/*
- * udevd.c
+ * udevd.c - event listener and serializer
*
- * Userspace devfs
- *
- * Copyright (C) 2004 Ling, Xiaofeng <xiaofeng.ling@intel.com>
- * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
*
*
* This program is free software; you can redistribute it and/or modify it
*/
#include <stddef.h>
-#include <sys/types.h>
-#include <sys/ipc.h>
-#include <sys/wait.h>
-#include <sys/msg.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
-#include <time.h>
+#include <ctype.h>
+#include <dirent.h>
#include <fcntl.h>
+#include <syslog.h>
+#include <sys/select.h>
+#include <sys/wait.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/sysinfo.h>
+#include <sys/stat.h>
+#include <linux/types.h>
+#include <linux/netlink.h>
#include "list.h"
+#include "udev_libc_wrapper.h"
#include "udev.h"
#include "udev_version.h"
+#include "udev_utils.h"
#include "udevd.h"
#include "logging.h"
+/* global variables*/
+static int udevd_sock;
+static int uevent_netlink_sock;
+static pid_t sid;
+
+static int signal_pipe[2] = {-1, -1};
+static volatile int sigchilds_waiting;
+static volatile int run_msg_q;
+static volatile int udev_exit;
+static int init_phase = 1;
+static int run_exec_q;
+static int stop_exec_q;
+static char *udev_bin;
+static int event_timeout;
+static int max_childs;
+static int max_childs_running;
+static unsigned long long expected_seqnum;
+static char log[32];
+
+static LIST_HEAD(msg_list);
+static LIST_HEAD(exec_list);
+static LIST_HEAD(running_list);
+
+
+#ifdef USE_LOG
+void log_message (int priority, const char *format, ...)
+{
+ va_list args;
-#define BUFFER_SIZE 1024
+ if (priority > udev_log_priority)
+ return;
-static int running_remove_queue(pid_t pid);
-static int msg_exec(struct hotplug_msg *msg);
+ va_start(args, format);
+ vsyslog(priority, format, args);
+ va_end(args);
+}
+#endif
-static int expect_seqnum = 0;
-static int lock_file = -1;
-static char *lock_filename = ".udevd_lock";
+static void msg_dump_queue(void)
+{
+#ifdef DEBUG
+ struct uevent_msg *msg;
-LIST_HEAD(msg_list);
-LIST_HEAD(running_list);
-LIST_HEAD(delayed_list);
+ list_for_each_entry(msg, &msg_list, node)
+ dbg("sequence %llu in queue", msg->seqnum);
+#endif
+}
-static void sig_handler(int signum)
+static void msg_queue_delete(struct uevent_msg *msg)
{
- pid_t pid;
+ list_del(&msg->node);
+ free(msg);
+}
- dbg("caught signal %d", signum);
- switch (signum) {
- case SIGALRM:
- dbg("event timeout reached");
- break;
- case SIGCHLD:
- /* catch signals from exiting childs */
- while ( (pid = waitpid(-1, NULL, WNOHANG)) > 0) {
- dbg("exec finished, pid %d", pid);
- running_remove_queue(pid);
- }
- break;
- case SIGINT:
- case SIGTERM:
- if (lock_file >= 0) {
- close(lock_file);
- unlink(lock_filename);
+/* orders the message in the queue by sequence number */
+static void msg_queue_insert(struct uevent_msg *msg)
+{
+ struct uevent_msg *loop_msg;
+ struct sysinfo info;
+
+ if (msg->seqnum == 0) {
+ dbg("no SEQNUM, move straight to the exec queue");
+ list_add_tail(&msg->node, &exec_list);
+ run_exec_q = 1;
+ return;
+ }
+
+ /* store timestamp of queuing */
+ sysinfo(&info);
+ msg->queue_time = info.uptime;
+
+ /* with the first event we provide a phase of shorter timeout */
+ if (init_phase) {
+ static long init_time;
+
+ if (init_time == 0)
+ init_time = info.uptime;
+ if (info.uptime - init_time >= UDEVD_INIT_TIME)
+ init_phase = 0;
+ }
+
+ /* sort message by sequence number into list */
+ list_for_each_entry_reverse(loop_msg, &msg_list, node) {
+ if (loop_msg->seqnum < msg->seqnum)
+ break;
+
+ if (loop_msg->seqnum == msg->seqnum) {
+ dbg("ignoring duplicate message seq %llu", msg->seqnum);
+ free(msg);
+ return;
}
- exit(20 + signum);
- break;
- default:
- dbg("unhandled signal");
}
+ list_add(&msg->node, &loop_msg->node);
+ info("seq %llu queued, '%s' '%s'", msg->seqnum, msg->action, msg->devpath);
+
