Initial commit

1 files changed, 187 insertions, 0 deletions

diff --git a/filter.cpp b/filter.cpp
new file mode 100644
index 0000000..7a3bc89
--- /dev/null
+++ b/filter.cpp
@@ -0,0 +1,187 @@
+/*
+ * filter.cpp: A plugin for the Video Disk Recorder
+ *
+ * See the README file for copyright information and how to reach the author.
+ *
+ * $Id$
+ */
+
+#include <netinet/if_ether.h>
+#include <unistd.h>
+
+#include "filter.h"
+
+#undef WRITE_RAW
+
+cFilterInfosatepg::cFilterInfosatepg(cGlobalInfosatepg *Global)
+{
+  global = Global;
+  Set(global->Pid,0,0);
+}
+
+u_long cFilterInfosatepg::do_sum(u_long sum, u_char *buf, int nBytes)
+{
+  int nleft=nBytes;
+  u_short *w = (u_short*)buf;
+
+  while (nleft > 1)
+  {
+    sum += *w++;
+    nleft -= 2;
+  }
+
+  if (nleft == 1)
+  {
+    u_short answer = 0;
+    *(u_char*)(&answer) = *(u_char*)w;
+    sum += answer;
+  }
+  return sum;
+}
+
+u_short cFilterInfosatepg::foldsum(u_long sum)
+{
+  while (sum>>16)
+    sum = (sum >> 16) + (sum & 0xFFFF);
+
+  return ((u_short) ~sum);
+}
+
+u_short cFilterInfosatepg::IPChecksum(iphdr *ipHeader)
+{
+  return foldsum(do_sum(0, (u_char*) ipHeader, sizeof(iphdr)));
+
+}   /* IpChecksum() */
+
+
+u_short cFilterInfosatepg::UDPChecksum(iphdr *ipHeader, udphdr *udpHeader)
+{
+  u_long sum = 0;
+
+  // Ip-Pseudo-Header
+  sum = do_sum(sum, (u_char*)(&ipHeader->saddr), sizeof(ipHeader->saddr));
+  sum = do_sum(sum, (u_char*)(&ipHeader->daddr), sizeof(ipHeader->daddr));
+  sum += udpHeader->len;
+  sum += ipHeader->protocol<<8;
+
+  sum = do_sum(sum, (u_char*)udpHeader, ntohs(udpHeader->len));
+
+  return foldsum(sum);
+}
+
+
+void cFilterInfosatepg::Process(u_short Pid, u_char Tid, const u_char *Data, int Length)
+{
+#define SECT_IP_HDR_START  12
+#define SECT_UDP_HDR_START 32
+#define SECT_IS_HDR_START  40
+#define SECT_IS_DATA_START 52
+
+  if (Data[0]!=0x3E) return;
+
+  struct ethhdr eth_hdr;
+  memset(&eth_hdr,0,sizeof(struct ethhdr));
+
+  eth_hdr.h_dest[0]=Data[11];
+  eth_hdr.h_dest[1]=Data[10];
+  eth_hdr.h_dest[2]=Data[9];
+  eth_hdr.h_dest[3]=Data[8];
+  eth_hdr.h_dest[4]=Data[4];
+  eth_hdr.h_dest[5]=Data[3];
+
+  if (!global->CheckMAC(&eth_hdr)) return;
+
+  int mac = eth_hdr.h_dest[5];
+
+  struct iphdr *ip_hdr = (iphdr *) &Data[SECT_IP_HDR_START];
+  struct udphdr *udp_hdr = (udphdr *) &Data[SECT_UDP_HDR_START];
+
+  // Only IPv4
+  if (ip_hdr->version!=4) return;
+
+  // Check IP checksum
+  if (IPChecksum(ip_hdr)!=0)
+  {
+    dsyslog("infosatepg: ip checksum error");
+    return;
+  }
+
+  // Only UDP
+  if (ip_hdr->protocol!=17) return;
+
+  // Check UDP checksum
+  if (UDPChecksum(ip_hdr,udp_hdr)!=0)
+  {
+    dsyslog("infosatepg: udp checksum error");
+    return;
+  }
+
+  struct infosathdr *ishdr = (struct infosathdr*) &Data[SECT_IS_HDR_START];
+
+  if (ntohs(ishdr->technisatId)!=0x0001) return;
+
+  const u_char *infosatdata = &Data[SECT_IS_DATA_START];
+  int len = Length - SECT_IS_DATA_START-4;
+
+  char file[1024];
+  snprintf(file,sizeof(file),"%s/infosatepg%02i%02i_%03i.dat",global->Directory(),ishdr->day,ishdr->month,
+           ntohs(ishdr->pktcnt));
+
+  if (global->Infosatdata[mac].NeverSeen(ishdr->day,ishdr->month,ntohs(ishdr->pktcnt)))
+  {
+    // never seen such a packet -> init structure
+    global->Infosatdata[mac].Init(file,ishdr->day,ishdr->month,ntohs(ishdr->pktcnt));
+  }
+
+  // Check if we already have this packet
+  if (global->Infosatdata[mac].GetBit(ntohs(ishdr->pktnr))) return;
+
+  // set bit in Infosatdata bitfield
+  global->Infosatdata[mac].SetBit(ntohs(ishdr->pktnr),true);
+
+#ifdef VDRDEBUG
+  dsyslog("infosatepg: mac=%02x-%02x-%02x-%02x-%02x-%02x",eth_hdr.h_dest[0],eth_hdr.h_dest[1],
+          eth_hdr.h_dest[2],eth_hdr.h_dest[3],eth_hdr.h_dest[4],eth_hdr.h_dest[5] );
+
+  dsyslog("infosatepg: tid=%04i tbl=%04i stbl=%04i day=%02i month=%02i pktnr=%03i pktcnt=%03i len=%i",
+          ntohs(ishdr->technisatId),ishdr->tableId,ishdr->tablesubId,ishdr->day,
+          ishdr->month, ntohs(ishdr->pktnr), ntohs(ishdr->pktcnt), len);
+
+  dsyslog("infosatepg: save to %s", file);
+#endif
+
+  int f=open(file,O_RDWR|O_CREAT,0664);
+  if (f==-1)
+  {
+    if (errno!=ENOSPC)
+    {
+      esyslog("infosatepg: unable to create file '%s'", file);
+    }
+    return;
+  }
+  off_t offset = (off_t) (ntohs(ishdr->pktnr)*1400);
+  if (lseek(f,offset,SEEK_SET)!=(off_t) -1)
+  {
+#ifdef VDRDEBUG
+    dsyslog("infosatepg: writing to %li",offset);
+#endif
+    write(f,infosatdata,len);
+  }
+  close(f);
+
+#ifdef WRITE_RAW
+  sprintf(file,"%s/%03i.dat",dir,ntohs(ishdr->pktnr));
+  f=open(file,O_RDWR|O_CREAT,0664);
+  if (f==-1) return;
+  write(f,Data,Length);
+  close(f);
+#endif
+
+  // check if we have all packets
+  if (global->Infosatdata[mac].ReceivedAll())
+  {
+    // we have all packets
+    isyslog("infosatepg: day=%02i month=%02i fully received", ishdr->day,ishdr->month);
+  }
+
+}