source: trunk/athena/bin/attach/nfs.c @ 8843

/*
 *      $Source: /afs/dev.mit.edu/source/repository/athena/bin/attach/nfs.c,v $
 *      $Author: ghudson $
 *
 *      Copyright (c) 1988 by the Massachusetts Institute of Technology.
 */

static char *rcsid_nfs_c = "$Header: /afs/dev.mit.edu/source/repository/athena/bin/attach/nfs.c,v 1.8 1996-09-19 22:13:15 ghudson Exp $";

#include "attach.h"
#ifdef NFS

/* If the timeout is not explicitly specified by the attach command,
 * it is set to 20 tenths of a second (i.e. 2 seconds).  This should
 * really be set in the kernel, but due to release shakedown timing,
 * it's kludged in here.
 * Similarly with retransmissions.
 * 
 * The kernel will double the timeout on each retry until it reaches a
 * max of 60 seconds, at which point it uses 60 seconds for the timeout.
 *
 * current kernel defaults: 4 retrans, 7 tenths sec timeout.
 * -JTK, 24 Oct 88
 *
 * The new values are: 6 retrans, 8 tenths sec timeout.
 * The total timeout period is approximately 100 seconds, thus
 * compensating for a gateway rebooting (~40 seconds).
 * -RPB, 9 Feb 88
 * 
 * Calculations:
 *    total time = timeout * (2^(retrans) - 1)
 *    [derived from sum of geometric series = a(r^n-1)/(r-1)]
 *       a = initial timeout
 *       r = 2
 *       n = retrans
 *
 *    This holds true while timeout * 2^retrans <= 60 seconds
 */

#define TIMEO_DEFAULT   8
#define RETRANS_DEFAULT 7

nfs_attach(at, mopt, errorout)
        struct _attachtab *at;
        struct mntopts  *mopt;
        int errorout;
{
        char fsname[BUFSIZ];
        static char myhostname[BUFSIZ] = "";

        /*
         * Handle the 'n' mode.
         */
        if (at->mode == 'n') {
                add_options(mopt, "ro");
        }
        
        /*
         * Try to figure out information about myself.  Use fsname
         * as a temporary buffer.
         */
        if (!myhostname[0]) {
                if (gethostname(myhostname, sizeof(myhostname))) {
                        if (debug_flag)
                                perror("gethostname");
                }
        }

        if (myhostname[0]) {
                if (host_compare(myhostname, at->host)) {
                        if (!override) {
                                fprintf(stderr,
                                        "%s: (filesystem %s) NFS self mount not allowed.\n",
                                        progname, at->hesiodname);
                                error_status = ERR_ATTACHNOTALLOWED;
                                return(FAILURE);
                        }
                        fprintf(stderr, "%s: (filesystem %s) warning: NFS self mount\n",
                                progname, at->hesiodname);
                }
        }

        if ((at->mode != 'n') && do_nfsid)
                if (nfsid(at->host, at->hostaddr[0], MOUNTPROC_KUIDMAP,
                          errorout, at->hesiodname, 1, owner_uid) == FAILURE) {
                        if (mopt->flags & M_RDONLY) {
                                printf("%s: Warning, mapping failed for filesystem %s,\n\tcontinuing with read-only mount.\n",
                                       progname, at->hesiodname);
                                /* So the mount rpc wins */
                                clear_errored(at->hostaddr[0]); 
                        } else if(at->mode == 'm') {
                                printf("%s: Warning, mapping failed for filesystem %s.\n", 
                                       progname, at->hesiodname);
                                error_status = 0;
                                clear_errored(at->hostaddr[0]);
                        } else
                                return (FAILURE);
                }

        if (!(mopt->tsa.nfs.flags & NFSMNT_RETRANS)) {
                mopt->tsa.nfs.flags |= NFSMNT_RETRANS;
                mopt->tsa.nfs.retrans = RETRANS_DEFAULT;
        }
            
        if (!(mopt->tsa.nfs.flags & NFSMNT_TIMEO)) {
                mopt->tsa.nfs.flags |= NFSMNT_TIMEO;
                mopt->tsa.nfs.timeo = TIMEO_DEFAULT;
        }
    
        /* XXX This is kind of bogus, because if a filesystem has a number
         * of hesiod entries, and the mount point is busy, each one will
         * be tried until the last one fails, then an error printed.
         * C'est la vie.
         */
        
        sprintf(fsname, "%s:%s", at->host, at->hostdir);

        if (mountfs(at, fsname, mopt, errorout) == FAILURE) {
                if ((at->mode != 'n') && do_nfsid)
                        nfsid(at->host, at->hostaddr[0], MOUNTPROC_KUIDUMAP,
                              errorout, at->hesiodname, 1, owner_uid);
                return (FAILURE);
        }

        return (SUCCESS);
}

/*
 * Detach an NFS filesystem.
 */
nfs_detach(at)
    struct _attachtab *at;
{
        if ((at->mode != 'n') && do_nfsid &&
            nfsid(at->host, at->hostaddr[0], MOUNTPROC_KUIDUMAP, 1,
                  at->hesiodname,0, owner_uid) == FAILURE)
                printf("%s: Warning: couldn't unmap filesystem %s/host %s\n",
                       progname, at->hesiodname, at->host);

        if (at->flags & FLAG_PERMANENT) {
                if (debug_flag)
                        printf("Permanent flag on, skipping umount.\n");
                return(SUCCESS);
        }
        
        if (nfs_unmount(at->hesiodname, at->host, at->hostaddr[0],
                        at->mntpt, at->hostdir) == FAILURE)
                return (FAILURE);
    
        return (SUCCESS);
}

/*
 * Parsing of explicit NFS file types
 */
char **nfs_explicit(name)
    char *name;
{
    char temp[BUFSIZ], host[BUFSIZ];
    char *dir, *cp;
    char newmntpt[BUFSIZ];
    extern char *exp_hesptr[2];

    filsys_type = "NFS";
    strcpy(host, name);
    dir = strchr(host, ':');
    if (!dir) {
        fprintf(stderr, "%s: Illegal explicit definition \"%s\" for type %s\n",
                progname, name, filsys_type); 
        return (0);
    }
    *dir = '\0';
    dir++;
    if (*dir != '/') {
        fprintf(stderr, "%s: Illegal explicit definition \"%s\" for type %s\n",
                progname, name, filsys_type);
        return (0);
    }

    if (!nfs_mount_dir)
            nfs_mount_dir = strdup("");
    if (!mntpt) {
            strcpy(temp, host);
            /*
             * Zero out any domain names, since they're ugly as mount
             * points.
             */
            if (cp = strchr(temp, '.'))
                    *cp = '\0';
            if (!strcmp(dir, "/")) {
                    if (nfs_root_hack)
                            sprintf(newmntpt, "%s/%s/root",
                                    nfs_mount_dir, temp);
                    else
                            sprintf(newmntpt, "%s/%s", nfs_mount_dir, temp);
            } else
                    sprintf(newmntpt, "%s/%s%s", nfs_mount_dir, temp, dir);
    }
    
    sprintf(exp_hesline, "NFS %s %s %c %s", dir, host, override_mode ?
            override_mode : 'w',mntpt ? mntpt : newmntpt);
    exp_hesptr[0] = exp_hesline;
    exp_hesptr[1] = 0;
    return (exp_hesptr);
}
#endif