1ab9953ffSGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0 21ffaa640SHendrik Brueckner /* 31ffaa640SHendrik Brueckner * Deliver z/VM CP special messages (SMSG) as uevents. 41ffaa640SHendrik Brueckner * 51ffaa640SHendrik Brueckner * The driver registers for z/VM CP special messages with the 61ffaa640SHendrik Brueckner * "APP" prefix. Incoming messages are delivered to user space 71ffaa640SHendrik Brueckner * as uevents. 81ffaa640SHendrik Brueckner * 91ffaa640SHendrik Brueckner * Copyright IBM Corp. 2010 101ffaa640SHendrik Brueckner * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com> 111ffaa640SHendrik Brueckner * 121ffaa640SHendrik Brueckner */ 131ffaa640SHendrik Brueckner #define KMSG_COMPONENT "smsgiucv_app" 141ffaa640SHendrik Brueckner #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 151ffaa640SHendrik Brueckner 161ffaa640SHendrik Brueckner #include <linux/ctype.h> 171ffaa640SHendrik Brueckner #include <linux/err.h> 181ffaa640SHendrik Brueckner #include <linux/device.h> 191ffaa640SHendrik Brueckner #include <linux/list.h> 201ffaa640SHendrik Brueckner #include <linux/kobject.h> 211ffaa640SHendrik Brueckner #include <linux/module.h> 225a0e3ad6STejun Heo #include <linux/slab.h> 231ffaa640SHendrik Brueckner #include <linux/spinlock.h> 241ffaa640SHendrik Brueckner #include <linux/workqueue.h> 251ffaa640SHendrik Brueckner #include <net/iucv/iucv.h> 261ffaa640SHendrik Brueckner #include "smsgiucv.h" 271ffaa640SHendrik Brueckner 281ffaa640SHendrik Brueckner /* prefix used for SMSG registration */ 291ffaa640SHendrik Brueckner #define SMSG_PREFIX "APP" 301ffaa640SHendrik Brueckner 311ffaa640SHendrik Brueckner /* SMSG related uevent environment variables */ 321ffaa640SHendrik Brueckner #define ENV_SENDER_STR "SMSG_SENDER=" 331ffaa640SHendrik Brueckner #define ENV_SENDER_LEN (strlen(ENV_SENDER_STR) + 8 + 1) 341ffaa640SHendrik Brueckner #define ENV_PREFIX_STR "SMSG_ID=" 351ffaa640SHendrik Brueckner #define ENV_PREFIX_LEN (strlen(ENV_PREFIX_STR) + \ 361ffaa640SHendrik Brueckner strlen(SMSG_PREFIX) + 1) 371ffaa640SHendrik Brueckner #define ENV_TEXT_STR "SMSG_TEXT=" 381ffaa640SHendrik Brueckner #define ENV_TEXT_LEN(msg) (strlen(ENV_TEXT_STR) + strlen((msg)) + 1) 391ffaa640SHendrik Brueckner 401ffaa640SHendrik Brueckner /* z/VM user ID which is permitted to send SMSGs 411ffaa640SHendrik Brueckner * If the value is undefined or empty (""), special messages are 421ffaa640SHendrik Brueckner * accepted from any z/VM user ID. */ 431ffaa640SHendrik Brueckner static char *sender; 441ffaa640SHendrik Brueckner module_param(sender, charp, 0400); 451ffaa640SHendrik Brueckner MODULE_PARM_DESC(sender, "z/VM user ID from which CP SMSGs are accepted"); 461ffaa640SHendrik Brueckner 471ffaa640SHendrik Brueckner /* SMSG device representation */ 481ffaa640SHendrik Brueckner static struct device *smsg_app_dev; 491ffaa640SHendrik Brueckner 501ffaa640SHendrik Brueckner /* list element for queuing received messages for delivery */ 511ffaa640SHendrik Brueckner struct smsg_app_event { 521ffaa640SHendrik Brueckner struct list_head list; 531ffaa640SHendrik Brueckner char *buf; 541ffaa640SHendrik Brueckner char *envp[4]; 551ffaa640SHendrik Brueckner }; 561ffaa640SHendrik Brueckner 571ffaa640SHendrik Brueckner /* queue for outgoing uevents */ 581ffaa640SHendrik Brueckner static LIST_HEAD(smsg_event_queue); 591ffaa640SHendrik Brueckner static DEFINE_SPINLOCK(smsg_event_queue_lock); 601ffaa640SHendrik Brueckner 611ffaa640SHendrik Brueckner static void smsg_app_event_free(struct smsg_app_event *ev) 621ffaa640SHendrik Brueckner { 631ffaa640SHendrik Brueckner kfree(ev->buf); 641ffaa640SHendrik Brueckner kfree(ev); 651ffaa640SHendrik Brueckner } 661ffaa640SHendrik Brueckner 671ffaa640SHendrik