cgi handler nearly finished

Makefile

@@ -5,7 +5,7 @@ LDFLAGS  = -lpthread -lrt
 
 BIN_NAME = cfloor
 
-OBJS     = obj/networking.o obj/linked.o obj/logging.o obj/signals.o obj/headers.o obj/misc.o obj/status.o obj/files.o obj/mime.o
+OBJS     = obj/networking.o obj/linked.o obj/logging.o obj/signals.o obj/headers.o obj/misc.o obj/status.o obj/files.o obj/mime.o obj/cgi.o
 DEPS     = $(OBJS:%.o=%.d)
 
 all: $(BIN_NAME)

src/cgi.c

@@ -0,0 +1,220 @@
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <sys/wait.h>
+
+#include "cgi.h"
+#include "misc.h"
+#include "files.h"
+#include "status.h"
+#include "logging.h"
+#include "headers.h"
+#define EXIT_EXEC_FAILED (255)
+
+static inline void setEnvStatic(const char* envname, const char* value) {
+	if (setenv(envname, value, true) < 0)
+		exit(EXIT_EXEC_FAILED);
+}
+
+static inline void setEnvFromHeader(struct headers* headers, const char* envname, const char* headerKey) {
+	const char* tmp = headers_get(headers, headerKey);
+	setEnvStatic(envname, tmp == NULL ? "" : tmp);
+}
+
+void cgiHandler(struct request request, struct response response) {
+	struct cgiSettings* settings = (struct cgiSettings*) request.userData.ptr;
+	const char* documentRoot = settings->documentRoot;
+
+	char* path = normalizePath(request, response, documentRoot);
+	if (path == NULL)
+		return;
+
+	if (access(path, F_OK | X_OK) < 0) {
+		free(path);
+		
+		switch(errno) {
+			case EACCES:
+				warn("cgi: file is not executable");
+				status(request, response, 403);
+				return;
+			default:
+				// this should not happen
+				error("cgi: Couldn't access file: %s", strerror(errno));
+				status(request, response, 500);
+				return;
+		}
+	}
+
+	int pipefd[2];
+
+	if (pipe(&(pipefd[0])) < 0) {
+		error("cgi: failed to create pipe: %s", strerror(errno));
+		status(request, response, 500);		
+
+		free(path);
+		return;
+	}
+
+	pid_t pid = fork();
+	if (pid < 0) {
+		error("cgi: failed to fork: %s", strerror(errno));
+		status(request, response, 500);
+	} else if (pid > 0) {
+		// child
+		// logging is thread-only
+		// so no logging from here on out.
+
+		if (dup2(request.fd, 0) < 0) {
+			exit(EXIT_EXEC_FAILED);
+		}
+		if (dup2(pipefd[1], 1) < 0) {
+			exit(EXIT_EXEC_FAILED);
+		}
+
+		struct headers* headers = request.headers;
+
+		setEnvStatic("GATEWAY_INTERFACE", "CGI/1.1");
+		setEnvStatic("DOCUMENT_ROOT", documentRoot);
+		setEnvStatic("HTTPS", request.bind.tls ? "on" : "off");
+		setEnvStatic("QUERY_STRING", request.metaData.queryString);
+		setEnvStatic("REQUEST_METHOD", methodString(request.metaData));
+		setEnvStatic("REQUEST_URI", request.metaData.uri);
+		setEnvStatic("REMOTE_ADDR", request.peer.addr);
+		setEnvStatic("REMOTE_HOST", request.peer.name);
+		setEnvStatic("REMOTE_PORT", request.peer.portStr);
+		setEnvStatic("SCRIPT_NAME", request.metaData.path);
+		setEnvStatic("SERVER_PROTOCOL", protocolString(request.metaData));
+
+		setEnvStatic("SERVER_NAME", ""); // TODO maybe bind addr?
+		setEnvStatic("SERVER_ADMIN", ""); // TODO
+		setEnvStatic("SERVER_ADDR", ""); // TODO
+		setEnvStatic("SERVER_PORT", ""); // TODO
