From f7978982d31f67867d8200f9f3102eb423312abc Mon Sep 17 00:00:00 2001

From: Alan Coopersmith <[email protected]>

Date: Tue, 29 Dec 2015 12:50:16 -0800

Subject: [PATCH 04/19] sdtlogin

Adds SDTLOGIN interface, which drops the Xserver to user

perms rather than running as root, for added security on Solaris.

Original date:2008-05-06 owner:yippi type:feature

For the original definition, see Sun ASARC case 1995/390.

For the current implementation in the X server, see sun-src/os/dtlogin.c

and dtlogin-userinfo.patch in open-src/xserver/xorg in the X gate.

---

 common/gdm-common.h         |   5 ++

 daemon/gdm-server.c         |  11 +++++

 daemon/gdm-session-worker.c | 116 ++++++++++++++++++++++++++++++++++++++++++++

 daemon/main.c               |  15 ++++++

 4 files changed, 147 insertions(+)

diff --git a/common/gdm-common.h b/common/gdm-common.h

index 19dbbbb..6ac61c0 100644

--- a/common/gdm-common.h

+++ b/common/gdm-common.h

@@ -42,6 +42,11 @@ GQuark gdm_common_error_quark (void);

 typedef char * (*GdmExpandVarFunc) (const char *var,

                                     gpointer user_data);

+#ifdef __sun

+#define GDM_DT_DIR "/var/dt"

+#define GDM_SDTLOGIN_DIR "/var/dt/sdtlogin"

+#endif

+

 G_BEGIN_DECLS

 int            gdm_wait_on_pid           (int pid);

diff --git a/daemon/gdm-server.c b/daemon/gdm-server.c

index 08f2354..2cec263 100644

--- a/daemon/gdm-server.c

+++ b/daemon/gdm-server.c

@@ -742,6 +742,17 @@ gdm_server_spawn (GdmServer    *server,

                 goto out;

         }

+#if __sun

+        /* Remove old communication pipe, if present */

+        char *display_num = strchr(server->priv->display_name, ':');

+        if (display_num != NULL && display_num[1] != '\0') {

+                char *old_pipe = g_strdup_printf ("%s/%s", GDM_SDTLOGIN_DIR,

+                                                  display_num + 1);

+                VE_IGNORE_EINTR (g_remove (old_pipe));

+                g_free (old_pipe);

+        }

+#endif

+

         env = get_server_environment (server);

         freeme = g_strjoinv (" ", argv);

diff --git a/daemon/gdm-session-worker.c b/daemon/gdm-session-worker.c

index 291caad..93c9e82 100644

--- a/daemon/gdm-session-worker.c

+++ b/daemon/gdm-session-worker.c

@@ -38,6 +38,7 @@

 #include <pwd.h>

 #if __sun

+#include <sys/param.h>

 #define GDM_PAM_QUAL

 #else

 #define GDM_PAM_QUAL const

@@ -2044,6 +2045,115 @@ out:

         return fd;

 }

+#ifdef __sun

+static void

+solaris_xserver_cred (const char *username, struct passwd *passwd_entry,

+                      const char *x11_display_name)

+{

+        FILE *fp;

+        struct stat statbuf;

+        gid_t  groups[NGROUPS_UMAX];

+        char *tmp, *p, pipe[MAXPATHLEN], info[MAXPATHLEN];

+        int display_number = 0;

+        int fd, i;

+        int ngroups;

+

+        if (g_access (passwd_entry->pw_dir, F_OK) != 0) {

+                g_debug ("solaris_xserver_cred: no HOME dir access\n");

+                return;

+        }

+

+        /*

+         * Handshake with server. Make sure it created a pipe.

+         * Open and write.

