/* SCTP kernel implementation * (C) Copyright IBM Corp. 2001, 2003 * Copyright (c) Cisco 1999,2000 * Copyright (c) Motorola 1999,2000,2001 * Copyright (c) La Monte H.P. Yarroll 2001 * * This file is part of the SCTP kernel implementation. * * A collection class to handle the storage of transport addresses. * * This 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. * * This 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@us.ibm.com> * Daisy Chang <daisyc@us.ibm.com> */ #include <linux/types.h> #include <linux/slab.h> #include <linux/in.h> #include <net/sock.h> #include <net/ipv6.h> #include <net/if_inet6.h> #include <net/sctp/sctp.h> #include <net/sctp/sm.h> /* Forward declarations for internal helpers. */ static int sctp_copy_one_addr(struct net *, struct sctp_bind_addr *, union sctp_addr *, sctp_scope_t scope, gfp_t gfp, int flags); static void sctp_bind_addr_clean(struct sctp_bind_addr *); /* First Level Abstractions. */ /* Copy 'src' to 'dest' taking 'scope' into account. Omit addresses * in 'src' which have a broader scope than 'scope'. */ int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest, const struct sctp_bind_addr *src, sctp_scope_t scope, gfp_t gfp, int flags) { struct sctp_sockaddr_entry *addr; int error = 0; /* All addresses share the same port. */ dest->port = src->port; /* Extract the addresses which are relevant for this scope. */ list_for_each_entry(addr, &src->address_list, list) { error = sctp_copy_one_addr(net, dest, &addr->a, scope, gfp, flags); if (error < 0) goto out; } /* If there are no addresses matching the scope and * this is global scope, try to get a link scope address, with * the assumption that we must be sitting behind a NAT. */ if (list_empty(&dest->address_list) && (SCTP_SCOPE_GLOBAL == scope)) { list_for_each_entry(addr, &src->address_list, list) { error = sctp_copy_one_addr(net, dest, &addr->a, SCTP_SCOPE_LINK, gfp, flags); if (error < 0) goto out; } } out: if (error) sctp_bind_addr_clean(dest); return error; } /* Exactly duplicate the address lists. This is necessary when doing * peer-offs and accepts. We don't want to put all the current system * addresses into the endpoint. That's useless. But we do want duplicat * the list of bound addresses that the older endpoint used. */ int sctp_bind_addr_dup(struct sctp_bind_addr *dest, const struct sctp_bind_addr *src, gfp_t gfp) { struct sctp_sockaddr_entry *addr; int error = 0; /* All addresses share the same port. */ dest->port = src->port; list_for_each_entry(addr, &src->address_list, list) { error = sctp_add_bind_addr(dest, &addr->a, sizeof(addr->a), 1, gfp); if (error < 0) break; } return error; } /* Initialize the SCTP_bind_addr structure for either an endpoint or * an association. */ void sctp_bind_addr_init(struct sctp_bind_addr *bp, __u16 port) { INIT_LIST_HEAD(&bp->address_list); bp->port = port; } /* Dispose of the address list. */ static void sctp_bind_addr_clean(struct sctp_bind_addr *bp) { struct sctp_sockaddr_entry *addr, *temp; /* Empty the bind address list. */ list_for_each_entry_safe(addr, temp, &bp->address_list, list) { list_del_rcu(&addr->list); kfree_rcu(addr, rcu); SCTP_DBG_OBJCNT_DEC(addr); } } /* Dispose of an SCTP_bind_addr structure */ void sctp_bind_addr_free(struct sctp_bind_addr *bp) { /* Empty the bind address list. */ sctp_bind_addr_clean(bp); } /* Add an address to the bind address list in the SCTP_bind_addr structure. */ int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new, int new_size, __u8 addr_state, gfp_t gfp) { struct sctp_sockaddr_entry *addr; /* Add the address to the bind address list. */ addr = kzalloc(sizeof(*addr), gfp); if (!addr) return -ENOMEM; memcpy(&addr->a, new, min_t(size_t, sizeof(*new), new_size)); /* Fix up the port if it has not yet been set. * Both v4 and v6 have the port at the same offset. */ if (!addr->a.v4.sin_port) addr->a.v4.sin_port = htons(bp->port); addr->state = addr_state; addr->valid = 1; INIT_LIST_HEAD(&addr->list); /* We always hold a socket lock when calling this function, * and that acts as a writer synchronizing lock. */ list_add_tail_rcu(&addr->list, &bp->address_list); SCTP_DBG_OBJCNT_INC(addr); return 