ipsumdump_ip.cc

Click is a modular router toolkit. To use it you ll need to know how to compile and install the sof

// -*- mode: c++; c-basic-offset: 4 -*-
/*
 * ipsumdump_ip.{cc,hh} -- IP network layer IP summary dump unparsers
 * Eddie Kohler
 *
 * Copyright (c) 2002 International Computer Science Institute
 * Copyright (c) 2004-2008 Regents of the University of California
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, subject to the conditions
 * listed in the Click LICENSE file. These conditions include: you must
 * preserve this copyright notice, and you cannot mention the copyright
 * holders in advertising related to the Software without their permission.
 * The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
 * notice is a summary of the Click LICENSE file; the license in that file is
 * legally binding.
 */

#include <click/config.h>

#include "ipsumdump_ip.hh"
#include <click/packet.hh>
#include <click/packet_anno.hh>
#include <click/md5.h>
#include <clicknet/ip.h>
#include <clicknet/tcp.h>
#include <clicknet/udp.h>
#include <click/confparse.hh>
#include <click/ipflowid.hh>
CLICK_DECLS

enum { T_IP_SRC, T_IP_DST, T_IP_TOS, T_IP_TTL, T_IP_FRAG, T_IP_FRAGOFF,
       T_IP_ID, T_IP_SUM, T_IP_PROTO, T_IP_OPT, T_IP_LEN, T_IP_CAPTURE_LEN,
       T_SPORT, T_DPORT, T_IP_HL };

namespace IPSummaryDump {

static bool ip_extract(PacketDesc& d, const FieldWriter *f)
{
    int network_length = d.p->network_length();
    switch (f->user_data) {

	// IP header properties
#define CHECK(l) do { if (!d.iph || network_length < (l)) return field_missing(d, MISSING_IP, (l)); } while (0)
      case T_IP_SRC:
	CHECK(16);
	d.v = d.iph->ip_src.s_addr;
	return true;
      case T_IP_DST:
	CHECK(20);
	d.v = d.iph->ip_dst.s_addr;
	return true;
      case T_IP_TOS:
	CHECK(2);
	d.v = d.iph->ip_tos;
	return true;
      case T_IP_TTL:
	CHECK(9);
	d.v = d.iph->ip_ttl;
	return true;
      case T_IP_FRAG:
	CHECK(8);
	if (IP_ISFRAG(d.iph))
	    d.v = (IP_FIRSTFRAG(d.iph) ? 'F' : 'f');
	else
	    d.v = (d.iph->ip_off & htons(IP_DF) ? '!' : '.');
	return true;
      case T_IP_FRAGOFF:
	CHECK(8);
	d.v = ntohs(d.iph->ip_off);
	return true;
      case T_IP_ID:
	CHECK(6);
	d.v = ntohs(d.iph->ip_id);
	return true;
      case T_IP_SUM:
	CHECK(12);
	d.v = ntohs(d.iph->ip_sum);
	return true;
      case T_IP_PROTO:
	CHECK(10);
	d.v = d.iph->ip_p;
	return true;
      case T_IP_OPT:
	if (!d.iph || (d.iph->ip_hl > 5 && network_length < (int)(d.iph->ip_hl << 2)))
	    return field_missing(d, MISSING_IP, (d.iph ? d.iph->ip_hl << 2 : 20));
	if (d.iph->ip_hl <= 5)
	    d.vptr[0] = d.vptr[1] = 0;
	else {
	    d.vptr[0] = (const uint8_t *) (d.iph + 1);
	    d.vptr[1] = d.vptr[0] + (d.iph->ip_hl << 2) - sizeof(click_ip);
	}
	return true;
      case T_IP_LEN:
	if (d.iph)
	    d.v = ntohs(d.iph->ip_len);
	else
	    d.v = d.p->length();
	if (d.force_extra_length)
	    d.v += EXTRA_LENGTH_ANNO(d.p);
	return true;
      case T_IP_HL:
	CHECK(1);
	d.v = d.iph->ip_hl << 2;
	return true;
      case T_IP_CAPTURE_LEN: {
	  uint32_t allow_len = (d.iph ? network_length : d.p->length());
	  uint32_t len = (d.iph ? ntohs(d.iph->ip_len) : allow_len);
	  d.v = (len < allow_len ? len : allow_len);
	  return true;
      }
#undef CHECK

