| /* SCTP kernel implementation |
| * Copyright (c) 1999-2000 Cisco, Inc. |
| * Copyright (c) 1999-2001 Motorola, Inc. |
| * Copyright (c) 2001-2002 International Business Machines, Corp. |
| * Copyright (c) 2001 Intel Corp. |
| * Copyright (c) 2001 Nokia, Inc. |
| * Copyright (c) 2001 La Monte H.P. Yarroll |
| * |
| * This file is part of the SCTP kernel implementation |
| * |
| * This abstraction represents an SCTP endpoint. |
| * |
| * The SCTP implementation is free software; |
| * you can redistribute it and/or modify it under the terms of |
| * the GNU General Public License as published by |
| * the Free Software Foundation; either version 2, or (at your option) |
| * any later version. |
| * |
| * The SCTP implementation is distributed in the hope that it |
| * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
| * ************************ |
| * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| * See the GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with GNU CC; see the file COPYING. If not, see |
| * <http://www.gnu.org/licenses/>. |
| * |
| * Please send any bug reports or fixes you make to the |
| * email address(es): |
| * lksctp developers <linux-sctp@vger.kernel.org> |
| * |
| * Written or modified by: |
| * La Monte H.P. Yarroll <piggy@acm.org> |
| * Karl Knutson <karl@athena.chicago.il.us> |
| * Jon Grimm <jgrimm@austin.ibm.com> |
| * Daisy Chang <daisyc@us.ibm.com> |
| * Dajiang Zhang <dajiang.zhang@nokia.com> |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/slab.h> |
| #include <linux/in.h> |
| #include <linux/random.h> /* get_random_bytes() */ |
| #include <net/sock.h> |
| #include <net/ipv6.h> |
| #include <net/sctp/sctp.h> |
| #include <net/sctp/sm.h> |
| |
| /* Forward declarations for internal helpers. */ |
| static void sctp_endpoint_bh_rcv(struct work_struct *work); |
| |
| /* |
| * Initialize the base fields of the endpoint structure. |
| */ |
| static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep, |
| struct sock *sk, |
| gfp_t gfp) |
| { |
| struct net *net = sock_net(sk); |
| struct sctp_hmac_algo_param *auth_hmacs = NULL; |
| struct sctp_chunks_param *auth_chunks = NULL; |
| struct sctp_shared_key *null_key; |
| int err; |
| |
| ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp); |
| if (!ep->digest) |
| return NULL; |
| |
| ep->auth_enable = net->sctp.auth_enable; |
| if (ep->auth_enable) { |
| /* Allocate space for HMACS and CHUNKS authentication |
| * variables. There are arrays that we encode directly |
| * into parameters to make the rest of the operations easier. |
| */ |
| auth_hmacs = kzalloc(sizeof(*auth_hmacs) + |
| sizeof(__u16) * SCTP_AUTH_NUM_HMACS, gfp); |
| if (!auth_hmacs) |
| goto nomem; |
| |
| auth_chunks = kzalloc(sizeof(*auth_chunks) + |
| SCTP_NUM_CHUNK_TYPES, gfp); |
| if (!auth_chunks) |
| goto nomem; |
| |
| /* Initialize the HMACS parameter. |
| * SCTP-AUTH: Section 3.3 |
| * Every endpoint supporting SCTP chunk authentication MUST |
| * support the HMAC based on the SHA-1 algorithm. |
| */ |
| auth_hmacs->param_hdr.type = SCTP_PARAM_HMAC_ALGO; |
| auth_hmacs->param_hdr.length = |
| htons(sizeof(struct sctp_paramhdr) + 2); |
| auth_hmacs->hmac_ids[0] = htons(SCTP_AUTH_HMAC_ID_SHA1); |
| |
| /* Initialize the CHUNKS parameter */ |
| auth_chunks->param_hdr.type = SCTP_PARAM_CHUNKS; |
| auth_chunks->param_hdr.length = |
| htons(sizeof(struct sctp_paramhdr)); |
