summaryrefslogtreecommitdiff
path: root/net/netlink
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
commit8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be (patch)
treee9891aa6c295060d065adffd610c4f49ecf884f3 /net/netlink
parenta71852147516bc1cb5b0b3cbd13639bfd4022dc8 (diff)
Linux-libre 4.3.2-gnu
Diffstat (limited to 'net/netlink')
-rw-r--r--net/netlink/af_netlink.c96
1 files changed, 67 insertions, 29 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index a133d16eb..fafe33bdb 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -84,6 +84,7 @@ struct listeners {
#define NETLINK_F_BROADCAST_SEND_ERROR 0x4
#define NETLINK_F_RECV_NO_ENOBUFS 0x8
#define NETLINK_F_LISTEN_ALL_NSID 0x10
+#define NETLINK_F_CAP_ACK 0x20
static inline int netlink_is_kernel(struct sock *sk)
{
@@ -610,16 +611,6 @@ netlink_current_frame(const struct netlink_ring *ring,
return netlink_lookup_frame(ring, ring->head, status);
}
-static struct nl_mmap_hdr *
-netlink_previous_frame(const struct netlink_ring *ring,
- enum nl_mmap_status status)
-{
- unsigned int prev;
-
- prev = ring->head ? ring->head - 1 : ring->frame_max;
- return netlink_lookup_frame(ring, prev, status);
-}
-
static void netlink_increment_head(struct netlink_ring *ring)
{
ring->head = ring->head != ring->frame_max ? ring->head + 1 : 0;
@@ -627,11 +618,11 @@ static void netlink_increment_head(struct netlink_ring *ring)
static void netlink_forward_ring(struct netlink_ring *ring)
{
- unsigned int head = ring->head, pos = head;
+ unsigned int head = ring->head;
const struct nl_mmap_hdr *hdr;
do {
- hdr = __netlink_lookup_frame(ring, pos);
+ hdr = __netlink_lookup_frame(ring, ring->head);
if (hdr->nm_status == NL_MMAP_STATUS_UNUSED)
break;
if (hdr->nm_status != NL_MMAP_STATUS_SKIP)
@@ -640,6 +631,21 @@ static void netlink_forward_ring(struct netlink_ring *ring)
} while (ring->head != head);
}
+static bool netlink_has_valid_frame(struct netlink_ring *ring)
+{
+ unsigned int head = ring->head, pos = head;
+ const struct nl_mmap_hdr *hdr;
+
+ do {
+ hdr = __netlink_lookup_frame(ring, pos);
+ if (hdr->nm_status == NL_MMAP_STATUS_VALID)
+ return true;
+ pos = pos != 0 ? pos - 1 : ring->frame_max;
+ } while (pos != head);
+
+ return false;
+}
+
static bool netlink_dump_space(struct netlink_sock *nlk)
{
struct netlink_ring *ring = &nlk->rx_ring;
@@ -685,13 +691,19 @@ static unsigned int netlink_poll(struct file *file, struct socket *sock,
mask = datagram_poll(file, sock, wait);
- spin_lock_bh(&sk->sk_receive_queue.lock);
- if (nlk->rx_ring.pg_vec) {
- netlink_forward_ring(&nlk->rx_ring);
- if (!netlink_previous_frame(&nlk->rx_ring, NL_MMAP_STATUS_UNUSED))
- mask |= POLLIN | POLLRDNORM;
+ /* We could already have received frames in the normal receive
+ * queue, that will show up as NL_MMAP_STATUS_COPY in the ring,
+ * so if mask contains pollin/etc already, there's no point
+ * walking the ring.
