// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2010-2011 EIA Electronics,
// Kurt Van Dijck <[email protected]>
// Copyright (c) 2018 Protonic,
// Robin van der Gracht <[email protected]>
// Copyright (c) 2017-2019 Pengutronix,
// Marc Kleine-Budde <[email protected]>
// Copyright (c) 2017-2019 Pengutronix,
// Oleksij Rempel <[email protected]>
#include <linux/can/skb.h>
#include "j1939-priv.h"
#define J1939_XTP_TX_RETRY_LIMIT 100
#define J1939_ETP_PGN_CTL 0xc800
#define J1939_ETP_PGN_DAT 0xc700
#define J1939_TP_PGN_CTL 0xec00
#define J1939_TP_PGN_DAT 0xeb00
#define J1939_TP_CMD_RTS 0x10
#define J1939_TP_CMD_CTS 0x11
#define J1939_TP_CMD_EOMA 0x13
#define J1939_TP_CMD_BAM 0x20
#define J1939_TP_CMD_ABORT 0xff
#define J1939_ETP_CMD_RTS 0x14
#define J1939_ETP_CMD_CTS 0x15
#define J1939_ETP_CMD_DPO 0x16
#define J1939_ETP_CMD_EOMA 0x17
#define J1939_ETP_CMD_ABORT 0xff
enum j1939_xtp_abort {
J1939_XTP_NO_ABORT = 0,
J1939_XTP_ABORT_BUSY = 1,
/* Already in one or more connection managed sessions and
* cannot support another.
*
* EALREADY:
* Operation already in progress
*/
J1939_XTP_ABORT_RESOURCE = 2,
/* System resources were needed for another task so this
* connection managed session was terminated.
*
* EMSGSIZE:
* The socket type requires that message be sent atomically,
* and the size of the message to be sent made this
* impossible.
*/
J1939_XTP_ABORT_TIMEOUT = 3,
/* A timeout occurred and this is the connection abort to
* close the session.
*
* EHOSTUNREACH:
* The destination host cannot be reached (probably because
* the host is down or a remote router cannot reach it).
*/
J1939_XTP_ABORT_GENERIC = 4,
/* CTS messages received when data transfer is in progress
*
* EBADMSG:
* Not a data message
*/
J1939_XTP_ABORT_FAULT = 5,
/* Maximal retransmit request limit reached
*
* ENOTRECOVERABLE:
* State not recoverable
*/
J1939_XTP_ABORT_UNEXPECTED_DATA = 6,
/* Unexpected data transfer packet
*
* ENOTCONN:
* Transport endpoint is not connected
*/
J1939_XTP_ABORT_BAD_SEQ = 7,
/* Bad sequence number (and software is not able to recover)
*
* EILSEQ:
* Illegal byte sequence
*/
J1939_XTP_ABORT_DUP_SEQ = 8,
/* Duplicate sequence number (and software is not able to
* recover)
*/
J1939_XTP_ABORT_EDPO_UNEXPECTED = 9,
/* Unexpected EDPO packet (ETP) or Message size > 1785 bytes
* (TP)
*/
J1939_XTP_ABORT_BAD_EDPO_PGN = 10,
/* Unexpected EDPO PGN (PGN in EDPO is bad) */
J1939_XTP_ABORT_EDPO_OUTOF_CTS = 11,
/* EDPO number of packets is greater than CTS */
J1939_XTP_ABORT_BAD_EDPO_OFFSET = 12,
/* Bad EDPO offset */
J1939_XTP_ABORT_OTHER_DEPRECATED = 13,
/* Deprecated. Use 250 instead (Any other reason) */
J1939_XTP_ABORT_ECTS_UNXPECTED_PGN = 14,
/* Unexpected ECTS PGN (PGN in ECTS is bad) */
J1939_XTP_ABORT_ECTS_TOO_BIG = 15,
/* ECTS requested packets exceeds message size */
J1939_XTP_ABORT_OTHER = 250,
/* Any other reason (if a Connection Abort reason is
* identified that is not listed in the table use code 250)
*/
};
static unsigned int j1939_tp_block = 255;
static unsigned int j1939_tp_packet_delay;
static unsigned int j1939_tp_padding = 1;
/* helpers */
static const char *j1939_xtp_abort_to_str(enum j1939_xtp_abort abort)
{
switch (abort) {
case J1939_XTP_ABORT_BUSY:
return "Already in one or more connection managed sessions and cannot support another.";
case J1939_XTP_ABORT_RESOURCE:
return "System resources were needed for another task so this connection managed session was terminated.";
case J1939_XTP_ABORT_TIMEOUT:
return "A timeout occurred and this is the connection abort to close the session.";
case J1939_XTP_ABORT_GENERIC:
return "CTS messages received when data transfer is in progress";
case J1939_XTP_ABORT_FAULT:
return "Maximal retransmit request limit reached";
case J1939_XTP_ABORT_UNEXPECTED_DATA:
return "Unexpected data transfer packet";
case J1939_XTP_ABORT_BAD_SEQ:
return "Bad sequence number (and software is not able to recover)";
case J1939_XTP_ABORT_DUP_SEQ:
return "Duplicate sequence number (and software is not able to recover)";
case J1939_XTP_ABORT_EDPO_UNEXPECTED:
return "Unexpected EDPO packet (ETP) or Message size > 1785 bytes (TP)";
case J1939_XTP_ABORT_BAD_EDPO_PGN:
return "Unexpected EDPO PGN (PGN in EDPO is bad)";
case J1939_XTP_ABORT_EDPO_OUTOF_CTS:
return "EDPO number of packets is greater than CTS";
case J1939_XTP_ABORT_BAD_EDPO_OFFSET:
return "Bad EDPO offset";
case J1939_XTP_ABORT_OTHER_DEPRECATED:
return "Deprecated. Use 250 instead (Any other reason)";
case J1939_XTP_ABORT_ECTS_UNXPECTED_PGN:
return "Unexpected ECTS PGN (PGN in ECTS is bad)";
case J1939_XTP_ABORT_ECTS_TOO_BIG:
return "ECTS requested packets exceeds message size";
case J1939_XTP_ABORT_OTHER:
return "Any other reason (if a Connection Abort reason is identified that is not listed in the table use code 250)";
default:
return "<unknown>";
}
}
static int j1939_xtp_abort_to_errno(struct j1939_priv *priv,
enum j1939_xtp_abort abort)
{
int err;
switch (abort) {
case J1939_XTP_NO_ABORT:
WARN_ON_ONCE(abort == J1939_XTP_NO_ABORT);
err = 0;
break;
case J1939_XTP_ABORT_BUSY:
err = EALREADY;
break;
case J1939_XTP_ABORT_RESOURCE:
err = EMSGSIZE;
break;
case J1939_XTP_ABORT_TIMEOUT:
err = EHOSTUNREACH;
break;
case J1939_XTP_ABORT_GENERIC:
err = EBADMSG;
break;
case J1939_XTP_ABORT_FAULT:
err = ENOTRECOVERABLE;
break;
case J1939_XTP_ABORT_UNEXPECTED_DATA:
err = ENOTCONN;
break;
case J1939_XTP_ABORT_BAD_SEQ:
err = EILSEQ;
break;
case J1939_XTP_ABORT_DUP_SEQ:
err = EPROTO;
break;
case J1939_XTP_ABORT_EDPO_UNEXPECTED:
err = EPROTO;
break;
case J1939_XTP_ABORT_BAD_EDPO_PGN:
err = EPROTO;
break;
case J1939_XTP_ABORT_EDPO_OUTOF_CTS:
err = EPROTO;
break;
case J1939_XTP_ABORT_BAD_EDPO_OFFSET:
err = EPROTO;
break;
case J1939_XTP_ABORT_OTHER_DEPRECATED:
err = EPROTO;
break;
case J1939_XTP_ABORT_ECTS_UNXPECTED_PGN:
err = EPROTO;
break;
case J1939_XTP_ABORT_ECTS_TOO_BIG:
err = EPROTO;
break;
case J1939_XTP_ABORT_OTHER:
err = EPROTO;
break;
default:
netdev_warn(priv->ndev, "Unknown abort code %i", abort);
err = EPROTO;
}
return err;
}
static inline void j1939_session_list_lock(struct j1939_priv *priv)
{
spin_lock_bh(&priv->active_session_list_lock);
}
static inline void j1939_session_list_unlock(struct j1939_priv *priv)
{
spin_unlock_bh(&priv->active_session_list_lock);
}
void j1939_session_get(struct j1939_session *session)
{
kref_get(&session->kref);
}
/* session completion functions */
static void __j1939_session_drop(struct j1939_session *session)
{
if (!session->transmission)
return;
j1939_sock_pending_del(session->sk);
sock_put(session->sk);
}
static void j1939_session_destroy(struct j1939_session *session)
{
struct sk_buff *skb;
if (session->transmission) {
if (session->err)
j1939_sk_errqueue(session, J1939_ERRQUEUE_TX_ABORT);
else
j1939_sk_errqueue(session, J1939_ERRQUEUE_TX_ACK);
} else if (session->err) {
j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT);
}
netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
