Begin rewriting cfws in C

15 files changed, 174 insertions, 519 deletions

diff --git a/Makefile b/Makefile
index feaf3e3..81c0b3d 100644
--- a/Makefile
+++ b/Makefile
@@ -1,31 +1,25 @@
-CXX=g++
-LD=g++
+CC=gcc
+LD=gcc
 
-CFLAGS=-pedantic -Wall --std=c++17
+CFLAGS=-Wall -Wextra -pedantic -std=c89
+LDFLAGS=
 
-OBJS=src/main.o \
-    src/CGIScript.o \
-    src/ClientConnection.o \
-    src/ServerConnection.o \
-    src/HttpRequest.o \
-    src/HttpResponse.o
+OBJS=cfws.o http.o
 
 DESTDIR=/usr/local/bin/
 
+.PHONY: all clean install
+
 all: cfws
 
-%.o: %.cpp
-	$(CXX) $< -o $@ -c $(CFLAGS)
+%.o: %.c
+	$(CC) $(CFLAGS) -c $< -o $@
 
 cfws: $(OBJS)
-	$(LD) $^ -o $@ $(CFLAGS)
-
-.PHONY: clean
+	$(LD) $(LDFLAGS) $^ -o $@
 
 clean:
 	rm -f $(OBJS) cfws
 
-.PHONY: install
-
 install: all
 	install -m 0755 ./cfws -t $(DESTDIR)
diff --git a/cfws.c b/cfws.c
new file mode 100644
index 0000000..bc9d0fa
--- /dev/null
+++ b/cfws.c
@@ -0,0 +1,102 @@
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "http.h"
+
+#define CFWS_MAXCONN 10   /* Max connections allowed by listen(). */
+#define CFWS_MAXREAD 1024 /* Size of buffer used for reading from client. */
+
+#define CFWS_DEFAULT_PORT 8080
+
+int  initialize_server(int);
+void handle_connection();
+
+int main(int argc, char *argv[])
+{
+	int port = CFWS_DEFAULT_PORT;
+	int serverfd, clientfd;
+
+	serverfd = initialize_server(port);
+	if (serverfd == -1)
+		return 1;
+
+	printf("Serving a directory at localhost:%d\n", port);
+
+	while (1) {
+		clientfd = accept(serverfd, NULL, NULL);
+		handle_connection(clientfd);
+		close(clientfd);
+	}
+
+	close(serverfd);
+	return 0;
+}
+
+int initialize_server(int port)
+{
+	struct sockaddr_in addr;
+	int rc;
+	int sockopts = 1;
+	int sockfd;
+
+	sockfd = socket(AF_INET, SOCK_STREAM, 0);
+	if (sockfd == -1) {
+		perror("Failed to create server socket");
+		return -1;
+	}
+
+	/* Allow the port to be reused, prevents errors when quickly starting
+	 * and restarting the server. */
+	/* TODO: Also use SO_REUSEPORT? */
+	setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &sockopts, sizeof(int));
+
+	memset(&addr, 0, sizeof(struct sockaddr_in));
+	addr.sin_family      = AF_INET;
+	addr.sin_addr.s_addr = htonl(INADDR_ANY);
+	addr.sin_port        = htons(port);
+
+	rc = bind(sockfd, (struct sockaddr*)&addr, sizeof(struct sockaddr));
+	if (rc == -1) {
+		perror("Failed to bind server socket");
+		return -1;
+	}
+
+	rc = listen(sockfd, CFWS_MAXCONN);
+	if (rc == -1) {
+		perror("Failed to listen on server socket");
+		return -1;
+	}
+
+	return sockfd;
+}
+
+void handle_connection(int connfd)
+{
+	char msgbuf[128];
+	char *resbuf;
+	char readbuf[CFWS_MAXREAD];
+	struct http_request req;
+
+	memset(readbuf, 0, CFWS_MAXREAD);
+	read(connfd, readbuf, CFWS_MAXREAD - 1);
+
+	req = http_parse_request(readbuf);
+
+	snprintf(msgbuf, 128, "Welcome to %s", req.uri);
+
+	http_build_response(&resbuf, HTTP_RESPONSE_OK, msgbuf);
+	write(connfd, resbuf, strlen(resbuf));
+
+	free(resbuf);
+	http_free_request(&req);
+}
+
diff --git a/http.c b/http.c
new file mode 100644
index 0000000..d6f495d
--- /dev/null
+++ b/http.c
@@ -0,0 +1,37 @@
+#include "http.h"
+
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct http_request http_parse_request(const char *reqstr)
+{
+	struct http_request req;
+	char uribuf[CFWS_MAXURI];
+	size_t urilen;
+
+	sscanf(reqstr, "GET %s HTTP/1.1", uribuf);
+
+	/* TODO: Support other method types, notably POST */
+	req.method = HTTP_METHOD_GET;
+
+	urilen = strlen(uribuf);
+	req.uri = malloc(urilen + 1);
+	memcpy(req.uri, uribuf, urilen + 1);
+	
+	/* TODO: Parse request headers */
+
+	return req;
+}
+
+void http_free_request(struct http_request *req)
+{
+	free(req->uri);
