diff options
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 284 |
1 files changed, 189 insertions, 95 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 8c6c08446556..30a1603a7225 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -151,6 +151,7 @@ #include <linux/prandom.h> #include <linux/once_lite.h> +#include "dev.h" #include "net-sysfs.h" @@ -396,16 +397,18 @@ static void list_netdevice(struct net_device *dev) /* Device list removal * caller must respect a RCU grace period before freeing/reusing dev */ -static void unlist_netdevice(struct net_device *dev) +static void unlist_netdevice(struct net_device *dev, bool lock) { ASSERT_RTNL(); /* Unlink dev from the device chain */ - write_lock(&dev_base_lock); + if (lock) + write_lock(&dev_base_lock); list_del_rcu(&dev->dev_list); netdev_name_node_del(dev->name_node); hlist_del_rcu(&dev->index_hlist); - write_unlock(&dev_base_lock); + if (lock) + write_unlock(&dev_base_lock); dev_base_seq_inc(dev_net(dev)); } @@ -681,11 +684,11 @@ int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr, const struct net_device *last_dev; struct net_device_path_ctx ctx = { .dev = dev, - .daddr = daddr, }; struct net_device_path *path; int ret = 0; + memcpy(ctx.daddr, daddr, sizeof(ctx.daddr)); stack->num_paths = 0; while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) { last_dev = ctx.dev; @@ -701,6 +704,10 @@ int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr, if (WARN_ON_ONCE(last_dev == ctx.dev)) return -1; } + + if (!ctx.dev) + return ret; + path = dev_fwd_path(stack); if (!path) return -1; @@ -2988,6 +2995,52 @@ undo_rx: EXPORT_SYMBOL(netif_set_real_num_queues); /** + * netif_set_tso_max_size() - set the max size of TSO frames supported + * @dev: netdev to update + * @size: max skb->len of a TSO frame + * + * Set the limit on the size of TSO super-frames the device can handle. + * Unless explicitly set the stack will assume the value of + * %GSO_LEGACY_MAX_SIZE. + */ +void netif_set_tso_max_size(struct net_device *dev, unsigned int size) +{ + dev->tso_max_size = min(GSO_MAX_SIZE, size); + if (size < READ_ONCE(dev->gso_max_size)) + netif_set_gso_max_size(dev, size); +} +EXPORT_SYMBOL(netif_set_tso_max_size); + +/** + * netif_set_tso_max_segs() - set the max number of segs supported for TSO + * @dev: netdev to update + * @segs: max number of TCP segments + * + * Set the limit on the number of TCP segments the device can generate from + * a single TSO super-frame. + * Unless explicitly set the stack will assume the value of %GSO_MAX_SEGS. + */ +void netif_set_tso_max_segs(struct net_device *dev, unsigned int segs) +{ + dev->tso_max_segs = segs; + if (segs < READ_ONCE(dev->gso_max_segs)) + netif_set_gso_max_segs(dev, segs); +} +EXPORT_SYMBOL(netif_set_tso_max_segs); + +/** + * netif_inherit_tso_max() - copy all TSO limits from a lower device to an upper + * @to: netdev to update + * @from: netdev from which to copy the limits + */ +void netif_inherit_tso_max(struct net_device *to, const struct net_device *from) +{ + netif_set_tso_max_size(to, from->tso_max_size); + netif_set_tso_max_segs(to, from->tso_max_segs); +} +EXPORT_SYMBOL(netif_inherit_tso_max); + +/** * netif_get_num_default_rss_queues - default number of RSS queues * * Default value is the number of physical cores if there are only 1 or 2, or @@ -3215,12 +3268,18 @@ int skb_checksum_help(struct sk_buff *skb) } offset = skb_checksum_start_offset(skb); - BUG_ON(offset >= skb_headlen(skb)); + ret = -EINVAL; + if (WARN_ON_ONCE(offset >= skb_headlen(skb))) { + DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false); + goto out; + } csum = skb_checksum(skb, offset, skb->len - offset, 0); offset += skb->csum_offset; - BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb)); - + if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) { + DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false); + goto