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-rw-r--r--net/psample/psample.c473
1 files changed, 473 insertions, 0 deletions
diff --git a/net/psample/psample.c b/net/psample/psample.c
new file mode 100644
index 000000000..5913da77c
--- /dev/null
+++ b/net/psample/psample.c
@@ -0,0 +1,473 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * net/psample/psample.c - Netlink channel for packet sampling
+ * Copyright (c) 2017 Yotam Gigi <yotamg@mellanox.com>
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/module.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+#include <net/netlink.h>
+#include <net/genetlink.h>
+#include <net/psample.h>
+#include <linux/spinlock.h>
+#include <net/ip_tunnels.h>
+#include <net/dst_metadata.h>
+
+#define PSAMPLE_MAX_PACKET_SIZE 0xffff
+
+static LIST_HEAD(psample_groups_list);
+static DEFINE_SPINLOCK(psample_groups_lock);
+
+/* multicast groups */
+enum psample_nl_multicast_groups {
+ PSAMPLE_NL_MCGRP_CONFIG,
+ PSAMPLE_NL_MCGRP_SAMPLE,
+};
+
+static const struct genl_multicast_group psample_nl_mcgrps[] = {
+ [PSAMPLE_NL_MCGRP_CONFIG] = { .name = PSAMPLE_NL_MCGRP_CONFIG_NAME },
+ [PSAMPLE_NL_MCGRP_SAMPLE] = { .name = PSAMPLE_NL_MCGRP_SAMPLE_NAME,
+ .flags = GENL_UNS_ADMIN_PERM },
+};
+
+static struct genl_family psample_nl_family __ro_after_init;
+
+static int psample_group_nl_fill(struct sk_buff *msg,
+ struct psample_group *group,
+ enum psample_command cmd, u32 portid, u32 seq,
+ int flags)
+{
+ void *hdr;
+ int ret;
+
+ hdr = genlmsg_put(msg, portid, seq, &psample_nl_family, flags, cmd);
+ if (!hdr)
+ return -EMSGSIZE;
+
+ ret = nla_put_u32(msg, PSAMPLE_ATTR_SAMPLE_GROUP, group->group_num);
+ if (ret < 0)
+ goto error;
+
+ ret = nla_put_u32(msg, PSAMPLE_ATTR_GROUP_REFCOUNT, group->refcount);
+ if (ret < 0)
+ goto error;
+
+ ret = nla_put_u32(msg, PSAMPLE_ATTR_GROUP_SEQ, group->seq);
+ if (ret < 0)
+ goto error;
+
+ genlmsg_end(msg, hdr);
+ return 0;
+
+error:
+ genlmsg_cancel(msg, hdr);
+ return -EMSGSIZE;
+}
+
+static int psample_nl_cmd_get_group_dumpit(struct sk_buff *msg,
+ struct netlink_callback *cb)
+{
+ struct psample_group *group;
+ int start = cb->args[0];
+ int idx = 0;
+ int err;
+
+ spin_lock_bh(&psample_groups_lock);
+ list_for_each_entry(group, &psample_groups_list, list) {
+ if (!net_eq(group->net, sock_net(msg->sk)))
+ continue;
+ if (idx < start) {
+ idx++;
+ continue;
+ }
+ err = psample_group_nl_fill(msg, group, PSAMPLE_CMD_NEW_GROUP,
+ NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq, NLM_F_MULTI);
+ if (err)
+ break;
+ idx++;
+ }
+
+ spin_unlock_bh(&psample_groups_lock);
+ cb->args[0] = idx;
+ return msg->len;
+}
+
+static const struct genl_small_ops psample_nl_ops[] = {
+ {
+ .cmd = PSAMPLE_CMD_GET_GROUP,
+ .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+ .dumpit = psample_nl_cmd_get_group_dumpit,
+ /* can be retrieved by unprivileged users */
+ }
+};
+
+static struct genl_family psample_nl_family __ro_after_init = {
+ .name = PSAMPLE_GENL_NAME,
+ .version = PSAMPLE_GENL_VERSION,
+ .maxattr = PSAMPLE_ATTR_MAX,
+ .netnsok = true,
+ .module = THIS_MODULE,
+ .mcgrps = psample_nl_mcgrps,
+ .small_ops = psample_nl_ops,
