mount and umount commands

Makefile

@@ -12,7 +12,9 @@ STAGE_BIN=$(STAGE)/init \
 		  $(STAGE)/bin/ls \
 		  $(STAGE)/bin/reboot \
 		  $(STAGE)/bin/date \
-		  $(STAGE)/bin/uname
+		  $(STAGE)/bin/uname \
+		  $(STAGE)/bin/mount \
+		  $(STAGE)/bin/umount
 
 usr_CFLAGS=-msse \
 	   	   -msse2 \

core/bin/mount.c

@@ -0,0 +1,90 @@
+#include <stdio.h>
+
+static void usage(void) {
+    printf("Usage: mount [-t type] device target\n");
+}
+
+int main(int argc, char **argv) {
+    int res;
+    struct stat st;
+    const char *type = NULL;
+    const char *src = NULL;
+    const char *dst = NULL;
+    uid_t uid;
+
+    // Crude attempt at getopt()
+    for (int i = 1; i < argc; ++i) {
+        if (argv[i][0] == '-') {
+            switch (argv[i][1]) {
+            case 't':
+                if (i == argc - 1) {
+                    usage();
+                    return -1;
+                }
+                type = argv[i + 1];
+                ++i;
+                break;
+            default:
+                return -1;
+            }
+
+            continue;
+        }
+
+        if (!src) {
+            src = argv[i];
+        } else if (!dst) {
+            dst = argv[i];
+        } else {
+            usage();
+            return -1;
+        }
+    }
+
+    if (!dst) {
+        dst = src;
+        src = NULL;
+    }
+    if (!dst) {
+        usage();
+        return -1;
+    }
+
+    // Check that UID is 0
+    if ((uid = getuid()) != 0) {
+        printf("mount should be run as root\n");
+        return -1;
+    }
+
+    if (src) {
+        // Check that "src" is a block device
+        if ((res = stat(src, &st)) != 0) {
+            perror(src);
+            return -1;
+        }
+
+        if ((st.st_mode & S_IFMT) != S_IFBLK) {
+            printf("%s: Not a block device\n", src);
+            return -1;
+        }
+    }
+
+    // Check that "dst" is a directory
+    if ((res = stat(dst, &st)) != 0) {
+        perror(dst);
+        return -1;
+    }
+
+    if ((st.st_mode & S_IFMT) != S_IFDIR) {
+        printf("%s: Not a directory\n", dst);
+        return -1;
+    }
+
+    // Do the magic stuff
+    if ((res = mount(src, dst, type, 0, NULL)) != 0) {
+        perror("mount()");
+        return -1;
+    }
+
+    return 0;
+}

core/bin/umount.c

@@ -0,0 +1,17 @@
+#include <stdio.h>
+
+int main(int argc, char **argv) {
+    int res;
+
+    if (argc != 2) {
+        printf("Usage: umount dir\n");
+        return -1;
+    }
+
+    if ((res = umount(argv[1])) != 0) {
+        perror(argv[1]);
+        return -1;
+    }
+
+    return 0;
+}

init.c

@@ -550,7 +550,11 @@ static int b_dir(const char *arg) {
 }
 
 static int b_abort(const char *arg) {
+    printf("Before SIGUSR1\n");
+    raise(SIGUSR1);
+    printf("After SIGUSR1\n");
     abort();
+    printf("This code should not run\n");
     return 0;
 }
 
@@ -832,32 +836,23 @@ static int cmd_exec(const char *line) {
     return -1;
 }
 
+static void sigusr1_handler(int signum) {
+    printf("SIGUSR1 received and handled\n");
+}
+
 int main(int argc, char **argv) {
     if (getpid() != 1) {
         printf("Won't work if PID is not 1\n");
         return -1;
     }
 
+    signal(SIGUSR1, sigusr1_handler);
+
     char linebuf[512];
     char c;
     size_t l = 0;
     int res;
 
-    // Try to mount devfs
-    const char *automount_dev = "/dev/sda1";
-
-    if ((res = mount(NULL, "/dev", "devfs", 0, NULL)) != 0) {
-        perror("Failed to mount devfs");
-    }
-    // Mount sda1 if present
-    if (access(automount_dev, F_OK) == 0) {
-        printf("%s exists, trying to mount at /mnt\n", automount_dev);
-
-        if ((res = mount(automount_dev, "/mnt", "ext2", 0, NULL)) != 0) {
-            perror(automount_dev);
-        }
-    }
-
     //setuid(1000);
     //setgid(1000);