commit d469482cda460107c034f8d9e723de830a1f768e
author Ruslan Ermilov <ru@nginx.com> Thu Aug 30 14:58:11 2012 +0000
committer Ruslan Ermilov <ru@nginx.com> Thu Aug 30 14:58:11 2012 +0000
tree 5ab93300c30e9f5f37ee136831f5bc961cca848c
parent da4ffd8955b14383d6c027004d8beb85395ce9f5

Fixed strict aliasing bugs when dealing with IPv4-mapped IPv6 addresses
(closes #201).

src/http/modules/ngx_http_geo_module.c

diff --git a/src/http/modules/ngx_http_geo_module.c b/src/http/modules/ngx_http_geo_module.c
index 2308162..fce87a8 100644
--- a/src/http/modules/ngx_http_geo_module.c
+++ b/src/http/modules/ngx_http_geo_module.c
@@ -233,12 +233,21 @@
 #if (NGX_HAVE_INET6)
 
     if (addr.sockaddr->sa_family == AF_INET6) {
+        u_char           *p;
+        in_addr_t         inaddr;
         struct in6_addr  *inaddr6;
 
         inaddr6 = &((struct sockaddr_in6 *) addr.sockaddr)->sin6_addr;
 
         if (IN6_IS_ADDR_V4MAPPED(inaddr6)) {
-            return ntohl(*(in_addr_t *) &inaddr6->s6_addr[12]);
+            p = inaddr6->s6_addr;
+
+            inaddr = p[12] << 24;
+            inaddr += p[13] << 16;
+            inaddr += p[14] << 8;
+            inaddr += p[15];
+
+            return inaddr;
         }
     }
 

src/http/modules/ngx_http_geoip_module.c

diff --git a/src/http/modules/ngx_http_geoip_module.c b/src/http/modules/ngx_http_geoip_module.c
index 0ce3bf1..7ff4f10 100644
--- a/src/http/modules/ngx_http_geoip_module.c
+++ b/src/http/modules/ngx_http_geoip_module.c
@@ -226,12 +226,21 @@
 #if (NGX_HAVE_INET6)
 
     if (addr.sockaddr->sa_family == AF_INET6) {
+        u_char           *p;
+        in_addr_t         inaddr;
         struct in6_addr  *inaddr6;
 
         inaddr6 = &((struct sockaddr_in6 *) addr.sockaddr)->sin6_addr;
 
         if (IN6_IS_ADDR_V4MAPPED(inaddr6)) {
-            return ntohl(*(in_addr_t *) &inaddr6->s6_addr[12]);
+            p = inaddr6->s6_addr;
+
+            inaddr = p[12] << 24;
+            inaddr += p[13] << 16;
+            inaddr += p[14] << 8;
+            inaddr += p[15];
+
+            return inaddr;
         }
     }
 

src/http/ngx_http_core_module.c

diff --git a/src/http/ngx_http_core_module.c b/src/http/ngx_http_core_module.c
index 5ab9453..826e4e5 100644
--- a/src/http/ngx_http_core_module.c
+++ b/src/http/ngx_http_core_module.c
@@ -2776,7 +2776,15 @@
 
         if (IN6_IS_ADDR_V4MAPPED(inaddr6)) {
             family = AF_INET;
-            inaddr = *(in_addr_t *) &inaddr6->s6_addr[12];
+
+            p = inaddr6->s6_addr;
+
+            inaddr = p[12] << 24;
+            inaddr += p[13] << 16;
+            inaddr += p[14] << 8;
+            inaddr += p[15];
+
+            inaddr = htonl(inaddr);
         }
     }
 #endif