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- // SPDX-License-Identifier: (GPL-2.0 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')
- *
- * 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/spinlock.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>
- MODULE_DESCRIPTION("PF_CAN isotp 15765-2:2016 protocol");
- MODULE_LICENSE("Dual BSD/GPL");
- MODULE_AUTHOR("Oliver Hartkopp <[email protected]>");
- MODULE_ALIAS("can-proto-6");
- #define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)
- #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 64 kbyte to be able to test this new functionality.
- */
- #define MAX_MSG_LENGTH 66000
- /* 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)
- #define ISOTP_ALL_BC_FLAGS (CAN_ISOTP_SF_BROADCAST | CAN_ISOTP_CF_BROADCAST)
- /* 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 */
- #define ISOTP_FC_TIMEOUT 1 /* 1 sec */
- #define ISOTP_ECHO_TIMEOUT 2 /* 2 secs */
- enum {
- ISOTP_IDLE = 0,
- ISOTP_WAIT_FIRST_FC,
- ISOTP_WAIT_FC,
- ISOTP_WAIT_DATA,
- ISOTP_SENDING,
- ISOTP_SHUTDOWN,
- };
- struct tpcon {
- unsigned int idx;
- unsigned int len;
- u32 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, txfrtimer;
- struct can_isotp_options opt;
- struct can_isotp_fc_options rxfc, txfc;
- struct can_isotp_ll_options ll;
- u32 frame_txtime;
- u32 force_tx_stmin;
- u32 force_rx_stmin;
- u32 cfecho; /* consecutive frame echo tag */
- struct tpcon rx, tx;
- struct list_head notifier;
- wait_queue_head_t wait;
- spinlock_t rx_lock; /* protect single thread state machine */
- };
- static LIST_HEAD(isotp_notifier_list);
- static DEFINE_SPINLOCK(isotp_notifier_lock);
- static struct isotp_sock *isotp_busy_notifier;
- static inline struct isotp_sock *isotp_sk(const struct sock *sk)
- {
- return (struct isotp_sock *)sk;
- }
- static u32 isotp_bc_flags(struct isotp_sock *so)
- {
- return so->opt.flags & ISOTP_ALL_BC_FLAGS;
- }
- static bool isotp_register_rxid(struct isotp_sock *so)
- {
- /* no broadcast modes => register rx_id for FC frame reception */
- return (isotp_bc_flags(so) == 0);
- }
- 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_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_zero(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;
- ncf->flags = so->ll.tx_flags;
- can_send_ret = can_send(nskb, 1);
- if (can_send_ret)
- pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
- __func__, ERR_PTR(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(ISOTP_FC_TIMEOUT, 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)
- {
- static 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 void isotp_send_cframe(struct isotp_sock *so);
- 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_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->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;
- /* send CF frame and enable echo timeout handling */
- hrtimer_start(&so->txtimer, ktime_set(ISOTP_ECHO_TIMEOUT, 0),
- HRTIMER_MODE_REL_SOFT);
- isotp_send_cframe(so);
- break;
- case ISOTP_FC_WT:
- /* start timer to wait for next FC frame */
- hrtimer_start(&so->txtimer, ktime_set(ISOTP_FC_TIMEOUT, 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_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_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 reception */
- 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_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_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;
- }
- /* 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(ISOTP_FC_TIMEOUT, 0),
- HRTIMER_MODE_REL_SOFT);
- return 0;
- }
- /* no creation of flow control frames */
- if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
- 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 reception of my configured extended address */
- if (ae && cf->data[0] != so->opt.rx_ext_address)
- return;
- n_pci_type = cf->data[ae] & 0xF0;
- /* Make sure the state changes and data structures stay consistent at
- * CAN frame reception time. This locking is not needed in real world
- * use cases but the inconsistency can be triggered with syzkaller.