+		setEnvStatic("SERVER_SIGNATURE", ""); // TODO
+		setEnvStatic("SERVER_SOFTWARE", ""); // TODO
+		
+		setEnvStatic("REDIRECT_REMOTE_USER", ""); // TODO not implemented
+		setEnvStatic("REMOTE_USER", ""); // TODO not implemented
+
+		setEnvFromHeader(headers, "HTTP_ACCEPT_CHARSET", "Accept-Charset");
+		setEnvFromHeader(headers, "HTTP_ACCEPT_ENCODING", "Accept-Encoding");
+		setEnvFromHeader(headers, "HTTP_ACCEPT_LANGUAGE", "Accept-Language");
+		setEnvFromHeader(headers, "HTTP_CONNECTION", "Accept-Connection");
+		setEnvFromHeader(headers, "HTTP_ACCEPT", "Accept");
+		setEnvFromHeader(headers, "HTTP_HOST", "Host");
+		setEnvFromHeader(headers, "HTTP_USER_AGENT", "User-Agent");
+		setEnvFromHeader(headers, "HTTP_COOKIE", "Cookie");
+		setEnvFromHeader(headers, "CONTENT_TYPE", "Content-Type");
+		setEnvFromHeader(headers, "CONTENT_LENGTH", "Content-Length");
+		
+		execl(path, path, NULL);
+
+		exit(EXIT_EXEC_FAILED);
+	} else {
+		// parent
+		info("cgi: child started successfully");
+		
+		#define LOCAL_BUFFER_LENGTH (512)
+
+		char buffer[LOCAL_BUFFER_LENGTH];
+		int bufferIndex = 0;
+
+		int statusCode = 0;
+		bool wasLineEnd = false;
+		bool finished = false;
+
+		struct headers headers = headers_create();
+
+		char c;
+		while((read(pipefd[0], &c, 1)) > 0) {
+			bool malformed = false;
+
+			if (bufferIndex >= LOCAL_BUFFER_LENGTH - 1)
+				malformed = true;
+			else if (c == '\r')
+				continue;
+			else if (c == '\n') {
+				if (wasLineEnd) {
+					finished = true;
+					break;
+				}
+
+				buffer[bufferIndex] = '\0';
+				bufferIndex = 0;
+
+				if (statusCode == 0) {
+					char* endptr;
+
+					statusCode = strtol(&(buffer[0]), &endptr, 10);
+
+					if (endptr != '\0') {
+						malformed = true;
+					}
+				} else {
+					if (headers_parse(&headers, &(buffer[0]), bufferIndex) < 0) {
+						malformed = true;
+					}
+				}
+
+				wasLineEnd = true;
+			} else {
+				wasLineEnd = false;
+
+				buffer[bufferIndex++] = c;
+			}
+
+			if (malformed) {
+				error("cgi: response malformed");
+
+				finished = false;
+				break; 
+			}
+		}
+
+		if (!finished) {
+			error("cgi: error while reading header");
+
+			kill(pid, SIGTERM);
+			waitpid(pid, &statusCode, 0);
+
+			close(pipefd[0]);
+			close(pipefd[1]);
+
+			status(request, response, 500);
+			
+			free(path);
+			headers_free(&headers);
+			
+			return;
+		}
+	
+		close(pipefd[0]);
+
+		int fd = response.sendHeader(statusCode, &headers, &request);
+
+		headers_free(&headers);
+
+		// start copy thread
+
+		free(path);
+
+		if (waitpid(pid, &statusCode, 0) < 1) {
+			error("cgi: error while waiting for child: %s", strerror(errno));
+			status(request, response, 500);
+
+			free(path);
+			return;
+		}
+
+		// WIFEXISTED has to be true
+		statusCode = WEXITSTATUS(statusCode);
+
+		if (statusCode == EXIT_EXEC_FAILED) {
+			error("cgi: child exit code indicates that exec failed");
+			status(request, response, 500);
+
+			return;
+		}
+	}
+}

src/cgi.h

@@ -0,0 +1,12 @@
+#ifndef CGI_H
+#define CGI_H
+
+#include "misc.h"
+
+struct cgiSettings {
+	const char* documentRoot;
+};
+
+void cgiHandler(struct request, struct response);
+
+#endif