/*
* udevd.c - hotplug event serializer
*
- * 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>
*
*
*/
#include <stddef.h>
-#include <sys/wait.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <fcntl.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 <fcntl.h>
#include <sys/sysinfo.h>
#include <sys/stat.h>
#include "list.h"
+#include "udev_libc_wrapper.h"
#include "udev.h"
#include "udev_version.h"
#include "udev_utils.h"
/* global variables*/
static int udevsendsock;
+static pid_t sid;
static int pipefds[2];
+static long startup_time;
static unsigned long long expected_seqnum = 0;
static volatile int sigchilds_waiting;
static volatile int run_msg_q;
static void reap_sigchilds(void);
char *udev_bin;
-#ifdef LOG
-unsigned char logname[LOGNAME_SIZE];
-void log_message (int level, const char *format, ...)
+#ifdef USE_LOG
+void log_message (int priority, const char *format, ...)
{
- va_list args;
+ va_list args;
+
+ if (priority > udev_log_priority)
+ return;
va_start(args, format);
- vsyslog(level, format, args);
+ vsyslog(priority, format, args);
va_end(args);
}
#endif
-#define msg_dump(msg) \
- dbg("msg_dump: sequence %llu, '%s', '%s', '%s'", \
- msg->seqnum, msg->action, msg->devpath, msg->subsystem);
-
static void msg_dump_queue(void)
{
#ifdef DEBUG
struct hotplug_msg *msg;
- list_for_each_entry(msg, &msg_list, list)
+ list_for_each_entry(msg, &msg_list, node)
dbg("sequence %llu in queue", msg->seqnum);
#endif
}
static void run_queue_delete(struct hotplug_msg *msg)
{
- list_del(&msg->list);
+ list_del(&msg->node);
free(msg);
}
struct hotplug_msg *loop_msg;
struct sysinfo info;
- /* sort message by sequence number into list. events
- * will tend to come in order, so scan the list backwards
- */
- list_for_each_entry_reverse(loop_msg, &msg_list, list)
+ if (msg->seqnum == 0) {
+ dbg("no SEQNUM, move straight to the exec queue");
+ list_add(&msg->node, &exec_list);
+ run_exec_q = 1;
+ return;
+ }
+
+ /* don't delay messages with timeout set */
+ if (msg->timeout) {
+ dbg("move seq %llu with timeout %u to exec queue", msg->seqnum, msg->timeout);
+ list_add(&msg->node, &exec_list);
+ run_exec_q = 1;
+ return;
+ }
+
+ /* 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) {
+ info("ignoring duplicate message seq %llu", msg->seqnum);
+ return;
+ }
+ }
+
/* store timestamp of queuing */
sysinfo(&info);
msg->queue_time = info.uptime;
- list_add(&msg->list, &loop_msg->list);
+ list_add(&msg->node, &loop_msg->node);
dbg("queued message seq %llu", msg->seqnum);
/* run msg queue manager */
run_msg_q = 1;
- return ;
+ return;
}
/* forks event and removes event from run queue when finished */
static void udev_run(struct hotplug_msg *msg)
{
+ char *const argv[] = { "udev", msg->subsystem, NULL };
pid_t pid;
pid = fork();
/* child */
close(udevsendsock);
logging_close();
- execle(udev_bin, "udev", msg->subsystem, NULL, msg->envp);
- dbg("exec of child failed");
+
+ setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
+ execve(udev_bin, argv, msg->envp);
+ err("exec of child failed");
_exit(1);
break;
case -1:
- dbg("fork of child failed");
+ err("fork of child failed");
run_queue_delete(msg);
- /* note: we never managed to run, so we had no impact on
- * running_with_devpath(), so don't bother setting run_exec_q
- */
break;
default:
/* get SIGCHLD in main loop */
}
}
-/* returns already running task with devpath */
+static int running_processes(void)
+{
+ 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));
+ 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;
+}
+
+/* return the number of process es in our session, count only until limit */
+static int running_processes_in_session(pid_t session, int limit)
+{
+ 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));
+ 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 int compare_devpath(const char *running, const char *waiting)