+}
+
+void http_build_response(char **res, enum http_res_code code, const char *msg)
+{
+	*res = malloc(128);
+	sprintf(*res, "HTTP/1.1 200 OK\r\n\r\n%s\r\n", msg);
+}
diff --git a/http.h b/http.h
new file mode 100644
index 0000000..b39e271
--- /dev/null
+++ b/http.h
@@ -0,0 +1,25 @@
+#ifndef _H_HTTP
+#define _H_HTTP
+
+#define CFWS_MAXURI  128
+
+enum http_req_method {
+	HTTP_METHOD_GET
+};
+
+enum http_res_code {
+	HTTP_RESPONSE_OK       = 200,
+	HTTP_RESPONSE_NOTFOUND = 404
+};
+
+struct http_request {
+	int method;
+	char *uri;
+};
+
+struct http_request http_parse_request(const char *);
+void http_free_request(struct http_request *);
+
+void http_build_response(char **, enum http_res_code, const char *);
+
+#endif
diff --git a/src/CGIScript.cpp b/src/CGIScript.cpp
deleted file mode 100644
index 3ef1f3f..0000000
--- a/src/CGIScript.cpp
+++ /dev/null
@@ -1,69 +0,0 @@
-#include "CGIScript.h"
-
-#include <cstdlib>
-#include <filesystem>
-#include <iostream>
-#include <sstream>
-#include <string>
-#include <unistd.h>
-
-CGIScript::CGIScript(const std::string& script_path)
-	: m_script_path(script_path)
-{
-	set_environment("SCRIPT_NAME", script_path.c_str());
-	set_environment("SCRIPT_FILENAME", script_path.c_str());
-	set_environment("SERVER_PROTOCOL", "HTTP/1.1");
-	set_environment("SERVER_SOFTWARE", "cfws");
-}
-
-CGIScript::~CGIScript()
-{
-	pclose(m_pipe);
-
-	for (const auto* key : m_environment_variables)
-		unsetenv(key);
-}
-
-void CGIScript::set_environment(const char* key, const char* value)
-{
-	m_environment_variables.push_back(key);
-	setenv(key, value, 1);
-}
-
-bool CGIScript::open()
-{
-	m_pipe = popen(m_script_path.c_str(), "r");
-	if (m_pipe == nullptr) {
-		perror("cfws: popen");
-		return false;
-	}
-
-	m_is_open = true;
-	return true;
-}
-
-std::string CGIScript::read_output()
-{
-	std::stringstream sstream;
-
-	char ch = 0;
-	while ((ch = fgetc(m_pipe)) != EOF)
-		sstream << ch;
-
-	return sstream.str();
-}
-
-void CGIScript::validate_path(const std::string& script_path)
-{
-	namespace fs = std::filesystem;
-
-	if (!fs::exists(script_path)) {
-		std::cerr << "cfws: Script not found: " << script_path << std::endl;
-		exit(1);
-	}
-
-	if (access(script_path.c_str(), X_OK)) {
-		std::cerr << "cfws: Script does not have execute permissions: " << script_path << std::endl;
-		exit(1);
-	}
-}
diff --git a/src/CGIScript.h b/src/CGIScript.h
deleted file mode 100644
index 3ac00d9..0000000
--- a/src/CGIScript.h
+++ /dev/null
@@ -1,25 +0,0 @@
-#pragma once
-
-#include <cstdio>
-#include <string>
-#include <vector>
-
-class CGIScript {
-public:
-	CGIScript(const std::string& script_path);
-	~CGIScript();
-
-	void set_environment(const char* key, const char* value);
-	bool open();
-
-	std::string read_output();
-
-	static void validate_path(const std::string& path);
-
-private:
-	FILE* m_pipe {};
-	const std::string& m_script_path;
-	bool m_is_open { false };
-
-	std::vector<const char*> m_environment_variables;
-};
diff --git a/src/ClientConnection.cpp b/src/ClientConnection.cpp
deleted file mode 100644
index c434212..0000000
--- a/src/ClientConnection.cpp
+++ /dev/null
@@ -1,47 +0,0 @@
-#include "ClientConnection.h"
-
-#include <cstring>
-#include <iostream>
-#include <sstream>
-#include <unistd.h>
-
-ClientConnection::ClientConnection(int socket)
-	: m_socket_fd(socket)
-{
-}
-
-HttpRequest ClientConnection::read_request() const
-{
-	// TODO: Clean up this code to ensure it works with multiple lines
-	//       and not risk a buffer overflow.
-	constexpr int BUFFER_SIZE = 4096;
-	char buffer[BUFFER_SIZE + 1];
-	int n = 0;
-
-	memset(buffer, 0, BUFFER_SIZE);
-	while ((n = read(m_socket_fd, buffer, BUFFER_SIZE - 1)) > 0) {
