dhcpv6: improve code readibility

Use struct dhcpv6_client_header hdr to access fixed DHCPv6 header fields

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

diff --git a/src/dhcpv6.c b/src/dhcpv6.c
index 58b3bd764fd9d89aea7a40d0104b954a2705d3b9..e88c0076c3d9e8a75c8b3532f2c58ad3ccb918df 100644 (file)
--- a/src/dhcpv6.c
+++ b/src/dhcpv6.c
@@ -348,19 +348,20 @@ static void handle_client_request(void *addr, void *data, size_t len,
        if (hdr->msg_type == DHCPV6_MSG_RELAY_FORW)
                handle_nested_message(data, len, &opts, &opts_end, iov);
 
-       memcpy(dest.tr_id, &opts[-3], sizeof(dest.tr_id));
+       memcpy(dest.tr_id, hdr->transaction_id, sizeof(dest.tr_id));
 
-       if (opts[-4] == DHCPV6_MSG_ADVERTISE || opts[-4] == DHCPV6_MSG_REPLY || opts[-4] == DHCPV6_MSG_RELAY_REPL)
+       if (hdr->msg_type == DHCPV6_MSG_ADVERTISE || hdr->msg_type == DHCPV6_MSG_REPLY ||
+           hdr->msg_type == DHCPV6_MSG_RELAY_REPL)
                return;
 
        if (!IN6_IS_ADDR_MULTICAST((struct in6_addr *)dest_addr) && iov[IOV_NESTED].iov_len == 0 &&
-               (opts[-4] == DHCPV6_MSG_SOLICIT || opts[-4] == DHCPV6_MSG_CONFIRM ||
-                opts[-4] == DHCPV6_MSG_REBIND || opts[-4] == DHCPV6_MSG_INFORMATION_REQUEST))
+               (hdr->msg_type == DHCPV6_MSG_SOLICIT || hdr->msg_type == DHCPV6_MSG_CONFIRM ||
+                hdr->msg_type == DHCPV6_MSG_REBIND || hdr->msg_type == DHCPV6_MSG_INFORMATION_REQUEST))
                return;
 
-       if (opts[-4] == DHCPV6_MSG_SOLICIT) {
+       if (hdr->msg_type == DHCPV6_MSG_SOLICIT) {
                dest.msg_type = DHCPV6_MSG_ADVERTISE;
-       } else if (opts[-4] == DHCPV6_MSG_INFORMATION_REQUEST) {
+       } else if (hdr->msg_type == DHCPV6_MSG_INFORMATION_REQUEST) {
                iov[IOV_REFRESH].iov_base = &refresh;
                iov[IOV_REFRESH].iov_len = sizeof(refresh);
 
@@ -407,8 +408,8 @@ static void handle_client_request(void *addr, void *data, size_t len,
        }
 
        if (!IN6_IS_ADDR_MULTICAST((struct in6_addr *)dest_addr) && iov[IOV_NESTED].iov_len == 0 &&
-               (opts[-4] == DHCPV6_MSG_REQUEST || opts[-4] == DHCPV6_MSG_RENEW ||
-                opts[-4] == DHCPV6_MSG_RELEASE || opts[-4] == DHCPV6_MSG_DECLINE)) {
+           (hdr->msg_type == DHCPV6_MSG_REQUEST || hdr->msg_type == DHCPV6_MSG_RENEW ||
+            hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE)) {
                iov[IOV_STAT].iov_base = &stat;
                iov[IOV_STAT].iov_len = sizeof(stat);
 
@@ -419,10 +420,12 @@ static void handle_client_request(void *addr, void *data, size_t len,
                return;
        }
 
-       if (opts[-4] != DHCPV6_MSG_INFORMATION_REQUEST) {
-               ssize_t ialen = dhcpv6_handle_ia(pdbuf, sizeof(pdbuf), iface, addr, &opts[-4], opts_end);
+       if (hdr->msg_type != DHCPV6_MSG_INFORMATION_REQUEST) {
+               ssize_t ialen = dhcpv6_handle_ia(pdbuf, sizeof(pdbuf), iface, addr, data, opts_end);
+
                iov[IOV_PDBUF].iov_len = ialen;
-               if (ialen < 0 || (ialen == 0 && (opts[-4] == DHCPV6_MSG_REBIND || opts[-4] == DHCPV6_MSG_CONFIRM)))
+               if (ialen < 0 ||
+                   (ialen == 0 && (hdr->msg_type == DHCPV6_MSG_REBIND || hdr->msg_type == DHCPV6_MSG_CONFIRM)))
                        return;
        }