From: Denys Vlasenko <vda.linux@googlemail.com>
Date: Sat, 13 Apr 2019 17:43:15 +0000 (+0200)
Subject: udhcpc6: add a few comments, no code changes.
X-Git-Tag: 1_31_0~110
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=0d75e8b7973353f1d034b97bebfd4d2c13a9f5d6;p=oweals%2Fbusybox.git

udhcpc6: add a few comments, no code changes.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---

diff --git a/networking/udhcp/d6_dhcpc.c b/networking/udhcp/d6_dhcpc.c
index 97985642b..112f12df2 100644
--- a/networking/udhcp/d6_dhcpc.c
+++ b/networking/udhcp/d6_dhcpc.c
@@ -531,6 +531,7 @@ static uint8_t *add_d6_client_options(uint8_t *ptr)
 
 static int d6_mcast_from_client_config_ifindex(struct d6_packet *packet, uint8_t *end)
 {
+	/* FF02::1:2 is "All_DHCP_Relay_Agents_and_Servers" address */
 	static const uint8_t FF02__1_2[16] = {
 		0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 		0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02,
diff --git a/networking/udhcp/d6_socket.c b/networking/udhcp/d6_socket.c
index 6ad53a9c2..fe46e5f1d 100644
--- a/networking/udhcp/d6_socket.c
+++ b/networking/udhcp/d6_socket.c
@@ -38,6 +38,15 @@ int FAST_FUNC d6_read_interface(const char *interface, int *ifindex, struct in6_
 			log1("IP %s", inet_ntoa(((struct sockaddr_in *)ifa->ifa_addr)->sin_addr));
 		}
 #endif
+/* RFC 3315
+ * 16. Client Source Address and Interface Selection
+ *
+ * "When a client sends a DHCP message to the
+ * All_DHCP_Relay_Agents_and_Servers address, ... ... The client
+ * MUST use a link-local address assigned to the interface for which it
+ * is requesting configuration information as the source address in the
+ * header of the IP datagram."
+ */
 		if (ifa->ifa_addr->sa_family == AF_INET6
 		 && IN6_IS_ADDR_LINKLOCAL(&sip6->sin6_addr)
 		) {