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-rw-r--r--inet_ntop.c240
1 files changed, 127 insertions, 113 deletions
diff --git a/inet_ntop.c b/inet_ntop.c
index 60d91b9..74192c1 100644
--- a/inet_ntop.c
+++ b/inet_ntop.c
@@ -1,3 +1,5 @@
+/* $Id$ */
+
/* Copyright (c) 1996 by Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
@@ -63,144 +65,156 @@ static const char *inet_ntop6(const unsigned char *src, char *dst, size_t size);
/* char *
* inet_ntop(af, src, dst, size)
- * convert a network format address to presentation format.
+ * convert a network format address to presentation format.
* return:
- * pointer to presentation format address (`dst'), or NULL (see errno).
+ * pointer to presentation format address (`dst'), or NULL (see errno).
* author:
- * Paul Vixie, 1996.
+ * Paul Vixie, 1996.
*/
const char *
ares_inet_ntop(int af, const void *src, char *dst, size_t size)
{
-
- switch (af) {
- case AF_INET:
- return (inet_ntop4(src, dst, size));
- case AF_INET6:
- return (inet_ntop6(src, dst, size));
- default:
- errno = EAFNOSUPPORT;
- return (NULL);
- }
- /* NOTREACHED */
+ switch (af)
+ {
+ case AF_INET:
+ return (inet_ntop4(src, dst, size));
+ case AF_INET6:
+ return (inet_ntop6(src, dst, size));
+ default:
+ errno = EAFNOSUPPORT;
+ return (NULL);
+ }
+ /* NOTREACHED */
}
/* const char *
* inet_ntop4(src, dst, size)
- * format an IPv4 address, more or less like inet_ntoa()
+ * format an IPv4 address, more or less like inet_ntoa()
* return:
- * `dst' (as a const)
+ * `dst' (as a const)
* notes:
- * (1) uses no statics
- * (2) takes a unsigned char* not an in_addr as input
+ * (1) uses no statics
+ * (2) takes a unsigned char* not an in_addr as input
* author:
- * Paul Vixie, 1996.
+ * Paul Vixie, 1996.
*/
static const char *
inet_ntop4(const unsigned char *src, char *dst, size_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])) > size) {
- errno = ENOSPC;
- return (NULL);
- }
- strcpy(dst, tmp);
- return (dst);
+ 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])) > size)
+ {
+ errno = ENOSPC;
+ return (NULL);
+ }
+ strcpy(dst, tmp);
+ return (dst);
}
/* const char *
* inet_ntop6(src, dst, size)
- * convert IPv6 binary address into presentation (printable) format
+ * convert IPv6 binary address into presentation (printable) format
* author:
- * Paul Vixie, 1996.
+ * Paul Vixie, 1996.
*/
static const char *
inet_ntop6(const unsigned char *src, char *dst, size_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 = { 0,0 }, cur = { 0,0 };
- unsigned int 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++)
- words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
- best.base = -1;
- cur.base = -1;
- 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 (!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 ((size_t)(tp - tmp) > size) {
- errno = ENOSPC;
- return (NULL);
- }
- strcpy(dst, tmp);
- return (dst);
+ /*
+ * 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 = { 0,0 }, cur = { 0,0 };
+ unsigned int 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++)
+ words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
+ best.base = -1;
+ cur.base = -1;
+ 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 (!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 ((size_t)(tp - tmp) > size)
+ {
+ errno = ENOSPC;
+ return (NULL);
+ }
+ strcpy(dst, tmp);
+ return (dst);
}
-
#endif
+
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