WARN_ON_ONCE(!list_empty(&session->sk_session_queue_entry));
WARN_ON_ONCE(!list_empty(&session->active_session_list_entry));
while ((skb = skb_dequeue(&session->skb_queue)) != NULL) {
/* drop ref taken in j1939_session_skb_queue() */
skb_unref(skb);
kfree_skb(skb);
}
__j1939_session_drop(session);
j1939_priv_put(session->priv);
kfree(session);
}
static void __j1939_session_release(struct kref *kref)
{
struct j1939_session *session = container_of(kref, struct j1939_session,
kref);
j1939_session_destroy(session);
}
void j1939_session_put(struct j1939_session *session)
{
kref_put(&session->kref, __j1939_session_release);
}
static void j1939_session_txtimer_cancel(struct j1939_session *session)
{
if (hrtimer_cancel(&session->txtimer))
j1939_session_put(session);
}
static void j1939_session_rxtimer_cancel(struct j1939_session *session)
{
if (hrtimer_cancel(&session->rxtimer))
j1939_session_put(session);
}
void j1939_session_timers_cancel(struct j1939_session *session)
{
j1939_session_txtimer_cancel(session);
j1939_session_rxtimer_cancel(session);
}
static inline bool j1939_cb_is_broadcast(const struct j1939_sk_buff_cb *skcb)
{
return (!skcb->addr.dst_name && (skcb->addr.da == 0xff));
}
static void j1939_session_skb_drop_old(struct j1939_session *session)
{
struct sk_buff *do_skb;
struct j1939_sk_buff_cb *do_skcb;
unsigned int offset_start;
unsigned long flags;
if (skb_queue_len(&session->skb_queue) < 2)
return;
offset_start = session->pkt.tx_acked * 7;
spin_lock_irqsave(&session->skb_queue.lock, flags);
do_skb = skb_peek(&session->skb_queue);
do_skcb = j1939_skb_to_cb(do_skb);
if ((do_skcb->offset + do_skb->len) < offset_start) {
__skb_unlink(do_skb, &session->skb_queue);
/* drop ref taken in j1939_session_skb_queue() */
skb_unref(do_skb);
spin_unlock_irqrestore(&session->skb_queue.lock, flags);
kfree_skb(do_skb);
} else {
spin_unlock_irqrestore(&session->skb_queue.lock, flags);
}
}
void j1939_session_skb_queue(struct j1939_session *session,
struct sk_buff *skb)
{
struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
struct j1939_priv *priv = session->priv;
j1939_ac_fixup(priv, skb);
if (j1939_address_is_unicast(skcb->addr.da) &&
priv->ents[skcb->addr.da].nusers)
skcb->flags |= J1939_ECU_LOCAL_DST;
skcb->flags |= J1939_ECU_LOCAL_SRC;
skb_get(skb);
skb_queue_tail(&session->skb_queue, skb);
}
static struct
sk_buff *j1939_session_skb_get_by_offset(struct j1939_session *session,
unsigned int offset_start)
{
struct j1939_priv *priv = session->priv;
struct j1939_sk_buff_cb *do_skcb;
struct sk_buff *skb = NULL;
struct sk_buff *do_skb;
unsigned long flags;
spin_lock_irqsave(&session->skb_queue.lock, flags);
skb_queue_walk(&session->skb_queue, do_skb) {
do_skcb = j1939_skb_to_cb(do_skb);
if (offset_start >= do_skcb->offset &&
offset_start < (do_skcb->offset + do_skb->len)) {
skb = do_skb;
}
}
if (skb)
skb_get(skb);
spin_unlock_irqrestore(&session->skb_queue.lock, flags);
if (!skb)
netdev_dbg(priv->ndev, "%s: 0x%p: no skb found for start: %i, queue size: %i\n",
__func__, session, offset_start,
skb_queue_len(&session->skb_queue));
return skb;
}
static struct sk_buff *j1939_session_skb_get(struct j1939_session *session)
{
unsigned int offset_start;
offset_start = session->pkt.dpo * 7;
return j1939_session_skb_get_by_offset(session, offset_start);
}
/* see if we are receiver
* returns 0 for broadcasts, although we will receive them
*/
static inline int j1939_tp_im_receiver(const struct j1939_sk_buff_cb *skcb)
{
return skcb->flags & J1939_ECU_LOCAL_DST;
}
/* see if we are sender */
static inline int j1939_tp_im_transmitter(const struct j1939_sk_buff_cb *skcb)
{
return skcb->flags & J1939_ECU_LOCAL_SRC;
}
/* see if we are involved as either receiver or transmitter */
static int j1939_tp_im_involved(const struct j1939_sk_buff_cb *skcb, bool swap)
{
if (swap)
return j1939_tp_im_receiver(skcb);
else
return j1939_tp_im_transmitter(skcb);
}
static int j1939_tp_im_involved_anydir(struct j1939_sk_buff_cb *skcb)
{
return skcb->flags & (J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
}
/* extract pgn from flow-ctl message */
static inline pgn_t j1939_xtp_ctl_to_pgn(const u8 *dat)
{
pgn_t pgn;
pgn = (dat[7] << 16) | (dat[6] << 8) | (dat[5] << 0);
if (j1939_pgn_is_pdu1(pgn))
pgn &= 0xffff00;
return pgn;
}
static inline unsigned int j1939_tp_ctl_to_size(const u8 *dat)
{
return (dat[2] << 8) + (dat[1] << 0);
}
static inline unsigned int j1939_etp_ctl_to_packet(const u8 *dat)
{
return (dat[4] << 16) | (dat[3] << 8) | (dat[2] << 0);
}
static inline unsigned int j1939_etp_ctl_to_size(const u8 *dat)
{
return (dat[4] << 24) | (dat[3] << 16) |
(dat[2] << 8) | (dat[1] << 0);
}
/* find existing session:
* reverse: swap cb's src & dst
* there is no problem with matching broadcasts, since
* broadcasts (no dst, no da) would never call this
* with reverse == true
*/
static bool j1939_session_match(struct j1939_addr *se_addr,
struct j1939_addr *sk_addr, bool reverse)
{
if (se_addr->type != sk_addr->type)
return false;
if (reverse) {
if (se_addr->src_name) {
if (se_addr->src_name != sk_addr->dst_name)
return false;
} else if (se_addr->sa != sk_addr->da) {
return false;
}
if (se_addr->dst_name) {
if (se_addr->dst_name != sk_addr->src_name)
return false;
} else if (se_addr->da != sk_addr->sa) {
return false;
}
} else {
if (se_addr->src_name) {
if (se_addr->src_name != sk_addr->src_name)
return false;
} else if (se_addr->sa != sk_addr->sa) {
return false;
}
if (se_addr->dst_name) {
if (se_addr->dst_name != sk_addr->dst_name)
return false;
} else if (se_addr->da != sk_addr->da) {
return false;
}
}
return true;
}
static struct
j1939_session *j1939_session_get_by_addr_locked(struct j1939_priv *priv,
struct list_head *root,
struct j1939_addr *addr,
bool reverse, bool transmitter)
{
struct j1939_session *session;
lockdep_assert_held(&priv->active_session_list_lock);
list_for_each_entry(session, root, active_session_list_entry) {
j1939_session_get(session);
if (j1939_session_match(&session->skcb.addr, addr, reverse) &&
session->transmission == transmitter)
return session;
j1939_session_put(session);
}
return NULL;
}
static struct
j1939_session *j1939_session_get_simple(struct j1939_priv *priv,
struct sk_buff *skb)
{
struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
struct j1939_session *session;
lockdep_assert_held(&priv->active_session_list_lock);
list_for_each_entry(session, &priv->active_session_list,
active_session_list_entry) {
j1939_session_get(session);
if (session->skcb.addr.type == J1939_SIMPLE &&
session->tskey == skcb->tskey && session->sk == skb->sk)
return session;
j1939_session_put(session);
}
return NULL;
}
static struct
j1939_session *j1939_session_get_by_addr(struct j1939_priv *priv,
struct j1939_addr *addr,
bool reverse, bool transmitter)
{
struct j1939_session *session;
j1939_session_list_lock(priv);
session = j1939_session_get_by_addr_locked(priv,
&priv->active_session_list,
addr, reverse, transmitter);
