- 根目录:
- net
- ipv6
- ip6_flowlabel.c
/*
* ip6_flowlabel.c IPv6 flowlabel manager.
*
* 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>
*/
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/in6.h>
#include <linux/route.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/ipv6.h>
#include <net/ndisc.h>
#include <net/protocol.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#include <net/rawv6.h>
#include <net/icmp.h>
#include <net/transp_v6.h>
#include <asm/uaccess.h>
#define FL_MIN_LINGER 6 /* Minimal linger. It is set to 6sec specified
in old IPv6 RFC. Well, it was reasonable value.
*/
#define FL_MAX_LINGER 60 /* Maximal linger timeout */
/* FL hash table */
#define FL_MAX_PER_SOCK 32
#define FL_MAX_SIZE 4096
#define FL_HASH_MASK 255
#define FL_HASH(l) (ntohl(l)&FL_HASH_MASK)
static atomic_t fl_size = ATOMIC_INIT(0);
static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1];
static void ip6_fl_gc(unsigned long dummy);
static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
/* FL hash table lock: it protects only of GC */
static DEFINE_RWLOCK(ip6_fl_lock);
/* Big socket sock */
static DEFINE_RWLOCK(ip6_sk_fl_lock);
static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
{
struct ip6_flowlabel *fl;
for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
if (fl->label == label && net_eq(fl->fl_net, net))
return fl;
}
return NULL;
}
static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
{
struct ip6_flowlabel *fl;
read_lock_bh(&ip6_fl_lock);
fl = __fl_lookup(net, label);
if (fl)
atomic_inc(&fl->users);
read_unlock_bh(&ip6_fl_lock);
return fl;
}
static void fl_free(struct ip6_flowlabel *fl)
{
if (fl) {
release_net(fl->fl_net);
kfree(fl->opt);
}
kfree(fl);
}
static void fl_release(struct ip6_flowlabel *fl)
{
write_lock_bh(&ip6_fl_lock);
fl->lastuse = jiffies;
if (atomic_dec_and_test(&fl->users)) {
unsigned long ttd = fl->lastuse + fl->linger;
if (time_after(ttd, fl->expires))
fl->expires = ttd;
ttd = fl->expires;
if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
struct ipv6_txoptions *opt = fl->opt;
fl->opt = NULL;
kfree(opt);
}
if (!timer_pending(&ip6_fl_gc_timer) ||
time_after(ip6_fl_gc_timer.expires, ttd))
mod_timer(&ip6_fl_gc_timer, ttd);
}
write_unlock_bh(&ip6_fl_lock);
}
static void ip6_fl_gc(unsigned long dummy)
{
int i;
unsigned long now = jiffies;
unsigned long sched = 0;
write_lock(&ip6_fl_lock);
for (i=0; i<=FL_HASH_MASK; i++) {
struct ip6_flowlabel *fl, **flp;
flp = &fl_ht[i];
while ((fl=*flp) != NULL) {
if (atomic_read(&fl->users) == 0) {
unsigned long ttd = fl->lastuse + fl->linger;
if (time_after(ttd, fl->expires))
fl->expires = ttd;
ttd = fl->expires;
if (time_after_eq(now, ttd)) {
*flp = fl->next;
fl_free(fl);
atomic_dec(&fl_size);
continue;
}
if (!sched || time_before(ttd, sched))
sched = ttd;
}
flp = &fl->next;
}
}
if (!sched && atomic_read(&fl_size))
sched = now + FL_MAX_LINGER;
if (sched) {
mod_timer(&ip6_fl_gc_timer, sched);
}
write_unlock(&ip6_fl_lock);
}
static void __net_exit ip6_fl_purge(struct net *net)
{
int i;
write_lock(&ip6_fl_lock);
for (i = 0; i <= FL_HASH_MASK; i++) {
struct ip6_flowlabel *fl, **flp;
flp = &fl_ht[i];
while ((fl = *flp) != NULL) {
if (net_eq(fl->fl_net, net) &&
atomic_read(&fl->users) == 0) {
*flp = fl->next;
fl_free(fl);
atomic_dec(&fl_size);
continue;
}
flp = &fl->next;
}
}
write_unlock(&ip6_fl_lock);
}
static struct ip6_flowlabel *fl_intern(struct net *net,
struct ip6_flowlabel *fl, __be32 label)
{
struct ip6_flowlabel *lfl;
fl->label = label & IPV6_FLOWLABEL_MASK;
write_lock_bh(&ip6_fl_lock);
if (label == 0) {
for (;;) {
fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
if (fl->label) {
lfl = __fl_lookup(net, fl->label);
if (lfl == NULL)
break;
}
}
} else {
/*
* we dropper the ip6_fl_lock, so this entry could reappear
* and we need to recheck with it.
