我们这里讨论的是在程序不可控的情况下，比如别人的程序，又未使用SO_REUSEADDR选项，如何快 速终结TCP有限状态机的TIME_WAIT状态。
参看这个链接"closing half-open connections"
http://www-mice.cs.ucl.ac.uk/multimedia/misc/tcp_ip/8707.mm.www/0009.html
1987年10月1日(可真够早的)cdjohns@nswc-g.arpa提供了一个shell script，用于
SunOS 4.x系统下快速终结TCP有限状态机的TIME_WAIT状态。很奇怪，这个脚本并未
得到人们的足够重视并广泛流传，直到SunOS 4.x退出历史舞台，它也就销声匿迹了。
昨天被backend从故纸堆里翻了出来，我们就趁机移植到SPARC/Solaris 8下来。
参看UNP 图2.4了解TCP有限状态机的变迁过程。
/usr/include/netinet里的文件多是为用户空间编程准备的，/usr/include/inet里
的文件多是为内核空间编程准备的。下面内容取自SPARC/Solaris 8
--------------------------------------------------------------------------
/*
* /usr/include/inet/tcp.h
*/
/*
* TCP states
*/
#define TCPS_CLOSED -6
#define TCPS_IDLE -5 /* idle (opened, but not bound) */
#define TCPS_BOUND -4 /* bound, ready to connect or accept */
#define TCPS_LISTEN -3 /* listening for connection */
#define TCPS_SYN_SENT -2 /* active, have sent syn */
#define TCPS_SYN_RCVD -1 /* have received syn (and sent ours) */
/*
* states < TCPS_ESTABLISHED are those where connections not established
*/
#define TCPS_ESTABLISHED 0 /* established */
#define TCPS_CLOSE_WAIT 1 /* rcvd fin, waiting for close */
/*
* states > TCPS_CLOSE_WAIT are those where user has closed
*/
#define TCPS_FIN_WAIT_1 2 /* have closed and sent fin */
#define TCPS_CLOSING 3 /* closed, xchd FIN, await FIN ACK */
#define TCPS_LAST_ACK 4 /* had fin and close; await FIN ACK */
/*
* states > TCPS_CLOSE_WAIT && < TCPS_FIN_WAIT_2 await ACK of FIN
*/
#define TCPS_FIN_WAIT_2 5 /* have closed, fin is acked */
#define TCPS_TIME_WAIT 6 /* in 2*msl quiet wait after close */
#if (defined(_KERNEL) || defined(_KMEMUSER))
/*
* If the information represented by the field is required even in the
* TIME_WAIT state, it must be part of tcpb_t. Otherwise it must be part
* of tcp_t. In other words, the tcp_t captures the information that is
* not required, after a connection has entered the TIME_WAIT state.
*/
typedef struct tcp_base_s
{
struct tcp_base_s *tcpb_bind_hash; /* Bind hash chain */
struct tcp_base_s **tcpb_ptpbhn; /* Pointer to previous bind hash next. */
struct tcp_base_s *tcpb_conn_hash; /* Connect hash chain */
struct tcp_base_s **tcpb_ptpchn; /* Pointer to previous conn hash next. */
struct tcp_base_s *tcpb_time_wait_next; /* Pointer to next T/W block */
struct tcp_base_s *tcpb_time_wait_prev; /* Pointer to previous T/W next */
/*
* /usr/include/sys/types.h
* typedef long clock_t;
* offset: 8 * 6 -> 48 -> 0x30，clock_t占8个字节(64-bit kernel mode)
*/
clock_t tcpb_time_wait_expire; /* time in hz when t/w expires */
clock_t tcpb_last_rcv_lbolt; /* lbolt on last packet, used for PAWS */
/*
* offset: 0x40
*/
int32_t tcpb_state;
int32_t tcpb_rcv_ws; /* My window scale power */
int32_t tcpb_snd_ws; /* Sender's window scale power */
uint32_t tcpb_ts_recent; /* Timestamp of earliest unacked */
