1 files changed, 42 insertions, 7 deletions

diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c
index 66750e2e6..2904119e5 100644
--- a/networking/udhcp/dhcpd.c
+++ b/networking/udhcp/dhcpd.c
@@ -649,7 +649,8 @@ static void init_packet(struct dhcp_packet *packet, struct dhcp_packet *oldpacke
         packet->flags = oldpacket->flags;
         packet->gateway_nip = oldpacket->gateway_nip;
         packet->ciaddr = oldpacket->ciaddr;
-        udhcp_add_simple_option(packet, DHCP_SERVER_ID, server_data.server_nip);
+        IF_FEATURE_UDHCPD_BOOTP(if (type != MSGTYPE_BOOTP))
+                udhcp_add_simple_option(packet, DHCP_SERVER_ID, server_data.server_nip);
 }
 
 /* Fill options field, siaddr_nip, and sname and boot_file fields.
@@ -725,7 +726,12 @@ static uint32_t select_lease_time(struct dhcp_packet *packet)
 
 /* We got a DHCP DISCOVER. Send an OFFER. */
 /* NOINLINE: limit stack usage in caller */
-static NOINLINE void send_offer(struct dhcp_packet *oldpacket,
+#if !ENABLE_FEATURE_UDHCPD_BOOTP
+#define send_offer(is_dhcp_client, ...) \
+        send_offer(__VA_ARGS__)
+#endif
+static NOINLINE void send_offer(void *is_dhcp_client,
+                struct dhcp_packet *oldpacket,
                 uint32_t static_lease_nip,
                 struct dyn_lease *lease,
                 uint32_t requested_nip,
@@ -734,7 +740,12 @@ static NOINLINE void send_offer(struct dhcp_packet *oldpacket,
         struct dhcp_packet packet;
         uint32_t lease_time_sec;
 
+#if ENABLE_FEATURE_UDHCPD_BOOTP
+        init_packet(&packet, oldpacket, is_dhcp_client ? DHCPOFFER : MSGTYPE_BOOTP);
+#else
+        enum { is_dhcp_client = 1 };
         init_packet(&packet, oldpacket, DHCPOFFER);
+#endif
 
         /* If it is a static lease, use its IP */
         packet.yiaddr = static_lease_nip;
@@ -784,9 +795,16 @@ static NOINLINE void send_offer(struct dhcp_packet *oldpacket,
                 }
         }
 
-        lease_time_sec = select_lease_time(oldpacket);
-        udhcp_add_simple_option(&packet, DHCP_LEASE_TIME, htonl(lease_time_sec));
+        if (is_dhcp_client) {
+                lease_time_sec = select_lease_time(oldpacket);
+                udhcp_add_simple_option(&packet, DHCP_LEASE_TIME, htonl(lease_time_sec));
+        }
+/* TODO: pass "is_dhcp_client" to add_server_options(), avoid adding confusing options to BOOTP clients? */
         add_server_options(&packet);
+        if (!is_dhcp_client && udhcp_end_option(packet.options) >= RFC1048_OPTIONS_BUFSIZE) {
+                bb_simple_error_msg("BOOTP reply too large, not sending");
+                return;
+        }
 
         /* send_packet emits error message itself if it detects failure */
         send_packet_verbose(&packet, "sending OFFER to %s");
@@ -1050,8 +1068,12 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
                         continue;
                 }
                 msg_type = udhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
-                if (!msg_type || msg_type[0] < DHCP_MINTYPE || msg_type[0] > DHCP_MAXTYPE) {
-                        bb_info_msg("no or bad message type option%s", ", ignoring packet");
+                if (
+                        IF_FEATURE_UDHCPD_BOOTP( msg_type && )
+                        IF_NOT_FEATURE_UDHCPD_BOOTP( !msg_type || )
+                        (msg_type[0] < DHCP_MINTYPE || msg_type[0] > DHCP_MAXTYPE)
+                ) {
+                        bb_info_msg("bad message type option%s", ", ignoring packet");
                         continue;
                 }
 
@@ -1086,12 +1108,25 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
                         move_from_unaligned32(requested_nip, requested_ip_opt);
                 }
 
+#if ENABLE_FEATURE_UDHCPD_BOOTP
+                /* Handle old BOOTP clients */
+                if (!msg_type) {
+                        log1("received %s", "BOOTP BOOTREQUEST");
+                        if (!static_lease_nip) {
+                                bb_info_msg("no static lease for BOOTP client%s", ", ignoring packet");
+                                continue;
+                        }
+                        send_offer(msg_type, &packet, static_lease_nip, lease, requested_nip, arpping_ms);
+                        continue;
+                }
+#endif
+
                 switch (msg_type[0]) {
 
                 case DHCPDISCOVER:
                         log1("received %s", "DISCOVER");
 
-                        send_offer(&packet, static_lease_nip, lease, requested_nip, arpping_ms);
+                        send_offer(msg_type, &packet, static_lease_nip, lease, requested_nip, arpping_ms);
                         break;
 
                 case DHCPREQUEST: