net-sysfs: try not to restart the syscall if it will fail eventually

[mirror_ubuntu-jammy-kernel.git] / net / ipv4 / proc.c

// 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.  It is mainly used for debugging and
 *              statistics.
 *
 * Authors:     Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *              Gerald J. Heim, <heim@peanuts.informatik.uni-tuebingen.de>
 *              Fred Baumgarten, <dc6iq@insu1.etec.uni-karlsruhe.de>
 *              Erik Schoenfelder, <schoenfr@ibr.cs.tu-bs.de>
 *
 * Fixes:
 *              Alan Cox        :       UDP sockets show the rxqueue/txqueue
 *                                      using hint flag for the netinfo.
 *      Pauline Middelink       :       identd support
 *              Alan Cox        :       Make /proc safer.
 *      Erik Schoenfelder       :       /proc/net/snmp
 *              Alan Cox        :       Handle dead sockets properly.
 *      Gerhard Koerting        :       Show both timers
 *              Alan Cox        :       Allow inode to be NULL (kernel socket)
 *      Andi Kleen              :       Add support for open_requests and
 *                                      split functions for more readibility.
 *      Andi Kleen              :       Add support for /proc/net/netstat
 *      Arnaldo C. Melo         :       Convert to seq_file
 */
#include <linux/types.h>
#include <net/net_namespace.h>
#include <net/icmp.h>
#include <net/protocol.h>
#include <net/tcp.h>
#include <net/mptcp.h>
#include <net/udp.h>
#include <net/udplite.h>
#include <linux/bottom_half.h>
#include <linux/inetdevice.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/export.h>
#include <net/sock.h>
#include <net/raw.h>

#define TCPUDP_MIB_MAX max_t(u32, UDP_MIB_MAX, TCP_MIB_MAX)

/*
 *      Report socket allocation statistics [mea@utu.fi]
 */
static int sockstat_seq_show(struct seq_file *seq, void *v)
{
        struct net *net = seq->private;
        int orphans, sockets;

        orphans = percpu_counter_sum_positive(&tcp_orphan_count);
        sockets = proto_sockets_allocated_sum_positive(&tcp_prot);

        socket_seq_show(seq);
        seq_printf(seq, "TCP: inuse %d orphan %d tw %d alloc %d mem %ld\n",
                   sock_prot_inuse_get(net, &tcp_prot), orphans,
                   atomic_read(&net->ipv4.tcp_death_row.tw_count), sockets,
                   proto_memory_allocated(&tcp_prot));
        seq_printf(seq, "UDP: inuse %d mem %ld\n",
                   sock_prot_inuse_get(net, &udp_prot),
                   proto_memory_allocated(&udp_prot));
        seq_printf(seq, "UDPLITE: inuse %d\n",
                   sock_prot_inuse_get(net, &udplite_prot));
        seq_printf(seq, "RAW: inuse %d\n",
                   sock_prot_inuse_get(net, &raw_prot));
        seq_printf(seq,  "FRAG: inuse %u memory %lu\n",
                   atomic_read(&net->ipv4.fqdir->rhashtable.nelems),
                   frag_mem_limit(net->ipv4.fqdir));
        return 0;
}

/* snmp items */
static const struct snmp_mib snmp4_ipstats_list[] = {
        SNMP_MIB_ITEM("InReceives", IPSTATS_MIB_INPKTS),
        SNMP_MIB_ITEM("InHdrErrors", IPSTATS_MIB_INHDRERRORS),
        SNMP_MIB_ITEM("InAddrErrors", IPSTATS_MIB_INADDRERRORS),
        SNMP_MIB_ITEM("ForwDatagrams", IPSTATS_MIB_OUTFORWDATAGRAMS),
        SNMP_MIB_ITEM("InUnknownProtos", IPSTATS_MIB_INUNKNOWNPROTOS),
        SNMP_MIB_ITEM("InDiscards", IPSTATS_MIB_INDISCARDS),
        SNMP_MIB_ITEM("InDelivers", IPSTATS_MIB_INDELIVERS),
        SNMP_MIB_ITEM("OutRequests", IPSTATS_MIB_OUTPKTS),
        SNMP_MIB_ITEM("OutDiscards", IPSTATS_MIB_OUTDISCARDS),
        SNMP_MIB_ITEM("OutNoRoutes", IPSTATS_MIB_OUTNOROUTES),
        SNMP_MIB_ITEM("ReasmTimeout", IPSTATS_MIB_REASMTIMEOUT),
        SNMP_MIB_ITEM("ReasmReqds", IPSTATS_MIB_REASMREQDS),
        SNMP_MIB_ITEM("ReasmOKs", IPSTATS_MIB_REASMOKS),
        SNMP_MIB_ITEM("ReasmFails", IPSTATS_MIB_REASMFAILS),
        SNMP_MIB_ITEM("FragOKs", IPSTATS_MIB_FRAGOKS),
        SNMP_MIB_ITEM("FragFails", IPSTATS_MIB_FRAGFAILS),
        SNMP_MIB_ITEM("FragCreates", IPSTATS_MIB_FRAGCREATES),
        SNMP_MIB_SENTINEL
};

