On Tue, Jul 23, 2019 at 01:37:58AM +0800, Xin Long wrote:
> __sctp_connect is doing quit similar things as sctp_sendmsg_new_asoc.
> To factor out common functions, this patch is to clean up their code
> to make them look more similar:
>
> 1. create the asoc and add a peer with the 1st addr.
> 2. add peers with the other addrs into this asoc one by one.
>
> Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
> ---
> net/sctp/socket.c | 211 +++++++++++++++++++-----------------------------------
> 1 file changed, 75 insertions(+), 136 deletions(-)
>
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index 5f92e4a..49837e9 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -1049,154 +1049,108 @@ static int sctp_setsockopt_bindx(struct sock *sk,
> * Common routine for handling connect() and sctp_connectx().
> * Connect will come in with just a single address.
> */
> -static int __sctp_connect(struct sock *sk,
> - struct sockaddr *kaddrs,
> - int addrs_size, int flags,
> - sctp_assoc_t *assoc_id)
> +static int __sctp_connect(struct sock *sk, struct sockaddr *kaddrs,
> + int addrs_size, int flags, sctp_assoc_t *assoc_id)
> {
> - struct net *net = sock_net(sk);
> - struct sctp_sock *sp;
> - struct sctp_endpoint *ep;
> - struct sctp_association *asoc = NULL;
> - struct sctp_association *asoc2;
> + struct sctp_association *old, *asoc;
> + struct sctp_sock *sp = sctp_sk(sk);
> + struct sctp_endpoint *ep = sp->ep;
> struct sctp_transport *transport;
> - union sctp_addr to;
> + struct net *net = sock_net(sk);
> + int addrcnt, walk_size, err;
> + void *addr_buf = kaddrs;
> + union sctp_addr *daddr;
> enum sctp_scope scope;
> + struct sctp_af *af;
> long timeo;
> - int err = 0;
> - int addrcnt = 0;
> - int walk_size = 0;
> - union sctp_addr *sa_addr = NULL;
> - void *addr_buf;
> - unsigned short port;
>
> - sp = sctp_sk(sk);
> - ep = sp->ep;
> -
> - /* connect() cannot be done on a socket that is already in ESTABLISHED
> - * state - UDP-style peeled off socket or a TCP-style socket that
> - * is already connected.
> - * It cannot be done even on a TCP-style listening socket.
> - */
> if (sctp_sstate(sk, ESTABLISHED) || sctp_sstate(sk, CLOSING) ||
> - (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))) {
> - err = -EISCONN;
> - goto out_free;
> + (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)))
> + return -EISCONN;
> +
> + daddr = addr_buf;
> + af = sctp_get_af_specific(daddr->sa.sa_family);
> + if (!af || af->sockaddr_len > addrs_size)
> + return -EINVAL;
> +
> + err = sctp_verify_addr(sk, daddr, af->sockaddr_len);
> + if (err)
> + return err;
> +
> + asoc = sctp_endpoint_lookup_assoc(ep, daddr, &transport);
> + if (asoc)
> + return asoc->state >= SCTP_STATE_ESTABLISHED ? -EISCONN
> + : -EALREADY;
> +
> + if (sctp_endpoint_is_peeled_off(ep, daddr))
> + return -EADDRNOTAVAIL;
> +
> + if (!ep->base.bind_addr.port) {
> + if (sctp_autobind(sk))
> + return -EAGAIN;
> + } else {
> + if (ep->base.bind_addr.port < inet_prot_sock(net) &&
> + !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
> + return -EACCES;
> }
>
> - /* Walk through the addrs buffer and count the number of addresses. */
> - addr_buf = kaddrs;
> - while (walk_size < addrs_size) {
> - struct sctp_af *af;
> + scope = sctp_scope(daddr);
> + asoc = sctp_association_new(ep, sk, scope, GFP_KERNEL);
> + if (!asoc)
> + return -ENOMEM;
>
> - if (walk_size + sizeof(sa_family_t) > addrs_size) {
> - err = -EINVAL;
> - goto out_free;
> - }
> + err = sctp_assoc_set_bind_addr_from_ep(asoc, scope, GFP_KERNEL);
> + if (err < 0)
> + goto out_free;
>
> - sa_addr = addr_buf;
> - af = sctp_get_af_specific(sa_addr->sa.sa_family);
> + transport = sctp_assoc_add_peer(asoc, daddr, GFP_KERNEL, SCTP_UNKNOWN);
> + if (!transport) {
> + err = -ENOMEM;
> + goto out_free;
> + }
>
> - /* If the address family is not supported or if this address
> - * causes the address buffer to overflow return EINVAL.
> - */
> - if (!af || (walk_size + af->sockaddr_len) > addrs_size) {
> - err = -EINVAL;
> + addr_buf += af->sockaddr_len;
> + walk_size = af->sockaddr_len;
> + addrcnt = 1;
This variable can be removed (in a follow-up patch). It's only
incremented and never used other than that.
> + while (walk_size < addrs_size) {
> + err = -EINVAL;
> + if (walk_size + sizeof(sa_family_t) > addrs_size)
> goto out_free;
> - }
> -
> - port = ntohs(sa_addr->v4.sin_port);
>
> - /* Save current address so we can work with it */
> - memcpy(&to, sa_addr, af->sockaddr_len);
> + daddr = addr_buf;
> + af = sctp_get_af_specific(daddr->sa.sa_family);
> + if (!af || af->sockaddr_len + walk_size > addrs_size)
> + goto out_free;
>
> - err = sctp_verify_addr(sk, &to, af->sockaddr_len);
> - if (err)
> + if (asoc->peer.port != ntohs(daddr->v4.sin_port))
> goto out_free;
>
> - /* Make sure the destination port is correctly set
> - * in all addresses.
> - */
> - if (asoc && asoc->peer.port && asoc->peer.port != port) {
> - err = -EINVAL;
> + err = sctp_verify_addr(sk, daddr, af->sockaddr_len);
> + if (err)
> goto out_free;
> - }
>
> - /* Check if there already is a matching association on the
> - * endpoint (other than the one created here).
> - */
> - asoc2 = sctp_endpoint_lookup_assoc(ep, &to, &transport);
> - if (asoc2 && asoc2 != asoc) {
> - if (asoc2->state >= SCTP_STATE_ESTABLISHED)
> - err = -EISCONN;
> - else
> - err = -EALREADY;
> + old = sctp_endpoint_lookup_assoc(ep, daddr, &transport);
> + if (old && old != asoc) {
> + err = old->state >= SCTP_STATE_ESTABLISHED ? -EISCONN
> + : -EALREADY;
> goto out_free;
> }
>
> - /* If we could not find a matching association on the endpoint,
> - * make sure that there is no peeled-off association matching
> - * the peer address even on another socket.
> - */
> - if (sctp_endpoint_is_peeled_off(ep, &to)) {
> + if (sctp_endpoint_is_peeled_off(ep, daddr)) {
> err = -EADDRNOTAVAIL;
> goto out_free;
> }
>
> - if (!asoc) {
> - /* If a bind() or sctp_bindx() is not called prior to
> - * an sctp_connectx() call, the system picks an
> - * ephemeral port and will choose an address set
> - * equivalent to binding with a wildcard address.
> - */
> - if (!ep->base.bind_addr.port) {
> - if (sctp_autobind(sk)) {
> - err = -EAGAIN;
> - goto out_free;
> - }
> - } else {
> - /*
> - * If an unprivileged user inherits a 1-many
> - * style socket with open associations on a
> - * privileged port, it MAY be permitted to
> - * accept new associations, but it SHOULD NOT
> - * be permitted to open new associations.
> - */
> - if (ep->base.bind_addr.port <
> - inet_prot_sock(net) &&
> - !ns_capable(net->user_ns,
> - CAP_NET_BIND_SERVICE)) {
> - err = -EACCES;
> - goto out_free;
> - }
> - }
> -
> - scope = sctp_scope(&to);
> - asoc = sctp_association_new(ep, sk, scope, GFP_KERNEL);
> - if (!asoc) {
> - err = -ENOMEM;
> - goto out_free;
> - }
> -
> - err = sctp_assoc_set_bind_addr_from_ep(asoc, scope,
> - GFP_KERNEL);
> - if (err < 0) {
> - goto out_free;
> - }
> -
> - }
> -
> - /* Prime the peer's transport structures. */
> - transport = sctp_assoc_add_peer(asoc, &to, GFP_KERNEL,
> + transport = sctp_assoc_add_peer(asoc, daddr, GFP_KERNEL,
> SCTP_UNKNOWN);
> if (!transport) {
> err = -ENOMEM;
> goto out_free;
> }
>
> - addrcnt++;
> - addr_buf += af->sockaddr_len;
> + addr_buf += af->sockaddr_len;
> walk_size += af->sockaddr_len;
> + addrcnt++;
> }
>
> /* In case the user of sctp_connectx() wants an association
> @@ -1209,39 +1163,24 @@ static int __sctp_connect(struct sock *sk,
> }
>
> err = sctp_primitive_ASSOCIATE(net, asoc, NULL);
> - if (err < 0) {
> + if (err < 0)
> goto out_free;
> - }
>
> /* Initialize sk's dport and daddr for getpeername() */
> inet_sk(sk)->inet_dport = htons(asoc->peer.port);
> - sp->pf->to_sk_daddr(sa_addr, sk);
> + sp->pf->to_sk_daddr(daddr, sk);
> sk->sk_err = 0;
>
> - timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
> -
> if (assoc_id)
> *assoc_id = asoc->assoc_id;
>
> - err = sctp_wait_for_connect(asoc, &timeo);
> - /* Note: the asoc may be freed after the return of
> - * sctp_wait_for_connect.
> - */
> -
> - /* Don't free association on exit. */
> - asoc = NULL;
> + timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
> + return sctp_wait_for_connect(asoc, &timeo);
>
> out_free:
> pr_debug("%s: took out_free path with asoc:%p kaddrs:%p err:%d\n",
> __func__, asoc, kaddrs, err);
> -
> - if (asoc) {
> - /* sctp_primitive_ASSOCIATE may have added this association
> - * To the hash table, try to unhash it, just in case, its a noop
> - * if it wasn't hashed so we're safe
> - */
> - sctp_association_free(asoc);
> - }
> + sctp_association_free(asoc);
> return err;
> }
>
> --
> 2.1.0
>
