Class: Libnet

Inherits:
Object
  • Object
show all
Defined in:
lib/libnet4r/header.rb,
lib/libnet4r/libnet.rb,
lib/libnet4r/helpers.rb,
ext/libnet.c

Defined Under Namespace

Modules: Helpers Classes: ARP, Ethernet, Header, IPv4, IPv6, TCP, UDP, VLAN

Constant Summary collapse

HL_802_1Q =

libnet header length constants

INT2FIX(LIBNET_802_1Q_H)
HL_802_1X = 
INT2FIX(LIBNET_802_1X_H)
HL_802_2 = 
INT2FIX(LIBNET_802_2_H)
HL_802_2SNAP = 
INT2FIX(LIBNET_802_2SNAP_H)
HL_802_3 = 
INT2FIX(LIBNET_802_3_H)
HL_ARP = 
INT2FIX(LIBNET_ARP_H)
HL_ARP_ETH_IP = 
INT2FIX(LIBNET_ARP_ETH_IP_H)
HL_BGP4_HEADER = 
INT2FIX(LIBNET_BGP4_HEADER_H)
HL_BGP4_OPEN = 
INT2FIX(LIBNET_BGP4_OPEN_H)
HL_BGP4_UPDATE = 
INT2FIX(LIBNET_BGP4_UPDATE_H)
HL_BGP4_NOTIFICATION = 
INT2FIX(LIBNET_BGP4_NOTIFICATION_H)
HL_CDP = 
INT2FIX(LIBNET_CDP_H)
HL_DHCPV4 = 
INT2FIX(LIBNET_DHCPV4_H)
HL_UDP_DNSV4 = 
INT2FIX(LIBNET_UDP_DNSV4_H)
HL_TCP_DNSV4 = 
INT2FIX(LIBNET_TCP_DNSV4_H)
HL_ETH = 
INT2FIX(LIBNET_ETH_H)
HL_FDDI = 
INT2FIX(LIBNET_FDDI_H)
HL_ICMPV4 = 
INT2FIX(LIBNET_ICMPV4_H)
HL_ICMPV4_ECHO = 
INT2FIX(LIBNET_ICMPV4_ECHO_H)
HL_ICMPV4_MASK = 
INT2FIX(LIBNET_ICMPV4_MASK_H)
HL_ICMPV4_UNREACH = 
INT2FIX(LIBNET_ICMPV4_UNREACH_H)
HL_ICMPV4_TIMXCEED = 
INT2FIX(LIBNET_ICMPV4_TIMXCEED_H)
HL_ICMPV4_REDIRECT = 
INT2FIX(LIBNET_ICMPV4_REDIRECT_H)
HL_ICMPV4_TS = 
INT2FIX(LIBNET_ICMPV4_TS_H)
HL_ICMPV6 = 
INT2FIX(LIBNET_ICMPV6_H)
HL_IGMP = 
INT2FIX(LIBNET_IGMP_H)
HL_IPV4 = 
INT2FIX(LIBNET_IPV4_H)
HL_IPV6 = 
INT2FIX(LIBNET_IPV6_H)
HL_IPV6_FRAG = 
INT2FIX(LIBNET_IPV6_FRAG_H)
HL_IPV6_ROUTING = 
INT2FIX(LIBNET_IPV6_ROUTING_H)
HL_IPV6_DESTOPTS = 
INT2FIX(LIBNET_IPV6_DESTOPTS_H)
HL_IPV6_HBHOPTS = 
INT2FIX(LIBNET_IPV6_HBHOPTS_H)
HL_IPSEC_ESP_HDR = 
INT2FIX(LIBNET_IPSEC_ESP_HDR_H)
HL_IPSEC_ESP_FTR = 
INT2FIX(LIBNET_IPSEC_ESP_FTR_H)
HL_IPSEC_AH = 
INT2FIX(LIBNET_IPSEC_AH_H)
HL_ISL = 
INT2FIX(LIBNET_ISL_H)
HL_GRE = 
INT2FIX(LIBNET_GRE_H)
HL_GRE_SRE = 
INT2FIX(LIBNET_GRE_SRE_H)
HL_MPLS = 
INT2FIX(LIBNET_MPLS_H)
HL_OSPF = 
INT2FIX(LIBNET_OSPF_H)
HL_OSPF_HELLO = 
INT2FIX(LIBNET_OSPF_HELLO_H)
HL_OSPF_DBD = 
INT2FIX(LIBNET_OSPF_DBD_H)
HL_OSPF_LSR = 
INT2FIX(LIBNET_OSPF_LSR_H)
HL_OSPF_LSU = 
INT2FIX(LIBNET_OSPF_LSU_H)
HL_OSPF_LSA = 
INT2FIX(LIBNET_OSPF_LSA_H)
HL_OSPF_AUTH = 
INT2FIX(LIBNET_OSPF_AUTH_H)
HL_OSPF_CKSUM = 
INT2FIX(LIBNET_OSPF_CKSUM)
HL_OSPF_LS_RTR = 
INT2FIX(LIBNET_OSPF_LS_RTR_H)
HL_OSPF_LS_NET = 
INT2FIX(LIBNET_OSPF_LS_NET_H)
HL_OSPF_LS_SUM = 
INT2FIX(LIBNET_OSPF_LS_SUM_H)
HL_OSPF_LS_AS_EXT = 
INT2FIX(LIBNET_OSPF_LS_AS_EXT_H)
HL_NTP = 
INT2FIX(LIBNET_NTP_H)
HL_RIP = 
INT2FIX(LIBNET_RIP_H)
HL_RPC_CALL = 
INT2FIX(LIBNET_RPC_CALL_H)
HL_RPC_CALL_TCP = 
INT2FIX(LIBNET_RPC_CALL_TCP_H)
HL_SEBEK = 
INT2FIX(LIBNET_SEBEK_H)
HL_STP_CONF = 
INT2FIX(LIBNET_STP_CONF_H)
HL_STP_TCN = 
INT2FIX(LIBNET_STP_TCN_H)
HL_TOKEN_RING = 
INT2FIX(LIBNET_TOKEN_RING_H)
HL_TCP = 
INT2FIX(LIBNET_TCP_H)
HL_UDP = 
INT2FIX(LIBNET_UDP_H)
HL_VRRP = 
INT2FIX(LIBNET_VRRP_H)
IPPROTO_IP = 
INT2FIX(IPPROTO_IP)
IPPROTO_HOPOPTS = 
INT2FIX(IPPROTO_HOPOPTS)
IPPROTO_ICMP = 
INT2FIX(IPPROTO_ICMP)
IPPROTO_IGMP = 
INT2FIX(IPPROTO_IGMP)
IPPROTO_GGP = 
INT2FIX(IPPROTO_GGP)
IPPROTO_ENCAP = 
INT2FIX(IPPROTO_ENCAP)
IPPROTO_TCP = 
INT2FIX(IPPROTO_TCP)
IPPROTO_EGP = 
INT2FIX(IPPROTO_EGP)
IPPROTO_PUP = 
INT2FIX(IPPROTO_PUP)
IPPROTO_UDP = 
INT2FIX(IPPROTO_UDP)
IPPROTO_IDP = 
INT2FIX(IPPROTO_IDP)
IPPROTO_IPV6 = 
INT2FIX(IPPROTO_IPV6)
IPPROTO_ROUTING = 
INT2FIX(IPPROTO_ROUTING)
IPPROTO_FRAGMENT = 
INT2FIX(IPPROTO_FRAGMENT)
IPPROTO_RSVP = 
INT2FIX(IPPROTO_RSVP)
IPPROTO_ESP = 
INT2FIX(IPPROTO_ESP)
IPPROTO_AH = 
INT2FIX(IPPROTO_AH)
IPPROTO_ICMPV6 = 
INT2FIX(IPPROTO_ICMPV6)
IPPROTO_NONE = 
INT2FIX(IPPROTO_NONE)
IPPROTO_DSTOPTS = 
INT2FIX(IPPROTO_DSTOPTS)
IPPROTO_HELLO = 
INT2FIX(IPPROTO_HELLO)
IPPROTO_ND = 
INT2FIX(IPPROTO_ND)
IPPROTO_EON = 
INT2FIX(IPPROTO_EON)
IPPROTO_PIM = 
INT2FIX(IPPROTO_PIM)
IPPROTO_SCTP = 
INT2FIX(IPPROTO_SCTP)
IPPROTO_RAW = 
INT2FIX(IPPROTO_RAW)
IPPROTO_MAX = 
INT2FIX(IPPROTO_MAX)