/* Following items are displayed in /proc/net/netstat */
static const struct snmp_mib snmp4_ipextstats_list[] = {
        SNMP_MIB_ITEM("InNoRoutes", IPSTATS_MIB_INNOROUTES),
        SNMP_MIB_ITEM("InTruncatedPkts", IPSTATS_MIB_INTRUNCATEDPKTS),
        SNMP_MIB_ITEM("InMcastPkts", IPSTATS_MIB_INMCASTPKTS),
        SNMP_MIB_ITEM("OutMcastPkts", IPSTATS_MIB_OUTMCASTPKTS),
        SNMP_MIB_ITEM("InBcastPkts", IPSTATS_MIB_INBCASTPKTS),
        SNMP_MIB_ITEM("OutBcastPkts", IPSTATS_MIB_OUTBCASTPKTS),
        SNMP_MIB_ITEM("InOctets", IPSTATS_MIB_INOCTETS),
        SNMP_MIB_ITEM("OutOctets", IPSTATS_MIB_OUTOCTETS),
        SNMP_MIB_ITEM("InMcastOctets", IPSTATS_MIB_INMCASTOCTETS),
        SNMP_MIB_ITEM("OutMcastOctets", IPSTATS_MIB_OUTMCASTOCTETS),
        SNMP_MIB_ITEM("InBcastOctets", IPSTATS_MIB_INBCASTOCTETS),
        SNMP_MIB_ITEM("OutBcastOctets", IPSTATS_MIB_OUTBCASTOCTETS),
        /* Non RFC4293 fields */
        SNMP_MIB_ITEM("InCsumErrors", IPSTATS_MIB_CSUMERRORS),
        SNMP_MIB_ITEM("InNoECTPkts", IPSTATS_MIB_NOECTPKTS),
        SNMP_MIB_ITEM("InECT1Pkts", IPSTATS_MIB_ECT1PKTS),
        SNMP_MIB_ITEM("InECT0Pkts", IPSTATS_MIB_ECT0PKTS),
        SNMP_MIB_ITEM("InCEPkts", IPSTATS_MIB_CEPKTS),
        SNMP_MIB_ITEM("ReasmOverlaps", IPSTATS_MIB_REASM_OVERLAPS),
        SNMP_MIB_SENTINEL
};

static const struct {
        const char *name;
        int index;
} icmpmibmap[] = {
        { "DestUnreachs", ICMP_DEST_UNREACH },
        { "TimeExcds", ICMP_TIME_EXCEEDED },
        { "ParmProbs", ICMP_PARAMETERPROB },
        { "SrcQuenchs", ICMP_SOURCE_QUENCH },
        { "Redirects", ICMP_REDIRECT },
        { "Echos", ICMP_ECHO },
        { "EchoReps", ICMP_ECHOREPLY },
        { "Timestamps", ICMP_TIMESTAMP },
        { "TimestampReps", ICMP_TIMESTAMPREPLY },
        { "AddrMasks", ICMP_ADDRESS },
        { "AddrMaskReps", ICMP_ADDRESSREPLY },
        { NULL, 0 }
};


static const struct snmp_mib snmp4_tcp_list[] = {
        SNMP_MIB_ITEM("RtoAlgorithm", TCP_MIB_RTOALGORITHM),
        SNMP_MIB_ITEM("RtoMin", TCP_MIB_RTOMIN),
        SNMP_MIB_ITEM("RtoMax", TCP_MIB_RTOMAX),
        SNMP_MIB_ITEM("MaxConn", TCP_MIB_MAXCONN),
        SNMP_MIB_ITEM("ActiveOpens", TCP_MIB_ACTIVEOPENS),
        SNMP_MIB_ITEM("PassiveOpens", TCP_MIB_PASSIVEOPENS),
        SNMP_MIB_ITEM("AttemptFails", TCP_MIB_ATTEMPTFAILS),
        SNMP_MIB_ITEM("EstabResets", TCP_MIB_ESTABRESETS),
        SNMP_MIB_ITEM("CurrEstab", TCP_MIB_CURRESTAB),
        SNMP_MIB_ITEM("InSegs", TCP_MIB_INSEGS),
        SNMP_MIB_ITEM("OutSegs", TCP_MIB_OUTSEGS),
        SNMP_MIB_ITEM("RetransSegs", TCP_MIB_RETRANSSEGS),
        SNMP_MIB_ITEM("InErrs", TCP_MIB_INERRS),
        SNMP_MIB_ITEM("OutRsts", TCP_MIB_OUTRSTS),
        SNMP_MIB_ITEM("InCsumErrors", TCP_MIB_CSUMERRORS),
        SNMP_MIB_SENTINEL
};