j1939_session_list_unlock(priv);
return session;
}
static void j1939_skbcb_swap(struct j1939_sk_buff_cb *skcb)
{
u8 tmp = 0;
swap(skcb->addr.dst_name, skcb->addr.src_name);
swap(skcb->addr.da, skcb->addr.sa);
/* swap SRC and DST flags, leave other untouched */
if (skcb->flags & J1939_ECU_LOCAL_SRC)
tmp |= J1939_ECU_LOCAL_DST;
if (skcb->flags & J1939_ECU_LOCAL_DST)
tmp |= J1939_ECU_LOCAL_SRC;
skcb->flags &= ~(J1939_ECU_LOCAL_SRC | J1939_ECU_LOCAL_DST);
skcb->flags |= tmp;
}
static struct
sk_buff *j1939_tp_tx_dat_new(struct j1939_priv *priv,
const struct j1939_sk_buff_cb *re_skcb,
bool ctl,
bool swap_src_dst)
{
struct sk_buff *skb;
struct j1939_sk_buff_cb *skcb;
skb = alloc_skb(sizeof(struct can_frame) + sizeof(struct can_skb_priv),
GFP_ATOMIC);
if (unlikely(!skb))
return ERR_PTR(-ENOMEM);
skb->dev = priv->ndev;
can_skb_reserve(skb);
can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
can_skb_prv(skb)->skbcnt = 0;
/* reserve CAN header */
skb_reserve(skb, offsetof(struct can_frame, data));
/* skb->cb must be large enough to hold a j1939_sk_buff_cb structure */
BUILD_BUG_ON(sizeof(skb->cb) < sizeof(*re_skcb));
memcpy(skb->cb, re_skcb, sizeof(*re_skcb));
skcb = j1939_skb_to_cb(skb);
if (swap_src_dst)
j1939_skbcb_swap(skcb);
if (ctl) {
if (skcb->addr.type == J1939_ETP)
skcb->addr.pgn = J1939_ETP_PGN_CTL;
else
skcb->addr.pgn = J1939_TP_PGN_CTL;
} else {
if (skcb->addr.type == J1939_ETP)
skcb->addr.pgn = J1939_ETP_PGN_DAT;
else
skcb->addr.pgn = J1939_TP_PGN_DAT;
}
return skb;
}
/* TP transmit packet functions */
static int j1939_tp_tx_dat(struct j1939_session *session,
const u8 *dat, int len)
{
struct j1939_priv *priv = session->priv;
struct sk_buff *skb;
skb = j1939_tp_tx_dat_new(priv, &session->skcb,
false, false);
if (IS_ERR(skb))
return PTR_ERR(skb);
skb_put_data(skb, dat, len);
if (j1939_tp_padding && len < 8)
memset(skb_put(skb, 8 - len), 0xff, 8 - len);
return j1939_send_one(priv, skb);
}
static int j1939_xtp_do_tx_ctl(struct j1939_priv *priv,
const struct j1939_sk_buff_cb *re_skcb,
bool swap_src_dst, pgn_t pgn, const u8 *dat)
{
struct sk_buff *skb;
u8 *skdat;
if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
return 0;
skb = j1939_tp_tx_dat_new(priv, re_skcb, true, swap_src_dst);
if (IS_ERR(skb))
return PTR_ERR(skb);
skdat = skb_put(skb, 8);
memcpy(skdat, dat, 5);
skdat[5] = (pgn >> 0);
skdat[6] = (pgn >> 8);
skdat[7] = (pgn >> 16);
return j1939_send_one(priv, skb);
}
static inline int j1939_tp_tx_ctl(struct j1939_session *session,
bool swap_src_dst, const u8 *dat)
{
struct j1939_priv *priv = session->priv;
return j1939_xtp_do_tx_ctl(priv, &session->skcb,
swap_src_dst,
session->skcb.addr.pgn, dat);
}
static int j1939_xtp_tx_abort(struct j1939_priv *priv,
const struct j1939_sk_buff_cb *re_skcb,
bool swap_src_dst,
enum j1939_xtp_abort err,
pgn_t pgn)
{
u8 dat[5];
if (!j1939_tp_im_involved(re_skcb, swap_src_dst))
return 0;
memset(dat, 0xff, sizeof(dat));
dat[0] = J1939_TP_CMD_ABORT;
dat[1] = err;
return j1939_xtp_do_tx_ctl(priv, re_skcb, swap_src_dst, pgn, dat);
}
void j1939_tp_schedule_txtimer(struct j1939_session *session, int msec)
{
j1939_session_get(session);
hrtimer_start(&session->txtimer, ms_to_ktime(msec),
HRTIMER_MODE_REL_SOFT);
}
static inline void j1939_tp_set_rxtimeout(struct j1939_session *session,
int msec)
{
j1939_session_rxtimer_cancel(session);
j1939_session_get(session);
hrtimer_start(&session->rxtimer, ms_to_ktime(msec),
HRTIMER_MODE_REL_SOFT);
}
static int j1939_session_tx_rts(struct j1939_session *session)
{
u8 dat[8];
int ret;
memset(dat, 0xff, sizeof(dat));
dat[1] = (session->total_message_size >> 0);
dat[2] = (session->total_message_size >> 8);
dat[3] = session->pkt.total;
if (session->skcb.addr.type == J1939_ETP) {
dat[0] = J1939_ETP_CMD_RTS;
dat[1] = (session->total_message_size >> 0);
dat[2] = (session->total_message_size >> 8);
dat[3] = (session->total_message_size >> 16);
dat[4] = (session->total_message_size >> 24);
} else if (j1939_cb_is_broadcast(&session->skcb)) {
dat[0] = J1939_TP_CMD_BAM;
/* fake cts for broadcast */
session->pkt.tx = 0;
} else {
dat[0] = J1939_TP_CMD_RTS;
dat[4] = dat[3];
}
if (dat[0] == session->last_txcmd)
/* done already */
return 0;
ret = j1939_tp_tx_ctl(session, false, dat);
if (ret < 0)
return ret;
session->last_txcmd = dat[0];
if (dat[0] == J1939_TP_CMD_BAM) {
j1939_tp_schedule_txtimer(session, 50);
j1939_tp_set_rxtimeout(session, 250);
} else {
j1939_tp_set_rxtimeout(session, 1250);
}
netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
return 0;
}
static int j1939_session_tx_dpo(struct j1939_session *session)
{
unsigned int pkt;
u8 dat[8];
int ret;
memset(dat, 0xff, sizeof(dat));
dat[0] = J1939_ETP_CMD_DPO;
session->pkt.dpo = session->pkt.tx_acked;
pkt = session->pkt.dpo;
dat[1] = session->pkt.last - session->pkt.tx_acked;
dat[2] = (pkt >> 0);
dat[3] = (pkt >> 8);
dat[4] = (pkt >> 16);
ret = j1939_tp_tx_ctl(session, false, dat);
if (ret < 0)
return ret;
session->last_txcmd = dat[0];
j1939_tp_set_rxtimeout(session, 1250);
session->pkt.tx = session->pkt.tx_acked;
netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
return 0;
}
static int j1939_session_tx_dat(struct j1939_session *session)
{
struct j1939_priv *priv = session->priv;
struct j1939_sk_buff_cb *se_skcb;
int offset, pkt_done, pkt_end;
unsigned int len, pdelay;
struct sk_buff *se_skb;
const u8 *tpdat;
int ret = 0;
u8 dat[8];
se_skb = j1939_session_skb_get_by_offset(session, session->pkt.tx * 7);
if (!se_skb)
return -ENOBUFS;
se_skcb = j1939_skb_to_cb(se_skb);
tpdat = se_skb->data;
ret = 0;
pkt_done = 0;
if (session->skcb.addr.type != J1939_ETP &&
j1939_cb_is_broadcast(&session->skcb))
pkt_end = session->pkt.total;
else
pkt_end = session->pkt.last;
while (session->pkt.tx < pkt_end) {
dat[0] = session->pkt.tx - session->pkt.dpo + 1;
offset = (session->pkt.tx * 7) - se_skcb->offset;
len = se_skb->len - offset;
if (len > 7)
len = 7;
if (offset + len > se_skb->len) {
netdev_err_once(priv->ndev,
"%s: 0x%p: requested data outside of queued buffer: offset %i, len %i, pkt.tx: %i\n",
__func__, session, se_skcb->offset,
se_skb->len , session->pkt.tx);
ret = -EOVERFLOW;
goto out_free;
}
if (!len) {
ret = -ENOBUFS;
break;
}
memcpy(&dat[1], &tpdat[offset], len);
ret = j1939_tp_tx_dat(session, dat, len + 1);
if (ret < 0) {
/* ENOBUFS == CAN interface TX queue is full */
if (ret != -ENOBUFS)
netdev_alert(priv->ndev,
"%s: 0x%p: queue data error: %i\n",
__func__, session, ret);
break;
}
session->last_txcmd = 0xff;
pkt_done++;
session->pkt.tx++;
pdelay = j1939_cb_is_broadcast(&session->skcb) ? 50 :
j1939_tp_packet_delay;
if (session->pkt.tx < session->pkt.total && pdelay) {
j1939_tp_schedule_txtimer(session, pdelay);
break;
}
}
if (pkt_done)
j1939_tp_set_rxtimeout(session, 250);
out_free:
if (ret)
kfree_skb(se_skb);
else
consume_skb(se_skb);
return ret;
}
static int j1939_xtp_txnext_transmiter(struct j1939_session *session)
{
struct j1939_priv *priv = session->priv;
