<big id="p1jdp"></big>
      <big id="p1jdp"></big>
      <progress id="p1jdp"><thead id="p1jdp"></thead></progress>
      <progress id="p1jdp"><sub id="p1jdp"></sub></progress>

      <progress id="p1jdp"></progress>

          主页 > 养生保健 > SPARC/Solaris 8下快速终结TCP有限状态机的TIME_WAIT状态

          SPARC/Solaris 8下快速终结TCP有限状态机的TIME_WAIT状态

          发表日期:2020-10-15 | 来源 :澳洲幸运5群 | 点击数: 次 收听:
           

            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。

            /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

            * /usr/include/netinet/in.h

            * 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 recent [lport,fport] state

            30000cc21d0 ::ffff:192.168.5.8 8e0e46dc 8e0e46da 0000064010 3d49e751 3d49e751 0000024820 00583 01460 0 00 00 0 00000000 [23, 4613] TCP_ESTABLISHED

            # skd64 0x30000cc21d0 256

            byteArray [ 256 bytes ] ---->

            0000000000000000 00 00 03 00 00 47 C1 80-00 00 00 00 10 48 18 88 .....G羳.....H.?

            0000000000000010 00 00 00 00 00 00 00 00-00 00 03 00 00 3A 60 80 .............:`�

            0000000000000020 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................

            0000000000000030 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................

            0000000000000040 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................

            0000000000000050 00 00 00 00 00 00 02 47-10 00 00 00 8E 0E 46 DC .......G....?F?

            0000000000000060 00 00 FA 0A 00 00 05 B4-8E 0B 77 07 3D 49 E7 51 ..?...磶.w.=I鏠

            0000000000000070 00 00 60 F4 00 00 00 00-00 00 00 00 00 00 00 00 ..`?...........

            0000000000000080 00 01 00 00 3C 00 00 00-3C 00 00 00 00 00 00 00 ....<...<.......

            0000000000000090 00 00 00 00 00 00 FF FF-C0 A8 05 08 00 00 00 00 ......��括......

            00000000000000A0 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................

            00000000000000B0 00 00 00 00 00 00 FF FF-C0 A8 05 82 12 05 00 17 ......��括.?...

            00000000000000C0 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................

            00000000000000D0 00 00 03 00 00 BB 6F D0-00 04 00 00 00 00 00 00 .....籵?.......

            00000000000000E0 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................

            00000000000000F0 00 00 03 00 00 08 2B 68-00 00 00 00 00 00 00 00 ......+h........

