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![Arnd Bergmann](/assets/img/avatar_default.png)
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
668 lines
17 KiB
C
668 lines
17 KiB
C
/*
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* Copyright (c) 2006 Patrick McHardy <kaber@trash.net>
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* Copyright © CC Computer Consultants GmbH, 2007 - 2008
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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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* This is a replacement of the old ipt_recent module, which carried the
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* following copyright notice:
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*
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* Author: Stephen Frost <sfrost@snowman.net>
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* Copyright 2002-2003, Stephen Frost, 2.5.x port by laforge@netfilter.org
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/init.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/string.h>
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#include <linux/ctype.h>
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#include <linux/list.h>
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#include <linux/random.h>
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#include <linux/jhash.h>
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#include <linux/bitops.h>
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#include <linux/skbuff.h>
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#include <linux/inet.h>
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#include <linux/slab.h>
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#include <net/net_namespace.h>
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#include <net/netns/generic.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter/xt_recent.h>
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MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
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MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>");
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MODULE_DESCRIPTION("Xtables: \"recently-seen\" host matching");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("ipt_recent");
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MODULE_ALIAS("ip6t_recent");
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static unsigned int ip_list_tot = 100;
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static unsigned int ip_pkt_list_tot = 20;
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static unsigned int ip_list_hash_size = 0;
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static unsigned int ip_list_perms = 0644;
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static unsigned int ip_list_uid = 0;
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static unsigned int ip_list_gid = 0;
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module_param(ip_list_tot, uint, 0400);
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module_param(ip_pkt_list_tot, uint, 0400);
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module_param(ip_list_hash_size, uint, 0400);
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module_param(ip_list_perms, uint, 0400);
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module_param(ip_list_uid, uint, S_IRUGO | S_IWUSR);
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module_param(ip_list_gid, uint, S_IRUGO | S_IWUSR);
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MODULE_PARM_DESC(ip_list_tot, "number of IPs to remember per list");
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MODULE_PARM_DESC(ip_pkt_list_tot, "number of packets per IP address to remember (max. 255)");
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MODULE_PARM_DESC(ip_list_hash_size, "size of hash table used to look up IPs");
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MODULE_PARM_DESC(ip_list_perms, "permissions on /proc/net/xt_recent/* files");
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MODULE_PARM_DESC(ip_list_uid, "default owner of /proc/net/xt_recent/* files");
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MODULE_PARM_DESC(ip_list_gid, "default owning group of /proc/net/xt_recent/* files");
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struct recent_entry {
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struct list_head list;
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struct list_head lru_list;
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union nf_inet_addr addr;
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u_int16_t family;
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u_int8_t ttl;
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u_int8_t index;
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u_int16_t nstamps;
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unsigned long stamps[0];
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};
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struct recent_table {
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struct list_head list;
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char name[XT_RECENT_NAME_LEN];
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unsigned int refcnt;
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unsigned int entries;
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struct list_head lru_list;
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struct list_head iphash[0];
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};
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struct recent_net {
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struct list_head tables;
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#ifdef CONFIG_PROC_FS
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struct proc_dir_entry *xt_recent;
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#endif
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};
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static int recent_net_id;
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static inline struct recent_net *recent_pernet(struct net *net)
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{
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return net_generic(net, recent_net_id);
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}
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static DEFINE_SPINLOCK(recent_lock);
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static DEFINE_MUTEX(recent_mutex);
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#ifdef CONFIG_PROC_FS
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static const struct file_operations recent_old_fops, recent_mt_fops;
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#endif
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static u_int32_t hash_rnd __read_mostly;
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static bool hash_rnd_inited __read_mostly;
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static inline unsigned int recent_entry_hash4(const union nf_inet_addr *addr)
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{
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return jhash_1word((__force u32)addr->ip, hash_rnd) &
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(ip_list_hash_size - 1);
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}
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static inline unsigned int recent_entry_hash6(const union nf_inet_addr *addr)
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{
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return jhash2((u32 *)addr->ip6, ARRAY_SIZE(addr->ip6), hash_rnd) &
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(ip_list_hash_size - 1);
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}
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static struct recent_entry *
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recent_entry_lookup(const struct recent_table *table,
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const union nf_inet_addr *addrp, u_int16_t family,
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u_int8_t ttl)
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{
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struct recent_entry *e;
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unsigned int h;
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if (family == NFPROTO_IPV4)
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h = recent_entry_hash4(addrp);
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else
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h = recent_entry_hash6(addrp);
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list_for_each_entry(e, &table->iphash[h], list)
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if (e->family == family &&
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memcmp(&e->addr, addrp, sizeof(e->addr)) == 0 &&
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(ttl == e->ttl || ttl == 0 || e->ttl == 0))
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return e;
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return NULL;
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}
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static void recent_entry_remove(struct recent_table *t, struct recent_entry *e)
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{
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list_del(&e->list);
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list_del(&e->lru_list);
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kfree(e);
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t->entries--;
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}
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/*
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* Drop entries with timestamps older then 'time'.
