Add v6 support to IPAddress to match ArduinoCore-API (espressif#7174)

* feat(ipaddress): add support for ipv6 type, following arduinocore api

* feat(ipaddress): align with latest arduinocore api

---------

Co-authored-by: Me No Dev <[email protected]>

Author: sgryphon

Diff for: cores/esp32/IPAddress.cpp

@@ -20,78 +20,244 @@
 #include <Arduino.h>
 #include <IPAddress.h>
 #include <Print.h>
+#include <StreamString.h>
 
-IPAddress::IPAddress()
+IPAddress::IPAddress() : IPAddress(IPv4) {}
+
+IPAddress::IPAddress(IPType ip_type)
 {
-    _address.dword = 0;
+    _type = ip_type;
+    memset(_address.bytes, 0, sizeof(_address.bytes));
 }
 
 IPAddress::IPAddress(uint8_t first_octet, uint8_t second_octet, uint8_t third_octet, uint8_t fourth_octet)
 {
-    _address.bytes[0] = first_octet;
-    _address.bytes[1] = second_octet;
-    _address.bytes[2] = third_octet;
-    _address.bytes[3] = fourth_octet;
+    _type = IPv4;
+    memset(_address.bytes, 0, sizeof(_address.bytes));
+    _address.bytes[IPADDRESS_V4_BYTES_INDEX] = first_octet;
+    _address.bytes[IPADDRESS_V4_BYTES_INDEX + 1] = second_octet;
+    _address.bytes[IPADDRESS_V4_BYTES_INDEX + 2] = third_octet;
+    _address.bytes[IPADDRESS_V4_BYTES_INDEX + 3] = fourth_octet;
+}
+
+IPAddress::IPAddress(uint8_t o1, uint8_t o2, uint8_t o3, uint8_t o4, uint8_t o5, uint8_t o6, uint8_t o7, uint8_t o8, uint8_t o9, uint8_t o10, uint8_t o11, uint8_t o12, uint8_t o13, uint8_t o14, uint8_t o15, uint8_t o16) {
+    _type = IPv6;
+    _address.bytes[0] = o1;
+    _address.bytes[1] = o2;
+    _address.bytes[2] = o3;
+    _address.bytes[3] = o4;
+    _address.bytes[4] = o5;
+    _address.bytes[5] = o6;
+    _address.bytes[6] = o7;
+    _address.bytes[7] = o8;
+    _address.bytes[8] = o9;
+    _address.bytes[9] = o10;
+    _address.bytes[10] = o11;
+    _address.bytes[11] = o12;
+    _address.bytes[12] = o13;
+    _address.bytes[13] = o14;
+    _address.bytes[14] = o15;
+    _address.bytes[15] = o16;
 }
 
 IPAddress::IPAddress(uint32_t address)
 {
-    _address.dword = address;
+    // IPv4 only
+    _type = IPv4;
+    memset(_address.bytes, 0, sizeof(_address.bytes));
+    _address.dword[IPADDRESS_V4_DWORD_INDEX] = address;
+
+    // NOTE on conversion/comparison and uint32_t:
+    // These conversions are host platform dependent.
+    // There is a defined integer representation of IPv4 addresses,
+    // based on network byte order (will be the value on big endian systems),
+    // e.g. http://2398766798 is the same as http://142.250.70.206,
+    // However on little endian systems the octets 0x83, 0xFA, 0x46, 0xCE,
+    // in that order, will form the integer (uint32_t) 3460758158 .
+}
+
+IPAddress::IPAddress(const uint8_t *address) : IPAddress(IPv4, address) {}
+
+IPAddress::IPAddress(IPType ip_type, const uint8_t *address)
+{
+    _type = ip_type;
+    if (ip_type == IPv4) {
+        memset(_address.bytes, 0, sizeof(_address.bytes));
+        memcpy(&_address.bytes[IPADDRESS_V4_BYTES_INDEX], address, sizeof(uint32_t));
+    } else {
+        memcpy(_address.bytes, address, sizeof(_address.bytes));
+    }
 }
 
-IPAddress::IPAddress(const uint8_t *address)
+IPAddress::IPAddress(const char *address)
 {
-    memcpy(_address.bytes, address, sizeof(_address.bytes));
+    fromString(address);
 }
 
 IPAddress& IPAddress::operator=(const uint8_t *address)
 {
-    memcpy(_address.bytes, address, sizeof(_address.bytes));
+    // IPv4 only conversion from byte pointer
+    _type = IPv4;
+    memset(_address.bytes, 0, sizeof(_address.bytes));
+    memcpy(&_address.bytes[IPADDRESS_V4_BYTES_INDEX], address, sizeof(uint32_t));
+    return *this;
+}
+
+IPAddress& IPAddress::operator=(const char *address)
+{
+    fromString(address);
     return *this;
 }
 
