KernelLand/Kernel/drv/dgram_pipe.c

   1 /*
   2  * Acess2 Kernel
   3  * - By John Hodge (thePowersGang);
   4  *
   5  * drv/dgram_pipe.c
   6  * - Connection+Datagram based local IPC
   7  */
   8 #define DEBUG   1
   9 #include <vfs.h>
  10 #include <fs_devfs.h>
  11 #include <modules.h>
  12 #include <rwlock.h>
  13 #include <semaphore.h>
  14
  15 #define DEF_MAX_BLOCK_SIZE      0x1000
  16 #define DEF_MAX_BYTE_LIMIT      0x8000
  17
  18 // === TYPES ===
  19 typedef struct sIPCPipe_Packet  tIPCPipe_Packet;
  20 typedef struct sIPCPipe_Endpoint        tIPCPipe_Endpoint;
  21 typedef struct sIPCPipe_Channel tIPCPipe_Channel;
  22 typedef struct sIPCPipe_Server  tIPCPipe_Server;
  23
  24 // === STRUCTURES ===
  25 struct sIPCPipe_Packet
  26 {
  27         tIPCPipe_Packet *Next;
  28         size_t  Length;
  29         size_t  Offset; //!< Offset to first unread byte (for streams)
  30         void    *Data;
  31 };
  32 struct sIPCPipe_Endpoint
  33 {
  34         tMutex  lList;
  35         tIPCPipe_Packet *OutHead;
  36         tIPCPipe_Packet *OutTail;
  37         tVFS_Node       Node;
  38 };
  39 struct sIPCPipe_Channel
  40 {
  41         tIPCPipe_Channel        *Next;
  42         tIPCPipe_Channel        *Prev;
  43         tIPCPipe_Server *Server;
  44         tIPCPipe_Endpoint       ServerEP;
  45         tIPCPipe_Endpoint       ClientEP;
  46 };
  47 struct sIPCPipe_Server
  48 {
  49         tIPCPipe_Server *Next;
  50         tIPCPipe_Server *Prev;
  51         char    *Name;
  52         size_t  MaxBlockSize;   // Max size of a 'packet'
  53         size_t  QueueByteLimit; // Maximum number of bytes held in kernel for this server
  54         size_t  CurrentByteCount;
  55         tVFS_Node       ServerNode;
  56         tRWLock lChannelList;
  57         tIPCPipe_Channel        *FirstClient;
  58         tIPCPipe_Channel        *LastClient;
  59         tIPCPipe_Channel        *FirstUnseenClient;     // !< First client server hasn't opened
  60 };
  61
  62 // === PROTOTYPES ===
  63  int    IPCPipe_Install(char **Arguments);
  64 // - Root
  65 tVFS_Node       *IPCPipe_Root_MkNod(tVFS_Node *Node, const char *Name, Uint Flags);
  66  int    IPCPipe_Root_ReadDir(tVFS_Node *Node, int ID, char Name[FILENAME_MAX]);
  67 tVFS_Node       *IPCPipe_Root_FindDir(tVFS_Node *Node, const char *Name);
  68 // - Server
  69  int    IPCPipe_Server_ReadDir(tVFS_Node *Node, int ID, char Name[FILENAME_MAX]);
  70 tVFS_Node       *IPCPipe_Server_FindDir(tVFS_Node *Node, const char *Name);
  71 void    IPCPipe_Server_Close(tVFS_Node *Node);
  72 // - Socket
  73 tIPCPipe_Channel        *IPCPipe_int_GetEPs(tVFS_Node *Node, tIPCPipe_Endpoint **lep, tIPCPipe_Endpoint **rep);
  74 size_t  IPCPipe_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Dest);
  75 size_t  IPCPipe_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Src);
  76 void    IPCPipe_Client_Close(tVFS_Node *Node);
  77
  78 // === GLOBALS ===
  79 // - Server node: Directory
  80 tVFS_NodeType   gIPCPipe_ServerNodeType = {
  81         .TypeName = "IPC Pipe - Server",
  82         .ReadDir = IPCPipe_Server_ReadDir,
  83         .FindDir = IPCPipe_Server_FindDir,
  84         .Close = IPCPipe_Server_Close
  85 };
  86 tVFS_NodeType   gIPCPipe_ChannelNodeType = {
