1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * linux/net/sunrpc/gss_rpc_upcall.c 4 * 5 * Copyright (C) 2012 Simo Sorce <simo@redhat.com> 6 */ 7 8 #include <linux/types.h> 9 #include <linux/un.h> 10 11 #include <linux/sunrpc/svcauth.h> 12 #include "gss_rpc_upcall.h" 13 14 #define GSSPROXY_SOCK_PATHNAME "/var/run/gssproxy.sock" 15 16 #define GSSPROXY_PROGRAM (400112u) 17 #define GSSPROXY_VERS_1 (1u) 18 19 /* 20 * Encoding/Decoding functions 21 */ 22 23 enum { 24 GSSX_NULL = 0, /* Unused */ 25 GSSX_INDICATE_MECHS = 1, 26 GSSX_GET_CALL_CONTEXT = 2, 27 GSSX_IMPORT_AND_CANON_NAME = 3, 28 GSSX_EXPORT_CRED = 4, 29 GSSX_IMPORT_CRED = 5, 30 GSSX_ACQUIRE_CRED = 6, 31 GSSX_STORE_CRED = 7, 32 GSSX_INIT_SEC_CONTEXT = 8, 33 GSSX_ACCEPT_SEC_CONTEXT = 9, 34 GSSX_RELEASE_HANDLE = 10, 35 GSSX_GET_MIC = 11, 36 GSSX_VERIFY = 12, 37 GSSX_WRAP = 13, 38 GSSX_UNWRAP = 14, 39 GSSX_WRAP_SIZE_LIMIT = 15, 40 }; 41 42 #define PROC(proc, name) \ 43 [GSSX_##proc] = { \ 44 .p_proc = GSSX_##proc, \ 45 .p_encode = gssx_enc_##name, \ 46 .p_decode = gssx_dec_##name, \ 47 .p_arglen = GSSX_ARG_##name##_sz, \ 48 .p_replen = GSSX_RES_##name##_sz, \ 49 .p_statidx = GSSX_##proc, \ 50 .p_name = #proc, \ 51 } 52 53 static const struct rpc_procinfo gssp_procedures[] = { 54 PROC(INDICATE_MECHS, indicate_mechs), 55 PROC(GET_CALL_CONTEXT, get_call_context), 56 PROC(IMPORT_AND_CANON_NAME, import_and_canon_name), 57 PROC(EXPORT_CRED, export_cred), 58 PROC(IMPORT_CRED, import_cred), 59 PROC(ACQUIRE_CRED, acquire_cred), 60 PROC(STORE_CRED, store_cred), 61 PROC(INIT_SEC_CONTEXT, init_sec_context), 62 PROC(ACCEPT_SEC_CONTEXT, accept_sec_context), 63 PROC(RELEASE_HANDLE, release_handle), 64 PROC(GET_MIC, get_mic), 65 PROC(VERIFY, verify), 66 PROC(WRAP, wrap), 67 PROC(UNWRAP, unwrap), 68 PROC(WRAP_SIZE_LIMIT, wrap_size_limit), 69 }; 70 71 72 73 /* 74 * Common transport functions 75 */ 76 77 static const struct rpc_program gssp_program; 78 79 static int gssp_rpc_create(struct net *net, struct rpc_clnt **_clnt) 80 { 81 static const struct sockaddr_un gssp_localaddr = { 82 .sun_family = AF_LOCAL, 83 .sun_path = GSSPROXY_SOCK_PATHNAME, 84 }; 85 struct rpc_create_args args = { 86 .net = net, 87 .protocol = XPRT_TRANSPORT_LOCAL, 88 .address = (struct sockaddr *)&gssp_localaddr, 89 .addrsize = sizeof(gssp_localaddr), 90 .servername = "localhost", 91 .program = &gssp_program, 92 .version = GSSPROXY_VERS_1, 93 .authflavor = RPC_AUTH_NULL, 94 /* 95 * Note we want connection to be done in the caller's 96 * filesystem namespace. We therefore turn off the idle 97 * timeout, which would result in reconnections being 98 * done without the correct namespace: 99 */ 100 .flags = RPC_CLNT_CREATE_NOPING | 101 RPC_CLNT_CREATE_CONNECTED | 102 RPC_CLNT_CREATE_NO_IDLE_TIMEOUT 103 }; 104 struct rpc_clnt *clnt; 105 int result = 0; 106 107 clnt = rpc_create(&args); 108 if (IS_ERR(clnt)) { 109 dprintk("RPC: failed to create AF_LOCAL gssproxy " 110 "client (errno %ld).\n", PTR_ERR(clnt)); 111 result = PTR_ERR(clnt); 112 *_clnt = NULL; 113 goto out; 114 } 115 116 dprintk("RPC: created new gssp local client (gssp_local_clnt: " 117 "%p)\n", clnt); 118 *_clnt = clnt; 119 120 out: 121 return result; 122 } 123 124 void init_gssp_clnt(struct sunrpc_net *sn) 125 { 126 mutex_init(&sn->gssp_lock); 127 sn->gssp_clnt = NULL; 128 } 129 130 int set_gssp_clnt(struct net *net) 131 { 132 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 133 struct rpc_clnt *clnt; 134 int ret; 135 136 