[Qemu-devel] [PATCH 2/3] slirp: Handle more than 65535 blocks in TFTP transfers

[Herve Poussineau]

From: Herv� Poussineau <address@hidden>

RFC 1350 does not mention block count-roll over. However, a lot of TFTP servers
implement it to be able to transmit big files, so do it also

Signed-off-by: Herv� Poussineau <address@hidden>
---
 slirp/tftp.c |    9 +++++----
 slirp/tftp.h |    1 +
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/slirp/tftp.c b/slirp/tftp.c
index 7ef44c9..7e63269 100644
--- a/slirp/tftp.c
+++ b/slirp/tftp.c
@@ -92,7 +92,7 @@ static int tftp_session_find(Slirp *slirp, struct tftp_t *tp)
   return -1;
 }
 
-static int tftp_read_data(struct tftp_session *spt, uint16_t block_nr,
+static int tftp_read_data(struct tftp_session *spt, uint32_t block_nr,
                           uint8_t *buf, int len)
 {
   int fd;
@@ -196,7 +196,7 @@ out:
 }
 
 static int tftp_send_data(struct tftp_session *spt,
-                          uint16_t block_nr,
+                          uint32_t block_nr,
                          struct tftp_t *recv_tp)
 {
   struct sockaddr_in saddr, daddr;
@@ -221,7 +221,7 @@ static int tftp_send_data(struct tftp_session *spt,
   m->m_data += sizeof(struct udpiphdr);
 
   tp->tp_op = htons(TFTP_DATA);
-  tp->x.tp_data.tp_block_nr = htons(block_nr);
+  tp->x.tp_data.tp_block_nr = htons(block_nr & 0xffff);
 
   saddr.sin_addr = recv_tp->ip.ip_dst;
   saddr.sin_port = recv_tp->udp.uh_dport;
@@ -253,6 +253,7 @@ static int tftp_send_data(struct tftp_session *spt,
     tftp_session_terminate(spt);
   }
 
+  spt->block_nr = block_nr;
   return 0;
 }
 
@@ -407,7 +408,7 @@ static void tftp_handle_ack(Slirp *slirp, struct tftp_t 
*tp, int pktlen)
   }
 
   if (tftp_send_data(&slirp->tftp_sessions[s],
-                    ntohs(tp->x.tp_data.tp_block_nr) + 1,
+                    slirp->tftp_sessions[s].block_nr + 1,
                     tp) < 0) {
     return;
   }
diff --git a/slirp/tftp.h b/slirp/tftp.h
index 72e5e91..471f22e 100644
--- a/slirp/tftp.h
+++ b/slirp/tftp.h
@@ -36,6 +36,7 @@ struct tftp_session {
 
     struct in_addr client_ip;
     uint16_t client_port;
+    uint32_t block_nr;
 
     int timestamp;
 };
-- 
1.6.0.2.GIT