KernelLand/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 size_t  UDP_Channel_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer);
  19 size_t  UDP_Channel_Write(tVFS_Node *Node, off_t Offset, size_t 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->Remote.AddrType = Interface->Type;
  95                 pack->Length = len;
  96                 memcpy(pack->Data, hdr->Data, len);
  97
  98                 // Add the packet to the channel's queue
  99                 SHORTLOCK(&chan->lQueue);
 100                 if(chan->Queue)
 101                         chan->QueueEnd->Next = pack;
 102                 else
 103                         chan->QueueEnd = chan->Queue = pack;
 104                 SHORTREL(&chan->lQueue);
 105                 VFS_MarkAvaliable(&chan->Node, 1);
 106                 Mutex_Release(&glUDP_Channels);
 107                 return 1;
 108         }
 109         return 0;
 110 }
 111
 112 /**
 113  * \fn void UDP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 114  * \brief Handles a packet from the IP Layer
 115  */
 116 void UDP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
 117 {
 118         tUDPHeader      *hdr = Buffer;
 119
 120         Log_Debug("UDP", "%i bytes :%i->:%i (Cksum 0x%04x)",
 121                 ntohs(hdr->Length), ntohs(hdr->SourcePort), ntohs(hdr->Length), ntohs(hdr->Checksum));
 122
 123         // Check registered connections
 124         Mutex_Acquire(&glUDP_Channels);
 125         UDP_int_ScanList(gpUDP_Channels, Interface, Address, Length, Buffer);
 126         Mutex_Release(&glUDP_Channels);
 127 }
 128
 129 /**
 130  * \brief Handle an ICMP Unrechable Error
 131  */
 132 void UDP_Unreachable(tInterface *Interface, int Code, void *Address, int Length, void *Buffer)
 133 {
 134
 135 }
 136
 137 /**
 138  * \brief Send a packet
 139  * \param Channel       Channel to send the packet from
 140  * \param Data  Packet data
 141  * \param Length        Length in bytes of packet data
 142  */
 143 void UDP_SendPacketTo(tUDPChannel *Channel, int AddrType, const void *Address, Uint16 Port, const void *Data, size_t Length)
 144 {
 145         tUDPHeader      hdr;
 146
 147         if(Channel->Interface && Channel->Interface->Type != AddrType)  return ;
 148
 149         switch(AddrType)
 150         {
 151         case 4:
 152                 // Create the packet
 153                 hdr.SourcePort = htons( Channel->LocalPort );
 154                 hdr.DestPort = htons( Port );
 155                 hdr.Length = htons( sizeof(tUDPHeader) + Length );
 156                 hdr.Checksum = 0;       // Checksum can be zero on IPv4
 157                 // Pass on the the IPv4 Layer
 158                 tIPStackBuffer  *buffer = IPStack_Buffer_CreateBuffer(2 + IPV4_BUFFERS);
 159                 IPStack_Buffer_AppendSubBuffer(buffer, Length, 0, Data, NULL, NULL);
 160                 IPStack_Buffer_AppendSubBuffer(buffer, sizeof(hdr), 0, &hdr, NULL, NULL);
 161                 // TODO: What if Channel->Interface is NULL here?
