diff options
Diffstat (limited to 'net/core/drop_monitor.c')
| -rw-r--r-- | net/core/drop_monitor.c | 1339 |
1 files changed, 1279 insertions, 60 deletions
diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index 4ea4347f5062..cc60cc22e2db 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -26,6 +26,7 @@ #include <linux/bitops.h> #include <linux/slab.h> #include <linux/module.h> +#include <net/drop_monitor.h> #include <net/genetlink.h> #include <net/netevent.h> @@ -43,13 +44,44 @@ * netlink alerts */ static int trace_state = TRACE_OFF; -static DEFINE_MUTEX(trace_state_mutex); +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[0]; +}; struct per_cpu_dm_data { - spinlock_t lock; - struct sk_buff *skb; + 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 { @@ -63,12 +95,37 @@ struct dm_hw_stat_delta { 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_probe)(struct sk_buff *skb, + const struct net_dm_hw_metadata *hw_metadata); +}; + +struct net_dm_skb_cb { + union { + struct net_dm_hw_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; @@ -235,48 +292,838 @@ static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi, rcu_read_unlock(); } -static int set_all_monitor_traces(int state) +static struct net_dm_hw_entries * +net_dm_hw_reset_per_cpu_data(struct per_cpu_dm_data *hw_data) { - int rc = 0; - struct dm_hw_stat_delta *new_stat = NULL; - struct dm_hw_stat_delta *temp; + 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); + } - mutex_lock(&trace_state_mutex); + spin_lock_irqsave(&hw_data->lock, flags); + swap(hw_data->hw_entries, hw_entries); + spin_unlock_irqrestore(&hw_data->lock, flags); - if (state == trace_state) { - rc = -EAGAIN; - goto out_unlock; + 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; } - switch (state) { - case TRACE_ON: - if (!try_module_get(THIS_MODULE)) { - rc = -ENODEV; - break; + 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_summary_probe(struct sk_buff *skb, + const struct net_dm_hw_metadata *hw_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; + + 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, hw_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; - rc |= register_trace_kfree_skb(trace_kfree_skb_hit, NULL); - rc |= register_trace_napi_poll(trace_napi_poll_hit, NULL); - break; + hw_entry = &hw_entries->entries[hw_entries->num_entries]; + strlcpy(hw_entry->trap_name, hw_metadata->trap_name, + NET_DM_MAX_HW_TRAP_NAME_LEN - 1); + hw_entry->count = 1; + hw_entries->num_entries++; - case TRACE_OFF: - rc |= unregister_trace_kfree_skb(trace_kfree_skb_hit, NULL); - rc |= unregister_trace_napi_poll(trace_napi_poll_hit, NULL); + if (!timer_pending(&hw_data->send_timer)) { + hw_data->send_timer.expires = jiffies + dm_delay * HZ; + add_timer(&hw_data->send_timer); + } - tracepoint_synchronize_unregister(); +out: + spin_unlock_irqrestore(&hw_data->lock, flags); +} - /* - * Clean the device list +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_probe = net_dm_hw_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; + + 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_hw_packet_report_size(size_t payload_len, + const struct net_dm_hw_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_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 net_dm_hw_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 (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 net_dm_hw_metadata * +net_dm_hw_metadata_clone(const struct net_dm_hw_metadata *hw_metadata) +{ + struct net_dm_hw_metadata *n_hw_metadata; + const char *trap_group_name; + const char *trap_name; + + n_hw_metadata = kmalloc(sizeof(*hw_metadata), GFP_ATOMIC); + if (!n_hw_metadata) + return NULL; + + trap_group_name = kmemdup(hw_metadata->trap_group_name, + strlen(hw_metadata->trap_group_name) + 1, + GFP_ATOMIC | __GFP_ZERO); + if (!trap_group_name) + goto free_hw_metadata; + n_hw_metadata->trap_group_name = trap_group_name; + + trap_name = kmemdup(hw_metadata->trap_name, + strlen(hw_metadata->trap_name) + 1, + GFP_ATOMIC | __GFP_ZERO); + if (!trap_name) + goto free_trap_group; + n_hw_metadata->trap_name = trap_name; + + n_hw_metadata->input_dev = hw_metadata->input_dev; + if (n_hw_metadata->input_dev) + dev_hold(n_hw_metadata->input_dev); + + return n_hw_metadata; + +free_trap_group: + kfree(trap_group_name); +free_hw_metadata: + kfree(n_hw_metadata); + return NULL; +} + +static void +net_dm_hw_metadata_free(const struct net_dm_hw_metadata *hw_metadata) +{ + if (hw_metadata->input_dev) + dev_put(hw_metadata->input_dev); + 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 net_dm_hw_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_packet_probe(struct