// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * INET         An implementation of the TCP/IP protocol suite for the LINUX
 *              operating system.  INET is implemented using the  BSD Socket
 *              interface as the means of communication with the user level.
 *
 *              This file implements the various access functions for the
 *              PROC file system.  This is very similar to the IPv4 version,
 *              except it reports the sockets in the INET6 address family.
 *
 * Authors:     David S. Miller (davem@caip.rutgers.edu)
 *              YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
 */
#include <linux/socket.h>
#include <linux/net.h>
#include <linux/ipv6.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/stddef.h>
#include <linux/export.h>
#include <net/net_namespace.h>
#include <net/ip.h>
#include <net/sock.h>
#include <net/tcp.h>
#include <net/udp.h>
#include <net/transp_v6.h>
#include <net/ipv6.h>

#define MAX4(a, b, c, d) \
        MAX_T(u32, MAX_T(u32, a, b), MAX_T(u32, c, d))
#define SNMP_MIB_MAX MAX4(UDP_MIB_MAX, TCP_MIB_MAX, \
                        IPSTATS_MIB_MAX, ICMP_MIB_MAX)

static int sockstat6_seq_show(struct seq_file *seq, void *v)
{
        struct net *net = seq->private;

        seq_printf(seq, "TCP6: inuse %d\n",
                       sock_prot_inuse_get(net, &tcpv6_prot));
        seq_printf(seq, "UDP6: inuse %d\n",
                       sock_prot_inuse_get(net, &udpv6_prot));
        seq_printf(seq, "UDPLITE6: inuse %d\n",
                        sock_prot_inuse_get(net, &udplitev6_prot));
        seq_printf(seq, "RAW6: inuse %d\n",
                       sock_prot_inuse_get(net, &rawv6_prot));
        seq_printf(seq, "FRAG6: inuse %u memory %lu\n",
                   atomic_read(&net->ipv6.fqdir->rhashtable.nelems),
                   frag_mem_limit(net->ipv6.fqdir));
        return 0;
}

static const struct snmp_mib snmp6_ipstats_list[] = {
/* ipv6 mib according to RFC 2465 */
        SNMP_MIB_ITEM("Ip6InReceives", IPSTATS_MIB_INPKTS),
        SNMP_MIB_ITEM("Ip6InHdrErrors", IPSTATS_MIB_INHDRERRORS),
        SNMP_MIB_ITEM("Ip6InTooBigErrors", IPSTATS_MIB_INTOOBIGERRORS),
        SNMP_MIB_ITEM("Ip6InNoRoutes", IPSTATS_MIB_INNOROUTES),
        SNMP_MIB_ITEM("Ip6InAddrErrors", IPSTATS_MIB_INADDRERRORS),
        SNMP_MIB_ITEM("Ip6InUnknownProtos", IPSTATS_MIB_INUNKNOWNPROTOS),
        SNMP_MIB_ITEM("Ip6InTruncatedPkts", IPSTATS_MIB_INTRUNCATEDPKTS),
        SNMP_MIB_ITEM("Ip6InDiscards", IPSTATS_MIB_INDISCARDS),
        SNMP_MIB_ITEM("Ip6InDelivers", IPSTATS_MIB_INDELIVERS),
        SNMP_MIB_ITEM("Ip6OutForwDatagrams", IPSTATS_MIB_OUTFORWDATAGRAMS),
        SNMP_MIB_ITEM("Ip6OutRequests", IPSTATS_MIB_OUTREQUESTS),
        SNMP_MIB_ITEM("Ip6OutDiscards", IPSTATS_MIB_OUTDISCARDS),
        SNMP_MIB_ITEM("Ip6OutNoRoutes", IPSTATS_MIB_OUTNOROUTES),
        SNMP_MIB_ITEM("Ip6ReasmTimeout", IPSTATS_MIB_REASMTIMEOUT),
        SNMP_MIB_ITEM("Ip6ReasmReqds", IPSTATS_MIB_REASMREQDS),
        SNMP_MIB_ITEM("Ip6ReasmOKs", IPSTATS_MIB_REASMOKS),
        SNMP_MIB_ITEM("Ip6ReasmFails", IPSTATS_MIB_REASMFAILS),
        SNMP_MIB_ITEM("Ip6FragOKs", IPSTATS_MIB_FRAGOKS),
        SNMP_MIB_ITEM("Ip6FragFails", IPSTATS_MIB_FRAGFAILS),
        SNMP_MIB_ITEM("Ip6FragCreates", IPSTATS_MIB_FRAGCREATES),
        SNMP_MIB_ITEM("Ip6InMcastPkts", IPSTATS_MIB_INMCASTPKTS),
        SNMP_MIB_ITEM("Ip6OutMcastPkts", IPSTATS_MIB_OUTMCASTPKTS),
        SNMP_MIB_ITEM("Ip6InOctets", IPSTATS_MIB_INOCTETS),
        SNMP_MIB_ITEM("Ip6OutOctets", IPSTATS_MIB_OUTOCTETS),
        SNMP_MIB_ITEM("Ip6InMcastOctets", IPSTATS_MIB_INMCASTOCTETS),
        SNMP_MIB_ITEM("Ip6OutMcastOctets", IPSTATS_MIB_OUTMCASTOCTETS),
        SNMP_MIB_ITEM("Ip6InBcastOctets", IPSTATS_MIB_INBCASTOCTETS),
        SNMP_MIB_ITEM("Ip6OutBcastOctets", IPSTATS_MIB_OUTBCASTOCTETS),
        /* IPSTATS_MIB_CSUMERRORS is not relevant in IPv6 (no checksum) */
        SNMP_MIB_ITEM("Ip6InNoECTPkts", IPSTATS_MIB_NOECTPKTS),
        SNMP_MIB_ITEM("Ip6InECT1Pkts", IPSTATS_MIB_ECT1PKTS),
        SNMP_MIB_ITEM("Ip6InECT0Pkts", IPSTATS_MIB_ECT0PKTS),
        SNMP_MIB_ITEM("Ip6InCEPkts", IPSTATS_MIB_CEPKTS),
        SNMP_MIB_ITEM("Ip6OutTransmits", IPSTATS_MIB_OUTPKTS),
};

