Added more debugging information, and made existing

debugging printing to go to stderr. Added limit counts
to all functions to avoid spurious core-dumps.

diff --git a/src/softmagic.c b/src/softmagic.c
index 4271ba941d224ff291f18ef26ff3cae4b4e78118..8b10d06acd73b43796edb7ac211ff6175bd9b25b 100644 (file)
--- a/src/softmagic.c
+++ b/src/softmagic.c
@@ -34,12 +34,12 @@
 
 #ifndef        lint
 static char *moduleid = 
-       "@(#)$Id: softmagic.c,v 1.17 1993/02/19 14:22:48 ian Exp $";
+       "@(#)$Id: softmagic.c,v 1.18 1993/09/16 21:12:08 christos Exp $";
 #endif /* lint */
 
-static int match       __P((unsigned char *));
-static int mcheck      __P((unsigned char      *, struct magic *));
-static void mprint     __P((struct magic *, unsigned char *));
+static int match       __P((unsigned char *, int));
+static int mcheck      __P((unsigned char *, struct magic *, int));
+static void mprint     __P((struct magic *, unsigned char *, int));
 
 /*
  * softmagic - lookup one file in database 
@@ -52,7 +52,7 @@ softmagic(buf, nbytes)
 unsigned char *buf;
 int nbytes;
 {
-       if (match(buf))
+       if (match(buf, nbytes))
                return 1;
 
        return 0;
@@ -86,8 +86,9 @@ int nbytes;
  *     so that higher-level continuations are processed.
  */
 static int
-match(s)
+match(s, nbytes)
 unsigned char  *s;
+int nbytes;
 {
        int magindex = 0;
        int cont_level = 0;
@@ -95,8 +96,8 @@ unsigned char *s;
 
        while (magindex < nmagic) {
                /* if main entry matches, print it... */
-               if (mcheck(s, &magic[magindex])) {
-                       mprint(&magic[magindex],s);
+               if (mcheck(s, &magic[magindex], nbytes)) {
+                       mprint(&magic[magindex],s, nbytes);
                        /*
                         * If we printed something, we'll need to print
                         * a blank before we print something else.
@@ -120,7 +121,7 @@ unsigned char       *s;
                                                cont_level = 
                                                  magic[magindex].cont_level;
                                        }
-                                       if (mcheck(s, &magic[magindex])) {
+                                       if (mcheck(s, &magic[magindex], nbytes)) {
                                                /*
                                                 * This continuation matched.
                                                 * Print its message, with
@@ -136,7 +137,7 @@ unsigned char       *s;
                                                        (void) putchar(' ');
                                                        need_separator = 0;
                                                }
-                                               mprint(&magic[magindex],s);
+                                               mprint(&magic[magindex],s,nbytes);
                                                if (magic[magindex].desc[0])
                                                        need_separator = 1;
 
@@ -163,13 +164,18 @@ unsigned char     *s;
 }
 
 static void
-mprint(m, s)
+mprint(m, s, nbytes)
 struct magic *m;
 unsigned char *s;
+int nbytes;
 {
        register union VALUETYPE *p = (union VALUETYPE *)(s+m->offset);
        char *pp, *rt;
 
+       if (m->offset + sizeof(union VALUETYPE) > nbytes)
+           return;
+       
+
        switch (m->type) {
        case BYTE:
                (void) printf(m->desc,
@@ -211,22 +217,29 @@ unsigned char *s;
 }
 
 static int
-mcheck(s, m)
+mcheck(s, m, nbytes)
 unsigned char  *s;
 struct magic *m;
+int nbytes;
 {
        register union VALUETYPE *p = (union VALUETYPE *)(s+m->offset);
        register long l = m->value.l;
        register long mask = m->mask;
        register long v;
 
+       if (m->offset + sizeof(union VALUETYPE) > nbytes)
+           return 0;
+
        if (debug) {
-               (void) printf("mcheck: %10.10s ", s);
+               (void) fprintf(stderr, "mcheck @%d: ", m->offset);
+               showstr(stderr, (char *) p, 10);
+               (void) fputc('\n', stderr);
+               (void) fputc('\n', stderr);
                mdump(m);
        }
 
        if ( (m->value.s[0] == 'x') && (m->value.s[1] == '\0') ) {
-               printf("BOINK");
+               fprintf(stderr, "BOINK");
                return 1;
        }
 
@@ -282,24 +295,49 @@ struct magic *m;
 
        switch (m->reln) {
        case 'x':
+               if (debug)
+                       (void) fprintf(stderr, "*any* = 1\n");
                return 1;
        case '!':
+               if (debug)
+                       (void) fprintf(stderr, "%d != %d = %d\n", v, l, v != l);
                return v != l;
        case '=':
+               if (debug)
+                       (void) fprintf(stderr, "%d == %d = %d\n", v, l, v == l);
                return v == l;
        case '>':
+               if (debug)
+                       (void) fprintf(stderr, "%d > %d = %d\n", v, l, v > l);
                return v > l;
        case '<':
+               if (debug)
+                       (void) fprintf(stderr, "%d < %d = %d\n", v, l, v < l);
                return v < l;
        case '&':
+               if (debug)
+                       (void) fprintf(stderr, "((%x & %x) == %x) = %d\n",
+                                      v, l, l, (v & l) == l);
                return (v & l) == l;
        case '^':
+               if (debug)
+                       (void) fprintf(stderr, "((%x & %x) != %x) = %d\n",
+                                      v, l, l, (v & l) != l);
                return (v & l) != l;
        case MASK | '=':
+               if (debug)
+                       (void) fprintf(stderr, "((%x & %x) == %x) = %d\n", 
+                                      v, mask, l, (v & mask) == l);
                return (v & mask) == l;
        case MASK | '>':
+               if (debug)
+                       (void) fprintf(stderr, "((%x & %x) > %x) = %d\n", 
+                                      v, mask, l, (v & mask) > l);
                return (v & mask) > l;
        case MASK | '<':
+               if (debug)
+                       (void) fprintf(stderr, "((%x & %x) < %x) = %d\n", 
+                                      v, mask, l, (v & mask) < l);
                return (v & mask) < l;
        default:
                error("mcheck: can't happen: invalid relation %d.\n", m->reln);