Tjyylli

I recently experienced problems establishing an SSH tunnel. It turned out that also neither Apache nor Nginx won't bind to any ports (even as root and/or outside the <1024 range).
From here I got a small test program (right below Sample Code; my version with output below), hoping I could track down the error. However, running ./server 6789 and ./client localhost 6789 (in two terminals on the same machine) gives no errors. There is just no connection, so server blocks in accept():

Server:

socket().

bzero().

htons().

bind().

listen().

Client:

socket().

gethostbyname().

bzero().

bcopy().

htons().

ERROR connecting: Connection timed out

The output statements are mine. They are the only thing I've changed, being printed after each successful command.

Apache and Nginx behave similarly, you just can't connect to the server.
However, with SSH there is an error:

$ ssh -4 -vvv -NL 5901:"$server":5901 "$user@$server"

[...]

debug1: Authentication succeeded (publickey).

Authenticated to <server> ([<ip>]:22).

debug1: Local connections to LOCALHOST:5901 forwarded to remote address <server>:5901

debug3: channel_setup_fwd_listener_tcpip: type 2 wildcard 0 addr NULL

debug1: Local forwarding listening on 127.0.0.1 port 5901.

bind: Cannot assign requested address

channel_setup_fwd_listener_tcpip: cannot listen to port: 5901

Could not request local forwarding.

debug2: fd 3 setting TCP_NODELAY

debug3: ssh_packet_set_tos: set IP_TOS 0x10

debug1: Requesting no-more-sessions@openssh.com

(Without -4, the output is slightly different but basically the same.)

Anki behaves similarly:

$ anki

Exception in thread Thread-1:

Traceback (most recent call last):

  File "threading.py", line 916, in _bootstrap_inner

  File "aqt/mediasrv.py", line 57, in run

  File "socketserver.py", line 453, in __init__

  File "aqt/mediasrv.py", line 38, in server_bind

  File "socketserver.py", line 467, in server_bind

OSError: [Errno 99] Cannot assign requested address

Any idea what's the issue here or how I could track down the error?

With Devuan Jessie it has been working, and also on another PC running Devuan ASCII as well. I already checked if a package is missing that is there on the other installations, but didn't find anything that seemed relevant (I have netbase).

Thanks!

server.cpp:

/* A simple server in the internet domain using TCP

   The port number is passed as an argument */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <sys/types.h> 

#include <sys/socket.h>

#include <netinet/in.h>



void error(const char *msg)

{

    perror(msg);

    exit(1);

}



int main(int argc, char *argv[])

{

    puts("Server:");

    int sockfd, newsockfd, portno;

    socklen_t clilen;

    char buffer[256];

    struct sockaddr_in serv_addr, cli_addr;

    int n;

    if (argc < 2) {

        fprintf(stderr,"ERROR, no port providedn");

        exit(1);

    }

    sockfd = socket(AF_INET, SOCK_STREAM, 0);

    if (sockfd < 0) 

        error("ERROR opening socket");

    puts("socket().");

    bzero((char *) &serv_addr, sizeof(serv_addr));

    puts("bzero().");

    portno = atoi(argv[1]);

    serv_addr.sin_family = AF_INET;

    serv_addr.sin_addr.s_addr = INADDR_ANY;

    serv_addr.sin_port = htons(portno);

    puts("htons().");

    if (bind(sockfd, (struct sockaddr *) &serv_addr,

             sizeof(serv_addr)) < 0) 

        error("ERROR on binding");

    puts("bind().");

    listen(sockfd,5);

    puts("listen().");

    clilen = sizeof(cli_addr);

    newsockfd = accept(sockfd, 

                (struct sockaddr *) &cli_addr, 

                &clilen);

    if (newsockfd < 0) 

        error("ERROR on accept");

    puts("accept().");

    bzero(buffer,256);

    n = read(newsockfd,buffer,255);

    if (n < 0) error("ERROR reading from socket");

    printf("Here is the message: %sn",buffer);

    n = write(newsockfd,"I got your message",18);

    if (n < 0) error("ERROR writing to socket");

    close(newsockfd);

    close(sockfd);

    return 0; 

}

client.cpp:

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <string.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <netdb.h> 



void error(const char *msg)

{

    perror(msg);

    exit(0);

}



int main(int argc, char *argv[])

{

    puts("Client:");



    int sockfd, portno, n;

    struct sockaddr_in serv_addr;

    struct hostent *server;



    char buffer[256];

    if (argc < 3) {

       fprintf(stderr,"usage %s hostname portn", argv[0]);

       exit(0);

    }

    portno = atoi(argv[2]);

    sockfd = socket(AF_INET, SOCK_STREAM, 0);

    if (sockfd < 0) 

        error("ERROR opening socket");

    puts("socket().");

    server = gethostbyname(argv[1]);

    if (server == NULL) {

        fprintf(stderr,"ERROR, no such hostn");

        exit(0);

    }

    puts("gethostbyname().");

    bzero((char *) &serv_addr, sizeof(serv_addr));

    puts("bzero().");

    serv_addr.sin_family = AF_INET;

    bcopy((char *)server->h_addr, 

         (char *)&serv_addr.sin_addr.s_addr,

         server->h_length);

    puts("bcopy().");

    serv_addr.sin_port = htons(portno);

    puts("htons().");

    if (connect(sockfd,(struct sockaddr *) &serv_addr,sizeof(serv_addr)) < 0) 

        error("ERROR connecting");

    printf("Please enter the message: ");

    bzero(buffer,256);

    fgets(buffer,255,stdin);

    n = write(sockfd,buffer,strlen(buffer));

    if (n < 0) 

         error("ERROR writing to socket");

    bzero(buffer,256);

    n = read(sockfd,buffer,255);

    if (n < 0) 

         error("ERROR reading from socket");

    printf("%sn",buffer);

    close(sockfd);

    return 0;

}