refactor: clean up the code to start development properly

c-web-server
Jef Roosens 2023-05-24 12:05:09 +02:00
parent 11cd537759
commit a163ee5155
Signed by: Jef Roosens
GPG Key ID: B75D4F293C7052DB
9 changed files with 461 additions and 344 deletions

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@ -6,18 +6,21 @@ BIN_FILENAME ?= lander
BUILD_DIR ?= build BUILD_DIR ?= build
SRC_DIR ?= src SRC_DIR ?= src
TEST_DIR ?= test TEST_DIR ?= test
INC_DIRS ?= include THIRDPARTY_DIR ?= thirdparty
INC_DIRS ?= include $(THIRDPARTY_DIR)/include
BIN := $(BUILD_DIR)/$(BIN_FILENAME) BIN := $(BUILD_DIR)/$(BIN_FILENAME)
SRCS != find '$(SRC_DIR)' -iname '*.c' SRCS != find '$(SRC_DIR)' -iname '*.c'
SRCS_H != find $(INC_DIRS) -iname '*.h'
SRCS_H_INTERNAL != find $(SRC_DIR) -iname '*.h'
SRCS_TEST != find '$(TEST_DIR)' -iname '*.c' SRCS_TEST != find '$(TEST_DIR)' -iname '*.c'
SRCS_THIRDPARTY != find '$(THIRDPARTY_DIR)/src' -iname '*.c'
OBJS := $(SRCS:%=$(BUILD_DIR)/%.o) SRCS_H != find include -iname '*.h'
SRCS_H_INTERNAL != find $(SRC_DIR) -iname '*.h'
OBJS := $(SRCS:%=$(BUILD_DIR)/%.o) $(SRCS_THIRDPARTY:%=$(BUILD_DIR)/%.o)
OBJS_TEST := $(SRCS_TEST:%=$(BUILD_DIR)/%.o) OBJS_TEST := $(SRCS_TEST:%=$(BUILD_DIR)/%.o)
DEPS := $(SRCS:%=$(BUILD_DIR)/%.d) $(SRCS_TEST:%=$(BUILD_DIR)/%.d) DEPS := $(SRCS:%=$(BUILD_DIR)/%.d) $(SRCS_THIRDPARTY:%=$(BUILD_DIR)/%.d) $(SRCS_TEST:%=$(BUILD_DIR)/%.d)
BINS_TEST := $(OBJS_TEST:%.c.o=%) BINS_TEST := $(OBJS_TEST:%.c.o=%)
TARGETS_TEST := $(BINS_TEST:%=test-%) TARGETS_TEST := $(BINS_TEST:%=test-%)
@ -51,6 +54,10 @@ $(BUILD_DIR)/$(SRC_DIR)/%.c.o: $(SRC_DIR)/%.c
mkdir -p $(dir $@) mkdir -p $(dir $@)
$(CC) $(INTERNALCFLAGS) -c $< -o $@ $(CC) $(INTERNALCFLAGS) -c $< -o $@
$(BUILD_DIR)/$(THIRDPARTY_DIR)/%.c.o: $(THIRDPARTY_DIR)/%.c
mkdir -p $(dir $@)
$(CC) $(INTERNALCFLAGS) -c $< -o $@
# =====TESTING===== # =====TESTING=====
.PHONY: test .PHONY: test

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@ -0,0 +1,33 @@
#ifndef LANDER_EVENT_LOOP
#define LANDER_EVENT_LOOP
// Size of the read and write buffers for each connection, in bytes
#define EVENT_LOOP_BUFFER_SIZE 1024
/**
* Represents an active connection managed by the event loop
*/
typedef struct event_loop_conn event_loop_conn;
typedef enum {
event_loop_conn_state_req = 0,
event_loop_conn_state_res = 1,
event_loop_conn_state_end = 2,
} event_loop_conn_state;
/*
* Main struct object representing the event loop
*/
typedef struct event_loop event_loop;
/*
* Initialize a new event loop
*/
event_loop *event_loop_init();
/*
* Run the event loop. This function never returns.
