MDEV-4051 INET6_ATON() and INET6_NTOA()

Backporting functions from MySQL-5.6:

- INET6_ATON()
- INET6_NTOA()
- IS_IPV4()
- IS_IPV4_COMPAT()
- IS_IPV4_MAPPED()
- IS_IPV6()

1 files changed, 704 insertions, 0 deletions

diff --git a/sql/item_inetfunc.cc b/sql/item_inetfunc.cc
index 9b2f1292db5..627ef728a2e 100644
--- a/sql/item_inetfunc.cc
+++ b/sql/item_inetfunc.cc
@@ -16,6 +16,17 @@
 
 #include "item_inetfunc.h"
 
+#include "my_net.h"
+
+///////////////////////////////////////////////////////////////////////////
+
+static const int IN_ADDR_SIZE= sizeof (in_addr);
+static const int IN6_ADDR_SIZE= sizeof (in6_addr);
+static const int IN6_ADDR_NUM_WORDS= IN6_ADDR_SIZE / 2;
+
+static const char HEX_DIGITS[]= "0123456789abcdef";
+
+///////////////////////////////////////////////////////////////////////////
 
 longlong Item_func_inet_aton::val_int()
 {
@@ -124,3 +135,696 @@ String* Item_func_inet_ntoa::val_str(String* str)
 
   return str;
 }
+
+///////////////////////////////////////////////////////////////////////////
+
+/**
+  Check the function argument, handle errors properly.
+
+  @return The function value.
+*/
+
+longlong Item_func_inet_bool_base::val_int()
+{
+  DBUG_ASSERT(fixed);
+
+  if (args[0]->result_type() != STRING_RESULT) // String argument expected
+    return 0;
+
+  String buffer;
+  String *arg_str= args[0]->val_str(&buffer);
+
+  if (!arg_str) // Out-of memory happened. The error has been reported.
+    return 0;   // Or: the underlying field is NULL
+
+  return calc_value(arg_str) ? 1 : 0;
+}
+
+///////////////////////////////////////////////////////////////////////////
+
+/**
+  Check the function argument, handle errors properly.
+
+  @param [out] buffer Buffer for string operations.
+
+  @return The function value.
+*/
+
+String *Item_func_inet_str_base::val_str_ascii(String *buffer)
+{
+  DBUG_ASSERT(fixed);
+
+  if (args[0]->result_type() != STRING_RESULT) // String argument expected
+  {
+    null_value= true;
+    return NULL;
+  }
+
+  String *arg_str= args[0]->val_str(buffer);
+  if (!arg_str) // Out-of memory happened. The error has been reported.
+  {             // Or: the underlying field is NULL
+    null_value= true;
+    return NULL;
+  }
+
+  null_value= !calc_value(arg_str, buffer);
+
+  return null_value ? NULL : buffer;
+}
+
+///////////////////////////////////////////////////////////////////////////
+
+/**
+  Tries to convert given string to binary IPv4-address representation.
+  This is a portable alternative to inet_pton(AF_INET).
+
+  @param      str          String to convert.
+  @param      str_len      String length.
+  @param[out] ipv4_address Buffer to store IPv4-address.
+
+  @return Completion status.
+  @retval false Given string does not represent an IPv4-address.
+  @retval true  The string has been converted sucessfully.
+
+  @note The problem with inet_pton() is that it treats leading zeros in
+  IPv4-part differently on different platforms.
+*/
+
+static bool str_to_ipv4(const char *str, int str_length, in_addr *ipv4_address)
+{
+  if (str_length < 7)
+  {
+    DBUG_PRINT("error", ("str_to_ipv4(%.*s): "
+                         "invalid IPv4 address: too short.",
+                         str_length, str));
+    return false;
+  }
+
+  if (str_length > 15)
+  {
+    DBUG_PRINT("error", ("str_to_ipv4(%.*s): "
+                         "invalid IPv4 address: too long.",
+                         str_length, str));
+    return false;
+  }
+
+  unsigned char *ipv4_bytes= (unsigned char *) ipv4_address;
+  const char *p= str;
+  int byte_value= 0;
+  int chars_in_group= 0;
+  int dot_count= 0;
+  char c= 0;
+
+  while (((p - str) < str_length) && *p)
+  {
+    c= *p++;
+
+    if (my_isdigit(&my_charset_latin1, c))
+    {
+      ++chars_in_group;
+
+      if (chars_in_group > 3)
+      {
+        DBUG_PRINT("error", ("str_to_ipv4(%.*s): invalid IPv4 address: "
+                             "too many characters in a group.",
+                             str_length, str));
+        return false;
+      }
+
+      byte_value= byte_value * 10 + (c - '0');
+
+      if (byte_value > 255)
+      {
+        DBUG_PRINT("error", ("str_to_ipv4(%.*s): invalid IPv4 address: "
+                             "invalid byte value.",
+                             str_length, str));
+        return false;
+      }
+    }
+    else if (c == '.')
