CAN Transport Protocols offer support for segmented Point-to-Point
communication between CAN nodes via two defined CAN Identifiers.
As CAN frames can only transport a small amount of data bytes
(max. 8 bytes for 'classic' CAN and max. 64 bytes for CAN FD) this
segmentation is needed to transport longer PDUs as needed e.g. for
vehicle diagnosis (UDS, ISO 14229) or IP-over-CAN traffic.
This protocol driver implements data transfers according to
ISO 15765-2:2016 for 'classic' CAN and CAN FD frame types.
Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
---
MAINTAINERS | 1 +
include/uapi/linux/can/isotp.h | 166 ++++
net/can/Kconfig | 13 +
net/can/Makefile | 3 +
net/can/isotp.c | 1428 ++++++++++++++++++++++++++++++++
5 files changed, 1611 insertions(+)
create mode 100644 include/uapi/linux/can/isotp.h
create mode 100644 net/can/isotp.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 190c7fa2ea01..92a0f6388f18 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3912,6 +3912,7 @@ F: include/net/netns/can.h
F: include/uapi/linux/can.h
F: include/uapi/linux/can/bcm.h
F: include/uapi/linux/can/gw.h
+F: include/uapi/linux/can/isotp.h
F: include/uapi/linux/can/raw.h
F: net/can/
diff --git a/include/uapi/linux/can/isotp.h b/include/uapi/linux/can/isotp.h
new file mode 100644
index 000000000000..553006509f4e
--- /dev/null
+++ b/include/uapi/linux/can/isotp.h
@@ -0,0 +1,166 @@
+/* SPDX-License-Identifier: ((GPL-2.0-only WITH Linux-syscall-note) OR BSD-3-Clause) */
+/*
+ * linux/can/isotp.h
+ *
+ * Definitions for isotp CAN sockets (ISO 15765-2:2016)
+ *
+ * Copyright (c) 2020 Volkswagen Group Electronic Research
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Volkswagen nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ */
+
+#ifndef _UAPI_CAN_ISOTP_H
+#define _UAPI_CAN_ISOTP_H
+
+#include <linux/types.h>
+#include <linux/can.h>
+
+#define SOL_CAN_ISOTP (SOL_CAN_BASE + CAN_ISOTP)
+
+/* for socket options affecting the socket (not the global system) */
+
+#define CAN_ISOTP_OPTS 1 /* pass struct can_isotp_options */
+
+#define CAN_ISOTP_RECV_FC 2 /* pass struct can_isotp_fc_options */
+
+/* sockopts to force stmin timer values for protocol regression tests */
+
+#define CAN_ISOTP_TX_STMIN 3 /* pass __u32 value in nano secs */
+ /* use this time instead of value */
+ /* provided in FC from the receiver */
+
+#define CAN_ISOTP_RX_STMIN 4 /* pass __u32 value in nano secs */
+ /* ignore received CF frames which */
+ /* timestamps differ less than val */
+
+#define CAN_ISOTP_LL_OPTS 5 /* pass struct can_isotp_ll_options */
+
+struct can_isotp_options {
+
+ __u32 flags; /* set flags for isotp behaviour. */
+ /* __u32 value : flags see below */
+
+ __u32 frame_txtime; /* frame transmission time (N_As/N_Ar) */
+ /* __u32 value : time in nano secs */
+
+ __u8 ext_address; /* set address for extended addressing */
+ /* __u8 value : extended address */
+
+ __u8 txpad_content; /* set content of padding byte (tx) */
+ /* __u8 value : content on tx path */
+
+ __u8 rxpad_content; /* set content of padding byte (rx) */
+ /* __u8 value : content on rx path */
+
+ __u8 rx_ext_address; /* set address for extended addressing */
+ /* __u8 value : extended address (rx) */
+};
+
+struct can_isotp_fc_options {
+
+ __u8 bs; /* blocksize provided in FC frame */
+ /* __u8 value : blocksize. 0 = off */
+
+ __u8 stmin; /* separation time provided in FC frame */
+ /* __u8 value : */
+ /* 0x00 - 0x7F : 0 - 127 ms */
+ /* 0x80 - 0xF0 : reserved */
+ /* 0xF1 - 0xF9 : 100 us - 900 us */
+ /* 0xFA - 0xFF : reserved */
+
+ __u8 wftmax; /* max. number of wait frame transmiss. */
+ /* __u8 value : 0 = omit FC N_PDU WT */
+};
+
+struct can_isotp_ll_options {
+
+ __u8 mtu; /* generated & accepted CAN frame type */
+ /* __u8 value : */
+ /* CAN_MTU (16) -> standard CAN 2.0 */
+ /* CANFD_MTU (72) -> CAN FD frame */
+
+ __u8 tx_dl; /* tx link layer data length in bytes */
+ /* (configured maximum payload length) */
+ /* __u8 value : 8,12,16,20,24,32,48,64 */
+ /* => rx path supports all LL_DL values */
+
+ __u8 tx_flags; /* set into struct canfd_frame.flags */
+ /* at frame creation: e.g. CANFD_BRS */
+ /* Obsolete when the BRS flag is fixed */
+ /* by the CAN netdriver configuration */
+};
+
+/* flags for isotp behaviour */
+
+#define CAN_ISOTP_LISTEN_MODE 0x001 /* listen only (do not send FC) */
+#define CAN_ISOTP_EXTEND_ADDR 0x002 /* enable extended addressing */
+#define CAN_ISOTP_TX_PADDING 0x004 /* enable CAN frame padding tx path */
+#define CAN_ISOTP_RX_PADDING 0x008 /* enable CAN frame padding rx path */
+#define CAN_ISOTP_CHK_PAD_LEN 0x010 /* check received CAN frame padding */
+#define CAN_ISOTP_CHK_PAD_DATA 0x020 /* check received CAN frame padding */
+#define CAN_ISOTP_HALF_DUPLEX 0x040 /* half duplex error state handling */
+#define CAN_ISOTP_FORCE_TXSTMIN 0x080 /* ignore stmin from received FC */
+#define CAN_ISOTP_FORCE_RXSTMIN 0x100 /* ignore CFs depending on rx stmin */
+#define CAN_ISOTP_RX_EXT_ADDR 0x200 /* different rx extended addressing */
+#define CAN_ISOTP_WAIT_TX_DONE 0x400 /* wait for tx completion */
+
+
+/* default values */
+
+#define CAN_ISOTP_DEFAULT_FLAGS 0
+#define CAN_ISOTP_DEFAULT_EXT_ADDRESS 0x00
+#define CAN_ISOTP_DEFAULT_PAD_CONTENT 0xCC /* prevent bit-stuffing */
+#define CAN_ISOTP_DEFAULT_FRAME_TXTIME 0
+#define CAN_ISOTP_DEFAULT_RECV_BS 0
+#define CAN_ISOTP_DEFAULT_RECV_STMIN 0x00
+#define CAN_ISOTP_DEFAULT_RECV_WFTMAX 0
+
+#define CAN_ISOTP_DEFAULT_LL_MTU CAN_MTU
+#define CAN_ISOTP_DEFAULT_LL_TX_DL CAN_MAX_DLEN
+#define CAN_ISOTP_DEFAULT_LL_TX_FLAGS 0
+
+/*
+ * Remark on CAN_ISOTP_DEFAULT_RECV_* values:
+ *
+ * We can strongly assume, that the Linux Kernel implementation of
+ * CAN_ISOTP is capable to run with BS=0, STmin=0 and WFTmax=0.
