| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Oliver Hartkopp | 6513 | 95.99% | 16 | 41.03% |
| Yue haibing | 74 | 1.09% | 1 | 2.56% |
| Eric Dumazet | 62 | 0.91% | 2 | 5.13% |
| Thomas Graf | 57 | 0.84% | 4 | 10.26% |
| Florian Westphal | 21 | 0.31% | 2 | 5.13% |
| Johannes Berg | 14 | 0.21% | 3 | 7.69% |
| Linus Torvalds (pre-git) | 14 | 0.21% | 1 | 2.56% |
| Eric W. Biedermann | 10 | 0.15% | 2 | 5.13% |
| Marc Kleine-Budde | 7 | 0.10% | 2 | 5.13% |
| Ying Xue | 5 | 0.07% | 1 | 2.56% |
| Wei Yongjun | 3 | 0.04% | 1 | 2.56% |
| Darrel Goeddel | 2 | 0.03% | 1 | 2.56% |
| Joe Perches | 1 | 0.01% | 1 | 2.56% |
| Masahiro Yamada | 1 | 0.01% | 1 | 2.56% |
| Jiri Pirko | 1 | 0.01% | 1 | 2.56% |
| Total | 6785 | 39 |
// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) /* gw.c - CAN frame Gateway/Router/Bridge with netlink interface * * Copyright (c) 2019 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/types.h> #include <linux/kernel.h> #include <linux/list.h> #include <linux/spinlock.h> #include <linux/rcupdate.h> #include <linux/rculist.h> #include <linux/net.h> #include <linux/netdevice.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/gw.h> #include <net/rtnetlink.h> #include <net/net_namespace.h> #include <net/sock.h> #define CAN_GW_NAME "can-gw" MODULE_DESCRIPTION("PF_CAN netlink gateway"); MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>"); MODULE_ALIAS(CAN_GW_NAME); #define CGW_MIN_HOPS 1 #define CGW_MAX_HOPS 6 #define CGW_DEFAULT_HOPS 1 static unsigned int max_hops __read_mostly = CGW_DEFAULT_HOPS; module_param(max_hops, uint, 0444); MODULE_PARM_DESC(max_hops, "maximum " CAN_GW_NAME " routing hops for CAN frames " "(valid values: " __stringify(CGW_MIN_HOPS) "-" __stringify(CGW_MAX_HOPS) " hops, " "default: " __stringify(CGW_DEFAULT_HOPS) ")"); static struct notifier_block notifier; static struct kmem_cache *cgw_cache __read_mostly; /* structure that contains the (on-the-fly) CAN frame modifications */ struct cf_mod { struct { struct canfd_frame and; struct canfd_frame or; struct canfd_frame xor; struct canfd_frame set; } modframe; struct { u8 and; u8 or; u8 xor; u8 set; } modtype; void (*modfunc[MAX_MODFUNCTIONS])(struct canfd_frame *cf, struct cf_mod *mod); /* CAN frame checksum calculation after CAN frame modifications */ struct { struct cgw_csum_xor xor; struct cgw_csum_crc8 crc8; } csum; struct { void (*xor)(struct canfd_frame *cf, struct cgw_csum_xor *xor); void (*crc8)(struct canfd_frame *cf, struct cgw_csum_crc8 *crc8); } csumfunc; u32 uid; }; /* So far we just support CAN -> CAN routing and frame modifications. * * The internal can_can_gw structure contains data and attributes for * a CAN -> CAN gateway job. */ struct can_can_gw { struct can_filter filter; int src_idx; int dst_idx; }; /* list entry for CAN gateways jobs */ struct cgw_job { struct hlist_node list; struct rcu_head rcu; u32 handled_frames; u32 dropped_frames; u32 deleted_frames; struct cf_mod mod; union { /* CAN frame data source */ struct net_device *dev; } src; union { /* CAN frame data destination */ struct net_device *dev; } dst; union { struct can_can_gw ccgw; /* tbc */ }; u8 gwtype; u8 limit_hops; u16 flags; }; /* modification functions that are invoked in the hot path in can_can_gw_rcv */ #define MODFUNC(func, op) static void func(struct canfd_frame *cf, \ struct cf_mod *mod) { op ; } MODFUNC(mod_and_id, cf->can_id &= mod->modframe.and.can_id) MODFUNC(mod_and_len, cf->len &= mod->modframe.and.len) MODFUNC(mod_and_flags, cf->flags &= mod->modframe.and.flags) MODFUNC(mod_and_data, *(u64 *)cf->data &= *(u64 *)mod->modframe.and.data) MODFUNC(mod_or_id, cf->can_id |= mod->modframe.or.can_id) MODFUNC(mod_or_len, cf->len |= mod->modframe.or.len) MODFUNC(mod_or_flags, cf->flags |= mod->modframe.or.flags) MODFUNC(mod_or_data, *(u64 *)cf->data |= *(u64 *)mod->modframe.or.data) MODFUNC(mod_xor_id, cf->can_id ^= mod->modframe.xor.can_id) MODFUNC(mod_xor_len, cf->len ^= mod->modframe.xor.len) MODFUNC(mod_xor_flags, cf->flags ^= mod->modframe.xor.flags) MODFUNC(mod_xor_data, *(u64 *)cf->data ^= *(u64 *)mod->modframe.xor.data) MODFUNC(mod_set_id, cf->can_id = mod->modframe.set.can_id) MODFUNC(mod_set_len, cf->len = mod->modframe.set.len) MODFUNC(mod_set_flags, cf->flags = mod->modframe.set.flags) MODFUNC(mod_set_data, *(u64 *)cf->data = *(u64 *)mod->modframe.set.data) static void mod_and_fddata(struct canfd_frame *cf, struct cf_mod *mod) { int i; for (i = 0; i < CANFD_MAX_DLEN; i += 8) *(u64 *)(cf->data + i) &= *(u64 *)(mod->modframe.and.data + i); } static void mod_or_fddata(struct canfd_frame *cf, struct cf_mod *mod) { int i; for (i = 0; i < CANFD_MAX_DLEN; i += 8) *(u64 *)(cf->data + i) |= *(u64 *)(mod->modframe.or.data + i); } static void mod_xor_fddata(struct canfd_frame *cf, struct cf_mod *mod) { int i; for (i = 0; i < CANFD_MAX_DLEN; i += 8) *(u64 *)(cf->data + i) ^= *(u64 *)(mod->modframe.xor.data + i); } static void mod_set_fddata(struct canfd_frame *cf, struct cf_mod *mod) { memcpy(cf->data, mod->modframe.set.data, CANFD_MAX_DLEN); } /* retrieve valid CC DLC value and store it into 'len' */ static void mod_retrieve_ccdlc(struct canfd_frame *cf) { struct can_frame *ccf = (struct can_frame *)cf; /* len8_dlc is only valid if len == CAN_MAX_DLEN */ if (ccf->len != CAN_MAX_DLEN) return; /* do we have a valid len8_dlc value from 9 .. 15 ? */ if (ccf->len8_dlc > CAN_MAX_DLEN && ccf->len8_dlc <= CAN_MAX_RAW_DLC) ccf->len = ccf->len8_dlc; } /* convert valid CC DLC value in 'len' into struct can_frame elements */ static void mod_store_ccdlc(struct canfd_frame *cf) { struct can_frame *ccf = (struct can_frame *)cf; /* clear potential leftovers */ ccf->len8_dlc = 0; /* plain data length 0 .. 8 - that was easy */ if (ccf->len <= CAN_MAX_DLEN) return; /* potentially broken values are caught in can_can_gw_rcv() */ if (ccf->len > CAN_MAX_RAW_DLC) return; /* we have a valid dlc value from 9 .. 15 in ccf->len */ ccf->len8_dlc = ccf->len; ccf->len = CAN_MAX_DLEN; } static void mod_and_ccdlc(struct canfd_frame *cf, struct cf_mod *mod) { mod_retrieve_ccdlc(cf); mod_and_len(cf, mod); mod_store_ccdlc(cf); } static void mod_or_ccdlc(struct canfd_frame *cf, struct cf_mod *mod) { mod_retrieve_ccdlc(cf); mod_or_len(cf, mod); mod_store_ccdlc(cf); } static void mod_xor_ccdlc(struct canfd_frame *cf, struct cf_mod *mod) { mod_retrieve_ccdlc(cf); mod_xor_len(cf, mod); mod_store_ccdlc(cf); } static void mod_set_ccdlc(struct canfd_frame *cf, struct cf_mod *mod) { mod_set_len(cf, mod); mod_store_ccdlc(cf); } static void canframecpy(struct canfd_frame *dst, struct can_frame *src) { /* Copy the struct members separately to ensure that no uninitialized * data are copied in the 3 bytes hole of the struct. This is needed * to make easy compares of the data in the struct cf_mod. */ dst->can_id = src->can_id; dst->len = src->len; *(u64 *)dst->data = *(u64 *)src->data; } static void canfdframecpy(struct canfd_frame *dst, struct canfd_frame *src) { /* Copy the struct members separately to ensure that no uninitialized * data are copied in the 2 bytes hole of the struct. This is needed * to make easy compares of the data in the struct cf_mod. */ dst->can_id = src->can_id; dst->flags = src->flags; dst->len = src->len; memcpy(dst->data, src->data, CANFD_MAX_DLEN); } static int cgw_chk_csum_parms(s8 fr, s8 to, s8 re, struct rtcanmsg *r) { s8 dlen = CAN_MAX_DLEN; if (r->flags & CGW_FLAGS_CAN_FD) dlen = CANFD_MAX_DLEN; /* absolute dlc values 0 .. 7 => 0 .. 