"unresolved external function" on RespberryPi

[Han0nly]

Hi,

I'm running picon on a RespberryPi, and I tried a simple example, the code is as follows.

#include <unistd.h> 
#include <stdio.h> 
#include <sys/socket.h> 
#include <stdlib.h> 
#include <netinet/in.h> 
#include <string.h> 
#include <fcntl.h>  

void vulnerable(char *arg) {
    char buff[100];
    printf("%p\n", &buff[0]);
    strcpy(buff, arg);
}

int main(int argc, char const *argv[]) 
{ 
int server_fd, new_socket, valread; 
struct sockaddr_in address; 
int opt = 1, i = 0; 
int addrlen = sizeof(address); 
char recv_msg[1024] = {0}; 
    int port_number;

    // Opt users for entering a port number
    printf("Enter server port number: ");
    scanf("%d", &port_number);
    
    // let's start the server with socket programming
    // Creating socket file descriptor 
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) 
    { 
        perror("socket failed"); 
        exit(EXIT_FAILURE); 
    } 
    
    // Any address that is supported by internet protocol 
    address.sin_family = AF_INET;        

    // accept any type of address (hostname/IPv4/IPv6)     
    address.sin_addr.s_addr = INADDR_ANY;

    // convert integer values to network byte order
    address.sin_port = htons(port_number); 
    
    // Binding the port address with hostname or IP address
    if (bind(server_fd, (struct sockaddr *)&address, sizeof(address))<0) 
    { 
        perror("bind port with the address has been failed"); 
        exit(EXIT_FAILURE); 
    } 

    // listen for connection requests of clients
    if (listen(server_fd, 1) < 0) 
    { 
        perror("listen"); 
        exit(EXIT_FAILURE); 
    } 

    // Server will keep accepting connection requests until stopped forcefully
    while(1)
    {
        if ((new_socket = accept(server_fd, (struct sockaddr *)&address, 
                        (socklen_t*)&addrlen))<0) 
        { 
            perror("Failed to accept a connection"); 
            exit(EXIT_FAILURE); 
        } 

        // read a new socket message of any size
        read( new_socket, recv_msg, sizeof(recv_msg)); 
        
