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