out; + } ret = skb_ensure_writable(skb, offset + sizeof(__sum16)); if (ret) goto out; @@ -3527,7 +3586,6 @@ static int xmit_one(struct sk_buff *skb, struct net_device *dev, dev_queue_xmit_nit(skb, dev); len = skb->len; - PRANDOM_ADD_NOISE(skb, dev, txq, len + jiffies); trace_net_dev_start_xmit(skb, dev); rc = netdev_start_xmit(skb, dev, txq, more); trace_net_dev_xmit(skb, rc, dev, len); @@ -3920,6 +3978,25 @@ sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev) return skb; } + +static struct netdev_queue * +netdev_tx_queue_mapping(struct net_device *dev, struct sk_buff *skb) +{ + int qm = skb_get_queue_mapping(skb); + + return netdev_get_tx_queue(dev, netdev_cap_txqueue(dev, qm)); +} + +static bool netdev_xmit_txqueue_skipped(void) +{ + return __this_cpu_read(softnet_data.xmit.skip_txqueue); +} + +void netdev_xmit_skip_txqueue(bool skip) +{ + __this_cpu_write(softnet_data.xmit.skip_txqueue, skip); +} +EXPORT_SYMBOL_GPL(netdev_xmit_skip_txqueue); #endif /* CONFIG_NET_EGRESS */ #ifdef CONFIG_XPS @@ -4062,35 +4139,30 @@ struct netdev_queue *netdev_core_pick_tx(struct net_device *dev, } /** - * __dev_queue_xmit - transmit a buffer - * @skb: buffer to transmit - * @sb_dev: suboordinate device used for L2 forwarding offload + * __dev_queue_xmit() - transmit a buffer + * @skb: buffer to transmit + * @sb_dev: suboordinate device used for L2 forwarding offload * - * Queue a buffer for transmission to a network device. The caller must - * have set the device and priority and built the buffer before calling - * this function. The function can be called from an interrupt. + * Queue a buffer for transmission to a network device. The caller must + * have set the device and priority and built the buffer before calling + * this function. The function can be called from an interrupt. * - * A negative errno code is returned on a failure. A success does not - * guarantee the frame will be transmitted as it may be dropped due - * to congestion or traffic shaping. + * When calling this method, interrupts MUST be enabled. This is because + * the BH enable code must have IRQs enabled so that it will not deadlock. * - * ----------------------------------------------------------------------------------- - * I notice this method can also return errors from the queue disciplines, - * including NET_XMIT_DROP, which is a positive value. So, errors can also - * be positive. + * Regardless of the return value, the skb is consumed, so it is currently + * difficult to retry a send to this method. (You can bump the ref count + * before sending to hold a reference for retry if you are careful.) * - * Regardless of the return value, the skb is consumed, so it is currently - * difficult to retry a send to this method. (You can bump the ref count - * before sending to hold a reference for retry if you are careful.) - * - * When calling this method, interrupts MUST be enabled. This is because - * the BH enable code must have IRQs enabled so that it will not deadlock. - * --BLG + * Return: + * * 0 - buffer successfully transmitted + * * positive qdisc return code - NET_XMIT_DROP etc. + * * negative errno - other errors */ -static int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev) +int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev) { struct net_device *dev = skb->dev; - struct netdev_queue *txq; + struct netdev_queue *txq = NULL; struct Qdisc *q; int rc = -ENOMEM; bool again = false; @@ -4118,11 +4190,17 @@ static int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev) if (!skb) goto out; } + + netdev_xmit_skip_txqueue(false); + nf_skip_egress(skb, true); skb = sch_handle_egress(skb, &rc, dev); if (!skb) goto out; nf_skip_egress(skb, false); + + if (netdev_xmit_txqueue_skipped()) + txq = netdev_tx_queue_mapping(dev, skb); } #endif /* If device/qdisc don't need skb->dst, release it right now while @@ -4133,7 +4211,9 @@ static int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev) else skb_dst_force(skb); - txq = netdev_core_pick_tx(dev, skb, sb_dev); + if (!txq) + txq = netdev_core_pick_tx(dev, skb, sb_dev); + q = rcu_dereference_bh(txq->qdisc); trace_net_dev_queue(skb); @@ -4168,7 +4248,6 @@ static int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev) if (!skb) goto out; - PRANDOM_ADD_NOISE(skb, dev, txq, jiffies); HARD_TX_LOCK(dev, txq, cpu); if (!netif_xmit_stopped(txq)) { @@ -4203,18 +4282,7 @@ out: rcu_read_unlock_bh(); return rc; } - -int dev_queue_xmit(struct sk_buff *skb) -{ - return __dev_queue_xmit(skb, NULL); -} -EXPORT_SYMBOL(dev_queue_xmit); - -int dev_queue_xmit_accel(struct sk_buff *skb, struct net_device *sb_dev) -{ - return __dev_queue_xmit(skb, sb_dev); -} -EXPORT_SYMBOL(dev_queue_xmit_accel); +EXPORT_SYMBOL(__dev_queue_xmit); int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id) { @@ -4234,7 +4302,6 @@ int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id) skb_set_queue_mapping(skb, queue_id); txq = skb_get_tx_queue(dev, skb); - PRANDOM_ADD_NOISE(skb, dev, txq, jiffies); local_bh_disable(); @@ -4262,6 +4329,7 @@ int netdev_max_backlog __read_mostly = 1000; EXPORT_SYMBOL(netdev_max_backlog); int netdev_tstamp_prequeue __read_mostly = 1; +unsigned int sysctl_skb_defer_max __read_mostly = 64; int netdev_budget __read_mostly = 300; /* Must be at least 2 jiffes to guarantee 1 jiffy timeout */ unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ; @@ -4513,6 +4581,15 @@ static void rps_trigger_softirq(void *data) #endif /* CONFIG_RPS */ +/* Called from hardirq (IPI) context */ +static void trigger_rx_softirq(void *data) +{ + struct softnet_data *sd = data; + + __raise_softirq_irqoff(NET_RX_SOFTIRQ); + smp_store_release(&sd->defer_ipi_scheduled, 0); +} + /* * Check if this softnet_data structure is another cpu one * If yes, queue it to our IPI list and return 1 @@ -4786,7 +4863,10 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb, } /* When doing generic XDP we have to bypass the qdisc layer and the - * network taps in order to match in-driver-XDP behavior. + * network taps in order to match in-driver-XDP behavior. This also means + * that XDP packets are able to starve other packets going through a qdisc, + * and DDOS attacks will be more effective. In-driver-XDP use dedicated TX + * queues, so they do not have this starvation issue. */ void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog) { @@ -4798,7 +4878,7 @@ void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog) txq = netdev_core_pick_tx(dev, skb, NULL); cpu = smp_processor_id(); HARD_TX_LOCK(dev, txq, cpu); - if (!netif_xmit_stopped(txq)) { + if (!netif_xmit_frozen_or_drv_stopped(txq)) { rc = netdev_start_xmit(skb, dev, txq, 0); if (dev_xmit_complete(rc)) free_skb = false; @@ -4806,6 +4886,7 @@ void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog) HARD_TX_UNLOCK(dev, txq); if (free_skb) { trace_xdp_exception(dev, xdp_prog, XDP_TX); + dev_core_stats_tx_dropped_inc(dev); kfree_skb(skb); } } @@ -5370,13 +5451,11 @@ check_vlan_id: *ppt_prev = pt_prev; } else { drop: - if (!deliver_exact) { + if (!deliver_exact) dev_core_stats_rx_dropped_inc(skb->dev); - kfree_skb_reason(skb, SKB_DROP_REASON_PTYPE_ABSENT); - } else { + else dev_core_stats_rx_nohandler_inc(skb->dev); - kfree_skb(skb); - } + kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO); /* Jamal, now you will not able to escape explaining * me how you were going to use this. :-) */ @@ -6278,8 +6357,8 @@ int dev_set_threaded(struct net_device *dev, bool threaded) } EXPORT_SYMBOL(dev_set_threaded); -void