Refactored multicast source address validation.

HISTORY

@@ -142,11 +142,11 @@ VDR Plugin 'iptv' Revision History
 
 - Updated for vdr-1.7.15.
 
-2010-09-12: Version 0.4.3
+2010-09-15: Version 0.4.3
 
 - Renamed Sid scanner to section id scanner and added
   experimental Tid/Nid support into it.
-- Added validation for source addresses of socket data.
+- Added optional source address validation for UDP protocol.
 - Fixed audio pid detection in pid scanner.
 - Changed ProvidesChannel() to set the need of detaching
   receivers due to VDR's channel selection mechanism.

README

@@ -161,6 +161,9 @@ Notes:
 - EIT scanning functionality can be disabled for all IPTV channels by applying
   the "disable_eitscan" patch to the VDR.
 
+- Source address validation can be enabled for UDP protocol separated by 
+  adding the source address after a ';' character: "U=239.192.0.1;239.192.0.2"
+
 Acknowledgements:
 
 - The IPTV section filtering code is derived from Linux kernel.

protocolext.c

@@ -109,7 +109,7 @@ bool cIptvProtocolExt::Open(void)
   if (!strlen(*scriptFile))
      return false;
   // Create the listening socket
-  OpenSocket(INADDR_LOOPBACK, socketPort);
+  OpenSocket(socketPort);
   // Execute the external script
   ExecuteScript();
   isActive = true;

protocolhttp.c

@@ -19,10 +19,10 @@
 #include "protocolhttp.h"
 
 cIptvProtocolHttp::cIptvProtocolHttp()
+: streamAddr(NULL),
+  streamPath(strdup("/"))
 {
   debug("cIptvProtocolHttp::cIptvProtocolHttp()\n");
-  streamAddr = strdup("");
-  streamPath = strdup("/");
 }
 
 cIptvProtocolHttp::~cIptvProtocolHttp()
@@ -59,7 +59,7 @@ bool cIptvProtocolHttp::Connect(void)
         }
 
      // Ensure that socket is valid
-     OpenSocket(sockAddr.sin_addr.s_addr, socketPort);
+     OpenSocket(socketPort);
 
      int err = connect(socketDesc, (struct sockaddr *)&sockAddr, sizeof(sockAddr));
      // Non-blocking sockets always report in-progress error when connected

protocoludp.c

@@ -19,9 +19,10 @@
 #include "socket.h"
 
 cIptvProtocolUdp::cIptvProtocolUdp()
+: streamAddr(strdup("")),
+  sourceAddr(strdup(""))
 {
   debug("cIptvProtocolUdp::cIptvProtocolUdp()\n");
-  streamAddr = strdup("");
 }
 
 cIptvProtocolUdp::~cIptvProtocolUdp()
@@ -31,6 +32,7 @@ cIptvProtocolUdp::~cIptvProtocolUdp()
   cIptvProtocolUdp::Close();
   // Free allocated memory
   free(streamAddr);
+  free(sourceAddr);
 }
 
 bool cIptvProtocolUdp::JoinMulticast(void)
@@ -39,7 +41,7 @@ bool cIptvProtocolUdp::JoinMulticast(void)
   // Check that stream address is valid
   if (!isActive && !isempty(streamAddr)) {
      // Ensure that socket is valid
-     OpenSocket(inet_addr(streamAddr), socketPort);
+     OpenSocket(socketPort, isempty(sourceAddr) ? INADDR_ANY : inet_addr(sourceAddr));
      // Join a new multicast group
      struct ip_mreq mreq;
      mreq.imr_multiaddr.s_addr = inet_addr(streamAddr);
@@ -59,7 +61,7 @@ bool cIptvProtocolUdp::DropMulticast(void)
   // Check that stream address is valid
   if (isActive && !isempty(streamAddr)) {
       // Ensure that socket is valid
-      OpenSocket(inet_addr(streamAddr), socketPort);
+      OpenSocket(socketPort, isempty(sourceAddr) ? INADDR_ANY : inet_addr(sourceAddr));
       // Drop the multicast group
       struct ip_mreq mreq;
       mreq.imr_multiaddr.s_addr = inet_addr(streamAddr);
@@ -104,6 +106,13 @@ bool cIptvProtocolUdp::Set(const char* Location, const int Parameter, const int
      DropMulticast();
      // Update stream address and port
      streamAddr = strcpyrealloc(streamAddr, Location);
+     char *p = strstr(streamAddr, ";");
+     if (p) {
+        sourceAddr = strcpyrealloc(sourceAddr, p + 1);
+        *p = 0;
+        }
+    else
+        sourceAddr = strcpyrealloc(sourceAddr, "");
      socketPort = Parameter;
      // Join a new multicast group
      JoinMulticast();

