udhcpc: remove workaround for bugs in Win98 dhcp server ("MSFT 98" vendor string)

Stats for last three commits:

function                                             old     new   delta
udhcpc_main                                         2635    2646     +11
udhcp_recv_raw_packet                                425     414     -11
udhcp_recv_kernel_packet                             210     134     -76
packed_usage                                       28940   28857     -83
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/3 up/down: 11/-170)          Total: -159 bytes
   text    data     bss     dec     hex filename
 879524     493    7584  887601   d8b31 busybox_old
 879340     493    7584  887417   d8a79 busybox_unstripped

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

1 files changed, 3 insertions, 31 deletions

diff --git a/networking/udhcp/packet.c b/networking/udhcp/packet.c
index 4d5ff0676..bd754f766 100644
--- a/networking/udhcp/packet.c
+++ b/networking/udhcp/packet.c
@@ -81,7 +81,6 @@ void FAST_FUNC udhcp_dump_packet(struct dhcp_packet *packet)
 int FAST_FUNC udhcp_recv_kernel_packet(struct dhcp_packet *packet, int fd)
 {
 	int bytes;
-	unsigned char *vendor;
 
 	memset(packet, 0, sizeof(*packet));
 	bytes = safe_read(fd, packet, sizeof(*packet));
@@ -90,42 +89,15 @@ int FAST_FUNC udhcp_recv_kernel_packet(struct dhcp_packet *packet, int fd)
 		return bytes; /* returns -1 */
 	}
 
-	if (packet->cookie != htonl(DHCP_MAGIC)) {
+	if (bytes < offsetof(struct dhcp_packet, options)
+	 || packet->cookie != htonl(DHCP_MAGIC)
+	) {
 		bb_info_msg("Packet with bad magic, ignoring");
 		return -2;
 	}
 	log1("Received a packet");
 	udhcp_dump_packet(packet);
 
-	if (packet->op == BOOTREQUEST) {
-		vendor = udhcp_get_option(packet, DHCP_VENDOR);
-		if (vendor) {
-#if 0
-			static const char broken_vendors[][8] = {
-				"MSFT 98",
-				""
-			};
-			int i;
-			for (i = 0; broken_vendors[i][0]; i++) {
-				if (vendor[OPT_LEN - OPT_DATA] == (uint8_t)strlen(broken_vendors[i])
-				 && strncmp((char*)vendor, broken_vendors[i], vendor[OPT_LEN - OPT_DATA]) == 0
-				) {
-					log1("Broken client (%s), forcing broadcast replies",
-						broken_vendors[i]);
-					packet->flags |= htons(BROADCAST_FLAG);
-				}
-			}
-#else
-			if (vendor[OPT_LEN - OPT_DATA] == (uint8_t)(sizeof("MSFT 98")-1)
-			 && memcmp(vendor, "MSFT 98", sizeof("MSFT 98")-1) == 0
-			) {
-				log1("Broken client (%s), forcing broadcast replies", "MSFT 98");
-				packet->flags |= htons(BROADCAST_FLAG);
-			}
-#endif
-		}
-	}
-
 	return bytes;
 }