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

#if HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <stdio.h>
#if HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <ctype.h>
#include <sys/types.h>
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#if HAVE_SYS_WAIT_H
# include <sys/wait.h>
#endif
#ifdef HAVE_LIMITS_H
#include <limits.h>
#endif
#if HAVE_WINSOCK_H
#include <winsock.h>
#endif
#ifdef WIN32
#include <limits.h>
#endif

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

#include "struct.h"
#include "pass.h"
#include "extensible.h"
#include "util_funcs.h"

struct extensible *passthrus = NULL;
int             numpassthrus = 0;

/*
 * the relocatable extensible commands variables 
 */
struct variable2 extensible_passthru_variables[] = {
    /*
     * bogus entry.  Only some of it is actually used. 
     */
    {MIBINDEX, ASN_INTEGER, RWRITE, var_extensible_pass, 0, {MIBINDEX}},
};



/*
 * lexicographical compare two object identifiers.
 * * Returns -1 if name1 < name2,
 * *          0 if name1 = name2,
 * *          1 if name1 > name2
 * *
 * * This method differs from snmp_oid_compare
 * * in that the comparison stops at the length
 * * of the smallest object identifier.
 */
int
snmp_oid_min_compare(const oid * in_name1,
                     size_t len1, const oid * in_name2, size_t len2)
{
    register int    len;
    register const oid *name1 = in_name1;
    register const oid *name2 = in_name2;

    /*
     * len = minimum of len1 and len2 
     */
    if (len1 < len2)
        len = len1;
    else
        len = len2;
    /*
     * find first non-matching OID 
     */
    while (len-- > 0) {
        /*
         * these must be done in seperate comparisons, since
         * subtracting them and using that result has problems with
         * subids > 2^31. 
         */
        if (*(name1) < *(name2))
            return -1;
        if (*(name1++) > *(name2++))
            return 1;
    }
    /*
     * both OIDs equal up to length of shorter OID 
     */

    return 0;
}


/*
 * This is also called from pass_persist.c 
 */
int
asc2bin(char *p)
{
    char           *r, *q = p;
    char            c;
    int             n = 0;

    for (;;) {
        c = (char) strtol(q, &r, 16);
        if (r == q)
            break;
        *p++ = c;
        q = r;
        n++;
    }
    return n;
}

/*
 * This is also called from pass_persist.c 
 */
int
bin2asc(char *p, size_t n)
{
    int             i, flag = 0;
    char            buffer[SNMP_MAXBUF];

    /* prevent buffer overflow */
    if ((int)n > (sizeof(buffer) - 1))
        n = sizeof(buffer) - 1;

    for (i = 0; i < (int) n; i++) {
        buffer[i] = p[i];
        if (!isprint(p[i]))
            flag = 1;
    }
    if (flag == 0) {
        p[n] = 0;
        return n;
    }
    for (i = 0; i < (int) n; i++) {
        sprintf(p, "%02x ", (unsigned char) (buffer[i] & 0xff));
        p += 3;
    }
    *--p = 0;
    return 3 * n - 1;
}

void
init_pass(void)
{
    snmpd_register_config_handler("pass", pass_parse_config,
                                  pass_free_config, "miboid command");
}

void
pass_parse_config(const char *token, char *cptr)
{
    struct extensible **ppass = &passthrus, **etmp, *ptmp;
    char           *tcptr, *endopt;
    int             i, priority;

    /*
     * options
     */
    priority = DEFAULT_MIB_PRIORITY;
    while (*cptr == '-') {
      cptr++;
      switch (*cptr) {
      case 'p':
	/* change priority level */
	cptr++;
	cptr = skip_white(cptr);
	if (! isdigit(*cptr)) {
	  config_perror("priority must be an integer");
	  return;
	}
	priority = strtol((const char*) cptr, &endopt, 0);
	if ((priority == LONG_MIN) || (priority == LONG_MAX)) {
	  config_perror("priority under/overflow");
	  return;
	}
	cptr = endopt;
	cptr = skip_white(cptr);
	break;
      default:
	config_perror("unknown option for pass directive");
	return;
      }
    }