*
* OTOH no need to search the active socket first, like it is
* done in ipv6_flowlabel_opt - sock is locked, so new entry
* with the same label can only appear on another sock
*/
lfl = __fl_lookup(net, fl->label);
if (lfl != NULL) {
atomic_inc(&lfl->users);
write_unlock_bh(&ip6_fl_lock);
return lfl;
}
}
fl->lastuse = jiffies;
fl->next = fl_ht[FL_HASH(fl->label)];
fl_ht[FL_HASH(fl->label)] = fl;
atomic_inc(&fl_size);
write_unlock_bh(&ip6_fl_lock);
return NULL;
}
/* Socket flowlabel lists */
struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
{
struct ipv6_fl_socklist *sfl;
struct ipv6_pinfo *np = inet6_sk(sk);
label &= IPV6_FLOWLABEL_MASK;
read_lock_bh(&ip6_sk_fl_lock);
for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
struct ip6_flowlabel *fl = sfl->fl;
if (fl->label == label) {
fl->lastuse = jiffies;
atomic_inc(&fl->users);
read_unlock_bh(&ip6_sk_fl_lock);
return fl;
}
}
read_unlock_bh(&ip6_sk_fl_lock);
return NULL;
}
EXPORT_SYMBOL_GPL(fl6_sock_lookup);
void fl6_free_socklist(struct sock *sk)
{
struct ipv6_pinfo *np = inet6_sk(sk);
struct ipv6_fl_socklist *sfl;
while ((sfl = np->ipv6_fl_list) != NULL) {
np->ipv6_fl_list = sfl->next;
fl_release(sfl->fl);
kfree(sfl);
}
}
/* Service routines */
/*
It is the only difficult place. flowlabel enforces equal headers
before and including routing header, however user may supply options
following rthdr.
*/
struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
struct ip6_flowlabel * fl,
struct ipv6_txoptions * fopt)
{
struct ipv6_txoptions * fl_opt = fl->opt;
if (fopt == NULL || fopt->opt_flen == 0)
return fl_opt;
if (fl_opt != NULL) {
opt_space->hopopt = fl_opt->hopopt;
opt_space->dst0opt = fl_opt->dst0opt;
opt_space->srcrt = fl_opt->srcrt;
opt_space->opt_nflen = fl_opt->opt_nflen;
} else {
if (fopt->opt_nflen == 0)
return fopt;
opt_space->hopopt = NULL;
opt_space->dst0opt = NULL;
opt_space->srcrt = NULL;
opt_space->opt_nflen = 0;
}
opt_space->dst1opt = fopt->dst1opt;
opt_space->opt_flen = fopt->opt_flen;
return opt_space;
}
static unsigned long check_linger(unsigned long ttl)
{
if (ttl < FL_MIN_LINGER)
return FL_MIN_LINGER*HZ;
if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
return 0;
return ttl*HZ;
}
static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
{
linger = check_linger(linger);
if (!linger)
return -EPERM;
expires = check_linger(expires);
if (!expires)
return -EPERM;
fl->lastuse = jiffies;
if (time_before(fl->linger, linger))
fl->linger = linger;
if (time_before(expires, fl->linger))
expires = fl->linger;
if (time_before(fl->expires, fl->lastuse + expires))
fl->expires = fl->lastuse + expires;
return 0;
}
static struct ip6_flowlabel *
fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
char __user *optval, int optlen, int *err_p)
{
struct ip6_flowlabel *fl = NULL;
int olen;
int addr_type;
int err;
olen = optlen - CMSG_ALIGN(sizeof(*freq));
err = -EINVAL;
if (olen > 64 * 1024)
goto done;
err = -ENOMEM;
fl = kzalloc(sizeof(*fl), GFP_KERNEL);
if (fl == NULL)
goto done;
if (olen > 0) {
struct msghdr msg;
struct flowi6 flowi6;
int junk;
err = -ENOMEM;
fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
if (fl->opt == NULL)
goto done;
memset(fl->opt, 0, sizeof(*fl->opt));
fl->opt->tot_len = sizeof(*fl->opt) + olen;
err = -EFAULT;
if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
goto done;
msg.msg_controllen = olen;
msg.msg_control = (void*)(fl->opt+1);
memset(&flowi6, 0, sizeof(flowi6));
err = datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt, &junk,
&junk, &junk);
if (err)
goto done;
err = -EINVAL;
if (fl->opt->opt_flen)
goto done;
if (fl->opt->opt_nflen == 0) {
kfree(fl->opt);
fl->opt = NULL;
}
}
fl->fl_net = hold_net(net);
fl->expires = jiffies;
err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
if (err)
goto done;
fl->share = freq->flr_share;
addr_type = ipv6_addr_type(&freq->flr_dst);
if ((addr_type & IPV6_ADDR_MAPPED) ||
addr_type == IPV6_ADDR_ANY) {
err = -EINVAL;
goto done;
}
fl->dst = freq->flr_dst;
