// SPDX-License-Identifier: GPL-2.0-only /* * Monitoring code for network dropped packet alerts * * Copyright (C) 2009 Neil Horman <nhorman@tuxdriver.com> */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/netdevice.h> #include <linux/etherdevice.h> #include <linux/string.h> #include <linux/if_arp.h> #include <linux/inetdevice.h> #include <linux/inet.h> #include <linux/interrupt.h> #include <linux/netpoll.h> #include <linux/sched.h> #include <linux/delay.h> #include <linux/types.h> #include <linux/workqueue.h> #include <linux/netlink.h> #include <linux/net_dropmon.h> #include <linux/percpu.h> #include <linux/timer.h> #include <linux/bitops.h> #include <linux/slab.h> #include <linux/module.h> #include <net/genetlink.h> #include <net/netevent.h> #include <net/flow_offload.h> #include <net/devlink.h> #include <trace/events/skb.h> #include <trace/events/napi.h> #include <trace/events/devlink.h> #include <asm/unaligned.h> #define TRACE_ON 1 #define TRACE_OFF 0 /* * Globals, our netlink socket pointer * and the work handle that will send up * netlink alerts */ static int trace_state = TRACE_OFF; static bool monitor_hw; /* net_dm_mutex * * An overall lock guarding every operation coming from userspace. * It also guards the global 'hw_stats_list' list. */ static DEFINE_MUTEX(net_dm_mutex); struct net_dm_stats { <------>u64 dropped; <------>struct u64_stats_sync syncp; }; #define NET_DM_MAX_HW_TRAP_NAME_LEN 40 struct net_dm_hw_entry { <------>char trap_name[NET_DM_MAX_HW_TRAP_NAME_LEN]; <------>u32 count; }; struct net_dm_hw_entries { <------>u32 num_entries; <------>struct net_dm_hw_entry entries[]; }; struct per_cpu_dm_data { <------>spinlock_t lock; /* Protects 'skb', 'hw_entries' and <------><------><------><------><------> * 'send_timer' <------><------><------><------><------> */ <------>union { <------><------>struct sk_buff *skb; <------><------>struct net_dm_hw_entries *hw_entries; <------>}; <------>struct sk_buff_head drop_queue; <------>struct work_struct dm_alert_work; <------>struct timer_list send_timer; <------>struct net_dm_stats stats; }; struct dm_hw_stat_delta { <------>struct net_device *dev; <------>unsigned long last_rx; <------>struct list_head list; <------>struct rcu_head rcu; <------>unsigned long last_drop_val; }; static struct genl_family net_drop_monitor_family; static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data); static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_hw_cpu_data); static int dm_hit_limit = 64; static int dm_delay = 1; static unsigned long dm_hw_check_delta = 2*HZ; static LIST_HEAD(hw_stats_list); static enum net_dm_alert_mode net_dm_alert_mode = NET_DM_ALERT_MODE_SUMMARY; static u32 net_dm_trunc_len; static u32 net_dm_queue_len = 1000; struct net_dm_alert_ops { <------>void (*kfree_skb_probe)(void *ignore, struct sk_buff *skb, <------><------><------><------>void *location); <------>void (*napi_poll_probe)(void *ignore, struct napi_struct *napi, <------><------><------><------>int work, int budget); <------>void (*work_item_func)(struct work_struct *work); <------>void (*hw_work_item_func)(struct work_struct *work); <------>void (*hw_trap_probe)(void *ignore, const struct devlink *devlink, <------><------><------> struct sk_buff *skb, <------><------><------> const struct devlink_trap_metadata *metadata); }; struct net_dm_skb_cb { <------>union { <------><------>struct devlink_trap_metadata *hw_metadata; <------><------>void *pc; <------>}; }; #define NET_DM_SKB_CB(__skb) ((struct net_dm_skb_cb *)&((__skb)->cb[0])) static struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data) { <------>size_t al; <------>struct net_dm_alert_msg *msg; <------>struct nlattr *nla; <------>struct sk_buff *skb; <------>unsigned long flags; <------>void *msg_header; <------>al = sizeof(struct net_dm_alert_msg); <------>al += dm_hit_limit * sizeof(struct net_dm_drop_point); <------>al += sizeof(struct nlattr); <------>skb = genlmsg_new(al, GFP_KERNEL); <------>if (!skb) <------><------>goto err; <------>msg_header = genlmsg_put(skb, 0, 0, &net_drop_monitor_family, <------><------><------><------> 0, NET_DM_CMD_ALERT); <------>if (!msg_header) { <------><------>nlmsg_free(skb); <------><------>skb = NULL; <------><------>goto err; <------>} <------>nla = nla_reserve(skb, NLA_UNSPEC, <------><------><------> sizeof(struct net_dm_alert_msg)); <------>if (!nla) { <------><------>nlmsg_free(skb); <------><------>skb = NULL; <------><------>goto err; <------>} <------>msg = nla_data(nla); <------>memset(msg, 0, al); <------>goto out; err: <------>mod_timer(&data->send_timer, jiffies + HZ / 10); out: <------>spin_lock_irqsave(&data->lock, flags); <------>swap(data->skb, skb); <------>spin_unlock_irqrestore(&data->lock, flags); <------>if (skb) { <------><------>struct nlmsghdr *nlh = (struct nlmsghdr *)skb->data; <------><------>struct genlmsghdr *gnlh = (struct genlmsghdr *)nlmsg_data(nlh); <------><------>genlmsg_end(skb, genlmsg_data(gnlh)); <------>} <------>return skb; } static const struct genl_multicast_group dropmon_mcgrps[] = { <------>{ .name = "events", }, }; static void send_dm_alert(struct work_struct *work) { <------>struct sk_buff *skb; <------>struct per_cpu_dm_data *data; <------>data = container_of(work, struct per_cpu_dm_data, dm_alert_work); <------>skb = reset_per_cpu_data(data); <------>if (skb) <------><------>genlmsg_multicast(&net_drop_monitor_family, skb, 0, <------><------><------><------> 0, GFP_KERNEL); } /* * This is the timer function to delay the sending of an alert * in the event that more drops will arrive during the * hysteresis period. */ static void sched_send_work(struct timer_list *t) { <------>struct per_cpu_dm_data *data = from_timer(data, t, send_timer); <------>schedule_work(&data->dm_alert_work); } static void trace_drop_common(struct sk_buff *skb, void *location) { <------>struct net_dm_alert_msg *msg; <------>struct net_dm_drop_point *point; <------>struct nlmsghdr *nlh; <------>struct nlattr *nla; <------>int i; <------>struct sk_buff *dskb; <------>struct per_cpu_dm_data *data; <------>unsigned long flags; <------>local_irq_save(flags); <------>data = this_cpu_ptr(&dm_cpu_data); <------>spin_lock(&data->lock); <------>dskb = data->skb; <------>if (!dskb) <------><------>goto out; <------>nlh = (struct nlmsghdr *)dskb->data; <------>nla = genlmsg_data(nlmsg_data(nlh)); <------>msg = nla_data(nla); <------>point = msg->points; <------>for (i = 0; i < msg->entries; i++) { <------><------>if (!memcmp(&location, &point->pc, sizeof(void *))) { <------><------><------>point->count++; <------><------><------>goto out; <------><------>} <------><------>point++; <------>} <------>if (msg->entries == dm_hit_limit) <------><------>goto out; <------>/* <------> * We need to create a new entry <------> */ <------>__nla_reserve_nohdr(dskb, sizeof(struct net_dm_drop_point)); <------>nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point)); <------>memcpy(point->pc, &location, sizeof(void *)); <------>point->count = 1; <------>msg->entries++; <------>if (!timer_pending(&data->send_timer)) { <------><------>data->send_timer.expires = jiffies + dm_delay * HZ; <------><------>add_timer(&data->send_timer); <------>} out: <------>spin_unlock_irqrestore(&data->lock, flags); } static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb, void *location) { <------>trace_drop_common(skb, location); } static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi, <------><------><------><------>int work, int budget) { <------>struct dm_hw_stat_delta *new_stat; <------>/* <------> * Don't check napi structures with no associated device <------> */ <------>if (!napi->dev) <------><------>return; <------>rcu_read_lock(); <------>list_for_each_entry_rcu(new_stat, &hw_stats_list, list) { <------><------>struct net_device *dev; <------><------>/* <------><------> * only add a note to our monitor buffer if: <------><------> * 1) this is the dev we received on <------><------> * 2) its after the last_rx delta <------><------> * 3) our rx_dropped count has gone up <------><------> */ <------><------>/* Paired with WRITE_ONCE() in dropmon_net_event() */ <------><------>dev = READ_ONCE(new_stat->dev); <------><------>if ((dev == napi->dev) && <------><------> (time_after(jiffies, new_stat->last_rx + dm_hw_check_delta)) && <------><------> (napi->dev->stats.rx_dropped != new_stat->last_drop_val)) { <------><------><------>trace_drop_common(NULL, NULL); <------><------><------>new_stat->last_drop_val = napi->dev->stats.rx_dropped; <------><------><------>new_stat->last_rx = jiffies; <------><------><------>break; <------><------>} <------>} <------>rcu_read_unlock(); } static struct net_dm_hw_entries * net_dm_hw_reset_per_cpu_data(struct per_cpu_dm_data *hw_data) { <------>struct net_dm_hw_entries *hw_entries; <------>unsigned long flags; <------>hw_entries = kzalloc(struct_size(hw_entries, entries, dm_hit_limit), <------><------><------> GFP_KERNEL); <------>if (!hw_entries) { <------><------>/* If the memory allocation failed, we try to perform another <------><------> * allocation in 1/10 second. Otherwise, the probe function <------><------> * will constantly bail out. <------><------> */ <------><------>mod_timer(&hw_data->send_timer, jiffies + HZ / 10); <------>} <------>spin_lock_irqsave(&hw_data->lock, flags); <------>swap(hw_data->hw_entries, hw_entries); <------>spin_unlock_irqrestore(&hw_data->lock, flags); <------>return hw_entries; } static int net_dm_hw_entry_put(struct sk_buff *msg, <------><------><------> const struct net_dm_hw_entry *hw_entry) { <------>struct nlattr *attr; <------>attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRY); <------>if (!attr) <------><------>return -EMSGSIZE; <------>if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME, hw_entry->trap_name)) <------><------>goto nla_put_failure; <------>if (nla_put_u32(msg, NET_DM_ATTR_HW_TRAP_COUNT, hw_entry->count)) <------><------>goto nla_put_failure; <------>nla_nest_end(msg, attr); <------>return 0; nla_put_failure: <------>nla_nest_cancel(msg, attr); <------>return -EMSGSIZE; } static int net_dm_hw_entries_put(struct sk_buff *msg, <------><------><------><------> const struct net_dm_hw_entries *hw_entries) { <------>struct nlattr *attr; <------>int i; <------>attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRIES); <------>if (!attr) <------><------>return -EMSGSIZE; <------>for (i = 0; i < hw_entries->num_entries; i++) { <------><------>int rc; <------><------>rc = net_dm_hw_entry_put(msg, &hw_entries->entries[i]); <------><------>if (rc) <------><------><------>goto nla_put_failure; <------>} <------>nla_nest_end(msg, attr); <------>return 0; nla_put_failure: <------>nla_nest_cancel(msg, attr); <------>return -EMSGSIZE; } static int net_dm_hw_summary_report_fill(struct sk_buff *msg, <------><------><------> const struct net_dm_hw_entries *hw_entries) { <------>struct net_dm_alert_msg anc_hdr = { 0 }; <------>void *hdr; <------>int rc; <------>hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0, <------><------><------> NET_DM_CMD_ALERT); <------>if (!hdr) <------><------>return -EMSGSIZE; <------>/* We need to put the ancillary header in order not to break user <------> * space. <------> */ <------>if (nla_put(msg, NLA_UNSPEC, sizeof(anc_hdr), &anc_hdr)) <------><------>goto nla_put_failure; <------>rc = net_dm_hw_entries_put(msg, hw_entries); <------>if (rc) <------><------>goto nla_put_failure; <------>genlmsg_end(msg, hdr); <------>return 0; nla_put_failure: <------>genlmsg_cancel(msg, hdr); <------>return -EMSGSIZE; } static void net_dm_hw_summary_work(struct work_struct *work) { <------>struct net_dm_hw_entries *hw_entries; <------>struct per_cpu_dm_data *hw_data; <------>struct sk_buff *msg; <------>int rc; <------>hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work); <------>hw_entries = net_dm_hw_reset_per_cpu_data(hw_data); <------>if (!hw_entries) <------><------>return; <------>msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); <------>if (!msg) <------><------>goto out; <------>rc = net_dm_hw_summary_report_fill(msg, hw_entries); <------>if (rc) { <------><------>nlmsg_free(msg); <------><------>goto out; <------>} <------>genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL); out: <------>kfree(hw_entries); } static void net_dm_hw_trap_summary_probe(void *ignore, const struct devlink *devlink, <------><------><------> struct sk_buff *skb, <------><------><------> const struct devlink_trap_metadata *metadata) { <------>struct net_dm_hw_entries *hw_entries; <------>struct net_dm_hw_entry *hw_entry; <------>struct per_cpu_dm_data *hw_data; <------>unsigned long flags; <------>int i; <------>if (metadata->trap_type == DEVLINK_TRAP_TYPE_CONTROL) <------><------>return; <------>hw_data = this_cpu_ptr(&dm_hw_cpu_data); <------>spin_lock_irqsave(&hw_data->lock, flags); <------>hw_entries = hw_data->hw_entries; <------>if (!hw_entries) <------><------>goto out; <------>for (i = 0; i < hw_entries->num_entries; i++) { <------><------>hw_entry = &hw_entries->entries[i]; <------><------>if (!strncmp(hw_entry->trap_name, metadata->trap_name, <------><------><------> NET_DM_MAX_HW_TRAP_NAME_LEN - 1)) { <------><------><------>hw_entry->count++; <------><------><------>goto out; <------><------>} <------>} <------>if (WARN_ON_ONCE(hw_entries->num_entries == dm_hit_limit)) <------><------>goto out; <------>hw_entry = &hw_entries->entries[hw_entries->num_entries]; <------>strlcpy(hw_entry->trap_name, metadata->trap_name, <------><------>NET_DM_MAX_HW_TRAP_NAME_LEN - 1); <------>hw_entry->count = 1; <------>hw_entries->num_entries++; <------>if (!timer_pending(&hw_data->send_timer)) { <------><------>hw_data->send_timer.expires = jiffies + dm_delay * HZ; <------><------>add_timer(&hw_data->send_timer); <------>} out: <------>spin_unlock_irqrestore(&hw_data->lock, flags); } static const struct net_dm_alert_ops net_dm_alert_summary_ops = { <------>.kfree_skb_probe = trace_kfree_skb_hit, <------>.napi_poll_probe = trace_napi_poll_hit, <------>.work_item_func = send_dm_alert, <------>.hw_work_item_func = net_dm_hw_summary_work, <------>.hw_trap_probe = net_dm_hw_trap_summary_probe, }; static void net_dm_packet_trace_kfree_skb_hit(void *ignore, <------><------><------><------><------> struct sk_buff *skb, <------><------><------><------><------> void *location) { <------>ktime_t tstamp = ktime_get_real(); <------>struct per_cpu_dm_data *data; <------>struct sk_buff *nskb; <------>unsigned long flags; <------>if (!skb_mac_header_was_set(skb)) <------><------>return; <------>nskb = skb_clone(skb, GFP_ATOMIC); <------>if (!nskb) <------><------>return; <------>NET_DM_SKB_CB(nskb)->pc = location; <------>/* Override the timestamp because we care about the time when the <------> * packet was dropped. <------> */ <------>nskb->tstamp = tstamp; <------>data = this_cpu_ptr(&dm_cpu_data); <------>spin_lock_irqsave(&data->drop_queue.lock, flags); <------>if (skb_queue_len(&data->drop_queue) < net_dm_queue_len) <------><------>__skb_queue_tail(&data->drop_queue, nskb); <------>else <------><------>goto unlock_free; <------>spin_unlock_irqrestore(&data->drop_queue.lock, flags); <------>schedule_work(&data->dm_alert_work); <------>return; unlock_free: <------>spin_unlock_irqrestore(&data->drop_queue.lock, flags); <------>u64_stats_update_begin(&data->stats.syncp); <------>data->stats.dropped++; <------>u64_stats_update_end(&data->stats.syncp); <------>consume_skb(nskb); } static void net_dm_packet_trace_napi_poll_hit(void *ignore, <------><------><------><------><------> struct napi_struct *napi, <------><------><------><------><------> int work, int budget) { } static size_t net_dm_in_port_size(void) { <------> /* NET_DM_ATTR_IN_PORT nest */ <------>return nla_total_size(0) + <------> /* NET_DM_ATTR_PORT_NETDEV_IFINDEX */ <------> nla_total_size(sizeof(u32)) + <------> /* NET_DM_ATTR_PORT_NETDEV_NAME */ <------> nla_total_size(IFNAMSIZ + 1); } #define NET_DM_MAX_SYMBOL_LEN 40 static size_t net_dm_packet_report_size(size_t payload_len) { <------>size_t size; <------>size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize); <------>return NLMSG_ALIGN(size) + <------> /* NET_DM_ATTR_ORIGIN */ <------> nla_total_size(sizeof(u16)) + <------> /* NET_DM_ATTR_PC */ <------> nla_total_size(sizeof(u64)) + <------> /* NET_DM_ATTR_SYMBOL */ <------> nla_total_size(NET_DM_MAX_SYMBOL_LEN + 1) + <------> /* NET_DM_ATTR_IN_PORT */ <------> net_dm_in_port_size() + <------> /* NET_DM_ATTR_TIMESTAMP */ <------> nla_total_size(sizeof(u64)) + <------> /* NET_DM_ATTR_ORIG_LEN */ <------> nla_total_size(sizeof(u32)) + <------> /* NET_DM_ATTR_PROTO */ <------> nla_total_size(sizeof(u16)) + <------> /* NET_DM_ATTR_PAYLOAD */ <------> nla_total_size(payload_len); } static int net_dm_packet_report_in_port_put(struct sk_buff *msg, int ifindex, <------><------><------><------><------> const char *name) { <------>struct nlattr *attr; <------>attr = nla_nest_start(msg, NET_DM_ATTR_IN_PORT); <------>if (!attr) <------><------>return -EMSGSIZE; <------>if (ifindex && <------> nla_put_u32(msg, NET_DM_ATTR_PORT_NETDEV_IFINDEX, ifindex)) <------><------>goto nla_put_failure; <------>if (name && nla_put_string(msg, NET_DM_ATTR_PORT_NETDEV_NAME, name)) <------><------>goto nla_put_failure; <------>nla_nest_end(msg, attr); <------>return 0; nla_put_failure: <------>nla_nest_cancel(msg, attr); <------>return -EMSGSIZE; } static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb, <------><------><------><------> size_t payload_len) { <------>u64 pc = (u64)(uintptr_t) NET_DM_SKB_CB(skb)->pc; <------>char buf[NET_DM_MAX_SYMBOL_LEN]; <------>struct nlattr *attr; <------>void *hdr; <------>int rc; <------>hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0, <------><------><------> NET_DM_CMD_PACKET_ALERT); <------>if (!hdr) <------><------>return -EMSGSIZE; <------>if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_SW)) <------><------>goto nla_put_failure; <------>if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, pc, NET_DM_ATTR_PAD)) <------><------>goto nla_put_failure; <------>snprintf(buf, sizeof(buf), "%pS", NET_DM_SKB_CB(skb)->pc); <------>if (nla_put_string(msg, NET_DM_ATTR_SYMBOL, buf)) <------><------>goto nla_put_failure; <------>rc = net_dm_packet_report_in_port_put(msg, skb->skb_iif, NULL); <------>if (rc) <------><------>goto nla_put_failure; <------>if (nla_put_u64_64bit(msg, NET_DM_ATTR_TIMESTAMP, <------><------><------> ktime_to_ns(skb->tstamp), NET_DM_ATTR_PAD)) <------><------>goto nla_put_failure; <------>if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len)) <------><------>goto nla_put_failure; <------>if (!payload_len) <------><------>goto out; <------>if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol))) <------><------>goto nla_put_failure; <------>attr = skb_put(msg, nla_total_size(payload_len)); <------>attr->nla_type = NET_DM_ATTR_PAYLOAD; <------>attr->nla_len = nla_attr_size(payload_len); <------>if (skb_copy_bits(skb, 0, nla_data(attr), payload_len)) <------><------>goto nla_put_failure; out: <------>genlmsg_end(msg, hdr); <------>return 0; nla_put_failure: <------>genlmsg_cancel(msg, hdr); <------>return -EMSGSIZE; } #define NET_DM_MAX_PACKET_SIZE (0xffff - NLA_HDRLEN - NLA_ALIGNTO) static void net_dm_packet_report(struct sk_buff *skb) { <------>struct sk_buff *msg; <------>size_t payload_len; <------>int rc; <------>/* Make sure we start copying the packet from the MAC header */ <------>if (skb->data > skb_mac_header(skb)) <------><------>skb_push(skb, skb->data - skb_mac_header(skb)); <------>else <------><------>skb_pull(skb, skb_mac_header(skb) - skb->data); <------>/* Ensure