// 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"
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;
}
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