+ .n_small_ops = ARRAY_SIZE(psample_nl_ops),
+ .n_mcgrps = ARRAY_SIZE(psample_nl_mcgrps),
+};
+
+static void psample_group_notify(struct psample_group *group,
+ enum psample_command cmd)
+{
+ struct sk_buff *msg;
+ int err;
+
+ msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
+ if (!msg)
+ return;
+
+ err = psample_group_nl_fill(msg, group, cmd, 0, 0, NLM_F_MULTI);
+ if (!err)
+ genlmsg_multicast_netns(&psample_nl_family, group->net, msg, 0,
+ PSAMPLE_NL_MCGRP_CONFIG, GFP_ATOMIC);
+ else
+ nlmsg_free(msg);
+}
+
+static struct psample_group *psample_group_create(struct net *net,
+ u32 group_num)
+{
+ struct psample_group *group;
+
+ group = kzalloc(sizeof(*group), GFP_ATOMIC);
+ if (!group)
+ return NULL;
+
+ group->net = net;
+ group->group_num = group_num;
+ list_add_tail(&group->list, &psample_groups_list);
+
+ psample_group_notify(group, PSAMPLE_CMD_NEW_GROUP);
+ return group;
+}
+
+static void psample_group_destroy(struct psample_group *group)
+{
+ psample_group_notify(group, PSAMPLE_CMD_DEL_GROUP);
+ list_del(&group->list);
+ kfree_rcu(group, rcu);
+}
+
+static struct psample_group *
+psample_group_lookup(struct net *net, u32 group_num)
+{
+ struct psample_group *group;
+
+ list_for_each_entry(group, &psample_groups_list, list)
+ if ((group->group_num == group_num) && (group->net == net))
+ return group;
+ return NULL;
+}
+
+struct psample_group *psample_group_get(struct net *net, u32 group_num)
+{
+ struct psample_group *group;
+
+ spin_lock_bh(&psample_groups_lock);
+
+ group = psample_group_lookup(net, group_num);
+ if (!group) {
+ group = psample_group_create(net, group_num);
+ if (!group)
+ goto out;
+ }
+ group->refcount++;
+
+out:
+ spin_unlock_bh(&psample_groups_lock);
+ return group;
+}
+EXPORT_SYMBOL_GPL(psample_group_get);
+
+void psample_group_take(struct psample_group *group)
+{
+ spin_lock_bh(&psample_groups_lock);
+ group->refcount++;
+ spin_unlock_bh(&psample_groups_lock);
+}
+EXPORT_SYMBOL_GPL(psample_group_take);
+
+void psample_group_put(struct psample_group *group)
+{
+ spin_lock_bh(&psample_groups_lock);
+
+ if (--group->refcount == 0)
+ psample_group_destroy(group);
+
+ spin_unlock_bh(&psample_groups_lock);
+}
+EXPORT_SYMBOL_GPL(psample_group_put);
+
+#ifdef CONFIG_INET
+static int __psample_ip_tun_to_nlattr(struct sk_buff *skb,
+ struct ip_tunnel_info *tun_info)
+{
+ unsigned short tun_proto = ip_tunnel_info_af(tun_info);
+ const void *tun_opts = ip_tunnel_info_opts(tun_info);
+ const struct ip_tunnel_key *tun_key = &tun_info->key;
+ int tun_opts_len = tun_info->options_len;
+
+ if (tun_key->tun_flags & TUNNEL_KEY &&
+ nla_put_be64(skb, PSAMPLE_TUNNEL_KEY_ATTR_ID, tun_key->tun_id,
+ PSAMPLE_TUNNEL_KEY_ATTR_PAD))
+ return -EMSGSIZE;
+
+ if (tun_info->mode & IP_TUNNEL_INFO_BRIDGE &&
+ nla_put_flag(skb, PSAMPLE_TUNNEL_KEY_ATTR_IPV4_INFO_BRIDGE))
+ return -EMSGSIZE;
+
+ switch (tun_proto) {
+ case AF_INET:
+ if (tun_key->u.ipv4.src &&
+ nla_put_in_addr(skb, PSAMPLE_TUNNEL_KEY_ATTR_IPV4_SRC,
+ tun_key->u.ipv4.src))
+ return -EMSGSIZE;
+ if (tun_key->u.ipv4.dst &&
+ nla_put_in_addr(skb, PSAMPLE_TUNNEL_KEY_ATTR_IPV4_DST,
+ tun_key->u.ipv4.dst))
+ return -EMSGSIZE;
+ break;
