diff options
Diffstat (limited to 'net/can/af_can.c')
| -rw-r--r-- | net/can/af_can.c | 299 |
1 files changed, 193 insertions, 106 deletions
diff --git a/net/can/af_can.c b/net/can/af_can.c index 702be5a2c95..ce82337521f 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -38,11 +38,10 @@ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH * DAMAGE. * - * Send feedback to <socketcan-users@lists.berlios.de> - * */ #include <linux/module.h> +#include <linux/stddef.h> #include <linux/init.h> #include <linux/kmod.h> #include <linux/slab.h> @@ -58,12 +57,14 @@ #include <linux/skbuff.h> #include <linux/can.h> #include <linux/can/core.h> +#include <linux/can/skb.h> +#include <linux/ratelimit.h> #include <net/net_namespace.h> #include <net/sock.h> #include "af_can.h" -static __initdata const char banner[] = KERN_INFO +static __initconst const char banner[] = KERN_INFO "can: controller area network core (" CAN_VERSION_STRING ")\n"; MODULE_DESCRIPTION("Controller Area Network PF_CAN core"); @@ -84,8 +85,8 @@ static DEFINE_SPINLOCK(can_rcvlists_lock); static struct kmem_cache *rcv_cache __read_mostly; /* table of registered CAN protocols */ -static struct can_proto *proto_tab[CAN_NPROTO] __read_mostly; -static DEFINE_SPINLOCK(proto_tab_lock); +static const struct can_proto *proto_tab[CAN_NPROTO] __read_mostly; +static DEFINE_MUTEX(proto_tab_lock); struct timer_list can_stattimer; /* timer for statistics update */ struct s_stats can_stats; /* packet statistics */ @@ -95,7 +96,7 @@ struct s_pstats can_pstats; /* receive list statistics */ * af_can socket functions */ -static int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) +int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) { struct sock *sk = sock->sk; @@ -108,17 +109,36 @@ static int can_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) return -ENOIOCTLCMD; } } +EXPORT_SYMBOL(can_ioctl); static void can_sock_destruct(struct sock *sk) { skb_queue_purge(&sk->sk_receive_queue); } +static const struct can_proto *can_get_proto(int protocol) +{ + const struct can_proto *cp; + + rcu_read_lock(); + cp = rcu_dereference(proto_tab[protocol]); + if (cp && !try_module_get(cp->prot->owner)) + cp = NULL; + rcu_read_unlock(); + + return cp; +} + +static inline void can_put_proto(const struct can_proto *cp) +{ + module_put(cp->prot->owner); +} + static int can_create(struct net *net, struct socket *sock, int protocol, int kern) { struct sock *sk; - struct can_proto *cp; + const struct can_proto *cp; int err = 0; sock->state = SS_UNCONNECTED; @@ -129,9 +149,12 @@ static int can_create(struct net *net, struct socket *sock, int protocol, if (!net_eq(net, &init_net)) return -EAFNOSUPPORT; + cp = can_get_proto(protocol); + #ifdef CONFIG_MODULES - /* try to load protocol module kernel is modular */ - if (!proto_tab[protocol]) { + if (!cp) { + /* try to load protocol module if kernel is modular */ + err = request_module("can-proto-%d", protocol); /* @@ -139,25 +162,21 @@ static int can_create(struct net *net, struct socket *sock, int protocol, * return the error code immediately. Below we will * return -EPROTONOSUPPORT */ - if (err && printk_ratelimit()) - printk(KERN_ERR "can: request_module " + if (err) + printk_ratelimited(KERN_ERR "can: request_module " "(can-proto-%d) failed.