]> git.decadent.org.uk Git - nfs-utils.git/blobdiff - utils/mount/nfsumount.c
umount.nfs: Refactor remount logic in umount.nfs
[nfs-utils.git] / utils / mount / nfsumount.c
index 28f42448105d20efcf18a00ab77e330ccc256851..4311473b5536f892ad65492b601479c77f394831 100644 (file)
  *
  */
 
+#include <unistd.h>
 #include <stdio.h>
 #include <errno.h>
 #include <getopt.h>
 #include <mntent.h>
 #include <sys/mount.h>
 #include <ctype.h>
+#include <pwd.h>
 
 #include "xcommon.h"
 #include "fstab.h"
 #include "nls.h"
-#include "conn.h"
 
 #include "mount_constants.h"
 #include "mount.h"
-#include "nfsumount.h"
+#include "error.h"
+#include "network.h"
 
 #if !defined(MNT_FORCE)
 /* dare not try to include <linux/mount.h> -- lots of errors */
 #endif
 
 extern char *progname;
-extern int nfs_mount_version;
 extern int nomtab;
 extern int verbose;
 int force;
 int lazy;
 int remount;
 
-extern int find_kernel_nfs_mount_version(void);
-extern int probe_mntport(clnt_addr_t *);
-extern int nfs_gethostbyname(const char *, struct sockaddr_in *);
 
-static inline enum clnt_stat
-nfs3_umount(dirpath *argp, CLIENT *clnt)
+static int try_remount(const char *spec, const char *node)
 {
-       static char clnt_res;
-       memset (&clnt_res, 0, sizeof(clnt_res));
-       return clnt_call(clnt, MOUNTPROC_UMNT,
-                        (xdrproc_t) xdr_dirpath, (caddr_t)argp,
-                        (xdrproc_t) xdr_void, (caddr_t) &clnt_res,
-                        TIMEOUT);
-}
-
-static inline enum clnt_stat
-nfs2_umount(dirpath *argp, CLIENT *clnt)
-{
-       static char clnt_res;
-       memset (&clnt_res, 0, sizeof(clnt_res));
-       return clnt_call(clnt, MOUNTPROC_UMNT,
-                        (xdrproc_t) xdr_dirpath, (caddr_t)argp,
-                        (xdrproc_t) xdr_void, (caddr_t) &clnt_res,
-                        TIMEOUT);
-}
-
-int nfs_call_umount(clnt_addr_t *mnt_server, dirpath *argp)
-{
-       CLIENT *clnt;
-       enum clnt_stat res = 0;
-       int msock;
-
-       clnt = mnt_openclnt(mnt_server, &msock);
-       if (!clnt)
-               goto out_bad;
-       switch (mnt_server->pmap.pm_vers) {
-       case 3:
-               res = nfs3_umount(argp, clnt);
-               break;
-       case 2:
-       case 1:
-               res = nfs2_umount(argp, clnt);
-               break;
-       default:
-               break;
+       int res;
+
+       res = mount(spec, node, NULL,
+                   MS_MGC_VAL | MS_REMOUNT | MS_RDONLY, NULL);
+       if (res == 0) {
+               struct mntent remnt;
+               nfs_error(_("%s: %s busy - remounted read-only"),
+                               progname, spec);
+               remnt.mnt_type = remnt.mnt_fsname = NULL;
+               remnt.mnt_dir = xstrdup(node);
+               remnt.mnt_opts = xstrdup("ro");
+               if (!nomtab)
+                       update_mtab(node, &remnt);
+       } else if (errno != EBUSY) {    /* hmm ... */
+               perror(_("remount"));
+               nfs_error(_("%s: could not remount %s read-only"),
+                               progname, spec);
        }
-       mnt_closeclnt(clnt, msock);
-       if (res == RPC_SUCCESS)
-               return 1;
- out_bad:
-       return 0;
+       return res;
 }
 