netif_napi_add(struct net_device *dev, struct napi_struct *napi, - int (*poll)(struct napi_struct *, int), int weight) +void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi, + int (*poll)(struct napi_struct *, int), int weight) { if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state))) return; @@ -6312,7 +6391,7 @@ void netif_napi_add(struct net_device *dev, struct napi_struct *napi, if (dev->threaded && napi_kthread_create(napi)) dev->threaded = 0; } -EXPORT_SYMBOL(netif_napi_add); +EXPORT_SYMBOL(netif_napi_add_weight); void napi_disable(struct napi_struct *n) { @@ -6541,6 +6620,28 @@ static int napi_threaded_poll(void *data) return 0; } +static void skb_defer_free_flush(struct softnet_data *sd) +{ + struct sk_buff *skb, *next; + unsigned long flags; + + /* Paired with WRITE_ONCE() in skb_attempt_defer_free() */ + if (!READ_ONCE(sd->defer_list)) + return; + + spin_lock_irqsave(&sd->defer_lock, flags); + skb = sd->defer_list; + sd->defer_list = NULL; + sd->defer_count = 0; + spin_unlock_irqrestore(&sd->defer_lock, flags); + + while (skb != NULL) { + next = skb->next; + napi_consume_skb(skb, 1); + skb = next; + } +} + static __latent_entropy void net_rx_action(struct softirq_action *h) { struct softnet_data *sd = this_cpu_ptr(&softnet_data); @@ -6557,9 +6658,11 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) for (;;) { struct napi_struct *n; + skb_defer_free_flush(sd); + if (list_empty(&list)) { if (!sd_has_rps_ipi_waiting(sd) && list_empty(&repoll)) - return; + goto end; break; } @@ -6586,6 +6689,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) __raise_softirq_irqoff(NET_RX_SOFTIRQ); net_rps_action_and_irq_enable(sd); +end:; } struct netdev_adjacent { @@ -8641,7 +8745,6 @@ void dev_set_group(struct net_device *dev, int new_group) { dev->group = new_group; } -EXPORT_SYMBOL(dev_set_group); /** * dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR. @@ -8756,7 +8859,6 @@ int dev_change_carrier(struct net_device *dev, bool new_carrier) return -ENODEV; return ops->ndo_change_carrier(dev, new_carrier); } -EXPORT_SYMBOL(dev_change_carrier); /** * dev_get_phys_port_id - Get device physical port ID @@ -8774,7 +8876,6 @@ int dev_get_phys_port_id(struct net_device *dev, return -EOPNOTSUPP; return ops->ndo_get_phys_port_id(dev, ppid); } -EXPORT_SYMBOL(dev_get_phys_port_id); /** * dev_get_phys_port_name - Get device physical port name @@ -8797,7 +8898,6 @@ int dev_get_phys_port_name(struct net_device *dev, } return devlink_compat_phys_port_name_get(dev, name, len); } -EXPORT_SYMBOL(dev_get_phys_port_name); /** * dev_get_port_parent_id - Get the device's port parent identifier @@ -8879,7 +8979,6 @@ int dev_change_proto_down(struct net_device *dev, bool proto_down) dev->proto_down = proto_down; return 0; } -EXPORT_SYMBOL(dev_change_proto_down); /** * dev_change_proto_down_reason - proto down reason @@ -8904,7 +9003,6 @@ void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask, } } } -EXPORT_SYMBOL(dev_change_proto_down_reason); struct bpf_xdp_link { struct bpf_link link; @@ -9431,7 +9529,7 @@ static int dev_new_index(struct net *net) } /* Delayed registration/unregisteration */ -static LIST_HEAD(net_todo_list); +LIST_HEAD(net_todo_list); DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq); static void net_set_todo(struct net_device *dev) @@ -9838,22 +9936,14 @@ void netif_tx_stop_all_queues(struct net_device *dev) EXPORT_SYMBOL(netif_tx_stop_all_queues); /** - * register_netdevice - register a network device - * @dev: device to register - * - * Take a completed network device structure and add it to the kernel - * interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier - * chain. 