Modules/IPStack/udp.c

   1 /*
   2  * Acess2 IP Stack
   3  * - UDP Handling
   4  */
   5 #include "ipstack.h"
   6 #include <api_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, const void *Address, Uint16 Port, const 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, const 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 tVFS_NodeType   gUDP_NodeType = {
  29         .Read = UDP_Channel_Read,
  30         .Write = UDP_Channel_Write,
  31         .IOCtl = UDP_Channel_IOCtl,
  32         .Close = UDP_Channel_Close
  33 };
  34 tMutex  glUDP_Channels;
  35 tUDPChannel     *gpUDP_Channels;
  36
  37 tMutex  glUDP_Ports;
  38 Uint32  gUDP_Ports[0x10000/32];
  39
  40 tSocketFile     gUDP_SocketFile = {NULL, "udp", UDP_Channel_Init};
  41
  42 // === CODE ===
  43 /**
  44  * \fn void TCP_Initialise()
  45  * \brief Initialise the TCP Layer
  46  */
  47 void UDP_Initialise()
  48 {
  49         IPStack_AddFile(&gUDP_SocketFile);
  50         //IPv4_RegisterCallback(IP4PROT_UDP, UDP_GetPacket, UDP_Unreachable);
  51         IPv4_RegisterCallback(IP4PROT_UDP, UDP_GetPacket);
  52 }
  53
  54 /**
  55  * \brief Scan a list of tUDPChannels and find process the first match
  56  * \return 0 if no match was found, -1 on error and 1 if a match was found
  57  */
  58 int UDP_int_ScanList(tUDPChannel *List, tInterface *Interface, void *Address, int Length, void *Buffer)
  59 {
  60         tUDPHeader      *hdr = Buffer;
  61         tUDPChannel     *chan;
  62         tUDPPacket      *pack;
  63          int    len;
  64
  65         for(chan = List;
  66                 chan;
  67                 chan = chan->Next)
  68         {
  69                 // Match local endpoint
  70                 if(chan->Interface && chan->Interface != Interface)     continue;
  71                 if(chan->LocalPort != ntohs(hdr->DestPort))     continue;
  72
  73                 // Check for remote port restriction
  74                 if(chan->Remote.Port && chan->Remote.Port != ntohs(hdr->SourcePort))
  75                         continue;
  76                 // Check for remote address restriction
  77                 if(chan->RemoteMask)
  78                 {
  79                         if(chan->Remote.AddrType != Interface->Type)
  80                                 continue;
  81                         if(!IPStack_CompareAddress(Interface->Type, Address,
  82                                 &chan->Remote.Addr, chan->RemoteMask)
  83                                 )
  84                                 continue;
  85                 }
  86
  87                 Log_Log("UDP", "Recieved packet for %p", chan);
  88                 // Create the cached packet
  89                 len = ntohs(hdr->Length);
  90                 pack = malloc(sizeof(tUDPPacket) + len);
  91                 pack->Next = NULL;
  92                 memcpy(&pack->Remote.Addr, Address, IPStack_GetAddressSize(Interface->Type));
  93                 pack->Remote.Port = ntohs(hdr->SourcePort);
  94                 pack->Length = len;
  95                 memcpy(pack->Data, hdr->Data, len);
  96
  97                 // Add the packet to the channel's queue
  98                 SHORTLOCK(&chan->lQueue);
  99                 if(chan->Queue)
 100                         chan->QueueEnd->Next = pack;
 101                 else
 102                         chan->QueueEnd = chan->Queue = pack;
 103                 SHORTREL(&chan->lQueue);
 104                 VFS_MarkAvaliable(&chan->Node, 1);
 105                 Mutex_Release(&glUDP_Channels);
 106                 return 1;
 107         }
 108         return 0;
 109 }
 110
 111 /**
 112  * \fn void UDP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 113  * \brief Handles a packet from the IP Layer
 114  */
 115 void UDP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 116 {
 117         tUDPHeader      *hdr = Buffer;
 118
 119         Log_Debug("UDP", "hdr->SourcePort = %i", ntohs(hdr->SourcePort));
