/*
 * $OpenBSD: inet.c,v 1.92 2005/02/10 14:25:08 itojun Exp $
 */
/*
 * $NetBSD: inet.c,v 1.14 1995/10/03 21:42:37 thorpej Exp $
 */

/*
 * Copyright (c) 1983, 1988, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <net-snmp/net-snmp-config.h>

#include <stdint.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_WINSOCK_H
#include "winstub.h"
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

#include <net-snmp/net-snmp-includes.h>

#include "main.h"
#include "netstat.h"

struct stat_table {
    unsigned int    entry;      /* entry number in table */
    /*
     * format string to printf(description, value)
     * warning: the %d must be before the %s
     */
    char            description[80];
};

static char    *inetname(const struct in_addr *);

        /*
         * Print a summary of connections related to
         *   an Internet protocol (kread-based) - Omitted
         */

/*
 * Print a summary of TCP connections
 * Listening processes are suppressed unless the
 *   -a (all) flag is specified.
 */
const char     *tcpstates[] = {
    "",
    "CLOSED",
    "LISTEN",
    "SYNSENT",
    "SYNRECEIVED",
    "ESTABLISHED",
    "FINWAIT1",
    "FINWAIT2",
    "CLOSEWAIT",
    "LASTACK",
    "CLOSING",
    "TIMEWAIT"
};

#define TCP_NSTATES 11

static void
tcpprotoprint_line(const char *name, netsnmp_variable_list * vp,
                   int *first)
{
    int             state, width;
    char           *cp;
    union {
        struct in_addr  addr;
        char            data[4];
    } tmpAddr;
    oid             localPort, remotePort;
    struct in_addr  localAddr, remoteAddr;

    state = *vp->val.integer;
    if (!aflag && state == MIB_TCPCONNSTATE_LISTEN) {
        return;
    }

    if (*first) {
        printf("Active Internet (%s) Connections", name);
        if (aflag)
            printf(" (including servers)");
        putchar('\n');
        width = 27;
        printf("%-5.5s %*.*s %*.*s %s\n",
               "Proto", -width, width, "Local Address",
               -width, width, "Remote Address", "(state)");
        *first = 0;
    }

    /*
     * Extract the local/remote information from the index values
     */
    cp = tmpAddr.data;
    cp[0] = (uint8_t) vp->name[10];
    cp[1] = (uint8_t) vp->name[11];
    cp[2] = (uint8_t) vp->name[12];
    cp[3] = (uint8_t) vp->name[13];
    localAddr.s_addr = tmpAddr.addr.s_addr;
    localPort = vp->name[14];
    cp = tmpAddr.data;
    cp[0] = (uint8_t) vp->name[15];
    cp[1] = (uint8_t) vp->name[16];
    cp[2] = (uint8_t) vp->name[17];
    cp[3] = (uint8_t) vp->name[18];
    remoteAddr.s_addr = tmpAddr.addr.s_addr;
    remotePort = vp->name[19];

    printf("%-5.5s", name);
    inetprint(&localAddr, localPort, name, 1);
    inetprint(&remoteAddr, remotePort, name, 0);
    if (state < 1 || state > TCP_NSTATES) {
        printf(" %d\n", state);
    } else {
        printf(" %s\n", tcpstates[state]);
    }
}

static void
tcpprotopr_get(const char *name, oid * root, size_t root_len)
{
    netsnmp_variable_list *var, *vp;
    int             first = 1;

    /*
     * Walking the tcpConnState column will provide all
     *   the necessary information.
     */
    var = NULL;
    snmp_varlist_add_variable(&var, root, root_len, ASN_NULL, NULL, 0);
    if (!var)
        return;
    if (netsnmp_query_walk(var, ss) != SNMP_ERR_NOERROR)
        return;
    if ((var->type & 0xF0) == 0x80)     /* Exception */
        return;

    for (vp = var; vp; vp = vp->next_variable) {
        tcpprotoprint_line(name, vp, &first);
    }
    snmp_free_varbind(var);
}

/*
 * Print a summary of UDP "connections"
 *    XXX - what about "listening" services ??
 */
void
udpprotopr(const char *name)
{
    netsnmp_variable_list *var, *vp;
    oid             udpLocalAddress_oid[] =
        { 1, 3, 6, 1, 2, 1, 7, 5, 1, 1 };
    size_t          udpLocalAddress_len = OID_LENGTH(udpLocalAddress_oid);
    union {
        struct in_addr  addr;
        char            data[4];
    } tmpAddr;
    struct in_addr  localAddr;
    oid             localPort;
    char           *cp;

