ERR_HDR_DGST; } -exit: - return rc; + + tcp_conn->in.hdr = hdr; + return iscsi_tcp_hdr_dissect(conn, hdr); } /** - * iscsi_tcp_data_recv - TCP receive in sendfile fashion + * iscsi_tcp_recv - TCP receive in sendfile fashion * @rd_desc: read descriptor * @skb: socket buffer * @offset: offset in skb * @len: skb->len - offset **/ static int -iscsi_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, - unsigned int offset, size_t len) +iscsi_tcp_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, + unsigned int offset, size_t len) { - int rc; struct iscsi_conn *conn = rd_desc->arg.data; struct iscsi_tcp_conn *tcp_conn = conn->dd_data; - int processed; - char pad[ISCSI_PAD_LEN]; - struct scatterlist sg; - - /* - * Save current SKB and its offset in the corresponding - * connection context. - */ - tcp_conn->in.copy = skb->len - offset; - tcp_conn->in.offset = offset; - tcp_conn->in.skb = skb; - tcp_conn->in.len = tcp_conn->in.copy; - BUG_ON(tcp_conn->in.copy <= 0); - debug_tcp("in %d bytes\n", tcp_conn->in.copy); + struct iscsi_chunk *chunk = &tcp_conn->in.chunk; + struct skb_seq_state seq; + unsigned int consumed = 0; + int rc = 0; -more: - tcp_conn->in.copied = 0; - rc = 0; + debug_tcp("in %d bytes\n", skb->len - offset); if (unlikely(conn->suspend_rx)) { debug_tcp("conn %d Rx suspended!\n", conn->id); return 0; } - if (tcp_conn->in_progress == IN_PROGRESS_WAIT_HEADER || - tcp_conn->in_progress == IN_PROGRESS_HEADER_GATHER) { - rc = iscsi_hdr_extract(tcp_conn); - if (rc) { - if (rc == -EAGAIN) - goto nomore; - else { - iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); - return 0; - } - } - - /* - * Verify and process incoming PDU header. - */ - rc = iscsi_tcp_hdr_recv(conn); - if (!rc && tcp_conn->in.datalen) { - if (conn->datadgst_en) - crypto_hash_init(&tcp_conn->rx_hash); - tcp_conn->in_progress = IN_PROGRESS_DATA_RECV; - } else if (rc) { - iscsi_conn_failure(conn, rc); - return 0; - } - } - - if (tcp_conn->in_progress == IN_PROGRESS_DDIGEST_RECV && - tcp_conn->in.copy) { - uint32_t recv_digest; + skb_prepare_seq_read(skb, offset, skb->len, &seq); + while (1) { + unsigned int avail; + const u8 *ptr; - debug_tcp("extra data_recv offset %d copy %d\n", - tcp_conn->in.offset, tcp_conn->in.copy); - - if (!tcp_conn->data_copied) { - if (tcp_conn->in.padding) { - debug_tcp("padding -> %d\n", - tcp_conn->in.padding); - memset(pad, 0, tcp_conn->in.padding); - sg_init_one(&sg, pad, tcp_conn->in.padding); - crypto_hash_update(&tcp_conn->rx_hash, - &sg, sg.length); + avail = skb_seq_read(consumed, &ptr, &seq); + if (avail == 0) + break; + BUG_ON(chunk->copied >= chunk->size); + + debug_tcp("skb %p ptr=%p avail=%u\n", skb, ptr, avail); + rc = iscsi_tcp_chunk_recv(tcp_conn, chunk, ptr, avail); + BUG_ON(rc == 0); + consumed += rc; + + if (chunk->total_copied >= chunk->total_size) { + rc = chunk->done(tcp_conn, chunk); + if (rc != 0) { + skb_abort_seq_read(&seq); + goto error; } - crypto_hash_final(&tcp_conn->rx_hash, - (u8 *) &tcp_conn->in.datadgst); - debug_tcp("rx digest 0x%x\n", tcp_conn->in.datadgst); - } - - rc = iscsi_tcp_copy(conn, sizeof(uint32_t)); - if (rc) { - if (rc == -EAGAIN) - goto again; - iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); - return 0; - } - - memcpy(&recv_digest, conn->data, sizeof(uint32_t)); - if (recv_digest != tcp_conn->in.datadgst) { - debug_tcp("iscsi_tcp: data digest error!" - "0x%x != 0x%x\n", recv_digest, - tcp_conn->in.datadgst); - iscsi_conn_failure(conn, ISCSI_ERR_DATA_DGST); - return 0; - } else { - debug_tcp("iscsi_tcp: data digest match!" - "0x%x == 0x%x\n", recv_digest, - tcp_conn->in.datadgst); - tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER; - } - } - - if (tcp_conn->in_progress == IN_PROGRESS_DATA_RECV && - tcp_conn->in.copy) { - debug_tcp("data_recv offset %d copy %d\n", - tcp_conn->in.offset, tcp_conn->in.copy); - rc = iscsi_data_recv(conn); - if (rc) { - if (rc == -EAGAIN) - goto again; - iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); - return 0; + /* The done() functions sets up the + * next chunk. */ } - - if (tcp_conn->in.padding) - tcp_conn->in_progress = IN_PROGRESS_PAD_RECV; - else if (conn->datadgst_en) - tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV; - else - tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER; - tcp_conn->data_copied = 0; - } - - if (tcp_conn->in_progress == IN_PROGRESS_PAD_RECV && - tcp_conn->in.copy) { - int copylen = min(tcp_conn->in.padding - tcp_conn->data_copied, - tcp_conn->in.copy); - - tcp_conn->in.copy -= copylen; - tcp_conn->in.offset += copylen; - tcp_conn->data_copied += copylen; - - if (tcp_conn->data_copied != tcp_conn->in.padding) - tcp_conn->in_progress = IN_PROGRESS_PAD_RECV; - else if (conn->datadgst_en) - tcp_conn->in_progress = IN_PROGRESS_DDIGEST_RECV; - else - tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER; - tcp_conn->data_copied = 0; } - debug_tcp("f, processed %d from out of %d padding %d\n", - tcp_conn->in.offset - offset, (int)len, tcp_conn->in.padding); - BUG_ON(tcp_conn->in.offset - offset > len); + conn->rxdata_octets += consumed; + return consumed; - if (tcp_conn->in.offset - offset != len) { - debug_tcp("continue to process %d bytes\n", - (int)len - (tcp_conn->in.offset - offset)); - goto more; - } - -nomore: - processed = tcp_conn->in.offset - offset; - BUG_ON(processed == 0); - return processed; - -again: - processed = tcp_conn->in.offset - offset; - debug_tcp("c, processed %d from out of %d rd_desc_cnt %d\n", - processed, (int)len, (int)rd_desc->count); - BUG_ON(processed == 0); - BUG_ON(processed > len); - - conn->rxdata_octets += processed; - return processed; +error: + debug_tcp("Error receiving PDU, errno=%d\n", rc); + iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED); + return 0; } static void iscsi_tcp_data_ready(struct sock *sk, int flag) { struct iscsi_conn *conn = sk->sk_user_data; + struct iscsi_tcp_conn *tcp_conn = conn->dd_data; read_descriptor_t rd_desc; read_lock(&sk->sk_callback_lock); /* - * Use rd_desc to pass 'conn' to iscsi_tcp_data_recv. + * Use rd_desc to pass 'conn' to iscsi_tcp_recv. * We set count to 1 because we want the network layer to - * hand us all the skbs that are available. iscsi_tcp_data_recv + * hand us all the skbs that are available. iscsi_tcp_recv * handled pdus that cross buffers or pdus that still need data. */ rd_desc.arg.data = conn; rd_desc.count = 1; - tcp_read_sock(sk, &rd_desc, iscsi_tcp_data_recv); + tcp_read_sock(sk, &rd_desc, iscsi_tcp_recv); read_unlock(&sk->sk_callback_lock); + + /* If we had to (atomically) map a highmem page, + * unmap it now. */ + iscsi_tcp_chunk_unmap(&tcp_conn->in.chunk); } static void @@ -1097,9 +1101,9 @@ iscsi_send(struct iscsi_conn *conn, struct iscsi_buf *buf, int size, int flags) * slab case. */ if (buf->use_sendmsg) - res = sock_no_sendpage(sk, sg_page(&buf->sg), offset, size, flags); + res = sock_no_sendpage(sk, buf->sg.page, offset, size, flags); else - res = tcp_conn->sendpage(sk, sg_page(&buf->sg), offset, size, flags); + res = tcp_conn->sendpage(sk, buf->sg.page, offset, size, flags); if (res >= 0) { conn->txdata_octets += res; @@ -1783,9 +1787,6 @@ iscsi_tcp_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx) conn->dd_data = tcp_conn; tcp_conn->iscsi_conn = conn; - tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER; - /* initial operational parameters */ - tcp_conn->hdr_size = sizeof(struct iscsi_hdr); tcp_conn->tx_hash.tfm = crypto_alloc_hash("crc32c", 0, CRYPTO_ALG_ASYNC); @@ -1862,11 +1863,9 @@ static void iscsi_tcp_conn_stop(struct iscsi_cls_conn *cls_conn, int flag) { struct iscsi_conn *conn = cls_conn->dd_data; - struct iscsi_tcp_conn *tcp_conn = conn->dd_data; iscsi_conn_stop(cls_conn, flag); iscsi_tcp_release_conn(conn); - tcp_conn->hdr_size = sizeof(struct iscsi_hdr); } static int iscsi_tcp_get_addr(struct iscsi_conn *conn, struct socket *sock, @@ -1966,7 +1965,7 @@ iscsi_tcp_conn_bind(struct iscsi_cls_session *cls_session, /* * set receive state machine into initial state */ - tcp_conn->in_progress = IN_PROGRESS_WAIT_HEADER; + iscsi_tcp_hdr_recv_prep(tcp_conn); return 0; free_socket: @@ -2059,9 +2058,6 @@ iscsi_conn_set_param(struct iscsi_cls_conn *cls_conn, enum iscsi_param param, switch(param) { case ISCSI_PARAM_HDRDGST_EN: iscsi_set_param(cls_conn, param, buf, buflen); - tcp_conn->hdr_size = sizeof(struct iscsi_hdr); - if (conn->hdrdgst_en) - tcp_conn->hdr_size += sizeof(__u32); break; case ISCSI_PARAM_DATADGST_EN: iscsi_set_param(cls_conn, param, buf, buflen); diff --git a/drivers/scsi/iscsi_tcp.h b/drivers/scsi/iscsi_tcp.h index 7eba44df0a7..f1c54115110 100644 --- a/drivers/scsi/iscsi_tcp.h +++ b/drivers/scsi/iscsi_tcp.h @@ -24,13 +24,6 @@ #include <scsi/libiscsi.h> -/* Socket's Receive state machine */ -#define IN_PROGRESS_WAIT_HEADER 0x0 -#define IN_PROGRESS_HEADER_GATHER 0x1 -#define IN_PROGRESS_DATA_RECV 0x2 -#define IN_PROGRESS_DDIGEST_RECV 0x3 -#define IN_PROGRESS_PAD_RECV 0x4 - /* xmit state machine */ #define XMSTATE_IDLE 0x0 #define XMSTATE_CMD_HDR_INIT 0x1 @@ -54,41 +47,64 @@ struct crypto_hash; struct socket; +struct iscsi_tcp_conn; +struct iscsi_chunk; + +typedef int iscsi_chunk_done_fn_t(struct iscsi_tcp_conn *, + struct iscsi_chunk *); + +struct iscsi_chunk { + unsigned char *data; + unsigned int size; + unsigned int copied; + unsigned int total_size; + unsigned int total_copied; + + struct hash_desc *hash; + unsigned char recv_digest[ISCSI_DIGEST_SIZE]; + unsigned char digest[ISCSI_DIGEST_SIZE]; + unsigned int digest_len; + + struct scatterlist *sg; + void *sg_mapped; + unsigned int sg_offset; + unsigned int sg_index; + unsigned int sg_count; + + iscsi_chunk_done_fn_t *done; +}; /* Socket connection recieve helper */ struct iscsi_tcp_recv { struct iscsi_hdr *hdr; - struct sk_buff *skb; - int offset; - int len; - int hdr_offset; - int copy; - int copied; - int padding; - struct iscsi_cmd_task *ctask; /* current cmd in progress */ + struct iscsi_chunk chunk; + + /* Allocate buffer for BHS + AHS */ + uint32_t hdr_buf[64]; /* copied and flipped values */ int datalen; - int datadgst; - char zero_copy_hdr; +}; + +/* Socket connection send helper */ +struct iscsi_tcp_send { + struct iscsi_hdr *hdr; + struct iscsi_chunk chunk; + struct iscsi_chunk data_chunk; + + /* Allocate buffer for BHS + AHS */ + uint32_t hdr_buf[64]; }; struct iscsi_tcp_conn { struct iscsi_conn *iscsi_conn; struct socket *sock; - struct iscsi_hdr hdr; /* header placeholder */ - char hdrext[4*sizeof(__u16) + - sizeof(__u32)]; - int data_copied; int stop_stage; /* conn_stop() flag: * * stop to recover, * * stop to terminate */ - /* iSCSI connection-wide sequencing */ - int hdr_size; /* PDU header size */ - /* control data */ struct iscsi_tcp_recv in; /* TCP receive context */ - int in_progress; /* connection state machine */ + struct iscsi_tcp_send out; /* TCP send context */ /* old values for socket callbacks */ void (*old_data_ready)(struct sock *, int); |