net_util.h File Reference

#include "config.h"
#include <assert.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <netinet/ip_icmp.h>
#include "util.h"

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Classes
struct	ip6_hdr
struct	subnet_type
Defines
#define	NUM_ADDR_WORDS   1
Typedefs
typedef uint32	addr_type
typedef const uint32	const_addr_type
Functions
int	seq_between (uint32 a, uint32 b, uint32 c)
int	seq_delta (uint32 a, uint32 b)
int	ones_complement_checksum (const void *p, int b, uint32 sum)
int	tcp_checksum (const struct ip *ip, const struct tcphdr *tp, int len)
int	udp_checksum (const struct ip *ip, const struct udphdr *up, int len)
int	icmp_checksum (const struct icmp *icmpp, int len)
uint32	addr_to_net (uint32 addr)
char	addr_to_class (uint32 addr)
const char *	dotted_addr (uint32 addr, int alternative=0)
const char *	dotted_addr (const uint32 *addr, int alternative=0)
const char *	dotted_net (uint32 addr)
const char *	dotted_net6 (const uint32 *addr)
uint32	dotted_to_addr (const char *addr_text)
uint32 *	dotted_to_addr6 (const char *addr_text)
int	is_v4_addr (const uint32 addr[4])
uint32	to_v4_addr (const uint32 *addr)
uint32	mask_addr (uint32 a, uint32 top_bits_to_keep)
const uint32 *	mask_addr (const uint32 *a, uint32 top_bits_to_keep)
void	copy_addr (const uint32 *src_a, uint32 *dst_a)
int	addr_eq (const uint32 *a1, const uint32 *a2)
int	subnet_eq (const subnet_type *s1, const subnet_type *s2)
uint32	extract_uint32 (const u_char *data)
double	ntohd (double d)
double	htond (double d)

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Define Documentation

#define NUM_ADDR_WORDS   1

Definition at line 73 of file net_util.h. Referenced by PacketFilter::AddDst(), PacketFilter::AddSrc(), PrefixTable::Insert(), PrefixTable::Lookup(), PacketFilter::Match(), TCP_Connection::NextPacket(), PrefixTable::Remove(), PacketFilter::RemoveDst(), and PacketFilter::RemoveSrc().

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Typedef Documentation

addr_type

Definition at line 71 of file net_util.h. Referenced by PacketFilter::AddDst(), DivideExpr::AddrFold(), BinaryExpr::AddrFold(), DNS_Mgr::AddrListDelta(), PacketFilter::AddSrc(), Val::AsAddr(), RemoteSerializer::Connect(), DNS_Mgr::DumpAddrList(), NetSessions::FindConnection(), RemoteSerializer::Listen(), SubNetVal::Mask(), PacketFilter::RemoveDst(), PacketFilter::RemoveSrc(), same_atomic_val(), and CompositeHash::SingleValHash().

typedef const uint32 const_addr_type

Definition at line 72 of file net_util.h. Referenced by PrefixTable::Insert(), PrefixTable::Lookup(), and PrefixTable::Remove().

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Function Documentation

int addr_eq (  const uint32 *  a1, const uint32 *  a2 )  [inline]

Definition at line 152 of file net_util.h. References uint32. Referenced by DNS_Mgr::AddrListDelta(), NetSessions::DoNextPacket(), RuleMatcher::InitEndpoint(), ConnCompressor::Instantiate(), and same_atomic_val(). { #ifdef BROv6 return a1[0] == a2[0] && a1[1] == a2[1] && a1[2] == a2[2] && a1[3] == a2[3]; #else return a1[0] == a2[0]; #endif }

char addr_to_class (  uint32  addr  )

Definition at line 121 of file net_util.cc. References addr, CHECK_CLASS, CLASS_B, CLASS_C, CLASS_D, CLASS_E, and uint32. Referenced by AnonymizeIPAddr::PreserveNet(). { if ( CHECK_CLASS(addr, CLASS_E) ) return 'E'; else if ( CHECK_CLASS(addr, CLASS_D) ) return 'D'; else if ( CHECK_CLASS(addr, CLASS_C) ) return 'C'; else if ( CHECK_CLASS(addr, CLASS_B) ) return 'B'; else return 'A'; }

uint32 addr_to_net (  uint32  addr  )

