Userspace Datapath: Add TFTP support.

Both ipv4 and ipv6 are supported. Also, NAT support is included.

Signed-off-by: Darrell Ball <dlu998@gmail.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

2 files changed, 40 insertions, 2 deletions

diff --git a/include/sparse/netinet/in.h b/include/sparse/netinet/in.h
index 8a5b887bd..c28158ca0 100644
--- a/include/sparse/netinet/in.h
+++ b/include/sparse/netinet/in.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2013, 2014, 2015 Nicira, Inc.
+ * Copyright (c) 2011, 2013, 2014, 2015, 2017 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -75,6 +75,7 @@ struct sockaddr_in6 {
 #define IPPROTO_SCTP 132
 
 #define IPPORT_FTP 21
+#define IPPORT_TFTP 69
 
 /* All the IP options documented in Linux ip(7). */
 #define IP_ADD_MEMBERSHIP 35
diff --git a/lib/conntrack.c b/lib/conntrack.c
index 6c593b3ec..1c0e02351 100644
--- a/lib/conntrack.c
+++ b/lib/conntrack.c
@@ -64,6 +64,7 @@ enum ftp_ctl_pkt {
 enum ct_alg_mode {
     CT_FTP_MODE_ACTIVE,
     CT_FTP_MODE_PASSIVE,
+    CT_TFTP_MODE,
 };
 
 static bool conn_key_extract(struct conntrack *, struct dp_packet *,
@@ -142,6 +143,11 @@ handle_ftp_ctl(struct conntrack *ct, const struct conn_lookup_ctx *ctx,
                const struct conn *conn_for_expectation,
                long long now, enum ftp_ctl_pkt ftp_ctl, bool nat);
 
+static void
+handle_tftp_ctl(struct conntrack *ct,
+                const struct conn *conn_for_expectation,
+                long long now);
+
 static struct ct_l4_proto *l4_protos[] = {
     [IPPROTO_TCP] = &ct_proto_tcp,
     [IPPROTO_UDP] = &ct_proto_other,
@@ -384,6 +390,21 @@ is_ftp_ctl(const struct dp_packet *pkt)
 
 }
 
+static bool
+is_tftp_ctl(const struct dp_packet *pkt)
+{
+    uint8_t ip_proto = get_ip_proto(pkt);
+    struct udp_header *uh = dp_packet_l4(pkt);
+
+    /* CT_IPPORT_TFTP is used because IPPORT_TFTP in not defined in OSX,
+     * at least in in.h. Since this value will never change, remove
+     * the external dependency. */
+#define CT_IPPORT_TFTP 69
+    return (ip_proto == IPPROTO_UDP &&
+            uh->udp_dst == htons(CT_IPPORT_TFTP));
+
+}
+
 static void
 alg_exp_init_expiration(struct conntrack *ct,
                         struct alg_exp_node *alg_exp_node,
@@ -1080,8 +1101,9 @@ process_one(struct conntrack *ct, struct dp_packet *pkt,
         set_label(pkt, conn, &setlabel[0], &setlabel[1]);
     }
 
+    bool tftp_ctl = is_tftp_ctl(pkt);
     struct conn conn_for_expectation;
-    if (conn && ftp_ctl) {
+    if (conn && (ftp_ctl || tftp_ctl)) {
         conn_for_expectation = *conn;
     }
 
@@ -1095,6 +1117,8 @@ process_one(struct conntrack *ct, struct dp_packet *pkt,
     if (OVS_UNLIKELY(conn && ftp_ctl)) {
         handle_ftp_ctl(ct, ctx, pkt, &conn_for_expectation,
                        now, CT_FTP_CTL_INTEREST, !!nat_action_info);
+    } else if (OVS_UNLIKELY(conn && tftp_ctl)) {
+        handle_tftp_ctl(ct, &conn_for_expectation, now);
     }
 }
 
@@ -2399,6 +2423,7 @@ expectation_create(struct conntrack *ct,
 
     switch (mode) {
     case CT_FTP_MODE_ACTIVE:
+    case CT_TFTP_MODE:
         src_addr = master_conn->rev_key.src.addr;
         dst_addr = master_conn->rev_key.dst.addr;
         alg_nat_repl_addr = master_conn->key.src.addr;
@@ -2691,6 +2716,7 @@ process_ftp_ctl_v4(struct conntrack *ct,
         *v4_addr_rep = conn_for_expectation->key.dst.addr.ipv4_aligned;
         conn_ipv4_addr = conn_for_expectation->rev_key.src.addr.ipv4_aligned;
         break;
+    case CT_TFTP_MODE:
     default:
         OVS_NOT_REACHED();
     }
@@ -2801,6 +2827,7 @@ process_ftp_ctl_v6(struct conntrack *ct,
     case CT_FTP_MODE_PASSIVE:
         *v6_addr_rep = conn_for_expectation->key.dst.addr;
         break;
+    case CT_TFTP_MODE:
     default:
         OVS_NOT_REACHED();
     }
@@ -2978,3 +3005,13 @@ handle_ftp_ctl(struct conntrack *ct, const struct conn_lookup_ctx *ctx,
         csum_continue(tcp_csum, th, tail - (char *) th - pad));
     return;
 }
+
+static void
+handle_tftp_ctl(struct conntrack *ct,
+                const struct conn *conn_for_expectation,
+                long long now)
+{
+    expectation_create(ct, conn_for_expectation->key.src.port, now,
+                       CT_TFTP_MODE, conn_for_expectation);
+    return;
+}