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#injection_type ⇒ Object (readonly)

Returns the value of attribute injection_type.



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# File 'lib/libnet4r/libnet.rb', line 3

def injection_type
  @injection_type
end

Class Method Details

.addr2name4(addr, do_dns_lookup = true) ⇒ Object

Takes a network byte ordered IPv4 address and returns a string containing

either the canonical DNS name (if it has one) or a dotted decimal
respresentation of the IP address.  This may incur a DNS lookup if the
+do_dns_lookup+ parameter is set to true.  If the +do_dns_lookup+
parameter is set to false, no DNS lookup will be performed and the dotted
decimal representation of the IP address will be returned.



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# File 'ext/libnet.c', line 123

static VALUE net_s_addr2name4(int argc, VALUE *argv, VALUE self)
{
    VALUE      addr_v, use_name_v, name_v;
    u_int32_t  addr;
    u_int8_t   use_name = LIBNET_RESOLVE;
    char      *name = NULL;

    rb_scan_args(argc, argv, "11", &addr_v, &use_name_v);

    addr = NUM2ULONG(addr_v);

    addr = htonl(addr);

    if (!NIL_P(use_name_v) && use_name_v == Qfalse) {
        use_name = LIBNET_DONT_RESOLVE;
    }

    name = libnet_addr2name4(addr, use_name);

    name_v = rb_str_new2(name);

    /* don't free the returned name here as its stored in a static buffer by
     * libnet */

    return name_v;
}

.addr2name6(addr, do_dns_lookup = true) ⇒ printable IPv6 string

Takes a 16 byte IPv6 address and returns either the canonical DNS name (if it has one) or a printable representation of the address.

Returns:

  • (printable IPv6 string) 


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# File 'ext/libnet.c', line 156

static VALUE net_s_addr2name6(int argc, VALUE *argv, VALUE self)
{
    VALUE      addr_v, use_name_v, name_v;
    struct libnet_in6_addr addr;
    u_int8_t   use_name = LIBNET_RESOLVE;
    char       name[100];

    rb_scan_args(argc, argv, "11", &addr_v, &use_name_v);

    if (RSTRING(addr_v)->len != 16) {
      rb_raise(rb_eArgError, "invalid IPv6 address");
    }

    memcpy(addr.libnet_s6_addr, RSTRING(addr_v)->ptr, sizeof(addr.libnet_s6_addr));

    if (!NIL_P(use_name_v) && use_name_v == Qfalse) {
        use_name = LIBNET_DONT_RESOLVE;
    }

    libnet_addr2name6_r(addr, use_name, name, sizeof(name));

    name_v = rb_str_new2(name);

    return name_v;
}

.hex_aton(string) ⇒ String

Takes a colon separated hexidecimal address and returns a byte string suitable for use in a protocol builder method.

