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OpenBTS-UMTS/SGSNGGSN/miniggsn.cpp

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/*
* OpenBTS provides an open source alternative to legacy telco protocols and
* traditionally complex, proprietary hardware systems.
*
* Copyright 2011, 2014 Range Networks, Inc.
*
* This software is distributed under the terms of the GNU Affero General
* Public License version 3. See the COPYING and NOTICE files in the main
* directory for licensing information.
*
* This use of this software may be subject to additional restrictions.
* See the LEGAL file in the main directory for details.
*/
//TODO - include the TCP sequence number in the message,
// and identify the duplicate packets,
// then rerun a test downloading a single jpg
// with tossing off, to see what is happening.
// iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to 192.168.1.8
// iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
// iptables -t nat -F # Flush current tables
// iptables -t nat -L # List current tables
// ---
// Options:
// o 2 tunnels. First is read/write by the ggsn. Second is configured via linux.
// This gives us a pseudo-'device' so we can use linux forwarding.
// iptables -t nat -A POSTROUTING -out eth0 -j MASQUERADE
// iptables -A FORWARD -i tun2 -j ACCEPT
// Another advantage is the tunnel could go to a remote machine.
// Or the first tunnel could terminate back in the OpenBTS.
// o Do NAT myself.
// o Use linux NAT. Write MS->Net packets to router. Bind raw socket on 192.168.1.8 for
// all packets, looking for our own.
// NOTES:
// The ip tunnel local/remote specify the outer transport layer IP addresses in the IPIP
// protocol header prepended to packets sent on the tunnel.
// The ifconfig adds two local addresses
//
// Tunnel Example:
// Network A: net 10.0.1.0/24 router 10.0.1.1 public address 172.16.17.18 on public net C
// Network B: net 10.0.2.0/24 router 10.0.2.1 public address 172.19.20.21 on public net C
// Network A:
// ip tunnel add netb mode gre remote 172.19.20.21 local 172.16.17.18
// # Apparently this tunnel is the router.
// ip addr add 10.0.1.1 dev netb
// ip route add 10.0.2.0/24 dev netb
// Or for ipip tunneling:
// ifconfig tunl0 10.0.1.1 pointopoint 172.19.20.21
// route add -net 10.0.2.0 netmask 255.255.255.0 dev netb
// Network B:
// ip tunnel add neta mode gre remote 172.16.17.18 local 172.19.20.21
// ip addr add 10.0.2.1 dev neta
// ip addr add 10.0.1.0/24 dev neta
// Or for ipip tunneling:
// ifconfig tunl0 10.0.2.1 pointopoint 172.19.20.21
// route add -net 10.0.2.0 netmask 255.255.255.0 dev tunl0
//
//
// Another Tunnel example from IPIPNotes:
// Router_1 eth0: 1.2.3.4 - Asterisk system
// Router_2 eth0: 4.3.2.1 eth1: 10.0.0.1 NAT private network and SIP phones.
// Router_1
// ip tunnel add iptun mode ipip remote 4.3.2.1 local 10.0.1.1
// route add -net 10.0.2.0/24 dev iptun
// Router_2
// ip tunnel add iptun mode ipip remote 1.2.3.4 local 10.0.2.1
// route add -net 10.0.1.0/24 dev iptun
// Router_1
// route add -net 10.0.0.0/24 dev iptun
// route add -net 10.0.0.0/24 gw 10.0.0.1
// Note: The comment is backwards.
// Allows you to ping any device on 10.0.0.0/24 from router_1 (not from router_2)
// Allows any 10.0.0.) device to ping router1 using 10.0.1.1
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <getopt.h>
#include <errno.h>
#include <signal.h>
#include <sys/fcntl.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <poll.h>
#include <netdb.h> // pat added for gethostbyname
#include <netinet/ip.h> // pat added for IPv4 iphdr
#include <netinet/tcp.h> // pat added for tcphdr
#include <netinet/udp.h> // pat added for udphdr
#include <linux/if.h> // pat added.
#include <linux/if_tun.h> // pat added.
//#include <sys/ioctl.h> // pat added, then removed because it defines NCC used in GSMConfig.
#include <assert.h> // pat added
#include <stdarg.h> // pat added
#include <time.h> // pat added.
