kernel-ark/include/net/request_sock.h
Pavel Emelyanov dab6ba3688 [INET]: Fix potential kfree on vmalloc-ed area of request_sock_queue
The request_sock_queue's listen_opt is either vmalloc-ed or
kmalloc-ed depending on the number of table entries. Thus it 
is expected to be handled properly on free, which is done in 
the reqsk_queue_destroy().

However the error path in inet_csk_listen_start() calls 
the lite version of reqsk_queue_destroy, called 
__reqsk_queue_destroy, which calls the kfree unconditionally. 

Fix this and move the __reqsk_queue_destroy into a .c file as 
it looks too big to be inline.

As David also noticed, this is an error recovery path only,
so no locking is required and the lopt is known to be not NULL.

reqsk_queue_yank_listen_sk is also now only used in
net/core/request_sock.c so we should move it there too.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-15 02:57:06 -08:00

249 lines
6.3 KiB
C

/*
* NET Generic infrastructure for Network protocols.
*
* Definitions for request_sock
*
* Authors: Arnaldo Carvalho de Melo <acme@conectiva.com.br>
*
* From code originally in include/net/tcp.h
*
* 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.
*/
#ifndef _REQUEST_SOCK_H
#define _REQUEST_SOCK_H
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <net/sock.h>
struct request_sock;
struct sk_buff;
struct dst_entry;
struct proto;
struct request_sock_ops {
int family;
int obj_size;
struct kmem_cache *slab;
int (*rtx_syn_ack)(struct sock *sk,
struct request_sock *req,
struct dst_entry *dst);
void (*send_ack)(struct sk_buff *skb,
struct request_sock *req);
void (*send_reset)(struct sock *sk,
struct sk_buff *skb);
void (*destructor)(struct request_sock *req);
};
/* struct request_sock - mini sock to represent a connection request
*/
struct request_sock {
struct request_sock *dl_next; /* Must be first member! */
u16 mss;
u8 retrans;
u8 __pad;
/* The following two fields can be easily recomputed I think -AK */
u32 window_clamp; /* window clamp at creation time */
u32 rcv_wnd; /* rcv_wnd offered first time */
u32 ts_recent;
unsigned long expires;
const struct request_sock_ops *rsk_ops;
struct sock *sk;
u32 secid;
u32 peer_secid;
};
static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops)
{
struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC);
if (req != NULL)
req->rsk_ops = ops;
return req;
}
static inline void __reqsk_free(struct request_sock *req)
{
kmem_cache_free(req->rsk_ops->slab, req);
}
static inline void reqsk_free(struct request_sock *req)
{
req->rsk_ops->destructor(req);
__reqsk_free(req);
}
extern int sysctl_max_syn_backlog;
/** struct listen_sock - listen state
*
* @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs
*/
struct listen_sock {
u8 max_qlen_log;
/* 3 bytes hole, try to use */
int qlen;
int qlen_young;
int clock_hand;
u32 hash_rnd;
u32 nr_table_entries;
struct request_sock *syn_table[0];
};
/** struct request_sock_queue - queue of request_socks
*
* @rskq_accept_head - FIFO head of established children
* @rskq_accept_tail - FIFO tail of established children
* @rskq_defer_accept - User waits for some data after accept()
* @syn_wait_lock - serializer
*
* %syn_wait_lock is necessary only to avoid proc interface having to grab the main
* lock sock while browsing the listening hash (otherwise it's deadlock prone).
*
* This lock is acquired in read mode only from listening_get_next() seq_file
* op and it's acquired in write mode _only_ from code that is actively
* changing rskq_accept_head. All readers that are holding the master sock lock
* don't need to grab this lock in read mode too as rskq_accept_head. writes
* are always protected from the main sock lock.
*/
struct request_sock_queue {
struct request_sock *rskq_accept_head;
struct request_sock *rskq_accept_tail;
rwlock_t syn_wait_lock;
u8 rskq_defer_accept;
/* 3 bytes hole, try to pack */
struct listen_sock *listen_opt;
};
extern int reqsk_queue_alloc(struct request_sock_queue *queue,
unsigned int nr_table_entries);
extern void __reqsk_queue_destroy(struct request_sock_queue *queue);
extern void reqsk_queue_destroy(struct request_sock_queue *queue);
static inline struct request_sock *
reqsk_queue_yank_acceptq(struct request_sock_queue *queue)
{
struct request_sock *req = queue->rskq_accept_head;
queue->rskq_accept_head = NULL;
return req;
}
static inline int reqsk_queue_empty(struct request_sock_queue *queue)
{
return queue->rskq_accept_head == NULL;
}
static inline void reqsk_queue_unlink(struct request_sock_queue *queue,
struct request_sock *req,
struct request_sock **prev_req)
{
write_lock(&queue->syn_wait_lock);
*prev_req = req->dl_next;
write_unlock(&queue->syn_wait_lock);
}
static inline void reqsk_queue_add(struct request_sock_queue *queue,
struct request_sock *req,
struct sock *parent,
struct sock *child)
{
req->sk = child;
sk_acceptq_added(parent);
if (queue->rskq_accept_head == NULL)
queue->rskq_accept_head = req;
else
queue->rskq_accept_tail->dl_next = req;
queue->rskq_accept_tail = req;
req->dl_next = NULL;
}
static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue)
{
struct request_sock *req = queue->rskq_accept_head;
BUG_TRAP(req != NULL);
queue->rskq_accept_head = req->dl_next;
if (queue->rskq_accept_head == NULL)
queue->rskq_accept_tail = NULL;
return req;
}
static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue,
struct sock *parent)
{
struct request_sock *req = reqsk_queue_remove(queue);
struct sock *child = req->sk;
BUG_TRAP(child != NULL);
sk_acceptq_removed(parent);
__reqsk_free(req);
return child;
}
static inline int reqsk_queue_removed(struct request_sock_queue *queue,
struct request_sock *req)
{
struct listen_sock *lopt = queue->listen_opt;
if (req->retrans == 0)
--lopt->qlen_young;
return --lopt->qlen;
}
static inline int reqsk_queue_added(struct request_sock_queue *queue)
{
struct listen_sock *lopt = queue->listen_opt;
const int prev_qlen = lopt->qlen;
lopt->qlen_young++;
lopt->qlen++;
return prev_qlen;
}
static inline int reqsk_queue_len(const struct request_sock_queue *queue)
{
return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0;
}
static inline int reqsk_queue_len_young(const struct request_sock_queue *queue)
{
return queue->listen_opt->qlen_young;
}
static inline int reqsk_queue_is_full(const struct request_sock_queue *queue)
{
return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log;
}
static inline void reqsk_queue_hash_req(struct request_sock_queue *queue,
u32 hash, struct request_sock *req,
unsigned long timeout)
{
struct listen_sock *lopt = queue->listen_opt;
req->expires = jiffies + timeout;
req->retrans = 0;
req->sk = NULL;
req->dl_next = lopt->syn_table[hash];
write_lock(&queue->syn_wait_lock);
lopt->syn_table[hash] = req;
write_unlock(&queue->syn_wait_lock);
}
#endif /* _REQUEST_SOCK_H */