[linux.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 ([email protected])
 */

#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"

/*
 * Release an address list.
 */
void afs_put_addrlist(struct afs_addr_list *alist)
{
	if (alist && refcount_dec_and_test(&alist->usage))
		kfree_rcu(alist, rcu);
}

/*
 * Allocate an address list.
 */
struct afs_addr_list *afs_alloc_addrlist(unsigned int nr,
					 unsigned short service,
					 unsigned short port)
{
	struct afs_addr_list *alist;
	unsigned int i;

	_enter("%u,%u,%u", nr, service, port);

	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;

	for (i = 0; i < nr; i++) {
		struct sockaddr_rxrpc *srx = &alist->addrs[i];
		srx->srx_family			= AF_RXRPC;
		srx->srx_service		= service;
		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);
	}

	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, service, AFS_VL_PORT);
	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)
			afs_merge_fs_addr4(alist, x[0], xport);
		else
			afs_merge_fs_addr6(alist, x, xport);

	} 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);
error_vl:
	afs_put_vlserverlist(net, vllist);
	return ERR_PTR(ret);
}

/*
 * Compare old and new address lists to see if there's been any change.
 * - How to do this in better than O(Nlog(N)) time?
 *   - We don't really want to sort the address list, but would rather take the
 *     list as we got it so as not to undo record rotation by the DNS server.
 */
#if 0
static int afs_cmp_addr_list(const struct afs_addr_list *a1,
			     const struct afs_addr_list *a2)
{
}
#endif

/*
 * 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.
 */
void afs_merge_fs_addr4(struct afs_addr_list *alist, __be32 xdr, u16 port)
{
	struct sockaddr_rxrpc *srx;
	u32 addr = ntohl(xdr);
	int i;

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

	for (i = 0; i < alist->nr_ipv4; i++) {
		struct sockaddr_in *a = &alist->addrs[i].transport.sin;
		u32 a_addr = ntohl(a->sin_addr.s_addr);
		u16 a_port = ntohs(a->sin_port);

		if (addr == a_addr && port == a_port)
			return;
		if (addr == a_addr && port < a_port)
			break;
		if (addr < a_addr)
			break;
	}

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

	srx = &alist->addrs[i];
	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;
	alist->nr_ipv4++;
	alist->nr_addrs++;
}

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

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

	for (i = alist->nr_ipv4; i < alist->nr_addrs; i++) {
		struct sockaddr_in6 *a = &alist->addrs[i].transport.sin6;
		u16 a_port = ntohs(a->sin6_port);

		diff = memcmp(xdr, &a->sin6_addr, 16);
		if (diff == 0 && port == a_port)
			return;
		if (diff == 0 && port < a_port)
			break;
		if (diff < 0)
			break;
	}

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

	srx = &alist->addrs[i];
	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);
	alist->nr_addrs++;
}

/*
 * Get an address to try.
 */
bool afs_iterate_addresses(struct afs_addr_cursor *ac)
{
	unsigned long set, failed;
	int index;

	if (!ac->alist)
		return false;

	set = ac->alist->responded;
	failed = ac->alist->failed;
	_enter("%lx-%lx-%lx,%d", set, failed, ac->tried, ac->index);

	ac->nr_iterations++;

	set &= ~(failed | ac->tried);

	if (!set)
		return false;

	index = READ_ONCE(ac->alist->preferred);
	if (test_bit(index, &set))
		goto selected;

	index = __ffs(set);

selected:
	ac->index = index;
	set_bit(index, &ac->tried);
	ac->responded = false;
	return true;
}