static const struct snmp_mib snmp4_udp_list[] = {
        SNMP_MIB_ITEM("InDatagrams", UDP_MIB_INDATAGRAMS),
        SNMP_MIB_ITEM("NoPorts", UDP_MIB_NOPORTS),
        SNMP_MIB_ITEM("InErrors", UDP_MIB_INERRORS),
        SNMP_MIB_ITEM("OutDatagrams", UDP_MIB_OUTDATAGRAMS),
        SNMP_MIB_ITEM("RcvbufErrors", UDP_MIB_RCVBUFERRORS),
        SNMP_MIB_ITEM("SndbufErrors", UDP_MIB_SNDBUFERRORS),
        SNMP_MIB_ITEM("InCsumErrors", UDP_MIB_CSUMERRORS),
        SNMP_MIB_ITEM("IgnoredMulti", UDP_MIB_IGNOREDMULTI),
        SNMP_MIB_ITEM("MemErrors", UDP_MIB_MEMERRORS),
        SNMP_MIB_SENTINEL
};

static const struct snmp_mib snmp4_net_list[] = {
        SNMP_MIB_ITEM("SyncookiesSent", LINUX_MIB_SYNCOOKIESSENT),
        SNMP_MIB_ITEM("SyncookiesRecv", LINUX_MIB_SYNCOOKIESRECV),
        SNMP_MIB_ITEM("SyncookiesFailed", LINUX_MIB_SYNCOOKIESFAILED),
        SNMP_MIB_ITEM("EmbryonicRsts", LINUX_MIB_EMBRYONICRSTS),
        SNMP_MIB_ITEM("PruneCalled", LINUX_MIB_PRUNECALLED),
        SNMP_MIB_ITEM("RcvPruned", LINUX_MIB_RCVPRUNED),
        SNMP_MIB_ITEM("OfoPruned", LINUX_MIB_OFOPRUNED),
        SNMP_MIB_ITEM("OutOfWindowIcmps", LINUX_MIB_OUTOFWINDOWICMPS),
        SNMP_MIB_ITEM("LockDroppedIcmps", LINUX_MIB_LOCKDROPPEDICMPS),
        SNMP_MIB_ITEM("ArpFilter", LINUX_MIB_ARPFILTER),
        SNMP_MIB_ITEM("TW", LINUX_MIB_TIMEWAITED),
        SNMP_MIB_ITEM("TWRecycled", LINUX_MIB_TIMEWAITRECYCLED),
        SNMP_MIB_ITEM("TWKilled", LINUX_MIB_TIMEWAITKILLED),
        SNMP_MIB_ITEM("PAWSActive", LINUX_MIB_PAWSACTIVEREJECTED),
        SNMP_MIB_ITEM("PAWSEstab", LINUX_MIB_PAWSESTABREJECTED),
        SNMP_MIB_ITEM("DelayedACKs", LINUX_MIB_DELAYEDACKS),
        SNMP_MIB_ITEM("DelayedACKLocked", LINUX_MIB_DELAYEDACKLOCKED),
        SNMP_MIB_ITEM("DelayedACKLost", LINUX_MIB_DELAYEDACKLOST),
        SNMP_MIB_ITEM("ListenOverflows", LINUX_MIB_LISTENOVERFLOWS),
        SNMP_MIB_ITEM("ListenDrops", LINUX_MIB_LISTENDROPS),
        SNMP_MIB_ITEM("TCPHPHits", LINUX_MIB_TCPHPHITS),
        SNMP_MIB_ITEM("TCPPureAcks", LINUX_MIB_TCPPUREACKS),
        SNMP_MIB_ITEM("TCPHPAcks", LINUX_MIB_TCPHPACKS),
        SNMP_MIB_ITEM("TCPRenoRecovery", LINUX_MIB_TCPRENORECOVERY),
        SNMP_MIB_ITEM("TCPSackRecovery", LINUX_MIB_TCPSACKRECOVERY),
        SNMP_MIB_ITEM("TCPSACKReneging", LINUX_MIB_TCPSACKRENEGING),
        SNMP_MIB_ITEM("TCPSACKReorder", LINUX_MIB_TCPSACKREORDER),
