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-rw-r--r--net/netlink/af_netlink.c230
-rw-r--r--net/netlink/af_netlink.h7
-rw-r--r--net/netlink/genetlink.c29
3 files changed, 202 insertions, 64 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index bca50b95c18..e6fac7e3db5 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -131,7 +131,7 @@ int netlink_add_tap(struct netlink_tap *nt)
}
EXPORT_SYMBOL_GPL(netlink_add_tap);
-int __netlink_remove_tap(struct netlink_tap *nt)
+static int __netlink_remove_tap(struct netlink_tap *nt)
{
bool found = false;
struct netlink_tap *tmp;
@@ -155,7 +155,6 @@ out:
return found ? 0 : -ENODEV;
}
-EXPORT_SYMBOL_GPL(__netlink_remove_tap);
int netlink_remove_tap(struct netlink_tap *nt)
{
@@ -204,6 +203,8 @@ static int __netlink_deliver_tap_skb(struct sk_buff *skb,
if (nskb) {
nskb->dev = dev;
nskb->protocol = htons((u16) sk->sk_protocol);
+ nskb->pkt_type = netlink_is_kernel(sk) ?
+ PACKET_KERNEL : PACKET_USER;
ret = dev_queue_xmit(nskb);
if (unlikely(ret > 0))
@@ -239,6 +240,13 @@ static void netlink_deliver_tap(struct sk_buff *skb)
rcu_read_unlock();
}
+static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src,
+ struct sk_buff *skb)
+{
+ if (!(netlink_is_kernel(dst) && netlink_is_kernel(src)))
+ netlink_deliver_tap(skb);
+}
+
static void netlink_overrun(struct sock *sk)
{
struct netlink_sock *nlk = nlk_sk(sk);
@@ -628,7 +636,7 @@ static unsigned int netlink_poll(struct file *file, struct socket *sock,
while (nlk->cb_running && netlink_dump_space(nlk)) {
err = netlink_dump(sk);
if (err < 0) {
- sk->sk_err = err;
+ sk->sk_err = -err;
sk->sk_error_report(sk);
break;
}
@@ -1198,7 +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;
@@ -1224,6 +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)
@@ -1240,6 +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;
@@ -1293,6 +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;
}
@@ -1352,7 +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);
@@ -1403,6 +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)
{
@@ -1411,6 +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;
@@ -1419,45 +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;
}
@@ -1481,8 +1582,8 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
if (addr->sa_family != AF_NETLINK)
return -EINVAL;
- /* Only superuser is allowed to send multicasts */
- if (nladdr->nl_groups && !netlink_capable(sock, NL_CFG_F_NONROOT_SEND))
+ if ((nladdr->nl_groups || nladdr->nl_pid) &&
+ !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
return -EPERM;
if (!nlk->portid)
@@ -1645,7 +1746,7 @@ static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb)
else
#endif /* CONFIG_NETLINK_MMAP */
skb_queue_tail(&sk->sk_receive_queue, skb);
- sk->sk_data_ready(sk, len);
+ sk->sk_data_ready(sk);
return len;
}
@@ -1697,14 +1798,10 @@ static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb,
ret = -ECONNREFUSED;
if (nlk->netlink_rcv != NULL) {
- /* We could do a netlink_deliver_tap(skb) here as well
- * but since this is intended for the kernel only, we
- * should rather let it stay under the hood.