Definition at line 135 of file net_util.cc. References addr, CHECK_CLASS, CLASS_B, CLASS_C, CLASS_D, and uint32. Referenced by NetVal::NetVal(). { if ( CHECK_CLASS(addr, CLASS_D) ) ; // class D's are left alone ### else if ( CHECK_CLASS(addr, CLASS_C) ) addr = addr & 0xffffff00; else if ( CHECK_CLASS(addr, CLASS_B) ) addr = addr & 0xffff0000; else addr = addr & 0xff000000; return addr; }

void copy_addr (  const uint32 *  src_a, uint32 *  dst_a )  [inline]

Definition at line 140 of file net_util.h. References uint32. Referenced by ConnID::BuildConnKey(), Connection::Connection(), TCP_Connection::NextPacket(), and ConnCompressor::PendingConnToPacket(). { #ifdef BROv6 dst_a[0] = src_a[0]; dst_a[1] = src_a[1]; dst_a[2] = src_a[2]; dst_a[3] = src_a[3]; #else dst_a[0] = src_a[0]; #endif }

const char* dotted_addr (  const uint32 *  addr, int  alternative = 0 )

Definition at line 162 of file net_util.cc. References addr, is_v4_addr(), to_v4_addr(), and uint32. Referenced by MutableVal::Bind(), UDP_Connection::Describe(), TCP_Connection::Describe(), Packet::Describe(), ICMP_Connection::Describe(), dotted_net6(), DNS_Mgr::DumpAddrList(), DNS_Mgr::LookupAddr(), AnonymizeIPAddr_A50::PreservePrefix(), DNS_Mapping::ReqStr(), DNS_Mapping::Save(), dce_rpc_endpoint_addr::to_string(), SubNetVal::ValDescribe(), and Val::ValDescribe(). { #ifdef BROv6 if ( is_v4_addr(addr) ) return dotted_addr(addr[3], alternative); static char buf[256]; if ( inet_ntop(AF_INET6, addr, buf, sizeof buf) == NULL ) return "<bad IPv6 address conversion>"; return buf; #else return dotted_addr(to_v4_addr(addr), alternative); #endif }

const char* dotted_addr (  uint32  addr, int  alternative = 0 )

Definition at line 149 of file net_util.cc. References addr, fmt, snprintf(), and uint32. { addr = ntohl(addr); const char* fmt = alternative ? "%d,%d.%d.%d" : "%d.%d.%d.%d"; static char buf[32]; snprintf(buf, sizeof(buf), fmt, addr >> 24, (addr >> 16) & 0xff, (addr >> 8) & 0xff, addr & 0xff); return buf; }

const char* dotted_net (  uint32  addr  )

Definition at line 180 of file net_util.cc. References addr, CHECK_CLASS, CLASS_C, CLASS_D, and uint32. Referenced by NetVal::ValDescribe(). { addr = ntohl(addr); static char buf[32]; if ( CHECK_CLASS(addr, CLASS_D) ) sprintf(buf, "%d.%d.%d.%d", addr >> 24, (addr >> 16) & 0xff, (addr >> 8) & 0xff, addr & 0xff); else if ( CHECK_CLASS(addr, CLASS_C) ) sprintf(buf, "%d.%d.%d", addr >> 24, (addr >> 16) & 0xff, (addr >> 8) & 0xff); else // Same for class A's and B's. sprintf(buf, "%d.%d", addr >> 24, (addr >> 16) & 0xff); return buf; }

const char* dotted_net6 (  const uint32 *  addr  )

Definition at line 202 of file net_util.cc. References addr, dotted_addr(), and uint32. Referenced by NetVal::ValDescribe(). { // ### this isn't right, but net's should go away eventually ... return dotted_addr(addr); }

uint32 dotted_to_addr (  const char *  addr_text  )

Definition at line 208 of file net_util.cc. References addr, error(), sscanf(), and uint32. Referenced by AddrVal::AddrVal(), and DNS_Mapping::DNS_Mapping(). { int addr[4]; if ( sscanf(addr_text, "%d.%d.%d.%d", addr+0, addr+1, addr+2, addr+3) != 4 ) { error("bad dotted address:", addr_text ); return 0; } if ( addr[0] < 0 || addr[1] < 0 || addr[2] < 0 || addr[3] < 0 || addr[0] > 255 || addr[1] > 255 || addr[2] > 255 || addr[3] > 255 ) { error("bad dotted address:", addr_text); return 0; } uint32 a = (addr[0] << 24) | (addr[1] << 16) | (addr[2] << 8) | addr[3]; // ### perhaps do gethostbyaddr here? return uint32(htonl(a)); }

uint32* dotted_to_addr6 (  const char *  addr_text  )