+{
+ 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;
+ }
+
+ return 0;
+}
+
+/* returns still running task for the same device, its parent or its physical device */
static struct hotplug_msg *running_with_devpath(struct hotplug_msg *msg)
{
struct hotplug_msg *loop_msg;
- list_for_each_entry(loop_msg, &running_list, list) {
- if (loop_msg->devpath == NULL || msg->devpath == NULL)
+
+ if (msg->devpath == NULL)
+ return NULL;
+
+ /* skip any events with a timeout set */
+ if (msg->timeout)
+ return NULL;
+
+ list_for_each_entry(loop_msg, &running_list, node) {
+ if (loop_msg->devpath == NULL)
continue;
- if (strcmp(loop_msg->devpath, msg->devpath) == 0)
+ /* return running parent/child device event */
+ if (compare_devpath(loop_msg->devpath, msg->devpath) != 0)
return loop_msg;
+
+ /* return running physical device event */
+ if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0)
+ if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0)
+ return loop_msg;
}
return NULL;
}
-/* exec queue management routine executes the events and delays events for the same devpath */
+/* exec queue management routine executes the events and serializes events in the same sequence */
static void exec_queue_manager(void)
{
struct hotplug_msg *loop_msg;
struct hotplug_msg *tmp_msg;
struct hotplug_msg *msg;
+ int running;
+
+ running = running_processes();
+ dbg("%d processes runnning on system", running);
+ if (running < 0)
+ running = THROTTLE_MAX_RUNNING_CHILDS;
+
+ list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, node) {
+ /* check running processes in our session and possibly throttle */
+ if (running >= THROTTLE_MAX_RUNNING_CHILDS) {
+ running = running_processes_in_session(sid, THROTTLE_MAX_RUNNING_CHILDS+10);
+ dbg("%d processes running in session", running);
+ if (running >= THROTTLE_MAX_RUNNING_CHILDS) {
+ dbg("delay seq %llu, cause too many processes already running", loop_msg->seqnum);
+ return;
+ }
+ }
- list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, list) {
msg = running_with_devpath(loop_msg);
if (!msg) {
/* move event to run list */
- list_move_tail(&loop_msg->list, &running_list);
+ list_move_tail(&loop_msg->node, &running_list);
udev_run(loop_msg);
+ running++;
dbg("moved seq %llu to running list", loop_msg->seqnum);
} else {
- dbg("delay seq %llu, cause seq %llu already working on '%s'",
- loop_msg->seqnum, msg->seqnum, msg->devpath);
+ dbg("delay seq %llu (%s), cause seq %llu (%s) is still running",
+ loop_msg->seqnum, loop_msg->devpath, msg->seqnum, msg->devpath);
}
}
}
static void msg_move_exec(struct hotplug_msg *msg)
{
- list_move_tail(&msg->list, &exec_list);
+ 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",
struct hotplug_msg *tmp_msg;
struct sysinfo info;
long msg_age = 0;
+ static int timeout = EVENT_INIT_TIMEOUT_SEC;
+ static int init = 1;
dbg("msg queue manager, next expected is %llu", expected_seqnum);
recheck:
- list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, list) {
+ 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;
}
+ /* see if we are in the initialization phase and wait for the very first events */
+ if (init && (info.uptime - startup_time >= INIT_TIME_SEC)) {
+ init = 0;
+ timeout = EVENT_TIMEOUT_SEC;
+ dbg("initialization phase passed, set timeout to %i seconds", EVENT_TIMEOUT_SEC);
+ }
+
/* move event with expired timeout to the exec list */
sysinfo(&info);
msg_age = info.uptime - loop_msg->queue_time;
dbg("seq %llu is %li seconds old", loop_msg->seqnum, msg_age);
- if (msg_age > EVENT_TIMEOUT_SEC-1) {
+ if (msg_age >= timeout) {
msg_move_exec(loop_msg);
goto recheck;
} else {
/* set timeout for remaining queued events */
if (list_empty(&msg_list) == 0) {
- struct itimerval itv = {{0, 0}, {EVENT_TIMEOUT_SEC - msg_age, 0}};
- dbg("next event expires in %li seconds", EVENT_TIMEOUT_SEC - msg_age);
