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Diffstat (limited to 'net/netlink/af_netlink.c')
-rw-r--r--net/netlink/af_netlink.c150
1 files changed, 125 insertions, 25 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 894cda0206bb..15c731f03fa6 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1206,7 +1206,8 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
struct module *module = NULL;
struct mutex *cb_mutex;
struct netlink_sock *nlk;
- void (*bind)(int group);
+ int (*bind)(int group);
+ void (*unbind)(int group);
int err = 0;
sock->state = SS_UNCONNECTED;
@@ -1232,6 +1233,7 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
err = -EPROTONOSUPPORT;
cb_mutex = nl_table[protocol].cb_mutex;
bind = nl_table[protocol].bind;
+ unbind = nl_table[protocol].unbind;
netlink_unlock_table();
if (err < 0)
@@ -1248,6 +1250,7 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol,
nlk = nlk_sk(sock->sk);
nlk->module = module;
nlk->netlink_bind = bind;
+ nlk->netlink_unbind = unbind;
out:
return err;
@@ -1301,6 +1304,7 @@ static int netlink_release(struct socket *sock)
kfree_rcu(old, rcu);
nl_table[sk->sk_protocol].module = NULL;
nl_table[sk->sk_protocol].bind = NULL;
+ nl_table[sk->sk_protocol].unbind = NULL;
nl_table[sk->sk_protocol].flags = 0;
nl_table[sk->sk_protocol].registered = 0;
}
@@ -1360,7 +1364,74 @@ retry:
return err;
}
-static inline int netlink_capable(const struct socket *sock, unsigned int flag)
+/**
+ * __netlink_ns_capable - General netlink message capability test
+ * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace.
+ * @user_ns: The user namespace of the capability to use
+ * @cap: The capability to use
+ *
+ * Test to see if the opener of the socket we received the message
+ * from had when the netlink socket was created and the sender of the
+ * message has has the capability @cap in the user namespace @user_ns.
+ */
+bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
+ struct user_namespace *user_ns, int cap)
+{
+ return ((nsp->flags & NETLINK_SKB_DST) ||
+ file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) &&
+ ns_capable(user_ns, cap);
+}
+EXPORT_SYMBOL(__netlink_ns_capable);
+
+/**
+ * netlink_ns_capable - General netlink message capability test
+ * @skb: socket buffer holding a netlink command from userspace
+ * @user_ns: The user namespace of the capability to use
+ * @cap: The capability to use
+ *
+ * Test to see if the opener of the socket we received the message
+ * from had when the netlink socket was created and the sender of the
+ * message has has the capability @cap in the user namespace @user_ns.
+ */
+bool netlink_ns_capable(const struct sk_buff *skb,
+ struct user_namespace *user_ns, int cap)
+{
+ return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap);
+}
+EXPORT_SYMBOL(netlink_ns_capable);
+
+/**
+ * netlink_capable - Netlink global message capability test
+ * @skb: socket buffer holding a netlink command from userspace
+ * @cap: The capability to use
+ *
+ * Test to see if the opener of the socket we received the message
+ * from had when the netlink socket was created and the sender of the
+ * message has has the capability @cap in all user namespaces.
+ */
+bool netlink_capable(const struct sk_buff *skb, int cap)
+{
+ return netlink_ns_capable(skb, &init_user_ns, cap);
+}
+EXPORT_SYMBOL(netlink_capable);
+
+/**
+ * netlink_net_capable - Netlink network namespace message capability test
+ * @skb: socket buffer holding a netlink command from userspace
+ * @cap: The capability to use
+ *
+ * Test to see if the opener of the socket we received the message
+ * from had when the netlink socket was created and the sender of the
+ * message has has the capability @cap over the network namespace of
+ * the socket we received the message from.
