// SPDX-License-Identifier: GPL-2.0+ /* * linux/net/sunrpc/gss_rpc_upcall.c * * Copyright (C) 2012 Simo Sorce <simo@redhat.com> */ #include <linux/types.h> #include <linux/un.h> #include <linux/sunrpc/svcauth.h> #include "gss_rpc_upcall.h" #define GSSPROXY_SOCK_PATHNAME "/var/run/gssproxy.sock" #define GSSPROXY_PROGRAM (400112u) #define GSSPROXY_VERS_1 (1u) /* * Encoding/Decoding functions */ enum { GSSX_NULL = 0, /* Unused */ GSSX_INDICATE_MECHS = 1, GSSX_GET_CALL_CONTEXT = 2, GSSX_IMPORT_AND_CANON_NAME = 3, GSSX_EXPORT_CRED = 4, GSSX_IMPORT_CRED = 5, GSSX_ACQUIRE_CRED = 6, GSSX_STORE_CRED = 7, GSSX_INIT_SEC_CONTEXT = 8, GSSX_ACCEPT_SEC_CONTEXT = 9, GSSX_RELEASE_HANDLE = 10, GSSX_GET_MIC = 11, GSSX_VERIFY = 12, GSSX_WRAP = 13, GSSX_UNWRAP = 14, GSSX_WRAP_SIZE_LIMIT = 15, }; #define PROC(proc, name) \ [GSSX_##proc] = { \ .p_proc = GSSX_##proc, \ .p_encode = gssx_enc_##name, \ .p_decode = gssx_dec_##name, \ .p_arglen = GSSX_ARG_##name##_sz, \ .p_replen = GSSX_RES_##name##_sz, \ .p_statidx = GSSX_##proc, \ .p_name = #proc, \ } static const struct rpc_procinfo gssp_procedures[] = { PROC(INDICATE_MECHS, indicate_mechs), PROC(GET_CALL_CONTEXT, get_call_context), PROC(IMPORT_AND_CANON_NAME, import_and_canon_name), PROC(EXPORT_CRED, export_cred), PROC(IMPORT_CRED, import_cred), PROC(ACQUIRE_CRED, acquire_cred), PROC(STORE_CRED, store_cred), PROC(INIT_SEC_CONTEXT, init_sec_context), PROC(ACCEPT_SEC_CONTEXT, accept_sec_context), PROC(RELEASE_HANDLE, release_handle), PROC(GET_MIC, get_mic), PROC(VERIFY, verify), PROC(WRAP, wrap), PROC(UNWRAP, unwrap), PROC(WRAP_SIZE_LIMIT, wrap_size_limit), }; /* * Common transport functions */ static const struct rpc_program gssp_program; static int gssp_rpc_create(struct net *net, struct rpc_clnt **_clnt) { static const struct sockaddr_un gssp_localaddr = { .sun_family = AF_LOCAL, .sun_path = GSSPROXY_SOCK_PATHNAME, }; struct rpc_create_args args = { .net = net, .protocol = XPRT_TRANSPORT_LOCAL, .address = (struct sockaddr *)&gssp_localaddr, .addrsize = sizeof(gssp_localaddr), .servername = "localhost", .program = &gssp_program, .version = GSSPROXY_VERS_1, .authflavor = RPC_AUTH_NULL, /* * Note we want connection to be done in the caller's * filesystem namespace. We therefore turn off the idle * timeout, which would result in reconnections being * done without the correct namespace: */ .flags = RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_NO_IDLE_TIMEOUT }; struct rpc_clnt *clnt; int result = 0; clnt = rpc_create(&args); if (IS_ERR(clnt)) { dprintk("RPC: failed to create AF_LOCAL gssproxy " "client (errno %ld).\n", PTR_ERR(clnt)); result = PTR_ERR(clnt); *_clnt = NULL; goto out; } dprintk("RPC: created new gssp local client (gssp_local_clnt: " "%p)\n", clnt); *_clnt = clnt; out: return result; } void init_gssp_clnt(struct sunrpc_net *sn) { mutex_init(&sn->gssp_lock); sn->gssp_clnt = NULL; } int set_gssp_clnt(struct net *net) { struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); struct rpc_clnt *clnt; int ret; mutex_lock(&sn->gssp_lock); ret = gssp_rpc_create(net, &clnt); if (!ret) { if (sn->gssp_clnt) rpc_shutdown_client(sn->gssp_clnt); sn->gssp_clnt = clnt; } mutex_unlock(&sn->gssp_lock); return ret; } void clear_gssp_clnt(struct sunrpc_net *sn) { mutex_lock(&sn->gssp_lock); if (sn->gssp_clnt) { rpc_shutdown_client(sn->gssp_clnt); sn->gssp_clnt = NULL; } mutex_unlock(&sn->gssp_lock); } static struct rpc_clnt *get_gssp_clnt(struct sunrpc_net *sn) { struct rpc_clnt *clnt; mutex_lock(&sn->gssp_lock); clnt = sn->gssp_clnt; if (clnt) refcount_inc(&clnt->cl_count); mutex_unlock(&sn->gssp_lock); return clnt; } static int gssp_call(struct net *net, struct rpc_message *msg) { struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); struct rpc_clnt *clnt; int status; clnt = get_gssp_clnt(sn); if (!clnt) return -EIO; status = rpc_call_sync(clnt, msg, 0); if (status < 0) { dprintk("gssp: rpc_call returned error %d\n", -status); switch (status) { case -EPROTONOSUPPORT: status = -EINVAL; break; case -ECONNREFUSED: case -ETIMEDOUT: case -ENOTCONN: status = -EAGAIN; break; case -ERESTARTSYS: if (signalled ()) status = -EINTR; break; default: break; } } rpc_release_client(clnt); return status; } static void gssp_free_receive_pages(struct gssx_arg_accept_sec_context *arg) { unsigned int i; for (i = 0; i < arg->npages && arg->pages[i]; i++) __free_page(arg->pages[i]); kfree(arg->pages); } static int gssp_alloc_receive_pages(struct gssx_arg_accept_sec_context *arg) { unsigned int i; arg->npages = DIV_ROUND_UP(NGROUPS_MAX * 4, PAGE_SIZE); arg->pages = kcalloc(arg->npages, sizeof(struct page *), GFP_KERNEL); if (!arg->pages) return -ENOMEM; for (i = 0; i < arg->npages; i++) { arg->pages[i] = alloc_page(GFP_KERNEL); if (!arg->pages[i]) { gssp_free_receive_pages(arg); return -ENOMEM; } } return 0; } static char *gssp_stringify(struct xdr_netobj *netobj) { return kmemdup_nul(netobj->data, netobj->len, GFP_KERNEL); } static void gssp_hostbased_service(char **principal) { char *c; if (!