[linux-2.6-block.git] / fs / afs / addr_list.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* Server address list management
 *
 * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/dns_resolver.h>
#include <linux/inet.h>
#include <keys/rxrpc-type.h>
#include "internal.h"
#include "afs_fs.h"

static void afs_free_addrlist(struct rcu_head *rcu)
{
	struct afs_addr_list *alist = container_of(rcu, struct afs_addr_list, rcu);
	unsigned int i;

	for (i = 0; i < alist->nr_addrs; i++)
		rxrpc_kernel_put_peer(alist->addrs[i].peer);
	trace_afs_alist(alist->debug_id, refcount_read(&alist->usage), afs_alist_trace_free);
	kfree(alist);
}

/*
 * Release an address list.
 */
void afs_put_addrlist(struct afs_addr_list *alist, enum afs_alist_trace reason)
{
	unsigned int debug_id;
	bool dead;
	int r;

	if (!alist)
		return;
	debug_id = alist->debug_id;
	dead = __refcount_dec_and_test(&alist->usage, &r);
	trace_afs_alist(debug_id, r - 1, reason);
	if (dead)
		call_rcu(&alist->rcu, afs_free_addrlist);
}

struct afs_addr_list *afs_get_addrlist(struct afs_addr_list *alist, enum afs_alist_trace reason)
{
	int r;

	if (alist) {
		__refcount_inc(&alist->usage, &r);
		trace_afs_alist(alist->debug_id, r + 1, reason);
	}
	return alist;
}

/*
 * Allocate an address list.
 */
struct afs_addr_list *afs_alloc_addrlist(unsigned int nr)
{
	struct afs_addr_list *alist;
	static atomic_t debug_id;

	_enter("%u", nr);

	if (nr > AFS_MAX_ADDRESSES)
		nr = AFS_MAX_ADDRESSES;

	alist = kzalloc(struct_size(alist, addrs, nr), GFP_KERNEL);
	if (!alist)
		return NULL;

	refcount_set(&alist->usage, 1);
	alist->max_addrs = nr;
	alist->debug_id = atomic_inc_return(&debug_id);
	trace_afs_alist(alist->debug_id, 1, afs_alist_trace_alloc);
	return alist;
}

/*
 * Parse a text string consisting of delimited addresses.
 */
struct afs_vlserver_list *afs_parse_text_addrs(struct afs_net *net,
					       const char *text, size_t len,
					       char delim,
					       unsigned short service,
					       unsigned short port)
{
	struct afs_vlserver_list *vllist;
	struct afs_addr_list *alist;
	const char *p, *end = text + len;
	const char *problem;
	unsigned int nr = 0;
	int ret = -ENOMEM;

	_enter("%*.*s,%c", (int)len, (int)len, text, delim);

	if (!len) {
		_leave(" = -EDESTADDRREQ [empty]");
		return ERR_PTR(-EDESTADDRREQ);
	}

	if (delim == ':' && (memchr(text, ',', len) || !memchr(text, '.', len)))
		delim = ',';

	/* Count the addresses */
	p = text;
	do {
		if (!*p) {
			problem = "nul";
			goto inval;
		}
		if (*p == delim)
			continue;
		nr++;
		if (*p == '[') {
			p++;
			if (p == end) {
				problem = "brace1";
				goto inval;
			}
			p = memchr(p, ']', end - p);
			if (!p) {
				problem = "brace2";
				goto inval;
			}
			p++;
			if (p >= end)
				break;
		}

		p = memchr(p, delim, end - p);
		if (!p)
			break;
		p++;
	} while (p < end);

	_debug("%u/%u addresses", nr, AFS_MAX_ADDRESSES);

	vllist = afs_alloc_vlserver_list(1);
	if (!vllist)
		return ERR_PTR(-ENOMEM);

	vllist->nr_servers = 1;
	vllist->servers[0].server = afs_alloc_vlserver("<dummy>", 7, AFS_VL_PORT);
	if (!vllist->servers[0].server)
		goto error_vl;

	alist = afs_alloc_addrlist(nr);
	if (!alist)
		goto error;

