dns.c

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/*
   +----------------------------------------------------------------------+
   | Copyright (c) The PHP Group                                          |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | https://www.php.net/license/3_01.txt                                 |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors: The typical suspects                                        |
   |          Pollita <pollita@php.net>                                   |
   |          Marcus Boerger <helly@php.net>                              |
   +----------------------------------------------------------------------+
 */
 
/* {{{ includes */
#include "php.h"
#include "php_network.h"
 
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
 
#ifdef PHP_WIN32
# include <winsock2.h>
# include <windows.h>
# include <Ws2tcpip.h>
#else
#include <netinet/in.h>
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#include <netdb.h>
#ifdef _OSD_POSIX
#undef STATUS
#undef T_UNSPEC
#endif
#ifdef HAVE_ARPA_NAMESER_H
#ifdef __APPLE__
# define BIND_8_COMPAT 1
#endif
#include <arpa/nameser.h>
#endif
#ifdef HAVE_RESOLV_H
#include <resolv.h>
#if defined(__HAIKU__)
extern void __res_ndestroy(res_state statp);
#define res_ndestroy __res_ndestroy
#endif
#endif
#ifdef HAVE_DNS_H
#include <dns.h>
#endif
#endif
 
#ifndef MAXHOSTNAMELEN
#define MAXHOSTNAMELEN 255
#endif
 
/* For the local hostname obtained via gethostname which is different from the
   dns-related MAXHOSTNAMELEN constant above */
#ifndef HOST_NAME_MAX
#define HOST_NAME_MAX 255
#endif
 
#include "php_dns.h"
 
/* type compat */
#ifndef DNS_T_A
#define DNS_T_A     1
#endif
#ifndef DNS_T_NS
#define DNS_T_NS    2
#endif
#ifndef DNS_T_CNAME
#define DNS_T_CNAME 5
#endif
#ifndef DNS_T_SOA
#define DNS_T_SOA   6
#endif
#ifndef DNS_T_PTR
#define DNS_T_PTR   12
#endif
#ifndef DNS_T_HINFO
#define DNS_T_HINFO 13
#endif
#ifndef DNS_T_MINFO
#define DNS_T_MINFO 14
#endif
#ifndef DNS_T_MX
#define DNS_T_MX    15
#endif
#ifndef DNS_T_TXT
#define DNS_T_TXT   16
#endif
#ifndef DNS_T_AAAA
#define DNS_T_AAAA  28
#endif
#ifndef DNS_T_SRV
#define DNS_T_SRV   33
#endif
#ifndef DNS_T_NAPTR
#define DNS_T_NAPTR 35
#endif
#ifndef DNS_T_A6
#define DNS_T_A6    38
#endif
#ifndef DNS_T_CAA
#define DNS_T_CAA   257
#endif
 
#ifndef DNS_T_ANY
#define DNS_T_ANY   255
#endif
/* }}} */
 
static zend_string *php_gethostbyaddr(char *ip);
static zend_string *php_gethostbyname(char *name);
 
#ifdef HAVE_GETHOSTNAME
/* {{{ Get the host name of the current machine */
PHP_FUNCTION(gethostname)
{
    char buf[HOST_NAME_MAX + 1];
 
    ZEND_PARSE_PARAMETERS_NONE();
 
    if (gethostname(buf, sizeof(buf))) {
        php_error_docref(NULL, E_WARNING, "Unable to fetch host [%d]: %s", errno, strerror(errno));
        RETURN_FALSE;
    }
 
    RETURN_STRING(buf);
}
/* }}} */
#endif
 
/* TODO: Reimplement the gethostby* functions using the new winxp+ API, in dns_win32.c, then
 we can have a dns.c, dns_unix.c and dns_win32.c instead of a messy dns.c full of #ifdef
*/
 
/* {{{ Get the Internet host name corresponding to a given IP address */
PHP_FUNCTION(gethostbyaddr)
{
    char *addr;
    size_t addr_len;
    zend_string *hostname;
 
    ZEND_PARSE_PARAMETERS_START(1, 1)
        Z_PARAM_PATH(addr, addr_len)
    ZEND_PARSE_PARAMETERS_END();
 
    hostname = php_gethostbyaddr(addr);
 
    if (hostname == NULL) {
#ifdef HAVE_IPV6
        php_error_docref(NULL, E_WARNING, "Address is not a valid IPv4 or IPv6 address");
#else
        php_error_docref(NULL, E_WARNING, "Address is not in a.b.c.d form");
#endif
        RETVAL_FALSE;
    } else {
        RETVAL_STR(hostname);
    }
}
/* }}} */
 