| |
| /* If the Add-IP functionality is enabled, we must |
| * authenticate, ASCONF and ASCONF-ACK chunks |
| */ |
| if (net->sctp.addip_enable) { |
| auth_chunks->chunks[0] = SCTP_CID_ASCONF; |
| auth_chunks->chunks[1] = SCTP_CID_ASCONF_ACK; |
| auth_chunks->param_hdr.length = |
| htons(sizeof(struct sctp_paramhdr) + 2); |
| } |
| } |
| |
| /* Initialize the base structure. */ |
| /* What type of endpoint are we? */ |
| ep->base.type = SCTP_EP_TYPE_SOCKET; |
| |
| /* Initialize the basic object fields. */ |
| refcount_set(&ep->base.refcnt, 1); |
| ep->base.dead = false; |
| |
| /* Create an input queue. */ |
| sctp_inq_init(&ep->base.inqueue); |
| |
| /* Set its top-half handler */ |
| sctp_inq_set_th_handler(&ep->base.inqueue, sctp_endpoint_bh_rcv); |
| |
| /* Initialize the bind addr area */ |
| sctp_bind_addr_init(&ep->base.bind_addr, 0); |
| |
| /* Create the lists of associations. */ |
| INIT_LIST_HEAD(&ep->asocs); |
| |
| /* Use SCTP specific send buffer space queues. */ |
| ep->sndbuf_policy = net->sctp.sndbuf_policy; |
| |
| sk->sk_data_ready = sctp_data_ready; |
| sk->sk_write_space = sctp_write_space; |
| sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); |
| |
| /* Get the receive buffer policy for this endpoint */ |
| ep->rcvbuf_policy = net->sctp.rcvbuf_policy; |
| |
| /* Initialize the secret key used with cookie. */ |
| get_random_bytes(ep->secret_key, sizeof(ep->secret_key)); |
| |
| /* SCTP-AUTH extensions*/ |
| INIT_LIST_HEAD(&ep->endpoint_shared_keys); |
| null_key = sctp_auth_shkey_create(0, gfp); |
| if (!null_key) |
| goto nomem; |
| |
| list_add(&null_key->key_list, &ep->endpoint_shared_keys); |
| |
| /* Allocate and initialize transorms arrays for supported HMACs. */ |
| err = sctp_auth_init_hmacs(ep, gfp); |
| if (err) |
| goto nomem_hmacs; |
| |
| /* Add the null key to the endpoint shared keys list and |
| * set the hmcas and chunks pointers. |
| */ |
| ep->auth_hmacs_list = auth_hmacs; |
| ep->auth_chunk_list = auth_chunks; |
| ep->prsctp_enable = net->sctp.prsctp_enable; |
| ep->reconf_enable = net->sctp.reconf_enable; |
| |
| /* Remember who we are attached to. */ |
| ep->base.sk = sk; |
| sock_hold(ep->base.sk); |
| |
| return ep; |
| |
| nomem_hmacs: |
| sctp_auth_destroy_keys(&ep->endpoint_shared_keys); |
| nomem: |
| /* Free all allocations */ |
| kfree(auth_hmacs); |
| kfree(auth_chunks); |
| kfree(ep->digest); |
| return NULL; |
| |
| } |
| |
| /* Create a sctp_endpoint with all that boring stuff initialized. |
| * Returns NULL if there isn't enough memory. |
| */ |
| struct sctp_endpoint *sctp_endpoint_new(struct sock *sk, gfp_t gfp) |
| { |
| struct sctp_endpoint *ep; |
| |
| /* Build a local endpoint. */ |
| ep = kzalloc(sizeof(*ep), gfp); |
| if (!ep) |
| goto fail; |
| |
| if (!sctp_endpoint_init(ep, sk, gfp)) |
| goto fail_init; |
| |
| SCTP_DBG_OBJCNT_INC(ep); |
| return ep; |
| |
| fail_init: |
| kfree(ep); |
| fail: |
| return NULL; |
| } |
| |
| /* Add an association to an endpoint. */ |
| void sctp_endpoint_add_asoc(struct sctp_endpoint *ep, |
| struct sctp_association *asoc) |
| { |
| struct sock *sk = ep->base.sk; |
| |
| /* If this is a temporary association, don't bother |
| * since we'll be removing it shortly and don't |
| * want anyone to find it anyway. |
| */ |
| if (asoc->temp) |
| return; |
| |
| /* Now just add it to our list of asocs */ |
| list_add_tail(&asoc->asocs, &ep->asocs); |
