Impose memory usage limit on external filters. Fixes issue #259

src/common/autoconfig.h.in

@@ -20,6 +20,9 @@
 #undef HAVE_POSIX_SPAWN
 #undef USE_POSIX_SPAWN
 
+/* Define to 1 if you have the setrlimit() call. */
+#undef HAVE_SETRLIMIT
+
 /* Define to 1 if you have the <inttypes.h> header file. */
 #undef HAVE_INTTYPES_H
 

src/configure.ac

@@ -34,7 +34,7 @@ AC_SYS_LARGEFILE
 # OpenBSD needs sys/param.h for mount.h to compile
 AC_CHECK_HEADERS([sys/param.h, spawn.h])
 
-AC_CHECK_FUNCS([posix_spawn])
+AC_CHECK_FUNCS([posix_spawn, setrlimit])
 
 if test "x$ac_cv_func_posix_spawn" = xyes; then :
    AC_ARG_ENABLE(posix_spawn,

src/doc/user/usermanual.xml

@@ -6022,18 +6022,29 @@ mondelaypatterns = *.log:20 "this one has spaces*:10"
               </listitem>
            </varlistentry>
 
-            <varlistentry><term><varname>monioniceclass, monioniceclassdata
+           <varlistentry><term><varname>monioniceclass, monioniceclassdata
-             </varname></term><listitem><para>These allow defining the
+           </varname></term><listitem><para>These allow defining the
-             <application>ionice</application> class and data used by the
+           <application>ionice</application> class and data used by the
-             indexer (default class 3, no data).</para>
+           indexer (default class 3, no data).</para>
-              </listitem>
+         </listitem>
-            </varlistentry>
+           </varlistentry>
+
+           <varlistentry><term><varname>filtermaxseconds</varname></term>
+           <listitem><para>Maximum handler execution time, after which it
+           is aborted. Some postscript programs just loop...</para> 
+           </listitem>
+           </varlistentry>
+
+           <varlistentry><term><varname>filtermaxmbytes</varname></term>
+           <listitem><para>&RCL; 1.20.7 and later. Maximum handler memory
+           utilisation. This uses setrlimit(RLIMIT_AS) on most systems
+           (total virtual memory space size limit). Some programs may start
+           with 500 MBytes of mapped shared libraries, so take this into
+           account when choosing a value. The default is a liberal
+           2000MB.</para>
+           </listitem>
+           </varlistentry>
 
-            <varlistentry><term><varname>filtermaxseconds</varname></term>
-              <listitem><para>Maximum handler execution time, after which it
-            is aborted. Some postscript programs just loop...</para> 
-              </listitem>
-            </varlistentry>
           <varlistentry><term><varname>filtersdir</varname></term>
             <listitem><para>A directory to search for the external
             input handler scripts used to index some types of files. The

src/internfile/mh_exec.cpp

@@ -77,6 +77,8 @@ bool MimeHandlerExec::next_document()
 
     int filtermaxseconds = 900;
     m_config->getConfParam("filtermaxseconds", &filtermaxseconds);
+    int filtermaxmbytes = 0;
+    m_config->getConfParam("filtermaxmbytes", &filtermaxmbytes);
 
     if (params.empty()) {
 	// Hu ho
@@ -103,6 +105,7 @@ bool MimeHandlerExec::next_document()
     mexec.putenv("RECOLL_CONFDIR", m_config->getConfDir());
     mexec.putenv(m_forPreview ? "RECOLL_FILTER_FORPREVIEW=yes" :
 		"RECOLL_FILTER_FORPREVIEW=no");
+    mexec.setrlimit_as(filtermaxmbytes);
 
     int status;
     try {

src/internfile/mh_execm.cpp

@@ -47,6 +47,9 @@ bool MimeHandlerExecMultiple::startCmd()
     // Command name
     string cmd = params.front();
     
+    int filtermaxmbytes = 0;
+    m_config->getConfParam("filtermaxmbytes", &filtermaxmbytes);
+
     m_maxmemberkb = 50000;
     m_config->getConfParam("membermaxkbs", &m_maxmemberkb);
     ostringstream oss;
@@ -57,6 +60,8 @@ bool MimeHandlerExecMultiple::startCmd()
     m_cmd.putenv(m_forPreview ? "RECOLL_FILTER_FORPREVIEW=yes" :
 		"RECOLL_FILTER_FORPREVIEW=no");
 