/* {{{ php_gethostbyaddr */
static zend_string *php_gethostbyaddr(char *ip)
{
#ifdef HAVE_IPV6
    struct sockaddr_in sa4;
    struct sockaddr_in6 sa6;
    char out[NI_MAXHOST];
    memset(&sa4, 0, sizeof(struct sockaddr_in));
    memset(&sa6, 0, sizeof(struct sockaddr_in6));
 
    if (inet_pton(AF_INET6, ip, &sa6.sin6_addr)) {
        sa6.sin6_family = AF_INET6;
 
        if (getnameinfo((struct sockaddr *)&sa6, sizeof(sa6), out, sizeof(out), NULL, 0, NI_NAMEREQD) != 0) {
            return zend_string_init(ip, strlen(ip), 0);
        }
        return zend_string_init(out, strlen(out), 0);
    } else if (inet_pton(AF_INET, ip, &sa4.sin_addr)) {
        sa4.sin_family = AF_INET;
 
        if (getnameinfo((struct sockaddr *)&sa4, sizeof(sa4), out, sizeof(out), NULL, 0, NI_NAMEREQD) != 0) {
            return zend_string_init(ip, strlen(ip), 0);
        }
        return zend_string_init(out, strlen(out), 0);
    }
    return NULL; /* not a valid IP */
#else
    struct in_addr addr;
    struct hostent *hp;
 
    addr.s_addr = inet_addr(ip);
 
    if (addr.s_addr == -1) {
        return NULL;
    }
 
    hp = gethostbyaddr((char *) &addr, sizeof(addr), AF_INET);
 
    if (!hp || hp->h_name == NULL || hp->h_name[0] == '\0') {
        return zend_string_init(ip, strlen(ip), 0);
    }
 
    return zend_string_init(hp->h_name, strlen(hp->h_name), 0);
#endif
}
/* }}} */
 
/* {{{ Get the IP address corresponding to a given Internet host name */
PHP_FUNCTION(gethostbyname)
{
    char *hostname;
    size_t hostname_len;
    zend_string *ipaddr;
 
    ZEND_PARSE_PARAMETERS_START(1, 1)
        Z_PARAM_PATH(hostname, hostname_len)
    ZEND_PARSE_PARAMETERS_END();
 
    if (hostname_len > MAXFQDNLEN) {
        /* name too long, protect from CVE-2015-0235 */
        php_error_docref(NULL, E_WARNING, "Host name cannot be longer than %d characters", MAXFQDNLEN);
        RETURN_STRINGL(hostname, hostname_len);
    }
 
    if (!(ipaddr = php_gethostbyname(hostname))) {
        php_error_docref(NULL, E_WARNING, "Host name to ip failed %s", hostname);
        RETURN_STRINGL(hostname, hostname_len);
    } else {
        RETURN_STR(ipaddr);
    }
}
/* }}} */
 
/* {{{ Return a list of IP addresses that a given hostname resolves to. */
PHP_FUNCTION(gethostbynamel)
{
    char *hostname;
    size_t hostname_len;
    struct hostent *hp;
    struct in_addr in;
    int i;
    char addr4[INET_ADDRSTRLEN];
 
    ZEND_PARSE_PARAMETERS_START(1, 1)
        Z_PARAM_PATH(hostname, hostname_len)
    ZEND_PARSE_PARAMETERS_END();
 
    if (hostname_len > MAXFQDNLEN) {
        /* name too long, protect from CVE-2015-0235 */
        php_error_docref(NULL, E_WARNING, "Host name cannot be longer than %d characters", MAXFQDNLEN);
        RETURN_FALSE;
    }
 
    hp = php_network_gethostbyname(hostname);
    if (!hp) {
        RETURN_FALSE;
    }
 
    array_init(return_value);
 
    for (i = 0;; i++) {
        /* On macos h_addr_list entries may be misaligned. */
        const char *ipaddr;
        struct in_addr *h_addr_entry; /* Don't call this h_addr, it's a macro! */
        memcpy(&h_addr_entry, &hp->h_addr_list[i], sizeof(struct in_addr *));
        if (!h_addr_entry) {
            return;
        }
 
        in = *h_addr_entry;
        if (!(ipaddr = inet_ntop(AF_INET, &in, addr4, INET_ADDRSTRLEN))) {
            /* unlikely regarding (too) long hostname and protocols but checking still */
            php_error_docref(NULL, E_WARNING, "Host name to ip failed %s", hostname);
            continue;
        } else {
            add_next_index_string(return_value, ipaddr);
        }
    }
}
/* }}} */
 
/* {{{ php_gethostbyname */
static zend_string *php_gethostbyname(char *name)
{
    struct hostent *hp;
    struct in_addr *h_addr_0; /* Don't call this h_addr, it's a macro! */
    struct in_addr in;
    char addr4[INET_ADDRSTRLEN];
    const char *address;
 
    hp = php_network_gethostbyname(name);
    if (!hp) {
        return zend_string_init(name, strlen(name), 0);
    }
 