- */
- spin_lock(&so->rx_lock);
- 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))
- goto out_unlock;
- }
- 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 (can_is_canfd_skb(skb)) {
- /* 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;
- }
- out_unlock:
- spin_unlock(&so->rx_lock);
- }
- 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_send_cframe(struct isotp_sock *so)
- {
- struct sock *sk = &so->sk;
- struct sk_buff *skb;
- struct net_device *dev;
- struct canfd_frame *cf;
- int can_send_ret;
- int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
- dev = dev_get_by_index(sock_net(sk), so->ifindex);
- if (!dev)
- return;
- skb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), GFP_ATOMIC);
- if (!skb) {
- dev_put(dev);
- return;
- }
- 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_zero(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++;
- cf->flags = so->ll.tx_flags;
- skb->dev = dev;
- can_skb_set_owner(skb, sk);
- /* cfecho should have been zero'ed by init/isotp_rcv_echo() */
- if (so->cfecho)
- pr_notice_once("can-isotp: cfecho is %08X != 0\n", so->cfecho);
- /* set consecutive frame echo tag */
- so->cfecho = *(u32 *)cf->data;
- /* send frame with local echo enabled */
- can_send_ret = can_send(skb, 1);
- if (can_send_ret) {
- pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
- __func__, ERR_PTR(can_send_ret));
- if (can_send_ret == -ENOBUFS)
- pr_notice_once("can-isotp: tx queue is full\n");
- }
- dev_put(dev);
- }
- 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;
- }
- static void isotp_rcv_echo(struct sk_buff *skb, void *data)
- {
- struct sock *sk = (struct sock *)data;
- struct isotp_sock *so = isotp_sk(sk);
- struct canfd_frame *cf = (struct canfd_frame *)skb->data;
- /* only handle my own local echo CF/SF skb's (no FF!) */
- if (skb->sk != sk || so->cfecho != *(u32 *)cf->data)
- return;
- /* cancel local echo timeout */
- hrtimer_cancel(&so->txtimer);
- /* local echo skb with consecutive frame has been consumed */
- so->cfecho = 0;
- if (so->tx.idx >= so->tx.len) {
- /* we are done */
- so->tx.state = ISOTP_IDLE;
- wake_up_interruptible(&so->wait);
- return;
- }
- if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
- /* stop and wait for FC with timeout */
- so->tx.state = ISOTP_WAIT_FC;
- hrtimer_start(&so->txtimer, ktime_set(ISOTP_FC_TIMEOUT, 0),
- HRTIMER_MODE_REL_SOFT);
- return;
- }
- /* no gap between data frames needed => use burst mode */
- if (!so->tx_gap) {
- /* enable echo timeout handling */
- hrtimer_start(&so->txtimer, ktime_set(ISOTP_ECHO_TIMEOUT, 0),
- HRTIMER_MODE_REL_SOFT);
- isotp_send_cframe(so);
- return;
- }
- /* start timer to send next consecutive frame with correct delay */
- hrtimer_start(&so->txfrtimer, so->tx_gap, HRTIMER_MODE_REL_SOFT);
- }
- 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;
- /* don't handle timeouts in IDLE or SHUTDOWN state */
- if (so->tx.state == ISOTP_IDLE || so->tx.state == ISOTP_SHUTDOWN)
- return HRTIMER_NORESTART;
- /* we did not get any flow control or echo frame in time */
- /* report 'communication error on send' */
- sk->sk_err = ECOMM;
- if (!sock_flag(sk, SOCK_DEAD))
- sk_error_report(sk);
- /* reset tx state */
- so->tx.state = ISOTP_IDLE;
- wake_up_interruptible(&so->wait);
- return HRTIMER_NORESTART;
- }
- static enum hrtimer_restart isotp_txfr_timer_handler(struct hrtimer *hrtimer)
- {
- struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
- txfrtimer);
- /* start echo timeout handling and cover below protocol error */
- hrtimer_start(&so->txtimer, ktime_set(ISOTP_ECHO_TIMEOUT, 0),
- HRTIMER_MODE_REL_SOFT);
- /* cfecho should be consumed by isotp_rcv_echo() here */
- if (so->tx.state == ISOTP_SENDING && !so->cfecho)
- isotp_send_cframe(so);
- return HRTIMER_NORESTART;
- }
- 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;
- s64 hrtimer_sec = ISOTP_ECHO_TIMEOUT;
- int off;
- int err;
