cregit-Linux how code gets into the kernel

Release 4.8 net/core/fib_rules.c

Directory: net/core
/*
 * net/core/fib_rules.c         Generic Routing Rules
 *
 *      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, version 2.
 *
 * Authors:     Thomas Graf <tgraf@suug.ch>
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/module.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/fib_rules.h>
#include <net/ip_tunnels.h>


int fib_default_rule_add(struct fib_rules_ops *ops, u32 pref, u32 table, u32 flags) { struct fib_rule *r; r = kzalloc(ops->rule_size, GFP_KERNEL); if (r == NULL) return -ENOMEM; atomic_set(&r->refcnt, 1); r->action = FR_ACT_TO_TBL; r->pref = pref; r->table = table; r->flags = flags; r->fr_net = ops->fro_net; r->suppress_prefixlen = -1; r->suppress_ifgroup = -1; /* The lock is not required here, the list in unreacheable * at the moment this function is called */ list_add_tail(&r->list, &ops->rules_list); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
denis v. lunevdenis v. lunev10488.14%266.67%
stefan tomanekstefan tomanek1411.86%133.33%
Total118100.00%3100.00%

EXPORT_SYMBOL(fib_default_rule_add);
static u32 fib_default_rule_pref(struct fib_rules_ops *ops) { struct list_head *pos; struct fib_rule *rule; if (!list_empty(&ops->rules_list)) { pos = ops->rules_list.next; if (pos->next != &ops->rules_list) { rule = list_entry(pos->next, struct fib_rule, list); if (rule->pref) return rule->pref - 1; } } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
patrick mchardypatrick mchardy8498.82%150.00%
phil sutterphil sutter11.18%150.00%
Total85100.00%2100.00%

static void notify_rule_change(int event, struct fib_rule *rule, struct fib_rules_ops *ops, struct nlmsghdr *nlh, u32 pid);
static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family) { struct fib_rules_ops *ops; rcu_read_lock(); list_for_each_entry_rcu(ops, &net->rules_ops, list) { if (ops->family == family) { if (!try_module_get(ops->owner)) ops = NULL; rcu_read_unlock(); return ops; } } rcu_read_unlock(); return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf6491.43%150.00%
denis v. lunevdenis v. lunev68.57%150.00%
Total70100.00%2100.00%


static void rules_ops_put(struct fib_rules_ops *ops) { if (ops) module_put(ops->owner); }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf22100.00%1100.00%
Total22100.00%1100.00%


static void flush_route_cache(struct fib_rules_ops *ops) { if (ops->flush_cache) ops->flush_cache(ops); }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf2187.50%150.00%
denis v. lunevdenis v. lunev312.50%150.00%
Total24100.00%2100.00%


static int __fib_rules_register(struct fib_rules_ops *ops) { int err = -EEXIST; struct fib_rules_ops *o; struct net *net; net = ops->fro_net; if (ops->rule_size < sizeof(struct fib_rule)) return -EINVAL; if (ops->match == NULL || ops->configure == NULL || ops->compare == NULL || ops->fill == NULL || ops->action == NULL) return -EINVAL; spin_lock(&net->rules_mod_lock); list_for_each_entry(o, &net->rules_ops, list) if (ops->family == o->family) goto errout; list_add_tail_rcu(&ops->list, &net->rules_ops); err = 0; errout: spin_unlock(&net->rules_mod_lock); return err; }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf12486.11%125.00%
denis v. lunevdenis v. lunev1812.50%250.00%
eric w. biedermaneric w. biederman21.39%125.00%
Total144100.00%4100.00%


struct fib_rules_ops * fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net) { struct fib_rules_ops *ops; int err; ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL); if (ops == NULL) return ERR_PTR(-ENOMEM); INIT_LIST_HEAD(&ops->rules_list); ops->fro_net = net; err = __fib_rules_register(ops); if (err) { kfree(ops); ops = ERR_PTR(err); } return ops; }

Contributors

PersonTokensPropCommitsCommitProp
eric w. biedermaneric w. biederman9598.96%150.00%
patrick mchardypatrick mchardy11.04%150.00%
Total96100.00%2100.00%

