feat: simple echoing server

c-web-server
Jef Roosens 2023-05-24 14:49:08 +02:00
parent a163ee5155
commit 80e972ff54
Signed by: Jef Roosens
GPG Key ID: B75D4F293C7052DB
3 changed files with 62 additions and 20 deletions

View File

@ -13,9 +13,6 @@
#include "event_loop_internal.h" #include "event_loop_internal.h"
#include "picohttpparser.h" #include "picohttpparser.h"
const char http_200_ok[] = "HTTP/1.1 200 OK\n"
"Connection: close\n";
static int event_loop_fd_set_nb(int fd) { static int event_loop_fd_set_nb(int fd) {
int flags = fcntl(fd, F_GETFL, 0); int flags = fcntl(fd, F_GETFL, 0);
@ -101,6 +98,8 @@ int event_loop_accept(event_loop *loop, int fd) {
return -4; return -4;
} }
/* printf("New connection with fd %i\n", connfd); */
return 0; return 0;
} }
@ -176,6 +175,7 @@ void event_loop_run(event_loop *el, int port) {
// poll for active fds // poll for active fds
// the timeout argument doesn't matter here // the timeout argument doesn't matter here
int rv = poll(poll_args, (nfds_t)poll_args_count, 1000); int rv = poll(poll_args, (nfds_t)poll_args_count, 1000);
/* printf("poll"); */
if (rv < 0) { if (rv < 0) {
return; return;
@ -188,6 +188,7 @@ void event_loop_run(event_loop *el, int port) {
event_loop_conn_io(conn); event_loop_conn_io(conn);
if (conn->state == event_loop_conn_state_end) { if (conn->state == event_loop_conn_state_end) {
/* printf("free %i\n", conn->fd); */
// client closed normally, or something bad happened. // client closed normally, or something bad happened.
// destroy this connection // destroy this connection
el->connections[conn->fd] = NULL; el->connections[conn->fd] = NULL;