#include <sys/time.h>
#include <sys/types.h>
#include <wait.h>
#include "miniggsn.h"
#undef NCC // Make sure. This is defined in ioctl.h, but used as a name in GSMConfig.h.
#include "Ggsn.h"
#include <Configuration.h>
// A mini-GGSN included inside the SGSN.
// Each MS will be assigned a dynamic IP address.
// We will use one 256-wide bank of IP address, eg: 192.168.99.1 - 192.68.99.254.
// This needs to be a config option.
// The addresses are be serviced by a NAT running on this box.
// An alternative architecture would be to get IP addresses from a DHCP server
// on whatever router is doing the NAT.
// The NAT could be tied to a static IP; a dynamic IP; or if the bts has two IP addresses,
// the NAT could be tied to the second static or dynamic IP address used solely for phones;
// or tied to a tunnel that goes elsewhere.
// Since there are so many possibilibies, the nat is configured externally.
namespace SGSN {
int pdpWriteHighSide(PdpContext *pdp, unsigned char *packet, unsigned len);
int tun_fd = -1; // This is the tunnel we use to talk with the MSs.
FILE *mg_log_fp = NULL; // Extra log file for IP traffic.
int mg_debug_level = 0;
// old:
//static char const *mg_base_ip_str = "192.168.99.1"; // This did not raw bind.
//static char const *mg_base_ip_route = "192.168.99.0/24";
//static char const *mg_net_mask = "255.255.255.0"; // todo: get this from "/24" above.
static struct GgsnConfig {
unsigned mgMaxPduSize;
int mgMaxConnections; // The maximum number of PDP contexts, which is roughly
// the maximum number of simultaneous MS allowed.
unsigned mgIpTimeout; // Dont reuse a connection for this many seconds.
unsigned mgIpTossDup; // Toss duplicate packets.
} ggConfig;
// Mini-Firewall rules
struct GgsnFirewallRule {
GgsnFirewallRule *next;
uint32_t ipBasenl;
uint32_t ipMasknl;
GgsnFirewallRule(GgsnFirewallRule *wnext,uint32_t wipbasenl, uint32_t wmasknl) :
next(wnext),ipBasenl(wipbasenl),ipMasknl(wmasknl) {}
};
GgsnFirewallRule *gFirewallRules = NULL;
void addFirewallRule(uint32_t ipbasenl,uint32_t masknl) {
gFirewallRules = new GgsnFirewallRule(gFirewallRules,ipbasenl,masknl);
}
static mg_con_t *mg_cons = 0;
// Now in Utils.cpp
//const char *timestr()
//{
// struct timeval tv;
// struct tm tm;
// static char result[30];
// gettimeofday(&tv,NULL);
// localtime_r(&tv.tv_sec,&tm);
// unsigned tenths = tv.tv_usec / 100000; // Rounding down is ok.
// sprintf(result," %02d:%02d:%02d.%1d",tm.tm_hour,tm.tm_min,tm.tm_sec,tenths);
// return result;
//}
// Find a free IP connection or return NULL.
// Each PDP context activation gets a new IP address.
// The IP addresses are recycled after tiimeout.
// 7-10-2012: Each MS may ask for several IP addresses with different NSAPI.
// The IMSI+NSAPI now maps to an IP address in a semi-permanent way, so the MS
// effectively has a static IP address within the range assigned by the BTS,
// until the BTS is power cycled. The ptmsi is a unique id associated with the imsi.
mg_con_t *mg_con_find_free(uint32_t ptmsi, int nsapi)
{
// Start by looking for this specific old connection:
// TODO: This should use a map for efficiency.
int i;
mg_con_t *mgp = &mg_cons[0];
for (i=0; i < ggConfig.mgMaxConnections; i++, mgp++) {
if (mgp->mg_ptmsi == ptmsi && mgp->mg_nsapi == nsapi) {
return mgp;
}
}
// Look for an unused IP address.
double now = pat_timef();
static int mgnextindex = 0;
for (i=0; i < ggConfig.mgMaxConnections; i++) {
mgp = &mg_cons[mgnextindex];
if (++mgnextindex == ggConfig.mgMaxConnections) { mgnextindex = 0; }
if (mgp->mg_pdp == NULL) {
// Dont reuse an ip address for mg_ip_timeout.
