When reporting the server as not responding, if the hostname was
authorBruce Momjian <bruce@momjian.us>
Wed, 24 Nov 2010 22:04:19 +0000 (17:04 -0500)
committerBruce Momjian <bruce@momjian.us>
Wed, 24 Nov 2010 22:04:19 +0000 (17:04 -0500)
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.

doc/src/sgml/libpq.sgml
src/backend/utils/adt/Makefile
src/backend/utils/adt/inet_cidr_ntop.c [moved from src/backend/utils/adt/inet_net_ntop.c with 55% similarity]
src/include/port.h
src/include/utils/builtins.h
src/interfaces/libpq/fe-connect.c
src/port/Makefile
src/port/getaddrinfo.c
src/port/inet_net_ntop.c [new file with mode: 0644]

index 5cc81bbe2690bd4bb6a4e22fb1099c5daf3981f5..c95fc4fd64d75ab54599bb8722c56537971585f1 100644 (file)
@@ -170,11 +170,11 @@ PGconn *PQconnectdbParams(const char **keywords, const char **values, int expand
            If <literal>host</> is specified without <literal>hostaddr</>,
            a host name lookup occurs.
            If <literal>hostaddr</> is specified without <literal>host</>,
-           the value for <literal>hostaddr</> gives the server address.
+           the value for <literal>hostaddr</> gives the server network address.
            The connection attempt will fail in any of the cases where a
            host name is required.
            If both <literal>host</> and <literal>hostaddr</> are specified,
-           the value for <literal>hostaddr</> gives the server address.
+           the value for <literal>hostaddr</> gives the server network address.
            The value for <literal>host</> is ignored unless needed for
            authentication or verification purposes, in which case it will be
            used as the host name.  Note that authentication is likely to fail
index be272b51d97260a02e444bd48b55b60503e99c45..ce28abd9fe1e5d725c52a236c507f5fd731552d3 100644 (file)
@@ -23,7 +23,7 @@ OBJS = acl.o arrayfuncs.o array_userfuncs.o arrayutils.o bool.o \
        oid.o oracle_compat.o pseudotypes.o rowtypes.o \
        regexp.o regproc.o ruleutils.o selfuncs.o \
        tid.o timestamp.o varbit.o varchar.o varlena.o version.o xid.o \
-       network.o mac.o inet_net_ntop.o inet_net_pton.o \
+       network.o mac.o inet_cidr_ntop.o inet_net_pton.o \
        ri_triggers.o pg_lzcompress.o pg_locale.o formatting.o \
        ascii.o quote.o pgstatfuncs.o encode.o dbsize.o genfile.o trigfuncs.o \
        tsginidx.o tsgistidx.o tsquery.o tsquery_cleanup.o tsquery_gist.o \
similarity index 55%
rename from src/backend/utils/adt/inet_net_ntop.c
rename to src/backend/utils/adt/inet_cidr_ntop.c
index 3d7fb658897afa67fed226f43cf22e480a72fbd4..5f2a3d361d945b7bb7a2ad524e7edec706c010a2 100644 (file)
@@ -32,21 +32,14 @@ static const char rcsid[] = "Id: inet_net_ntop.c,v 1.1.2.2 2004/03/09 09:17:27 m
 #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_cidr_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);
 static char *inet_cidr_ntop_ipv6(const u_char *src, int bits,
                                        char *dst, size_t size);
 
@@ -300,231 +293,3 @@ emsgsize:
        errno = EMSGSIZE;
        return (NULL);
 }
-
-
-/*
- * 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);
-}
index 204876888aca605fea395af71f9f99d113fbc37e..0cfbed83d45ef0f17cf00750ea8e36d9db26b566 100644 (file)
@@ -437,4 +437,8 @@ extern void qsort_arg(void *base, size_t nel, size_t elsize,
 /* port/chklocale.c */
 extern int     pg_get_encoding_from_locale(const char *ctype);
 
+/* port/inet_net_ntop.c */
+extern char *inet_net_ntop(int af, const void *src, int bits,
+                         char *dst, size_t size);
+
 #endif   /* PG_PORT_H */
index bad0a8ebdf26e59a02f5b824e8d31bfdb7f0100c..a2fb7494cb4cb28ec9fc21fc34762ec989778151 100644 (file)
@@ -795,9 +795,7 @@ extern Datum chr (PG_FUNCTION_ARGS);
 extern Datum repeat(PG_FUNCTION_ARGS);
 extern Datum ascii(PG_FUNCTION_ARGS);
 
