cregit-Linux how code gets into the kernel

Release 4.8 net/sched/cls_api.c

Directory: net/sched
/*
 * net/sched/cls_api.c  Packet classifier API.
 *
 *              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.
 *
 * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 * Changes:
 *
 * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
 *
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>

/* The list of all installed classifier types */
static LIST_HEAD(tcf_proto_base);

/* Protects list of registered TC modules. It is pure SMP lock. */
static DEFINE_RWLOCK(cls_mod_lock);

/* Find classifier type by string name */


static const struct tcf_proto_ops *tcf_proto_lookup_ops(struct nlattr *kind) { const struct tcf_proto_ops *t, *res = NULL; if (kind) { read_lock(&cls_mod_lock); list_for_each_entry(t, &tcf_proto_base, head) { if (nla_strcmp(kind, t->kind) == 0) { if (try_module_get(t->owner)) res = t; break; } } read_unlock(&cls_mod_lock); } return res; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git5362.35%225.00%
patrick mchardypatrick mchardy1517.65%225.00%
eric dumazeteric dumazet89.41%225.00%
americo wangamerico wang89.41%112.50%
chris wrightchris wright11.18%112.50%
Total85100.00%8100.00%

/* Register(unregister) new classifier type */
int register_tcf_proto_ops(struct tcf_proto_ops *ops) { struct tcf_proto_ops *t; int rc = -EEXIST; write_lock(&cls_mod_lock); list_for_each_entry(t, &tcf_proto_base, head) if (!strcmp(ops->kind, t->kind)) goto out; list_add_tail(&ops->head, &tcf_proto_base); rc = 0; out: write_unlock(&cls_mod_lock); return rc; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git4557.69%250.00%
arnaldo carvalho de meloarnaldo carvalho de melo1721.79%125.00%
americo wangamerico wang1620.51%125.00%
Total78100.00%4100.00%

EXPORT_SYMBOL(register_tcf_proto_ops);
int unregister_tcf_proto_ops(struct tcf_proto_ops *ops) { struct tcf_proto_ops *t; int rc = -ENOENT; /* Wait for outstanding call_rcu()s, if any, from a * tcf_proto_ops's destroy() handler. */ rcu_barrier(); write_lock(&cls_mod_lock); list_for_each_entry(t, &tcf_proto_base, head) { if (t == ops) { list_del(&t->head); rc = 0; break; } } write_unlock(&cls_mod_lock); return rc; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git3853.52%233.33%
americo wangamerico wang1318.31%116.67%
arnaldo carvalho de meloarnaldo carvalho de melo1115.49%116.67%
eric dumazeteric dumazet57.04%116.67%
daniel borkmanndaniel borkmann45.63%116.67%
Total71100.00%6100.00%

EXPORT_SYMBOL(unregister_tcf_proto_ops); static int tfilter_notify(struct net *net, struct sk_buff *oskb, struct nlmsghdr *n, struct tcf_proto *tp, unsigned long fh, int event);
static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb, struct nlmsghdr *n, struct tcf_proto __rcu **chain, int event) { struct tcf_proto __rcu **it_chain; struct tcf_proto *tp; for (it_chain = chain; (tp = rtnl_dereference(*it_chain)) != NULL; it_chain = &tp->next) tfilter_notify(net, oskb, n, tp, 0, event); }

Contributors

PersonTokensPropCommitsCommitProp
daniel borkmanndaniel borkmann83100.00%1100.00%
Total83100.00%1100.00%

/* Select new prio value from the range, managed by kernel. */
static inline u32 tcf_auto_prio(struct tcf_proto *tp) { u32 first = TC_H_MAKE(0xC0000000U, 0U); if (tp) first = tp->prio - 1; return first; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git3697.30%150.00%
stephen hemmingerstephen hemminger12.70%150.00%
Total37100.00%2100.00%