-u_int get_mntproto(const char *);
-u_int
-get_mntproto(const char *dirname)
+static int del_mtab(const char *spec, const char *node)
 {
-       FILE *mtab;
-       struct mntent mntbuf;
-       char tmpbuf[BUFSIZ];
-       u_int proto = IPPROTO_TCP; /* assume tcp */
-
-        mtab = setmntent ("/proc/mounts", "r");
-        if (mtab == NULL)
-               mtab = setmntent (_PATH_MOUNTED, "r");
-       if (mtab == NULL)
-               return proto;
-
-       while(getmntent_r(mtab, &mntbuf, tmpbuf, sizeof (tmpbuf))) {
-               if (strcmp(mntbuf.mnt_type, "nfs"))
-                       continue;
-               if (strcmp(dirname,  mntbuf.mnt_fsname))
-                       continue;
-               if (hasmntopt(&mntbuf, "udp"))
-                       proto = IPPROTO_UDP;
-               break;
+       int umnt_err, res;
+
+       umnt_err = 0;
+       if (lazy) {
+               res = umount2 (node, MNT_DETACH);
+               if (res < 0)
+                       umnt_err = errno;
+               goto writemtab;
        }
-       endmntent (mtab);
 
-       return proto;
-}
+       if (force) {
+               res = umount2 (node, MNT_FORCE);
+               if (res == -1) {
+                       int errsv = errno;
+                       perror(_("umount2"));
+                       errno = errsv;
+                       if (errno == ENOSYS) {
+                               if (verbose)
+                                       printf(_("no umount2, trying umount...\n"));
+                               res = umount (node);
+                       }
+               }
+       } else
+               res = umount (node);
 
-/* complain about a failed umount */
-static void complain(int err, const char *dev) {
-  switch (err) {
-    case ENXIO:
-      nfs_error (_("umount: %s: invalid block device"), dev); break;
-    case EINVAL:
-      nfs_error (_("umount: %s: not mounted"), dev); break;
-    case EIO:
-      nfs_error (_("umount: %s: can't write superblock"), dev); break;
-    case EBUSY:
-     /* Let us hope fstab has a line "proc /proc ..."
-        and not "none /proc ..."*/
-      nfs_error (_("umount: %s: device is busy"), dev); break;
-    case ENOENT:
-      nfs_error (_("umount: %s: not found"), dev); break;
-    case EPERM:
-      nfs_error (_("umount: %s: must be superuser to umount"), dev); break;
-    case EACCES:
-      nfs_error (_("umount: %s: block devices not permitted on fs"), dev); break;
-    default:
-      nfs_error (_("umount: %s: %s"), dev, strerror (err)); break;
-  }
-}
+       if (res < 0 && remount && errno == EBUSY && spec) {
+               res = try_remount(spec, node);
+               if (!res)
+                       return 0;
+       }
 
