[src/trunk]: src/sys More veriexec refactoring.

[elad <elad%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a0b41a118aa4
branches:  trunk
changeset: 582015:a0b41a118aa4
user:      elad <elad%NetBSD.org@localhost>
date:      Mon Jun 13 20:17:54 2005 +0000

description:
More veriexec refactoring.

  - Use u_char for the fingerprint status.
  - Add a pointer to the vnode's veriexec hash table entry in the vnode
    struct. This saves a lookup and will also used by planned features.
  - When removing a file from the tables, set the vnode fingerprint status
    to NOENTRY.
  - Add switch to do flag-specific handling in veriexec_verify(). At the
    moment this prevents execution of FILE entries in strict level 2, but
    it will also be used by planned features.
  - Use memset() instead of bzero().
  - Various cosmetic changes.

diffstat:

 sys/kern/kern_verifiedexec.c |  50 +++++++++++++++++++++++++++++--------------
 sys/sys/vnode.h              |   6 ++--
 2 files changed, 36 insertions(+), 20 deletions(-)

diffs (148 lines):

diff -r ae40d278f35e -r a0b41a118aa4 sys/kern/kern_verifiedexec.c
--- a/sys/kern/kern_verifiedexec.c      Mon Jun 13 19:31:54 2005 +0000
+++ b/sys/kern/kern_verifiedexec.c      Mon Jun 13 20:17:54 2005 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_verifiedexec.c,v 1.19 2005/05/29 16:07:10 elad Exp $      */
+/*     $NetBSD: kern_verifiedexec.c,v 1.20 2005/06/13 20:17:54 elad Exp $      */
 
 /*-
  * Copyright 2005 Elad Efrat <elad%bsd.org.il@localhost>
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_verifiedexec.c,v 1.19 2005/05/29 16:07:10 elad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_verifiedexec.c,v 1.20 2005/06/13 20:17:54 elad Exp $");
 
 #include <sys/param.h>
 #include <sys/mount.h>
@@ -215,8 +215,7 @@
                panic("veriexec: Operations vector is NULL");
        }
 
-       bzero(fp, vhe->ops->hash_len);
-
+       memset(fp, 0, vhe->ops->hash_len);
 
        ctx = (void *) malloc(vhe->ops->context_size, M_TEMP, M_WAITOK);
        buf = (u_char *) malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
@@ -243,11 +242,11 @@
                if (error)
                        goto bad;
 
-                 /* calculate fingerprint for each chunk */
+               /* calculate fingerprint for each chunk */
                (vhe->ops->update)(ctx, buf, (unsigned int) len);
        }
 
-         /* finalise the fingerprint calculation */
+       /* finalise the fingerprint calculation */
        (vhe->ops->final)(fp, ctx);
 
 bad:
@@ -354,26 +353,25 @@
 veriexec_verify(struct proc *p, struct vnode *vp, struct vattr *va,
                const u_char *name, int flag)
 {
-       struct veriexec_hash_entry *vhe;
         u_char *digest;
         int error = 0;
 
        /* Evaluate fingerprint if needed and set the status on the vp. */
-       if (vp->fp_status == FINGERPRINT_NOTEVAL) {
-               vhe = veriexec_lookup(va->va_fsid, va->va_fileid);
-               if (vhe == NULL) {
+       if ((vp->vhe == NULL) || (vp->fp_status == FINGERPRINT_NOTEVAL)) {
+               vp->vhe = veriexec_lookup(va->va_fsid, va->va_fileid);
+               if (vp->vhe == NULL) {
                        vp->fp_status = FINGERPRINT_NOENTRY;
                        goto out;
                }
- 
+
                veriexec_dprintf(("veriexec: veriexec_verify: Got entry for "
                                  "%s. (dev=%d, inode=%u)\n", name,
                                  va->va_fsid, va->va_fileid));
 
-               /* Calculate fingerprint for the inode. */
-               digest = (u_char *) malloc(vhe->ops->hash_len, M_TEMP,
+               digest = (u_char *) malloc(vp->vhe->ops->hash_len, M_TEMP,
                                           M_WAITOK);
-               error = veriexec_fp_calc(p, vp, vhe, va->va_size, digest);
+               error = veriexec_fp_calc(p, vp, vp->vhe, va->va_size, 
+digest);
                
                if (error) {
                        veriexec_dprintf(("veriexec: veriexec_verify: "
@@ -382,8 +380,8 @@
                        return (error);
                }
 
-               if (veriexec_fp_cmp(vhe->ops, vhe->fp, digest) == 0) {
-                       if (vhe->type == VERIEXEC_INDIRECT) {
+               if (veriexec_fp_cmp(vp->vhe->ops, vp->vhe->fp, digest) == 0) {
+                       if (vp->vhe->type == VERIEXEC_INDIRECT) {
                                vp->fp_status = FINGERPRINT_INDIRECT;
                        } else {
                                vp->fp_status = FINGERPRINT_VALID;
@@ -394,6 +392,22 @@
                free(digest, M_TEMP);
        }
 
+       switch (flag) {
+       case VERIEXEC_DIRECT:
+       case VERIEXEC_INDIRECT:
+               break;
+       case VERIEXEC_FILE:
+               if (vp->vhe->type != VERIEXEC_FILE) {
+                       veriexec_report("Execution of 'FILE' entry.",
+                                       name, va, p, REPORT_NOVERBOSE,
+                                       REPORT_ALARM, REPORT_NOPANIC);
+
+                       if (veriexec_strict > 1)
+                               return (EPERM);
+               }
+               break;
+       }
+
 out:
         switch (vp->fp_status) {
        case FINGERPRINT_NOTEVAL:
@@ -443,7 +457,7 @@
                    p, REPORT_VERBOSE, REPORT_NOALARM, REPORT_NOPANIC);
 
                /* We don't care about these in learning mode. */
-               if (veriexec_strict < 1) {
+               if (veriexec_strict == 0) {
                        break;
                }
 
@@ -561,6 +575,8 @@
        free(vhe->fp, M_TEMP);
        free(vhe, M_TEMP);
        tbl->hash_count--;
+       vp->fp_status = FINGERPRINT_NOENTRY;
+       vp->vhe = NULL;
 
        return (error);
 }
diff -r ae40d278f35e -r a0b41a118aa4 sys/sys/vnode.h
--- a/sys/sys/vnode.h   Mon Jun 13 19:31:54 2005 +0000
+++ b/sys/sys/vnode.h   Mon Jun 13 20:17:54 2005 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vnode.h,v 1.137 2005/05/30 22:12:35 christos Exp $     */
+/*     $NetBSD: vnode.h,v 1.138 2005/06/13 20:17:54 elad Exp $ */
 
 /*
  * Copyright (c) 1989, 1993
@@ -122,8 +122,8 @@
        void            *v_data;                /* private data for fs */
        struct klist    v_klist;                /* knotes attached to vnode */
 #ifdef VERIFIED_EXEC
-       char fp_status;                         /* fingerprint status
-                                                  (see below) */
+       u_char fp_status;                       /* fingerprint status */
+       struct veriexec_hash_entry *vhe;        /* veriexec table entry */
 #endif
 };
 #define        v_mountedhere   v_un.vu_mountedhere