7, e.g. data [0] * relative to received dlc -1 .. -8 : * e.g. for received dlc = 8 * -1 => index = 7 (data[7]) * -3 => index = 5 (data[5]) * -8 => index = 0 (data[0]) */ if (fr >= -dlen && fr < dlen && to >= -dlen && to < dlen && re >= -dlen && re < dlen) return 0; else return -EINVAL; } static inline int calc_idx(int idx, int rx_len) { if (idx < 0) return rx_len + idx; else return idx; } static void cgw_csum_xor_rel(struct canfd_frame *cf, struct cgw_csum_xor *xor) { int from = calc_idx(xor->from_idx, cf->len); int to = calc_idx(xor->to_idx, cf->len); int res = calc_idx(xor->result_idx, cf->len); u8 val = xor->init_xor_val; int i; if (from < 0 || to < 0 || res < 0) return; if (from <= to) { for (i = from; i <= to; i++) val ^= cf->data[i]; } else { for (i = from; i >= to; i--) val ^= cf->data[i]; } cf->data[res] = val; } static void cgw_csum_xor_pos(struct canfd_frame *cf, struct cgw_csum_xor *xor) { u8 val = xor->init_xor_val; int i; for (i = xor->from_idx; i <= xor->to_idx; i++) val ^= cf->data[i]; cf->data[xor->result_idx] = val; } static void cgw_csum_xor_neg(struct canfd_frame *cf, struct cgw_csum_xor *xor) { u8 val = xor->init_xor_val; int i; for (i = xor->from_idx; i >= xor->to_idx; i--) val ^= cf->data[i]; cf->data[xor->result_idx] = val; } static void cgw_csum_crc8_rel(struct canfd_frame *cf, struct cgw_csum_crc8 *crc8) { int from = calc_idx(crc8->from_idx, cf->len); int to = calc_idx(crc8->to_idx, cf->len); int res = calc_idx(crc8->result_idx, cf->len); u8 crc = crc8->init_crc_val; int i; if (from < 0 || to < 0 || res < 0) return; if (from <= to) { for (i = crc8->from_idx; i <= crc8->to_idx; i++) crc = crc8->crctab[crc ^ cf->data[i]]; } else { for (i = crc8->from_idx; i >= crc8->to_idx; i--) crc = crc8->crctab[crc ^ cf->data[i]]; } switch (crc8->profile) { case CGW_CRC8PRF_1U8: crc = crc8->crctab[crc ^ crc8->profile_data[0]]; break; case CGW_CRC8PRF_16U8: crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]]; break; case CGW_CRC8PRF_SFFID_XOR: crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^ (cf->can_id >> 8 & 0xFF)]; break; } cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val; } static void cgw_csum_crc8_pos(struct canfd_frame *cf, struct cgw_csum_crc8 *crc8) { u8 crc = crc8->init_crc_val; int i; for (i = crc8->from_idx; i <= crc8->to_idx; i++) crc = crc8->crctab[crc ^ cf->data[i]]; switch (crc8->profile) { case CGW_CRC8PRF_1U8: crc = crc8->crctab[crc ^ crc8->profile_data[0]]; break; case CGW_CRC8PRF_16U8: crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]]; break; case CGW_CRC8PRF_SFFID_XOR: crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^ (cf->can_id >> 8 & 0xFF)]; break; } cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val; } static void cgw_csum_crc8_neg(struct canfd_frame *cf, struct cgw_csum_crc8 *crc8) { u8 crc = crc8->init_crc_val; int i; for (i = crc8->from_idx; i >= crc8->to_idx; i--) crc = crc8->crctab[crc ^ cf->data[i]]; switch (crc8->profile) { case CGW_CRC8PRF_1U8: crc = crc8->crctab[crc ^ crc8->profile_data[0]]; break; case CGW_CRC8PRF_16U8: crc = crc8->crctab[crc ^ crc8->profile_data[cf->data[1] & 0xF]]; break; case CGW_CRC8PRF_SFFID_XOR: crc = crc8->crctab[crc ^ (cf->can_id & 0xFF) ^ (cf->can_id >> 8 & 0xFF)]; break; } cf->data[crc8->result_idx] = crc ^ crc8->final_xor_val; } /* the receive & process & send function */ static void can_can_gw_rcv(struct sk_buff *skb, void *data) { struct cgw_job *gwj = (struct cgw_job *)data; struct canfd_frame *cf; struct sk_buff *nskb; int modidx = 0; /* process strictly Classic CAN or CAN FD frames */ if (gwj->flags & CGW_FLAGS_CAN_FD) { if (!can_is_canfd_skb(skb)) return; } else { if (!can_is_can_skb(skb)) return; } /* Do not handle CAN frames routed more than 'max_hops' times. * In general we should never catch this delimiter which is intended * to cover a misconfiguration protection (e.g. circular CAN routes). * * The Controller Area Network controllers only accept CAN frames with * correct CRCs - which are not visible in the controller registers. * According to skbuff.h documentation the csum_start element for IP * checksums is undefined/unused when ip_summed == CHECKSUM_UNNECESSARY. * Only CAN skbs can be processed here which already have this property. */ #define cgw_hops(skb) ((skb)->csum_start) BUG_ON(skb->ip_summed != CHECKSUM_UNNECESSARY); if (cgw_hops(skb) >= max_hops) { /* indicate deleted frames due to misconfiguration */ gwj->deleted_frames++; return; } if (!