packet fits inside a single netlink attribute */ <------>payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE); <------>if (net_dm_trunc_len) <------><------>payload_len = min_t(size_t, net_dm_trunc_len, payload_len); <------>msg = nlmsg_new(net_dm_packet_report_size(payload_len), GFP_KERNEL); <------>if (!msg) <------><------>goto out; <------>rc = net_dm_packet_report_fill(msg, skb, payload_len); <------>if (rc) { <------><------>nlmsg_free(msg); <------><------>goto out; <------>} <------>genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL); out: <------>consume_skb(skb); } static void net_dm_packet_work(struct work_struct *work) { <------>struct per_cpu_dm_data *data; <------>struct sk_buff_head list; <------>struct sk_buff *skb; <------>unsigned long flags; <------>data = container_of(work, struct per_cpu_dm_data, dm_alert_work); <------>__skb_queue_head_init(&list); <------>spin_lock_irqsave(&data->drop_queue.lock, flags); <------>skb_queue_splice_tail_init(&data->drop_queue, &list); <------>spin_unlock_irqrestore(&data->drop_queue.lock, flags); <------>while ((skb = __skb_dequeue(&list))) <------><------>net_dm_packet_report(skb); } static size_t net_dm_flow_action_cookie_size(const struct devlink_trap_metadata *hw_metadata) { <------>return hw_metadata->fa_cookie ? <------> nla_total_size(hw_metadata->fa_cookie->cookie_len) : 0; } static size_t net_dm_hw_packet_report_size(size_t payload_len, <------><------><------> const struct devlink_trap_metadata *hw_metadata) { <------>size_t size; <------>size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize); <------>return NLMSG_ALIGN(size) + <------> /* NET_DM_ATTR_ORIGIN */ <------> nla_total_size(sizeof(u16)) + <------> /* NET_DM_ATTR_HW_TRAP_GROUP_NAME */ <------> nla_total_size(strlen(hw_metadata->trap_group_name) + 1) + <------> /* NET_DM_ATTR_HW_TRAP_NAME */ <------> nla_total_size(strlen(hw_metadata->trap_name) + 1) + <------> /* NET_DM_ATTR_IN_PORT */ <------> net_dm_in_port_size() + <------> /* NET_DM_ATTR_FLOW_ACTION_COOKIE */ <------> net_dm_flow_action_cookie_size(hw_metadata) + <------> /* NET_DM_ATTR_TIMESTAMP */ <------> nla_total_size(sizeof(u64)) + <------> /* NET_DM_ATTR_ORIG_LEN */ <------> nla_total_size(sizeof(u32)) + <------> /* NET_DM_ATTR_PROTO */ <------> nla_total_size(sizeof(u16)) + <------> /* NET_DM_ATTR_PAYLOAD */ <------> nla_total_size(payload_len); } static int net_dm_hw_packet_report_fill(struct sk_buff *msg, <------><------><------><------><------>struct sk_buff *skb, size_t payload_len) { <------>struct devlink_trap_metadata *hw_metadata; <------>struct nlattr *attr; <------>void *hdr; <------>hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata; <------>hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0, <------><------><------> NET_DM_CMD_PACKET_ALERT); <------>if (!hdr) <------><------>return -EMSGSIZE; <------>if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_HW)) <------><------>goto nla_put_failure; <------>if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_GROUP_NAME, <------><------><------> hw_metadata->trap_group_name)) <------><------>goto nla_put_failure; <------>if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME, <------><------><------> hw_metadata->trap_name)) <------><------>goto nla_put_failure; <------>if (hw_metadata->input_dev) { <------><------>struct net_device *dev = hw_metadata->input_dev; <------><------>int rc; <------><------>rc = net_dm_packet_report_in_port_put(msg, dev->ifindex, <------><------><------><------><------><------> dev->name); <------><------>if (rc) <------><------><------>goto nla_put_failure; <------>} <------>if (hw_metadata->fa_cookie && <------> nla_put(msg, NET_DM_ATTR_FLOW_ACTION_COOKIE, <------><------> hw_metadata->fa_cookie->cookie_len, <------><------> hw_metadata->fa_cookie->cookie)) <------><------>goto nla_put_failure; <------>if (nla_put_u64_64bit(msg, NET_DM_ATTR_TIMESTAMP, <------><------><------> ktime_to_ns(skb->tstamp), NET_DM_ATTR_PAD)) <------><------>goto nla_put_failure; <------>if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len)) <------><------>goto nla_put_failure; <------>if (!payload_len) <------><------>goto out; <------>if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol))) <------><------>goto nla_put_failure; <------>attr = skb_put(msg, nla_total_size(payload_len)); <------>attr->nla_type = NET_DM_ATTR_PAYLOAD; <------>attr->nla_len = nla_attr_size(payload_len); <------>if (skb_copy_bits(skb, 0, nla_data(attr), payload_len)) <------><------>goto nla_put_failure; out: <------>genlmsg_end(msg, hdr); <------>return 0; nla_put_failure: <------>genlmsg_cancel(msg, hdr); <------>return -EMSGSIZE; } static struct devlink_trap_metadata * net_dm_hw_metadata_copy(const struct devlink_trap_metadata *metadata) { <------>const struct flow_action_cookie *fa_cookie; <------>struct devlink_trap_metadata *hw_metadata; <------>const char *trap_group_name; <------>const char *trap_name; <------>hw_metadata = kzalloc(sizeof(*hw_metadata), GFP_ATOMIC); <------>if (!hw_metadata) <------><------>return NULL; <------>trap_group_name = kstrdup(metadata->trap_group_name, GFP_ATOMIC); <------>if (!trap_group_name) <------><------>goto free_hw_metadata; <------>hw_metadata->trap_group_name = trap_group_name; <------>trap_name = kstrdup(metadata->trap_name, GFP_ATOMIC); <------>if (!trap_name) <------><------>goto free_trap_group; <------>hw_metadata->trap_name = trap_name; <------>if (metadata->fa_cookie) { <------><------>size_t cookie_size = sizeof(*fa_cookie) + <------><------><------><------> metadata->fa_cookie->cookie_len; <------><------>fa_cookie = kmemdup(metadata->fa_cookie, cookie_size, <------><------><------><------> GFP_ATOMIC); <------><------>if (!fa_cookie) <------><------><------>goto free_trap_name; <------><------>hw_metadata->fa_cookie = fa_cookie; <------>} <------>hw_metadata->input_dev = metadata->input_dev; <------>if (hw_metadata->input_dev) <------><------>dev_hold(hw_metadata->input_dev); <------>return hw_metadata; free_trap_name: <------>kfree(trap_name); free_trap_group: <------>kfree(trap_group_name); free_hw_metadata: <------>kfree(hw_metadata); <------>return NULL; } static void net_dm_hw_metadata_free(const struct devlink_trap_metadata *hw_metadata) { <------>if (hw_metadata->input_dev) <------><------>dev_put(hw_metadata->input_dev); <------>kfree(hw_metadata->fa_cookie); <------>kfree(hw_metadata->trap_name); <------>kfree(hw_metadata->trap_group_name); <------>kfree(hw_metadata); } static void net_dm_hw_packet_report(struct