\n", protocol); + + cp = can_get_proto(protocol); } #endif - spin_lock(&proto_tab_lock); - cp = proto_tab[protocol]; - if (cp && !try_module_get(cp->prot->owner)) - cp = NULL; - spin_unlock(&proto_tab_lock); - /* check for available protocol and correct usage */ if (!cp) return -EPROTONOSUPPORT; if (cp->type != sock->type) { - err = -EPROTONOSUPPORT; + err = -EPROTOTYPE; goto errout; } @@ -182,7 +201,7 @@ static int can_create(struct net *net, struct socket *sock, int protocol, } errout: - module_put(cp->prot->owner); + can_put_proto(cp); return err; } @@ -203,30 +222,46 @@ static int can_create(struct net *net, struct socket *sock, int protocol, * -ENOBUFS on full driver queue (see net_xmit_errno()) * -ENOMEM when local loopback failed at calling skb_clone() * -EPERM when trying to send on a non-CAN interface + * -EMSGSIZE CAN frame size is bigger than CAN interface MTU * -EINVAL when the skb->data does not contain a valid CAN frame */ int can_send(struct sk_buff *skb, int loop) { struct sk_buff *newskb = NULL; - struct can_frame *cf = (struct can_frame *)skb->data; - int err; + struct canfd_frame *cfd = (struct canfd_frame *)skb->data; + int err = -EINVAL; + + if (skb->len == CAN_MTU) { + skb->protocol = htons(ETH_P_CAN); + if (unlikely(cfd->len > CAN_MAX_DLEN)) + goto inval_skb; + } else if (skb->len == CANFD_MTU) { + skb->protocol = htons(ETH_P_CANFD); + if (unlikely(cfd->len > CANFD_MAX_DLEN)) + goto inval_skb; + } else + goto inval_skb; - if (skb->len != sizeof(struct can_frame) || cf->can_dlc > 8) { - kfree_skb(skb); - return -EINVAL; + /* + * Make sure the CAN frame can pass the selected CAN netdevice. + * As structs can_frame and canfd_frame are similar, we can provide + * CAN FD frames to legacy CAN drivers as long as the length is <= 8 + */ + if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) { + err = -EMSGSIZE; + goto inval_skb; } - if (skb->dev->type != ARPHRD_CAN) { - kfree_skb(skb); - return -EPERM; + if (unlikely(skb->dev->type != ARPHRD_CAN)) { + err = -EPERM; + goto inval_skb; } - if (!(skb->dev->flags & IFF_UP)) { - kfree_skb(skb); - return -ENETDOWN; + if (unlikely(!(skb->dev->flags & IFF_UP))) { + err = -ENETDOWN; + goto inval_skb; } - skb->protocol = htons(ETH_P_CAN); skb_reset_network_header(skb); skb_reset_transport_header(skb); @@ -256,7 +291,7 @@ int can_send(struct sk_buff *skb, int loop) return -ENOMEM; } - newskb->sk = skb->sk; + can_skb_set_owner(newskb, skb->sk); newskb->ip_summed = CHECKSUM_UNNECESSARY; newskb->pkt_type = PACKET_BROADCAST; } @@ -283,6 +318,10 @@ int can_send(struct sk_buff *skb, int loop) can_stats.tx_frames_delta++; return 0; + +inval_skb: + kfree_skb(skb); + return err; } EXPORT_SYMBOL(can_send); @@ -299,6 +338,29 @@ static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev) } /** + * effhash - hash function for 29 bit CAN identifier reduction + * @can_id: 29 bit CAN identifier + * + * Description: + * To reduce the linear traversal in one linked list of _single_ EFF CAN + * frame subscriptions the 29 bit identifier is mapped to 10 bits. + * (see CAN_EFF_RCV_HASH_BITS definition) + * + * Return: + * Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask ) + */ +static unsigned int effhash(canid_t can_id) +{ + unsigned int hash; + + hash = can_id; + hash ^= can_id >> CAN_EFF_RCV_HASH_BITS; + hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS); + + return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1); +} + +/** * find_rcv_list - determine optimal filterlist inside device filter struct * @can_id: pointer to CAN identifier of a given can_filter * @mask: pointer to CAN mask of a given can_filter @@ -317,8 +379,8 @@ static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev) * relevant bits for the filter. * * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can - * filter for error frames (CAN_ERR_FLAG bit set in mask). For error frames - * there is a special filterlist and a special rx path filter handling. + * filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg + * frames there is a special filterlist and a special rx path filter handling. * * Return: * Pointer to optimal filterlist for the given can_id/mask pair. @@ -330,7 +392,7 @@ static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask, { canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */ - /* filter for error frames in extra filterlist */ + /* filter for error message frames in extra filterlist */ if (*mask & CAN_ERR_FLAG) { /* clear CAN_ERR_FLAG in filter entry */ *mask &= CAN_ERR_MASK; @@ -361,10 +423,8 @@ static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask, !