kcm: Add statistics and proc interfaces

This patch adds various counters for KCM. These include counters for
messages and bytes received or sent, as well as counters for number of
attached/unattached TCP sockets and other error or edge events.

The statistics are exposed via a proc interface. /proc/net/kcm provides
statistics per KCM socket and per psock (attached TCP sockets).
/proc/net/kcm_stats provides aggregate statistics.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/kcm/kcmproc.c b/net/kcm/kcmproc.c
new file mode 100644
index 0000000..5eb9809
--- /dev/null
+++ b/net/kcm/kcmproc.c
@@ -0,0 +1,422 @@
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/proc_fs.h>
+#include <linux/rculist.h>
+#include <linux/seq_file.h>
+#include <linux/socket.h>
+#include <net/inet_sock.h>
+#include <net/kcm.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/tcp.h>
+
+#ifdef CONFIG_PROC_FS
+struct kcm_seq_muxinfo {
+	char				*name;
+	const struct file_operations	*seq_fops;
+	const struct seq_operations	seq_ops;
+};
+
+static struct kcm_mux *kcm_get_first(struct seq_file *seq)
+{
+	struct net *net = seq_file_net(seq);
+	struct kcm_net *knet = net_generic(net, kcm_net_id);
+
+	return list_first_or_null_rcu(&knet->mux_list,
+				      struct kcm_mux, kcm_mux_list);
+}
+
+static struct kcm_mux *kcm_get_next(struct kcm_mux *mux)
+{
+	struct kcm_net *knet = mux->knet;
+
+	return list_next_or_null_rcu(&knet->mux_list, &mux->kcm_mux_list,
+				     struct kcm_mux, kcm_mux_list);
+}
+
+static struct kcm_mux *kcm_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct net *net = seq_file_net(seq);
+	struct kcm_net *knet = net_generic(net, kcm_net_id);
+	struct kcm_mux *m;
+
+	list_for_each_entry_rcu(m, &knet->mux_list, kcm_mux_list) {
+		if (!pos)
+			return m;
+		--pos;
+	}
+	return NULL;
+}
+
+static void *kcm_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	void *p;
+
+	if (v == SEQ_START_TOKEN)
+		p = kcm_get_first(seq);
+	else
+		p = kcm_get_next(v);
+	++*pos;
+	return p;
+}
+
+static void *kcm_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(rcu)
+{
+	rcu_read_lock();
+
+	if (!*pos)
+		return SEQ_START_TOKEN;
+	else
+		return kcm_get_idx(seq, *pos - 1);
+}
+
+static void kcm_seq_stop(struct seq_file *seq, void *v)
+	__releases(rcu)
+{
+	rcu_read_unlock();
+}
+
+struct kcm_proc_mux_state {
+	struct seq_net_private p;
+	int idx;
+};
+
+static int kcm_seq_open(struct inode *inode, struct file *file)
+{
+	struct kcm_seq_muxinfo *muxinfo = PDE_DATA(inode);
+	int err;
+
+	err = seq_open_net(inode, file, &muxinfo->seq_ops,
+			   sizeof(struct kcm_proc_mux_state));
+	if (err < 0)
+		return err;
+	return err;
+}
+
+static void kcm_format_mux_header(struct seq_file *seq)
+{
+	struct net *net = seq_file_net(seq);
+	struct kcm_net *knet = net_generic(net, kcm_net_id);
+
+	seq_printf(seq,
+		   "*** KCM statistics (%d MUX) ****\n",
+		   knet->count);
+
+	seq_printf(seq,
+		   "%-14s %-10s %-16s %-10s %-16s %-8s %-8s %-8s %-8s %s",
+		   "Object",
+		   "RX-Msgs",
+		   "RX-Bytes",
+		   "TX-Msgs",
+		   "TX-Bytes",
+		   "Recv-Q",
+		   "Rmem",
+		   "Send-Q",
+		   "Smem",
+		   "Status");
+
+	/* XXX: pdsts header stuff here */
+	seq_puts(seq, "\n");
+}
+
+static void kcm_format_sock(struct kcm_sock *kcm, struct seq_file *seq,
+			    int i, int *len)
+{
+	seq_printf(seq,
+		   "   kcm-%-7u %-10llu %-16llu %-10llu %-16llu %-8d %-8d %-8d %-8s ",
+		   kcm->index,
+		   kcm->stats.rx_msgs,
