When reporting the server as not responding, if the hostname was

supplied, also print the IP address.  This allows IPv4 and IPv6 failures
to be distinguished.  Also useful when a hostname resolves to multiple
IP addresses.

Also, remove use of inet_ntoa() and use our own inet_net_ntop() in all
places, including in libpq, because it is thread-safe.

1 files changed, 275 insertions, 0 deletions

diff --git a/src/port/inet_net_ntop.c b/src/port/inet_net_ntop.c
new file mode 100644
index 00000000000..02d3a7cea55
--- /dev/null
+++ b/src/port/inet_net_ntop.c
@@ -0,0 +1,275 @@
+/*
+ * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (c) 1996,1999 by Internet Software Consortium.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+ * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ *	  src/backend/utils/adt/inet_net_ntop.c
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static const char rcsid[] = "Id: inet_net_ntop.c,v 1.1.2.2 2004/03/09 09:17:27 marka Exp $";
+#endif
+
+#include "postgres.h"
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include "utils/inet.h"
+
+
+#define NS_IN6ADDRSZ 16
+#define NS_INT16SZ 2
+
+#ifdef SPRINTF_CHAR
+#define SPRINTF(x) strlen(sprintf/**/x)
+#else
+#define SPRINTF(x) ((size_t)sprintf x)
+#endif
+
+static char *inet_net_ntop_ipv4(const u_char *src, int bits,
+				   char *dst, size_t size);
+static char *inet_net_ntop_ipv6(const u_char *src, int bits,
+				   char *dst, size_t size);
+
+
+/*
+ * char *
+ * inet_net_ntop(af, src, bits, dst, size)
+ *	convert host/network address from network to presentation format.
+ *	"src"'s size is determined from its "af".
+ * return:
+ *	pointer to dst, or NULL if an error occurred (check errno).
+ * note:
+ *	192.5.5.1/28 has a nonzero host part, which means it isn't a network
+ *	as called for by inet_net_pton() but it can be a host address with
+ *	an included netmask.
+ * author:
+ *	Paul Vixie (ISC), October 1998
+ */
+char *
+inet_net_ntop(int af, const void *src, int bits, char *dst, size_t size)
+{
+	switch (af)
+	{
+		case PGSQL_AF_INET:
+			return (inet_net_ntop_ipv4(src, bits, dst, size));
+		case PGSQL_AF_INET6:
+			return (inet_net_ntop_ipv6(src, bits, dst, size));
+		default:
+			errno = EAFNOSUPPORT;
+			return (NULL);
+	}
+}
+
+/*
+ * static char *
+ * inet_net_ntop_ipv4(src, bits, dst, size)
+ *	convert IPv4 network address from network to presentation format.
+ *	"src"'s size is determined from its "af".
+ * return:
+ *	pointer to dst, or NULL if an error occurred (check errno).
+ * note:
+ *	network byte order assumed.  this means 192.5.5.240/28 has
+ *	0b11110000 in its fourth octet.
+ * author:
+ *	Paul Vixie (ISC), October 1998
+ */
+static char *
+inet_net_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size)
+{
+	char	   *odst = dst;
+	char	   *t;
+	int			len = 4;
+	int			b;
+
+	if (bits < 0 || bits > 32)
+	{
+		errno = EINVAL;
+		return (NULL);
+	}
+
+	/* Always format all four octets, regardless of mask length. */
+	for (b = len; b > 0; b--)
+	{
+		if (size <= sizeof ".255")
+			goto emsgsize;
+		t = dst;
+		if (dst != odst)
+			*dst++ = '.';
+		dst += SPRINTF((dst, "%u", *src++));
+		size -= (size_t) (dst - t);
+	}
+
+	/* don't print masklen if 32 bits */
+	if (bits != 32)
+	{
+		if (size <= sizeof "/32")
+			goto emsgsize;
+		dst += SPRINTF((dst, "/%u", bits));
+	}
+
+	return (odst);
+
+emsgsize:
+	errno = EMSGSIZE;
+	return (NULL);
+}
+
+static int
+decoct(const u_char *src, int bytes, char *dst, size_t size)
+{
+	char	   *odst = dst;
+	char	   *t;
+	int			b;
+
+	for (b = 1; b <= bytes; b++)
+	{
+		if (size <= sizeof "255.")
+			return (0);
+		t = dst;
+		dst += SPRINTF((dst, "%u", *src++));
+		if (b != bytes)
+		{
+			*dst++ = '.';
+			*dst = '\0';
+		}
+		size -= (size_t) (dst - t);
+	}
+	return (dst - odst);
+}
+
+static char *
+inet_net_ntop_ipv6(const u_char *src, int bits, 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:255.255.255.255/128"];
+	char	   *tp;
+	struct
+	{
+		int			base,
+					len;
+	}			best, cur;
+	u_int		words[NS_IN6ADDRSZ / NS_INT16SZ];
+	int			i;
+
+	if ((bits < -1) || (bits > 128))
+	{
+		errno = EINVAL;
+		return (NULL);
+	}
+
+	/*
+	 * 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;
+	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 == 7 && words[7] != 0x0001) ||
+									  (best.len == 5 && words[5] == 0xffff)))
+		{
+			int			n;
+
+			n = decoct(src + 12, 4, tp, sizeof tmp - (tp - tmp));
+			if (n == 0)
+			{
+				errno = EMSGSIZE;
+				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';
+
+	if (bits != -1 && bits != 128)
+		tp += SPRINTF((tp, "/%u", bits));
+
+	/*
+	 * Check for overflow, copy, and we're done.
+	 */
+	if ((size_t) (tp - tmp) > size)
+	{
+		errno = EMSGSIZE;
+		return (NULL);
+	}
+	strcpy(dst, tmp);
+	return (dst);
+}
+