+ * But as we like to be able to behave as a commonly available ECU,
+ * these default settings can be changed via sockopts.
+ * For that reason the STmin value is intentionally _not_ checked for
+ * consistency and copied directly into the flow control (FC) frame.
+ *
+ */
+
+#endif /* !_UAPI_CAN_ISOTP_H */
diff --git a/net/can/Kconfig b/net/can/Kconfig
index 25436a715db3..021fe03a8ed6 100644
--- a/net/can/Kconfig
+++ b/net/can/Kconfig
@@ -55,6 +55,19 @@ config CAN_GW
source "net/can/j1939/Kconfig"
+config CAN_ISOTP
+ tristate "ISO 15765-2:2016 CAN transport protocol"
+ default y
+ help
+ CAN Transport Protocols offer support for segmented Point-to-Point
+ communication between CAN nodes via two defined CAN Identifiers.
+ As CAN frames can only transport a small amount of data bytes
+ (max. 8 bytes for 'classic' CAN and max. 64 bytes for CAN FD) this
+ segmentation is needed to transport longer PDUs as needed e.g. for
+ vehicle diagnosis (UDS, ISO 14229) or IP-over-CAN traffic.
+ This protocol driver implements data transfers according to
+ ISO 15765-2:2016 for 'classic' CAN and CAN FD frame types.
+
source "drivers/net/can/Kconfig"
endif
diff --git a/net/can/Makefile b/net/can/Makefile
index 08bd217fc051..58f2c31c1ef3 100644
--- a/net/can/Makefile
+++ b/net/can/Makefile
@@ -17,3 +17,6 @@ obj-$(CONFIG_CAN_GW) += can-gw.o
can-gw-y := gw.o
obj-$(CONFIG_CAN_J1939) += j1939/
+
+obj-$(CONFIG_CAN_ISOTP) += can-isotp.o
+can-isotp-y := isotp.o
diff --git a/net/can/isotp.c b/net/can/isotp.c
new file mode 100644
index 000000000000..efed3e47b6ee
--- /dev/null
+++ b/net/can/isotp.c
@@ -0,0 +1,1428 @@
+// SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
+/* isotp.c - ISO 15765-2 CAN transport protocol for protocol family CAN
+ *
+ * This implementation does not provide ISO-TP specific return values to the
+ * userspace.
+ *
+ * - RX path timeout of data reception leads to -ETIMEDOUT
+ * - RX path SN mismatch leads to -EILSEQ
+ * - RX path data reception with wrong padding leads to -EBADMSG
+ * - TX path flowcontrol reception timeout leads to -ECOMM
+ * - TX path flowcontrol reception overflow leads to -EMSGSIZE
+ * - TX path flowcontrol reception with wrong layout/padding leads to -EBADMSG
+ * - when a transfer (tx) is on the run the next write() blocks until it's done
+ * - use CAN_ISOTP_WAIT_TX_DONE flag to block the caller until the PDU is sent
+ * - as we have static buffers the check whether the PDU fits into the buffer
+ * is done at FF reception time (no support for sending 'wait frames')
+ * - take care of the tx-queue-len as traffic shaping is still on the TODO list
+ *
+ * Copyright (c) 2020 Volkswagen Group Electronic Research
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Volkswagen nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/hrtimer.h>
+#include <linux/wait.h>
+#include <linux/uio.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/socket.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <linux/can.h>
+#include <linux/can/core.h>
+#include <linux/can/skb.h>
+#include <linux/can/isotp.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <net/net_namespace.h>
+
+#define CAN_ISOTP_VERSION "20200928"
+
+MODULE_DESCRIPTION("PF_CAN isotp 15765-2:2016 protocol");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Oliver Hartkopp <socketcan@xxxxxxxxxxxx>");
+MODULE_ALIAS("can-proto-6");
+
+#define SINGLE_MASK(id) ((id & CAN_EFF_FLAG) ? \
+ (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \
+ (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
+
+/* ISO 15765-2:2016 supports more than 4095 byte per ISO PDU as the FF_DL can
+ * take full 32 bit values (4 Gbyte). We would need some good concept to handle
+ * this between user space and kernel space. For now increase the static buffer
+ * to something about 8 kbyte to be able to test this new functionality.
+ */
+#define MAX_MSG_LENGTH 8200
+
+/* N_PCI type values in bits 7-4 of N_PCI bytes */
+#define N_PCI_SF 0x00 /* single frame */
+#define N_PCI_FF 0x10 /* first frame */
+#define N_PCI_CF 0x20 /* consecutive frame */
+#define N_PCI_FC 0x30 /* flow control */
+
+#define N_PCI_SZ 1 /* size of the PCI byte #1 */
+#define SF_PCI_SZ4 1 /* size of SingleFrame PCI including 4 bit SF_DL */
+#define SF_PCI_SZ8 2 /* size of SingleFrame PCI including 8 bit SF_DL */
+#define FF_PCI_SZ12 2 /* size of FirstFrame PCI including 12 bit FF_DL */
+#define FF_PCI_SZ32 6 /* size of FirstFrame PCI including 32 bit FF_DL */
+#define FC_CONTENT_SZ 3 /* flow control content size in byte (FS/BS/STmin) */
+
+#define ISOTP_CHECK_PADDING (CAN_ISOTP_CHK_PAD_LEN | CAN_ISOTP_CHK_PAD_DATA)
+
+/* Flow Status given in FC frame */
+#define ISOTP_FC_CTS 0 /* clear to send */
+#define ISOTP_FC_WT 1 /* wait */
+#define ISOTP_FC_OVFLW 2 /* overflow */
+
+enum {
+ ISOTP_IDLE = 0,
+ ISOTP_WAIT_FIRST_FC,
+ ISOTP_WAIT_FC,
+ ISOTP_WAIT_DATA,
+ ISOTP_SENDING
+};
+
+struct tpcon {
+ int idx;
+ int len;
+ u8 state;
+ u8 bs;
+ u8 sn;
+ u8 ll_dl;
+ u8 buf[MAX_MSG_LENGTH + 1];
+};
+
+struct isotp_sock {
+ struct sock sk;
+ int bound;
