4 files changed, 381 insertions, 26 deletions

diff --git a/net/unix/Kconfig b/net/unix/Kconfig
index 5a69733bcdad..c2128b10e5f9 100644
--- a/net/unix/Kconfig
+++ b/net/unix/Kconfig
@@ -19,3 +19,10 @@ config UNIX
 
           Say Y unless you know what you are doing.
 
+config UNIX_DIAG
+        tristate "UNIX: socket monitoring interface"
+        depends on UNIX
+        default UNIX
+        ---help---
+          Support for UNIX socket monitoring interface used by the ss tool.
+          If unsure, say Y.
diff --git a/net/unix/Makefile b/net/unix/Makefile
index b852a2bde9a8..b663c607b1c6 100644
--- a/net/unix/Makefile
+++ b/net/unix/Makefile
@@ -6,3 +6,6 @@ obj-$(CONFIG_UNIX)	+= unix.o
 
 unix-y                  := af_unix.o garbage.o
 unix-$(CONFIG_SYSCTL)   += sysctl_net_unix.o
+
+obj-$(CONFIG_UNIX_DIAG) += unix_diag.o
+unix_diag-y             := diag.o
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index b595a3d8679f..7cc3d7b23d1c 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -115,8 +115,10 @@
 #include <net/checksum.h>
 #include <linux/security.h>
 
-static struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1];
-static DEFINE_SPINLOCK(unix_table_lock);
+struct hlist_head unix_socket_table[UNIX_HASH_SIZE + 1];
+EXPORT_SYMBOL_GPL(unix_socket_table);
+DEFINE_SPINLOCK(unix_table_lock);
+EXPORT_SYMBOL_GPL(unix_table_lock);
 static atomic_long_t unix_nr_socks;
 
 #define unix_sockets_unbound    (&unix_socket_table[UNIX_HASH_SIZE])
@@ -172,7 +174,7 @@ static inline int unix_recvq_full(struct sock const *sk)
         return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog;
 }
 
-static struct sock *unix_peer_get(struct sock *s)
+struct sock *unix_peer_get(struct sock *s)
 {
         struct sock *peer;
 
@@ -183,6 +185,7 @@ static struct sock *unix_peer_get(struct sock *s)
         unix_state_unlock(s);
         return peer;
 }
+EXPORT_SYMBOL_GPL(unix_peer_get);
 
 static inline void unix_release_addr(struct unix_address *addr)
 {
@@ -2062,6 +2065,36 @@ static int unix_shutdown(struct socket *sock, int mode)
         return 0;
 }
 
