From da58f90f11f597520f226caff1d3cfc115abedc9 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Sat, 17 Aug 2019 16:28:20 +0300 Subject: netdevsim: Add devlink-trap support Have netdevsim register its trap groups and traps with devlink during initialization and periodically report trapped packets to devlink core. Since netdevsim is not a real device, the trapped packets are emulated using a workqueue that periodically reports a UDP packet with a random 5-tuple from each active packet trap and from each running netdev. Signed-off-by: Ido Schimmel Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- drivers/net/netdevsim/dev.c | 279 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 278 insertions(+), 1 deletion(-) (limited to 'drivers/net/netdevsim/dev.c') diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c index a570da406d1d..d07bbf0ab627 100644 --- a/drivers/net/netdevsim/dev.c +++ b/drivers/net/netdevsim/dev.c @@ -17,11 +17,20 @@ #include #include +#include +#include +#include +#include #include #include #include #include +#include #include +#include +#include +#include +#include #include "netdevsim.h" @@ -302,6 +311,215 @@ static void nsim_dev_dummy_region_exit(struct nsim_dev *nsim_dev) devlink_region_destroy(nsim_dev->dummy_region); } +struct nsim_trap_item { + void *trap_ctx; + enum devlink_trap_action action; +}; + +struct nsim_trap_data { + struct delayed_work trap_report_dw; + struct nsim_trap_item *trap_items_arr; + struct nsim_dev *nsim_dev; + spinlock_t trap_lock; /* Protects trap_items_arr */ +}; + +enum { + NSIM_TRAP_ID_BASE = DEVLINK_TRAP_GENERIC_ID_MAX, + NSIM_TRAP_ID_FID_MISS, +}; + +#define NSIM_TRAP_NAME_FID_MISS "fid_miss" + +#define NSIM_TRAP_METADATA DEVLINK_TRAP_METADATA_TYPE_F_IN_PORT + +#define NSIM_TRAP_DROP(_id, _group_id) \ + DEVLINK_TRAP_GENERIC(DROP, DROP, _id, \ + DEVLINK_TRAP_GROUP_GENERIC(_group_id), \ + NSIM_TRAP_METADATA) +#define NSIM_TRAP_EXCEPTION(_id, _group_id) \ + DEVLINK_TRAP_GENERIC(EXCEPTION, TRAP, _id, \ + DEVLINK_TRAP_GROUP_GENERIC(_group_id), \ + NSIM_TRAP_METADATA) +#define NSIM_TRAP_DRIVER_EXCEPTION(_id, _group_id) \ + DEVLINK_TRAP_DRIVER(EXCEPTION, TRAP, NSIM_TRAP_ID_##_id, \ + NSIM_TRAP_NAME_##_id, \ + DEVLINK_TRAP_GROUP_GENERIC(_group_id), \ + NSIM_TRAP_METADATA) + +static const struct devlink_trap nsim_traps_arr[] = { + NSIM_TRAP_DROP(SMAC_MC, L2_DROPS), + NSIM_TRAP_DROP(VLAN_TAG_MISMATCH, L2_DROPS), + NSIM_TRAP_DROP(INGRESS_VLAN_FILTER, L2_DROPS), + NSIM_TRAP_DROP(INGRESS_STP_FILTER, L2_DROPS), + NSIM_TRAP_DROP(EMPTY_TX_LIST, L2_DROPS), + NSIM_TRAP_DROP(PORT_LOOPBACK_FILTER, L2_DROPS), + NSIM_TRAP_DRIVER_EXCEPTION(FID_MISS, L2_DROPS), + NSIM_TRAP_DROP(BLACKHOLE_ROUTE, L3_DROPS), + NSIM_TRAP_EXCEPTION(TTL_ERROR, L3_DROPS), + NSIM_TRAP_DROP(TAIL_DROP, BUFFER_DROPS), +}; + +#define NSIM_TRAP_L4_DATA_LEN 100 + +static struct sk_buff *nsim_dev_trap_skb_build(void) +{ + int tot_len, data_len = NSIM_TRAP_L4_DATA_LEN; + struct sk_buff *skb; + struct udphdr *udph; + struct ethhdr *eth; + struct iphdr *iph; + + skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC); + if (!skb) + return NULL; + tot_len = sizeof(struct iphdr) + sizeof(struct udphdr) + data_len; + + eth = skb_put(skb, sizeof(struct ethhdr)); + eth_random_addr(eth->h_dest); + eth_random_addr(eth->h_source); + eth->h_proto = htons(ETH_P_IP); + skb->protocol = htons(ETH_P_IP); + + iph = skb_put(skb, sizeof(struct iphdr)); + iph->protocol = IPPROTO_UDP; + iph->saddr = in_aton("192.0.2.1"); + iph->daddr = in_aton("198.51.100.1"); + iph->version = 0x4; + iph->frag_off = 0; + iph->ihl = 0x5; + iph->tot_len = htons(tot_len); + iph->ttl = 100; + ip_send_check(iph); + + udph = skb_put_zero(skb, sizeof(struct udphdr) + data_len); + get_random_bytes(&udph->source, sizeof(u16)); + get_random_bytes(&udph->dest, sizeof(u16)); + udph->len = htons(sizeof(struct udphdr) + data_len); + + return skb; +} + +static void nsim_dev_trap_report(struct nsim_dev_port *nsim_dev_port) +{ + struct nsim_dev *nsim_dev = nsim_dev_port->ns->nsim_dev; + struct devlink *devlink = priv_to_devlink(nsim_dev); + struct nsim_trap_data *nsim_trap_data; + int i; + + nsim_trap_data = nsim_dev->trap_data; + + spin_lock(&nsim_trap_data->trap_lock); + for (i = 0; i < ARRAY_SIZE(nsim_traps_arr); i++) { + struct nsim_trap_item *nsim_trap_item; + struct sk_buff *skb; + + nsim_trap_item = &nsim_trap_data->trap_items_arr[i]; + if (nsim_trap_item->action == DEVLINK_TRAP_ACTION_DROP) + continue; + + skb = nsim_dev_trap_skb_build(); + if (!skb) + continue; + skb->dev = nsim_dev_port->ns->netdev; + + /* Trapped packets are usually passed to devlink in softIRQ, + * but in this case they are generated in a workqueue. Disable + * softIRQs to prevent lockdep from complaining about + * "incosistent lock state". + */ + local_bh_disable(); + devlink_trap_report(devlink, skb, nsim_trap_item->trap_ctx, + &nsim_dev_port->devlink_port); + local_bh_enable(); + consume_skb(skb); + } + spin_unlock(&nsim_trap_data->trap_lock); +} + +#define NSIM_TRAP_REPORT_INTERVAL_MS 100 + +static void nsim_dev_trap_report_work(struct work_struct *work) +{ + struct nsim_trap_data *nsim_trap_data; + struct nsim_dev_port *nsim_dev_port; + struct nsim_dev *nsim_dev; + + nsim_trap_data = container_of(work, struct nsim_trap_data, + trap_report_dw.work); + nsim_dev = nsim_trap_data->nsim_dev; + + /* For each running port and enabled packet trap, generate a UDP + * packet with a random 5-tuple and report it. + */ + mutex_lock(&nsim_dev->port_list_lock); + list_for_each_entry(nsim_dev_port, &nsim_dev->port_list, list) { + if (!netif_running(nsim_dev_port->ns->netdev)) + continue; + + nsim_dev_trap_report(nsim_dev_port); + } + mutex_unlock(&nsim_dev->port_list_lock); + + schedule_delayed_work(&nsim_dev->trap_data->trap_report_dw, + msecs_to_jiffies(NSIM_TRAP_REPORT_INTERVAL_MS)); +} + +static int nsim_dev_traps_init(struct devlink *devlink) +{ + struct nsim_dev *nsim_dev = devlink_priv(devlink); + struct nsim_trap_data *nsim_trap_data; + int err; + + nsim_trap_data = kzalloc(sizeof(*nsim_trap_data), GFP_KERNEL); + if (!nsim_trap_data) + return -ENOMEM; + + nsim_trap_data->trap_items_arr = kcalloc(ARRAY_SIZE(nsim_traps_arr), + sizeof(struct nsim_trap_item), + GFP_KERNEL); + if (!nsim_trap_data->trap_items_arr) { + err = -ENOMEM; + goto err_trap_data_free; + } + + /* The lock is used to protect the action state of the registered + * traps. The value is written by user and read in delayed work when + * iterating over all the traps. + */ + spin_lock_init(&nsim_trap_data->trap_lock); + nsim_trap_data->nsim_dev = nsim_dev; + nsim_dev->trap_data = nsim_trap_data; + + err = devlink_traps_register(devlink, nsim_traps_arr, + ARRAY_SIZE(nsim_traps_arr), NULL); + if (err) + goto err_trap_items_free; + + INIT_DELAYED_WORK(&nsim_dev->trap_data->trap_report_dw, + nsim_dev_trap_report_work); + schedule_delayed_work(&nsim_dev->trap_data->trap_report_dw, + msecs_to_jiffies(NSIM_TRAP_REPORT_INTERVAL_MS)); + + return 0; + +err_trap_items_free: + kfree(nsim_trap_data->trap_items_arr); +err_trap_data_free: + kfree(nsim_trap_data); + return err; +} + +static void nsim_dev_traps_exit(struct devlink *devlink) +{ + struct nsim_dev *nsim_dev = devlink_priv(devlink); + + cancel_delayed_work_sync(&nsim_dev->trap_data->trap_report_dw); + devlink_traps_unregister(devlink, nsim_traps_arr, + ARRAY_SIZE(nsim_traps_arr)); + kfree(nsim_dev->trap_data->trap_items_arr); + kfree(nsim_dev->trap_data); +} + static int nsim_dev_reload(struct devlink *devlink, struct netlink_ext_ack *extack) { @@ -369,9 +587,61 @@ static int nsim_dev_flash_update(struct devlink *devlink, const char *file_name, return 0; } +static struct nsim_trap_item * +nsim_dev_trap_item_lookup(struct nsim_dev *nsim_dev, u16 trap_id) +{ + struct nsim_trap_data *nsim_trap_data = nsim_dev->trap_data; + int i; + + for (i = 0; i < ARRAY_SIZE(nsim_traps_arr); i++) { + if (nsim_traps_arr[i].id == trap_id) + return &nsim_trap_data->trap_items_arr[i]; + } + + return NULL; +} + +static int nsim_dev_devlink_trap_init(struct devlink *devlink, + const struct devlink_trap *trap, + void *trap_ctx) +{ + struct nsim_dev *nsim_dev = devlink_priv(devlink); + struct nsim_trap_item *nsim_trap_item; + + nsim_trap_item = nsim_dev_trap_item_lookup(nsim_dev, trap->id); + if (WARN_ON(!nsim_trap_item)) + return -ENOENT; + + nsim_trap_item->trap_ctx = trap_ctx; + nsim_trap_item->action = trap->init_action; + + return 0; +} + +static int +nsim_dev_devlink_trap_action_set(struct devlink *devlink, + const struct devlink_trap *trap, + enum devlink_trap_action action) +{ + struct nsim_dev *nsim_dev = devlink_priv(devlink); + struct nsim_trap_item *nsim_trap_item; + + nsim_trap_item = nsim_dev_trap_item_lookup(nsim_dev, trap->id); + if (WARN_ON(!nsim_trap_item)) + return -ENOENT; + + spin_lock(&nsim_dev->trap_data->trap_lock); + nsim_trap_item->action = action; + spin_unlock(&nsim_dev->trap_data->trap_lock); + + return 0; +} + static const struct devlink_ops nsim_dev_devlink_ops = { .reload = nsim_dev_reload, .flash_update = nsim_dev_flash_update, + .trap_init = nsim_dev_devlink_trap_init, + .trap_action_set = nsim_dev_devlink_trap_action_set, }; #define NSIM_DEV_MAX_MACS_DEFAULT 32 @@ -421,10 +691,14 @@ nsim_dev_create(struct nsim_bus_dev *nsim_bus_dev, unsigned int port_count) if (err) goto err_params_unregister; - err = nsim_dev_debugfs_init(nsim_dev); + err = nsim_dev_traps_init(devlink); if (err) goto err_dummy_region_exit; + err = nsim_dev_debugfs_init(nsim_dev); + if (err) + goto err_traps_exit; + err = nsim_bpf_dev_init(nsim_dev); if (err) goto err_debugfs_exit; @@ -434,6 +708,8 @@ nsim_dev_create(struct nsim_bus_dev *nsim_bus_dev, unsigned int port_count) err_debugfs_exit: nsim_dev_debugfs_exit(nsim_dev); +err_traps_exit: + nsim_dev_traps_exit(devlink); err_dummy_region_exit: nsim_dev_dummy_region_exit(nsim_dev); err_params_unregister: @@ -456,6 +732,7 @@ static void nsim_dev_destroy(struct nsim_dev *nsim_dev) nsim_bpf_dev_exit(nsim_dev); nsim_dev_debugfs_exit(nsim_dev); + nsim_dev_traps_exit(devlink); nsim_dev_dummy_region_exit(nsim_dev); devlink_params_unregister(devlink, nsim_devlink_params, ARRAY_SIZE(nsim_devlink_params)); -- cgit v1.2.3 From 9e087457048884c57c51a32b52d8aa1d9b0d7385 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Sat, 17 Aug 2019 16:28:21 +0300 Subject: Documentation: Add description of netdevsim traps Signed-off-by: Ido Schimmel Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- Documentation/networking/devlink-trap-netdevsim.rst | 20 ++++++++++++++++++++ Documentation/networking/devlink-trap.rst | 11 +++++++++++ Documentation/networking/index.rst | 1 + drivers/net/netdevsim/dev.c | 3 +++ 4 files changed, 35 insertions(+) create mode 100644 Documentation/networking/devlink-trap-netdevsim.rst (limited to 'drivers/net/netdevsim/dev.c') diff --git a/Documentation/networking/devlink-trap-netdevsim.rst b/Documentation/networking/devlink-trap-netdevsim.rst new file mode 100644 index 000000000000..b721c9415473 --- /dev/null +++ b/Documentation/networking/devlink-trap-netdevsim.rst @@ -0,0 +1,20 @@ +.. SPDX-License-Identifier: GPL-2.0 + +====================== +Devlink Trap netdevsim +====================== + +Driver-specific Traps +===================== + +.. list-table:: List of Driver-specific Traps Registered by ``netdevsim`` + :widths: 5 5 90 + + * - Name + - Type + - Description + * - ``fid_miss`` + - ``exception`` + - When a packet enters the device it is classified to a filtering + indentifier (FID) based on the ingress port and VLAN. This trap is used + to trap packets for which a FID could not be found diff --git a/Documentation/networking/devlink-trap.rst b/Documentation/networking/devlink-trap.rst index dbc7a3e00fd8..fe4f6e149623 100644 --- a/Documentation/networking/devlink-trap.rst +++ b/Documentation/networking/devlink-trap.rst @@ -162,6 +162,17 @@ be added to the following table: - Traps packets that the device decided to drop because they could not be enqueued to a transmission queue which is full +Driver-specific Packet Traps +============================ + +Device drivers can register driver-specific packet traps, but these must be +clearly documented. Such traps can correspond to device-specific exceptions and +help debug packet drops caused by these exceptions. The following list includes +links to the description of driver-specific traps registered by various device +drivers: + + * :doc:`/devlink-trap-netdevsim` + Generic Packet Trap Groups ========================== diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst index 86a814e4d450..37eabc17894c 100644 --- a/Documentation/networking/index.rst +++ b/Documentation/networking/index.rst @@ -15,6 +15,7 @@ Contents: dsa/index devlink-info-versions devlink-trap + devlink-trap-netdevsim ieee802154 kapi z8530book diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c index d07bbf0ab627..c217049552f7 100644 --- a/drivers/net/netdevsim/dev.c +++ b/drivers/net/netdevsim/dev.c @@ -323,6 +323,9 @@ struct nsim_trap_data { spinlock_t trap_lock; /* Protects trap_items_arr */ }; +/* All driver-specific traps must be documented in + * Documentation/networking/devlink-trap-netdevsim.rst + */ enum { NSIM_TRAP_ID_BASE = DEVLINK_TRAP_GENERIC_ID_MAX, NSIM_TRAP_ID_FID_MISS, -- cgit v1.2.3