/*
- * udevd.c
+ * udevd.c - hotplug event 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 <sys/types.h>
-#include <sys/ipc.h>
-#include <sys/wait.h>
-#include <sys/msg.h>
+#include <stddef.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 <sys/sysinfo.h>
+#include <sys/stat.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"
-#define BUFFER_SIZE 1024
-#define EVENT_TIMEOUT_SECONDS 10
-#define DAEMON_TIMEOUT_SECONDS 30
-
+/* global variables*/
+static int udevsendsock;
+static int ueventsock;
+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 volatile int sig_flag;
+static int run_exec_q;
+
+static LIST_HEAD(msg_list);
+static LIST_HEAD(exec_list);
+static LIST_HEAD(running_list);
+
+static void exec_queue_manager(void);
+static void msg_queue_manager(void);
+static void user_sighandler(void);
+static void reap_sigchilds(void);
+char *udev_bin;
+
+#ifdef USE_LOG
+void log_message (int priority, const char *format, ...)
+{
+ va_list args;
-static int expect_seqnum = 0;
-static struct hotplug_msg *head = NULL;
+ if (priority > udev_log_priority)
+ return;
+ va_start(args, format);
+ vsyslog(priority, format, args);
+ va_end(args);
+}
+#endif
-static void sig_alarmhandler(int signum)
+static void msg_dump_queue(void)
{
- dbg("caught signal %d", signum);
- switch (signum) {
- case SIGALRM:
- dbg("event timeout reached");
- break;
+#ifdef DEBUG
+ struct hotplug_msg *msg;
- default:
- dbg("unhandled signal");
- }
+ list_for_each_entry(msg, &msg_list, node)
+ dbg("sequence %llu in queue", msg->seqnum);
+#endif
}
-static void dump_queue(void)
+static void run_queue_delete(struct hotplug_msg *msg)
{
- struct hotplug_msg *p;
- p = head;
-
- dbg("next expected sequence is %d", expect_seqnum);
- while(p != NULL) {
- dbg("sequence %d in queue", p->seqnum);
- p = p->next;
- }
+ list_del(&msg->node);
+ free(msg);
}
-static void dump_msg(struct hotplug_msg *pmsg)
+/* orders the message in the queue by sequence number */
+static void msg_queue_insert(struct hotplug_msg *msg)
{
- dbg("sequence %d, '%s', '%s', '%s'",
- pmsg->seqnum, pmsg->action, pmsg->devpath, pmsg->subsystem);
+ struct hotplug_msg *loop_msg;
+ struct sysinfo info;
+
+ 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) {
+ dbg("ignoring duplicate message seq %llu", msg->seqnum);
+ free(msg);
+ return;
+ }
+ }
+
+ /* store timestamp of queuing */
+ sysinfo(&info);
+ msg->queue_time = info.uptime;
+
+ list_add(&msg->node, &loop_msg->node);
+ dbg("queued message seq %llu", msg->seqnum);
+
+ /* run msg queue manager */
+ run_msg_q = 1;
+
+ return;
}
-static int dispatch_msg(struct hotplug_msg *pmsg)
+/* forks event and removes event from run queue when finished */
+static void execute_udev(struct hotplug_msg *msg)
{
+ char *const argv[] = { "udev", msg->subsystem, NULL };
pid_t pid;
- char *argv[3];
- extern char **environ;
-
- dump_msg(pmsg);
-
- setenv("ACTION", pmsg->action, 1);
- setenv("DEVPATH", pmsg->devpath, 1);
- argv[0] = DEFAULT_UDEV_EXEC;
- argv[1] = pmsg->subsystem;
- argv[2] = NULL;
pid = fork();
switch (pid) {
case 0:
/* child */
- execve(argv[0], argv, environ);
- dbg("exec of child failed");
- exit(1);
+ if (ueventsock != -1)
+ close(ueventsock);
+ close(udevsendsock);
+ logging_close();
+
+ 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");
- return -1;
+ err("fork of child failed");
+ run_queue_delete(msg);
+ break;
default:
- wait(0);
+ /* get SIGCHLD in main loop */
+ dbg("==> exec seq %llu [%d] working at '%s'", msg->seqnum, pid, msg->devpath);
+ msg->pid = pid;
}
- return 0;
}
-static void set_timer(int seconds)
+static int running_processes(void)
{
- signal(SIGALRM, sig_alarmhandler);
- alarm(seconds);
-}
+ int f;
+ static char buf[4096];
+ int len;
+ int running;
+ const char *pos;
+
+ f = open("/proc/stat", O_RDONLY);
+ if (f == -1)
+ return -1;
-static void check_queue(void)
-{
- struct hotplug_msg *p;
- p = head;
-
- dump_queue();
- while(head != NULL && head->seqnum == expect_seqnum) {
- dispatch_msg(head);
- expect_seqnum++;
- p = head;