+    {
+      if (chars_in_group == 0)
+      {
+        DBUG_PRINT("error", ("str_to_ipv4(%.*s): invalid IPv4 address: "
+                             "too few characters in a group.",
+                             str_length, str));
+        return false;
+      }
+
+      ipv4_bytes[dot_count]= (unsigned char) byte_value;
+
+      ++dot_count;
+      byte_value= 0;
+      chars_in_group= 0;
+
+      if (dot_count > 3)
+      {
+        DBUG_PRINT("error", ("str_to_ipv4(%.*s): invalid IPv4 address: "
+                             "too many dots.", str_length, str));
+        return false;
+      }
+    }
+    else
+    {
+      DBUG_PRINT("error", ("str_to_ipv4(%.*s): invalid IPv4 address: "
+                           "invalid character at pos %d.",
+                           str_length, str, (int) (p - str)));
+      return false;
+    }
+  }
+
+  if (c == '.')
+  {
+    DBUG_PRINT("error", ("str_to_ipv4(%.*s): invalid IPv4 address: "
+                         "ending at '.'.", str_length, str));
+    return false;
+  }
+
+  if (dot_count != 3)
+  {
+    DBUG_PRINT("error", ("str_to_ipv4(%.*s): invalid IPv4 address: "
+                         "too few groups.",
+                         str_length, str));
+    return false;
+  }
+
+  ipv4_bytes[3]= (unsigned char) byte_value;
+
+  DBUG_PRINT("info", ("str_to_ipv4(%.*s): valid IPv4 address: %d.%d.%d.%d",
+                      str_length, str,
+                      ipv4_bytes[0], ipv4_bytes[1],
+                      ipv4_bytes[2], ipv4_bytes[3]));
+  return true;
+}
+
+///////////////////////////////////////////////////////////////////////////
+
+/**
+  Tries to convert given string to binary IPv6-address representation.
+  This is a portable alternative to inet_pton(AF_INET6).
+
+  @param      str          String to convert.
+  @param      str_len      String length.
+  @param[out] ipv6_address Buffer to store IPv6-address.
+
+  @return Completion status.
+  @retval false Given string does not represent an IPv6-address.
+  @retval true  The string has been converted sucessfully.
+
+  @note The problem with inet_pton() is that it treats leading zeros in
+  IPv4-part differently on different platforms.
+*/
+
+static bool str_to_ipv6(const char *str, int str_length, in6_addr *ipv6_address)
+{
+  if (str_length < 2)
+  {
+    DBUG_PRINT("error", ("str_to_ipv6(%.*s): invalid IPv6 address: too short.",
+                         str_length, str));
+    return false;
+  }
+
+  if (str_length > 8 * 4 + 7)
+  {
+    DBUG_PRINT("error", ("str_to_ipv6(%.*s): invalid IPv6 address: too long.",
+                         str_length, str));
+    return false;
+  }
+
+  memset(ipv6_address, 0, IN6_ADDR_SIZE);
+
+  const char *p= str;
+
+  if (*p == ':')
+  {
+    ++p;
+
+    if (*p != ':')
+    {
+      DBUG_PRINT("error", ("str_to_ipv6(%.*s): invalid IPv6 address: "
+                           "can not start with ':x'.", str_length, str));
+      return false;
+    }
+  }
+
+  char *ipv6_bytes= (char *) ipv6_address;
+  char *ipv6_bytes_end= ipv6_bytes + IN6_ADDR_SIZE;
+  char *dst= ipv6_bytes;
+  char *gap_ptr= NULL;
+  const char *group_start_ptr= p;
+  int chars_in_group= 0;
+  int group_value= 0;
+
+  while (((p - str) < str_length) && *p)
+  {
+    char c= *p++;
+
+    if (c == ':')
+    {
+      group_start_ptr= p;
+
+      if (!chars_in_group)
+      {
+        if (gap_ptr)
+        {
+          DBUG_PRINT("error", ("str_to_ipv6(%.*s): invalid IPv6 address: "
+                               "too many gaps(::).", str_length, str));
+          return false;
+        }
+
+        gap_ptr= dst;
+        continue;
+      }
+
+      if (!*p || ((p - str) >= str_length))
+      {
+        DBUG_PRINT("error", ("str_to_ipv6(%.*s): invalid IPv6 address: "
+                             "ending at ':'.", str_length, str));
+        return false;
+      }
+
+      if (dst + 2 > ipv6_bytes_end)
+      {
+        DBUG_PRINT("error", ("str_to_ipv6(%.*s): invalid IPv6 address: "
+                             "too many groups (1).", str_length, str));
+        return false;
+      }
+
+      dst[0]= (unsigned char) (group_value >> 8) & 0xff;
+      dst[1]= (unsigned char) group_value & 0xff;
+      dst += 2;
+
+      chars_in_group= 0;
+      group_value= 0;
+    }
+    else if (c == '.')