(gwj->dst.dev->flags & IFF_UP)) { gwj->dropped_frames++; return; } /* is sending the skb back to the incoming interface not allowed? */ if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) && can_skb_prv(skb)->ifindex == gwj->dst.dev->ifindex) return; /* clone the given skb, which has not been done in can_rcv() * * When there is at least one modification function activated, * we need to copy the skb as we want to modify skb->data. */ if (gwj->mod.modfunc[0]) nskb = skb_copy(skb, GFP_ATOMIC); else nskb = skb_clone(skb, GFP_ATOMIC); if (!nskb) { gwj->dropped_frames++; return; } /* put the incremented hop counter in the cloned skb */ cgw_hops(nskb) = cgw_hops(skb) + 1; /* first processing of this CAN frame -> adjust to private hop limit */ if (gwj->limit_hops && cgw_hops(nskb) == 1) cgw_hops(nskb) = max_hops - gwj->limit_hops + 1; nskb->dev = gwj->dst.dev; /* pointer to modifiable CAN frame */ cf = (struct canfd_frame *)nskb->data; /* perform preprocessed modification functions if there are any */ while (modidx < MAX_MODFUNCTIONS && gwj->mod.modfunc[modidx]) (*gwj->mod.modfunc[modidx++])(cf, &gwj->mod); /* Has the CAN frame been modified? */ if (modidx) { /* get available space for the processed CAN frame type */ int max_len = nskb->len - offsetof(struct canfd_frame, data); /* dlc may have changed, make sure it fits to the CAN frame */ if (cf->len > max_len) { /* delete frame due to misconfiguration */ gwj->deleted_frames++; kfree_skb(nskb); return; } /* check for checksum updates */ if (gwj->mod.csumfunc.crc8) (*gwj->mod.csumfunc.crc8)(cf, &gwj->mod.csum.crc8); if (gwj->mod.csumfunc.xor) (*gwj->mod.csumfunc.xor)(cf, &gwj->mod.csum.xor); } /* clear the skb timestamp if not configured the other way */ if (!(gwj->flags & CGW_FLAGS_CAN_SRC_TSTAMP)) nskb->tstamp = 0; /* send to netdevice */ if (can_send(nskb, gwj->flags & CGW_FLAGS_CAN_ECHO)) gwj->dropped_frames++; else gwj->handled_frames++; } static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj) { return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id, gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj, "gw", NULL); } static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj) { can_rx_unregister(net, gwj->src.dev, gwj->ccgw.filter.can_id, gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj); } static void cgw_job_free_rcu(struct rcu_head *rcu_head) { struct cgw_job *gwj = container_of(rcu_head, struct cgw_job, rcu); kmem_cache_free(cgw_cache, gwj); } static int cgw_notifier(struct notifier_block *nb, unsigned long msg, void *ptr) { struct net_device *dev = netdev_notifier_info_to_dev(ptr); struct net *net = dev_net(dev); if (dev->type != ARPHRD_CAN) return NOTIFY_DONE; if (msg == NETDEV_UNREGISTER) { struct cgw_job *gwj = NULL; struct hlist_node *nx; ASSERT_RTNL(); hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { if (gwj->src.dev == dev || gwj->dst.dev == dev) { hlist_del(&gwj->list); cgw_unregister_filter(net, gwj); call_rcu(&gwj->rcu, cgw_job_free_rcu); } } } return NOTIFY_DONE; } static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type, u32 pid, u32 seq, int flags) { struct rtcanmsg *rtcan; struct nlmsghdr *nlh; nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtcan), flags); if (!nlh) return -EMSGSIZE; rtcan = nlmsg_data(nlh); rtcan->can_family = AF_CAN; rtcan->gwtype = gwj->gwtype; rtcan->flags = gwj->flags; /* add statistics if available */ if (gwj->handled_frames) { if (nla_put_u32(skb, CGW_HANDLED, gwj->handled_frames) < 0) goto cancel; } if (gwj->dropped_frames) { if (nla_put_u32(skb, CGW_DROPPED, gwj->dropped_frames) < 0) goto cancel; } if (gwj->deleted_frames) { if (nla_put_u32(skb, CGW_DELETED, gwj->deleted_frames) < 0) goto cancel; } /* check non