0; } /* Delete an address from the bind address list in the SCTP_bind_addr * structure. */ int sctp_del_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *del_addr) { struct sctp_sockaddr_entry *addr, *temp; int found = 0; /* We hold the socket lock when calling this function, * and that acts as a writer synchronizing lock. */ list_for_each_entry_safe(addr, temp, &bp->address_list, list) { if (sctp_cmp_addr_exact(&addr->a, del_addr)) { /* Found the exact match. */ found = 1; addr->valid = 0; list_del_rcu(&addr->list); break; } } if (found) { kfree_rcu(addr, rcu); SCTP_DBG_OBJCNT_DEC(addr); return 0; } return -EINVAL; } /* Create a network byte-order representation of all the addresses * formated as SCTP parameters. * * The second argument is the return value for the length. */ union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, int *addrs_len, gfp_t gfp) { union sctp_params addrparms; union sctp_params retval; int addrparms_len; union sctp_addr_param rawaddr; int len; struct sctp_sockaddr_entry *addr; struct list_head *pos; struct sctp_af *af; addrparms_len = 0; len = 0; /* Allocate enough memory at once. */ list_for_each(pos, &bp->address_list) { len += sizeof(union sctp_addr_param); } /* Don't even bother embedding an address if there * is only one. */ if (len == sizeof(union sctp_addr_param)) { retval.v = NULL; goto end_raw; } retval.v = kmalloc(len, gfp); if (!retval.v) goto end_raw; addrparms = retval; list_for_each_entry(addr, &bp->address_list, list) { af = sctp_get_af_specific(addr->a.v4.sin_family); len = af->to_addr_param(&addr->a, &rawaddr); memcpy(addrparms.v, &rawaddr, len); addrparms.v += len; addrparms_len += len; } end_raw: *addrs_len = addrparms_len; return retval; } /* * Create an address list out of the raw address list format (IPv4 and IPv6 * address parameters). */ int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw_addr_list, int addrs_len, __u16 port, gfp_t gfp) { union sctp_addr_param *rawaddr; struct sctp_paramhdr *param; union sctp_addr addr; int retval = 0; int len; struct sctp_af *af; /* Convert the raw address to standard address format */ while (addrs_len) { param = (struct sctp_paramhdr *)raw_addr_list; rawaddr = (union sctp_addr_param *)raw_addr_list; af = sctp_get_af_specific(param_type2af(param->type)); if (unlikely(!af)) { retval = -EINVAL; sctp_bind_addr_clean(bp); break; } af->from_addr_param(&addr, rawaddr, htons(port), 0); if (sctp_bind_addr_state(bp, &addr) != -1) goto next; retval = sctp_add_bind_addr(bp, &addr, sizeof(addr), SCTP_ADDR_SRC, gfp); if (retval) { /* Can't finish building the list, clean up. */ sctp_bind_addr_clean(bp); break; } next: len = ntohs(param->length); addrs_len -= len; raw_addr_list += len; } return retval; } /******************************************************************** * 2nd Level Abstractions ********************************************************************/ /* Does this contain a specified address? Allow wildcarding. */ int sctp_bind_addr_match(struct sctp_bind_addr *bp, const union sctp_addr *addr, struct sctp_sock *opt) { struct sctp_sockaddr_entry *laddr; int match = 0; rcu_read_lock(); list_for_each_entry_rcu(laddr, &bp->address_list, list) { if (!laddr->valid) continue; if (opt->pf->cmp_addr(&laddr->a, addr, opt)) { match = 1; break; } } rcu_read_unlock(); return match; } /* Does the address 'addr' conflict with any addresses in * the bp. */ int sctp_bind_addr_conflict(struct sctp_bind_addr *bp, const union sctp_addr *addr, struct sctp_sock *bp_sp, struct sctp_sock *addr_sp) { struct sctp_sockaddr_entry *laddr; int conflict = 0; struct sctp_sock *sp; /* Pick the IPv6 socket as the basis of comparison * since it's usually a superset of the IPv4. * If there is no IPv6 socket, then default to bind_addr. */ if (sctp_opt2sk(bp_sp)->sk_family == AF_INET6) sp = bp_sp; else if (sctp_opt2sk(addr_sp)->sk_family == AF_INET6) sp = addr_sp; else sp = bp_sp; rcu_read_lock(); list_for_each_entry_rcu(laddr, &bp->address_list, list) { if (!laddr->valid) continue; conflict = sp->pf->cmp_addr(&laddr->a, addr, sp); if (conflict) break; } rcu_read_unlock(); return