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freebsd-nq/sys/dev/iscsi/icl.c

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/*-
* 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/capsicum.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/protosw.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;
SYSCTL_INT(_kern_icl, OID_AUTO, debug, CTLFLAG_RWTUN,
&debug, 0, "Enable debug messages");
static int coalesce = 1;
SYSCTL_INT(_kern_icl, OID_AUTO, coalesce, CTLFLAG_RWTUN,
&coalesce, 0, "Try to coalesce PDUs before sending");
static int partial_receive_len = 128 * 1024;
SYSCTL_INT(_kern_icl, OID_AUTO, partial_receive_len, CTLFLAG_RWTUN,
&partial_receive_len, 0, "Minimum read size for partially received "
"data segment");
static int sendspace = 1048576;
SYSCTL_INT(_kern_icl, OID_AUTO, sendspace, CTLFLAG_RWTUN,
&sendspace, 0, "Default send socket buffer size");
static int recvspace = 1048576;
SYSCTL_INT(_kern_icl, OID_AUTO, recvspace, CTLFLAG_RWTUN,
&recvspace, 0, "Default receive socket buffer size");
static uma_zone_t icl_conn_zone;
static uma_zone_t icl_pdu_zone;
static volatile u_int icl_ncons;
#define ICL_DEBUG(X, ...) \
do { \
if (debug > 1) \
printf("%s: " X "\n", __func__, ## __VA_ARGS__);\
} while (0)
#define ICL_WARN(X, ...) \
do { \
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)
#define ICL_CONN_LOCK_ASSERT_NOT(X) mtx_assert(X->ic_lock, MA_NOTOWNED)
STAILQ_HEAD(icl_pdu_stailq, icl_pdu);
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;
#ifdef DIAGNOSTIC
refcount_acquire(&ic->ic_outstanding_pdus);
#endif
ip = uma_zalloc(icl_pdu_zone, flags | M_ZERO);
if (ip == NULL) {
ICL_WARN("failed to allocate %zd bytes", sizeof(*ip));
#ifdef DIAGNOSTIC
refcount_release(&ic->ic_outstanding_pdus);
#endif
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);
#ifdef DIAGNOSTIC
refcount_release(&ic->ic_outstanding_pdus);
#endif
}
/*
* 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_data_len != 0 && 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);
m_copydata(m, 0, ISCSI_HEADER_DIGEST_SIZE, (void *)&received_digest);
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);
m_copydata(m, 0, ISCSI_DATA_DIGEST_SIZE, (void *)&received_digest);
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);
error = EINVAL;
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 (request->ip_data_len == 0 || 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");
break;
}
/*
* Set the low watermark, to be checked by
* soreadable() in icl_soupcall_receive()
* to avoid unneccessary wakeups until there
* is enough data received to read the PDU.
*/
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);
} else
so->so_rcv.sb_lowat = so->so_rcv.sb_hiwat + 1;
SOCKBUF_UNLOCK(&so->so_rcv);
icl_conn_receive_pdus(ic, available);
}
ICL_CONN_LOCK(ic);
ic->ic_receive_running = false;
ICL_CONN_UNLOCK(ic);
kthread_exit();
}
static int
icl_soupcall_receive(struct socket *so, void *arg, int waitflag)
{
struct icl_conn *ic;
if (!soreadable(so))
return (SU_OK);
ic = arg;
cv_signal(&ic->ic_receive_cv);
return (SU_OK);
}
static int
icl_pdu_finalize(struct icl_pdu *request)
{
size_t padding, pdu_len;
uint32_t digest, zero = 0;
int ok;
struct icl_conn *ic;
ic = request->ip_conn;
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 data 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;
return (0);
}
static void
icl_conn_send_pdus(struct icl_conn *ic, struct icl_pdu_stailq *queue)
{
struct icl_pdu *request, *request2;
struct socket *so;
size_t available, size, size2;
int coalesced, error;
ICL_CONN_LOCK_ASSERT_NOT(ic);
so = ic->ic_socket;
SOCKBUF_LOCK(&so->so_snd);
/*
* Check how much space do we have for transmit. We can't just
* call sosend() and retry when we get EWOULDBLOCK or EMSGSIZE,
* as it always frees the mbuf chain passed to it, even in case
* of error.
*/
available = sbspace(&so->so_snd);
/*
* Notify the socket upcall that we don't need wakeups
* for the time being.