(*can_id & CAN_RTR_FLAG)) { if (*can_id & CAN_EFF_FLAG) { - if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) { - /* RFC: a future use-case for hash-tables? */ - return &d->rx[RX_EFF]; - } + if (*mask == (CAN_EFF_MASK | CAN_EFF_RTR_FLAGS)) + return &d->rx_eff[effhash(*can_id)]; } else { if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS)) return &d->rx_sff[*can_id]; @@ -382,7 +442,7 @@ static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask, * @mask: CAN mask (see description) * @func: callback function on filter match * @data: returned parameter for callback function - * @ident: string for calling module indentification + * @ident: string for calling module identification * * Description: * Invokes the callback function with the received sk_buff and the given @@ -391,7 +451,7 @@ static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask, * <received_can_id> & mask == can_id & mask * * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can - * filter for error frames (CAN_ERR_FLAG bit set in mask). + * filter for error message frames (CAN_ERR_FLAG bit set in mask). * * The provided pointer to the sk_buff is guaranteed to be valid as long as * the callback function is running. The callback function must *not* free @@ -478,7 +538,6 @@ void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask, { struct receiver *r = NULL; struct hlist_head *rl; - struct hlist_node *next; struct dev_rcv_lists *d; if (dev && dev->type != ARPHRD_CAN) @@ -488,7 +547,7 @@ void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask, d = find_dev_rcv_lists(dev); if (!d) { - printk(KERN_ERR "BUG: receive list not found for " + pr_err("BUG: receive list not found for " "dev %s, id %03X, mask %03X\n", DNAME(dev), can_id, mask); goto out; @@ -502,23 +561,20 @@ void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask, * been registered before. */ - hlist_for_each_entry_rcu(r, next, rl, list) { + hlist_for_each_entry_rcu(r, rl, list) { if (r->can_id == can_id && r->mask == mask && r->func == func && r->data == data) break; } /* - * Check for bugs in CAN protocol implementations: - * If no matching list item was found, the list cursor variable next - * will be NULL, while r will point to the last item of the list. + * Check for bugs in CAN protocol implementations using af_can.c: + * 'r' will be NULL if no matching list item was found for removal. */ - if (!next) { - printk(KERN_ERR "BUG: receive list entry not found for " - "dev %s, id %03X, mask %03X\n", - DNAME(dev), can_id, mask); - r = NULL; + if (!r) { + WARN(1, "BUG: receive list entry not found for dev %s, " + "id %03X, mask %03X\n", DNAME(dev), can_id, mask); goto out; } @@ -552,7 +608,6 @@ static inline void deliver(struct sk_buff *skb, struct receiver *r) static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) { struct receiver *r; - struct hlist_node *n; int matches = 0; struct can_frame *cf = (struct can_frame *)skb->data; canid_t can_id = cf->can_id; @@ -561,8 +616,8 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) return 0; if (can_id & CAN_ERR_FLAG) { - /* check for error frame entries only */ - hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) { + /* check for error message frame entries only */ + hlist_for_each_entry_rcu(r, &d->rx[RX_ERR], list) { if (can_id & r->mask) { deliver(skb, r); matches++; @@ -572,13 +627,13 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) } /* check for unfiltered entries */ - hlist_for_each_entry_rcu(r, n, &d->rx[RX_ALL], list) { + hlist_for_each_entry_rcu(r, &d->rx[RX_ALL], list) { deliver(skb, r); matches++; } /* check