int ret = 0;
if (!j1939_tp_im_transmitter(&session->skcb)) {
netdev_alert(priv->ndev, "%s: 0x%p: called by not transmitter!\n",
__func__, session);
return -EINVAL;
}
switch (session->last_cmd) {
case 0:
ret = j1939_session_tx_rts(session);
break;
case J1939_ETP_CMD_CTS:
if (session->last_txcmd != J1939_ETP_CMD_DPO) {
ret = j1939_session_tx_dpo(session);
if (ret)
return ret;
}
fallthrough;
case J1939_TP_CMD_CTS:
case 0xff: /* did some data */
case J1939_ETP_CMD_DPO:
case J1939_TP_CMD_BAM:
ret = j1939_session_tx_dat(session);
break;
default:
netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
__func__, session, session->last_cmd);
}
return ret;
}
static int j1939_session_tx_cts(struct j1939_session *session)
{
struct j1939_priv *priv = session->priv;
unsigned int pkt, len;
int ret;
u8 dat[8];
if (!j1939_sk_recv_match(priv, &session->skcb))
return -ENOENT;
len = session->pkt.total - session->pkt.rx;
len = min3(len, session->pkt.block, j1939_tp_block ?: 255);
memset(dat, 0xff, sizeof(dat));
if (session->skcb.addr.type == J1939_ETP) {
pkt = session->pkt.rx + 1;
dat[0] = J1939_ETP_CMD_CTS;
dat[1] = len;
dat[2] = (pkt >> 0);
dat[3] = (pkt >> 8);
dat[4] = (pkt >> 16);
} else {
dat[0] = J1939_TP_CMD_CTS;
dat[1] = len;
dat[2] = session->pkt.rx + 1;
}
if (dat[0] == session->last_txcmd)
/* done already */
return 0;
ret = j1939_tp_tx_ctl(session, true, dat);
if (ret < 0)
return ret;
if (len)
/* only mark cts done when len is set */
session->last_txcmd = dat[0];
j1939_tp_set_rxtimeout(session, 1250);
netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
return 0;
}
static int j1939_session_tx_eoma(struct j1939_session *session)
{
struct j1939_priv *priv = session->priv;
u8 dat[8];
int ret;
if (!j1939_sk_recv_match(priv, &session->skcb))
return -ENOENT;
memset(dat, 0xff, sizeof(dat));
if (session->skcb.addr.type == J1939_ETP) {
dat[0] = J1939_ETP_CMD_EOMA;
dat[1] = session->total_message_size >> 0;
dat[2] = session->total_message_size >> 8;
dat[3] = session->total_message_size >> 16;
dat[4] = session->total_message_size >> 24;
} else {
dat[0] = J1939_TP_CMD_EOMA;
dat[1] = session->total_message_size;
dat[2] = session->total_message_size >> 8;
dat[3] = session->pkt.total;
}
if (dat[0] == session->last_txcmd)
/* done already */
return 0;
ret = j1939_tp_tx_ctl(session, true, dat);
if (ret < 0)
return ret;
session->last_txcmd = dat[0];
/* wait for the EOMA packet to come in */
j1939_tp_set_rxtimeout(session, 1250);
netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
return 0;
}
static int j1939_xtp_txnext_receiver(struct j1939_session *session)
{
struct j1939_priv *priv = session->priv;
int ret = 0;
if (!j1939_tp_im_receiver(&session->skcb)) {
netdev_alert(priv->ndev, "%s: 0x%p: called by not receiver!\n",
__func__, session);
return -EINVAL;
}
switch (session->last_cmd) {
case J1939_TP_CMD_RTS:
case J1939_ETP_CMD_RTS:
ret = j1939_session_tx_cts(session);
break;
case J1939_ETP_CMD_CTS:
case J1939_TP_CMD_CTS:
case 0xff: /* did some data */
case J1939_ETP_CMD_DPO:
if ((session->skcb.addr.type == J1939_TP &&
j1939_cb_is_broadcast(&session->skcb)))
break;
if (session->pkt.rx >= session->pkt.total) {
ret = j1939_session_tx_eoma(session);
} else if (session->pkt.rx >= session->pkt.last) {
session->last_txcmd = 0;
ret = j1939_session_tx_cts(session);
}
break;
default:
netdev_alert(priv->ndev, "%s: 0x%p: unexpected last_cmd: %x\n",
__func__, session, session->last_cmd);
}
return ret;
}
static int j1939_simple_txnext(struct j1939_session *session)
{
struct j1939_priv *priv = session->priv;
struct sk_buff *se_skb = j1939_session_skb_get(session);
struct sk_buff *skb;
int ret;
if (!se_skb)
return 0;
skb = skb_clone(se_skb, GFP_ATOMIC);
if (!skb) {
ret = -ENOMEM;
goto out_free;
}
can_skb_set_owner(skb, se_skb->sk);
j1939_tp_set_rxtimeout(session, J1939_SIMPLE_ECHO_TIMEOUT_MS);
ret = j1939_send_one(priv, skb);
if (ret)
goto out_free;
j1939_sk_errqueue(session, J1939_ERRQUEUE_TX_SCHED);
j1939_sk_queue_activate_next(session);
out_free:
if (ret)
kfree_skb(se_skb);
else
consume_skb(se_skb);
return ret;
}
static bool j1939_session_deactivate_locked(struct j1939_session *session)
{
bool active = false;
lockdep_assert_held(&session->priv->active_session_list_lock);
if (session->state >= J1939_SESSION_ACTIVE &&
session->state < J1939_SESSION_ACTIVE_MAX) {
active = true;
list_del_init(&session->active_session_list_entry);
session->state = J1939_SESSION_DONE;
j1939_session_put(session);
}
return active;
}
static bool j1939_session_deactivate(struct j1939_session *session)
{
struct j1939_priv *priv = session->priv;
bool active;
j1939_session_list_lock(priv);
active = j1939_session_deactivate_locked(session);
j1939_session_list_unlock(priv);
return active;
}
static void
j1939_session_deactivate_activate_next(struct j1939_session *session)
{
if (j1939_session_deactivate(session))
j1939_sk_queue_activate_next(session);
}
static void __j1939_session_cancel(struct j1939_session *session,
enum j1939_xtp_abort err)
{
struct j1939_priv *priv = session->priv;
WARN_ON_ONCE(!err);
lockdep_assert_held(&session->priv->active_session_list_lock);
session->err = j1939_xtp_abort_to_errno(priv, err);
session->state = J1939_SESSION_WAITING_ABORT;
/* do not send aborts on incoming broadcasts */
if (!j1939_cb_is_broadcast(&session->skcb)) {
j1939_xtp_tx_abort(priv, &session->skcb,
!session->transmission,
err, session->skcb.addr.pgn);
}
if (session->sk)
j1939_sk_send_loop_abort(session->sk, session->err);
}
static void j1939_session_cancel(struct j1939_session *session,
enum j1939_xtp_abort err)
{
j1939_session_list_lock(session->priv);
if (session->state >= J1939_SESSION_ACTIVE &&
session->state < J1939_SESSION_WAITING_ABORT) {
j1939_tp_set_rxtimeout(session, J1939_XTP_ABORT_TIMEOUT_MS);
__j1939_session_cancel(session, err);
}
j1939_session_list_unlock(session->priv);
if (!session->sk)
j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT);
}
static enum hrtimer_restart j1939_tp_txtimer(struct hrtimer *hrtimer)
{
struct j1939_session *session =
container_of(hrtimer, struct j1939_session, txtimer);
struct j1939_priv *priv = session->priv;
int ret = 0;
if (session->skcb.addr.type == J1939_SIMPLE) {
ret = j1939_simple_txnext(session);
} else {
if (session->transmission)
ret = j1939_xtp_txnext_transmiter(session);
else
ret = j1939_xtp_txnext_receiver(session);
}
switch (ret) {
case -ENOBUFS:
/* Retry limit is currently arbitrary chosen */
if (session->tx_retry < J1939_XTP_TX_RETRY_LIMIT) {
session->tx_retry++;
j1939_tp_schedule_txtimer(session,
10 + get_random_u32_below(16));
} else {
netdev_alert(priv->ndev, "%s: 0x%p: tx retry count reached\n",
__func__, session);
session->err = -ENETUNREACH;
j1939_session_rxtimer_cancel(session);
j1939_session_deactivate_activate_next(session);
}
break;
case -ENETDOWN:
/* In this case we should get a netdev_event(), all active
* sessions will be cleared by j1939_cancel_active_session().
