From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Yongjun Subject: Re: [PATCH net-next-2.6 v3 2/3] sctp: Add ASCONF operation on the single-homed host Date: Mon, 11 Apr 2011 13:41:38 +0800 Message-ID: <4DA29492.7020300@cn.fujitsu.com> References: <02627A77-8793-4EEC-9540-F2DECBB8E23A@sfc.wide.ad.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, lksctp-developers@lists.sourceforge.net To: Michio Honda Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:63174 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752099Ab1DKFlY (ORCPT ); Mon, 11 Apr 2011 01:41:24 -0400 In-Reply-To: <02627A77-8793-4EEC-9540-F2DECBB8E23A@sfc.wide.ad.jp> Sender: netdev-owner@vger.kernel.org List-ID: comment inline. > SCTP can change the IP address 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. > > Signed-off-by: Michio Honda > --- > diff --git a/include/net/sctp/constants.h b/include/net/sctp/constants.h > index c70d8cc..d7a4ee3 100644 > --- a/include/net/sctp/constants.h > +++ b/include/net/sctp/constants.h > @@ -441,4 +441,8 @@ enum { > */ > #define SCTP_AUTH_RANDOM_LENGTH 32 > > +/* ASCONF PARAMETERS */ > +#define SCTP_ASCONF_V4_PARAM_LEN 16 > +#define SCTP_ASCONF_V6_PARAM_LEN 28 > + > #endif /* __sctp_constants_h__ */ > diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h > index 9352d12..498a3cf 100644 > --- a/include/net/sctp/sm.h > +++ b/include/net/sctp/sm.h > @@ -259,6 +259,7 @@ struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, > struct sctp_chunk *asconf); > int sctp_process_asconf_ack(struct sctp_association *asoc, > struct sctp_chunk *asconf_ack); > +void sctp_path_check_and_react(struct sctp_association *, struct sockaddr *); > struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, > __u32 new_cum_tsn, size_t nstreams, > struct sctp_fwdtsn_skip *skiplist); > diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h > index cc9185c..400ee8a 100644 > --- a/include/net/sctp/structs.h > +++ b/include/net/sctp/structs.h > @@ -1901,6 +1901,9 @@ struct sctp_association { > * after reaching 4294967295. > */ > __u32 addip_serial; > + union sctp_addr *asconf_addr_del_pending; > + __u32 asconf_del_pending_cid; > + int src_out_of_asoc_ok; > > /* SCTP AUTH: list of the endpoint shared keys. These > * keys are provided out of band by the user applicaton > diff --git a/net/sctp/associola.c b/net/sctp/associola.c > index 6b04287..2dfd0e8 100644 > --- a/net/sctp/associola.c > +++ b/net/sctp/associola.c > @@ -279,6 +279,9 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a > asoc->peer.asconf_capable = 0; > if (sctp_addip_noauth) > asoc->peer.asconf_capable = 1; > + asoc->asconf_addr_del_pending = NULL; > + asoc->asconf_del_pending_cid = 0; > + asoc->src_out_of_asoc_ok = 0; > > /* Create an input queue. */ > sctp_inq_init(&asoc->base.inqueue); > @@ -443,6 +446,10 @@ void sctp_association_free(struct sctp_association *asoc) > > asoc->peer.transport_count = 0; > > + /* Free pending address space being deleted */ > + if (asoc->asconf_addr_del_pending != NULL) > + kfree(asoc->asconf_addr_del_pending); > + > /* Free any cached ASCONF_ACK chunk. */ > sctp_assoc_free_asconf_acks(asoc); > > @@ -1277,7 +1284,7 @@ void sctp_assoc_update(struct sctp_association *asoc, > */ > void sctp_assoc_update_retran_path(struct sctp_association *asoc) > { > - struct sctp_transport *t, *next; > + struct sctp_transport *t, *next, *unconfirmed; > struct list_head *head = &asoc->peer.transport_addr_list; > struct list_head *pos; > > @@ -1287,7 +1294,7 @@ void sctp_assoc_update_retran_path(struct