From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- net/ipv4/fib_rules.c | 436 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 436 insertions(+) create mode 100644 net/ipv4/fib_rules.c (limited to 'net/ipv4/fib_rules.c') diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c new file mode 100644 index 0000000000..513f475c6a --- /dev/null +++ b/net/ipv4/fib_rules.c @@ -0,0 +1,436 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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. + * + * Authors: Alexey Kuznetsov, + * Thomas Graf + * + * Fixes: + * Rani Assaf : local_rule cannot be deleted + * Marc Boucher : routing by fwmark + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct fib4_rule { + struct fib_rule common; + u8 dst_len; + u8 src_len; + dscp_t dscp; + __be32 src; + __be32 srcmask; + __be32 dst; + __be32 dstmask; +#ifdef CONFIG_IP_ROUTE_CLASSID + u32 tclassid; +#endif +}; + +static bool fib4_rule_matchall(const struct fib_rule *rule) +{ + struct fib4_rule *r = container_of(rule, struct fib4_rule, common); + + if (r->dst_len || r->src_len || r->dscp) + return false; + return fib_rule_matchall(rule); +} + +bool fib4_rule_default(const struct fib_rule *rule) +{ + if (!fib4_rule_matchall(rule) || rule->action != FR_ACT_TO_TBL || + rule->l3mdev) + return false; + if (rule->table != RT_TABLE_LOCAL && rule->table != RT_TABLE_MAIN && + rule->table != RT_TABLE_DEFAULT) + return false; + return true; +} +EXPORT_SYMBOL_GPL(fib4_rule_default); + +int fib4_rules_dump(struct net *net, struct notifier_block *nb, + struct netlink_ext_ack *extack) +{ + return fib_rules_dump(net, nb, AF_INET, extack); +} + +unsigned int fib4_rules_seq_read(struct net *net) +{ + return fib_rules_seq_read(net, AF_INET); +} + +int __fib_lookup(struct net *net, struct flowi4 *flp, + struct fib_result *res, unsigned int flags) +{ + struct fib_lookup_arg arg = { + .result = res, + .flags = flags, + }; + int err; + + /* update flow if oif or iif point to device enslaved to l3mdev */ + l3mdev_update_flow(net, flowi4_to_flowi(flp)); + + err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg); +#ifdef CONFIG_IP_ROUTE_CLASSID + if (arg.rule) + res->tclassid = ((struct fib4_rule *)arg.rule)->tclassid; + else + res->tclassid = 0; +#endif + + if (err == -ESRCH) + err = -ENETUNREACH; + + return err; +} +EXPORT_SYMBOL_GPL(__fib_lookup); + +INDIRECT_CALLABLE_SCOPE int fib4_rule_action(struct fib_rule *rule, + struct flowi *flp, int flags, + struct fib_lookup_arg *arg) +{ + int err = -EAGAIN; + struct fib_table *tbl; + u32 tb_id; + + switch (rule->action) { + case FR_ACT_TO_TBL: + break; + + case FR_ACT_UNREACHABLE: + return -ENETUNREACH; + + case FR_ACT_PROHIBIT: + return -EACCES; + + case FR_ACT_BLACKHOLE: + default: + return -EINVAL; + } + + rcu_read_lock(); + + tb_id = fib_rule_get_table(rule, arg); + tbl = fib_get_table(rule->fr_net, tb_id); + if (tbl) + err = fib_table_lookup(tbl, &flp->u.ip4, + (struct fib_result *)arg->result, + arg->flags); + + rcu_read_unlock(); + return err; +} + +INDIRECT_CALLABLE_SCOPE bool fib4_rule_suppress(struct fib_rule *rule, + int flags, + struct fib_lookup_arg *arg) +{ + struct fib_result *result = arg->result; + struct net_device *dev = NULL; + + if (result->fi) { + struct fib_nh_common *nhc = fib_info_nhc(result->fi, 0); + + dev = nhc->nhc_dev; + } + + /* do not accept result if the route does + * not meet the required prefix length + */ + if (result->prefixlen <= rule->suppress_prefixlen) + goto suppress_route; + + /* do not accept result if the route uses a device + * belonging to a forbidden interface group + */ + if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup) + goto suppress_route; + + return false; + +suppress_route: + if (!