CでWebサーバーを作る

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <unistd.h>
#include <time.h>
#include <fcntl.h>

#define DOCUMENT_ROOT "."

#define BUF_SIZE 1024

int generate_date(char *time_str) {
   time_t timer;
   struct tm *gmt;
   char wday_name[][4] = {"Sun", "Mon", "Tue", "Wed", "Thr", "Fri", "Sat"},
           mon_name[][4] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};

   timer = time(NULL);
   gmt = gmtime(&timer);

   sprintf(
           time_str,
           "%s, %d %s %d %d:%d:%d GMT\r\n",
           wday_name[gmt->tm_wday],
           gmt->tm_mday,
           mon_name[gmt->tm_mon],
           gmt->tm_year + 1900,
           gmt->tm_hour,
           gmt->tm_min,
           gmt->tm_sec);

   return 0;
}

int handle_tcp_client(int serverSock, int clientSock) {
   int clientLen, i, filefd;
   struct sockaddr_in client;
   char request_buf[BUF_SIZE],
           response_header[BUF_SIZE],
           response_body[BUF_SIZE],

           request_http_method[BUF_SIZE],
           request_url[BUF_SIZE],
           request_protocol[BUF_SIZE],
           file_path[BUF_SIZE] = "",

           time_str[BUF_SIZE];

   // 接続を受け付ける
   clientLen = sizeof(client);
   clientSock = accept(serverSock, (struct sockaddr ＊) &client, (socklen_t＊ ) &clientLen);
   printf("Client Address: %s\n", inet_ntoa(client.sin_addr));
   if (clientSock < 0) {
       perror("Error: accept");
       return 1;
   }

   memset(request_buf, 0, sizeof(request_buf));

   // 接続情報をrequest_bufに格納
   recv(clientSock, request_buf, sizeof(request_buf), 0);

   sscanf(request_buf, "%s %s %s", request_http_method, request_url, request_protocol);

   sprintf(file_path, DOCUMENT_ROOT);
   strcat(file_path, request_url);

   if (file_path[strlen(file_path) - 1] == '/') {
       strcat(file_path, "index.html");
   }

   // 確認用
   printf("%s\n", "****************************");
   printf("Method: %s\n", request_http_method);
   printf("Request Url: %s\n", request_url);
   printf("Protocol: %s\n", request_protocol);
   printf("%s\n", "****************************");

   generate_date(time_str);

   // response_header 送信
   memset(response_header, 0, sizeof(response_header));

   i = snprintf(response_header, sizeof(response_header), "HTTP/1.1 200 OK\r\n");
   i += snprintf(response_header + i, sizeof(response_header), "Date: %s", time_str);
   i += snprintf(response_header + i, sizeof(response_header), "Server: Urache 0.0.1\r\n");
   i += snprintf(response_header + i, sizeof(response_header), "Accept-Ranges: bytes\r\n");
   i += snprintf(response_header + i, sizeof(response_header), "Content-Type: text/html; charset=UTF-8\r\n");
   i += snprintf(response_header + i, sizeof(response_header), "\r\n");

   if (send(clientSock, response_header, (int) strlen(response_header), 0) < 0) {
       perror("Error: Sending Header");
   }

   // response_body 送信
   memset(response_body, 0, sizeof(response_body));

   if ((filefd = open(file_path, O_RDONLY)) < 0) {
       perror("open");
       fprintf(stderr, "file: %s\n", file_path);
   } else {
       while ((read(filefd, response_body, sizeof(response_body))) > 0) {
           if (send(clientSock, response_body, (int) strlen(response_body), 0) < 0) {
               perror("Error: Sending Body");
           }
       }
   }

   // 接続を閉じる
   close(clientSock);

   return 0;
}


int main() {
   int serverSock, clientSock, v = 1;
   struct sockaddr_in addr;

   serverSock = socket(AF_INET, SOCK_STREAM, 0);
   if (serverSock < 0) {
       perror("Error: socket");
       return 1;
   }

   addr.sin_family = AF_INET;
   addr.sin_port = htons(9000);
   addr.sin_addr.s_addr = INADDR_ANY;

   setsockopt(serverSock,
              SOL_SOCKET, SO_REUSEADDR, (const char *) &v, sizeof(v));

if (bind(serverSock, (struct sockaddr *) &addr, sizeof(addr)) != 0) {
       perror("Error: bind");
       return 1;
   }

   // 接続を待機する
   if (listen(serverSock, 5) != 0) {
       perror("Error: listen");
       return 1;
   }

   for (;;) {
       // 接続に対して返信する
       if (handle_tcp_client(serverSock, clientSock) > 0) {
           break;
       }
   }

   close(serverSock);

   return 0;
}

src
├ content/index.html
├ index.html
└ urache ( 実行ファイル )