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-rw-r--r--net/unix/diag.c342
1 files changed, 342 insertions, 0 deletions
diff --git a/net/unix/diag.c b/net/unix/diag.c
new file mode 100644
index 0000000000..616b55c5b8
--- /dev/null
+++ b/net/unix/diag.c
@@ -0,0 +1,342 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#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 <linux/uidgid.h>
+#include <net/netlink.h>
+#include <net/af_unix.h>
+#include <net/tcp_states.h>
+#include <net/sock.h>
+
+static int sk_diag_dump_name(struct sock *sk, struct sk_buff *nlskb)
+{
+ /* might or might not have a hash table lock */
+ struct unix_address *addr = smp_load_acquire(&unix_sk(sk)->addr);
+
+ if (!addr)
+ return 0;
+
+ return nla_put(nlskb, UNIX_DIAG_NAME,
+ addr->len - offsetof(struct sockaddr_un, sun_path),
+ addr->name->sun_path);
+}
+
+static int sk_diag_dump_vfs(struct sock *sk, struct sk_buff *nlskb)
+{
+ struct dentry *dentry = unix_sk(sk)->path.dentry;
+
+ if (dentry) {
+ struct unix_diag_vfs uv = {
+ .udiag_vfs_ino = d_backing_inode(dentry)->i_ino,
+ .udiag_vfs_dev = dentry->d_sb->s_dev,
+ };
+
+ return nla_put(nlskb, UNIX_DIAG_VFS, sizeof(uv), &uv);
+ }
+
+ return 0;
+}
+
+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);
+
+ return nla_put_u32(nlskb, UNIX_DIAG_PEER, ino);
+ }
+
+ return 0;
+}
+
+static int sk_diag_dump_icons(struct sock *sk, struct sk_buff *nlskb)
+{
+ struct sk_buff *skb;
+ struct nlattr *attr;
+ u32 *buf;
+ int i;
+
+ if (sk->sk_state == TCP_LISTEN) {
+ spin_lock(&sk->sk_receive_queue.lock);
+
+ attr = nla_reserve(nlskb, UNIX_DIAG_ICONS,
+ sk->sk_receive_queue.qlen * sizeof(u32));
+ if (!attr)
+ goto errout;
+
+ buf = nla_data(attr);
+ 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;
+
+errout:
+ 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;
+
+ 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 nla_put(nlskb, UNIX_DIAG_RQLEN, sizeof(rql), &rql);
+}
+
+static int sk_diag_dump_uid(struct sock *sk, struct sk_buff *nlskb,
+ struct user_namespace *user_ns)
+{
+ uid_t uid = from_kuid_munged(user_ns, sock_i_uid(sk));
+ return nla_put(nlskb, UNIX_DIAG_UID, sizeof(uid_t), &uid);
+}
+
+static int sk_diag_fill(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
+ struct user_namespace *user_ns,
+ u32 portid, u32 seq, u32 flags, int sk_ino)
+{
+ struct nlmsghdr *nlh;
+ struct unix_diag_msg *rep;
+
+ nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rep),
+ flags);
+ if (!nlh)
+ return -EMSGSIZE;
+
+ rep = nlmsg_data(nlh);
+ rep->udiag_family = AF_UNIX;
+ rep->udiag_type = sk->sk_type;
+ rep->udiag_state = sk->sk_state;
+ rep->pad = 0;
+ 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 out_nlmsg_trim;
+
+ if ((req->udiag_show & UDIAG_SHOW_VFS) &&
+ sk_diag_dump_vfs(sk, skb))
+ goto out_nlmsg_trim;
+
+ if ((req->udiag_show & UDIAG_SHOW_PEER) &&
+ sk_diag_dump_peer(sk, skb))
+ goto out_nlmsg_trim;
+
+ if ((req->udiag_show & UDIAG_SHOW_ICONS) &&
+ sk_diag_dump_icons(sk, skb))
+ goto out_nlmsg_trim;
+
+ if ((req->udiag_show & UDIAG_SHOW_RQLEN) &&
+ sk_diag_show_rqlen(sk, skb))
+ goto out_nlmsg_trim;