    /*
     * Walking a single column of the udpTable will provide
     *   all the necessary information from the index values.
     */
    var = NULL;
    snmp_varlist_add_variable(&var, udpLocalAddress_oid,
                              udpLocalAddress_len, ASN_NULL, NULL, 0);
    if (!var)
        return;
    if (netsnmp_query_walk(var, ss) != SNMP_ERR_NOERROR) {
        snmp_free_varbind(var);
        return;
    }
    if ((var->type & 0xF0) == 0x80) {   /* Exception */
        snmp_free_varbind(var);
        return;
    }

    printf("Active Internet (%s) Connections\n", name);
    printf("%-5.5s %-27.27s\n", "Proto", "Local Address");
    for (vp = var; vp; vp = vp->next_variable) {
        printf("%-5.5s", name);
        /*
         * Extract the local port from the index values, but take
         *   the IP address from the varbind value, (which is why
         *   we walked udpLocalAddress rather than udpLocalPort)
         */
        cp = tmpAddr.data;
        cp[0] = (uint8_t) vp->name[10];
        cp[1] = (uint8_t) vp->name[11];
        cp[2] = (uint8_t) vp->name[12];
        cp[3] = (uint8_t) vp->name[13];
        localAddr.s_addr = tmpAddr.addr.s_addr;
        localPort = vp->name[14];
        inetprint(&localAddr, localPort, name, 1);
        putchar('\n');
    }
    snmp_free_varbind(var);
}

void
tcpprotopr_bulkget(const char *name, oid * root, size_t root_len)
{
    netsnmp_variable_list *vp;
    netsnmp_pdu    *pdu, *response;
    oid             tcpConnState_oid[MAX_OID_LEN];
    size_t          tcpConnState_len;
    int             first = 1;
    int             running = 1;
    int             status;

    /*
     * setup initial object name
     */
    memmove(tcpConnState_oid, root, sizeof(oid) * root_len);
    tcpConnState_len = root_len;

    /*
     * Walking the tcpConnState column will provide all
     *   the necessary information.
     */
    while (running) {
        /*
         * create PDU for GETBULK request and add object name to request
         */
        pdu = snmp_pdu_create(SNMP_MSG_GETBULK);
        pdu->non_repeaters = 0;
        pdu->max_repetitions = max_getbulk;     /* fill the packet */
        snmp_add_null_var(pdu, tcpConnState_oid, tcpConnState_len);

        /*
         * do the request
         */
        status = snmp_synch_response(ss, pdu, &response);
        if (status == STAT_SUCCESS) {
            if (response->errstat == SNMP_ERR_NOERROR) {
                for (vp = response->variables; vp; vp = vp->next_variable) {
                    if ((vp->name_length < root_len) ||
                        (memcmp(root, vp->name, sizeof(oid) * root_len) !=
                         0)) {
                        /*
                         * not part of this subtree
                         */
                        running = 0;
                        continue;
                    }

                    if ((vp->type != SNMP_ENDOFMIBVIEW) &&
                        (vp->type != SNMP_NOSUCHOBJECT) &&
                        (vp->type != SNMP_NOSUCHINSTANCE)) {

                        tcpprotoprint_line(name, vp, &first);

                        /*
                         * Check if last variable, and if so, save for next request.
                         */
                        if (vp->next_variable == NULL) {
                            memmove(tcpConnState_oid, vp->name,
                                    vp->name_length * sizeof(oid));
                            tcpConnState_len = vp->name_length;
                        }
                    } else {
                        /*
                         * an exception value, so stop
                         */
                        running = 0;
                    }
                }
            } else {
                /*
                 * error in response, print it
                 */
                running = 0;
            }
        } else if (status == STAT_TIMEOUT) {
            running = 0;
        } else {                /* status == STAT_ERROR */
            running = 0;
        }

        if (response) {
            snmp_free_pdu(response);
        }
    }
}

void
tcpprotopr(const char *name)
{
    oid             tcpConnState_oid[] = { 1, 3, 6, 1, 2, 1, 6, 13, 1, 1 };
    size_t          tcpConnState_len = OID_LENGTH(tcpConnState_oid);
    int             use_getbulk = 1;

#ifndef NETSNMP_DISABLE_SNMPV1
    if (ss->version == SNMP_VERSION_1) {
        use_getbulk = 0;
    }
#endif

    if (use_getbulk) {
        tcpprotopr_bulkget(name, tcpConnState_oid, tcpConnState_len);
    } else {
        tcpprotopr_get(name, tcpConnState_oid, tcpConnState_len);
    }
}