sk_buff *skb, + const struct net_dm_hw_metadata *hw_metadata) +{ + struct net_dm_hw_metadata *n_hw_metadata; + ktime_t tstamp = ktime_get_real(); + struct per_cpu_dm_data *hw_data; + struct sk_buff *nskb; + unsigned long flags; + + nskb = skb_clone(skb, GFP_ATOMIC); + if (!nskb) + return; + + n_hw_metadata = net_dm_hw_metadata_clone(hw_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_probe = net_dm_hw_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, +}; + +void net_dm_hw_report(struct sk_buff *skb, + const struct net_dm_hw_metadata *hw_metadata) +{ + rcu_read_lock(); + + if (!monitor_hw) + goto out; + + net_dm_alert_ops_arr[net_dm_alert_mode]->hw_probe(skb, hw_metadata); + +out: + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(net_dm_hw_report); + +static int net_dm_hw_monitor_start(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 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); + } + + monitor_hw = true; + + return 0; +} + +static void net_dm_hw_monitor_stop(struct netlink_ext_ack *extack) +{ + int cpu; + + if (!monitor_hw) + NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already disabled"); + + monitor_hw = false; + + /* After this call returns we are guaranteed that no CPU is processing + * any hardware drops. + */ + synchronize_rcu(); + + 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 net_dm_hw_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. */ - 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); - } + 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: + 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; - module_put(THIS_MODULE); + 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; @@ -288,30 +1135,331 @@ static int set_all_monitor_traces(int state) else rc = -EINPROGRESS; -out_unlock: - mutex_unlock(&trace_state_mutex); - 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: /* fall-through */ + 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) { - return -ENOTSUPP; + 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 set_all_monitor_traces(TRACE_ON); + return net_dm_monitor_start(set_sw, set_hw, extack); case NET_DM_CMD_STOP: - return set_all_monitor_traces(TRACE_OFF); + 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; - return -ENOTSUPP; +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, @@ -330,12 +1478,12 @@ static int dropmon_net_event(struct notifier_block *ev_block, new_stat->dev = dev; new_stat->last_rx = jiffies; - mutex_lock(&trace_state_mutex); + mutex_lock(&net_dm_mutex); list_add_rcu(&new_stat->list, &hw_stats_list); - mutex_unlock(&trace_state_mutex); + mutex_unlock(&net_dm_mutex); break; case NETDEV_UNREGISTER: - mutex_lock(&trace_state_mutex); + mutex_lock(&net_dm_mutex); list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) { if (new_stat->dev == dev) { new_stat->dev = NULL; @@ -346,18 +1494,28 @@ static int dropmon_net_event(struct notifier_block *ev_block, } } } - mutex_unlock(&trace_state_mutex); + 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_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, @@ -369,12 +1527,38 @@ static const struct genl_ops dropmon_ops[] = { .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, .ops = dropmon_ops, .n_ops = ARRAY_SIZE(dropmon_ops), @@ -386,9 +1570,57 @@ static struct notifier_block dropmon_net_notifier = { .notifier_call = dropmon_net_event }; -static int __init init_net_drop_monitor(void) +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"); @@ -414,14 +1646,10 @@ static int __init init_net_drop_monitor(void) rc = 0; for_each_possible_cpu(cpu) { - data = &per_cpu(dm_cpu_data, cpu); - INIT_WORK(&data->dm_alert_work, send_dm_alert); - timer_setup(&data->send_timer, sched_send_work, 0); - spin_lock_init(&data->lock); - reset_per_cpu_data(data); + net_dm_cpu_data_init(cpu); + net_dm_hw_cpu_data_init(cpu); } - goto out; out_unreg: @@ -432,7 +1660,6 @@ out: static void exit_net_drop_monitor(void) { - struct per_cpu_dm_data *data; int cpu; BUG_ON(unregister_netdevice_notifier(&dropmon_net_notifier)); @@ -440,19 +1667,11 @@ static void exit_net_drop_monitor(void) /* * 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 - * all we need to do is make sure that we don't have any running timers - * or pending schedule calls */ for_each_possible_cpu(cpu) { - data = &per_cpu(dm_cpu_data, cpu); - del_timer_sync(&data->send_timer); - cancel_work_sync(&data->dm_alert_work); - /* - * At this point, we should have exclusive access - * to this struct and can free the skb inside it - */ - kfree_skb(data->skb); + net_dm_hw_cpu_data_fini(cpu); + net_dm_cpu_data_fini(cpu); } BUG_ON(genl_unregister_family(&net_drop_monitor_family)); |