* So handle this as an error, but let
* j1939_cancel_active_session() do the cleanup including
* propagation of the error to user space.
*/
break;
case -EOVERFLOW:
j1939_session_cancel(session, J1939_XTP_ABORT_ECTS_TOO_BIG);
break;
case 0:
session->tx_retry = 0;
break;
default:
netdev_alert(priv->ndev, "%s: 0x%p: tx aborted with unknown reason: %i\n",
__func__, session, ret);
if (session->skcb.addr.type != J1939_SIMPLE) {
j1939_session_cancel(session, J1939_XTP_ABORT_OTHER);
} else {
session->err = ret;
j1939_session_rxtimer_cancel(session);
j1939_session_deactivate_activate_next(session);
}
}
j1939_session_put(session);
return HRTIMER_NORESTART;
}
static void j1939_session_completed(struct j1939_session *session)
{
struct sk_buff *se_skb;
if (!session->transmission) {
se_skb = j1939_session_skb_get(session);
/* distribute among j1939 receivers */
j1939_sk_recv(session->priv, se_skb);
consume_skb(se_skb);
}
j1939_session_deactivate_activate_next(session);
}
static enum hrtimer_restart j1939_tp_rxtimer(struct hrtimer *hrtimer)
{
struct j1939_session *session = container_of(hrtimer,
struct j1939_session,
rxtimer);
struct j1939_priv *priv = session->priv;
if (session->state == J1939_SESSION_WAITING_ABORT) {
netdev_alert(priv->ndev, "%s: 0x%p: abort rx timeout. Force session deactivation\n",
__func__, session);
j1939_session_deactivate_activate_next(session);
} else if (session->skcb.addr.type == J1939_SIMPLE) {
netdev_alert(priv->ndev, "%s: 0x%p: Timeout. Failed to send simple message.\n",
__func__, session);
/* The message is probably stuck in the CAN controller and can
* be send as soon as CAN bus is in working state again.
*/
session->err = -ETIME;
j1939_session_deactivate(session);
} else {
j1939_session_list_lock(session->priv);
if (session->state >= J1939_SESSION_ACTIVE &&
session->state < J1939_SESSION_ACTIVE_MAX) {
netdev_alert(priv->ndev, "%s: 0x%p: rx timeout, send abort\n",
__func__, session);
j1939_session_get(session);
hrtimer_start(&session->rxtimer,
ms_to_ktime(J1939_XTP_ABORT_TIMEOUT_MS),
HRTIMER_MODE_REL_SOFT);
__j1939_session_cancel(session, J1939_XTP_ABORT_TIMEOUT);
}
j1939_session_list_unlock(session->priv);
if (!session->sk)
j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT);
}
j1939_session_put(session);
return HRTIMER_NORESTART;
}
static bool j1939_xtp_rx_cmd_bad_pgn(struct j1939_session *session,
const struct sk_buff *skb)
{
const struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
pgn_t pgn = j1939_xtp_ctl_to_pgn(skb->data);
struct j1939_priv *priv = session->priv;
enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
u8 cmd = skb->data[0];
if (session->skcb.addr.pgn == pgn)
return false;
switch (cmd) {
case J1939_TP_CMD_BAM:
abort = J1939_XTP_NO_ABORT;
break;
case J1939_ETP_CMD_RTS:
fallthrough;
case J1939_TP_CMD_RTS:
abort = J1939_XTP_ABORT_BUSY;
break;
case J1939_ETP_CMD_CTS:
fallthrough;
case J1939_TP_CMD_CTS:
abort = J1939_XTP_ABORT_ECTS_UNXPECTED_PGN;
break;
case J1939_ETP_CMD_DPO:
abort = J1939_XTP_ABORT_BAD_EDPO_PGN;
break;
case J1939_ETP_CMD_EOMA:
fallthrough;
case J1939_TP_CMD_EOMA:
abort = J1939_XTP_ABORT_OTHER;
break;
case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
abort = J1939_XTP_NO_ABORT;
break;
default:
WARN_ON_ONCE(1);
break;
}
netdev_warn(priv->ndev, "%s: 0x%p: CMD 0x%02x with PGN 0x%05x for running session with different PGN 0x%05x.\n",
__func__, session, cmd, pgn, session->skcb.addr.pgn);
if (abort != J1939_XTP_NO_ABORT)
j1939_xtp_tx_abort(priv, skcb, true, abort, pgn);
return true;
}
static void j1939_xtp_rx_abort_one(struct j1939_priv *priv, struct sk_buff *skb,
bool reverse, bool transmitter)
{
struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
struct j1939_session *session;
u8 abort = skb->data[1];
session = j1939_session_get_by_addr(priv, &skcb->addr, reverse,
transmitter);
if (!session)
return;
if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
goto abort_put;
netdev_info(priv->ndev, "%s: 0x%p: 0x%05x: (%u) %s\n", __func__,
session, j1939_xtp_ctl_to_pgn(skb->data), abort,
j1939_xtp_abort_to_str(abort));
j1939_session_timers_cancel(session);
session->err = j1939_xtp_abort_to_errno(priv, abort);
if (session->sk)
j1939_sk_send_loop_abort(session->sk, session->err);
else
j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_ABORT);
j1939_session_deactivate_activate_next(session);
abort_put:
j1939_session_put(session);
}
/* abort packets may come in 2 directions */
static void
j1939_xtp_rx_abort(struct j1939_priv *priv, struct sk_buff *skb,
bool transmitter)
{
j1939_xtp_rx_abort_one(priv, skb, false, transmitter);
j1939_xtp_rx_abort_one(priv, skb, true, transmitter);
}
static void
j1939_xtp_rx_eoma_one(struct j1939_session *session, struct sk_buff *skb)
{
struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
const u8 *dat;
int len;
if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
return;
dat = skb->data;
if (skcb->addr.type == J1939_ETP)
len = j1939_etp_ctl_to_size(dat);
else
len = j1939_tp_ctl_to_size(dat);
if (session->total_message_size != len) {
netdev_warn_once(session->priv->ndev,
"%s: 0x%p: Incorrect size. Expected: %i; got: %i.\n",
__func__, session, session->total_message_size,
len);
}
netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
session->pkt.tx_acked = session->pkt.total;
j1939_session_timers_cancel(session);
/* transmitted without problems */
j1939_session_completed(session);
}
static void
j1939_xtp_rx_eoma(struct j1939_priv *priv, struct sk_buff *skb,
bool transmitter)
{
struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
struct j1939_session *session;
session = j1939_session_get_by_addr(priv, &skcb->addr, true,
transmitter);
if (!session)
return;
j1939_xtp_rx_eoma_one(session, skb);
j1939_session_put(session);
}
static void
j1939_xtp_rx_cts_one(struct j1939_session *session, struct sk_buff *skb)
{
enum j1939_xtp_abort err = J1939_XTP_ABORT_FAULT;
unsigned int pkt;
const u8 *dat;
dat = skb->data;
if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
return;
netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
if (session->last_cmd == dat[0]) {