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*/
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static void recent_entry_reap(struct recent_table *t, unsigned long time)
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{
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struct recent_entry *e;
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/*
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* The head of the LRU list is always the oldest entry.
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*/
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e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
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/*
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* The last time stamp is the most recent.
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*/
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if (time_after(time, e->stamps[e->index-1]))
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recent_entry_remove(t, e);
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}
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static struct recent_entry *
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recent_entry_init(struct recent_table *t, const union nf_inet_addr *addr,
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u_int16_t family, u_int8_t ttl)
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{
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struct recent_entry *e;
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if (t->entries >= ip_list_tot) {
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e = list_entry(t->lru_list.next, struct recent_entry, lru_list);
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recent_entry_remove(t, e);
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}
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e = kmalloc(sizeof(*e) + sizeof(e->stamps[0]) * ip_pkt_list_tot,
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GFP_ATOMIC);
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if (e == NULL)
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return NULL;
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memcpy(&e->addr, addr, sizeof(e->addr));
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e->ttl = ttl;
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e->stamps[0] = jiffies;
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e->nstamps = 1;
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e->index = 1;
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e->family = family;
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if (family == NFPROTO_IPV4)
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list_add_tail(&e->list, &t->iphash[recent_entry_hash4(addr)]);
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else
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list_add_tail(&e->list, &t->iphash[recent_entry_hash6(addr)]);
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list_add_tail(&e->lru_list, &t->lru_list);
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t->entries++;
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return e;
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}
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static void recent_entry_update(struct recent_table *t, struct recent_entry *e)
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{
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e->index %= ip_pkt_list_tot;
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e->stamps[e->index++] = jiffies;
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if (e->index > e->nstamps)
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e->nstamps = e->index;
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list_move_tail(&e->lru_list, &t->lru_list);
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}
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static struct recent_table *recent_table_lookup(struct recent_net *recent_net,
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const char *name)
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{
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struct recent_table *t;
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list_for_each_entry(t, &recent_net->tables, list)
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if (!strcmp(t->name, name))
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return t;
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return NULL;
