如何用C语言编程实现SCTP校验和非零
我编写了一个简单的SCTP客户机/服务器,并通过Wireshark观察到SCTP握手。Wireshark中所有SCTP数据包的校验和始终为零 如何生成非零SCTP校验和 以下是Ubuntu 18.04上安装的库如何用C语言编程实现SCTP校验和非零,c,sockets,network-programming,sctp,C,Sockets,Network Programming,Sctp,我编写了一个简单的SCTP客户机/服务器,并通过Wireshark观察到SCTP握手。Wireshark中所有SCTP数据包的校验和始终为零 如何生成非零SCTP校验和 以下是Ubuntu 18.04上安装的库 libsctp-dev:amd64 1.0.17+dfsg-2 libsctp1:amd64 1.0.17+dfsg-2 lksctp-tools 1.0.17+dfsg-2 sctpserver.c #include <stdio.h&
libsctp-dev:amd64 1.0.17+dfsg-2
libsctp1:amd64 1.0.17+dfsg-2
lksctp-tools 1.0.17+dfsg-2
sctpserver.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/sctp.h>
#include <arpa/inet.h>
int main(int argc, char** argv)
{
int sockfd, client_sockfd;
struct sockaddr_in serv_addr, client_addr;
struct sctp_initmsg initmsg;
int len;
int addr_count = 1;
sockfd = socket(AF_INET,SOCK_STREAM,IPPROTO_SCTP);
if(sockfd < 0)
{
fprintf(stderr,"socket descriptor is invalid.");
exit(1);
}
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = INADDR_ANY;
serv_addr.sin_port = htons(12345);
int brst = sctp_bindx(sockfd,(struct sockaddr*)&serv_addr,addr_count,SCTP_BINDX_ADD_ADDR);
if(brst == -1)
{
fprintf(stderr,"error while binding address.");
exit(1);
}
memset(&initmsg,0,sizeof(initmsg));
initmsg.sinit_max_instreams = 2;
initmsg.sinit_num_ostreams = 2;
brst = setsockopt(sockfd,IPPROTO_SCTP,SCTP_INITMSG,&initmsg,sizeof(initmsg));
if(brst != 0)
{
fprintf(stderr,"error while setting sctp options.\n");
exit(1);
}
listen(sockfd,5);
while (1)
{
len = sizeof(client_addr);
client_sockfd = accept(sockfd, (struct sockaddr*)&client_addr, &len);
if(client_sockfd == -1)
{
fprintf(stderr,"error while accepting connection, continue.\n");
continue;
}
else
{
printf("New client\n");
close(client_sockfd);
}
}
}
钢丝鲨
Frame 828: 100 bytes on wire (800 bits), 100 bytes captured (800 bits)
Linux cooked capture
Internet Protocol Version 4, Src: 192.168.1.197, Dst: 192.168.1.197
Stream Control Transmission Protocol, Src Port: 49208 (49208), Dst Port: 12345 (12345)
Source port: 49208
Destination port: 12345
Verification tag: 0x00000000
[Association index: 0]
Checksum: 0x00000000 [unverified]
[Checksum Status: Unverified]
INIT chunk (Outbound streams: 10, inbound streams: 65535)
Chunk type: INIT (1)
0... .... = Bit: Stop processing of the packet
.0.. .... = Bit: Do not report
Chunk flags: 0x00
Chunk length: 52
Initiate tag: 0xd15eb4e4
Advertised receiver window credit (a_rwnd): 106496
Number of outbound streams: 10
Number of inbound streams: 65535
Initial TSN: 1069541083
IPv4 address parameter (Address: 192.168.1.197)
IPv4 address parameter (Address: 172.17.0.1)
Supported address types parameter (Supported types: IPv4)
ECN parameter
Forward TSN supported parameter
您有可能在linux内核中禁用了SCTP校验和,如本文所述。要验证这一点,请运行命令
sysctl/sys/module/sctp/parameters/sctp\u checksum\u disable
。如果输出为1
,则将其更改为0
,然后重试测试 如本文所述,您有可能在linux内核中禁用了SCTP校验和。要验证这一点,请运行命令sysctl/sys/module/sctp/parameters/sctp\u checksum\u disable
。如果输出为1
,则将其更改为0
,然后重试测试 @John Kugelman,对不起,我编辑了问题并添加了更多细节。谢谢您的编辑!我投票决定重新讨论这个问题。请耐心等待--重新打开可能需要一些时间。@John Kugelman,很抱歉我编辑了问题并添加了更多细节。谢谢编辑!我投票决定重新讨论这个问题。请耐心等待,重新打开可能需要一段时间。
$ gcc sctp-server.c -lsctp -o server
$ gcc sctp-client.c -lsctp -o client
Frame 828: 100 bytes on wire (800 bits), 100 bytes captured (800 bits)
Linux cooked capture
Internet Protocol Version 4, Src: 192.168.1.197, Dst: 192.168.1.197
Stream Control Transmission Protocol, Src Port: 49208 (49208), Dst Port: 12345 (12345)
Source port: 49208
Destination port: 12345
Verification tag: 0x00000000
[Association index: 0]
Checksum: 0x00000000 [unverified]
[Checksum Status: Unverified]
INIT chunk (Outbound streams: 10, inbound streams: 65535)
Chunk type: INIT (1)
0... .... = Bit: Stop processing of the packet
.0.. .... = Bit: Do not report
Chunk flags: 0x00
Chunk length: 52
Initiate tag: 0xd15eb4e4
Advertised receiver window credit (a_rwnd): 106496
Number of outbound streams: 10
Number of inbound streams: 65535
Initial TSN: 1069541083
IPv4 address parameter (Address: 192.168.1.197)
IPv4 address parameter (Address: 172.17.0.1)
Supported address types parameter (Supported types: IPv4)
ECN parameter
Forward TSN supported parameter