Brueckner static struct smsg_app_event *smsg_app_event_alloc(const char *from, 681ffaa640SHendrik Brueckner const char *msg) 691ffaa640SHendrik Brueckner { 701ffaa640SHendrik Brueckner struct smsg_app_event *ev; 711ffaa640SHendrik Brueckner 721ffaa640SHendrik Brueckner ev = kzalloc(sizeof(*ev), GFP_ATOMIC); 731ffaa640SHendrik Brueckner if (!ev) 741ffaa640SHendrik Brueckner return NULL; 751ffaa640SHendrik Brueckner 761ffaa640SHendrik Brueckner ev->buf = kzalloc(ENV_SENDER_LEN + ENV_PREFIX_LEN + 771ffaa640SHendrik Brueckner ENV_TEXT_LEN(msg), GFP_ATOMIC); 781ffaa640SHendrik Brueckner if (!ev->buf) { 791ffaa640SHendrik Brueckner kfree(ev); 801ffaa640SHendrik Brueckner return NULL; 811ffaa640SHendrik Brueckner } 821ffaa640SHendrik Brueckner 831ffaa640SHendrik Brueckner /* setting up environment pointers into buf */ 841ffaa640SHendrik Brueckner ev->envp[0] = ev->buf; 851ffaa640SHendrik Brueckner ev->envp[1] = ev->envp[0] + ENV_SENDER_LEN; 861ffaa640SHendrik Brueckner ev->envp[2] = ev->envp[1] + ENV_PREFIX_LEN; 871ffaa640SHendrik Brueckner ev->envp[3] = NULL; 881ffaa640SHendrik Brueckner 891ffaa640SHendrik Brueckner /* setting up environment: sender, prefix name, and message text */ 901ffaa640SHendrik Brueckner snprintf(ev->envp[0], ENV_SENDER_LEN, ENV_SENDER_STR "%s", from); 911ffaa640SHendrik Brueckner snprintf(ev->envp[1], ENV_PREFIX_LEN, ENV_PREFIX_STR "%s", SMSG_PREFIX); 921ffaa640SHendrik Brueckner snprintf(ev->envp[2], ENV_TEXT_LEN(msg), ENV_TEXT_STR "%s", msg); 931ffaa640SHendrik Brueckner 941ffaa640SHendrik Brueckner return ev; 951ffaa640SHendrik Brueckner } 961ffaa640SHendrik Brueckner 971ffaa640SHendrik Brueckner static void smsg_event_work_fn(struct work_struct *work) 981ffaa640SHendrik Brueckner { 991ffaa640SHendrik Brueckner LIST_HEAD(event_queue); 1001ffaa640SHendrik Brueckner struct smsg_app_event *p, *n; 1011ffaa640SHendrik Brueckner struct device *dev; 1021ffaa640SHendrik Brueckner 1031ffaa640SHendrik Brueckner dev = get_device(smsg_app_dev); 1041ffaa640SHendrik Brueckner if (!dev) 1051ffaa640SHendrik Brueckner return; 1061ffaa640SHendrik Brueckner 1071ffaa640SHendrik Brueckner spin_lock_bh(&smsg_event_queue_lock); 1081ffaa640SHendrik Brueckner list_splice_init(&smsg_event_queue, &event_queue); 1091ffaa640SHendrik Brueckner spin_unlock_bh(&smsg_event_queue_lock); 1101ffaa640SHendrik Brueckner 1111ffaa640SHendrik Brueckner list_for_each_entry_safe(p, n, &event_queue, list) { 1121ffaa640SHendrik Brueckner list_del(&p->list); 1131ffaa640SHendrik Brueckner kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, p->envp); 1141ffaa640SHendrik Brueckner smsg_app_event_free(p); 1151ffaa640SHendrik Brueckner } 1161ffaa640SHendrik Brueckner 1171ffaa640SHendrik Brueckner put_device(dev); 1181ffaa640SHendrik Brueckner } 1191ffaa640SHendrik Brueckner static DECLARE_WORK(smsg_event_work, smsg_event_work_fn); 1201ffaa640SHendrik Brueckner 1211ffaa640SHendrik Brueckner static void smsg_app_callback(const char *from, char *msg) 1221ffaa640SHendrik Brueckner { 1231ffaa640SHendrik Brueckner struct smsg_app_event *se; 1241ffaa640SHendrik Brueckner 1251ffaa640SHendrik Brueckner /* check if the originating z/VM user ID matches 1261ffaa640SHendrik Brueckner * the configured sender. */ 1271ffaa640SHendrik Brueckner if (sender && strlen(sender) > 0 && strcmp(from, sender) != 0) 1281ffaa640SHendrik Brueckner return; 1291ffaa640SHendrik Brueckner 1301ffaa640SHendrik Brueckner /* get start of message text (skip prefix and leading blanks) */ 1311ffaa640SHendrik Brueckner msg += strlen(SMSG_PREFIX); 1321ffaa640SHendrik Brueckner while (*msg && isspace(*msg)) 1331ffaa640SHendrik Brueckner msg++; 1341ffaa640SHendrik Brueckner if (*msg == '\0') 1351ffaa640SHendrik Brueckner