From a52e95abf772b43c9226e9a72d3c1353903ba96f Mon Sep 17 00:00:00 2001
From: Lorenzo Colitti <lorenzo@google.com>
Date: Wed, 24 Aug 2016 15:46:26 +0900
Subject: [PATCH] net: diag: allow socket bytecode filters to match socket
marks
This allows a privileged process to filter by socket mark when
dumping sockets via INET_DIAG_BY_FAMILY. This is useful on
systems that use mark-based routing such as Android.
The ability to filter socket marks requires CAP_NET_ADMIN, which
is consistent with other privileged operations allowed by the
SOCK_DIAG interface such as the ability to destroy sockets and
the ability to inspect BPF filters attached to packet sockets.
Tested: https://android-review.googlesource.com/261350
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/uapi/linux/inet_diag.h | 6 ++++++
net/ipv4/inet_diag.c | 36 +++++++++++++++++++++++++++++++---
2 files changed, 39 insertions(+), 3 deletions(-)
diff --git a/include/uapi/linux/inet_diag.h b/include/uapi/linux/inet_diag.h
index abbd1dc5d6834..5581206a08ae2 100644
--- a/include/uapi/linux/inet_diag.h
+++ b/include/uapi/linux/inet_diag.h
@@ -73,6 +73,7 @@ enum {
INET_DIAG_BC_S_COND,
INET_DIAG_BC_D_COND,
INET_DIAG_BC_DEV_COND, /* u32 ifindex */
+ INET_DIAG_BC_MARK_COND,
};
struct inet_diag_hostcond {
@@ -82,6 +83,11 @@ struct inet_diag_hostcond {
__be32 addr[0];
};
+struct inet_diag_markcond {
+ __u32 mark;
+ __u32 mask;
+};
+
/* Base info structure. It contains socket identity (addrs/ports/cookie)
* and, alas, the information shown by netstat. */
struct inet_diag_msg {
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index a89b68c6a9348..abfbe492ebfe3 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -45,6 +45,7 @@ struct inet_diag_entry {
u16 family;
u16 userlocks;
u32 ifindex;
+ u32 mark;
};
static DEFINE_MUTEX(inet_diag_table_mutex);
@@ -580,6 +581,14 @@ static int inet_diag_bc_run(const struct nlattr *_bc,
yes = 0;
break;
}
+ case INET_DIAG_BC_MARK_COND: {
+ struct inet_diag_markcond *cond;
+
+ cond = (struct inet_diag_markcond *)(op + 1);
+ if ((entry->mark & cond->mask) != cond->mark)
+ yes = 0;
+ break;
+ }
}
if (yes) {
@@ -624,6 +633,12 @@ int inet_diag_bc_sk(const struct nlattr *bc, struct sock *sk)
entry.dport = ntohs(inet->inet_dport);
entry.ifindex = sk->sk_bound_dev_if;
entry.userlocks = sk_fullsock(sk) ? sk->sk_userlocks : 0;
+ if (sk_fullsock(sk))
+ entry.mark = sk->sk_mark;
+ else if (sk->sk_state == TCP_NEW_SYN_RECV)
+ entry.mark = inet_rsk(inet_reqsk(sk))->ir_mark;
+ else
+ entry.mark = 0;
return inet_diag_bc_run(bc, &entry);
}
@@ -706,8 +721,17 @@ static bool valid_port_comparison(const struct inet_diag_bc_op *op,
return true;
}
-static int inet_diag_bc_audit(const struct nlattr *attr)
+static bool valid_markcond(const struct inet_diag_bc_op *op, int len,
+ int *min_len)
{
+ *min_len += sizeof(struct inet_diag_markcond);
+ return len >= *min_len;
+}
+
+static int inet_diag_bc_audit(const struct nlattr *attr,
+ const struct sk_buff *skb)
+{
+ bool net_admin = netlink_net_capable(skb, CAP_NET_ADMIN);
const void *bytecode, *bc;
int bytecode_len, len;
@@ -738,6 +762,12 @@ static int inet_diag_bc_audit(const struct nlattr *attr)
if (!valid_port_comparison(bc, len, &min_len))
return -EINVAL;
break;
+ case INET_DIAG_BC_MARK_COND:
+ if (!net_admin)
+ return -EPERM;
+ if (!valid_markcond(bc, len, &min_len))
+ return -EINVAL;
+ break;
case INET_DIAG_BC_AUTO:
case INET_DIAG_BC_JMP:
case INET_DIAG_BC_NOP:
@@ -1030,7 +1060,7 @@ static int inet_diag_rcv_msg_compat(struct sk_buff *skb, struct nlmsghdr *nlh)
attr = nlmsg_find_attr(nlh, hdrlen,
INET_DIAG_REQ_BYTECODE);
- err = inet_diag_bc_audit(attr);
+ err = inet_diag_bc_audit(attr, skb);
if (err)
return err;
}
@@ -1061,7 +1091,7 @@ static int inet_diag_handler_cmd(struct sk_buff *skb, struct nlmsghdr *h)
attr = nlmsg_find_attr(h, hdrlen,
INET_DIAG_REQ_BYTECODE);
- err = inet_diag_bc_audit(attr);
+ err = inet_diag_bc_audit(attr, skb);
if (err)
return err;
}
--
2.30.2