Robustify accesses to server config

lib/defines.h

@@ -126,6 +126,7 @@ static inline void show_stackframe(){}
 
 #define SHM_STREAM_INDEX "MstSTRM%s" //%s stream name
 #define SHM_STREAM_STATE "MstSTATE%s" //%s stream name
+#define SHM_STREAM_CONF "MstSCnf%s" //%s stream name
 #define STRMSTAT_OFF 0
 #define STRMSTAT_INIT 1
 #define STRMSTAT_BOOT 2
@@ -139,11 +140,10 @@ static inline void show_stackframe(){}
 #define SHM_TRACK_DATA "MstDATA%s@%lu_%lu" //%s stream name, %lu track ID, %lu page #
 #define SHM_STATISTICS "MstSTAT"
 #define SHM_USERS "MstUSER%s" //%s stream name
-#define SHM_TRIGGER "MstTRIG%s" //%s trigger name
 #define SEM_LIVE "/MstLIVE%s" //%s stream name
 #define SEM_INPUT "/MstInpt%s" //%s stream name
-#define SEM_CONF "/MstConfLock"
-#define SHM_CONF "MstConf"
+#define SHM_CAPA "MstCapa"
+#define SHM_PROTO "MstProt"
 #define SHM_STATE_LOGS "MstStateLogs"
 #define SHM_STATE_ACCS "MstStateAccs"
 #define SHM_STATE_STREAMS "MstStateStreams"

lib/stream.cpp

@@ -79,20 +79,17 @@ JSON::Value Util::getStreamConfig(const std::string & streamname){
     FAIL_MSG("Stream opening denied: %s is longer than 100 characters (%lu).", streamname.c_str(), streamname.size());
     return result;
   }
-  IPC::sharedPage mistConfOut(SHM_CONF, DEFAULT_CONF_PAGE_SIZE, false, false);
-  IPC::semaphore configLock(SEM_CONF, O_CREAT | O_RDWR, ACCESSPERMS, 1);
-  configLock.wait();
-  DTSC::Scan config = DTSC::Scan(mistConfOut.mapped, mistConfOut.len);
   std::string smp = streamname.substr(0, streamname.find_first_of("+ "));
-  //check if smp (everything before + or space) exists
-  DTSC::Scan stream_cfg = config.getMember("streams").getMember(smp);
+
+  char tmpBuf[NAME_BUFFER_SIZE];
+  snprintf(tmpBuf, NAME_BUFFER_SIZE, SHM_STREAM_CONF, smp.c_str());
+  Util::DTSCShmReader rStrmConf(tmpBuf);
+  DTSC::Scan stream_cfg = rStrmConf.getScan();
   if (!stream_cfg){
-    DEBUG_MSG(DLVL_MEDIUM, "Stream %s not configured", streamname.c_str());
-  }else{
-    result = stream_cfg.asJSON();
+    WARN_MSG("Could not get stream '%s' config!", smp.c_str());
+    return result;
   }
-  configLock.post();//unlock the config semaphore
-  return result;
+  return stream_cfg.asJSON();
 }
 
 DTSC::Meta Util::getStreamMeta(const std::string & streamname){
@@ -281,22 +278,17 @@ JSON::Value Util::getInputBySource(const std::string &filename, bool isProvider)
   JSON::Value ret;
 
   //Attempt to load up configuration and find this stream
-  IPC::sharedPage mistConfOut(SHM_CONF, DEFAULT_CONF_PAGE_SIZE);
-  IPC::semaphore configLock(SEM_CONF, O_CREAT | O_RDWR, ACCESSPERMS, 1);
-  //Lock the config to prevent race conditions and corruption issues while reading
-  configLock.wait();
-  DTSC::Scan config = DTSC::Scan(mistConfOut.mapped, mistConfOut.len);
-  //Abort if no config available
-  if (!config){
-    FAIL_MSG("Configuration not available, aborting! Is MistController running?");
-    configLock.post();//unlock the config semaphore
+  Util::DTSCShmReader rCapa(SHM_CAPA);
+  DTSC::Scan inputs = rCapa.getMember("inputs");
+  //Abort if not available
+  if (!inputs){
+    FAIL_MSG("Capabilities not available, aborting! Is MistController running?");
     return false;
   }
 
-  //check in curConf for capabilities-inputs-<naam>-priority/source_match
+  //check in curConf for <naam>-priority/source_match
   bool selected = false;
   long long int curPrio = -1;
-  DTSC::Scan inputs = config.getMember("capabilities").getMember("inputs");
   DTSC::Scan input;
   unsigned int input_size = inputs.getSize();
   bool noProviderNoPick = false;
@@ -350,7 +342,6 @@ JSON::Value Util::getInputBySource(const std::string &filename, bool isProvider)
   }else{
     ret = input.asJSON();
   }
-  configLock.post();//unlock the config semaphore
   return ret;
 }
 
@@ -362,3 +353,18 @@ uint8_t Util::getStreamStatus(const std::string & streamname){
   return streamStatus.mapped[0];
 }
 
+Util::DTSCShmReader::DTSCShmReader(const std::string &pageName){
+  rPage.init(pageName, 0);
+  if (rPage){
+    rAcc = Util::RelAccX(rPage.mapped);
+  }
+}
+
+DTSC::Scan Util::DTSCShmReader::getMember(const std::string &indice){
+  return DTSC::Scan(rAcc.getPointer("dtsc_data"), rAcc.getSize("dtsc_data")).getMember(indice.c_str());
+}
+
+DTSC::Scan Util::DTSCShmReader::getScan(){
+  return DTSC::Scan(rAcc.getPointer("dtsc_data"), rAcc.getSize("dtsc_data"));
+}
+

lib/stream.h

@@ -6,6 +6,8 @@
 #include "socket.h"
 #include "json.h"
 #include "dtsc.h"
+#include "shared_memory.h"
+#include "util.h"
 
 namespace Util {
   std::string getTmpFolder();
@@ -16,5 +18,16 @@ namespace Util {
   JSON::Value getInputBySource(const std::string & filename, bool isProvider = false);
   DTSC::Meta getStreamMeta(const std::string & streamname);
   uint8_t getStreamStatus(const std::string & streamname);
+
+  class DTSCShmReader{
+    public:
+      DTSCShmReader(const std::string &pageName);
+      DTSC::Scan getMember(const std::string &indice);
+      DTSC::Scan getScan();
+    private:
+      IPC::sharedPage rPage;
+      Util::RelAccX rAcc;
+  };
+
 }
 

lib/util.cpp

@@ -6,6 +6,7 @@
 #include "defines.h"
 #include "timing.h"
 #include "procs.h"
+#include "dtsc.h"
 #include <errno.h> // errno, ENOENT, EEXIST
 #include <iostream>
 #include <iomanip>
@@ -564,6 +565,13 @@ namespace Util{
             r << std::endl;
             break;
           }
+          case RAX_DTSC:{
+            char * ptr = getPointer(it->first, i);
+            size_t sz = getSize(it->first, i);
+            r << std::endl;
+            r << DTSC::Scan(ptr, sz).toPrettyString(indent+6) << std::endl;
+            break;
+          }
           default: r << "[UNIMPLEMENTED]" << std::endl; break;
         }
       }

lib/util.h

@@ -74,6 +74,7 @@ namespace Util{
   #define RAX_RAW 0x40
   #define RAX_256RAW 0x44
   #define RAX_512RAW 0x45
+  #define RAX_DTSC 0x50
 
   /// Reliable Access class.
   /// Provides reliable access to memory data structures, using dynamic static offsets and a status