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1// SPDX-License-Identifier: GPL-2.0-or-later2/* Server address list management3 *4 * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.5 * Written by David Howells (dhowells@redhat.com)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 16static 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);23 trace_afs_alist(alist->debug_id, refcount_read(&alist->usage), afs_alist_trace_free);24 kfree(alist);25}26 27/*28 * Release an address list.29 */30void afs_put_addrlist(struct afs_addr_list *alist, enum afs_alist_trace reason)31{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)42 call_rcu(&alist->rcu, afs_free_addrlist);43}44 45struct 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 56/*57 * Allocate an address list.58 */59struct afs_addr_list *afs_alloc_addrlist(unsigned int nr)60{61 struct afs_addr_list *alist;62 static atomic_t debug_id;63 64 _enter("%u", nr);65 66 if (nr > AFS_MAX_ADDRESSES)67 nr = AFS_MAX_ADDRESSES;68 69 alist = kzalloc(struct_size(alist, addrs, nr), GFP_KERNEL);70 if (!alist)71 return NULL;72 73 refcount_set(&alist->usage, 1);74 alist->max_addrs = nr;75 alist->debug_id = atomic_inc_return(&debug_id);76 trace_afs_alist(alist->debug_id, 1, afs_alist_trace_alloc);77 return alist;78}79 80/*81 * Parse a text string consisting of delimited addresses.82 */83struct 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)88{89 struct afs_vlserver_list *vllist;90 struct afs_addr_list *alist;91 const char *p, *end = text + len;92 const char *problem;93 unsigned int nr = 0;94 int ret = -ENOMEM;95 96 _enter("%*.*s,%c", (int)len, (int)len, text, delim);97 98 if (!len) {99 _leave(" = -EDESTADDRREQ [empty]");100 return ERR_PTR(-EDESTADDRREQ);101 }102 103 if (delim == ':' && (memchr(text, ',', len) || !memchr(text, '.', len)))104 delim = ',';105 106 /* Count the addresses */107 p = text;108 do {109 if (!*p) {110 problem = "nul";111 goto inval;112 }113 if (*p == delim)114 continue;115 nr++;116 if (*p == '[') {117 p++;118 if (p == end) {119 problem = "brace1";120 goto inval;121 }122 p = memchr(p, ']', end - p);123 if (!p) {124 problem = "brace2";125 goto inval;126 }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);139 140 vllist = afs_alloc_vlserver_list(1);141 if (!vllist)142 return ERR_PTR(-ENOMEM);143 144 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;148 149 alist = afs_alloc_addrlist(nr);150 if (!alist)151 goto error;152 153 /* Extract the addresses */154 p = text;155 do {156 const char *q, *stop;157 unsigned int xport = port;158 __be32 x[4];159 int family;160 161 if (*p == delim) {162 p++;163 continue;164 }165 166 if (*p == '[') {167 p++;168 q = memchr(p, ']', end - p);169 } else {170 for (q = p; q < end; q++)171 if (*q == '+' || *q == delim)172 break;173 }174 175 if (in4_pton(p, q - p, (u8 *)&x[0], -1, &stop)) {176 family = AF_INET;177 } else if (in6_pton(p, q - p, (u8 *)x, -1, &stop)) {178 family = AF_INET6;179 } else {180 problem = "family";181 goto bad_address;182 }183 184 p = q;185 if (stop != p) {186 problem = "nostop";187 goto bad_address;188 }189 190 if (q < end && *q == ']')191 p++;192 193 if (p < end) {194 if (*p == '+') {195 /* Port number specification "+1234" */196 xport = 0;197 p++;198 if (p >= end || !isdigit(*p)) {199 problem = "port";200 goto bad_address;201 }202 do {203 xport *= 10;204 xport += *p - '0';205 if (xport > 65535) {206 problem = "pval";207 goto bad_address;208 }209 p++;210 } while (p < end && isdigit(*p));211 } else if (*p == delim) {212 p++;213 } else {214 problem = "weird";215 goto bad_address;216 }217 }218 219 if (family == AF_INET)220 ret = afs_merge_fs_addr4(net, alist, x[0], xport);221 else222 ret = afs_merge_fs_addr6(net, alist, x, xport);223 if (ret < 0)224 goto error;225 226 } while (p < end);227 228 rcu_assign_pointer(vllist->servers[0].server->addresses, alist);229 _leave(" = [nr %u]", alist->nr_addrs);230 return vllist;231 232inval:233 _leave(" = -EINVAL [%s %zu %*.*s]",234 problem, p - text, (int)len, (int)len, text);235 return ERR_PTR(-EINVAL);236bad_address:237 _leave(" = -EINVAL [%s %zu %*.*s]",238 problem, p - text, (int)len, (int)len, text);239 ret = -EINVAL;240error:241 afs_put_addrlist(alist, afs_alist_trace_put_parse_error);242error_vl:243 afs_put_vlserverlist(net, vllist);244 return ERR_PTR(ret);245}246 247/*248 * Perform a DNS query for VL servers and build a up an address list.249 */250struct afs_vlserver_list *afs_dns_query(struct afs_cell *cell, time64_t *_expiry)251{252 struct afs_vlserver_list *vllist;253 char *result = NULL;254 int ret;255 256 _enter("%s", cell->name);257 258 ret = dns_query(cell->net->net, "afsdb", cell->name, cell->name_len,259 "srv=1", &result, _expiry, true);260 if (ret < 0) {261 _leave(" = %d [dns]", ret);262 return ERR_PTR(ret);263 }264 265 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 else271 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;278}279 280/*281 * Merge an IPv4 entry into a fileserver address list.282 */283int afs_merge_fs_addr4(struct afs_net *net, struct afs_addr_list *alist,284 __be32 xdr, u16 port)285{286 struct sockaddr_rxrpc srx;287 struct rxrpc_peer *peer;288 int i;289 290 if (alist->nr_addrs >= alist->max_addrs)291 return 0;292 293 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;299 300 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)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));317 318 alist->addrs[i].peer = peer;319 alist->nr_ipv4++;320 alist->nr_addrs++;321 return 0;322}323 324/*325 * Merge an IPv6 entry into a fileserver address list.326 */327int afs_merge_fs_addr6(struct afs_net *net, struct afs_addr_list *alist,328 __be32 *xdr, u16 port)329{330 struct sockaddr_rxrpc srx;331 struct rxrpc_peer *peer;332 int i;333 334 if (alist->nr_addrs >= alist->max_addrs)335 return 0;336 337 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);343 344 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)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));361 alist->addrs[i].peer = peer;362 alist->nr_addrs++;363 return 0;364}365