target/linux/goldfish/patches-2.6.30/0082-sysfs_net_ipv4-Add-sysfs-based-knobs-for-controllin.patch

   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);