// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * netdebug.c
 *
 * debug functionality for o2net
 *
 * Copyright (C) 2005, 2008 Oracle.  All rights reserved.
 */

#ifdef CONFIG_DEBUG_FS

#include <linux/module.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/kref.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>

#include <linux/uaccess.h>

#include "tcp.h"
#include "nodemanager.h"
#define MLOG_MASK_PREFIX ML_TCP
#include "masklog.h"

#include "tcp_internal.h"

#define O2NET_DEBUG_DIR         "o2net"
#define SC_DEBUG_NAME           "sock_containers"
#define NST_DEBUG_NAME          "send_tracking"
#define STATS_DEBUG_NAME        "stats"
#define NODES_DEBUG_NAME        "connected_nodes"

#define SHOW_SOCK_CONTAINERS    0
#define SHOW_SOCK_STATS         1

static struct dentry *o2net_dentry;

static DEFINE_SPINLOCK(o2net_debug_lock);

static LIST_HEAD(sock_containers);
static LIST_HEAD(send_tracking);

void o2net_debug_add_nst(struct o2net_send_tracking *nst)
{
        spin_lock_bh(&o2net_debug_lock);
        list_add(&nst->st_net_debug_item, &send_tracking);
        spin_unlock_bh(&o2net_debug_lock);
}

void o2net_debug_del_nst(struct o2net_send_tracking *nst)
{
        spin_lock_bh(&o2net_debug_lock);
        if (!list_empty(&nst->st_net_debug_item))
                list_del_init(&nst->st_net_debug_item);
        spin_unlock_bh(&o2net_debug_lock);
}

static struct o2net_send_tracking
                        *next_nst(struct o2net_send_tracking *nst_start)
{
        struct o2net_send_tracking *nst, *ret = NULL;

        assert_spin_locked(&o2net_debug_lock);

        list_for_each_entry(nst, &nst_start->st_net_debug_item,
                            st_net_debug_item) {
                /* discover the head of the list */
                if (&nst->st_net_debug_item == &send_tracking)
                        break;

                /* use st_task to detect real nsts in the list */
                if (nst->st_task != NULL) {
                        ret = nst;
                        break;
                }
        }

        return ret;
}

static void *nst_seq_start(struct seq_file *seq, loff_t *pos)
{
        struct o2net_send_tracking *nst, *dummy_nst = seq->private;

        spin_lock_bh(&o2net_debug_lock);
        nst = next_nst(dummy_nst);
        spin_unlock_bh(&o2net_debug_lock);

        return nst;
}

static void *nst_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
        struct o2net_send_tracking *nst, *dummy_nst = seq->private;

        spin_lock_bh(&o2net_debug_lock);
        nst = next_nst(dummy_nst);
        list_del_init(&dummy_nst->st_net_debug_item);
        if (nst)
                list_add(&dummy_nst->st_net_debug_item,
                         &nst->st_net_debug_item);
        spin_unlock_bh(&o2net_debug_lock);

        return nst; /* unused, just needs to be null when done */
}

static int nst_seq_show(struct seq_file *seq, void *v)
{
        struct o2net_send_tracking *nst, *dummy_nst = seq->private;
        ktime_t now;
        s64 sock, send, status;

        spin_lock_bh(&o2net_debug_lock);
        nst = next_nst(dummy_nst);
        if (!nst)
                goto out;

        now = ktime_get();
        sock = ktime_to_us(ktime_sub(now, nst->st_sock_time));
        send = ktime_to_us(ktime_sub(now, nst->st_send_time));
        status = ktime_to_us(ktime_sub(now, nst->st_status_time));