mutex_lock(&sn->gssp_lock); 137 ret = gssp_rpc_create(net, &clnt); 138 if (!ret) { 139 if (sn->gssp_clnt) 140 rpc_shutdown_client(sn->gssp_clnt); 141 sn->gssp_clnt = clnt; 142 } 143 mutex_unlock(&sn->gssp_lock); 144 return ret; 145 } 146 147 void clear_gssp_clnt(struct sunrpc_net *sn) 148 { 149 mutex_lock(&sn->gssp_lock); 150 if (sn->gssp_clnt) { 151 rpc_shutdown_client(sn->gssp_clnt); 152 sn->gssp_clnt = NULL; 153 } 154 mutex_unlock(&sn->gssp_lock); 155 } 156 157 static struct rpc_clnt *get_gssp_clnt(struct sunrpc_net *sn) 158 { 159 struct rpc_clnt *clnt; 160 161 mutex_lock(&sn->gssp_lock); 162 clnt = sn->gssp_clnt; 163 if (clnt) 164 refcount_inc(&clnt->cl_count); 165 mutex_unlock(&sn->gssp_lock); 166 return clnt; 167 } 168 169 static int gssp_call(struct net *net, struct rpc_message *msg) 170 { 171 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 172 struct rpc_clnt *clnt; 173 int status; 174 175 clnt = get_gssp_clnt(sn); 176 if (!clnt) 177 return -EIO; 178 status = rpc_call_sync(clnt, msg, 0); 179 if (status < 0) { 180 dprintk("gssp: rpc_call returned error %d\n", -status); 181 switch (status) { 182 case -EPROTONOSUPPORT: 183 status = -EINVAL; 184 break; 185 case -ECONNREFUSED: 186 case -ETIMEDOUT: 187 case -ENOTCONN: 188 status = -EAGAIN; 189 break; 190 case -ERESTARTSYS: 191 if (signalled ()) 192 status = -EINTR; 193 break; 194 default: 195 break; 196 } 197 } 198 rpc_release_client(clnt); 199 return status; 200 } 201 202 static void gssp_free_receive_pages(struct gssx_arg_accept_sec_context *arg) 203 { 204 unsigned int i; 205 206 for (i = 0; i < arg->npages && arg->pages[i]; i++) 207 __free_page(arg->pages[i]); 208 209 kfree(arg->pages); 210 } 211 212 static int gssp_alloc_receive_pages(struct gssx_arg_accept_sec_context *arg) 213 { 214 unsigned int i; 215 216 arg->npages = DIV_ROUND_UP(NGROUPS_MAX * 4, PAGE_SIZE); 217 arg->pages = kcalloc(arg->npages, sizeof(struct page *), GFP_KERNEL); 218 if (!arg->pages) 219 return -ENOMEM; 220 for (i = 0; i < arg->npages; i++) { 221 arg->pages[i] = alloc_page(GFP_KERNEL); 222 if (!arg->pages[i]) { 223 gssp_free_receive_pages(arg); 224 return -ENOMEM; 225 } 226 } 227 return 0; 228 } 229 230 static char *gssp_stringify(struct xdr_netobj *netobj) 231 { 232 return kmemdup_nul(netobj->data, netobj->len, GFP_KERNEL); 233 } 234 235 static void gssp_hostbased_service(char **principal) 236 { 237 char *c; 238 239 if (!*principal) 240 return; 241 242 /* terminate and remove realm part */ 243 c = strchr(*principal, '@'); 244 if (c) { 245 *c = '\0'; 246 247 /* change service-hostname delimiter */ 248 c = strchr(*principal, '/'); 249 if (c) 250 *c = '@'; 251 } 252 if (!c) { 253 /* not a service principal */ 254 kfree(*principal); 255 *principal = NULL; 256 } 257 } 258 259 /* 260 * Public functions 261 */ 262 263 /* numbers somewhat arbitrary but large enough for current needs */ 264 #define GSSX_MAX_OUT_HANDLE 128 265 #define GSSX_MAX_SRC_PRINC 256 266 #define GSSX_KMEMBUF (GSSX_max_output_handle_sz + \ 267 GSSX_max_oid_sz + \ 268 GSSX_max_princ_sz + \ 269 sizeof(struct svc_cred)) 270 271 int gssp_accept_sec_context_upcall(struct net *net, 272 struct gssp_upcall_data *data) 273 { 274 struct gssx_ctx ctxh = { 275 .state = data->in_handle 276 }; 277 struct gssx_arg_accept_sec_context arg = { 278 .input_token = data->in_token, 279 }; 280 struct gssx_ctx rctxh = { 281 /* 282 * pass in the max length we expect for each of these 283 * buffers but let the xdr code kmalloc them: 284 */ 285 .exported_context_token.len = GSSX_max_output_handle_sz, 286 .mech.len = GSS_OID_MAX_LEN, 287 .targ_name.display_name.len = GSSX_max_princ_sz, 288 .src_name.display_name.len = GSSX_max_princ_sz 289 }; 290 struct gssx_res_accept_sec_context res = { 291 .context_handle = &rctxh, 292 .output_token = &data->out_token 293 }; 294 struct rpc_message msg = { 295 .rpc_proc = &gssp_procedures[GSSX_ACCEPT_SEC_CONTEXT], 296 .rpc_argp = &arg, 297 .rpc_resp = &res, 298 .rpc_cred = NULL, /* FIXME ? */ 299 }; 300 struct xdr_netobj client_name = { 0 , NULL }; 301 struct xdr_netobj target_name = { 0, NULL }; 302 int ret; 303 304 if (data->in_handle.len != 0) 305 arg.context_handle = &ctxh; 306 res.output_token->len = GSSX_max_output_token_sz; 307 308 ret = gssp_alloc_receive_pages(&arg); 309 if (ret) 310 return ret; 311 312 ret = gssp_call(net, &msg); 313 314 gssp_free_receive_pages(&arg); 315 316 /* we need to fetch all data even in case of error so 317 * that we can free special strctures is they have been allocated */ 318 data->major_status = res.status.major_status; 319 data->minor_status = res.status.minor_status; 320 if (res.context_handle) { 321 data->out_handle = rctxh.exported_context_token; 322 data->mech_oid.len = rctxh.mech.len; 323 if (rctxh.mech.data) { 324 memcpy(data->mech_oid.data, rctxh.mech.data, 325 data->mech_oid.len); 326 kfree(rctxh.mech.data); 327 } 328 client_name = rctxh.src_name.display_name; 329 target_name = rctxh.targ_name.display_name; 330 } 331 332 if (res.options.count == 1) { 333 gssx_buffer *value = &res.options.data[0].value; 334 /* Currently we only decode CREDS_VALUE, if we add 335 * anything else we'll have to loop and match on the 336 * option name */ 337 if (value->len == 1) { 338 /* steal group info from struct svc_cred */ 339 data->creds = *(struct svc_cred *)value->data; 340 data->found_creds = 1; 341 } 342 /* whether we use it or not, free data */ 343 kfree(value->data); 344 } 345 346 if (res.options.count != 0) { 347 kfree(res.options.data); 348 } 349 350 /* convert to GSS_NT_HOSTBASED_SERVICE form and set into creds */ 351 if (data->found_creds) { 352 if (client_name.data) { 353 data->creds.cr_raw_principal = 354 gssp_stringify(&client_name); 355 data->creds.cr_principal = 356 gssp_stringify(&client_name); 357 gssp_hostbased_service(&data->creds.cr_principal); 358 } 359 if (target_name.data) { 360 data->creds.cr_targ_princ = 361 gssp_stringify(&target_name); 362 gssp_hostbased_service(&data->creds.cr_targ_princ); 363 } 364 } 365 kfree(client_name.data); 366 kfree(target_name.data); 367 368 return ret; 369 } 370 371 void gssp_free_upcall_data(struct gssp_upcall_data *data) 372 { 373 kfree(data->in_handle.data); 374 kfree(data->out_handle.data); 375 kfree(data->out_token.data); 376 free_svc_cred(&data->creds); 377 } 378 379 /* 380 * Initialization stuff 381 */ 382 static unsigned int gssp_version1_counts[ARRAY_SIZE(gssp_procedures)]; 383 static const struct rpc_version gssp_version1 = { 384 .number = GSSPROXY_VERS_1, 385 .nrprocs = ARRAY_SIZE(gssp_procedures), 386 .procs = gssp_procedures, 387 .counts = gssp_version1_counts, 388 }; 389 390 static const struct rpc_version *gssp_version[] = { 391 NULL, 392 &gssp_version1, 393 }; 394 395 static struct rpc_stat gssp_stats; 396 397 static const struct rpc_program gssp_program = { 398 .name = "gssproxy", 399 .number = GSSPROXY_PROGRAM, 400 .nrvers = ARRAY_SIZE(gssp_version), 401 .version = gssp_version, 402 .stats = &gssp_stats, 403 }; 404