Avoid using DNS lookup for base server if possible.

The config can specify a hardcoded IP address now. This means glibc doesn't have to load an extra shared library, reducing memory footprint by 192 kilobytes.
icculus · Oct 12, 2008 · b535423 · b535423
1 parent caed808
commit b535423
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Showing 2 changed files with 14 additions and 3 deletions.
diff --git a/nph-offload.c b/nph-offload.c
@@ -95,6 +95,7 @@
  *    -DGDEBUGDIR='"/home/icculus/offload2.icculus.org/logs"' \
  *    -DSHM_NAME='"mod-offload-offload2-icculus-org"' \
  *    -DGBASESERVER='"icculus.org"' \
+ *    -DGBASESERVERIP='"67.106.77.212"' \
  *    -DGLISTENPORT=9090 \
  *    -DGLISTENDAEMONIZE=1 \
  *    -DGLISTENTRUSTFWD='"127.0.0.1", "66.33.209.154"' \
@@ -125,7 +126,7 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 
-#define GVERSION "1.1.5"
+#define GVERSION "1.1.6"
 #define GSERVERSTRING "nph-offload.c/" GVERSION
 
 #include "offload_server_config.h"
@@ -1061,7 +1062,7 @@ static int doHttp(const char *method, list **headers)
     hints.ai_flags = AI_NUMERICSERV | AI_V4MAPPED | AI_ALL | AI_ADDRCONFIG;
 
     struct addrinfo *dns = NULL;
-    if ((rc = getaddrinfo(GBASESERVER, GBASESERVERPORTSTR, &hints, &dns)) != 0)
+    if ((rc = getaddrinfo(GBASESERVERIP, GBASESERVERPORTSTR, &hints, &dns)) != 0)
     {
         debugEcho("getaddrinfo failure: %s", gai_strerror(rc));
         failure("503 Service Unavailable", "Offload base server hostname lookup failure.");

diff --git a/offload_server_config.h b/offload_server_config.h
@@ -69,11 +69,21 @@
 #define GLOGFILE "/usr/local/apache/logs/access.log"
 #endif
 
-// This is a list of servers that you are offloading.
+// This is the server that you are offloading's hostname.
 #ifndef GBASESERVER
 #define GBASESERVER "example.com"
 #endif
 
+// This is the server that you are offloading's IP address.
+//  We use this for DNS lookups (GBASESERVER is used for the "Host:" field in 
+//  HTTP requests, etc). If you know the IP address will never change, you can
+//  save the several hundred kilobytes of address space that glibc uses...it
+//  loads a separate shared library for the DNS lookup, but it doesn't need 
+//  to if GBASESERVERIP is an IP address in "xxx.xxx.xxx.xxx" format.
+#ifndef GBASESERVERIP
+#define GBASESERVERIP GBASESERVER
+#endif
+
 // This is the port on the base server to connect to (default for HTTP is 80).
 #ifndef GBASESERVERPORT
 #define GBASESERVERPORT 80