-int add_mtab2(const char *spec, const char *node, const char *type,
-               const char *opts, struct mntentchn *mc)
-{
-       int umnt_err, umnt_err2, res;
-
-        umnt_err = umnt_err2 = 0;
-        if (lazy) {
-                res = umount2 (node, MNT_DETACH);
-                if (res < 0)
-                        umnt_err = errno;
-                goto writemtab;
-        }
-
-        if (force) {
-                res = umount2 (node, MNT_FORCE);
-                if (res == -1) {
-                        int errsv = errno;
-                        perror("umount2");
-                        errno = errsv;
-                        if (errno == ENOSYS) {
-                                if (verbose)
-                                        printf(_("no umount2, trying umount...\n"));
-                                res = umount (node);
-                        }
-                }
-        } else
-                res = umount (node);
-
-        if (res < 0) {
-                umnt_err = errno;
-                /* A device might have been mounted on a node that has since
-                   been deleted or renamed, so if node fails, also try spec. */
-                /* Note that this is incorrect in case spec was mounted
-                   several times. */
-                /* if (umnt_err == ENOENT || umnt_err == EINVAL) */
-                if (umnt_err != EBUSY && strcmp(node, spec)) {
-                        if (verbose)
-                                printf (_("could not umount %s - trying %s instead\n"),
-                                        node, spec);
-                        res = umount (spec);
-                        if (res < 0)
-                                umnt_err2 = errno;
-                       /* Do not complain about remote NFS mount points */
-                        if (errno == ENOENT && index(spec, ':'))
-                                umnt_err2 = 0;
-                }
-        }
-
-        if (res < 0 && remount && (umnt_err == EBUSY || umnt_err2 == EBUSY)) {
-                /* Umount failed - let us try a remount */
-                res = mount(spec, node, NULL,
-                            MS_MGC_VAL | MS_REMOUNT | MS_RDONLY, NULL);
-                if (res == 0) {
-                        nfs_mntent_t remnt;
-                        fprintf(stderr,
-                                _("umount: %s busy - remounted read-only\n"),
-                                spec);
-                        remnt.mnt_type = remnt.mnt_fsname = NULL;
-                        remnt.mnt_dir = xstrdup(node);
-                        remnt.mnt_opts = xstrdup("ro");
-                        if (!nomtab)
-                                update_mtab(node, &remnt);
-                        return 0;
-                } else if (errno != EBUSY) {    /* hmm ... */
-                        perror("remount");
-                        fprintf(stderr,
-                                _("umount: could not remount %s read-only\n"),
-                                spec);
-                }
-        }
-
-        if (res >= 0) {
-                /* Umount succeeded */
-                if (verbose)
-                        printf (_("%s umounted\n"), spec);
-        }
+       if (res >= 0) {
+               /* Umount succeeded */
+               if (verbose)
+                       printf(_("%s umounted\n"), spec ? spec : node);
+       }
 
  writemtab:
-        if (!nomtab &&
-            (umnt_err == 0 || umnt_err == EINVAL || umnt_err == ENOENT)) {
-               update_mtab (node, NULL);
-        }
-
-        if (res >= 0)
-                return 0;
-
-        if (umnt_err2)
-                complain(umnt_err2, spec);
-        if (umnt_err && umnt_err != umnt_err2)
-                complain(umnt_err, node);
-        return 1;
+       if (!nomtab &&
+           (umnt_err == 0 || umnt_err == EINVAL || umnt_err == ENOENT)) {
+               update_mtab(node, NULL);
+       }
+
+       if (res >= 0)
+               return 0;
+
+       if (umnt_err)
+               umount_error(umnt_err, node);
+       return EX_FILEIO;
 }
 
 /*
- * Returns 1 if everything went well, else 0.
+ * Pick up certain mount options used during the original mount
+ * from /etc/mtab.  The basics include the server's IP address and
+ * the server pathname of the share to unregister.
+ *
+ * These options might also describe the mount port, mount protocol
+ * version, and transport protocol used to punch through a firewall.
+ * We will need this information to get through the firewall again
+ * to do the umount.
  */
-int _nfsumount(const char *spec, const char *opts)
+static int do_nfs_umount(const char *spec, char *opts)
 {
        char *hostname;
        char *dirname;
        clnt_addr_t mnt_server = { &hostname, };
+       struct mntent mnt = { .mnt_opts = opts };
        struct pmap *pmap = &mnt_server.pmap;
        char *p;
 
-       nfs_mount_version = find_kernel_nfs_mount_version();
-       if (spec == NULL || (p = strchr(spec,':')) == NULL)
-               goto out_bad;
-       hostname = xstrndup(spec, p-spec);
-       dirname = xstrdup(p+1);
+       if (spec == NULL) {
+               nfs_error(_("%s: No NFS export name was provided"),
+                               progname);
+               return EX_USAGE;
+       }
+       
+       p = strchr(spec, ':');
+       if (p == NULL) {
+               nfs_error(_("%s: '%s' is not a legal NFS export name"),
+                               progname, spec);
+               return EX_USAGE;
+       }
+       hostname = xstrndup(spec, p - spec);
+       dirname = xstrdup(p + 1);
 #ifdef NFS_MOUNT_DEBUG
        printf(_("host: %s, directory: %s\n"), hostname, dirname);
 #endif
@@ -290,25 +186,39 @@ int _nfsumount(const char *spec, const char *opts)
        }
 