  87         .TypeName = "IPC Pipe - Channel",
  88         .Read = IPCPipe_Client_Read,
  89         .Write = IPCPipe_Client_Write,
  90         .Close = IPCPipe_Client_Close
  91 };
  92 tVFS_NodeType   gIPCPipe_RootNodeType = {
  93         .TypeName = "IPC Pipe - Root",
  94         .MkNod = IPCPipe_Root_MkNod,
  95         .ReadDir = IPCPipe_Root_ReadDir,
  96         .FindDir = IPCPipe_Root_FindDir
  97 };
  98 tDevFS_Driver   gIPCPipe_DevFSInfo = {
  99         .Name = "ipcpipe",
 100         .RootNode = {.Type=&gIPCPipe_RootNodeType,.Flags=VFS_FFLAG_DIRECTORY,.Size=-1}
 101 };
 102 // - Global list of servers
 103 tRWLock glIPCPipe_ServerList;
 104 tIPCPipe_Server *gpIPCPipe_FirstServer;
 105 tIPCPipe_Server *gpIPCPipe_LastServer;
 106 // - Module definition
 107 MODULE_DEFINE(0, 0x0100, IPCPipe, IPCPipe_Install, NULL, NULL);
 108
 109 // === CODE ===
 110 int IPCPipe_Install(char **Arguments)
 111 {
 112         DevFS_AddDevice(&gIPCPipe_DevFSInfo);
 113         return MODULE_ERR_OK;
 114 }
 115
 116 // - Root -
 117 /*
 118  * \brief Create a new named pipe
 119  * \note Expected to be called from VFS_Open with OPENFLAG_CREATE
 120  */
 121 tVFS_Node *IPCPipe_Root_MkNod(tVFS_Node *Node, const char *Name, Uint Flags)
 122 {
 123         tIPCPipe_Server *srv;
 124
 125         ENTER("pNode sName xFlags", Node, Name, Flags);
 126
 127         // Write Lock
 128         RWLock_AcquireWrite(&glIPCPipe_ServerList);
 129         for( srv = gpIPCPipe_FirstServer; srv; srv = srv->Next )
 130         {
 131                 if( strcmp(srv->Name, Name) == 0 )
 132                         break;
 133         }
 134         if( srv )
 135         {
 136                 RWLock_Release(&glIPCPipe_ServerList);
 137                 LEAVE('n');
 138                 return NULL;
 139         }
 140
 141
 142         srv = calloc( 1, sizeof(tIPCPipe_Server) + strlen(Name) + 1 );
 143         srv->Name = (void*)(srv + 1);
 144         strcpy(srv->Name, Name);
 145         srv->MaxBlockSize = DEF_MAX_BLOCK_SIZE;
 146         srv->QueueByteLimit = DEF_MAX_BYTE_LIMIT;
 147         srv->ServerNode.Type = &gIPCPipe_ServerNodeType;
 148         srv->ServerNode.ImplPtr = srv;
 149         srv->ServerNode.Flags = VFS_FFLAG_DIRECTORY;
 150
 151         // Lock already held
 152         if( gpIPCPipe_LastServer )
 153                 gpIPCPipe_LastServer->Next = srv;
 154         else
 155                 gpIPCPipe_FirstServer = srv;
 156         srv->Prev = gpIPCPipe_LastServer;
 157         gpIPCPipe_LastServer = srv;
 158         RWLock_Release(&glIPCPipe_ServerList);
 159
 160         LEAVE('p', &srv->ServerNode);
 161         return &srv->ServerNode;
 162 }
 163
 164 int IPCPipe_Root_ReadDir(tVFS_Node *Node, int ID, char Name[FILENAME_MAX])
 165 {
 166         tIPCPipe_Server *srv;
 167         RWLock_AcquireRead(&glIPCPipe_ServerList);
 168         for( srv = gpIPCPipe_FirstServer; srv && ID--; srv = srv->Next )
 169                 ;
 170         RWLock_Release(&glIPCPipe_ServerList);
 171
 172         if( srv ) {
 173                 strncpy(Name, srv->Name, sizeof(Name));
 174                 return 0;
 175         }
 176
 177         return -1;
 178 }
 179 /**
 180  * \return New client pointer
 181  */
 182 tVFS_Node *IPCPipe_Root_FindDir(tVFS_Node *Node, const char *Name)
