This is an automated email from the git hooks/post-receive script. x2go pushed a commit to branch master in repository libx2goclient. commit 6c8255efdea2f7bb3b80758ed44691ba5ff429e8 Author: Mihai Moldovan <ionic@ionic.de> Date: Thu May 14 22:27:01 2020 +0200 src/x2goclient-network-ssh.{c,h}: implement x2goclient_network_ssh_fetch_openssh_version (). --- src/x2goclient-network-ssh.c | 176 +++++++++++++++++++++++++++++++++++++++++++ src/x2goclient-network-ssh.h | 2 + 2 files changed, 178 insertions(+) diff --git a/src/x2goclient-network-ssh.c b/src/x2goclient-network-ssh.c index 04c03ed..0029d2c 100644 --- a/src/x2goclient-network-ssh.c +++ b/src/x2goclient-network-ssh.c @@ -30,6 +30,7 @@ #include <arpa/inet.h> #include <stdlib.h> #include <errno.h> +#include <limits.h> #include <glib.h> #include <glib/gi18n.h> @@ -122,6 +123,7 @@ static GSocketAddress* x2goclient_network_ssh_parse_sockspec_alias (const GStrin static GSocketAddress* x2goclient_network_ssh_parse_sockspec (X2GoClientNetwork *parent, const GString *sockspec); static gboolean x2goclient_network_ssh_kill_subprocesses (X2GoClientNetworkSSH *self); static gboolean x2goclient_network_ssh_parent_connect (X2GoClientNetwork *parent, GError **gerr); +static gboolean x2goclient_network_ssh_fetch_openssh_version (X2GoClientNetworkSSH *self, GError **gerr); static void x2goclient_network_ssh_class_init (X2GoClientNetworkSSHClass *klass) { @@ -920,3 +922,177 @@ static gboolean x2goclient_network_ssh_parent_connect (X2GoClientNetwork *parent return (ret); } + +static gboolean x2goclient_network_ssh_fetch_openssh_version (X2GoClientNetworkSSH *self, GError **gerr) { + gboolean ret = FALSE; + + g_return_val_if_fail (X2GOCLIENT_IS_NETWORK_SSH (self), ret); + g_return_val_if_fail (((gerr == NULL) || (*gerr == NULL)), ret); + + GPtrArray *ssh_cmd = g_ptr_array_new_with_free_func (&x2goclient_clear_strings); + g_ptr_array_add (ssh_cmd, g_strdup ("ssh")); + g_ptr_array_add (ssh_cmd, g_strdup ("-V")); + g_ptr_array_add (ssh_cmd, NULL); + + { + gchar *tmp = NULL; + for (gsize i = 0; i < ssh_cmd->len; ++i) { + gchar *tmp_old = tmp; + + if (tmp) { + tmp = g_strdup_printf ("%s [%s]", tmp_old, (gchar *)g_ptr_array_index (ssh_cmd, i)); + } + else { + tmp = g_strdup_printf ("[%s]", (gchar *)g_ptr_array_index (ssh_cmd, i)); + } + + g_free (tmp_old); + tmp_old = NULL; + } + + g_log (NULL, G_LOG_LEVEL_DEBUG, "Fetching OpenSSH version via: %s", tmp); + + g_free (tmp); + tmp = NULL; + } + + GError *ssh_err = NULL; + GSubprocess *ssh_proc = g_subprocess_newv ((const gchar* const*)(ssh_cmd->pdata), G_SUBPROCESS_FLAGS_STDOUT_PIPE | G_SUBPROCESS_FLAGS_STDERR_PIPE, &ssh_err); + + ret = (ssh_proc != NULL); + + if (ret) { + g_log (NULL, G_LOG_LEVEL_DEBUG, "OpenSSH version fetching process started/executed successfully!"); + + if (ssh_err) { + g_log (NULL, G_LOG_LEVEL_DEBUG, "Successful execution, but ssh_err set? Weird, here's the message: %s", ssh_err->message); + } + + GCancellable *ssh_proc_comm_cancel = g_cancellable_new (); + g_clear_error (&ssh_err); + + GBytes *ssh_stdout = NULL, *ssh_stderr = NULL; + if (!(g_subprocess_communicate (ssh_proc, NULL, ssh_proc_comm_cancel, &ssh_stdout, &ssh_stderr, &ssh_err))) { + g_propagate_prefixed_error (gerr, ssh_err, "Communication with OpenSSH version fetching subprocess failed: "); + } + else { + gsize ssh_stdout_size = 0, ssh_stderr_size = 0; + const gchar *ssh_stdout_str = g_bytes_get_data (ssh_stdout, &ssh_stdout_size), + *ssh_stderr_str = g_bytes_get_data (ssh_stderr, &ssh_stderr_size); + int ssh_stdout_size_sanitized = 0, ssh_stderr_size_sanitized = 0; + gchar *ssh_stdout_str_sanitized = 0, *ssh_stderr_str_sanitized = NULL; + + /* Sanity check on output size. */ + if (INT_MAX < ssh_stdout_size) { + g_log (NULL, G_LOG_LEVEL_WARNING, "OpenSSH returned more than %d bytes on stdout, this is unusual and will be truncated.", INT_MAX); + + ssh_stdout_size_sanitized = INT_MAX; + } + else { + ssh_stdout_size_sanitized = ssh_stdout_size; + } + + if (ssh_stdout_str) { + /* + * Do NOT use g_strndup () here. + * + * It might sound exactly like what we want, but really