[Libcdio-devel] [PATCH 2/2] Add processing of Rock Ridge CE records

[Pete Batard]

Use the processed cont_extent to read the relevant continuation block
into a buffer and then use that block, along with cont_offset and
cont_size, to carry out further Rock Ridge data processing. The code is
designed to handle chained CE blocks if required.
Also clean up the CHECK...() macros and fix some whitespace issues.
---
 lib/iso9660/rock.c | 79 ++++++++++++++++++++++++++--------------------
 1 file changed, 45 insertions(+), 34 deletions(-)

diff --git a/lib/iso9660/rock.c b/lib/iso9660/rock.c
index ff420dca..d2c01165 100644
--- a/lib/iso9660/rock.c
+++ b/lib/iso9660/rock.c
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2020 Pete Batard <pete@akeo.ie>
+  Copyright (C) 2020, 2023 Pete Batard <pete@akeo.ie>
   Copyright (C) 2005, 2008, 2010-2011, 2014, 2017, 2022 Rocky Bernstein
   <rocky@gnu.org>
 @@ -94,34 +94,36 @@ realloc_symlink(/*in/out*/ iso9660_stat_t *p_stat, 
uint8_t i_grow)
  /* This is a way of ensuring that we have something in the system
    use fields that is compatible with Rock Ridge */
-#define CHECK_SP(FAIL)                         \
-      if(rr->u.SP.magic[0] != 0xbe) FAIL;   \
-      if(rr->u.SP.magic[1] != 0xef) FAIL;       \
+#define CHECK_SP(FAIL)                         \
+      if (rr->u.SP.magic[0] != 0xbe) FAIL;  \
+      if (rr->u.SP.magic[1] != 0xef) FAIL;  \
       p_stat->rr.s_rock_offset = rr->u.SP.skip;
 /* We define a series of macros because each function must do exactly the
    same thing in certain places.  We use the macros to ensure that 
everything
    is done correctly */
  #define CONTINUE_DECLS \
-  int cont_extent = 0, cont_offset = 0, cont_size = 0;   \
-  void *buffer = NULL
-
-#define CHECK_CE                                \
-  { cont_extent = from_733(*rr->u.CE.extent);        \
-    cont_offset = from_733(*rr->u.CE.offset);        \
-    cont_size = from_733(*rr->u.CE.size);    \
-    (void)cont_extent; (void)cont_offset, (void)cont_size; }
+  uint32_t cont_extent = 0, cont_offset = 0, cont_size = 0;    \
+  uint8_t *buffer = NULL
+
+#define CHECK_CE(FAIL)                         \
+  { cont_extent = from_733(*rr->u.CE.extent);       \
+    cont_offset = from_733(*rr->u.CE.offset);       \
+    if (cont_offset >= ISO_BLOCKSIZE) FAIL; \
+    cont_size = from_733(*rr->u.CE.size);   \
+    if (cont_size >= ISO_BLOCKSIZE) FAIL;   \
+  }
 -#define SETUP_ROCK_RIDGE(DE,CHR,LEN)                          \
+#define SETUP_ROCK_RIDGE(DE,CHR,LEN)                           \
   {                                                            \
     LEN= sizeof(iso9660_dir_t) + DE->filename.len;          \
-    if(LEN & 1) LEN++;                                             \
+    if (LEN & 1) LEN++;                                            \
     CHR = ((unsigned char *) DE) + LEN;                                \
     LEN = *((unsigned char *) DE) - LEN;                       \
     if (0xff != p_stat->rr.s_rock_offset)                   \
       {                                                                \
-       LEN -= p_stat->rr.s_rock_offset;                     \
-       CHR += p_stat->rr.s_rock_offset;                     \
+       LEN -= p_stat->rr.s_rock_offset;                     \
+       CHR += p_stat->rr.s_rock_offset;                     \
        if (LEN<0) LEN=0;                                    \
       }                                                                \
   }