        /*********************
	 *
	 *  Internet-protocol statistics
	 *
	 *********************/

void
_dump_stats(const char *name, oid * oid_buf, size_t buf_len,
            struct stat_table *stable)
{
    netsnmp_variable_list *var, *vp;
    struct stat_table *sp;
    oid             stat;

    var = NULL;
    for (sp = stable; sp->entry; sp++) {
        oid_buf[buf_len - 2] = sp->entry;
        snmp_varlist_add_variable(&var, oid_buf, buf_len,
                                  ASN_NULL, NULL, 0);
    }

    if (netsnmp_query_get(var, ss) != SNMP_ERR_NOERROR) {
        /*
         * Need to fix and re-try SNMPv1 errors
         */
        snmp_free_varbind(var);
        return;
    }

    printf("%s:\n", name);
    sp = stable;
    for (vp = var; vp; vp = vp->next_variable, sp++) {
        /*
         * Match the returned results against
         *   the original stats table.
         */
        stat = vp->name[buf_len - 2];
        while (sp->entry < stat) {
            sp++;
            if (sp->entry == 0)
                break;
        }
        if (sp->entry > stat)
            continue;

        /*
         * Skip exceptions or missing values
         */
        if (!vp->val.integer)
            continue;
        /*
         * If '-Cs' was specified twice,
         *   then only display non-zero stats.
         */
        if (*vp->val.integer > 0 || sflag == 1) {
            printf(sp->description, *vp->val.integer,
                   plural(*vp->val.integer));
            putchar('\n');
        }
    }
    snmp_free_varbind(var);
}


/*
 * Dump IP statistics.
 */
void
ip_stats(const char *name)
{
    oid             ipstats_oid[] = { 1, 3, 6, 1, 2, 1, 4, 0, 0 };
    size_t          ipstats_len = OID_LENGTH(ipstats_oid);
    struct stat_table ipstats_tbl[] = {
        {3, "%14lu total datagram%s received"},
        {4, "%14lu datagram%s with header errors"},
        {5, "%14lu datagram%s with an invalid destination address"},
        {6, "%14lu datagram%s forwarded"},
        {7, "%14lu datagram%s with unknown protocol"},
        {8, "%14lu datagram%s discarded"},
        {9, "%14lu datagram%s delivered"},
        {10, "%14lu output datagram request%s"},
        {11, "%14lu output datagram%s discarded"},
        {12, "%14lu datagram%s with no route"},
        {14, "%14lu fragment%s received"},
        {15, "%14lu datagram%s reassembled"},
        {16, "%14lu reassembly failure%s"},
        {17, "%14lu datagram%s fragmented"},
        {18, "%14lu fragmentation failure%s"},
        {19, "%14lu fragment%s created"},
        {23, "%14lu route%s discarded"},
        {0, ""}
    };

    _dump_stats(name, ipstats_oid, ipstats_len, ipstats_tbl);
}


/*
 * Dump ICMP statistics.
 */
void
icmp_stats(const char *name)
{
    oid             icmpstats_oid[] = { 1, 3, 6, 1, 2, 1, 5, 0, 0 };
    size_t          icmpstats_len = OID_LENGTH(icmpstats_oid);
    struct stat_table icmpstats_tbl[] = {
        {1, "%14lu total message%s received"},
        {2, "%14lu message%s dropped due to errors"},
        {14, "%14lu output message request%s"},
        {15, "%14lu output message%s discarded"},
        {0, ""}
    };
    struct stat_table icmp_inhistogram[] = {
        {3, "        Destination unreachable: %lu"},
        {4, "        Time Exceeded: %lu"},
        {5, "        Parameter Problem: %lu"},
        {6, "        Source Quench: %lu"},
        {7, "        Redirect: %lu"},
        {8, "        Echo Request: %lu"},
        {9, "        Echo Reply: %lu"},
        {10, "        Timestamp Request: %lu"},
        {11, "        Timestamp Reply: %lu"},
        {12, "        Address Mask Request: %lu"},
        {13, "        Address Mask Reply: %lu"},
        {0, ""}
    };
    struct stat_table icmp_outhistogram[] = {
        {16, "        Destination unreachable: %lu"},
        {17, "        Time Exceeded: %lu"},
        {18, "        Parameter Problem: %lu"},
        {19, "        Source Quench: %lu"},
        {20, "        Redirect: %lu"},
        {21, "        Echo Request: %lu"},
        {22, "        Echo Reply: %lu"},
        {23, "        Timestamp Request: %lu"},
        {24, "        Timestamp Reply: %lu"},
        {25, "        Address Mask Request: %lu"},
        {26, "        Address Mask Reply: %lu"},
        {0, ""}
    };

    _dump_stats(name, icmpstats_oid, icmpstats_len, icmpstats_tbl);
    _dump_stats("    Input Histogram",
                icmpstats_oid, icmpstats_len, icmp_inhistogram);
    _dump_stats("    Output Histogram",
                icmpstats_oid, icmpstats_len, icmp_outhistogram);
}


