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[Ashok Kumar <question266555@xxxxxxxxxxxxxxxxxxxxx>]

Question #266555 on rohc changed:
https://answers.launchpad.net/rohc/+question/266555

    Status: Answered => Open

Ashok Kumar is still having a problem:
Hi,
      I installed the latest version of ROHC from Git as per the instruction given in the link and also enabled non-regression test. Then I used the following code which deliberately takes the fifth packet to de-compressor without being compressed and the error its created also shown


#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<errno.h>
#include<netdb.h>

#include<netinet/ip_icmp.h>   
#include<netinet/udp.h>   
#include<netinet/tcp.h>
#include<netinet/ip.h>
#include<netinet/if_ether.h>
#include<net/ethernet.h>
#include<netinet/in.h>

#include<sys/socket.h>
#include<arpa/inet.h>
#include<sys/ioctl.h>
#include<sys/time.h>
#include<sys/types.h>
#include<unistd.h>

#include<stdarg.h>
#include<rohc/rohc.h>
#include<rohc/rohc_comp.h>
#include<rohc/rohc_decomp.h>
#include<rohc/rohc_time.h>

#define BUFFER_SIZE 65536


//void PrintData(unsigned char* ,int);
static int gen_random_num(const struct rohc_comp *const comp, void *const user_context);
static void print_rohc_traces(void *const priv_ctxt,const rohc_trace_level_t level,const rohc_trace_entity_t entity,
                              const int profile,const char *const format,...);
int raw_sock,i,j;
FILE *logfile;
struct sockaddr_in source,dest;

int main(int argc, char **argv)
{
	int saddr_size, data_size;
	int count = 0;
	struct sockaddr saddr;
	struct in_addr in;
	struct rohc_comp *compressor;
	struct rohc_decomp *decompressor;
	struct rohc_buf *rcvd_feedback = NULL;
	struct rohc_buf *feedback_send = NULL;
	struct rohc_ts rohc_ts;
	int ret;
	unsigned char luchar_RohcDecStatus, luchar_RohcComStatus;
	unsigned int seed;
	size_t i;
	rohc_status_t status;


	unsigned short iphdrlen;
	unsigned int ip_packet_len, rohc_packet_len;
	unsigned char BUFFER[BUFFER_SIZE], rohc_packet[BUFFER_SIZE], op_packet[BUFFER_SIZE];
		
	
	printf("\n Creating ROHC compressor......\n\n");
	compressor = rohc_comp_new2(ROHC_SMALL_CID, ROHC_SMALL_CID_MAX, gen_random_num, NULL);
	if(compressor == NULL)
	{ 
		printf("Failed creating compressor!!\n");
		rohc_comp_free(compressor);
	}
		
	if(!rohc_comp_set_traces_cb2(compressor, NULL,NULL))//if(!rohc_comp_set_traces_cb2(compressor, print_rohc_traces,NULL))
	{
		printf( "Failed to set the compressor callback random numbers!!\n");
		rohc_comp_free(compressor);
	}
	
	printf("Enabling compressor profiles");
	if(!rohc_comp_enable_profiles(compressor, ROHC_PROFILE_UNCOMPRESSED, ROHC_PROFILE_IP, ROHC_PROFILE_UDP, ROHC_PROFILE_TCP, -1))
        {
		printf("Failed to enable the Compressor profiles\n");
		rohc_comp_free(compressor);
	}

	printf("\n Creating ROHC Decompressor.....");
	decompressor=rohc_decomp_new2(ROHC_SMALL_CID, ROHC_SMALL_CID_MAX, ROHC_U_MODE);
	if(decompressor == NULL)
	{
		printf("Failed creating decompressor!!\n");
		rohc_decomp_free(decompressor);
	}

	if(!rohc_decomp_set_traces_cb2(decompressor,NULL,NULL))//if(!rohc_decomp_set_traces_cb2(decompressor,print_rohc_traces,NULL))
	{
		printf("Failed to set callback traces for decompressor!!\n");
		rohc_decomp_free(decompressor);
	} 

	if(!rohc_decomp_enable_profiles(decompressor, ROHC_PROFILE_UNCOMPRESSED, ROHC_PROFILE_IP, ROHC_PROFILE_UDP, ROHC_PROFILE_TCP, -1))
        {
		printf("Failed to enable the De-compressor profiles\n");
		rohc_decomp_free(decompressor);
	}
	
	logfile=fopen("log.txt","w");
	if(logfile == NULL) 
	{
		printf("Unable to create file\n");
	}
	
	raw_sock = socket(AF_PACKET , SOCK_RAW , htons(ETH_P_ALL));
	//setsockopt(raw_sock , SOL_SOCKET , SO_BINDTODEVICE , "eth0" , strlen("eth0")+ 1 );
		