        pmap->pm_prog = MOUNTPROG;
-       pmap->pm_vers = MOUNTVERS;
-       pmap->pm_prot = get_mntproto(spec);
+       pmap->pm_vers = MOUNTVERS_NFSV3;
        if (opts && (p = strstr(opts, "mountprog=")) && isdigit(*(p+10)))
                pmap->pm_prog = atoi(p+10);
        if (opts && (p = strstr(opts, "mountport=")) && isdigit(*(p+10)))
                pmap->pm_port = atoi(p+10);
-       if (opts && (p = strstr(opts, "nfsvers=")) && isdigit(*(p+8)))
-               pmap->pm_vers = nfsvers_to_mnt(atoi(p+8));
+       if (opts && hasmntopt(&mnt, "v2"))
+               pmap->pm_vers = nfsvers_to_mnt(2);
+       if (opts && hasmntopt(&mnt, "v3"))
+               pmap->pm_vers = nfsvers_to_mnt(3);
+       if (opts && hasmntopt(&mnt, "v4"))
+               pmap->pm_vers = nfsvers_to_mnt(4);
+       if (opts && (p = strstr(opts, "vers=")) && isdigit(*(p+5)))
+               pmap->pm_vers = nfsvers_to_mnt(atoi(p+5));
        if (opts && (p = strstr(opts, "mountvers=")) && isdigit(*(p+10)))
                pmap->pm_vers = atoi(p+10);
+       if (opts && (hasmntopt(&mnt, "udp") || hasmntopt(&mnt, "proto=udp")))
+               pmap->pm_prot = IPPROTO_UDP;
+       if (opts && (hasmntopt(&mnt, "tcp") || hasmntopt(&mnt, "proto=tcp")))
+               pmap->pm_prot = IPPROTO_TCP;
+
+       if (!nfs_gethostbyname(hostname, &mnt_server.saddr)) {
+               nfs_error(_("%s: '%s' does not contain a recognized hostname"),
+                               progname, spec);
+               return EX_USAGE;
+       }
 
-       if (!nfs_gethostbyname(hostname, &mnt_server.saddr))
-               goto out_bad;
-       if (!probe_mntport(&mnt_server))
-               goto out_bad;
-       return nfs_call_umount(&mnt_server, &dirname);
- out_bad:
-       printf("%s: %s: not found or not mounted\n", progname, spec);
-       return 0;
+       if (!nfs_call_umount(&mnt_server, &dirname)) {
+               nfs_error(_("%s: Server failed to unmount '%s'"),
+                               progname, spec);
+               return EX_USAGE;
+       }
+
+       return EX_SUCCESS;
 }
 
 static struct option umount_longopts[] =
@@ -321,15 +231,15 @@ static struct option umount_longopts[] =
   { NULL, 0, 0, 0 }
 };
 
-void umount_usage()
+static void umount_usage(void)
 {
-       printf("usage: %s dir [-fvnrlh]\n", progname);
-       printf("options:\n\t-f\t\tforce unmount\n");
-       printf("\t-v\t\tverbose\n");
-       printf("\t-n\t\tDo not update /etc/mtab\n");
-       printf("\t-r\t\tremount\n");
-       printf("\t-l\t\tlazy unmount\n");
-       printf("\t-h\t\tprint this help\n\n");
+       printf(_("usage: %s dir [-fvnrlh]\n"), progname);
+       printf(_("options:\n\t-f\t\tforce unmount\n"));
+       printf(_("\t-v\tverbose\n"));
+       printf(_("\t-n\tDo not update /etc/mtab\n"));
+       printf(_("\t-r\tremount\n"));
+       printf(_("\t-l\tlazy unmount\n"));
+       printf(_("\t-h\tprint this help\n\n"));
 }
 
 int nfsumount(int argc, char *argv[])
@@ -338,11 +248,17 @@ int nfsumount(int argc, char *argv[])
        char *spec;
        struct mntentchn *mc;
 