static const struct snmp_mib snmp6_icmp6_list[] = {
/* icmpv6 mib according to RFC 2466 */
        SNMP_MIB_ITEM("Icmp6InMsgs", ICMP6_MIB_INMSGS),
        SNMP_MIB_ITEM("Icmp6InErrors", ICMP6_MIB_INERRORS),
        SNMP_MIB_ITEM("Icmp6OutMsgs", ICMP6_MIB_OUTMSGS),
        SNMP_MIB_ITEM("Icmp6OutErrors", ICMP6_MIB_OUTERRORS),
        SNMP_MIB_ITEM("Icmp6InCsumErrors", ICMP6_MIB_CSUMERRORS),
/* ICMP6_MIB_RATELIMITHOST needs to be last, see snmp6_dev_seq_show(). */
        SNMP_MIB_ITEM("Icmp6OutRateLimitHost", ICMP6_MIB_RATELIMITHOST),
};

static const struct snmp_mib snmp6_udp6_list[] = {
        SNMP_MIB_ITEM("Udp6InDatagrams", UDP_MIB_INDATAGRAMS),
        SNMP_MIB_ITEM("Udp6NoPorts", UDP_MIB_NOPORTS),
        SNMP_MIB_ITEM("Udp6InErrors", UDP_MIB_INERRORS),
        SNMP_MIB_ITEM("Udp6OutDatagrams", UDP_MIB_OUTDATAGRAMS),
        SNMP_MIB_ITEM("Udp6RcvbufErrors", UDP_MIB_RCVBUFERRORS),
        SNMP_MIB_ITEM("Udp6SndbufErrors", UDP_MIB_SNDBUFERRORS),
        SNMP_MIB_ITEM("Udp6InCsumErrors", UDP_MIB_CSUMERRORS),
        SNMP_MIB_ITEM("Udp6IgnoredMulti", UDP_MIB_IGNOREDMULTI),
        SNMP_MIB_ITEM("Udp6MemErrors", UDP_MIB_MEMERRORS),
};

static const struct snmp_mib snmp6_udplite6_list[] = {
        SNMP_MIB_ITEM("UdpLite6InDatagrams", UDP_MIB_INDATAGRAMS),
        SNMP_MIB_ITEM("UdpLite6NoPorts", UDP_MIB_NOPORTS),
        SNMP_MIB_ITEM("UdpLite6InErrors", UDP_MIB_INERRORS),
        SNMP_MIB_ITEM("UdpLite6OutDatagrams", UDP_MIB_OUTDATAGRAMS),
        SNMP_MIB_ITEM("UdpLite6RcvbufErrors", UDP_MIB_RCVBUFERRORS),
        SNMP_MIB_ITEM("UdpLite6SndbufErrors", UDP_MIB_SNDBUFERRORS),
        SNMP_MIB_ITEM("UdpLite6InCsumErrors", UDP_MIB_CSUMERRORS),
        SNMP_MIB_ITEM("UdpLite6MemErrors", UDP_MIB_MEMERRORS),
};

static void snmp6_seq_show_icmpv6msg(struct seq_file *seq, atomic_long_t *smib)
{
        char name[32];
        int i;

