/*
 * Copyright (c) 1992, Mark D. Baushke
 *
 * You may distribute under the terms of the GNU General Public License as
 * specified in the README file that comes with the CVS source distribution.
 * 
 * Name of Root
 * 
 * Determine the path to the CVSROOT and set "Root" accordingly.
 */

#include "cvs.h"
#include "getline.h"

/* Printable names for things in the CVSroot_method enum variable.
   Watch out if the enum is changed in cvs.h! */

char *method_names[] = {
    "local", "server (rsh)", "pserver", "kserver", "gserver", "ext", "fork"
};

#ifndef DEBUG

char *
Name_Root (dir, update_dir)
    char *dir;
    char *update_dir;
{
    FILE *fpin;
    char *ret, *xupdate_dir;
    char *root = NULL;
    size_t root_allocated = 0;
    char *tmp;
    char *cvsadm;
    char *cp;

    if (update_dir && *update_dir)
	xupdate_dir = update_dir;
    else
	xupdate_dir = ".";

    if (dir != NULL)
    {
	cvsadm = xmalloc (strlen (dir) + sizeof (CVSADM) + 10);
	(void) sprintf (cvsadm, "%s/%s", dir, CVSADM);
	tmp = xmalloc (strlen (dir) + sizeof (CVSADM_ROOT) + 10);
	(void) sprintf (tmp, "%s/%s", dir, CVSADM_ROOT);
    }
    else
    {
	cvsadm = xstrdup (CVSADM);
	tmp = xstrdup (CVSADM_ROOT);
    }

    /*
     * Do not bother looking for a readable file if there is no cvsadm
     * directory present.
     *
     * It is possible that not all repositories will have a CVS/Root
     * file. This is ok, but the user will need to specify -d
     * /path/name or have the environment variable CVSROOT set in
     * order to continue.  */
    if ((!isdir (cvsadm)) || (!isreadable (tmp)))
    {
	ret = NULL;
	goto out;
    }

    /*
     * The assumption here is that the CVS Root is always contained in the
     * first line of the "Root" file.
     */
    fpin = open_file (tmp, "r");

    if (getline (&root, &root_allocated, fpin) < 0)
    {
	/* FIXME: should be checking for end of file separately; errno
	   is not set in that case.  */
	error (0, 0, "in directory %s:", xupdate_dir);
	error (0, errno, "cannot read %s", CVSADM_ROOT);
	error (0, 0, "please correct this problem");
	ret = NULL;
	goto out;
    }
    (void) fclose (fpin);
    if ((cp = strrchr (root, '\n')) != NULL)
	*cp = '\0';			/* strip the newline */

    /*
     * root now contains a candidate for CVSroot. It must be an
     * absolute pathname or specify a remote server.
     */

    if (
#ifdef CLIENT_SUPPORT
	(strchr (root, ':') == NULL) &&
#endif
    	! isabsolute (root))
    {
	error (0, 0, "in directory %s:", xupdate_dir);
	error (0, 0,
	       "ignoring %s because it does not contain an absolute pathname.",
	       CVSADM_ROOT);
	ret = NULL;
	goto out;
    }

#ifdef CLIENT_SUPPORT
    if ((strchr (root, ':') == NULL) && !isdir (root))
#else /* ! CLIENT_SUPPORT */
    if (!isdir (root))
#endif /* CLIENT_SUPPORT */
    {
	error (0, 0, "in directory %s:", xupdate_dir);
	error (0, 0,
	       "ignoring %s because it specifies a non-existent repository %s",
	       CVSADM_ROOT, root);
	ret = NULL;
	goto out;
    }

    /* allocate space to return and fill it in */
    strip_trailing_slashes (root);
    ret = xstrdup (root);
 out:
    free (cvsadm);
    free (tmp);
    if (root != NULL)
	free (root);
    return (ret);
}

/*
 * Write the CVS/Root file so that the environment variable CVSROOT
 * and/or the -d option to cvs will be validated or not necessary for
 * future work.
 */
void
Create_Root (dir, rootdir)
    char *dir;
    char *rootdir;
{
    FILE *fout;
    char *tmp;

    if (noexec)
	return;