protocoludp.h

@@ -15,6 +15,7 @@
 class cIptvProtocolUdp : public cIptvUdpSocket, public cIptvProtocolIf {
 private:
   char* streamAddr;
+  char* sourceAddr;
 
 private:
   bool JoinMulticast(void);

socket.c

@@ -20,11 +20,10 @@
 cIptvSocket::cIptvSocket()
 : socketDesc(-1),
   socketPort(0),
-  inetAddr(INADDR_NONE),
   isActive(false)
 {
   debug("cIptvSocket::cIptvSocket()\n");
-  memset(&sockAddr, 0, sizeof(sockAddr));
+  memset(&sockAddr, '\0', sizeof(sockAddr));
 }
 
 cIptvSocket::~cIptvSocket()
@@ -34,7 +33,7 @@ cIptvSocket::~cIptvSocket()
   CloseSocket();
 }
 
-bool cIptvSocket::OpenSocket(const in_addr_t InetAddr, const int Port, const bool isUdp)
+bool cIptvSocket::OpenSocket(const int Port, const bool isUdp)
 {
   debug("cIptvSocket::OpenSocket()\n");
   // If socket is there already and it is bound to a different port, it must
@@ -43,9 +42,6 @@ bool cIptvSocket::OpenSocket(const in_addr_t InetAddr, const int Port, const boo
      debug("cIptvSocket::OpenSocket(): Socket tear-down\n");
      CloseSocket();
      }
-  // inetAddr must be set after CloseSocket()
-  if (inetAddr != InetAddr)
-     inetAddr = InetAddr;
   // Bind to the socket if it is not active already
   if (socketDesc < 0) {
      int yes = 1;
@@ -65,7 +61,7 @@ bool cIptvSocket::OpenSocket(const in_addr_t InetAddr, const int Port, const boo
      ERROR_IF_FUNC(setsockopt(socketDesc, SOL_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0, "setsockopt(IP_PKTINFO)",
                    CloseSocket(), return false);
      // Bind socket
-     memset(&sockAddr, 0, sizeof(sockAddr));
+     memset(&sockAddr, '\0', sizeof(sockAddr));
      sockAddr.sin_family = AF_INET;
      sockAddr.sin_port = htons((uint16_t)(Port & 0xFFFF));
      sockAddr.sin_addr.s_addr = htonl(INADDR_ANY);
@@ -87,13 +83,13 @@ void cIptvSocket::CloseSocket(void)
      close(socketDesc);
      socketDesc = -1;
      socketPort = 0;
-     inetAddr = INADDR_NONE;
      memset(&sockAddr, 0, sizeof(sockAddr));
      }
 }
 
 // UDP socket class
 cIptvUdpSocket::cIptvUdpSocket()
+: sourceAddr(INADDR_ANY)
 {
   debug("cIptvUdpSocket::cIptvUdpSocket()\n");
 }
@@ -103,10 +99,18 @@ cIptvUdpSocket::~cIptvUdpSocket()
   debug("cIptvUdpSocket::~cIptvUdpSocket()\n");
 }
 
-bool cIptvUdpSocket::OpenSocket(const in_addr_t InetAddr, const int Port)
+bool cIptvUdpSocket::OpenSocket(const int Port, const in_addr_t SourceAddr)
 {
   debug("cIptvUdpSocket::OpenSocket()\n");
-  return cIptvSocket::OpenSocket(InetAddr, Port, true);
+  sourceAddr = SourceAddr;
+  return cIptvSocket::OpenSocket(Port, true);
+}
+
+void cIptvUdpSocket::CloseSocket(void)
+{
+  debug("cIptvUdpSocket::CloseSocket()\n");
+  sourceAddr = INADDR_ANY;
+  cIptvSocket::CloseSocket();
 }
 
