440 lines
11 KiB
C
440 lines
11 KiB
C
/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* IPv4 Forwarding Information Base: policy rules.
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*
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* Version: $Id: fib_rules.c,v 1.17 2001/10/31 21:55:54 davem Exp $
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*
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* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Fixes:
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* Rani Assaf : local_rule cannot be deleted
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* Marc Boucher : routing by fwmark
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*/
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#include <linux/config.h>
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#include <asm/uaccess.h>
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#include <asm/system.h>
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#include <linux/bitops.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/string.h>
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#include <linux/socket.h>
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#include <linux/sockios.h>
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#include <linux/errno.h>
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#include <linux/in.h>
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#include <linux/inet.h>
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#include <linux/inetdevice.h>
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#include <linux/netdevice.h>
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#include <linux/if_arp.h>
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#include <linux/proc_fs.h>
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#include <linux/skbuff.h>
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#include <linux/netlink.h>
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#include <linux/init.h>
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#include <net/ip.h>
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#include <net/protocol.h>
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#include <net/route.h>
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#include <net/tcp.h>
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#include <net/sock.h>
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#include <net/ip_fib.h>
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#define FRprintk(a...)
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struct fib_rule
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{
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struct fib_rule *r_next;
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atomic_t r_clntref;
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u32 r_preference;
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unsigned char r_table;
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unsigned char r_action;
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unsigned char r_dst_len;
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unsigned char r_src_len;
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u32 r_src;
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u32 r_srcmask;
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u32 r_dst;
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u32 r_dstmask;
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u32 r_srcmap;
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u8 r_flags;
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u8 r_tos;
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#ifdef CONFIG_IP_ROUTE_FWMARK
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u32 r_fwmark;
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#endif
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int r_ifindex;
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#ifdef CONFIG_NET_CLS_ROUTE
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__u32 r_tclassid;
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#endif
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char r_ifname[IFNAMSIZ];
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int r_dead;
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};
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static struct fib_rule default_rule = {
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.r_clntref = ATOMIC_INIT(2),
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.r_preference = 0x7FFF,
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.r_table = RT_TABLE_DEFAULT,
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.r_action = RTN_UNICAST,
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};
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static struct fib_rule main_rule = {
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.r_next = &default_rule,
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.r_clntref = ATOMIC_INIT(2),
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.r_preference = 0x7FFE,
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.r_table = RT_TABLE_MAIN,
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.r_action = RTN_UNICAST,
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};
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static struct fib_rule local_rule = {
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.r_next = &main_rule,
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.r_clntref = ATOMIC_INIT(2),
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.r_table = RT_TABLE_LOCAL,
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.r_action = RTN_UNICAST,
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};
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static struct fib_rule *fib_rules = &local_rule;
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static DEFINE_RWLOCK(fib_rules_lock);
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int inet_rtm_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
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{
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struct rtattr **rta = arg;
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struct rtmsg *rtm = NLMSG_DATA(nlh);
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struct fib_rule *r, **rp;
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int err = -ESRCH;
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for (rp=&fib_rules; (r=*rp) != NULL; rp=&r->r_next) {
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if ((!rta[RTA_SRC-1] || memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 4) == 0) &&
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rtm->rtm_src_len == r->r_src_len &&
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rtm->rtm_dst_len == r->r_dst_len &&
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(!rta[RTA_DST-1] || memcmp(RTA_DATA(rta[RTA_DST-1]), &r->r_dst, 4) == 0) &&
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rtm->rtm_tos == r->r_tos &&
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#ifdef CONFIG_IP_ROUTE_FWMARK
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(!rta[RTA_PROTOINFO-1] || memcmp(RTA_DATA(rta[RTA_PROTOINFO-1]), &r->r_fwmark, 4) == 0) &&
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#endif
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(!rtm->rtm_type || rtm->rtm_type == r->r_action) &&
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(!rta[RTA_PRIORITY-1] || memcmp(RTA_DATA(rta[RTA_PRIORITY-1]), &r->r_preference, 4) == 0) &&
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(!rta[RTA_IIF-1] || rtattr_strcmp(rta[RTA_IIF-1], r->r_ifname) == 0) &&
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(!rtm->rtm_table || (r && rtm->rtm_table == r->r_table))) {
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err = -EPERM;
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if (r == &local_rule)
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break;
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write_lock_bh(&fib_rules_lock);
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*rp = r->r_next;
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r->r_dead = 1;
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write_unlock_bh(&fib_rules_lock);
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fib_rule_put(r);
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err = 0;
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break;
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}
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}
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return err;
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}
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/* Allocate new unique table id */
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static struct fib_table *fib_empty_table(void)
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{
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int id;
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for (id = 1; id <= RT_TABLE_MAX; id++)
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if (fib_tables[id] == NULL)
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return __fib_new_table(id);
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return NULL;
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}
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void fib_rule_put(struct fib_rule *r)
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{
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if (atomic_dec_and_test(&r->r_clntref)) {
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if (r->r_dead)