+ int ifindex;
+ canid_t txid;
+ canid_t rxid;
+ ktime_t tx_gap;
+ ktime_t lastrxcf_tstamp;
+ struct hrtimer rxtimer, txtimer;
+ struct can_isotp_options opt;
+ struct can_isotp_fc_options rxfc, txfc;
+ struct can_isotp_ll_options ll;
+ __u32 force_tx_stmin;
+ __u32 force_rx_stmin;
+ struct tpcon rx, tx;
+ struct notifier_block notifier;
+ wait_queue_head_t wait;
+};
+
+static inline struct isotp_sock *isotp_sk(const struct sock *sk)
+{
+ return (struct isotp_sock *)sk;
+}
+
+static enum hrtimer_restart isotp_rx_timer_handler(struct hrtimer *hrtimer)
+{
+ struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
+ rxtimer);
+ struct sock *sk = &so->sk;
+
+ if (so->rx.state == ISOTP_WAIT_DATA) {
+ /* we did not get new data frames in time */
+
+ /* report 'connection timed out' */
+ sk->sk_err = ETIMEDOUT;
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_error_report(sk);
+
+ /* reset rx state */
+ so->rx.state = ISOTP_IDLE;
+ }
+
+ return HRTIMER_NORESTART;
+}
+
+static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
+{
+ struct net_device *dev;
+ struct sk_buff *nskb;
+ struct canfd_frame *ncf;
+ struct isotp_sock *so = isotp_sk(sk);
+ int can_send_ret;
+
+ nskb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), gfp_any());
+ if (!nskb)
+ return 1;
+
+ dev = dev_get_by_index(sock_net(sk), so->ifindex);
+ if (!dev) {
+ kfree_skb(nskb);
+ return 1;
+ }
+
+ can_skb_reserve(nskb);
+ can_skb_prv(nskb)->ifindex = dev->ifindex;
+ can_skb_prv(nskb)->skbcnt = 0;
+
+ nskb->dev = dev;
+ can_skb_set_owner(nskb, sk);
+ ncf = (struct canfd_frame *)nskb->data;
+ skb_put(nskb, so->ll.mtu);
+
+ /* create & send flow control reply */
+ ncf->can_id = so->txid;
+
+ if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
+ memset(ncf->data, so->opt.txpad_content, CAN_MAX_DLEN);
+ ncf->len = CAN_MAX_DLEN;
+ } else {
+ ncf->len = ae + FC_CONTENT_SZ;
+ }
+
+ ncf->data[ae] = N_PCI_FC | flowstatus;
+ ncf->data[ae + 1] = so->rxfc.bs;
+ ncf->data[ae + 2] = so->rxfc.stmin;
+
+ if (ae)
+ ncf->data[0] = so->opt.ext_address;
+
+ if (so->ll.mtu == CANFD_MTU)
+ ncf->flags = so->ll.tx_flags;
+
+ can_send_ret = can_send(nskb, 1);
+ if (can_send_ret)
+ printk_once(KERN_NOTICE "can-isotp: %s: can_send_ret %d\n",
+ __func__, can_send_ret);
+
+ dev_put(dev);
+
+ /* reset blocksize counter */
+ so->rx.bs = 0;
+
+ /* reset last CF frame rx timestamp for rx stmin enforcement */
+ so->lastrxcf_tstamp = ktime_set(0, 0);
+
+ /* start rx timeout watchdog */
+ hrtimer_start(&so->rxtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
+ return 0;
+}
+
+static void isotp_rcv_skb(struct sk_buff *skb, struct sock *sk)
+{
+ struct sockaddr_can *addr = (struct sockaddr_can *)skb->cb;
+
+ BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct sockaddr_can));
+
+ memset(addr, 0, sizeof(*addr));
+ addr->can_family = AF_CAN;
+ addr->can_ifindex = skb->dev->ifindex;
+
+ if (sock_queue_rcv_skb(sk, skb) < 0)
+ kfree_skb(skb);
+}
+
+static u8 padlen(u8 datalen)
+{
+ const u8 plen[] = {8, 8, 8, 8, 8, 8, 8, 8, 8, /* 0 - 8 */
+ 12, 12, 12, 12, /* 9 - 12 */
+ 16, 16, 16, 16, /* 13 - 16 */
+ 20, 20, 20, 20, /* 17 - 20 */
+ 24, 24, 24, 24, /* 21 - 24 */
+ 32, 32, 32, 32, 32, 32, 32, 32, /* 25 - 32 */
+ 48, 48, 48, 48, 48, 48, 48, 48, /* 33 - 40 */
+ 48, 48, 48, 48, 48, 48, 48, 48}; /* 41 - 48 */
+
+ if (datalen > 48)
+ return 64;
+
+ return plen[datalen];
+}
+
+/* check for length optimization and return 1/true when the check fails */
+static int check_optimized(struct canfd_frame *cf, int start_index)
+{
+ /* for CAN_DL <= 8 the start_index is equal to the CAN_DL as the
+ * padding would start at this point. E.g. if the padding would
+ * start at cf.data[7] cf->len has to be 7 to be optimal.
+ * Note: The data[] index starts with zero.
+ */
+ if (cf->len <= CAN_MAX_DLEN)
+ return (cf->len != start_index);
+
+ /* This relation is also valid in the non-linear DLC range, where
+ * we need to take care of the minimal next possible CAN_DL.
+ * The correct check would be (padlen(cf->len) != padlen(start_index)).
+ * But as cf->len can only take discrete values from 12, .., 64 at this
+ * point the padlen(cf->len) is always equal to cf->len.
+ */
+ return (cf->len != padlen(start_index));
+}
+
+/* check padding and return 1/true when the check fails */
+static int check_pad(struct isotp_sock *so, struct canfd_frame *cf,
+ int start_index, __u8 content)
+{
+ int i;
+
+ /* no RX_PADDING value => check length of optimized frame length */
+ if (!(so->opt.flags & CAN_ISOTP_RX_PADDING)) {
+ if (so->opt.flags & CAN_ISOTP_CHK_PAD_LEN)
+ return check_optimized(cf, start_index);
+
+ /* no valid test against empty value => ignore frame */
+ return 1;
+ }
+
+ /* check datalength of correctly padded CAN frame */
+ if ((so->opt.flags & CAN_ISOTP_CHK_PAD_LEN) &&
+ cf->len != padlen(cf->len))
+ return 1;
+
+ /* check padding content */
+ if (so->opt.flags & CAN_ISOTP_CHK_PAD_DATA) {
+ for (i = start_index; i < cf->len; i++)
+ if (cf->data[i] != content)
+ return 1;
+ }
+ return 0;
+}
+
+static int isotp_rcv_fc(struct isotp_sock *so, struct canfd_frame *cf, int ae)