EXPORT_SYMBOL_GPL(fib_rules_register);
static void fib_rules_cleanup_ops(struct fib_rules_ops *ops) { struct fib_rule *rule, *tmp; list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) { list_del_rcu(&rule->list); if (ops->delete) ops->delete(rule); fib_rule_put(rule); } }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf4171.93%120.00%
david s. millerdavid s. miller1322.81%120.00%
denis v. lunevdenis v. lunev11.75%120.00%
stephen hemmingerstephen hemminger11.75%120.00%
daniel lezcanodaniel lezcano11.75%120.00%
Total57100.00%5100.00%


void fib_rules_unregister(struct fib_rules_ops *ops) { struct net *net = ops->fro_net; spin_lock(&net->rules_mod_lock); list_del_rcu(&ops->list); spin_unlock(&net->rules_mod_lock); fib_rules_cleanup_ops(ops); kfree_rcu(ops, rcu); }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf2850.91%114.29%
denis v. lunevdenis v. lunev1832.73%342.86%
americo wangamerico wang59.09%114.29%
eric w. biedermaneric w. biederman47.27%228.57%
Total55100.00%7100.00%

EXPORT_SYMBOL_GPL(fib_rules_unregister);
static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops, struct flowi *fl, int flags, struct fib_lookup_arg *arg) { int ret = 0; if (rule->iifindex && (rule->iifindex != fl->flowi_iif)) goto out; if (rule->oifindex && (rule->oifindex != fl->flowi_oif)) goto out; if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask) goto out; if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id)) goto out; if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg)) goto out; ret = ops->match(rule, fl, flags); out: return (rule->flags & FIB_RULE_INVERT) ? !ret : ret; }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf11369.75%450.00%
david aherndavid ahern2616.05%112.50%
patrick mchardypatrick mchardy2012.35%225.00%
david s. millerdavid s. miller31.85%112.50%
Total162100.00%8100.00%


int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl, int flags, struct fib_lookup_arg *arg) { struct fib_rule *rule; int err; rcu_read_lock(); list_for_each_entry_rcu(rule, &ops->rules_list, list) { jumped: if (!fib_rule_match(rule, ops, fl, flags, arg)) continue; if (rule->action == FR_ACT_GOTO) { struct fib_rule *target; target = rcu_dereference(rule->ctarget); if (target == NULL) { continue; } else { rule = target; goto jumped; } } else if (rule->action == FR_ACT_NOP) continue; else err = ops->action(rule, fl, flags, arg); if (!err && ops->suppress && ops->suppress(rule, arg)) continue; if (err != -EAGAIN) { if ((arg->flags & FIB_LOOKUP_NOREF) || likely(atomic_inc_not_zero(&rule->refcnt))) { arg->rule = rule; goto out; } break; } } err = -ESRCH; out: rcu_read_unlock(); return err; }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf16278.64%440.00%
eric dumazeteric dumazet2110.19%220.00%
stefan tomanekstefan tomanek199.22%110.00%
david aherndavid ahern20.97%110.00%
denis v. lunevdenis v. lunev10.49%110.00%
steven whitehousesteven whitehouse10.49%110.00%
Total206100.00%10100.00%

EXPORT_SYMBOL_GPL(fib_rules_lookup);
static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb, struct fib_rules_ops *ops) { int err = -EINVAL; if (frh->src_len) if (tb[FRA_SRC] == NULL || frh->src_len > (ops->addr_size * 8) || nla_len(tb[FRA_SRC]) != ops->addr_size) goto errout; if (frh->dst_len) if (tb[FRA_DST] == NULL || frh->dst_len > (ops->addr_size * 8) || nla_len(tb[FRA_DST]) != ops->addr_size) goto errout; err = 0; errout: return err; }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf121100.00%1100.00%
Total121100.00%1100.00%


static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh, struct nlattr **tb, struct fib_rule *rule) { struct fib_rule *r; list_for_each_entry(r, &ops->rules_list, list) { if (r->action != rule->action) continue; if (r->table != rule->table) continue; if (r->pref != rule->pref) continue; if (memcmp(r->iifname, rule->iifname, IFNAMSIZ)) continue; if (memcmp(r->oifname, rule->oifname, IFNAMSIZ)) continue; if (r->mark != rule->mark) continue; if (r->mark_mask != rule->mark_mask) continue; if (r->tun_id != rule->tun_id) continue; if (r->fr_net != rule->fr_net) continue; if (r->l3mdev != rule->l3mdev) continue; if (!ops->compare(r, frh, tb)) continue; return 1; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
mateusz bajorskimateusz bajorski183100.00%1100.00%
Total183100.00%1100.00%


