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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#include <linux/types.h>#include <linux/kernel.h>#include <linux/skbuff.h>#include <linux/module.h>#include <linux/timekeeping.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_MCAST_CAP_NET_ADMIN, },};
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), .resv_start_op = PSAMPLE_CMD_GET_GROUP + 1, .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_obj(*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_INETstatic 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 (test_bit(IP_TUNNEL_KEY_BIT, tun_key->tun_flags) && 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 (test_bit(IP_TUNNEL_DONT_FRAGMENT_BIT, tun_key->tun_flags) && nla_put_flag(skb, PSAMPLE_TUNNEL_KEY_ATTR_DONT_FRAGMENT)) return -EMSGSIZE; if (test_bit(IP_TUNNEL_CSUM_BIT, tun_key->tun_flags) && 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 (test_bit(IP_TUNNEL_OAM_BIT, tun_key->tun_flags) && nla_put_flag(skb, PSAMPLE_TUNNEL_KEY_ATTR_OAM)) return -EMSGSIZE; if (tun_opts_len) { if (test_bit(IP_TUNNEL_GENEVE_OPT_BIT, tun_key->tun_flags) && nla_put(skb, PSAMPLE_TUNNEL_KEY_ATTR_GENEVE_OPTS, tun_opts_len, tun_opts)) return -EMSGSIZE; else if (test_bit(IP_TUNNEL_ERSPAN_OPT_BIT, tun_key->tun_flags) && 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 (test_bit(IP_TUNNEL_KEY_BIT, tun_key->tun_flags)) 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 (test_bit(IP_TUNNEL_DONT_FRAGMENT_BIT, tun_key->tun_flags)) sum += nla_total_size(0); if (test_bit(IP_TUNNEL_CSUM_BIT, tun_key->tun_flags)) 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 (test_bit(IP_TUNNEL_OAM_BIT, tun_key->tun_flags)) sum += nla_total_size(0); if (tun_opts_len) { if (test_bit(IP_TUNNEL_GENEVE_OPT_BIT, tun_key->tun_flags)) sum += nla_total_size(tun_opts_len); else if (test_bit(IP_TUNNEL_ERSPAN_OPT_BIT, tun_key->tun_flags)) sum += nla_total_size(tun_opts_len); }
return sum;}#endif
void psample_sample_packet(struct psample_group *group, const struct sk_buff *skb, u32 sample_rate, const struct psample_metadata *md){ ktime_t tstamp = ktime_get_real(); int out_ifindex = md->out_ifindex; int in_ifindex = md->in_ifindex; u32 trunc_size = md->trunc_size;#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;
if (!genl_has_listeners(&psample_nl_family, group->net, PSAMPLE_NL_MCGRP_SAMPLE)) return;
meta_len = (in_ifindex ? nla_total_size(sizeof(u16)) : 0) + (out_ifindex ? nla_total_size(sizeof(u16)) : 0) + (md->out_tc_valid ? nla_total_size(sizeof(u16)) : 0) + (md->out_tc_occ_valid ? nla_total_size_64bit(sizeof(u64)) : 0) + (md->latency_valid ? nla_total_size_64bit(sizeof(u64)) : 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 */ nla_total_size_64bit(sizeof(u64)) + /* timestamp */ nla_total_size(sizeof(u16)) + /* protocol */ (md->user_cookie_len ? nla_total_size(md->user_cookie_len) : 0) + /* user cookie */ (md->rate_as_probability ? nla_total_size(0) : 0); /* rate as probability */
#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 (md->out_tc_valid) { ret = nla_put_u16(nl_skb, PSAMPLE_ATTR_OUT_TC, md->out_tc); if (unlikely(ret < 0)) goto error; }
if (md->out_tc_occ_valid) { ret = nla_put_u64_64bit(nl_skb, PSAMPLE_ATTR_OUT_TC_OCC, md->out_tc_occ, PSAMPLE_ATTR_PAD); if (unlikely(ret < 0)) goto error; }
if (md->latency_valid) { ret = nla_put_u64_64bit(nl_skb, PSAMPLE_ATTR_LATENCY, md->latency, PSAMPLE_ATTR_PAD); if (unlikely(ret < 0)) goto error; }
ret = nla_put_u64_64bit(nl_skb, PSAMPLE_ATTR_TIMESTAMP, ktime_to_ns(tstamp), PSAMPLE_ATTR_PAD); if (unlikely(ret < 0)) goto error;
ret = nla_put_u16(nl_skb, PSAMPLE_ATTR_PROTO, be16_to_cpu(skb->protocol)); if (unlikely(ret < 0)) goto error;
if (data_len) { int nla_len = nla_attr_size(data_len); struct nlattr *nla;
nla = skb_put(nl_skb, nla_len); nla->nla_type = PSAMPLE_ATTR_DATA; nla->nla_len = nla_len;
if (skb_copy_bits(skb, 0, nla_data(nla), data_len)) goto error;
skb_put_zero(nl_skb, nla_padlen(data_len)); }
#ifdef CONFIG_INET if (tun_info) { ret = psample_ip_tun_to_nlattr(nl_skb, tun_info); if (unlikely(ret < 0)) goto error; }#endif
if (md->user_cookie && md->user_cookie_len && nla_put(nl_skb, PSAMPLE_ATTR_USER_COOKIE, md->user_cookie_len, md->user_cookie)) goto error;
if (md->rate_as_probability && nla_put_flag(nl_skb, PSAMPLE_ATTR_SAMPLE_PROBABILITY)) goto error;
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");