Fix android crash for inet_ntop

src/network/stk_ipv6.cpp

@@ -26,7 +26,6 @@
 
 extern "C"
 {
-   WINSOCK_API_LINKAGE  PCSTR WSAAPI inet_ntop(INT Family, PVOID pAddr, PSTR pStringBuf, size_t StringBufSize);
    WINSOCK_API_LINKAGE  INT WSAAPI inet_pton(INT Family, PCSTR pszAddrString, PVOID pAddrBuf);
 }
 
@@ -48,6 +47,116 @@ extern "C"
 
 #include <string>
 
+// ============================================================================
+// Android STK seems to crash when using inet_ntop so we copy it from linux
+#define NS_IN6ADDRSZ 16
+#define NS_INT16SZ 2
+static const char *
+stk_inet_ntop4(const u_char *src, char *dst, socklen_t size)
+{
+    static const char fmt[] = "%u.%u.%u.%u";
+    char tmp[sizeof "255.255.255.255"];
+
+    if (sprintf(tmp, fmt, src[0], src[1], src[2], src[3]) >= (int)size)
+    {
+        return NULL;
+    }
+    return strcpy(dst, tmp);
+}
+
+static const char *
+stk_inet_ntop6(const uint8_t *src, char *dst, socklen_t size)
+{
+    /*
+    * Note that int32_t and int16_t need only be "at least" large enough
+    * to contain a value of the specified size.  On some systems, like
+    * Crays, there is no such thing as an integer variable with 16 bits.
+    * Keep this in mind if you think this function should have been coded
+    * to use pointer overlays.  All the world's not a VAX.
+    */
+    char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
+    struct { int base, len; } best, cur;
+    uint32_t words[NS_IN6ADDRSZ / NS_INT16SZ];
+    int i;
+    /*
+    * Preprocess:
+    *        Copy the input (bytewise) array into a wordwise array.
+    *        Find the longest run of 0x00's in src[] for :: shorthanding.
+    */
+    memset(words, '\0', sizeof words);
+    for (i = 0; i < NS_IN6ADDRSZ; i += 2)
+        words[i / 2] = (src[i] << 8) | src[i + 1];
+    best.base = -1;
+    cur.base = -1;
+    best.len = 0;
+    cur.len = 0;
+    for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++)
+    {
+        if (words[i] == 0)
+        {
+            if (cur.base == -1)
+                cur.base = i, cur.len = 1;
+            else
+                cur.len++;
+        }
+        else
+        {
+            if (cur.base != -1)
+            {
+                if (best.base == -1 || cur.len > best.len)
+                    best = cur;
+                cur.base = -1;
+            }
+        }
+    }
+    if (cur.base != -1)
+    {
+        if (best.base == -1 || cur.len > best.len)
+            best = cur;
+    }
+    if (best.base != -1 && best.len < 2)
+            best.base = -1;
+    /*
+    * Format the result.
+    */
+    tp = tmp;
+    for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++)
+    {
+        /* Are we inside the best run of 0x00's? */
+        if (best.base != -1 && i >= best.base && i < (best.base + best.len))
+        {
+            if (i == best.base)
+                *tp++ = ':';
+            continue;
+        }
+        /* Are we following an initial run of 0x00s or any real hex? */
+        if (i != 0)
+            *tp++ = ':';
+        /* Is this address an encapsulated IPv4? */
+        if (i == 6 && best.base == 0 &&
+            (best.len == 6 || (best.len == 5 && words[5] == 0xffff)))
+        {
+            if (!stk_inet_ntop4(src + 12, tp, sizeof tmp - (tp - tmp)))
+                return (NULL);
+            tp += strlen(tp);
+            break;
+        }
+        tp += sprintf(tp, "%x", words[i]);
+    }
+    /* Was it a trailing run of 0x00's? */
+    if (best.base != -1 && (best.base + best.len) == (NS_IN6ADDRSZ / NS_INT16SZ))
+        *tp++ = ':';
+    *tp++ = '\0';
+    /*
+     * Check for overflow, copy, and we're done.
+     */
+    if ((socklen_t)(tp - tmp) > size)
+    {
+        return NULL;
+    }
+    return strcpy(dst, tmp);
+}
+
 // ----------------------------------------------------------------------------
 bool isIPv4MappedAddress(const struct sockaddr_in6* in6)
 {
@@ -73,12 +182,12 @@ bool isIPv4MappedAddress(const struct sockaddr_in6* in6)
 // ----------------------------------------------------------------------------
 std::string getIPV6ReadableFromIn6(const struct sockaddr_in6* in)
 {
-    std::string result;
-    char ipv6[INET6_ADDRSTRLEN] = {};
-    struct in6_addr ipv6_addr = in->sin6_addr;
-    inet_ntop(AF_INET6, &ipv6_addr, ipv6, INET6_ADDRSTRLEN);
-    result = ipv6;
-    return result;
+    std::string ipv6;
+    ipv6.resize(INET6_ADDRSTRLEN, 0);
+    stk_inet_ntop6(in->sin6_addr.s6_addr, &ipv6[0], INET6_ADDRSTRLEN);
+    size_t len = strlen(ipv6.c_str());
+    ipv6.resize(len);
+    return ipv6;
 }   // getIPV6ReadableFromIn6
 
 // ----------------------------------------------------------------------------