+    {
+      if (dst + IN_ADDR_SIZE > ipv6_bytes_end)
+      {
+        DBUG_PRINT("error", ("str_to_ipv6(%.*s): invalid IPv6 address: "
+                             "unexpected IPv4-part.", str_length, str));
+        return false;
+      }
+
+      if (!str_to_ipv4(group_start_ptr,
+                       str + str_length - group_start_ptr,
+                       (in_addr *) dst))
+      {
+        DBUG_PRINT("error", ("str_to_ipv6(%.*s): invalid IPv6 address: "
+                             "invalid IPv4-part.", str_length, str));
+        return false;
+      }
+
+      dst += IN_ADDR_SIZE;
+      chars_in_group= 0;
+
+      break;
+    }
+    else
+    {
+      const char *hdp= strchr(HEX_DIGITS, my_tolower(&my_charset_latin1, c));
+
+      if (!hdp)
+      {
+        DBUG_PRINT("error", ("str_to_ipv6(%.*s): invalid IPv6 address: "
+                             "invalid character at pos %d.",
+                             str_length, str, (int) (p - str)));
+        return false;
+      }
+
+      if (chars_in_group >= 4)
+      {
+        DBUG_PRINT("error", ("str_to_ipv6(%.*s): invalid IPv6 address: "
+                             "too many digits in group.",
+                             str_length, str));
+        return false;
+      }
+
+      group_value <<= 4;
+      group_value |= hdp - HEX_DIGITS;
+
+      DBUG_ASSERT(group_value <= 0xffff);
+
+      ++chars_in_group;
+    }
+  }
+
+  if (chars_in_group > 0)
+  {
+    if (dst + 2 > ipv6_bytes_end)
+    {
+      DBUG_PRINT("error", ("str_to_ipv6(%.*s): invalid IPv6 address: "
+                           "too many groups (2).", str_length, str));
+      return false;
+    }
+
+    dst[0]= (unsigned char) (group_value >> 8) & 0xff;
+    dst[1]= (unsigned char) group_value & 0xff;
+    dst += 2;
+  }
+
+  if (gap_ptr)
+  {
+    if (dst == ipv6_bytes_end)
+    {
+      DBUG_PRINT("error", ("str_to_ipv6(%.*s): invalid IPv6 address: "
+                           "no room for a gap (::).", str_length, str));
+      return false;
+    }
+
+    int bytes_to_move= dst - gap_ptr;
+
+    for (int i= 1; i <= bytes_to_move; ++i)
+    {
+      ipv6_bytes_end[-i]= gap_ptr[bytes_to_move - i];
+      gap_ptr[bytes_to_move - i]= 0;
+    }
+
+    dst= ipv6_bytes_end;
+  }
+
+  if (dst < ipv6_bytes_end)
+  {
+    DBUG_PRINT("error", ("str_to_ipv6(%.*s): invalid IPv6 address: "
+                         "too few groups.", str_length, str));
+    return false;
+  }
+
+  return true;
+}
+
+///////////////////////////////////////////////////////////////////////////
+
+/**
+  Converts IPv4-binary-address to a string. This function is a portable
+  alternative to inet_ntop(AF_INET).
+
+  @param[in] ipv4 IPv4-address data (byte array)
+  @param[out] str A buffer to store string representation of IPv4-address.
+                  It must be at least of INET_ADDRSTRLEN.
+
+  @note The problem with inet_ntop() is that it is available starting from
+  Windows Vista, but the minimum supported version is Windows 2000.
