From: Roy Marples <roy@marples.name>
Date: Tue, 30 Aug 2022 09:48:11 +0000 (+0100)
Subject: inet6: Support Tokenised IPv6 Identifiers
X-Git-Tag: v10.0.0~45
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1a70f1b51c453c66993fab8172e57924059bd34b;p=thirdparty%2Fdhcpcd.git

inet6: Support Tokenised IPv6 Identifiers

https://datatracker.ietf.org/doc/id/draft-chown-6man-tokenised-ipv6-identifiers-02.txt
Didn't quite make it to a RFC, but it's easy to implement and seems
a nice to have.

Fixes #101.
---

diff --git a/src/dhcpcd.conf.5.in b/src/dhcpcd.conf.5.in
index f00df3e1..742f39f2 100644
--- a/src/dhcpcd.conf.5.in
+++ b/src/dhcpcd.conf.5.in
@@ -24,7 +24,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd August 29, 2022
+.Dd August 30, 2022
 .Dt DHCPCD.CONF 5
 .Os
 .Sh NAME
@@ -648,13 +648,16 @@ instead of the default
 .It Ic ssid Ar ssid
 Subsequent options are only parsed for this wireless
 .Ar ssid .
-.It Ic slaac Ar hwaddr | Ar private Op Ar temp | Ar temporary
+.It Ic slaac Ic hwaddr | Ic private | Ic token Ar token Op Ic temp | Ic temporary
 Selects the interface identifier used for SLAAC generated IPv6 addresses.
 If
-.Ar private
+.Ic private
 is used, a RFC 7217 address is generated.
+If
+.Ic token Ar token
+is used then the token is combied with the prefix to make the final address.
 The
-.Ar temporary
+.Ic temporary
 directive will create a temporary address for the prefix as well.
 .It Ic static Ar value
 Configures a static
diff --git a/src/if-options.c b/src/if-options.c
index 46ea7ea0..fe490fbb 100644
--- a/src/if-options.c
+++ b/src/if-options.c
@@ -2231,6 +2231,22 @@ invalid_token:
 			ifo->options |= DHCPCD_SLAACPRIVATE;
 		else
 			ifo->options &= ~DHCPCD_SLAACPRIVATE;
+		if (strcmp(arg, "token") == 0) {
+			if (np == NULL) {
+				logerrx("slaac token: no token specified");
+				return -1;
+			}
+			arg = np;
+			np = strwhite(np);
+			if (np != NULL) {
+				*np++ = '\0';
+				np = strskipwhite(np);
+			}
+			if (inet_pton(AF_INET6, arg, &ifo->token) != 1) {
+				logerrx("slaac token: invalid token");
+				return -1;
+			}
+		}
 		if (np != NULL &&
 		    (strcmp(np, "temp") == 0 || strcmp(np, "temporary") == 0))
 			ifo->options |= DHCPCD_SLAACTEMP;
diff --git a/src/if-options.h b/src/if-options.h
index f80119d6..4b252826 100644
--- a/src/if-options.h
+++ b/src/if-options.h
@@ -266,6 +266,9 @@ struct if_options {
 
 	struct if_ia *ia;
 	size_t ia_len;
+#ifdef INET6
+	struct in6_addr token;
+#endif
 
 	struct dhcp_opt *dhcp_override;
 	size_t dhcp_override_len;
diff --git a/src/ipv6.c b/src/ipv6.c
index 04bf7746..d8e00de3 100644
--- a/src/ipv6.c
+++ b/src/ipv6.c
@@ -359,51 +359,6 @@ again:
 }
 #endif
 
-int
-ipv6_makeaddr(struct in6_addr *addr, struct interface *ifp,
-    const struct in6_addr *prefix, int prefix_len, unsigned int flags)
-{
-	const struct ipv6_addr *ap;
-	int dad;
-
-	if (prefix_len < 0 || prefix_len > 120) {
-		errno = EINVAL;
-		return -1;
-	}
-
-#ifdef IPV6_AF_TEMPORARY
-	if (flags & IPV6_AF_TEMPORARY)
-		return ipv6_maketemporaryaddress(addr, prefix, prefix_len, ifp);
-#else
-	UNUSED(flags);
-#endif
-
-	if (ifp->options->options & DHCPCD_SLAACPRIVATE) {
-		dad = 0;
-		if (ipv6_makestableprivate(addr,
-		    prefix, prefix_len, ifp, &dad) == -1)
-			return -1;
-		return dad;
-	}
-
-	if (prefix_len > 64) {
-		errno = EINVAL;
-		return -1;
-	}
-	if ((ap = ipv6_linklocal(ifp)) == NULL) {
-		/* We delay a few functions until we get a local-link address
-		 * so this should never be hit. */
-		errno = ENOENT;
-		return -1;
-	}
-
-	/* Make the address from the first local-link address */
-	memcpy(addr, prefix, sizeof(*prefix));
-	addr->s6_addr32[2] = ap->addr.s6_addr32[2];
-	addr->s6_addr32[3] = ap->addr.s6_addr32[3];
-	return 0;
-}
-
 static int
 ipv6_makeprefix(struct in6_addr *prefix, const struct in6_addr *addr, int len)
 {
@@ -478,6 +433,55 @@ ipv6_prefixlen(const struct in6_addr *mask)
 	return (uint8_t)(x * NBBY + y);
 }
 
+int
+ipv6_makeaddr(struct in6_addr *addr, struct interface *ifp,
+    const struct in6_addr *prefix, int prefix_len, unsigned int flags)
+{
+	const struct ipv6_addr *ap;
+	const struct if_options *ifo = ifp->options;
+	int dad;
+
+	if (prefix_len < 0 || prefix_len > 120) {
+		errno = EINVAL;
+		return -1;
+	}
+
+#ifdef IPV6_AF_TEMPORARY
+	if (flags & IPV6_AF_TEMPORARY)
+		return ipv6_maketemporaryaddress(addr, prefix, prefix_len, ifp);
+#else
+	UNUSED(flags);
+#endif
+
+	if (ifo->options & DHCPCD_SLAACPRIVATE) {
+		dad = 0;
+		if (ipv6_makestableprivate(addr,
+		    prefix, prefix_len, ifp, &dad) == -1)
+			return -1;
+		return dad;
+	} else if (!IN6_IS_ADDR_UNSPECIFIED(&ifo->token)) {
+		*addr = ifo->token;
+		return ipv6_makeprefix(addr, prefix, prefix_len);
+	}
+
+	if (prefix_len > 64) {
+		errno = EINVAL;
+		return -1;
+	}
+	if ((ap = ipv6_linklocal(ifp)) == NULL) {
+		/* We delay a few functions until we get a local-link address
+		 * so this should never be hit. */
+		errno = ENOENT;
+		return -1;
+	}
+
+	/* Make the address from the first local-link address */
+	memcpy(addr, prefix, sizeof(*prefix));
+	addr->s6_addr32[2] = ap->addr.s6_addr32[2];
+	addr->s6_addr32[3] = ap->addr.s6_addr32[3];
+	return 0;
+}
+
 static void
 in6_to_h64(uint64_t *vhigh, uint64_t *vlow, const struct in6_addr *addr)
 {