Referenced by AddrVal::AddrVal().

uint32 extract_uint32 (  const u_char *  data  )

Definition at line 334 of file net_util.cc. References uint32, and val. Referenced by TCP_Connection::BuildOSVal(). { uint32 val; val = data[0] << 24; val |= data[1] << 16; val |= data[2] << 8; val |= data[3]; return val; }

double htond (  double  d  )  [inline]

Definition at line 212 of file net_util.h. References ntohd(). Referenced by SocketComm::ProcessParentMessage(), SocketComm::ProcessRemoteMessage(), RemoteSerializer::SendPing(), and BinarySerializationFormat::Write(). { return ntohd(d); }

int icmp_checksum (  const struct icmp *  icmpp, int  len )

Definition at line 98 of file net_util.cc. References len, ones_complement_checksum(), and uint32. Referenced by ICMP_Connection::NextPacket(). { uint32 sum; if ( len % 2 == 1 ) // Add in pad byte. sum = htons(((const u_char*) icmpp)[len - 1] << 8); else sum = 0; sum = ones_complement_checksum((void*) icmpp, len, sum); return sum; }

int is_v4_addr (  const uint32  addr[4]  )

Referenced by RemoteSerializer::Connect(), dotted_addr(), SubNetVal::Init(), RemoteSerializer::Listen(), mask_addr(), to_v4_addr(), and SubNetVal::ValDescribe().

const uint32* mask_addr (  const uint32 *  a, uint32  top_bits_to_keep )

Definition at line 289 of file net_util.cc. References addr, error(), is_v4_addr(), and uint32. Referenced by SubNetVal::Init(). { #ifdef BROv6 static uint32 addr[4]; addr[0] = a[0]; addr[1] = a[1]; addr[2] = a[2]; addr[3] = a[3]; // This is a bit dicey: if it's a v4 address, then we interpret // the mask as being with respect to 32 bits total, even though // strictly speaking, the v4 address comprises the least-significant // bits out of 128, rather than the most significant. However, // we only do this if the mask itself is consistent for a 32-bit // address. uint32 max_bits = (is_v4_addr(a) && top_bits_to_keep <= 32) ? 32 : 128; if ( top_bits_to_keep == 0 || top_bits_to_keep > max_bits ) { error("bad address mask value", top_bits_to_keep); return addr; } int word = 3; // start zeroing out with word #3 int bits_to_chop = max_bits - top_bits_to_keep; // bits to discard while ( bits_to_chop >= 32 ) { // there's an entire word to discard addr[word] = 0; --word; // move on to next, more significant word bits_to_chop -= 32; // we just go rid of 32 bits } // All that's left to work with now is the word pointed to by "word". uint32 addr32 = ntohl(addr[word]); addr32 >>= bits_to_chop; addr32 <<= bits_to_chop; addr[word] = htonl(addr32); return addr; #else return a; #endif }

uint32 mask_addr (  uint32  a, uint32  top_bits_to_keep )

Definition at line 266 of file net_util.cc. References addr, error(), and uint32. { if ( top_bits_to_keep > 32 ) { error("bad address mask value", top_bits_to_keep); return a; } if ( top_bits_to_keep == 0 ) // The shifts below don't have any effect with 0, i.e., // 1 << 32 does not yield 0; either due to compiler // misoptimization or language semantics. return 0; uint32 addr = ntohl(a); int shift = 32 - top_bits_to_keep; addr >>= shift; addr <<= shift; return htonl(addr); }

double ntohd (  double  d  )  [inline]

Definition at line 192 of file net_util.h. Referenced by htond(), SocketComm::ProcessParentMessage(), RemoteSerializer::ProcessPongMsg(), SocketComm::ProcessRemoteMessage(), and BinarySerializationFormat::Read(). { assert(sizeof(d) == 8); double tmp; char* src = (char*) &d; char* dst = (char*) &tmp; dst[0] = src[7]; dst[1] = src[6]; dst[2] = src[5]; dst[3] = src[4]; dst[4] = src[3]; dst[5] = src[2]; dst[6] = src[1]; dst[7] = src[0]; return tmp; }

int ones_complement_checksum (  const void *  p, int  b, uint32  sum )