+ */
+ if ((mask & (POLLIN | POLLRDNORM)) != (POLLIN | POLLRDNORM)) {
+ spin_lock_bh(&sk->sk_receive_queue.lock);
+ if (nlk->rx_ring.pg_vec) {
+ if (netlink_has_valid_frame(&nlk->rx_ring))
+ mask |= POLLIN | POLLRDNORM;
+ }
+ spin_unlock_bh(&sk->sk_receive_queue.lock);
}
- spin_unlock_bh(&sk->sk_receive_queue.lock);
spin_lock_bh(&sk->sk_write_queue.lock);
if (nlk->tx_ring.pg_vec) {
@@ -1864,15 +1876,16 @@ retry:
}
EXPORT_SYMBOL(netlink_unicast);
-struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size,
- u32 dst_portid, gfp_t gfp_mask)
+struct sk_buff *__netlink_alloc_skb(struct sock *ssk, unsigned int size,
+ unsigned int ldiff, u32 dst_portid,
+ gfp_t gfp_mask)
{
#ifdef CONFIG_NETLINK_MMAP
+ unsigned int maxlen, linear_size;
struct sock *sk = NULL;
struct sk_buff *skb;
struct netlink_ring *ring;
struct nl_mmap_hdr *hdr;
- unsigned int maxlen;
sk = netlink_getsockbyportid(ssk, dst_portid);
if (IS_ERR(sk))
@@ -1883,7 +1896,11 @@ 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)
+ /* We need to account the full linear size needed as a ring
+ * slot cannot have non-linear parts.
+ */
+ linear_size = size + ldiff;
+ if (ring->frame_size - NL_MMAP_HDRLEN < linear_size)
goto out_put;
skb = alloc_skb_head(gfp_mask);
@@ -1897,13 +1914,14 @@ struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size,
/* check again under lock */
maxlen = ring->frame_size - NL_MMAP_HDRLEN;
- if (maxlen < size)
+ if (maxlen < linear_size)
goto out_free;
netlink_forward_ring(ring);
hdr = netlink_current_frame(ring, NL_MMAP_STATUS_UNUSED);
if (hdr == NULL)
goto err2;
+
netlink_ring_setup_skb(skb, sk, ring, hdr);
netlink_set_status(hdr, NL_MMAP_STATUS_RESERVED);
atomic_inc(&ring->pending);
@@ -1929,7 +1947,7 @@ out:
#endif
return alloc_skb(size, gfp_mask);
}
-EXPORT_SYMBOL_GPL(netlink_alloc_skb);
+EXPORT_SYMBOL_GPL(__netlink_alloc_skb);
int netlink_has_listeners(struct sock *sk, unsigned int group)
{
@@ -2290,6 +2308,13 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname,
nlk->flags &= ~NETLINK_F_LISTEN_ALL_NSID;
err = 0;
break;
+ case NETLINK_CAP_ACK:
+ if (val)
+ nlk->flags |= NETLINK_F_CAP_ACK;
+ else
+ nlk->flags &= ~NETLINK_F_CAP_ACK;
+ err = 0;
+ break;
default:
err = -ENOPROTOOPT;
}
@@ -2346,7 +2371,7 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname,
int pos, idx, shift;
err = 0;
- netlink_table_grab();
+ netlink_lock_table();
for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) {
if (len - pos < sizeof(u32))
break;
@@ -2361,9 +2386,19 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname,
}
if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen))
err = -EFAULT;
- netlink_table_ungrab();
+ netlink_unlock_table();
break;
}
+ case NETLINK_CAP_ACK:
+ if (len < sizeof(int))
+ return -EINVAL;
+ len = sizeof(int);
+ val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0;
+ if (put_user(len, optlen) ||
+ put_user(val, optval))
+ return -EFAULT;
+ err = 0;
+ break;
default:
err = -ENOPROTOOPT;
}
@@ -2918,9 +2953,12 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
struct nlmsghdr *rep;
struct nlmsgerr *errmsg;
size_t payload = sizeof(*errmsg);
+ struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk);
- /* error messages get the original request appened */
- if (err)
+ /* Error messages get the original request appened, unless the user
+ * requests to cap the error message.
+ */
+ if (!(nlk->flags & NETLINK_F_CAP_ACK) && err)
payload += nlmsg_len(nlh);
skb = netlink_alloc_skb(in_skb->sk, nlmsg_total_size(payload),
@@ -2943,7 +2981,7 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
NLMSG_ERROR, payload, 0);
errmsg = nlmsg_data(rep);
errmsg->error = err;
- memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh));
+ memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh));
netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT);
}
EXPORT_SYMBOL(netlink_ack);