nacl_io: Add inet_pton() and ip6addr_* consts.

native_client_sdk/src/libraries/nacl_io/syscalls/inet_pton.c

Index: native_client_sdk/src/libraries/nacl_io/syscalls/inet_pton.c
diff --git a/native_client_sdk/src/libraries/nacl_io/syscalls/inet_pton.c b/native_client_sdk/src/libraries/nacl_io/syscalls/inet_pton.c
new file mode 100644
index 0000000000000000000000000000000000000000..b1a2d7a17b4859a5123faa038b4aa40f39b3f795
--- /dev/null
+++ b/native_client_sdk/src/libraries/nacl_io/syscalls/inet_pton.c
@@ -0,0 +1,147 @@
+/* Copyright 2013 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file. */
+
+#include "nacl_io/ossocket.h"
+#if defined(PROVIDES_SOCKET_API) && !defined(__GLIBC__)
+
+#include <ctype.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "sdk_util/macros.h"
+
+enum {
+kIpv4AddressSize = 4,
+kIpv6AddressSize = 16,
+};
+
+/* Helper function for inet_pton() for IPv4 addresses. */
+static int inet_pton_v4(const char* src, void* dst) {
+  const char* pos = src;
+  uint8_t result[kIpv4AddressSize] = {0};
+
+  int i;
+  for (i = 0; i < kIpv4AddressSize; ++i) {
+    /* strtol() won't treat whitespace characters in the beginning as an error,
+     * so check to ensure this is started with digit before passing to strtol().
+     */
+    if (isspace((int)(*pos)))
+      return 0;
+    char* end_pos;
+    unsigned long value = strtoul(pos, &end_pos, 10);
+    if (value > 255 || pos == end_pos)
+      return 0;
+    result[i] = (unsigned char)value;
+    pos = end_pos;
+
+    if (i < (kIpv4AddressSize - 1)) {
+      if (*pos != '.')
+        return 0;
+      ++pos;
+    }
+  }
+  if (*pos != '\0')
+    return 0;
+  memcpy(dst, result, sizeof(result));
+  return 1;
+}
+
+/* Helper function for inet_pton() for IPv6 addresses. */
+int inet_pton_v6(const char* src, void* dst) {
+  /* strtol() skips 0x in from of a number, while it's not allowed in IPv6
+   * addresses. Check that there is no 'x' in the string. */
+  const char* pos = src;
+  while (*pos != '\0') {
+    if (*pos == 'x')
+      return 0;
+    pos++;
+  }
+  pos = src;
+
+  uint8_t result[kIpv6AddressSize];
+  memset(&result, 0, sizeof(result));
+  int double_colon_pos = -1;
+  int result_pos = 0;
+
+  if (*pos == ':') {
+    if (*(pos + 1) != ':')
+      return 0;
+    pos += 2;
+    double_colon_pos = 0;
+  }
+
+  while (*pos != '\0') {
+    /* strtol() won't treat whitespace characters in the beginning as an error,
+     * so check to ensure this is started with digit before passing to strtol().
+     */
+    if (isspace((int)(*pos)))
+      return 0;
+    char* end_pos;
+    unsigned long word = strtoul(pos, &end_pos, 16);
+    if (word > 0xffff || pos == end_pos)
+      return 0;
+
+    if (*end_pos == '.')  {
+      if (result_pos + kIpv4AddressSize > kIpv6AddressSize)
+        return 0;
+      /* Parse rest of address as IPv4 address. */
+      if (!inet_pton_v4(pos, result + result_pos))
+        return 0;
+      result_pos += 4;
+      break;
+    }
+
+    if (result_pos > kIpv6AddressSize - 2)
+      return 0;
+    result[result_pos] = (word & 0xFF00) >> 8;
+    result[result_pos + 1] = word & 0xFF;
+    result_pos += 2;
+
+    if (*end_pos == '\0')
+      break;
+
+    if (*end_pos != ':')
+      return 0;
+
+    pos = end_pos + 1;
+    if (*pos == ':') {
+      if (double_colon_pos != -1)
+        return 0;
+      double_colon_pos = result_pos;
+      ++pos;
+    }
+  }
+
+  /* Finally move the data to the end in case the address contained '::'. */
+  if (result_pos < kIpv6AddressSize) {
+    if (double_colon_pos == -1)
+      return 0;
+    int move_size = result_pos - double_colon_pos;
+    int gap_size = kIpv6AddressSize - result_pos;
+    memmove(result + kIpv6AddressSize - move_size,
+            result + double_colon_pos, move_size);
+    memset(result + double_colon_pos, 0, gap_size);
+  }
+
+  /* Finally copy the result to the output buffer. */
+  memcpy(dst, result, sizeof(result));
+
+  return 1;
+}
+
+int inet_pton(int af, const char *src, void *dst) {
+  if (!src || !dst) {
+    return 0;
+  }
+  if (af == AF_INET) {
+    return inet_pton_v4(src, dst);
+  } else if (af == AF_INET6) {
+    return inet_pton_v6(src, dst);
+  }
+  errno = EAFNOSUPPORT;
+  return -1;
+}
+
+#endif  /* defined(PROVIDES_SOCKET_API) && !defined(__GLIBC__) */