    /* On macos h_addr_list entries may be misaligned. */
    memcpy(&h_addr_0, &hp->h_addr_list[0], sizeof(struct in_addr *));
    if (!h_addr_0) {
        return zend_string_init(name, strlen(name), 0);
    }
 
    memcpy(&in.s_addr, h_addr_0, sizeof(in.s_addr));
 
    if (!(address = inet_ntop(AF_INET, &in, addr4, INET_ADDRSTRLEN))) {
        return NULL;
    }
 
    return zend_string_init(address, strlen(address), 0);
}
/* }}} */
 
/* Note: These functions are defined in ext/standard/dns_win32.c for Windows! */
#if !defined(PHP_WIN32) && defined(HAVE_DNS_SEARCH_FUNC)
 
#ifndef HFIXEDSZ
#define HFIXEDSZ        12      /* fixed data in header <arpa/nameser.h> */
#endif /* HFIXEDSZ */
 
#ifndef QFIXEDSZ
#define QFIXEDSZ        4       /* fixed data in query <arpa/nameser.h> */
#endif /* QFIXEDSZ */
 
#undef MAXHOSTNAMELEN
#define MAXHOSTNAMELEN  1024
 
#ifndef MAXRESOURCERECORDS
#define MAXRESOURCERECORDS  64
#endif /* MAXRESOURCERECORDS */
 
typedef union {
    HEADER qb1;
    uint8_t qb2[65536];
} querybuf;
 
/* just a hack to free resources allocated by glibc in __res_nsend()
 * See also:
 *   res_thread_freeres() in glibc/resolv/res_init.c
 *   __libc_res_nsend()   in resolv/res_send.c
 * */
 
#if defined(__GLIBC__) && !defined(HAVE_DEPRECATED_DNS_FUNCS)
#define php_dns_free_res(__res__) _php_dns_free_res(__res__)
static void _php_dns_free_res(struct __res_state *res) { /* {{{ */
    int ns;
    for (ns = 0; ns < MAXNS; ns++) {
        if (res->_u._ext.nsaddrs[ns] != NULL) {
            free (res->_u._ext.nsaddrs[ns]);
            res->_u._ext.nsaddrs[ns] = NULL;
        }
    }
} /* }}} */
#else
#define php_dns_free_res(__res__)
#endif
 
/* {{{ Check DNS records corresponding to a given Internet host name or IP address */
PHP_FUNCTION(dns_check_record)
{
    HEADER *hp;
    querybuf answer = {0};
    char *hostname;
    size_t hostname_len;
    zend_string *rectype = NULL;
    int type = DNS_T_MX, i;
#if defined(HAVE_DNS_SEARCH)
    struct sockaddr_storage from;
    uint32_t fromsize = sizeof(from);
    dns_handle_t handle;
#elif defined(HAVE_RES_NSEARCH)
    struct __res_state state;
    struct __res_state *handle = &state;
#endif
 
    ZEND_PARSE_PARAMETERS_START(1, 2)
        Z_PARAM_STRING(hostname, hostname_len)
        Z_PARAM_OPTIONAL
        Z_PARAM_STR(rectype)
    ZEND_PARSE_PARAMETERS_END();
 
    if (hostname_len == 0) {
        zend_argument_must_not_be_empty_error(1);
        RETURN_THROWS();
    }
 
    if (rectype) {
        if (zend_string_equals_literal_ci(rectype, "A")) type = DNS_T_A;
        else if (zend_string_equals_literal_ci(rectype, "NS")) type = DNS_T_NS;
        else if (zend_string_equals_literal_ci(rectype, "MX")) type = DNS_T_MX;
        else if (zend_string_equals_literal_ci(rectype, "PTR")) type = DNS_T_PTR;
        else if (zend_string_equals_literal_ci(rectype, "ANY")) type = DNS_T_ANY;
        else if (zend_string_equals_literal_ci(rectype, "SOA")) type = DNS_T_SOA;
        else if (zend_string_equals_literal_ci(rectype, "CAA")) type = DNS_T_CAA;
        else if (zend_string_equals_literal_ci(rectype, "TXT")) type = DNS_T_TXT;
        else if (zend_string_equals_literal_ci(rectype, "CNAME")) type = DNS_T_CNAME;
        else if (zend_string_equals_literal_ci(rectype, "AAAA")) type = DNS_T_AAAA;
        else if (zend_string_equals_literal_ci(rectype, "SRV")) type = DNS_T_SRV;
        else if (zend_string_equals_literal_ci(rectype, "NAPTR")) type = DNS_T_NAPTR;
        else if (zend_string_equals_literal_ci(rectype, "A6")) type = DNS_T_A6;
        else {
            zend_argument_value_error(2, "must be a valid DNS record type");
            RETURN_THROWS();
        }
    }
 
