if.c

snmp的源代码,已经在我的ubuntu下编译通过

        fprintf(stderr,
                "No response when requesting number of interfaces.\n");
        return;
    }
    DEBUGMSGTL(("netstat:if", "cfg_nnets = %d\n", cfg_nnets));

    memset(curifip, 0, sizeof(curifip));
    if_table = (struct _if_info *) calloc(cfg_nnets, sizeof(*if_table));
    cur_if = if_table;

    for (ifnum = 1; ifnum <= cfg_nnets; ifnum++) {
        register char  *cp;

        request = snmp_pdu_create(SNMP_MSG_GETNEXT);
        memmove(varname, oid_ipadentaddr, sizeof(oid_ipadentaddr));
        varname_len = sizeof(oid_ipadentaddr) / sizeof(oid);
        instance = varname + 9;
        memmove(varname + 10, curifip, sizeof(curifip));
        *instance = IPIFINDEX;
        snmp_add_null_var(request, varname, varname_len);
        *instance = IPADDR;
        snmp_add_null_var(request, varname, varname_len);
        *instance = IPNETMASK;
        snmp_add_null_var(request, varname, varname_len);

        status = snmp_synch_response(Session, request, &response);
        if (status != STAT_SUCCESS
            || response->errstat != SNMP_ERR_NOERROR) {
            fprintf(stderr,
                    "SNMP request failed for interface %d, variable %ld out of %d interfaces (IP)\n",
                    ifnum, response->errindex, cfg_nnets);
            cfg_nnets = ifnum;
            break;
        }
        for (var = response->variables; var; var = var->next_variable) {
            if (snmp_get_do_debugging()) {
                print_variable(var->name, var->name_length, var);
            }
            switch (var->name[9]) {
            case IPIFINDEX:
                ifindex = *var->val.integer;
                for (cur_if = if_table;
                     cur_if < (if_table + cfg_nnets) &&
                     cur_if->ifindex != ifindex && cur_if->ifindex != 0;
                     cur_if++);
                if (cur_if >= (if_table + cfg_nnets)) {
                    fprintf(stderr,
                            "Inconsistent response from server. Aborting.\n");
                    exit(0);
                }
                cur_if->ifindex = ifindex;
                break;
            case IPADDR:
                memmove(curifip, var->name + 10, sizeof(curifip));
                memmove(&cur_if->ifip, var->val.string, sizeof(u_long));
                break;
            case IPNETMASK:
                memmove(&cur_if->netmask, var->val.string, sizeof(u_long));
            }
        }
        cur_if->ifroute.s_addr = cur_if->ifip.s_addr & cur_if->netmask;
        if (cur_if->ifroute.s_addr)
            strcpy(cur_if->route,
                   netname(cur_if->ifroute, cur_if->netmask));
        else
            strcpy(cur_if->route, "none");
        if ((i = strlen(cur_if->route)) > max_route)
            max_route = i;
        if (cur_if->ifip.s_addr)
            strcpy(cur_if->ip, routename(cur_if->ifip));
        else
            strcpy(cur_if->ip, "none");
        if ((i = strlen(cur_if->ip)) > max_ip)
            max_ip = i;

        snmp_free_pdu(response);

        memmove(varname, oid_ifname, sizeof(oid_ifname));
        varname_len = sizeof(oid_ifname) / sizeof(oid);
        ifentry = varname + 9;
        instance = varname + 10;
        request = snmp_pdu_create(SNMP_MSG_GETNEXT);