Returns:

  • (String) 


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# File 'ext/libnet.c', line 188

static VALUE net_s_hex_aton(VALUE self, VALUE str)
{
    u_int8_t *rv;
    int       len;
    VALUE     s;

    rv = libnet_hex_aton((int8_t *)StringValuePtr(str), &len);

    if (rv == NULL) {
        rb_raise(rb_eArgError, "could not convert input string");
    }

    s = rb_str_new((char *)rv, len);

    free(rv);

    return s;
}

.hexdump(bytes) ⇒ Object

:call-seq:

Libnet.hexdump(bytes) # -> string

Returns a string containing a hexdump of the given byte string.

Example:

Libnet.hexump("foobar")

produces the following string:

0x00000000: 666f6f62 6172



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# File 'lib/libnet4r/libnet.rb', line 16

def self.hexdump(bytes)
  offset = 0
  i      = 0
  dump   = "0x00000000: "

  bytes.each_byte do |b|
    if i != 0
      if i % 16 == 0
        offset += 16
        dump += sprintf("\n0x%08x: ", offset)
      elsif i % 4 == 0
        dump += " "
      end
    end

    dump += sprintf("%02x", b)

    i += 1
  end

  dump += "\n"
end

.ipv4_aton(string) ⇒ Integer

Takes a dotted-decimal representation of an IPv4 address and returns a 4 byte integer suitable for use in a header builder method.

Returns:

  • (Integer) 


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# File 'ext/libnet.c', line 214

static VALUE net_s_ipv4_aton(VALUE self, VALUE str)
{
  char          *ip_s;
  int            len = RSTRING(str)->len;
  unsigned long  ipv4;
  VALUE          r;

  ip_s = malloc(len + 1);

  memcpy(ip_s, RSTRING(str)->ptr, len);
  ip_s[len] = '\0';

  if (inet_pton(AF_INET, ip_s, &ipv4) == 1) {
    ipv4 = htonl(ipv4);
    r = ULONG2NUM(ipv4);
  }
  else {
    free(ip_s);
    rb_raise(rb_eArgError, "invalid IPv4 address: %s\n", ip_s);
  }

  free(ip_s);

  return r;
}

.ipv4_ntoa(integer) ⇒ String

Takes a network formated IPv4 address and converts it to its dotted-decimal string representation.

Returns:

  • (String) 


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# File 'ext/libnet.c', line 277

static VALUE net_s_ipv4_ntoa(VALUE self, VALUE integer)
{
  unsigned long ipv4 = NUM2ULONG(integer);
  char          pbuf[100];
  VALUE         r;

  ipv4 = htonl(ipv4);

  if (inet_ntop(AF_INET, &ipv4, pbuf, sizeof(pbuf))) {
    r = rb_str_new2(pbuf);
  }
  else {
    rb_raise(rb_eArgError,
        "could not convert integer value %#x to a printable IPv4 string",
        ipv4);
  }

  return r;
}

.ipv6_aton(string) ⇒ Integer

Takes a string representation of an IPv6 address and returns a 16 byte string suitable for use in a header builder method.

Returns:

  • (Integer) 


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# File 'ext/libnet.c', line 246

static VALUE net_s_ipv6_aton(VALUE self, VALUE str)
{
  char          *ip_s;
  int            len = RSTRING(str)->len;
  unsigned char  ipv6[16];
  VALUE          r;

  ip_s = malloc(len + 1);

  memcpy(ip_s, RSTRING(str)->ptr, len);
  ip_s[len] = '\0';

  if (inet_pton(AF_INET6, ip_s, ipv6) == 1) {
    r = rb_str_new(ipv6, sizeof(ipv6));
  }
  else {
    free(ip_s);
    rb_raise(rb_eArgError, "invalid IPv6 address: %s\n", ip_s);
  }

  free(ip_s);

  return r;
}

.ipv6_ntoa(string) ⇒ String

Takes a network formated IPv6 address and converts it to its printable format.

Returns:

  • (String) 


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# File 'ext/libnet.c', line 303

static VALUE net_s_ipv6_ntoa(VALUE self, VALUE str)
{
  char         *ip_s;
  int           len = RSTRING(str)->len;
  char          pbuf[100];
  VALUE         r;

  if (len != 16) {
    rb_raise(rb_eArgError, "invalid IPv6 address");
  }

  ip_s = malloc(len + 1);

  memcpy(ip_s, RSTRING(str)->ptr, len);
  ip_s[len] = '\0';

  if (inet_ntop(AF_INET6, ip_s, pbuf, sizeof(pbuf))) {
    r = rb_str_new2(pbuf);
  }
  else {
    rb_raise(rb_eArgError,
        "could not convert IPv6 address to a printable string");
  }

  return r;
}

.new(injection_type = :raw4, device = nil) ⇒ a new Libnet object

Creates a new Libnet object. The injection_type parameter defines

how the constructed packet get injected into the network.

