linuxdebug/net/sctp/bind_addr.c

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2024-07-16 15:50:57 +02:00
// 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);
}