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[IPV6]: Increase number of possible routing tables to 2^32
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Increase number of possible routing tables to 2^32 by replacing iterations
over all possible table IDs by hash table walking.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Patrick McHardy authored and David S. Miller committed Sep 22, 2006
1 parent 1af5a8c commit 1b43af5
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Showing 3 changed files with 159 additions and 147 deletions.
7 changes: 7 additions & 0 deletions include/net/ip6_route.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -137,6 +137,13 @@ extern int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *a
extern int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);
extern int inet6_rtm_getroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg);

struct rt6_rtnl_dump_arg
{
struct sk_buff *skb;
struct netlink_callback *cb;
};

extern int rt6_dump_route(struct rt6_info *rt, void *p_arg);
extern void rt6_ifdown(struct net_device *dev);
extern void rt6_mtu_change(struct net_device *dev, unsigned mtu);

Expand Down
171 changes: 151 additions & 20 deletions net/ipv6/ip6_fib.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -158,7 +158,26 @@ static struct fib6_table fib6_main_tbl = {
};

#ifdef CONFIG_IPV6_MULTIPLE_TABLES
#define FIB_TABLE_HASHSZ 256
#else
#define FIB_TABLE_HASHSZ 1
#endif
static struct hlist_head fib_table_hash[FIB_TABLE_HASHSZ];

static void fib6_link_table(struct fib6_table *tb)
{
unsigned int h;

h = tb->tb6_id & (FIB_TABLE_HASHSZ - 1);

/*
* No protection necessary, this is the only list mutatation
* operation, tables never disappear once they exist.
*/
hlist_add_head_rcu(&tb->tb6_hlist, &fib_table_hash[h]);
}

#ifdef CONFIG_IPV6_MULTIPLE_TABLES
static struct fib6_table fib6_local_tbl = {
.tb6_id = RT6_TABLE_LOCAL,
.tb6_lock = RW_LOCK_UNLOCKED,
Expand All @@ -168,9 +187,6 @@ static struct fib6_table fib6_local_tbl = {
},
};

#define FIB_TABLE_HASHSZ 256
static struct hlist_head fib_table_hash[FIB_TABLE_HASHSZ];

static struct fib6_table *fib6_alloc_table(u32 id)
{
struct fib6_table *table;
Expand All @@ -186,19 +202,6 @@ static struct fib6_table *fib6_alloc_table(u32 id)
return table;
}

static void fib6_link_table(struct fib6_table *tb)
{
unsigned int h;

h = tb->tb6_id & (FIB_TABLE_HASHSZ - 1);

/*
* No protection necessary, this is the only list mutatation
* operation, tables never disappear once they exist.
*/
hlist_add_head_rcu(&tb->tb6_hlist, &fib_table_hash[h]);
}

struct fib6_table *fib6_new_table(u32 id)
{
struct fib6_table *tb;
Expand Down Expand Up @@ -263,10 +266,135 @@ struct dst_entry *fib6_rule_lookup(struct flowi *fl, int flags,

static void __init fib6_tables_init(void)
{
fib6_link_table(&fib6_main_tbl);
}

#endif

static int fib6_dump_node(struct fib6_walker_t *w)
{
int res;
struct rt6_info *rt;

for (rt = w->leaf; rt; rt = rt->u.next) {
res = rt6_dump_route(rt, w->args);
if (res < 0) {
/* Frame is full, suspend walking */
w->leaf = rt;
return 1;
}
BUG_TRAP(res!=0);
}
w->leaf = NULL;
return 0;
}

static void fib6_dump_end(struct netlink_callback *cb)
{
struct fib6_walker_t *w = (void*)cb->args[2];

if (w) {
cb->args[2] = 0;
kfree(w);
}
cb->done = (void*)cb->args[3];
cb->args[1] = 3;
}

static int fib6_dump_done(struct netlink_callback *cb)
{
fib6_dump_end(cb);
return cb->done ? cb->done(cb) : 0;
}

static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
struct netlink_callback *cb)
{
struct fib6_walker_t *w;
int res;

w = (void *)cb->args[2];
w->root = &table->tb6_root;

if (cb->args[4] == 0) {
read_lock_bh(&table->tb6_lock);
res = fib6_walk(w);
read_unlock_bh(&table->tb6_lock);
if (res > 0)
cb->args[4] = 1;
} else {
read_lock_bh(&table->tb6_lock);
res = fib6_walk_continue(w);
read_unlock_bh(&table->tb6_lock);
if (res != 0) {
if (res < 0)
fib6_walker_unlink(w);
goto end;
}
fib6_walker_unlink(w);
cb->args[4] = 0;
}
end:
return res;
}

int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
{
unsigned int h, s_h;
unsigned int e = 0, s_e;
struct rt6_rtnl_dump_arg arg;
struct fib6_walker_t *w;
struct fib6_table *tb;
struct hlist_node *node;
int res = 0;

s_h = cb->args[0];
s_e = cb->args[1];

w = (void *)cb->args[2];
if (w == NULL) {
/* New dump:
*
* 1. hook callback destructor.
*/
cb->args[3] = (long)cb->done;
cb->done = fib6_dump_done;

