Dev

Makefile

@@ -7,7 +7,7 @@ serve_cov: serve.c
 	gcc serve.c -o serve_cov -Wall -Wextra -O2 -fprofile-arcs -ftest-coverage -lgcov
 
 serve: serve.c
-	gcc serve.c -o serve -Wall -Wextra -O2 -DNDEBUG
+	gcc serve.c -o serve -Wall -Wextra -O2 -DNDEBUG -DRELEASE
 
 report: 
 	lcov --capture --directory . --output-file coverage.info

README.md

@@ -10,4 +10,8 @@ This is a minimal web server designed to serve my blog. I'm writing it to be rob
 - Single core (This will probably change when I get a better VPS)
 
 # How I test it
-I'm still testing manually. I usually stress test the server locally using `wrk` and see if it breaks. I also test it under `valgrind` and sanitizers.
+I'm still testing manually. I usually stress test the server locally using `wrk` and see if it breaks. I also test it under `valgrind` and sanitizers.
+
+# Known Issues
+- Server replies to HTTP/1.0 clients as HTTP/1.1
+- Since poll is edge triggered, when the server is full and can't accept all new connections the remaining ones are left waiting until some other event wakes up poll()

serve.c

@@ -17,7 +17,14 @@
 #include <poll.h>
 #include <time.h>
 
+#ifdef RELEASE
+#define PORT 80
+#define LOG_DIRECTORY_SIZE_LIMIT_MB (25 * 1024)
+#else
 #define PORT 8080
+#define LOG_DIRECTORY_SIZE_LIMIT_MB 10
+#endif
+
 #define SHOW_IO 0
 #define SHOW_REQUESTS 1
 #define REQUEST_TIMEOUT_SEC 5
@@ -26,7 +33,6 @@
 #define LOG_BUFFER_SIZE (1<<20)
 #define LOG_BUFFER_LIMIT (1<<24)
 #define LOG_FLUSH_TIMEOUT_SEC 3
-#define LOG_DIRECTORY_SIZE_LIMIT_MB 10
 #define INPUT_BUFFER_LIMIT_MB 1
 
 #ifndef NDEBUG
@@ -327,7 +333,7 @@ int parse_request_head(string str, Request *request)
 
 char to_lower(char c)
 {
-    if (c >= 'A' || c <= 'Z')
+    if (c >= 'A' && c <= 'Z')
         return c - 'A' + 'a';
     else
         return c;
@@ -353,11 +359,13 @@ string trim(string s)
     size_t cur = 0;
     while (cur < s.size && is_space(s.data[cur]))
         cur++;
-    
+
     if (cur == s.size) {
         s.data = "";
         s.size = 0;
     } else {
+		s.data += cur;
+		s.size -= cur;
         while (is_space(s.data[s.size-1]))
             s.size--;
     }
@@ -711,6 +719,7 @@ typedef struct {
 	ByteQueue output;
 	int served_count;
 	bool closing;
+	bool keep_alive;
 	uint64_t creation_time;
 	uint64_t start_time;
 } Connection;
@@ -927,17 +936,29 @@ int num_conns = 0;
 
 bool should_keep_alive(Connection *conn)
 {
+	// Don't keep alive if the peer doesn't want to
+	if (conn->keep_alive == false) {
+		DEBUG("Not keeping alive because peer wants to close\n");
+		return false;
+	}
+
 	// Don't keep alive if the request is too old
-	if (now - conn->creation_time > CONNECTION_TIMEOUT_SEC * 1000)
+	if (now - conn->creation_time > CONNECTION_TIMEOUT_SEC * 1000) {
+		DEBUG("Not keeping alive because the connection is too old\n");
 		return false;
+	}
 
 	// Don't keep alive if we served a lot of requests to this connection
-	if (conn->served_count > 100)
+	if (conn->served_count > 100) {
+		DEBUG("Not keeping alive because too many requests were served using this connection\n");
 		return false;
+	}
 
