bionic: Fix aliasing violations

This makes bionic compile with compilers enforcing
strict adherence to aliasing rules (e.g. gcc 4.6+
with -Wstrict-aliasing=2 -Werror=strict-aliasing).

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

7 files changed, 64 insertions, 44 deletions

diff --git a/libc/bionic/md5.c b/libc/bionic/md5.c
index ba4aaed22..02785bdaa 100644
--- a/libc/bionic/md5.c
+++ b/libc/bionic/md5.c
@@ -231,7 +231,7 @@ MD5_Update (struct md5 *m, const void *v, size_t len)
       }
       calc(m, current);
 #else
-      calc(m, (u_int32_t*)m->save);
+      calc(m, m->save32);
 #endif
       offset = 0;
     }
diff --git a/libc/bionic/md5.h b/libc/bionic/md5.h
index a381994ef..3b0a2511b 100644
--- a/libc/bionic/md5.h
+++ b/libc/bionic/md5.h
@@ -40,7 +40,10 @@
 struct md5 {
   unsigned int sz[2];
   u_int32_t counter[4];
-  unsigned char save[64];
+  union {
+    unsigned char save[64];
+    u_int32_t save32[16];
+  };
 };
 
 typedef struct md5 MD5_CTX;
diff --git a/libc/bionic/system_properties.c b/libc/bionic/system_properties.c
index 0587430a5..3fadba2cd 100644
--- a/libc/bionic/system_properties.c
+++ b/libc/bionic/system_properties.c
@@ -197,7 +197,10 @@ int __system_property_get(const char *name, char *value)
 static int send_prop_msg(prop_msg *msg)
 {
     struct pollfd pollfds[1];
-    struct sockaddr_un addr;
+    union {
+        struct sockaddr_un addr;
+        struct sockaddr addr_g;
+    } addr;
     socklen_t alen;
     size_t namelen;
     int s;
@@ -211,11 +214,11 @@ static int send_prop_msg(prop_msg *msg)
 
     memset(&addr, 0, sizeof(addr));
     namelen = strlen(property_service_socket);
-    strlcpy(addr.sun_path, property_service_socket, sizeof addr.sun_path);
-    addr.sun_family = AF_LOCAL;
+    strlcpy(addr.addr.sun_path, property_service_socket, sizeof addr.addr.sun_path);
+    addr.addr.sun_family = AF_LOCAL;
     alen = namelen + offsetof(struct sockaddr_un, sun_path) + 1;
 
-    if(TEMP_FAILURE_RETRY(connect(s, (struct sockaddr *) &addr, alen)) < 0) {
+    if(TEMP_FAILURE_RETRY(connect(s, &addr.addr_g, alen) < 0)) {
         close(s);
         return result;
     }
diff --git a/libc/include/netinet/in6.h b/libc/include/netinet/in6.h
index 7f3286ae9..c8ba133de 100644
--- a/libc/include/netinet/in6.h
+++ b/libc/include/netinet/in6.h
@@ -31,28 +31,28 @@
 #include <linux/in6.h>
 
 #define IN6_IS_ADDR_UNSPECIFIED(a)	\
-	((*(const uint32_t *)(const void *)(&(a)->s6_addr[0]) == 0) &&	\
-	 (*(const uint32_t *)(const void *)(&(a)->s6_addr[4]) == 0) &&	\
-	 (*(const uint32_t *)(const void *)(&(a)->s6_addr[8]) == 0) &&	\
-	 (*(const uint32_t *)(const void *)(&(a)->s6_addr[12]) == 0))
+	(((a)->s6_addr32[0] == 0) &&    \
+         ((a)->s6_addr32[1] == 0) &&    \
+         ((a)->s6_addr32[2] == 0) &&    \
+         ((a)->s6_addr32[3] == 0))
 
 #define IN6_IS_ADDR_LOOPBACK(a)		\
-	((*(const uint32_t *)(const void *)(&(a)->s6_addr[0]) == 0) &&	\
-	 (*(const uint32_t *)(const void *)(&(a)->s6_addr[4]) == 0) &&	\
-	 (*(const uint32_t *)(const void *)(&(a)->s6_addr[8]) == 0) &&	\
-	 (*(const uint32_t *)(const void *)(&(a)->s6_addr[12]) == ntohl(1)))
+	(((a)->s6_addr32[0] == 0) &&    \
+         ((a)->s6_addr32[1] == 0) &&    \
+         ((a)->s6_addr32[2] == 0) &&    \
+         ((a)->s6_addr32[3] == ntohl(1)))
 