        /* get_task_comm isn't exported.  oh well. */
        seq_printf(seq, "%p:\n"
                   "  pid:          %lu\n"
                   "  tgid:         %lu\n"
                   "  process name: %s\n"
                   "  node:         %u\n"
                   "  sc:           %p\n"
                   "  message id:   %d\n"
                   "  message type: %u\n"
                   "  message key:  0x%08x\n"
                   "  sock acquiry: %lld usecs ago\n"
                   "  send start:   %lld usecs ago\n"
                   "  wait start:   %lld usecs ago\n",
                   nst, (unsigned long)task_pid_nr(nst->st_task),
                   (unsigned long)nst->st_task->tgid,
                   nst->st_task->comm, nst->st_node,
                   nst->st_sc, nst->st_id, nst->st_msg_type,
                   nst->st_msg_key,
                   (long long)sock,
                   (long long)send,
                   (long long)status);

out:
        spin_unlock_bh(&o2net_debug_lock);

        return 0;
}

static void nst_seq_stop(struct seq_file *seq, void *v)
{
}

static const struct seq_operations nst_seq_ops = {
        .start = nst_seq_start,
        .next = nst_seq_next,
        .stop = nst_seq_stop,
        .show = nst_seq_show,
};

static int nst_fop_open(struct inode *inode, struct file *file)
{
        struct o2net_send_tracking *dummy_nst;

        dummy_nst = __seq_open_private(file, &nst_seq_ops, sizeof(*dummy_nst));
        if (!dummy_nst)
                return -ENOMEM;
        o2net_debug_add_nst(dummy_nst);

        return 0;
}

static int nst_fop_release(struct inode *inode, struct file *file)
{
        struct seq_file *seq = file->private_data;
        struct o2net_send_tracking *dummy_nst = seq->private;

        o2net_debug_del_nst(dummy_nst);
        return seq_release_private(inode, file);
}

static const struct file_operations nst_seq_fops = {
        .open = nst_fop_open,
        .read = seq_read,
        .llseek = seq_lseek,
        .release = nst_fop_release,
};

void o2net_debug_add_sc(struct o2net_sock_container *sc)
{
        spin_lock_bh(&o2net_debug_lock);
        list_add(&sc->sc_net_debug_item, &sock_containers);
        spin_unlock_bh(&o2net_debug_lock);
}

void o2net_debug_del_sc(struct o2net_sock_container *sc)
{
        spin_lock_bh(&o2net_debug_lock);
        list_del_init(&sc->sc_net_debug_item);
        spin_unlock_bh(&o2net_debug_lock);
}

struct o2net_sock_debug {
        int dbg_ctxt;
        struct o2net_sock_container *dbg_sock;
};

static struct o2net_sock_container
                        *next_sc(struct o2net_sock_container *sc_start)
{
        struct o2net_sock_container *sc, *ret = NULL;

        assert_spin_locked(&o2net_debug_lock);

        list_for_each_entry(sc, &sc_start->sc_net_debug_item,
                            sc_net_debug_item) {
                /* discover the head of the list miscast as a sc */
                if (&sc->sc_net_debug_item == &sock_containers)
                        break;

                /* use sc_page to detect real scs in the list */
                if (sc->sc_page != NULL) {
                        ret = sc;
                        break;
                }
        }

        return ret;
}

static void *sc_seq_start(struct seq_file *seq, loff_t *pos)
{
        struct o2net_sock_debug *sd = seq->private;
        struct o2net_sock_container *sc, *dummy_sc = sd->dbg_sock;

        spin_lock_bh(&o2net_debug_lock);
        sc = next_sc(dummy_sc);
        spin_unlock_bh(&o2net_debug_lock);

        return sc;
}

static void *sc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
        struct o2net_sock_debug *sd = seq->private;
        struct o2net_sock_container *sc, *dummy_sc = sd->dbg_sock;

        spin_lock_bh(&o2net_debug_lock);
        sc = next_sc(dummy_sc);
        list_del_init(&dummy_sc->sc_net_debug_item);
        if (sc)
                list_add(&dummy_sc->sc_net_debug_item, &sc->sc_net_debug_item);
        spin_unlock_bh(&o2net_debug_lock);

        return sc; /* unused, just needs to be null when done */
}

#ifdef CONFIG_OCFS2_FS_STATS
# define sc_send_count(_s)              ((_s)->sc_send_count)
# define sc_recv_count(_s)              ((_s)->sc_recv_count)
# define sc_tv_acquiry_total_ns(_s)     (ktime_to_ns((_s)->sc_tv_acquiry_total))
# define sc_tv_send_total_ns(_s)        (ktime_to_ns((_s)->sc_tv_send_total))
# define sc_tv_status_total_ns(_s)      (ktime_to_ns((_s)->sc_tv_status_total))
# define sc_tv_process_total_ns(_s)     (ktime_to_ns((_s)->sc_tv_process_total))
#else
# define sc_send_count(_s)              (0U)
# define sc_recv_count(_s)              (0U)
# define sc_tv_acquiry_total_ns(_s)     (0LL)
# define sc_tv_send_total_ns(_s)        (0LL)
# define sc_tv_status_total_ns(_s)      (0LL)
# define sc_tv_process_total_ns(_s)     (0LL)
#endif