 	// Don't keep alive if the server is more than 70% full
-	if (num_conns > 0.7 * MAX_CONNECTIONS)
+	if (num_conns > 0.7 * MAX_CONNECTIONS) {
+		DEBUG("Not keeping alive because the server is more than 70%% full\n");
 		return false;
+	}
 
 	return true;
 }
@@ -1053,7 +1074,21 @@ bool respond_to_available_requests(struct pollfd *polldata, Connection *conn)
 			break; // Request wasn't completely received yet
 
 		// Reset the request timer
-		conns->start_time = now;
+		conn->start_time = now;
+
+		conn->keep_alive = false;
+		string keep_alive_header;
+		if (find_header(&request, LIT("Connection"), &keep_alive_header)) {
+			DEBUG("Found Connection header\n");
+			if (string_match_case_insensitive(trim(keep_alive_header), LIT("Keep-Alive"))) {
+				conn->keep_alive = true;
+				DEBUG("Matched Keep-Alive (%.*s)\n", (int) trim(keep_alive_header).size, trim(keep_alive_header).data);
+			} else {
+				DEBUG("Didn't match Keep-Alive (%.*s)\n", (int) trim(keep_alive_header).size, trim(keep_alive_header).data);
+			}
+		} else {
+			DEBUG("No Connection header\n");
+		}
 
 		// Respond
 		ResponseBuilder builder;
@@ -1069,6 +1104,11 @@ bool respond_to_available_requests(struct pollfd *polldata, Connection *conn)
 				polldata->events |= POLLOUT;
 				polldata->revents |= POLLOUT;
 			}
+			if (!conn->keep_alive) {
+				polldata->events &= ~POLLIN;
+				conn->closing = true;
+				conn->start_time = now;
+			}
 
 			pipeline_count++;
 			if (pipeline_count == 10) {
@@ -1154,6 +1194,9 @@ bool write_to_socket(int fd, ByteQueue *queue)
 
 int main(int argc, char **argv)
 {
+	(void) argc;
+	(void) argv;
+
 	signal(SIGTERM, handle_sigterm);
 	signal(SIGQUIT, handle_sigterm);
 	signal(SIGINT,  handle_sigterm);
@@ -1277,16 +1320,22 @@ int main(int argc, char **argv)
 					log_data(LIT("Closing timeout\n"));
 				} else {
 					// Request timeout
-					byte_queue_write(&conn->output, LIT(
-						"HTTP/1.1 408 Request Timeout\r\n"
-						"Connection: Close\r\n"
-						"\r\n"));
-					conn->closing = true;
-					conn->start_time = now;
-					pollarray[i].events &= ~POLLIN;
-					pollarray[i].events |= POLLOUT;
-					pollarray[i].revents |= POLLOUT;
-					log_data(LIT("Request timeout\n"));
+					if (byte_queue_size(&conn->input) == 0) {
+						// Connection was idle, so just close it
+						remove = true;
+						log_data(LIT("Idle connection timeout\n"));
+					} else {
+						byte_queue_write(&conn->output, LIT(
+							"HTTP/1.1 408 Request Timeout\r\n"
+							"Connection: Close\r\n"
+							"\r\n"));
+						conn->closing = true;
+						conn->start_time = now;
+						pollarray[i].events &= ~POLLIN;
+						pollarray[i].events |= POLLOUT;
+						pollarray[i].revents |= POLLOUT;
+						log_data(LIT("Request timeout\n"));
+					}
 				}
 
 			} else if (!remove && (pollarray[i].revents & POLLIN)) {

tests/test.py

@@ -6,25 +6,24 @@
 
 @dataclass
 class Delay:
-	ms: int
+	ms: float
 
 @dataclass
 class Send:
 	data: bytes
-	timeout: Optional[int] = None
+	timeout: Optional[float] = None
 
 @dataclass
 class Recv:
 	data: bytes
-	timeout: Optional[int] = None
+	timeout: Optional[float] = None
 
 @dataclass
 class Close:
 	pass
 
 def print_bytes(prefix, data):
-	lines = str(data).split("\r\n")
-	print(prefix, f"\\r\\n\n{prefix}".join(lines), sep="")
+	print(prefix, f"\\r\\n\n{prefix}".join(data.decode("utf-8").split("\r\n")), sep="")
 
 def run_test(test, addr, port):
 