#if defined(HAVE_DNS_SEARCH)
    handle = dns_open(NULL);
    if (handle == NULL) {
        RETURN_FALSE;
    }
#elif defined(HAVE_RES_NSEARCH)
    memset(&state, 0, sizeof(state));
    if (res_ninit(handle)) {
            RETURN_FALSE;
    }
#else
    res_init();
#endif
 
    i = php_dns_search(handle, hostname, C_IN, type, answer.qb2, sizeof answer);
    php_dns_free_handle(handle);
 
    if (i < 0) {
        RETURN_FALSE;
    }
    hp = (HEADER *)&answer;
    RETURN_BOOL(ntohs(hp->ancount) != 0);
}
/* }}} */
 
#ifdef HAVE_FULL_DNS_FUNCS
 
#define CHECKCP(n) do { \
    if (cp + n > end) { \
        return NULL; \
    } \
} while (0)
 
/* {{{ php_parserr */
static uint8_t *php_parserr(uint8_t *cp, uint8_t *end, querybuf *answer, int type_to_fetch, int store, bool raw, zval *subarray)
{
    u_short type, class, dlen;
    u_long ttl;
    long n, i;
    u_short s;
    uint8_t *tp, *p;
    char name[MAXHOSTNAMELEN] = {0};
    int have_v6_break = 0, in_v6_break = 0;
 
    ZVAL_UNDEF(subarray);
 
    n = dn_expand(answer->qb2, end, cp, name, sizeof(name) - 2);
    if (n < 0) {
        return NULL;
    }
    cp += n;
 
    CHECKCP(10);
    GETSHORT(type, cp);
    GETSHORT(class, cp);
    GETLONG(ttl, cp);
    GETSHORT(dlen, cp);
    CHECKCP(dlen);
    if (dlen == 0) {
        /* No data in the response - nothing to do */
        return NULL;
    }
    if (type_to_fetch != DNS_T_ANY && type != type_to_fetch) {
        cp += dlen;
        return cp;
    }
 
    if (!store) {
        cp += dlen;
        return cp;
    }
 
    array_init(subarray);
 
    add_assoc_string(subarray, "host", name);
    add_assoc_string(subarray, "class", "IN");
    add_assoc_long(subarray, "ttl", ttl);
    (void) class;
 
    if (raw) {
        add_assoc_long(subarray, "type", type);
        add_assoc_stringl(subarray, "data", (char*) cp, (uint32_t) dlen);
        cp += dlen;
        return cp;
    }
 
    switch (type) {
        case DNS_T_A:
            CHECKCP(4);
            add_assoc_string(subarray, "type", "A");
            snprintf(name, sizeof(name), "%d.%d.%d.%d", cp[0], cp[1], cp[2], cp[3]);
            add_assoc_string(subarray, "ip", name);
            cp += dlen;
            break;
        case DNS_T_MX:
            CHECKCP(2);
            add_assoc_string(subarray, "type", "MX");
            GETSHORT(n, cp);
            add_assoc_long(subarray, "pri", n);
            ZEND_FALLTHROUGH;
        case DNS_T_CNAME:
            if (type == DNS_T_CNAME) {
                add_assoc_string(subarray, "type", "CNAME");
            }
            ZEND_FALLTHROUGH;
        case DNS_T_NS:
            if (type == DNS_T_NS) {
                add_assoc_string(subarray, "type", "NS");
            }
            ZEND_FALLTHROUGH;
        case DNS_T_PTR:
            if (type == DNS_T_PTR) {
                add_assoc_string(subarray, "type", "PTR");
            }
            n = dn_expand(answer->qb2, end, cp, name, (sizeof name) - 2);
            if (n < 0) {
                return NULL;
            }
            cp += n;
            add_assoc_string(subarray, "target", name);
            break;
        case DNS_T_HINFO:
            /* See RFC 1010 for values */
            add_assoc_string(subarray, "type", "HINFO");
            CHECKCP(1);
            n = *cp & 0xFF;
            cp++;
            CHECKCP(n);
            add_assoc_stringl(subarray, "cpu", (char*)cp, n);
            cp += n;
            CHECKCP(1);
            n = *cp & 0xFF;
            cp++;
            CHECKCP(n);
            add_assoc_stringl(subarray, "os", (char*)cp, n);
            cp += n;
            break;
        case DNS_T_CAA:
            /* See RFC 6844 for values https://tools.ietf.org/html/rfc6844 */
            add_assoc_string(subarray, "type", "CAA");
            // 1 flag byte
            CHECKCP(1);
            n = *cp & 0xFF;
            add_assoc_long(subarray, "flags", n);
            cp++;
            // Tag length (1 byte)
            CHECKCP(1);
            n = *cp & 0xFF;
            cp++;
            CHECKCP(n);
            add_assoc_stringl(subarray, "tag", (char*)cp, n);
            cp += n;
            if ( (size_t) dlen < ((size_t)n) + 2 ) {
                return NULL;
            }
            n = dlen - n - 2;
            CHECKCP(n);
            add_assoc_stringl(subarray, "value", (char*)cp, n);
            cp += n;
            break;
        case DNS_T_TXT:
            {
                int l1 = 0, l2 = 0;
                zval entries;
                zend_string *tp;
 