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}
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static void recent_table_flush(struct recent_table *t)
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{
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struct recent_entry *e, *next;
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unsigned int i;
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for (i = 0; i < ip_list_hash_size; i++)
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list_for_each_entry_safe(e, next, &t->iphash[i], list)
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recent_entry_remove(t, e);
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}
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static bool
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recent_mt(const struct sk_buff *skb, struct xt_action_param *par)
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{
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struct net *net = dev_net(par->in ? par->in : par->out);
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struct recent_net *recent_net = recent_pernet(net);
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const struct xt_recent_mtinfo *info = par->matchinfo;
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struct recent_table *t;
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struct recent_entry *e;
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union nf_inet_addr addr = {};
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u_int8_t ttl;
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bool ret = info->invert;
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if (par->family == NFPROTO_IPV4) {
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const struct iphdr *iph = ip_hdr(skb);
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if (info->side == XT_RECENT_DEST)
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addr.ip = iph->daddr;
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else
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addr.ip = iph->saddr;
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ttl = iph->ttl;
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} else {
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const struct ipv6hdr *iph = ipv6_hdr(skb);
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if (info->side == XT_RECENT_DEST)
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memcpy(&addr.in6, &iph->daddr, sizeof(addr.in6));
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else
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memcpy(&addr.in6, &iph->saddr, sizeof(addr.in6));
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ttl = iph->hop_limit;
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}
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/* use TTL as seen before forwarding */
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if (par->out != NULL && skb->sk == NULL)
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ttl++;
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spin_lock_bh(&recent_lock);
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t = recent_table_lookup(recent_net, info->name);
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e = recent_entry_lookup(t, &addr, par->family,
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(info->check_set & XT_RECENT_TTL) ? ttl : 0);
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if (e == NULL) {
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if (!(info->check_set & XT_RECENT_SET))
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goto out;
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e = recent_entry_init(t, &addr, par->family, ttl);
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if (e == NULL)
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par->hotdrop = true;
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ret = !ret;
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goto out;
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}
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if (info->check_set & XT_RECENT_SET)
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ret = !ret;
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else if (info->check_set & XT_RECENT_REMOVE) {
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recent_entry_remove(t, e);
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ret = !ret;
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} else if (info->check_set & (XT_RECENT_CHECK | XT_RECENT_UPDATE)) {