- if (!so->bound || so->tx.state == ISOTP_SHUTDOWN)
- return -EADDRNOTAVAIL;
- while (cmpxchg(&so->tx.state, ISOTP_IDLE, ISOTP_SENDING) != ISOTP_IDLE) {
- /* we do not support multiple buffers - for now */
- if (msg->msg_flags & MSG_DONTWAIT)
- return -EAGAIN;
- if (so->tx.state == ISOTP_SHUTDOWN)
- return -EADDRNOTAVAIL;
- /* wait for complete transmission of current pdu */
- err = wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
- if (err)
- goto err_event_drop;
- }
- if (!size || size > MAX_MSG_LENGTH) {
- err = -EINVAL;
- goto err_out_drop;
- }
- /* take care of a potential SF_DL ESC offset for TX_DL > 8 */
- off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;
- /* does the given data fit into a single frame for SF_BROADCAST? */
- if ((isotp_bc_flags(so) == CAN_ISOTP_SF_BROADCAST) &&
- (size > so->tx.ll_dl - SF_PCI_SZ4 - ae - off)) {
- err = -EINVAL;
- goto err_out_drop;
- }
- err = memcpy_from_msg(so->tx.buf, msg, size);
- if (err < 0)
- goto err_out_drop;
- dev = dev_get_by_index(sock_net(sk), so->ifindex);
- if (!dev) {
- err = -ENXIO;
- goto err_out_drop;
- }
- 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);
- goto err_out_drop;
- }
- can_skb_reserve(skb);
- can_skb_prv(skb)->ifindex = dev->ifindex;
- can_skb_prv(skb)->skbcnt = 0;
- so->tx.len = size;
- so->tx.idx = 0;
- cf = (struct canfd_frame *)skb->data;
- skb_put_zero(skb, so->ll.mtu);
- /* cfecho should have been zero'ed by init / former isotp_rcv_echo() */
- if (so->cfecho)
- pr_notice_once("can-isotp: uninit cfecho %08X\n", so->cfecho);
- /* 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;
- /* set CF echo tag for isotp_rcv_echo() (SF-mode) */
- so->cfecho = *(u32 *)cf->data;
- } else {
- /* send first frame */
- isotp_create_fframe(cf, so, ae);
- if (isotp_bc_flags(so) == CAN_ISOTP_CF_BROADCAST) {
- /* set timer for FC-less operation (STmin = 0) */
- if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
- so->tx_gap = ktime_set(0, so->force_tx_stmin);
- else
- so->tx_gap = ktime_set(0, so->frame_txtime);
- /* disable wait for FCs due to activated block size */
- so->txfc.bs = 0;
- /* set CF echo tag for isotp_rcv_echo() (CF-mode) */
- so->cfecho = *(u32 *)cf->data;
- } else {
- /* standard flow control check */
- so->tx.state = ISOTP_WAIT_FIRST_FC;
- /* start timeout for FC */
- hrtimer_sec = ISOTP_FC_TIMEOUT;
- /* no CF echo tag for isotp_rcv_echo() (FF-mode) */
- so->cfecho = 0;
- }
- }
- hrtimer_start(&so->txtimer, ktime_set(hrtimer_sec, 0),
- HRTIMER_MODE_REL_SOFT);
- /* send the first or only CAN frame */
- cf->flags = so->ll.tx_flags;
- skb->dev = dev;
- skb->sk = sk;
- err = can_send(skb, 1);
- dev_put(dev);
- if (err) {
- pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
- __func__, ERR_PTR(err));
- /* no transmission -> no timeout monitoring */
- hrtimer_cancel(&so->txtimer);
- /* reset consecutive frame echo tag */
- so->cfecho = 0;
- goto err_out_drop;
- }
- if (wait_tx_done) {
- /* wait for complete transmission of current pdu */
- err = wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
- if (err)
- goto err_event_drop;
- err = sock_error(sk);
- if (err)
- return err;
- }
- return size;
- err_event_drop:
- /* got signal: force tx state machine to be idle */
- so->tx.state = ISOTP_IDLE;
- hrtimer_cancel(&so->txfrtimer);
- hrtimer_cancel(&so->txtimer);
- err_out_drop:
- /* drop this PDU and unlock a potential wait queue */
- so->tx.state = ISOTP_IDLE;
- wake_up_interruptible(&so->wait);
- return err;
- }
- static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
- int flags)
- {
- struct sock *sk = sock->sk;
- struct sk_buff *skb;
- struct isotp_sock *so = isotp_sk(sk);
- int ret = 0;
- if (flags & ~(MSG_DONTWAIT | MSG_TRUNC | MSG_PEEK | MSG_CMSG_COMPAT))
- return -EINVAL;
- if (!so->bound)
- return -EADDRNOTAVAIL;
- skb = skb_recv_datagram(sk, flags, &ret);
- if (!skb)
- return ret;
- if (size < skb->len)
- msg->msg_flags |= MSG_TRUNC;
