linux-user: add a function hook to translate sockaddr

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

linux-user/syscall.c

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 25b846b..3484132 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -296,9 +296,11 @@
 };
 
 typedef abi_long (*TargetFdDataFunc)(void *, size_t);
+typedef abi_long (*TargetFdAddrFunc)(void *, abi_ulong, socklen_t);
 typedef struct TargetFdTrans {
     TargetFdDataFunc host_to_target_data;
     TargetFdDataFunc target_to_host_data;
+    TargetFdAddrFunc target_to_host_addr;
 } TargetFdTrans;
 
 static TargetFdTrans **target_fd_trans;
@@ -313,6 +315,14 @@
     return NULL;
 }
 
+static TargetFdAddrFunc fd_trans_target_to_host_addr(int fd)
+{
+    if (fd < target_fd_max && target_fd_trans[fd]) {
+        return target_fd_trans[fd]->target_to_host_addr;
+    }
+    return NULL;
+}
+
 static void fd_trans_register(int fd, TargetFdTrans *trans)
 {
     unsigned int oldmax;
@@ -1162,7 +1172,7 @@
     return 0;
 }
 
-static inline abi_long target_to_host_sockaddr(struct sockaddr *addr,
+static inline abi_long target_to_host_sockaddr(int fd, struct sockaddr *addr,
                                                abi_ulong target_addr,
                                                socklen_t len)
 {
@@ -1170,6 +1180,10 @@
     sa_family_t sa_family;
     struct target_sockaddr *target_saddr;
 
+    if (fd_trans_target_to_host_addr(fd)) {
+        return fd_trans_target_to_host_addr(fd)(addr, target_addr, len);
+    }
+
     target_saddr = lock_user(VERIFY_READ, target_addr, len, 1);
     if (!target_saddr)
         return -TARGET_EFAULT;
@@ -2115,7 +2129,7 @@
 
     addr = alloca(addrlen+1);
 
-    ret = target_to_host_sockaddr(addr, target_addr, addrlen);
+    ret = target_to_host_sockaddr(sockfd, addr, target_addr, addrlen);
     if (ret)
         return ret;
 
@@ -2135,7 +2149,7 @@
 
     addr = alloca(addrlen+1);
 
-    ret = target_to_host_sockaddr(addr, target_addr, addrlen);
+    ret = target_to_host_sockaddr(sockfd, addr, target_addr, addrlen);
     if (ret)
         return ret;
 
@@ -2155,8 +2169,9 @@
     if (msgp->msg_name) {
         msg.msg_namelen = tswap32(msgp->msg_namelen);
         msg.msg_name = alloca(msg.msg_namelen+1);
-        ret = target_to_host_sockaddr(msg.msg_name, tswapal(msgp->msg_name),
-                                msg.msg_namelen);
+        ret = target_to_host_sockaddr(fd, msg.msg_name,
+                                      tswapal(msgp->msg_name),
+                                      msg.msg_namelen);
         if (ret) {
             goto out2;
         }
@@ -2418,7 +2433,7 @@
         return -TARGET_EFAULT;
     if (target_addr) {
         addr = alloca(addrlen+1);
-        ret = target_to_host_sockaddr(addr, target_addr, addrlen);
+        ret = target_to_host_sockaddr(fd, addr, target_addr, addrlen);
         if (ret) {
             unlock_user(host_msg, msg, 0);
             return ret;