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Message-Id: <1368800738-4364-1-git-send-email-nicolas.dichtel@6wind.com>
Date: Fri, 17 May 2013 16:25:38 +0200
From: Nicolas Dichtel <nicolas.dichtel@...nd.com>
To: davem@...emloft.net
Cc: xiyou.wangcong@...il.com, eric.dumazet@...il.com,
netdev@...r.kernel.org, Nicolas Dichtel <nicolas.dichtel@...nd.com>
Subject: [PATCH net-next v3] sock_diag: notify packet socket creation/deletion
With this patch, a netlink message is sent each time a packet socket is created
or deleted.
The framework is generic, so it's easy to add the notification for other kind of
sockets.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@...nd.com>
---
This patch was sent the first time in a serie of 5 patches, but was not
included with the last version of this serie. Hence, I resend it as v3,
after a rebase on net-next.
I'm not sure if this patch was acceptable or not (from a security point of
view). Note that BPF filters and uid are not put in the messsage, because
user_ns is unknown.
v3: rebase it on net-next
export the symbol __sock_diag_notify (af_packet can be compiled as a
module)
v2: add sock_diag_notify_del() to avoid confusion of the meaning of the second
arg of __sock_diag_notify()
include/linux/sock_diag.h | 4 ++++
include/uapi/linux/sock_diag.h | 13 ++++++++++++-
net/core/sock_diag.c | 42 ++++++++++++++++++++++++++++++++++++++++++
net/packet/af_packet.c | 4 ++++
net/packet/diag.c | 30 +++++++++++++++++++++++++-----
5 files changed, 87 insertions(+), 6 deletions(-)
diff --git a/include/linux/sock_diag.h b/include/linux/sock_diag.h
index 54f91d3..86cd4f4 100644
--- a/include/linux/sock_diag.h
+++ b/include/linux/sock_diag.h
@@ -11,6 +11,7 @@ struct sock;
struct sock_diag_handler {
__u8 family;
int (*dump)(struct sk_buff *skb, struct nlmsghdr *nlh);
+ int (*notify)(struct sk_buff *skb, struct sock *sk, bool create);
};
int sock_diag_register(const struct sock_diag_handler *h);
@@ -25,5 +26,8 @@ void sock_diag_save_cookie(void *sk, __u32 *cookie);
int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attr);
int sock_diag_put_filterinfo(struct user_namespace *user_ns, struct sock *sk,
struct sk_buff *skb, int attrtype);
+int __sock_diag_notify(struct sock *sk, bool create);
+#define sock_diag_notify(sk) __sock_diag_notify(sk, true)
+#define sock_diag_notify_del(sk) __sock_diag_notify(sk, false)
#endif
diff --git a/include/uapi/linux/sock_diag.h b/include/uapi/linux/sock_diag.h
index b00e29e..9e9ffa0 100644
--- a/include/uapi/linux/sock_diag.h
+++ b/include/uapi/linux/sock_diag.h
@@ -3,7 +3,18 @@
#include <linux/types.h>
-#define SOCK_DIAG_BY_FAMILY 20
+#define SOCK_DIAG_BY_FAMILY 20
+#define SOCK_DIAG_BY_FAMILY_DEL 21
+
+/* SOCK_DIAG multicast groups */
+enum nldiag_groups {
+ NLDIAGGRP_NONE,
+#define NLDIAGGRP_NONE NLDIAGGRP_NONE
+ NLDIAGGRP_NOTIFY,
+#define NLDIAGGRP_NOTIFY NLDIAGGRP_NOTIFY
+ __NLDIAGGRP_MAX
+};
+#define NLDIAGGRP_MAX (__NLDIAGGRP_MAX - 1)
struct sock_diag_req {
__u8 sdiag_family;
diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c
index d5bef0b0..7cc81a8 100644
--- a/net/core/sock_diag.c
+++ b/net/core/sock_diag.c
@@ -192,6 +192,48 @@ static void sock_diag_rcv(struct sk_buff *skb)
mutex_unlock(&sock_diag_mutex);
}
+int __sock_diag_notify(struct sock *sk, bool create)
+{
+ const struct sock_diag_handler *hndl;
+ int err;
+
+ if (sock_diag_handlers[sk->sk_family] == NULL)
+ request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
+ NETLINK_SOCK_DIAG, sk->sk_family);
+
+ mutex_lock(&sock_diag_table_mutex);
+ hndl = sock_diag_handlers[sk->sk_family];
+ if (hndl == NULL)
+ err = -ENOENT;
+ else if (hndl->notify == NULL)
+ err = -ENOSYS;
+ else {
+ struct net *net = sock_net(sk);
+ struct sock *nlsk = net->diag_nlsk;
