initial commit

yay start of a state machine and also learning sockets

9 files changed, 435 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..a426513
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,111 @@
+
+# Created by https://www.toptal.com/developers/gitignore/api/c,emacs
+# Edit at https://www.toptal.com/developers/gitignore?templates=c,emacs
+
+### C ###
+# Prerequisites
+*.d
+
+# Object files
+*.o
+*.ko
+*.obj
+*.elf
+
+# Linker output
+*.ilk
+*.map
+*.exp
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Libraries
+*.lib
+*.a
+*.la
+*.lo
+
+# Shared objects (inc. Windows DLLs)
+*.dll
+*.so
+*.so.*
+*.dylib
+
+# Executables
+*.exe
+*.out
+*.app
+*.i*86
+*.x86_64
+*.hex
+
+# Debug files
+*.dSYM/
+*.su
+*.idb
+*.pdb
+
+# Kernel Module Compile Results
+*.mod*
+*.cmd
+.tmp_versions/
+modules.order
+Module.symvers
+Mkfile.old
+dkms.conf
+
+### Emacs ###
+# -*- mode: gitignore; -*-
+*~
+\#*\#
+/.emacs.desktop
+/.emacs.desktop.lock
+*.elc
+auto-save-list
+tramp
+.\#*
+
+# Org-mode
+.org-id-locations
+*_archive
+
+# flymake-mode
+*_flymake.*
+
+# eshell files
+/eshell/history
+/eshell/lastdir
+
+# elpa packages
+/elpa/
+
+# reftex files
+*.rel
+
+# AUCTeX auto folder
+/auto/
+
+# cask packages
+.cask/
+dist/
+
+# Flycheck
+flycheck_*.el
+
+# server auth directory
+/server/
+
+# projectiles files
+.projectile
+
+# directory configuration
+.dir-locals.el
+
+# network security
+/network-security.data
+
+
+# End of https://www.toptal.com/developers/gitignore/api/c,emacs
+cmud*
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..1b79565
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,22 @@
+CC=gcc
+CFLAGS=-I. -static
+SRCS=src/main.c src/login.c src/server.c src/data.c
+BIN=cmud
+
+%.o: %.c
+	$(CC) -c -o $@ $< $(CFLAGS)
+
+dev: $(SRCS)
+	$(CC) -o $(BIN)-devel $(SRCS) $(LFLAGS) -g
+
+main: $(SRCS)
+	$(CC) -o $(BIN) $(SRCS) $(LFLAGS) $(CFLAGS)
+
+dist: main
+	tar czvf $(BIN).tar.gz $(BIN)
+
+clean:
+	rm $(BIN)*
+
+run: dev
+	./cmud-devel
diff --git a/src/data.c b/src/data.c
new file mode 100644
index 0000000..15617e0
--- /dev/null
+++ b/src/data.c
@@ -0,0 +1,60 @@
+#include <asm-generic/errno-base.h>
+#define _GNU_SOURCE
+#include "data.h"
+#include "login.h"
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+
+int try_make_data_dirs() {
+  int err = 0;
+  err = mkdir("data", S_IRWXU);
+  err = mkdir("data/players", S_IRWXU);
+
+  return err;
+}
+
+int try_load_plr(char *player_name, playerc_t *plr) {
+  int err = 0;
+  err = try_make_data_dirs();
+  if (err) {
+    switch (err) {
+        // Now the errors that continue will be from I/O, which we can use to figure out if the file exists in login
+    case EACCES: /* No permissions***************************************/
+        printf("No permissions to create directories\n");
+        return -1;
+        default:/* Do nothing because this is fine****************************/
+            break;
+    }
+  }
+
+  char *fname;
+  asprintf(&fname, "data/players/%s.plr", player_name);
+
+  FILE *fp = fopen(fname, "rb");
+
+  fread(&plr, sizeof(playerc_t), 1, fp);
+
+  return err;
+}
+
+int try_write_file(player_t *plr) {
+  int err = 0;
+
+  err = try_make_data_dirs();
+  if (err) {
+    perror("creating data directories");
+    printf("Could not create data/\n");
+    return err;
+  }
+
+  char *fname;
+  asprintf(&fname, "data/players/%s.plr", *plr->name);
+
+  FILE *fp = fopen(fname, "wb");
+
+  fwrite(&plr, sizeof(player_t), 1, fp);
+
+  return err;
+}
diff --git a/src/data.h b/src/data.h
new file mode 100644
index 0000000..a030d50
--- /dev/null
+++ b/src/data.h
@@ -0,0 +1,9 @@
+#ifndef DATA_H
+#define DATA_H
+
+#include "login.h"
+int try_load_file(char *player_name);
+
+int try_write_file(player_t *plr);
+
+#endif
diff --git a/src/login.c b/src/login.c
new file mode 100644
index 0000000..c6ab408
--- /dev/null
+++ b/src/login.c
@@ -0,0 +1,68 @@
+#include <string.h>
+#define _GNU_SOURCE
+#include "data.h"
+#include "login.h"
+#include "server.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+void handle_player(int conn_fd) {
+  playerc_t plrc = {0};
+  plrc.state = LoggedOut;
+  plrc.conn = conn_fd;
+  player_t plr = {0};
+  plrc.plr = plr;
+
+  int err = step_login(&plrc, conn_fd);
+  if (err) {
+    err = send_to_fd(conn_fd, "Error in login process, exiting");
+    if (err) {
+      printf("Could not send error message");
+    }
+    close(conn_fd);
+    return;
+  }
+
+  close(conn_fd);
+}
+
+int step_login(playerc_t *player, int conn_fd) {
+  int err = 0;
+
+  for (;;) {
+    switch (player->state) {
+    case LoggedOut: /* the player has yet to log in, this is a fresh connection!
