#include <sys/socket.h>
#include <sys/un.h>
#include <sys/time.h>
+#include <fcntl.h>
#include "list.h"
#include "udev.h"
+#include "udev_lib.h"
#include "udev_version.h"
#include "udevd.h"
#include "logging.h"
+static int pipefds[2];
static int expected_seqnum = 0;
volatile static int children_waiting;
-volatile static int msg_q_timeout;
+volatile static int run_msg_q;
+volatile static int sig_flag;
+static int run_exec_q;
-LIST_HEAD(msg_list);
-LIST_HEAD(exec_list);
-LIST_HEAD(running_list);
+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_kids(void);
-unsigned char logname[42];
-
-int log_ok(void)
+#ifdef LOG
+unsigned char logname[LOGNAME_SIZE];
+void log_message (int level, const char *format, ...)
{
- return 1;
+ va_list args;
+
+ va_start(args, format);
+ vsyslog(level, format, args);
+ va_end(args);
}
+#endif
static void msg_dump_queue(void)
{
+#ifdef DEBUG
struct hotplug_msg *msg;
list_for_each_entry(msg, &msg_list, list)
dbg("sequence %d in queue", msg->seqnum);
+#endif
}
static void msg_dump(struct hotplug_msg *msg)
{
list_del(&msg->list);
free(msg);
- exec_queue_manager();
}
/* orders the message in the queue by sequence number */
{
struct hotplug_msg *loop_msg;
- /* sort message by sequence number into list*/
- list_for_each_entry(loop_msg, &msg_list, list)
- if (loop_msg->seqnum > msg->seqnum)
+ /* 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 (loop_msg->seqnum < msg->seqnum)
break;
- list_add_tail(&msg->list, &loop_msg->list);
+ list_add(&msg->list, &loop_msg->list);
dbg("queued message seq %d", msg->seqnum);
/* store timestamp of queuing */
msg->queue_time = time(NULL);
/* run msg queue manager */
- msg_queue_manager();
+ run_msg_q = 1;
return ;
}
static void udev_run(struct hotplug_msg *msg)
{
pid_t pid;
- setenv("ACTION", msg->action, 1);
- setenv("DEVPATH", msg->devpath, 1);
+ char action[ACTION_SIZE];
+ char devpath[DEVPATH_SIZE];
+ char *env[] = { action, devpath, NULL };
+
+ snprintf(action, sizeof(action), "ACTION=%s", msg->action);
+ snprintf(devpath, sizeof(devpath), "DEVPATH=%s", msg->devpath);
pid = fork();
switch (pid) {
case 0:
/* child */
- execl(UDEV_BIN, "udev", msg->subsystem, NULL);
+ execle(UDEV_BIN, "udev", msg->subsystem, NULL, env);
dbg("exec of child failed");
exit(1);
break;
case -1:
dbg("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 */
static void msg_move_exec(struct hotplug_msg *msg)
{
list_move_tail(&msg->list, &exec_list);
- exec_queue_manager();
+ run_exec_q = 1;
expected_seqnum = msg->seqnum+1;
dbg("moved seq %d to exec, next expected is %d",
msg->seqnum, expected_seqnum);
{
struct hotplug_msg *msg;
int retval;
+ struct msghdr smsg;
+ struct cmsghdr *cmsg;
+ struct iovec iov;
+ struct ucred *cred;
+ char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
msg = msg_create();
if (msg == NULL) {
return;
}
- retval = recv(sock, msg, sizeof(struct hotplug_msg), 0);
+ iov.iov_base = msg;
+ iov.iov_len = sizeof(struct hotplug_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);
+
+ retval = recvmsg(sock, &smsg, 0);
if (retval < 0) {
if (errno != EINTR)
dbg("unable to receive message");
return;
}
-
+ 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 skip;
+ }
+
+ if (cred->uid != 0) {
+ dbg("sender uid=%i, message ignored", cred->uid);
+ goto skip;
+ }
+
if (strncmp(msg->magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) {
dbg("message magic '%s' doesn't match, ignore it", msg->magic);
- free(msg);
- return;
+ goto skip;
}
/* if no seqnum is given, we move straight to exec queue */
if (msg->seqnum == -1) {
list_add(&msg->list, &exec_list);
- exec_queue_manager();
+ run_exec_q = 1;
} else {
msg_queue_insert(msg);
}
+ return;
+
+skip:
+ free(msg);
+ return;
}
static void sig_handler(int signum)
{
+ int rc;
switch (signum) {
case SIGINT:
case SIGTERM:
exit(20 + signum);
break;
case SIGALRM:
- msg_q_timeout = 1;
+ /* 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 */
children_waiting = 1;
+ goto do_write;
break;
default:
dbg("unhandled signal");
+ return;
+ }
+
+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)
+ dbg("unable to write to pipe");
+ else
+ sig_flag = 1;
}
}
if (msg->pid == pid) {
dbg("<== exec seq %d 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_kids()
+{
+ /* reap all dead children */
+ while(1) {
+ int pid = waitpid(-1, 0, WNOHANG);
+ if ((pid == -1) || (pid == 0))
+ break;
+ udev_done(pid);
+ }
+}
+
+/* just read everything from the pipe and clear the flag,
+ * the useful flags were set in the signal handler
+ */
+static void user_sighandler()
+{
+ int sig;
+ while(1) {
+ int rc = read(pipefds[0],&sig,sizeof(sig));
+ if (rc < 0)
+ break;
+
+ sig_flag = 0;
+ }
+}
+
+
int main(int argc, char *argv[])
{
- int ssock;
+ int ssock, maxsockplus;
struct sockaddr_un saddr;
socklen_t addrlen;
int retval;
+ const int on = 1;
+ struct sigaction act;
+ fd_set readfds;
init_logging("udevd");
+ dbg("version %s", UDEV_VERSION);
- signal(SIGINT, sig_handler);
- signal(SIGTERM, sig_handler);
- signal(SIGALRM, sig_handler);
- signal(SIGCHLD, sig_handler);
-
- /* we want these two to interrupt system calls */
- siginterrupt(SIGALRM, 1);
- siginterrupt(SIGCHLD, 1);
+ if (getuid() != 0) {
+ dbg("need to be root, exit");
+ exit(1);
+ }
+
+ /* setup signal handler pipe */
+ retval = pipe(pipefds);
+ if (retval < 0) {
+ dbg("error getting pipes: %s", strerror(errno));
+ exit(1);
+ }
+
+ retval = fcntl(pipefds[0], F_SETFL, O_NONBLOCK);
+ if (retval < 0) {
+ dbg("fcntl on read pipe: %s", strerror(errno));
+ exit(1);
+ }
+
+ retval = fcntl(pipefds[1], F_SETFL, O_NONBLOCK);
+ if (retval < 0) {
+ dbg("fcntl on write pipe: %s", strerror(errno));
+ exit(1);
+ }
+
+ /* set signal handlers */
+ act.sa_handler = 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);
memset(&saddr, 0x00, sizeof(saddr));
saddr.sun_family = AF_LOCAL;
ssock = socket(AF_LOCAL, SOCK_DGRAM, 0);
if (ssock == -1) {
- dbg("error getting socket");
+ dbg("error getting socket, exit");
exit(1);
}
/* the bind takes care of ensuring only one copy running */
- retval = bind(ssock, &saddr, addrlen);
+ retval = bind(ssock, (struct sockaddr *) &saddr, addrlen);
if (retval < 0) {
- dbg("bind failed\n");
+ dbg("bind failed, exit");
goto exit;
}
- while (1) {
- handle_msg(ssock);
+ /* enable receiving of the sender credentials */
+ setsockopt(ssock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
- while(msg_q_timeout) {
- msg_q_timeout = 0;
- msg_queue_manager();
+ FD_ZERO(&readfds);
+ FD_SET(ssock, &readfds);
+ FD_SET(pipefds[0], &readfds);
+ maxsockplus = ssock+1;
+ while (1) {
+ fd_set workreadfds = readfds;
+ retval = select(maxsockplus, &workreadfds, NULL, NULL, NULL);
+
+ if (retval < 0) {
+ dbg("error in select: %s", strerror(errno));
+ continue;
}
-
- while(children_waiting) {
+
+ if (FD_ISSET(ssock, &workreadfds))
+ handle_msg(ssock);
+
+ if (FD_ISSET(pipefds[0], &workreadfds))
+ user_sighandler();
+
+ if (children_waiting) {
children_waiting = 0;
- /* reap all dead children */
- while(1) {
- int pid = waitpid(-1, 0, WNOHANG);
- if ((pid == -1) || (pid == 0))
- break;
- udev_done(pid);
+ reap_kids();
+ }
+
+ if (run_msg_q) {
+ run_msg_q = 0;
+ msg_queue_manager();
+ }
+
+ if (run_exec_q) {
+
+ /* this is tricky. exec_queue_manager() loops over exec_list, and
+ * calls running_with_devpath(), which loops over running_list. This gives
+ * O(N*M), which can get *nasty*. Clean up running_list before
+ * calling exec_queue_manager().
+ */
+
+ if (children_waiting) {
+ children_waiting = 0;
+ reap_kids();
}
+
+ run_exec_q = 0;
+ exec_queue_manager();
}
}
exit:
~ianmdlvl / elogind.git / blobdiff