 183 {
 184         tIPCPipe_Server *srv;
 185         ENTER("pNode sName", Node, Name);
 186
 187         // Find server
 188         RWLock_AcquireRead(&glIPCPipe_ServerList);
 189         for( srv = gpIPCPipe_FirstServer; srv; srv = srv->Next )
 190         {
 191                 LOG("== %s", srv->Name);
 192                 if( strcmp(srv->Name, Name) == 0 )
 193                         break;
 194         }
 195         RWLock_Release(&glIPCPipe_ServerList);
 196         if( !srv ) {
 197                 LEAVE('n');
 198                 return NULL;
 199         }
 200
 201         // Create new client
 202         tIPCPipe_Channel *new_client;
 203
 204         new_client = calloc(1, sizeof(tIPCPipe_Channel));
 205         new_client->Server = srv;
 206         new_client->ClientEP.Node.Type = &gIPCPipe_ChannelNodeType;
 207         new_client->ClientEP.Node.ImplPtr = new_client;
 208         new_client->ServerEP.Node.Type = &gIPCPipe_ChannelNodeType;
 209         new_client->ServerEP.Node.ImplPtr = new_client;
 210
 211         // Append to server list
 212         RWLock_AcquireWrite(&srv->lChannelList);
 213         if(srv->LastClient)
 214                 srv->LastClient->Next = new_client;
 215         else
 216                 srv->FirstClient = new_client;
 217         srv->LastClient = new_client;
 218         if(!srv->FirstUnseenClient)
 219                 srv->FirstUnseenClient = new_client;
 220         VFS_MarkAvaliable(&srv->ServerNode, !!srv->FirstUnseenClient);
 221         RWLock_Release(&srv->lChannelList);
 222
 223         LEAVE('p', &new_client->ClientEP.Node);
 224         return &new_client->ClientEP.Node;
 225 }
 226
 227 // --- Server ---
 228 int IPCPipe_Server_ReadDir(tVFS_Node *Node, int ID, char Name[FILENAME_MAX])
 229 {
 230         // 'next' is a valid entry, but readdir should never be called on this node
 231         return -1;
 232 }
 233 tVFS_Node *IPCPipe_Server_FindDir(tVFS_Node *Node, const char *Name)
 234 {
 235         tIPCPipe_Server *srv = Node->ImplPtr;
 236
 237         ENTER("pNode sName", Node, Name);
 238
 239         if( strcmp(Name, "newclient") != 0 ) {
 240                 LEAVE('n');
 241                 return NULL;
 242         }
 243
 244         VFS_SelectNode(Node, VFS_SELECT_READ, 0, "IPCPipe Server");
 245
 246         tIPCPipe_Channel *conn;
 247         RWLock_AcquireRead(&srv->lChannelList);
 248         conn = srv->FirstUnseenClient;
 249         if( conn )
 250         {
 251                 srv->FirstUnseenClient = conn->Next;
 252         }
 253         VFS_MarkAvaliable(Node, !!srv->FirstUnseenClient);
 254         RWLock_Release(&srv->lChannelList);
 255
 256         if( !conn ) {
 257                 LEAVE('n');
 258                 return NULL;
 259         }
 260
 261         // Success
 262         LEAVE('p', &conn->ServerEP.Node);
 263         return &conn->ServerEP.Node;
 264 }
 265
 266 void IPCPipe_Server_Close(tVFS_Node *Node)
 267 {
 268         tIPCPipe_Server *srv = Node->ImplPtr;
 269
 270         // Flag server as being destroyed
 271
 272         // Force-close all children
 273         RWLock_AcquireWrite(&srv->lChannelList);
 274         for(tIPCPipe_Channel *client = srv->FirstClient; client; client = client->Next)
 275         {