*/
void event_loop_run(event_loop *el, int port);
#endif

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@ -1,339 +0,0 @@
#include <stdint.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <stdio.h>
#include <poll.h>
#include <unistd.h>
#include <netinet/in.h>
#include <errno.h>
#include <stdbool.h>
#include <string.h>
#include "picohttpparser.h"
#define MAX_MSG_SIZE 1024
const char http_200_ok[] =
"HTTP/1.1 200 OK\n"
"Connection: close\n";
static void fd_set_nb(int fd) {
int flags = fcntl(fd, F_GETFL, 0);
/* if (errno) { */
/* die("fcntl error"); */
/* return; */
/* } */
flags |= O_NONBLOCK;
fcntl(fd, F_SETFL, flags);
/* if (errno) { */
/* die("fcntl error"); */
/* } */
}
enum {
STATE_REQ = 0,
STATE_RES = 1,
STATE_END = 2,
};
typedef struct conn {
int fd;
uint32_t state;
// buffer for reading
size_t rbuf_size;
uint8_t rbuf[MAX_MSG_SIZE];
// buffer for writing
size_t wbuf_size;
size_t wbuf_sent;
uint8_t wbuf[MAX_MSG_SIZE];
void (*process_func) (struct conn *);
} conn;
typedef struct event_loop {
conn **connections;
size_t connection_count;
} event_loop;
void event_loop_put(event_loop *loop, conn *c) {
// TODO properly catch realloc
if (c->fd >= loop->connection_count) {
loop->connections = realloc(loop->connections, sizeof(conn) * (c->fd + 1));
loop->connection_count = c->fd + 1;
}
printf("Add fd %i\n", c->fd);
loop->connections[c->fd] = c;
}
int event_loop_accept(event_loop *loop, int fd) {
struct sockaddr_in client_addr;
socklen_t socklen = sizeof(client_addr);
int connfd = accept(fd, (struct sockaddr *)&client_addr, &socklen);
if (connfd < 0) {
printf("accept() error");
return -1; // error
}
// set the new connection fd to nonblocking mode
fd_set_nb(connfd);
// creating the struct Conn
conn *c = calloc(sizeof(conn), 1);
if (!c) {
close(connfd);
return -1;
}
c->fd = connfd;
c->state = STATE_REQ;
event_loop_put(loop, c);
return 0;
}
bool conn_write_to_fd(conn *c) {
ssize_t res = 0;
size_t remain = c->wbuf_size - c->wbuf_sent;
do {
res = write(c->fd, &c->wbuf[c->wbuf_sent], remain);
} while (res < 0 && errno == EINTR);
// EAGAIN doesn't mean there was an error, but rather that there's no more
// data right now, but there might be more later, aka "try again later"
if (res < 0 && errno == EAGAIN) {
return false;
}
// If it's not EGAIN, there was an error writing so we simply end the request
if (res < 0) {
c->state = STATE_END;
return false;
}
c->wbuf_sent += (size_t)res;
// Everything is written from the buffer, so we exit
if (c->wbuf_sent == c->wbuf_size) {
c->state = STATE_END;
/* c->wbuf_sent = 0; */
/* c->wbuf_size = 0; */
return false;
}
// still got some data in wbuf, could try to write again
return true;
}
void try_one_request(conn *c) {
if (c->process_func != NULL) {
c->process_func(c);
}
char *method, *path;
struct phr_header headers[16];
size_t method_len, path_len, num_headers;
int minor_version;
num_headers = sizeof(headers) / sizeof(headers[0]);
int res = phr_parse_request((const char *) c->rbuf, c->rbuf_size, &method, &method_len, &path, &path_len, &minor_version, headers, &num_headers, 0);
if (res > 0) {
} else if (res == -1) {
c->state = STATE_END;
} else if (res == -2) {
// We don't do anything here
}
}
/**
* Read new data into the read buffer. This command performs at most one
* successful read syscall.
*
* Returns whether the function should be retried immediately or not.
*/
bool conn_read_from_fd(conn *c) {
ssize_t res;
size_t cap = MAX_MSG_SIZE - c->rbuf_size;
// Try to read at most cap bytes from the file descriptor
do {
res = read(c->fd, &c->rbuf[c->rbuf_size], cap);
} while (res < 0 && errno == EINTR);
// EGAIN means we try again later
if (res < 0 && errno == EAGAIN) {
return false;
}
// Any other negative error message means the read errored out
if (res < 0) {
c->state = STATE_END;
return false;
}
// An output of 0 zero means we've reached the end of the input
if (res == 0) {
}
// We switch to processing mode if we've reached the end of the data stream,
// or if the read buffer is filled
/* if (res == 0 || c->rbuf_size == MAX_MSG_SIZE) { */
/* c->state = STATE_PROCESS; */
/* return false; */
/* } */
c->rbuf_size += (size_t)res;
printf("rbuf size: %lu", c->rbuf_size);
/* assert(conn->rbuf_size <= sizeof(conn->rbuf)); */
// 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".