/*
 * Release an address list cursor.
 */
int afs_end_cursor(struct afs_addr_cursor *ac)
{
	struct afs_addr_list *alist;

	alist = ac->alist;
	if (alist) {
		if (ac->responded &&
		    ac->index != alist->preferred &&
		    test_bit(ac->alist->preferred, &ac->tried))
			WRITE_ONCE(alist->preferred, ac->index);
		afs_put_addrlist(alist);
		ac->alist = NULL;
	}

	return ac->error;
}
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 ([email protected])
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
8b2a464c DH	16	/*
	17	* Release an address list.
	18	*/
	19	void afs_put_addrlist(struct afs_addr_list *alist)
	20	{
	21	if (alist && refcount_dec_and_test(&alist->usage))
ddd2b85f	22	kfree_rcu(alist, rcu);
8b2a464c DH	23	}
	24
	25	/*
	26	* Allocate an address list.
	27	*/
	28	struct afs_addr_list *afs_alloc_addrlist(unsigned int nr,
	29	unsigned short service,
	30	unsigned short port)
	31	{
	32	struct afs_addr_list *alist;
	33	unsigned int i;
	34
	35	_enter("%u,%u,%u", nr, service, port);
	36
68eb64c3 DH	37	if (nr > AFS_MAX_ADDRESSES)
	38	nr = AFS_MAX_ADDRESSES;
	39
acafe7e3	40	alist = kzalloc(struct_size(alist, addrs, nr), GFP_KERNEL);
8b2a464c DH	41	if (!alist)
	42	return NULL;
	43
	44	refcount_set(&alist->usage, 1);
68eb64c3	45	alist->max_addrs = nr;
8b2a464c DH	46
	47	for (i = 0; i < nr; i++) {
	48	struct sockaddr_rxrpc *srx = &alist->addrs[i];
	49	srx->srx_family = AF_RXRPC;
	50	srx->srx_service = service;
	51	srx->transport_type = SOCK_DGRAM;
	52	srx->transport_len = sizeof(srx->transport.sin6);
	53	srx->transport.sin6.sin6_family = AF_INET6;
	54	srx->transport.sin6.sin6_port = htons(port);
	55	}
	56
	57	return alist;
	58	}
	59
	60	/*
	61	* Parse a text string consisting of delimited addresses.
	62	*/
0a5143f2 DH	63	struct afs_vlserver_list afs_parse_text_addrs(struct afs_net net,
	64	const char *text, size_t len,
	65	char delim,
	66	unsigned short service,
	67	unsigned short port)
8b2a464c	68	{
0a5143f2	69	struct afs_vlserver_list *vllist;
8b2a464c DH	70	struct afs_addr_list *alist;
8b2a464c DH	71	const char p, end = text + len;
0a5143f2	72	const char *problem;
8b2a464c	73	unsigned int nr = 0;
0a5143f2	74	int ret = -ENOMEM;
8b2a464c DH	75
	76	_enter("%.s,%c", (int)len, (int)len, text, delim);
	77
0a5143f2 DH	78	if (!len) {
0a5143f2 DH	79	_leave(" = -EDESTADDRREQ [empty]");
8b2a464c	80	return ERR_PTR(-EDESTADDRREQ);
0a5143f2	81	}
8b2a464c DH	82
	83	if (delim == ':' && (memchr(text, ',', len) \|\| !memchr(text, '.', len)))
	84	delim = ',';
	85
	86	/* Count the addresses */
	87	p = text;
	88	do {
0a5143f2 DH	89	if (!*p) {
	90	problem = "nul";
	91	goto inval;
	92	}
8b2a464c DH	93	if (*p == delim)
	94	continue;
	95	nr++;
	96	if (*p == '[') {
	97	p++;
0a5143f2 DH	98	if (p == end) {
	99	problem = "brace1";
	100	goto inval;
	101	}
8b2a464c	102	p = memchr(p, ']', end - p);
0a5143f2 DH	103	if (!p) {
	104	problem = "brace2";
	105	goto inval;
	106	}
