From 75090d40ffbd9b4863238e1d62b43f8598da5e5e Mon Sep 17 00:00:00 2001 From: Robert Love <rlove@google.com> Date: Thu, 31 Jul 2008 11:12:44 -0400 Subject: [PATCH 082/134] sysfs_net_ipv4: Add sysfs-based knobs for controlling TCP window size 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> --- net/ipv4/Makefile | 1 + net/ipv4/sysfs_net_ipv4.c | 88 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 89 insertions(+), 0 deletions(-) create mode 100644 net/ipv4/sysfs_net_ipv4.c --- a/net/ipv4/Makefile +++ b/net/ipv4/Makefile @@ -14,6 +14,7 @@ obj-y := route.o inetpeer.o protocol inet_fragment.o obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o +obj-$(CONFIG_SYSFS) += sysfs_net_ipv4.o obj-$(CONFIG_IP_FIB_HASH) += fib_hash.o obj-$(CONFIG_IP_FIB_TRIE) += fib_trie.o obj-$(CONFIG_PROC_FS) += proc.o --- /dev/null +++ b/net/ipv4/sysfs_net_ipv4.c @@ -0,0 +1,88 @@ +/* + * 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);