sctp: add support for SCTP_DSTADDRV4/6 Information for sendmsg

This patch is to add support for Destination IPv4/6 Address options
for sendmsg, as described in section 5.3.9/10 of RFC6458.

With this option, you can provide more than one destination addrs
to sendmsg when creating asoc, like sctp_connectx.

It's also a necessary send info for sctp_sendv.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xin Long
2018-03-05 20:44:19 +08:00
committed by David S. Miller
parent ed63afb8a3
commit 2c0dbaa0c4
3 changed files with 84 additions and 0 deletions

View File

@@ -1676,6 +1676,7 @@ static int sctp_sendmsg_new_asoc(struct sock *sk, __u16 sflags,
struct net *net = sock_net(sk);
struct sctp_association *asoc;
enum sctp_scope scope;
struct cmsghdr *cmsg;
int err = -EINVAL;
*tp = NULL;
@@ -1741,6 +1742,67 @@ static int sctp_sendmsg_new_asoc(struct sock *sk, __u16 sflags,
goto free;
}
if (!cmsgs->addrs_msg)
return 0;
/* sendv addr list parse */
for_each_cmsghdr(cmsg, cmsgs->addrs_msg) {
struct sctp_transport *transport;
struct sctp_association *old;
union sctp_addr _daddr;
int dlen;
if (cmsg->cmsg_level != IPPROTO_SCTP ||
(cmsg->cmsg_type != SCTP_DSTADDRV4 &&
cmsg->cmsg_type != SCTP_DSTADDRV6))
continue;
daddr = &_daddr;
memset(daddr, 0, sizeof(*daddr));
dlen = cmsg->cmsg_len - sizeof(struct cmsghdr);
if (cmsg->cmsg_type == SCTP_DSTADDRV4) {
if (dlen < sizeof(struct in_addr))
goto free;
dlen = sizeof(struct in_addr);
daddr->v4.sin_family = AF_INET;
daddr->v4.sin_port = htons(asoc->peer.port);
memcpy(&daddr->v4.sin_addr, CMSG_DATA(cmsg), dlen);
} else {
if (dlen < sizeof(struct in6_addr))
goto free;
dlen = sizeof(struct in6_addr);
daddr->v6.sin6_family = AF_INET6;
daddr->v6.sin6_port = htons(asoc->peer.port);
memcpy(&daddr->v6.sin6_addr, CMSG_DATA(cmsg), dlen);
}
err = sctp_verify_addr(sk, daddr, sizeof(*daddr));
if (err)
goto free;
old = sctp_endpoint_lookup_assoc(ep, daddr, &transport);
if (old && old != asoc) {
if (old->state >= SCTP_STATE_ESTABLISHED)
err = -EISCONN;
else
err = -EALREADY;
goto free;
}
if (sctp_endpoint_is_peeled_off(ep, daddr)) {
err = -EADDRNOTAVAIL;
goto free;
}
transport = sctp_assoc_add_peer(asoc, daddr, GFP_KERNEL,
SCTP_UNKNOWN);
if (!transport) {
err = -ENOMEM;
goto free;
}
}
return 0;
free:
@@ -7778,6 +7840,21 @@ static int sctp_msghdr_parse(const struct msghdr *msg, struct sctp_cmsgs *cmsgs)
if (cmsgs->prinfo->pr_policy == SCTP_PR_SCTP_NONE)
cmsgs->prinfo->pr_value = 0;
break;
case SCTP_DSTADDRV4:
case SCTP_DSTADDRV6:
/* SCTP Socket API Extension
* 5.3.9/10 SCTP Destination IPv4/6 Address Structure (SCTP_DSTADDRV4/6)
*
* This cmsghdr structure specifies SCTP options for sendmsg().
*
* cmsg_level cmsg_type cmsg_data[]
* ------------ ------------ ---------------------
* IPPROTO_SCTP SCTP_DSTADDRV4 struct in_addr
* ------------ ------------ ---------------------
* IPPROTO_SCTP SCTP_DSTADDRV6 struct in6_addr
*/
cmsgs->addrs_msg = my_msg;
break;
default:
return -EINVAL;
}