 IPAddress& IPAddress::operator=(uint32_t address)
 {
-    _address.dword = address;
+    // IPv4 conversion
+    // See note on conversion/comparison and uint32_t
+    _type = IPv4;
+    memset(_address.bytes, 0, sizeof(_address.bytes));
+    _address.dword[IPADDRESS_V4_DWORD_INDEX] = address;
     return *this;
 }
 
+bool IPAddress::operator==(const IPAddress& addr) const
+{
+    return (addr._type == _type)
+        && (memcmp(addr._address.bytes, _address.bytes, sizeof(_address.bytes)) == 0);
+}
+
 bool IPAddress::operator==(const uint8_t* addr) const
 {
-    return memcmp(addr, _address.bytes, sizeof(_address.bytes)) == 0;
+    // IPv4 only comparison to byte pointer
+    // Can't support IPv6 as we know our type, but not the length of the pointer
+    return _type == IPv4 && memcmp(addr, &_address.bytes[IPADDRESS_V4_BYTES_INDEX], sizeof(uint32_t)) == 0;
+}
+
+uint8_t IPAddress::operator[](int index) const {
+    if (_type == IPv4) {
+        return _address.bytes[IPADDRESS_V4_BYTES_INDEX + index];
+    }
+    return _address.bytes[index];
+}
+
+uint8_t& IPAddress::operator[](int index) {
+    if (_type == IPv4) {
+        return _address.bytes[IPADDRESS_V4_BYTES_INDEX + index];
+    }
+    return _address.bytes[index];
 }
 
 size_t IPAddress::printTo(Print& p) const
 {
     size_t n = 0;
-    for(int i = 0; i < 3; i++) {
-        n += p.print(_address.bytes[i], DEC);
+
+    if (_type == IPv6) {
+        // IPv6 IETF canonical format: compress left-most longest run of two or more zero fields, lower case
+        int8_t longest_start = -1;
+        int8_t longest_length = 1;
+        int8_t current_start = -1;
+        int8_t current_length = 0;
+        for (int8_t f = 0; f < 8; f++) {
+            if (_address.bytes[f * 2] == 0 && _address.bytes[f * 2 + 1] == 0) {
+                if (current_start == -1) {
+                    current_start = f;
+                    current_length = 1;
+                } else {
+                    current_length++;
+                }
+                if (current_length > longest_length) {
+                    longest_start = current_start;
+                    longest_length = current_length;
+                }
+            } else {
+                current_start = -1;
+            }
+        }
+        for (int f = 0; f < 8; f++) {
+            if (f < longest_start || f >= longest_start + longest_length) {
+                uint8_t c1 = _address.bytes[f * 2] >> 4;
+                uint8_t c2 = _address.bytes[f * 2] & 0xf;
+                uint8_t c3 = _address.bytes[f * 2 + 1] >> 4;
+                uint8_t c4 = _address.bytes[f * 2 + 1] & 0xf;
+                if (c1 > 0) {
+                    n += p.print((char)(c1 < 10 ? '0' + c1 : 'a' + c1 - 10));
+                }
+                if (c1 > 0 || c2 > 0) {
+                    n += p.print((char)(c2 < 10 ? '0' + c2 : 'a' + c2 - 10));
+                }
+                if (c1 > 0 || c2 > 0 || c3 > 0) {
+                    n += p.print((char)(c3 < 10 ? '0' + c3 : 'a' + c3 - 10));
+                }
+                n += p.print((char)(c4 < 10 ? '0' + c4 : 'a' + c4 - 10));
+                if (f < 7) {
+                    n += p.print(':');
+                }
+            } else if (f == longest_start) {
+                if (longest_start == 0) {
+                    n += p.print(':');
+                }
+                n += p.print(':');
+            }
+        }
+        return n;
+    }
+
+    // IPv4
+    for (int i =0; i < 3; i++)
+    {
+        n += p.print(_address.bytes[IPADDRESS_V4_BYTES_INDEX + i], DEC);
         n += p.print('.');
     }
-    n += p.print(_address.bytes[3], DEC);
+    n += p.print(_address.bytes[IPADDRESS_V4_BYTES_INDEX + 3], DEC);
     return n;
 }
 