+ struct itimerval itv = {{0, 0}, {timeout - msg_age, 0}};
+ dbg("next event expires in %li seconds", timeout - msg_age);
setitimer(ITIMER_REAL, &itv, NULL);
}
}
-/* receive the msg, do some basic sanity checks, and queue it */
-static void handle_udevsend_msg(int sock)
+/* receive the udevsend message and do some sanity checks */
+static struct hotplug_msg *get_udevsend_msg(void)
{
static struct udevsend_msg usend_msg;
struct hotplug_msg *msg;
smsg.msg_control = cred_msg;
smsg.msg_controllen = sizeof(cred_msg);
- size = recvmsg(sock, &smsg, 0);
+ size = recvmsg(udevsendsock, &smsg, 0);
if (size < 0) {
if (errno != EINTR)
- dbg("unable to receive message");
- return;
+ dbg("unable to receive udevsend message");
+ return NULL;
}
cmsg = CMSG_FIRSTHDR(&smsg);
cred = (struct ucred *) CMSG_DATA(cmsg);
if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
- dbg("no sender credentials received, message ignored");
- goto exit;
+ info("no sender credentials received, message ignored");
+ return NULL;
}
if (cred->uid != 0) {
- dbg("sender uid=%i, message ignored", cred->uid);
- goto exit;
+ info("sender uid=%i, message ignored", cred->uid);
+ return NULL;
}
if (strncmp(usend_msg.magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
- dbg("message magic '%s' doesn't match, ignore it", usend_msg.magic);
- goto exit;
+ info("message magic '%s' doesn't match, ignore it", usend_msg.magic);
+ return NULL;
}
envbuf_size = size - offsetof(struct udevsend_msg, envbuf);
dbg("envbuf_size=%i", envbuf_size);
msg = malloc(sizeof(struct hotplug_msg) + envbuf_size);
+ if (msg == NULL)
+ return NULL;
+
memset(msg, 0x00, sizeof(struct hotplug_msg) + envbuf_size);
/* copy environment buffer and reconstruct envp */
if (strncmp(key, "SEQNUM=", 7) == 0)
msg->seqnum = strtoull(&key[7], NULL, 10);
- }
- msg->envp[i++] = "MANAGED_EVENT=1";
- msg->envp[i] = NULL;
- /* if no seqnum is given, we move straight to exec queue */
- if (msg->seqnum == 0) {
- list_add(&msg->list, &exec_list);
- run_exec_q = 1;
- } else {
- msg_queue_insert(msg);
+ if (strncmp(key, "PHYSDEVPATH=", 12) == 0)
+ msg->physdevpath = &key[12];
+
+ if (strncmp(key, "TIMEOUT=", 8) == 0)
+ msg->timeout = strtoull(&key[8], NULL, 10);
}
+ msg->envp[i++] = "UDEVD_EVENT=1";
+ msg->envp[i] = NULL;
-exit:
- return;
+ return msg;
}
static void asmlinkage sig_handler(int signum)
/* find msg associated with pid and delete it */
struct hotplug_msg *msg;
- list_for_each_entry(msg, &running_list, list) {
+ list_for_each_entry(msg, &running_list, node) {
if (msg->pid == pid) {
dbg("<== exec seq %llu came back", msg->seqnum);
run_queue_delete(msg);
static void user_sighandler(void)
{
int sig;
+
while(1) {
int rc = read(pipefds[0], &sig, sizeof(sig));
if (rc < 0)
}
}
-int main(int argc, char *argv[], char *envp[])
+static int init_udevsend_socket(void)
{
- int maxsockplus;
struct sockaddr_un saddr;
socklen_t addrlen;
- int retval, fd;
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;
+
+ udevsendsock = socket(AF_LOCAL, SOCK_DGRAM, 0);
+ if (udevsendsock == -1) {
+ err("error getting socket, %s", strerror(errno));
+ return -1;
+ }
+
+ /* the bind takes care of ensuring only one copy running */
+ retval = bind(udevsendsock, (struct sockaddr *) &saddr, addrlen);
+ if (retval < 0) {
+ err("bind failed, %s", strerror(errno));
+ close(udevsendsock);
+ return -1;
+ }
+
+ /* enable receiving of the sender credentials */
+ setsockopt(udevsendsock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on));
+
+ return 0;
+}
+
+int main(int argc, char *argv[], char *envp[])
+{
+ struct sysinfo info;
+ int maxsockplus;
+ int retval;
+ int fd;
struct sigaction act;
fd_set readfds;
+ const char *udevd_expected_seqnum;
logging_init("udevd");
+ udev_init_config();
dbg("version %s", UDEV_VERSION);
if (getuid() != 0) {
- dbg("need to be root, exit");
+ err("need to be root, exit");
