Modules/IPStack/udp.c

   1 /*
   2  * Acess2 IP Stack
   3  * - UDP Handling
   4  */
   5 #include "ipstack.h"
   6 #include <tpl_drv_common.h>
   7 #include "udp.h"
   8
   9 #define UDP_ALLOC_BASE  0xC000
  10
  11 // === PROTOTYPES ===
  12 void    UDP_Initialise();
  13 void    UDP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer);
  14 void    UDP_Unreachable(tInterface *Interface, int Code, void *Address, int Length, void *Buffer);
  15 void    UDP_SendPacketTo(tUDPChannel *Channel, int AddrType, void *Address, Uint16 Port, void *Data, size_t Length);
  16 // --- Client Channels
  17 tVFS_Node       *UDP_Channel_Init(tInterface *Interface);
  18 Uint64  UDP_Channel_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer);
  19 Uint64  UDP_Channel_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer);
  20  int    UDP_Channel_IOCtl(tVFS_Node *Node, int ID, void *Data);
  21 void    UDP_Channel_Close(tVFS_Node *Node);
  22 // --- Helpers
  23 Uint16  UDP_int_AllocatePort();
  24  int    UDP_int_MarkPortAsUsed(Uint16 Port);
  25 void    UDP_int_FreePort(Uint16 Port);
  26
  27 // === GLOBALS ===
  28 tMutex  glUDP_Channels;
  29 tUDPChannel     *gpUDP_Channels;
  30
  31 tMutex  glUDP_Ports;
  32 Uint32  gUDP_Ports[0x10000/32];
  33
  34 tSocketFile     gUDP_SocketFile = {NULL, "udp", UDP_Channel_Init};
  35
  36 // === CODE ===
  37 /**
  38  * \fn void TCP_Initialise()
  39  * \brief Initialise the TCP Layer
  40  */
  41 void UDP_Initialise()
  42 {
  43         IPStack_AddFile(&gUDP_SocketFile);
  44         //IPv4_RegisterCallback(IP4PROT_UDP, UDP_GetPacket, UDP_Unreachable);
  45         IPv4_RegisterCallback(IP4PROT_UDP, UDP_GetPacket);
  46 }
  47
  48 /**
  49  * \brief Scan a list of tUDPChannels and find process the first match
  50  * \return 0 if no match was found, -1 on error and 1 if a match was found
  51  */
  52 int UDP_int_ScanList(tUDPChannel *List, tInterface *Interface, void *Address, int Length, void *Buffer)
  53 {
  54         tUDPHeader      *hdr = Buffer;
  55         tUDPChannel     *chan;
  56         tUDPPacket      *pack;
  57          int    len;
  58
  59         for(chan = List;
  60                 chan;
  61                 chan = chan->Next)
  62         {
  63                 // Match local endpoint
  64                 if(chan->Interface && chan->Interface != Interface)     continue;
  65                 if(chan->LocalPort != ntohs(hdr->DestPort))     continue;
  66
  67                 // Check for remote port restriction
  68                 if(chan->Remote.Port && chan->Remote.Port != ntohs(hdr->SourcePort))
  69                         continue;
  70                 // Check for remote address restriction
  71                 if(chan->RemoteMask)
  72                 {
  73                         if(chan->Remote.AddrType != Interface->Type)    continue;
  74                         if(!IPStack_CompareAddress(Interface->Type, Address,
  75                                 &chan->Remote.Addr, chan->RemoteMask)
  76                                 )
  77                                 continue;
  78                 }
  79
  80                 Log_Log("UDP", "Recieved packet for %p", chan);
  81                 // Create the cached packet
  82                 len = ntohs(hdr->Length);
  83                 pack = malloc(sizeof(tUDPPacket) + len);
  84                 pack->Next = NULL;
  85                 memcpy(&pack->Remote.Addr, Address, IPStack_GetAddressSize(Interface->Type));
  86                 pack->Remote.Port = ntohs(hdr->SourcePort);
  87                 pack->Length = len;
  88                 memcpy(pack->Data, hdr->Data, len);
  89
  90                 // Add the packet to the channel's queue
  91                 SHORTLOCK(&chan->lQueue);
  92                 if(chan->Queue)
  93                         chan->QueueEnd->Next = pack;
  94                 else
  95                         chan->QueueEnd = chan->Queue = pack;
  96                 SHORTREL(&chan->lQueue);
  97                 Mutex_Release(&glUDP_Channels);
  98                 return 1;
  99         }
