diff options
Diffstat (limited to 'net/can/isotp.c')
| -rw-r--r-- | net/can/isotp.c | 1737 |
1 files changed, 1737 insertions, 0 deletions
diff --git a/net/can/isotp.c b/net/can/isotp.c new file mode 100644 index 0000000000..d1c6f206f4 --- /dev/null +++ b/net/can/isotp.c @@ -0,0 +1,1737 @@ +// 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 <socketcan@hartkopp.net>"); +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 set the static buffer to + * something about 8 kbyte to be able to test this new functionality. + */ +#define DEFAULT_MAX_PDU_SIZE 8300 + +/* maximum PDU size before ISO 15765-2:2016 extension was 4095 */ +#define MAX_12BIT_PDU_SIZE 4095 + +/* limit the isotp pdu size from the optional module parameter to 1MByte */ +#define MAX_PDU_SIZE (1025 * 1024U) + +static unsigned int max_pdu_size __read_mostly = DEFAULT_MAX_PDU_SIZE; +module_param(max_pdu_size, uint, 0444); +MODULE_PARM_DESC(max_pdu_size, "maximum isotp pdu size (default " + __stringify(DEFAULT_MAX_PDU_SIZE) ")"); + +/* 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 { + u8 *buf; + unsigned int buflen; + unsigned int len; + unsigned int idx; + u32 state; + u8 bs; + u8 sn; + u8 ll_dl; + u8 sbuf[DEFAULT_MAX_PDU_SIZE]; +}; + +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; + + /* PDU size > default => try max_pdu_size */ + if (so->rx.len > so->rx.buflen && so->rx.buflen < max_pdu_size) { + u8 *newbuf = kmalloc(max_pdu_size, GFP_ATOMIC); + + if (newbuf) { + so->rx.buf = newbuf; + so->rx.buflen = max_pdu_size; + } + } + + if (so->rx.len > so->rx.buflen) { + /* 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 > MAX_12BIT_PDU_SIZE) { + /* 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; + } + + /* PDU size > default => try max_pdu_size */ + if (size > so->tx.buflen && so->tx.buflen < max_pdu_size) { + u8 *newbuf = kmalloc(max_pdu_size, GFP_KERNEL); + + if (newbuf) { + so->tx.buf = newbuf; + so->tx.buflen = max_pdu_size; + } + } + + if (!size || size > so->tx.buflen) { + 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; + + if (so->rx.buf != so->rx.sbuf) + kfree(so->rx.buf); + + if (so->tx.buf != so->tx.sbuf) + kfree(so->tx.buf); + + 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; + + so->rx.buf = so->rx.sbuf; + so->tx.buf = so->tx.sbuf; + so->rx.buflen = ARRAY_SIZE(so->rx.sbuf); + so->tx.buflen = ARRAY_SIZE(so->tx.sbuf); + + 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, +}; + +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; + + max_pdu_size = max_t(unsigned int, max_pdu_size, MAX_12BIT_PDU_SIZE); + max_pdu_size = min_t(unsigned int, max_pdu_size, MAX_PDU_SIZE); + + pr_info("can: isotp protocol (max_pdu_size %d)\n", max_pdu_size); + + 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); |