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

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

3 files changed, 255 insertions, 0 deletions

diff --git a/src/blind-from-named.c b/src/blind-from-named.c
new file mode 100644
index 0000000..1ca4c7f
--- /dev/null
+++ b/src/blind-from-named.c
@@ -0,0 +1,149 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+USAGE("[-t decisecs] [-a] ([-f fd] path [command ...] | path)")
+
+static int
+erecv_fd(int sock)
+{
+	int fd;
+	char buf[1];
+	struct iovec iov;
+	struct msghdr msg;
+	struct cmsghdr *cmsg;
+	char cms[CMSG_SPACE(sizeof(fd))];
+
+	iov.iov_base = buf;
+	iov.iov_len = 1;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.msg_name = 0;
+	msg.msg_namelen = 0;
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+
+	msg.msg_control = (caddr_t)cms;
+	msg.msg_controllen = sizeof(cms);
+
+	switch (recvmsg(sock, &msg, 0)) {
+	case -1:
+		eprintf("recvmsg:");
+	case 0:
+		eprintf("recvmsg: connection closed by peer");
+	default:
+		break;
+	}
+
+	cmsg = CMSG_FIRSTHDR(&msg);
+	memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd));
+	return fd;
+}
+
+#if !defined(HAVE_SENDFILE)
+# if !defined(PIPE_BUF)
+#  define PIPE_BUF BUFSIZ
+# endif
+static ssize_t
+sendfile(int outfd, int infd, off_t *offset, size_t count)
+{
+	char buf[PIPE_BUF];
+	ssize_t r, w, p, ret = 0;
+
+	(void) offset;
+	(void) count;
+
+	for (;;) {
+		r = read(infd, buf, sizeof(buf));
+		if (r < 0)
+			eprintf("read <received file>:");
+		if (!r)
+			break;
+		ret += r;
+		for (p = 0; p < r; p += w) {
+			w = write(outfd, buf + p, r - p);
+			if (w < 0)
+				eprintf("write <stdout>:");
+		}
+	}
+
+	return ret;
+}
+#endif
+
+int
+main(int argc, char *argv[])
+{
+	struct sockaddr_un addr;
+	int abstract = 0;
+	int filedes = -1;
+	int tries = 10;
+	int sockfd, fd;
+
+	ARGBEGIN {
+	case 'a':
+		abstract = 1;
+		break;
+	case 'f':
+		filedes = etoi_flag('f', UARGF(), 0, INT_MAX);
+		break;
+	case 't':
+		tries = etoi_flag('t', UARGF(), 1, INT_MAX);
+		break;
+	default:
+		usage();
+	} ARGEND;
+	if (argc < 1 || (filedes >= 0 && argc > 1))
+		usage();
+	if (argc > 0 && filedes < 0)
+		filedes = 0;
+
+	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]);
+	argv++, argc--;
+
+	sockfd = socket(PF_UNIX, SOCK_SEQPACKET, 0);
+	if (sockfd < 0)
+		eprintf("socket PF_UNIX SOCK_SEQPACKET:");
+
+retry:
+	if ((connect(sockfd, (const struct sockaddr *)&addr, (size_t)sizeof(addr))) < 0) {
+		if (--tries) {
+			usleep((useconds_t)100000L);
+			goto retry;
+		} else {
+			eprintf("bind %s%s%s:",
+				abstract ? "<abstract:" : "",
+				addr.sun_path + abstract,
+				abstract ? ">" : "");
+		}
+	}
+
+	fd = erecv_fd(sockfd);
+	close(sockfd);
+
+	if (argc) {
+		if (fd != filedes) {
+			if (dup2(fd, filedes) < 0)
+				eprintf("dup2 %i %i:", fd, filedes);
+			close(fd);
+		}
+		execvp(argv[0], argv);
+		eprintf("execvp %s:", argv[0]);
+	}
+
+	for (;;) {
+		switch (sendfile(STDOUT_FILENO, fd, NULL, SIZE_MAX)) {
+		case 0:
+			return 0;
+		case -1:
+			eprintf("sendfile <stdout> <received file>:");
+		default:
+			break;
+		}
+	}
+}
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;
+}
diff --git a/src/common.h b/src/common.h
index 3a746f8..3e3f966 100644
--- a/src/common.h
+++ b/src/common.h
@@ -20,7 +20,13 @@
 # include <sys/epoll.h>
 #endif
 #include <sys/mman.h>
+#if defined(HAVE_SENDFILE)
+# include <sys/sendfile.h>
+#endif
 #include <sys/stat.h>
+#include <sys/socket.h>
+#include <sys/uio.h>
+#include <sys/un.h>
 #include <sys/wait.h>
 #include <alloca.h>
 #include <ctype.h>
@@ -35,3 +41,19 @@
 #include <string.h>
 #include <strings.h>
 #include <unistd.h>
+
+#ifndef CMSG_ALIGN
+# ifdef __sun__
+#  define CMSG_ALIGN _CMSG_DATA_ALIGN
+# else
+#  define CMSG_ALIGN(len) (((len) + sizeof(long) - 1) & ~(sizeof(long) - 1))
+# endif
+#endif
+
+#ifndef CMSG_SPACE
+# define CMSG_SPACE(len) (CMSG_ALIGN(sizeof(struct cmsghdr)) + CMSG_ALIGN(len))
+#endif
+
+#ifndef CMSG_LEN
+# define CMSG_LEN(len) (CMSG_ALIGN(sizeof(struct cmsghdr)) + (len))
+#endif