| |
| /* Increment the backlog value for a TCP-style listening socket. */ |
| if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) |
| sk->sk_ack_backlog++; |
| } |
| |
| /* Free the endpoint structure. Delay cleanup until |
| * all users have released their reference count on this structure. |
| */ |
| void sctp_endpoint_free(struct sctp_endpoint *ep) |
| { |
| ep->base.dead = true; |
| |
| ep->base.sk->sk_state = SCTP_SS_CLOSED; |
| |
| /* Unlink this endpoint, so we can't find it again! */ |
| sctp_unhash_endpoint(ep); |
| |
| sctp_endpoint_put(ep); |
| } |
| |
| /* Final destructor for endpoint. */ |
| static void sctp_endpoint_destroy(struct sctp_endpoint *ep) |
| { |
| struct sock *sk; |
| |
| if (unlikely(!ep->base.dead)) { |
| WARN(1, "Attempt to destroy undead endpoint %p!\n", ep); |
| return; |
| } |
| |
| /* Free the digest buffer */ |
| kfree(ep->digest); |
| |
| /* SCTP-AUTH: Free up AUTH releated data such as shared keys |
| * chunks and hmacs arrays that were allocated |
| */ |
| sctp_auth_destroy_keys(&ep->endpoint_shared_keys); |
| kfree(ep->auth_hmacs_list); |
| kfree(ep->auth_chunk_list); |
| |
| /* AUTH - Free any allocated HMAC transform containers */ |
| sctp_auth_destroy_hmacs(ep->auth_hmacs); |
| |
| /* Cleanup. */ |
| sctp_inq_free(&ep->base.inqueue); |
| sctp_bind_addr_free(&ep->base.bind_addr); |
| |
| memset(ep->secret_key, 0, sizeof(ep->secret_key)); |
| |
| sk = ep->base.sk; |
| /* Remove and free the port */ |
| if (sctp_sk(sk)->bind_hash) |
| sctp_put_port(sk); |
| |
| sctp_sk(sk)->ep = NULL; |
| /* Give up our hold on the sock */ |
| sock_put(sk); |
| |
| kfree(ep); |
| SCTP_DBG_OBJCNT_DEC(ep); |
| } |
| |
| /* Hold a reference to an endpoint. */ |
| void sctp_endpoint_hold(struct sctp_endpoint *ep) |
| { |
| refcount_inc(&ep->base.refcnt); |
| } |
| |
| /* Release a reference to an endpoint and clean up if there are |
| * no more references. |
| */ |
| void sctp_endpoint_put(struct sctp_endpoint *ep) |
| { |
| if (refcount_dec_and_test(&ep->base.refcnt)) |
| sctp_endpoint_destroy(ep); |
| } |
| |
| /* Is this the endpoint we are looking for? */ |
| struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep, |
| struct net *net, |
| const union sctp_addr *laddr) |
| { |
| struct sctp_endpoint *retval = NULL; |
| |
| if ((htons(ep->base.bind_addr.port) == laddr->v4.sin_port) && |
| net_eq(sock_net(ep->base.sk), net)) { |
| if (sctp_bind_addr_match(&ep->base.bind_addr, laddr, |
| sctp_sk(ep->base.sk))) |
| retval = ep; |
| } |
| |
| return retval; |
| } |
| |
| /* Find the association that goes with this chunk. |
| * We lookup the transport from hashtable at first, then get association |
| * through t->assoc. |
| */ |
| struct sctp_association *sctp_endpoint_lookup_assoc( |
| const struct sctp_endpoint *ep, |
| const union sctp_addr *paddr, |
| struct sctp_transport **transport) |
| { |
| struct sctp_association *asoc = NULL; |
| struct sctp_transport *t; |
| |
| *transport = NULL; |
| |
| /* If the local port is not set, there can't be any associations |
| * on this endpoint. |
| */ |
| if (!ep->base.bind_addr.port) |
| return NULL; |
| |
| rcu_read_lock(); |
| t = sctp_epaddr_lookup_transport(ep, paddr); |
| if (!t) |
| goto out; |
| |
| *transport = t; |
| asoc = t->asoc; |
| out: |
| rcu_read_unlock(); |
| return asoc; |
| } |
| |
| /* Look for any peeled off association from the endpoint that matches the |