- head = head->next;
- free(p);
- }
- if (head != NULL)
- set_timer(EVENT_TIMEOUT_SECONDS);
+ len = read(f, buf, sizeof(buf));
+ close(f);
+
+ if (len <= 0)
+ return -1;
else
- set_timer(DAEMON_TIMEOUT_SECONDS);
+ 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 void add_queue(struct hotplug_msg *pmsg)
+/* 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 *pnewmsg;
- struct hotplug_msg *p;
- struct hotplug_msg *p1;
-
- p = head;
- p1 = NULL;
- pnewmsg = malloc(sizeof(struct hotplug_msg));
- *pnewmsg = *pmsg;
- pnewmsg->next = NULL;
- while(p != NULL && pmsg->seqnum > p->seqnum) {
- p1 = p;
- p = p->next;
- }
- pnewmsg->next = p;
- if (p1 == NULL) {
- head = pnewmsg;
- } else {
- p1->next = pnewmsg;
- }
- dump_queue();
+ 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 lock_file = -1;
-static char *lock_filename = ".udevd_lock";
+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;
+}
-static int process_queue(void)
+/* 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)
{
- int msgid;
- key_t key;
- struct hotplug_msg *pmsg;
- char buf[BUFFER_SIZE];
- int ret;
-
- key = ftok(DEFAULT_UDEVD_EXEC, IPC_KEY_ID);
- pmsg = (struct hotplug_msg *) buf;
- msgid = msgget(key, IPC_CREAT);
- if (msgid == -1) {
- dbg("open message queue error");
- return -1;
+ struct hotplug_msg *loop_msg;
+
+ 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;
+
+ /* 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;
}
- while (1) {
- ret = msgrcv(msgid, (struct msgbuf *) buf, BUFFER_SIZE-4, HOTPLUGMSGTYPE, 0);
- if (ret != -1) {
- dbg("current sequence %d, expected sequence %d", pmsg->seqnum, expect_seqnum);
-
- /* init expected sequence with value from first call */
- if (expect_seqnum == 0) {
- expect_seqnum = pmsg->seqnum;
- dbg("init next expected sequence number to %d", expect_seqnum);
- }
- if (pmsg->seqnum > expect_seqnum) {
- add_queue(pmsg);
- set_timer(EVENT_TIMEOUT_SECONDS);
- } else {
- if (pmsg->seqnum == expect_seqnum) {
- dispatch_msg(pmsg);
- expect_seqnum++;
- check_queue();
- } else {
- dbg("timeout event for unexpected sequence number %d", pmsg->seqnum);
- }
+ return NULL;
+}
+
+/* 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;
}
+ }
+
+ msg = running_with_devpath(loop_msg);
+ if (!msg) {
+ /* move event to run list */
+ list_move_tail(&loop_msg->node, &running_list);
+ execute_udev(loop_msg);
+ running++;
+ dbg("moved seq %llu to running list", loop_msg->seqnum);
} else {
- if (errno == EINTR) {
- if (head != NULL) {
- /* event timeout, skip all missing, proceed with next queued event */
- info("timeout reached, skip events %d - %d", expect_seqnum, head->seqnum-1);
- expect_seqnum = head->seqnum;
- } else {
- info("we have nothing to do, so daemon exits...");
- if (lock_file >= 0) {
- close(lock_file);
- unlink(lock_filename);
- }
- exit(0);
- }
- check_queue();
- } else {
- dbg("ipc message receive error '%s'", strerror(errno));
- }
+ dbg("delay seq %llu (%s), cause seq %llu (%s) is still running",
+ loop_msg->seqnum, loop_msg->devpath, msg->seqnum, msg->devpath);
}
}
- return 0;
}
-static void sig_handler(int signum)
+static void msg_move_exec(struct hotplug_msg *msg)
+{
+ 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);
+}
+
+/* msg queue management routine handles the timeouts and dispatches the events */
+static void msg_queue_manager(void)
+{
+ struct hotplug_msg *loop_msg;
+ 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, 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 >= timeout) {
+ msg_move_exec(loop_msg);
+ goto recheck;
+ } else {
+ break;
+ }
+ }
+
+ msg_dump_queue();
+
+ /* set timeout for remaining queued events */
+ if (list_empty(&msg_list) == 0) {
+ struct itimerval itv = {{0, 0}, {timeout - msg_age, 0}};
+ dbg("next event expires in %li seconds", timeout - msg_age);
+ setitimer(ITIMER_REAL, &itv, NULL);
+ }
+}
+
+static struct hotplug_msg *get_msg_from_envbuf(const char *buf, int buf_size)
{
- dbg("caught signal %d", signum);
+ int bufpos;
+ int i;
+ struct hotplug_msg *msg;