-		if (buffer[n - 1] == '\n')
-			break;
-
-		memset(buffer, 0, BUFFER_SIZE);
-	}
-
-	return HttpRequest(buffer);
-}
-
-bool ClientConnection::send(const HttpResponse& response) const
-{
-	if (!m_is_open)
-		return false;
-
-	std::string result = response.to_string();
-	write(m_socket_fd, result.c_str(), result.length());
-
-	return true;
-}
-
-void ClientConnection::close_connection()
-{
-	m_is_open = false;
-	close(m_socket_fd);
-}
diff --git a/src/ClientConnection.h b/src/ClientConnection.h
deleted file mode 100644
index fee0aeb..0000000
--- a/src/ClientConnection.h
+++ /dev/null
@@ -1,18 +0,0 @@
-#pragma once
-
-#include "HttpRequest.h"
-#include "HttpResponse.h"
-
-class ClientConnection {
-public:
-	ClientConnection(int socket);
-
-	HttpRequest read_request() const;
-
-	bool send(const HttpResponse&) const;
-	void close_connection();
-
-private:
-	int m_socket_fd;
-	bool m_is_open { true };
-};
diff --git a/src/HttpRequest.cpp b/src/HttpRequest.cpp
deleted file mode 100644
index 37c85fd..0000000
--- a/src/HttpRequest.cpp
+++ /dev/null
@@ -1,28 +0,0 @@
-#include "HttpRequest.h"
-
-#include <iostream>
-
-HttpRequest::HttpRequest(const std::string& request_string)
-{
-	size_t pos = 0;
-	std::string s = request_string;
-	std::string line;
-	while ((pos = s.find("\r\n")) != std::string::npos) {
-		line = s.substr(0, pos);
-
-		if (line.find("GET ") != std::string::npos) {
-			m_uri = s.substr(4, line.find(' ', 5) - 4);
-			std::cout << m_uri << std::endl;
-		}
-
-		// If the line contains a colon, we assume it's a header.
-		// TODO: This may not always be the case.
-		size_t delim_pos = 0;
-		if ((delim_pos = line.find(':')) != std::string::npos) {
-			std::string header_key = s.substr(0, delim_pos);
-			std::string header_value = s.substr(delim_pos + 2, s.find("\r\n") - delim_pos - 2);
-			m_headers[header_key] = header_value;
-		}
-		s.erase(0, pos + 2);
-	}
-}
diff --git a/src/HttpRequest.h b/src/HttpRequest.h
deleted file mode 100644
index cb98bea..0000000
--- a/src/HttpRequest.h
+++ /dev/null
@@ -1,16 +0,0 @@
-#pragma once
-
-#include <map>
-#include <string>
-
-class HttpRequest {
-public:
-	HttpRequest(const std::string& request_string);
-
-	std::string uri() const { return m_uri; }
-	std::string header(const std::string& header_key) const { return m_headers.at(header_key); };
-
-private:
-	std::map<std::string, std::string> m_headers;
-	std::string m_uri;
-};
diff --git a/src/HttpResponse.cpp b/src/HttpResponse.cpp
deleted file mode 100644
index c8afc63..0000000
--- a/src/HttpResponse.cpp
+++ /dev/null
@@ -1,55 +0,0 @@
-#include "HttpResponse.h"
-
-#include <sstream>
-
-void HttpResponse::add_headers_and_content(const std::string& input)
-{
-	bool is_parsing_headers = true;
-
-	size_t pos = 0;
-	std::string s = input;
-	std::string line;
-	while ((pos = s.find('\n')) != std::string::npos) {
-		line = s.substr(0, pos + 1);
-
-		if (is_parsing_headers) {
-			size_t delim_pos = 0;
-			if ((delim_pos = line.find(':')) != std::string::npos) {
-				std::string header_key = s.substr(0, delim_pos);
-				std::string header_value = s.substr(delim_pos + 2, s.find('\n') - delim_pos - 2);
-				m_headers[header_key] = header_value;
-			} else {
-				is_parsing_headers = false;
-			}
-		} else {
-			m_content += line;
-		}
-		s.erase(0, pos + 1);
-	}
-}
-
-static std::string status_code_string(HttpStatusCode status_code)
-{
-	switch (status_code) {
-	case HttpStatusCode::OK:
-		return "200 OK";
-	case HttpStatusCode::Forbidden:
-		return "403 Forbidden";
-	case HttpStatusCode::NotFound:
-		return "404 Not Found";
-	case HttpStatusCode::InternalServerError:
-		return "500 Internal Server Error";
-	}
-}
-
-std::string HttpResponse::to_string() const
-{