If +injection_type+ is <tt>:link</tt>, the packet gets injected at the data
link layer (which provides more granular control over the IP layer).  If
+injection_type+ is <tt>:link</tt> and +device+ is not +nil+, Libnet
attempts to use the specified network device for packet injection.  The
+device+ parameter is either a canonical string that references the device
(such as "eth0" for a 100MB Ethernet card on Linux or "fxp0" for a 100MB
Ethernet card on OpenBSD) or the dotted decimal representation of the
device's IP address (e.g. 192.168.0.1).  If +device+ is +nil+, Libnet
attempts to find a suitable device to use.

If +injection_type+ is <tt>:raw4</tt>, the packet gets injected using a raw
socket interface.

Returns:



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# File 'ext/libnet.c', line 37

static VALUE net_s_new(int argc, VALUE *argv, VALUE self)
{
    libnet_t *l;
    VALUE     obj;
    char      errbuf[LIBNET_ERRBUF_SIZE];
    int       inj_type = LIBNET_RAW4_ADV;
    char     *inj_str = NULL;
    size_t    inj_str_len = 0;
    char     *dev_str = NULL;

    /* get the injection type */
    if (argc > 0) {
        switch (TYPE(argv[0])) {
            case T_STRING:
                inj_str     = RSTRING(argv[0])->ptr;
                inj_str_len = RSTRING(argv[0])->len;
                break;
            case T_SYMBOL:
                inj_str     = rb_id2name(SYM2ID(argv[0]));
                inj_str_len = strlen(inj_str);
                break;
            default:
                rb_raise(rb_eTypeError,
                        "invalid type, expecting a String or Symbol");
        }

        if (strncasecmp("raw", inj_str, inj_str_len) == 0 ||
            strncasecmp("raw4", inj_str, inj_str_len) == 0) {
            inj_type = LIBNET_RAW4_ADV;
        }
        else if (strncasecmp("raw6", inj_str, inj_str_len) == 0) {
            inj_type = LIBNET_RAW6_ADV;
        }
        else if (strncasecmp("link", inj_str, inj_str_len) == 0) {
            inj_type = LIBNET_LINK_ADV;
        }
        else {
            rb_raise(rb_eArgError,
                    "%s is not a valid initialization type, should be one of: 'raw4', 'raw6', or 'link'",
                    inj_str);
        }
    }

    /* get the device string */
    if (argc > 1) {
        dev_str = StringValuePtr(argv[1]);
    }

    l = libnet_init(inj_type, dev_str, errbuf);

    if (l == NULL) {
        rb_raise(rb_eRuntimeError, errbuf);
    }

    obj = Data_Wrap_Struct(self, NULL, libnet_destroy, l);

    /* set the injection type attribute */
    switch (inj_type) {
        case LIBNET_RAW4_ADV:
            rb_iv_set(obj, "@injection_type", ID2SYM(rb_intern("raw4")));
            break;
        case LIBNET_RAW6_ADV:
            rb_iv_set(obj, "@injection_type", ID2SYM(rb_intern("raw6")));
            break;
        case LIBNET_LINK_ADV:
            rb_iv_set(obj, "@injection_type", ID2SYM(rb_intern("link")));
            break;
        default:
            rb_bug("BUG: %d is an invalid injection type (this should not happen)",
                    inj_type); 
    }


    return obj;
}

Instance Method Details

#build_arp(*args) ⇒ Object 



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# File 'ext/libnet_arp.c', line 75

static VALUE net_build_arp(int argc, VALUE *argv, VALUE self)
{
    libnet_t      *l;
    VALUE          arp_obj, v;
    u_int16_t      hrd, pro, op;
    u_int8_t       hln, pln;
    VALUE          sha, spa, tha, tpa; 
    char          *payload   = NULL;
    u_int32_t      payload_s = 0;
    VALUE          ptag_obj;
    libnet_ptag_t  ptag = 0;

    rb_scan_args(argc, argv, "01", &arp_obj);

    Data_Get_Struct(self, libnet_t, l);

    if (NIL_P(arp_obj)) {
        arp_obj = rb_class_new_instance(0, NULL, cARP);
        rb_yield(arp_obj);
    }

    /* check that all required fields are set */
    rb_funcall(arp_obj, rb_intern("check_packable"), 0);

    v   = rb_funcall(arp_obj, rb_intern("htype"), 0);
    hrd = NUM2UINT(v);
    v   = rb_funcall(arp_obj, rb_intern("protocol"), 0);
    pro = NUM2UINT(v);
    v   = rb_funcall(arp_obj, rb_intern("hlen"), 0);
    hln = NUM2UINT(v);
    v   = rb_funcall(arp_obj, rb_intern("plen"), 0);
    pln = NUM2UINT(v);
    v   = rb_funcall(arp_obj, rb_intern("operation"), 0);
    op  = NUM2UINT(v);
    v   = rb_funcall(arp_obj, rb_intern("sender_haddr"), 0);
    sha = StringValue(v);
    v   = rb_funcall(arp_obj, rb_intern("sender_paddr"), 0);
    spa = StringValue(v);
    v   = rb_funcall(arp_obj, rb_intern("target_haddr"), 0);
    tha = StringValue(v);
    v   = rb_funcall(arp_obj, rb_intern("target_paddr"), 0);
    tpa = StringValue(v);

