diff options
Diffstat (limited to 'net/can/j1939/transport.c')
| -rw-r--r-- | net/can/j1939/transport.c | 2206 |
1 files changed, 2206 insertions, 0 deletions
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c new file mode 100644 index 0000000000..fe3df23a25 --- /dev/null +++ b/net/can/j1939/transport.c @@ -0,0 +1,2206 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2010-2011 EIA Electronics, +// Kurt Van Dijck <kurt.van.dijck@eia.be> +// Copyright (c) 2018 Protonic, +// Robin van der Gracht <robin@protonic.nl> +// Copyright (c) 2017-2019 Pengutronix, +// Marc Kleine-Budde <kernel@pengutronix.de> +// Copyright (c) 2017-2019 Pengutronix, +// Oleksij Rempel <kernel@pengutronix.de> + +#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_all_active_sessions(). So handle this as an + * error, but let j1939_cancel_all_active_sessions() 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; + pgn_t pgn; + int len; + + 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); + + WARN_ON_ONCE(j1939_session_activate(session)); + + 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); + + 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; +} |