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 #if defined(STRUCT_TASK_STRUCT_HAS_CRED)
  25     /* Skip afs_from_kuid/afs_make_kuid round trip */
  26     to_cred->fsuid = from_cred->fsuid;
  27     to_cred->fsgid = from_cred->fsgid;
  28     to_cred->uid = from_cred->uid;
  29     to_cred->gid = from_cred->gid;
  30 #else
  31     afs_set_cr_uid(to_cred, afs_cr_uid(from_cred));
  32     afs_set_cr_gid(to_cred, afs_cr_gid(from_cred));
  33     afs_set_cr_ruid(to_cred, afs_cr_ruid(from_cred));
  34     afs_set_cr_rgid(to_cred, afs_cr_rgid(from_cred));
  35 #endif
  36     get_group_info(afs_cr_group_info(from_cred));
  37     afs_set_cr_group_info(to_cred, afs_cr_group_info(from_cred));
  38 }
  39
  40 cred_t *
  41 crget(void)
  42 {
  43     cred_t *tmp;
  44
  45     tmp = kmalloc(sizeof(cred_t), GFP_NOFS);
  46     if (!tmp)
  47         osi_Panic("crget: No more memory for creds!\n");
  48
  49 #if defined(STRUCT_TASK_STRUCT_HAS_CRED)
  50     get_cred(tmp);
  51 #else
  52     atomic_set(&tmp->cr_ref, 1);
  53 #endif
  54     return tmp;
  55 }
  56
  57 void
  58 crfree(cred_t * cr)
  59 {
  60 #if defined(STRUCT_TASK_STRUCT_HAS_CRED)
  61     put_cred(cr);
  62 #else
  63     if (atomic_dec_and_test(&cr->cr_ref)) {
  64         put_group_info(afs_cr_group_info(cr));
  65         kfree(cr);
  66     }
  67 #endif
  68 }
  69
  70
  71 /* Return a duplicate of the cred. */
  72 cred_t *
  73 crdup(cred_t * cr)
  74 {
  75     cred_t *tmp = crget();
  76 #if defined(STRUCT_TASK_STRUCT_HAS_CRED)
  77     afs_copy_creds(tmp, cr);
  78 #else
  79     afs_set_cr_uid(tmp, afs_cr_uid(cr));
  80     afs_set_cr_ruid(tmp, afs_cr_ruid(cr));
  81     afs_set_cr_gid(tmp, afs_cr_gid(cr));
  82     afs_set_cr_rgid(tmp, afs_cr_rgid(cr));
  83
  84     get_group_info(afs_cr_group_info(cr));
  85     afs_set_cr_group_info(tmp, afs_cr_group_info(cr));
  86 #endif
  87     return tmp;
  88 }
  89
  90 cred_t *
  91 crref(void)
  92 {
  93 #if defined(STRUCT_TASK_STRUCT_HAS_CRED)
  94     return (cred_t *)get_current_cred();
  95 #else
  96     cred_t *cr = crget();
  97
  98     afs_set_cr_uid(cr, current_fsuid());
  99     afs_set_cr_ruid(cr, current_uid());
 100     afs_set_cr_gid(cr, current_fsgid());
 101     afs_set_cr_rgid(cr, current_gid());
 102
 103     task_lock(current);
 104     get_group_info(current_group_info());
 105     afs_set_cr_group_info(cr, current_group_info());
 106     task_unlock(current);
 107
 108     return cr;
 109 #endif
 110 }
 111
 112 /* Set the cred info into the current task */
 113 void
 114 crset(cred_t * cr)
 115 {
 116 #if defined(STRUCT_TASK_STRUCT_HAS_CRED)
 117     struct cred *new_creds;
 118
 119     /* If our current task doesn't have identical real and effective
 120      * credentials, commit_cred won't let us change them, so we just
 121      * bail here.
 122      */
 123     if (current->cred != current->real_cred)
 124         return;
 125     new_creds = prepare_creds();
 126     /* Drop the reference to group_info - we'll overwrite it in afs_copy_creds */
 127     put_group_info(new_creds->group_info);
 128     afs_copy_creds(new_creds, cr);
 129
 130     commit_creds(new_creds);
 131 #else
 132     struct group_info *old_info;
 133
 134     current->fsuid = afs_cr_uid(cr);
 135     current->uid = afs_cr_ruid(cr);
 136     current->fsgid = afs_cr_gid(cr);
 137     current->gid = afs_cr_rgid(cr);
 138
 139     get_group_info(afs_cr_group_info(cr));
 140     task_lock(current);
 141     old_info = current->group_info;
 142     current->group_info = afs_cr_group_info(cr);
 143     task_unlock(current);
 144     put_group_info(old_info);
 145 #endif
 146 }