    /* record the current cvs root */

    if (rootdir != NULL)
    {
        if (dir != NULL)
	{
	    tmp = xmalloc (strlen (dir) + sizeof (CVSADM_ROOT) + 10);
	    (void) sprintf (tmp, "%s/%s", dir, CVSADM_ROOT);
	}
        else
	    tmp = xstrdup (CVSADM_ROOT);

        fout = open_file (tmp, "w+");
        if (fprintf (fout, "%s\n", rootdir) < 0)
	    error (1, errno, "write to %s failed", tmp);
        if (fclose (fout) == EOF)
	    error (1, errno, "cannot close %s", tmp);
	free (tmp);
    }
}

#endif /* ! DEBUG */


/* The root_allow_* stuff maintains a list of legal CVSROOT
   directories.  Then we can check against them when a remote user
   hands us a CVSROOT directory.  */

static unsigned int root_allow_count;
static char **root_allow_vector;
static unsigned int root_allow_size;

void
root_allow_add (arg)
    char *arg;
{
    char *p;

    if (root_allow_size <= root_allow_count)
    {
	if (root_allow_size == 0)
	{
	    root_allow_size = 1;
	    root_allow_vector =
		(char **) malloc (root_allow_size * sizeof (char *));
	}
	else
	{
	    root_allow_size *= 2;
	    root_allow_vector =
		(char **) realloc (root_allow_vector,
				   root_allow_size * sizeof (char *));
	}

	if (root_allow_vector == NULL)
	{
	no_memory:
	    /* Strictly speaking, we're not supposed to output anything
	       now.  But we're about to exit(), give it a try.  */
	    printf ("E Fatal server error, aborting.\n\
error ENOMEM Virtual memory exhausted.\n");

	    /* I'm doing this manually rather than via error_exit ()
	       because I'm not sure whether we want to call server_cleanup.
	       Needs more investigation....  */

#ifdef SYSTEM_CLEANUP
	    /* Hook for OS-specific behavior, for example socket
	       subsystems on NT and OS2 or dealing with windows
	       and arguments on Mac.  */
	    SYSTEM_CLEANUP ();
#endif

	    exit (EXIT_FAILURE);
	}
    }
    p = malloc (strlen (arg) + 1);
    if (p == NULL)
	goto no_memory;
    strcpy (p, arg);
    root_allow_vector[root_allow_count++] = p;
}

void
root_allow_free ()
{
    if (root_allow_vector != NULL)
	free (root_allow_vector);
    root_allow_count = 0;
    root_allow_size = 0;
}

int
root_allow_ok (arg)
    char *arg;
{
    unsigned int i;

    if (root_allow_count == 0)
    {
	/* Probably someone upgraded from CVS before 1.9.10 to 1.9.10
	   or later without reading the documentation about
	   --allow-root.  Printing an error here doesn't disclose any
	   particularly useful information to an attacker because a
	   CVS server configured in this way won't let *anyone* in.  */

	/* Note that we are called from a context where we can spit
	   back "error" rather than waiting for the next request which
	   expects responses.  */
	printf ("\
error 0 Server configuration missing --allow-root in inetd.conf\n");
	error_exit ();
    }

    for (i = 0; i < root_allow_count; ++i)
	if (strcmp (root_allow_vector[i], arg) == 0)
	    return 1;
    return 0;
}

/* This global variable holds the global -d option.  It is NULL if -d
   was not used, which means that we must get the CVSroot information
   from the CVSROOT environment variable or from a CVS/Root file.  */

char *CVSroot_cmdline;

/* Parse a CVSROOT variable into its constituent parts -- method,
 * username, hostname, directory.  The prototypical CVSROOT variable
 * looks like:
 *
 * :method:user@host:path
 *
 * Some methods may omit fields; local, for example, doesn't need user
 * and host.
 *
 * Returns zero on success, non-zero on failure. */

char *CVSroot_original = NULL;	/* the CVSroot that was passed in */
int client_active;		/* nonzero if we are doing remote access */
CVSmethod CVSroot_method;	/* one of the enum values defined in cvs.h */
char *CVSroot_username;		/* the username or NULL if method == local */
char *CVSroot_hostname;		/* the hostname or NULL if method == local */
char *CVSroot_directory;	/* the directory name */

int
parse_cvsroot (CVSroot)
    char *CVSroot;
{
    static int cvsroot_parsed = 0;
    char *cvsroot_copy, *p;
    int check_hostname;