| * given peer address. |
| */ |
| int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep, |
| const union sctp_addr *paddr) |
| { |
| struct sctp_sockaddr_entry *addr; |
| struct sctp_bind_addr *bp; |
| struct net *net = sock_net(ep->base.sk); |
| |
| bp = &ep->base.bind_addr; |
| /* This function is called with the socket lock held, |
| * so the address_list can not change. |
| */ |
| list_for_each_entry(addr, &bp->address_list, list) { |
| if (sctp_has_association(net, &addr->a, paddr)) |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| /* Do delayed input processing. This is scheduled by sctp_rcv(). |
| * This may be called on BH or task time. |
| */ |
| static void sctp_endpoint_bh_rcv(struct work_struct *work) |
| { |
| struct sctp_endpoint *ep = |
| container_of(work, struct sctp_endpoint, |
| base.inqueue.immediate); |
| struct sctp_association *asoc; |
| struct sock *sk; |
| struct net *net; |
| struct sctp_transport *transport; |
| struct sctp_chunk *chunk; |
| struct sctp_inq *inqueue; |
| union sctp_subtype subtype; |
| enum sctp_state state; |
| int error = 0; |
| int first_time = 1; /* is this the first time through the loop */ |
| |
| if (ep->base.dead) |
| return; |
| |
| asoc = NULL; |
| inqueue = &ep->base.inqueue; |
| sk = ep->base.sk; |
| net = sock_net(sk); |
| |
| while (NULL != (chunk = sctp_inq_pop(inqueue))) { |
| subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type); |
| |
| /* If the first chunk in the packet is AUTH, do special |
| * processing specified in Section 6.3 of SCTP-AUTH spec |
| */ |
| if (first_time && (subtype.chunk == SCTP_CID_AUTH)) { |
| struct sctp_chunkhdr *next_hdr; |
| |
| next_hdr = sctp_inq_peek(inqueue); |
| if (!next_hdr) |
| goto normal; |
| |
| /* If the next chunk is COOKIE-ECHO, skip the AUTH |
| * chunk while saving a pointer to it so we can do |
| * Authentication later (during cookie-echo |
| * processing). |
| */ |
| if (next_hdr->type == SCTP_CID_COOKIE_ECHO) { |
| chunk->auth_chunk = skb_clone(chunk->skb, |
| GFP_ATOMIC); |
| chunk->auth = 1; |
| continue; |
| } |
| } |
| normal: |
| /* We might have grown an association since last we |
| * looked, so try again. |
| * |
| * This happens when we've just processed our |
| * COOKIE-ECHO chunk. |
| */ |
| if (NULL == chunk->asoc) { |
| asoc = sctp_endpoint_lookup_assoc(ep, |
| sctp_source(chunk), |
| &transport); |
| chunk->asoc = asoc; |
| chunk->transport = transport; |
| } |
| |
| state = asoc ? asoc->state : SCTP_STATE_CLOSED; |
| if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth) |
| continue; |
| |
| /* Remember where the last DATA chunk came from so we |
| * know where to send the SACK. |
| */ |
| if (asoc && sctp_chunk_is_data(chunk)) |
| asoc->peer.last_data_from = chunk->transport; |
| else { |
| SCTP_INC_STATS(sock_net(ep->base.sk), SCTP_MIB_INCTRLCHUNKS); |
| if (asoc) |
| asoc->stats.ictrlchunks++; |
| } |
| |
| if (chunk->transport) |
| chunk->transport->last_time_heard = ktime_get(); |
| |
| error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype, state, |
| ep, asoc, chunk, GFP_ATOMIC); |
| |
| if (error && chunk) |
| chunk->pdiscard = 1; |
| |
| /* Check to see if the endpoint is freed in response to |
| * the incoming chunk. If so, get out of the while loop. |
| */ |
| if (!sctp_sk(sk)->ep) |
| break; |
| |
| if (first_time) |
| first_time = 0; |
| } |
| } |