return; 1361ffaa640SHendrik Brueckner 1371ffaa640SHendrik Brueckner /* allocate event list element and its environment */ 1381ffaa640SHendrik Brueckner se = smsg_app_event_alloc(from, msg); 1391ffaa640SHendrik Brueckner if (!se) 1401ffaa640SHendrik Brueckner return; 1411ffaa640SHendrik Brueckner 1421ffaa640SHendrik Brueckner /* queue event and schedule work function */ 1431ffaa640SHendrik Brueckner spin_lock(&smsg_event_queue_lock); 1441ffaa640SHendrik Brueckner list_add_tail(&se->list, &smsg_event_queue); 1451ffaa640SHendrik Brueckner spin_unlock(&smsg_event_queue_lock); 1461ffaa640SHendrik Brueckner 1471ffaa640SHendrik Brueckner schedule_work(&smsg_event_work); 1481ffaa640SHendrik Brueckner return; 1491ffaa640SHendrik Brueckner } 1501ffaa640SHendrik Brueckner 1511ffaa640SHendrik Brueckner static int __init smsgiucv_app_init(void) 1521ffaa640SHendrik Brueckner { 1531ffaa640SHendrik Brueckner struct device_driver *smsgiucv_drv; 1541ffaa640SHendrik Brueckner int rc; 1551ffaa640SHendrik Brueckner 1561ffaa640SHendrik Brueckner if (!MACHINE_IS_VM) 1571ffaa640SHendrik Brueckner return -ENODEV; 1581ffaa640SHendrik Brueckner 159*3bbde49eSHeiko Carstens smsgiucv_drv = driver_find(SMSGIUCV_DRV_NAME, &iucv_bus); 160*3bbde49eSHeiko Carstens if (!smsgiucv_drv) 161*3bbde49eSHeiko Carstens return -ENODEV; 162*3bbde49eSHeiko Carstens 163*3bbde49eSHeiko Carstens smsg_app_dev = iucv_alloc_device(NULL, smsgiucv_drv, NULL, KMSG_COMPONENT); 1641ffaa640SHendrik Brueckner if (!smsg_app_dev) 1651ffaa640SHendrik Brueckner return -ENOMEM; 1661ffaa640SHendrik Brueckner 1671ffaa640SHendrik Brueckner rc = device_register(smsg_app_dev); 1681ffaa640SHendrik Brueckner if (rc) { 1691ffaa640SHendrik Brueckner put_device(smsg_app_dev); 170fde25a9bSAlan Stern goto fail; 1711ffaa640SHendrik Brueckner } 1721ffaa640SHendrik Brueckner 17341b42876SHendrik Brueckner /* convert sender to uppercase characters */ 17441b42876SHendrik Brueckner if (sender) { 17541b42876SHendrik Brueckner int len = strlen(sender); 17641b42876SHendrik Brueckner while (len--) 17741b42876SHendrik Brueckner sender[len] = toupper(sender[len]); 17841b42876SHendrik Brueckner } 17941b42876SHendrik Brueckner 1801ffaa640SHendrik Brueckner /* register with the smsgiucv device driver */ 1811ffaa640SHendrik Brueckner rc = smsg_register_callback(SMSG_PREFIX, smsg_app_callback); 1821ffaa640SHendrik Brueckner if (rc) { 1831ffaa640SHendrik Brueckner device_unregister(smsg_app_dev); 184fde25a9bSAlan Stern goto fail; 1851ffaa640SHendrik Brueckner } 1861ffaa640SHendrik Brueckner 1871ffaa640SHendrik Brueckner rc = 0; 188fde25a9bSAlan Stern fail: 1891ffaa640SHendrik Brueckner return rc; 1901ffaa640SHendrik Brueckner } 1911ffaa640SHendrik Brueckner module_init(smsgiucv_app_init); 1921ffaa640SHendrik Brueckner 1931ffaa640SHendrik Brueckner static void __exit smsgiucv_app_exit(void) 1941ffaa640SHendrik Brueckner { 1951ffaa640SHendrik Brueckner /* unregister callback */ 1961ffaa640SHendrik Brueckner smsg_unregister_callback(SMSG_PREFIX, smsg_app_callback); 1971ffaa640SHendrik Brueckner 1981ffaa640SHendrik Brueckner /* cancel pending work and flush any queued event work */ 1991ffaa640SHendrik Brueckner cancel_work_sync(&smsg_event_work); 2001ffaa640SHendrik Brueckner smsg_event_work_fn(&smsg_event_work); 2011ffaa640SHendrik Brueckner 2021ffaa640SHendrik Brueckner device_unregister(smsg_app_dev); 2031ffaa640SHendrik Brueckner } 2041ffaa640SHendrik Brueckner module_exit(smsgiucv_app_exit); 2051ffaa640SHendrik Brueckner 2061ffaa640SHendrik Brueckner MODULE_LICENSE("GPL v2"); 2071ffaa640SHendrik Brueckner MODULE_DESCRIPTION("Deliver z/VM CP SMSG as uevents"); 2081ffaa640SHendrik Brueckner MODULE_AUTHOR("Hendrik Brueckner <brueckner@linux.vnet.ibm.com>"); 209