	/* Extract the addresses */
	p = text;
	do {
		const char *q, *stop;
		unsigned int xport = port;
		__be32 x[4];
		int family;

		if (*p == delim) {
			p++;
			continue;
		}

		if (*p == '[') {
			p++;
			q = memchr(p, ']', end - p);
		} else {
			for (q = p; q < end; q++)
				if (*q == '+' || *q == delim)
					break;
		}

		if (in4_pton(p, q - p, (u8 *)&x[0], -1, &stop)) {
			family = AF_INET;
		} else if (in6_pton(p, q - p, (u8 *)x, -1, &stop)) {
			family = AF_INET6;
		} else {
			problem = "family";
			goto bad_address;
		}

		p = q;
		if (stop != p) {
			problem = "nostop";
			goto bad_address;
		}

		if (q < end && *q == ']')
			p++;

		if (p < end) {
			if (*p == '+') {
				/* Port number specification "+1234" */
				xport = 0;
				p++;
				if (p >= end || !isdigit(*p)) {
					problem = "port";
					goto bad_address;
				}
				do {
					xport *= 10;
					xport += *p - '0';
					if (xport > 65535) {
						problem = "pval";
						goto bad_address;
					}
					p++;
				} while (p < end && isdigit(*p));
			} else if (*p == delim) {
				p++;
			} else {
				problem = "weird";
				goto bad_address;
			}
		}

		if (family == AF_INET)
			ret = afs_merge_fs_addr4(net, alist, x[0], xport);
		else
			ret = afs_merge_fs_addr6(net, alist, x, xport);
		if (ret < 0)
			goto error;

	} while (p < end);

	rcu_assign_pointer(vllist->servers[0].server->addresses, alist);
	_leave(" = [nr %u]", alist->nr_addrs);
	return vllist;

inval:
	_leave(" = -EINVAL [%s %zu %*.*s]",
	       problem, p - text, (int)len, (int)len, text);
	return ERR_PTR(-EINVAL);
bad_address:
	_leave(" = -EINVAL [%s %zu %*.*s]",
	       problem, p - text, (int)len, (int)len, text);
	ret = -EINVAL;
error:
	afs_put_addrlist(alist, afs_alist_trace_put_parse_error);
error_vl:
	afs_put_vlserverlist(net, vllist);
	return ERR_PTR(ret);
}

/*
 * Perform a DNS query for VL servers and build a up an address list.
 */
struct afs_vlserver_list *afs_dns_query(struct afs_cell *cell, time64_t *_expiry)
{
	struct afs_vlserver_list *vllist;
	char *result = NULL;
	int ret;

	_enter("%s", cell->name);

	ret = dns_query(cell->net->net, "afsdb", cell->name, cell->name_len,
			"srv=1", &result, _expiry, true);
	if (ret < 0) {
		_leave(" = %d [dns]", ret);
		return ERR_PTR(ret);
	}

	if (*_expiry == 0)
		*_expiry = ktime_get_real_seconds() + 60;

	if (ret > 1 && result[0] == 0)
		vllist = afs_extract_vlserver_list(cell, result, ret);
	else
		vllist = afs_parse_text_addrs(cell->net, result, ret, ',',
					      VL_SERVICE, AFS_VL_PORT);
	kfree(result);
	if (IS_ERR(vllist) && vllist != ERR_PTR(-ENOMEM))
		pr_err("Failed to parse DNS data %ld\n", PTR_ERR(vllist));

	return vllist;
}

/*
 * Merge an IPv4 entry into a fileserver address list.
 */
int afs_merge_fs_addr4(struct afs_net *net, struct afs_addr_list *alist,
		       __be32 xdr, u16 port)
{
	struct sockaddr_rxrpc srx;
	struct rxrpc_peer *peer;
	int i;

	if (alist->nr_addrs >= alist->max_addrs)
		return 0;

	srx.srx_family = AF_RXRPC;
	srx.transport_type = SOCK_DGRAM;
	srx.transport_len = sizeof(srx.transport.sin);
	srx.transport.sin.sin_family = AF_INET;
	srx.transport.sin.sin_port = htons(port);
	srx.transport.sin.sin_addr.s_addr = xdr;

	peer = rxrpc_kernel_lookup_peer(net->socket, &srx, GFP_KERNEL);
	if (!peer)
		return -ENOMEM;

	for (i = 0; i < alist->nr_ipv4; i++) {
		if (peer == alist->addrs[i].peer) {
			rxrpc_kernel_put_peer(peer);
			return 0;
		}
		if (peer <= alist->addrs[i].peer)
			break;
	}

