diff options
Diffstat (limited to 'sys/dev/iscsi/icl.c')
| -rw-r--r-- | sys/dev/iscsi/icl.c | 1292 |
1 files changed, 1292 insertions, 0 deletions
diff --git a/sys/dev/iscsi/icl.c b/sys/dev/iscsi/icl.c new file mode 100644 index 0000000..eb9cf4e --- /dev/null +++ b/sys/dev/iscsi/icl.c @@ -0,0 +1,1292 @@ +/*- + * Copyright (c) 2012 The FreeBSD Foundation + * All rights reserved. + * + * This software was developed by Edward Tomasz Napierala under sponsorship + * from the FreeBSD Foundation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +/* + * iSCSI Common Layer. It's used by both the initiator and target to send + * and receive iSCSI PDUs. + */ + +#include <sys/param.h> +#include <sys/capability.h> +#include <sys/condvar.h> +#include <sys/conf.h> +#include <sys/file.h> +#include <sys/kernel.h> +#include <sys/kthread.h> +#include <sys/lock.h> +#include <sys/mbuf.h> +#include <sys/mutex.h> +#include <sys/module.h> +#include <sys/socket.h> +#include <sys/socketvar.h> +#include <sys/sysctl.h> +#include <sys/systm.h> +#include <sys/sx.h> +#include <sys/uio.h> +#include <vm/uma.h> +#include <netinet/in.h> +#include <netinet/tcp.h> + +#include "icl.h" +#include "iscsi_proto.h" + +SYSCTL_NODE(_kern, OID_AUTO, icl, CTLFLAG_RD, 0, "iSCSI Common Layer"); +static int debug = 1; +TUNABLE_INT("kern.icl.debug", &debug); +SYSCTL_INT(_kern_icl, OID_AUTO, debug, CTLFLAG_RW, + &debug, 1, "Enable debug messages"); +static int partial_receive_len = 1 * 1024; /* XXX: More? */ +TUNABLE_INT("kern.icl.partial_receive_len", &partial_receive_len); +SYSCTL_INT(_kern_icl, OID_AUTO, partial_receive_len, CTLFLAG_RW, + &partial_receive_len, 1 * 1024, "Minimum read size for partially received " + "data segment"); + +static uma_zone_t icl_conn_zone; +static uma_zone_t icl_pdu_zone; + +static volatile u_int icl_ncons; + +#define ICL_DEBUG(X, ...) \ + if (debug > 1) { \ + printf("%s: " X "\n", __func__, ## __VA_ARGS__);\ + } while (0) + +#define ICL_WARN(X, ...) \ + if (debug > 0) { \ + printf("WARNING: %s: " X "\n", \ + __func__, ## __VA_ARGS__); \ + } while (0) + +#define ICL_CONN_LOCK(X) mtx_lock(&X->ic_lock) +#define ICL_CONN_UNLOCK(X) mtx_unlock(&X->ic_lock) +#define ICL_CONN_LOCK_ASSERT(X) mtx_assert(&X->ic_lock, MA_OWNED) + +static void +icl_conn_fail(struct icl_conn *ic) +{ + if (ic->ic_socket == NULL) + return; + + /* + * XXX + */ + ic->ic_socket->so_error = EDOOFUS; + (ic->ic_error)(ic); +} + +static struct mbuf * +icl_conn_receive(struct icl_conn *ic, size_t len) +{ + struct uio uio; + struct socket *so; + struct mbuf *m; + int error, flags; + + so = ic->ic_socket; + + memset(&uio, 0, sizeof(uio)); + uio.uio_resid = len; + + flags = MSG_DONTWAIT; + error = soreceive(so, NULL, &uio, &m, NULL, &flags); + if (error != 0) { + ICL_DEBUG("soreceive error %d", error); + return (NULL); + } + if (uio.uio_resid != 0) { + m_freem(m); + ICL_DEBUG("short read"); + return (NULL); + } + + return (m); +} + +static struct icl_pdu * +icl_pdu_new(struct icl_conn *ic, int flags) +{ + struct icl_pdu *ip; + + refcount_acquire(&ic->ic_outstanding_pdus); + ip = uma_zalloc(icl_pdu_zone, flags | M_ZERO); + if (ip == NULL) { + ICL_WARN("failed to allocate %zd bytes", sizeof(*ip)); + refcount_release(&ic->ic_outstanding_pdus); + return (NULL); + } + + ip->ip_conn = ic; + + return (ip); +} + +void +icl_pdu_free(struct icl_pdu *ip) +{ + struct icl_conn *ic; + + ic = ip->ip_conn; + + m_freem(ip->ip_bhs_mbuf); + m_freem(ip->ip_ahs_mbuf); + m_freem(ip->ip_data_mbuf); + uma_zfree(icl_pdu_zone, ip); + refcount_release(&ic->ic_outstanding_pdus); +} + +/* + * Allocate