 120         Log_Debug("UDP", "hdr->DestPort = %i", ntohs(hdr->DestPort));
 121         Log_Debug("UDP", "hdr->Length = %i", ntohs(hdr->Length));
 122         Log_Debug("UDP", "hdr->Checksum = 0x%x", ntohs(hdr->Checksum));
 123
 124         // Check registered connections
 125         Mutex_Acquire(&glUDP_Channels);
 126         UDP_int_ScanList(gpUDP_Channels, Interface, Address, Length, Buffer);
 127         Mutex_Release(&glUDP_Channels);
 128 }
 129
 130 /**
 131  * \brief Handle an ICMP Unrechable Error
 132  */
 133 void UDP_Unreachable(tInterface *Interface, int Code, void *Address, int Length, void *Buffer)
 134 {
 135
 136 }
 137
 138 /**
 139  * \brief Send a packet
 140  * \param Channel       Channel to send the packet from
 141  * \param Data  Packet data
 142  * \param Length        Length in bytes of packet data
 143  */
 144 void UDP_SendPacketTo(tUDPChannel *Channel, int AddrType, const void *Address, Uint16 Port, const void *Data, size_t Length)
 145 {
 146         tUDPHeader      *hdr;
 147
 148         if(Channel->Interface && Channel->Interface->Type != AddrType)  return ;
 149
 150         switch(AddrType)
 151         {
 152         case 4:
 153                 // Create the packet
 154                 hdr = malloc(sizeof(tUDPHeader)+Length);
 155                 hdr->SourcePort = htons( Channel->LocalPort );
 156                 hdr->DestPort = htons( Port );
 157                 hdr->Length = htons( sizeof(tUDPHeader) + Length );
 158                 hdr->Checksum = 0;      // Checksum can be zero on IPv4
 159                 memcpy(hdr->Data, Data, Length);
 160                 // Pass on the the IPv4 Layer
 161                 // TODO: What if Channel->Interface is NULL here?
 162                 IPv4_SendPacket(Channel->Interface, *(tIPv4*)Address, IP4PROT_UDP, 0, sizeof(tUDPHeader)+Length, hdr);
 163                 // Free allocated packet
 164                 free(hdr);
 165                 break;
 166         }
 167 }
 168
 169 // --- Client Channels
 170 tVFS_Node *UDP_Channel_Init(tInterface *Interface)
 171 {
 172         tUDPChannel     *new;
 173         new = calloc( sizeof(tUDPChannel), 1 );
 174         new->Interface = Interface;
 175         new->Node.ImplPtr = new;
 176         new->Node.NumACLs = 1;
 177         new->Node.ACLs = &gVFS_ACL_EveryoneRW;
 178         new->Node.Type = &gUDP_NodeType;
 179
 180         Mutex_Acquire(&glUDP_Channels);
 181         new->Next = gpUDP_Channels;
 182         gpUDP_Channels = new;
 183         Mutex_Release(&glUDP_Channels);
 184
 185         return &new->Node;
 186 }
 187
 188 /**
 189  * \brief Read from the channel file (wait for a packet)
 190  */
 191 Uint64 UDP_Channel_Read(tVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer)
 192 {
 193         tUDPChannel     *chan = Node->ImplPtr;
 194         tUDPPacket      *pack;
 195         tUDPEndpoint    *ep;
 196          int    ofs;
 197
 198         if(chan->LocalPort == 0) {
 199                 Log_Notice("UDP", "Channel %p sent with no local port", chan);
 200                 return 0;
 201         }
 202
 203         while(chan->Queue == NULL)      Threads_Yield();
 204
 205         for(;;)
 206         {
 207                 VFS_SelectNode(Node, VFS_SELECT_READ, NULL, "UDP_Channel_Read");
 208                 SHORTLOCK(&chan->lQueue);
 209                 if(chan->Queue == NULL) {
 210                         SHORTREL(&chan->lQueue);
 211                         continue;
 212                 }
 213                 pack = chan->Queue;
 214                 chan->Queue = pack->Next;
 215                 if(!chan->Queue) {
 216                         chan->QueueEnd = NULL;
 217                         VFS_MarkAvaliable(Node, 0);     // Nothing left
 218                 }
 219                 SHORTREL(&chan->lQueue);
 220                 break;
 221         }
 222
 223         // Check that the header fits
 224         ep = Buffer;
 225         ofs = 4 + IPStack_GetAddressSize(pack->Remote.AddrType);
 226         if(Length < ofs) {