+*/
+
+static void ipv4_to_str(const in_addr *ipv4, char *str)
+{
+  const unsigned char *ipv4_bytes= (const unsigned char *) ipv4;
+
+  sprintf(str, "%d.%d.%d.%d",
+          ipv4_bytes[0], ipv4_bytes[1], ipv4_bytes[2], ipv4_bytes[3]);
+}
+///////////////////////////////////////////////////////////////////////////
+
+/**
+  Converts IPv6-binary-address to a string. This function is a portable
+  alternative to inet_ntop(AF_INET6).
+
+  @param[in] ipv6 IPv6-address data (byte array)
+  @param[out] str A buffer to store string representation of IPv6-address.
+                  It must be at least of INET6_ADDRSTRLEN.
+
+  @note The problem with inet_ntop() is that it is available starting from
+  Windows Vista, but out the minimum supported version is Windows 2000.
+*/
+
+static void ipv6_to_str(const in6_addr *ipv6, char *str)
+{
+  struct Region
+  {
+    int pos;
+    int length;
+  };
+
+  const unsigned char *ipv6_bytes= (const unsigned char *) ipv6;
+
+  // 1. Translate IPv6-address bytes to words.
+  // We can't just cast to short, because it's not guaranteed
+  // that sizeof (short) == 2. So, we have to make a copy.
+
+  uint16 ipv6_words[IN6_ADDR_NUM_WORDS];
+
+  for (int i= 0; i < IN6_ADDR_NUM_WORDS; ++i)
+    ipv6_words[i]= (ipv6_bytes[2 * i] << 8) + ipv6_bytes[2 * i + 1];
+
+  // 2. Find "the gap" -- longest sequence of zeros in IPv6-address.
+
+  Region gap= { -1, -1 };
+
+  {
+    Region rg= { -1, -1 };
+
+    for (int i = 0; i < IN6_ADDR_NUM_WORDS; ++i)
+    {
+      if (ipv6_words[i] != 0)
+      {
+        if (rg.pos >= 0)
+        {
+          if (rg.length > gap.length)
+            gap= rg;
+
+          rg.pos= -1;
+          rg.length= -1;
+        }
+      }
+      else
+      {
+        if (rg.pos >= 0)
+        {
+          ++rg.length;
+        }
+        else
+        {
+          rg.pos= i;
+          rg.length= 1;
+        }
+      }
+    }
+
+    if (rg.pos >= 0)
+    {
+      if (rg.length > gap.length)
+        gap= rg;
+    }
+  }
+
+  // 3. Convert binary data to string.
+
+  char *p= str;
+
+  for (int i = 0; i < IN6_ADDR_NUM_WORDS; ++i)
+  {
+    if (i == gap.pos)
+    {
+      // We're at the gap position. We should put trailing ':' and jump to
+      // the end of the gap.
+
+      if (i == 0)
+      {
+        // The gap starts from the beginning of the data -- leading ':'
+        // should be put additionally.
+
+        *p= ':';
+        ++p;
+      }
+
+      *p= ':';
+      ++p;
+
+      i += gap.length - 1;
+    }
+    else if (i == 6 && gap.pos == 0 &&
+             (gap.length == 6 ||                           // IPv4-compatible
+              (gap.length == 5 && ipv6_words[5] == 0xffff) // IPv4-mapped
+             ))
+    {
+      // The data represents either IPv4-compatible or IPv4-mapped address.
+      // The IPv6-part (zeros or zeros + ffff) has been already put into
+      // the string (str). Now it's time to dump IPv4-part.
+
+      ipv4_to_str((const in_addr *) (ipv6_bytes + 12), p);
+      return;
+    }
+    else
+    {
+      // Usual IPv6-address-field. Print it out using lower-case
+      // hex-letters without leading zeros (recommended IPv6-format).
+      //
+      // If it is not the last field, append closing ':'.
+
+      p += sprintf(p, "%x", ipv6_words[i]);
+
+      if (i != IN6_ADDR_NUM_WORDS - 1)
+      {
+        *p= ':';
+        ++p;
+      }
+    }
+  }
+
+  *p= 0;
+}
+
+///////////////////////////////////////////////////////////////////////////
+
+/**
+  Converts IP-address-string to IP-address-data.
+
+  @param       arg    IP-address-string.
+  @param [out] buffer Buffer to store IP-address-data.
+
+  @return Completion status.
+  @retval false Given string does not represent an IP-address.
+  @retval true  The string has been converted sucessfully.
