From 30458088f0f6acbb9581fecd2aa39d97c13d7373 Mon Sep 17 00:00:00 2001
From: cflip <cflip@cflip.net>
Date: Sat, 27 May 2023 11:50:37 -0600
Subject: Load and serve files from the filesystem

---
 cfws.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------
 http.c |  5 ++---
 http.h |  5 ++++-
 3 files changed, 64 insertions(+), 12 deletions(-)

diff --git a/cfws.c b/cfws.c
index bc9d0fa..63a6b19 100644
--- a/cfws.c
+++ b/cfws.c
@@ -1,4 +1,6 @@
 #include <arpa/inet.h>
+#include <errno.h>
+#include <linux/limits.h>
 #include <netdb.h>
 #include <signal.h>
 #include <stdio.h>
@@ -6,6 +8,7 @@
 #include <string.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>
+#include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -17,6 +20,8 @@
 
 #define CFWS_DEFAULT_PORT 8080
 
+size_t file_read(const char *, char **);
+
 int  initialize_server(int);
 void handle_connection();
 
@@ -41,6 +46,44 @@ int main(int argc, char *argv[])
 	return 0;
 }
 
+size_t file_read(const char *uri_path, char **buffer)
+{
+	FILE *fp;
+	struct stat statbuf;
+	char path[PATH_MAX];
+	long len;
+
+	/* Prepend the current working directory to the uri path */
+	getcwd(path, PATH_MAX);
+	strncat(path, uri_path, PATH_MAX - 1);
+
+	/* Append 'index.html' to directory paths. */
+	stat(path, &statbuf);
+	if (S_ISDIR(statbuf.st_mode))
+		strcat(path, "index.html");
+
+	fp = fopen(path, "rb");
+	if (fp == NULL) {
+		/*
+		 * File not found is a very common and harmless error, so
+		 * there's no need to print it out every time.
+		 */
+		if (errno != ENOENT)
+			perror("Failed to open file");
+		return 0;
+	}
+
+	fseek(fp, 0, SEEK_END);
+	len = ftell(fp);
+	fseek(fp, 0, SEEK_SET);
+
+	*buffer = malloc(len);
+	fread(*buffer, 1, len, fp);
+
+	fclose(fp);
+	return len;
+}
+
 int initialize_server(int port)
 {
 	struct sockaddr_in addr;
@@ -81,8 +124,10 @@ int initialize_server(int port)
 
 void handle_connection(int connfd)
 {
-	char msgbuf[128];
-	char *resbuf;
+	char *content_buf;
+	size_t content_len, response_len;
+
+	char resbuf[CFWS_MAX_RESPONSE];
 	char readbuf[CFWS_MAXREAD];
 	struct http_request req;
 
@@ -91,12 +136,17 @@ void handle_connection(int connfd)
 
 	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));
+	content_len = file_read(req.uri, &content_buf);
+	if (content_len == 0) {
+		const char *msg = "Could not find the specified file.";
+		response_len = http_build_response(resbuf,
+				HTTP_RESPONSE_NOTFOUND, msg, strlen(msg));
+	} else {
+		response_len = http_build_response(resbuf, HTTP_RESPONSE_OK,
+				content_buf, content_len);
+		free(content_buf);
+	}
 
-	free(resbuf);
+	write(connfd, resbuf, response_len);
 	http_free_request(&req);
 }
-
diff --git a/http.c b/http.c
index d6f495d..b6bad8e 100644
--- a/http.c
+++ b/http.c
@@ -30,8 +30,7 @@ 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)
+int http_build_response(char *res, enum http_res_code code, const char *msg, size_t msglen)
 {
-	*res = malloc(128);
-	sprintf(*res, "HTTP/1.1 200 OK\r\n\r\n%s\r\n", msg);
+	return snprintf(res, CFWS_MAX_RESPONSE, "HTTP/1.1 200 OK\r\n\r\n%.*s\r\n", msglen, msg);
 }
diff --git a/http.h b/http.h
index b39e271..1e97820 100644
--- a/http.h
+++ b/http.h
@@ -1,7 +1,10 @@
 #ifndef _H_HTTP
 #define _H_HTTP
 
+#include <stddef.h>
+
 #define CFWS_MAXURI  128
+#define CFWS_MAX_RESPONSE 4096
 
 enum http_req_method {
 	HTTP_METHOD_GET
@@ -20,6 +23,6 @@ struct http_request {
 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 *);
+int http_build_response(char *, enum http_res_code, const char *, size_t);
 
 #endif
-- 
cgit v1.2.3