	if (i < alist->nr_addrs)
		memmove(alist->addrs + i + 1,
			alist->addrs + i,
			sizeof(alist->addrs[0]) * (alist->nr_addrs - i));

	alist->addrs[i].peer = peer;
	alist->nr_ipv4++;
	alist->nr_addrs++;
	return 0;
}

/*
 * Merge an IPv6 entry into a fileserver address list.
 */
int afs_merge_fs_addr6(struct afs_net *net, struct afs_addr_list *alist,
		       __be32 *xdr, u16 port)
{
	struct sockaddr_rxrpc srx;
	struct rxrpc_peer *peer;
	int i;

	if (alist->nr_addrs >= alist->max_addrs)
		return 0;

	srx.srx_family = AF_RXRPC;
	srx.transport_type = SOCK_DGRAM;
	srx.transport_len = sizeof(srx.transport.sin6);
	srx.transport.sin6.sin6_family = AF_INET6;
	srx.transport.sin6.sin6_port = htons(port);
	memcpy(&srx.transport.sin6.sin6_addr, xdr, 16);

	peer = rxrpc_kernel_lookup_peer(net->socket, &srx, GFP_KERNEL);
	if (!peer)
		return -ENOMEM;

	for (i = alist->nr_ipv4; i < alist->nr_addrs; i++) {
		if (peer == alist->addrs[i].peer) {
			rxrpc_kernel_put_peer(peer);
			return 0;
		}
		if (peer <= alist->addrs[i].peer)
			break;
	}