    /* Don't go through the trouble twice. */
    if (cvsroot_parsed)
    {
	error (0, 0, "WARNING (parse_cvsroot): someone called me twice!\n");
	return 0;
    }

    CVSroot_original = xstrdup (CVSroot);
    cvsroot_copy = xstrdup (CVSroot);

    if ((*cvsroot_copy == ':'))
    {
	char *method = ++cvsroot_copy;

	/* Access method specified, as in
	 * "cvs -d :pserver:user@host:/path",
	 * "cvs -d :local:e:\path",
	 * "cvs -d :kserver:user@host:/path", or
	 * "cvs -d :fork:/path".
	 * We need to get past that part of CVSroot before parsing the
	 * rest of it.
	 */

	if (! (p = strchr (method, ':')))
	{
	    error (0, 0, "bad CVSroot: %s", CVSroot);
	    return 1;
	}
	*p = '\0';
	cvsroot_copy = ++p;

	/* Now we have an access method -- see if it's valid. */

	if (strcmp (method, "local") == 0)
	    CVSroot_method = local_method;
	else if (strcmp (method, "pserver") == 0)
	    CVSroot_method = pserver_method;
	else if (strcmp (method, "kserver") == 0)
	    CVSroot_method = kserver_method;
	else if (strcmp (method, "gserver") == 0)
	    CVSroot_method = gserver_method;
	else if (strcmp (method, "server") == 0)
	    CVSroot_method = server_method;
	else if (strcmp (method, "ext") == 0)
	    CVSroot_method = ext_method;
	else if (strcmp (method, "fork") == 0)
	    CVSroot_method = fork_method;
	else
	{
	    error (0, 0, "unknown method in CVSroot: %s", CVSroot);
	    return 1;
	}
    }
    else
    {
	/* If the method isn't specified, assume
	   SERVER_METHOD/EXT_METHOD if the string contains a colon or
	   LOCAL_METHOD otherwise.  */

	CVSroot_method = ((strchr (cvsroot_copy, ':'))
#ifdef RSH_NOT_TRANSPARENT
			  ? server_method
#else
			  ? ext_method
#endif
			  : local_method);
    }

    client_active = (CVSroot_method != local_method);

    /* Check for username/hostname if we're not LOCAL_METHOD. */

    CVSroot_username = NULL;
    CVSroot_hostname = NULL;

    if ((CVSroot_method != local_method)
	&& (CVSroot_method != fork_method))
    {
	/* Check to see if there is a username in the string. */

	if ((p = strchr (cvsroot_copy, '@')))
	{
	    CVSroot_username = cvsroot_copy;
	    *p = '\0';
	    cvsroot_copy = ++p;
	    if (*CVSroot_username == '\0')
		CVSroot_username = NULL;
	}

	if ((p = strchr (cvsroot_copy, ':')))
	{
	    CVSroot_hostname = cvsroot_copy;
	    *p = '\0';
	    cvsroot_copy = ++p;
      
	    if (*CVSroot_hostname == '\0')
		CVSroot_hostname = NULL;
	}
    }

    CVSroot_directory = cvsroot_copy;

#if ! defined (CLIENT_SUPPORT) && ! defined (DEBUG)
    if (CVSroot_method != local_method)
    {
	error (0, 0, "Your CVSROOT is set for a remote access method");
	error (0, 0, "but your CVS executable doesn't support it");
	error (0, 0, "(%s)", CVSroot);
	return 1;
    }
#endif
  
