Added support for setrlimit(2)

config.h.in

@@ -151,6 +151,9 @@
 /* Define to 1 if you have the `setreuid' function. */
 #undef HAVE_SETREUID
 
+/* Define to 1 if you have the `setrlimit' function. */
+#undef HAVE_SETRLIMIT
+
 /* Define to 1 if you have the `signalfd' function. */
 #undef HAVE_SIGNALFD
 

configure

@@ -14272,7 +14272,7 @@ cat >>confdefs.h <<_ACEOF
 _ACEOF
 
 
-for ac_func in memset select setresuid setreuid strerror getpwnam_r
+for ac_func in memset select setresuid setreuid strerror getpwnam_r setrlimit
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"

configure.ac

@@ -153,7 +153,7 @@ dnl Checks for library functions.
 AC_FUNC_FORK
 AC_FUNC_SELECT_ARGTYPES
 AC_TYPE_SIGNAL
-AC_CHECK_FUNCS([memset select setresuid setreuid strerror getpwnam_r])
+AC_CHECK_FUNCS([memset select setresuid setreuid strerror getpwnam_r setrlimit])
 
 dnl Check for select() into ws2_32 for Msys/Mingw
 if test "$ac_cv_func_select" != "yes"; then

src/jconf.c

@@ -183,6 +183,10 @@ jconf_t *read_jconf(const char* file)
             {
                 conf.fast_open = value->u.boolean;
             }
+            else if (strcmp(name, "nofile") == 0)
+            {
+                conf.nofile = value->u.integer;
+            }
         }
     }
     else

src/jconf.h

@@ -44,6 +44,7 @@ typedef struct
     char *method;
     char *timeout;
     int  fast_open;
+    int  nofile;
 } jconf_t;
 
 jconf_t *read_jconf(const char* file);

src/local.c

@@ -74,6 +74,9 @@ int acl = 0;
 int verbose = 0;
 int udprelay = 0;
 static int fast_open = 0;
+#ifdef HAVE_SETRLIMIT
+static int nofile = 0;
+#endif
 
 #ifndef __MINGW32__
 static int setnonblocking(int fd)
@@ -1025,6 +1028,21 @@ int main (int argc, char **argv)
         if (method == NULL) method = conf->method;
         if (timeout == NULL) timeout = conf->timeout;
         if (fast_open == 0) fast_open = conf->fast_open;
+#ifdef HAVE_SETRLIMIT
+        if (nofile == 0) nofile = conf->nofile;
+        /*
+         * no need to check the return value here since we will show
+         * the user an error message if setrlimit(2) fails
+         */
+        if (nofile)
+        {
+            if (verbose)
+            {
+                LOGD("setting NOFILE to %d", nofile);
+            }
+            set_nofile(nofile);
+        }
+#endif
     }
 
     if (remote_num == 0 || remote_port == NULL ||

src/server.c

@@ -67,6 +67,9 @@ int udprelay = 0;
 #ifdef TCP_FASTOPEN
 static int fast_open = 0;
 #endif
+#ifdef HAVE_SETRLIMIT
+static int nofile = 0;
+#endif
 static int remote_conn = 0;
 static int server_conn = 0;
 
@@ -1048,6 +1051,21 @@ int main (int argc, char **argv)
         if (timeout == NULL) timeout = conf->timeout;
 #ifdef TCP_FASTOPEN
         if (fast_open == 0) fast_open = conf->fast_open;
+#endif
+#ifdef HAVE_SETRLIMIT
+        if (nofile == 0) nofile = conf->nofile;
+        /*
+         * no need to check the return value here since we will show
+         * the user an error message if setrlimit(2) fails
+         */
+        if (nofile)
+        {
+            if (verbose)
+            {
+                LOGD("setting NOFILE to %d", nofile);
+            }
+            set_nofile(nofile);
+        }
 #endif
     }
 

src/utils.c

@@ -37,6 +37,11 @@
 #include "config.h"
 #endif
 
+#ifdef HAVE_SETRLIMIT
+#include <sys/time.h>
+#include <sys/resource.h>
+#endif
+
 #define INT_DIGITS 19		/* enough for 64 bit integer */
 
 #ifdef HAS_SYSLOG
@@ -275,3 +280,36 @@ void daemonize(const char* path)
 #endif
 }
 
+#ifdef HAVE_SETRLIMIT
+int set_nofile(int nofile)
+{
+    struct rlimit limit = {nofile, nofile}; /* set both soft and hard limit */
+
+    if (nofile <= 0)
+    {
+        FATAL("nofile must be greater than 0\n");
+    }
+
+    if (setrlimit(RLIMIT_NOFILE, &limit) < 0)
+    {
+        if (errno == EPERM)
+        {
+            LOGE("insufficient permission to change NOFILE, not starting as root?");
+            return -1;
+        }
+        else if (errno == EINVAL)
+        {
+            LOGE("invalid fileno, decrease nofile and try again");
+            return -1;
+        }
+        else
+        {
+            LOGE("setrlimit failed: %s", strerror(errno));
+            return -1;
+        }
+    }
+
+    return 0;
+}
+#endif
+

src/utils.h

@@ -124,5 +124,8 @@ void FATAL(const char *msg);
 void usage(void);
 void daemonize(const char* path);
 char *ss_strndup(const char *s, size_t n);
+#ifdef HAVE_SETRLIMIT
+int set_nofile(int nofile);
+#endif
 
 #endif // _UTILS_H