From 9ebf29991d24f27eab9f334f273808017b90a80e Mon Sep 17 00:00:00 2001
From: Bananymous <bananymousosq@gmail.com>
Date: Sun, 10 Sep 2023 00:01:50 +0300
Subject: [PATCH] Kernel: Add basic dd command

This only supports if, of, bs, count and status=progress
---
 userspace/CMakeLists.txt    |   1 +
 userspace/dd/CMakeLists.txt |  17 +++++
 userspace/dd/main.cpp       | 137 ++++++++++++++++++++++++++++++++++++
 3 files changed, 155 insertions(+)
 create mode 100644 userspace/dd/CMakeLists.txt
 create mode 100644 userspace/dd/main.cpp

diff --git a/userspace/CMakeLists.txt b/userspace/CMakeLists.txt
index 4378b15cb4..9c999277e0 100644
--- a/userspace/CMakeLists.txt
+++ b/userspace/CMakeLists.txt
@@ -4,6 +4,7 @@ project(userspace CXX)
 
 set(USERSPACE_PROJECTS
 	cat
+	dd
 	echo
 	id
 	init
diff --git a/userspace/dd/CMakeLists.txt b/userspace/dd/CMakeLists.txt
new file mode 100644
index 0000000000..5e88c86993
--- /dev/null
+++ b/userspace/dd/CMakeLists.txt
@@ -0,0 +1,17 @@
+cmake_minimum_required(VERSION 3.26)
+
+project(dd CXX)
+
+set(SOURCES
+	main.cpp
+)
+
+add_executable(dd ${SOURCES})
+target_compile_options(dd PUBLIC -O2 -g)
+target_link_libraries(dd PUBLIC libc)
+
+add_custom_target(dd-install
+	COMMAND sudo cp ${CMAKE_CURRENT_BINARY_DIR}/dd ${BANAN_BIN}/
+	DEPENDS dd
+	USES_TERMINAL
+)
diff --git a/userspace/dd/main.cpp b/userspace/dd/main.cpp
new file mode 100644
index 0000000000..cbc8d0363e
--- /dev/null
+++ b/userspace/dd/main.cpp
@@ -0,0 +1,137 @@
+#include <ctype.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define CURRENT_NS() ({ timespec ts; clock_gettime(CLOCK_MONOTONIC, &ts); ts.tv_sec * 1'000'000'000 + ts.tv_nsec; })
+
+int parse_int(const char* val)
+{
+	int result = 0;
+
+	const char* ptr = val;
+	while (*ptr)
+	{
+		if (!isdigit(*ptr))
+		{
+			fprintf(stderr, "invalid number: %s\n", val);
+			exit(1);
+		}
+		result = (result * 10) + (*ptr - '0');
+		*ptr++;
+	}
+
+	return result;
+}
+
+void print_time(uint64_t start_ns, uint64_t end_ns, int transfered)
+{
+	static bool first = true;
+	uint64_t duration_ns = end_ns - start_ns;
+	printf("%s%d bytes copied, %d.%09d s\e[K\n", (first ? "" : "\e[F"), transfered, (int)(duration_ns / 1'000'000'000), (int)(duration_ns % 1'000'000'000));
+	first = false;
+}
+
+int main(int argc, char** argv)
+{
+	const char* input = nullptr;
+	const char* output = nullptr;
+	int bs = 512;
+	int count = -1;
+	bool print_progress = false;
+
+	for (int i = 1; i < argc; i++)
+	{
+		if (strncmp(argv[i], "if=", 3) == 0)
+			input = argv[i] + 3;
+		else if (strncmp(argv[i], "of=", 3) == 0)
+			output = argv[i] + 3;
+		else if (strncmp(argv[i], "bs=", 3) == 0)
+			bs = parse_int(argv[i] + 3);
+		else if (strncmp(argv[i], "count=", 6) == 0)
+			count = parse_int(argv[i] + 6);
+		else if (strcmp(argv[i], "status=progress") == 0)
+			print_progress = true;
+		else
+		{
+			fprintf(stderr, "unrecognized option: %s\n", argv[i]);
+			exit(1);
+		}
+	}
+
+	int ifd = STDIN_FILENO;
+	if (input)
+	{
+		ifd = open(input, O_RDONLY);
+		if (ifd == -1)
+		{
+			perror("open");
+			return 1;
+		}
+	}
+
+	int ofd = STDIN_FILENO;
+	if (output)
+	{
+		ofd = open(output, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+		if (ofd == -1)
+		{
+			perror("open");
+			return 1;
+		}
+	}
+
+	uint8_t* buffer = (uint8_t*)malloc(bs);
+	if (buffer == nullptr)
+	{
+		perror("malloc");
+		return 1;
+	}
+
+	size_t total_transfered = 0;
+
+	uint64_t start_ns = CURRENT_NS();
+	uint64_t last_print_ns = 0;
+
+	for (int i = 0; i != count; i++)
+	{
+		ssize_t nread = read(ifd, buffer, bs);
+		if (nread == -1)
+		{
+			perror("read");
+			return 1;
+		}
+
+		ssize_t nwrite = write(ofd, buffer, nread);
+		if (nwrite == -1)
+		{
+			perror("write");
+			return 1;
+		}
+
+		total_transfered += nwrite;
+
+		if (nread < bs || nwrite < bs)
+			break;
+
+		if (print_progress)
+		{
+			uint64_t current_ns = CURRENT_NS();
+			if (current_ns >= last_print_ns + 1'000'000'000)
+			{
+				print_time(start_ns, current_ns, total_transfered);
+				last_print_ns = current_ns;
+			}
+		}
+	}
+
+	print_time(start_ns, CURRENT_NS(), total_transfered);
+
+	close(ifd);
+	close(ofd);
+	free(buffer);
+
+	return 0;
+}