- else
- size = skb->len;
- ret = memcpy_to_msg(msg, skb->data, size);
- if (ret < 0)
- goto out_err;
- sock_recv_cmsgs(msg, sk, skb);
- if (msg->msg_name) {
- __sockaddr_check_size(ISOTP_MIN_NAMELEN);
- msg->msg_namelen = ISOTP_MIN_NAMELEN;
- memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
- }
- /* set length of return value */
- ret = (flags & MSG_TRUNC) ? skb->len : size;
- out_err:
- skb_free_datagram(sk, skb);
- return ret;
- }
- 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 */
- while (wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE) == 0 &&
- cmpxchg(&so->tx.state, ISOTP_IDLE, ISOTP_SHUTDOWN) != ISOTP_IDLE)
- ;
- /* force state machines to be idle also when a signal occurred */
- so->tx.state = ISOTP_SHUTDOWN;
- so->rx.state = ISOTP_IDLE;
- spin_lock(&isotp_notifier_lock);
- while (isotp_busy_notifier == so) {
- spin_unlock(&isotp_notifier_lock);
- schedule_timeout_uninterruptible(1);
- spin_lock(&isotp_notifier_lock);
- }
- list_del(&so->notifier);
- spin_unlock(&isotp_notifier_lock);
- lock_sock(sk);
- /* remove current filters & unregister */
- if (so->bound) {
- if (so->ifindex) {
- struct net_device *dev;
- dev = dev_get_by_index(net, so->ifindex);
- if (dev) {
- if (isotp_register_rxid(so))
- can_rx_unregister(net, dev, so->rxid,
- SINGLE_MASK(so->rxid),
- isotp_rcv, sk);
- can_rx_unregister(net, dev, so->txid,
- SINGLE_MASK(so->txid),
- isotp_rcv_echo, sk);
- dev_put(dev);
- synchronize_rcu();
- }
- }
- }
- hrtimer_cancel(&so->txfrtimer);
- hrtimer_cancel(&so->txtimer);
- hrtimer_cancel(&so->rxtimer);
- 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;
- canid_t tx_id = addr->can_addr.tp.tx_id;
- canid_t rx_id = addr->can_addr.tp.rx_id;
- int err = 0;
- int notify_enetdown = 0;
- if (len < ISOTP_MIN_NAMELEN)
- return -EINVAL;
- if (addr->can_family != AF_CAN)
- return -EINVAL;
- /* sanitize tx CAN identifier */
- if (tx_id & CAN_EFF_FLAG)
- tx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
- else
- tx_id &= CAN_SFF_MASK;
- /* give feedback on wrong CAN-ID value */
- if (tx_id != addr->can_addr.tp.tx_id)
- return -EINVAL;
- /* sanitize rx CAN identifier (if needed) */
- if (isotp_register_rxid(so)) {
- if (rx_id & CAN_EFF_FLAG)
- rx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
- else
- rx_id &= CAN_SFF_MASK;
- /* give feedback on wrong CAN-ID value */
- if (rx_id != addr->can_addr.tp.rx_id)
- return -EINVAL;
- }
- if (!addr->can_ifindex)
- return -ENODEV;
- lock_sock(sk);
- if (so->bound) {
- err = -EINVAL;
- goto out;
- }
- /* ensure different CAN IDs when the rx_id is to be registered */
- if (isotp_register_rxid(so) && rx_id == tx_id) {
- err = -EADDRNOTAVAIL;
- 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;
- if (isotp_register_rxid(so))
- can_rx_register(net, dev, rx_id, SINGLE_MASK(rx_id),
- isotp_rcv, sk, "isotp", sk);
- /* no consecutive frame echo skb in flight */
- so->cfecho = 0;
- /* register for echo skb's */
- can_rx_register(net, dev, tx_id, SINGLE_MASK(tx_id),
- isotp_rcv_echo, sk, "isotpe", sk);
- dev_put(dev);
- /* switch to new settings */
- so->ifindex = ifindex;
- so->rxid = rx_id;
- so->txid = tx_id;
- so->bound = 1;
- out:
- release_sock(sk);
- if (notify_enetdown) {
- sk->sk_err = ENETDOWN;
- if (!sock_flag(sk, SOCK_DEAD))
- 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;
- memset(addr, 0, ISOTP_MIN_NAMELEN);
- 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 ISOTP_MIN_NAMELEN;
- }
- static int isotp_setsockopt_locked(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 (so->bound)
- return -EISCONN;
- 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;
- /* these broadcast flags are not allowed together */
- if (isotp_bc_flags(so) == ISOTP_ALL_BC_FLAGS) {
- /* CAN_ISOTP_SF_BROADCAST is prioritized */
- so->opt.flags &= ~CAN_ISOTP_CF_BROADCAST;
- /* give user feedback on wrong config attempt */
- ret = -EINVAL;
- }