+ /* run msg queue manager */
+ run_msg_q = 1;
+
+ return;
}
-static void set_timeout(int seconds)
+/* forks event and removes event from run queue when finished */
+static void udev_event_run(struct uevent_msg *msg)
{
- alarm(seconds);
- dbg("set timeout in %d seconds", seconds);
+ char *const argv[] = { "udev", msg->subsystem, NULL };
+ pid_t pid;
+ struct sysinfo info;
+
+ pid = fork();
+ switch (pid) {
+ case 0:
+ /* child */
+ if (uevent_netlink_sock != -1)
+ close(uevent_netlink_sock);
+ close(udevd_sock);
+ logging_close();
+ setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
+ execve(udev_bin, argv, msg->envp);
+ err("exec of child failed");
+ _exit(1);
+ case -1:
+ err("fork of child failed");
+ msg_queue_delete(msg);
+ break;
+ default:
+ /* get SIGCHLD in main loop */
+ sysinfo(&info);
+ info("seq %llu forked, pid [%d], '%s' '%s', %ld seconds old",
+ msg->seqnum, pid, msg->action, msg->subsystem, info.uptime - msg->queue_time);
+ msg->pid = pid;
+ }
}
-static int running_moveto_queue(struct hotplug_msg *msg)
+static int running_processes(void)
{
- dbg("move sequence %d [%d] to running queue '%s'",
- msg->seqnum, msg->pid, msg->devpath);
- list_move_tail(&msg->list, &running_list);
- return 0;
+ int f;
+ static char buf[4096];
+ int len;
+ int running;
+ const char *pos;
+
+ f = open("/proc/stat", O_RDONLY);
+ if (f == -1)
+ return -1;
+
+ len = read(f, buf, sizeof(buf)-1);
+ close(f);
+
+ if (len <= 0)
+ return -1;
+ else
+ buf[len] = '\0';
+
+ pos = strstr(buf, "procs_running ");
+ if (pos == NULL)
+ return -1;
+
+ if (sscanf(pos, "procs_running %u", &running) != 1)
+ return -1;
+
+ return running;
}
-static int running_remove_queue(pid_t pid)
+/* return the number of process es in our session, count only until limit */
+static int running_processes_in_session(pid_t session, int limit)
{
- struct hotplug_msg *child;
- struct hotplug_msg *tmp_child;
-
- list_for_each_entry_safe(child, tmp_child, &running_list, list)
- if (child->pid == pid) {
- list_del_init(&child->list);
- free(child);
- return 0;
- }
- return -EINVAL;
+ DIR *dir;
+ struct dirent *dent;
+ int running = 0;
+
+ dir = opendir("/proc");
+ if (!dir)
+ return -1;
+
+ /* read process info from /proc */
+ for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
+ int f;
+ char procdir[64];
+ char line[256];
+ const char *pos;
+ char state;
+ pid_t ppid, pgrp, sess;
+ int len;
+
+ if (!isdigit(dent->d_name[0]))
+ continue;
+
+ snprintf(procdir, sizeof(procdir), "/proc/%s/stat", dent->d_name);
+ procdir[sizeof(procdir)-1] = '\0';
+
+ f = open(procdir, O_RDONLY);
+ if (f == -1)
+ continue;
+
+ len = read(f, line, sizeof(line)-1);
+ close(f);
+
+ if (len <= 0)
+ continue;
+ else
+ line[len] = '\0';
+
+ /* skip ugly program name */
+ pos = strrchr(line, ')') + 2;
+ if (pos == NULL)
+ continue;
+
+ if (sscanf(pos, "%c %d %d %d ", &state, &ppid, &pgrp, &sess) != 4)
+ continue;
+
+ /* count only processes in our session */
+ if (sess != session)
+ continue;
+
+ /* count only running, no sleeping processes */
+ if (state != 'R')
+ continue;
+
+ running++;
+ if (limit > 0 && running >= limit)
+ break;
+ }
+ closedir(dir);
+
+ return running;
}
-static pid_t running_getpid_by_devpath(struct hotplug_msg *msg)
+static int compare_devpath(const char *running, const char *waiting)
{
- struct hotplug_msg *child;
- struct hotplug_msg *tmp_child;
+ int i;
+
+ for (i = 0; i < PATH_SIZE; i++) {
+ /* identical device event found */
+ if (running[i] == '\0' && waiting[i] == '\0')
+ return 1;
+
+ /* parent device event found */
+ if (running[i] == '\0' && waiting[i] == '/')
+ return 2;
+
+ /* child device event found */
+ if (running[i] == '/' && waiting[i] == '\0')
+ return 3;
+
+ /* no matching event */
+ if (running[i] != waiting[i])
+ break;
+ }
- list_for_each_entry_safe(child, tmp_child, &running_list, list)