+         */

+        if ((tmp = strstr (x11_display_name, ":")) != NULL) {

+                tmp++;

+                display_number = g_ascii_strtod (tmp, &p);

+

+                if (errno != 0) {

+                        g_debug ("solaris_xserver_cred: problem getting display number\n");

+                        return;

+                }

+        }

+

+        if (g_stat (GDM_SDTLOGIN_DIR, &statbuf) == 0) {

+                if (! S_ISDIR(statbuf.st_mode)) {

+                        g_debug ("solaris_xserver_cred: %s is not a directory\n",

+                                 GDM_SDTLOGIN_DIR);

+                        return;

+                }

+        } else {

+                g_debug ("solaris_xserver_cred: %s does not exist\n", GDM_SDTLOGIN_DIR);

+                return;

+        }

+

+        snprintf (pipe, sizeof(pipe), "%s/%d", GDM_SDTLOGIN_DIR, display_number);

+        fd = open (pipe, O_RDWR);

+        g_remove (pipe);

+

+        if (fd < 0) {

+                g_debug ("solaris_xserver_cred: could not open %s\n", pipe);

+                return;

+        }

+        if (fstat (fd, &statbuf) == 0 ) {

+                if (! S_ISFIFO(statbuf.st_mode)) {

+                        close (fd);

+                        g_debug ("solaris_xserver_cred: %s is not a pipe\n", pipe);

+                        return;

+                }

+        } else {

+                close (fd);

+                g_debug ("solaris_xserver_cred: %s does not exist\n", pipe);

+                return;

+        }

+        fp = fdopen (fd, "w");

+        if (fp == NULL) {

+                close (fd);

+                g_debug ("solaris_xserver_cred: could not fdopen %s\n", pipe);

+                return;

+        }

+

+        snprintf (info, sizeof(info), "GID=\"%d\"; ", passwd_entry->pw_gid);

+        fputs (info, fp);

+        g_debug ("solaris_xserver_cred: %s\n", info);

+

+        if (initgroups (username, passwd_entry->pw_gid) == -1) {

+                ngroups = 0;

+        } else {

+                ngroups = getgroups (NGROUPS_UMAX, groups);

+        }

+

+        for (i=0; i < ngroups; i++) {

+                snprintf (info, sizeof(info), "G_LIST_ID=\"%u\" ", groups[i]);

+                fputs (info, fp);

+                g_debug ("solaris_xserver_cred: %s\n", info);

+        }

+

+        if (ngroups > 0) {

+                fputc (';', fp);

+        }

+

+        snprintf (info, sizeof(info), " HOME=\"%s\" ", passwd_entry->pw_dir);

+        fputs (info, fp);

+        g_debug ("solaris_xserver_cred: %s\n", info);

+

+        snprintf (info, sizeof(info), " UID=\"%d\" EOF=\"\";", passwd_entry->pw_uid);

+        fputs (info, fp);

+        g_debug ("solaris_xserver_cred: %s\n", info);

+

+        /*

+         * Handshake with server. Make sure it read the pipe.

+         *

+         * Close file descriptor.

+         */

+        fflush (fp);

+        fclose (fp);

+

+        return;

+}

+#endif

+

 static gboolean

 gdm_session_worker_start_session (GdmSessionWorker  *worker,

                                   GError           **error)

@@ -2061,6 +2171,12 @@ gdm_session_worker_start_session (GdmSessionWorker  *worker,

                          worker->priv->arguments[0]);

         }

+#ifdef __sun

+        solaris_xserver_cred (worker->priv->username,

+                              passwd_entry,

+                              worker->priv->x11_display_name);

+#endif

+

         error_code = PAM_SUCCESS;

 #ifdef WITH_SYSTEMD

diff --git a/daemon/main.c b/daemon/main.c

index ca2dda3..50f6e94 100644

--- a/daemon/main.c

+++ b/daemon/main.c

@@ -324,6 +324,21 @@ main (int    argc,

         block_sigusr1 ();

+#ifdef __sun

+        {

+                struct stat statbuf;

+                int r;

+

+                r = stat (GDM_DT_DIR, &statbuf);

+                if (r < 0) {

+                        g_mkdir (GDM_DT_DIR, 0755);

+                }

+

+                g_remove (GDM_SDTLOGIN_DIR);

+                g_mkdir (GDM_SDTLOGIN_DIR, 0700);

+        }

+#endif

+

         bindtextdomain (GETTEXT_PACKAGE, GNOMELOCALEDIR);

         textdomain (GETTEXT_PACKAGE);

         setlocale (LC_ALL, "");

-- 

2.7.4