+                     */
+      send_to_fd(player->conn,
+                 "Welcome! Please enter your **username** below\n");
+      char *buf = (char *)malloc(1 << 10);
+      recv(player->conn, buf, sizeof(buf), 0);
+      err = try_load_file(buf);
+      if (err) {
+        // File doesn't exist, let's create a player!
+        strcpy(player->plr.name, buf);
+        send_to_fd(player->conn, "Howdy! Want to introduce yourself? [y|n]\n");
+        recv(player->conn, buf, sizeof(buf), 0);
+        if (buf[0] == 'y') {
+          player->state = WantMakeAccount;
+        } else if (buf[0] == 'n') {
+          send_to_fd(player->conn,
+                     "Awww :(. Oh well, hope to see you again soon!\n");
+          return 4;
+        }
+        continue;
+      } else {
+        player->state = EnterPassword;
+        continue;
+      }
+    case WantMakeAccount:
+      asprintf(&buf,
+               "Welcome aboard %s! Why don't you start us off by giving me a "
+               "password.\n", ) send_to_fd(player->conn, "Welcome aboard! ")
+    }
+  }
+
+  return err;
+}
diff --git a/src/login.h b/src/login.h
new file mode 100644
index 0000000..6d4cc3d
--- /dev/null
+++ b/src/login.h
@@ -0,0 +1,32 @@
+#ifndef LOGIN_H
+#define LOGIN_H
+enum login_state {
+  LoggedOut,
+  EnterPassword,
+  WantMakeAccount,
+  MakePassword,
+  MakeConfirmPassword,
+  Complete
+};
+
+typedef struct player {
+  int xp;
+  int hp;
+  int max_hp;
+  int level;
+  int location_id;
+
+  char *name[];
+} player_t;
+
+typedef struct player_conn {
+  int conn;
+  enum login_state state;
+  struct player plr;
+} playerc_t;
+
+int step_login(playerc_t *player, int conn_fd);
+
+void handle_player(int conn_fd);
+
+#endif
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..4f848ba
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,32 @@
+/**
+ * Creates a socket for the server
+ * */
+#include "server.h"
+#include <stdio.h>
+
+/**
+ * Server entrypoint
+ *
+ * sets up everything needed to handle sockets and connections
+ * */
+int main() {
+  int err = 0;
+  server_t server = {0};
+
+  err = server_listen(&server);
+
+  if (err) {
+    printf("Failed to listen on address");
+    return err;
+  }
+
+  for (;;) {
+    err = server_accept(&server);
+    if (err) {
+      printf("Failed accepting connection");
+      return err;
+    }
+  }
+
+  return 0;
+}
diff --git a/src/server.c b/src/server.c
new file mode 100644
index 0000000..bee6153
--- /dev/null
+++ b/src/server.c
@@ -0,0 +1,84 @@
+#include "server.h"
+#include "login.h"
+#include <netinet/in.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+int server_listen(server_t *server) {
+  /*
+  **
+  ** The `socket(2)` syscall returns a file descriptor for a socket
+  **
+  ** it takes two arguments that we care about:
+  ** - domain -- AF_INET for IPv4
+  ** - type -- SOCK_STREAM sequenced and reliable
+  **
+  */
+  int err = (server->listen_fd = socket(AF_INET, SOCK_STREAM, 0));
+
+  if (err == -1) {
+    perror("socket");
+    printf("Failed to create socket");
+    return err;
+  }
+
+  struct sockaddr_in server_addr = {0};
+
+  server_addr.sin_family = AF_INET;
+  server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
+  server_addr.sin_port = htons(8000);
+
+  err = bind(server->listen_fd, (struct sockaddr *)&server_addr,
+             sizeof(server_addr));
+  if (err == -1) {
+    perror("bind");
+    printf("Failed to bind socket\n");
+    return err;
+  }
+
+  err = listen(server->listen_fd, 100);
+  if (err == -1) {
+    perror("listen");
+    printf("Failed to listen on socket\n");
+    return err;
+  }
+
+  return 0;
+}
+
+int server_accept(server_t *server) {
+  int err = 0;
+  int conn_fd;
+  socklen_t client_len;
+
+  struct sockaddr_in client_addr;
+
+  client_len = sizeof(client_addr);
+
+  for (;;) {
+    err = (conn_fd = accept(server->listen_fd, (struct sockaddr *)&client_addr,
+                            &client_len));
+    if (err == -1) {
+      perror("Accept");
+      printf("failed accepting connection\n");
+      return err;
+    }
+
+    if (!fork()) {
+      handle_player(conn_fd);
+    }
+  }
+
+  return err;
+}
+
+int send_to_fd(int fd, char *msg) {
+  int err = 0;
+
+  err = send(fd, msg, strlen(msg), 0);
+
+  return err;
+}
diff --git a/src/server.h b/src/server.h
new file mode 100644
index 0000000..5392f56
--- /dev/null
+++ b/src/server.h
@@ -0,0 +1,17 @@
+#ifndef SERVER_H_
+#define SERVER_H_
+
+/**
+ * Yay for storing the server properties
+ * */
+typedef struct server {
+  int listen_fd;
+} server_t;
+
+int server_listen(server_t *server);
+
+int server_accept(server_t *server);
+
+int send_to_fd(int fd, char *msg);
+
+#endif // SERVER_H_