        /* print by name -- deprecated items */
        for (i = 0; i < ICMP6MSG_MIB_MAX; i++) {
                const char *p = NULL;
                int icmptype;

#define CASE(TYP, STR) case TYP: p = STR; break;

                icmptype = i & 0xff;
                switch (icmptype) {
/* RFC 4293 v6 ICMPMsgStatsTable; named items for RFC 2466 compatibility */
                CASE(ICMPV6_DEST_UNREACH,       "DestUnreachs")
                CASE(ICMPV6_PKT_TOOBIG,         "PktTooBigs")
                CASE(ICMPV6_TIME_EXCEED,        "TimeExcds")
                CASE(ICMPV6_PARAMPROB,          "ParmProblems")
                CASE(ICMPV6_ECHO_REQUEST,       "Echos")
                CASE(ICMPV6_ECHO_REPLY,         "EchoReplies")
                CASE(ICMPV6_MGM_QUERY,          "GroupMembQueries")
                CASE(ICMPV6_MGM_REPORT,         "GroupMembResponses")
                CASE(ICMPV6_MGM_REDUCTION,      "GroupMembReductions")
                CASE(ICMPV6_MLD2_REPORT,        "MLDv2Reports")
                CASE(NDISC_ROUTER_ADVERTISEMENT, "RouterAdvertisements")
                CASE(NDISC_ROUTER_SOLICITATION, "RouterSolicits")
                CASE(NDISC_NEIGHBOUR_ADVERTISEMENT, "NeighborAdvertisements")
                CASE(NDISC_NEIGHBOUR_SOLICITATION, "NeighborSolicits")
                CASE(NDISC_REDIRECT,            "Redirects")
                }
#undef CASE
                if (!p) /* don't print un-named types here */
                        continue;
                snprintf(name, sizeof(name), "Icmp6%s%s",
                        i & 0x100 ? "Out" : "In", p);
                seq_printf(seq, "%-32s\t%lu\n", name,
                           atomic_long_read(smib + i));
        }

        /* print by number (nonzero only) - ICMPMsgStat format */
        for (i = 0; i < ICMP6MSG_MIB_MAX; i++) {
                unsigned long val;

                val = atomic_long_read(smib + i);
                if (!val)
                        continue;
                snprintf(name, sizeof(name), "Icmp6%sType%u",
                        i & 0x100 ?  "Out" : "In", i & 0xff);
                seq_printf(seq, "%-32s\t%lu\n", name, val);
        }
}

/* can be called either with percpu mib (pcpumib != NULL),
 * or shared one (smib != NULL)
 */
static void snmp6_seq_show_item(struct seq_file *seq, void __percpu *pcpumib,
                                atomic_long_t *smib,
                                const struct snmp_mib *itemlist,
                                int cnt)
{
        unsigned long buff[SNMP_MIB_MAX];
        int i;

        if (pcpumib) {
                memset(buff, 0, sizeof(unsigned long) * cnt);

                snmp_get_cpu_field_batch_cnt(buff, itemlist, cnt, pcpumib);
                for (i = 0; i < cnt; i++)
                        seq_printf(seq, "%-32s\t%lu\n",
                                   itemlist[i].name, buff[i]);
        } else {
                for (i = 0; i < cnt; i++)
                        seq_printf(seq, "%-32s\t%lu\n", itemlist[i].name,
                                   atomic_long_read(smib + itemlist[i].entry));
        }
}

static void snmp6_seq_show_item64(struct seq_file *seq, void __percpu *mib,
                                  const struct snmp_mib *itemlist,
                                  int cnt, size_t syncpoff)
{
        u64 buff64[SNMP_MIB_MAX];
        int i;

        memset(buff64, 0, sizeof(u64) * cnt);

        snmp_get_cpu_field64_batch_cnt(buff64, itemlist, cnt, mib, syncpoff);
        for (i = 0; i < cnt; i++)
                seq_printf(seq, "%-32s\t%llu\n", itemlist[i].name, buff64[i]);
}