+		   kcm->stats.rx_bytes,
+		   kcm->stats.tx_msgs,
+		   kcm->stats.tx_bytes,
+		   kcm->sk.sk_receive_queue.qlen,
+		   sk_rmem_alloc_get(&kcm->sk),
+		   kcm->sk.sk_write_queue.qlen,
+		   "-");
+
+	if (kcm->tx_psock)
+		seq_printf(seq, "Psck-%u ", kcm->tx_psock->index);
+
+	if (kcm->tx_wait)
+		seq_puts(seq, "TxWait ");
+
+	if (kcm->tx_wait_more)
+		seq_puts(seq, "WMore ");
+
+	if (kcm->rx_wait)
+		seq_puts(seq, "RxWait ");
+
+	seq_puts(seq, "\n");
+}
+
+static void kcm_format_psock(struct kcm_psock *psock, struct seq_file *seq,
+			     int i, int *len)
+{
+	seq_printf(seq,
+		   "   psock-%-5u %-10llu %-16llu %-10llu %-16llu %-8d %-8d %-8d %-8d ",
+		   psock->index,
+		   psock->stats.rx_msgs,
+		   psock->stats.rx_bytes,
+		   psock->stats.tx_msgs,
+		   psock->stats.tx_bytes,
+		   psock->sk->sk_receive_queue.qlen,
+		   atomic_read(&psock->sk->sk_rmem_alloc),
+		   psock->sk->sk_write_queue.qlen,
+		   atomic_read(&psock->sk->sk_wmem_alloc));
+
+	if (psock->done)
+		seq_puts(seq, "Done ");
+
+	if (psock->tx_stopped)
+		seq_puts(seq, "TxStop ");
+
+	if (psock->rx_stopped)
+		seq_puts(seq, "RxStop ");
+
+	if (psock->tx_kcm)
+		seq_printf(seq, "Rsvd-%d ", psock->tx_kcm->index);
+
+	if (psock->ready_rx_msg)
+		seq_puts(seq, "RdyRx ");
+
+	seq_puts(seq, "\n");
+}
+
+static void
+kcm_format_mux(struct kcm_mux *mux, loff_t idx, struct seq_file *seq)
+{
+	int i, len;
+	struct kcm_sock *kcm;
+	struct kcm_psock *psock;
+
+	/* mux information */
+	seq_printf(seq,
+		   "%-6s%-8s %-10llu %-16llu %-10llu %-16llu %-8s %-8s %-8s %-8s ",
+		   "mux", "",
+		   mux->stats.rx_msgs,
+		   mux->stats.rx_bytes,
+		   mux->stats.tx_msgs,
+		   mux->stats.tx_bytes,
+		   "-", "-", "-", "-");
+
+	seq_printf(seq, "KCMs: %d, Psocks %d\n",
+		   mux->kcm_socks_cnt, mux->psocks_cnt);
+
+	/* kcm sock information */
+	i = 0;
+	spin_lock_bh(&mux->lock);
+	list_for_each_entry(kcm, &mux->kcm_socks, kcm_sock_list) {
+		kcm_format_sock(kcm, seq, i, &len);
+		i++;
+	}
+	i = 0;
+	list_for_each_entry(psock, &mux->psocks, psock_list) {
+		kcm_format_psock(psock, seq, i, &len);
+		i++;
+	}
+	spin_unlock_bh(&mux->lock);
+}
+
+static int kcm_seq_show(struct seq_file *seq, void *v)
+{
+	struct kcm_proc_mux_state *mux_state;
+
+	mux_state = seq->private;
+	if (v == SEQ_START_TOKEN) {
+		mux_state->idx = 0;
+		kcm_format_mux_header(seq);
+	} else {
+		kcm_format_mux(v, mux_state->idx, seq);
+		mux_state->idx++;
+	}
+	return 0;
+}
+
+static const struct file_operations kcm_seq_fops = {
+	.owner		= THIS_MODULE,
+	.open		= kcm_seq_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+};
+
+static struct kcm_seq_muxinfo kcm_seq_muxinfo = {
+	.name		= "kcm",
+	.seq_fops	= &kcm_seq_fops,
+	.seq_ops	= {
+		.show	= kcm_seq_show,
+		.start	= kcm_seq_start,
+		.next	= kcm_seq_next,
+		.stop	= kcm_seq_stop,
+	}
+};
+
+static int kcm_proc_register(struct net *net, struct kcm_seq_muxinfo *muxinfo)
+{
+	struct proc_dir_entry *p;
+	int rc = 0;
+
+	p = proc_create_data(muxinfo->name, S_IRUGO, net->proc_net,
+			     muxinfo->seq_fops, muxinfo);
+	if (!p)
+		rc = -ENOMEM;
+	return rc;
+}
+EXPORT_SYMBOL(kcm_proc_register);
+
+static void kcm_proc_unregister(struct net *net,
+				struct kcm_seq_muxinfo *muxinfo)
+{
+	remove_proc_entry(muxinfo->name, net->proc_net);
+}
+EXPORT_SYMBOL(kcm_proc_unregister);
+
+static int kcm_stats_seq_show(struct seq_file *seq, void *v)
+{
+	struct kcm_psock_stats psock_stats;
