kernel/syscall/ucredsys.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #include <sys/param.h>
  27 #include <sys/types.h>
  28 #include <sys/ucred.h>
  29 #include <sys/file.h>
  30 #include <sys/errno.h>
  31 #include <sys/systm.h>
  32 #include <sys/stream.h>
  33 #include <sys/strsun.h>
  34 #include <sys/stropts.h>
  35 #include <sys/vfs.h>
  36 #include <sys/vnode.h>
  37 #include <sys/cmn_err.h>
  38 #include <sys/socket.h>
  39 #include <sys/strsubr.h>
  40 #include <c2/audit.h>
  41
  42 /*
  43  * Getpeerucred system call implementation.
  44  */
  45 static int
  46 getpeerucred(int fd, void *buf)
  47 {
  48         file_t *fp;
  49         struct ucred_s *uc;
  50         vnode_t *vp;
  51         k_peercred_t kpc;
  52         int err;
  53         int32_t rval;
  54
  55         kpc.pc_cr = NULL;
  56         kpc.pc_cpid = -1;
  57
  58         if ((fp = getf(fd)) == NULL)
  59                 return (set_errno(EBADF));
  60
  61         vp = fp->f_vnode;
  62
  63         switch (vp->v_type) {
  64         case VFIFO:
  65         case VSOCK:
  66                 err = fop_ioctl(vp, _I_GETPEERCRED, (intptr_t)&kpc,
  67                     FKIOCTL, CRED(), &rval, NULL);
  68                 break;
  69         case VCHR: {
  70                 struct strioctl strioc;
  71
  72                 if (vp->v_stream == NULL) {
  73                         err = ENOTSUP;
  74                         break;
  75                 }
  76                 strioc.ic_cmd = _I_GETPEERCRED;
  77                 strioc.ic_timout = INFTIM;
  78                 strioc.ic_len = (int)sizeof (k_peercred_t);
  79                 strioc.ic_dp = (char *)&kpc;
  80
  81                 err = strdoioctl(vp->v_stream, &strioc, FNATIVE|FKIOCTL,
  82                     STR_NOSIG|K_TO_K, CRED(), &rval);
  83
  84                 /*
  85                  * Map all unexpected error codes to ENOTSUP.
  86                  */
  87                 switch (err) {
  88                 case 0:
  89                 case ENOTSUP:
  90                 case ENOTCONN:
  91                 case ENOMEM:
  92                         break;
  93                 default:
  94                         err = ENOTSUP;
  95                         break;
  96                 }
  97                 break;
  98         }
  99         default:
 100                 err = ENOTSUP;
 101                 break;
 102         }
 103         releasef(fd);
 104
 105         /*
 106          * If someone gave us a credential, err will be 0.
 107          */
 108         if (kpc.pc_cr != NULL) {
 109                 ASSERT(err == 0);
 110
 111                 uc = cred2ucred(kpc.pc_cr, kpc.pc_cpid, NULL, CRED());
 112
 113                 crfree(kpc.pc_cr);
 114
 115                 err = copyout(uc, buf, uc->uc_size);
 116
 117                 kmem_free(uc, uc->uc_size);
 118
 119                 if (err != 0)
 120                         return (set_errno(EFAULT));
 121
 122                 return (0);
 123         }
 124         return (set_errno(err));
 125 }
 126
 127 static int
 128 ucred_get(pid_t pid, void *ubuf)
 129 {
 130         proc_t *p;
 131         cred_t *pcr;
 132         int err;
 133         struct ucred_s *uc;
 134         uint32_t auditing = AU_AUDITING();
 135
 136         if (pid == P_MYID || pid == curproc->p_pid) {
 137                 pcr = CRED();
 138                 crhold(pcr);
 139                 pid = curproc->p_pid;
 140         } else {
 141                 cred_t  *updcred = NULL;
 142
 143                 if (pid < 0)
 144                         return (set_errno(EINVAL));
 145
 146                 if (auditing)
 147                         updcred = cralloc();
 148
 149                 mutex_enter(&pidlock);
 150                 p = prfind(pid);
 151
 152                 if (p == NULL) {
 153                         mutex_exit(&pidlock);
 154                         if (updcred != NULL)
 155                                 crfree(updcred);
 156                         return (set_errno(ESRCH));
 157                 }
 158
 159                 /*
 160                  * Assure that audit data in cred is up-to-date.
 161                  * updcred will be used or freed.
 162                  */
 163                 if (auditing)
 164                         audit_update_context(p, updcred);
 165
 166                 err = priv_proc_cred_perm(CRED(), p, &pcr, VREAD);
 167                 mutex_exit(&pidlock);
 168
 169                 if (err != 0)
 170                         return (set_errno(err));
 171         }
 172
 173         uc = cred2ucred(pcr, pid, NULL, CRED());
 174
 175         crfree(pcr);
 176
 177         err = copyout(uc, ubuf, uc->uc_size);
 178
 179         kmem_free(uc, uc->uc_size);
 180
 181         if (err)
 182                 return (set_errno(EFAULT));
 183
 184         return (0);
 185 }
 186
 187 int
 188 ucredsys(int code, int obj, void *buf)
 189 {
 190         switch (code) {
 191         case UCREDSYS_UCREDGET:
 192                 return (ucred_get((pid_t)obj, buf));
 193         case UCREDSYS_GETPEERUCRED:
 194                 return (getpeerucred(obj, buf));
 195         default:
 196                 return (set_errno(EINVAL));
 197         }
 198 }
 199
 200 #ifdef _SYSCALL32_IMPL
 201 int
 202 ucredsys32(int arg1, int arg2, caddr32_t arg3)
 203 {
 204         return (ucredsys(arg1, arg2, (void *)(uintptr_t)arg3));
 205 }
 206 #endif