-	std::stringstream string_stream;
-	string_stream << "HTTP/1.0 " << status_code_string(m_status_code) << "\r\n";
-	for (const auto& header : m_headers)
-		string_stream << header.first << ": " << header.second << "\r\n";
-	string_stream << "\r\n"
-				  << m_content;
-
-	return string_stream.str();
-}
diff --git a/src/HttpResponse.h b/src/HttpResponse.h
deleted file mode 100644
index b55e01a..0000000
--- a/src/HttpResponse.h
+++ /dev/null
@@ -1,30 +0,0 @@
-#pragma once
-
-#include <map>
-#include <string>
-
-enum class HttpStatusCode {
-	OK = 200,
-	Forbidden = 403,
-	NotFound = 404,
-	InternalServerError = 500,
-};
-
-class HttpResponse {
-public:
-	void add_header(const std::string& header, const std::string& value)
-	{
-		m_headers[header] = value;
-	}
-
-	void set_status_code(HttpStatusCode status_code) { m_status_code = status_code; }
-	void set_content(const std::string& content) { m_content = content; }
-	void add_headers_and_content(const std::string&);
-
-	std::string to_string() const;
-
-private:
-	HttpStatusCode m_status_code;
-	std::map<std::string, std::string> m_headers;
-	std::string m_content;
-};
diff --git a/src/ServerConnection.cpp b/src/ServerConnection.cpp
deleted file mode 100644
index 64692b6..0000000
--- a/src/ServerConnection.cpp
+++ /dev/null
@@ -1,46 +0,0 @@
-#include "ServerConnection.h"
-
-#include <arpa/inet.h>
-#include <csignal>
-#include <netdb.h>
-#include <sys/ioctl.h>
-#include <sys/socket.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <unistd.h>
-
-#include "ClientConnection.h"
-
-static void error_and_die(const char* message)
-{
-	perror(message);
-	exit(1);
-}
-
-ServerConnection::ServerConnection(int port)
-{
-	sockaddr_in address {};
-	int socket_options = 1;
-
-	if ((m_socket_fd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
-		error_and_die("Failed to create socket");
-
-	if (setsockopt(m_socket_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &socket_options, sizeof(socket_options)) != 0)
-		error_and_die("setsockopt");
-
-	address.sin_family = AF_INET;
-	address.sin_addr.s_addr = htonl(INADDR_ANY);
-	address.sin_port = htons(port);
-
-	if ((bind(m_socket_fd, (sockaddr*)&address, sizeof(address))) < 0)
-		error_and_die("bind");
-
-	if ((listen(m_socket_fd, 10)) < 0)
-		error_and_die("listen");
-}
-
-ClientConnection ServerConnection::accept_client_connection() const
-{
-	int client_socket = accept(m_socket_fd, (sockaddr*)nullptr, nullptr);
-	return { client_socket };
-}
diff --git a/src/ServerConnection.h b/src/ServerConnection.h
deleted file mode 100644
index 8f0af70..0000000
--- a/src/ServerConnection.h
+++ /dev/null
@@ -1,13 +0,0 @@
-#pragma once
-
-class ClientConnection;
-
-class ServerConnection {
-public:
-	ServerConnection(int port);
-
-	ClientConnection accept_client_connection() const;
-
-private:
-	int m_socket_fd;
-};
diff --git a/src/main.cpp b/src/main.cpp
deleted file mode 100644
index c0c9bb3..0000000
--- a/src/main.cpp
+++ /dev/null
@@ -1,156 +0,0 @@
-#include <getopt.h>
-
-#include <filesystem>
-#include <fstream>
-#include <iostream>
-#include <sstream>
-
-#include "CGIScript.h"
-#include "ClientConnection.h"
-#include "HttpRequest.h"
-#include "HttpResponse.h"
-#include "ServerConnection.h"
-
-static std::string content_type_for_extension(const std::filesystem::path& extension)
-{
-	if (extension == ".html")
-		return "text/html";
-	if (extension == ".css")
-		return "text/css";
-	if (extension == ".gif")
-		return "image/gif";
-	if (extension == ".png")
-		return "image/png";
-	if (extension == ".webp")
-		return "image/webp";
-	return "text/plain";
-}
-
-static HttpResponse serve_from_filesystem(const HttpRequest& request)
-{
-	namespace fs = std::filesystem;
-
