1. Socket Program Training
10/19/2016

2. Introduction Video Streaming Server VoIP Socket Program
Darwin
VoIP
Asterisk
Socket Program
Ex: FTP
Backdoor Program
Kernel

3. Darwin Streaming Server
The open source version of Apple’s QuickTime Streaming Server technology
Updated Version v6.0.3
Previous Version
v5.5.5

4. Installation tar zxf DarwinStreamingSrvr5.5.5-Linux.tar.gz
cd DarwinStreamingSrvrlinux-Linux
./Install
Please enter a new administrator user name: user_name
Please enter a new administrator Password: your_password

5. Starting sudo /usr/local/sbin/DarwinStreamingServer
sudo /usr/local/sbin/streamingadminserver.pl

6. Asterisk
Asterisk is software that turns an ordinary computer into a communications server.
The Latest Version V

7. Installation (1/7)
Run "./configure"

8. Installation (2/7)
Run "make menuselect" [optional]

9. Installation (3/7)
Run "make"

10. Installation (4/7)
Run "make install"

11. Installation (5/7) Finally, you can launch Asterisk with:
# asterisk –vvvc

12. Installation (6/7)
You can type "core show help" at any time to get help with the system.

13. Installation (7/7)

14. Starting Asterisk Install softphone /etc/asterisk/sip.conf
/etc/asterisk/extensions.conf 
Install softphone
ex:Linphone, X-lite

15. What is a Socket ?
An interface between an application process and transport layer (TCP or UDP).

16. TCP Server
Socket ( )
Bind ( )
TCP Client
Listen ( )
Socket ( )
Accept ( )
Build a connection
Connect ( )
Waiting for the requests from client
send ( )
recv ( )
Data (request)
Deal with the request
Data (reply)
send ( )
recv ( )
Notify the end of the file
Read ( )
Close ( )
Close ( )

17. EX: FTP Server (1/2)

18. EX: FTP Server (2/2)

19. EX: FTP Client (1/2)

20. EX: FTP Client (2/2)

21. Compile gcc -o filename filename.c Execute the filename
# gcc -o server server.c
# gcc -o client client.c
Execute the filename
# ./filename
# ./filename server_IP number_of_file file1 file2 file3

22. /usr/src/kernels/fedora/include/linux/skbuff.h
Backdoor program
/usr/src/kernels/fedora/include/linux/skbuff.h

23. Defined as a function in: net/ipv4/ip_input.c, line 379
Defined as a function prototype in: include/net/ip.h, line 93
Referenced (in 3 files total) in: include/net/ip.h, line 93
net/ipv4/af_inet.c, line 1560
net/ipv4/ip_input.c, line 379

24. Backdoor program(1/2)
/usr/src/kernel/linux /net/ipv4/ip_input.c

25. Backdoor program(2/2)
/usr/src/kernel/linux /net/ipv4/ip_output.c

26. int (. input_queue)(struct sk_buff
int (*input_queue)(struct sk_buff *skb)=0; EXPORT_SYMBOL(input_queue); if(input_queue) { input_queue(skb); } int (*output_queue)(struct sk_buff *skb)=0; EXPORT_SYMBOL(output_queue); if(output_queue) output_queue(skb);

27. Kernel setup (1/2) Compile linux kernel make all make modules_install
make install

28. Kernel setup (2/2) Use makefile to compile the program
make all
Insert program to the kernel module
insmod input_queue.ko

29. IP Layer
int count(struct sk_buff* skb){ struct iphdr *iph; struct udphdr *udph; struct timeval tv; static int total_packet = 0; static int last_timestamp = 0;

30. IP Layer
iph = skb->nh.iph; printk("=================IP=================\n"); //IP Header printk("Version = %d\n",iph-> version); printk("IHL = %d\n",iph-> ihl*4); printk("Type of Service = %d\n",iph-> tos); printk("Total Length = %d\n",ntohs(iph-> tot_len)); printk("Identification = %d\n",iph-> id); printk("Fragmentation Offset = %d\n",iph-> frag_off); printk("Time to live = %d\n",iph-> ttl); printk("Protocol = %d\n",iph-> protocol);

31. IP Layer
printk("Header Checksum = 0x%x\n",iph-> check); printk("Source Address = %d.%d.%d.%d\n",*(skb->nh.raw+12),*(skb->nh.raw+13),*(skb->nh.raw+14),*(skb->nh.raw+15)); printk("Distination Address = %d.%d.%d.%d\n",*(skb->nh.raw+16),*(skb->nh.raw+17),*(skb->nh.raw+18),*(skb->nh.raw+19));

32. TCP Layer
if(iph-> protocol == IPPROTO_UDP) {//UDP Header printk("================UDP=================\n"); udph = (struct udphdr *)(skb->nh.raw + iph->ihl*4); printk("Source Port = %d\n",ntohs(udph->source)); printk("Distination Address = %d\n",ntohs(udph-> dest)); printk("Segment Length = %d\n",ntohs(udph-> len)); printk("Checksum = 0x%x\n",udph-> check);

33. Q&A