Fix permission management for IPC and also for EXT2.

2023-05-23 13:40:02 -04:00
parent e7c0334ac0
commit 3ae9258347
12 changed files with 394 additions and 400 deletions
@@ -0,0 +1,88 @@
+/// @file t_semop.c
+/// @brief Tests semop between processes.
+/// @copyright (c) 2014-2023 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
+
+#include "sys/sem.h"
+#include "stdio.h"
+#include "sys/ipc.h"
+#include "sys/errno.h"
+#include "sys/wait.h"
+#include "stdlib.h"
+#include "sys/unistd.h"
+#include "fcntl.h"
+
+int main(int argc, char *argv[])
+{
+    struct sembuf sops[6];
+    sops[0].sem_num = 0;
+    sops[0].sem_op  = -1;
+    sops[0].sem_flg = 0;
+
+    sops[1].sem_num = 1;
+    sops[1].sem_op  = -1;
+    sops[1].sem_flg = 0;
+
+    sops[2].sem_num = 2;
+    sops[2].sem_op  = -1;
+    sops[2].sem_flg = 0;
+
+    sops[3].sem_num = 0;
+    sops[3].sem_op  = 1;
+    sops[3].sem_flg = 0;
+
+    sops[4].sem_num = 1;
+    sops[4].sem_op  = 1;
+    sops[4].sem_flg = 0;
+
+    sops[5].sem_num = 2;
+    sops[5].sem_op  = 1;
+    sops[5].sem_flg = 0;
+
+    int status;
+
+    //create a semaphore set
+    int semid = semget(17, 4, IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+
+    //set the values of the semaphores
+    unsigned short values[] = { 0, 0, 0, 1 };
+
+    union semun arg;
+    arg.array = values;
+
+    if (semctl(semid, 0, SETALL, &arg) == -1) {
+        perror("Failed to set semaphores");
+        return 1;
+    }
+
+    if (!fork()) {
+        semop(semid, &sops[0], 1);
+        printf("cheers!\n");
+        exit(0);
+    }
+    if (!fork()) {
+        semop(semid, &sops[1], 1);
+        printf("course, ");
+        semop(semid, &sops[3], 1);
+        exit(0);
+    }
+    if (!fork()) {
+        semop(semid, &sops[2], 1);
+        printf("systems ");
+        semop(semid, &sops[4], 1);
+        exit(0);
+    }
+    if (!fork()) {
+        printf("From the operating ");
+        semop(semid, &sops[5], 1);
+        exit(0);
+    }
+    for (int n = 0; n < 4; n++) {
+        wait(&status);
+    }
+    if (semctl(semid, 0, IPC_RMID, 0) == -1) {
+        perror("Failed to remove IPC");
+        return 1;
+    }
+    return 0;
+}