Definition at line 37 of file net_util.cc. References p, and uint32. Referenced by NetSessions::DoNextPacket(), ICMP_Connection::ExtractICMPContext(), TCP_TracePacket::Finish(), icmp_checksum(), tcp_checksum(), TCP_Endpoint::TCP_Endpoint(), udp_checksum(), and TCP_Endpoint::ValidChecksum(). { const u_short* sp = (u_short*) p; // better be aligned! b /= 2; // convert to count of short's /* No need for endian conversions. */ while ( --b >= 0 ) sum += *sp++; while ( sum > 0xffff ) sum = (sum & 0xffff) + (sum >> 16); return sum; }

int seq_between (  uint32  a, uint32  b, uint32  c )  [inline]

Definition at line 93 of file net_util.h. References uint32. Referenced by TCP_Connection::NextPacket(). { if ( b <= c ) return a >= b && a <= c; else return a >= b || a <= c; }

int seq_delta (  uint32  a, uint32  b )  [inline]

Definition at line 102 of file net_util.h. References int, and uint32. Referenced by TCP_EndpointStats::DataSent(), TCP_Connection::NextPacket(), and TCP_Endpoint::Size(). { return int(a-b); }

int subnet_eq (  const subnet_type *  s1, const subnet_type *  s2 )  [inline]

Definition at line 164 of file net_util.h. References subnet_type::net, and subnet_type::width. Referenced by same_atomic_val(). { #ifdef BROv6 return s1->net[0] == s2->net[0] && s1->net[1] == s2->net[1] && s1->net[2] == s2->net[2] && s1->net[3] == s2->net[3] && s1->width == s2->width; #else return s1->net == s2->net && s1->width == s2->width; #endif }

int tcp_checksum (  const struct ip *  ip, const struct tcphdr *  tp, int  len )

Definition at line 53 of file net_util.cc. References ip::ip_dst, len, ones_complement_checksum(), tcphdr::th_off, and uint32. Referenced by TCP_TracePacket::Finish(). { int tcp_len = tp->th_off * 4 + len; uint32 sum; if ( len % 2 == 1 ) // Add in pad byte. sum = htons(((const u_char*) tp)[tcp_len - 1] << 8); else sum = 0; sum = ones_complement_checksum((void*) &ip->ip_src.s_addr, 4, sum); sum = ones_complement_checksum((void*) &ip->ip_dst.s_addr, 4, sum); uint32 addl_pseudo = (htons(IPPROTO_TCP) << 16) | htons((unsigned short) tcp_len); sum = ones_complement_checksum((void*) &addl_pseudo, 4, sum); sum = ones_complement_checksum((void*) tp, tcp_len, sum); return sum; }

uint32 to_v4_addr (  const uint32 *  addr  )

Definition at line 255 of file net_util.cc. References addr, internal_error(), is_v4_addr(), and uint32. Referenced by RemoteSerializer::Connect(), dotted_addr(), is_mapped_dce_rpc_endpoint(), TCP_Rewriter::LeaveAddrInTheClear(), RemoteSerializer::Listen(), and TCP_Rewriter::TCP_Rewriter(). { #ifdef BROv6 if ( ! is_v4_addr(addr) ) internal_error("conversion of non-IPv4 address to IPv4 address"); return addr[3]; #else return addr[0]; #endif }

int udp_checksum (  const struct ip *  ip, const struct udphdr *  up, int  len )

Definition at line 76 of file net_util.cc. References ip::ip_dst, len, ones_complement_checksum(), and uint32. Referenced by UDP_Connection::NextPacket(). { uint32 sum; if ( len % 2 == 1 ) // Add in pad byte. sum = htons(((const u_char*) up)[len - 1] << 8); else sum = 0; sum = ones_complement_checksum((void*) &ip->ip_src.s_addr, 4, sum); sum = ones_complement_checksum((void*) &ip->ip_dst.s_addr, 4, sum); uint32 addl_pseudo = (htons(IPPROTO_UDP) << 16) | htons((unsigned short) len); sum = ones_complement_checksum((void*) &addl_pseudo, 4, sum); sum = ones_complement_checksum((void*) up, len, sum); return sum; }

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