![Eric W. Biederman](/assets/img/avatar_default.png)
In preparation for supporting the creation of network namespaces by unprivileged users, modify all of the per net sysctl exports and refuse to allow them to unprivileged users. This makes it safe for unprivileged users in general to access per net sysctls, and allows sysctls to be exported to unprivileged users on an individual basis as they are deemed safe. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
142 lines
3.2 KiB
C
142 lines
3.2 KiB
C
/* Accouting handling for netfilter. */
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/*
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* (C) 2008 Krzysztof Piotr Oledzki <ole@ans.pl>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/netfilter.h>
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#include <linux/slab.h>
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#include <linux/kernel.h>
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#include <linux/moduleparam.h>
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#include <linux/export.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_extend.h>
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#include <net/netfilter/nf_conntrack_acct.h>
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static bool nf_ct_acct __read_mostly;
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module_param_named(acct, nf_ct_acct, bool, 0644);
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MODULE_PARM_DESC(acct, "Enable connection tracking flow accounting.");
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#ifdef CONFIG_SYSCTL
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static struct ctl_table acct_sysctl_table[] = {
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{
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.procname = "nf_conntrack_acct",
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.data = &init_net.ct.sysctl_acct,
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.maxlen = sizeof(unsigned int),
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.mode = 0644,
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.proc_handler = proc_dointvec,
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},
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{}
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};
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#endif /* CONFIG_SYSCTL */
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unsigned int
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seq_print_acct(struct seq_file *s, const struct nf_conn *ct, int dir)
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{
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struct nf_conn_counter *acct;
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acct = nf_conn_acct_find(ct);
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if (!acct)
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return 0;
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return seq_printf(s, "packets=%llu bytes=%llu ",
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(unsigned long long)atomic64_read(&acct[dir].packets),
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(unsigned long long)atomic64_read(&acct[dir].bytes));
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};
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EXPORT_SYMBOL_GPL(seq_print_acct);
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static struct nf_ct_ext_type acct_extend __read_mostly = {
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.len = sizeof(struct nf_conn_counter[IP_CT_DIR_MAX]),
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.align = __alignof__(struct nf_conn_counter[IP_CT_DIR_MAX]),
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.id = NF_CT_EXT_ACCT,
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};
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#ifdef CONFIG_SYSCTL
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static int nf_conntrack_acct_init_sysctl(struct net *net)
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{
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struct ctl_table *table;
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table = kmemdup(acct_sysctl_table, sizeof(acct_sysctl_table),
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GFP_KERNEL);
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if (!table)
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goto out;
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table[0].data = &net->ct.sysctl_acct;
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/* Don't export sysctls to unprivileged users */
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if (net->user_ns != &init_user_ns)
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table[0].procname = NULL;
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net->ct.acct_sysctl_header = register_net_sysctl(net, "net/netfilter",
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table);
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if (!net->ct.acct_sysctl_header) {
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printk(KERN_ERR "nf_conntrack_acct: can't register to sysctl.\n");
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goto out_register;
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}
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return 0;
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out_register:
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kfree(table);
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out:
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return -ENOMEM;
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}
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static void nf_conntrack_acct_fini_sysctl(struct net *net)
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{
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struct ctl_table *table;
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table = net->ct.acct_sysctl_header->ctl_table_arg;
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unregister_net_sysctl_table(net->ct.acct_sysctl_header);
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kfree(table);
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}
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#else
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static int nf_conntrack_acct_init_sysctl(struct net *net)
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{
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return 0;
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}
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static void nf_conntrack_acct_fini_sysctl(struct net *net)
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{
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}
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#endif
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int nf_conntrack_acct_init(struct net *net)
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{
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int ret;
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net->ct.sysctl_acct = nf_ct_acct;
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if (net_eq(net, &init_net)) {
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ret = nf_ct_extend_register(&acct_extend);
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if (ret < 0) {
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printk(KERN_ERR "nf_conntrack_acct: Unable to register extension\n");
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goto out_extend_register;
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}
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}
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ret = nf_conntrack_acct_init_sysctl(net);
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if (ret < 0)
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goto out_sysctl;
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return 0;
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out_sysctl:
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if (net_eq(net, &init_net))
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nf_ct_extend_unregister(&acct_extend);
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out_extend_register:
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return ret;
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}
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void nf_conntrack_acct_fini(struct net *net)
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{
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nf_conntrack_acct_fini_sysctl(net);
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if (net_eq(net, &init_net))
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nf_ct_extend_unregister(&acct_extend);
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}
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