- use entries get reset to the original buffer (from 0)

- use msetoffset to figure out which buffer to use
- ms->offset is always positive again.

diff --git a/src/file.h b/src/file.h
index 59fd87f5f30fb67d060853a6d4047b207225b37f..06c6f10ca60144f6ac4aea4b81fb74c09b71236f 100644 (file)
--- a/src/file.h
+++ b/src/file.h
@@ -27,7 +27,7 @@
  */
 /*
  * file.h - definitions for file(1) program
- * @(#)$File: file.h,v 1.187 2017/11/03 00:18:55 christos Exp $
+ * @(#)$File: file.h,v 1.188 2017/11/03 02:20:12 christos Exp $
  */
 
 #ifndef __file_h__
@@ -402,7 +402,7 @@ struct magic_set {
                char *buf;              /* Accumulation buffer */
                char *pbuf;             /* Printable buffer */
        } o;
-       int32_t offset;
+       uint32_t offset;
        int error;
        int flags;                      /* Control magic tests. */
        int event_flags;                /* Note things that happened. */

diff --git a/src/softmagic.c b/src/softmagic.c
index 7d43316577de9396f0491bd7d6dd3302d9cc010d..e73de63584e0df474515591a70f16cd704898c62 100644 (file)
--- a/src/softmagic.c
+++ b/src/softmagic.c
@@ -32,7 +32,7 @@
 #include "file.h"
 
 #ifndef        lint
-FILE_RCSID("@(#)$File: softmagic.c,v 1.252 2017/11/03 00:18:55 christos Exp $")
+FILE_RCSID("@(#)$File: softmagic.c,v 1.253 2017/11/03 02:20:12 christos Exp $")
 #endif /* lint */
 
 #include "magic.h"
@@ -47,8 +47,11 @@ private int match(struct magic_set *, struct magic *, uint32_t,
     const struct buffer *, size_t, int, int, int, uint16_t *,
     uint16_t *, int *, int *, int *);
 private int mget(struct magic_set *, struct magic *, const struct buffer *,
+    const unsigned char *, size_t, 
     size_t, unsigned int, int, int, int, uint16_t *,
     uint16_t *, int *, int *, int *);
+private int msetoffset(struct magic_set *, struct magic *, struct buffer *,
+    const struct buffer *, size_t, unsigned int);
 private int magiccheck(struct magic_set *, struct magic *);
 private int32_t mprint(struct magic_set *, struct magic *);
 private int moffset(struct magic_set *, struct magic *, const struct buffer *,
@@ -170,6 +173,7 @@ match(struct magic_set *ms, struct magic *magic, uint32_t nmagic,
        unsigned int cont_level = 0;
        int returnvalv = 0, e; /* if a match is found it is set to 1*/
        int firstline = 1; /* a flag to print X\n  X\n- X */
+       struct buffer bb;
        int print = (ms->flags & MAGIC_NODESC) == 0;
 
        if (returnval == NULL)
@@ -197,12 +201,13 @@ flush:
                        continue; /* Skip to next top-level test*/
                }
 
-               ms->offset = m->offset;
+               if (msetoffset(ms, m, &bb, b, offset, cont_level) == -1)
+                       goto flush;
                ms->line = m->lineno;
 
                /* if main entry matches, print it... */
-               switch (mget(ms, m, b, offset, cont_level, mode, text,
-                   flip, indir_count, name_count,
+               switch (mget(ms, m, b, bb.fbuf, bb.flen, offset, cont_level,
+                   mode, text, flip, indir_count, name_count,
                    printed_something, need_separator, returnval)) {
                case -1:
                        return -1;
@@ -255,7 +260,7 @@ flush:
                if (print && mprint(ms, m) == -1)
                        return -1;
 
-               switch (moffset(ms, m, b, &ms->c.li[cont_level].off)) {
+               switch (moffset(ms, m, &bb, &ms->c.li[cont_level].off)) {
                case -1:
                case 0:
                        goto flush;
@@ -281,7 +286,8 @@ flush:
                                 */
                                cont_level = m->cont_level;
                        }
-                       ms->offset = m->offset;
+                       if (msetoffset(ms, m, &bb, b, offset, cont_level) == -1)
+                               goto flush;
                        if (m->flag & OFFADD) {
                                ms->offset +=
                                    ms->c.li[cont_level - 1].off;
@@ -294,9 +300,10 @@ flush:
                                        continue;
                        }
 #endif
-                       switch (mget(ms, m, b, offset, cont_level, mode,
-                           text, flip, indir_count, name_count,
-                           printed_something, need_separator, returnval)) {
+                       switch (mget(ms, m, b, bb.fbuf, bb.flen, offset,
+                           cont_level, mode, text, flip, indir_count,
+                           name_count, printed_something, need_separator,
+                           returnval)) {
                        case -1:
                                return -1;
                        case 0:
@@ -367,7 +374,7 @@ flush:
                                if (print && mprint(ms, m) == -1)
                                        return -1;
 