+ case AF_INET6:
+ if (!ipv6_addr_any(&tun_key->u.ipv6.src) &&
+ nla_put_in6_addr(skb, PSAMPLE_TUNNEL_KEY_ATTR_IPV6_SRC,
+ &tun_key->u.ipv6.src))
+ return -EMSGSIZE;
+ if (!ipv6_addr_any(&tun_key->u.ipv6.dst) &&
+ nla_put_in6_addr(skb, PSAMPLE_TUNNEL_KEY_ATTR_IPV6_DST,
+ &tun_key->u.ipv6.dst))
+ return -EMSGSIZE;
+ break;
+ }
+ if (tun_key->tos &&
+ nla_put_u8(skb, PSAMPLE_TUNNEL_KEY_ATTR_TOS, tun_key->tos))
+ return -EMSGSIZE;
+ if (nla_put_u8(skb, PSAMPLE_TUNNEL_KEY_ATTR_TTL, tun_key->ttl))
+ return -EMSGSIZE;
+ if ((tun_key->tun_flags & TUNNEL_DONT_FRAGMENT) &&
+ nla_put_flag(skb, PSAMPLE_TUNNEL_KEY_ATTR_DONT_FRAGMENT))
+ return -EMSGSIZE;
+ if ((tun_key->tun_flags & TUNNEL_CSUM) &&
+ nla_put_flag(skb, PSAMPLE_TUNNEL_KEY_ATTR_CSUM))
+ return -EMSGSIZE;
+ if (tun_key->tp_src &&
+ nla_put_be16(skb, PSAMPLE_TUNNEL_KEY_ATTR_TP_SRC, tun_key->tp_src))
+ return -EMSGSIZE;
+ if (tun_key->tp_dst &&
+ nla_put_be16(skb, PSAMPLE_TUNNEL_KEY_ATTR_TP_DST, tun_key->tp_dst))
+ return -EMSGSIZE;
+ if ((tun_key->tun_flags & TUNNEL_OAM) &&
+ nla_put_flag(skb, PSAMPLE_TUNNEL_KEY_ATTR_OAM))
+ return -EMSGSIZE;
+ if (tun_opts_len) {
+ if (tun_key->tun_flags & TUNNEL_GENEVE_OPT &&
+ nla_put(skb, PSAMPLE_TUNNEL_KEY_ATTR_GENEVE_OPTS,
+ tun_opts_len, tun_opts))
+ return -EMSGSIZE;
+ else if (tun_key->tun_flags & TUNNEL_ERSPAN_OPT &&
+ nla_put(skb, PSAMPLE_TUNNEL_KEY_ATTR_ERSPAN_OPTS,
+ tun_opts_len, tun_opts))
+ return -EMSGSIZE;
+ }
+
+ return 0;
+}
+
+static int psample_ip_tun_to_nlattr(struct sk_buff *skb,
+ struct ip_tunnel_info *tun_info)
+{
+ struct nlattr *nla;
+ int err;
+
+ nla = nla_nest_start_noflag(skb, PSAMPLE_ATTR_TUNNEL);
+ if (!nla)
+ return -EMSGSIZE;
+
+ err = __psample_ip_tun_to_nlattr(skb, tun_info);
+ if (err) {
+ nla_nest_cancel(skb, nla);
+ return err;
+ }
+
+ nla_nest_end(skb, nla);
+
+ return 0;
+}
+
+static int psample_tunnel_meta_len(struct ip_tunnel_info *tun_info)
+{
+ unsigned short tun_proto = ip_tunnel_info_af(tun_info);
+ const struct ip_tunnel_key *tun_key = &tun_info->key;
+ int tun_opts_len = tun_info->options_len;
+ int sum = nla_total_size(0); /* PSAMPLE_ATTR_TUNNEL */
+
+ if (tun_key->tun_flags & TUNNEL_KEY)
+ sum += nla_total_size_64bit(sizeof(u64));
+
+ if (tun_info->mode & IP_TUNNEL_INFO_BRIDGE)
+ sum += nla_total_size(0);
+
+ switch (tun_proto) {
+ case AF_INET:
+ if (tun_key->u.ipv4.src)
+ sum += nla_total_size(sizeof(u32));
+ if (tun_key->u.ipv4.dst)
+ sum += nla_total_size(sizeof(u32));
+ break;
+ case AF_INET6:
+ if (!ipv6_addr_any(&tun_key->u.ipv6.src))
+ sum += nla_total_size(sizeof(struct in6_addr));
+ if (!ipv6_addr_any(&tun_key->u.ipv6.dst))
+ sum += nla_total_size(sizeof(struct in6_addr));
+ break;
+ }
+ if (tun_key->tos)
+ sum += nla_total_size(sizeof(u8));
+ sum += nla_total_size(sizeof(u8)); /* TTL */
+ if (tun_key->tun_flags & TUNNEL_DONT_FRAGMENT)
+ sum += nla_total_size(0);
+ if (tun_key->tun_flags & TUNNEL_CSUM)
+ sum += nla_total_size(0);
+ if (tun_key->tp_src)
+ sum += nla_total_size(sizeof(u16));
+ if (tun_key->tp_dst)
+ sum += nla_total_size(sizeof(u16));
+ if (tun_key->tun_flags & TUNNEL_OAM)
+ sum += nla_total_size(0);
+ if (tun_opts_len) {