icl_pdu with empty BHS to fill up by the caller. + */ +struct icl_pdu * +icl_pdu_new_bhs(struct icl_conn *ic, int flags) +{ + struct icl_pdu *ip; + + ip = icl_pdu_new(ic, flags); + if (ip == NULL) + return (NULL); + + ip->ip_bhs_mbuf = m_getm2(NULL, sizeof(struct iscsi_bhs), + flags, MT_DATA, M_PKTHDR); + if (ip->ip_bhs_mbuf == NULL) { + ICL_WARN("failed to allocate %zd bytes", sizeof(*ip)); + icl_pdu_free(ip); + return (NULL); + } + ip->ip_bhs = mtod(ip->ip_bhs_mbuf, struct iscsi_bhs *); + memset(ip->ip_bhs, 0, sizeof(struct iscsi_bhs)); + ip->ip_bhs_mbuf->m_len = sizeof(struct iscsi_bhs); + + return (ip); +} + +static int +icl_pdu_ahs_length(const struct icl_pdu *request) +{ + + return (request->ip_bhs->bhs_total_ahs_len * 4); +} + +size_t +icl_pdu_data_segment_length(const struct icl_pdu *request) +{ + uint32_t len = 0; + + len += request->ip_bhs->bhs_data_segment_len[0]; + len <<= 8; + len += request->ip_bhs->bhs_data_segment_len[1]; + len <<= 8; + len += request->ip_bhs->bhs_data_segment_len[2]; + + return (len); +} + +static void +icl_pdu_set_data_segment_length(struct icl_pdu *response, uint32_t len) +{ + + response->ip_bhs->bhs_data_segment_len[2] = len; + response->ip_bhs->bhs_data_segment_len[1] = len >> 8; + response->ip_bhs->bhs_data_segment_len[0] = len >> 16; +} + +static size_t +icl_pdu_padding(const struct icl_pdu *ip) +{ + + if ((ip->ip_data_len % 4) != 0) + return (4 - (ip->ip_data_len % 4)); + + return (0); +} + +static size_t +icl_pdu_size(const struct icl_pdu *response) +{ + size_t len; + + KASSERT(response->ip_ahs_len == 0, ("responding with AHS")); + + len = sizeof(struct iscsi_bhs) + response->ip_data_len + + icl_pdu_padding(response); + if (response->ip_conn->ic_header_crc32c) + len += ISCSI_HEADER_DIGEST_SIZE; + if (response->ip_conn->ic_data_crc32c) + len += ISCSI_DATA_DIGEST_SIZE; + + return (len); +} + +static int +icl_pdu_receive_bhs(struct icl_pdu *request, size_t *availablep) +{ + struct mbuf *m; + + m = icl_conn_receive(request->ip_conn, sizeof(struct iscsi_bhs)); + if (m == NULL) { + ICL_DEBUG("failed to receive BHS"); + return (-1); + } + + request->ip_bhs_mbuf = m_pullup(m, sizeof(struct iscsi_bhs)); + if (request->ip_bhs_mbuf == NULL) { + ICL_WARN("m_pullup failed"); + return (-1); + } + request->ip_bhs = mtod(request->ip_bhs_mbuf, struct iscsi_bhs *); + + /* + * XXX: For architectures with strict alignment requirements + * we may need to allocate ip_bhs and copy the data into it. + * For some reason, though, not doing this doesn't seem + * to cause problems; tested on sparc64. + */ + + *availablep -= sizeof(struct iscsi_bhs); + return (0); +} + +static int +icl_pdu_receive_ahs(struct icl_pdu *request, size_t *availablep) +{ + + request->ip_ahs_len = icl_pdu_ahs_length(request); + if (request->ip_ahs_len == 0) + return (0); + + request->ip_ahs_mbuf = icl_conn_receive(request->ip_conn, + request->ip_ahs_len); + if (request->ip_ahs_mbuf == NULL) { + ICL_DEBUG("failed to receive AHS"); + return (-1); + } + + *availablep -= request->ip_ahs_len; + return (0); +} + +static uint32_t +icl_mbuf_to_crc32c(const struct mbuf *m0) +{ + uint32_t digest = 0xffffffff; + const struct mbuf *m; + + for (m = m0; m != NULL; m = m->m_next) + digest = calculate_crc32c(digest, + mtod(m, const void *), m->m_len); + + digest = digest ^ 0xffffffff; + + return (digest); +} + +static int +icl_pdu_check_header_digest(struct icl_pdu *request, size_t *availablep) +{ + struct mbuf *m; + uint32_t received_digest, valid_digest; + + if (request->ip_conn->ic_header_crc32c == false) + return (0); + + m = icl_conn_receive(request->ip_conn, ISCSI_HEADER_DIGEST_SIZE); + if (m == NULL) { + ICL_DEBUG("failed to receive header digest"); + return (-1); + } + + CTASSERT(sizeof(received_digest) == ISCSI_HEADER_DIGEST_SIZE); + memcpy(&received_digest, mtod(m, void *), ISCSI_HEADER_DIGEST_SIZE); + m_freem(m); + + *availablep -= ISCSI_HEADER_DIGEST_SIZE; + + /* + * XXX: Handle AHS. + */ + valid_digest = icl_mbuf_to_crc32c(request->ip_bhs_mbuf); + if (received_digest != valid_digest) { + ICL_WARN("header digest check failed; got 0x%x, " + "should be 0x%x", received_digest, valid_digest); + return (-1); + } + + return (0); +} + +/* + * Return the number of bytes that should be waiting in the receive socket + * before icl_pdu_receive_data_segment() gets called. + */ +static size_t +icl_pdu_data_segment_receive_len(const struct icl_pdu *request) +{ + size_t len; + + len = icl_pdu_data_segment_length(request); + if (len == 0) + return (0); + + /* + * Account for the parts of data segment already read from + * the socket buffer. + */ + KASSERT(len > request->ip_data_len, ("len <= request->ip_data_len")); + len -= request->ip_data_len; + + /* + * Don't always wait for the full data segment to be delivered + * to the socket; this might badly affect performance due to + * TCP window scaling. + */ + if (len > partial_receive_len) { +#if 0 + ICL_DEBUG("need %zd bytes of data, limiting to %zd", + len, partial_receive_len)); +#endif + len = partial_receive_len; + + return (len); + } + + /* + * Account for padding. Note that due to the way code is written, + * the icl_pdu_receive_data_segment() must always receive padding + * along with the last part of data segment, because it would be + * impossible to tell whether we've already received the full data + * segment including padding, or without it. + */ + if ((len % 4) != 0) + len += 4 - (len % 4); + +#if 0 + ICL_DEBUG("need %zd bytes of data", len)); +#endif + + return (len); +} + +static int +icl_pdu_receive_data_segment(struct icl_pdu *request, + size_t *availablep, bool *more_neededp) +{ + struct icl_conn *ic; + size_t len, padding = 0; + struct mbuf *m; + + ic = request->ip_conn; + + *more_neededp = false; + ic->ic_receive_len = 0; + + len = icl_pdu_data_segment_length(request); + if (len == 0) + return (0); + + if ((len % 4) != 0) + padding = 4 - (len % 4); + + /* + * Account for already received parts of data segment. + */ + KASSERT(len > request->ip_data_len, ("len <= request->ip_data_len")); + len -= request->ip_data_len; + + if (len + padding > *availablep) { + /* + * Not enough data in the socket buffer. Receive as much + * as we can. Don't receive padding, since, obviously, it's + * not the end of data segment yet. + */ +#if 0 + ICL_DEBUG("limited from %zd to %zd", + len + padding, *availablep - padding)); +#endif + len = *availablep - padding; + *more_neededp = true; + padding = 0; + } + + /* + * Must not try to receive padding without at least one byte + * of actual data segment. + */ + if (len > 0) { + m = icl_conn_receive(request->ip_conn, len + padding); + if (m == NULL) { + ICL_DEBUG("failed to receive data segment"); + return (-1); + } + + if (request->ip_data_mbuf == NULL) + request->ip_data_mbuf = m; + else + m_cat(request->ip_data_mbuf, m); + + request->ip_data_len += len; + *availablep -= len + padding; + } else + ICL_DEBUG("len 0"); + + if (*more_neededp) + ic->ic_receive_len = + icl_pdu_data_segment_receive_len(request); + + return (0); +} + +static int +icl_pdu_check_data_digest(struct icl_pdu *request, size_t *availablep) +{ + struct mbuf *m; + uint32_t