Bozza iniziale del server

gamedata.c

@@ -0,0 +1,77 @@
+#include <stdio.h>
+#include "gamedata.h"
+
+struct _gamedata {
+  double chf;
+  int bitto;
+  int flour;
+  int pizzoccheri;
+  double chf_unit;
+};
+
+gamedata_t* gamedata_new() {
+  gamedata_t* self = (gamedata_t*) malloc(sizeof(gamedata_t));
+  if(errno != 0) {
+    perror("gamedata malloc() creation error: ");
+  }
+
+  self->chf = 0;
+  self->bitto = 500;
+  self->flour = 200;
+  self->pizzoccheri = 0;
+  self->chf_unit = 0.5;
+  return self;
+}
+
+void gamedata_delete(gamedata_t* self) {
+  free(self);
+}
+
+void gamedata_print_status(gamedata_t *self, FILE* out) {
+  fprintf(out, "OK BITTO %d, FLOUR %d, ", self->bitto, self->flour);
+  fprintf(out, "INVENTORY %d, ", self->pizzoccheri);
+  fprintf(out, "UNIT PRICE %.02f CHF, PROFIT %.02f CHF\n", self->chf_unit, self->chf);
+}
+
+#define Q_BITTO_FOR_PIZZOCCHERO 1
+#define Q_FLOUR_FOR_PIZZOCCHERO 2
+bool gamedata_make_pizzoccheri(gamedata_t *self, unsigned int q) {
+  int q_flour = q * Q_FLOUR_FOR_PIZZOCCHERO;
+  int q_bitto = q * Q_BITTO_FOR_PIZZOCCHERO;
+
+  if(self->flour < q_flour || self->bitto < q_bitto) {
+    return false;
+  }
+
+  self->flour -= q_flour;
+  self->bitto -= q_bitto;
+  self->pizzoccheri += q;
+
+  return true;
+}
+
+#define PRICE_BITTO_UNIT 0.5
+bool gamedata_buy_bitto(gamedata_t *self, unsigned int q) {
+  double price = q * PRICE_BITTO_UNIT;
+
+  if(price > self->chf) {
+    return false;
+  }
+
+  self->chf -= price;
+  self->bitto += q;
+  return true;
+}
+
+#define PRICE_FLOUR_UNIT 0.5
+bool gamedata_buy_flour(gamedata_t *self, unsigned int q) {
+  double price = q * PRICE_FLOUR_UNIT;
+
+  if(price > self->chf) {
+    return false;
+  }
+
+  self->chf -= price;
+  self->flour += q;
+  return true;
+}

gamedata.h

@@ -0,0 +1,17 @@
+#ifndef gamedata
+#define gamedata
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <errno.h>
+
+typedef struct _gamedata gamedata_t;
+
+extern gamedata_t* gamedata_new();
+extern void gamedata_delete();
+extern bool gamedata_buy_bitto(gamedata_t*, unsigned int);
+extern bool gamedata_buy_flour(gamedata_t*, unsigned int);
+extern void gamedata_print_status(gamedata_t*, FILE*);
+extern bool gamedata_make_pizzoccheri(gamedata_t*, unsigned int);
+
+#endif

server.c

@@ -0,0 +1,129 @@
+#include <arpa/inet.h>
+#include <sys/types.h>
+#include <stdint.h>
+#include <sys/socket.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include "gamedata.h"
+
+#define SERVER_ADDR htonl(INADDR_ANY)
+#define MAX_CLIENTS 100
+#define MAX_COMMAND_LINE_LENGTH 101
+
+bool prefix(const char *pre, const char *str) {
+  return strncmp(pre, str, strlen(pre)) == 0;
+}
+
+int main(int argc, char** argv) {
+
+  if(argc < 2) {
+    fprintf(stderr, "Give port number as $1\n");
+    exit(255);
+  }
+
+  int sock_conn_d, sock_data_d;
+  struct sockaddr_in server;
+
+  if((sock_conn_d = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
+    perror("server socket not created");
+    exit(1);
+  }
+
+  memset(&server, 0, sizeof(server)); // zero the memory
+
+  server.sin_family = AF_INET;
+  server.sin_addr.s_addr = SERVER_ADDR;
+  server.sin_port = htons(atoi(argv[1]));
+
+  if(bind(sock_conn_d, (struct sockaddr*)&server, sizeof(server)) == -1) {
+    perror("server socket not bound");
+    exit(2);
+  }
+
+  while(true) {
+    if(listen(sock_conn_d, MAX_CLIENTS) != 0) {
+      perror("cannot listen on socket");
+      close(sock_conn_d);
+      exit(3);
+    }
+
+    printf("listening...\n");
+
+    struct sockaddr_in client;
+    socklen_t client_len = sizeof(client);
+    sock_data_d = accept(sock_conn_d, (struct sockaddr*)&client, &client_len);
+
+    if(sock_data_d == -1) {
+      perror("cannot accept client");
+      close(sock_conn_d);
+      exit(4);
+    }
+
+    pid_t pid = fork();
+
+    if(pid < 0) {
+      perror("cannot fork for new client");
+      exit(6);
+    }
+    else if(pid == 0) {
+      gamedata_t *curr_data = gamedata_new();
+
+      unsigned char command[MAX_COMMAND_LINE_LENGTH];
+      FILE* in = fdopen(sock_data_d, "r");
+      FILE* out = fdopen(dup(sock_data_d), "w");
+
+      fprintf(out, "OK Connection establshed.\n");
+      fflush(out);
+
+      while(true) {
+        fgets(command, MAX_COMMAND_LINE_LENGTH, in);
+
+        union {
+          unsigned int u;
+          double d;
+        } arg1;
+
+        if(sscanf(command, "MAKE %u\n", &(arg1.u)) == 1) {
+          bool status = gamedata_make_pizzoccheri(curr_data, arg1.u);
+          fprintf(out, status ? "OK Made.\n" : "KO 1 Insufficient resources.\n");
+        }
+        else if(sscanf(command, "BUY BITTO %u", &(arg1.u)) == 1) {
+          bool status = gamedata_buy_bitto(curr_data, arg1.u);
+          fprintf(out, status ? "OK Purchased.\n" : "KO 2 Insufficient funds\n");
+        }
+        else if(sscanf(command, "BUY FLOUR %u", &(arg1.u)) == 1) {
+          bool status = gamedata_buy_flour(curr_data, arg1.u);
+          fprintf(out, status ? "OK Purchased.\n" : "KO 3 Insufficient funds\n");
+        }
+        else if(prefix("STATUS", command)) {
+          gamedata_print_status(curr_data, out);
+        }
+        else if(prefix("EXIT", command)) {
+          fprintf(out, "OK Closing...\n");
+          break;
+        }
+        else {
+          fprintf(out, "KO 255 Syntax error\n");
+        }
+
+        fflush(out);
+      }
+
+      printf("closing data socket...\n");
+
+      fclose(in);
+      fclose(out);
+
+      gamedata_delete(curr_data);
+
+      printf("exiting...\n");
+      exit(0);
+    }
+    // if father process just continue
+  }
+  close(sock_conn_d);
+  exit(0);
+}