    /*
     * MIB
     */
    if (*cptr == '.')
        cptr++;
    if (!isdigit(*cptr)) {
        config_perror("second token is not a OID");
        return;
    }
    numpassthrus++;

    while (*ppass != NULL)
        ppass = &((*ppass)->next);
    (*ppass) = (struct extensible *) malloc(sizeof(struct extensible));
    if (*ppass == NULL)
        return;
    (*ppass)->type = PASSTHRU;

    (*ppass)->miblen = parse_miboid(cptr, (*ppass)->miboid);
    while (isdigit(*cptr) || *cptr == '.')
        cptr++;
    /*
     * path
     */
    cptr = skip_white(cptr);
    if (cptr == NULL) {
        config_perror("No command specified on pass line");
        (*ppass)->command[0] = 0;
    } else {
        for (tcptr = cptr; *tcptr != 0 && *tcptr != '#' && *tcptr != ';';
             tcptr++);
        strncpy((*ppass)->command, cptr, tcptr - cptr);
        (*ppass)->command[tcptr - cptr] = 0;
    }
    strncpy((*ppass)->name, (*ppass)->command, sizeof((*ppass)->name));
    (*ppass)->name[ sizeof((*ppass)->name)-1 ] = 0;
    (*ppass)->next = NULL;

    register_mib_priority("pass", (struct variable *) extensible_passthru_variables,
			  sizeof(struct variable2),
			  1, (*ppass)->miboid, (*ppass)->miblen, priority);

    /*
     * argggg -- pasthrus must be sorted 
     */
    if (numpassthrus > 1) {
        etmp = (struct extensible **)
            malloc(((sizeof(struct extensible *)) * numpassthrus));
        if (etmp == NULL)
            return;

        for (i = 0, ptmp = (struct extensible *) passthrus;
             i < numpassthrus && ptmp != 0; i++, ptmp = ptmp->next)
            etmp[i] = ptmp;
        qsort(etmp, numpassthrus, sizeof(struct extensible *),
              pass_compare);
        passthrus = (struct extensible *) etmp[0];
        ptmp = (struct extensible *) etmp[0];

        for (i = 0; i < numpassthrus - 1; i++) {
            ptmp->next = etmp[i + 1];
            ptmp = ptmp->next;
        }
        ptmp->next = NULL;
        free(etmp);
    }
}

void
pass_free_config(void)
{
    struct extensible *etmp, *etmp2;

    for (etmp = passthrus; etmp != NULL;) {
        etmp2 = etmp;
        etmp = etmp->next;
        unregister_mib(etmp2->miboid, etmp2->miblen);
        free(etmp2);
    }
    passthrus = NULL;
    numpassthrus = 0;
}

u_char         *
var_extensible_pass(struct variable *vp,
                    oid * name,
                    size_t * length,
                    int exact,
                    size_t * var_len, WriteMethod ** write_method)
{
    oid             newname[MAX_OID_LEN];
    int             i, rtest, fd, newlen;
    static long     long_ret;
    static in_addr_t addr_ret;
    char            buf[SNMP_MAXBUF];
    static char     buf2[SNMP_MAXBUF];
    static oid      objid[MAX_OID_LEN];
    struct extensible *passthru;
    FILE           *file;

    long_ret = *length;
    for (i = 1; i <= numpassthrus; i++) {
        passthru = get_exten_instance(passthrus, i);
        rtest = snmp_oid_min_compare(name, *length,
                                     passthru->miboid, passthru->miblen);
        if ((exact && rtest == 0) || (!exact && rtest <= 0)) {
            /*
             * setup args 
             */
            if (passthru->miblen >= *length || rtest < 0)
                sprint_mib_oid(buf, passthru->miboid, passthru->miblen);
            else
                sprint_mib_oid(buf, name, *length);
            if (exact)
                snprintf(passthru->command, sizeof(passthru->command),
                         "%s -g %s", passthru->name, buf);
            else
                snprintf(passthru->command, sizeof(passthru->command),
                         "%s -n %s", passthru->name, buf);
            passthru->command[ sizeof(passthru->command)-1 ] = 0;
            DEBUGMSGTL(("ucd-snmp/pass", "pass-running:  %s\n",
                        passthru->command));
            /*
             * valid call.  Exec and get output 
             */
            if ((fd = get_exec_output(passthru)) != -1) {
                file = fdopen(fd, "r");
                if (fgets(buf, sizeof(buf), file) == NULL) {
                    fclose(file);
                    wait_on_exec(passthru);
                    if (exact) {
                        /*
                         * to enable creation
                         */
                        *write_method = setPass;
                        *var_len = 0;
                        return (NULL);
                    }
                    continue;
                }
                newlen = parse_miboid(buf, newname);