 100         return 0;
 101 }
 102
 103 /**
 104  * \fn void UDP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 105  * \brief Handles a packet from the IP Layer
 106  */
 107 void UDP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 108 {
 109         tUDPHeader      *hdr = Buffer;
 110
 111         Log_Debug("UDP", "hdr->SourcePort = %i", ntohs(hdr->SourcePort));
 112         Log_Debug("UDP", "hdr->DestPort = %i", ntohs(hdr->DestPort));
 113         Log_Debug("UDP", "hdr->Length = %i", ntohs(hdr->Length));
 114         Log_Debug("UDP", "hdr->Checksum = 0x%x", ntohs(hdr->Checksum));
 115
 116         // Check registered connections
 117         Mutex_Acquire(&glUDP_Channels);
 118         UDP_int_ScanList(gpUDP_Channels, Interface, Address, Length, Buffer);
 119         Mutex_Release(&glUDP_Channels);
 120 }
 121
 122 /**
 123  * \brief Handle an ICMP Unrechable Error
 124  */
 125 void UDP_Unreachable(tInterface *Interface, int Code, void *Address, int Length, void *Buffer)
 126 {
 127
 128 }
 129
 130 /**
 131  * \brief Send a packet
 132  * \param Channel       Channel to send the packet from
 133  * \param Data  Packet data
 134  * \param Length        Length in bytes of packet data
 135  */
 136 void UDP_SendPacketTo(tUDPChannel *Channel, int AddrType, void *Address, Uint16 Port, void *Data, size_t Length)
 137 {
 138         tUDPHeader      *hdr;
 139
 140         if(Channel->Interface && Channel->Interface->Type != AddrType)  return ;
 141
 142         switch(AddrType)
 143         {
 144         case 4:
 145                 // Create the packet
 146                 hdr = malloc(sizeof(tUDPHeader)+Length);
 147                 hdr->SourcePort = htons( Channel->LocalPort );
 148                 hdr->DestPort = htons( Port );
 149                 hdr->Length = htons( sizeof(tUDPHeader) + Length );
 150                 hdr->Checksum = 0;      // Checksum can be zero on IPv4
 151                 memcpy(hdr->Data, Data, Length);
 152                 // Pass on the the IPv4 Layer
 153                 // TODO: What if Channel->Interface is NULL here?
 154                 IPv4_SendPacket(Channel->Interface, *(tIPv4*)Address, IP4PROT_UDP, 0, sizeof(tUDPHeader)+Length, hdr);
 155                 // Free allocated packet
 156                 free(hdr);
 157                 break;
 158         }
 159 }
 160
 161 // --- Client Channels
 162 tVFS_Node *UDP_Channel_Init(tInterface *Interface)
 163 {
 164         tUDPChannel     *new;
 165         new = calloc( sizeof(tUDPChannel), 1 );
 166         new->Interface = Interface;
 167         new->Node.ImplPtr = new;
 168         new->Node.NumACLs = 1;
 169         new->Node.ACLs = &gVFS_ACL_EveryoneRW;
 170         new->Node.Read = UDP_Channel_Read;
 171         new->Node.Write = UDP_Channel_Write;
 172         new->Node.IOCtl = UDP_Channel_IOCtl;
 173         new->Node.Close = UDP_Channel_Close;
 174
 175         Mutex_Acquire(&glUDP_Channels);
 176         new->Next = gpUDP_Channels;
 177         gpUDP_Channels = new;
 178         Mutex_Release(&glUDP_Channels);
 179
 180         return &new->Node;
 181 }
 182
 183 /**
 184  * \brief Read from the channel file (wait for a packet)
 185  */
 186 Uint64 UDP_Channel_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
 187 {
 188         tUDPChannel     *chan = Node->ImplPtr;
 189         tUDPPacket      *pack;
 190         tUDPEndpoint    *ep;
 191          int    ofs;
 192
 193         if(chan->LocalPort == 0)        return 0;
 194
 195         while(chan->Queue == NULL)      Threads_Yield();
 196
 197         for(;;)
 198         {
 199                 VFS_SelectNode(Node, VFS_SELECT_READ, NULL, "UDP_Channel_Read");
 200                 SHORTLOCK(&chan->lQueue);
 201                 if(chan->Queue == NULL) {
 202                         SHORTREL(&chan->lQueue);
 203                         continue;
 204                 }
 205                 pack = chan->Queue;
 206                 chan->Queue = pack->Next;
 207                 if(!chan->Queue) {
 208                         chan->QueueEnd = NULL;
 209                         VFS_MarkAvaliable(Node, 0);     // Nothing left
