Re: for help

[fan zhang <zf446886@xxxxxxxxx>]

I use the function ssh_channel_pty_window_change_callback（）.but when I
change window size ,it does not work.My test code is below:
#include "config.h"

#include <libssh/libssh.h>
#include <libssh/server.h>
#include <libssh/callbacks.h>

#ifdef HAVE_ARGP_H
#include <argp.h>
#endif
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <poll.h>
#ifdef HAVE_PTY_H
#include <pty.h>
#endif
#ifdef HAVE_UTIL_H
#include <util.h>
#endif
#ifdef HAVE_TERMIOS_H
#include <termios.h>
#endif
#define SSHD_USER "libssh"
#define SSHD_PASSWORD "libssh"

#ifndef KEYS_FOLDER
#ifdef _WIN32
#define KEYS_FOLDER
#else
#define KEYS_FOLDER "/etc/ssh/"
#endif
#endif

static int port = 2222;

#ifdef WITH_PCAP
const char *pcap_file="debug.server.pcap";
ssh_pcap_file pcap;

static void set_pcap(ssh_session session){
if(!pcap_file)
return;
pcap=ssh_pcap_file_new();
if(ssh_pcap_file_open(pcap,pcap_file) == SSH_ERROR){
printf("Error opening pcap file\n");
ssh_pcap_file_free(pcap);
pcap=NULL;
return;
}
ssh_set_pcap_file(session,pcap);
}

static void cleanup_pcap(){
ssh_pcap_file_free(pcap);
pcap=NULL;
}
#endif


static int auth_password(const char *user, const char *password){
    if(strcmp(user, SSHD_USER))
        return 0;
    if(strcmp(password, SSHD_PASSWORD))
        return 0;
    return 1; // authenticated
}
#ifdef HAVE_ARGP_H
const char *argp_program_version = "libssh server example "
  SSH_STRINGIFY(LIBSSH_VERSION);
const char *argp_program_bug_address = "<libssh@xxxxxxxxxx>";

/* Program documentation. */
static char doc[] = "libssh -- a Secure Shell protocol implementation";

/* A description of the arguments we accept. */
static char args_doc[] = "BINDADDR";

/* The options we understand. */
static struct argp_option options[] = {
  {
    .name  = "port",
    .key   = 'p',
    .arg   = "PORT",
    .flags = 0,
    .doc   = "Set the port to bind.",
    .group = 0
  },
  {
    .name  = "hostkey",
    .key   = 'k',
    .arg   = "FILE",
    .flags = 0,
    .doc   = "Set the host key.",
    .group = 0
  },
  {
    .name  = "dsakey",
    .key   = 'd',
    .arg   = "FILE",
    .flags = 0,
    .doc   = "Set the dsa key.",
    .group = 0
  },
  {
    .name  = "rsakey",
    .key   = 'r',
    .arg   = "FILE",
    .flags = 0,
    .doc   = "Set the rsa key.",
    .group = 0
  },
  {
    .name  = "verbose",
    .key   = 'v',
    .arg   = NULL,
    .flags = 0,
    .doc   = "Get verbose output.",
    .group = 0
  },
  {NULL, 0, 0, 0, NULL, 0}
};

/* Parse a single option. */
static error_t parse_opt (int key, char *arg, struct argp_state *state) {
  /* Get the input argument from argp_parse, which we
   * know is a pointer to our arguments structure.
   */
  ssh_bind sshbind = state->input;

  switch (key) {
    case 'p':
      ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_BINDPORT_STR, arg);
      port = atoi(arg);
      break;
    case 'd':
      ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_DSAKEY, arg);
      break;
    case 'k':
      ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_HOSTKEY, arg);
      break;
    case 'r':
      ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_RSAKEY, arg);
      break;
    case 'v':
      ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_LOG_VERBOSITY_STR,
"3");
      break;
    case ARGP_KEY_ARG:
      if (state->arg_num >= 1) {
        /* Too many arguments. */
        argp_usage (state);
      }
      ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_BINDADDR, arg);
      break;
    case ARGP_KEY_END:
      if (state->arg_num < 1) {
        /* Not enough arguments. */
        argp_usage (state);
      }
      break;
    default:
      return ARGP_ERR_UNKNOWN;
  }

  return 0;
}

/* Our argp parser. */
static struct argp argp = {options, parse_opt, args_doc, doc, NULL, NULL,
NULL};
#endif /* HAVE_ARGP_H */

static int authenticate(ssh_session session) {
    ssh_message message;