-                               switch (moffset(ms, m, b,
+                               switch (moffset(ms, m, &bb,
                                    &ms->c.li[cont_level].off)) {
                                case -1:
                                case 0:
@@ -1339,15 +1346,58 @@ do_ops(struct magic *m, intmax_t lhs, intmax_t off)
        return (uint32_t)offset;
 }
 
+private int
+msetoffset(struct magic_set *ms, struct magic *m, struct buffer *bb,
+    const struct buffer *b, size_t o, unsigned int cont_level)
+{
+       if (m->offset < 0) {
+               if (cont_level > 0) {
+                       file_error(ms, 0, "negative offset %d at continuation"
+                           "level %u", m->offset, cont_level);
+                       return -1;
+               }
+               if (buffer_fill(b) == -1)
+                       return -1;
+               if (o != 0) {
+                       // Not yet!
+                       file_magerror(ms, "non zero offset %zu at"
+                           " level %u", o, cont_level);
+                       return -1;
+               }
+               if ((size_t)-m->offset > b->elen)
+                       return -1;
+               buffer_init(bb, -1, b->ebuf, bb->elen);
+               ms->offset = b->elen + m->offset;
+               // XXX: where to keep this info? not dangerous because
+               // bb has always fd == -1
+               bb->elen = ms->offset;
+       } else {
+               if (cont_level == 0) {
+                       // XXX: Pass real fd, then who frees bb?
+                       buffer_init(bb, -1, b->fbuf, b->flen);
+                       ms->offset = m->offset;
+               } else {
+                       if (bb->fbuf == b->ebuf)
+                               ms->offset = bb->elen + m->offset;
+                       else
+                               ms->offset = m->offset;
+               }
+       }
+       if ((ms->flags & MAGIC_DEBUG) != 0) {
+               fprintf(stderr, "bb=[%p,%zu], %d [b=%p,%zu], [o=%#x, c=%d]\n",
+                   bb->fbuf, bb->flen, ms->offset, b->fbuf, b->flen,
+                   m->offset, cont_level);
+       }
+       return 0;
+}
+
 private int
 mget(struct magic_set *ms, struct magic *m, const struct buffer *b,
-    size_t o, unsigned int cont_level, int mode, int text,
-    int flip, uint16_t *indir_count, uint16_t *name_count,
+    const unsigned char *s, size_t nbytes, size_t o, unsigned int cont_level,
+    int mode, int text, int flip, uint16_t *indir_count, uint16_t *name_count,
     int *printed_something, int *need_separator, int *returnval)
 {
-       const unsigned char *s;
-       size_t nbytes;
-       uint32_t offset;
+       uint32_t offset = ms->offset;
        struct buffer bb;
        intmax_t lhs;
        file_pushbuf_t *pb;
@@ -1368,30 +1418,7 @@ mget(struct magic_set *ms, struct magic *m, const struct buffer *b,
                return -1;
        }
 
-       if (ms->offset < 0) {
-               if (cont_level > 0) {
-                       file_error(ms, 0, "negative offset %d at continuation"
-                           "level %u", ms->offset, cont_level);
-                       return -1;
-               }
-               if (buffer_fill(b) == -1)
-                       return -1;
-               if (o != 0) {
-                       // Not yet!
-                       file_magerror(ms, "non zero offset %zu at"
-                           " level %u", o, cont_level);
-                       return -1;
-               }
-               if ((size_t)-ms->offset > b->elen)
-                       return -1;
-               s = b->ebuf;
-               nbytes = b->elen;
-               offset = b->elen + ms->offset;
-       } else {
-               s = b->fbuf;
-               nbytes = b->flen;
-               offset = ms->offset;
-       }
+
 
        if (mcopy(ms, p, m->type, m->flag & INDIR, s, (uint32_t)(offset + o),
            (uint32_t)nbytes, m) == -1)
@@ -1618,11 +1645,6 @@ mget(struct magic_set *ms, struct magic *m, const struct buffer *b,
                return rv;
 
        case FILE_USE:
-               if (ms->offset < 0) {
-                       file_magerror(ms, "negative offset not supported yet"
-                           " for USE magic");
-                       return -1;
-               }
                if (nbytes < offset)
                        return 0;
                rbuf = m->value.s;