8b2a464c DH	107	p++;
	108	if (p >= end)
	109	break;
	110	}
	111
	112	p = memchr(p, delim, end - p);
	113	if (!p)
	114	break;
	115	p++;
	116	} while (p < end);
	117
	118	_debug("%u/%u addresses", nr, AFS_MAX_ADDRESSES);
8b2a464c	119
0a5143f2 DH	120	vllist = afs_alloc_vlserver_list(1);
0a5143f2 DH	121	if (!vllist)
8b2a464c DH	122	return ERR_PTR(-ENOMEM);
8b2a464c DH	123
0a5143f2 DH	124	vllist->nr_servers = 1;
	125	vllist->servers[0].server = afs_alloc_vlserver("<dummy>", 7, AFS_VL_PORT);
	126	if (!vllist->servers[0].server)
	127	goto error_vl;
	128
	129	alist = afs_alloc_addrlist(nr, service, AFS_VL_PORT);
	130	if (!alist)
	131	goto error;
	132
8b2a464c DH	133	/* Extract the addresses */
	134	p = text;
	135	do {
01fd79e6	136	const char q, stop;
4c19bbdc DH	137	unsigned int xport = port;
	138	__be32 x[4];
	139	int family;
8b2a464c DH	140
	141	if (*p == delim) {
	142	p++;
	143	continue;
	144	}
	145
	146	if (*p == '[') {
	147	p++;
01fd79e6 DH	148	q = memchr(p, ']', end - p);
	149	} else {
	150	for (q = p; q < end; q++)
	151	if (q == '+' \|\| q == delim)
	152	break;
8b2a464c DH	153	}
8b2a464c DH	154
0a5143f2	155	if (in4_pton(p, q - p, (u8 *)&x[0], -1, &stop)) {
4c19bbdc	156	family = AF_INET;
0a5143f2	157	} else if (in6_pton(p, q - p, (u8 *)x, -1, &stop)) {
4c19bbdc	158	family = AF_INET6;
0a5143f2 DH	159	} else {
0a5143f2 DH	160	problem = "family";
8b2a464c	161	goto bad_address;
0a5143f2	162	}
8b2a464c	163
0a5143f2 DH	164	p = q;
	165	if (stop != p) {
	166	problem = "nostop";
01fd79e6	167	goto bad_address;
0a5143f2	168	}
01fd79e6	169
01fd79e6	170	if (q < end && *q == ']')
8b2a464c	171	p++;
8b2a464c DH	172
	173	if (p < end) {
	174	if (*p == '+') {
	175	/* Port number specification "+1234" */
4c19bbdc	176	xport = 0;
8b2a464c	177	p++;
0a5143f2 DH	178	if (p >= end \|\| !isdigit(*p)) {
0a5143f2 DH	179	problem = "port";
8b2a464c	180	goto bad_address;
0a5143f2	181	}
8b2a464c DH	182	do {
	183	xport *= 10;
	184	xport += *p - '0';
0a5143f2 DH	185	if (xport > 65535) {
0a5143f2 DH	186	problem = "pval";
8b2a464c	187	goto bad_address;
0a5143f2	188	}
8b2a464c DH	189	p++;
8b2a464c DH	190	} while (p < end && isdigit(*p));
8b2a464c DH	191	} else if (*p == delim) {
	192	p++;
	193	} else {
0a5143f2	194	problem = "weird";
8b2a464c DH	195	goto bad_address;
	196	}
	197	}
	198
4c19bbdc DH	199	if (family == AF_INET)
	200	afs_merge_fs_addr4(alist, x[0], xport);
	201	else
	202	afs_merge_fs_addr6(alist, x, xport);
	203
	204	} while (p < end);
8b2a464c	205
0a5143f2	206	rcu_assign_pointer(vllist->servers[0].server->addresses, alist);
8b2a464c	207	_leave(" = [nr %u]", alist->nr_addrs);
0a5143f2	208	return vllist;
8b2a464c	209
0a5143f2 DH	210	inval:
	211	_leave(" = -EINVAL [%s %zu %.s]",
	212	problem, p - text, (int)len, (int)len, text);
8b2a464c	213	return ERR_PTR(-EINVAL);
0a5143f2 DH	214	bad_address:
	215	_leave(" = -EINVAL [%s %zu %.s]",
	216	problem, p - text, (int)len, (int)len, text);