 162                 IPv4_SendPacket(Channel->Interface, *(tIPv4*)Address, IP4PROT_UDP, 0, buffer);
 163                 IPStack_Buffer_DestroyBuffer(buffer);
 164                 break;
 165         }
 166 }
 167
 168 // --- Client Channels
 169 tVFS_Node *UDP_Channel_Init(tInterface *Interface)
 170 {
 171         tUDPChannel     *new;
 172         new = calloc( sizeof(tUDPChannel), 1 );
 173         new->Interface = Interface;
 174         new->Node.ImplPtr = new;
 175         new->Node.NumACLs = 1;
 176         new->Node.ACLs = &gVFS_ACL_EveryoneRW;
 177         new->Node.Type = &gUDP_NodeType;
 178
 179         Mutex_Acquire(&glUDP_Channels);
 180         new->Next = gpUDP_Channels;
 181         gpUDP_Channels = new;
 182         Mutex_Release(&glUDP_Channels);
 183
 184         return &new->Node;
 185 }
 186
 187 /**
 188  * \brief Read from the channel file (wait for a packet)
 189  */
 190 size_t UDP_Channel_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Buffer)
 191 {
 192         tUDPChannel     *chan = Node->ImplPtr;
 193         tUDPPacket      *pack;
 194         tUDPEndpoint    *ep;
 195          int    ofs, addrlen;
 196
 197         if(chan->LocalPort == 0) {
 198                 Log_Notice("UDP", "Channel %p sent with no local port", chan);
 199                 return 0;
 200         }
 201
 202         while(chan->Queue == NULL)      Threads_Yield();
 203
 204         for(;;)
 205         {
 206                 VFS_SelectNode(Node, VFS_SELECT_READ, NULL, "UDP_Channel_Read");
 207                 SHORTLOCK(&chan->lQueue);
 208                 if(chan->Queue == NULL) {
 209                         SHORTREL(&chan->lQueue);
 210                         continue;
 211                 }
 212                 pack = chan->Queue;
 213                 chan->Queue = pack->Next;
 214                 if(!chan->Queue) {
 215                         chan->QueueEnd = NULL;
 216                         VFS_MarkAvaliable(Node, 0);     // Nothing left
 217                 }
 218                 SHORTREL(&chan->lQueue);
 219                 break;
 220         }
 221
 222         // Check that the header fits
 223         addrlen = IPStack_GetAddressSize(pack->Remote.AddrType);
 224         ep = Buffer;
 225         ofs = 4 + addrlen;
 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, addrlen);
 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 size_t UDP_Channel_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Buffer)
 251 {
 252         tUDPChannel     *chan = Node->ImplPtr;
 253         const tUDPEndpoint      *ep;
 254         const void      *data;
 255          int    ofs;
 256
 257         if(chan->LocalPort == 0) {
 258                 Log_Notice("UDP", "Write to channel %p with zero local port", chan);
 259                 return 0;
 260         }
 261
 262         ep = Buffer;
 263         ofs = 2 + 2 + IPStack_GetAddressSize( ep->AddrType );
 264
 265         data = (const char *)Buffer + ofs;
 266
 267         UDP_SendPacketTo(chan, ep->AddrType, &ep->Addr, ep->Port, data, (size_t)Length - ofs);
 268
 269         return Length;
 270 }
 271
 272 /**
 273  * \brief Names for channel IOCtl Calls
 274  */
 275 static const char *casIOCtls_Channel[] = {
 276         DRV_IOCTLNAMES,
 277         "getset_localport",
 278         "getset_remoteport",
 279         "getset_remotemask",
 280         "set_remoteaddr",
 281         NULL
 282         };
 283 /**
 284  * \brief Channel IOCtls
 285  */
 286 int UDP_Channel_IOCtl(tVFS_Node *Node, int ID, void *Data)
 287 {
 288         tUDPChannel     *chan = Node->ImplPtr;
 289         ENTER("pNode iID pData", Node, ID, Data);
 290         switch(ID)
 291         {
 292         BASE_IOCTLS(DRV_TYPE_MISC, "UDP Channel", 0x100, casIOCtls_Channel);
 293
 294         case 4: // getset_localport (returns bool success)
 295                 if(!Data)       LEAVE_RET('i', chan->LocalPort);
 296                 if(!CheckMem( Data, sizeof(Uint16) ) ) {
 297                         LOG("Invalid pointer %p", Data);
 298                         LEAVE_RET('i', -1);
 299                 }
 300                 // Set port
 301                 chan->LocalPort = *(Uint16*)Data;
 302                 // Permissions check (Ports lower than 1024 are root-only)
 303                 if(chan->LocalPort != 0 && chan->LocalPort < 1024) {
 304                         if( Threads_GetUID() != 0 ) {
 305                                 LOG("Attempt by non-superuser to listen on port %i", chan->LocalPort);
 306                                 chan->LocalPort = 0;
 307                                 LEAVE_RET('i', -1);
 308                         }
 309                 }
 310                 // Allocate a random port if requested
 311                 if( chan->LocalPort == 0 )
 312                         chan->LocalPort = UDP_int_AllocatePort();
 313                 else