/* So that debugfs.ocfs2 can determine which format is being used */
#define O2NET_STATS_STR_VERSION         1
static void sc_show_sock_stats(struct seq_file *seq,
                               struct o2net_sock_container *sc)
{
        if (!sc)
                return;

        seq_printf(seq, "%d,%u,%lu,%lld,%lld,%lld,%lu,%lld\n", O2NET_STATS_STR_VERSION,
                   sc->sc_node->nd_num, (unsigned long)sc_send_count(sc),
                   (long long)sc_tv_acquiry_total_ns(sc),
                   (long long)sc_tv_send_total_ns(sc),
                   (long long)sc_tv_status_total_ns(sc),
                   (unsigned long)sc_recv_count(sc),
                   (long long)sc_tv_process_total_ns(sc));
}

static void sc_show_sock_container(struct seq_file *seq,
                                   struct o2net_sock_container *sc)
{
        struct inet_sock *inet = NULL;
        __be32 saddr = 0, daddr = 0;
        __be16 sport = 0, dport = 0;

        if (!sc)
                return;

        if (sc->sc_sock) {
                inet = inet_sk(sc->sc_sock->sk);
                /* the stack's structs aren't sparse endian clean */
                saddr = (__force __be32)inet->inet_saddr;
                daddr = (__force __be32)inet->inet_daddr;
                sport = (__force __be16)inet->inet_sport;
                dport = (__force __be16)inet->inet_dport;
        }

        /* XXX sigh, inet-> doesn't have sparse annotation so any
         * use of it here generates a warning with -Wbitwise */
        seq_printf(seq, "%p:\n"
                   "  krefs:           %d\n"
                   "  sock:            %pI4:%u -> "
                                      "%pI4:%u\n"
                   "  remote node:     %s\n"
                   "  page off:        %zu\n"
                   "  handshake ok:    %u\n"
                   "  timer:           %lld usecs\n"
                   "  data ready:      %lld usecs\n"
                   "  advance start:   %lld usecs\n"
                   "  advance stop:    %lld usecs\n"
                   "  func start:      %lld usecs\n"
                   "  func stop:       %lld usecs\n"
                   "  func key:        0x%08x\n"
                   "  func type:       %u\n",
                   sc,
                   kref_read(&sc->sc_kref),
                   &saddr, inet ? ntohs(sport) : 0,
                   &daddr, inet ? ntohs(dport) : 0,
                   sc->sc_node->nd_name,
                   sc->sc_page_off,
                   sc->sc_handshake_ok,
                   (long long)ktime_to_us(sc->sc_tv_timer),
                   (long long)ktime_to_us(sc->sc_tv_data_ready),
                   (long long)ktime_to_us(sc->sc_tv_advance_start),
                   (long long)ktime_to_us(sc->sc_tv_advance_stop),
                   (long long)ktime_to_us(sc->sc_tv_func_start),
                   (long long)ktime_to_us(sc->sc_tv_func_stop),
                   sc->sc_msg_key,
                   sc->sc_msg_type);
}

static int sc_seq_show(struct seq_file *seq, void *v)
{
        struct o2net_sock_debug *sd = seq->private;
        struct o2net_sock_container *sc, *dummy_sc = sd->dbg_sock;

        spin_lock_bh(&o2net_debug_lock);
        sc = next_sc(dummy_sc);

        if (sc) {
                if (sd->dbg_ctxt == SHOW_SOCK_CONTAINERS)
                        sc_show_sock_container(seq, sc);
                else
                        sc_show_sock_stats(seq, sc);
        }

        spin_unlock_bh(&o2net_debug_lock);

