Use the canonical idiom for sockaddr_storage.

This works out a bit silly/ugly because the bits/ header file has the
wrong name, so I've also changed the map from kernel struct to boolean
to be a map from kernel struct to filename. That not only fixes this,
it's a bit more readable too. (Just yesterday, when I had no real reason
to change it, I was asking myself "why is this a boolean?"!)

Bug: http://b/236042740
Test: treehugger
Change-Id: I3eee25b493ea97d46cc5dc5fde07f7c5e77d2a46
diff --git a/libc/kernel/uapi/linux/in.h b/libc/kernel/uapi/linux/in.h
index e784690..44efdd8 100644
--- a/libc/kernel/uapi/linux/in.h
+++ b/libc/kernel/uapi/linux/in.h
@@ -148,32 +148,32 @@
 #define IP_MSFILTER_SIZE(numsrc) (sizeof(struct ip_msfilter) - sizeof(__u32) + (numsrc) * sizeof(__u32))
 struct group_req {
   __u32 gr_interface;
-  struct __kernel_sockaddr_storage gr_group;
+  struct sockaddr_storage gr_group;
 };
 struct group_source_req {
   __u32 gsr_interface;
-  struct __kernel_sockaddr_storage gsr_group;
-  struct __kernel_sockaddr_storage gsr_source;
+  struct sockaddr_storage gsr_group;
+  struct sockaddr_storage gsr_source;
 };
 struct group_filter {
   union {
     struct {
       __u32 gf_interface_aux;
-      struct __kernel_sockaddr_storage gf_group_aux;
+      struct sockaddr_storage gf_group_aux;
       __u32 gf_fmode_aux;
       __u32 gf_numsrc_aux;
-      struct __kernel_sockaddr_storage gf_slist[1];
+      struct sockaddr_storage gf_slist[1];
     };
     struct {
       __u32 gf_interface;
-      struct __kernel_sockaddr_storage gf_group;
+      struct sockaddr_storage gf_group;
       __u32 gf_fmode;
       __u32 gf_numsrc;
-      struct __kernel_sockaddr_storage gf_slist_flex[];
+      struct sockaddr_storage gf_slist_flex[];
     };
   };
 };
-#define GROUP_FILTER_SIZE(numsrc) (sizeof(struct group_filter) - sizeof(struct __kernel_sockaddr_storage) + (numsrc) * sizeof(struct __kernel_sockaddr_storage))
+#define GROUP_FILTER_SIZE(numsrc) (sizeof(struct group_filter) - sizeof(struct sockaddr_storage) + (numsrc) * sizeof(struct sockaddr_storage))
 #endif
 #if __UAPI_DEF_IN_PKTINFO
 struct in_pktinfo {
diff --git a/libc/kernel/uapi/linux/mptcp.h b/libc/kernel/uapi/linux/mptcp.h
index f00abae..d97f29b 100644
--- a/libc/kernel/uapi/linux/mptcp.h
+++ b/libc/kernel/uapi/linux/mptcp.h
@@ -163,13 +163,13 @@
     struct sockaddr sa_local;
     struct sockaddr_in sin_local;
     struct sockaddr_in6 sin6_local;
-    struct __kernel_sockaddr_storage ss_local;
+    struct sockaddr_storage ss_local;
   };
   union {
     struct sockaddr sa_remote;
     struct sockaddr_in sin_remote;
     struct sockaddr_in6 sin6_remote;
-    struct __kernel_sockaddr_storage ss_remote;
+    struct sockaddr_storage ss_remote;
   };
 };
 struct mptcp_subflow_info {
diff --git a/libc/kernel/uapi/linux/rds.h b/libc/kernel/uapi/linux/rds.h
index bc41946..e2a7a38 100644
--- a/libc/kernel/uapi/linux/rds.h
+++ b/libc/kernel/uapi/linux/rds.h
@@ -205,7 +205,7 @@
   __u64 flags;
 };
 struct rds_get_mr_for_dest_args {
-  struct __kernel_sockaddr_storage dest_addr;
+  struct sockaddr_storage dest_addr;
   struct rds_iovec vec;
   __u64 cookie_addr;
   __u64 flags;
diff --git a/libc/kernel/uapi/linux/socket.h b/libc/kernel/uapi/linux/socket.h
index 936f44a..27890a4 100644
--- a/libc/kernel/uapi/linux/socket.h
+++ b/libc/kernel/uapi/linux/socket.h
@@ -6,17 +6,9 @@
  */
 #ifndef _UAPI_LINUX_SOCKET_H
 #define _UAPI_LINUX_SOCKET_H
+#include <bits/sockaddr_storage.h>
 #define _K_SS_MAXSIZE 128
 typedef unsigned short __kernel_sa_family_t;
-struct __kernel_sockaddr_storage {
-  union {
-    struct {
-      __kernel_sa_family_t ss_family;
-      char __data[_K_SS_MAXSIZE - sizeof(unsigned short)];
-    };
-    void * __align;
-  };
-};
 #define SOCK_SNDBUF_LOCK 1
 #define SOCK_RCVBUF_LOCK 2
 #define SOCK_BUF_LOCK_MASK (SOCK_SNDBUF_LOCK | SOCK_RCVBUF_LOCK)
diff --git a/libc/kernel/uapi/linux/tcp.h b/libc/kernel/uapi/linux/tcp.h
index 20fbcec..65bab54 100644
--- a/libc/kernel/uapi/linux/tcp.h
+++ b/libc/kernel/uapi/linux/tcp.h
@@ -202,7 +202,7 @@
 #define TCP_MD5SIG_FLAG_PREFIX 0x1
 #define TCP_MD5SIG_FLAG_IFINDEX 0x2
 struct tcp_md5sig {
-  struct __kernel_sockaddr_storage tcpm_addr;
+  struct sockaddr_storage tcpm_addr;
   __u8 tcpm_flags;
   __u8 tcpm_prefixlen;
   __u16 tcpm_keylen;