        // Pass the input to the vulnerable function
        vulnerable(recv_msg);
    }

return 0; 
} 

but I get an error like this

[debug]	[monitor]	forking
[debug]	[monitor]	waiting for new module
[debug]	[monitor]	waiting for loading packet
[debug]	[ client]	exec
[debug]	[ client]	sending loading packet (size = 5)
[debug]	[ client]	waiting for monitor to loading packet
[debug]	[monitor]	received CFI_LOADING_MODULE_BEGIN
[debug]	[monitor]	sending monitor to loading packet
[debug]	[monitor]	waiting for loading packet
[debug]	[ client]	sending loading packet (size = 123)
[debug]	[ client]	sending loading packet (size = 49)
[debug]	[monitor]	received CFI_LOADING_SECTION_FUNCTION_ID
[debug]	[ client]	sending loading packet (size = 12)
[debug]	[monitor]	module has 8 function references
[debug]	[ client]	sending loading packet (size = 100)
[debug]	[monitor]		id=     0 main=NO  init=NO  fini=NO  external=NO  name=vulnerable
[debug]	[monitor]		id=     1 main=NO  init=NO  fini=NO  external=YES name=strcpy
[debug]	[ client]	sending loading packet (size = 197)
[debug]	[monitor]		id=     2 main=YES init=NO  fini=NO  external=NO  name=main
[debug]	[ client]	sending loading packet (size = 0)
[debug]	[monitor]		id=     3 main=NO  init=NO  fini=NO  external=YES name=socket
[debug]	[monitor]		id=     4 main=NO  init=NO  fini=NO  external=YES name=bind
[debug]	[ client]	sending loading packet (size = 0)
[debug]	[monitor]		id=     5 main=NO  init=NO  fini=NO  external=YES name=listen
[debug]	[monitor]		id=     6 main=NO  init=NO  fini=NO  external=YES name=accept
[debug]	[ client]	sending signal
[debug]	[monitor]		id=     7 main=NO  init=NO  fini=NO  external=YES name=read
[debug]	[ client]	waiting for answer
[debug]	[monitor]	waiting for loading packet
[debug]	[monitor]	received CFI_LOADING_SECTION_FUNCTION_TRANSITION
[debug]	[monitor]		call from->to =      0 ->      1
[debug]	[monitor]		call from->to =      2 ->      0
[debug]	[monitor]		call from->to =      2 ->      3
[debug]	[monitor]		call from->to =      2 ->      4
[debug]	[monitor]		call from->to =      2 ->      5
[debug]	[monitor]		call from->to =      2 ->      6
[debug]	[monitor]		call from->to =      2 ->      7
[debug]	[monitor]	waiting for loading packet
[debug]	[monitor]	received CFI_LOADING_SECTION_BLOCK_TRANSITION
[debug]	[monitor]	waiting for loading packet
[debug]	[monitor]	received CFI_LOADING_SECTION_BLOCK_TRANSITION
[debug]	[monitor]		jump from->to =      0 ->      1
[debug]	[monitor]		jump from->to =      0 ->      2
[debug]	[monitor]		jump from->to =      2 ->      3
[debug]	[monitor]		jump from->to =      2 ->      4
[debug]	[monitor]		jump from->to =      4 ->      5
[debug]	[monitor]		jump from->to =      4 ->      6
[debug]	[monitor]		jump from->to =      6 ->      7
[debug]	[monitor]		jump from->to =      7 ->      8
[debug]	[monitor]		jump from->to =      7 ->      9
[debug]	[monitor]		jump from->to =      9 ->      7
[debug]	[monitor]	waiting for loading packet
[debug]	[monitor]	received CFI_LOADING_SECTION_BLOCK_IPD
[debug]	[monitor]		function=     0 block=     0 ipd=     0
[debug]	[monitor]		function=     2 block=     0 ipd=     0
[debug]	[monitor]		function=     2 block=     1 ipd=     0
[debug]	[monitor]		function=     2 block=     2 ipd=     0
[debug]	[monitor]		function=     2 block=     3 ipd=     0
[debug]	[monitor]		function=     2 block=     4 ipd=     0
[debug]	[monitor]		function=     2 block=     5 ipd=     0
[debug]	[monitor]		function=     2 block=     6 ipd=     7
[debug]	[monitor]		function=     2 block=     7 ipd=     8
[debug]	[monitor]		function=     2 block=     8 ipd=     0
[debug]	[monitor]		function=     2 block=     9 ipd=     7
[debug]	[monitor]		function=     2 block=    10 ipd=     0
[debug]	[monitor]	waiting for loading packet
[debug]	[monitor]	received CFI_LOADING_MODULE_END
[debug]	[monitor]	computing relocation of module id=0
[debug]	[monitor]		no relocation found for id=1 (name=strcpy)
[debug]	[monitor]		no relocation found for id=3 (name=socket)
[debug]	[monitor]		no relocation found for id=4 (name=bind)
[debug]	[monitor]		no relocation found for id=5 (name=listen)
[debug]	[monitor]		no relocation found for id=6 (name=accept)
[debug]	[monitor]		no relocation found for id=7 (name=read)
[debug]	[monitor]	0 inits are expected
[debug]	[monitor]	waiting for new module
[debug]	[monitor]	waiting for loading packet
[debug]	[monitor]	received CFI_LOADING_TERMINATED
[debug]	[monitor]	computing relocation of module id=0
[debug]	[monitor]		no relocation found for id=1 (name=strcpy)
[error]	[monitor]	unresolved external function : strcpy
[error]	[monitor]	failed to load monitor data
[debug]	[monitor]	exits with status = 1

It seems like a linkage problem. Does anyone know how to fix this problem? Thanks!