/*
 * Dump TCP statistics.
 */
void
tcp_stats(const char *name)
{
    oid             tcpstats_oid[] = { 1, 3, 6, 1, 2, 1, 6, 0, 0 };
    size_t          tcpstats_len = OID_LENGTH(tcpstats_oid);
    struct stat_table tcpstats_tbl[] = {
        {5, "%14lu active open%s"},
        {6, "%14lu passive open%s"},
        {7, "%14lu failed attempt%s"},
        {8, "%14lu reset%s of established connections"},
        {9, "%14lu currently established connection%s"},
        {10, "%14lu segment%s received"},
        {11, "%14lu segment%s sent"},
        {12, "%14lu segment%s retransmitted"},
        {14, "%14lu invalid segment%s received"},
        {15, "%14lu reset%s sent"},
        {0, ""}
    };
    _dump_stats("tcp", tcpstats_oid, tcpstats_len, tcpstats_tbl);
}


/*
 * Dump UDP statistics.
 */
void
udp_stats(const char *name)
{
    oid             udpstats_oid[] = { 1, 3, 6, 1, 2, 1, 7, 0, 0 };
    size_t          udpstats_len = OID_LENGTH(udpstats_oid);
    struct stat_table udpstats_tbl[] = {
        {1, "%14lu total datagram%s received"},
        {2, "%14lu datagram%s to invalid port"},
        {3, "%14lu datagram%s dropped due to errors"},
        {4, "%14lu output datagram request%s"},
        {0, ""}
    };
    _dump_stats("udp", udpstats_oid, udpstats_len, udpstats_tbl);
}


/*
 * Omitted:
 *     Dump IGMP     statistics
 *     Dump PIM      statistics
 *     Dump AH       statistics
 *     Dump etherip  statistics
 *     Dump ESP      statistics
 *     Dump IP-in-IP statistics
 *     Dump CARP     statistics
 *     Dump pfsync   statistics
 *     Dump IPCOMP   statistics
 */

        /*
         * Utility routines
         */

/*
 * Translation of RPC service names - Omitted
 */

/*
 * Pretty print an Internet address (net address + port).
 * If the nflag was specified, use numbers instead of names.
 */
void
inetprint(const struct in_addr *in, int port, const char *proto, int local)
{
    struct servent *sp = NULL;
    char            line[80], *cp;
    int             width = 27;

    if (vflag)
        snprintf(line, sizeof line, "%s.", inetname(in));
    else
        snprintf(line, sizeof line, "%.*s.", width - 9, inetname(in));
    cp = strchr(line, '\0');
    if (!nflag && port)
        sp = getservbyport(htons((uint16_t) port), proto);
    if (sp || port == 0)
        snprintf(cp, line + sizeof line - cp, vflag ? "%s" : "%.8s",
                 sp ? sp->s_name : "*");
    /*
     * Translation of RPC service names - Omitted
     */
    else
        snprintf(cp, line + sizeof line - cp, "%d", port);
    if (vflag && width < strlen(line))
        width = strlen(line);
    printf(" %-*.*s", width, width, line);
}

/*
 * Construct an Internet address representation.
 * If the nflag has been supplied, give
 * numeric value, otherwise try for symbolic name.
 */
char           *
inetname(const struct in_addr *inp)
{
    char           *cp;
    static char     line[50];
    struct netent  *np;
    static char     domain[MAXHOSTNAMELEN];
    static int      first = 1;

    if (first && !nflag) {
        char            tmp[MAXHOSTNAMELEN];
        first = 0;
        if (gethostname(tmp, sizeof(tmp)) == 0 && (cp = strchr(tmp, '.')))
            (void) strlcpy(domain, cp + 1, sizeof domain);
        else
            domain[0] = '\0';
    }
    if (inp->s_addr == INADDR_ANY) {
        strlcpy(line, "*", sizeof(line));
    } else {
        char            host[16];

        cp = NULL;
        if (!nflag && inet_lnaof(*inp) == INADDR_ANY) {
            np = getnetbyaddr(inet_netof(*inp), AF_INET);
            if (np)
                cp = np->n_name;
        }
        if (cp == NULL) {
            struct sockaddr_in sin;

            memset(&sin, 0, sizeof(sin));
            sin.sin_family = AF_INET;
            sin.sin_addr = *inp;
            if (getnameinfo((struct sockaddr *) &sin, sizeof(sin),
                            host, sizeof(host), NULL, 0,
                            nflag ? NI_NUMERICHOST : 0) < 0)
                strlcpy(host, "?", sizeof(host));
            if ((cp = strchr(host, '.')) && !strcmp(cp + 1, domain))
                *cp = '\0';
#if defined (WIN32) || defined (cygwin)
            /*
             * Windows insists on returning the computer name for
             * 127.0.0.1 even if the hosts file lists something
             * else such as 'localhost'.  If we are trying to look
             * up 127.0.0.1, just return 'localhost'.
             */
            if (inp->s_addr == htonl(INADDR_LOOPBACK))
                strlcpy(host, "localhost", sizeof(host));
#endif
            cp = host;
        }
        strlcpy(line, cp, sizeof(line));
    }
    return line;
}