- if (strncmp(child->devpath, msg->devpath, sizeof(child->devpath)) == 0)
- return child->pid;
return 0;
}
-static void delayed_dump_queue(void)
+/* returns still running task for the same device, its parent or its physical device */
+static int running_with_devpath(struct uevent_msg *msg, int limit)
{
- struct hotplug_msg *child;
+ struct uevent_msg *loop_msg;
+ int childs_count = 0;
- list_for_each_entry(child, &delayed_list, list)
- dbg("event for '%s' in queue", child->devpath);
-}
+ if (msg->devpath == NULL)
+ return 0;
+
+ /* skip any events with a timeout set */
+ if (msg->timeout != 0)
+ return 0;
+
+ list_for_each_entry(loop_msg, &running_list, node) {
+ if (limit && childs_count++ > limit) {
+ dbg("%llu, maximum number (%i) of child reached", msg->seqnum, childs_count);
+ return 1;
+ }
+ if (loop_msg->devpath == NULL)
+ continue;
+
+ /* return running parent/child device event */
+ if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) {
+ dbg("%llu, child device event still running %llu (%s)",
+ msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
+ return 2;
+ }
+
+ /* return running physical device event */
+ if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0)
+ if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) {
+ dbg("%llu, physical device event still running %llu (%s)",
+ msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
+ return 3;
+ }
+ }
-static int delayed_moveto_queue(struct hotplug_msg *msg)
-{
- dbg("move event to delayed queue '%s'", msg->devpath);
- list_move_tail(&msg->list, &delayed_list);
return 0;
}
-static void delayed_check_queue(void)
+/* exec queue management routine executes the events and serializes events in the same sequence */
+static void exec_queue_manager(void)
{
- struct hotplug_msg *delayed_child;
- struct hotplug_msg *running_child;
- struct hotplug_msg *tmp_child;
-
- /* see if we have delayed exec's that can run now */
- list_for_each_entry_safe(delayed_child, tmp_child, &delayed_list, list)
- list_for_each_entry_safe(running_child, tmp_child, &running_list, list)
- if (strncmp(delayed_child->devpath, running_child->devpath,
- sizeof(running_child->devpath)) == 0) {
- dbg("delayed exec for '%s' can run now", delayed_child->devpath);
- msg_exec(delayed_child);
+ struct uevent_msg *loop_msg;
+ struct uevent_msg *tmp_msg;
+ int running;
+
+ if (list_empty(&exec_list))
+ return;
+
+ running = running_processes();
+ dbg("%d processes runnning on system", running);
+ if (running < 0)
+ running = max_childs_running;
+
+ list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, node) {
+ /* check running processes in our session and possibly throttle */
+ if (running >= max_childs_running) {
+ running = running_processes_in_session(sid, max_childs_running+10);
+ dbg("at least %d processes running in session", running);
+ if (running >= max_childs_running) {
+ dbg("delay seq %llu, cause too many processes already running",
+ loop_msg->seqnum);
+ return;
}
+ }
+
+ if (running_with_devpath(loop_msg, max_childs) == 0) {
+ /* move event to run list */
+ list_move_tail(&loop_msg->node, &running_list);
+ udev_event_run(loop_msg);
+ running++;
+ dbg("moved seq %llu to running list", loop_msg->seqnum);
+ } else
+ dbg("delay seq %llu (%s)", loop_msg->seqnum, loop_msg->devpath);
+ }
}
-static void msg_dump(struct hotplug_msg *msg)
+static void msg_move_exec(struct uevent_msg *msg)
{
- dbg("sequence %d, '%s', '%s', '%s'",
- msg->seqnum, msg->action, msg->devpath, msg->subsystem);
+ list_move_tail(&msg->node, &exec_list);
+ run_exec_q = 1;
+ expected_seqnum = msg->seqnum+1;
+ dbg("moved seq %llu to exec, next expected is %llu",
+ msg->seqnum, expected_seqnum);
}
-static int msg_exec(struct hotplug_msg *msg)
+/* msg queue management routine handles the timeouts and dispatches the events */
+static void msg_queue_manager(void)
{
- pid_t pid;
+ struct uevent_msg *loop_msg;