/* Add/change/delete/get a filter node */
static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n) { struct net *net = sock_net(skb->sk); struct nlattr *tca[TCA_MAX + 1]; struct tcmsg *t; u32 protocol; u32 prio; u32 nprio; u32 parent; struct net_device *dev; struct Qdisc *q; struct tcf_proto __rcu **back; struct tcf_proto __rcu **chain; struct tcf_proto *tp; const struct tcf_proto_ops *tp_ops; const struct Qdisc_class_ops *cops; unsigned long cl; unsigned long fh; int err; int tp_created = 0; if ((n->nlmsg_type != RTM_GETTFILTER) && !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) return -EPERM; replay: err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL); if (err < 0) return err; t = nlmsg_data(n); protocol = TC_H_MIN(t->tcm_info); prio = TC_H_MAJ(t->tcm_info); nprio = prio; parent = t->tcm_parent; cl = 0; if (prio == 0) { switch (n->nlmsg_type) { case RTM_DELTFILTER: if (protocol || t->tcm_handle || tca[TCA_KIND]) return -ENOENT; break; case RTM_NEWTFILTER: /* If no priority is provided by the user, * we allocate one. */ if (n->nlmsg_flags & NLM_F_CREATE) { prio = TC_H_MAKE(0x80000000U, 0U); break; } /* fall-through */ default: return -ENOENT; } } /* Find head of filter chain. */ /* Find link */ dev = __dev_get_by_index(net, t->tcm_ifindex); if (dev == NULL) return -ENODEV; /* Find qdisc */ if (!parent) { q = dev->qdisc; parent = q->handle; } else { q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent)); if (q == NULL) return -EINVAL; } /* Is it classful? */ cops = q->ops->cl_ops; if (!cops) return -EINVAL; if (cops->tcf_chain == NULL) return -EOPNOTSUPP; /* Do we search for filter, attached to class? */ if (TC_H_MIN(parent)) { cl = cops->get(q, parent); if (cl == 0) return -ENOENT; } /* And the last stroke */ chain = cops->tcf_chain(q, cl); err = -EINVAL; if (chain == NULL) goto errout; if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) { tfilter_notify_chain(net, skb, n, chain, RTM_DELTFILTER); tcf_destroy_chain(chain); err = 0; goto errout; } /* Check the chain for existence of proto-tcf with this priority */ for (back = chain; (tp = rtnl_dereference(*back)) != NULL; back = &tp->next) { if (tp->prio >= prio) { if (tp->prio == prio) { if (!nprio || (tp->protocol != protocol && protocol)) goto errout; } else tp = NULL; break; } } if (tp == NULL) { /* Proto-tcf does not exist, create new one */ if (tca[TCA_KIND] == NULL || !protocol) goto errout; err = -ENOENT; if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags & NLM_F_CREATE)) goto errout; /* Create new proto tcf */ err = -ENOBUFS; tp = kzalloc(sizeof(*tp), GFP_KERNEL); if (tp == NULL) goto errout; err = -ENOENT; tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND]); if (tp_ops == NULL) { #ifdef CONFIG_MODULES struct nlattr *kind = tca[TCA_KIND]; char name[IFNAMSIZ]; if (kind != NULL && nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) { rtnl_unlock(); request_module("cls_%s", name); rtnl_lock(); tp_ops = tcf_proto_lookup_ops(kind); /* We dropped the RTNL semaphore in order to * perform the module load. So, even if we * succeeded in loading the module we have to * replay the request. We indicate this using * -EAGAIN. */ if (tp_ops != NULL) { module_put(tp_ops->owner); err = -EAGAIN; } } #endif kfree(tp); goto errout; } tp->ops = tp_ops; tp->protocol = protocol; tp->prio = nprio ? : TC_H_MAJ(tcf_auto_prio(rtnl_dereference(*back))); tp->q = q; tp->classify = tp_ops->classify; tp->classid = parent; err = tp_ops->init(tp); if (err != 0) { module_put(tp_ops->owner); kfree(tp); goto errout; } tp_created = 1; } else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) goto errout; fh = tp->ops->get(tp, t->tcm_handle); if (fh == 0) { if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) { struct tcf_proto *next = rtnl_dereference(tp->next); RCU_INIT_POINTER(*back, next); tfilter_notify(net, skb, n, tp, fh, RTM_DELTFILTER); tcf_destroy(tp, true); err = 0; goto errout; } err = -ENOENT; if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags & NLM_F_CREATE)) goto errout; } else { switch (n->nlmsg_type) { case RTM_NEWTFILTER: err = -EEXIST; if (n->nlmsg_flags & NLM_F_EXCL) { if (tp_created) tcf_destroy(tp, true); goto errout; } break; case RTM_DELTFILTER: err = tp->ops->delete(tp, fh); if (err == 0) { struct tcf_proto *next = rtnl_dereference(tp->next); tfilter_notify(net, skb, n, tp, fh, RTM_DELTFILTER); if (tcf_destroy(tp, false)) RCU_INIT_POINTER(*back, next); } goto errout; case RTM_GETTFILTER: err = tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER); goto errout; default: err = -EINVAL; goto errout; } } err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh, n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE); if (err == 0) { if (tp_created) { RCU_INIT_POINTER(tp->next, rtnl_dereference(*back)); rcu_assign_pointer(*back, tp); } tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER); } else { if (tp_created) tcf_destroy(tp, true); } errout: if (cl) cops->put(q, cl); if (err == -EAGAIN) /* Replay the request. */ goto replay; return err; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git74960.80%613.04%
patrick mchardypatrick mchardy12810.39%1123.91%
daniel borkmanndaniel borkmann786.33%24.35%
minoru usuiminoru usui504.06%12.17%
cong wangcong wang352.84%24.35%
john fastabendjohn fastabend332.68%12.17%
jamal hadi salimjamal hadi salim302.44%12.17%
hong zhi guohong zhi guo282.27%12.17%
eric w. biedermaneric w. biederman241.95%48.70%
stephen hemmingerstephen hemminger191.54%12.17%
americo wangamerico wang120.97%12.17%
thomas goffthomas goff90.73%12.17%
denis v. lunevdenis v. lunev90.73%12.17%
eric dumazeteric dumazet70.57%36.52%
david s. millerdavid s. miller60.49%36.52%
stephane graberstephane graber40.32%12.17%
robert loverobert love30.24%12.17%
hideaki yoshifujihideaki yoshifuji30.24%12.17%
benjamin lahaisebenjamin lahaise20.16%12.17%
johannes bergjohannes berg10.08%12.17%
linus torvaldslinus torvalds10.08%12.17%
arnaldo carvalho de meloarnaldo carvalho de melo10.08%12.17%
Total1232100.00%46100.00%