	if(raw_sock < 0)
	{
		perror("\n Socket error-try with sudo");
		return 1;
	}
	while(1)
	{
		saddr_size = sizeof(saddr);
		data_size = recvfrom(raw_sock, BUFFER, BUFFER_SIZE, 0, &saddr, &saddr_size);
		if(data_size < 0)
		{
			printf("\n Error of recvfrom(), failed to get packets");
			return 1;
		}
		
		struct iphdr *iph = (struct iphdr*)(BUFFER + sizeof(struct ethhdr));
		iphdrlen = iph->ihl*4;
		memset(&source, 0, sizeof(source));
		source.sin_addr.s_addr = iph->saddr;
		memset(&dest, 0, sizeof(dest));
		dest.sin_addr.s_addr = iph->daddr;

		if((((unsigned int)iph->protocol)==6||((unsigned int)iph->protocol)==17)&&(strcmp(inet_ntoa(dest.sin_addr),"172.16.18.134")==0))
		{

			count++;			
			
			int ethhdr_size = sizeof(struct ethhdr);
			struct rohc_buf rohcBuf_IpPacket = rohc_buf_init_full(&BUFFER[ethhdr_size], data_size-ethhdr_size , 0);
	    	unsigned char rohc_Combuffer[BUFFER_SIZE];
	    	struct rohc_buf rohc_Compacket = rohc_buf_init_empty(rohc_Combuffer, BUFFER_SIZE);
			if(count!=5)
			{
				printf("\n Compressing the TCP/IP packet...\n\n");				
				luchar_RohcComStatus = rohc_compress4(compressor, rohcBuf_IpPacket, &rohc_Compacket);
			    if(luchar_RohcComStatus!= ROHC_STATUS_OK)
				{
					printf( "Compression of TCP/IP packet failed\n");
					rohc_comp_free(compressor);
					return 1;
				}
				printf("IP packet size=%d ROHC packet size =%d\n", data_size-sizeof(struct ethhdr),rohc_Compacket.len);
			}
	
			
			//if(count!=5)
			//{
				printf("\n Decompressing the TCP/IP packet....\n");				
				struct rohc_buf rohc_packet = rohc_buf_init_full(rohc_Combuffer,rohc_Compacket.len, 0);
				unsigned char rohc_Decombuffer[BUFFER_SIZE];
				struct rohc_buf rohc_Decompacket = rohc_buf_init_empty(rohc_Decombuffer, BUFFER_SIZE);

				luchar_RohcDecStatus = rohc_decompress3(decompressor, rohc_packet, &rohc_Decompacket,
			  	rcvd_feedback, feedback_send);
				if(luchar_RohcDecStatus !=  ROHC_STATUS_OK)
			    {
					printf("Decompression TCP/IP packet failed\n");
		            rohc_decomp_free(decompressor);
			    }
				printf("ROHC packet size=%d IP packet size=%d\n", rohc_Compacket.len,rohc_Decompacket.len);
			//}
	        
		}
		else
		{
			//printf("IP packet received of protocol number:%d\r",(unsigned int)iph->protocol);
		}
		usleep(0);
	}
	close(raw_sock);
	printf("\n Finished");
	printf("\n Destroy the Compressor and Decompressor");
	rohc_comp_free(compressor);
	rohc_decomp_free(decompressor);
	return 0;
}

static int gen_random_num(const struct rohc_comp *const comp,void *const user_context)
{
	return rand();
}

static void print_rohc_traces(void *const priv_ctxt,const rohc_trace_level_t level,const rohc_trace_entity_t entity,const int profile,
	const char *const format,...)
{
        va_list args;
        va_start(args, format);
        vfprintf(stdout, format, args);
        va_end(args);
}

sudo ./ROHCTest

 Creating ROHC compressor......

Enabling compressor profiles
 Creating ROHC Decompressor.....
 Compressing the TCP/IP packet...

IP packet size=618 ROHC packet size =617

 Decompressing the TCP/IP packet....
ROHC packet size=617 IP packet size=618

 Compressing the TCP/IP packet...

IP packet size=52 ROHC packet size =51

 Decompressing the TCP/IP packet....
ROHC packet size=51 IP packet size=52

 Compressing the TCP/IP packet...

IP packet size=593 ROHC packet size =592

 Decompressing the TCP/IP packet....
ROHC packet size=592 IP packet size=593

 Compressing the TCP/IP packet...

IP packet size=613 ROHC packet size =613

 Decompressing the TCP/IP packet....
ROHC packet size=613 IP packet size=613

 Decompressing the TCP/IP packet....
Decompression TCP/IP packet failed
ROHC packet size=0 IP packet size=0

 Compressing the TCP/IP packet...

IP packet size=52 ROHC packet size =27

 Decompressing the TCP/IP packet....
ROHCTest: rohc_decomp.c:3616: rohc_decomp_decode_cid: Assertion `0' failed.
Aborted


But it works like a champ when a compressed packet is purposely discarded in de-compressor without getting aborted...

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