#include <string.h>
#include <errno.h>
#include <linux/msg.h>
+#include <fcntl.h>
#define MAX_MSG_SIZE 32
#define ANOTHER_MSG_TYPE 26538
struct msgque_data {
+ key_t key;
int msq_id;
int qbytes;
- int kern_id;
int qnum;
int mode;
struct msg1 *messages;
int restore_queue(struct msgque_data *msgque)
{
- struct msqid_ds ds;
- int id, i;
+ int fd, ret, id, i;
+ char buf[32];
- id = msgget(msgque->msq_id,
- msgque->mode | IPC_CREAT | IPC_EXCL | IPC_PRESET);
- if (id == -1) {
- printf("Failed to create queue\n");
+ fd = open("/proc/sys/kernel/msg_next_id", O_WRONLY);
+ if (fd == -1) {
+ printf("Failed to open /proc/sys/kernel/msg_next_id\n");
return -errno;
}
+ sprintf(buf, "%d", msgque->msq_id);
- if (id != msgque->msq_id) {
- printf("Failed to preset id (%d instead of %d)\n",
- id, msgque->msq_id);
- return -EFAULT;
+ ret = write(fd, buf, strlen(buf));
+ if (ret != strlen(buf)) {
+ printf("Failed to write to /proc/sys/kernel/msg_next_id\n");
+ return -errno;
}
- if (msgctl(id, MSG_STAT, &ds) < 0) {
- printf("Failed to stat queue\n");
+ id = msgget(msgque->key, msgque->mode | IPC_CREAT | IPC_EXCL);
+ if (id == -1) {
+ printf("Failed to create queue\n");
return -errno;
}
- ds.msg_perm.key = msgque->msq_id;
- ds.msg_qbytes = msgque->qbytes;
- if (msgctl(id, MSG_SET, &ds) < 0) {
- printf("Failed to update message key\n");
- return -errno;
+ if (id != msgque->msq_id) {
+ printf("Restored queue has wrong id (%d instead of %d)\n",
+ id, msgque->msq_id);
+ ret = -EFAULT;
+ goto destroy;
}
for (i = 0; i < msgque->qnum; i++) {
- if (msgsnd(msgque->msq_id, &msgque->messages[i].mtype, msgque->messages[i].msize, IPC_NOWAIT) != 0) {
+ if (msgsnd(msgque->msq_id, &msgque->messages[i].mtype,
+ msgque->messages[i].msize, IPC_NOWAIT) != 0) {
printf("msgsnd failed (%m)\n");
- return -errno;
+ ret = -errno;
+ goto destroy;
};
}
return 0;
+
+destroy:
+ if (msgctl(id, IPC_RMID, 0))
+ printf("Failed to destroy queue: %d\n", -errno);
+ return ret;
}
int check_and_destroy_queue(struct msgque_data *msgque)
int cnt = 0, ret;
while (1) {
- ret = msgrcv(msgque->msq_id, &message.mtype, MAX_MSG_SIZE, 0, IPC_NOWAIT);
+ ret = msgrcv(msgque->msq_id, &message.mtype, MAX_MSG_SIZE,
+ 0, IPC_NOWAIT);
if (ret < 0) {
if (errno == ENOMSG)
break;
goto err;
}
if (ret != msgque->messages[cnt].msize) {
- printf("Wrong message size: %d (expected %d)\n", ret, msgque->messages[cnt].msize);
+ printf("Wrong message size: %d (expected %d)\n", ret,
+ msgque->messages[cnt].msize);
ret = -EINVAL;
goto err;
}
int dump_queue(struct msgque_data *msgque)
{
- struct msqid_ds ds;
+ struct msqid64_ds ds;
+ int kern_id;
int i, ret;
- for (msgque->kern_id = 0; msgque->kern_id < 256; msgque->kern_id++) {
- ret = msgctl(msgque->kern_id, MSG_STAT, &ds);
+ for (kern_id = 0; kern_id < 256; kern_id++) {
+ ret = msgctl(kern_id, MSG_STAT, &ds);
if (ret < 0) {
if (errno == -EINVAL)
continue;
- printf("Failed to get stats for IPC queue with id %d\n", msgque->kern_id);
+ printf("Failed to get stats for IPC queue with id %d\n",
+ kern_id);
return -errno;
}
msgque->qbytes = ds.msg_qbytes;
for (i = 0; i < msgque->qnum; i++) {
- ret = msgrcv(msgque->msq_id, &msgque->messages[i].mtype, MAX_MSG_SIZE, i, IPC_NOWAIT | MSG_COPY);
+ ret = msgrcv(msgque->msq_id, &msgque->messages[i].mtype,
+ MAX_MSG_SIZE, i, IPC_NOWAIT | MSG_COPY);
if (ret < 0) {
printf("Failed to copy IPC message: %m (%d)\n", errno);
return -errno;
msgbuf.mtype = MSG_TYPE;
memcpy(msgbuf.mtext, TEST_STRING, sizeof(TEST_STRING));
- if (msgsnd(msgque->msq_id, &msgbuf.mtype, sizeof(TEST_STRING), IPC_NOWAIT) != 0) {
+ if (msgsnd(msgque->msq_id, &msgbuf.mtype, sizeof(TEST_STRING),
+ IPC_NOWAIT) != 0) {
printf("First message send failed (%m)\n");
return -errno;
};
msgbuf.mtype = ANOTHER_MSG_TYPE;
memcpy(msgbuf.mtext, ANOTHER_TEST_STRING, sizeof(ANOTHER_TEST_STRING));
- if (msgsnd(msgque->msq_id, &msgbuf.mtype, sizeof(ANOTHER_TEST_STRING), IPC_NOWAIT) != 0) {
+ if (msgsnd(msgque->msq_id, &msgbuf.mtype, sizeof(ANOTHER_TEST_STRING),
+ IPC_NOWAIT) != 0) {
printf("Second message send failed (%m)\n");
return -errno;
};
return 0;
}
-int main (int argc, char **argv)
+int main(int argc, char **argv)
{
- key_t key;
int msg, pid, err;
struct msgque_data msgque;
- key = ftok(argv[0], 822155650);
- if (key == -1) {
+ msgque.key = ftok(argv[0], 822155650);
+ if (msgque.key == -1) {
printf("Can't make key\n");
return -errno;
}
- msgque.msq_id = msgget(key, IPC_CREAT | IPC_EXCL | 0666);
+ msgque.msq_id = msgget(msgque.key, IPC_CREAT | IPC_EXCL | 0666);
if (msgque.msq_id == -1) {
printf("Can't create queue\n");
goto err_out;