Define sockaddr_storage in bionic

Bionic currently renames the kernel's __kernel_sockaddr_storage
to sockaddr_storage.  We would like to reuse the bionic kernel
headers for musl, but musl defines its own sockaddr_storage,
causing redefinition errors when the musl and kernel headers
are both included.

Give bionic its own definition of sockaddr_storage so the kernel
one can be left as __kernel_sockaddr_storage, avoiding the
conflict in musl.

Some of the structs in netinet/in.h contain sockaddr_storage members.
There are definitions in linux/in.h, but they now use the
__kernel_sockaddr_storage naming.  To avoid having to copy the structs
from linux/in.h into netinet/in.h, add some #define hackery to
rename __kernel_sockaddr_storage to sockaddr_storage when including
linux/in.h from netinet/in.h.

Bug: 190084016
Test: m checkbuild
Test: bionic-unit-tests
Change-Id: I8f654511722b3a4a8e0bb146e4418ebcd370305c

libc/include/netinet/in.h

@@ -33,7 +33,18 @@
 #include <sys/cdefs.h>
 #include <sys/socket.h>
 
+// Include linux/socket.h first to trigger the header guard without
+// the__kernel_sockaddr_storage define, so its definition uses the
+// kernel name.
+#include <linux/socket.h>
+
+// Redefine __kernel_sockaddr_storage to sockaddr_storage so that
+// the structs defined in linux/in.h use the sockaddr_storage defined
+// in sys/sockets.h.
+#define __kernel_sockaddr_storage sockaddr_storage
 #include <linux/in.h>
+#undef __kernel_sockaddr_storage
+
 #include <linux/in6.h>
 #include <linux/ipv6.h>
 

libc/include/sys/socket.h

@@ -31,7 +31,6 @@
 
 #include <sys/cdefs.h>
 #include <sys/types.h>
-#include <linux/socket.h>
 
 #include <asm/fcntl.h>
 #include <asm/socket.h>
@@ -71,6 +70,16 @@ struct sockaddr {
   char sa_data[14];
 };
 
+struct sockaddr_storage {
+  union {
+    struct {
+      sa_family_t ss_family;
+      char __data[128 - sizeof(sa_family_t)];
+    };
+    void* __align;
+  };
+};
+
 struct linger {
   int l_onoff;
   int l_linger;

libc/kernel/tools/defaults.py

@@ -89,8 +89,6 @@ kernel_token_replacements = {
     "udphdr": "__kernel_udphdr",
     # This causes problems when trying to export the headers for the ndk.
     "__attribute_const__": "__attribute__((__const__))",
-    # In this case the kernel tries to keep out of our way, but we're happy to use its definition.
-    "__kernel_sockaddr_storage": "sockaddr_storage",
     # The kernel started using struct __kernel_old_timeval in some places,
     # which is the exact same as struct timeval. Replace that name with
     # timeval so that kernel structures all use the same named structure.

libc/kernel/uapi/linux/in.h

@@ -155,21 +155,21 @@ struct ip_mreqn {
 #define IP_MSFILTER_SIZE(numsrc) (sizeof(struct ip_msfilter) - sizeof(__u32) + (numsrc) * sizeof(__u32))
 struct group_req {
   __u32 gr_interface;
-  struct sockaddr_storage gr_group;
+  struct __kernel_sockaddr_storage gr_group;
 };
 struct group_source_req {
   __u32 gsr_interface;
-  struct sockaddr_storage gsr_group;
-  struct sockaddr_storage gsr_source;
+  struct __kernel_sockaddr_storage gsr_group;
+  struct __kernel_sockaddr_storage gsr_source;
 };
 struct group_filter {
   __u32 gf_interface;
-  struct sockaddr_storage gf_group;
+  struct __kernel_sockaddr_storage gf_group;
   __u32 gf_fmode;
   __u32 gf_numsrc;
-  struct sockaddr_storage gf_slist[1];
+  struct __kernel_sockaddr_storage gf_slist[1];
 };
-#define GROUP_FILTER_SIZE(numsrc) (sizeof(struct group_filter) - sizeof(struct sockaddr_storage) + (numsrc) * sizeof(struct sockaddr_storage))
+#define GROUP_FILTER_SIZE(numsrc) (sizeof(struct group_filter) - sizeof(struct __kernel_sockaddr_storage) + (numsrc) * sizeof(struct __kernel_sockaddr_storage))
 #endif
 #if __UAPI_DEF_IN_PKTINFO
 struct in_pktinfo {

libc/kernel/uapi/linux/rds.h

@@ -217,7 +217,7 @@ struct rds_get_mr_args {
   __u64 flags;
 };
 struct rds_get_mr_for_dest_args {
-  struct sockaddr_storage dest_addr;
+  struct __kernel_sockaddr_storage dest_addr;
   struct rds_iovec vec;
   __u64 cookie_addr;
   __u64 flags;

libc/kernel/uapi/linux/socket.h

@@ -20,7 +20,7 @@
 #define _UAPI_LINUX_SOCKET_H
 #define _K_SS_MAXSIZE 128
 typedef unsigned short __kernel_sa_family_t;
-struct sockaddr_storage {
+struct __kernel_sockaddr_storage {
   union {
     struct {
       __kernel_sa_family_t ss_family;

libc/kernel/uapi/linux/tcp.h

@@ -226,7 +226,7 @@ enum {
 #define TCP_MD5SIG_FLAG_PREFIX 0x1
 #define TCP_MD5SIG_FLAG_IFINDEX 0x2
 struct tcp_md5sig {
-  struct sockaddr_storage tcpm_addr;
+  struct __kernel_sockaddr_storage tcpm_addr;
   __u8 tcpm_flags;
   __u8 tcpm_prefixlen;
   __u16 tcpm_keylen;

libc/kernel/uapi/rdma/rdma_user_cm.h

@@ -88,7 +88,7 @@ struct rdma_ucm_bind {
   __u32 id;
   __u16 addr_size;
   __u16 reserved;
-  struct sockaddr_storage addr;
+  struct __kernel_sockaddr_storage addr;
 };
 struct rdma_ucm_resolve_ip {
   struct sockaddr_in6 src_addr;
@@ -102,8 +102,8 @@ struct rdma_ucm_resolve_addr {
   __u16 src_size;
   __u16 dst_size;
   __u32 reserved;
-  struct sockaddr_storage src_addr;
-  struct sockaddr_storage dst_addr;
+  struct __kernel_sockaddr_storage src_addr;
+  struct __kernel_sockaddr_storage dst_addr;
 };
 struct rdma_ucm_resolve_route {
   __u32 id;
@@ -137,8 +137,8 @@ struct rdma_ucm_query_addr_resp {
   __u16 pkey;
   __u16 src_size;
   __u16 dst_size;
-  struct sockaddr_storage src_addr;
-  struct sockaddr_storage dst_addr;
+  struct __kernel_sockaddr_storage src_addr;
+  struct __kernel_sockaddr_storage dst_addr;
   __u32 ibdev_index;
   __u32 reserved1;
 };
@@ -225,7 +225,7 @@ struct rdma_ucm_join_mcast {
   __u32 id;
   __u16 addr_size;
   __u16 join_flags;
-  struct sockaddr_storage addr;
+  struct __kernel_sockaddr_storage addr;
 };
 struct rdma_ucm_get_event {
   __aligned_u64 response;