 210                 }
 211                 SHORTREL(&chan->lQueue);
 212                 break;
 213         }
 214
 215         // Check that the header fits
 216         ep = Buffer;
 217         ofs = 4 + IPStack_GetAddressSize(pack->Remote.AddrType);
 218         if(Length < ofs) {
 219                 free(pack);
 220                 return 0;
 221         }
 222
 223         // Fill header
 224         ep->Port = pack->Remote.Port;
 225         ep->AddrType = pack->Remote.AddrType;
 226         memcpy(&ep->Addr, &pack->Remote.Addr, IPStack_GetAddressSize(pack->Remote.AddrType));
 227
 228         // Copy packet data
 229         if(Length > ofs + pack->Length) Length = ofs + pack->Length;
 230         memcpy((char*)Buffer + ofs, pack->Data, Length - ofs);
 231
 232         // Free cached packet
 233         free(pack);
 234
 235         return Length;
 236 }
 237
 238 /**
 239  * \brief Write to the channel file (send a packet)
 240  */
 241 Uint64 UDP_Channel_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
 242 {
 243         tUDPChannel     *chan = Node->ImplPtr;
 244         tUDPEndpoint    *ep;
 245         void    *data;
 246          int    ofs;
 247         if(chan->LocalPort == 0)        return 0;
 248
 249         ep = Buffer;
 250         ofs = 2 + 2 + IPStack_GetAddressSize( ep->AddrType );
 251
 252         data = (char*)Buffer + ofs;
 253
 254         UDP_SendPacketTo(chan, ep->AddrType, &ep->Addr, ep->Port, Buffer, (size_t)Length - ofs);
 255
 256         return 0;
 257 }
 258
 259 /**
 260  * \brief Names for channel IOCtl Calls
 261  */
 262 static const char *casIOCtls_Channel[] = {
 263         DRV_IOCTLNAMES,
 264         "getset_localport",
 265         "getset_remoteport",
 266         "set_remotemask",
 267         "set_remoteaddr",
 268         NULL
 269         };
 270 /**
 271  * \brief Channel IOCtls
 272  */
 273 int UDP_Channel_IOCtl(tVFS_Node *Node, int ID, void *Data)
 274 {
 275         tUDPChannel     *chan = Node->ImplPtr;
 276         ENTER("pNode iID pData", Node, ID, Data);
 277         switch(ID)
 278         {
 279         BASE_IOCTLS(DRV_TYPE_MISC, "UDP Channel", 0x100, casIOCtls_Channel);
 280
 281         case 4: // getset_localport (returns bool success)
 282                 if(!Data)       LEAVE_RET('i', chan->LocalPort);
 283                 if(!CheckMem( Data, sizeof(Uint16) ) ) {
 284                         LOG("Invalid pointer %p", Data);
 285                         LEAVE_RET('i', -1);
 286                 }
 287                 // Set port
 288                 chan->LocalPort = *(Uint16*)Data;
 289                 // Permissions check (Ports lower than 1024 are root-only)
 290                 if(chan->LocalPort != 0 && chan->LocalPort < 1024) {
 291                         if( Threads_GetUID() != 0 ) {
 292                                 LOG("Attempt by non-superuser to listen on port %i", chan->LocalPort);
 293                                 chan->LocalPort = 0;
 294                                 LEAVE_RET('i', -1);
 295                         }
 296                 }
 297                 // Allocate a random port if requested
 298                 if( chan->LocalPort == 0 )
 299                         chan->LocalPort = UDP_int_AllocatePort();
 300                 else
 301                 {
 302                         // Else, mark the requested port as used
 303                         if( UDP_int_MarkPortAsUsed(chan->LocalPort) == 0 ) {
 304                                 LOG("Port %i us currently in use", chan->LocalPort);
 305                                 chan->LocalPort = 0;
 306                                 LEAVE_RET('i', 0);
 307                         }
 308                         LEAVE_RET('i', 1);
 309                 }
 310                 LEAVE_RET('i', 1);
 311
 312         case 5: // getset_remoteport (returns bool success)
 313                 if(!Data)       LEAVE_RET('i', chan->Remote.Port);
 314                 if(!CheckMem( Data, sizeof(Uint16) ) ) {
 315                         LOG("Invalid pointer %p", Data);
