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Message-Id: <1290450982-17480-3-git-send-email-alban.crequy@collabora.co.uk>
Date: Mon, 22 Nov 2010 18:36:16 +0000
From: Alban Crequy <alban.crequy@...labora.co.uk>
To: Alban Crequy <alban.crequy@...labora.co.uk>
Cc: "David S. Miller" <davem@...emloft.net>,
Eric Dumazet <eric.dumazet@...il.com>,
Stephen Hemminger <shemminger@...tta.com>,
Cyrill Gorcunov <gorcunov@...nvz.org>,
Alexey Dobriyan <adobriyan@...il.com>,
Lennart Poettering <lennart@...ttering.net>,
Kay Sievers <kay.sievers@...y.org>,
Ian Molton <ian.molton@...labora.co.uk>,
netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
Alban Crequy <alban.crequy@...labora.co.uk>
Subject: [PATCH 3/9] AF_UNIX: create, join and leave multicast groups with setsockopt
Multicast is implemented on SOCK_DGRAM and SOCK_SEQPACKET Unix sockets.
An userspace application can create a multicast group with:
struct unix_mreq mreq;
mreq.address.sun_family = AF_UNIX;
mreq.address.sun_path[0] = '\0';
strcpy(mreq.address.sun_path + 1, "socket-address");
mreq.flags = 0;
sockfd = socket(AF_UNIX, SOCK_DGRAM, 0);
ret = setsockopt(sockfd, SOL_UNIX, UNIX_CREATE_GROUP, &mreq, sizeof(mreq));
Then a multicast group can be joined and left with:
ret = setsockopt(sockfd, SOL_UNIX, UNIX_JOIN_GROUP, &mreq, sizeof(mreq));
ret = setsockopt(sockfd, SOL_UNIX, UNIX_LEAVE_GROUP, &mreq, sizeof(mreq));
A socket can be a member of several multicast group.
Signed-off-by: Alban Crequy <alban.crequy@...labora.co.uk>
---
include/net/af_unix.h | 31 +++++++
net/unix/af_unix.c | 217 ++++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 247 insertions(+), 1 deletions(-)
diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index 90c9e28..bf114d5 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -40,6 +40,18 @@ struct unix_skb_parms {
spin_lock_nested(&unix_sk(s)->lock, \
SINGLE_DEPTH_NESTING)
+#define UNIX_MREQ_LOOPBACK 0x01
+struct unix_mreq
+{
+ struct sockaddr_un address;
+ unsigned int flags;
+};
+
+/* UNIX socket options */
+#define UNIX_CREATE_GROUP 1
+#define UNIX_JOIN_GROUP 2
+#define UNIX_LEAVE_GROUP 3
+
#ifdef __KERNEL__
/* The AF_UNIX socket */
struct unix_sock {
@@ -56,8 +68,27 @@ struct unix_sock {
spinlock_t lock;
unsigned int gc_candidate : 1;
unsigned int gc_maybe_cycle : 1;
+ unsigned int is_mcast_addr : 1;
+
+ /* These multicast fields are protected by the global spinlock
+ * unix_multicast_lock */
+ struct hlist_head mcast_subscriptions;
+ struct hlist_head mcast_members;
+ int mcast_subscriptions_cnt;
+ int mcast_members_cnt;
+
struct socket_wq peer_wq;
};
+
+struct unix_mcast
+{
+ struct unix_sock *member;
+ struct unix_sock *addr;
+ unsigned int flags;
+ struct hlist_node subscription_node;
+ struct hlist_node member_node;
+};
+
#define unix_sk(__sk) ((struct unix_sock *)__sk)
#define peer_wait peer_wq.wait
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 6eca106..2278829 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -379,6 +379,9 @@ static int unix_release_sock(struct sock *sk, int embrion)
struct sock *skpair;
struct sk_buff *skb;
int state;
+ struct unix_mcast *node;
+ struct hlist_node *pos;
+ struct hlist_node *pos_tmp;
unix_remove_socket(sk);
@@ -392,6 +395,24 @@ static int unix_release_sock(struct sock *sk, int embrion)
u->mnt = NULL;
state = sk->sk_state;
sk->sk_state = TCP_CLOSE;
+ spin_lock(&unix_multicast_lock);
+ hlist_for_each_entry_safe(node, pos, pos_tmp, &u->mcast_subscriptions,
+ subscription_node) {
+ hlist_del(&node->member_node);
+ hlist_del(&node->subscription_node);
+ node->addr->mcast_members_cnt--;
+ node->member->mcast_subscriptions_cnt--;
+ kfree(node);
+ }
+ hlist_for_each_entry_safe(node, pos, pos_tmp, &u->mcast_members,
+ member_node) {
+ hlist_del(&node->member_node);
+ hlist_del(&node->subscription_node);
+ node->addr->mcast_members_cnt--;
+ node->member->mcast_subscriptions_cnt--;
+ kfree(node);
+ }
+ spin_unlock(&unix_multicast_lock);
unix_state_unlock(sk);
wake_up_interruptible_all(&u->peer_wait);
@@ -631,6 +652,8 @@ static struct sock *unix_create1(struct net *net, struct socket *sock)
atomic_long_set(&u->inflight, 0);
INIT_LIST_HEAD(&u->link);
mutex_init(&u->readlock); /* single task reading lock */
+ INIT_HLIST_HEAD(&u->mcast_subscriptions);
+ INIT_HLIST_HEAD(&u->mcast_members);