+ struct uevent_msg *tmp_msg;
+ struct sysinfo info;
+ long msg_age = 0;
+ int timeout = event_timeout;
- msg_dump(msg);
+ dbg("msg queue manager, next expected is %llu", expected_seqnum);
+recheck:
+ sysinfo(&info);
+ list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, node) {
+ /* move event with expected sequence to the exec list */
+ if (loop_msg->seqnum == expected_seqnum) {
+ msg_move_exec(loop_msg);
+ continue;
+ }
- setenv("ACTION", msg->action, 1);
- setenv("DEVPATH", msg->devpath, 1);
+ /* limit timeout during initialization phase */
+ if (init_phase) {
+ timeout = UDEVD_INIT_EVENT_TIMEOUT;
+ dbg("initialization phase, limit timeout to %i seconds", UDEVD_INIT_EVENT_TIMEOUT);
+ }
- /* delay exec, if we already have a udev working on the same devpath */
- pid = running_getpid_by_devpath(msg);
- if (pid != 0) {
- dbg("delay exec of sequence %d, [%d] already working on '%s'",
- msg->seqnum, pid, msg->devpath);
- delayed_moveto_queue(msg);
+ /* move event with expired timeout to the exec list */
+ msg_age = info.uptime - loop_msg->queue_time;
+ dbg("seq %llu is %li seconds old", loop_msg->seqnum, msg_age);
+ if (msg_age >= timeout) {
+ msg_move_exec(loop_msg);
+ goto recheck;
+ } else {
+ break;
+ }
}
- pid = fork();
- switch (pid) {
- case 0:
- /* child */
- execl(UDEV_BIN, "udev", msg->subsystem, NULL);
- dbg("exec of child failed");
- exit(1);
- break;
- case -1:
- dbg("fork of child failed");
- return -1;
- default:
- /* exec in background, get the SIGCHLD with the sig handler */
- msg->pid = pid;
- running_moveto_queue(msg);
- break;
+ msg_dump_queue();
+
+ /* set timeout for remaining queued events */
+ if (!list_empty(&msg_list)) {
+ struct itimerval itv = {{0, 0}, {timeout - msg_age, 0}};
+ info("next event expires in %li seconds", timeout - msg_age);
+ setitimer(ITIMER_REAL, &itv, NULL);
}
- return 0;
}
-static void msg_dump_queue(void)
+static struct uevent_msg *get_msg_from_envbuf(const char *buf, int buf_size)
{
- struct hotplug_msg *msg;
+ int bufpos;
+ int i;
+ struct uevent_msg *msg;
+ int major = 0;
+ int minor = 0;
+
+ msg = malloc(sizeof(struct uevent_msg) + buf_size);
+ if (msg == NULL)
+ return NULL;
+ memset(msg, 0x00, sizeof(struct uevent_msg) + buf_size);
+
+ /* copy environment buffer and reconstruct envp */
+ memcpy(msg->envbuf, buf, buf_size);
+ bufpos = 0;
+ for (i = 0; (bufpos < buf_size) && (i < UEVENT_NUM_ENVP-2); i++) {
+ int keylen;
+ char *key;
+
+ key = &msg->envbuf[bufpos];
+ keylen = strlen(key);
+ msg->envp[i] = key;
+ bufpos += keylen + 1;
+ dbg("add '%s' to msg.envp[%i]", msg->envp[i], i);
+
+ /* remember some keys for further processing */
+ if (strncmp(key, "ACTION=", 7) == 0)
+ msg->action = &key[7];
+ else if (strncmp(key, "DEVPATH=", 8) == 0)
+ msg->devpath = &key[8];
+ else if (strncmp(key, "SUBSYSTEM=", 10) == 0)
+ msg->subsystem = &key[10];
+ else if (strncmp(key, "SEQNUM=", 7) == 0)
+ msg->seqnum = strtoull(&key[7], NULL, 10);
+ else if (strncmp(key, "PHYSDEVPATH=", 12) == 0)
+ msg->physdevpath = &key[12];
+ else if (strncmp(key, "MAJOR=", 6) == 0)
+ major = strtoull(&key[6], NULL, 10);
+ else if (strncmp(key, "MINOR=", 6) == 0)
+ minor = strtoull(&key[6], NULL, 10);
+ else if (strncmp(key, "TIMEOUT=", 8) == 0)
+ msg->timeout = strtoull(&key[8], NULL, 10);
+ }
+ msg->devt = makedev(major, minor);
+ msg->envp[i++] = "UDEVD_EVENT=1";
+ msg->envp[i] = NULL;
- list_for_each_entry(msg, &msg_list, list)
- dbg("sequence %d in queue", msg->seqnum);
+ return msg;
}
-static void msg_check_queue(void)
+/* receive the udevd message from userspace */
+static struct uevent_msg *get_udevd_msg(void)
{
- struct hotplug_msg *msg;
- struct hotplug_msg *tmp_msg;
- time_t msg_age;
+ static struct udevd_msg usend_msg;
+ struct uevent_msg *msg;
+ ssize_t size;
+ struct msghdr smsg;
+ struct cmsghdr *cmsg;
+ struct iovec iov;
+ struct ucred *cred;