        *instance = oldindex;
        *ifentry = IFINDEX;
        snmp_add_null_var(request, varname, varname_len);
        *ifentry = IFNAME;
        snmp_add_null_var(request, varname, varname_len);
        *ifentry = IFOPERSTATUS;
        snmp_add_null_var(request, varname, varname_len);
        *ifentry = INOCTETS;
        snmp_add_null_var(request, varname, varname_len);
        *ifentry = OUTOCTETS;
        snmp_add_null_var(request, varname, varname_len);

        while ((status =
                snmp_synch_response(Session, request,
                                    &response)) == STAT_SUCCESS) {
            if (response->errstat != SNMP_ERR_NOSUCHNAME)
                break;
            if ((request =
                 snmp_fix_pdu(response, SNMP_MSG_GETNEXT)) == NULL)
                break;
            snmp_free_pdu(response);
        }
        if (status != STAT_SUCCESS
            || response->errstat != SNMP_ERR_NOERROR) {
            fprintf(stderr,
                    "SNMP request failed for interface %d, variable %ld out of %d interfaces (IF)\n",
                    ifnum, response->errindex, cfg_nnets);
            cfg_nnets = ifnum;
            break;
        }
        for (var = response->variables; var; var = var->next_variable) {
            if (snmp_get_do_debugging()) {
                print_variable(var->name, var->name_length, var);
            }
            if (!var->val.integer)
                continue;
            switch (var->name[9]) {
            case IFINDEX:
                ifindex = *var->val.integer;
                for (cur_if = if_table;
                     cur_if < (if_table + cfg_nnets) &&
                     cur_if->ifindex != ifindex && cur_if->ifindex != 0;
                     cur_if++);
                if (cur_if >= (if_table + cfg_nnets)) {
                    fprintf(stderr,
                            "Inconsistent response from server. Aborting.\n");
                    exit(0);
                }
                cur_if->ifindex = ifindex;
                break;
            case INOCTETS:
                sprintf(cur_if->ioctets, "%lu", *var->val.integer);
                i = strlen(cur_if->ioctets);
                if (i > max_ioctets)
                    max_ioctets = i;
                break;
            case OUTOCTETS:
                sprintf(cur_if->ooctets, "%lu", *var->val.integer);
                i = strlen(cur_if->ooctets);
                if (i > max_ooctets)
                    max_ooctets = i;
                break;
            case IFNAME:
                oldindex = var->name[10];
                if (var->val_len >= sizeof(cur_if->name))
                    var->val_len = sizeof(cur_if->name) - 1;
                memmove(cur_if->name, var->val.string, var->val_len);
                cur_if->name[var->val_len] = 0;
                if ((i = strlen(cur_if->name) + 1) > max_name)
                    max_name = i;
                break;
            case IFOPERSTATUS:
                cur_if->operstatus = *var->val.integer;
                break;
            }
        }

        snmp_free_pdu(response);

        if (intrface != NULL && strcmp(cur_if->name, intrface) != 0) {
            cur_if->name[0] = 0;
            continue;
        }
        if (cur_if->operstatus != MIB_IFSTATUS_UP) {
            cp = strchr(cur_if->name, '\0');
            *cp++ = '*';
            *cp = '\0';
        }
    }

    printf("%*.*s %*.*s %*.*s %*.*s %*.*s ",
           -max_name, max_name, "Name",
           -max_route, max_route, "Network",
           -max_ip, max_ip, "Address",
           max_ioctets, max_ioctets, "Ioctets",
           max_ooctets, max_ooctets, "Ooctets");
    putchar('\n');
    for (ifnum = 0, cur_if = if_table; ifnum < cfg_nnets;
         ifnum++, cur_if++) {
        if (cur_if->name[0] == 0)
            continue;
        printf("%*.*s ", -max_name, max_name, cur_if->name);
        printf("%*.*s ", -max_route, max_route, cur_if->route);
        printf("%*.*s ", -max_ip, max_ip, cur_if->ip);
        printf("%*s %*s", max_ioctets, cur_if->ioctets,
               max_ioctets, cur_if->ooctets);
        putchar('\n');
    }
    free(if_table);
}

#define	MAXIF	128
struct iftot {
    char            ift_name[128];      /* interface name */
    unsigned int    ift_ip;     /* input packets */
    unsigned int    ift_ie;     /* input errors */
    unsigned int    ift_op;     /* output packets */
    unsigned int    ift_oe;     /* output errors */
    unsigned int    ift_co;     /* collisions */
} iftot[MAXIF];

u_char          signalled;      /* set if alarm goes off "early" */

/*
 * timerSet sets or resets the timer to fire in "interval" seconds.
 * timerPause waits only if the timer has not fired.
 * timing precision is not considered important.
 */