isn't. + * + * The issue is that g_strndup () will always allocate an n-bytes-sized + * buffer and optionally pad the string with NULL bytes. + * + * That's not really a problem if the string actually is to be + * truncated, since in that case the result will be smaller than the + * original string anyway, but a huge problem if the string small. + * + * In the latter case, we don't want to create a useless 2 GiB string. + * + * Interestingly, POSIX describes strndup as allocating memory "as if + * by using malloc ()", but doesn't mention the actual resulting size. + * In the informal section, buffer sizes are described as either + * (size + 1) or ((strnlen (s, size)) + 1), which, again, could lead + * to the same problem. + */ + ssh_stdout_str_sanitized = g_strdup_printf ("%.*s", ssh_stdout_size_sanitized, ssh_stdout_str); + } + else { + ssh_stderr_size_sanitized = ssh_stderr_size; + } + + if (INT_MAX < ssh_stderr_size) { + g_log (NULL, G_LOG_LEVEL_WARNING, "OpenSSH returned more than %d bytes on stderr, this is unusual and will be truncated.", INT_MAX); + + ssh_stderr_size_sanitized = INT_MAX; + } + + if (ssh_stderr_str) { + ssh_stderr_str_sanitized = g_strdup_printf ("%.*s", ssh_stderr_size_sanitized, ssh_stderr_str); + } + + g_log (NULL, G_LOG_LEVEL_DEBUG, "Stdout:\n>>>%.*s<<<\nStderr:\n>>>%.*s<<<", ssh_stdout_size_sanitized, ssh_stdout_str_sanitized, ssh_stderr_size_sanitized, ssh_stderr_str_sanitized); + + if (ssh_stdout_size_sanitized) { + g_log (NULL, G_LOG_LEVEL_WARNING, "OpenSSH version command wrote data on stdout, this is unexpected and will be ignored.\nData: %*.s", ssh_stdout_size_sanitized, ssh_stdout_str_sanitized); + } + + if (!(ssh_stderr_size_sanitized)) { + g_set_error_literal (gerr, X2GOCLIENT_NETWORK_SSH_ERROR, X2GOCLIENT_NETWORK_SSH_ERROR_OPENSSH_VERSION_NO_STDERR, "OpenSSH version command wrote nothing to stderr, this is unexpected. Can't parse version string."); + ret = FALSE; + } + else { + X2GoClientOpenSSHVersion *version = x2goclient_openssh_version_new (); + + if (!(version)) { + g_set_error_literal (gerr, X2GOCLIENT_NETWORK_SSH_ERROR, X2GOCLIENT_NETWORK_SSH_ERROR_OPENSSH_VERSION_ALLOCATE, "Unable to allocate buffe for OpenSSH version structure - memory issues?"); + ret = FALSE; + } + else { + /* gerr is supposed to be empty at that point. */ + g_assert ((gerr == NULL) || (*gerr == NULL)); + + ret = x2goclient_openssh_version_parse (version, ssh_stderr_str_sanitized, gerr); + + if (ret) { + /* Everything went well, copy to the property. + * + * ... unfortunately, the actual property is read-only (which + * totally makes sense because we only want this class to handle + * it), so we'll have to duplicate a bit of code and can't use the + * GObject property setter directly. + */ + x2goclient_openssh_version_free (self->openssh_version); + self->openssh_version = version; + } + else { + /* Get rid of the version struct. It's bogus anyway. */ + x2goclient_openssh_version_free (version); + } + + version = NULL; + } + } + + g_free (ssh_stdout_str_sanitized); + g_free (ssh_stderr_str_sanitized); + + g_bytes_unref (ssh_stdout); + g_bytes_unref (ssh_stderr); + } + + g_clear_object (&ssh_proc_comm_cancel); + ssh_proc_comm_cancel = NULL; + } + else { + g_propagate_prefixed_error (gerr, ssh_err, "OpenSSH vesion fetching process didn't execute/start successfully! Error: "); + } + + g_clear_error (&ssh_err); + + g_clear_object (&ssh_proc); + ssh_proc = NULL; + + g_ptr_array_unref (ssh_cmd); + ssh_cmd = NULL; + + return (ret); +} diff --git a/src/x2goclient-network-ssh.h b/src/x2goclient-network-ssh.h index cd3f99f..3e5ce29 100644 --- a/src/x2goclient-network-ssh.h +++ b/src/x2goclient-network-ssh.h @@ -66,6 +66,8 @@ enum { X2GOCLIENT_NETWORK_SSH_ERROR_CONNECT_INET_ADDR_NULL, X2GOCLIENT_NETWORK_SSH_ERROR_CONNECT_NATIVE_FETCH, X2GOCLIENT_NETWORK_SSH_ERROR_CONNECT_SOCK_ADDR_UNKNOWN, + X2GOCLIENT_NETWORK_SSH_ERROR_OPENSSH_VERSION_NO_STDERR, + X2GOCLIENT_NETWORK_SSH_ERROR_OPENSSH_VERSION_ALLOCATE, }; -- Alioth's /home/x2go-admin/maintenancescripts/git/hooks/post-receive-email on /srv/git/code.x2go.org/libx2goclient.git