Add blind-from-named and blind-to-named

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 84 insertions, 0 deletions

diff --git a/src/blind-to-named.c b/src/blind-to-named.c
new file mode 100644
index 0000000..a42f771
--- /dev/null
+++ b/src/blind-to-named.c
@@ -0,0 +1,84 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+USAGE("[-a] path")
+
+static void
+esend_fd(int sock, int fd)
+{
+	char buf[1];
+	struct iovec iov;
+	struct msghdr msg;
+	struct cmsghdr *cmsg;
+	char cms[CMSG_SPACE(sizeof(fd))];
+
+	buf[0] = 0;
+	iov.iov_base = buf;
+	iov.iov_len = 1;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	msg.msg_control = (caddr_t)cms;
+	msg.msg_controllen = CMSG_LEN(sizeof(fd));
+
+	cmsg = CMSG_FIRSTHDR(&msg);
+	cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
+	cmsg->cmsg_level = SOL_SOCKET;
+	cmsg->cmsg_type = SCM_RIGHTS;
+	memcpy(CMSG_DATA(cmsg), &fd, sizeof(fd));
+
+	if (sendmsg(sock, &msg, 0) != iov.iov_len)
+		eprintf("sendmsg:");
+}
+
+int
+main(int argc, char *argv[])
+{
+	struct sockaddr_un addr;
+	int abstract = 0;
+	int serverfd, connfd;
+
+	ARGBEGIN {
+	case 'a':
+		abstract = 1;
+		break;
+	default:
+		usage();
+	} ARGEND;
+	if (argc != 1)
+		usage();
+
+	memset(&addr, 0, sizeof(addr));
+	addr.sun_family = AF_UNIX;
+	if (strlen(argv[0]) + 1 + abstract > sizeof(addr.sun_path)) {
+		errno = ENAMETOOLONG;
+		eprintf("%s:", argv[0]);
+	}
+	strcpy(addr.sun_path + abstract, argv[0]);
+
+	serverfd = socket(PF_UNIX, SOCK_SEQPACKET, 0);
+	if (serverfd < 0)
+		eprintf("socket PF_UNIX SOCK_SEQPACKET:");
+
+	if (bind(serverfd, (const struct sockaddr *)&addr, (size_t)sizeof(addr)) < 0)
+		eprintf("bind %s%s%s:",
+			abstract ? "<abstract:" : "",
+			addr.sun_path + abstract,
+			abstract ? ">" : "");
+
+	if (listen(serverfd, 1) < 0)
+		eprintf("listen:");
+
+	connfd = accept(serverfd, NULL, NULL);
+	if (connfd < 0)
+		eprintf("accept:");
+
+	if (*addr.sun_path)
+		unlink(addr.sun_path);
+	close(serverfd);
+
+	esend_fd(connfd, STDIN_FILENO);
+	close(connfd);
+	return 0;
+}