+{
+ struct sock *sk = &so->sk;
+
+ if (so->tx.state != ISOTP_WAIT_FC &&
+ so->tx.state != ISOTP_WAIT_FIRST_FC)
+ return 0;
+
+ hrtimer_cancel(&so->txtimer);
+
+ if ((cf->len < ae + FC_CONTENT_SZ) ||
+ ((so->opt.flags & ISOTP_CHECK_PADDING) &&
+ check_pad(so, cf, ae + FC_CONTENT_SZ, so->opt.rxpad_content))) {
+ /* malformed PDU - report 'not a data message' */
+ sk->sk_err = EBADMSG;
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_error_report(sk);
+
+ so->tx.state = ISOTP_IDLE;
+ wake_up_interruptible(&so->wait);
+ return 1;
+ }
+
+ /* get communication parameters only from the first FC frame */
+ if (so->tx.state == ISOTP_WAIT_FIRST_FC) {
+ so->txfc.bs = cf->data[ae + 1];
+ so->txfc.stmin = cf->data[ae + 2];
+
+ /* fix wrong STmin values according spec */
+ if (so->txfc.stmin > 0x7F &&
+ (so->txfc.stmin < 0xF1 || so->txfc.stmin > 0xF9))
+ so->txfc.stmin = 0x7F;
+
+ so->tx_gap = ktime_set(0, 0);
+ /* add transmission time for CAN frame N_As */
+ so->tx_gap = ktime_add_ns(so->tx_gap, so->opt.frame_txtime);
+ /* add waiting time for consecutive frames N_Cs */
+ if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
+ so->tx_gap = ktime_add_ns(so->tx_gap,
+ so->force_tx_stmin);
+ else if (so->txfc.stmin < 0x80)
+ so->tx_gap = ktime_add_ns(so->tx_gap,
+ so->txfc.stmin * 1000000);
+ else
+ so->tx_gap = ktime_add_ns(so->tx_gap,
+ (so->txfc.stmin - 0xF0)
+ * 100000);
+ so->tx.state = ISOTP_WAIT_FC;
+ }
+
+ switch (cf->data[ae] & 0x0F) {
+ case ISOTP_FC_CTS:
+ so->tx.bs = 0;
+ so->tx.state = ISOTP_SENDING;
+ /* start cyclic timer for sending CF frame */
+ hrtimer_start(&so->txtimer, so->tx_gap,
+ HRTIMER_MODE_REL_SOFT);
+ break;
+
+ case ISOTP_FC_WT:
+ /* start timer to wait for next FC frame */
+ hrtimer_start(&so->txtimer, ktime_set(1, 0),
+ HRTIMER_MODE_REL_SOFT);
+ break;
+
+ case ISOTP_FC_OVFLW:
+ /* overflow on receiver side - report 'message too long' */
+ sk->sk_err = EMSGSIZE;
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_error_report(sk);
+ fallthrough;
+
+ default:
+ /* stop this tx job */
+ so->tx.state = ISOTP_IDLE;
+ wake_up_interruptible(&so->wait);
+ }
+ return 0;
+}
+
+static int isotp_rcv_sf(struct sock *sk, struct canfd_frame *cf, int pcilen,
+ struct sk_buff *skb, int len)
+{
+ struct isotp_sock *so = isotp_sk(sk);
+ struct sk_buff *nskb;
+
+ hrtimer_cancel(&so->rxtimer);
+ so->rx.state = ISOTP_IDLE;
+
+ if (!len || len > cf->len - pcilen)
+ return 1;
+
+ if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
+ check_pad(so, cf, pcilen + len, so->opt.rxpad_content)) {
+ /* malformed PDU - report 'not a data message' */
+ sk->sk_err = EBADMSG;
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_error_report(sk);
+ return 1;
+ }
+
+ nskb = alloc_skb(len, gfp_any());
+ if (!nskb)
+ return 1;
+
+ memcpy(skb_put(nskb, len), &cf->data[pcilen], len);
+
+ nskb->tstamp = skb->tstamp;
+ nskb->dev = skb->dev;
+ isotp_rcv_skb(nskb, sk);
+ return 0;
+}
+
+static int isotp_rcv_ff(struct sock *sk, struct canfd_frame *cf, int ae)
+{
+ struct isotp_sock *so = isotp_sk(sk);
+ int i;
+ int off;
+ int ff_pci_sz;
+
+ hrtimer_cancel(&so->rxtimer);
+ so->rx.state = ISOTP_IDLE;
+
+ /* get the used sender LL_DL from the (first) CAN frame data length */
+ so->rx.ll_dl = padlen(cf->len);
+
+ /* the first frame has to use the entire frame up to LL_DL length */
+ if (cf->len != so->rx.ll_dl)
+ return 1;
+
+ /* get the FF_DL */
+ so->rx.len = (cf->data[ae] & 0x0F) << 8;
+ so->rx.len += cf->data[ae + 1];
+
+ /* Check for FF_DL escape sequence supporting 32 bit PDU length */
+ if (so->rx.len) {
+ ff_pci_sz = FF_PCI_SZ12;
+ } else {
+ /* FF_DL = 0 => get real length from next 4 bytes */
+ so->rx.len = cf->data[ae + 2] << 24;
+ so->rx.len += cf->data[ae + 3] << 16;
+ so->rx.len += cf->data[ae + 4] << 8;
+ so->rx.len += cf->data[ae + 5];
+ ff_pci_sz = FF_PCI_SZ32;
+ }
+
+ /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
+ off = (so->rx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
+
+ if (so->rx.len + ae + off + ff_pci_sz < so->rx.ll_dl)
+ return 1;
+
+ if (so->rx.len > MAX_MSG_LENGTH) {
+ /* send FC frame with overflow status */
+ isotp_send_fc(sk, ae, ISOTP_FC_OVFLW);
+ return 1;
+ }
+
+ /* copy the first received data bytes */
+ so->rx.idx = 0;
+ for (i = ae + ff_pci_sz; i < so->rx.ll_dl; i++)
+ so->rx.buf[so->rx.idx++] = cf->data[i];
+
+ /* initial setup for this pdu receiption */
+ so->rx.sn = 1;
+ so->rx.state = ISOTP_WAIT_DATA;
+
+ /* no creation of flow control frames */
+ if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
+ return 0;
+
+ /* send our first FC frame */
+ isotp_send_fc(sk, ae, ISOTP_FC_CTS);
+ return 0;
+}
+
+static int isotp_rcv_cf(struct sock *sk, struct canfd_frame *cf, int ae,
+ struct sk_buff *skb)
+{
+ struct isotp_sock *so = isotp_sk(sk);
+ struct sk_buff *nskb;
+ int i;
+
+ if (so->rx.state != ISOTP_WAIT_DATA)
+ return 0;
+
+ /* drop if timestamp gap is less than force_rx_stmin nano secs */
+ if (so->opt.flags & CAN_ISOTP_FORCE_RXSTMIN) {
+ if (ktime_to_ns(ktime_sub(skb->tstamp, so->lastrxcf_tstamp)) <
