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Diffstat (limited to '')
-rw-r--r-- | net/sctp/bind_addr.c | 575 |
1 files changed, 575 insertions, 0 deletions
diff --git a/net/sctp/bind_addr.c b/net/sctp/bind_addr.c new file mode 100644 index 000000000..6b95d3ba8 --- /dev/null +++ b/net/sctp/bind_addr.c @@ -0,0 +1,575 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* 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. + * + * 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 *net, struct sctp_bind_addr *dest, + union sctp_addr *addr, enum sctp_scope 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, + enum sctp_scope 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; + } + } + + /* If somehow no addresses were found that can be used with this + * scope, it's an error. + */ + if (list_empty(&dest->address_list)) + error = -ENETUNREACH; + +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) || + !af->from_addr_param(&addr, rawaddr, htons(port), 0)) { + retval = -EINVAL; + goto out_err; + } + + 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. */ + goto out_err; + +next: + len = ntohs(param->length); + addrs_len -= len; + raw_addr_list += len; + } + + return retval; + +out_err: + if (retval) + sctp_bind_addr_clean(bp); + + 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; +} + +int sctp_bind_addrs_check(struct sctp_sock *sp, + struct sctp_sock *sp2, int cnt2) +{ + struct sctp_bind_addr *bp2 = &sp2->ep->base.bind_addr; + struct sctp_bind_addr *bp = &sp->ep->base.bind_addr; + struct sctp_sockaddr_entry *laddr, *laddr2; + bool exist = false; + int cnt = 0; + + rcu_read_lock(); + list_for_each_entry_rcu(laddr, &bp->address_list, list) { + list_for_each_entry_rcu(laddr2, &bp2->address_list, list) { + if (sp->pf->af->cmp_addr(&laddr->a, &laddr2->a) && + laddr->valid && laddr2->valid) { + exist = true; + goto next; + } + } + cnt = 0; + break; +next: + cnt++; + } + rcu_read_unlock(); + + return (cnt == cnt2) ? 0 : (exist ? -EEXIST : 1); +} + +/* 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; + + af = sctp_get_af_specific(addr->sa.sa_family); + if (unlikely(!af)) + return -1; + + list_for_each_entry_rcu(laddr, &bp->address_list, list) { + if (!laddr->valid) + continue; + if (af->cmp_addr(&laddr->a, addr)) + return laddr->state; + } + + return -1; +} + +/* 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, enum sctp_scope 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_ALLOWED) && + (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, + enum sctp_scope scope) +{ + enum sctp_scope 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 + * 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'? */ +enum sctp_scope 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); +} |