[src/trunk]: src/bin/systrace introduce normalize filename function.

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

details:   https://anonhg.NetBSD.org/src/rev/ef148d7b4a0d
branches:  trunk
changeset: 550236:ef148d7b4a0d
user:      provos <provos%NetBSD.org@localhost>
date:      Sat Aug 02 14:29:33 2003 +0000

description:
introduce normalize filename function.

diffstat:

 bin/systrace/intercept.c |  51 ++++++++++++++++++++++++++++++++----------------
 bin/systrace/intercept.h |   3 +-
 2 files changed, 36 insertions(+), 18 deletions(-)

diffs (118 lines):

diff -r 9e0b674b081f -r ef148d7b4a0d bin/systrace/intercept.c
--- a/bin/systrace/intercept.c  Sat Aug 02 14:24:30 2003 +0000
+++ b/bin/systrace/intercept.c  Sat Aug 02 14:29:33 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: intercept.c,v 1.15 2003/08/02 14:24:30 provos Exp $    */
+/*     $NetBSD: intercept.c,v 1.16 2003/08/02 14:29:33 provos Exp $    */
 /*     $OpenBSD: intercept.c,v 1.29 2002/08/28 03:30:27 itojun Exp $   */
 /*
  * Copyright 2002 Niels Provos <provos%citi.umich.edu@localhost>
@@ -30,7 +30,7 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: intercept.c,v 1.15 2003/08/02 14:24:30 provos Exp $");
+__RCSID("$NetBSD: intercept.c,v 1.16 2003/08/02 14:29:33 provos Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -571,17 +571,35 @@
 char *
 intercept_filename(int fd, pid_t pid, void *addr, int userp)
 {
+       char *name;
+
+       if ((name = intercept_get_string(fd, pid, addr)) == NULL)
+               goto abort;
+
+       if ((name = normalize_filename(fd, pid, name, userp)) == NULL)
+               goto abort;
+
+       return (name);
+
+ abort:
+       ic_abort = 1;
+       return (NULL);
+}
+
+/*
+ * Normalizes a pathname so that Systrace policies entries are
+ * invariant to symlinks.
+ */
+
+char *
+normalize_filename(int fd, pid_t pid, char *name, int userp)
+{
        static char cwd[2*MAXPATHLEN];
-       char *name;
        int havecwd = 0;
 
-       name = intercept_get_string(fd, pid, addr);
-       if (name == NULL)
-               goto abort;
-
-       if (intercept.setcwd(fd, pid) == -1) {
+       if (fd != -1 && intercept.setcwd(fd, pid) == -1) {
                if (errno == EBUSY)
-                       goto abort;
+                       return (NULL);
        getcwderr:
                if (strcmp(name, "/") == 0)
                        return (name);
@@ -608,13 +626,16 @@
 
        if (userp != ICLINK_NONE) {
                static char rcwd[2*MAXPATHLEN];
+               char *file = basename(cwd);
                int failed = 0;
 
+               /* The dot may be used by rmdir("/tmp/something/.") */
+               if (strcmp(file, ".") == 0)
+                       goto nolast;
+
                if (userp == ICLINK_NOLAST) {
-                       char *file = basename(cwd);
-
                        /* Check if the last component has special meaning */
-                       if (strcmp(file, ".") == 0 || strcmp(file, "..") == 0)
+                       if (strcmp(file, "..") == 0 || strcmp(file, "/") == 0)
                                userp = ICLINK_ALL;
                        else
                                goto nolast;
@@ -673,7 +694,7 @@
 
 
        /* Restore working directory and change root space after realpath */
-       if (intercept.restcwd(fd) == -1)
+       if (fd != -1 && intercept.restcwd(fd) == -1)
                err(1, "%s: restcwd", __func__);
 
        return (name);
@@ -681,10 +702,6 @@
  error:
        errx(1, "%s: filename too long", __func__);
        /* NOTREACHED */
-
- abort:
-       ic_abort = 1;
-       return (NULL);
 }
 
 void
diff -r 9e0b674b081f -r ef148d7b4a0d bin/systrace/intercept.h
--- a/bin/systrace/intercept.h  Sat Aug 02 14:24:30 2003 +0000
+++ b/bin/systrace/intercept.h  Sat Aug 02 14:29:33 2003 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: intercept.h,v 1.11 2003/08/02 14:24:30 provos Exp $    */
+/*     $NetBSD: intercept.h,v 1.12 2003/08/02 14:29:33 provos Exp $    */
 /*     $OpenBSD: intercept.h,v 1.11 2002/08/04 04:15:50 provos Exp $   */
 /*
  * Copyright 2002 Niels Provos <provos%citi.umich.edu@localhost>
@@ -184,6 +184,7 @@
 int intercept_existpids(void);
 
 char *intercept_get_string(int, pid_t, void *);
+char *normalize_filename(int, pid_t, char *, int);
 char *intercept_filename(int, pid_t, void *, int);
 void intercept_syscall(int, pid_t, u_int16_t, int, const char *, int,
     const char *, void *, int);