From: Roy Marples <roy@marples.name>
Date: Fri, 29 Jan 2016 11:36:05 +0000 (+0000)
Subject: Allow the suffix of PD addresses to be configurable.
X-Git-Tag: v6.10.2~88
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fda2c66357ac64fa6d3b077084f46dd267beb52e;p=thirdparty%2Fdhcpcd.git

Allow the suffix of PD addresses to be configurable.
Fixes [0666660018].
---

diff --git a/dhcp6.c b/dhcp6.c
index 66781516..88fe4f6f 100644
--- a/dhcp6.c
+++ b/dhcp6.c
@@ -2336,6 +2336,7 @@ dhcp6_ifdelegateaddr(struct interface *ifp, struct ipv6_addr *prefix,
 	char sabuf[INET6_ADDRSTRLEN];
 	const char *sa;
 	int pfxlen;
+	uint64_t vl;
 
 	/* RFC6603 Section 4.2 */
 	if (strcmp(ifp->name, ifs->name) == 0) {
@@ -2354,6 +2355,12 @@ dhcp6_ifdelegateaddr(struct interface *ifp, struct ipv6_addr *prefix,
 	    sla, ia)) == -1)
 		return NULL;
 
+	if (ffs64(sla->suffix) > 128 - pfxlen) {
+		logger(ifp->ctx, LOG_ERR,
+		    "%s: suffix %" PRIu64 " + prefix_len %d > 128",
+		    ifp->name, sla->suffix, pfxlen);
+		return NULL;
+	}
 
 	a = calloc(1, sizeof(*a));
 	if (a == NULL) {
@@ -2371,11 +2378,11 @@ dhcp6_ifdelegateaddr(struct interface *ifp, struct ipv6_addr *prefix,
 	a->prefix = addr;
 	a->prefix_len = (uint8_t)pfxlen;
 
-	/* Wang a 1 at the end as the prefix could be >64
-	 * making SLAAC impossible. */
-	a->addr = a->prefix;
-	a->addr.s6_addr[sizeof(a->addr.s6_addr) - 1] =
-	    (uint8_t)(a->addr.s6_addr[sizeof(a->addr.s6_addr) - 1] + 1);
+	/* Add our suffix */
+	a->addr = addr;
+	vl = be64dec(addr.s6_addr + 8);
+	vl |= sla->suffix;
+	be64enc(a->addr.s6_addr + 8, vl);
 
 	state = D6_STATE(ifp);
 	/* Remove any exiting address */
diff --git a/dhcpcd.conf.5.in b/dhcpcd.conf.5.in
index a7f0acd5..35dd8069 100644
--- a/dhcpcd.conf.5.in
+++ b/dhcpcd.conf.5.in
@@ -22,7 +22,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd October 19, 2015
+.Dd January 29, 2016
 .Dt DHCPCD.CONF 5
 .Os
 .Sh NAME
@@ -252,7 +252,7 @@ Request a DHCPv6 Temporary Address for
 You can request more than one ia_ta by specifying a unique
 .Ar iaid
 for each one.
-.It Ic ia_pd Op Ar iaid Oo / Ar prefix / Ar prefix_len Oc Op Ar interface Op / Ar sla_id Op / Ar prefix_len
+.It Ic ia_pd Op Ar iaid Oo / Ar prefix / Ar prefix_len Oc Op Ar interface Op / Ar sla_id Op / Ar prefix_len Op / Ar suffix
 Request a DHCPv6 Delegated Prefix for
 .Ar iaid .
 This option must be used in an
@@ -273,7 +273,9 @@ Otherwise addresses are only assigned for each
 .Ar interface
 and
 .Ar sla_id .
-Each assigned address will have a suffix of 1.
+Each assigned address will have a
+.Ar suffix ,
+defaulting to 1.
 You cannot assign a prefix to the requesting interface unless the
 DHCPv6 server supports
 .Li RFC6603
diff --git a/if-options.c b/if-options.c
index 9e4ce06d..0ca9f937 100644
--- a/if-options.c
+++ b/if-options.c
@@ -1408,18 +1408,19 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
 			if (strlcpy(sla->ifname, p,
 			    sizeof(sla->ifname)) >= sizeof(sla->ifname))
 			{
-				logger(ctx, LOG_ERR, "%s: interface name too long",
-				    arg);
+				logger(ctx, LOG_ERR,
+				    "%s: interface name too long", arg);
 				goto err_sla;
 			}
+			sla->sla_set = 0;
+			sla->prefix_len = 0;
+			sla->suffix = 1;
 			p = np;
 			if (p) {
 				np = strchr(p, '/');
 				if (np)
 					*np++ = '\0';
-				if (*p == '\0')
-					sla->sla_set = 0;
-				else {
+				if (*p != '\0') {
 					sla->sla = (uint32_t)strtou(p, NULL,
 					    0, 0, UINT32_MAX, &e);
 					sla->sla_set = 1;
@@ -1430,20 +1431,40 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
 						goto err_sla;
 					}
 				}
-				if (np) {
+				p = np;
+			}
+			if (p) {
+				np = strchr(p, '/');
+				if (np)
+					*np++ = '\0';
+				if (*p != '\0') {
 					sla->prefix_len = (uint8_t)strtou(np,
-					    NULL, 0, 0, 120, &e);
+				    NULL, 0, 0, 120, &e);
 					if (e) {
-						logger(ctx, LOG_ERR, "%s: failed to "
+						logger(ctx, LOG_ERR,
+						    "%s: failed to "
 						    "convert prefix len",
 						    ifname);
 						goto err_sla;
 					}
-				} else
-					sla->prefix_len = 0;
-			} else {
-				sla->sla_set = 0;
-				sla->prefix_len = 0;
+				}
+				p = np;
+			}
+			if (p) {
+				np = strchr(p, '/');
+				if (np)
+					*np = '\0';
+				if (*p != '\0') {
+					sla->suffix = (uint64_t)strtou(p, NULL,
+					    0, 0, UINT64_MAX, &e);
+					if (e) {
+						logger(ctx, LOG_ERR,
+						    "%s: failed to "
+						    "convert suffix",
+						    ifname);
+						goto err_sla;
+					}
+				}
 			}
 			/* Sanity check */
 			for (sl = 0; sl < ia->sla_len - 1; sl++) {
diff --git a/if-options.h b/if-options.h
index 66b87d8d..6c7ab153 100644
--- a/if-options.h
+++ b/if-options.h
@@ -129,6 +129,7 @@ struct if_sla {
 	char ifname[IF_NAMESIZE];
 	uint32_t sla;
 	uint8_t prefix_len;
+	uint64_t suffix;
 	int8_t sla_set;
 };