| // 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, |
| enum skb_drop_reason reason); |
| 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, |
| enum skb_drop_reason reason) |
| { |
| 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]; |
| strscpy(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, |
| enum skb_drop_reason reason) |
| { |
| 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; |
| 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) |
| { |
| 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 guaranteed 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"); |