- */
-
ret = skb->len;
netlink_skb_set_owner_r(skb, sk);
NETLINK_CB(skb).sk = ssk;
+ netlink_deliver_tap_kernel(sk, ssk, skb);
nlk->netlink_rcv(skb);
consume_skb(skb);
} else {
@@ -1769,6 +1866,9 @@ struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size,
if (ring->pg_vec == NULL)
goto out_put;
+ if (ring->frame_size - NL_MMAP_HDRLEN < size)
+ goto out_put;
+
skb = alloc_skb_head(gfp_mask);
if (skb == NULL)
goto err1;
@@ -1778,6 +1878,7 @@ struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size,
if (ring->pg_vec == NULL)
goto out_free;
+ /* check again under lock */
maxlen = ring->frame_size - NL_MMAP_HDRLEN;
if (maxlen < size)
goto out_free;
@@ -2088,20 +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;
@@ -2214,12 +2319,13 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
struct sock *sk = sock->sk;
struct netlink_sock *nlk = nlk_sk(sk);
- struct sockaddr_nl *addr = msg->msg_name;
+ DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
u32 dst_portid;
u32 dst_group;
struct sk_buff *skb;
int err;
struct scm_cookie scm;
+ u32 netlink_skb_flags = 0;
if (msg->msg_flags&MSG_OOB)
return -EOPNOTSUPP;
@@ -2239,8 +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;
@@ -2270,6 +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)) {
@@ -2335,6 +2443,11 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
}
#endif
+ /* Record the max length of recvmsg() calls for future allocations */
+ nlk->max_recvmsg_len = max(nlk->max_recvmsg_len, len);
+ nlk->max_recvmsg_len = min_t(size_t, nlk->max_recvmsg_len,
+ 16384);
+
copied = data_skb->len;
if (len < copied) {
msg->msg_flags |= MSG_TRUNC;
@@ -2345,7 +2458,7 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied);
if (msg->msg_name) {
- struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name;
+ DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
addr->nl_family = AF_NETLINK;
addr->nl_pad = 0;
addr->nl_pid = NETLINK_CB(skb).portid;
@@ -2370,7 +2483,7 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
ret = netlink_dump(sk);
if (ret) {
- sk->sk_err = ret;
+ sk->sk_err = -ret;
sk->sk_error_report(sk);
}
}
@@ -2381,7 +2494,7 @@ out:
return err ? : copied;
}
-static void netlink_data_ready(struct sock *sk, int len)
+static void netlink_data_ready(struct sock *sk)
{
BUG();
}
@@ -2535,28 +2648,13 @@ void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
netlink_update_socket_mc(nlk_sk(sk), group, 0);
}
-/**
- * netlink_clear_multicast_users - kick off multicast listeners
- *
- * This function removes all listeners from the given group.
- * @ksk: The kernel netlink socket, as returned by
- * netlink_kernel_create().
- * @group: The multicast group to clear.
- */
-void netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
-{
- netlink_table_grab();
- __netlink_clear_multicast_users(ksk, group);
- netlink_table_ungrab();
-}
-
struct nlmsghdr *
__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags)
{
struct nlmsghdr *nlh;
int size = nlmsg_msg_size(len);
- nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size));
+ nlh = (struct nlmsghdr *)skb_put(skb, NLMSG_ALIGN(size));
nlh->nlmsg_type = type;
nlh->nlmsg_len = size;
nlh->nlmsg_flags = flags;
@@ -2594,7 +2692,27 @@ static int netlink_dump(struct sock *sk)
if (!netlink_rx_is_mmaped(sk) &&
atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
goto errout_skb;
- skb = netlink_alloc_skb(sk, alloc_size, nlk->portid, GFP_KERNEL);
+
+ /* NLMSG_GOODSIZE is small to avoid high order allocations being
+ * required, but it makes sense to _attempt_ a 16K bytes allocation
+ * to reduce number of system calls on dump operations, if user
+ * ever provided a big enough buffer.