	if (i < alist->nr_addrs)
		memmove(alist->addrs + i + 1,
			alist->addrs + i,
			sizeof(alist->addrs[0]) * (alist->nr_addrs - i));
	alist->addrs[i].peer = peer;
	alist->nr_addrs++;
	return 0;
}
Commit	Line	Data
b4d0d230	1	// SPDX-License-Identifier: GPL-2.0-or-later
8b2a464c DH	2	/* Server address list management
	3	*
	4	* Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
	5	* Written by David Howells (dhowells@redhat.com)
8b2a464c DH	6	*/
	7
	8	#include <linux/slab.h>
	9	#include <linux/ctype.h>
	10	#include <linux/dns_resolver.h>
	11	#include <linux/inet.h>
	12	#include <keys/rxrpc-type.h>
	13	#include "internal.h"
	14	#include "afs_fs.h"
	15
72904d7b DH	16	static void afs_free_addrlist(struct rcu_head *rcu)
	17	{
	18	struct afs_addr_list *alist = container_of(rcu, struct afs_addr_list, rcu);
	19	unsigned int i;
	20
	21	for (i = 0; i < alist->nr_addrs; i++)
	22	rxrpc_kernel_put_peer(alist->addrs[i].peer);
1e5d8493 DH	23	trace_afs_alist(alist->debug_id, refcount_read(&alist->usage), afs_alist_trace_free);
1e5d8493 DH	24	kfree(alist);
72904d7b DH	25	}
72904d7b DH	26
8b2a464c DH	27	/*
	28	* Release an address list.
	29	*/
1e5d8493	30	void afs_put_addrlist(struct afs_addr_list *alist, enum afs_alist_trace reason)
8b2a464c	31	{
1e5d8493 DH	32	unsigned int debug_id;
	33	bool dead;
	34	int r;
	35
	36	if (!alist)
	37	return;
	38	debug_id = alist->debug_id;
	39	dead = __refcount_dec_and_test(&alist->usage, &r);
	40	trace_afs_alist(debug_id, r - 1, reason);
	41	if (dead)
72904d7b	42	call_rcu(&alist->rcu, afs_free_addrlist);
8b2a464c DH	43	}
8b2a464c DH	44
1e5d8493 DH	45	struct afs_addr_list afs_get_addrlist(struct afs_addr_list alist, enum afs_alist_trace reason)
	46	{
	47	int r;
	48
	49	if (alist) {
	50	__refcount_inc(&alist->usage, &r);
	51	trace_afs_alist(alist->debug_id, r + 1, reason);
	52	}
	53	return alist;
	54	}
	55
8b2a464c DH	56	/*
	57	* Allocate an address list.
	58	*/
e38f299e	59	struct afs_addr_list *afs_alloc_addrlist(unsigned int nr)
8b2a464c DH	60	{
8b2a464c DH	61	struct afs_addr_list *alist;
1e5d8493	62	static atomic_t debug_id;
8b2a464c	63
e38f299e	64	_enter("%u", nr);
8b2a464c	65
68eb64c3 DH	66	if (nr > AFS_MAX_ADDRESSES)
	67	nr = AFS_MAX_ADDRESSES;
	68
acafe7e3	69	alist = kzalloc(struct_size(alist, addrs, nr), GFP_KERNEL);
8b2a464c DH	70	if (!alist)
	71	return NULL;
	72
	73	refcount_set(&alist->usage, 1);
68eb64c3	74	alist->max_addrs = nr;
1e5d8493	75	alist->debug_id = atomic_inc_return(&debug_id);
1e5d8493	76	trace_afs_alist(alist->debug_id, 1, afs_alist_trace_alloc);
8b2a464c DH	77	return alist;
	78	}
	79
	80	/*
	81	* Parse a text string consisting of delimited addresses.
	82	*/
0a5143f2 DH	83	struct afs_vlserver_list afs_parse_text_addrs(struct afs_net net,
	84	const char *text, size_t len,
	85	char delim,
	86	unsigned short service,
	87	unsigned short port)
8b2a464c	88	{
0a5143f2	89	struct afs_vlserver_list *vllist;
8b2a464c DH	90	struct afs_addr_list *alist;
8b2a464c DH	91	const char p, end = text + len;
0a5143f2	92	const char *problem;
8b2a464c	93	unsigned int nr = 0;
0a5143f2	94	int ret = -ENOMEM;
8b2a464c DH	95
	96	_enter("%.s,%c", (int)len, (int)len, text, delim);
	97
0a5143f2 DH	98	if (!len) {
0a5143f2 DH	99	_leave(" = -EDESTADDRREQ [empty]");
8b2a464c	100	return ERR_PTR(-EDESTADDRREQ);
0a5143f2	101	}
8b2a464c DH	102
	103	if (delim == ':' && (memchr(text, ',', len) \|\| !memchr(text, '.', len)))
	104	delim = ',';
	105
	106	/* Count the addresses */
	107	p = text;
	108	do {
0a5143f2 DH	109	if (!*p) {
	110	problem = "nul";
	111	goto inval;
	112	}
8b2a464c DH	113	if (*p == delim)
	114	continue;
	115	nr++;
	116	if (*p == '[') {
	117	p++;