(arg->flags & FIB_LOOKUP_NOREF)) + fib_info_put(result->fi); + return true; +} + +INDIRECT_CALLABLE_SCOPE int fib4_rule_match(struct fib_rule *rule, + struct flowi *fl, int flags) +{ + struct fib4_rule *r = (struct fib4_rule *) rule; + struct flowi4 *fl4 = &fl->u.ip4; + __be32 daddr = fl4->daddr; + __be32 saddr = fl4->saddr; + + if (((saddr ^ r->src) & r->srcmask) || + ((daddr ^ r->dst) & r->dstmask)) + return 0; + + if (r->dscp && r->dscp != inet_dsfield_to_dscp(fl4->flowi4_tos)) + return 0; + + if (rule->ip_proto && (rule->ip_proto != fl4->flowi4_proto)) + return 0; + + if (fib_rule_port_range_set(&rule->sport_range) && + !fib_rule_port_inrange(&rule->sport_range, fl4->fl4_sport)) + return 0; + + if (fib_rule_port_range_set(&rule->dport_range) && + !fib_rule_port_inrange(&rule->dport_range, fl4->fl4_dport)) + return 0; + + return 1; +} + +static struct fib_table *fib_empty_table(struct net *net) +{ + u32 id = 1; + + while (1) { + if (!fib_get_table(net, id)) + return fib_new_table(net, id); + + if (id++ == RT_TABLE_MAX) + break; + } + return NULL; +} + +static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb, + struct fib_rule_hdr *frh, + struct nlattr **tb, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(skb->sk); + int err = -EINVAL; + struct fib4_rule *rule4 = (struct fib4_rule *) rule; + + if (!inet_validate_dscp(frh->tos)) { + NL_SET_ERR_MSG(extack, + "Invalid dsfield (tos): ECN bits must be 0"); + goto errout; + } + /* IPv4 currently doesn't handle high order DSCP bits correctly */ + if (frh->tos & ~IPTOS_TOS_MASK) { + NL_SET_ERR_MSG(extack, "Invalid tos"); + goto errout; + } + rule4->dscp = inet_dsfield_to_dscp(frh->tos); + + /* split local/main if they are not already split */ + err = fib_unmerge(net); + if (err) + goto errout; + + if (rule->table == RT_TABLE_UNSPEC && !rule->l3mdev) { + if (rule->action == FR_ACT_TO_TBL) { + struct fib_table *table; + + table = fib_empty_table(net); + if (!table) { + err = -ENOBUFS; + goto errout; + } + + rule->table = table->tb_id; + } + } + + if (frh->src_len) + rule4->src = nla_get_in_addr(tb[FRA_SRC]); + + if (frh->dst_len) + rule4->dst = nla_get_in_addr(tb[FRA_DST]); + +#ifdef CONFIG_IP_ROUTE_CLASSID + if (tb[FRA_FLOW]) { + rule4->tclassid = nla_get_u32(tb[FRA_FLOW]); + if (rule4->tclassid) + atomic_inc(&net->ipv4.fib_num_tclassid_users); + } +#endif + + if (fib_rule_requires_fldissect(rule)) + net->ipv4.fib_rules_require_fldissect++; + + rule4->src_len = frh->src_len; + rule4->srcmask = inet_make_mask(rule4->src_len); + rule4->dst_len = frh->dst_len; + rule4->dstmask = inet_make_mask(rule4->dst_len); + + net->ipv4.fib_has_custom_rules = true; + + err = 0; +errout: + return err; +} + +static int fib4_rule_delete(struct fib_rule *rule) +{ + struct net *net = rule->fr_net; + int err; + + /* split local/main if they are not already split */ + err = fib_unmerge(net); + if (err) + goto errout; + +#ifdef CONFIG_IP_ROUTE_CLASSID + if (((struct