First version that can mount some actual fs

3 files changed, 203 insertions, 38 deletions

diff --git a/Makefile b/Makefile
index 217284f..5f8c38a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,2 +1,3 @@
 make:
-	gcc nmount.c -o nmount
\ No newline at end of file
+	gcc -Wall nmount.c -o nmount
+	gcc -static nmount.c -o nmount_static
\ No newline at end of file
diff --git a/README.txt b/README.txt
new file mode 100644
index 0000000..e5ed452
--- /dev/null
+++ b/README.txt
@@ -0,0 +1,4 @@
+
+nmount -t proc -d /proc2 -f nosuid,nodev,noexec 
+nmount -v -t proc -d /Process -f nosuid,nodev,noexec 
+nmount -v -t ext4 -s /dev/mmcblk0p7 -d /mnt/disk0 -f nodev,noexec,nosuid
\ No newline at end of file
diff --git a/nmount.c b/nmount.c
index 8e51ec3..8142531 100644
--- a/nmount.c
+++ b/nmount.c
@@ -6,39 +6,47 @@
 #include <fcntl.h>
 #include <getopt.h>
 #include <signal.h>
+#include <string.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <errno.h>
+
 
 /////////////////////////////////////////////////////////////////////////////////////////
 /*FLAGS FROM KERNEL*/
 
-//#define MS_RDONLY	 1	/* Mount read-only */
-//#define MS_NOSUID	 2	/* Ignore suid and sgid bits */
-//#define MS_NODEV	 4	/* Disallow access to device special files */
-//#define MS_NOEXEC	 8	/* Disallow program execution */
-//#define MS_SYNCHRONOUS	16	/* Writes are synced at once */
-//#define MS_REMOUNT	32	/* Alter flags of a mounted FS */
-//#define MS_MANDLOCK	64	/* Allow mandatory locks on an FS */
-//#define MS_DIRSYNC	128	/* Directory modifications are synchronous */
-//#define MS_NOATIME	1024	/* Do not update access times. */
-//#define MS_NODIRATIME	2048	/* Do not update directory access times */
-//#define MS_BIND		4096
-//#define MS_MOVE		8192
-//#define MS_REC		16384
-//#define MS_VERBOSE	32768	/* War is peace. Verbosity is silence.
-//				   MS_VERBOSE is deprecated. */
-//#define MS_SILENT	32768
-//#define MS_POSIXACL	(1<<16)	/* VFS does not apply the umask */
-//#define MS_UNBINDABLE	(1<<17)	/* change to unbindable */
-//#define MS_PRIVATE	(1<<18)	/* change to private */
-//#define MS_SLAVE	(1<<19)	/* change to slave */
-//#define MS_SHARED	(1<<20)	/* change to shared */
-//#define MS_RELATIME	(1<<21)	/* Update atime relative to mtime/ctime. */
-//#define MS_KERNMOUNT	(1<<22) /* this is a kern_mount call */
-//#define MS_I_VERSION	(1<<23) /* Update inode I_version field */
-//#define MS_STRICTATIME	(1<<24) /* Always perform atime updates */
-//#define MS_LAZYTIME	(1<<25) /* Update the on-disk [acm]times lazily */
+#define _MS_RDONLY       (1<<0)
+#define _MS_NOSUID       (1<<1)
+#define _MS_NODEV        (1<<2)
+#define _MS_NOEXEC       (1<<3)
+#define _MS_SYNCHRONOUS  (1<<4)
+#define _MS_REMOUNT      (1<<5)
+#define _MS_MANDLOCK     (1<<6)
+#define _MS_DIRSYNC      (1<<7)
+#define _MS_NOATIME      (1<<10)
+#define _MS_NODIRATIME   (1<<11)
+#define _MS_BIND         (1<<12)
+#define _MS_MOVE         (1<<13)
+#define _MS_REC          (1<<14)
+#define _MS_SILENT       (1<<15)
+#define _MS_POSIXACL     (1<<16)
+#define _MS_UNBINDABLE   (1<<17)
+#define _MS_PRIVATE      (1<<18)
+#define _MS_SLAVE        (1<<19)
+#define _MS_SHARED       (1<<20)
+#define _MS_RELATIME     (1<<21)
+#define _MS_KERNMOUNT    (1<<22)
+#define _MS_I_VERSION    (1<<23)
+#define _MS_STRICTATIME  (1<<24)
+#define _MS_LAZYTIME     (1<<25)
 