+       if (argc < 2) {
+               umount_usage();
+               return EX_USAGE;
+       }
+
        spec = argv[1];
 
        argv += 1;
        argc -= 1;
 
+       argv[0] = argv[-1]; /* So that getopt error messages are correct */
        while ((c = getopt_long (argc, argv, "fvnrlh",
                                umount_longopts, NULL)) != -1) {
 
@@ -365,28 +281,78 @@ int nfsumount(int argc, char *argv[])
                case 'h':
                default:
                        umount_usage();
-                       return 0;
+                       return EX_USAGE;
                }
        }
+       if (optind != argc) {
+               umount_usage();
+               return EX_USAGE;
+       }
+       
+       if (spec == NULL || (*spec != '/' && strchr(spec,':') == NULL)) {
+               nfs_error(_("%s: %s: not found\n"), progname, spec);
+               return EX_USAGE;
+       }
 
-       mc = getmntdirbackward(spec, NULL);
-       if (!mc)
+       if (*spec == '/')
+               mc = getmntdirbackward(spec, NULL);
+       else
                mc = getmntdevbackward(spec, NULL);
        if (!mc && verbose)
                printf(_("Could not find %s in mtab\n"), spec);
 
-       if(mc) {
-               ret = _nfsumount(mc->m.mnt_fsname, mc->m.mnt_opts);
-               if(ret)
-                       ret = add_mtab2(mc->m.mnt_fsname, mc->m.mnt_dir,
-                               mc->m.mnt_type, mc->m.mnt_opts, mc);
+       if (mc && strcmp(mc->m.mnt_type, "nfs") != 0 &&
+           strcmp(mc->m.mnt_type, "nfs4") != 0) {
+               nfs_error(_("%s: %s on %s is not an NFS filesystem"),
+                               progname, mc->m.mnt_fsname, mc->m.mnt_dir);
+               return EX_USAGE;
        }
-       else {
-               ret = _nfsumount(spec, NULL);
-               if(ret)
-                       ret = add_mtab2(spec, spec, spec, spec, NULL);
+
+       if (getuid() != 0) {
+               /* only permitted if "user=" or "users" is in mount options */
+               if (!mc) {
+                       /* umount might call us twice.  The second time there will
+                        * be no entry in mtab and we should just exit quietly
+                        */
+                       return EX_SUCCESS;
+
+               only_root:
+                       nfs_error(_("%s: You are not permitted to unmount %s"),
+                                       progname, spec);
+                       return EX_USAGE;
+               }
+               if (hasmntopt(&mc->m, "users") == NULL) {
+                       char *opt = hasmntopt(&mc->m, "user");
+                       struct passwd *pw;
+                       char *comma;
+                       int len;
+                       if (!opt)
+                               goto only_root;
+                       if (opt[4] != '=')
+                               goto only_root;
+                       comma = strchr(opt, ',');
+                       if (comma)
+                               len = comma - (opt + 5);
+                       else
+                               len = strlen(opt+5);
+                       pw = getpwuid(getuid());
+                       if (pw == NULL || strlen(pw->pw_name) != len
+                           || strncmp(pw->pw_name, opt+5, len) != 0)
+                               goto only_root;
+               }
        }
 
-       return(ret);
+       ret = 0;
+       if (mc) {
+               if (!lazy)
+                       ret = do_nfs_umount(mc->m.mnt_fsname, mc->m.mnt_opts);
+               if (!ret || force)
+                       ret = del_mtab(mc->m.mnt_fsname, mc->m.mnt_dir);
+       } else if (*spec != '/') {
+               if (!lazy)
+                       ret = do_nfs_umount(spec, "tcp,v3");
+       } else
+               ret = del_mtab(NULL, spec);
+
+       return ret;
 }
-