+*/
+
+bool Item_func_inet6_aton::calc_value(String *arg, String *buffer)
+{
+  // ipv4-string -> varbinary(4)
+  // ipv6-string -> varbinary(16)
+
+  in_addr ipv4_address;
+  in6_addr ipv6_address;
+
+  if (str_to_ipv4(arg->ptr(), arg->length(), &ipv4_address))
+  {
+    buffer->length(0);
+    buffer->append((char *) &ipv4_address, sizeof (in_addr), &my_charset_bin);
+
+    return true;
+  }
+
+  if (str_to_ipv6(arg->ptr(), arg->length(), &ipv6_address))
+  {
+    buffer->length(0);
+    buffer->append((char *) &ipv6_address, sizeof (in6_addr), &my_charset_bin);
+
+    return true;
+  }
+
+  return false;
+}
+
+///////////////////////////////////////////////////////////////////////////
+
+/**
+  Converts IP-address-data to IP-address-string.
+
+  @param       arg    IP-address-data.
+  @param [out] buffer Buffer to store IP-address-string.
+
+  @return Completion status.
+  @retval false The argument does not correspond to IP-address.
+  @retval true  The string has been converted sucessfully.
+*/
+
+bool Item_func_inet6_ntoa::calc_value(String *arg, String *buffer)
+{
+  if (arg->charset() != &my_charset_bin)
+    return false;
+
+  if ((int) arg->length() == IN_ADDR_SIZE)
+  {
+    char str[INET_ADDRSTRLEN];
+
+    ipv4_to_str((const in_addr *) arg->ptr(), str);
+
+    buffer->length(0);
+    buffer->append(str, (uint32) strlen(str), &my_charset_latin1);
+
+    return true;
+  }
+  else if ((int) arg->length() == IN6_ADDR_SIZE)
+  {
+    char str[INET6_ADDRSTRLEN];
+
+    ipv6_to_str((const in6_addr *) arg->ptr(), str);
+
+    buffer->length(0);
+    buffer->append(str, (uint32) strlen(str), &my_charset_latin1);
+
+    return true;
+  }
+
+  DBUG_PRINT("info",
+             ("INET6_NTOA(): varbinary(4) or varbinary(16) expected."));
+  return false;
+}
+
+///////////////////////////////////////////////////////////////////////////
+
+/**
+  Checks if the passed string represents an IPv4-address.
+
+  @param arg The string to check.
+
+  @return Check status.
+  @retval false The passed string does not represent an IPv4-address.
+  @retval true  The passed string represents an IPv4-address.
+*/
+
+bool Item_func_is_ipv4::calc_value(const String *arg)
+{
+  in_addr ipv4_address;
+
+  return str_to_ipv4(arg->ptr(), arg->length(), &ipv4_address);
+}
+
+///////////////////////////////////////////////////////////////////////////
+
+/**
+  Checks if the passed string represents an IPv6-address.
+
+  @param arg The string to check.
+
+  @return Check status.
+  @retval false The passed string does not represent an IPv6-address.
+  @retval true  The passed string represents an IPv6-address.
+*/
+
+bool Item_func_is_ipv6::calc_value(const String *arg)
+{
+  in6_addr ipv6_address;
+
+  return str_to_ipv6(arg->ptr(), arg->length(), &ipv6_address);
+}
+
+///////////////////////////////////////////////////////////////////////////
+
+/**
+  Checks if the passed IPv6-address is an IPv4-compat IPv6-address.
+
+  @param arg The IPv6-address to check.
+
+  @return Check status.
+  @retval false The passed IPv6-address is not an IPv4-compatible IPv6-address.
+  @retval true  The passed IPv6-address is an IPv4-compatible IPv6-address.
+*/
+
+bool Item_func_is_ipv4_compat::calc_value(const String *arg)
+{
+  if ((int) arg->length() != IN6_ADDR_SIZE || arg->charset() != &my_charset_bin)
+    return false;
+
+  return IN6_IS_ADDR_V4COMPAT((struct in6_addr *) arg->ptr());
+}
+
+///////////////////////////////////////////////////////////////////////////
+
+/**
+  Checks if the passed IPv6-address is an IPv4-mapped IPv6-address.
+
+  @param arg The IPv6-address to check.
+
+  @return Check status.
+  @retval false The passed IPv6-address is not an IPv4-mapped IPv6-address.
+  @retval true  The passed IPv6-address is an IPv4-mapped IPv6-address.
+*/
+
+bool Item_func_is_ipv4_mapped::calc_value(const String *arg)
+{
+  if ((int) arg->length() != IN6_ADDR_SIZE || arg->charset() != &my_charset_bin)
+    return false;
+
+  return IN6_IS_ADDR_V4MAPPED((struct in6_addr *) arg->ptr());
+}