| 1 | From 75090d40ffbd9b4863238e1d62b43f8598da5e5e Mon Sep 17 00:00:00 2001 |
| 2 | From: Robert Love <rlove@google.com> |
| 3 | Date: Thu, 31 Jul 2008 11:12:44 -0400 |
| 4 | Subject: [PATCH 082/134] sysfs_net_ipv4: Add sysfs-based knobs for controlling TCP window size |
| 5 | |
| 6 | Add a family of knobs to /sys/kernel/ipv4 for controlling the TCP window size: |
| 7 | |
| 8 | tcp_wmem_min |
| 9 | tcp_wmem_def |
| 10 | tcp_wmem_max |
| 11 | tcp_rmem_min |
| 12 | tcp_rmem_def |
| 13 | tcp_rmem_max |
| 14 | |
| 15 | This six values mirror the sysctl knobs in /proc/sys/net/ipv4/tcp_wmem and |
| 16 | /proc/sys/net/ipv4/tcp_rmem. |
| 17 | |
| 18 | Sysfs, unlike sysctl, allows us to set and manage the files' permissions and |
| 19 | owners. |
| 20 | |
| 21 | Signed-off-by: Robert Love <rlove@google.com> |
| 22 | --- |
| 23 | net/ipv4/Makefile | 1 + |
| 24 | net/ipv4/sysfs_net_ipv4.c | 88 +++++++++++++++++++++++++++++++++++++++++++++ |
| 25 | 2 files changed, 89 insertions(+), 0 deletions(-) |
| 26 | create mode 100644 net/ipv4/sysfs_net_ipv4.c |
| 27 | |
| 28 | --- a/net/ipv4/Makefile |
| 29 | +++ b/net/ipv4/Makefile |
| 30 | @@ -14,6 +14,7 @@ obj-y := route.o inetpeer.o protocol |
| 31 | inet_fragment.o |
| 32 | |
| 33 | obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o |
| 34 | +obj-$(CONFIG_SYSFS) += sysfs_net_ipv4.o |
| 35 | obj-$(CONFIG_IP_FIB_HASH) += fib_hash.o |
| 36 | obj-$(CONFIG_IP_FIB_TRIE) += fib_trie.o |
| 37 | obj-$(CONFIG_PROC_FS) += proc.o |
| 38 | --- /dev/null |
| 39 | +++ b/net/ipv4/sysfs_net_ipv4.c |
| 40 | @@ -0,0 +1,88 @@ |
| 41 | +/* |
| 42 | + * net/ipv4/sysfs_net_ipv4.c |
| 43 | + * |
| 44 | + * sysfs-based networking knobs (so we can, unlike with sysctl, control perms) |
| 45 | + * |
| 46 | + * Copyright (C) 2008 Google, Inc. |
| 47 | + * |
| 48 | + * Robert Love <rlove@google.com> |
| 49 | + * |
| 50 | + * This software is licensed under the terms of the GNU General Public |
| 51 | + * License version 2, as published by the Free Software Foundation, and |
| 52 | + * may be copied, distributed, and modified under those terms. |
| 53 | + * |
| 54 | + * This program is distributed in the hope that it will be useful, |
| 55 | + * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 56 | + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 57 | + * GNU General Public License for more details. |
| 58 | + */ |
| 59 | + |
| 60 | +#include <linux/kobject.h> |
| 61 | +#include <linux/string.h> |
| 62 | +#include <linux/sysfs.h> |
| 63 | +#include <linux/init.h> |
| 64 | +#include <net/tcp.h> |
| 65 | + |
| 66 | +#define CREATE_IPV4_FILE(_name, _var) \ |
| 67 | +static ssize_t _name##_show(struct kobject *kobj, \ |
| 68 | + struct kobj_attribute *attr, char *buf) \ |
| 69 | +{ \ |
| 70 | + return sprintf(buf, "%d\n", _var); \ |
| 71 | +} \ |
| 72 | +static ssize_t _name##_store(struct kobject *kobj, \ |
| 73 | + struct kobj_attribute *attr, \ |
| 74 | + const char *buf, size_t count) \ |
| 75 | +{ \ |
| 76 | + int val, ret; \ |
| 77 | + ret = sscanf(buf, "%d", &val); \ |
| 78 | + if (ret != 1) \ |
| 79 | + return -EINVAL; \ |
| 80 | + if (val < 0) \ |
| 81 | + return -EINVAL; \ |
| 82 | + _var = val; \ |
| 83 | + return count; \ |
| 84 | +} \ |
| 85 | +static struct kobj_attribute _name##_attr = \ |
| 86 | + __ATTR(_name, 0644, _name##_show, _name##_store) |
| 87 | + |
| 88 | +CREATE_IPV4_FILE(tcp_wmem_min, sysctl_tcp_wmem[0]); |
| 89 | +CREATE_IPV4_FILE(tcp_wmem_def, sysctl_tcp_wmem[1]); |
| 90 | +CREATE_IPV4_FILE(tcp_wmem_max, sysctl_tcp_wmem[2]); |
| 91 | + |
| 92 | +CREATE_IPV4_FILE(tcp_rmem_min, sysctl_tcp_rmem[0]); |
| 93 | +CREATE_IPV4_FILE(tcp_rmem_def, sysctl_tcp_rmem[1]); |
| 94 | +CREATE_IPV4_FILE(tcp_rmem_max, sysctl_tcp_rmem[2]); |
| 95 | + |
| 96 | +static struct attribute *ipv4_attrs[] = { |
| 97 | + &tcp_wmem_min_attr.attr, |
| 98 | + &tcp_wmem_def_attr.attr, |
| 99 | + &tcp_wmem_max_attr.attr, |
| 100 | + &tcp_rmem_min_attr.attr, |
| 101 | + &tcp_rmem_def_attr.attr, |
| 102 | + &tcp_rmem_max_attr.attr, |
| 103 | + NULL |
| 104 | +}; |
| 105 | + |
| 106 | +static struct attribute_group ipv4_attr_group = { |
| 107 | + .attrs = ipv4_attrs, |
| 108 | +}; |
| 109 | + |
| 110 | +static __init int sysfs_ipv4_init(void) |
| 111 | +{ |
| 112 | + struct kobject *ipv4_kobject; |
| 113 | + int ret; |
| 114 | + |
| 115 | + ipv4_kobject = kobject_create_and_add("ipv4", kernel_kobj); |
| 116 | + if (!ipv4_kobject) |
| 117 | + return -ENOMEM; |
| 118 | + |
| 119 | + ret = sysfs_create_group(ipv4_kobject, &ipv4_attr_group); |
| 120 | + if (ret) { |
| 121 | + kobject_put(ipv4_kobject); |
| 122 | + return ret; |
| 123 | + } |
| 124 | + |
| 125 | + return 0; |
| 126 | +} |
| 127 | + |
| 128 | +subsys_initcall(sysfs_ipv4_init); |
| 129 | |