    do {
        message=ssh_message_get(session);
        if(!message)
            break;
        switch(ssh_message_type(message)){
            case SSH_REQUEST_AUTH:
                switch(ssh_message_subtype(message)){
                    case SSH_AUTH_METHOD_PASSWORD:
                        printf("User %s wants to auth with pass %s\n",
                               ssh_message_auth_user(message),
                               ssh_message_auth_password(message));
                        if(auth_password(ssh_message_auth_user(message),
                           ssh_message_auth_password(message))){
                               ssh_message_auth_reply_success(message,0);
                               ssh_message_free(message);
                               return 1;
                           }
                        ssh_message_auth_set_methods(message,
                                                SSH_AUTH_METHOD_PASSWORD |

SSH_AUTH_METHOD_INTERACTIVE);
                        // not authenticated, send default message
                        ssh_message_reply_default(message);
                        break;

                    case SSH_AUTH_METHOD_NONE:
                    default:
                        printf("User %s wants to auth with unknown auth
%d\n",
                               ssh_message_auth_user(message),
                               ssh_message_subtype(message));
                        ssh_message_auth_set_methods(message,
                                                SSH_AUTH_METHOD_PASSWORD |

SSH_AUTH_METHOD_INTERACTIVE);
                        ssh_message_reply_default(message);
                        break;
                }
                break;
            default:
                ssh_message_auth_set_methods(message,
                                                SSH_AUTH_METHOD_PASSWORD |

SSH_AUTH_METHOD_INTERACTIVE);
                ssh_message_reply_default(message);
        }
        ssh_message_free(message);
    } while (1);
    return 0;
}

static int copy_fd_to_chan(socket_t fd, int revents, void *userdata) {
    ssh_channel chan = (ssh_channel)userdata;
    char buf[2048];
    int sz = 0;

    if(!chan) {
        close(fd);
        return -1;
    }
    if(revents & POLLIN) {
        sz = read(fd, buf, 2048);
        if(sz > 0) {
            ssh_channel_write(chan, buf, sz);
        }
    }
    if(revents & POLLHUP) {
        ssh_channel_close(chan);
        sz = -1;
    }
    return sz;
}

static int copy_chan_to_fd(ssh_session session,
                                           ssh_channel channel,
                                           void *data,
                                           uint32_t len,
                                           int is_stderr,
                                           void *userdata) {
    int fd = *(int*)userdata;
    int sz;
    (void)session;
    (void)channel;
    (void)is_stderr;

    sz = write(fd, data, len);
    return sz;
}

static void chan_close(ssh_session session, ssh_channel channel, void
*userdata) {
    int fd = *(int*)userdata;
    (void)session;
    (void)channel;

    close(fd);
}

int ssh_channel_pty_window_change_callback_test (ssh_session session,
                                            ssh_channel channel,
                                            int width, int height,
                                            int pxwidth, int pwheight,
                                            void *userdata){
printf("win size change\n");
return 1;
}

struct ssh_channel_callbacks_struct cb = {
.channel_pty_window_change_function=ssh_channel_pty_window_change_callback_test,
.channel_data_function = copy_chan_to_fd,
    .channel_eof_function = chan_close,
    .channel_close_function = chan_close,
.userdata = NULL
};


static int main_loop(ssh_channel chan) {
    ssh_session session = ssh_channel_get_session(chan);
    socket_t fd;
    struct termios *term = NULL;
    struct winsize *win = NULL;
    pid_t childpid;
    ssh_event event;
    short events;
    int rc;

    childpid = forkpty(&fd, NULL, term, win);
    if(childpid == 0) {
        execl("/bin/bash", "/bin/bash", (char *)NULL);
        abort();
    }

    cb.userdata = &fd;
    ssh_callbacks_init(&cb);
    ssh_set_channel_callbacks(chan, &cb);


    events = POLLIN | POLLPRI | POLLERR | POLLHUP | POLLNVAL;

    event = ssh_event_new();
    if(event == NULL) {
        printf("Couldn't get a event\n");
        return -1;
    }
    if(ssh_event_add_fd(event, fd, events, copy_fd_to_chan, chan) !=
SSH_OK) {
        printf("Couldn't add an fd to the event\n");
        ssh_event_free(event);
        return -1;
    }
    if(ssh_event_add_session(event, session) != SSH_OK) {
        printf("Couldn't add the session to the event\n");
        ssh_event_remove_fd(event, fd);
        ssh_event_free(event);
        return -1;
    }