 #define IN6_IS_ADDR_V4COMPAT(a)		\
-	((*(const uint32_t *)(const void *)(&(a)->s6_addr[0]) == 0) &&	\
-	 (*(const uint32_t *)(const void *)(&(a)->s6_addr[4]) == 0) &&	\
-	 (*(const uint32_t *)(const void *)(&(a)->s6_addr[8]) == 0) &&	\
-	 (*(const uint32_t *)(const void *)(&(a)->s6_addr[12]) != 0) &&	\
-	 (*(const uint32_t *)(const void *)(&(a)->s6_addr[12]) != ntohl(1)))
+	(((a)->s6_addr32[0] == 0) &&    \
+         ((a)->s6_addr32[1] == 0) &&    \
+         ((a)->s6_addr32[2] == 0) &&    \
+         ((a)->s6_addr32[3] != 0) &&    \
+         ((a)->s6_addr32[3] != ntohl(1)))
 
 #define IN6_IS_ADDR_V4MAPPED(a)		      \
-	((*(const uint32_t *)(const void *)(&(a)->s6_addr[0]) == 0) &&	\
-	 (*(const uint32_t *)(const void *)(&(a)->s6_addr[4]) == 0) &&	\
-	 (*(const uint32_t *)(const void *)(&(a)->s6_addr[8]) == ntohl(0x0000ffff)))
+	(((a)->s6_addr32[0] == 0) &&    \
+         ((a)->s6_addr32[1] == 0) &&    \
+         ((a)->s6_addr32[2] == ntohl(0x0000ffff)))
 
 #define IN6_IS_ADDR_LINKLOCAL(a)	\
 	(((a)->s6_addr[0] == 0xfe) && (((a)->s6_addr[1] & 0xc0) == 0x80))
@@ -65,7 +65,7 @@
 	(((a)->s6_addr[0] & 0xfe) == 0xfc)
 
 #define IN6_IS_ADDR_MULTICAST(a)	\
-	(((__const uint8_t *) (a))[0] == 0xff)
+	((a)->s6_addr[0] == 0xff)
 
 
 #define IPV6_ADDR_SCOPE_NODELOCAL       0x01
diff --git a/libc/netbsd/gethnamaddr.c b/libc/netbsd/gethnamaddr.c
index ee5052e4c..62144675e 100644
--- a/libc/netbsd/gethnamaddr.c
+++ b/libc/netbsd/gethnamaddr.c
@@ -824,14 +824,14 @@ android_gethostbyaddrforiface_real(const void *addr,
 	assert(addr != NULL);
 
 	if (af == AF_INET6 && len == IN6ADDRSZ &&
-	    (IN6_IS_ADDR_LINKLOCAL((const struct in6_addr *)(const void *)uaddr) ||
-	     IN6_IS_ADDR_SITELOCAL((const struct in6_addr *)(const void *)uaddr))) {
+	    (IN6_IS_ADDR_LINKLOCAL((const struct in6_addr *)addr) ||
+	     IN6_IS_ADDR_SITELOCAL((const struct in6_addr *)addr))) {
 		h_errno = HOST_NOT_FOUND;
 		return NULL;
 	}
 	if (af == AF_INET6 && len == IN6ADDRSZ &&
-	    (IN6_IS_ADDR_V4MAPPED((const struct in6_addr *)(const void *)uaddr) ||
-	     IN6_IS_ADDR_V4COMPAT((const struct in6_addr *)(const void *)uaddr))) {
+	    (IN6_IS_ADDR_V4MAPPED((const struct in6_addr *)addr) ||
+	     IN6_IS_ADDR_V4COMPAT((const struct in6_addr *)addr))) {
 		/* Unmap. */
 		addr += IN6ADDRSZ - INADDRSZ;
 		uaddr += IN6ADDRSZ - INADDRSZ;
diff --git a/libc/netbsd/net/getaddrinfo.c b/libc/netbsd/net/getaddrinfo.c
index 401bc6efc..9d8314b8c 100644
--- a/libc/netbsd/net/getaddrinfo.c
+++ b/libc/netbsd/net/getaddrinfo.c
@@ -410,7 +410,10 @@ android_getaddrinfo_proxy(
 {
 	int sock;
 	const int one = 1;
-	struct sockaddr_un proxy_addr;
+	union {
+	        struct sockaddr_un un;
+	        struct sockaddr generic;
+	} proxy_addr;
 	FILE* proxy = NULL;
 	int success = 0;
 