err = J1939_XTP_ABORT_DUP_SEQ;
goto out_session_cancel;
}
if (session->skcb.addr.type == J1939_ETP)
pkt = j1939_etp_ctl_to_packet(dat);
else
pkt = dat[2];
if (!pkt)
goto out_session_cancel;
else if (dat[1] > session->pkt.block /* 0xff for etp */)
goto out_session_cancel;
/* set packet counters only when not CTS(0) */
session->pkt.tx_acked = pkt - 1;
j1939_session_skb_drop_old(session);
session->pkt.last = session->pkt.tx_acked + dat[1];
if (session->pkt.last > session->pkt.total)
/* safety measure */
session->pkt.last = session->pkt.total;
/* TODO: do not set tx here, do it in txtimer */
session->pkt.tx = session->pkt.tx_acked;
session->last_cmd = dat[0];
if (dat[1]) {
j1939_tp_set_rxtimeout(session, 1250);
if (session->transmission) {
if (session->pkt.tx_acked)
j1939_sk_errqueue(session,
J1939_ERRQUEUE_TX_SCHED);
j1939_session_txtimer_cancel(session);
j1939_tp_schedule_txtimer(session, 0);
}
} else {
/* CTS(0) */
j1939_tp_set_rxtimeout(session, 550);
}
return;
out_session_cancel:
j1939_session_timers_cancel(session);
j1939_session_cancel(session, err);
}
static void
j1939_xtp_rx_cts(struct j1939_priv *priv, struct sk_buff *skb, bool transmitter)
{
struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
struct j1939_session *session;
session = j1939_session_get_by_addr(priv, &skcb->addr, true,
transmitter);
if (!session)
return;
j1939_xtp_rx_cts_one(session, skb);
j1939_session_put(session);
}
static struct j1939_session *j1939_session_new(struct j1939_priv *priv,
struct sk_buff *skb, size_t size)
{
struct j1939_session *session;
struct j1939_sk_buff_cb *skcb;
session = kzalloc(sizeof(*session), gfp_any());
if (!session)
return NULL;
INIT_LIST_HEAD(&session->active_session_list_entry);
INIT_LIST_HEAD(&session->sk_session_queue_entry);
kref_init(&session->kref);
j1939_priv_get(priv);
session->priv = priv;
session->total_message_size = size;
session->state = J1939_SESSION_NEW;
skb_queue_head_init(&session->skb_queue);
skb_queue_tail(&session->skb_queue, skb);
skcb = j1939_skb_to_cb(skb);
memcpy(&session->skcb, skcb, sizeof(session->skcb));
hrtimer_init(&session->txtimer, CLOCK_MONOTONIC,
HRTIMER_MODE_REL_SOFT);
session->txtimer.function = j1939_tp_txtimer;
hrtimer_init(&session->rxtimer, CLOCK_MONOTONIC,
HRTIMER_MODE_REL_SOFT);
session->rxtimer.function = j1939_tp_rxtimer;
netdev_dbg(priv->ndev, "%s: 0x%p: sa: %02x, da: %02x\n",
__func__, session, skcb->addr.sa, skcb->addr.da);
return session;
}
static struct
j1939_session *j1939_session_fresh_new(struct j1939_priv *priv,
int size,
const struct j1939_sk_buff_cb *rel_skcb)
{
struct sk_buff *skb;
struct j1939_sk_buff_cb *skcb;
struct j1939_session *session;
skb = alloc_skb(size + sizeof(struct can_skb_priv), GFP_ATOMIC);
if (unlikely(!skb))
return NULL;
skb->dev = priv->ndev;
can_skb_reserve(skb);
can_skb_prv(skb)->ifindex = priv->ndev->ifindex;
can_skb_prv(skb)->skbcnt = 0;
skcb = j1939_skb_to_cb(skb);
memcpy(skcb, rel_skcb, sizeof(*skcb));
session = j1939_session_new(priv, skb, size);
if (!session) {
kfree_skb(skb);
return NULL;
}
/* alloc data area */
skb_put(skb, size);
/* skb is recounted in j1939_session_new() */
return session;
}
int j1939_session_activate(struct j1939_session *session)
{
struct j1939_priv *priv = session->priv;
struct j1939_session *active = NULL;
int ret = 0;
j1939_session_list_lock(priv);
if (session->skcb.addr.type != J1939_SIMPLE)
active = j1939_session_get_by_addr_locked(priv,
&priv->active_session_list,
&session->skcb.addr, false,
session->transmission);
if (active) {
j1939_session_put(active);
ret = -EAGAIN;
} else {
WARN_ON_ONCE(session->state != J1939_SESSION_NEW);
list_add_tail(&session->active_session_list_entry,
&priv->active_session_list);
j1939_session_get(session);
session->state = J1939_SESSION_ACTIVE;
netdev_dbg(session->priv->ndev, "%s: 0x%p\n",
__func__, session);
}
j1939_session_list_unlock(priv);
return ret;
}
static struct
j1939_session *j1939_xtp_rx_rts_session_new(struct j1939_priv *priv,
struct sk_buff *skb)
{
enum j1939_xtp_abort abort = J1939_XTP_NO_ABORT;
struct j1939_sk_buff_cb skcb = *j1939_skb_to_cb(skb);
struct j1939_session *session;
const u8 *dat;
int len, ret;
pgn_t pgn;
netdev_dbg(priv->ndev, "%s\n", __func__);
dat = skb->data;
pgn = j1939_xtp_ctl_to_pgn(dat);
skcb.addr.pgn = pgn;
if (!j1939_sk_recv_match(priv, &skcb))
return NULL;
if (skcb.addr.type == J1939_ETP) {
len = j1939_etp_ctl_to_size(dat);
if (len > J1939_MAX_ETP_PACKET_SIZE)
abort = J1939_XTP_ABORT_FAULT;
else if (len > priv->tp_max_packet_size)
abort = J1939_XTP_ABORT_RESOURCE;
else if (len <= J1939_MAX_TP_PACKET_SIZE)
abort = J1939_XTP_ABORT_FAULT;
} else {
len = j1939_tp_ctl_to_size(dat);
if (len > J1939_MAX_TP_PACKET_SIZE)
abort = J1939_XTP_ABORT_FAULT;
else if (len > priv->tp_max_packet_size)
abort = J1939_XTP_ABORT_RESOURCE;
else if (len < J1939_MIN_TP_PACKET_SIZE)
abort = J1939_XTP_ABORT_FAULT;
}
if (abort != J1939_XTP_NO_ABORT) {
j1939_xtp_tx_abort(priv, &skcb, true, abort, pgn);
return NULL;
}
session = j1939_session_fresh_new(priv, len, &skcb);
if (!session) {
j1939_xtp_tx_abort(priv, &skcb, true,
J1939_XTP_ABORT_RESOURCE, pgn);
return NULL;
}
/* initialize the control buffer: plain copy */
session->pkt.total = (len + 6) / 7;
session->pkt.block = 0xff;
if (skcb.addr.type != J1939_ETP) {
if (dat[3] != session->pkt.total)
netdev_alert(priv->ndev, "%s: 0x%p: strange total, %u != %u\n",
__func__, session, session->pkt.total,
dat[3]);
session->pkt.total = dat[3];
session->pkt.block = min(dat[3], dat[4]);
}
session->pkt.rx = 0;
session->pkt.tx = 0;
session->tskey = priv->rx_tskey++;
j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_RTS);
ret = j1939_session_activate(session);
if (ret) {
/* Entering this scope indicates an issue with the J1939 bus.
* Possible scenarios include:
* - A time lapse occurred, and a new session was initiated
* due to another packet being sent correctly. This could
* have been caused by too long interrupt, debugger, or being
* out-scheduled by another task.
* - The bus is receiving numerous erroneous packets, either
* from a malfunctioning device or during a test scenario.
