// 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') * - 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include MODULE_DESCRIPTION("PF_CAN isotp 15765-2:2016 protocol"); MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Oliver Hartkopp "); 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 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 list_head notifier; wait_queue_head_t wait; }; 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 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(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) { 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 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->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_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(1, 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; 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_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_ATOMIC); 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_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); 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, increasing txqueuelen may prevent this error\n"); } 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; /* 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 ((so->opt.flags & CAN_ISOTP_SF_BROADCAST) && (size > so->tx.ll_dl - SF_PCI_SZ4 - ae - off)) 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_zero(skb, so->ll.mtu); /* 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 */ 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)); 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) { __sockaddr_check_size(ISOTP_MIN_NAMELEN); msg->msg_namelen = ISOTP_MIN_NAMELEN; 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); 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); hrtimer_cancel(&so->txtimer); hrtimer_cancel(&so->rxtimer); /* remove current filters & unregister */ if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST))) { 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; int do_rx_reg = 1; if (len < ISOTP_MIN_NAMELEN) return -EINVAL; if (addr->can_addr.tp.tx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG)) return -EADDRNOTAVAIL; if (!addr->can_ifindex) return -ENODEV; lock_sock(sk); /* do not register frame reception for functional addressing */ if (so->opt.flags & CAN_ISOTP_SF_BROADCAST) do_rx_reg = 0; /* do not validate rx address for functional addressing */ if (do_rx_reg) { if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id) { err = -EADDRNOTAVAIL; goto out; } if (addr->can_addr.tp.rx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG)) { err = -EADDRNOTAVAIL; goto out; } } 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; if (do_rx_reg) 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 && do_rx_reg) { /* 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_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; 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 && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST))) 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_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->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); spin_lock(&isotp_notifier_lock); list_add_tail(&so->notifier, &isotp_notifier_list); spin_unlock(&isotp_notifier_lock); 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 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);