Commit 15824ab2 authored by Stephane Bryant's avatar Stephane Bryant Committed by Pablo Neira Ayuso

netfilter: bridge: pass L2 header and VLAN as netlink attributes in queues to userspace

- This creates 2 netlink attribute NFQA_VLAN and NFQA_L2HDR.
- These are filled up for the PF_BRIDGE family on the way to userspace.
- NFQA_VLAN is a nested attribute, with the NFQA_VLAN_PROTO and the
  NFQA_VLAN_TCI carrying the corresponding vlan_proto and vlan_tci
  fields from the skb using big endian ordering (and using the CFI
  bit as the VLAN_TAG_PRESENT flag in vlan_tci as in the skb)
Signed-off-by: default avatarStephane Bryant <stephane.ml.bryant@gmail.com>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent ac286344
......@@ -30,6 +30,14 @@ struct nfqnl_msg_packet_timestamp {
__aligned_be64 usec;
};
enum nfqnl_vlan_attr {
NFQA_VLAN_UNSPEC,
NFQA_VLAN_PROTO, /* __be16 skb vlan_proto */
NFQA_VLAN_TCI, /* __be16 skb htons(vlan_tci) */
__NFQA_VLAN_MAX,
};
#define NFQA_VLAN_MAX (__NFQA_VLAN_MAX + 1)
enum nfqnl_attr_type {
NFQA_UNSPEC,
NFQA_PACKET_HDR,
......@@ -50,6 +58,8 @@ enum nfqnl_attr_type {
NFQA_UID, /* __u32 sk uid */
NFQA_GID, /* __u32 sk gid */
NFQA_SECCTX, /* security context string */
NFQA_VLAN, /* nested attribute: packet vlan info */
NFQA_L2HDR, /* full L2 header */
__NFQA_MAX
};
......
......@@ -295,6 +295,59 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
return seclen;
}
static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry)
{
struct sk_buff *entskb = entry->skb;
u32 nlalen = 0;
if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb))
return 0;
if (skb_vlan_tag_present(entskb))
nlalen += nla_total_size(nla_total_size(sizeof(__be16)) +
nla_total_size(sizeof(__be16)));
if (entskb->network_header > entskb->mac_header)
nlalen += nla_total_size((entskb->network_header -
entskb->mac_header));
return nlalen;
}
static int nfqnl_put_bridge(struct nf_queue_entry *entry, struct sk_buff *skb)
{
struct sk_buff *entskb = entry->skb;
if (entry->state.pf != PF_BRIDGE || !skb_mac_header_was_set(entskb))
return 0;
if (skb_vlan_tag_present(entskb)) {
struct nlattr *nest;
nest = nla_nest_start(skb, NFQA_VLAN | NLA_F_NESTED);
if (!nest)
goto nla_put_failure;
if (nla_put_be16(skb, NFQA_VLAN_TCI, htons(entskb->vlan_tci)) ||
nla_put_be16(skb, NFQA_VLAN_PROTO, entskb->vlan_proto))
goto nla_put_failure;
nla_nest_end(skb, nest);
}
if (entskb->mac_header < entskb->network_header) {
int len = (int)(entskb->network_header - entskb->mac_header);
if (nla_put(skb, NFQA_L2HDR, len, skb_mac_header(entskb)))
goto nla_put_failure;
}
return 0;
nla_put_failure:
return -1;
}
static struct sk_buff *
nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
struct nf_queue_entry *entry,
......@@ -334,6 +387,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
if (entskb->tstamp.tv64)
size += nla_total_size(sizeof(struct nfqnl_msg_packet_timestamp));
size += nfqnl_get_bridge_size(entry);
if (entry->state.hook <= NF_INET_FORWARD ||
(entry->state.hook == NF_INET_POST_ROUTING && entskb->sk == NULL))
csum_verify = !skb_csum_unnecessary(entskb);
......@@ -497,6 +552,9 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue,
}
}
if (nfqnl_put_bridge(entry, skb) < 0)
goto nla_put_failure;
if (entskb->tstamp.tv64) {
struct nfqnl_msg_packet_timestamp ts;
struct timespec64 kts = ktime_to_timespec64(skb->tstamp);
......
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