@@ -44,7 +43,7 @@ def run_test(test, addr, port):
 					n = conn.send(data[sent:])
 					if n == 0:
 						break
-					#print_bytes("< ", data[sent:sent+n])
+					print_bytes("< ", data[sent:sent+n])
 					sent += n
 
 			case Recv(data, timeout):
@@ -54,7 +53,7 @@ def run_test(test, addr, port):
 					chunk = conn.recv(len(data) - count)
 					if chunk == b"":
 						break
-					#print_bytes("> ", chunk)
+					print_bytes("> ", chunk)
 					chunks.append(chunk)
 					count += len(chunk)
 				received = b''.join(chunks)
@@ -69,31 +68,66 @@ def run_test(test, addr, port):
 			case _:
 				pass
 
+
 tests = [
 	[
+		# Test "Connection: Close"
 		Send(b"GET / HTTP/1.1\r\nConnection: Close\r\n\r\n"),
-		Recv(b"HTTP/1.1 404 Not Found\r\nConnection: Close\r\n\r\n"),
+		Recv(b"HTTP/1.1 404 Not Found\r\nConnection: Close\r\nContent-Length: 15       \r\n\r\nNothing here :|"),
 		Close(),
 	],
 	[
+		# Test "Connection: Keep-Alive"
 		Send(b"GET / HTTP/1.1\r\nConnection: Keep-Alive\r\n\r\n"),
 		Recv(b"HTTP/1.1 404 Not Found\r\nConnection: Keep-Alive\r\nContent-Length: 15       \r\n\r\nNothing here :|"),
+		Send(b"GET / HTTP/1.1\r\nConnection: Close\r\n\r\n"),
+		Recv(b"HTTP/1.1 404 Not Found\r\nConnection: Close\r\nContent-Length: 15       \r\n\r\nNothing here :|"),
+		Close(),
+	],
+	[
+		# Test that the connection header is insensitive to case and whitespace
+		Send(b"GET / HTTP/1.1\r\nConnection:   keEp-ALiVE   \r\n\r\n"),
+		Recv(b"HTTP/1.1 404 Not Found\r\nConnection: Keep-Alive\r\nContent-Length: 15       \r\n\r\nNothing here :|"),
+		Send(b"GET / HTTP/1.1\r\nConnection: closE\r\n\r\n"),
+		Recv(b"HTTP/1.1 404 Not Found\r\nConnection: Close\r\nContent-Length: 15       \r\n\r\nNothing here :|"),
+		Close(),
 	],
 	[
 		Send(b"XXX\r\n\r\n"),
 		Recv(b"HTTP/1.1 400 Bad Request\r\nConnection: Close\r\n\r\n"),
 	],
+	[
+		Send(b"GET /hello HTTP/1.1\r\nConnection: Keep-Alive\r\n\r\n"),
+		Recv(b"HTTP/1.1 200 OK\r\nConnection: Keep-Alive\r\nContent-Length: 13       \r\n\r\nHello, world!"),
+	],
+	[
+		# Test request timeout
+		Send(b"GET /hel"),
+		Delay(6),
+		Recv(b"HTTP/1.1 408 Request Timeout\r\nConnection: Close\r\n\r\n"),
+		Close()
+	],
+	[
+		# Test idle connection timeout
+		Delay(6),
+		Close()
+	],
 ]
 
 p = subprocess.Popen(['../serve_cov'], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
 
 time.sleep(0.5)
 
+total = 0
+passed = 0
 for i, test in enumerate(tests):
 	try:
 		run_test(test, "127.0.0.1", 8080)
+		print("Test", i, "passed\n")
+		passed += 1
 	except Exception as e:
-		print("Test", i, "failed:", e.with_traceback(None))
-
+		print("Test", i, "failed:", e.with_traceback(None), "\n")
+	total += 1
+print("passed: ", passed, "/", total, sep="")
 p.terminate()
 p.wait()