+ so->force_rx_stmin)
+ return 0;
+
+ so->lastrxcf_tstamp = skb->tstamp;
+ }
+
+ hrtimer_cancel(&so->rxtimer);
+
+ /* CFs are never longer than the FF */
+ if (cf->len > so->rx.ll_dl)
+ return 1;
+
+ /* CFs have usually the LL_DL length */
+ if (cf->len < so->rx.ll_dl) {
+ /* this is only allowed for the last CF */
+ if (so->rx.len - so->rx.idx > so->rx.ll_dl - ae - N_PCI_SZ)
+ return 1;
+ }
+
+ if ((cf->data[ae] & 0x0F) != so->rx.sn) {
+ /* wrong sn detected - report 'illegal byte sequence' */
+ sk->sk_err = EILSEQ;
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_error_report(sk);
+
+ /* reset rx state */
+ so->rx.state = ISOTP_IDLE;
+ return 1;
+ }
+ so->rx.sn++;
+ so->rx.sn %= 16;
+
+ for (i = ae + N_PCI_SZ; i < cf->len; i++) {
+ so->rx.buf[so->rx.idx++] = cf->data[i];
+ if (so->rx.idx >= so->rx.len)
+ break;
+ }
+
+ if (so->rx.idx >= so->rx.len) {
+ /* we are done */
+ so->rx.state = ISOTP_IDLE;
+
+ if ((so->opt.flags & ISOTP_CHECK_PADDING) &&
+ check_pad(so, cf, i + 1, so->opt.rxpad_content)) {
+ /* malformed PDU - report 'not a data message' */
+ sk->sk_err = EBADMSG;
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_error_report(sk);
+ return 1;
+ }
+
+ nskb = alloc_skb(so->rx.len, gfp_any());
+ if (!nskb)
+ return 1;
+
+ memcpy(skb_put(nskb, so->rx.len), so->rx.buf,
+ so->rx.len);
+
+ nskb->tstamp = skb->tstamp;
+ nskb->dev = skb->dev;
+ isotp_rcv_skb(nskb, sk);
+ return 0;
+ }
+
+ /* no creation of flow control frames */
+ if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
+ return 0;
+
+ /* perform blocksize handling, if enabled */
+ if (!so->rxfc.bs || ++so->rx.bs < so->rxfc.bs) {
+ /* start rx timeout watchdog */
+ hrtimer_start(&so->rxtimer, ktime_set(1, 0),
+ HRTIMER_MODE_REL_SOFT);
+ return 0;
+ }
+
+ /* we reached the specified blocksize so->rxfc.bs */
+ isotp_send_fc(sk, ae, ISOTP_FC_CTS);
+ return 0;
+}
+
+static void isotp_rcv(struct sk_buff *skb, void *data)
+{
+ struct sock *sk = (struct sock *)data;
+ struct isotp_sock *so = isotp_sk(sk);
+ struct canfd_frame *cf;
+ int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
+ u8 n_pci_type, sf_dl;
+
+ /* Strictly receive only frames with the configured MTU size
+ * => clear separation of CAN2.0 / CAN FD transport channels
+ */
+ if (skb->len != so->ll.mtu)
+ return;
+
+ cf = (struct canfd_frame *)skb->data;
+
+ /* if enabled: check receiption of my configured extended address */
+ if (ae && cf->data[0] != so->opt.rx_ext_address)
+ return;
+
+ n_pci_type = cf->data[ae] & 0xF0;
+
+ if (so->opt.flags & CAN_ISOTP_HALF_DUPLEX) {
+ /* check rx/tx path half duplex expectations */
+ if ((so->tx.state != ISOTP_IDLE && n_pci_type != N_PCI_FC) ||
+ (so->rx.state != ISOTP_IDLE && n_pci_type == N_PCI_FC))
+ return;
+ }
+
+ switch (n_pci_type) {
+ case N_PCI_FC:
+ /* tx path: flow control frame containing the FC parameters */
+ isotp_rcv_fc(so, cf, ae);
+ break;
+
+ case N_PCI_SF:
+ /* rx path: single frame
+ *
+ * As we do not have a rx.ll_dl configuration, we can only test
+ * if the CAN frames payload length matches the LL_DL == 8
+ * requirements - no matter if it's CAN 2.0 or CAN FD
+ */
+
+ /* get the SF_DL from the N_PCI byte */
+ sf_dl = cf->data[ae] & 0x0F;
+
+ if (cf->len <= CAN_MAX_DLEN) {
+ isotp_rcv_sf(sk, cf, SF_PCI_SZ4 + ae, skb, sf_dl);
+ } else {
+ if (skb->len == CANFD_MTU) {
+ /* We have a CAN FD frame and CAN_DL is greater than 8:
+ * Only frames with the SF_DL == 0 ESC value are valid.
+ *
+ * If so take care of the increased SF PCI size
+ * (SF_PCI_SZ8) to point to the message content behind
+ * the extended SF PCI info and get the real SF_DL
+ * length value from the formerly first data byte.
+ */
+ if (sf_dl == 0)
+ isotp_rcv_sf(sk, cf, SF_PCI_SZ8 + ae, skb,
+ cf->data[SF_PCI_SZ4 + ae]);
+ }
+ }
+ break;
+
+ case N_PCI_FF:
+ /* rx path: first frame */
+ isotp_rcv_ff(sk, cf, ae);
+ break;
+
+ case N_PCI_CF:
+ /* rx path: consecutive frame */
+ isotp_rcv_cf(sk, cf, ae, skb);
+ break;
+ }
+}
+
+static void isotp_fill_dataframe(struct canfd_frame *cf, struct isotp_sock *so,
+ int ae, int off)
+{
+ int pcilen = N_PCI_SZ + ae + off;
+ int space = so->tx.ll_dl - pcilen;
+ int num = min_t(int, so->tx.len - so->tx.idx, space);
+ int i;
+
+ cf->can_id = so->txid;
+ cf->len = num + pcilen;
+
+ if (num < space) {
+ if (so->opt.flags & CAN_ISOTP_TX_PADDING) {
+ /* user requested padding */
+ cf->len = padlen(cf->len);
+ memset(cf->data, so->opt.txpad_content, cf->len);
+ } else if (cf->len > CAN_MAX_DLEN) {
+ /* mandatory padding for CAN FD frames */
+ cf->len = padlen(cf->len);
+ memset(cf->data, CAN_ISOTP_DEFAULT_PAD_CONTENT,
+ cf->len);
+ }
+ }
+
+ for (i = 0; i < num; i++)
+ cf->data[pcilen + i] = so->tx.buf[so->tx.idx++];
+
+ if (ae)
+ cf->data[0] = so->opt.ext_address;
+}
+
+static void isotp_create_fframe(struct canfd_frame *cf, struct isotp_sock *so,
+ int ae)
+{
+ int i;
+ int ff_pci_sz;
+
+ cf->can_id = so->txid;
+ cf->len = so->tx.ll_dl;
+ if (ae)
+ cf->data[0] = so->opt.ext_address;
+
+ /* create N_PCI bytes with 12/32 bit FF_DL data length */