*/
netdev_alert(priv->ndev, "%s: 0x%p: concurrent session with same addr (%02x %02x) is already active.\n",
__func__, session, skcb.addr.sa, skcb.addr.da);
j1939_session_put(session);
return NULL;
}
return session;
}
static int j1939_xtp_rx_rts_session_active(struct j1939_session *session,
struct sk_buff *skb)
{
struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
struct j1939_priv *priv = session->priv;
if (!session->transmission) {
if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
return -EBUSY;
/* RTS on active session */
j1939_session_timers_cancel(session);
j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
}
if (session->last_cmd != 0) {
/* we received a second rts on the same connection */
netdev_alert(priv->ndev, "%s: 0x%p: connection exists (%02x %02x). last cmd: %x\n",
__func__, session, skcb->addr.sa, skcb->addr.da,
session->last_cmd);
j1939_session_timers_cancel(session);
j1939_session_cancel(session, J1939_XTP_ABORT_BUSY);
if (session->transmission)
j1939_session_deactivate_activate_next(session);
return -EBUSY;
}
if (session->skcb.addr.sa != skcb->addr.sa ||
session->skcb.addr.da != skcb->addr.da)
netdev_warn(priv->ndev, "%s: 0x%p: session->skcb.addr.sa=0x%02x skcb->addr.sa=0x%02x session->skcb.addr.da=0x%02x skcb->addr.da=0x%02x\n",
__func__, session,
session->skcb.addr.sa, skcb->addr.sa,
session->skcb.addr.da, skcb->addr.da);
/* make sure 'sa' & 'da' are correct !
* They may be 'not filled in yet' for sending
* skb's, since they did not pass the Address Claim ever.
*/
session->skcb.addr.sa = skcb->addr.sa;
session->skcb.addr.da = skcb->addr.da;
netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
return 0;
}
static void j1939_xtp_rx_rts(struct j1939_priv *priv, struct sk_buff *skb,
bool transmitter)
{
struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
struct j1939_session *session;
u8 cmd = skb->data[0];
session = j1939_session_get_by_addr(priv, &skcb->addr, false,
transmitter);
if (!session) {
if (transmitter) {
/* If we're the transmitter and this function is called,
* we received our own RTS. A session has already been
* created.
*
* For some reasons however it might have been destroyed
* already. So don't create a new one here (using
* "j1939_xtp_rx_rts_session_new()") as this will be a
* receiver session.
*
* The reasons the session is already destroyed might
* be:
* - user space closed socket was and the session was
* aborted
* - session was aborted due to external abort message
*/
return;
}
session = j1939_xtp_rx_rts_session_new(priv, skb);
if (!session) {
if (cmd == J1939_TP_CMD_BAM && j1939_sk_recv_match(priv, skcb))
netdev_info(priv->ndev, "%s: failed to create TP BAM session\n",
__func__);
return;
}
} else {
if (j1939_xtp_rx_rts_session_active(session, skb)) {
j1939_session_put(session);
return;
}
}
session->last_cmd = cmd;
if (cmd == J1939_TP_CMD_BAM) {
if (!session->transmission)
j1939_tp_set_rxtimeout(session, 750);
} else {
if (!session->transmission) {
j1939_session_txtimer_cancel(session);
j1939_tp_schedule_txtimer(session, 0);
}
j1939_tp_set_rxtimeout(session, 1250);
}
j1939_session_put(session);
}
static void j1939_xtp_rx_dpo_one(struct j1939_session *session,
struct sk_buff *skb)
{
const u8 *dat = skb->data;
if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
return;
netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
/* transmitted without problems */
session->pkt.dpo = j1939_etp_ctl_to_packet(skb->data);
session->last_cmd = dat[0];
j1939_tp_set_rxtimeout(session, 750);
if (!session->transmission)
j1939_sk_errqueue(session, J1939_ERRQUEUE_RX_DPO);
}
static void j1939_xtp_rx_dpo(struct j1939_priv *priv, struct sk_buff *skb,
bool transmitter)
{
struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
struct j1939_session *session;
session = j1939_session_get_by_addr(priv, &skcb->addr, false,
transmitter);
if (!session) {
netdev_info(priv->ndev,
"%s: no connection found\n", __func__);
return;
}
j1939_xtp_rx_dpo_one(session, skb);
j1939_session_put(session);
}
static void j1939_xtp_rx_dat_one(struct j1939_session *session,
struct sk_buff *skb)
{
enum j1939_xtp_abort abort = J1939_XTP_ABORT_FAULT;
struct j1939_priv *priv = session->priv;
struct j1939_sk_buff_cb *skcb, *se_skcb;
struct sk_buff *se_skb = NULL;
const u8 *dat;
u8 *tpdat;
int offset;
int nbytes;
bool final = false;
bool remain = false;
bool do_cts_eoma = false;
int packet;
skcb = j1939_skb_to_cb(skb);
dat = skb->data;
if (skb->len != 8) {
/* makes no sense */
abort = J1939_XTP_ABORT_UNEXPECTED_DATA;
goto out_session_cancel;
}
switch (session->last_cmd) {
case 0xff:
break;
case J1939_ETP_CMD_DPO:
if (skcb->addr.type == J1939_ETP)
break;
fallthrough;
case J1939_TP_CMD_BAM:
fallthrough;
case J1939_TP_CMD_CTS:
if (skcb->addr.type != J1939_ETP)
break;
fallthrough;
default:
netdev_info(priv->ndev, "%s: 0x%p: last %02x\n", __func__,
session, session->last_cmd);
goto out_session_cancel;
}
packet = (dat[0] - 1 + session->pkt.dpo);
if (packet > session->pkt.total ||
(session->pkt.rx + 1) > session->pkt.total) {
netdev_info(priv->ndev, "%s: 0x%p: should have been completed\n",
__func__, session);
goto out_session_cancel;
}
se_skb = j1939_session_skb_get_by_offset(session, packet * 7);
if (!se_skb) {
netdev_warn(priv->ndev, "%s: 0x%p: no skb found\n", __func__,
session);
goto out_session_cancel;
}
se_skcb = j1939_skb_to_cb(se_skb);
offset = packet * 7 - se_skcb->offset;
nbytes = se_skb->len - offset;
if (nbytes > 7)
nbytes = 7;
if (nbytes <= 0 || (nbytes + 1) > skb->len) {
netdev_info(priv->ndev, "%s: 0x%p: nbytes %i, len %i\n",
__func__, session, nbytes, skb->len);
goto out_session_cancel;
}
tpdat = se_skb->data;
if (!session->transmission) {
memcpy(&tpdat[offset], &dat[1], nbytes);
} else {
int err;
err = memcmp(&tpdat[offset], &dat[1], nbytes);
if (err)
netdev_err_once(priv->ndev,
"%s: 0x%p: Data of RX-looped back packet (%*ph) doesn't match TX data (%*ph)!\n",
__func__, session,
nbytes, &dat[1],
nbytes, &tpdat[offset]);
}
if (packet == session->pkt.rx)
session->pkt.rx++;
if (se_skcb->addr.type != J1939_ETP &&
j1939_cb_is_broadcast(&session->skcb)) {
if (session->pkt.rx >= session->pkt.total)
final = true;
else
remain = true;
} else {
/* never final, an EOMA must follow */
if (session->pkt.rx >= session->pkt.last)
do_cts_eoma = true;
}
if (final) {
j1939_session_timers_cancel(session);
j1939_session_completed(session);
} else if (remain) {
if (!session->transmission)
j1939_tp_set_rxtimeout(session, 750);
} else if (do_cts_eoma) {
j1939_tp_set_rxtimeout(session, 1250);
if (!session->transmission)
j1939_tp_schedule_txtimer(session, 0);
} else {
j1939_tp_set_rxtimeout(session, 750);
}
session->last_cmd = 0xff;