+ char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
+ int envbuf_size;
+ int *intval;
+
+ memset(&usend_msg, 0x00, sizeof(struct udevd_msg));
+ iov.iov_base = &usend_msg;
+ iov.iov_len = sizeof(struct udevd_msg);
+
+ memset(&smsg, 0x00, sizeof(struct msghdr));
+ smsg.msg_iov = &iov;
+ smsg.msg_iovlen = 1;
+ smsg.msg_control = cred_msg;
+ smsg.msg_controllen = sizeof(cred_msg);
+
+ size = recvmsg(udevd_sock, &smsg, 0);
+ if (size < 0) {
+ if (errno != EINTR)
+ err("unable to receive udevd message");
+ return NULL;
+ }
+ cmsg = CMSG_FIRSTHDR(&smsg);
+ cred = (struct ucred *) CMSG_DATA(cmsg);
-recheck:
- /* dispatch events until one is missing */
- list_for_each_entry_safe(msg, tmp_msg, &msg_list, list) {
- if (msg->seqnum != expect_seqnum)
- break;
- msg_exec(msg);
- expect_seqnum++;
+ if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
+ err("no sender credentials received, message ignored");
+ return NULL;
}
- /* recalculate next timeout */
- if (list_empty(&msg_list) == 0) {
- msg_age = time(NULL) - msg->queue_time;
- if (msg_age > EVENT_TIMEOUT_SEC-1) {
- info("event %d, age %li seconds, skip event %d-%d",
- msg->seqnum, msg_age, expect_seqnum, msg->seqnum-1);
- expect_seqnum = msg->seqnum;
- goto recheck;
- }
+ if (cred->uid != 0) {
+ err("sender uid=%i, message ignored", cred->uid);
+ return NULL;
+ }
- /* the first sequence gets its own timeout */
- if (expect_seqnum == 0) {
- msg_age = EVENT_TIMEOUT_SEC - FIRST_EVENT_TIMEOUT_SEC;
- expect_seqnum = 1;
- }
+ if (strncmp(usend_msg.magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
+ err("message magic '%s' doesn't match, ignore it", usend_msg.magic);
+ return NULL;
+ }
- set_timeout(EVENT_TIMEOUT_SEC - msg_age);
- return;
+ switch (usend_msg.type) {
+ case UDEVD_UEVENT_UDEVSEND:
+ case UDEVD_UEVENT_INITSEND:
+ info("udevd event message received");
+ envbuf_size = size - offsetof(struct udevd_msg, envbuf);
+ dbg("envbuf_size=%i", envbuf_size);
+ msg = get_msg_from_envbuf(usend_msg.envbuf, envbuf_size);
+ if (msg == NULL)
+ return NULL;
+ msg->type = usend_msg.type;
+ return msg;
+ case UDEVD_STOP_EXEC_QUEUE:
+ info("udevd message (STOP_EXEC_QUEUE) received");
+ stop_exec_q = 1;
+ break;
+ case UDEVD_START_EXEC_QUEUE:
+ info("udevd message (START_EXEC_QUEUE) received");
+ stop_exec_q = 0;
+ exec_queue_manager();
+ break;
+ case UDEVD_SET_LOG_LEVEL:
+ intval = (int *) usend_msg.envbuf;
+ info("udevd message (SET_LOG_PRIORITY) received, udev_log_priority=%i", *intval);
+ udev_log_priority = *intval;
+ sprintf(log, "UDEV_LOG=%i", udev_log_priority);
+ putenv(log);
+ break;
+ case UDEVD_SET_MAX_CHILDS:
+ intval = (int *) usend_msg.envbuf;
+ info("udevd message (UDEVD_SET_MAX_CHILDS) received, max_childs=%i", *intval);
+ max_childs = *intval;
+ break;
+ default:
+ dbg("unknown message type");
}
+ return NULL;
}
-static int msg_add_queue(struct hotplug_msg *msg)
+/* receive the kernel user event message and do some sanity checks */
+static struct uevent_msg *get_netlink_msg(void)
{
- struct hotplug_msg *new_msg;
- struct hotplug_msg *tmp_msg;
+ struct uevent_msg *msg;
+ int bufpos;
+ ssize_t size;
+ static char buffer[UEVENT_BUFFER_SIZE + 512];
+ char *pos;
+
+ size = recv(uevent_netlink_sock, &buffer, sizeof(buffer), 0);
+ if (size < 0) {
+ if (errno != EINTR)
+ err("unable to receive udevd message");
+ return NULL;
+ }
- new_msg = malloc(sizeof(*new_msg));
- if (new_msg == NULL) {
- dbg("error malloc");
- return -ENOMEM;
+ if ((size_t)size > sizeof(buffer)-1)
+ size = sizeof(buffer)-1;
+ buffer[size] = '\0';
+ dbg("uevent_size=%zi", size);
+
+ /* start of event payload */
+ bufpos = strlen(buffer)+1;
+ msg = get_msg_from_envbuf(&buffer[bufpos], size-bufpos);
+ if (msg == NULL)
+ return NULL;
+ msg->type = UDEVD_UEVENT_NETLINK;
+
+ /* validate message */
+ pos = strchr(buffer, '@');
+ if (pos == NULL) {
+ err("invalid uevent '%s'", buffer);
+ free(msg);
