/* SCTP kernel reference 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 reference Implementation * * This abstraction represents an SCTP endpoint. * * This file is part of the implementation of the add-IP extension, * based on <draft-ietf-tsvwg-addip-sctp-02.txt> June 29, 2001, * for the SCTP kernel reference Implementation. * * The SCTP reference 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 reference 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, write to * the Free Software Foundation, 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. * * Please send any bug reports or fixes you make to the * email address(es): * lksctp developers <lksctp-developers@lists.sourceforge.net> * * Or submit a bug report through the following website: * http://www.sf.net/projects/lksctp * * 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> * * Any bugs reported given to us we will try to fix... any fixes shared will * be incorporated into the next SCTP release. */ #include <linux/types.h> #include <linux/slab.h> #include <linux/in.h> #include <linux/random.h> /* get_random_bytes() */ #include <linux/crypto.h> #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) { memset(ep, 0, sizeof(struct sctp_endpoint)); ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp); if (!ep->digest) return NULL; /* Initialize the base structure. */ /* What type of endpoint are we? */ ep->base.type = SCTP_EP_TYPE_SOCKET; /* Initialize the basic object fields. */ atomic_set(&ep->base.refcnt, 1); ep->base.dead = 0; ep->base.malloced = 1; /* 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); rwlock_init(&ep->base.addr_lock); /* Remember who we are attached to. */ ep->base.sk = sk; sock_hold(ep->base.sk); /* Create the lists of associations. */ INIT_LIST_HEAD(&ep->asocs); /* Use SCTP specific send buffer space queues. */ ep->sndbuf_policy = sctp_sndbuf_policy; 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 = sctp_rcvbuf_policy; /* Initialize the secret key used with cookie. */ get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE); ep->last_key = ep->current_key = 0; ep->key_changed_at = jiffies; return ep; } /* 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 = t_new(struct sctp_endpoint, gfp); if (!ep) goto fail; if (!sctp_endpoint_init(ep, sk, gfp)) goto fail_init; ep->base.malloced = 1; 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 = 1; 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) { SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return); /* Free up the HMAC transform. */ crypto_free_hash(sctp_sk(ep->base.sk)->hmac); /* Free the digest buffer */ kfree(ep->digest); /* Cleanup. */ sctp_inq_free(&ep->base.inqueue); sctp_bind_addr_free(&ep->base.bind_addr); /* Remove and free the port */ if (sctp_sk(ep->base.sk)->bind_hash) sctp_put_port(ep->base.sk); /* Give up our hold on the sock. */ if (ep->base.sk) sock_put(ep->base.sk); /* Finally, free up our memory. */ if (ep->base.malloced) { kfree(ep); SCTP_DBG_OBJCNT_DEC(ep); } } /* Hold a reference to an endpoint. */ void sctp_endpoint_hold(struct sctp_endpoint *ep) { atomic_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 (atomic_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, const union sctp_addr *laddr) { struct sctp_endpoint *retval; sctp_read_lock(&ep->base.addr_lock); if (htons(ep->base.bind_addr.port) == laddr->v4.sin_port) { if (sctp_bind_addr_match(&ep->base.bind_addr, laddr, sctp_sk(ep->base.sk))) { retval = ep; goto out; } } retval = NULL; out: sctp_read_unlock(&ep->base.addr_lock); return retval; } /* Find the association that goes with this chunk. * We do a linear search of the associations for this endpoint. * We return the matching transport address too. */ static struct sctp_association *__sctp_endpoint_lookup_assoc( const struct sctp_endpoint *ep, const union sctp_addr *paddr, struct sctp_transport **transport) { int rport; struct sctp_association *asoc; struct list_head *pos; rport = ntohs(paddr->v4.sin_port); list_for_each(pos, &ep->asocs) { asoc = list_entry(pos, struct sctp_association, asocs); if (rport == asoc->peer.port) { sctp_read_lock(&asoc->base.addr_lock); *transport = sctp_assoc_lookup_paddr(asoc, paddr); sctp_read_unlock(&asoc->base.addr_lock); if (*transport) return asoc; } } *transport = NULL; return NULL; } /* Lookup association on an endpoint based on a peer address. BH-safe. */ 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; sctp_local_bh_disable(); asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport); sctp_local_bh_enable(); 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 list_head *pos; struct sctp_sockaddr_entry *addr; struct sctp_bind_addr *bp; sctp_read_lock(&ep->base.addr_lock); bp = &ep->base.bind_addr; list_for_each(pos, &bp->address_list) { addr = list_entry(pos, struct sctp_sockaddr_entry, list); if (sctp_has_association(&addr->a, paddr)) { sctp_read_unlock(&ep->base.addr_lock); return 1; } } sctp_read_unlock(&ep->base.addr_lock); 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 sctp_transport *transport; struct sctp_chunk *chunk; struct sctp_inq *inqueue; sctp_subtype_t subtype; sctp_state_t state; int error = 0; if (ep->base.dead) return; asoc = NULL; inqueue = &ep->base.inqueue; sk = ep->base.sk; while (NULL != (chunk = sctp_inq_pop(inqueue))) { subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type); /* 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; /* 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(SCTP_MIB_INCTRLCHUNKS); if (chunk->transport) chunk->transport->last_time_heard = jiffies; error = sctp_do_sm(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; } }