View File

@ -14,7 +14,9 @@
#include "event_loop_internal.h" #include "event_loop_internal.h"
bool event_loop_conn_write_to_fd(event_loop_conn *conn) { const char http_200_ok[] = "HTTP/1.1 200 OK\nConnection: close\nContent-Length: 5\n\nhello";
bool event_loop_conn_io_res(event_loop_conn *conn) {
ssize_t res = 0; ssize_t res = 0;
size_t remain = conn->wbuf_size - conn->wbuf_sent; size_t remain = conn->wbuf_size - conn->wbuf_sent;
@ -36,9 +38,10 @@ bool event_loop_conn_write_to_fd(event_loop_conn *conn) {
conn->wbuf_sent += (size_t)res; conn->wbuf_sent += (size_t)res;
// Everything is written from the buffer, so we exit // After writing a response, we switch back to request mode to process a next
// request
if (conn->wbuf_sent == conn->wbuf_size) { if (conn->wbuf_sent == conn->wbuf_size) {
conn->state = event_loop_conn_state_end; conn->state = conn->close_after_write ? event_loop_conn_state_end : event_loop_conn_state_req;
/* c->wbuf_sent = 0; */ /* c->wbuf_sent = 0; */
/* c->wbuf_size = 0; */ /* c->wbuf_size = 0; */
@ -49,12 +52,12 @@ bool event_loop_conn_write_to_fd(event_loop_conn *conn) {
return true; return true;
} }
void try_one_request(event_loop_conn *conn) { bool try_one_request(event_loop_conn *conn) {
if (conn->process_func != NULL) { /* if (conn->process_func != NULL) { */
conn->process_func(conn); /* conn->process_func(conn); */
} /* } */
char *method, *path; const char *method, *path;
struct phr_header headers[16]; struct phr_header headers[16];
size_t method_len, path_len, num_headers; size_t method_len, path_len, num_headers;
int minor_version; int minor_version;
@ -66,12 +69,38 @@ void try_one_request(event_loop_conn *conn) {
&minor_version, headers, &num_headers, 0); &minor_version, headers, &num_headers, 0);
if (res > 0) { if (res > 0) {
// TODO allow HTTP pipelining
conn->close_after_write = true;
/* for (int i = 0; i < num_headers; i++) { */
/* printf("%.*s: ", headers[i].name_len, headers[i].name); */
/* printf("%.*s\n", headers[i].value_len, headers[i].value); */
/* if (strncmp("Connection", headers[i].name, headers[i].name_len) == 0) { */
/* if (strncmp("close", headers[i].value, headers[i].value_len) == 0) { */
/* printf("close\n"); */
/* break; */
/* } */
/* } */
/* } */
} else if (res == -1) { memcpy(conn->wbuf, http_200_ok, sizeof(http_200_ok) - 1);
// Move the new request up to the front of the read buffer
memmove(conn->rbuf, &conn->rbuf[res], conn->rbuf_size - res);
conn->rbuf_size -= res;
conn->state = event_loop_conn_state_res;
conn->wbuf_size = sizeof(http_200_ok) - 1;
conn->wbuf_sent = 0;
event_loop_conn_io_res(conn);
// End the connection if the http request is invalid, or when the response
// is too large to fit into a single read buffer
} else if (res == -1 || (res == -2 && conn->rbuf_size == EVENT_LOOP_BUFFER_SIZE)) {
conn->state = event_loop_conn_state_end; conn->state = event_loop_conn_state_end;
} else if (res == -2) {
// We don't do anything here
} }
return conn->state == event_loop_conn_state_req;
} }
/** /**
@ -80,7 +109,7 @@ void try_one_request(event_loop_conn *conn) {
* *
* Returns whether the function should be retried immediately or not. * Returns whether the function should be retried immediately or not.
*/ */
bool event_loop_conn_read_from_fd(event_loop_conn *conn) { bool event_loop_conn_io_req(event_loop_conn *conn) {
ssize_t res; ssize_t res;
size_t cap = EVENT_LOOP_BUFFER_SIZE - conn->rbuf_size; size_t cap = EVENT_LOOP_BUFFER_SIZE - conn->rbuf_size;
@ -101,8 +130,11 @@ bool event_loop_conn_read_from_fd(event_loop_conn *conn) {
return false; return false;
} }
// An output of 0 zero means we've reached the end of the input // Output of 0 and no error means we've reached the end of the input. We run
// try_one_request one more time and close the connection if this doesn't
// change the result.
if (res == 0) { if (res == 0) {
conn->state = event_loop_conn_state_end;
} }
// We switch to processing mode if we've reached the end of the data stream, // We switch to processing mode if we've reached the end of the data stream,
@ -119,7 +151,7 @@ bool event_loop_conn_read_from_fd(event_loop_conn *conn) {
// Try to process requests one by one. // Try to process requests one by one.
// Try to process requests one by one. // Try to process requests one by one.
// Why is there a loop? Please read the explanation of "pipelining". // Why is there a loop? Please read the explanation of "pipelining".
try_one_request(conn); while (try_one_request(conn)) {};
// We can keep reading as long as we're in request mode // We can keep reading as long as we're in request mode
return conn->state == event_loop_conn_state_req; return conn->state == event_loop_conn_state_req;
@ -128,13 +160,14 @@ bool event_loop_conn_read_from_fd(event_loop_conn *conn) {
} }
void conn_state_res(event_loop_conn *conn) { void conn_state_res(event_loop_conn *conn) {
while (event_loop_conn_write_to_fd(conn)) { while (event_loop_conn_io_res(conn)) {
} }
} }
void conn_state_req(event_loop_conn *conn) { void conn_state_req(event_loop_conn *conn) {
while (event_loop_conn_read_from_fd(conn)) { while (event_loop_conn_io_req(conn)) {
} }
/* printf("done req"); */
} }
void event_loop_conn_io(event_loop_conn *conn) { void event_loop_conn_io(event_loop_conn *conn) {
@ -145,5 +178,8 @@ void event_loop_conn_io(event_loop_conn *conn) {
case event_loop_conn_state_res: case event_loop_conn_state_res:
conn_state_res(conn); conn_state_res(conn);
break; break;
case event_loop_conn_state_end:
printf("we shouldn't be here\n");
break;
} }
} }

View File

@ -3,6 +3,7 @@
#include <stdint.h> #include <stdint.h>
#include <stdlib.h> #include <stdlib.h>
#include <stdbool.h>
#include "event_loop.h" #include "event_loop.h"
@ -16,7 +17,11 @@ typedef struct event_loop_conn {
size_t wbuf_size; size_t wbuf_size;
size_t wbuf_sent; size_t wbuf_sent;
uint8_t wbuf[EVENT_LOOP_BUFFER_SIZE]; uint8_t wbuf[EVENT_LOOP_BUFFER_SIZE];
void (*process_func)(struct event_loop_conn *);
// If true, the server will close the connection after the final write buffer
// has been written
bool close_after_write;
/* void (*process_func)(struct event_loop_conn *); */
} event_loop_conn; } event_loop_conn;
/* /*