 316                         LEAVE_RET('i', -1);
 317                 }
 318                 chan->Remote.Port = *(Uint16*)Data;
 319                 return 1;
 320
 321         case 6: // getset_remotemask (returns bool success)
 322                 if(!Data)       LEAVE_RET('i', chan->RemoteMask);
 323                 if(!CheckMem(Data, sizeof(int)))        LEAVE_RET('i', -1);
 324                 if( !chan->Interface ) {
 325                         LOG("Can't set remote mask on NULL interface");
 326                         LEAVE_RET('i', -1);
 327                 }
 328                 if( *(int*)Data > IPStack_GetAddressSize(chan->Interface->Type) )
 329                         LEAVE_RET('i', -1);
 330                 chan->RemoteMask = *(int*)Data;
 331                 return 1;
 332
 333         case 7: // set_remoteaddr (returns bool success)
 334                 if( !chan->Interface ) {
 335                         LOG("Can't set remote address on NULL interface");
 336                         LEAVE_RET('i', -1);
 337                 }
 338                 if(!CheckMem(Data, IPStack_GetAddressSize(chan->Interface->Type))) {
 339                         LOG("Invalid pointer");
 340                         LEAVE_RET('i', -1);
 341                 }
 342                 memcpy(&chan->Remote.Addr, Data, IPStack_GetAddressSize(chan->Interface->Type));
 343                 return 0;
 344         }
 345         LEAVE_RET('i', 0);
 346 }
 347
 348 /**
 349  * \brief Close and destroy an open channel
 350  */
 351 void UDP_Channel_Close(tVFS_Node *Node)
 352 {
 353         tUDPChannel     *chan = Node->ImplPtr;
 354         tUDPChannel     *prev;
 355
 356         // Remove from the main list first
 357         Mutex_Acquire(&glUDP_Channels);
 358         if(gpUDP_Channels == chan)
 359                 gpUDP_Channels = gpUDP_Channels->Next;
 360         else
 361         {
 362                 for(prev = gpUDP_Channels;
 363                         prev->Next && prev->Next != chan;
 364                         prev = prev->Next);
 365                 if(!prev->Next)
 366                         Log_Warning("UDP", "Bookeeping Fail, channel %p is not in main list", chan);
 367                 else
 368                         prev->Next = prev->Next->Next;
 369         }
 370         Mutex_Release(&glUDP_Channels);
 371
 372         // Clear Queue
 373         SHORTLOCK(&chan->lQueue);
 374         while(chan->Queue)
 375         {
 376                 tUDPPacket      *tmp;
 377                 tmp = chan->Queue;
 378                 chan->Queue = tmp->Next;
 379                 free(tmp);
 380         }
 381         SHORTREL(&chan->lQueue);
 382
 383         // Free channel structure
 384         free(chan);
 385 }
 386
 387 /**
 388  * \return Port Number on success, or zero on failure
 389  */
 390 Uint16 UDP_int_AllocatePort()
 391 {
 392          int    i;
 393         Mutex_Acquire(&glUDP_Ports);
 394         // Fast Search
 395         for( i = UDP_ALLOC_BASE; i < 0x10000; i += 32 )
 396                 if( gUDP_Ports[i/32] != 0xFFFFFFFF )
 397                         break;
 398         if(i == 0x10000)        return 0;
 399         for( ;; i++ )
 400         {
 401                 if( !(gUDP_Ports[i/32] & (1 << (i%32))) )
 402                         return i;
 403         }
 404         Mutex_Release(&glUDP_Ports);
 405 }
 406
 407 /**
 408  * \brief Allocate a specific port
 409  * \return Boolean Success
 410  */
 411 int UDP_int_MarkPortAsUsed(Uint16 Port)
 412 {
 413         Mutex_Acquire(&glUDP_Ports);
 414         if( gUDP_Ports[Port/32] & (1 << (Port%32)) ) {
 415                 return 0;
 416                 Mutex_Release(&glUDP_Ports);
 417         }
 418         gUDP_Ports[Port/32] |= 1 << (Port%32);
 419         Mutex_Release(&glUDP_Ports);
 420         return 1;
 421 }
 422
 423 /**
 424  * \brief Free an allocated port
 425  */
 426 void UDP_int_FreePort(Uint16 Port)
 427 {
 428         Mutex_Acquire(&glUDP_Ports);
 429         gUDP_Ports[Port/32] &= ~(1 << (Port%32));
 430         Mutex_Release(&glUDP_Ports);
 431 }