+
+ msg = malloc(sizeof(struct hotplug_msg) + buf_size);
+ if (msg == NULL)
+ return NULL;
+ memset(msg, 0x00, sizeof(struct hotplug_msg) + buf_size);
+
+ /* copy environment buffer and reconstruct envp */
+ memcpy(msg->envbuf, buf, buf_size);
+ bufpos = 0;
+ for (i = 0; (bufpos < buf_size) && (i < HOTPLUG_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];
+
+ if (strncmp(key, "DEVPATH=", 8) == 0)
+ msg->devpath = &key[8];
+
+ if (strncmp(key, "SUBSYSTEM=", 10) == 0)
+ msg->subsystem = &key[10];
+
+ if (strncmp(key, "SEQNUM=", 7) == 0)
+ msg->seqnum = strtoull(&key[7], NULL, 10);
+
+ 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;
+
+ return msg;
+}
+
+/* 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;
+ 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;
+
+ memset(&usend_msg, 0x00, sizeof(struct udevsend_msg));
+ iov.iov_base = &usend_msg;
+ iov.iov_len = sizeof(struct udevsend_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(udevsendsock, &smsg, 0);
+ if (size < 0) {
+ if (errno != EINTR)
+ 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) {
+ info("no sender credentials received, message ignored");
+ return NULL;
+ }
+
+ if (cred->uid != 0) {
+ info("sender uid=%i, message ignored", cred->uid);
+ return NULL;
+ }
+
+ if (strncmp(usend_msg.magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
+ 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 = get_msg_from_envbuf(usend_msg.envbuf, envbuf_size);
+ if (msg == NULL)
+ return NULL;
+
+ return msg;
+}
+
+/* receive the kernel user event message and do some sanity checks */
+static struct hotplug_msg *get_uevent_msg(void)
+{
+ struct hotplug_msg *msg;
+ int bufpos;
+ ssize_t size;
+ static char buffer[HOTPLUG_BUFFER_SIZE + 512];
+ char *pos;
+
+ size = recv(ueventsock, &buffer, sizeof(buffer), 0);
+ if (size < 0) {
+ if (errno != EINTR)
+ dbg("unable to receive udevsend message");
+ return NULL;
+ }
+
+ if ((size_t)size > sizeof(buffer)-1)
+ size = sizeof(buffer)-1;
+ buffer[size] = '\0';
+ dbg("uevent_size=%i", size);
+
+ /* start of event payload */
+ bufpos = strlen(buffer)+1;
+ msg = get_msg_from_envbuf(&buffer[bufpos], size-bufpos);
+ if (msg == NULL)
+ return NULL;
+
+ /* validate message */
+ pos = strchr(buffer, '@');
+ if (pos == NULL) {
+ dbg("invalid uevent '%s'", buffer);
+ free(msg);
+ return NULL;
+ }
+ pos[0] = '\0';
+
+ if (msg->action == NULL) {
+ dbg("no ACTION in payload found, skip event '%s'", buffer);
+ free(msg);
+ return NULL;
+ }
+
+ if (strcmp(msg->action, buffer) != 0) {
+ dbg("ACTION in payload does not match uevent, skip event '%s'", buffer);
+ free(msg);
+ return NULL;
+ }
+
+ return msg;
+}
+
+static void asmlinkage sig_handler(int signum)
+{
+ int rc;
+
switch (signum) {
case SIGINT:
case SIGTERM:
- case SIGKILL:
- if (lock_file >= 0) {
- close(lock_file);
- unlink(lock_filename);
- }
exit(20 + signum);
break;
+ case SIGALRM:
+ /* set flag, then write to pipe if needed */
+ run_msg_q = 1;
+ goto do_write;
+ break;
+ case SIGCHLD:
+ /* set flag, then write to pipe if needed */
+ sigchilds_waiting = 1;
+ goto do_write;
+ break;
+ }
- default:
- dbg("unhandled signal");
+do_write:
+ /* if pipe is empty, write to pipe to force select to return
+ * immediately when it gets called
+ */
+ if (!sig_flag) {
+ rc = write(pipefds[1],&signum,sizeof(signum));
+ if (rc >= 0)
+ sig_flag = 1;
+ }
+}
+
+static void udev_done(int pid)
+{
+ /* find msg associated with pid and delete it */
+ struct hotplug_msg *msg;
+
+ list_for_each_entry(msg, &running_list, node) {
+ if (msg->pid == pid) {
+ dbg("<== exec seq %llu came back", msg->seqnum);
+ run_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)
+{
+ while(1) {
+ int pid = waitpid(-1, NULL, WNOHANG);
+ if ((pid == -1) || (pid == 0))
+ break;
+ udev_done(pid);
}
}
-static int one_and_only(void)
+/* just read everything from the pipe and clear the flag,
+ * the flags was set in the signal handler
+ */
+static void user_sighandler(void)
{
- char string[100];
+ int sig;
