diff options
Diffstat (limited to 'net/sctp/endpointola.c')
| -rw-r--r-- | net/sctp/endpointola.c | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c new file mode 100644 index 000000000..efffde7f2 --- /dev/null +++ b/net/sctp/endpointola.c @@ -0,0 +1,417 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* 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. + * + * 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_shared_key *null_key; + + ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp); + if (!ep->digest) + return NULL; + + ep->asconf_enable = net->sctp.addip_enable; + ep->auth_enable = net->sctp.auth_enable; + if (ep->auth_enable) { + if (sctp_auth_init(ep, gfp)) + goto nomem; + if (ep->asconf_enable) { + sctp_auth_ep_add_chunkid(ep, SCTP_CID_ASCONF); + sctp_auth_ep_add_chunkid(ep, SCTP_CID_ASCONF_ACK); + } + } + + /* 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_shkey; + + list_add(&null_key->key_list, &ep->endpoint_shared_keys); + + /* Add the null key to the endpoint shared keys list and + * set the hmcas and chunks pointers. + */ + ep->prsctp_enable = net->sctp.prsctp_enable; + ep->reconf_enable = net->sctp.reconf_enable; + ep->ecn_enable = net->sctp.ecn_enable; + + /* Remember who we are attached to. */ + ep->base.sk = sk; + ep->base.net = sock_net(sk); + sock_hold(ep->base.sk); + + return ep; + +nomem_shkey: + sctp_auth_free(ep); +nomem: + 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_acceptq_added(sk); +} + +/* 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; + + inet_sk_set_state(ep->base.sk, 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_rcu(struct rcu_head *head) +{ + struct sctp_endpoint *ep = container_of(head, struct sctp_endpoint, rcu); + struct sock *sk = ep->base.sk; + + sctp_sk(sk)->ep = NULL; + sock_put(sk); + + kfree(ep); + SCTP_DBG_OBJCNT_DEC(ep); +} + +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); + sctp_auth_free(ep); + + /* 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); + + call_rcu(&ep->rcu, sctp_endpoint_destroy_rcu); +} + +/* Hold a reference to an endpoint. */ +int sctp_endpoint_hold(struct sctp_endpoint *ep) +{ + return refcount_inc_not_zero(&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(ep->base.net, 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. + */ +bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep, + const union sctp_addr *paddr) +{ + struct sctp_sockaddr_entry *addr; + struct net *net = ep->base.net; + struct sctp_bind_addr *bp; + + 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 true; + } + + return false; +} + +/* 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(ep->base.net, 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; + } +} |