-/* inet_net_ntop.c */
-extern char *inet_net_ntop(int af, const void *src, int bits,
-                         char *dst, size_t size);
+/* inet_cidr_ntop.c */
 extern char *inet_cidr_ntop(int af, const void *src, int bits,
                           char *dst, size_t size);
 
index 8f318a1a8cc5bf2d49b2605dd76581609cf9be32..8011604e5cd1ad92cd2e0cca5f1980a813a318cd 100644 (file)
@@ -960,9 +960,28 @@ connectFailureMessage(PGconn *conn, int errorno)
        else
 #endif   /* HAVE_UNIX_SOCKETS */
        {
+               char    host_addr[NI_MAXHOST];
+               bool    display_host_addr;
+               struct sockaddr_in *host_addr_struct = (struct sockaddr_in *)
+                                                                                               &conn->raddr.addr;
+
+               /*
+                *      Optionally display the network address with the hostname.
+                *      This is useful to distinguish between IPv4 and IPv6 connections.
+                */
+               if (conn->pghostaddr != NULL)
+                       strlcpy(host_addr, conn->pghostaddr, NI_MAXHOST);
+               else if (inet_net_ntop(conn->addr_cur->ai_family, &host_addr_struct->sin_addr,
+                                host_addr_struct->sin_family == AF_INET ? 32 : 128,
+                                host_addr, sizeof(host_addr)) == NULL)
+                       strcpy(host_addr, "???");
+
+               display_host_addr = !conn->pghostaddr &&
+                                                       strcmp(conn->pghost, host_addr) != 0;
+               
                appendPQExpBuffer(&conn->errorMessage,
                                                  libpq_gettext("could not connect to server: %s\n"
-                                        "\tIs the server running on host \"%s\" and accepting\n"
+                                        "\tIs the server running on host \"%s\" %s%s%sand accepting\n"
                                                                                "\tTCP/IP connections on port %s?\n"),
                                                  SOCK_STRERROR(errorno, sebuf, sizeof(sebuf)),
                                                  conn->pghostaddr
@@ -970,6 +989,10 @@ connectFailureMessage(PGconn *conn, int errorno)
                                                  : (conn->pghost
                                                         ? conn->pghost
                                                         : "???"),
+                                                 /* display the IP address only if not already output */
+                                                 display_host_addr ? "(" : "",
+                                                 display_host_addr ? host_addr : "",
+                                                 display_host_addr ? ") " : "",
                                                  conn->pgport);
        }
 }
index 327ec7246c296ae80d75e538c28ec44ce611ec8e..711f63308925e9f036afc1b25035816dad4bd93c 100644 (file)
@@ -30,7 +30,7 @@ include $(top_builddir)/src/Makefile.global
 override CPPFLAGS := -I$(top_builddir)/src/port -DFRONTEND $(CPPFLAGS)
 LIBS += $(PTHREAD_LIBS)
 
-OBJS = $(LIBOBJS) chklocale.o dirmod.o exec.o noblock.o path.o \
+OBJS = $(LIBOBJS) chklocale.o dirmod.o exec.o inet_net_ntop.o noblock.o path.o \
        pgsleep.o pgstrcasecmp.o qsort.o qsort_arg.o sprompt.o thread.o
 ifneq (,$(filter $(PORTNAME),cygwin win32))
 OBJS += pipe.o
index f867744eee27c087a1b8ad3ac676e61739c1b78a..807f5bd56d7e7e05136f22e2960ec5a5706176cf 100644 (file)
@@ -388,16 +388,14 @@ getnameinfo(const struct sockaddr * sa, int salen,
 
        if (node)
        {
-               int                     ret = -1;
-
                if (sa->sa_family == AF_INET)
                {
-                       char       *p;
-
-                       p = inet_ntoa(((struct sockaddr_in *) sa)->sin_addr);
-                       ret = snprintf(node, nodelen, "%s", p);
+                       if (inet_net_ntop(AF_INET, ((struct sockaddr_in *) sa)->sin_addr,
+                               sa->sa_family == AF_INET ? 32 : 128,
+                               node, nodelen) == NULL)
+                       return EAI_MEMORY;
                }
-               if (ret == -1 || ret > nodelen)
+               else
                        return EAI_MEMORY;
        }
 
diff --git a/src/port/inet_net_ntop.c b/src/port/inet_net_ntop.c
new file mode 100644 (file)
index 0000000..02d3a7c
--- /dev/null
@@ -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);
+}
+