*principal) return; /* terminate and remove realm part */ c = strchr(*principal, '@'); if (c) { *c = '\0'; /* change service-hostname delimiter */ c = strchr(*principal, '/'); if (c) *c = '@'; } if (!c) { /* not a service principal */ kfree(*principal); *principal = NULL; } } /* * Public functions */ /* numbers somewhat arbitrary but large enough for current needs */ #define GSSX_MAX_OUT_HANDLE 128 #define GSSX_MAX_SRC_PRINC 256 #define GSSX_KMEMBUF (GSSX_max_output_handle_sz + \ GSSX_max_oid_sz + \ GSSX_max_princ_sz + \ sizeof(struct svc_cred)) int gssp_accept_sec_context_upcall(struct net *net, struct gssp_upcall_data *data) { struct gssx_ctx ctxh = { .state = data->in_handle }; struct gssx_arg_accept_sec_context arg = { .input_token = data->in_token, }; struct gssx_ctx rctxh = { /* * pass in the max length we expect for each of these * buffers but let the xdr code kmalloc them: */ .exported_context_token.len = GSSX_max_output_handle_sz, .mech.len = GSS_OID_MAX_LEN, .targ_name.display_name.len = GSSX_max_princ_sz, .src_name.display_name.len = GSSX_max_princ_sz }; struct gssx_res_accept_sec_context res = { .context_handle = &rctxh, .output_token = &data->out_token }; struct rpc_message msg = { .rpc_proc = &gssp_procedures[GSSX_ACCEPT_SEC_CONTEXT], .rpc_argp = &arg, .rpc_resp = &res, .rpc_cred = NULL, /* FIXME ? */ }; struct xdr_netobj client_name = { 0 , NULL }; struct xdr_netobj target_name = { 0, NULL }; int ret; if (data->in_handle.len != 0) arg.context_handle = &ctxh; res.output_token->len = GSSX_max_output_token_sz; ret = gssp_alloc_receive_pages(&arg); if (ret) return ret; ret = gssp_call(net, &msg); gssp_free_receive_pages(&arg); /* we need to fetch all data even in case of error so * that we can free special strctures is they have been allocated */ data->major_status = res.status.major_status; data->minor_status = res.status.minor_status; if (res.context_handle) { data->out_handle = rctxh.exported_context_token; data->mech_oid.len = rctxh.mech.len; if (rctxh.mech.data) { memcpy(data->mech_oid.data, rctxh.mech.data, data->mech_oid.len); kfree(rctxh.mech.data); } client_name = rctxh.src_name.display_name; target_name = rctxh.targ_name.display_name; } if (res.options.count == 1) { gssx_buffer *value = &res.options.data[0].value; /* Currently we only decode CREDS_VALUE, if we add * anything else we'll have to loop and match on the * option name */ if (value->len == 1) { /* steal group info from struct svc_cred */ data->creds = *(struct svc_cred *)value->data; data->found_creds = 1; } /* whether we use it or not, free data */ kfree(value->data); } if (res.options.count != 0) { kfree(res.options.data); } /* convert to GSS_NT_HOSTBASED_SERVICE form and set into creds */ if (data->found_creds) { if (client_name.data) { data->creds.cr_raw_principal = gssp_stringify(&client_name); data->creds.cr_principal = gssp_stringify(&client_name); gssp_hostbased_service(&data->creds.cr_principal); } if (target_name.data) { data->creds.cr_targ_princ = gssp_stringify(&target_name); gssp_hostbased_service(&data->creds.cr_targ_princ); } } kfree(client_name.data); kfree(target_name.data); return ret; } void gssp_free_upcall_data(struct gssp_upcall_data *data) { kfree(data->in_handle.data); kfree(data->out_handle.data); kfree(data->out_token.data); free_svc_cred(&data->creds); } /* * Initialization stuff */ static unsigned int gssp_version1_counts[ARRAY_SIZE(gssp_procedures)]; static const struct rpc_version gssp_version1 = { .number = GSSPROXY_VERS_1, .nrprocs = ARRAY_SIZE(gssp_procedures), .procs = gssp_procedures, .counts = gssp_version1_counts, }; static const struct rpc_version *gssp_version[] = { NULL, &gssp_version1, }; static struct rpc_stat gssp_stats; static const struct rpc_program gssp_program = { .name = "gssproxy", .number = GSSPROXY_PROGRAM, .nrvers = ARRAY_SIZE(gssp_version), .version = gssp_version, .stats = &gssp_stats, };