Diff: utility/os2_stoip6.c

Revision:

16:269f652b4d0b

Parent:

14:7648334eb41b

diff -r 53715cc81c63 -r 269f652b4d0b utility/os2_stoip6.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/utility/os2_stoip6.c	Fri Jun 05 15:12:21 2020 +0000
@@ -0,0 +1,185 @@
+/*
+ * Copyright (c) 2014-2015 ARM Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ * Licensed under the Apache License, Version 2.0 (the License); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "mbed_version.h"
+
+#if MBED_MAJOR_VERSION == 2
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include "common_functions.h"
+#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
+ */
+bool stoip6(const char *ip6addr, size_t len, void *dest)
+{
+    uint8_t *addr;
+    const char *p, *q;
+    int_fast8_t field_no, coloncolon = -1;
+
+    addr = dest;
+
+    if (len > 39) { // Too long, not possible. We do not support IPv4-mapped IPv6 addresses
+        goto error;
+    }
+
+    // First go forward the string, until end, noting :: position if any
+    // 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)
+        addr = common_write_16_bit(hex(p), addr);
+        field_no++;
+
+        // 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;
+            }
+        }
+    }
+
+    if (coloncolon != -1) {
+        /* Insert zeros in the appropriate place */
+        uint_fast8_t head_size = 2 * coloncolon;
+        uint_fast8_t inserted_size = 2 * (8 - field_no);
+        uint_fast8_t tail_size = 16 - head_size - inserted_size;
+        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) { // 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)
+{
+    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;
+
+    for (;;) {
+        char c = *p++;
+        if ((c >= '0') && (c <= '9')) {
+            val = (val << 4) | (c - '0');
+        } else if ((c >= 'A') && (c <= 'F')) {
+            val = (val << 4) | (10 + (c - 'A'));
+        } else if ((c >= 'a') && (c <= 'f')) {
+            val = (val << 4) | (10 + (c - 'a'));
+        } else {
+            break; // Non hex character
+        }
+    }
+    return val;
+}
+#endif