syscalls: mknodat

kernel-src/arch/x86-64/syscall.asm

@@ -77,6 +77,7 @@ extern syscall_pause
 extern syscall_ppoll
 extern syscall_pread
 extern syscall_pwrite
+extern syscall_mknodat
 syscalltab:
 dq syscall_print
 dq syscall_mmap
@@ -156,7 +157,8 @@ dq syscall_pause
 dq syscall_ppoll
 dq syscall_pread
 dq syscall_pwrite
-syscallcount equ 78
+dq syscall_mknodat
+syscallcount equ 79
 section .text
 global arch_syscall_entry
 ; on entry:

kernel-src/arch/x86-64/syscalllog.c

@@ -5,7 +5,7 @@
 
 #ifdef SYSCALL_LOGGING
 
-#define SYSCALL_COUNT 78
+#define SYSCALL_COUNT 79
 #define LOGSTR(x) arch_e9_puts(x)
 
 static char *name[] = {
@@ -86,7 +86,8 @@ static char *name[] = {
 	"pause",
 	"ppoll",
 	"pread",
-	"pwrite"
+	"pwrite",
+	"mknodat"
 };
 
 static char *args[] = {
@@ -165,9 +166,10 @@ static char *args[] = {
 	"fd %d addr %p addrlen %p",  // getpeername
 	"path %s", // chroot
 	"N/A", // pause
-	"fds %p nfds %d timeout %p sigmask %p" // ppoll
+	"fds %p nfds %d timeout %p sigmask %p", // ppoll
 	"fd %d buffer %p count %lu offset %lu\n", // pread
 	"fd %d buffer %p count %lu offset %lu\n", // pwrite
+	"dirfd %d path %s mode %o dev %x\n" // mknodat
 };
 
 #endif

kernel-src/include/kernel/vfs.h

@@ -224,4 +224,25 @@ static inline mode_t vfs_getposixtype(int type) {
 	}
 }
 
+static inline mode_t vfs_getsystemtype(int type) {
+	switch (type) {
+		case TYPE_REGULAR:
+			return V_TYPE_REGULAR;
+		case TYPE_DIR:
+			return V_TYPE_DIR;
+		case TYPE_CHARDEV:
+			return V_TYPE_CHDEV;
+		case TYPE_BLOCKDEV:
+			return V_TYPE_BLKDEV;
+		case TYPE_FIFO:
+			return V_TYPE_FIFO;
+		case TYPE_LINK:
+			return V_TYPE_LINK;
+		case TYPE_SOCKET:
+			return V_TYPE_SOCKET;
+		default:
+			return -1;
+	}
+}
+
 #endif

kernel-src/sys/syscalls/mknodat.c

@@ -0,0 +1,58 @@
+#include <kernel/syscalls.h>
+#include <kernel/file.h>
+#include <kernel/vfs.h>
+#include <kernel/alloc.h>
+#include <kernel/abi.h>
+#include <arch/cpu.h>
+
+syscallret_t syscall_mknodat(context_t *, int dirfd, char *upath, mode_t mode, dev_t dev) {
+	syscallret_t ret = {
+		.ret = -1
+	};
+
+	size_t pathlen;
+	ret.errno = usercopy_strlen(upath, &pathlen);
+	if (ret.errno)
+		return ret;
+
+	char *path = alloc(pathlen + 1);
+	if (path == NULL) {
+		ret.errno = ENOMEM;
+		return ret;
+	}
+
+	ret.errno = usercopy_fromuser(path, upath, pathlen);
+	if (ret.errno) {
+		free(path);
+		return ret;
+	}
+
+	vnode_t *dirnode = NULL;
+	file_t *file = NULL;
+	ret.errno = dirfd_enter(path, dirfd, &file, &dirnode);
+	if (ret.errno)
+		goto cleanup;
+
+	int type = vfs_getsystemtype(GETTYPE(mode));
+	mode = GETMODE(mode);
+
+	vattr_t attr = {
+		.mode = UMASK(mode),
+		.gid = _cpu()->thread->proc->cred.gid,
+		.uid = _cpu()->thread->proc->cred.uid,
+		.rdevmajor = (type == V_TYPE_CHDEV || type == V_TYPE_BLKDEV) ? MAJORDEV(dev) : 0,
+		.rdevminor = (type == V_TYPE_CHDEV || type == V_TYPE_BLKDEV) ? MINORDEV(dev) : 0,
+	};
+
+	ret.errno = vfs_create(dirnode, path, &attr, type, NULL);
+	ret.ret = ret.errno ? -1 : 0;
+
+	cleanup:
+
+	if (dirnode)
+		dirfd_leave(dirnode, file);
+
+	free(path);
+
+	return ret;
+}