shutdown-wrapper is a wrapper which tests the shutdown-hooks

Author: flensrocker

HISTORY

@@ -103,3 +103,8 @@ VDR Plugin 'dbus2vdr' Revision History
 2012-02-08: Version 0.0.3h
 
 - add "AskUser" to remote interface
+
+2012-02-19: Version 0.0.3i
+
+- shutdown-wrapper is a wrapper which tests the shutdown-hooks
+  set its SUID bit if needed

Makefile

@@ -56,6 +56,7 @@ DEFINES += -D_GNU_SOURCE -DPLUGIN_NAME_I18N='"$(PLUGIN)"'
 ### The object files (add further files here):
 
 OBJS = $(PLUGIN).o epg.o helper.o message.o monitor.o plugin.o recording.o remote.o setup.o shutdown.o skin.o timer.o
+SWOBJS = libvdr-exitpipe.o libvdr-i18n.o libvdr-thread.o libvdr-tools.o shutdown-wrapper.o
 
 ### The main target:
 
@@ -87,7 +88,7 @@ I18Npot   = $(PODIR)/$(PLUGIN).pot
 %.mo: %.po
 	msgfmt -c -o $@ $<
 
-$(I18Npot): $(wildcard *.c)
+$(I18Npot): $(patsubst %.o,%.c,$(OBJS))
 	xgettext -C -cTRANSLATORS --no-wrap --no-location -k -ktr -ktrNOOP --package-name=vdr-$(PLUGIN) --package-version=$(VERSION) --msgid-bugs-address='<see README>' -o $@ $^
 
 %.po: $(I18Npot)
@@ -104,7 +105,10 @@ i18n: $(I18Nmsgs) $(I18Npot)
 
 ### Targets:
 
-libvdr-$(PLUGIN).so: $(OBJS)
+shutdown-wrapper: $(SWOBJS)
+	$(CXX) $(CXXFLAGS) $(LDFLAGS) $(SWOBJS) -ljpeg -lrt -pthread -o $@
+
+libvdr-$(PLUGIN).so: $(OBJS) shutdown-wrapper
 	$(CXX) $(CXXFLAGS) $(LDFLAGS) -shared $(OBJS) $(LDADD) -o $@
 	@cp --remove-destination $@ $(LIBDIR)/$@.$(APIVERSION)
 
@@ -117,4 +121,5 @@ dist: $(I18Npo) clean
 	@echo Distribution package created as $(PACKAGE).tgz
 
 clean:
-	@-rm -f $(OBJS) $(DEPFILE) *.so *.tgz core* *~ $(PODIR)/*.mo $(PODIR)/*.pot
+	@-rm -f $(OBJS) $(SWOBJS) shutdown-wrapper $(DEPFILE) *.so *.tgz core* *~ $(PODIR)/*.mo $(PODIR)/*.pot
+

README

@@ -45,6 +45,8 @@ Commandline Arguments
 -s, --shutdown-hooks=/path/to/shutdown-hooks
         uses all files in the given directory as shutdown-hooks
         usually it's /usr/share/vdr/shutdown-hooks
+-w, --shutdown-hooks-wrapper=/path/to/shutdown-hooks-wrapper
+        path to a program that will call the shutdown-hooks with suid
 
 Implemented features
 --------------------
@@ -121,6 +123,8 @@ If the SVDRP command doesn't take a parameter you can ommit it or pass an empty
 
   You may shutdown vdr on reply codes 250 and 990.
   If SHUTDOWNCMD is given use this command for shutdown.
+  'shutdown-wrapper' is a tool which calls the shutdown-hooks.
+  If the hooks need elevated privileges set the SUID bit of the wrapper accordingly.
 
 - list all supported parameters from setup.conf
   vdr-dbus-send.sh /Setup setup.List

dbus2vdr.c

@@ -21,7 +21,7 @@
 #include <vdr/osdbase.h>
 #include <vdr/plugin.h>
 
-static const char *VERSION        = "0.0.3h";
+static const char *VERSION        = "0.0.3i";
 static const char *DESCRIPTION    = trNOOP("control vdr via D-Bus");
 static const char *MAINMENUENTRY  = NULL;
 