// TCP packets will continue to arrive for an IP address
// for quite some time after it becomes inactive.
if (mgp->mg_time_last_close && mgp->mg_time_last_close + ggConfig.mgIpTimeout > now) continue;
//mgp->mg_pdp = pctx;
mgp->mg_ptmsi = ptmsi;
mgp->mg_nsapi = nsapi;
return mgp;
}
}
return NULL;
}
void mg_con_open(mg_con_t *mgp,PdpContext *pdp)
{
mgp->mg_pdp = pdp;
}
void mg_con_close(mg_con_t *mgp)
{
mgp->mg_pdp = NULL;
mgp->mg_time_last_close = pat_timef();
}
#if 0
static mg_con_t *mg_con_find_by_ctx(PdpContext *pctx)
{
int i; mg_con_t *mgp = mg_cons;
for (i=0; i < ggConfig.mgMaxConnections; i++, mgp++) {
if (mgp->mg_pdp == pctx) { return mgp; }
}
return NULL;
}
#endif
static mg_con_t *mg_con_find_by_ip(uint32_t addr)
{
int i; mg_con_t *mgp = mg_cons;
for (i=0; i < ggConfig.mgMaxConnections; i++, mgp++) {
if (mgp->mg_ip == addr) { return mgp; }
}
return NULL;
}
static bool verbose = true;
static char *packettoa(char *result,unsigned char *packet, int len)
{
struct iphdr *iph = (struct iphdr*)packet;
char nbuf1[40], nbuf2[40];
if (verbose && iph->protocol == IPPROTO_TCP) {
struct tcphdr *tcph = (struct tcphdr*) (packet + 4 * iph->ihl);
sprintf(result,"proto=%s %d byte packet seq=%u ack=%u id=%u frag=%u from %s:%d to %s:%d",
ip_proto_name(iph->protocol), len, tcph->seq, tcph->ack_seq,
iph->id, iph->frag_off,
ip_ntoa(iph->saddr,nbuf1),tcph->source,
ip_ntoa(iph->daddr,nbuf2),tcph->dest);
} else {
sprintf(result,"proto=%s %d byte packet from %s to %s",
ip_proto_name(iph->protocol), len,
ip_ntoa(iph->saddr,nbuf1),
ip_ntoa(iph->daddr,nbuf2));
}
return result;
}
unsigned char *miniggsn_rcv_npdu(int *plen, uint32_t *dstaddr)
{
static unsigned char *recvbuf = NULL;
if (recvbuf == NULL) {
recvbuf = (unsigned char*)malloc(ggConfig.mgMaxPduSize+2);
if (!recvbuf) { /**error = -ENOMEM;*/ return NULL; }
}
// The O_NONBLOCK was set by default! Is not happening any more.
{
int flags = fcntl(tun_fd,F_GETFL,0);
if (flags & O_NONBLOCK) {
//MGDEBUG(4,"O_NONBLOCK = %d",O_NONBLOCK & flags);
flags &= ~O_NONBLOCK; // Want Blocking!
int fcntlstat = fcntl(tun_fd,F_SETFL,flags);
MGWARN("ggsn: WARNING: Turning off tun_fd blocking flag, fcntl=%d",fcntlstat);
}
}
// We can just read from the tunnel.
int ret = read(tun_fd,recvbuf,ggConfig.mgMaxPduSize);
if (ret < 0) {
MGERROR("ggsn: error: reading from tunnel: %s", strerror(errno));
//*error = ret;
return NULL;
} else if (ret == 0) {
MGERROR("ggsn: error: zero bytes reading from tunnel: %s", strerror(errno));
//*error = ret; // huh?
return NULL;
} else {
struct iphdr *iph = (struct iphdr*)recvbuf;
{
char infobuf[200];
MGINFO("ggsn: received %s at %s",packettoa(infobuf,recvbuf,ret), timestr().c_str());
//MGLOGF("ggsn: received proto=%s %d byte npdu from %s for %s at %s",
//ip_proto_name(iph->protocol), ret,
//ip_ntoa(iph->saddr,nbuf),
//ip_ntoa(iph->daddr,NULL), timestr());
}
*dstaddr = iph->daddr;
// TODO: Do we have to allocate a new buffer?