 276                 client->Server = NULL;
 277         }
 278         RWLock_Release(&srv->lChannelList);
 279
 280         // Remove from global list
 281         RWLock_AcquireWrite(&glIPCPipe_ServerList);
 282         // - Forward link
 283         if(srv->Prev)
 284                 srv->Prev->Next = srv->Next;
 285         else
 286                 gpIPCPipe_FirstServer = srv->Next;
 287         // - Reverse link
 288         if(srv->Next)
 289                 srv->Next->Prev = srv->Prev;
 290         else
 291                 gpIPCPipe_LastServer = srv->Prev;
 292         RWLock_Release(&glIPCPipe_ServerList);
 293 }
 294
 295 // --- Channel ---
 296 tIPCPipe_Channel *IPCPipe_int_GetEPs(tVFS_Node *Node, tIPCPipe_Endpoint **lep, tIPCPipe_Endpoint **rep)
 297 {
 298         tIPCPipe_Channel        *ch = Node->ImplPtr;
 299         if( ch )
 300         {
 301                 *lep = (Node == &ch->ServerEP.Node ? &ch->ServerEP : &ch->ClientEP);
 302                 *rep = (Node == &ch->ServerEP.Node ? &ch->ClientEP : &ch->ServerEP);
 303         }
 304         return ch;
 305 }
 306 size_t IPCPipe_Client_Read(tVFS_Node *Node, off_t Offset, size_t Length, void *Dest)
 307 {
 308         tIPCPipe_Endpoint       *lep, *rep;
 309         tIPCPipe_Channel        *channel = IPCPipe_int_GetEPs(Node, &lep, &rep);
 310
 311         ENTER("pNode xOffset xLength pDest", Node, Offset, Length, Dest);
 312
 313         // Closed endpoint / channel
 314         if( !channel || channel->Server == NULL ) {
 315                 LEAVE('i', -1);
 316                 return -1;
 317         }
 318
 319         // Wait for a packet to be ready
 320         VFS_SelectNode(Node, VFS_SELECT_READ, 0, "IPCPipe Endpoint");
 321         if( channel->Server == NULL ) {
 322                 LEAVE('i', -1);
 323                 return -1;
 324         }
 325
 326         // Pop a packet from the list
 327         Mutex_Acquire(&rep->lList);
 328         if( !rep->Node.ImplPtr )
 329         {
 330                 Mutex_Release(&rep->lList);
 331                 LEAVE('i', -1);
 332                 return -1;
 333         }
 334         tIPCPipe_Packet *pkt = rep->OutHead;
 335         if(pkt)
 336                 rep->OutHead = pkt->Next;
 337         if(!rep->OutHead)
 338                 rep->OutTail = NULL;
 339         VFS_MarkAvaliable(Node, !!rep->OutHead);
 340         Mutex_Release(&rep->lList);
 341
 342         // Return
 343         size_t ret = 0;
 344         if(pkt)
 345         {
 346                 ret = MIN(pkt->Length, Length);
 347                 memcpy(Dest, pkt->Data, ret);
 348                 free(pkt);
 349         }
 350         else
 351         {
 352                 Log_Warning("IPCPipe", "No packet ready but semaphore returned");
 353         }
 354
 355         LEAVE('i', ret);
 356         return ret;
 357 }
 358
 359 size_t IPCPipe_Client_Write(tVFS_Node *Node, off_t Offset, size_t Length, const void *Src)
 360 {
 361         tIPCPipe_Endpoint       *lep, *rep;
 362         tIPCPipe_Channel        *channel = IPCPipe_int_GetEPs(Node, &lep, &rep);
 363
 364         ENTER("pNode xOffset xLength pSrc", Node, Offset, Length, Src);
 365
 366         // Ensure the server hasn't been closed
 367         if( !channel || channel->Server == NULL ) {