@@ -434,12 +437,12 @@ android_getaddrinfo_proxy(
 
 	setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
 	memset(&proxy_addr, 0, sizeof(proxy_addr));
-	proxy_addr.sun_family = AF_UNIX;
-	strlcpy(proxy_addr.sun_path, "/dev/socket/dnsproxyd",
-		sizeof(proxy_addr.sun_path));
+	proxy_addr.un.sun_family = AF_UNIX;
+	strlcpy(proxy_addr.un.sun_path, "/dev/socket/dnsproxyd",
+		sizeof(proxy_addr.un.sun_path));
 	if (TEMP_FAILURE_RETRY(connect(sock,
-				       (const struct sockaddr*) &proxy_addr,
-				       sizeof(proxy_addr))) != 0) {
+				       &proxy_addr.generic,
+				       sizeof(proxy_addr.un))) != 0) {
 		close(sock);
 		return EAI_NODATA;
 	}
@@ -1536,7 +1539,7 @@ _get_scope(const struct sockaddr *addr)
 
 /* RFC 4380, section 2.6 */
 #define IN6_IS_ADDR_TEREDO(a)	 \
-	((*(const uint32_t *)(const void *)(&(a)->s6_addr[0]) == ntohl(0x20010000)))
+	(((a)->s6_addr32[0]) == ntohl(0x20010000))
 
 /* RFC 3056, section 2. */
 #define IN6_IS_ADDR_6TO4(a)	 \
diff --git a/libc/netbsd/resolv/res_send.c b/libc/netbsd/resolv/res_send.c
index d407ac8c8..0293af6cf 100644
--- a/libc/netbsd/resolv/res_send.c
+++ b/libc/netbsd/resolv/res_send.c
@@ -418,6 +418,10 @@ res_nsend(res_state statp,
 	if (EXT(statp).nscount != 0) {
 		int needclose = 0;
 		struct sockaddr_storage peer;
+		union {
+			struct sockaddr_storage storage;
+			struct sockaddr generic;
+		} peer;
 		socklen_t peerlen;
 
 		if (EXT(statp).nscount != statp->nscount)
@@ -433,13 +437,13 @@ res_nsend(res_state statp,
 
 				if (EXT(statp).nssocks[ns] == -1)
 					continue;
-				peerlen = sizeof(peer);
+				peerlen = sizeof(peer.storage);
 				if (getpeername(EXT(statp).nssocks[ns],
-				    (struct sockaddr *)(void *)&peer, &peerlen) < 0) {
+				    &peer.generic, &peerlen) < 0) {
 					needclose++;
 					break;
 				}
-				if (!sock_eq((struct sockaddr *)(void *)&peer,
+				if (!sock_eq(&peer.generic,
 				    get_nsaddr(statp, (size_t)ns))) {
 					needclose++;
 					break;
@@ -760,12 +764,15 @@ send_vc(res_state statp,
 
 	/* Are we still talking to whom we want to talk to? */
 	if (statp->_vcsock >= 0 && (statp->_flags & RES_F_VC) != 0) {
-		struct sockaddr_storage peer;
-		socklen_t size = sizeof peer;
+		union {
+			struct sockaddr_storage storage;
+			struct sockaddr generic;
+		} peer;
+		socklen_t size = sizeof peer.storage;
 
 		if (getpeername(statp->_vcsock,
-				(struct sockaddr *)(void *)&peer, &size) < 0 ||
-		    !sock_eq((struct sockaddr *)(void *)&peer, nsap)) {
+				&peer.generic, &size) < 0 ||
+		    !sock_eq(&peer.generic, nsap)) {
 			res_nclose(statp);
 			statp->_flags &= ~RES_F_VC;
 		}
@@ -1044,6 +1051,10 @@ send_dg(res_state statp,
 	struct timespec now, timeout, finish;
 	fd_set dsmask;
 	struct sockaddr_storage from;
+	union {
+		struct sockaddr_storage storage;
+		struct sockaddr generic;
+	} from;
 	socklen_t fromlen;
 	int resplen, seconds, n, s;
 
@@ -1135,9 +1146,9 @@ retry:
 		return (0);
 	}
 	errno = 0;
-	fromlen = sizeof(from);
+	fromlen = sizeof(from.storage);
 	resplen = recvfrom(s, (char*)ans, (size_t)anssiz,0,
-			   (struct sockaddr *)(void *)&from, &fromlen);
+			   &from.generic, &fromlen);
 	if (resplen <= 0) {
 		Perror(statp, stderr, "recvfrom", errno);
 		res_nclose(statp);
@@ -1171,7 +1182,7 @@ retry:
 		goto retry;
 	}
 	if (!(statp->options & RES_INSECURE1) &&
-	    !res_ourserver_p(statp, (struct sockaddr *)(void *)&from)) {
+	    !res_ourserver_p(statp, &from.generic)) {
 		/*
 		 * response from wrong server? ignore it.
 		 * XXX - potential security hazard could