try_one_request(c);
// We can keep reading as long as we're in request mode
return c->state == STATE_REQ;
/* while (try_one_request(conn)) {} */
/* return (conn->state == STATE_REQ); */
}
void conn_state_res(conn *c) {
while (conn_write_to_fd(c)) {}
}
void conn_state_req(conn *c) {
while (conn_read_from_fd(c)) {}
}
/* void conn_state_process(conn *c) { */
/* printf("bruh"); */
/* memcpy(c->wbuf, c->rbuf, c->rbuf_size); */
/* c->wbuf_size = c->rbuf_size; */
/* c->state = STATE_WRITE; */
/* } */
static void connection_io(conn *c) {
c->rbuf[c->rbuf_size - 1] = '\0';
printf("%s\n", c->rbuf);
switch (c->state) {
case STATE_REQ:
conn_state_req(c); break;
case STATE_RES:
conn_state_res(c); break;
}
printf("%i\n", c->state);
}
int main() {
setvbuf(stdout, NULL, _IONBF, 0);
int fd = socket(AF_INET, SOCK_STREAM, 0);
if (fd < 0) {
return -1;
/* die("socket()"); */
}
int val = 1;
setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
// bind
struct sockaddr_in addr = {};
addr.sin_family = AF_INET;
addr.sin_port = ntohs(8000);
addr.sin_addr.s_addr = ntohl(0); // wildcard address 0.0.0.0
int rv = bind(fd, (const struct sockaddr *)&addr, sizeof(addr));
if (rv) {
/* die("bind()"); */
return -1;
}
// listen
rv = listen(fd, SOMAXCONN);
if (rv) {
/* die("listen()"); */
return -1;
}
// set the listen fd to nonblocking mode
fd_set_nb(fd);
event_loop *loop = calloc(sizeof(event_loop), 1);
loop->connections = calloc(sizeof(conn), 1);
loop->connection_count = 1;
struct pollfd *poll_args = calloc(sizeof(struct pollfd), 32);
size_t poll_args_count;
// for convenience, the listening fd is put in the first position
struct pollfd pfd = {fd, POLLIN, 0};
poll_args[0] = pfd;
conn *c;
int events;
while (1) {
poll_args_count = 1;
// connection fds
for (size_t i = 0; i < loop->connection_count; i++) {
c = loop->connections[i];
if (!c) {
continue;
}
events = (c->state == STATE_REQ) ? POLLIN : POLLOUT;
events |= POLLERR;
struct pollfd pfd = {c->fd, events, 0};
poll_args[poll_args_count] = pfd;
poll_args_count++;
// We do at most 32 connections at a time for now
if (poll_args_count == 32)
break;
}
// poll for active fds
// the timeout argument doesn't matter here
int rv = poll(poll_args, (nfds_t)poll_args_count, 1000);
if (rv < 0) {
/* die("poll"); */
return -1;
}
// process active connections
for (size_t i = 1; i < poll_args_count; ++i) {
if (poll_args[i].revents) {
conn *c = loop->connections[poll_args[i].fd];
connection_io(c);
if (c->state == STATE_END) {
// client closed normally, or something bad happened.
