1 files changed, 158 insertions, 0 deletions
diff --git a/src/common/fmemopen-funopen.c b/src/common/fmemopen-funopen.c
new file mode 100644
index 0000000..87c8675
--- /dev/null
+++ b/src/common/fmemopen-funopen.c
@@ -0,0 +1,158 @@
+/*
+ * POSIX 2008 fmemopen(3) implemented in terms of BSD funopen(3)
+ */
+
+/*
+ * Copyright (c) 2013 Taylor R. Campbell
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#define	_BSD_SOURCE
+#define	_NETBSD_SOURCE
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "fmemopen.h"
+
+struct fmem_cookie {
+  void *fmc_buffer;
+  size_t fmc_index;
+  size_t fmc_limit;
+};
+
+static int
+fmem_read(void *cookie, char *buffer, int n)
+{
+  struct fmem_cookie *const fmc = cookie;
+
+  if (n < 0) {                  /* paranoia */
+    errno = EINVAL;
+    return -1;
+  }
+
+  if (n > (fmc->fmc_limit - fmc->fmc_index))
+    n = (fmc->fmc_limit - fmc->fmc_index);
+
+  (void)memcpy(buffer, (char *)fmc->fmc_buffer + fmc->fmc_index, n);
+  fmc->fmc_index += n;
+  return n;
+}
+
+static int
+fmem_write(void *cookie, const char *buffer, int n)
+{
+  struct fmem_cookie *const fmc = cookie;
+
+  if (n < 0) {                  /* paranoia */
+    errno = EINVAL;
+    return -1;
+  }
+
+  if (n > (fmc->fmc_limit - fmc->fmc_index))
+    n = (fmc->fmc_limit - fmc->fmc_index);
+
+  (void)memcpy((char *)fmc->fmc_buffer + fmc->fmc_index, buffer, n);
+  fmc->fmc_index += n;
+  return n;
+}
+
+static fpos_t
+fmem_seek(void *cookie, fpos_t offset, int cmd)
+{
+  struct fmem_cookie *const fmc = cookie;
+
+  switch (cmd) {
+  case SEEK_SET:
+    if ((offset < 0) || (fmc->fmc_limit < offset))
+      goto einval;
+    fmc->fmc_index = offset;
+    return 0;
+
+  case SEEK_CUR:
+    if (offset < 0) {
+      /* Assume two's-complement arithmetic.  */
+      if ((offset == ~(fpos_t)0) || (-offset > fmc->fmc_index))
+        goto einval;
+    } else {
+      if (offset > (fmc->fmc_limit - fmc->fmc_index))
+        goto einval;
+    }
+    fmc->fmc_index += offset;
+    return 0;
+
+  case SEEK_END:
+      /* Assume two's-complement arithmetic.  */
+    if ((offset >= 0) || (offset == ~(fpos_t)0) || (fmc->fmc_limit < -offset))
+      goto einval;
+    fmc->fmc_index = (fmc->fmc_limit + offset);
+    return 0;
+
+  default:
+    goto einval;
+  }
+
+einval:
+  errno = EINVAL;
+  return -1;
+}
+
+static int
+fmem_close(void *cookie)
+{
+  struct fmem_cookie *const fmc = cookie;
+
+  free(fmc);
+
+  return 0;
+}
+
+FILE *
+fmemopen(void *buffer, size_t len, const char *mode)
+{
+  struct fmem_cookie *fmc;
+  FILE *file;
+
+  fmc = malloc(sizeof(*fmc));
+  if (fmc == NULL)
+    goto fail0;
+
+  (void)memset(fmc, 0, sizeof(*fmc));
+  fmc->fmc_buffer = buffer;
+  fmc->fmc_index = 0;
+  fmc->fmc_limit = len;
+
+  file = funopen(fmc, &fmem_read, &fmem_write, &fmem_seek, &fmem_close);
+  if (file == NULL)
+    goto fail1;
+
+  return file;
+
+fail1:
+  free(fmc);
+fail0:
+  return NULL;
+}