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 #if !defined(GFP_NOFS)
  38 #define GFP_NOFS GFP_KERNEL
  39 #endif
  40     tmp = kmalloc(sizeof(cred_t), GFP_NOFS);
  41     memset(tmp, 0, sizeof(cred_t));
  42     if (!tmp)
  43         osi_Panic("crget: No more memory for creds!\n");
  44
  45 #if defined(STRUCT_TASK_HAS_CRED)
  46     get_cred(tmp);
  47 #else
  48     tmp->cr_ref = 1;
  49 #endif
  50     return tmp;
  51 }
  52
  53 void
  54 crfree(cred_t * cr)
  55 {
  56 #if defined(STRUCT_TASK_HAS_CRED)
  57     put_cred(cr);
  58 #else
  59     if (cr->cr_ref > 1) {
  60         cr->cr_ref--;
  61         return;
  62     }
  63     put_group_info(afs_cr_group_info(cr));
  64     kfree(cr);
  65 #endif
  66 }
  67
  68
  69 /* Return a duplicate of the cred. */
  70 cred_t *
  71 crdup(cred_t * cr)
  72 {
  73     cred_t *tmp = crget();
  74 #if defined(STRUCT_TASK_HAS_CRED)
  75     afs_copy_creds(tmp, cr);
  76 #else
  77     afs_set_cr_uid(tmp, afs_cr_uid(cr));
  78     afs_set_cr_ruid(tmp, afs_cr_ruid(cr));
  79     afs_set_cr_gid(tmp, afs_cr_gid(cr));
  80     afs_set_cr_rgid(tmp, afs_cr_rgid(cr));
  81
  82     get_group_info(afs_cr_group_info(cr));
  83     afs_set_cr_group_info(tmp, afs_cr_group_info(cr));
  84 #endif
  85     return tmp;
  86 }
  87
  88 cred_t *
  89 crref(void)
  90 {
  91 #if defined(STRUCT_TASK_HAS_CRED)
  92     return (cred_t *)get_current_cred();
  93 #else
  94     cred_t *cr = crget();
  95
  96     afs_set_cr_uid(cr, current_fsuid());
  97     afs_set_cr_ruid(cr, current_uid());
  98     afs_set_cr_gid(cr, current_fsgid());
  99     afs_set_cr_rgid(cr, current_gid());
 100
 101     task_lock(current);
 102     get_group_info(current_group_info());
 103     afs_set_cr_group_info(cr, current_group_info());
 104     task_unlock(current);
 105
 106     return cr;
 107 #endif
 108 }
 109
 110 /* Set the cred info into the current task */
 111 void
 112 crset(cred_t * cr)
 113 {
 114 #if defined(STRUCT_TASK_HAS_CRED)
 115     struct cred *new_creds;
 116
 117     /* If our current task doesn't have identical real and effective
 118      * credentials, commit_cred won't let us change them, so we just
 119      * bail here.
 120      */
 121     if (current->cred != current->real_cred)
 122         return;
 123     new_creds = prepare_creds();
 124     /* Drop the reference to group_info - we'll overwrite it in afs_copy_creds */
 125     put_group_info(new_creds->group_info);
 126     afs_copy_creds(new_creds, current_cred());
 127
 128     commit_creds(new_creds);
 129 #else
 130     struct group_info *old_info;
 131
 132     current->fsuid = afs_cr_uid(cr);
 133     current->uid = afs_cr_ruid(cr);
 134     current->fsgid = afs_cr_gid(cr);
 135     current->gid = afs_cr_rgid(cr);
 136
 137     get_group_info(afs_cr_group_info(cr));
 138     task_lock(current);
 139     old_info = current->group_info;
 140     current->group_info = afs_cr_group_info(cr);
 141     task_unlock(current);
 142     put_group_info(old_info);
 143 #endif
 144 }