+ */
+bool netlink_net_capable(const struct sk_buff *skb, int cap)
+{
+ return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap);
+}
+EXPORT_SYMBOL(netlink_net_capable);
+
+static inline int netlink_allowed(const struct socket *sock, unsigned int flag)
{
return (nl_table[sock->sk->sk_protocol].flags & flag) ||
ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN);
@@ -1411,6 +1482,19 @@ static int netlink_realloc_groups(struct sock *sk)
return err;
}
+static void netlink_unbind(int group, long unsigned int groups,
+ struct netlink_sock *nlk)
+{
+ int undo;
+
+ if (!nlk->netlink_unbind)
+ return;
+
+ for (undo = 0; undo < group; undo++)
+ if (test_bit(group, &groups))
+ nlk->netlink_unbind(undo);
+}
+
static int netlink_bind(struct socket *sock, struct sockaddr *addr,
int addr_len)
{
@@ -1419,6 +1503,7 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr,
struct netlink_sock *nlk = nlk_sk(sk);
struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
int err;
+ long unsigned int groups = nladdr->nl_groups;
if (addr_len < sizeof(struct sockaddr_nl))
return -EINVAL;
@@ -1427,45 +1512,53 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr,
return -EINVAL;
/* Only superuser is allowed to listen multicasts */
- if (nladdr->nl_groups) {
- if (!netlink_capable(sock, NL_CFG_F_NONROOT_RECV))
+ if (groups) {
+ if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
return -EPERM;
err = netlink_realloc_groups(sk);
if (err)
return err;
}
- if (nlk->portid) {
+ if (nlk->portid)
if (nladdr->nl_pid != nlk->portid)
return -EINVAL;
- } else {
+
+ if (nlk->netlink_bind && groups) {
+ int group;
+
+ for (group = 0; group < nlk->ngroups; group++) {
+ if (!test_bit(group, &groups))
+ continue;
+ err = nlk->netlink_bind(group);
+ if (!err)
+ continue;
+ netlink_unbind(group, groups, nlk);
+ return err;
+ }
+ }
+
+ if (!nlk->portid) {
err = nladdr->nl_pid ?
netlink_insert(sk, net, nladdr->nl_pid) :
netlink_autobind(sock);
- if (err)
+ if (err) {
+ netlink_unbind(nlk->ngroups - 1, groups, nlk);
return err;
+ }
}
- if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
+ if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
return 0;
netlink_table_grab();
netlink_update_subscriptions(sk, nlk->subscriptions +
- hweight32(nladdr->nl_groups) -
+ hweight32(groups) -
hweight32(nlk->groups[0]));
- nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups;
+ nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups;
netlink_update_listeners(sk);
netlink_table_ungrab();
- if (nlk->netlink_bind && nlk->groups[0]) {
- int i;
-
- for (i = 0; i < nlk->ngroups; i++) {
- if (test_bit(i, nlk->groups))
- nlk->netlink_bind(i);
- }
- }
-
return 0;
}
@@ -1490,7 +1583,7 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
return -EINVAL;
if ((nladdr->nl_groups || nladdr->nl_pid) &&
- !netlink_capable(sock, NL_CFG_F_NONROOT_SEND))
+ !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
return -EPERM;
if (!nlk->portid)
@@ -2096,20 +2189,24 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname,
break;
case NETLINK_ADD_MEMBERSHIP:
case NETLINK_DROP_MEMBERSHIP: {
- if (!netlink_capable(sock, NL_CFG_F_NONROOT_RECV))
+ if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
return -EPERM;
err = netlink_realloc_groups(sk);
if (err)
return err;
if (!val || val - 1 >= nlk->ngroups)
return -EINVAL;
+ if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) {
+ err = nlk->netlink_bind(val);
+ if (err)
+ return err;
+ }
netlink_table_grab();
netlink_update_socket_mc(nlk, val,
optname == NETLINK_ADD_MEMBERSHIP);
netlink_table_ungrab();
-
- if (nlk->netlink_bind)
- nlk->netlink_bind(val);
+ if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind)
+ nlk->netlink_unbind(val);
err = 0;
break;
@@ -2228,6 +2325,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
struct sk_buff *skb;
int err;
struct scm_cookie scm;
+ u32 netlink_skb_flags = 0;
if (msg->msg_flags&MSG_OOB)
return -EOPNOTSUPP;
@@ -2247,8 +2345,9 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
dst_group = ffs(addr->nl_groups);
err = -EPERM;
if ((dst_group || dst_portid) &&
- !netlink_capable(sock, NL_CFG_F_NONROOT_SEND))
+ !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
goto out;
+ netlink_skb_flags |= NETLINK_SKB_DST;
} else {
dst_portid = nlk->dst_portid;
dst_group = nlk->dst_group;
@@ -2278,6 +2377,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
NETLINK_CB(skb).portid = nlk->portid;
NETLINK_CB(skb).dst_group = dst_group;
NETLINK_CB(skb).creds = siocb->scm->creds;
+ NETLINK_CB(skb).flags = netlink_skb_flags;
err = -EFAULT;
if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
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