From: Roy Marples <roy@marples.name>
Date: Wed, 4 Sep 2019 03:30:55 +0000 (+0300)
Subject: Solaris: getifaddrs(3) lacks subnet address, so hack into dstaddr
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d2a00886afe373d437f41ed34c045bbcdaab5155;p=thirdparty%2Fdhcpcd.git

Solaris: getifaddrs(3) lacks subnet address, so hack into dstaddr

TOTAL HACK ALERT!
Abuse dstaddr due to lack of subnetaddr in struct ifaddrs.

Also, get the subnet address when learning and from route messages
if the INET6 address is unspecified.
---

diff --git a/src/if-sun.c b/src/if-sun.c
index 9fbaf070..63b2c11c 100644
--- a/src/if-sun.c
+++ b/src/if-sun.c
@@ -383,6 +383,18 @@ if_ifa_lo0(void)
 	return ifa;
 }
 
+static int
+if_getsubnet(int fd, const char *ifname, void *subnet, size_t subnet_len)
+{
+	struct lifreq		lifr = { .lifr_addrlen = 0 };
+
+	strlcpy(lifr.lifr_name, ifname, sizeof(lifr.lifr_name));
+	if (ioctl(fd, SIOCGLIFSUBNET, &lifr) == -1)
+		return -1;
+	memcpy(subnet, &lifr.lifr_addr, MIN(subnet_len,sizeof(lifr.lifr_addr)));
+	return 0;
+}
+
 /* getifaddrs(3) does not support AF_LINK, strips aliases and won't
  * report addresses that are not UP.
  * As such it's just totally useless, so we need to roll our own. */
@@ -391,6 +403,10 @@ if_getifaddrs(struct ifaddrs **ifap)
 {
 	struct linkwalk		lw;
 	struct ifaddrs		*ifa;
+#ifdef INET6
+	struct sockaddr_in6	*sin6;
+	int			fd;
+#endif
 
 	/* Private libc function which we should not have to call
 	 * to get non UP addresses. */
@@ -414,6 +430,30 @@ if_getifaddrs(struct ifaddrs **ifap)
 	ifa->ifa_next = lw.lw_ifa;
 
 	*ifap = ifa;
+
+#ifdef INET6
+	/* Walk the tree and fetch subnet */
+	fd = socket(PF_INET6, SOCK_DGRAM, 0);
+	if (fd == -1)
+		return 0;
+	for (; ifa != NULL; ifa = ifa->ifa_next) {
+		if (ifa->ifa_addr->sa_family != AF_INET6)
+			continue;
+
+		sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
+		if (!IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
+			continue;
+
+		/* Total hack */
+		ifa->ifa_dstaddr = malloc(sizeof(struct sockaddr_storage));
+		if (ifa->ifa_dstaddr == NULL)
+			continue;
+		if_getsubnet(fd, ifa->ifa_name,
+		    ifa->ifa_dstaddr, sizeof(struct sockaddr_storage));
+	}
+	close(fd);
+#endif
+
 	return 0;
 }
 
@@ -984,6 +1024,7 @@ if_ifa(struct dhcpcd_ctx *ctx, const struct ifa_msghdr *ifam)
 	{
 		struct in6_addr			addr6, mask6;
 		const struct sockaddr_in6	*sin6;
+		struct sockaddr_in6		subnet;
 
 		sin6 = (const void *)rti_info[RTAX_IFA];
 		addr6 = sin6->sin6_addr;
@@ -1005,6 +1046,19 @@ if_ifa(struct dhcpcd_ctx *ctx, const struct ifa_msghdr *ifam)
 		} else if (flags == -1)
 			return 0;
 
+		if (IN6_IS_ADDR_UNSPECIFIED(&addr6)) {
+			int fd, r;
+
+			fd = socket(PF_INET6, SOCK_DGRAM, 0);
+			if (fd == -1)
+				return -1;
+			r = if_getsubnet(fd, ifalias, &subnet, sizeof(subnet));
+			close(fd);
+			if (r == -1)
+				return -1;
+			addr6 = subnet.sin6_addr;
+		}
+
 		ipv6_handleifa(ctx,
 		    ifam->ifam_type == RTM_CHGADDR ?
 		    RTM_NEWADDR : ifam->ifam_type,
diff --git a/src/if.c b/src/if.c
index 56d06056..5aedbd00 100644
--- a/src/if.c
+++ b/src/if.c
@@ -241,6 +241,11 @@ if_learnaddrs(struct dhcpcd_ctx *ctx, struct if_head *ifs,
 		case AF_INET6:
 			sin6 = (void *)ifa->ifa_addr;
 			net6 = (void *)ifa->ifa_netmask;
+#ifdef __sun
+			/* Total hack. See if-sun.c */
+			if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
+				sin6 = (void *)ifa->ifa_dstaddr;
+#endif
 #ifdef __KAME__
 			if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
 				/* Remove the scope from the address */