conflict; } /* Get the state of the entry in the bind_addr_list */ int sctp_bind_addr_state(const struct sctp_bind_addr *bp, const union sctp_addr *addr) { struct sctp_sockaddr_entry *laddr; struct sctp_af *af; int state = -1; af = sctp_get_af_specific(addr->sa.sa_family); if (unlikely(!af)) return state; rcu_read_lock(); list_for_each_entry_rcu(laddr, &bp->address_list, list) { if (!laddr->valid) continue; if (af->cmp_addr(&laddr->a, addr)) { state = laddr->state; break; } } rcu_read_unlock(); return state; } /* Find the first address in the bind address list that is not present in * the addrs packed array. */ union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, const union sctp_addr *addrs, int addrcnt, struct sctp_sock *opt) { struct sctp_sockaddr_entry *laddr; union sctp_addr *addr; void *addr_buf; struct sctp_af *af; int i; /* This is only called sctp_send_asconf_del_ip() and we hold * the socket lock in that code patch, so that address list * can't change. */ list_for_each_entry(laddr, &bp->address_list, list) { addr_buf = (union sctp_addr *)addrs; for (i = 0; i < addrcnt; i++) { addr = addr_buf; af = sctp_get_af_specific(addr->v4.sin_family); if (!af) break; if (opt->pf->cmp_addr(&laddr->a, addr, opt)) break; addr_buf += af->sockaddr_len; } if (i == addrcnt) return &laddr->a; } return NULL; } /* Copy out addresses from the global local address list. */ static int sctp_copy_one_addr(struct net *net, struct sctp_bind_addr *dest, union sctp_addr *addr, sctp_scope_t scope, gfp_t gfp, int flags) { int error = 0; if (sctp_is_any(NULL, addr)) { error = sctp_copy_local_addr_list(net, dest, scope, gfp, flags); } else if (sctp_in_scope(net, addr, scope)) { /* Now that the address is in scope, check to see if * the address type is supported by local sock as * well as the remote peer. */ if ((((AF_INET == addr->sa.sa_family) && (flags & SCTP_ADDR4_PEERSUPP))) || (((AF_INET6 == addr->sa.sa_family) && (flags & SCTP_ADDR6_ALLOWED) && (flags & SCTP_ADDR6_PEERSUPP)))) error = sctp_add_bind_addr(dest, addr, sizeof(*addr), SCTP_ADDR_SRC, gfp); } return error; } /* Is this a wildcard address? */ int sctp_is_any(struct sock *sk, const union sctp_addr *addr) { unsigned short fam = 0; struct sctp_af *af; /* Try to get the right address family */ if (addr->sa.sa_family != AF_UNSPEC) fam = addr->sa.sa_family; else if (sk) fam = sk->sk_family; af = sctp_get_af_specific(fam); if (!af) return 0; return af->is_any(addr); } /* Is 'addr' valid for 'scope'? */ int sctp_in_scope(struct net *net, const union sctp_addr *addr, sctp_scope_t scope) { sctp_scope_t addr_scope = sctp_scope(addr); /* The unusable SCTP addresses will not be considered with * any defined scopes. */ if (SCTP_SCOPE_UNUSABLE == addr_scope) return 0; /* * For INIT and INIT-ACK address list, let L be the level of * of requested destination address, sender and receiver * SHOULD include all of its addresses with level greater * than or equal to L. * * Address scoping can be selectively controlled via sysctl * option */ switch (net->sctp.scope_policy) { case SCTP_SCOPE_POLICY_DISABLE: return 1; case SCTP_SCOPE_POLICY_ENABLE: if (addr_scope <= scope) return 1; break; case SCTP_SCOPE_POLICY_PRIVATE: if (addr_scope <= scope || SCTP_SCOPE_PRIVATE == addr_scope) return 1; break; case SCTP_SCOPE_POLICY_LINK: if (addr_scope <= scope || SCTP_SCOPE_LINK == addr_scope) return 1; break; default: break; } return 0; } int sctp_is_ep_boundall(struct sock *sk) { struct sctp_bind_addr *bp; struct sctp_sockaddr_entry *addr; bp = &sctp_sk(sk)->ep->base.bind_addr; if (sctp_list_single_entry(&bp->address_list)) { addr = list_entry(bp->address_list.next, struct sctp_sockaddr_entry, list); if (sctp_is_any(sk, &addr->a)) return 1; } return 0; } /******************************************************************** * 3rd Level Abstractions ********************************************************************/ /* What is the scope of 'addr'? */ sctp_scope_t sctp_scope(const union sctp_addr *addr) { struct sctp_af *af; af = sctp_get_af_specific(addr->sa.sa_family); if (!af) return SCTP_SCOPE_UNUSABLE; return af->scope((union sctp_addr *)addr); }