    /* get the payload */
    if ((v = rb_funcall(arp_obj, rb_intern("payload"), 0)) != Qnil) {
        v         = StringValue(v);
        payload   = RSTRING(v)->ptr;
        payload_s = RSTRING(v)->len;
    }

    ptag_obj = rb_iv_get(arp_obj, "@ptag");

    if (!NIL_P(ptag_obj)) {
        ptag = NUM2LONG(ptag_obj);
    }

    ptag = libnet_build_arp(hrd, pro, hln, pln, op, RSTRING(sha)->ptr,
            RSTRING(spa)->ptr, RSTRING(tha)->ptr, RSTRING(tpa)->ptr,
            payload, payload_s, l, ptag);
            
    if (ptag == -1) {
        rb_raise(rb_eRuntimeError, libnet_geterror(l));
    }

    rb_iv_set(arp_obj, "@ptag", LONG2NUM(ptag));

    return arp_obj;
}

#build_ethernet(*args) ⇒ Object 



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# File 'ext/libnet_ethernet.c', line 50

static VALUE net_build_ethernet(int argc, VALUE *argv, VALUE self)
{
    libnet_t      *l;
    VALUE          eth, v;
    u_int8_t      *dst = NULL;
    u_int8_t      *src = NULL;
    u_int16_t      type;
    char          *payload = NULL;
    u_int32_t      payload_s = 0;
    VALUE          ptag_obj;
    libnet_ptag_t  ptag = 0;

    rb_scan_args(argc, argv, "01", &eth);

    Data_Get_Struct(self, libnet_t, l);

    if (NIL_P(eth)) {
        eth = rb_class_new_instance(0, NULL, rb_const_get(cLibnet, rb_intern("Ethernet")));
        rb_yield(eth);
    }

    /* check that all required fields are set */
    rb_funcall(eth, rb_intern("check_packable"), 0);

    /* required parameters */
    v    = rb_funcall(eth, rb_intern("dst"), 0);
    dst  = (u_int8_t *)StringValuePtr(v);
    v    = rb_funcall(eth, rb_intern("type"), 0);
    type = NUM2UINT(v);

    /* optional parameters */
    v   = rb_funcall(eth, rb_intern("src"), 0);
    src = (u_int8_t *)StringValuePtr(v);

    if ((v = rb_funcall(eth, rb_intern("payload"), 0)) != Qnil) {
        v         = StringValue(v);
        payload   = RSTRING(v)->ptr;
        payload_s = RSTRING(v)->len;
    }

    ptag_obj = rb_iv_get(eth, "@ptag");

    if (!NIL_P(ptag_obj)) {
        ptag = NUM2LONG(ptag_obj);
    }

    ptag = libnet_build_ethernet(dst, src, type, (u_int8_t *)payload,
        payload_s, l, ptag);

    if (ptag == -1) {
        rb_raise(rb_eRuntimeError, libnet_geterror(l));
    }

    rb_iv_set(eth, "@ptag", LONG2NUM(ptag));

    return eth;
}

#build_ipv4(*args) ⇒ Object 



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# File 'ext/libnet_ipv4.c', line 64

static VALUE net_build_ipv4(int argc, VALUE *argv, VALUE self)
{
    libnet_t      *l;
    VALUE          ipv4, v;
    u_int8_t       tos = 0, ttl = 0, prot = 0;
    u_int16_t      len = 0, id = 0, frag = 0, sum = 0;
    u_int32_t      src = 0, dst = 0;
    char          *payload = NULL;
    u_int32_t      payload_s = 0;
    VALUE          ptag_obj;
    libnet_ptag_t  ptag = 0;

    rb_scan_args(argc, argv, "01", &ipv4);

    Data_Get_Struct(self, libnet_t, l);

    if (NIL_P(ipv4)) {
        ipv4 = rb_class_new_instance(0, NULL, rb_const_get(cLibnet, rb_intern("IPv4")));
        rb_yield(ipv4);
    }

    /* check that all required fields are set */
    rb_funcall(ipv4, rb_intern("check_packable"), 0);

    v    = rb_funcall(ipv4, rb_intern("length"), 0);
    len  = NUM2UINT(v);
    v    = rb_funcall(ipv4, rb_intern("protocol"), 0);
    prot = NUM2UINT(v);
    v    = rb_funcall(ipv4, rb_intern("tos"), 0);
    tos  = NUM2UINT(v);
    v    = rb_funcall(ipv4, rb_intern("id"), 0);
    id   = NUM2UINT(v);
    v    = rb_funcall(ipv4, rb_intern("frag_off"), 0);
    frag = NUM2UINT(v);
    v    = rb_funcall(ipv4, rb_intern("ttl"), 0);
    ttl  = NUM2UINT(v);
    v    = rb_funcall(ipv4, rb_intern("checksum"), 0);
    sum  = NUM2UINT(v);
    v    = rb_funcall(ipv4, rb_intern("src_ip"), 0);
    src  = htonl(NUM2ULONG(v));
    v    = rb_funcall(ipv4, rb_intern("dst_ip"), 0);
    dst  = htonl(NUM2ULONG(v));

