From: Job Snijders <job@fastly.com>
To: libc-alpha@sourceware.org
Subject: Re: [PATCH] resolv: add IPv6 support to inet_net_pton()
Date: Sun, 17 Mar 2024 03:19:28 +0000 [thread overview]
Message-ID: <ZfZhQAXYzRYd1eep@feather.sobornost.net> (raw)
In-Reply-To: <ZfZF-I-_z3jay5cN@feather.sobornost.net>
Dear all,
Slight tweaks compared to what I sent out earlier today:
* for consistency use the __set_errno macro to set errno
* preserve errno unless setting it explicitly (avoid errno stomping)
Original message:
On Sun, Mar 17, 2024 at 01:23:04AM +0000, Job Snijders wrote:
> This is a refresh of a diff I proposed back in December 2022 to add IPv6
> support to inet_net_pton().
>
> The starting point of this changeset was OpenBSD's
> libc/net/inet_net_pton.c (r1.13) implementation of inet_net_pton_ipv6().
> https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/lib/libc/net/inet_net_pton.c?annotate=1.13
>
> The OpenBSD implementation was adapted to glibc as following:
>
> 1) Use strtol() instead of strtonum()
> 2) Updated comments
>
> I've tested the changeset on Debian Bookworm.
>
> Your feedback is appreciated!
Kind regards,
Job
Signed-off: Job Snijders <job@fastly.com>
---
resolv/inet_net_pton.c | 80 +++++++++++++++++++++++++++++++++++++++---
1 file changed, 76 insertions(+), 4 deletions(-)
diff --git a/resolv/inet_net_pton.c b/resolv/inet_net_pton.c
index 63a47b7394..217e18263c 100644
--- a/resolv/inet_net_pton.c
+++ b/resolv/inet_net_pton.c
@@ -1,4 +1,6 @@
/*
+ * Copyright (c) 2024 Job Snijders <job@fastly.com>
+ * Copyright (c) 2012 by Gilles Chehade <gilles@openbsd.org>
* Copyright (c) 1996,1999 by Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
@@ -35,13 +37,16 @@
static int inet_net_pton_ipv4 (const char *src, u_char *dst,
size_t size) __THROW;
+static int inet_net_pton_ipv6 (const char *src, u_char *dst,
+ size_t size) __THROW;
/*
- * static int
+ * int
* inet_net_pton(af, src, dst, size)
- * convert network number from presentation to network format.
- * accepts hex octets, hex strings, decimal octets, and /CIDR.
- * "size" is in bytes and describes "dst".
+ * Convert network number from presentation format to network format.
+ * If "af" is set to AF_INET, accept various formats like hex octets,
+ * hex strings, or decimal octets. If "af" is set to AF_INET6, accept
+ * IPv6 addresses. "size" is in bytes and describes "dst".
* return:
* number of bits, either imputed classfully or specified with /CIDR,
* or -1 if some failure occurred (check errno). ENOENT means it was
@@ -55,6 +60,8 @@ inet_net_pton (int af, const char *src, void *dst, size_t size)
switch (af) {
case AF_INET:
return (inet_net_pton_ipv4(src, dst, size));
+ case AF_INET6:
+ return (inet_net_pton_ipv6(src, dst, size));
default:
__set_errno (EAFNOSUPPORT);
return (-1);
@@ -196,3 +203,68 @@ inet_net_pton_ipv4 (const char *src, u_char *dst, size_t size)
__set_errno (EMSGSIZE);
return (-1);
}
+
+
+/*
+ * Convert an IPv6 prefix from presentation format to network format.
+ * Return the number of bits specified, or -1 as error (check errno).
+ */
+static int
+inet_net_pton_ipv6 (const char *src, u_char *dst, size_t size)
+{
+ struct in6_addr in6;
+ int bits, save_errno;
+ long lbits;
+ size_t bytes;
+ char buf[INET6_ADDRSTRLEN + sizeof("/128")];
+ char *ep, *sep;
+
+ save_errno = errno;
+
+ if (strlcpy(buf, src, sizeof(buf)) >= sizeof(buf)) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+
+ sep = strchr(buf, '/');
+ if (sep != NULL)
+ *sep++ = '\0';
+
+ if (inet_pton(AF_INET6, buf, &in6) != 1) {
+ __set_errno (ENOENT);
+ return (-1);
+ }
+
+ if (sep == NULL) {
+ bits = 128;
+ goto out;
+ }
+
+ if (sep[0] == '\0' || !isascii(sep[0]) || !isdigit(sep[0])) {
+ __set_errno (ENOENT);
+ return (-1);
+ }
+
+ __set_errno (0);
+ lbits = strtol(sep, &ep, 10);
+ if (sep[0] == '\0' || *ep != '\0') {
+ __set_errno (ENOENT);
+ return (-1);
+ }
+ if ((errno == ERANGE && (lbits == LONG_MAX || lbits == LONG_MIN))
+ || (lbits > 128 || lbits < 0)) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ bits = lbits;
+
+ out:
+ bytes = (bits + 7) / 8;
+ if (bytes > size) {
+ __set_errno (EMSGSIZE);
+ return (-1);
+ }
+ __set_errno (save_errno);
+ memcpy(dst, &in6.s6_addr, bytes);
+ return (bits);
+}
--
2.43.0
next prev parent reply other threads:[~2024-03-17 3:19 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-22 17:54 Job Snijders
2022-12-22 18:21 ` Florian Weimer
2022-12-22 18:28 ` copying a string with truncation (was: [PATCH] resolv: add IPv6 support to inet_net_pton()) Alejandro Colomar
2022-12-22 20:25 ` Alejandro Colomar
2022-12-23 6:55 ` Sam James
2022-12-23 7:00 ` Sam James
2022-12-23 11:42 ` Alejandro Colomar
2022-12-23 11:45 ` Alejandro Colomar
2022-12-31 15:11 ` Sam James
2023-01-17 10:56 ` [PATCH] resolv: add IPv6 support to inet_net_pton() Job Snijders
2023-04-19 11:31 ` Job Snijders
2024-03-17 1:23 ` Job Snijders
2024-03-17 3:19 ` Job Snijders [this message]
2024-03-17 11:18 ` Florian Weimer
2024-03-18 8:59 ` Job Snijders
2024-03-18 9:23 ` Andreas Schwab
2024-03-18 23:01 ` Job Snijders
2024-03-19 8:20 ` Andreas Schwab
2024-03-19 8:29 ` Job Snijders
2024-03-19 9:50 ` Andreas Schwab
2024-03-22 4:16 ` Job Snijders
2024-03-22 14:24 ` Zack Weinberg
2024-03-25 9:04 ` Job Snijders
2024-04-14 14:56 ` Job Snijders
2024-04-15 8:15 ` Xi Ruoyao
2024-03-25 8:45 ` Andreas Schwab
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