consume_skb(se_skb);
j1939_session_put(session);
return;
out_session_cancel:
kfree_skb(se_skb);
j1939_session_timers_cancel(session);
j1939_session_cancel(session, abort);
j1939_session_put(session);
}
static void j1939_xtp_rx_dat(struct j1939_priv *priv, struct sk_buff *skb)
{
struct j1939_sk_buff_cb *skcb;
struct j1939_session *session;
skcb = j1939_skb_to_cb(skb);
if (j1939_tp_im_transmitter(skcb)) {
session = j1939_session_get_by_addr(priv, &skcb->addr, false,
true);
if (!session)
netdev_info(priv->ndev, "%s: no tx connection found\n",
__func__);
else
j1939_xtp_rx_dat_one(session, skb);
}
if (j1939_tp_im_receiver(skcb)) {
session = j1939_session_get_by_addr(priv, &skcb->addr, false,
false);
if (!session)
netdev_info(priv->ndev, "%s: no rx connection found\n",
__func__);
else
j1939_xtp_rx_dat_one(session, skb);
}
if (j1939_cb_is_broadcast(skcb)) {
session = j1939_session_get_by_addr(priv, &skcb->addr, false,
false);
if (session)
j1939_xtp_rx_dat_one(session, skb);
}
}
/* j1939 main intf */
struct j1939_session *j1939_tp_send(struct j1939_priv *priv,
struct sk_buff *skb, size_t size)
{
struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
struct j1939_session *session;
int ret;
if (skcb->addr.pgn == J1939_TP_PGN_DAT ||
skcb->addr.pgn == J1939_TP_PGN_CTL ||
skcb->addr.pgn == J1939_ETP_PGN_DAT ||
skcb->addr.pgn == J1939_ETP_PGN_CTL)
/* avoid conflict */
return ERR_PTR(-EDOM);
if (size > priv->tp_max_packet_size)
return ERR_PTR(-EMSGSIZE);
if (size <= 8)
skcb->addr.type = J1939_SIMPLE;
else if (size > J1939_MAX_TP_PACKET_SIZE)
skcb->addr.type = J1939_ETP;
else
skcb->addr.type = J1939_TP;
if (skcb->addr.type == J1939_ETP &&
j1939_cb_is_broadcast(skcb))
return ERR_PTR(-EDESTADDRREQ);
/* fill in addresses from names */
ret = j1939_ac_fixup(priv, skb);
if (unlikely(ret))
return ERR_PTR(ret);
/* fix DST flags, it may be used there soon */
if (j1939_address_is_unicast(skcb->addr.da) &&
priv->ents[skcb->addr.da].nusers)
skcb->flags |= J1939_ECU_LOCAL_DST;
/* src is always local, I'm sending ... */
skcb->flags |= J1939_ECU_LOCAL_SRC;
/* prepare new session */
session = j1939_session_new(priv, skb, size);
if (!session)
return ERR_PTR(-ENOMEM);
/* skb is recounted in j1939_session_new() */
sock_hold(skb->sk);
session->sk = skb->sk;
session->transmission = true;
session->pkt.total = (size + 6) / 7;
session->pkt.block = skcb->addr.type == J1939_ETP ? 255 :
min(j1939_tp_block ?: 255, session->pkt.total);
if (j1939_cb_is_broadcast(&session->skcb))
/* set the end-packet for broadcast */
session->pkt.last = session->pkt.total;
skcb->tskey = atomic_inc_return(&session->sk->sk_tskey) - 1;
session->tskey = skcb->tskey;
return session;
}
static void j1939_tp_cmd_recv(struct j1939_priv *priv, struct sk_buff *skb)
{
struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
int extd = J1939_TP;
u8 cmd = skb->data[0];
switch (cmd) {
case J1939_ETP_CMD_RTS:
extd = J1939_ETP;
fallthrough;
case J1939_TP_CMD_BAM:
if (cmd == J1939_TP_CMD_BAM && !j1939_cb_is_broadcast(skcb)) {
netdev_err_once(priv->ndev, "%s: BAM to unicast (%02x), ignoring!\n",
__func__, skcb->addr.sa);
return;
}
fallthrough;
case J1939_TP_CMD_RTS:
if (skcb->addr.type != extd)
return;
if (cmd == J1939_TP_CMD_RTS && j1939_cb_is_broadcast(skcb)) {
netdev_alert(priv->ndev, "%s: rts without destination (%02x)\n",
__func__, skcb->addr.sa);
return;
}
if (j1939_tp_im_transmitter(skcb))
j1939_xtp_rx_rts(priv, skb, true);
if (j1939_tp_im_receiver(skcb) || j1939_cb_is_broadcast(skcb))
j1939_xtp_rx_rts(priv, skb, false);
break;
case J1939_ETP_CMD_CTS:
extd = J1939_ETP;
fallthrough;
case J1939_TP_CMD_CTS:
if (skcb->addr.type != extd)
return;
if (j1939_tp_im_transmitter(skcb))
j1939_xtp_rx_cts(priv, skb, false);
if (j1939_tp_im_receiver(skcb))
j1939_xtp_rx_cts(priv, skb, true);
break;
case J1939_ETP_CMD_DPO:
if (skcb->addr.type != J1939_ETP)
return;
if (j1939_tp_im_transmitter(skcb))
j1939_xtp_rx_dpo(priv, skb, true);
if (j1939_tp_im_receiver(skcb))
j1939_xtp_rx_dpo(priv, skb, false);
break;
case J1939_ETP_CMD_EOMA:
extd = J1939_ETP;
fallthrough;
case J1939_TP_CMD_EOMA:
if (skcb->addr.type != extd)
return;
if (j1939_tp_im_transmitter(skcb))
j1939_xtp_rx_eoma(priv, skb, false);
if (j1939_tp_im_receiver(skcb))
j1939_xtp_rx_eoma(priv, skb, true);
break;
case J1939_ETP_CMD_ABORT: /* && J1939_TP_CMD_ABORT */
if (j1939_cb_is_broadcast(skcb)) {
netdev_err_once(priv->ndev, "%s: abort to broadcast (%02x), ignoring!\n",
__func__, skcb->addr.sa);
return;
}
if (j1939_tp_im_transmitter(skcb))
j1939_xtp_rx_abort(priv, skb, true);
if (j1939_tp_im_receiver(skcb))
j1939_xtp_rx_abort(priv, skb, false);
break;
default:
return;
}
}
int j1939_tp_recv(struct j1939_priv *priv, struct sk_buff *skb)
{
struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
if (!j1939_tp_im_involved_anydir(skcb) && !j1939_cb_is_broadcast(skcb))
return 0;
switch (skcb->addr.pgn) {
case J1939_ETP_PGN_DAT:
skcb->addr.type = J1939_ETP;
fallthrough;
case J1939_TP_PGN_DAT:
j1939_xtp_rx_dat(priv, skb);
break;
case J1939_ETP_PGN_CTL:
skcb->addr.type = J1939_ETP;
fallthrough;
case J1939_TP_PGN_CTL:
if (skb->len < 8)
return 0; /* Don't care. Nothing to extract here */
j1939_tp_cmd_recv(priv, skb);
break;
default:
return 0; /* no problem */
}
return 1; /* "I processed the message" */
}
void j1939_simple_recv(struct j1939_priv *priv, struct sk_buff *skb)
{
struct j1939_session *session;
if (!skb->sk)
return;
if (skb->sk->sk_family != AF_CAN ||
skb->sk->sk_protocol != CAN_J1939)
return;
j1939_session_list_lock(priv);
session = j1939_session_get_simple(priv, skb);
j1939_session_list_unlock(priv);
if (!session) {
netdev_warn(priv->ndev,
"%s: Received already invalidated message\n",
__func__);
return;
}
j1939_session_timers_cancel(session);
j1939_session_deactivate(session);
j1939_session_put(session);
}
int j1939_cancel_active_session(struct j1939_priv *priv, struct sock *sk)
{
struct j1939_session *session, *saved;
netdev_dbg(priv->ndev, "%s, sk: %p\n", __func__, sk);
j1939_session_list_lock(priv);
list_for_each_entry_safe(session, saved,
&priv->active_session_list,
active_session_list_entry) {
if (!sk || sk == session->sk) {
if (hrtimer_try_to_cancel(&session->txtimer) == 1)
j1939_session_put(session);
if (hrtimer_try_to_cancel(&session->rxtimer) == 1)
j1939_session_put(session);
session->err = ESHUTDOWN;
j1939_session_deactivate_locked(session);
}
}
j1939_session_list_unlock(priv);
return NOTIFY_DONE;
}
void j1939_tp_init(struct j1939_priv *priv)
{
spin_lock_init(&priv->active_session_list_lock);
INIT_LIST_HEAD(&priv->active_session_list);
priv->tp_max_packet_size = J1939_MAX_ETP_PACKET_SIZE;
}
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