    /* payload is optional */
    if ((v = rb_funcall(ipv4, rb_intern("payload"), 0)) != Qnil) {
        v         = StringValue(v);
        payload   = RSTRING(v)->ptr;
        payload_s = RSTRING(v)->len;
    }

    ptag_obj = rb_iv_get(ipv4, "@ptag");

    if (!NIL_P(ptag_obj)) {
        ptag = NUM2LONG(ptag_obj);
    }

    ptag = libnet_build_ipv4(len, tos, id, frag, ttl, prot, sum, src, dst,
            (u_int8_t *)payload, payload_s, l, ptag);

    if (ptag == -1) {
        rb_raise(rb_eRuntimeError, libnet_geterror(l));
    }

    rb_iv_set(ipv4, "@ptag", LONG2NUM(ptag));

    return ipv4;
}

#build_ipv6(*args) ⇒ Object 



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# File 'ext/libnet_ipv6.c', line 63

static VALUE net_build_ipv6(int argc, VALUE *argv, VALUE self)
{
    libnet_t               *l;
    VALUE                   ipv6, v;
    u_int8_t                tc, nh, hl;
    u_int16_t               len;
    u_int32_t               fl;
    struct libnet_in6_addr  src, dst;
    u_int8_t               *payload = NULL;
    u_int32_t               payload_s = 0;
    VALUE                   ptag_obj;
    libnet_ptag_t           ptag = 0;

    rb_scan_args(argc, argv, "01", &ipv6);

    Data_Get_Struct(self, libnet_t, l);

    if (NIL_P(ipv6)) {
        ipv6 = rb_class_new_instance(0, NULL, rb_const_get(cLibnet, rb_intern("IPv6")));
        rb_yield(ipv6);
    }

    /* check that all required fields are set */
    rb_funcall(ipv6, rb_intern("check_packable"), 0);

    v    = rb_funcall(ipv6, rb_intern("traffic_class"), 0);
    tc   = NUM2UINT(v);
    v    = rb_funcall(ipv6, rb_intern("flow_label"), 0);
    fl   = NUM2ULONG(v);
    v    = rb_funcall(ipv6, rb_intern("length"), 0);
    len  = NUM2ULONG(v);
    v    = rb_funcall(ipv6, rb_intern("next_header"), 0);
    nh   = NUM2ULONG(v);
    v    = rb_funcall(ipv6, rb_intern("hop_limit"), 0);
    hl   = NUM2ULONG(v);
    v    = rb_funcall(ipv6, rb_intern("src_ip"), 0);
    v    = StringValue(v);
    memcpy(&src, RSTRING(v)->ptr, sizeof(src)); 
    v    = rb_funcall(ipv6, rb_intern("dst_ip"), 0);
    v    = StringValue(v);
    memcpy(&dst, RSTRING(v)->ptr, sizeof(dst)); 

    /* payload is optional */
    if ((v = rb_funcall(ipv6, rb_intern("payload"), 0)) != Qnil) {
        v         = StringValue(v);
        payload   = RSTRING(v)->ptr;
        payload_s = RSTRING(v)->len;
    }

    ptag_obj = rb_iv_get(ipv6, "@ptag");

    if (!NIL_P(ptag_obj)) {
        ptag = NUM2LONG(ptag_obj);
    }

    ptag = libnet_build_ipv6(tc, fl, len, nh, hl, src, dst, (u_int8_t *)payload,
            payload_s, l, ptag);

    if (ptag == -1) {
        rb_raise(rb_eRuntimeError, libnet_geterror(l));
    }

    rb_iv_set(ipv6, "@ptag", LONG2NUM(ptag));

    return ipv6;
}

#build_tcp(*args) ⇒ Object 



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# File 'ext/libnet_tcp.c', line 63

static VALUE net_build_tcp(int argc, VALUE *argv, VALUE self)
{
    libnet_t      *l;
    VALUE          tcp, v;
    u_int16_t      sp, dp;
    u_int32_t      seq, ack;
    u_int8_t       control;
    u_int16_t      win, sum, urg;
    char          *payload   = NULL;
    u_int32_t      payload_s = 0;
    VALUE          ptag_obj;
    libnet_ptag_t  ptag = 0;

    rb_scan_args(argc, argv, "01", &tcp);

    Data_Get_Struct(self, libnet_t, l);

    if (NIL_P(tcp)) {
        tcp = rb_class_new_instance(0, NULL, rb_const_get(cLibnet, rb_intern("TCP")));
        rb_yield(tcp);
    }

    /* check that all required fields are set */
    rb_funcall(tcp, rb_intern("check_packable"), 0);

    v       = rb_funcall(tcp, rb_intern("src_port"), 0);
    sp      = NUM2UINT(v);
    v       = rb_funcall(tcp, rb_intern("dst_port"), 0);
    dp      = NUM2UINT(v);
    v       = rb_funcall(tcp, rb_intern("seq"), 0);
    seq     = NUM2ULONG(v);
    v       = rb_funcall(tcp, rb_intern("ack"), 0);
    ack     = NUM2ULONG(v);
    v       = rb_funcall(tcp, rb_intern("control"), 0);
    control = NUM2UINT(v);
    v       = rb_funcall(tcp, rb_intern("window"), 0);
    win     = NUM2UINT(v);
    v       = rb_funcall(tcp, rb_intern("checksum"), 0);
    sum     = NUM2UINT(v);
    v       = rb_funcall(tcp, rb_intern("urgent"), 0);
    urg     = NUM2UINT(v);