default settings of attributes */ if (gwj->limit_hops) { if (nla_put_u8(skb, CGW_LIM_HOPS, gwj->limit_hops) < 0) goto cancel; } if (gwj->flags & CGW_FLAGS_CAN_FD) { struct cgw_fdframe_mod mb; if (gwj->mod.modtype.and) { memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf)); mb.modtype = gwj->mod.modtype.and; if (nla_put(skb, CGW_FDMOD_AND, sizeof(mb), &mb) < 0) goto cancel; } if (gwj->mod.modtype.or) { memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf)); mb.modtype = gwj->mod.modtype.or; if (nla_put(skb, CGW_FDMOD_OR, sizeof(mb), &mb) < 0) goto cancel; } if (gwj->mod.modtype.xor) { memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf)); mb.modtype = gwj->mod.modtype.xor; if (nla_put(skb, CGW_FDMOD_XOR, sizeof(mb), &mb) < 0) goto cancel; } if (gwj->mod.modtype.set) { memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf)); mb.modtype = gwj->mod.modtype.set; if (nla_put(skb, CGW_FDMOD_SET, sizeof(mb), &mb) < 0) goto cancel; } } else { struct cgw_frame_mod mb; if (gwj->mod.modtype.and) { memcpy(&mb.cf, &gwj->mod.modframe.and, sizeof(mb.cf)); mb.modtype = gwj->mod.modtype.and; if (nla_put(skb, CGW_MOD_AND, sizeof(mb), &mb) < 0) goto cancel; } if (gwj->mod.modtype.or) { memcpy(&mb.cf, &gwj->mod.modframe.or, sizeof(mb.cf)); mb.modtype = gwj->mod.modtype.or; if (nla_put(skb, CGW_MOD_OR, sizeof(mb), &mb) < 0) goto cancel; } if (gwj->mod.modtype.xor) { memcpy(&mb.cf, &gwj->mod.modframe.xor, sizeof(mb.cf)); mb.modtype = gwj->mod.modtype.xor; if (nla_put(skb, CGW_MOD_XOR, sizeof(mb), &mb) < 0) goto cancel; } if (gwj->mod.modtype.set) { memcpy(&mb.cf, &gwj->mod.modframe.set, sizeof(mb.cf)); mb.modtype = gwj->mod.modtype.set; if (nla_put(skb, CGW_MOD_SET, sizeof(mb), &mb) < 0) goto cancel; } } if (gwj->mod.uid) { if (nla_put_u32(skb, CGW_MOD_UID, gwj->mod.uid) < 0) goto cancel; } if (gwj->mod.csumfunc.crc8) { if (nla_put(skb, CGW_CS_CRC8, CGW_CS_CRC8_LEN, &gwj->mod.csum.crc8) < 0) goto cancel; } if (gwj->mod.csumfunc.xor) { if (nla_put(skb, CGW_CS_XOR, CGW_CS_XOR_LEN, &gwj->mod.csum.xor) < 0) goto cancel; } if (gwj->gwtype == CGW_TYPE_CAN_CAN) { if (gwj->ccgw.filter.can_id || gwj->ccgw.filter.can_mask) { if (nla_put(skb, CGW_FILTER, sizeof(struct can_filter), &gwj->ccgw.filter) < 0) goto cancel; } if (nla_put_u32(skb, CGW_SRC_IF, gwj->ccgw.src_idx) < 0) goto cancel; if (nla_put_u32(skb, CGW_DST_IF, gwj->ccgw.dst_idx) < 0) goto cancel; } nlmsg_end(skb, nlh); return 0; cancel: nlmsg_cancel(skb, nlh); return -EMSGSIZE; } /* Dump information about all CAN gateway jobs, in response to RTM_GETROUTE */ static int cgw_dump_jobs(struct sk_buff *skb, struct netlink_callback *cb) { struct net *net = sock_net(skb->sk); struct cgw_job *gwj = NULL; int idx = 0; int s_idx = cb->args[0]; rcu_read_lock(); hlist_for_each_entry_rcu(gwj, &net->can.cgw_list, list) { if (idx < s_idx) goto cont; if (cgw_put_job(skb, gwj, RTM_NEWROUTE, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, NLM_F_MULTI) < 0) break; cont: idx++; } rcu_read_unlock(); cb->args[0] = idx; return skb->len; } static const struct nla_policy cgw_policy[CGW_MAX + 1] = { [CGW_MOD_AND] = { .len = sizeof(struct cgw_frame_mod) }, [CGW_MOD_OR] = { .len = sizeof(struct cgw_frame_mod) }, [CGW_MOD_XOR] = { .len = sizeof(struct cgw_frame_mod) }, [CGW_MOD_SET] = { .len = sizeof(struct cgw_frame_mod) }, [CGW_CS_XOR] = { .len = sizeof(struct cgw_csum_xor) }, [CGW_CS_CRC8] = { .len = sizeof(struct cgw_csum_crc8) }, [CGW_SRC_IF] = { .type = NLA_U32 }, [CGW_DST_IF] = { .type = NLA_U32 }, [CGW_FILTER] = { .len = sizeof(struct can_filter) }, [CGW_LIM_HOPS] = { .type = NLA_U8 }, [CGW_MOD_UID] = { .type = NLA_U32 }, [CGW_FDMOD_AND] = { .len = sizeof(struct cgw_fdframe_mod) }, [CGW_FDMOD_OR] = { .len = sizeof(struct cgw_fdframe_mod) }, [CGW_FDMOD_XOR] = { .len = sizeof(struct cgw_fdframe_mod) }, [CGW_FDMOD_SET] = { .len = sizeof(struct cgw_fdframe_mod) }, }; /* check for common and gwtype specific