Correctly handle "user" and "users" mount options.

[nfs-utils.git] / utils / mount / mount.c

diff --git a/utils/mount/mount.c b/utils/mount/mount.c
index 0edcc1a2565f444263376ced71f127d4e2e07b9c..cdccfe894778a957245242c1657c87629c4659b9 100644 (file)
--- a/utils/mount/mount.c
+++ b/utils/mount/mount.c
@@ -28,6 +28,7 @@
 #include <sys/mount.h>
 #include <getopt.h>
 #include <mntent.h>
+#include <pwd.h>
 
 #include "fstab.h"
 #include "xcommon.h"
@@ -75,6 +76,11 @@ struct opt_map {
   int  mask;                    /* flag mask value */
 };
 
+/* Custom mount options for our own purposes.  */
+#define MS_DUMMY       0x00000000
+#define MS_USERS       0x40000000
+#define MS_USER                0x80000000
+
 static const struct opt_map opt_map[] = {
   { "defaults", 0, 0, 0         },      /* default options */
   { "ro",       1, 0, MS_RDONLY },      /* read-only */
@@ -91,6 +97,20 @@ static const struct opt_map opt_map[] = {
   { "remount",  0, 0, MS_REMOUNT},      /* Alter flags of mounted FS */
   { "bind",     0, 0, MS_BIND   },      /* Remount part of tree elsewhere */
   { "rbind",    0, 0, MS_BIND|MS_REC }, /* Idem, plus mounted subtrees */
+  { "auto",     0, 0, MS_DUMMY },       /* Can be mounted using -a */
+  { "noauto",   0, 0, MS_DUMMY },       /* Can  only be mounted explicitly */
+  { "users",    1, 0, MS_USERS|MS_NOEXEC|MS_NOSUID|MS_NODEV  },
+                                       /* Allow ordinary user to mount */
+  { "nousers",  0, 1, MS_DUMMY  },      /* Forbid ordinary user to mount */
+  { "user",     1, 0, MS_USER|MS_NOEXEC|MS_NOSUID|MS_NODEV  },
+                                       /* Allow ordinary user to mount */
+  { "nouser",   0, 1, MS_DUMMY   },     /* Forbid ordinary user to mount */
+  { "owner",    0, 0, MS_DUMMY  },      /* Let the owner of the device mount */
+  { "noowner",  0, 0, MS_DUMMY  },      /* Device owner has no special privs */
+  { "group",    0, 0, MS_DUMMY  },      /* Let the group of the device mount */
+  { "nogroup",  0, 0, MS_DUMMY  },      /* Device group has no special privs */
+  { "_netdev",  0, 0, MS_DUMMY},        /* Device requires network */
+  { "comment",  0, 0, MS_DUMMY},        /* fstab comment only (kudzu,_netdev)*/
 
   /* add new options here */
 #ifdef MS_NOSUB
@@ -105,6 +125,7 @@ static const struct opt_map opt_map[] = {
   { "mand",     0, 0, MS_MANDLOCK },    /* Allow mandatory locks on this FS */
   { "nomand",   0, 1, MS_MANDLOCK },    /* Forbid mandatory locks on this FS */
 #endif
+  { "loop",     1, 0, MS_DUMMY   },      /* use a loop device */
 #ifdef MS_NOATIME
   { "atime",    0, 1, MS_NOATIME },     /* Update access time */
   { "noatime",  0, 0, MS_NOATIME },     /* Do not update access time */
@@ -122,6 +143,15 @@ static char * fix_opts_string (int flags, const char *extra_opts) {
        char *new_opts;
 
        new_opts = xstrdup((flags & MS_RDONLY) ? "ro" : "rw");
+       if (flags & MS_USER) {
+               /* record who mounted this so they can unmount */
+               struct passwd *pw = getpwuid(getuid());
+               if(pw)
+                       new_opts = xstrconcat3(new_opts, ",user=", pw->pw_name);
+       }
+       if (flags & MS_USERS)
+               new_opts = xstrconcat3(new_opts, ",users", "");
+       
        for (om = opt_map; om->opt != NULL; om++) {
                if (om->skip)
                        continue;
@@ -282,16 +312,12 @@ int main(int argc, char *argv[])
        int c, flags = 0, nfs_mount_vers = 0, mnt_err = 1, fake = 0;
        char *spec, *mount_point, *extra_opts = NULL;
        char *mount_opts = NULL, *p;
+       uid_t uid = getuid();
 
        progname = argv[0];
        if ((p = strrchr(progname, '/')) != NULL)
                progname = p+1;
 
-       if (getuid() != 0) {
-               printf("%s: only root can do that.\n", progname);
-               exit(1);
-       }
-
        if(!strncmp(progname, "umount", strlen("umount"))) {
                if(argc < 2) {
                        umount_usage();
@@ -375,10 +401,35 @@ int main(int argc, char *argv[])
        }
 
        spec = argv[1];
-       mount_point = canonicalize(argv[2]);
+       mount_point = argv[2];
+
+       if (uid != 0) {
+               /* don't even think about it unless options exactly
+                * make fstab
+                */
+               struct mntentchn *mc;
+
+               if ((mc = getfsfile(mount_point)) == NULL ||
+                   strcmp(mc->m.mnt_fsname, spec) != 0 ||
+                   strcmp(mc->m.mnt_opts, mount_opts) != 0) {
+                       fprintf(stderr, "%s: permission died - no match for fstab\n",
+                               progname);
+                       exit(1);
+               }
+               mounttype = 0;
+       }
+
+       mount_point = canonicalize(mount_point);
        
        parse_opts(mount_opts, &flags, &extra_opts);
 
+       if (uid != 0) {
+           if (! (flags & (MS_USERS | MS_USER))) {
+                   fprintf(stderr, "%s: permission denied\n", progname);
+                   exit(1);
+           }
+       }
+
        if (!strcmp(progname, "mount.nfs4") || nfs_mount_vers == 4) {
                nfs_mount_vers = 4;
                mnt_err = nfs4mount(spec, mount_point, &flags, &extra_opts, &mount_opts, 0);