// destroy this connection
loop->connections[c->fd] = NULL;
close(c->fd);
free(c);
}
}
}
// try to accept a new connection if the listening fd is active
if (poll_args[0].revents) {
(void)event_loop_accept(loop, fd);
}
}
return 0;
}

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@ -0,0 +1,205 @@
#include <errno.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <poll.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
#include "event_loop_internal.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) {
int flags = fcntl(fd, F_GETFL, 0);
if (errno) {
return -1;
}
flags |= O_NONBLOCK;
fcntl(fd, F_SETFL, flags);
if (errno) {
return -1;
}
return 0;
}
event_loop *event_loop_init() {
event_loop *el = calloc(sizeof(event_loop), 1);
// No idea if this is a good starter value
el->connections = calloc(sizeof(event_loop_conn), 16);
el->connection_count = 16;
return el;
}
int event_loop_put(event_loop *el, event_loop_conn *conn) {
if ((size_t)conn->fd >= el->connection_count) {
event_loop_conn **resized =
realloc(el->connections, sizeof(event_loop_conn) * (conn->fd + 1));
if (resized == NULL) {
return -1;
}
el->connections = resized;
el->connection_count = conn->fd + 1;
}
el->connections[conn->fd] = conn;
return 0;
}
int event_loop_accept(event_loop *loop, int fd) {
struct sockaddr_in client_addr;
socklen_t socklen = sizeof(client_addr);
int connfd = accept(fd, (struct sockaddr *)&client_addr, &socklen);
if (connfd < 0) {
return -1;
}
// set the new connection fd to nonblocking mode
int res = event_loop_fd_set_nb(connfd);
if (res < 0) {
close(connfd);
return -2;
}
// creating the struct Conn
event_loop_conn *conn = calloc(sizeof(event_loop_conn), 1);
// Close the connectoin if we fail to allocate a connection struct
if (conn == NULL) {
close(connfd);
return -3;
}
conn->fd = connfd;
conn->state = event_loop_conn_state_req;
res = event_loop_put(loop, conn);
if (res != 0) {
close(connfd);
return -4;
}
return 0;
}
void event_loop_run(event_loop *el, int port) {
int fd = socket(AF_INET, SOCK_STREAM, 0);
if (fd < 0) {
return;
}
int val = 1;
setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
// bind
struct sockaddr_in addr = {.sin_family = AF_INET,
.sin_port = ntohs(port),
.sin_addr.s_addr = ntohl(0)};
int res = bind(fd, (const struct sockaddr *)&addr, sizeof(addr));
if (res) {
return;
}
res = listen(fd, SOMAXCONN);
if (res) {
return;
}
// The listening socket is always poll'ed in non-blocking mode as well
res = event_loop_fd_set_nb(fd);
if (res != 0) {
return;
}
// TODO don't hardcode the number 32
struct pollfd *poll_args = calloc(sizeof(struct pollfd), 32);
size_t poll_args_count;
// for convenience, the listening fd is put in the first position
struct pollfd pfd = {fd, POLLIN, 0};
poll_args[0] = pfd;
event_loop_conn *conn;
int events;
while (1) {
poll_args_count = 1;
// connection fds
for (size_t i = 0; i < el->connection_count; i++) {
conn = el->connections[i];
if (conn == NULL) {
continue;
}
events = (conn->state == event_loop_conn_state_req) ? POLLIN : POLLOUT;
events |= POLLERR;
struct pollfd pfd = {conn->fd, events, 0};
poll_args[poll_args_count] = pfd;
poll_args_count++;
// We do at most 32 connections at a time for now
if (poll_args_count == 32)
break;
}
// poll for active fds
// the timeout argument doesn't matter here
int rv = poll(poll_args, (nfds_t)poll_args_count, 1000);
if (rv < 0) {
return;
}
// process active connections
for (size_t i = 1; i < poll_args_count; ++i) {
if (poll_args[i].revents) {
conn = el->connections[poll_args[i].fd];
event_loop_conn_io(conn);
if (conn->state == event_loop_conn_state_end) {
// client closed normally, or something bad happened.
// destroy this connection
el->connections[conn->fd] = NULL;
close(conn->fd);
free(conn);
}
}
}
// try to accept a new connection if the listening fd is active
if (poll_args[0].revents) {
(void)event_loop_accept(el, fd);
}
}
}

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@ -0,0 +1,149 @@
#include <errno.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <poll.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
#include "picohttpparser.h"
#include "event_loop_internal.h"
bool event_loop_conn_write_to_fd(event_loop_conn *conn) {
ssize_t res = 0;
size_t remain = conn->wbuf_size - conn->wbuf_sent;
do {
res = write(conn->fd, &conn->wbuf[conn->wbuf_sent], remain);
} while (res < 0 && errno == EINTR);
// EAGAIN doesn't mean there was an error, but rather that there's no more
// data right now, but there might be more later, aka "try again later"
if (res < 0 && errno == EAGAIN) {
return false;
}
// If it's not EGAIN, there was an error writing so we simply end the request
if (res < 0) {
conn->state = event_loop_conn_state_end;
return false;
}
conn->wbuf_sent += (size_t)res;
// Everything is written from the buffer, so we exit
if (conn->wbuf_sent == conn->wbuf_size) {
conn->state = event_loop_conn_state_end;
/* c->wbuf_sent = 0; */
/* c->wbuf_size = 0; */
return false;
}
// still got some data in wbuf, could try to write again
return true;
}
void try_one_request(event_loop_conn *conn) {
if (conn->process_func != NULL) {
conn->process_func(conn);
}
char *method, *path;
struct phr_header headers[16];
size_t method_len, path_len, num_headers;
int minor_version;
num_headers = sizeof(headers) / sizeof(headers[0]);
int res = phr_parse_request((const char *)conn->rbuf, conn->rbuf_size,
&method, &method_len, &path, &path_len,
&minor_version, headers, &num_headers, 0);
if (res > 0) {
} else if (res == -1) {
conn->state = event_loop_conn_state_end;
} else if (res == -2) {
// We don't do anything here
}
}
/**
* Read new data into the read buffer. This command performs at most one
* successful read syscall.