+ struct sk_buff *skb;
+
+ skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+ if (skb == NULL) {
+ err = -ENOBUFS;
+ goto out;
+ }
+
+ err = hndl->notify(skb, sk, create);
+ if (err) {
+ nlmsg_free(skb);
+ goto out;
+ }
+
+ err = nlmsg_notify(nlsk, skb, 0, NLDIAGGRP_NOTIFY, 0,
+ GFP_KERNEL);
+ }
+out:
+ mutex_unlock(&sock_diag_table_mutex);
+
+ return err;
+}
+EXPORT_SYMBOL(__sock_diag_notify);
+
static int __net_init diag_net_init(struct net *net)
{
struct netlink_kernel_cfg cfg = {
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 8ec1bca..4940a85 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -88,6 +88,7 @@
#include <linux/virtio_net.h>
#include <linux/errqueue.h>
#include <linux/net_tstamp.h>
+#include <linux/sock_diag.h>
#ifdef CONFIG_INET
#include <net/inet_common.h>
@@ -2415,6 +2416,8 @@ static int packet_release(struct socket *sock)
if (!sk)
return 0;
+ sock_diag_notify_del(sk);
+
net = sock_net(sk);
po = pkt_sk(sk);
@@ -2633,6 +2636,7 @@ static int packet_create(struct net *net, struct socket *sock, int protocol,
sock_prot_inuse_add(net, &packet_proto, 1);
preempt_enable();
+ sock_diag_notify(sk);
return 0;
out:
return err;
diff --git a/net/packet/diag.c b/net/packet/diag.c
index a9584a2..74671db 100644
--- a/net/packet/diag.c
+++ b/net/packet/diag.c
@@ -128,13 +128,13 @@ static int pdiag_put_fanout(struct packet_sock *po, struct sk_buff *nlskb)
static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
struct packet_diag_req *req,
struct user_namespace *user_ns,
- u32 portid, u32 seq, u32 flags, int sk_ino)
+ u32 portid, u32 seq, u32 flags, int sk_ino, int cmd)
{
struct nlmsghdr *nlh;
struct packet_diag_msg *rp;
struct packet_sock *po = pkt_sk(sk);
- nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rp), flags);
+ nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rp), flags);
if (!nlh)
return -EMSGSIZE;
@@ -149,7 +149,7 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
pdiag_put_info(po, skb))
goto out_nlmsg_trim;
- if ((req->pdiag_show & PACKET_SHOW_INFO) &&
+ if ((req->pdiag_show & PACKET_SHOW_INFO) && user_ns &&
nla_put_u32(skb, PACKET_DIAG_UID,
from_kuid_munged(user_ns, sock_i_uid(sk))))
goto out_nlmsg_trim;
@@ -170,7 +170,7 @@ static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
sock_diag_put_meminfo(sk, skb, PACKET_DIAG_MEMINFO))
goto out_nlmsg_trim;
- if ((req->pdiag_show & PACKET_SHOW_FILTER) &&
+ if ((req->pdiag_show & PACKET_SHOW_FILTER) && user_ns &&
sock_diag_put_filterinfo(user_ns, sk, skb, PACKET_DIAG_FILTER))
goto out_nlmsg_trim;
@@ -202,7 +202,7 @@ static int packet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
sk_user_ns(NETLINK_CB(cb->skb).sk),
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
- sock_i_ino(sk)) < 0)
+ sock_i_ino(sk), SOCK_DIAG_BY_FAMILY) < 0)
goto done;
next:
num++;
@@ -237,9 +237,29 @@ static int packet_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
return -EOPNOTSUPP;
}
+static int packet_diag_handler_notify(struct sk_buff *skb, struct sock *sk,
+ bool create)
+{
+ struct packet_diag_req req;
+ int err, cmd;
+
+ memset(&req, 0, sizeof(struct packet_diag_req));
+ if (create) {
+ req.pdiag_show |= PACKET_SHOW_INFO | PACKET_SHOW_MCLIST;
+ req.pdiag_show |= PACKET_SHOW_RING_CFG | PACKET_SHOW_FANOUT;
+ req.pdiag_show |= PACKET_SHOW_MEMINFO | PACKET_SHOW_FILTER;
+ cmd = SOCK_DIAG_BY_FAMILY;
+ } else
+ cmd = SOCK_DIAG_BY_FAMILY_DEL;
+
+ err = sk_diag_fill(sk, skb, &req, NULL, 0, 0, 0, sock_i_ino(sk), cmd);
+ return err > 0 ? 0 : err;
+}
+
static const struct sock_diag_handler packet_diag_handler = {
.family = AF_PACKET,
.dump = packet_diag_handler_dump,
+ .notify = packet_diag_handler_notify,
};
static int __init packet_diag_init(void)
--
1.8.2.1
--
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