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     if (!tmp)
  39         osi_Panic("crget: No more memory for creds!\n");
  40
  41 #if defined(STRUCT_TASK_STRUCT_HAS_CRED)
  42     get_cred(tmp);
  43 #else
  44     atomic_set(&tmp->cr_ref, 1);
  45 #endif
  46     return tmp;
  47 }
  48
  49 void
  50 crfree(cred_t * cr)
  51 {
  52 #if defined(STRUCT_TASK_STRUCT_HAS_CRED)
  53     put_cred(cr);
  54 #else
  55     if (atomic_dec_and_test(&cr->cr_ref)) {
  56         put_group_info(afs_cr_group_info(cr));
  57         kfree(cr);
  58     }
  59 #endif
  60 }
  61
  62
  63 /* Return a duplicate of the cred. */
  64 cred_t *
  65 crdup(cred_t * cr)
  66 {
  67     cred_t *tmp = crget();
  68 #if defined(STRUCT_TASK_STRUCT_HAS_CRED)
  69     afs_copy_creds(tmp, cr);
  70 #else
  71     afs_set_cr_uid(tmp, afs_cr_uid(cr));
  72     afs_set_cr_ruid(tmp, afs_cr_ruid(cr));
  73     afs_set_cr_gid(tmp, afs_cr_gid(cr));
  74     afs_set_cr_rgid(tmp, afs_cr_rgid(cr));
  75
  76     get_group_info(afs_cr_group_info(cr));
  77     afs_set_cr_group_info(tmp, afs_cr_group_info(cr));
  78 #endif
  79     return tmp;
  80 }
  81
  82 cred_t *
  83 crref(void)
  84 {
  85 #if defined(STRUCT_TASK_STRUCT_HAS_CRED)
  86     return (cred_t *)get_current_cred();
  87 #else
  88     cred_t *cr = crget();
  89
  90     afs_set_cr_uid(cr, current_fsuid());
  91     afs_set_cr_ruid(cr, current_uid());
  92     afs_set_cr_gid(cr, current_fsgid());
  93     afs_set_cr_rgid(cr, current_gid());
  94
  95     task_lock(current);
  96     get_group_info(current_group_info());
  97     afs_set_cr_group_info(cr, current_group_info());
  98     task_unlock(current);
  99
 100     return cr;
 101 #endif
 102 }
 103
 104 /* Set the cred info into the current task */
 105 void
 106 crset(cred_t * cr)
 107 {
 108 #if defined(STRUCT_TASK_STRUCT_HAS_CRED)
 109     struct cred *new_creds;
 110
 111     /* If our current task doesn't have identical real and effective
 112      * credentials, commit_cred won't let us change them, so we just
 113      * bail here.
 114      */
 115     if (current->cred != current->real_cred)
 116         return;
 117     new_creds = prepare_creds();
 118     /* Drop the reference to group_info - we'll overwrite it in afs_copy_creds */
 119     put_group_info(new_creds->group_info);
 120     afs_copy_creds(new_creds, current_cred());
 121
 122     commit_creds(new_creds);
 123 #else
 124     struct group_info *old_info;
 125
 126     current->fsuid = afs_cr_uid(cr);
 127     current->uid = afs_cr_ruid(cr);
 128     current->fsgid = afs_cr_gid(cr);
 129     current->gid = afs_cr_rgid(cr);
 130
 131     get_group_info(afs_cr_group_info(cr));
 132     task_lock(current);
 133     old_info = current->group_info;
 134     current->group_info = afs_cr_group_info(cr);
 135     task_unlock(current);
 136     put_group_info(old_info);
 137 #endif
 138 }