    /* get the payload */
    if ((v = rb_funcall(tcp, rb_intern("payload"), 0)) != Qnil) {
        v         = StringValue(v);
        payload   = RSTRING(v)->ptr;
        payload_s = RSTRING(v)->len;
    }

    ptag_obj = rb_iv_get(tcp, "@ptag");

    if (!NIL_P(ptag_obj)) {
        ptag = NUM2LONG(ptag_obj);
    }

    ptag = libnet_build_tcp(sp, dp, seq, ack, control, win, sum, urg,
        LIBNET_TCP_H + payload_s, (u_int8_t *)payload, payload_s, l, ptag);

    if (ptag == -1) {
        rb_raise(rb_eRuntimeError, libnet_geterror(l));
    }

    rb_iv_set(tcp, "@ptag", LONG2NUM(ptag));

    return tcp;
}

#build_udp(*args) ⇒ Object 



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# File 'ext/libnet_udp.c', line 48

static VALUE net_build_udp(int argc, VALUE *argv, VALUE self)
{
    libnet_t      *l;
    VALUE          udp, v;
    u_int16_t      sp, dp, len, sum;
    char          *payload   = NULL;
    u_int32_t      payload_s = 0;
    VALUE          ptag_obj;
    libnet_ptag_t  ptag = 0;

    rb_scan_args(argc, argv, "01", &udp);

    Data_Get_Struct(self, libnet_t, l);

    if (NIL_P(udp)) {
        udp = rb_class_new_instance(0, NULL, rb_const_get(cLibnet, rb_intern("UDP")));
        rb_yield(udp);
    }

    /* check that all required fields are set */
    rb_funcall(udp, rb_intern("check_packable"), 0);

    v   = rb_funcall(udp, rb_intern("src_port"), 0);
    sp  = NUM2UINT(v);
    v   = rb_funcall(udp, rb_intern("dst_port"), 0);
    dp  = NUM2UINT(v);
    v   = rb_funcall(udp, rb_intern("length"), 0);
    len = NUM2UINT(v);
    v   = rb_funcall(udp, rb_intern("checksum"), 0);
    sum = NUM2UINT(v);

    /* get the payload */
    if ((v = rb_funcall(udp, rb_intern("payload"), 0)) != Qnil) {
        v         = StringValue(v);
        payload   = RSTRING(v)->ptr;
        payload_s = RSTRING(v)->len;
    }

    ptag_obj = rb_iv_get(udp, "@ptag");

    if (!NIL_P(ptag_obj)) {
        ptag = NUM2LONG(ptag_obj);
    }

    ptag = libnet_build_udp(sp, dp, len, sum, (u_int8_t *)payload,
        payload_s, l, ptag);

    if (ptag == -1) {
        rb_raise(rb_eRuntimeError, libnet_geterror(l));
    }

    rb_iv_set(udp, "@ptag", LONG2NUM(ptag));

    return udp;
}

#build_vlan(*args) ⇒ Object 



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# File 'ext/libnet_vlan.c', line 55

static VALUE net_build_vlan(int argc, VALUE *argv, VALUE self)
{
    libnet_t      *l;
    VALUE          vlan_obj, v;
    u_int8_t      *dst = NULL;
    u_int8_t      *src = NULL;
    u_int16_t      tpi;
    u_int8_t       priority;
    u_int8_t       cfi;
    u_int16_t      vlan_id;
    u_int16_t      len_proto;
    char          *payload = NULL;
    u_int32_t      payload_s = 0;
    VALUE          ptag_obj;
    libnet_ptag_t  ptag = 0;

    rb_scan_args(argc, argv, "01", &vlan_obj);

    Data_Get_Struct(self, libnet_t, l);

    if (NIL_P(vlan_obj)) {
        vlan_obj = rb_class_new_instance(0, NULL, rb_const_get(cLibnet, rb_intern("VLAN")));
        rb_yield(vlan_obj);
    }

    /* check that all required fields are set */
    rb_funcall(vlan_obj, rb_intern("check_packable"), 0);

    /* required parameters */
    v         = rb_funcall(vlan_obj, rb_intern("dst"), 0);
    dst       = (u_int8_t *)StringValuePtr(v);
    v         = rb_funcall(vlan_obj, rb_intern("src"), 0);
    src       = (u_int8_t *)StringValuePtr(v);
    v         = rb_funcall(vlan_obj, rb_intern("tpi"), 0);
    tpi       = NUM2UINT(v);
    v         = rb_funcall(vlan_obj, rb_intern("priority"), 0);
    priority  = NUM2UINT(v);
    v         = rb_funcall(vlan_obj, rb_intern("cfi"), 0);
    cfi       = NUM2UINT(v);
    v         = rb_funcall(vlan_obj, rb_intern("id"), 0);
    vlan_id   = NUM2UINT(v);
    v         = rb_funcall(vlan_obj, rb_intern("len"), 0);
    len_proto = NUM2UINT(v);

    /* optional parameters */
    if ((v = rb_funcall(vlan_obj, rb_intern("payload"), 0)) != Qnil) {
        v         = StringValue(v);
        payload   = RSTRING(v)->ptr;
        payload_s = RSTRING(v)->len;
    }

    ptag_obj = rb_iv_get(vlan_obj, "@ptag");

    if (!NIL_P(ptag_obj)) {
        ptag = NUM2LONG(ptag_obj);
    }

    ptag = libnet_build_802_1q(dst, src, tpi, priority, cfi, vlan_id, len_proto,
            (u_int8_t *)payload, payload_s, l, ptag);

    if (ptag == -1) {
        rb_raise(rb_eRuntimeError, libnet_geterror(l));
    }

    rb_iv_set(vlan_obj, "@ptag", LONG2NUM(ptag));

    return vlan_obj;
}

#clear ⇒ Object

Clears the current packet inside the Libnet object. Should be called when the programmer wants to send a completely new packet of a different type using the same Libnet object.