    do {
        rc = ssh_event_dopoll(event, 1000);
        if (rc == SSH_ERROR){
            fprintf(stderr, "Error : %s\n", ssh_get_error(session));
            ssh_event_free(event);
            ssh_disconnect(session);
            return -1;
        }
    } while(!ssh_channel_is_closed(chan));

    ssh_event_remove_fd(event, fd);

    ssh_event_remove_session(event, session);

    ssh_event_free(event);
    return 0;
}


int main(int argc, char **argv){
    ssh_session session;
    ssh_bind sshbind;
    ssh_message message;
    ssh_channel chan=0;
    int auth=0;
    int shell=0;
    int r;

    sshbind=ssh_bind_new();

    session=ssh_new();
    ssh_bind_options_set(sshbind,SSH_BIND_OPTIONS_BINDPORT_STR,"2222");
    ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_DSAKEY,
                                            KEYS_FOLDER "ssh_host_dsa_key");
    ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_RSAKEY,
                                            KEYS_FOLDER "ssh_host_rsa_key");

#ifdef HAVE_ARGP_H
    /*
     * Parse our arguments; every option seen by parse_opt will
     * be reflected in arguments.
     */
   // argp_parse (&argp, argc, argv, 0, 0, sshbind);
#else
    (void) argc;
    (void) argv;
#endif
#ifdef WITH_PCAP
    set_pcap(session);
#endif

    if(ssh_bind_listen(sshbind)<0){
        printf("Error listening to socket: %s\n", ssh_get_error(sshbind));
        return 1;
    }
    printf("Started sample libssh sshd on port %d\n", port);
    printf("You can login as the user %s with the password %s\n", SSHD_USER,
                                                            SSHD_PASSWORD);
    r = ssh_bind_accept(sshbind, session);
    if(r==SSH_ERROR){
      printf("Error accepting a connection: %s\n", ssh_get_error(sshbind));
      return 1;
    }
    if (ssh_handle_key_exchange(session)) {
        printf("ssh_handle_key_exchange: %s\n", ssh_get_error(session));
        return 1;
    }

    /* proceed to authentication */
    auth = authenticate(session);
    if(!auth){
        printf("Authentication error: %s\n", ssh_get_error(session));
        ssh_disconnect(session);
        return 1;
    }


    /* wait for a channel session */
    do {

        message = ssh_message_get(session);

        if(message){
            if(ssh_message_type(message) == SSH_REQUEST_CHANNEL_OPEN &&
                    ssh_message_subtype(message) == SSH_CHANNEL_SESSION) {
                chan =
ssh_message_channel_request_open_reply_accept(message);
                ssh_message_free(message);
                break;
            } else {
                ssh_message_reply_default(message);
                ssh_message_free(message);
            }
        } else {
            break;
        }
    } while(!chan);

    if(!chan) {
        printf("Error: cleint did not ask for a channel session (%s)\n",
                                                    ssh_get_error(session));
        ssh_finalize();
        return 1;
    }


    /* wait for a shell */
    do {
        message = ssh_message_get(session);
        if(message != NULL) {
        printf("-------------\n");
            if(ssh_message_type(message) == SSH_REQUEST_CHANNEL) {
                if(ssh_message_subtype(message) ==
SSH_CHANNEL_REQUEST_SHELL) {
                    shell = 1;
                    ssh_message_channel_request_reply_success(message);
                    ssh_message_free(message);
                    break;
                } else if(ssh_message_subtype(message) ==
SSH_CHANNEL_REQUEST_PTY) {
                    ssh_message_channel_request_reply_success(message);
                    ssh_message_free(message);
                    continue;
                }

            }
            ssh_message_reply_default(message);
            ssh_message_free(message);
        } else {
            break;
        }
    } while(!shell);

    if(!shell) {
        printf("Error: No shell requested (%s)\n", ssh_get_error(session));
        return 1;
    }

    printf("it works !\n");

    main_loop(chan);

    ssh_disconnect(session);
    ssh_bind_free(sshbind);
#ifdef WITH_PCAP
    cleanup_pcap();
#endif
    ssh_finalize();
    return 0;
}


2014-03-01 19:37 GMT+08:00 Audrius Butkevicius <
audrius.butkevicius@xxxxxxxxxxxxxxxx>:

> Since your program is a proxy, I think you might not be proxying the
> window resize messages correctly (or maybe not proxying them at all).
>
> Resize messages are part of channel, but they are not passed to channel
> data callback, as they have a separate callback.
>
> I think you might need to implement the window resize callback on the
> server side, and pass the requests on the client side, but its hard to say
> without seeing the code.