@@ -130,22 +132,22 @@ realloc_symlink(/*in/out*/ iso9660_stat_t *p_stat, 
uint8_t i_grow)
    the specified field of a iso_rock_statbuf_t.
    non-paramater variables are p_stat, rr, and cnt.
 */
-#define add_time(FLAG, TIME_FIELD)                               \
-  if (rr->u.TF.flags & FLAG) {                                    \
-    p_stat->rr.TIME_FIELD.b_used = true;                      \
-    p_stat->rr.TIME_FIELD.b_longdate =                                \
-      (0 != (rr->u.TF.flags & ISO_ROCK_TF_LONG_FORM));            \
-    if (p_stat->rr.TIME_FIELD.b_longdate) {                   \
-      memcpy(&(p_stat->rr.TIME_FIELD.t.ltime),                    \
-            &(rr->u.TF.time_bytes[cnt]),                          \
-            sizeof(iso9660_ltime_t));                            \
-      cnt += sizeof(iso9660_ltime_t);                            \
-    } else {                                                     \
-      memcpy(&(p_stat->rr.TIME_FIELD.t.dtime),                    \
-            &(rr->u.TF.time_bytes[cnt]),                          \
-            sizeof(iso9660_dtime_t));                            \
-      cnt += sizeof(iso9660_dtime_t);                            \
-    }                                                            \
+#define add_time(FLAG, TIME_FIELD)                             \
+  if (rr->u.TF.flags & FLAG) {                                  \
+    p_stat->rr.TIME_FIELD.b_used = true;                    \
+    p_stat->rr.TIME_FIELD.b_longdate =                              \
+      (0 != (rr->u.TF.flags & ISO_ROCK_TF_LONG_FORM));          \
+    if (p_stat->rr.TIME_FIELD.b_longdate) {                 \
+      memcpy(&(p_stat->rr.TIME_FIELD.t.ltime),                  \
+            &(rr->u.TF.time_bytes[cnt]),                        \
+            sizeof(iso9660_ltime_t));                          \
+      cnt += sizeof(iso9660_ltime_t);                          \
+    } else {                                                   \
+      memcpy(&(p_stat->rr.TIME_FIELD.t.dtime),                  \
+            &(rr->u.TF.time_bytes[cnt]),                        \
+            sizeof(iso9660_dtime_t));                          \
+      cnt += sizeof(iso9660_dtime_t);                          \
+    }                                                          \
   }
  /* Indicates if we should process deep directory entries */
@@ -202,7 +204,7 @@ get_rock_ridge_filename(iso9660_dir_t * p_iso9660_dir,
        switch(sig) {
       case SIG('S','P'):
-       CHECK_SP(goto out);
+       CHECK_SP({cdio_warn("Invalid Rock Ridge SP field"); goto out;});
        p_stat->rr.u_su_fields |= ISO_ROCK_SUF_SP;
        break;
       case SIG('C','E'):
@@ -213,8 +215,17 @@ get_rock_ridge_filename(iso9660_dir_t * p_iso9660_dir,
          if ('\1' == p_iso9660_dir->filename.str[1] && 1 == i_fname)
            break;
        }
-       CHECK_CE;
+       CHECK_CE({cdio_warn("Invalid Rock Ridge CE field"); goto out;});
        p_stat->rr.u_su_fields |= ISO_ROCK_SUF_CE;
+       /* We may already be processing a continuation block so free it */
+       free(buffer);
+       buffer = calloc(1, ISO_BLOCKSIZE);
+       if (!buffer)
+         goto out;
+	if (iso9660_iso_seek_read(p_image, buffer, cont_extent, 1) != 
ISO_BLOCKSIZE)
+         goto out;
+       chr = &buffer[cont_offset];
+       len = cont_size;
        break;
       case SIG('E','R'):
        cdio_debug("ISO 9660 Extensions: ");
--
2.39.1.windows.1