        SNMP_MIB_ITEM("TCPRenoReorder", LINUX_MIB_TCPRENOREORDER),
        SNMP_MIB_ITEM("TCPTSReorder", LINUX_MIB_TCPTSREORDER),
        SNMP_MIB_ITEM("TCPFullUndo", LINUX_MIB_TCPFULLUNDO),
        SNMP_MIB_ITEM("TCPPartialUndo", LINUX_MIB_TCPPARTIALUNDO),
        SNMP_MIB_ITEM("TCPDSACKUndo", LINUX_MIB_TCPDSACKUNDO),
        SNMP_MIB_ITEM("TCPLossUndo", LINUX_MIB_TCPLOSSUNDO),
        SNMP_MIB_ITEM("TCPLostRetransmit", LINUX_MIB_TCPLOSTRETRANSMIT),
        SNMP_MIB_ITEM("TCPRenoFailures", LINUX_MIB_TCPRENOFAILURES),
        SNMP_MIB_ITEM("TCPSackFailures", LINUX_MIB_TCPSACKFAILURES),
        SNMP_MIB_ITEM("TCPLossFailures", LINUX_MIB_TCPLOSSFAILURES),
        SNMP_MIB_ITEM("TCPFastRetrans", LINUX_MIB_TCPFASTRETRANS),
        SNMP_MIB_ITEM("TCPSlowStartRetrans", LINUX_MIB_TCPSLOWSTARTRETRANS),
        SNMP_MIB_ITEM("TCPTimeouts", LINUX_MIB_TCPTIMEOUTS),
        SNMP_MIB_ITEM("TCPLossProbes", LINUX_MIB_TCPLOSSPROBES),
        SNMP_MIB_ITEM("TCPLossProbeRecovery", LINUX_MIB_TCPLOSSPROBERECOVERY),
        SNMP_MIB_ITEM("TCPRenoRecoveryFail", LINUX_MIB_TCPRENORECOVERYFAIL),
        SNMP_MIB_ITEM("TCPSackRecoveryFail", LINUX_MIB_TCPSACKRECOVERYFAIL),
        SNMP_MIB_ITEM("TCPRcvCollapsed", LINUX_MIB_TCPRCVCOLLAPSED),
        SNMP_MIB_ITEM("TCPBacklogCoalesce", LINUX_MIB_TCPBACKLOGCOALESCE),
        SNMP_MIB_ITEM("TCPDSACKOldSent", LINUX_MIB_TCPDSACKOLDSENT),
        SNMP_MIB_ITEM("TCPDSACKOfoSent", LINUX_MIB_TCPDSACKOFOSENT),
        SNMP_MIB_ITEM("TCPDSACKRecv", LINUX_MIB_TCPDSACKRECV),
        SNMP_MIB_ITEM("TCPDSACKOfoRecv", LINUX_MIB_TCPDSACKOFORECV),
        SNMP_MIB_ITEM("TCPAbortOnData", LINUX_MIB_TCPABORTONDATA),
        SNMP_MIB_ITEM("TCPAbortOnClose", LINUX_MIB_TCPABORTONCLOSE),
        SNMP_MIB_ITEM("TCPAbortOnMemory", LINUX_MIB_TCPABORTONMEMORY),
        SNMP_MIB_ITEM("TCPAbortOnTimeout", LINUX_MIB_TCPABORTONTIMEOUT),
        SNMP_MIB_ITEM("TCPAbortOnLinger", LINUX_MIB_TCPABORTONLINGER),
        SNMP_MIB_ITEM("TCPAbortFailed", LINUX_MIB_TCPABORTFAILED),
        SNMP_MIB_ITEM("TCPMemoryPressures", LINUX_MIB_TCPMEMORYPRESSURES),
        SNMP_MIB_ITEM("TCPMemoryPressuresChrono", LINUX_MIB_TCPMEMORYPRESSURESCHRONO),
        SNMP_MIB_ITEM("TCPSACKDiscard", LINUX_MIB_TCPSACKDISCARD),
        SNMP_MIB_ITEM("TCPDSACKIgnoredOld", LINUX_MIB_TCPDSACKIGNOREDOLD),