	217	ret = -EINVAL;
	218	error:
	219	afs_put_addrlist(alist);
	220	error_vl:
	221	afs_put_vlserverlist(net, vllist);
	222	return ERR_PTR(ret);
8b2a464c DH	223	}
	224
	225	/*
	226	* Compare old and new address lists to see if there's been any change.
	227	* - How to do this in better than O(Nlog(N)) time?
	228	* - We don't really want to sort the address list, but would rather take the
	229	* list as we got it so as not to undo record rotation by the DNS server.
	230	*/
	231	#if 0
	232	static int afs_cmp_addr_list(const struct afs_addr_list *a1,
	233	const struct afs_addr_list *a2)
	234	{
	235	}
	236	#endif
	237
	238	/*
	239	* Perform a DNS query for VL servers and build a up an address list.
	240	*/
0a5143f2	241	struct afs_vlserver_list afs_dns_query(struct afs_cell cell, time64_t *_expiry)
8b2a464c	242	{
0a5143f2 DH	243	struct afs_vlserver_list *vllist;
0a5143f2 DH	244	char *result = NULL;
8b2a464c DH	245	int ret;
	246
	247	_enter("%s", cell->name);
	248
a58946c1 DH	249	ret = dns_query(cell->net->net, "afsdb", cell->name, cell->name_len,
a58946c1 DH	250	"srv=1", &result, _expiry, true);
0a5143f2 DH	251	if (ret < 0) {
0a5143f2 DH	252	_leave(" = %d [dns]", ret);
8b2a464c	253	return ERR_PTR(ret);
8b2a464c DH	254	}
8b2a464c DH	255
0a5143f2 DH	256	if (*_expiry == 0)
	257	*_expiry = ktime_get_real_seconds() + 60;
	258
	259	if (ret > 1 && result[0] == 0)
	260	vllist = afs_extract_vlserver_list(cell, result, ret);
	261	else
	262	vllist = afs_parse_text_addrs(cell->net, result, ret, ',',
	263	VL_SERVICE, AFS_VL_PORT);
	264	kfree(result);
	265	if (IS_ERR(vllist) && vllist != ERR_PTR(-ENOMEM))
	266	pr_err("Failed to parse DNS data %ld\n", PTR_ERR(vllist));
	267
	268	return vllist;
8b2a464c DH	269	}
8b2a464c DH	270
d2ddc776 DH	271	/*
	272	* Merge an IPv4 entry into a fileserver address list.
	273	*/
bf99a53c	274	void afs_merge_fs_addr4(struct afs_addr_list *alist, __be32 xdr, u16 port)
d2ddc776	275	{
46894a13	276	struct sockaddr_rxrpc *srx;
66be646b	277	u32 addr = ntohl(xdr);
d2ddc776 DH	278	int i;
d2ddc776 DH	279
68eb64c3 DH	280	if (alist->nr_addrs >= alist->max_addrs)
	281	return;
	282
d2ddc776	283	for (i = 0; i < alist->nr_ipv4; i++) {
46894a13 DH	284	struct sockaddr_in *a = &alist->addrs[i].transport.sin;
	285	u32 a_addr = ntohl(a->sin_addr.s_addr);
	286	u16 a_port = ntohs(a->sin_port);
66be646b DH	287
66be646b DH	288	if (addr == a_addr && port == a_port)
d2ddc776	289	return;
66be646b	290	if (addr == a_addr && port < a_port)
bf99a53c	291	break;
66be646b	292	if (addr < a_addr)
d2ddc776 DH	293	break;
	294	}
	295
	296	if (i < alist->nr_addrs)
	297	memmove(alist->addrs + i + 1,
	298	alist->addrs + i,
	299	sizeof(alist->addrs[0]) * (alist->nr_addrs - i));
	300
46894a13	301	srx = &alist->addrs[i];
3bf0fb6f DH	302	srx->srx_family = AF_RXRPC;
3bf0fb6f DH	303	srx->transport_type = SOCK_DGRAM;
46894a13 DH	304	srx->transport_len = sizeof(srx->transport.sin);