0a5143f2 DH	118	if (p == end) {
	119	problem = "brace1";
	120	goto inval;
	121	}
8b2a464c	122	p = memchr(p, ']', end - p);
0a5143f2 DH	123	if (!p) {
	124	problem = "brace2";
	125	goto inval;
	126	}
8b2a464c DH	127	p++;
	128	if (p >= end)
	129	break;
	130	}
	131
	132	p = memchr(p, delim, end - p);
	133	if (!p)
	134	break;
	135	p++;
	136	} while (p < end);
	137
	138	_debug("%u/%u addresses", nr, AFS_MAX_ADDRESSES);
8b2a464c	139
0a5143f2 DH	140	vllist = afs_alloc_vlserver_list(1);
0a5143f2 DH	141	if (!vllist)
8b2a464c DH	142	return ERR_PTR(-ENOMEM);
8b2a464c DH	143
0a5143f2 DH	144	vllist->nr_servers = 1;
	145	vllist->servers[0].server = afs_alloc_vlserver("<dummy>", 7, AFS_VL_PORT);
	146	if (!vllist->servers[0].server)
	147	goto error_vl;
	148
e38f299e	149	alist = afs_alloc_addrlist(nr);
0a5143f2 DH	150	if (!alist)
	151	goto error;
	152
8b2a464c DH	153	/* Extract the addresses */
	154	p = text;
	155	do {
01fd79e6	156	const char q, stop;
4c19bbdc DH	157	unsigned int xport = port;
	158	__be32 x[4];
	159	int family;
8b2a464c DH	160
	161	if (*p == delim) {
	162	p++;
	163	continue;
	164	}
	165
	166	if (*p == '[') {
	167	p++;
01fd79e6 DH	168	q = memchr(p, ']', end - p);
	169	} else {
	170	for (q = p; q < end; q++)
	171	if (q == '+' \|\| q == delim)
	172	break;
8b2a464c DH	173	}
8b2a464c DH	174
0a5143f2	175	if (in4_pton(p, q - p, (u8 *)&x[0], -1, &stop)) {
4c19bbdc	176	family = AF_INET;
0a5143f2	177	} else if (in6_pton(p, q - p, (u8 *)x, -1, &stop)) {
4c19bbdc	178	family = AF_INET6;
0a5143f2 DH	179	} else {
0a5143f2 DH	180	problem = "family";
8b2a464c	181	goto bad_address;
0a5143f2	182	}
8b2a464c	183
0a5143f2 DH	184	p = q;
	185	if (stop != p) {
	186	problem = "nostop";
01fd79e6	187	goto bad_address;
0a5143f2	188	}
01fd79e6	189
01fd79e6	190	if (q < end && *q == ']')
8b2a464c	191	p++;
8b2a464c DH	192
	193	if (p < end) {
	194	if (*p == '+') {
	195	/* Port number specification "+1234" */
4c19bbdc	196	xport = 0;
8b2a464c	197	p++;
0a5143f2 DH	198	if (p >= end \|\| !isdigit(*p)) {
0a5143f2 DH	199	problem = "port";
8b2a464c	200	goto bad_address;
0a5143f2	201	}
8b2a464c DH	202	do {
	203	xport *= 10;
	204	xport += *p - '0';
0a5143f2 DH	205	if (xport > 65535) {
0a5143f2 DH	206	problem = "pval";
8b2a464c	207	goto bad_address;
0a5143f2	208	}
8b2a464c DH	209	p++;
8b2a464c DH	210	} while (p < end && isdigit(*p));
8b2a464c DH	211	} else if (*p == delim) {
	212	p++;
	213	} else {
0a5143f2	214	problem = "weird";
8b2a464c DH	215	goto bad_address;
	216	}
	217	}
	218
4c19bbdc	219	if (family == AF_INET)
72904d7b	220	ret = afs_merge_fs_addr4(net, alist, x[0], xport);
4c19bbdc	221	else
72904d7b DH	222	ret = afs_merge_fs_addr6(net, alist, x, xport);
	223	if (ret < 0)
	224	goto error;
4c19bbdc DH	225
4c19bbdc DH	226	} while (p < end);
8b2a464c	227
0a5143f2	228	rcu_assign_pointer(vllist->servers[0].server->addresses, alist);
8b2a464c	229	_leave(" = [nr %u]", alist->nr_addrs);
0a5143f2	230	return vllist;
8b2a464c	231
0a5143f2 DH	232	inval:
	233	_leave(" = -EINVAL [%s %zu %.s]",
	234	problem, p - text, (int)len, (int)len, text);
8b2a464c	235	return ERR_PTR(-EINVAL);
0a5143f2 DH	236	bad_address:
	237	_leave(" = -EINVAL [%s %zu %.s]",
	238	problem, p - text, (int)len, (int)len, text);
	239	ret = -EINVAL;
	240	error:
1e5d8493	241	afs_put_addrlist(alist, afs_alist_trace_put_parse_error);
0a5143f2 DH	242	error_vl:
	243	afs_put_vlserverlist(net, vllist);
	244	return ERR_PTR(ret);
8b2a464c DH	245	}
8b2a464c DH	246
8b2a464c DH	247	/*
	248	* Perform a DNS query for VL servers and build a up an address list.
	249	*/
0a5143f2	250	struct afs_vlserver_list afs_dns_query(struct afs_cell cell, time64_t *_expiry)