*/
so->so_snd.sb_lowat = so->so_snd.sb_hiwat + 1;
SOCKBUF_UNLOCK(&so->so_snd);
while (!STAILQ_EMPTY(queue)) {
if (ic->ic_disconnecting)
return;
request = STAILQ_FIRST(queue);
size = icl_pdu_size(request);
if (available < size) {
/*
* Set the low watermark, to be checked by
* sowriteable() in icl_soupcall_send()
* to avoid unneccessary wakeups until there
* is enough space for the PDU to fit.
*/
SOCKBUF_LOCK(&so->so_snd);
available = sbspace(&so->so_snd);
if (available < size) {
#if 1
ICL_DEBUG("no space to send; "
"have %zd, need %zd",
available, size);
#endif
so->so_snd.sb_lowat = size;
SOCKBUF_UNLOCK(&so->so_snd);
return;
}
SOCKBUF_UNLOCK(&so->so_snd);
}
STAILQ_REMOVE_HEAD(queue, ip_next);
error = icl_pdu_finalize(request);
if (error != 0) {
ICL_DEBUG("failed to finalize PDU; "
"dropping connection");
icl_conn_fail(ic);
icl_pdu_free(request);
return;
}
if (coalesce) {
coalesced = 1;
for (;;) {
request2 = STAILQ_FIRST(queue);
if (request2 == NULL)
break;
size2 = icl_pdu_size(request2);
if (available < size + size2)
break;
STAILQ_REMOVE_HEAD(queue, ip_next);
error = icl_pdu_finalize(request2);
if (error != 0) {
ICL_DEBUG("failed to finalize PDU; "
"dropping connection");
icl_conn_fail(ic);
icl_pdu_free(request);
icl_pdu_free(request2);
return;
}
m_cat(request->ip_bhs_mbuf, request2->ip_bhs_mbuf);
request2->ip_bhs_mbuf = NULL;
request->ip_bhs_mbuf->m_pkthdr.len += size2;
size += size2;
STAILQ_REMOVE_AFTER(queue, request, ip_next);
icl_pdu_free(request2);
coalesced++;
}
#if 0
if (coalesced > 1) {
ICL_DEBUG("coalesced %d PDUs into %zd bytes",
coalesced, size);
}
#endif
}
available -= size;
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("failed to send PDU, error %d; "
"dropping connection", error);
icl_conn_fail(ic);
icl_pdu_free(request);
return;
}
icl_pdu_free(request);
}
}
static void
icl_send_thread(void *arg)
{
struct icl_conn *ic;
struct icl_pdu_stailq queue;
ic = arg;
STAILQ_INIT(&queue);
ICL_CONN_LOCK(ic);
ic->ic_send_running = true;
for (;;) {
if (ic->ic_disconnecting) {
//ICL_DEBUG("terminating");
break;
}
for (;;) {
/*
* If the local queue is empty, populate it from
* the main one. This way the icl_conn_send_pdus()
* can go through all the queued PDUs without holding
* any locks.
*/
if (STAILQ_EMPTY(&queue))
STAILQ_SWAP(&ic->ic_to_send, &queue, icl_pdu);
ic->ic_check_send_space = false;
ICL_CONN_UNLOCK(ic);
icl_conn_send_pdus(ic, &queue);
ICL_CONN_LOCK(ic);
/*
* The icl_soupcall_send() was called since the last
* call to sbspace(); go around;
*/
if (ic->ic_check_send_space)
continue;
/*
* Local queue is empty, but we still have PDUs
* in the main one; go around.
*/
if (STAILQ_EMPTY(&queue) &&
!STAILQ_EMPTY(&ic->ic_to_send))
continue;
/*
* There might be some stuff in the local queue,
* which didn't get sent due to not having enough send
* space. Wait for socket upcall.
*/
break;
}
cv_wait(&ic->ic_send_cv, ic->ic_lock);
}
/*
* We're exiting; move PDUs back to the main queue, so they can
* get freed properly. At this point ordering doesn't matter.
