src/afs/LINUX/osi_cred.c

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 /*
  11  * osi_cred.c - Linux cred handling routines.
  12  *
  13  */
  14 #include <afsconfig.h>
  15 #include "afs/param.h"
  16
  17
  18 #include "afs/sysincludes.h"
  19 #include "afsincludes.h"
  20
  21 /* Copy one credential structure to another, being careful about references */
  22 static inline void
  23 afs_copy_creds(cred_t *to_cred, const cred_t *from_cred) {
  24     afs_set_cr_uid(to_cred, afs_cr_uid(from_cred));
  25     afs_set_cr_gid(to_cred, afs_cr_gid(from_cred));
  26     afs_set_cr_ruid(to_cred, afs_cr_ruid(from_cred));
  27     afs_set_cr_rgid(to_cred, afs_cr_rgid(from_cred));
  28     get_group_info(afs_cr_group_info(from_cred));
  29     afs_set_cr_group_info(to_cred, afs_cr_group_info(from_cred));
  30 }
  31
  32 cred_t *
  33 crget(void)
  34 {
  35     cred_t *tmp;
  36
  37     tmp = kmalloc(sizeof(cred_t), GFP_NOFS);
  38     memset(tmp, 0, sizeof(cred_t));
  39     if (!tmp)
  40         osi_Panic("crget: No more memory for creds!\n");
  41
  42 #if defined(STRUCT_TASK_HAS_CRED)
  43     get_cred(tmp);
  44 #else
  45     atomic_set(&tmp->cr_ref, 1);
  46 #endif
  47     return tmp;
  48 }
  49
  50 void
  51 crfree(cred_t * cr)
  52 {
  53 #if defined(STRUCT_TASK_HAS_CRED)
  54     put_cred(cr);
  55 #else
  56     if (atomic_dec_and_test(&cr->cr_ref)) {
  57         put_group_info(afs_cr_group_info(cr));
  58         kfree(cr);
  59     }
  60 #endif
  61 }
  62
  63
  64 /* Return a duplicate of the cred. */
  65 cred_t *
  66 crdup(cred_t * cr)
  67 {
  68     cred_t *tmp = crget();
  69 #if defined(STRUCT_TASK_HAS_CRED)
  70     afs_copy_creds(tmp, cr);
  71 #else
  72     afs_set_cr_uid(tmp, afs_cr_uid(cr));
  73     afs_set_cr_ruid(tmp, afs_cr_ruid(cr));
  74     afs_set_cr_gid(tmp, afs_cr_gid(cr));
  75     afs_set_cr_rgid(tmp, afs_cr_rgid(cr));
  76
  77     get_group_info(afs_cr_group_info(cr));
  78     afs_set_cr_group_info(tmp, afs_cr_group_info(cr));
  79 #endif
  80     return tmp;
  81 }
  82
  83 cred_t *
  84 crref(void)
  85 {
  86 #if defined(STRUCT_TASK_HAS_CRED)
  87     return (cred_t *)get_current_cred();
  88 #else
  89     cred_t *cr = crget();
  90
  91     afs_set_cr_uid(cr, current_fsuid());
  92     afs_set_cr_ruid(cr, current_uid());
  93     afs_set_cr_gid(cr, current_fsgid());
  94     afs_set_cr_rgid(cr, current_gid());
  95
  96     task_lock(current);
  97     get_group_info(current_group_info());
  98     afs_set_cr_group_info(cr, current_group_info());
  99     task_unlock(current);
 100
 101     return cr;
 102 #endif
 103 }
 104
 105 /* Set the cred info into the current task */
 106 void
 107 crset(cred_t * cr)
 108 {
 109 #if defined(STRUCT_TASK_HAS_CRED)
 110     struct cred *new_creds;
 111
 112     /* If our current task doesn't have identical real and effective
 113      * credentials, commit_cred won't let us change them, so we just
 114      * bail here.
 115      */
 116     if (current->cred != current->real_cred)
 117         return;
 118     new_creds = prepare_creds();
 119     /* Drop the reference to group_info - we'll overwrite it in afs_copy_creds */
 120     put_group_info(new_creds->group_info);
 121     afs_copy_creds(new_creds, current_cred());
 122
 123     commit_creds(new_creds);
 124 #else
 125     struct group_info *old_info;
 126
 127     current->fsuid = afs_cr_uid(cr);
 128     current->uid = afs_cr_ruid(cr);
 129     current->fsgid = afs_cr_gid(cr);
 130     current->gid = afs_cr_rgid(cr);
 131
 132     get_group_info(afs_cr_group_info(cr));
 133     task_lock(current);
 134     old_info = current->group_info;
 135     current->group_info = afs_cr_group_info(cr);
 136     task_unlock(current);
 137     put_group_info(old_info);
 138 #endif
 139 }