                add_assoc_string(subarray, "type", "TXT");
                tp = zend_string_alloc(dlen, 0);
 
                array_init(&entries);
 
                while (l1 < dlen) {
                    n = cp[l1];
                    if ((l1 + n) >= dlen) {
                        // Invalid chunk length, truncate
                        n = dlen - (l1 + 1);
                    }
                    if (n) {
                        memcpy(ZSTR_VAL(tp) + l2 , cp + l1 + 1, n);
                        add_next_index_stringl(&entries, (char *) cp + l1 + 1, n);
                    }
                    l1 = l1 + n + 1;
                    l2 = l2 + n;
                }
                ZSTR_VAL(tp)[l2] = '\0';
                ZSTR_LEN(tp) = l2;
                cp += dlen;
 
                add_assoc_str(subarray, "txt", tp);
                add_assoc_zval(subarray, "entries", &entries);
            }
            break;
        case DNS_T_SOA:
            add_assoc_string(subarray, "type", "SOA");
            n = dn_expand(answer->qb2, end, cp, name, (sizeof name) -2);
            if (n < 0) {
                return NULL;
            }
            cp += n;
            add_assoc_string(subarray, "mname", name);
            n = dn_expand(answer->qb2, end, cp, name, (sizeof name) -2);
            if (n < 0) {
                return NULL;
            }
            cp += n;
            add_assoc_string(subarray, "rname", name);
            CHECKCP(5*4);
            GETLONG(n, cp);
            add_assoc_long(subarray, "serial", n);
            GETLONG(n, cp);
            add_assoc_long(subarray, "refresh", n);
            GETLONG(n, cp);
            add_assoc_long(subarray, "retry", n);
            GETLONG(n, cp);
            add_assoc_long(subarray, "expire", n);
            GETLONG(n, cp);
            add_assoc_long(subarray, "minimum-ttl", n);
            break;
        case DNS_T_AAAA:
            tp = (uint8_t*)name;
            CHECKCP(8*2);
            for(i=0; i < 8; i++) {
                GETSHORT(s, cp);
                if (s != 0) {
                    if (tp > (uint8_t *)name) {
                        in_v6_break = 0;
                        tp[0] = ':';
                        tp++;
                    }
                    tp += snprintf((char*)tp, sizeof(name) - (tp - (uint8_t *) name), "%x", s);
                } else {
                    if (!have_v6_break) {
                        have_v6_break = 1;
                        in_v6_break = 1;
                        tp[0] = ':';
                        tp++;
                    } else if (!in_v6_break) {
                        tp[0] = ':';
                        tp++;
                        tp[0] = '0';
                        tp++;
                    }
                }
            }
            if (have_v6_break && in_v6_break) {
                tp[0] = ':';
                tp++;
            }
            tp[0] = '\0';
            add_assoc_string(subarray, "type", "AAAA");
            add_assoc_string(subarray, "ipv6", name);
            break;
        case DNS_T_A6:
            p = cp;
            add_assoc_string(subarray, "type", "A6");
            CHECKCP(1);
            n = ((int)cp[0]) & 0xFF;
            cp++;
            add_assoc_long(subarray, "masklen", n);
            tp = (uint8_t*)name;
            if (n > 15) {
                have_v6_break = 1;
                in_v6_break = 1;
                tp[0] = ':';
                tp++;
            }
            if (n % 16 > 8) {
                /* Partial short */
                if (cp[0] != 0) {
                    if (tp > (uint8_t *)name) {
                        in_v6_break = 0;
                        tp[0] = ':';
                        tp++;
                    }
                    snprintf((char*)tp, sizeof(name) - (tp - (uint8_t *) name), "%x", cp[0] & 0xFF);
                } else {
                    if (!have_v6_break) {
                        have_v6_break = 1;
                        in_v6_break = 1;
                        tp[0] = ':';
                        tp++;
                    } else if (!in_v6_break) {
                        tp[0] = ':';
                        tp++;
                        tp[0] = '0';
                        tp++;
                    }
                }
                cp++;
            }
            for (i = (n + 8) / 16; i < 8; i++) {
                CHECKCP(2);
                GETSHORT(s, cp);
                if (s != 0) {
                    if (tp > (uint8_t *)name) {
                        in_v6_break = 0;
                        tp[0] = ':';
                        tp++;
                    }
                    tp += snprintf((char*)tp, sizeof(name) - (tp - (uint8_t *) name),"%x",s);
                } else {
                    if (!have_v6_break) {
                        have_v6_break = 1;
                        in_v6_break = 1;
                        tp[0] = ':';
                        tp++;
                    } else if (!in_v6_break) {
                        tp[0] = ':';
                        tp++;
                        tp[0] = '0';
                        tp++;
                    }
                }
            }
            if (have_v6_break && in_v6_break) {
                tp[0] = ':';
                tp++;
            }
            tp[0] = '\0';
            add_assoc_string(subarray, "ipv6", name);
            if (cp < p + dlen) {
                n = dn_expand(answer->qb2, end, cp, name, (sizeof name) - 2);
                if (n < 0) {
                    return NULL;
                }
                cp += n;
                add_assoc_string(subarray, "chain", name);
            }
            break;
        case DNS_T_SRV:
            CHECKCP(3*2);
            add_assoc_string(subarray, "type", "SRV");
            GETSHORT(n, cp);
            add_assoc_long(subarray, "pri", n);
            GETSHORT(n, cp);
            add_assoc_long(subarray, "weight", n);
            GETSHORT(n, cp);
            add_assoc_long(subarray, "port", n);
            n = dn_expand(answer->qb2, end, cp, name, (sizeof name) - 2);
            if (n < 0) {
                return NULL;
            }
            cp += n;
            add_assoc_string(subarray, "target", name);
            break;
        case DNS_T_NAPTR:
            CHECKCP(2*2);
            add_assoc_string(subarray, "type", "NAPTR");
            GETSHORT(n, cp);
            add_assoc_long(subarray, "order", n);
            GETSHORT(n, cp);
            add_assoc_long(subarray, "pref", n);
 