- /* check for frame_txtime changes (0 => no changes) */
- if (so->opt.frame_txtime) {
- if (so->opt.frame_txtime == CAN_ISOTP_FRAME_TXTIME_ZERO)
- so->frame_txtime = 0;
- else
- so->frame_txtime = so->opt.frame_txtime;
- }
- 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 length */
- 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 || ll.tx_flags != 0))
- 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_setsockopt(struct socket *sock, int level, int optname,
- sockptr_t optval, unsigned int optlen)
- {
- struct sock *sk = sock->sk;
- int ret;
- if (level != SOL_CAN_ISOTP)
- return -EINVAL;
- lock_sock(sk);
- ret = isotp_setsockopt_locked(sock, level, optname, optval, optlen);
- release_sock(sk);
- 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 void isotp_notify(struct isotp_sock *so, unsigned long msg,
- struct net_device *dev)
- {
- struct sock *sk = &so->sk;
- if (!net_eq(dev_net(dev), sock_net(sk)))
- return;
- if (so->ifindex != dev->ifindex)
- return;
- switch (msg) {
- case NETDEV_UNREGISTER:
- lock_sock(sk);
- /* remove current filters & unregister */
- if (so->bound) {
- if (isotp_register_rxid(so))
- can_rx_unregister(dev_net(dev), dev, so->rxid,
- SINGLE_MASK(so->rxid),
- isotp_rcv, sk);
- can_rx_unregister(dev_net(dev), dev, so->txid,
- SINGLE_MASK(so->txid),
- isotp_rcv_echo, sk);
- }
- so->ifindex = 0;
- so->bound = 0;
- release_sock(sk);
- sk->sk_err = ENODEV;
- if (!sock_flag(sk, SOCK_DEAD))
- sk_error_report(sk);
- break;
- case NETDEV_DOWN:
- sk->sk_err = ENETDOWN;
- if (!sock_flag(sk, SOCK_DEAD))
- sk_error_report(sk);
- break;
- }
- }
- static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
- void *ptr)
- {
- struct net_device *dev = netdev_notifier_info_to_dev(ptr);
- if (dev->type != ARPHRD_CAN)
- return NOTIFY_DONE;
- if (msg != NETDEV_UNREGISTER && msg != NETDEV_DOWN)
- return NOTIFY_DONE;
- if (unlikely(isotp_busy_notifier)) /* Check for reentrant bug. */
- return NOTIFY_DONE;
- spin_lock(&isotp_notifier_lock);
- list_for_each_entry(isotp_busy_notifier, &isotp_notifier_list, notifier) {
- spin_unlock(&isotp_notifier_lock);
- isotp_notify(isotp_busy_notifier, msg, dev);
- spin_lock(&isotp_notifier_lock);
- }
- isotp_busy_notifier = NULL;
- spin_unlock(&isotp_notifier_lock);
- 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->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;
- hrtimer_init(&so->txfrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_SOFT);
- so->txfrtimer.function = isotp_txfr_timer_handler;
- init_waitqueue_head(&so->wait);
- spin_lock_init(&so->rx_lock);
- spin_lock(&isotp_notifier_lock);
- list_add_tail(&so->notifier, &isotp_notifier_list);
- spin_unlock(&isotp_notifier_lock);
- return 0;
- }
- static __poll_t isotp_poll(struct file *file, struct socket *sock, poll_table *wait)
- {
- struct sock *sk = sock->sk;
- struct isotp_sock *so = isotp_sk(sk);
- __poll_t mask = datagram_poll(file, sock, wait);
- poll_wait(file, &so->wait, wait);
- /* Check for false positives due to TX state */
- if ((mask & EPOLLWRNORM) && (so->tx.state != ISOTP_IDLE))
- mask &= ~(EPOLLOUT | EPOLLWRNORM);
- return mask;
- }
- 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 = isotp_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 struct notifier_block canisotp_notifier = {
- .notifier_call = isotp_notifier
- };
- static __init int isotp_module_init(void)
- {
- int err;
- pr_info("can: isotp protocol\n");
- err = can_proto_register(&isotp_can_proto);
- if (err < 0)
- pr_err("can: registration of isotp protocol failed %pe\n", ERR_PTR(err));
- else
- register_netdevice_notifier(&canisotp_notifier);
- return err;
- }
- static __exit void isotp_module_exit(void)
- {
- can_proto_unregister(&isotp_can_proto);
- unregister_netdevice_notifier(&canisotp_notifier);
- }
- module_init(isotp_module_init);
- module_exit(isotp_module_exit);
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