static int tcf_fill_node(struct net *net, struct sk_buff *skb, struct tcf_proto *tp, unsigned long fh, u32 portid, u32 seq, u16 flags, int event) { struct tcmsg *tcm; struct nlmsghdr *nlh; unsigned char *b = skb_tail_pointer(skb); nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags); if (!nlh) goto out_nlmsg_trim; tcm = nlmsg_data(nlh); tcm->tcm_family = AF_UNSPEC; tcm->tcm__pad1 = 0; tcm->tcm__pad2 = 0; tcm->tcm_ifindex = qdisc_dev(tp->q)->ifindex; tcm->tcm_parent = tp->classid; tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol); if (nla_put_string(skb, TCA_KIND, tp->ops->kind)) goto nla_put_failure; tcm->tcm_handle = fh; if (RTM_DELTFILTER != event) { tcm->tcm_handle = 0; if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0) goto nla_put_failure; } nlh->nlmsg_len = skb_tail_pointer(skb) - b; return skb->len; out_nlmsg_trim: nla_put_failure: nlmsg_trim(skb, b); return -1; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git17269.92%17.69%
jamal hadi salimjamal hadi salim239.35%215.38%
david s. millerdavid s. miller218.54%323.08%
patrick mchardypatrick mchardy135.28%215.38%
arnaldo carvalho de meloarnaldo carvalho de melo72.85%215.38%
americo wangamerico wang72.85%17.69%
eric w. biedermaneric w. biederman20.81%17.69%
jiri pirkojiri pirko10.41%17.69%
Total246100.00%13100.00%


static int tfilter_notify(struct net *net, struct sk_buff *oskb, struct nlmsghdr *n, struct tcf_proto *tp, unsigned long fh, int event) { struct sk_buff *skb; u32 portid = oskb ? NETLINK_CB(oskb).portid : 0; skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); if (!skb) return -ENOBUFS; if (tcf_fill_node(net, skb, tp, fh, portid, n->nlmsg_seq, 0, event) <= 0) { kfree_skb(skb); return -EINVAL; } return rtnetlink_send(skb, net, portid, RTNLGRP_TC, n->nlmsg_flags & NLM_F_ECHO); }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git11088.71%228.57%
thomas goffthomas goff64.84%114.29%
eric w. biedermaneric w. biederman43.23%114.29%
americo wangamerico wang21.61%114.29%
denis v. lunevdenis v. lunev10.81%114.29%
patrick mchardypatrick mchardy10.81%114.29%
Total124100.00%7100.00%

struct tcf_dump_args { struct tcf_walker w; struct sk_buff *skb; struct netlink_callback *cb; };
static int tcf_node_dump(struct tcf_proto *tp, unsigned long n, struct tcf_walker *arg) { struct tcf_dump_args *a = (void *)arg; struct net *net = sock_net(a->skb->sk); return tcf_fill_node(net, a->skb, tp, n, NETLINK_CB(a->cb->skb).portid, a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER); }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git6579.27%133.33%
americo wangamerico wang1619.51%133.33%
eric w. biedermaneric w. biederman11.22%133.33%
Total82100.00%3100.00%

