linux-kernel 3.5.3Tcp系統調用，源碼分析4-inet_init

inet_init是ipv4的初始化函數，在系統初始化的時候會調用（在哪裡？）

static int __init inet_init(void)

{

struct sk_buff *dummy_skb;

struct inet_protosw *q;

struct list_head *r;

int rc = -EINVAL;

BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));

sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);

if (!sysctl_local_reserved_ports)

goto out;

rc = proto_register(&tcp_prot, 1);

if (rc)

goto out_free_reserved_ports;

rc = proto_register(&udp_prot, 1);

if (rc)

goto out_unregister_tcp_proto;

rc = proto_register(&raw_prot, 1);

if (rc)

goto out_unregister_udp_proto;

rc = proto_register(&ping_prot, 1);

if (rc)

goto out_unregister_raw_proto;

(void)sock_register(&inet_family_ops);

#ifdef CONFIG_SYSCTL

ip_static_sysctl_init();

#endif

tcp_prot.sysctl_mem = init_net.ipv4.sysctl_tcp_mem;

if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)

pr_crit("%s: Cannot add ICMP protocol\n", __func__);

if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)

pr_crit("%s: Cannot add UDP protocol\n", __func__);

if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)

pr_crit("%s: Cannot add TCP protocol\n", __func__);

#ifdef CONFIG_IP_MULTICAST

if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)

pr_crit("%s: Cannot add IGMP protocol\n", __func__);

#endif

for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)

INIT_LIST_HEAD(r);

for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)

inet_register_protosw(q);

arp_init();

ip_init();

tcp_v4_init();

tcp_init();

udp_init();

udplite4_register();

ping_init();

if (icmp_init() < 0)

panic("Failed to create the ICMP control socket.\n");

#if defined(CONFIG_IP_MROUTE)

if (ip_mr_init())

pr_crit("%s: Cannot init ipv4 mroute\n", __func__);

#endif

if (init_ipv4_mibs())

pr_crit("%s: Cannot init ipv4 mibs\n", __func__);

ipv4_proc_init();

ipfrag_init();

dev_add_pack(&ip_packet_type);

rc = 0;

out:

return rc;

out_unregister_raw_proto:

proto_unregister(&raw_prot);

out_unregister_udp_proto:

proto_unregister(&udp_prot);

out_unregister_tcp_proto:

proto_unregister(&tcp_prot);

out_free_reserved_ports:

kfree(sysctl_local_reserved_ports);

goto out;

}

小結

inet_init對ipv4相關的協定進行了初始化，包括tcp，udp，icmp等