*plen = ret;
// Zero terminate for the convenience of the pinger.
recvbuf[ret] = 0;
return recvbuf;
}
}
// If this is a duplicate TCP packet, throw it away.
// The MS is so slow to respond that the servers often send dups
// which are unnecessary because we have reliable communication between here
// and the MS, so just toss them.
// Update 3-2012: Always do the check to print messages for dup packets even if not discarded.
static int mg_toss_dup_packet(mg_con_t*mgp,unsigned char *packet, int packetlen)
{
struct iphdr *iph = (struct iphdr*)packet;
if (iph->protocol != IPPROTO_TCP) { return 0; }
struct tcphdr *tcph = (struct tcphdr*) (packet + 4 * iph->ihl);
if (tcph->rst | tcph->urg) { return 0; }
int i;
for (i = 0; i < MG_PACKET_HISTORY; i++) {
// 3-2012: Jpegs are not going through the system properly.
// I am adding some more checks here to see if we are tossing packets inappropriately.
// The tot_len includes headers, but if they are not the same in the duplicate packet, oh well.
// TODO: If the connection is reset we should zero out our history.
if (mgp->mg_packets[i].saddr == iph->saddr &&
mgp->mg_packets[i].daddr == iph->daddr &&
mgp->mg_packets[i].totlen == iph->tot_len &&
//mgp->mg_packets[i].ipfragoff == iph->frag_off &&
//mgp->mg_packets[i].ipid == iph->id &&
mgp->mg_packets[i].seq == tcph->seq &&
mgp->mg_packets[i].source == tcph->source &&
mgp->mg_packets[i].dest == tcph->dest
) {
const char *what = ggConfig.mgIpTossDup ? "discarding " : "";
char buf1[40],buf2[40];
MGINFO("ggsn: %sduplicate %d byte packet seq=%d frag=%d id=%d src=%s:%d dst=%s:%d",what,
packetlen,tcph->seq,iph->frag_off,iph->id,
ip_ntoa(iph->saddr,buf1),tcph->source,
ip_ntoa(iph->daddr,buf2),tcph->dest);
return ggConfig.mgIpTossDup; // Toss duplicate tcp packet if option set.
}
}
i = mgp->mg_oldest_packet;
if (++mgp->mg_oldest_packet >= MG_PACKET_HISTORY) { mgp->mg_oldest_packet = 0; }
mgp->mg_packets[i].saddr = iph->saddr;
mgp->mg_packets[i].daddr = iph->daddr;
mgp->mg_packets[i].totlen = iph->tot_len;
//mgp->mg_packets[i].ipfragoff = iph->frag_off;
//mgp->mg_packets[i].ipid = iph->id;
mgp->mg_packets[i].seq = tcph->seq;
mgp->mg_packets[i].source = tcph->source;
mgp->mg_packets[i].dest = tcph->dest;
return 0; // Do not toss.
}
// There is data available on the socket. Go get it.
// see handle_nsip_read()
void miniggsn_handle_read()
{
int packetlen;
uint32_t dstaddr;
unsigned char *packet = miniggsn_rcv_npdu(&packetlen, &dstaddr);
if (!packet) { return; }
// We need to reassociate the packet with the PdpContext to which it belongs.
mg_con_t *mgp = mg_con_find_by_ip(dstaddr);
if (mgp == NULL || mgp->mg_pdp == NULL) {
MGERROR("ggsn: error: cannot find PDP context for incoming packet for IP dstaddr=%s",
ip_ntoa(dstaddr,NULL));
return; // -1;
}
if (mg_toss_dup_packet(mgp,packet,packetlen)) { return; }
PdpContext *pdp = mgp->mg_pdp;
//MGDEBUG(2,"miniggsn_handle_read pdp=%p",pdp);
pdp->pdpWriteHighSide(packet,packetlen);
}
// The npdu is a raw packet including the ip header.
int miniggsn_snd_npdu_by_mgc(mg_con_t *mgp,unsigned char *npdu, unsigned len)
{
// Verify the IP header.
struct iphdr *ipheader = (struct iphdr*)npdu;
// The return address must be the MS itself.