+ if (so->tx.len > 4095) {
+ /* use 32 bit FF_DL notation */
+ cf->data[ae] = N_PCI_FF;
+ cf->data[ae + 1] = 0;
+ cf->data[ae + 2] = (u8)(so->tx.len >> 24) & 0xFFU;
+ cf->data[ae + 3] = (u8)(so->tx.len >> 16) & 0xFFU;
+ cf->data[ae + 4] = (u8)(so->tx.len >> 8) & 0xFFU;
+ cf->data[ae + 5] = (u8)so->tx.len & 0xFFU;
+ ff_pci_sz = FF_PCI_SZ32;
+ } else {
+ /* use 12 bit FF_DL notation */
+ cf->data[ae] = (u8)(so->tx.len >> 8) | N_PCI_FF;
+ cf->data[ae + 1] = (u8)so->tx.len & 0xFFU;
+ ff_pci_sz = FF_PCI_SZ12;
+ }
+
+ /* add first data bytes depending on ae */
+ for (i = ae + ff_pci_sz; i < so->tx.ll_dl; i++)
+ cf->data[i] = so->tx.buf[so->tx.idx++];
+
+ so->tx.sn = 1;
+ so->tx.state = ISOTP_WAIT_FIRST_FC;
+}
+
+static enum hrtimer_restart isotp_tx_timer_handler(struct hrtimer *hrtimer)
+{
+ struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
+ txtimer);
+ struct sock *sk = &so->sk;
+ struct sk_buff *skb;
+ struct net_device *dev;
+ struct canfd_frame *cf;
+ enum hrtimer_restart restart = HRTIMER_NORESTART;
+ int can_send_ret;
+ int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
+
+ switch (so->tx.state) {
+ case ISOTP_WAIT_FC:
+ case ISOTP_WAIT_FIRST_FC:
+
+ /* we did not get any flow control frame in time */
+
+ /* report 'communication error on send' */
+ sk->sk_err = ECOMM;
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_error_report(sk);
+
+ /* reset tx state */
+ so->tx.state = ISOTP_IDLE;
+ wake_up_interruptible(&so->wait);
+ break;
+
+ case ISOTP_SENDING:
+
+ /* push out the next segmented pdu */
+ dev = dev_get_by_index(sock_net(sk), so->ifindex);
+ if (!dev)
+ break;
+
+isotp_tx_burst:
+ skb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv),
+ gfp_any());
+ if (!skb) {
+ dev_put(dev);
+ break;
+ }
+
+ can_skb_reserve(skb);
+ can_skb_prv(skb)->ifindex = dev->ifindex;
+ can_skb_prv(skb)->skbcnt = 0;
+
+ cf = (struct canfd_frame *)skb->data;
+ skb_put(skb, so->ll.mtu);
+
+ /* create consecutive frame */
+ isotp_fill_dataframe(cf, so, ae, 0);
+
+ /* place consecutive frame N_PCI in appropriate index */
+ cf->data[ae] = N_PCI_CF | so->tx.sn++;
+ so->tx.sn %= 16;
+ so->tx.bs++;
+
+ if (so->ll.mtu == CANFD_MTU)
+ cf->flags = so->ll.tx_flags;
+
+ skb->dev = dev;
+ can_skb_set_owner(skb, sk);
+
+ can_send_ret = can_send(skb, 1);
+ if (can_send_ret)
+ printk_once(KERN_NOTICE "can-isotp: %s: can_send_ret %d\n",
+ __func__, can_send_ret);
+
+ if (so->tx.idx >= so->tx.len) {
+ /* we are done */
+ so->tx.state = ISOTP_IDLE;
+ dev_put(dev);
+ wake_up_interruptible(&so->wait);
+ break;
+ }
+
+ if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
+ /* stop and wait for FC */
+ so->tx.state = ISOTP_WAIT_FC;
+ dev_put(dev);
+ hrtimer_set_expires(&so->txtimer,
+ ktime_add(ktime_get(),
+ ktime_set(1, 0)));
+ restart = HRTIMER_RESTART;
+ break;
+ }
+
+ /* no gap between data frames needed => use burst mode */
+ if (!so->tx_gap)
+ goto isotp_tx_burst;
+
+ /* start timer to send next data frame with correct delay */
+ dev_put(dev);
+ hrtimer_set_expires(&so->txtimer,
+ ktime_add(ktime_get(), so->tx_gap));
+ restart = HRTIMER_RESTART;
+ break;
+
+ default:
+ WARN_ON_ONCE(1);
+ }
+
+ return restart;
+}
+
+static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
+{
+ struct sock *sk = sock->sk;
+ struct isotp_sock *so = isotp_sk(sk);
+ struct sk_buff *skb;
+ struct net_device *dev;
+ struct canfd_frame *cf;
+ int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
+ int wait_tx_done = (so->opt.flags & CAN_ISOTP_WAIT_TX_DONE) ? 1 : 0;
+ int off;
+ int err;
+
+ if (!so->bound)
+ return -EADDRNOTAVAIL;
+
+ /* we do not support multiple buffers - for now */
+ if (so->tx.state != ISOTP_IDLE || wq_has_sleeper(&so->wait)) {
+ if (msg->msg_flags & MSG_DONTWAIT)
+ return -EAGAIN;
+
+ /* wait for complete transmission of current pdu */
+ wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
+ }
+
+ if (!size || size > MAX_MSG_LENGTH)
+ return -EINVAL;
+
+ err = memcpy_from_msg(so->tx.buf, msg, size);
+ if (err < 0)
+ return err;
+
+ dev = dev_get_by_index(sock_net(sk), so->ifindex);
+ if (!dev)
+ return -ENXIO;
+
+ skb = sock_alloc_send_skb(sk, so->ll.mtu + sizeof(struct can_skb_priv),
+ msg->msg_flags & MSG_DONTWAIT, &err);
+ if (!skb) {
+ dev_put(dev);
+ return err;
+ }
+
+ can_skb_reserve(skb);
+ can_skb_prv(skb)->ifindex = dev->ifindex;
+ can_skb_prv(skb)->skbcnt = 0;
+
+ so->tx.state = ISOTP_SENDING;
+ so->tx.len = size;
+ so->tx.idx = 0;
+
+ cf = (struct canfd_frame *)skb->data;
+ skb_put(skb, so->ll.mtu);
+
+ /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
+ off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
+
+ /* check for single frame transmission depending on TX_DL */
+ if (size <= so->tx.ll_dl - SF_PCI_SZ4 - ae - off) {
+ /* The message size generally fits into a SingleFrame - good.
+ *
+ * SF_DL ESC offset optimization:
+ *
+ * When TX_DL is greater 8 but the message would still fit
+ * into a 8 byte CAN frame, we can omit the offset.
+ * This prevents a protocol caused length extension from
+ * CAN_DL = 8 to CAN_DL = 12 due to the SF_SL ESC handling.