+ return NULL;
}
- memcpy(new_msg, msg, sizeof(*new_msg));
+ pos[0] = '\0';
- /* store timestamp of queuing */
- new_msg->queue_time = time(NULL);
+ if (msg->action == NULL) {
+ err("no ACTION in payload found, skip event '%s'", buffer);
+ free(msg);
+ return NULL;
+ }
- /* sort message by sequence number into list*/
- list_for_each_entry(tmp_msg, &msg_list, list)
- if (tmp_msg->seqnum > new_msg->seqnum)
+ if (strcmp(msg->action, buffer) != 0) {
+ err("ACTION in payload does not match uevent, skip event '%s'", buffer);
+ free(msg);
+ return NULL;
+ }
+
+ return msg;
+}
+
+static void asmlinkage sig_handler(int signum)
+{
+ switch (signum) {
+ case SIGINT:
+ case SIGTERM:
+ udev_exit = 1;
+ break;
+ case SIGALRM:
+ /* set flag, then write to pipe if needed */
+ run_msg_q = 1;
break;
- list_add_tail(&new_msg->list, &tmp_msg->list);
+ case SIGCHLD:
+ /* set flag, then write to pipe if needed */
+ sigchilds_waiting = 1;
+ break;
+ }
- return 0;
+ /* write to pipe, which will wakeup select() in our mainloop */
+ write(signal_pipe[WRITE_END], "", 1);
}
-static void work(void)
+static void udev_done(int pid)
{
- struct hotplug_msg *msg;
- int msgid;
- key_t key;
- char buf[BUFFER_SIZE];
- int ret;
-
- key = ftok(UDEVD_BIN, IPC_KEY_ID);
- msg = (struct hotplug_msg *) buf;
- msgid = msgget(key, IPC_CREAT);
- if (msgid == -1) {
- dbg("open message queue error");
- exit(1);
+ /* find msg associated with pid and delete it */
+ struct uevent_msg *msg;
+ struct sysinfo info;
+
+ list_for_each_entry(msg, &running_list, node) {
+ if (msg->pid == pid) {
+ sysinfo(&info);
+ if (msg->queue_time)
+ info("seq %llu, pid [%d] exit, %ld seconds old", msg->seqnum, msg->pid, info.uptime - msg->queue_time);
+ else
+ info("seq 0, pid [%d] exit", msg->pid);
+ msg_queue_delete(msg);
+
+ /* we want to run the exec queue manager since there may
+ * be events waiting with the devpath of the one that
+ * just finished
+ */
+ run_exec_q = 1;
+ return;
+ }
}
+}
+
+static void reap_sigchilds(void)
+{
+ pid_t pid;
+
while (1) {
- ret = msgrcv(msgid, (struct msgbuf *) buf, BUFFER_SIZE-4, HOTPLUGMSGTYPE, 0);
- if (ret != -1) {
- dbg("received sequence %d, expected sequence %d", msg->seqnum, expect_seqnum);
- if (msg->seqnum >= expect_seqnum) {
- msg_add_queue(msg);
- msg_dump_queue();
- msg_check_queue();
- continue;
- }
- dbg("too late for event with sequence %d, event skipped ", msg->seqnum);
- } else {
- if (errno == EINTR) {
- msg_check_queue();
- msg_dump_queue();
- delayed_check_queue();
- delayed_dump_queue();
- continue;
- }
- dbg("ipc message receive error '%s'", strerror(errno));
- }
+ pid = waitpid(-1, NULL, WNOHANG);
+ if (pid <= 0)
+ break;
+ udev_done(pid);
}
}
-static int one_and_only(void)
+static int init_udevd_socket(void)
{
- char string[100];
+ struct sockaddr_un saddr;
+ const int buffersize = 1024 * 1024;
+ socklen_t addrlen;
+ const int feature_on = 1;
+ int retval;
+
+ memset(&saddr, 0x00, sizeof(saddr));
+ saddr.sun_family = AF_LOCAL;
+ /* use abstract namespace for socket path */
+ strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH);
+ addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
+
+ udevd_sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
+ if (udevd_sock == -1) {
+ err("error getting socket, %s", strerror(errno));
+ return -1;
+ }
- lock_file = open(lock_filename, O_RDWR | O_CREAT, 0x640);
+ /* set receive buffersize */
+ setsockopt(udevd_sock, SOL_SOCKET, SO_RCVBUF, &buffersize, sizeof(buffersize));
- /* see if we can open */
- if (lock_file < 0)
+ /* the bind takes care of ensuring only one copy running */
+ retval = bind(udevd_sock, (struct sockaddr *) &saddr, addrlen);
+ if (retval < 0) {
+ err("bind failed, %s", strerror(errno));
+ close(udevd_sock);
return -1;
-
- /* see if we can lock */
- if (lockf(lock_file, F_TLOCK, 0) < 0) {
- close(lock_file);
+ }
+