#if (defined(WIN32) || defined(cygwin))
static int      sav_int;
static time_t   timezup;
static void
timerSet(int interval_seconds)
{
    sav_int = interval_seconds;
    timezup = time(0) + interval_seconds;
}

/*
 * you can do better than this ! 
 */
static void
timerPause(void)
{
    time_t          now;
    while (time(&now) < timezup)
#ifdef WIN32
        Sleep(400);
#else
    {
        struct timeval  tx;
        tx.tv_sec = 0;
        tx.tv_usec = 400 * 1000;        /* 400 milliseconds */
        select(0, 0, 0, 0, &tx);
    }
#endif
}

#else

/*
 * Called if an interval expires before sidewaysintpr has completed a loop.
 * Sets a flag to not wait for the alarm.
 */
RETSIGTYPE
catchalarm(int sig)
{
    signalled = YES;
}

static void
timerSet(int interval_seconds)
{
#ifdef HAVE_SIGSET
    (void) sigset(SIGALRM, catchalarm);
#else
    (void) signal(SIGALRM, catchalarm);
#endif
    signalled = NO;
    (void) alarm(interval_seconds);
}

static void
timerPause(void)
{
#ifdef HAVE_SIGHOLD
    sighold(SIGALRM);
    if (!signalled) {
        sigpause(SIGALRM);
    }
#else
    int             oldmask;
    oldmask = sigblock(sigmask(SIGALRM));
    if (!signalled) {
        sigpause(0);
    }
    sigsetmask(oldmask);
#endif
}

#endif                          /* !WIN32 && !cygwin */

/*
 * Print a running summary of interface statistics.
 * Repeat display every interval seconds, showing statistics
 * collected over that interval.  Assumes that interval is non-zero.
 * First line printed at top of screen is always cumulative.
 */
static void
sidewaysintpr(unsigned int interval)
{
    register struct iftot *ip, *total;
    register int    line;
    struct iftot   *lastif, *sum, *interesting, ifnow, *now = &ifnow;
    netsnmp_variable_list *var;
    oid             varname[MAX_OID_LEN], *instance, *ifentry;
    size_t          varname_len;
    int             ifnum, cfg_nnets;

    lastif = iftot;
    sum = iftot + MAXIF - 1;
    total = sum - 1;
    interesting = iftot;
    var =
        getvarbyname(Session, oid_cfg_nnets,
                     sizeof(oid_cfg_nnets) / sizeof(oid));
    if (var) {
        cfg_nnets = *var->val.integer;
        snmp_free_var(var);
    } else
        return;
    memmove(varname, oid_ifname, sizeof(oid_ifname));
    varname_len = sizeof(oid_ifname) / sizeof(oid);
    for (ifnum = 1, ip = iftot; ifnum <= cfg_nnets; ifnum++) {
        char           *cp;

        ip->ift_name[0] = '(';
        varname[10] = ifnum;
        var = getvarbyname(Session, varname, varname_len);
        if (var) {
            if (var->val_len >= (sizeof(ip->ift_name) - 3))
                var->val_len = (sizeof(ip->ift_name) - 4);
            memmove(ip->ift_name + 1, var->val.string, var->val_len);
            snmp_free_var(var);
        }
        cp = (char *) strchr(ip->ift_name, ' ');
        if (cp != NULL)
            *cp = '\0';
        if (intrface && strcmp(ip->ift_name + 1, intrface) == 0)
            interesting = ip;
        ip->ift_name[15] = '\0';
        cp = (char *) strchr(ip->ift_name, '\0');
        sprintf(cp, ")");
        ip++;
        if (ip >= iftot + MAXIF - 2)
            break;
    }
    lastif = ip;

    timerSet(interval);