                /*
                 * its good, so copy onto name/length 
                 */
                memcpy((char *) name, (char *) newname,
                       (int) newlen * sizeof(oid));
                *length = newlen;

                /*
                 * set up return pointer for setable stuff 
                 */
                *write_method = setPass;

                if (newlen == 0 || fgets(buf, sizeof(buf), file) == NULL
                    || fgets(buf2, sizeof(buf2), file) == NULL) {
                    *var_len = 0;
                    fclose(file);
                    wait_on_exec(passthru);
                    return (NULL);
                }
                fclose(file);
                wait_on_exec(passthru);

                /*
                 * buf contains the return type, and buf2 contains the data 
                 */
                if (!strncasecmp(buf, "string", 6)) {
                    buf2[strlen(buf2) - 1] = 0; /* zap the linefeed */
                    *var_len = strlen(buf2);
                    vp->type = ASN_OCTET_STR;
                    return ((unsigned char *) buf2);
                } else if (!strncasecmp(buf, "integer", 7)) {
                    *var_len = sizeof(long_ret);
                    long_ret = strtol(buf2, NULL, 10);
                    vp->type = ASN_INTEGER;
                    return ((unsigned char *) &long_ret);
                } else if (!strncasecmp(buf, "unsigned", 8)) {
                    *var_len = sizeof(long_ret);
                    long_ret = strtoul(buf2, NULL, 10);
                    vp->type = ASN_UNSIGNED;
                    return ((unsigned char *) &long_ret);
                } else if (!strncasecmp(buf, "counter", 7)) {
                    *var_len = sizeof(long_ret);
                    long_ret = strtoul(buf2, NULL, 10);
                    vp->type = ASN_COUNTER;
                    return ((unsigned char *) &long_ret);
                } else if (!strncasecmp(buf, "octet", 5)) {
                    *var_len = asc2bin(buf2);
                    vp->type = ASN_OCTET_STR;
                    return ((unsigned char *) buf2);
                } else if (!strncasecmp(buf, "opaque", 6)) {
                    *var_len = asc2bin(buf2);
                    vp->type = ASN_OPAQUE;
                    return ((unsigned char *) buf2);
                } else if (!strncasecmp(buf, "gauge", 5)) {
                    *var_len = sizeof(long_ret);
                    long_ret = strtoul(buf2, NULL, 10);
                    vp->type = ASN_GAUGE;
                    return ((unsigned char *) &long_ret);
                } else if (!strncasecmp(buf, "objectid", 8)) {
                    newlen = parse_miboid(buf2, objid);
                    *var_len = newlen * sizeof(oid);
                    vp->type = ASN_OBJECT_ID;
                    return ((unsigned char *) objid);
                } else if (!strncasecmp(buf, "timetick", 8)) {
                    *var_len = sizeof(long_ret);
                    long_ret = strtoul(buf2, NULL, 10);
                    vp->type = ASN_TIMETICKS;
                    return ((unsigned char *) &long_ret);
                } else if (!strncasecmp(buf, "ipaddress", 9)) {
                    newlen = parse_miboid(buf2, objid);
                    if (newlen != 4) {
                        snmp_log(LOG_ERR,
                                 "invalid ipaddress returned:  %s\n",
                                 buf2);
                        *var_len = 0;
                        return (NULL);
                    }
                    addr_ret =
                        (objid[0] << (8 * 3)) + (objid[1] << (8 * 2)) +
                        (objid[2] << 8) + objid[3];
                    addr_ret = htonl(addr_ret);
                    *var_len = sizeof(addr_ret);
                    vp->type = ASN_IPADDRESS;
                    return ((unsigned char *) &addr_ret);
                }
            }
            *var_len = 0;
            return (NULL);
        }
    }
    if (var_len)
        *var_len = 0;
    *write_method = NULL;
    return (NULL);
}

int
setPass(int action,
        u_char * var_val,
        u_char var_val_type,
        size_t var_val_len, u_char * statP, oid * name, size_t name_len)
{
    int             i, rtest;
    struct extensible *passthru;