/*
* data segment
* offset: 0x50
*/
clock_t tcpb_rto; /* Round trip timeout */
uint32_t tcpb_snd_ts_ok : 1,
tcpb_snd_ws_ok : 1,
tcpb_is_secure : 1,
tcpb_reuseaddr : 1, /* SO_REUSEADDR "socket" option. */
tcpb_exclbind : 1, /* ``exclusive'' binding */
tcpb_junk_fill_thru_bit_31 : 27;
/*
* offset: 0x5c
*/
uint32_t tcpb_snxt; /* Senders next seq num */
uint32_t tcpb_swnd; /* Senders window (relative to suna) */
uint32_t tcpb_mss; /* Max segment size */
uint32_t tcpb_iss; /* Initial send seq num */
/*
* offset: 0x6c
*/
uint32_t tcpb_rnxt; /* Seq we expect to recv next */
uint32_t tcpb_rwnd; /* Current receive window */
/*
* /usr/include/sys/mutex.h
* 无论64-bit还是32-bit kernel mode，kmutex_t都占8字节空间，这里需要对
* 齐在数据类型自然连界上，0x6c + 8 -> 0x74不在kmutex_t自然边界上，继
* 续后移4个字节
*
* offset: 0x78
*/
kmutex_t tcpb_reflock; /* Protects tcp_refcnt */
/*
* offset: 0x80
*/
ushort_t tcpb_refcnt; /* Number of pending upstream msg */
union
{
struct
{
uchar_t v4_ttl; /* Dup of tcp_ipha.iph_type_of_service */
uchar_t v4_tos; /* Dup of tcp_ipha.iph_ttl */
} v4_hdr_info;
struct
{
/*
* 对齐在uint_t的自然边界上
* offset: 0x84
*/
uint_t v6_vcf; /* Dup of tcp_ip6h.ip6h_vcf */
/*
* offset: 0x88
*/
uchar_t v6_hops; /* Dup of tcp_ip6h.ip6h_hops */
} v6_hdr_info;
} tcpb_hdr_info;
#define tcpb_ttl tcpb_hdr_info.v4_hdr_info.v4_ttl
#define tcpb_tos tcpb_hdr_info.v4_hdr_info.v4_tos
#define tcpb_ip6_vcf tcpb_hdr_info.v6_hdr_info.v6_vcf
#define tcpb_ip6_hops tcpb_hdr_info.v6_hdr_info.v6_hops
/*
* offset: 0x8c，先是远端地址，后是本地地址
* in6_addr_t长16字节，在内核空间里这个结构对齐在uint32_t的自然边界上
*/
in6_addr_t tcpb_remote_v6; /* true remote address - needed for */
/* source routing. */
in6_addr_t tcpb_bound_source_v6; /* IP address in bind_req */
/*
* offset: 0xac
*/
in6_addr_t tcpb_ip_src_v6; /* same as tcp_iph.iph_src. */
#ifdef _KERNEL
/*
* Note: V4_PART_OF_V6 is meant to be used only for _KERNEL defined stuff
*/
#define tcpb_remote V4_PART_OF_V6(tcpb_remote_v6)
#define tcpb_bound_source V4_PART_OF_V6(tcpb_bound_source_v6)
#define tcpb_ip_src V4_PART_OF_V6(tcpb_ip_src_v6)
#endif /* _KERNEL */
/*
* These fields contain the same information as tcp_tcph->th_*port.
* However, the lookup functions can not use the header fields
* since during IP option manipulation the tcp_tcph pointer
* changes.
*/
/*
* offset: 0xbc，先是远端端口，后是本地端口
*/
union
{
struct
{
in_port_t tcpu_fport; /* Remote port */
in_port_t tcpu_lport; /* Local port */
} tcpu_ports1;
uint32_t tcpu_ports2; /* Rem port, local port */
/*
* Used for TCP_MATCH performance
*/
} tcpb_tcpu;
#define tcpb_fport tcpb_tcpu.tcpu_ports1.tcpu_fport
#define tcpb_lport tcpb_tcpu.tcpu_ports1.tcpu_lport
#define tcpb_ports tcpb_tcpu.tcpu_ports2
/*
* IP sends back 2 mblks with the unbind ACK for handling
* IPSEC policy for detached connections. Following two fields
* are initialized then.