init_waitqueue_head(&u->peer_wait);
unix_insert_socket(unix_sockets_unbound, sk);
out:
@@ -1535,10 +1558,202 @@ out:
}
+static int unix_mc_create(struct socket *sock, struct unix_mreq *mreq)
+{
+ struct sock *other;
+ int err;
+ unsigned hash;
+ int namelen;
+
+ if (mreq->address.sun_family != AF_UNIX ||
+ mreq->address.sun_path[0] != '\0')
+ return -EINVAL;
+
+ err = unix_mkname(&mreq->address, sizeof(struct sockaddr_un), &hash);
+ if (err < 0)
+ return err;
+
+ namelen = err;
+ other = unix_find_other(sock_net(sock->sk), &mreq->address, namelen,
+ sock->type, hash, &err);
+ if (other)
+ return -EADDRINUSE;
+
+ err = sock->ops->bind(sock,
+ (struct sockaddr*)&mreq->address,
+ sizeof(struct sockaddr_un));
+ if (err < 0)
+ return err;
+
+ unix_state_lock(sock->sk);
+ unix_sk(sock->sk)->is_mcast_addr = 1;
+ unix_state_unlock(sock->sk);
+
+ return 0;
+}
+
+
+static int unix_mc_join(struct socket *sock, struct unix_mreq *mreq)
+{
+ struct unix_sock *u = unix_sk(sock->sk);
+ struct sock *other;
+ struct unix_sock *otheru;
+ struct unix_mcast *node;
+ int err;
+ unsigned hash;
+ int namelen;
+
+ if (mreq->address.sun_family != AF_UNIX ||
+ mreq->address.sun_path[0] != '\0')
+ return -EINVAL;
+
+ err = unix_autobind(sock);
+ if (err < 0)
+ return err;
+
+ err = unix_mkname(&mreq->address, sizeof(struct sockaddr_un), &hash);
+ if (err < 0)
+ return err;
+
+ namelen = err;
+ other = unix_find_other(sock_net(sock->sk), &mreq->address, namelen,
+ sock->type, hash, &err);
+ if (!other)
+ return -EINVAL;
+
+ if (other && !unix_sk(other)->is_mcast_addr) {
+ err = -EADDRINUSE;
+ goto sock_put_out;
+ }
+
+ otheru = unix_sk(other);
+
+ node = kmalloc(sizeof(struct unix_mcast), GFP_KERNEL);
+ if (!node) {
+ err = -ENOMEM;
+ goto sock_put_out;
+ }
+ node->member = u;
+ node->addr = otheru;
+ node->flags = mreq->flags;
+
+ spin_lock(&unix_multicast_lock);
+ hlist_add_head(&node->member_node, &otheru->mcast_members);
+ hlist_add_head(&node->subscription_node, &u->mcast_subscriptions);
+ otheru->mcast_members_cnt++;
+ u->mcast_subscriptions_cnt++;
+ spin_unlock(&unix_multicast_lock);
+
+ return 0;
+
+sock_put_out:
+ sock_put(other);
+ return err;
+}
+
+
+static int unix_mc_leave(struct socket *sock, struct unix_mreq *mreq)
+{
+ struct unix_sock *u = unix_sk(sock->sk);
+ struct sock *other;
+ struct unix_sock *otheru;
+ struct unix_mcast *node;
+ struct hlist_node *pos;
+ int err;
+ unsigned hash;
+ int namelen;
+
+ if (mreq->address.sun_family != AF_UNIX ||
+ mreq->address.sun_path[0] != '\0')
+ return -EINVAL;
+
+ err = unix_mkname(&mreq->address, sizeof(struct sockaddr_un), &hash);
+ if (err < 0)
+ return err;
+
+ namelen = err;
+ other = unix_find_other(sock_net(sock->sk), &mreq->address, namelen,
+ sock->type, hash, &err);
+ if (!other)
+ return -EINVAL;
+
+ otheru = unix_sk(other);
+
+ if (!otheru->is_mcast_addr) {
+ err = -EINVAL;
+ goto sock_put_out;
+ }
+
+ spin_lock(&unix_multicast_lock);
+
+ hlist_for_each_entry(node, pos, &u->mcast_subscriptions,
+ subscription_node) {
+ if (node->addr == otheru)
+ break;
+ }
+
+ if (!pos) {
+ spin_unlock(&unix_multicast_lock);
+ err = -EINVAL;
+ goto sock_put_out;
+ }
+
+ hlist_del(&node->member_node);
+ hlist_del(&node->subscription_node);
+ otheru->mcast_members_cnt--;
+ u->mcast_subscriptions_cnt--;
+ spin_unlock(&unix_multicast_lock);
+ kfree(node);
+ err = 0;
+
+sock_put_out:
+ sock_put(other);
+ return err;
+}
+
+
static int unix_setsockopt(struct socket *sock, int level, int optname,
char __user *optval, unsigned int optlen)
{
- return -EOPNOTSUPP;
+ struct unix_mreq mreq;
+ int err = 0;
+
+ if (level != SOL_UNIX)
+ return -ENOPROTOOPT;
+
+ switch (optname) {
+ case UNIX_CREATE_GROUP:
+ case UNIX_JOIN_GROUP:
+ case UNIX_LEAVE_GROUP:
+ if (optlen < sizeof(struct unix_mreq))
+ return -EINVAL;
+ if (copy_from_user(&mreq, optval, sizeof(struct unix_mreq)))
+ return -EFAULT;
+ break;
+
+ default:
+ break;
+ }
+
+ switch (optname) {
+ case UNIX_CREATE_GROUP:
+ err = unix_mc_create(sock, &mreq);
+ break;
+
+ case UNIX_JOIN_GROUP:
+ err = unix_mc_join(sock, &mreq);
+ break;
+
+ case UNIX_LEAVE_GROUP:
+ err = unix_mc_leave(sock, &mreq);
+ break;
+
+ default:
+ err = -ENOPROTOOPT;
+ break;
+ }
+
+ return err;
}
--
1.7.1
--
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