uint32_t ms_ip_address = mgp->mg_ip;
uint32_t packet_source_ip_addr = ipheader->saddr;
uint32_t packet_dest_ip_addr = ipheader->daddr;
char infobuf[200];
MGINFO("ggsn: writing %s at %s",packettoa(infobuf,npdu,len),timestr().c_str());
//MGLOGF("ggsn: writing proto=%s %d byte npdu to %s from %s at %s",
//ip_proto_name(ipheader->protocol),
//len,ip_ntoa(packet_dest_ip_addr,NULL),
//ip_ntoa(packet_source_ip_addr,nbuf), timestr().c_str());
#define MUST_HAVE(assertion) \
if (! (assertion)) { MGERROR("ggsn: Packet failed test, discarded: %s",#assertion); return -1; }
if (mg_debug_level > 2) ip_hdr_dump(npdu,"npdu");
MUST_HAVE(ipheader->version == 4); // 4 as in IPv4
MUST_HAVE(ipheader->ihl >= 5); // Minimum header length is 5 words.
int checksum = ip_checksum(ipheader,sizeof(*ipheader),NULL);
MUST_HAVE(checksum == 0); // If fails, packet is bad.
MUST_HAVE(ipheader->ttl > 0); // Time to live - how many hops allowed.
// The blackberry sends ICMP packets, so we better support.
// I'm just going to allow any protocol through.
//MUST_HAVE(ipheader->protocol == IPPROTO_TCP ||
// ipheader->protocol == IPPROTO_UDP ||
// ipheader->protocol == IPPROTO_ICMP);
MUST_HAVE(packet_source_ip_addr == ms_ip_address);
#if OLD_FIREWALL
// The destination address may not be a local address on this machine
// as configured by the operator.
// Note these are all in network order, so be careful.
//uint32_t local_ip_addr = inet_addr(mg_base_ip_str); // probably "192.168.99.1"
uint32_t net_mask = inet_addr(mg_net_mask); // probably "255.255.255.0"
MUST_HAVE((packet_dest_ip_addr & net_mask) != (local_ip_addr & net_mask));
#endif
for (GgsnFirewallRule *rp = gFirewallRules; rp; rp = rp->next) {
// 12-17: Change the message to indicate that this was a firewall rule violation.
//MUST_HAVE((packet_dest_ip_addr & rp->ipMasknl) != (rp->ipBasenl & rp->ipMasknl));
if (! ((packet_dest_ip_addr & rp->ipMasknl) != (rp->ipBasenl & rp->ipMasknl)) ) {
char ipaddrbuf[50]; ip_ntoa(packet_dest_ip_addr,ipaddrbuf);
MGERROR("ggsn: Packet wth dest ip = %s discarded by firewall",ipaddrbuf);
return -1;
}
}
// Decrement ttl and recompute checksum. We are doing this in place.
ipheader->ttl--;
ipheader->check = 0;
//ipheader->check = htons(ip_checksum(ipheader,sizeof(*ipheader),NULL));
ipheader->check = ip_checksum(ipheader,sizeof(*ipheader),NULL);
// Just write to the MS-side tunnel device.
int result = write(tun_fd,npdu,len);
if (result != (int) len) {
MGERROR("ggsn: error: write(tun_fd,%d) result=%d %s",len,result,strerror(errno));
}
return 0;
}
#if 0 // not needed
// Route an n-pdu from the MS out to the internet.
// Called by SNDCP when it has received/re-assembled a N-PDU
int miniggsn_snd_npdu(PdpContext *pctx,unsigned char *npdu, unsigned len)
{
// Find the fd from the pctx; We should put this in the pdp_ctx.
mg_con_t *mgp = mg_con_find_by_ctx(pctx);
if (mgp == NULL) { return -1; } // Whoops
return miniggsn_snd_npdu_by_mgc(mgp, npdu, len);
}
#endif
time_t gGgsnInitTime;
bool miniggsn_init()
{
static int initstatus = -1; // -1: uninited; 0:init failed; 1: init succeeded.
if (initstatus >= 0) {return initstatus;}
initstatus = 0; // assume failure.
// We init config options at GGSN startup.
// They cannot be changed while running.
