root/net/appletalk/atalk_proc.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 *      atalk_proc.c - proc support for Appletalk
 *
 *      Copyright(c) Arnaldo Carvalho de Melo <acme@conectiva.com.br>
 */

#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <linux/atalk.h>
#include <linux/export.h>


static __inline__ struct atalk_iface *atalk_get_interface_idx(loff_t pos)
{
        struct atalk_iface *i;

        for (i = atalk_interfaces; pos && i; i = i->next)
                --pos;

        return i;
}

static void *atalk_seq_interface_start(struct seq_file *seq, loff_t *pos)
        __acquires(atalk_interfaces_lock)
{
        loff_t l = *pos;

        read_lock_bh(&atalk_interfaces_lock);
        return l ? atalk_get_interface_idx(--l) : SEQ_START_TOKEN;
}

static void *atalk_seq_interface_next(struct seq_file *seq, void *v, loff_t *pos)
{
        struct atalk_iface *i;

        ++*pos;
        if (v == SEQ_START_TOKEN) {
                i = NULL;
                if (atalk_interfaces)
                        i = atalk_interfaces;
                goto out;
        }
        i = v;
        i = i->next;
out:
        return i;
}

static void atalk_seq_interface_stop(struct seq_file *seq, void *v)
        __releases(atalk_interfaces_lock)
{
        read_unlock_bh(&atalk_interfaces_lock);
}

static int atalk_seq_interface_show(struct seq_file *seq, void *v)
{
        struct atalk_iface *iface;

        if (v == SEQ_START_TOKEN) {
                seq_puts(seq, "Interface        Address   Networks  "
                              "Status\n");
                goto out;
        }

        iface = v;
        seq_printf(seq, "%-16s %04X:%02X  %04X-%04X  %d\n",
                   iface->dev->name, ntohs(iface->address.s_net),
                   iface->address.s_node, ntohs(iface->nets.nr_firstnet),
                   ntohs(iface->nets.nr_lastnet), iface->status);
out:
        return 0;
}

static __inline__ struct atalk_route *atalk_get_route_idx(loff_t pos)
{
        struct atalk_route *r;

        for (r = atalk_routes; pos && r; r = r->next)
                --pos;

        return r;
}

static void *atalk_seq_route_start(struct seq_file *seq, loff_t *pos)
        __acquires(atalk_routes_lock)
{
        loff_t l = *pos;

        read_lock_bh(&atalk_routes_lock);
        return l ? atalk_get_route_idx(--l) : SEQ_START_TOKEN;
}

static void *atalk_seq_route_next(struct seq_file *seq, void *v, loff_t *pos)
{
        struct atalk_route *r;

        ++*pos;
        if (v == SEQ_START_TOKEN) {
                r = NULL;
                if (atalk_routes)
                        r = atalk_routes;
                goto out;
        }
        r = v;
        r = r->next;
out:
        return r;
}

static void atalk_seq_route_stop(struct seq_file *seq, void *v)
        __releases(atalk_routes_lock)
{
        read_unlock_bh(&atalk_routes_lock);
}

static int atalk_seq_route_show(struct seq_file *seq, void *v)
{
        struct atalk_route *rt;

        if (v == SEQ_START_TOKEN) {
                seq_puts(seq, "Target        Router  Flags Dev\n");
                goto out;
        }

        if (atrtr_default.dev) {
                rt = &atrtr_default;
                seq_printf(seq, "Default     %04X:%02X  %-4d  %s\n",
                               ntohs(rt->gateway.s_net), rt->gateway.s_node,
                               rt->flags, rt->dev->name);
        }

        rt = v;
        seq_printf(seq, "%04X:%02X     %04X:%02X  %-4d  %s\n",
                   ntohs(rt->target.s_net), rt->target.s_node,
                   ntohs(rt->gateway.s_net), rt->gateway.s_node,
                   rt->flags, rt->dev->name);
out:
        return 0;
}

static void *atalk_seq_socket_start(struct seq_file *seq, loff_t *pos)
        __acquires(atalk_sockets_lock)
{
        read_lock_bh(&atalk_sockets_lock);
        return seq_hlist_start_head(&atalk_sockets, *pos);
}

static void *atalk_seq_socket_next(struct seq_file *seq, void *v, loff_t *pos)
{
        return seq_hlist_next(v, &atalk_sockets, pos);
}

static void atalk_seq_socket_stop(struct seq_file *seq, void *v)
        __releases(atalk_sockets_lock)
{
        read_unlock_bh(&atalk_sockets_lock);
}

static int atalk_seq_socket_show(struct seq_file *seq, void *v)
{
        struct sock *s;
        struct atalk_sock *at;

        if (v == SEQ_START_TOKEN) {
                seq_printf(seq, "Type Local_addr  Remote_addr Tx_queue "
                                "Rx_queue St UID\n");
                goto out;
        }

        s = sk_entry(v);
        at = at_sk(s);

        seq_printf(seq, "%02X   %04X:%02X:%02X  %04X:%02X:%02X  %08X:%08X "
                        "%02X %u\n",
                   s->sk_type, ntohs(at->src_net), at->src_node, at->src_port,
                   ntohs(at->dest_net), at->dest_node, at->dest_port,
                   sk_wmem_alloc_get(s),
                   sk_rmem_alloc_get(s),
                   s->sk_state,
                   from_kuid_munged(seq_user_ns(seq), sk_uid(s)));
out:
        return 0;
}

static const struct seq_operations atalk_seq_interface_ops = {
        .start  = atalk_seq_interface_start,
        .next   = atalk_seq_interface_next,
        .stop   = atalk_seq_interface_stop,
        .show   = atalk_seq_interface_show,
};

static const struct seq_operations atalk_seq_route_ops = {
        .start  = atalk_seq_route_start,
        .next   = atalk_seq_route_next,
        .stop   = atalk_seq_route_stop,
        .show   = atalk_seq_route_show,
};

static const struct seq_operations atalk_seq_socket_ops = {
        .start  = atalk_seq_socket_start,
        .next   = atalk_seq_socket_next,
        .stop   = atalk_seq_socket_stop,
        .show   = atalk_seq_socket_show,
};

int __init atalk_proc_init(void)
{
        if (!proc_mkdir("atalk", init_net.proc_net))
                return -ENOMEM;

        if (!proc_create_seq("atalk/interface", 0444, init_net.proc_net,
                            &atalk_seq_interface_ops))
                goto out;

        if (!proc_create_seq("atalk/route", 0444, init_net.proc_net,
                            &atalk_seq_route_ops))
                goto out;

        if (!proc_create_seq("atalk/socket", 0444, init_net.proc_net,
                            &atalk_seq_socket_ops))
                goto out;

        if (!proc_create_seq_private("atalk/arp", 0444, init_net.proc_net,
                                     &aarp_seq_ops,
                                     sizeof(struct aarp_iter_state), NULL))
                goto out;

        return 0;

out:
        remove_proc_subtree("atalk", init_net.proc_net);
        return -ENOMEM;
}

void atalk_proc_exit(void)
{
        remove_proc_subtree("atalk", init_net.proc_net);
}