sk_buff *skb) { <------>struct devlink_trap_metadata *hw_metadata; <------>struct sk_buff *msg; <------>size_t payload_len; <------>int rc; <------>if (skb->data > skb_mac_header(skb)) <------><------>skb_push(skb, skb->data - skb_mac_header(skb)); <------>else <------><------>skb_pull(skb, skb_mac_header(skb) - skb->data); <------>payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE); <------>if (net_dm_trunc_len) <------><------>payload_len = min_t(size_t, net_dm_trunc_len, payload_len); <------>hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata; <------>msg = nlmsg_new(net_dm_hw_packet_report_size(payload_len, hw_metadata), <------><------><------>GFP_KERNEL); <------>if (!msg) <------><------>goto out; <------>rc = net_dm_hw_packet_report_fill(msg, skb, payload_len); <------>if (rc) { <------><------>nlmsg_free(msg); <------><------>goto out; <------>} <------>genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL); out: <------>net_dm_hw_metadata_free(NET_DM_SKB_CB(skb)->hw_metadata); <------>consume_skb(skb); } static void net_dm_hw_packet_work(struct work_struct *work) { <------>struct per_cpu_dm_data *hw_data; <------>struct sk_buff_head list; <------>struct sk_buff *skb; <------>unsigned long flags; <------>hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work); <------>__skb_queue_head_init(&list); <------>spin_lock_irqsave(&hw_data->drop_queue.lock, flags); <------>skb_queue_splice_tail_init(&hw_data->drop_queue, &list); <------>spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags); <------>while ((skb = __skb_dequeue(&list))) <------><------>net_dm_hw_packet_report(skb); } static void net_dm_hw_trap_packet_probe(void *ignore, const struct devlink *devlink, <------><------><------> struct sk_buff *skb, <------><------><------> const struct devlink_trap_metadata *metadata) { <------>struct devlink_trap_metadata *n_hw_metadata; <------>ktime_t tstamp = ktime_get_real(); <------>struct per_cpu_dm_data *hw_data; <------>struct sk_buff *nskb; <------>unsigned long flags; <------>if (metadata->trap_type == DEVLINK_TRAP_TYPE_CONTROL) <------><------>return; <------>if (!skb_mac_header_was_set(skb)) <------><------>return; <------>nskb = skb_clone(skb, GFP_ATOMIC); <------>if (!nskb) <------><------>return; <------>n_hw_metadata = net_dm_hw_metadata_copy(metadata); <------>if (!n_hw_metadata) <------><------>goto free; <------>NET_DM_SKB_CB(nskb)->hw_metadata = n_hw_metadata; <------>nskb->tstamp = tstamp; <------>hw_data = this_cpu_ptr(&dm_hw_cpu_data); <------>spin_lock_irqsave(&hw_data->drop_queue.lock, flags); <------>if (skb_queue_len(&hw_data->drop_queue) < net_dm_queue_len) <------><------>__skb_queue_tail(&hw_data->drop_queue, nskb); <------>else <------><------>goto unlock_free; <------>spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags); <------>schedule_work(&hw_data->dm_alert_work); <------>return; unlock_free: <------>spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags); <------>u64_stats_update_begin(&hw_data->stats.syncp); <------>hw_data->stats.dropped++; <------>u64_stats_update_end(&hw_data->stats.syncp); <------>net_dm_hw_metadata_free(n_hw_metadata); free: <------>consume_skb(nskb); } static const struct net_dm_alert_ops net_dm_alert_packet_ops = { <------>.kfree_skb_probe = net_dm_packet_trace_kfree_skb_hit, <------>.napi_poll_probe = net_dm_packet_trace_napi_poll_hit, <------>.work_item_func = net_dm_packet_work, <------>.hw_work_item_func = net_dm_hw_packet_work, <------>.hw_trap_probe = net_dm_hw_trap_packet_probe, }; static const struct net_dm_alert_ops *net_dm_alert_ops_arr[] = { <------>[NET_DM_ALERT_MODE_SUMMARY] = &net_dm_alert_summary_ops, <------>[NET_DM_ALERT_MODE_PACKET] = &net_dm_alert_packet_ops, }; #if IS_ENABLED(CONFIG_NET_DEVLINK) static int net_dm_hw_probe_register(const struct net_dm_alert_ops *ops) { <------>return register_trace_devlink_trap_report(ops->hw_trap_probe, NULL); } static void net_dm_hw_probe_unregister(const struct net_dm_alert_ops *ops) { <------>unregister_trace_devlink_trap_report(ops->hw_trap_probe, NULL); <------>tracepoint_synchronize_unregister(); } #else static int net_dm_hw_probe_register(const struct net_dm_alert_ops *ops) { <------>return -EOPNOTSUPP; } static void net_dm_hw_probe_unregister(const struct net_dm_alert_ops *ops) { } #endif static int net_dm_hw_monitor_start(struct netlink_ext_ack *extack) { <------>const struct net_dm_alert_ops *ops; <------>int cpu, rc; <------>if (monitor_hw) { <------><------>NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already enabled"); <------><------>return -EAGAIN; <------>} <------>ops = net_dm_alert_ops_arr[net_dm_alert_mode]; <------>if (!try_module_get(THIS_MODULE)) { <------><------>NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module"); <------><------>return -ENODEV; <------>} <------>for_each_possible_cpu(cpu) { <------><------>struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu); <------><------>struct net_dm_hw_entries *hw_entries; <------><------>INIT_WORK(&hw_data->dm_alert_work, ops->hw_work_item_func); <------><------>timer_setup(&hw_data->send_timer, sched_send_work, 0); <------><------>hw_entries = net_dm_hw_reset_per_cpu_data(hw_data); <------><------>kfree(hw_entries); <------>} <------>rc = net_dm_hw_probe_register(ops); <------>if (rc) { <------><------>NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to devlink_trap_probe() tracepoint"); <------><------>goto err_module_put; <------>} <------>monitor_hw = true; <------>return 0; err_module_put: <------>for_each_possible_cpu(cpu) { <------><------>struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu); <------><------>struct sk_buff *skb; <------><------>del_timer_sync(&hw_data->send_timer); <------><------>cancel_work_sync(&hw_data->dm_alert_work); <------><------>while ((skb = __skb_dequeue(&hw_data->drop_queue))) { <------><------><------>struct devlink_trap_metadata *hw_metadata; <------><------><------>hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata; <------><------><------>net_dm_hw_metadata_free(hw_metadata); <------><------><------>consume_skb(skb); <------><------>} <------>} <------>module_put(THIS_MODULE); <------>return rc; } static void net_dm_hw_monitor_stop(struct netlink_ext_ack *extack) { <------>const struct net_dm_alert_ops *ops; <------>int cpu; <------>if (!monitor_hw) { <------><------>NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already disabled"); <------><------>return; <------>} <------>ops = net_dm_alert_ops_arr[net_dm_alert_mode]; <------>monitor_hw = false; <------>net_dm_hw_probe_unregister(ops); <------>for_each_possible_cpu(cpu) { <------><------>struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu); <------><------>struct sk_buff *skb; <------><------>del_timer_sync(&hw_data->send_timer); <------><------>cancel_work_sync(&hw_data->dm_alert_work); <------><------>while ((skb = __skb_dequeue(&hw_data->drop_queue))) { <------><------><------>struct devlink_trap_metadata *hw_metadata; <------><------><------>hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata; <------><------><------>net_dm_hw_metadata_free(hw_metadata); <------><------><------>consume_skb(skb); <------><------>} <------>} <------>module_put(THIS_MODULE); } static int net_dm_trace_on_set(struct netlink_ext_ack *extack) { <------>const struct net_dm_alert_ops *ops; <------>int cpu, rc; <------>ops = net_dm_alert_ops_arr[net_dm_alert_mode]; <------>if (!try_module_get(THIS_MODULE)) { <------><------>NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module"); <------><------>return -ENODEV; <------>} <------>for_each_possible_cpu(cpu) { <------><------>struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu); <------><------>struct sk_buff *skb; <------><------>INIT_WORK(&data->dm_alert_work, ops->work_item_func); <------><------>timer_setup(&data->send_timer, sched_send_work, 0); <------><------>/* Allocate a new per-CPU skb for the summary alert message and <------><------> * free the old one which might contain stale data from <------><------> * previous tracing. <------><------> */ <------><------>skb = reset_per_cpu_data(data); <------><------>consume_skb(skb); <------>} <------>rc = register_trace_kfree_skb(ops->kfree_skb_probe, NULL); <------>if (rc) { <------><------>NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to kfree_skb() tracepoint"); <------><------>goto err_module_put; <------>} <------>rc = register_trace_napi_poll(ops->napi_poll_probe, NULL); <------>if (rc) { <------><------>NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to napi_poll() tracepoint"); <------><------>goto err_unregister_trace; <------>} <------>return 0; err_unregister_trace: <------>unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL); err_module_put: <------>for_each_possible_cpu(cpu) { <------><------>struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu); <------><------>struct sk_buff *skb; <------><------>del_timer_sync(&data->send_timer); <------><------>cancel_work_sync(&data->dm_alert_work); <------><------>while ((skb = __skb_dequeue(&data->drop_queue))) <------><------><------>consume_skb(skb); <------>} <------>module_put(THIS_MODULE); <------>return rc; } static void net_dm_trace_off_set(void) { <------>struct dm_hw_stat_delta *new_stat, *temp; <------>const struct net_dm_alert_ops *ops; <------>int cpu; <------>ops = net_dm_alert_ops_arr[net_dm_alert_mode]; <------>unregister_trace_napi_poll(ops->napi_poll_probe, NULL); <------>unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL); <------>tracepoint_synchronize_unregister(); <------>/* Make sure we do not send notifications to user space after request <------> * to stop tracing returns. <------> */ <------>for_each_possible_cpu(cpu) { <------><------>struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu); <------><------>struct sk_buff *skb; <------><------>del_timer_sync(&data->send_timer); <------><------>cancel_work_sync(&data->dm_alert_work); <------><------>while ((skb = __skb_dequeue(&data->drop_queue))) <------><------><------>consume_skb(skb); <------>} <------>list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) { <------><------>if (new_stat->dev == NULL) { <------><------><------>list_del_rcu(&new_stat->list); <------><------><------>kfree_rcu(new_stat, rcu); <------><------>} <------>} <------>module_put(THIS_MODULE); } static int set_all_monitor_traces(int state, struct netlink_ext_ack *extack) { <------>int rc = 0; <------>if (state == trace_state) { <------><------>NL_SET_ERR_MSG_MOD(extack, "Trace state already set to requested state"); <------><------>return -EAGAIN; <------>} <------>switch (state) { <------>case TRACE_ON: <------><------>rc = net_dm_trace_on_set(extack); <------><------>break; <------>case TRACE_OFF: <------><------>net_dm_trace_off_set(); <------><------>break; <------>default: <------><------>rc = 1; <------><------>break; <------>} <------>if (!rc) <------><------>trace_state = state; <------>else <------><------>rc = -EINPROGRESS; <------>return rc; } static bool net_dm_is_monitoring(void) { <------>return trace_state == TRACE_ON || monitor_hw; } static int net_dm_alert_mode_get_from_info(struct genl_info *info, <------><------><------><------><------> enum net_dm_alert_mode *p_alert_mode) { <------>u8 val; <------>val = nla_get_u8(info->attrs[NET_DM_ATTR_ALERT_MODE]); <------>switch (val) { <------>case NET_DM_ALERT_MODE_SUMMARY: <------>case NET_DM_ALERT_MODE_PACKET: <------><------>*p_alert_mode = val; <------><------>break; <------>default: <------><------>return -EINVAL; <------>} <------>return 0; } static int net_dm_alert_mode_set(struct genl_info *info) { <------>struct netlink_ext_ack *extack = info->extack; <------>enum net_dm_alert_mode alert_mode; <------>int rc; <------>if (!info->attrs[NET_DM_ATTR_ALERT_MODE]) <------><------>return 0; <------>rc = net_dm_alert_mode_get_from_info(info, &alert_mode); <------>if (rc) { <------><------>NL_SET_ERR_MSG_MOD(extack, "Invalid alert mode"); <------><------>return -EINVAL; <------>} <------>net_dm_alert_mode = alert_mode; <------>return 0; } static void net_dm_trunc_len_set(struct genl_info *info) { <------>if (!info->attrs[NET_DM_ATTR_TRUNC_LEN]) <------><------>return; <------>net_dm_trunc_len = nla_get_u32(info->attrs[NET_DM_ATTR_TRUNC_LEN]); } static void net_dm_queue_len_set(struct genl_info *info) { <------>if (!info->attrs[NET_DM_ATTR_QUEUE_LEN]) <------><------>return; <------>net_dm_queue_len = nla_get_u32(info->attrs[NET_DM_ATTR_QUEUE_LEN]); } static int net_dm_cmd_config(struct sk_buff *skb, <------><------><------>struct genl_info *info) { <------>struct netlink_ext_ack *extack = info->extack; <------>int rc; <------>if (net_dm_is_monitoring()) { <------><------>NL_SET_ERR_MSG_MOD(extack, "Cannot configure drop monitor during monitoring"); <------><------>return -EBUSY; <------>} <------>rc = net_dm_alert_mode_set(info); <------>if (rc) <------><------>return rc; <------>net_dm_trunc_len_set(info); <------>net_dm_queue_len_set(info); <------>return 0; } static int net_dm_monitor_start(bool set_sw, bool