  banner:
    printf("     input   %-6.6s     output       ", interesting->ift_name);
    if (lastif - iftot > 0)
        printf("                 input  (Total)     output");
    for (ip = iftot; ip < iftot + MAXIF; ip++) {
        ip->ift_ip = 0;
        ip->ift_ie = 0;
        ip->ift_op = 0;
        ip->ift_oe = 0;
        ip->ift_co = 0;
    }
    putchar('\n');
    printf("%10.10s %8.8s %10.10s %8.8s %8.8s ",
           "packets", "errs", "packets", "errs", "colls");
    if (lastif - iftot > 0)
        printf("%10.10s %8.8s %10.10s %8.8s %8.8s ",
               "packets", "errs", "packets", "errs", "colls");
    putchar('\n');
    fflush(stdout);
    line = 0;
  loop:
    sum->ift_ip = 0;
    sum->ift_ie = 0;
    sum->ift_op = 0;
    sum->ift_oe = 0;
    sum->ift_co = 0;
    memmove(varname, oid_ifinucastpkts, sizeof(oid_ifinucastpkts));
    varname_len = sizeof(oid_ifinucastpkts) / sizeof(oid);
    ifentry = varname + 9;
    instance = varname + 10;
    for (ifnum = 1, ip = iftot; ifnum <= cfg_nnets && ip < lastif;
         ip++, ifnum++) {
        memset(now, 0, sizeof(*now));
        *instance = ifnum;
        *ifentry = INUCASTPKTS;
        var = getvarbyname(Session, varname, varname_len);
        if (var) {
            now->ift_ip = *var->val.integer;
            snmp_free_var(var);
        }
        *ifentry = INNUCASTPKTS;
        var = getvarbyname(Session, varname, varname_len);
        if (var) {
            now->ift_ip += *var->val.integer;
            snmp_free_var(var);
        }
        *ifentry = INERRORS;
        var = getvarbyname(Session, varname, varname_len);
        if (var) {
            now->ift_ie = *var->val.integer;
            snmp_free_var(var);
        }
        *ifentry = OUTUCASTPKTS;
        var = getvarbyname(Session, varname, varname_len);
        if (var) {
            now->ift_op = *var->val.integer;
            snmp_free_var(var);
        }
        *ifentry = OUTNUCASTPKTS;
        var = getvarbyname(Session, varname, varname_len);
        if (var) {
            now->ift_op += *var->val.integer;
            snmp_free_var(var);
        }
        *ifentry = OUTERRORS;
        var = getvarbyname(Session, varname, varname_len);
        if (var) {
            now->ift_oe = *var->val.integer;
            snmp_free_var(var);
        }

        if (ip == interesting)
            printf("%10d %8d %10d %8d %8d ",
                   now->ift_ip - ip->ift_ip,
                   now->ift_ie - ip->ift_ie,
                   now->ift_op - ip->ift_op,
                   now->ift_oe - ip->ift_oe, now->ift_co - ip->ift_co);
        ip->ift_ip = now->ift_ip;
        ip->ift_ie = now->ift_ie;
        ip->ift_op = now->ift_op;
        ip->ift_oe = now->ift_oe;
        ip->ift_co = now->ift_co;
        sum->ift_ip += ip->ift_ip;
        sum->ift_ie += ip->ift_ie;
        sum->ift_op += ip->ift_op;
        sum->ift_oe += ip->ift_oe;
        sum->ift_co += ip->ift_co;
    }
    if (lastif - iftot > 0)
        printf("%10d %8d %10d %8d %8d ",
               sum->ift_ip - total->ift_ip,
               sum->ift_ie - total->ift_ie,
               sum->ift_op - total->ift_op,
               sum->ift_oe - total->ift_oe, sum->ift_co - total->ift_co);
    *total = *sum;
    putchar('\n');
    fflush(stdout);
    line++;

    timerPause();
    timerSet(interval);

    if (line == 21)
        goto banner;
    goto loop;
 /*NOTREACHED*/}