From ea140db712dfed29f4484f6742cc198382a21c3c Mon Sep 17 00:00:00 2001
From: Kir Kolyshkin <kolyshkin@gmail.com>
Date: Mon, 12 Feb 2024 13:08:12 -0800
Subject: [PATCH 1/2] libct/nsenter: rm unused code

Commits b999376f and b999376f removed all users of this code.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
---
 libcontainer/nsenter/ipc.c    | 84 -----------------------------------
 libcontainer/nsenter/ipc.h    | 12 -----
 libcontainer/nsenter/nsexec.c |  1 -
 3 files changed, 97 deletions(-)
 delete mode 100644 libcontainer/nsenter/ipc.c
 delete mode 100644 libcontainer/nsenter/ipc.h

diff --git a/libcontainer/nsenter/ipc.c b/libcontainer/nsenter/ipc.c
deleted file mode 100644
index 01321a718..000000000
--- a/libcontainer/nsenter/ipc.c
+++ /dev/null
@@ -1,84 +0,0 @@
-#define _GNU_SOURCE
-#include <alloca.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/socket.h>
-#include "ipc.h"
-#include "log.h"
-
-int receive_fd(int sockfd)
-{
-	int bytes_read;
-	struct msghdr msg = { };
-	struct cmsghdr *cmsg;
-	struct iovec iov = { };
-	char null_byte = '\0';
-	int ret;
-	int fd_count;
-
-	iov.iov_base = &null_byte;
-	iov.iov_len = 1;
-
-	msg.msg_iov = &iov;
-	msg.msg_iovlen = 1;
-
-	msg.msg_controllen = CMSG_SPACE(sizeof(int));
-	msg.msg_control = malloc(msg.msg_controllen);
-	if (msg.msg_control == NULL) {
-		bail("Can't allocate memory to receive fd.");
-	}
-
-	memset(msg.msg_control, 0, msg.msg_controllen);
-
-	bytes_read = recvmsg(sockfd, &msg, MSG_CMSG_CLOEXEC);
-	if (bytes_read != 1)
-		bail("failed to receive fd from unix socket %d", sockfd);
-	if (msg.msg_flags & MSG_CTRUNC)
-		bail("received truncated control message from unix socket %d", sockfd);
-
-	cmsg = CMSG_FIRSTHDR(&msg);
-	if (!cmsg)
-		bail("received message from unix socket %d without control message", sockfd);
-
-	if (cmsg->cmsg_level != SOL_SOCKET)
-		bail("received unknown control message from unix socket %d: cmsg_level=%d", sockfd, cmsg->cmsg_level);
-
-	if (cmsg->cmsg_type != SCM_RIGHTS)
-		bail("received unknown control message from unix socket %d: cmsg_type=%d", sockfd, cmsg->cmsg_type);
-
-	fd_count = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
-	if (fd_count != 1)
-		bail("received control message from unix socket %d with too many fds: %d", sockfd, fd_count);
-
-	ret = *(int *)CMSG_DATA(cmsg);
-	free(msg.msg_control);
-	return ret;
-}
-
-int send_fd(int sockfd, int fd)
-{
-	struct msghdr msg = { };
-	struct cmsghdr *cmsg;
-	struct iovec iov[1] = { };
-	char null_byte = '\0';
-
-	iov[0].iov_base = &null_byte;
-	iov[0].iov_len = 1;
-
-	msg.msg_iov = iov;
-	msg.msg_iovlen = 1;
-
-	/* We send only one fd as specified by cmsg->cmsg_len below, even
-	 * though msg.msg_controllen might have more space due to alignment. */
-	msg.msg_controllen = CMSG_SPACE(sizeof(int));
-	msg.msg_control = alloca(msg.msg_controllen);
-	memset(msg.msg_control, 0, msg.msg_controllen);
-
-	cmsg = CMSG_FIRSTHDR(&msg);
-	cmsg->cmsg_level = SOL_SOCKET;
-	cmsg->cmsg_type = SCM_RIGHTS;
-	cmsg->cmsg_len = CMSG_LEN(sizeof(int));
-	memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
-
-	return sendmsg(sockfd, &msg, 0);
-}
diff --git a/libcontainer/nsenter/ipc.h b/libcontainer/nsenter/ipc.h
deleted file mode 100644
index 6e5972697..000000000
--- a/libcontainer/nsenter/ipc.h
+++ /dev/null
@@ -1,12 +0,0 @@
-#ifndef NSENTER_IPC_H
-#define NSENTER_IPC_H
-
-int receive_fd(int sockfd);
-
-/*
- * send_fd passes the open file descriptor fd to another process via the UNIX
- * domain socket sockfd. The return value of the sendmsg(2) call is returned.
- */
-int send_fd(int sockfd, int fd);
-
-#endif /* NSENTER_IPC_H */
diff --git a/libcontainer/nsenter/nsexec.c b/libcontainer/nsenter/nsexec.c
index bfc6a79a8..adfc0d41a 100644
--- a/libcontainer/nsenter/nsexec.c
+++ b/libcontainer/nsenter/nsexec.c
@@ -28,7 +28,6 @@
 #include <linux/types.h>
 
 #include "getenv.h"
-#include "ipc.h"
 #include "log.h"
 /* Get all of the CLONE_NEW* flags. */
 #include "namespace.h"

From 3a9859bdc0e4507cb57fb46fd10b422702cfda62 Mon Sep 17 00:00:00 2001
From: Kir Kolyshkin <kolyshkin@gmail.com>
Date: Mon, 12 Feb 2024 13:17:47 -0800
Subject: [PATCH 2/2] libct/nsenter: rm unused include

This was added by commit 9c444070 (to use LONG_MAX and INT_MAX) but the
code was later removed by commit ba0b5e26.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
---
 libcontainer/nsenter/nsexec.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/libcontainer/nsenter/nsexec.c b/libcontainer/nsenter/nsexec.c
index adfc0d41a..c771ac7e1 100644
--- a/libcontainer/nsenter/nsexec.c
+++ b/libcontainer/nsenter/nsexec.c
@@ -4,7 +4,6 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <grp.h>
-#include <limits.h>
 #include <sched.h>
 #include <setjmp.h>
 #include <signal.h>