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unsigned long time = jiffies - info->seconds * HZ;
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unsigned int i, hits = 0;
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for (i = 0; i < e->nstamps; i++) {
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if (info->seconds && time_after(time, e->stamps[i]))
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continue;
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if (!info->hit_count || ++hits >= info->hit_count) {
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ret = !ret;
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break;
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}
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}
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/* info->seconds must be non-zero */
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if (info->check_set & XT_RECENT_REAP)
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recent_entry_reap(t, time);
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}
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if (info->check_set & XT_RECENT_SET ||
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(info->check_set & XT_RECENT_UPDATE && ret)) {
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recent_entry_update(t, e);
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e->ttl = ttl;
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}
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out:
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spin_unlock_bh(&recent_lock);
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return ret;
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}
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static int recent_mt_check(const struct xt_mtchk_param *par)
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{
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struct recent_net *recent_net = recent_pernet(par->net);
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const struct xt_recent_mtinfo *info = par->matchinfo;
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struct recent_table *t;
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#ifdef CONFIG_PROC_FS
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struct proc_dir_entry *pde;
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#endif
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unsigned i;
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int ret = -EINVAL;
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if (unlikely(!hash_rnd_inited)) {
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get_random_bytes(&hash_rnd, sizeof(hash_rnd));
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hash_rnd_inited = true;
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}
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if (info->check_set & ~XT_RECENT_VALID_FLAGS) {
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pr_info("Unsupported user space flags (%08x)\n",
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info->check_set);
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return -EINVAL;
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}
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if (hweight8(info->check_set &
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(XT_RECENT_SET | XT_RECENT_REMOVE |
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XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1)
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return -EINVAL;
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if ((info->check_set & (XT_RECENT_SET | XT_RECENT_REMOVE)) &&
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(info->seconds || info->hit_count ||
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(info->check_set & XT_RECENT_MODIFIERS)))
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return -EINVAL;
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if ((info->check_set & XT_RECENT_REAP) && !info->seconds)
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return -EINVAL;
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if (info->hit_count > ip_pkt_list_tot) {
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pr_info("hitcount (%u) is larger than "
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"packets to be remembered (%u)\n",
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info->hit_count, ip_pkt_list_tot);
