2.6 请求处理层编写
得到请求后开始编写处理层。继续接着代码往下写没有层级,编写一个函数名为 req,该函数接收请求信息与一个建立好的连接为参数:
void req(char* buf, int access_socket)
{
}
然后先在 while 循环中传递需要的值:
req(buf, access_skt);
接着开始编写 req 函数,首先在 req 函数中标记当前目录下:
char arguments[BUFSIZ];
strcpy(arguments, "./");
随后分离出请求与参数:
char command[BUFSIZ];
sscanf(request, "%s%s", command, arguments+2);
接着我们标记一些头元素:
char* extension = "text/html";
char* content_type = "text/plain";
char* body_length = "Content-Length: ";
接着获取请求参数,若获取 index.html,就获取当前路径下的该文件:
FILE* rfile= fopen(arguments, "rb");
获取文件后表示请求 ok,我们先返回一个 200 状态:
char* head = "HTTP/1.1 200 OK\r\n";
int len;
char ctype[30] = "Content-type:text/html\r\n";
len = strlen(head);
接着编写一个发送函数 send_:
int send_(int s, char *buf, int *len)
{
int total;
int bytesleft;
int n;
total=0;
bytesleft=*len;
while(total < *len)
{
n = send(s, buf+total, bytesleft, 0);
if (n == -1)
{
break;
}
total += n;
bytesleft -= n;
}
*len = total;
return n==-1?-1:0;
}
send 函数功能并不难在此不再赘述,就是一个遍历发送的逻辑。随后发送 http 响应与文件类型:
send_(send_to, head, &len);
len = strlen(ctype);
send_(send_to, ctype, &len);
随后获得请求文件的描述,需要添加头文件#include <sys/stat.h>使用fstat,且向已连接的通信发生必要的信息 :
//获取文件描述
struct stat statbuf;
char read_buf[1024];
char length_buf[20];
fstat(fileno(rfile), &statbuf);
itoa( statbuf.st_size, length_buf, 10 );
send(client_sock, body_length, strlen(body_length), 0);
send(client_sock, length_buf, strlen(length_buf), 0);
send(client_sock, "\n", 1, 0);
send(client_sock, "\r\n", 2, 0);
最后发送数据:
//·数据发送
char read_buf[1024];
len = fread(read_buf ,1 , statbuf.st_size, rfile);
if (send_(client_sock, read_buf, &len) == -1) {
printf("error!");
}
最后访问地址
http://127.0.0.1:8080/index.html,得到当前目录下 index.html 文件数据,并且在浏览器渲染:
所有代码如下:
#include <WinSock2.h>
#include<stdio.h>
#include <sys/stat.h>
int send_(int s, char *buf, int *len) {
int total;
int bytesleft;
int n;
total=0;
bytesleft=*len;
while(total < *len)
{
n = send(s, buf+total, bytesleft, 0);
if (n == -1)
{
break;
}
total += n;
bytesleft -= n;
}
*len = total;
return n==-1?-1:0;
}
void req(char* request, int client_sock) {
char arguments[BUFSIZ];
strcpy(arguments, "./");
char command[BUFSIZ];
sscanf(request, "%s%s", command, arguments+2);
char* extension = "text/html";
char* content_type = "text/plain";
char* body_length = "Content-Length: ";
FILE* rfile= fopen(arguments, "rb");
char* head = "HTTP/1.1 200 OK\r\n";
int len;
char ctype[30] = "Content-type:text/html\r\n";
len = strlen(head);
send_(client_sock, head, &len);
len = strlen(ctype);
send_(client_sock, ctype, &len);
struct stat statbuf;
char length_buf[20];
fstat(fileno(rfile), &statbuf);
itoa( statbuf.st_size, length_buf, 10 );
send(client_sock, body_length, strlen(body_length), 0);
send(client_sock, length_buf, strlen(length_buf), 0);
send(client_sock, "\n", 1, 0);
send(client_sock, "\r\n", 2, 0);
char read_buf[1024];
len = fread(read_buf ,1 , statbuf.st_size, rfile);
if (send_(client_sock, read_buf, &len) == -1) {
printf("error!");
}
return;
}
int main(){
WSADATA wsaData;
if (WSAStartup(MAKEWORD(1, 1), &wsaData) != 0) {
exit(1);
}
int skt = socket(PF_INET, SOCK_STREAM, 0);
if (skt == -1) {
return -1;
}
struct sockaddr_in server_addr;
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(8080);
server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
memset(&(server_addr.sin_zero), '\0', 8);
if (bind(skt, (struct sockaddr *)&server_addr,sizeof(server_addr)) == -1) {
return -1;
}
if (listen(skt, 10) == -1 ) {
return -1;
}
while(1){
printf("Listening ... ...\n");
struct sockaddr_in c_skt;
int s_size=sizeof(struct sockaddr_in);
int access_skt = accept(skt, (struct sockaddr *)&c_skt, &s_size);
char buf[1024];
if (recv(access_skt, buf, 1024, 0) == -1) {
exit(1);
}
req(buf, access_skt);
}
}