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linux/net/ipv6/ip6_flowlabel.c
James Morris 1b7c2dbc07 [IPV6]: fix flowlabel seqfile handling 
There's a bug in the seqfile show operation for flowlabel objects, where 
each hash chain is traversed cumulatively for each element.  The following 
function is called for each element of each chain:

static void ip6fl_fl_seq_show(struct seq_file *seq, struct ip6_flowlabel *fl)
{
        while(fl) {
                seq_printf...
		
		fl = fl->next;
	}
}

Thus, objects can appear mutliple times when reading 
/proc/net/ip6_flowlabel, as the above is called for each element in the 
chain.

The solution is to remove the while() loop from the above, and traverse 
each chain exactly once, per the patch below.  This also removes the 
ip6fl_fl_seq_show() function, which does nothing else.

Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-10-31 00:43:44 -08:00

704 lines
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/*
* 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 <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(u32 label)
{
struct ip6_flowlabel *fl;
for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
if (fl->label == label)
return fl;
}
return NULL;
}
static struct ip6_flowlabel * fl_lookup(u32 label)
{
struct ip6_flowlabel *fl;
read_lock_bh(&ip6_fl_lock);
fl = __fl_lookup(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)
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) {
ip6_fl_gc_timer.expires = sched;
add_timer(&ip6_fl_gc_timer);
}
write_unlock(&ip6_fl_lock);
}
static int fl_intern(struct ip6_flowlabel *fl, __u32 label)
{
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) {
struct ip6_flowlabel *lfl;
lfl = __fl_lookup(fl->label);
if (lfl == NULL)
break;
}
}
}
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 0;
}
/* Socket flowlabel lists */
struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, u32 label)
{
struct ipv6_fl_socklist *sfl;
struct ipv6_pinfo *np = inet6_sk(sk);
label &= IPV6_FLOWLABEL_MASK;
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);
return fl;
}
}
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 in6_flowlabel_req *freq, char __user *optval, int optlen, int *err_p)
{
struct ip6_flowlabel *fl;
int olen;
int addr_type;
int err;
err = -ENOMEM;
fl = kzalloc(sizeof(*fl), GFP_KERNEL);
if (fl == NULL)
goto done;
olen = optlen - CMSG_ALIGN(sizeof(*freq));
if (olen > 0) {
struct msghdr msg;
struct flowi flowi;
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);
flowi.oif = 0;
err = datagram_send_ctl(&msg, &flowi, fl->opt, &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->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;
}
ipv6_addr_copy(&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;
}
int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
{
int err;
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;
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(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(&freq, optval, optlen, &err);
if (fl == NULL)
return err;
sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
if (freq.flr_label) {
struct ip6_flowlabel *fl1 = NULL;
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(freq.flr_label);
if (fl1) {
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;
write_lock_bh(&ip6_sk_fl_lock);
sfl1->fl = fl1;
sfl1->next = np->ipv6_fl_list;
np->ipv6_fl_list = sfl1;
write_unlock_bh(&ip6_sk_fl_lock);
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;
err = fl_intern(fl, freq.flr_label);
if (err)
goto done;
if (!freq.flr_label) {
if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
&fl->label, sizeof(fl->label))) {
/* Intentionally ignore fault. */
}
}
sfl1->fl = fl;
sfl1->next = np->ipv6_fl_list;
np->ipv6_fl_list = sfl1;
return 0;
default:
return -EINVAL;
}
done:
fl_free(fl);
kfree(sfl1);
return err;
}
#ifdef CONFIG_PROC_FS
struct ip6fl_iter_state {
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);
for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
if (fl_ht[state->bucket]) {
fl = fl_ht[state->bucket];
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);
fl = fl->next;
while (!fl) {
if (++state->bucket <= FL_HASH_MASK)
fl = fl_ht[state->bucket];
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)
{
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)
{
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 " NIP6_SEQFMT " %-4d\n",
(unsigned)ntohl(fl->label),
fl->share,
(unsigned)fl->owner,
atomic_read(&fl->users),
fl->linger/HZ,
(long)(fl->expires - jiffies)/HZ,
NIP6(fl->dst),
fl->opt ? fl->opt->opt_nflen : 0);
}
return 0;
}
static 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)
{
struct seq_file *seq;
int rc = -ENOMEM;
struct ip6fl_iter_state *s = kzalloc(sizeof(*s), GFP_KERNEL);
if (!s)
goto out;
rc = seq_open(file, &ip6fl_seq_ops);
if (rc)
goto out_kfree;
seq = file->private_data;
seq->private = s;
out:
return rc;
out_kfree:
kfree(s);
goto out;
}
static struct file_operations ip6fl_seq_fops = {
.owner = THIS_MODULE,
.open = ip6fl_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_private,
};
#endif
void ip6_flowlabel_init(void)
{
#ifdef CONFIG_PROC_FS
proc_net_fops_create("ip6_flowlabel", S_IRUGO, &ip6fl_seq_fops);
#endif
}
void ip6_flowlabel_cleanup(void)
{
del_timer(&ip6_fl_gc_timer);
#ifdef CONFIG_PROC_FS
proc_net_remove("ip6_flowlabel");
#endif
}
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