+ */
+ if (alloc_size < nlk->max_recvmsg_len) {
+ skb = netlink_alloc_skb(sk,
+ nlk->max_recvmsg_len,
+ nlk->portid,
+ GFP_KERNEL |
+ __GFP_NOWARN |
+ __GFP_NORETRY);
+ /* available room should be exact amount to avoid MSG_TRUNC */
+ if (skb)
+ skb_reserve(skb, skb_tailroom(skb) -
+ nlk->max_recvmsg_len);
+ }
+ if (!skb)
+ skb = netlink_alloc_skb(sk, alloc_size, nlk->portid,
+ GFP_KERNEL);
if (!skb)
goto errout_skb;
netlink_skb_set_owner_r(skb, sk);
diff --git a/net/netlink/af_netlink.h b/net/netlink/af_netlink.h
index acbd774eeb7..0b59d441f5b 100644
--- a/net/netlink/af_netlink.h
+++ b/net/netlink/af_netlink.h
@@ -31,13 +31,15 @@ struct netlink_sock {
u32 ngroups;
unsigned long *groups;
unsigned long state;
+ size_t max_recvmsg_len;
wait_queue_head_t wait;
bool cb_running;
struct netlink_callback cb;
struct mutex *cb_mutex;
struct mutex cb_def_mutex;
void (*netlink_rcv)(struct sk_buff *skb);
- void (*netlink_bind)(int group);
+ int (*netlink_bind)(int group);
+ void (*netlink_unbind)(int group);
struct module *module;
#ifdef CONFIG_NETLINK_MMAP
struct mutex pg_vec_lock;
@@ -73,7 +75,8 @@ struct netlink_table {
unsigned int groups;
struct mutex *cb_mutex;
struct module *module;
- void (*bind)(int group);
+ int (*bind)(int group);
+ void (*unbind)(int group);
bool (*compare)(struct net *net, struct sock *sock);
int registered;
};
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 713671ae45a..76393f2f4b2 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -317,7 +317,7 @@ static void genl_unregister_mc_groups(struct genl_family *family)
}
}
-static int genl_validate_ops(struct genl_family *family)
+static int genl_validate_ops(const struct genl_family *family)
{
const struct genl_ops *ops = family->ops;
unsigned int n_ops = family->n_ops;
@@ -337,10 +337,6 @@ static int genl_validate_ops(struct genl_family *family)
return -EINVAL;
}
- /* family is not registered yet, so no locking needed */
- family->ops = ops;
- family->n_ops = n_ops;
-
return 0;
}
@@ -461,6 +457,26 @@ int genl_unregister_family(struct genl_family *family)
EXPORT_SYMBOL(genl_unregister_family);
/**
+ * genlmsg_new_unicast - Allocate generic netlink message for unicast
+ * @payload: size of the message payload
+ * @info: information on destination
+ * @flags: the type of memory to allocate
+ *
+ * Allocates a new sk_buff large enough to cover the specified payload
+ * plus required Netlink headers. Will check receiving socket for
+ * memory mapped i/o capability and use it if enabled. Will fall back
+ * to non-mapped skb if message size exceeds the frame size of the ring.
+ */
+struct sk_buff *genlmsg_new_unicast(size_t payload, struct genl_info *info,
+ gfp_t flags)
+{
+ size_t len = nlmsg_total_size(genlmsg_total_size(payload));
+
+ return netlink_alloc_skb(info->dst_sk, len, info->snd_portid, flags);
+}
+EXPORT_SYMBOL_GPL(genlmsg_new_unicast);
+
+/**
* genlmsg_put - Add generic netlink header to netlink message
* @skb: socket buffer holding the message
* @portid: netlink portid the message is addressed to
@@ -541,7 +557,7 @@ static int genl_family_rcv_msg(struct genl_family *family,
return -EOPNOTSUPP;
if ((ops->flags & GENL_ADMIN_PERM) &&
- !capable(CAP_NET_ADMIN))
+ !netlink_capable(skb, CAP_NET_ADMIN))
return -EPERM;
if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
@@ -600,6 +616,7 @@ static int genl_family_rcv_msg(struct genl_family *family,
info.genlhdr = nlmsg_data(nlh);
info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
info.attrs = attrbuf;
+ info.dst_sk = skb->sk;
genl_info_net_set(&info, net);
memset(&info.user_ptr, 0, sizeof(info.user_ptr));
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-14 02:27:33 +0000