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return -EINVAL;
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}
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if (info->name[0] == '\0' ||
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strnlen(info->name, XT_RECENT_NAME_LEN) == XT_RECENT_NAME_LEN)
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return -EINVAL;
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mutex_lock(&recent_mutex);
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t = recent_table_lookup(recent_net, info->name);
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if (t != NULL) {
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t->refcnt++;
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ret = 0;
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goto out;
|
|
}
|
|
|
|
t = kzalloc(sizeof(*t) + sizeof(t->iphash[0]) * ip_list_hash_size,
|
|
GFP_KERNEL);
|
|
if (t == NULL) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
t->refcnt = 1;
|
|
strcpy(t->name, info->name);
|
|
INIT_LIST_HEAD(&t->lru_list);
|
|
for (i = 0; i < ip_list_hash_size; i++)
|
|
INIT_LIST_HEAD(&t->iphash[i]);
|
|
#ifdef CONFIG_PROC_FS
|
|
pde = proc_create_data(t->name, ip_list_perms, recent_net->xt_recent,
|
|
&recent_mt_fops, t);
|
|
if (pde == NULL) {
|
|
kfree(t);
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
pde->uid = ip_list_uid;
|
|
pde->gid = ip_list_gid;
|
|
#endif
|
|
spin_lock_bh(&recent_lock);
|
|
list_add_tail(&t->list, &recent_net->tables);
|
|
spin_unlock_bh(&recent_lock);
|
|
ret = 0;
|
|
out:
|
|
mutex_unlock(&recent_mutex);
|
|
return ret;
|
|
}
|
|
|
|
static void recent_mt_destroy(const struct xt_mtdtor_param *par)
|
|
{
|
|
struct recent_net *recent_net = recent_pernet(par->net);
|
|
const struct xt_recent_mtinfo *info = par->matchinfo;
|
|
struct recent_table *t;
|
|
|
|
mutex_lock(&recent_mutex);
|
|
t = recent_table_lookup(recent_net, info->name);
|
|
if (--t->refcnt == 0) {
|
|
spin_lock_bh(&recent_lock);
|
|
list_del(&t->list);
|
|
spin_unlock_bh(&recent_lock);
|
|
#ifdef CONFIG_PROC_FS
|
|
remove_proc_entry(t->name, recent_net->xt_recent);
|
|
#endif
|
|
recent_table_flush(t);
|
|
kfree(t);
|
|
}
|
|
mutex_unlock(&recent_mutex);
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
struct recent_iter_state {
|
|
const struct recent_table *table;
|
|
unsigned int bucket;
|
|
};
|
|
|
|
static void *recent_seq_start(struct seq_file *seq, loff_t *pos)
|
|
__acquires(recent_lock)
|
|
{
|
|
struct recent_iter_state *st = seq->private;
|
|
const struct recent_table *t = st->table;
|
|
struct recent_entry *e;
|
|
loff_t p = *pos;
|
|
|
|
spin_lock_bh(&recent_lock);
|
|
|
|
for (st->bucket = 0; st->bucket < ip_list_hash_size; st->bucket++)
|
|
list_for_each_entry(e, &t->iphash[st->bucket], list)
|
|
if (p-- == 0)
|
|
return e;
|
|
return NULL;
|
|
}
|
|
|
|
static void *recent_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
|
{
|
|
struct recent_iter_state *st = seq->private;
|
|
const struct recent_table *t = st->table;
|
|
const struct recent_entry *e = v;
|
|
const struct list_head *head = e->list.next;
|
|
|
|
while (head == &t->iphash[st->bucket]) {
|
|
if (++st->bucket >= ip_list_hash_size)
|
|
return NULL;
|
|
head = t->iphash[st->bucket].next;
|
|
}
|
|
(*pos)++;
|
|
return list_entry(head, struct recent_entry, list);
|
|
}
|
|
|
|
static void recent_seq_stop(struct seq_file *s, void *v)
|
|
__releases(recent_lock)
|
|
{
|
|
spin_unlock_bh(&recent_lock);
|
|
}
|
|
|
|
static int recent_seq_show(struct seq_file *seq, void *v)
|
|
{
|
|
const struct recent_entry *e = v;
|
|
unsigned int i;
|
|
|
|
i = (e->index - 1) % ip_pkt_list_tot;
|
|
if (e->family == NFPROTO_IPV4)
|
|
seq_printf(seq, "src=%pI4 ttl: %u last_seen: %lu oldest_pkt: %u",
|
|
&e->addr.ip, e->ttl, e->stamps[i], e->index);
|
|
else
|
|
seq_printf(seq, "src=%pI6 ttl: %u last_seen: %lu oldest_pkt: %u",
|
|
&e->addr.in6, e->ttl, e->stamps[i], e->index);
|
|
for (i = 0; i < e->nstamps; i++)
|
|
seq_printf(seq, "%s %lu", i ? "," : "", e->stamps[i]);
|
|
seq_printf(seq, "\n");
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations recent_seq_ops = {
|
|
.start = recent_seq_start,
|
|
.next = recent_seq_next,
|
|
.stop = recent_seq_stop,
|
|
.show = recent_seq_show,
|
|
};
|
|
|
|
static int recent_seq_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct proc_dir_entry *pde = PDE(inode);
|
|
struct recent_iter_state *st;
|
|
|
|
st = __seq_open_private(file, &recent_seq_ops, sizeof(*st));
|
|
if (st == NULL)
|
|
return -ENOMEM;
|
|
|
|