      default:
	return false;
    }
}

static inline bool ip_proto_has_udp_ports(int ip_p)
{
    return ip_p == IP_PROTO_TCP || ip_p == IP_PROTO_UDP
	|| ip_p == IP_PROTO_DCCP || ip_p == IP_PROTO_UDPLITE;
}

static void ip_inject(PacketOdesc& d, const FieldReader *f)
{
    if (!d.make_ip(0))
	return;

    click_ip *iph = d.p->ip_header();
    switch (f->user_data) {
	// IP header properties
    case T_IP_SRC:
	iph->ip_src.s_addr = d.v;
	break;
    case T_IP_DST:
	iph->ip_dst.s_addr = d.v;
	break;
    case T_IP_TOS:
	iph->ip_tos = d.v;
	break;
    case T_IP_TTL:
	iph->ip_ttl = d.v;
	break;
    case T_IP_FRAG:
    case T_IP_FRAGOFF:
	iph->ip_off = htons(d.v);
	break;
    case T_IP_ID:
	iph->ip_id = htons(d.v);
	break;
    case T_IP_SUM:
	iph->ip_sum = htons(d.v);
	break;
    case T_IP_PROTO:
	iph->ip_p = d.v;
	break;
    case T_IP_OPT: {
	if (!d.vptr[0])
	    return;
	int olen = d.vptr[1] - d.vptr[0];
	int ip_hl = (sizeof(click_ip) + olen + 3) & ~3;
	if (d.p->network_length() < ip_hl) {
	    if (!(d.p = d.p->put(ip_hl - d.p->network_length())))
		return;
	    iph = d.p->ip_header();
	}
	if (ip_hl > (int) (iph->ip_hl << 2)) {
	    d.p->set_ip_header(iph, ip_hl);
	    iph->ip_hl = ip_hl >> 2;
	}
	memcpy(d.p->network_header() + sizeof(click_ip), d.vptr[0], olen);
	memset(d.p->network_header() + sizeof(click_ip) + olen,
	       IPOPT_EOL, ip_hl - olen);
	break;
    }
#if 0
    case T_IP_CAPTURE_LEN: {
	uint32_t allow_len = (iph ? network_length : d.p->length());
	uint32_t len = (iph ? ntohs(iph->ip_len) : allow_len);
	d.v = (len < allow_len ? len : allow_len);
	break;
    }
#endif
    case T_IP_HL:
	d.v = (d.v + 3) & ~3;
	if ((int) d.v > (int) (iph->ip_hl << 2)) {
	    int more = d.v - (iph->ip_hl << 2);
	    if (!(d.p = d.p->put(more)))
		return;
	    iph = d.p->ip_header();
	    d.p->set_ip_header(iph, d.v);
	    memset(d.p->transport_header() - more, IPOPT_EOL, more);
	}
	iph->ip_hl = d.v >> 2;
	break;
    case T_IP_LEN:
	d.want_len = d.p->network_header_offset() + d.v;
	break;
    }
}

static void ip_outa(const PacketDesc& d, const FieldWriter *f)
{
    switch (f->user_data) {
      case T_IP_SRC:
      case T_IP_DST:
	*d.sa << IPAddress(d.v);
	break;
      case T_IP_FRAG:
	*d.sa << (char) d.v;
	break;
      case T_IP_FRAGOFF:
	*d.sa << ((d.v & IP_OFFMASK) << 3);
	if (d.v & IP_MF)
	    *d.sa << '+';
	if (d.v & IP_DF)
	    *d.sa << '!';
	break;
      case T_IP_PROTO:
	switch (d.v) {
	  case IP_PROTO_TCP:	*d.sa << 'T'; break;
	  case IP_PROTO_UDP:	*d.sa << 'U'; break;
	  case IP_PROTO_ICMP:	*d.sa << 'I'; break;
	  default:		*d.sa << d.v; break;
	}
	break;
      case T_IP_OPT:
	if (!d.vptr[0])
	    *d.sa << '.';
	else
	    unparse_ip_opt(*d.sa, d.vptr[0], d.vptr[1] - d.vptr[0], DO_IPOPT_ALL_NOPAD);
	break;
    }
}