+ if (tun_key->tun_flags & TUNNEL_GENEVE_OPT)
+ sum += nla_total_size(tun_opts_len);
+ else if (tun_key->tun_flags & TUNNEL_ERSPAN_OPT)
+ sum += nla_total_size(tun_opts_len);
+ }
+
+ return sum;
+}
+#endif
+
+void psample_sample_packet(struct psample_group *group, struct sk_buff *skb,
+ u32 trunc_size, int in_ifindex, int out_ifindex,
+ u32 sample_rate)
+{
+#ifdef CONFIG_INET
+ struct ip_tunnel_info *tun_info;
+#endif
+ struct sk_buff *nl_skb;
+ int data_len;
+ int meta_len;
+ void *data;
+ int ret;
+
+ meta_len = (in_ifindex ? nla_total_size(sizeof(u16)) : 0) +
+ (out_ifindex ? nla_total_size(sizeof(u16)) : 0) +
+ nla_total_size(sizeof(u32)) + /* sample_rate */
+ nla_total_size(sizeof(u32)) + /* orig_size */
+ nla_total_size(sizeof(u32)) + /* group_num */
+ nla_total_size(sizeof(u32)); /* seq */
+
+#ifdef CONFIG_INET
+ tun_info = skb_tunnel_info(skb);
+ if (tun_info)
+ meta_len += psample_tunnel_meta_len(tun_info);
+#endif
+
+ data_len = min(skb->len, trunc_size);
+ if (meta_len + nla_total_size(data_len) > PSAMPLE_MAX_PACKET_SIZE)
+ data_len = PSAMPLE_MAX_PACKET_SIZE - meta_len - NLA_HDRLEN
+ - NLA_ALIGNTO;
+
+ nl_skb = genlmsg_new(meta_len + nla_total_size(data_len), GFP_ATOMIC);
+ if (unlikely(!nl_skb))
+ return;
+
+ data = genlmsg_put(nl_skb, 0, 0, &psample_nl_family, 0,
+ PSAMPLE_CMD_SAMPLE);
+ if (unlikely(!data))
+ goto error;
+
+ if (in_ifindex) {
+ ret = nla_put_u16(nl_skb, PSAMPLE_ATTR_IIFINDEX, in_ifindex);
+ if (unlikely(ret < 0))
+ goto error;
+ }
+
+ if (out_ifindex) {
+ ret = nla_put_u16(nl_skb, PSAMPLE_ATTR_OIFINDEX, out_ifindex);
+ if (unlikely(ret < 0))
+ goto error;
+ }
+
+ ret = nla_put_u32(nl_skb, PSAMPLE_ATTR_SAMPLE_RATE, sample_rate);
+ if (unlikely(ret < 0))
+ goto error;
+
+ ret = nla_put_u32(nl_skb, PSAMPLE_ATTR_ORIGSIZE, skb->len);
+ if (unlikely(ret < 0))
+ goto error;
+
+ ret = nla_put_u32(nl_skb, PSAMPLE_ATTR_SAMPLE_GROUP, group->group_num);
+ if (unlikely(ret < 0))
+ goto error;
+
+ ret = nla_put_u32(nl_skb, PSAMPLE_ATTR_GROUP_SEQ, group->seq++);
+ if (unlikely(ret < 0))
+ goto error;
+
+ if (data_len) {
+ int nla_len = nla_total_size(data_len);
+ struct nlattr *nla;
+
+ nla = skb_put(nl_skb, nla_len);
+ nla->nla_type = PSAMPLE_ATTR_DATA;
+ nla->nla_len = nla_attr_size(data_len);
+
+ if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
+ goto error;
+ }
+
+#ifdef CONFIG_INET
+ if (tun_info) {
+ ret = psample_ip_tun_to_nlattr(nl_skb, tun_info);
+ if (unlikely(ret < 0))
+ goto error;
+ }
+#endif
+
+ genlmsg_end(nl_skb, data);
+ genlmsg_multicast_netns(&psample_nl_family, group->net, nl_skb, 0,
+ PSAMPLE_NL_MCGRP_SAMPLE, GFP_ATOMIC);
+
+ return;
+error:
+ pr_err_ratelimited("Could not create psample log message\n");
+ nlmsg_free(nl_skb);
+}
+EXPORT_SYMBOL_GPL(psample_sample_packet);
+
+static int __init psample_module_init(void)
+{
+ return genl_register_family(&psample_nl_family);
+}
+
+static void __exit psample_module_exit(void)
+{
+ genl_unregister_family(&psample_nl_family);
+}
+
+module_init(psample_module_init);
+module_exit(psample_module_exit);
+
+MODULE_AUTHOR("Yotam Gigi <yotam.gi@gmail.com>");
+MODULE_DESCRIPTION("netlink channel for packet sampling");
+MODULE_LICENSE("GPL v2");