 #define STRUCT_LEN(VAR,STRUCT) ((sizeof(VAR)/sizeof(STRUCT))-1)
 
+#define max(a,b) \
+   ({ __typeof__ (a) _a = (a); \
+       __typeof__ (b) _b = (b); \
+     _a > _b ? _a : _b; })
+
 typedef struct vfs_option_params {
     char *val;
     char *descr;
@@ -60,16 +68,17 @@ typedef struct vfs_options
 {
     char *options;
     char *description;
-    vfs_option_params **params;
+    vfs_option_params *params;
 } vfs_options;
 
 vfs_options vfs_options_proc[] =
 {
-    {"hidepid=\%u" ,"",                                     &vfs_options_proc_params_hidepid},
-    {"gid=\%u"     ,"user group that can access process",   &vfs_options_proc_params_gid},
+    {"hidepid=\%u" ,"",                                     (struct vfs_option_params *)&vfs_options_proc_params_hidepid},
+    {"gid=\%u"     ,"user group that can access process",   (struct vfs_option_params *)&vfs_options_proc_params_gid},
     {NULL,NULL,NULL}
 };
 
+
 static const struct vfs {
     char *name;
     long flags;
@@ -78,7 +87,7 @@ static const struct vfs {
 } vfstab[] = {
     {"devtmpfs",  0, "/Device",  NULL},
     {"mqueue",    0, "/MQueue/", NULL},
-    {"proc",      0, "/Process", &vfs_options_proc},
+    {"proc",      0, "/Process", (struct vfs_options*)&vfs_options_proc},
     {"tmpfs",     0, "/Ram",     NULL},
     {"sysfs",     0, "/System",  NULL},
     {"ext4",      0, NULL,       NULL},
@@ -86,11 +95,31 @@ static const struct vfs {
     {NULL,        0, NULL,       NULL},
 };
 
+static const struct mount_flags
+{
+    char *name;
+    unsigned long bitfield;
+} mountflgs[] = {
+    {"bind",_MS_BIND},
+    {"move",_MS_MOVE},
+    {"rdonly",_MS_RDONLY},
+    {"lazytime",_MS_LAZYTIME},
+    {"nodev",_MS_NODEV},
+    {"noexec",_MS_NOEXEC},
+    {"nosuid",_MS_NOSUID},
+    {"remount",_MS_REMOUNT},
+    {"silent",_MS_SILENT},
+    {"sync",_MS_SYNCHRONOUS},
+    {NULL,0},
+};
+
 typedef struct {
-    char *f_device;
+    char *f_source_dir;
+    char *f_target_dir;
     char *f_type;
     char *f_dir;
     char *f_flags;//g_params.f_output = 1;
+    unsigned long mount_flags;
     char *f_options;
     int   f_verbose;
     int   f_helper;
@@ -102,9 +131,9 @@ void helper(char *progname)
 {
     printf("Usage: %s [OPTS]\n\n"
         "Version: 0.0.1 \n"
-        "-d device to mount\n"
+        "-s source directory\n"
+        "-d target directory\n"
         "-t filesystem type\n"
-        "-d mount directory\n"
         "-f mount flags\n"
         "-o mount fs options\n"
         "-v verbose output\n"
@@ -130,6 +159,33 @@ void sig_handler(int signo)
     exit(0);
 }
 
+int check_filetype(char *fsname)
+{
+    int i;
+    for (i=0;i<STRUCT_LEN(vfstab,struct vfs);i++)
+    {
+         if (strncmp(vfstab[i].name,fsname,max(strlen(vfstab[i].name),strlen(fsname))) == 0)
+         {
+            return 1;
+         }
+    }
+
+    return 0;
+}
+
+unsigned long str2flag(char *opt)
+{
+    int i;
+    for (i=0;i<STRUCT_LEN(mountflgs, struct mount_flags);i++)
+    {
+        if (strncmp(mountflgs[i].name,opt,strlen(mountflgs[i].name)) == 0)
+        {
+            return mountflgs[i].bitfield;
+        }
+    }
+    return 0;
+}
+
 int smount(
     const char *source, 
     const char *target,
@@ -137,14 +193,26 @@ int smount(
     unsigned long mountflags,
     const void *data)
 {
+    int ret=-1;
 