fib4_rule *)rule)->tclassid) + atomic_dec(&net->ipv4.fib_num_tclassid_users); +#endif + net->ipv4.fib_has_custom_rules = true; + + if (net->ipv4.fib_rules_require_fldissect && + fib_rule_requires_fldissect(rule)) + net->ipv4.fib_rules_require_fldissect--; +errout: + return err; +} + +static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, + struct nlattr **tb) +{ + struct fib4_rule *rule4 = (struct fib4_rule *) rule; + + if (frh->src_len && (rule4->src_len != frh->src_len)) + return 0; + + if (frh->dst_len && (rule4->dst_len != frh->dst_len)) + return 0; + + if (frh->tos && inet_dscp_to_dsfield(rule4->dscp) != frh->tos) + return 0; + +#ifdef CONFIG_IP_ROUTE_CLASSID + if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW]))) + return 0; +#endif + + if (frh->src_len && (rule4->src != nla_get_in_addr(tb[FRA_SRC]))) + return 0; + + if (frh->dst_len && (rule4->dst != nla_get_in_addr(tb[FRA_DST]))) + return 0; + + return 1; +} + +static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb, + struct fib_rule_hdr *frh) +{ + struct fib4_rule *rule4 = (struct fib4_rule *) rule; + + frh->dst_len = rule4->dst_len; + frh->src_len = rule4->src_len; + frh->tos = inet_dscp_to_dsfield(rule4->dscp); + + if ((rule4->dst_len && + nla_put_in_addr(skb, FRA_DST, rule4->dst)) || + (rule4->src_len && + nla_put_in_addr(skb, FRA_SRC, rule4->src))) + goto nla_put_failure; +#ifdef CONFIG_IP_ROUTE_CLASSID + if (rule4->tclassid && + nla_put_u32(skb, FRA_FLOW, rule4->tclassid)) + goto nla_put_failure; +#endif + return 0; + +nla_put_failure: + return -ENOBUFS; +} + +static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule) +{ + return nla_total_size(4) /* dst */ + + nla_total_size(4) /* src */ + + nla_total_size(4); /* flow */ +} + +static void fib4_rule_flush_cache(struct fib_rules_ops *ops) +{ + rt_cache_flush(ops->fro_net); +} + +static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = { + .family = AF_INET, + .rule_size = sizeof(struct fib4_rule), + .addr_size = sizeof(u32), + .action = fib4_rule_action, + .suppress = fib4_rule_suppress, + .match = fib4_rule_match, + .configure = fib4_rule_configure, + .delete = fib4_rule_delete, + .compare = fib4_rule_compare, + .fill = fib4_rule_fill, + .nlmsg_payload = fib4_rule_nlmsg_payload, + .flush_cache = fib4_rule_flush_cache, + .nlgroup = RTNLGRP_IPV4_RULE, + .owner = THIS_MODULE, +}; + +static int fib_default_rules_init(struct fib_rules_ops *ops) +{ + int err; + + err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0); + if (err < 0) + return err; + err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0); + if (err < 0) + return err; + err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0); + if (err < 0) + return err; + return 0; +} + +int __net_init fib4_rules_init(struct net *net) +{ + int err; + struct fib_rules_ops *ops; + + ops = fib_rules_register(&fib4_rules_ops_template, net); + if (IS_ERR(ops)) + return PTR_ERR(ops); + + err = fib_default_rules_init(ops); + if (err < 0) + goto fail; + net->ipv4.rules_ops = ops; + net->ipv4.fib_has_custom_rules = false; + net->ipv4.fib_rules_require_fldissect = 0; + return 0; + +fail: + /* also cleans all rules already added */ + fib_rules_unregister(ops); + return err; +} + +void __net_exit fib4_rules_exit(struct net *net) +{ + fib_rules_unregister(net->ipv4.rules_ops); +} -- cgit v1.2.3