for can_id/mask entries */ - hlist_for_each_entry_rcu(r, n, &d->rx[RX_FIL], list) { + hlist_for_each_entry_rcu(r, &d->rx[RX_FIL], list) { if ((can_id & r->mask) == r->can_id) { deliver(skb, r); matches++; @@ -586,7 +641,7 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) } /* check for inverted can_id/mask entries */ - hlist_for_each_entry_rcu(r, n, &d->rx[RX_INV], list) { + hlist_for_each_entry_rcu(r, &d->rx[RX_INV], list) { if ((can_id & r->mask) != r->can_id) { deliver(skb, r); matches++; @@ -598,7 +653,7 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) return matches; if (can_id & CAN_EFF_FLAG) { - hlist_for_each_entry_rcu(r, n, &d->rx[RX_EFF], list) { + hlist_for_each_entry_rcu(r, &d->rx_eff[effhash(can_id)], list) { if (r->can_id == can_id) { deliver(skb, r); matches++; @@ -606,7 +661,7 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) } } else { can_id &= CAN_SFF_MASK; - hlist_for_each_entry_rcu(r, n, &d->rx_sff[can_id], list) { + hlist_for_each_entry_rcu(r, &d->rx_sff[can_id], list) { deliver(skb, r); matches++; } @@ -615,24 +670,11 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb) return matches; } -static int can_rcv(struct sk_buff *skb, struct net_device *dev, - struct packet_type *pt, struct net_device *orig_dev) +static void can_receive(struct sk_buff *skb, struct net_device *dev) { struct dev_rcv_lists *d; - struct can_frame *cf = (struct can_frame *)skb->data; int matches; - if (!net_eq(dev_net(dev), &init_net)) - goto drop; - - if (WARN_ONCE(dev->type != ARPHRD_CAN || - skb->len != sizeof(struct can_frame) || - cf->can_dlc > 8, - "PF_CAN: dropped non conform skbuf: " - "dev type %d, len %d, can_dlc %d\n", - dev->type, skb->len, cf->can_dlc)) - goto drop; - /* update statistics */ can_stats.rx_frames++; can_stats.rx_frames_delta++; @@ -656,7 +698,49 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev, can_stats.matches++; can_stats.matches_delta++; } +} + +static int can_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, struct net_device *orig_dev) +{ + struct canfd_frame *cfd = (struct canfd_frame *)skb->data; + + if (unlikely(!net_eq(dev_net(dev), &init_net))) + goto drop; + if (WARN_ONCE(dev->type != ARPHRD_CAN || + skb->len != CAN_MTU || + cfd->len > CAN_MAX_DLEN, + "PF_CAN: dropped non conform CAN skbuf: " + "dev type %d, len %d, datalen %d\n", + dev->type, skb->len, cfd->len)) + goto drop; + + can_receive(skb, dev); + return NET_RX_SUCCESS; + +drop: + kfree_skb(skb); + return NET_RX_DROP; +} + +static int canfd_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pt, struct net_device *orig_dev) +{ + struct canfd_frame *cfd = (struct canfd_frame *)skb->data; + + if (unlikely(!net_eq(dev_net(dev), &init_net))) + goto drop; + + if (WARN_ONCE(dev->type != ARPHRD_CAN || + skb->len != CANFD_MTU || + cfd->len > CANFD_MAX_DLEN, + "PF_CAN: dropped non conform CAN FD skbuf: " + "dev type %d, len %d, datalen %d\n", + dev->type, skb->len, cfd->len)) + goto drop; + + can_receive(skb, dev); return NET_RX_SUCCESS; drop: @@ -678,14 +762,13 @@ drop: * -EBUSY protocol already in use * -ENOBUF if proto_register() fails */ -int can_proto_register(struct can_proto *cp) +int can_proto_register(const struct can_proto *cp) { int proto = cp->protocol; int err = 0; if (proto < 0 || proto >= CAN_NPROTO) { - printk(KERN_ERR "can: protocol number %d out of range\n", - proto); + pr_err("can: protocol number %d out of range\n", proto); return -EINVAL; } @@ -693,19 +776,15 @@ int can_proto_register(struct can_proto *cp) if (err < 0) return err; - spin_lock(&proto_tab_lock); + mutex_lock(&proto_tab_lock); + if (proto_tab[proto]) { - printk(KERN_ERR "can: protocol %d already registered\n", - proto); + pr_err("can: protocol %d already registered\n", proto); err = -EBUSY; - } else { - proto_tab[proto] = cp; + } else + RCU_INIT_POINTER(proto_tab[proto], cp); - /* use generic ioctl function if not defined by module */ - if (!cp->ops->ioctl) - cp->ops->ioctl = can_ioctl; - } - spin_unlock(&proto_tab_lock); + mutex_unlock(&proto_tab_lock); if (err < 0) proto_unregister(cp->prot); @@ -718,17 +797,16 @@ EXPORT_SYMBOL(can_proto_register); * can_proto_unregister - unregister CAN transport protocol * @cp: pointer to CAN protocol structure */ -void can_proto_unregister(struct can_proto *cp) +void can_proto_unregister(const struct can_proto *cp) { int proto = cp->protocol; - spin_lock(&proto_tab_lock); - if (!proto_tab[proto]) { - printk(KERN_ERR "BUG: can: protocol %d is not registered\n", - proto); - } - proto_tab[proto] = NULL; - spin_unlock(&proto_tab_lock); + mutex_lock(&proto_tab_lock); + BUG_ON(proto_tab[proto] != cp); + RCU_INIT_POINTER(proto_tab[proto], NULL); + mutex_unlock(&proto_tab_lock); + + synchronize_rcu(); proto_unregister(cp->prot); } @@ -738,9 +816,9 @@ EXPORT_SYMBOL(can_proto_unregister); * af_can notifier to create/remove CAN netdevice specific structs */ static int can_notifier(struct notifier_block *nb, unsigned long msg, - void *data) + void *ptr) { - struct net_device *dev = (struct net_device *)data; + struct net_device *dev = netdev_notifier_info_to_dev(ptr); struct dev_rcv_lists *d; if (!net_eq(dev_net(dev), &init_net)) @@ -755,11 +833,8 @@ static int can_notifier(struct notifier_block *nb, unsigned long msg, /* create new dev_rcv_lists for this device */ d = kzalloc(sizeof(*d), GFP_KERNEL); - if (!d) { - printk(KERN_ERR - "can: allocation of receive list failed\n"); + if (!d) return NOTIFY_DONE; - } BUG_ON(dev->ml_priv); dev->ml_priv = d; @@ -777,8 +852,8 @@ static int can_notifier(struct notifier_block *nb, unsigned long msg, dev->ml_priv = NULL; } } else - printk(KERN_ERR "can: notifier: receive list not " - "found for dev %s\n", dev->name); + pr_err("can: notifier: receive list not found for dev " + "%s\n", dev->name); spin_unlock(&can_rcvlists_lock); @@ -794,10 +869,14 @@ static int can_notifier(struct notifier_block *nb, unsigned long msg, static struct packet_type can_packet __read_mostly = { .type = cpu_to_be16(ETH_P_CAN), - .dev = NULL, .func = can_rcv, }; +static struct packet_type canfd_packet __read_mostly = { + .type = cpu_to_be16(ETH_P_CANFD), + .func = canfd_rcv, +}; + static const struct net_proto_family can_family_ops = { .family = PF_CAN, .create = can_create, @@ -811,6 +890,12 @@ static struct notifier_block can_netdev_notifier __read_mostly = { static __init int can_init(void) { + /* check for correct padding to be able to use the structs similarly */ + BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) != + offsetof(struct canfd_frame, len) || + offsetof(struct can_frame, data) != + offsetof(struct canfd_frame, data)); + printk(banner); memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list)); @@ -833,6 +918,7 @@ static __init int can_init(void) sock_register(&can_family_ops); register_netdevice_notifier(&can_netdev_notifier); dev_add_pack(&can_packet); + dev_add_pack(&canfd_packet); return 0; } @@ -842,11 +928,12 @@ static __exit void can_exit(void) struct net_device *dev; if (stats_timer) - del_timer(&can_stattimer); + del_timer_sync(&can_stattimer); can_remove_proc(); /* protocol unregister */ + dev_remove_pack(&canfd_packet); dev_remove_pack(&can_packet); unregister_netdevice_notifier(&can_netdev_notifier); sock_unregister(PF_CAN); @@ -854,7 +941,7 @@ static __exit void can_exit(void) /* remove created dev_rcv_lists from still registered CAN devices */ rcu_read_lock(); for_each_netdev_rcu(&init_net, dev) { - if (dev->type == ARPHRD_CAN && dev->ml_priv){ + if (dev->type == ARPHRD_CAN && dev->ml_priv) { struct dev_rcv_lists *d = dev->ml_priv; |
