projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 0e87506f ACM |
1 | /* |
| 2 | * NET Generic infrastructure for Network protocols. | |
| 3 | * | |
| 4 | * Authors: Arnaldo Carvalho de Melo <acme@conectiva.com.br> | |
| 5 | * | |
| 6 | * From code originally in include/net/tcp.h | |
| 7 | * | |
| 8 | * This program is free software; you can redistribute it and/or | |
| 9 | * modify it under the terms of the GNU General Public License | |
| 10 | * as published by the Free Software Foundation; either version | |
| 11 | * 2 of the License, or (at your option) any later version. | |
| 12 | */ | |
| 13 | ||
| 14 | #include <linux/module.h> | |
| 15 | #include <linux/random.h> | |
| 16 | #include <linux/slab.h> | |
| 17 | #include <linux/string.h> | |
| 18 | ||
| 19 | #include <net/request_sock.h> | |
| 20 | ||
| e52c1f17 DM |
21 | /* |
| 22 | * Maximum number of SYN_RECV sockets in queue per LISTEN socket. | |
| 23 | * One SYN_RECV socket costs about 80bytes on a 32bit machine. | |
| 24 | * It would be better to replace it with a global counter for all sockets | |
| 25 | * but then some measure against one socket starving all other sockets | |
| 26 | * would be needed. | |
| 27 | * | |
| 28 | * It was 128 by default. Experiments with real servers show, that | |
| 29 | * it is absolutely not enough even at 100conn/sec. 256 cures most | |
| 30 | * of problems. This value is adjusted to 128 for very small machines | |
| 31 | * (<=32Mb of memory) and to 1024 on normal or better ones (>=256Mb). | |
| 32 | * Further increasing requires to change hash table size. | |
| 33 | */ | |
| 34 | int sysctl_max_syn_backlog = 256; | |
| 35 | EXPORT_SYMBOL(sysctl_max_syn_backlog); | |
| 36 | ||
| 0e87506f ACM |
37 | int reqsk_queue_alloc(struct request_sock_queue *queue, |
| 38 | const int nr_table_entries) | |
| 39 | { | |
| 2ad69c55 | 40 | const int lopt_size = sizeof(struct listen_sock) + |
| 0e87506f | 41 | nr_table_entries * sizeof(struct request_sock *); |
| 2ad69c55 | 42 | struct listen_sock *lopt = kmalloc(lopt_size, GFP_KERNEL); |
| 0e87506f ACM |
43 | |
| 44 | if (lopt == NULL) | |
| 45 | return -ENOMEM; | |
| 46 | ||
| 47 | memset(lopt, 0, lopt_size); | |
| 48 | ||
| 49 | for (lopt->max_qlen_log = 6; | |
| 50 | (1 << lopt->max_qlen_log) < sysctl_max_syn_backlog; | |
| 51 | lopt->max_qlen_log++); | |
| 52 | ||
| 53 | get_random_bytes(&lopt->hash_rnd, sizeof(lopt->hash_rnd)); | |
| 54 | rwlock_init(&queue->syn_wait_lock); | |
| 55 | queue->rskq_accept_head = queue->rskq_accept_head = NULL; | |
| 56 | ||
| 57 | write_lock_bh(&queue->syn_wait_lock); | |
| 58 | queue->listen_opt = lopt; | |
| 59 | write_unlock_bh(&queue->syn_wait_lock); | |
| 60 | ||
| 61 | return 0; | |
| 62 | } | |
| 63 | ||
| 64 | EXPORT_SYMBOL(reqsk_queue_alloc); |