@@ -67,20 +67,23 @@ const char *cPluginDbus2vdr::CommandLineHelp(void)
 {
   return "  --shutdown-hooks=/path/to/dir/with/shutdown-hooks\n"
          "    directory with shutdown-hooks to be called by ConfirmShutdown\n"
-         "    usually it's /usr/share/vdr/shutdown-hooks";
+         "    usually it's /usr/share/vdr/shutdown-hooks\n"
+         "  --shutdown-hooks-wrapper=/path/to/shutdown-hooks-wrapper\n"
+         "    path to a program that will call the shutdown-hooks with suid";
 }
 
 bool cPluginDbus2vdr::ProcessArgs(int argc, char *argv[])
 {
   static struct option options[] =
   {
     {"shutdown-hooks", required_argument, 0, 's'},
+    {"shutdown-hooks-wrapper", required_argument, 0, 'w'},
     {0, 0, 0, 0}
   };
 
   while (true) {
         int option_index = 0;
-        int c = getopt_long(argc, argv, "s:", options, &option_index);
+        int c = getopt_long(argc, argv, "s:w:", options, &option_index);
         if (c == -1)
            break;
         switch (c) {
@@ -92,6 +95,14 @@ bool cPluginDbus2vdr::ProcessArgs(int argc, char *argv[])
                 }
              break;
            }
+          case 'w':
+           {
+             if (optarg != NULL) {
+                isyslog("dbus2vdr: use shutdown-hooks-wrapper %s", optarg);
+                cDBusMessageShutdown::SetShutdownHooksWrapper(optarg);
+                }
+             break;
+           }
           }
         }
   return true;

libvdr-exitpipe.c

@@ -0,0 +1,114 @@
+#include "libvdr-exitpipe.h"
+
+#include "libvdr-thread.h"
+
+#include <sys/wait.h>
+#include <unistd.h>
+
+
+cExitPipe::cExitPipe(void)
+{
+  pid = -1;
+  f = NULL;
+}
+
+cExitPipe::~cExitPipe()
+{
+  Close();
+}
+
+bool cExitPipe::Open(const char *Command, const char *Mode)
+{
+  int fd[2];
+
+  if (pipe(fd) < 0) {
+     LOG_ERROR;
+     return false;
+     }
+  if ((pid = fork()) < 0) { // fork failed
+     LOG_ERROR;
+     close(fd[0]);
+     close(fd[1]);
+     return false;
+     }
+
+  const char *mode = "w";
+  int iopipe = 0;
+
+  if (pid > 0) { // parent process
+     if (strcmp(Mode, "r") == 0) {
+        mode = "r";
+        iopipe = 1;
+        }
+     close(fd[iopipe]);
+     if ((f = fdopen(fd[1 - iopipe], mode)) == NULL) {
+        LOG_ERROR;
+        close(fd[1 - iopipe]);
+        }
+     return f != NULL;
+     }
+  else { // child process
+     int iofd = STDOUT_FILENO;
+     if (strcmp(Mode, "w") == 0) {
+        mode = "r";
+        iopipe = 1;
+        iofd = STDIN_FILENO;
+        }
+     close(fd[iopipe]);
+     if (dup2(fd[1 - iopipe], iofd) == -1) { // now redirect
+        LOG_ERROR;
+        close(fd[1 - iopipe]);
+        _exit(-1);
+        }
+     else {
+        int MaxPossibleFileDescriptors = getdtablesize();
+        for (int i = STDERR_FILENO + 1; i < MaxPossibleFileDescriptors; i++)
+            close(i); //close all dup'ed filedescriptors
+        if (execl("/bin/sh", "sh", "-c", Command, NULL) == -1) {
+           LOG_ERROR_STR(Command);
+           close(fd[1 - iopipe]);
+           _exit(-1);
+           }
+        }
+     _exit(0);
+     }
+}
+
+int cExitPipe::Close(void)
+{
+  int ret = -1;
+
+  if (f) {
+     fclose(f);
+     f = NULL;
+     }
+
+  if (pid > 0) {
+     int status = 0;
+     int i = 5;
+     while (i > 0) {
+           ret = waitpid(pid, &status, WNOHANG);
+           if (ret < 0) {
+              if (errno != EINTR && errno != ECHILD) {
+                 LOG_ERROR;
+                 break;
+                 }
+              }
+           else if (ret == pid)
+              break;
+           i--;
+           cCondWait::SleepMs(100);
+           }
+     if (!i) {
+        kill(pid, SIGKILL);
+        ret = -1;
+        }
+     else if (ret == -1 || !WIFEXITED(status))
+        ret = -1;
+     else if (WIFEXITED(status))
+        ret = WEXITSTATUS(status);
+     pid = -1;
+     }
+
+  return ret;
+}

libvdr-exitpipe.h

@@ -0,0 +1,19 @@
+#ifndef __DBUS2VDR_EXITPIPE_H
+#define __DBUS2VDR_EXITPIPE_H
+
+#include "libvdr-tools.h"
+
+// copy of vdr's cPipe but returns exit code of child on Close
+class cExitPipe
+{
+private:
+  pid_t pid;
+  FILE *f;
+public:
+  cExitPipe(void);
+  ~cExitPipe();
+  operator FILE* () { return f; }
+  bool Open(const char *Command, const char *Mode);
+  int Close(void);
+};
+#endif