atomic_set(&fl->users, 1);
switch (fl->share) {
case IPV6_FL_S_EXCL:
case IPV6_FL_S_ANY:
break;
case IPV6_FL_S_PROCESS:
fl->owner = current->pid;
break;
case IPV6_FL_S_USER:
fl->owner = current_euid();
break;
default:
err = -EINVAL;
goto done;
}
return fl;
done:
fl_free(fl);
*err_p = err;
return NULL;
}
static int mem_check(struct sock *sk)
{
struct ipv6_pinfo *np = inet6_sk(sk);
struct ipv6_fl_socklist *sfl;
int room = FL_MAX_SIZE - atomic_read(&fl_size);
int count = 0;
if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
return 0;
for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
count++;
if (room <= 0 ||
((count >= FL_MAX_PER_SOCK ||
(count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
!capable(CAP_NET_ADMIN)))
return -ENOBUFS;
return 0;
}
static int ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
{
if (h1 == h2)
return 0;
if (h1 == NULL || h2 == NULL)
return 1;
if (h1->hdrlen != h2->hdrlen)
return 1;
return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
}
static int ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
{
if (o1 == o2)
return 0;
if (o1 == NULL || o2 == NULL)
return 1;
if (o1->opt_nflen != o2->opt_nflen)
return 1;
if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
return 1;
if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
return 1;
if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
return 1;
return 0;
}
static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
struct ip6_flowlabel *fl)
{
write_lock_bh(&ip6_sk_fl_lock);
sfl->fl = fl;
sfl->next = np->ipv6_fl_list;
np->ipv6_fl_list = sfl;
write_unlock_bh(&ip6_sk_fl_lock);
}
int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
{
int uninitialized_var(err);
struct net *net = sock_net(sk);
struct ipv6_pinfo *np = inet6_sk(sk);
struct in6_flowlabel_req freq;
struct ipv6_fl_socklist *sfl1=NULL;
struct ipv6_fl_socklist *sfl, **sflp;
struct ip6_flowlabel *fl, *fl1 = NULL;
if (optlen < sizeof(freq))
return -EINVAL;
if (copy_from_user(&freq, optval, sizeof(freq)))
return -EFAULT;
switch (freq.flr_action) {
case IPV6_FL_A_PUT:
write_lock_bh(&ip6_sk_fl_lock);
for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
if (sfl->fl->label == freq.flr_label) {
if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
np->flow_label &= ~IPV6_FLOWLABEL_MASK;
*sflp = sfl->next;
write_unlock_bh(&ip6_sk_fl_lock);
fl_release(sfl->fl);
kfree(sfl);
return 0;
}
}
write_unlock_bh(&ip6_sk_fl_lock);
return -ESRCH;
case IPV6_FL_A_RENEW:
read_lock_bh(&ip6_sk_fl_lock);
for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
if (sfl->fl->label == freq.flr_label) {
err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
read_unlock_bh(&ip6_sk_fl_lock);
return err;
}
}
read_unlock_bh(&ip6_sk_fl_lock);
if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
fl = fl_lookup(net, freq.flr_label);
if (fl) {
err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
fl_release(fl);
return err;
}
}
return -ESRCH;
case IPV6_FL_A_GET:
if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
return -EINVAL;
fl = fl_create(net, sk, &freq, optval, optlen, &err);
if (fl == NULL)
return err;
sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
if (freq.flr_label) {
err = -EEXIST;
read_lock_bh(&ip6_sk_fl_lock);
for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
if (sfl->fl->label == freq.flr_label) {
if (freq.flr_flags&IPV6_FL_F_EXCL) {
read_unlock_bh(&ip6_sk_fl_lock);
goto done;
}
fl1 = sfl->fl;
atomic_inc(&fl1->users);
break;
}
}
read_unlock_bh(&ip6_sk_fl_lock);
if (fl1 == NULL)
fl1 = fl_lookup(net, freq.flr_label);
if (fl1) {
recheck:
err = -EEXIST;
if (freq.flr_flags&IPV6_FL_F_EXCL)
goto release;
err = -EPERM;
if (fl1->share == IPV6_FL_S_EXCL ||
fl1->share != fl->share ||
fl1->owner != fl->owner)
goto release;
err = -EINVAL;
if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
ipv6_opt_cmp(fl1->opt, fl->opt))
goto release;
err = -ENOMEM;
if (sfl1 == NULL)
goto release;
if (fl->linger > fl1->linger)
fl1->linger = fl->linger;
if ((long)(fl->expires - fl1->expires) > 0)
