Ensure that NMRP packets are at least 64 bytes

diff --git a/nmrp.c b/nmrp.c
index e45b07eb7c9a02be8a1dcee93598aa9f131c8e2c..8cf82d6ed560b9da1812ce21b5d941fd6eecf30c 100644 (file)
--- a/nmrp.c
+++ b/nmrp.c
@@ -39,6 +39,10 @@
 #define IP_LEN 4
 #define MAX_LOOP_RECV 1024
 
+#ifndef MAX
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#endif
+
 #ifndef PACKED
 #define PACKED __attribute__((__packed__))
 #endif
@@ -88,6 +92,7 @@ struct nmrp_msg {
        uint16_t len;
        /* only opts[0] is valid! think of this as a char* */
        struct nmrp_opt opts[NMRP_MAX_OPT_NUM];
+       uint8_t padding[8];
        /* this is NOT part of the transmitted packet */
        uint32_t num_opts;
 } PACKED;
@@ -289,7 +294,7 @@ static uint8_t *ethsock_get_hwaddr_fake(struct ethsock* sock)
 static int pkt_send(struct ethsock *sock, struct nmrp_pkt *pkt)
 {
        size_t len = ntohs(pkt->msg.len) + sizeof(pkt->eh);
-       return ethsock_send(sock, pkt, len);
+       return ethsock_send(sock, pkt, MAX(len, 64));
 }
 
 static int pkt_recv(struct ethsock *sock, struct nmrp_pkt *pkt)