+long unix_inq_len(struct sock *sk)
+{
+        struct sk_buff *skb;
+        long amount = 0;
+
+        if (sk->sk_state == TCP_LISTEN)
+                return -EINVAL;
+
+        spin_lock(&sk->sk_receive_queue.lock);
+        if (sk->sk_type == SOCK_STREAM ||
+            sk->sk_type == SOCK_SEQPACKET) {
+                skb_queue_walk(&sk->sk_receive_queue, skb)
+                        amount += skb->len;
+        } else {
+                skb = skb_peek(&sk->sk_receive_queue);
+                if (skb)
+                        amount = skb->len;
+        }
+        spin_unlock(&sk->sk_receive_queue.lock);
+
+        return amount;
+}
+EXPORT_SYMBOL_GPL(unix_inq_len);
+
+long unix_outq_len(struct sock *sk)
+{
+        return sk_wmem_alloc_get(sk);
+}
+EXPORT_SYMBOL_GPL(unix_outq_len);
+
 static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 {
         struct sock *sk = sock->sk;
@@ -2070,33 +2103,16 @@ static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 
         switch (cmd) {
         case SIOCOUTQ:
-                amount = sk_wmem_alloc_get(sk);
+                amount = unix_outq_len(sk);
                 err = put_user(amount, (int __user *)arg);
                 break;
         case SIOCINQ:
-                {
-                        struct sk_buff *skb;
-
-                        if (sk->sk_state == TCP_LISTEN) {
-                                err = -EINVAL;
-                                break;
-                        }
-
-                        spin_lock(&sk->sk_receive_queue.lock);
-                        if (sk->sk_type == SOCK_STREAM ||
-                            sk->sk_type == SOCK_SEQPACKET) {
-                                skb_queue_walk(&sk->sk_receive_queue, skb)
-                                        amount += skb->len;
-                        } else {
-                                skb = skb_peek(&sk->sk_receive_queue);
-                                if (skb)
-                                        amount = skb->len;
-                        }
-                        spin_unlock(&sk->sk_receive_queue.lock);
+                amount = unix_inq_len(sk);
+                if (amount < 0)
+                        err = amount;
+                else
                         err = put_user(amount, (int __user *)arg);
-                        break;
-                }
-
+                break;
         default:
                 err = -ENOIOCTLCMD;
                 break;
diff --git a/net/unix/diag.c b/net/unix/diag.c
new file mode 100644
index 000000000000..6b7697fd911b
--- /dev/null
+++ b/net/unix/diag.c
@@ -0,0 +1,329 @@
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/sock_diag.h>
+#include <linux/unix_diag.h>
+#include <linux/skbuff.h>
+#include <linux/module.h>
+#include <net/netlink.h>
+#include <net/af_unix.h>
+#include <net/tcp_states.h>
+
+#define UNIX_DIAG_PUT(skb, attrtype, attrlen) \
+        RTA_DATA(__RTA_PUT(skb, attrtype, attrlen))
+
+static int sk_diag_dump_name(struct sock *sk, struct sk_buff *nlskb)
+{
+        struct unix_address *addr = unix_sk(sk)->addr;
+        char *s;
+
+        if (addr) {
+                s = UNIX_DIAG_PUT(nlskb, UNIX_DIAG_NAME, addr->len - sizeof(short));
+                memcpy(s, addr->name->sun_path, addr->len - sizeof(short));
+        }
+
+        return 0;
+
+rtattr_failure:
+        return -EMSGSIZE;
+}
+
+static int sk_diag_dump_vfs(struct sock *sk, struct sk_buff *nlskb)
+{
+        struct dentry *dentry = unix_sk(sk)->dentry;
+        struct unix_diag_vfs *uv;
+
+        if (dentry) {
+                uv = UNIX_DIAG_PUT(nlskb, UNIX_DIAG_VFS, sizeof(*uv));
+                uv->udiag_vfs_ino = dentry->d_inode->i_ino;
+                uv->udiag_vfs_dev = dentry->d_sb->s_dev;
+        }
+
+        return 0;
+
+rtattr_failure:
+        return -EMSGSIZE;
+}
+
+static int sk_diag_dump_peer(struct sock *sk, struct sk_buff *nlskb)
+{
+        struct sock *peer;
+        int ino;
+
+        peer = unix_peer_get(sk);
+        if (peer) {
+                unix_state_lock(peer);
+                ino = sock_i_ino(peer);
+                unix_state_unlock(peer);
+                sock_put(peer);
+
+                RTA_PUT_U32(nlskb, UNIX_DIAG_PEER, ino);
+        }
+
+        return 0;
+rtattr_failure:
+        return -EMSGSIZE;
+}
+
+static int sk_diag_dump_icons(struct sock *sk, struct sk_buff *nlskb)
+{
+        struct sk_buff *skb;
+        u32 *buf;
+        int i;
+
+        if (sk->sk_state == TCP_LISTEN) {
+                spin_lock(&sk->sk_receive_queue.lock);
+                buf = UNIX_DIAG_PUT(nlskb, UNIX_DIAG_ICONS,
+                                sk->sk_receive_queue.qlen * sizeof(u32));
+                i = 0;
+                skb_queue_walk(&sk->sk_receive_queue, skb) {
+                        struct sock *req, *peer;
+
+                        req = skb->sk;
+                        /*
+                         * The state lock is outer for the same sk's
+                         * queue lock. With the other's queue locked it's
+                         * OK to lock the state.
+                         */
+                        unix_state_lock_nested(req);
+                        peer = unix_sk(req)->peer;
+                        buf[i++] = (peer ? sock_i_ino(peer) : 0);
+                        unix_state_unlock(req);
+                }
+                spin_unlock(&sk->sk_receive_queue.lock);
+        }
+
+        return 0;
+
+rtattr_failure:
+        spin_unlock(&sk->sk_receive_queue.lock);
+        return -EMSGSIZE;
+}
+
+static int sk_diag_show_rqlen(struct sock *sk, struct sk_buff *nlskb)
+{
+        struct unix_diag_rqlen *rql;
+
+        rql = UNIX_DIAG_PUT(nlskb, UNIX_DIAG_RQLEN, sizeof(*rql));
+
+        if (sk->sk_state == TCP_LISTEN) {
+                rql->udiag_rqueue = sk->sk_receive_queue.qlen;
+                rql->udiag_wqueue = sk->sk_max_ack_backlog;
+        } else {
+                rql->udiag_rqueue = (__u32)unix_inq_len(sk);
+                rql->udiag_wqueue = (__u32)unix_outq_len(sk);
+        }
+
+        return 0;
+
+rtattr_failure:
+        return -EMSGSIZE;
+}
+
+static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
+                u32 pid, u32 seq, u32 flags, int sk_ino)
+{
+        unsigned char *b = skb_tail_pointer(skb);
+        struct nlmsghdr *nlh;
+        struct unix_diag_msg *rep;
+
+        nlh = NLMSG_PUT(skb, pid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rep));
+        nlh->nlmsg_flags = flags;
+
+        rep = NLMSG_DATA(nlh);
+
+        rep->udiag_family = AF_UNIX;
+        rep->udiag_type = sk->sk_type;
+        rep->udiag_state = sk->sk_state;
+        rep->udiag_ino = sk_ino;
+        sock_diag_save_cookie(sk, rep->udiag_cookie);
+
+        if ((req->udiag_show & UDIAG_SHOW_NAME) &&
+            sk_diag_dump_name(sk, skb))
+                goto nlmsg_failure;
+
+        if ((req->udiag_show & UDIAG_SHOW_VFS) &&
+            sk_diag_dump_vfs(sk, skb))
+                goto nlmsg_failure;
+
+        if ((req->udiag_show & UDIAG_SHOW_PEER) &&
+            sk_diag_dump_peer(sk, skb))
+                goto nlmsg_failure;
+
+        if ((req->udiag_show & UDIAG_SHOW_ICONS) &&
+            sk_diag_dump_icons(sk, skb))
+                goto nlmsg_failure;
+
+        if ((req->udiag_show & UDIAG_SHOW_RQLEN) &&
+            sk_diag_show_rqlen(sk, skb))
+                goto nlmsg_failure;
+
+        if ((req->udiag_show & UDIAG_SHOW_MEMINFO) &&
+            sock_diag_put_meminfo(sk, skb, UNIX_DIAG_MEMINFO))
+                goto nlmsg_failure;
+
+        nlh->nlmsg_len = skb_tail_pointer(skb) - b;
+        return skb->len;
+
+nlmsg_failure:
+        nlmsg_trim(skb, b);
+        return -EMSGSIZE;
+}
+
+static int sk_diag_dump(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
+                u32 pid, u32 seq, u32 flags)
+{
+        int sk_ino;
+
+        unix_state_lock(sk);
+        sk_ino = sock_i_ino(sk);
+        unix_state_unlock(sk);
+
+        if (!sk_ino)
+                return 0;
+
+        return sk_diag_fill(sk, skb, req, pid, seq, flags, sk_ino);
+}
+
+static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+        struct unix_diag_req *req;