st->table = pde->data;
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t
|
|
recent_mt_proc_write(struct file *file, const char __user *input,
|
|
size_t size, loff_t *loff)
|
|
{
|
|
const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
|
|
struct recent_table *t = pde->data;
|
|
struct recent_entry *e;
|
|
char buf[sizeof("+b335:1d35:1e55:dead:c0de:1715:5afe:c0de")];
|
|
const char *c = buf;
|
|
union nf_inet_addr addr = {};
|
|
u_int16_t family;
|
|
bool add, succ;
|
|
|
|
if (size == 0)
|
|
return 0;
|
|
if (size > sizeof(buf))
|
|
size = sizeof(buf);
|
|
if (copy_from_user(buf, input, size) != 0)
|
|
return -EFAULT;
|
|
|
|
/* Strict protocol! */
|
|
if (*loff != 0)
|
|
return -ESPIPE;
|
|
switch (*c) {
|
|
case '/': /* flush table */
|
|
spin_lock_bh(&recent_lock);
|
|
recent_table_flush(t);
|
|
spin_unlock_bh(&recent_lock);
|
|
return size;
|
|
case '-': /* remove address */
|
|
add = false;
|
|
break;
|
|
case '+': /* add address */
|
|
add = true;
|
|
break;
|
|
default:
|
|
pr_info("Need \"+ip\", \"-ip\" or \"/\"\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
++c;
|
|
--size;
|
|
if (strnchr(c, size, ':') != NULL) {
|
|
family = NFPROTO_IPV6;
|
|
succ = in6_pton(c, size, (void *)&addr, '\n', NULL);
|
|
} else {
|
|
family = NFPROTO_IPV4;
|
|
succ = in4_pton(c, size, (void *)&addr, '\n', NULL);
|
|
}
|
|
|
|
if (!succ) {
|
|
pr_info("illegal address written to procfs\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
spin_lock_bh(&recent_lock);
|
|
e = recent_entry_lookup(t, &addr, family, 0);
|
|
if (e == NULL) {
|
|
if (add)
|
|
recent_entry_init(t, &addr, family, 0);
|
|
} else {
|
|
if (add)
|
|
recent_entry_update(t, e);
|
|
else
|
|
recent_entry_remove(t, e);
|
|
}
|
|
spin_unlock_bh(&recent_lock);
|
|
/* Note we removed one above */
|
|
*loff += size + 1;
|
|
return size + 1;
|
|
}
|
|
|
|
static const struct file_operations recent_mt_fops = {
|
|
.open = recent_seq_open,
|
|
.read = seq_read,
|
|
.write = recent_mt_proc_write,
|
|
.release = seq_release_private,
|
|
.owner = THIS_MODULE,
|
|
.llseek = seq_lseek,
|
|
};
|
|
|
|
static int __net_init recent_proc_net_init(struct net *net)
|
|
{
|
|
struct recent_net *recent_net = recent_pernet(net);
|
|
|
|
recent_net->xt_recent = proc_mkdir("xt_recent", net->proc_net);
|
|
if (!recent_net->xt_recent)
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
|
|
static void __net_exit recent_proc_net_exit(struct net *net)
|
|
{
|
|
proc_net_remove(net, "xt_recent");
|
|
}
|
|
#else
|
|
static inline int recent_proc_net_init(struct net *net)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void recent_proc_net_exit(struct net *net)
|
|
{
|
|
}
|
|
#endif /* CONFIG_PROC_FS */
|
|
|
|
static int __net_init recent_net_init(struct net *net)
|
|
{
|
|
struct recent_net *recent_net = recent_pernet(net);
|
|
|
|
INIT_LIST_HEAD(&recent_net->tables);
|
|
return recent_proc_net_init(net);
|
|
}
|
|
|
|
static void __net_exit recent_net_exit(struct net *net)
|
|
{
|
|
struct recent_net *recent_net = recent_pernet(net);
|
|
|
|
BUG_ON(!list_empty(&recent_net->tables));
|
|
recent_proc_net_exit(net);
|
|
}
|
|
|
|
static struct pernet_operations recent_net_ops = {
|
|
.init = recent_net_init,
|
|
.exit = recent_net_exit,
|
|
.id = &recent_net_id,
|
|
.size = sizeof(struct recent_net),
|
|
};
|
|
|
|
static struct xt_match recent_mt_reg[] __read_mostly = {
|
|
{
|
|
.name = "recent",
|
|
.revision = 0,
|
|
.family = NFPROTO_IPV4,
|
|
.match = recent_mt,
|
|
.matchsize = sizeof(struct xt_recent_mtinfo),
|
|
.checkentry = recent_mt_check,
|
|
.destroy = recent_mt_destroy,
|
|
.me = THIS_MODULE,
|
|
},
|
|
{
|
|
.name = "recent",
|
|
.revision = 0,
|
|
.family = NFPROTO_IPV6,
|
|
.match = recent_mt,
|
|
.matchsize = sizeof(struct xt_recent_mtinfo),
|
|
.checkentry = recent_mt_check,
|
|
.destroy = recent_mt_destroy,
|
|
.me = THIS_MODULE,
|
|
},
|
|
};
|
|
|
|
static int __init recent_mt_init(void)
|
|
{
|
|
int err;
|
|
|
|
if (!ip_list_tot || !ip_pkt_list_tot || ip_pkt_list_tot > 255)
|
|
return -EINVAL;
|
|
ip_list_hash_size = 1 << fls(ip_list_tot);
|
|
|
|
err = register_pernet_subsys(&recent_net_ops);
|
|
if (err)
|
|
return err;
|
|
err = xt_register_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
|
|
if (err)
|
|
unregister_pernet_subsys(&recent_net_ops);
|
|
return err;
|
|
}
|
|
|
|
static void __exit recent_mt_exit(void)
|
|
{
|
|
xt_unregister_matches(recent_mt_reg, ARRAY_SIZE(recent_mt_reg));
|
|
unregister_pernet_subsys(&recent_net_ops);
|
|
}
|
|
|
|
module_init(recent_mt_init);
|
|
module_exit(recent_mt_exit);
|