    char            buf[SNMP_MAXBUF], buf2[SNMP_MAXBUF];
    long            tmp;
    unsigned long   utmp;

    for (i = 1; i <= numpassthrus; i++) {
        passthru = get_exten_instance(passthrus, i);
        rtest = snmp_oid_min_compare(name, name_len,
                                     passthru->miboid, passthru->miblen);
        if (rtest <= 0) {
            if (action != ACTION)
                return SNMP_ERR_NOERROR;
            /*
             * setup args 
             */
            if (passthru->miblen >= name_len || rtest < 0)
                sprint_mib_oid(buf, passthru->miboid, passthru->miblen);
            else
                sprint_mib_oid(buf, name, name_len);
            snprintf(passthru->command, sizeof(passthru->command),
                     "%s -s %s ", passthru->name, buf);
            passthru->command[ sizeof(passthru->command)-1 ] = 0;
            switch (var_val_type) {
            case ASN_INTEGER:
            case ASN_COUNTER:
            case ASN_GAUGE:
            case ASN_TIMETICKS:
                tmp = *((long *) var_val);
                switch (var_val_type) {
                case ASN_INTEGER:
                    sprintf(buf, "integer %d\n", (int) tmp);
                    break;
                case ASN_COUNTER:
                    sprintf(buf, "counter %d\n", (int) tmp);
                    break;
                case ASN_GAUGE:
                    sprintf(buf, "gauge %d\n", (int) tmp);
                    break;
                case ASN_TIMETICKS:
                    sprintf(buf, "timeticks %d\n", (int) tmp);
                    break;
                }
                break;
            case ASN_IPADDRESS:
                utmp = *((u_long *) var_val);
                utmp = ntohl(utmp);
                sprintf(buf, "ipaddress %d.%d.%d.%d\n",
                        (int) ((utmp & 0xff000000) >> (8 * 3)),
                        (int) ((utmp & 0xff0000) >> (8 * 2)),
                        (int) ((utmp & 0xff00) >> (8)),
                        (int) ((utmp & 0xff)));
                break;
            case ASN_OCTET_STR:
                memcpy(buf2, var_val, var_val_len);
                if (var_val_len == 0)
                    sprintf(buf, "string \"\"\n");
                else if (bin2asc(buf2, var_val_len) == (int) var_val_len)
                    snprintf(buf, sizeof(buf), "string \"%s\"\n", buf2);
                else
                    snprintf(buf, sizeof(buf), "octet \"%s\"\n", buf2);
                buf[ sizeof(buf)-1 ] = 0;
                break;
            case ASN_OBJECT_ID:
                sprint_mib_oid(buf2, (oid *) var_val, var_val_len/sizeof(oid));
                snprintf(buf, sizeof(buf), "objectid \"%s\"\n", buf2);
                buf[ sizeof(buf)-1 ] = 0;
                break;
            }
            strncat(passthru->command, buf, sizeof(passthru->command)-strlen(passthru->command)-1);
            passthru->command[ sizeof(passthru->command)-1 ] = 0;
            DEBUGMSGTL(("ucd-snmp/pass", "pass-running:  %s",
                        passthru->command));
            exec_command(passthru);
            DEBUGMSGTL(("ucd-snmp/pass", "pass-running returned: %s",
                        passthru->output));
            if (!strncasecmp(passthru->output, "not-writable", 12)) {
                return SNMP_ERR_NOTWRITABLE;
            } else if (!strncasecmp(passthru->output, "wrong-type", 10)) {
                return SNMP_ERR_WRONGTYPE;
            }
            return SNMP_ERR_NOERROR;
        }
    }
    if (snmp_get_do_debugging()) {
        sprint_mib_oid(buf2, name, name_len);
        DEBUGMSGTL(("ucd-snmp/pass", "pass-notfound:  %s\n", buf2));
    }
    return SNMP_ERR_NOSUCHNAME;
}

int
pass_compare(const void *a, const void *b)
{
    const struct extensible *const *ap, *const *bp;
    ap = (const struct extensible * const *) a;
    bp = (const struct extensible * const *) b;
    return snmp_oid_compare((*ap)->miboid, (*ap)->miblen, (*bp)->miboid,
                            (*bp)->miblen);
}