 368                 LEAVE('i', -1);
 369                 return -1;
 370         }
 371
 372         if( Length > channel->Server->MaxBlockSize ) {
 373                 LEAVE('i', 0);
 374                 return 0;
 375         }
 376
 377         // Create packet structure
 378         tIPCPipe_Packet *pkt = malloc(sizeof(tIPCPipe_Packet)+Length);
 379         pkt->Next = NULL;
 380         pkt->Offset = 0;
 381         pkt->Length = Length;
 382         pkt->Data = pkt + 1;
 383         memcpy(pkt->Data, Src, Length);
 384
 385         // Append to list
 386         Mutex_Acquire(&lep->lList);
 387         if( !Node->ImplPtr )
 388         {
 389                 // Client was closed by another thread
 390                 free(pkt);
 391                 Mutex_Release(&lep->lList);
 392                 LEAVE('i', -1);
 393                 return -1;
 394         }
 395         if(lep->OutTail)
 396                 lep->OutTail->Next = pkt;
 397         else
 398                 lep->OutHead = pkt;
 399         lep->OutTail = pkt;
 400         Mutex_Release(&lep->lList);
 401
 402         // Signal other end
 403         VFS_MarkAvaliable(&rep->Node, 1);
 404
 405         LEAVE('i', Length);
 406         return Length;
 407 }
 408
 409 void IPCPipe_Client_Close(tVFS_Node *Node)
 410 {
 411         tIPCPipe_Endpoint       *lep, *rep;
 412         tIPCPipe_Channel        *ch = IPCPipe_int_GetEPs(Node, &lep, &rep);
 413
 414         ENTER("pNode", Node);
 415
 416         if( !ch ) {
 417                 Log_Warning("IPCPipe", "Endpoint %p double-closed", ch);
 418                 return ;
 419         }
 420
 421         // Mark client as closed
 422         Node->ImplPtr = NULL;
 423         // Clear packets
 424         Mutex_Acquire(&lep->lList);
 425         while( lep->OutHead ) {
 426                 tIPCPipe_Packet *next = lep->OutHead->Next;
 427                 free(lep->OutHead);
 428                 lep->OutHead = next;
 429         }
 430         Mutex_Release(&lep->lList);
 431         LOG("Packets cleared");
 432
 433         // Tell remote that local has closed
 434         VFS_MarkError(&rep->Node, 1);
 435         // TODO: Deliver SIGPIPE or similar to all owners of remote
 436         // Clean up if both sides are closed
 437         if( rep->Node.ImplPtr == NULL )
 438         {
 439                 LOG("Remote closed, cleaning up");
 440                 tIPCPipe_Server *srv = ch->Server;
 441                 if( srv )
 442                 {
 443                         RWLock_AcquireWrite(&srv->lChannelList);
 444                         if(ch->Prev)
 445                                 ch->Prev->Next = ch->Next;
 446                         else
 447                                 srv->FirstClient = ch->Next;
 448                         if(ch->Next)
 449                                 ch->Next->Prev = ch->Prev;
 450                         else
 451                                 srv->LastClient = ch->Prev;
 452                         if(srv->FirstUnseenClient == ch)
 453                                 srv->FirstUnseenClient = ch->Next;
 454                         RWLock_Release(&srv->lChannelList);
 455                 }
 456                 free(ch);
 457         }
 458         LEAVE('-');
 459 }