POTD skeleton #21.

Signed-off-by: Toni Uhlig <matzeton@googlemail.com>

1 files changed, 113 insertions, 0 deletions

diff --git a/src/server_ssh.c b/src/server_ssh.c
index 7082f70..c84f718 100644
--- a/src/server_ssh.c
+++ b/src/server_ssh.c
@@ -38,6 +38,18 @@ static void *
 ssh_thread_mainloop(void *arg);
 static int authenticate(ssh_session session);
 static int auth_password(const char *user, const char *password);
+static int main_loop(ssh_channel chan);
+static int copy_fd_to_chan(socket_t fd, int revents, void *userdata);
+static int copy_chan_to_fd(ssh_session session, ssh_channel channel, void *data,
+                           uint32_t len, int is_stderr, void *userdata);
+static void chan_close(ssh_session session, ssh_channel channel, void *userdata);
+
+struct ssh_channel_callbacks_struct ssh_channel_cb = {
+    .channel_data_function = copy_chan_to_fd,
+    .channel_eof_function = chan_close,
+    .channel_close_function = chan_close,
+    .userdata = NULL
+};
 
 
 int ssh_init_cb(struct forward_ctx *ctx)
@@ -313,6 +325,9 @@ ssh_thread_mainloop(void *arg)
             goto failed;
         }
 
+        N("%s", "Dropping user into shell");
+        main_loop(chan);
+
 failed:
         ssh_disconnect(ses);
         ssh_free(ses);
@@ -387,3 +402,101 @@ static int auth_password(const char *user, const char *password)
 */
     return 1; /* authenticated */
 }
+
+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;
+
+    childpid = forkpty(&fd, NULL, term, win);
+    if (childpid == 0) {
+        execl("/bin/bash", "/bin/bash", (char *)NULL);
+        abort();
+    }
+
+    ssh_channel_cb.userdata = &fd;
+    ssh_callbacks_init(&ssh_channel_cb);
+    ssh_set_channel_callbacks(chan, &ssh_channel_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");
+        return -1;
+    }
+    if (ssh_event_add_session(event, session) != SSH_OK) {
+        printf("Couldn't add the session to the event\n");
+        return -1;
+    }
+
+    do {
+        ssh_event_dopoll(event, 1000);
+    } while(!ssh_channel_is_closed(chan));
+
+    ssh_event_remove_fd(event, fd);
+
+    ssh_event_remove_session(event, session);
+
+    ssh_event_free(event);
+    return 0;
+}
+
+static int copy_fd_to_chan(socket_t fd, int revents, void *userdata)
+{
+    ssh_channel chan = (ssh_channel)userdata;
+    char buf[BUFSIZ];
+    int sz = 0;
+
+    if(!chan) {
+        close(fd);
+        return -1;
+    }
+    if(revents & POLLIN) {
+        sz = read(fd, buf, BUFSIZ);
+        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);
+}