+ /* enable receiving of the sender credentials */
+ setsockopt(udevd_sock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on));
+
+ return 0;
+}
+
+static int init_uevent_netlink_sock(void)
+{
+ struct sockaddr_nl snl;
+ const int buffersize = 1024 * 1024;
+ int retval;
+
+ memset(&snl, 0x00, sizeof(struct sockaddr_nl));
+ snl.nl_family = AF_NETLINK;
+ snl.nl_pid = getpid();
+ snl.nl_groups = 0xffffffff;
+
+ uevent_netlink_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
+ if (uevent_netlink_sock == -1) {
+ err("error getting socket, %s", strerror(errno));
return -1;
}
- snprintf(string, sizeof(string), "%d\n", getpid());
- write(lock_file, string, strlen(string));
+ /* set receive buffersize */
+ setsockopt(uevent_netlink_sock, SOL_SOCKET, SO_RCVBUF, &buffersize, sizeof(buffersize));
+
+ retval = bind(uevent_netlink_sock, (struct sockaddr *) &snl,
+ sizeof(struct sockaddr_nl));
+ if (retval < 0) {
+ err("bind failed, %s", strerror(errno));
+ close(uevent_netlink_sock);
+ uevent_netlink_sock = -1;
+ return -1;
+ }
return 0;
}
-int main(int argc, char *argv[])
+int main(int argc, char *argv[], char *envp[])
{
- /* only let one version of the daemon run at any one time */
- if (one_and_only() != 0)
- exit(0);
-
- /* set up signal handler */
- signal(SIGINT, sig_handler);
- signal(SIGTERM, sig_handler);
- signal(SIGALRM, sig_handler);
- signal(SIGCHLD, sig_handler);
-
- work();
- exit(0);
+ int retval;
+ int devnull;
+ struct sigaction act;
+ fd_set readfds;
+ const char *value;
+ int uevent_netlink_active = 0;
+ int daemonize = 0;
+ int i;
+
+ /* set std fd's to /dev/null, if the kernel forks us, we don't have them at all */
+ devnull = open("/dev/null", O_RDWR);
+ if (devnull >= 0) {
+ if (devnull != STDIN_FILENO)
+ dup2(devnull, STDIN_FILENO);
+ if (devnull != STDOUT_FILENO)
+ dup2(devnull, STDOUT_FILENO);
+ if (devnull != STDERR_FILENO)
+ dup2(devnull, STDERR_FILENO);
+ if (devnull > STDERR_FILENO)
+ close(devnull);
+ }
+
+ logging_init("udevd");
+ if (devnull < 0)
+ err("fatal, could not open /dev/null");
+
+ udev_init_config();
+ dbg("version %s", UDEV_VERSION);
+
+ if (getuid() != 0) {
+ err("need to be root, exit");
+ goto exit;
+ }
+
+ for (i = 1 ; i < argc; i++) {
+ char *arg = argv[i];
+ if (strcmp(arg, "--daemon") == 0 || strcmp(arg, "-d") == 0) {
+ info("will daemonize");
+ daemonize = 1;
+ }
+ if (strcmp(arg, "--stop-exec-queue") == 0) {
+ info("will not execute events until START_EXEC_QUEUE is received");
+ stop_exec_q = 1;
+ }
+ }
+
+ if (daemonize) {
+ pid_t pid;
+
+ pid = fork();
+ switch (pid) {
+ case 0:
+ dbg("damonized fork running");
+ break;
+ case -1:
+ err("fork of daemon failed");
+ goto exit;
+ default:
+ logging_close();
+ exit(0);
+ }
+ }
+
+ /* become session leader */
+ sid = setsid();
+ dbg("our session is %d", sid);
+
+ chdir("/");
+ umask(umask(077) | 022);
+
+ /* set a reasonable scheduling priority for the daemon */
+ setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
+
+ /* setup signal handler pipe */
+ retval = pipe(signal_pipe);
+ if (retval < 0) {
+ err("error getting pipes: %s", strerror(errno));
+ goto exit;
+ }
+ retval = fcntl(signal_pipe[READ_END], F_SETFL, O_NONBLOCK);
+ if (retval < 0) {
+ err("error fcntl on read pipe: %s", strerror(errno));
+ goto exit;
+ }
+ retval = fcntl(signal_pipe[READ_END], F_SETFD, FD_CLOEXEC);
+ if (retval < 0)
+ err("error fcntl on read pipe: %s", strerror(errno));
+ retval = fcntl(signal_pipe[WRITE_END], F_SETFL, O_NONBLOCK);
+ if (retval < 0) {
+ err("error fcntl on write pipe: %s", strerror(errno));
+ goto exit;
+ }
+ retval = fcntl(signal_pipe[WRITE_END], F_SETFD, FD_CLOEXEC);
+ if (retval < 0)
+ err("error fcntl on write pipe: %s", strerror(errno));
+
+ /* set signal handlers */
+ memset(&act, 0x00, sizeof(struct sigaction));
+ act.sa_handler = (void (*)(int)) sig_handler;
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = SA_RESTART;