static bool ip_ina(PacketOdesc& d, const String &s, const FieldReader *f)
{
    switch (f->user_data) {
    case T_IP_SRC:
    case T_IP_DST: {
	IPAddress a;
	if (cp_ip_address(s, &a, d.e)) {
	    d.v = a.addr();
	    return true;
	}
	break;
    }
    case T_IP_FRAG:
    case T_IP_FRAGOFF: {
	if (s.length() == 1) {
	    if (s[0] == '.') {
		d.v = 0;
		return true;
	    } else if (s[0] == '!') {
		d.v = IP_DF;
		return true;
	    } else if (s[0] == 'F') {
		d.v = IP_MF;
		return true;
	    } else if (s[0] == 'f') {
		d.v = 100;	// arbitrary nonzero offset
		return true;
	    }
	}
	d.v = 0;
	const char *new_end = cp_integer(s.begin(), s.end(), 0, &d.v);
	if (d.minor_version > 0)
	    d.v >>= 3;
	for (; new_end != s.end(); ++new_end)
	    if (*new_end == '!')
		d.v |= IP_DF;
	    else if (*new_end == '+')
		d.v |= IP_MF;
	    else
		break;
	if (new_end == s.end() && s.length())
	    return true;
	break;
    }
    case T_IP_PROTO:
	if (s.equals("T", 1)) {
	    d.v = IP_PROTO_TCP;
	    return true;
	} else if (s.equals("U", 1)) {
	    d.v = IP_PROTO_UDP;
	    return true;
	} else if (s.equals("I", 1)) {
	    d.v = IP_PROTO_ICMP;
	    return true;
	} else if (cp_integer(s, &d.v) && d.v < 256)
	    return true;
	break;
#if 0
      case T_IP_OPT:
	if (!d.vptr[0])
	    *d.sa << '.';
	else
	    unparse_ip_opt(*d.sa, d.vptr[0], d.vptr[1] - d.vptr[0], DO_IPOPT_ALL_NOPAD);
	break;
#endif
    }
    return false;
}

static void ip_outb(const PacketDesc& d, bool ok, const FieldWriter *f)
{
    if (f->user_data == T_IP_OPT) {
	if (!ok || !d.vptr)
	    *d.sa << '\0';
	else
	    unparse_ip_opt_binary(*d.sa, d.vptr[0], d.vptr[1] - d.vptr[0], DO_IPOPT_ALL);
    }
}

static const uint8_t* ip_inb(PacketOdesc& d, const uint8_t *s, const uint8_t *ends, const FieldReader *f)
{
    if (f->user_data == T_IP_OPT && s + s[0] + 1 <= ends) {
	d.vptr[0] = s + 1;
	d.vptr[1] = d.vptr[0] + s[0];
	return s + s[0] + 1;
    } else
	return ends;
}


static bool transport_extract(PacketDesc& d, const FieldWriter *f)
{
    Packet* p = d.p;
    switch (f->user_data) {
	// TCP/UDP header properties
    case T_SPORT:
    case T_DPORT: {
	bool dport = (f->user_data == T_DPORT);
	if (d.iph
	    && p->network_length() > (int)(d.iph->ip_hl << 2)
	    && IP_FIRSTFRAG(d.iph)
	    && ip_proto_has_udp_ports(d.iph->ip_p)
	    && p->transport_length() >= (dport ? 4 : 2)) {
	    const click_udp *udph = p->udp_header();
	    d.v = ntohs(dport ? udph->uh_dport : udph->uh_sport);
	    return true;
	}
	return field_missing(d, IP_PROTO_TCP_OR_UDP, dport ? 4 : 2);
    }
    }
    return false;
}

static void transport_inject(PacketOdesc& d, const FieldReader *f)
{
    if (!d.make_ip(0) || !d.make_transp())
	return;
    click_ip *iph = d.p->ip_header();
    if (iph->ip_p && !ip_proto_has_udp_ports(iph->ip_p))
	return;

    switch (f->user_data) {
	// TCP/UDP header properties
    case T_SPORT:
	d.p->udp_header()->uh_sport = htons(d.v);
	break;
    case T_DPORT:
	d.p->udp_header()->uh_dport = htons(d.v);
	break;
    }
}