        SNMP_MIB_ITEM("TCPDSACKIgnoredNoUndo", LINUX_MIB_TCPDSACKIGNOREDNOUNDO),
        SNMP_MIB_ITEM("TCPSpuriousRTOs", LINUX_MIB_TCPSPURIOUSRTOS),
        SNMP_MIB_ITEM("TCPMD5NotFound", LINUX_MIB_TCPMD5NOTFOUND),
        SNMP_MIB_ITEM("TCPMD5Unexpected", LINUX_MIB_TCPMD5UNEXPECTED),
        SNMP_MIB_ITEM("TCPMD5Failure", LINUX_MIB_TCPMD5FAILURE),
        SNMP_MIB_ITEM("TCPSackShifted", LINUX_MIB_SACKSHIFTED),
        SNMP_MIB_ITEM("TCPSackMerged", LINUX_MIB_SACKMERGED),
        SNMP_MIB_ITEM("TCPSackShiftFallback", LINUX_MIB_SACKSHIFTFALLBACK),
        SNMP_MIB_ITEM("TCPBacklogDrop", LINUX_MIB_TCPBACKLOGDROP),
        SNMP_MIB_ITEM("PFMemallocDrop", LINUX_MIB_PFMEMALLOCDROP),
        SNMP_MIB_ITEM("TCPMinTTLDrop", LINUX_MIB_TCPMINTTLDROP),
        SNMP_MIB_ITEM("TCPDeferAcceptDrop", LINUX_MIB_TCPDEFERACCEPTDROP),
        SNMP_MIB_ITEM("IPReversePathFilter", LINUX_MIB_IPRPFILTER),
        SNMP_MIB_ITEM("TCPTimeWaitOverflow", LINUX_MIB_TCPTIMEWAITOVERFLOW),
        SNMP_MIB_ITEM("TCPReqQFullDoCookies", LINUX_MIB_TCPREQQFULLDOCOOKIES),
        SNMP_MIB_ITEM("TCPReqQFullDrop", LINUX_MIB_TCPREQQFULLDROP),
        SNMP_MIB_ITEM("TCPRetransFail", LINUX_MIB_TCPRETRANSFAIL),
        SNMP_MIB_ITEM("TCPRcvCoalesce", LINUX_MIB_TCPRCVCOALESCE),
        SNMP_MIB_ITEM("TCPOFOQueue", LINUX_MIB_TCPOFOQUEUE),
        SNMP_MIB_ITEM("TCPOFODrop", LINUX_MIB_TCPOFODROP),
        SNMP_MIB_ITEM("TCPOFOMerge", LINUX_MIB_TCPOFOMERGE),
        SNMP_MIB_ITEM("TCPChallengeACK", LINUX_MIB_TCPCHALLENGEACK),
        SNMP_MIB_ITEM("TCPSYNChallenge", LINUX_MIB_TCPSYNCHALLENGE),
        SNMP_MIB_ITEM("TCPFastOpenActive", LINUX_MIB_TCPFASTOPENACTIVE),
        SNMP_MIB_ITEM("TCPFastOpenActiveFail", LINUX_MIB_TCPFASTOPENACTIVEFAIL),
        SNMP_MIB_ITEM("TCPFastOpenPassive", LINUX_MIB_TCPFASTOPENPASSIVE),
        SNMP_MIB_ITEM("TCPFastOpenPassiveFail", LINUX_MIB_TCPFASTOPENPASSIVEFAIL),
        SNMP_MIB_ITEM("TCPFastOpenListenOverflow", LINUX_MIB_TCPFASTOPENLISTENOVERFLOW),
        SNMP_MIB_ITEM("TCPFastOpenCookieReqd", LINUX_MIB_TCPFASTOPENCOOKIEREQD),
        SNMP_MIB_ITEM("TCPFastOpenBlackhole", LINUX_MIB_TCPFASTOPENBLACKHOLE),
        SNMP_MIB_ITEM("TCPSpuriousRtxHostQueues", LINUX_MIB_TCPSPURIOUS_RTX_HOSTQUEUES),
        SNMP_MIB_ITEM("BusyPollRxPackets", LINUX_MIB_BUSYPOLLRXPACKETS),
        SNMP_MIB_ITEM("TCPAutoCorking", LINUX_MIB_TCPAUTOCORKING),
