1 /* 2 * Copyright 2003-2007, Waldemar Kornewald <wkornew@gmx.net> 3 * Distributed under the terms of the MIT License. 4 */ 5 6 /*! \class KPPPLayer 7 \brief An abstract layer that can encapsulate/send and receive packets. 8 9 All packet handlers should derive from this class. It does not define a protocol 10 number like KPPPProtocol does. It only has a header overhead and an encapsulation 11 level that is used to determine the order at which the packets get encapsulated 12 by the layers. If this layer does not encapsulate PPP packets you should use 13 PPP_PROTOCOL_LEVEL. 14 */ 15 16 #ifdef _KERNEL_MODE 17 #include <kernel_cpp.h> 18 #endif 19 20 #include <KPPPLayer.h> 21 22 #include <net_buffer.h> 23 24 #include <cstdlib> 25 #include <cstring> 26 27 extern net_buffer_module_info *gBufferModule; 28 29 /*! \brief Creates a new layer. 30 31 If an error occurs in the constructor you should set \c fInitStatus. 32 */ 33 KPPPLayer::KPPPLayer(const char *name, ppp_level level, uint32 overhead) 34 : fInitStatus(B_OK), 35 fOverhead(overhead), 36 fName(NULL), 37 fLevel(level), 38 fNext(NULL) 39 { 40 SetName(name); 41 } 42 43 44 //! Only frees the name. 45 KPPPLayer::~KPPPLayer() 46 { 47 free(fName); 48 } 49 50 51 //! Returns \c fInitStatus. May be overridden to return status-dependend errors. 52 status_t 53 KPPPLayer::InitCheck() const 54 { 55 return fInitStatus; 56 } 57 58 59 //! Sends a packet to the next layer in the chain. 60 status_t 61 KPPPLayer::SendToNext(net_buffer *packet, uint16 protocolNumber) const 62 { 63 if (!packet) 64 return B_ERROR; 65 66 // Find the next possible handler for this packet. 67 // Normal protocols (Level() >= PPP_PROTOCOL_LEVEL) do not encapsulate anything. 68 if (Next()) { 69 if (Next()->IsAllowedToSend() && Next()->Level() < PPP_PROTOCOL_LEVEL) 70 return Next()->Send(packet, protocolNumber); 71 else 72 return Next()->SendToNext(packet, protocolNumber); 73 } else { 74 ERROR("KPPPLayer: SendToNext() failed because there is no next handler!\n"); 75 gBufferModule->free(packet); 76 return B_ERROR; 77 } 78 } 79 80 81 /*! \brief You may override this for periodic tasks. 82 83 This method gets called every \c PPP_PULSE_RATE microseconds. 84 */ 85 void 86 KPPPLayer::Pulse() 87 { 88 // do nothing by default 89 } 90 91 92 //! Allows changing the name of this layer. 93 void 94 KPPPLayer::SetName(const char *name) 95 { 96 free(fName); 97 98 if (name) 99 fName = strdup(name); 100 else 101 fName = NULL; 102 } 103