        return 0;
}

static void sc_seq_stop(struct seq_file *seq, void *v)
{
}

static const struct seq_operations sc_seq_ops = {
        .start = sc_seq_start,
        .next = sc_seq_next,
        .stop = sc_seq_stop,
        .show = sc_seq_show,
};

static int sc_common_open(struct file *file, int ctxt)
{
        struct o2net_sock_debug *sd;
        struct o2net_sock_container *dummy_sc;

        dummy_sc = kzalloc_obj(*dummy_sc);
        if (!dummy_sc)
                return -ENOMEM;

        sd = __seq_open_private(file, &sc_seq_ops, sizeof(*sd));
        if (!sd) {
                kfree(dummy_sc);
                return -ENOMEM;
        }

        sd->dbg_ctxt = ctxt;
        sd->dbg_sock = dummy_sc;

        o2net_debug_add_sc(dummy_sc);

        return 0;
}

static int sc_fop_release(struct inode *inode, struct file *file)
{
        struct seq_file *seq = file->private_data;
        struct o2net_sock_debug *sd = seq->private;
        struct o2net_sock_container *dummy_sc = sd->dbg_sock;

        o2net_debug_del_sc(dummy_sc);
        kfree(dummy_sc);
        return seq_release_private(inode, file);
}

static int stats_fop_open(struct inode *inode, struct file *file)
{
        return sc_common_open(file, SHOW_SOCK_STATS);
}

static const struct file_operations stats_seq_fops = {
        .open = stats_fop_open,
        .read = seq_read,
        .llseek = seq_lseek,
        .release = sc_fop_release,
};

static int sc_fop_open(struct inode *inode, struct file *file)
{
        return sc_common_open(file, SHOW_SOCK_CONTAINERS);
}

static const struct file_operations sc_seq_fops = {
        .open = sc_fop_open,
        .read = seq_read,
        .llseek = seq_lseek,
        .release = sc_fop_release,
};

static int o2net_fill_bitmap(char *buf, int len)
{
        unsigned long map[BITS_TO_LONGS(O2NM_MAX_NODES)];
        int i = -1, out = 0;

        o2net_fill_node_map(map, O2NM_MAX_NODES);

        while ((i = find_next_bit(map, O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES)
                out += scnprintf(buf + out, PAGE_SIZE - out, "%d ", i);
        out += scnprintf(buf + out, PAGE_SIZE - out, "\n");

        return out;
}

static int nodes_fop_open(struct inode *inode, struct file *file)
{
        char *buf;

        buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        i_size_write(inode, o2net_fill_bitmap(buf, PAGE_SIZE));

        file->private_data = buf;

        return 0;
}

static int o2net_debug_release(struct inode *inode, struct file *file)
{
        kfree(file->private_data);
        return 0;
}

static ssize_t o2net_debug_read(struct file *file, char __user *buf,
                                size_t nbytes, loff_t *ppos)
{
        return simple_read_from_buffer(buf, nbytes, ppos, file->private_data,
                                       i_size_read(file->f_mapping->host));
}

static const struct file_operations nodes_fops = {
        .open           = nodes_fop_open,
        .release        = o2net_debug_release,
        .read           = o2net_debug_read,
        .llseek         = generic_file_llseek,
};

void o2net_debugfs_exit(void)
{
        debugfs_remove_recursive(o2net_dentry);
}

void o2net_debugfs_init(void)
{
        umode_t mode = S_IFREG|S_IRUSR;

        o2net_dentry = debugfs_create_dir(O2NET_DEBUG_DIR, NULL);

        debugfs_create_file(NST_DEBUG_NAME, mode, o2net_dentry, NULL,
                            &nst_seq_fops);
        debugfs_create_file(SC_DEBUG_NAME, mode, o2net_dentry, NULL,
                            &sc_seq_fops);
        debugfs_create_file(STATS_DEBUG_NAME, mode, o2net_dentry, NULL,
                            &stats_seq_fops);
        debugfs_create_file(NODES_DEBUG_NAME, mode, o2net_dentry, NULL,
                            &nodes_fops);
}

#endif  /* CONFIG_DEBUG_FS */