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# File 'ext/libnet.c', line 470

static VALUE net_clear(VALUE self)
{
    libnet_t  *l;

    Data_Get_Struct(self, libnet_t, l);

    libnet_clear_packet(l);

    return Qnil;
}

#cull_packet ⇒ Object

Yanks a prebuilt, wire-ready packet from the Libnet object.



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# File 'ext/libnet.c', line 427

static VALUE net_pack(VALUE self)
{
    libnet_t  *l;
    u_int8_t  *packet;
    u_int32_t  packet_s;
    VALUE      str;

    Data_Get_Struct(self, libnet_t, l);

    if (libnet_pblock_coalesce(l, &packet, &packet_s) == -1) {
        rb_raise(rb_eRuntimeError, libnet_geterror(l));
    }

    str = rb_str_new((char *)packet, packet_s);

    libnet_adv_free_packet(l, packet);

    return str;
}

#device ⇒ Object

Returns the canonical name of the device used for packet injection.



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# File 'ext/libnet.c', line 335

static VALUE net_get_device(VALUE self)
{
    libnet_t *l;
    char     *dev;

    Data_Get_Struct(self, libnet_t, l);

    dev = (char *)libnet_getdevice(l);

    if (dev == NULL) {
        dev = "";
    }

    return rb_str_new2(dev);
}

#dump ⇒ Object

Prints the contents of the Libnet object to STDOUT.



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# File 'ext/libnet.c', line 452

static VALUE net_dump(VALUE self)
{
    libnet_t  *l;

    Data_Get_Struct(self, libnet_t, l);

    libnet_diag_dump_context(l);

    return Qnil;
}

#hwaddr ⇒ Object

Returns the MAC address for the device the Libnet object was initialized with. If the Libnet object was initialized without a device, the method will attempt to find one. If the method fails to find a device, a RuntimeError will be raised.



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# File 'ext/libnet.c', line 489

static VALUE net_hwaddr(VALUE self)
{
    libnet_t                  *l;
    struct  libnet_ether_addr *eth;
    int                        i;
    char                       eth_s[18];
    char                       byte_s[3];

    Data_Get_Struct(self, libnet_t, l);

    eth = libnet_get_hwaddr(l);

    if (eth == NULL) {
        rb_raise(rb_eRuntimeError, libnet_geterror(l));
    }

    memset(eth_s, 0, sizeof(eth_s));

    for (i = 0; i < 6; i++) {
        snprintf(byte_s, sizeof(byte_s), "%02x", eth->ether_addr_octet[i]);
        strcat(eth_s, byte_s);

        if (i != 5) {
            strcat(eth_s, ":");
        }
    }

    return rb_str_new2(eth_s);
}

#pack ⇒ Object

Yanks a prebuilt, wire-ready packet from the Libnet object.



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# File 'ext/libnet.c', line 427

static VALUE net_pack(VALUE self)
{
    libnet_t  *l;
    u_int8_t  *packet;
    u_int32_t  packet_s;
    VALUE      str;

    Data_Get_Struct(self, libnet_t, l);

    if (libnet_pblock_coalesce(l, &packet, &packet_s) == -1) {
        rb_raise(rb_eRuntimeError, libnet_geterror(l));
    }

    str = rb_str_new((char *)packet, packet_s);

    libnet_adv_free_packet(l, packet);

    return str;
}

#write ⇒ Object

Writes a prebuilt packet to the network. The method assumes that a packet has been constructed inside the Libnet object via one or more Libnet#build_* methods and is ready to go. Depending on how this Libnet object was initialized, the method will write the packet to the wire either via the raw or link layer interface.

Note: It is necessary for the UID or EUID of the process running this method to be 0.



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# File 'ext/libnet.c', line 363

static VALUE net_write(VALUE self)
{
    libnet_t *l;
    int       num_bytes;

    Data_Get_Struct(self, libnet_t, l);

    num_bytes = libnet_write(l);

    if (num_bytes == -1) {
        rb_raise(rb_eRuntimeError, libnet_geterror(l));
    }

    return INT2NUM(num_bytes);
}

#write_bytes(string) ⇒ Object

Writes a packet to the wire. This method is usedful to write a packet that has been constructed by hand or to write a packet that has been returned from Libnet#pack.

Note: It is necessary for the UID or EUID of the process running this method to be 0.



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# File 'ext/libnet.c', line 389

static VALUE net_write_bytes(VALUE self, VALUE bytes)
{
    libnet_t *l;
    int       num_bytes;
    VALUE     str;
    VALUE     inj_type;

    str = StringValue(bytes);

    Data_Get_Struct(self, libnet_t, l);

    inj_type = rb_iv_get(self, "@injection_type");

    if (ID2SYM(rb_intern("raw4")) == inj_type) {
        num_bytes = libnet_write_raw_ipv4(l, RSTRING(str)->ptr, RSTRING(str)->len);
    }
    else if (ID2SYM(rb_intern("raw6")) == inj_type) {
        num_bytes = libnet_write_raw_ipv6(l, RSTRING(str)->ptr, RSTRING(str)->len);
    }
    else if (ID2SYM(rb_intern("link")) == inj_type) {
        num_bytes = libnet_write_link(l, RSTRING(str)->ptr, RSTRING(str)->len);
    }
    else {
        rb_bug("BUG: invalid injection type found (this should not happen)");
    }

    if (num_bytes == -1) {
        rb_raise(rb_eRuntimeError, libnet_geterror(l));
    }

    return INT2NUM(num_bytes);
}