Fix the dns bug: children weren't dying

We were telling a child to die by closing the parent's file descriptor
to him. But newer children were inheriting the open file descriptor from
the parent, and since they weren't closing them, the socket never closed,
so the child never read eof, so he never knew to exit.

As a side effect to this bug, we were probably failing to properly close
connections to remote hosts, ORs, and OPs, after a dns child was born.

I'm surprised Tor worked at all.


svn:r974

4 files changed, 13 insertions, 1 deletions

diff --git a/src/or/connection.c b/src/or/connection.c
index 5299e8965..03134d335 100644
--- a/src/or/connection.c
+++ b/src/or/connection.c
@@ -128,6 +128,15 @@ void connection_free(connection_t *conn) {
   free(conn);
 }
 
+void connection_free_all(void) {
+  int i, n;
+  connection_t **carray;
+
+  get_connection_array(&carray,&n);
+  for(i=0;i<n;i++)
+    connection_free(carray[i]);
+}
+
 int connection_create_listener(char *bindaddress, uint16_t bindport, int type) {
   struct sockaddr_in bindaddr; /* where to bind */
   struct hostent *rent;
diff --git a/src/or/cpuworker.c b/src/or/cpuworker.c
index 40a5e6f39..51c582c1c 100644
--- a/src/or/cpuworker.c
+++ b/src/or/cpuworker.c
@@ -126,6 +126,7 @@ int cpuworker_main(void *data) {
 
   close(fdarray[0]); /* this is the side of the socketpair the parent uses */
   fd = fdarray[1]; /* this side is ours */
+  connection_free_all(); /* so the child doesn't hold the parent's fd's open */
 
   for(;;) {
 
diff --git a/src/or/dns.c b/src/or/dns.c
index 0cf437afe..88607172d 100644
--- a/src/or/dns.c
+++ b/src/or/dns.c
@@ -395,6 +395,7 @@ int dnsworker_main(void *data) {
 
   close(fdarray[0]); /* this is the side of the socketpair the parent uses */
   fd = fdarray[1]; /* this side is ours */
+  connection_free_all(); /* so the child doesn't hold the parent's fd's open */
 
   for(;;) {
 
@@ -506,7 +507,7 @@ static void spawn_enough_dnsworkers(void) {
     num_dnsworkers++;
   }
 
-  while(num_dnsworkers > num_dnsworkers_needed+MAX_IDLE_DNSWORKERS) { /* too many idle? */
+  while(num_dnsworkers > num_dnsworkers_busy+MAX_IDLE_DNSWORKERS) { /* too many idle? */
     /* cull excess workers */
     log_fn(LOG_WARN,"%d of %d dnsworkers are idle. Killing one.",
            num_dnsworkers-num_dnsworkers_needed, num_dnsworkers);
diff --git a/src/or/or.h b/src/or/or.h
index 76d2afeb5..b7e323b3d 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -615,6 +615,7 @@ int getconfig(int argc, char **argv, or_options_t *options);
 
 connection_t *connection_new(int type);
 void connection_free(connection_t *conn);
+void connection_free_all(void);
 
 int connection_create_listener(char *bindaddress, uint16_t bindport, int type);