 227                 free(pack);
 228                 Log_Notice("UDP", "Insuficient space for header in buffer (%i < %i)", (int)Length, ofs);
 229                 return 0;
 230         }
 231
 232         // Fill header
 233         ep->Port = pack->Remote.Port;
 234         ep->AddrType = pack->Remote.AddrType;
 235         memcpy(&ep->Addr, &pack->Remote.Addr, IPStack_GetAddressSize(pack->Remote.AddrType));
 236
 237         // Copy packet data
 238         if(Length > ofs + pack->Length) Length = ofs + pack->Length;
 239         memcpy((char*)Buffer + ofs, pack->Data, Length - ofs);
 240
 241         // Free cached packet
 242         free(pack);
 243
 244         return Length;
 245 }
 246
 247 /**
 248  * \brief Write to the channel file (send a packet)
 249  */
 250 Uint64 UDP_Channel_Write(tVFS_Node *Node, Uint64 Offset, Uint64 Length, const void *Buffer)
 251 {
 252         tUDPChannel     *chan = Node->ImplPtr;
 253         const tUDPEndpoint      *ep;
 254         const void      *data;
 255          int    ofs;
 256         if(chan->LocalPort == 0)        return 0;
 257
 258         ep = Buffer;
 259         ofs = 2 + 2 + IPStack_GetAddressSize( ep->AddrType );
 260
 261         data = (const char *)Buffer + ofs;
 262
 263         UDP_SendPacketTo(chan, ep->AddrType, &ep->Addr, ep->Port, data, (size_t)Length - ofs);
 264
 265         return 0;
 266 }
 267
 268 /**
 269  * \brief Names for channel IOCtl Calls
 270  */
 271 static const char *casIOCtls_Channel[] = {
 272         DRV_IOCTLNAMES,
 273         "getset_localport",
 274         "getset_remoteport",
 275         "getset_remotemask",
 276         "set_remoteaddr",
 277         NULL
 278         };
 279 /**
 280  * \brief Channel IOCtls
 281  */
 282 int UDP_Channel_IOCtl(tVFS_Node *Node, int ID, void *Data)
 283 {
 284         tUDPChannel     *chan = Node->ImplPtr;
 285         ENTER("pNode iID pData", Node, ID, Data);
 286         switch(ID)
 287         {
 288         BASE_IOCTLS(DRV_TYPE_MISC, "UDP Channel", 0x100, casIOCtls_Channel);
 289
 290         case 4: // getset_localport (returns bool success)
 291                 if(!Data)       LEAVE_RET('i', chan->LocalPort);
 292                 if(!CheckMem( Data, sizeof(Uint16) ) ) {
 293                         LOG("Invalid pointer %p", Data);
 294                         LEAVE_RET('i', -1);
 295                 }
 296                 // Set port
 297                 chan->LocalPort = *(Uint16*)Data;
 298                 // Permissions check (Ports lower than 1024 are root-only)
 299                 if(chan->LocalPort != 0 && chan->LocalPort < 1024) {
 300                         if( Threads_GetUID() != 0 ) {
 301                                 LOG("Attempt by non-superuser to listen on port %i", chan->LocalPort);
 302                                 chan->LocalPort = 0;
 303                                 LEAVE_RET('i', -1);
 304                         }
 305                 }
 306                 // Allocate a random port if requested
 307                 if( chan->LocalPort == 0 )
 308                         chan->LocalPort = UDP_int_AllocatePort();
 309                 else
 310                 {
 311                         // Else, mark the requested port as used
 312                         if( UDP_int_MarkPortAsUsed(chan->LocalPort) == 0 ) {
 313                                 LOG("Port %i us currently in use", chan->LocalPort);
 314                                 chan->LocalPort = 0;
 315                                 LEAVE_RET('i', 0);
 316                         }
 317                         LEAVE_RET('i', 1);
 318                 }
 319                 LEAVE_RET('i', 1);
 320
 321         case 5: // getset_remoteport (returns bool success)
 322                 if(!Data)       LEAVE_RET('i', chan->Remote.Port);
 323                 if(!CheckMem( Data, sizeof(Uint16) ) ) {
 324                         LOG("Invalid pointer %p", Data);
 325                         LEAVE_RET('i', -1);
 326                 }
