Use macros for the magic numbers in decompress_iob().

[privoxy.git] / parsers.c

diff --git a/parsers.c b/parsers.c
index dbaa809..fafd0e8 100644 (file)
--- a/parsers.c
+++ b/parsers.c
@@ -1,4 +1,4 @@
-const char parsers_rcs[] = "$Id: parsers.c,v 1.170 2009/06/01 15:14:40 fabiankeil Exp $";
+const char parsers_rcs[] = "$Id: parsers.c,v 1.172 2009/06/01 16:34:48 fabiankeil Exp $";
 /*********************************************************************
  *
  * File        :  $Source: /cvsroot/ijbswa/current/parsers.c,v $
@@ -67,6 +67,15 @@ const char parsers_rcs[] = "$Id: parsers.c,v 1.170 2009/06/01 15:14:40 fabiankei
 
 #ifdef FEATURE_ZLIB
 #include <zlib.h>
+
+#define GZIP_IDENTIFIER_1       0x1f
+#define GZIP_IDENTIFIER_2       0x8b
+
+#define GZIP_FLAG_CHECKSUM      0x02
+#define GZIP_FLAG_EXTRA_FIELDS  0x04
+#define GZIP_FLAG_FILE_NAME     0x08
+#define GZIP_FLAG_COMMENT       0x10
+#define GZIP_FLAG_RESERVED_BITS 0xe0
 #endif
 
 #if !defined(_WIN32) && !defined(__OS2__)
@@ -423,8 +432,8 @@ jb_err decompress_iob(struct client_state *csp)
        * Strip off the gzip header. Please see RFC 1952 for more
        * explanation of the appropriate fields.
        */
-      if ((*cur++ != (char)0x1f)
-       || (*cur++ != (char)0x8b)
+      if (((*cur++ & 0xff) != GZIP_IDENTIFIER_1)
+       || ((*cur++ & 0xff) != GZIP_IDENTIFIER_2)
        || (*cur++ != Z_DEFLATED))
       {
          log_error(LOG_LEVEL_ERROR, "Invalid gzip header when decompressing");
@@ -433,11 +442,7 @@ jb_err decompress_iob(struct client_state *csp)
       else
       {
          int flags = *cur++;
-         /*
-          * XXX: These magic numbers should be replaced
-          * with macros to give a better idea what they do.
-          */
-         if (flags & 0xe0)
+         if (flags & GZIP_FLAG_RESERVED_BITS)
          {
             /* The gzip header has reserved bits set; bail out. */
             log_error(LOG_LEVEL_ERROR, "Invalid gzip header flags when decompressing");
@@ -446,7 +451,7 @@ jb_err decompress_iob(struct client_state *csp)
          cur += 6;
 
          /* Skip extra fields if necessary. */
-         if (flags & 0x04)
+         if (flags & GZIP_FLAG_EXTRA_FIELDS)
          {
             /*
              * Skip a given number of bytes, specified
@@ -476,7 +481,7 @@ jb_err decompress_iob(struct client_state *csp)
          }
 
          /* Skip the filename if necessary. */
-         if (flags & 0x08)
+         if (flags & GZIP_FLAG_FILE_NAME)
          {
             /* A null-terminated string is supposed to follow. */
             while (*cur++ && (cur < csp->iob->eod));
@@ -484,14 +489,14 @@ jb_err decompress_iob(struct client_state *csp)
          }
 
          /* Skip the comment if necessary. */
-         if (flags & 0x10)
+         if (flags & GZIP_FLAG_COMMENT)
          {
             /* A null-terminated string is supposed to follow. */
             while (*cur++ && (cur < csp->iob->eod));
          }
 
          /* Skip the CRC if necessary. */
-         if (flags & 0x02)
+         if (flags & GZIP_FLAG_CHECKSUM)
          {
             cur += 2;
          }
@@ -582,14 +587,15 @@ jb_err decompress_iob(struct client_state *csp)
       char *tmpbuf;                /* used for realloc'ing the buffer */
       size_t oldbufsize = bufsize; /* keep track of the old bufsize */
 
-      /*
-       * If zlib wants more data then there's a problem, because
-       * the complete compressed file should have been buffered.
-       */
       if (0 == zstr.avail_in)
       {
-         log_error(LOG_LEVEL_ERROR, "Unexpected end of compressed iob");
-         return JB_ERR_COMPRESS;
+         /*
+          * If zlib wants more data then there's a problem, because
+          * the complete compressed file should have been buffered.
+          */
+         log_error(LOG_LEVEL_ERROR,
+            "Unexpected end of compressed iob. Using what we got so far.");
+         break;
       }
 
       /*
@@ -659,11 +665,15 @@ jb_err decompress_iob(struct client_state *csp)
        */
    }
 
-   if (status != Z_STREAM_END)
+   if ((status != Z_STREAM_END) && (0 != zstr.avail_in))
    {
-      /* We failed to decompress the stream. */
+      /*
+       * We failed to decompress the stream and it's
+       * not simply because of missing data.
+       */
       log_error(LOG_LEVEL_ERROR,
-         "Error in decompressing to the buffer (iob): %s", zstr.msg);
+         "Unexpected error while decompressing to the buffer (iob): %s",
+         zstr.msg);
       return JB_ERR_COMPRESS;
    }