        SNMP_MIB_ITEM("TCPFromZeroWindowAdv", LINUX_MIB_TCPFROMZEROWINDOWADV),
        SNMP_MIB_ITEM("TCPToZeroWindowAdv", LINUX_MIB_TCPTOZEROWINDOWADV),
        SNMP_MIB_ITEM("TCPWantZeroWindowAdv", LINUX_MIB_TCPWANTZEROWINDOWADV),
        SNMP_MIB_ITEM("TCPSynRetrans", LINUX_MIB_TCPSYNRETRANS),
        SNMP_MIB_ITEM("TCPOrigDataSent", LINUX_MIB_TCPORIGDATASENT),
        SNMP_MIB_ITEM("TCPHystartTrainDetect", LINUX_MIB_TCPHYSTARTTRAINDETECT),
        SNMP_MIB_ITEM("TCPHystartTrainCwnd", LINUX_MIB_TCPHYSTARTTRAINCWND),
        SNMP_MIB_ITEM("TCPHystartDelayDetect", LINUX_MIB_TCPHYSTARTDELAYDETECT),
        SNMP_MIB_ITEM("TCPHystartDelayCwnd", LINUX_MIB_TCPHYSTARTDELAYCWND),
        SNMP_MIB_ITEM("TCPACKSkippedSynRecv", LINUX_MIB_TCPACKSKIPPEDSYNRECV),
        SNMP_MIB_ITEM("TCPACKSkippedPAWS", LINUX_MIB_TCPACKSKIPPEDPAWS),
        SNMP_MIB_ITEM("TCPACKSkippedSeq", LINUX_MIB_TCPACKSKIPPEDSEQ),
        SNMP_MIB_ITEM("TCPACKSkippedFinWait2", LINUX_MIB_TCPACKSKIPPEDFINWAIT2),
        SNMP_MIB_ITEM("TCPACKSkippedTimeWait", LINUX_MIB_TCPACKSKIPPEDTIMEWAIT),
        SNMP_MIB_ITEM("TCPACKSkippedChallenge", LINUX_MIB_TCPACKSKIPPEDCHALLENGE),
        SNMP_MIB_ITEM("TCPWinProbe", LINUX_MIB_TCPWINPROBE),
        SNMP_MIB_ITEM("TCPKeepAlive", LINUX_MIB_TCPKEEPALIVE),
        SNMP_MIB_ITEM("TCPMTUPFail", LINUX_MIB_TCPMTUPFAIL),
        SNMP_MIB_ITEM("TCPMTUPSuccess", LINUX_MIB_TCPMTUPSUCCESS),
        SNMP_MIB_ITEM("TCPDelivered", LINUX_MIB_TCPDELIVERED),
        SNMP_MIB_ITEM("TCPDeliveredCE", LINUX_MIB_TCPDELIVEREDCE),
        SNMP_MIB_ITEM("TCPAckCompressed", LINUX_MIB_TCPACKCOMPRESSED),
        SNMP_MIB_ITEM("TCPZeroWindowDrop", LINUX_MIB_TCPZEROWINDOWDROP),
        SNMP_MIB_ITEM("TCPRcvQDrop", LINUX_MIB_TCPRCVQDROP),
        SNMP_MIB_ITEM("TCPWqueueTooBig", LINUX_MIB_TCPWQUEUETOOBIG),
        SNMP_MIB_ITEM("TCPFastOpenPassiveAltKey", LINUX_MIB_TCPFASTOPENPASSIVEALTKEY),
        SNMP_MIB_ITEM("TcpTimeoutRehash", LINUX_MIB_TCPTIMEOUTREHASH),
        SNMP_MIB_ITEM("TcpDuplicateDataRehash", LINUX_MIB_TCPDUPLICATEDATAREHASH),
        SNMP_MIB_ITEM("TCPDSACKRecvSegs", LINUX_MIB_TCPDSACKRECVSEGS),
        SNMP_MIB_ITEM("TCPDSACKIgnoredDubious", LINUX_MIB_TCPDSACKIGNOREDDUBIOUS),
        SNMP_MIB_ITEM("TCPMigrateReqSuccess", LINUX_MIB_TCPMIGRATEREQSUCCESS),
        SNMP_MIB_ITEM("TCPMigrateReqFailure", LINUX_MIB_TCPMIGRATEREQFAILURE),
        SNMP_MIB_SENTINEL
};