-    return 0;
+    if (g_params.f_verbose)
+    {
+        printf("Syscal params:\n");
+        printf("source     :%s\n",source);
+        printf("target     :%s\n",target);
+        printf("filesystem :%s\n",filesystemtype);
+        printf("mountflags :%lu\n",mountflags);
+        printf("data       :%016xxd\n",data);
+    }
+    ret = syscall(SYS_mount,source,target,filesystemtype,mountflags,data);
+
+    return ret;
 }
 
 int main(int argc, char **argv)
 {
     int c;
-    int i;
+    int i,j,k;
 
     printf("One big real mount\n");
 
@@ -153,9 +221,11 @@ int main(int argc, char **argv)
         printf("cannot register signal handler\n");
         exit(1);
     }
+
+    memset(&g_params,0,sizeof(g_params));
     
     //process arguments
-    while ((c = getopt(argc, argv, "a")) != -1)
+    while ((c = getopt(argc, argv, "ad:t:f:o:vs:")) != -1)
     {
         switch (c)
         {
@@ -163,7 +233,24 @@ int main(int argc, char **argv)
                 //g_params.f_output = 1;
                 g_params.f_helper = 1;
                 break;
-            
+            case 's':
+                g_params.f_source_dir = optarg;
+                break;
+            case 'd':
+                g_params.f_target_dir = optarg;
+                break;
+            case 't':
+                g_params.f_type = optarg;
+                break;
+            case 'f':
+                g_params.f_flags = optarg;
+                break;
+            case 'o':
+                g_params.f_options = optarg;
+                break;
+            case 'v':
+                g_params.f_verbose = 1;
+                break;
             default:
                 helper(argv[0]);
                 exit(1);
@@ -175,9 +262,82 @@ int main(int argc, char **argv)
         for (i=0;i<STRUCT_LEN(vfstab,struct vfs);i++)
         {
             printf("%s %s\n",vfstab[i].name,vfstab[i].mountpoint);
+            if (vfstab[i].options != NULL)
+            {
+                j = 0;
+                while (vfstab[i].options[j].options != NULL)
+                {
+                    printf("\t%s %s\n",
+                        vfstab[i].options[j].options,
+                        vfstab[i].options[j].description
+                    );
+                    k = 0;
+                    while(vfstab[i].options[j].params[k].val != NULL)
+                    {
+                        printf("\t\t%s %s\n",
+                            vfstab[i].options[j].params[k].val,
+                            vfstab[i].options[j].params[k].descr
+                        );
+                        k++;
+                    }
+                    j++;
+                }
+            }
+        }
+    }
+
+    if (NULL != g_params.f_type)
+    {
+        if (check_filetype(g_params.f_type) != 1)
+        {
+            printf("Unknow file type %s\n",g_params.f_type);
+            printf("Supported formats: ");
+            for (i=0;i<STRUCT_LEN(vfstab,struct vfs);i++)
+            {
+                printf("%s ",vfstab[i].name);
+            }
+            printf("\n");
+            return 1;
         }
     }
 
+    if (NULL != g_params.f_flags)
+    {
+        char *token = strtok(g_params.f_flags,",");
+        printf("Flags: %d\n",g_params.mount_flags);
+        while ( token != NULL )
+        {
+            printf("Flags: %s\n",token);
+            g_params.mount_flags |= str2flag(token);
+            printf("Flags: %d\n",g_params.mount_flags);
+            token = strtok(NULL,",");
+        }
+    }
+
+    if (NULL != g_params.f_target_dir)
+    {
+        mkdir(g_params.f_target_dir, 0000);
+    }
+
+    if ((NULL != g_params.f_target_dir) && 
+        (NULL != g_params.f_flags) &&
+        (NULL != g_params.f_type) &&
+        (NULL != g_params.f_source_dir))
+    {
+        printf("Flags: %d\n",g_params.mount_flags);
+        int ret = smount(
+            g_params.f_source_dir,
+            g_params.f_target_dir,
+            g_params.f_type, 
+            g_params.mount_flags, 
+            "");
+        int err = errno;
+        printf("Mount exit code %d\n",ret);
+        if (ret==-1)
+        {
+            printf("Strerr: %d %s\n",err,strerror(err));
+        }
+    }
 
     return 0;
 }