*
* Returns whether the function should be retried immediately or not.
*/
bool event_loop_conn_read_from_fd(event_loop_conn *conn) {
ssize_t res;
size_t cap = EVENT_LOOP_BUFFER_SIZE - conn->rbuf_size;
// Try to read at most cap bytes from the file descriptor
do {
res = read(conn->fd, &conn->rbuf[conn->rbuf_size], cap);
} while (res < 0 && errno == EINTR);
// EGAIN means we try again later
if (res < 0 && errno == EAGAIN) {
return false;
}
// Any other negative error message means the read errored out
if (res < 0) {
conn->state = event_loop_conn_state_end;
return false;
}
// An output of 0 zero means we've reached the end of the input
if (res == 0) {
}
// We switch to processing mode if we've reached the end of the data stream,
// or if the read buffer is filled
/* if (res == 0 || c->rbuf_size == MAX_MSG_SIZE) { */
/* c->state = STATE_PROCESS; */
/* return false; */
/* } */
conn->rbuf_size += (size_t)res;
/* assert(conn->rbuf_size <= sizeof(conn->rbuf)); */
// 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".
try_one_request(conn);
// We can keep reading as long as we're in request mode
return conn->state == event_loop_conn_state_req;
/* while (try_one_request(conn)) {} */
/* return (conn->state == STATE_REQ); */
}
void conn_state_res(event_loop_conn *conn) {
while (event_loop_conn_write_to_fd(conn)) {
}
}
void conn_state_req(event_loop_conn *conn) {
while (event_loop_conn_read_from_fd(conn)) {
}
}
void event_loop_conn_io(event_loop_conn *conn) {
switch (conn->state) {
case event_loop_conn_state_req:
conn_state_req(conn);
break;
case event_loop_conn_state_res:
conn_state_res(conn);
break;
}
}

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@ -0,0 +1,51 @@
#ifndef LANDER_EVENT_LOOP_INTERNAL
#define LANDER_EVENT_LOOP_INTERNAL
#include <stdint.h>
#include <stdlib.h>
#include "event_loop.h"
typedef struct event_loop_conn {
int fd;
event_loop_conn_state state;
// buffer for reading
size_t rbuf_size;
uint8_t rbuf[EVENT_LOOP_BUFFER_SIZE];
// buffer for writing
size_t wbuf_size;
size_t wbuf_sent;
uint8_t wbuf[EVENT_LOOP_BUFFER_SIZE];
void (*process_func)(struct event_loop_conn *);
} event_loop_conn;
/*
* Initialize a new event_loop_conn struct
*/
event_loop_conn *event_loop_conn_init();
typedef struct event_loop {
event_loop_conn **connections;
size_t connection_count;
} event_loop;
/*
* Initialize a new event_loop struct
*/
event_loop *event_loop_init();
/*
* Place a new connection into the event loop's internal array.
*
* Returns -1 if the internal realloc failed
*/
int event_loop_put(event_loop *loop, event_loop_conn *conn);
/**
* Accept a new connection for the given file descriptor.
*/
int event_loop_accept(event_loop *loop, int fd);
void event_loop_conn_io(event_loop_conn *conn);
#endif

11
src/main.c 100644
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@ -0,0 +1,11 @@
#include <stdio.h>
#include "event_loop.h"
int main() {
setvbuf(stdout, NULL, _IONBF, 0);
event_loop *el = event_loop_init();
event_loop_run(el, 8000);
}