socket-wrapped: added wrappers for dup() and dup2()

The Samba4 standard process model uses dup() on incoming sockets as an
optimisation (it makes select() a tiny bit faster when used).

Adding dup() to socket wrapper allows us to use the standard process
model in selftest

Pair-Programmed-With: Andrew Bartlett <abartlet@samba.org>

2 files changed, 131 insertions, 2 deletions

diff --git a/lib/socket_wrapper/socket_wrapper.c b/lib/socket_wrapper/socket_wrapper.c
index 2b526262bd..946980963e 100644
--- a/lib/socket_wrapper/socket_wrapper.c
+++ b/lib/socket_wrapper/socket_wrapper.c
@@ -127,6 +127,8 @@
 #define real_writev writev
 #define real_socket socket
 #define real_close close
+#define real_dup dup
+#define real_dup2 dup2
 #endif
 
 #ifdef HAVE_GETTIMEOFDAY_TZ
@@ -225,7 +227,6 @@ struct socket_info
 	int connected;
 	int defer_connect;
 
-	char *path;
 	char *tmp_path;
 
 	struct sockaddr *myname;
@@ -2523,7 +2524,6 @@ _PUBLIC_ int swrap_close(int fd)
 		swrap_dump_packet(si, NULL, SWRAP_CLOSE_ACK, NULL, 0);
 	}
 
-	if (si->path) free(si->path);
 	if (si->myname) free(si->myname);
 	if (si->peername) free(si->peername);
 	if (si->tmp_path) {
@@ -2534,3 +2534,121 @@ _PUBLIC_ int swrap_close(int fd)
 
 	return ret;
 }
+
+_PUBLIC_ int swrap_dup(int fd)
+{
+	struct socket_info *si, *si2;
+	int fd2;
+
+	si = find_socket_info(fd);
+
+	if (!si) {
+		return real_dup(fd);
+	}
+
+	if (si->tmp_path) {
+		/* we would need reference counting to handle this */
+		errno = EINVAL;
+		return -1;
+	}
+
+	fd2 = real_dup(fd);
+	if (fd2 == -1) {
+		return -1;
+	}
+
+	si2 = (struct socket_info *)malloc(sizeof(struct socket_info));
+	if (si2 == NULL) {
+		real_close(fd2);
+		errno = ENOMEM;
+		return -1;
+	}
+
+	/* copy the whole structure, then duplicate pointer elements */
+	*si2 = *si;
+
+	si2->fd = fd2;
+
+	if (si2->myname) {
+		si2->myname = sockaddr_dup(si2->myname, si2->myname_len);
+		if (si2->myname == NULL) {
+			real_close(fd2);
+			errno = ENOMEM;
+			return -1;
+		}
+	}
+
+	if (si2->peername) {
+		si2->peername = sockaddr_dup(si2->peername, si2->peername_len);
+		if (si2->peername == NULL) {
+			real_close(fd2);
+			errno = ENOMEM;
+			return -1;
+		}
+	}
+
+	SWRAP_DLIST_ADD(sockets, si2);
+	return fd2;
+}
+
+_PUBLIC_ int swrap_dup2(int fd, int newfd)
+{
+	struct socket_info *si, *si2;
+	int fd2;
+
+	si = find_socket_info(fd);
+
+	if (!si) {
+		return real_dup2(fd, newfd);
+	}
+
+	if (si->tmp_path) {
+		/* we would need reference counting to handle this */
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (find_socket_info(newfd)) {
+		/* dup2() does an implicit close of newfd, which we
+		 * need to emulate */
+		swrap_close(newfd);
+	}
+
+	fd2 = real_dup2(fd, newfd);
+	if (fd2 == -1) {
+		return -1;
+	}
+
+	si2 = (struct socket_info *)malloc(sizeof(struct socket_info));
+	if (si2 == NULL) {
+		real_close(fd2);
+		errno = ENOMEM;
+		return -1;
+	}
+
+	/* copy the whole structure, then duplicate pointer elements */
+	*si2 = *si;
+
+	si2->fd = fd2;
+
+	if (si2->myname) {
+		si2->myname = sockaddr_dup(si2->myname, si2->myname_len);
+		if (si2->myname == NULL) {
+			real_close(fd2);
+			errno = ENOMEM;
+			return -1;
+		}
+	}
+
+	if (si2->peername) {
+		si2->peername = sockaddr_dup(si2->peername, si2->peername_len);
+		if (si2->peername == NULL) {
+			real_close(fd2);
+			errno = ENOMEM;
+			return -1;
+		}
+	}
+
+	SWRAP_DLIST_ADD(sockets, si2);
+	return fd2;
+}
diff --git a/lib/socket_wrapper/socket_wrapper.h b/lib/socket_wrapper/socket_wrapper.h
index 77af6feadd..32c9de6b68 100644
--- a/lib/socket_wrapper/socket_wrapper.h
+++ b/lib/socket_wrapper/socket_wrapper.h
@@ -58,6 +58,8 @@ ssize_t swrap_send(int s, const void *buf, size_t len, int flags);
 int swrap_readv(int s, const struct iovec *vector, size_t count);
 int swrap_writev(int s, const struct iovec *vector, size_t count);
 int swrap_close(int);
+int swrap_dup(int oldfd);
+int swrap_dup2(int oldfd, int newfd);
 
 #ifdef SOCKET_WRAPPER_REPLACE
 
@@ -160,7 +162,16 @@ int swrap_close(int);
 #undef close
 #endif
 #define close(s)			swrap_close(s)
+
+#ifdef dup
+#undef dup
 #endif
+#define dup(s)			swrap_dup(s)
 
+#ifdef dup2
+#undef dup2
+#endif
+#define dup2(s, s2)		swrap_dup2(s, s2)
 
+#endif /* SOCKET_WRAPPER_REPLACE */
 #endif /* __SOCKET_WRAPPER_H__ */