+ */
+ if (size <= CAN_MAX_DLEN - SF_PCI_SZ4 - ae)
+ off = 0;
+
+ isotp_fill_dataframe(cf, so, ae, off);
+
+ /* place single frame N_PCI w/o length in appropriate index */
+ cf->data[ae] = N_PCI_SF;
+
+ /* place SF_DL size value depending on the SF_DL ESC offset */
+ if (off)
+ cf->data[SF_PCI_SZ4 + ae] = size;
+ else
+ cf->data[ae] |= size;
+
+ so->tx.state = ISOTP_IDLE;
+ wake_up_interruptible(&so->wait);
+
+ /* don't enable wait queue for a single frame transmission */
+ wait_tx_done = 0;
+ } else {
+ /* send first frame and wait for FC */
+
+ isotp_create_fframe(cf, so, ae);
+
+ /* start timeout for FC */
+ hrtimer_start(&so->txtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
+ }
+
+ /* send the first or only CAN frame */
+ if (so->ll.mtu == CANFD_MTU)
+ cf->flags = so->ll.tx_flags;
+
+ skb->dev = dev;
+ skb->sk = sk;
+ err = can_send(skb, 1);
+ dev_put(dev);
+ if (err) {
+ printk_once(KERN_NOTICE "can-isotp: %s: can_send_ret %d\n",
+ __func__, err);
+ return err;
+ }
+
+ if (wait_tx_done) {
+ /* wait for complete transmission of current pdu */
+ wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
+ }
+
+ return size;
+}
+
+static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
+ int flags)
+{
+ struct sock *sk = sock->sk;
+ struct sk_buff *skb;
+ int err = 0;
+ int noblock;
+
+ noblock = flags & MSG_DONTWAIT;
+ flags &= ~MSG_DONTWAIT;
+
+ skb = skb_recv_datagram(sk, flags, noblock, &err);
+ if (!skb)
+ return err;
+
+ if (size < skb->len)
+ msg->msg_flags |= MSG_TRUNC;
+ else
+ size = skb->len;
+
+ err = memcpy_to_msg(msg, skb->data, size);
+ if (err < 0) {
+ skb_free_datagram(sk, skb);
+ return err;
+ }
+
+ sock_recv_timestamp(msg, sk, skb);
+
+ if (msg->msg_name) {
+ msg->msg_namelen = sizeof(struct sockaddr_can);
+ memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
+ }
+
+ skb_free_datagram(sk, skb);
+
+ return size;
+}
+
+static int isotp_release(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct isotp_sock *so;
+ struct net *net;
+
+ if (!sk)
+ return 0;
+
+ so = isotp_sk(sk);
+ net = sock_net(sk);
+
+ /* wait for complete transmission of current pdu */
+ wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
+
+ unregister_netdevice_notifier(&so->notifier);
+
+ lock_sock(sk);
+
+ hrtimer_cancel(&so->txtimer);
+ hrtimer_cancel(&so->rxtimer);
+
+ /* remove current filters & unregister */
+ if (so->bound) {
+ if (so->ifindex) {
+ struct net_device *dev;
+
+ dev = dev_get_by_index(net, so->ifindex);
+ if (dev) {
+ can_rx_unregister(net, dev, so->rxid,
+ SINGLE_MASK(so->rxid),
+ isotp_rcv, sk);
+ dev_put(dev);
+ }
+ }
+ }
+
+ so->ifindex = 0;
+ so->bound = 0;
+
+ sock_orphan(sk);
+ sock->sk = NULL;
+
+ release_sock(sk);
+ sock_put(sk);
+
+ return 0;
+}
+
+static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
+{
+ struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+ struct sock *sk = sock->sk;
+ struct isotp_sock *so = isotp_sk(sk);
+ struct net *net = sock_net(sk);
+ int ifindex;
+ struct net_device *dev;
+ int err = 0;
+ int notify_enetdown = 0;
+
+ if (len < CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp))
+ return -EINVAL;
+
+ if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id)
+ return -EADDRNOTAVAIL;
+
+ if ((addr->can_addr.tp.rx_id | addr->can_addr.tp.tx_id) &
+ (CAN_ERR_FLAG | CAN_RTR_FLAG))
+ return -EADDRNOTAVAIL;
+
+ if (!addr->can_ifindex)
+ return -ENODEV;
+
+ lock_sock(sk);
+
+ if (so->bound && addr->can_ifindex == so->ifindex &&
+ addr->can_addr.tp.rx_id == so->rxid &&
+ addr->can_addr.tp.tx_id == so->txid)
+ goto out;
+
+ dev = dev_get_by_index(net, addr->can_ifindex);
+ if (!dev) {
+ err = -ENODEV;
+ goto out;
+ }
+ if (dev->type != ARPHRD_CAN) {
+ dev_put(dev);
+ err = -ENODEV;
+ goto out;
+ }
+ if (dev->mtu < so->ll.mtu) {
+ dev_put(dev);
+ err = -EINVAL;
+ goto out;
+ }
+ if (!(dev->flags & IFF_UP))
+ notify_enetdown = 1;
+
+ ifindex = dev->ifindex;
+
+ can_rx_register(net, dev, addr->can_addr.tp.rx_id,
+ SINGLE_MASK(addr->can_addr.tp.rx_id), isotp_rcv, sk,
+ "isotp", sk);
+
+ dev_put(dev);
+
+ if (so->bound) {
+ /* unregister old filter */
+ if (so->ifindex) {
+ dev = dev_get_by_index(net, so->ifindex);
+ if (dev) {
+ can_rx_unregister(net, dev, so->rxid,
+ SINGLE_MASK(so->rxid),
+ isotp_rcv, sk);
+ dev_put(dev);
+ }
+ }
+ }
+
+ /* switch to new settings */
+ so->ifindex = ifindex;
+ so->rxid = addr->can_addr.tp.rx_id;
+ so->txid = addr->can_addr.tp.tx_id;
+ so->bound = 1;
+
+out:
+ release_sock(sk);
+
+ if (notify_enetdown) {
+ sk->sk_err = ENETDOWN;
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_error_report(sk);
+ }
+
+ return err;
+}
+
+static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
+{
+ struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
+ struct sock *sk = sock->sk;
+ struct isotp_sock *so = isotp_sk(sk);
+
+ if (peer)
+ return -EOPNOTSUPP;
+
+ addr->can_family = AF_CAN;
+ addr->can_ifindex = so->ifindex;
+ addr->can_addr.tp.rx_id = so->rxid;
+ addr->can_addr.tp.tx_id = so->txid;
+
+ return sizeof(*addr);
+}
+
+static int isotp_setsockopt(struct socket *sock, int level, int optname,
+ sockptr_t optval, unsigned int optlen)
+{
+ struct sock *sk = sock->sk;
+ struct isotp_sock *so = isotp_sk(sk);
+ int ret = 0;
+
+ if (level != SOL_CAN_ISOTP)
+ return -EINVAL;
+ if (optlen < 0)
+ return -EINVAL;
+
+ switch (optname) {
+ case CAN_ISOTP_OPTS:
+ if (optlen != sizeof(struct can_isotp_options))
+ return -EINVAL;
+
+ if (copy_from_sockptr(&so->opt, optval, optlen))
+ return -EFAULT;
+
+ /* no separate rx_ext_address is given => use ext_address */
+ if (!(so->opt.flags & CAN_ISOTP_RX_EXT_ADDR))
+ so->opt.rx_ext_address = so->opt.ext_address;
+ break;
+
+ case CAN_ISOTP_RECV_FC:
+ if (optlen != sizeof(struct can_isotp_fc_options))
+ return -EINVAL;
+
+ if (copy_from_sockptr(&so->rxfc, optval, optlen))
+ return -EFAULT;
+ break;
+
+ case CAN_ISOTP_TX_STMIN:
+ if (optlen != sizeof(__u32))
+ return -EINVAL;
+
+ if (copy_from_sockptr(&so->force_tx_stmin, optval, optlen))
+ return -EFAULT;
+ break;
+
+ case CAN_ISOTP_RX_STMIN:
+ if (optlen != sizeof(__u32))
+ return -EINVAL;
+
+ if (copy_from_sockptr(&so->force_rx_stmin, optval, optlen))
+ return -EFAULT;
+ break;
+
+ case CAN_ISOTP_LL_OPTS:
+ if (optlen == sizeof(struct can_isotp_ll_options)) {
+ struct can_isotp_ll_options ll;
+
+ if (copy_from_sockptr(&ll, optval, optlen))
+ return -EFAULT;
+
+ /* check for correct ISO 11898-1 DLC data lentgh */
+ if (ll.tx_dl != padlen(ll.tx_dl))
+ return -EINVAL;
+
+ if (ll.mtu != CAN_MTU && ll.mtu != CANFD_MTU)
+ return -EINVAL;
+
+ if (ll.mtu == CAN_MTU && ll.tx_dl > CAN_MAX_DLEN)
+ return -EINVAL;
+
+ memcpy(&so->ll, &ll, sizeof(ll));
+
+ /* set ll_dl for tx path to similar place as for rx */
+ so->tx.ll_dl = ll.tx_dl;
+ } else {
+ return -EINVAL;
+ }
+ break;
+
+ default:
+ ret = -ENOPROTOOPT;
+ }
+
+ return ret;
+}
+
+static int isotp_getsockopt(struct socket *sock, int level, int optname,
+ char __user *optval, int __user *optlen)
+{
+ struct sock *sk = sock->sk;
+ struct isotp_sock *so = isotp_sk(sk);
+ int len;
+ void *val;
+
+ if (level != SOL_CAN_ISOTP)
+ return -EINVAL;
+ if (get_user(len, optlen))
+ return -EFAULT;
+ if (len < 0)
+ return -EINVAL;
+
+ switch (optname) {
+ case CAN_ISOTP_OPTS:
+ len = min_t(int, len, sizeof(struct can_isotp_options));
+ val = &so->opt;
+ break;
+
+ case CAN_ISOTP_RECV_FC:
+ len = min_t(int, len, sizeof(struct can_isotp_fc_options));
+ val = &so->rxfc;
+ break;
+
+ case CAN_ISOTP_TX_STMIN:
+ len = min_t(int, len, sizeof(__u32));
+ val = &so->force_tx_stmin;
+ break;
+
+ case CAN_ISOTP_RX_STMIN:
+ len = min_t(int, len, sizeof(__u32));
+ val = &so->force_rx_stmin;
+ break;
+
+ case CAN_ISOTP_LL_OPTS:
+ len = min_t(int, len, sizeof(struct can_isotp_ll_options));
+ val = &so->ll;
+ break;
+
+ default:
+ return -ENOPROTOOPT;
+ }
+
+ if (put_user(len, optlen))
+ return -EFAULT;
+ if (copy_to_user(optval, val, len))
+ return -EFAULT;
+ return 0;
+}
+
+static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
+ void *ptr)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+ struct isotp_sock *so = container_of(nb, struct isotp_sock, notifier);
+ struct sock *sk = &so->sk;
+
+ if (!net_eq(dev_net(dev), sock_net(sk)))
+ return NOTIFY_DONE;
+
+ if (dev->type != ARPHRD_CAN)
+ return NOTIFY_DONE;
+
+ if (so->ifindex != dev->ifindex)
+ return NOTIFY_DONE;
+
+ switch (msg) {
+ case NETDEV_UNREGISTER:
+ lock_sock(sk);
+ /* remove current filters & unregister */
+ if (so->bound)
+ can_rx_unregister(dev_net(dev), dev, so->rxid,
+ SINGLE_MASK(so->rxid),
+ isotp_rcv, sk);
+
+ so->ifindex = 0;
+ so->bound = 0;
+ release_sock(sk);
+
+ sk->sk_err = ENODEV;
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_error_report(sk);
+ break;
+
+ case NETDEV_DOWN:
+ sk->sk_err = ENETDOWN;
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_error_report(sk);
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static int isotp_init(struct sock *sk)
+{
+ struct isotp_sock *so = isotp_sk(sk);
+
+ so->ifindex = 0;
+ so->bound = 0;
+
+ so->opt.flags = CAN_ISOTP_DEFAULT_FLAGS;
+ so->opt.ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
+ so->opt.rx_ext_address = CAN_ISOTP_DEFAULT_EXT_ADDRESS;
+ so->opt.rxpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
+ so->opt.txpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
+ so->opt.frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
+ so->rxfc.bs = CAN_ISOTP_DEFAULT_RECV_BS;
+ so->rxfc.stmin = CAN_ISOTP_DEFAULT_RECV_STMIN;
+ so->rxfc.wftmax = CAN_ISOTP_DEFAULT_RECV_WFTMAX;
+ so->ll.mtu = CAN_ISOTP_DEFAULT_LL_MTU;
+ so->ll.tx_dl = CAN_ISOTP_DEFAULT_LL_TX_DL;
+ so->ll.tx_flags = CAN_ISOTP_DEFAULT_LL_TX_FLAGS;
+
+ /* set ll_dl for tx path to similar place as for rx */
+ so->tx.ll_dl = so->ll.tx_dl;
+
+ so->rx.state = ISOTP_IDLE;
+ so->tx.state = ISOTP_IDLE;
+
+ hrtimer_init(&so->rxtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
+ so->rxtimer.function = isotp_rx_timer_handler;
+ hrtimer_init(&so->txtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
+ so->txtimer.function = isotp_tx_timer_handler;
+
+ init_waitqueue_head(&so->wait);
+
+ so->notifier.notifier_call = isotp_notifier;
+ register_netdevice_notifier(&so->notifier);
+
+ return 0;
+}
+
+static int isotp_sock_no_ioctlcmd(struct socket *sock, unsigned int cmd,
+ unsigned long arg)
+{
+ /* no ioctls for socket layer -> hand it down to NIC layer */
+ return -ENOIOCTLCMD;
+}
+
+static const struct proto_ops isotp_ops = {
+ .family = PF_CAN,
+ .release = isotp_release,
+ .bind = isotp_bind,
+ .connect = sock_no_connect,
+ .socketpair = sock_no_socketpair,
+ .accept = sock_no_accept,
+ .getname = isotp_getname,
+ .poll = datagram_poll,
+ .ioctl = isotp_sock_no_ioctlcmd,
+ .gettstamp = sock_gettstamp,
+ .listen = sock_no_listen,
+ .shutdown = sock_no_shutdown,
+ .setsockopt = isotp_setsockopt,
+ .getsockopt = isotp_getsockopt,
+ .sendmsg = isotp_sendmsg,
+ .recvmsg = isotp_recvmsg,
+ .mmap = sock_no_mmap,
+ .sendpage = sock_no_sendpage,
+};
+
+static struct proto isotp_proto __read_mostly = {
+ .name = "CAN_ISOTP",
+ .owner = THIS_MODULE,
+ .obj_size = sizeof(struct isotp_sock),
+ .init = isotp_init,
+};
+
+static const struct can_proto isotp_can_proto = {
+ .type = SOCK_DGRAM,
+ .protocol = CAN_ISOTP,
+ .ops = &isotp_ops,
+ .prot = &isotp_proto,
+};
+
+static __init int isotp_module_init(void)
+{
+ int err;
+
+ pr_info("can: isotp protocol (rev " CAN_ISOTP_VERSION ")\n");
+
+ err = can_proto_register(&isotp_can_proto);
+ if (err < 0)
+ pr_err("can: registration of isotp protocol failed\n");
+
+ return err;
+}
+
+static __exit void isotp_module_exit(void)
+{
+ can_proto_unregister(&isotp_can_proto);
+}
+
+module_init(isotp_module_init);
+module_exit(isotp_module_exit);