            CHECKCP(1);
            n = (cp[0] & 0xFF);
            cp++;
            CHECKCP(n);
            add_assoc_stringl(subarray, "flags", (char*)cp, n);
            cp += n;
 
            CHECKCP(1);
            n = (cp[0] & 0xFF);
            cp++;
            CHECKCP(n);
            add_assoc_stringl(subarray, "services", (char*)cp, n);
            cp += n;
 
            CHECKCP(1);
            n = (cp[0] & 0xFF);
            cp++;
            CHECKCP(n);
            add_assoc_stringl(subarray, "regex", (char*)cp, n);
            cp += n;
 
            n = dn_expand(answer->qb2, end, cp, name, (sizeof name) - 2);
            if (n < 0) {
                return NULL;
            }
            cp += n;
            add_assoc_string(subarray, "replacement", name);
            break;
        default:
            zval_ptr_dtor(subarray);
            ZVAL_UNDEF(subarray);
            cp += dlen;
            break;
    }
 
    return cp;
}
/* }}} */
 
/* {{{ Get any Resource Record corresponding to a given Internet host name */
PHP_FUNCTION(dns_get_record)
{
    char *hostname;
    size_t hostname_len;
    zend_long type_param = PHP_DNS_ANY;
    zval *authns = NULL, *addtl = NULL;
    int type_to_fetch;
    int dns_errno;
#if defined(HAVE_DNS_SEARCH)
    struct sockaddr_storage from;
    uint32_t fromsize = sizeof(from);
    dns_handle_t handle;
#elif defined(HAVE_RES_NSEARCH)
    struct __res_state state;
    struct __res_state *handle = &state;
#endif
    HEADER *hp;
    querybuf answer = {0};
    uint8_t *cp = NULL, *end = NULL;
    int n, qd, an, ns = 0, ar = 0;
    int type, first_query = 1, store_results = 1;
    bool raw = 0;
 
    ZEND_PARSE_PARAMETERS_START(1, 5)
        Z_PARAM_STRING(hostname, hostname_len)
        Z_PARAM_OPTIONAL
        Z_PARAM_LONG(type_param)
        Z_PARAM_ZVAL(authns)
        Z_PARAM_ZVAL(addtl)
        Z_PARAM_BOOL(raw)
    ZEND_PARSE_PARAMETERS_END();
 
    if (authns) {
        authns = zend_try_array_init(authns);
        if (!authns) {
            RETURN_THROWS();
        }
    }
    if (addtl) {
        addtl = zend_try_array_init(addtl);
        if (!addtl) {
            RETURN_THROWS();
        }
    }
 
    if (!raw) {
        if ((type_param & ~PHP_DNS_ALL) && (type_param != PHP_DNS_ANY)) {
            zend_argument_value_error(2, "must be a DNS_* constant");
            RETURN_THROWS();
        }
    } else {
        if ((type_param < 1) || (type_param > 0xFFFF)) {
            zend_argument_value_error(2, "must be between 1 and 65535 when argument #5 ($raw) is true");
            RETURN_THROWS();
        }
    }
 
    /* Initialize the return array */
    array_init(return_value);
 
