sctp: Add ASCONF operation on the single-homed host

In this case, the SCTP association transmits an ASCONF packet
including addition of the new IP address and deletion of the old
address.  This patch implements this functionality.
In this case, the ASCONF chunk is added to the beginning of the
queue, because the other chunks cannot be transmitted in this state.

Signed-off-by: Michio Honda <micchie@sfc.wide.ad.jp>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Acked-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 27 insertions, 0 deletions

diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 37406039820f..3363d3788259 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -2768,6 +2768,7 @@ struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
 	int			addr_param_len = 0;
 	int 			totallen = 0;
 	int 			i;
+	int			del_pickup = 0;
 
 	/* Get total length of all the address parameters. */
 	addr_buf = addrs;
@@ -2780,6 +2781,13 @@ struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
 		totallen += addr_param_len;
 
 		addr_buf += af->sockaddr_len;
+		if (asoc->asconf_addr_del_pending && !del_pickup) {
+			/* reuse the parameter length from the same scope one */
+			totallen += paramlen;
+			totallen += addr_param_len;
+			del_pickup = 1;
+			SCTP_DEBUG_PRINTK("mkasconf_update_ip: picked same-scope del_pending addr, totallen for all addresses is %d\n", totallen);
+		}
 	}
 
 	/* Create an asconf chunk with the required length. */
@@ -2802,6 +2810,17 @@ struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
 
 		addr_buf += af->sockaddr_len;
 	}
+	if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
+		addr = asoc->asconf_addr_del_pending;
+		af = sctp_get_af_specific(addr->v4.sin_family);
+		addr_param_len = af->to_addr_param(addr, &addr_param);
+		param.param_hdr.type = SCTP_PARAM_DEL_IP;
+		param.param_hdr.length = htons(paramlen + addr_param_len);
+		param.crr_id = i;
+
+		sctp_addto_chunk(retval, paramlen, &param);
+		sctp_addto_chunk(retval, addr_param_len, &addr_param);
+	}
 	return retval;
 }
 
@@ -3224,6 +3243,11 @@ static void sctp_asconf_param_success(struct sctp_association *asoc,
 	case SCTP_PARAM_DEL_IP:
 		local_bh_disable();
 		sctp_del_bind_addr(bp, &addr);
+		if (asoc->asconf_addr_del_pending != NULL &&
+		    sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
+			kfree(asoc->asconf_addr_del_pending);
+			asoc->asconf_addr_del_pending = NULL;
+		}
 		local_bh_enable();
 		list_for_each_entry(transport, &asoc->peer.transport_addr_list,
 				transports) {
@@ -3381,6 +3405,9 @@ int sctp_process_asconf_ack(struct sctp_association *asoc,
 		asconf_len -= length;
 	}
 
+	if (no_err && asoc->src_out_of_asoc_ok)
+		asoc->src_out_of_asoc_ok = 0;
+
 	/* Free the cached last sent asconf chunk. */
 	list_del_init(&asconf->transmitted_list);
 	sctp_chunk_free(asconf);