src/connection.cpp

   1 #include <connection.h>
   2 #include <unistd.h>
   3 #include <fcntl.h>
   4 #include <sys/errno.h>
   5 #include <sys/ioctl.h>
   6 #include <sys/utsname.h>
   7 #include <errno.h>
   8 #include <vector>
   9 #include "inspircd.h"
  10 #include "modules.h"
  11
  12 extern std::vector<Module*> modules;
  13 extern std::vector<ircd_module*> factory;
  14
  15 extern int MODCOUNT;
  16
  17 #define STATE_CLEAR 1
  18 #define STATE_WAIT_FOR_ACK 2
  19
  20 packet::packet()
  21 {
  22         srand(time(NULL));
  23         id = random();
  24 }
  25
  26 packet::~packet()
  27 {
  28 }
  29
  30 connection::connection()
  31 {
  32         key = GenKey();
  33         fd = 0;
  34         state = STATE_CLEAR;
  35         buffer.clear();
  36 }
  37
  38
  39 bool connection::CreateListener(char* host, int p)
  40 {
  41         sockaddr_in host_address;
  42         int flags;
  43         in_addr addy;
  44         int on = 0;
  45         struct linger linger = { 0 };
  46
  47         fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
  48         if (fd <= 0)
  49         {
  50                 return false;
  51         }
  52
  53         memset((void*)&host_address, 0, sizeof(host_address));
  54
  55         host_address.sin_family = AF_INET;
  56
  57         if (!strcmp(host,""))
  58         {
  59                 host_address.sin_addr.s_addr = htonl(INADDR_ANY);
  60         }
  61         else
  62         {
  63                 inet_aton(host,&addy);
  64                 host_address.sin_addr = addy;
  65         }
  66
  67         host_address.sin_port = htons(p);
  68
  69         if (bind(fd,(sockaddr*)&host_address,sizeof(host_address))<0)
  70         {
  71                 return false;
  72         }
  73
  74         // make the socket non-blocking
  75         flags = fcntl(fd, F_GETFL, 0);
  76         fcntl(fd, F_SETFL, flags | O_NONBLOCK);
  77
  78         this->port = p;
  79
  80         setsockopt(fd,SOL_SOCKET,SO_REUSEADDR,(const char*)&on,sizeof(on));
  81         linger.l_onoff = 1;
  82         linger.l_linger = 0;
  83         setsockopt(fd,SOL_SOCKET,SO_LINGER,(const char*)&linger,sizeof(linger));
  84
  85         buffer.clear();
  86
  87         return true;
  88 }
  89
  90 bool connection::BeginLink(char* targethost, int port, char* password)
  91 {
  92         char connect[MAXBUF];
  93
  94         if (this->fd)
  95         {
  96                 sprintf(connect,"S %s %s :%s",getservername().c_str(),password,getserverdesc().c_str());
  97                 this->haspassed = false;
  98                 return this->SendPacket(connect, targethost, port, 0);
  99         }
 100         return false;
 101 }
 102
 103 // targethost: in dot notation a.b.c.d
 104 void connection::TerminateLink(char* targethost)
 105 {
 106 }
 107
 108 // host: in dot notation a.b.c.d
 109 // port: host byte order
 110 bool connection::SendPacket(char *message, char* host, int port, long ourkey)
 111 {
 112         sockaddr_in host_address;
 113         in_addr addy;
 114         packet p;
 115
 116         memset((void*)&host_address, 0, sizeof(host_address));
 117
 118         host_address.sin_family = AF_INET;
 119         inet_aton(host,&addy);
 120         host_address.sin_addr = addy;
 121
 122         host_address.sin_port = htons(port);
 123
 124         strcpy(p.data,message);
 125         p.type = PT_SYN_WITH_DATA;
 126         p.key = ourkey;
 127
 128
 129         FOREACH_MOD OnPacketTransmit(p.data);
 130
 131         log(DEBUG,"main: Connection::SendPacket() sent '%s' to %s:%d",p.data,host,port);
 132
 133         // returns false if the packet could not be sent (e.g. target host down)
 134         if (sendto(this->fd,&p,sizeof(p),0,(sockaddr*)&host_address,sizeof(host_address))<0)
 135         {
 136                 log(DEBUG,"sendto() failed for Connection::SendPacket() with a packet of size %d: %s",sizeof(p),strerror(errno));
 137                 return false;
 138         }
 139
 140         this->state = STATE_CLEAR;
 141         return true;
 142 }
 143
 144 bool connection::SendSYN(char* host, int port)
 145 {
 146         sockaddr_in host_address;
 147         in_addr addy;
 148         packet p;
 149
 150         memset((void*)&host_address, 0, sizeof(host_address));
 151
 152         host_address.sin_family = AF_INET;
 153         inet_aton(host,&addy);
 154         host_address.sin_addr = addy;
 155
 156         host_address.sin_port = htons(port);
 157
 158         p.type = PT_SYN_ONLY;
 159         p.key = key;
 160         strcpy(p.data,"");
 161
 162         if (sendto(fd,&p,sizeof(p),0,(sockaddr*)&host_address,sizeof(host_address))<0)
 163         {
 164                 return false;
 165         }
 166         return true;
 167
 168 }
 169
 170 bool connection::SendACK(char* host, int port, int reply_id)
 171 {
 172         sockaddr_in host_address;
 173         in_addr addy;
 174         packet p;
 175
 176         memset((void*)&host_address, 0, sizeof(host_address));
 177
 178         host_address.sin_family = AF_INET;
 179         inet_aton(host,&addy);
 180         host_address.sin_addr = addy;
 181
 182         host_address.sin_port = htons(port);
 183
 184         p.type = PT_ACK_ONLY;
 185         p.key = key;
 186         p.id = reply_id;
 187         strcpy(p.data,"");
 188
 189         if (sendto(fd,&p,sizeof(p),0,(sockaddr*)&host_address,sizeof(host_address))<0)
 190         {
 191                 return false;
 192         }
 193
 194 }
 195
 196
 197 // Generates a server key. This is pseudo-random.