sctp_association *asoc) > /* Find the next transport in a round-robin fashion. */ > t = asoc->peer.retran_path; > pos = &t->transports; > - next = NULL; > + next = unconfirmed = NULL; > > while (1) { > /* Skip the head. */ > @@ -1318,11 +1325,15 @@ void sctp_assoc_update_retran_path(struct sctp_association *asoc) > */ > if (t->state != SCTP_UNCONFIRMED && !next) > next = t; > + else if (t->state == SCTP_UNCONFIRMED) > + unconfirmed = t; > } > } > > if (t) > asoc->peer.retran_path = t; > + else if (unconfirmed) > + asoc->peer.retran_path = t = unconfirmed; > > SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association" > " %p addr: ", > diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c > index 865ce7b..56c97ce 100644 > --- a/net/sctp/ipv6.c > +++ b/net/sctp/ipv6.c > @@ -332,6 +332,13 @@ static void sctp_v6_get_saddr(struct sctp_sock *sk, > matchlen = bmatchlen; > } > } > + if (laddr->state == SCTP_ADDR_NEW && asoc->src_out_of_asoc_ok) { > + bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a); > + if (!baddr || (matchlen < bmatchlen)) { > + baddr = &laddr->a; > + matchlen = bmatchlen; > + } > + } > } > > if (baddr) { > diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c > index 26dc005..033ea20 100644 > --- a/net/sctp/outqueue.c > +++ b/net/sctp/outqueue.c > @@ -344,7 +344,14 @@ int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk) > break; > } > } else { > - list_add_tail(&chunk->list, &q->control_chunk_list); > + /* We add the ASCONF for the only one newly added address at > + * the front of the queue > + */ > + if (q->asoc->src_out_of_asoc_ok && \ > + chunk->chunk_hdr->type == SCTP_CID_ASCONF) > + list_add(&chunk->list, &q->control_chunk_list); > + else > + list_add_tail(&chunk->list, &q->control_chunk_list); > SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); > } > > @@ -850,6 +857,24 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) > case SCTP_CID_SHUTDOWN: > case SCTP_CID_ECN_ECNE: > case SCTP_CID_ASCONF: > + /* RFC 5061, 5.3 > + * F1) This means that until such time as the ASCONF > + * containing the add is acknowledged, the sender MUST > + * NOT use the new IP address as a source for ANY SCTP > + * packet except on carrying an ASCONF Chunk. > + */ > + if (asoc->src_out_of_asoc_ok) { > + SCTP_DEBUG_PRINTK("outq_flush: out_of_asoc_ok, transmit chunk type %d\n", > + chunk->chunk_hdr->type); > + packet = &transport->packet; > + sctp_packet_config(packet, vtag, > + asoc->peer.ecn_capable); > + sctp_packet_append_chunk(packet, chunk); > + error = sctp_packet_transmit(packet); > + if (error < 0) > + return error; > + goto sctp_flush_out; > + } > case SCTP_CID_FWD_TSN: > status = sctp_packet_transmit_chunk(packet, chunk, > one_packet); > diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c > index 152976e..b8ec3cc 100644 > --- a/net/sctp/protocol.c > +++ b/net/sctp/protocol.c > @@ -510,7 +510,8 @@ static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc, > sctp_v4_dst_saddr(&dst_saddr, dst, htons(bp->port)); > rcu_read_lock(); > list_for_each_entry_rcu(laddr, &bp->address_list, list) { > - if (!laddr->valid || (laddr->state != SCTP_ADDR_SRC)) > + if (!laddr->valid || (laddr->state != SCTP_ADDR_SRC && > + asoc->src_out_of_asoc_ok == 0)) > continue; > if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a)) > goto out_unlock; > diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c > index de98665..5a085b3 100644 > --- a/net/sctp/sm_make_chunk.c > +++ b/net/sctp/sm_make_chunk.c > @@ -2651,6 +2651,61 @@ __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) > return retval; > } > > +void > +sctp_path_check_and_react(struct sctp_association *asoc, struct sockaddr *sa) > +{ > + struct sctp_transport *trans; > + int addrnum, family; > + struct sctp_sockaddr_entry *saddr; > + struct sctp_bind_addr *bp; > + union sctp_addr *tmpaddr; > + > + family = sa->sa_family; > + bp = &asoc->base.bind_addr; > + addrnum = 0; > + /* count up the number of local addresses in the same family */ > + list_for_each_entry(saddr, &bp->address_list, list) { > + if (saddr->a.sa.sa_family == family) { > + tmpaddr = &saddr->a; > + if (family == AF_INET6 && > + ipv6_addr_type(&tmpaddr->v6.sin6_addr) & > + IPV6_ADDR_LINKLOCAL) { > + continue; > + } > + addrnum++; > + } > + } > + if (addrnum == 1) { > + union sctp_addr *tmpaddr; > + tmpaddr = (union sctp_addr *)sa; > + SCTP_DEBUG_PRINTK_IPADDR("pcheck_react: only 1 local addr in asoc %p ", > + " family %d\n", asoc, tmpaddr, family); > + list_for_each_entry(trans, &asoc->peer.transport_addr_list, > + transports) { > + /* reset path information and release refcount to the > + * dst_entry based on the src change */ > + sctp_transport_hold(trans); > + trans->cwnd = min(4*asoc->pathmtu, > + max_t(__u32, 2*asoc->pathmtu, 4380)); > + trans->ssthresh = asoc->peer.i.a_rwnd; > + trans->rtt = 0; > + trans->srtt = 0; > + trans->rttvar = 0; > + trans->rto = asoc->rto_initial; > + dst_release(trans->dst); > + trans->dst = NULL; > + memset(&trans->saddr, 0, sizeof(union sctp_addr)); > + sctp_transport_route(trans, NULL, > + sctp_sk(asoc->base.sk)); > + SCTP_DEBUG_PRINTK_IPADDR("we freed dst_entry (asoc: %p dst: ", > + " trans: %p)\n", asoc, (&trans->ipaddr), trans); > + trans->rto_pending = 1; > + sctp_transport_put(trans); > + } > + } > + return; > +} > + > /* > * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) > * 0 1 2 3 > @@ -2744,11 +2799,29 @@ struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, > int addr_param_len = 0; > int totallen = 0; > int i; > + sctp_addip_param_t del_param; /* 8 Bytes (Type 0xC002, Len and CrrID) */ > + sctp_addip_param_t spr_param; > + struct sctp_af *del_af; > + struct sctp_af *spr_af; > + int del_addr_param_len = 0; > + int spr_addr_param_len = 0; > + int del_paramlen = sizeof(sctp_addip_param_t); > + int spr_paramlen = sizeof(sctp_addip_param_t); > + union sctp_addr_param del_addr_param; /* (v4) 8 Bytes, (v6) 20 Bytes */ > + union sctp_addr_param spr_addr_param; > + int v4 = 0; > + int v6 = 0; > > /* Get total length of all the address parameters. */ > addr_buf = addrs; > for (i = 0; i < addrcnt; i++) { > addr = (union sctp_addr *)addr_buf; > + if (addr != NULL) { > + if (addr->sa.sa_family == AF_INET) > + v4 = 1; > + else if (addr->sa.sa_family == AF_INET6) > + v6 = 1; > + } > af = sctp_get_af_specific(addr->v4.sin_family); > addr_param_len = af->to_addr_param(addr, &addr_param); > > @@ -2757,6 +2830,40 @@ struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, > > addr_buf += af->sockaddr_len; > } > + /* Add the length of a pending address being deleted */ > + if (flags == SCTP_PARAM_ADD_IP && asoc->asconf_addr_del_pending) { > + if ((asoc->asconf_addr_del_pending->sa.sa_family == AF_INET > + && v4) || > + (asoc->asconf_addr_del_pending->sa.sa_family == AF_INET6 > + && v6)) { > + del_af = sctp_get_af_specific( > + asoc->asconf_addr_del_pending->sa.sa_family); > + del_addr_param_len = del_af->to_addr_param( > + asoc->asconf_addr_del_pending, &del_addr_param); > + totallen += del_paramlen; > + totallen += del_addr_param_len; > + SCTP_DEBUG_PRINTK("mkasconf_update_ip: now we picked del_pending addr, totallen for all addresses is %d\n", > + totallen); > + /* for Set Primary (equal size as del parameters */ > + totallen += del_paramlen; > + totallen += del_addr_param_len; > + } > + if (v4) { > + if (totallen != SCTP_ASCONF_V4_PARAM_LEN * 2 && > + totallen != SCTP_ASCONF_V4_PARAM_LEN * 3) { > + SCTP_DEBUG_PRINTK("mkasconf_update_ip: incorrect total length of ASCONF parameters, del + add MUST be 32 bytes, but %d bytes\n", totallen); > + return NULL; > + } > + } else if (v6) { > + if (totallen != SCTP_ASCONF_V6_PARAM_LEN * 2 && > + totallen != SCTP_ASCONF_V6_PARAM_LEN * 3) { > + SCTP_DEBUG_PRINTK("mkasconf_update_ip: incorrect total length of ASCONF parameters, del + add MUST be 56 bytes, but %d bytes\n", totallen); > + return NULL; > + } > + } We really need this length check? we accept both v4 and v6 address if allowed. > + } > + SCTP_DEBUG_PRINTK("mkasconf_update_ip: call mkasconf() for %d bytes\n", > + totallen); > > /* Create an asconf chunk with the required length. */ > retval = sctp_make_asconf(asoc, laddr, totallen); > @@ -2778,6 +2885,32 @@ struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, > > addr_buf += af->sockaddr_len; > } > + if (flags == SCTP_PARAM_ADD_IP && asoc->asconf_addr_del_pending) { > + addr = asoc->asconf_addr_del_pending; > + del_af = sctp_get_af_specific(addr->v4.sin_family); > + del_addr_param_len = del_af->to_addr_param(addr, > + &del_addr_param); > + del_param.param_hdr.type = SCTP_PARAM_DEL_IP; > + del_param.param_hdr.length = htons(del_paramlen + > + del_addr_param_len); > + del_param.crr_id = i; > + asoc->asconf_del_pending_cid = i; > + > + sctp_addto_chunk(retval, del_paramlen, &del_param); > + sctp_addto_chunk(retval, del_addr_param_len, &del_addr_param); > + /* For SET_PRIMARY */ SET_PRIMARY is unnecessary, since we have only one address. > + addr_buf = addrs; > + addr = (union sctp_addr *)addr_buf; > + spr_af = sctp_get_af_specific(addr->v4.sin_family); > + spr_addr_param_len = spr_af->to_addr_param(addr, > + &spr_addr_param); > + spr_param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; > + spr_param.param_hdr.length = htons(spr_paramlen + > + spr_addr_param_len); > + spr_param.crr_id = (i+1); > + sctp_addto_chunk(retval, spr_paramlen, &spr_param); > + sctp_addto_chunk(retval, spr_addr_param_len, &spr_addr_param); > + } > return retval; > } > > @@ -2990,7 +3123,7 @@ static __be16 sctp_process_asconf_param(struct sctp_association *asoc, > * an Error Cause TLV set to the new error code 'Request to > * Delete Source IP Address' > */ > - if (sctp_cmp_addr_exact(sctp_source(asconf), &addr)) > + if (sctp_cmp_addr_exact(&asconf->source, &addr)) > return SCTP_ERROR_DEL_SRC_IP; > > /* Section 4.2.2 > @@ -3193,16 +3326,37 @@ static void sctp_asconf_param_success(struct sctp_association *asoc, > local_bh_enable(); > list_for_each_entry(transport, &asoc->peer.transport_addr_list, > transports) { > - if (transport->state == SCTP_ACTIVE) > + if (transport->state == SCTP_ACTIVE && > + !asoc->src_out_of_asoc_ok) > continue; > dst_release(transport->dst); > sctp_transport_route(transport, NULL, > sctp_sk(asoc->base.sk)); > } > + asoc->src_out_of_asoc_ok = 0; > break; > case SCTP_PARAM_DEL_IP: > local_bh_disable(); > sctp_del_bind_addr(bp, &addr); > + if (asoc->asconf_addr_del_pending != NULL) { > + if ((addr.sa.sa_family == AF_INET) && > + (asoc->asconf_addr_del_pending->sa.sa_family == > + AF_INET)) { > + if (asoc->asconf_addr_del_pending->v4.sin_addr.s_addr == addr.v4.sin_addr.s_addr) { > + kfree(asoc->asconf_addr_del_pending); > + asoc->asconf_del_pending_cid = 0; > + asoc->asconf_addr_del_pending = NULL; > + } > + } else if ((addr.sa.sa_family == AF_INET6) && > + (asoc->asconf_addr_del_pending->sa.sa_family == > + AF_INET6)) { > + if (ipv6_addr_equal(&asoc->asconf_addr_del_pending->v6.sin6_addr, &addr.v6.sin6_addr)) { > + kfree(asoc->asconf_addr_del_pending); > + asoc->asconf_del_pending_cid = 0; > + asoc->asconf_addr_del_pending = NULL; > + } > + } > + } > local_bh_enable(); > list_for_each_entry(transport, &asoc->peer.transport_addr_list, > transports) { > @@ -3293,6 +3447,8 @@ int sctp_process_asconf_ack(struct sctp_association *asoc, > int no_err = 1; > int retval = 0; > __be16 err_code = SCTP_ERROR_NO_ERROR; > + sctp_addip_param_t *first_asconf_param = NULL; > + int first_asconf_paramlen; > > /* Skip the chunkhdr and addiphdr from the last asconf sent and store > * a pointer to address parameter. > @@ -3307,6 +3463,8 @@ int sctp_process_asconf_ack(struct sctp_association *asoc, > length = ntohs(addr_param->v4.param_hdr.length); > asconf_param = (sctp_addip_param_t *)((void *)addr_param + length); > asconf_len -= length; > + first_asconf_param = asconf_param; > + first_asconf_paramlen = ntohs(first_asconf_param->param_hdr.length); > > /* ADDIP 4.1 > * A8) If there is no response(s) to specific TLV parameter(s), and no > @@ -3361,6 +3519,35 @@ int sctp_process_asconf_ack(struct sctp_association *asoc, > asconf_len -= length; > } > > + /* When the source address obviously changes to newly added one, we > + reset the cwnd to re-probe the path condition > + */ > + if (no_err && first_asconf_param->param_hdr.type == SCTP_PARAM_ADD_IP) { > + if (first_asconf_paramlen == SCTP_ASCONF_V4_PARAM_LEN) { > + struct sockaddr_in sin; > + > + memset(&sin, 0, sizeof(struct sockaddr_in)); > + sin.sin_family = AF_INET; > + memcpy(&sin.sin_addr.s_addr, first_asconf_param + 1, > + sizeof(struct in_addr)); > + sctp_path_check_and_react(asoc, > + (struct sockaddr *)&sin); > + > + } else if (first_asconf_paramlen == SCTP_ASCONF_V6_PARAM_LEN) { > + struct sockaddr_in6 sin6; > + > + memset(&sin6, 0, sizeof(struct sockaddr_in6)); > + sin6.sin6_family = AF_INET6; > + memcpy(&sin6.sin6_addr, first_asconf_param + 1, > + sizeof(struct in6_addr)); > + sctp_path_check_and_react(asoc, > + (struct sockaddr *)&sin6); > + } else { > + SCTP_DEBUG_PRINTK("funny asconf_paramlen? (%d)\n", > + first_asconf_paramlen); > + } > + } > + > /* Free the cached last sent asconf chunk. */ > list_del_init(&asconf->transmitted_list); > sctp_chunk_free(asconf); > diff --git a/net/sctp/socket.c b/net/sctp/socket.c > index 3951a10..2bfe2a9 100644 > --- a/net/sctp/socket.c > +++ b/net/sctp/socket.c > @@ -527,6 +527,7 @@ static int sctp_send_asconf_add_ip(struct sock *sk, > struct list_head *p; > int i; > int retval = 0; > + struct sctp_transport *trans = NULL; > > if (!sctp_addip_enable) > return retval; > @@ -583,13 +584,10 @@ static int sctp_send_asconf_add_ip(struct sock *sk, > goto out; > } > > - retval = sctp_send_asconf(asoc, chunk); > - if (retval) > - goto out; > - > /* Add the new addresses to the bind address list with > * use_as_src set to 0. > */ > + SCTP_DEBUG_PRINTK("snd_asconf_addip: next, add_bind_addr with ADDR_NEW flag\n"); > addr_buf = addrs; > for (i = 0; i < addrcnt; i++) { > addr = (union sctp_addr *)addr_buf; > @@ -599,6 +597,28 @@ static int sctp_send_asconf_add_ip(struct sock *sk, > SCTP_ADDR_NEW, GFP_ATOMIC); > addr_buf += af->sockaddr_len; > } > + list_for_each_entry(trans, &asoc->peer.transport_addr_list, > + transports) { > + if (asoc->asconf_addr_del_pending != NULL) > + /* This ADDIP ASCONF piggybacks DELIP for the > + * last address, so need to select src addr > + * from the out_of_asoc addrs > + */ > + asoc->src_out_of_asoc_ok = 1; > + /* Clear the source and route cache in the path */ > + memset(&trans->saddr, 0, sizeof(union sctp_addr)); > + dst_release(trans->dst); > + trans->cwnd = min(4*asoc->pathmtu, max_t(__u32, > + 2*asoc->pathmtu, 4380)); > + trans->ssthresh = asoc->peer.i.a_rwnd; > + trans->rto = asoc->rto_initial; > + trans->rtt = 0; > + trans->srtt = 0; > + trans->rttvar = 0; > + sctp_transport_route(trans, NULL, > + sctp_sk(asoc->base.sk)); > + } > + retval = sctp_send_asconf(asoc, chunk); > } > > out: > @@ -711,7 +731,9 @@ static int sctp_send_asconf_del_ip(struct sock *sk, > struct sctp_sockaddr_entry *saddr; > int i; > int retval = 0; > + int stored = 0; > > + chunk = NULL; > if (!sctp_addip_enable) > return retval; > > @@ -762,8 +784,42 @@ static int sctp_send_asconf_del_ip(struct sock *sk, > bp = &asoc->base.bind_addr; > laddr = sctp_find_unmatch_addr(bp, (union sctp_addr *)addrs, > addrcnt, sp); > - if (!laddr) > - continue; > + if ((laddr == NULL) && (addrcnt == 1)) { > + union sctp_addr *sa_addr = NULL; > + > + if (asoc->asconf_addr_del_pending == NULL) { > + asoc->asconf_addr_del_pending = > + kmalloc(sizeof(union sctp_addr), > + GFP_ATOMIC); > + memset(asoc->asconf_addr_del_pending, 0, > + sizeof(union sctp_addr)); > + if (addrs->sa_family == AF_INET) { > + struct sockaddr_in *sin; > + > + sin = (struct sockaddr_in *)addrs; > + asoc->asconf_addr_del_pending->v4.sin_family = AF_INET; > + memcpy(&asoc->asconf_addr_del_pending->v4.sin_addr, &sin->sin_addr, sizeof(struct in_addr)); > + } else if (addrs->sa_family == AF_INET6) { > + struct sockaddr_in6 *sin6; > + > + sin6 = (struct sockaddr_in6 *)addrs; > + asoc->asconf_addr_del_pending->v6.sin6_family = AF_INET6; > + memcpy(&asoc->asconf_addr_del_pending->v6.sin6_addr, &sin6->sin6_addr, sizeof(struct in6_addr)); > + } > + sa_addr = (union sctp_addr *)addrs; > + SCTP_DEBUG_PRINTK_IPADDR("send_asconf_del_ip: keep the last address asoc: %p ", > + " at %p\n", asoc, sa_addr, > + asoc->asconf_addr_del_pending); > + stored = 1; > + goto skip_mkasconf; > + } else { > + SCTP_DEBUG_PRINTK_IPADDR("send_asconf_del_ip: asoc %p, deleting last address ", > + " is already stored at %p\n", asoc, > + asoc->asconf_addr_del_pending, > + asoc->asconf_addr_del_pending); > + continue; > + } > + } > > /* We do not need RCU protection throughout this loop > * because this is done under a socket lock from the > @@ -776,6 +832,7 @@ static int sctp_send_asconf_del_ip(struct sock *sk, > goto out; > } > > +skip_mkasconf: > /* Reset use_as_src flag for the addresses in the bind address > * list that are to be deleted. > */ > @@ -797,10 +854,16 @@ static int sctp_send_asconf_del_ip(struct sock *sk, > list_for_each_entry(transport, &asoc->peer.transport_addr_list, > transports) { > dst_release(transport->dst); > + /* Clear source address cache */ > + memset(&transport->saddr, 0, sizeof(union sctp_addr)); > sctp_transport_route(transport, NULL, > sctp_sk(asoc->base.sk)); > } > > + if (stored) { > + /* We don't need to transmit ASCONF */ > + continue; > + } > retval = sctp_send_asconf(asoc, chunk); > } > out: You should split this patch to two or more for better review: the receive side for ASCONF with ADDIP and DELIP paramaters from new IP the send side for ASCONF operation on single-homed host