    /* - We emulate an or'ed type mask by querying type by type. (Steps 0 - NUMTYPES-1 )
     *   If additional info is wanted we check again with DNS_T_ANY (step NUMTYPES / NUMTYPES+1 )
     *   store_results is used to skip storing the results retrieved in step
     *   NUMTYPES+1 when results were already fetched.
     * - In case of PHP_DNS_ANY we use the directly fetch DNS_T_ANY. (step NUMTYPES+1 )
     * - In case of raw mode, we query only the requested type instead of looping type by type
     *   before going with the additional info stuff.
     */
 
    if (raw) {
        type = -1;
    } else if (type_param == PHP_DNS_ANY) {
        type = PHP_DNS_NUM_TYPES + 1;
    } else {
        type = 0;
    }
 
    for ( ;
        type < (addtl ? (PHP_DNS_NUM_TYPES + 2) : PHP_DNS_NUM_TYPES) || first_query;
        type++
    ) {
        first_query = 0;
        switch (type) {
            case -1: /* raw */
                type_to_fetch = type_param;
                /* skip over the rest and go directly to additional records */
                type = PHP_DNS_NUM_TYPES - 1;
                break;
            case 0:
                type_to_fetch = type_param&PHP_DNS_A     ? DNS_T_A     : 0;
                break;
            case 1:
                type_to_fetch = type_param&PHP_DNS_NS    ? DNS_T_NS    : 0;
                break;
            case 2:
                type_to_fetch = type_param&PHP_DNS_CNAME ? DNS_T_CNAME : 0;
                break;
            case 3:
                type_to_fetch = type_param&PHP_DNS_SOA   ? DNS_T_SOA   : 0;
                break;
            case 4:
                type_to_fetch = type_param&PHP_DNS_PTR   ? DNS_T_PTR   : 0;
                break;
            case 5:
                type_to_fetch = type_param&PHP_DNS_HINFO ? DNS_T_HINFO : 0;
                break;
            case 6:
                type_to_fetch = type_param&PHP_DNS_MX    ? DNS_T_MX    : 0;
                break;
            case 7:
                type_to_fetch = type_param&PHP_DNS_TXT   ? DNS_T_TXT   : 0;
                break;
            case 8:
                type_to_fetch = type_param&PHP_DNS_AAAA  ? DNS_T_AAAA  : 0;
                break;
            case 9:
                type_to_fetch = type_param&PHP_DNS_SRV   ? DNS_T_SRV   : 0;
                break;
            case 10:
                type_to_fetch = type_param&PHP_DNS_NAPTR ? DNS_T_NAPTR : 0;
                break;
            case 11:
                type_to_fetch = type_param&PHP_DNS_A6  ? DNS_T_A6 : 0;
                break;
            case 12:
                type_to_fetch = type_param&PHP_DNS_CAA ? DNS_T_CAA : 0;
                break;
            case PHP_DNS_NUM_TYPES:
                store_results = 0;
                continue;
            default:
            case (PHP_DNS_NUM_TYPES + 1):
                type_to_fetch = DNS_T_ANY;
                break;
        }
 
        if (type_to_fetch) {
#if defined(HAVE_DNS_SEARCH)
            handle = dns_open(NULL);
            if (handle == NULL) {
                zend_array_destroy(Z_ARR_P(return_value));
                RETURN_FALSE;
            }
#elif defined(HAVE_RES_NSEARCH)
            memset(&state, 0, sizeof(state));
            if (res_ninit(handle)) {
                zend_array_destroy(Z_ARR_P(return_value));
                RETURN_FALSE;
            }
#else
            res_init();
#endif
 
            n = php_dns_search(handle, hostname, C_IN, type_to_fetch, answer.qb2, sizeof answer);
 
            if (n < 0) {
                dns_errno = php_dns_errno(handle);
                php_dns_free_handle(handle);
                switch (dns_errno) {
                    case NO_DATA:
                    case HOST_NOT_FOUND:
                        continue;
 
                    case NO_RECOVERY:
                        php_error_docref(NULL, E_WARNING, "An unexpected server failure occurred.");
                        break;
 
                    case TRY_AGAIN:
                        php_error_docref(NULL, E_WARNING, "A temporary server error occurred.");
                        break;
 
                    default:
                        php_error_docref(NULL, E_WARNING, "DNS Query failed");
                }
                zend_array_destroy(Z_ARR_P(return_value));
                RETURN_FALSE;
            }
 
            cp = answer.qb2 + HFIXEDSZ;
            end = answer.qb2 + n;
            hp = (HEADER *)&answer;
            qd = ntohs(hp->qdcount);
            an = ntohs(hp->ancount);
            ns = ntohs(hp->nscount);
            ar = ntohs(hp->arcount);
 
            /* Skip QD entries, they're only used by dn_expand later on */
            while (qd-- > 0) {
                n = dn_skipname(cp, end);
                if (n < 0) {
                    php_error_docref(NULL, E_WARNING, "Unable to parse DNS data received");
                    zend_array_destroy(Z_ARR_P(return_value));
                    php_dns_free_handle(handle);
                    RETURN_FALSE;
                }
                cp += n + QFIXEDSZ;
            }
 