8b2a464c	251	{
0a5143f2 DH	252	struct afs_vlserver_list *vllist;
0a5143f2 DH	253	char *result = NULL;
8b2a464c DH	254	int ret;
	255
	256	_enter("%s", cell->name);
	257
a58946c1 DH	258	ret = dns_query(cell->net->net, "afsdb", cell->name, cell->name_len,
a58946c1 DH	259	"srv=1", &result, _expiry, true);
0a5143f2 DH	260	if (ret < 0) {
0a5143f2 DH	261	_leave(" = %d [dns]", ret);
8b2a464c	262	return ERR_PTR(ret);
8b2a464c DH	263	}
8b2a464c DH	264
0a5143f2 DH	265	if (*_expiry == 0)
	266	*_expiry = ktime_get_real_seconds() + 60;
	267
	268	if (ret > 1 && result[0] == 0)
	269	vllist = afs_extract_vlserver_list(cell, result, ret);
	270	else
	271	vllist = afs_parse_text_addrs(cell->net, result, ret, ',',
	272	VL_SERVICE, AFS_VL_PORT);
	273	kfree(result);
	274	if (IS_ERR(vllist) && vllist != ERR_PTR(-ENOMEM))
	275	pr_err("Failed to parse DNS data %ld\n", PTR_ERR(vllist));
	276
	277	return vllist;
8b2a464c DH	278	}
8b2a464c DH	279
d2ddc776 DH	280	/*
	281	* Merge an IPv4 entry into a fileserver address list.
	282	*/
72904d7b DH	283	int afs_merge_fs_addr4(struct afs_net net, struct afs_addr_list alist,
72904d7b DH	284	__be32 xdr, u16 port)
d2ddc776	285	{
72904d7b DH	286	struct sockaddr_rxrpc srx;
72904d7b DH	287	struct rxrpc_peer *peer;
d2ddc776 DH	288	int i;
d2ddc776 DH	289
68eb64c3	290	if (alist->nr_addrs >= alist->max_addrs)
72904d7b	291	return 0;
68eb64c3	292
72904d7b DH	293	srx.srx_family = AF_RXRPC;
	294	srx.transport_type = SOCK_DGRAM;
	295	srx.transport_len = sizeof(srx.transport.sin);
	296	srx.transport.sin.sin_family = AF_INET;
	297	srx.transport.sin.sin_port = htons(port);
	298	srx.transport.sin.sin_addr.s_addr = xdr;
66be646b	299
72904d7b DH	300	peer = rxrpc_kernel_lookup_peer(net->socket, &srx, GFP_KERNEL);
	301	if (!peer)
	302	return -ENOMEM;
	303
	304	for (i = 0; i < alist->nr_ipv4; i++) {
	305	if (peer == alist->addrs[i].peer) {
	306	rxrpc_kernel_put_peer(peer);
	307	return 0;
	308	}
	309	if (peer <= alist->addrs[i].peer)
d2ddc776 DH	310	break;
	311	}
	312
	313	if (i < alist->nr_addrs)
	314	memmove(alist->addrs + i + 1,
	315	alist->addrs + i,
	316	sizeof(alist->addrs[0]) * (alist->nr_addrs - i));
	317
72904d7b	318	alist->addrs[i].peer = peer;
d2ddc776 DH	319	alist->nr_ipv4++;
d2ddc776 DH	320	alist->nr_addrs++;
72904d7b	321	return 0;
d2ddc776 DH	322	}
d2ddc776 DH	323
bf99a53c DH	324	/*
	325	* Merge an IPv6 entry into a fileserver address list.
	326	*/
72904d7b DH	327	int afs_merge_fs_addr6(struct afs_net net, struct afs_addr_list alist,
72904d7b DH	328	__be32 *xdr, u16 port)
bf99a53c	329	{
72904d7b DH	330	struct sockaddr_rxrpc srx;
	331	struct rxrpc_peer *peer;
	332	int i;
bf99a53c	333
68eb64c3	334	if (alist->nr_addrs >= alist->max_addrs)
72904d7b	335	return 0;
68eb64c3	336
72904d7b DH	337	srx.srx_family = AF_RXRPC;
	338	srx.transport_type = SOCK_DGRAM;
	339	srx.transport_len = sizeof(srx.transport.sin6);
	340	srx.transport.sin6.sin6_family = AF_INET6;
	341	srx.transport.sin6.sin6_port = htons(port);
	342	memcpy(&srx.transport.sin6.sin6_addr, xdr, 16);
66be646b	343
72904d7b DH	344	peer = rxrpc_kernel_lookup_peer(net->socket, &srx, GFP_KERNEL);
	345	if (!peer)
	346	return -ENOMEM;
	347
	348	for (i = alist->nr_ipv4; i < alist->nr_addrs; i++) {
	349	if (peer == alist->addrs[i].peer) {
	350	rxrpc_kernel_put_peer(peer);
	351	return 0;
	352	}
	353	if (peer <= alist->addrs[i].peer)
bf99a53c DH	354	break;
	355	}
	356
	357	if (i < alist->nr_addrs)
	358	memmove(alist->addrs + i + 1,
	359	alist->addrs + i,
	360	sizeof(alist->addrs[0]) * (alist->nr_addrs - i));
72904d7b	361	alist->addrs[i].peer = peer;
bf99a53c	362	alist->nr_addrs++;
72904d7b	363	return 0;
bf99a53c	364	}