/* called with RTNL */
static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) { struct net *net = sock_net(skb->sk); int t; int s_t; struct net_device *dev; struct Qdisc *q; struct tcf_proto *tp, __rcu **chain; struct tcmsg *tcm = nlmsg_data(cb->nlh); unsigned long cl = 0; const struct Qdisc_class_ops *cops; struct tcf_dump_args arg; if (nlmsg_len(cb->nlh) < sizeof(*tcm)) return skb->len; dev = __dev_get_by_index(net, tcm->tcm_ifindex); if (!dev) return skb->len; if (!tcm->tcm_parent) q = dev->qdisc; else q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent)); if (!q) goto out; cops = q->ops->cl_ops; if (!cops) goto errout; if (cops->tcf_chain == NULL) goto errout; if (TC_H_MIN(tcm->tcm_parent)) { cl = cops->get(q, tcm->tcm_parent); if (cl == 0) goto errout; } chain = cops->tcf_chain(q, cl); if (chain == NULL) goto errout; s_t = cb->args[0]; for (tp = rtnl_dereference(*chain), t = 0; tp; tp = rtnl_dereference(tp->next), t++) { if (t < s_t) continue; if (TC_H_MAJ(tcm->tcm_info) && TC_H_MAJ(tcm->tcm_info) != tp->prio) continue; if (TC_H_MIN(tcm->tcm_info) && TC_H_MIN(tcm->tcm_info) != tp->protocol) continue; if (t > s_t) memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0])); if (cb->args[1] == 0) { if (tcf_fill_node(net, skb, tp, 0, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER) <= 0) break; cb->args[1] = 1; } if (tp->ops->walk == NULL) continue; arg.w.fn = tcf_node_dump; arg.skb = skb; arg.cb = cb; arg.w.stop = 0; arg.w.skip = cb->args[1] - 1; arg.w.count = 0; tp->ops->walk(tp, &arg.w); cb->args[1] = arg.w.count + 1; if (arg.w.stop) break; } cb->args[0] = t; errout: if (cl) cops->put(q, cl); out: return skb->len; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git49289.29%316.67%
patrick mchardypatrick mchardy132.36%211.11%
eric dumazeteric dumazet122.18%316.67%
denis v. lunevdenis v. lunev91.63%15.56%
john fastabendjohn fastabend71.27%15.56%
arnaldo carvalho de meloarnaldo carvalho de melo61.09%15.56%
hideaki yoshifujihideaki yoshifuji30.54%15.56%
hong zhi guohong zhi guo30.54%15.56%
eric w. biedermaneric w. biederman20.36%211.11%
americo wangamerico wang20.36%15.56%
thomas goffthomas goff10.18%15.56%
david s. millerdavid s. miller10.18%15.56%
Total551100.00%18100.00%


void tcf_exts_destroy(struct tcf_exts *exts) { #ifdef CONFIG_NET_CLS_ACT LIST_HEAD(actions); tcf_exts_to_list(exts, &actions); tcf_action_destroy(&actions, TCA_ACT_UNBIND); kfree(exts->actions); exts->nr_actions = 0; #endif }

Contributors

PersonTokensPropCommitsCommitProp
americo wangamerico wang2551.02%250.00%
thomas grafthomas graf2346.94%125.00%
stephen hemmingerstephen hemminger12.04%125.00%
Total49100.00%4100.00%

EXPORT_SYMBOL(tcf_exts_destroy);
int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb, struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr) { #ifdef CONFIG_NET_CLS_ACT { struct tc_action *act; if (exts->police && tb[exts->police]) { act = tcf_action_init_1(net, tb[exts->police], rate_tlv, "police", ovr, TCA_ACT_BIND); if (IS_ERR(act)) return PTR_ERR(act); act->type = exts->type = TCA_OLD_COMPAT; exts->actions[0] = act; exts->nr_actions = 1; } else if (exts->action && tb[exts->action]) { LIST_HEAD(actions); int err, i = 0; err = tcf_action_init(net, tb[exts->action], rate_tlv, NULL, ovr, TCA_ACT_BIND, &actions); if (err) return err; list_for_each_entry(act, &actions, list) exts->actions[i++] = act; exts->nr_actions = i; } } #else if ((exts->action && tb[exts->action]) || (exts->police && tb[exts->police])) return -EOPNOTSUPP; #endif return 0; }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf14961.57%220.00%
americo wangamerico wang6928.51%330.00%
benjamin lahaisebenjamin lahaise93.72%110.00%
patrick mchardypatrick mchardy93.72%220.00%
cong wangcong wang52.07%110.00%
stephen hemmingerstephen hemminger10.41%110.00%
Total242100.00%10100.00%

EXPORT_SYMBOL(tcf_exts_validate);
void tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst, struct tcf_exts *src) { #ifdef CONFIG_NET_CLS_ACT struct tcf_exts old = *dst; tcf_tree_lock(tp); dst->nr_actions = src->nr_actions; dst->actions = src->actions; dst->type = src->type