*/
mblk_t *tcpb_ipsec_out;
mblk_t *tcpb_ipsec_req_in;
/*
* offset: 0xd0
*/
tcp_t *tcpb_tcp;
/*
* offset: 0xd8
*/
/*
* IP format that packets transmitted from this struct should use.
* Value can be IPV4_VERSION or IPV6_VERSION. Determines whether
* IP+TCP header template above stores an IPv4 or IPv6 header.
*/
ushort_t tcpb_ipversion;
uint_t tcpb_bound_if; /* IPV6_BOUND_IF */
uid_t tcpb_ownerid; /* uid of process that did open */
#define tcp_bind_hash tcp_base->tcpb_bind_hash
#define tcp_ptpbhn tcp_base->tcpb_ptpbhn
#define tcp_conn_hash tcp_base->tcpb_conn_hash
#define tcp_ptpchn tcp_base->tcpb_ptpchn
#define tcp_time_wait_next tcp_base->tcpb_time_wait_next
#define tcp_time_wait_prev tcp_base->tcpb_time_wait_prev
#define tcp_time_wait_expire tcp_base->tcpb_time_wait_expire
#define tcp_last_rcv_lbolt tcp_base->tcpb_last_rcv_lbolt
#define tcp_state tcp_base->tcpb_state
#define tcp_rcv_ws tcp_base->tcpb_rcv_ws
#define tcp_snd_ws tcp_base->tcpb_snd_ws
#define tcp_ts_recent tcp_base->tcpb_ts_recent
#define tcp_rto tcp_base->tcpb_rto
#define tcp_snd_ts_ok tcp_base->tcpb_snd_ts_ok
#define tcp_snd_ws_ok tcp_base->tcpb_snd_ws_ok
#define tcp_is_secure tcp_base->tcpb_is_secure
#define tcp_snxt tcp_base->tcpb_snxt
#define tcp_swnd tcp_base->tcpb_swnd
#define tcp_mss tcp_base->tcpb_mss
#define tcp_iss tcp_base->tcpb_iss
#define tcp_rnxt tcp_base->tcpb_rnxt
#define tcp_rwnd tcp_base->tcpb_rwnd
#define tcp_reflock tcp_base->tcpb_reflock
#define tcp_refcnt tcp_base->tcpb_refcnt
#define tcp_remote_v6 tcp_base->tcpb_remote_v6
#define tcp_remote tcp_base->tcpb_remote
#define tcp_bound_source_v6 tcp_base->tcpb_bound_source_v6
#define tcp_bound_source tcp_base->tcpb_bound_source
#define tcp_lport tcp_base->tcpb_tcpu.tcpu_ports1.tcpu_lport
#define tcp_fport tcp_base->tcpb_tcpu.tcpu_ports1.tcpu_fport
#define tcp_ports tcp_base->tcpb_tcpu.tcpu_ports2
#define tcp_ipsec_out tcp_base->tcpb_ipsec_out
#define tcp_ipsec_req_in tcp_base->tcpb_ipsec_req_in
#define tcp_ipversion tcp_base->tcpb_ipversion
#define tcp_bound_if tcp_base->tcpb_bound_if
#define tcp_reuseaddr tcp_base->tcpb_reuseaddr
#define tcp_exclbind tcp_base->tcpb_exclbind
#define tcp_ownerid tcp_base->tcpb_ownerid
} tcpb_t;
#endif /* (defined(_KERNEL) || defined(_KMEMUSER)) */
--------------------------------------------------------------------------
下面这两条命令其实是用分号连在一起执行的，否则前后数据不对应，我是telnet上
去执行命令。
# ndd /dev/tcp tcp_status | grep ESTABLISHED
TCPB dest snxt suna swnd rnxt rack rwnd rto mss w sw rw t rece