            /* YAY! Our real answers! */
            while (an-- && cp && cp < end) {
                zval retval;
 
                cp = php_parserr(cp, end, &answer, type_to_fetch, store_results, raw, &retval);
                if (Z_TYPE(retval) != IS_UNDEF && store_results) {
                    add_next_index_zval(return_value, &retval);
                }
            }
 
            if (authns || addtl) {
                /* List of Authoritative Name Servers
                 * Process when only requesting addtl so that we can skip through the section
                 */
                while (ns-- > 0 && cp && cp < end) {
                    zval retval;
 
                    cp = php_parserr(cp, end, &answer, DNS_T_ANY, authns != NULL, raw, &retval);
                    if (Z_TYPE(retval) != IS_UNDEF) {
                        add_next_index_zval(authns, &retval);
                    }
                }
            }
 
            if (addtl) {
                /* Additional records associated with authoritative name servers */
                while (ar-- > 0 && cp && cp < end) {
                    zval retval;
 
                    cp = php_parserr(cp, end, &answer, DNS_T_ANY, 1, raw, &retval);
                    if (Z_TYPE(retval) != IS_UNDEF) {
                        add_next_index_zval(addtl, &retval);
                    }
                }
            }
            php_dns_free_handle(handle);
        }
    }
}
/* }}} */
 
/* {{{ Get MX records corresponding to a given Internet host name */
PHP_FUNCTION(dns_get_mx)
{
    char *hostname;
    size_t hostname_len;
    zval *mx_list, *weight_list = NULL;
    int count, qdc;
    u_short type, weight;
    querybuf answer = {0};
    char buf[MAXHOSTNAMELEN] = {0};
    HEADER *hp;
    uint8_t *cp, *end;
    int i;
#if defined(HAVE_DNS_SEARCH)
    struct sockaddr_storage from;
    uint32_t fromsize = sizeof(from);
    dns_handle_t handle;
#elif defined(HAVE_RES_NSEARCH)
    struct __res_state state;
    struct __res_state *handle = &state;
#endif
 
    ZEND_PARSE_PARAMETERS_START(2, 3)
        Z_PARAM_STRING(hostname, hostname_len)
        Z_PARAM_ZVAL(mx_list)
        Z_PARAM_OPTIONAL
        Z_PARAM_ZVAL(weight_list)
    ZEND_PARSE_PARAMETERS_END();
 
    mx_list = zend_try_array_init(mx_list);
    if (!mx_list) {
        RETURN_THROWS();
    }
 
    if (weight_list) {
        weight_list = zend_try_array_init(weight_list);
        if (!weight_list) {
            RETURN_THROWS();
        }
    }
 
#if defined(HAVE_DNS_SEARCH)
    handle = dns_open(NULL);
    if (handle == NULL) {
        RETURN_FALSE;
    }
#elif defined(HAVE_RES_NSEARCH)
    memset(&state, 0, sizeof(state));
    if (res_ninit(handle)) {
            RETURN_FALSE;
    }
#else
    res_init();
#endif
 
    i = php_dns_search(handle, hostname, C_IN, DNS_T_MX, answer.qb2, sizeof(answer));
    if (i < 0) {
        php_dns_free_handle(handle);
        RETURN_FALSE;
    }
    hp = (HEADER *)&answer;
    cp = answer.qb2 + HFIXEDSZ;
    end = answer.qb2 + i;
    for (qdc = ntohs((unsigned short)hp->qdcount); qdc--; cp += i + QFIXEDSZ) {
        if ((i = dn_skipname(cp, end)) < 0 ) {
            php_dns_free_handle(handle);
            RETURN_FALSE;
        }
    }
    count = ntohs((unsigned short)hp->ancount);
    while (--count >= 0 && cp < end) {
        if ((i = dn_skipname(cp, end)) < 0 ) {
            php_dns_free_handle(handle);
            RETURN_FALSE;
        }
        cp += i;
        GETSHORT(type, cp);
        cp += INT16SZ + INT32SZ;
        GETSHORT(i, cp);
        if (type != DNS_T_MX) {
            cp += i;
            continue;
        }
        GETSHORT(weight, cp);
        if ((i = dn_expand(answer.qb2, end, cp, buf, sizeof(buf)-1)) < 0) {
            php_dns_free_handle(handle);
            RETURN_FALSE;
        }
        cp += i;
        add_next_index_string(mx_list, buf);
        if (weight_list) {
            add_next_index_long(weight_list, weight);
        }
    }
    php_dns_free_handle(handle);
    RETURN_BOOL(zend_hash_num_elements(Z_ARRVAL_P(mx_list)) != 0);
}
/* }}} */
#endif /* HAVE_FULL_DNS_FUNCS */
#endif /* !defined(PHP_WIN32) && HAVE_DNS_SEARCH_FUNC */