-	HttpResponse response;
-	response.add_header("Server", "cfws");
-
-	// Remove leading slash from the path if it exists
-	std::string relative_request_path = request.uri();
-	while (*relative_request_path.begin() == '/')
-		relative_request_path.erase(0, 1);
-
-	fs::path request_path = fs::current_path() / relative_request_path;
-
-	// Look for an index.html if the requested path is a directory
-	if (fs::is_directory(request_path)) {
-		request_path /= "index.html";
-	}
-
-	if (fs::exists(request_path)) {
-		std::string file_path = request_path.string();
-		std::ifstream input_file(file_path);
-		if (!input_file.is_open()) {
-			std::cerr << "Failed to open file " << file_path << std::endl;
-		}
-
-		std::string file_contents((std::istreambuf_iterator<char>(input_file)), std::istreambuf_iterator<char>());
-
-		response.set_status_code(HttpStatusCode::OK);
-		response.add_header("Content-Type", content_type_for_extension(request_path.extension()));
-		response.set_content(file_contents);
-	} else {
-		response.set_status_code(HttpStatusCode::NotFound);
-		response.add_header("Content-Type", "text/plain");
-		response.set_content("Page not found!");
-	}
-
-	return response;
-}
-
-static HttpResponse serve_from_cgi(const std::string& script_path, const HttpRequest& request)
-{
-	HttpResponse response;
-	response.add_header("Server", "cfws");
-
-	// Split URI between the path and the query parameter string
-	std::stringstream uri_stream(request.uri());
-	std::string segment;
-	std::vector<std::string> segment_list;
-
-	while (std::getline(uri_stream, segment, '?')) {
-		segment_list.push_back(segment);
-	}
-
-	CGIScript script(script_path);
-	script.set_environment("REQUEST_METHOD", "GET");
-	script.set_environment("REQUEST_URI", request.uri().c_str());
-	script.set_environment("PATH_INFO", segment_list[0].c_str());
-	if (segment_list.size() > 1)
-		script.set_environment("QUERY_STRING", segment_list[1].c_str());
-	script.set_environment("CONTENT_LENGTH", "0");
-
-	if (!script.open()) {
-		response.set_status_code(HttpStatusCode::InternalServerError);
-		response.add_header("Content-Type", "text/plain");
-		response.set_content("Failed to open CGI script!");
-		return response;
-	}
-
-	response.set_status_code(HttpStatusCode::OK);
-	response.add_headers_and_content(script.read_output());
-	return response;
-}
-
-static option long_options[] = {
-	{ "cgi", required_argument, nullptr, 'c' },
-	{ "port", required_argument, nullptr, 'p' },
-};
-
-int main(int argc, char** argv)
-{
-	int port = 8080;
-	bool in_cgi_mode = false;
-	std::string cgi_program_name;
-
-	int c = 0;
-	int option_index = 0;
-	while ((c = getopt_long(argc, argv, "c:p:", long_options, &option_index)) != -1) {
-		switch (c) {
-		case 'c':
-			in_cgi_mode = true;
-			cgi_program_name = optarg;
-			break;
-		case 'p':
-			port = atoi(optarg);
-			if (port == 0) {
-				std::cerr << "cfws: Specified port is not a valid number" << std::endl;
-				exit(1);
-			}
-			break;
-		default:
-			break;
-		}
-	}
-
-	// Check the script path to ensure that it is a valid executable
-	// script before attempting to start the server.
-	if (in_cgi_mode)
-		CGIScript::validate_path(cgi_program_name);
-
-	ServerConnection server(port);
-	std::cout << "Serving a " << (in_cgi_mode ? "CGI script" : "directory") << " on port " << port << std::endl;
-
-	while (true) {
-		ClientConnection client = server.accept_client_connection();
-		HttpRequest request = client.read_request();
-		HttpResponse response;
-
-		if (in_cgi_mode) {
-			response = serve_from_cgi(cgi_program_name, request);
-		} else {
-			response = serve_from_filesystem(request);
-		}
-
-		client.send(response);
-		client.close_connection();
-	}
-}