static int snmp6_seq_show(struct seq_file *seq, void *v)
{
        struct net *net = (struct net *)seq->private;

        snmp6_seq_show_item64(seq, net->mib.ipv6_statistics,
                              snmp6_ipstats_list,
                              ARRAY_SIZE(snmp6_ipstats_list),
                              offsetof(struct ipstats_mib, syncp));
        snmp6_seq_show_item(seq, net->mib.icmpv6_statistics,
                            NULL, snmp6_icmp6_list,
                            ARRAY_SIZE(snmp6_icmp6_list));
        snmp6_seq_show_icmpv6msg(seq, net->mib.icmpv6msg_statistics->mibs);
        snmp6_seq_show_item(seq, net->mib.udp_stats_in6,
                            NULL, snmp6_udp6_list,
                            ARRAY_SIZE(snmp6_udp6_list));
        snmp6_seq_show_item(seq, net->mib.udplite_stats_in6,
                            NULL, snmp6_udplite6_list,
                            ARRAY_SIZE(snmp6_udplite6_list));
        return 0;
}

static int snmp6_dev_seq_show(struct seq_file *seq, void *v)
{
        struct inet6_dev *idev = (struct inet6_dev *)seq->private;

        seq_printf(seq, "%-32s\t%u\n", "ifIndex", idev->dev->ifindex);
        snmp6_seq_show_item64(seq, idev->stats.ipv6,
                              snmp6_ipstats_list,
                              ARRAY_SIZE(snmp6_ipstats_list),
                              offsetof(struct ipstats_mib, syncp));

        /* Per idev icmp stats do not have ICMP6_MIB_RATELIMITHOST */
        snmp6_seq_show_item(seq, NULL, idev->stats.icmpv6dev->mibs,
                            snmp6_icmp6_list, ARRAY_SIZE(snmp6_icmp6_list) - 1);

        snmp6_seq_show_icmpv6msg(seq, idev->stats.icmpv6msgdev->mibs);
        return 0;
}

int snmp6_register_dev(struct inet6_dev *idev)
{
        struct proc_dir_entry *p;
        struct net *net;

        if (!idev || !idev->dev)
                return -EINVAL;

        net = dev_net(idev->dev);
        if (!net->mib.proc_net_devsnmp6)
                return -ENOENT;

        p = proc_create_single_data(idev->dev->name, 0444,
                        net->mib.proc_net_devsnmp6, snmp6_dev_seq_show, idev);
        if (!p)
                return -ENOMEM;

        idev->stats.proc_dir_entry = p;
        return 0;
}

int snmp6_unregister_dev(struct inet6_dev *idev)
{
        struct net *net = dev_net(idev->dev);
        if (!net->mib.proc_net_devsnmp6)
                return -ENOENT;
        if (!idev->stats.proc_dir_entry)
                return -EINVAL;
        proc_remove(idev->stats.proc_dir_entry);
        idev->stats.proc_dir_entry = NULL;
        return 0;
}

static int __net_init ipv6_proc_init_net(struct net *net)
{
        if (!proc_create_net_single("sockstat6", 0444, net->proc_net,
                        sockstat6_seq_show, NULL))
                return -ENOMEM;

        if (!proc_create_net_single("snmp6", 0444, net->proc_net,
                        snmp6_seq_show, NULL))
                goto proc_snmp6_fail;

        net->mib.proc_net_devsnmp6 = proc_mkdir("dev_snmp6", net->proc_net);
        if (!net->mib.proc_net_devsnmp6)
                goto proc_dev_snmp6_fail;
        return 0;

proc_dev_snmp6_fail:
        remove_proc_entry("snmp6", net->proc_net);
proc_snmp6_fail:
        remove_proc_entry("sockstat6", net->proc_net);
        return -ENOMEM;
}

static void __net_exit ipv6_proc_exit_net(struct net *net)
{
        remove_proc_entry("sockstat6", net->proc_net);
        remove_proc_entry("dev_snmp6", net->proc_net);
        remove_proc_entry("snmp6", net->proc_net);
}

static struct pernet_operations ipv6_proc_ops = {
        .init = ipv6_proc_init_net,
        .exit = ipv6_proc_exit_net,
};

int __init ipv6_misc_proc_init(void)
{
        return register_pernet_subsys(&ipv6_proc_ops);
}

void ipv6_misc_proc_exit(void)
{
        unregister_pernet_subsys(&ipv6_proc_ops);
}