// To change an option, you would have to stop and restart the GGSN.
ggConfig.mgIpTimeout = gConfig.getNum("GGSN.IP.ReuseTimeout");
ggConfig.mgMaxPduSize = gConfig.getNum("GGSN.IP.MaxPacketSize");
ggConfig.mgMaxConnections = gConfig.getNum("GGSN.MS.IP.MaxCount");
ggConfig.mgIpTossDup = gConfig.getBool("GGSN.IP.TossDuplicatePackets");
string logfile = gConfig.getStr("GGSN.Logfile.Name");
if (logfile.length()) {
mg_log_fp = fopen(logfile.c_str(),"w");
if (mg_log_fp == 0) {
MGERROR("could not open %s log file:%s","GGSN.Logfile.Name",logfile.c_str());
}
}
// This is the first message in the newly opened file.
time(&gGgsnInitTime);
MGINFO("Initializing Mini GGSN %s",ctime(&gGgsnInitTime)); // ctime includes a newline.
if (mg_log_fp) {
mg_debug_level = 1;
MGINFO("GGSN logging to file %s",logfile.c_str());
}
if (ggConfig.mgMaxConnections > 254) {
MGERROR("GGSN.MS.IP.MaxCount specifies too many connections (%d) specifed, using 254",
ggConfig.mgMaxConnections);
ggConfig.mgMaxConnections = 254;
}
// We need three IP things:
// 1. the route expressed using "/maskbits" notation,
// 2. the base ip address,
// 3. the mask for the MS (which has very little to do with the netmask of the host we are running on.)
// All three can be derived from the ipRoute, if specfied.
// But conceivably the user might want to start their base ip address elsewhere.
const char *ip_base_str = gConfig.getStr("GGSN.MS.IP.Base").c_str();
uint32_t mgIpBasenl = inet_addr(ip_base_str);
if (mgIpBasenl == INADDR_NONE) {
MGERROR("miniggn: GGSN.MS.IP.Base address invalid:%s",ip_base_str);
return false;
}
if ((ntohl(mgIpBasenl) & 0xff) == 0) {
MGERROR("miniggn: GGSN.MS.IP.Base address should not end in .0 but proceeding anyway: %s",ip_base_str);
}
const char *route_str = 0;
char route_buf[40];
string route_save;
if (gConfig.defines("GGSN.MS.IP.Route")) {
route_save = gConfig.getStr("GGSN.MS.IP.Route");
route_str = route_save.c_str();
}
uint32_t route_basenl, route_masknl;
if (route_str && *route_str && *route_str != ' ') {
if (strlen(route_str) > strlen("aaa.bbb.ccc.ddd/yy") + 2) { // add some slop.
MGWARN("miniggn: GGSN.MS.IP.Route address is too long:%s",route_str);
// but use it anyway.
}
if (! ip_addr_crack(route_str,&route_basenl,&route_masknl) || route_basenl == INADDR_NONE) {
MGWARN("miniggsn: GGSN.MS.IP.Route is not a valid ip address: %s",route_str);
// but use it anyway.
}
if (route_masknl == 0) {
MGWARN("miniggsn: GGSN.MS.IP.Route is not a valid route, /mask part missing or invalid: %sn",
route_str);
// but use it anyway.
}
// We would like to check that the base ip is within the ip route range,
// which is tricky, but check the most common case:
if ((route_basenl&route_masknl) != (mgIpBasenl&route_masknl)) {
MGWARN("miniggsn: GGSN.MS.IP.Base = %s ip address does not appear to be in range of GGSN.MS.IP.Route = %s",
ip_base_str, route_str);
// but use it anyway.
}
} else {
// Manufacture a route string. Assume route is 24 bits.
route_masknl = inet_addr("255.255.255.0");
route_basenl = mgIpBasenl & route_masknl; // Set low byte to 0.