received_digest, valid_digest; + + if (request->ip_conn->ic_data_crc32c == false) + return (0); + + if (request->ip_data_len == 0) + return (0); + + m = icl_conn_receive(request->ip_conn, ISCSI_DATA_DIGEST_SIZE); + if (m == NULL) { + ICL_DEBUG("failed to receive data digest"); + return (-1); + } + + CTASSERT(sizeof(received_digest) == ISCSI_DATA_DIGEST_SIZE); + memcpy(&received_digest, mtod(m, void *), ISCSI_DATA_DIGEST_SIZE); + m_freem(m); + + *availablep -= ISCSI_DATA_DIGEST_SIZE; + + /* + * Note that ip_data_mbuf also contains padding; since digest + * calculation is supposed to include that, we iterate over + * the entire ip_data_mbuf chain, not just ip_data_len bytes of it. + */ + valid_digest = icl_mbuf_to_crc32c(request->ip_data_mbuf); + if (received_digest != valid_digest) { + ICL_WARN("data digest check failed; got 0x%x, " + "should be 0x%x", received_digest, valid_digest); + return (-1); + } + + return (0); +} + +/* + * Somewhat contrary to the name, this attempts to receive only one + * "part" of PDU at a time; call it repeatedly until it returns non-NULL. + */ +static struct icl_pdu * +icl_conn_receive_pdu(struct icl_conn *ic, size_t *availablep) +{ + struct icl_pdu *request; + struct socket *so; + size_t len; + int error; + bool more_needed; + + so = ic->ic_socket; + + if (ic->ic_receive_state == ICL_CONN_STATE_BHS) { + KASSERT(ic->ic_receive_pdu == NULL, + ("ic->ic_receive_pdu != NULL")); + request = icl_pdu_new(ic, M_NOWAIT); + if (request == NULL) { + ICL_DEBUG("failed to allocate PDU; " + "dropping connection"); + icl_conn_fail(ic); + return (NULL); + } + ic->ic_receive_pdu = request; + } else { + KASSERT(ic->ic_receive_pdu != NULL, + ("ic->ic_receive_pdu == NULL")); + request = ic->ic_receive_pdu; + } + + if (*availablep < ic->ic_receive_len) { +#if 0 + ICL_DEBUG("not enough data; need %zd, " + "have %zd", ic->ic_receive_len, *availablep); +#endif + return (NULL); + } + + switch (ic->ic_receive_state) { + case ICL_CONN_STATE_BHS: + //ICL_DEBUG("receiving BHS"); + error = icl_pdu_receive_bhs(request, availablep); + if (error != 0) { + ICL_DEBUG("failed to receive BHS; " + "dropping connection"); + break; + } + + /* + * We don't enforce any limit for AHS length; + * its length is stored in 8 bit field. + */ + + len = icl_pdu_data_segment_length(request); + if (len > ic->ic_max_data_segment_length) { + ICL_WARN("received data segment " + "length %zd is larger than negotiated " + "MaxDataSegmentLength %zd; " + "dropping connection", + len, ic->ic_max_data_segment_length); + break; + } + + ic->ic_receive_state = ICL_CONN_STATE_AHS; + ic->ic_receive_len = icl_pdu_ahs_length(request); + break; + + case ICL_CONN_STATE_AHS: + //ICL_DEBUG("receiving AHS"); + error = icl_pdu_receive_ahs(request, availablep); + if (error != 0) { + ICL_DEBUG("failed to receive AHS; " + "dropping connection"); + break; + } + ic->ic_receive_state = ICL_CONN_STATE_HEADER_DIGEST; + if (ic->ic_header_crc32c == false) + ic->ic_receive_len = 0; + else + ic->ic_receive_len = ISCSI_HEADER_DIGEST_SIZE; + break; + + case ICL_CONN_STATE_HEADER_DIGEST: + //ICL_DEBUG("receiving header digest"); + error = icl_pdu_check_header_digest(request, availablep); + if (error != 0) { + ICL_DEBUG("header digest failed; " + "dropping connection"); + break; + } + + ic->ic_receive_state = ICL_CONN_STATE_DATA; + ic->ic_receive_len = + icl_pdu_data_segment_receive_len(request); + break; + + case ICL_CONN_STATE_DATA: + //ICL_DEBUG("receiving data segment"); + error = icl_pdu_receive_data_segment(request, availablep, + &more_needed); + if (error != 0) { + ICL_DEBUG("failed to receive data segment;" + "dropping connection"); + break; + } + + if (more_needed) + break; + + ic->ic_receive_state = ICL_CONN_STATE_DATA_DIGEST; + if (ic->ic_data_crc32c == false) + ic->ic_receive_len = 0; + else + ic->ic_receive_len = ISCSI_DATA_DIGEST_SIZE; + break; + + case ICL_CONN_STATE_DATA_DIGEST: + //ICL_DEBUG("receiving data digest"); + error = icl_pdu_check_data_digest(request, availablep); + if (error != 0) { + ICL_DEBUG("data digest failed; " + "dropping connection"); + break; + } + + /* + * We've received complete PDU; reset the receive state machine + * and return the PDU. + */ + ic->ic_receive_state = ICL_CONN_STATE_BHS; + ic->ic_receive_len = sizeof(struct iscsi_bhs); + ic->ic_receive_pdu = NULL; + return (request); + + default: + panic("invalid ic_receive_state %d\n", ic->ic_receive_state); + } + + if (error != 0) { + icl_pdu_free(request); + icl_conn_fail(ic); + } + + return (NULL); +} + +static void +icl_conn_receive_pdus(struct icl_conn *ic, size_t available) +{ + struct icl_pdu *response; + struct socket *so; + + so = ic->ic_socket; + + /* + * This can never happen; we're careful to only mess with ic->ic_socket + * pointer when the send/receive threads are not running. + */ + KASSERT(so != NULL, ("NULL socket")); + + for (;;) { + if (ic->ic_disconnecting) + return; + + if (so->so_error != 0) { + ICL_DEBUG("connection error %d; " + "dropping connection", so->so_error); + icl_conn_fail(ic); + return; + } + + /* + * Loop until we have a complete PDU or there is not enough + * data in the socket buffer. + */ + if (available < ic->ic_receive_len) { +#if 0 + ICL_DEBUG("not enough data; have %zd, " + "need %zd", available, + ic->ic_receive_len); +#endif + return; + } + + response = icl_conn_receive_pdu(ic, &available); + if (response == NULL) + continue; + + if (response->ip_ahs_len > 0) { + ICL_WARN("received PDU with unsupported " + "AHS; opcode 0x%x; dropping connection", + response->ip_bhs->bhs_opcode); + icl_pdu_free(response); + icl_conn_fail(ic); + return; + } + + (ic->ic_receive)(response); + } +} + +static void +icl_receive_thread(void *arg) +{ + struct icl_conn *ic; + size_t available; + struct socket *so; + + ic = arg; + so = ic->ic_socket; + + ICL_CONN_LOCK(ic); + ic->ic_receive_running = true; + ICL_CONN_UNLOCK(ic); + + for (;;) { + if (ic->ic_disconnecting) { + //ICL_DEBUG("terminating"); + ICL_CONN_LOCK(ic); + ic->ic_receive_running = false; + ICL_CONN_UNLOCK(ic); + kthread_exit(); + return; + } + + SOCKBUF_LOCK(&so->so_rcv); + available = so->so_rcv.sb_cc; + if (available < ic->ic_receive_len) { + so->so_rcv.sb_lowat = ic->ic_receive_len; + cv_wait(&ic->ic_receive_cv, &so->so_rcv.sb_mtx); + } + SOCKBUF_UNLOCK(&so->so_rcv); + + icl_conn_receive_pdus(ic, available); + } +} + +static int +icl_soupcall_receive(struct socket *so, void *arg, int waitflag) +{ + struct icl_conn *ic; + + ic = arg; + cv_signal(&ic->ic_receive_cv); + return (SU_OK); +} + +static int +icl_pdu_send(struct icl_pdu *request) +{ + size_t padding, pdu_len; + uint32_t digest, zero = 0; + int error, ok; + struct socket *so; + struct icl_conn *ic; + + ic = request->ip_conn; + so = request->ip_conn->ic_socket; + + ICL_CONN_LOCK_ASSERT(ic); + + icl_pdu_set_data_segment_length(request, request->ip_data_len); + + pdu_len = icl_pdu_size(request); + + if (ic->ic_header_crc32c) { + digest = icl_mbuf_to_crc32c(request->ip_bhs_mbuf); + ok = m_append(request->ip_bhs_mbuf, sizeof(digest), + (void *)&digest); + if (ok != 1) { + ICL_WARN("failed to append header digest"); + return (1); + } + } + + if (request->ip_data_len != 0) { + padding = icl_pdu_padding(request); + if (padding > 0) { + ok = m_append(request->ip_data_mbuf, padding, + (void *)&zero); + if (ok != 1) { + ICL_WARN("failed to append padding"); + return (1); + } + } + + if (ic->ic_data_crc32c) { + digest = icl_mbuf_to_crc32c(request->ip_data_mbuf); + + ok = m_append(request->ip_data_mbuf, sizeof(digest), + (void *)&digest); + if (ok != 1) { + ICL_WARN("failed to append header digest"); + return (1); + } + } + + m_cat(request->ip_bhs_mbuf, request->ip_data_mbuf); + request->ip_data_mbuf = NULL; + } + + request->ip_bhs_mbuf->m_pkthdr.len = pdu_len; + + error = sosend(so, NULL, NULL, request->ip_bhs_mbuf, + NULL, MSG_DONTWAIT, curthread); + request->ip_bhs_mbuf = NULL; /* Sosend consumes the mbuf. */ + if (error != 0) { + ICL_DEBUG("sosend error %d", error); + return (error); + } + + return (0); +} + +static void +icl_conn_send_pdus(struct icl_conn *ic) +{ + struct icl_pdu *request; + struct socket *so; + size_t available, size; + int error; + + ICL_CONN_LOCK_ASSERT(ic); + + so = ic->ic_socket; + + SOCKBUF_LOCK(&so->so_snd); + available = sbspace(&so->so_snd); + SOCKBUF_UNLOCK(&so->so_snd); + + while (!TAILQ_EMPTY(&ic->ic_to_send)) { + if (ic->ic_disconnecting) + return; + + request = TAILQ_FIRST(&ic->ic_to_send); + size = icl_pdu_size(request); + if (available < size) { + /* + * Set the low watermark on the socket, + * to avoid waking up until there is enough + * space. + */ + SOCKBUF_LOCK(&so->so_snd); + so->so_snd.sb_lowat = size; + SOCKBUF_UNLOCK(&so->so_snd); +#if 1 + ICL_DEBUG("no space to send; " + "have %zd, need %zd", + available, size); +#endif + return; + } + available -= size; + TAILQ_REMOVE(&ic->ic_to_send, request, ip_next); + error = icl_pdu_send(request); + if (error != 0) { + ICL_DEBUG("failed to send PDU; " + "dropping connection"); + icl_conn_fail(ic); + return; + } + icl_pdu_free(request); + } +} + +static void +icl_send_thread(void *arg) +{ + struct icl_conn *ic; + + ic = arg; + + ICL_CONN_LOCK(ic); + ic->ic_send_running = true; + ICL_CONN_UNLOCK(ic); + + for (;;) { + ICL_CONN_LOCK(ic); + if (ic->ic_disconnecting) { + //ICL_DEBUG("terminating"); + ic->ic_send_running = false; + ICL_CONN_UNLOCK(ic); + kthread_exit(); + return; + } + if (TAILQ_EMPTY(&ic->ic_to_send)) + cv_wait(&ic->ic_send_cv, &ic->ic_lock); + icl_conn_send_pdus(ic); + ICL_CONN_UNLOCK(ic); + } +} + +static int +icl_soupcall_send(struct socket *so, void *arg, int waitflag) +{ + struct icl_conn *ic; + + ic = arg; + cv_signal(&ic->ic_send_cv); + return (SU_OK); +} + +int +icl_pdu_append_data(struct icl_pdu *request, const void *addr, size_t len, int flags) +{ + struct mbuf *mb, *newmb; + size_t copylen, off = 0; + + KASSERT(len > 0, ("len == 0")); + + newmb = m_getm2(NULL, len, flags, MT_DATA, M_PKTHDR); + if (newmb == NULL) { + ICL_WARN("failed to allocate mbuf for %zd bytes", len); + return (ENOMEM); + } + + for (mb = newmb; mb != NULL; mb = mb->m_next) { + copylen = min(M_TRAILINGSPACE(mb), len - off); + memcpy(mtod(mb, char *), (const char *)addr + off, copylen); + mb->m_len = copylen; + off += copylen; + } + KASSERT(off == len, ("%s: off != len", __func__)); + + if (request->ip_data_mbuf == NULL) { + request->ip_data_mbuf = newmb; + request->ip_data_len = len; + } else { + m_cat(request->ip_data_mbuf, newmb); + request->ip_data_len += len; + } + + return (0); +} + +void +icl_pdu_get_data(struct icl_pdu *ip, size_t off, void *addr, size_t len) +{ + + m_copydata(ip->ip_data_mbuf, off, len, addr); +} + +void +icl_pdu_queue(struct icl_pdu *ip) +{ + struct icl_conn *ic; + + ic = ip->ip_conn; + + ICL_CONN_LOCK(ic); + if (ic->ic_disconnecting || ic->ic_socket == NULL) { + ICL_DEBUG("icl_pdu_queue on closed connection"); + ICL_CONN_UNLOCK(ic); + return; + } + TAILQ_INSERT_TAIL(&ic->ic_to_send, ip, ip_next); + ICL_CONN_UNLOCK(ic); + cv_signal(&ic->ic_send_cv); +} + +struct icl_conn * +icl_conn_new(void) +{ + struct icl_conn *ic; + + refcount_acquire(&icl_ncons); + + ic = uma_zalloc(icl_conn_zone, M_WAITOK | M_ZERO); + + TAILQ_INIT(&ic->ic_to_send); + mtx_init(&ic->ic_lock, "icl_lock", NULL, MTX_DEF); + cv_init(&ic->ic_send_cv, "icl_tx"); + cv_init(&ic->ic_receive_cv, "icl_rx"); + refcount_init(&ic->ic_outstanding_pdus, 0); + ic->ic_max_data_segment_length = ICL_MAX_DATA_SEGMENT_LENGTH; + + return (ic); +} + +void +icl_conn_free(struct icl_conn *ic) +{ + + mtx_destroy(&ic->ic_lock); + cv_destroy(&ic->ic_send_cv); + cv_destroy(&ic->ic_receive_cv); + uma_zfree(icl_conn_zone, ic); + refcount_release(&icl_ncons); +} + +static int +icl_conn_start(struct icl_conn *ic) +{ + size_t bufsize; + struct sockopt opt; + int error, one = 1; + + ICL_CONN_LOCK(ic); + + /* + * XXX: Ugly hack. + */ + if (ic->ic_socket == NULL) { + ICL_CONN_UNLOCK(ic); + return (EINVAL); + } + + ic->ic_receive_state = ICL_CONN_STATE_BHS; + ic->ic_receive_len = sizeof(struct iscsi_bhs); + ic->ic_disconnecting = false; + + ICL_CONN_UNLOCK(ic); + + /* + * Use max available sockbuf size for sending. Do it manually + * instead of sbreserve(9) to work around resource limits. + * + * XXX: This kind of sucks. On one hand, we don't currently support + * sending a part of data segment; we always do it in one piece, + * so we have to make sure it can fit in the socket buffer. + * Once I've implemented partial send, we'll get rid of this + * and use autoscaling. + */ + bufsize = (sizeof(struct iscsi_bhs) + + ic->ic_max_data_segment_length) * 8; + error = soreserve(ic->ic_socket, bufsize, bufsize); + if (error != 0) { + ICL_WARN("soreserve failed with error %d", error); + icl_conn_close(ic); + return (error); + } + + /* + * Disable Nagle. + */ + bzero(&opt, sizeof(opt)); + opt.sopt_dir = SOPT_SET; + opt.sopt_level = IPPROTO_TCP; + opt.sopt_name = TCP_NODELAY; + opt.sopt_val = &one; + opt.sopt_valsize = sizeof(one); + error = sosetopt(ic->ic_socket, &opt); + if (error != 0) { + ICL_WARN("disabling TCP_NODELAY failed with error %d", error); + icl_conn_close(ic); + return (error); + } + + /* + * Start threads. + */ + error = kthread_add(icl_send_thread, ic, NULL, NULL, 0, 0, "icltx"); + if (error != 0) { + ICL_WARN("kthread_add(9) failed with error %d", error); + icl_conn_close(ic); + return (error); + } + + error = kthread_add(icl_receive_thread, ic, NULL, NULL, 0, 0, "iclrx"); + if (error != 0) { + ICL_WARN("kthread_add(9) failed with error %d", error); + icl_conn_close(ic); + return (error); + } + + /* + * Register socket upcall, to get notified about incoming PDUs + * and free space to send outgoing ones. + */ + SOCKBUF_LOCK(&ic->ic_socket->so_snd); + soupcall_set(ic->ic_socket, SO_SND, icl_soupcall_send, ic); + SOCKBUF_UNLOCK(&ic->ic_socket->so_snd); + SOCKBUF_LOCK(&ic->ic_socket->so_rcv); + soupcall_set(ic->ic_socket, SO_RCV, icl_soupcall_receive, ic); + SOCKBUF_UNLOCK(&ic->ic_socket->so_rcv); + + return (0); +} + +int +icl_conn_handoff(struct icl_conn *ic, int fd) +{ + struct file *fp; + struct socket *so; + cap_rights_t rights; + int error; + + /* + * Steal the socket from userland. + */ + error = fget(curthread, fd, + cap_rights_init(&rights, CAP_SOCK_CLIENT), &fp); + if (error != 0) + return (error); + if (fp->f_type != DTYPE_SOCKET) { + fdrop(fp, curthread); + return (EINVAL); + } + so = fp->f_data; + if (so->so_type != SOCK_STREAM) { + fdrop(fp, curthread); + return (EINVAL); + } + + ICL_CONN_LOCK(ic); + + if (ic->ic_socket != NULL) { + ICL_CONN_UNLOCK(ic); + fdrop(fp, curthread); + return (EBUSY); + } + + ic->ic_socket = fp->f_data; + fp->f_ops = &badfileops; + fp->f_data = NULL; + fdrop(fp, curthread); + ICL_CONN_UNLOCK(ic); + + error = icl_conn_start(ic); + + return (error); +} + +void +icl_conn_shutdown(struct icl_conn *ic) +{ + + ICL_CONN_LOCK(ic); + if (ic->ic_socket == NULL) { + ICL_CONN_UNLOCK(ic); + return; + } + ICL_CONN_UNLOCK(ic); + + soshutdown(ic->ic_socket, SHUT_RDWR); +} + +void +icl_conn_close(struct icl_conn *ic) +{ + struct icl_pdu *pdu; + + ICL_CONN_LOCK(ic); + if (ic->ic_socket == NULL) { + ICL_CONN_UNLOCK(ic); + return; + } + + ic->ic_disconnecting = true; + + /* + * Wake up the threads, so they can properly terminate. + */ + cv_signal(&ic->ic_receive_cv); + cv_signal(&ic->ic_send_cv); + while (ic->ic_receive_running || ic->ic_send_running) { + //ICL_DEBUG("waiting for send/receive threads to terminate"); + ICL_CONN_UNLOCK(ic); + cv_signal(&ic->ic_receive_cv); + cv_signal(&ic->ic_send_cv); + pause("icl_close", 1 * hz); + ICL_CONN_LOCK(ic); + } + //ICL_DEBUG("send/receive threads terminated"); + + soclose(ic->ic_socket); + ic->ic_socket = NULL; + + if (ic->ic_receive_pdu != NULL) { + //ICL_DEBUG("freeing partially received PDU"); + icl_pdu_free(ic->ic_receive_pdu); + ic->ic_receive_pdu = NULL; + } + + /* + * Remove any outstanding PDUs from the send queue. + */ + while (!TAILQ_EMPTY(&ic->ic_to_send)) { + pdu = TAILQ_FIRST(&ic->ic_to_send); + TAILQ_REMOVE(&ic->ic_to_send, pdu, ip_next); + icl_pdu_free(pdu); + } + + KASSERT(TAILQ_EMPTY(&ic->ic_to_send), + ("destroying session with non-empty send queue")); + /* + * XXX + */ +#if 0 + KASSERT(ic->ic_outstanding_pdus == 0, + ("destroying session with %d outstanding PDUs", + ic->ic_outstanding_pdus)); +#endif + ICL_CONN_UNLOCK(ic); +} + +bool +icl_conn_connected(struct icl_conn *ic) +{ + + ICL_CONN_LOCK(ic); + if (ic->ic_socket == NULL) { + ICL_CONN_UNLOCK(ic); + return (false); + } + if (ic->ic_socket->so_error != 0) { + ICL_CONN_UNLOCK(ic); + return (false); + } + ICL_CONN_UNLOCK(ic); + return (true); +} + +#ifdef ICL_KERNEL_PROXY +int +icl_conn_handoff_sock(struct icl_conn *ic, struct socket *so) +{ + int error; + + if (so->so_type != SOCK_STREAM) + return (EINVAL); + + ICL_CONN_LOCK(ic); + if (ic->ic_socket != NULL) { + ICL_CONN_UNLOCK(ic); + return (EBUSY); + } + ic->ic_socket = so; + ICL_CONN_UNLOCK(ic); + + error = icl_conn_start(ic); + + return (error); +} +#endif /* ICL_KERNEL_PROXY */ + +static int +icl_unload(void) +{ + + if (icl_ncons != 0) + return (EBUSY); + + uma_zdestroy(icl_conn_zone); + uma_zdestroy(icl_pdu_zone); + + return (0); +} + +static void +icl_load(void) +{ + + icl_conn_zone = uma_zcreate("icl_conn", + sizeof(struct icl_conn), NULL, NULL, NULL, NULL, + UMA_ALIGN_PTR, UMA_ZONE_NOFREE); + icl_pdu_zone = uma_zcreate("icl_pdu", + sizeof(struct icl_pdu), NULL, NULL, NULL, NULL, + UMA_ALIGN_PTR, UMA_ZONE_NOFREE); + + refcount_init(&icl_ncons, 0); +} + +static int +icl_modevent(module_t mod, int what, void *arg) +{ + + switch (what) { + case MOD_LOAD: + icl_load(); + return (0); + case MOD_UNLOAD: + return (icl_unload()); + default: + return (EINVAL); + } +} + +moduledata_t icl_data = { + "icl", + icl_modevent, + 0 +}; + +DECLARE_MODULE(icl, icl_data, SI_SUB_DRIVERS, SI_ORDER_FIRST); +MODULE_VERSION(icl, 1); |
