关于LISTEN队列的问题，请教

R.wen

监听队列上分配的request_sock结构好像没被使用，而在tcp_v4_conn_request()又会重新分配一个这样的结构再插入到这个队列中中。这好像不符合逻辑，也没见到在哪个地方释放。是这样吗？　

int reqsk_queue_alloc(struct request_sock_queue *queue,               unsigned int nr_table_entries) {     size_t lopt_size = sizeof(struct listen_sock);     struct listen_sock *lopt;     nr_table_entries = min_t(u32, nr_table_entries, sysctl_max_syn_backlog);     nr_table_entries = max_t(u32, nr_table_entries, 8);     nr_table_entries = roundup_pow_of_two(nr_table_entries + 1);     lopt_size += nr_table_entries * sizeof(struct request_sock *);     if (lopt_size > PAGE_SIZE)         lopt = __vmalloc(lopt_size,             GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,PAGE_KERNEL);     else         lopt = kzalloc(lopt_size, GFP_KERNEL);     if (lopt == NULL)         return -ENOMEM;     for (lopt->max_qlen_log = 3;          (1 << lopt->max_qlen_log) < nr_table_entries;          lopt->max_qlen_log++);     get_random_bytes(&lopt->hash_rnd, sizeof(lopt->hash_rnd));     rwlock_init(&queue->syn_wait_lock);     queue->rskq_accept_head = NULL;     lopt->nr_table_entries = nr_table_entries;     write_lock_bh(&queue->syn_wait_lock);     queue->listen_opt = lopt;     write_unlock_bh(&queue->syn_wait_lock);     return 0; }

int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) {     struct inet_request_sock *ireq;     struct tcp_options_received tmp_opt;     struct request_sock *req;     __be32 saddr = skb->nh.iph->saddr;     __be32 daddr = skb->nh.iph->daddr;     __u32 isn = TCP_SKB_CB(skb)->when;     struct dst_entry *dst = NULL;     ......         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)         goto drop;     req = reqsk_alloc(&tcp_request_sock_ops);     if (!req)         goto drop;     ......     if (tcp_v4_send_synack(sk, req, dst))         goto drop_and_free;     if (want_cookie) {            reqsk_free(req);     } else {         inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);     }     return 0;     ...... }

[ 本帖最后由 R.wen 于 2007-4-17 18:56 编辑 ]

R.wen

void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,                    unsigned long timeout) {     struct inet_connection_sock *icsk = inet_csk(sk);     struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;     const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,                      lopt->hash_rnd, lopt->nr_table_entries);     reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);     inet_csk_reqsk_queue_added(sk, timeout); } 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); }

[ 本帖最后由 R.wen 于 2007-4-17 18:19 编辑 ]