/*
* 2. allocate and initialize walker.
*/
w = kzalloc(sizeof(*w), GFP_ATOMIC);
if (w == NULL)
return -ENOMEM;
w->func = fib6_dump_node;
cb->args[2] = (long)w;
}

arg.skb = skb;
arg.cb = cb;
w->args = &arg;

for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
e = 0;
hlist_for_each_entry(tb, node, &fib_table_hash[h], tb6_hlist) {
if (e < s_e)
goto next;
res = fib6_dump_table(tb, skb, cb);
if (res != 0)
goto out;
next:
e++;
}
}
out:
cb->args[1] = e;
cb->args[0] = h;

res = res < 0 ? res : skb->len;
if (res <= 0)
fib6_dump_end(cb);
return res;
}

/*
* Routing Table
Expand Down Expand Up @@ -1187,17 +1315,20 @@ static void fib6_clean_tree(struct fib6_node *root,
void fib6_clean_all(int (*func)(struct rt6_info *, void *arg),
int prune, void *arg)
{
int i;
struct fib6_table *table;
struct hlist_node *node;
unsigned int h;

for (i = FIB6_TABLE_MIN; i <= FIB6_TABLE_MAX; i++) {
table = fib6_get_table(i);
if (table != NULL) {
rcu_read_lock();
for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
hlist_for_each_entry_rcu(table, node, &fib_table_hash[h],
tb6_hlist) {
write_lock_bh(&table->tb6_lock);
fib6_clean_tree(&table->tb6_root, func, prune, arg);
write_unlock_bh(&table->tb6_lock);
}
}
rcu_read_unlock();
}

static int fib6_prune_clone(struct rt6_info *rt, void *arg)
Expand Down
128 changes: 1 addition & 127 deletions net/ipv6/route.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1874,12 +1874,6 @@ int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
rtm_get_table(arg, r->rtm_table));
}

struct rt6_rtnl_dump_arg
{
struct sk_buff *skb;
struct netlink_callback *cb;
};

static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt,
struct in6_addr *dst, struct in6_addr *src,
int iif, int type, u32 pid, u32 seq,
Expand Down Expand Up @@ -1976,7 +1970,7 @@ static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt,
return -1;
}

static int rt6_dump_route(struct rt6_info *rt, void *p_arg)
int rt6_dump_route(struct rt6_info *rt, void *p_arg)
{
struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
int prefix;
Expand All @@ -1992,126 +1986,6 @@ static int rt6_dump_route(struct rt6_info *rt, void *p_arg)
prefix, NLM_F_MULTI);
}

static int fib6_dump_node(struct fib6_walker_t *w)
{
int res;
struct rt6_info *rt;

for (rt = w->leaf; rt; rt = rt->u.next) {
res = rt6_dump_route(rt, w->args);
if (res < 0) {
/* Frame is full, suspend walking */
w->leaf = rt;
return 1;
}
BUG_TRAP(res!=0);
}
w->leaf = NULL;
return 0;
}

static void fib6_dump_end(struct netlink_callback *cb)
{
struct fib6_walker_t *w = (void*)cb->args[0];

if (w) {
cb->args[0] = 0;
kfree(w);
}
cb->done = (void*)cb->args[1];
cb->args[1] = 0;
}

static int fib6_dump_done(struct netlink_callback *cb)
{
fib6_dump_end(cb);
return cb->done ? cb->done(cb) : 0;
}

int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
{
struct fib6_table *table;
struct rt6_rtnl_dump_arg arg;
struct fib6_walker_t *w;
int i, res = 0;

arg.skb = skb;
arg.cb = cb;

/*
* cb->args[0] = pointer to walker structure
* cb->args[1] = saved cb->done() pointer
* cb->args[2] = current table being dumped
*/

w = (void*)cb->args[0];
if (w == NULL) {
/* New dump:
*
* 1. hook callback destructor.
*/
cb->args[1] = (long)cb->done;
cb->done = fib6_dump_done;

/*
* 2. allocate and initialize walker.
*/
w = kzalloc(sizeof(*w), GFP_ATOMIC);
if (w == NULL)
return -ENOMEM;
w->func = fib6_dump_node;
w->args = &arg;
cb->args[0] = (long)w;
cb->args[2] = FIB6_TABLE_MIN;
} else {
w->args = &arg;
i = cb->args[2];
if (i > FIB6_TABLE_MAX)
goto end;

table = fib6_get_table(i);
if (table != NULL) {
read_lock_bh(&table->tb6_lock);
w->root = &table->tb6_root;
res = fib6_walk_continue(w);
read_unlock_bh(&table->tb6_lock);
if (res != 0) {
if (res < 0)
fib6_walker_unlink(w);
goto end;
}
}

fib6_walker_unlink(w);
cb->args[2] = ++i;
}

for (i = cb->args[2]; i <= FIB6_TABLE_MAX; i++) {
table = fib6_get_table(i);
if (table == NULL)
continue;

read_lock_bh(&table->tb6_lock);
w->root = &table->tb6_root;
res = fib6_walk(w);
read_unlock_bh(&table->tb6_lock);
if (res)
break;
}
end:
cb->args[2] = i;

res = res < 0 ? res : skb->len;
/* res < 0 is an error. (really, impossible)
res == 0 means that dump is complete, but skb still can contain data.
res > 0 dump is not complete, but frame is full.
*/
/* Destroy walker, if dump of this table is complete. */
if (res <= 0)
fib6_dump_end(cb);
return res;
}

int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
{
struct rtattr **rta = arg;
Expand Down

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