set_hw, <------><------><------><------>struct netlink_ext_ack *extack) { <------>bool sw_set = false; <------>int rc; <------>if (set_sw) { <------><------>rc = set_all_monitor_traces(TRACE_ON, extack); <------><------>if (rc) <------><------><------>return rc; <------><------>sw_set = true; <------>} <------>if (set_hw) { <------><------>rc = net_dm_hw_monitor_start(extack); <------><------>if (rc) <------><------><------>goto err_monitor_hw; <------>} <------>return 0; err_monitor_hw: <------>if (sw_set) <------><------>set_all_monitor_traces(TRACE_OFF, extack); <------>return rc; } static void net_dm_monitor_stop(bool set_sw, bool set_hw, <------><------><------><------>struct netlink_ext_ack *extack) { <------>if (set_hw) <------><------>net_dm_hw_monitor_stop(extack); <------>if (set_sw) <------><------>set_all_monitor_traces(TRACE_OFF, extack); } static int net_dm_cmd_trace(struct sk_buff *skb, <------><------><------>struct genl_info *info) { <------>bool set_sw = !!info->attrs[NET_DM_ATTR_SW_DROPS]; <------>bool set_hw = !!info->attrs[NET_DM_ATTR_HW_DROPS]; <------>struct netlink_ext_ack *extack = info->extack; <------>/* To maintain backward compatibility, we start / stop monitoring of <------> * software drops if no flag is specified. <------> */ <------>if (!set_sw && !set_hw) <------><------>set_sw = true; <------>switch (info->genlhdr->cmd) { <------>case NET_DM_CMD_START: <------><------>return net_dm_monitor_start(set_sw, set_hw, extack); <------>case NET_DM_CMD_STOP: <------><------>net_dm_monitor_stop(set_sw, set_hw, extack); <------><------>return 0; <------>} <------>return -EOPNOTSUPP; } static int net_dm_config_fill(struct sk_buff *msg, struct genl_info *info) { <------>void *hdr; <------>hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq, <------><------><------> &net_drop_monitor_family, 0, NET_DM_CMD_CONFIG_NEW); <------>if (!hdr) <------><------>return -EMSGSIZE; <------>if (nla_put_u8(msg, NET_DM_ATTR_ALERT_MODE, net_dm_alert_mode)) <------><------>goto nla_put_failure; <------>if (nla_put_u32(msg, NET_DM_ATTR_TRUNC_LEN, net_dm_trunc_len)) <------><------>goto nla_put_failure; <------>if (nla_put_u32(msg, NET_DM_ATTR_QUEUE_LEN, net_dm_queue_len)) <------><------>goto nla_put_failure; <------>genlmsg_end(msg, hdr); <------>return 0; nla_put_failure: <------>genlmsg_cancel(msg, hdr); <------>return -EMSGSIZE; } static int net_dm_cmd_config_get(struct sk_buff *skb, struct genl_info *info) { <------>struct sk_buff *msg; <------>int rc; <------>msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); <------>if (!msg) <------><------>return -ENOMEM; <------>rc = net_dm_config_fill(msg, info); <------>if (rc) <------><------>goto free_msg; <------>return genlmsg_reply(msg, info); free_msg: <------>nlmsg_free(msg); <------>return rc; } static void net_dm_stats_read(struct net_dm_stats *stats) { <------>int cpu; <------>memset(stats, 0, sizeof(*stats)); <------>for_each_possible_cpu(cpu) { <------><------>struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu); <------><------>struct net_dm_stats *cpu_stats = &data->stats; <------><------>unsigned int start; <------><------>u64 dropped; <------><------>do { <------><------><------>start = u64_stats_fetch_begin_irq(&cpu_stats->syncp); <------><------><------>dropped = cpu_stats->dropped; <------><------>} while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start)); <------><------>stats->dropped += dropped; <------>} } static int net_dm_stats_put(struct sk_buff *msg) { <------>struct net_dm_stats stats; <------>struct nlattr *attr; <------>net_dm_stats_read(&stats); <------>attr = nla_nest_start(msg, NET_DM_ATTR_STATS); <------>if (!attr) <------><------>return -EMSGSIZE; <------>if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED, <------><------><------> stats.dropped, NET_DM_ATTR_PAD)) <------><------>goto nla_put_failure; <------>nla_nest_end(msg, attr); <------>return 0; nla_put_failure: <------>nla_nest_cancel(msg, attr); <------>return -EMSGSIZE; } static void net_dm_hw_stats_read(struct net_dm_stats *stats) { <------>int cpu; <------>memset(stats, 0, sizeof(*stats)); <------>for_each_possible_cpu(cpu) { <------><------>struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu); <------><------>struct net_dm_stats *cpu_stats = &hw_data->stats; <------><------>unsigned int start; <------><------>u64 dropped; <------><------>do { <------><------><------>start = u64_stats_fetch_begin_irq(&cpu_stats->syncp); <------><------><------>dropped = cpu_stats->dropped; <------><------>} while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start)); <------><------>stats->dropped += dropped; <------>} } static int net_dm_hw_stats_put(struct sk_buff *msg) { <------>struct net_dm_stats stats; <------>struct nlattr *attr; <------>net_dm_hw_stats_read(&stats); <------>attr = nla_nest_start(msg, NET_DM_ATTR_HW_STATS); <------>if (!attr) <------><------>return -EMSGSIZE; <------>if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED, <------><------><------> stats.dropped, NET_DM_ATTR_PAD)) <------><------>goto nla_put_failure; <------>nla_nest_end(msg, attr); <------>return 0; nla_put_failure: <------>nla_nest_cancel(msg, attr); <------>return -EMSGSIZE; } static int net_dm_stats_fill(struct sk_buff *msg, struct genl_info *info) { <------>void *hdr; <------>int rc; <------>hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq, <------><------><------> &net_drop_monitor_family, 0, NET_DM_CMD_STATS_NEW); <------>if (!hdr) <------><------>return -EMSGSIZE; <------>rc = net_dm_stats_put(msg); <------>if (rc) <------><------>goto nla_put_failure; <------>rc = net_dm_hw_stats_put(msg); <------>if (rc) <------><------>goto nla_put_failure; <------>genlmsg_end(msg, hdr); <------>return 0; nla_put_failure: <------>genlmsg_cancel(msg, hdr); <------>return -EMSGSIZE; } static int net_dm_cmd_stats_get(struct sk_buff *skb, struct genl_info *info) { <------>struct sk_buff *msg; <------>int rc; <------>msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); <------>if (!msg) <------><------>return -ENOMEM; <------>rc = net_dm_stats_fill(msg, info); <------>if (rc) <------><------>goto free_msg; <------>return genlmsg_reply(msg, info); free_msg: <------>nlmsg_free(msg); <------>return rc; } static int dropmon_net_event(struct notifier_block *ev_block, <------><------><------> unsigned long event, void *ptr) { <------>struct net_device *dev = netdev_notifier_info_to_dev(ptr); <------>struct dm_hw_stat_delta *new_stat = NULL; <------>struct dm_hw_stat_delta *tmp; <------>switch (event) { <------>case