            #

            显然0x30000cc21d0对应着一个tcpb_t结构。

            # adb -k /dev/ksyms /dev/mem

            physmem 3b68

            0x30000cc21d0$

            30000cc21d0: tcp_bind_hash tcp_ptpbhn tcp_conn_hash

            3000047c180 10481888 0

            30000cc21e8: tcp_ptpchn time_wait_next time_wait_prev

            300003a6080 0 0

            30000cc2200: time_wait_expir last_rcv_lbolt tcp_state

            0 0 0

            30000cc2214: tcp_rcv_ws tcp_snd_ws tcp_ts_recent

            0 0 0

            30000cc2220: tcp_rto

            24c

            snd_ts_ok 0

            snd_ws_ok 0

            is_secure 0

            reuseaddr 1

            exclbind 0

            30000cc222c: tcp_snxt tcp_swnd tcp_mss

            8e176ce4 f8dc 5b4

            30000cc2238: tcp_iss tcp_rnxt tcp_rwnd

            8e0b7707 3d49ecf0 60f4

            30000cc2248: tcpb_reflock

            30000cc2248: owner/waiters

            0

            30000cc2250: tcp_refcnt tcpb_vcf tcpb_hops

            1 3c000000 3c

            30000cc225c: tcpb_remote_v6

            30000cc225c: 0 0 ffff c0a80508

            30000cc226c: tcpb_bound_source_v6

            30000cc226c: 0 0 0 0

            30000cc227c: tcpb_ip_src_v6

            30000cc227c: 0 0 ffff c0a80582

            30000cc228c: tcpu_fport tcpu_lport ipsec_out

            1205 17 0

            30000cc2298: ipsec_req_in tcpb_tcp tcpb_ipversion

            0 30000bb6fd0 4

            30000cc22ac: bound_if ownerid

            0 0

            $q

            #

            于是我们可以写这样一个脚本kill_timewait.sh

            --------------------------------------------------------------------------

            #! /sbin/sh

            #

            #

            # @(#)kill_timewait.sh 2002-07-07 NSFocus Copyleft 2002-2012

            #

            # Notice here is copyleft but not copyright, enjoy it by yourself.

            #

            # ------------------------------------------------------------------------

            # File : kill_timewait.sh

            # Platform : SPARC/Solaris 8 64-bit kernel mode

            # Author : NSFocus Security Team

            # :

            # Date : 2002-07-07 12:27

            # Modify :

            # Thanks :cdjohns@nswc-g.arpa for SunOS 4.x implementation

            #

            netstat -na -P tcp -f inet | grep TIME_WAIT

            echo

            echo 'TCPB dest [lport,fport] state'

            echo

            ndd /dev/tcp tcp_status | nawk '{print $1 " " $2 " " $16 $17 " " $18}' | egrep 'TIME_WAIT'

            echo

            /usr/bin/echo 'TCPB address to terminate: \c'

            read tcpb_addr

            echo

            adb -k /dev/ksyms /dev/mem << NSFOCUS_EOF

            $tcpb_addr$

            $q

            NSFOCUS_EOF

            #

            # Check to see if this was the correct address and TCPB. state should be 6

            #

            echo

            echo 'tcp_state = 6 = TCPS_TIME_WAIT'

            /usr/bin/echo 'Is this the correct TCPB (y/n)? \c'

            read answer

            echo

            case $answer in

            [Yy]*)

            ;;

            *)

            echo 'No Changes.'

            exit

            ;;

            esac

            #

            # Kernel Hacking, please. These value are expressed in hexadecimal.

            #

            TIME_WAIT_EXPIRE_OFFSET=0x30

            STATE_OFFSET=0x40

            #

            # This value is expressed in decimal and must be greater than zero.

            #

            TIME_WAIT_EXPIRE=0t06

            #

            # Use adb on kernel to set the tcpb_time_wait_expire=6 and

            # tcpb_state=TCPS_CLOSED (-6)

            #

            adb -kw /dev/ksyms /dev/mem << NSFOCUS_EOF

            $tcpb_addr+$TIME_WAIT_EXPIRE_OFFSET/Z $TIME_WAIT_EXPIRE

            $tcpb_addr+$STATE_OFFSET/W -6

            $q

            NSFOCUS_EOF

            echo

            echo "TIME_WAIT state will disappear."

            echo

            netstat -na -P tcp -f inet | grep TIME_WAIT

            --------------------------------------------------------------------------

            不要设置tcpb_time_wait_expire成零,只要是一个很小的值就可以了。这里必须同

            时设置tcpb_time_wait_expire和tcpb_state,只设置其中一个达不到效果。

            利用adb从TCPS_ESTABLISHED变为TCPS_CLOSE_WAIT,可以使一条TCP连接不再工作,

            但这条连接并未销毁,tcpb_t结构也未删除。

            利用adb从TCPS_ESTABLISHED变为TCPS_CLOSED,会导致整个操作系统崩溃?赡苁窍

            层tcpb_t结构被删除,而上层socket并不了解,出现非法指针。

            简化一下kill_timewait.sh

            --------------------------------------------------------------------------

            #! /sbin/sh

            ndd /dev/tcp tcp_status | nawk '{print $1 " " $2 " " $16 $17 " " $18}' | egrep 'TIME_WAIT'

            echo

            /usr/bin/echo 'TCPB address to terminate: \c'

            read tcpb_addr

            echo

            adb -kw /dev/ksyms /dev/mem << NSFOCUS_EOF

            $tcpb_addr+0x30/Z 0t6

            $tcpb_addr+0x40/W -6

            $q

            NSFOCUS_EOF

            --------------------------------------------------------------------------

            还可以写一个脚本自动清除所有TIME_WAIT状态TCP连接

            --------------------------------------------------------------------------

            #! /sbin/sh

            ndd /dev/tcp tcp_status | nawk '{print $1 " " $2 " " $16 $17 " " $18}' | \

            egrep 'TIME_WAIT' | cut -d' ' -f1 | while read tcpb_addr

            do

            adb -kw /dev/ksyms /dev/mem << NSFOCUS_EOF

            $tcpb_addr+0x30/Z 0t6

            $tcpb_addr+0x40/W -6

          澳洲幸运5群

          养生专题
          明星养生
          微信买马高手群