fl1->expires = fl->expires;
fl_link(np, sfl1, fl1);
fl_free(fl);
return 0;
release:
fl_release(fl1);
goto done;
}
}
err = -ENOENT;
if (!(freq.flr_flags&IPV6_FL_F_CREATE))
goto done;
err = -ENOMEM;
if (sfl1 == NULL || (err = mem_check(sk)) != 0)
goto done;
fl1 = fl_intern(net, fl, freq.flr_label);
if (fl1 != NULL)
goto recheck;
if (!freq.flr_label) {
if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
&fl->label, sizeof(fl->label))) {
/* Intentionally ignore fault. */
}
}
fl_link(np, sfl1, fl);
return 0;
default:
return -EINVAL;
}
done:
fl_free(fl);
kfree(sfl1);
return err;
}
#ifdef CONFIG_PROC_FS
struct ip6fl_iter_state {
struct seq_net_private p;
int bucket;
};
#define ip6fl_seq_private(seq) ((struct ip6fl_iter_state *)(seq)->private)
static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
{
struct ip6_flowlabel *fl = NULL;
struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
struct net *net = seq_file_net(seq);
for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
fl = fl_ht[state->bucket];
while (fl && !net_eq(fl->fl_net, net))
fl = fl->next;
if (fl)
break;
}
return fl;
}
static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
{
struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
struct net *net = seq_file_net(seq);
fl = fl->next;
try_again:
while (fl && !net_eq(fl->fl_net, net))
fl = fl->next;
while (!fl) {
if (++state->bucket <= FL_HASH_MASK) {
fl = fl_ht[state->bucket];
goto try_again;
} else
break;
}
return fl;
}
static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
{
struct ip6_flowlabel *fl = ip6fl_get_first(seq);
if (fl)
while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
--pos;
return pos ? NULL : fl;
}
static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(ip6_fl_lock)
{
read_lock_bh(&ip6_fl_lock);
return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
}
static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct ip6_flowlabel *fl;
if (v == SEQ_START_TOKEN)
fl = ip6fl_get_first(seq);
else
fl = ip6fl_get_next(seq, v);
++*pos;
return fl;
}
static void ip6fl_seq_stop(struct seq_file *seq, void *v)
__releases(ip6_fl_lock)
{
read_unlock_bh(&ip6_fl_lock);
}
static int ip6fl_seq_show(struct seq_file *seq, void *v)
{
if (v == SEQ_START_TOKEN)
seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
"Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
else {
struct ip6_flowlabel *fl = v;
seq_printf(seq,
"%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
(unsigned)ntohl(fl->label),
fl->share,
(unsigned)fl->owner,
atomic_read(&fl->users),
fl->linger/HZ,
(long)(fl->expires - jiffies)/HZ,
&fl->dst,
fl->opt ? fl->opt->opt_nflen : 0);
}
return 0;
}
static const struct seq_operations ip6fl_seq_ops = {
.start = ip6fl_seq_start,
.next = ip6fl_seq_next,
.stop = ip6fl_seq_stop,
.show = ip6fl_seq_show,
};
static int ip6fl_seq_open(struct inode *inode, struct file *file)
{
return seq_open_net(inode, file, &ip6fl_seq_ops,
sizeof(struct ip6fl_iter_state));
}
static const struct file_operations ip6fl_seq_fops = {
.owner = THIS_MODULE,
.open = ip6fl_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net,
};
static int __net_init ip6_flowlabel_proc_init(struct net *net)
{
if (!proc_net_fops_create(net, "ip6_flowlabel",
S_IRUGO, &ip6fl_seq_fops))
return -ENOMEM;
return 0;
}
static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
{
proc_net_remove(net, "ip6_flowlabel");
}
#else
static inline int ip6_flowlabel_proc_init(struct net *net)
{
return 0;
}
static inline void ip6_flowlabel_proc_fini(struct net *net)
{
}
#endif
static void __net_exit ip6_flowlabel_net_exit(struct net *net)
{
ip6_fl_purge(net);
ip6_flowlabel_proc_fini(net);
}
static struct pernet_operations ip6_flowlabel_net_ops = {
.init = ip6_flowlabel_proc_init,
.exit = ip6_flowlabel_net_exit,
};
int ip6_flowlabel_init(void)
{
return register_pernet_subsys(&ip6_flowlabel_net_ops);
}
void ip6_flowlabel_cleanup(void)
{
del_timer(&ip6_fl_gc_timer);
unregister_pernet_subsys(&ip6_flowlabel_net_ops);
}