-String IPAddress::toString() const
+String IPAddress::toString4() const
 {
     char szRet[16];
-    sprintf(szRet,"%u.%u.%u.%u", _address.bytes[0], _address.bytes[1], _address.bytes[2], _address.bytes[3]);
+    snprintf(szRet, sizeof(szRet), "%u.%u.%u.%u", _address.bytes[IPADDRESS_V4_BYTES_INDEX], _address.bytes[IPADDRESS_V4_BYTES_INDEX + 1], _address.bytes[IPADDRESS_V4_BYTES_INDEX + 2], _address.bytes[IPADDRESS_V4_BYTES_INDEX + 3]);
     return String(szRet);
 }
 
+String IPAddress::toString6() const
+{
+    StreamString s;
+    s.reserve(40);
+    printTo(s);
+    return s;
+}
+
+String IPAddress::toString() const
+{
+    if (_type == IPv4) {
+        return toString4();
+    } else {
+        return toString6();
+    }
+}
+
 bool IPAddress::fromString(const char *address)
+{
+    if (!fromString4(address))
+    {
+        return fromString6(address);
+    }
+    return true;
+}
+
+bool IPAddress::fromString4(const char *address)
 {
     // TODO: add support for "a", "a.b", "a.b.c" formats
 
-    uint16_t acc = 0; // Accumulator
+    int16_t acc = -1; // Accumulator
     uint8_t dots = 0;
 
+    memset(_address.bytes, 0, sizeof(_address.bytes));
     while (*address)
     {
         char c = *address++;
         if (c >= '0' && c <= '9')
         {
-            acc = acc * 10 + (c - '0');
+            acc = (acc < 0) ? (c - '0') : acc * 10 + (c - '0');
             if (acc > 255) {
                 // Value out of [0..255] range
                 return false;
@@ -100,11 +266,15 @@ bool IPAddress::fromString(const char *address)
         else if (c == '.')
         {
             if (dots == 3) {
-                // Too much dots (there must be 3 dots)
+                // Too many dots (there must be 3 dots)
                 return false;
             }
-            _address.bytes[dots++] = acc;
-            acc = 0;
+            if (acc < 0) {
+                /* No value between dots, e.g. '1..' */
+                return false;
+            }
+            _address.bytes[IPADDRESS_V4_BYTES_INDEX + dots++] = acc;
+            acc = -1;
         }
         else
         {
@@ -117,7 +287,80 @@ bool IPAddress::fromString(const char *address)
         // Too few dots (there must be 3 dots)
         return false;
     }
-    _address.bytes[3] = acc;
+    if (acc < 0) {
+        /* No value between dots, e.g. '1..' */
+        return false;
+    }
+    _address.bytes[IPADDRESS_V4_BYTES_INDEX + 3] = acc;
+    _type = IPv4;
+    return true;
+}
+
+bool IPAddress::fromString6(const char *address) {
+    uint32_t acc = 0; // Accumulator
+    int colons = 0, double_colons = -1;
+
+    while (*address)
+    {
+        char c = tolower(*address++);
+        if (isalnum(c) && c <= 'f') {
+            if (c >= 'a')
+                c -= 'a' - '0' - 10;
+            acc = acc * 16 + (c - '0');
+            if (acc > 0xffff)
+                // Value out of range
+                return false;
+        }
+        else if (c == ':') {
+            if (*address == ':') {
+                if (double_colons >= 0) {
+                    // :: allowed once
+                    return false;
+                }
+                if (*address != '\0' && *(address + 1) == ':') {
+                    // ::: not allowed
+                    return false;
+                }
+                // remember location
+                double_colons = colons + !!acc;
+                address++;
+            } else if (*address == '\0') {
+                // can't end with a single colon
+                return false;
+            }
+            if (colons == 7)
+                // too many separators
+                return false;
+            _address.bytes[colons * 2] = acc >> 8;
+            _address.bytes[colons * 2 + 1] = acc & 0xff;
+            colons++;
+            acc = 0;
+        }
+        else
+            // Invalid char
+            return false;
+    }
+
+    if (double_colons == -1 && colons != 7) {
+        // Too few separators
+        return false;
+    }
+    if (double_colons > -1 && colons > 6) {
+        // Too many segments (double colon must be at least one zero field)
+        return false;
+    }
+    _address.bytes[colons * 2] = acc >> 8;
+    _address.bytes[colons * 2 + 1] = acc & 0xff;
+    colons++;
+
+    if (double_colons != -1) {
+        for (int i = colons * 2 - double_colons * 2 - 1; i >= 0; i--)
+            _address.bytes[16 - colons * 2 + double_colons * 2 + i] = _address.bytes[double_colons * 2 + i];
+        for (int i = double_colons * 2; i < 16 - colons * 2 + double_colons * 2; i++)
+            _address.bytes[i] = 0;
+    }
+
+    _type = IPv6;
     return true;
 }