Errors returned from read(2) system call were ignored in most input plugins

(e.g. when accessing an encrypted dvd without proper dvd drive authentication).
Print error messages, and try to handle read errors.

CVS patchset: 741
CVS date: 2001/10/05 17:36:28

1 files changed, 25 insertions, 7 deletions

diff --git a/src/input/read_cache.c b/src/input/read_cache.c
index 2fd18310b..2eee53d2b 100644
--- a/src/input/read_cache.c
+++ b/src/input/read_cache.c
@@ -17,12 +17,14 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA
  *
- * $Id: read_cache.c,v 1.4 2001/10/03 15:09:47 jkeil Exp $
+ * $Id: read_cache.c,v 1.5 2001/10/05 17:36:28 jkeil Exp $
  */
 
 #include <sys/types.h>
-#include <stdlib.h>
 #include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
 
 #include "utils.h"
 
@@ -41,6 +43,7 @@ struct macro_buf_s {
   off_t         adr;
 
   uint8_t      *data;
+  int		size_valid;	/* amount of valid data bytes in 'data' */
   read_cache_t *source;
 };
 
@@ -177,6 +180,7 @@ buf_element_t *read_cache_read_block (read_cache_t *this,
   buf_element_t *buf;
   off_t          madr;
   int            badr;
+  int		 bytes_read;
 
   pthread_setcancelstate(PTHREAD_CANCEL_ENABLE,NULL);
 
@@ -191,7 +195,8 @@ buf_element_t *read_cache_read_block (read_cache_t *this,
 
   /* find or create macroblock that contains this block */
 
-  if ( !this->cur_mbuf || (this->cur_mbuf->adr != madr) ) {
+  if ( !this->cur_mbuf || (this->cur_mbuf->adr != madr) ||
+       (this->cur_mbuf->size_valid <= badr) ) {
 
     if (this->cur_mbuf && (!this->cur_mbuf->ref)) {
 
@@ -210,11 +215,21 @@ buf_element_t *read_cache_read_block (read_cache_t *this,
 
     mbuf->adr = madr;
     mbuf->ref = 0;
+    mbuf->size_valid = 0;
 
-    /* FIXME: error checking */
-    lseek (this->fd, madr, SEEK_SET) ;
-    pthread_testcancel();
-    read ( this->fd, mbuf->data, 2048*16);
+    if (lseek (this->fd, madr, SEEK_SET) < 0) {
+      fprintf(stderr, "read_cache: can't seek to offset %lld (%s)\n",
+	      (long long)madr, strerror (errno));
+    } else {
+      pthread_testcancel();
+      if ((bytes_read = read (this->fd, mbuf->data, 2048*16)) != 2048*16) {
+	  if (bytes_read < 0) /* reading encrypted dvd without authentication? */
+	  fprintf(stderr, "read_cache: read error (%s)\n", strerror (errno));
+	else
+	  fprintf(stderr, "read_cache: short read (%d != %d)\n", bytes_read, 2048*16);
+      }
+      mbuf->size_valid = bytes_read;
+    }
 
     this->cur_mbuf = mbuf;
 
@@ -222,6 +237,9 @@ buf_element_t *read_cache_read_block (read_cache_t *this,
     mbuf = this->cur_mbuf;
   }
 
+  /* check for read errors */
+  if ( badr > mbuf->size_valid )
+    return NULL;
 
   /* create buf */