    /* Do various sanity checks. */

    if (CVSroot_username && ! CVSroot_hostname)
    {
	error (0, 0, "missing hostname in CVSROOT: %s", CVSroot);
	return 1;
    }

    check_hostname = 0;
    switch (CVSroot_method)
    {
    case local_method:
    case fork_method:
	if (CVSroot_username || CVSroot_hostname)
	{
	    error (0, 0, "can't specify hostname and username in CVSROOT");
	    error (0, 0, "when using %s access method",
		   CVSroot_method == local_method ? "local" : "fork");
	    error (0, 0, "(%s)", CVSroot);
	    return 1;
	}
	/* cvs.texinfo has always told people that CVSROOT must be an
	   absolute pathname.  Furthermore, attempts to use a relative
	   pathname produced various errors (I couldn't get it to work),
	   so there would seem to be little risk in making this a fatal
	   error.  */
	if (!isabsolute (CVSroot_directory))
	    error (1, 0, "CVSROOT %s must be an absolute pathname",
		   CVSroot_directory);
	break;
    case kserver_method:
#ifndef HAVE_KERBEROS
	error (0, 0, "Your CVSROOT is set for a kerberos access method");
	error (0, 0, "but your CVS executable doesn't support it");
	error (0, 0, "(%s)", CVSroot);
	return 1;
#else
	check_hostname = 1;
	break;
#endif
    case gserver_method:
#ifndef HAVE_GSSAPI
	error (0, 0, "Your CVSROOT is set for a GSSAPI access method");
	error (0, 0, "but your CVS executable doesn't support it");
	error (0, 0, "(%s)", CVSroot);
	return 1;
#else
	check_hostname = 1;
	break;
#endif
    case server_method:
    case ext_method:
    case pserver_method:
	check_hostname = 1;
	break;
    }

    if (check_hostname)
    {
	if (! CVSroot_hostname)
	{
	    error (0, 0, "didn't specify hostname in CVSROOT: %s", CVSroot);
	    return 1;
	}
    }

    if (*CVSroot_directory == '\0')
    {
	error (0, 0, "missing directory in CVSROOT: %s", CVSroot);
	return 1;
    }
    
    /* Hooray!  We finally parsed it! */
    return 0;
}


/* Set up the global CVSroot* variables as if we're using the local
   repository DIR.  DIR must point to storage which will last for the
   rest of the CVS invocation (for example, the caller might malloc it
   and never free it, or free it just before exiting CVS).  */

void
set_local_cvsroot (dir)
    char *dir;
{
    CVSroot_original = dir;
    CVSroot_method = local_method;
    CVSroot_directory = CVSroot_original;
    CVSroot_username = NULL;
    CVSroot_hostname = NULL;
    client_active = 0;
}


#ifdef DEBUG
/* This is for testing the parsing function.  Use

     gcc -I. -I.. -I../lib -DDEBUG root.c -o root

   to compile.  */

#include <stdio.h>

char *CVSroot;
char *program_name = "testing";
char *command_name = "parse_cvsroot";		/* XXX is this used??? */

/* Toy versions of various functions when debugging under unix.  Yes,
   these make various bad assumptions, but they're pretty easy to
   debug when something goes wrong.  */

void
error_exit PROTO ((void))
{
    exit (1);
}

char *
xstrdup (str)
     const char *str;
{
    return strdup (str);
}

int
isabsolute (dir)
    const char *dir;
{
    return (dir && (*dir == '/'));
}

void
main (argc, argv)
    int argc;
    char *argv[];
{
    program_name = argv[0];

    if (argc != 2)
    {
	fprintf (stderr, "Usage: %s <CVSROOT>\n", program_name);
	exit (2);
    }
  
    if (parse_cvsroot (argv[1]))
    {
	fprintf (stderr, "%s: Parsing failed.\n", program_name);
	exit (1);
    }
    printf ("CVSroot: %s\n", argv[1]);
    printf ("CVSroot_method: %s\n", method_names[CVSroot_method]);
    printf ("CVSroot_username: %s\n",
	    CVSroot_username ? CVSroot_username : "NULL");
    printf ("CVSroot_hostname: %s\n",
	    CVSroot_hostname ? CVSroot_hostname : "NULL");
    printf ("CVSroot_directory: %s\n", CVSroot_directory);

   exit (0);
   /* NOTREACHED */
}
#endif