NETDEV_REGISTER: <------><------>new_stat = kzalloc(sizeof(struct dm_hw_stat_delta), GFP_KERNEL); <------><------>if (!new_stat) <------><------><------>goto out; <------><------>new_stat->dev = dev; <------><------>new_stat->last_rx = jiffies; <------><------>mutex_lock(&net_dm_mutex); <------><------>list_add_rcu(&new_stat->list, &hw_stats_list); <------><------>mutex_unlock(&net_dm_mutex); <------><------>break; <------>case NETDEV_UNREGISTER: <------><------>mutex_lock(&net_dm_mutex); <------><------>list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) { <------><------><------>if (new_stat->dev == dev) { <------><------><------><------>/* Paired with READ_ONCE() in trace_napi_poll_hit() */ <------><------><------><------>WRITE_ONCE(new_stat->dev, NULL); <------><------><------><------>if (trace_state == TRACE_OFF) { <------><------><------><------><------>list_del_rcu(&new_stat->list); <------><------><------><------><------>kfree_rcu(new_stat, rcu); <------><------><------><------><------>break; <------><------><------><------>} <------><------><------>} <------><------>} <------><------>mutex_unlock(&net_dm_mutex); <------><------>break; <------>} out: <------>return NOTIFY_DONE; } static const struct nla_policy net_dm_nl_policy[NET_DM_ATTR_MAX + 1] = { <------>[NET_DM_ATTR_UNSPEC] = { .strict_start_type = NET_DM_ATTR_UNSPEC + 1 }, <------>[NET_DM_ATTR_ALERT_MODE] = { .type = NLA_U8 }, <------>[NET_DM_ATTR_TRUNC_LEN] = { .type = NLA_U32 }, <------>[NET_DM_ATTR_QUEUE_LEN] = { .type = NLA_U32 }, <------>[NET_DM_ATTR_SW_DROPS] = {. type = NLA_FLAG }, <------>[NET_DM_ATTR_HW_DROPS] = {. type = NLA_FLAG }, }; static const struct genl_small_ops dropmon_ops[] = { <------>{ <------><------>.cmd = NET_DM_CMD_CONFIG, <------><------>.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, <------><------>.doit = net_dm_cmd_config, <------><------>.flags = GENL_ADMIN_PERM, <------>}, <------>{ <------><------>.cmd = NET_DM_CMD_START, <------><------>.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, <------><------>.doit = net_dm_cmd_trace, <------>}, <------>{ <------><------>.cmd = NET_DM_CMD_STOP, <------><------>.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, <------><------>.doit = net_dm_cmd_trace, <------>}, <------>{ <------><------>.cmd = NET_DM_CMD_CONFIG_GET, <------><------>.doit = net_dm_cmd_config_get, <------>}, <------>{ <------><------>.cmd = NET_DM_CMD_STATS_GET, <------><------>.doit = net_dm_cmd_stats_get, <------>}, }; static int net_dm_nl_pre_doit(const struct genl_ops *ops, <------><------><------> struct sk_buff *skb, struct genl_info *info) { <------>mutex_lock(&net_dm_mutex); <------>return 0; } static void net_dm_nl_post_doit(const struct genl_ops *ops, <------><------><------><------>struct sk_buff *skb, struct genl_info *info) { <------>mutex_unlock(&net_dm_mutex); } static struct genl_family net_drop_monitor_family __ro_after_init = { <------>.hdrsize = 0, <------>.name = "NET_DM", <------>.version = 2, <------>.maxattr = NET_DM_ATTR_MAX, <------>.policy = net_dm_nl_policy, <------>.pre_doit = net_dm_nl_pre_doit, <------>.post_doit = net_dm_nl_post_doit, <------>.module = THIS_MODULE, <------>.small_ops = dropmon_ops, <------>.n_small_ops = ARRAY_SIZE(dropmon_ops), <------>.mcgrps = dropmon_mcgrps, <------>.n_mcgrps = ARRAY_SIZE(dropmon_mcgrps), }; static struct notifier_block dropmon_net_notifier = { <------>.notifier_call = dropmon_net_event }; static void __net_dm_cpu_data_init(struct per_cpu_dm_data *data) { <------>spin_lock_init(&data->lock); <------>skb_queue_head_init(&data->drop_queue); <------>u64_stats_init(&data->stats.syncp); } static void __net_dm_cpu_data_fini(struct per_cpu_dm_data *data) { <------>WARN_ON(!skb_queue_empty(&data->drop_queue)); } static void net_dm_cpu_data_init(int cpu) { <------>struct per_cpu_dm_data *data; <------>data = &per_cpu(dm_cpu_data, cpu); <------>__net_dm_cpu_data_init(data); } static void net_dm_cpu_data_fini(int cpu) { <------>struct per_cpu_dm_data *data; <------>data = &per_cpu(dm_cpu_data, cpu); <------>/* At this point, we should have exclusive access <------> * to this struct and can free the skb inside it. <------> */ <------>consume_skb(data->skb); <------>__net_dm_cpu_data_fini(data); } static void net_dm_hw_cpu_data_init(int cpu) { <------>struct per_cpu_dm_data *hw_data; <------>hw_data = &per_cpu(dm_hw_cpu_data, cpu); <------>__net_dm_cpu_data_init(hw_data); } static void net_dm_hw_cpu_data_fini(int cpu) { <------>struct per_cpu_dm_data *hw_data; <------>hw_data = &per_cpu(dm_hw_cpu_data, cpu); <------>kfree(hw_data->hw_entries); <------>__net_dm_cpu_data_fini(hw_data); } static int __init init_net_drop_monitor(void) { <------>int cpu, rc; <------>pr_info("Initializing network drop monitor service\n"); <------>if (sizeof(void *) > 8) { <------><------>pr_err("Unable to store program counters on this arch, Drop monitor failed\n"); <------><------>return -ENOSPC; <------>} <------>rc = genl_register_family(&net_drop_monitor_family); <------>if (rc) { <------><------>pr_err("Could not create drop monitor netlink family\n"); <------><------>return rc; <------>} <------>WARN_ON(net_drop_monitor_family.mcgrp_offset != NET_DM_GRP_ALERT); <------>rc = register_netdevice_notifier(&dropmon_net_notifier); <------>if (rc < 0) { <------><------>pr_crit("Failed to register netdevice notifier\n"); <------><------>goto out_unreg; <------>} <------>rc = 0; <------>for_each_possible_cpu(cpu) { <------><------>net_dm_cpu_data_init(cpu); <------><------>net_dm_hw_cpu_data_init(cpu); <------>} <------>goto out; out_unreg: <------>genl_unregister_family(&net_drop_monitor_family); out: <------>return rc; } static void exit_net_drop_monitor(void) { <------>int cpu; <------>BUG_ON(unregister_netdevice_notifier(&dropmon_net_notifier)); <------>/* <------> * Because of the module_get/put we do in the trace state change path <------> * we are guarnateed not to have any current users when we get here <------> */ <------>for_each_possible_cpu(cpu) { <------><------>net_dm_hw_cpu_data_fini(cpu); <------><------>net_dm_cpu_data_fini(cpu); <------>} <------>BUG_ON(genl_unregister_family(&net_drop_monitor_family)); } module_init(init_net_drop_monitor); module_exit(exit_net_drop_monitor); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Neil Horman <nhorman@tuxdriver.com>"); MODULE_ALIAS_GENL_FAMILY("NET_DM"); MODULE_DESCRIPTION("Monitoring code for network dropped packet alerts");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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