int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh) { struct net *net = sock_net(skb->sk); struct fib_rule_hdr *frh = nlmsg_data(nlh); struct fib_rules_ops *ops = NULL; struct fib_rule *rule, *r, *last = NULL; struct nlattr *tb[FRA_MAX+1]; int err = -EINVAL, unresolved = 0; if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) goto errout; ops = lookup_rules_ops(net, frh->family); if (ops == NULL) { err = -EAFNOSUPPORT; goto errout; } err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy); if (err < 0) goto errout; err = validate_rulemsg(frh, tb, ops); if (err < 0) goto errout; rule = kzalloc(ops->rule_size, GFP_KERNEL); if (rule == NULL) { err = -ENOMEM; goto errout; } rule->fr_net = net; rule->pref = tb[FRA_PRIORITY] ? nla_get_u32(tb[FRA_PRIORITY]) : fib_default_rule_pref(ops); if (tb[FRA_IIFNAME]) { struct net_device *dev; rule->iifindex = -1; nla_strlcpy(rule->iifname, tb[FRA_IIFNAME], IFNAMSIZ); dev = __dev_get_by_name(net, rule->iifname); if (dev) rule->iifindex = dev->ifindex; } if (tb[FRA_OIFNAME]) { struct net_device *dev; rule->oifindex = -1; nla_strlcpy(rule->oifname, tb[FRA_OIFNAME], IFNAMSIZ); dev = __dev_get_by_name(net, rule->oifname); if (dev) rule->oifindex = dev->ifindex; } if (tb[FRA_FWMARK]) { rule->mark = nla_get_u32(tb[FRA_FWMARK]); if (rule->mark) /* compatibility: if the mark value is non-zero all bits * are compared unless a mask is explicitly specified. */ rule->mark_mask = 0xFFFFFFFF; } if (tb[FRA_FWMASK]) rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]); if (tb[FRA_TUN_ID]) rule->tun_id = nla_get_be64(tb[FRA_TUN_ID]); if (tb[FRA_L3MDEV]) { #ifdef CONFIG_NET_L3_MASTER_DEV rule->l3mdev = nla_get_u8(tb[FRA_L3MDEV]); if (rule->l3mdev != 1) #endif goto errout_free; } rule->action = frh->action; rule->flags = frh->flags; rule->table = frh_get_table(frh, tb); if (tb[FRA_SUPPRESS_PREFIXLEN]) rule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]); else rule->suppress_prefixlen = -1; if (tb[FRA_SUPPRESS_IFGROUP]) rule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]); else rule->suppress_ifgroup = -1; err = -EINVAL; if (tb[FRA_GOTO]) { if (rule->action != FR_ACT_GOTO) goto errout_free; rule->target = nla_get_u32(tb[FRA_GOTO]); /* Backward jumps are prohibited to avoid endless loops */ if (rule->target <= rule->pref) goto errout_free; list_for_each_entry(r, &ops->rules_list, list) { if (r->pref == rule->target) { RCU_INIT_POINTER(rule->ctarget, r); break; } } if (rcu_dereference_protected(rule->ctarget, 1) == NULL) unresolved = 1; } else if (rule->action == FR_ACT_GOTO) goto errout_free; if (rule->l3mdev && rule->table) goto errout_free; if ((nlh->nlmsg_flags & NLM_F_EXCL) && rule_exists(ops, frh, tb, rule)) { err = -EEXIST; goto errout_free; } err = ops->configure(rule, skb, frh, tb); if (err < 0) goto errout_free; list_for_each_entry(r, &ops->rules_list, list) { if (r->pref > rule->pref) break; last = r; } fib_rule_get(rule); if (last) list_add_rcu(&rule->list, &last->list); else list_add_rcu(&rule->list, &ops->rules_list); if (ops->unresolved_rules) { /* * There are unresolved goto rules in the list, check if * any of them are pointing to this new rule. */ list_for_each_entry(r, &ops->rules_list, list) { if (r->action == FR_ACT_GOTO && r->target == rule->pref && rtnl_dereference(r->ctarget) == NULL) { rcu_assign_pointer(r->ctarget, rule); if (--ops->unresolved_rules == 0) break; } } } if (rule->action == FR_ACT_GOTO) ops->nr_goto_rules++; if (unresolved) ops->unresolved_rules++; if (rule->tun_id) ip_tunnel_need_metadata(); notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid); flush_route_cache(ops); rules_ops_put(ops); return 0; errout_free: kfree(rule); errout: rules_ops_put(ops); return err; }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf63268.85%829.63%
patrick mchardypatrick mchardy707.63%414.81%
stefan tomanekstefan tomanek525.66%311.11%
david aherndavid ahern505.45%13.70%
eric dumazeteric dumazet434.68%27.41%
mateusz bajorskimateusz bajorski313.38%13.70%
eric w. biedermaneric w. biederman121.31%27.41%
denis v. lunevdenis v. lunev111.20%311.11%
phil sutterphil sutter101.09%13.70%
gao fenggao feng40.44%13.70%
hideaki yoshifujihideaki yoshifuji30.33%13.70%
Total918100.00%27100.00%