0 is returned on success. A negative errno code is returned - * on a failure to set up the device, or if the name is a duplicate. - * - * Callers must hold the rtnl semaphore. You may want - * register_netdev() instead of this. + * register_netdevice() - register a network device + * @dev: device to register * - * BUGS: - * The locking appears insufficient to guarantee two parallel registers - * will not get the same name. + * Take a prepared network device structure and make it externally accessible. + * A %NETDEV_REGISTER message is sent to the netdev notifier chain. + * Callers must hold the rtnl lock - you may want register_netdev() + * instead of this. */ - int register_netdevice(struct net_device *dev) { int ret; @@ -9959,11 +10049,11 @@ int register_netdevice(struct net_device *dev) goto err_uninit; ret = netdev_register_kobject(dev); - if (ret) { - dev->reg_state = NETREG_UNREGISTERED; + write_lock(&dev_base_lock); + dev->reg_state = ret ? NETREG_UNREGISTERED : NETREG_REGISTERED; + write_unlock(&dev_base_lock); + if (ret) goto err_uninit; - } - dev->reg_state = NETREG_REGISTERED; __netdev_update_features(dev); @@ -10245,7 +10335,9 @@ void netdev_run_todo(void) continue; } + write_lock(&dev_base_lock); dev->reg_state = NETREG_UNREGISTERED; + write_unlock(&dev_base_lock); linkwatch_forget_dev(dev); } @@ -10304,7 +10396,7 @@ void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64, } EXPORT_SYMBOL(netdev_stats_to_stats64); -struct net_device_core_stats *netdev_core_stats_alloc(struct net_device *dev) +struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_device *dev) { struct net_device_core_stats __percpu *p; @@ -10315,11 +10407,7 @@ struct net_device_core_stats *netdev_core_stats_alloc(struct net_device *dev) free_percpu(p); /* This READ_ONCE() pairs with the cmpxchg() above */ - p = READ_ONCE(dev->core_stats); - if (!p) - return NULL; - - return this_cpu_ptr(p); + return READ_ONCE(dev->core_stats); } EXPORT_SYMBOL(netdev_core_stats_alloc); @@ -10356,9 +10444,10 @@ struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev, for_each_possible_cpu(i) { core_stats = per_cpu_ptr(p, i); - storage->rx_dropped += local_read(&core_stats->rx_dropped); - storage->tx_dropped += local_read(&core_stats->tx_dropped); - storage->rx_nohandler += local_read(&core_stats->rx_nohandler); + storage->rx_dropped += READ_ONCE(core_stats->rx_dropped); + storage->tx_dropped += READ_ONCE(core_stats->tx_dropped); + storage->rx_nohandler += READ_ONCE(core_stats->rx_nohandler); + storage->rx_otherhost_dropped += READ_ONCE(core_stats->rx_otherhost_dropped); } } return storage; @@ -10517,9 +10606,11 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name, dev_net_set(dev, &init_net); - dev->gso_max_size = GSO_MAX_SIZE; + dev->gso_max_size = GSO_LEGACY_MAX_SIZE; dev->gso_max_segs = GSO_MAX_SEGS; - dev->gro_max_size = GRO_MAX_SIZE; + dev->gro_max_size = GRO_LEGACY_MAX_SIZE; + dev->tso_max_size = TSO_LEGACY_MAX_SIZE; + dev->tso_max_segs = TSO_MAX_SEGS; dev->upper_level = 1; dev->lower_level = 1; #ifdef CONFIG_LOCKDEP @@ -10727,9 +10818,10 @@ void unregister_netdevice_many(struct list_head *head) list_for_each_entry(dev, head, unreg_list) { /* And unlink it from device chain. */ - unlist_netdevice(dev); - + write_lock(&dev_base_lock); + unlist_netdevice(dev, false); dev->reg_state = NETREG_UNREGISTERING; + write_unlock(&dev_base_lock); } flush_all_backlogs(); @@ -10876,7 +10968,7 @@ int __dev_change_net_namespace(struct net_device *dev, struct net *net, dev_close(dev); /* And unlink it from device chain */ - unlist_netdevice(dev); + unlist_netdevice(dev, true); synchronize_net(); @@ -11301,6 +11393,8 @@ static int __init net_dev_init(void) INIT_CSD(&sd->csd, rps_trigger_softirq, sd); sd->cpu = i; #endif + INIT_CSD(&sd->defer_csd, trigger_rx_softirq, sd); + spin_lock_init(&sd->defer_lock); init_gro_hash(&sd->backlog); sd->backlog.poll = process_backlog; |