#define U DO_IPOPT_UNKNOWN
static int ip_opt_mask_mapping[] = {
    DO_IPOPT_PADDING, DO_IPOPT_PADDING,		// EOL, NOP
    U, U, U, U,	U,				// 2, 3, 4, 5, 6
    DO_IPOPT_ROUTE,				// RR
    U, U, U, U, U, U, U, U, U, U, U, U, U,	// 8-20
    U, U, U, U, U, U, U, U, U, U,		// 21-30
    U, U, U, U, U, U, U, U, U, U,		// 31-40
    U, U, U, U, U, U, U, U, U, U,		// 41-50
    U, U, U, U, U, U, U, U, U, U,		// 51-60
    U, U, U, U, U, U, U,			// 61-67
    DO_IPOPT_TS, U, U,				// TS, 69-70
    U, U, U, U, U, U, U, U, U, U,		// 71-80
    U, U, U, U, U, U, U, U, U, U,		// 81-90
    U, U, U, U, U, U, U, U, U, U,		// 91-100
    U, U, U, U, U, U, U, U, U, U,		// 101-110
    U, U, U, U, U, U, U, U, U, U,		// 111-120
    U, U, U, U, U, U, U, U, U,			// 121-129
    DO_IPOPT_UNKNOWN, DO_IPOPT_ROUTE,		// SECURITY, LSRR
    U, U, U, U,					// 132-135
    DO_IPOPT_UNKNOWN, DO_IPOPT_ROUTE,		// SATID, SSRR
    U, U, U,					// 138-140
    U, U, U, U, U, U, U,			// 141-147
    DO_IPOPT_UNKNOWN				// RA
};
#undef U

void unparse_ip_opt(StringAccum& sa, const uint8_t* opt, int opt_len, int mask)
{
    int initial_sa_len = sa.length();
    const uint8_t *end_opt = opt + opt_len;
    const char *sep = "";

    while (opt < end_opt)
	switch (*opt) {
	  case IPOPT_EOL:
	    if (mask & DO_IPOPT_PADDING)
		sa << sep << "eol";
	    goto done;
	  case IPOPT_NOP:
	    if (mask & DO_IPOPT_PADDING) {
		sa << sep << "nop";
		sep = ";";
	    }
	    opt++;
	    break;
	  case IPOPT_RR:
	    if (opt + opt[1] > end_opt || opt[1] < 3 || opt[2] < 4)
		goto bad_opt;
	    if (!(mask & DO_IPOPT_ROUTE))
		goto unknown;
	    sa << sep << "rr";
	    goto print_route;
	  case IPOPT_LSRR:
	    if (opt + opt[1] > end_opt || opt[1] < 3 || opt[2] < 4)
		goto bad_opt;
	    if (!(mask & DO_IPOPT_ROUTE))
		goto unknown;
	    sa << sep << "lsrr";
	    goto print_route;
	  case IPOPT_SSRR:
	    if (opt + opt[1] > end_opt || opt[1] < 3 || opt[2] < 4)
		goto bad_opt;
	    if (!(mask & DO_IPOPT_ROUTE))
		goto unknown;
	    sa << sep << "ssrr";
	    goto print_route;
	  print_route: {
		const uint8_t *o = opt + 3, *ol = opt + opt[1], *op = opt + opt[2] - 1;
		sep = "";
		sa << '{';
		for (; o + 4 <= ol; o += 4) {
		    if (o == op) {
			if (opt[0] == IPOPT_RR)
			    break;
			sep = "^";
		    }
		    sa << sep << (int)o[0] << '.' << (int)o[1] << '.' << (int)o[2] << '.' << (int)o[3];
		    sep = ",";
		}
		if (o == ol && o == op && opt[0] != IPOPT_RR)
		    sa << '^';
		sa << '}';
		if (o + 4 <= ol && o == op && opt[0] == IPOPT_RR)
		    sa << '+' << (ol - o) / 4;
		opt = ol;