*/
STAILQ_CONCAT(&ic->ic_to_send, &queue);
ic->ic_send_running = false;
ICL_CONN_UNLOCK(ic);
kthread_exit();
}
static int
icl_soupcall_send(struct socket *so, void *arg, int waitflag)
{
struct icl_conn *ic;
if (!sowriteable(so))
return (SU_OK);
ic = arg;
ICL_CONN_LOCK(ic);
ic->ic_check_send_space = true;
ICL_CONN_UNLOCK(ic);
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_ASSERT(ic);
if (ic->ic_disconnecting || ic->ic_socket == NULL) {
ICL_DEBUG("icl_pdu_queue on closed connection");
icl_pdu_free(ip);
return;
}
if (!STAILQ_EMPTY(&ic->ic_to_send)) {
STAILQ_INSERT_TAIL(&ic->ic_to_send, ip, ip_next);
/*
* If the queue is not empty, someone else had already
* signaled the send thread; no need to do that again,
* just return.
*/
return;
}
STAILQ_INSERT_TAIL(&ic->ic_to_send, ip, ip_next);
cv_signal(&ic->ic_send_cv);
}
struct icl_conn *
icl_conn_new(const char *name, struct mtx *lock)
{
struct icl_conn *ic;
refcount_acquire(&icl_ncons);
ic = uma_zalloc(icl_conn_zone, M_WAITOK | M_ZERO);
STAILQ_INIT(&ic->ic_to_send);
ic->ic_lock = lock;
cv_init(&ic->ic_send_cv, "icl_tx");
cv_init(&ic->ic_receive_cv, "icl_rx");
#ifdef DIAGNOSTIC
refcount_init(&ic->ic_outstanding_pdus, 0);
#endif
ic->ic_max_data_segment_length = ICL_MAX_DATA_SEGMENT_LENGTH;
ic->ic_name = name;
return (ic);
}
void
icl_conn_free(struct icl_conn *ic)
{
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 minspace;
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);
/*
* For sendspace, this is required because the current code cannot
* send a PDU in pieces; thus, the minimum buffer size is equal
* to the maximum PDU size. "+4" is to account for possible padding.
*
* What we should actually do here is to use autoscaling, but set
* some minimal buffer size to "minspace". I don't know a way to do
* that, though.
*/
minspace = sizeof(struct iscsi_bhs) + ic->ic_max_data_segment_length +
ISCSI_HEADER_DIGEST_SIZE + ISCSI_DATA_DIGEST_SIZE + 4;
if (sendspace < minspace) {
ICL_WARN("kern.icl.sendspace too low; must be at least %zd",
minspace);
sendspace = minspace;
}
if (recvspace < minspace) {
ICL_WARN("kern.icl.recvspace too low; must be at least %zd",
minspace);
recvspace = minspace;
}
error = soreserve(ic->ic_socket, sendspace, recvspace);
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, "%stx",
ic->ic_name);
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, "%srx",
ic->ic_name);
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;
ICL_CONN_LOCK_ASSERT_NOT(ic);
/*
* 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_ASSERT_NOT(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_ASSERT_NOT(ic);
ICL_CONN_LOCK(ic);
if (ic->ic_socket == NULL) {
ICL_CONN_UNLOCK(ic);
return;
}
/*
* Deregister socket upcalls.
*/
ICL_CONN_UNLOCK(ic);
SOCKBUF_LOCK(&ic->ic_socket->so_snd);
if (ic->ic_socket->so_snd.sb_upcall != NULL)
soupcall_clear(ic->ic_socket, SO_SND);
SOCKBUF_UNLOCK(&ic->ic_socket->so_snd);
SOCKBUF_LOCK(&ic->ic_socket->so_rcv);
if (ic->ic_socket->so_rcv.sb_upcall != NULL)
soupcall_clear(ic->ic_socket, SO_RCV);
SOCKBUF_UNLOCK(&ic->ic_socket->so_rcv);
ICL_CONN_LOCK(ic);
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");
ICL_CONN_UNLOCK(ic);
soclose(ic->ic_socket);
ICL_CONN_LOCK(ic);
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 (!STAILQ_EMPTY(&ic->ic_to_send)) {
pdu = STAILQ_FIRST(&ic->ic_to_send);
STAILQ_REMOVE_HEAD(&ic->ic_to_send, ip_next);
icl_pdu_free(pdu);
}
KASSERT(STAILQ_EMPTY(&ic->ic_to_send),
("destroying session with non-empty send queue"));
#ifdef DIAGNOSTIC
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_ASSERT_NOT(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;
ICL_CONN_LOCK_ASSERT_NOT(ic);
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, 0);
icl_pdu_zone = uma_zcreate("icl_pdu",
sizeof(struct icl_pdu), NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, 0);
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);
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