+        int num, s_num, slot, s_slot;
+
+        req = NLMSG_DATA(cb->nlh);
+
+        s_slot = cb->args[0];
+        num = s_num = cb->args[1];
+
+        spin_lock(&unix_table_lock);
+        for (slot = s_slot; slot <= UNIX_HASH_SIZE; s_num = 0, slot++) {
+                struct sock *sk;
+                struct hlist_node *node;
+
+                num = 0;
+                sk_for_each(sk, node, &unix_socket_table[slot]) {
+                        if (num < s_num)
+                                goto next;
+                        if (!(req->udiag_states & (1 << sk->sk_state)))
+                                goto next;
+                        if (sk_diag_dump(sk, skb, req,
+                                         NETLINK_CB(cb->skb).pid,
+                                         cb->nlh->nlmsg_seq,
+                                         NLM_F_MULTI) < 0)
+                                goto done;
+next:
+                        num++;
+                }
+        }
+done:
+        spin_unlock(&unix_table_lock);
+        cb->args[0] = slot;
+        cb->args[1] = num;
+
+        return skb->len;
+}
+
+static struct sock *unix_lookup_by_ino(int ino)
+{
+        int i;
+        struct sock *sk;
+
+        spin_lock(&unix_table_lock);
+        for (i = 0; i <= UNIX_HASH_SIZE; i++) {
+                struct hlist_node *node;
+
+                sk_for_each(sk, node, &unix_socket_table[i])
+                        if (ino == sock_i_ino(sk)) {
+                                sock_hold(sk);
+                                spin_unlock(&unix_table_lock);
+
+                                return sk;
+                        }
+        }
+
+        spin_unlock(&unix_table_lock);
+        return NULL;
+}
+
+static int unix_diag_get_exact(struct sk_buff *in_skb,
+                               const struct nlmsghdr *nlh,
+                               struct unix_diag_req *req)
+{
+        int err = -EINVAL;
+        struct sock *sk;
+        struct sk_buff *rep;
+        unsigned int extra_len;
+
+        if (req->udiag_ino == 0)
+                goto out_nosk;
+
+        sk = unix_lookup_by_ino(req->udiag_ino);
+        err = -ENOENT;
+        if (sk == NULL)
+                goto out_nosk;
+
+        err = sock_diag_check_cookie(sk, req->udiag_cookie);
+        if (err)
+                goto out;
+
+        extra_len = 256;
+again:
+        err = -ENOMEM;
+        rep = alloc_skb(NLMSG_SPACE((sizeof(struct unix_diag_msg) + extra_len)),
+                        GFP_KERNEL);
+        if (!rep)
+                goto out;
+
+        err = sk_diag_fill(sk, rep, req, NETLINK_CB(in_skb).pid,
+                           nlh->nlmsg_seq, 0, req->udiag_ino);
+        if (err < 0) {
+                kfree_skb(rep);
+                extra_len += 256;
+                if (extra_len >= PAGE_SIZE)
+                        goto out;
+
+                goto again;
+        }
+        err = netlink_unicast(sock_diag_nlsk, rep, NETLINK_CB(in_skb).pid,
+                              MSG_DONTWAIT);
+        if (err > 0)
+                err = 0;
+out:
+        if (sk)
+                sock_put(sk);
+out_nosk:
+        return err;
+}
+
+static int unix_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
+{
+        int hdrlen = sizeof(struct unix_diag_req);
+
+        if (nlmsg_len(h) < hdrlen)
+                return -EINVAL;
+
+        if (h->nlmsg_flags & NLM_F_DUMP)
+                return netlink_dump_start(sock_diag_nlsk, skb, h,
+                                          unix_diag_dump, NULL, 0);
+        else
+                return unix_diag_get_exact(skb, h, (struct unix_diag_req *)NLMSG_DATA(h));
+}
+
+static struct sock_diag_handler unix_diag_handler = {
+        .family = AF_UNIX,
+        .dump = unix_diag_handler_dump,
+};
+
+static int __init unix_diag_init(void)
+{
+        return sock_diag_register(&unix_diag_handler);
+}
+
+static void __exit unix_diag_exit(void)
+{
+        sock_diag_unregister(&unix_diag_handler);
+}
+
+module_init(unix_diag_init);
+module_exit(unix_diag_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 1 /* AF_LOCAL */);