goto exit;
}
+ /* daemonize on request */
+ if (argc == 2 && strcmp(argv[1], "-d") == 0) {
+ 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);
+
/* make sure we don't lock any path */
chdir("/");
umask(umask(077) | 022);
+ /*set a reasonable scheduling priority for the daemon */
+ setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
+
/* Set fds to dev/null */
fd = open( "/dev/null", O_RDWR );
- if ( fd < 0 ) {
- dbg("error opening /dev/null %s", strerror(errno));
- goto exit;
- }
- dup2(fd, 0);
- dup2(fd, 1);
- dup2(fd, 2);
- if (fd > 2)
- close(fd);
-
- /* become session leader */
- setsid();
+ if (fd >= 0) {
+ dup2(fd, 0);
+ dup2(fd, 1);
+ dup2(fd, 2);
+ if (fd > 2)
+ close(fd);
+ } else
+ err("error opening /dev/null %s", strerror(errno));
/* setup signal handler pipe */
retval = pipe(pipefds);
if (retval < 0) {
- dbg("error getting pipes: %s", strerror(errno));
+ err("error getting pipes: %s", strerror(errno));
goto exit;
}
retval = fcntl(pipefds[0], F_SETFL, O_NONBLOCK);
if (retval < 0) {
- dbg("error fcntl on read pipe: %s", strerror(errno));
+ err("error fcntl on read pipe: %s", strerror(errno));
goto exit;
}
retval = fcntl(pipefds[0], F_SETFD, FD_CLOEXEC);
- if (retval < 0) {
- dbg("error fcntl on read pipe: %s", strerror(errno));
- goto exit;
- }
+ if (retval < 0)
+ err("error fcntl on read pipe: %s", strerror(errno));
retval = fcntl(pipefds[1], F_SETFL, O_NONBLOCK);
if (retval < 0) {
- dbg("error fcntl on write pipe: %s", strerror(errno));
+ err("error fcntl on write pipe: %s", strerror(errno));
goto exit;
}
retval = fcntl(pipefds[1], F_SETFD, FD_CLOEXEC);
- if (retval < 0) {
- dbg("error fcntl on write pipe: %s", strerror(errno));
- goto exit;
- }
+ if (retval < 0)
+ err("error fcntl on write pipe: %s", strerror(errno));
/* set signal handlers */
- act.sa_handler = (void (*) (int))sig_handler;
+ 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(SIGALRM, &act, NULL);
sigaction(SIGCHLD, &act, NULL);
- 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;
-
- udevsendsock = socket(AF_LOCAL, SOCK_DGRAM, 0);
- if (udevsendsock == -1) {
- dbg("error getting socket, exit");
- goto exit;
- }
+ if (init_udevsend_socket() < 0) {
+ if (errno == EADDRINUSE)
+ dbg("another udevd running, exit");
+ else
+ dbg("error initialising udevsend socket: %s", strerror(errno));
- /* the bind takes care of ensuring only one copy running */
- retval = bind(udevsendsock, (struct sockaddr *) &saddr, addrlen);
- if (retval < 0) {
- dbg("bind failed, exit");
- close(udevsendsock);
goto exit;
}
- /* enable receiving of the sender credentials */
- setsockopt(udevsendsock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on));
-
/* possible override of udev binary, used for testing */
udev_bin = getenv("UDEV_BIN");
if (udev_bin != NULL)
- dbg("udev binary is set to '%s'", udev_bin);
+ info("udev binary is set to '%s'", udev_bin);
else
udev_bin = UDEV_BIN;
+ /* possible init of expected_seqnum value */
+ udevd_expected_seqnum = getenv("UDEVD_EXPECTED_SEQNUM");
+ if (udevd_expected_seqnum != NULL) {
+ expected_seqnum = strtoull(udevd_expected_seqnum, NULL, 10);
+ info("initialize expected_seqnum to %llu", expected_seqnum);
+ }
+
+ /* get current time to provide shorter timeout on startup */
+ sysinfo(&info);
+ startup_time = info.uptime;
+
FD_ZERO(&readfds);
FD_SET(udevsendsock, &readfds);
FD_SET(pipefds[0], &readfds);
maxsockplus = udevsendsock+1;
while (1) {
+ struct hotplug_msg *msg;
+
fd_set workreadfds = readfds;
retval = select(maxsockplus, &workreadfds, NULL, NULL, NULL);
continue;
}
- if (FD_ISSET(udevsendsock, &workreadfds))
- handle_udevsend_msg(udevsendsock);
+ if (FD_ISSET(udevsendsock, &workreadfds)) {
+ msg = get_udevsend_msg();
+ if (msg)
+ msg_queue_insert(msg);
+ }
if (FD_ISSET(pipefds[0], &workreadfds))
user_sighandler();
~ianmdlvl / elogind.git / blobdiff