+	struct kcm_mux_stats mux_stats;
+	struct kcm_mux *mux;
+	struct kcm_psock *psock;
+	struct net *net = seq->private;
+	struct kcm_net *knet = net_generic(net, kcm_net_id);
+
+	memset(&mux_stats, 0, sizeof(mux_stats));
+	memset(&psock_stats, 0, sizeof(psock_stats));
+
+	mutex_lock(&knet->mutex);
+
+	aggregate_mux_stats(&knet->aggregate_mux_stats, &mux_stats);
+	aggregate_psock_stats(&knet->aggregate_psock_stats,
+			      &psock_stats);
+
+	list_for_each_entry_rcu(mux, &knet->mux_list, kcm_mux_list) {
+		spin_lock_bh(&mux->lock);
+		aggregate_mux_stats(&mux->stats, &mux_stats);
+		aggregate_psock_stats(&mux->aggregate_psock_stats,
+				      &psock_stats);
+		list_for_each_entry(psock, &mux->psocks, psock_list)
+			aggregate_psock_stats(&psock->stats, &psock_stats);
+		spin_unlock_bh(&mux->lock);
+	}
+
+	mutex_unlock(&knet->mutex);
+
+	seq_printf(seq,
+		   "%-8s %-10s %-16s %-10s %-16s %-10s %-10s %-10s %-10s %-10s\n",
+		   "MUX",
+		   "RX-Msgs",
+		   "RX-Bytes",
+		   "TX-Msgs",
+		   "TX-Bytes",
+		   "TX-Retries",
+		   "Attach",
+		   "Unattach",
+		   "UnattchRsvd",
+		   "RX-RdyDrops");
+
+	seq_printf(seq,
+		   "%-8s %-10llu %-16llu %-10llu %-16llu %-10u %-10u %-10u %-10u %-10u\n",
+		   "",
+		   mux_stats.rx_msgs,
+		   mux_stats.rx_bytes,
+		   mux_stats.tx_msgs,
+		   mux_stats.tx_bytes,
+		   mux_stats.tx_retries,
+		   mux_stats.psock_attach,
+		   mux_stats.psock_unattach_rsvd,
+		   mux_stats.psock_unattach,
+		   mux_stats.rx_ready_drops);
+
+	seq_printf(seq,
+		   "%-8s %-10s %-16s %-10s %-16s %-10s %-10s %-10s %-10s %-10s %-10s %-10s\n",
+		   "Psock",
+		   "RX-Msgs",
+		   "RX-Bytes",
+		   "TX-Msgs",
+		   "TX-Bytes",
+		   "Reserved",
+		   "Unreserved",
+		   "RX-Aborts",
+		   "RX-MemFail",
+		   "RX-NeedMor",
+		   "RX-BadLen",
+		   "TX-Aborts");
+
+	seq_printf(seq,
+		   "%-8s %-10llu %-16llu %-10llu %-16llu %-10llu %-10llu %-10u %-10u %-10u %-10u %-10u\n",
+		   "",
+		   psock_stats.rx_msgs,
+		   psock_stats.rx_bytes,
+		   psock_stats.tx_msgs,
+		   psock_stats.tx_bytes,
+		   psock_stats.reserved,
+		   psock_stats.unreserved,
+		   psock_stats.rx_aborts,
+		   psock_stats.rx_mem_fail,
+		   psock_stats.rx_need_more_hdr,
+		   psock_stats.rx_bad_hdr_len,
+		   psock_stats.tx_aborts);
+
+	return 0;
+}
+
+static int kcm_stats_seq_open(struct inode *inode, struct file *file)
+{
+	return single_open_net(inode, file, kcm_stats_seq_show);
+}
+
+static const struct file_operations kcm_stats_seq_fops = {
+	.owner   = THIS_MODULE,
+	.open    = kcm_stats_seq_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = single_release_net,
+};
+
+static int kcm_proc_init_net(struct net *net)
+{
+	int err;
+
+	if (!proc_create("kcm_stats", S_IRUGO, net->proc_net,
+			 &kcm_stats_seq_fops)) {
+		err = -ENOMEM;
+		goto out_kcm_stats;
+	}
+
+	err = kcm_proc_register(net, &kcm_seq_muxinfo);
+	if (err)
+		goto out_kcm;
+
+	return 0;
+
+out_kcm:
+	remove_proc_entry("kcm_stats", net->proc_net);
+out_kcm_stats:
+	return err;
+}
+
+static void kcm_proc_exit_net(struct net *net)
+{
+	kcm_proc_unregister(net, &kcm_seq_muxinfo);
+	remove_proc_entry("kcm_stats", net->proc_net);
+}
+
+static struct pernet_operations kcm_net_ops = {
+	.init = kcm_proc_init_net,
+	.exit = kcm_proc_exit_net,
+};
+
+int __init kcm_proc_init(void)
+{
+	return register_pernet_subsys(&kcm_net_ops);
+}
+
+void __exit kcm_proc_exit(void)
+{
+	unregister_pernet_subsys(&kcm_net_ops);
+}
+
+#endif /* CONFIG_PROC_FS */