- lock_file = open(lock_filename, O_RDWR | O_CREAT, 0x640);
+ while(1) {
+ int rc = read(pipefds[0], &sig, sizeof(sig));
+ if (rc < 0)
+ break;
- /* see if we can open */
- if (lock_file < 0)
- return -EINVAL;
-
- /* see if we can lock */
- if (lockf(lock_file, F_TLOCK, 0) < 0) {
- close(lock_file);
- unlink(lock_filename);
- return -EINVAL;
+ sig_flag = 0;
+ }
+}
+
+static int init_udevsend_socket(void)
+{
+ struct sockaddr_un saddr;
+ 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;
+
+ 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;
}
- snprintf(string, sizeof(string), "%d\n", getpid());
- write(lock_file, string, strlen(string));
-
+ /* 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[])
+static int init_uevent_socket(void)
{
- /* only let one version of the daemon run at any one time */
- if (one_and_only() != 0)
- exit(0);
+ struct sockaddr_nl snl;
+ int retval;
- /* set up signal handler */
- signal(SIGINT, sig_handler);
- signal(SIGTERM, sig_handler);
- signal(SIGKILL, sig_handler);
+ memset(&snl, 0x00, sizeof(struct sockaddr_nl));
+ snl.nl_family = AF_NETLINK;
+ snl.nl_pid = getpid();
+ snl.nl_groups = 0xffffffff;
- /* we exit if we have nothing to do, next event will start us again */
- set_timer(DAEMON_TIMEOUT_SECONDS);
+ ueventsock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
+ if (ueventsock == -1) {
+ dbg("error getting socket, %s", strerror(errno));
+ return -1;
+ }
+
+ retval = bind(ueventsock, (struct sockaddr *) &snl,
+ sizeof(struct sockaddr_nl));
+ if (retval < 0) {
+ dbg("bind failed, %s", strerror(errno));
+ close(ueventsock);
+ ueventsock = -1;
+ return -1;
+ }
- /* main loop */
- process_queue();
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;
+ int uevent_active = 0;
+
+ logging_init("udevd");
+ udev_init_config();
+ dbg("version %s", UDEV_VERSION);
+
+ if (getuid() != 0) {
+ 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) {
+ 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) {
+ err("error getting pipes: %s", strerror(errno));
+ goto exit;
+ }
+
+ retval = fcntl(pipefds[0], F_SETFL, O_NONBLOCK);
+ if (retval < 0) {
+ err("error fcntl on read pipe: %s", strerror(errno));
+ goto exit;
+ }
+ retval = fcntl(pipefds[0], F_SETFD, FD_CLOEXEC);
+ if (retval < 0)
+ err("error fcntl on read pipe: %s", strerror(errno));
+
+ retval = fcntl(pipefds[1], F_SETFL, O_NONBLOCK);
+ if (retval < 0) {
+ err("error fcntl on write pipe: %s", strerror(errno));
+ goto exit;
+ }
+ retval = fcntl(pipefds[1], 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);
+
+ if (init_uevent_socket() < 0) {
+ dbg("uevent socket not available");
+ }
+
+ if (init_udevsend_socket() < 0) {
+ if (errno == EADDRINUSE)
+ dbg("another udevd running, exit");
+ else
+ dbg("error initialising udevsend socket: %s", strerror(errno));
+
+ goto exit;
+ }
+
+ /* possible override of 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;
+
+ /* 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);
+ if (ueventsock != -1)
+ FD_SET(ueventsock, &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);
+
+ if (retval < 0) {
+ if (errno != EINTR)
+ dbg("error in select: %s", strerror(errno));
+ continue;
+ }
+
+ if (FD_ISSET(udevsendsock, &workreadfds)) {
+ msg = get_udevsend_msg();
+ if (msg) {
+ /* discard kernel messages if netlink is active */
+ if (uevent_active && msg->seqnum != 0) {
+ dbg("skip kernel udevsend message, netlink is active");
+ free(msg);
+ continue;
+ }
+ msg_queue_insert(msg);
+ }
+ }
+
+ if (FD_ISSET(ueventsock, &workreadfds)) {
+ msg = get_uevent_msg();
+ if (msg) {
+ msg_queue_insert(msg);
+ /* disable udevsend with first netlink message */
+ if (!uevent_active) {
+ info("netlink message received, disable kernel udevsend messages");
+ uevent_active = 1;
+ }
+ }
+ }
+
+ if (FD_ISSET(pipefds[0], &workreadfds))
+ user_sighandler();
+
+ 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;
+ exec_queue_manager();
+ }
+ }
+
+exit:
+ logging_close();
+ return 1;
+}
~ianmdlvl / elogind.git / blobdiff