work around ultrix stdio bug

now use int flag to scc_open_file
add file format version code

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@1666 dc483132-0cff-0310-8789-dd5450dbe970

1 files changed, 50 insertions, 5 deletions

diff --git a/src/lib/krb5/ccache/stdio/scc_maybe.c b/src/lib/krb5/ccache/stdio/scc_maybe.c
index f684f11fe..8fc61c46f 100644
--- a/src/lib/krb5/ccache/stdio/scc_maybe.c
+++ b/src/lib/krb5/ccache/stdio/scc_maybe.c
@@ -23,12 +23,22 @@ krb5_scc_close_file (id)
      if (data->file == (FILE *) NULL) {
 	 abort ();
      }
+#ifdef ultrix
+     errno = 0;
+#endif
      ret = fflush (data->file);
+#ifdef ultrix
+     /* their LIBC refuses to allow an fflush() of a read-only buffer!
+	We patch around it by only calling it an error if errno is set by a
+	(failed) syscall */
+     if (ret == EOF && !errno) ret = 0;
+#endif
      bzero (data->stdio_buffer, sizeof (data->stdio_buffer));
-     if (ret) {
+     if (ret == EOF) {
+	  int errsave = errno;
 	  (void) fclose (data->file);
 	  data->file = 0;
-	  return krb5_scc_interpret (errno);
+	  return krb5_scc_interpret (errsave);
      }
      ret = fclose (data->file);
      data->file = 0;
@@ -38,11 +48,12 @@ krb5_scc_close_file (id)
 krb5_error_code
 krb5_scc_open_file (id, mode)
     krb5_ccache id;
-    const char *mode;
+    int mode;
 {
+     krb5_int16 scc_fvno = htons(KRB5_SCC_FVNO);
      krb5_scc_data *data;
      FILE *f;
-     int ret;
+     char *open_flag;
 
      data = (krb5_scc_data *) id->data;
      if (data->file) {
@@ -50,13 +61,47 @@ krb5_scc_open_file (id, mode)
 	  (void) fclose (data->file);
 	  data->file = 0;
      }
-     f = fopen (data->filename, mode);
+     switch(mode) {
+     case SCC_OPEN_AND_ERASE:
+	 open_flag = "w+";
+	 break;
+     case SCC_OPEN_RDWR:
+	 open_flag = "r+";
+	 break;
+     case SCC_OPEN_RDONLY:
+     default:
+	 open_flag = "r";
+	 break;
+     }
+
+     f = fopen (data->filename, open_flag);
      if (!f)
 	  return krb5_scc_interpret (errno);
      setbuf (f, data->stdio_buffer);
 #if 0 /* alternative, not requiring sizeof stdio_buffer == BUFSIZ */
      setvbuf(f, data->stdio_buffer, _IOFBF, sizeof (data->stdio_buffer));
 #endif
+
+     if (mode == SCC_OPEN_AND_ERASE) {
+	 /* write the version number */
+	 int errsave;
+
+	 if (!fwrite((char *)&scc_fvno, sizeof(scc_fvno), 1, f)) {
+	     errsave = errno;
+	     (void) fclose(f);
+	     return krb5_scc_interpret(errsave);
+	 }
+     } else {
+	 /* verify a valid version number is there */
+	 if (!fread((char *)&scc_fvno, sizeof(scc_fvno), 1, f)) {
+	     (void) fclose(f);
+	     return KRB5_CCACHE_BADVNO;
+	 }
+	 if (scc_fvno != htons(KRB5_SCC_FVNO)) {
+	     (void) fclose(f);
+	     return KRB5_CCACHE_BADVNO;
+	 }
+     }
      data->file = f;
      return 0;
 }