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kfree(r);
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else
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printk("Freeing alive rule %p\n", r);
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}
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}
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int inet_rtm_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
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{
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struct rtattr **rta = arg;
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struct rtmsg *rtm = NLMSG_DATA(nlh);
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struct fib_rule *r, *new_r, **rp;
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unsigned char table_id;
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if (rtm->rtm_src_len > 32 || rtm->rtm_dst_len > 32 ||
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(rtm->rtm_tos & ~IPTOS_TOS_MASK))
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return -EINVAL;
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if (rta[RTA_IIF-1] && RTA_PAYLOAD(rta[RTA_IIF-1]) > IFNAMSIZ)
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return -EINVAL;
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table_id = rtm->rtm_table;
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if (table_id == RT_TABLE_UNSPEC) {
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struct fib_table *table;
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if (rtm->rtm_type == RTN_UNICAST) {
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if ((table = fib_empty_table()) == NULL)
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return -ENOBUFS;
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table_id = table->tb_id;
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}
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}
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new_r = kmalloc(sizeof(*new_r), GFP_KERNEL);
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if (!new_r)
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return -ENOMEM;
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memset(new_r, 0, sizeof(*new_r));
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if (rta[RTA_SRC-1])
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memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 4);
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if (rta[RTA_DST-1])
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memcpy(&new_r->r_dst, RTA_DATA(rta[RTA_DST-1]), 4);
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if (rta[RTA_GATEWAY-1])
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memcpy(&new_r->r_srcmap, RTA_DATA(rta[RTA_GATEWAY-1]), 4);
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new_r->r_src_len = rtm->rtm_src_len;
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new_r->r_dst_len = rtm->rtm_dst_len;
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new_r->r_srcmask = inet_make_mask(rtm->rtm_src_len);
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new_r->r_dstmask = inet_make_mask(rtm->rtm_dst_len);
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new_r->r_tos = rtm->rtm_tos;
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#ifdef CONFIG_IP_ROUTE_FWMARK
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if (rta[RTA_PROTOINFO-1])
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memcpy(&new_r->r_fwmark, RTA_DATA(rta[RTA_PROTOINFO-1]), 4);
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#endif
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new_r->r_action = rtm->rtm_type;
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new_r->r_flags = rtm->rtm_flags;
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if (rta[RTA_PRIORITY-1])
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memcpy(&new_r->r_preference, RTA_DATA(rta[RTA_PRIORITY-1]), 4);
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new_r->r_table = table_id;
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if (rta[RTA_IIF-1]) {
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struct net_device *dev;
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rtattr_strlcpy(new_r->r_ifname, rta[RTA_IIF-1], IFNAMSIZ);
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new_r->r_ifindex = -1;
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dev = __dev_get_by_name(new_r->r_ifname);
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if (dev)
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new_r->r_ifindex = dev->ifindex;
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}
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#ifdef CONFIG_NET_CLS_ROUTE
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if (rta[RTA_FLOW-1])
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memcpy(&new_r->r_tclassid, RTA_DATA(rta[RTA_FLOW-1]), 4);
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#endif
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rp = &fib_rules;
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if (!new_r->r_preference) {
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r = fib_rules;
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if (r && (r = r->r_next) != NULL) {
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rp = &fib_rules->r_next;
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if (r->r_preference)
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new_r->r_preference = r->r_preference - 1;
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}
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}
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while ( (r = *rp) != NULL ) {
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if (r->r_preference > new_r->r_preference)
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break;
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rp = &r->r_next;
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}
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new_r->r_next = r;
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atomic_inc(&new_r->r_clntref);
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write_lock_bh(&fib_rules_lock);
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*rp = new_r;
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write_unlock_bh(&fib_rules_lock);
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return 0;
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}
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#ifdef CONFIG_NET_CLS_ROUTE
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u32 fib_rules_tclass(struct fib_result *res)
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{
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if (res->r)
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return res->r->r_tclassid;
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return 0;
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}
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#endif
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static void fib_rules_detach(struct net_device *dev)
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{
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struct fib_rule *r;
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for (r=fib_rules; r; r=r->r_next) {
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if (r->r_ifindex == dev->ifindex) {
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write_lock_bh(&fib_rules_lock);
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r->r_ifindex = -1;
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write_unlock_bh(&fib_rules_lock);
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}
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}
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}
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static void fib_rules_attach(struct net_device *dev)
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{
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struct fib_rule *r;
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for (r=fib_rules; r; r=r->r_next) {
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if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0) {
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write_lock_bh(&fib_rules_lock);
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r->r_ifindex = dev->ifindex;
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write_unlock_bh(&fib_rules_lock);
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}
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}
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}
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int fib_lookup(const struct flowi *flp, struct fib_result *res)
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{
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int err;
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struct fib_rule *r, *policy;
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struct fib_table *tb;
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u32 daddr = flp->fl4_dst;
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u32 saddr = flp->fl4_src;
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FRprintk("Lookup: %u.%u.%u.%u <- %u.%u.%u.%u ",
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NIPQUAD(flp->fl4_dst), NIPQUAD(flp->fl4_src));
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read_lock(&fib_rules_lock);
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for (r = fib_rules; r; r=r->r_next) {
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if (((saddr^r->r_src) & r->r_srcmask) ||
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((daddr^r->r_dst) & r->r_dstmask) ||