attributes */ static int cgw_parse_attr(struct nlmsghdr *nlh, struct cf_mod *mod, u8 gwtype, void *gwtypeattr, u8 *limhops) { struct nlattr *tb[CGW_MAX + 1]; struct rtcanmsg *r = nlmsg_data(nlh); int modidx = 0; int err = 0; /* initialize modification & checksum data space */ memset(mod, 0, sizeof(*mod)); err = nlmsg_parse_deprecated(nlh, sizeof(struct rtcanmsg), tb, CGW_MAX, cgw_policy, NULL); if (err < 0) return err; if (tb[CGW_LIM_HOPS]) { *limhops = nla_get_u8(tb[CGW_LIM_HOPS]); if (*limhops < 1 || *limhops > max_hops) return -EINVAL; } /* check for AND/OR/XOR/SET modifications */ if (r->flags & CGW_FLAGS_CAN_FD) { struct cgw_fdframe_mod mb; if (tb[CGW_FDMOD_AND]) { nla_memcpy(&mb, tb[CGW_FDMOD_AND], CGW_FDMODATTR_LEN); canfdframecpy(&mod->modframe.and, &mb.cf); mod->modtype.and = mb.modtype; if (mb.modtype & CGW_MOD_ID) mod->modfunc[modidx++] = mod_and_id; if (mb.modtype & CGW_MOD_LEN) mod->modfunc[modidx++] = mod_and_len; if (mb.modtype & CGW_MOD_FLAGS) mod->modfunc[modidx++] = mod_and_flags; if (mb.modtype & CGW_MOD_DATA) mod->modfunc[modidx++] = mod_and_fddata; } if (tb[CGW_FDMOD_OR]) { nla_memcpy(&mb, tb[CGW_FDMOD_OR], CGW_FDMODATTR_LEN); canfdframecpy(&mod->modframe.or, &mb.cf); mod->modtype.or = mb.modtype; if (mb.modtype & CGW_MOD_ID) mod->modfunc[modidx++] = mod_or_id; if (mb.modtype & CGW_MOD_LEN) mod->modfunc[modidx++] = mod_or_len; if (mb.modtype & CGW_MOD_FLAGS) mod->modfunc[modidx++] = mod_or_flags; if (mb.modtype & CGW_MOD_DATA) mod->modfunc[modidx++] = mod_or_fddata; } if (tb[CGW_FDMOD_XOR]) { nla_memcpy(&mb, tb[CGW_FDMOD_XOR], CGW_FDMODATTR_LEN); canfdframecpy(&mod->modframe.xor, &mb.cf); mod->modtype.xor = mb.modtype; if (mb.modtype & CGW_MOD_ID) mod->modfunc[modidx++] = mod_xor_id; if (mb.modtype & CGW_MOD_LEN) mod->modfunc[modidx++] = mod_xor_len; if (mb.modtype & CGW_MOD_FLAGS) mod->modfunc[modidx++] = mod_xor_flags; if (mb.modtype & CGW_MOD_DATA) mod->modfunc[modidx++] = mod_xor_fddata; } if (tb[CGW_FDMOD_SET]) { nla_memcpy(&mb, tb[CGW_FDMOD_SET], CGW_FDMODATTR_LEN); canfdframecpy(&mod->modframe.set, &mb.cf); mod->modtype.set = mb.modtype; if (mb.modtype & CGW_MOD_ID) mod->modfunc[modidx++] = mod_set_id; if (mb.modtype & CGW_MOD_LEN) mod->modfunc[modidx++] = mod_set_len; if (mb.modtype & CGW_MOD_FLAGS) mod->modfunc[modidx++] = mod_set_flags; if (mb.modtype & CGW_MOD_DATA) mod->modfunc[modidx++] = mod_set_fddata; } } else { struct cgw_frame_mod mb; if (tb[CGW_MOD_AND]) { nla_memcpy(&mb, tb[CGW_MOD_AND], CGW_MODATTR_LEN); canframecpy(&mod->modframe.and, &mb.cf); mod->modtype.and = mb.modtype; if (mb.modtype & CGW_MOD_ID) mod->modfunc[modidx++] = mod_and_id; if (mb.modtype & CGW_MOD_DLC) mod->modfunc[modidx++] = mod_and_ccdlc; if (mb.modtype & CGW_MOD_DATA) mod->modfunc[modidx++] = mod_and_data; } if (tb[CGW_MOD_OR]) { nla_memcpy(&mb, tb[CGW_MOD_OR], CGW_MODATTR_LEN); canframecpy(&mod->modframe.or, &mb.cf); mod->modtype.or = mb.modtype; if (mb.modtype & CGW_MOD_ID) mod->modfunc[modidx++] = mod_or_id; if (mb.modtype & CGW_MOD_DLC) mod->modfunc[modidx++] = mod_or_ccdlc; if (mb.modtype & CGW_MOD_DATA) mod->modfunc[modidx++] = mod_or_data; } if (tb[CGW_MOD_XOR]) { nla_memcpy(&mb, tb[CGW_MOD_XOR], CGW_MODATTR_LEN); canframecpy(&mod->modframe.xor, &mb.cf); mod->modtype.xor = mb.modtype; if (mb.modtype & CGW_MOD_ID) mod->modfunc[modidx++] = mod_xor_id; if (mb.modtype & CGW_MOD_DLC) mod->modfunc[modidx++] = mod_xor_ccdlc; if (mb.modtype & CGW_MOD_DATA) mod->modfunc[modidx++] = mod_xor_data; } if (tb[CGW_MOD_SET]) { nla_memcpy(&mb, tb[CGW_MOD_SET], CGW_MODATTR_LEN); canframecpy(&mod->modframe.set, &mb.cf); mod->modtype.set = mb.modtype; if (mb.modtype & CGW_MOD_ID) mod->modfunc[modidx++] = mod_set_id; if (mb.modtype & CGW_MOD_DLC) mod->modfunc[modidx++] = mod_set_ccdlc; if (mb.modtype & CGW_MOD_DATA) mod->modfunc[modidx++] = mod_set_data; } } /* check for checksum operations after CAN frame modifications */ if (modidx) { if (tb[CGW_CS_CRC8]) { struct cgw_csum_crc8 *c = nla_data(tb[CGW_CS_CRC8]); err = cgw_chk_csum_parms(c->from_idx, c->to_idx, c->result_idx, r); if (err) return err; nla_memcpy(&mod->csum.crc8, tb[CGW_CS_CRC8], CGW_CS_CRC8_LEN); /* select dedicated processing function to reduce * runtime operations in receive hot path. */ if (c->from_idx < 0 || c->to_idx < 0 || c->result_idx < 0) mod->csumfunc.crc8 = cgw_csum_crc8_rel; else if (c->from_idx <= c->to_idx) mod->csumfunc.crc8 = cgw_csum_crc8_pos; else mod->csumfunc.crc8 = cgw_csum_crc8_neg; } if (tb[CGW_CS_XOR]) { struct cgw_csum_xor *c = nla_data(tb[CGW_CS_XOR]); err = cgw_chk_csum_parms(c->from_idx, c->to_idx, c->result_idx, r); if (err) return err; nla_memcpy(&mod->csum.xor, tb[CGW_CS_XOR], CGW_CS_XOR_LEN); /* select dedicated processing function to reduce * runtime operations in receive hot path. */ if (c->from_idx < 0 || c->to_idx < 0 || c->result_idx < 0) mod->csumfunc.xor = cgw_csum_xor_rel; else if (c->from_idx <= c->to_idx) mod->csumfunc.xor = cgw_csum_xor_pos; else mod->csumfunc.xor = cgw_csum_xor_neg; } if (tb[CGW_MOD_UID]) nla_memcpy(&mod->uid, tb[CGW_MOD_UID], sizeof(u32)); } if (gwtype == CGW_TYPE_CAN_CAN) { /* check CGW_TYPE_CAN_CAN specific attributes */ struct can_can_gw *ccgw = (struct can_can_gw *)gwtypeattr; memset(ccgw, 0, sizeof(*ccgw)); /* check for can_filter in attributes */ if (tb[CGW_FILTER]) nla_memcpy(&ccgw->filter, tb[CGW_FILTER], sizeof(struct can_filter)); err = -ENODEV; /* specifying two interfaces is mandatory */ if (!tb[CGW_SRC_IF] || !tb[CGW_DST_IF]) return err; ccgw->src_idx = nla_get_u32(tb[CGW_SRC_IF]); ccgw->dst_idx = nla_get_u32(tb[CGW_DST_IF]); /* both indices set to 0 for flushing all routing entries */ if (!ccgw->src_idx && !ccgw->dst_idx) return 0; /* only one index set to 0 is an error */ if (!ccgw->src_idx || !ccgw->dst_idx) return err; } /* add the checks for other gwtypes here */ return 0; } static int cgw_create_job(struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { struct net *net = sock_net(skb->sk); struct rtcanmsg *r; struct cgw_job *gwj; struct cf_mod mod; struct can_can_gw ccgw; u8 limhops = 0; int err = 0; if (!netlink_capable(skb, CAP_NET_ADMIN)) return -EPERM; if (nlmsg_len(nlh) < sizeof(*r)) return -EINVAL; r = nlmsg_data(nlh); if (r->can_family != AF_CAN) return -EPFNOSUPPORT; /* so far we only support CAN -> CAN routings */ if (r->gwtype != CGW_TYPE_CAN_CAN) return -EINVAL; err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops); if (err < 0) return err; if (mod.uid) { ASSERT_RTNL(); /* check for updating an existing job with identical uid */ hlist_for_each_entry(gwj, &net->can.cgw_list, list) { if (gwj->mod.uid != mod.uid) continue; /* interfaces & filters must be identical */ if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw))) return -EINVAL; /* update modifications with disabled softirq & quit */ local_bh_disable(); memcpy(&gwj->mod, &mod, sizeof(mod)); local_bh_enable(); return 0; } } /* ifindex == 0 is not allowed for job creation */ if (!ccgw.src_idx || !ccgw.dst_idx) return -ENODEV; gwj = kmem_cache_alloc(cgw_cache, GFP_KERNEL); if (!gwj) return -ENOMEM; gwj->handled_frames = 0; gwj->dropped_frames = 0; gwj->deleted_frames = 0; gwj->flags = r->flags; gwj->gwtype = r->gwtype; gwj->limit_hops = limhops; /* insert already parsed information */ memcpy(&gwj->mod, &mod, sizeof(mod)); memcpy(&gwj->ccgw, &ccgw, sizeof(ccgw)); err = -ENODEV; gwj->src.dev = __dev_get_by_index(net, gwj->ccgw.src_idx); if (!gwj->src.dev) goto out; if (gwj->src.dev->type != ARPHRD_CAN) goto out; gwj->dst.dev = __dev_get_by_index(net, gwj->ccgw.dst_idx); if (!gwj->dst.dev) goto out; if (gwj->dst.dev->type != ARPHRD_CAN) goto out; /* is sending the skb back to the incoming interface intended? */ if (gwj->src.dev == gwj->dst.dev && !