Squashed 'features/frameworks/nanostack-libservice/' changes from 2705b9b..5eb2f3f

5eb2f3f Make stoip6_prefix return a failure state when the core parser fails
901fdbb Add a couple of unit tests validating the more aggressive IPv6 parser
de201a3 Make stoip6 return whether the conversion succeed
e6ce3a8 Add new function stoip6_prefix (#75)
8ef1930 Revert "Make stoip6 return whether the conversion succeed" (#73)
6a18702 Merge pull request #72 from Taiki-San/ipv6
5efa0ff Add a couple of unit tests validating the more aggressive IPv6 parser
3b2c19f Make stoip6 return whether the conversion succeed

git-subtree-dir: features/frameworks/nanostack-libservice
git-subtree-split: 5eb2f3f4592aa00915f1bb37ba9cbc109146734d

Author: Arto Kinnunen

mbed-client-libservice/ip6string.h

@@ -58,9 +58,10 @@ uint_fast8_t ip6_prefix_tos(const void *prefix, uint_fast8_t prefix_len, char *p
  *
  * \param ip6addr IPv6 address in string format.
  * \param len Lenght of ipv6 string, maximum of 41.
- * \param dest buffer for address. MUST be 16 bytes.
+ * \param dest buffer for address. MUST be 16 bytes. Filled with 0 on error.
+ * \return boolean set to true if conversion succeed, false if it didn't
  */
-void stoip6(const char *ip6addr, size_t len, void *dest);
+bool stoip6(const char *ip6addr, size_t len, void *dest);
 /**
  * Find out numeric IPv6 address prefix length.
  *
@@ -69,6 +70,19 @@ void stoip6(const char *ip6addr, size_t len, void *dest);
  */
 unsigned char sipv6_prefixlength(const char *ip6addr);
 
+/**
+ * Convert numeric IPv6 address string with prefix to a binary.
+ *
+ * IPv4 tunneling addresses are not covered.
+ *
+ * \param ip6addr IPv6 address in string format.
+ * \param dest buffer for address. MUST be 16 bytes.
+ * \param prefix_len_out length of prefix, is set to -1 if no prefix given
+ *
+ * \return 0 on success, negative value otherwise. prefix_len_out contains prefix length.
+  */
+int stoip6_prefix(const char *ip6addr, void *dest, int_fast16_t *prefix_len_out);
+
 #ifdef __cplusplus
 }
 #endif

source/libip6string/stoip6.c

@@ -20,15 +20,17 @@
 #include "ip6string.h"
 
 static uint16_t hex(const char *p);
+static bool is_hex(char c);
 
 /**
  * Convert numeric IPv6 address string to a binary.
  * IPv4 tunnelling addresses are not covered.
  * \param ip6addr IPv6 address in string format.
  * \param len Length of ipv6 string.
  * \param dest buffer for address. MUST be 16 bytes.
+ * \return boolean set to true if conversion succeed, false if it didn't
  */
-void stoip6(const char *ip6addr, size_t len, void *dest)
+bool stoip6(const char *ip6addr, size_t len, void *dest)
 {
     uint8_t *addr;
     const char *p, *q;
@@ -37,23 +39,45 @@ void stoip6(const char *ip6addr, size_t len, void *dest)
     addr = dest;
 
     if (len > 39) { // Too long, not possible. We do not support IPv4-mapped IPv6 addresses
-        return;
+        goto error;
     }
 
