From b76b27cad5ade1d483d4b94df6b35976bccf1055 Mon Sep 17 00:00:00 2001 From: Allan Stephens Date: Thu, 27 Oct 2011 16:31:26 -0400 Subject: [PATCH] tipc: Prevent loss of fragmented messages over unicast links Modifies unicast link endpoint logic so an incoming fragmented message is not lost if reassembly cannot begin because there is no buffer big enough to hold the entire reassembled message. The link endpoint now ignores the first fragment completely, which causes the sending node to retransmit the first fragment so that reassembly can be re-attempted. Previously, the sender would have had no reason to retransmit the 1st fragment, so we would never have a chance to re-try the allocation. Signed-off-by: Allan Stephens --- net/tipc/link.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/net/tipc/link.c b/net/tipc/link.c index cce953723ddb..d8b0a22367b6 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -1774,6 +1774,7 @@ protocol_check: head = link_insert_deferred_queue(l_ptr, head); if (likely(msg_is_dest(msg, tipc_own_addr))) { + int ret; deliver: if (likely(msg_isdata(msg))) { tipc_node_unlock(n_ptr); @@ -1798,11 +1799,15 @@ deliver: continue; case MSG_FRAGMENTER: l_ptr->stats.recv_fragments++; - if (tipc_link_recv_fragment(&l_ptr->defragm_buf, - &buf, &msg)) { + ret = tipc_link_recv_fragment( + &l_ptr->defragm_buf, + &buf, &msg); + if (ret == 1) { l_ptr->stats.recv_fragmented++; goto deliver; } + if (ret == -1) + l_ptr->next_in_no--; break; case CHANGEOVER_PROTOCOL: type = msg_type(msg); @@ -2632,7 +2637,9 @@ int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb, set_fragm_size(pbuf, fragm_sz); set_expected_frags(pbuf, exp_fragm_cnt - 1); } else { - warn("Link unable to reassemble fragmented message\n"); + dbg("Link unable to reassemble fragmented message\n"); + buf_discard(fbuf); + return -1; } buf_discard(fbuf); return 0; -- 2.30.2