static void icmpmsg_put_line(struct seq_file *seq, unsigned long *vals,
                             unsigned short *type, int count)
{
        int j;

        if (count) {
                seq_puts(seq, "\nIcmpMsg:");
                for (j = 0; j < count; ++j)
                        seq_printf(seq, " %sType%u",
                                type[j] & 0x100 ? "Out" : "In",
                                type[j] & 0xff);
                seq_puts(seq, "\nIcmpMsg:");
                for (j = 0; j < count; ++j)
                        seq_printf(seq, " %lu", vals[j]);
        }
}

static void icmpmsg_put(struct seq_file *seq)
{
#define PERLINE 16

        int i, count;
        unsigned short type[PERLINE];
        unsigned long vals[PERLINE], val;
        struct net *net = seq->private;

        count = 0;
        for (i = 0; i < ICMPMSG_MIB_MAX; i++) {
                val = atomic_long_read(&net->mib.icmpmsg_statistics->mibs[i]);
                if (val) {
                        type[count] = i;
                        vals[count++] = val;
                }
                if (count == PERLINE) {
                        icmpmsg_put_line(seq, vals, type, count);
                        count = 0;
                }
        }
        icmpmsg_put_line(seq, vals, type, count);

#undef PERLINE
}

static void icmp_put(struct seq_file *seq)
{
        int i;
        struct net *net = seq->private;
        atomic_long_t *ptr = net->mib.icmpmsg_statistics->mibs;

        seq_puts(seq, "\nIcmp: InMsgs InErrors InCsumErrors");
        for (i = 0; icmpmibmap[i].name; i++)
                seq_printf(seq, " In%s", icmpmibmap[i].name);
        seq_puts(seq, " OutMsgs OutErrors");
        for (i = 0; icmpmibmap[i].name; i++)
                seq_printf(seq, " Out%s", icmpmibmap[i].name);
        seq_printf(seq, "\nIcmp: %lu %lu %lu",
                snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INMSGS),
                snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_INERRORS),
                snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_CSUMERRORS));
        for (i = 0; icmpmibmap[i].name; i++)
                seq_printf(seq, " %lu",
                           atomic_long_read(ptr + icmpmibmap[i].index));
        seq_printf(seq, " %lu %lu",
                snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTMSGS),
                snmp_fold_field(net->mib.icmp_statistics, ICMP_MIB_OUTERRORS));
        for (i = 0; icmpmibmap[i].name; i++)
                seq_printf(seq, " %lu",
                           atomic_long_read(ptr + (icmpmibmap[i].index | 0x100)));
}

/*
 *      Called from the PROCfs module. This outputs /proc/net/snmp.
 */
static int snmp_seq_show_ipstats(struct seq_file *seq, void *v)
{
        struct net *net = seq->private;
        u64 buff64[IPSTATS_MIB_MAX];
        int i;

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

        seq_puts(seq, "Ip: Forwarding DefaultTTL");
        for (i = 0; snmp4_ipstats_list[i].name; i++)
                seq_printf(seq, " %s", snmp4_ipstats_list[i].name);

        seq_printf(seq, "\nIp: %d %d",
                   IPV4_DEVCONF_ALL(net, FORWARDING) ? 1 : 2,
                   net->ipv4.sysctl_ip_default_ttl);

        BUILD_BUG_ON(offsetof(struct ipstats_mib, mibs) != 0);
        snmp_get_cpu_field64_batch(buff64, snmp4_ipstats_list,
                                   net->mib.ip_statistics,
                                   offsetof(struct ipstats_mib, syncp));
        for (i = 0; snmp4_ipstats_list[i].name; i++)
                seq_printf(seq, " %llu", buff64[i]);

        return 0;
}

static int snmp_seq_show_tcp_udp(struct seq_file *seq, void *v)
{
        unsigned long buff[TCPUDP_MIB_MAX];
        struct net *net = seq->private;
        int i;

        memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));

        seq_puts(seq, "\nTcp:");
        for (i = 0; snmp4_tcp_list[i].name; i++)
                seq_printf(seq, " %s", snmp4_tcp_list[i].name);

        seq_puts(seq, "\nTcp:");
        snmp_get_cpu_field_batch(buff, snmp4_tcp_list,
                                 net->mib.tcp_statistics);
        for (i = 0; snmp4_tcp_list[i].name; i++) {
                /* MaxConn field is signed, RFC 2012 */
                if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
                        seq_printf(seq, " %ld", buff[i]);
                else
                        seq_printf(seq, " %lu", buff[i]);
        }

        memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));

        snmp_get_cpu_field_batch(buff, snmp4_udp_list,
                                 net->mib.udp_statistics);
        seq_puts(seq, "\nUdp:");
        for (i = 0; snmp4_udp_list[i].name; i++)
                seq_printf(seq, " %s", snmp4_udp_list[i].name);
        seq_puts(seq, "\nUdp:");
        for (i = 0; snmp4_udp_list[i].name; i++)
                seq_printf(seq, " %lu", buff[i]);

        memset(buff, 0, TCPUDP_MIB_MAX * sizeof(unsigned long));