 198 // the server always uses the same server-key in all communications
 199 // across the network. All other servers must remember the server key
 200 // of servers in the network, e.g.:
 201 //
 202 // ServerA:  key=5555555555
 203 // ServerB:  key=6666666666
 204 // I am ServerC: key=77777777777
 205 //
 206 // If ServerC sees a packet from ServerA, and the key stored for ServerA
 207 // is 0, then cache the key as the servers key.
 208 // after this point, any packet from ServerA which does not contain its key,
 209 // 555555555, will be silently dropped.
 210 // This should prevent blind spoofing, as to fake a server you must know its
 211 // assigned key, and to do that you must receive messages that are origintated
 212 // from it or hack the running executable.
 213 //
 214 // During the AUTH phase (when server passwords are checked, the key in any
 215 // packet MUST be 0). Only the initial SERVER/PASS packets may have a key
 216 // of 0 (and any ACK responses to them).
 217 //
 218
 219 long connection::GenKey()
 220 {
 221         srand(time(NULL));
 222         return (random()*time(NULL));
 223 }
 224
 225 // host: in dot notation a.b.c.d
 226 // port: host byte order
 227 bool connection::RecvPacket(char *message, char* host, int &prt, long &theirkey)
 228 {
 229         // returns false if no packet waiting for receive, e.g. EAGAIN or ECONNRESET
 230         sockaddr_in host_address;
 231         socklen_t host_address_size;
 232         packet p;
 233
 234         memset((void*)&host_address, 0, sizeof(host_address));
 235
 236         host_address.sin_family=AF_INET;
 237         host_address_size=sizeof(host_address);
 238
 239         //int recvfrom(int s, void *buf, size_t len, int flags, struct sockaddr *from, socklen_t *fromlen);
 240         if (recvfrom(fd,&p,sizeof(p),0,(sockaddr*)&host_address,&host_address_size)<0)
 241         {
 242                 return false;
 243         }
 244
 245         log(DEBUG,"connection::RecvPacket(): received packet type %d '%s' from '%s'",p.type,p.data,inet_ntoa(host_address.sin_addr));
 246
 247         if (p.type == PT_SYN_ONLY)
 248         {
 249                 strcpy(message,p.data);
 250                 strcpy(host,inet_ntoa(host_address.sin_addr));
 251                 prt = ntohs(host_address.sin_port);
 252                 SendACK(host,this->port,p.id);
 253                 return false;
 254         }
 255
 256         if (p.type == PT_ACK_ONLY)
 257         {
 258                 strcpy(message,p.data);
 259                 strcpy(host,inet_ntoa(host_address.sin_addr));
 260                 prt = ntohs(host_address.sin_port);
 261                 this->state = STATE_CLEAR;
 262                 return false;
 263         }
 264
 265         if (p.type == PT_SYN_WITH_DATA)
 266         {
 267                 strcpy(message,p.data);
 268                 strcpy(host,inet_ntoa(host_address.sin_addr));
 269                 theirkey = p.key;
 270                 prt = ntohs(host_address.sin_port); // the port we received it on
 271                 SendACK(host,prt,p.id);
 272                 return true;
 273         }
 274
 275         log(DEBUG,"connection::RecvPacket(): Invalid packet type %d (protocol error)",p.type);
 276         return true;
 277 }
 278