ip_ntoa(route_basenl,route_buf);
strcat(route_buf,"/24");
route_str = route_buf;
}
// Firewall rules:
bool firewall_enable;
if ((firewall_enable = gConfig.getNum("GGSN.Firewall.Enable"))) {
// Block anything in the routed range:
addFirewallRule(route_basenl,route_masknl);
// Block local loopback:
uint32_t tmp_basenl,tmp_masknl;
if (ip_addr_crack("127.0.0.1/24",&tmp_basenl,&tmp_masknl)) {
addFirewallRule(tmp_basenl,tmp_masknl);
}
// Block the OpenBTS station itself:
uint32_t *myaddrs = ip_findmyaddr();
for ( ; *myaddrs != (unsigned)-1; myaddrs++) {
addFirewallRule(*myaddrs,0xffffffff);
}
if (firewall_enable >= 2) {
// Block all private addresses:
// 16-bit block (/16 prefix, 256 × C) 192.168.0.0 192.168.255.255 65536
uint32_t private_addrnl = inet_addr("192.168.0.0");
uint32_t private_masknl = inet_addr("255.255.0.0");
addFirewallRule(private_addrnl,private_masknl);
// 20-bit block (/12 prefix, 16 × B) 172.16.0.0 172.31.255.255 1048576
private_addrnl = inet_addr("172.16.0.0");
private_masknl = inet_addr("255.240.0.0");
addFirewallRule(private_addrnl,private_masknl);
// 24-bit block (/8 prefix, 1 × A) 10.0.0.0 10.255.255.255 16777216
private_addrnl = inet_addr("10.0.0.0");
private_masknl = inet_addr("255.0.0.0");
addFirewallRule(private_addrnl,private_masknl);
}
}
MGINFO("GGSN Configuration:");
MGINFO(" GGSN.MS.IP.Base=%s", ip_ntoa(mgIpBasenl,NULL));
MGINFO(" GGSN.MS.IP.MaxCount=%d", ggConfig.mgMaxConnections);
MGINFO(" GGSN.MS.IP.Route=%s", route_str);
MGINFO(" GGSN.IP.MaxPacketSize=%d", ggConfig.mgMaxPduSize);
MGINFO(" GGSN.IP.ReuseTimeout=%d", ggConfig.mgIpTimeout);
MGINFO(" GGSN.Firewall.Enable=%d", firewall_enable);
MGINFO(" GGSN.IP.TossDuplicatePackets=%d", ggConfig.mgIpTossDup);
if (firewall_enable) {
MGINFO("GGSN Firewall Rules:");
for (GgsnFirewallRule *rp = gFirewallRules; rp; rp = rp->next) {
char buf1[40], buf2[40];
MGINFO(" block ip=%s mask=%s",ip_ntoa(rp->ipBasenl,buf1),ip_ntoa(rp->ipMasknl,buf2));
}
}
uint32_t dns[2]; // We dont use the result, we just want to print out the DNS servers now.
ip_finddns(dns); // The dns servers are polled again later.
const char *tun_if_name = gConfig.getStr("GGSN.TunName").c_str();
if (tun_fd == -1) {
ip_init();
tun_fd = ip_tun_open(tun_if_name,route_str);
if (tun_fd < 0) {
MGERROR("ggsn: ERROR: Could not open tun device %s",tun_if_name);
LOG(ALERT) << "Cound not open tun device:"<<tun_if_name; // TEMPORARY MESSAGE
return false;
}
}
// DEBUG: Try it again.
//printf("DEBUG: Opening tunnel again: %d\n",ip_tun_open(tun_if_name,route_str));
if (mg_cons) free(mg_cons);
mg_cons = (mg_con_t*)calloc(ggConfig.mgMaxConnections,sizeof(mg_con_t));
if (mg_cons == 0) {
MGERROR("ggsn: ERROR: out of memory");
return false;
}
//memset(mg_cons,0,sizeof(mg_cons));
uint32_t base_iphl = ntohl(mgIpBasenl);
// 8-15: no dont do this. It subverts the purpose of the BASE ip address.
//base_iphl &= ~255; // In case they specify 192.168.2.1, make it 192.168.2.0
int i;
// If the last digit is 0 (192.168.99.0), change it to 1 for the first IP addr served.
if ((base_iphl & 255) == 0) { base_iphl++; }
for (i=0; i < ggConfig.mgMaxConnections; i++) {
mg_cons[i].mg_ip = htonl(base_iphl + i);
//mg_cons[i].mg_ip = htonl(base_iphl + 1 + i);
// DEBUG!!!!! Use my own ip address.
//mg_cons[i].mg_ip = inet_addr("192.168.1.99");
//printf("adding IP=%s\n",ip_ntoa(mg_cons[i].mg_ip,NULL));
}
initstatus = 1;
return initstatus;
}
}; // namespace
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