 314                 {
 315                         // Else, mark the requested port as used
 316                         if( UDP_int_MarkPortAsUsed(chan->LocalPort) == 0 ) {
 317                                 LOG("Port %i us currently in use", chan->LocalPort);
 318                                 chan->LocalPort = 0;
 319                                 LEAVE_RET('i', 0);
 320                         }
 321                         LEAVE_RET('i', 1);
 322                 }
 323                 LEAVE_RET('i', 1);
 324
 325         case 5: // getset_remoteport (returns bool success)
 326                 if(!Data)       LEAVE_RET('i', chan->Remote.Port);
 327                 if(!CheckMem( Data, sizeof(Uint16) ) ) {
 328                         LOG("Invalid pointer %p", Data);
 329                         LEAVE_RET('i', -1);
 330                 }
 331                 chan->Remote.Port = *(Uint16*)Data;
 332                 return 1;
 333
 334         case 6: // getset_remotemask (returns bool success)
 335                 if(!Data)       LEAVE_RET('i', chan->RemoteMask);
 336                 if(!CheckMem(Data, sizeof(int)))        LEAVE_RET('i', -1);
 337                 if( !chan->Interface ) {
 338                         LOG("Can't set remote mask on NULL interface");
 339                         LEAVE_RET('i', -1);
 340                 }
 341                 if( *(int*)Data > IPStack_GetAddressSize(chan->Interface->Type) )
 342                         LEAVE_RET('i', -1);
 343                 chan->RemoteMask = *(int*)Data;
 344                 return 1;
 345
 346         case 7: // set_remoteaddr (returns bool success)
 347                 if( !chan->Interface ) {
 348                         LOG("Can't set remote address on NULL interface");
 349                         LEAVE_RET('i', -1);
 350                 }
 351                 if(!CheckMem(Data, IPStack_GetAddressSize(chan->Interface->Type))) {
 352                         LOG("Invalid pointer");
 353                         LEAVE_RET('i', -1);
 354                 }
 355                 memcpy(&chan->Remote.Addr, Data, IPStack_GetAddressSize(chan->Interface->Type));
 356                 return 0;
 357         }
 358         LEAVE_RET('i', 0);
 359 }
 360
 361 /**
 362  * \brief Close and destroy an open channel
 363  */
 364 void UDP_Channel_Close(tVFS_Node *Node)
 365 {
 366         tUDPChannel     *chan = Node->ImplPtr;
 367         tUDPChannel     *prev;
 368
 369         // Remove from the main list first
 370         Mutex_Acquire(&glUDP_Channels);
 371         if(gpUDP_Channels == chan)
 372                 gpUDP_Channels = gpUDP_Channels->Next;
 373         else
 374         {
 375                 for(prev = gpUDP_Channels;
 376                         prev->Next && prev->Next != chan;
 377                         prev = prev->Next);
 378                 if(!prev->Next)
 379                         Log_Warning("UDP", "Bookeeping Fail, channel %p is not in main list", chan);
 380                 else
 381                         prev->Next = prev->Next->Next;
 382         }
 383         Mutex_Release(&glUDP_Channels);
 384
 385         // Clear Queue
 386         SHORTLOCK(&chan->lQueue);
 387         while(chan->Queue)
 388         {
 389                 tUDPPacket      *tmp;
 390                 tmp = chan->Queue;
 391                 chan->Queue = tmp->Next;
 392                 free(tmp);
 393         }
 394         SHORTREL(&chan->lQueue);
 395
 396         // Free channel structure
 397         free(chan);
 398 }
 399
 400 /**
 401  * \return Port Number on success, or zero on failure
 402  */
 403 Uint16 UDP_int_AllocatePort()
 404 {
 405          int    i;
 406         Mutex_Acquire(&glUDP_Ports);
 407         // Fast Search
 408         for( i = UDP_ALLOC_BASE; i < 0x10000; i += 32 )
 409                 if( gUDP_Ports[i/32] != 0xFFFFFFFF )
 410                         break;
 411         if(i == 0x10000)        return 0;
 412         for( ;; i++ )
 413         {
 414                 if( !(gUDP_Ports[i/32] & (1 << (i%32))) )
 415                         return i;
 416         }
 417         Mutex_Release(&glUDP_Ports);
 418 }
 419
 420 /**
 421  * \brief Allocate a specific port
 422  * \return Boolean Success
 423  */
 424 int UDP_int_MarkPortAsUsed(Uint16 Port)
 425 {
 426         Mutex_Acquire(&glUDP_Ports);
 427         if( gUDP_Ports[Port/32] & (1 << (Port%32)) ) {
 428                 return 0;
 429                 Mutex_Release(&glUDP_Ports);
 430         }
 431         gUDP_Ports[Port/32] |= 1 << (Port%32);
 432         Mutex_Release(&glUDP_Ports);
 433         return 1;
 434 }
 435
 436 /**
 437  * \brief Free an allocated port
 438  */
 439 void UDP_int_FreePort(Uint16 Port)
 440 {
 441         Mutex_Acquire(&glUDP_Ports);
 442         gUDP_Ports[Port/32] &= ~(1 << (Port%32));
 443         Mutex_Release(&glUDP_Ports);
 444 }