(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK)) { err = -EINVAL; goto out; } ASSERT_RTNL(); err = cgw_register_filter(net, gwj); if (!err) hlist_add_head_rcu(&gwj->list, &net->can.cgw_list); out: if (err) kmem_cache_free(cgw_cache, gwj); return err; } static void cgw_remove_all_jobs(struct net *net) { struct cgw_job *gwj = NULL; struct hlist_node *nx; ASSERT_RTNL(); hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { hlist_del(&gwj->list); cgw_unregister_filter(net, gwj); call_rcu(&gwj->rcu, cgw_job_free_rcu); } } static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { struct net *net = sock_net(skb->sk); struct cgw_job *gwj = NULL; struct hlist_node *nx; struct rtcanmsg *r; struct cf_mod mod; struct can_can_gw ccgw; u8 limhops = 0; int err = 0; if (!netlink_capable(skb, CAP_NET_ADMIN)) return -EPERM; if (nlmsg_len(nlh) < sizeof(*r)) return -EINVAL; r = nlmsg_data(nlh); if (r->can_family != AF_CAN) return -EPFNOSUPPORT; /* so far we only support CAN -> CAN routings */ if (r->gwtype != CGW_TYPE_CAN_CAN) return -EINVAL; err = cgw_parse_attr(nlh, &mod, CGW_TYPE_CAN_CAN, &ccgw, &limhops); if (err < 0) return err; /* two interface indices both set to 0 => remove all entries */ if (!ccgw.src_idx && !ccgw.dst_idx) { cgw_remove_all_jobs(net); return 0; } err = -EINVAL; ASSERT_RTNL(); /* remove only the first matching entry */ hlist_for_each_entry_safe(gwj, nx, &net->can.cgw_list, list) { if (gwj->flags != r->flags) continue; if (gwj->limit_hops != limhops) continue; /* we have a match when uid is enabled and identical */ if (gwj->mod.uid || mod.uid) { if (gwj->mod.uid != mod.uid) continue; } else { /* no uid => check for identical modifications */ if (memcmp(&gwj->mod, &mod, sizeof(mod))) continue; } /* if (r->gwtype == CGW_TYPE_CAN_CAN) - is made sure here */ if (memcmp(&gwj->ccgw, &ccgw, sizeof(ccgw))) continue; hlist_del(&gwj->list); cgw_unregister_filter(net, gwj); call_rcu(&gwj->rcu, cgw_job_free_rcu); err = 0; break; } return err; } static int __net_init cangw_pernet_init(struct net *net) { INIT_HLIST_HEAD(&net->can.cgw_list); return 0; } static void __net_exit cangw_pernet_exit_batch(struct list_head *net_list) { struct net *net; rtnl_lock(); list_for_each_entry(net, net_list, exit_list) cgw_remove_all_jobs(net); rtnl_unlock(); } static struct pernet_operations cangw_pernet_ops = { .init = cangw_pernet_init, .exit_batch = cangw_pernet_exit_batch, }; static __init int cgw_module_init(void) { int ret; /* sanitize given module parameter */ max_hops = clamp_t(unsigned int, max_hops, CGW_MIN_HOPS, CGW_MAX_HOPS); pr_info("can: netlink gateway - max_hops=%d\n", max_hops); ret = register_pernet_subsys(&cangw_pernet_ops); if (ret) return ret; ret = -ENOMEM; cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job), 0, 0, NULL); if (!cgw_cache) goto out_cache_create; /* set notifier */ notifier.notifier_call = cgw_notifier; ret = register_netdevice_notifier(¬ifier); if (ret) goto out_register_notifier; ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_GETROUTE, NULL, cgw_dump_jobs, 0); if (ret) goto out_rtnl_register1; ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_NEWROUTE, cgw_create_job, NULL, 0); if (ret) goto out_rtnl_register2; ret = rtnl_register_module(THIS_MODULE, PF_CAN, RTM_DELROUTE, cgw_remove_job, NULL, 0); if (ret) goto out_rtnl_register3; return 0; out_rtnl_register3: rtnl_unregister(PF_CAN, RTM_NEWROUTE); out_rtnl_register2: rtnl_unregister(PF_CAN, RTM_GETROUTE); out_rtnl_register1: unregister_netdevice_notifier(¬ifier); out_register_notifier: kmem_cache_destroy(cgw_cache); out_cache_create: unregister_pernet_subsys(&cangw_pernet_ops); return ret; } static __exit void cgw_module_exit(void) { rtnl_unregister_all(PF_CAN); unregister_netdevice_notifier(¬ifier); unregister_pernet_subsys(&cangw_pernet_ops); rcu_barrier(); /* Wait for completion of call_rcu()'s */ kmem_cache_destroy(cgw_cache); } module_init(cgw_module_init); module_exit(cgw_module_exit);
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