 int cIptvUdpSocket::Read(unsigned char* BufferAddr, unsigned int BufferLen)
@@ -137,17 +141,18 @@ int cIptvUdpSocket::Read(unsigned char* BufferAddr, unsigned int BufferLen)
   // Read data from socket
   if (isActive && socketDesc && BufferAddr && (BufferLen > 0))
      len = (int)recvmsg(socketDesc, &msgh, MSG_DONTWAIT);
-  if (len < 0)
+  ERROR_IF_RET(len < 0, "recvmsg()", return -1);
-     return -1;
+  if (len > 0) {
-  else if (len > 0) {
      // Process auxiliary received data and validate source address
-     for (cmsg = CMSG_FIRSTHDR(&msgh); cmsg != NULL; cmsg = CMSG_NXTHDR(&msgh, cmsg)) {
+     for (cmsg = CMSG_FIRSTHDR(&msgh); (sourceAddr != INADDR_ANY) && (cmsg != NULL); cmsg = CMSG_NXTHDR(&msgh, cmsg)) {
          if ((cmsg->cmsg_level == SOL_IP) && (cmsg->cmsg_type == IP_PKTINFO)) {
             struct in_pktinfo *i = (struct in_pktinfo *)CMSG_DATA(cmsg);
-            if (i->ipi_addr.s_addr != inetAddr)
+            if (i->ipi_addr.s_addr != sourceAddr) {
+               //debug("Discard packet due to invalid source address: %s", inet_ntoa(i->ipi_addr));
                return 0;
                }
             }
+         }
      if (BufferAddr[0] == TS_SYNC_BYTE)
         return len;
      else if (len > 3) {
@@ -193,10 +198,10 @@ cIptvTcpSocket::~cIptvTcpSocket()
   debug("cIptvTcpSocket::~cIptvTcpSocket()\n");
 }
 
-bool cIptvTcpSocket::OpenSocket(const in_addr_t InetAddr, const int Port)
+bool cIptvTcpSocket::OpenSocket(const int Port)
 {
   debug("cIptvTcpSocket::OpenSocket()\n");
-  return cIptvSocket::OpenSocket(InetAddr, Port, false);
+  return cIptvSocket::OpenSocket(Port, false);
 }
 
 int cIptvTcpSocket::Read(unsigned char* BufferAddr, unsigned int BufferLen)
@@ -213,7 +218,5 @@ int cIptvTcpSocket::Read(unsigned char* BufferAddr, unsigned int BufferLen)
   if (isActive && socketDesc && BufferAddr && (BufferLen > 0))
      len = (int)recvfrom(socketDesc, BufferAddr, BufferLen, MSG_DONTWAIT,
                          (struct sockaddr *)&sockAddr, &addrlen);
-  //if (inetAddr != sockAddr.sin_addr.s_addr)
-  //   return -1;
   return len;
 }

socket.h

@@ -14,12 +14,11 @@ class cIptvSocket {
 protected:
   int socketDesc;
   int socketPort;
-  in_addr_t inetAddr;
   struct sockaddr_in sockAddr;
   bool isActive;
 
 protected:
-  bool OpenSocket(const in_addr_t InetAddr, const int Port, const bool isUdp);
+  bool OpenSocket(const int Port, const bool isUdp);
   void CloseSocket(void);
 
 public:
@@ -28,11 +27,15 @@ public:
 };
 
 class cIptvUdpSocket : public cIptvSocket {
+private:
+  in_addr_t sourceAddr;
+
 public:
   cIptvUdpSocket();
   virtual ~cIptvUdpSocket();
   virtual int Read(unsigned char* BufferAddr, unsigned int BufferLen);
-  bool OpenSocket(const in_addr_t InetAddr, const int Port);
+  bool OpenSocket(const int Port, const in_addr_t SourceAddr = INADDR_ANY);
+  void CloseSocket(void);
 };
 
 class cIptvTcpSocket : public cIptvSocket {
@@ -40,7 +43,7 @@ public:
   cIptvTcpSocket();
   virtual ~cIptvTcpSocket();
   virtual int Read(unsigned char* BufferAddr, unsigned int BufferLen);
-  bool OpenSocket(const in_addr_t InetAddr, const int Port);
+  bool OpenSocket(const int Port);
 };
 
 #endif // __IPTV_SOCKET_H