        /* the UDP and UDP-Lite MIBs are the same */
        seq_puts(seq, "\nUdpLite:");
        snmp_get_cpu_field_batch(buff, snmp4_udp_list,
                                 net->mib.udplite_statistics);
        for (i = 0; snmp4_udp_list[i].name; i++)
                seq_printf(seq, " %s", snmp4_udp_list[i].name);
        seq_puts(seq, "\nUdpLite:");
        for (i = 0; snmp4_udp_list[i].name; i++)
                seq_printf(seq, " %lu", buff[i]);

        seq_putc(seq, '\n');
        return 0;
}

static int snmp_seq_show(struct seq_file *seq, void *v)
{
        snmp_seq_show_ipstats(seq, v);

        icmp_put(seq);  /* RFC 2011 compatibility */
        icmpmsg_put(seq);

        snmp_seq_show_tcp_udp(seq, v);

        return 0;
}

/*
 *      Output /proc/net/netstat
 */
static int netstat_seq_show(struct seq_file *seq, void *v)
{
        const int ip_cnt = ARRAY_SIZE(snmp4_ipextstats_list) - 1;
        const int tcp_cnt = ARRAY_SIZE(snmp4_net_list) - 1;
        struct net *net = seq->private;
        unsigned long *buff;
        int i;

        seq_puts(seq, "TcpExt:");
        for (i = 0; i < tcp_cnt; i++)
                seq_printf(seq, " %s", snmp4_net_list[i].name);

        seq_puts(seq, "\nTcpExt:");
        buff = kzalloc(max(tcp_cnt * sizeof(long), ip_cnt * sizeof(u64)),
                       GFP_KERNEL);
        if (buff) {
                snmp_get_cpu_field_batch(buff, snmp4_net_list,
                                         net->mib.net_statistics);
                for (i = 0; i < tcp_cnt; i++)
                        seq_printf(seq, " %lu", buff[i]);
        } else {
                for (i = 0; i < tcp_cnt; i++)
                        seq_printf(seq, " %lu",
                                   snmp_fold_field(net->mib.net_statistics,
                                                   snmp4_net_list[i].entry));
        }
        seq_puts(seq, "\nIpExt:");
        for (i = 0; i < ip_cnt; i++)
                seq_printf(seq, " %s", snmp4_ipextstats_list[i].name);

        seq_puts(seq, "\nIpExt:");
        if (buff) {
                u64 *buff64 = (u64 *)buff;

                memset(buff64, 0, ip_cnt * sizeof(u64));
                snmp_get_cpu_field64_batch(buff64, snmp4_ipextstats_list,
                                           net->mib.ip_statistics,
                                           offsetof(struct ipstats_mib, syncp));
                for (i = 0; i < ip_cnt; i++)
                        seq_printf(seq, " %llu", buff64[i]);
        } else {
                for (i = 0; i < ip_cnt; i++)
                        seq_printf(seq, " %llu",
                                   snmp_fold_field64(net->mib.ip_statistics,
                                                     snmp4_ipextstats_list[i].entry,
                                                     offsetof(struct ipstats_mib, syncp)));
        }
        kfree(buff);
        seq_putc(seq, '\n');
        mptcp_seq_show(seq);
        return 0;
}

static __net_init int ip_proc_init_net(struct net *net)
{
        if (!proc_create_net_single("sockstat", 0444, net->proc_net,
                        sockstat_seq_show, NULL))
                goto out_sockstat;
        if (!proc_create_net_single("netstat", 0444, net->proc_net,
                        netstat_seq_show, NULL))
                goto out_netstat;
        if (!proc_create_net_single("snmp", 0444, net->proc_net, snmp_seq_show,
                        NULL))
                goto out_snmp;

        return 0;

out_snmp:
        remove_proc_entry("netstat", net->proc_net);
out_netstat:
        remove_proc_entry("sockstat", net->proc_net);
out_sockstat:
        return -ENOMEM;
}

static __net_exit void ip_proc_exit_net(struct net *net)
{
        remove_proc_entry("snmp", net->proc_net);
        remove_proc_entry("netstat", net->proc_net);
        remove_proc_entry("sockstat", net->proc_net);
}

static __net_initdata struct pernet_operations ip_proc_ops = {
        .init = ip_proc_init_net,
        .exit = ip_proc_exit_net,
};

int __init ip_misc_proc_init(void)
{
        return register_pernet_subsys(&ip_proc_ops);
}