[or-cvs] Clean up the rlimit thing somewhat.

[arma@xxxxxxxx (Roger Dingledine)]

Update of /home2/or/cvsroot/tor/src/common
In directory moria.mit.edu:/home2/arma/work/onion/0091/tor/src/common

Modified Files:
      Tag: tor-0_0_9-patches
	compat.c compat.h 
Log Message:
Clean up the rlimit thing somewhat.
Now we cap it better, and survive hups better.
I changed the name MaxConn to ConnLimit, to indicate
that it's a lower bound, not an upper bound. Perhaps it
needs an even better name?


Index: compat.c
===================================================================
RCS file: /home2/or/cvsroot/tor/src/common/compat.c,v
retrieving revision 1.22.2.9
retrieving revision 1.22.2.10
diff -u -d -r1.22.2.9 -r1.22.2.10
--- compat.c	17 Feb 2005 04:58:30 -0000	1.22.2.9
+++ compat.c	19 Feb 2005 03:42:26 -0000	1.22.2.10
@@ -352,13 +352,14 @@
 #endif
 }
 
+#define ULIMIT_BUFFER 32 /* keep 32 extra fd's beyond _ConnLimit */
+
 /** Get the maximum allowed number of file descriptors. (Some systems
  * have a low soft limit.) Make sure we set it to at least
- * 1024. Return 0 if we can, or -1 if we fail. */
-int set_max_file_descriptors(int *maxconn) {
+ * <b>*limit</b>. Return a new limit if we can, or -1 if we fail. */
+int set_max_file_descriptors(int limit, int cap) {
 #ifndef HAVE_GETRLIMIT
   log_fn(LOG_INFO,"This platform is missing getrlimit(). Proceeding.");
-  return 0; /* hope we'll be ok */
 #else
   struct rlimit rlim;
   int most;
@@ -368,11 +369,11 @@
            strerror(errno));
     return -1;
   }
-  if (rlim.rlim_max < 1024) {
-    log_fn(LOG_WARN,"We need %u file descriptors available, and we're limited to %lu. Please change your ulimit -n.", 1024, (unsigned long int)rlim.rlim_max);
+  if (rlim.rlim_max < limit) {
+    log_fn(LOG_WARN,"We need %d file descriptors available, and we're limited to %lu. Please change your ulimit -n.", limit, (unsigned long int)rlim.rlim_max);
     return -1;
   }
-  most = ((rlim.rlim_max > INT_MAX) ? INT_MAX : rlim.rlim_max);
+  most = ((rlim.rlim_max > cap) ? cap : rlim.rlim_max);
   if (most > rlim.rlim_cur) {
     log_fn(LOG_INFO,"Raising max file descriptors from %lu to %d.",
            (unsigned long int)rlim.rlim_cur, most);
@@ -383,10 +384,26 @@
            strerror(errno));
     return -1;
   }
-  /* leave some overhead for logs, etc, and don't overflow INT_MAX */
-  *maxconn = most - 32;
-  return 0;
+  /* leave some overhead for logs, etc, */
+  limit = most;
 #endif
+
+#ifdef USE_FAKE_POLL
+  if (limit > 1024) {
+    log(LOG_INFO, "Systems without a working poll() can't set ConnLimit higher than %d in Tor 0.0.9.x. Capping.", 1024);
+    limit = 1024;
+  }
+#endif
+
+  if (limit > cap) { /* this won't be checked above if ndef getrlimit */
+    log(LOG_INFO, "ConnLimit must be at most %d. Capping it.", cap);
+    limit = cap;
+  }
+  if (limit < ULIMIT_BUFFER) {
+    log_fn(LOG_WARN,"ConnLimit must be at least %d. Failing.", ULIMIT_BUFFER);
+    return -1;
+  }
+  return limit - ULIMIT_BUFFER;
 }
 
 /** Call setuid and setgid to run as <b>user</b>:<b>group</b>.  Return 0 on

Index: compat.h
===================================================================
RCS file: /home2/or/cvsroot/tor/src/common/compat.h,v
retrieving revision 1.13.2.7
retrieving revision 1.13.2.8
diff -u -d -r1.13.2.7 -r1.13.2.8
--- compat.h	4 Feb 2005 07:16:10 -0000	1.13.2.7
+++ compat.h	19 Feb 2005 03:42:26 -0000	1.13.2.8
@@ -177,7 +177,7 @@
 void set_uint32(char *cp, uint32_t v);
 #endif
 
-int set_max_file_descriptors(int *maxconn);
+int set_max_file_descriptors(int limit, int cap);
 int switch_id(char *user, char *group);
 #ifdef HAVE_PWD_H
 char *get_user_homedir(const char *username);