+    m_cmd.setrlimit_as(filtermaxmbytes);
+
     // Build parameter list: delete cmd name
     vector<string>myparams(params.begin() + 1, params.end());
 

src/sampleconf/recoll.conf.in

@@ -250,6 +250,11 @@ textfilepagekbs = 1000
 # Maximum external filter execution time. Default 20mn. This is mainly
 # to avoid infinite loops in postscript files (loop.ps)
 filtermaxseconds = 1200
+# Maximum virtual memory space for filter process (setrlimit(RLIMIT_AS)),
+# in megabytes. Note that this includes any mapped libs (there is no
+# reliable Linux way to limit the data space only), so we need to be a
+# bit generous here. Anything over 2000 will be ignored on 32 bits machines.
+filtermaxmbytes = 2000
 
 # Length of abstracts we store while indexing. Longer will make for a
 # bigger db

src/utils/execmd.cpp

@@ -28,6 +28,8 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <sys/select.h>
+#include <sys/time.h>
+#include <sys/resource.h>
 #include <fcntl.h>
 #include <errno.h>
 #include <signal.h>
@@ -300,6 +302,39 @@ inline void ExecCmd::dochild(const string &cmd, const char **argv,
     pthread_sigmask(SIG_UNBLOCK, &sset, 0);
     sigprocmask(SIG_UNBLOCK, &sset, 0);
 
+#ifdef HAVE_SETRLIMIT
+#if defined RLIMIT_AS || defined RLIMIT_VMEM || defined RLIMIT_DATA
+    if (m_rlimit_as_mbytes > 2000 && sizeof(rlim_t) < 8) {
+	// Impossible limit, don't use it
+	m_rlimit_as_mbytes = 0;
+    }
+    if (m_rlimit_as_mbytes > 0) {
+	struct rlimit ram_limit = {
+	    static_cast<rlim_t>(m_rlimit_as_mbytes * 1024 * 1024),
+	    RLIM_INFINITY
+	};
+	int resource;
+
+	// RLIMIT_AS and RLIMIT_VMEM are usually synonyms when VMEM is
+	// defined. RLIMIT_AS is Posix. Both don't really do what we
+	// want, because they count e.g. shared lib mappings, which we
+	// don't really care about.
+	// RLIMIT_DATA only limits the data segment. Modern mallocs
+	// use mmap and will not be bound. (Otoh if we only have this,
+	// we're probably not modern).
+	// So we're unsatisfied either way.
+#ifdef RLIMIT_AS
+	resource = RLIMIT_AS;
+#elif defined RLIMIT_VMEM
+	resource = RLIMIT_VMEM;
+#else
+	resource = RLIMIT_DATA;
+#endif
+	setrlimit(resource, &ram_limit);
+    }
+#endif
+#endif // have_setrlimit
+
     if (has_input) {
 	close(m_pipein[1]);
 	if (m_pipein[0] != 0) {
@@ -347,6 +382,11 @@ inline void ExecCmd::dochild(const string &cmd, const char **argv,
     _exit(127);
 }
 
+void ExecCmd::setrlimit_as(int mbytes)
+{
+    m_rlimit_as_mbytes = mbytes;
+}
+
 int ExecCmd::startExec(const string &cmd, const vector<string>& args,
 		       bool has_input, bool has_output)
 {
@@ -427,6 +467,7 @@ int ExecCmd::startExec(const string &cmd, const vector<string>& args,
 //////////////////////////////// End vfork child prepare section.
 
 #if HAVE_POSIX_SPAWN && USE_POSIX_SPAWN
+    // Note that posix_spawn provides no way to setrlimit() the child.
     {
         posix_spawnattr_t attrs;
         posix_spawnattr_init (&attrs);

src/utils/execmd.h

@@ -83,6 +83,14 @@ class ExecCmd {
     void putenv(const std::string &envassign);
     void putenv(const std::string &name, const std::string& value);
 
+    /** 
+     * Try to set a limit on child process vm size. This will use
+     * setrlimit() and RLIMIT_AS/VMEM if available. Parameter is in
+     * units of 2**10. Must be called before starting the command, default 
+     * is inherit from parent.
+     */
+    void setrlimit_as(int mbytes);
+
     /** 
      * Set function objects to call whenever new data is available or on
      * select timeout / whenever new data is needed to send. Must be called
@@ -158,7 +166,7 @@ class ExecCmd {
     void zapChild() {setKill(); (void)wait();}
 
     ExecCmd()
-	: m_advise(0), m_provide(0), m_timeoutMs(1000)
+	: m_advise(0), m_provide(0), m_timeoutMs(1000), m_rlimit_as_mbytes(0)
     {
 	reset();
     }
@@ -191,6 +199,7 @@ class ExecCmd {
     ExecCmdProvide  *m_provide;
     bool             m_killRequest;
     int              m_timeoutMs;
+    int              m_rlimit_as_mbytes;
     std::string           m_stderrFile;
     // Pipe for data going to the command
     int              m_pipein[2];