ANDROID: revert "sysfs_net_ipv4: Add sysfs-based knobs for controlling TCP window size"

This reverts commit 41b377f5495f16a193546cf9cb09fb72cfbb07f5.

Q userspace no longer requires these tunables, and the 4.19 android common kernel
no longer carries this patch, so revert it also in 4.9 android common kernel.

Bug: 126767155
Signed-off-by: Maciej ┼╗enczykowski <maze@google.com>
Change-Id: Ic1e71701b873f153ae067d15f675479eee249333
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index a8b934a..bc6a6c8 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -16,7 +16,6 @@
 
 obj-$(CONFIG_NET_IP_TUNNEL) += ip_tunnel.o
 obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o
-obj-$(CONFIG_SYSFS) += sysfs_net_ipv4.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_IP_MULTIPLE_TABLES) += fib_rules.o
 obj-$(CONFIG_IP_MROUTE) += ipmr.o
diff --git a/net/ipv4/sysfs_net_ipv4.c b/net/ipv4/sysfs_net_ipv4.c
deleted file mode 100644
index 0cbbf10..0000000
--- a/net/ipv4/sysfs_net_ipv4.c
+++ /dev/null
@@ -1,88 +0,0 @@
-/*
- * net/ipv4/sysfs_net_ipv4.c
- *
- * sysfs-based networking knobs (so we can, unlike with sysctl, control perms)
- *
- * Copyright (C) 2008 Google, Inc.
- *
- * Robert Love <rlove@google.com>
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
-
-#include <linux/kobject.h>
-#include <linux/string.h>
-#include <linux/sysfs.h>
-#include <linux/init.h>
-#include <net/tcp.h>
-
-#define CREATE_IPV4_FILE(_name, _var) \
-static ssize_t _name##_show(struct kobject *kobj, \
-			    struct kobj_attribute *attr, char *buf) \
-{ \
-	return sprintf(buf, "%d\n", _var); \
-} \
-static ssize_t _name##_store(struct kobject *kobj, \
-			     struct kobj_attribute *attr, \
-			     const char *buf, size_t count) \
-{ \
-	int val, ret; \
-	ret = sscanf(buf, "%d", &val); \
-	if (ret != 1) \
-		return -EINVAL; \
-	if (val < 0) \
-		return -EINVAL; \
-	_var = val; \
-	return count; \
-} \
-static struct kobj_attribute _name##_attr = \
-	__ATTR(_name, 0644, _name##_show, _name##_store)
-
-CREATE_IPV4_FILE(tcp_wmem_min, sysctl_tcp_wmem[0]);
-CREATE_IPV4_FILE(tcp_wmem_def, sysctl_tcp_wmem[1]);
-CREATE_IPV4_FILE(tcp_wmem_max, sysctl_tcp_wmem[2]);
-
-CREATE_IPV4_FILE(tcp_rmem_min, sysctl_tcp_rmem[0]);
-CREATE_IPV4_FILE(tcp_rmem_def, sysctl_tcp_rmem[1]);
-CREATE_IPV4_FILE(tcp_rmem_max, sysctl_tcp_rmem[2]);
-
-static struct attribute *ipv4_attrs[] = {
-	&tcp_wmem_min_attr.attr,
-	&tcp_wmem_def_attr.attr,
-	&tcp_wmem_max_attr.attr,
-	&tcp_rmem_min_attr.attr,
-	&tcp_rmem_def_attr.attr,
-	&tcp_rmem_max_attr.attr,
-	NULL
-};
-
-static struct attribute_group ipv4_attr_group = {
-	.attrs = ipv4_attrs,
-};
-
-static __init int sysfs_ipv4_init(void)
-{
-	struct kobject *ipv4_kobject;
-	int ret;
-
-	ipv4_kobject = kobject_create_and_add("ipv4", kernel_kobj);
-	if (!ipv4_kobject)
-		return -ENOMEM;
-
-	ret = sysfs_create_group(ipv4_kobject, &ipv4_attr_group);
-	if (ret) {
-		kobject_put(ipv4_kobject);
-		return ret;
-	}
-
-	return 0;
-}
-
-subsys_initcall(sysfs_ipv4_init);