8f414ea43f
Add a family of knobs to /sys/kernel/ipv4 for controlling the TCP window size: tcp_wmem_min tcp_wmem_def tcp_wmem_max tcp_rmem_min tcp_rmem_def tcp_rmem_max This six values mirror the sysctl knobs in /proc/sys/net/ipv4/tcp_wmem and /proc/sys/net/ipv4/tcp_rmem. Sysfs, unlike sysctl, allows us to set and manage the files' permissions and owners. Signed-off-by: Robert Love <rlove@google.com>
88 lines
2.3 KiB
C
88 lines
2.3 KiB
C
/*
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* net/ipv4/sysfs_net_ipv4.c
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*
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* sysfs-based networking knobs (so we can, unlike with sysctl, control perms)
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*
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* Copyright (C) 2008 Google, Inc.
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*
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* Robert Love <rlove@google.com>
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/kobject.h>
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#include <linux/string.h>
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#include <linux/sysfs.h>
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#include <linux/init.h>
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#include <net/tcp.h>
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#define CREATE_IPV4_FILE(_name, _var) \
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static ssize_t _name##_show(struct kobject *kobj, \
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struct kobj_attribute *attr, char *buf) \
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{ \
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return sprintf(buf, "%d\n", _var); \
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} \
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static ssize_t _name##_store(struct kobject *kobj, \
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struct kobj_attribute *attr, \
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const char *buf, size_t count) \
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{ \
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int val, ret; \
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ret = sscanf(buf, "%d", &val); \
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if (ret != 1) \
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return -EINVAL; \
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if (val < 0) \
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return -EINVAL; \
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_var = val; \
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return count; \
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} \
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static struct kobj_attribute _name##_attr = \
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__ATTR(_name, 0644, _name##_show, _name##_store)
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CREATE_IPV4_FILE(tcp_wmem_min, sysctl_tcp_wmem[0]);
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CREATE_IPV4_FILE(tcp_wmem_def, sysctl_tcp_wmem[1]);
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CREATE_IPV4_FILE(tcp_wmem_max, sysctl_tcp_wmem[2]);
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CREATE_IPV4_FILE(tcp_rmem_min, sysctl_tcp_rmem[0]);
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CREATE_IPV4_FILE(tcp_rmem_def, sysctl_tcp_rmem[1]);
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CREATE_IPV4_FILE(tcp_rmem_max, sysctl_tcp_rmem[2]);
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static struct attribute *ipv4_attrs[] = {
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&tcp_wmem_min_attr.attr,
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&tcp_wmem_def_attr.attr,
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&tcp_wmem_max_attr.attr,
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&tcp_rmem_min_attr.attr,
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&tcp_rmem_def_attr.attr,
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&tcp_rmem_max_attr.attr,
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NULL
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};
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static struct attribute_group ipv4_attr_group = {
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.attrs = ipv4_attrs,
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};
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static __init int sysfs_ipv4_init(void)
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{
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struct kobject *ipv4_kobject;
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int ret;
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ipv4_kobject = kobject_create_and_add("ipv4", kernel_kobj);
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if (!ipv4_kobject)
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return -ENOMEM;
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ret = sysfs_create_group(ipv4_kobject, &ipv4_attr_group);
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if (ret) {
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kobject_put(ipv4_kobject);
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return ret;
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}
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return 0;
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}
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subsys_initcall(sysfs_ipv4_init);
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