+ sigaction(SIGINT, &act, NULL);
+ sigaction(SIGTERM, &act, NULL);
+ sigaction(SIGALRM, &act, NULL);
+ sigaction(SIGCHLD, &act, NULL);
+ sigaction(SIGHUP, &act, NULL);
+
+ if (init_udevd_socket() < 0) {
+ if (errno == EADDRINUSE)
+ dbg("another udevd running, exit");
+ else
+ dbg("error initialising udevd socket: %s", strerror(errno));
+
+ goto exit;
+ }
+
+ if (init_uevent_netlink_sock() < 0)
+ info("uevent socket not available");
+
+ /* override of forked udev binary, used for testing */
+ udev_bin = getenv("UDEV_BIN");
+ if (udev_bin != NULL)
+ info("udev binary is set to '%s'", udev_bin);
+ else
+ udev_bin = UDEV_BIN;
+
+ /* init of expected_seqnum value */
+ value = getenv("UDEVD_EXPECTED_SEQNUM");
+ if (value) {
+ expected_seqnum = strtoull(value, NULL, 10);
+ info("initialize expected_seqnum to %llu", expected_seqnum);
+ }
+
+ /* timeout to wait for missing events */
+ value = getenv("UDEVD_EVENT_TIMEOUT");
+ if (value)
+ event_timeout = strtoul(value, NULL, 10);
+ else
+ event_timeout = UDEVD_EVENT_TIMEOUT;
+ info("initialize event_timeout to %u", event_timeout);
+
+ /* maximum limit of forked childs */
+ value = getenv("UDEVD_MAX_CHILDS");
+ if (value)
+ max_childs = strtoul(value, NULL, 10);
+ else
+ max_childs = UDEVD_MAX_CHILDS;
+ info("initialize max_childs to %u", max_childs);
+
+ /* start to throttle forking if maximum number of _running_ childs is reached */
+ value = getenv("UDEVD_MAX_CHILDS_RUNNING");
+ if (value)
+ max_childs_running = strtoull(value, NULL, 10);
+ else
+ max_childs_running = UDEVD_MAX_CHILDS_RUNNING;
+ info("initialize max_childs_running to %u", max_childs_running);
+
+ /* export log_priority , as called programs may want to follow that setting */
+ sprintf(log, "UDEV_LOG=%i", udev_log_priority);
+ putenv(log);
+
+ while (!udev_exit) {
+ struct uevent_msg *msg;
+ int fdcount;
+
+ FD_ZERO(&readfds);
+ FD_SET(signal_pipe[READ_END], &readfds);
+ FD_SET(udevd_sock, &readfds);
+ if (uevent_netlink_sock > 0)
+ FD_SET(uevent_netlink_sock, &readfds);
+
+ fdcount = select(UDEV_MAX(udevd_sock, uevent_netlink_sock)+1, &readfds, NULL, NULL, NULL);
+ if (fdcount < 0) {
+ if (errno != EINTR)
+ dbg("error in select: %s", strerror(errno));
+ continue;
+ }
+
+ /* get user socket message */
+ if (FD_ISSET(udevd_sock, &readfds)) {
+ msg = get_udevd_msg();
+ if (msg) {
+ /* discard kernel messages if netlink is active */
+ if (uevent_netlink_active && msg->type == UDEVD_UEVENT_UDEVSEND && msg->seqnum != 0) {
+ info("skip uevent_helper message with SEQNUM, netlink is active");
+ free(msg);
+ } else
+ msg_queue_insert(msg);
+ }
+ }
+
+ /* get kernel netlink message */
+ if ((uevent_netlink_sock > 0) && FD_ISSET(uevent_netlink_sock, &readfds)) {
+ msg = get_netlink_msg();
+ if (msg) {
+ msg_queue_insert(msg);
+ /* disable udevsend with first netlink message */
+ if (!uevent_netlink_active) {
+ info("uevent_nl message received, disable udevsend messages");
+ uevent_netlink_active = 1;
+ }
+ }
+ }
+
+ /* received a signal, clear our notification pipe */
+ if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
+ char buf[256];
+
+ read(signal_pipe[READ_END], &buf, sizeof(buf));
+ }
+
+ /* forked child have returned */
+ if (sigchilds_waiting) {
+ sigchilds_waiting = 0;
+ reap_sigchilds();
+ }
+
+ if (run_msg_q) {
+ run_msg_q = 0;
+ msg_queue_manager();
+ }
+
+ if (run_exec_q) {
+ /* clean up running_list before calling exec_queue_manager() */
+ if (sigchilds_waiting) {
+ sigchilds_waiting = 0;
+ reap_sigchilds();
+ }
+
+ run_exec_q = 0;
+ if (!stop_exec_q)
+ exec_queue_manager();
+ }
+ }
+
+exit:
+ if (signal_pipe[READ_END] > 0)
+ close(signal_pipe[READ_END]);
+ if (signal_pipe[WRITE_END] > 0)
+ close(signal_pipe[WRITE_END]);
+
+ if (udevd_sock > 0)
+ close(udevd_sock);
+ if (uevent_netlink_sock > 0)
+ close(uevent_netlink_sock);
+
+ logging_close();
+
+ return 0;
}