     // First go forward the string, until end, noting :: position if any
-    for (field_no = 0, p = ip6addr; (len > (size_t)(p - ip6addr)) && *p && field_no < 8; p = q + 1) {
-        q = p;
-        // Seek for ':' or end
-        while (*q && (*q != ':')) {
-            q++;
+    // We're decrementing `len` as we go forward, and stop when it reaches 0
+    for (field_no = 0, p = ip6addr; len && *p; p = q + 1) {
+
+        for (q = p; len && *q && (*q != ':'); len -= 1) { // Seek for ':' or end
+            if (!is_hex(*q++)) { // There must only be hex characters besides ':'
+                goto error;
+            }
+        }
+
+        if ((q - p) > 4) { // We can't have more than 4 hex digits per segment
+            goto error;
+        }
+
+        if (field_no == 8) { // If the address goes farther than 8 segments
+            goto error;
         }
-        //Convert and write this part, (high-endian AKA network byte order)
+
+        // Convert and write this part, (high-endian AKA network byte order)
         addr = common_write_16_bit(hex(p), addr);
         field_no++;
-        //Check if we reached "::"
-        if ((len > (size_t)(q - ip6addr)) && *q && (q[0] == ':') && (q[1] == ':')) {
-            coloncolon = field_no;
-            q++;
+
+        // We handle the colons
+        if (len) {
+            // Check if we reached "::"
+            if (q[0] == ':' && q[1] == ':') {
+                if (coloncolon != -1) { // We are not supposed to see "::" more than once per address
+                    goto error;
+                }
+                coloncolon = field_no;
+                q++;
+                len -= 2;
+            }
+            else {
+                len -= 1;
+            }
         }
     }
 
@@ -65,19 +89,76 @@ void stoip6(const char *ip6addr, size_t len, void *dest)
         addr = dest;
         memmove(addr + head_size + inserted_size, addr + head_size, tail_size);
         memset(addr + head_size, 0, inserted_size);
-    } else if (field_no != 8) {
-        /* Should really report an error if we didn't get 8 fields */
-        memset(addr, 0, 16 - field_no * 2);
+    } else if (field_no != 8) { // Report an error if we didn't get 8 fields
+        goto error;
     }
+    return true;
+
+error:
+    // Fill the output buffer with 0 so we stick to the old failure behavior.
+    // We are however more agressive and wipe the entire address, and do so more often.
+    memset(dest, 0, 16);
+    return false;
 }
-unsigned char  sipv6_prefixlength(const char *ip6addr)
+
+unsigned char sipv6_prefixlength(const char *ip6addr)
 {
     char *ptr = strchr(ip6addr, '/');
     if (ptr) {
         return (unsigned char)strtoul(ptr + 1, 0, 10);
     }
     return 0;
 }
+
+int stoip6_prefix(const char *ip6addr, void *dest, int_fast16_t *prefix_len_out)
+{
+    size_t addr_len, total_len;
+    int_fast16_t prefix_length;
+
+    if (prefix_len_out) {
+        *prefix_len_out = -1;
+    }
+
+    total_len = addr_len = strlen(ip6addr);
+    const char *ptr = strchr(ip6addr, '/');
+    if (ptr) {
+        addr_len = ptr - ip6addr;
+        if (prefix_len_out) {
+            if (total_len - addr_len > 3) {
+                /* too many digits in prefix */
+                return -1;
+            }
+
+            prefix_length = strtoul(ptr + 1, 0, 10);
+            if (prefix_length <  0 || prefix_length > 128) {
+                /* prefix value illegal */
+                return -1;
+            }
+
+            *prefix_len_out = prefix_length;
+        }
+    }
+
+    if (!stoip6(ip6addr, addr_len, dest)) {
+        /* parser failure */
+        return -1;
+    }
+
+    return 0;
+}
+
+static bool is_hex(char c)
+{
+    // 'A' (0x41) and 'a' (0x61) are mapped in the ASCII table in such a way that masking the 0x20 bit turn 'a' in 'A'
+    if ((c & ~0x20) >= 'A' && (c & ~0x20) <= 'F')
+        return true;
+
+    if (c >= '0' && c <= '9')
+        return true;
+
+    return false;
+}
+
 static uint16_t hex(const char *p)
 {
     uint16_t val = 0;

test/libService/unittest/stoip6/main.cpp

@@ -25,3 +25,4 @@ int main(int ac, char **av)
 
 IMPORT_TEST_GROUP(stoip6);
 IMPORT_TEST_GROUP(stoip6_2);
+IMPORT_TEST_GROUP(stoip6_3);