From 08c0cad69f32ad1e881fa3fb7f5e0a25db5b07ce Mon Sep 17 00:00:00 2001 From: Valentina Giusti Date: Fri, 20 Dec 2013 17:28:53 +0100 Subject: [PATCH] netfilter: nfnetlink_queue: enable UID/GID socket info retrieval Thanks to commits 41063e9 (ipv4: Early TCP socket demux) and 421b388 (udp: ipv4: Add udp early demux) it is now possible to parse UID and GID socket info also for incoming TCP and UDP connections. Having this info available, it is convenient to let NFQUEUE parse it in order to improve and refine the traffic analysis in userspace. Signed-off-by: Valentina Giusti Signed-off-by: Pablo Neira Ayuso --- .../uapi/linux/netfilter/nfnetlink_queue.h | 5 ++- net/netfilter/nfnetlink_queue_core.c | 34 +++++++++++++++++++ 2 files changed, 38 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/netfilter/nfnetlink_queue.h b/include/uapi/linux/netfilter/nfnetlink_queue.h index 0132bad79de..8dd819e2b5f 100644 --- a/include/uapi/linux/netfilter/nfnetlink_queue.h +++ b/include/uapi/linux/netfilter/nfnetlink_queue.h @@ -47,6 +47,8 @@ enum nfqnl_attr_type { NFQA_CAP_LEN, /* __u32 length of captured packet */ NFQA_SKB_INFO, /* __u32 skb meta information */ NFQA_EXP, /* nf_conntrack_netlink.h */ + NFQA_UID, /* __u32 sk uid */ + NFQA_GID, /* __u32 sk gid */ __NFQA_MAX }; @@ -99,7 +101,8 @@ enum nfqnl_attr_config { #define NFQA_CFG_F_FAIL_OPEN (1 << 0) #define NFQA_CFG_F_CONNTRACK (1 << 1) #define NFQA_CFG_F_GSO (1 << 2) -#define NFQA_CFG_F_MAX (1 << 3) +#define NFQA_CFG_F_UID_GID (1 << 3) +#define NFQA_CFG_F_MAX (1 << 4) /* flags for NFQA_SKB_INFO */ /* packet appears to have wrong checksums, but they are ok */ diff --git a/net/netfilter/nfnetlink_queue_core.c b/net/netfilter/nfnetlink_queue_core.c index 21258cf7009..d3cf12b8317 100644 --- a/net/netfilter/nfnetlink_queue_core.c +++ b/net/netfilter/nfnetlink_queue_core.c @@ -297,6 +297,31 @@ nfqnl_put_packet_info(struct sk_buff *nlskb, struct sk_buff *packet, return flags ? nla_put_be32(nlskb, NFQA_SKB_INFO, htonl(flags)) : 0; } +static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk) +{ + const struct cred *cred; + + if (sk->sk_state == TCP_TIME_WAIT) + return 0; + + read_lock_bh(&sk->sk_callback_lock); + if (sk->sk_socket && sk->sk_socket->file) { + cred = sk->sk_socket->file->f_cred; + if (nla_put_be32(skb, NFQA_UID, + htonl(from_kuid_munged(&init_user_ns, cred->fsuid)))) + goto nla_put_failure; + if (nla_put_be32(skb, NFQA_GID, + htonl(from_kgid_munged(&init_user_ns, cred->fsgid)))) + goto nla_put_failure; + } + read_unlock_bh(&sk->sk_callback_lock); + return 0; + +nla_put_failure: + read_unlock_bh(&sk->sk_callback_lock); + return -1; +} + static struct sk_buff * nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, struct nf_queue_entry *entry, @@ -372,6 +397,11 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, if (queue->flags & NFQA_CFG_F_CONNTRACK) ct = nfqnl_ct_get(entskb, &size, &ctinfo); + if (queue->flags & NFQA_CFG_F_UID_GID) { + size += (nla_total_size(sizeof(u_int32_t)) /* uid */ + + nla_total_size(sizeof(u_int32_t))); /* gid */ + } + skb = nfnetlink_alloc_skb(net, size, queue->peer_portid, GFP_ATOMIC); if (!skb) @@ -484,6 +514,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, goto nla_put_failure; } + if ((queue->flags & NFQA_CFG_F_UID_GID) && entskb->sk && + nfqnl_put_sk_uidgid(skb, entskb->sk) < 0) + goto nla_put_failure; + if (ct && nfqnl_ct_put(skb, ct, ctinfo) < 0) goto nla_put_failure; -- 2.46.0