 327                 chan->Remote.Port = *(Uint16*)Data;
 328                 return 1;
 329
 330         case 6: // getset_remotemask (returns bool success)
 331                 if(!Data)       LEAVE_RET('i', chan->RemoteMask);
 332                 if(!CheckMem(Data, sizeof(int)))        LEAVE_RET('i', -1);
 333                 if( !chan->Interface ) {
 334                         LOG("Can't set remote mask on NULL interface");
 335                         LEAVE_RET('i', -1);
 336                 }
 337                 if( *(int*)Data > IPStack_GetAddressSize(chan->Interface->Type) )
 338                         LEAVE_RET('i', -1);
 339                 chan->RemoteMask = *(int*)Data;
 340                 return 1;
 341
 342         case 7: // set_remoteaddr (returns bool success)
 343                 if( !chan->Interface ) {
 344                         LOG("Can't set remote address on NULL interface");
 345                         LEAVE_RET('i', -1);
 346                 }
 347                 if(!CheckMem(Data, IPStack_GetAddressSize(chan->Interface->Type))) {
 348                         LOG("Invalid pointer");
 349                         LEAVE_RET('i', -1);
 350                 }
 351                 memcpy(&chan->Remote.Addr, Data, IPStack_GetAddressSize(chan->Interface->Type));
 352                 return 0;
 353         }
 354         LEAVE_RET('i', 0);
 355 }
 356
 357 /**
 358  * \brief Close and destroy an open channel
 359  */
 360 void UDP_Channel_Close(tVFS_Node *Node)
 361 {
 362         tUDPChannel     *chan = Node->ImplPtr;
 363         tUDPChannel     *prev;
 364
 365         // Remove from the main list first
 366         Mutex_Acquire(&glUDP_Channels);
 367         if(gpUDP_Channels == chan)
 368                 gpUDP_Channels = gpUDP_Channels->Next;
 369         else
 370         {
 371                 for(prev = gpUDP_Channels;
 372                         prev->Next && prev->Next != chan;
 373                         prev = prev->Next);
 374                 if(!prev->Next)
 375                         Log_Warning("UDP", "Bookeeping Fail, channel %p is not in main list", chan);
 376                 else
 377                         prev->Next = prev->Next->Next;
 378         }
 379         Mutex_Release(&glUDP_Channels);
 380
 381         // Clear Queue
 382         SHORTLOCK(&chan->lQueue);
 383         while(chan->Queue)
 384         {
 385                 tUDPPacket      *tmp;
 386                 tmp = chan->Queue;
 387                 chan->Queue = tmp->Next;
 388                 free(tmp);
 389         }
 390         SHORTREL(&chan->lQueue);
 391
 392         // Free channel structure
 393         free(chan);
 394 }
 395
 396 /**
 397  * \return Port Number on success, or zero on failure
 398  */
 399 Uint16 UDP_int_AllocatePort()
 400 {
 401          int    i;
 402         Mutex_Acquire(&glUDP_Ports);
 403         // Fast Search
 404         for( i = UDP_ALLOC_BASE; i < 0x10000; i += 32 )
 405                 if( gUDP_Ports[i/32] != 0xFFFFFFFF )
 406                         break;
 407         if(i == 0x10000)        return 0;
 408         for( ;; i++ )
 409         {
 410                 if( !(gUDP_Ports[i/32] & (1 << (i%32))) )
 411                         return i;
 412         }
 413         Mutex_Release(&glUDP_Ports);
 414 }
 415
 416 /**
 417  * \brief Allocate a specific port
 418  * \return Boolean Success
 419  */
 420 int UDP_int_MarkPortAsUsed(Uint16 Port)
 421 {
 422         Mutex_Acquire(&glUDP_Ports);
 423         if( gUDP_Ports[Port/32] & (1 << (Port%32)) ) {
 424                 return 0;
 425                 Mutex_Release(&glUDP_Ports);
 426         }
 427         gUDP_Ports[Port/32] |= 1 << (Port%32);
 428         Mutex_Release(&glUDP_Ports);
 429         return 1;
 430 }
 431
 432 /**
 433  * \brief Free an allocated port
 434  */
 435 void UDP_int_FreePort(Uint16 Port)
 436 {
 437         Mutex_Acquire(&glUDP_Ports);
 438         gUDP_Ports[Port/32] &= ~(1 << (Port%32));
 439         Mutex_Release(&glUDP_Ports);
 440 }