+
+ if ((req->udiag_show & UDIAG_SHOW_MEMINFO) &&
+ sock_diag_put_meminfo(sk, skb, UNIX_DIAG_MEMINFO))
+ goto out_nlmsg_trim;
+
+ if (nla_put_u8(skb, UNIX_DIAG_SHUTDOWN, sk->sk_shutdown))
+ goto out_nlmsg_trim;
+
+ if ((req->udiag_show & UDIAG_SHOW_UID) &&
+ sk_diag_dump_uid(sk, skb, user_ns))
+ goto out_nlmsg_trim;
+
+ nlmsg_end(skb, nlh);
+ return 0;
+
+out_nlmsg_trim:
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
+}
+
+static int sk_diag_dump(struct sock *sk, struct sk_buff *skb, struct unix_diag_req *req,
+ struct user_namespace *user_ns,
+ u32 portid, 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, user_ns, portid, seq, flags, sk_ino);
+}
+
+static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct net *net = sock_net(skb->sk);
+ int num, s_num, slot, s_slot;
+ struct unix_diag_req *req;
+
+ req = nlmsg_data(cb->nlh);
+
+ s_slot = cb->args[0];
+ num = s_num = cb->args[1];
+
+ for (slot = s_slot; slot < UNIX_HASH_SIZE; s_num = 0, slot++) {
+ struct sock *sk;
+
+ num = 0;
+ spin_lock(&net->unx.table.locks[slot]);
+ sk_for_each(sk, &net->unx.table.buckets[slot]) {
+ if (num < s_num)
+ goto next;
+ if (!(req->udiag_states & (1 << sk->sk_state)))
+ goto next;
+ if (sk_diag_dump(sk, skb, req, sk_user_ns(skb->sk),
+ NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq,
+ NLM_F_MULTI) < 0) {
+ spin_unlock(&net->unx.table.locks[slot]);
+ goto done;
+ }
+next:
+ num++;
+ }
+ spin_unlock(&net->unx.table.locks[slot]);
+ }
+done:
+ cb->args[0] = slot;
+ cb->args[1] = num;
+
+ return skb->len;
+}
+
+static struct sock *unix_lookup_by_ino(struct net *net, unsigned int ino)
+{
+ struct sock *sk;
+ int i;
+
+ for (i = 0; i < UNIX_HASH_SIZE; i++) {
+ spin_lock(&net->unx.table.locks[i]);
+ sk_for_each(sk, &net->unx.table.buckets[i]) {
+ if (ino == sock_i_ino(sk)) {
+ sock_hold(sk);
+ spin_unlock(&net->unx.table.locks[i]);
+ return sk;
+ }
+ }
+ spin_unlock(&net->unx.table.locks[i]);
+ }
+ return NULL;
+}
+
+static int unix_diag_get_exact(struct sk_buff *in_skb,
+ const struct nlmsghdr *nlh,
+ struct unix_diag_req *req)
+{
+ struct net *net = sock_net(in_skb->sk);
+ unsigned int extra_len;
+ struct sk_buff *rep;
+ struct sock *sk;
+ int err;
+
+ err = -EINVAL;
+ if (req->udiag_ino == 0)
+ goto out_nosk;
+
+ sk = unix_lookup_by_ino(net, 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 = nlmsg_new(sizeof(struct unix_diag_msg) + extra_len, GFP_KERNEL);
+ if (!rep)
+ goto out;
+
+ err = sk_diag_fill(sk, rep, req, sk_user_ns(NETLINK_CB(in_skb).sk),
+ NETLINK_CB(in_skb).portid,
+ nlh->nlmsg_seq, 0, req->udiag_ino);
+ if (err < 0) {
+ nlmsg_free(rep);
+ extra_len += 256;
+ if (extra_len >= PAGE_SIZE)
+ goto out;
+
+ goto again;
+ }
+ err = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid);
+
+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) {
+ struct netlink_dump_control c = {
+ .dump = unix_diag_dump,
+ };
+ return netlink_dump_start(sock_net(skb->sk)->diag_nlsk, skb, h, &c);
+ } else
+ return unix_diag_get_exact(skb, h, nlmsg_data(h));
+}
+
+static const 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 */);