EXPORT_SYMBOL_GPL(fib_nl_newrule);
int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh) { struct net *net = sock_net(skb->sk); struct fib_rule_hdr *frh = nlmsg_data(nlh); struct fib_rules_ops *ops = NULL; struct fib_rule *rule, *tmp; struct nlattr *tb[FRA_MAX+1]; int err = -EINVAL; if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) goto errout; ops = lookup_rules_ops(net, frh->family); if (ops == NULL) { err = -EAFNOSUPPORT; goto errout; } err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy); if (err < 0) goto errout; err = validate_rulemsg(frh, tb, ops); if (err < 0) goto errout; list_for_each_entry(rule, &ops->rules_list, list) { if (frh->action && (frh->action != rule->action)) continue; if (frh_get_table(frh, tb) && (frh_get_table(frh, tb) != rule->table)) continue; if (tb[FRA_PRIORITY] && (rule->pref != nla_get_u32(tb[FRA_PRIORITY]))) continue; if (tb[FRA_IIFNAME] && nla_strcmp(tb[FRA_IIFNAME], rule->iifname)) continue; if (tb[FRA_OIFNAME] && nla_strcmp(tb[FRA_OIFNAME], rule->oifname)) continue; if (tb[FRA_FWMARK] && (rule->mark != nla_get_u32(tb[FRA_FWMARK]))) continue; if (tb[FRA_FWMASK] && (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK]))) continue; if (tb[FRA_TUN_ID] && (rule->tun_id != nla_get_be64(tb[FRA_TUN_ID]))) continue; if (tb[FRA_L3MDEV] && (rule->l3mdev != nla_get_u8(tb[FRA_L3MDEV]))) continue; if (!ops->compare(rule, frh, tb)) continue; if (rule->flags & FIB_RULE_PERMANENT) { err = -EPERM; goto errout; } if (ops->delete) { err = ops->delete(rule); if (err) goto errout; } if (rule->tun_id) ip_tunnel_unneed_metadata(); list_del_rcu(&rule->list); if (rule->action == FR_ACT_GOTO) { ops->nr_goto_rules--; if (rtnl_dereference(rule->ctarget) == NULL) ops->unresolved_rules--; } /* * Check if this rule is a target to any of them. If so, * disable them. As this operation is eventually very * expensive, it is only performed if goto rules have * actually been added. */ if (ops->nr_goto_rules > 0) { list_for_each_entry(tmp, &ops->rules_list, list) { if (rtnl_dereference(tmp->ctarget) == rule) { RCU_INIT_POINTER(tmp->ctarget, NULL); ops->unresolved_rules++; } } } notify_rule_change(RTM_DELRULE, rule, ops, nlh, NETLINK_CB(skb).portid); fib_rule_put(rule); flush_route_cache(ops); rules_ops_put(ops); return 0; } err = -ENOENT; errout: rules_ops_put(ops); return err; }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf44879.01%731.82%
patrick mchardypatrick mchardy295.11%418.18%
alexander duyckalexander duyck244.23%14.55%
david aherndavid ahern223.88%14.55%
zheng yanzheng yan183.17%14.55%
denis v. lunevdenis v. lunev132.29%313.64%
andreas henrikssonandreas henriksson50.88%14.55%
hideaki yoshifujihideaki yoshifuji30.53%14.55%
eric dumazeteric dumazet30.53%14.55%
eric w. biedermaneric w. biederman10.18%14.55%
stephen hemmingerstephen hemminger10.18%14.55%
Total567100.00%22100.00%

EXPORT_SYMBOL_GPL(fib_nl_delrule);
static inline size_t fib_rule_nlmsg_size(struct