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(r->r_tos && r->r_tos != flp->fl4_tos) ||
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#ifdef CONFIG_IP_ROUTE_FWMARK
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(r->r_fwmark && r->r_fwmark != flp->fl4_fwmark) ||
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#endif
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(r->r_ifindex && r->r_ifindex != flp->iif))
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continue;
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FRprintk("tb %d r %d ", r->r_table, r->r_action);
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switch (r->r_action) {
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case RTN_UNICAST:
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policy = r;
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break;
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case RTN_UNREACHABLE:
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read_unlock(&fib_rules_lock);
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return -ENETUNREACH;
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default:
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case RTN_BLACKHOLE:
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read_unlock(&fib_rules_lock);
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return -EINVAL;
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case RTN_PROHIBIT:
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read_unlock(&fib_rules_lock);
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return -EACCES;
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}
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if ((tb = fib_get_table(r->r_table)) == NULL)
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continue;
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err = tb->tb_lookup(tb, flp, res);
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if (err == 0) {
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res->r = policy;
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if (policy)
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atomic_inc(&policy->r_clntref);
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read_unlock(&fib_rules_lock);
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return 0;
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}
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if (err < 0 && err != -EAGAIN) {
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read_unlock(&fib_rules_lock);
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return err;
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}
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}
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FRprintk("FAILURE\n");
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read_unlock(&fib_rules_lock);
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return -ENETUNREACH;
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}
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void fib_select_default(const struct flowi *flp, struct fib_result *res)
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{
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if (res->r && res->r->r_action == RTN_UNICAST &&
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FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) {
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struct fib_table *tb;
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if ((tb = fib_get_table(res->r->r_table)) != NULL)
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tb->tb_select_default(tb, flp, res);
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}
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}
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static int fib_rules_event(struct notifier_block *this, unsigned long event, void *ptr)
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{
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struct net_device *dev = ptr;
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if (event == NETDEV_UNREGISTER)
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fib_rules_detach(dev);
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else if (event == NETDEV_REGISTER)
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fib_rules_attach(dev);
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return NOTIFY_DONE;
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}
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static struct notifier_block fib_rules_notifier = {
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.notifier_call =fib_rules_event,
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};
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static __inline__ int inet_fill_rule(struct sk_buff *skb,
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struct fib_rule *r,
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struct netlink_callback *cb,
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unsigned int flags)
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{
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struct rtmsg *rtm;
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struct nlmsghdr *nlh;
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unsigned char *b = skb->tail;
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nlh = NLMSG_NEW_ANSWER(skb, cb, RTM_NEWRULE, sizeof(*rtm), flags);
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rtm = NLMSG_DATA(nlh);
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rtm->rtm_family = AF_INET;
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rtm->rtm_dst_len = r->r_dst_len;
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rtm->rtm_src_len = r->r_src_len;
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rtm->rtm_tos = r->r_tos;
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#ifdef CONFIG_IP_ROUTE_FWMARK
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if (r->r_fwmark)
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RTA_PUT(skb, RTA_PROTOINFO, 4, &r->r_fwmark);
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#endif
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rtm->rtm_table = r->r_table;
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rtm->rtm_protocol = 0;
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rtm->rtm_scope = 0;
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rtm->rtm_type = r->r_action;
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rtm->rtm_flags = r->r_flags;
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if (r->r_dst_len)
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RTA_PUT(skb, RTA_DST, 4, &r->r_dst);
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if (r->r_src_len)
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RTA_PUT(skb, RTA_SRC, 4, &r->r_src);
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if (r->r_ifname[0])
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RTA_PUT(skb, RTA_IIF, IFNAMSIZ, &r->r_ifname);
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if (r->r_preference)
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RTA_PUT(skb, RTA_PRIORITY, 4, &r->r_preference);
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if (r->r_srcmap)
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RTA_PUT(skb, RTA_GATEWAY, 4, &r->r_srcmap);
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#ifdef CONFIG_NET_CLS_ROUTE
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if (r->r_tclassid)
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RTA_PUT(skb, RTA_FLOW, 4, &r->r_tclassid);
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#endif
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nlh->nlmsg_len = skb->tail - b;
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return skb->len;
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nlmsg_failure:
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rtattr_failure:
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skb_trim(skb, b - skb->data);
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return -1;
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}
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int inet_dump_rules(struct sk_buff *skb, struct netlink_callback *cb)
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{
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int idx;
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int s_idx = cb->args[0];
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struct fib_rule *r;
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read_lock(&fib_rules_lock);
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for (r=fib_rules, idx=0; r; r = r->r_next, idx++) {
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if (idx < s_idx)
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continue;
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if (inet_fill_rule(skb, r, cb, NLM_F_MULTI) < 0)
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break;
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}
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read_unlock(&fib_rules_lock);
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cb->args[0] = idx;
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return skb->len;
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}
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void __init fib_rules_init(void)
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{
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register_netdevice_notifier(&fib_rules_notifier);
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}
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