	305	srx->transport.sin.sin_family = AF_INET;
	306	srx->transport.sin.sin_port = htons(port);
	307	srx->transport.sin.sin_addr.s_addr = xdr;
d2ddc776 DH	308	alist->nr_ipv4++;
	309	alist->nr_addrs++;
	310	}
	311
bf99a53c DH	312	/*
	313	* Merge an IPv6 entry into a fileserver address list.
	314	*/
	315	void afs_merge_fs_addr6(struct afs_addr_list alist, __be32 xdr, u16 port)
	316	{
46894a13	317	struct sockaddr_rxrpc *srx;
bf99a53c DH	318	int i, diff;
bf99a53c DH	319
68eb64c3 DH	320	if (alist->nr_addrs >= alist->max_addrs)
	321	return;
	322
bf99a53c	323	for (i = alist->nr_ipv4; i < alist->nr_addrs; i++) {
66be646b DH	324	struct sockaddr_in6 *a = &alist->addrs[i].transport.sin6;
	325	u16 a_port = ntohs(a->sin6_port);
	326
bf99a53c	327	diff = memcmp(xdr, &a->sin6_addr, 16);
66be646b	328	if (diff == 0 && port == a_port)
bf99a53c	329	return;
66be646b	330	if (diff == 0 && port < a_port)
bf99a53c DH	331	break;
	332	if (diff < 0)
	333	break;
	334	}
	335
	336	if (i < alist->nr_addrs)
	337	memmove(alist->addrs + i + 1,
	338	alist->addrs + i,
	339	sizeof(alist->addrs[0]) * (alist->nr_addrs - i));
	340
46894a13	341	srx = &alist->addrs[i];
3bf0fb6f DH	342	srx->srx_family = AF_RXRPC;
3bf0fb6f DH	343	srx->transport_type = SOCK_DGRAM;
46894a13 DH	344	srx->transport_len = sizeof(srx->transport.sin6);
	345	srx->transport.sin6.sin6_family = AF_INET6;
	346	srx->transport.sin6.sin6_port = htons(port);
	347	memcpy(&srx->transport.sin6.sin6_addr, xdr, 16);
bf99a53c DH	348	alist->nr_addrs++;
	349	}
	350
8b2a464c DH	351	/*
	352	* Get an address to try.
	353	*/
	354	bool afs_iterate_addresses(struct afs_addr_cursor *ac)
	355	{
3bf0fb6f DH	356	unsigned long set, failed;
3bf0fb6f DH	357	int index;
8b2a464c DH	358
	359	if (!ac->alist)
	360	return false;
	361
3bf0fb6f DH	362	set = ac->alist->responded;
	363	failed = ac->alist->failed;
	364	_enter("%lx-%lx-%lx,%d", set, failed, ac->tried, ac->index);
	365
744bcd71 DH	366	ac->nr_iterations++;
744bcd71 DH	367
3bf0fb6f	368	set &= ~(failed \| ac->tried);
8b2a464c	369
3bf0fb6f DH	370	if (!set)
	371	return false;
	372
	373	index = READ_ONCE(ac->alist->preferred);
	374	if (test_bit(index, &set))
	375	goto selected;
	376
	377	index = __ffs(set);
8b2a464c	378
3bf0fb6f DH	379	selected:
	380	ac->index = index;
	381	set_bit(index, &ac->tried);
8b2a464c	382	ac->responded = false;
8b2a464c DH	383	return true;
	384	}
	385
	386	/*
	387	* Release an address list cursor.
	388	*/
	389	int afs_end_cursor(struct afs_addr_cursor *ac)
	390	{
fe4d774c DH	391	struct afs_addr_list *alist;
	392
	393	alist = ac->alist;
	394	if (alist) {
3bf0fb6f DH	395	if (ac->responded &&
	396	ac->index != alist->preferred &&
	397	test_bit(ac->alist->preferred, &ac->tried))
	398	WRITE_ONCE(alist->preferred, ac->index);
fe4d774c	399	afs_put_addrlist(alist);
3bf0fb6f	400	ac->alist = NULL;
fe4d774c	401	}
8b2a464c	402
8b2a464c DH	403	return ac->error;
8b2a464c DH	404	}